Cells derived from the BLASTOCYST INNER CELL MASS which forms before implantation in the uterine wall. They retain the ability to divide, proliferate and provide progenitor cells that can differentiate into specialized cells.
Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Cells that can give rise to cells of the three different GERM LAYERS.
The transfer of STEM CELLS from one individual to another within the same species (TRANSPLANTATION, HOMOLOGOUS) or between species (XENOTRANSPLANTATION), or transfer within the same individual (TRANSPLANTATION, AUTOLOGOUS). The source and location of the stem cells determines their potency or pluripotency to differentiate into various cell types.
The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.
An octamer transcription factor that is expressed primarily in totipotent embryonic STEM CELLS and GERM CELLS and is down-regulated during CELL DIFFERENTIATION.
Progenitor cells from which all blood cells derive.
Cells from adult organisms that have been reprogrammed into a pluripotential state similar to that of EMBRYONIC STEM CELLS.
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
Methods for maintaining or growing CELLS in vitro.
Cells with high proliferative and self renewal capacities derived from adults.
Spontaneous aggregations of human embryonic stem cells that occur in vitro after culturing in a medium that lacks LEUKEMIC INHIBITORY FACTOR. The embryoid bodies can further differentiate into cells that represent different lineages.
Self-renewing cells that generate the main phenotypes of the nervous system in both the embryo and adult. Neural stem cells are precursors to both NEURONS and NEUROGLIA.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Established cell cultures that have the potential to propagate indefinitely.
Experimentation on, or using the organs or tissues from, a human or other mammalian conceptus during the prenatal stage of development that is characterized by rapid morphological changes and the differentiation of basic structures. In humans, this includes the period from the time of fertilization to the end of the eighth week after fertilization.
A subclass of SOX transcription factors that are expressed in neuronal tissue where they may play a role in the regulation of CELL DIFFERENTIATION. Members of this subclass are generally considered to be transcriptional activators.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
A true neoplasm composed of a number of different types of tissue, none of which is native to the area in which it occurs. It is composed of tissues that are derived from three germinal layers, the endoderm, mesoderm, and ectoderm. They are classified histologically as mature (benign) or immature (malignant). (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1642)
Specialized stem cells that are committed to give rise to cells that have a particular function; examples are MYOBLASTS; MYELOID PROGENITOR CELLS; and skin stem cells. (Stem Cells: A Primer [Internet]. Bethesda (MD): National Institutes of Health (US); 2000 May [cited 2002 Apr 5]. Available from: http://www.nih.gov/news/stemcell/primer.htm)
A particular zone of tissue composed of a specialized microenvironment where stem cells are retained in a undifferentiated, self-renewable state.
Transfer of HEMATOPOIETIC STEM CELLS from BONE MARROW or BLOOD between individuals within the same species (TRANSPLANTATION, HOMOLOGOUS) or transfer within the same individual (TRANSPLANTATION, AUTOLOGOUS). Hematopoietic stem cell transplantation has been used as an alternative to BONE MARROW TRANSPLANTATION in the treatment of a variety of neoplasms.
Single cells that have the potential to form an entire organism. They have the capacity to specialize into extraembryonic membranes and tissues, the embryo, and all postembryonic tissues and organs. (Stem Cells: A Primer [Internet]. Bethesda (MD): National Institutes of Health (US); 2000 May [cited 2002 Apr 5]. Available from: http://www.nih.gov/news/stemcell/primer.htm)
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
The three primary germinal layers (ECTODERM; ENDODERM; and MESODERM) developed during GASTRULATION that provide tissues and body plan of a mature organism. They derive from two early layers, hypoblast and epiblast.
Bone-marrow-derived, non-hematopoietic cells that support HEMATOPOETIC STEM CELLS. They have also been isolated from other organs and tissues such as UMBILICAL CORD BLOOD, umbilical vein subendothelium, and WHARTON JELLY. These cells are considered to be a source of multipotent stem cells because they include subpopulations of mesenchymal stem cells.
Transfer of MESENCHYMAL STEM CELLS between individuals within the same species (TRANSPLANTATION, HOMOLOGOUS) or transfer within the same individual (TRANSPLANTATION, AUTOLOGOUS).
The inner of the three germ layers of an embryo.
An INTERLEUKIN-6 related cytokine that exhibits pleiotrophic effects on many physiological systems that involve cell proliferation, differentiation, and survival. Leukemia inhibitory factor binds to and acts through the lif receptor.
Experimentation on STEM CELLS and on the use of stem cells.
An individual that contains cell populations derived from different zygotes.
The integration of exogenous DNA into the genome of an organism at sites where its expression can be suitably controlled. This integration occurs as a result of homologous recombination.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
A hematopoietic growth factor and the ligand of the cell surface c-kit protein (PROTO-ONCOGENE PROTEINS C-KIT). It is expressed during embryogenesis and is a growth factor for a number of cell types including the MAST CELLS and the MELANOCYTES in addition to the HEMATOPOIETIC STEM CELLS.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.
Cell-surface molecules that exhibit lineage-restricted patterns of expression during EMBRYONIC DEVELOPMENT. The antigens are useful markers in the identification of EMBRYONIC STEM CELLS.
The process that reverts CELL NUCLEI of fully differentiated somatic cells to a pluripotent or totipotent state. This process can be achieved to a certain extent by NUCLEAR TRANSFER TECHNIQUES, such as fusing somatic cell nuclei with enucleated pluripotent embryonic stem cells or enucleated totipotent oocytes. GENE EXPRESSION PROFILING of the fused hybrid cells is used to determine the degree of reprogramming. Dramatic results of nuclear reprogramming include the generation of cloned mammals, such as Dolly the sheep in 1997.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Cells used in COCULTURE TECHNIQUES which support the growth of the other cells in the culture. Feeder cells provide auxillary substances including attachment substrates, nutrients, or other factors that are needed for growth in culture.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A field of medicine concerned with developing and using strategies aimed at repair or replacement of damaged, diseased, or metabolically deficient organs, tissues, and cells via TISSUE ENGINEERING; CELL TRANSPLANTATION; and ARTIFICIAL ORGANS and BIOARTIFICIAL ORGANS and tissues.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
A bone morphogenetic protein that is a potent inducer of bone formation. It also functions as a regulator of MESODERM formation during EMBRYONIC DEVELOPMENT.
Cell separation is the process of isolating and distinguishing specific cell types or individual cells from a heterogeneous mixture, often through the use of physical or biological techniques.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.
The development and formation of various types of BLOOD CELLS. Hematopoiesis can take place in the BONE MARROW (medullary) or outside the bone marrow (HEMATOPOIESIS, EXTRAMEDULLARY).
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Cells derived from a FETUS that retain the ability to divide, proliferate and provide progenitor cells that can differentiate into specialized cells.
A genetic process by which the adult organism is realized via mechanisms that lead to the restriction in the possible fates of cells, eventually leading to their differentiated state. Mechanisms involved cause heritable changes to cells without changes to DNA sequence such as DNA METHYLATION; HISTONE modification; DNA REPLICATION TIMING; NUCLEOSOME positioning; and heterochromatization which result in selective gene expression or repression.
Morphological and physiological development of EMBRYOS.
Mice homozygous for the mutant autosomal recessive gene "scid" which is located on the centromeric end of chromosome 16. These mice lack mature, functional lymphocytes and are thus highly susceptible to lethal opportunistic infections if not chronically treated with antibiotics. The lack of B- and T-cell immunity resembles severe combined immunodeficiency (SCID) syndrome in human infants. SCID mice are useful as animal models since they are receptive to implantation of a human immune system producing SCID-human (SCID-hu) hematochimeric mice.
The physiological renewal, repair, or replacement of tissue.
Activins are produced in the pituitary, gonads, and other tissues. By acting locally, they stimulate pituitary FSH secretion and have diverse effects on cell differentiation and embryonic development. Activins are glycoproteins that are hetero- or homodimers of INHIBIN-BETA SUBUNITS.
A reverse developmental process in which terminally differentiated cells with specialized functions revert back to a less differentiated stage within their own CELL LINEAGE.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Highly proliferative, self-renewing, and colony-forming stem cells which give rise to NEOPLASMS.
The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.
Mapping of the KARYOTYPE of a cell.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
The formation of one or more genetically identical organisms derived by vegetative reproduction from a single cell. The source nuclear material can be embryo-derived, fetus-derived, or taken from an adult somatic cell.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.
An important regulator of GENE EXPRESSION during growth and development, and in NEOPLASMS. Tretinoin, also known as retinoic acid and derived from maternal VITAMIN A, is essential for normal GROWTH; and EMBRYONIC DEVELOPMENT. An excess of tretinoin can be teratogenic. It is used in the treatment of PSORIASIS; ACNE VULGARIS; and several other SKIN DISEASES. It has also been approved for use in promyelocytic leukemia (LEUKEMIA, PROMYELOCYTIC, ACUTE).
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
Therapies that involve the TRANSPLANTATION of CELLS or TISSUES developed for the purpose of restoring the function of diseased or dysfunctional cells or tissues.
The malignant stem cells of TERATOCARCINOMAS, which resemble pluripotent stem cells of the BLASTOCYST INNER CELL MASS. The EC cells can be grown in vitro, and experimentally induced to differentiate. They are used as a model system for studying early embryonic cell differentiation.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.
Cells contained in the bone marrow including fat cells (see ADIPOCYTES); STROMAL CELLS; MEGAKARYOCYTES; and the immediate precursors of most blood cells.
A genus of the family RETROVIRIDAE consisting of non-oncogenic retroviruses that produce multi-organ diseases characterized by long incubation periods and persistent infection. Lentiviruses are unique in that they contain open reading frames (ORFs) between the pol and env genes and in the 3' env region. Five serogroups are recognized, reflecting the mammalian hosts with which they are associated. HIV-1 is the type species.
Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.
A family of sequence-related proteins similar to HMGB1 PROTEIN that contains specific HMG-BOX DOMAINS.
A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.
A type VI intermediate filament protein expressed mostly in nerve cells where it is associated with the survival, renewal and mitogen-stimulated proliferation of neural progenitor cells.
A subclass of closely-related SOX transcription factors. Members of this subclass are expressed in VASCULAR ENDOTHELIAL CELLS and may play a role in vasculogenesis.
Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.
Formation of NEURONS which involves the differentiation and division of STEM CELLS in which one or both of the daughter cells become neurons.
The region in the dorsal ECTODERM of a chordate embryo that gives rise to the future CENTRAL NERVOUS SYSTEM. Tissue in the neural plate is called the neuroectoderm, often used as a synonym of neural plate.
The release of stem cells from the bone marrow into the peripheral blood circulation for the purpose of leukapheresis, prior to stem cell transplantation. Hematopoietic growth factors or chemotherapeutic agents often are used to stimulate the mobilization.
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.
CULTURE MEDIA free of serum proteins but including the minimal essential substances required for cell growth. This type of medium avoids the presence of extraneous substances that may affect cell proliferation or unwanted activation of cells.
Elements of limited time intervals, contributing to particular results or situations.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The cluster of cells inside a blastocyst. These cells give rise to the embryonic disc and eventual embryo proper. They are pluripotent EMBRYONIC STEM CELLS capable of yielding many but not all cell types in a developing organism.
Transference of cells within an individual, between individuals of the same species, or between individuals of different species.
A trisaccharide antigen expressed on glycolipids and many cell-surface glycoproteins. In the blood the antigen is found on the surface of NEUTROPHILS; EOSINOPHILS; and MONOCYTES. In addition, CD15 antigen is a stage-specific embryonic antigen.
The quality of surface form or outline of CELLS.
A cytologic technique for measuring the functional capacity of stem cells by assaying their activity.
The founding member of the nodal signaling ligand family of proteins. Nodal protein was originally discovered in the region of the mouse embryo primitive streak referred to as HENSEN'S NODE. It is expressed asymmetrically on the left side in chordates and plays a critical role in the genesis of left-right asymmetry during vertebrate development.
Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.
Culture media containing biologically active components obtained from previously cultured cells or tissues that have released into the media substances affecting certain cell functions (e.g., growth, lysis).
Wnt proteins are a large family of secreted glycoproteins that play essential roles in EMBRYONIC AND FETAL DEVELOPMENT, and tissue maintenance. They bind to FRIZZLED RECEPTORS and act as PARACRINE PROTEIN FACTORS to initiate a variety of SIGNAL TRANSDUCTION PATHWAYS. The canonical Wnt signaling pathway stabilizes the transcriptional coactivator BETA CATENIN.
Small double-stranded, non-protein coding RNAs, 21-25 nucleotides in length generated from single-stranded microRNA gene transcripts by the same RIBONUCLEASE III, Dicer, that produces small interfering RNAs (RNA, SMALL INTERFERING). They become part of the RNA-INDUCED SILENCING COMPLEX and repress the translation (TRANSLATION, GENETIC) of target RNA by binding to homologous 3'UTR region as an imperfect match. The small temporal RNAs (stRNAs), let-7 and lin-4, from C. elegans, are the first 2 miRNAs discovered, and are from a class of miRNAs involved in developmental timing.
The artificial induction of GENE SILENCING by the use of RNA INTERFERENCE to reduce the expression of a specific gene. It includes the use of DOUBLE-STRANDED RNA, such as SMALL INTERFERING RNA and RNA containing HAIRPIN LOOP SEQUENCE, and ANTI-SENSE OLIGONUCLEOTIDES.
Proteins that are preferentially expressed or upregulated during FETAL DEVELOPMENT.
A family of zinc finger transcription factors that share homology with Kruppel protein, Drosophila. They contain a highly conserved seven amino acid spacer sequence in between their ZINC FINGER MOTIFS.
The creation of embryos specifically for research purposes.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
Genes whose expression is easily detectable and therefore used to study promoter activity at many positions in a target genome. In recombinant DNA technology, these genes may be attached to a promoter region of interest.
Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.
A GATA transcription factor that is expressed predominately in SMOOTH MUSCLE CELLS and regulates vascular smooth muscle CELL DIFFERENTIATION.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
A malignant neoplasm consisting of elements of teratoma with those of embryonal carcinoma or choriocarcinoma, or both. It occurs most often in the testis. (Dorland, 27th ed)
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
A family of proteins that play a role in CHROMATIN REMODELING. They are best known for silencing HOX GENES and the regulation of EPIGENETIC PROCESSES.
A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.
The outer of the three germ layers of an embryo.
A dosage compensation process occurring at an early embryonic stage in mammalian development whereby, at random, one X CHROMOSOME of the pair is repressed in the somatic cells of females.
Euploid male germ cells of an early stage of SPERMATOGENESIS, derived from prespermatogonia. With the onset of puberty, spermatogonia at the basement membrane of the seminiferous tubule proliferate by mitotic then meiotic divisions and give rise to the haploid SPERMATOCYTES.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Transplantation between individuals of the same species. Usually refers to genetically disparate individuals in contradistinction to isogeneic transplantation for genetically identical individuals.
Morphological and physiological development of EMBRYOS or FETUSES.
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.
Spherical, heterogeneous aggregates of proliferating, quiescent, and necrotic cells in culture that retain three-dimensional architecture and tissue-specific functions. The ability to form spheroids is a characteristic trait of CULTURED TUMOR CELLS derived from solid TUMORS. Cells from normal tissues can also form spheroids. They represent an in-vitro model for studies of the biology of both normal and malignant cells. (From Bjerkvig, Spheroid Culture in Cancer Research, 1992, p4)
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Genes that determine the fate of a cell or CELLS in a region of the embryo during EMBRYONIC DEVELOPMENT.
A technique for identifying specific DNA sequences that are bound, in vivo, to proteins of interest. It involves formaldehyde fixation of CHROMATIN to crosslink the DNA-BINDING PROTEINS to the DNA. After shearing the DNA into small fragments, specific DNA-protein complexes are isolated by immunoprecipitation with protein-specific ANTIBODIES. Then, the DNA isolated from the complex can be identified by PCR amplification and sequencing.
Transplantation of an individual's own tissue from one site to another site.
Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.
RNA which does not code for protein but has some enzymatic, structural or regulatory function. Although ribosomal RNA (RNA, RIBOSOMAL) and transfer RNA (RNA, TRANSFER) are also untranslated RNAs they are not included in this scope.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
'Nerve tissue proteins' are specialized proteins found within the nervous system's biological tissue, including neurofilaments, neuronal cytoskeletal proteins, and neural cell adhesion molecules, which facilitate structural support, intracellular communication, and synaptic connectivity essential for proper neurological function.
Transplantation of stem cells collected from the peripheral blood. It is a less invasive alternative to direct marrow harvesting of hematopoietic stem cells. Enrichment of stem cells in peripheral blood can be achieved by inducing mobilization of stem cells from the BONE MARROW.
The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
A complex signaling pathway whose name is derived from the DROSOPHILA Wg gene, which when mutated results in the wingless phenotype, and the vertebrate INT gene, which is located near integration sites of MOUSE MAMMARY TUMOR VIRUS. The signaling pathway is initiated by the binding of WNT PROTEINS to cells surface WNT RECEPTORS which interact with the AXIN SIGNALING COMPLEX and an array of second messengers that influence the actions of BETA CATENIN.
A Wnt protein subtype that plays a role in cell-cell signaling during EMBRYONIC DEVELOPMENT and the morphogenesis of the developing NEURAL TUBE.
A highly malignant, primitive form of carcinoma, probably of germinal cell or teratomatous derivation, usually arising in a gonad and rarely in other sites. It is rare in the female ovary, but in the male it accounts for 20% of all testicular tumors. (From Dorland, 27th ed & Holland et al., Cancer Medicine, 3d ed, p1595)
Transplantation between animals of different species.
Bipotential angio-hematopoietic stem cells that give rise to both HEMATOPOIETIC STEM CELLS and ENDOTHELIAL CELLS.
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A HEPARIN binding fibroblast growth factor that may play a role in LIMB BUDS development.
A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A strain of non-obese diabetic mice developed in Japan that has been widely studied as a model for T-cell-dependent autoimmune insulin-dependent diabetes mellitus in which insulitis is a major histopathologic feature, and in which genetic susceptibility is strongly MHC-linked.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A protein-tyrosine kinase receptor that is specific for STEM CELL FACTOR. This interaction is crucial for the development of hematopoietic, gonadal, and pigment stem cells. Genetic mutations that disrupt the expression of PROTO-ONCOGENE PROTEINS C-KIT are associated with PIEBALDISM, while overexpression or constitutive activation of the c-kit protein-tyrosine kinase is associated with tumorigenesis.
Connective tissue cells of an organ found in the loose connective tissue. These are most often associated with the uterine mucosa and the ovary as well as the hematopoietic system and elsewhere.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Interruption or suppression of the expression of a gene at transcriptional or translational levels.
A multi-functional catenin that participates in CELL ADHESION and nuclear signaling. Beta catenin binds CADHERINS and helps link their cytoplasmic tails to the ACTIN in the CYTOSKELETON via ALPHA CATENIN. It also serves as a transcriptional co-activator and downstream component of WNT PROTEIN-mediated SIGNAL TRANSDUCTION PATHWAYS.
An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.
The formation of cartilage. This process is directed by CHONDROCYTES which continually divide and lay down matrix during development. It is sometimes a precursor to OSTEOGENESIS.
A 200-230-kDa tyrosine kinase receptor for vascular endothelial growth factors found primarily in endothelial and hematopoietic cells and their precursors. VEGFR-2 is important for vascular and hematopoietic development, and mediates almost all endothelial cell responses to VEGF.
Interacting DNA-encoded regulatory subsystems in the GENOME that coordinate input from activator and repressor TRANSCRIPTION FACTORS during development, cell differentiation, or in response to environmental cues. The networks function to ultimately specify expression of particular sets of GENES for specific conditions, times, or locations.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
Directed modification of the gene complement of a living organism by such techniques as altering the DNA, substituting genetic material by means of a virus, transplanting whole nuclei, transplanting cell hybrids, etc.
The variable phenotypic expression of a GENE depending on whether it is of paternal or maternal origin, which is a function of the DNA METHYLATION pattern. Imprinted regions are observed to be more methylated and less transcriptionally active. (Segen, Dictionary of Modern Medicine, 1992)
The full set of CHROMOSOMES presented as a systematized array of METAPHASE chromosomes from a photomicrograph of a single CELL NUCLEUS arranged in pairs in descending order of size and according to the position of the CENTROMERE. (From Stedman, 25th ed)
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
A negative regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
A class of untranslated RNA molecules that are typically greater than 200 nucleotides in length and do not code for proteins. Members of this class have been found to play roles in transcriptional regulation, post-transcriptional processing, CHROMATIN REMODELING, and in the epigenetic control of chromatin.
Filaments 7-11 nm in diameter found in the cytoplasm of all cells. Many specific proteins belong to this group, e.g., desmin, vimentin, prekeratin, decamin, skeletin, neurofilin, neurofilament protein, and glial fibrillary acid protein.
An enzyme that catalyzes the transfer of a methyl group from S-ADENOSYLMETHIONINE to the 5-position of CYTOSINE residues in DNA.
Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
The process by which a person or group of persons comes to be regarded or treated as lacking in human qualities.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
An individual in which both alleles at a given locus are identical.
A GATA transcription factor that is expressed in the MYOCARDIUM of developing heart and has been implicated in the differentiation of CARDIAC MYOCYTES. GATA4 is activated by PHOSPHORYLATION and regulates transcription of cardiac-specific genes.
Signaling ligands that act in opposition to NODAL PROTEIN. During vertebrate development they regulate the degree of left-right asymmetry by controlling the spatiotemporal influence of NODAL PROTEIN.
A single-chain polypeptide growth factor that plays a significant role in the process of WOUND HEALING and is a potent inducer of PHYSIOLOGIC ANGIOGENESIS. Several different forms of the human protein exist ranging from 18-24 kDa in size due to the use of alternative start sites within the fgf-2 gene. It has a 55 percent amino acid residue identity to FIBROBLAST GROWTH FACTOR 1 and has potent heparin-binding activity. The growth factor is an extremely potent inducer of DNA synthesis in a variety of cell types from mesoderm and neuroectoderm lineages. It was originally named basic fibroblast growth factor based upon its chemical properties and to distinguish it from acidic fibroblast growth factor (FIBROBLAST GROWTH FACTOR 1).
Mice bearing mutant genes which are phenotypically expressed in the animals.
The development of new BLOOD VESSELS during the restoration of BLOOD CIRCULATION during the healing process.
Cells of epithelial origin possessing specialized sensory functions. They include cells that are found in the TASTE BUDS; OLFACTORY MUCOSA; COCHLEA; and NEUROEPITHELIAL BODIES.
A multisubunit polycomb protein complex that catalyzes the METHYLATION of chromosomal HISTONE H3. It works in conjunction with POLYCOMB REPRESSIVE COMPLEX 1 to effect EPIGENETIC REPRESSION.
Large, noncollagenous glycoprotein with antigenic properties. It is localized in the basement membrane lamina lucida and functions to bind epithelial cells to the basement membrane. Evidence suggests that the protein plays a role in tumor invasion.
The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type.
An agent that causes the production of physical defects in the developing embryo.
The simultaneous analysis, on a microchip, of multiple samples or targets arranged in an array format.

Isolation and characterization of the murine Nanog gene promoter. (1/5687)

Nanog protein is expressed in the interior cells of compacted morulae and maintained till epiblasts but downregulated by implantation stage. It is also expressed in embryonic stem cells, embryonic carcinoma cells and embryonic germ cells but disappeared in differentiated ES cells. In this study, we have isolated, sequenced, and performed the first characterization of the Nanog promoter. The transcription start sites were mapped by primer extension analysis. Two promoter regions were found upstream the transcription start sites and the expression of major Nanog promoter/reporter gene construct is abolished in differentiated F9 EC cells as compared to the undifferentiated counterpart. We also showed that a putative octamer motif (ATGCAAAA) is necessary for the major promoter activity. Gel shift and supershift assays showed that Oct-1, Oct-4 and Oct-6 protein selectively bind to the octamer motif.  (+info)

Human embryonic stem cell lines derived from the Chinese population. (2/5687)

Six human embryonic stem cell lines were established from surplus blastocysts. The cell lines expressed alkaline phosphatase and molecules typical of primate embryonic stem cells, including Oct-4, Nanog, TDGF1, Sox2, EBAF, Thy-1, FGF4, Rex-1, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. Five of the six lines formed embryoid bodies that expressed markers of a variety of cell types; four of them formed teratomas with tissue types representative of all three embryonic germ layers. These human embryonic stem cells are capable of producing clones of undifferentiated morphology, and one of them was propagated to become a subline. Human embryonic stem cell lines from the Chinese population should facilitate stem cell research and may be valuable in studies of population genetics and ecology.  (+info)

Derivation of multipotent mesenchymal precursors from human embryonic stem cells. (3/5687)

BACKGROUND: Human embryonic stem cells provide access to the earliest stages of human development and may serve as a source of specialized cells for regenerative medicine. Thus, it becomes crucial to develop protocols for the directed differentiation of embryonic stem cells into tissue-restricted precursors. METHODS AND FINDINGS: Here, we present culture conditions for the derivation of unlimited numbers of pure mesenchymal precursors from human embryonic stem cells and demonstrate multilineage differentiation into fat, cartilage, bone, and skeletal muscle cells. CONCLUSION: Our findings will help to elucidate the mechanism of mesoderm specification during embryonic stem cell differentiation and provide a platform to efficiently generate specialized human mesenchymal cell types for future clinical applications.  (+info)

Identification and isolation of embryonic stem cells in reproductive endocrinology: theoretical protocols for conservation of human embryos derived from in vitro fertilization. (4/5687)

BACKGROUND: Embryonic stem cells (ESC) are pluripotent cells obtained from the inner cell mass (ICM) of blastocysts derived from in vitro culture associated with reproductive endocrinology therapy. Human ESCs are regarded as highly significant since they retain the capacity to differentiate into any of approximately 200 unique cell types. Human ESC research is controversial because to acquire such cells, the ICM of human blastocysts must be manipulated in a way that renders embryos nonviable and unsuitable for transfer in utero. Techniques to yield competent ESCs with conservation of source blastocysts would satisfy many objections against ESC research, but at present such approaches remain largely untested. RESULTS AND DISCUSSION: We contrast experimental culture of single blastomeres obtained by 1) non-destructive biopsy of embryos destined for transfer, and 2) isolation of karyotypically normal blastomeres from disaggregated ("dead") embryos considered unsuitable for transfer, and evaluate these approaches with regard to production of ESCs. Pluripotency was confirmed by morphological criteria and by quantification of divergent homeodomain proteins specific to undifferentiated cell development. Following ESC isolation and identification, assessment was conducted according to a novel ESC grading system, also proposed here. CONCLUSION: The role of reproductive endocrinology in ESC research remains paramount. In this report, we hypothesize new and expand on existing strategies having the potential to enhance human ESC isolation, identification and in vitro maintenance.  (+info)

LIF and BMP signaling generate separate and discrete types of GFAP-expressing cells. (5/5687)

Bone morphogenetic protein (BMP) and leukemia inhibitory factor (LIF) signaling both promote the differentiation of neural stem/progenitor cells into glial fibrillary acidic protein (GFAP) immunoreactive cells. This study compares the cellular and molecular characteristics, and the potentiality, of GFAP(+) cells generated by these different signaling pathways. Treatment of cultured embryonic subventricular zone (SVZ) progenitor cells with LIF generates GFAP(+) cells that have a bipolar/tripolar morphology, remain in cell cycle, contain progenitor cell markers and demonstrate self-renewal with enhanced neurogenesis - characteristics that are typical of adult SVZ and subgranular zone (SGZ) stem cells/astrocytes. By contrast, BMP-induced GFAP(+) cells are stellate, exit the cell cycle, and lack progenitor traits and self-renewal--characteristics that are typical of astrocytes in the non-neurogenic adult cortex. In vivo, transgenic overexpression of BMP4 increases the number of GFAP(+) astrocytes but depletes the GFAP(+) progenitor cell pool, whereas transgenic inhibition of BMP signaling increases the size of the GFAP(+) progenitor cell pool but reduces the overall numbers of astrocytes. We conclude that LIF and BMP signaling generate different astrocytic cell types, and propose that these cells are, respectively, adult progenitor cells and mature astrocytes.  (+info)

Embryonic stem cells cultured in biodegradable scaffold repair infarcted myocardium in mice. (6/5687)

Our previous findings demonstrated that directly injecting embryonic stem cells (ESCs) into ischemic region of the heart improved cardiac function in animals with experimental myocardial infarction (MI). Tissue engineering with stem cells may provide tissue creation and repair. This study was designed to investigate the effectiveness of grafting of ESC-seeded biodegradable patch on infarcted heart. MI in mice was induced by ligation of the left coronary artery. Mouse ESCs were seeded on polyglycolic-acid (PGA) material patches. Three days after culture, an ESC-seeded patch was transplanted on the surface of ischemic and peri-ischemic myocardium. Eight weeks after MI operation and patch transplantation, hemodynamics and cardiac function were evaluated in four (sham-operated, MI, MI + cell-free patch, and MI + ESC-patch) groups of mice. The blood pressure and left ventricular function were significantly reduced in the MI animals. Compared with MI alone and MI + cell-free patch groups, the animals received MI + ESC-seeded patches significantly improved blood pressure and ventricular function. The survival rate of the MI mice grafted with MI + ESC-seeded patches was markedly higher than that in MI alone or MI + cell-free patch animals. GFP-positive tissue was detected in infarcted area with grafting of ESC-seeded patch, which suggests the survivors of ESCs and possible myocardial regeneration. Our data demonstrate that grafting of ESC-seeded bioabsorbable patch can repair infarcted myocardium and improve cardiac function in MI mice. This novel approach of combining stem cells and biodegradable materials may provide a therapeutic modality for repairing injured heart.  (+info)

Neural induction promotes large-scale chromatin reorganisation of the Mash1 locus. (7/5687)

Determining how genes are epigenetically regulated to ensure their correct spatial and temporal expression during development is key to our understanding of cell lineage commitment. Here we examined epigenetic changes at an important proneural regulator gene Mash1 (Ascl1), as embryonic stem (ES) cells commit to the neural lineage. In ES cells where the Mash1 gene is transcriptionally repressed, the locus replicated late in S phase and was preferentially positioned at the nuclear periphery with other late-replicating genes (Neurod, Sprr2a). This peripheral location was coupled with low levels of histone H3K9 acetylation at the Mash1 promoter and enhanced H3K27 methylation but surprisingly location was not affected by removal of the Ezh2/Eed HMTase complex or several other chromatin-silencing candidates (G9a, SuV39h-1, Dnmt-1, Dnmt-3a and Dnmt-3b). Upon neural induction however, Mash1 transcription was upregulated (>100-fold), switched its time of replication from late to early in S phase and relocated towards the interior of the nucleus. This spatial repositioning was selective for neural commitment because Mash1 was peripheral in ES-derived mesoderm and other non-neural cell types. A bidirectional analysis of replication timing across a 2 Mb region flanking the Mash1 locus showed that chromatin changes were focused at Mash1. These results suggest that Mash1 is regulated by changes in chromatin structure and location and implicate the nuclear periphery as an important environment for maintaining the undifferentiated state of ES cells.  (+info)

Transcriptional profiling of reporter genes used for molecular imaging of embryonic stem cell transplantation. (8/5687)

Stem cell therapy offers exciting promise for treatment of ischemic heart disease. Recent advances in molecular imaging techniques now allow investigators to monitor cell fate noninvasively and repetitively. Here we examine the effects of a triple-fusion reporter gene on embryonic stem (ES) cell transcriptional profiles. Murine ES cells were stably transfected with a self-inactivating lentiviral vector carrying a triple-fusion (TF) construct consisting of fluorescence, bioluminescence, and positron emission tomography (PET) reporter genes. Fluorescence-activated cell sorting (FACS) analysis allowed isolation of stably transfected populations. Microarray studies comparing gene expression in nontransduced control ES cells vs. stably transduced ES cells expressing triple fusion (ES-TF) revealed some increases in transcriptional variability. Annotation analysis showed that ES-TF cells downregulated cell cycling, cell death, and protein and nucleic acid metabolism genes while upregulating homeostatic and anti-apoptosis genes. Despite these transcriptional changes, expression of the TF reporter gene had no significant effects on ES cell viability, proliferation, and differentiation capability. Importantly, transplantation studies in murine myocardium demonstrated the feasibility of tracking ES-TF cells in living subjects using bioluminescence and PET imaging. Taken together, this is the first study to analyze in detail the effects of reporter genes on molecular imaging of ES cells.  (+info)

Embryonic stem cells are a type of pluripotent stem cell that are derived from the inner cell mass of a blastocyst, which is a very early-stage embryo. These cells have the ability to differentiate into any cell type in the body, making them a promising area of research for regenerative medicine and the study of human development and disease. Embryonic stem cells are typically obtained from surplus embryos created during in vitro fertilization (IVF) procedures, with the consent of the donors. The use of embryonic stem cells is a controversial issue due to ethical concerns surrounding the destruction of human embryos.

According to the National Institutes of Health (NIH), stem cells are "initial cells" or "precursor cells" that have the ability to differentiate into many different cell types in the body. They can also divide without limit to replenish other cells for as long as the person or animal is still alive.

There are two main types of stem cells: embryonic stem cells, which come from human embryos, and adult stem cells, which are found in various tissues throughout the body. Embryonic stem cells have the ability to differentiate into all cell types in the body, while adult stem cells have more limited differentiation potential.

Stem cells play an essential role in the development and repair of various tissues and organs in the body. They are currently being studied for their potential use in the treatment of a wide range of diseases and conditions, including cancer, diabetes, heart disease, and neurological disorders. However, more research is needed to fully understand the properties and capabilities of these cells before they can be used safely and effectively in clinical settings.

Cell differentiation is the process by which a less specialized cell, or stem cell, becomes a more specialized cell type with specific functions and structures. This process involves changes in gene expression, which are regulated by various intracellular signaling pathways and transcription factors. Differentiation results in the development of distinct cell types that make up tissues and organs in multicellular organisms. It is a crucial aspect of embryonic development, tissue repair, and maintenance of homeostasis in the body.

Pluripotent stem cells are a type of undifferentiated stem cell that have the ability to differentiate into any cell type of the three germ layers (endoderm, mesoderm, and ectoderm) of a developing embryo. These cells can give rise to all the cell types that make up the human body, with the exception of those that form the extra-embryonic tissues such as the placenta.

Pluripotent stem cells are characterized by their ability to self-renew, which means they can divide and produce more pluripotent stem cells, and differentiate, which means they can give rise to specialized cell types with specific functions. Pluripotent stem cells can be derived from embryos at the blastocyst stage of development or generated in the lab through a process called induced pluripotency, where adult cells are reprogrammed to have the properties of embryonic stem cells.

Pluripotent stem cells hold great promise for regenerative medicine and tissue engineering because they can be used to generate large numbers of specific cell types that can potentially replace or repair damaged or diseased tissues in the body. However, their use is still a subject of ethical debate due to concerns about the source of embryonic stem cells and the potential risks associated with their use in clinical applications.

Stem cell transplantation is a medical procedure where stem cells, which are immature and unspecialized cells with the ability to differentiate into various specialized cell types, are introduced into a patient. The main purpose of this procedure is to restore the function of damaged or destroyed tissues or organs, particularly in conditions that affect the blood and immune systems, such as leukemia, lymphoma, aplastic anemia, and inherited metabolic disorders.

There are two primary types of stem cell transplantation: autologous and allogeneic. In autologous transplantation, the patient's own stem cells are collected, stored, and then reinfused back into their body after high-dose chemotherapy or radiation therapy to destroy the diseased cells. In allogeneic transplantation, stem cells are obtained from a donor (related or unrelated) whose human leukocyte antigen (HLA) type closely matches that of the recipient.

The process involves several steps: first, the patient undergoes conditioning therapy to suppress their immune system and make space for the new stem cells. Then, the harvested stem cells are infused into the patient's bloodstream, where they migrate to the bone marrow and begin to differentiate and produce new blood cells. This procedure requires close monitoring and supportive care to manage potential complications such as infections, graft-versus-host disease, and organ damage.

A mammalian embryo is the developing offspring of a mammal, from the time of implantation of the fertilized egg (blastocyst) in the uterus until the end of the eighth week of gestation. During this period, the embryo undergoes rapid cell division and organ differentiation to form a complex structure with all the major organs and systems in place. This stage is followed by fetal development, which continues until birth. The study of mammalian embryos is important for understanding human development, evolution, and reproductive biology.

Octamer Transcription Factor-3 (OTF-3 or Oct3) is a specific protein that belongs to the class of POU domain transcription factors. These proteins play crucial roles in the regulation of gene expression during cell growth, development, and differentiation. The "POU" name refers to the presence of two conserved domains - a POU-specific domain and a POU homeodomain - that recognize and bind to specific DNA sequences called octamer motifs, which are involved in controlling the transcription of target genes.

Oct3, encoded by the Pou2f1 gene, is widely expressed in various tissues, including lymphoid cells, neurons, and embryonic stem cells. It has been shown to regulate the expression of several genes that are essential for cell survival, proliferation, and differentiation. Dysregulation of Oct3 has been implicated in several diseases, such as cancers and neurological disorders.

In summary, Octamer Transcription Factor-3 (Oct3) is a POU domain transcription factor that binds to octamer motifs in DNA and regulates the expression of target genes involved in cell growth, development, and differentiation.

Hematopoietic stem cells (HSCs) are immature, self-renewing cells that give rise to all the mature blood and immune cells in the body. They are capable of both producing more hematopoietic stem cells (self-renewal) and differentiating into early progenitor cells that eventually develop into red blood cells, white blood cells, and platelets. HSCs are found in the bone marrow, umbilical cord blood, and peripheral blood. They have the ability to repair damaged tissues and offer significant therapeutic potential for treating various diseases, including hematological disorders, genetic diseases, and cancer.

Induced Pluripotent Stem Cells (iPSCs) are a type of pluripotent stem cells that are generated from somatic cells, such as skin or blood cells, through the introduction of specific genes encoding transcription factors. These reprogrammed cells exhibit similar characteristics to embryonic stem cells, including the ability to differentiate into any cell type of the three germ layers (endoderm, mesoderm, and ectoderm). The discovery and development of iPSCs have opened up new possibilities in regenerative medicine, drug testing and development, and disease modeling, while avoiding ethical concerns associated with embryonic stem cells.

'Cell lineage' is a term used in biology and medicine to describe the developmental history or relationship of a cell or group of cells to other cells, tracing back to the original progenitor or stem cell. It refers to the series of cell divisions and differentiation events that give rise to specific types of cells in an organism over time.

In simpler terms, cell lineage is like a family tree for cells, showing how they are related to each other through a chain of cell division and specialization events. This concept is important in understanding the development, growth, and maintenance of tissues and organs in living beings.

Cell culture is a technique used in scientific research to grow and maintain cells from plants, animals, or humans in a controlled environment outside of their original organism. This environment typically consists of a sterile container called a cell culture flask or plate, and a nutrient-rich liquid medium that provides the necessary components for the cells' growth and survival, such as amino acids, vitamins, minerals, and hormones.

There are several different types of cell culture techniques used in research, including:

1. Adherent cell culture: In this technique, cells are grown on a flat surface, such as the bottom of a tissue culture dish or flask. The cells attach to the surface and spread out, forming a monolayer that can be observed and manipulated under a microscope.
2. Suspension cell culture: In suspension culture, cells are grown in liquid medium without any attachment to a solid surface. These cells remain suspended in the medium and can be agitated or mixed to ensure even distribution of nutrients.
3. Organoid culture: Organoids are three-dimensional structures that resemble miniature organs and are grown from stem cells or other progenitor cells. They can be used to study organ development, disease processes, and drug responses.
4. Co-culture: In co-culture, two or more different types of cells are grown together in the same culture dish or flask. This technique is used to study cell-cell interactions and communication.
5. Conditioned medium culture: In this technique, cells are grown in a medium that has been conditioned by previous cultures of other cells. The conditioned medium contains factors secreted by the previous cells that can influence the growth and behavior of the new cells.

Cell culture techniques are widely used in biomedical research to study cellular processes, develop drugs, test toxicity, and investigate disease mechanisms. However, it is important to note that cell cultures may not always accurately represent the behavior of cells in a living organism, and results from cell culture experiments should be validated using other methods.

Adult stem cells, also known as somatic stem cells, are undifferentiated cells found in specialized tissues or organs throughout the body of a developed organism. Unlike embryonic stem cells, which are derived from blastocysts and have the ability to differentiate into any cell type in the body (pluripotency), adult stem cells are typically more limited in their differentiation potential, meaning they can only give rise to specific types of cells within the tissue or organ where they reside.

Adult stem cells serve to maintain and repair tissues by replenishing dying or damaged cells. They can divide and self-renew over time, producing one daughter cell that remains a stem cell and another that differentiates into a mature, functional cell type. The most well-known adult stem cells are hematopoietic stem cells, which give rise to all types of blood cells, and mesenchymal stem cells, which can differentiate into various connective tissue cells such as bone, cartilage, fat, and muscle.

The potential therapeutic use of adult stem cells has been explored in various medical fields, including regenerative medicine and cancer therapy. However, their limited differentiation capacity and the challenges associated with isolating and expanding them in culture have hindered their widespread application. Recent advances in stem cell research, such as the development of techniques to reprogram adult cells into induced pluripotent stem cells (iPSCs), have opened new avenues for studying and harnessing the therapeutic potential of these cells.

Embryoid bodies are aggregates of pluripotent stem cells, such as embryonic stem cells or induced pluripotent stem cells, that have been cultured in suspension and allowed to differentiate spontaneously into three-dimensional structures. These structures resemble early embryonic development and can contain cells from all three germ layers: ectoderm, mesoderm, and endoderm. Embryoid bodies are often used as a tool in stem cell research to study the processes of differentiation and organogenesis.

Neural stem cells (NSCs) are a type of undifferentiated cells found in the central nervous system, including the brain and spinal cord. They have the ability to self-renew and generate the main types of cells found in the nervous system, such as neurons, astrocytes, and oligodendrocytes. NSCs are capable of dividing symmetrically to increase their own population or asymmetrically to produce one stem cell and one differentiated cell. They play a crucial role in the development and maintenance of the nervous system, and have the potential to be used in regenerative medicine and therapies for neurological disorders and injuries.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Embryo research refers to the scientific study and experimentation that involves human embryos. This research is conducted in order to gain a better understanding of human development during the earliest stages of life, as well as to investigate potential treatments for various diseases and conditions.

Human embryos used in research are typically created through in vitro fertilization (IVF) procedures, in which sperm and eggs are combined in a laboratory dish to form an embryo. These embryos may be donated by individuals or couples who have undergone IVF treatments and have excess embryos that they do not plan to use for reproduction.

Embryo research can involve a variety of techniques, including stem cell research, genetic testing, and cloning. The goal of this research is to advance our knowledge of human development and disease, as well as to develop new treatments and therapies for a wide range of medical conditions. However, embryo research is a controversial topic, and there are ethical concerns surrounding the use of human embryos in scientific research.

SOXB1 transcription factors are a subgroup of the SOX (SRY-related HMG box) family of transcription factors, which are characterized by a conserved high mobility group (HMG) box DNA-binding domain. The SOXB1 subfamily includes SOX1, SOX2, and SOX3, which play crucial roles during embryonic development and in the maintenance of stem cells. They regulate gene expression by binding to specific DNA sequences and interacting with other transcription factors and cofactors. SOXB1 proteins have been implicated in various biological processes, such as neurogenesis, eye development, and sex determination. Dysregulation of SOXB1 transcription factors has been associated with several human diseases, including cancer.

Developmental gene expression regulation refers to the processes that control the activation or repression of specific genes during embryonic and fetal development. These regulatory mechanisms ensure that genes are expressed at the right time, in the right cells, and at appropriate levels to guide proper growth, differentiation, and morphogenesis of an organism.

Developmental gene expression regulation is a complex and dynamic process involving various molecular players, such as transcription factors, chromatin modifiers, non-coding RNAs, and signaling molecules. These regulators can interact with cis-regulatory elements, like enhancers and promoters, to fine-tune the spatiotemporal patterns of gene expression during development.

Dysregulation of developmental gene expression can lead to various congenital disorders and developmental abnormalities. Therefore, understanding the principles and mechanisms governing developmental gene expression regulation is crucial for uncovering the etiology of developmental diseases and devising potential therapeutic strategies.

A teratoma is a type of germ cell tumor, which is a broad category of tumors that originate from the reproductive cells. A teratoma contains developed tissues from all three embryonic germ layers: ectoderm, mesoderm, and endoderm. This means that a teratoma can contain various types of tissue such as hair, teeth, bone, and even more complex organs like eyes, thyroid, or neural tissue.

Teratomas are usually benign (non-cancerous), but they can sometimes be malignant (cancerous) and can spread to other parts of the body. They can occur anywhere in the body, but they're most commonly found in the ovaries and testicles. When found in these areas, they are typically removed surgically.

Teratomas can also occur in other locations such as the sacrum, coccyx (tailbone), mediastinum (the area between the lungs), and pineal gland (a small gland in the brain). These types of teratomas can be more complex to treat due to their location and potential to cause damage to nearby structures.

Multipotent stem cells are a type of stem cell that have the ability to differentiate into multiple cell types, but are more limited than pluripotent stem cells. These stem cells are found in various tissues and organs throughout the body, including bone marrow, adipose tissue, and dental pulp. They can give rise to a number of different cell types within their own germ layer (endoderm, mesoderm, or ectoderm), but cannot cross germ layer boundaries. For example, multipotent stem cells found in bone marrow can differentiate into various blood cells such as red and white blood cells, but they cannot differentiate into nerve cells or liver cells. These stem cells play important roles in tissue repair and regeneration, and have potential therapeutic applications in regenerative medicine.

A stem cell niche is a specific microenvironment in which stem cells reside, interact with surrounding cells and receive molecular signals that regulate their self-renewal, proliferation, differentiation, and survival. This specialized niche provides the necessary conditions for maintaining the undifferentiated state of stem cells and controlling their fate decisions. The components of a stem cell niche typically include various cell types (such as supporting cells, immune cells, and blood vessels), extracellular matrix proteins, signaling molecules, and physical factors like oxygen tension and mechanical stress. Together, these elements create a unique microenvironment that helps to preserve the functional integrity and potential of stem cells for tissue repair, regeneration, and homeostasis.

Hematopoietic Stem Cell Transplantation (HSCT) is a medical procedure where hematopoietic stem cells (immature cells that give rise to all blood cell types) are transplanted into a patient. This procedure is often used to treat various malignant and non-malignant disorders affecting the hematopoietic system, such as leukemias, lymphomas, multiple myeloma, aplastic anemia, inherited immune deficiency diseases, and certain genetic metabolic disorders.

The transplantation can be autologous (using the patient's own stem cells), allogeneic (using stem cells from a genetically matched donor, usually a sibling or unrelated volunteer), or syngeneic (using stem cells from an identical twin).

The process involves collecting hematopoietic stem cells, most commonly from the peripheral blood or bone marrow. The collected cells are then infused into the patient after the recipient's own hematopoietic system has been ablated (or destroyed) using high-dose chemotherapy and/or radiation therapy. This allows the donor's stem cells to engraft, reconstitute, and restore the patient's hematopoietic system.

HSCT is a complex and potentially risky procedure with various complications, including graft-versus-host disease, infections, and organ damage. However, it offers the potential for cure or long-term remission in many patients with otherwise fatal diseases.

Totipotent stem cells are a type of stem cell that have the greatest developmental potential and can differentiate into any cell type in the body, including extra-embryonic tissues such as the placenta. These stem cells are derived from the fertilized egg (zygote) and are capable of forming a complete organism. As development progresses, totipotent stem cells become more restricted in their differentiation potential, giving rise to pluripotent stem cells, which can differentiate into any cell type in the body but not extra-embryonic tissues. Totipotent stem cells are rarely found in adults and are primarily studied in the context of embryonic development and regenerative medicine.

Homeodomain proteins are a group of transcription factors that play crucial roles in the development and differentiation of cells in animals and plants. They are characterized by the presence of a highly conserved DNA-binding domain called the homeodomain, which is typically about 60 amino acids long. The homeodomain consists of three helices, with the third helix responsible for recognizing and binding to specific DNA sequences.

Homeodomain proteins are involved in regulating gene expression during embryonic development, tissue maintenance, and organismal growth. They can act as activators or repressors of transcription, depending on the context and the presence of cofactors. Mutations in homeodomain proteins have been associated with various human diseases, including cancer, congenital abnormalities, and neurological disorders.

Some examples of homeodomain proteins include PAX6, which is essential for eye development, HOX genes, which are involved in body patterning, and NANOG, which plays a role in maintaining pluripotency in stem cells.

Cell proliferation is the process by which cells increase in number, typically through the process of cell division. In the context of biology and medicine, it refers to the reproduction of cells that makes up living tissue, allowing growth, maintenance, and repair. It involves several stages including the transition from a phase of quiescence (G0 phase) to an active phase (G1 phase), DNA replication in the S phase, and mitosis or M phase, where the cell divides into two daughter cells.

Abnormal or uncontrolled cell proliferation is a characteristic feature of many diseases, including cancer, where deregulated cell cycle control leads to excessive and unregulated growth of cells, forming tumors that can invade surrounding tissues and metastasize to distant sites in the body.

Germ layers refer to the primary layers of cells that form during embryonic development and give rise to the various tissues and organs in the body. In humans, there are three germ layers: the ectoderm, mesoderm, and endoderm. Each germ layer differentiates into distinct cell types and structures during the process of gastrulation. The ectoderm gives rise to the nervous system, sensory organs, and skin; the mesoderm forms muscles, bones, blood vessels, and the circulatory system; and the endoderm develops into the respiratory and digestive systems, including the lungs, liver, and pancreas.

Mesenchymal Stromal Cells (MSCs) are a type of adult stem cells found in various tissues, including bone marrow, adipose tissue, and umbilical cord blood. They have the ability to differentiate into multiple cell types, such as osteoblasts, chondrocytes, and adipocytes, under specific conditions. MSCs also possess immunomodulatory properties, making them a promising tool in regenerative medicine and therapeutic strategies for various diseases, including autoimmune disorders and tissue injuries. It is important to note that the term "Mesenchymal Stem Cells" has been replaced by "Mesenchymal Stromal Cells" in the scientific community to better reflect their biological characteristics and potential functions.

Mesenchymal Stem Cell Transplantation (MSCT) is a medical procedure that involves the transplantation of mesenchymal stem cells (MSCs), which are multipotent stromal cells that can differentiate into a variety of cell types, including bone, cartilage, fat, and muscle. These cells can be obtained from various sources, such as bone marrow, adipose tissue, umbilical cord blood, or dental pulp.

In MSCT, MSCs are typically harvested from the patient themselves (autologous transplantation) or from a donor (allogeneic transplantation). The cells are then processed and expanded in a laboratory setting before being injected into the patient's body, usually through an intravenous infusion.

MSCT is being investigated as a potential treatment for a wide range of medical conditions, including degenerative diseases, autoimmune disorders, and tissue injuries. The rationale behind this approach is that MSCs have the ability to migrate to sites of injury or inflammation, where they can help to modulate the immune response, reduce inflammation, and promote tissue repair and regeneration.

However, it's important to note that while MSCT holds promise as a therapeutic option, more research is needed to establish its safety and efficacy for specific medical conditions.

Endoderm is the innermost of the three primary germ layers in a developing embryo, along with the ectoderm and mesoderm. The endoderm gives rise to several internal tissues and organs, most notably those found in the digestive system and respiratory system. Specifically, it forms the lining of the gut tube, which eventually becomes the epithelial lining of the gastrointestinal tract, liver, pancreas, lungs, and other associated structures.

During embryonic development, the endoderm arises from the inner cell mass of the blastocyst, following a series of cell divisions and migrations that help to establish the basic body plan of the organism. As the embryo grows and develops, the endoderm continues to differentiate into more specialized tissues and structures, playing a critical role in the formation of many essential bodily functions.

Leukemia Inhibitory Factor (LIF) is a protein with pleiotropic functions, acting as a cytokine that plays a crucial role in various biological processes. Its name originates from its initial discovery as a factor that inhibits the proliferation of certain leukemic cells. However, LIF has been found to have a much broader range of activities beyond just inhibiting leukemia cells.

LIF is a member of the interleukin-6 (IL-6) family of cytokines and binds to a heterodimeric receptor complex consisting of the LIF receptor (LIFR) and glycoprotein 130 (gp130). The activation of this receptor complex triggers several downstream signaling pathways, including the Janus kinase (JAK)-signal transducer and activator of transcription (STAT), mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K) pathways.

Some of the key functions of LIF include:

1. Embryonic development: During embryogenesis, LIF is essential for maintaining the pluripotency of embryonic stem cells and promoting their self-renewal in the early stages of development. It also plays a role in implantation and trophoblast differentiation during pregnancy.
2. Hematopoiesis: In the hematopoietic system, LIF supports the survival and proliferation of hematopoietic stem cells (HSCs) and regulates their differentiation into various blood cell lineages.
3. Neuroprotection and neurogenesis: LIF has been shown to have neuroprotective effects in various models of neuronal injury and disease, including spinal cord injury, stroke, and Alzheimer's disease. It also promotes the survival and differentiation of neural progenitor cells, contributing to adult neurogenesis.
4. Inflammation: LIF is involved in regulating immune responses and inflammation by modulating the activation and function of various immune cells, such as T cells, B cells, macrophages, and dendritic cells.
5. Pain regulation: LIF has been implicated in pain processing and modulation, with studies suggesting that it may contribute to both acute and chronic pain conditions.
6. Cancer: LIF has complex roles in cancer biology, acting as a tumor suppressor in some contexts while promoting tumor growth and progression in others. It can regulate various aspects of cancer cell behavior, including proliferation, survival, migration, and invasion.

In summary, LIF is a pleiotropic cytokine with diverse functions in various biological processes, including embryonic development, hematopoiesis, neuroprotection, inflammation, pain regulation, and cancer. Its multifaceted roles highlight the importance of understanding its precise mechanisms of action in different contexts to harness its therapeutic potential for various diseases.

Stem cell research is a branch of medical science that focuses on the study and application of stem cells, which are undifferentiated or unspecialized cells with the ability to differentiate into various specialized cell types in the body. These cells have the potential to regenerate and repair damaged tissues and organs, making them a promising area of research for the development of new treatments for a wide range of diseases and conditions, including cancer, neurodegenerative disorders, diabetes, heart disease, and more.

Stem cell research involves several key areas, such as:

1. Isolation and culture: Scientists isolate stem cells from various sources, such as embryos, umbilical cord blood, or adult tissues, and grow them in a lab to study their properties and behaviors.
2. Differentiation: Researchers induce stem cells to differentiate into specific cell types, such as heart cells, brain cells, or pancreatic cells, by exposing them to various growth factors and other chemical signals.
3. Genetic modification: Scientists may modify the genes of stem cells to enhance their therapeutic potential or to study the effects of genetic mutations on cell behavior and development.
4. Transplantation: In some cases, researchers transplant stem cells into animal models or human patients to investigate their ability to repair damaged tissues and organs.
5. Ethical considerations: Stem cell research raises several ethical concerns related to the use of embryonic stem cells, which are derived from human embryos. These concerns have led to ongoing debates about the limits and regulations surrounding this area of research.

Overall, stem cell research holds great promise for the development of new medical treatments and therapies, but it also requires careful consideration of ethical issues and rigorous scientific investigation to ensure its safety and effectiveness.

A chimera, in the context of medicine and biology, is a single organism that is composed of cells with different genetics. This can occur naturally in some situations, such as when fraternal twins do not fully separate in utero and end up sharing some organs or tissues. The term "chimera" can also refer to an organism that contains cells from two different species, which can happen in certain types of genetic research or medical treatments. For example, a patient's cells might be genetically modified in a lab and then introduced into their body to treat a disease; if some of these modified cells mix with the patient's original cells, the result could be a chimera.

It's worth noting that the term "chimera" comes from Greek mythology, where it referred to a fire-breathing monster that was part lion, part goat, and part snake. In modern scientific usage, the term has a specific technical meaning related to genetics and organisms, but it may still evoke images of fantastical creatures for some people.

Gene targeting is a research technique in molecular biology used to precisely modify specific genes within the genome of an organism. This technique allows scientists to study gene function by creating targeted genetic changes, such as insertions, deletions, or mutations, in a specific gene of interest. The process typically involves the use of engineered nucleases, such as CRISPR-Cas9 or TALENs, to introduce double-stranded breaks at desired locations within the genome. These breaks are then repaired by the cell's own DNA repair machinery, often leading to the incorporation of designed changes in the targeted gene. Gene targeting is a powerful tool for understanding gene function and has wide-ranging applications in basic research, agriculture, and therapeutic development.

Gene expression profiling is a laboratory technique used to measure the activity (expression) of thousands of genes at once. This technique allows researchers and clinicians to identify which genes are turned on or off in a particular cell, tissue, or organism under specific conditions, such as during health, disease, development, or in response to various treatments.

The process typically involves isolating RNA from the cells or tissues of interest, converting it into complementary DNA (cDNA), and then using microarray or high-throughput sequencing technologies to determine which genes are expressed and at what levels. The resulting data can be used to identify patterns of gene expression that are associated with specific biological states or processes, providing valuable insights into the underlying molecular mechanisms of diseases and potential targets for therapeutic intervention.

In recent years, gene expression profiling has become an essential tool in various fields, including cancer research, drug discovery, and personalized medicine, where it is used to identify biomarkers of disease, predict patient outcomes, and guide treatment decisions.

Stem Cell Factor (SCF), also known as Kit Ligand or Steel Factor, is a growth factor that plays a crucial role in the regulation of hematopoiesis, which is the process of producing various blood cells. It is a glycoprotein that binds to the c-Kit receptor found on hematopoietic stem cells and progenitor cells, promoting their survival, proliferation, and differentiation into mature blood cells.

SCF is involved in the development and function of several types of blood cells, including red blood cells, white blood cells, and platelets. It also plays a role in the maintenance and self-renewal of hematopoietic stem cells, which are essential for the continuous production of new blood cells throughout an individual's lifetime.

In addition to its role in hematopoiesis, SCF has been implicated in various other biological processes, such as melanogenesis, gametogenesis, and tissue repair and regeneration. Dysregulation of SCF signaling has been associated with several diseases, including certain types of cancer, bone marrow failure disorders, and autoimmune diseases.

Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.

A blastocyst is a stage in the early development of a fertilized egg, or embryo, in mammals. It occurs about 5-6 days after fertilization and consists of an outer layer of cells called trophoblasts, which will eventually form the placenta, and an inner cell mass, which will give rise to the fetus. The blastocyst is characterized by a fluid-filled cavity called the blastocoel. This stage is critical for the implantation of the embryo into the uterine lining.

Stage-Specific Embryonic Antigens (SSEAs) are a type of antigens that are found on the surface of early embryonic cells during specific stages of development. These antigens were first discovered in mouse embryos and are expressed in a stage-specific manner, meaning they appear and disappear at specific times during embryonic development.

SSEAs are classified into different types based on their carbohydrate structures, including SSEA-1, SSEA-3, SSEA-4, and SSEA-5. These antigens have been found to be important markers for identifying the stage of embryonic development and have been used in research to study early embryonic development, stem cell biology, and cancer.

In particular, SSEAs have been identified as markers for pluripotent stem cells, which are cells that have the ability to differentiate into any type of cell in the body. These antigens are often used to isolate and characterize pluripotent stem cells, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs).

It's worth noting that SSEAs have also been found to be expressed in some types of cancer cells, suggesting a potential role in tumor growth and progression. However, more research is needed to fully understand the function and significance of these antigens in both embryonic development and cancer.

Nuclear reprogramming is a process by which the epigenetic information and gene expression profile of a differentiated cell are altered to resemble those of a pluripotent stem cell. This is typically achieved through the introduction of specific transcription factors, such as Oct4, Sox2, Klf4, and c-Myc (often referred to as the Yamanaka factors), into the differentiated cell's nucleus. These factors work together to reprogram the cell's gene expression profile, leading to the activation of genes that are typically silent in differentiated cells and the repression of genes that are active in differentiated cells.

The result is a cell with many of the characteristics of a pluripotent stem cell, including the ability to differentiate into any cell type found in the body. This process has significant implications for regenerative medicine, as it offers the potential to generate patient-specific stem cells that can be used for tissue repair and replacement. However, nuclear reprogramming is still an inefficient and poorly understood process, and further research is needed to fully realize its potential.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.

The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.

In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.

RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.

Feeder cells are typically used in cell culture to support the growth and survival of other cells, often called "dependent" or "target" cells. These feeder cells are usually mitotically inactivated, so they do not proliferate themselves but provide a supportive microenvironment for the dependent cells through the secretion of various growth factors, cytokines, and extracellular matrix proteins.

A common application of feeder cells is to support the growth and maintenance of stem cells or primary cell cultures, which can have specific nutrient and growth factor requirements that are difficult to meet with traditional culture methods. Feeder cells may also be used in the production of certain therapeutic products, such as viral vectors for gene therapy, where they provide a substrate for efficient virus replication.

Some common types of feeder cells include fibroblasts (such as mouse embryonic fibroblasts or human foreskin fibroblasts), which are often used to culture stem cells and primary cells; and 3T3-J2 cells, a specific line of mouse embryonic fibroblasts that have been widely used in the culture of hematopoietic stem cells.

It's important to note that the use of feeder cells can introduce potential risks, such as contamination with adventitious agents or unwanted cell types, which must be carefully managed and controlled during cell culture procedures.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Regenerative medicine is a branch of medicine that deals with the repair or replacement of damaged or diseased cells, tissues, and organs using various strategies, including the use of stem cells, tissue engineering, gene therapy, and biomaterials. The goal of regenerative medicine is to restore normal function and structure to tissues and organs, thereby improving the patient's quality of life and potentially curing diseases that were previously considered incurable.

Regenerative medicine has shown promise in a variety of clinical applications, such as the treatment of degenerative diseases like osteoarthritis, spinal cord injuries, heart disease, diabetes, and liver failure. It also holds great potential for use in regenerative therapies for wound healing, tissue reconstruction, and cosmetic surgery.

The field of regenerative medicine is rapidly evolving, with new discoveries and advances being made regularly. As our understanding of the underlying biological mechanisms that drive tissue repair and regeneration continues to grow, so too will the potential clinical applications of this exciting and promising field.

Flow cytometry is a medical and research technique used to measure physical and chemical characteristics of cells or particles, one cell at a time, as they flow in a fluid stream through a beam of light. The properties measured include:

* Cell size (light scatter)
* Cell internal complexity (granularity, also light scatter)
* Presence or absence of specific proteins or other molecules on the cell surface or inside the cell (using fluorescent antibodies or other fluorescent probes)

The technique is widely used in cell counting, cell sorting, protein engineering, biomarker discovery and monitoring disease progression, particularly in hematology, immunology, and cancer research.

Bone Morphogenetic Protein 4 (BMP-4) is a growth factor that belongs to the transforming growth factor-beta (TGF-β) superfamily. It plays crucial roles in various biological processes, including embryonic development, cell growth, and differentiation. In the skeletal system, BMP-4 stimulates the formation of bone and cartilage by inducing the differentiation of mesenchymal stem cells into chondrocytes and osteoblasts. It also regulates the maintenance and repair of bones throughout life. An imbalance in BMP-4 signaling has been associated with several skeletal disorders, such as heterotopic ossification and osteoarthritis.

Cell separation is a process used to separate and isolate specific cell types from a heterogeneous mixture of cells. This can be accomplished through various physical or biological methods, depending on the characteristics of the cells of interest. Some common techniques for cell separation include:

1. Density gradient centrifugation: In this method, a sample containing a mixture of cells is layered onto a density gradient medium and then centrifuged. The cells are separated based on their size, density, and sedimentation rate, with denser cells settling closer to the bottom of the tube and less dense cells remaining near the top.

2. Magnetic-activated cell sorting (MACS): This technique uses magnetic beads coated with antibodies that bind to specific cell surface markers. The labeled cells are then passed through a column placed in a magnetic field, which retains the magnetically labeled cells while allowing unlabeled cells to flow through.

3. Fluorescence-activated cell sorting (FACS): In this method, cells are stained with fluorochrome-conjugated antibodies that recognize specific cell surface or intracellular markers. The stained cells are then passed through a laser beam, which excites the fluorophores and allows for the detection and sorting of individual cells based on their fluorescence profile.

4. Filtration: This simple method relies on the physical size differences between cells to separate them. Cells can be passed through filters with pore sizes that allow smaller cells to pass through while retaining larger cells.

5. Enzymatic digestion: In some cases, cells can be separated by enzymatically dissociating tissues into single-cell suspensions and then using various separation techniques to isolate specific cell types.

These methods are widely used in research and clinical settings for applications such as isolating immune cells, stem cells, or tumor cells from biological samples.

Green Fluorescent Protein (GFP) is not a medical term per se, but a scientific term used in the field of molecular biology. GFP is a protein that exhibits bright green fluorescence when exposed to light, particularly blue or ultraviolet light. It was originally discovered in the jellyfish Aequorea victoria.

In medical and biological research, scientists often use recombinant DNA technology to introduce the gene for GFP into other organisms, including bacteria, plants, and animals, including humans. This allows them to track the expression and localization of specific genes or proteins of interest in living cells, tissues, or even whole organisms.

The ability to visualize specific cellular structures or processes in real-time has proven invaluable for a wide range of research areas, from studying the development and function of organs and organ systems to understanding the mechanisms of diseases and the effects of therapeutic interventions.

Coculture techniques refer to a type of experimental setup in which two or more different types of cells or organisms are grown and studied together in a shared culture medium. This method allows researchers to examine the interactions between different cell types or species under controlled conditions, and to study how these interactions may influence various biological processes such as growth, gene expression, metabolism, and signal transduction.

Coculture techniques can be used to investigate a wide range of biological phenomena, including the effects of host-microbe interactions on human health and disease, the impact of different cell types on tissue development and homeostasis, and the role of microbial communities in shaping ecosystems. These techniques can also be used to test the efficacy and safety of new drugs or therapies by examining their effects on cells grown in coculture with other relevant cell types.

There are several different ways to establish cocultures, depending on the specific research question and experimental goals. Some common methods include:

1. Mixed cultures: In this approach, two or more cell types are simply mixed together in a culture dish or flask and allowed to grow and interact freely.
2. Cell-layer cultures: Here, one cell type is grown on a porous membrane or other support structure, while the second cell type is grown on top of it, forming a layered coculture.
3. Conditioned media cultures: In this case, one cell type is grown to confluence and its culture medium is collected and then used to grow a second cell type. This allows the second cell type to be exposed to any factors secreted by the first cell type into the medium.
4. Microfluidic cocultures: These involve growing cells in microfabricated channels or chambers, which allow for precise control over the spatial arrangement and flow of nutrients, waste products, and signaling molecules between different cell types.

Overall, coculture techniques provide a powerful tool for studying complex biological systems and gaining insights into the mechanisms that underlie various physiological and pathological processes.

Hematopoiesis is the process of forming and developing blood cells. It occurs in the bone marrow and includes the production of red blood cells (erythropoiesis), white blood cells (leukopoiesis), and platelets (thrombopoiesis). This process is regulated by various growth factors, hormones, and cytokines. Hematopoiesis begins early in fetal development and continues throughout a person's life. Disorders of hematopoiesis can result in conditions such as anemia, leukopenia, leukocytosis, thrombocytopenia, or thrombocytosis.

A biological marker, often referred to as a biomarker, is a measurable indicator that reflects the presence or severity of a disease state, or a response to a therapeutic intervention. Biomarkers can be found in various materials such as blood, tissues, or bodily fluids, and they can take many forms, including molecular, histologic, radiographic, or physiological measurements.

In the context of medical research and clinical practice, biomarkers are used for a variety of purposes, such as:

1. Diagnosis: Biomarkers can help diagnose a disease by indicating the presence or absence of a particular condition. For example, prostate-specific antigen (PSA) is a biomarker used to detect prostate cancer.
2. Monitoring: Biomarkers can be used to monitor the progression or regression of a disease over time. For instance, hemoglobin A1c (HbA1c) levels are monitored in diabetes patients to assess long-term blood glucose control.
3. Predicting: Biomarkers can help predict the likelihood of developing a particular disease or the risk of a negative outcome. For example, the presence of certain genetic mutations can indicate an increased risk for breast cancer.
4. Response to treatment: Biomarkers can be used to evaluate the effectiveness of a specific treatment by measuring changes in the biomarker levels before and after the intervention. This is particularly useful in personalized medicine, where treatments are tailored to individual patients based on their unique biomarker profiles.

It's important to note that for a biomarker to be considered clinically valid and useful, it must undergo rigorous validation through well-designed studies, including demonstrating sensitivity, specificity, reproducibility, and clinical relevance.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

Germ cells are the reproductive cells, also known as sex cells, that combine to form offspring in sexual reproduction. In females, germ cells are called ova or egg cells, and in males, they are called spermatozoa or sperm cells. These cells are unique because they carry half the genetic material necessary for creating new life. They are produced through a process called meiosis, which reduces their chromosome number by half, ensuring that when two germ cells combine during fertilization, the normal diploid number of chromosomes is restored.

Cardiac myocytes are the muscle cells that make up the heart muscle, also known as the myocardium. These specialized cells are responsible for contracting and relaxing in a coordinated manner to pump blood throughout the body. They differ from skeletal muscle cells in several ways, including their ability to generate their own electrical impulses, which allows the heart to function as an independent rhythmical pump. Cardiac myocytes contain sarcomeres, the contractile units of the muscle, and are connected to each other by intercalated discs that help coordinate contraction and ensure the synchronous beating of the heart.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

Fetal stem cells are a type of stem cell that are derived from fetal tissue, which is tissue obtained from an elective abortion or a spontaneous miscarriage. These stem cells have the ability to differentiate into various cell types, including neurons, cardiac muscle cells, and hepatocytes (liver cells). Fetal stem cells are unique in that they have a greater capacity for self-renewal and can generate a larger number of differentiated cells compared to adult stem cells. They also have the potential to be less immunogenic than other types of stem cells, making them a promising candidate for cell-based therapies and regenerative medicine. However, the use of fetal stem cells is a subject of ethical debate due to their source.

Epigenetics is the study of heritable changes in gene function that occur without a change in the underlying DNA sequence. These changes can be caused by various mechanisms such as DNA methylation, histone modification, and non-coding RNA molecules. Epigenetic changes can be influenced by various factors including age, environment, lifestyle, and disease state.

Genetic epigenesis specifically refers to the study of how genetic factors influence these epigenetic modifications. Genetic variations between individuals can lead to differences in epigenetic patterns, which in turn can contribute to phenotypic variation and susceptibility to diseases. For example, certain genetic variants may predispose an individual to develop cancer, and environmental factors such as smoking or exposure to chemicals can interact with these genetic variants to trigger epigenetic changes that promote tumor growth.

Overall, the field of genetic epigenesis aims to understand how genetic and environmental factors interact to regulate gene expression and contribute to disease susceptibility.

Embryonic development is the series of growth and developmental stages that occur during the formation and early growth of the embryo. In humans, this stage begins at fertilization (when the sperm and egg cell combine) and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (now called a zygote) divides and forms a blastocyst, which then implants into the uterus. The cells in the blastocyst begin to differentiate and form the three germ layers: the ectoderm, mesoderm, and endoderm. These germ layers will eventually give rise to all of the different tissues and organs in the body.

Embryonic development is a complex and highly regulated process that involves the coordinated interaction of genetic and environmental factors. It is characterized by rapid cell division, migration, and differentiation, as well as programmed cell death (apoptosis) and tissue remodeling. Abnormalities in embryonic development can lead to birth defects or other developmental disorders.

It's important to note that the term "embryo" is used to describe the developing organism from fertilization until the end of the 8th week of pregnancy in humans, after which it is called a fetus.

SCID mice is an acronym for Severe Combined Immunodeficiency mice. These are genetically modified mice that lack a functional immune system due to the mutation or knockout of several key genes required for immunity. This makes them ideal for studying the human immune system, infectious diseases, and cancer, as well as testing new therapies and treatments in a controlled environment without the risk of interference from the mouse's own immune system. SCID mice are often used in xenotransplantation studies, where human cells or tissues are transplanted into the mouse to study their behavior and interactions with the human immune system.

Regeneration in a medical context refers to the process of renewal, restoration, and growth that replaces damaged or missing cells, tissues, organs, or even whole limbs in some organisms. This complex biological process involves various cellular and molecular mechanisms, such as cell proliferation, differentiation, and migration, which work together to restore the structural and functional integrity of the affected area.

In human medicine, regeneration has attracted significant interest due to its potential therapeutic applications in treating various conditions, including degenerative diseases, trauma, and congenital disorders. Researchers are actively studying the underlying mechanisms of regeneration in various model organisms to develop novel strategies for promoting tissue repair and regeneration in humans.

Examples of regeneration in human medicine include liver regeneration after partial hepatectomy, where the remaining liver lobes can grow back to their original size within weeks, and skin wound healing, where keratinocytes migrate and proliferate to close the wound and restore the epidermal layer. However, the regenerative capacity of humans is limited compared to some other organisms, such as planarians and axolotls, which can regenerate entire body parts or even their central nervous system.

Activins are a type of protein that belongs to the transforming growth factor-beta (TGF-β) superfamily. They are produced and released by various cells in the body, including those in the ovaries, testes, pituitary gland, and other tissues. Activins play important roles in regulating several biological processes, such as cell growth, differentiation, and apoptosis (programmed cell death).

Activins bind to specific receptors on the surface of cells, leading to the activation of intracellular signaling pathways that control gene expression. They are particularly well-known for their role in reproductive biology, where they help regulate follicle stimulation and hormone production in the ovaries and testes. Activins also have been implicated in various disease processes, including cancer, fibrosis, and inflammation.

There are three main isoforms of activin in humans: activin A, activin B, and inhibin A. While activins and inhibins share similar structures and functions, they have opposite effects on the activity of the pituitary gland. Activins stimulate the production of follicle-stimulating hormone (FSH), while inhibins suppress it. This delicate balance between activins and inhibins helps regulate reproductive function and other physiological processes in the body.

Cell dedifferentiation is a process by which a mature, specialized cell reverts back to an earlier stage in its developmental lineage, regaining the ability to divide and differentiate into various cell types. This phenomenon is typically observed in cells that have been damaged or injured, as well as during embryonic development and certain disease states like cancer. In the context of tissue repair and regeneration, dedifferentiation allows for the generation of new cells with the potential to replace lost or damaged tissues. However, uncontrolled dedifferentiation can also contribute to tumor formation and progression.

Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.

The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.

Neoplastic stem cells, also known as cancer stem cells (CSCs), are a subpopulation of cells within a tumor that are capable of self-renewal and generating the heterogeneous lineages of cells that comprise the tumor. These cells are believed to be responsible for the initiation, maintenance, and progression of cancer, as well as its recurrence and resistance to therapy.

CSCs share some similarities with normal stem cells, such as their ability to divide asymmetrically and give rise to differentiated progeny. However, they also have distinct characteristics that distinguish them from their normal counterparts, including aberrant gene expression, altered signaling pathways, and increased resistance to apoptosis (programmed cell death).

The existence of CSCs has important implications for cancer diagnosis, treatment, and prevention. Targeting these cells specifically may be necessary to achieve durable remissions and prevent relapse, as they are thought to survive conventional therapies that target the bulk of the tumor. Further research is needed to better understand the biology of CSCs and develop effective strategies for their elimination.

Cell survival refers to the ability of a cell to continue living and functioning normally, despite being exposed to potentially harmful conditions or treatments. This can include exposure to toxins, radiation, chemotherapeutic drugs, or other stressors that can damage cells or interfere with their normal processes.

In scientific research, measures of cell survival are often used to evaluate the effectiveness of various therapies or treatments. For example, researchers may expose cells to a particular drug or treatment and then measure the percentage of cells that survive to assess its potential therapeutic value. Similarly, in toxicology studies, measures of cell survival can help to determine the safety of various chemicals or substances.

It's important to note that cell survival is not the same as cell proliferation, which refers to the ability of cells to divide and multiply. While some treatments may promote cell survival, they may also inhibit cell proliferation, making them useful for treating diseases such as cancer. Conversely, other treatments may be designed to specifically target and kill cancer cells, even if it means sacrificing some healthy cells in the process.

Karyotyping is a medical laboratory test used to study the chromosomes in a cell. It involves obtaining a sample of cells from a patient, usually from blood or bone marrow, and then staining the chromosomes so they can be easily seen under a microscope. The chromosomes are then arranged in pairs based on their size, shape, and other features to create a karyotype. This visual representation allows for the identification and analysis of any chromosomal abnormalities, such as extra or missing chromosomes, or structural changes like translocations or inversions. These abnormalities can provide important information about genetic disorders, diseases, and developmental problems.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

A plant stem is not typically defined in a medical context, but rather in the field of botany. However, I can certainly provide a general biological definition for you.

In plants, stems are organs that serve primarily as support structures, holding leaves, flowers, and fruits aloft where they can receive sunlight and exchange gases. They also act as conduits, transporting water, nutrients, and sugars made during photosynthesis between the roots and shoots of a plant.

The stem is usually composed of three main tissue systems: dermal, vascular, and ground. The dermal tissue system forms the outermost layer(s) of the stem, providing protection and sometimes participating in gas exchange. The vascular tissue system contains the xylem (which transports water and nutrients upward) and phloem (which transports sugars and other organic compounds downward). The ground tissue system, located between the dermal and vascular tissues, is responsible for food storage and support.

While not a direct medical definition, understanding the structure and function of plant stems can be relevant in fields such as nutrition, agriculture, and environmental science, which have implications for human health.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

Cloning of an organism is the process of creating a genetically identical copy of an entire living organism, including all of its DNA. This is achieved through a variety of laboratory techniques that can vary depending on the type of organism being cloned. In the case of animals, one common method is called somatic cell nuclear transfer (SCNT).

In SCNT, the nucleus of a donor animal's cell (which contains its DNA) is removed and transferred into an egg cell that has had its own nucleus removed. The egg cell is then stimulated to divide and grow, resulting in an embryo that is genetically identical to the donor animal. This embryo can be implanted into a surrogate mother, where it will continue to develop until birth.

Cloning of organisms has raised ethical concerns and debates, particularly in the case of animals, due to questions about the welfare of cloned animals and the potential implications for human cloning. However, cloning is also seen as having potential benefits, such as the ability to produce genetically identical animals for research or agricultural purposes.

It's important to note that while cloning can create genetically identical organisms, it does not necessarily mean that they will be identical in every way, as environmental factors and random genetic mutations can still result in differences between clones.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

Tissue engineering is a branch of biomedical engineering that combines the principles of engineering, materials science, and biological sciences to develop functional substitutes for damaged or diseased tissues and organs. It involves the creation of living, three-dimensional structures that can restore, maintain, or improve tissue function. This is typically accomplished through the use of cells, scaffolds (biodegradable matrices), and biologically active molecules. The goal of tissue engineering is to develop biological substitutes that can ultimately restore normal function and structure in damaged tissues or organs.

Tretinoin is a form of vitamin A that is used in the treatment of acne vulgaris, fine wrinkles, and dark spots caused by aging or sun damage. It works by increasing the turnover of skin cells, helping to unclog pores and promote the growth of new skin cells. Tretinoin is available as a cream, gel, or liquid, and is usually applied to the affected area once a day in the evening. Common side effects include redness, dryness, and peeling of the skin. It is important to avoid sunlight and use sunscreen while using tretinoin, as it can make the skin more sensitive to the sun.

DNA-binding proteins are a type of protein that have the ability to bind to DNA (deoxyribonucleic acid), the genetic material of organisms. These proteins play crucial roles in various biological processes, such as regulation of gene expression, DNA replication, repair and recombination.

The binding of DNA-binding proteins to specific DNA sequences is mediated by non-covalent interactions, including electrostatic, hydrogen bonding, and van der Waals forces. The specificity of binding is determined by the recognition of particular nucleotide sequences or structural features of the DNA molecule.

DNA-binding proteins can be classified into several categories based on their structure and function, such as transcription factors, histones, and restriction enzymes. Transcription factors are a major class of DNA-binding proteins that regulate gene expression by binding to specific DNA sequences in the promoter region of genes and recruiting other proteins to modulate transcription. Histones are DNA-binding proteins that package DNA into nucleosomes, the basic unit of chromatin structure. Restriction enzymes are DNA-binding proteins that recognize and cleave specific DNA sequences, and are widely used in molecular biology research and biotechnology applications.

In medical and embryological terms, the mesoderm is one of the three primary germ layers in the very early stages of embryonic development. It forms between the ectoderm and endoderm during gastrulation, and it gives rise to a wide variety of cell types, tissues, and organs in the developing embryo.

The mesoderm contributes to the formation of structures such as:

1. The connective tissues (including tendons, ligaments, and most of the bones)
2. Muscular system (skeletal, smooth, and cardiac muscles)
3. Circulatory system (heart, blood vessels, and blood cells)
4. Excretory system (kidneys and associated structures)
5. Reproductive system (gonads, including ovaries and testes)
6. Dermis of the skin
7. Parts of the eye and inner ear
8. Several organs in the urogenital system

Dysfunctions or abnormalities in mesoderm development can lead to various congenital disorders and birth defects, highlighting its importance during embryogenesis.

Cell-and tissue-based therapy is a type of medical treatment that involves the use of living cells or tissues to repair, replace, or regenerate damaged or diseased cells or tissues in the body. This can include the transplantation of stem cells, which are immature cells that have the ability to develop into different types of cells, as well as the use of fully differentiated cells or tissues that have specific functions in the body.

Cell-and tissue-based therapies may be used to treat a wide variety of medical conditions, including degenerative diseases, injuries, and congenital defects. Some examples of cell-and tissue-based therapies include:

* Bone marrow transplantation: This involves the transplantation of blood-forming stem cells from the bone marrow of a healthy donor to a patient in need of new blood cells due to disease or treatment with chemotherapy or radiation.
* Corneal transplantation: This involves the transplantation of healthy corneal tissue from a deceased donor to a patient with damaged or diseased corneas.
* Articular cartilage repair: This involves the use of cells or tissues to repair damaged articular cartilage, which is the smooth, white tissue that covers the ends of bones where they come together to form joints.

Cell-and tissue-based therapies are a rapidly evolving field of medicine, and researchers are continually exploring new ways to use these treatments to improve patient outcomes. However, it is important to note that cell-and tissue-based therapies also carry some risks, including the possibility of rejection or infection, and they should only be performed by qualified medical professionals in appropriate settings.

Embryonal carcinoma stem cells (ECSCs) are a type of cancer stem cell found in embryonal carcinomas, which are a rare form of germ cell tumor that primarily affect the testicles and ovaries. These stem cells are characterized by their ability to differentiate into various cell types, similar to embryonic stem cells. They are believed to play a key role in the development and progression of embryonal carcinomas, as they can self-renew and generate the heterogeneous population of cancer cells that make up the tumor.

Embryonal carcinoma stem cells have been studied extensively as a model system for understanding the biology of cancer stem cells and developing new therapies for germ cell tumors. They are known to express specific markers, such as Oct-4, Nanog, and Sox2, which are also expressed in embryonic stem cells and are involved in maintaining their pluripotency.

It is important to note that while embryonal carcinoma stem cells share some similarities with embryonic stem cells, they are distinct from them and have undergone malignant transformation, making them a target for cancer therapy.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Embryo culture techniques refer to the methods and procedures used to maintain and support the growth and development of an embryo outside of the womb, typically in a laboratory setting. These techniques are often used in the context of assisted reproductive technologies (ART), such as in vitro fertilization (IVF).

The process typically involves fertilizing an egg with sperm in a laboratory dish and then carefully monitoring and maintaining the resulting embryo in a specialized culture medium that provides the necessary nutrients, hormones, and other factors to support its development. The culture medium is usually contained within an incubator that maintains optimal temperature, humidity, and gas concentrations to mimic the environment inside the body.

Embryologists may use various embryo culture techniques depending on the stage of development and the specific needs of the embryo. For example, some techniques involve culturing the embryo in a single layer, while others may use a technique called "co-culture" that involves growing the embryo on a layer of cells to provide additional support and nutrients.

The goal of embryo culture techniques is to promote the healthy growth and development of the embryo, increasing the chances of a successful pregnancy and live birth. However, it's important to note that these techniques are not without risk, and there are potential ethical considerations surrounding the use of ART and embryo culture.

Bone marrow cells are the types of cells found within the bone marrow, which is the spongy tissue inside certain bones in the body. The main function of bone marrow is to produce blood cells. There are two types of bone marrow: red and yellow. Red bone marrow is where most blood cell production takes place, while yellow bone marrow serves as a fat storage site.

The three main types of bone marrow cells are:

1. Hematopoietic stem cells (HSCs): These are immature cells that can differentiate into any type of blood cell, including red blood cells, white blood cells, and platelets. They have the ability to self-renew, meaning they can divide and create more hematopoietic stem cells.
2. Red blood cell progenitors: These are immature cells that will develop into mature red blood cells, also known as erythrocytes. Red blood cells carry oxygen from the lungs to the body's tissues and carbon dioxide back to the lungs.
3. Myeloid and lymphoid white blood cell progenitors: These are immature cells that will develop into various types of white blood cells, which play a crucial role in the body's immune system by fighting infections and diseases. Myeloid progenitors give rise to granulocytes (neutrophils, eosinophils, and basophils), monocytes, and megakaryocytes (which eventually become platelets). Lymphoid progenitors differentiate into B cells, T cells, and natural killer (NK) cells.

Bone marrow cells are essential for maintaining a healthy blood cell count and immune system function. Abnormalities in bone marrow cells can lead to various medical conditions, such as anemia, leukopenia, leukocytosis, thrombocytopenia, or thrombocytosis, depending on the specific type of blood cell affected. Additionally, bone marrow cells are often used in transplantation procedures to treat patients with certain types of cancer, such as leukemia and lymphoma, or other hematologic disorders.

A lentivirus is a type of slow-acting retrovirus that can cause chronic diseases and cancers. The term "lentivirus" comes from the Latin word "lentus," which means slow. Lentiviruses are characterized by their ability to establish a persistent infection, during which they continuously produce new viral particles.

Lentiviruses have a complex genome that includes several accessory genes, in addition to the typical gag, pol, and env genes found in all retroviruses. These accessory genes play important roles in regulating the virus's replication cycle and evading the host's immune response.

One of the most well-known lentiviruses is the human immunodeficiency virus (HIV), which causes AIDS. Other examples include the feline immunodeficiency virus (FIV) and the simian immunodeficiency virus (SIV). Lentiviruses have also been used as vectors for gene therapy, as they can efficiently introduce new genes into both dividing and non-dividing cells.

Oligonucleotide Array Sequence Analysis is a type of microarray analysis that allows for the simultaneous measurement of the expression levels of thousands of genes in a single sample. In this technique, oligonucleotides (short DNA sequences) are attached to a solid support, such as a glass slide, in a specific pattern. These oligonucleotides are designed to be complementary to specific target mRNA sequences from the sample being analyzed.

During the analysis, labeled RNA or cDNA from the sample is hybridized to the oligonucleotide array. The level of hybridization is then measured and used to determine the relative abundance of each target sequence in the sample. This information can be used to identify differences in gene expression between samples, which can help researchers understand the underlying biological processes involved in various diseases or developmental stages.

It's important to note that this technique requires specialized equipment and bioinformatics tools for data analysis, as well as careful experimental design and validation to ensure accurate and reproducible results.

High Mobility Group Box (HMGB) proteins are a family of nuclear proteins that are highly conserved and expressed in eukaryotic cells. They play a crucial role in the regulation of gene expression, DNA repair, and maintenance of nucleosome structure. HMGB proteins contain two positively charged DNA-binding domains (HMG boxes) and a negatively charged acidic tail. These proteins can bind to DNA in a variety of ways, bending it and altering its structure, which in turn affects the binding of other proteins and the transcriptional activity of genes. HMGB proteins can also be released from cells under conditions of stress or injury, where they act as damage-associated molecular patterns (DAMPs) and contribute to the inflammatory response.

Parthenogenesis is a form of asexual reproduction in which offspring develop from unfertilized eggs or ovums. It occurs naturally in some plant and insect species, as well as a few vertebrates such as reptiles and fish. Parthenogenesis does not involve the fusion of sperm and egg cells; instead, the development of offspring is initiated by some other trigger, such as a chemical or physical stimulus. This type of reproduction results in offspring that are genetically identical to the parent organism. In humans and other mammals, parthenogenesis is not a natural occurrence and would require scientific intervention to induce.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

A transgene is a segment of DNA that has been artificially transferred from one organism to another, typically between different species, to introduce a new trait or characteristic. The term "transgene" specifically refers to the genetic material that has been transferred and has become integrated into the host organism's genome. This technology is often used in genetic engineering and biomedical research, including the development of genetically modified organisms (GMOs) for agricultural purposes or the creation of animal models for studying human diseases.

Transgenes can be created using various techniques, such as molecular cloning, where a desired gene is isolated, manipulated, and then inserted into a vector (a small DNA molecule, such as a plasmid) that can efficiently enter the host organism's cells. Once inside the cell, the transgene can integrate into the host genome, allowing for the expression of the new trait in the resulting transgenic organism.

It is important to note that while transgenes can provide valuable insights and benefits in research and agriculture, their use and release into the environment are subjects of ongoing debate due to concerns about potential ecological impacts and human health risks.

Nestin is a type of class VI intermediate filament protein that is primarily expressed in various types of undifferentiated or progenitor cells in the nervous system, including neural stem cells and progenitor cells. It is often used as a marker for these cells due to its expression during stages of active cell division and migration. Nestin is also expressed in some other tissues undergoing regeneration or injury.

SOXF transcription factors are a subgroup of the SOX (SRY-related HMG box) family of proteins, which are involved in various developmental processes. The SOXF group includes SOX7, SOX17, and SOX18, all of which contain a conserved high mobility group (HMG) box DNA-binding domain. These transcription factors play crucial roles in the development of several organ systems, including the cardiovascular system, nervous system, and urogenital system. They are involved in cell fate determination, differentiation, and morphogenesis during embryonic development and have also been implicated in various disease processes, such as cancer.

DNA methylation is a process by which methyl groups (-CH3) are added to the cytosine ring of DNA molecules, often at the 5' position of cytospine phosphate-deoxyguanosine (CpG) dinucleotides. This modification is catalyzed by DNA methyltransferase enzymes and results in the formation of 5-methylcytosine.

DNA methylation plays a crucial role in the regulation of gene expression, genomic imprinting, X chromosome inactivation, and suppression of transposable elements. Abnormal DNA methylation patterns have been associated with various diseases, including cancer, where tumor suppressor genes are often silenced by promoter methylation.

In summary, DNA methylation is a fundamental epigenetic modification that influences gene expression and genome stability, and its dysregulation has important implications for human health and disease.

Neurogenesis is the process by which new neurons (nerve cells) are generated in the brain. It occurs throughout life in certain areas of the brain, such as the hippocampus and subventricular zone, although the rate of neurogenesis decreases with age. Neurogenesis involves the proliferation, differentiation, and integration of new neurons into existing neural circuits. This process plays a crucial role in learning, memory, and recovery from brain injury or disease.

The neural plate is a structure formed during the embryonic development of vertebrates. It is a thickened plate of ectodermal cells located on the dorsal surface of the developing embryo. The neural plate gives rise to the central nervous system, including the brain and spinal cord.

The process of neural plate formation begins with the specification of ectodermal cells into neural fated cells, a process that is regulated by various signaling molecules. Once specified, these cells undergo morphological changes, resulting in the thickening of the ectoderm to form the neural plate.

The neural plate then undergoes a series of folding movements, leading to the formation of the neural tube, which eventually develops into the brain and spinal cord. The edges of the neural plate, known as the neural folds, come together and fuse, forming a closed tube. Failure of the neural folds to fuse properly can result in neural tube defects, such as spina bifida.

Overall, the neural plate is a critical structure in the development of the nervous system in vertebrates, and its formation and subsequent development are tightly regulated by various genetic and environmental factors.

Hematopoietic Stem Cell Mobilization is the process of mobilizing hematopoietic stem cells (HSCs) from the bone marrow into the peripheral blood. HSCs are immature cells that have the ability to differentiate into all types of blood cells, including red and white blood cells and platelets.

Mobilization is often achieved through the use of medications such as granulocyte-colony stimulating factor (G-CSF) or plerixafor, which stimulate the release of HSCs from the bone marrow into the peripheral blood. This allows for the collection of HSCs from the peripheral blood through a procedure called apheresis.

Mobilized HSCs can be used in stem cell transplantation procedures to reconstitute a patient's hematopoietic system after high-dose chemotherapy or radiation therapy. It is an important process in the field of regenerative medicine and has been used to treat various diseases such as leukemia, lymphoma, and sickle cell disease.

A genetic vector is a vehicle, often a plasmid or a virus, that is used to introduce foreign DNA into a host cell as part of genetic engineering or gene therapy techniques. The vector contains the desired gene or genes, along with regulatory elements such as promoters and enhancers, which are needed for the expression of the gene in the target cells.

The choice of vector depends on several factors, including the size of the DNA to be inserted, the type of cell to be targeted, and the efficiency of uptake and expression required. Commonly used vectors include plasmids, adenoviruses, retroviruses, and lentiviruses.

Plasmids are small circular DNA molecules that can replicate independently in bacteria. They are often used as cloning vectors to amplify and manipulate DNA fragments. Adenoviruses are double-stranded DNA viruses that infect a wide range of host cells, including human cells. They are commonly used as gene therapy vectors because they can efficiently transfer genes into both dividing and non-dividing cells.

Retroviruses and lentiviruses are RNA viruses that integrate their genetic material into the host cell's genome. This allows for stable expression of the transgene over time. Lentiviruses, a subclass of retroviruses, have the advantage of being able to infect non-dividing cells, making them useful for gene therapy applications in post-mitotic tissues such as neurons and muscle cells.

Overall, genetic vectors play a crucial role in modern molecular biology and medicine, enabling researchers to study gene function, develop new therapies, and modify organisms for various purposes.

Histones are highly alkaline proteins found in the chromatin of eukaryotic cells. They are rich in basic amino acid residues, such as arginine and lysine, which give them their positive charge. Histones play a crucial role in packaging DNA into a more compact structure within the nucleus by forming a complex with it called a nucleosome. Each nucleosome contains about 146 base pairs of DNA wrapped around an octamer of eight histone proteins (two each of H2A, H2B, H3, and H4). The N-terminal tails of these histones are subject to various post-translational modifications, such as methylation, acetylation, and phosphorylation, which can influence chromatin structure and gene expression. Histone variants also exist, which can contribute to the regulation of specific genes and other nuclear processes.

CD34 is a type of antigen that is found on the surface of certain cells in the human body. Specifically, CD34 antigens are present on hematopoietic stem cells, which are immature cells that can develop into different types of blood cells. These stem cells are found in the bone marrow and are responsible for producing red blood cells, white blood cells, and platelets.

CD34 antigens are a type of cell surface marker that is used in medical research and clinical settings to identify and isolate hematopoietic stem cells. They are also used in the development of stem cell therapies and transplantation procedures. CD34 antigens can be detected using various laboratory techniques, such as flow cytometry or immunohistochemistry.

It's important to note that while CD34 is a useful marker for identifying hematopoietic stem cells, it is not exclusive to these cells and can also be found on other cell types, such as endothelial cells that line blood vessels. Therefore, additional markers are often used in combination with CD34 to more specifically identify and isolate hematopoietic stem cells.

"Serum-free culture media" refers to a type of nutrient medium used in cell culture and tissue engineering that does not contain fetal bovine serum (FBS) or other animal serums. Instead, it is supplemented with defined, chemically-defined components such as hormones, growth factors, vitamins, and amino acids.

The use of serum-free media offers several advantages over traditional media formulations that contain serum. For example, it reduces the risk of contamination with adventitious agents, such as viruses and prions, that may be present in animal serums. Additionally, it allows for greater control over the culture environment, as the concentration and composition of individual components can be carefully regulated. This is particularly important in applications where precise control over cell behavior is required, such as in the production of therapeutic proteins or in stem cell research.

However, serum-free media may not be suitable for all cell types, as some cells require the complex mixture of growth factors and other components found in animal serums to survive and proliferate. Therefore, it is important to carefully evaluate the needs of each specific cell type when selecting a culture medium.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.

A Blastocyst Inner Cell Mass (ICM) is a group of cells within a blastocyst, which is an early-stage preimplantation embryo that develops in mammals. The blastocyst consists of two main components: the trophectoderm, which forms the outer layer and eventually gives rise to the placenta, and the inner cell mass (ICM), which is a cluster of cells located inside the blastocyst.

The ICM is composed of pluripotent cells that have the ability to differentiate into any of the three primary germ layers: ectoderm, mesoderm, or endoderm. These cells will eventually give rise to the fetus and some extraembryonic structures such as the yolk sac and allantois.

The ICM is an essential part of the blastocyst, and its development and quality are critical factors in the success of assisted reproductive technologies (ART) like in vitro fertilization (IVF). The assessment of the ICM's morphology and cell count can help embryologists evaluate the potential of an embryo to develop into a viable pregnancy.

Cell transplantation is the process of transferring living cells from one part of the body to another or from one individual to another. In medicine, cell transplantation is often used as a treatment for various diseases and conditions, including neurodegenerative disorders, diabetes, and certain types of cancer. The goal of cell transplantation is to replace damaged or dysfunctional cells with healthy ones, thereby restoring normal function to the affected area.

In the context of medical research, cell transplantation may involve the use of stem cells, which are immature cells that have the ability to develop into many different types of specialized cells. Stem cell transplantation has shown promise in the treatment of a variety of conditions, including spinal cord injuries, stroke, and heart disease.

It is important to note that cell transplantation carries certain risks, such as immune rejection and infection. As such, it is typically reserved for cases where other treatments have failed or are unlikely to be effective.

CD15 is a type of antigen that is found on the surface of certain types of white blood cells called neutrophils and monocytes. It is also expressed on some types of cancer cells, including myeloid leukemia cells and some lymphomas. CD15 antigens are part of a group of molecules known as carbohydrate antigens because they contain sugar-like substances called carbohydrates.

CD15 antigens play a role in the immune system's response to infection and disease. They can be recognized by certain types of immune cells, such as natural killer (NK) cells and cytotoxic T cells, which can then target and destroy cells that express CD15 antigens. In cancer, the presence of CD15 antigens on the surface of cancer cells can make them more visible to the immune system, potentially triggering an immune response against the cancer.

CD15 antigens are also used as a marker in laboratory tests to help identify and classify different types of white blood cells and cancer cells. For example, CD15 staining is often used in the diagnosis of acute myeloid leukemia (AML) to distinguish it from other types of leukemia.

Cell shape refers to the physical form or configuration of a cell, which is determined by the cytoskeleton (the internal framework of the cell) and the extracellular matrix (the external environment surrounding the cell). The shape of a cell can vary widely depending on its type and function. For example, some cells are spherical, such as red blood cells, while others are elongated or irregularly shaped. Changes in cell shape can be indicative of various physiological or pathological processes, including development, differentiation, migration, and disease.

A Colony-Forming Units (CFU) assay is a type of laboratory test used to measure the number of viable, or living, cells in a sample. It is commonly used to enumerate bacteria, yeast, and other microorganisms. The test involves placing a known volume of the sample onto a nutrient-agar plate, which provides a solid growth surface for the cells. The plate is then incubated under conditions that allow the cells to grow and form colonies. Each colony that forms on the plate represents a single viable cell from the original sample. By counting the number of colonies and multiplying by the known volume of the sample, the total number of viable cells in the sample can be calculated. This information is useful in a variety of applications, including monitoring microbial populations, assessing the effectiveness of disinfection procedures, and studying microbial growth and survival.

A nodal protein, in the context of molecular biology and genetics, refers to a protein that plays a role in signal transmission within a cell at a node or junction point of a signaling pathway. These proteins are often involved in regulatory processes, such as activating or inhibiting downstream effectors in response to specific signals received by the cell. Nodal proteins can be activated or deactivated through various mechanisms, including phosphorylation, ubiquitination, and interactions with other signaling molecules.

In a more specific context, nodal proteins are also known as nodal factors, which are members of the transforming growth factor-beta (TGF-β) superfamily of signaling molecules that play critical roles in embryonic development and tissue homeostasis. Nodal is a secreted protein that acts as a morphogen, inducing different cellular responses depending on its concentration gradient. It is involved in establishing left-right asymmetry during embryonic development and regulates various processes such as cell proliferation, differentiation, and apoptosis.

In summary, nodal proteins can refer to any protein that functions at a node or junction point of a signaling pathway, but they are also specifically known as nodal factors, which are TGF-β superfamily members involved in embryonic development and tissue homeostasis.

Bone Morphogenetic Proteins (BMPs) are a group of growth factors that play crucial roles in the development, growth, and repair of bones and other tissues. They belong to the Transforming Growth Factor-β (TGF-β) superfamily and were first discovered when researchers found that certain proteins extracted from demineralized bone matrix had the ability to induce new bone formation.

BMPs stimulate the differentiation of mesenchymal stem cells into osteoblasts, which are the cells responsible for bone formation. They also promote the recruitment and proliferation of these cells, enhancing the overall process of bone regeneration. In addition to their role in bone biology, BMPs have been implicated in various other biological processes, including embryonic development, wound healing, and the regulation of fat metabolism.

There are several types of BMPs (BMP-2, BMP-4, BMP-7, etc.) that exhibit distinct functions and expression patterns. Due to their ability to stimulate bone formation, recombinant human BMPs have been used in clinical applications, such as spinal fusion surgery and non-healing fracture treatment. However, the use of BMPs in medicine has been associated with certain risks and complications, including uncontrolled bone growth, inflammation, and cancer development, which necessitates further research to optimize their therapeutic potential.

Conditioned culture media refers to a type of growth medium that has been previously used to culture and maintain the cells of an organism. The conditioned media contains factors secreted by those cells, such as hormones, nutrients, and signaling molecules, which can affect the behavior and growth of other cells that are introduced into the media later on.

When the conditioned media is used for culturing a new set of cells, it can provide a more physiologically relevant environment than traditional culture media, as it contains factors that are specific to the original cell type. This can be particularly useful in studies that aim to understand cell-cell interactions and communication, or to mimic the natural microenvironment of cells in the body.

It's important to note that conditioned media should be handled carefully and used promptly after preparation, as the factors it contains can degrade over time and affect the quality of the results.

Wnt proteins are a family of secreted signaling molecules that play crucial roles in the regulation of fundamental biological processes, including cell proliferation, differentiation, migration, and survival. They were first discovered in 1982 through genetic studies in Drosophila melanogaster (fruit flies) and have since been found to be highly conserved across various species, from invertebrates to humans.

Wnt proteins exert their effects by binding to specific receptors on the target cell surface, leading to the activation of several intracellular signaling pathways:

1. Canonical Wnt/β-catenin pathway: In the absence of Wnt ligands, β-catenin is continuously degraded by a destruction complex consisting of Axin, APC (Adenomatous polyposis coli), and GSK3β (Glycogen synthase kinase 3 beta). When Wnt proteins bind to their receptors Frizzled and LRP5/6, the formation of a "signalosome" complex leads to the inhibition of the destruction complex, allowing β-catenin to accumulate in the cytoplasm and translocate into the nucleus. Here, it interacts with TCF/LEF (T-cell factor/lymphoid enhancer-binding factor) transcription factors to regulate the expression of target genes involved in cell proliferation, differentiation, and survival.
2. Non-canonical Wnt pathways: These include the Wnt/Ca^2+^ pathway and the planar cell polarity (PCP) pathway. In the Wnt/Ca^2+^ pathway, Wnt ligands bind to Frizzled receptors and activate heterotrimeric G proteins, leading to an increase in intracellular Ca^2+^ levels and activation of downstream targets such as protein kinase C (PKC) and calcium/calmodulin-dependent protein kinase II (CAMKII). These signaling events ultimately regulate cell movement, adhesion, and gene expression. In the PCP pathway, Wnt ligands bind to Frizzled receptors and coreceptor complexes containing Ror2 or Ryk, leading to activation of small GTPases such as RhoA and Rac1, which control cytoskeletal organization and cell polarity.

Dysregulation of Wnt signaling has been implicated in various human diseases, including cancer, developmental disorders, and degenerative conditions. In cancer, aberrant activation of the canonical Wnt/β-catenin pathway contributes to tumor initiation, progression, and metastasis by promoting cell proliferation, survival, and epithelial-mesenchymal transition (EMT). Inhibitors targeting different components of the Wnt signaling pathway are currently being developed as potential therapeutic strategies for cancer treatment.

MicroRNAs (miRNAs) are a class of small non-coding RNAs, typically consisting of around 20-24 nucleotides, that play crucial roles in post-transcriptional regulation of gene expression. They primarily bind to the 3' untranslated region (3' UTR) of target messenger RNAs (mRNAs), leading to mRNA degradation or translational repression. MicroRNAs are involved in various biological processes, including development, differentiation, proliferation, and apoptosis, and have been implicated in numerous diseases, such as cancers and neurological disorders. They can be found in various organisms, from plants to animals, and are often conserved across species. MicroRNAs are usually transcribed from DNA sequences located in introns or exons of protein-coding genes or in intergenic regions. After transcription, they undergo a series of processing steps, including cleavage by ribonucleases Drosha and Dicer, to generate mature miRNA molecules capable of binding to their target mRNAs.

Gene knockdown techniques are methods used to reduce the expression or function of specific genes in order to study their role in biological processes. These techniques typically involve the use of small RNA molecules, such as siRNAs (small interfering RNAs) or shRNAs (short hairpin RNAs), which bind to and promote the degradation of complementary mRNA transcripts. This results in a decrease in the production of the protein encoded by the targeted gene.

Gene knockdown techniques are often used as an alternative to traditional gene knockout methods, which involve completely removing or disrupting the function of a gene. Knockdown techniques allow for more subtle and reversible manipulation of gene expression, making them useful for studying genes that are essential for cell survival or have redundant functions.

These techniques are widely used in molecular biology research to investigate gene function, genetic interactions, and disease mechanisms. However, it is important to note that gene knockdown can have off-target effects and may not completely eliminate the expression of the targeted gene, so results should be interpreted with caution.

Fetal proteins are a type of proteins that are produced by the fetus during pregnancy and can be detected in various biological samples, such as amniotic fluid or maternal blood. These proteins can provide valuable information about the health and development of the fetus. One commonly studied fetal protein is human chorionic gonadotropin (hCG), which is produced by the placenta and can be used as a marker for pregnancy and to detect potential complications, such as Down syndrome or spinal cord defects. Other examples of fetal proteins include alpha-fetoprotein (AFP) and human placental lactogen (hPL).

Kruppel-like transcription factors (KLFs) are a family of transcription factors that are characterized by their highly conserved DNA-binding domain, known as the Kruppel-like zinc finger domain. This domain consists of approximately 30 amino acids and is responsible for binding to specific DNA sequences, thereby regulating gene expression.

KLFs play important roles in various biological processes, including cell proliferation, differentiation, apoptosis, and inflammation. They are involved in the development and function of many tissues and organs, such as the hematopoietic system, cardiovascular system, nervous system, and gastrointestinal tract.

There are 17 known members of the KLF family in humans, each with distinct functions and expression patterns. Some KLFs act as transcriptional activators, while others function as repressors. Dysregulation of KLFs has been implicated in various diseases, including cancer, cardiovascular disease, and diabetes.

Overall, Kruppel-like transcription factors are crucial regulators of gene expression that play important roles in normal development and physiology, as well as in the pathogenesis of various diseases.

I could not find a medical definition for "Research Embryo Creation" as such, but I can provide some context. In the field of reproductive medicine and stem cell research, the creation of embryos specifically for research purposes is a controversial topic. These research embryos are typically created using in vitro fertilization (IVF) techniques, where eggs are fertilized with sperm in a laboratory dish. The resulting embryos may then be used for various research endeavors, such as studying early human development, investigating genetic disorders, or developing new treatments for infertility and diseases. It's important to note that the creation and use of research embryos are subject to ethical guidelines and legal regulations, which vary by country and jurisdiction.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Repressor proteins are a type of regulatory protein in molecular biology that suppress the transcription of specific genes into messenger RNA (mRNA) by binding to DNA. They function as part of gene regulation processes, often working in conjunction with an operator region and a promoter region within the DNA molecule. Repressor proteins can be activated or deactivated by various signals, allowing for precise control over gene expression in response to changing cellular conditions.

There are two main types of repressor proteins:

1. DNA-binding repressors: These directly bind to specific DNA sequences (operator regions) near the target gene and prevent RNA polymerase from transcribing the gene into mRNA.
2. Allosteric repressors: These bind to effector molecules, which then cause a conformational change in the repressor protein, enabling it to bind to DNA and inhibit transcription.

Repressor proteins play crucial roles in various biological processes, such as development, metabolism, and stress response, by controlling gene expression patterns in cells.

RNA interference (RNAi) is a biological process in which RNA molecules inhibit the expression of specific genes. This process is mediated by small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), that bind to complementary sequences on messenger RNA (mRNA) molecules, leading to their degradation or translation inhibition.

RNAi plays a crucial role in regulating gene expression and defending against foreign genetic elements, such as viruses and transposons. It has also emerged as an important tool for studying gene function and developing therapeutic strategies for various diseases, including cancer and viral infections.

A "reporter gene" is a type of gene that is linked to a gene of interest in order to make the expression or activity of that gene detectable. The reporter gene encodes for a protein that can be easily measured and serves as an indicator of the presence and activity of the gene of interest. Commonly used reporter genes include those that encode for fluorescent proteins, enzymes that catalyze colorimetric reactions, or proteins that bind to specific molecules.

In the context of genetics and genomics research, a reporter gene is often used in studies involving gene expression, regulation, and function. By introducing the reporter gene into an organism or cell, researchers can monitor the activity of the gene of interest in real-time or after various experimental treatments. The information obtained from these studies can help elucidate the role of specific genes in biological processes and diseases, providing valuable insights for basic research and therapeutic development.

Nuclear transfer techniques are scientific procedures that involve the transfer of the nucleus of a cell, containing its genetic material, from one cell to another. The most well-known type of nuclear transfer is somatic cell nuclear transfer (SCNT), which is used in therapeutic cloning and reproductive cloning.

In SCNT, the nucleus of a somatic cell (a body cell, not an egg or sperm cell) is transferred into an enucleated egg cell (an egg cell from which the nucleus has been removed). The egg cell with the new nucleus is then stimulated to divide and grow, creating an embryo that is genetically identical to the donor of the somatic cell.

Nuclear transfer techniques have various potential applications in medicine, including the creation of patient-specific stem cells for use in regenerative medicine, drug development and testing, and the study of genetic diseases. However, these procedures are also associated with ethical concerns, particularly in relation to reproductive cloning and the creation of human embryos for research purposes.

GATA6 (GATA binding protein 6) is a transcription factor that belongs to the GATA family, which are characterized by their ability to bind to the DNA sequence (A/T)GATA(A/G). GATA6 plays crucial roles in the development and function of various tissues, particularly in the digestive system.

As a transcription factor, GATA6 regulates gene expression by binding to specific DNA sequences in the promoter or enhancer regions of target genes. This binding either activates or represses the transcription of these genes, thereby controlling cellular processes such as proliferation, differentiation, and survival.

In the context of the digestive system, GATA6 is essential for the development of the pancreas and small intestine. It promotes the differentiation of pancreatic progenitor cells into exocrine cells (such as acinar and ductal cells) and inhibits their differentiation into endocrine cells (such as β-cells). In the small intestine, GATA6 is involved in maintaining the identity and function of Paneth cells, which are specialized epithelial cells that play a role in innate immunity.

Mutations in the GATA6 gene have been associated with various human diseases, including pancreatic agenesis or hypoplasia, small intestinal atresia, and congenital diaphragmatic hernia. Additionally, altered GATA6 expression has been implicated in several types of cancer, such as pancreatic ductal adenocarcinoma and colorectal cancer.

Cell division is the process by which a single eukaryotic cell (a cell with a true nucleus) divides into two identical daughter cells. This complex process involves several stages, including replication of DNA, separation of chromosomes, and division of the cytoplasm. There are two main types of cell division: mitosis and meiosis.

Mitosis is the type of cell division that results in two genetically identical daughter cells. It is a fundamental process for growth, development, and tissue repair in multicellular organisms. The stages of mitosis include prophase, prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis, which divides the cytoplasm.

Meiosis, on the other hand, is a type of cell division that occurs in the gonads (ovaries and testes) during the production of gametes (sex cells). Meiosis results in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction and genetic diversity. The stages of meiosis include meiosis I and meiosis II, which are further divided into prophase, prometaphase, metaphase, anaphase, and telophase.

In summary, cell division is the process by which a single cell divides into two daughter cells, either through mitosis or meiosis. This process is critical for growth, development, tissue repair, and sexual reproduction in multicellular organisms.

Teratocarcinoma is a rare type of cancer that contains both malignant germ cells (cells that give rise to sperm or eggs) and various types of benign, or noncancerous, tissue such as muscle, bone, and nerve tissue. It most commonly occurs in the ovaries or testicles but can also develop in other areas of the body, such as the mediastinum (the area between the lungs), retroperitoneum (the area behind the abdominal lining), and pineal gland (a small endocrine gland in the brain).

Teratocarcinomas are aggressive tumors that can spread quickly to other parts of the body if not treated promptly. They typically affect young adults, with a median age at diagnosis of around 20 years old. Treatment usually involves surgical removal of the tumor, followed by chemotherapy and/or radiation therapy to kill any remaining cancer cells.

It's important to note that Teratocarcinoma is different from Teratoma which is a type of germ cell tumor that can contain various types of tissue but it does not have malignant component.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

Polycomb-group proteins (PcG proteins) are a set of conserved epigenetic regulators that play crucial roles in the development and maintenance of multicellular organisms. They were initially identified in Drosophila melanogaster as factors required for maintaining the repressed state of homeotic genes, which are important for proper body segment identity and pattern formation.

PcG proteins function as part of large multi-protein complexes, called Polycomb Repressive Complexes (PRCs), that can be divided into two main types: PRC1 and PRC2. These complexes mediate the trimethylation of histone H3 lysine 27 (H3K27me3), a chromatin modification associated with transcriptionally repressed genes.

PRC2, which contains the core proteins EZH1 or EZH2, SUZ12, and EED, is responsible for depositing H3K27me3 marks. PRC1, on the other hand, recognizes and binds to these H3K27me3 marks through its chromodomain-containing subunit CBX. PRC1 then ubiquitinates histone H2A at lysine 119 (H2AK119ub), further reinforcing the repressed state of target genes.

PcG proteins are essential for normal development, as they help maintain cell fate decisions and prevent the inappropriate expression of genes that could lead to tumorigenesis or other developmental abnormalities. Dysregulation of PcG protein function has been implicated in various human cancers, making them attractive targets for therapeutic intervention.

Basic Helix-Loop-Helix (bHLH) transcription factors are a type of proteins that regulate gene expression through binding to specific DNA sequences. They play crucial roles in various biological processes, including cell growth, differentiation, and apoptosis. The bHLH domain is composed of two amphipathic α-helices separated by a loop region. This structure allows the formation of homodimers or heterodimers, which then bind to the E-box DNA motif (5'-CANNTG-3') to regulate transcription.

The bHLH family can be further divided into several subfamilies based on their sequence similarities and functional characteristics. Some members of this family are involved in the development and function of the nervous system, while others play critical roles in the development of muscle and bone. Dysregulation of bHLH transcription factors has been implicated in various human diseases, including cancer and neurodevelopmental disorders.

Ectoderm is the outermost of the three primary germ layers in a developing embryo, along with the endoderm and mesoderm. The ectoderm gives rise to the outer covering of the body, including the skin, hair, nails, glands, and the nervous system, which includes the brain, spinal cord, and peripheral nerves. It also forms the lining of the mouth, anus, nose, and ears. Essentially, the ectoderm is responsible for producing all the epidermal structures and the neural crest cells that contribute to various derivatives such as melanocytes, adrenal medulla, smooth muscle, and peripheral nervous system components.

X chromosome inactivation (XCI) is a process that occurs in females of mammalian species, including humans, to compensate for the difference in gene dosage between the sexes. Females have two X chromosomes, while males have one X and one Y chromosome. To prevent females from having twice as many X-linked genes expressed as males, one of the two X chromosomes in each female cell is randomly inactivated during early embryonic development.

XCI results in the formation of a condensed and transcriptionally inactive structure called a Barr body, which can be observed in the nucleus of female cells. This process ensures that females express similar levels of X-linked genes as males, maintaining a balanced gene dosage. The choice of which X chromosome is inactivated (maternal or paternal) is random and occurs independently in each cell, leading to a mosaic expression pattern of X-linked genes in different cells and tissues of the female body.

Spermatogonia are a type of diploid germ cells found in the seminiferous tubules of the testis. They are the stem cells responsible for sperm production (spermatogenesis) in males. There are two types of spermatogonia: A-dark (Ad) and A-pale (Ap). The Ad spermatogonia function as reserve stem cells, while the Ap spermatogonia serve as the progenitor cells that divide to produce type B spermatogonia. Type B spermatogonia then differentiate into primary spermatocytes, which undergo meiosis to form haploid spermatozoa.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Homologous transplantation is a type of transplant surgery where organs or tissues are transferred between two genetically non-identical individuals of the same species. The term "homologous" refers to the similarity in structure and function of the donated organ or tissue to the recipient's own organ or tissue.

For example, a heart transplant from one human to another is an example of homologous transplantation because both organs are hearts and perform the same function. Similarly, a liver transplant, kidney transplant, lung transplant, and other types of organ transplants between individuals of the same species are also considered homologous transplantations.

Homologous transplantation is in contrast to heterologous or xenogeneic transplantation, where organs or tissues are transferred from one species to another, such as a pig heart transplanted into a human. Homologous transplantation is more commonly performed than heterologous transplantation due to the increased risk of rejection and other complications associated with xenogeneic transplants.

Embryonic and fetal development is the process of growth and development that occurs from fertilization of the egg (conception) to birth. The terms "embryo" and "fetus" are used to describe different stages of this development:

* Embryonic development: This stage begins at fertilization and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (zygote) divides and forms a blastocyst, which implants in the uterus and begins to develop into a complex structure called an embryo. The embryo consists of three layers of cells that will eventually form all of the organs and tissues of the body. During this stage, the basic structures of the body, including the nervous system, heart, and gastrointestinal tract, begin to form.
* Fetal development: This stage begins at the end of the 8th week of pregnancy and continues until birth. During this time, the embryo is called a fetus, and it grows and develops rapidly. The organs and tissues that were formed during the embryonic stage continue to mature and become more complex. The fetus also begins to move and kick, and it can hear and respond to sounds from outside the womb.

Overall, embryonic and fetal development is a complex and highly regulated process that involves the coordinated growth and differentiation of cells and tissues. It is a critical period of development that lays the foundation for the health and well-being of the individual throughout their life.

Chromatin is the complex of DNA, RNA, and proteins that make up the chromosomes in the nucleus of a cell. It is responsible for packaging the long DNA molecules into a more compact form that fits within the nucleus. Chromatin is made up of repeating units called nucleosomes, which consist of a histone protein octamer wrapped tightly by DNA. The structure of chromatin can be altered through chemical modifications to the histone proteins and DNA, which can influence gene expression and other cellular processes.

'Cellular spheroids' refer to three-dimensional (3D) aggregates of cells that come together to form spherical structures. These spheroids can be formed by various cell types, including cancer cells, stem cells, and primary cells, and they are often used as models to study cell-cell interactions, cell signaling, drug development, and tumor biology in a more physiologically relevant context compared to traditional two-dimensional (2D) cell cultures.

Cellular spheroids can form spontaneously under certain conditions or be induced through various methods such as hanging drop, spinner flask, or microfluidic devices. The formation of spheroids allows cells to interact with each other and the extracellular matrix in a more natural way, leading to the creation of complex structures that mimic the organization and behavior of tissues in vivo.

Studying cellular spheroids has several advantages over traditional 2D cultures, including better preservation of cell-cell interactions, improved modeling of drug penetration and resistance, and enhanced ability to recapitulate the complexity of tumor microenvironments. As a result, cellular spheroids have become an important tool in various areas of biomedical research, including cancer biology, tissue engineering, and regenerative medicine.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

Developmental genes are a set of genes that play crucial roles during the development of an organism, from fertilization to adult form. These genes are responsible for controlling fundamental processes such as cell growth, differentiation, and programmed cell death (apoptosis), which ultimately lead to the formation of various tissues, organs, and body structures. They often encode transcription factors and signaling molecules that regulate complex gene networks and cascades. Some well-known developmental genes are involved in pattern formation, segmentation, and morphogenesis, ensuring the proper spatial organization and function of different parts of the organism. Examples include Hox genes, Wnt genes, and TGF-β genes. Mutations in developmental genes can result in various developmental disorders and congenital abnormalities.

Chromatin Immunoprecipitation (ChIP) is a molecular biology technique used to analyze the interaction between proteins and DNA in the cell. It is a powerful tool for studying protein-DNA binding, such as transcription factor binding to specific DNA sequences, histone modification, and chromatin structure.

In ChIP assays, cells are first crosslinked with formaldehyde to preserve protein-DNA interactions. The chromatin is then fragmented into small pieces using sonication or other methods. Specific antibodies against the protein of interest are added to precipitate the protein-DNA complexes. After reversing the crosslinking, the DNA associated with the protein is purified and analyzed using PCR, sequencing, or microarray technologies.

ChIP assays can provide valuable information about the regulation of gene expression, epigenetic modifications, and chromatin structure in various biological processes and diseases, including cancer, development, and differentiation.

Autologous transplantation is a medical procedure where cells, tissues, or organs are removed from a person, stored and then returned back to the same individual at a later time. This is different from allogeneic transplantation where the tissue or organ is obtained from another donor. The term "autologous" is derived from the Greek words "auto" meaning self and "logos" meaning study.

In autologous transplantation, the patient's own cells or tissues are used to replace or repair damaged or diseased ones. This reduces the risk of rejection and eliminates the need for immunosuppressive drugs, which are required in allogeneic transplants to prevent the body from attacking the foreign tissue.

Examples of autologous transplantation include:

* Autologous bone marrow or stem cell transplantation, where stem cells are removed from the patient's blood or bone marrow, stored and then reinfused back into the same individual after high-dose chemotherapy or radiation therapy to treat cancer.
* Autologous skin grafting, where a piece of skin is taken from one part of the body and transplanted to another area on the same person.
* Autologous chondrocyte implantation, where cartilage cells are harvested from the patient's own knee, cultured in a laboratory and then implanted back into the knee to repair damaged cartilage.

Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria that can be recognized by the immune system and provoke an immune response. In the context of differentiation, antigens refer to specific markers that identify the developmental stage or lineage of a cell.

Differentiation antigens are proteins or carbohydrates expressed on the surface of cells during various stages of differentiation, which can be used to distinguish between cells at different maturation stages or of different cell types. These antigens play an essential role in the immune system's ability to recognize and respond to abnormal or infected cells while sparing healthy cells.

Examples of differentiation antigens include:

1. CD (cluster of differentiation) molecules: A group of membrane proteins used to identify and define various cell types, such as T cells, B cells, natural killer cells, monocytes, and granulocytes.
2. Lineage-specific antigens: Antigens that are specific to certain cell lineages, such as CD3 for T cells or CD19 for B cells.
3. Maturation markers: Antigens that indicate the maturation stage of a cell, like CD34 and CD38 on hematopoietic stem cells.

Understanding differentiation antigens is crucial in immunology, cancer research, transplantation medicine, and vaccine development.

Untranslated regions (UTRs) of RNA are the non-coding sequences that are present in mRNA (messenger RNA) molecules, which are located at both the 5' end (5' UTR) and the 3' end (3' UTR) of the mRNA, outside of the coding sequence (CDS). These regions do not get translated into proteins. They contain regulatory elements that play a role in the regulation of gene expression by affecting the stability, localization, and translation efficiency of the mRNA molecule. The 5' UTR typically contains the Shine-Dalgarno sequence in prokaryotes or the Kozak consensus sequence in eukaryotes, which are important for the initiation of translation. The 3' UTR often contains regulatory elements such as AU-rich elements (AREs) and microRNA (miRNA) binding sites that can affect mRNA stability and translation.

Apoptosis is a programmed and controlled cell death process that occurs in multicellular organisms. It is a natural process that helps maintain tissue homeostasis by eliminating damaged, infected, or unwanted cells. During apoptosis, the cell undergoes a series of morphological changes, including cell shrinkage, chromatin condensation, and fragmentation into membrane-bound vesicles called apoptotic bodies. These bodies are then recognized and engulfed by neighboring cells or phagocytic cells, preventing an inflammatory response. Apoptosis is regulated by a complex network of intracellular signaling pathways that involve proteins such as caspases, Bcl-2 family members, and inhibitors of apoptosis (IAPs).

Nerve tissue proteins are specialized proteins found in the nervous system that provide structural and functional support to nerve cells, also known as neurons. These proteins include:

1. Neurofilaments: These are type IV intermediate filaments that provide structural support to neurons and help maintain their shape and size. They are composed of three subunits - NFL (light), NFM (medium), and NFH (heavy).

2. Neuronal Cytoskeletal Proteins: These include tubulins, actins, and spectrins that provide structural support to the neuronal cytoskeleton and help maintain its integrity.

3. Neurotransmitter Receptors: These are specialized proteins located on the postsynaptic membrane of neurons that bind neurotransmitters released by presynaptic neurons, triggering a response in the target cell.

4. Ion Channels: These are transmembrane proteins that regulate the flow of ions across the neuronal membrane and play a crucial role in generating and transmitting electrical signals in neurons.

5. Signaling Proteins: These include enzymes, receptors, and adaptor proteins that mediate intracellular signaling pathways involved in neuronal development, differentiation, survival, and death.

6. Adhesion Proteins: These are cell surface proteins that mediate cell-cell and cell-matrix interactions, playing a crucial role in the formation and maintenance of neural circuits.

7. Extracellular Matrix Proteins: These include proteoglycans, laminins, and collagens that provide structural support to nerve tissue and regulate neuronal migration, differentiation, and survival.

Peripheral Blood Stem Cell Transplantation (PBSCT) is a medical procedure that involves the transplantation of stem cells, which are immature cells found in the bone marrow that can develop into different types of blood cells. In PBSCT, these stem cells are collected from the peripheral blood instead of directly from the bone marrow.

The process begins with mobilization, where a growth factor medication is given to the donor to stimulate the release of stem cells from the bone marrow into the peripheral blood. After several days, the donor's blood is then removed through a procedure called apheresis, where the stem cells are separated and collected while the remaining blood components are returned to the donor.

The collected stem cells are then infused into the recipient's bloodstream, where they migrate to the bone marrow and begin to repopulate, leading to the production of new blood cells. This procedure is often used as a treatment for various malignant and non-malignant disorders, such as leukemia, lymphoma, multiple myeloma, and aplastic anemia.

PBSCT offers several advantages over traditional bone marrow transplantation, including faster engraftment, lower risk of graft failure, and reduced procedure-related morbidity. However, it also has its own set of challenges, such as the potential for increased incidence of chronic graft-versus-host disease (GVHD) and the need for more stringent HLA matching between donor and recipient.

The cell cycle is a series of events that take place in a cell leading to its division and duplication. It consists of four main phases: G1 phase, S phase, G2 phase, and M phase.

During the G1 phase, the cell grows in size and synthesizes mRNA and proteins in preparation for DNA replication. In the S phase, the cell's DNA is copied, resulting in two complete sets of chromosomes. During the G2 phase, the cell continues to grow and produces more proteins and organelles necessary for cell division.

The M phase is the final stage of the cell cycle and consists of mitosis (nuclear division) and cytokinesis (cytoplasmic division). Mitosis results in two genetically identical daughter nuclei, while cytokinesis divides the cytoplasm and creates two separate daughter cells.

The cell cycle is regulated by various checkpoints that ensure the proper completion of each phase before progressing to the next. These checkpoints help prevent errors in DNA replication and division, which can lead to mutations and cancer.

The Wnt signaling pathway is a complex cell communication system that plays a critical role in embryonic development, tissue regeneration, and cancer. It is named after the Wingless (Wg) gene in Drosophila melanogaster and the Int-1 gene in mice, both of which were found to be involved in this pathway.

In essence, the Wnt signaling pathway involves the binding of Wnt proteins to Frizzled receptors on the cell surface, leading to the activation of intracellular signaling cascades. There are three main branches of the Wnt signaling pathway: the canonical (or Wnt/β-catenin) pathway, the noncanonical planar cell polarity (PCP) pathway, and the noncanonical Wnt/calcium pathway.

The canonical Wnt/β-catenin pathway is the most well-studied branch. In the absence of Wnt signaling, cytoplasmic β-catenin is constantly phosphorylated by a destruction complex consisting of Axin, APC, GSK3β, and CK1, leading to its ubiquitination and degradation in the proteasome. When Wnt ligands bind to Frizzled receptors and their coreceptor LRP5/6, Dishevelled is recruited and inhibits the destruction complex, allowing β-catenin to accumulate in the cytoplasm and translocate into the nucleus. In the nucleus, β-catenin interacts with TCF/LEF transcription factors to regulate the expression of target genes involved in cell proliferation, differentiation, and survival.

Dysregulation of the Wnt signaling pathway has been implicated in various human diseases, including cancer, developmental disorders, and degenerative conditions. For example, mutations in components of the canonical Wnt/β-catenin pathway can lead to the accumulation of β-catenin and subsequent activation of oncogenic target genes, contributing to tumorigenesis in various types of cancer.

Wnt3A is a type of Wnt protein, which is a secreted signaling molecule that plays crucial roles in the regulation of cell-to-cell communication during embryonic development and tissue homeostasis in adults. Specifically, Wnt3A is a member of the Wnt family that binds to Frizzled receptors and activates the canonical Wnt/β-catenin signaling pathway.

In this pathway, Wnt3A binding to its receptor leads to the inhibition of the β-catenin destruction complex, resulting in the stabilization and accumulation of β-catenin in the cytoplasm. β-catenin then translocates to the nucleus, where it interacts with TCF/LEF transcription factors to regulate the expression of target genes involved in cell proliferation, differentiation, and survival.

Wnt3A has been extensively studied in various biological contexts, including developmental biology, cancer research, and stem cell biology. In particular, Wnt3A has been shown to play important roles in the regulation of embryonic axis formation, neural crest development, and adult tissue regeneration. Dysregulation of Wnt/β-catenin signaling, including aberrant activation by Wnt3A, has been implicated in various human diseases, such as cancer, degenerative disorders, and fibrotic diseases.

Embryonal carcinoma is a rare and aggressive type of cancer that arises from primitive germ cells. It typically occurs in the gonads (ovaries or testicles), but can also occur in other areas of the body such as the mediastinum, retroperitoneum, or sacrococcygeal region.

Embryonal carcinoma is called "embryonal" because the cancerous cells resemble those found in an embryo during early stages of development. These cells are capable of differentiating into various cell types, which can lead to a mix of cell types within the tumor.

Embryonal carcinoma is a highly malignant tumor that tends to grow and spread quickly. It can metastasize to other parts of the body, including the lungs, liver, brain, and bones. Treatment typically involves surgical removal of the tumor, followed by chemotherapy and/or radiation therapy to kill any remaining cancer cells.

Prognosis for embryonal carcinoma depends on several factors, including the stage of the disease at diagnosis, the location of the tumor, and the patient's overall health. In general, this type of cancer has a poor prognosis, with a high risk of recurrence even after treatment.

Heterologous transplantation is a type of transplantation where an organ or tissue is transferred from one species to another. This is in contrast to allogeneic transplantation, where the donor and recipient are of the same species, or autologous transplantation, where the donor and recipient are the same individual.

In heterologous transplantation, the immune systems of the donor and recipient are significantly different, which can lead to a strong immune response against the transplanted organ or tissue. This is known as a graft-versus-host disease (GVHD), where the immune cells in the transplanted tissue attack the recipient's body.

Heterologous transplantation is not commonly performed in clinical medicine due to the high risk of rejection and GVHD. However, it may be used in research settings to study the biology of transplantation and to develop new therapies for transplant rejection.

Hemangioblasts are stem cells that are believed to give rise to the endothelial cells that line blood vessels and the blood cells themselves. They are found in the embryonic yolk sac and fetal liver, and they express both endothelial and hematopoietic markers. In adults, hemangioblasts are thought to be involved in the process of vasculogenesis, or the formation of new blood vessels from pre-existing ones.

It's important to note that the existence of true hemangioblasts in adult organisms is still a topic of ongoing research and debate. Some studies suggest that cells with hemangioblastic potential may exist in certain adult tissues, but more research is needed to confirm this and to fully understand their role in vasculogenesis and other processes.

Alkaline phosphatase (ALP) is an enzyme found in various body tissues, including the liver, bile ducts, digestive system, bones, and kidneys. It plays a role in breaking down proteins and minerals, such as phosphate, in the body.

The medical definition of alkaline phosphatase refers to its function as a hydrolase enzyme that removes phosphate groups from molecules at an alkaline pH level. In clinical settings, ALP is often measured through blood tests as a biomarker for various health conditions.

Elevated levels of ALP in the blood may indicate liver or bone diseases, such as hepatitis, cirrhosis, bone fractures, or cancer. Therefore, physicians may order an alkaline phosphatase test to help diagnose and monitor these conditions. However, it is essential to interpret ALP results in conjunction with other diagnostic tests and clinical findings for accurate diagnosis and treatment.

Small interfering RNA (siRNA) is a type of short, double-stranded RNA molecule that plays a role in the RNA interference (RNAi) pathway. The RNAi pathway is a natural cellular process that regulates gene expression by targeting and destroying specific messenger RNA (mRNA) molecules, thereby preventing the translation of those mRNAs into proteins.

SiRNAs are typically 20-25 base pairs in length and are generated from longer double-stranded RNA precursors called hairpin RNAs or dsRNAs by an enzyme called Dicer. Once generated, siRNAs associate with a protein complex called the RNA-induced silencing complex (RISC), which uses one strand of the siRNA (the guide strand) to recognize and bind to complementary sequences in the target mRNA. The RISC then cleaves the target mRNA, leading to its degradation and the inhibition of protein synthesis.

SiRNAs have emerged as a powerful tool for studying gene function and have shown promise as therapeutic agents for a variety of diseases, including viral infections, cancer, and genetic disorders. However, their use as therapeutics is still in the early stages of development, and there are challenges associated with delivering siRNAs to specific cells and tissues in the body.

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

Genetic transduction is a process in molecular biology that describes the transfer of genetic material from one bacterium to another by a viral vector called a bacteriophage (or phage). In this process, the phage infects one bacterium and incorporates a portion of the bacterial DNA into its own genetic material. When the phage then infects a second bacterium, it can transfer the incorporated bacterial DNA to the new host. This can result in the horizontal gene transfer (HGT) of traits such as antibiotic resistance or virulence factors between bacteria.

There are two main types of transduction: generalized and specialized. In generalized transduction, any portion of the bacterial genome can be packaged into the phage particle, leading to a random assortment of genetic material being transferred. In specialized transduction, only specific genes near the site where the phage integrates into the bacterial chromosome are consistently transferred.

It's important to note that genetic transduction is not to be confused with transformation or conjugation, which are other mechanisms of HGT in bacteria.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Fibroblast Growth Factor 4 (FGF4) is a growth factor that belongs to the fibroblast growth factor family. It plays a crucial role in various biological processes, including embryonic development, cell survival, proliferation, and differentiation. Specifically, FGF4 has been implicated in the development of the musculoskeletal system, where it helps regulate the growth and patterning of limbs and bones.

FGF4 exerts its effects by binding to specific receptors on the surface of target cells, known as fibroblast growth factor receptors (FGFRs). This interaction triggers a cascade of intracellular signaling events that ultimately lead to changes in gene expression and cell behavior.

In addition to its role in development, FGF4 has also been implicated in various pathological processes, including cancer. For example, elevated levels of FGF4 have been observed in certain types of tumors, where it may contribute to tumor growth and progression by promoting the survival and proliferation of cancer cells.

A clone is a group of cells that are genetically identical to each other because they are derived from a common ancestor cell through processes such as mitosis or asexual reproduction. Therefore, the term "clone cells" refers to a population of cells that are genetic copies of a single parent cell.

In the context of laboratory research, cells can be cloned by isolating a single cell and allowing it to divide in culture, creating a population of genetically identical cells. This is useful for studying the behavior and characteristics of individual cell types, as well as for generating large quantities of cells for use in experiments.

It's important to note that while clone cells are genetically identical, they may still exhibit differences in their phenotype (physical traits) due to epigenetic factors or environmental influences.

CD (cluster of differentiation) antigens are cell-surface proteins that are expressed on leukocytes (white blood cells) and can be used to identify and distinguish different subsets of these cells. They are important markers in the field of immunology and hematology, and are commonly used to diagnose and monitor various diseases, including cancer, autoimmune disorders, and infectious diseases.

CD antigens are designated by numbers, such as CD4, CD8, CD19, etc., which refer to specific proteins found on the surface of different types of leukocytes. For example, CD4 is a protein found on the surface of helper T cells, while CD8 is found on cytotoxic T cells.

CD antigens can be used as targets for immunotherapy, such as monoclonal antibody therapy, in which antibodies are designed to bind to specific CD antigens and trigger an immune response against cancer cells or infected cells. They can also be used as markers to monitor the effectiveness of treatments and to detect minimal residual disease (MRD) after treatment.

It's important to note that not all CD antigens are exclusive to leukocytes, some can be found on other cell types as well, and their expression can vary depending on the activation state or differentiation stage of the cells.

Tissue scaffolds, also known as bioactive scaffolds or synthetic extracellular matrices, refer to three-dimensional structures that serve as templates for the growth and organization of cells in tissue engineering and regenerative medicine. These scaffolds are designed to mimic the natural extracellular matrix (ECM) found in biological tissues, providing a supportive environment for cell attachment, proliferation, differentiation, and migration.

Tissue scaffolds can be made from various materials, including naturally derived biopolymers (e.g., collagen, alginate, chitosan, hyaluronic acid), synthetic polymers (e.g., polycaprolactone, polylactic acid, poly(lactic-co-glycolic acid)), or a combination of both. The choice of material depends on the specific application and desired properties, such as biocompatibility, biodegradability, mechanical strength, and porosity.

The primary functions of tissue scaffolds include:

1. Cell attachment: Providing surfaces for cells to adhere, spread, and form stable focal adhesions.
2. Mechanical support: Offering a structural framework that maintains the desired shape and mechanical properties of the engineered tissue.
3. Nutrient diffusion: Ensuring adequate transport of nutrients, oxygen, and waste products throughout the scaffold to support cell survival and function.
4. Guided tissue growth: Directing the organization and differentiation of cells through spatial cues and biochemical signals.
5. Biodegradation: Gradually degrading at a rate that matches tissue regeneration, allowing for the replacement of the scaffold with native ECM produced by the cells.

Tissue scaffolds have been used in various applications, such as wound healing, bone and cartilage repair, cardiovascular tissue engineering, and neural tissue regeneration. The design and fabrication of tissue scaffolds are critical aspects of tissue engineering, aiming to create functional substitutes for damaged or diseased tissues and organs.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

Inbred NOD (Nonobese Diabetic) mice are a strain of laboratory mice that are genetically predisposed to develop autoimmune diabetes. This strain was originally developed in Japan and has been widely used as an animal model for studying type 1 diabetes and its complications.

NOD mice typically develop diabetes spontaneously at around 12-14 weeks of age, although the onset and severity of the disease can vary between individual mice. The disease is caused by a breakdown in immune tolerance, leading to an autoimmune attack on the insulin-producing beta cells of the pancreas.

Inbred NOD mice are highly valuable for research purposes because they exhibit many of the same genetic and immunological features as human patients with type 1 diabetes. By studying these mice, researchers can gain insights into the underlying mechanisms of the disease and develop new treatments and therapies.

Cell movement, also known as cell motility, refers to the ability of cells to move independently and change their location within tissue or inside the body. This process is essential for various biological functions, including embryonic development, wound healing, immune responses, and cancer metastasis.

There are several types of cell movement, including:

1. **Crawling or mesenchymal migration:** Cells move by extending and retracting protrusions called pseudopodia or filopodia, which contain actin filaments. This type of movement is common in fibroblasts, immune cells, and cancer cells during tissue invasion and metastasis.
2. **Amoeboid migration:** Cells move by changing their shape and squeezing through tight spaces without forming protrusions. This type of movement is often observed in white blood cells (leukocytes) as they migrate through the body to fight infections.
3. **Pseudopodial extension:** Cells extend pseudopodia, which are temporary cytoplasmic projections containing actin filaments. These protrusions help the cell explore its environment and move forward.
4. **Bacterial flagellar motion:** Bacteria use a whip-like structure called a flagellum to propel themselves through their environment. The rotation of the flagellum is driven by a molecular motor in the bacterial cell membrane.
5. **Ciliary and ependymal movement:** Ciliated cells, such as those lining the respiratory tract and fallopian tubes, have hair-like structures called cilia that beat in coordinated waves to move fluids or mucus across the cell surface.

Cell movement is regulated by a complex interplay of signaling pathways, cytoskeletal rearrangements, and adhesion molecules, which enable cells to respond to environmental cues and navigate through tissues.

The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.

The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.

Proto-oncogene proteins c-kit, also known as CD117 or stem cell factor receptor, are transmembrane receptor tyrosine kinases that play crucial roles in various biological processes, including cell survival, proliferation, differentiation, and migration. They are encoded by the c-KIT gene located on human chromosome 4q12.

These proteins consist of an extracellular ligand-binding domain, a transmembrane domain, and an intracellular tyrosine kinase domain. The binding of their ligand, stem cell factor (SCF), leads to receptor dimerization, autophosphorylation, and activation of several downstream signaling pathways such as PI3K/AKT, MAPK/ERK, and JAK/STAT.

Abnormal activation or mutation of c-kit proto-oncogene proteins has been implicated in the development and progression of various malignancies, including gastrointestinal stromal tumors (GISTs), acute myeloid leukemia (AML), mast cell diseases, and melanoma. Targeted therapies against c-kit, such as imatinib mesylate (Gleevec), have shown promising results in the treatment of these malignancies.

Stromal cells, also known as stromal/stroma cells, are a type of cell found in various tissues and organs throughout the body. They are often referred to as the "connective tissue" or "supporting framework" of an organ because they play a crucial role in maintaining the structure and function of the tissue. Stromal cells include fibroblasts, adipocytes (fat cells), and various types of progenitor/stem cells. They produce and maintain the extracellular matrix, which is the non-cellular component of tissues that provides structural support and biochemical cues for other cells. Stromal cells also interact with immune cells and participate in the regulation of the immune response. In some contexts, "stromal cells" can also refer to cells found in the microenvironment of tumors, which can influence cancer growth and progression.

Culture media is a substance that is used to support the growth of microorganisms or cells in an artificial environment, such as a petri dish or test tube. It typically contains nutrients and other factors that are necessary for the growth and survival of the organisms being cultured. There are many different types of culture media, each with its own specific formulation and intended use. Some common examples include blood agar, which is used to culture bacteria; Sabouraud dextrose agar, which is used to culture fungi; and Eagle's minimum essential medium, which is used to culture animal cells.

Gene silencing is a process by which the expression of a gene is blocked or inhibited, preventing the production of its corresponding protein. This can occur naturally through various mechanisms such as RNA interference (RNAi), where small RNAs bind to and degrade specific mRNAs, or DNA methylation, where methyl groups are added to the DNA molecule, preventing transcription. Gene silencing can also be induced artificially using techniques such as RNAi-based therapies, antisense oligonucleotides, or CRISPR-Cas9 systems, which allow for targeted suppression of gene expression in research and therapeutic applications.

Beta-catenin is a protein that plays a crucial role in gene transcription and cell-cell adhesion. It is a key component of the Wnt signaling pathway, which regulates various processes such as cell proliferation, differentiation, and migration during embryonic development and tissue homeostasis in adults.

In the absence of Wnt signals, beta-catenin forms a complex with other proteins, including adenomatous polyposis coli (APC) and axin, which targets it for degradation by the proteasome. When Wnt ligands bind to their receptors, this complex is disrupted, allowing beta-catenin to accumulate in the cytoplasm and translocate to the nucleus. In the nucleus, beta-catenin interacts with T cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription factors to activate the transcription of target genes involved in cell fate determination, survival, and proliferation.

Mutations in the genes encoding components of the Wnt signaling pathway, including beta-catenin, have been implicated in various human diseases, such as cancer, developmental disorders, and degenerative conditions.

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is an enzyme that plays a crucial role in the salvage pathway of nucleotide synthesis. This enzyme catalyzes the conversion of hypoxanthine and guanine to their respective nucleotides, inosine monophosphate (IMP) and guanosine monophosphate (GMP), by transferring the phosphoribosyl group from 5-phosphoribosyl-1 pyrophosphate (PRPP) to the purine bases.

HGPRT deficiency is a genetic disorder known as Lesch-Nyhan syndrome, which is characterized by mental retardation, self-mutilation, spasticity, and uric acid overproduction due to the accumulation of hypoxanthine and guanine. This disorder is caused by mutations in the HPRT1 gene, leading to a decrease or absence of HGPRT enzyme activity.

Chondrogenesis is the process of cartilage formation during embryonic development and in the healing of certain types of injuries. It involves the differentiation of mesenchymal stem cells into chondrocytes, which are the specialized cells that produce and maintain the extracellular matrix of cartilage.

During chondrogenesis, the mesenchymal stem cells condense and form a template for the future cartilaginous tissue. These cells then differentiate into chondrocytes, which begin to produce and deposit collagen type II, proteoglycans, and other extracellular matrix components that give cartilage its unique biochemical and mechanical properties.

Chondrogenesis is a critical process for the development of various structures in the body, including the skeletal system, where it plays a role in the formation of articular cartilage, growth plates, and other types of cartilage. Understanding the molecular mechanisms that regulate chondrogenesis is important for developing therapies to treat cartilage injuries and degenerative diseases such as osteoarthritis.

Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) is a tyrosine kinase receptor that is primarily expressed on vascular endothelial cells. It is a crucial regulator of angiogenesis, the process of new blood vessel formation from pre-existing vessels. VEGFR-2 is activated by binding to its ligand, Vascular Endothelial Growth Factor-A (VEGF-A), leading to receptor dimerization and autophosphorylation. This activation triggers a cascade of intracellular signaling events that promote endothelial cell proliferation, migration, survival, and vascular permeability, all essential steps in the angiogenic process.

VEGFR-2 plays a significant role in physiological and pathological conditions associated with angiogenesis, such as embryonic development, wound healing, tumor growth, and retinopathies. Inhibition of VEGFR-2 signaling has been an attractive target for anti-angiogenic therapies in various diseases, including cancer and age-related macular degeneration.

Gene Regulatory Networks (GRNs) are complex systems of molecular interactions that regulate the expression of genes within an organism. These networks consist of various types of regulatory elements, including transcription factors, enhancers, promoters, and silencers, which work together to control when, where, and to what extent a gene is expressed.

In GRNs, transcription factors bind to specific DNA sequences in the regulatory regions of target genes, either activating or repressing their transcription into messenger RNA (mRNA). This process is influenced by various intracellular and extracellular signals that modulate the activity of transcription factors, allowing for precise regulation of gene expression in response to changing environmental conditions.

The structure and behavior of GRNs can be represented as a network of nodes (genes) and edges (regulatory interactions), with the strength and directionality of these interactions determined by the specific molecular mechanisms involved. Understanding the organization and dynamics of GRNs is crucial for elucidating the underlying causes of various biological processes, including development, differentiation, homeostasis, and disease.

Luminescent proteins are a type of protein that emit light through a chemical reaction, rather than by absorbing and re-emitting light like fluorescent proteins. This process is called bioluminescence. The light emitted by luminescent proteins is often used in scientific research as a way to visualize and track biological processes within cells and organisms.

One of the most well-known luminescent proteins is Green Fluorescent Protein (GFP), which was originally isolated from jellyfish. However, GFP is actually a fluorescent protein, not a luminescent one. A true example of a luminescent protein is the enzyme luciferase, which is found in fireflies and other bioluminescent organisms. When luciferase reacts with its substrate, luciferin, it produces light through a process called oxidation.

Luminescent proteins have many applications in research, including as reporters for gene expression, as markers for protein-protein interactions, and as tools for studying the dynamics of cellular processes. They are also used in medical imaging and diagnostics, as well as in the development of new therapies.

Genetic recombination is the process by which genetic material is exchanged between two similar or identical molecules of DNA during meiosis, resulting in new combinations of genes on each chromosome. This exchange occurs during crossover, where segments of DNA are swapped between non-sister homologous chromatids, creating genetic diversity among the offspring. It is a crucial mechanism for generating genetic variability and facilitating evolutionary change within populations. Additionally, recombination also plays an essential role in DNA repair processes through mechanisms such as homologous recombinational repair (HRR) and non-homologous end joining (NHEJ).

Genetic engineering, also known as genetic modification, is a scientific process where the DNA or genetic material of an organism is manipulated to bring about a change in its characteristics. This is typically done by inserting specific genes into the organism's genome using various molecular biology techniques. These new genes may come from the same species (cisgenesis) or a different species (transgenesis). The goal is to produce a desired trait, such as resistance to pests, improved nutritional content, or increased productivity. It's widely used in research, medicine, and agriculture. However, it's important to note that the use of genetically engineered organisms can raise ethical, environmental, and health concerns.

Genomic imprinting is a epigenetic process that leads to the differential expression of genes depending on their parental origin. It involves the methylation of certain CpG sites in the DNA, which results in the silencing of one of the two copies of a gene, either the maternal or paternal allele. This means that only one copy of the gene is active and expressed, while the other is silent.

This phenomenon is critical for normal development and growth, and it plays a role in the regulation of genes involved in growth and behavior. Genomic imprinting is also associated with certain genetic disorders, such as Prader-Willi and Angelman syndromes, which occur when there are errors in the imprinting process that lead to the absence or abnormal expression of certain genes.

It's important to note that genomic imprinting is a complex and highly regulated process that is not yet fully understood. Research in this area continues to provide new insights into the mechanisms underlying gene regulation and their impact on human health and disease.

A karyotype is a method used in genetics to describe the number and visual appearance of chromosomes in the nucleus of a cell. It includes the arrangement of the chromosomes by length, position of the centromeres, and banding pattern. A karyotype is often represented as a photograph or image of an individual's chromosomes, arranged in pairs from largest to smallest, that has been stained to show the bands of DNA. This information can be used to identify genetic abnormalities, such as extra or missing chromosomes, or structural changes, such as deletions, duplications, or translocations. A karyotype is typically obtained by culturing cells from a sample of blood or tissue, then arresting the cell division at metaphase and staining the chromosomes to make them visible for analysis.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Down-regulation is a process that occurs in response to various stimuli, where the number or sensitivity of cell surface receptors or the expression of specific genes is decreased. This process helps maintain homeostasis within cells and tissues by reducing the ability of cells to respond to certain signals or molecules.

In the context of cell surface receptors, down-regulation can occur through several mechanisms:

1. Receptor internalization: After binding to their ligands, receptors can be internalized into the cell through endocytosis. Once inside the cell, these receptors may be degraded or recycled back to the cell surface in smaller numbers.
2. Reduced receptor synthesis: Down-regulation can also occur at the transcriptional level, where the expression of genes encoding for specific receptors is decreased, leading to fewer receptors being produced.
3. Receptor desensitization: Prolonged exposure to a ligand can lead to a decrease in receptor sensitivity or affinity, making it more difficult for the cell to respond to the signal.

In the context of gene expression, down-regulation refers to the decreased transcription and/or stability of specific mRNAs, leading to reduced protein levels. This process can be induced by various factors, including microRNA (miRNA)-mediated regulation, histone modification, or DNA methylation.

Down-regulation is an essential mechanism in many physiological processes and can also contribute to the development of several diseases, such as cancer and neurodegenerative disorders.

Trans-activators are proteins that increase the transcriptional activity of a gene or a set of genes. They do this by binding to specific DNA sequences and interacting with the transcription machinery, thereby enhancing the recruitment and assembly of the complexes needed for transcription. In some cases, trans-activators can also modulate the chromatin structure to make the template more accessible to the transcription machinery.

In the context of HIV (Human Immunodeficiency Virus) infection, the term "trans-activator" is often used specifically to refer to the Tat protein. The Tat protein is a viral regulatory protein that plays a critical role in the replication of HIV by activating the transcription of the viral genome. It does this by binding to a specific RNA structure called the Trans-Activation Response Element (TAR) located at the 5' end of all nascent HIV transcripts, and recruiting cellular cofactors that enhance the processivity and efficiency of RNA polymerase II, leading to increased viral gene expression.

Long non-coding RNA (lncRNA) is a type of RNA molecule that is longer than 200 nucleotides and does not encode for proteins. They are involved in various cellular processes such as regulation of gene expression, chromosome remodeling, and modulation of protein function. LncRNAs can be located in the nucleus or cytoplasm and can interact with DNA, RNA, and proteins to bring about their functions. Dysregulation of lncRNAs has been implicated in various human diseases, including cancer.

Intermediate filament proteins (IFPs) are a type of cytoskeletal protein that form the intermediate filaments (IFs), which are one of the three major components of the cytoskeleton in eukaryotic cells, along with microtubules and microfilaments. These proteins have a unique structure, characterized by an alpha-helical rod domain flanked by non-helical head and tail domains.

Intermediate filament proteins are classified into six major types based on their amino acid sequence: Type I (acidic) and Type II (basic) keratins, Type III (desmin, vimentin, glial fibrillary acidic protein, and peripherin), Type IV (neurofilaments), Type V (lamins), and Type VI (nestin). Each type of IFP has a distinct pattern of expression in different tissues and cell types.

Intermediate filament proteins play important roles in maintaining the structural integrity and mechanical strength of cells, providing resilience to mechanical stress, and regulating various cellular processes such as cell division, migration, and signal transduction. Mutations in IFP genes have been associated with several human diseases, including cancer, neurodegenerative disorders, and genetic skin fragility disorders.

Endothelial cells are the type of cells that line the inner surface of blood vessels, lymphatic vessels, and heart chambers. They play a crucial role in maintaining vascular homeostasis by controlling vasomotor tone, coagulation, platelet activation, and inflammation. Endothelial cells also regulate the transport of molecules between the blood and surrounding tissues, and contribute to the maintenance of the structural integrity of the vasculature. They are flat, elongated cells with a unique morphology that allows them to form a continuous, nonthrombogenic lining inside the vessels. Endothelial cells can be isolated from various tissues and cultured in vitro for research purposes.

A genome is the complete set of genetic material (DNA, or in some viruses, RNA) present in a single cell of an organism. It includes all of the genes, both coding and noncoding, as well as other regulatory elements that together determine the unique characteristics of that organism. The human genome, for example, contains approximately 3 billion base pairs and about 20,000-25,000 protein-coding genes.

The term "genome" was first coined by Hans Winkler in 1920, derived from the word "gene" and the suffix "-ome," which refers to a complete set of something. The study of genomes is known as genomics.

Understanding the genome can provide valuable insights into the genetic basis of diseases, evolution, and other biological processes. With advancements in sequencing technologies, it has become possible to determine the entire genomic sequence of many organisms, including humans, and use this information for various applications such as personalized medicine, gene therapy, and biotechnology.

Notch receptors are a type of transmembrane receptor proteins that play crucial roles in cell-cell communication and regulation of various biological processes, including cell fate determination, differentiation, proliferation, and apoptosis. These receptors are highly conserved across species and are essential for normal development and tissue homeostasis.

The Notch signaling pathway is initiated when the extracellular domain of a Notch receptor on one cell interacts with its ligand (such as Delta or Jagged) on an adjacent cell. This interaction triggers a series of proteolytic cleavage events that release the intracellular domain of the Notch receptor, which then translocates to the nucleus and regulates gene expression by interacting with transcription factors like CSL (CBF1/RBP-Jκ/Su(H)/Lag-1).

There are four known Notch receptors in humans (Notch1-4) that share a similar structure, consisting of an extracellular domain containing multiple epidermal growth factor (EGF)-like repeats, a transmembrane domain, and an intracellular domain. Mutations or dysregulation of the Notch signaling pathway have been implicated in various human diseases, including cancer, cardiovascular disorders, and developmental abnormalities.

"Cell count" is a medical term that refers to the process of determining the number of cells present in a given volume or sample of fluid or tissue. This can be done through various laboratory methods, such as counting individual cells under a microscope using a specialized grid called a hemocytometer, or using automated cell counters that use light scattering and electrical impedance techniques to count and classify different types of cells.

Cell counts are used in a variety of medical contexts, including hematology (the study of blood and blood-forming tissues), microbiology (the study of microscopic organisms), and pathology (the study of diseases and their causes). For example, a complete blood count (CBC) is a routine laboratory test that includes a white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin level, hematocrit value, and platelet count. Abnormal cell counts can indicate the presence of various medical conditions, such as infections, anemia, or leukemia.

Dehumanization is a process or phenomenon in which a person or group is treated or regarded as lacking basic human qualities and emotions, such as compassion, empathy, or individuality. This can occur through various means, including language, propaganda, social policies, or actions that deprive individuals of their rights, dignity, or freedom. Dehumanization can have serious consequences, including increased prejudice, discrimination, and violence against the targeted group. It is considered a violation of basic human rights and is often associated with totalitarian regimes, genocide, and other large-scale human rights abuses.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

A homozygote is an individual who has inherited the same allele (version of a gene) from both parents and therefore possesses two identical copies of that allele at a specific genetic locus. This can result in either having two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive). In contrast, a heterozygote has inherited different alleles from each parent for a particular gene.

The term "homozygote" is used in genetics to describe the genetic makeup of an individual at a specific locus on their chromosomes. Homozygosity can play a significant role in determining an individual's phenotype (observable traits), as having two identical alleles can strengthen the expression of certain characteristics compared to having just one dominant and one recessive allele.

GATA4 is a transcription factor that belongs to the GATA family of zinc finger proteins, which are characterized by their ability to bind to DNA sequences containing the core motif (A/T)GATA(A/G). GATA4 specifically recognizes and binds to GATA motifs in the promoter and enhancer regions of target genes, where it can modulate their transcription.

GATA4 is widely expressed in various tissues, including the heart, gut, lungs, and gonads. In the heart, GATA4 plays critical roles during cardiac development, such as promoting cardiomyocyte differentiation and regulating heart tube formation. It also continues to be expressed in adult hearts, where it helps maintain cardiac function and can contribute to heart repair after injury.

Mutations in the GATA4 gene have been associated with congenital heart defects, suggesting its essential role in heart development. Additionally, GATA4 has been implicated in cancer progression, particularly in gastrointestinal and lung cancers, where it can act as an oncogene by promoting cell proliferation and survival.

"Left-right determination factors" refer to the genetic and molecular mechanisms that establish the left-right asymmetry during embryonic development. These factors determine which side of the body will become the left and which will become the right. The process is critical for the proper development and function of various organs, including the heart, lungs, and gut.

In humans, the primary left-right determination factor is a gene called NODAL, which is expressed on the left side of the embryo and initiates a cascade of molecular events that lead to the establishment of left-right asymmetry. Other genes, such as PITX2 and LEFTY2, are also involved in this process and help to amplify and maintain the left-right asymmetry.

Defects in left-right determination factors can result in a variety of congenital abnormalities, including heterotaxy syndrome, in which the organs are arranged in mirror-image patterns or randomly on both sides of the body.

Fibroblast Growth Factor 2 (FGF-2), also known as basic fibroblast growth factor, is a protein involved in various biological processes such as cell growth, proliferation, and differentiation. It plays a crucial role in wound healing, embryonic development, and angiogenesis (the formation of new blood vessels). FGF-2 is produced and secreted by various cells, including fibroblasts, and exerts its effects by binding to specific receptors on the cell surface, leading to activation of intracellular signaling pathways. It has been implicated in several diseases, including cancer, where it can contribute to tumor growth and progression.

A "mutant strain of mice" in a medical context refers to genetically engineered mice that have specific genetic mutations introduced into their DNA. These mutations can be designed to mimic certain human diseases or conditions, allowing researchers to study the underlying biological mechanisms and test potential therapies in a controlled laboratory setting.

Mutant strains of mice are created through various techniques, including embryonic stem cell manipulation, gene editing technologies such as CRISPR-Cas9, and radiation-induced mutagenesis. These methods allow scientists to introduce specific genetic changes into the mouse genome, resulting in mice that exhibit altered physiological or behavioral traits.

These strains of mice are widely used in biomedical research because their short lifespan, small size, and high reproductive rate make them an ideal model organism for studying human diseases. Additionally, the mouse genome has been well-characterized, and many genetic tools and resources are available to researchers working with these animals.

Examples of mutant strains of mice include those that carry mutations in genes associated with cancer, neurodegenerative disorders, metabolic diseases, and immunological conditions. These mice provide valuable insights into the pathophysiology of human diseases and help advance our understanding of potential therapeutic interventions.

Physiologic neovascularization is the natural and controlled formation of new blood vessels in the body, which occurs as a part of normal growth and development, as well as in response to tissue repair and wound healing. This process involves the activation of endothelial cells, which line the interior surface of blood vessels, and their migration, proliferation, and tube formation to create new capillaries. Physiologic neovascularization is tightly regulated by a balance of pro-angiogenic and anti-angiogenic factors, ensuring that it occurs only when and where it is needed. It plays crucial roles in various physiological processes, such as embryonic development, tissue regeneration, and wound healing.

Neuroepithelial cells are stem cells that line the developing central nervous system (CNS) in embryos. These cells have the ability to differentiate into various cell types, including neurons and glial cells, which make up the brain and spinal cord. Neuroepithelial cells form a pseudostratified epithelium, meaning that the nuclei of the cells are at varying heights within the cell layer, giving it a striped appearance. These cells play a crucial role in the development and growth of the CNS.

Polycomb Repressive Complex 2 (PRC2) is a multi-protein complex that plays a crucial role in the epigenetic regulation of gene expression, primarily through the modification of histone proteins. It is named after the Polycomb group genes that were initially identified in Drosophila melanogaster (fruit flies) due to their involvement in maintaining the repressed state of homeotic genes during development.

The core components of PRC2 include:

1. Enhancer of Zeste Homolog 2 (EZH2) or its paralog EZH1: These are histone methyltransferases that catalyze the addition of methyl groups to lysine 27 on histone H3 (H3K27). The trimethylation of this residue (H3K27me3) is a hallmark of PRC2-mediated repression.
2. Suppressor of Zeste 12 (SUZ12): This protein is essential for the stability and methyltransferase activity of the complex.
3. Embryonic Ectoderm Development (EED): This protein recognizes and binds to the H3K27me3 mark, enhancing the methyltransferase activity of EZH2/EZH1 and promoting the spreading of the repressive mark along chromatin.
4. Retinoblastoma-associated Protein 46/48 (RbAP46/48): These are histone binding proteins that facilitate the interaction between PRC2 and nucleosomes, thereby contributing to the specificity of its targeting.

PRC2 is involved in various cellular processes, such as differentiation, proliferation, and development, by modulating the expression of genes critical for these functions. Dysregulation of PRC2 has been implicated in several human diseases, including cancers, where it often exhibits aberrant activity or mislocalization, leading to altered gene expression profiles.

Laminin is a family of proteins that are an essential component of the basement membrane, which is a specialized type of extracellular matrix. Laminins are large trimeric molecules composed of three different chains: α, β, and γ. There are five different α chains, three different β chains, and three different γ chains that can combine to form at least 15 different laminin isoforms.

Laminins play a crucial role in maintaining the structure and integrity of basement membranes by interacting with other components of the extracellular matrix, such as collagen IV, and cell surface receptors, such as integrins. They are involved in various biological processes, including cell adhesion, differentiation, migration, and survival.

Laminin dysfunction has been implicated in several human diseases, including cancer, diabetic nephropathy, and muscular dystrophy.

Cell aggregation is the process by which individual cells come together and adhere to each other to form a group or cluster. This phenomenon can occur naturally during embryonic development, tissue repair, and wound healing, as well as in the formation of multicellular organisms such as slime molds. In some cases, cell aggregation may also be induced in the laboratory setting through the use of various techniques, including the use of cell culture surfaces that promote cell-to-cell adhesion or the addition of factors that stimulate the expression of adhesion molecules on the cell surface.

Cell aggregation can be influenced by a variety of factors, including the type and properties of the cells involved, as well as environmental conditions such as pH, temperature, and nutrient availability. The ability of cells to aggregate is often mediated by the presence of adhesion molecules on the cell surface, such as cadherins, integrins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs). These molecules interact with each other and with extracellular matrix components to promote cell-to-cell adhesion and maintain the stability of the aggregate.

In some contexts, abnormal or excessive cell aggregation can contribute to the development of diseases such as cancer, fibrosis, and inflammatory disorders. For example, the aggregation of cancer cells can facilitate their invasion and metastasis, while the accumulation of fibrotic cells in tissues can lead to organ dysfunction and failure. Understanding the mechanisms that regulate cell aggregation is therefore an important area of research with potential implications for the development of new therapies and treatments for a variety of diseases.

Teratogens are substances, such as certain medications, chemicals, or infectious agents, that can cause birth defects or abnormalities in the developing fetus when a woman is exposed to them during pregnancy. They can interfere with the normal development of the fetus and lead to a range of problems, including physical deformities, intellectual disabilities, and sensory impairments. Examples of teratogens include alcohol, tobacco smoke, some prescription medications, and infections like rubella (German measles). It is important for women who are pregnant or planning to become pregnant to avoid exposure to known teratogens as much as possible.

Microarray analysis is a laboratory technique used to measure the expression levels of large numbers of genes (or other types of DNA sequences) simultaneously. This technology allows researchers to monitor the expression of thousands of genes in a single experiment, providing valuable information about which genes are turned on or off in response to various stimuli or diseases.

In microarray analysis, samples of RNA from cells or tissues are labeled with fluorescent dyes and then hybridized to a solid surface (such as a glass slide) onto which thousands of known DNA sequences have been spotted in an organized array. The intensity of the fluorescence at each spot on the array is proportional to the amount of RNA that has bound to it, indicating the level of expression of the corresponding gene.

Microarray analysis can be used for a variety of applications, including identifying genes that are differentially expressed between healthy and diseased tissues, studying genetic variations in populations, and monitoring gene expression changes over time or in response to environmental factors. However, it is important to note that microarray data must be analyzed carefully using appropriate statistical methods to ensure the accuracy and reliability of the results.

Inbred strains of mice are defined as lines of mice that have been brother-sister mated for at least 20 consecutive generations. This results in a high degree of homozygosity, where the mice of an inbred strain are genetically identical to one another, with the exception of spontaneous mutations.

Inbred strains of mice are widely used in biomedical research due to their genetic uniformity and stability, which makes them useful for studying the genetic basis of various traits, diseases, and biological processes. They also provide a consistent and reproducible experimental system, as compared to outbred or genetically heterogeneous populations.

Some commonly used inbred strains of mice include C57BL/6J, BALB/cByJ, DBA/2J, and 129SvEv. Each strain has its own unique genetic background and phenotypic characteristics, which can influence the results of experiments. Therefore, it is important to choose the appropriate inbred strain for a given research question.

"Gene knockout techniques" refer to a group of biomedical research methods used in genetics and molecular biology to study the function of specific genes in an organism. These techniques involve introducing a deliberate, controlled genetic modification that results in the inactivation or "knockout" of a particular gene. This is typically achieved through various methods such as homologous recombination, where a modified version of the gene with inserted mutations is introduced into the organism's genome, replacing the original functional gene. The resulting organism, known as a "knockout mouse" or other model organisms, lacks the function of the targeted gene and can be used to study its role in biological processes, disease development, and potential therapeutic interventions.

Genetic techniques refer to a variety of methods and tools used in the field of genetics to study, manipulate, and understand genes and their functions. These techniques can be broadly categorized into those that allow for the identification and analysis of specific genes or genetic variations, and those that enable the manipulation of genes in order to understand their function or to modify them for therapeutic purposes.

Some examples of genetic analysis techniques include:

1. Polymerase Chain Reaction (PCR): a method used to amplify specific DNA sequences, allowing researchers to study small amounts of DNA.
2. Genome sequencing: the process of determining the complete DNA sequence of an organism's genome.
3. Genotyping: the process of identifying and analyzing genetic variations or mutations in an individual's DNA.
4. Linkage analysis: a method used to identify genetic loci associated with specific traits or diseases by studying patterns of inheritance within families.
5. Expression profiling: the measurement of gene expression levels in cells or tissues, often using microarray technology.

Some examples of genetic manipulation techniques include:

1. Gene editing: the use of tools such as CRISPR-Cas9 to modify specific genes or genetic sequences.
2. Gene therapy: the introduction of functional genes into cells or tissues to replace missing or nonfunctional genes.
3. Transgenic technology: the creation of genetically modified organisms (GMOs) by introducing foreign DNA into their genomes.
4. RNA interference (RNAi): the use of small RNA molecules to silence specific genes and study their function.
5. Induced pluripotent stem cells (iPSCs): the creation of stem cells from adult cells through genetic reprogramming, allowing for the study of development and disease in vitro.

Cryopreservation is a medical procedure that involves the preservation of cells, tissues, or organs by cooling them to very low temperatures, typically below -150°C. This is usually achieved using liquid nitrogen. The low temperature slows down or stops biological activity, including chemical reactions and cellular metabolism, which helps to prevent damage and decay.

The cells, tissues, or organs that are being cryopreserved must be treated with a cryoprotectant solution before cooling to prevent the formation of ice crystals, which can cause significant damage. Once cooled, the samples are stored in specialized containers or tanks until they are needed for use.

Cryopreservation is commonly used in assisted reproductive technologies, such as the preservation of sperm, eggs, and embryos for fertility treatments. It is also used in research, including the storage of cell lines and stem cells, and in clinical settings, such as the preservation of skin grafts and corneas for transplantation.

Organ specificity, in the context of immunology and toxicology, refers to the phenomenon where a substance (such as a drug or toxin) or an immune response primarily affects certain organs or tissues in the body. This can occur due to various reasons such as:

1. The presence of specific targets (like antigens in the case of an immune response or receptors in the case of drugs) that are more abundant in these organs.
2. The unique properties of certain cells or tissues that make them more susceptible to damage.
3. The way a substance is metabolized or cleared from the body, which can concentrate it in specific organs.

For example, in autoimmune diseases, organ specificity describes immune responses that are directed against antigens found only in certain organs, such as the thyroid gland in Hashimoto's disease. Similarly, some toxins or drugs may have a particular affinity for liver cells, leading to liver damage or specific drug interactions.

Intercellular signaling peptides and proteins are molecules that mediate communication and interaction between different cells in living organisms. They play crucial roles in various biological processes, including cell growth, differentiation, migration, and apoptosis (programmed cell death). These signals can be released into the extracellular space, where they bind to specific receptors on the target cell's surface, triggering intracellular signaling cascades that ultimately lead to a response.

Peptides are short chains of amino acids, while proteins are larger molecules made up of one or more polypeptide chains. Both can function as intercellular signaling molecules by acting as ligands for cell surface receptors or by being cleaved from larger precursor proteins and released into the extracellular space. Examples of intercellular signaling peptides and proteins include growth factors, cytokines, chemokines, hormones, neurotransmitters, and their respective receptors.

These molecules contribute to maintaining homeostasis within an organism by coordinating cellular activities across tissues and organs. Dysregulation of intercellular signaling pathways has been implicated in various diseases, such as cancer, autoimmune disorders, and neurodegenerative conditions. Therefore, understanding the mechanisms underlying intercellular signaling is essential for developing targeted therapies to treat these disorders.

Cell tracking is a technique used in medical research and clinical applications to monitor the movement, behavior, and fate of cells over time. This process typically involves labeling cells with a marker such as a dye, fluorescent protein, or magnetic nanoparticle, which allows researchers to observe and analyze the cells using various imaging techniques.

The labeled cells can be tracked individually or in groups, enabling the study of cell-cell interactions, migration patterns, proliferation rates, and other biological processes. Cell tracking has numerous applications in fields such as regenerative medicine, cancer research, developmental biology, and drug discovery.

There are different methods for cell tracking, including:

1. Intravital microscopy: This technique involves surgically implanting a microscope into a living organism to directly observe cells in their native environment over time.
2. Two-photon microscopy: Using laser pulses to excite fluorescent markers, this method allows for deep tissue imaging with minimal photodamage.
3. Magnetic resonance imaging (MRI): By labeling cells with magnetic nanoparticles, researchers can use MRI to non-invasively track cell movement and distribution within an organism.
4. Positron emission tomography (PET) and computed tomography (CT) scans: Radioactive tracers can be used to label cells for tracking via PET or CT imaging techniques.
5. Image analysis software: Specialized software can be used to analyze images captured through various imaging techniques, enabling researchers to track cell movement and behavior over time.

Overall, cell tracking is an essential tool in medical research, providing valuable insights into the dynamics of cellular processes and contributing to advancements in diagnostic and therapeutic strategies.

Trophoblasts are specialized cells that make up the outer layer of a blastocyst, which is a hollow ball of cells that forms in the earliest stages of embryonic development. In humans, this process occurs about 5-6 days after fertilization. The blastocyst consists of an inner cell mass (which will eventually become the embryo) and an outer layer of trophoblasts.

Trophoblasts play a crucial role in implantation, which is the process by which the blastocyst attaches to and invades the lining of the uterus. Once implanted, the trophoblasts differentiate into two main layers: the cytotrophoblasts (which are closer to the inner cell mass) and the syncytiotrophoblasts (which form a multinucleated layer that is in direct contact with the maternal tissues).

The cytotrophoblasts proliferate and fuse to form the syncytiotrophoblasts, which have several important functions. They secrete enzymes that help to degrade and remodel the extracellular matrix of the uterine lining, allowing the blastocyst to implant more deeply. They also form a barrier between the maternal and fetal tissues, helping to protect the developing embryo from the mother's immune system.

Additionally, trophoblasts are responsible for the formation of the placenta, which provides nutrients and oxygen to the developing fetus and removes waste products. The syncytiotrophoblasts in particular play a key role in this process by secreting hormones such as human chorionic gonadotropin (hCG), which helps to maintain pregnancy, and by forming blood vessels that allow for the exchange of nutrients and waste between the mother and fetus.

Abnormalities in trophoblast development or function can lead to a variety of pregnancy-related complications, including preeclampsia, intrauterine growth restriction, and gestational trophoblastic diseases such as hydatidiform moles and choriocarcinomas.

The yolk sac is a structure that forms in the early stages of an embryo's development. It is a extra-embryonic membrane, which means it exists outside of the developing embryo, and it plays a critical role in providing nutrients to the growing embryo during the initial stages of development.

In more detail, the yolk sac is responsible for producing blood cells, contributing to the formation of the early circulatory system, and storing nutrients that are absorbed from the yolk material inside the egg or uterus. The yolk sac also has a role in the development of the gut and the immune system.

As the embryo grows and the placenta develops, the yolk sac's function becomes less critical, and it eventually degenerates. However, remnants of the yolk sac can sometimes persist and may be found in the developing fetus or newborn baby. In some cases, abnormalities in the development or regression of the yolk sac can lead to developmental problems or congenital disorders.

Growth Differentiation Factor 3 (GDF3) is a member of the transforming growth factor-beta (TGF-β) superfamily, which are signaling proteins involved in cell growth, differentiation, and apoptosis. GDF3 plays crucial roles during embryonic development, including mesoderm formation, endoderm differentiation, and left-right patterning. It is also expressed in adult tissues, such as the heart, brain, and reproductive organs, although its functions in these contexts are less well understood. GDF3 is secreted as a dimeric protein and signals through a heteromeric complex of type I and type II serine/threonine kinase receptors, leading to the activation of intracellular SMAD proteins and downstream transcriptional responses.

Fetal blood refers to the blood circulating in a fetus during pregnancy. It is essential for the growth and development of the fetus, as it carries oxygen and nutrients from the placenta to the developing tissues and organs. Fetal blood also removes waste products, such as carbon dioxide, from the fetal tissues and transports them to the placenta for elimination.

Fetal blood has several unique characteristics that distinguish it from adult blood. For example, fetal hemoglobin (HbF) is the primary type of hemoglobin found in fetal blood, whereas adults primarily have adult hemoglobin (HbA). Fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin, which allows it to more efficiently extract oxygen from the maternal blood in the placenta.

Additionally, fetal blood contains a higher proportion of reticulocytes (immature red blood cells) and nucleated red blood cells compared to adult blood. These differences reflect the high turnover rate of red blood cells in the developing fetus and the need for rapid growth and development.

Examination of fetal blood can provide important information about the health and well-being of the fetus during pregnancy. For example, fetal blood sampling (also known as cordocentesis or percutaneous umbilical blood sampling) can be used to diagnose genetic disorders, infections, and other conditions that may affect fetal development. However, this procedure carries risks, including preterm labor, infection, and fetal loss, and is typically only performed when there is a significant risk of fetal compromise or when other diagnostic tests have been inconclusive.

Hepatocytes are the predominant type of cells in the liver, accounting for about 80% of its cytoplasmic mass. They play a key role in protein synthesis, protein storage, transformation of carbohydrates, synthesis of cholesterol, bile salts and phospholipids, detoxification, modification, and excretion of exogenous and endogenous substances, initiation of formation and secretion of bile, and enzyme production. Hepatocytes are essential for the maintenance of homeostasis in the body.

Real-Time Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences in real-time. It is a sensitive and specific method that allows for the quantification of target nucleic acids, such as DNA or RNA, through the use of fluorescent reporter molecules.

The RT-PCR process involves several steps: first, the template DNA is denatured to separate the double-stranded DNA into single strands. Then, primers (short sequences of DNA) specific to the target sequence are added and allowed to anneal to the template DNA. Next, a heat-stable enzyme called Taq polymerase adds nucleotides to the annealed primers, extending them along the template DNA until a new double-stranded DNA molecule is formed.

During each amplification cycle, fluorescent reporter molecules are added that bind specifically to the newly synthesized DNA. As more and more copies of the target sequence are generated, the amount of fluorescence increases in proportion to the number of copies present. This allows for real-time monitoring of the PCR reaction and quantification of the target nucleic acid.

RT-PCR is commonly used in medical diagnostics, research, and forensics to detect and quantify specific DNA or RNA sequences. It has been widely used in the diagnosis of infectious diseases, genetic disorders, and cancer, as well as in the identification of microbial pathogens and the detection of gene expression.

Proto-oncogene proteins, such as c-Myc, are crucial regulators of normal cell growth, differentiation, and apoptosis (programmed cell death). When proto-oncogenes undergo mutations or alterations in their regulation, they can become overactive or overexpressed, leading to the formation of oncogenes. Oncogenic forms of c-Myc contribute to uncontrolled cell growth and division, which can ultimately result in cancer development.

The c-Myc protein is a transcription factor that binds to specific DNA sequences, influencing the expression of target genes involved in various cellular processes, such as:

1. Cell cycle progression: c-Myc promotes the expression of genes required for the G1 to S phase transition, driving cells into the DNA synthesis and division phase.
2. Metabolism: c-Myc regulates genes associated with glucose metabolism, glycolysis, and mitochondrial function, enhancing energy production in rapidly dividing cells.
3. Apoptosis: c-Myc can either promote or inhibit apoptosis, depending on the cellular context and the presence of other regulatory factors.
4. Differentiation: c-Myc generally inhibits differentiation by repressing genes that are necessary for specialized cell functions.
5. Angiogenesis: c-Myc can induce the expression of pro-angiogenic factors, promoting the formation of new blood vessels to support tumor growth.

Dysregulation of c-Myc is frequently observed in various types of cancer, making it an important therapeutic target for cancer treatment.

Southern blotting is a type of membrane-based blotting technique that is used in molecular biology to detect and locate specific DNA sequences within a DNA sample. This technique is named after its inventor, Edward M. Southern.

In Southern blotting, the DNA sample is first digested with one or more restriction enzymes, which cut the DNA at specific recognition sites. The resulting DNA fragments are then separated based on their size by gel electrophoresis. After separation, the DNA fragments are denatured to convert them into single-stranded DNA and transferred onto a nitrocellulose or nylon membrane.

Once the DNA has been transferred to the membrane, it is hybridized with a labeled probe that is complementary to the sequence of interest. The probe can be labeled with radioactive isotopes, fluorescent dyes, or chemiluminescent compounds. After hybridization, the membrane is washed to remove any unbound probe and then exposed to X-ray film (in the case of radioactive probes) or scanned (in the case of non-radioactive probes) to detect the location of the labeled probe on the membrane.

The position of the labeled probe on the membrane corresponds to the location of the specific DNA sequence within the original DNA sample. Southern blotting is a powerful tool for identifying and characterizing specific DNA sequences, such as those associated with genetic diseases or gene regulation.

A hair follicle is a part of the human skin from which hair grows. It is a complex organ that consists of several layers, including an outer root sheath, inner root sheath, and matrix. The hair follicle is located in the dermis, the second layer of the skin, and is surrounded by sebaceous glands and erector pili muscles.

The hair growth cycle includes three phases: anagen (growth phase), catagen (transitional phase), and telogen (resting phase). During the anagen phase, cells in the matrix divide rapidly to produce new hair fibers that grow out of the follicle. The hair fiber is made up of a protein called keratin, which also makes up the outer layers of the skin and nails.

Hair follicles are important for various biological functions, including thermoregulation, sensory perception, and social communication. They also play a role in wound healing and can serve as a source of stem cells that can differentiate into other cell types.

Animal testing alternatives, also known as alternative methods or replacement methods, refer to scientific techniques that can be used to replace the use of animals in research and testing. These methods aim to achieve the same scientific objectives while avoiding harm to animals. There are several categories of animal testing alternatives:

1. In vitro (test tube or cell culture) methods: These methods involve growing cells or tissues in a laboratory setting, outside of a living organism. They can be used to study the effects of chemicals, drugs, and other substances on specific cell types or tissues.
2. Computer modeling and simulation: Advanced computer programs and algorithms can be used to model biological systems and predict how they will respond to various stimuli. These methods can help researchers understand complex biological processes without using animals.
3. In silico (using computer models) methods: These methods involve the use of computational tools and databases to predict the potential toxicity or other biological effects of chemicals, drugs, and other substances. They can be used to identify potential hazards and prioritize further testing.
4. Microdosing: This method involves giving human volunteers very small doses of a drug or chemical, followed by careful monitoring to assess its safety and pharmacological properties. This approach can provide valuable information while minimizing the use of animals.
5. Tissue engineering: Scientists can create functional tissue constructs using cells, scaffolds, and bioreactors. These engineered tissues can be used to study the effects of drugs, chemicals, and other substances on human tissues without using animals.
6. Human-based approaches: These methods involve the use of human volunteers, donated tissues, or cells obtained from consenting adults. Examples include microdosing, organ-on-a-chip technology, and the use of human cell lines in laboratory experiments.

These animal testing alternatives can help reduce the number of animals used in research and testing, refine experimental procedures to minimize suffering, and replace the use of animals with non-animal methods whenever possible.

Paired box (PAX) transcription factors are a group of proteins that regulate gene expression during embryonic development and in some adult tissues. They are characterized by the presence of a paired box domain, a conserved DNA-binding motif that recognizes specific DNA sequences. PAX proteins play crucial roles in various developmental processes, such as the formation of the nervous system, eyes, and pancreas. Dysregulation of PAX genes has been implicated in several human diseases, including cancer.

Hepatocyte Nuclear Factor 3-beta (HNF-3β, also known as FOXA3) is a transcription factor that plays crucial roles in the development and function of various organs, including the liver, pancreas, and kidneys. It belongs to the forkhead box (FOX) family of proteins, which are characterized by a conserved DNA-binding domain known as the forkhead box or winged helix domain.

In the liver, HNF-3β is essential for the differentiation and maintenance of hepatocytes, the primary functional cells of the liver. It regulates the expression of several genes involved in liver-specific functions such as glucose metabolism, bile acid synthesis, and detoxification.

HNF-3β also has important roles in the pancreas, where it helps regulate the development and function of insulin-producing beta cells. In the kidneys, HNF-3β is involved in the differentiation and maintenance of the nephron, the functional unit responsible for filtering blood and maintaining water and electrolyte balance.

Mutations in the gene encoding HNF-3β have been associated with several genetic disorders, including maturity-onset diabetes of the young (MODY) and renal cysts and diabetes syndrome (RCAD).

Chromatin assembly and disassembly refer to the processes by which chromatin, the complex of DNA, histone proteins, and other molecules that make up chromosomes, is organized within the nucleus of a eukaryotic cell.

Chromatin assembly refers to the process by which DNA wraps around histone proteins to form nucleosomes, which are then packed together to form higher-order structures. This process is essential for compacting the vast amount of genetic material contained within the cell nucleus and for regulating gene expression. Chromatin assembly is mediated by a variety of protein complexes, including the histone chaperones and ATP-dependent chromatin remodeling enzymes.

Chromatin disassembly, on the other hand, refers to the process by which these higher-order structures are disassembled during cell division, allowing for the equal distribution of genetic material to daughter cells. This process is mediated by phosphorylation of histone proteins by kinases, which leads to the dissociation of nucleosomes and the decondensation of chromatin.

Both Chromatin assembly and disassembly are dynamic and highly regulated processes that play crucial roles in the maintenance of genome stability and the regulation of gene expression.

Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.

Retroviridae is a family of viruses that includes human immunodeficiency virus (HIV) and other viruses that primarily use RNA as their genetic material. The name "retrovirus" comes from the fact that these viruses reverse transcribe their RNA genome into DNA, which then becomes integrated into the host cell's genome. This is a unique characteristic of retroviruses, as most other viruses use DNA as their genetic material.

Retroviruses can cause a variety of diseases in animals and humans, including cancer, neurological disorders, and immunodeficiency syndromes like AIDS. They have a lipid membrane envelope that contains glycoprotein spikes, which allow them to attach to and enter host cells. Once inside the host cell, the viral RNA is reverse transcribed into DNA by the enzyme reverse transcriptase, which is then integrated into the host genome by the enzyme integrase.

Retroviruses can remain dormant in the host genome for extended periods of time, and may be reactivated under certain conditions to produce new viral particles. This ability to integrate into the host genome has also made retroviruses useful tools in molecular biology, where they are used as vectors for gene therapy and other genetic manipulations.

A cell line that is derived from tumor cells and has been adapted to grow in culture. These cell lines are often used in research to study the characteristics of cancer cells, including their growth patterns, genetic changes, and responses to various treatments. They can be established from many different types of tumors, such as carcinomas, sarcomas, and leukemias. Once established, these cell lines can be grown and maintained indefinitely in the laboratory, allowing researchers to conduct experiments and studies that would not be feasible using primary tumor cells. It is important to note that tumor cell lines may not always accurately represent the behavior of the original tumor, as they can undergo genetic changes during their time in culture.

The Primitive Streak is a transient structure that forms in the epiblast (the outermost layer of cells) of a developing embryo during gastrulation, which is a critical phase of embryonic development in many animals, including humans. In human embryos, this process starts around 14-16 days after fertilization.

The Primitive Streak is the site of important events that establish the three primary germ layers of the developing embryo: the ectoderm, mesoderm, and endoderm. These germ layers give rise to all the different cell types and tissues in the body. The Primitive Streak itself is formed by a narrow band of cells that migrate inward from the epiblast, creating a linear groove on the surface of the embryo.

As gastrulation proceeds, cells continue to move through the Primitive Streak, undergoing an epithelial-to-mesenchymal transition (EMT) and differentiating into various cell types that will form the mesoderm and endoderm. The ectoderm remains on the exterior of the embryo and eventually forms the skin and nervous system.

The Primitive Streak is a crucial structure in early human development, as its formation and subsequent events set the stage for proper body plan establishment and organogenesis. Any abnormalities during this process can lead to severe birth defects or developmental disorders.

Gene transfer techniques, also known as gene therapy, refer to medical procedures where genetic material is introduced into an individual's cells or tissues to treat or prevent diseases. This can be achieved through various methods:

1. **Viral Vectors**: The most common method uses modified viruses, such as adenoviruses, retroviruses, or lentiviruses, to carry the therapeutic gene into the target cells. The virus infects the cell and inserts the new gene into the cell's DNA.

2. **Non-Viral Vectors**: These include methods like electroporation (using electric fields to create pores in the cell membrane), gene guns (shooting gold particles coated with DNA into cells), or liposomes (tiny fatty bubbles that can enclose DNA).

3. **Direct Injection**: In some cases, the therapeutic gene can be directly injected into a specific tissue or organ.

The goal of gene transfer techniques is to supplement or replace a faulty gene with a healthy one, thereby correcting the genetic disorder. However, these techniques are still largely experimental and have their own set of challenges, including potential immune responses, issues with accurate targeting, and risks of mutations or cancer development.

Myoblasts are immature cells that later develop into muscle cells (also known as myocytes). Cardiac myoblasts, therefore, are the immature cells that will specialize and develop into cardiac muscle cells. These cells play a crucial role in the growth, repair, and regeneration of heart muscles. In adults, however, the ability of these cells to regenerate damaged heart muscle tissue is limited. Recent research has focused on the potential use of cardiac myoblasts in cell-based therapies for various heart conditions, such as heart failure and myocardial infarction (heart attack).

Integrases are enzymes that are responsible for the integration of genetic material into a host's DNA. In particular, integrases play a crucial role in the life cycle of retroviruses, such as HIV (Human Immunodeficiency Virus). These viruses have an RNA genome, which must be reverse-transcribed into DNA before it can be integrated into the host's chromosomal DNA.

The integrase enzyme, encoded by the virus's pol gene, is responsible for this critical step in the retroviral replication cycle. It mediates the cutting and pasting of the viral cDNA into a specific site within the host cell's genome, leading to the formation of a provirus. This provirus can then be transcribed and translated by the host cell's machinery, resulting in the production of new virus particles.

Integrase inhibitors are an important class of antiretroviral drugs used in the treatment of HIV infection. They work by blocking the activity of the integrase enzyme, thereby preventing the integration of viral DNA into the host genome and halting the replication of the virus.

Up-regulation is a term used in molecular biology and medicine to describe an increase in the expression or activity of a gene, protein, or receptor in response to a stimulus. This can occur through various mechanisms such as increased transcription, translation, or reduced degradation of the molecule. Up-regulation can have important functional consequences, for example, enhancing the sensitivity or response of a cell to a hormone, neurotransmitter, or drug. It is a normal physiological process that can also be induced by disease or pharmacological interventions.

Fibroblast Growth Factors (FGFs) are a family of growth factors that play crucial roles in various biological processes, including cell survival, proliferation, migration, and differentiation. They bind to specific tyrosine kinase receptors (FGFRs) on the cell surface, leading to intracellular signaling cascades that regulate gene expression and downstream cellular responses. FGFs are involved in embryonic development, tissue repair, and angiogenesis (the formation of new blood vessels). There are at least 22 distinct FGFs identified in humans, each with unique functions and patterns of expression. Some FGFs, like FGF1 and FGF2, have mitogenic effects on fibroblasts and other cell types, while others, such as FGF7 and FGF10, are essential for epithelial-mesenchymal interactions during organ development. Dysregulation of FGF signaling has been implicated in various pathological conditions, including cancer, fibrosis, and developmental disorders.

Methylation, in the context of genetics and epigenetics, refers to the addition of a methyl group (CH3) to a molecule, usually to the nitrogenous base of DNA or to the side chain of amino acids in proteins. In DNA methylation, this process typically occurs at the 5-carbon position of cytosine residues that precede guanine residues (CpG sites) and is catalyzed by enzymes called DNA methyltransferases (DNMTs).

DNA methylation plays a crucial role in regulating gene expression, genomic imprinting, X-chromosome inactivation, and suppression of repetitive elements. Hypermethylation or hypomethylation of specific genes can lead to altered gene expression patterns, which have been associated with various human diseases, including cancer.

In summary, methylation is a fundamental epigenetic modification that influences genomic stability, gene regulation, and cellular function by introducing methyl groups to DNA or proteins.

Epigenomics is the study of the epigenome, which refers to all of the chemical modifications and protein interactions that occur on top of a person's genetic material (DNA). These modifications do not change the underlying DNA sequence but can affect gene expression, or how much a particular gene is turned on or off.

Examples of epigenetic modifications include DNA methylation, histone modification, and non-coding RNA molecules. These modifications can be influenced by various factors such as age, environment, lifestyle, and disease state. Epigenomic changes have been implicated in the development and progression of many diseases, including cancer, and are an active area of research in molecular biology and genomics.

Cord blood stem cell transplantation is a medical procedure that involves the infusion of stem cells derived from the umbilical cord blood into a patient. These stem cells, specifically hematopoietic stem cells, have the ability to differentiate into various types of blood cells, including red and white blood cells and platelets.

Cord blood stem cell transplantation is often used as a treatment for patients with various malignant and non-malignant disorders, such as leukemia, lymphoma, sickle cell disease, and metabolic disorders. The procedure involves collecting cord blood from the umbilical cord and placenta after the birth of a baby, processing and testing it for compatibility with the recipient's immune system, and then infusing it into the patient through a vein in a process similar to a blood transfusion.

The advantages of using cord blood stem cells include their availability, low risk of transmission of infectious diseases, and reduced risk of graft-versus-host disease compared to other sources of hematopoietic stem cells, such as bone marrow or peripheral blood. However, the number of stem cells in a cord blood unit is generally lower than that found in bone marrow or peripheral blood, which can limit its use in some patients, particularly adults.

Overall, cord blood stem cell transplantation is an important and promising area of regenerative medicine, offering hope for patients with a wide range of disorders.

Adipogenesis is the process by which precursor cells differentiate into mature adipocytes, or fat cells. This complex biological process involves a series of molecular and cellular events that are regulated by various genetic and epigenetic factors.

During adipogenesis, preadipocytes undergo a series of changes that include cell cycle arrest, morphological alterations, and the expression of specific genes that are involved in lipid metabolism and insulin sensitivity. These changes ultimately result in the formation of mature adipocytes that are capable of storing energy in the form of lipids.

Abnormalities in adipogenesis have been linked to various health conditions, including obesity, type 2 diabetes, and metabolic syndrome. Understanding the molecular mechanisms that regulate adipogenesis is an active area of research, as it may lead to the development of new therapies for these and other related diseases.

Wnt3 protein is a member of the Wnt family of signaling proteins, which are secreted signaling molecules that play crucial roles in embryonic development and tissue homeostasis in adults. Specifically, Wnt3 is involved in the regulation of cell fate decisions, proliferation, and differentiation during embryogenesis. It binds to receptors on the target cells and activates a signaling pathway known as the canonical Wnt pathway, leading to the stabilization and nuclear accumulation of β-catenin, which then interacts with transcription factors to regulate gene expression. Defects in Wnt3 have been implicated in various developmental disorders, including some forms of congenital scoliosis and spina bifida.

Cadherins are a type of cell adhesion molecule that play a crucial role in the development and maintenance of intercellular junctions. They are transmembrane proteins that mediate calcium-dependent homophilic binding between adjacent cells, meaning that they bind to identical cadherin molecules on neighboring cells.

There are several types of cadherins, including classical cadherins, desmosomal cadherins, and protocadherins, each with distinct functions and localization in tissues. Classical cadherins, also known as type I cadherins, are the most well-studied and are essential for the formation of adherens junctions, which help to maintain cell-to-cell contact and tissue architecture.

Desmosomal cadherins, on the other hand, are critical for the formation and maintenance of desmosomes, which are specialized intercellular junctions that provide mechanical strength and stability to tissues. Protocadherins are a diverse family of cadherin-related proteins that have been implicated in various developmental processes, including neuronal connectivity and tissue patterning.

Mutations in cadherin genes have been associated with several human diseases, including cancer, neurological disorders, and heart defects. Therefore, understanding the structure, function, and regulation of cadherins is essential for elucidating their roles in health and disease.

Gene deletion is a type of mutation where a segment of DNA, containing one or more genes, is permanently lost or removed from a chromosome. This can occur due to various genetic mechanisms such as homologous recombination, non-homologous end joining, or other types of genomic rearrangements.

The deletion of a gene can have varying effects on the organism, depending on the function of the deleted gene and its importance for normal physiological processes. If the deleted gene is essential for survival, the deletion may result in embryonic lethality or developmental abnormalities. However, if the gene is non-essential or has redundant functions, the deletion may not have any noticeable effects on the organism's phenotype.

Gene deletions can also be used as a tool in genetic research to study the function of specific genes and their role in various biological processes. For example, researchers may use gene deletion techniques to create genetically modified animal models to investigate the impact of gene deletion on disease progression or development.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

A fetus is the developing offspring in a mammal, from the end of the embryonic period (approximately 8 weeks after fertilization in humans) until birth. In humans, the fetal stage of development starts from the eleventh week of pregnancy and continues until childbirth, which is termed as full-term pregnancy at around 37 to 40 weeks of gestation. During this time, the organ systems become fully developed and the body grows in size. The fetus is surrounded by the amniotic fluid within the amniotic sac and is connected to the placenta via the umbilical cord, through which it receives nutrients and oxygen from the mother. Regular prenatal care is essential during this period to monitor the growth and development of the fetus and ensure a healthy pregnancy and delivery.

A transplantation chimera is a rare medical condition that occurs after an organ or tissue transplant, where the recipient's body accepts and integrates the donor's cells or tissues to such an extent that the two sets of DNA coexist and function together. This phenomenon can lead to the presence of two different genetic profiles in one individual.

In some cases, this may result in the development of donor-derived cells or organs within the recipient's body, which can express the donor's unique genetic traits. Transplantation chimerism is more commonly observed in bone marrow transplants, where the donor's immune cells can repopulate and establish themselves within the recipient's bone marrow and bloodstream.

It is important to note that while transplantation chimerism can be beneficial for the success of the transplant, it may also pose some risks, such as an increased likelihood of developing graft-versus-host disease (GVHD), where the donor's immune cells attack the recipient's tissues.

Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.

Embryo disposition is the term used to describe the process of determining what will be done with embryos that were created through in vitro fertilization (IVF) and are no longer needed or wanted by the individuals who produced them. This can include options such as donating them to other couples or individuals who are trying to conceive, donating them for research purposes, storing them for potential future use, or discarding them. The decision about embryo disposition is often a complex and emotional one, and it may involve ethical, legal, and religious considerations. It is typically made by the individuals who produced the embryos, in consultation with their healthcare provider and/or a mental health professional. In some cases, courts or other legal authorities may become involved in the decision-making process.

STAT3 (Signal Transducer and Activator of Transcription 3) is a transcription factor protein that plays a crucial role in signal transduction and gene regulation. It is activated through phosphorylation by various cytokines and growth factors, which leads to its dimerization, nuclear translocation, and binding to specific DNA sequences. Once bound to the DNA, STAT3 regulates the expression of target genes involved in various cellular processes such as proliferation, differentiation, survival, and angiogenesis. Dysregulation of STAT3 has been implicated in several diseases, including cancer, autoimmune disorders, and inflammatory conditions.

The "beginning of human life" is a term that is often used in the context of medical ethics, particularly in discussions about issues such as abortion and stem cell research. However, there is no universally accepted medical definition of this term, as it is also influenced by philosophical, religious, and legal considerations.

From a biological perspective, human life begins at fertilization, when a sperm cell successfully penetrates and fuses with an egg cell to form a zygote. This single cell contains the complete genetic makeup of the future individual and has the potential to develop into a fully formed human being, given the right conditions.

However, some people argue that personhood or moral status does not begin until later stages of development, such as at implantation, when the zygote attaches to the uterine wall and begins to receive nutrients from the mother's body, or at viability, when the fetus can survive outside the womb with medical assistance.

Ultimately, the definition of "beginning of human life" is a complex and controversial issue that depends on one's values and beliefs. It is important to recognize and respect the diversity of opinions on this matter and engage in thoughtful and respectful dialogue about its implications for medical practice and policy.

Transforming Growth Factor-beta (TGF-β) is a type of cytokine, which is a cell signaling protein involved in the regulation of various cellular processes, including cell growth, differentiation, and apoptosis (programmed cell death). TGF-β plays a critical role in embryonic development, tissue homeostasis, and wound healing. It also has been implicated in several pathological conditions such as fibrosis, cancer, and autoimmune diseases.

TGF-β exists in multiple isoforms (TGF-β1, TGF-β2, and TGF-β3) that are produced by many different cell types, including immune cells, epithelial cells, and fibroblasts. The protein is synthesized as a precursor molecule, which is cleaved to release the active TGF-β peptide. Once activated, TGF-β binds to its receptors on the cell surface, leading to the activation of intracellular signaling pathways that regulate gene expression and cell behavior.

In summary, Transforming Growth Factor-beta (TGF-β) is a multifunctional cytokine involved in various cellular processes, including cell growth, differentiation, apoptosis, embryonic development, tissue homeostasis, and wound healing. It has been implicated in several pathological conditions such as fibrosis, cancer, and autoimmune diseases.

Graft survival, in medical terms, refers to the success of a transplanted tissue or organ in continuing to function and integrate with the recipient's body over time. It is the opposite of graft rejection, which occurs when the recipient's immune system recognizes the transplanted tissue as foreign and attacks it, leading to its failure.

Graft survival depends on various factors, including the compatibility between the donor and recipient, the type and location of the graft, the use of immunosuppressive drugs to prevent rejection, and the overall health of the recipient. A successful graft survival implies that the transplanted tissue or organ has been accepted by the recipient's body and is functioning properly, providing the necessary physiological support for the recipient's survival and improved quality of life.

Bone marrow is the spongy tissue found inside certain bones in the body, such as the hips, thighs, and vertebrae. It is responsible for producing blood-forming cells, including red blood cells, white blood cells, and platelets. There are two types of bone marrow: red marrow, which is involved in blood cell production, and yellow marrow, which contains fatty tissue.

Red bone marrow contains hematopoietic stem cells, which can differentiate into various types of blood cells. These stem cells continuously divide and mature to produce new blood cells that are released into the circulation. Red blood cells carry oxygen throughout the body, white blood cells help fight infections, and platelets play a crucial role in blood clotting.

Bone marrow also serves as a site for immune cell development and maturation. It contains various types of immune cells, such as lymphocytes, macrophages, and dendritic cells, which help protect the body against infections and diseases.

Abnormalities in bone marrow function can lead to several medical conditions, including anemia, leukopenia, thrombocytopenia, and various types of cancer, such as leukemia and multiple myeloma. Bone marrow aspiration and biopsy are common diagnostic procedures used to evaluate bone marrow health and function.

The cellular microenvironment refers to the sum of all physical and biochemical factors in the immediate vicinity of a cell that influence its behavior and function. This includes elements such as:

1. Extracellular matrix (ECM): The non-cellular component that provides structural support, anchorage, and biochemical cues to cells through various molecules like collagens, fibronectin, and laminins.
2. Soluble factors: These include growth factors, hormones, cytokines, and chemokines that bind to cell surface receptors and modulate cellular responses.
3. Neighboring cells: The types and states of nearby cells can significantly impact a cell's behavior through direct contact, paracrine signaling, or competition for resources.
4. Physical conditions: Variables such as temperature, pH, oxygen tension, and mechanical stresses (e.g., stiffness, strain) also contribute to the cellular microenvironment.
5. Biochemical gradients: Concentration gradients of molecules within the ECM or surrounding fluid can guide cell migration, differentiation, and other responses.

Collectively, these factors interact to create a complex and dynamic milieu that regulates various aspects of cellular physiology, including proliferation, differentiation, survival, and motility. Understanding the cellular microenvironment is crucial for developing effective therapies and tissue engineering strategies in regenerative medicine and cancer treatment.

Neoplastic cell transformation is a process in which a normal cell undergoes genetic alterations that cause it to become cancerous or malignant. This process involves changes in the cell's DNA that result in uncontrolled cell growth and division, loss of contact inhibition, and the ability to invade surrounding tissues and metastasize (spread) to other parts of the body.

Neoplastic transformation can occur as a result of various factors, including genetic mutations, exposure to carcinogens, viral infections, chronic inflammation, and aging. These changes can lead to the activation of oncogenes or the inactivation of tumor suppressor genes, which regulate cell growth and division.

The transformation of normal cells into cancerous cells is a complex and multi-step process that involves multiple genetic and epigenetic alterations. It is characterized by several hallmarks, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, enabling replicative immortality, induction of angiogenesis, activation of invasion and metastasis, reprogramming of energy metabolism, and evading immune destruction.

Neoplastic cell transformation is a fundamental concept in cancer biology and is critical for understanding the molecular mechanisms underlying cancer development and progression. It also has important implications for cancer diagnosis, prognosis, and treatment, as identifying the specific genetic alterations that underlie neoplastic transformation can help guide targeted therapies and personalized medicine approaches.

In medical terms, the heart is a muscular organ located in the thoracic cavity that functions as a pump to circulate blood throughout the body. It's responsible for delivering oxygen and nutrients to the tissues and removing carbon dioxide and other wastes. The human heart is divided into four chambers: two atria on the top and two ventricles on the bottom. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it out to the rest of the body. The heart's rhythmic contractions and relaxations are regulated by a complex electrical conduction system.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

LIM-homeodomain proteins are a family of transcription factors that contain both LIM domains and homeodomains. LIM domains are cysteine-rich motifs that function in protein-protein interactions, often mediating the formation of multimeric complexes. Homeodomains are DNA-binding domains that recognize and bind to specific DNA sequences, thereby regulating gene transcription.

LIM-homeodomain proteins play important roles in various developmental processes, including cell fate determination, differentiation, and migration. They have been implicated in the regulation of muscle, nerve, and cardiovascular development, as well as in cancer and other diseases. Some examples of LIM-homeodomain proteins include LMX1A, LHX2, and ISL1.

These proteins are characterized by the presence of two LIM domains at the N-terminus and a homeodomain at the C-terminus. The LIM domains are involved in protein-protein interactions, while the homeodomain is responsible for DNA binding and transcriptional regulation. Some LIM-homeodomain proteins also contain other functional domains, such as zinc fingers or leucine zippers, which contribute to their diverse functions.

Overall, LIM-homeodomain proteins are important regulators of gene expression and play critical roles in various developmental and disease processes.

Bone marrow transplantation (BMT) is a medical procedure in which damaged or destroyed bone marrow is replaced with healthy bone marrow from a donor. Bone marrow is the spongy tissue inside bones that produces blood cells. The main types of BMT are autologous, allogeneic, and umbilical cord blood transplantation.

In autologous BMT, the patient's own bone marrow is used for the transplant. This type of BMT is often used in patients with lymphoma or multiple myeloma who have undergone high-dose chemotherapy or radiation therapy to destroy their cancerous bone marrow.

In allogeneic BMT, bone marrow from a genetically matched donor is used for the transplant. This type of BMT is often used in patients with leukemia, lymphoma, or other blood disorders who have failed other treatments.

Umbilical cord blood transplantation involves using stem cells from umbilical cord blood as a source of healthy bone marrow. This type of BMT is often used in children and adults who do not have a matched donor for allogeneic BMT.

The process of BMT typically involves several steps, including harvesting the bone marrow or stem cells from the donor, conditioning the patient's body to receive the new bone marrow or stem cells, transplanting the new bone marrow or stem cells into the patient's body, and monitoring the patient for signs of engraftment and complications.

BMT is a complex and potentially risky procedure that requires careful planning, preparation, and follow-up care. However, it can be a life-saving treatment for many patients with blood disorders or cancer.

CD24 is a cell surface glycoprotein that serves as a marker for B cells at various stages of development and differentiation. It is also expressed on the surface of certain other cell types, including neutrophils and some cancer cells. Antigens are substances that can stimulate an immune response and are recognized as foreign by the body's immune system. CD24 is not typically referred to as an antigen itself, but it can be used as a target for immunotherapy in certain types of cancer. In this context, monoclonal antibodies or other immune-based therapies may be developed to specifically recognize and bind to CD24 on the surface of cancer cells, with the goal of triggering an immune response against the cancer cells.

Proto-oncogene proteins are normal cellular proteins that play crucial roles in various cellular processes, such as signal transduction, cell cycle regulation, and apoptosis (programmed cell death). They are involved in the regulation of cell growth, differentiation, and survival under physiological conditions.

When proto-oncogene proteins undergo mutations or aberrations in their expression levels, they can transform into oncogenic forms, leading to uncontrolled cell growth and division. These altered proteins are then referred to as oncogene products or oncoproteins. Oncogenic mutations can occur due to various factors, including genetic predisposition, environmental exposures, and aging.

Examples of proto-oncogene proteins include:

1. Ras proteins: Involved in signal transduction pathways that regulate cell growth and differentiation. Activating mutations in Ras genes are found in various human cancers.
2. Myc proteins: Regulate gene expression related to cell cycle progression, apoptosis, and metabolism. Overexpression of Myc proteins is associated with several types of cancer.
3. EGFR (Epidermal Growth Factor Receptor): A transmembrane receptor tyrosine kinase that regulates cell proliferation, survival, and differentiation. Mutations or overexpression of EGFR are linked to various malignancies, such as lung cancer and glioblastoma.
4. Src family kinases: Intracellular tyrosine kinases that regulate signal transduction pathways involved in cell proliferation, survival, and migration. Dysregulation of Src family kinases is implicated in several types of cancer.
5. Abl kinases: Cytoplasmic tyrosine kinases that regulate various cellular processes, including cell growth, differentiation, and stress responses. Aberrant activation of Abl kinases, as seen in chronic myelogenous leukemia (CML), leads to uncontrolled cell proliferation.

Understanding the roles of proto-oncogene proteins and their dysregulation in cancer development is essential for developing targeted cancer therapies that aim to inhibit or modulate these aberrant signaling pathways.

Proteoglycans are complex, highly negatively charged macromolecules that are composed of a core protein covalently linked to one or more glycosaminoglycan (GAG) chains. They are a major component of the extracellular matrix (ECM) and play crucial roles in various biological processes, including cell signaling, regulation of growth factor activity, and maintenance of tissue structure and function.

The GAG chains, which can vary in length and composition, are long, unbranched polysaccharides that are composed of repeating disaccharide units containing a hexuronic acid (either glucuronic or iduronic acid) and a hexosamine (either N-acetylglucosamine or N-acetylgalactosamine). These GAG chains can be sulfated to varying degrees, which contributes to the negative charge of proteoglycans.

Proteoglycans are classified into four major groups based on their core protein structure and GAG composition: heparan sulfate/heparin proteoglycans, chondroitin/dermatan sulfate proteoglycans, keratan sulfate proteoglycans, and hyaluronan-binding proteoglycans. Each group has distinct functions and is found in specific tissues and cell types.

In summary, proteoglycans are complex macromolecules composed of a core protein and one or more GAG chains that play important roles in the ECM and various biological processes, including cell signaling, growth factor regulation, and tissue structure maintenance.

CpG islands are defined as short stretches of DNA that are characterized by a higher than expected frequency of CpG dinucleotides. A dinucleotide is a pair of adjacent nucleotides, and in the case of CpG, C represents cytosine and G represents guanine. These islands are typically found in the promoter regions of genes, where they play important roles in regulating gene expression.

Under normal circumstances, the cytosine residue in a CpG dinucleotide is often methylated, meaning that a methyl group (-CH3) is added to the cytosine base. However, in CpG islands, methylation is usually avoided, and these regions tend to be unmethylated. This has important implications for gene expression because methylation of CpG dinucleotides in promoter regions can lead to the silencing of genes.

CpG islands are also often targets for transcription factors, which bind to specific DNA sequences and help regulate gene expression. The unmethylated state of CpG islands is thought to be important for maintaining the accessibility of these regions to transcription factors and other regulatory proteins.

Abnormal methylation patterns in CpG islands have been associated with various diseases, including cancer. In many cancers, CpG islands become aberrantly methylated, leading to the silencing of tumor suppressor genes and contributing to the development and progression of the disease.

Paracrine communication is a form of cell-to-cell communication in which a cell releases a signaling molecule, known as a paracrine factor, that acts on nearby cells within the local microenvironment. This type of communication allows for the coordination and regulation of various cellular processes, including growth, differentiation, and survival.

Paracrine factors can be released from a cell through various mechanisms, such as exocytosis or diffusion through the extracellular matrix. Once released, these factors bind to specific receptors on the surface of nearby cells, triggering intracellular signaling pathways that lead to changes in gene expression and cell behavior.

Paracrine communication is an important mechanism for maintaining tissue homeostasis and coordinating responses to injury or disease. For example, during wound healing, paracrine signals released by immune cells can recruit other cells to the site of injury and stimulate their proliferation and differentiation to promote tissue repair.

It's worth noting that paracrine communication should be distinguished from autocrine signaling, where a cell releases a signaling molecule that binds back to its own receptors, and endocrine signaling, where a hormone is released into the bloodstream and travels to distant target cells.

In situ hybridization (ISH) is a molecular biology technique used to detect and localize specific nucleic acid sequences, such as DNA or RNA, within cells or tissues. This technique involves the use of a labeled probe that is complementary to the target nucleic acid sequence. The probe can be labeled with various types of markers, including radioisotopes, fluorescent dyes, or enzymes.

During the ISH procedure, the labeled probe is hybridized to the target nucleic acid sequence in situ, meaning that the hybridization occurs within the intact cells or tissues. After washing away unbound probe, the location of the labeled probe can be visualized using various methods depending on the type of label used.

In situ hybridization has a wide range of applications in both research and diagnostic settings, including the detection of gene expression patterns, identification of viral infections, and diagnosis of genetic disorders.

The myocardium is the middle layer of the heart wall, composed of specialized cardiac muscle cells that are responsible for pumping blood throughout the body. It forms the thickest part of the heart wall and is divided into two sections: the left ventricle, which pumps oxygenated blood to the rest of the body, and the right ventricle, which pumps deoxygenated blood to the lungs.

The myocardium contains several types of cells, including cardiac muscle fibers, connective tissue, nerves, and blood vessels. The muscle fibers are arranged in a highly organized pattern that allows them to contract in a coordinated manner, generating the force necessary to pump blood through the heart and circulatory system.

Damage to the myocardium can occur due to various factors such as ischemia (reduced blood flow), infection, inflammation, or genetic disorders. This damage can lead to several cardiac conditions, including heart failure, arrhythmias, and cardiomyopathy.

T-box domain proteins are a family of transcription factors that share a highly conserved DNA-binding domain, known as the T-box. The T-box domain is a DNA-binding motif that specifically recognizes and binds to T-box binding elements (TBEs) in the regulatory regions of target genes. These proteins play crucial roles during embryonic development, particularly in the formation of specific tissues and organs, such as the heart, limbs, and brain. Mutations in T-box domain proteins can lead to various congenital defects and developmental disorders. Some examples of T-box domain proteins include TBX1, TBX5, and TBX20.

The hematopoietic system is the group of tissues and organs in the body that are responsible for the production and maturation of blood cells. These include:

1. Bone marrow: The spongy tissue inside some bones, like the hips and thighs, where most blood cells are produced.
2. Spleen: An organ located in the upper left part of the abdomen that filters the blood, stores red and white blood cells, and removes waste products.
3. Liver: A large organ in the upper right part of the abdomen that filters blood, detoxifies harmful substances, produces bile to aid in digestion, and stores some nutrients like glucose and iron.
4. Lymph nodes: Small glands found throughout the body, especially in the neck, armpits, and groin, that filter lymph fluid and help fight infection.
5. Thymus: A small organ located in the chest, between the lungs, that helps develop T-cells, a type of white blood cell that fights infection.

The hematopoietic system produces three main types of cells:

1. Red blood cells (erythrocytes): Carry oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.
2. White blood cells (leukocytes): Help fight infection and are part of the body's immune system.
3. Platelets (thrombocytes): Small cell fragments that help form blood clots to stop bleeding.

Disorders of the hematopoietic system can lead to conditions such as anemia, leukemia, and lymphoma.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

The brainstem is the lower part of the brain that connects to the spinal cord. It consists of the midbrain, pons, and medulla oblongata. The brainstem controls many vital functions such as heart rate, breathing, and blood pressure. It also serves as a relay center for sensory and motor information between the cerebral cortex and the rest of the body. Additionally, several cranial nerves originate from the brainstem, including those that control eye movements, facial movements, and hearing.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Telomerase is an enzyme that adds repetitive DNA sequences (telomeres) to the ends of chromosomes, which are lost during each cell division due to the incomplete replication of the ends of linear chromosomes. Telomerase is not actively present in most somatic cells, but it is highly expressed in germ cells and stem cells, allowing them to divide indefinitely. However, in many types of cancer cells, telomerase is abnormally activated, which leads to the maintenance or lengthening of telomeres, contributing to their unlimited replicative potential and tumorigenesis.

Confocal microscopy is a powerful imaging technique used in medical and biological research to obtain high-resolution, contrast-rich images of thick samples. This super-resolution technology provides detailed visualization of cellular structures and processes at various depths within a specimen.

In confocal microscopy, a laser beam focused through a pinhole illuminates a small spot within the sample. The emitted fluorescence or reflected light from this spot is then collected by a detector, passing through a second pinhole that ensures only light from the focal plane reaches the detector. This process eliminates out-of-focus light, resulting in sharp images with improved contrast compared to conventional widefield microscopy.

By scanning the laser beam across the sample in a raster pattern and collecting fluorescence at each point, confocal microscopy generates optical sections of the specimen. These sections can be combined to create three-dimensional reconstructions, allowing researchers to study cellular architecture and interactions within complex tissues.

Confocal microscopy has numerous applications in medical research, including studying protein localization, tracking intracellular dynamics, analyzing cell morphology, and investigating disease mechanisms at the cellular level. Additionally, it is widely used in clinical settings for diagnostic purposes, such as analyzing skin lesions or detecting pathogens in patient samples.

The testis, also known as the testicle, is a male reproductive organ that is part of the endocrine system. It is located in the scrotum, outside of the abdominal cavity. The main function of the testis is to produce sperm and testosterone, the primary male sex hormone.

The testis is composed of many tiny tubules called seminiferous tubules, where sperm are produced. These tubules are surrounded by a network of blood vessels, nerves, and supportive tissues. The sperm then travel through a series of ducts to the epididymis, where they mature and become capable of fertilization.

Testosterone is produced in the Leydig cells, which are located in the interstitial tissue between the seminiferous tubules. Testosterone plays a crucial role in the development and maintenance of male secondary sexual characteristics, such as facial hair, deep voice, and muscle mass. It also supports sperm production and sexual function.

Abnormalities in testicular function can lead to infertility, hormonal imbalances, and other health problems. Regular self-examinations and medical check-ups are recommended for early detection and treatment of any potential issues.

The transcriptome refers to the complete set of RNA molecules, including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), and other non-coding RNAs, that are present in a cell or a population of cells at a given point in time. It reflects the genetic activity and provides information about which genes are being actively transcribed and to what extent. The transcriptome can vary under different conditions, such as during development, in response to environmental stimuli, or in various diseases, making it an important area of study in molecular biology and personalized medicine.

Cell transdifferentiation is a process in which one type of differentiated cell transforms into another type of differentiated cell, without going through the stage of pluripotent stem cells. This process involves a series of genetic and epigenetic changes that result in the activation of new genetic programs and repression of old ones, leading to the acquisition of a new cell identity.

Transdifferentiation is a rare event in nature, but it has been induced in the laboratory through various methods such as gene transfer, chemical treatment, or nuclear transplantation. This process has potential applications in regenerative medicine, tissue engineering, and disease modeling. However, it also raises ethical concerns related to the generation of chimeric organisms and the possibility of uncontrolled cell growth.

Polycomb Repressive Complex 1 (PRC1) is a protein complex that plays a crucial role in the epigenetic regulation of gene expression, primarily through the process of histone modification. It is associated with the maintenance of gene repression during development and differentiation. PRC1 facilitates the monoubiquitination of histone H2A at lysine 119 (H2AK119ub1), leading to chromatin compaction and transcriptional silencing. This complex is composed of several core subunits, including BMI1, RING1A/B, and one of the six PCGF proteins, which define different PRC1 variants. Dysregulation of PRC1 has been implicated in various human diseases, such as cancers and developmental disorders.

Bone Morphogenetic Protein 2 (BMP-2) is a growth factor that belongs to the transforming growth factor-beta (TGF-β) superfamily. It plays a crucial role in bone and cartilage formation, as well as in the regulation of wound healing and embryonic development. BMP-2 stimulates the differentiation of mesenchymal stem cells into osteoblasts, which are cells responsible for bone formation.

BMP-2 has been approved by the US Food and Drug Administration (FDA) as a medical device to promote bone growth in certain spinal fusion surgeries and in the treatment of open fractures that have not healed properly. It is usually administered in the form of a collagen sponge soaked with recombinant human BMP-2 protein, which is a laboratory-produced version of the natural protein.

While BMP-2 has shown promising results in some clinical applications, its use is not without risks and controversies. Some studies have reported adverse effects such as inflammation, ectopic bone formation, and increased rates of cancer, which have raised concerns about its safety and efficacy. Therefore, it is essential to weigh the benefits and risks of BMP-2 therapy on a case-by-case basis and under the guidance of a qualified healthcare professional.

Kanamycin Kinase is not a widely recognized medical term, but it is a concept from the field of microbiology. It refers to an enzyme produced by certain bacteria that catalyzes the phosphorylation of kanamycin, an aminoglycoside antibiotic. The phosphorylation of kanamycin inactivates its antibacterial activity, making it less effective against those bacteria that produce this kinase. This is one mechanism by which some bacteria develop resistance to antibiotics.

Embryo loss is a medical term that refers to the miscarriage or spontaneous abortion of an embryo, which is the developing offspring from the time of fertilization until the end of the eighth week of pregnancy. Embryo loss can occur at any point during this period and may be caused by various factors such as chromosomal abnormalities, maternal health issues, infections, environmental factors, or lifestyle habits.

Embryo loss is a common occurrence, with up to 30% of pregnancies ending in miscarriage, many of which happen before the woman even realizes she is pregnant. In most cases, embryo loss is a natural process that occurs when the body detects an abnormality or problem with the developing embryo and terminates the pregnancy to prevent further complications. However, recurrent embryo loss can be a sign of underlying medical issues and may require further evaluation and treatment.

'Rats, Nude' is not a standard medical term or condition. The term 'nude' in the context of laboratory animals like rats usually refers to a strain of rats that are hairless due to a genetic mutation. This can make them useful for studies involving skin disorders, wound healing, and other conditions where fur might interfere with observations or procedures. However, 'Rats, Nude' is not a recognized or established term in medical literature or taxonomy.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Hedgehog proteins are a group of signaling molecules that play crucial roles in the development and regulation of various biological processes in animals. They are named after the hedgehog mutant fruit flies, which have spiky bristles due to defects in this pathway. These proteins are involved in cell growth, differentiation, and tissue regeneration. They exert their effects by binding to specific receptors on the surface of target cells, leading to a cascade of intracellular signaling events that ultimately influence gene expression and cell behavior.

There are three main types of Hedgehog proteins in mammals: Sonic hedgehog (Shh), Indian hedgehog (Ihh), and Desert hedgehog (Dhh). These protecules undergo post-translational modifications, including cleavage and lipid modification, which are essential for their activity. Dysregulation of Hedgehog signaling has been implicated in various diseases, including cancer, developmental abnormalities, and degenerative disorders.

An animal model in medicine refers to the use of non-human animals in experiments to understand, predict, and test responses and effects of various biological and chemical interactions that may also occur in humans. These models are used when studying complex systems or processes that cannot be easily replicated or studied in human subjects, such as genetic manipulation or exposure to harmful substances. The choice of animal model depends on the specific research question being asked and the similarities between the animal's and human's biological and physiological responses. Examples of commonly used animal models include mice, rats, rabbits, guinea pigs, and non-human primates.

Organogenesis is the process of formation and development of organs during embryonic growth. It involves the complex interactions of cells, tissues, and signaling molecules that lead to the creation of specialized structures in the body. This process begins in the early stages of embryonic development, around week 4-8, and continues until birth. During organogenesis, the three primary germ layers (ectoderm, mesoderm, and endoderm) differentiate into various cell types and organize themselves into specific structures that will eventually form the functional organs of the body. Abnormalities in organogenesis can result in congenital disorders or birth defects.

Cellular aging, also known as cellular senescence, is a natural process that occurs as cells divide and grow older. Over time, cells accumulate damage to their DNA, proteins, and lipids due to various factors such as genetic mutations, oxidative stress, and epigenetic changes. This damage can impair the cell's ability to function properly and can lead to changes associated with aging, such as decreased tissue repair and regeneration, increased inflammation, and increased risk of age-related diseases.

Cellular aging is characterized by several features, including:

1. Shortened telomeres: Telomeres are the protective caps on the ends of chromosomes that shorten each time a cell divides. When telomeres become too short, the cell can no longer divide and becomes senescent or dies.
2. Epigenetic changes: Epigenetic modifications refer to chemical changes to DNA and histone proteins that affect gene expression without changing the underlying genetic code. As cells age, they accumulate epigenetic changes that can alter gene expression and contribute to cellular aging.
3. Oxidative stress: Reactive oxygen species (ROS) are byproducts of cellular metabolism that can damage DNA, proteins, and lipids. Accumulated ROS over time can lead to oxidative stress, which is associated with cellular aging.
4. Inflammation: Senescent cells produce pro-inflammatory cytokines, chemokines, and matrix metalloproteinases that contribute to a low-grade inflammation known as inflammaging. This chronic inflammation can lead to tissue damage and increase the risk of age-related diseases.
5. Genomic instability: DNA damage accumulates with age, leading to genomic instability and an increased risk of mutations and cancer.

Understanding cellular aging is crucial for developing interventions that can delay or prevent age-related diseases and improve healthy lifespan.

The limbus cornea, also known as the corneoscleral junction, is the border between the transparent cornea and the opaque sclera in the eye. It's a circular, narrow region that contains cells called limbal stem cells, which are essential for maintaining the health and clarity of the cornea. These stem cells continuously regenerate and differentiate into corneal epithelial cells, replacing the outermost layer of the cornea. Any damage or disorder in this area can lead to vision impairment or loss.

"Gene knock-in techniques" refer to a group of genetic engineering methods used in molecular biology to precisely insert or "knock-in" a specific gene or DNA sequence into a specific location within the genome of an organism. This is typically done using recombinant DNA technology and embryonic stem (ES) cells, although other techniques such as CRISPR-Cas9 can also be used.

The goal of gene knock-in techniques is to create a stable and heritable genetic modification in which the introduced gene is expressed at a normal level and in the correct spatial and temporal pattern. This allows researchers to study the function of individual genes, investigate gene regulation, model human diseases, and develop potential therapies for genetic disorders.

In general, gene knock-in techniques involve several steps: first, a targeting vector is constructed that contains the desired DNA sequence flanked by homologous regions that match the genomic locus where the insertion will occur. This vector is then introduced into ES cells, which are cultured and allowed to undergo homologous recombination with the endogenous genome. The resulting modified ES cells are selected for and characterized to confirm the correct integration of the DNA sequence. Finally, the modified ES cells are used to generate chimeric animals, which are then bred to produce offspring that carry the genetic modification in their germline.

Overall, gene knock-in techniques provide a powerful tool for studying gene function and developing new therapies for genetic diseases.

Cell engineering is a branch of biotechnology that involves the manipulation and modification of cells to achieve desired functions or characteristics. This can be accomplished through various techniques, including genetic engineering, gene editing, cell culturing, and tissue engineering. The goal of cell engineering may be to develop new therapies for diseases, create cells or tissues that can replace damaged ones in the body, or to better understand how cells function.

In genetic engineering, genes are introduced into cells using vectors such as plasmids or viruses. These genes can encode for specific proteins or enzymes that can help the cell perform a particular function, such as producing a therapeutic protein or breaking down a toxic substance. Gene editing techniques, such as CRISPR-Cas9, allow for precise editing of an organism's genome, enabling the correction of genetic mutations or the introduction of new traits.

Cell culturing involves growing cells in controlled conditions outside of the body, allowing researchers to study their behavior and properties. Tissue engineering combines cell engineering with materials science to create functional tissues or organs that can be used for transplantation or other medical applications.

Overall, cell engineering has the potential to revolutionize medicine by enabling the development of personalized therapies, regenerative medicine, and new treatments for a wide range of diseases and conditions.

Genetic models are theoretical frameworks used in genetics to describe and explain the inheritance patterns and genetic architecture of traits, diseases, or phenomena. These models are based on mathematical equations and statistical methods that incorporate information about gene frequencies, modes of inheritance, and the effects of environmental factors. They can be used to predict the probability of certain genetic outcomes, to understand the genetic basis of complex traits, and to inform medical management and treatment decisions.

There are several types of genetic models, including:

1. Mendelian models: These models describe the inheritance patterns of simple genetic traits that follow Mendel's laws of segregation and independent assortment. Examples include autosomal dominant, autosomal recessive, and X-linked inheritance.
2. Complex trait models: These models describe the inheritance patterns of complex traits that are influenced by multiple genes and environmental factors. Examples include heart disease, diabetes, and cancer.
3. Population genetics models: These models describe the distribution and frequency of genetic variants within populations over time. They can be used to study evolutionary processes, such as natural selection and genetic drift.
4. Quantitative genetics models: These models describe the relationship between genetic variation and phenotypic variation in continuous traits, such as height or IQ. They can be used to estimate heritability and to identify quantitative trait loci (QTLs) that contribute to trait variation.
5. Statistical genetics models: These models use statistical methods to analyze genetic data and infer the presence of genetic associations or linkage. They can be used to identify genetic risk factors for diseases or traits.

Overall, genetic models are essential tools in genetics research and medical genetics, as they allow researchers to make predictions about genetic outcomes, test hypotheses about the genetic basis of traits and diseases, and develop strategies for prevention, diagnosis, and treatment.

A drug combination refers to the use of two or more drugs in combination for the treatment of a single medical condition or disease. The rationale behind using drug combinations is to achieve a therapeutic effect that is superior to that obtained with any single agent alone, through various mechanisms such as:

* Complementary modes of action: When different drugs target different aspects of the disease process, their combined effects may be greater than either drug used alone.
* Synergistic interactions: In some cases, the combination of two or more drugs can result in a greater-than-additive effect, where the total response is greater than the sum of the individual responses to each drug.
* Antagonism of adverse effects: Sometimes, the use of one drug can mitigate the side effects of another, allowing for higher doses or longer durations of therapy.

Examples of drug combinations include:

* Highly active antiretroviral therapy (HAART) for HIV infection, which typically involves a combination of three or more antiretroviral drugs to suppress viral replication and prevent the development of drug resistance.
* Chemotherapy regimens for cancer treatment, where combinations of cytotoxic agents are used to target different stages of the cell cycle and increase the likelihood of tumor cell death.
* Fixed-dose combination products, such as those used in the treatment of hypertension or type 2 diabetes, which combine two or more active ingredients into a single formulation for ease of administration and improved adherence to therapy.

However, it's important to note that drug combinations can also increase the risk of adverse effects, drug-drug interactions, and medication errors. Therefore, careful consideration should be given to the selection of appropriate drugs, dosing regimens, and monitoring parameters when using drug combinations in clinical practice.

Blastomeres are early stage embryonic cells that result from the initial rounds of cell division in a fertilized egg, also known as a zygote. These cells are typically smaller and have a more simple organization compared to more mature cells. They are important for the normal development of the embryo and contribute to the formation of the blastocyst, which is an early stage embryonic structure that will eventually give rise to the fetus. The process of cell division that produces blastomeres is called cleavage.

A heterozygote is an individual who has inherited two different alleles (versions) of a particular gene, one from each parent. This means that the individual's genotype for that gene contains both a dominant and a recessive allele. The dominant allele will be expressed phenotypically (outwardly visible), while the recessive allele may or may not have any effect on the individual's observable traits, depending on the specific gene and its function. Heterozygotes are often represented as 'Aa', where 'A' is the dominant allele and 'a' is the recessive allele.

ICR (Institute of Cancer Research) is a strain of albino Swiss mice that are widely used in scientific research. They are an outbred strain, which means that they have been bred to maintain maximum genetic heterogeneity. However, it is also possible to find inbred strains of ICR mice, which are genetically identical individuals produced by many generations of brother-sister mating.

Inbred ICR mice are a specific type of ICR mouse that has been inbred for at least 20 generations. This means that they have a high degree of genetic uniformity and are essentially genetically identical to one another. Inbred strains of mice are often used in research because their genetic consistency makes them more reliable models for studying biological phenomena and testing new therapies or treatments.

It is important to note that while inbred ICR mice may be useful for certain types of research, they do not necessarily represent the genetic diversity found in human populations. Therefore, it is important to consider the limitations of using any animal model when interpreting research findings and applying them to human health.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Toxicity tests, also known as toxicity assays, are a set of procedures used to determine the harmful effects of various substances on living organisms, typically on cells, tissues, or whole animals. These tests measure the degree to which a substance can cause damage, inhibit normal functioning, or lead to death in exposed organisms.

Toxicity tests can be conducted in vitro (in a test tube or petri dish) using cell cultures or in vivo (in living organisms) using animals such as rats, mice, or rabbits. The results of these tests help researchers and regulators assess the potential risks associated with exposure to various chemicals, drugs, or environmental pollutants.

There are several types of toxicity tests, including:

1. Acute toxicity tests: These tests measure the immediate effects of a single exposure to a substance over a short period (usually 24 hours or less).
2. Chronic toxicity tests: These tests evaluate the long-term effects of repeated exposures to a substance over an extended period (weeks, months, or even years).
3. Genotoxicity tests: These tests determine whether a substance can damage DNA or cause mutations in genetic material.
4. Developmental and reproductive toxicity tests: These tests assess the impact of a substance on fertility, embryonic development, and offspring health.
5. Carcinogenicity tests: These tests evaluate the potential of a substance to cause cancer.
6. Ecotoxicity tests: These tests determine the effects of a substance on entire ecosystems, including plants, animals, and microorganisms.

Toxicity tests play a crucial role in protecting public health by helping to identify potentially harmful substances and establish safe exposure levels. They also contribute to the development of new drugs, chemicals, and consumer products by providing critical data for risk assessment and safety evaluation.

Developmental biology is a branch of biological research that studies the processes by which organisms grow and develop from fertilized eggs (zygotes) to adults. This field of study encompasses understanding the genetic, epigenetic, environmental, and molecular mechanisms that guide the developmental trajectory of an organism, including cellular differentiation, pattern formation, morphogenesis, and growth control.

Developmental biology has important implications for understanding congenital disorders, regenerative medicine, and evolutionary biology. Researchers in this field use a variety of model organisms, such as fruit flies (Drosophila melanogaster), zebrafish (Danio rerio), mice (Mus musculus), and nematodes (Caenorhabditis elegans), to investigate the fundamental principles that govern developmental processes. These insights can then be applied to understanding human development and disease.

"Nude mice" is a term used in the field of laboratory research to describe a strain of mice that have been genetically engineered to lack a functional immune system. Specifically, nude mice lack a thymus gland and have a mutation in the FOXN1 gene, which results in a failure to develop a mature T-cell population. This means that they are unable to mount an effective immune response against foreign substances or organisms.

The name "nude" refers to the fact that these mice also have a lack of functional hair follicles, resulting in a hairless or partially hairless phenotype. This feature is actually a secondary consequence of the same genetic mutation that causes their immune deficiency.

Nude mice are commonly used in research because their weakened immune system makes them an ideal host for transplanted tumors, tissues, and cells from other species, including humans. This allows researchers to study the behavior of these foreign substances in a living organism without the complication of an immune response. However, it's important to note that because nude mice lack a functional immune system, they must be kept in sterile conditions and are more susceptible to infection than normal mice.

Cytosine is one of the four nucleobases in the nucleic acid molecules DNA and RNA, along with adenine, guanine, and thymine (in DNA) or uracil (in RNA). The single-letter abbreviation for cytosine is "C."

Cytosine base pairs specifically with guanine through hydrogen bonding, forming a base pair. In DNA, the double helix consists of two complementary strands of nucleotides held together by these base pairs, such that the sequence of one strand determines the sequence of the other. This property is critical for DNA replication and transcription, processes that are essential for life.

Cytosine residues in DNA can undergo spontaneous deamination to form uracil, which can lead to mutations if not corrected by repair mechanisms. In RNA, cytosine can be methylated at the 5-carbon position to form 5-methylcytosine, a modification that plays a role in regulating gene expression and other cellular processes.

Histone-Lysine N-Methyltransferase is a type of enzyme that transfers methyl groups to specific lysine residues on histone proteins. These histone proteins are the main protein components of chromatin, which is the complex of DNA and proteins that make up chromosomes.

Histone-Lysine N-Methyltransferases play a crucial role in the regulation of gene expression by modifying the structure of chromatin. The addition of methyl groups to histones can result in either the activation or repression of gene transcription, depending on the specific location and number of methyl groups added.

These enzymes are important targets for drug development, as their dysregulation has been implicated in various diseases, including cancer. Inhibitors of Histone-Lysine N-Methyltransferases have shown promise in preclinical studies for the treatment of certain types of cancer.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

A bioreactor is a device or system that supports and controls the conditions necessary for biological organisms, cells, or tissues to grow and perform their specific functions. It provides a controlled environment with appropriate temperature, pH, nutrients, and other factors required for the desired biological process to occur. Bioreactors are widely used in various fields such as biotechnology, pharmaceuticals, agriculture, and environmental science for applications like production of therapeutic proteins, vaccines, biofuels, enzymes, and wastewater treatment.

I apologize for any confusion, but "dioxoles" is not a medical term or concept. It is a chemical term that refers to a specific type of organic compound containing a dioxole ring, which is a six-membered ring consisting of two oxygen atoms and two carbon atoms. Dioxoles can be found in various natural and synthetic substances, but they are not typically relevant to medical definitions or concepts.

If you have any questions related to medical terminology or concepts, I would be happy to help answer them for you.

RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.

An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.

Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.

For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.

Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.

Diphenylamine is an organic compound with the chemical formula (C6H5)2NH. It is a white to off-white crystalline powder that is soluble in alcohol, ether, and benzene. Diphenylamine is used as an antioxidant and stabilizer in various industrial applications, including the manufacture of rubber, plastics, and dyes. It is also used as a reagent in chemical synthesis and has been used in the analysis of certain types of explosives.

In the medical field, diphenylamine is not commonly used or encountered directly. However, it may be present as a contaminant in some pharmaceutical products or medical devices that contain rubber or plastic components treated with this compound as a stabilizer. Exposure to high levels of diphenylamine can cause irritation to the skin and eyes, and prolonged exposure has been linked to an increased risk of cancer in animal studies. However, there is currently no evidence to suggest that exposure to low levels of diphenylamine poses a significant health risk to humans.

Insertional mutagenesis is a process of introducing new genetic material into an organism's genome at a specific location, which can result in a change or disruption of the function of the gene at that site. This technique is often used in molecular biology research to study gene function and regulation. The introduction of the foreign DNA is typically accomplished through the use of mobile genetic elements, such as transposons or viruses, which are capable of inserting themselves into the genome.

The insertion of the new genetic material can lead to a loss or gain of function in the affected gene, resulting in a mutation. This type of mutagenesis is called "insertional" because the mutation is caused by the insertion of foreign DNA into the genome. The effects of insertional mutagenesis can range from subtle changes in gene expression to the complete inactivation of a gene.

This technique has been widely used in genetic research, including the study of developmental biology, cancer, and genetic diseases. It is also used in the development of genetically modified organisms (GMOs) for agricultural and industrial applications.

RNA-binding proteins (RBPs) are a class of proteins that selectively interact with RNA molecules to form ribonucleoprotein complexes. These proteins play crucial roles in the post-transcriptional regulation of gene expression, including pre-mRNA processing, mRNA stability, transport, localization, and translation. RBPs recognize specific RNA sequences or structures through their modular RNA-binding domains, which can be highly degenerate and allow for the recognition of a wide range of RNA targets. The interaction between RBPs and RNA is often dynamic and can be regulated by various post-translational modifications of the proteins or by environmental stimuli, allowing for fine-tuning of gene expression in response to changing cellular needs. Dysregulation of RBP function has been implicated in various human diseases, including neurological disorders and cancer.

Embryonic induction is a process that occurs during the development of a multicellular organism, where one group of cells in the embryo signals and influences the developmental fate of another group of cells. This interaction leads to the formation of specific structures or organs in the developing embryo. The signaling cells that initiate the process are called organizers, and they release signaling molecules known as morphogens that bind to receptors on the target cells and trigger a cascade of intracellular signals that ultimately lead to changes in gene expression and cell fate. Embryonic induction is a crucial step in the development of complex organisms and plays a key role in establishing the body plan and organizing the different tissues and organs in the developing embryo.

Cell communication, also known as cell signaling, is the process by which cells exchange and transmit signals between each other and their environment. This complex system allows cells to coordinate their functions and maintain tissue homeostasis. Cell communication can occur through various mechanisms including:

1. Autocrine signaling: When a cell releases a signal that binds to receptors on the same cell, leading to changes in its behavior or function.
2. Paracrine signaling: When a cell releases a signal that binds to receptors on nearby cells, influencing their behavior or function.
3. Endocrine signaling: When a cell releases a hormone into the bloodstream, which then travels to distant target cells and binds to specific receptors, triggering a response.
4. Synaptic signaling: In neurons, communication occurs through the release of neurotransmitters that cross the synapse and bind to receptors on the postsynaptic cell, transmitting electrical or chemical signals.
5. Contact-dependent signaling: When cells physically interact with each other, allowing for the direct exchange of signals and information.

Cell communication is essential for various physiological processes such as growth, development, differentiation, metabolism, immune response, and tissue repair. Dysregulation in cell communication can contribute to diseases, including cancer, diabetes, and neurological disorders.

Transplantation conditioning, also known as preparative regimen or immunoablative therapy, refers to the use of various treatments prior to transplantation of cells, tissues or organs. The main goal of transplantation conditioning is to suppress the recipient's immune system, allowing for successful engraftment and minimizing the risk of rejection of the donor tissue.

There are two primary types of transplantation conditioning: myeloablative and non-myeloablative.

1. Myeloablative conditioning is a more intensive regimen that involves the use of high-dose chemotherapy, radiation therapy or both. This approach eliminates not only immune cells but also stem cells in the bone marrow, requiring the recipient to receive a hematopoietic cell transplant (HCT) from the donor to reconstitute their blood and immune system.
2. Non-myeloablative conditioning is a less intensive regimen that primarily targets immune cells while sparing the stem cells in the bone marrow. This approach allows for mixed chimerism, where both recipient and donor immune cells coexist, reducing the risk of severe complications associated with myeloablative conditioning.

The choice between these two types of transplantation conditioning depends on various factors, including the type of transplant, patient's age, overall health, and comorbidities. Both approaches carry risks and benefits, and the decision should be made carefully by a multidisciplinary team of healthcare professionals in consultation with the patient.

Neuroglia, also known as glial cells or simply glia, are non-neuronal cells that provide support and protection for neurons in the nervous system. They maintain homeostasis, form myelin sheaths around nerve fibers, and provide structural support. They also play a role in the immune response of the central nervous system. Some types of neuroglia include astrocytes, oligodendrocytes, microglia, and ependymal cells.

Jumonji domain-containing histone demethylases (JHDMs) are a family of enzymes that are responsible for removing methyl groups from specific residues on histone proteins. These enzymes play crucial roles in the regulation of gene expression by modifying the chromatin structure and influencing the accessibility of transcription factors to DNA.

JHDMs contain a conserved Jumonji C (JmjC) domain, which is responsible for their demethylase activity. They are classified into two main groups based on the type of methyl group they remove: lysine-specific demethylases (KDMs) and arginine-specific demethylases (RDMs).

KDMs can be further divided into several subfamilies, including KDM2/7, KDM3, KDM4, KDM5, and KDM6, based on their substrate specificity and the number of methyl groups they remove. For example, KDM4 enzymes specifically demethylate di- and tri-methylated lysine 9 and lysine 36 residues on histone H3, while KDM5 enzymes target mono-, di-, and tri-methylated lysine 4 residues on histone H3.

RDMs, on the other hand, are responsible for demethylating arginine residues on histones, including symmetrically or asymmetrically dimethylated arginine 2, 8, 17, and 26 residues on histone H3 and H4.

Dysregulation of JHDMs has been implicated in various human diseases, including cancer, neurological disorders, and cardiovascular diseases. Therefore, understanding the functions and regulation of JHDMs is essential for developing novel therapeutic strategies to treat these diseases.

Bromodeoxyuridine (BrdU) is a synthetic thymidine analog that can be incorporated into DNA during cell replication. It is often used in research and medical settings as a marker for cell proliferation or as a tool to investigate DNA synthesis and repair. When cells are labeled with BrdU and then examined using immunofluorescence or other detection techniques, the presence of BrdU can indicate which cells have recently divided or are actively synthesizing DNA.

In medical contexts, BrdU has been used in cancer research to study tumor growth and response to treatment. It has also been explored as a potential therapeutic agent for certain conditions, such as neurodegenerative diseases, where promoting cell proliferation and replacement of damaged cells may be beneficial. However, its use as a therapeutic agent is still experimental and requires further investigation.

Genetic enhancer elements are DNA sequences that increase the transcription of specific genes. They work by binding to regulatory proteins called transcription factors, which in turn recruit RNA polymerase II, the enzyme responsible for transcribing DNA into messenger RNA (mRNA). This results in the activation of gene transcription and increased production of the protein encoded by that gene.

Enhancer elements can be located upstream, downstream, or even within introns of the genes they regulate, and they can act over long distances along the DNA molecule. They are an important mechanism for controlling gene expression in a tissue-specific and developmental stage-specific manner, allowing for the precise regulation of gene activity during embryonic development and throughout adult life.

It's worth noting that genetic enhancer elements are often referred to simply as "enhancers," and they are distinct from other types of regulatory DNA sequences such as promoters, silencers, and insulators.

A lethal gene is a type of gene that causes the death of an organism or prevents it from surviving to maturity. This can occur when the gene contains a mutation that disrupts the function of a protein essential for the organism's survival. In some cases, the presence of two copies of a lethal gene (one inherited from each parent) can result in a condition that is incompatible with life, and the organism will not survive beyond embryonic development or shortly after birth.

Lethal genes can also contribute to genetic disorders, where the disruption of protein function caused by the mutation leads to progressive degeneration and ultimately death. In some cases, lethal genes may only cause harm when expressed in certain tissues or at specific stages of development, leading to a range of phenotypes from embryonic lethality to adult-onset disorders.

It's important to note that the term "lethal" is relative and can depend on various factors such as genetic background, environmental conditions, and the presence of modifier genes. Additionally, some lethal genes may be targeted for gene editing or other therapeutic interventions to prevent their harmful effects.

Doxycycline is a broad-spectrum antibiotic, which is a type of medication used to treat infections caused by bacteria and other microorganisms. It belongs to the tetracycline class of antibiotics. Doxycycline works by inhibiting the production of proteins that bacteria need to survive and multiply.

Doxycycline is used to treat a wide range of bacterial infections, including respiratory infections, skin infections, urinary tract infections, sexually transmitted diseases, and severe acne. It is also used to prevent malaria in travelers who are visiting areas where malaria is common.

Like all antibiotics, doxycycline should be taken exactly as directed by a healthcare professional. Misuse of antibiotics can lead to the development of drug-resistant bacteria, which can make infections harder to treat in the future.

It's important to note that doxycycline can cause photosensitivity, so it is recommended to avoid prolonged sun exposure and use sun protection while taking this medication. Additionally, doxycycline should not be taken during pregnancy or by children under the age of 8 due to potential dental and bone development issues.

Cytological techniques refer to the methods and procedures used to study individual cells, known as cytopathology. These techniques are used in the diagnosis and screening of various medical conditions, including cancer. The most common cytological technique is the Pap test, which involves collecting cells from the cervix and examining them for abnormalities. Other cytological techniques include fine-needle aspiration (FNA), which involves using a thin needle to withdraw cells from a tumor or lump, and body fluids analysis, which involves examining cells present in various bodily fluids such as urine, sputum, and pleural effusions. These techniques allow for the examination of cellular structure, morphology, and other characteristics to help diagnose and monitor diseases.

Glycogen Synthase Kinase 3 (GSK-3) is a serine/threonine protein kinase that plays a crucial role in the regulation of several cellular processes, including glycogen metabolism, cell signaling, gene transcription, and apoptosis. It was initially discovered as a key enzyme involved in glycogen metabolism due to its ability to phosphorylate and inhibit glycogen synthase, an enzyme responsible for the synthesis of glycogen from glucose.

GSK-3 exists in two isoforms, GSK-3α and GSK-3β, which share a high degree of sequence similarity and are widely expressed in various tissues. Both isoforms are constitutively active under normal conditions and are regulated through inhibitory phosphorylation by several upstream signaling pathways, such as insulin, Wnt, and Hedgehog signaling.

Dysregulation of GSK-3 has been implicated in the pathogenesis of various diseases, including diabetes, neurodegenerative disorders, and cancer. In recent years, GSK-3 has emerged as an attractive therapeutic target for the development of novel drugs to treat these conditions.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

In situ hybridization, fluorescence (FISH) is a type of molecular cytogenetic technique used to detect and localize the presence or absence of specific DNA sequences on chromosomes through the use of fluorescent probes. This technique allows for the direct visualization of genetic material at a cellular level, making it possible to identify chromosomal abnormalities such as deletions, duplications, translocations, and other rearrangements.

The process involves denaturing the DNA in the sample to separate the double-stranded molecules into single strands, then adding fluorescently labeled probes that are complementary to the target DNA sequence. The probe hybridizes to the complementary sequence in the sample, and the location of the probe is detected by fluorescence microscopy.

FISH has a wide range of applications in both clinical and research settings, including prenatal diagnosis, cancer diagnosis and monitoring, and the study of gene expression and regulation. It is a powerful tool for identifying genetic abnormalities and understanding their role in human disease.

GATA2 transcription factor is a protein that plays a crucial role in the development and function of blood cells. It belongs to the family of GATA transcription factors, which are characterized by their ability to bind to specific DNA sequences called GATA motifs, through a zinc finger domain. The GATA2 transcription factor, in particular, is essential for the development of hematopoietic stem and progenitor cells (HSPCs), which give rise to all blood cell types.

GATA2 binds to the regulatory regions of genes involved in hematopoiesis and modulates their transcription, thereby controlling the differentiation, proliferation, and survival of HSPCs. Mutations in the GATA2 gene have been associated with various hematological disorders, such as acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and severe congenital neutropenia. These genetic alterations can lead to impaired hematopoiesis, dysfunctional immune cells, and an increased risk of developing blood cancers.

In summary, GATA2 transcription factor is a protein that regulates the development and function of blood cells by controlling the expression of genes involved in hematopoiesis. Genetic defects in this transcription factor can result in various hematological disorders and predispose individuals to blood cancers.

The mesencephalon, also known as the midbrain, is the middle portion of the brainstem that connects the hindbrain (rhombencephalon) and the forebrain (prosencephalon). It plays a crucial role in several important functions including motor control, vision, hearing, and the regulation of consciousness and sleep-wake cycles. The mesencephalon contains several important structures such as the cerebral aqueduct, tectum, tegmentum, cerebral peduncles, and several cranial nerve nuclei (III and IV).

Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.

Growth inhibitors, in a medical context, refer to substances or agents that reduce or prevent the growth and proliferation of cells. They play an essential role in regulating normal cellular growth and can be used in medical treatments to control the excessive growth of unwanted cells, such as cancer cells.

There are two main types of growth inhibitors:

1. Endogenous growth inhibitors: These are naturally occurring molecules within the body that help regulate cell growth and division. Examples include retinoids, which are vitamin A derivatives, and interferons, which are signaling proteins released by host cells in response to viruses.

2. Exogenous growth inhibitors: These are synthetic or natural substances from outside the body that can be used to inhibit cell growth. Many chemotherapeutic agents and targeted therapies for cancer treatment fall into this category. They work by interfering with specific pathways involved in cell division, such as DNA replication or mitosis, or by inducing apoptosis (programmed cell death) in cancer cells.

It is important to note that growth inhibitors may also affect normal cells, which can lead to side effects during treatment. The challenge for medical researchers is to develop targeted therapies that specifically inhibit the growth of abnormal cells while minimizing harm to healthy cells.

The foreskin is a double-layered fold of skin that covers and protects the head (glans) of the penis. It is a normal part of male anatomy and varies in length and coverage from person to person. The inner layer of the foreskin is highly sensitive and contains a high concentration of nerve endings, which can contribute to sexual pleasure.

In some cases, the foreskin may become tight or difficult to retract (a condition known as phimosis), which can cause discomfort or pain during sexual activity or other activities that stretch the foreskin. In these cases, medical intervention may be necessary to alleviate the problem. Some people choose to undergo circumcision, a surgical procedure in which the foreskin is removed, for cultural, religious, or personal reasons. However, circumcision is not medically necessary for most people and carries some risks, such as infection, bleeding, and scarring.

Cluster analysis is a statistical method used to group similar objects or data points together based on their characteristics or features. In medical and healthcare research, cluster analysis can be used to identify patterns or relationships within complex datasets, such as patient records or genetic information. This technique can help researchers to classify patients into distinct subgroups based on their symptoms, diagnoses, or other variables, which can inform more personalized treatment plans or public health interventions.

Cluster analysis involves several steps, including:

1. Data preparation: The researcher must first collect and clean the data, ensuring that it is complete and free from errors. This may involve removing outlier values or missing data points.
2. Distance measurement: Next, the researcher must determine how to measure the distance between each pair of data points. Common methods include Euclidean distance (the straight-line distance between two points) or Manhattan distance (the distance between two points along a grid).
3. Clustering algorithm: The researcher then applies a clustering algorithm, which groups similar data points together based on their distances from one another. Common algorithms include hierarchical clustering (which creates a tree-like structure of clusters) or k-means clustering (which assigns each data point to the nearest centroid).
4. Validation: Finally, the researcher must validate the results of the cluster analysis by evaluating the stability and robustness of the clusters. This may involve re-running the analysis with different distance measures or clustering algorithms, or comparing the results to external criteria.

Cluster analysis is a powerful tool for identifying patterns and relationships within complex datasets, but it requires careful consideration of the data preparation, distance measurement, and validation steps to ensure accurate and meaningful results.

Notch 1 is a type of receptor that belongs to the family of single-transmembrane receptors known as Notch receptors. It is a heterodimeric transmembrane protein composed of an extracellular domain and an intracellular domain, which play crucial roles in cell fate determination, proliferation, differentiation, and apoptosis during embryonic development and adult tissue homeostasis.

The Notch 1 receptor is activated through a conserved mechanism of ligand-receptor interaction, where the extracellular domain of the receptor interacts with the membrane-bound ligands Jagged 1 or 2 and Delta-like 1, 3, or 4 expressed on adjacent cells. This interaction triggers a series of proteolytic cleavages that release the intracellular domain of Notch 1 (NICD) from the membrane. NICD then translocates to the nucleus and interacts with the DNA-binding protein CSL (CBF1/RBPJκ in mammals) and coactivators Mastermind-like proteins to regulate the expression of target genes, including members of the HES and HEY families.

Mutations in NOTCH1 have been associated with various human diseases, such as T-cell acute lymphoblastic leukemia (T-ALL), a type of cancer that affects the immune system's T cells, and vascular diseases, including arterial calcification, atherosclerosis, and aneurysms.

OSM-LIF receptors are a type of cell surface receptor that bind to the cytokines Oncostatin M (OSM) and Leukemia Inhibitory Factor (LIF). These receptors are part of the class I cytokine receptor family, which share a common structure and signaling mechanism.

The OSM-LIF receptor is composed of two subunits: gp130 and LIFR (LIF receptor beta). The binding of OSM or LIF to the extracellular domain of the LIFR subunit results in the recruitment of gp130, which then activates a series of intracellular signaling pathways, including the JAK-STAT and MAPK pathways.

OSM-LIF receptors play important roles in various biological processes, such as cell proliferation, differentiation, survival, and inflammation. Dysregulation of OSM-LIF signaling has been implicated in several diseases, including cancer, autoimmune disorders, and neurological disorders. Therefore, targeting OSM-LIF receptors has emerged as a potential therapeutic strategy for these conditions.

The extracellular matrix (ECM) is a complex network of biomolecules that provides structural and biochemical support to cells in tissues and organs. It is composed of various proteins, glycoproteins, and polysaccharides, such as collagens, elastin, fibronectin, laminin, and proteoglycans. The ECM plays crucial roles in maintaining tissue architecture, regulating cell behavior, and facilitating communication between cells. It provides a scaffold for cell attachment, migration, and differentiation, and helps to maintain the structural integrity of tissues by resisting mechanical stresses. Additionally, the ECM contains various growth factors, cytokines, and chemokines that can influence cellular processes such as proliferation, survival, and differentiation. Overall, the extracellular matrix is essential for the normal functioning of tissues and organs, and its dysregulation can contribute to various pathological conditions, including fibrosis, cancer, and degenerative diseases.

Surface antigens are molecules found on the surface of cells that can be recognized by the immune system as being foreign or different from the host's own cells. Antigens are typically proteins or polysaccharides that are capable of stimulating an immune response, leading to the production of antibodies and activation of immune cells such as T-cells.

Surface antigens are important in the context of infectious diseases because they allow the immune system to identify and target infected cells for destruction. For example, viruses and bacteria often display surface antigens that are distinct from those found on host cells, allowing the immune system to recognize and attack them. In some cases, these surface antigens can also be used as targets for vaccines or other immunotherapies.

In addition to their role in infectious diseases, surface antigens are also important in the context of cancer. Tumor cells often display abnormal surface antigens that differ from those found on normal cells, allowing the immune system to potentially recognize and attack them. However, tumors can also develop mechanisms to evade the immune system, making it difficult to mount an effective response.

Overall, understanding the properties and behavior of surface antigens is crucial for developing effective immunotherapies and vaccines against infectious diseases and cancer.

DNA damage refers to any alteration in the structure or composition of deoxyribonucleic acid (DNA), which is the genetic material present in cells. DNA damage can result from various internal and external factors, including environmental exposures such as ultraviolet radiation, tobacco smoke, and certain chemicals, as well as normal cellular processes such as replication and oxidative metabolism.

Examples of DNA damage include base modifications, base deletions or insertions, single-strand breaks, double-strand breaks, and crosslinks between the two strands of the DNA helix. These types of damage can lead to mutations, genomic instability, and chromosomal aberrations, which can contribute to the development of diseases such as cancer, neurodegenerative disorders, and aging-related conditions.

The body has several mechanisms for repairing DNA damage, including base excision repair, nucleotide excision repair, mismatch repair, and double-strand break repair. However, if the damage is too extensive or the repair mechanisms are impaired, the cell may undergo apoptosis (programmed cell death) to prevent the propagation of potentially harmful mutations.

Electroporation is a medical procedure that involves the use of electrical fields to create temporary pores or openings in the cell membrane, allowing for the efficient uptake of molecules, drugs, or genetic material into the cell. This technique can be used for various purposes, including delivering genes in gene therapy, introducing drugs for cancer treatment, or transforming cells in laboratory research. The electrical pulses are carefully controlled to ensure that they are strong enough to create pores in the membrane without causing permanent damage to the cell. After the electrical field is removed, the pores typically close and the cell membrane returns to its normal state.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

Leukemia Inhibitory Factor Receptor alpha Subunit (LIFR-α) is a protein that forms part of the Leukemia Inhibitory Factor (LIF) receptor complex. LIF is a cytokine, or signaling molecule, that plays important roles in various biological processes such as cell differentiation, survival, and proliferation.

The LIFR-α subunit combines with the glycoprotein 130 (gp130) subunit to form a functional receptor for LIF. When LIF binds to this receptor complex, it triggers a series of intracellular signaling events that ultimately regulate gene expression and cell behavior.

Mutations in the LIFR-α gene have been associated with certain diseases, including some forms of cancer. For example, reduced expression of LIFR-α has been observed in leukemia cells, suggesting that it may play a role in the development or progression of this disease. However, more research is needed to fully understand the functional significance of LIFR-α and its role in human health and disease.

The epidermis is the outermost layer of the skin, composed mainly of stratified squamous epithelium. It forms a protective barrier that prevents water loss and inhibits the entry of microorganisms. The epidermis contains no blood vessels, and its cells are nourished by diffusion from the underlying dermis. The bottom-most layer of the epidermis, called the stratum basale, is responsible for generating new skin cells that eventually move up to replace dead cells on the surface. This process of cell turnover takes about 28 days in adults.

The most superficial part of the epidermis consists of dead cells called squames, which are constantly shed and replaced. The exact rate at which this happens varies depending on location; for example, it's faster on the palms and soles than elsewhere. Melanocytes, the pigment-producing cells, are also located in the epidermis, specifically within the stratum basale layer.

In summary, the epidermis is a vital part of our integumentary system, providing not only physical protection but also playing a crucial role in immunity and sensory perception through touch receptors called Pacinian corpuscles.

Dopaminergic neurons are a type of specialized brain cells that produce, synthesize, and release the neurotransmitter dopamine. These neurons play crucial roles in various brain functions, including motivation, reward processing, motor control, and cognition. They are primarily located in several regions of the midbrain, such as the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA).

Dopaminergic neurons have a unique physiology characterized by their ability to generate slow, irregular electrical signals called pacemaker activity. This distinctive firing pattern allows dopamine to be released in a controlled manner, which is essential for proper brain function.

The degeneration and loss of dopaminergic neurons in the SNc are associated with Parkinson's disease, a neurodegenerative disorder characterized by motor impairments such as tremors, rigidity, and bradykinesia (slowness of movement). The reduction in dopamine levels caused by this degeneration leads to an imbalance in the brain's neural circuitry, resulting in the characteristic symptoms of Parkinson's disease.

Neoplasms are abnormal growths of cells or tissues in the body that serve no physiological function. They can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms are typically slow growing and do not spread to other parts of the body, while malignant neoplasms are aggressive, invasive, and can metastasize to distant sites.

Neoplasms occur when there is a dysregulation in the normal process of cell division and differentiation, leading to uncontrolled growth and accumulation of cells. This can result from genetic mutations or other factors such as viral infections, environmental exposures, or hormonal imbalances.

Neoplasms can develop in any organ or tissue of the body and can cause various symptoms depending on their size, location, and type. Treatment options for neoplasms include surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy, among others.

Graft-versus-host disease (GVHD) is a condition that can occur after an allogeneic hematopoietic stem cell transplantation (HSCT), where the donated immune cells (graft) recognize the recipient's tissues (host) as foreign and attack them. This results in inflammation and damage to various organs, particularly the skin, gastrointestinal tract, and liver.

Acute GVHD typically occurs within 100 days of transplantation and is characterized by symptoms such as rash, diarrhea, and liver dysfunction. Chronic GVHD, on the other hand, can occur after 100 days or even years post-transplant and may present with a wider range of symptoms, including dry eyes and mouth, skin changes, lung involvement, and issues with mobility and flexibility in joints.

GVHD is a significant complication following allogeneic HSCT and can have a substantial impact on the patient's quality of life and overall prognosis. Preventative measures, such as immunosuppressive therapy, are often taken to reduce the risk of GVHD, but its management remains a challenge in transplant medicine.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

... are equivalent to embryonic stem cells, leading these cells to be known as induced pluripotent stem cells (iPS cells). This ... Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre- ... "Human Embryonic Stem Cells Derived by Somatic Cell Nuclear Transfer". Cell. 153 (6): 1228-1238. doi:10.1016/j.cell.2013.05.006 ... bone marrow-mesenchymal stem cells and adipose-derived stem cells. Muse cells are able to generate cells representative of all ...
"Second Human Embryonic Stem Cell Clinical Trial to Start." USA Today, November 22. Schwartz, S et al. (2012). "Embryonic Stem ... The FDA approved a phase I clinical trial with ViaCyte beta cells derived from human embryonic stem cell for the treatment of ... Phase I/II clinical trials involving retinal pigment epithelial (RPE) cells, derived from human embryonic stem cells, for the ... Two clinical trials involving derivatives of human embryonic stem cells were approved in 2010. Advanced Cell Technology (ACT) ...
National Academies Human Embryonic Stem Cell Research Advisory Committee Guidelines for Human Embryonic Stem Cell Research ( ... 2005 Guidelines for Human Embryonic Stem Cell Research to manage the ethical and legal concerns in human embryonic stem cell ... Guidelines for Human Embryonic Stem Cell Research 2007 Amendments Hanna, K.E. (2007). Ball of confusion: How stem cells have ... stem cell research, molecular biology, assisted reproduction, and ethical and legal issues in human embryonic stem cell ...
"Embryonic Stem Cell". Archived from the original on 2006-09-09. Retrieved 2008-01-01. Frisch M, Melchinger AE (2005). " ... In gene-knockout experiments in particular, where the knockout is performed on easily cultured stem cell lines, but is required ... with the percentage of genetic material from the original stem cells reduced to a minimum (on the order of 0.01%). Due to the ... but also the minimum percentage of genetic material from the original stem cell line. A consomic strain is an inbred strain ...
Keywords: Bimodality; Bivalency; Chromatin state; Embryonic stem cells; Genome regulatory network; Hidden Markov model; Pseudo ... cells. The model of poised promoters postulates that bivalent chromatin in ES cells is resolved to Mono valency upon ... doi:10.1016/j.cell.2006.07.010. ISSN 0092-8674. PMID 16873056. Blanco E., Gonzalez Ramirez M., Alcaine-colet , A., Aranda the ... modification in the same area of this kind and is proposed to play a pivotal role related to pluripotency in embryonic stem (ES ...
... which is remarkable in the development of stem cell biology. Fibroblast Embryonic stem cell Jian-ming Xu (2005). "Preparation, ... "Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors". Cell. 126 (4): 663- ... are widely used as feeder in embryonic stem cell culture because they can mimic the microenvironment in embryo. In 2006, Shinya ... 2015). Principles of Stem Cell Biology and Cancer: Future Applications and Therapeutics. John Wiley & Sons. pp. 3-5. ISBN 978-1 ...
"Neural specification from human embryonic stem cells". In Odorico, John S.; et al. (eds.). Human embryonic stem cells. Garland ... which contains primary neural stem cells called radial glial cells and serves as the main source of neurons produced during ... Neural crest cells will migrate through the embryo and will give rise to several cell populations, including pigment cells and ... The variation in cell shapes is partially determined by the location of the nucleus within the cell, causing bulging in areas ...
This work was foundational in the field of embryonic stem cells and stem cell research. Stevens' later studies focused on ... Stevens called these cell types "pluripotent embryonic stem cells." In order to study this phenomenon, Stevens selectively bred ... "Embryonic Stem Cell Pioneer Dies". The Scientist Magazine®. Peterson, Joyce (March 30, 2015). "Leroy C. Stevens, Ph.D., 1920- ... was a scientist at The Jackson Laboratory acknowledged as one of the pioneers of embryonic stem cell research. Stevens was born ...
Houbaviy, HB; Murray MF; Sharp PA (2003). "Embryonic stem cell-specific MicroRNAs". Dev Cell. 5 (2): 351-358. doi:10.1016/S1534 ... It has been shown that miR-130a is expressed in the hematopoietic stem/progenitor cell compartment but not in mature blood ... 2006). "Downregulation of miR-122 in the rodent and human hepatocellular carcinomas". J. Cell. Biochem. 99 (3): 671-8. doi: ... Mature microRNAs are processed from the precursor stem-loop by the Dicer enzyme. In this case, the mature sequence is excised ...
Houbaviy HB, Murray MF, Sharp PA (August 2003). "Embryonic stem cell-specific MicroRNAs". Developmental Cell. 5 (2): 351-8. doi ... miRNA libraries constructed from cloning and sequencing short RNAs derived from cultures of mouse embryonic stem cells have ... Once nutritional conditions becomes favorable, the expression of mir-235 is downregulated by IIS pathway, and stem cells leave ... These totipotent cells represent the earliest stages of mammalian development (they are derived from the inner cells of the ...
Houbaviy HB, Murray MF, Sharp PA (August 2003). "Embryonic stem cell-specific MicroRNAs". Developmental Cell. 5 (2): 351-8. doi ... "Ethanol-induced expression of ET-1 and ET-BR in liver sinusoidal endothelial cells and human endothelial cells involves hypoxia ... was evaluated by transfecting cervical cancer cells (SiHa and ME-180) with anti-miR-199a oligonucleotides and the cell ... Dostie J, Mourelatos Z, Yang M, Sharma A, Dreyfuss G (February 2003). "Numerous microRNPs in neuronal cells containing novel ...
Dani C (1999). "Embryonic stem cell-derived adipogenesis". Cells Tissues Organs (Print). 165 (3-4): 173-80. doi:10.1159/ ... A lipoblast is a precursor cell for an adipocyte. Alternate terms include adipoblast and preadipocyte. Early stages are almost ... Adipogenesis Adipose differentiation-related protein Lipoblastoma List of human cell types derived from the germ layers Michael ... v t e (Cell biology, All stub articles, Pathology stubs). ...
Houbaviy HB, Murray MF, Sharp PA (Aug 2003). "Embryonic stem cell-specific MicroRNAs". Developmental Cell. 5 (2): 351-8. doi: ... The presence of miR-34 products has also been confirmed in embryonic stem cells. miR-34 has been shown to be maternally ... The precursor miRNA stem-loop is processed in the cytoplasm of the cell, with the predominant miR-34 mature sequence excised ... p53-deficient human gastric cancer cells, restoration of functional miR-34 inhibits cell growth and induces chemosensitization ...
Houbaviy, HB; Murray MF; Sharp PA (2003). "Embryonic stem cell-specific MicroRNAs". Dev Cell. 5 (2): 351-358. doi:10.1016/S1534 ... increased during the induction of endothelial cell differentiation in embryonic stem cells (tested on murine) or induce ... B-cell lymphomas * Cell lines * Cerebellum * Purkinje cells * HeLa cells Finally they have tissues-specific miRNA expression. ... 2012). "Role of the MicroRNA-17-92 Cluster in the Endothelial Differentiation of Stem Cells". Journal of Vascular Research. 49 ...
"Ethics of Embryonic Stem Cell Research". The United Methodist Church. 2016. Retrieved 9 February 2021. Church Policies and ... adult stem cells that have been made pluripotent, parthenotes, sperm cells, or egg cells, and cells that produce sperm or eggs ... to pass legislation that would authorize funding for derivation of and medical research on human embryonic stem cells that were ... those donating early embryos have given their prior informed consent to their use in stem cell research; 3. the embryos were ...
"Ethics of Embryonic Stem Cell Research". The United Methodist Church. Archived from the original on April 16, 2013. Retrieved ... It supports research on stem cells retrieved from umbilical cords and adult stem cells, stating that there are "few moral ...
doi:10.1093/cb/cbn006 Tuffs, A. (2001). "Germany debates embryonic stem cell research". BMJ, 8, 323. Taylor, R. (1998). The ... The Protestant leadership in Germany is divided on the issue of stem cell research; however, those opposing liberalising laws ... The Case of Stem Cell Research". Christian Bioethics, 14(1), 95-107. ... contributing to the debate around bioethics and stem cell research. ...
As embryonic stem cells are derived from the inner cell mass at the blastocyst stage, removing them from the inner cell mass ... Removal of LIF pushes stem cells toward differentiation, however genetic manipulation of embryonic stem cells allows for LIF ... Martello G, Smith A (2014). "The nature of embryonic stem cells". Annual Review of Cell and Developmental Biology. 30: 647-75. ... LIF is often added to stem cell culture media as an alternative to feeder cell culture, due to the limitation that feeder cells ...
In 2010, the Foundation issued a public policy document on embryonic stem cell research. In 2012 the Irish Stem Cell Foundation ... The Adult Stem Cell Foundation of Ireland'. The Irish Stem Cell Foundation supports all types of stem cell research governed by ... "An Irish Stem Cell Perspective". Forbes.com. Retrieved 29 January 2019. "Government urged on stem cell legislation". Rte.ie. 8 ... The Irish Stem Cell Foundation is Ireland's National Stem Cell Research Organisation. A Member of the International Consortium ...
Capito supports embryonic stem cell research. In 2001, Capito voted for a bill to ban the cloning of human embryos. In May 2005 ... Also in 2007, Capito again voted in favor of funding stem-cell research. She also voted in favor of research using stem cells ... to repeal restrictions on embryonic stem-cell research funding. Capito also voted in 2006 to attempt to override President ...
"Stem Cells in Limbo". Time. Archived from the original on May 2, 2013. Retrieved September 1, 2008. "Bush Vetoes Embryonic Stem ... Bush has said he supports adult stem cell research and has supported federal legislation that finances adult stem cell research ... However, Bush did not support embryonic stem cell research. On August 9, 2001, Bush signed an executive order lifting the ban ... "President Discusses Stem Cell Research". Office of the President. Archived from the original on May 6, 2013. "NIH's Role in ...
Reid supported embryonic stem cell research. Over the time, Reid shifted his support towards more progressive views. Regarding ... Reid, Harry M. "George Bush Vetos [sic] Stem Cell Research". giveemhellharry.com. Archived from the original on September 29, ...
ES cells and ES cells. The combination of embryonic stem cell and diploid embryo is a common technique used for the making of ... If embryonic stem cells are to be used for gene targeting to make a chimera, the following procedure is common: a construct for ... Ledermann, B (2000). "Embryonic Stem Cell and Gene Targeting". Experimental Physiology. 85 (6): 603-613. doi:10.1017/ ... These kinds of chimeras can be made through either aggregation of stem cells and the diploid embryo or injection of the stem ...
Kursad Turksen (2006). Embryonic Stem Cell Protocols: Differentiation models. Humana Press. pp. 263-. ISBN 978-1-58829-784-6. ... Interstitial cells of Cajal (ICC) are interstitial cells found in the gastrointestinal tract. Before considering these cells ... Myenteric interstitial cells of Cajal (ICC-MY) serve as pacemaker cells that generate the bioelectrical events known as slow ... This cell type can be characterized morphologically as having a small cell body often triangular or stellate-shaped with ...
... limits to embryonic stem cell research; constitutional marriage protection amendments; access to birth control and emergency ...
6 August 2013). "Do pluripotent stem cells exist in adult mice as very small embryonic stem cells?". Stem Cell Reports. 1 (2): ... such as mesenchymal stem cell, adipose-derived stem cell, endothelial stem cell, etc.). A great deal of adult stem cell ... August 2013). "Do pluripotent stem cells exist in adult mice as very small embryonic stem cells?". Stem Cell Reports. 1 (2): ... these cells have the same ability as embryonic stem cells to develop into many different cell types. Olfactory stem cells hold ...
"Embryonic pathway delivers stem cell traits". MIT News. "Marker to identify, attack breast cancer stem cells discovered". ... "The Epithelial-Mesenchymal Transition Generates Cells with Properties of Stem Cells". Cell. 133 (4): 704-15. doi:10.1016/j.cell ... Cell. 117 (7): 927-939. doi:10.1016/j.cell.2004.06.006. ISSN 0092-8674. "Decoding the emergence of metastatic cancer stem cells ... "Embryonic pathway delivers stem cell traits". Whitehead Institute of MIT. Yang, Jing; Mani, Sendurai A; Donaher, Joana Liu; ...
"House passes embryonic stem cell bill". CNN. 2005-05-25. Retrieved 2010-05-01. "President Bush Delivers Remarks On U.S. Space ... President Bush supported adult stem cell research and umbilical cord blood stem cell research. However, Bush opposed any new ... embryonic stem cell research, and had limited the federal funding of existing research. Federal funding for embryonic stem cell ... While Bush claimed that more than 60 embryonic stem cell lines already existed from privately funded research, scientists in ...
He opposes embryonic stem cell research. He opposes human cloning. Rogers has a "D" rating from NORML for his voting history ...
... the Stem Cell and Policy Award from the Genetics Policy Institute (2005); Pioneer in Embryonic Stem Cell Research (2006) ... use of human and primate stem cells to determine the potential of stem cell-based medical therapies and better understand cell ... Schatten G, Smith J, Navara C, Park JH, Pedersen R (June 2005). "Culture of human embryonic stem cells". Nature Methods. 2 (6 ... Gerald Schatten (born 1949) is an American stem cell researcher with interests in cell, developmental, and reproductive biology ...
... are equivalent to embryonic stem cells, leading these cells to be known as induced pluripotent stem cells (iPS cells). This ... Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre- ... "Human Embryonic Stem Cells Derived by Somatic Cell Nuclear Transfer". Cell. 153 (6): 1228-1238. doi:10.1016/j.cell.2013.05.006 ... bone marrow-mesenchymal stem cells and adipose-derived stem cells. Muse cells are able to generate cells representative of all ...
Scientists were able to produce from human embryonic stem cells a highly pure, large quantity of functioning neurons that will ... Suns method prodded human embryonic stem cells to differentiate into neural stem cells, the cells that give rise to neurons. ... Scientists with the Institute of Stem Cell Biology and Medicine at UCLA were able to produce from human embryonic stem cells a ... from human embryonic stem cells. However, the percentage of neurons in the cell culture was not high and the neurons were ...
In a surprising new finding, scientists have shown that mouse stem cells treated with the drug reverted to an embryonic state ... in the form of a drug that can erase the tiny labels that tell cells where to start reading their DNA. ... If you want to harness the full power of stem cells, all you might need is an eraser -- ... MLL1 Inhibition Reprograms Epiblast Stem Cells to Naive Pluripotency. Cell Stem Cell, 2016; DOI: 10.1016/j.stem.2016.02.004 ...
... which results in cells that have the developmental characteristics of human embryonic stem cells. ... The fusion causes the adult cells to undergo genetic reprogramming, ... Researchers have developed a new technique for creating human embryonic stem cells by fusing adult somatic cells with embryonic ... Cell, Cell Line, Cell Nucleus, Chemicals, Chromosome, Embryo, Embryology, Embryonic Development, Embryonic Stem Cell, Embryonic ...
Broadcasting from St. Louis, USA at AM 850, on demand at kfuo.org,and on your podcast app ...
MicroRNA regulation of cell lineages in mouse and human embryonic stem cells. Cell Stem Cell. 2008;2:219-229. [PubMed] [DOI] [ ... Cells and cell culture. The murine embryonic stem cell line ES-D3 was originally from ATCC and maintained in "feeder free" ... MiR-301a promotes embryonic stem cell differentiation to cardiomyocytes. World J Stem Cells 2019; 11(12): 1130-1141 ... MiR-301a promotes embryonic stem cell differentiation to cardiomyocytes. World J Stem Cells 2019; 11(12): 1130-1141 [PMID: ...
What are embryonic stem cells? Embryonic stem cells (ESCs) are stem cells that have been taken from the inner cell mass of a ... What are adult stem cells? The term adult stem cells simply refers to any non-embryonic stem cell, whether taken from a fetus, ... What is a stem cell line?. A stem cell line is a family of constantly dividing cells, the product of a single group of stem ... Adult stem cells are sometimes referred to as somatic stem cells to differentiate them from human germ cells, sperm cells and ...
They have the ability to become any cell type in the body.   ... Embryonic stem cells. Stem cells derived from an early embryo. ... They have the ability to become any cell type in the body. ... Stem cells derived from an early embryo. ...
Will embryonic stem cells ever be used to treat human diseases? Why not use adult stem cells instead? The focus of the media ... and the public has almost exclusively been on these issues but the value of embryonic stem cells, to this point in time, lies ... Several controversies surround the use of human embryonic stem cells: Is it ethical to use them? ... Several controversies surround the use of human embryonic stem cells: Is it ethical to use them? Will embryonic stem cells ever ...
During the past year we have identified the folding patterns of human embryonic stem cells to iPS cells derived from human B ... Next the interactome of the iPS cells was determined and compared to that of human embryonic stem cells. Using an ensemble of ... During the past three years we have identified the folding patterns of human embryonic stem cells to iPS cells derived from ... The developmental progression of embryonic stem cells into specialist cell types involves the activation of lineage-specific ...
Bioprocess Development for the Expansion of Embryonic Stem Cells. Written By. Megan M. Hunt, Roz Alfred, Derrick E. Rancourt, ... Embryonic Stem Cells Basic Biology to Bioengineering Edited by Michael S. Kallos ... Embryonic Stem Cells Basic Biology to Bioengineering Edited by Michael S. Kallos ... Chapter 6 Synthetic Surfaces for Human Embryonic Stem Cell C... By Andrei G. Fadeev and Zara Melkoumian ...
Human embryonic stem cell (hESC)-derived MSCs are an alternative to adult MSCs that can circumvent issues regarding scalability ... This study represents an important step in the development of a commercially scalable and efficacious cell therapy for SLE/LN. ... the inability to manufacture large quantities of functional cells from a single donor as well as donor-dependent variability in ... BWF1 lymphocytes decreased lymphocyte secretion of TNFα and IL-6 and enhanced the percentage of putative regulatory T cells. ...
Posted in Breaking News, Pro Life , Tagged adult stem cells, embryonic stem cells ShareThis ... announced to a stunned audience that due to advances in adult stem cell technology, the debate over embryonic stem cells "is ... Posted in Breaking News , Tagged embryonic stem cells, iPS cells, Michael J. Fox ShareThis ... Posted in Breaking News, Pro Life , Tagged Elio Sgrecca, embryonic stem cells, Geron Corp, GRNOIPC1 ShareThis ...
Human Embryonic Stem (hES) cell research has met with a mixed reception internationally, but in the UK remains a significant ... Franklin, Sarah (2006) Embryonic economies: the double reproductive value of stem cells. Biosocieties, 1 (1). pp. 71-90. ISSN ... Management of what is called the national embryo supply in the UK involves new forms of governance at the IVF-Stem cell ... This article explores the question of embryo donation to stem cell research from the perspective of the increasing proximity of ...
Rescattering effects in the 3π system in the A1 region are studied with a method, which fulfils unitarity and has the proper analytic structure. Fairly small effects are obtained which confirm the result found in amplitude analyses, neglecting rescattering corrections, that the phases of the JP = 1+ amplitudes vary only very little over the A1 region. Similar results hold for the Q enhancement ...
Embryonic stem cells are derived from very early embryos called blastocysts. ... What are embryonic stem cells, where do they come from and what are researchers learning? ... These laboratory-grown cells are called embryonic stem (ES) cells.. Embryonic stem cells can make copies of themselves and make ... Cell and Gene Fundamentals Embryonic Stem Cells. Embryonic stem cells have captured the imagination of scientists and non- ...
Gary Friedman of the New Jersey Stem Cell Research and Education Foundation explained how successful stem cell therapies will ... He reiterated that the Catholic Church does not oppose stem cell research, but advocates research on non-embryonic cells that ... Tangretti said embryonic stem cell research is confusing; there are many scientific and moral questions to consider. He hoped ... Ethical considerations of embryonic stem cell research were discussed by Fr. Tadeusz Pacholczyk of the National Catholic ...
The surgical procedure for delivery of embryonic stem cell-derived endothelial cells to the ischemic hindlimb is demonstrated, ... Endothelial Cell Co-culture Mediates Maturation of Human Embryonic Stem Cell to Pancreatic Insulin Producing Cells in a ... Endothelial Cell Co-culture Mediates Maturation of Human Embryonic Stem Cell to Pancreatic Insulin Producing Cells in a ... Embryonic Stem Cell-Derived Endothelial Cells for Treatment of Hindlimb Ischemia. Article DOI: 10.3791/1034 • 09:11 min January ...
Noggle, S.A., D. Weiler, B.G. Condie (2006) Notch signaling is inactive but inducible in human embryonic stem cells. Stem Cells ... Differentiation of embryonic stem cells to clinically relevant populations: lessons from embryonic development. Cell 132: 661- ... Portrayal of the Notch System in Embryonic Stem Cell-Derived Embryoid Bodies Subject Area: Further Areas , Pathology and Cell ... Integrins regulate mouse embryonic stem cell self-renewal. Stem Cells 25: 3005-3015. ...
2010 July CBR Communique - CBR Challenges UC Irvines Embryonic Stem Cell Research. ...
Mouse embryonic stem (ES) cells are pluripotent cells, meaning that they can give rise to all tissues in the body. This has ... ES cells have been an invaluable resource for advancing fundamental understanding of global transcriptional and epigenetic ... We disproved past misconceptions in the field about the role of Yap1 concerning its function in ES cell self-renewal, showing ... Consistent with previous observations of repressive role of Rbpj, Rbpj serves as a repressor of ES cell core factors in the ...
Embryonic Stem Cell Marker) Recombinant Monoclonal (SOX2/4267R), Catalog # 6657-RBM7-P1. Tested in Immunohistochemistry ( ... positive regulation of cell-cell adhesion forebrain development somatic stem cell population maintenance tissue regeneration ... SOX2 (Embryonic Stem Cell Marker) Antibody (6657-RBM7-P1) in IHC (P) IHC analysis of formalin-fixed, paraffin-embedded human ... SOX2 (Embryonic Stem Cell Marker) Recombinant Rabbit Monoclonal Antibody (SOX2/4267R). View all (81) SOX2 antibodies ...
Embryonic stem cells are pluripotent cells derived from embryonic tissue in a process that usually results in the destruction ... The ban on funding did not apply to stem cells derived from adult tissue. ... The move was celebrated by researchers hoping to use such cells for research, but it is likely that the decision will be ... 29, 2011, a federal appeals court has lifted a ban on federal funding for embryonic stem cell (ESC) research. ...
The hallmark of embryonic stem (ES) cells is their ability for self-renewal (capability of unlimited cell division without the ... The hallmark of embryonic stem (ES) cells is their ability for self-renewal (capability of unlimited cell division without the ... Pfisterer, Iris (2007): The role of the PeBoW-complex in ribosome biogenesis and proliferation of mouse embryonic stem cells. ... The role of the PeBoW-complex in ribosome biogenesis and proliferation of mouse embryonic stem cells ...
Assembly of embryonic and extra-embryonic stem cells to mimic embryogenesis in vitro. Add to your list(s) Download to your ... Assembly of embryonic and extra-embryonic stem cells to mimic embryogenesis in vitro ...
Tools and Resources for Human Embryonic Stem Cell Research in the Nervous System (Neuroscience Blueprint) NOT-DC-07-001. NIH ... Notice of Extension for Request for Information (RFI): Tools and Resources for Human Embryonic Stem Cell Research in the ... RFI to determine how best to accelerate research directed toward targeted differentiation of human embryonic stem cells (hESCs ... into specific neuronal and glial cell types. Responses to this RFI should be focused on application of hESC biology to specific ...
... and patient groups appealed the European parliament on Friday to maintain European Union funding for embryonic stem cell ... Advanced Cell Technology: Embryonic Stem Cell Retinal Implants Safe. Stem Cells "Trick" the Immune System to Accept Mismatched ... for stem cell storage is displayed in front of a microscopic photograph showing a human embryonic stem cell at the UK Stem Cell ... embryonic and fetal stem cells. Embryonic stem cells are controversial because they involve harvesting embryos that are just a ...
... capable of generating all cell types in the body - could be used as the lego bricks to build tissue constructs, larger ... Scientists have developed a 3-D printing method capable of producing highly uniform blocks of embryonic stem cells. ... Scientists have developed a 3-D printing method capable of producing highly uniform blocks of embryonic stem cells. by ... Citation: Scientists have developed a 3-D printing method capable of producing highly uniform blocks of embryonic stem cells ...
Mammary gland development, Embryonic mammary stem cells, Adult mammary stem cells, Lineage tracing ... STEM CELLS AND REGENERATION, 25 July 2018 Neutral lineage tracing of proliferative embryonic and adult mammary stem/progenitor ... Embryonic cells contribute directly to the quiescent stem cell population in the adult mouse mammary gland ... Lgr5 is a marker for fetal mammary stem cells, but is not essential for stem cell activity or tumorigenesis ...
US-2014112891-A1 chemical patent summary.
  • Eggan, Melton and their colleagues decided to pursue their alternative route after other researchers had shown that genetic reprogramming can occur when mouse somatic cells are fused to mouse embryonic stem cells. (news-medical.net)
  • Mouse embryonic stem (ES) cells are pluripotent cells, meaning that they can give rise to all tissues in the body. (utexas.edu)
  • Dermis is formed approximately at E11 of mouse embryonic development. (lifemapsc.com)
  • In this study, we have ascertained the presence and functionality in mouse embryonic stem cells (ESCs) of members of the endocannabinoid system that have been proposed as possible modulators of the survival and differentiation of various type of stem cells. (univaq.it)
  • Ten-Eleven Translocation Ablation Impairs Cardiac Differentiation of Mouse Embryonic Stem Cells. (bvsalud.org)
  • physiologically based animals because a mouse embryonic stem cell line is used. (cdc.gov)
  • the EST, which assesses the effects of compounds on the differentiation of mouse embryonic stem cells into contracting cardiomyocytes, can be used to rank the potency of chemicals within a series of alkoxyacetic acid metabolites formed from The implementation of the European REACH (Registration, glycol ethers. (cdc.gov)
  • This knowledge can be used to model and understand developmental disorders or diseases that arise during early embryonic development. (nyscf.org)
  • Finally, genetic studies in mice show that Dpy30 is also necessary to maintain pluripotency in the pregastrulation embryo, thereby confirming the existence of similar regulations in vivo during early embryonic development. (ox.ac.uk)
  • Monkeys have served as one of the most valuable models for understanding DNA methylation dynamics during early embryogenesis in human due to their similarities in genetics and early embryonic development 17 , 18 . (nature.com)
  • Embryonic stem cells (ESCs), derived from the blastocyst stage of early mammalian embryos, are distinguished by their ability to differentiate into any embryonic cell type and by their ability to self-renew. (wikipedia.org)
  • Embryonic stem cells of the inner cell mass are pluripotent, meaning they are able to differentiate to generate primitive ectoderm, which ultimately differentiates during gastrulation into all derivatives of the three primary germ layers: ectoderm, endoderm, and mesoderm. (wikipedia.org)
  • When provided with the appropriate signals, ESCs initially form precursor cells that in subsequently differentiate into the desired cell types. (wikipedia.org)
  • According to a 2002 article in PNAS, "Human embryonic stem cells have the potential to differentiate into various cell types, and, thus, may be useful as a source of cells for transplantation or tissue engineering. (wikipedia.org)
  • Sun's method prodded human embryonic stem cells to differentiate into neural stem cells, the cells that give rise to neurons. (sciencedaily.com)
  • Using the same techniques to prod the two embryonic stem cells lines to differentiate, Sun found that one line had a bias to become neurons that are found in the forebrain. (sciencedaily.com)
  • As stem cells within a developing human embryo differentiate within the cell, their capacity to diversify generally becomes more limited and their ability to generate many differentiated cell types also becomes more restricted. (erlc.com)
  • By learning how stem cells differentiate and become specialized, scientists hope to gain a better understanding of how cells in general work and what can go wrong. (erlc.com)
  • Adult stem cells are sometimes referred to as somatic stem cells to differentiate them from human germ cells, sperm cells and egg cells. (erlc.com)
  • Many areas of science use mouse ESCs to study how blastocysts grow into adults and to study what signals direct stem cells to differentiate into specialised cells. (eurostemcell.org)
  • Another challenging area is controlling exactly how ESCs differentiate into numerous specialised cell types. (eurostemcell.org)
  • They will multiply and differentiate extensively to make the many types of cells needed to form the entire animal. (eurostemcell.org)
  • Stem cells can self-renew and differentiate into multiple cell types. (ox.ac.uk)
  • Eventually, the cells begin to differentiate, taking on a certain function in a part of the body. (healthline.com)
  • Adult stem cells can't differentiate into as many other types of cells as embryonic stem cells can. (healthline.com)
  • They can differentiate into all types of specialized cells in the body. (healthline.com)
  • The breakthrough has created a way to "de-differentiate" the stem cells. (healthline.com)
  • In response to signals from the notochord , neural tube and surface ectoderm, the somites subdivide and differentiate to give rise to the embryonic structures of the dermomyotome , myotome and sclerotome . (lifemapsc.com)
  • The pluripotent stem cells differentiate further into cells commonly called multipotent stem cells. (biomedcentral.com)
  • Until recently it was considered a fact that, for example, hematopoietic stem cells did not have the potential to differentiate into cells of other types than the cells constituting the blood system. (biomedcentral.com)
  • Here, we show that embryonic stem cells differentiate into chondrocytes, which progressively develop into hypertrophic and calcifying cells. (uni-luebeck.de)
  • We explore the recently described metabolic surge event that occurs as pluripotency is lost and stem cells commit to differentiate. (conditionmed.org)
  • This is a time-sensitive RFI to determine how best to accelerate research directed toward targeted differentiation of human embryonic stem cells (hESCs) into specific neuronal and glial cell types. (nih.gov)
  • The ESCRO Committee's review shall be specific to the scientific and ethical issues presented by proposals to use human gametes, human embryos, human embryo models, and the development and study of human embryonic stem cells (hESCs) or human induced pluripotent stem cells (hIPSCs) and their pluripotent derivatives in covered research in particular research projects. (washington.edu)
  • The UW Institute for Stem Cell and Regenerative Medicine (ISCRM) has been established for the purpose of facilitating and encouraging basic research on hESCs to develop therapies and cures for human disease. (washington.edu)
  • Here, we use human embryonic stem cells (hESCs) to show that the Activin-SMAD2/3 signaling pathway cooperates with the core pluripotency factor NANOG to recruit the DPY30-COMPASS histone modifiers onto key developmental genes. (ox.ac.uk)
  • Our results reveal the mechanisms by which extracellular factors coordinate chromatin status and cell fate decisions in hESCs. (ox.ac.uk)
  • We studied human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) measuring the SNPs and CNVs with Affymetrix SNP 6 microarrays and expression values with Affymetrix Exon microarrays. (biomedcentral.com)
  • Cell replacement using human embryonic stem cells (hESCs) derivatives may offer new therapeutic opportunities to replace degenerated neurons and repair damaged circuits. (lu.se)
  • However, they cannot form an organism because they are unable to give rise to extra embryonic tissue essential for normal development in the uterus. (biomedcentral.com)
  • The fertilized oocyte is totipotent, with resultant blastomeres capable of generating all three primary germ layers, ectoderm, mesoderm, and endoderm, in addition to the extra embryonic tissues. (conditionmed.org)
  • Human embryos reach the blastocyst stage 4-5 days post fertilization, at which time they consist of 50-150 cells. (wikipedia.org)
  • Isolating the inner cell mass (embryoblast) using immunosurgery results in destruction of the blastocyst, a process which raises ethical issues, including whether or not embryos at the pre-implantation stage have the same moral considerations as embryos in the post-implantation stage of development. (wikipedia.org)
  • Currently, embryos left over from infertility treatments are the only source of human embryonic stem cells. (sciencedaily.com)
  • But it also plays a much more mundane role in regular cell development, and the formation of blood cells and the cells that form the spinal cord in later-stage embryos. (sciencedaily.com)
  • The issue of research involving stem cells derived from human embryos is increasingly the subject of a national debate and dinner table discussions," said President George W. Bush in a 2001 speech announcing his policy on embryonic stem cell research. (erlc.com)
  • Where do the embryos for embryonic stem cells come from? (erlc.com)
  • Currently, all human embryonic stem cell lines in use today were created from embryos generated by IVF. (erlc.com)
  • Scientists announced this week that they have successfully produced embryonic stem cells by transferring the DNA of human skin cells into unfertilized human eggs to produce embryos, a technique the Church considers to be an abuse of human life. (womenofgrace.com)
  • Management of what is called the 'national embryo supply' in the UK involves new forms of governance at the 'IVF-Stem cell Interface', where questions about the provenance of donated embryos, including the ethics of their sourcing, are at a premium. (lse.ac.uk)
  • They are made from cells found in very early human embryos, called blastocysts. (eurostemcell.org)
  • A gene for a green fluorescent protein was inserted into the genomes of stem cells, which were then injected into macaque embryos grown for around four days in vitro. (planer.com)
  • As Wisconsin observed the 10-year anniversary of James Thomson's embryonic stem (ES) cell discovery, some wonder whether the ensuing controversy over the destruction of human embryos has been worthwhile. (wtnnews.com)
  • The cost seems to be small, experimentation with stem cells derived from "spare" embryos that are no longer needed or wanted for in vitro fertilization. (jcrelations.net)
  • Earlier this week, the British House of Commons voted by a large majority the amendments for Human Fertilization and Embryonic Research Act which allows scientists to produce human-animal hybrid embryos for stem cell research. (battlingforhealth.com)
  • Thanks to advances in stem cell technology since then, scientists are now able to create models of human embryos that can provide a rare insight into the earliest stages of life. (nyscf.org)
  • Dr. Wu's peri-gastruloids contain cells found in embryos as well as those found outside embryos that help them develop. (nyscf.org)
  • These embryos are not viable, as they still lack trophoblasts (cells found in the placenta that nourish embryos), but can help provide a glimpse into critical stages of development that could not be previously studied. (nyscf.org)
  • Embryonic stem cells come from human embryos that are three to five days old. (healthline.com)
  • In 1-cell and 2-cell embryos Dnmt1s is derived from the oocyte, whereas from the 2-cell stage onward the embryo starts to synthesize its own Dnmt1s 8 . (nature.com)
  • Furthermore, due to ethical and legal concerns, very limited techniques can be applied to human embryos to validate some of significant conclusions drawn from descriptive studies regarding human embryonic development. (nature.com)
  • Recent studies have isolated distinct cell populations from infantile hemangiomas that display properties equivalent to aberrant progenitor cells, suggesting that, in addition to malignant tumors, benign tumors may also contain a stem cell-like component. (medscape.com)
  • emGFP) expression under the control of Nkx2.5 promoter as marker for cardiac progenitor cells , we discovered that Tet1 and Tet2 depletion significantly impaired mESC -to-cardiac progenitor differentiation. (bvsalud.org)
  • 1983) and the multipotent progenitor cells from fetal disease (Bjorklund and Lindvall, 2000). (lu.se)
  • Second, stem cells may prove to be an indispensable source of transplantable cells and tissues for repair and regeneration. (erlc.com)
  • Cells Tissues Organs (2011) 193 (4): 239-252. (karger.com)
  • Researchers are learning how cells assemble into complex tissues, such as the layers of the brain, by attempting to grow primitive organs in the lab. (eurostemcell.org)
  • In this study, we have provided strong evidence that naïve monkey pluripotent stem cells possess the capability of differentiating in vivo into all the various tissues composing a monkey body,' co-author Professor Miguel Esteban from the University of Chinese Academy of Sciences, Guangzhou, China told Nature. (planer.com)
  • This male macaque exhibited organs with a mixture of both sets of cells, including green eyes and fingertips, demonstrating tissues featuring a high proportion of cells derived from the injected stem cells. (planer.com)
  • Publishing their results in Cell, the authors analysed 26 different tissues, showing that donor cells accounted for 21 to 92 percent of the constituent cells, with an average incidence of 67 percent. (planer.com)
  • We have a very high level of contribution, with the donor cells forming a big part of the tissues (and) complex structures all over the monkey body. (planer.com)
  • But he also said that even if they never make it into the clinic, ES cells would profoundly affect the future of medicine because they provide laboratory access to human tissues that had been inaccessible before. (wtnnews.com)
  • Thomson also explained that the different cell types that can be derived from ES cells enable researchers to directly test new drugs on different human tissues. (wtnnews.com)
  • ES cell technology therefore promises to provide tissues on which to test and eliminate potentially toxic drugs much earlier in the development pipeline, potentially saving billions in drug development costs, according to the FDA. (wtnnews.com)
  • Thomson and others from UW-Madison founded Cellular Dynamics International to grow different tissues from ES cells. (wtnnews.com)
  • This knowledge can be applied to improve regenerative medicine approaches, such as generating specific cell types or tissues for transplantation or repairing damaged organs," said lead author Lizhong Liu, PhD , Assistant Instructor of Molecular Biology in the Wu lab. (nyscf.org)
  • These stem cells come from developed organs and tissues in the body. (healthline.com)
  • and b) how do stem cells in different tissues coordinate their functions for the fish to maintain its shape during permanent growth? (uni-heidelberg.de)
  • A few of the cells in the inner cell mass will develop into the foetus, whereas the rest will form the placenta and other supporting tissues needed for foetal development in the uterus. (biomedcentral.com)
  • Researchers hope to use these cells to grow healthy tissue to replace injured or diseased tissues in the human body. (medlineplus.gov)
  • Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. (wikipedia.org)
  • Dr. Katherine High of the Center for Cellular and Molecular Therapeutics at the Children's Hospital of Philadelphia was the lone speaker supporting embryonic research. (pacatholic.org)
  • Mechanistically, in vitro data support these findings, as co-culture of hESC-MSCs with lipopolysaccharide (LPS)-stimulated BWF1 lymphocytes decreased lymphocyte secretion of TNFα and IL-6 and enhanced the percentage of putative regulatory T cells. (nature.com)
  • We portrayed the Notch system in embryonic stem cell (ESC)-derived embryoid bodies (EBs) differentiating under the standard protocols used to assess yolk sac (YS) hematopoiesis in vitro. (karger.com)
  • A high expression of Pes1, Bop1 and WDR12 was observed in ES cells, which strongly decreased during in vitro differentiation. (uni-muenchen.de)
  • We used in vitro differentiation of embryonic stem cells through embryoid bodies as a model to analyze chondrogenic and osteogenic differentiation because embryonic stem cells recapitulate early embryonic developmental phases during in vitro differentiation. (uni-luebeck.de)
  • We discuss what is known about the distinct metabolic states captured in vitro by the 2-cell-like, naïve, blastocyst-like, formative, and primed states of pluripotency. (conditionmed.org)
  • 2019). Akin to the dynamic nutrient requirements of the developing embryo, discrete in vitro cell states have distinct metabolic profiles (Zhou et al. (conditionmed.org)
  • It is only through understanding embryonic metabolism and development that we can derive and maintain different in vitro stem cell states for disease modeling and therapies. (conditionmed.org)
  • To determine how the pathogenesis of these viruses differs, we compared their ability to induce disease in mice and replicate and induce cell death in vitro. (cdc.gov)
  • In vitro toxicity data of these metabolites derived in the development of validated and accepted in vitro and in silico embryonic stem cell test were used as input in the PBK model to extrapolate in vitro concentration-response curves to predicted approaches is urgently needed. (cdc.gov)
  • In addition to their potential in regenerative medicine, embryonic stem cells provide a possible alternative source of tissue/organs which serves as a possible solution to the donor shortage dilemma. (wikipedia.org)
  • For that reason, many researchers believe stem cells offer promise for creating populations of specialized cells that can be used to rejuvenate organs, such as the pancreas or heart, that are damaged by disease or trauma. (news-medical.net)
  • Mouse ESCs are being used to learn about how the body develops, from early embryonic stages to the formation of complex organs. (eurostemcell.org)
  • Besides CDI, Geron, and San Francisco's VistaGen Therapeutics also use ES cells to produce cells from the heart, pancreas, liver, and other organs for similar purposes. (wtnnews.com)
  • We are particularly interested in learning how organs can adapt to the changing organismal size , with a focus on the molecular mechanisms for stem cell coordination within and among organs. (uni-heidelberg.de)
  • We follow stem cell derived lineages in different organs to learn whether fish use the same stem cells to maintain homeostasis replacemente and to drive growth, or if they have dedicated populations for each feature. (uni-heidelberg.de)
  • Since fish grow during their entire post-embryonic life, their organs have to adapt to an increasing body size. (uni-heidelberg.de)
  • The fusion causes the adult cells to undergo genetic reprogramming, which results in cells that have the developmental characteristics of human embryonic stem cells. (news-medical.net)
  • The developmental progression of embryonic stem cells into specialist cell types involves the activation of lineage-specific programs of gene expression and the silencing of genes involved in maintaining pluripotency. (ca.gov)
  • Thus, they retain control of the ES cells and the developmental process, while providing a renewable stream of cellular tools that researchers can purchase. (wtnnews.com)
  • Human embryonic development is a critical component of human life, and is a stage during which many conditions - including developmental disorders, birth defects, genetic disorders, and many neurological disorders - can begin to take form. (nyscf.org)
  • However, robust and large-scale genome-wide reprogramming of DNA methylome occurs during two critical developmental processes: (1) development of primordial germ cells and (2) pre-implantation embryogenesis. (nature.com)
  • The clonal analysis confirmed that the chondrogenic cells change their developmental fate at least into the adipogenic lineage. (uni-luebeck.de)
  • Due to their plasticity and potentially unlimited capacity for self-renewal, embryonic stem cell therapies have been proposed for regenerative medicine and tissue replacement after injury or disease. (wikipedia.org)
  • In tissue engineering, the use of stem cells are known to be of importance. (wikipedia.org)
  • Adult tissue-derived mesenchymal stromal cells (MSCs) are showing promise in clinical trials for systemic lupus erythematosus (SLE). (nature.com)
  • Embryonic stem cells are pluripotent cells derived from embryonic tissue in a process that usually results in the destruction of the embryo. (biopharminternational.com)
  • The ban on funding did not apply to stem cells derived from adult tissue. (biopharminternational.com)
  • Researchers used stem cells obtained from the embryonic tissue of cynomolgus monkeys, a type of macaque commonly used in genetics research because of their similarity to humans. (planer.com)
  • The expression and regulation of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) in neuroectodermal precursor cells is undocumented. (uea.ac.uk)
  • This means they can potentially produce new cells for any organ or tissue. (healthline.com)
  • Several genome-wide studies have reported genomic variants that correlate with gene expression levels in various tissue and cell types. (biomedcentral.com)
  • International bi-monthly journal of cell signaling, tissue protection, and translational research. (conditionmed.org)
  • The blastocyst comprises the inner cell mass (ICM), which gives rise to the three primary germ layers and consequently the fetus, and the trophectoderm (TE), which gives rise to the extraembryonic and placental tissue. (conditionmed.org)
  • Cloning describes the processes used to create an exact genetic replica of another cell, tissue or organism. (medlineplus.gov)
  • The cells are being studied to be used as clinical therapies, models of genetic disorders, and cellular/DNA repair. (wikipedia.org)
  • Considerable time and effort has been spent in developing targeted therapies to fight SLE, yet only one therapy, belimumab (Benlysta), a monoclonal antibody targeting B cell-activating factor, or BAFF, has been approved for the treatment of SLE in the last half-century 16 . (nature.com)
  • Ethical adult stem cell research is succeeding and yielding therapies that are healing people now. (pacatholic.org)
  • Dr. Gary Friedman of the New Jersey Stem Cell Research and Education Foundation explained how successful stem cell therapies will be more important as the aging American population puts a strain on our health care system. (pacatholic.org)
  • For example, stem cell therapies might help the people on the rapidly growing organ transplant list. (pacatholic.org)
  • This is a momentous day-not only for science, but for the hopes of thousands of patients and their families who are relying on NIH-funded scientists to pursue life-saving discoveries and therapies that could come from stem cell research. (biopharminternational.com)
  • Michael West is more optimistic than Thomson that ES cell-based therapies soon will happen. (wtnnews.com)
  • It is the belief of many scientists, lawmakers, as well as patients that the key to future therapies that can cure diseases - from cardiovascular disorders to cancer - lie in stem cell research. (battlingforhealth.com)
  • Prior to 2015, China lacked a clear regulatory framework in this area that led to the spread of many untested therapies and the emergence of stem cells on the black market. (scienews.com)
  • To establish protocols for the safe and efficient differentiation of healthy cells for therapies, we must develop a better understanding of the dynamic continuum of metabolic states that span pluripotency and differentiation, and how to influence them. (conditionmed.org)
  • The scientists knew that if their studies were successful, it would provide the research community with a new option for producing reprogrammed cells using embryonic stem cells, which are more plentiful and easier to obtain than unfertilized human eggs. (news-medical.net)
  • Though not intended to be an exhaustive explanation of this important topic, we believe this will help to clarify and explain the questions most frequently asked about embryonic stem cell research. (erlc.com)
  • Why are stem cells so important to research? (erlc.com)
  • There are two main reasons stem cells are of interest to both scientific and medical research. (erlc.com)
  • Funding for stem cell research in two of the most liberal states in the nation - California and Maryland - appears to be shifting away from embryonic to adult stem cells. (womenofgrace.com)
  • Human Embryonic Stem (hES) cell research has met with a mixed reception internationally, but in the UK remains a significant national priority. (lse.ac.uk)
  • This article explores the question of embryo donation to stem cell research from the perspective of the increasing proximity of IVF and hES cell derivation, using a model of 'double reproductive value' to explore what forms of exchange and flow are occurring, and how these are defined and negotiated in the context of a national hES cell coordination network of practitioners. (lse.ac.uk)
  • In July, President George Bush vetoed a bill that would have provided federal funding for embryonic stem cell research. (pacatholic.org)
  • Stephen Webster, CEO of Nureonyx, discussed the business opportunities of stem cell research. (pacatholic.org)
  • She contends that without state funding Pennsylvania might be a "follower" instead of a "leader" in stem cell research which could hurt the Commonwealth's economy. (pacatholic.org)
  • Ethical considerations of embryonic stem cell research were discussed by Fr. (pacatholic.org)
  • He reiterated that the Catholic Church does not oppose stem cell research, but advocates research on non-embryonic cells that does not destroy human life. (pacatholic.org)
  • Expect embryonic stem cell research to be on the agenda. (pacatholic.org)
  • This has catalyzed research in both early embryogenesis as a model system for mammalian development as well as regenerative medicine as a renewable source of unspecialized cells which can be converted into nearly any cell type required by a patient. (utexas.edu)
  • 29, 2011, a federal appeals court has lifted a ban on federal funding for embryonic stem cell (ESC) research. (biopharminternational.com)
  • The move was celebrated by researchers hoping to use such cells for research, but it is likely that the decision will be appealed. (biopharminternational.com)
  • The case began when a lawsuit was brought against the National Institutes of Health (NIH) by Dr. James Sherley and Dr. Theresa Deisher, scientists opposed to embryonic stem cell research. (biopharminternational.com)
  • The scientists also claimed that funding embryonic stem cell research hurt their ability to receive federal funding for their own research using adult stem cells. (biopharminternational.com)
  • In August 2010, a district court agreed with the plaintiffs that embryonic stem cell research violated federal law and blocked funding, but a three-judge appeals court temporarily lifted the ban in September. (biopharminternational.com)
  • The issue is whether that law's restrictions apply to research conducted on stem cell lines that had been developed without federal funding. (biopharminternational.com)
  • NIH has interpreted the law narrowly, and argued that creating embryonic stem cells is not the same as using lines created without federal funding for research purposes. (biopharminternational.com)
  • CDI grows the heart cells in-house and then sells them as research tools. (wtnnews.com)
  • Clearly, ES cells as drug testing and research tools is a growing international market. (wtnnews.com)
  • Medical ethicists from my Roman Catholic religious tradition face a dilemma when investigating the morality of human embryonic stem cell research. (jcrelations.net)
  • This statement shows that, from a Roman Catholic point of view, the starting point for reflection on the ethics of embryonic stem cell research does not begin with stem cell research in itself nor even with the social good that comes about from the possible results of such research. (jcrelations.net)
  • Understood in this way, the moral context of embryonic stem cell research from a Roman Catholic point of view involves the acceptance of the idea that the benefits given to so many in society come through the destruction of the weakest and most vulnerable forms of life. (jcrelations.net)
  • Part of why NYSCF was founded was to offer scientists a private, philanthropy-driven funding source for stem cell research, which at the time could only be done using embryonic stem cells. (nyscf.org)
  • UW's policy governing human embryo and human embryonic stem cell research has been changed to include oversight of research involving human embryo models and human gametes. (washington.edu)
  • However, more research is needed to help understand the potential uses of amniotic fluid stem cells. (healthline.com)
  • With them a new set of rules for the use of embryonic stem cells in China and, possibly, will begin a new era of research around the world. (scienews.com)
  • Cueto engaged in stem cell research and is in the Committee of the Central government, which approved the test. (scienews.com)
  • Biologist stem cells the SCRIPPS research Institute Jeanne Loring believes that stem cells in the treatment of Parkinson's disease are specialized enough to achieve the intended results. (scienews.com)
  • And if he and his team are right, will begin a new era of stem cell research. (scienews.com)
  • Within this context, research involving stem cells are on the agenda of several academic articles and major newspapers and magazines around the world. (bvsalud.org)
  • We followed different mediators along their deviations, in order to produce a report based on the analysis of current bioethical controversies involving, specifically, embryonic stem cell research. (bvsalud.org)
  • 5. In 2001, France and Germany requested the United Nations General Assembly to develop international conventions on human reproductive cloning, therapeutic cloning and research on stem cells. (who.int)
  • Somatic-cell nuclear transfer, the technique by which Dolly was created, was first used 40 years ago in research with tadpoles and frogs. (who.int)
  • Great Iranian Muslim scholars netics, stem cell research, and organ trans- laid huge emphasis on teaching and practis- plantation are some of the medical issues ing ethics. (who.int)
  • Andreas' research focuses on generating brain cells, specifically interneurons, in the lab, which has significant implications for the study of neurodegenerative and neuropsychiatric disorders. (lu.se)
  • Combining cell biology and electrophysiology, his work has the potential to create personalized disease models for future research. (lu.se)
  • Retinoblastoma proteins that inhibit the transcription factor E2F until the cell is ready to enter S phase are hyperphosphorylated and inactivated in ESCs, leading to continual expression of proliferation genes. (wikipedia.org)
  • We've demonstrated that we don't have to manipulate the pluripotent genes to get to the ground state, but rather that we can block all other options of where the cell 'wants' to go. (sciencedaily.com)
  • Sun and her team confirmed that the two embryonic stem cell lines were different through gene expression analysis -- neurons that perform different functions in different parts of the brain express different genes. (sciencedaily.com)
  • Furthermore, Eggan noted that genetic analyses of the fused cells revealed that the somatic cell genes characteristic of adult cells had all been switched off, while those characteristic of embryonic cells had been switched on. (news-medical.net)
  • With the exception of a few genes one way or the other -- which is perhaps because these cells are now tetraploid -- the hybrid cells are indistinguishable from human embryonic stem cells," he said. (news-medical.net)
  • We found that a large fraction of genes were differentially localized in human thymocytes derived from embryonic stem cells versus human myeloid cells. (ca.gov)
  • Chimeras can pass on genes from embryonic stem cells to their offspring. (eurostemcell.org)
  • Researchers can precisely alter the genes of ES cells in the lab, put the cells back into blastocysts, and produce new mice that contain the modified genes. (eurostemcell.org)
  • Scientists use genetically altered mice made from ES cells to study genes involved in many human diseases. (eurostemcell.org)
  • This screen is capable of analyzing the expression of 48 genes simultaneously across dozens of different samples, and our gene list covers all three germ layers that arise during normal embryonic development, the trophectoderm, and epigenetic regulators of chromatin status. (utexas.edu)
  • Our signature-based screen established several categories of genes based on their comparative functions during the differentiation of ES cells. (utexas.edu)
  • A chimeric monkey has been created using embryonic stem cells with two different sets of genes, a new study has demonstrated. (planer.com)
  • Our results revealed altogether 217 genes and 584 SNPs whose genomic alterations affect the transcriptome in the same cells. (biomedcentral.com)
  • Our results revealed that in the human pluripotent stem cells, the expression values of several genes, transcripts and exons were affected due to the genomic variation. (biomedcentral.com)
  • Both methods have contributed extensively to our current knowledge on the lineage relation of differentiated cells during embryogenesis, the potential of stem cell populations to generate or re-generate missing cell types, and the cell autonomous or non cell autonomous effects of many genes during development and disease. (uni-heidelberg.de)
  • Finally, we document that the stimulation of ESCs by methanandamide, a nonhydrolysable analog of anandamide, does not lead to overt alteration of the expression of Oct3/4, Nanog, and Cdx2, genes that are involved in early cell fate in the preimplantation embryo and stemness, or of the expression patterns of Brachyury and Hnf4, genes that are used as late markers of lineage differentiation capability of ESC-derived embryoid bodies. (univaq.it)
  • Promoters of genes associated with oxidative phosphorylation are preferentially remethylated at the 8-cell stage, suggesting that this mode of energy metabolism may not be favored. (nature.com)
  • Scientists were initially interested in somatic-cell nuclear transfer as a means of determining whether genes remain functional even after most of them have been switched off as the cells in a developing organism assume their specialized functions as blood cells, muscle cells, and so forth. (who.int)
  • The fact that the DNA of a fully differentiated (adult) cell could be stimulated to revert to a condition comparable to that of a newly fertilized egg and to repeat the process of embryonic development demonstrates that all the genes in differentiated cells retain their functional capacity, although only a few are active. (who.int)
  • Rapid cell division allows the cells to quickly grow in number, but not size, which is important for early embryo development. (wikipedia.org)
  • Stem cells also provide a model system in which researchers can study the causes of genetic disease and the basis of embryonic development. (news-medical.net)
  • Our assays showed that the hybrid cells, unlike adult cells, showed the development potential of embryonic stem cells," said Eggan. (news-medical.net)
  • All specialized cells arise originally from stem cells, and ultimately form a small number of embryonic cells that appear during the first few days of development. (erlc.com)
  • This study represents an important step in the development of a commercially scalable and efficacious cell therapy for SLE/LN. (nature.com)
  • Notch receptors and Notch ligands were detected in virtually all cells throughout EB development. (karger.com)
  • An immense amount has been learned about embryonic development and disease from creating 'chimera' mice with genetically modified ESCs. (eurostemcell.org)
  • The injected ES cells take part in the development of the foetus and the resulting pup is born with a mixture of cells, (a) from the host blastocyst and (b) cells that came from the injected ES cells. (eurostemcell.org)
  • SOX2 is an intronless gene encoding a member of the SRY-related HMG-box (SOX) family of transcription factors involved in the regulation of embryonic development and in the determination of cell fate. (thermofisher.com)
  • Gastrulation is a critical step in embryonic development in which cells begin to organize themselves into layers that will contain the basic plan for a future organism, but there are few ways to study this process in depth. (nyscf.org)
  • Scientists have already established stem cell models of gastrulation - the process of human development in which cells reorganize from a single layer to a 3D structure - but these models have lacked the diversity of cell types needed to more fully model complex development. (nyscf.org)
  • During the third week of human embryonic development, the paraxial mesoderm forms paired "balls" of mesoderm on either side of the neural groove. (lifemapsc.com)
  • We have generated several transgenic lines to explore how neuromasts are created after embryonic development (Development 144, 687-697), which are their cells of origin and which and how they integrate the signals from the environment to trigger organ formation. (uni-heidelberg.de)
  • There are different types of stem cells that best can be described in the context of normal human development [ 23 ]. (biomedcentral.com)
  • Here, we consider the metabolism of the early embryo through development, and look at the nutrient milieu within the developing stem cell niche. (conditionmed.org)
  • 2020). This places metabolism at the forefront of development and cell state decisions. (conditionmed.org)
  • The developing embryo, from which pluripotent stem cells originate, undergoes a series of dynamic metabolic transitions synchronized to its molecular development. (conditionmed.org)
  • Historically, lineage analysis in vertebrates was performed on entire populations of cells using either transplantation approaches or genetic tools like Cre/LoxP mediated recombination. (uni-heidelberg.de)
  • in 1956 and Till and McCulloch in 1961, demonstrating that lethally irradiated mice could be rescued with cells from freshly isolated bone marrow [ 10 ] and that BM cells formed spleen clonies (CFU-S) following transplantation to irradiated recipients [ 30 ], respectively. (biomedcentral.com)
  • Hematopoietic stem cell transplantation (HSCT) involves the intravenous infusion of hematopoietic stem cells in order to reestablish blood cell production in patients whose bone marrow or immune system is damaged or defective. (medscape.com)
  • There is an immense functional heterogeneity among stem cell within a population, considering proliferative capacity and differentiation potential. (uni-heidelberg.de)
  • Researchers are currently focusing heavily on the therapeutic potential of embryonic stem cells, with clinical use being the goal for many laboratories. (wikipedia.org)
  • No end believed to be good, such as the use of [embryonic] stem cells for the preparation of other differentiated cells to be used in what look to be promising therapeutic procedures, can justify [the destruction of embryonic life]. (jcrelations.net)
  • These findings further strengthen the view that standardized selection strategies will be necessary to obtain defined cell populations for therapeutic applications. (uni-luebeck.de)
  • Therapeutic cloning, which creates embryonic stem cells . (medlineplus.gov)
  • Conclusions: The data support the long-term therapeutic potential of ESC-derived human striatal progenitor grafts for the replacement of degenerated striatal neurons in HD and suggest that EE can effectively accelerate the maturation and promote the integration of human striatal cells. (lu.se)
  • Comparison of toxicity of benzene metabolite hydroquinone in hematopoietic stem cells derived from murine embryonic yolk sac and adult bone marrow. (cdc.gov)
  • In a surprising new finding, scientists have shown that mouse stem cells treated with the drug reverted to an 'embryonic' state. (sciencedaily.com)
  • It's the first time that scientists have shown they can get stem cells to revert to their original state by erasing specific labels called epigenetic markers. (sciencedaily.com)
  • Scientists were able to produce from human embryonic stem cells a highly pure, large quantity of functioning neurons that will allow them to create models of and study diseases such as Alzheimer's, Parkinson's, prefrontal dementia and schizophrenia. (sciencedaily.com)
  • SCNT involves transferring the nuclei of adult cells, called somatic cells, into oocytes in which scientists have removed the nuclei. (news-medical.net)
  • Scientists at Stanford University in California have been able to coax embryonic stem cells into becoming eggs and sperm, which could one day lead to the creation of children through entirely artificial means. (womenofgrace.com)
  • British scientists are hailing the recent creation of human sperm cells that they believe could revolutionize fertility treatment. (womenofgrace.com)
  • Embryonic stem cells have captured the imagination of scientists and non-scientists alike. (eurostemcell.org)
  • The immense value of this technique for science and medicine was recognized in 2007 when the Nobel Prize in Medicine was awarded to three scientists who pioneered the use of ES cells to create genetically modified mice . (eurostemcell.org)
  • This allows scientists to see what goes wrong with the specific cell types that cause Parkinson's and cardiovascular diseases, diabetes, and other maladies. (wtnnews.com)
  • Using human stem cells, scientists led by NYSCF - Robertson Stem Cell Investigator Jun Wu, PhD , of UT Southwestern Medical Center have developed an embryo model called 'peri-gastruloids' that can form many of the body's cell types. (nyscf.org)
  • Since stem cells have the ability to turn into various other types of cells, scientists believe that they can be useful for treating and understanding diseases. (healthline.com)
  • Scientists have recently discovered how to turn adult stem cells into pluripotent stem cells. (healthline.com)
  • To create iPSCs, scientists genetically reprogram the adult stem cells so they behave like embryonic stem cells. (healthline.com)
  • Scientists are hoping that the cells can be made from someone's own skin to treat a disease. (healthline.com)
  • These germ layers generate each of the more than 220 cell types in the adult human body. (wikipedia.org)
  • These cells are commonly termed embryonic germ (EG) cells because they are derived from primordial germ cells found at the genital ridges in developing fetuses. (biomedcentral.com)
  • Pluripotency distinguishes embryonic stem cells from adult stem cells, which are multipotent and can only produce a limited number of cell types. (wikipedia.org)
  • Pluripotency factors Oct4 and Nanog play a role in transcriptionally regulating the embryonic stem cell cycle. (wikipedia.org)
  • Writing in the journal Cell Stem Cell , the team reports that more than half of mouse epiblast stem cells treated with the drug reversed course within three days, and regained an embryonic "be anything" state, also called pluripotency. (sciencedaily.com)
  • Past attempts by other teams to restore pluripotency to mouse cells from the epiblast stem cell state have yielded far lower amounts, or non-viable cells. (sciencedaily.com)
  • The hallmark of embryonic stem (ES) cells is their ability for self-renewal (capability of unlimited cell division without the loss of pluripotency) as well as for differentiation into all cell types of the adult organism. (uni-muenchen.de)
  • These findings provide supporting evidence that enrichment for proteins involved in pluripotency is not restricted solely to malignant tumors as is suggested by the "stem cell theory of cancer", but additionally extends to common benign vascular tumors such as hemangiomas. (medscape.com)
  • In clonal cultures of chondrocytes isolated from embryoid bodies, additional mesenchymal cell types expressing adipogenic properties were observed, which suggests that the subcultured chondrocytes indeed exhibit a certain differentiation plasticity. (uni-luebeck.de)
  • abstract = "Evidence exists that cells of mesenchymal origin show a differentiation plasticity that depends on their differentiation state. (uni-luebeck.de)
  • ES cells have been an invaluable resource for advancing fundamental understanding of global transcriptional and epigenetic regulations, signaling pathways, and noncoding RNA in mammalian systems. (utexas.edu)
  • Other techniques can reprogram "adult" cells in the human body taken from skin, for example -- but the cells still carry baggage from their previous state. (sciencedaily.com)
  • It is more likely that the new technique will see immediate use in helping to accelerate understanding of how embryonic cells "reprogram" somatic cells to an embryonic state. (news-medical.net)
  • Pluripotent stem cells have shown promise in treating a number of varying conditions, including but not limited to: spinal cord injuries, age related macular degeneration, diabetes, neurodegenerative disorders (such as Parkinson's disease), AIDS, etc. (wikipedia.org)
  • If stem cells can be used to produce new and differentiated cells that are damaged because of disease (such as Parkinson's disease) or injury (e.g., spinal cord damage), it would transform regenerative medicine. (erlc.com)
  • In two new clinical trials in China will start to use embryonic stem cells for the treatment of Parkinson's disease and blindness. (scienews.com)
  • The studies surgeons in Zhengzhou, China, will uncover the skull of patients with Parkinson's disease and to introduce them embryonic stem cells in the brain. (scienews.com)
  • About 4 million immature embryonic neural cells will need to remove the debilitating symptoms of Parkinson's disease. (scienews.com)
  • Cell Therapy for Parkinson's Disease: What Next? (lu.se)
  • The process of cell maturation and specialization that would normally take place in the embryo stops. (eurostemcell.org)
  • Treatment of mouse NIH3T3 cells with 5FU, a potent inhibitor of rRNA maturation, confirmed an activation of this checkpoint, leading to weak induction of the tumor suppressor p53, induction of the Cdk-inhibitor p21, an increase in active, hypo-phosphorylated Rb, and to accumulation of cells in the G1- and S-phase with an increase of cells in G1-phase. (uni-muenchen.de)
  • MLL1 plays a key role in the uncontrolled explosion of white blood cells that's the hallmark of leukemia, which is why U-M researchers originally developed MM-401 to interfere with it. (sciencedaily.com)
  • Researchers previously had been able to produce neurons - the impulse-conducting cells in the brain and spinal cord - from human embryonic stem cells. (sciencedaily.com)
  • Researchers have developed a new technique for creating human embryonic stem cells by fusing adult somatic cells with embryonic stem cells. (news-medical.net)
  • In theory, researchers can induce embryonic stem cells to mature into a variety of specialized cells. (news-medical.net)
  • In the studies published in Science, the researchers combined human fibroblast cells with human embryonic stem cells in the presence of a detergent-like substance that caused the two cell types to fuse. (news-medical.net)
  • The researchers demonstrated that they had achieved fusion of the two cell types by searching the fused cells for two distinctive genetic markers present in the somatic fibroblast and stem cells. (news-medical.net)
  • The researchers were also able to further confirmed that fusion occurred by studying the chromosomal makeup of the fused cells. (news-medical.net)
  • The researchers also performed fusion experiments using pelvic bone cells as the somatic cells and a different human embryonic cell line, to demonstrate that their technique was not restricted to one adult cell type or embryonic cell line. (news-medical.net)
  • Researchers are learning how to create many different specialised cell types found in the body by exposing ESCs to different signalling molecules and growth conditions. (eurostemcell.org)
  • This will be a valuable information for other researchers interested in ES cell differentiation from various perspectives. (utexas.edu)
  • These cells will be excellent for doing gene expression studies and biochemical and protein analyses. (sciencedaily.com)
  • These findings were important since they provide new insights as to how such regulatory elements find each other with great speed, selectivity and specificity to induce lineage specific patterns of gene expression both in embryonic stem cells and differentiated progeny. (ca.gov)
  • Specificity Comments: SOX2 is required for stem cell maintenance in the central nervous system, and it also regulates gene expression in the stomach. (thermofisher.com)
  • These data indicate that the majority of the genome derived from that of human embryonic stem cells shows a similar pattern in chromatin folding as compared to that of iPS cells derived from human B cells but that they differ from each other in a subset of genomic regions. (ca.gov)
  • Differentiation is a complex process involving actions of ES cell core factors, lineage specific regulators, epigenetic modifications, and chromatin remodelers. (utexas.edu)
  • Activin/nodal signaling and NANOG orchestrate human embryonic stem cell fate decisions by controlling the H3K4me3 chromatin mark. (ox.ac.uk)
  • In conclusion, we show that chondrocytic cells are able to transdifferentiate into other mesenchymal cells such as osteogenic and adipogenic cell types. (uni-luebeck.de)
  • In humans, mice and other mammals, the embryo is a ball of approximately 100 cells at this stage. (eurostemcell.org)
  • All humans start out as only one cell. (healthline.com)
  • My lab is interested in understanding stem cells, a fascinating type of cell that can self-renew and is responsible to generate once and again the cells that we humans (and most other animals) lose on daily basis - skin cells, blood cells, intestine cells. (uni-heidelberg.de)
  • A recent study indicates that even adult humans might harbor cells resembling pluripotent embryonic stem cells. (biomedcentral.com)
  • 2002). In humans, SSEA4 is expressed by building the nervous system but also for their prospec- nonneural cells such as the erythrocytes (Kannagi et al. (lu.se)
  • These cells are multipotent, meaning they can give rise to several other differentiated and specialized cells of the body (for example, liver cells, kidney cells, brain cells). (erlc.com)
  • Examples of multipotent stem cells are those producing blood, nerve and muscle cells. (biomedcentral.com)
  • Multipotent stem cells are present in the adult individual as well as the fetus and umbilical cord. (biomedcentral.com)
  • The established dogma has however been challenged by recent findings suggesting that multipotent stem cells have a broader differentiation potential than previously thought. (biomedcentral.com)
  • Although several reports indicate an ability of multipotent stem cells to produce cells even outside their normal limits, most of these findings remain highly controversial. (biomedcentral.com)
  • These cells have been successfully used to treat children with blood cancers, such as leukemia, and certain genetic blood disorders. (healthline.com)
  • We combine these lines with a living toolkit to study stem cell lineages that relies on the generation of colourful (genetic) mosaics, and we named the toolkit Gaudi after the famous spanish architect. (uni-heidelberg.de)
  • 2. Nuclear transfer is a technique used to duplicate genetic material by creating an embryo through the transfer and fusion of a diploid cell in an enucleated female oocyte.2 Cloning has a broader meaning than nuclear transfer as it also involves gene replication and natural or induced embryo splitting (see Annex 1). (who.int)
  • if it implants and the pregnancy goes to term, the resulting individual will carry the same nuclear genetic material as the donor of the adult somatic cell. (who.int)
  • However, an animal created through this technique would not be a precise genetic copy of the source of its nuclear DNA because each clone derives a small amount of its DNA from the mitochondria of the egg (which lie outside the nucleus) rather than from the donor of cell nucleus. (who.int)
  • Using this type of direct conversion approach rather than making them from induced pluripotent stem cells, where they revert into a naïve state, helps to retain the epigenetic age of the patient in the generated interneurons. (lu.se)
  • This approach could become an alternative to somatic cell nuclear transfer (SCNT), a method that is currently used to produce human stem cells. (news-medical.net)
  • The long term goal for this experiment was to do cell fusion in a way that would allow the elimination of the embryonic stem cell nucleus to create an embryonic stem cell from the somatic cell," said Melton. (news-medical.net)
  • The nucleus of an adult somatic cell (such as a skin cell) is removed and transferred to an enucleated egg, which is then stimulated with electric current or chemicals to activate cell division. (who.int)
  • The realization that not all human embryonic stem cell lines are born equal is critical," Sun said. (sciencedaily.com)
  • If you're studying a disease found in a certain part of the brain, you should use a human embryonic stem cell line that produces the neurons from that region of the brain to get the most accurate results from your study. (sciencedaily.com)
  • Human embryonic stem cell (hESC)-derived MSCs are an alternative to adult MSCs that can circumvent issues regarding scalability and consistent quality due to their derivation from a renewable starting material. (nature.com)
  • The presomitic paraxial mesoderm is located adjacent to the notochord and neural tube and constitutes a longitudinal column of cells on either side of the notochord . (lifemapsc.com)
  • In collaboration with mathematicians, we focus on how many stem cells and stem cell types are required to setting up a functional organ during embryogenesis and in an already developed organism. (uni-heidelberg.de)
  • Notch1 and Notch 2, but not Notch4, were visualized in the nucleus of EB cells, and all these receptors were also observed as patent cytoplasmic foci. (karger.com)
  • At a terminal differentiation stage, cells expressing an osteoblast-like phenotype appeared either by transdifferentiation from hypertrophic chondrocytes or directly from osteoblast precursor cells. (uni-luebeck.de)
  • Huntington's disease, for example, is a forebrain disease, so the neurons should be differentiated from a cell line that is biased to produce neurons from the forebrain. (sciencedaily.com)
  • Sun said there are ways to prod an embryonic stem cell line biased to become neurons found in the rear brain to become neurons found in the forebrain. (sciencedaily.com)
  • Cyclin-dependent kinases such as CDK2 that promote cell cycle progression are overactive, in part due to downregulation of their inhibitors. (wikipedia.org)
  • Generally, cells have to closely coordinate growth and cell cycle progression during proliferation to prevent premature division. (uni-muenchen.de)
  • We are tackling functional heterogeneities on somatic stem cells by combining metabolic reporters in vivo with lineage progression. (uni-heidelberg.de)
  • By using a quantitative 4D analysis on the stem cells we aim at linking the metabolic state of a stem cell to its future clonal progression in its intact niche. (uni-heidelberg.de)
  • Stem cells have two unique characteristics: (1) an almost unlimited capacity for self-renewal (they can theoretically divide without limit to replenish other cells for as long as the person is alive) and (2) they retain the potential to produce differentiated and specialized cell types. (erlc.com)
  • Embryonic stem cells (ESCs) are stem cells that have been taken from the inner cell mass of a blastocyst, an embryo of about 150 cells that has not yet implanted into a woman's uterus. (erlc.com)
  • If an inner cell mass is taken from a mouse blastocyst and given the right nutrients, the pluripotent cells can grow in the laboratory. (eurostemcell.org)
  • Mouse ES cells can be put back into a mouse blastocyst and this blastocyst can then be returned to the uterus of a female mouse to develop into a foetus. (eurostemcell.org)
  • Approximately five days after fertilization the totipotent cells have differentiated and started to form a hollow sphere of cells called a blastocyst. (biomedcentral.com)
  • In the mouse, a transporting epithelium is established around the 8-16-cell stage through a process known as compaction where cell definition is lost and the outer cells of the embryo form tight junctions, giving rise to the blastocyst. (conditionmed.org)
  • Adult stem cells don't present any ethical problems. (healthline.com)
  • The National Marrow Donor Program (NMDP), founded in 1986, and the World Marrow Donor Association (WMDA), founded in 1988, were established to (1) locate and secure appropriate unrelated-donor HSCT sources for patients by promoting volunteer donation of bone marrow and peripheral blood stem cells in the community and (2) promote ethical practices of sharing stem cell sources by need, rather than by geographic location of the donor. (medscape.com)
  • Most cells are a particular type (such as the ceruminous gland cell) and have a specific function (in the case of the ceruminous gland cell, producing earwax). (erlc.com)
  • They have the ability to become any cell type in the body. (yourgenome.org)
  • they can make every type of cell in the body. (eurostemcell.org)
  • He hoped the hearing would inform the public that embryonic cells are not the only type showing promise. (pacatholic.org)
  • These cells can give rise to virtually any other type of cell in the body. (healthline.com)
  • For example, hematopoietic stem cells are a type of adult stem cell found in bone marrow. (healthline.com)
  • The cells giving rise to the foetus, are called pluripotent embryonic stem cells, since they can form every cell type in the body. (biomedcentral.com)
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  • Due to widespread applications of human embryonic stem (hES) cells, it is essential to establish effective protocols for cryopreservation and subsequent culture of hES cells to improve cell recovery. (ox.ac.uk)
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