The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
Neoplasms composed of primordial GERM CELLS of embryonic GONADS or of elements of the germ layers of the EMBRYO, MAMMALIAN. The concept does not refer to neoplasms located in the gonads or present in an embryo or FETUS.
The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
Tumors or cancer of the TESTIS. Germ cell tumors (GERMINOMA) of the testis constitute 95% of all testicular neoplasms.
A malignant neoplasm of the germinal tissue of the GONADS; MEDIASTINUM; or pineal region. Germinomas are uniform in appearance, consisting of large, round cells with vesicular nuclei and clear or finely granular eosinophilic-staining cytoplasm. (Stedman, 265th ed; from DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, pp1642-3)
Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.
Supporting cells projecting inward from the basement membrane of SEMINIFEROUS TUBULES. They surround and nourish the developing male germ cells and secrete ANDROGEN-BINDING PROTEIN and hormones such as ANTI-MULLERIAN HORMONE. The tight junctions of Sertoli cells with the SPERMATOGONIA and SPERMATOCYTES provide a BLOOD-TESTIS BARRIER.
The convoluted tubules in the TESTIS where sperm are produced (SPERMATOGENESIS) and conveyed to the RETE TESTIS. Spermatogenic tubules are composed of developing germ cells and the supporting SERTOLI CELLS.
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.
Male germ cells derived from SPERMATOGONIA. The euploid primary spermatocytes undergo MEIOSIS and give rise to the haploid secondary spermatocytes which in turn give rise to SPERMATIDS.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
The gamete-producing glands, OVARY or TESTIS.
A radiosensitive, malignant neoplasm of the testis, thought to be derived from primordial germ cells of the sexually undifferentiated embryonic gonad. There are three variants: classical (typical), the most common type; anaplastic; and spermatocytic. The classical seminoma is composed of fairly well differentiated sheets or cords of uniform polygonal or round cells (seminoma cells), each cell having abundant clear cytoplasm, distinct cell membranes, a centrally placed round nucleus, and one or more nucleoli. In the female, a grossly and histologically identical neoplasm, known as dysgerminoma, occurs. (Dorland, 27th ed)
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
Lectins purified from the germinating seeds of common wheat (Triticum vulgare); these bind to certain carbohydrate moieties on cell surface glycoproteins and are used to identify certain cell populations and inhibit or promote some immunological or physiological activities. There are at least two isoforms of this lectin.
The epithelium lining the seminiferous tubules composed of primary male germ cells (SPERMATOGONIA) and supporting SERTOLI CELLS. As SPERMATOGENESIS proceeds, the developing germ cells migrate toward the lumen. The adluminal compartment, the inner two thirds of the tubules, contains SPERMATOCYTES and the more advanced germ cells.
A malignant ovarian neoplasm, thought to be derived from primordial germ cells of the sexually undifferentiated embryonic gonad. It is the counterpart of the classical seminoma of the testis, to which it is both grossly and histologically identical. Dysgerminomas comprise 16% of all germ cell tumors but are rare before the age of 10, although nearly 50% occur before the age of 20. They are generally considered of low-grade malignancy but may spread if the tumor extends through its capsule and involves lymph nodes or blood vessels. (Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1646)
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
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.
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.
The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).
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)
An unusual and aggressive tumor of germ-cell origin that reproduces the extraembryonic structures of the early embryo. It is the most common malignant germ cell tumor found in children. It is characterized by a labyrinthine glandular pattern of flat epithelial cells and rounded papillary processes with a central capillary (Schiller-Duval body). The tumor is rarely bilateral. Before the use of combination chemotherapy, the tumor was almost invariably fatal. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1189)
Euploid female germ cells of an early stage of OOGENESIS, derived from primordial germ cells during ovarian differentiation. Oogonia undergo MEIOSIS and give rise to haploid OOCYTES
The process in developing sex- or gender-specific tissue, organ, or function after SEX DETERMINATION PROCESSES have set the sex of the GONADS. Major areas of sex differentiation occur in the reproductive tract (GENITALIA) and the brain.
An orphan nuclear receptor expressed mainly in the GERM CELLS of GONADS. It functions as a transcription factor that binds to a direct repeat of the sequence AGGTCA and may play a role in the regulation of EMBRYOGENESIS and germ cell differentiation.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
The collective tissues from which an entire tooth is formed, including the DENTAL SAC; ENAMEL ORGAN; and DENTAL PAPILLA. (From Jablonski, Dictionary of Dentistry, 1992)
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
A developmental defect in which a TESTIS or both TESTES failed to descend from high in the ABDOMEN to the bottom of the SCROTUM. Testicular descent is essential to normal SPERMATOGENESIS which requires temperature lower than the BODY TEMPERATURE. Cryptorchidism can be subclassified by the location of the maldescended testis.
Tumors or cancer of the MEDIASTINUM.
An octamer transcription factor that is expressed primarily in totipotent embryonic STEM CELLS and GERM CELLS and is down-regulated during CELL DIFFERENTIATION.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
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)
Retroperitoneal neoplasms are a diverse group of tumors that originate in the retroperitoneal space, which is the area behind the peritoneum and includes the kidneys, adrenal glands, pancreas, and major blood vessels.
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.
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.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
A count of SPERM in the ejaculum, expressed as number per milliliter.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
The mechanisms by which the SEX of an individual's GONADS are fixed.
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.
A specialized barrier, in the TESTIS, between the interstitial BLOOD compartment and the adluminal compartment of the SEMINIFEROUS TUBULES. The barrier is formed by layers of cells from the VASCULAR ENDOTHELIUM of the capillary BLOOD VESSELS, to the SEMINIFEROUS EPITHELIUM of the seminiferous tubules. TIGHT JUNCTIONS form between adjacent SERTOLI CELLS, as well as between the ENDOTHELIAL CELLS.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The stage in the first meiotic prophase, following ZYGOTENE STAGE, when CROSSING OVER between homologous CHROMOSOMES begins.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.
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.
A malignant metastatic form of trophoblastic tumors. Unlike the HYDATIDIFORM MOLE, choriocarcinoma contains no CHORIONIC VILLI but rather sheets of undifferentiated cytotrophoblasts and syncytiotrophoblasts (TROPHOBLASTS). It is characterized by the large amounts of CHORIONIC GONADOTROPIN produced. Tissue origins can be determined by DNA analyses: placental (fetal) origin or non-placental origin (CHORIOCARCINOMA, NON-GESTATIONAL).
The first alpha-globulins to appear in mammalian sera during FETAL DEVELOPMENT and the dominant serum proteins in early embryonic life.
A complex of related glycopeptide antibiotics from Streptomyces verticillus consisting of bleomycin A2 and B2. It inhibits DNA metabolism and is used as an antineoplastic, especially for solid tumors.
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
The capacity to conceive or to induce conception. It may refer to either the male or female.
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.
A large family of RNA helicases that share a common protein motif with the single letter amino acid sequence D-E-A-D (Asp-Glu-Ala-Asp). In addition to RNA helicase activity, members of the DEAD-box family participate in other aspects of RNA metabolism and regulation of RNA function.
Cells that can give rise to cells of the three different GERM LAYERS.
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.
Morphological and physiological development of EMBRYOS.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
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.
In gonochoristic organisms, congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Effects from exposure to abnormal levels of GONADAL HORMONES in the maternal environment, or disruption of the function of those hormones by ENDOCRINE DISRUPTORS are included.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.
Inflammation of a TESTIS. It has many features of EPIDIDYMITIS, such as swollen SCROTUM; PAIN; PYURIA; and FEVER. It is usually related to infections in the URINARY TRACT, which likely spread to the EPIDIDYMIS and then the TESTIS through either the VAS DEFERENS or the lymphatics of the SPERMATIC CORD.
A rare tumor of the female genital tract, most often the ovary, formerly considered to be derived from mesonephric rests. Two varieties are recognized: (1) clear cell carcinoma, so called because of its histologic resemblance to renal cell carcinoma, and now considered to be of muellerian duct derivation and (2) an embryonal tumor (called also ENDODERMAL SINUS TUMOR and yolk sac tumor), occurring chiefly in children. The latter variety may also arise in the testis. (Dorland, 27th ed)
The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.
Messenger RNA that is stored in a masked state for translation at a later time. Distinguish from RNA, UNTRANSLATED which refers to non-messenger RNA, i.e. RNA that does not code for protein.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
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)
An inorganic and water-soluble platinum complex. After undergoing hydrolysis, it reacts with DNA to produce both intra and interstrand crosslinks. These crosslinks appear to impair replication and transcription of DNA. The cytotoxicity of cisplatin correlates with cellular arrest in the G2 phase of the cell cycle.
The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.
An individual that contains cell populations derived from different zygotes.
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.
Pathological processes of the TESTIS.
An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.
Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.
A class of free-living freshwater flatworms of North America.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
The only genus in the family Oryziinae, order BELONIFORMES. Oryzias are egg-layers; other fish of the same order are livebearers. Oryzias are used extensively in testing carcinogens.
The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.
The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
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 prophase of the first division of MEIOSIS (in which homologous CHROMOSOME SEGREGATION occurs). It is divided into five stages: leptonema, zygonema, PACHYNEMA, diplonema, and diakinesis.
An area occupying the most posterior aspect of the ABDOMINAL CAVITY. It is bounded laterally by the borders of the quadratus lumborum muscles and extends from the DIAPHRAGM to the brim of the true PELVIS, where it continues as the pelvic extraperitoneal space.
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.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
A semisynthetic derivative of PODOPHYLLOTOXIN that exhibits antitumor activity. Etoposide inhibits DNA synthesis by forming a complex with topoisomerase II and DNA. This complex induces breaks in double stranded DNA and prevents repair by topoisomerase II binding. Accumulated breaks in DNA prevent entry into the mitotic phase of cell division, and lead to cell death. Etoposide acts primarily in the G2 and S phases of the cell cycle.
The external and internal organs related to reproduction.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.
The measurement of an organ in volume, mass, or heaviness.
Morphological and physiological development of EMBRYOS or FETUSES.
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.
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.
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.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
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.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
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.
The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained.
Inbred ICR mice are a strain of albino laboratory mice that have been selectively bred for consistent genetic makeup and high reproductive performance, making them widely used in biomedical research for studies involving reproduction, toxicology, pharmacology, and carcinogenesis.
A form of male HYPOGONADISM, characterized by the presence of an extra X CHROMOSOME, small TESTES, seminiferous tubule dysgenesis, elevated levels of GONADOTROPINS, low serum TESTOSTERONE, underdeveloped secondary sex characteristics, and male infertility (INFERTILITY, MALE). Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several karyotype variants include 48,XXYY; 48,XXXY; 49,XXXXY, and mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.).
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
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 type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
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)
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.
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 status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
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.
Chemical substances or agents with contraceptive activity in males. Use for male contraceptive agents in general or for which there is no specific heading.
A number of syndromes with defective gonadal developments such as streak GONADS and dysgenetic testes or ovaries. The spectrum of gonadal and sexual abnormalities is reflected in their varied sex chromosome (SEX CHROMOSOMES) constitution as shown by the karyotypes of 45,X monosomy (TURNER SYNDROME); 46,XX (GONADAL DYSGENESIS, 46XX); 46,XY (GONADAL DYSGENESIS, 46,XY); and sex chromosome MOSAICISM; (GONADAL DYSGENESIS, MIXED). Their phenotypes range from female, through ambiguous, to male. This concept includes gonadal agenesis.
Elements of limited time intervals, contributing to particular results or situations.
A complex neoplasm composed of a mixture of gonadal elements, such as large primordial GERM CELLS, immature SERTOLI CELLS or GRANULOSA CELLS of the sex cord, and gonadal stromal cells. Gonadoblastomas are most often associated with gonadal dysgenesis, 46, XY.
Positional isomer of CYCLOPHOSPHAMIDE which is active as an alkylating agent and an immunosuppressive agent.
A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.
A fibroblast growth factor that was originally identified as a mitogen for GLIAL CELLS. It is expressed primarily in NEURONS.
Agents, either mechanical or chemical, which destroy spermatozoa in the male genitalia and block spermatogenesis.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
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.
A condition of suboptimal concentration of SPERMATOZOA in the ejaculated SEMEN to ensure successful FERTILIZATION of an OVUM. In humans, oligospermia is defined as a sperm count below 20 million per milliliter semen.
The surgical removal of one or both testicles.
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.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
A type of male infertility in which no germ cells are visible in any of the biopsied SEMINIFEROUS TUBULES (type I) or in which germ cells are present in a minority of tubules (type II). Clinical features include AZOOSPERMIA, normal VIRILIZATION, and normal chromosomal complement.
Transference of cells within an individual, between individuals of the same species, or between individuals of different species.
All of the processes involved in increasing CELL NUMBER including CELL 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 degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Animals and plants which have, as their normal mode of reproduction, both male and female sex organs in the same individual.
The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.
Nonparasitic free-living flatworms of the class Turbellaria. The most common genera are Dugesia, formerly Planaria, which lives in water, and Bipalium, which lives on land. Geoplana occurs in South America and California.
The functional hereditary units of INSECTS.
Achievement of full sexual capacity in animals and in humans.
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.
Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.
An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
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).
Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
Refers to animals in the period of time just after birth.
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).
Mice bearing mutant genes which are phenotypically expressed in the animals.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
A therapeutic approach, involving chemotherapy, radiation therapy, or surgery, after initial regimens have failed to lead to improvement in a patient's condition. Salvage therapy is most often used for neoplastic diseases.
The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.
Gonadal neoplasm composed entirely of SERTOLI CELLS or may have a component of GRANULOSA CELLS. Some of the Sertoli cell tumors produce ESTROGEN or ANDROGENS, but seldom in sufficient quantity to cause clinical symptoms such as FEMINIZATION or masculinization (VIRILISM).
A condition of having no sperm present in the ejaculate (SEMEN).
A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).
The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
The sequence at the 3' end of messenger RNA that does not code for product. This region contains transcription and translation regulating sequences.
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
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.
The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
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.
Cyclic AMP response element modulator is a basic leucine zipper transcription factor that is regulated by CYCLIC AMP. It plays an important role in SPERMATID development in the mammalian TESTIS.
A family of RNA-binding proteins that has specificity for MICRORNAS and SMALL INTERFERING RNA molecules. The proteins take part in RNA processing events as core components of RNA-induced silencing complex.
A lesion with cytological characteristics associated with invasive carcinoma but the tumor cells are confined to the epithelium of origin, without invasion of the basement membrane.
An ester of phthalic acid. It appears as a light-colored, odorless liquid and is used as a plasticizer for many resins and elastomers.
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.
Methods for maintaining or growing CELLS in vitro.
Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.
Neoplasms composed of tissues of the OVARY or the TESTIS, not neoplasms located in the ovaries or testes. Gonadal tissues include GERM CELLS, cells from the sex cord, and gonadal stromal cells.
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.
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 that inhibit pituitary FOLLICLE STIMULATING HORMONE secretion. Inhibins are secreted by the Sertoli cells of the testes, the granulosa cells of the ovarian follicles, the placenta, and other tissues. Inhibins and ACTIVINS are modulators of FOLLICLE STIMULATING HORMONE secretions; both groups belong to the TGF-beta superfamily, as the TRANSFORMING GROWTH FACTOR BETA. Inhibins consist of a disulfide-linked heterodimer with a unique alpha linked to either a beta A or a beta B subunit to form inhibin A or inhibin B, respectively
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.
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.
Carrier proteins produced in the Sertoli cells of the testis, secreted into the seminiferous tubules, and transported via the efferent ducts to the epididymis. They participate in the transport of androgens. Androgen-binding protein has the same amino acid sequence as SEX HORMONE-BINDING GLOBULIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.
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 Caenorhabditis elegans sex determination gene mog-1 encodes a member of the DEAH-Box protein family. (1/2975)

In the Caenorhabditis elegans hermaphrodite germ line, the sex-determining gene fem-3 is repressed posttranscriptionally to arrest spermatogenesis and permit oogenesis. This repression requires a cis-acting regulatory element in the fem-3 3' untranslated region; the FBF protein, which binds to this element; and at least six mog genes. In this paper, we report the molecular characterization of mog-1 as well as additional phenotypic characterization of this gene. The mog-1 gene encodes a member of the DEAH-box family. Three mog-1 alleles possess premature stop codons and are likely to be null alleles, and one is a missense mutation and is likely to retain residual activity. mog-1 mRNA is expressed in both germ line and somatic tissues and appears to be ubiquitous. The MOG-1 DEAH-box protein is most closely related to proteins essential for splicing in the yeast Saccharomyces cerevisiae, but splicing appears to occur normally in a mog-1-null mutant. In addition to its involvement in the sperm-oocyte switch and control of fem-3, zygotic mog-1 is required for robust germ line proliferation and for normal growth during development. We suggest that mog-1 plays a broader role in RNA regulation than previously considered.  (+info)

Bmp4 is required for the generation of primordial germ cells in the mouse embryo. (2/2975)

In many organisms the allocation of primordial germ cells (PGCs) is determined by the inheritance of maternal factors deposited in the egg. However, in mammals, inductive cell interactions are required around gastrulation to establish the germ line. Here, we show that Bmp4 homozygous null embryos contain no PGCs. They also lack an allantois, an extraembryonic mesodermal tissue derived, like the PGCs, from precursors in the proximal epiblast. Heterozygotes have fewer PGCs than normal, due to a reduction in the size of the founding population and not to an effect on its subsequent expansion. Analysis of beta-galactosidase activity in Bmp4(lacZneo) embryos reveals that prior to gastrulation, Bmp4 is expressed in the extraembryonic ectoderm. Later, Bmp4 is expressed in the extraembryonic mesoderm, but not in PGCs. Chimera analysis indicates that it is the Bmp4 expression in the extraembryonic ectoderm that regulates the formation of allantois and primordial germ cell precursors, and the size of the founding population of PGCs. The initiation of the germ line in the mouse therefore depends on a secreted signal from the previously segregated, extraembryonic, trophectoderm lineage.  (+info)

Germ cell development in the XXY mouse: evidence that X chromosome reactivation is independent of sexual differentiation. (3/2975)

Prior to entry into meiosis, XX germ cells in the fetal ovary undergo X chromosome reactivation. The signal for reactivation is thought to emanate from the genital ridge, but it is unclear whether it is specific to the developing ovary. To determine whether the signals are present in the developing testis as well as the ovary, we examined the expression of X-linked genes in germ cells from XXY male mice. To facilitate this analysis, we generated XXY and XX fetuses carrying X chromosomes that were differentially marked and subject to nonrandom inactivation. This pattern of nonrandom inactivation was maintained in somatic cells but, in XX as well as XXY fetuses, both parental alleles were expressed in germ cell-enriched cell populations. Because testis differentiation is temporally and morphologically normal in the XXY testis and because all germ cells embark upon a male pathway of development, these results provide compelling evidence that X chromosome reactivation in fetal germ cells is independent of the somatic events of sexual differentiation. Proper X chromosome dosage is essential for the normal fertility of male mammals, and abnormalities in germ cell development are apparent in the XXY testis within several days of X reactivation. Studies of exceptional germ cells that survive in the postnatal XXY testis demonstrated that surviving germ cells are exclusively XY and result from rare nondisjunctional events that give rise to clones of XY cells.  (+info)

Ialpha exon-replacement mice synthesize a spliced HPRT-C(alpha) transcript which may explain their ability to switch to IgA. Inhibition of switching to IgG in these mice. (4/2975)

Antibody class switching is regulated by transcription of unrearranged C(H) genes to produce germline (GL) transcripts which direct the choice of isotype and are required for switching. However, their role is unknown. GL transcripts are initiated at the I exons located upstream of each switch region. Although deletion of the I exon by gene targeting prevents switch recombination to that CH gene, the Ialpha exon can be replaced by an entirely different DNA segment, a minigene driven by the phosphoglycerate kinase (PGK) promoter and encoding hypoxanthine phosphoribosyl transferase (HPRT), oriented in the sense direction, without reducing antibody class switching to IgA. To understand why HPRT substitution of the Ialpha exon does not disrupt switch recombination, we have analyzed the structure of the transcript from the targeted allele in these mice. We identify a spliced transcript in which the HPRT exons are spliced to the C(alpha) gene segments, resulting in a structure similar to normal GL transcripts. The abundance of this transcript is similar to that of the normal alpha GL RNA. We also demonstrate that switching to the four IgG subclasses in B cells from these mice is reduced in comparison to wild-type mice. We discuss the possibility that the strong PGK promoter inserted at the Ig alpha locus may interfere with interaction of the promoters for gamma GL transcripts with the 3' IgH enhancer.  (+info)

Production of donor-derived offspring by transfer of primordial germ cells in Japanese quail. (5/2975)

We transfused concentrated primordial germ cells (PGCs) of the black strain (D: homozygous for the autosomal incomplete dominant gene, D) of quail into the embryos of the wild-type plumage strain (WP: d+/d+) of quail. The recipient quail were raised until sexual maturity and a progeny test of the putative germline chimeras was performed to examine the donor gamete-derived offspring (D/d+). Thirty-one percent (36/115) of the transfused quail hatched and 21 (13 females and 8 males) of them reached maturity. Five females and 2 males were germline chimeras producing donor gamete-derived offspring. Transmission rates of the donor derived gametes in the chimeric females and males were 1.8-8.3% and 2.6-63.0%, respectively. Germline chimeric and the other putative chimeric males were also test-mated with females from the sex-linked imperfect albino strain (AL: d+/d+, al/W, where al indicates the sex-linked imperfect albino gene on the Z chromosome, and W indicates the W chromosome) for autosexing of W-bearing spermatozoa: No albino offspring were born.  (+info)

Histone ubiquitination and chromatin remodeling in mouse spermatogenesis. (6/2975)

Male infertility in HR6B knockout mice is associated with impairment of spermatogenesis. The HR6B gene is a mammalian, autosomal homolog of the Saccharomyces cerevisiae gene Rad6 encoding a ubiquitin-conjugating enzyme. In addition, X-chromosomal HR6A has been identified, in human and mouse. RAD6 in yeast is required for a variety of cellular functions, including sporulation, DNA repair, and mutagenesis. Since RAD6 and its mammalian homologs can ubiquitinate histones in vitro, we have investigated the pattern of histone ubiquitination in mouse testis. By immunoblot and immunohistochemical analysis of wild-type mouse testis, a high amount of ubiquitinated H2A (uH2A) was detected in pachytene spermatocytes. This signal became undetectable in round spermatids, but then increased again during a relatively short developmental period, in elongating spermatids. No other ubiquitinated histones were observed. In the HR6B knockout mice, we failed to detect an overt defect in the overall pattern of histone ubiquitination. For somatic cell types, it has been shown that histone ubiquitination is associated with destabilization of nucleosomes, in relation to active gene transcription. Unexpectedly, the most intense uH2A signal in pachytene spermatocytes was detected in the sex body, an inactive nuclear structure that contains the heterochromatic X and Y chromosomes. The postmeiotic uH2A immunoexpression in elongating spermatids indicates that nucleosome destabilization induced by histone ubiquitination may play a facilitating role during histone-to-protamine replacement.  (+info)

Activin and TGFbeta limit murine primordial germ cell proliferation. (7/2975)

Mammalian primordial germ cells (PGCs) proliferate as they migrate from their initial location in the extraembryonic mesoderm to the genital ridge, the gonadal anlage. Once in the genital ridge, PGCs cease dividing and differentiate according to their gender. To identify ligands that might limit PGC proliferation, we analyzed growth factor receptors encoded in RNA obtained from purified germ cells shortly after their arrival in the genital ridge. Receptors for two members of the TGFbeta superfamily were found, TGFbeta1 and activin. As the signal-transducing domains of both receptor systems are highly conserved, the effects of both TGFbeta1 and activin on PGCs would be expected to be similar. We found that both ligands limited the accumulation of germ cells in primary PGC cultures. BrdU incorporation assays demonstrated that either ligand inhibits PGC proliferation. These results suggest that these signal transduction pathways are important elements of the mechanism that determines germ cell endowment.  (+info)

A novel quantitative morphometry of germ cells for the histopathological evaluation of rat testicular toxicity. (8/2975)

A view that 14 stages of rat spermatogenic cycle could be arranged into 4 groups, viz., conventional stages I-VI, VII-VIII, IX-XI and XII-XIV, according to the features of elongated spermatids was previously presented. A novel morphometry of seminiferous epithelia based on these 4 groups was also proposed. In the present study, utility of the proposed morphometry in the histopathological evaluations of testicular toxicities was monitored in comparison with the conventional one. After administrating adriamycin, ethylene glycol monomethyl ether or 1,3-dinitrobenzene to rats, the viability of their germ cells was estimated by the proposed morphometry and the conventional one employed stages II-III, V, VII, X and XII. In every case, the evaluating results of the proposed morphometry were similar to those of the conventional one. Thus, it was verified that the proposed morphometry was identical with the conventional one in respect of reliable detection of the testicular toxicities. In addition, in situ terminal dUTP nick end labeling indicated that death of spermatogonia, pachytene spermatocytes or round spermatids induced by the above 3 toxic compounds was exclusively apoptotic death. In conclusion, the proposed morphometry would be useful as a practical tool in the evaluation of testicular toxicities.  (+info)

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.

Neoplasms, germ cell and embryonal are types of tumors that originate from the abnormal growth of cells. Here's a brief medical definition for each:

1. Neoplasms: Neoplasms refer to abnormal tissue growths or masses, which can be benign (non-cancerous) or malignant (cancerous). They result from uncontrolled cell division and may invade surrounding tissues or spread to other parts of the body through a process called metastasis.
2. Germ Cell Tumors: These are rare tumors that develop from the germ cells, which give rise to sperm and eggs in the reproductive organs (ovaries and testes). They can be benign or malignant and may occur in both children and adults. Germ cell tumors can also arise outside of the reproductive organs, a condition known as extragonadal germ cell tumors.
3. Embryonal Tumors: These are a type of malignant neoplasm that primarily affects infants and young children. They develop from embryonic cells, which are immature cells present during fetal development. Embryonal tumors can occur in various organs, including the brain (medulloblastomas), nervous system (primitive neuroectodermal tumors or PNETs), and other areas like the kidneys and liver.

It is essential to note that these conditions require professional medical evaluation and treatment by healthcare professionals with expertise in oncology and related fields.

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.

Spermatogenesis is the process by which sperm cells, or spermatozoa, are produced in male organisms. It occurs in the seminiferous tubules of the testes and involves several stages:

1. Spermatocytogenesis: This is the initial stage where diploid spermatogonial stem cells divide mitotically to produce more spermatogonia, some of which will differentiate into primary spermatocytes.
2. Meiosis: The primary spermatocytes undergo meiotic division to form haploid secondary spermatocytes, which then divide again to form haploid spermatids. This process results in the reduction of chromosome number from 46 (diploid) to 23 (haploid).
3. Spermiogenesis: The spermatids differentiate into spermatozoa, undergoing morphological changes such as the formation of a head and tail. During this stage, most of the cytoplasm is discarded, resulting in highly compacted and streamlined sperm cells.
4. Spermation: The final stage where mature sperm are released from the seminiferous tubules into the epididymis for further maturation and storage.

The entire process takes approximately 72-74 days in humans, with continuous production throughout adulthood.

Testicular neoplasms are abnormal growths or tumors in the testicle that can be benign (non-cancerous) or malignant (cancerous). They are a type of genitourinary cancer, which affects the reproductive and urinary systems. Testicular neoplasms can occur in men of any age but are most commonly found in young adults between the ages of 15 and 40.

Testicular neoplasms can be classified into two main categories: germ cell tumors and non-germ cell tumors. Germ cell tumors, which arise from the cells that give rise to sperm, are further divided into seminomas and non-seminomas. Seminomas are typically slow-growing and have a good prognosis, while non-seminomas tend to grow more quickly and can spread to other parts of the body.

Non-germ cell tumors are less common than germ cell tumors and include Leydig cell tumors, Sertoli cell tumors, and lymphomas. These tumors can have a variety of clinical behaviors, ranging from benign to malignant.

Testicular neoplasms often present as a painless mass or swelling in the testicle. Other symptoms may include a feeling of heaviness or discomfort in the scrotum, a dull ache in the lower abdomen or groin, and breast enlargement (gynecomastia).

Diagnosis typically involves a physical examination, imaging studies such as ultrasound or CT scan, and blood tests to detect tumor markers. Treatment options depend on the type and stage of the neoplasm but may include surgery, radiation therapy, chemotherapy, or a combination of these modalities. Regular self-examinations of the testicles are recommended for early detection and improved outcomes.

A germinoma is a type of tumor that develops in the brain or the spine, primarily in the pituitary gland or pineal gland. It is a rare form of primary central nervous system (CNS) cancer and is classified as a type of germ cell tumor. These tumors arise from cells that normally develop into sperm or eggs, which can migrate to unusual locations during embryonic development.

Germinomas are highly sensitive to radiation therapy and chemotherapy, making them generally treatable and curable with appropriate medical intervention. Symptoms of a germinoma may include headaches, nausea, vomiting, visual disturbances, hormonal imbalances, and neurological deficits, depending on the location and size of the tumor. Diagnosis typically involves imaging studies like MRI or CT scans, followed by a biopsy to confirm the presence of malignant cells.

Spermatozoa are the male reproductive cells, or gametes, that are produced in the testes. They are microscopic, flagellated (tail-equipped) cells that are highly specialized for fertilization. A spermatozoon consists of a head, neck, and tail. The head contains the genetic material within the nucleus, covered by a cap-like structure called the acrosome which contains enzymes to help the sperm penetrate the female's egg (ovum). The long, thin tail propels the sperm forward through fluid, such as semen, enabling its journey towards the egg for fertilization.

Sertoli cells, also known as sustentacular cells or nurse cells, are specialized cells in the seminiferous tubules of the testis in mammals. They play a crucial role in supporting and nurturing the development of sperm cells (spermatogenesis). Sertoli cells create a microenvironment within the seminiferous tubules that facilitates the differentiation, maturation, and survival of germ cells.

These cells have several essential functions:

1. Blood-testis barrier formation: Sertoli cells form tight junctions with each other, creating a physical barrier called the blood-testis barrier, which separates the seminiferous tubules into basal and adluminal compartments. This barrier protects the developing sperm cells from the immune system and provides an isolated environment for their maturation.
2. Nutrition and support: Sertoli cells provide essential nutrients and growth factors to germ cells, ensuring their proper development and survival. They also engulf and digest residual bodies, which are byproducts of spermatid differentiation.
3. Phagocytosis: Sertoli cells have phagocytic properties, allowing them to remove debris and dead cells within the seminiferous tubules.
4. Hormone metabolism: Sertoli cells express receptors for various hormones, such as follicle-stimulating hormone (FSH), testosterone, and estradiol. They play a role in regulating hormonal signaling within the testis by metabolizing these hormones or producing inhibins, which modulate FSH secretion from the pituitary gland.
5. Regulation of spermatogenesis: Sertoli cells produce and secrete various proteins and growth factors that influence germ cell development and proliferation. They also control the release of mature sperm cells into the epididymis through a process called spermiation.

Seminiferous tubules are the long, convoluted tubes within the testicles that are responsible for producing sperm in males. They are lined with specialized epithelial cells called Sertoli cells, which provide structural support and nourishment to developing sperm cells. The seminiferous tubules also contain germ cells, which divide and differentiate into spermatozoa (sperm) through the process of spermatogenesis.

The seminiferous tubules are surrounded by a thin layer of smooth muscle called the tunica albuginea, which helps to maintain the structure and integrity of the testicle. The tubules are connected to the rete testis, a network of channels that transport sperm to the epididymis for further maturation and storage before ejaculation.

Damage or dysfunction of the seminiferous tubules can lead to male infertility, as well as other reproductive health issues.

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.

Spermatocytes are a type of cell that is involved in the process of spermatogenesis, which is the formation of sperm in the testes. Specifically, spermatocytes are the cells that undergo meiosis, a special type of cell division that results in the production of four haploid daughter cells, each containing half the number of chromosomes as the parent cell.

There are two types of spermatocytes: primary and secondary. Primary spermatocytes are diploid cells that contain 46 chromosomes (23 pairs). During meiosis I, these cells undergo a process called crossing over, in which genetic material is exchanged between homologous chromosomes. After crossing over, the primary spermatocytes divide into two secondary spermatocytes, each containing 23 chromosomes (but still with 23 pairs).

Secondary spermatocytes then undergo meiosis II, which results in the formation of four haploid spermatids. Each spermatid contains 23 single chromosomes and will eventually develop into a mature sperm cell through a process called spermiogenesis.

It's worth noting that spermatocytes are only found in males, as they are specific to the male reproductive system.

Spermatids are immature sperm cells that are produced during the process of spermatogenesis in the male testes. They are the product of the final stage of meiosis, where a diploid spermatocyte divides into four haploid spermatids. Each spermatid then undergoes a series of changes, including the development of a tail for motility and the condensation of its nucleus to form a head containing the genetic material. Once this process is complete, the spermatids are considered mature spermatozoa and are capable of fertilizing an egg.

Gonads are the reproductive organs that produce gametes (sex cells) and sex hormones. In males, the gonads are the testes, which produce sperm and testosterone. In females, the gonads are the ovaries, which produce eggs and estrogen and progesterone. The development, function, and regulation of the gonads are crucial for reproductive health and fertility.

Seminoma is a type of germ cell tumor that develops in the testicle. It is a malignant tumor, meaning it can spread to other parts of the body if left untreated. Seminomas are typically slow-growing and tend to remain localized to the testicle for a longer period compared to other types of testicular cancer. They usually occur in men between the ages of 25 and 45 but can develop at any age.

Seminomas can be classified into two main subtypes: classical seminoma and spermatocytic seminoma. Classical seminoma is more common and typically responds well to treatment, while spermatocytic seminoma is rarer and tends to have a better prognosis with a lower risk of spreading.

Seminomas are usually treated with surgery to remove the affected testicle (orchiectomy), followed by radiation therapy or chemotherapy to kill any remaining cancer cells. The prognosis for seminoma is generally good, especially when caught and treated early. Regular self-examinations of the testicles can help detect any lumps or abnormalities that may indicate the presence of a seminoma or other type of testicular cancer.

Meiosis is a type of cell division that results in the formation of four daughter cells, each with half the number of chromosomes as the parent cell. It is a key process in sexual reproduction, where it generates gametes or sex cells (sperm and eggs).

The process of meiosis involves one round of DNA replication followed by two successive nuclear divisions, meiosis I and meiosis II. In meiosis I, homologous chromosomes pair, form chiasma and exchange genetic material through crossing over, then separate from each other. In meiosis II, sister chromatids separate, leading to the formation of four haploid cells. This process ensures genetic diversity in offspring by shuffling and recombining genetic information during the formation of gametes.

Wheat germ agglutinins (WGA) are proteins found in wheat germ that have the ability to bind to specific carbohydrate structures, such as N-acetylglucosamine and sialic acid, which are present on the surface of many cells in the human body. WGA is a type of lectin, a group of proteins that can agglutinate, or clump together, red blood cells and bind to specific sugars on cell membranes.

WGA has been studied for its potential effects on various biological processes, including inflammation, immune response, and gut barrier function. Some research suggests that WGA may interact with the gut epithelium and affect intestinal permeability, potentially contributing to the development of gastrointestinal symptoms in some individuals. However, more research is needed to fully understand the clinical significance of these findings.

It's worth noting that while WGA has been studied for its potential biological effects, it is not currently recognized as a major allergen or toxic component of wheat. However, some people may still choose to avoid foods containing WGA due to personal dietary preferences or sensitivities.

The seminiferous epithelium is a specialized type of epithelial tissue that lines the seminiferous tubules within the testes. It is composed of various cell types, including germ cells in different stages of development (spermatogonia, primary and secondary spermatocytes, spermatids) and supportive cells called Sertoli cells.

The primary function of the seminiferous epithelium is to support sperm production (spermatogenesis). The Sertoli cells provide structural support and nourishment to the developing germ cells, helping them to differentiate into mature spermatozoa (sperm). This process involves a series of complex cellular events, including mitosis, meiosis, and spermiogenesis.

In addition to its role in sperm production, the seminiferous epithelium also plays a crucial part in maintaining the blood-testis barrier, which separates the testicular environment from the systemic circulation. This barrier helps protect developing germ cells from potential immune attacks and maintains an optimal microenvironment for spermatogenesis.

Dysgerminoma is a type of germ cell tumor that develops in the ovaries. It is a malignant (cancerous) tumor that primarily affects girls and women of reproductive age, although it can occur at any age. Dysgerminomas are composed of large, round, or polygonal cells with clear cytoplasm and distinct cell borders, arranged in nests or sheets. They may also contain lymphoid aggregates and may produce hormones such as estrogen or testosterone.

Dysgerminomas are usually unilateral (affecting one ovary), but they can be bilateral (affecting both ovaries) in about 10-15% of cases. They tend to grow and spread rapidly, so early detection and treatment are crucial for a favorable prognosis.

The standard treatment for dysgerminoma is surgical removal of the affected ovary or ovaries, followed by chemotherapy with agents such as bleomycin, etoposide, and cisplatin (BEP). With appropriate treatment, the five-year survival rate for patients with dysgerminoma is high, ranging from 80% to 95%.

Oogenesis is the biological process of formation and maturation of female gametes, or ova or egg cells, in the ovary. It begins during fetal development and continues throughout a woman's reproductive years. The process involves the division and differentiation of a germ cell (oogonium) into an immature ovum (oocyte), which then undergoes meiotic division to form a mature ovum capable of being fertilized by sperm.

The main steps in oogenesis include:

1. Multiplication phase: The oogonia divide mitotically to increase their number.
2. Growth phase: One of the oogonia becomes primary oocyte and starts to grow, accumulating nutrients and organelles required for future development.
3. First meiotic division: The primary oocyte undergoes an incomplete first meiotic division, resulting in two haploid cells - a secondary oocyte and a smaller cell called the first polar body. This division is arrested in prophase I until puberty.
4. Second meiotic division: At ovulation or just before fertilization, the secondary oocyte completes the second meiotic division, producing another small cell, the second polar body, and a mature ovum (egg) with 23 chromosomes.
5. Fertilization: The mature ovum can be fertilized by a sperm, restoring the normal diploid number of chromosomes in the resulting zygote.

Oogenesis is a complex and highly regulated process that involves various hormonal signals and cellular interactions to ensure proper development and maturation of female gametes for successful reproduction.

An ovary is a part of the female reproductive system in which ova or eggs are produced through the process of oogenesis. They are a pair of solid, almond-shaped structures located one on each side of the uterus within the pelvic cavity. Each ovary measures about 3 to 5 centimeters in length and weighs around 14 grams.

The ovaries have two main functions: endocrine (hormonal) function and reproductive function. They produce and release eggs (ovulation) responsible for potential fertilization and development of an embryo/fetus during pregnancy. Additionally, they are essential in the production of female sex hormones, primarily estrogen and progesterone, which regulate menstrual cycles, sexual development, and reproduction.

During each menstrual cycle, a mature egg is released from one of the ovaries into the fallopian tube, where it may be fertilized by sperm. If not fertilized, the egg, along with the uterine lining, will be shed, leading to menstruation.

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.

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.

Gametogenesis is the biological process by which haploid gametes, or sex cells (sperm and egg cells), are produced through the meiotic division of diploid germ cells. In females, this process is called oogenesis, where an oogonium (diploid germ cell) undergoes mitosis to form an oocyte (immature egg cell). The oocyte then undergoes meiosis I to form a secondary oocyte and a polar body. After fertilization by a sperm cell, the secondary oocyte completes meiosis II to form a mature ovum or egg cell.

In males, this process is called spermatogenesis, where a spermatogonium (diploid germ cell) undergoes mitosis to form primary spermatocytes. Each primary spermatocyte then undergoes meiosis I to form two secondary spermatocytes, which subsequently undergo meiosis II to form four haploid spermatids. The spermatids then differentiate into spermatozoa or sperm cells through a process called spermiogenesis.

Gametogenesis is essential for sexual reproduction and genetic diversity, as it involves the random segregation of chromosomes during meiosis and the recombination of genetic material between homologous chromosomes.

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.

An Endodermal Sinus Tumor (EST) is a type of germ cell tumor, which is a rare cancer that occurs most frequently in the ovaries or testicles but can also occur in other parts of the body. EST is also known as a yolk sac tumor because it resembles the yolk sac of an embryo.

ESTs are highly aggressive and fast-growing tumors that typically affect children and young adults, with a peak incidence in the first decade of life. These tumors can produce various proteins and substances, such as alpha-fetoprotein (AFP), which can be used as markers for diagnosis and monitoring treatment response.

The symptoms of EST depend on the location of the tumor but may include abdominal pain or swelling, constipation, nausea, vomiting, and irregular menstrual periods in females. Treatment typically involves surgical removal of the tumor, followed by chemotherapy to kill any remaining cancer cells. The prognosis for EST depends on several factors, including the stage of the disease at diagnosis, the patient's age, and the response to treatment.

Oogonia are the diploid stem cells that are present in the ovary and give rise to oocytes (haploid cells) through the process of mitosis. These oocytes have the potential to develop into mature eggs or ova during female fetal development and after birth, which is a unique characteristic of human female reproduction. The oogonia are enclosed within primordial follicles that protect and nourish them as they develop into oocytes.

It's worth noting that in contrast to males, who continue to produce sperm throughout their reproductive lives, females are born with a finite number of oocytes already present in their ovaries, which is typically around 1-2 million at birth. Over time, this number decreases due to natural attrition and ovulation, leaving only about 400,000 oocytes by puberty, and declining further with age until menopause when the supply of oocytes is depleted.

"Sex differentiation" is a term used in the field of medicine, specifically in reproductive endocrinology and genetics. It refers to the biological development of sexual characteristics that distinguish males from females. This process is regulated by hormones and genetic factors.

There are two main stages of sex differentiation: genetic sex determination and gonadal sex differentiation. Genetic sex determination occurs at fertilization, where the combination of X and Y chromosomes determines the sex of the individual (typically, XX = female and XY = male). Gonadal sex differentiation then takes place during fetal development, where the genetic sex signals the development of either ovaries or testes.

Once the gonads are formed, they produce hormones that drive further sexual differentiation, leading to the development of internal reproductive structures (such as the uterus and fallopian tubes in females, and the vas deferens and seminal vesicles in males) and external genitalia.

It's important to note that while sex differentiation is typically categorized as male or female, there are individuals who may have variations in their sexual development, leading to intersex conditions. These variations can occur at any stage of the sex differentiation process and can result in a range of physical characteristics that do not fit neatly into male or female categories.

Nuclear Receptor Subfamily 6, Group A, Member 1 (NR6A1) is a gene that encodes for the steroidogenic factor-1 (SF-1) protein, which is a member of the nuclear receptor superfamily. These proteins are transcription factors that regulate gene expression by binding to specific DNA sequences.

The SF-1 protein plays critical roles in the development and function of the endocrine system, including the regulation of steroid hormone biosynthesis, gonadal development, and reproductive function. Mutations in the NR6A1 gene have been associated with several genetic disorders, such as congenital adrenal hyperplasia, primary ovarian insufficiency, and XY female disorder of sex development.

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.

A tooth germ is a small cluster of cells that eventually develop into a tooth. It contains the dental papilla, which will become the dentin and pulp of the tooth, and the dental follicle, which will form the periodontal ligament, cementum, and alveolar bone. The tooth germ starts as an epithelial thickening called the dental lamina, which then forms a bud, cap, and bell stage before calcification occurs and the tooth begins to erupt through the gums. It is during the bell stage that the enamel organ, which will form the enamel of the tooth, is formed.

Male infertility is a condition characterized by the inability to cause pregnancy in a fertile female. It is typically defined as the failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse.

The causes of male infertility can be varied and include issues with sperm production, such as low sperm count or poor sperm quality, problems with sperm delivery, such as obstructions in the reproductive tract, or hormonal imbalances that affect sperm production. Other factors that may contribute to male infertility include genetic disorders, environmental exposures, lifestyle choices, and certain medical conditions or treatments.

It is important to note that male infertility can often be treated or managed with medical interventions, such as medication, surgery, or assisted reproductive technologies (ART). A healthcare provider can help diagnose the underlying cause of male infertility and recommend appropriate treatment options.

Cryptorchidism is a medical condition in which one or both of a male infant's testicles fail to descend from the abdomen into the scrotum before birth or within the first year of life. Normally, the testicles descend from the abdomen into the scrotum during fetal development in the second trimester. If the testicles do not descend on their own, medical intervention may be necessary to correct the condition.

Cryptorchidism is a common birth defect, affecting about 3-5% of full-term and 30% of preterm male infants. In most cases, the testicle will descend on its own within the first six months of life. If it does not, treatment may be necessary to prevent complications such as infertility, testicular cancer, and inguinal hernia.

Treatment for cryptorchidism typically involves surgery to bring the testicle down into the scrotum. This procedure is called orchiopexy and is usually performed before the age of 2. In some cases, hormonal therapy may be used as an alternative to surgery. However, this approach has limited success and is generally only recommended in certain situations.

Overall, cryptorchidism is a treatable condition that can help prevent future health problems if addressed early on. Regular check-ups with a pediatrician or healthcare provider can help ensure timely diagnosis and treatment of this condition.

Mediastinal neoplasms refer to abnormal growths or tumors located in the mediastinum, which is the central compartment of the thoracic cavity that lies between the lungs and contains various vital structures such as the heart, esophagus, trachea, blood vessels, lymph nodes, and nerves. Mediastinal neoplasms can be benign (non-cancerous) or malignant (cancerous), and they can arise from any of the tissues or organs within the mediastinum.

Benign mediastinal neoplasms may include thymomas, lipomas, neurofibromas, or teratomas, among others. These tumors are typically slow-growing and rarely spread to other parts of the body. However, they can still cause symptoms or complications by compressing adjacent structures within the mediastinum, such as the airways, blood vessels, or nerves.

Malignant mediastinal neoplasms are cancerous tumors that can invade and destroy surrounding tissues and may spread (metastasize) to other parts of the body. Common types of malignant mediastinal neoplasms include thymic carcinomas, lymphomas, germ cell tumors, and neuroendocrine tumors. These tumors often require aggressive treatment, such as surgery, radiation therapy, and chemotherapy, to control their growth and spread.

It is important to note that mediastinal neoplasms can present with various symptoms depending on their location, size, and type. Some patients may be asymptomatic, while others may experience cough, chest pain, difficulty breathing, hoarseness, or swallowing difficulties. A thorough diagnostic workup, including imaging studies and biopsies, is necessary to confirm the diagnosis and determine the best course of treatment for mediastinal neoplasms.

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.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

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.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

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.

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.

Retroperitoneal neoplasms refer to abnormal growths or tumors that develop in the retroperitoneal space. This is the area located behind the peritoneum, which is the membrane that lines the abdominal cavity and covers the abdominal organs. The retroperitoneal space contains several vital structures such as the kidneys, adrenal glands, pancreas, aorta, and lymphatic vessels.

Retroperitoneal neoplasms can be benign or malignant (cancerous). Malignant retroperitoneal neoplasms are often aggressive and can invade surrounding tissues and organs, leading to various complications. Common types of retroperitoneal neoplasms include lymphomas, sarcomas, and metastatic tumors from other primary sites. Symptoms may vary depending on the size and location of the tumor but can include abdominal or back pain, weight loss, and swelling in the legs. Diagnosis typically involves imaging studies such as CT scans or MRI, followed by a biopsy to determine the type and grade of the tumor. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

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.

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.

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.

A nonmammalian embryo refers to the developing organism in animals other than mammals, from the fertilized egg (zygote) stage until hatching or birth. In nonmammalian species, the developmental stages and terminology differ from those used in mammals. The term "embryo" is generally applied to the developing organism up until a specific stage of development that is characterized by the formation of major organs and structures. After this point, the developing organism is referred to as a "larva," "juvenile," or other species-specific terminology.

The study of nonmammalian embryos has played an important role in our understanding of developmental biology and evolutionary developmental biology (evo-devo). By comparing the developmental processes across different animal groups, researchers can gain insights into the evolutionary origins and diversification of body plans and structures. Additionally, nonmammalian embryos are often used as model systems for studying basic biological processes, such as cell division, gene regulation, and pattern formation.

Sperm count, also known as sperm concentration, is the number of sperm present in a given volume of semen. The World Health Organization (WHO) previously defined a normal sperm count as at least 20 million sperm per milliliter of semen. However, more recent studies suggest that fertility may be affected even when sperm counts are slightly lower than this threshold. It's important to note that sperm count is just one factor among many that can influence male fertility. Other factors, such as sperm motility (the ability of sperm to move properly) and morphology (the shape of the sperm), also play crucial roles in successful conception.

'Caenorhabditis elegans' is a species of free-living, transparent nematode (roundworm) that is widely used as a model organism in scientific research, particularly in the fields of biology and genetics. It has a simple anatomy, short lifespan, and fully sequenced genome, making it an ideal subject for studying various biological processes and diseases.

Some notable features of C. elegans include:

* Small size: Adult hermaphrodites are about 1 mm in length.
* Short lifespan: The average lifespan of C. elegans is around 2-3 weeks, although some strains can live up to 4 weeks under laboratory conditions.
* Development: C. elegans has a well-characterized developmental process, with adults developing from eggs in just 3 days at 20°C.
* Transparency: The transparent body of C. elegans allows researchers to observe its internal structures and processes easily.
* Genetics: C. elegans has a fully sequenced genome, which contains approximately 20,000 genes. Many of these genes have human homologs, making it an excellent model for studying human diseases.
* Neurobiology: C. elegans has a simple nervous system, with only 302 neurons in the hermaphrodite and 383 in the male. This simplicity makes it an ideal organism for studying neural development, function, and behavior.

Research using C. elegans has contributed significantly to our understanding of various biological processes, including cell division, apoptosis, aging, learning, and memory. Additionally, studies on C. elegans have led to the discovery of many genes associated with human diseases such as cancer, neurodegenerative disorders, and metabolic conditions.

"Sex determination processes" refer to the series of genetic and biological events that occur during embryonic and fetal development which lead to the development of male or female physical characteristics. In humans, this process is typically determined by the presence or absence of a Y chromosome in the fertilized egg. If the egg has a Y chromosome, it will develop into a male (genetically XY) and if it does not have a Y chromosome, it will develop into a female (genetically XX).

The sex determination process involves the activation and repression of specific genes on the sex chromosomes, which direct the development of the gonads (ovaries or testes) and the production of hormones that influence the development of secondary sexual characteristics. This includes the development of internal and external genitalia, as well as other sex-specific physical traits.

It is important to note that while sex is typically determined by genetics and biology, gender identity is a separate construct that can be self-identified and may not align with an individual's biological sex.

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.

The Blood-Testis Barrier (BTB) is a unique structural and functional feature of the seminiferous epithelium in the testes, which forms a tight junction between adjacent Sertoli cells in the semi-niferous tubules. This barrier selectively restricts the passage of molecules, including potentially harmful substances and immune cells, from the systemic circulation into the adluminal compartment of the seminiferous epithelium where spermatogenesis occurs. This helps to maintain a immunologically privileged microenvironment that is essential for the survival and maturation of developing sperm cells, preventing an immune response against them. The BTB also regulates the movement of molecules required for spermatogenesis, such as nutrients, hormones, and signaling molecules, from the basal compartment to the adluminal compartment.

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.

The pachytene stage is a phase in the meiotic division of sex cells (gametes) such as sperm and egg cells, specifically during prophase I. In this stage, homologous chromosomes are fully paired and have formed tetrads, or four-stranded structures called chiasma where genetic recombination occurs between the non-sister chromatids of each homologous chromosome. This is a crucial step in the creation of genetic diversity in the offspring. The pachytene stage is characterized by the presence of a protein matrix called the synaptonemal complex, which holds the homologous chromosomes together and facilitates crossing over.

'Drosophila proteins' refer to the proteins that are expressed in the fruit fly, Drosophila melanogaster. This organism is a widely used model system in genetics, developmental biology, and molecular biology research. The study of Drosophila proteins has contributed significantly to our understanding of various biological processes, including gene regulation, cell signaling, development, and aging.

Some examples of well-studied Drosophila proteins include:

1. HSP70 (Heat Shock Protein 70): A chaperone protein involved in protein folding and protection from stress conditions.
2. TUBULIN: A structural protein that forms microtubules, important for cell division and intracellular transport.
3. ACTIN: A cytoskeletal protein involved in muscle contraction, cell motility, and maintenance of cell shape.
4. BETA-GALACTOSIDASE (LACZ): A reporter protein often used to monitor gene expression patterns in transgenic flies.
5. ENDOGLIN: A protein involved in the development of blood vessels during embryogenesis.
6. P53: A tumor suppressor protein that plays a crucial role in preventing cancer by regulating cell growth and division.
7. JUN-KINASE (JNK): A signaling protein involved in stress response, apoptosis, and developmental processes.
8. DECAPENTAPLEGIC (DPP): A member of the TGF-β (Transforming Growth Factor Beta) superfamily, playing essential roles in embryonic development and tissue homeostasis.

These proteins are often studied using various techniques such as biochemistry, genetics, molecular biology, and structural biology to understand their functions, interactions, and regulation within the cell.

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.

'Caenorhabditis elegans' (C. elegans) is a type of free-living, transparent nematode (roundworm) that is often used as a model organism in scientific research. C. elegans proteins refer to the various types of protein molecules that are produced by the organism's genes and play crucial roles in maintaining its biological functions.

Proteins are complex molecules made up of long chains of amino acids, and they are involved in virtually every cellular process, including metabolism, DNA replication, signal transduction, and transportation of molecules within the cell. In C. elegans, proteins are encoded by genes, which are transcribed into messenger RNA (mRNA) molecules that are then translated into protein sequences by ribosomes.

Studying C. elegans proteins is important for understanding the basic biology of this organism and can provide insights into more complex biological systems, including humans. Because C. elegans has a relatively simple nervous system and a short lifespan, it is often used to study neurobiology, aging, and development. Additionally, because many of the genes and proteins in C. elegans have counterparts in other organisms, including humans, studying them can provide insights into human disease processes and potential therapeutic targets.

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).

Choriocarcinoma is a rapidly growing and invasive type of gestational trophoblastic disease (GTD), which are abnormal growths that develop in the tissues that are supposed to become the placenta during pregnancy. It occurs when a malignant tumor develops from trophoblast cells, which are normally found in the developing embryo and help to form the placenta.

Choriocarcinoma can occur after any type of pregnancy, including normal pregnancies, molar pregnancies (a rare mass that forms inside the uterus after conception), or ectopic pregnancies (when a fertilized egg implants outside the uterus). It is characterized by the presence of both trophoblastic and cancerous cells, which can produce human chorionic gonadotropin (hCG) hormone.

Choriocarcinoma can spread quickly to other parts of the body, such as the lungs, liver, brain, or vagina, through the bloodstream. It is important to diagnose and treat choriocarcinoma early to prevent serious complications and improve the chances of a successful treatment outcome. Treatment typically involves surgery, chemotherapy, or radiation therapy.

Alpha-fetoprotein (AFP) is a protein produced by the yolk sac and the liver during fetal development. In adults, AFP is normally present in very low levels in the blood. However, abnormal production of AFP can occur in certain medical conditions, such as:

* Liver cancer or hepatocellular carcinoma (HCC)
* Germ cell tumors, including non-seminomatous testicular cancer and ovarian cancer
* Hepatitis or liver inflammation
* Certain types of benign liver disease, such as cirrhosis or hepatic adenomas

Elevated levels of AFP in the blood can be detected through a simple blood test. This test is often used as a tumor marker to help diagnose and monitor certain types of cancer, particularly HCC. However, it's important to note that an elevated AFP level alone is not enough to diagnose cancer, and further testing is usually needed to confirm the diagnosis. Additionally, some non-cancerous conditions can also cause elevated AFP levels, so it's important to interpret the test results in the context of the individual's medical history and other diagnostic tests.

Bleomycin is a type of chemotherapeutic agent used to treat various types of cancer, including squamous cell carcinoma, testicular cancer, and lymphomas. It works by causing DNA damage in rapidly dividing cells, which can inhibit the growth and proliferation of cancer cells.

Bleomycin is an antibiotic derived from Streptomyces verticillus and is often administered intravenously or intramuscularly. While it can be effective in treating certain types of cancer, it can also have serious side effects, including lung toxicity, which can lead to pulmonary fibrosis and respiratory failure. Therefore, bleomycin should only be used under the close supervision of a healthcare professional who is experienced in administering chemotherapy drugs.

'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.

Fertility is the natural ability to conceive or to cause conception of offspring. In humans, it is the capacity of a woman and a man to reproduce through sexual reproduction. For women, fertility usually takes place during their reproductive years, which is from adolescence until menopause. A woman's fertility depends on various factors including her age, overall health, and the health of her reproductive system.

For men, fertility can be affected by a variety of factors such as age, genetics, general health, sexual function, and environmental factors that may affect sperm production or quality. Factors that can negatively impact male fertility include exposure to certain chemicals, radiation, smoking, alcohol consumption, drug use, and sexually transmitted infections (STIs).

Infertility is a common medical condition affecting about 10-15% of couples trying to conceive. Infertility can be primary or secondary. Primary infertility refers to the inability to conceive after one year of unprotected sexual intercourse, while secondary infertility refers to the inability to conceive following a previous pregnancy.

Infertility can be treated with various medical and surgical interventions depending on the underlying cause. These may include medications to stimulate ovulation, intrauterine insemination (IUI), in vitro fertilization (IVF), or surgery to correct anatomical abnormalities.

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.

DEAD-box RNA helicases are a family of proteins that are involved in unwinding RNA secondary structures and displacing proteins bound to RNA molecules. They get their name from the conserved amino acid sequence motif "DEAD" (Asp-Glu-Ala-Asp) found within their catalytic core, which is responsible for ATP-dependent helicase activity. These enzymes play crucial roles in various aspects of RNA metabolism, including pre-mRNA splicing, ribosome biogenesis, translation initiation, and RNA decay. DEAD-box helicases are also implicated in a number of human diseases, such as cancer and neurological disorders.

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.

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.

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.

"Drosophila" is a genus of small flies, also known as fruit flies. The most common species used in scientific research is "Drosophila melanogaster," which has been a valuable model organism for many areas of biological and medical research, including genetics, developmental biology, neurobiology, and aging.

The use of Drosophila as a model organism has led to numerous important discoveries in genetics and molecular biology, such as the identification of genes that are associated with human diseases like cancer, Parkinson's disease, and obesity. The short reproductive cycle, large number of offspring, and ease of genetic manipulation make Drosophila a powerful tool for studying complex biological processes.

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.

Disorders of Sex Development (DSD) are a group of conditions that occur when there is a difference in the development and assignment of sex characteristics. These differences may be apparent at birth, at puberty, or later in life. DSD can affect chromosomes, gonads, genitals, or secondary sexual characteristics, and can result from genetic mutations or environmental factors during fetal development.

DSDs were previously referred to as "intersex" conditions, but the term "Disorders of Sex Development" is now preferred in medical settings because it is more descriptive and less stigmatizing. DSDs are not errors or abnormalities, but rather variations in human development that require sensitive and individualized care.

The diagnosis and management of DSD can be complex and may involve a team of healthcare providers, including endocrinologists, urologists, gynecologists, psychologists, and genetic counselors. Treatment options depend on the specific type of DSD and may include hormone therapy, surgery, or other interventions to support physical and emotional well-being.

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.

Testosterone is a steroid hormone that belongs to androsten class of hormones. It is primarily secreted by the Leydig cells in the testes of males and, to a lesser extent, by the ovaries and adrenal glands in females. Testosterone is the main male sex hormone and anabolic steroid. It plays a key role in the development of masculine characteristics, such as body hair and muscle mass, and contributes to bone density, fat distribution, red cell production, and sex drive. In females, testosterone contributes to sexual desire and bone health. Testosterone is synthesized from cholesterol and its production is regulated by luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

Orchitis is a medical condition characterized by inflammation of one or both testicles, usually caused by an infection. The most common cause of orchitis is a bacterial infection that spreads from the epididymis, resulting in a condition known as epididymo-orchitis. However, viral infections such as mumps can also lead to orchitis. Symptoms may include sudden and severe pain in the testicle(s), swelling, warmth, redness of the overlying skin, nausea, vomiting, and fever. Treatment typically involves antibiotics for bacterial infections and supportive care for symptom relief. If left untreated, orchitis can lead to complications such as infertility or testicular atrophy.

Mesonephroma is a very rare type of kidney tumor that originates from the mesonephric duct remnants, which are the embryonic precursors of the male reproductive system. This tumor typically affects older adults and is more common in men than women.

Mesonephromas are usually slow-growing and asymptomatic, making them difficult to detect at an early stage. When symptoms do occur, they may include flank pain, hematuria (blood in the urine), a palpable abdominal mass, and weight loss.

On imaging studies such as CT or MRI scans, mesonephromas typically appear as well-circumscribed masses within the kidney. The diagnosis is usually confirmed through a biopsy or surgical excision of the tumor.

Mesonephromas are composed of tubular structures lined with cuboidal to low columnar epithelial cells, often with clear cytoplasm. They may also contain areas of necrosis and hemorrhage. The treatment of mesonephroma typically involves surgical excision, and the prognosis is generally favorable, with a low risk of recurrence or metastasis. However, long-term follow-up is recommended due to the rarity and limited data on this type of tumor.

The epididymis is a tightly coiled tube located on the upper and posterior portion of the testicle that serves as the site for sperm maturation and storage. It is an essential component of the male reproductive system. The epididymis can be divided into three parts: the head (where newly produced sperm enter from the testicle), the body, and the tail (where mature sperm exit and are stored). Any abnormalities or inflammation in the epididymis may lead to discomfort, pain, or infertility.

I'm sorry for any confusion, but there isn't a medical definition for "RNA, Messenger, Stored" as it is not a standard medical term. However, I can provide information on the individual components:

1. RNA (Ribonucleic Acid): This is a type of nucleic acid that plays several important roles in biological systems, including coding, decoding, regulation, and expression of genes. There are several types of RNA, including messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA).

2. Messenger RNA (mRNA): This is the RNA molecule 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. After being processed in the nucleus, mRNA moves out into the cytoplasm, where it serves as a template for protein synthesis.

3. Stored: In the context of biology, this term isn't typically associated with RNA or mRNA. Generally, mRNA is not "stored" in cells but rather is quickly translated into proteins after it is produced. There are some exceptions, such as in egg cells, where mRNAs can be stored and then used for protein synthesis after fertilization.

I hope this helps clarify the concepts! If you have any further questions or need more information, please don't hesitate to ask.

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.

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.

Cisplatin is a chemotherapeutic agent used to treat various types of cancers, including testicular, ovarian, bladder, head and neck, lung, and cervical cancers. It is an inorganic platinum compound that contains a central platinum atom surrounded by two chloride atoms and two ammonia molecules in a cis configuration.

Cisplatin works by forming crosslinks between DNA strands, which disrupts the structure of DNA and prevents cancer cells from replicating. This ultimately leads to cell death and slows down or stops the growth of tumors. However, cisplatin can also cause damage to normal cells, leading to side effects such as nausea, vomiting, hearing loss, and kidney damage. Therefore, it is essential to monitor patients closely during treatment and manage any adverse effects promptly.

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 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.

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.

Testicular diseases refer to a range of conditions that affect the testicles, the male reproductive organs located in the scrotum. These diseases can affect either one or both testicles and may cause pain, swelling, or impact fertility. Here are some examples of testicular diseases:

1. Testicular cancer: A malignant tumor that develops in the testicle. It is a relatively rare cancer but is highly treatable if detected early.
2. Testicular torsion: A surgical emergency that occurs when the spermatic cord, which supplies blood to the testicle, becomes twisted, cutting off the blood flow.
3. Epididymitis: An infection or inflammation of the epididymis, a coiled tube that stores and carries sperm from the testicle.
4. Orchitis: An infection or inflammation of the testicle itself. It can occur on its own or as a complication of mumps.
5. Hydrocele: A fluid-filled sac that forms around the testicle, causing swelling.
6. Varicocele: Enlarged veins in the scrotum that can cause pain and affect fertility.
7. Inguinal hernia: A condition where a portion of the intestine or fat protrudes through a weakened area in the abdominal wall, often appearing as a bulge in the groin or scrotum.
8. Testicular trauma: Injury to the testicle, which can result from accidents, sports injuries, or other causes.
9. Undescended testicles: A condition where one or both testicles fail to descend from the abdomen into the scrotum before birth.

It is essential for men to perform regular self-examinations to check for any unusual lumps, swelling, or pain in the testicles and seek medical attention if they notice any changes.

In situ nick-end labeling (ISEL, also known as TUNEL) is a technique used in pathology and molecular biology to detect DNA fragmentation, which is a characteristic of apoptotic cells (cells undergoing programmed cell death). The method involves labeling the 3'-hydroxyl termini of double or single stranded DNA breaks in situ (within tissue sections or individual cells) using modified nucleotides that are coupled to a detectable marker, such as a fluorophore or an enzyme. This technique allows for the direct visualization and quantification of apoptotic cells within complex tissues or cell populations.

Sex determination analysis is a medical or biological examination used to establish the genetic or phenotypic sex of an individual. This can be done through various methods, including:

1. Genetic testing: Examination of an individual's DNA to identify the presence of specific sex chromosomes (XX for females and XY for males). This is typically performed through a blood or tissue sample.
2. Chromosomal analysis: Microscopic examination of an individual's chromosomes to determine their number and structure. In humans, females typically have 46 chromosomes, including two X chromosomes (46,XX), while males typically have 46 chromosomes, including one X and one Y chromosome (46,XY).
3. Phenotypic analysis: Observation of an individual's physical characteristics, such as the presence or absence of certain sex organs or secondary sexual characteristics, to determine their phenotypic sex.

Sex determination analysis is used in various medical and research contexts, including prenatal testing, diagnosis of disorders of sex development (DSDs), forensic investigations, and population studies. It's important to note that while sex determination analysis can provide information about an individual's genetic or phenotypic sex, it does not necessarily reflect their gender identity, which is a personal sense of being male, female, or something else.

I apologize for any confusion, but "Turbellaria" is not a medical term. It is a taxonomic category in biology, specifically a class within the phylum Platyhelminthes (flatworms). Turbellarians are free-living, flatworms that are typically characterized by their unsegmented body and the presence of cilia for locomotion. They include freshwater, marine, and terrestrial species. If you have a medical term or concept in mind, I would be happy to help define it for you.

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.

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.

'Drosophila melanogaster' is the scientific name for a species of fruit fly that is commonly used as a model organism in various fields of biological research, including genetics, developmental biology, and evolutionary biology. Its small size, short generation time, large number of offspring, and ease of cultivation make it an ideal subject for laboratory studies. The fruit fly's genome has been fully sequenced, and many of its genes have counterparts in the human genome, which facilitates the understanding of genetic mechanisms and their role in human health and disease.

Here is a brief medical definition:

Drosophila melanogaster (droh-suh-fih-luh meh-lon-guh-ster): A species of fruit fly used extensively as a model organism in genetic, developmental, and evolutionary research. Its genome has been sequenced, revealing many genes with human counterparts, making it valuable for understanding genetic mechanisms and their role in human health and disease.

"Oryzias" is not a medical term, but a genus name in the family Adrianichthyidae, which includes various species of small fish commonly known as "ricefishes" or "medaka." These fish are often used in scientific research, particularly in the fields of genetics and developmental biology. They are not associated with human diseases or medical conditions.

The X chromosome is one of the two types of sex-determining chromosomes in humans (the other being the Y chromosome). It's one of the 23 pairs of chromosomes that make up a person's genetic material. Females typically have two copies of the X chromosome (XX), while males usually have one X and one Y chromosome (XY).

The X chromosome contains hundreds of genes that are responsible for the production of various proteins, many of which are essential for normal bodily functions. Some of the critical roles of the X chromosome include:

1. Sex Determination: The presence or absence of the Y chromosome determines whether an individual is male or female. If there is no Y chromosome, the individual will typically develop as a female.
2. Genetic Disorders: Since females have two copies of the X chromosome, they are less likely to be affected by X-linked genetic disorders than males. Males, having only one X chromosome, will express any recessive X-linked traits they inherit.
3. Dosage Compensation: To compensate for the difference in gene dosage between males and females, a process called X-inactivation occurs during female embryonic development. One of the two X chromosomes is randomly inactivated in each cell, resulting in a single functional copy per cell.

The X chromosome plays a crucial role in human genetics and development, contributing to various traits and characteristics, including sex determination and dosage compensation.

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.

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.

Haploidy is a term used in genetics to describe the condition of having half the normal number of chromosomes in a cell or an organism. In humans, for example, a haploid cell contains 23 chromosomes, whereas a diploid cell has 46 chromosomes.

Haploid cells are typically produced through a process called meiosis, which is a type of cell division that occurs in the reproductive organs of sexually reproducing organisms. During meiosis, a diploid cell undergoes two rounds of division to produce four haploid cells, each containing only one set of chromosomes.

In humans, haploid cells are found in the sperm and egg cells, which fuse together during fertilization to create a diploid zygote with 46 chromosomes. Haploidy is important for maintaining the correct number of chromosomes in future generations and preventing genetic abnormalities that can result from having too many or too few chromosomes.

"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.

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.

Meiotic Prophase I is a stage in the meiotic division of cellular reproduction that results in the formation of gametes or sex cells (sperm and egg). It is the first of five stages in Meiosis I, which is a type of cell division that reduces the chromosome number by half.

During Meiotic Prophase I, homologous chromosomes pair and form tetrads (four-stranded structures), which then undergo genetic recombination or crossing over, resulting in new combinations of alleles on the chromatids of each homologous chromosome. This stage can be further divided into several substages: leptonema, zygonema, pachynema, diplonema, and diakinesis. These substages are characterized by distinct changes in chromosome structure and behavior, including the condensation and movement of the chromosomes, as well as the formation and dissolution of the synaptonemal complex, a protein structure that holds the homologous chromosomes together during crossing over.

Overall, Meiotic Prophase I is a critical stage in meiosis that ensures genetic diversity in offspring by shuffling the genetic material between homologous chromosomes and creating new combinations of alleles.

The retroperitoneal space refers to the area within the abdominal cavity that is located behind (retro) the peritoneum, which is the smooth serous membrane that lines the inner wall of the abdomen and covers the abdominal organs. This space is divided into several compartments and contains vital structures such as the kidneys, adrenal glands, pancreas, duodenum, aorta, and vena cava.

The retroperitoneal space can be further categorized into two regions:

1. The posterior pararenal space, which is lateral to the psoas muscle and contains fat tissue.
2. The perirenal space, which surrounds the kidneys and adrenal glands and is filled with fatty connective tissue.

Disorders or conditions affecting the retroperitoneal space may include infections, tumors, hematomas, or inflammation, which can lead to various symptoms depending on the specific structures involved. Imaging techniques such as CT scans or MRI are commonly used to diagnose and assess retroperitoneal pathologies.

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.

A zebrafish is a freshwater fish species belonging to the family Cyprinidae and the genus Danio. Its name is derived from its distinctive striped pattern that resembles a zebra's. Zebrafish are often used as model organisms in scientific research, particularly in developmental biology, genetics, and toxicology studies. They have a high fecundity rate, transparent embryos, and a rapid development process, making them an ideal choice for researchers. However, it is important to note that providing a medical definition for zebrafish may not be entirely accurate or relevant since they are primarily used in biological research rather than clinical medicine.

Etoposide is a chemotherapy medication used to treat various types of cancer, including lung cancer, testicular cancer, and certain types of leukemia. It works by inhibiting the activity of an enzyme called topoisomerase II, which is involved in DNA replication and transcription. By doing so, etoposide can interfere with the growth and multiplication of cancer cells.

Etoposide is often administered intravenously in a hospital or clinic setting, although it may also be given orally in some cases. The medication can cause a range of side effects, including nausea, vomiting, hair loss, and an increased risk of infection. It can also have more serious side effects, such as bone marrow suppression, which can lead to anemia, bleeding, and a weakened immune system.

Like all chemotherapy drugs, etoposide is not without risks and should only be used under the close supervision of a qualified healthcare provider. It is important for patients to discuss the potential benefits and risks of this medication with their doctor before starting treatment.

Genitalia, also known as the genitals, refer to the reproductive organs located in the pelvic region. In males, these include the penis and testicles, while in females, they consist of the vulva, vagina, clitoris, and ovaries. Genitalia are essential for sexual reproduction and can also be associated with various medical conditions, such as infections, injuries, or congenital abnormalities.

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.

The blastoderm is the layer of cells that forms on the surface of a developing embryo, during the blastula stage of embryonic development. In mammals, this layer of cells is also known as the epiblast. The blastoderm is responsible for giving rise to all of the tissues and organs of the developing organism. It is formed by the cleavage of the fertilized egg, or zygote, and is typically a single layer of cells that surrounds a fluid-filled cavity called the blastocoel. The blastoderm plays a critical role in the early stages of embryonic development, and any disruptions to its formation or function can lead to developmental abnormalities or death of the embryo.

Organ size refers to the volume or physical measurement of an organ in the body of an individual. It can be described in terms of length, width, and height or by using specialized techniques such as imaging studies (like CT scans or MRIs) to determine the volume. The size of an organ can vary depending on factors such as age, sex, body size, and overall health status. Changes in organ size may indicate various medical conditions, including growths, inflammation, or atrophy.

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.

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.

"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.

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.

Genetically modified animals (GMAs) are those whose genetic makeup has been altered using biotechnological techniques. This is typically done by introducing one or more genes from another species into the animal's genome, resulting in a new trait or characteristic that does not naturally occur in that species. The introduced gene is often referred to as a transgene.

The process of creating GMAs involves several steps:

1. Isolation: The desired gene is isolated from the DNA of another organism.
2. Transfer: The isolated gene is transferred into the target animal's cells, usually using a vector such as a virus or bacterium.
3. Integration: The transgene integrates into the animal's chromosome, becoming a permanent part of its genetic makeup.
4. Selection: The modified cells are allowed to multiply, and those that contain the transgene are selected for further growth and development.
5. Breeding: The genetically modified individuals are bred to produce offspring that carry the desired trait.

GMAs have various applications in research, agriculture, and medicine. In research, they can serve as models for studying human diseases or testing new therapies. In agriculture, GMAs can be developed to exhibit enhanced growth rates, improved disease resistance, or increased nutritional value. In medicine, GMAs may be used to produce pharmaceuticals or other therapeutic agents within their bodies.

Examples of genetically modified animals include mice with added genes for specific proteins that make them useful models for studying human diseases, goats that produce a human protein in their milk to treat hemophilia, and pigs with enhanced resistance to certain viruses that could potentially be used as organ donors for humans.

It is important to note that the use of genetically modified animals raises ethical concerns related to animal welfare, environmental impact, and potential risks to human health. These issues must be carefully considered and addressed when developing and implementing GMA technologies.

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.

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.

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.

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.

The Y chromosome is one of the two sex-determining chromosomes in humans and many other animals, along with the X chromosome. The Y chromosome contains the genetic information that helps to determine an individual's sex as male. It is significantly smaller than the X chromosome and contains fewer genes.

The Y chromosome is present in males, who inherit it from their father. Females, on the other hand, have two X chromosomes, one inherited from each parent. The Y chromosome includes a gene called SRY (sex-determining region Y), which initiates the development of male sexual characteristics during embryonic development.

It is worth noting that the Y chromosome has a relatively high rate of genetic mutation and degeneration compared to other chromosomes, leading to concerns about its long-term viability in human evolution. However, current evidence suggests that the Y chromosome has been stable for at least the past 25 million years.

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.

Klinefelter Syndrome: A genetic disorder in males, caused by the presence of one or more extra X chromosomes, typically resulting in XXY karyotype. It is characterized by small testes, infertility, gynecomastia (breast enlargement), tall stature, and often mild to moderate intellectual disability. The symptoms can vary greatly among individuals with Klinefelter Syndrome. Some men may not experience any significant health problems and may never be diagnosed, while others may have serious medical or developmental issues that require treatment. It is one of the most common chromosomal disorders, affecting about 1 in every 500-1,000 newborn males.

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.

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.

Mitosis is a type of cell division in which the genetic material of a single cell, called the mother cell, is equally distributed into two identical daughter cells. It's a fundamental process that occurs in multicellular organisms for growth, maintenance, and repair, as well as in unicellular organisms for reproduction.

The process of mitosis can be broken down into several stages: prophase, prometaphase, metaphase, anaphase, and telophase. During prophase, the chromosomes condense and become visible, and the nuclear envelope breaks down. In prometaphase, the nuclear membrane is completely disassembled, and the mitotic spindle fibers attach to the chromosomes at their centromeres.

During metaphase, the chromosomes align at the metaphase plate, an imaginary line equidistant from the two spindle poles. In anaphase, sister chromatids are pulled apart by the spindle fibers and move toward opposite poles of the cell. Finally, in telophase, new nuclear envelopes form around each set of chromosomes, and the chromosomes decondense and become less visible.

Mitosis is followed by cytokinesis, a process that divides the cytoplasm of the mother cell into two separate daughter cells. The result of mitosis and cytokinesis is two genetically identical cells, each with the same number and kind of chromosomes as the original parent cell.

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.

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.

'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.

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.

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.

Contraceptive agents for males are substances or methods that are used to prevent pregnancy by reducing the likelihood of fertilization. These can include:

1. Barrier methods: Condoms, diaphragms, and spermicides create a physical barrier that prevents sperm from reaching the egg.
2. Hormonal methods: Testosterone and progestin hormone therapies can decrease sperm production and reduce fertility.
3. Intrauterine devices (IUDs) for men: These are still in the experimental stage, but they involve placing a device in the male reproductive tract to prevent sperm from reaching the female reproductive system.
4. Withdrawal method: This involves the man withdrawing his penis from the vagina before ejaculation, although this is not a highly reliable form of contraception.
5. Fertility awareness methods: These involve tracking the woman's menstrual cycle and avoiding sexual intercourse during her fertile period.
6. Sterilization: Vasectomy is a surgical procedure that blocks or cuts the vas deferens, preventing sperm from leaving the body. It is a permanent form of contraception for men.

It's important to note that no contraceptive method is 100% effective, and individuals should consult with their healthcare provider to determine which option is best for them based on their personal needs, lifestyle, and medical history.

Gonadal dysgenesis is a condition characterized by the abnormal development of the gonads, which are the reproductive organs that produce sex hormones and gametes (sperm or eggs). In individuals with gonadal dysgenesis, the gonads may be underdeveloped, structurally abnormal, or completely absent. This condition can affect people of any gender and is often associated with other genetic disorders, such as Turner or Klinefelter syndromes.

The clinical presentation of gonadal dysgenesis varies widely depending on the severity of the disorder and the presence of other associated conditions. Some individuals may have normal sexual development and fertility, while others may experience delayed puberty, infertility, or ambiguous genitalia. Gonadal dysgenesis can also increase the risk of developing gonadal tumors, particularly in individuals with complete or partial absence of the gonads.

The diagnosis of gonadal dysgenesis is typically made through a combination of clinical evaluation, imaging studies, and genetic testing. Treatment may include hormone replacement therapy to support sexual development and prevent complications associated with hormonal imbalances. In some cases, surgical removal of the gonads may be recommended to reduce the risk of tumor development.

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.

Gonadoblastoma is a rare, typically benign, slow-growing tumor that primarily affects the gonads (ovaries or testes). It most commonly occurs in individuals with disorders of sexual development, particularly those with gonadal dysgenesis and a 46,XY karyotype. The tumor is composed of germ cells and sex cord stromal cells, which differentiate into various cell types found within the gonads.

Gonadoblastomas are usually asymptomatic and are often discovered incidentally during imaging studies or surgical procedures for other conditions. In some cases, they may produce hormones leading to precocious puberty or virilization. Although typically benign, there is a risk of malignant transformation into germ cell tumors such as dysgerminoma, seminoma, or teratoma. Regular follow-up and monitoring are essential for early detection and management of potential complications. Treatment usually involves surgical removal of the affected gonad.

Ifosfamide is an alkylating agent, which is a type of chemotherapy medication. It works by interfering with the DNA of cancer cells, preventing them from dividing and growing. Ifosfamide is used to treat various types of cancers, such as testicular cancer, small cell lung cancer, ovarian cancer, cervical cancer, and certain types of sarcomas.

The medical definition of Ifosfamide is:

Ifosfamide is a synthetic antineoplastic agent, an oxazaphosphorine derivative, with the chemical formula C6H15Cl2N2O2P. It is used in the treatment of various malignancies, including germ cell tumors, sarcomas, lymphomas, and testicular cancer. The drug is administered intravenously and exerts its cytotoxic effects through the alkylation and cross-linking of DNA, leading to the inhibition of DNA replication and transcription. Ifosfamide can cause significant myelosuppression and has been associated with urotoxicity, neurotoxicity, and secondary malignancies. Therefore, it is essential to monitor patients closely during treatment and manage any adverse effects promptly.

"Triticum" is the genus name for a group of cereal grains that includes common wheat (T. aestivum), durum wheat (T. durum), and spelt (T. spelta). These grains are important sources of food for humans, providing carbohydrates, proteins, and various nutrients. They are used to make a variety of foods such as bread, pasta, and breakfast cereals. Triticum species are also known as "wheat" in layman's terms.

Fibroblast Growth Factor 9 (FGF9) is a protein that belongs to the fibroblast growth factor family, which plays crucial roles in various biological processes such as cell survival, proliferation, migration, and differentiation. Specifically, FGF9 is involved in the development of several organs, including the lungs, heart, and reproductive system. It signals through a specific tyrosine kinase receptor called FGFR3 and can also bind to heparin sulfate proteoglycans, which help to stabilize and present the growth factor to its receptor. Mutations in the FGF9 gene have been associated with skeletal malformations, such as achondrogenesis type II and hypochondroplasia.

Antispermatogenic agents are substances or drugs that inhibit or prevent the production of sperm in the testes. These agents can work by various mechanisms, such as interfering with the formation and maturation of sperm cells, damaging sperm DNA, or suppressing the hormones responsible for sperm production.

Examples of antispermatogenic agents include chemotherapy drugs, radiation therapy, and certain medications used to treat prostate cancer or other conditions. Prolonged use of these agents can lead to infertility, so they are often used with caution and only when necessary. It is important to note that the use of antispermatogenic agents should be under the guidance and supervision of a medical professional.

Follicle-Stimulating Hormone (FSH) is a glycoprotein hormone secreted and released by the anterior pituitary gland. In females, it promotes the growth and development of ovarian follicles in the ovary, which ultimately leads to the maturation and release of an egg (ovulation). In males, FSH stimulates the testes to produce sperm. It works in conjunction with luteinizing hormone (LH) to regulate reproductive processes. The secretion of FSH is controlled by the hypothalamic-pituitary-gonadal axis and its release is influenced by the levels of gonadotropin-releasing hormone (GnRH), estrogen, inhibin, and androgens.

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.

Oligospermia is a medical term used to describe a condition in which the semen contains a lower than normal number of sperm. Generally, a sperm count of less than 15 million sperm per milliliter (ml) of semen is considered to be below the normal range.

Oligospermia can make it more difficult for a couple to conceive naturally and may require medical intervention such as intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF). The condition can result from various factors, including hormonal imbalances, genetic abnormalities, varicocele, environmental factors, and certain medications.

It's important to note that oligospermia is not the same as azoospermia, which is a condition where there is no sperm present in the semen at all.

Orchiectomy is a surgical procedure where one or both of the testicles are removed. It is also known as castration. This procedure can be performed for various reasons, including the treatment of testicular cancer, prostate cancer, or other conditions that may affect the testicles. It can also be done to reduce levels of male hormones in the body, such as in the case of transgender women undergoing gender affirming surgery. The specific medical definition may vary slightly depending on the context and the extent of the procedure.

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.

"Genetic crosses" refer to the breeding of individuals with different genetic characteristics to produce offspring with specific combinations of traits. This process is commonly used in genetics research to study the inheritance patterns and function of specific genes.

There are several types of genetic crosses, including:

1. Monohybrid cross: A cross between two individuals that differ in the expression of a single gene or trait.
2. Dihybrid cross: A cross between two individuals that differ in the expression of two genes or traits.
3. Backcross: A cross between an individual from a hybrid population and one of its parental lines.
4. Testcross: A cross between an individual with unknown genotype and a homozygous recessive individual.
5. Reciprocal cross: A cross in which the male and female parents are reversed to determine if there is any effect of sex on the expression of the trait.

These genetic crosses help researchers to understand the mode of inheritance, linkage, recombination, and other genetic phenomena.

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.

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.

Sex chromosomes, often denoted as X and Y, are one of the 23 pairs of human chromosomes found in each cell of the body. Normally, females have two X chromosomes (46,XX), and males have one X and one Y chromosome (46,XY). The sex chromosomes play a significant role in determining the sex of an individual. They contain genes that contribute to physical differences between men and women. Any variations or abnormalities in the number or structure of these chromosomes can lead to various genetic disorders and conditions related to sexual development and reproduction.

Sertoli Cell-Only Syndrome, also known as Del Castillo Syndrome, is a rare condition characterized by the presence of only Sertoli cells in the seminiferous tubules of the testes. These are specialized cells that normally provide support and nourishment to the developing sperm cells. However, in this syndrome, there is an absence of germ cells, which are necessary for sperm production.

The condition can be unilateral or bilateral, meaning it can affect one or both testes. It's important to note that while men with Sertoli Cell-Only Syndrome do not produce sperm, they still produce testosterone, so their secondary sexual characteristics such as facial hair, deep voice, and muscle mass develop normally.

The syndrome is often detected during infertility investigations. While it's associated with infertility, it doesn't necessarily indicate a problem with the person's overall health. However, some studies suggest that men with this condition may have an increased risk of developing testicular cancer, so regular self-examinations and medical check-ups are recommended.

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.

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.

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.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

A hermaphroditic organism is one that has both male and female reproductive structures in the same individual. This means that the organism has both ovaries and testes, or their equivalents, and can produce both sperm and eggs. Hermaphroditism is most commonly found in plants, but it also occurs in some animals, including certain species of snails, slugs, worms, and fish.

It's important to note that true hermaphroditism is different from intersex conditions, which refer to individuals who may have physical or genetic features that do not fit typical binary notions of male or female bodies. Intersex people may have physical characteristics that are not typically associated with male or female anatomy, or they may have chromosomal variations that do not fit the typical pattern of XX (female) or XY (male).

In medical terminology, hermaphroditism is sometimes referred to as "true hermaphroditism" to distinguish it from intersex conditions. However, the term "hermaphrodite" has fallen out of favor in modern medical and social contexts because it is often considered stigmatizing and misleading. Instead, many professionals prefer to use terms like "intersex" or "disorders of sex development" (DSD) to describe individuals with atypical sexual anatomy or chromosomal patterns.

Prophase is the first phase of mitosis, the process by which eukaryotic cells divide and reproduce. During prophase, the chromosomes condense and become visible. The nuclear envelope breaks down, allowing the spindle fibers to attach to the centromeres of each chromatid in the chromosome. This is a critical step in preparing for the separation of genetic material during cell division. Prophase is also marked by the movement of the centrosomes to opposite poles of the cell, forming the mitotic spindle.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

A zygote is the initial cell formed when a sperm fertilizes an egg, also known as an oocyte. This occurs in the process of human reproduction and marks the beginning of a new genetic identity, containing 46 chromosomes - 23 from the sperm and 23 from the egg. The zygote starts the journey of cell division and growth, eventually developing into a blastocyst, then an embryo, and finally a fetus over the course of pregnancy.

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.

Ovarian neoplasms refer to abnormal growths or tumors in the ovary, which can be benign (non-cancerous) or malignant (cancerous). These growths can originate from various cell types within the ovary, including epithelial cells, germ cells, and stromal cells. Ovarian neoplasms are often classified based on their cell type of origin, histological features, and potential for invasive or metastatic behavior.

Epithelial ovarian neoplasms are the most common type and can be further categorized into several subtypes, such as serous, mucinous, endometrioid, clear cell, and Brenner tumors. Some of these epithelial tumors have a higher risk of becoming malignant and spreading to other parts of the body.

Germ cell ovarian neoplasms arise from the cells that give rise to eggs (oocytes) and can include teratomas, dysgerminomas, yolk sac tumors, and embryonal carcinomas. Stromal ovarian neoplasms develop from the connective tissue cells supporting the ovary and can include granulosa cell tumors, thecomas, and fibromas.

It is essential to diagnose and treat ovarian neoplasms promptly, as some malignant forms can be aggressive and potentially life-threatening if not managed appropriately. Regular gynecological exams, imaging studies, and tumor marker tests are often used for early detection and monitoring of ovarian neoplasms. Treatment options may include surgery, chemotherapy, or radiation therapy, depending on the type, stage, and patient's overall health condition.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Infertility is a reproductive health disorder defined as the failure to achieve a clinical pregnancy after 12 months or more of regular, unprotected sexual intercourse or due to an impairment of a person's capacity to reproduce either as an individual or with their partner. It can be caused by various factors in both men and women, including hormonal imbalances, structural abnormalities, genetic issues, infections, age, lifestyle factors, and others. Infertility can have significant emotional and psychological impacts on individuals and couples experiencing it, and medical intervention may be necessary to help them conceive.

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.

Antineoplastic combined chemotherapy protocols refer to a treatment plan for cancer that involves the use of more than one antineoplastic (chemotherapy) drug given in a specific sequence and schedule. The combination of drugs is used because they may work better together to destroy cancer cells compared to using a single agent alone. This approach can also help to reduce the likelihood of cancer cells becoming resistant to the treatment.

The choice of drugs, dose, duration, and frequency are determined by various factors such as the type and stage of cancer, patient's overall health, and potential side effects. Combination chemotherapy protocols can be used in various settings, including as a primary treatment, adjuvant therapy (given after surgery or radiation to kill any remaining cancer cells), neoadjuvant therapy (given before surgery or radiation to shrink the tumor), or palliative care (to alleviate symptoms and prolong survival).

It is important to note that while combined chemotherapy protocols can be effective in treating certain types of cancer, they can also cause significant side effects, including nausea, vomiting, hair loss, fatigue, and an increased risk of infection. Therefore, patients undergoing such treatment should be closely monitored and managed by a healthcare team experienced in administering chemotherapy.

Planarians are not a medical term, but rather a type of flatworms that belong to the phylum Platyhelminthes. They are known for their ability to regenerate and reproduce asexually. Planarians are often studied in the fields of biology and regenerative medicine due to their unique capacity to regrow lost body parts. However, some planarian species can also be parasitic and infect humans, causing diseases such as intestinal schistosomiasis or cercarial dermatitis. Therefore, while planarians themselves are not a medical term, they have relevance to certain medical fields.

Genes in insects refer to the hereditary units of DNA that are passed down from parents to offspring and contain the instructions for the development, function, and reproduction of an organism. These genetic materials are located within the chromosomes in the nucleus of insect cells. They play a crucial role in determining various traits such as physical characteristics, behavior, and susceptibility to diseases.

Insect genes, like those of other organisms, consist of exons (coding regions) that contain information for protein synthesis and introns (non-coding regions) that are removed during the process of gene expression. The expression of insect genes is regulated by various factors such as transcription factors, enhancers, and silencers, which bind to specific DNA sequences to activate or repress gene transcription.

Understanding the genetic makeup of insects has important implications for various fields, including agriculture, public health, and evolutionary biology. For example, genes associated with insect pests' resistance to pesticides can be identified and targeted to develop more effective control strategies. Similarly, genes involved in disease transmission by insect vectors such as mosquitoes can be studied to develop novel interventions for preventing the spread of infectious diseases.

Sexual maturation is the process of physical development during puberty that leads to the ability to reproduce. This process involves the development of primary and secondary sexual characteristics, changes in hormone levels, and the acquisition of reproductive capabilities. In females, this includes the onset of menstruation and the development of breasts and hips. In males, this includes the deepening of the voice, growth of facial hair, and the production of sperm. Achieving sexual maturation is an important milestone in human development and typically occurs during adolescence.

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.

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.

An ovarian follicle is a fluid-filled sac in the ovary that contains an immature egg or ovum (oocyte). It's a part of the female reproductive system and plays a crucial role in the process of ovulation.

Ovarian follicles start developing in the ovaries during fetal development, but only a small number of them will mature and release an egg during a woman's reproductive years. The maturation process is stimulated by hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

There are different types of ovarian follicles, including primordial, primary, secondary, and tertiary or Graafian follicles. The Graafian follicle is the mature follicle that ruptures during ovulation to release the egg into the fallopian tube, where it may be fertilized by sperm.

It's important to note that abnormal growth or development of ovarian follicles can lead to conditions like polycystic ovary syndrome (PCOS) and ovarian cancer.

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.

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.

Northern blotting is a laboratory technique used in molecular biology to detect and analyze specific RNA molecules (such as mRNA) in a mixture of total RNA extracted from cells or tissues. This technique is called "Northern" blotting because it is analogous to the Southern blotting method, which is used for DNA detection.

The Northern blotting procedure involves several steps:

1. Electrophoresis: The total RNA mixture is first separated based on size by running it through an agarose gel using electrical current. This separates the RNA molecules according to their length, with smaller RNA fragments migrating faster than larger ones.

2. Transfer: After electrophoresis, the RNA bands are denatured (made single-stranded) and transferred from the gel onto a nitrocellulose or nylon membrane using a technique called capillary transfer or vacuum blotting. This step ensures that the order and relative positions of the RNA fragments are preserved on the membrane, similar to how they appear in the gel.

3. Cross-linking: The RNA is then chemically cross-linked to the membrane using UV light or heat treatment, which helps to immobilize the RNA onto the membrane and prevent it from washing off during subsequent steps.

4. Prehybridization: Before adding the labeled probe, the membrane is prehybridized in a solution containing blocking agents (such as salmon sperm DNA or yeast tRNA) to minimize non-specific binding of the probe to the membrane.

5. Hybridization: A labeled nucleic acid probe, specific to the RNA of interest, is added to the prehybridization solution and allowed to hybridize (form base pairs) with its complementary RNA sequence on the membrane. The probe can be either a DNA or an RNA molecule, and it is typically labeled with a radioactive isotope (such as ³²P) or a non-radioactive label (such as digoxigenin).

6. Washing: After hybridization, the membrane is washed to remove unbound probe and reduce background noise. The washing conditions (temperature, salt concentration, and detergent concentration) are optimized based on the stringency required for specific hybridization.

7. Detection: The presence of the labeled probe is then detected using an appropriate method, depending on the type of label used. For radioactive probes, this typically involves exposing the membrane to X-ray film or a phosphorimager screen and analyzing the resulting image. For non-radioactive probes, detection can be performed using colorimetric, chemiluminescent, or fluorescent methods.

8. Data analysis: The intensity of the signal is quantified and compared to controls (such as housekeeping genes) to determine the relative expression level of the RNA of interest. This information can be used for various purposes, such as identifying differentially expressed genes in response to a specific treatment or comparing gene expression levels across different samples or conditions.

"Newborn animals" refers to the very young offspring of animals that have recently been born. In medical terminology, newborns are often referred to as "neonates," and they are classified as such from birth until about 28 days of age. During this time period, newborn animals are particularly vulnerable and require close monitoring and care to ensure their survival and healthy development.

The specific needs of newborn animals can vary widely depending on the species, but generally, they require warmth, nutrition, hydration, and protection from harm. In many cases, newborns are unable to regulate their own body temperature or feed themselves, so they rely heavily on their mothers for care and support.

In medical settings, newborn animals may be examined and treated by veterinarians to ensure that they are healthy and receiving the care they need. This can include providing medical interventions such as feeding tubes, antibiotics, or other treatments as needed to address any health issues that arise. Overall, the care and support of newborn animals is an important aspect of animal medicine and conservation efforts.

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.

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.

Human chromosome pair 12 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each chromosome is made up of DNA tightly coiled around histone proteins, forming a complex structure called a chromatin.

Chromosomes come in pairs, with one chromosome inherited from each parent. In humans, there are 23 pairs of chromosomes, for a total of 46 chromosomes in each cell. Chromosome pair 12 is the 12th pair of autosomal chromosomes, meaning they are not sex chromosomes (X or Y).

Chromosome 12 is a medium-sized chromosome and contains an estimated 130 million base pairs of DNA. It contains around 1,200 genes that provide instructions for making proteins and regulating various cellular processes. Some of the genes located on chromosome 12 include those involved in metabolism, development, and response to environmental stimuli.

Abnormalities in chromosome 12 can lead to genetic disorders, such as partial trisomy 12q, which is characterized by an extra copy of the long arm of chromosome 12, and Jacobsen syndrome, which is caused by a deletion of the distal end of the long arm of chromosome 12.

Sperm motility is the ability of sperm to move actively and effectively through the female reproductive tract towards the egg for fertilization. It is typically measured as the percentage of moving sperm in a sample, and their progressiveness or velocity. Normal human sperm motility is generally defined as forward progression of at least 25 micrometers per second, with at least 50% of sperm showing progressive motility. Reduced sperm motility, also known as asthenozoospermia, can negatively impact fertility and reproductive outcomes.

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.

Salvage therapy, in the context of medical oncology, refers to the use of treatments that are typically considered less desirable or more aggressive, often due to greater side effects or lower efficacy, when standard treatment options have failed. These therapies are used to attempt to salvage a response or delay disease progression in patients with refractory or relapsed cancers.

In other words, salvage therapy is a last-resort treatment approach for patients who have not responded to first-line or subsequent lines of therapy. It may involve the use of different drug combinations, higher doses of chemotherapy, immunotherapy, targeted therapy, or radiation therapy. The goal of salvage therapy is to extend survival, improve quality of life, or achieve disease stabilization in patients with limited treatment options.

A gastrula is a stage in the early development of many animals, including humans, that occurs following fertilization and cleavage of the zygote. During this stage, the embryo undergoes a process called gastrulation, which involves a series of cell movements that reorganize the embryo into three distinct layers: the ectoderm, mesoderm, and endoderm. These germ layers give rise to all the different tissues and organs in the developing organism.

The gastrula is characterized by the presence of a central cavity called the archenteron, which will eventually become the gut or gastrointestinal tract. The opening of the archenteron is called the blastopore, which will give rise to either the mouth or anus, depending on the animal group.

In summary, a gastrula is a developmental stage in which an embryo undergoes gastrulation to form three germ layers and a central cavity, which will eventually develop into various organs and tissues of the body.

A Sertoli cell tumor is a rare type of sex-cord stromal tumor that develops in the testicles or, more rarely, in the ovaries. These tumors arise from the Sertoli cells, which are specialized cells within the testicle that help to nurture and protect the developing sperm cells. In the ovary, Sertoli cell tumors are thought to arise from similar cells that are part of the supporting tissue in the ovary.

Sertoli cell tumors can occur in people of any age but are most commonly found in middle-aged adults. They are usually slow-growing and may not cause any symptoms, especially if they are small. However, larger tumors or those that have spread (metastasized) may cause various symptoms depending on their location and size.

Symptoms of a Sertoli cell tumor can include:

* A painless lump or swelling in the testicle or ovary
* Abdominal pain or discomfort
* Bloating or a feeling of fullness in the abdomen
* Changes in bowel habits or urinary frequency
* Pain during sexual intercourse (in women)
* Hormonal imbalances, such as gynecomastia (breast development) in men or menstrual irregularities in women.

Diagnosis of a Sertoli cell tumor typically involves a combination of imaging tests, such as ultrasound, CT scan, or MRI, and blood tests to check for elevated levels of certain hormones that may be produced by the tumor. A biopsy may also be performed to confirm the diagnosis and determine the tumor's grade and stage.

Treatment for Sertoli cell tumors typically involves surgical removal of the tumor, along with any affected lymph nodes or other tissues. Additional treatments, such as radiation therapy or chemotherapy, may be recommended in cases where the tumor has spread or is at a higher risk of recurrence. Regular follow-up care is also important to monitor for any signs of recurrence or new tumors.

Azoospermia is a medical condition where there is no measurable level of sperm in the semen. This means that during ejaculation, the seminal fluid does not contain any sperm cells. Azoospermia can be caused by various factors including problems with testicular function, obstruction of the genital tract, or hormonal imbalances. It is an important cause of male infertility and may require further medical evaluation and treatment to determine the underlying cause and explore potential options for fertility.

There are two types of azoospermia: obstructive azoospermia and non-obstructive azoospermia. Obstructive azoospermia is caused by blockages or obstructions in the genital tract that prevent sperm from being released into the semen, while non-obstructive azoospermia is due to problems with sperm production in the testicles.

In some cases, men with azoospermia may still be able to father children through assisted reproductive technologies such as intracytoplasmic sperm injection (ICSI), where a single sperm is injected directly into an egg for fertilization. However, this will depend on the underlying cause of the azoospermia and whether or not there are viable sperm available for extraction.

Chorionic Gonadotropin (hCG) is a hormone that is produced during pregnancy. It is produced by the placenta after implantation of the fertilized egg in the uterus. The main function of hCG is to prevent the disintegration of the corpus luteum, which is a temporary endocrine structure that forms in the ovary after ovulation and produces progesterone during early pregnancy. Progesterone is essential for maintaining the lining of the uterus and supporting the pregnancy.

hCG can be detected in the blood or urine as early as 10 days after conception, and its levels continue to rise throughout the first trimester of pregnancy. In addition to its role in maintaining pregnancy, hCG is also used as a clinical marker for pregnancy and to monitor certain medical conditions such as gestational trophoblastic diseases.

The acrosome is a specialized structure located on the anterior part of the sperm head in many species of animals, including humans. It contains enzymes that help the sperm penetrate the outer covering of the egg (zona pellucida) during fertilization. The acrosome reaction is the process by which the acrosome releases its enzymes, allowing the sperm to digest a path through the zona pellucida and reach the egg plasma membrane for fusion and fertilization.

The acrosome is formed during spermatogenesis, the process of sperm production in the testis, from the Golgi apparatus, a cellular organelle involved in protein trafficking and modification. The acrosome contains hydrolytic enzymes such as hyaluronidase, acrosin, and proteases that are activated during the acrosome reaction to facilitate sperm-egg fusion.

Abnormalities in acrosome formation or function can lead to infertility in males.

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.

Cytoplasm is the material within a eukaryotic cell (a cell with a true nucleus) that lies between the nuclear membrane and the cell membrane. It is composed of an aqueous solution called cytosol, in which various organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles are suspended. Cytoplasm also contains a variety of dissolved nutrients, metabolites, ions, and enzymes that are involved in various cellular processes such as metabolism, signaling, and transport. It is where most of the cell's metabolic activities take place, and it plays a crucial role in maintaining the structure and function of the cell.

Zebrafish proteins refer to the diverse range of protein molecules that are produced by the organism Danio rerio, commonly known as the zebrafish. These proteins play crucial roles in various biological processes such as growth, development, reproduction, and response to environmental stimuli. They are involved in cellular functions like enzymatic reactions, signal transduction, structural support, and regulation of gene expression.

Zebrafish is a popular model organism in biomedical research due to its genetic similarity with humans, rapid development, and transparent embryos that allow for easy observation of biological processes. As a result, the study of zebrafish proteins has contributed significantly to our understanding of protein function, structure, and interaction in both zebrafish and human systems.

Some examples of zebrafish proteins include:

* Transcription factors that regulate gene expression during development
* Enzymes involved in metabolic pathways
* Structural proteins that provide support to cells and tissues
* Receptors and signaling molecules that mediate communication between cells
* Heat shock proteins that assist in protein folding and protect against stress

The analysis of zebrafish proteins can be performed using various techniques, including biochemical assays, mass spectrometry, protein crystallography, and computational modeling. These methods help researchers to identify, characterize, and understand the functions of individual proteins and their interactions within complex networks.

3' Untranslated Regions (3' UTRs) are segments of messenger RNA (mRNA) that do not code for proteins. They are located after the last exon, which contains the coding sequence for a protein, and before the poly-A tail in eukaryotic mRNAs.

The 3' UTR plays several important roles in regulating gene expression, including:

1. Stability of mRNA: The 3' UTR contains sequences that can bind to proteins that either stabilize or destabilize the mRNA, thereby controlling its half-life and abundance.
2. Localization of mRNA: Some 3' UTRs contain sequences that direct the localization of the mRNA to specific cellular compartments, such as the synapse in neurons.
3. Translation efficiency: The 3' UTR can also contain regulatory elements that affect the translation efficiency of the mRNA into protein. For example, microRNAs (miRNAs) can bind to complementary sequences in the 3' UTR and inhibit translation or promote degradation of the mRNA.
4. Alternative polyadenylation: The 3' UTR can also contain multiple alternative polyadenylation sites, which can lead to different lengths of the 3' UTR and affect gene expression.

Overall, the 3' UTR plays a critical role in post-transcriptional regulation of gene expression, and mutations or variations in the 3' UTR can contribute to human diseases.

Protein biosynthesis is the process by which cells generate new proteins. It involves two major steps: transcription and translation. Transcription is the process of creating a complementary RNA copy of a sequence of DNA. This RNA copy, or messenger RNA (mRNA), carries the genetic information to the site of protein synthesis, the ribosome. During translation, the mRNA is read by transfer RNA (tRNA) molecules, which bring specific amino acids to the ribosome based on the sequence of nucleotides in the mRNA. The ribosome then links these amino acids together in the correct order to form a polypeptide chain, which may then fold into a functional protein. Protein biosynthesis is essential for the growth and maintenance of all living organisms.

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.

Gestational age is the length of time that has passed since the first day of the last menstrual period (LMP) in pregnant women. It is the standard unit used to estimate the age of a pregnancy and is typically expressed in weeks. This measure is used because the exact date of conception is often not known, but the start of the last menstrual period is usually easier to recall.

It's important to note that since ovulation typically occurs around two weeks after the start of the LMP, gestational age is approximately two weeks longer than fetal age, which is the actual time elapsed since conception. Medical professionals use both gestational and fetal age to track the development and growth of the fetus during pregnancy.

Fertilization is the process by which a sperm cell (spermatozoon) penetrates and fuses with an egg cell (ovum), resulting in the formation of a zygote. This fusion of genetic material from both the male and female gametes initiates the development of a new organism. In human biology, fertilization typically occurs in the fallopian tube after sexual intercourse, when a single sperm out of millions is able to reach and penetrate the egg released from the ovary during ovulation. The successful fusion of these two gametes marks the beginning of pregnancy.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

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.

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.

Cyclic AMP Response Element Modulator (CREM) is a protein that functions as a transcription factor, which binds to specific DNA sequences called cis-acting elements in the promoter region of target genes and regulates their expression. The CREM protein is activated by cyclic AMP (cAMP), a second messenger molecule involved in various cellular signaling pathways.

The CREM protein contains several functional domains, including a DNA-binding domain that recognizes the cAMP response element (CRE) sequence, and a transactivation domain that interacts with other proteins to activate or repress gene transcription. The CREM protein can exist in multiple forms, including activated and repressed isoforms, which are generated by alternative splicing of its pre-mRNA.

The CREM protein plays important roles in various biological processes, such as neuronal development, circadian rhythm regulation, and immune response. Dysregulation of CREM has been implicated in several diseases, including cancer, neurodegenerative disorders, and metabolic disorders.

Argonaute proteins are a family of conserved proteins that play a crucial role in the RNA interference (RNAi) pathway, which is a cellular process that regulates gene expression by post-transcriptional silencing of specific mRNAs. In this pathway, Argonaute proteins function as key components of the RNA-induced silencing complex (RISC), where they bind to small non-coding RNAs such as microRNAs (miRNAs) or small interfering RNAs (siRNAs).

The argonaute protein then uses this small RNA guide to recognize and cleave complementary mRNA targets, leading to their degradation or translational repression. Argonaute proteins contain several domains, including the PIWI domain, which possesses endonuclease activity responsible for the cleavage of target mRNAs.

In addition to their role in RNAi, argonaute proteins have also been implicated in other cellular processes, such as DNA damage repair and transposable element silencing. There are eight argonaute proteins in humans (AGO1-4 and AGO6-8), each with distinct functions and expression patterns. Dysregulation of argonaute proteins has been associated with various diseases, including cancer and neurological disorders.

Carcinoma in situ is a medical term used to describe the earliest stage of cancer, specifically a type of cancer that begins in the epithelial tissue, which is the tissue that lines the outer surfaces of organs and body structures. In this stage, the cancer cells are confined to the layer of cells where they first developed and have not spread beyond that layer into the surrounding tissues or organs.

Carcinoma in situ can occur in various parts of the body, including the skin, cervix, breast, lung, prostate, bladder, and other areas. It is often detected through routine screening tests, such as Pap smears for cervical cancer or mammograms for breast cancer.

While carcinoma in situ is not invasive, it can still be a serious condition because it has the potential to develop into an invasive cancer if left untreated. Treatment options for carcinoma in situ may include surgery, radiation therapy, or other forms of treatment, depending on the location and type of cancer. It is important to consult with a healthcare provider to determine the best course of action for each individual case.

Diethylhexyl Phthalate (DEHP) is a type of phthalate compound that is commonly used as a plasticizer, a substance added to plastics to make them more flexible and durable. DEHP is a colorless, oily liquid with an odor similar to oil or benzene. It is soluble in organic solvents but not in water.

DEHP is used primarily in the production of polyvinyl chloride (PVC) plastics, such as flexible tubing, hoses, and medical devices like blood bags and intravenous (IV) lines. DEHP can leach out of these products over time, particularly when they are subjected to heat or other stressors, leading to potential human exposure.

Exposure to DEHP has been linked to a variety of health effects, including reproductive toxicity, developmental and neurological problems, and an increased risk of cancer. As a result, the use of DEHP in certain applications has been restricted or banned in some countries. The medical community is also moving towards using alternative plasticizers that are considered safer for human health.

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.

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.

Tissue distribution, in the context of pharmacology and toxicology, refers to the way that a drug or xenobiotic (a chemical substance found within an organism that is not naturally produced by or expected to be present within that organism) is distributed throughout the body's tissues after administration. It describes how much of the drug or xenobiotic can be found in various tissues and organs, and is influenced by factors such as blood flow, lipid solubility, protein binding, and the permeability of cell membranes. Understanding tissue distribution is important for predicting the potential effects of a drug or toxin on different parts of the body, and for designing drugs with improved safety and efficacy profiles.

A neoplasm of gonadal tissue refers to an abnormal growth or tumor that develops in the reproductive organs, specifically the ovaries in women and the testes in men. These tumors can be benign (non-cancerous) or malignant (cancerous), and their growth can interfere with the normal function of the gonads.

Gonadal tissue neoplasms can have various causes, including genetic mutations, environmental factors, and hormonal imbalances. The symptoms of these tumors may vary depending on their size, location, and type, but they can include pelvic pain, bloating, abnormal menstruation, or a palpable mass in the affected area.

It is essential to diagnose and treat gonadal tissue neoplasms as early as possible to prevent complications such as infertility, metastasis, or death. Diagnostic procedures may include imaging tests, blood tests, and biopsies, while treatment options may include surgery, radiation therapy, chemotherapy, or hormone therapy.

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.

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.

Inhibins are a group of protein hormones that play a crucial role in regulating the function of the reproductive system, specifically by inhibiting the production of follicle-stimulating hormone (FSH) in the pituitary gland. They are produced and secreted primarily by the granulosa cells in the ovaries of females and Sertoli cells in the testes of males.

Inhibins consist of two subunits, an alpha subunit, and a beta subunit, which can be further divided into two types: inhibin A and inhibin B. Inhibin A is primarily produced by the granulosa cells of developing follicles in the ovary, while inhibin B is mainly produced by the Sertoli cells in the testes.

By regulating FSH production, inhibins help control the development and maturation of ovarian follicles in females and spermatogenesis in males. Abnormal levels of inhibins have been associated with various reproductive disorders, including polycystic ovary syndrome (PCOS) and certain types of cancer.

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.

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.

Androgen-binding protein (ABP) is a protein that binds specifically to androgens, which are hormones such as testosterone that play a role in male sexual development and masculine characteristics. ABP is produced in the Sertoli cells of the testes and helps to regulate the levels of androgens within the testes by storing them and slowly releasing them over time. This is important for maintaining normal sperm production and male reproductive function.

ABP is also found in other tissues, including the prostate gland, where it may play a role in regulating the growth and development of this tissue. Abnormal levels of ABP have been associated with certain medical conditions, such as prostate cancer and infertility.

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 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.

Mosaicism, in the context of genetics and medicine, refers to the presence of two or more cell lines with different genetic compositions in an individual who has developed from a single fertilized egg. This means that some cells have one genetic makeup, while others have a different genetic makeup. This condition can occur due to various reasons such as errors during cell division after fertilization.

Mosaicism can involve chromosomes (where whole or parts of chromosomes are present in some cells but not in others) or it can involve single genes (where a particular gene is present in one form in some cells and a different form in others). The symptoms and severity of mosaicism can vary widely, depending on the type and location of the genetic difference and the proportion of cells that are affected. Some individuals with mosaicism may not experience any noticeable effects, while others may have significant health problems.

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.

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.

Human Y chromosomes are one of the two sex-determining chromosomes in humans (the other being the X chromosome). They are found in the 23rd pair of human chromosomes and are significantly smaller than the X chromosome.

The Y chromosome is passed down from father to son through the paternal line, and it plays a crucial role in male sex determination. The SRY gene (sex-determining region Y) on the Y chromosome initiates the development of male sexual characteristics during embryonic development.

In addition to the SRY gene, the human Y chromosome contains several other genes that are essential for sperm production and male fertility. However, the Y chromosome has a much lower gene density compared to other chromosomes, with only about 80 protein-coding genes, making it one of the most gene-poor chromosomes in the human genome.

Because of its small size and low gene density, the Y chromosome is particularly susceptible to genetic mutations and deletions, which can lead to various genetic disorders and male infertility. Nonetheless, the Y chromosome remains a critical component of human genetics and evolution, providing valuable insights into sex determination, inheritance patterns, and human diversity.

The "sperm tail" is also known as the flagellum, which is a whip-like structure that enables the sperm to move or swim through fluid. The human sperm tail is made up of nine microtubule doublets and a central pair of microtubules, which are surrounded by a mitochondrial sheath that provides energy for its movement. This complex structure allows the sperm to navigate through the female reproductive tract in order to reach and fertilize an egg.

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.

Busulfan is a chemotherapy medication used to treat various types of cancer, including chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML). It is an alkylating agent that works by damaging the DNA of cancer cells, which prevents them from dividing and growing.

The medical definition of Busulfan is:

A white crystalline powder used in chemotherapy to treat various types of cancer. Busulfan works by alkylating and cross-linking DNA, which inhibits DNA replication and transcription, leading to cell cycle arrest and apoptosis (programmed cell death) in rapidly dividing cells, including cancer cells. It is administered orally or intravenously and is often used in combination with other chemotherapy agents. Common side effects include nausea, vomiting, diarrhea, and bone marrow suppression, which can lead to anemia, neutropenia, thrombocytopenia, and increased susceptibility to infection. Long-term use of busulfan has been associated with pulmonary fibrosis, infertility, and an increased risk of secondary malignancies.

Protamines are small, arginine-rich proteins that are found in the sperm cells of many organisms. They play a crucial role in the process of sperm maturation, also known as spermiogenesis. During this process, the DNA in the sperm cell is tightly packed and compacted by the protamines, which helps to protect the genetic material during its journey to fertilize an egg.

Protamines are typically composed of around 50-100 amino acids and have a high proportion of positively charged arginine residues, which allow them to interact strongly with the negatively charged DNA molecule. This interaction results in the formation of highly condensed chromatin structures that are resistant to enzymatic digestion and other forms of damage.

In addition to their role in sperm maturation, protamines have also been studied for their potential use in drug delivery and gene therapy applications. Their ability to bind strongly to DNA makes them attractive candidates for delivering drugs or genetic material directly to the nucleus of a cell. However, more research is needed to fully understand the potential benefits and risks associated with these applications.

RNA helicases are a class of enzymes that are capable of unwinding RNA secondary structures using the energy derived from ATP hydrolysis. They play crucial roles in various cellular processes involving RNA, such as transcription, splicing, translation, ribosome biogenesis, and RNA degradation. RNA helicases can be divided into several superfamilies based on their sequence and structural similarities, with the two largest being superfamily 1 (SF1) and superfamily 2 (SF2). These enzymes typically contain conserved motifs that are involved in ATP binding and hydrolysis, as well as RNA binding. By unwinding RNA structures, RNA helicases facilitate the access of other proteins to their target RNAs, thereby enabling the coordinated regulation of RNA metabolism.

The sacrococcygeal region is the lower part of the back where the spine ends, specifically referring to the area where the sacrum (a triangular bone at the base of the spine formed by the fusion of several vertebrae) meets the coccyx (also known as the tailbone). This region is located at the very bottom of the spine and is susceptible to injury or trauma due to its position and role in supporting the body's weight. It is also a common site for birth defects, particularly in newborns.

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.

Tumor markers are substances that can be found in the body and their presence can indicate the presence of certain types of cancer or other conditions. Biological tumor markers refer to those substances that are produced by cancer cells or by other cells in response to cancer or certain benign (non-cancerous) conditions. These markers can be found in various bodily fluids such as blood, urine, or tissue samples.

Examples of biological tumor markers include:

1. Proteins: Some tumor markers are proteins that are produced by cancer cells or by other cells in response to the presence of cancer. For example, prostate-specific antigen (PSA) is a protein produced by normal prostate cells and in higher amounts by prostate cancer cells.
2. Genetic material: Tumor markers can also include genetic material such as DNA, RNA, or microRNA that are shed by cancer cells into bodily fluids. For example, circulating tumor DNA (ctDNA) is genetic material from cancer cells that can be found in the bloodstream.
3. Metabolites: Tumor markers can also include metabolic products produced by cancer cells or by other cells in response to cancer. For example, lactate dehydrogenase (LDH) is an enzyme that is released into the bloodstream when cancer cells break down glucose for energy.

It's important to note that tumor markers are not specific to cancer and can be elevated in non-cancerous conditions as well. Therefore, they should not be used alone to diagnose cancer but rather as a tool in conjunction with other diagnostic tests and clinical evaluations.

Hexanone is not a medical term, but a chemical one. It refers to a class of organic compounds known as ketones, which contain a carbonyl group (a functional group consisting of a carbon atom double-bonded to an oxygen atom: C=O) and six carbon atoms (hence "hexa-").

In the context of medical toxicology, hexanone exposure can occur through inhalation, skin contact, or ingestion. Hexanones are found in some industrial solvents, cleaning agents, and glues. Exposure to high levels of hexanones can cause symptoms such as dizziness, headache, nausea, vomiting, and in severe cases, neurological damage.

However, it's important to note that specific medical conditions or diseases are not associated with 'hexanones'. If you have any concerns about exposure to this chemical or any other potential toxins, please consult a healthcare professional for advice.

Mammals are a group of warm-blooded vertebrates constituting the class Mammalia, characterized by the presence of mammary glands (which produce milk to feed their young), hair or fur, three middle ear bones, and a neocortex region in their brain. They are found in a diverse range of habitats and come in various sizes, from tiny shrews to large whales. Examples of mammals include humans, apes, monkeys, dogs, cats, bats, mice, raccoons, seals, dolphins, horses, and elephants.

The urogenital system is a part of the human body that includes the urinary and genital systems. The urinary system consists of the kidneys, ureters, bladder, and urethra, which work together to produce, store, and eliminate urine. On the other hand, the genital system, also known as the reproductive system, is responsible for the production, development, and reproduction of offspring. In males, this includes the testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands, and penis. In females, it includes the ovaries, fallopian tubes, uterus, vagina, mammary glands, and external genitalia.

The urogenital system is closely related anatomically and functionally. For example, in males, the urethra serves as a shared conduit for both urine and semen, while in females, the urethra and vagina are separate but adjacent structures. Additionally, some organs, such as the prostate gland in males and the Skene's glands in females, have functions that overlap between the urinary and genital systems.

Disorders of the urogenital system can affect both the urinary and reproductive functions, leading to a range of symptoms such as pain, discomfort, infection, and difficulty with urination or sexual activity. Proper care and maintenance of the urogenital system are essential for overall health and well-being.

I'm sorry for any confusion, but "Insect Proteins" is not a recognized medical term. However, I can provide some information about insect protein from a nutritional and food science perspective.

Insect proteins refer to the proteins that are obtained from insects. Insects are a rich source of protein, and their protein content varies by species. For example, mealworms and crickets have been found to contain approximately 47-63% and 60-72% protein by dry weight, respectively.

In recent years, insect proteins have gained attention as a potential sustainable source of nutrition due to their high protein content, low environmental impact, and the ability to convert feed into protein more efficiently compared to traditional livestock. Insect proteins can be used in various applications such as food and feed additives, nutritional supplements, and even cosmetics.

However, it's important to note that the use of insect proteins in human food is not widely accepted in many Western countries due to cultural and regulatory barriers. Nonetheless, research and development efforts continue to explore the potential benefits and applications of insect proteins in the global food system.

A pinealoma is a rare type of brain tumor that originates in the pineal gland, a small endocrine gland located in the center of the brain. The pineal gland is responsible for producing melatonin, a hormone that helps regulate sleep-wake cycles. Pinealomas can be benign or malignant, with malignant pinealomas being more aggressive and likely to spread to other parts of the body.

Pinealomas are typically classified as either pineocytomas or pineoblastomas, depending on their appearance under a microscope. Pineocytomas are slow-growing and less aggressive, while pineoblastomas are fast-growing and more likely to spread. Symptoms of pinealomas can include headaches, nausea, vomiting, vision problems, and hormonal imbalances.

Treatment for pinealomas typically involves surgery to remove as much of the tumor as possible, followed by radiation therapy and/or chemotherapy to kill any remaining cancer cells. The prognosis for pinealomas varies depending on the type and stage of the tumor, as well as the patient's age and overall health.

Histochemistry is the branch of pathology that deals with the microscopic localization of cellular or tissue components using specific chemical reactions. It involves the application of chemical techniques to identify and locate specific biomolecules within tissues, cells, and subcellular structures. This is achieved through the use of various staining methods that react with specific antigens or enzymes in the sample, allowing for their visualization under a microscope. Histochemistry is widely used in diagnostic pathology to identify different types of tissues, cells, and structures, as well as in research to study cellular and molecular processes in health and disease.

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.

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.

Aromatase is a enzyme that belongs to the cytochrome P450 superfamily, and it is responsible for converting androgens into estrogens through a process called aromatization. This enzyme plays a crucial role in the steroid hormone biosynthesis pathway, particularly in females where it is primarily expressed in adipose tissue, ovaries, brain, and breast tissue.

Aromatase inhibitors are used as a treatment for estrogen receptor-positive breast cancer in postmenopausal women, as they work by blocking the activity of aromatase and reducing the levels of circulating estrogens in the body.

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.

A larva is a distinct stage in the life cycle of various insects, mites, and other arthropods during which they undergo significant metamorphosis before becoming adults. In a medical context, larvae are known for their role in certain parasitic infections. Specifically, some helminth (parasitic worm) species use larval forms to infect human hosts. These invasions may lead to conditions such as cutaneous larva migrans, visceral larva migrans, or gnathostomiasis, depending on the specific parasite involved and the location of the infection within the body.

The larval stage is characterized by its markedly different morphology and behavior compared to the adult form. Larvae often have a distinct appearance, featuring unsegmented bodies, simple sense organs, and undeveloped digestive systems. They are typically adapted for a specific mode of life, such as free-living or parasitic existence, and rely on external sources of nutrition for their development.

In the context of helminth infections, larvae may be transmitted to humans through various routes, including ingestion of contaminated food or water, direct skin contact with infective stages, or transmission via an intermediate host (such as a vector). Once inside the human body, these parasitic larvae can cause tissue damage and provoke immune responses, leading to the clinical manifestations of disease.

It is essential to distinguish between the medical definition of 'larva' and its broader usage in biology and zoology. In those fields, 'larva' refers to any juvenile form that undergoes metamorphosis before reaching adulthood, regardless of whether it is parasitic or not.

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.

Sperm maturation is the process by which spermatids, immature sperm cells produced in meiosis, transform into fully developed spermatozoa capable of fertilization. This complex process occurs in the seminiferous tubules of the testes and includes several stages:

1. **Golfi formation:** The first step involves the spermatids reorganizing their cytoplasm and forming a cap-like structure called the acrosome, which contains enzymes that help the sperm penetrate the egg's outer layers during fertilization.
2. **Flagellum development:** The spermatid also develops a tail (flagellum), enabling it to move independently. This is achieved through the assembly of microtubules and other associated proteins.
3. **Nuclear condensation and elongation:** The sperm's DNA undergoes significant compaction, making the nucleus smaller and more compact. Concurrently, the nucleus elongates and aligns with the flagellum.
4. **Mitochondrial positioning:** Mitochondria, which provide energy for sperm motility, migrate to the midpiece of the sperm, close to the base of the flagellum.
5. **Chromatin packaging:** Histones, proteins that help package DNA in non-sperm cells, are replaced by transition proteins and then protamines, which further compact and protect the sperm's DNA.
6. **Sperm release (spermiation):** The mature sperm is finally released from the supporting Sertoli cells into the lumen of the seminiferous tubule, where it mixes with fluid secreted by the testicular tissue to form seminal plasma.

This entire process takes approximately 64 days in humans.

DNA fragmentation is the breaking of DNA strands into smaller pieces. This process can occur naturally during apoptosis, or programmed cell death, where the DNA is broken down and packaged into apoptotic bodies to be safely eliminated from the body. However, excessive or abnormal DNA fragmentation can also occur due to various factors such as oxidative stress, exposure to genotoxic agents, or certain medical conditions. This can lead to genetic instability, cellular dysfunction, and increased risk of diseases such as cancer. In the context of reproductive medicine, high levels of DNA fragmentation in sperm cells have been linked to male infertility and poor assisted reproductive technology outcomes.

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.

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.

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.

Gonadotropins are hormones that stimulate the gonads (sex glands) to produce sex steroids and gametes (sex cells). In humans, there are two main types of gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are produced and released by the anterior pituitary gland.

FSH plays a crucial role in the development and maturation of ovarian follicles in females and sperm production in males. LH triggers ovulation in females, causing the release of a mature egg from the ovary, and stimulates testosterone production in males.

Gonadotropins are often used in medical treatments to stimulate the gonads, such as in infertility therapies where FSH and LH are administered to induce ovulation or increase sperm production.

Chromosome mapping, also known as physical mapping, is the process of determining the location and order of specific genes or genetic markers on a chromosome. This is typically done by using various laboratory techniques to identify landmarks along the chromosome, such as restriction enzyme cutting sites or patterns of DNA sequence repeats. The resulting map provides important information about the organization and structure of the genome, and can be used for a variety of purposes, including identifying the location of genes associated with genetic diseases, studying evolutionary relationships between organisms, and developing genetic markers for use in breeding or forensic applications.

Chorionic Gonadotropin, beta Subunit, Human (β-hCG) is a protein that is produced by the placenta during pregnancy. It is a component of human chorionic gonadotropin (hCG), which is a hormone that is composed of two subunits: alpha and beta. The β-hCG subunit is specific to hCG and is not found in other hormones, making it a useful marker for pregnancy and certain medical conditions.

During early pregnancy, the levels of β-hCG increase rapidly and can be detected in the blood and urine. This has led to the development of pregnancy tests that detect the presence of β-hCG to confirm pregnancy. In addition to its role in pregnancy, β-hCG is also used as a tumor marker for certain types of cancer, such as germ cell tumors and choriocarcinoma.

Elevated levels of β-hCG may indicate the presence of a molar pregnancy, a condition in which a fertilized egg implants in the uterus but does not develop properly. In some cases, a molar pregnancy can become cancerous and require treatment. Therefore, monitoring β-hCG levels during pregnancy is important for detecting any potential complications.

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.

Cypriniformes is an order of freshwater fish that includes carps, minnows, and loaches. These fish are characterized by the presence of a single pair of barbels near their mouths and the absence of teeth on their jaws. They are found primarily in North America, Europe, and Asia. Some well-known examples of Cypriniformes include the common carp, goldfish, and zebrafish. These fish are often used as model organisms in scientific research due to their relatively small size, ease of breeding, and genetic similarity to humans.

Genes are the fundamental units of heredity in living organisms. They are made up of DNA (deoxyribonucleic acid) and are located on chromosomes. Genes carry the instructions for the development and function of an organism, including its physical and behavioral traits.

Helminths, also known as parasitic worms, are a type of parasite that can infect various organs and tissues in humans and animals. They have complex life cycles that involve multiple hosts and stages of development. Examples of helminths include roundworms, tapeworms, and flukes.

In the context of genetics, genes from helminths are studied to understand their role in the biology and evolution of these parasites, as well as to identify potential targets for the development of new drugs or vaccines to control or eliminate helminth infections. This involves studying the genetic makeup of helminths, including their DNA, RNA, and proteins, and how they interact with their hosts and the environment.

Combined modality therapy (CMT) is a medical treatment approach that utilizes more than one method or type of therapy simultaneously or in close succession, with the goal of enhancing the overall effectiveness of the treatment. In the context of cancer care, CMT often refers to the combination of two or more primary treatment modalities, such as surgery, radiation therapy, and systemic therapies (chemotherapy, immunotherapy, targeted therapy, etc.).

The rationale behind using combined modality therapy is that each treatment method can target cancer cells in different ways, potentially increasing the likelihood of eliminating all cancer cells and reducing the risk of recurrence. The specific combination and sequence of treatments will depend on various factors, including the type and stage of cancer, patient's overall health, and individual preferences.

For example, a common CMT approach for locally advanced rectal cancer may involve preoperative (neoadjuvant) chemoradiation therapy, followed by surgery to remove the tumor, and then postoperative (adjuvant) chemotherapy. This combined approach allows for the reduction of the tumor size before surgery, increases the likelihood of complete tumor removal, and targets any remaining microscopic cancer cells with systemic chemotherapy.

It is essential to consult with a multidisciplinary team of healthcare professionals to determine the most appropriate CMT plan for each individual patient, considering both the potential benefits and risks associated with each treatment method.

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.

A germ-line mutation is a genetic change that occurs in the egg or sperm cells (gametes), and thus can be passed down from parents to their offspring. These mutations are present throughout the entire body of the offspring, as they are incorporated into the DNA of every cell during embryonic development.

Germ-line mutations differ from somatic mutations, which occur in other cells of the body that are not involved in reproduction. While somatic mutations can contribute to the development of cancer and other diseases within an individual, they are not passed down to future generations.

It's important to note that germ-line mutations can have significant implications for medical genetics and inherited diseases. For example, if a parent has a germ-line mutation in a gene associated with a particular disease, their offspring may have an increased risk of developing that disease as well.

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.

"Male genitalia" refers to the reproductive and sexual organs that are typically present in male individuals. These structures include:

1. Testes: A pair of oval-shaped glands located in the scrotum that produce sperm and testosterone.
2. Epididymis: A long, coiled tube that lies on the surface of each testicle where sperm matures and is stored.
3. Vas deferens: A pair of muscular tubes that transport sperm from the epididymis to the urethra.
4. Seminal vesicles: Glands that produce a fluid that mixes with sperm to create semen.
5. Prostate gland: A small gland that surrounds the urethra and produces a fluid that also mixes with sperm to create semen.
6. Bulbourethral glands (Cowper's glands): Two pea-sized glands that produce a lubricating fluid that is released into the urethra during sexual arousal.
7. Urethra: A tube that runs through the penis and carries urine from the bladder out of the body, as well as semen during ejaculation.
8. Penis: The external organ that serves as both a reproductive and excretory organ, expelling both semen and urine.

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.

Fetal development is the process in which a fertilized egg grows and develops into a fetus, which is a developing human being from the end of the eighth week after conception until birth. This complex process involves many different stages, including:

1. Fertilization: The union of a sperm and an egg to form a zygote.
2. Implantation: The movement of the zygote into the lining of the uterus, where it will begin to grow and develop.
3. Formation of the embryo: The development of the basic structures of the body, including the neural tube (which becomes the brain and spinal cord), heart, gastrointestinal tract, and sensory organs.
4. Differentiation of tissues and organs: The process by which different cells and tissues become specialized to perform specific functions.
5. Growth and maturation: The continued growth and development of the fetus, including the formation of bones, muscles, and other tissues.

Fetal development is a complex and highly regulated process that involves the interaction of genetic and environmental factors. Proper nutrition, prenatal care, and avoidance of harmful substances such as tobacco, alcohol, and drugs are important for ensuring healthy fetal development.

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.

RNA (Ribonucleic acid) is a single-stranded molecule that plays a crucial role in the process of gene expression. It acts as a messenger carrying genetic information copied from DNA to the ribosomes, where proteins are synthesized. RNA is also involved in catalyzing chemical reactions and regulating gene expression.

Helminths, on the other hand, refer to parasitic worms that infect humans and animals. They belong to various phyla, including Nematoda (roundworms), Platyhelminthes (flatworms), and Acanthocephala (spiny-headed worms). Helminth infections can cause a range of diseases and conditions, such as intestinal inflammation, anemia, stunted growth, and cognitive impairment.

There is no medical definition for "RNA, Helminth" since RNA is a type of molecule found in all living organisms, including helminths. However, researchers have studied the genetic material of various helminth species to better understand their biology, evolution, and pathogenesis. This includes sequencing and analyzing the RNA transcriptome of these parasites, which can provide insights into their gene expression patterns and help identify potential drug targets for developing new treatments.

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.

I'm sorry for any confusion, but "Marsupialia" is not a medical term. It is a taxonomic category in biology, specifically an order that includes mammals known as marsupials. These are mammals that carry their young in a pouch after birth. Examples of marsupials include kangaroos, koalas, and opossums. If you have any medical questions or terms you would like defined, I'd be happy to help!

Protein isoforms are different forms or variants of a protein that are produced from a single gene through the process of alternative splicing, where different exons (or parts of exons) are included in the mature mRNA molecule. This results in the production of multiple, slightly different proteins that share a common core structure but have distinct sequences and functions. Protein isoforms can also arise from genetic variations such as single nucleotide polymorphisms or mutations that alter the protein-coding sequence of a gene. These differences in protein sequence can affect the stability, localization, activity, or interaction partners of the protein isoform, leading to functional diversity and specialization within cells and organisms.

Sexual development is a multidimensional process that includes physical, cognitive, emotional, and social aspects. It refers to the changes and growth that occur in an individual from infancy to adulthood related to sexuality, reproduction, and gender identity. This process involves the maturation of primary and secondary sex characteristics, the development of sexual attraction and desire, and the acquisition of knowledge about sexual health and relationships.

Physical aspects of sexual development include the maturation of reproductive organs, hormonal changes, and the development of secondary sexual characteristics such as breast development in females and facial hair growth in males. Cognitive aspects involve the development of sexual knowledge, attitudes, and values. Emotional aspects refer to the emergence of sexual feelings, desires, and fantasies, as well as the ability to form intimate relationships. Social aspects include the development of gender roles and identities, communication skills related to sexuality, and the ability to navigate social norms and expectations around sexual behavior.

Sexual development is a complex and ongoing process that is influenced by various factors such as genetics, hormones, environment, culture, and personal experiences. It is important to note that sexual development varies widely among individuals, and there is no one "normal" or "correct" way for it to unfold.

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.

Multiple primary neoplasms refer to the occurrence of more than one primary malignant tumor in an individual, where each tumor is unrelated to the other and originates from separate cells or organs. This differs from metastatic cancer, where a single malignancy spreads to multiple sites in the body. Multiple primary neoplasms can be synchronous (occurring at the same time) or metachronous (occurring at different times). The risk of developing multiple primary neoplasms increases with age and is associated with certain genetic predispositions, environmental factors, and lifestyle choices such as smoking and alcohol consumption.

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 "mixed tumor, malignant" is a rare and aggressive type of cancer that contains two or more different types of malignant tissue. It is also known as a "malignant mixed Mullerian tumor" (MMMT) or "carcinosarcoma." This type of tumor most commonly arises in the female reproductive organs, such as the uterus or ovaries, but can also occur in other parts of the body.

The malignant mixed Mullerian tumor is composed of both epithelial and mesenchymal components, which are two different types of tissue. The epithelial component is made up of cancerous glandular or squamous cells, while the mesenchymal component consists of cancerous connective tissue, such as muscle, fat, or bone.

Mixed tumors, malignant can be aggressive and have a high risk of recurrence and metastasis. Treatment typically involves surgical removal of the tumor, followed by radiation therapy and/or chemotherapy to kill any remaining cancer cells. The prognosis for mixed tumors, malignant varies depending on several factors, including the size and location of the tumor, the stage of the disease at diagnosis, and the patient's overall health.

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.

Organ culture techniques refer to the methods used to maintain or grow intact organs or pieces of organs under controlled conditions in vitro, while preserving their structural and functional characteristics. These techniques are widely used in biomedical research to study organ physiology, pathophysiology, drug development, and toxicity testing.

Organ culture can be performed using a variety of methods, including:

1. Static organ culture: In this method, the organs or tissue pieces are placed on a porous support in a culture dish and maintained in a nutrient-rich medium. The medium is replaced periodically to ensure adequate nutrition and removal of waste products.
2. Perfusion organ culture: This method involves perfusing the organ with nutrient-rich media, allowing for better distribution of nutrients and oxygen throughout the tissue. This technique is particularly useful for studying larger organs such as the liver or kidney.
3. Microfluidic organ culture: In this approach, microfluidic devices are used to create a controlled microenvironment for organ cultures. These devices allow for precise control over the flow of nutrients and waste products, as well as the application of mechanical forces.

Organ culture techniques can be used to study various aspects of organ function, including metabolism, secretion, and response to drugs or toxins. Additionally, these methods can be used to generate three-dimensional tissue models that better recapitulate the structure and function of intact organs compared to traditional two-dimensional cell cultures.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

Primordial germ cells, germ cells that still have to reach the gonads (also known as PGCs, precursor germ cells or gonocytes) ... A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells ... The somatic cells on the path of germ cells provide them attractive, repulsive, and survival signals. But germ cells also send ... This means that they can differentiate in any cell type in the body and thus germ cells. Specification of primordial germ cells ...
Male germ-line stem cells divide asymmetrically to give one stem cell and a spermatogonia cell (unspecialised male germ cell) ... Germ cell nest breakdown involves the degeneration of many germ cell nuclei and the invasion of pre-granulosa cells into the ... In the germ cell nest, one germ cell matures into an oocyte whereas others act as 'nurse cells', transferring their contents ... In mammals, germ cells form syncytia of hundreds of germ cells interconnected by intercellular bridges. As they share a common ...
... (GCT) is a neoplasm derived from germ cells. Germ-cell tumors can be cancerous or benign. Germ cells normally ... Childhood Extracranial Germ Cell Tumors Extragonadal Germ Cell Tumors Ovarian Germ Cell Tumors Packer RJ, Cohen BH, Cooney K, ... The nongerminomatous or nonseminomatous germ-cell tumors (NGGCT, NSGCT) include all other germ-cell tumors, pure and mixed. The ... International Germ Cell Cancer Collaborative Group (February 1997). "International Germ Cell Consensus Classification: a ...
GCNH is expressed mainly in the germ cells of gonads and is involved in the regulation of embryogenesis and germ cell ... The germ cell nuclear factor (GCNF), also known as RTR (retinoid receptor-related testis-associated receptor) or NR6A1 (nuclear ... Lan ZJ, Chung AC, Xu X, DeMayo FJ, Cooney AJ (Dec 2002). "The embryonic function of germ cell nuclear factor is dependent on ... Kapelle M, Krätzschmar J, Husemann M, Schleuning WD (May 1997). "cDNA cloning of two closely related forms of human germ cell ...
Primordial germ cell (PGC) migration is the process of distribution of primordial germ cells throughout the embryo during ... Down-regulation will result in reduced cell-cell adhesion which allows the germ cells to separate and begin the migration ... Coffman, Clark R. (May 2003). "Cell migration and programmed cell death of Drosophila germ cells". Annals of the New York ... the germ cells move towards the somatic gonadal precursor cells and associate with them. These two associated cell types then ...
Ovarian Germ Cell Tumor Extragonadal Germ Cell Tumor Cancer.net: Germ Cell Tumor include extracranial germ cell tumor ... An extracranial germ cell tumor (EGCT) occurs in the abnormal growth of germ cells in the gonads (testes or ovaries) and the ... "Mixed Germ Cell Tumor - American Urological Association". www.auanet.org. Retrieved 2019-05-29. "Extracranial Germ Cell Tumor ... Shaikh F, Hale J (2013-08-03), "Clinical Treatment of Extracranial Pediatric Germ Cell Tumors", Pediatric Germ Cell Tumors, ...
... (OGCTs) are heterogeneous tumors that are derived from the primitive germ cells of the embryonic gonad ... OGCT is caused mainly due to the formation of malignant cancer cells in the primordial germ cells of the ovary. The exact ... In order to heal the tissue and replace the damage, the cells undergoes cell division. Each time the cell divides, there is a ... Wang Y, Yang JX, Yu M, Cao DY, Shen K (2018). "Malignant mixed ovarian germ cell tumor composed of immature teratoma, yolk sac ...
... s are tumors that derive from germ cell rest remnants in the mediastinum. Germ cell tumors most ... They are much less common than germ cell tumors arising in the testes, and account for only 1 to 5% of all germ cell neoplasms ... "Mediastinal Germ Cell Tumors". Semin Respir Crit Care Med. 18 (4): 383-392. doi:10.1055/s-2007-1009353. "Mediastinal Germ Cell ... Others hypothesize a widespread distribution of germ cells to multiple sites during normal embryogenesis, with these cells ...
... (GCNIS) represents the precursor lesion for many types of testicular germ cell tumors. The term ... Not all germ cell tumors (GCTs) arise from intratubular germ cell neoplasia. The following testicular GCTs do not arise from ... Chemotherapy used for metastatic germ cell tumours may also eradicate GCNIS. Carcinoma in situ Germ cell tumor ITGCN. H&E stain ... Almost all invasive germ cell tumours of the testis in adults Fifty percent of patients with GCNIS developed invasive germ cell ...
... cell Pneumocyte Type I cell Type II cell Club cell Goblet cell Pulmonary neuroendocrine cell Enteroendocrine cell G cell Delta ... Hepatic stellate cell Cholecystocyte Centroacinar cell Pancreatic stellate cell alpha cell beta cell delta cell PP cell (F cell ... Podocyte Kidney proximal tubule brush border cell Sertoli cell Leydig cell Granulosa cell Peg cell Germ cells (which migrate ... cell Parafollicular cell Parathyroid gland Parathyroid chief cell Oxyphil cell Urothelial cell Germ layer List of distinct cell ...
Germ cell Histogenesis Neurulation List of human cell types derived from the germ layers Gilbert, Scott F (2003). "The ... A germ layer is a primary layer of cells that forms during embryonic development. The three germ layers in vertebrates are ... Through cell signaling cascades and interactions with the ectodermal and endodermal cells, the mesodermal cells begin the ... "Pluripotency Factors in Embryonic Stem Cells Regulate Differentiation into Germ Layers". Cell. 145 (6): 875-889. doi:10.1016/j. ...
Germ cells). ... Through circulation it is transported to the follicle cells ... Frontiers in Cell and Developmental Biology. 8: 593613. doi:10.3389/fcell.2020.593613. PMC 7901893. PMID 33634094. Hurd H (2003 ...
Germ Cells. Cold Spring Harbor Laboratory Press, ISBN 9781936113514 Sassone-Corsi, Paolo; Christen, Yves.,(2012), Epigenetics, ... Cell. 134 (2): 329-340. doi:10.1016/j.cell.2008.07.002. ISSN 0092-8674. PMC 3526943. PMID 18662547. Cheung, Peter; Allis, C. ... Cell. 125 (3): 497-508. doi:10.1016/j.cell.2006.03.033. ISSN 0092-8674. PMID 16678094. S2CID 5968161. Nakahata, Yasukazu; ... As such, AP-1 has a significant role in the cell cycle. Circadian biology research In 2006, Sassoni-Corsi illuminated the role ...
September 2004). "European consensus on diagnosis and treatment of germ cell cancer: a report of the European Germ Cell Cancer ... Germ cell cancer". Archived from the original on 2012-04-26. W. Albrecht; et al. (2004). "Testicular tumor markers: Corner- ... stones in the management of malignant germ cell tumors" (PDF). J Lab Med. 28 (2): 109-115. doi:10.1515/labmed.2004.018. S2CID ... Cell Biol. 116 (3): 799-807. doi:10.1083/jcb.116.3.799. PMC 2289307. PMID 1730777. Micanovic R, Gerber LD, Berger J, Kodukula K ...
Michael Ashburner (May 27, 2013). "Nebenkern (Gene Ontology term)". (Germ cells, Drosophila). ...
There are three general types of cells: germ cells, somatic cells, and stem cells. Germ cells lead to the production of gametes ... stem cell are undifferentiated cells which can develop into a specialized cell and are the earliest type of cell in a cell ... and fungi whose germ cells are derived from prior somatic cells as opposed to stem cells. The Weismann barrier is essential to ... as in unicellular ones the purposes of somatic and germ cells are consolidated in one cell. All organisms with germ-soma ...
Jamnongjit, Michelle; Hammes, Stephen R. (August 2005). "Oocyte maturation: The coming of age of a germ cell". Seminars in ... Cell Biology and Translational Medicine, Volume 8: Stem Cells in Regenerative Medicine, Cham: Springer International Publishing ... Oocytes are immature egg cells that develop to maturity within a follicle in the ovary. Oocyte abnormalities can occur due to ... The germinal vesicle breaks down and spindles assemble as homologous chromosomes align the cell's equator for the first meiotic ...
... whereas nongerminomatous germ-cell tumors display a variety of differentiation. Like other germ-cell tumors, germinomas can ... Microscopic examination typically reveals uniform cells that resemble primordial germ cells. Typically, the stroma contains ... As with other germ-cell tumors (GCTs) occurring outside the gonads, the most common location of intracranial germinoma is on or ... Nongerminomatous germ-cell tumors may be associated with increased markers such as alpha-fetoprotein with yolk sac tumors, as ...
oskar plays role in recruiting other germ line genes to the germ plasm for PGC (primordial germ cell) specification. oskar mRNA ... meaning that the P granules play a role in the cell cycle of germ cells. It is still unclear exactly how the nuclear granules ... These ribonucleoprotein granules are found in every species' germ line cells. Although they are mobile, they typically localize ... September 2018). "Drosophila primordial germ cells". eLife. 7. doi:10.7554/eLife.37949. PMC 6191285. PMID 30260314. Wang JT, ...
... s are the most common type of germ cell tumors (both benign and malignant) diagnosed in neonates, ... Rescorla FJ (March 1999). "Pediatric germ cell tumors". Semin Surg Oncol. 16 (2): 144-58. doi:10.1002/(SICI)1098-2388(199903)16 ...
In 2003 Extavour did a study at Cambridge University on the mechanisms of germ cell formation that showed animal germ cells ... She is known for demonstrating that germ cells engage in cell to cell competition before becoming a gamete, which indicates ... Derivation of male germ cells from induced pluripotent stem cells by inducers: A review "NSF Award Search: Award#0955517 - RCN ... An embryonic cell receives chemical signals from neighboring cells that activate (or repress) the genes that allow for germ- ...
"Germ Cell" of interdisciplinary neuroscience". Clinical Neuropathology. 27 (6): 439-443. doi:10.5414/NPP27439. ISSN 0722-5091. ... A great deal of study on sensory organs and the function of nerve cells was conducted by British physiologist Keith Lucas and ... Langley J.N. (1905). "On the reaction of cells and of nerve-endings to certain poisons, chiefly as regards the reaction of ... Langley, J. N. (1898-07-26). "On the Union of Cranial Autonomic (Visceral) Fibres with the Nerve Cells of the Superior Cervical ...
Blastocyst or parthenogenetic split blastocyst obtained by somatic cell nuclear transfer technology; or Germ cells voluntarily ... Stem cell laws and policy in Iran Dennis, Carina (2002). "China: Stem cells rise in the East". Nature. 419 (6905): 334-6. doi: ... Chinese law, Stem cells, Biotechnology law, Stem cell research, Medical law, Science and technology in China). ... Stem cell research in China thus is unlikely ever to be prone to the intense Christian moral values in the West, especially so ...
Meiosis is the general process in eukaryotic organisms by which germ cells are formed, and it is likely an adaptation for ... "Ovarian Germ Cell Tumors Treatment". National Cancer Institute. 1980-01-01. Retrieved 2017-12-01. Seiden, Michael (2015). " ... "Chocolate cysts from ovarian follicles".{{cite web}}: CS1 maint: multiple names: authors list (link) "Treatment for Germ Cell ... Follicular cells are flat epithelial cells that originate from surface epithelium covering the ovary. They are surrounded by ...
... germ cells and embryonal cells. Teratomas of embryonic origin are congenital; teratomas of germ cell origin may or may not be ... not germ cell) malignancy such as leukemia, carcinoma, or sarcoma. A teratoma may contain elements of other germ cell tumors, ... They are a type of germ cell tumor (a tumor that begins in the cells that give rise to sperm or eggs). They are divided into ... Teratomas derived from germ cells occur in the testicle and ovaries. Teratomas derived from embryonic cells usually occur on ...
... tumors are not considered a subtype of seminoma and unlike other germ cell tumours do not arise from intratubular germ cell ... About half of germ cell tumors of the testicles are seminomas. Treatment usually requires removal of one testicle. However, ... This is about 5 to 10 years older than men with other germ cell tumors of the testes. In most cases, they produce masses that ... A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a ...
PARP1 is over-expressed in tyrosine kinase-activated leukemias, in neuroblastoma, in testicular and other germ cell tumors, and ... The more receptors a cell has that are tuned to the message, the more the cell will respond to it. Receptors are created, or ... This process is illustrated by the insulin receptor sites on target cells, e.g. liver cells, in a person with type 2 diabetes. ... Over time, this self-induced loss of target cell receptors for insulin reduces the target cell's sensitivity to the elevated ...
... a rachis is the central cell-free core or axis of the gonadal arm of both adult males and hermaphrodites where the germ cells ... Germ Cell Development in C. elegans. Springer. p. 11. ISBN 978-1-4614-4015-4. Retrieved 6 August 2013. (Articles with short ...
For instance, at least 36 DNA repair enzymes, when mutationally defective in germ line cells, cause increased risk of cancer ( ... In asthma PARP1 facilitates recruitment and function of immune cells, including CD4+ T-cells, eosinophils, and dendritic cells ... July 2013). "PARP expression in germ cell tumours". Journal of Clinical Pathology. 66 (7): 607-12. doi:10.1136/jclinpath-2012- ... Initially, overactivation of the enzyme was linked to apoptotic cell death but later, PARP1-mediated cell death turned out to ...
PARP1 is over-expressed in tyrosine kinase-activated leukemias, in neuroblastoma, in testicular and other germ cell tumors, and ... Gagnon KT, Li L, Chu Y, Janowski BA, Corey DR (2014). "RNAi factors are present and active in human cell nuclei". Cell Rep. 6 ( ... "PARP expression in germ cell tumours". J. Clin. Pathol. 66 (7): 607-612. doi:10.1136/jclinpath-2012-201088. PMID 23486608. ... of non-small-cell lung cancers; promoter hypermetylation of ATM occurs in 47% of non-small-cell lung cancers; promoter ...
Primordial germ cells, germ cells that still have to reach the gonads (also known as PGCs, precursor germ cells or gonocytes) ... A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells ... The somatic cells on the path of germ cells provide them attractive, repulsive, and survival signals. But germ cells also send ... This means that they can differentiate in any cell type in the body and thus germ cells. Specification of primordial germ cells ...
Germ cell tumors happen when reproductive cells in an unborn baby dont develop as they should. ... What Are Germ Cells?. Germ cells are the reproductive cells in an unborn baby. In boys, the cells make sperm and in girls, they ... What Are Germ Cell Tumors?. Germ cells that grow in an unusual way can become a tumor . Often, these tumors form in the ovaries ... What Are the Types of Germ Cell Tumors?. Like tumors that form in other places in the body, germ cell tumors can be benign (not ...
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Surgical staging is the first step in the management of ovarian germ cell cancer. Staging includes peritoneal cytology, ... encoded search term (Ovarian Germ Cell Tumor Treatment Protocols) and Ovarian Germ Cell Tumor Treatment Protocols What to Read ... Ovarian Germ Cell Tumor Treatment Protocols Updated: Mar 30, 2022 * Author: Elizabeth L Jewell, MD, MHSc; Chief Editor: Yukio ... Management of ovarian germ cell tumors. J Clin Oncol. 2007 Jul 10. 25(20):2938-43. [QxMD MEDLINE Link]. ...
... is a malignant neoplasm derived from the primordial germ cell. Although it accounts for approximately 1% of all malignancies in ... Germ-cell testicular cancer (GCTC) is a malignant neoplasm derived from the primordial germ cell. Although it accounts for ... Referral Center for Treatment of Germ Cell Tumors and Extragonadal Germ Cell Tumors of the Ministry of Health of the Republic ... Treatment of germ cell testicular cancer Acta Clin Croat. 2020 Sep;59(3):496-504. doi: 10.20471/acc.2020.59.03.14. ...
Germ cell tumors happen when reproductive cells in an unborn baby dont develop as they should. ... What Are Germ Cells?. Germ cells are the reproductive cells in an unborn baby. In boys, the cells make sperm and in girls, they ... What Are Germ Cell Tumors?. Germ cells that grow in an unusual way can become a tumor . Often, these tumors form in the ovaries ... What Are the Types of Germ Cell Tumors?. Like tumors that form in other places in the body, germ cell tumors can be benign (not ...
A robust method to induce primordial germ cells from human pluripotent stem cells has been developed, highlighting the ... Human primordial germ cells in a dish. *Kim Baumann Nature Reviews Molecular Cell Biology volume 16, page 68 (2015)Cite this ... As PGC-like cells represent the earliest stage of the human germ cell lineage, they provide a tool for further understanding ... These analyses revealed that induced PGC-like cells shared expression profiles (including core germ cell genes) with early PGCs ...
... of all ovarian cancers are germ cell tumors.. For most types and stages of germ cell cancers. Most types and stages of germ ... Treating benign germ cell tumors. Women with benign (non-cancerous) germ cell tumors such as mature teratomas (dermoid cysts) ... Treating malignant germ cell tumors. As with epithelial ovarian cancers, it is a good idea to consult with a gynecologic ... Germ cell cancers can raise blood levels of the tumor markers human chorionic gonadotropin (HCG), alpha-fetoprotein (AFP), and/ ...
Posted in Gold Ribbon Hero , Tagged ACCO, childhood cancer, germ cell, germ cell brain tumor, Germinoma brain cancer, Gold ... Tag Archives: germ cell Meet Grace - a sweet and spirited 9 year old and one of our Ambassadors for Childhood Cancer Awareness ... Grace was diagnosed with Germinoma brain cancer, a germ cell brain tumor, on May 2, 2018. Her aggressive treatment began on May ...
Germ Cell Tumor - Childhood - Risk Factors up Germ Cell Tumor - Childhood - Diagnosis › ... Germ Cell Tumor - Childhood: Symptoms and Signs. Approved by the Cancer.Net Editorial Board, 05/2021 ... If a germ cell tumor is diagnosed, relieving symptoms remains an important part of your childs medical care and treatment. ... Sometimes, children with a germ cell tumor do not have any of the signs and symptoms described below. Or, the cause of a ...
... the tumor cells in the lung are actually cancerous germ cells. The disease is metastatic extragonadal germ cell tumor, not lung ... Stages of Extragonadal Germ Cell Tumors. Key Points. *After an extragonadal germ cell tumor has been diagnosed, tests are done ... Extragonadal Germ Cell Tumors Treatment General Information About Extragonadal Germ Cell Tumors. Go to Health Professional ... Extragonadal germ cell tumors can be benign (noncancer) or malignant (cancer). Benign extragonadal germ cell tumors are called ...
Read more about our childhood germ cell tumor treatment methods here. ... Childrens Cancer Hospital is committed to providing the most advanced treatments for childhood germ cell tumors with the least ... Childhood Germ Cell Tumors Treatment. Our childhood germ cell tumor treatments. Treatment for germ cell tumors depends upon the ... Malignant germ cell tumors can spread to other parts of the body before they are diagnosed. Chemotherapy travels all through ...
In humans, germ cells produce specialized cells needed for reproduction: sperm cells in boys and egg cells in girls. Germ cell ... germ cell comes from the term geminate, which means giving life. ... Physician reviewed information for families about germ cell tumors in children, including the latest information, news, and ... In humans, germ cells produce specialized cells needed for reproduction: sperm cells in boys and egg cells in girls. Germ cell ...
Next Generation Cell Free Protein Expression Kit (Wheat Germ) (CFPS700) are for research use only.. ... Please note that adding wheat germ extract more than 10 µL for 110 µL solution could decrease the yeild of translation product. ... Protein synthesis using cell-free protein synthesis reagent kit consists of three stages: preparation of transcription template ... In detection other than immunostaining, Wheat Germ components are also detected, so loading large amounts of samples is not ...
Focused Germ Cell Tumors with stained slides of pathology. ... Germ Cell Tumors. Home "> Neuropath "> Non-Glial Tumors "> Germ ... Germ Cell Tumors. High Quality Pathology Images of Neuropath: Non-Glial Tumors of Germ Cell Tumors. ...
span,,b,Background:,/b, Testicular germ cell tumor (TGCT) incidence has increased over the last 40 years in the United States. ... Background: Testicular germ cell tumor (TGCT) incidence has increased over the last 40 years in the United States. In contrast ... Neonatal Hormone Concentrations and Risk of Testicular Germ Cell Tumors (TGCT) Cancer Epidemiol Biomarkers Prev. 2018 Apr;27(4 ...
... germ cell tumors form in germ cells, which are cells that develop into sperm or ova (eggs). Germ cell tumors can be either ... Mixed germ cell tumors. A mixed germ cell tumor has two types of germ cells in it. ... Intracranial Germ Cell Tumor Information about pediatric CNS Germ Cell Tumors treatment, clinical trials, and research from ... Germ cell brain tumors usually form in the center of the brain, near the pineal gland. The pineal gland is a tiny organ in the ...
cell surface Video of zebrafish embryo development from a 2-cell egg to fish larva. Images were collected using confocal ...
Syndromes Associated with Mediastinal Nonseminomatour Germ Cell Tumors ... Increasing evidence indicates that many individuals who develop germ cell tumors have underlying germ cell defects. Many ... treated for extragonadal germ cell tumors have a markedly increased risk of developing a subsequent testicular germ cell tumor ... germ cell defect contributes not only to defective spermatogenesis but also to the development of extragonadal germ cell tumors ...
At Dana-Farber/Boston Childrens, we treat pediatric germ cell tumors of the brain, including germinomas and non-germinomatous ... A germ cell tumor of the brain arises from developing cells that form in the embryo. ... About Childhood Germ Cell Tumor of the Brain. * Germ cell tumors that develop in the brain or spinal cord are also called CNS ( ... We classify germ cell tumors of the brain into two main types:. *Germinomas: These are pure germ cell tumors. They respond well ...
If your doctor failed to diagnose a germ cell tumor, you might qualify for compensation. Find out how to file for medical ... Germ Cell Tumor Misdiagnosis Lawyer. If your doctor failed to diagnose a germ cell tumor, you might qualify for compensation. ... Was My Doctor Negligent in Misdiagnosing My Germ Cell Tumor?. Germ cell tumors most commonly occur in reproductive organs, such ... How Can I Talk to a Lawyer About My Germ Cell Tumor Misdiagnosis Claim?. If you or a loved one suffered harm because of a germ ...
A germ cell is a type of cell that forms as a fetus develops. These cells later become sperm in the testicles or eggs in the ... This summary is about germ cell tumors that form in parts of the body that are... ... Childhood extracranial germ cell tumors form from germ cells in parts of the body other than the brain. ... Mixed germ cell tumors. Mixed germ cell tumors are made up of at least two types of malignant germ cell tumor. They can form in ...
Treatment with FWGE (1-2%) significantly decreased the level of intracellular ROS compared to LPS-treated cells. ... against LPS-induced inflammation and oxidative stress in IPEC-J2 porcine intestinal epithelial cells was studied. Enterocytes ... the protective effect of a fermented wheat germ extract (FWGE) ... Cell Line and Culture Conditions. The IPEC-J2 cell line was ... S. N. Lee, H. Park, and K. E. Lee, "Cytotoxic activities of fermented wheat germ extract on human gastric carcinoma cells by ...
urologic care for testicular germ cell tumors in pediatric and adolescent patients. ... Current urologic care for testicular germ cell tumors in pediatric and adolescent patients July 20, 2015 Testicular germ cell ... Since the discovery of platinum-based chemotherapy, testicular germ cell tumors are a highly curable disease. However, ... adolescent histology is mostly mixed nonseminomatous germ cell tumor.. Surgical excision of the primary tumor is the crux of ...
Literature suggests that the only known risk factor for extragonadal germ cell tumors (EGCTs) is Klinefelter syndrome (47XXY), ... which is associated with mediastinal nonseminomatous germ cell tumors. ... Extragonadal germinal cell syndromes are rare tumors that predominantly affect young males. ... Extra-gonadal germ cell tumors (EGGCTs) represent 5-10% of all germ cell tumor (GCTs) with an incidence around 1/ in 1,000,000 ...
... on murine germ cells, and more specifically on oocytes and their precursors. ... In utero germ-cell exposure to bisphenols: a role for oxidative damage in oocyte aneuploidy. ©Marie-Justine Guerquin (iRCM) ... You are here : Home , News , In utero germ-cell exposure to bisphenols : a role for oxidative damage in oocyte aneuploidy ... on murine germ cells, and more specifically on oocytes and their precursors. Their results show that oxidative damage caused by ...
... supports primordial germ cell (PGC) growth, survival, migration and reprogramming to pluripotent embryonic germ cells (EGCs). ... supports primordial germ cell (PGC) growth, survival, migration and reprogramming to pluripotent embryonic germ cells (EGCs). ... Primordial germ cells and gastrointestinal stromal tumors respond distinctly to a cKit overactivating allele.. Return to Grants ... These results demonstrate a cell-context-dependent response to the cKit(V558Δ) mutation. We propose that AKT overload ...
Investigation and development of optimum cell culture media used for germ cell lines both in the laboratory and for use on the ... The primary mission was to undertake innovative research on stem cell biology, germ cell development, and animal transgenesis. ... Director, Center for Animal Transgenesis and Germ Cell Research. Elizabeth Woodward, PhD. Clinical Assistant Professor, ... Center for Animal Transgenesis & Germ Cell Research Scientists at the School of Veterinary Medicine performed pioneering ...
Wheat germ cell-free expression system as a pathway to improve protein yield and solubility for the SSGCID pipeline ... The wheat germ cell-free expression system combines the advantages of cell-free and eukaryotic systems and is well suited for ... Cell-free expression. Cell-free solubility. Anaplasma marginale. ACR67103.1. Full length. Major surface protein 2 variant 9H1. ... Wheat germ cell-free expression system as a pathway to improve protein yield and solubility for the SSGCID pipeline. ...
  • Teratomas are the most common type of germ cell tumor to develop in extragonadal (not in the ovary or testes) areas. (kidshealth.org)
  • Boys with undescended testicles (testes that stay up inside the pelvis) also seem to be at a higher risk for a germ cell tumor. (kidshealth.org)
  • Early on, a child with a benign or malignant germ cell tumor might have few symptoms or none at all. (kidshealth.org)
  • Higher levels can suggest a germ cell tumor. (kidshealth.org)
  • Children with benign germ cell tumors will have surgery to remove the tumor. (kidshealth.org)
  • Women with benign (non-cancerous) germ cell tumors such as mature teratomas (dermoid cysts) are cured by removing the part of the ovary that has the tumor (ovarian cystectomy) or by removing the entire ovary. (cancer.org)
  • Germ cell cancers can raise blood levels of the tumor markers human chorionic gonadotropin (HCG), alpha-fetoprotein (AFP), and/or lactate dehydrogenase (LDH). (cancer.org)
  • Grace was diagnosed with Germinoma brain cancer, a germ cell brain tumor, on May 2, 2018. (acco.org)
  • A child with an extracranial, extragonadal germ cell tumor may experience the following symptoms and signs. (cancer.net)
  • Sometimes, children with a germ cell tumor do not have any of the signs and symptoms described below. (cancer.net)
  • If a germ cell tumor is diagnosed, relieving symptoms remains an important part of your child's medical care and treatment. (cancer.net)
  • A procedure in which a sample of blood is examined to measure the amounts of certain substances released into the blood by organs, tissues , or tumor cells in the body. (vicc.org)
  • A PET scan is a procedure to find malignant tumor cells in the body. (vicc.org)
  • Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do. (vicc.org)
  • Treatment for germ cell tumors depends upon the child's age and overall health, the types of tissues in the tumor, the tumor's location, the child's tolerance for specific types of procedures and the overall prognosis. (mdanderson.org)
  • Germ cell cancer is a rare tumor that affects children, teens, and adults. (curesearch.org)
  • Malignant germ cell tumors include several types of cancer, such as immature teratoma, yolk sac tumor, embryonal carcinoma, and choriocarcinoma. (curesearch.org)
  • Benign germ cell tumors include certain kinds of teratomas, a type of tumor that may contain several different types of tissue. (curesearch.org)
  • Testicular germ cell tumor (TGCT) incidence has increased over the last 40 years in the United States. (nih.gov)
  • Texas Children's Cancer Center's Brain Tumor Program and the Neuro-oncology Team treat patients with Intracranial Germ Cell Tumors. (texaschildrens.org)
  • A mixed germ cell tumor has two types of germ cells in it. (texaschildrens.org)
  • The average age of patients with Klinefelter syndrome who develop extragonadal germ cell tumors is approximately 18 years, 10 years younger than the median age of those developing this tumor in the absence of Klinefelter syndrome. (health.am)
  • therefore, the association with mediastinal germ cell tumor seems specific. (health.am)
  • In addition, patients who are successfully treated for extragonadal germ cell tumors have a markedly increased risk of developing a subsequent testicular germ cell tumor. (health.am)
  • In a series of 635 patients with extragonadal germ cell tumors, 17 patients developed hematologic malignancies at a median of 6 months after the extragonadal germ cell tumor was diagnosed. (health.am)
  • Recent evidence indicates that the hematologic neoplasms in this setting are not treatment related, but rather arise from clones of malignant lymphoblasts or myeloblasts contained within the mediastinal germ cell tumor. (health.am)
  • More importantly, several patients have had an identical chromosomal abnormality (an isochromosome of the short arm of chromosome 12) in the neoplastic cells from the mediastinal germ cell tumor and the hematologic neoplasm, providing strong evidence for a common origin. (health.am)
  • Within the Childhood Brain Tumor Center , our specialists have extensive expertise in treating all types of brain tumors, including germ cell tumors. (dana-farber.org)
  • Successfully treating your child's germ cell tumor depends on identifying the tumor type and location. (dana-farber.org)
  • Depending on the germ cell tumor type, we may recommend further surgery to remove as much of the tumor as possible. (dana-farber.org)
  • If your doctor failed to diagnose a germ cell tumor, you might qualify for compensation. (medicalmalpracticehelp.com)
  • The longer a germ cell tumor progresses before treatment begins, the more painful, invasive, and expensive it is to cure it. (medicalmalpracticehelp.com)
  • A germ cell tumor misdiagnosis lawyer might be able to help you file for malpractice . (medicalmalpracticehelp.com)
  • Was My Doctor Negligent in Misdiagnosing My Germ Cell Tumor? (medicalmalpracticehelp.com)
  • Depending on where the tumor originates, it could present symptoms associated with other, less-serious conditions, causing doctors to overlook germ cell cancer as a cause. (medicalmalpracticehelp.com)
  • however, adolescent histology is mostly mixed nonseminomatous germ cell tumor. (urotoday.com)
  • However, the smaller the residual mass, the lower the chance that it harbors viable tumor cells. (medscape.com)
  • Some retroperitoneal extragonadal germ cell tumors may represent metastases from a testicular cancer , with subsequent spontaneous necrosis of the primary tumor. (medscape.com)
  • 76 patients were confirmed germinoma, 29 mixed germ cell tumor, 4 teratoma, 9 malignant teratoma, 6 endodermal sinus tumor, 20 choriocarcinoma and 1 embryonal carcinoma. (researchsquare.com)
  • Classification of central nervous system germ cell tumors according to the World Health Organization divides them into germinoma and non-germinoma germ cell tumors(NGGCTs), with 6 different types of the latter, which includes teratoma, embryonal carcinoma, endodermal sinus tumor (yolk sac tumor), chorionic epithelioma (also called choriocarcinoma) and mixed germ cell tumors(GCTs) 7 (including above components sometimes teratoma and germinoma as well). (researchsquare.com)
  • For recent decades, it has been recognized that malignant tumor cells potentially induce local and systemic immunosuppression 9 . (researchsquare.com)
  • Germ cell component was pure teratoma in 27 cases, teratoma mixed with other components in 17, pure seminoma in 2, intratubular GCT in 1 and hepatoid yolk sac tumor in 1. (biomedcentral.com)
  • Treatment alternatives for germ cell tumors might also additionally consist of surgical procedure to cast off the tumor, chemotherapy with tablets that kill most cancers cells and radiation remedy with effective strength beams. (satyughealthcare.com)
  • Changes with inside the genes of a germ cell can reason it to develop out of control, which ends up in a tumor. (satyughealthcare.com)
  • Embryonal carcinoma has most cancers cells that normally blend with every other kind of germ cell tumor. (satyughealthcare.com)
  • The following factors have been associated with a higher risk for children to develop a gonadal germ cell tumor. (shebaonline.org)
  • Cryptorchidism: An undescended testicle raises the risk for a boy to develop a testicular germ cell tumor. (shebaonline.org)
  • Turner syndrome: This genetic condition, which occurs in girls, is linked to a higher chance of developing a benign germ cell tumor that can eventually become cancerous. (shebaonline.org)
  • Intersex conditions: Androgen insensitivity, which involves resistance to male hormones called androgens, increases the risk of developing a gonadal germ cell tumor. (shebaonline.org)
  • Klinefelter syndrome: This genetic condition that occurs in males is linked to a higher risk of a germ cell tumor in the chest. (shebaonline.org)
  • What are the Symptoms a Germ Cell Tumor? (shebaonline.org)
  • The symptoms of a germ cell tumor depend largely on where the growth develops. (shebaonline.org)
  • When it is a gonadal germ cell tumor, there may also be early development of public hair, breast enlargement or vaginal bleeding at a very young age. (shebaonline.org)
  • A form of testicular germ cell tumor occurring in the third decade of life with a usually painless unilateral mass in the scrotum or in some cases with gynaecomastia and/or back and flack pain. (globalgenes.org)
  • Newly diagnosed with Non-seminomatous germ cell tumor of testis? (globalgenes.org)
  • Objective: To assess prenatal air toxics exposure and risk for childhood germ cell tumors (GCTs) by histological subtype (yolk sac tumor and teratoma). (cdc.gov)
  • As with epithelial ovarian cancers, it is a good idea to consult with a gynecologic oncologist for treating malignant germ cell tumors, especially because these are so uncommon. (cancer.org)
  • In general, all women with malignant germ cell tumors will have the same staging surgery that is done for epithelial ovarian cancer. (cancer.org)
  • Malignant germ cell tumors can spread to other parts of the body before they are diagnosed. (mdanderson.org)
  • Kurman RJ, Norris HJ: Malignant germ cell tumors of the ovary. (kaiserpermanente.org)
  • These are proven to be highly informative to investigate the underlying mechanisms related to both normal and malignant germ cell development. (maximabutterfly.com)
  • Weissbach L (1995) Organ preserving surgery of malignant germ cell tumors. (medscape.com)
  • Prenatal exposure to air toxics and malignant germ cell tumors in young children. (cdc.gov)
  • There are several sub-types of non-germinomatous germ cell tumors, including teratomas, choriocarcinomas, endodermal sinus tumors (yolk sac tumors), embryonal carcinomas, and mixed tumors. (dana-farber.org)
  • For example, embryonal carcinoma cells could to blend with a teratoma and make it most cancers. (satyughealthcare.com)
  • Neoplasms, Germ Cell and Embryonal" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (sdsu.edu)
  • This graph shows the total number of publications written about "Neoplasms, Germ Cell and Embryonal" by people in this website by year, and whether "Neoplasms, Germ Cell and Embryonal" was a major or minor topic of these publications. (sdsu.edu)
  • Below are the most recent publications written about "Neoplasms, Germ Cell and Embryonal" by people in Profiles. (sdsu.edu)
  • What Are the Types of Germ Cell Tumors? (kidshealth.org)
  • There are two types of germ cell tumors: malignant (life-threatening) or benign (not life-threatening). (curesearch.org)
  • The two main types of germ cell tumors of the brain are germinomas and non-germinomatous tumors. (dana-farber.org)
  • Germ-cell testicular cancer (GCTC) is a malignant neoplasm derived from the primordial germ cell. (nih.gov)
  • KitL, via its receptor cKit, supports primordial germ cell (PGC) growth, survival, migration and reprogramming to pluripotent embryonic germ cells (EGCs). (ca.gov)
  • In its race to advance assisted reproduction and stem cell associated technologies to save the northern white rhinoceros from extinction, the BioRescue consortium announces a major breakthrough: the creation of primordial germ cell-like cells (PGCLSs) from induced pluripotent stem cells of the northern white rhino Nabire. (izw-berlin.de)
  • The scientists relied on knowledge from the mouse model: In 2016, Katsuhiko Hayashi and his team managed to create primordial germ cell-like cells and finally germ cells from mice that were fertilised in the lab and resulted in healthy offspring being born. (izw-berlin.de)
  • Prof Kathleen Molyneaux - Department of Genetics, Case Western Reserve University for providing mouse primordial germ cell migration movies. (edu.au)
  • Cite this page: Hill, M.A. (2023, December 11) Embryology Primordial Germ Cell Migration Movie . (edu.au)
  • Hematologic Neoplasia A unique association between mediastinal nonseminomatous germ cell tumors and a variety of hematologic neoplasms is now well described. (health.am)
  • All hematologic neoplasms developed in the 287 patients with mediastinal nonseminomatous germ cell tumors, for a 2% incidence in this group. (health.am)
  • However, the specific association of leukemias and other hematologic neoplasms with mediastinal nonseminomatous germ cell tumors, rather than with all germ cell tumors, remains unexplained. (health.am)
  • Neoplasms composed of primordial GERM CELLS of embryonic GONADS or of elements of the germ layers of the EMBRYO, MAMMALIAN. (sdsu.edu)
  • Benign extragonadal germ cell tumors are called benign teratomas . (vicc.org)
  • Most ovarian germ cell tumors are benign mature teratomas (dermoid cysts). (cigna.com)
  • Surgical staging is the first step in the management of ovarian germ cell cancer . (medscape.com)
  • Most women with germ cell cancer will need to be treated with combination chemo for at least 3 cycles. (cancer.org)
  • Extragonadal germ cell tumors can be benign (noncancer) or malignant ( cancer ). (vicc.org)
  • The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. (vicc.org)
  • Children's Cancer Hospital offers the most up-to-date and advanced chemotherapy options for childhood germ cell tumors. (mdanderson.org)
  • Radiation therapy (also called radiotherapy) uses high-energy beams to destroy cancer cells. (mdanderson.org)
  • New radiation therapy techniques and remarkable skill allow Children's Cancer Hospital doctors to target tumors more precisely, delivering the maximum amount of radiation with the least damage to healthy cells. (mdanderson.org)
  • Children's Cancer Hospital is committed to providing the most advanced treatments for childhood germ cell tumors with the least impact on your child's body, today and in the future. (mdanderson.org)
  • Children's Cancer Hospital offers a range of clinical trials for childhood germ cell tumors. (mdanderson.org)
  • Childhood germ cell tumors are treated in our Children's Cancer Hospital and our Proton Therapy Center. (mdanderson.org)
  • Information about pediatric CNS Germ Cell Tumors treatment, clinical trials, and research from Texas Children's Cancer Center. (texaschildrens.org)
  • A fermented wheat germ extract (FWGE) is a natural nontoxic substance which is already used in the human medicine as a supportive therapy in cancer patients under radiotherapy and chemotherapy [ 5 ]. (hindawi.com)
  • found that FWGE can promote apoptosis in different types of cancer cell lines such as SNU-5, MKN-45, SNU-620, SNU-1, and SNU-16. (hindawi.com)
  • Combined treatment of FWGE and 5-fluorouracil or dacarbazine resulted in a synergistic effect in the HCR-25 human cancer cell line and B16 murine melanoma cell line [ 6 ]. (hindawi.com)
  • Maternal smoking in pregnancy may increase the risk of testicular germ cell cancer (TGCC) in offspring, but current evidence remains inconclusive. (lu.se)
  • Cancer develops due to the growth of abnormal cells in areas of a person's body. (medicalnewstoday.com)
  • Germ cell tumors are a rare form of ovarian cancer. (medicalnewstoday.com)
  • Dysgerminomas are a rare form of germ cell cancer that generally affects females in their teens or 20s. (medicalnewstoday.com)
  • Germ cell tumors are considered rare, accounting for approximately 4% of all cases of pediatric cancer. (shebaonline.org)
  • Once cancer is found, the first step is to determine the type of cancer cell by examining it under a microscope. (medlineplus.gov)
  • Chemotherapy uses medicines to kill cancer cells. (medlineplus.gov)
  • 2003) Histology and clinical outcomes in patients with bilateral testicular germ cell tumors: the Memorial Sloan Kettering Cancer Center experience 1950 to 2001. (medscape.com)
  • 1995) Bilateral synchronous testicular germ cell cancer. (medscape.com)
  • 2005) Risk-adapted management for patients with clinical stage I seminoma: the second Spanish Germ Cell Cancer Cooperative Group Study. (medscape.com)
  • 2006) Management of bilateral testicular germ cell tumours-experience of the German Testicular Cancer Study Group (GTCSC) [abstract]. (medscape.com)
  • these abnormal chromosomes are often observed in cancer cells. (cdc.gov)
  • Although it is normally inactive in most other cells in the body, telomerase is activated in cancer cells, making them "immortal. (cdc.gov)
  • Primordial germ cells, germ cells that still have to reach the gonads (also known as PGCs, precursor germ cells or gonocytes) divide repeatedly on their migratory route through the gut and into the developing gonads. (wikipedia.org)
  • Primordial germ cells (PGCs) are the precursors of sperm and eggs. (nature.com)
  • In mammals, PGCs are induced during grastrulation from epiblast cells in response to several cues. (nature.com)
  • Much of what is known about mammalian germ cell specification is based on studies in mice, in which PGCs are specified at embryonic day 6.5 (E6.5) by bone morphogenetic protein 4 (BMP4) and other signals. (nature.com)
  • To characterize these induced PGC-like cells and confirm their germ cell identity, the authors performed gene expression profile analyses, comparing the induced cells to human PGCs from 7-week-old male embryos and to a human seminoma originating from the germline in vivo . (nature.com)
  • These analyses revealed that induced PGC-like cells shared expression profiles (including core germ cell genes) with early PGCs and seminomas. (nature.com)
  • According to their most recent paper published in the journal "Science Advances", the team has now successfully cultivated primordial germ cells (PGCs) - the precursors of eggs and sperm - from embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). (izw-berlin.de)
  • In sexually reproducing organisms such as humans, rhinos or mice, primordial germ cells (PGCs) are embryonic precursors of sperm and eggs that pass on genetic and epigenetic information from one generation to the next. (izw-berlin.de)
  • Because PGCs are the founder population for gametes, this accomplishment paves a way to produce functional gametes from induced pluripotent stem cells from northern white rhinos which will contribute to the effort to rewind their extinction. (izw-berlin.de)
  • Primordial Germ Cells (PGCs) labelled in green are initially distributed near the hindgut region of the embryo. (edu.au)
  • Depending on the species, DAZL is expressed in primordial germ cells (PGCs) and/or pre-meiotic and meiotic germ cells of both sexes. (ijbs.com)
  • The end-products of the germ cell cycle are the egg or sperm. (wikipedia.org)
  • In boys , the cells make sperm and in girls , they make eggs. (kidshealth.org)
  • Extragonadal germ cell tumors form from developing sperm or egg cells that travel from the gonads to other parts of the body. (vicc.org)
  • When cells that are meant to form sperm in the testicles or eggs in the ovaries travel to other parts of the body, they may grow into extragonadal germ cell tumors . (vicc.org)
  • In humans, germ cells produce specialized cells needed for reproduction: sperm cells in boys and egg cells in girls. (curesearch.org)
  • Childhood Central Nervous System (CNS) germ cell tumors form in germ cells, which are cells that develop into sperm or ova (eggs). (texaschildrens.org)
  • These cells later become sperm in the testicles or eggs in the ovaries. (cigna.com)
  • An improved understanding of the basic processes governing germ cell and embryo development and of the biology of gametes (sperm and oocytes) and embryonic stem cells will enable us to improve reproductive efficiency, generate animal models of human and animal disease and help provide the knowledge base for regenerative medicine, as well as toward the treatment of infertility. (upenn.edu)
  • Crucial to embryo production is the availability of oocytes (egg cells) and sperm. (izw-berlin.de)
  • Germ Cell Tumours (GCT) develop from cells that produce eggs or sperm so usually affect the ovaries or testes. (supershoes.org.uk)
  • As a baby develops during pregnancy, the cells producing eggs or sperm move to the ovaries or testes. (supershoes.org.uk)
  • In many species, the germ cells, precursors of sperm and egg, migrate during embryogenesis. (woofahs.com)
  • These cancers grow from germ cells, the cells that make sperm. (medlineplus.gov)
  • Germ cells (eggs and sperm) and stem cells contain an enzyme, telomerase, that restores telomere length. (cdc.gov)
  • Extragonadal germ cell tumors form in parts of the body other than the gonads (testicles or ovaries). (vicc.org)
  • Germ cell tumors most commonly appear in the testes for boys and the ovaries for girls. (curesearch.org)
  • Most germ cell tumors appear in the ovaries ( ovarian tumors ) or testes ( testicular tumors ), but they can also get "trapped" in the brain during the fetal period. (dana-farber.org)
  • Gonadal germ cell tumors form in the gonads (testicles and ovaries). (cigna.com)
  • [ 1 , 2 ] In extragonadal germ cell tumors, no evidence of a primary malignancy is present in either the testes or ovaries by radiologic imaging or physical examination. (medscape.com)
  • Secondary antibodies used were either FITC, Cy3, or Cy5 conjugated to species-specific secondary antibodies (Jackson ImmunoResearch Laboratories, Inc.). For nuclear staining, fixed ovaries were incubated for 15 min with Draq5 (Cell Signaling Technology). (ucsd.edu)
  • Most germ cell tumors arise with inside the testicles or the ovaries. (satyughealthcare.com)
  • Germ cell tumors that arise in locations apart from the testicles and ovaries (extragonadal germ cell tumors) are very rare. (satyughealthcare.com)
  • They're the maximum not unusualplace germ cell tumors determined withinside the ovaries. (satyughealthcare.com)
  • Germ cell tumors in children are growths that typically develop from reproductive cells in the ovaries in girls and in the testes in boys. (shebaonline.org)
  • Most types and stages of germ cell cancers of the ovary are treated the same way, with surgery and chemotherapy (chemo). (cancer.org)
  • Since the discovery of platinum-based chemotherapy, testicular germ cell tumors are a highly curable disease. (urotoday.com)
  • Cisplatin-based chemotherapy for ovarian germ cell malignancies: the Australian experience. (kaiserpermanente.org)
  • The association of Klinefelter syndrome and mediastinal nonseminomatous germ cell tumors is now well recognized. (health.am)
  • In addition to hematologic neoplasia, several cases of idiopathic thrombocytopenia in association with mediastinal nonseminomatous germ cell tumors have been reported. (health.am)
  • The only known risk factor for extragonadal germ cell tumors is Klinefelter syndrome (47XXY), which is associated with mediastinal nonseminomatous germ cell tumors, which are characterized by their location on the midline from the pineal gland to the coccyx. (medscape.com)
  • Literature suggests that the only known risk factor for extragonadal germ cell tumors (EGCTs) is Klinefelter syndrome (47XXY), which is associated with mediastinal nonseminomatous germ cell tumors. (medscape.com)
  • Hematologic disorders associated with primary mediastinal nonseminomatous germ cell tumors. (medscape.com)
  • Nonseminomatous germ cell tumors are most cancers and are determined withinside the brain. (satyughealthcare.com)
  • What Are the Signs & Symptoms of Germ Cell Tumors? (kidshealth.org)
  • The following are the maximum not unusualplace signs and symptoms of germ cell tumors. (satyughealthcare.com)
  • More than 900 children and adolescents are diagnosed with germ cell tumors in the U.S. each year, comprising about 5% of all childhood cancers . (curesearch.org)
  • The overall prognosis for children diagnosed with germ cell tumors has approximately a 93% survival rate, and that rate rises to 99% with regard to gonadal germ cell tumors specifically. (shebaonline.org)
  • However, they can sometimes settle in other parts of the body (such as the bottom of the spine, the brain, chest and abdomen) where they can develop into tumours known as extragonadal germ cell tumours. (supershoes.org.uk)
  • Treatment and outcome of patients with extragonadal germ cell tumours--the Norwegian Radium Hospital's experience 1979-94. (medscape.com)
  • Ovarian germ cell tumors are more common in adolescent girls and young women. (cigna.com)
  • Gershenson DM: Update on malignant ovarian germ cell tumors. (kaiserpermanente.org)
  • Adjuvant therapy of ovarian germ cell tumors with cisplatin, etoposide, and bleomycin: a trial of the Gynecologic Oncology Group. (kaiserpermanente.org)
  • Malignant ovarian germ cell tumors: identification of novel prognostic markers and long-term outcome after multimodality treatment. (kaiserpermanente.org)
  • Extragonadal and pediatric germ cell tumors. (qxmd.com)
  • Pediatric germ cell tumors share many of the biologic characteristics of the adult tumors but are more likely to be benign. (qxmd.com)
  • Many patients with extragonadal germ cell tumors have histories of infertility, and testicular biopsy in these patients shows various abnormalities, including decreased spermatogenesis, peritubular fibrosis, and interstitial edema. (health.am)
  • Four of 22 consecutive patients (18%) treated at Indiana University for primary mediastinal germ cell tumors had karyotypic confirmation of Klinefelter syndrome, and an additional patient had clinical features. (health.am)
  • Foci of malignant lymphoblasts have been recognized histologically in several mediastinal germ cell tumors. (health.am)
  • According to this theory, the differences in phenotypes expressed by mediastinal germ cell tumors (MGCTs) and gonadal germ cell tumors may be explained by differences in the cellular environment between the gonad and the anterior mediastinum. (medscape.com)
  • An unusual aspect of mediastinal germ cell tumors, in particular, is their association with nontreatment-related hematologic malignancies. (qxmd.com)
  • Hematologic malignancies are frequently associated with mediastinal germ cell tumors. (medscape.com)
  • Highly differentiated yolk-sac tumors make up 30% of mediastinal germ cell tumors, providing a possible basis for this association. (medscape.com)
  • Mediastinal germ cell tumour associated with Klinefelter syndrome. (medscape.com)
  • In this study, the protective effect of a fermented wheat germ extract (FWGE) against LPS-induced inflammation and oxidative stress in IPEC-J2 porcine intestinal epithelial cells was studied. (hindawi.com)
  • Thus, eukaryotic in vitro systems, specifically the wheat germ cell-free system, hold significant promise. (iucr.org)
  • Microscopic observation of human airway ciliary movement using wheat germ agglutinin. (bvsalud.org)
  • To address this issue, we developed a method for labeling airway motile cilia with fluorescently labeled wheat germ agglutinin (FL-WGA). (bvsalud.org)
  • These are called gonadal germ cell tumours. (supershoes.org.uk)
  • It is possible for germ cell tumours to develop in other parts of the body. (supershoes.org.uk)
  • Germ Cell Tumours are treated with surgery, chemo or a combination of both. (supershoes.org.uk)
  • Around 45 children in the UK are diagnosed with Germ Cell Tumours each year and they can affect children of any age. (supershoes.org.uk)
  • Imaging of testicular germ cell tumours. (qxmd.com)
  • This article reviews the role of imaging of testicular germ cell tumours. (qxmd.com)
  • We investigated the role of occupational HMs and WFs exposures on the risk of testicular germ cell tumours (TGCT) in the TESTIS study. (who.int)
  • However, in view of the excellent chemosensitivity of germ cell cancers, clinical judgment can be used if surgical management would significantly increase postoperative morbidity. (medscape.com)
  • About 2-3% of all ovarian cancers are germ cell tumors. (cancer.org)
  • Germ cell tumors account for approximately 2 to four percentage of all cancers in kids and youngsters less youthful than age 20. (satyughealthcare.com)
  • Germ cell cancers are not common, which is why it is critical to choose a medical center with top tier technologies and specialists who are experienced in diagnosing and treating the disease. (shebaonline.org)
  • Germ cell brain tumors usually form in the center of the brain, near the pineal gland. (texaschildrens.org)
  • Germ cell tumors of the brain are rare, accounting for approximately 4 percent of brain tumors in children. (dana-farber.org)
  • Intracranial Germ Cell Tumors (iGCTs) are rare brain tumors that originate from embryonic germ cells. (researchsquare.com)
  • Therefore the application of immunotherapy has driven the treatment of brain tumors to the study of the response of intratumoral and systemic immune cells and cytokines to these malignancies 10 - 12 . (researchsquare.com)
  • Germ cell tumors of the ovary are uncommon but aggressive tumors, seen most often in young women and adolescent girls. (kaiserpermanente.org)
  • Some studies have found that size and histology were the major factors determining prognosis for patients with malignant mixed germ cell tumors of the ovary. (kaiserpermanente.org)
  • Germ cell tumors generally only affect one ovary. (medicalnewstoday.com)
  • Treatment for childhood Germ Cell Tumors often includes surgery. (mdanderson.org)
  • Childhood extracranial germ cell tumors form from germ cells in parts of the body other than the brain. (cigna.com)
  • For information on intracranial (inside the brain) germ cell tumors, see Childhood Central Nervous System Germ Cell Tumors Treatment. (cigna.com)
  • Childhood extracranial germ cell tumors may be benign or malignant. (cigna.com)
  • Childhood extracranial germ cell tumors are grouped as gonadal or extragonadal extracranial tumors. (cigna.com)
  • Testicular germ cell tumors in adolescents (11 years and older) and young adults are different from those that form in early childhood. (cigna.com)
  • In children younger than 11 years, extragonadal extracranial germ cell tumors usually occur at birth or in early childhood. (cigna.com)
  • The presence of sarcomatous components (SC) in gonadal or extragonadal germ cell tumors (GCT) is an infrequent phenomenon whose clinical outcome and biological significance remains unsettled. (biomedcentral.com)
  • Under special conditions in vitro germ cells can acquire properties similar to those of embryonic stem cells (ESCs). (wikipedia.org)
  • Nevertheless, human PGC-like cells can be generated, albeit at very low frequency, by spontaneous differentiation of human embryonic stem cells (ESCs). (nature.com)
  • During mammalian development, embryonic stem cells undergo cell-fate decisions to commit to one of three germ layer lineages: ectoderm, mesoderm and endoderm. (harvard.edu)
  • Using a novel iterative framework developed in a companion manuscript, we have analyzed single-cell RNA-seq data obtained from mouse embryonic stem cells taken at various time points during early germ layer differentiation to identify cell types as well as the lineage relationships between these individual cell types. (harvard.edu)
  • They established culture systems for the southern white rhino, for which embryonic stem cells are available, and the northern white rhino, for which they used induced pluripotent stem cells derived from tissue samples. (izw-berlin.de)
  • Mammalian eggs are somewhat symmetrical and after the first divisions of the fertilized egg, the produced cells are all totipotent. (wikipedia.org)
  • In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. (wikipedia.org)
  • After transport, involving passive movements and active migration, germ cells arrive at the developing gonads. (wikipedia.org)
  • After splitting into two populations, the germ cells continue migrating laterally and in parallel until they reach the gonads. (wikipedia.org)
  • Usually, germ cells migrate to the gonads during fetal development. (dana-farber.org)
  • Once in the mesoderm the bacteria cells correlate with the SGP groupings which migrate CP-724714 towards each additional at stage 13, and small at stage 14, leading to the bacteria cells to coalesce developing the bilateral embryonic gonads. (woofahs.com)
  • In a work published in Environmental Pollution , researchers from iRCM's LDG laboratory explored the effects of exposure to two bisphenol A substitutes, BADGE and BPAF, on murine germ cells, and more specifically on oocytes and their precursors. (cea.fr)
  • The second way is found in mammals, where germ cells are not specified by such determinants but by signals controlled by zygotic genes. (wikipedia.org)
  • Within a few days, a large proportion of cells formed in embryoid bodies expressed NANOS3-mCherry as well as other key PGC genes, indicating that they were probably nascent germ cells. (nature.com)
  • This study retrospectively analyzed serum lymphocyte subsets and survival outcomes in intracranial germ cell tumors (iGCTs) patients. (researchsquare.com)
  • The balance of the p53-mdm2 interaction has been shown to be disrupted in intracranial germ cell tumors (ICGCTs). (medscape.com)
  • Alterations of the INK4a/ARF locus in human intracranial germ cell tumors. (medscape.com)
  • Clinical relevance of the i(12p) marker chromosome in germ cell tumors. (medscape.com)
  • Extragonadal germ cell tumors: clinical presentation and management. (medscape.com)
  • Positron emission tomography in the clinical staging of patients with Stage I and II testicular germ cell tumors. (medscape.com)
  • Germ cell tumors are on these crossroads, and allow investigations related to genomic (in)stability, regulation of pluripotency, toxicology and clinical treatment efficacy. (maximabutterfly.com)
  • The clinical course is more aggressive than testicular seminomatous germ cell tumors with rapid involvement of blood vessels and a poorer prognosis. (globalgenes.org)
  • Treatment should be planned according to clinical signs and symptoms and can vary from simple curettage associated with conservative therapies to en-bloc resection 25 . (bvsalud.org)
  • Although like testicular germ cell tumors, these tumors are chemotherapeutically responsive, the overall prognosis is not as good. (qxmd.com)
  • This summary is about germ cell tumors that form in parts of the body that are extracranial (outside the brain). (cigna.com)
  • Extracranial germ cell tumors are most common in adolescents, with rates in this age group lower for females than males. (cigna.com)
  • Malignant extracranial germ cell tumors are tumors that form outside the brain. (cigna.com)
  • Most extragonadal extracranial germ cell tumors form along the midline of the body. (cigna.com)
  • In older children, adolescents, and young adults (11 years and older), extragonadal extracranial germ cell tumors are often in the mediastinum. (cigna.com)
  • Extracranial and extragonadal germ cell tumors and melanoma were both significantly decreasing. (cdc.gov)
  • The classic theory suggests that germ cell tumors (GCTs) in these areas are derived from local transformation of primordial germ cells misplaced during embryogenesis. (medscape.com)
  • Prior to the clas- sification work, the technical guidance for classification of germ cell mutagens was prepared. (cdc.gov)
  • Rusner C, Trabert B, Katalinic A, Kieschke J, Emrich K, Stang A. Incidence patterns and trends of malignant gonadal and extragonadal germ cell tumors in Germany, 1998-2008. (medscape.com)
  • In boys, the incidence of germ cell tumors peaks at around two years old, then declines and only increases again in adolescence. (shebaonline.org)
  • Testicular germ cell tumors make up 0.5% of pediatric malignancies, and 14% of adolescent malignancies. (urotoday.com)
  • Instead, germ cells can arise from somatic cells in the adult, such as the floral meristem of flowering plants. (wikipedia.org)
  • Multicellular eukaryotes are made of two fundamental cell types: germ and somatic. (wikipedia.org)
  • Somatic cells are all the other cells that form the building blocks of the body and they only divide by mitosis. (wikipedia.org)
  • Using single-cell RNA sequencing (RNAseq), we studied the development of ProSG, their SG descendants and testicular somatic cells during the perinatal period in mice. (biologists.com)
  • We also molecularly defined the development of Sertoli, Leydig and peritubular myoid cells during the perinatal period, allowing us to identify candidate signaling pathways acting between somatic and germ cells in a stage-specific manner during the perinatal period. (biologists.com)
  • During gastrulation the bacteria cells to the root somatic cells and become internalized adhere, putting the bacteria cells inside the posterior midgut pocket by embryonic stage 9. (woofahs.com)
  • Before the announcement in February 1997 of the cloning of a sheep by somatic cell nuclear transfer, existing legislation in a number of countries already precluded human cloning for reproductive purposes, sometimes implicitly. (who.int)
  • Study and manipulation of male germ line stem cells has implications for control of fertility, large animal transgenesis and genetic preservation. (upenn.edu)
  • Both cell types are pluripotent in vitro, but only ESCs have proven pluripotency in vivo. (wikipedia.org)
  • Throughout this thesis, I analyzed the methylation patterns of germ cells and embryos to determine whether in vitro maturation and in vitro fertilization have a negative impact on the epigenetic patterns. (uni-wuerzburg.de)
  • Our findings reveal that cell types found during early in vitro germ layer differentiation are discrete both transcriptionally as well as functionally. (harvard.edu)
  • Testicular germ cell tumors usually occur before the age of 4 years or in adolescents and young adults. (cigna.com)
  • Endodermal cells differentiate and together with Wunen proteins they induce the migration through the gut. (wikipedia.org)
  • This also includes a migration of the cells in the body (PGC migration). (izw-berlin.de)
  • In lures, a crucial participant that manages bacteria cell migration can be the enzyme 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (Hmgcr). (woofahs.com)
  • 2001). Several different types of CP-724714 experiments CP-724714 were used to analyze Hh function in germ cell migration. (woofahs.com)
  • 1998). Second, the authors report that ectopic expression of leads to germ cell migration defects (Deshpande et al. (woofahs.com)
  • 2001). Third, the authors report that mutating maternal components of the Hh signaling pathway leads to germ cell migration defects in the progeny (Deshpande et al. (woofahs.com)
  • 2001). Fourth, the authors report that Hmgcr promotes Hh signaling in particular CP-724714 through release or transmission of the Hh ligand and postulate that the function of Hmgcr in germ cell migration is to promote Hh signaling (Deshpande and Schedl, 2005). (woofahs.com)