The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type.
The formation of clumps of RED BLOOD CELLS under low or non-flow conditions, resulting from the attraction forces between the red blood cells. The cells adhere to each other in rouleaux aggregates. Slight mechanical force, such as occurs in the circulation, is enough to disperse these aggregates. Stronger or weaker than normal aggregation may result from a variety of effects in the ERYTHROCYTE MEMBRANE or in BLOOD PLASMA. The degree of aggregation is affected by ERYTHROCYTE DEFORMABILITY, erythrocyte membrane sialylation, masking of negative surface charge by plasma proteins, etc. BLOOD VISCOSITY and the ERYTHROCYTE SEDIMENTATION RATE are affected by the amount of erythrocyte aggregation and are parameters used to measure the aggregation.
The internal resistance of the BLOOD to shear forces. The in vitro measure of whole blood viscosity is of limited clinical utility because it bears little relationship to the actual viscosity within the circulation, but an increase in the viscosity of circulating blood can contribute to morbidity in patients suffering from disorders such as SICKLE CELL ANEMIA and POLYCYTHEMIA.
Adherence of cells to surfaces or to other cells.
The aggregation of suspended solids into larger clumps.
The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.
Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.
Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.
Methylmaleic anhydrides.
A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.
Ability of ERYTHROCYTES to change shape as they pass through narrow spaces, such as the microvasculature.
Calcium-dependent cell adhesion proteins. They are important in the formation of ADHERENS JUNCTIONS between cells. Cadherins are classified by their distinct immunological and tissue specificities, either by letters (E- for epithelial, N- for neural, and P- for placental cadherins) or by numbers (cadherin-12 or N-cadherin 2 for brain-cadherin). Cadherins promote cell adhesion via a homophilic mechanism as in the construction of tissues and of the whole animal body.
The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.
Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.
Encrustations, formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedding in extracellular polymers, that adhere to surfaces such as teeth (DENTAL DEPOSITS); PROSTHESES AND IMPLANTS; and catheters. Biofilms are prevented from forming by treating surfaces with DENTIFRICES; DISINFECTANTS; ANTI-INFECTIVE AGENTS; and antifouling agents.
The phylum of sponges which are sessile, suspension-feeding, multicellular animals that utilize flagellated cells called choanocytes to circulate water. Most are hermaphroditic. They are probably an early evolutionary side branch that gave rise to no other group of animals. Except for about 150 freshwater species, sponges are marine animals. They are a source of ALKALOIDS; STEROLS; and other complex molecules useful in medicine and biological research.
Members of the integrin family appearing late after T-cell activation. They are a family of proteins initially identified at the surface of stimulated T-cells, but now identified on a variety of cell types. At least six VLA antigens have been identified as heterodimeric adhesion receptors consisting of a single common beta-subunit and different alpha-subunits.
Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.
Surface ligands that mediate cell-to-cell adhesion and function in the assembly and interconnection of the vertebrate nervous system. These molecules promote cell adhesion via a homophilic mechanism. These are not to be confused with NEURAL CELL ADHESION MOLECULES, now known to be expressed in a variety of tissues and cell types in addition to nervous tissue.
Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.
The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.
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.
A species of motile, free-living, gram-negative bacteria that occur in the soil. They are aerobic or microaerophilic and are sometimes capable of nitrogen fixation.
An integrin heterodimer widely expressed on cells of hematopoietic origin. CD11A ANTIGEN comprises the alpha chain and the CD18 antigen (ANTIGENS, CD18) the beta chain. Lymphocyte function-associated antigen-1 is a major receptor of T-CELLS; B-CELLS; and GRANULOCYTES. It mediates the leukocyte adhesion reactions underlying cytolytic conjugate formation, helper T-cell interactions, and antibody-dependent killing by NATURAL KILLER CELLS and granulocytes. Intracellular adhesion molecule-1 has been defined as a ligand for lymphocyte function-associated antigen-1.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A division of organisms that exist vegetatively as complex mobile plasmodia, reproduce by means of spores, and have complex life cycles. They are now classed as protozoa but formerly were considered fungi.
A cultured line of C3H mouse FIBROBLASTS that do not adhere to one another and do not express CADHERINS.
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.
Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.
Established cell cultures that have the potential to propagate indefinitely.
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.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.
The rate dynamics in chemical or physical systems.
A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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.
Antibodies produced by a single clone of cells.
A non-pathogenic species of LACTOCOCCUS found in DAIRY PRODUCTS and responsible for the souring of MILK and the production of LACTIC ACID.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
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.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
A series of progressive, overlapping events, triggered by exposure of the PLATELETS to subendothelial tissue. These events include shape change, adhesiveness, aggregation, and release reactions. When carried through to completion, these events lead to the formation of a stable hemostatic plug.
Chemically stimulated aggregation of cell surface receptors, which potentiates the action of the effector cell.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The movement of cells or organisms toward or away from a substance in response to its concentration gradient.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Proteins prepared by recombinant DNA technology.
Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.
A cell-surface ligand involved in leukocyte adhesion and inflammation. Its production is induced by gamma-interferon and it is required for neutrophil migration into inflamed tissue.
A fibrous protein complex that consists of proteins folded into a specific cross beta-pleated sheet structure. This fibrillar structure has been found as an alternative folding pattern for a variety of functional proteins. Deposits of amyloid in the form of AMYLOID PLAQUES are associated with a variety of degenerative diseases. The amyloid structure has also been found in a number of functional proteins that are unrelated to disease.
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.
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.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.
Proteins found in any species of bacterium.
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
A cell line derived from cultured tumor cells.
Elements of limited time intervals, contributing to particular results or situations.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.
A synuclein that is a major component of LEWY BODIES that plays a role in neurodegeneration and neuroprotection.
Duration of blood flow after skin puncture. This test is used as a measure of capillary and platelet function.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
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.
A family of transmembrane glycoproteins (MEMBRANE GLYCOPROTEINS) consisting of noncovalent heterodimers. They interact with a wide variety of ligands including EXTRACELLULAR MATRIX PROTEINS; COMPLEMENT, and other cells, while their intracellular domains interact with the CYTOSKELETON. The integrins consist of at least three identified families: the cytoadhesin receptors(RECEPTORS, CYTOADHESIN), the leukocyte adhesion receptors (RECEPTORS, LEUKOCYTE ADHESION), and the VERY LATE ANTIGEN RECEPTORS. Each family contains a common beta-subunit (INTEGRIN BETA CHAINS) combined with one or more distinct alpha-subunits (INTEGRIN ALPHA CHAINS). These receptors participate in cell-matrix and cell-cell adhesion in many physiologically important processes, including embryological development; HEMOSTASIS; THROMBOSIS; WOUND HEALING; immune and nonimmune defense mechanisms; and oncogenic transformation.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
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.
Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
An unstable intermediate between the prostaglandin endoperoxides and thromboxane B2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (RCS).
The sum of the weight of all the atoms in a molecule.
Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.
Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
Methods for maintaining or growing CELLS in vitro.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
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.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
Glycoproteins found on the membrane or surface of cells.
A stable, physiologically active compound formed in vivo from the prostaglandin endoperoxides. It is important in the platelet-release reaction (release of ADP and serotonin).
The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.
Laboratory examination used to monitor and evaluate platelet function in a patient's blood.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
Peptides generated from AMYLOID BETA-PEPTIDES PRECURSOR. An amyloid fibrillar form of these peptides is the major component of amyloid plaques found in individuals with Alzheimer's disease and in aged individuals with trisomy 21 (DOWN SYNDROME). The peptide is found predominantly in the nervous system, but there have been reports of its presence in non-neural tissue.
A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.

Mechanisms of GDF-5 action during skeletal development. (1/2029)

Mutations in GDF-5, a member of the TGF-beta superfamily, result in the autosomal recessive syndromes brachypod (bp) in mice and Hunter-Thompson and Grebe-type chondrodysplasias in humans. These syndromes are all characterised by the shortening of the appendicular skeleton and loss or abnormal development of some joints. To investigate how GDF-5 controls skeletogenesis, we overexpressed GDF-5 during chick limb development using the retrovirus, RCASBP. This resulted in up to a 37.5% increase in length of the skeletal elements, which was predominantly due to an increase in the number of chondrocytes. By injecting virus at different stages of development, we show that GDF-5 can increase both the size of the early cartilage condensation and the later developing skeletal element. Using in vitro micromass cultures as a model system to study the early steps of chondrogenesis, we show that GDF-5 increases chondrogenesis in a dose-dependent manner. We did not detect changes in proliferation. However, cell suspension cultures showed that GDF-5 might act at these stages by increasing cell adhesion, a critical determinant of early chondrogenesis. In contrast, pulse labelling experiments of GDF-5-infected limbs showed that at later stages of skeletal development GDF-5 can increase proliferation of chondrocytes. Thus, here we show two mechanisms of how GDF-5 may control different stages of skeletogenesis. Finally, our data show that levels of GDF-5 expression/activity are important in controlling the size of skeletal elements and provides a possible explanation for the variation in the severity of skeletal defects resulting from mutations in GDF-5.  (+info)

Analysis of the stimulation-inhibition paradox exhibited by lymphocytes exposed to concanavalin A. (2/2029)

High doses of Concanavalin A (Con A), which normally inhibit T-lymphocyte stimulation as measured by increases in DNA synthesis, cause these lymphocytes to become committed to mitogenesis while also generating a dominant but reversible negative growth signal. The observed response to the stimulatory signal as measured by the rate of commitment to enter the S phase (i.e., the rate at which the stimulation becomes lectin independent) increases with lectin concentration even in the inhibitory range. The generation of this positive signal is prevented by treating the cells with colchicine. Cells that have become committed but are also simultaneously blocked from entering the S phase by the high doses of Con A can begin synthesizing DNA if the lectin is released by adding a competitive inhibitor of binding. Experiments done in agarose cultures in which lymphocytes are kept from contact with each other suggest that the reversible inhibitory signal is mediated by structures in the individual cells rather than as a result of agglutination. Continuously dividing cells of the lymphoid line P388 are also individually and reversibly inhibited by Con A. These findings are considered in terms of the relation of the inhibitory signal to the microtubular components of cell surface modulating assemblies made up of submembranous arrays of microtubules, microfilaments, and associated proteins.  (+info)

The pro-phenoloxidase of coleopteran insect, Tenebrio molitor, larvae was activated during cell clump/cell adhesion of insect cellular defense reactions. (3/2029)

To characterize the proteins involved in cell clump/cell adhesion of insect cellular defense reactions, we induced the cell clump/cell adhesion reaction in vitro with the hemolymph of larvae of the coleopteran insect, Tenebrio molitor. The 72 kDa protein was specifically enriched in the residues of cell clump/cell adhesion and was purified to homogeneity. A cDNA clone for the 72 kDa protein was isolated. We found that the 72 kDa protein was an activated phenoloxidase from Tenebrio pro-phenoloxidase. We suggest that activated phenoloxidase is involved in the cell clump/cell adhesion reaction as well as in the synthesis of melanin.  (+info)

Distinct functions of alpha3 and alpha(v) integrin receptors in neuronal migration and laminar organization of the cerebral cortex. (4/2029)

Changes in specific cell-cell recognition and adhesion interactions between neurons and radial glial cells regulate neuronal migration as well as the establishment of distinct layers in the developing cerebral cortex. Here, we show that alpha3beta1 integrin is necessary for neuron-glial recognition during neuronal migration and that alpha(v) integrins provide optimal levels of the basic neuron-glial adhesion needed to maintain neuronal migration on radial glial fibers. A gliophilic-to-neurophilic switch in the adhesive preference of developing cortical neurons occurs following the loss of alpha3beta1 integrin function. Furthermore, the targeted mutation of the alpha3 integrin gene results in abnormal layering of the cerebral cortex. These results suggest that alpha3beta1 and alpha(v) integrins regulate distinct aspects of neuronal migration and neuron-glial interactions during corticogenesis.  (+info)

Multiple developmental roles for CRAC, a cytosolic regulator of adenylyl cyclase. (5/2029)

Receptor-mediated activation of adenylyl cyclase (ACA) in Dictyostelium requires CRAC protein. Upon translocation to the membrane, this pleckstrin homology (PH) domain protein stimulates ACA and thereby mediates developmental aggregation. CRAC may also have roles later in development since CRAC-null cells can respond to chemotactic signals and participate in developmental aggregation when admixed with wild-type cells, but they do not complete development within such chimeras. To test whether the role of CRAC in postaggregative development is related to the activation of ACA, chemotactic aggregation was bypassed in CRAC-null cells by activating the cAMP-dependent protein kinase (PKA). While such strains formed mounds, they did not complete fruiting body morphogenesis or form spores. Expression of CRAC in the prespore cells of these strains rescued sporulation and fruiting body formation. This later function of CRAC does not appear to require its PH domain since the C-terminal portion of the protein (CRAC-DeltaPH) can substitute for full-length CRAC in promoting spore cell formation and morphogenesis. No detectable ACA activation was observed in any of the CRAC-null strains rescued by PKA activation and expression of CRAC-DeltaPH. Finally, we found that the development of CRAC-null ACA-null double mutants could be rescued by the activation of PKA together with the expression of CRAC-DeltaPH. Thus, there appears to be a required function for CRAC in postaggregative development that is independent of its previously described function in the ACA activation pathway.  (+info)

Origin of the integrin-mediated signal transduction. Functional studies with cell cultures from the sponge Suberites domuncula. (6/2029)

Sponges (phylum Porifera) represent the phylogenetically oldest metazoan animals. Recently, from the marine sponge Geodia cydonium a first cDNA encoding a putative integrin receptor molecule was isolated. In the present study basic functional experiments have been conducted to test the hypothesis that in sponges integrin polypeptides also function as adhesion molecules and as outside-in signaling molecules. The sponge Suberites domuncula has been used for the experiments because from this sponge only has a cell culture been established. Here we report that aggregation factor (AF)-mediated cell-cell adhesion is blocked by the RGDS peptide which is known to interact with beta integrin. Both RGDS and AF were found to stimulate DNA synthesis within 24 h. The beta subunit of the integrin receptor was cloned from S. domuncula; the estimated 91-kDa molecule comprises the characteristic signatures. Evolutionary conservation of the beta integrin was assessed by comparison with corresponding beta integrin subunits from evolutionary higher metazoan taxa. Addition of RGDS or of AF to isolated cells of S. domuncula causes a rapid (within 1-2 min) increase in the intracellular Ca2+ concentration which is further augmented in the presence of Ca2+. Furthermore, incubation of the cells with RGDS or AF causes an activation of the GTP-binding protein Ras. In addition it is shown that after a prolonged incubation of the cells with RGDS and AF the expression of the genes coding for Ras and for calmodulin is upregulated. These results suggest that the integrin receptor functions in the sponge system not only as adhesion molecule but also as a molecule involved in outside-in signaling.  (+info)

E-cadherin mediates aggregation-dependent survival of prostate and mammary epithelial cells through the retinoblastoma cell cycle control pathway. (7/2029)

E-cadherin and the retinoblastoma tumor suppressor (Rb) are traditionally associated with diverse regulatory aspects of cell growth and differentiation. However, we have discovered new evidence, which suggests that these proteins are functionally linked in a physiologic pathway required for cell survival and programmed cell death. Pharmacological activation of protein kinase C (PKC) or inducible overexpression and activation of the alpha isozyme of PKC (PKCalpha) resulted in approximately 60% apoptosis of mammary and prostate epithelial cells. Interestingly, the surviving cells had undergone dramatic aggregation concurrent with increased E-cadherin expression. When aggregation was inhibited by the addition of an E-cadherin-blocking antibody, apoptosis increased synergistically. We hypothesized that survival of the aggregated population was associated with contact-inhibited growth and that apoptosis might result from aberrant growth regulatory signals in non-aggregated, cycling cells. This hypothesis was confirmed by experiments that demonstrated that E-cadherin-dependent aggregation resulted in Rb-mediated G1 arrest and survival. Immunoblot analysis and flow cytometry revealed that hypophosphorylated Rb was present in non-aggregated, S phase cultures concurrent with synergistic cell death. We have also determined that the loss of membrane E-cadherin and subsequent hypophosphorylation of Rb in luminal epithelial cells preceded apoptosis induced by castration. These findings provide compelling evidence that suggests that E-cadherin-mediated aggregation results in Rb activation and G1 arrest that is critical for survival of prostate and mammary epithelial cells. These data also indicate that Rb can initiate a fatal growth signal conflict in non-aggregated, cycling cells when the protein is hypophosphorylated as these epithelial cells enter S phase.  (+info)

Differential responses to CD40 ligation among Burkitt lymphoma lines that are uniformly responsive to Epstein-Barr virus latent membrane protein 1. (8/2029)

Ligation of CD40 on the surface of B cells induces multiple phenotypic effects, many of which are mimicked by the EBV latent membrane protein 1 (LMP1) through its interaction with downstream components of the CD40 signaling pathway. Because the effects of LMP1 have been most closely studied in human Burkitt Lymphoma (BL) cell lines retaining a tumor biopsy-like phenotype in vitro, we have examined the response of a panel of such lines to CD40 ligation. Two distinct patterns of response were observed that were unrelated to the surface level of CD40 or to the EBV genome status of the lines. Following exposure to either CD40-specific mAbs or the soluble trimeric ligand (sCD40L), high responder (HR) lines showed rapid aggregation, activation of NF-kappa B, up-regulation of cell surface markers ICAM-1/CD54 and Fas/CD95, and growth inhibition. Aggregation was seen at lower doses than those required to elicit the other effects. By contrast, low responder (LR) lines showed no detectable response to CD40 mAbs, while their responses to sCD40L were limited to activation of NF-kappa B and up-regulation of CD95 only. However, in transfection experiments, LMP1 uniformly induced the full spectrum of phenotypic effects in both HR and LR lines. We conclude that some BL cell lines show a highly restricted response to CD40 ligation but remain fully susceptible to LMP1.  (+info)

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

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

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

Erythrocyte aggregation, also known as rouleaux formation, is the clumping together of red blood cells (erythrocytes) in a way that resembles a stack of coins. This phenomenon is typically observed under low-shear conditions, such as those found in small blood vessels and capillaries.

The aggregation of erythrocytes is influenced by several factors, including the concentration of plasma proteins, the charge and shape of the red blood cells, and the flow characteristics of the blood. One of the most important proteins involved in this process is fibrinogen, a large plasma protein that can bridge between adjacent red blood cells and cause them to stick together.

Erythrocyte aggregation can have significant effects on blood flow and rheology (the study of how blood flows), particularly in diseases such as diabetes, sickle cell disease, and certain types of anemia. Increased erythrocyte aggregation can lead to reduced oxygen delivery to tissues, increased blood viscosity, and impaired microcirculatory flow, all of which can contribute to tissue damage and organ dysfunction.

Blood viscosity is a measure of the thickness or flow resistance of blood. It is defined as the ratio of shear stress to shear rate within the flowing blood, which reflects the internal friction or resistance to flow. Blood viscosity is primarily determined by the concentration and size of red blood cells (hematocrit), plasma proteins, and other blood constituents. An increase in any of these components can raise blood viscosity, leading to impaired blood flow, reduced oxygen delivery to tissues, and potential cardiovascular complications if not managed appropriately.

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

Flocculation is not a term that has a specific medical definition. However, it is a term that is used in various scientific and medical contexts to refer to the process of forming flocs or clumps. Flocs are aggregates of small particles that come together to form larger, visible clumps.

In medical contexts, flocculation may be used to describe the formation of clumps in biological samples such as urine or blood. For example, the presence of flocculent material in urine may indicate the presence of a protein abnormality or kidney disease. Similarly, flocculation of red blood cells may occur in certain medical conditions such as paroxysmal nocturnal hemoglobinuria (PNH), where red blood cells are susceptible to complement-mediated lysis and can form clumps in the blood.

Overall, while flocculation is not a term with a specific medical definition, it is a process that can have implications for various medical diagnoses and conditions.

Hemorheology is the study of the flow properties of blood and its components, including red blood cells, white blood cells, platelets, and plasma. Specifically, it examines how these components interact with each other and with the walls of blood vessels to affect the flow characteristics of blood under different conditions. Hemorheological factors can influence blood viscosity, which is a major determinant of peripheral vascular resistance and cardiac workload. Abnormalities in hemorheology have been implicated in various diseases such as atherosclerosis, hypertension, diabetes, and sickle cell disease.

Blood platelets, also known as thrombocytes, are small, colorless cell fragments in our blood that play an essential role in normal blood clotting. They are formed in the bone marrow from large cells called megakaryocytes and circulate in the blood in an inactive state until they are needed to help stop bleeding. When a blood vessel is damaged, platelets become activated and change shape, releasing chemicals that attract more platelets to the site of injury. These activated platelets then stick together to form a plug, or clot, that seals the wound and prevents further blood loss. In addition to their role in clotting, platelets also help to promote healing by releasing growth factors that stimulate the growth of new tissue.

Platelet aggregation inhibitors are a class of medications that prevent platelets (small blood cells involved in clotting) from sticking together and forming a clot. These drugs work by interfering with the ability of platelets to adhere to each other and to the damaged vessel wall, thereby reducing the risk of thrombosis (blood clot formation).

Platelet aggregation inhibitors are often prescribed for people who have an increased risk of developing blood clots due to various medical conditions such as atrial fibrillation, coronary artery disease, peripheral artery disease, stroke, or a history of heart attack. They may also be used in patients undergoing certain medical procedures, such as angioplasty and stenting, to prevent blood clot formation in the stents.

Examples of platelet aggregation inhibitors include:

1. Aspirin: A nonsteroidal anti-inflammatory drug (NSAID) that irreversibly inhibits the enzyme cyclooxygenase, which is involved in platelet activation and aggregation.
2. Clopidogrel (Plavix): A P2Y12 receptor antagonist that selectively blocks ADP-induced platelet activation and aggregation.
3. Prasugrel (Effient): A third-generation thienopyridine P2Y12 receptor antagonist, similar to clopidogrel but with faster onset and greater potency.
4. Ticagrelor (Brilinta): A direct-acting P2Y12 receptor antagonist that does not require metabolic activation and has a reversible binding profile.
5. Dipyridamole (Persantine): An antiplatelet agent that inhibits platelet aggregation by increasing cyclic adenosine monophosphate (cAMP) levels in platelets, which leads to decreased platelet reactivity.
6. Iloprost (Ventavis): A prostacyclin analogue that inhibits platelet aggregation and causes vasodilation, often used in the treatment of pulmonary arterial hypertension.
7. Cilostazol (Pletal): A phosphodiesterase III inhibitor that increases cAMP levels in platelets, leading to decreased platelet activation and aggregation, as well as vasodilation.
8. Ticlopidine (Ticlid): An older P2Y12 receptor antagonist with a slower onset of action and more frequent side effects compared to clopidogrel or prasugrel.

Citraconic anhydride is a chemical compound that is used in the synthesis of various pharmaceuticals and industrial products. It is an anhydride of citraconic acid, which is a unsaturated dicarboxylic acid. Citraconic anhydride is an important reagent in organic chemistry due to its ability to act as a acylating agent, meaning it can transfer an acyl group (a functional group consisting of a carbon atom double-bonded to an oxygen atom: -CO-) to other molecules.

In the medical field, citraconic anhydride is not used directly as a therapeutic agent. However, it may be used in the production of certain drugs or drug delivery systems. For example, it has been used in the synthesis of biodegradable polymers for drug delivery, and in the modification of proteins and peptides for therapeutic purposes.

It is important to note that citraconic anhydride itself is not a medication, but rather a chemical reagent used in the production of certain pharmaceutical compounds. As such, it does not have a specific medical definition, but rather a chemical one.

'Dictyostelium' is a genus of social amoebae that are commonly found in soil and decaying organic matter. These microscopic organisms have a unique life cycle, starting as individual cells that feed on bacteria. When food becomes scarce, the cells undergo a developmental process where they aggregate together to form a multicellular slug-like structure called a pseudoplasmodium or grex. This grex then moves and differentiates into a fruiting body that can release spores for further reproduction.

Dictyostelium discoideum is the most well-studied species in this genus, serving as a valuable model organism for research in various fields such as cell biology, developmental biology, and evolutionary biology. The study of Dictyostelium has contributed significantly to our understanding of fundamental biological processes like chemotaxis, signal transduction, and cell differentiation.

Erythrocyte deformability refers to the ability of red blood cells (erythrocytes) to change shape and bend without rupturing, which is crucial for their efficient movement through narrow blood vessels. This deformability is influenced by several factors including the cell membrane structure, hemoglobin concentration, and intracellular viscosity. A decrease in erythrocyte deformability can negatively impact blood flow and oxygen delivery to tissues, potentially contributing to various pathological conditions such as sickle cell disease, diabetes, and cardiovascular diseases.

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

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

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

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

Rheology is not a term that is specific to medicine, but rather it is a term used in the field of physics to describe the flow and deformation of matter. It specifically refers to the study of how materials flow or deform under various stresses or strains. This concept can be applied to various medical fields such as studying the flow properties of blood (hematology), understanding the movement of tissues and organs during surgical procedures, or analyzing the mechanical behavior of biological materials like bones and cartilages.

Cell adhesion molecules (CAMs) are a type of protein found on the surface of cells that mediate the attachment or adhesion of cells to either other cells or to the extracellular matrix (ECM), which is the network of proteins and carbohydrates that provides structural and biochemical support to surrounding cells.

CAMs play crucial roles in various biological processes, including tissue development, differentiation, repair, and maintenance of tissue architecture and function. They are also involved in cell signaling, migration, and regulation of the immune response.

There are several types of CAMs, classified based on their structure and function, such as immunoglobulin-like CAMs (IgCAMs), cadherins, integrins, and selectins. Dysregulation of CAMs has been implicated in various diseases, including cancer, inflammation, and neurological disorders.

Biofilms are defined as complex communities of microorganisms, such as bacteria and fungi, that adhere to surfaces and are enclosed in a matrix made up of extracellular polymeric substances (EPS). The EPS matrix is composed of polysaccharides, proteins, DNA, and other molecules that provide structural support and protection to the microorganisms within.

Biofilms can form on both living and non-living surfaces, including medical devices, implants, and biological tissues. They are resistant to antibiotics, disinfectants, and host immune responses, making them difficult to eradicate and a significant cause of persistent infections. Biofilms have been implicated in a wide range of medical conditions, including chronic wounds, urinary tract infections, middle ear infections, and device-related infections.

The formation of biofilms typically involves several stages, including initial attachment, microcolony formation, maturation, and dispersion. Understanding the mechanisms underlying biofilm formation and development is crucial for developing effective strategies to prevent and treat biofilm-associated infections.

Porifera, also known as sponges, is a phylum of multicellular aquatic organisms characterized by having pores in their bodies. These pores allow water to circulate through the body, bringing in food and oxygen while expelling waste products. Sponges do not have true tissues or organs; instead, they are composed of specialized cells that perform specific functions. They are generally sessile (non-mobile) and live attached to rocks, coral reefs, or other underwater structures. Some species can be quite large, while others are microscopic in size. Sponges have a long fossil record dating back over 500 million years and play important roles in marine ecosystems as filter feeders and habitat providers for many other marine organisms.

Very late antigens (VLAs) are a group of integrin receptors found on the surface of leukocytes (white blood cells) that play a role in various cellular functions, including adhesion, migration, and signaling. Specifically, VLA-4 is a heterodimeric integrin receptor composed of two subunits, alpha-4 (CD49d) and beta-1 (CD29).

The term "very late" refers to the time course of their expression during lymphocyte activation and differentiation. VLA-4 is expressed at low levels on resting leukocytes but is upregulated upon activation, making it a useful marker for activated immune cells.

VLA-4 mediates adhesion to various counter-receptors, including vascular cell adhesion molecule-1 (VCAM-1) and fibronectin, which are expressed on endothelial cells, facilitating the extravasation of leukocytes from the bloodstream into tissues during inflammation or immune responses.

Therefore, VLA-4 has been a target for therapeutic interventions in various inflammatory and autoimmune diseases, such as multiple sclerosis and rheumatoid arthritis.

Bacterial adhesion is the initial and crucial step in the process of bacterial colonization, where bacteria attach themselves to a surface or tissue. This process involves specific interactions between bacterial adhesins (proteins, fimbriae, or pili) and host receptors (glycoproteins, glycolipids, or extracellular matrix components). The attachment can be either reversible or irreversible, depending on the strength of interaction. Bacterial adhesion is a significant factor in initiating biofilm formation, which can lead to various infectious diseases and medical device-associated infections.

Cell adhesion molecules (CAMs) are a type of protein that mediates the attachment or binding of cells to their surrounding extracellular matrix or to other cells. Neuronal cell adhesion molecules (NCAMs) are a specific subtype of CAMs that are primarily expressed on neurons and play crucial roles in the development, maintenance, and function of the nervous system.

NCAMs are involved in various processes such as cell recognition, migration, differentiation, synaptic plasticity, and neural circuit formation. They can interact with other NCAMs or other types of CAMs to form homophilic or heterophilic bonds, respectively. The binding of NCAMs can activate intracellular signaling pathways that regulate various cellular responses.

NCAMs are classified into three major families based on their molecular structure: the immunoglobulin superfamily (Ig-CAMs), the cadherin family, and the integrin family. The Ig-CAMs include NCAM1 (also known as CD56), which is a glycoprotein with multiple extracellular Ig-like domains and intracellular signaling motifs. The cadherin family includes N-cadherin, which mediates calcium-dependent cell-cell adhesion. The integrin family includes integrins such as α5β1 and αVβ3, which mediate cell-matrix adhesion.

Abnormalities in NCAMs have been implicated in various neurological disorders, including schizophrenia, Alzheimer's disease, and autism spectrum disorder. Therefore, understanding the structure and function of NCAMs is essential for developing therapeutic strategies to treat these conditions.

Fibrinogen is a soluble protein present in plasma, synthesized by the liver. It plays an essential role in blood coagulation. When an injury occurs, fibrinogen gets converted into insoluble fibrin by the action of thrombin, forming a fibrin clot that helps to stop bleeding from the injured site. Therefore, fibrinogen is crucial for hemostasis, which is the process of stopping bleeding and starting the healing process after an injury.

Hematocrit is a medical term that refers to the percentage of total blood volume that is made up of red blood cells. It is typically measured as part of a complete blood count (CBC) test. A high hematocrit may indicate conditions such as dehydration, polycythemia, or living at high altitudes, while a low hematocrit may be a sign of anemia, bleeding, or overhydration. It is important to note that hematocrit values can vary depending on factors such as age, gender, and pregnancy status.

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.

'Azospirillum brasilense' is a species of free-living, nitrogen-fixing bacteria that is commonly found in the soil and in the roots of various plants. It belongs to the genus Azospirillum and is known for its ability to promote plant growth through a process called bacterial colonization. The bacteria colonize the root system of the plant and enhance nutrient uptake, leading to improved growth and yield. Additionally, 'Azospirillum brasilense' can convert atmospheric nitrogen into ammonia, making it available to the plants as a natural fertilizer. It is widely used in agricultural practices as a bioinoculant to improve crop productivity and sustainability.

Lymphocyte Function-Associated Antigen-1 (LFA-1) is a type of integrin, which is a family of cell surface proteins that are important for cell-cell adhesion and signal transduction. LFA-1 is composed of two subunits, called alpha-L (CD11a) and beta-2 (CD18), and it is widely expressed on various leukocytes, including T cells, B cells, and natural killer cells.

LFA-1 plays a crucial role in the immune system by mediating the adhesion of leukocytes to other cells, such as endothelial cells that line blood vessels, and extracellular matrix components. This adhesion is necessary for leukocyte migration from the bloodstream into tissues during inflammation or immune responses. LFA-1 also contributes to the activation of T cells and their interaction with antigen-presenting cells, such as dendritic cells and macrophages.

The binding of LFA-1 to its ligands, including intercellular adhesion molecule 1 (ICAM-1) and ICAM-2, triggers intracellular signaling pathways that regulate various cellular functions, such as cytoskeletal reorganization, gene expression, and cell survival. Dysregulation of LFA-1 function has been implicated in several immune-related diseases, including autoimmune disorders, inflammatory diseases, and cancer.

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

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

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

Myxomycetes are not a part of human or animal medicine, and thus do not have a medical definition. They are actually a group of organisms commonly known as plasmodial slime molds. These are single-celled amoeboid organisms that can aggregate under certain conditions to form a multinucleate mass called a plasmodium. When the plasmodium matures, it differentiates into fruiting bodies that release spores. Myxomycetes are not plants, animals or fungi, but are classified in their own kingdom, Protista. They are often found on dead plant material in moist, shaded habitats.

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.

Adenosine diphosphate (ADP) is a chemical compound that plays a crucial role in energy transfer within cells. It is a nucleotide, which consists of a adenosine molecule (a sugar molecule called ribose attached to a nitrogenous base called adenine) and two phosphate groups.

In the cell, ADP functions as an intermediate in the conversion of energy from one form to another. When a high-energy phosphate bond in ADP is broken, energy is released and ADP is converted to adenosine triphosphate (ATP), which serves as the main energy currency of the cell. Conversely, when ATP donates a phosphate group to another molecule, it is converted back to ADP, releasing energy for the cell to use.

ADP also plays a role in blood clotting and other physiological processes. In the coagulation cascade, ADP released from damaged red blood cells can help activate platelets and initiate the formation of a blood clot.

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.

"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.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

A chick embryo refers to the developing organism that arises from a fertilized chicken egg. It is often used as a model system in biological research, particularly during the stages of development when many of its organs and systems are forming and can be easily observed and manipulated. The study of chick embryos has contributed significantly to our understanding of various aspects of developmental biology, including gastrulation, neurulation, organogenesis, and pattern formation. Researchers may use various techniques to observe and manipulate the chick embryo, such as surgical alterations, cell labeling, and exposure to drugs or other agents.

Dextrans are a type of complex glucose polymers that are formed by the action of certain bacteria on sucrose. They are branched polysaccharides consisting of linear chains of α-1,6 linked D-glucopyranosyl units with occasional α-1,3 branches.

Dextrans have a wide range of applications in medicine and industry. In medicine, dextrans are used as plasma substitutes, volume expanders, and anticoagulants. They are also used as carriers for drugs and diagnostic agents, and in the manufacture of immunoadsorbents for the removal of toxins and pathogens from blood.

Dextrans can be derived from various bacterial sources, but the most common commercial source is Leuconostoc mesenteroides B-512(F) or L. dextranicum. The molecular weight of dextrans can vary widely, ranging from a few thousand to several million Daltons, depending on the method of preparation and purification.

Dextrans are generally biocompatible and non-toxic, but they can cause allergic reactions in some individuals. Therefore, their use as medical products requires careful monitoring and testing for safety and efficacy.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Edetic acid, also known as ethylenediaminetetraacetic acid (EDTA), is not a medical term per se, but a chemical compound with various applications in medicine. EDTA is a synthetic amino acid that acts as a chelating agent, which means it can bind to metallic ions and form stable complexes.

In medicine, EDTA is primarily used in the treatment of heavy metal poisoning, such as lead or mercury toxicity. It works by binding to the toxic metal ions in the body, forming a stable compound that can be excreted through urine. This helps reduce the levels of harmful metals in the body and alleviate their toxic effects.

EDTA is also used in some diagnostic tests, such as the determination of calcium levels in blood. Additionally, it has been explored as a potential therapy for conditions like atherosclerosis and Alzheimer's disease, although its efficacy in these areas remains controversial and unproven.

It is important to note that EDTA should only be administered under medical supervision due to its potential side effects and the need for careful monitoring of its use.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

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.

Monoclonal antibodies are a type of antibody that are identical because they are produced by a single clone of cells. They are laboratory-produced molecules that act like human antibodies in the immune system. They can be designed to attach to specific proteins found on the surface of cancer cells, making them useful for targeting and treating cancer. Monoclonal antibodies can also be used as a therapy for other diseases, such as autoimmune disorders and inflammatory conditions.

Monoclonal antibodies are produced by fusing a single type of immune cell, called a B cell, with a tumor cell to create a hybrid cell, or hybridoma. This hybrid cell is then able to replicate indefinitely, producing a large number of identical copies of the original antibody. These antibodies can be further modified and engineered to enhance their ability to bind to specific targets, increase their stability, and improve their effectiveness as therapeutic agents.

Monoclonal antibodies have several mechanisms of action in cancer therapy. They can directly kill cancer cells by binding to them and triggering an immune response. They can also block the signals that promote cancer growth and survival. Additionally, monoclonal antibodies can be used to deliver drugs or radiation directly to cancer cells, increasing the effectiveness of these treatments while minimizing their side effects on healthy tissues.

Monoclonal antibodies have become an important tool in modern medicine, with several approved for use in cancer therapy and other diseases. They are continuing to be studied and developed as a promising approach to treating a wide range of medical conditions.

"Lactococcus lactis" is a species of gram-positive, facultatively anaerobic bacteria that are commonly found in nature, particularly in environments involving plants and dairy products. It is a catalase-negative, non-spore forming coccus that typically occurs in pairs or short chains.

"Lactococcus lactis" has significant industrial importance as it plays a crucial role in the production of fermented foods such as cheese and buttermilk. The bacterium converts lactose into lactic acid, which contributes to the sour taste and preservative qualities of these products.

In addition to its use in food production, "Lactococcus lactis" has been explored for its potential therapeutic applications. It can be used as a vector for delivering therapeutic proteins or vaccines to the gastrointestinal tract due to its ability to survive and colonize there.

It's worth noting that "Lactococcus lactis" is generally considered safe for human consumption, and it's one of the most commonly used probiotics in food and supplements.

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.

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

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

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

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

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

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

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

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.

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

Platelet activation is the process by which platelets (also known as thrombocytes) become biologically active and change from their inactive discoid shape to a spherical shape with pseudopodia, resulting in the release of chemical mediators that are involved in hemostasis and thrombosis. This process is initiated by various stimuli such as exposure to subendothelial collagen, von Willebrand factor, or thrombin during vascular injury, leading to platelet aggregation and the formation of a platelet plug to stop bleeding. Platelet activation also plays a role in inflammation, immune response, and wound healing.

Receptor aggregation, also known as receptor clustering or patching, is a process that occurs when multiple receptor proteins, which are typically found dispersed on the cell membrane, come together and form a cluster or aggregate in response to a stimulus. This can occur through various mechanisms such as ligand-induced dimerization, conformational changes, or interactions with intracellular signaling molecules.

Receptor aggregation can lead to changes in receptor function, including increased sensitivity, altered signaling properties, and internalization of the receptors. This process plays an important role in various physiological processes such as cell signaling, immune response, and neuronal communication. However, abnormal receptor aggregation has also been implicated in several diseases, including cancer and neurological disorders.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Chemotaxis is a term used in biology and medicine to describe the movement of an organism or cell towards or away from a chemical stimulus. This process plays a crucial role in various biological phenomena, including immune responses, wound healing, and the development and progression of diseases such as cancer.

In chemotaxis, cells can detect and respond to changes in the concentration of specific chemicals, known as chemoattractants or chemorepellents, in their environment. These chemicals bind to receptors on the cell surface, triggering a series of intracellular signaling events that ultimately lead to changes in the cytoskeleton and directed movement of the cell towards or away from the chemical gradient.

For example, during an immune response, white blood cells called neutrophils use chemotaxis to migrate towards sites of infection or inflammation, where they can attack and destroy invading pathogens. Similarly, cancer cells can use chemotaxis to migrate towards blood vessels and metastasize to other parts of the body.

Understanding chemotaxis is important for developing new therapies and treatments for a variety of diseases, including cancer, infectious diseases, and inflammatory disorders.

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).

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

Fibronectin is a high molecular weight glycoprotein that is found in many tissues and body fluids, including plasma, connective tissue, and the extracellular matrix. It is composed of two similar subunits that are held together by disulfide bonds. Fibronectin plays an important role in cell adhesion, migration, and differentiation by binding to various cell surface receptors, such as integrins, and other extracellular matrix components, such as collagen and heparan sulfate proteoglycans.

Fibronectin has several isoforms that are produced by alternative splicing of a single gene transcript. These isoforms differ in their biological activities and can be found in different tissues and developmental stages. Fibronectin is involved in various physiological processes, such as wound healing, tissue repair, and embryonic development, and has been implicated in several pathological conditions, including fibrosis, tumor metastasis, and thrombosis.

Intercellular Adhesion Molecule-1 (ICAM-1), also known as CD54, is a transmembrane glycoprotein expressed on the surface of various cell types including endothelial cells, fibroblasts, and immune cells. ICAM-1 plays a crucial role in the inflammatory response and the immune system by mediating the adhesion of leukocytes (white blood cells) to the endothelium, allowing them to migrate into surrounding tissues during an immune response or inflammation.

ICAM-1 contains five immunoglobulin-like domains in its extracellular region and binds to several integrins present on leukocytes, such as LFA-1 (lymphocyte function-associated antigen 1) and Mac-1 (macrophage-1 antigen). This interaction facilitates the firm adhesion of leukocytes to the endothelium, which is a critical step in the extravasation process.

In addition to its role in inflammation and immunity, ICAM-1 has been implicated in several pathological conditions, including atherosclerosis, cancer, and autoimmune diseases. Increased expression of ICAM-1 on endothelial cells is associated with the recruitment of immune cells to sites of injury or infection, making it an important target for therapeutic interventions in various inflammatory disorders.

Amyloid is a term used in medicine to describe abnormally folded protein deposits that can accumulate in various tissues and organs of the body. These misfolded proteins can form aggregates known as amyloid fibrils, which have a characteristic beta-pleated sheet structure. Amyloid deposits can be composed of different types of proteins, depending on the specific disease associated with the deposit.

In some cases, amyloid deposits can cause damage to organs and tissues, leading to various clinical symptoms. Some examples of diseases associated with amyloidosis include Alzheimer's disease (where amyloid-beta protein accumulates in the brain), systemic amyloidosis (where amyloid fibrils deposit in various organs such as the heart, kidneys, and liver), and type 2 diabetes (where amyloid deposits form in the pancreas).

It's important to note that not all amyloid deposits are harmful or associated with disease. However, when they do cause problems, treatment typically involves managing the underlying condition that is leading to the abnormal protein accumulation.

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.

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.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

Protein folding is the process by which a protein molecule naturally folds into its three-dimensional structure, following the synthesis of its amino acid chain. This complex process is determined by the sequence and properties of the amino acids, as well as various environmental factors such as temperature, pH, and the presence of molecular chaperones. The final folded conformation of a protein is crucial for its proper function, as it enables the formation of specific interactions between different parts of the molecule, which in turn define its biological activity. Protein misfolding can lead to various diseases, including neurodegenerative disorders such as Alzheimer's and Parkinson's disease.

Glycoproteins are complex proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. These glycans are linked to the protein through asparagine residues (N-linked) or serine/threonine residues (O-linked). Glycoproteins play crucial roles in various biological processes, including cell recognition, cell-cell interactions, cell adhesion, and signal transduction. They are widely distributed in nature and can be found on the outer surface of cell membranes, in extracellular fluids, and as components of the extracellular matrix. The structure and composition of glycoproteins can vary significantly depending on their function and location within an organism.

Genetic conjugation is a type of genetic transfer that occurs between bacterial cells. It involves the process of one bacterium (the donor) transferring a piece of its DNA to another bacterium (the recipient) through direct contact or via a bridge-like connection called a pilus. This transferred DNA may contain genes that provide the recipient cell with new traits, such as antibiotic resistance or virulence factors, which can make the bacteria more harmful or difficult to treat. Genetic conjugation is an important mechanism for the spread of antibiotic resistance and other traits among bacterial populations.

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

Cyclic adenosine monophosphate (cAMP) is a key secondary messenger in many biological processes, including the regulation of metabolism, gene expression, and cellular excitability. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase and is degraded by the enzyme phosphodiesterase.

In the body, cAMP plays a crucial role in mediating the effects of hormones and neurotransmitters on target cells. For example, when a hormone binds to its receptor on the surface of a cell, it can activate a G protein, which in turn activates adenylyl cyclase to produce cAMP. The increased levels of cAMP then activate various effector proteins, such as protein kinases, which go on to regulate various cellular processes.

Overall, the regulation of cAMP levels is critical for maintaining proper cellular function and homeostasis, and abnormalities in cAMP signaling have been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Scanning electron microscopy (SEM) is a type of electron microscopy that uses a focused beam of electrons to scan the surface of a sample and produce a high-resolution image. In SEM, a beam of electrons is scanned across the surface of a specimen, and secondary electrons are emitted from the sample due to interactions between the electrons and the atoms in the sample. These secondary electrons are then detected by a detector and used to create an image of the sample's surface topography. SEM can provide detailed images of the surface of a wide range of materials, including metals, polymers, ceramics, and biological samples. It is commonly used in materials science, biology, and electronics for the examination and analysis of surfaces at the micro- and nanoscale.

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

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

Examples of recombinant fusion proteins include:

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

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.

'Tumor cells, cultured' refers to the process of removing cancerous cells from a tumor and growing them in controlled laboratory conditions. This is typically done by isolating the tumor cells from a patient's tissue sample, then placing them in a nutrient-rich environment that promotes their growth and multiplication.

The resulting cultured tumor cells can be used for various research purposes, including the study of cancer biology, drug development, and toxicity testing. They provide a valuable tool for researchers to better understand the behavior and characteristics of cancer cells outside of the human body, which can lead to the development of more effective cancer treatments.

It is important to note that cultured tumor cells may not always behave exactly the same way as they do in the human body, so findings from cell culture studies must be validated through further research, such as animal models or clinical trials.

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

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.

CHO cells, or Chinese Hamster Ovary cells, are a type of immortalized cell line that are commonly used in scientific research and biotechnology. They were originally derived from the ovaries of a female Chinese hamster (Cricetulus griseus) in the 1950s.

CHO cells have several characteristics that make them useful for laboratory experiments. They can grow and divide indefinitely under appropriate conditions, which allows researchers to culture large quantities of them for study. Additionally, CHO cells are capable of expressing high levels of recombinant proteins, making them a popular choice for the production of therapeutic drugs, vaccines, and other biologics.

In particular, CHO cells have become a workhorse in the field of biotherapeutics, with many approved monoclonal antibody-based therapies being produced using these cells. The ability to genetically modify CHO cells through various methods has further expanded their utility in research and industrial applications.

It is important to note that while CHO cells are widely used in scientific research, they may not always accurately represent human cell behavior or respond to drugs and other compounds in the same way as human cells do. Therefore, results obtained using CHO cells should be validated in more relevant systems when possible.

Actin is a type of protein that forms part of the contractile apparatus in muscle cells, and is also found in various other cell types. It is a globular protein that polymerizes to form long filaments, which are important for many cellular processes such as cell division, cell motility, and the maintenance of cell shape. In muscle cells, actin filaments interact with another type of protein called myosin to enable muscle contraction. Actins can be further divided into different subtypes, including alpha-actin, beta-actin, and gamma-actin, which have distinct functions and expression patterns in the body.

Alpha-synuclein is a protein that is primarily found in neurons (nerve cells) in the brain. It is encoded by the SNCA gene and is abundantly expressed in presynaptic terminals, where it is believed to play a role in the regulation of neurotransmitter release.

In certain neurological disorders, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, alpha-synuclein can form aggregates known as Lewy bodies and Lewy neurites. These aggregates are a pathological hallmark of these diseases and are believed to contribute to the death of nerve cells, leading to the symptoms associated with these disorders.

The precise function of alpha-synuclein is not fully understood, but it is thought to be involved in various cellular processes such as maintaining the structure of the presynaptic terminal, regulating synaptic vesicle trafficking and neurotransmitter release, and protecting neurons from stress.

Bleeding time is a medical test that measures the time it takes for a small blood vessel to stop bleeding after being cut. It's used to evaluate platelet function and the effectiveness of blood clotting. The most common method used to measure bleeding time is the Ivy method, which involves making a standardized incision on the forearm and measuring the time it takes for the bleeding to stop. A normal bleeding time ranges from 2 to 9 minutes, but this can vary depending on the specific method used. Prolonged bleeding time may indicate an impairment in platelet function or clotting factor deficiency.

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.

Thrombin is a serine protease enzyme that plays a crucial role in the coagulation cascade, which is a complex series of biochemical reactions that leads to the formation of a blood clot (thrombus) to prevent excessive bleeding during an injury. Thrombin is formed from its precursor protein, prothrombin, through a process called activation, which involves cleavage by another enzyme called factor Xa.

Once activated, thrombin converts fibrinogen, a soluble plasma protein, into fibrin, an insoluble protein that forms the structural framework of a blood clot. Thrombin also activates other components of the coagulation cascade, such as factor XIII, which crosslinks and stabilizes the fibrin network, and platelets, which contribute to the formation and growth of the clot.

Thrombin has several regulatory mechanisms that control its activity, including feedback inhibition by antithrombin III, a plasma protein that inactivates thrombin and other serine proteases, and tissue factor pathway inhibitor (TFPI), which inhibits the activation of factor Xa, thereby preventing further thrombin formation.

Overall, thrombin is an essential enzyme in hemostasis, the process that maintains the balance between bleeding and clotting in the body. However, excessive or uncontrolled thrombin activity can lead to pathological conditions such as thrombosis, atherosclerosis, and disseminated intravascular coagulation (DIC).

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Lectins are a type of proteins that bind specifically to carbohydrates and have been found in various plant and animal sources. They play important roles in biological recognition events, such as cell-cell adhesion, and can also be involved in the immune response. Some lectins can agglutinate certain types of cells or precipitate glycoproteins, while others may have a more direct effect on cellular processes. In some cases, lectins from plants can cause adverse effects in humans if ingested, such as digestive discomfort or allergic reactions.

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.

Integrins are a type of cell-adhesion molecule that play a crucial role in cell-cell and cell-extracellular matrix (ECM) interactions. They are heterodimeric transmembrane receptors composed of non-covalently associated α and β subunits, which form more than 24 distinct integrin heterodimers in humans.

Integrins bind to specific ligands, such as ECM proteins (e.g., collagen, fibronectin, laminin), cell surface molecules, and soluble factors, through their extracellular domains. The intracellular domains of integrins interact with the cytoskeleton and various signaling proteins, allowing them to transduce signals from the ECM into the cell (outside-in signaling) and vice versa (inside-out signaling).

These molecular interactions are essential for numerous biological processes, including cell adhesion, migration, proliferation, differentiation, survival, and angiogenesis. Dysregulation of integrin function has been implicated in various pathological conditions, such as cancer, fibrosis, inflammation, and autoimmune diseases.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

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.

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.

Cytoskeletal proteins are a type of structural proteins that form the cytoskeleton, which is the internal framework of cells. The cytoskeleton provides shape, support, and structure to the cell, and plays important roles in cell division, intracellular transport, and maintenance of cell shape and integrity.

There are three main types of cytoskeletal proteins: actin filaments, intermediate filaments, and microtubules. Actin filaments are thin, rod-like structures that are involved in muscle contraction, cell motility, and cell division. Intermediate filaments are thicker than actin filaments and provide structural support to the cell. Microtubules are hollow tubes that are involved in intracellular transport, cell division, and maintenance of cell shape.

Cytoskeletal proteins are composed of different subunits that polymerize to form filamentous structures. These proteins can be dynamically assembled and disassembled, allowing cells to change their shape and move. Mutations in cytoskeletal proteins have been linked to various human diseases, including cancer, neurological disorders, and muscular dystrophies.

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.

Thromboxane A2 (TXA2) is a potent prostanoid, a type of lipid compound derived from arachidonic acid. It is primarily produced and released by platelets upon activation during the process of hemostasis (the body's response to stop bleeding). TXA2 acts as a powerful vasoconstrictor, causing blood vessels to narrow, which helps limit blood loss at the site of injury. Additionally, it promotes platelet aggregation, contributing to the formation of a stable clot and preventing further bleeding. However, uncontrolled or excessive production of TXA2 can lead to thrombotic events such as heart attacks and strokes. Its effects are balanced by prostacyclin (PGI2), which is produced by endothelial cells and has opposing actions, acting as a vasodilator and inhibiting platelet aggregation. The balance between TXA2 and PGI2 helps maintain vascular homeostasis.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

Platelet membrane glycoproteins are specialized proteins found on the surface of platelets, which are small blood cells responsible for clotting. These glycoproteins play crucial roles in various processes related to hemostasis and thrombosis, including platelet adhesion, activation, and aggregation.

There are several key platelet membrane glycoproteins, such as:

1. Glycoprotein (GP) Ia/IIa (also known as integrin α2β1): This glycoprotein mediates the binding of platelets to collagen fibers in the extracellular matrix, facilitating platelet adhesion and activation.
2. GP IIb/IIIa (also known as integrin αIIbβ3): This is the most abundant glycoprotein on the platelet surface and functions as a receptor for fibrinogen, von Willebrand factor, and other adhesive proteins. Upon activation, GP IIb/IIIa undergoes conformational changes that enable it to bind these ligands, leading to platelet aggregation and clot formation.
3. GPIb-IX-V: This glycoprotein complex is involved in the initial tethering and adhesion of platelets to von Willebrand factor (vWF) in damaged blood vessels. It consists of four subunits: GPIbα, GPIbβ, GPIX, and GPV.
4. GPVI: This glycoprotein is essential for platelet activation upon contact with collagen. It associates with the Fc receptor γ-chain (FcRγ) to form a signaling complex that triggers intracellular signaling pathways, leading to platelet activation and aggregation.

Abnormalities in these platelet membrane glycoproteins can lead to bleeding disorders or thrombotic conditions. For example, mutations in GPIIb/IIIa can result in Glanzmann's thrombasthenia, a severe bleeding disorder characterized by impaired platelet aggregation. On the other hand, increased expression or activation of these glycoproteins may contribute to the development of arterial thrombosis and cardiovascular diseases.

Protein denaturation is a process in which the native structure of a protein is altered, leading to loss of its biological activity. This can be caused by various factors such as changes in temperature, pH, or exposure to chemicals or radiation. The three-dimensional shape of a protein is crucial for its function, and denaturation causes the protein to lose this shape, resulting in impaired or complete loss of function. Denaturation is often irreversible and can lead to the aggregation of proteins, which can have negative effects on cellular function and can contribute to diseases such as Alzheimer's and Parkinson's.

Antibodies are proteins produced by the immune system in response to the presence of a foreign substance, such as a bacterium or virus. They are capable of identifying and binding to specific antigens (foreign substances) on the surface of these invaders, marking them for destruction by other immune cells. Antibodies are also known as immunoglobulins and come in several different types, including IgA, IgD, IgE, IgG, and IgM, each with a unique function in the immune response. They are composed of four polypeptide chains, two heavy chains and two light chains, that are held together by disulfide bonds. The variable regions of the heavy and light chains form the antigen-binding site, which is specific to a particular antigen.

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.

Gene expression regulation in bacteria refers to the complex cellular processes that control the production of proteins from specific genes. This regulation allows bacteria to adapt to changing environmental conditions and ensure the appropriate amount of protein is produced at the right time.

Bacteria have a variety of mechanisms for regulating gene expression, including:

1. Operon structure: Many bacterial genes are organized into operons, which are clusters of genes that are transcribed together as a single mRNA molecule. The expression of these genes can be coordinately regulated by controlling the transcription of the entire operon.
2. Promoter regulation: Transcription is initiated at promoter regions upstream of the gene or operon. Bacteria have regulatory proteins called sigma factors that bind to the promoter and recruit RNA polymerase, the enzyme responsible for transcribing DNA into RNA. The binding of sigma factors can be influenced by environmental signals, allowing for regulation of transcription.
3. Attenuation: Some operons have regulatory regions called attenuators that control transcription termination. These regions contain hairpin structures that can form in the mRNA and cause transcription to stop prematurely. The formation of these hairpins is influenced by the concentration of specific metabolites, allowing for regulation of gene expression based on the availability of those metabolites.
4. Riboswitches: Some bacterial mRNAs contain regulatory elements called riboswitches that bind small molecules directly. When a small molecule binds to the riboswitch, it changes conformation and affects transcription or translation of the associated gene.
5. CRISPR-Cas systems: Bacteria use CRISPR-Cas systems for adaptive immunity against viruses and plasmids. These systems incorporate short sequences from foreign DNA into their own genome, which can then be used to recognize and cleave similar sequences in invading genetic elements.

Overall, gene expression regulation in bacteria is a complex process that allows them to respond quickly and efficiently to changing environmental conditions. Understanding these regulatory mechanisms can provide insights into bacterial physiology and help inform strategies for controlling bacterial growth and behavior.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

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.

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

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

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

Surface antigens are molecules found on the surface of cells that can be recognized by the immune system as being foreign or different from the host's own cells. Antigens are typically proteins or polysaccharides that are capable of stimulating an immune response, leading to the production of antibodies and activation of immune cells such as T-cells.

Surface antigens are important in the context of infectious diseases because they allow the immune system to identify and target infected cells for destruction. For example, viruses and bacteria often display surface antigens that are distinct from those found on host cells, allowing the immune system to recognize and attack them. In some cases, these surface antigens can also be used as targets for vaccines or other immunotherapies.

In addition to their role in infectious diseases, surface antigens are also important in the context of cancer. Tumor cells often display abnormal surface antigens that differ from those found on normal cells, allowing the immune system to potentially recognize and attack them. However, tumors can also develop mechanisms to evade the immune system, making it difficult to mount an effective response.

Overall, understanding the properties and behavior of surface antigens is crucial for developing effective immunotherapies and vaccines against infectious diseases and cancer.

Membrane glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. They are integral components of biological membranes, spanning the lipid bilayer and playing crucial roles in various cellular processes.

The glycosylation of these proteins occurs in the endoplasmic reticulum (ER) and Golgi apparatus during protein folding and trafficking. The attached glycans can vary in structure, length, and composition, which contributes to the diversity of membrane glycoproteins.

Membrane glycoproteins can be classified into two main types based on their orientation within the lipid bilayer:

1. Type I (N-linked): These glycoproteins have a single transmembrane domain and an extracellular N-terminus, where the oligosaccharides are predominantly attached via asparagine residues (Asn-X-Ser/Thr sequon).
2. Type II (C-linked): These glycoproteins possess two transmembrane domains and an intracellular C-terminus, with the oligosaccharides linked to tryptophan residues via a mannose moiety.

Membrane glycoproteins are involved in various cellular functions, such as:

* Cell adhesion and recognition
* Receptor-mediated signal transduction
* Enzymatic catalysis
* Transport of molecules across membranes
* Cell-cell communication
* Immunological responses

Some examples of membrane glycoproteins include cell surface receptors (e.g., growth factor receptors, cytokine receptors), adhesion molecules (e.g., integrins, cadherins), and transporters (e.g., ion channels, ABC transporters).

Thromboxane B2 (TXB2) is a stable metabolite of thromboxane A2 (TXA2), which is a potent vasoconstrictor and platelet aggregator synthesized by activated platelets. TXA2 has a very short half-life, quickly undergoing spontaneous conversion to the more stable TXB2.

TXB2 itself does not have significant biological activity but serves as a marker for TXA2 production in various physiological and pathophysiological conditions, such as thrombosis, inflammation, and atherosclerosis. It can be measured in blood or other bodily fluids to assess platelet activation and the status of hemostatic and inflammatory processes.

Protein multimerization refers to the process where multiple protein subunits assemble together to form a complex, repetitive structure called a multimer or oligomer. This can involve the association of identical or similar protein subunits through non-covalent interactions such as hydrogen bonding, ionic bonding, and van der Waals forces. The resulting multimeric structures can have various shapes, sizes, and functions, including enzymatic activity, transport, or structural support. Protein multimerization plays a crucial role in many biological processes and is often necessary for the proper functioning of proteins within cells.

Platelet function tests are laboratory tests that measure how well platelets, which are small blood cells responsible for clotting, function in preventing or stopping bleeding. These tests are often used to investigate the cause of abnormal bleeding or bruising, or to monitor the effectiveness of antiplatelet therapy in patients with certain medical conditions such as heart disease or stroke.

There are several types of platelet function tests available, including:

1. Platelet count: This test measures the number of platelets present in a sample of blood. A low platelet count can increase the risk of bleeding.
2. Bleeding time: This test measures how long it takes for a small cut to stop bleeding. It is used less frequently than other tests due to its invasiveness and variability.
3. Platelet aggregation tests: These tests measure how well platelets clump together (aggregate) in response to various agents that promote platelet activation, such as adenosine diphosphate (ADP), collagen, or epinephrine.
4. Platelet function analyzer (PFA): This test measures the time it takes for a blood sample to clot under shear stress, simulating the conditions in an injured blood vessel. The PFA can provide information about the overall platelet function and the effectiveness of antiplatelet therapy.
5. Thromboelastography (TEG) or rotational thromboelastometry (ROTEM): These tests measure the kinetics of clot formation, strength, and dissolution in whole blood samples. They provide information about both platelet function and coagulation factors.

These tests can help healthcare providers diagnose bleeding disorders, assess the risk of bleeding during surgery or other invasive procedures, monitor antiplatelet therapy, and guide treatment decisions for patients with abnormal platelet function.

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

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

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

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.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

Amyloid beta-peptides (Aβ) are small protein fragments that are crucially involved in the pathogenesis of Alzheimer's disease. They are derived from a larger transmembrane protein called the amyloid precursor protein (APP) through a series of proteolytic cleavage events.

The two primary forms of Aβ peptides are Aβ40 and Aβ42, which differ in length by two amino acids. While both forms can be harmful, Aβ42 is more prone to aggregation and is considered to be the more pathogenic form. These peptides have the tendency to misfold and accumulate into oligomers, fibrils, and eventually insoluble plaques that deposit in various areas of the brain, most notably the cerebral cortex and hippocampus.

The accumulation of Aβ peptides is believed to initiate a cascade of events leading to neuroinflammation, oxidative stress, synaptic dysfunction, and neuronal death, which are all hallmarks of Alzheimer's disease. Although the exact role of Aβ in the onset and progression of Alzheimer's is still under investigation, it is widely accepted that they play a central part in the development of this debilitating neurodegenerative disorder.

Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.

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.

Molecular chaperones are a group of proteins that assist in the proper folding and assembly of other protein molecules, helping them achieve their native conformation. They play a crucial role in preventing protein misfolding and aggregation, which can lead to the formation of toxic species associated with various neurodegenerative diseases. Molecular chaperones are also involved in protein transport across membranes, degradation of misfolded proteins, and protection of cells under stress conditions. Their function is generally non-catalytic and ATP-dependent, and they often interact with their client proteins in a transient manner.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

However, as cells age, these control mechanisms are weakened and the cell is less able to resolve the aggregates. The ... In mammalian cells, these protein aggregates are termed "aggresomes" and they are formed when the cell is diseased. This is ... The aggregates in bacteria asymmetrically end up at one of the poles of the cell, the "older pole." After the cell divides, the ... "Cellular strategies for controlling protein aggregation". Nature Reviews Molecular Cell Biology. 11 (11): 777-788. doi:10.1038/ ...
... is the reversible clumping of red blood cells (RBCs) under low shear forces or at stasis. Erythrocytes ... Cabel M, Meiselman HJ, Popel AS, Johnson PC (1997). "Contribution of red blood cell aggregation to venous vascular resistance ... Mesielman HJ (1993). "Red blood cell role in RBC aggregation: 1963-1993 and beyond". Clinical Hemorheology. 13: 575-592. Neu B ... Meiselman HJ (2009). "Red blood cell aggregation: 45 years being curious". Biorheology. 46 (1): 1-19. doi:10.3233/BIR-2009-0522 ...
... is also called Dual Cell in the context of UMTS/HSPA+. Through carrier aggregation (part of the UMTS ... Release 10 supports four-carrier aggregation and eight-carrier-aggregation is supported since Release 11. 3GPP standardized ... The sum data rate of a cell is increased as well because of a better resource utilization. In addition, load balancing: p.42 is ... If the component carriers are in the same frequency band but are separated by a gap the carrier aggregation is called intra- ...
It shows that by using bearer split LWA improves the average as well as the cell edge user perceived throughput across all ... LTE-WLAN aggregation (LWA) is a technology defined by the 3GPP. In LWA, a mobile handset supporting both LTE and Wi-Fi may be ... In LTE - WLAN Aggregation (eg. LWA or LWIP) the WLAN access is directly connected to RAN access nodes and the access selection ... It is not clear though how much improvement LWA may bring when it is compared with other RAN based LTE-WLAN Aggregation ...
These trees can also be grown easily in an electrodeposition cell, and are the direct result of diffusion-limited aggregation. ... Media related to Diffusion-limited aggregation at Wikimedia Commons JavaScript based DLA Diffusion-Limited Aggregation: A Model ... Diffusion-limited aggregation (DLA) is the process whereby particles undergoing a random walk due to Brownian motion cluster ... and L.M. Sander in 1981, is applicable to aggregation in any system where diffusion is the primary means of transport in the ...
"Platelet phagocytosis and aggregation". The Journal of Cell Biology. 27 (3): 531-543. doi:10.1083/jcb.27.3.531. PMC 2106759. ... Berridge, Michael J. (1 October 2014). "Module 11: Cell Stress, Inflammatory Responses and Cell Death" (PDF). Cell Signalling ... "Programmed anuclear cell death delimits platelet life span". Cell. 128 (6): 1173-1186. doi:10.1016/j.cell.2007.01.037. PMID ... Endothelial cells are attached to the subendothelial collagen by von Willebrand factor (VWF), which these cells produce. VWF is ...
"Ataxin-1 nuclear localization and aggregation: role in polyglutamine-induced disease in SCA1 transgenic mice". Cell. 95 (1): 41 ... Cell. 127 (7): 1335-47. doi:10.1016/j.cell.2006.11.038. PMID 17190598. S2CID 14900395. Kim E, Lee Y, Choi S, Song JJ (July 2014 ... Cell. 122 (4): 633-44. doi:10.1016/j.cell.2005.06.012. PMID 16122429. S2CID 16706329. Mizutani A, Wang L, Rajan H, Vig PJ, ... This led to the hypothesis that the aggregates are toxic to neurons, but it has been shown in mice that aggregation is not ...
In animal cells, virus particles are gathered by the microtubule-dependent aggregation of toxic or misfolded protein near the ... Viroplasms also control release of virions when the insect stings an infected plant cell or a cell near the infected cells. ... Understanding the phenomena of virus aggregation and of the cell response to the presence of virus, and whether viroplasms ... Kopito RR (December 2000). "Aggresomes, inclusion bodies and protein aggregation". Trends in Cell Biology. 10 (12): 524-30. doi ...
Bicher, Haim (1972). Blood Cell Aggregation in Thrombotic Processes. Springfield: Charles C. Thomas. ISBN 9780398022327. " ...
These kinds of chimeras can be made through either aggregation of stem cells and the diploid embryo or injection of the stem ... ES cells from the inner cell mass of an implanted blastocyst can contribute to all cell lineages of a mouse including the germ ... ES cells can be used in combination with eight-cell-and two-cell-stage embryos to make chimeras and exclusively give rise to ... They were created by mixing cells from totipotent four-cell morulas; although the cells never fused, they worked together to ...
Protein aggregation Protein folding Live cell imaging Jennifer Lippincott-Schwartz : Intracellular Fluorescent Imaging: An ... "Live Cell Imaging". Live cell imaging enables in vivo tracking of proteins in space and time, in their natural endogenous ... which can then be followed inside a cell using a fluorescence microscope. The cell may then be treated by a perturbation of ... "Live-Cell Imaging". Lippincott-Schwartz, J.; Patterson, GH (2003). "Development and Use of Fluorescent Protein Markers in ...
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In addition, PGE2 inhibits platelet aggregation. PGE2 also suppresses T cell receptor signaling and proliferation, and may play ... PGE2 also has roles in inhibition of cytotoxic T-cell function, cell division of T-lymphocytes, and the development of TH1 ... "A live imaging cell motility screen identifies prostaglandin E2 as a T cell stop signal antagonist". Journal of Immunology. 187 ... Torres R, Picado C, de Mora F (January 2015). "The PGE2-EP2-mast cell axis: an antiasthma mechanism". Molecular Immunology. 63 ...
"Strong aggregation and increased toxicity of polyleucine over polyglutamine stretches in mammalian cells". Human Molecular ... They may play a structural role in proteins such as collagens, myosin, keratins, silk, cell wall proteins. Tandem repeats of ... They thus hypothesize and propose that, in a cell-free environment, the early genetic code may have also produced low ... Thus, their presence may disturb the balance of protein-protein interaction networks within the cell, especially if the carrier ...
... and was simulated on a computer for clusters up to about 32,000 cells. By the mid-1980s, clusters with a billion cells had been ... Diffusion-limited aggregation Barabasi, Albert-Laszlo; Stanley, Harry Eugene (1995). Fractal Concepts in Surface Growth. ...
Cell lysis is a convenient tool to isolate certain macromolecules that exist primarily inside of the cell. Cell membranes ... At 303 K (30 °C) it forms micelles with aggregation number 75-120 (depending on method of determination; average ~95) and ... Other toxicity tests have been conducted using incubated human skin HaCaT keratinocyte cells. These human cells were incubated ... The human cells show CTAB being nontoxic at concentrations less than 1 μM. Without the use of CTAB in this synthesis, the gold ...
... and colocalization in cultured cells". In Vitro Cell. Dev. Biol. Anim. 38 (10): 582-94. doi:10.1290/1543-706X(2002)38. 2.0.CO;2 ... Moss TN, Vo A, McKeehan WL, Liu L (2007). "UXT (Ubiquitously Expressed Transcript) causes mitochondrial aggregation". In Vitro ... and regulated expression in prostate cancer cells results in decreased cell proliferation. Significantly, because decreased ... Cell. 13 (2): 670-82. doi:10.1091/mbc.01-10-0513. PMC 65658. PMID 11854421. Nwachukwu JC, Li W, Pineda-Torra I, Huang HY, Ruoff ...
Dobson CM (February 2004). "Principles of protein folding, misfolding and aggregation". Seminars in Cell & Developmental ... Auxiliary factors inside the living cell such as folding catalysts and chaperones assist in the folding process but do not ... that a protein's native state corresponds to its free energy minimum under the solution conditions usually encountered in cells ...
... normally aids in protein folding and aggregation; when present in the cell, functioning as an anti-inflammatory molecule ... Similarly, Hsp70 overexpression suppressed poly-Q dependent aggregation and neurodegeneration in cell cultures, yeast, fly, and ... Given the role of heat shock proteins as an ancient defense system for stabilizing cells and eliminating old and damaged cells ... Hsp70 is overexpressed in malignant melanoma and underexpressed in renal cell cancer. In breast cancer cell line (MCF7) has ...
The classic taxonomic criterion has been the cell morphology and the plane of cell division. In Pleurocapsales, the cells have ... Aggregation must divert resources away from the core business of making more cyanobacteria, as it generally involves the ... The cells in a hormogonium are often thinner than in the vegetative state, and the cells on either end of the motile chain may ... Each individual cell (each single cyanobacterium) typically has a thick, gelatinous cell wall. They lack flagella, but ...
Cholesterol uptake by cells instigates inflammation, affecting both the central nervous system and the peripheral systems. This ... phenomenon involves the aggregation of inflammatory proteins. For instance, in the context of TLR4, cholesterol prompts ... Jefcoate, CR; Lee, J (May 2018). "Cholesterol signaling in single cells: lessons from STAR and sm-FISH". Journal of Molecular ... Cholesterol is a signaling molecule that is highly regulated in eukaryotic cell membranes. In human health, its effects are ...
Wang, Michelle Dong (1993). Reaction and aggregation dynamics of cell surface receptors. OCLC 713128957. "Michelle D. Wang". ... including RNA polymerase molecules which move along the DNA template during cell division. During this process genetic ...
Initial cell spreading on the abductin-based protein was similar to that on bovine serum albumin. These studies thus ... A moderate increase in DH was observed from 35 °C, and a sharper increase in DH occurred starting at 57 °C (aggregation ... A LIVE/DEAD assay revealed that human umbilical vein endothelial cells had a viability of 98 ± 4% after being cultured for two ... The abductin-based protein was cytocompatible, and cells spread slowly when first seeded on the abductin-based protein. ...
... with Fc epsilon RI gamma 2 subunits in U937 cells. Aggregation induces the tyrosine phosphorylation of gamma 2". Journal of ... FcαRI is present on the cell surface of myeloid lineage cells, including neutrophils, monocytes, macrophages, and eosinophils, ... FcαRI is also an important Fc receptor for neutrophil killing of tumor cells. When FcαRI-expressing neutrophils come into ... van Egmond M, Bakema JE (June 2013). "Neutrophils as effector cells for antibody-based immunotherapy of cancer". Seminars in ...
These byproducts can react with cellular proteins to cause misfolding and aggregation (especially in nondividing cells like ... The unregulated cell division that marks cancer development requires increased protein synthesis for cancer cell function and ... This can change the sensitivity of cancer cells to antineoplastic drugs; cancer cells either die at a lower drug concentration ... This increased protein synthesis is typically seen in proteins that modulate cell metabolism and growth processes. Cancer cells ...
found that CB causes multinucleation in cells and significantly affects cell motility. The multinucleated cells probably arise ... Cytochalasin B inhibits glucose transport and platelet aggregation. It blocks adenosine-induced apoptotic body formation ... Cells treated with cytochalasin B and control group cells could not be distinguished. This indicated, that CB has no ... These are small nuclei containing one chromosome or part of a chromosome which did not get to one of the cell poles during cell ...
Cells expressing the protein showed cell aggregation activity. Alternative splicing occurs in this gene. GRCh38: Ensembl ... The encoded protein is a membrane protein found at cell-cell boundaries. It is involved in neural cell adhesion, suggesting a ... Cell. Proteomics. 3 (11): 1093-101. doi:10.1074/mcp.M400085-MCP200. PMID 15345747. S2CID 18659460. Rush J, Moritz A, Lee KA, et ... 2005). "Immunoaffinity profiling of tyrosine phosphorylation in cancer cells". Nat. Biotechnol. 23 (1): 94-101. doi:10.1038/ ...
There are about 24,000 oxidative DNA adducts per cell in young rats and 66,000 adducts per cell in old rats. Likewise, any ... Excessive oxidative-damage leads to protein degradation or aggregation. The reaction of transition metals with proteins ... Reactive oxygen species can disrupt the function of immune cells, promoting immune evasion of leukemic cells. On the other hand ... In neuronal progenitor cells, DNA damage is associated with increased secretion of amyloid beta proteins Aβ40 and Aβ42. This ...
"Widespread Proteome Remodeling and Aggregation in Aging C. elegans". Cell. 161 (4): 919-32. doi:10.1016/j.cell.2015.03.032. PMC ... Cell Stem Cell. 29: 918-932, doi: 10.1016/j.stem.2022.04.018 (2022). Morimoto, R.I., and G.S. Budinger. Protein Folding ... Krammer, C.; Park, K.W.; Li, L.; Melki, R.; Morimoto, R.I. (2013). "Spreading of a Prion Domain from Cell to Cell by Vesicular ... Rethinking the Roles of HSF-1 in Cell Stress, Development and Organismal Health. Trends in Cell Biology 12: DOI: org/10.1016/ j ...
In eukaryotic cells, an aggresome refers to an aggregation of misfolded proteins in the cell, formed when the protein ... An aggresome forms around the microtubule organizing center in eukaryotic cells, adjacent to or enveloping the cell's ... Overexpression or inhibition of proteasome activity in transfected human embryonic kidney cells or Chinese hamster ovary cells ... molecules leading to their aggregation and deposition in aggresomes. Aggresome formation is a general response of cells which ...
Evolution of molecular aggregation in bar-coated non-fullerene organic solar cells Y. Mao, W. Li, M. Chen, X. Chen, R. S. ... Evolution of molecular aggregation in bar-coated non-fullerene organic solar cells† ... Stage II (total volume fraction between 20 and 40%) reveals the onset of slow aggregation of PBDB-T and ITIC. Stage III (total ... Four distinct stages can be defined in the evolution of the extinction coefficient (k) according to the aggregation behavior of ...
4, The late-born cells (magenta) are migrating over the cell bodies of the GFP-positive cells. 5, Nonlabeled late-born cells ( ... Neuro2a cells were then collected with a cell scraper and centrifuged, and the cell pellets were lysed in a cell lysis buffer ... 3 B′,C′,D′) in the clusters of 293T cells. These cell-body-sparse regions were accompanied by densely packed neuronal cell ... F , I , The average relative distances of GFP-positive cells, BrdU-labeled cells, and IdU-labeled cells (blue single-positive ...
However, as cells age, these control mechanisms are weakened and the cell is less able to resolve the aggregates. The ... In mammalian cells, these protein aggregates are termed "aggresomes" and they are formed when the cell is diseased. This is ... The aggregates in bacteria asymmetrically end up at one of the poles of the cell, the "older pole." After the cell divides, the ... "Cellular strategies for controlling protein aggregation". Nature Reviews Molecular Cell Biology. 11 (11): 777-788. doi:10.1038/ ...
It has long been assumed that platelet aggregation and thrombus growth are initiated by soluble agonists generated at sites of ... By using high-resolution intravital imaging techniques and hydrodynamic analyses, we show that platelet aggregation is ... Platelet aggregation at sites of vascular injury is essential for hemostasis and arterial thrombosis. ... of disturbed blood flow parameters and suggest a fundamental reinterpretation of the mechanisms driving platelet aggregation ...
Microaggregation appeared to be distinct from full aggregation, as it was not inhibited by the addition of CD61, an antibody to ... These results indicate that platelet shape change is not a prerequisite for aggregation and that the signal widely believed to ... We conclude that platelet aggregation occurs independently of shape change and that shape change is not necessarily followed by ... it is widely held that platelet shape change is a prerequisite for platelet aggregation. We conducted this study to determine ...
Aggregation and Toxicities - A Special Issue published by Hindawi ... Cell Surface Binding and Internalization of Aβ Modulated by ... Aggregation and deposition of amyloid β-protein (Aβ) in brain is an invariable and initial event in the pathological process of ... Aβ aggregation/oligomerization on neuronal membranes (lipid rafts). *Aβ toxicities on neuronal or intraneuronal membranes/ ... Recently, a body of evidence is growing that Aβ aggregation is facilitated in the presence of particular membranes lipids such ...
Hey, Im Talkin Here: New York Subway Succumbs To Cell Phones. Jolie ODell / VentureBeat:. New York City subways to get cell ... Some New York City subways get cell service September 27. Todd Wasserman / Mashable!:. Cell Phone Service Finally Comes to New ... Business Insider, Over-Aggregation, and the Mad Grab for Traffic. Henry Blodget / Business Insider:. A Huge Thank-You To IVP ... Cell service on subway platforms to begin Tuesday, MTA confirms. Sam Biddle / Gizmodo:. Cellphone Service Hitting NYC Subways ...
Broadband Access Aggregation and DSL Configuration Guide, Cisco IOS Release 15M&T -1-Port ADSL WAN Interface Card for Cisco ... cells. Fixed-length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is designed to take ... Understanding Broadband Access Aggregation. *Providing Protocol Support for Broadband Access Aggregation of PPP over ATM ... International standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in fixed- ...
The aggregation and fusion of negatively charged LUV are peptide concentration-dependent until massive aggregation is reached, ... LPS aggregation can be related with a decreased toxicity, possibly by facilitating its clearance by macrophage phagocytosis and ... Using dynamic light scattering spectroscopy we demonstrate that rBPI21 promotes aggregation of negatively charged large ... Cell membranes Is the Subject Area "Cell membranes" applicable to this article? Yes. No. ...
1996]: Cell 85: 513-523; Gautam et al. [1996]: Cell 85: 525-535). Although the agrin/MuSK signaling pathway remains l … ... initiates postsynaptic development on skeletal muscle that includes the aggregation of acetylcholine receptors (AChRs; Glass et ... 1996]: Cell 85: 513-523; Gautam et al. [1996]: Cell 85: 525-535). Although the agrin/MuSK signaling pathway remains largely ... are required for full agrin-induced aggregation of AChRs and sufficient to induce agrin-independent AChR aggregation. Blockade ...
Infinera Expands Open Networking Solutions with Telecom Infra Project-compliant Disaggregated Cell Site Gateway. ... Access and aggregation networks are facing relentless pressure to cost-effectively expand capacity to meet the ever-rising ... Meet the demanding capacity and performance demands of access and aggregation networks with point-to-multipoint coherent optics ... our portfolio is changing the way network operators deliver services and scale capacity in their access and aggregation ...
Carrier aggregation is also called Dual Cell in the context of UMTS/HSPA+. Through carrier aggregation (part of the UMTS ... Release 10 supports four-carrier aggregation and eight-carrier-aggregation is supported since Release 11. 3GPP standardized ... The sum data rate of a cell is increased as well because of a better resource utilization. In addition, load balancing: p.42 is ... If the component carriers are in the same frequency band but are separated by a gap the carrier aggregation is called intra- ...
... aggregation is linked to a decreased cell fitness due to inactivation of protein function. Our study shows that aggregation is ... aggregation is linked to a decreased cell fitness due to inactivation of protein function.Our study shows that aggregation is ... Specifically, aggregation was found to be associated with increased cell fitness in the case of TDP-43 mutations, as it ... Specifically, aggregation was found to be associated with increased cell fitness in the case of TDP-43 mutations, as it ...
The bacterial amyloids phenol soluble modulins from Staphylococcus aureus catalyze alpha-synuclein aggregation. Caroline Haikal ... The bacterial amyloids phenol soluble modulins from Staphylococcus aureus catalyze alpha-synuclein aggregation ... The bacterial amyloids phenol soluble modulins from Staphylococcus aureus catalyze alpha-synuclein aggregation ... The bacterial amyloids phenol soluble modulins from Staphylococcus aureus catalyze alpha-synuclein aggregation ...
Tumor necrosis factor-α and CD40L modulate cell surface morphology and induce aggregation in Ramos Burkitts lymphoma cells. ... Tumor necrosis factor-α and CD40L modulate cell surface morphology and induce aggregation in Ramos Burkitts lymphoma cells. ...
Journal Article] Amphiphilic Polysaccharide Nanogels as Artificial Chaperones in Cell-Free Protein Synthesis.2011. *. Author(s) ... 800 aggregation-prone cytosolic proteins. The results revealed that many of the~ 800 aggregation-prone proteins were ... Comprehensive analysis of aggregation-inhibition effects of three major molecular chaperones working in Escherichia coli was ... Journal Article] Amphiphilic Polysaccharide Nanogels as Artificial Chaperones in Cell-Free Protein Synthesis2011. *. Author(s) ...
... and the degree of aggregation observed after a 3-min time period was expressed as a percentage of the maximum aggregation ... Cells loaded with fluo-3 were then resuspended to yield a stock suspension of about 6 × 106 cells/ml in a buffer, pH 7.4, of ... In contrast with Met-OH, tc-fF-NH2 on its own activated a calcium signal in the HEK cells and was able to diminish the HEK cell ... Cell suspensions (about 2 ml at a concentration of approximately 3 × 105 cells/ml) were maintained in suspension in a stirred ( ...
Spaceflight enhances cell aggregation and random budding in Candida albicans. PloS one. 2013 Dec 4;8(12):e80677. doi: 10.1371/ ... Spaceflight enhances cell aggregation and random budding in Candida albicans. In: PloS one. 2013 ; Vol. 8, No. 12. ... Spaceflight enhances cell aggregation and random budding in Candida albicans. Aurélie Crabbé, Sheila M. Nielsen-Preiss, ... Spaceflight enhances cell aggregation and random budding in Candida albicans. / Crabbé, Aurélie; Nielsen-Preiss, Sheila M.; ...
Aggregation and Rescues Living Mammalian Cells from IAPP Toxicity ... Aggregation and Rescues Living Mammalian Cells from IAPP ... Substances that prevent or slow IAPP aggregation allow the EGFP protein to fold and fluoresce. E. coli cells were induced with ... 5). The PC12 cells were cultured in 5% CO2 at 37º C in F-12K media (ATCC) supplemented with 10% FBS (ATCC). The cells were ... IAPP at 10μM was toxic to the cells and reduced the MTT signal to 71% compared to cells untreated with IAPP. At a 1 to 1 ratio ...
Preparation and reversible aggregation of human cells encased in biocompatible polysaccharide shell ... HeLa cells. We developed an approach to controllable and. reversible aggregation of modified cells by their cross-linking. in ... Preparation and reversible aggregation of human cells encased in biocompatible polysaccharide shell. ... Home , Archives , Vol 7, No 3 (2012) , Preparation and reversible aggregation of human cells encased in biocompatible ...
Huang, GS, Hu, MH, Lin, TC, Tsai, CS, Lee, CH & Liaw, WJ 2009, Cilostazol inhibits platelet-monocytic THP1 cell aggregation, ... Cilostazol inhibits platelet-monocytic THP1 cell aggregation, platelet CD4OL, and P-selectin expression. In: Journal of Medical ... The blood samples were stimulated by adenosine diphosphate (8 μ M) for evaluation of platelet-monocytic THP1 cell aggregation ... Cilostazol inhibits platelet-monocytic THP1 cell aggregation, platelet CD4OL, and P-selectin expression. / Huang, Go Shine; Hu ...
From cell-cell aggregation assay, SK-LMS-1 parental and Sh-Control cells formed more and larger cell-cell aggregates than Sh- ... From cell-cell aggregation assay, SK-LMS-1 parental and Sh-Control cells formed more and larger cell-cell aggregates than Sh- ... Cell-cell aggregation assay. Cells (1 × 105) were seeded on a 35-mm dish without coating, cultured for 24 h, and digitized by ... Cell-cell aggregation assay. Cells (1 × 105) were seeded on a 35-mm dish without coating, cultured for 24 h, and digitized by ...
The deformability of the cells is decreased. A combination of these alterations in erythrocyte deformability and aggregation ... Abstract: Aggregation process of erythrocytes in mammals is determined. This process is described in terms of parameters which ... Abstract: The aim of this study was to verify if abnormalities of sodium content can explain the decrease in the red blood cell ... The aggregation process is determined by sequential analysis of the He-Ne laser transmission data after passing through ...
Valverde, A., Okon, Y., & Burdman, S. (2006). cDNA-AFLP reveals differentially expressed genes related to cell aggregation of ... Valverde, A, Okon, Y & Burdman, S 2006, cDNA-AFLP reveals differentially expressed genes related to cell aggregation of ... cDNA-AFLP reveals differentially expressed genes related to cell aggregation of Azospirillum brasilense. In: FEMS Microbiology ... Dive into the research topics of cDNA-AFLP reveals differentially expressed genes related to cell aggregation of Azospirillum ...
This enables an effective representation of cell-cell adhesion, as well as random cell movement, and cell proliferation. The ... This enables an effective representation of cell-cell adhesion, as well as random cell movement, and cell proliferation. The ... this modelling approach to investigate the ability of cell-cell adhesion to generate spatial patterns during cell aggregation. ... this modelling approach to investigate the ability of cell-cell adhesion to generate spatial patterns during cell aggregation. ...
Parmeggiani F, Costagliola C, DAngelo S, Incorvaia C, Perri P, Sebastiani A. Clear cell renal cell carcinoma associated with ... These accumulations vary from dome-shaped deposits over the RPE, to linear and vertical aggregations, and other irregular ... Extensive mononuclear cell infiltrate in the choriocapillaris and choroid, as reported in histopathology, can be observed as ... A mild to moderate anterior chamber and vitreous cell reaction may be present even in the inactive stage. The patient often has ...
Flow cytometric isolation and fate mapping shows that neurosphere-initiating cells are highly mitotically active and persist ... only transiently in vivo, and are distinct from quiescent, long-lived neural stem cells. ... Preventing neurosphere aggregation after sorting. Request a detailed protocol Neurospheres can aggregate and fuse in culture, ... pre-GEPCOT cells include Type B1 cells, GEPCOT cells include Type C cells, and neuroblasts make up Type A SVZ cells (Doetsch et ...
T1 - Evaluation of cell disruption technologies on magnetosome chain length and aggregation behaviour from Magnetospirillum ... title = "Evaluation of cell disruption technologies on magnetosome chain length and aggregation behaviour from Magnetospirillum ... Evaluation of cell disruption technologies on magnetosome chain length and aggregation behaviour from Magnetospirillum ... Evaluation of cell disruption technologies on magnetosome chain length and aggregation behaviour from Magnetospirillum ...
Our results indicate that the conformation of α-synuclein is linked to the aggregation of protein in cells. They also provide ... detected by second-harmonic generation modulate the conformation of monomeric α-synuclein and reduce its aggregation in cells. ... modulators that bind to monomeric α-synuclein in vitro and significantly reduce α-synuclein aggregation in a neuronal cell ... support for a therapeutic strategy of targeting specific conformations of the protein to suppress or control its aggregation. ...
  • In molecular biology, protein aggregation is a phenomenon in which intrinsically-disordered or mis-folded proteins aggregate (i.e., accumulate and clump together) either intra- or extracellularly. (
  • In these cases, if the cell does not assist the protein in re-folding, or degrade the unfolded protein, the unfolded/misfolded protein may aggregate, in which the exposed hydrophobic portions of the protein may interact with the exposed hydrophobic patches of other proteins. (
  • citation needed] In addition to mutations in the affected proteins themselves, protein aggregation could also be caused indirectly through mutations in proteins in regulatory pathways such as the refolding pathway (molecular chaperones) or the ubiquitin-proteasome pathway (ubiquitin ligases). (
  • Here, we set to clarify this complex matter and question of whether aggregation is an important constraint in protein evolution that can be the discriminant between beneficial and detrimental situations by considering two cases: we studied molecular evolution of proteins in an endogenous vs. exogenous host. (
  • Comprehensive analysis of aggregation-inhibition effects of three major molecular chaperones working in Escherichia coli was conducted for~ 800 aggregation-prone cytosolic proteins. (
  • The results revealed that many of the~ 800 aggregation-prone proteins were solubilized by either one of the two chaperones and most of the proteins that were not solubilized by either one of the three were solubilized by the combination of the three chaperone. (
  • The aggregation of misfolded proteins has been directly linked to diseases such as type II diabetes, Alzheimer's disease and Parkinson's disease. (
  • [2] [3] The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides , proteins , lipids and DNA . (
  • Within cells, this protein may be involved in chemical signaling, transporting materials, attaching (binding) to proteins and other structures, and protecting the cell from self-destruction (apoptosis). (
  • Protein conformation diseases, including polyglutamine (polyQ) diseases, result from the accumulation and aggregation of misfolded proteins. (
  • This approach is specifically described for use with mammalian cell culture and is suitable to study other disease-related proteins prone to aggregate. (
  • Their main goal was to obtain a novel approach for tracking the aggregation of neurodegeneration-associated proteins at the very first steps of the process. (
  • Aggregation and deposition of amyloid β-protein (Aβ) in brain is an invariable and initial event in the pathological process of Alzheimer's disease. (
  • The aggregation of the amyloidogenic polypeptide IAPP (Islet Amyloid Polypeptide, amylin) is believed to play a direct role in the death of pancreatic β-islet cells in type II diabetes. (
  • These results indicate that myricetin is a strong inhibitor of IAPP amyloid aggregation and a potential lead molecule for the development of an amyloid inhibiting therapeutic. (
  • Membrane-assisted amyloid formation is implicated in human diseases, and many of the aggregating species accelerate amyloid formation and induce cell death. (
  • ROSETTA and MD simulations resulted in a unique b-strand structure distinct from the conventional amyloid b-hairpin and revealed that the nucleating NFGAIL region remains flexible and accessible within this isolated intermediate, suggesting a mechanism by which membrane-associated aggregation may be propagated. (
  • The ability of nanodiscs to trap amyloid intermediates as demonstrated could become one of the most powerful approaches to dissect the complicated misfolding pathways of protein aggregation. (
  • beta-amyloid is the main component of neuritic (senile) plaques, which consist of degenerated axonal or dendritic processes, astrocytes, and glial cells around an amyloid core. (
  • citation needed] Environmental stresses such as extreme temperatures and pH or oxidative stress can also lead to protein aggregation. (
  • Retinal pigment epithelial (RPE) cells are continually exposed to oxidative stress that contributes to protein misfolding, aggregation and functional abnormalities during aging. (
  • 1. S-Nitrosothiols are nitric oxide (NO) donor drugs that have been shown to inhibit platelet aggregation in platelet rich plasma (PRP) in vitro and to inhibit platelet activation in vivo. (
  • In wireless communication, carrier aggregation is a technique used to increase the data rate per user, whereby multiple frequency blocks (called component carriers) are assigned to the same user. (
  • In addition, load balancing: p.42 is possible with carrier aggregation. (
  • p. 113 The case where the component carriers are contiguous in the same frequency band is called intra-band contiguous carrier aggregation. (
  • If the component carriers are in the same frequency band but are separated by a gap the carrier aggregation is called intra-band non-contiguous. (
  • This is called inter-band carrier aggregation applied to heterogeneous networks. (
  • However, the complexity from an radio frequency (RF) point of view is increased in the case inter-band carrier aggregation. (
  • Carrier aggregation is also called Dual Cell in the context of UMTS/HSPA+. (
  • Through carrier aggregation (part of the UMTS extension HSPA+) two downlink carriers may be assigned to one user since Release 8. (
  • Release 10 supports four-carrier aggregation and eight-carrier-aggregation is supported since Release 11. (
  • 3GPP standardized carrier aggregation for HSPA+ for the uplink for up to two component carriers since Release 9. (
  • p.30 A difference between two aggregated 10 MHz component carriers and a single ordinary 20 MHz channel is that in the case of carrier aggregation the control information is transmitted on both component carriers. (
  • LTE Advanced with carrier aggregation allows Gigabit LTE. (
  • This is made possible through higher-order modulation (256QAM), carrier aggregation and 4x4 MIMO. (
  • S. C. G. Tsinos, F. Foukalas, T. Khattab and L. Lai "On Channel Selection for Carrier Aggregation Systems. (
  • F. Foukalas and T. Tsiftsis, "Energy Efficient Power Allocation for Carrier Aggregation in Heterogeneous Networks: Partial Feedback and Circuit Power Consumption. (
  • It was suggested that this optical effect was caused by the morphological change of platelets from discs to spherical cells with pseudopodia ( Latimer et al, 1977 ). (
  • Conclusions: Our data showed that cilostazol can downregulate not only cellular interactions between platelets and monocytic THP1 cells but also platelet P-selectin and CD40L expression. (
  • 4. Experiments involving measurement of cyclic GMP levels, electrochemical detection of NO and electron paramagnetic resonance of haemoglobin in red blood cells, indicated that scavenging of NO generated from S-nitrosothiols by haemoglobin was responsible for the lack of effect of S-nitrosothiols on platelets in whole blood. (
  • Potential cellular targets include vascular smooth muscle cells, monocyte/macrophage cell lines, platelets, and endothelial cells. (
  • Under a magnification of 1000X, this photomicrograph of a fixed blood smear, revealed a round aggregation of platelets (arrow), a polymorphonuclear leukocyte (PMN), and a number of red blood cells (RBCs). (
  • The hemorheological parameters, erythrocyte aggregation and deformability are determined in jaundice patients and are compared with that of healthy subjects. (
  • Laboratoire de Mécanique et d'Acoustique (LMA), Marseille, France Ph.D. Ultrasound characterization of erythrocyte aggregation 2012 - 2013 Specialization in Bio-engineering, Arts et Métiers Paristech, Paris - Bordeaux, France 2009 - 2013 Generalist engineer, Mechanical Engineering. (
  • Using an IAPP-EGFP (Enhanced Green Fluorescent Protein) protein construct, we find that high concentrations of myricetin slowed the in vivo aggregation of IAPP-EGFP. (
  • Pre-GEPCOT cells could not form neurospheres but expressed the stem cell markers Slc1a3-CreER T , GFAP-CreER T2 , Sox2 CreERT2 , and Gli1 CreERT2 and were long-lived in vivo. (
  • Our aim is to develop an ultrasound diagnostic tool allowing to measure quantitative parameters that reflect the red blood cell aggregation state in situ and in vivo . (
  • Shiga toxin-producing Escherichia coli (STEC) is a of STEC strains to invade epithelial cells in vitro, although pathogen that causes gastroenteritis and bloody diarrhea in small numbers ( 2,3 ), but no reports of invasion in vivo but can lead to severe disease, such as hemolytic uremic have been published. (
  • This simple pellet-based 3D culture system allows for cell aggregation and spheroid formation, facilitating cell-cell and cell-extracellular matrix interactions that better mimic the in vivo cellular environment compared with 2D monolayer cultures. (
  • abstract = "The mucin-type sialoglycoprotein, podoplanin (aggrus), is a platelet-aggregating factor on cancer cells. (
  • We demonstrate that Hsp90 inhibition by geldanamycin can effectively suppress proteasome inhibitor, MG-132-induced protein aggregation in a way that is independent of HDAC inhibition or the tubulin acetylation levels in ARPE-19 cells. (
  • The aim of this study was to compare the platelet effects of a novel S-nitrosated glyco-amino acid, RIG200, with an established S-nitrosothiol, S-nitrosoglutathione (GSNO) in PRP, and to investigate the effects of cell-free haemoglobin and red blood cells on S-nitrosothiol-mediated inhibition of platelet aggregation. (
  • Tebuconazole is a fungicide of the triazole group which treats pathogenic fungi on a plant by inhibiting ergosterol biosynthesis, an important component of fungal cell membranes, resulted in inhibition of growth and spore formation [ 5 ]. (
  • Bates G. Huntingtin aggregation and toxicity in Huntington's disease. (
  • These findings open new perspectives for understanding the pathogenesis of protein aggregation in retinal cells and can be useful for the development of therapeutic treatments to prevent retinal cell deterioration. (
  • The analysed data is represented by aggregation parameters-aggregate size index, aggregate sedimentation time index, total number of fluctuations, time required for completion of process, effective number of cells and effective cellular sedimentation duration. (
  • In contrast to the wild type parental strain Sp7, strain Sp72002, a Tn5 induced flcA - mutant, does not aggregate, does not differentiate from motile, vibroid cells into nonmotile, cyst-like forms and lacks some of the exopolysaccharide material on its cell surface. (
  • Aggregate of microorganisms in which cells that are frequently embedded within a self-produced matrix of extracellular polymeric substances (EPSs) adhere to each other and/or to a surface. (
  • Zoom-in on single cultured mammalian cells in which TDP-43 has been induced to aggregate. (
  • This protein is present in numerous cases of Amyotrophic Lateral Sclerosis (ALS) and Fronto-Temporal Dementia (FTD), where it aggregate creating insoluble protein blobs in neural cells, altering their metabolism and function. (
  • Here, we show that L-type calcium channels (L-CaChs) are required for full agrin-induced aggregation of AChRs and sufficient to induce agrin-independent AChR aggregation. (
  • Spaceflight-cultured C. albicans-induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. (
  • In a different study, in which researchers systematically analyzed mutations identical to those found in patients with Darier disease, mutant SERCA2 protein aggregates were found to cause stress to the endoplasmic reticulum, subsequently inducing cell apoptosis. (
  • CeO2 exposure was cytotoxic and altered cell function as demonstrated by fibroblast apoptosis and aggregation, and ATII cell hypertrophy and hyperplasia with increased surfactant. (
  • To identify the TJP1-dependent factors important in the development of LMS, genes with altered expression were selected in SK-LMS-1 cells such as cyclinD1, CSF1 and so on. (
  • This work demonstrates the usefulness of the cDNA-AFLP approach to reveal genes that are differentially expressed during aggregation in Azospirillum brasilense and provides insights into the aggregation process of this bacterium. (
  • [10] [11] A cell that switches to the biofilm mode of growth undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated . (
  • Recently, a body of evidence is growing that Aβ aggregation is facilitated in the presence of particular membranes lipids such as gangliosides and cholesterol and furthermore, that Aβ toxicities emerge through interaction with specific neuronal membrane microdomains such as lipid rafts. (
  • Is the Subject Area "Cell membranes" applicable to this article? (
  • To address these issues, we expressed Reelin ectopically in the developing mouse cortex, and the results showed that Reelin caused the leading processes of migrating neurons to assemble in the Reelin-rich region, which in turn induced their cell bodies to form cellular aggregates around Reelin. (
  • Interestingly, the ectopic Reelin-rich region became cell-body-sparse and dendrite-rich, resembling the MZ, and the late-born neurons migrated past their predecessors toward the central Reelin-rich region within the aggregates, resulting in a birthdate-dependent "inside-out" alignment even ectopically. (
  • The results showed that ectopic Reelin caused the leading processes of migrating neurons to assemble in the Reelin-rich region, which in turn induced their cell bodies to form aggregates, and the late-born neurons migrated past their predecessors, resulting in a birthdate-dependent "inside-out" alignment within the aggregates. (
  • Cells have mechanisms that can refold or degrade protein aggregates. (
  • However, as cells age, these control mechanisms are weakened and the cell is less able to resolve the aggregates. (
  • By using high-resolution intravital imaging techniques and hydrodynamic analyses, we show that platelet aggregation is primarily driven by changes in blood flow parameters (rheology), with soluble agonists having a secondary role, stabilizing formed aggregates. (
  • The protein aggregates formed at the cell periphery are delivered along the microtubulus network by dynein-dependent retrograde trafficking to a juxtanuclear location. (
  • We showed that the RNA aptamers can also be used to track TDP-43 in live cells and in real time, detecting all forms of the protein , from the physiological soluble one to the insoluble state, passing by aggregates of intermediate sizes undetectable by standard approaches," adds Elsa Zacco, lead researcher on the project. (
  • Four distinct stages can be defined in the evolution of the extinction coefficient ( k ) according to the aggregation behavior of the polymer donor and the non-fullerene acceptor (NFA). (
  • The probes can be used to study the behavior of the target protein in a cell and were tested in collaboration with Sapienza University of Rome, Centre for Genomic Regulation n Barcellona, University of Edinburgh and Kings College London. (
  • Further analysis revealed two clusters related to cell proliferation and the tumor microenvironment. (
  • Taken together, these results imply that TJP1 contributes to the development of sarcoma by proliferation through modulating cell-cell aggregation and communication through cytokines in the tumor microenvironment and might be a beneficial therapeutic target. (
  • The present study results indicated that compared with the same number of 2D-cultured cells, microtissue could secrete more nerve regeneration related cytokines to promote SCs proliferation and axons growth. (
  • These studies yield the effects expected for poorly soluble particles in the rat on the alveolar macrophages, in cluding inflammation and increased cell proliferation. (
  • T cells may be responsible for regulating the proliferation, and thus the growth, of malignant epithelial cells in BCC. (
  • Lung fibroblasts and alveolar type II (ATII) cells isolated from CeO2-exposed rats at 28days post-exposure demonstrated decreasing proliferation rate when compare to the controls. (
  • We observed robust tumor growth in mice transplanted with LMS cell lines expressing TJP1 while no tumor mass was found in mice transplanted with SK-LMS-1 Sh-TJP1 cells with silenced TJP1 expression. (
  • Although the agrin/MuSK signaling pathway remains largely unknown, changes in intracellular calcium levels are required for agrin-induced AChR aggregation (Megeath and Fallon [1998]: J Neurosci 18: 672-678). (
  • Our results establish a novel role for L-CaChs as important sources of the intracellular calcium necessary for the aggregation of AChRs. (
  • We sought to extend the receptor-desensitization paradigm for use with a cultured cell system, in which an intracellular calcium signal rather than a contractile response might be used as an index of receptor activation. (
  • These aptamers could be used to study, at the molecular level , the phenomenon of abnormal protein aggregation typical of several neurodegenerative diseases and would, therefore, pave the way for the development of early diagnosis tools for these disorders. (
  • The role of myeloid cells in neurodegenerative diseases. (
  • Blockade of L-CaChs in muscle cultures inhibited agrin-induced AChR aggregation but not tyrosine phosphorylation of MuSK or AChR beta subunits. (
  • We developed a calcium signaling-based assay, using cultured human embryonic kidney cells (HEK), that evaluates simultaneously, the activation/desensitization or blockade of the proteinase-activated receptors, PAR 1 and PAR 2 . (
  • Studying the ubiquitination pattern of aggregated Htt fragments offers an important possibility to understand Htt degradation and aggregation processes within the cell. (
  • We found that aggregation differentiates the effects of mutations in the two different cellular contexts. (
  • Microbes form a biofilm in response to a number of different factors, [9] which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics . (
  • Furthermore, we reasoned that, provided receptor cross-desensitization did not occur, it would be advantageous to assess PAR-targeted ligands in a cell that expressed both receptors. (
  • With both receptors present in the same cell, the selectivity or nonselectivity of a variety of compounds that would affect PAR 1 and/or PAR 2 could be efficiently evaluated in a single experiment. (
  • 2. The effects of GSNO and RIG200 in collagen (2.5 microg ml(-1))-induced platelet aggregation in PRP and whole blood were investigated in vitro. (
  • However, the in situ phenotype identification of the two main cells of the immune system cannot be reliably done on morphological grounds as they are morphologically identical [8]. (
  • In order to gain more insight into the tumour-host relationship, the present study was conducted to characterize the in situ phenotype of the lymphocytic infiltrate surrounding tumour tissue of BCC through the use of monoclonal antibodies against B and T cell populations. (
  • The above findings indicate that Reelin signaling is capable of inducing the formation of the dendrite-rich, cell-body-sparse MZ and a birthdate-dependent "inside-out" alignment of neurons independently of other factors/structures near the MZ. (
  • Aggregation leads to a substantial increase in light transmission because of the formation of large particles and the concomitant clearing of the sample. (
  • Given the double valence of protein aggregation that can result either in the formation of toxic assemblies or physiologically required organelles, it has long been debated what could determine whether aggregation is beneficial or detrimental from an evolutionary perspective. (
  • Neurosphere formation is commonly used as a surrogate for neural stem cell (NSC) function but the relationship between neurosphere-initiating cells (NICs) and NSCs remains unclear. (
  • It was concluded that the volume of the aneurysmal dome had a signifi cant infl uence on formation of a low-speed region, which is held to be responsible for active platelet aggregation. (
  • Axenic Biofilm Formation and Aggregation by Synechocystis sp. (
  • Specifically, aggregation was found to be associated with increased cell fitness in the case of TDP-43 mutations, as it protects the host from aberrant interactions. (
  • By contrast, in the case of TEM-1 beta-lactamase mutations, aggregation is linked to a decreased cell fitness due to inactivation of protein function. (
  • Any situation, such as mutations or anomalous expression, could result in disruption of these beneficial interactions with consequent aggregation and depletion of normal function. (
  • [ 22 ] Investigators transfected a fibroblast cell line with 51 different mutations seen in keratosis follicularis (Darier disease) pedigrees. (
  • First, we established a highly reactive anti-podoplanin antibody, NZ-1, which inhibits podoplanin-induced platelet aggregation completely. (
  • The correlation between the peripheral blood cells aggregation level measured by surface plasmon resonance method (SPR), and chromosomal abberations of peripheral blood lymphocytes in brain malignant gliomas patients was investigated. (
  • Interestingly, NZ-1 neutralized platelet aggregation by LN319. (
  • Basal cell carcinoma (BCC) is a malignant epithelial neoplasm and is the most common cancer in the head and neck region. (
  • Platelet aggregation and adherence to the bubble surface has been demonstrated in severe decompression sickness (DCS). (
  • Figure 2: Platelet aggregation induced shear microgradients occurs independently of ADP, TXA 2 and thrombin. (
  • We conclude that platelet aggregation occurs independently of shape change and that shape change is not necessarily followed by aggregation. (
  • Platelet aggregation at sites of vascular injury is essential for hemostasis and arterial thrombosis. (
  • It has long been assumed that platelet aggregation and thrombus growth are initiated by soluble agonists generated at sites of vascular injury. (
  • Xu, H, Salazar, DM & Xu, C 2022, ' Investigation of Cell Concentration Change and Cell Aggregation Due to Cell Sedimentation during Inkjet-Based Bioprinting of Cell-Laden Bioink ', Machines , pp. 315. (
  • In addition, although the MZ is missing in the reeler cortex, it is unknown whether Reelin directly regulates the development of the cell-body-sparse MZ. (
  • Intercellular calcium communication regulates platelet aggregation and thrombus growth. (
  • They can be found very early in Earth's fossil records (about 3.25 billion years ago) as both Archaea and Bacteria, and commonly protect prokaryotic cells by providing them with homeostasis, encouraging the development of complex interactions between the cells in the biofilm. (
  • methods for identifying the whole spectrum of STEC strains The colonization mechanism for the cell invasion is not associated with HUS. (
  • These characterization techniques necessitate the elaboration of theoretical modeling (effective medium theory combined with the structure factor model, non-linear dynamic model) describing the interaction mechanisms wave-scatterers (wave-cells, wave-porous medium). (
  • While structures of membrane-associated intermediates would provide tremendous insights into the pathology and aid in the design of compounds to potentially treat the diseases, it has not been feasible to overcome the challenges posed by the cell membrane. (
  • These findings provide insight into the prothrombotic effects of disturbed blood flow parameters and suggest a fundamental reinterpretation of the mechanisms driving platelet aggregation and thrombus growth. (
  • however, (Stx) that activates the signal pathway, leading to cell death humans of all ages can be affected. (
  • The blood samples were stimulated by adenosine diphosphate (8 μ M) for evaluation of platelet-monocytic THP1 cell aggregation and P-selectin expression and were stimulated by thrombin (0. (
  • 3. Neither compound inhibited aggregation in whole blood, even at concentrations of 100 microM. (
  • In this study, patterns of blood fl ow in three models of cerebral artery bifurcation aneurysms were numerically analysed and compared to discern the likelihood of platelet aggregation. (
  • These impingements presumably caused haemolysis, with ADP originating from haemolysed red blood cells inducing platelet aggregation. (
  • Blood samples for red blood cell counts (RBC), hematocrit (Hct), and PC were taken 1 h before and after exposure in two groups. (
  • This folding process is driven by the hydrophobic effect: a tendency for hydrophobic (water-fearing) portions of the protein to shield themselves from the hydrophilic (water-loving) environment of the cell by burying into the interior of the protein. (
  • Driven by Infinera's Advanced Coherent Optical Engines and Subsystems , our portfolio is changing the way network operators deliver services and scale capacity in their access and aggregation networks. (
  • Preventing the initial aggregation event of IAPP is one strategy for slowing, and possibly preventing, the progression of this disease. (
  • To this end, we developed a calcium-signaling assay, employing cultured human embryonic kidney cells (HEK293) in which the action of PAR 1 and PAR 2 agonists and antagonists could be evaluated simultaneously. (
  • We found that most of the previously described PAR 1 -targeted agents can also activate/desensitize PAR 2 , and most of these peptides can also activate a calcium signaling pathway in a target cell that possesses PAR 2 along with PAR 1 . (
  • The investigators found that the resultant transfected cells showed defects in ATP2A2 protein expression (15 mutants), ATP hydrolysis (29 mutants), calcium transport (4 mutants), and calcium binding and kinetics (3 mutants). (
  • In this system, the cells produce TDP-43 fused to a green fluoresce molecule, to be able to detect whether the protein forms insoluble granules (green fluorescent dots). (
  • These findings provide a fundamental understanding of the molecular aggregation during the solution casting of non-fullerene organic solar cells. (
  • Microaggregation appeared to be distinct from full aggregation, as it was not inhibited by the addition of CD61, an antibody to the β 3 integrin. (
  • The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium. (
  • Neurons that arise in the adult nervous system originate from neural stem cells and neural progenitor cells. (
  • Neural stem cells have long lives, much of which they spend in a quiescent state. (
  • Neural stem cells can also give rise to neural progenitor cells, which proliferate rapidly during their short lives and then 'differentiate' into neurons or glia. (
  • Unlike some other tissues, it has not been possible to identify or purify neural stem cells directly from the tissue. (
  • A region of the brain called the subventricular zone contains both neural stem cells and neural progenitor cells, and is one of only two regions of the brain where neural stem cells are found in adult mammals. (
  • However, the exact relationship between neural stem cells and neurosphere-forming cells has been uncertain. (
  • have used a technique called flow cytometry to identify and isolate neural stem cells and neurosphere-forming cells directly from the subventricular zone. (
  • The neural stem cells, which Mich, Signer et al. (
  • This activation leads to platelet-monocyte aggregation, platelet P-selectin, and CD40 ligand (CD40L) expression. (
  • We aim to determine the effects of cilostazol on platelet activation as measured by platelet-monocyte aggregation, platelet P-selectin, and CD40L expression. (
  • Results: Pretreatment with cilostazol significantly suppressed platelet-monocytic THP1 cell aggregation, P-selectin, and CD40L expression in a concentration-dependent manner at concentrations of 10 1 , 10 2 , and 10 3 mM, respectively. (