A non-fibrillar collagen found in the structure of BASEMENT MEMBRANE. Collagen type IV molecules assemble to form a sheet-like network which is involved in maintaining the structural integrity of basement membranes. The predominant form of the protein is comprised of two alpha1(IV) subunits and one alpha2(IV) subunit, however, at least six different alpha subunits can be incorporated into the heterotrimer.
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 most common form of fibrillar collagen. It is a major constituent of bone (BONE AND BONES) and SKIN and consists of a heterotrimer of two alpha1(I) and one alpha2(I) chains.
A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.
Large, noncollagenous glycoprotein with antigenic properties. It is localized in the basement membrane lamina lucida and functions to bind epithelial cells to the basement membrane. Evidence suggests that the protein plays a role in tumor invasion.
A fibrillar collagen consisting of three identical alpha1(III) chains that is widely distributed in many tissues containing COLLAGEN TYPE I. It is particularly abundant in BLOOD VESSELS and may play a role in tissues with elastic characteristics.
A fibrillar collagen found predominantly in CARTILAGE and vitreous humor. It consists of three identical alpha1(II) chains.
A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.
Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).
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.
Collagen receptors are cell surface receptors that modulate signal transduction between cells and the EXTRACELLULAR MATRIX. They are found in many cell types and are involved in the maintenance and regulation of cell shape and behavior, including PLATELET ACTIVATION and aggregation, through many different signaling pathways and differences in their affinities for collagen isoforms. Collagen receptors include discoidin domain receptors, INTEGRINS, and glycoprotein VI.
A fibrillar collagen found widely distributed as a minor component in tissues that contain COLLAGEN TYPE I and COLLAGEN TYPE III. It is a heterotrimeric molecule composed of alpha1(V), alpha2(V) and alpha3(V) subunits. Several forms of collagen type V exist depending upon the composition of the subunits that form the trimer.
A family of structurally related collagens that form the characteristic collagen fibril bundles seen in CONNECTIVE TISSUE.
An integrin alpha subunit that primarily combines with INTEGRIN BETA1 to form the INTEGRIN ALPHA2BETA1 heterodimer. It contains a domain which has homology to collagen-binding domains found in von Willebrand factor.
A protease nexin and serpin subtype that is specific for several SERINE PROTEASES including UROKINASE; THROMBIN; TRYPSIN; and PLASMINOGEN ACTIVATORS.
A non-fibrillar collagen that forms a network of MICROFIBRILS within the EXTRACELLULAR MATRIX of CONNECTIVE TISSUE. The alpha subunits of collagen type VI assemble into antiparallel, overlapping dimers which then align to form tetramers.
A fibrillar collagen found primarily in interstitial CARTILAGE. Collagen type XI is heterotrimer containing alpha1(XI), alpha2(XI) and alpha3(XI) subunits.
Adherence of cells to surfaces or to other cells.
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.
Extracellular protease inhibitors that are secreted from FIBROBLASTS. They form a covalent complex with SERINE PROTEASES and can mediate their cellular internalization and degradation.
Acquired degenerative dilation or expansion (ectasia) of normal BLOOD VESSELS, often associated with aging. They are isolated, tortuous, thin-walled vessels and sources of bleeding. They occur most often in mucosal capillaries of the GASTROINTESTINAL TRACT leading to GASTROINTESTINAL HEMORRHAGE and ANEMIA.
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.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Integrin beta-1 chains which are expressed as heterodimers that are noncovalently associated with specific alpha-chains of the CD49 family (CD49a-f). CD29 is expressed on resting and activated leukocytes and is a marker for all of the very late activation antigens on cells. (from: Barclay et al., The Leukocyte Antigen FactsBook, 1993, p164)
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A biosynthetic precursor of collagen containing additional amino acid sequences at the amino-terminal and carboxyl-terminal ends of the polypeptide chains.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A secreted endopeptidase homologous with INTERSTITIAL COLLAGENASE, but which possesses an additional fibronectin-like domain.
Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.
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.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A metalloproteinase which degrades helical regions of native collagen to small fragments. Preferred cleavage is -Gly in the sequence -Pro-Xaa-Gly-Pro-. Six forms (or 2 classes) have been isolated from Clostridium histolyticum that are immunologically cross-reactive but possess different sequences and different specificities. Other variants have been isolated from Bacillus cereus, Empedobacter collagenolyticum, Pseudomonas marinoglutinosa, and species of Vibrio and Streptomyces. EC 3.4.24.3.
A factor synthesized in a wide variety of tissues. It acts synergistically with TGF-alpha in inducing phenotypic transformation and can also act as a negative autocrine growth factor. TGF-beta has a potential role in embryonal development, cellular differentiation, hormone secretion, and immune function. TGF-beta is found mostly as homodimer forms of separate gene products TGF-beta1, TGF-beta2 or TGF-beta3. Heterodimers composed of TGF-beta1 and 2 (TGF-beta1.2) or of TGF-beta2 and 3 (TGF-beta2.3) have been isolated. The TGF-beta proteins are synthesized as precursor proteins.
A non-fibrillar collagen found in BASEMENT MEMBRANE. The C-terminal end of the alpha1 chain of collagen type XVIII contains the ENDOSTATIN peptide, which can be released by proteolytic cleavage.
Specific cell surface receptors which bind to FIBRONECTINS. Studies have shown that these receptors function in certain types of adhesive contact as well as playing a major role in matrix assembly. These receptors include the traditional fibronectin receptor, also called INTEGRIN ALPHA5BETA1 and several other integrins.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A non-fibrillar collagen found primarily in terminally differentiated hypertrophic CHONDROCYTES. It is a homotrimer of three identical alpha1(X) subunits.
A non-vascular form of connective tissue composed of CHONDROCYTES embedded in a matrix that includes CHONDROITIN SULFATE and various types of FIBRILLAR COLLAGEN. There are three major types: HYALINE CARTILAGE; FIBROCARTILAGE; and ELASTIC CARTILAGE.
A hydroxylated form of the imino acid proline. A deficiency in ASCORBIC ACID can result in impaired hydroxyproline formation.
A fibril-associated collagen found in many tissues bearing high tensile stress, such as TENDONS and LIGAMENTS. It is comprised of a trimer of three identical alpha1(XII) chains.
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.
Enzymes that catalyze the degradation of collagen by acting on the peptide bonds.
Ubiquitous macromolecules associated with the cell surface and extracellular matrix of a wide range of cells of vertebrate and invertebrate tissues. They are essential cofactors in cell-matrix adhesion processes, in cell-cell recognition systems, and in receptor-growth factor interactions. (From Cancer Metastasis Rev 1996; 15(2): 177-86; Hepatology 1996; 24(3): 524-32)
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The thin membranous structure supporting the adjoining glomerular capillaries. It is composed of GLOMERULAR MESANGIAL CELLS and their EXTRACELLULAR MATRIX.
An endopeptidase that is structurally similar to MATRIX METALLOPROTEINASE 2. It degrades GELATIN types I and V; COLLAGEN TYPE IV; and COLLAGEN TYPE V.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.
Historically, a heterogeneous group of acute and chronic diseases, including rheumatoid arthritis, systemic lupus erythematosus, progressive systemic sclerosis, dermatomyositis, etc. This classification was based on the notion that "collagen" was equivalent to "connective tissue", but with the present recognition of the different types of collagen and the aggregates derived from them as distinct entities, the term "collagen diseases" now pertains exclusively to those inherited conditions in which the primary defect is at the gene level and affects collagen biosynthesis, post-translational modification, or extracellular processing directly. (From Cecil Textbook of Medicine, 19th ed, p1494)
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.
Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.
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.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
Glycoproteins which have a very high polysaccharide content.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.
A small leucine-rich proteoglycan that interacts with FIBRILLAR COLLAGENS and modifies the EXTRACELLULAR MATRIX structure of CONNECTIVE TISSUE. Decorin has also been shown to play additional roles in the regulation of cellular responses to GROWTH FACTORS. The protein contains a single glycosaminoglycan chain and is similar in structure to BIGLYCAN.
A fibril-associated collagen usually found crosslinked to the surface of COLLAGEN TYPE II fibrils. It is a heterotrimer containing alpha1(IX), alpha2(IX) and alpha3(IX) subunits.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.
The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Polymorphic cells that form cartilage.
PROGESTERONE-producing cells in the CORPUS LUTEUM. The large luteal cells derive from the GRANULOSA CELLS. The small luteal cells derive from the THECA CELLS.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
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.
Elements of limited time intervals, contributing to particular results or situations.
Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).
Fibrous bands or cords of CONNECTIVE TISSUE at the ends of SKELETAL MUSCLE FIBERS that serve to attach the MUSCLES to bones and other structures.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
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 non-fibrillar collagen originally found in DESCEMET MEMBRANE. It is expressed in endothelial cell layers and in tissues undergoing active remodeling. It is heterotrimer comprised of alpha1(VIII) and alpha2(VIII) chains.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
Basic glycoprotein members of the SERPIN SUPERFAMILY that function as COLLAGEN-specific MOLECULAR CHAPERONES in the ENDOPLASMIC RETICULUM.
Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.
Established cell cultures that have the potential to propagate indefinitely.
A non-fibrillar collagen involved in anchoring the epidermal BASEMENT MEMBRANE to underlying tissue. It is a homotrimer comprised of C-terminal and N-terminal globular domains connected by a central triple-helical region.
A group of inherited conditions characterized initially by HEMATURIA and slowly progressing to RENAL INSUFFICIENCY. The most common form is the Alport syndrome (hereditary nephritis with HEARING LOSS) which is caused by mutations in genes for TYPE IV COLLAGEN and defective GLOMERULAR BASEMENT MEMBRANE.
A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.
A subtype of transforming growth factor beta that is synthesized by a wide variety of cells. It is synthesized as a precursor molecule that is cleaved to form mature TGF-beta 1 and TGF-beta1 latency-associated peptide. The association of the cleavage products results in the formation a latent protein which must be activated to bind its receptor. Defects in the gene that encodes TGF-beta1 are the cause of CAMURATI-ENGELMANN SYNDROME.
Glycoproteins found on the membrane or surface of cells.
A class of enzymes that catalyzes the degradation of gelatin by acting on the peptide bonds. EC 3.4.24.-.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Tissue that supports and binds other tissues. It consists of CONNECTIVE TISSUE CELLS embedded in a large amount of EXTRACELLULAR MATRIX.
ENDOPEPTIDASES which use a metal such as ZINC in the catalytic mechanism.
COLLAGEN DISEASES characterized by brittle, osteoporotic, and easily fractured bones. It may also present with blue sclerae, loose joints, and imperfect dentin formation. Most types are autosomal dominant and are associated with mutations in COLLAGEN TYPE I.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Proteins that are structural components of bacterial fimbriae (FIMBRIAE, BACTERIAL) or sex pili (PILI, SEX).
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Integrin alpha1beta1 functions as a receptor for LAMININ and COLLAGEN. It is widely expressed during development, but in the adult is the predominant laminin receptor (RECEPTORS, LAMININ) in mature SMOOTH MUSCLE CELLS, where it is important for maintenance of the differentiated phenotype of these cells. Integrin alpha1beta1 is also found in LYMPHOCYTES and microvascular endothelial cells, and may play a role in angiogenesis. In SCHWANN CELLS and neural crest cells, it is involved in cell migration. Integrin alpha1beta1 is also known as VLA-1 and CD49a-CD29.
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.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
'Elastin' is a highly elastic protein in connective tissue that allows many tissues in the body to resume their shape after stretching or contracting, such as the skin, lungs, and blood vessels.
A layer of the cornea. It is the basal lamina of the CORNEAL ENDOTHELIUM (from which it is secreted) separating it from the CORNEAL STROMA. It is a homogeneous structure composed of fine collagenous filaments, and slowly increases in thickness with age.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
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.
Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A hypertriglyceridemia disorder, often with autosomal dominant inheritance. It is characterized by the persistent elevations of plasma TRIGLYCERIDES, endogenously synthesized and contained predominantly in VERY-LOW-DENSITY LIPOPROTEINS (pre-beta lipoproteins). In contrast, the plasma CHOLESTEROL and PHOSPHOLIPIDS usually remain within normal limits.
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Heteropolysaccharides which contain an N-acetylated hexosamine in a characteristic repeating disaccharide unit. The repeating structure of each disaccharide involves alternate 1,4- and 1,3-linkages consisting of either N-acetylglucosamine or N-acetylgalactosamine.
An autosomal recessive metabolic disorder due to a deficiency in expression of glycogen branching enzyme 1 (alpha-1,4-glucan-6-alpha-glucosyltransferase), resulting in an accumulation of abnormal GLYCOGEN with long outer branches. Clinical features are MUSCLE HYPOTONIA and CIRRHOSIS. Death from liver disease usually occurs before age 2.
A member of the metalloproteinase family of enzymes that is principally responsible for cleaving FIBRILLAR COLLAGEN. It can degrade interstitial collagens, types I, II and III.
A mixed-function oxygenase that catalyzes the hydroxylation of peptidyllysine, usually in protocollagen, to peptidylhydroxylysine. The enzyme utilizes molecular oxygen with concomitant oxidative decarboxylation of the cosubstrate 2-oxoglutarate to succinate. EC 1.14.11.4.
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.
The formation of cartilage. This process is directed by CHONDROCYTES which continually divide and lay down matrix during development. It is sometimes a precursor to OSTEOGENESIS.
Large HYALURONAN-containing proteoglycans found in articular cartilage (CARTILAGE, ARTICULAR). They form into aggregates that provide tissues with the capacity to resist high compressive and tensile forces.
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.
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.
A heterogeneous group of autosomally inherited COLLAGEN DISEASES caused by defects in the synthesis or structure of FIBRILLAR COLLAGEN. There are numerous subtypes: classical, hypermobility, vascular, and others. Common clinical features include hyperextensible skin and joints, skin fragility and reduced wound healing capability.
A product formed from skin, white connective tissue, or bone COLLAGEN. It is used as a protein food adjuvant, plasma substitute, hemostatic, suspending agent in pharmaceutical preparations, and in the manufacturing of capsules and suppositories.
The process whereby PLATELETS adhere to something other than platelets, e.g., COLLAGEN; BASEMENT MEMBRANE; MICROFIBRILS; or other "foreign" surfaces.
A family of non-fibrillar collagens that interact with FIBRILLAR COLLAGENS. They contain short triple helical domains interrupted by short non-helical domains and do not form into collagen fibrils.
Restoration of integrity to traumatized tissue.
A proteolytic enzyme that converts PLASMINOGEN to FIBRINOLYSIN where the preferential cleavage is between ARGININE and VALINE. It was isolated originally from human URINE, but is found in most tissues of most VERTEBRATES.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
Transport proteins that carry specific substances in the blood or across cell membranes.
Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.
Proteins found in any species of bacterium.
The lamellated connective tissue constituting the thickest layer of the cornea between the Bowman and Descemet membranes.
A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.
A family of secreted protease inhibitory proteins that regulates the activity of SECRETED MATRIX METALLOENDOPEPTIDASES. They play an important role in modulating the proteolysis of EXTRACELLULAR MATRIX, most notably during tissue remodeling and inflammatory processes.
A member of the family of TISSUE INHIBITOR OF METALLOPROTEINASES. It is a N-glycosylated protein, molecular weight 28 kD, produced by a vast range of cell types and found in a variety of tissues and body fluids. It has been shown to suppress metastasis and inhibit tumor invasion in vitro.
Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.
A family of structurally-related short-chain collagens that do not form large fibril bundles.
A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.
A small leucine-rich proteoglycan found in a variety of tissues including CAPILLARY ENDOTHELIUM; SKELETAL MUSCLE; CARTILAGE; BONE; and TENDONS. The protein contains two glycosaminoglycan chains and is similar in structure to DECORIN.
Filamentous or elongated proteinaceous structures which extend from the cell surface in gram-negative bacteria that contain certain types of conjugative plasmid. These pili are the organs associated with genetic transfer and have essential roles in conjugation. Normally, only one or a few pili occur on a given donor cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed, p675) This preferred use of "pili" refers to the sexual appendage, to be distinguished from bacterial fimbriae (FIMBRIAE, BACTERIAL), also known as common pili, which are usually concerned with adhesion.
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.
ARTHRITIS that is induced in experimental animals. Immunological methods and infectious agents can be used to develop experimental arthritis models. These methods include injections of stimulators of the immune response, such as an adjuvant (ADJUVANTS, IMMUNOLOGIC) or COLLAGEN.
An integrin alpha subunit that binds COLLAGEN and LAMININ though its I domain. It combines with INTEGRIN BETA1 to form the heterodimer INTEGRIN ALPHA1BETA1.
A non-fibrillar collagen found as a ubiquitously expressed membrane- associated protein. Type XIII collagen contains both collagenous and non-collagenous domains along with a transmembrane domain within its N-terminal region.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A family of zinc-dependent metalloendopeptidases that is involved in the degradation of EXTRACELLULAR MATRIX components.
Proteins prepared by recombinant DNA technology.
Methods for maintaining or growing CELLS in vitro.
Chemicals with two conjoined aromatic rings incorporating two nitrogen atoms and one of the carbons oxidized with a keto oxygen.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Proteoglycans consisting of proteins linked to one or more CHONDROITIN SULFATE-containing oligosaccharide chains.
A mixed-function oxygenase that catalyzes the hydroxylation of a prolyl-glycyl containing peptide, usually in PROTOCOLLAGEN, to a hydroxyprolylglycyl-containing-peptide. The enzyme utilizes molecular OXYGEN with a concomitant oxidative decarboxylation of 2-oxoglutarate to SUCCINATE. The enzyme occurs as a tetramer of two alpha and two beta subunits. The beta subunit of procollagen-proline dioxygenase is identical to the enzyme PROTEIN DISULFIDE-ISOMERASES.
The process of bone formation. Histogenesis of bone including ossification.
A member of the family of TISSUE INHIBITOR OF METALLOPROTEINASES. It is a 21-kDa nonglycosylated protein found in tissue fluid and is secreted as a complex with progelatinase A by human fibroblast and uncomplexed from alveolar macrophages. An overexpression of TIMP-2 has been shown to inhibit invasive and metastatic activity of tumor cells and decrease tumor growth in vivo.
Non-collagenous, calcium-binding glycoprotein of developing bone. It links collagen to mineral in the bone matrix. In the synonym SPARC glycoprotein, the acronym stands for Secreted Protein, Acidic and Rich in Cysteine.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
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.
A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.
An autoimmune disease of the KIDNEY and the LUNG. It is characterized by the presence of circulating autoantibodies targeting the epitopes in the non-collagenous domains of COLLAGEN TYPE IV in the basement membranes of kidney glomeruli (KIDNEY GLOMERULUS) and lung alveoli (PULMONARY ALVEOLI), and the subsequent destruction of these basement membranes. Clinical features include pulmonary alveolar hemorrhage and glomerulonephritis.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A layer of vascularized connective tissue underneath the EPIDERMIS. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are SWEAT GLANDS; HAIR FOLLICLES; and SEBACEOUS GLANDS.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
The rate dynamics in chemical or physical systems.
The sum of the weight of all the atoms in a molecule.
The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
Connective tissue comprised chiefly of elastic fibers. Elastic fibers have two components: ELASTIN and MICROFIBRILS.
Antibodies produced by a single clone of cells.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
Any of the 23 plates of fibrocartilage found between the bodies of adjacent VERTEBRAE.
Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
A CCN protein family member that regulates a variety of extracellular functions including CELL ADHESION; CELL MIGRATION; and EXTRACELLULAR MATRIX synthesis. It is found in hypertrophic CHONDROCYTES where it may play a role in CHONDROGENESIS and endochondral ossification.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
An enzyme oxidizing peptidyl-lysyl-peptide in the presence of water & molecular oxygen to yield peptidyl-allysyl-peptide plus ammonia & hydrogen peroxide. EC 1.4.3.13.
One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.
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).
Perisinusoidal cells of the liver, located in the space of Disse between HEPATOCYTES and sinusoidal endothelial cells.
An integrin found on fibroblasts, platelets, endothelial and epithelial cells, and lymphocytes where it functions as a receptor for COLLAGEN and LAMININ. Although originally referred to as the collagen receptor, it is one of several receptors for collagen. Ligand binding to integrin alpha2beta1 triggers a cascade of intracellular signaling, including activation of p38 MAP kinase.
In GRAM NEGATIVE BACTERIA, multiprotein complexes that function to translocate pathogen protein effector molecules across the bacterial cell envelope, often directly into the host. These effectors are involved in producing surface structures for adhesion, bacterial motility, manipulation of host functions, modulation of host defense responses, and other functions involved in facilitating survival of the pathogen. Several of the systems have homologous components functioning similarly in GRAM POSITIVE BACTERIA.
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.
The area between the EPIPHYSIS and the DIAPHYSIS within which bone growth occurs.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
A sharply elevated, irregularly shaped, progressively enlarging scar resulting from formation of excessive amounts of collagen in the dermis during connective tissue repair. It is differentiated from a hypertrophic scar (CICATRIX, HYPERTROPHIC) in that the former does not spread to surrounding tissues.
An extracellular endopeptidase of vertebrate tissues similar to MATRIX METALLOPROTEINASE 1. It digests PROTEOGLYCAN; FIBRONECTIN; COLLAGEN types III, IV, V, and IX, and activates procollagenase. (Enzyme Nomenclature, 1992)
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.
A group of cells that includes FIBROBLASTS, cartilage cells, ADIPOCYTES, smooth muscle cells, and bone cells.
Inbred DBA mice are a strain of laboratory mice that are genetically identical and share specific characteristics, including a high incidence of deafness, coat color (black and white), and susceptibility to certain diseases, which make them useful for research purposes in biomedical studies.
Process by which organic tissue becomes hardened by the physiologic deposit of calcium salts.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
A progressive, degenerative joint disease, the most common form of arthritis, especially in older persons. The disease is thought to result not from the aging process but from biochemical changes and biomechanical stresses affecting articular cartilage. In the foreign literature it is often called osteoarthrosis deformans.
The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.
A natural high-viscosity mucopolysaccharide with alternating beta (1-3) glucuronide and beta (1-4) glucosaminidic bonds. It is found in the UMBILICAL CORD, in VITREOUS BODY and in SYNOVIAL FLUID. A high urinary level is found in PROGERIA.
A species of gram-negative, aerobic bacteria isolated from soil and the stems, leafs, and roots of plants. Some biotypes are pathogenic and cause the formation of PLANT TUMORS in a wide variety of higher plants. The species is a major research tool in biotechnology.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
Reagent used as an intermediate in the manufacture of beta-alanine and pantothenic acid.
Peptides composed of between two and twelve amino acids.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
Bone-forming cells which secrete an EXTRACELLULAR MATRIX. HYDROXYAPATITE crystals are then deposited into the matrix to form bone.
A scleroprotein fibril consisting mostly of type III collagen. Reticulin fibrils are extremely thin, with a diameter of between 0.5 and 2 um. They are involved in maintaining the structural integrity in a variety of organs.
Hexameric extracellular matrix glycoprotein transiently expressed in many developing organs and often re-expressed in tumors. It is present in the central and peripheral nervous systems as well as in smooth muscle and tendons. (From Kreis & Vale, Guidebook to the Extracellular Matrix and Adhesion Proteins, 1993, p93)
A high-molecular-weight plasma protein, produced by endothelial cells and megakaryocytes, that is part of the factor VIII/von Willebrand factor complex. The von Willebrand factor has receptors for collagen, platelets, and ristocetin activity as well as the immunologically distinct antigenic determinants. It functions in adhesion of platelets to collagen and hemostatic plug formation. The prolonged bleeding time in VON WILLEBRAND DISEASES is due to the deficiency of this factor.
A group of inherited metabolic diseases characterized by the accumulation of excessive amounts of acid mucopolysaccharides, sphingolipids, and/or glycolipids in visceral and mesenchymal cells. Abnormal amounts of sphingolipids or glycolipids are present in neural tissue. INTELLECTUAL DISABILITY and skeletal changes, most notably dysostosis multiplex, occur frequently. (From Joynt, Clinical Neurology, 1992, Ch56, pp36-7)

Goodpasture antigen: expression of the full-length alpha3(IV) chain of collagen IV and localization of epitopes exclusively to the noncollagenous domain. (1/975)

BACKGROUND: Tissue injury in Goodpasture (GP) syndrome (rapidly progressive glomerular nephritis and pulmonary hemorrhage) is mediated by antibasement membrane antibodies that are targeted to the alpha3(IV) chain of type IV collagen, one of five alpha(IV) chains that occur in the glomerular basement membrane. GP antibodies are known to bind epitopes within the carboxyl terminal noncollagenous domain (NC1) of the alpha3(IV) chain, termed the GP autoantigen. Whether epitopes also exist in the 1400-residue collagenous domain is unknown because studies to date have focused solely on the NC1 domain. A knowledge of GP epitopes is important for the understanding of the etiology and pathogenesis of the disease and for the development of therapeutic strategies. METHODS: A cDNA construct was prepared for the full-length human alpha3(IV) chain. The construct was stably transfected into human embryonic kidney 293 cells. The purified full-length r-alpha3(IV) chain was characterized by electrophoresis and electron microscopy. The capacity of this chain for binding of GP antibodies from five patients was compared with that of the human r-alpha3(IV)NC1 domain by competitive enzyme-linked immunosorbent assay. RESULTS: The r-alpha3(IV) chain was secreted from 293 cells as a single polypeptide chain that did not spontaneously undergo assembly into a triple-helical molecule. An analysis of GP-antibody binding to the full-length r-alpha3(IV) chain showed binding exclusively to the globular NC1 domain. CONCLUSION: The full-length human alpha3(IV) chain possesses the capacity to bind GP autoantibodies. The epitope(s) is found exclusively on the nontriple-helical NC1 domain of the alpha3(IV) chain, indicating the presence of specific immunogenic properties. The alpha3(IV) chain alone does not spontaneously undergo assembly into a triple-helical homotrimeric molecule, suggesting that coassembly with either the alpha4(IV) and/or the alpha5(IV) chain may be required for triple-helix formation.  (+info)

Identification of a clinically relevant immunodominant region of collagen IV in Goodpasture disease. (2/975)

BACKGROUND: The characteristic feature of Goodpasture disease is the occurrence of an autoantibody response to the noncollagenous domain of the alpha3 chain of type IV collagen [alpha3(IV)NC1] in the alveolar and glomerular basement membrane. These antibodies are associated with the development of a rapidly progressive glomerulonephritis, with or without lung hemorrhage, whereas autoantibodies specific for the other alpha chains of the heterotrimeric type IV collagen probably do not cause disease. In this study, we have investigated whether differences in fine specificity of autoimmune recognition of the alpha3(IV)NC1 correlate with clinical outcome. METHODS: For mapping of antibody binding to type IV collagen, chimeric collagen constructs were generated in which parts of the alpha3(IV)NC1 domain were replaced by the corresponding sequences of homologous nonreactive alpha1(IV). The different recombinant collagen chimeras allowed the analysis of antibody specificities in 77 sera from well-documented patients. RESULTS: One construct that harbors the aminoterminal third of the alpha3(IV)NC1 was recognized by all sera, indicating that it represents the dominant target of the B-cell response in Goodpasture disease. Seventy percent of the samples recognized other parts of the molecule as well. However, only reactivity to the N-terminus of the alpha3(IV)NC1 correlated with prognosis, that is, kidney survival after six months of follow-up. CONCLUSION: The results indicate the crucial importance of antibody recognition of this particular domain for the pathogenesis of Goodpasture disease, thereby opening new avenues for the development of better diagnostic and therapeutic procedures.  (+info)

The goodpasture autoantigen. Mapping the major conformational epitope(s) of alpha3(IV) collagen to residues 17-31 and 127-141 of the NC1 domain. (3/975)

The Goodpasture (GP) autoantigen has been identified as the alpha3(IV) collagen chain, one of six homologous chains designated alpha1-alpha6 that comprise type IV collagen (Hudson, B. G., Reeders, S. T., and Tryggvason, K. (1993) J. Biol. Chem. 268, 26033-26036). In this study, chimeric proteins were used to map the location of the major conformational, disulfide bond-dependent GP autoepitope(s) that has been previously localized to the noncollagenous (NC1) domain of alpha3(IV) chain. Fourteen alpha1/alpha3 NC1 chimeras were constructed by substituting one or more short sequences of alpha3(IV)NC1 at the corresponding positions in the non-immunoreactive alpha1(IV)NC1 domain and expressed in mammalian cells for proper folding. The interaction between the chimeras and eight GP sera was assessed by both direct and inhibition enzyme-linked immunosorbent assay. Two chimeras, C2 containing residues 17-31 of alpha3(IV)NC1 and C6 containing residues 127-141 of alpha3(IV)NC1, bound autoantibodies, as did combination chimeras containing these regions. The epitope(s) that encompasses these sequences is immunodominant, showing strong reactivity with all GP sera and accounting for 50-90% of the autoantibody reactivity toward alpha3(IV)NC1. The conformational nature of the epitope(s) in the C2 and C6 chimeras was established by reduction of the disulfide bonds and by PEPSCAN analysis of overlapping 12-mer peptides derived from alpha1- and alpha3(IV)NC1 sequences. The amino acid sequences 17-31 and 127-141 in alpha3(IV)NC1 have thus been shown to contain the critical residues of one or two disulfide bond-dependent conformational autoepitopes that bind GP autoantibodies.  (+info)

Characterization of a novel type of serine/threonine kinase that specifically phosphorylates the human goodpasture antigen. (4/975)

Goodpasture disease is an autoimmune disorder that occurs naturally only in humans. Also exclusive to humans is the phosphorylation process that targets the unique N-terminal region of the Goodpasture antigen. Here we report the molecular cloning of GPBP (Goodpasture antigen-binding protein), a previously unknown 624-residue polypeptide. Although the predicted sequence does not meet the conventional structural requirements for a protein kinase, its recombinant counterpart specifically binds to and phosphorylates the exclusive N-terminal region of the human Goodpasture antigen in vitro. This novel kinase is widely expressed in human tissues but shows preferential expression in the histological structures that are targets of common autoimmune responses. The work presented in this report highlights a novel gene to be explored in human autoimmunity.  (+info)

The goodpasture autoantigen. Identification of multiple cryptic epitopes on the NC1 domain of the alpha3(IV) collagen chain. (5/975)

Goodpasture (GP) disease is an autoimmune disorder in which autoantibodies against the alpha3(IV) chain of type IV collagen bind to the glomerular and alveolar basement membranes, causing progressive glomerulonephritis and pulmonary hemorrhage. Two major conformational epitope regions have been identified on the noncollagenous domain of type IV collagen (NC1 domain) of the alpha3(IV) chain as residues 17-31 (E(A)) and 127-141 (E(B)) (Netzer, K.-O. et al. (1999) J. Biol. Chem. 274, 11267-11274). To determine whether these regions are two distinct epitopes or form a single epitope, three GP sera were fractionated by affinity chromatography on immobilized NC1 chimeras containing the E(A) and/or the E(B) region. Four subpopulations of GP antibodies with distinct epitope specificity for the alpha3(IV)NC1 domain were thus separated and characterized. They were designated GP(A), GP(B), GP(AB), and GP(X), to reflect their reactivity with E(A) only, E(B) only, both regions, and neither, respectively. Hence, regions E(A) and E(B) encompass critical amino acids that constitute three distinct epitopes for GP(A), GP(B), and GP(AB) antibodies, respectively, whereas the epitope for GP(X) antibodies is located in a different unknown region. The GP(A) antibodies were consistently immunodominant, accounting for 60-65% of the total immunoreactivity to alpha3(IV)NC1; thus, they probably play a major role in pathogenesis. Regions E(A) and E(B) are held in close proximity because they jointly form the epitope for Mab3, a monoclonal antibody that competes for binding with GP autoantibodies. All GP epitopes are sequestered in the hexamer configuration of the NC1 domain found in tissues and are inaccessible for antibody binding unless dissociation of the hexamer occurs, suggesting a possible mechanism for etiology of GP disease. GP antibodies have the capacity to extract alpha3(IV)NC1 monomers, but not dimers, from native human glomerular basement membrane hexamers, a property that may be of fundamental importance for the pathogenesis of the disease.  (+info)

Distinct antitumor properties of a type IV collagen domain derived from basement membrane. (6/975)

Vascular basement membrane is an important structural component of blood vessels. During angiogenesis this membrane undergoes many alterations and these changes are speculated to influence the formation of new capillaries. Type IV collagen is a major component of vascular basement membrane, and recently we identified a fragment of type IV collagen alpha2 chain with specific anti-angiogenic properties (Kamphaus, G. D., Colorado, P. C., Panka, D. J., Hopfer, H., Ramchandran, R., Torre, A., Maeshima, Y., Mier, J. W., Sukhatme, V. P., and Kalluri, R. (2000) J. Biol. Chem. 275, 1209-1215). In the present study we characterize two different antitumor activities associated with the noncollagenous 1 (NC1) domain of the alpha3 chain of type IV collagen. This domain was previously discovered to possess a C-terminal peptide sequence (amino acids 185-203) that inhibits melanoma cell proliferation (Han, J., Ohno, N., Pasco, S., Monboisse, J. C., Borel, J. P., and Kefalides, N. A. (1997) J. Biol. Chem. 272, 20395-20401). In the present study, we identify the anti-angiogenic capacity of this domain using several in vitro and in vivo assays. The alpha3(IV)NC1 inhibited in vivo neovascularization in matrigel plug assays and suppressed tumor growth of human renal cell carcinoma (786-O) and prostate carcinoma (PC-3) in mouse xenograft models associated with in vivo endothelial cell-specific apoptosis. The anti-angiogenic activity was localized to amino acids 54-132 using deletion mutagenesis. This anti-angiogenic region is separate from the 185-203 amino acid region responsible for the antitumor cell activity. Additionally, our experiments indicate that the antitumor cell activity is not realized until the peptide region is exposed by truncation of the alpha3(IV)NC1 domain, a requirement not essential for the anti-angiogenic activity of this domain. Collectively, these results effectively highlight the distinct and unique antitumor properties of the alpha3(IV)NC1 domain and the potential use of this molecule for inhibition of tumor growth.  (+info)

Two RGD-independent alpha vbeta 3 integrin binding sites on tumstatin regulate distinct anti-tumor properties. (7/975)

Vascular basement membrane is an important regulator of angiogenesis and undergoes many alterations during angiogenesis and these changes are speculated to influence neovascularization. Recently, fragments of collagen molecules have been identified to possess anti-angiogenic activity. Tumstatin (alpha3(IV)NC1 domain) is one such novel molecule with distinct anti-tumor properties and possesses an N-terminal (amino acids 54-132) anti-angiogenic and a C-terminal (amino acids 185-203) anti-tumor cell activity (Maeshima, Y., et al. 2000) J. Biol. Chem. 275, 21340-21348). Previous studies have identified the 185-203 amino acid sequence as a ligand for alpha(v)beta(3) integrin (Shahan, T. A., et al. (1999) Cancer Res. 59, 4584-4590). In the present study, we found distinct additional RGD-independent alpha(v)beta(3) integrin binding site within 54-132 amino acids of tumstatin. This site is not essential for inhibition of tumor cell proliferation but necessary for the anti-angiogenic activity. A fragment of tumstatin containing 54-132 amino acid (tum-2) binds both endothelial cells and melanoma cells but only inhibited proliferation of endothelial cells, with no effect on tumor cell proliferation. A similar experiment with fragment of tumstatin containing the 185-203 amino acid (tum-4) demonstrates that it binds both endothelial cells and melanoma cells but only inhibits the proliferation of melanoma cells. The presence of cyclic RGD peptides did not affect the alpha(v)beta(3) integrin-mediated activity of tumstatin, although significant inhibition of endothelial cell binding to vitronectin was observed. The two distinct RGD-independent binding sites on tumstatin suggest unique alpha(v)beta(3) integrin-mediated mechanisms governing the two distinct anti-tumor properties of tumstatin.  (+info)

High affinity of anti-GBM antibodies from Goodpasture and transplanted Alport patients to alpha3(IV)NC1 collagen. (8/975)

BACKGROUND: Anti-glomerular basement membrane (anti-GBM) antibody-mediated diseases are characterized by rapidly progressive glomerulonephritis (RPGN) that often results in irreversible loss of renal function and renal failure. Although many factors contribute to the fulminant nature and treatment resistance of this disease, we questioned whether high affinity autoantibody-alpha3(IV) collagen interactions lead to persistent antibody deposition, thereby perpetuating inflammation. To address this hypothesis, the binding kinetics of human anti-GBM antibodies (Ab) to alpha3(IV)NC1 were evaluated using an optical biosensor interaction analysis. METHODS: Polyclonal anti-GBM Abs were purified by alpha3(IV)NC1 affinity chromatography from the sera of patients with anti-GBM AB-mediated diseases, including individuals with Goodpasture syndrome (GS), idiopathic RPGN (N = 7), and Alport syndrome (AL) following kidney transplantation (N = 4). The affinity-binding characteristics of the autoantibodies were determined using a biosensor analysis system, with immobilized bovine alpha3(IV)NC1 dimers. RESULTS: All of the autoantibody preparations bound to alpha3(IV)NC1, whereas none bound to alpha1(IV)NC1 (control). Purified, normal serum IgG did not bind to either antigen. Estimated dissociation constants (Kd) for the purified autoantibodies were 1.39E-04 +/- 7.30E-05 s-l (GS) and 8. 90E-05 +/- 2.80E-05 s-l (AL). Their estimated association constants (Ka) were 2.67E+04 +/- 1.8E+04 (M-ls-l) and 2.76E+04 +/- 1. 70E+04(M-ls-l) for GS and AL patients, respectively. By comparison with other Ab interactions, these Abs demonstrated high affinity, with relatively high on (binding) rates and slow off (dissociation) rates. CONCLUSIONS: The results suggest that anti-GBM Abs bind rapidly and remain tightly bound to the GBM in vivo. This property likely contributes to both the fulminant nature of this disease and its resistance to therapy, because persistent glomerular Ab deposition has the potential to produce continuous inflammation, despite removal of circulating Abs and adequate immunosuppression.  (+info)

Collagen Type IV is a type of collagen that forms the structural basis of basement membranes, which are thin, sheet-like structures that separate and support cells in many types of tissues. It is a major component of the basement membrane's extracellular matrix and provides strength and flexibility to this structure. Collagen Type IV is composed of three chains that form a distinctive, mesh-like structure. Mutations in the genes encoding Collagen Type IV can lead to a variety of inherited disorders affecting the kidneys, eyes, and ears.

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.

Collagen Type I is the most abundant form of collagen in the human body, found in various connective tissues such as tendons, ligaments, skin, and bones. It is a structural protein that provides strength and integrity to these tissues. Collagen Type I is composed of three alpha chains, two alpha-1(I) chains, and one alpha-2(I) chain, arranged in a triple helix structure. This type of collagen is often used in medical research and clinical applications, such as tissue engineering and regenerative medicine, due to its excellent mechanical properties and biocompatibility.

The basement membrane is a thin, specialized layer of extracellular matrix that provides structural support and separates epithelial cells (which line the outer surfaces of organs and blood vessels) from connective tissue. It is composed of two main layers: the basal lamina, which is produced by the epithelial cells, and the reticular lamina, which is produced by the connective tissue. The basement membrane plays important roles in cell adhesion, migration, differentiation, and survival.

The basal lamina is composed mainly of type IV collagen, laminins, nidogens, and proteoglycans, while the reticular lamina contains type III collagen, fibronectin, and other matrix proteins. The basement membrane also contains a variety of growth factors and cytokines that can influence cell behavior.

Defects in the composition or organization of the basement membrane can lead to various diseases, including kidney disease, eye disease, and skin blistering disorders.

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

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

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

Collagen Type III, also known as Collagen III Alpha 1 (COL3A1), is a type of collagen that is found in various connective tissues throughout the body. It is a fibrillar collagen that is produced by fibroblasts and is a major component of reticular fibers, which provide structural support to organs such as the liver, spleen, and lymph nodes. Collagen Type III is also found in the walls of blood vessels, the skin, and the intestinal tract.

Mutations in the COL3A1 gene can lead to a rare genetic disorder called Ehlers-Danlos syndrome type IV, which is characterized by fragile and elastic skin, easy bruising, and spontaneous rupture of blood vessels. Collagen Type III has been studied for its potential role in various other medical conditions, including fibrosis, cancer, and cardiovascular disease.

Collagen Type II is a specific type of collagen that is a major component of the extracellular matrix in articular cartilage, which is the connective tissue that covers and protects the ends of bones in joints. It is also found in other tissues such as the vitreous humor of the eye and the inner ear.

Collagen Type II is a triple helix molecule composed of three polypeptide chains that contain a high proportion of the amino acids proline and hydroxyproline. This type of collagen provides structural support and elasticity to tissues, and it also plays a role in the regulation of cell behavior and signaling.

Collagen Type II is a target for autoimmune responses in conditions such as rheumatoid arthritis, where the immune system mistakenly attacks the body's own collagen, leading to joint inflammation and damage. It is also a common component of various dietary supplements and therapies used to support joint health and treat osteoarthritis.

The extracellular matrix (ECM) is a complex network of biomolecules that provides structural and biochemical support to cells in tissues and organs. It is composed of various proteins, glycoproteins, and polysaccharides, such as collagens, elastin, fibronectin, laminin, and proteoglycans. The ECM plays crucial roles in maintaining tissue architecture, regulating cell behavior, and facilitating communication between cells. It provides a scaffold for cell attachment, migration, and differentiation, and helps to maintain the structural integrity of tissues by resisting mechanical stresses. Additionally, the ECM contains various growth factors, cytokines, and chemokines that can influence cellular processes such as proliferation, survival, and differentiation. Overall, the extracellular matrix is essential for the normal functioning of tissues and organs, and its dysregulation can contribute to various pathological conditions, including fibrosis, cancer, and degenerative diseases.

Extracellular matrix (ECM) proteins are a group of structural and functional molecules that provide support, organization, and regulation to the cells in tissues and organs. The ECM is composed of a complex network of proteins, glycoproteins, and carbohydrates that are secreted by the cells and deposited outside of them.

ECM proteins can be classified into several categories based on their structure and function, including:

1. Collagens: These are the most abundant ECM proteins and provide strength and stability to tissues. They form fibrils that can withstand high tensile forces.
2. Proteoglycans: These are complex molecules made up of a core protein and one or more glycosaminoglycan (GAG) chains. The GAG chains attract water, making proteoglycans important for maintaining tissue hydration and resilience.
3. Elastin: This is an elastic protein that allows tissues to stretch and recoil, such as in the lungs and blood vessels.
4. Fibronectins: These are large glycoproteins that bind to cells and ECM components, providing adhesion, migration, and signaling functions.
5. Laminins: These are large proteins found in basement membranes, which provide structural support for epithelial and endothelial cells.
6. Tenascins: These are large glycoproteins that modulate cell adhesion and migration, and regulate ECM assembly and remodeling.

Together, these ECM proteins create a microenvironment that influences cell behavior, differentiation, and function. Dysregulation of ECM proteins has been implicated in various diseases, including fibrosis, cancer, and degenerative disorders.

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.

Collagen receptors are a type of cell surface receptor that bind to collagen molecules, which are the most abundant proteins in the extracellular matrix (ECM) of connective tissues. These receptors play important roles in various biological processes, including cell adhesion, migration, differentiation, and survival.

Collagen receptors can be classified into two major groups: integrins and discoidin domain receptors (DDRs). Integrins are heterodimeric transmembrane proteins that consist of an alpha and a beta subunit. They bind to collagens via their arginine-glycine-aspartic acid (RGD) motif, which is located in the triple-helical domain of collagen molecules. Integrins mediate cell-collagen interactions by clustering and forming focal adhesions, which are large protein complexes that connect the ECM to the cytoskeleton.

DDRs are receptor tyrosine kinases (RTKs) that contain a discoidin domain in their extracellular region, which is responsible for collagen binding. DDRs bind to collagens via their non-RGD motifs and induce intracellular signaling pathways that regulate cell behavior.

Abnormalities in collagen receptor function have been implicated in various diseases, including fibrosis, cancer, and inflammation. Therefore, understanding the structure and function of collagen receptors is crucial for developing novel therapeutic strategies to treat these conditions.

Collagen Type V is a specific type of collagen, which is a protein that provides structure and strength to connective tissues in the body. Collagen Type V is found in various tissues, including the cornea, blood vessels, and hair. It plays a crucial role in the formation of collagen fibers and helps regulate the diameter of collagen fibrils. Mutations in the genes that encode for Collagen Type V can lead to various connective tissue disorders, such as Ehlers-Danlos syndrome and osteogenesis imperfecta.

Fibrillar collagens are a type of collagen that form rope-like fibrils in the extracellular matrix of connective tissues. They are composed of three polypeptide chains, called alpha chains, which are coiled together in a triple helix structure. The most common types of fibrillar collagens are Type I, II, III, V, and XI. These collagens provide strength and support to tissues such as tendons, ligaments, skin, and bones. They also play important roles in the regulation of cell behavior and tissue development. Mutations in genes encoding fibrillar collagens can lead to a variety of connective tissue disorders, including osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome.

Integrin alpha2, also known as CD49b or ITGA2, is a type I transmembrane glycoprotein that forms a heterodimer with integrin beta1 to create the collagen receptor very late antigen-2 (VLA-2) or α2β1 integrin. This integrin plays crucial roles in various cellular processes such as adhesion, migration, and signaling during embryonic development, hemostasis, and tissue repair. It specifically binds to collagen types I, II, and IV, contributing to the regulation of cell-matrix interactions in several tissues, including bone, cartilage, and vascular systems. Integrin alpha2 also participates in immune responses by mediating lymphocyte adhesion and activation.

Serpin E2, also known as Neuroserpin, is a member of the serine protease inhibitor (Serpin) superfamily. It is primarily expressed in neuronal cells and plays a crucial role in regulating tissue plasminogen activator (tPA), a protein involved in the breakdown of blood clots. Serpin E2 helps to prevent excessive proteolytic activity, which can lead to neurodegeneration and other neurological disorders. Mutations in the SERPINE2 gene have been associated with certain forms of dementia and cerebral amyloid angiopathy (CAA), a condition characterized by the accumulation of beta-amyloid protein in the walls of blood vessels in the brain.

Collagen Type VI is a type of collagen that is widely expressed in various tissues, including skeletal muscle, skin, and blood vessels. It is a major component of the extracellular matrix and plays important roles in maintaining tissue structure and function. Collagen Type VI forms microfilaments that provide structural support to the basement membrane and regulate cell-matrix interactions. Mutations in the genes encoding collagen Type VI can lead to several inherited connective tissue disorders, such as Bethlem myopathy and Ullrich congenital muscular dystrophy.

Collagen type XI is a fibrillar collagen that is found in the extracellular matrix of various tissues, including cartilage and the eye. It is a homotrimer made up of three identical alpha 1(XI) chains or a heterotrimer composed of two alpha 1(XI) chains and one alpha 2(XI) chain. Collagen type XI is closely associated with collagen type II fibrils and plays a role in regulating the diameter and organization of these fibrils. Mutations in the genes encoding collagen type XI can lead to skeletal disorders such as stiff skin syndrome and fibrodysplasia ossificans progressiva.

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.

"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.

Protease nexins are a group of proteins that regulate the activity of proteases, which are enzymes that break down other proteins. Proteases play important roles in various biological processes, including blood clotting, immune response, and cell death. However, uncontrolled or excessive protease activity can lead to harmful effects, such as tissue damage and disease progression.

Protease nexins function by forming stable complexes with specific proteases, thereby inhibiting their activity. These complexes also serve as a reservoir of inactive proteases that can be rapidly activated when needed. Protease nexins are involved in various physiological and pathological processes, such as inflammation, neurodegeneration, and cancer.

One well-known example of a protease nexin is the tissue plasminogen activator (tPA) - neuroserpin complex. Neuroserpin is a serine protease inhibitor that forms a complex with tPA, an enzyme that plays a critical role in breaking down blood clots. By forming this complex, neuroserpin regulates the activity of tPA and prevents excessive fibrinolysis, which can lead to bleeding disorders. Mutations in the gene encoding neuroserpin have been associated with familial dementia with Lewy bodies, a form of neurodegenerative disorder.

Angiodysplasia is a vascular disorder characterized by the dilation and abnormal formation of blood vessels, particularly in the gastrointestinal (GI) tract. These abnormal blood vessels are prone to leakage or rupture, which can lead to bleeding. Angiodysplasia is most commonly found in the colon but can occur in other parts of the GI tract as well. It is more common in older adults and can cause symptoms such as anemia, fatigue, and bloody stools. The exact cause of angiodysplasia is not known, but it may be associated with chronic low-grade inflammation or increased pressure in the blood vessels. Treatment options include endoscopic therapies to stop bleeding, medications to reduce acid production in the stomach, and surgery in severe cases.

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.

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

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

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

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

CD29, also known as integrin β1, is a type of cell surface protein called an integrin that forms heterodimers with various α subunits to form different integrin receptors. These integrin receptors play important roles in various biological processes such as cell adhesion, migration, and signaling.

CD29/integrin β1 is widely expressed on many types of cells including leukocytes, endothelial cells, epithelial cells, and fibroblasts. It can bind to several extracellular matrix proteins such as collagen, laminin, and fibronectin, and mediate cell-matrix interactions. CD29/integrin β1 also participates in intracellular signaling pathways that regulate cell survival, proliferation, differentiation, and migration.

CD29/integrin β1 can function as an antigen, which is a molecule capable of inducing an immune response. Antibodies against CD29/integrin β1 have been found in some autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus (SLE). These antibodies can contribute to the pathogenesis of these diseases by activating complement, inducing inflammation, and damaging tissues.

Therefore, CD29/integrin β1 is an important molecule in both physiological and pathological processes, and its functions as an antigen have been implicated in some autoimmune disorders.

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.

Procollagen is the precursor protein of collagen, which is a major structural protein in the extracellular matrix of various connective tissues, such as tendons, ligaments, skin, and bones. Procollagen is synthesized inside the cell (in the rough endoplasmic reticulum) and then processed by enzymes to remove specific segments, resulting in the formation of tropocollagen, which are the basic units of collagen fibrils.

Procollagen consists of three polypeptide chains (two alpha-1 and one alpha-2 chain), each containing a central triple-helical domain flanked by non-helical regions at both ends. These non-helical regions, called propeptides, are cleaved off during the processing of procollagen to tropocollagen, allowing the individual collagen molecules to align and form fibrils through covalent cross-linking.

Abnormalities in procollagen synthesis or processing can lead to various connective tissue disorders, such as osteogenesis imperfecta (brittle bone disease) and Ehlers-Danlos syndrome (a group of disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility).

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

Matrix metalloproteinase 2 (MMP-2), also known as gelatinase A, is an enzyme that belongs to the matrix metalloproteinase family. MMPs are involved in the breakdown of extracellular matrix components, and MMP-2 is responsible for degrading type IV collagen, a major component of the basement membrane. This enzyme plays a crucial role in various physiological processes, including tissue remodeling, wound healing, and angiogenesis. However, its dysregulation has been implicated in several pathological conditions, such as cancer, arthritis, and cardiovascular diseases. MMP-2 is synthesized as an inactive proenzyme and requires activation by other proteases or chemical modifications before it can exert its proteolytic activity.

Fibrosis is a pathological process characterized by the excessive accumulation and/or altered deposition of extracellular matrix components, particularly collagen, in various tissues and organs. This results in the formation of fibrous scar tissue that can impair organ function and structure. Fibrosis can occur as a result of chronic inflammation, tissue injury, or abnormal repair mechanisms, and it is a common feature of many diseases, including liver cirrhosis, lung fibrosis, heart failure, and kidney disease.

In medical terms, fibrosis is defined as:

"The process of producing scar tissue (consisting of collagen) in response to injury or chronic inflammation in normal connective tissue. This can lead to the thickening and stiffening of affected tissues and organs, impairing their function."

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.

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.

Microbial collagenase is not a medical term per se, but it does refer to an enzyme that is used in various medical and research contexts. Collagenases are a group of enzymes that break down collagen, a structural protein found in connective tissues such as skin, tendons, and ligaments. Microbial collagenase is a type of collagenase that is produced by certain bacteria, such as Clostridium histolyticum.

In medical terms, microbial collagenase is used in various therapeutic and research applications, including:

1. Wound healing: Microbial collagenase can be used to break down and remove necrotic tissue from wounds, which can help promote healing and prevent infection.
2. Dental applications: Collagenases have been used in periodontal therapy to remove calculus and improve the effectiveness of root planing and scaling procedures.
3. Research: Microbial collagenase is a valuable tool for researchers studying the structure and function of collagen and other extracellular matrix proteins. It can be used to digest tissue samples, allowing scientists to study the individual components of the extracellular matrix.

It's important to note that while microbial collagenase has many useful applications, it must be used with care, as excessive or improper use can damage healthy tissues and cause adverse effects.

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

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

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

Collagen type XVIII is a type of collagen that is found in the basement membrane, which is a thin layer of extracellular matrix that separates and supports epithelial and endothelial cells. It is a heterotrimeric protein composed of three different chains, alpha1(XVIII), alpha2(XVIII), and alpha3(XVIII). Collagen XVIII is thought to play a role in the maintenance and organization of the basement membrane, as well as in cell adhesion and migration. It also contains a number of distinct domains that are involved in various biological processes, including angiogenesis, tissue repair, and tumor growth. Mutations in the gene that encodes collagen XVIII have been associated with eye diseases such as Knobloch syndrome and familial exudative vitreoretinopathy.

Fibronectin receptors are a type of cell surface adhesion molecule that bind to the extracellular matrix protein fibronectin. These receptors are composed of transmembrane glycoproteins called integrins, which consist of non-covalently associated α and β subunits. The binding of fibronectin to its receptor triggers a range of intracellular signaling events that regulate various cellular functions, including cell adhesion, migration, proliferation, differentiation, and survival.

Fibronectin receptors play critical roles in many physiological processes, such as embryonic development, tissue repair, and hemostasis. They also contribute to the pathogenesis of various diseases, including fibrosis, cancer, and cardiovascular disease. In cancer, for example, increased expression of fibronectin receptors has been associated with tumor progression, metastasis, and drug resistance. Therefore, targeting fibronectin receptors has emerged as a promising therapeutic strategy for treating various diseases.

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.

Collagen type X is a specific type of collagen that is primarily found in the hypertrophic zone of mature cartilage, which is located near the site of bone formation during endochondral ossification. It plays a crucial role in the mineralization process of the cartilage matrix and is essential for the formation of healthy bones. Collagen type X is composed of three identical alpha chains that form a triple helix structure, and it is synthesized by chondrocytes, which are the specialized cells found in cartilage tissue. Mutations in the gene that encodes collagen type X have been associated with certain skeletal disorders, such as Schmid metaphyseal chondrodysplasia.

Cartilage is a type of connective tissue that is found throughout the body in various forms. It is made up of specialized cells called chondrocytes, which are embedded in a firm, flexible matrix composed of collagen fibers and proteoglycans. This unique structure gives cartilage its characteristic properties of being both strong and flexible.

There are three main types of cartilage in the human body: hyaline cartilage, elastic cartilage, and fibrocartilage.

1. Hyaline cartilage is the most common type and is found in areas such as the articular surfaces of bones (where they meet to form joints), the nose, trachea, and larynx. It has a smooth, glassy appearance and provides a smooth, lubricated surface for joint movement.
2. Elastic cartilage contains more elastin fibers than hyaline cartilage, which gives it greater flexibility and resilience. It is found in structures such as the external ear and parts of the larynx and epiglottis.
3. Fibrocartilage has a higher proportion of collagen fibers and fewer chondrocytes than hyaline or elastic cartilage. It is found in areas that require high tensile strength, such as the intervertebral discs, menisci (found in joints like the knee), and the pubic symphysis.

Cartilage plays a crucial role in supporting and protecting various structures within the body, allowing for smooth movement and providing a cushion between bones to absorb shock and prevent wear and tear. However, cartilage has limited capacity for self-repair and regeneration, making damage or degeneration of cartilage tissue a significant concern in conditions such as osteoarthritis.

Hydroxyproline is not a medical term per se, but it is a significant component in the medical field, particularly in the study of connective tissues and collagen. Here's a scientific definition:

Hydroxyproline is a modified amino acid that is formed by the post-translational modification of the amino acid proline in collagen and some other proteins. This process involves the addition of a hydroxyl group (-OH) to the proline residue, which alters its chemical properties and contributes to the stability and structure of collagen fibers. Collagen is the most abundant protein in the human body and is a crucial component of connective tissues such as tendons, ligaments, skin, and bones. The presence and quantity of hydroxyproline can serve as a marker for collagen turnover and degradation, making it relevant to various medical and research contexts, including the study of diseases affecting connective tissues like osteoarthritis, rheumatoid arthritis, and Ehlers-Danlos syndrome.

Collagen type XII is a type of collagen that is found in the extracellular matrix of various tissues, including tendons, ligaments, and skin. It is a fibril-associated collagen that is closely associated with collagens type I and III. Collagen type XII has been shown to play a role in regulating the organization and diameter of collagen fibrils. Mutations in the gene for collagen type XII have been associated with certain types of muscular dystrophy and Bethlem myopathy, which are genetic disorders that affect muscle strength and tone. Additionally, it has been suggested to play a role in the development of osteoarthritis.

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.

Collagenases are a group of enzymes that have the ability to break down collagen, which is a structural protein found in connective tissues such as tendons, ligaments, and skin. Collagen is an important component of the extracellular matrix, providing strength and support to tissues throughout the body.

Collagenases are produced by various organisms, including bacteria, animals, and humans. In humans, collagenases play a crucial role in normal tissue remodeling and repair processes, such as wound healing and bone resorption. However, excessive or uncontrolled activity of collagenases can contribute to the development of various diseases, including arthritis, periodontitis, and cancer metastasis.

Bacterial collagenases are often used in research and medical applications for their ability to digest collagen quickly and efficiently. For example, they may be used to study the structure and function of collagen or to isolate cells from tissues. However, the clinical use of bacterial collagenases is limited due to concerns about their potential to cause tissue damage and inflammation.

Overall, collagenases are important enzymes that play a critical role in maintaining the health and integrity of connective tissues throughout the body.

Heparan sulfate proteoglycans (HSPGs) are complex molecules composed of a core protein to which one or more heparan sulfate (HS) glycosaminoglycan chains are covalently attached. They are widely distributed in animal tissues and play crucial roles in various biological processes, including cell-cell communication, growth factor signaling, viral infection, and cancer metastasis.

The HS chains are long, linear polysaccharides composed of repeating disaccharide units of glucosamine and uronic acid (either glucuronic or iduronic acid). These chains contain sulfate groups at various positions, which give them a negative charge and allow them to interact with numerous proteins, growth factors, and enzymes.

HSPGs can be found on the cell surface (syndecans and glypicans) or in the extracellular matrix (perlecans and agrin). They act as co-receptors for many signaling molecules, such as fibroblast growth factors (FGFs), wingless-type MMTV integration site family members (WNTs), and hedgehog proteins. By modulating the activity of these signaling pathways, HSPGs help regulate various cellular functions, including proliferation, differentiation, migration, and adhesion.

Dysregulation of HSPGs has been implicated in several diseases, such as cancer, fibrosis, and viral infections (e.g., HIV and herpes simplex virus). Therefore, understanding the structure and function of HSPGs is essential for developing new therapeutic strategies to target these diseases.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

The glomerular mesangium is a part of the nephron in the kidney. It is the region located in the middle of the glomerular tuft, where the capillary loops of the glomerulus are surrounded by a network of extracellular matrix and mesangial cells. These cells and matrix play an important role in maintaining the structure and function of the filtration barrier in the glomerulus, which helps to filter waste products from the blood.

The mesangial cells have contractile properties and can regulate the flow of blood through the capillaries by constricting or dilating the diameter of the glomerular capillary loops. They also play a role in immune responses, as they can phagocytize immune complexes and release cytokines and growth factors that modulate inflammation and tissue repair.

Abnormalities in the mesangium can lead to various kidney diseases, such as glomerulonephritis, mesangial proliferative glomerulonephritis, and diabetic nephropathy.

Medical Definition:

Matrix metalloproteinase 9 (MMP-9), also known as gelatinase B or 92 kDa type IV collagenase, is a member of the matrix metalloproteinase family. These enzymes are involved in degrading and remodeling the extracellular matrix (ECM) components, playing crucial roles in various physiological and pathological processes such as wound healing, tissue repair, and tumor metastasis.

MMP-9 is secreted as an inactive zymogen and activated upon removal of its propeptide domain. It can degrade several ECM proteins, including type IV collagen, elastin, fibronectin, and gelatin. MMP-9 has been implicated in numerous diseases, such as cancer, rheumatoid arthritis, neurological disorders, and cardiovascular diseases. Its expression is regulated at the transcriptional, translational, and post-translational levels, and its activity can be controlled by endogenous inhibitors called tissue inhibitors of metalloproteinases (TIMPs).

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.

A kidney glomerulus is a functional unit in the nephron of the kidney. It is a tuft of capillaries enclosed within a structure called Bowman's capsule, which filters waste and excess fluids from the blood. The glomerulus receives blood from an afferent arteriole and drains into an efferent arteriole.

The process of filtration in the glomerulus is called ultrafiltration, where the pressure within the glomerular capillaries drives plasma fluid and small molecules (such as ions, glucose, amino acids, and waste products) through the filtration membrane into the Bowman's space. Larger molecules, like proteins and blood cells, are retained in the blood due to their larger size. The filtrate then continues down the nephron for further processing, eventually forming urine.

Collagen diseases, also known as collagen disorders or connective tissue diseases, refer to a group of medical conditions that affect the body's connective tissues. These tissues provide support and structure for various organs and systems in the body, including the skin, joints, muscles, and blood vessels.

Collagen is a major component of connective tissues, and it plays a crucial role in maintaining their strength and elasticity. In collagen diseases, the body's immune system mistakenly attacks healthy collagen, leading to inflammation, pain, and damage to the affected tissues.

There are several types of collagen diseases, including:

1. Systemic Lupus Erythematosus (SLE): This is a chronic autoimmune disease that can affect various organs and systems in the body, including the skin, joints, kidneys, heart, and lungs.
2. Rheumatoid Arthritis (RA): This is a chronic inflammatory disease that primarily affects the joints, causing pain, swelling, and stiffness.
3. Scleroderma: This is a rare autoimmune disorder that causes thickening and hardening of the skin and connective tissues, leading to restricted movement and organ damage.
4. Dermatomyositis: This is an inflammatory muscle disease that can also affect the skin, causing rashes and weakness.
5. Mixed Connective Tissue Disease (MCTD): This is a rare autoimmune disorder that combines symptoms of several collagen diseases, including SLE, RA, scleroderma, and dermatomyositis.

The exact cause of collagen diseases is not fully understood, but they are believed to be related to genetic, environmental, and hormonal factors. Treatment typically involves a combination of medications, lifestyle changes, and physical therapy to manage symptoms and prevent complications.

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.

Pepsin A is defined as a digestive enzyme that is primarily secreted by the chief cells in the stomach's fundic glands. It plays a crucial role in protein catabolism, helping to break down food proteins into smaller peptides during the digestive process. Pepsin A has an optimal pH range of 1.5-2.5 for its enzymatic activity and is activated from its inactive precursor, pepsinogen, upon exposure to acidic conditions in the stomach.

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.

A kidney, in medical terms, is one of two bean-shaped organs located in the lower back region of the body. They are essential for maintaining homeostasis within the body by performing several crucial functions such as:

1. Regulation of water and electrolyte balance: Kidneys help regulate the amount of water and various electrolytes like sodium, potassium, and calcium in the bloodstream to maintain a stable internal environment.

2. Excretion of waste products: They filter waste products from the blood, including urea (a byproduct of protein metabolism), creatinine (a breakdown product of muscle tissue), and other harmful substances that result from normal cellular functions or external sources like medications and toxins.

3. Endocrine function: Kidneys produce several hormones with important roles in the body, such as erythropoietin (stimulates red blood cell production), renin (regulates blood pressure), and calcitriol (activated form of vitamin D that helps regulate calcium homeostasis).

4. pH balance regulation: Kidneys maintain the proper acid-base balance in the body by excreting either hydrogen ions or bicarbonate ions, depending on whether the blood is too acidic or too alkaline.

5. Blood pressure control: The kidneys play a significant role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS), which constricts blood vessels and promotes sodium and water retention to increase blood volume and, consequently, blood pressure.

Anatomically, each kidney is approximately 10-12 cm long, 5-7 cm wide, and 3 cm thick, with a weight of about 120-170 grams. They are surrounded by a protective layer of fat and connected to the urinary system through the renal pelvis, ureters, bladder, and urethra.

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

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

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

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

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.

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.

Decorin is a small proteoglycan, a type of protein with a attached sugar chain, that is found in the extracellular matrix of connective tissues in the body. It is composed of a core protein and one or more glycosaminoglycan (GAG) chains, specifically dermatan sulfate. Decorin plays important roles in the organization and biomechanical properties of collagen fibrils, regulation of cell proliferation and migration, and modulation of growth factor activity. It has been studied for its potential role in various physiological and pathological processes, including wound healing, fibrosis, and cancer.

Collagen type IX is a type of collagen that is found in the extracellular matrix, particularly in the cartilage and vitreous humor of the eye. It is a heterotrimeric protein made up of three alpha chains (alpha1, alpha2, and alpha3), which are encoded by different genes (COL9A1, COL9A2, and COL9A3). Collagen type IX is thought to play a role in the organization and stability of collagen fibrils, as well as in the interaction between collagen and other extracellular matrix components. It has been implicated in various connective tissue disorders, such as Stickler syndrome and Marshall syndrome.

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.

Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. It provides a cushion between bones and allows for smooth movement by reducing friction. Articular cartilage also absorbs shock and distributes loads evenly across the joint, protecting the bones from damage. It is avascular, meaning it does not have its own blood supply, and relies on the surrounding synovial fluid for nutrients. Over time, articular cartilage can wear down or become damaged due to injury or disease, leading to conditions such as osteoarthritis.

In medical terms, the skin is the largest organ of the human body. It consists of two main layers: the epidermis (outer layer) and dermis (inner layer), as well as accessory structures like hair follicles, sweat glands, and oil glands. The skin plays a crucial role in protecting us from external factors such as bacteria, viruses, and environmental hazards, while also regulating body temperature and enabling the sense of touch.

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

The Western blotting procedure involves several steps:

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

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

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

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

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

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

Chondrocytes are the specialized cells that produce and maintain the extracellular matrix of cartilage tissue. They are responsible for synthesizing and secreting the collagen fibers, proteoglycans, and other components that give cartilage its unique properties, such as elasticity, resiliency, and resistance to compression. Chondrocytes are located within lacunae, or small cavities, in the cartilage matrix, and they receive nutrients and oxygen through diffusion from the surrounding tissue fluid. They are capable of adapting to changes in mechanical stress by modulating the production and organization of the extracellular matrix, which allows cartilage to withstand various loads and maintain its structural integrity. Chondrocytes play a crucial role in the development, maintenance, and repair of cartilaginous tissues throughout the body, including articular cartilage, costal cartilage, and growth plate cartilage.

Luteal cells, also known as granulosa-lutein cells, are specialized cells found in the ovary that play a crucial role in the menstrual cycle and pregnancy. They are formed from the granulosa cells of the ovarian follicle after ovulation, during which the follicle ruptures and releases the egg (oocyte). The remaining cells then transform into luteal cells, forming a structure called the corpus luteum.

The primary function of luteal cells is to produce and secrete progesterone and estrogen, two hormones that are essential for preparing the uterus for implantation of a fertilized egg and maintaining early pregnancy. Progesterone stimulates the growth of blood vessels in the endometrium (the lining of the uterus), making it thicker and more receptive to the implantation of a fertilized egg. It also suppresses further development of ovarian follicles, preventing the release of additional eggs during pregnancy.

If pregnancy does not occur, the corpus luteum will degenerate, and the levels of progesterone and estrogen will decrease, leading to menstruation. However, if pregnancy occurs, the developing embryo will produce human chorionic gonadotropin (hCG), which stimulates the luteal cells to continue producing progesterone and estrogen until the placenta takes over these functions around the 10th week of gestation.

In summary, luteal cells are specialized ovarian cells that produce and secrete progesterone and estrogen during the menstrual cycle and early pregnancy to prepare the uterus for implantation and maintain pregnancy.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

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

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

Examples of animal disease models include:

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

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

'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.

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.

Bacterial fimbriae are thin, hair-like protein appendages that extend from the surface of many types of bacteria. They are involved in the attachment of bacteria to surfaces, other cells, or extracellular structures. Fimbriae enable bacteria to adhere to host tissues and form biofilms, which contribute to bacterial pathogenicity and survival in various environments. These protein structures are composed of several thousand subunits of a specific protein called pilin. Some fimbriae can recognize and bind to specific receptors on host cells, initiating the process of infection and colonization.

A tendon is the strong, flexible band of tissue that connects muscle to bone. It helps transfer the force produced by the muscle to allow various movements of our body parts. Tendons are made up of collagen fibers arranged in parallel bundles and have a poor blood supply, making them prone to injuries and slow to heal. Examples include the Achilles tendon, which connects the calf muscle to the heel bone, and the patellar tendon, which connects the kneecap to the shinbone.

Macromolecular substances, also known as macromolecules, are large, complex molecules made up of repeating subunits called monomers. These substances are formed through polymerization, a process in which many small molecules combine to form a larger one. Macromolecular substances can be naturally occurring, such as proteins, DNA, and carbohydrates, or synthetic, such as plastics and synthetic fibers.

In the context of medicine, macromolecular substances are often used in the development of drugs and medical devices. For example, some drugs are designed to bind to specific macromolecules in the body, such as proteins or DNA, in order to alter their function and produce a therapeutic effect. Additionally, macromolecular substances may be used in the creation of medical implants, such as artificial joints and heart valves, due to their strength and durability.

It is important for healthcare professionals to have an understanding of macromolecular substances and how they function in the body, as this knowledge can inform the development and use of medical treatments.

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.

Collagen type VIII is a less common type of collagen that is found in the eyes, specifically in the basement membrane of the cornea and the blood vessels of the eye. It is a network-forming collagen and is believed to play a role in maintaining the structural integrity and stability of these tissues. Mutations in the genes encoding for collagen type VIII have been associated with certain eye disorders, such as Fuchs' endothelial corneal dystrophy.

Here is a medical definition from the US National Library of Medicine:

"Collagen, type VIII, alpha-1 (COL8A1) is a gene that provides instructions for making one component of a type VIII collagen protein called collagen VIII alpha-1 chain. Collagen proteins are important building blocks for many tissues in the body, including tendons, ligaments, and the cornea, which is the clear outer covering of the eye.

Collagen VIII is found in the basement membrane, a thin layer of protein that surrounds many types of cells and helps to anchor them to surrounding tissue. In the eye, collagen VIII is produced by cells called endothelial cells, which line the inside surface of the cornea. Collagen VIII forms networks with other proteins that help maintain the structural integrity and stability of the cornea.

Mutations in the COL8A1 gene can cause Fuchs' endothelial corneal dystrophy, a progressive eye disorder characterized by the gradual clouding of the cornea." ()

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

HSP47 (Heat Shock Protein 47) is a type of molecular chaperone that assists in the proper folding and assembly of collagen molecules within the endoplasmic reticulum (ER) of eukaryotic cells. It is also known as SERPINH1, which stands for serine protease inhibitor, clade H (heat shock protein 47).

HSP47 binds to procollagen molecules in a highly specific manner and helps facilitate their correct folding and assembly into higher-order structures. Once the collagen molecules are properly assembled, HSP47 dissociates from them and allows for their transport out of the ER and further processing in the Golgi apparatus.

HSP47 is upregulated under conditions of cellular stress, such as heat shock or oxidative stress, which can lead to an accumulation of misfolded proteins within the ER. This upregulation helps to enhance the protein folding capacity of the ER and prevent the aggregation of misfolded proteins, thereby maintaining cellular homeostasis.

Defects in HSP47 function have been implicated in various connective tissue disorders, such as osteogenesis imperfecta and Ehlers-Danlos syndrome, which are characterized by abnormal collagen structure and function.

In medical terms, "gels" are semi-solid colloidal systems in which a solid phase is dispersed in a liquid medium. They have a viscous consistency and can be described as a cross between a solid and a liquid. The solid particles, called the gel network, absorb and swell with the liquid component, creating a system that has properties of both solids and liquids.

Gels are widely used in medical applications such as wound dressings, drug delivery systems, and tissue engineering due to their unique properties. They can provide a moist environment for wounds to heal, control the release of drugs over time, and mimic the mechanical properties of natural tissues.

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.

Collagen type VII is a type of collagen that is a major component of the anchoring fibrils, which are structures that help to attach the epidermis (the outermost layer of the skin) to the dermis (the layer of skin directly below the epidermis). Collagen type VII is composed of three identical chains that are encoded by the COL7A1 gene. Mutations in this gene can lead to a group of inherited blistering disorders known as autosomal recessive dystrophic epidermolysis bullosa, which is characterized by fragile skin and mucous membranes that blister and tear easily, often from minor trauma or friction.

Hereditary nephritis is a genetic disorder that causes recurring inflammation of the kidneys' glomeruli, which are the tiny blood vessel clusters that filter waste from the blood. This condition is also known as hereditary glomerulonephritis.

The inherited form of nephritis is caused by mutations in specific genes, leading to abnormalities in the proteins responsible for maintaining the structural integrity and proper functioning of the glomeruli. As a result, affected individuals typically experience hematuria (blood in urine), proteinuria (protein in urine), hypertension (high blood pressure), and progressive kidney dysfunction that can ultimately lead to end-stage renal disease (ESRD).

There are different types of hereditary nephritis, such as Alport syndrome and thin basement membrane nephropathy. These conditions have distinct genetic causes, clinical presentations, and inheritance patterns. Early diagnosis and appropriate management can help slow the progression of kidney damage and improve long-term outcomes for affected individuals.

Hydroxylysine is a modified form of the amino acid lysine, which is formed by the addition of a hydroxyl group (-OH) to the lysine molecule. This process is known as hydroxylation and is catalyzed by the enzyme lysyl hydroxylase.

In the human body, hydroxylysine is an important component of collagen, which is a protein that provides structure and strength to tissues such as skin, tendons, ligaments, and bones. Hydroxylysine helps to stabilize the triple-helix structure of collagen by forming cross-links between individual collagen molecules.

Abnormalities in hydroxylysine metabolism can lead to various connective tissue disorders, such as Ehlers-Danlos syndrome and osteogenesis imperfecta, which are characterized by joint hypermobility, skin fragility, and bone fractures.

Transforming Growth Factor-beta 1 (TGF-β1) is a cytokine that belongs to the TGF-β superfamily. It is a multifunctional protein involved in various cellular processes, including cell growth, differentiation, apoptosis, and extracellular matrix production. TGF-β1 plays crucial roles in embryonic development, tissue homeostasis, and repair, as well as in pathological conditions such as fibrosis and cancer. It signals through a heteromeric complex of type I and type II serine/threonine kinase receptors, leading to the activation of intracellular signaling pathways, primarily the Smad-dependent pathway. TGF-β1 has context-dependent functions, acting as a tumor suppressor in normal and early-stage cancer cells but promoting tumor progression and metastasis in advanced cancers.

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).

Gelatinases are a group of matrix metalloproteinases (MMPs) that have the ability to degrade gelatin, which is denatured collagen. There are two main types of gelatinases: MMP-2 (gelatinase A) and MMP-9 (gelatinase B). These enzymes play important roles in various physiological processes such as tissue remodeling and wound healing, but they have also been implicated in several pathological conditions, including cancer, cardiovascular diseases, and neurological disorders.

MMP-2 is produced by a variety of cells, including fibroblasts, endothelial cells, and immune cells. It plays a crucial role in angiogenesis (the formation of new blood vessels) and tumor cell invasion and metastasis. MMP-9 is primarily produced by inflammatory cells such as neutrophils and macrophages, and it has been associated with the degradation of the extracellular matrix during inflammation and tissue injury.

Both MMP-2 and MMP-9 are synthesized as inactive zymogens and require activation by other proteases or physicochemical factors before they can exert their enzymatic activity. The regulation of gelatinase activity is tightly controlled at multiple levels, including gene expression, protein synthesis, secretion, activation, and inhibition. Dysregulation of gelatinase activity has been linked to various diseases, making them attractive targets for therapeutic intervention.

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

Immunoenzyme techniques are a group of laboratory methods used in immunology and clinical chemistry that combine the specificity of antibody-antigen reactions with the sensitivity and amplification capabilities of enzyme reactions. These techniques are primarily used for the detection, quantitation, or identification of various analytes (such as proteins, hormones, drugs, viruses, or bacteria) in biological samples.

In immunoenzyme techniques, an enzyme is linked to an antibody or antigen, creating a conjugate. This conjugate then interacts with the target analyte in the sample, forming an immune complex. The presence and amount of this immune complex can be visualized or measured by detecting the enzymatic activity associated with it.

There are several types of immunoenzyme techniques, including:

1. Enzyme-linked Immunosorbent Assay (ELISA): A widely used method for detecting and quantifying various analytes in a sample. In ELISA, an enzyme is attached to either the capture antibody or the detection antibody. After the immune complex formation, a substrate is added that reacts with the enzyme, producing a colored product that can be measured spectrophotometrically.
2. Immunoblotting (Western blot): A method used for detecting specific proteins in a complex mixture, such as a protein extract from cells or tissues. In this technique, proteins are separated by gel electrophoresis and transferred to a membrane, where they are probed with an enzyme-conjugated antibody directed against the target protein.
3. Immunohistochemistry (IHC): A method used for detecting specific antigens in tissue sections or cells. In IHC, an enzyme-conjugated primary or secondary antibody is applied to the sample, and the presence of the antigen is visualized using a chromogenic substrate that produces a colored product at the site of the antigen-antibody interaction.
4. Immunofluorescence (IF): A method used for detecting specific antigens in cells or tissues by employing fluorophore-conjugated antibodies. The presence of the antigen is visualized using a fluorescence microscope.
5. Enzyme-linked immunosorbent assay (ELISA): A method used for detecting and quantifying specific antigens or antibodies in liquid samples, such as serum or culture supernatants. In ELISA, an enzyme-conjugated detection antibody is added after the immune complex formation, and a substrate is added that reacts with the enzyme to produce a colored product that can be measured spectrophotometrically.

These techniques are widely used in research and diagnostic laboratories for various applications, including protein characterization, disease diagnosis, and monitoring treatment responses.

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

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

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

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

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

Connective tissue is a type of biological tissue that provides support, strength, and protection to various structures in the body. It is composed of cells called fibroblasts, which produce extracellular matrix components such as collagen, elastin, and proteoglycans. These components give connective tissue its unique properties, including tensile strength, elasticity, and resistance to compression.

There are several types of connective tissue in the body, each with its own specific functions and characteristics. Some examples include:

1. Loose or Areolar Connective Tissue: This type of connective tissue is found throughout the body and provides cushioning and support to organs and other structures. It contains a large amount of ground substance, which allows for the movement and gliding of adjacent tissues.
2. Dense Connective Tissue: This type of connective tissue has a higher concentration of collagen fibers than loose connective tissue, making it stronger and less flexible. Dense connective tissue can be further divided into two categories: regular (or parallel) and irregular. Regular dense connective tissue, such as tendons and ligaments, has collagen fibers that run parallel to each other, providing great tensile strength. Irregular dense connective tissue, such as the dermis of the skin, has collagen fibers arranged in a more haphazard pattern, providing support and flexibility.
3. Adipose Tissue: This type of connective tissue is primarily composed of fat cells called adipocytes. Adipose tissue serves as an energy storage reservoir and provides insulation and cushioning to the body.
4. Cartilage: A firm, flexible type of connective tissue that contains chondrocytes within a matrix of collagen and proteoglycans. Cartilage is found in various parts of the body, including the joints, nose, ears, and trachea.
5. Bone: A specialized form of connective tissue that consists of an organic matrix (mainly collagen) and an inorganic mineral component (hydroxyapatite). Bone provides structural support to the body and serves as a reservoir for calcium and phosphate ions.
6. Blood: Although not traditionally considered connective tissue, blood does contain elements of connective tissue, such as plasma proteins and leukocytes (white blood cells). Blood transports nutrients, oxygen, hormones, and waste products throughout the body.

Metalloendopeptidases are a type of enzymes that cleave peptide bonds in proteins, specifically at interior positions within the polypeptide chain. They require metal ions as cofactors for their catalytic activity, typically zinc (Zn2+) or cobalt (Co2+). These enzymes play important roles in various biological processes such as protein degradation, processing, and signaling. Examples of metalloendopeptidases include thermolysin, matrix metalloproteinases (MMPs), and neutrophil elastase.

Osteogenesis Imperfecta (OI), also known as brittle bone disease, is a group of genetic disorders that mainly affect the bones. It is characterized by bones that break easily, often from little or no apparent cause. This happens because the body produces an insufficient amount of collagen or poor quality collagen, which are crucial for the formation of healthy bones.

The severity of OI can vary greatly, even within the same family. Some people with OI have only a few fractures in their lifetime while others may have hundreds. Other symptoms can include blue or gray sclera (the white part of the eye), hearing loss, short stature, curved or bowed bones, loose joints, and a triangular face shape.

There are several types of OI, each caused by different genetic mutations. Most types of OI are inherited in an autosomal dominant pattern, meaning only one copy of the altered gene is needed to cause the condition. However, some types are inherited in an autosomal recessive pattern, which means that two copies of the altered gene must be present for the condition to occur.

There is no cure for OI, but treatment can help manage symptoms and prevent complications. Treatment may include medication to strengthen bones, physical therapy, bracing, and surgery.

A peptide fragment is a short chain of amino acids that is derived from a larger peptide or protein through various biological or chemical processes. These fragments can result from the natural breakdown of proteins in the body during regular physiological processes, such as digestion, or they can be produced experimentally in a laboratory setting for research or therapeutic purposes.

Peptide fragments are often used in research to map the structure and function of larger peptides and proteins, as well as to study their interactions with other molecules. In some cases, peptide fragments may also have biological activity of their own and can be developed into drugs or diagnostic tools. For example, certain peptide fragments derived from hormones or neurotransmitters may bind to receptors in the body and mimic or block the effects of the full-length molecule.

Fimbriae proteins are specialized protein structures found on the surface of certain bacteria, including some pathogenic species. Fimbriae, also known as pili, are thin, hair-like appendages that extend from the bacterial cell wall and play a role in the attachment of the bacterium to host cells or surfaces.

Fimbrial proteins are responsible for the assembly and structure of these fimbriae. They are produced by the bacterial cell and then self-assemble into long, thin fibers that extend from the surface of the bacterium. The proteins have a highly conserved sequence at their carboxy-terminal end, which is important for their polymerization and assembly into fimbriae.

Fimbrial proteins can vary widely between different species of bacteria, and even between strains of the same species. Some fimbrial proteins are adhesins, meaning they bind to specific receptors on host cells, allowing the bacterium to attach to and colonize tissues. Other fimbrial proteins may play a role in biofilm formation or other aspects of bacterial pathogenesis.

Understanding the structure and function of fimbrial proteins is important for developing new strategies to prevent or treat bacterial infections, as these proteins can be potential targets for vaccines or therapeutic agents.

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

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

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

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

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

Integrin α1β1, also known as Very Late Antigen-1 (VLA-1) or CD49a/CD29, is a heterodimeric transmembrane receptor protein composed of α1 and β1 subunits. It belongs to the integrin family of adhesion molecules that play crucial roles in cell-cell and cell-extracellular matrix (ECM) interactions.

Integrin α1β1 is primarily expressed on various cell types, including fibroblasts, endothelial cells, smooth muscle cells, and some immune cells. This integrin binds to several ECM proteins, such as collagens (type I, II, III, IV), laminin, and fibronectin, mediating cell adhesion, migration, proliferation, differentiation, and survival. Additionally, α1β1 integrin has been implicated in various physiological and pathological processes, such as tissue repair, fibrosis, and tumor progression.

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.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

The endothelium is a thin layer of simple squamous epithelial cells that lines the interior surface of blood vessels, lymphatic vessels, and heart chambers. The vascular endothelium, specifically, refers to the endothelial cells that line the blood vessels. These cells play a crucial role in maintaining vascular homeostasis by regulating vasomotor tone, coagulation, platelet activation, inflammation, and permeability of the vessel wall. They also contribute to the growth and repair of the vascular system and are involved in various pathological processes such as atherosclerosis, hypertension, and diabetes.

Elastin is a protein that provides elasticity to tissues and organs, allowing them to resume their shape after stretching or contracting. It is a major component of the extracellular matrix in many tissues, including the skin, lungs, blood vessels, and ligaments. Elastin fibers can stretch up to 1.5 times their original length and then return to their original shape due to the unique properties of this protein. The elastin molecule is made up of cross-linked chains of the protein tropoelastin, which are produced by cells called fibroblasts and then assembled into larger elastin fibers by enzymes called lysyl oxidases. Elastin has a very long half-life, with some estimates suggesting that it can remain in the body for up to 70 years or more.

The Descemet membrane is the thin, transparent basement membrane that is produced by the corneal endothelial cells. It is located between the corneal stroma and the corneal endothelium, which is the innermost layer of the cornea. The Descemet membrane provides structural support for the corneal endothelium and helps to maintain the proper hydration and clarity of the cornea. It is named after the French physician Jean Descemet, who first described it in 1752.

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as 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.

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

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.

Hyperlipoproteinemia Type IV is a genetic disorder characterized by an increased level of very low-density lipoproteins (VLDL) in the blood. This leads to elevated levels of triglycerides, which are a type of fat found in the blood. The condition is also sometimes referred to as "Fredrickson Type IV."

People with Hyperlipoproteinemia Type IV have an increased risk of developing pancreatitis, a potentially life-threatening inflammation of the pancreas, due to high levels of triglycerides. They may also have an increased risk of cardiovascular disease due to elevated levels of VLDL and other atherogenic lipoproteins.

The condition is usually inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the disorder if one parent has it. However, some cases may be caused by mutations in multiple genes or by environmental factors such as obesity, diabetes, and excessive alcohol consumption.

Treatment for Hyperlipoproteinemia Type IV typically involves lifestyle modifications such as weight loss, exercise, and dietary changes to reduce triglyceride levels. In some cases, medication may be necessary to control the condition.

The cornea is the clear, dome-shaped surface at the front of the eye. It plays a crucial role in focusing vision. The cornea protects the eye from harmful particles and microorganisms, and it also serves as a barrier against UV light. Its transparency allows light to pass through and get focused onto the retina. The cornea does not contain blood vessels, so it relies on tears and the fluid inside the eye (aqueous humor) for nutrition and oxygen. Any damage or disease that affects its clarity and shape can significantly impact vision and potentially lead to blindness if left untreated.

Glycosaminoglycans (GAGs) are long, unbranched polysaccharides composed of repeating disaccharide units. They are a major component of the extracellular matrix and connective tissues in the body. GAGs are negatively charged due to the presence of sulfate and carboxyl groups, which allows them to attract positively charged ions and water molecules, contributing to their ability to retain moisture and maintain tissue hydration and elasticity.

GAGs can be categorized into four main groups: heparin/heparan sulfate, chondroitin sulfate/dermatan sulfate, keratan sulfate, and hyaluronic acid. These different types of GAGs have varying structures and functions in the body, including roles in cell signaling, inflammation, and protection against enzymatic degradation.

Heparin is a highly sulfated form of heparan sulfate that is found in mast cells and has anticoagulant properties. Chondroitin sulfate and dermatan sulfate are commonly found in cartilage and contribute to its resiliency and ability to withstand compressive forces. Keratan sulfate is found in corneas, cartilage, and bone, where it plays a role in maintaining the structure and function of these tissues. Hyaluronic acid is a large, nonsulfated GAG that is widely distributed throughout the body, including in synovial fluid, where it provides lubrication and shock absorption for joints.

Glycogen Storage Disease Type IV (GSD IV), also known as Andersen's disease, is a rare inherited metabolic disorder that affects the body's ability to break down glycogen, a complex carbohydrate that serves as a source of energy for the body.

In GSD IV, there is a deficiency in the enzyme called glycogen branching enzyme (GBE), which is responsible for adding branches to the glycogen molecule during its synthesis. This results in an abnormal form of glycogen that accumulates in various organs and tissues, particularly in the liver, heart, and muscles.

The accumulation of this abnormal glycogen can lead to progressive damage and failure of these organs, resulting in a variety of symptoms such as muscle weakness, hypotonia, hepatomegaly (enlarged liver), cardiomyopathy (heart muscle disease), and developmental delay. The severity of the disease can vary widely, with some individuals experiencing milder symptoms while others may have a more severe and rapidly progressing form of the disorder.

Currently, there is no cure for GSD IV, and treatment is focused on managing the symptoms and slowing down the progression of the disease. This may include providing nutritional support, addressing specific organ dysfunction, and preventing complications.

Medical Definition of Matrix Metalloproteinase 1 (MMP-1):

Matrix metalloproteinase 1, also known as collagenase-1 or fibroblast collagenase, is a member of the matrix metalloproteinase family of enzymes. These enzymes are involved in degrading and remodeling extracellular matrix components, such as collagens, gelatins, and other proteins. MMP-1 specifically targets interstitial collagens (types I, II, III, VII, and X) and plays a crucial role in tissue repair, wound healing, and pathological processes like tumor invasion and metastasis. It is secreted as an inactive proenzyme and requires activation before it can carry out its proteolytic functions. MMP-1 activity is regulated at various levels, including transcription, activation, and inhibition by endogenous tissue inhibitors of metalloproteinases (TIMPs). Dysregulation of MMP-1 has been implicated in several diseases, such as arthritis, cancer, and fibrosis.

Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase is an enzyme that plays a crucial role in the biosynthesis of collagen. The medical definition of this enzyme is:

"An enzyme that catalyzes the post-translational modification of specific lysine residues in procollagens and related proteins. This enzyme requires Fe2+, 2-oxoglutarate, molecular oxygen, and ascorbic acid as cofactors. It hydroxylates certain lysine residues to form hydroxylysine, which is essential for the stabilization of collagen triple helices and for the formation of covalent cross-links between individual collagen molecules. Mutations in this gene have been associated with several types of Ehlers-Danlos syndrome."

The systematic name for this enzyme is "procollagen-lysine, 2-oxoglutarate 5-dioxygenase (hydroxylating)." It is also known as "procollagen-lysine, lysine hydroxylase," or simply "LH." This enzyme is responsible for the hydroxylation of specific lysine residues in procollagens and related proteins during their biosynthesis. The hydroxylation reaction catalyzed by this enzyme involves the incorporation of a hydroxyl group (-OH) into the lysine side chain, resulting in the formation of hydroxylysine. This modification is essential for the proper folding and stabilization of collagen molecules, as well as for their subsequent cross-linking and assembly into extracellular matrix structures.

Defects or mutations in the gene encoding this enzyme can lead to various types of Ehlers-Danlos syndrome (EDS), a group of heritable connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility.

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.

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

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

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

Aggrecan is a large, complex proteoglycan molecule found in the extracellular matrix of articular cartilage and other connective tissues. It is a key component of the structural framework of these tissues, helping to provide resiliency, cushioning, and protection to the cells within. Aggrecan contains numerous glycosaminoglycan (GAG) chains, which are negatively charged molecules that attract water and ions, creating a swelling pressure that contributes to the tissue's load-bearing capacity.

The medical definition of 'Aggrecans' can be described as:

1. A large proteoglycan molecule found in articular cartilage and other connective tissues.
2. Composed of a core protein with attached glycosaminoglycan (GAG) chains, primarily chondroitin sulfate and keratan sulfate.
3. Plays a crucial role in the biomechanical properties of articular cartilage by attracting water and ions, creating a swelling pressure that contributes to the tissue's load-bearing capacity.
4. Aggrecan degradation or loss is associated with various joint diseases, such as osteoarthritis, due to reduced structural integrity and shock-absorbing capabilities of articular cartilage.

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).

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.

Ehlers-Danlos syndrome (EDS) is a group of inherited disorders that affect connective tissues, which are the proteins and chemicals in the body that provide structure and support for skin, bones, blood vessels, and other organs. People with EDS have stretching (elastic) skin and joints that are too loose (hypermobile). There are several types of EDS, each with its own set of symptoms and level of severity. Some of the more common types include:

* Classical EDS: This type is characterized by skin that can be stretched far beyond normal and bruises easily. Affected individuals may also have joints that dislocate easily.
* Hypermobile EDS: This type is marked by joint hypermobility, which can lead to frequent dislocations and subluxations (partial dislocations). Some people with this type of EDS also have Marfan syndrome-like features, such as long fingers and a curved spine.
* Vascular EDS: This type is caused by changes in the COL3A1 gene and is characterized by thin, fragile skin that tears or bruises easily. People with vascular EDS are at risk of serious complications, such as arterial rupture and organ perforation.
* Kyphoscoliosis EDS: This type is marked by severe kyphoscoliosis (a forward curvature of the spine) and joint laxity. Affected individuals may also have fragile skin that tears or bruises easily.

EDS is typically inherited in an autosomal dominant manner, meaning that a person only needs to inherit one copy of the altered gene from either parent to develop the condition. However, some types of EDS are inherited in an autosomal recessive manner, which means that a person must inherit two copies of the altered gene (one from each parent) to develop the condition.

There is no cure for EDS, and treatment is focused on managing symptoms and preventing complications. This may include physical therapy to strengthen muscles and improve joint stability, bracing to support joints, and surgery to repair damaged tissues or organs.

Gelatin is not strictly a medical term, but it is often used in medical contexts. Medically, gelatin is recognized as a protein-rich substance that is derived from collagen, which is found in the skin, bones, and connective tissue of animals. It is commonly used in the production of various medical and pharmaceutical products such as capsules, wound dressings, and drug delivery systems due to its biocompatibility and ability to form gels.

In a broader sense, gelatin is a translucent, colorless, flavorless food ingredient that is derived from collagen through a process called hydrolysis. It is widely used in the food industry as a gelling agent, thickener, stabilizer, and texturizer in various foods such as candies, desserts, marshmallows, and yogurts.

It's worth noting that while gelatin has many uses, it may not be suitable for vegetarians or those with dietary restrictions since it is derived from animal products.

Platelet adhesiveness refers to the ability of platelets, which are small blood cells that help your body form clots to prevent excessive bleeding, to stick to other cells or surfaces. This process is crucial in hemostasis, the process of stopping bleeding after injury to a blood vessel.

When the endothelium (the lining of blood vessels) is damaged, subendothelial structures are exposed, which can trigger platelet adhesion. Platelets then change shape and release chemical signals that cause other platelets to clump together, forming a platelet plug. This plug helps to seal the damaged vessel and prevent further bleeding.

Platelet adhesiveness is influenced by several factors, including the presence of von Willebrand factor (vWF), a protein in the blood that helps platelets bind to damaged vessels, and the expression of glycoprotein receptors on the surface of platelets. Abnormalities in platelet adhesiveness can lead to bleeding disorders or thrombotic conditions.

Fibril-Associated Collagens (also known as FACIT collagens) are a group of collagen proteins that are characterized by their association with the surface of collagen fibrils. They play a role in the organization, stability, and diameter regulation of collagen fibrils. These collagens include types XII, XIV, XVI, XIX, XXI, and XXII.

Type XII collagen is found in various tissues such as tendons, ligaments, skin, and cornea. It has a triple-helical domain that interacts with the surface of collagen fibrils and a non-collagenous domain that can bind to other extracellular matrix proteins.

Type XIV collagen is also found in various tissues and has a similar structure to type XII collagen, but it has a larger non-collagenous domain. It plays a role in regulating the diameter of collagen fibrils.

Type XVI collagen is primarily found in cartilage and has a unique structure with multiple interruptions in its triple-helical domain. It is involved in the regulation of collagen fibrillogenesis and may also have roles in cell adhesion and signaling.

Types XIX and XXI collagens are similar to each other and are found in various tissues, including skin, tendons, and blood vessels. They have a short triple-helical domain and large non-collagenous domains that contain multiple binding sites for other extracellular matrix proteins.

Type XXII collagen is primarily found in the cornea and has a similar structure to type XIX collagen. It plays a role in regulating the diameter of collagen fibrils and may also have roles in cell adhesion and signaling.

Wound healing is a complex and dynamic process that occurs after tissue injury, aiming to restore the integrity and functionality of the damaged tissue. It involves a series of overlapping phases: hemostasis, inflammation, proliferation, and remodeling.

1. Hemostasis: This initial phase begins immediately after injury and involves the activation of the coagulation cascade to form a clot, which stabilizes the wound and prevents excessive blood loss.
2. Inflammation: Activated inflammatory cells, such as neutrophils and monocytes/macrophages, infiltrate the wound site to eliminate pathogens, remove debris, and release growth factors that promote healing. This phase typically lasts for 2-5 days post-injury.
3. Proliferation: In this phase, various cell types, including fibroblasts, endothelial cells, and keratinocytes, proliferate and migrate to the wound site to synthesize extracellular matrix (ECM) components, form new blood vessels (angiogenesis), and re-epithelialize the wounded area. This phase can last up to several weeks depending on the size and severity of the wound.
4. Remodeling: The final phase of wound healing involves the maturation and realignment of collagen fibers, leading to the restoration of tensile strength in the healed tissue. This process can continue for months to years after injury, although the tissue may never fully regain its original structure and function.

It is important to note that wound healing can be compromised by several factors, including age, nutrition, comorbidities (e.g., diabetes, vascular disease), and infection, which can result in delayed healing or non-healing chronic wounds.

Urokinase-type plasminogen activator (uPA) is a serine protease enzyme that plays a crucial role in the degradation of the extracellular matrix and cell migration. It catalyzes the conversion of plasminogen to plasmin, which then breaks down various proteins in the extracellular matrix, leading to tissue remodeling and repair.

uPA is synthesized as a single-chain molecule, pro-uPA, which is activated by cleavage into two chains, forming the mature and active enzyme. uPA binds to its specific receptor, uPAR, on the cell surface, where it exerts its proteolytic activity.

Abnormal regulation of uPA and uPAR has been implicated in various pathological conditions, including cancer, where they contribute to tumor invasion and metastasis. Therefore, uPA is a potential target for therapeutic intervention in cancer and other diseases associated with excessive extracellular matrix degradation.

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

Cyanogen bromide is a solid compound with the chemical formula (CN)Br. It is a highly reactive and toxic substance that is used in research and industrial settings for various purposes, such as the production of certain types of resins and gels. Cyanogen bromide is an alkyl halide, which means it contains a bromine atom bonded to a carbon atom that is also bonded to a cyano group (a nitrogen atom bonded to a carbon atom with a triple bond).

Cyanogen bromide is classified as a class B poison, which means it can cause harm or death if swallowed, inhaled, or absorbed through the skin. It can cause irritation and burns to the eyes, skin, and respiratory tract, and prolonged exposure can lead to more serious health effects, such as damage to the nervous system and kidneys. Therefore, it is important to handle cyanogen bromide with care and to use appropriate safety precautions when working with it.

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.

The corneal stroma, also known as the substantia propria, is the thickest layer of the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea plays a crucial role in focusing vision.

The corneal stroma makes up about 90% of the cornea's thickness and is composed of parallel bundles of collagen fibers that are arranged in regular, repeating patterns. These fibers give the cornea its strength and transparency. The corneal stroma also contains a small number of cells called keratocytes, which produce and maintain the collagen fibers.

Disorders that affect the corneal stroma can cause vision loss or other eye problems. For example, conditions such as keratoconus, in which the cornea becomes thin and bulges outward, can distort vision and make it difficult to see clearly. Other conditions, such as corneal scarring or infection, can also affect the corneal stroma and lead to vision loss or other eye problems.

Proline is an organic compound that is classified as a non-essential amino acid, meaning it can be produced by the human body and does not need to be obtained through the diet. It is encoded in the genetic code as the codon CCU, CCC, CCA, or CCG. Proline is a cyclic amino acid, containing an unusual secondary amine group, which forms a ring structure with its carboxyl group.

In proteins, proline acts as a structural helix breaker, disrupting the alpha-helix structure and leading to the formation of turns and bends in the protein chain. This property is important for the proper folding and function of many proteins. Proline also plays a role in the stability of collagen, a major structural protein found in connective tissues such as tendons, ligaments, and skin.

In addition to its role in protein structure, proline has been implicated in various cellular processes, including signal transduction, apoptosis, and oxidative stress response. It is also a precursor for the synthesis of other biologically important compounds such as hydroxyproline, which is found in collagen and elastin, and glutamate, an excitatory neurotransmitter in the brain.

A Tissue Inhibitor of Metalloproteinases (TIMPs) is a group of four naturally occurring proteins that play a crucial role in the regulation of extracellular matrix (ECM) remodeling. They function by inhibiting Matrix Metalloproteinases (MMPs), which are a family of enzymes responsible for degrading various components of the ECM, such as collagen and elastin.

By controlling MMP activity, TIMPs help maintain the balance between ECM synthesis and degradation, thereby ensuring proper tissue structure and function. An imbalance in TIMPs and MMPs has been implicated in various pathological conditions, including fibrosis, cancer, and inflammatory diseases.

There are four known TIMPs: TIMP1, TIMP2, TIMP3, and TIMP4, each with distinct expression patterns and substrate specificities. They not only inhibit MMPs but also have other functions, such as promoting cell survival, modulating cell growth and differentiation, and regulating angiogenesis.

Tissue Inhibitor of Metalloproteinase-1 (TIMP-1) is a protein that inhibits the activity of matrix metalloproteinases (MMPs), which are enzymes responsible for breaking down extracellular matrix proteins. TIMP-1 plays a crucial role in regulating the balance between the synthesis and degradation of the extracellular matrix, thereby maintaining tissue homeostasis. It is involved in various biological processes, including cell growth, differentiation, and apoptosis (programmed cell death). An imbalance between MMPs and TIMPs has been implicated in several pathological conditions, such as cancer, fibrosis, and inflammatory diseases.

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

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

The primary functions of tissue scaffolds include:

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

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

Non-fibrillar collagens are a type of collagen that do not form fibrous structures, unlike the more common fibrillar collagens. They are a group of structurally diverse collagens that play important roles in various biological processes such as cell adhesion, migration, and differentiation. Non-fibrillar collagens include types IV, VI, VIII, X, XII, XIV, XVI, XIX, XXI, and XXVIII. They are often found in basement membranes and other specialized extracellular matrix structures.

Type IV collagen is a major component of the basement membrane and forms a network-like structure that provides a scaffold for other matrix components. Type VI collagen has a beaded filament structure and is involved in the organization of the extracellular matrix. Type VIII collagen is found in the eyes and helps to maintain the structural integrity of the eye. Type X collagen is associated with cartilage development and bone formation. Type XII and XIV collagens are fibril-associated collagens that help to regulate the organization and diameter of fibrillar collagens. The other non-fibrillar collagens have various functions, including cell adhesion, migration, and differentiation.

Overall, non-fibrillar collagens are important structural components of the extracellular matrix and play critical roles in various biological processes.

"Bone" is the hard, dense connective tissue that makes up the skeleton of vertebrate animals. It provides support and protection for the body's internal organs, and serves as a attachment site for muscles, tendons, and ligaments. Bone is composed of cells called osteoblasts and osteoclasts, which are responsible for bone formation and resorption, respectively, and an extracellular matrix made up of collagen fibers and mineral crystals.

Bones can be classified into two main types: compact bone and spongy bone. Compact bone is dense and hard, and makes up the outer layer of all bones and the shafts of long bones. Spongy bone is less dense and contains large spaces, and makes up the ends of long bones and the interior of flat and irregular bones.

The human body has 206 bones in total. They can be further classified into five categories based on their shape: long bones, short bones, flat bones, irregular bones, and sesamoid bones.

Biglycan is a type of small leucine-rich proteoglycan (SLRP) that is found in the extracellular matrix of various tissues, including bone, cartilage, and tendons. It plays important roles in the organization and stabilization of the extracellular matrix, as well as in the regulation of cell behavior and signaling pathways.

Biglycan is composed of a core protein and one or more glycosaminoglycan (GAG) chains, which are long, unbranched polysaccharides made up of repeating disaccharide units. The GAG chains attach to the core protein via specific serine residues, forming a proteoglycan.

In addition to its structural roles, biglycan has been shown to interact with various growth factors and cytokines, modulating their activity and influencing cellular responses such as proliferation, differentiation, and migration. Dysregulation of biglycan expression or function has been implicated in several diseases, including osteoarthritis, cancer, and fibrosis.

I'm happy to help! However, I believe there may be a slight misunderstanding in your question. "Pili" is a Filipino word that means "hair," and it is not a medical term. On the other hand, "sex" is a broad term that refers to various biological and social characteristics related to males and females.

If you are asking for a medical definition related to hair and sex, there are several possible options depending on the context. For example, hirsutism is a medical condition where women have excessive hair growth in a male-like pattern, such as on the face, chest, or back. This condition can be caused by hormonal imbalances or genetic factors.

If you could provide more context or clarify your question, I would be happy to try and give you a more specific answer!

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.

Experimental arthritis refers to the induction of joint inflammation in animal models for the purpose of studying the disease process and testing potential treatments. This is typically achieved through the use of various methods such as injecting certain chemicals or proteins into the joints, genetically modifying animals to develop arthritis-like symptoms, or immunizing animals to induce an autoimmune response against their own joint tissues. These models are crucial for advancing our understanding of the underlying mechanisms of arthritis and for developing new therapies to treat this debilitating disease.

Integrin α1 (also known as ITGA1 or CD49a) is a subunit of a heterodimeric integrin receptor, specifically the collagen receptor α1β1. Integrins are transmembrane proteins that play crucial roles in cell-cell and cell-extracellular matrix (ECM) adhesion, signaling, migration, proliferation, and differentiation. The α1β1 integrin binds to various collagen types, such as collagens I, II, III, and V, and mediates cellular responses upon binding to these ECM components.

The gene encoding Integrin α1 is located on chromosome 5 (5q31) in humans. Mutations in the ITGA1 gene can lead to various diseases, including leukocyte adhesion deficiency type II and some forms of epidermolysis bullosa.

Collagen type XIII, also known as alpha-1(XIII) collagen or COL13A1, is a type of collagen that is found in the extracellular matrix of various tissues, including skin, blood vessels, and the eye. It is a homotrimeric protein composed of three identical alpha-1(XIII) chains.

Collagen type XIII has a unique structure, with a short triple-helical domain and a large non-collagenous domain that contains several functional domains, including a von Willebrand factor A (vWA) domain, a thrombospondin type 1 (TSR) domain, and a C-terminal domain.

Collagen type XIII is involved in various biological processes, such as cell adhesion, migration, and differentiation. It has been shown to interact with other extracellular matrix proteins, such as collagens IV and VII, laminin-5, and fibronectin, as well as with integrins and growth factors.

Mutations in the COL13A1 gene have been associated with various human diseases, including dystrophic epidermolysis bullosa, a group of inherited skin fragility disorders characterized by blistering and scarring of the skin and mucous membranes.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Matrix metalloproteinases (MMPs) are a group of enzymes responsible for the degradation and remodeling of the extracellular matrix, the structural framework of most tissues in the body. These enzymes play crucial roles in various physiological processes such as tissue repair, wound healing, and embryonic development. They also participate in pathological conditions like tumor invasion, metastasis, and inflammatory diseases by breaking down the components of the extracellular matrix, including collagens, elastins, proteoglycans, and gelatins. MMPs are zinc-dependent endopeptidases that require activation from their proenzyme form to become fully functional. Their activity is tightly regulated at various levels, including gene expression, protein synthesis, and enzyme inhibition by tissue inhibitors of metalloproteinases (TIMPs). Dysregulation of MMPs has been implicated in several diseases, making them potential therapeutic targets for various clinical interventions.

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.

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.

Quinazolinones are a class of organic compounds that contain a quinazolinone core structure. Quinazolinone is a heterocyclic compound made up of a quinazoline ring fused to a ketone group. This structure contains nitrogen atoms at positions 1, 3, and 9 of the fused benzene and pyridine rings.

Quinazolinones have various biological activities, including anti-cancer, anti-malarial, anti-inflammatory, and kinase inhibitor properties. They are used as building blocks in the synthesis of pharmaceuticals and other organic compounds. Some drugs containing quinazolinone moieties include the chemotherapy agent gefitinib (Iressa) and the antimalarial drug chloroquine.

It is important to note that Quinazolinones are not a medication themselves, but rather a class of organic compounds with various potential medical applications.

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.

Chondroitin sulfate proteoglycans (CSPGs) are complex molecules found in the extracellular matrix of various connective tissues, including cartilage. They are composed of a core protein covalently linked to one or more glycosaminoglycan (GAG) chains, such as chondroitin sulfate and dermatan sulfate.

CSPGs play important roles in the structure and function of tissues, including:

1. Regulating water content and providing resilience to tissues due to their high negative charge, which attracts cations and bound water molecules.
2. Interacting with other matrix components, such as collagen and elastin, to form a highly organized network that provides tensile strength and elasticity.
3. Modulating cell behavior by interacting with various growth factors, cytokines, and cell surface receptors, thereby influencing processes like cell adhesion, proliferation, differentiation, and migration.
4. Contributing to the maintenance of the extracellular matrix homeostasis through their involvement in matrix turnover and remodeling.

In articular cartilage, CSPGs are particularly abundant and contribute significantly to its load-bearing capacity and overall health. Dysregulation of CSPGs has been implicated in various pathological conditions, such as osteoarthritis, where altered proteoglycan composition and content can lead to cartilage degradation and joint dysfunction.

Procollagen-proline dioxygenase is an enzyme that belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with oxygen as an acceptor. This enzyme is involved in the post-translational modification of procollagens, which are the precursors of collagen, a crucial protein found in connective tissues such as tendons, ligaments, and skin.

Procollagen-proline dioxygenase catalyzes the reaction that adds two hydroxyl groups to specific proline residues in the procollagen molecule, converting them into hydroxyprolines. This modification is essential for the proper folding and stabilization of the collagen triple helix structure, which provides strength and resilience to connective tissues.

The enzyme requires iron as a cofactor and molecular oxygen as a substrate, with vitamin C (ascorbic acid) acting as an essential cofactor in the reaction cycle. The proper functioning of procollagen-proline dioxygenase is critical for maintaining the integrity and health of connective tissues, and deficiencies or mutations in this enzyme can lead to various connective tissue disorders, such as scurvy (caused by vitamin C deficiency) or certain forms of osteogenesis imperfecta (a genetic disorder characterized by fragile bones).

Osteogenesis is the process of bone formation or development. It involves the differentiation and maturation of osteoblasts, which are bone-forming cells that synthesize and deposit the organic matrix of bone tissue, composed mainly of type I collagen. This organic matrix later mineralizes to form the inorganic crystalline component of bone, primarily hydroxyapatite.

There are two primary types of osteogenesis: intramembranous and endochondral. Intramembranous osteogenesis occurs directly within connective tissue, where mesenchymal stem cells differentiate into osteoblasts and form bone tissue without an intervening cartilage template. This process is responsible for the formation of flat bones like the skull and clavicles.

Endochondral osteogenesis, on the other hand, involves the initial development of a cartilaginous model or template, which is later replaced by bone tissue. This process forms long bones, such as those in the limbs, and occurs through several stages involving chondrocyte proliferation, hypertrophy, and calcification, followed by invasion of blood vessels and osteoblasts to replace the cartilage with bone tissue.

Abnormalities in osteogenesis can lead to various skeletal disorders and diseases, such as osteogenesis imperfecta (brittle bone disease), achondroplasia (a form of dwarfism), and cleidocranial dysplasia (a disorder affecting skull and collarbone development).

Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) is a protein that inhibits the activity of matrix metalloproteinases (MMPs), which are enzymes involved in breaking down and remodeling extracellular matrix (ECM) components. TIMP-2 specifically inhibits MMP-2, also known as gelatinase A, by forming a 1:1 complex with it.

TIMP-2 is produced by various cell types, including fibroblasts, endothelial cells, and smooth muscle cells. It plays important roles in regulating ECM turnover, tissue remodeling, and wound healing. Imbalances between MMPs and TIMPs have been implicated in several pathological conditions, such as cancer, fibrosis, and cardiovascular diseases.

In the context of cancer, increased MMP-2 activity has been associated with tumor invasion and metastasis. TIMP-2 can counteract this effect by inhibiting MMP-2, thus potentially reducing tumor progression. However, the precise role of TIMP-2 in cancer is complex and may depend on various factors, including the type of cancer and the stage of disease progression.

Osteonectin, also known as SPARC (Secreted Protein Acidic and Rich in Cysteine), is a non-collagenous protein found in the extracellular matrix of bone and other tissues. It plays a crucial role in bone mineralization, collagen fibrillogenesis, and tissue remodeling by interacting with various molecules such as collagens, growth factors, and integrins. Osteonectin is involved in regulating cell adhesion, proliferation, differentiation, and apoptosis during bone development, repair, and homeostasis.

Transmission electron microscopy (TEM) is a type of microscopy in which an electron beam is transmitted through a ultra-thin specimen, interacting with it as it passes through. An image is formed from the interaction of the electrons with the specimen; the image is then magnified and visualized on a fluorescent screen or recorded on an electronic detector (or photographic film in older models).

TEM can provide high-resolution, high-magnification images that can reveal the internal structure of specimens including cells, viruses, and even molecules. It is widely used in biological and materials science research to investigate the ultrastructure of cells, tissues and materials. In medicine, TEM is used for diagnostic purposes in fields such as virology and bacteriology.

It's important to note that preparing a sample for TEM is a complex process, requiring specialized techniques to create thin (50-100 nm) specimens. These include cutting ultrathin sections of embedded samples using an ultramicrotome, staining with heavy metal salts, and positive staining or negative staining methods.

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.

Mechanical stress, in the context of physiology and medicine, refers to any type of force that is applied to body tissues or organs, which can cause deformation or displacement of those structures. Mechanical stress can be either external, such as forces exerted on the body during physical activity or trauma, or internal, such as the pressure changes that occur within blood vessels or other hollow organs.

Mechanical stress can have a variety of effects on the body, depending on the type, duration, and magnitude of the force applied. For example, prolonged exposure to mechanical stress can lead to tissue damage, inflammation, and chronic pain. Additionally, abnormal or excessive mechanical stress can contribute to the development of various musculoskeletal disorders, such as tendinitis, osteoarthritis, and herniated discs.

In order to mitigate the negative effects of mechanical stress, the body has a number of adaptive responses that help to distribute forces more evenly across tissues and maintain structural integrity. These responses include changes in muscle tone, joint positioning, and connective tissue stiffness, as well as the remodeling of bone and other tissues over time. However, when these adaptive mechanisms are overwhelmed or impaired, mechanical stress can become a significant factor in the development of various pathological conditions.

Anti-glomerular basement membrane (anti-GBM) disease, also known as Goodpasture's disease, is a rare autoimmune disorder in which the body produces antibodies that attack the glomerular basement membrane (GBM), a component of the filtering units (glomeruli) in the kidneys. This leads to inflammation and damage to the glomeruli, causing hematuria (blood in urine), proteinuria (protein in urine), and potentially kidney failure. In some cases, anti-GBM disease may also affect the lungs, leading to coughing up blood (hemoptysis). The exact cause of anti-GBM disease is not fully understood, but it is believed to be related to both genetic and environmental factors. Treatment typically involves a combination of immunosuppressive therapy and plasma exchange.

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.

The dermis is the layer of skin located beneath the epidermis, which is the outermost layer of the skin. It is composed of connective tissue and provides structure and support to the skin. The dermis contains blood vessels, nerves, hair follicles, sweat glands, and oil glands. It is also responsible for the production of collagen and elastin, which give the skin its strength and flexibility. The dermis can be further divided into two layers: the papillary dermis, which is the upper layer and contains finger-like projections called papillae that extend upwards into the epidermis, and the reticular dermis, which is the lower layer and contains thicker collagen bundles. Together, the epidermis and dermis make up the true skin.

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

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

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

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.

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.

Tensile strength is a material property that measures the maximum amount of tensile (pulling) stress that a material can withstand before failure, such as breaking or fracturing. It is usually measured in units of force per unit area, such as pounds per square inch (psi) or pascals (Pa). In the context of medical devices or biomaterials, tensile strength may be used to describe the mechanical properties of materials used in implants, surgical tools, or other medical equipment. High tensile strength is often desirable in these applications to ensure that the material can withstand the stresses and forces it will encounter during use.

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

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

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

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

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

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

An Enzyme-Linked Immunosorbent Assay (ELISA) is a type of analytical biochemistry assay used to detect and quantify the presence of a substance, typically a protein or peptide, in a liquid sample. It takes its name from the enzyme-linked antibodies used in the assay.

In an ELISA, the sample is added to a well containing a surface that has been treated to capture the target substance. If the target substance is present in the sample, it will bind to the surface. Next, an enzyme-linked antibody specific to the target substance is added. This antibody will bind to the captured target substance if it is present. After washing away any unbound material, a substrate for the enzyme is added. If the enzyme is present due to its linkage to the antibody, it will catalyze a reaction that produces a detectable signal, such as a color change or fluorescence. The intensity of this signal is proportional to the amount of target substance present in the sample, allowing for quantification.

ELISAs are widely used in research and clinical settings to detect and measure various substances, including hormones, viruses, and bacteria. They offer high sensitivity, specificity, and reproducibility, making them a reliable choice for many applications.

Elastic tissue is a type of connective tissue found in the body that is capable of returning to its original shape after being stretched or deformed. It is composed mainly of elastin fibers, which are protein molecules with a unique structure that allows them to stretch and recoil. Elastic tissue is found in many areas of the body, including the lungs, blood vessels, and skin, where it provides flexibility and resilience.

The elastin fibers in elastic tissue are intertwined with other types of connective tissue fibers, such as collagen, which provide strength and support. The combination of these fibers allows elastic tissue to stretch and recoil efficiently, enabling organs and tissues to function properly. For example, the elasticity of lung tissue allows the lungs to expand and contract during breathing, while the elasticity of blood vessels helps maintain blood flow and pressure.

Elastic tissue can become less flexible and resilient with age or due to certain medical conditions, such as emphysema or Marfan syndrome. This can lead to a variety of health problems, including respiratory difficulties, cardiovascular disease, and skin sagging.

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.

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.

The sclera is the tough, white, fibrous outer coating of the eye in humans and other vertebrates, covering about five sixths of the eyeball's surface. It provides protection for the delicate inner structures of the eye and maintains its shape. The sclera is composed mainly of collagen and elastic fiber, making it strong and resilient. Its name comes from the Greek word "skleros," which means hard.

An intervertebral disc is a fibrocartilaginous structure found between the vertebrae of the spinal column in humans and other animals. It functions as a shock absorber, distributes mechanical stress during weight-bearing activities, and allows for varying degrees of mobility between adjacent vertebrae.

The disc is composed of two parts: the annulus fibrosus, which forms the tough, outer layer; and the nucleus pulposus, which is a gel-like substance in the center that contains proteoglycans and water. The combination of these components provides the disc with its unique ability to distribute forces and allow for movement.

The intervertebral discs are essential for the normal functioning of the spine, providing stability, flexibility, and protection to the spinal cord and nerves. However, they can also be subject to degeneration and injury, which may result in conditions such as herniated discs or degenerative disc disease.

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

The Northern blotting procedure involves several steps:

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

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

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

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

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

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

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

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

Connective Tissue Growth Factor (CTGF) is a cysteine-rich peptide growth factor that belongs to the CCN family of proteins. It plays an important role in various biological processes, including cell adhesion, migration, proliferation, and extracellular matrix production. CTGF is involved in wound healing, tissue repair, and fibrosis, as well as in the pathogenesis of several diseases such as cancer, diabetic nephropathy, and systemic sclerosis. It is expressed in response to various stimuli, including growth factors, cytokines, and mechanical stress. CTGF interacts with a variety of signaling molecules and integrins to regulate cellular responses and tissue homeostasis.

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

Protein-Lysine 6-Oxidase (PLOX) is an enzyme that belongs to the family of copper-containing oxidases. It catalyzes the oxidative deamination of specific lysine residues in proteins, resulting in the formation of lysine-6-aldehydes, ammonia, and hydrogen peroxide. This enzyme plays a crucial role in various biological processes, including the regulation of protein function, modification of extracellular matrices, and the maintenance of copper homeostasis. Mutations in the gene encoding PLOX have been associated with certain diseases, such as Menkes disease, a rare X-linked recessive disorder characterized by copper deficiency and neurological symptoms.

Epithelium is the tissue that covers the outer surface of the body, lines the internal cavities and organs, and forms various glands. It is composed of one or more layers of tightly packed cells that have a uniform shape and size, and rest on a basement membrane. Epithelial tissues are avascular, meaning they do not contain blood vessels, and are supplied with nutrients by diffusion from the underlying connective tissue.

Epithelial cells perform a variety of functions, including protection, secretion, absorption, excretion, and sensation. They can be classified based on their shape and the number of cell layers they contain. The main types of epithelium are:

1. Squamous epithelium: composed of flat, scalelike cells that fit together like tiles on a roof. It forms the lining of blood vessels, air sacs in the lungs, and the outermost layer of the skin.
2. Cuboidal epithelium: composed of cube-shaped cells with equal height and width. It is found in glands, tubules, and ducts.
3. Columnar epithelium: composed of tall, rectangular cells that are taller than they are wide. It lines the respiratory, digestive, and reproductive tracts.
4. Pseudostratified epithelium: appears stratified or layered but is actually made up of a single layer of cells that vary in height. The nuclei of these cells appear at different levels, giving the tissue a stratified appearance. It lines the respiratory and reproductive tracts.
5. Transitional epithelium: composed of several layers of cells that can stretch and change shape to accommodate changes in volume. It is found in the urinary bladder and ureters.

Epithelial tissue provides a barrier between the internal and external environments, protecting the body from physical, chemical, and biological damage. It also plays a crucial role in maintaining homeostasis by regulating the exchange of substances between the body and its environment.

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.

Hepatic stellate cells, also known as Ito cells or lipocytes, are specialized perisinusoidal cells located in the space of Disse in the liver. They play a crucial role in maintaining the normal architecture and function of the liver. In response to liver injury or disease, these cells can become activated and transform into myofibroblasts, which produce extracellular matrix components and contribute to fibrosis and scarring in the liver. This activation process is regulated by various signaling pathways and mediators, including cytokines, growth factors, and oxidative stress. Hepatic stellate cells also have the ability to store vitamin A and lipids, which they can release during activation to support hepatocyte function and regeneration.

Integrin α2β1, also known as very late antigen-2 (VLA-2) or laminin receptor, is a heterodimeric transmembrane receptor protein composed of α2 and β1 subunits. It belongs to the integrin family of adhesion molecules that play crucial roles in cell-cell and cell-extracellular matrix (ECM) interactions.

Integrin α2β1 is widely expressed on various cell types, including fibroblasts, endothelial cells, smooth muscle cells, and some hematopoietic cells. It functions as a receptor for several ECM proteins, such as collagens (type I, II, III, and V), laminin, and fibronectin. The binding of integrin α2β1 to these ECM components mediates cell adhesion, migration, proliferation, differentiation, and survival, thereby regulating various physiological and pathological processes, such as tissue repair, angiogenesis, inflammation, and tumor progression.

In addition, integrin α2β1 has been implicated in several diseases, including fibrosis, atherosclerosis, and cancer. Therefore, targeting this integrin with therapeutic strategies may provide potential benefits for treating these conditions.

Bacterial secretion systems are specialized molecular machines that allow bacteria to transport proteins and other molecules across their cell membranes. These systems play a crucial role in bacterial survival, pathogenesis, and communication with their environment. They are composed of several protein components organized into complex structures that span the bacterial cell envelope.

There are several types of bacterial secretion systems, including type I to type IX secretion systems (T1SS to T9SS). Each type has a unique structure and mechanism for transporting specific substrates across the membrane. Here are some examples:

* Type II secretion system (T2SS): This system transports folded proteins across the outer membrane of gram-negative bacteria. It is composed of 12 to 15 protein components that form a complex structure called the secretion apparatus or "secretion nanomachine." The T2SS secretes various virulence factors, such as exotoxins and hydrolases, which contribute to bacterial pathogenesis.
* Type III secretion system (T3SS): This system transports effector proteins directly into the cytosol of host cells during bacterial infection. It is composed of a hollow needle-like structure that extends from the bacterial cell surface and injects effectors into the host cell. The T3SS plays a critical role in the pathogenesis of many gram-negative bacteria, including Yersinia, Salmonella, and Shigella.
* Type IV secretion system (T4SS): This system transports DNA or proteins across the bacterial cell envelope and into target cells. It is composed of a complex structure that spans both the inner and outer membranes of gram-negative bacteria and the cytoplasmic membrane of gram-positive bacteria. The T4SS plays a role in bacterial conjugation, DNA uptake and release, and delivery of effector proteins to host cells.
* Type VI secretion system (T6SS): This system transports effector proteins into neighboring cells or the extracellular environment. It is composed of a contractile sheath-tube structure that propels effectors through a hollow inner tube and out of the bacterial cell. The T6SS plays a role in interbacterial competition, biofilm formation, and virulence.

Overall, these secretion systems play crucial roles in bacterial survival, pathogenesis, and communication with their environment. Understanding how they function and how they contribute to bacterial infection and disease is essential for developing new strategies to combat bacterial infections and improve human health.

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

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

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

Biocompatible materials are non-toxic and non-reacting substances that can be used in medical devices, tissue engineering, and drug delivery systems without causing harm or adverse reactions to living tissues or organs. These materials are designed to mimic the properties of natural tissues and are able to integrate with biological systems without being rejected by the body's immune system.

Biocompatible materials can be made from a variety of substances, including metals, ceramics, polymers, and composites. The specific properties of these materials, such as their mechanical strength, flexibility, and biodegradability, are carefully selected to meet the requirements of their intended medical application.

Examples of biocompatible materials include titanium used in dental implants and joint replacements, polyethylene used in artificial hips, and hydrogels used in contact lenses and drug delivery systems. The use of biocompatible materials has revolutionized modern medicine by enabling the development of advanced medical technologies that can improve patient outcomes and quality of life.

A growth plate, also known as an epiphyseal plate or physis, is a layer of cartilaginous tissue found near the ends of long bones in children and adolescents. This region is responsible for the longitudinal growth of bones during development. The growth plate contains actively dividing cells that differentiate into chondrocytes, which produce and deposit new matrix, leading to bone elongation. Once growth is complete, usually in late adolescence or early adulthood, the growth plates ossify (harden) and are replaced by solid bone, transforming into the epiphyseal line.

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

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

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

A keloid is a type of scar that results from an overgrowth of granulation tissue (collagen) at the site of a healed skin injury. Unlike normal scars, keloids extend beyond the borders of the original wound, invading surrounding tissues and forming smooth, hard, benign growths. They can be pink, red, or purple in color, and may become darker over time. Keloids can occur anywhere on the body, but they are most common on the earlobes, chest, shoulders, and back. They can cause itching, pain, and discomfort, and can sometimes interfere with movement. The exact cause of keloid formation is not fully understood, but it is thought to involve a combination of genetic, hormonal, and environmental factors. Treatment options for keloids include surgery, radiation therapy, corticosteroid injections, and silicone gel sheeting, although they can be difficult to eliminate completely.

Matrix metalloproteinase 3 (MMP-3), also known as stromelysin-1, is a member of the matrix metalloproteinase family. These are a group of enzymes involved in the degradation of the extracellular matrix, the network of proteins and other molecules that provides structural and biochemical support to surrounding cells. MMP-3 is secreted by various cell types, including fibroblasts, synovial cells, and chondrocytes, in response to inflammatory cytokines.

MMP-3 has the ability to degrade several extracellular matrix components, such as proteoglycans, laminin, fibronectin, and various types of collagen. It also plays a role in processing and activating other MMPs, thereby contributing to the overall breakdown of the extracellular matrix. This activity is crucial during processes like tissue remodeling, wound healing, and embryonic development; however, uncontrolled or excessive MMP-3 activation can lead to pathological conditions, including arthritis, cancer, and cardiovascular diseases.

In summary, Matrix metalloproteinase 3 (MMP-3) is a proteolytic enzyme involved in the degradation of the extracellular matrix and the activation of other MMPs. Its dysregulation has been implicated in several diseases.

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

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

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

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.

Connective tissue cells are a type of cell that are responsible for the production and maintenance of the extracellular matrix (ECM), which provides structural support and separates different tissues in the body. There are several types of connective tissue cells, including:

1. Fibroblasts: These are the most common type of connective tissue cell. They produce and maintain the ECM by synthesizing and secreting collagen, elastin, and other proteins that give the matrix its strength and elasticity.
2. Chondrocytes: These cells are found in cartilage and are responsible for producing and maintaining the cartilaginous matrix, which is composed of collagen and proteoglycans.
3. Osteoblasts: These cells are responsible for the formation and mineralization of bone tissue. They produce and secrete type I collagen and other proteins that form the organic matrix of bone, and they also regulate the deposition of calcium salts that mineralize the matrix.
4. Adipocytes: These are fat cells that store energy in the form of lipids. They are found in adipose tissue, which is a type of connective tissue that provides insulation and cushioning to the body.
5. Macrophages: These are large, mobile phagocytic cells that play an important role in the immune system. They are derived from monocytes and are found in many types of connective tissue, where they help to remove foreign particles, debris, and microorganisms.
6. Mast cells: These are connective tissue cells that contain granules filled with histamine, heparin, and other substances that are involved in inflammation and allergic reactions. They play a role in the immune response by releasing these granules when activated by antigens or other stimuli.

Connective tissue cells are essential for maintaining the structure and function of the body's tissues and organs, and they play an important role in wound healing, tissue repair, and the immune response.

'DBA' is an abbreviation for 'Database of Genotypes and Phenotypes,' but in the context of "Inbred DBA mice," it refers to a specific strain of laboratory mice that have been inbred for many generations. The DBA strain is one of the oldest inbred strains, and it was established in 1909 by C.C. Little at the Bussey Institute of Harvard University.

The "Inbred DBA" mice are genetically identical mice that have been produced by brother-sister matings for more than 20 generations. This extensive inbreeding results in a homozygous population, where all members of the strain have the same genetic makeup. The DBA strain is further divided into several sub-strains, including DBA/1, DBA/2, and DBA/J, among others.

DBA mice are known for their black coat color, which can fade to gray with age, and they exhibit a range of phenotypic traits that make them useful for research purposes. For example, DBA mice have a high incidence of retinal degeneration, making them a valuable model for studying eye diseases. They also show differences in behavior, immune response, and susceptibility to various diseases compared to other inbred strains.

In summary, "Inbred DBA" mice are a specific strain of laboratory mice that have been inbred for many generations, resulting in a genetically identical population with distinct phenotypic traits. They are widely used in biomedical research to study various diseases and biological processes.

Physiologic calcification is the normal deposit of calcium salts in body tissues and organs. It is a natural process that occurs as part of the growth and development of the human body, as well as during the repair and remodeling of tissues.

Calcium is an essential mineral that plays a critical role in many bodily functions, including bone formation, muscle contraction, nerve impulse transmission, and blood clotting. In order to maintain proper levels of calcium in the body, excess calcium that is not needed for these functions may be deposited in various tissues as a normal part of the aging process.

Physiologic calcification typically occurs in areas such as the walls of blood vessels, the lungs, and the heart valves. While these calcifications are generally harmless, they can sometimes lead to complications, particularly if they occur in large amounts or in sensitive areas. For example, calcification of the coronary arteries can increase the risk of heart disease, while calcification of the lung tissue can cause respiratory symptoms.

It is important to note that pathologic calcification, on the other hand, refers to the abnormal deposit of calcium salts in tissues and organs, which can be caused by various medical conditions such as chronic kidney disease, hyperparathyroidism, and certain infections. Pathologic calcification is not a normal process and can lead to serious health complications if left untreated.

Immunoblotting, also known as western blotting, is a laboratory technique used in molecular biology and immunogenetics to detect and quantify specific proteins in a complex mixture. This technique combines the electrophoretic separation of proteins by gel electrophoresis with their detection using antibodies that recognize specific epitopes (protein fragments) on the target protein.

The process involves several steps: first, the protein sample is separated based on size through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Next, the separated proteins are transferred onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric field. The membrane is then blocked with a blocking agent to prevent non-specific binding of antibodies.

After blocking, the membrane is incubated with a primary antibody that specifically recognizes the target protein. Following this, the membrane is washed to remove unbound primary antibodies and then incubated with a secondary antibody conjugated to an enzyme such as horseradish peroxidase (HRP) or alkaline phosphatase (AP). The enzyme catalyzes a colorimetric or chemiluminescent reaction that allows for the detection of the target protein.

Immunoblotting is widely used in research and clinical settings to study protein expression, post-translational modifications, protein-protein interactions, and disease biomarkers. It provides high specificity and sensitivity, making it a valuable tool for identifying and quantifying proteins in various biological samples.

Osteoarthritis (OA) is a type of joint disease that is characterized by the breakdown and eventual loss of cartilage - the tissue that cushions the ends of bones where they meet in the joints. This breakdown can cause the bones to rub against each other, causing pain, stiffness, and loss of mobility. OA can occur in any joint, but it most commonly affects the hands, knees, hips, and spine. It is often associated with aging and can be caused or worsened by obesity, injury, or overuse.

The medical definition of osteoarthritis is: "a degenerative, non-inflammatory joint disease characterized by the loss of articular cartilage, bone remodeling, and the formation of osteophytes (bone spurs). It is often associated with pain, stiffness, and decreased range of motion in the affected joint."

Platelet aggregation is the clumping together of platelets (thrombocytes) in the blood, which is an essential step in the process of hemostasis (the stopping of bleeding) after injury to a blood vessel. When the inner lining of a blood vessel is damaged, exposure of subendothelial collagen and tissue factor triggers platelet activation. Activated platelets change shape, become sticky, and release the contents of their granules, which include ADP (adenosine diphosphate).

ADP then acts as a chemical mediator to attract and bind additional platelets to the site of injury, leading to platelet aggregation. This forms a plug that seals the damaged vessel and prevents further blood loss. Platelet aggregation is also a crucial component in the formation of blood clots (thrombosis) within blood vessels, which can have pathological consequences such as heart attacks and strokes if they obstruct blood flow to vital organs.

Hyaluronic acid is a glycosaminoglycan, a type of complex carbohydrate, that is naturally found in the human body. It is most abundant in the extracellular matrix of soft connective tissues, including the skin, eyes, and joints. Hyaluronic acid is known for its remarkable capacity to retain water, which helps maintain tissue hydration, lubrication, and elasticity. Its functions include providing structural support, promoting wound healing, and regulating cell growth and differentiation. In the medical field, hyaluronic acid is often used in various forms as a therapeutic agent for conditions like osteoarthritis, dry eye syndrome, and skin rejuvenation.

'Agrobacterium tumefaciens' is a gram-negative, soil-dwelling bacterium that is known for its ability to cause plant tumors or crown galls. It does this through the transfer and integration of a segment of DNA called the Ti (Tumor-inducing) plasmid into the plant's genome. This transferred DNA includes genes that encode enzymes for the production of opines, which serve as a nutrient source for the bacterium, and genes that cause unregulated plant cell growth leading to tumor formation.

This unique ability of 'Agrobacterium tumefaciens' to transfer and integrate foreign DNA into plants has been exploited in genetic engineering to create transgenic plants with desired traits. The Ti plasmid is often used as a vector to introduce new genes into the plant genome, making it an essential tool in plant biotechnology.

Amino acids are organic compounds that serve as the building blocks of proteins. They consist of a central carbon atom, also known as the alpha carbon, which is bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (H), and a variable side chain (R group). The R group can be composed of various combinations of atoms such as hydrogen, oxygen, sulfur, nitrogen, and carbon, which determine the unique properties of each amino acid.

There are 20 standard amino acids that are encoded by the genetic code and incorporated into proteins during translation. These include:

1. Alanine (Ala)
2. Arginine (Arg)
3. Asparagine (Asn)
4. Aspartic acid (Asp)
5. Cysteine (Cys)
6. Glutamine (Gln)
7. Glutamic acid (Glu)
8. Glycine (Gly)
9. Histidine (His)
10. Isoleucine (Ile)
11. Leucine (Leu)
12. Lysine (Lys)
13. Methionine (Met)
14. Phenylalanine (Phe)
15. Proline (Pro)
16. Serine (Ser)
17. Threonine (Thr)
18. Tryptophan (Trp)
19. Tyrosine (Tyr)
20. Valine (Val)

Additionally, there are several non-standard or modified amino acids that can be incorporated into proteins through post-translational modifications, such as hydroxylation, methylation, and phosphorylation. These modifications expand the functional diversity of proteins and play crucial roles in various cellular processes.

Amino acids are essential for numerous biological functions, including protein synthesis, enzyme catalysis, neurotransmitter production, energy metabolism, and immune response regulation. Some amino acids can be synthesized by the human body (non-essential), while others must be obtained through dietary sources (essential).

Aminopropionitrile is a chemical compound with the formula NPN(H2)CH2CH2CN. It is an irritant that can cause damage to the eyes, skin, and respiratory system. It is used in the manufacture of certain plastics and resins, and has also been studied for its potential effects on the human body. Some research suggests that aminopropionitrile may interfere with the normal functioning of collagen, a protein that helps to provide structure and support to tissues and organs in the body. This has led to interest in the use of aminopropionitrile as a potential treatment for certain conditions related to collagen, such as scleroderma. However, more research is needed to determine the safety and effectiveness of this use.

Oligopeptides are defined in medicine and biochemistry as short chains of amino acids, typically containing fewer than 20 amino acid residues. These small peptides are important components in various biological processes, such as serving as signaling molecules, enzyme inhibitors, or structural elements in some proteins. They can be found naturally in foods and may also be synthesized for use in medical research and therapeutic applications.

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

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

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

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

Osteoblasts are specialized bone-forming cells that are derived from mesenchymal stem cells. They play a crucial role in the process of bone formation and remodeling. Osteoblasts synthesize, secrete, and mineralize the organic matrix of bones, which is mainly composed of type I collagen.

These cells have receptors for various hormones and growth factors that regulate their activity, such as parathyroid hormone, vitamin D, and transforming growth factor-beta. When osteoblasts are not actively producing bone matrix, they can become trapped within the matrix they produce, where they differentiate into osteocytes, which are mature bone cells that play a role in maintaining bone structure and responding to mechanical stress.

Abnormalities in osteoblast function can lead to various bone diseases, such as osteoporosis, osteogenesis imperfecta, and Paget's disease of bone.

Reticulin is a type of protein fiber that forms part of the extracellular matrix in various connective tissues in the body. It is composed of collagenous and non-collagenous proteins, and it has a reticular or network-like structure when viewed under a microscope. In histology (the study of the microscopic structure of tissues), reticulin fibers are often stained to help identify certain types of cells or structures.

In particular, reticulin fibers are often found in close association with certain types of cells, such as hematopoietic stem cells and neurons. They provide structural support and help regulate the function of these cells. In addition, reticulin fibers play a role in the immune response, wound healing, and tissue repair.

Abnormal accumulations of reticulin fibers can be seen in various disease states, such as fibrosis (excessive scarring) and certain types of cancer. For example, increased reticulin fibers are often found in the liver in patients with cirrhosis, a condition characterized by extensive scarring and damage to the liver. Similarly, abnormal reticulin fiber deposition is seen in some forms of lymphoma, a type of cancer that affects the lymphatic system.

Tenascin is a large extracellular matrix protein that is involved in various biological processes, including cell adhesion, migration, and differentiation. It is found in high concentrations during embryonic development, tissue repair, and inflammation. Tenascin has a modular structure, consisting of multiple domains that can interact with various cell surface receptors and other extracellular matrix components. Its expression is regulated by a variety of growth factors, cytokines, and mechanical signals, making it an important player in the dynamic regulation of tissue architecture and function. In pathological conditions, abnormal tenascin expression has been implicated in various diseases, such as fibrosis, cancer, and autoimmune disorders.

Von Willebrand factor (vWF) is a large multimeric glycoprotein that plays a crucial role in hemostasis, the process which leads to the cessation of bleeding and the formation of a blood clot. It was named after Erik Adolf von Willebrand, a Finnish physician who first described the disorder associated with its deficiency, known as von Willebrand disease (vWD).

The primary functions of vWF include:

1. Platelet adhesion and aggregation: vWF mediates the initial attachment of platelets to damaged blood vessel walls by binding to exposed collagen fibers and then interacting with glycoprotein Ib (GPIb) receptors on the surface of platelets, facilitating platelet adhesion. Subsequently, vWF also promotes platelet-platelet interactions (aggregation) through its interaction with platelet glycoprotein IIb/IIIa (GPIIb/IIIa) receptors under high shear stress conditions found in areas of turbulent blood flow, such as arterioles and the capillary bed.

2. Transport and stabilization of coagulation factor VIII: vWF serves as a carrier protein for coagulation factor VIII (FVIII), protecting it from proteolytic degradation and maintaining its stability in circulation. This interaction between vWF and FVIII is essential for the proper functioning of the coagulation cascade, particularly in the context of vWD, where impaired FVIII function can lead to bleeding disorders.

3. Wound healing: vWF contributes to wound healing by promoting platelet adhesion and aggregation at the site of injury, which facilitates the formation of a provisional fibrin-based clot that serves as a scaffold for tissue repair and regeneration.

In summary, von Willebrand factor is a vital hemostatic protein involved in platelet adhesion, aggregation, coagulation factor VIII stabilization, and wound healing. Deficiencies or dysfunctions in vWF can lead to bleeding disorders such as von Willebrand disease.

Mucolipidoses are a group of inherited metabolic disorders characterized by the accumulation of complex carbohydrates (muco-) and fatty substances (lipids) in various tissues and cells (-oses). This is due to deficiency in enzymes that help break down these substances within lysosomes, which are organelles responsible for recycling and breaking down waste materials inside the cell.

There are four main types of mucolipidoses (I, II, III, and IV), each resulting from specific genetic mutations affecting different enzymes or proteins involved in the lysosomal degradation pathway. The symptoms, severity, and age of onset can vary widely among these types, ranging from mild to severe and including developmental delays, bone abnormalities, vision and hearing loss, heart problems, and coarse facial features.

Mucolipidoses are typically inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to develop the condition. However, mucolipidosis II is caused by X-linked inheritance, where a single copy of the mutated gene on the X chromosome is enough to cause the disorder.

Early diagnosis and management of mucolipidoses can help improve quality of life and slow disease progression. Treatment options include physical therapy, occupational therapy, speech therapy, medications for symptom management, and in some cases, enzyme replacement therapy or bone marrow transplantation.

Arthritis is a medical condition characterized by inflammation in one or more joints, leading to symptoms such as pain, stiffness, swelling, and reduced range of motion. There are many different types of arthritis, including osteoarthritis, rheumatoid arthritis, psoriatic arthritis, gout, and lupus, among others.

Osteoarthritis is the most common form of arthritis and is caused by wear and tear on the joints over time. Rheumatoid arthritis, on the other hand, is an autoimmune disorder in which the body's immune system mistakenly attacks the joint lining, causing inflammation and damage.

Arthritis can affect people of all ages, including children, although it is more common in older adults. Treatment for arthritis may include medications to manage pain and reduce inflammation, physical therapy, exercise, and in some cases, surgery.

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

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.

Collagen IV is the more common usage, as opposed to the older terminology of "type-IV collagen".[citation needed] Collagen IV ... Collagen IV (ColIV or Col4) is a type of collagen found primarily in the basal lamina. The collagen IV C4 domain at the C- ... May 2001). "Urinary type IV collagen excretion reflects renal morphological alterations and type IV collagen expression in ... show that the collagen hybridizing peptide probes can be used across species and collagen types (including type IV collagen), ...
"Duplication of type IV collagen COOH-terminal repeats and species-specific expression of alpha 1(IV) and alpha 2(IV) collagen ... IV) chains of human basement membrane collagen type IV are arranged head-to-head and separated by a bidirectional promoter of ... "The complete primary structure of the alpha 2 chain of human type IV collagen and comparison with the alpha 1(IV) chain". J. ... type IV). The amino acid sequence of the alpha 2(IV) chain and its comparison with the alpha 1(IV) chain reveals deletions in ...
... of type IV collagen in synovial capillaries by immunohistochemistry using a monoclonal antibody against human type IV collagen ... Collagen Type-IV collagen Alport syndrome GRCh38: Ensembl release 89: ENSG00000188153 - Ensembl, May 2017 GRCm38: Ensembl ... type IV, alpha 5 (Alport syndrome)". Lemmink HH, Schröder CH, Monnens LA, Smeets HJ (1997). "The clinical spectrum of type IV ... Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another ...
... or collagen IV NC1 domain) is a duplicated domain present at the C-terminus of type IV collagens. Each type IV collagen ... Structural basis for type IV collagen assembly in basement membranes". J. Biol. Chem. 277 (34): 31142-53. doi:10.1074/jbc. ... In molecular biology, the type IV collagen C4 domain ( ... The collagen IV C4 domain is composed of two similarly folded ... domain of human placenta collagen IV shows stabilization via a novel type of covalent Met-Lys cross-link". Proc. Natl. Acad. ...
It is ubiquitously expressed in many tissues and cell types. COL4A1 is a subunit of the type IV collagen and plays a role in ... IV) chains of human basement membrane collagen type IV are arranged head-to-head and separated by a bidirectional promoter of ... IV), alpha 5(IV), and alpha 6(IV) collagen chains in normal human adult and fetal tissues and in kidneys from X-linked Alport ... Type IV collagen is the major structural component of basement membranes, which contains two or three COL4A1 proteins. Thus, ...
... this gene is organized in a head-to-head conformation with another type IV collagen gene, alpha 5 type IV collagen, so that the ... of type IV collagen in synovial capillaries by immunohistochemistry using a monoclonal antibody against human type IV collagen ... IV). Isolation of the cDNAs for alpha 6(IV) and comparison with five other type IV collagen chains". J. Biol. Chem. 269 (18): ... collagen chain and comparison with other type IV collagen genes". J. Biol. Chem. 270 (45): 26863-7. doi:10.1074/jbc.270.45. ...
IV) chains of type IV collagen to chromosome 2 bands q35-q37". Genomics. 13 (3): 809-13. doi:10.1016/0888-7543(92)90157-N. PMID ... "Entrez Gene: COL4A4 collagen, type IV, alpha 4". Hinek A (1995). "Nature and the multiple functions of the 67-kD elastin-/ ... 2003). "Type-IV collagen related diseases". J. Nephrol. 16 (2): 314-6. PMID 12768082. Torra R, Tazón-Vega B, Ars E, Ballarín J ... Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another ...
Collagen alpha-3(IV) chain is a protein that in humans is encoded by the COL4A3 gene. Type IV collagen, the major structural ... 2003). "Type-IV collagen related diseases". J. Nephrol. 16 (2): 314-6. PMID 12768082. Torra R, Tazón-Vega B, Ars E, Ballarín J ... Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another ... "Entrez Gene: COL4A3 collagen, type IV, alpha 3 (Goodpasture antigen)". Hinek A (1995). "Nature and the multiple functions of ...
"Type VI collagen anchors endothelial basement membranes by interacting with type IV collagen". J. Biol. Chem. 272 (42): 26522-9 ... "Entrez Gene: COL6A1 collagen, type VI, alpha 1". Bertini E, Pepe G (2002). "Collagen type VI and related disorders: Bethlem ... The protein encoded by this gene is the alpha 1 subunit of type VI collagen (alpha1(VI) chain). Mutations in the genes that ... 1996). "Type VI collagen mutations in Bethlem myopathy, an autosomal dominant myopathy with contractures". Nat. Genet. 14 (1): ...
"Type VI collagen anchors endothelial basement membranes by interacting with type IV collagen". J. Biol. Chem. 272 (42): 26522-9 ... "Entrez Gene: COL6A2 collagen, type VI, alpha 2". "COLLAGEN, TYPE VI, ALPHA-2; COL6A2". www.omim.org. Retrieved 2023-10-13. ... This gene encodes one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective ... 1996). "Type VI collagen mutations in Bethlem myopathy, an autosomal dominant myopathy with contractures". Nat. Genet. 14 (1): ...
Type VI collagen anchors endothelial basement membranes by interacting with type IV collagen. J. Biol. Chem. 272, 26522-26529. ... Collagen VI (ColVI) is a type of collagen primarily associated with the extracellular matrix of skeletal muscle. ColVI ... Lampe AK, Flanigan KM, Bushby KM, Hicks D (August 9, 2012). "Collagen VI-Related Dystrophies". Collagen Type VI-Related ... ColVI maintains a mechanical function in the cell, which is typical of most types of Collagen, by providing stability and ...
It binds fibril-forming collagens and primarily type IV collagen, but also collagen of types I, VI, VIII. It is expressed ... It preferentially binds collagens IV, VI and type XIII collagen, but also fibril-forming collagens. Specific binding sites in ... A ligand of Lair-1 receptor is type XVII transmembrane collagen, it binds type I and III collagen as well. Collagen binding ... Binds fibril-forming collagens, collagen of types I, II, III and X. A specific binding site in collagen II has been identified ...
... including laminin-5 and collagen IV, contribute greatly to the overall stability of the basement membrane. Type VII collagen is ... This gene encodes the alpha chain of type VII collagen. The type VII collagen fibril, composed of three identical alpha ... "Cleavage of type VII collagen by interstitial collagenase and type IV collagenase (gelatinase) derived from human skin". The ... in the collagen type VII alpha 1 chain (COL7A1) gene. Collagen, type VII, alpha 1 forms a complex network with several other ...
... of cysteine-rich collagens from bovine placental tissues and uterus and their relationship to types IV and V collagens". Biosci ... related to type XI collagen and it is possible that the collagen chains of types V and XI constitute a single collagen type ... Fibrillar collagen molecules are trimers that can be composed of one or more types of alpha chains. Type V collagen is found in ... type I collagen and appears to regulate the assembly of heterotypic fibers composed of both type I and type V collagen. This ...
... and Type IV Collagen". New England Journal of Medicine. 348 (25): 2543-2556. doi:10.1056/NEJMra022296. PMID 12815141. Liu, ... "Isolation and characterization of type IV procollagen, laminin, and heparan sulfate proteoglycan from the EHS sarcoma". ... Glomeruli and their basement membrane in the normal human kidney and in congenital nephrotic syndrome of the Finnish type. ... "Identification of Mutations in the COL4A5 Collagen Gene in Alport Syndrome". Science. 248 (4960): 1224-1227. Bibcode:1990Sci... ...
Such as type 4 collagen Shaw, Andrey S.; Filbert, Erin L. (January 2009). "Scaffold proteins and immune-cell signalling". ... Scaffold proteins act in at least four ways: tethering signaling components, localizing these components to specific areas of ... "Human Homologue of the Drosophila Discs Large Tumor Suppressor Binds to p56 lck Tyrosine Kinase and Shaker Type Kv1.3 Potassium ... 289 (4): 2353-2360. doi:10.1074/jbc.M113.497941. PMC 3900978. PMID 24302730. Clapéron, A.; Therrien, M. (May 2007). "KSR and ...
It contains fibronectin, type IV collagen, perlecan, and laminin. Intraglomerular mesangial cells phagocytize glomerular basal ... Mesangium Extraglomerular mesangial cell List of human cell types derived from the germ layers Lote, Christopher J. Principles ...
The collagenases digest Types I, II, III, VII and X collagen. The gelatinases exist in two forms; one digesting Type-IV ... The trophoblast have binding fiber connections, laminin, collagen type IV, and integrins that assist in this adhesion process. ... The first four stages are similar across the species with the process of invasion being variable. These three stages of ... The morula enters the uterus after three or four days, and as it does a cavity called the blastocoel is formed in the morula to ...
The amniotic membrane, the inner part of the placenta, has a thick basement membrane of collagen type IV and laminin and ... Basement membrane: containing type IV collagen, laminin, fibronectin and integrins. Ideally, the basement membrane must contain ... Collagen (mainly collagen type I) is often used as a scaffold because it is biocompatible, non-immunogenic and available. ... Collagen-elastine membrane, collagen-glycosaminoglycane (C-GAG) matrix, cross-linked collagen matrix Integra and Terudermis are ...
This is a receptor for collagen type I and IV. It consists of two subunits (α2 and β1). The α2 subunit includes a domain ... The β1 subunit has four cysteine-rich regions and a structure similar to other β-integrins. The interaction with collagen leads ... Glycoprotein VI is one of the immunoglobulin superfamily type I transmembrane glycoproteins. It is an important collagen ... integrin upon release from keratinocytes migrating on type I collagen". J. Biol. Chem. (United States) 276 (31): 29368-74. DOI: ...
Collagen type IV stain will have a strong continuous staining around nests. Nuclei are small, regular, round and basal in the ... The two main types of hyperplastic polyps are microvesicular mucin-rich type and goblet cell-rich type. A mucin-poor type with ... A hyperplastic polyp is a type of colorectal polyp. Most hyperplastic polyps are found in the distal colon and rectum. They ... However, the mucin poor type is no longer considered a distinct subtype. The luminal portion has a serrated ("saw tooth") ...
Type IV collagen '112' type is found in both vertebrates and invertebrates and is the major isoform in most human basement ... Since type IV collagen is found in the ears, eyes, and kidneys, this explains why Alport syndrome affects different seemingly ... When mutations prevent the formation of 345 type IV collagen network in the glomerulus, the 112 network, which is formed in ... Transplantation can rarely be associated with the formation of antibodies to type IV collagen in the donor kidney resulting in ...
Donovan FM, Vaughan PJ, Cunningham DD (1994). "Regulation of protease nexin-1 target protease specificity by collagen type IV ... "Protease nexin 1 is a potent urinary plasminogen activator inhibitor in the presence of collagen type IV". J. Biol. Chem. 277 ( ... "Entrez Gene: SERPINE2 serpin peptidase inhibitor, clade E (nexin, plasminogen activator inhibitor type 1), member 2". Naldini L ... doi:10.1016/S0021-9258(18)88883-4. PMID 3997857. Magnaldo T, Bernerd F, Darmon M (1995). "Galectin-7, a human 14-kDa S-lectin, ...
... defects in type IV collagen have been reported in some families. Some individuals with TBMD are thought to be carriers for ... defects in the gene encoding the a4 chain of type IV collagen have been reported in some families.[citation needed] Overall, ... GeneReviews/NCBI/NIH/UW entry on Collagen IV-Related Nephropathies (Alport Syndrome and Thin Basement Membrane Nephropathy) ( ... 64 (4): 1169-78. doi:10.1046/j.1523-1755.2003.00234.x. PMID 12969134. Hou P, Chen Y, Ding J, Li G, Zhang H (2007). "A novel ...
Collagen type IV alpha-3-binding protein, also known as ceramide transfer protein (CERT) or StAR-related lipid transfer protein ... "Entrez Gene: COL4A3BP collagen, type IV, alpha 3 (Goodpasture antigen) binding protein". Merrill AH (Jul 2002). "De novo ... that specifically phosphorylates the N-terminal region of the non-collagenous domain of the alpha 3 chain of type IV collagen, ... PH domain of wild-type CERT has been found to recognize specifically PI4P and therefore CERT targets the Golgi apparatus or the ...
Cleaves type IV collagen at Ala73-Gln in alpha1(IV) and at Gly7-Leu in alpha2(IV) This endopeptidase is present in the venom of ... "Identification of the cleavage sites by a hemorrhagic metalloproteinase in type IV collagen". Matrix. 10 (2): 91-7. doi:10.1016 ...
... with type IV collagen". The Journal of Biological Chemistry. 265 (28): 17281-4. doi:10.1016/S0021-9258(17)44900-3. PMID 2211625 ... 16 (4): 1013-9. PMID 11642720. Kloen P, Di Paola M, Borens O, Richmond J, Perino G, Helfet DL, Goumans MJ (September 2003). " ... 20 (1-4): 313-9. doi:10.3109/03008208909023902. PMID 2612162. Wozney JM, Rosen V, Celeste AJ, Mitsock LM, Whitters MJ, Kriz RW ... Jin Y, Lu HB, Liong E, Lau TY, Tipoe GL (October 2001). "Transcriptional mRNA of BMP-2, 3, 4 and 5 in trigeminal nerve, benign ...
Interaction of osteogenin, a heparin binding bone morphogenetic protein, with type IV collagen. J Biol Chem 1990; 265:17281-4. ... Transforming growth factor beta type 1 binds to collagen IV of basement membrane matrix: implications for development. Dev Biol ... potentiation and binding to type IV collagen. J Cell Biol 1992; 119:1721-8. Ripamonti U, Ma S, Cunningham NS, Yeates L, Reddi ... Transitions in collagen types during matrix-induced cartilage, bone, and bone marrow formation. Proc Natl Acad Sci U S A 1977; ...
The lamina densa is the central layer consisting of type IV collagen and laminin. This layer acts as a selective macromolecular ... The glomerulus is a small tuft of capillaries containing two cell types. Endothelial cells, which have large fenestrae, are not ...
This strength comes from the type IV collagen in between the endothelial and epithelial cells. Damage can occur to this barrier ... It is formed by the type I pneumocytes of the alveolar wall, the endothelial cells of the capillaries and the basement membrane ...
Collagen IV is the more common usage, as opposed to the older terminology of "type-IV collagen".[citation needed] Collagen IV ... Collagen IV (ColIV or Col4) is a type of collagen found primarily in the basal lamina. The collagen IV C4 domain at the C- ... May 2001). "Urinary type IV collagen excretion reflects renal morphological alterations and type IV collagen expression in ... show that the collagen hybridizing peptide probes can be used across species and collagen types (including type IV collagen), ...
Blue cells = expressed in wild-type.. Gray triangles = other expression annotations only. (e.g. absence of expression or data ...
Blue cells = expressed in wild-type.. Gray triangles = other expression annotations only. (e.g. absence of expression or data ... 52 phenotypes from 4 alleles in 7 genetic backgrounds 22 phenotypes from multigenic genotypes 3 images 96 phenotype references ... IPR001442 Collagen IV, non-collagenous. IPR036954 Collagen IV, non-collagenous domain superfamily ...
Many studies have evaluated the relationship between AA and collagen expression in short- and long-term effects on cells after ... is essential for collagen biosynthesis as a cofactor for prolyl and lysyl hydroxylase and as a stimulus for collagen gene ... Ascorbic acid enhances the expression of type 1 and type 4 collagen and SVCT2 in cultured human skin fibroblasts Biochem ... Thus, these results indicate that human skin fibroblasts exposed to AA over time had rising levels of type 1/type 4 collagens ...
Types IV and V Collagens in Cryptogenic Fibrosing Alveolitis J.M.E. Kirk; J.M.E. Kirk ... J.M.E. Kirk, J.R.B. Hasting, G.J. Laurent; Types IV and V Collagens in Cryptogenic Fibrosing Alveolitis. Clin Sci (Lond) 1 ...
Composition and structural organization of type IV collagen in the GBM of healthy adult dogs is different from that described ... Results-Immunolabeling of the α6(IV) chain was not observed in GBM of 6 dogs ≤ 30 months old but was observed in GBM of the ... Expression of the α6(IV) chain was not observed in GBM of the human subjects, regardless of the age of the subject. Conclusions ... Procedure-Sections were immunolabeled with a monospecific antibody that cross-reacts with human and canine α6(IV) chains and ...
In addition to its role in the formation of epithelium and vasculature, type IV collagen appears to be key for alveolar ... Our study showed that type IV collagen and, therefore the basement membrane, play fundamental roles in coordinating alveolar ... Lastly, we revealed that addition of type IV collagen protein induced myofibroblast proliferation and migration in monolayer ... the specific role of type IV collagen in regulating alveologenesis remains unknown. We have performed a microarray expression ...
To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have ... T F Linsenmayer, E Gibney, J M Fitch, J Gross, R Mayne; Thermal stability of the helical structure of type IV collagen within ... To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have ... We conclude that the stability of the helical structure of type IV collagen within a basement membrane is considerably greater ...
"Collagen Type IV" by people in this website by year, and whether "Collagen Type IV" was a major or minor topic of these ... A non-fibrillar collagen found in the structure of BASEMENT MEMBRANE. Collagen type IV molecules assemble to form a sheet-like ... Type IV (Basement Membrane) Collagen. *Type IV Collagen. *Collagen, Type IV. Collagen Type IV, alpha1 Subunit*Collagen Type IV ... "Collagen Type IV" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ...
Get Rocklands Anti-Collagen Type IV (RABBIT) Antibody - 600-401-106-0.1 for Dot Blot, IHC, IF, WB, Multiplex. Reacts with ... Collagen Type IV Antibody Fluorescein Conjugated Collagen Type IV Antibody Biotin Conjugated Collagen Type IV Antibody ... Specifications for Collagen Type IV Antibody Product Details. Description:. Anti-Collagen Type IV (RABBIT) Antibody - 600-401- ... Collagen Type IV from human and bovine placenta Purity/Specificity:. Anti-Collagen Type IV has been prepared by immunoaffinity ...
Tagschondrolysis, friday pop quiz, collagen, collagen type, Type 2 collagen, relapsing polychondritis, Type 2 cartilage. Post ... Collagen Type - Friday Pop Quiz 11/4/2022. Antibodies mediated towards what collagen type leads to the condition depicted in ...
By J M. Fitch, E Gibney, R D. Sanderson, et al., Published on 01/01/82
Check reviews and buy Collagen Recovery Eye Mask - 4 types - 16 Pieces in individual cases today. ... Buy Collagen Recovery Eye Mask - 4 types - 16 Pieces in individual cases at the lowest price in United States. ... Collagen eye pad kit contains four types of under-eye collagen patches for most skin conditions: ... Collagen Recovery Eye Mask - 4 types - 16 Pieces in individual cases. (6) ...
SVEVs isolated from lyophilized venoms collected from four different species of snakes (Agkistrodon contortrix contortrix, ... C-type lectin, CRISP and Disintegrin. Biochemical assays indicated that SVEVs are functionally active, showing high ... Kuhn, K. Basement membrane (type IV) collagen. Matrix biology: journal of the International Society for Matrix Biology 14, 439- ... Since type IV collagen plays a key role in the mechanical stability of BM and hence of the capillary vessel structure77,78, ...
We suggest that an ancestral NC1 may have been incorporated into type IV collagen as an evolutionarily mobile domain carrying ... The inferred tree verified that type IV collagen sequences fall into two groups, alpha1-like and alpha2-like, and suggested ... sequences and may play a role in the stoichiometric chain selection upon type IV collagen assembly. Neural network secondary ... Type IV collagen alpha1-alpha6 chains have important roles in the assembly of basement membranes and are implicated in the ...
Osteogenesis imperfecta type IV. Detection of a point mutation in one α1(I) collagen allele (COL1A1) by RNA/RNA hybrid analysis ... Osteogenesis imperfecta type IV. Detection of a point mutation in one α1(I) collagen allele (COL1A1) by RNA/RNA hybrid analysis ... Osteogenesis imperfecta type IV. Detection of a point mutation in one α1(I) collagen allele (COL1A1) by RNA/RNA hybrid analysis ... T1 - Osteogenesis imperfecta type IV. Detection of a point mutation in one α1(I) collagen allele (COL1A1) by RNA/RNA hybrid ...
Dynamics of type IV collagen 7S fragment on eradication of HCV with direct antiviral agents: Prognostic and metabolomic impacts ... Dynamics of type IV collagen 7S fragment on eradication of HCV with direct antiviral agents: Prognostic and metabolomic impacts ... Dynamics of type IV collagen 7S fragment on eradication of HCV with direct antiviral agents: Prognostic and metabolomic impacts ... Dynamics of type IV collagen 7S fragment on eradication of HCV with direct antiviral agents : Prognostic and metabolomic ...
The COL4A1 gene provides instructions for making one component of type IV collagen, which is a flexible protein important in ... IV) chain called alpha2 to make a complete type IV collagen alpha1-1-2 molecule. Type IV collagen molecules attach to each ... Specifically, this gene makes the alpha1(IV) chain of type IV collagen. This chain combines with another alpha1 chain and a ... IV) chain of type IV collagen. Specifically, the mutations replace the amino acid glycine with a different amino acid at one of ...
Circulating type IV collagen (COLIV) is a new potential CLM marker. Here, COLIV and CEA were measured in patients with ... Improved tumour marker sensitivity in detecting colorectal liver metastases by combined type IV collagen and CEA measurement.. ... COLIV levels were also related to the type of CLM. The prognostic value of these markers and the type of CLM on survival was ... COLIV and CEA levels were analysed, and the type of CLM was classified using paraffinated tissue. Results were analysed by ...
Endothelial cell-specific collagen type IV-α3 expression does not rescue Alport syndrome in Col4a3-/- mice. Am J Physiol Renal ... In WT GBM, a linear collagen IV localization was observed for collagen IV and collagen IV α3, α4, and α5 proteins, indicating ... collagen IV alignment was split, and irregular network formation (white arrows) was observed for collagen IV, collagen IV α3, ... We observed a decrease not only in collagen IV, but also in collagen IV interactors (i.e., collagen XVIII α1 and nidogen 1). ...
Collagen is a protein in the body that helps make bones strong. ... often caused by a problem with type IV collagen. The symptoms ... What Is Collagen?. Collagen (KOL-uh-jin) is a protein in the body. Different types of collagen are in many body parts, ... Most of it is type I collagen, found in bones and tendons. But we also have:. *type II collagen, found in cartilage. (the ... What Problems Can Happen With Collagen?. Depending on which type of collagen is affected, problems can include:. *osteogenesis ...
The target antigen is the alpha-3 chain of type IV collagen. ... Type IV collagen is a polymeric structure. The basic monomer of ... The Goodpasture antigen is the carboxyl terminal, noncollagenous domain of the alpha-3 chain of type IV collagen (alpha-3[IV] ... The alpha-3 chain of type IV collagen is expressed in the basement membranes of the glomerulus, alveoli, choroid plexus, eye, ... type IV collagen) protein lacking the NC1 domain did not develop anti-GBM glomerulonephritis in the graft. ...
Expression of the α6 chain of type IV collagen in glomerular basement membranes of healthy adult dogs ... Expression of the α6 chain of type IV collagen in glomerular basement membranes of healthy adult dogs ... 4. International Organization for Standardization. ISO/IEC 17025:2017. General requirements for the competence of testing and ... 4. International Organization for Standardization. ISO/IEC 17025:2017. General requirements for the competence of testing and ...
PDB Compounds: (D:) type iv collagen. SCOPe Domain Sequences for d1t60d2:. Sequence; same for both SEQRES and ATOM records: ( ... Superfamily d.169.1: C-type lectin-like [56436] (9 families) *. Family d.169.1.6: Noncollagenous (NC1) domain of collagen IV [ ... PDB Description: Crystal structure of Type IV collagen NC1 domain from bovine lens capsule ... Protein Noncollagenous (NC1) domain of collagen IV [75586] (2 species). *. Species Cow (Bos taurus) [TaxId:9913] [82820] (3 PDB ...
Reinhardt DP, Mann K, Nischt R, Fox JW, Chu ML, Krieg T, Timpl R. (1993). Mapping of nidogen binding sites for collagen type IV ... 1991). Recombinant nidogen consists of three globular domains and mediates binding of laminin to collagen type IV. EMBO J 10: ... Areida SK, Reinhardt DP, Müller PK, Fietzek PP, Köwitz J, Marinkovich MP, Notbohm H. (2001). Properties of the collagen type ... Molecular structure and interaction of recombinant human type XVI collagen. J Mol Biol 339: 835-853. Abstract ...
Name: collagen, type IV, alpha 4. Synonyms: E130010M05Rik, [a]4(IV). Type: Gene ... Name: calcium channel, voltage-dependent, L type, alpha 1C subunit. Synonyms: L-type Cav1.2, (alpha)1 subunit, Cav1.2, Cchl1a1 ... When maintaining a live colony, heterozygous mice may be bred together, bred with wild-type siblings, or bred with C57BL/6J ... Recovered litter4; additional fees for any special requests.. Cryopreserved material may be available upon request, please ...
2022) Vascular collagen type-IV in hypertension and cerebral small vessel disease. Stroke, 53(12), pp. 3696-3705. (doi: 10.1161 ... 2022) Vascular collagen type-IV in hypertension and cerebral small vessel disease. Stroke, 53(12), pp. 3696-3705. (doi: 10.1161 ... Graham, D. , Koh-Tan, H. H. C. and Dominiczak, A. F. (2010) Reduced renal glutathione S-transferase mu type 1 expression in the ... Graham, D. , Koh-Tan, H. H. C. and Dominiczak, A. F. (2010) Reduced renal glutathione S-transferase mu type 1 expression in the ...
... collagen type IV, heparin sulfate proteoglycan, entactin, and other minor components. Addition of collagen type IV to the ECM ... In addition to the control bran sample, two types of pre-treatment procedures-namely, ultrasonic bath and probe-type sonication ... If you culture cells inside, add the cells to the gel prior to plating at a recommended density of 3-4 x 104 cells per mL. To ...
Type IV collagen C4 domain - Wikipedia. The collagen IV C4 domain contains 12 cysteines, and all of them are involved in ... Table 19-5, Some Types of Collagen and Their Properties - Molecular Biology of the Cell - NCBI Bookshelf. Table 19-4, Some ... Most types of intermediate filaments are cytoplasmic, but one type, the lamins, are nuclear. Unlike microtubules, IFs ... Figure 19-47, The intracellular and extracellular events in the formation of a collagen fibril - Molecular Biology of the Cell ...
... often caused by a problem with type IV collagen. The symptoms of problems with collagen can vary greatly. Some people have very ... What Is Collagen?. What Is Collagen?. Collagen (KOL-uh-jin) is a protein in the body. Different types of collagen are in many ... Most of it is type I collagen, found in bones and tendons. But we also have:. *type II collagen, found in cartilage (the ... What Problems Can Happen With Collagen?. Depending on which type of collagen is affected, problems can include:. *osteogenesis ...
  • The alpha-3 subunit (COL4A3) of collagen IV is thought to be the antigen implicated in Goodpasture syndrome, wherein the immune system attacks the basement membranes of the glomeruli and the alveoli upon the antigenic site on the alpha-3 subunit becomes unsequestered due to environmental exposures. (wikipedia.org)
  • Objective -To evaluate expression of the α6 chain of type IV collagen in the glomerular basement membranes (GBM) of healthy dogs. (avma.org)
  • Thermal stability of the helical structure of type IV collagen within basement membranes in situ: determination with a conformation-dependent monoclonal antibody. (rupress.org)
  • To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have employed indirect immunofluorescence histochemistry performed at progressively higher temperatures using a conformation-dependent antibody, IV-IA8. (rupress.org)
  • Collagen type IV molecules assemble to form a sheet-like network which is involved in maintaining the structural integrity of basement membranes. (uchicago.edu)
  • Type IV collagen alpha1-alpha6 chains have important roles in the assembly of basement membranes and are implicated in the pathogenesis of Goodpasture syndrome, an autoimmune disorder, and Alport syndrome, a hereditary renal disease. (ox.ac.uk)
  • Type IV collagen alpha1-1-2 networks play an important role in the basement membranes in virtually all tissues throughout the body, particularly the basement membranes surrounding the body's blood vessels (vasculature). (medlineplus.gov)
  • The type IV collagen network helps the basement membranes interact with nearby cells, playing a role in cell movement (migration), cell growth and division (proliferation), cell maturation (differentiation), and the survival of cells. (medlineplus.gov)
  • This alteration in type IV collagen prevents protein networks from forming and basement membranes from developing properly, which causes the tissues they support to weaken. (medlineplus.gov)
  • This gene encodes the major type IV alpha collagen chain of basement membranes. (antibodies-online.com)
  • Lastly, the type IV collagen molecules bind together to form a complex protein network. (wikipedia.org)
  • Lastly, we revealed that addition of type IV collagen protein induced myofibroblast proliferation and migration in monolayer culture and increased the formation of mesenchymal-epithelial septal-like structures in co-culture. (biomedcentral.com)
  • d - i Type IV collagen protein and mRNA expression in the lung. (biomedcentral.com)
  • The predominant form of the protein is comprised of two alpha1(IV) subunits and one alpha2(IV) subunit, however, at least six different alpha subunits can be incorporated into the heterotrimer. (uchicago.edu)
  • SVEVs isolated from lyophilized venoms collected from four different species of snakes ( Agkistrodon contortrix contortrix , Crotalus atrox , Crotalus viridis and Crotalus cerberus oreganus ) were analyzed by mass spectrometry-based proteomic, which allowed the identification of proteins belonging to eight main functional protein classes such as SVMPs, serine proteinases, PLA 2 , LAAO, 5′nucleotidase, C-type lectin, CRISP and Disintegrin. (nature.com)
  • The COL4A1 gene provides instructions for making one component of type IV collagen, which is a flexible protein important in the structure of many tissues throughout the body. (medlineplus.gov)
  • Type IV collagen molecules attach to each other to form complex protein networks. (medlineplus.gov)
  • Most of the identified COL4A1 gene mutations that cause COL4A1 -related brain small-vessel disease change one of the protein building blocks (amino acids) used to make the alpha1(IV) chain of type IV collagen. (medlineplus.gov)
  • Collagen (KOL-uh-jin) is a protein in the body. (kidshealth.org)
  • ECM was prepared to a protein concentration of 8-12 mg/mL (in DMEM), containing laminin as a major component, collagen type IV, heparin sulfate proteoglycan, entactin, and other minor components. (sigmaaldrich.com)
  • Collagen is a protein that increases the skin's elasticity, enabling it to bounce back into its original shape. (nivea.co.uk)
  • This test detects a denatured 290-kd skin basement membrane protein or globular chain of the alpha chain (145 kd) of type VII collagen. (medscape.com)
  • Anti-Collagen Type IV has been prepared by immunoaffinity chromatography using immobilized antigens followed by extensive cross-adsorption against other collagens, human serum proteins and non-collagen extracellular matrix proteins to remove any unwanted specificities. (rockland.com)
  • Non-specific cross-reaction of anti-collagen antibodies with other human serum proteins or non-collagen extracellular matrix proteins is negligible. (rockland.com)
  • When compared to parental and control samples, skin fibroblasts of the proband synthesized two populations of type I collagen molecules. (wustl.edu)
  • The Goodpasture epitopes are structurally sequestered by the adjacent alpha-4(IV)NC1 and alpha-5(IV)NC1 molecules. (medscape.com)
  • the expression of type 1 and type 4 collagens and SVCT2 mRNA was enhanced, and type 1 procollagen synthesis increased. (nih.gov)
  • Thus, these results indicate that human skin fibroblasts exposed to AA over time had rising levels of type 1/type 4 collagens and SVCT2 mRNA expression and type 1 procollagen synthesis. (nih.gov)
  • The mRNA of the patient was probed with overlapping antisense riboprobes to type I collagen cDNA. (wustl.edu)
  • citation needed] Parallel direction of fibers in Type I Depending on genetic and nongenetic factors including alterations in gene expression, splice variations, post-translational modifications, and the chain-specific assembly of particular α-chains, different organs can be affected during their development and in the adult life span. (wikipedia.org)
  • Ascorbic acid (AA) is essential for collagen biosynthesis as a cofactor for prolyl and lysyl hydroxylase and as a stimulus for collagen gene expression. (nih.gov)
  • Moreover, we determined the effects on type 1 and type 4 collagen and sodium-dependent vitamin C transporter (SVCT) gene expression when medium containing 100 μM AA was replaced every 24h for 5 days to avoid depletion of AA. (nih.gov)
  • Specifically, this gene makes the alpha1(IV) chain of type IV collagen. (medlineplus.gov)
  • Most kids with a collagen problem have it because they inherited a gene from one or both of their parents. (kidshealth.org)
  • Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. (antibodies-online.com)
  • 2 ). CA-MRSA clones that have spread worldwide share SCC mec type IV, the smallest cassette containing the mecA gene coding for methicillin resistance. (cdc.gov)
  • mined by multilocus sequence typing, and an agr (for Christian Martin,* Nadia Liassine,¶ accessory gene regulator) allele of type 3. (cdc.gov)
  • Cause is a gene mutation affecting type IV collagen. (msdmanuals.com)
  • The collagen IV C4 domain at the C-terminus is not removed in post-translational processing, and the fibers link head-to-head, rather than in parallel. (wikipedia.org)
  • The mesohyl includes a noncellular colloidal mesoglea with embedded collagen fibers, spicules and various cells, being as such a type of mesenchyme. (pearltrees.com)
  • Anchoring fibers composed of type IV collagen extend from the basal lamina into the underlying reticular lamina and loop around collagen bundles. (wikidoc.org)
  • Because Radiofrequency (RF) energy has been shown to renew and restore spatial structural arrangement of collagen fibers, treatment of ED with RF could lead to anatomical and physiological changes at the penile tissue level and could lead to improvement in the erectile mechanism. (researchgate.net)
  • We conclude that the stability of the helical structure of type IV collagen within a basement membrane is considerably greater than it is in solution, and that conformation-dependent monoclonal antibodies can be useful probes for investigations of molecular structure in situ. (rupress.org)
  • Rockland produces highly active antibodies and conjugates to collagens. (rockland.com)
  • For these reasons, it is often extremely difficult to generate antibodies with specificities to collagens. (rockland.com)
  • The development of 'type' specific antibodies is dependent on NON-DENATURED three-dimensional epitopes. (rockland.com)
  • Antibodies are isolated from rabbit antiserum and are extensively cross-adsorbed by immunoaffinity purification to produce 'type' specific antibodies. (rockland.com)
  • Antibodies mediated towards what collagen type leads to the condition depicted in the image? (nextstepsinderm.com)
  • Anti-glomerular basement membrane (anti-GBM) antibody disease is a rare autoimmune disorder in which circulating antibodies are directed against an antigen normally present in the GBM and alveolar basement membrane, specifically the alpha-3 chain of type IV collagen. (medscape.com)
  • The principal targets for anti-GBM antibodies are two adjacent, conformational disulfide-bond-dependent regions in the NC1 domain of the alpha-3 chain of type IV collagen. (medscape.com)
  • New discoveries keep unraveling information about genetic mutations, biosynthesis, molecular assembly, and network formation of type IV collagen, and this increases the understanding of the critical role of this collagen in health and disease. (wikipedia.org)
  • Alport syndrome is a rare genetic disorder caused by mutations in three human genes involved in type IV collagen biosynthesis. (aao.org)
  • There are six human genes associated with it: COL4A1, COL4A2, COL4A3, COL4A4, COL4A5, COL4A6 Type IV collagen is a type of collagen that is responsible for providing a scaffold for stability and assembly. (wikipedia.org)
  • No specific or efficient treatment exists for Alport syndrome, an X-linked hereditary disease caused by mutations in collagen type IV, a crucial component of the glomerular basement membrane. (hindawi.com)
  • The collagen molecule is then formed. (wikipedia.org)
  • This chain combines with another alpha1 chain and a different type of alpha (IV) chain called alpha2 to make a complete type IV collagen alpha1-1-2 molecule. (medlineplus.gov)
  • The substitution of another amino acid for glycine in the alpha1(IV) chain prevents this chain from combining with other chains to form a complete type IV collagen molecule. (medlineplus.gov)
  • The basic monomer of this network is a triple-helical molecule composed of 3 alpha chains (ie, alpha-3, alpha-4, and alpha-5). (medscape.com)
  • it interacts with noncollagenous domains of the alpha-4 and alpha-5 chains to form the alpha-3.alpha-4.alpha-5(IV) triple helical molecule known as promoter, which, in turn, dimerizes to form a hexameric structure that is extensively crosslinked. (medscape.com)
  • 2022). Pathomechanisms in corner fracture type spondylometaphyseal dysplasia. (mcgill.ca)
  • Results -Immunolabeling of the α6(IV) chain was not observed in GBM of 6 dogs ≤ 30 months old but was observed in GBM of the remaining 6 dogs, all of which were ≥ 45 months old. (avma.org)
  • Expression of the α6(IV) chain was not observed in GBM of the human subjects, regardless of the age of the subject. (avma.org)
  • Conclusions and Clinical Relevance -Results indicate that the α6(IV) chain is expressed in GBM of healthy dogs, but the expression is age-dependent. (avma.org)
  • These residues accumulate opposite charge in subdomain B of alpha1 (positive) and alpha2 (negative) sequences and may play a role in the stoichiometric chain selection upon type IV collagen assembly. (ox.ac.uk)
  • Specifically, the mutations replace the amino acid glycine with a different amino acid at one of various places in this collagen chain. (medlineplus.gov)
  • The finding of a glycine substitution in a α1(I) chain of a patient with the milder type IV osteogenesis imperfecta phenotype requires modification of current molecular models for type II and IV osteogenesis imperfecta. (wustl.edu)
  • In most patients, the autoantibody in Goodpasture syndrome is directed against a 28-kd monomeric subunit present within the noncollagenous domain of the alpha3 chain of type IV collagen (alpha3[IV]NC1). (medscape.com)
  • Alport syndrome is a nephritic syndrome caused by a mutation in the COL4A3 , COL4A4 , and COL4A5 genes that encode the alpha-5 chain of type IV collagen and results in altered type IV collagen strands. (msdmanuals.com)
  • Also, collagen IV lacks the regular glycine in every third residue necessary for the tight, collagen helix. (wikipedia.org)
  • It also lacks a glycine in every third amino acid residue that is responsible for the tight collagen helix, as a result it will be more flexible and kinked than other types of collagen. (wikipedia.org)
  • Tight collagen helix The most common collagen is type I collagen which makes up 90% of all collagen. (wikipedia.org)
  • This predicts that the mutation delaying helix formation is near the carboxyl-terminal end of one of the component chains of type I collagen. (wustl.edu)
  • The building blocks are composed of three alpha subunits of collagen, which form a triple helix. (medscape.com)
  • The six α-chains of collagen IV can recognize each other with incredible specificity and will assemble into unique heterotrimers. (wikipedia.org)
  • They are classified into 5 groups according to substrate specificity and internal homology: collagenases, gelatinases, stromelysins, membrane-type MMPs, and others, including matrilysins 8 . (bvsalud.org)
  • The inferred tree verified that type IV collagen sequences fall into two groups, alpha1-like and alpha2-like, and suggested that vertebrate alpha3/alpha4 sequences evolved before alpha1/alpha2 and alpha5/alpha6. (ox.ac.uk)
  • Type IV collagen can be expressed as six different chains, alpha1 to alpha6. (medscape.com)
  • Through interactions with specific cellular receptors such as integrins, the basement membrane collagen IV networks not only provide structural support to the cells and tissues, but they also affect the biological rate during and after the development. (wikipedia.org)
  • Some class-specific anti-collagens may be specific for three-dimensional epitopes which may result in diminished reactivity with denatured collagen or formalin-fixed, paraffin embedded tissues. (rockland.com)
  • In addition to its role in the formation of epithelium and vasculature, type IV collagen appears to be key for alveolar myofibroblast development by inducing their proliferation, differentiation and migration throughout the developing septum. (biomedcentral.com)
  • Composition and structural organization of type IV collagen in the GBM of healthy adult dogs is different from that described for other species. (avma.org)
  • Comparative analysis of the noncollagenous NC1 domain of type IV collagen: identification of structural features important for assembly, function, and pathogenesis. (ox.ac.uk)
  • Here we show that synchrotron radiation (SR)-based microcomputed tomography (μCT) with phase contrast enhancement can resolve the collagen fibre structure of meniscus tissue, including fibre crimping and structural changes related to degeneration (Paper IV). (lu.se)
  • Mutations to the genes[COL4A5] coding for collagen IV lead to Alport syndrome. (wikipedia.org)
  • It is due to different mutations in collagen IV [ 1 ]. (hindawi.com)
  • After analysis of deduced amino acid sequences from cloned cDNAs of dipeptidyl peptidase IV (DPP IV) and aminopeptidase A (APA), it was noticed that DPP IV and APA are type II membrane proteins that have one transmembrane domain near the N-terminus. (nature.com)
  • Anti-Collagen Type IV has been tested by dot blot and IHC and is suitable for indirect trapping ELISA for quantitation of antigen in serum using a standard curve, immunoprecipitation, native (non-denaturing, non-dissociating) PAGE, immunohistochemistry, and western blotting for highly sensitive qualitative analysis. (rockland.com)
  • Discard eye collagen pads after use and gently pat the remaining serum into the skin. (olrom.com)
  • Peri-treatment dynamics of serum levels of type IV collagen 7S fragment (4COL7S), a fibrosis marker, and subsequent clinical outcomes, including hepatic decompensation, newly emerged hepatocellular carcinoma (HCC), and all-cause mortality were analyzed. (elsevierpure.com)
  • Serum leptin, a cytokine-type peptide hormone mainly produced by adipocytes, may play an important role in the pathogenesis of steatosis. (medscape.com)
  • Indirect immunofluorescence demonstrates the presence of IgG circulating autoantibodies in the patient's serum that target the skin basement membrane component, type VII collagen. (medscape.com)
  • To summarize, the process of collagen synthesis occurs mainly in the cells of fibroblasts which are specialized cells with the main function of synthesizing collagen. (wikipedia.org)
  • Blue cells = expressed in wild-type. (jax.org)
  • Many studies have evaluated the relationship between AA and collagen expression in short- and long-term effects on cells after a single administration of AA into the culture medium. (nih.gov)
  • Produced by a variety of cell types, extracellular vesicles (EVs) are able to transfer lipids, nucleic acids and proteins to recipient cells. (nature.com)
  • If you culture cells inside, add the cells to the gel prior to plating at a recommended density of 3-4 x 10 4 cells per mL. (sigmaaldrich.com)
  • The MTT assay, a colorimetric method of determining cell viability, is based on reduction of the yellow tetrazolium salt (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to a blue formazan salt by mitochondrial succinate dehydrogenase in viable cells. (europa.eu)
  • Matrix metalloproteases (MMPs) are zinc-dependent proteinases that participate in extracellular matrix degradation 1-3 and favor the invasion and proliferation of tumor cells 4 . (bvsalud.org)
  • Procedure -Sections were immunolabeled with a monospecific antibody that cross-reacts with human and canine α6(IV) chains and examined by means of fluorescence microscopy. (avma.org)
  • This antibody reacts with most mammalian Type IV collagens and has negligible cross-reactivity with Type I, II, III, V or VI collagens. (rockland.com)
  • This is a classic type II reaction in the Gell and Coombs classification of antigen-antibody reactions. (medscape.com)
  • 4COL7S-defined fibrosis progression at SVR and a baseline platelet count less than 10×10 4 /μL were significantly predicted all-cause mortality (P = 0.0051). (elsevierpure.com)
  • Rockland extensively purifies collagens for immunization from human and bovine placenta and cartilage by limited pepsin digestion and selective salt precipitation. (rockland.com)
  • This restorative system includes four essential collagen types and hyaluronic acid, lubricating joints and bathing them in factors that promote regeneration and repair of cartilage. (vitacost.com)
  • However, in a phantom study in this thesis, gagCEST demonstrated a low sensitivity to the type of GAG most abundant in mature human articular cartilage (Paper III). (lu.se)
  • Collagen IV (ColIV or Col4) is a type of collagen found primarily in the basal lamina. (wikipedia.org)
  • These two features cause the collagen to form in a sheet, the form of the basal lamina. (wikipedia.org)
  • Other than water, the mesoglea is composed of several substances including fibrous proteins like collagen and heparan sulphate proteoglycans. (pearltrees.com)
  • Other investigative studies available that further document the diagnosis of epidermolysis bullosa acquisita (EBA) include direct and indirect immunoelectron microscopy, immunoblotting, enzyme-linked immunosorbent assay (ELISA), immunoprecipitation, and type IV collagen immunomapping. (medscape.com)
  • We have identified a point mutation in one α1(I) collagen allele (COL1A1) of a child with the type IV osteogenesis imperfecta phenotype. (wustl.edu)
  • We report a new the United States are ST1 and agr allele type 3, but some fatal case of necrotizing pneumonia. (cdc.gov)
  • An S. aureus strain are ST8 or ST59 and agr allele type 1 ( 2 ). (cdc.gov)
  • Here we report with an agr 1 allele and of a new sequence type 377 was a fatal case of necrotizing pneumonia involving a 59-year- recovered, representing a new, emerging, community- old woman infected by a new clone of PVL-positive CA- acquired methicillin-resistant clone. (cdc.gov)
  • Circulating type IV collagen (COLIV) is a new potential CLM marker. (bvsalud.org)
  • COLIV levels were also related to the type of CLM. (bvsalud.org)
  • COLIV and CEA levels were analysed, and the type of CLM was classified using paraffinated tissue . (bvsalud.org)
  • By preserving the extracellular matrix, including vascular channels, SimpliDerm facilitates angiogenesis, resulting in new collagen formation, revascularization and host cell repopulation. (sientra.com)
  • 24K colloidal gold in these collagen eye patches safely rejuvenates the skin while increasing elasticity and diminishing fine lines and wrinkles. (olrom.com)
  • Endostatin is derived from the noncollagenous domain 1 (NC1) at the C-terminus of collagen type XVIII. (who.int)
  • Osteogenesis imperfecta type IV. (wustl.edu)
  • Dive into the research topics of 'Osteogenesis imperfecta type IV. (wustl.edu)
  • Collagens are highly conserved throughout evolution and are characterized by an uninterrupted ''Glycine-X-Y'' triplet repeat that is a necessary part of the triple helical structure. (rockland.com)
  • N-terminal amino acid sequence analysis of the purified DPP IV revealed that the N-terminus is not processed. (nature.com)
  • It is found in all dermal layers at high proportions while type IV collagen is only found at the basement membrane of the epidermal junction. (wikipedia.org)
  • 4] Though they share common elements, their tissue distribution and binding kinetics are quite different, reflecting their divergent roles in various pathophysiological processes. (pearltrees.com)
  • Addition of collagen type IV to the ECM gel increases polymerization. (sigmaaldrich.com)
  • Heart failure (signs and symptoms, diagnosis) 4. (muni.cz)
  • Type IV collagen is the main component of the basement membrane that gives strength to the blood-gas barrier (BGB). (biomedcentral.com)
  • Collagen is an essential component of the structures involved in the erectile mechanism and as such, impaired collagen may hinder it. (researchgate.net)
  • The principal component of basement membrane is type IV collagen, which acts as a support structure and is composed of building blocks that are linked end-to-end. (medscape.com)
  • Formation of the resilient alpha-3.alpha-4.alpha-5(IV) network is essential for the proper function of the basement membrane. (medscape.com)
  • Investigation of the cryptic nature of the Goodpasture epitopes revealed 2 types of alpha-3.alpha-4.alpha-5(IV) hexamers: the autoantibody reactive M-hexamers and the autoantibody impenetrable D-hexamers. (medscape.com)
  • Thus, differences of the alpha-3(IV)NC1 monomer-dimer composition in the alveolar basement membrane observed between individuals may explain why some patients with Goodpasture syndrome do not develop pulmonary disease. (medscape.com)
  • [ 4 ] The epitopes, designated EA and EB, are located in the NC1 domain at the amino acid residues 17-31 and 127-141, respectively. (medscape.com)
  • Collagen IV has been the focus of extensive research ranging from biochemistry perspectives, to pathology, and genetic disorders. (wikipedia.org)
  • Two collagen IV protomers associate through the carboxy-terminal NC1 trimer to form the NC1 hexamer. (wikipedia.org)
  • These interactions form the core of the type IV collagen scaffold. (wikipedia.org)
  • ELISA is preferred over immunoblotting because the ELISA method uses nondenatured type VII collagen, usually in a recombinant form. (medscape.com)