The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.
A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.
Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (PAPAIN; TRYPSIN; or CHYMOTRYPSIN) at well-localized regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin S-1 and myosin S-2. S-1 contains the heads of the heavy chains plus the light chains and S-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod).
The subfamily of myosin proteins that are commonly found in muscle fibers. Myosin II is also involved a diverse array of cellular functions including cell division, transport within the GOLGI APPARATUS, and maintaining MICROVILLI structure.
The smaller subunits of MYOSINS that bind near the head groups of MYOSIN HEAVY CHAINS. The myosin light chains have a molecular weight of about 20 KDa and there are usually one essential and one regulatory pair of light chains associated with each heavy chain. Many myosin light chains that bind calcium are considered "calmodulin-like" proteins.
The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.
A nonmuscle isoform of myosin type II found predominantly in neuronal tissue.
A nonmuscle isoform of myosin type II found predominantly in platelets, lymphocytes, neutrophils and brush border enterocytes.
A subclass of myosin involved in organelle transport and membrane targeting. It is abundantly found in nervous tissue and neurosecretory cells. The heavy chains of myosin V contain unusually long neck domains that are believed to aid in translocating molecules over large distances.
Isoforms of MYOSIN TYPE II, specifically found in the ventricular muscle of the HEART. Defects in the genes encoding ventricular myosins result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.
Myosin type II isoforms found in cardiac muscle.
Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.
Contractile tissue that produces movement in animals.
Skeletal muscle fibers characterized by their expression of the Type II MYOSIN HEAVY CHAIN isoforms which have high ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment. Several fast types have been identified.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
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.
Myosin type II isoforms found in smooth muscle.
A subclass of myosins found generally associated with actin-rich membrane structures such as filopodia. Members of the myosin type I family are ubiquitously expressed in eukaryotes. The heavy chains of myosin type I lack coiled-coil forming sequences in their tails and therefore do not dimerize.
Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
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.
Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.
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.
Myosin type II isoforms found in skeletal muscle.
The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .
The heavy chain subunits of clathrin.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
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 protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.
An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and CALMODULIN. The 20-kDa light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. The enzyme plays a central role in the regulation of smooth muscle contraction.
A disorder of immunoglobulin synthesis in which large quantities of abnormal heavy chains are excreted in the urine. The amino acid sequences of the N-(amino-) terminal regions of these chains are normal, but they have a deletion extending from part of the variable domain through the first domain of the constant region, so that they cannot form cross-links to the light chains. The defect arises through faulty coupling of the variable (V) and constant (C) region genes.
The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
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.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).
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.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.
'Gizzard', in a medical context, is a term rarely used but can refer to the muscular stomach of a bird, responsible for grinding and macerating food with the aid of ingested pebbles or grit.
The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
Ordered rearrangement of B-lymphocyte variable gene regions of the IMMUNOGLOBULIN HEAVY CHAINS, thereby contributing to antibody diversity. It occurs during the first stage of differentiation of the IMMATURE B-LYMPHOCYTES.
Myosin type II isoforms specifically found in the atrial muscle of the heart.
Polypeptide chains, consisting of 211 to 217 amino acid residues and having a molecular weight of approximately 22 kDa. There are two major types of light chains, kappa and lambda. Two Ig light chains and two Ig heavy chains (IMMUNOGLOBULIN HEAVY CHAINS) make one immunoglobulin molecule.
A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.
A class of organic compounds containing four or more ring structures, one of which is made up of more than one kind of atom, usually carbon plus another atom. The heterocycle may be either aromatic or nonaromatic.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Fibers composed of MICROFILAMENT PROTEINS, which are predominately ACTIN. They are the smallest of the cytoskeletal filaments.
The rate dynamics in chemical or physical systems.
A masticatory muscle whose action is closing the jaws.
The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.
The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
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.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
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.
That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.
Heavy chains of IMMUNOGLOBULIN G having a molecular weight of approximately 51 kDa. They contain about 450 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the Fc fragment constant region. The gamma heavy chain subclasses (for example, gamma 1, gamma 2a, and gamma 2b) of the IMMUNOGLOBULIN G isotype subclasses (IgG1, IgG2A, and IgG2B) resemble each other more closely than the heavy chains of the other IMMUNOGLOBULIN ISOTYPES.
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 subclass of myosins originally found in the photoreceptor of DROSOPHILA. The heavy chains can occur as two alternatively spliced isoforms of 132 and 174 KDa. The amino terminal of myosin type III is highly unusual in that it contains a protein kinase domain which may be an important component of the visual process.
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.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
A myogenic regulatory factor that controls myogenesis. Though it is not clear how its function differs from the other myogenic regulatory factors, MyoD appears to be related to fusion and terminal differentiation of the muscle cell.
Genes and gene segments encoding the IMMUNOGLOBULIN HEAVY CHAINS. Gene segments of the heavy chain genes are symbolized V (variable), D (diversity), J (joining), and C (constant).
The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.
A genus of ameboid protozoa. Characteristics include a vesicular nucleus and the formation of several lodopodia, one of which is dominant at a given time. Reproduction occurs asexually by binary fission.
The sum of the weight of all the atoms in a molecule.
Technique for limiting use, activity, or movement by immobilizing or restraining animal by suspending from hindlimbs or tails. This immobilization is used to simulate some effects of reduced gravity and study weightlessness physiology.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A family of multisubunit cytoskeletal motor proteins that use the energy of ATP hydrolysis to power a variety of cellular functions. Dyneins fall into two major classes based upon structural and functional criteria.
The class of heavy chains found in IMMUNOGLOBULIN M. They have a molecular weight of approximately 72 kDa and they contain about 57 amino acid residues arranged in five domains and have more oligosaccharide branches and a higher carbohydrate content than the heavy chains of IMMUNOGLOBULIN G.
The hollow, muscular organ that maintains the circulation of the blood.
Established cell cultures that have the potential to propagate indefinitely.
The striated muscle groups which move the LARYNX as a whole or its parts, such as altering tension of the VOCAL CORDS, or size of the slit (RIMA GLOTTIDIS).
Genes encoding the different subunits of the IMMUNOGLOBULINS, for example the IMMUNOGLOBULIN LIGHT CHAIN GENES and the IMMUNOGLOBULIN HEAVY CHAIN GENES. The heavy and light immunoglobulin genes are present as gene segments in the germline cells. The completed genes are created when the segments are shuffled and assembled (B-LYMPHOCYTE GENE REARRANGEMENT) during B-LYMPHOCYTE maturation. The gene segments of the human light and heavy chain germline genes are symbolized V (variable), J (joining) and C (constant). The heavy chain germline genes have an additional segment D (diversity).
The parts of a macromolecule that directly participate in its specific combination with another molecule.
A myogenic regulatory factor that controls myogenesis. Myogenin is induced during differentiation of every skeletal muscle cell line that has been investigated, in contrast to the other myogenic regulatory factors that only appear in certain cell types.
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).
A phosphoprotein phosphatase that is specific for MYOSIN LIGHT CHAINS. It is composed of three subunits, which include a catalytic subunit, a myosin binding subunit, and a third subunit of unknown function.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
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.
Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.
Antibodies produced by a single clone of cells.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
A family of muscle-specific transcription factors which bind to DNA in control regions and thus regulate myogenesis. All members of this family contain a conserved helix-loop-helix motif which is homologous to the myc family proteins. These factors are only found in skeletal muscle. Members include the myoD protein (MYOD PROTEIN); MYOGENIN; myf-5, and myf-6 (also called MRF4 or herculin).
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
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.
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.
A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA.
Large woodland game BIRDS in the subfamily Meleagridinae, family Phasianidae, order GALLIFORMES. Formerly they were considered a distinct family, Melegrididae.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A 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.
Catalyzes the reduction of tetrazolium compounds in the presence of NADH.
An intermediate filament protein found predominantly in smooth, skeletal, and cardiac muscle cells. Localized at the Z line. MW 50,000 to 55,000 is species dependent.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
A form of CARDIAC MUSCLE disease, characterized by left and/or right ventricular hypertrophy (HYPERTROPHY, LEFT VENTRICULAR; HYPERTROPHY, RIGHT VENTRICULAR), frequent asymmetrical involvement of the HEART SEPTUM, and normal or reduced left ventricular volume. Risk factors include HYPERTENSION; AORTIC STENOSIS; and gene MUTATION; (FAMILIAL HYPERTROPHIC CARDIOMYOPATHY).
Muscular contractions characterized by increase in tension without change in length.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
The domains of the immunoglobulin molecules that are invariable in their amino acid sequence within any class or subclass of immunoglobulin. They confer biological as well as structural functions to immunoglobulins. One each on both the light chains and the heavy chains comprises the C-terminus half of the IMMUNOGLOBULIN FAB FRAGMENT and two or three of them make up the rest of the heavy chains (all of the IMMUNOGLOBULIN FC FRAGMENT)
The nonstriated involuntary muscle tissue of blood vessels.
The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.
Embryonic (precursor) cells of the myogenic lineage that develop from the MESODERM. They undergo proliferation, migrate to their various sites, and then differentiate into the appropriate form of myocytes (MYOCYTES, SKELETAL; MYOCYTES, CARDIAC; MYOCYTES, SMOOTH MUSCLE).
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
A giant elastic protein of molecular mass ranging from 2,993 kDa (cardiac), 3,300 kDa (psoas), to 3,700 kDa (soleus) having a kinase domain. The amino- terminal is involved in a Z line binding, and the carboxy-terminal region is bound to the myosin filament with an overlap between the counter-connectin filaments at the M line.
A transmembrane glycoprotein subunit that can dimerize with a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS). This protein subunit serves a diverse array of functions including amino acid transport and cell fusion. Its function is altered depending which of the light chain subunits it interacts with.
A thiourea antithyroid agent. Propythiouracil inhibits the synthesis of thyroxine and inhibits the peripheral conversion of throxine to tri-iodothyronine. It is used in the treatment of hyperthyroidism. (From Martindale, The Extra Pharmacopeoia, 30th ed, p534)
The resection or removal of the innervation of a muscle or muscle tissue.
The class of heavy chains found in IMMUNOGLOBULIN A. They have a molecular weight of approximately 58 kDa and contain about 470 amino acid residues arranged in four domains and an oligosaccharide component bound covalently to their Fc fragment constant region.
A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.
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.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Acquired, familial, and congenital disorders of SKELETAL MUSCLE and SMOOTH MUSCLE.
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.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
An autosomal dominant inherited form of HYPERTROPHIC CARDIOMYOPATHY. It results from any of more than 50 mutations involving genes encoding contractile proteins such as VENTRICULAR MYOSINS; cardiac TROPONIN T; ALPHA-TROPOMYOSIN.
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.
Monomeric subunits of primarily globular ACTIN and found in the cytoplasmic matrix of almost all cells. They are often associated with microtubules and may play a role in cytoskeletal function and/or mediate movement of the cell or the organelles within the cell.
One of the minor protein components of skeletal muscle. Its function is to serve as the calcium-binding component in the troponin-tropomyosin B-actin-myosin complex by conferring calcium sensitivity to the cross-linked actin and myosin filaments.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
Proteins prepared by recombinant DNA technology.
Elements of limited time intervals, contributing to particular results or situations.
A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.
Contractile activity of the MYOCARDIUM.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
Refers to animals in the period of time just after birth.
Proteins which bind calmodulin. They are found in many tissues and have a variety of functions including F-actin cross-linking properties, inhibition of cyclic nucleotide phosphodiesterase and calcium and magnesium ATPases.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
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.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.
Proteins which participate in contractile processes. They include MUSCLE PROTEINS as well as those found in other cells and tissues. In the latter, these proteins participate in localized contractile events in the cytoplasm, in motile activity, and in cell aggregation phenomena.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
Proteins found in any species of protozoan.
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.
A substituted phenylaminoethanol that has beta-2 adrenomimetic properties at very low doses. It is used as a bronchodilator in asthma.
Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
Activating transcription factors of the MADS family which bind a specific sequence element (MEF2 element) in many muscle-specific genes and are involved in skeletal and cardiac myogenesis, neuronal differentiation and survival/apoptosis.
A masticatory muscle whose action is closing the jaws; its posterior portion retracts the mandible.
Hypersecretion of THYROID HORMONES from the THYROID GLAND. Elevated levels of thyroid hormones increase BASAL METABOLIC RATE.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.
The pectoralis major and pectoralis minor muscles that make up the upper and fore part of the chest in front of the AXILLA.
General increase in bulk of a part or organ due to CELL ENLARGEMENT and accumulation of FLUIDS AND SECRETIONS, not due to tumor formation, nor to an increase in the number of cells (HYPERPLASIA).
The measurement of an organ in volume, mass, or heaviness.
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.
One of two types of muscle in the body, characterized by the array of bands observed under microscope. Striated muscles can be divided into two subtypes: the CARDIAC MUSCLE and the SKELETAL MUSCLE.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC 4.1.3.7.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.
Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.
One of the types of light chains of the immunoglobulins with a molecular weight of approximately 22 kDa.
Transport proteins that carry specific substances in the blood or across cell membranes.
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.
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.
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.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.
A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.
Serum proteins that have the most rapid migration during ELECTROPHORESIS. This subgroup of globulins is divided into faster and slower alpha(1)- and alpha(2)-globulins.
The quadriceps femoris. A collective name of the four-headed skeletal muscle of the thigh, comprised of the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
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 protein factor that regulates the length of R-actin. It is chemically similar, but immunochemically distinguishable from actin.
Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
An 11-kDa protein associated with the outer membrane of many cells including lymphocytes. It is the small subunit of the MHC class I molecule. Association with beta 2-microglobulin is generally required for the transport of class I heavy chains from the endoplasmic reticulum to the cell surface. Beta 2-microglobulin is present in small amounts in serum, csf, and urine of normal people, and to a much greater degree in the urine and plasma of patients with tubular proteinemia, renal failure, or kidney transplants.
Non-striated, elongated, spindle-shaped cells found lining the digestive tract, uterus, and blood vessels. They are derived from specialized myoblasts (MYOBLASTS, SMOOTH MUSCLE).
Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.
Precursor cells destined to differentiate into skeletal myocytes (MYOCYTES, SKELETAL).
A group of intracellular-signaling serine threonine kinases that bind to RHO GTP-BINDING PROTEINS. They were originally found to mediate the effects of rhoA GTP-BINDING PROTEIN on the formation of STRESS FIBERS and FOCAL ADHESIONS. Rho-associated kinases have specificity for a variety of substrates including MYOSIN-LIGHT-CHAIN PHOSPHATASE and LIM KINASES.
A proteolytic enzyme obtained from Carica papaya. It is also the name used for a purified mixture of papain and CHYMOPAPAIN that is used as a topical enzymatic debriding agent. EC 3.4.22.2.
Sites on an antigen that interact with specific antibodies.
Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.
Abnormal immunoglobulins characteristic of MULTIPLE MYELOMA.
Any discrete, presumably solitary, mass of neoplastic PLASMA CELLS either in BONE MARROW or various extramedullary sites.
The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.
Heterodimeric transcription factors containing a DNA-binding alpha subunits, (CORE BINDING FACTOR ALPHA SUBUNITS), along with a non-DNA-binding beta subunits, CORE BINDING FACTOR BETA SUBUNIT. Core Binding Factor regulates GENETIC TRANSCRIPTION of a variety of GENES involved primarily in CELL DIFFERENTIATION and CELL CYCLE progression.
Muscular Dystrophy, Animal: A group of genetic disorders causing progressive skeletal muscle weakness and degeneration, characterized by the lack of or defective dystrophin protein, which can also affect other organ systems such as heart and brain, occurring in various forms with different degrees of severity and age of onset, like Duchenne, Becker, Myotonic, Limb-Girdle, and Facioscapulohumeral types, among others.
Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.
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 T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3.
A non-DNA binding transcription factor that is a subunit of core binding factor. It forms heterodimeric complexes with CORE BINDING FACTOR ALPHA SUBUNITS, and regulates GENETIC TRANSCRIPTION of a variety of GENES involved primarily in CELL DIFFERENTIATION and CELL CYCLE progression.
One of the three polypeptide chains that make up the TROPONIN complex. It inhibits F-actin-myosin interactions.
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.

Evidence for F-actin-dependent and -independent mechanisms involved in assembly and stability of the medial actomyosin ring in fission yeast. (1/2643)

Cell division in a number of eukaryotes, including the fission yeast Schizosaccharomyces pombe, is achieved through a medially placed actomyosin-based contractile ring. Although several components of the actomyosin ring have been identified, the mechanisms regulating ring assembly are still not understood. Here, we show by biochemical and mutational studies that the S.pombe actomyosin ring component Cdc4p is a light chain associated with Myo2p, a myosin II heavy chain. Localization of Myo2p to the medial ring depended on Cdc4p function, whereas localization of Cdc4p at the division site was independent of Myo2p. Interestingly, the actin-binding and motor domains of Myo2p are not required for its accumulation at the division site although the motor activity of Myo2p is essential for assembly of a normal actomyosin ring. The initial assembly of Myo2p and Cdc4p at the division site requires a functional F-actin cytoskeleton. Once established, however, F-actin is not required for the maintenance of Cdc4p and Myo2p medial rings, suggesting that the attachment of Cdc4p and Myo2p to the division site involves proteins other than actin itself.  (+info)

Regulation of chamber-specific gene expression in the developing heart by Irx4. (2/2643)

The vertebrate heart consists of two types of chambers, the atria and the ventricles, which differ in their contractile and electrophysiological properties. Little is known of the molecular mechanisms by which these chambers are specified during embryogenesis. Here a chicken iroquois-related homeobox gene, Irx4, was identified that has a ventricle-restricted expression pattern at all stages of heart development. Irx4 protein was shown to regulate the chamber-specific expression of myosin isoforms by activating the expression of the ventricle myosin heavy chain-1 (VMHC1) and suppressing the expression of the atrial myosin heavy chain-1 (AMHC1) in the ventricles. Thus, Irx4 may play a critical role in establishing chamber-specific gene expression in the developing heart.  (+info)

Chlamydia infections and heart disease linked through antigenic mimicry. (3/2643)

Chlamydia infections are epidemiologically linked to human heart disease. A peptide from the murine heart muscle-specific alpha myosin heavy chain that has sequence homology to the 60-kilodalton cysteine-rich outer membrane proteins of Chlamydia pneumoniae, C. psittaci, and C. trachomatis was shown to induce autoimmune inflammatory heart disease in mice. Injection of the homologous Chlamydia peptides into mice also induced perivascular inflammation, fibrotic changes, and blood vessel occlusion in the heart, as well as triggering T and B cell reactivity to the homologous endogenous heart muscle-specific peptide. Chlamydia DNA functioned as an adjuvant in the triggering of peptide-induced inflammatory heart disease. Infection with C. trachomatis led to the production of autoantibodies to heart muscle-specific epitopes. Thus, Chlamydia-mediated heart disease is induced by antigenic mimicry of a heart muscle-specific protein.  (+info)

Processing of endogenous pre-mRNAs in association with SC-35 domains is gene specific. (4/2643)

Analysis of six endogenous pre-mRNAs demonstrates that localization at the periphery or within splicing factor-rich (SC-35) domains is not restricted to a few unusually abundant pre-mRNAs, but is apparently a more common paradigm of many protein-coding genes. Different genes are preferentially transcribed and their RNAs processed in different compartments relative to SC-35 domains. These differences do not simply correlate with the complexity, nuclear abundance, or position within overall nuclear space. The distribution of spliceosome assembly factor SC-35 did not simply mirror the distribution of individual pre-mRNAs, but rather suggested that individual domains contain both specific pre-mRNA(s) as well as excess splicing factors. This is consistent with a multifunctional compartment, to which some gene loci and their RNAs have access and others do not. Despite similar molar abundance in muscle fiber nuclei, nascent transcript "trees" of highly complex dystrophin RNA are cotranscriptionally spliced outside of SC-35 domains, whereas posttranscriptional "tracks" of more mature myosin heavy chain transcripts overlap domains. Further analyses supported that endogenous pre-mRNAs exhibit distinct structural organization that may reflect not only the expression and complexity of the gene, but also constraints of its chromosomal context and kinetics of its RNA metabolism.  (+info)

Myogenic signaling of phosphatidylinositol 3-kinase requires the serine-threonine kinase Akt/protein kinase B. (5/2643)

The oncogene p3k, coding for a constitutively active form of phosphatidylinositol 3-kinase (PI 3-kinase), strongly activates myogenic differentiation. Inhibition of endogenous PI 3-kinase activity with the specific inhibitor LY294002, or with dominant-negative mutants of PI 3-kinase, interferes with myotube formation and with the expression of muscle-specific proteins. Here we demonstrate that a downstream target of PI 3-kinase, serine-threonine kinase Akt, plays an important role in myogenic differentiation. Expression of constitutively active forms of Akt dramatically enhances myotube formation and expression of the muscle-specific proteins MyoD, creatine kinase, myosin heavy chain, and desmin. Transdominant negative forms of Akt inhibit myotube formation and the expression of muscle-specific proteins. The inhibition of myotube formation and the reduced expression of muscle-specific proteins caused by the PI 3-kinase inhibitor LY294002 are completely reversed by constitutively active forms of Akt. Wild-type cellular Akt effects a partial reversal of LY294002-induced inhibition of myogenic differentiation. This result suggests that Akt can substitute for PI 3-kinase in the stimulation of myogenesis; Akt may be an essential downstream component of PI 3-kinase-induced muscle differentiation.  (+info)

Coexistence of mitochondrial DNA and beta myosin heavy chain mutations in hypertrophic cardiomyopathy with late congestive heart failure. (6/2643)

OBJECTIVE: To investigate the possible coexistence of mitochondrial DNA (mtDNA) mutations in patients with beta myosin heavy chain (beta MHC) linked hypertrophic cardiomyopathy (HCM) who develop congestive heart failure. DESIGN: Molecular analysis of beta MHC and mtDNA gene defects in patients with HCM. SETTING: Cardiovascular molecular diagnostic and heart transplantation reference centre in north Italy. PATIENTS: Four patients with HCM who underwent heart transplantation for end stage heart failure, and after pedigree analysis of 60 relatives, eight additional affected patients and 27 unaffected relatives. A total of 111 unrelated healthy adult volunteers served as controls. Disease controls included an additional 27 patients with HCM and 102 with dilated cardiomyopathy. INTERVENTION: Molecular analysis of DNA from myocardial and skeletal muscle tissue and from peripheral blood specimens. MAIN OUTCOME MEASURES: Screening for mutations in beta MHC (exons 3-23) and mtDNA tRNA (n = 22) genes with denaturing gradient gel electrophoresis or single strand conformational polymorphism followed by automated DNA sequencing. RESULTS: One proband (kindred A) (plus seven affected relatives) had arginine 249 glutamine (Arg249Gln) beta MHC and heteroplasmic mtDNA tRNAIle A4300G mutations. Another unrelated patient (kindred B) with sporadic HCM had identical mutations. The remaining two patients (kindred C), a mother and son, had a novel beta MHC mutation (lysine 450 glutamic acid) (Lys450Glu) and a heteroplasmic missense (T9957C, phenylalanine (Phe)-->leucine (Leu)) mtDNA mutation in subunit III of the cytochrome C oxidase gene. The amount of mutant mtDNA was higher in the myocardium than in skeletal muscle or peripheral blood and in affected patients than in asymptomatic relatives. Mutations were absent in the controls. Pathological and biochemical characteristics of patients with mutations Arg249Gln plus A4300G (kindreds A and B) were identical, but different from those of the two patients with Lys450Glu plus T9957C(Phe-->Leu) mutations (kindred C). Cytochrome C oxidase activity and histoenzymatic staining were severely decreased in the two patients in kindreds A and B, but were unaffected in the two in kindred C. CONCLUSIONS: beta MHC gene and mtDNA mutations may coexist in patients with HCM and end stage congestive heart failure. Although beta MHC gene mutations seem to be the true determinants of HCM, both mtDNA mutations in these patients have known prerequisites for pathogenicity. Coexistence of other genetic abnormalities in beta MHC linked HCM, such as mtDNA mutations, may contribute to variable phenotypic expression and explain the heterogeneous behaviour of HCM.  (+info)

Altered crossbridge kinetics in the alphaMHC403/+ mouse model of familial hypertrophic cardiomyopathy. (7/2643)

A mutation in the cardiac beta-myosin heavy chain, Arg403Gln (R403Q), causes a severe form of familial hypertrophic cardiomyopathy (FHC) in humans. We used small-amplitude (0.25%) length-perturbation analysis to examine the mechanical properties of skinned left ventricular papillary muscle strips from mouse hearts bearing the R403Q mutation in the alpha-myosin heavy chain (alphaMHC403/+). Myofibrillar disarray with variable penetrance occurred in the left ventricular free wall of the alphaMHC403/+ hearts. In resting strips (pCa 8), dynamic stiffness was approximately 40% greater than in wild-type strips, consistent with elevated diastolic stiffness reported for murine hearts with FHC. At pCa 6 (submaximal activation), strip isometric tension was approximately 3 times higher than for wild-type strips, whereas at pCa 5 (maximal activation), tension was marginally lower. At submaximal calcium activation the characteristic frequencies of the work-producing (b) and work-absorbing (c) steps of the crossbridge were less in alphaMHC403/+ strips than in wild-type strips (b=11+/-1 versus 15+/-1 Hz; c= 58+/-3 versus 66+/-3 Hz; 27 degrees C). At maximal calcium activation, strip oscillatory power was reduced (0. 53+/-0.25 versus 1.03+/-0.18 mW/mm3; 27 degrees C), which is partly attributable to the reduced frequency b, at which crossbridge work is maximum. The results are consistent with the hypothesis that the R403Q mutation reduces the strong binding affinity of myosin for actin. Myosin heads may accumulate in a preforce state that promotes cooperative activation of the thin filament at submaximal calcium but blunts maximal tension and oscillatory power output at maximal calcium. The calcium-dependent effect of the mutation (whether facilitating or debilitating), together with a variable degree of fibrosis and myofibrillar disorder, may contribute to the diversity of clinical symptoms observed in murine FHC.  (+info)

Age-related changes in contractile properties of single skeletal fibers from the soleus muscle. (8/2643)

Peak absolute force, specific tension (peak absolute force per cross-sectional area), cross-sectional area, maximal unloaded shortening velocity (Vo; determined by the slack test), and myosin heavy chain (MHC) isoform compositions were determined in 124 single skeletal fibers from the soleus muscle of 12-, 24-, 30-, 36-, and 37-mo-old Fischer 344 Brown Norway F1 Hybrid rats. All fibers expressed the type I MHC isoform. The mean Vo remained unchanged from 12 to 24 mo but did decrease significantly from the 24- to 30-mo time period (from 1.71 +/- 0.13 to 0.85 +/- 0.09 fiber lengths/s). Fiber cross-sectional area remained constant until 36 mo of age, at which time there was a 20% decrease from the values at 12 mo of age (from 5,558 +/- 232 to 4,339 +/- 280 micrometer2). A significant decrease in peak absolute force of single fibers occurred between 12 and 24 mo of age (from 51 +/- 2 x 10(-5) to 35 +/- 2 x 10(-5) N) and then remained constant until 36 mo, when another 43% decrease occurred. Like peak absolute force, the specific tension decreased significantly between 12 and 24 mo by 20%, and another 32% decline was observed at 37 mo. Thus, by 24 mo, there was a dissociation between the loss of fiber cross-sectional area and force. The results suggest time-specific changes of the contractile properties with aging that are independent of each other. Underlying mechanisms responsible for the time-dependent and contractile property-specific changes are unknown. Age-related changes in the molecular dynamics of myosin may be the underlying mechanism for altered force production. The presence of more than one beta/slow MHC isoform may be the mechanism for the altered Vo with age.  (+info)

Myosin Heavy Chains are the large, essential components of myosin molecules, which are responsible for the molecular motility in muscle cells. These heavy chains have a molecular weight of approximately 200 kDa and form the motor domain of myosin, which binds to actin filaments and hydrolyzes ATP to generate force and movement during muscle contraction. There are several different types of myosin heavy chains, each with specific roles in various tissues and cellular functions. In skeletal and cardiac muscles, for example, myosin heavy chains have distinct isoforms that contribute to the contractile properties of these tissues.

Myosins are a large family of motor proteins that play a crucial role in various cellular processes, including muscle contraction and intracellular transport. They consist of heavy chains, which contain the motor domain responsible for generating force and motion, and light chains, which regulate the activity of the myosin. Based on their structural and functional differences, myosins are classified into over 35 classes, with classes II, V, and VI being the most well-studied.

Class II myosins, also known as conventional myosins, are responsible for muscle contraction in skeletal, cardiac, and smooth muscles. They form filaments called thick filaments, which interact with actin filaments to generate force and movement during muscle contraction.

Class V myosins, also known as unconventional myosins, are involved in intracellular transport and organelle positioning. They have a long tail that can bind to various cargoes, such as vesicles, mitochondria, and nuclei, and a motor domain that moves along actin filaments to transport the cargoes to their destinations.

Class VI myosins are also unconventional myosins involved in intracellular transport and organelle positioning. They have two heads connected by a coiled-coil tail, which can bind to various cargoes. Class VI myosins move along actin filaments in a unique hand-over-hand motion, allowing them to transport their cargoes efficiently.

Overall, myosins are essential for many cellular functions and have been implicated in various diseases, including cardiovascular diseases, neurological disorders, and cancer.

Myosin subfragments refer to the smaller components that result from the dissociation or proteolytic digestion of myosin, a motor protein involved in muscle contraction. The two main subfragments are called S1 and S2.

S1 is the "head" of the myosin molecule, which contains the actin-binding site, ATPase activity, and the ability to generate force and motion during muscle contraction. It has a molecular weight of approximately 120 kDa.

S2 is the "tail" of the myosin molecule, which has a molecular weight of about 350 kDa and is responsible for forming the backbone of the thick filament in muscle sarcomeres. S2 can be further divided into light meromyosin (LMM) and heavy meromyosin (HMM). HMM consists of S1 and part of S2, while LMM comprises the remaining portion of S2.

These subfragments are essential for understanding myosin's structure, function, and interactions with other muscle components at a molecular level.

Myosin Type II, also known as myosin II or heavy meromyosin, is a type of motor protein involved in muscle contraction and other cellular movements. It is a hexameric protein composed of two heavy chains and four light chains. The heavy chains have a head domain that binds to actin filaments and an tail domain that forms a coiled-coil structure, allowing the formation of filaments. Myosin II uses the energy from ATP hydrolysis to move along actin filaments, generating force and causing muscle contraction or other cell movements. It plays a crucial role in various cellular processes such as cytokinesis, cell motility, and maintenance of cell shape.

Myosin light chains are regulatory proteins that bind to the myosin head region of myosin molecules, which are involved in muscle contraction. There are two types of myosin light chains, essential and regulatory, that have different functions. The essential light chains are necessary for the assembly and stability of the myosin filaments, while the regulatory light chains control the calcium-sensitive activation of the myosin ATPase activity during muscle contraction. Phosphorylation of the regulatory light chains plays a critical role in regulating muscle contraction and relaxation.

Immunoglobulin heavy chains are proteins that make up the framework of antibodies, which are Y-shaped immune proteins. These heavy chains, along with light chains, form the antigen-binding sites of an antibody, which recognize and bind to specific foreign substances (antigens) in order to neutralize or remove them from the body.

The heavy chain is composed of a variable region, which contains the antigen-binding site, and constant regions that determine the class and function of the antibody. There are five classes of immunoglobulins (IgA, IgD, IgE, IgG, and IgM) that differ in their heavy chain constant regions and therefore have different functions in the immune response.

Immunoglobulin heavy chains are synthesized by B cells, a type of white blood cell involved in the adaptive immune response. The genetic rearrangement of immunoglobulin heavy chain genes during B cell development results in the production of a vast array of different antibodies with unique antigen-binding sites, allowing for the recognition and elimination of a wide variety of pathogens.

Nonmuscle Myosin Type IIB (NMMIIB) is a type of motor protein that belongs to the myosin superfamily. It is involved in various cellular processes, including cell division, adhesion, migration, and maintenance of cell shape. NMMIIB is composed of two heavy chains, two regulatory light chains, and two essential light chains. The heavy chains have a motor domain that enables the protein to move along actin filaments, generating force and movement.

NMMIIB is widely expressed in non-muscle tissues, and its activity is regulated by phosphorylation and dephosphorylation of the regulatory light chains. Phosphorylation activates NMMIIB, leading to contractile forces that can alter cell shape and promote cell motility. In contrast, dephosphorylation inactivates NMMIIB, allowing for relaxation of the contractile forces.

Abnormal regulation of NMMIIB has been implicated in various pathological conditions, including cancer metastasis, cardiovascular diseases, and neurological disorders. Therefore, understanding the molecular mechanisms that regulate NMMIIB function is an important area of research with potential therapeutic implications.

Nonmuscle Myosin Type IIA (NMIIA) is a type of non-muscle myosin protein that belongs to the myosin II family. These motor proteins are responsible for generating contractile forces in non-muscle cells, which allows them to change shape and move. NMIIA is widely expressed in various tissues and plays crucial roles in numerous cellular processes, including cytokinesis (cell division), maintenance of cell shape, and intracellular transport.

NMIIA consists of two heavy chains, two regulatory light chains, and two essential light chains. The heavy chains have a motor domain that binds to actin filaments and hydrolyzes ATP to generate force for movement along the actin filament. The regulatory and essential light chains regulate the activity and assembly of NMIIA.

Mutations in the gene encoding NMIIA (MYH9) have been associated with several human genetic disorders, such as May-Hegglin anomaly, Fechtner syndrome, and Delletten-Patterson syndrome, which are characterized by thrombocytopenia, bleeding disorders, and hearing loss.

Myosin Type V is an molecular motor protein involved in the intracellular transport of various cargoes, including vesicles and organelles. It belongs to the family of myosins, which are actin-based motors that convert chemical energy into mechanical work through the hydrolysis of ATP.

Myosin V is characterized by its long tail domain, which allows it to form dimers or higher-order oligomers, and its head domain, which binds to actin filaments and hydrolyzes ATP to generate force and movement. The protein moves in a hand-over-hand manner along the actin filament, allowing it to transport cargoes over long distances within the cell.

Myosin V has been implicated in various cellular processes, including exocytosis, endocytosis, and organelle positioning. Mutations in the MYO5A gene, which encodes Myosin Type V, have been associated with several human genetic disorders, such as Griscelli syndrome type 1 and familial progressive arthro-ophthalmopathy.

Ventricular myosins are the type of myosin proteins that are primarily found in the cardiac muscle cells (cardiomyocytes) of the heart ventricles. These myosin filaments are responsible for generating the mechanical force needed for cardiac muscle contraction and relaxation, which is essential for pumping blood throughout the body.

More specifically, ventricular myosins are part of the sarcomere structure in cardiomyocytes, where they interact with actin filaments to form cross-bridges during muscle contraction. The formation and breaking of these cross-bridges result in the sliding of actin and myosin filaments relative to each other, leading to muscle shortening and force generation.

Mutations or dysfunction in ventricular myosins can lead to various cardiac diseases, including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and heart failure. Therefore, understanding the structure and function of ventricular myosins is crucial for developing new therapeutic strategies to treat these conditions.

Cardiac myosins are a type of myosin protein that are specifically expressed in the cardiac muscle cells (or cardiomyocytes) of the heart. These proteins play a crucial role in the contraction and relaxation of heart muscles, which is essential for proper heart function and blood circulation.

Myosins are molecular motors that use chemical energy from ATP to generate force and movement. In the context of cardiac muscle cells, cardiac myosins interact with another protein called actin to form sarcomeres, which are the basic contractile units of muscle fibers. During contraction, the heads of cardiac myosin molecules bind to actin filaments and pull them together, causing the muscle fiber to shorten and generate force.

There are different isoforms of cardiac myosins that can vary in their structure and function. Mutations in the genes encoding these proteins have been linked to various forms of cardiomyopathy, which are diseases of the heart muscle that can lead to heart failure and other complications. Therefore, understanding the structure and function of cardiac myosins is an important area of research for developing therapies and treatments for heart disease.

Slow-twitch muscle fibers, also known as type I muscle fibers, are specialized skeletal muscle cells that contract relatively slowly and generate less force than fast-twitch fibers. However, they can maintain contraction for longer periods of time and have a higher resistance to fatigue. These fibers primarily use oxygen and aerobic metabolism to produce energy, making them highly efficient during prolonged, lower-intensity activities such as long-distance running or cycling. Slow-twitch muscle fibers also have an abundant blood supply, which allows for efficient delivery of oxygen and removal of waste products.

A muscle is a soft tissue in our body that contracts to produce force and motion. It is composed mainly of specialized cells called muscle fibers, which are bound together by connective tissue. There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac. Skeletal muscles attach to bones and help in movement, while smooth muscles are found within the walls of organs and blood vessels, helping with functions like digestion and circulation. Cardiac muscle is the specific type that makes up the heart, allowing it to pump blood throughout the body.

Fast-twitch muscle fibers, also known as type II fibers, are a type of skeletal muscle fiber that are characterized by their rapid contraction and relaxation rates. These fibers have a larger diameter and contain a higher concentration of glycogen, which serves as a quick source of energy for muscle contractions. Fast-twitch fibers are further divided into two subcategories: type IIa and type IIb (or type IIx). Type IIa fibers have a moderate amount of mitochondria and can utilize both aerobic and anaerobic metabolic pathways, making them fatigue-resistant. Type IIb fibers, on the other hand, have fewer mitochondria and primarily use anaerobic metabolism, leading to faster fatigue. Fast-twitch fibers are typically used in activities that require quick, powerful movements such as sprinting or weightlifting.

Skeletal muscle, also known as striated or voluntary muscle, is a type of muscle that is attached to bones by tendons or aponeuroses and functions to produce movements and support the posture of the body. It is composed of long, multinucleated fibers that are arranged in parallel bundles and are characterized by alternating light and dark bands, giving them a striped appearance under a microscope. Skeletal muscle is under voluntary control, meaning that it is consciously activated through signals from the nervous system. It is responsible for activities such as walking, running, jumping, and lifting objects.

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.

Smooth muscle myosin is a type of motor protein that is responsible for the contraction and relaxation of smooth muscles, which are found in various organs such as the bladder, blood vessels, and digestive tract. Smooth muscle myosin is composed of two heavy chains and four light chains, forming a hexameric structure. The heavy chains have an N-terminal head domain that contains the ATPase activity and a C-terminal tail domain that mediates filament assembly.

The smooth muscle myosin molecule has several unique features compared to other types of myosins, such as skeletal or cardiac myosin. For example, smooth muscle myosin has a longer lever arm, which allows for greater force generation during contraction. Additionally, the regulatory mechanism of smooth muscle myosin is different from that of skeletal or cardiac myosin. In smooth muscles, the contractile activity is regulated by phosphorylation of the light chains, which is mediated by a specific kinase called myosin light chain kinase (MLCK).

Overall, the proper regulation and function of smooth muscle myosin are critical for maintaining normal physiological functions in various organs. Dysregulation or mutations in smooth muscle myosin can lead to several diseases, such as hypertension, atherosclerosis, and gastrointestinal motility disorders.

Myosin Type I, also known as myosin-IA, is a type of motor protein found in non-muscle cells. It is involved in various cellular processes such as organelle transport, cell division, and maintenance of cell shape. Myosin-IA consists of a heavy chain, light chains, and a cargo-binding tail domain. The heavy chain contains the motor domain that binds to actin filaments and hydrolyzes ATP to generate force and movement along the actin filament.

Myosin-I is unique among myosins because it can move in both directions along the actin filament, whereas most other myosins can only move in one direction. Additionally, myosin-I has a high duty ratio, meaning that it spends a larger proportion of its ATP hydrolysis cycle bound to the actin filament, making it well-suited for processes requiring sustained force generation or precise positioning.

Skeletal muscle fibers, also known as striated muscle fibers, are the type of muscle cells that make up skeletal muscles, which are responsible for voluntary movements of the body. These muscle fibers are long, cylindrical, and multinucleated, meaning they contain multiple nuclei. They are surrounded by a connective tissue layer called the endomysium, and many fibers are bundled together into fascicles, which are then surrounded by another layer of connective tissue called the perimysium.

Skeletal muscle fibers are composed of myofibrils, which are long, thread-like structures that run the length of the fiber. Myofibrils contain repeating units called sarcomeres, which are responsible for the striated appearance of skeletal muscle fibers. Sarcomeres are composed of thick and thin filaments, which slide past each other during muscle contraction to shorten the sarcomere and generate force.

Skeletal muscle fibers can be further classified into two main types based on their contractile properties: slow-twitch (type I) and fast-twitch (type II). Slow-twitch fibers have a high endurance capacity and are used for sustained, low-intensity activities such as maintaining posture. Fast-twitch fibers, on the other hand, have a higher contractile speed and force generation capacity but fatigue more quickly and are used for powerful, explosive movements.

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

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.

Muscle development, also known as muscle hypertrophy, refers to the increase in size and mass of the muscles through a process called myofiber growth. This is primarily achieved through resistance or strength training exercises that cause micro-tears in the muscle fibers, leading to an inflammatory response and the release of hormones that promote muscle growth. As the muscles repair themselves, they become larger and stronger than before. Proper nutrition, including adequate protein intake, and rest are also essential components of muscle development.

It is important to note that while muscle development can lead to an increase in strength and muscular endurance, it does not necessarily result in improved athletic performance or overall fitness. A well-rounded exercise program that includes cardiovascular activity, flexibility training, and resistance exercises is recommended for optimal health and fitness outcomes.

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.

Skeletal muscle myosin, also known as myosin II, is a type of motor protein that plays a crucial role in muscle contraction. It is a hexameric protein composed of two heavy chains and four light chains. The heavy chains have a head region, which contains the ATPase activity and binds to actin filaments, and a tail region, which forms a coiled-coil structure that allows myosin molecules to self-associate into thick filaments.

During muscle contraction, the myosin heads bind to actin filaments in the sarcomere and undergo a power stroke, which results in the sliding of the actin filaments relative to the myosin filaments and thus shortening of the sarcomere. The ATP hydrolysis provides the energy for this power stroke.

Skeletal muscle myosin is essential for generating force and movement in skeletal muscles, and its dysfunction can lead to various muscle diseases and disorders.

Myofibrils are the basic contractile units of muscle fibers, composed of highly organized arrays of thick and thin filaments. They are responsible for generating the force necessary for muscle contraction. The thick filaments are primarily made up of the protein myosin, while the thin filaments are mainly composed of actin. Myofibrils are surrounded by a membrane called the sarcolemma and are organized into repeating sections called sarcomeres, which are the functional units of muscle contraction.

Clathrin Heavy Chains are the major structural components of clathrin coated vesicles, which are involved in intracellular trafficking and transport of proteins and lipids between different cellular compartments. These chains combine with light chains to form triskelions, a three-legged structure that polymerizes to form a cage-like lattice surrounding the vesicle membrane during the process of vesicle formation. The heavy chains are large polypeptides with a molecular weight of approximately 190 kDa and are subject to post-translational modifications such as phosphorylation, which can regulate their function in clathrin-mediated endocytosis.

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.

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.

Actomyosin is a contractile protein complex that consists of actin and myosin filaments. It plays an essential role in muscle contraction, cell motility, and cytokinesis (the process of cell division where the cytoplasm is divided into two daughter cells). The interaction between actin and myosin generates force and movement through a mechanism called sliding filament theory. In this process, myosin heads bind to actin filaments and then undergo a power stroke, which results in the sliding of one filament relative to the other and ultimately leads to muscle contraction or cellular movements. Actomyosin complexes are also involved in various non-muscle cellular processes such as cytoplasmic streaming, intracellular transport, and maintenance of cell shape.

Myosin-Light-Chain Kinase (MLCK) is an enzyme that plays a crucial role in muscle contraction. It phosphorylates the regulatory light chains of myosin, a protein involved in muscle contraction, leading to the activation of myosin and the initiation of the contractile process. MLCK is activated by calcium ions and calmodulin, and its activity is essential for various cellular processes, including cytokinesis, cell motility, and maintenance of cell shape. In addition to its role in muscle contraction, MLCK has been implicated in several pathological conditions, such as hypertension, atherosclerosis, and cancer.

Heavy Chain Disease (HCD) is a rare and serious condition related to B-cell disorders, where the immunoglobulin molecules produced by the immune system are defective. Normally, an immunoglobulin molecule consists of two heavy chains and two light chains. However, in Heavy Chain Disease, the immunoglobulins lack light chains and have only one or two heavy chains. This leads to the production of abnormal antibodies that can cause damage to various organs, particularly the spleen, lymph nodes, and bone marrow.

There are three types of Heavy Chain Disease: Alpha (α), Gamma (γ), and Mu (μ) HCD, each named after the type of heavy chain involved. The most common form is Alpha-HCD, which primarily affects children and young adults in Mediterranean countries and is often associated with an underlying immune deficiency disorder. Gamma-HCD and Mu-HCD are rarer and typically occur in older adults without any known immune deficiency.

Heavy Chain Disease can be challenging to diagnose due to its rarity and nonspecific symptoms, which may include fatigue, weight loss, frequent infections, anemia, and enlarged lymph nodes or spleen. Diagnosis usually involves a combination of clinical evaluation, laboratory tests, imaging studies, and sometimes bone marrow biopsy. Treatment options depend on the type and severity of HCD and may include chemotherapy, immunotherapy, targeted therapy, or stem cell transplantation.

Muscle proteins are a type of protein that are found in muscle tissue and are responsible for providing structure, strength, and functionality to muscles. The two major types of muscle proteins are:

1. Contractile proteins: These include actin and myosin, which are responsible for the contraction and relaxation of muscles. They work together to cause muscle movement by sliding along each other and shortening the muscle fibers.
2. Structural proteins: These include titin, nebulin, and desmin, which provide structural support and stability to muscle fibers. Titin is the largest protein in the human body and acts as a molecular spring that helps maintain the integrity of the sarcomere (the basic unit of muscle contraction). Nebulin helps regulate the length of the sarcomere, while desmin forms a network of filaments that connects adjacent muscle fibers together.

Overall, muscle proteins play a critical role in maintaining muscle health and function, and their dysregulation can lead to various muscle-related disorders such as muscular dystrophy, myopathies, and sarcopenia.

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 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.

Muscle contraction is the physiological process in which muscle fibers shorten and generate force, leading to movement or stability of a body part. This process involves the sliding filament theory where thick and thin filaments within the sarcomeres (the functional units of muscles) slide past each other, facilitated by the interaction between myosin heads and actin filaments. The energy required for this action is provided by the hydrolysis of adenosine triphosphate (ATP). Muscle contractions can be voluntary or involuntary, and they play a crucial role in various bodily functions such as locomotion, circulation, respiration, and posture maintenance.

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

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

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

Molecular motor proteins are a type of protein that convert chemical energy into mechanical work at the molecular level. They play a crucial role in various cellular processes, such as cell division, muscle contraction, and intracellular transport. There are several types of molecular motor proteins, including myosin, kinesin, and dynein.

Myosin is responsible for muscle contraction and movement along actin filaments in the cytoplasm. Kinesin and dynein are involved in intracellular transport along microtubules, moving cargo such as vesicles, organelles, and mRNA to various destinations within the cell.

These motor proteins move in a stepwise fashion, with each step driven by the hydrolysis of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate (Pi). The directionality and speed of movement are determined by the structure and regulation of the motor proteins, as well as the properties of the tracks along which they move.

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.

"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.

Adenosine triphosphatases (ATPases) are a group of enzymes that catalyze the conversion of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate. This reaction releases energy, which is used to drive various cellular processes such as muscle contraction, transport of ions across membranes, and synthesis of proteins and nucleic acids.

ATPases are classified into several types based on their structure, function, and mechanism of action. Some examples include:

1. P-type ATPases: These ATPases form a phosphorylated intermediate during the reaction cycle and are involved in the transport of ions across membranes, such as the sodium-potassium pump and calcium pumps.
2. F-type ATPases: These ATPases are found in mitochondria, chloroplasts, and bacteria, and are responsible for generating a proton gradient across the membrane, which is used to synthesize ATP.
3. V-type ATPases: These ATPases are found in vacuolar membranes and endomembranes, and are involved in acidification of intracellular compartments.
4. A-type ATPases: These ATPases are found in the plasma membrane and are involved in various functions such as cell signaling and ion transport.

Overall, ATPases play a crucial role in maintaining the energy balance of cells and regulating various physiological processes.

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

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

In human anatomy, a "gizzard" does not exist as it is not part of the human digestive system. However, in veterinary medicine, the gizzard refers to a part of the stomach in birds and some other animals, such as crocodiles and alligators. It is a muscular, thick-walled portion where food is stored and mechanically broken down by grinding and mixing it with grit that the animal has swallowed. This action helps in the digestion process, especially for birds that do not have teeth to chew their food.

A sarcomere is the basic contractile unit in a muscle fiber, and it's responsible for generating the force necessary for muscle contraction. It is composed of several proteins, including actin and myosin, which slide past each other to shorten the sarcomere during contraction. The sarcomere extends from one Z-line to the next in a muscle fiber, and it is delimited by the Z-discs where actin filaments are anchored. Sarcomeres play a crucial role in the functioning of skeletal, cardiac, and smooth muscles.

Smooth muscle, also known as involuntary muscle, is a type of muscle that is controlled by the autonomic nervous system and functions without conscious effort. These muscles are found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels, as well as in the eyes, skin, and other areas of the body.

Smooth muscle fibers are shorter and narrower than skeletal muscle fibers and do not have striations or sarcomeres, which give skeletal muscle its striped appearance. Smooth muscle is controlled by the autonomic nervous system through the release of neurotransmitters such as acetylcholine and norepinephrine, which bind to receptors on the smooth muscle cells and cause them to contract or relax.

Smooth muscle plays an important role in many physiological processes, including digestion, circulation, respiration, and elimination. It can also contribute to various medical conditions, such as hypertension, gastrointestinal disorders, and genitourinary dysfunction, when it becomes overactive or underactive.

'Gene rearrangement in B-lymphocytes, heavy chain' refers to the biological process that occurs during the development of B-lymphocytes (a type of white blood cell) in the bone marrow. This process involves the rearrangement of genetic material on chromosome 14, specifically within the immunoglobulin heavy chain gene locus.

During B-cell maturation, the variable region of the heavy chain gene is assembled from several gene segments, including the variable (V), diversity (D), and joining (J) segments. Through a series of genetic recombination events, these segments are randomly selected and joined together to form a unique V(D)J exon that encodes the variable region of the immunoglobulin heavy chain protein.

This gene rearrangement process allows for the generation of a diverse repertoire of antibodies with different specificities, enabling B-lymphocytes to recognize and respond to a wide range of foreign antigens. However, if errors occur during this process, it can lead to the production of autoantibodies that target the body's own cells and tissues, contributing to the development of certain immune disorders such as autoimmune diseases.

Atrial myosins refer to the protein filaments in the muscle cells (myocytes) of the heart's upper chambers, the atria. These myosin filaments are a crucial component of the sarcomeres, which are the basic contractile units of muscle fibers. They play a vital role in generating the force necessary for atrial contraction and pumping blood into the lower chambers of the heart (the ventricles).

Myosins consist of two major components: heavy chains and light chains. The heavy chains have a head region that binds to actin filaments, forming cross-bridges during muscle contraction, and a tail region that forms the backbone of the myosin filament. Light chains are regulatory proteins that modulate the activity of the myosin heads.

Atrial myosins have distinct structural and functional properties compared to ventricular myosins, which are found in the heart's lower chambers. These differences reflect the unique mechanical demands placed on atrial and ventricular muscle cells during the cardiac cycle. For example, atrial myosins generally have a higher ATPase activity than ventricular myosins, allowing for faster cross-bridge cycling and more rapid relaxation of the atria between contractions.

Understanding the properties and regulation of atrial myosins is essential for developing therapies to treat various cardiac diseases, such as atrial fibrillation and heart failure.

Immunoglobulin light chains are the smaller protein subunits of an immunoglobulin, also known as an antibody. They are composed of two polypeptide chains, called kappa (κ) and lambda (λ), which are produced by B cells during the immune response. Each immunoglobulin molecule contains either two kappa or two lambda light chains, in association with two heavy chains.

Light chains play a crucial role in the antigen-binding site of an antibody, where they contribute to the specificity and affinity of the interaction between the antibody and its target antigen. In addition to their role in immune function, abnormal production or accumulation of light chains can lead to various diseases, such as multiple myeloma and amyloidosis.

Tropomyosin is a protein that plays a crucial role in muscle contraction. It is a long, thin filamentous protein that runs along the length of actin filaments in muscle cells, forming part of the troponin-tropomyosin complex. This complex regulates the interaction between actin and myosin, which are the other two key proteins involved in muscle contraction.

In a relaxed muscle, tropomyosin blocks the myosin-binding sites on actin, preventing muscle contraction from occurring. When a signal is received to contract, calcium ions are released into the muscle cell, which binds to troponin and causes a conformational change that moves tropomyosin out of the way, exposing the myosin-binding sites on actin. This allows myosin to bind to actin and generate force, leading to muscle contraction.

Tropomyosin is composed of two alpha-helical chains that wind around each other in a coiled-coil structure. There are several isoforms of tropomyosin found in different types of muscle cells, including skeletal, cardiac, and smooth muscle. Mutations in the genes encoding tropomyosin have been associated with various inherited muscle disorders, such as hypertrophic cardiomyopathy and distal arthrogryposis.

Heterocyclic compounds with 4 or more rings refer to a class of organic compounds that contain at least four aromatic or non-aromatic rings in their structure, where one or more of the rings contains atoms other than carbon (heteroatoms) such as nitrogen, oxygen, sulfur, or selenium. These compounds are widely found in nature and have significant importance in medicinal chemistry due to their diverse biological activities. Many natural and synthetic drugs, pigments, vitamins, and antibiotics contain heterocyclic structures with four or more rings. The properties of these compounds depend on the size, shape, and nature of the rings, as well as the presence and position of functional groups.

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.

The actin cytoskeleton is a complex, dynamic network of filamentous (threadlike) proteins that provides structural support and shape to cells, allows for cell movement and division, and plays a role in intracellular transport. Actin filaments are composed of actin monomers that polymerize to form long, thin fibers. These filaments can be organized into different structures, such as stress fibers, which provide tension and support, or lamellipodia and filopodia, which are involved in cell motility. The actin cytoskeleton is constantly remodeling in response to various intracellular and extracellular signals, allowing for changes in cell shape and behavior.

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.

The masseter muscle is a strong chewing muscle in the jaw. It is a broad, thick, quadrilateral muscle that extends from the zygomatic arch (cheekbone) to the lower jaw (mandible). The masseter muscle has two distinct parts: the superficial part and the deep part.

The superficial part of the masseter muscle originates from the lower border of the zygomatic process of the maxilla and the anterior two-thirds of the inferior border of the zygomatic arch. The fibers of this part run almost vertically downward to insert on the lateral surface of the ramus of the mandible and the coronoid process.

The deep part of the masseter muscle originates from the deep surface of the zygomatic arch and inserts on the medial surface of the ramus of the mandible, blending with the temporalis tendon.

The primary function of the masseter muscle is to elevate the mandible, helping to close the mouth and clench the teeth together during mastication (chewing). It also plays a role in stabilizing the jaw during biting and speaking. The masseter muscle is one of the most powerful muscles in the human body relative to its size.

A diaphragm is a thin, dome-shaped muscle that separates the chest cavity from the abdominal cavity. It plays a vital role in the process of breathing as it contracts and flattens to draw air into the lungs (inhalation) and relaxes and returns to its domed shape to expel air out of the lungs (exhalation).

In addition, a diaphragm is also a type of barrier method of birth control. It is a flexible dome-shaped device made of silicone that fits over the cervix inside the vagina. When used correctly and consistently, it prevents sperm from entering the uterus and fertilizing an egg, thereby preventing pregnancy.

Isomerism is a term used in chemistry and biochemistry, including the field of medicine, to describe the existence of molecules that have the same molecular formula but different structural formulas. This means that although these isomers contain the same number and type of atoms, they differ in the arrangement of these atoms in space.

There are several types of isomerism, including constitutional isomerism (also known as structural isomerism) and stereoisomerism. Constitutional isomers have different arrangements of atoms, while stereoisomers have the same arrangement of atoms but differ in the spatial arrangement of their atoms in three-dimensional space.

Stereoisomerism can be further divided into subcategories such as enantiomers (mirror-image stereoisomers), diastereomers (non-mirror-image stereoisomers), and conformational isomers (stereoisomers that can interconvert by rotating around single bonds).

In the context of medicine, isomerism can be important because different isomers of a drug may have different pharmacological properties. For example, some drugs may exist as pairs of enantiomers, and one enantiomer may be responsible for the desired therapeutic effect while the other enantiomer may be inactive or even harmful. In such cases, it may be important to develop methods for producing pure enantiomers of the drug in order to maximize its efficacy and minimize its side effects.

"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.

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

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

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

'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.

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

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.

The Immunoglobulin (Ig) variable region is the antigen-binding part of an antibody, which is highly variable in its amino acid sequence and therefore specific to a particular epitope (the site on an antigen that is recognized by the antigen-binding site of an antibody). This variability is generated during the process of V(D)J recombination in the maturation of B cells, allowing for a diverse repertoire of antibodies to be produced and recognizing a wide range of potential pathogens.

The variable region is composed of several sub-regions including:

1. The heavy chain variable region (VH)
2. The light chain variable region (VL)
3. The heavy chain joining region (JH)
4. The light chain joining region (JL)

These regions are further divided into framework regions and complementarity-determining regions (CDRs). The CDRs, particularly CDR3, contain the most variability and are primarily responsible for antigen recognition.

Immunoglobulin G (IgG) gamma chains are the heavy, constant region proteins found in IgG immunoglobulins, which are a type of antibody. These gamma chains are composed of four subunits - two heavy chains and two light chains - and play a crucial role in the immune response by recognizing and binding to specific antigens, such as pathogens or foreign substances.

IgG is the most abundant type of antibody in human serum and provides long-term immunity against bacterial and viral infections. The gamma chains contain a region that binds to Fc receptors found on various immune cells, which facilitates the destruction of pathogens or foreign substances. Additionally, IgG can cross the placenta, providing passive immunity to the fetus.

Abnormalities in the production or function of IgG gamma chains can lead to various immunodeficiency disorders, such as X-linked agammaglobulinemia, which is characterized by a lack of functional B cells and low levels of IgG antibodies.

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.

Myosin III is a type of molecular motor protein found in cells, responsible for providing cellular movement and organization. More specifically, Myosin III is involved in the regulation of actin filament dynamics and contributes to various cellular functions such as vesicle transport, maintenance of cell shape, and signal transduction.

Myosin III has a unique motor domain that allows it to move along actin filaments while generating force. It also contains a protein kinase domain, which enables it to phosphorylate target proteins and regulate their activity. Mutations in the MYO3 gene have been associated with certain inherited diseases, such as Usher syndrome type 1F, a condition characterized by hearing loss and retinitis pigmentosa, leading to vision loss.

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.

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.

MyoD protein is a member of the family of muscle regulatory factors (MRFs) that play crucial roles in the development and regulation of skeletal muscle. MyoD is a transcription factor, which means it binds to specific DNA sequences and helps control the transcription of nearby genes into messenger RNA (mRNA).

MyoD protein is encoded by the MYOD1 gene and is primarily expressed in skeletal muscle cells, where it functions as a master regulator of muscle differentiation. During myogenesis, MyoD is activated and initiates the expression of various genes involved in muscle-specific functions, such as contractile proteins and ion channels.

MyoD protein can also induce cell cycle arrest and promote the differentiation of non-muscle cells into muscle cells, a process known as transdifferentiation. This property has been explored in regenerative medicine for potential therapeutic applications.

In summary, MyoD protein is a key regulator of skeletal muscle development, differentiation, and maintenance, and it plays essential roles in the regulation of gene expression during myogenesis.

Immunoglobulin heavy chains (IgH) are proteins that make up the framework of antibodies, which are crucial components of the adaptive immune system. These heavy chains are produced by B cells and plasma cells, and they contain variable regions that can bind to specific antigens, as well as constant regions that determine the effector functions of the antibody.

The genes that encode for immunoglobulin heavy chains are located on chromosome 14 in humans, within a region known as the IgH locus. These genes undergo a complex process of rearrangement during B cell development, whereby different gene segments (V, D, and J) are joined together to create a unique variable region that can recognize a specific antigen. This process of gene rearrangement is critical for the diversity and specificity of the antibody response.

Therefore, the medical definition of 'Genes, Immunoglobulin Heavy Chain' refers to the set of genetic elements that encode for the immunoglobulin heavy chain proteins, and their complex process of rearrangement during B cell development.

The oculomotor muscles are a group of extraocular muscles that control the movements of the eye. They include:

1. Superior rectus: This muscle is responsible for elevating the eye and helping with inward rotation (intorsion) when looking downwards.
2. Inferior rectus: It depresses the eye and helps with outward rotation (extorsion) when looking upwards.
3. Medial rectus: This muscle adducts, or moves, the eye towards the midline of the face.
4. Inferior oblique: The inferior oblique muscle intorts and elevates the eye.
5. Superior oblique: It extorts and depresses the eye.

These muscles work together to allow for smooth and precise movements of the eyes, enabling tasks such as tracking moving objects, reading, and maintaining visual fixation on a single point in space.

An Amoeba is a type of single-celled organism that belongs to the kingdom Protista. It's known for its ability to change shape and move through its environment using temporary extensions of cytoplasm called pseudopods. Amoebas are found in various aquatic and moist environments, and some species can even live as parasites within animals, including humans.

In a medical context, the term "Amoeba" often refers specifically to Entamoeba histolytica, a pathogenic species that can cause amoebiasis, a type of infectious disease. This parasite typically enters the human body through contaminated food or water and can lead to symptoms such as diarrhea, stomach pain, and weight loss. In severe cases, it may invade the intestinal wall and spread to other organs, causing potentially life-threatening complications.

It's important to note that while many species of amoebas exist in nature, only a few are known to cause human disease. Proper hygiene practices, such as washing hands thoroughly and avoiding contaminated food and water, can help prevent the spread of amoebic infections.

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.

Hindlimb suspension is a commonly used animal model in biomedical research, particularly in the study of muscle atrophy and disuse osteoporosis. In this model, the hindlimbs of rodents (such as rats or mice) are suspended using a tape or a harness system, which elevates their limbs off the ground and prevents them from bearing weight. This state of disuse leads to significant changes in the musculoskeletal system, including muscle atrophy, bone loss, and alterations in muscle fiber type composition and architecture.

The hindlimb suspension model is often used to investigate the mechanisms underlying muscle wasting and bone loss in conditions such as spinal cord injury, bed rest, and spaceflight-induced disuse. By understanding these mechanisms, researchers can develop potential therapeutic interventions to prevent or mitigate the negative effects of disuse on the musculoskeletal system.

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.

Dyneins are a type of motor protein that play an essential role in the movement of cellular components and structures within eukaryotic cells. They are responsible for generating force and motion along microtubules, which are critical components of the cell's cytoskeleton. Dyneins are involved in various cellular processes, including intracellular transport, organelle positioning, and cell division.

There are several types of dyneins, but the two main categories are cytoplasmic dyneins and axonemal dyneins. Cytoplasmic dyneins are responsible for moving various cargoes, such as vesicles, organelles, and mRNA complexes, toward the minus-end of microtubules, which is usually located near the cell center. Axonemal dyneins, on the other hand, are found in cilia and flagella and are responsible for their movement by sliding adjacent microtubules past each other.

Dyneins consist of multiple subunits, including heavy chains, intermediate chains, light-intermediate chains, and light chains. The heavy chains contain the motor domain that binds to microtubules and hydrolyzes ATP to generate force. Dysfunction in dynein proteins has been linked to various human diseases, such as neurodevelopmental disorders, ciliopathies, and cancer.

Immunoglobulin mu-chains (IgM) are a type of heavy chain found in immunoglobulins, also known as antibodies. IgM is the first antibody to be produced in response to an initial exposure to an antigen and plays a crucial role in the early stages of the immune response.

IgM antibodies are composed of four monomeric units, each consisting of two heavy chains and two light chains. The heavy chains in IgM are called mu-chains, which have a molecular weight of approximately 72 kDa. Each mu-chain contains five domains: one variable (V) domain at the N-terminus, four constant (C) domains (Cμ1-4), and a membrane-spanning region followed by a short cytoplasmic tail.

IgM antibodies are primarily found on the surface of B cells as part of the B cell receptor (BCR). When a B cell encounters an antigen, the BCR binds to it, triggering a series of intracellular signaling events that lead to B cell activation and differentiation into plasma cells. In response to activation, the B cell begins to secrete IgM antibodies into the bloodstream.

IgM antibodies have several unique features that make them effective in the early stages of an immune response. They are highly efficient at agglutination, or clumping together, of pathogens and antigens, which helps to neutralize them. IgM antibodies also activate the complement system, a group of proteins that work together to destroy pathogens.

Overall, Immunoglobulin mu-chains are an essential component of the immune system, providing early protection against pathogens and initiating the adaptive immune response.

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

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.

The laryngeal muscles are a group of skeletal muscles located in the larynx, also known as the voice box. These muscles play a crucial role in breathing, swallowing, and producing sounds for speech. They include:

1. Cricothyroid muscle: This muscle helps to tense the vocal cords and adjust their pitch during phonation (voice production). It is the only laryngeal muscle that is not innervated by the recurrent laryngeal nerve. Instead, it is supplied by the external branch of the superior laryngeal nerve.
2. Posterior cricoarytenoid muscle: This muscle is primarily responsible for abducting (opening) the vocal cords during breathing and speaking. It is the only muscle that can abduct the vocal cords.
3. Lateral cricoarytenoid muscle: This muscle adducts (closes) the vocal cords during phonation, swallowing, and coughing.
4. Transverse arytenoid muscle: This muscle also contributes to adduction of the vocal cords, working together with the lateral cricoarytenoid muscle. It also helps to relax and lengthen the vocal cords during quiet breathing.
5. Oblique arytenoid muscle: This muscle is involved in adducting, rotating, and shortening the vocal cords. It works together with the transverse arytenoid muscle to provide fine adjustments for voice production.
6. Thyroarytenoid muscle (Vocalis): This muscle forms the main body of the vocal cord and is responsible for its vibration during phonation. The vocalis portion of the muscle helps control pitch and tension in the vocal cords.

These muscles work together to enable various functions of the larynx, such as breathing, swallowing, and speaking.

Immunoglobulins (Igs), also known as antibodies, are proteins produced by the immune system to recognize and neutralize foreign substances such as pathogens or toxins. They are composed of four polypeptide chains: two heavy chains and two light chains, which are held together by disulfide bonds. The variable regions of the heavy and light chains contain loops that form the antigen-binding site, allowing each Ig molecule to recognize a specific epitope (antigenic determinant) on an antigen.

Genes encoding immunoglobulins are located on chromosome 14 (light chain genes) and chromosomes 22 and 2 (heavy chain genes). The diversity of the immune system is generated through a process called V(D)J recombination, where variable (V), diversity (D), and joining (J) gene segments are randomly selected and assembled to form the variable regions of the heavy and light chains. This results in an enormous number of possible combinations, allowing the immune system to recognize and respond to a vast array of potential threats.

There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, each with distinct functions and structures. For example, IgG is the most abundant class in serum and provides long-term protection against pathogens, while IgA is found on mucosal surfaces and helps prevent the entry of pathogens into the body.

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.

Myogenin is defined as a protein that belongs to the family of myogenic regulatory factors (MRFs). These proteins play crucial roles in the development, growth, and repair of skeletal muscle cells. Myogenin is specifically involved in the differentiation and fusion of myoblasts to form multinucleated myotubes, which are essential for the formation of mature skeletal muscle fibers. It functions as a transcription factor that binds to specific DNA sequences, thereby regulating the expression of genes required for muscle cell differentiation. Myogenin also plays a role in maintaining muscle homeostasis and may contribute to muscle regeneration following injury or disease.

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.

Myosin-Light-Chain Phosphatase (MLCP) is an enzyme complex that plays a crucial role in the regulation of muscle contraction and relaxation. It is responsible for dephosphorylating the myosin light chains, which are key regulatory components of the contractile apparatus in muscles.

The phosphorylation state of the myosin light chains regulates the interaction between actin and myosin filaments, which is necessary for muscle contraction. When the myosin light chains are phosphorylated, they bind more strongly to actin, leading to increased contractile force. Conversely, when the myosin light chains are dephosphorylated by MLCP, the interaction between actin and myosin is weakened, allowing for muscle relaxation.

MLCP is composed of three subunits: a catalytic subunit (PP1cδ), a regulatory subunit (MYPT1), and a small subunit (M20). The regulatory subunit contains binding sites for various signaling molecules that can modulate the activity of MLCP, such as calcium/calmodulin, protein kinase C, and Rho-associated protein kinase (ROCK). Dysregulation of MLCP has been implicated in various muscle disorders, including hypertrophic cardiomyopathy, dilated cardiomyopathy, and muscle atrophy.

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

A gene is a specific sequence of nucleotides in DNA that carries genetic information. Genes are the fundamental units of heredity and are responsible for the development and function of all living organisms. They code for proteins or RNA molecules, which carry out various functions within cells and are essential for the structure, function, and regulation of the body's tissues and organs.

Each gene has a specific location on a chromosome, and each person inherits two copies of every gene, one from each parent. Variations in the sequence of nucleotides in a gene can lead to differences in traits between individuals, including physical characteristics, susceptibility to disease, and responses to environmental factors.

Medical genetics is the study of genes and their role in health and disease. It involves understanding how genes contribute to the development and progression of various medical conditions, as well as identifying genetic risk factors and developing strategies for prevention, diagnosis, and treatment.

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.

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.

Muscular atrophy is a condition characterized by a decrease in the size and mass of muscles due to lack of use, disease, or injury. This occurs when there is a disruption in the balance between muscle protein synthesis and degradation, leading to a net loss of muscle proteins. There are two main types of muscular atrophy:

1. Disuse atrophy: This type of atrophy occurs when muscles are not used or are immobilized for an extended period, such as after an injury, surgery, or prolonged bed rest. In this case, the nerves that control the muscles may still be functioning properly, but the muscles themselves waste away due to lack of use.
2. Neurogenic atrophy: This type of atrophy is caused by damage to the nerves that supply the muscles, leading to muscle weakness and wasting. Conditions such as amyotrophic lateral sclerosis (ALS), spinal cord injuries, and peripheral neuropathies can cause neurogenic atrophy.

In both cases, the affected muscles may become weak, shrink in size, and lose their tone and mass. Treatment for muscular atrophy depends on the underlying cause and may include physical therapy, exercise, and medication to manage symptoms and improve muscle strength and function.

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.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

Myogenic regulatory factors (MRFs) are a group of transcription factors that play crucial roles in the development, growth, and maintenance of skeletal muscle cells. They are essential for the determination and differentiation of myoblasts into multinucleated myotubes and ultimately mature muscle fibers. The MRF family includes four key members: MyoD, Myf5, Mrf4 (also known as Myf6), and myogenin. These factors work together to regulate the expression of genes involved in various aspects of skeletal muscle formation and function.

1. MyoD: This MRF is a critical regulator of muscle cell differentiation and can induce non-muscle cells to adopt a muscle-like fate. It binds to specific DNA sequences, known as E-boxes, within the regulatory regions of target genes to activate or repress their transcription.
2. Myf5: Similar to MyoD, Myf5 is involved in the early determination and differentiation of myoblasts. However, it has a more restricted expression pattern during development compared to MyoD.
3. Mrf4 (Myf6): This MRF plays a role in both muscle cell differentiation and maintenance. It is expressed later than MyoD and Myf5 during development and helps regulate the terminal differentiation of myotubes into mature muscle fibers.
4. Myogenin: Among all MRFs, myogenin has the most specific function in muscle cell differentiation. It is required for the fusion of myoblasts to form multinucleated myotubes and is essential for the maturation and maintenance of skeletal muscle fibers.

In summary, Myogenic Regulatory Factors are a group of transcription factors that regulate skeletal muscle development, growth, and maintenance by controlling the expression of genes involved in various aspects of muscle cell differentiation and function.

Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.

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.

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.

Hypothyroidism is a medical condition where the thyroid gland, which is a small butterfly-shaped gland located in the front of your neck, does not produce enough thyroid hormones. This results in a slowing down of the body's metabolic processes, leading to various symptoms such as fatigue, weight gain, constipation, cold intolerance, dry skin, hair loss, muscle weakness, and depression.

The two main thyroid hormones produced by the thyroid gland are triiodothyronine (T3) and thyroxine (T4). These hormones play crucial roles in regulating various bodily functions, including heart rate, body temperature, and energy levels. In hypothyroidism, the production of these hormones is insufficient, leading to a range of symptoms that can affect multiple organ systems.

Hypothyroidism can be caused by several factors, including autoimmune disorders (such as Hashimoto's thyroiditis), surgical removal of the thyroid gland, radiation therapy for neck cancer, certain medications, and congenital defects. Hypothyroidism is typically diagnosed through blood tests that measure levels of TSH (thyroid-stimulating hormone), T3, and T4. Treatment usually involves taking synthetic thyroid hormones to replace the missing hormones and alleviate symptoms.

I'm not aware of any recognized medical term or condition specifically referred to as "turkeys." The term "turkey" is most commonly used in a non-medical context to refer to the large, bird-like domesticated fowl native to North America, scientifically known as Meleagris gallopavo.

However, if you are referring to a medical condition called "turkey neck," it is a colloquial term used to describe sagging or loose skin around the neck area, which can resemble a turkey's wattle. This condition is not a formal medical diagnosis but rather a descriptive term for an aesthetic concern some people may have about their appearance.

If you meant something else by "turkeys," please provide more context so I can give you a more accurate answer.

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.

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.

NADH-Tetrazolium Reductase, also known as NADH Dehydrogenase or Complex I, is an enzyme complex in the electron transport chain located within the inner mitochondrial membrane. It catalyzes the oxidation of nicotinamide adenine dinucleotide hydride (NADH) to nicotinamide adenine dinucleotide (NAD+), and the reduction of ubiquinone (CoQ) to ubiquinol. This reaction contributes to the production of ATP, which is the primary source of energy for cellular metabolism.

The enzyme complex consists of several subunits, including flavoproteins and iron-sulfur (Fe-S) clusters, which facilitate the transfer of electrons from NADH to CoQ. The reduction of CoQ leads to the formation of a proton gradient across the inner mitochondrial membrane, which drives the synthesis of ATP by ATP synthase.

NADH-Tetrazolium Reductase is also an important site for reactive oxygen species (ROS) production, particularly superoxide radicals, which can contribute to oxidative stress and cellular damage in certain pathological conditions.

Desmin is a type of intermediate filament protein that is primarily found in the cardiac and skeletal muscle cells, as well as in some types of smooth muscle cells. It is an important component of the cytoskeleton, which provides structural support to the cell and helps maintain its shape. Desmin plays a crucial role in maintaining the integrity of the sarcomere, which is the basic contractile unit of the muscle fiber. Mutations in the desmin gene can lead to various forms of muscular dystrophy and other inherited muscle disorders.

The cytoskeleton is a complex network of various protein filaments that provides structural support, shape, and stability to the cell. It plays a crucial role in maintaining cellular integrity, intracellular organization, and enabling cell movement. The cytoskeleton is composed of three major types of protein fibers: microfilaments (actin filaments), intermediate filaments, and microtubules. These filaments work together to provide mechanical support, participate in cell division, intracellular transport, and help maintain the cell's architecture. The dynamic nature of the cytoskeleton allows cells to adapt to changing environmental conditions and respond to various stimuli.

Hypertrophic cardiomyopathy (HCM) is a genetic disorder characterized by the thickening of the heart muscle, specifically the ventricles (the lower chambers of the heart that pump blood out to the body). This thickening can make it harder for the heart to pump blood effectively, which can lead to symptoms such as shortness of breath, chest pain, and fatigue. In some cases, HCM can also cause abnormal heart rhythms (arrhythmias) and may increase the risk of sudden cardiac death.

The thickening of the heart muscle in HCM is caused by an overgrowth of the cells that make up the heart muscle, known as cardiomyocytes. This overgrowth can be caused by mutations in any one of several genes that encode proteins involved in the structure and function of the heart muscle. These genetic mutations are usually inherited from a parent, but they can also occur spontaneously in an individual with no family history of the disorder.

HCM is typically diagnosed using echocardiography (a type of ultrasound that uses sound waves to create images of the heart) and other diagnostic tests such as electrocardiogram (ECG) and cardiac magnetic resonance imaging (MRI). Treatment for HCM may include medications to help manage symptoms, lifestyle modifications, and in some cases, surgical procedures or implantable devices to help prevent or treat arrhythmias.

Isometric contraction is a type of muscle activation where the muscle contracts without any change in the length of the muscle or movement at the joint. This occurs when the force generated by the muscle matches the external force opposing it, resulting in a balanced state with no visible movement. It is commonly experienced during activities such as holding a heavy object in static position or trying to push against an immovable object. Isometric contractions are important in maintaining posture and providing stability to joints.

Isoenzymes, also known as isoforms, are multiple forms of an enzyme that catalyze the same chemical reaction but differ in their amino acid sequence, structure, and/or kinetic properties. They are encoded by different genes or alternative splicing of the same gene. Isoenzymes can be found in various tissues and organs, and they play a crucial role in biological processes such as metabolism, detoxification, and cell signaling. Measurement of isoenzyme levels in body fluids (such as blood) can provide valuable diagnostic information for certain medical conditions, including tissue damage, inflammation, and various diseases.

Immunoglobulin constant regions are the invariant portions of antibody molecules (immunoglobulins) that are identical in all antibodies of the same isotype. These regions are responsible for effector functions such as complement activation, binding to Fc receptors, and initiating immune responses. They are composed of amino acid sequences that remain unchanged during antigen-driven somatic hypermutation, allowing them to interact with various components of the immune system. The constant regions are found in the heavy chains (CH) and light chains (CL) of an immunoglobulin molecule. In contrast, the variable regions are responsible for recognizing and binding to specific antigens.

A smooth muscle within the vascular system refers to the involuntary, innervated muscle that is found in the walls of blood vessels. These muscles are responsible for controlling the diameter of the blood vessels, which in turn regulates blood flow and blood pressure. They are called "smooth" muscles because their individual muscle cells do not have the striations, or cross-striped patterns, that are observed in skeletal and cardiac muscle cells. Smooth muscle in the vascular system is controlled by the autonomic nervous system and by hormones, and can contract or relax slowly over a period of time.

The heart ventricles are the two lower chambers of the heart that receive blood from the atria and pump it to the lungs or the rest of the body. The right ventricle pumps deoxygenated blood to the lungs, while the left ventricle pumps oxygenated blood to the rest of the body. Both ventricles have thick, muscular walls to generate the pressure necessary to pump blood through the circulatory system.

Chymotrypsin is a proteolytic enzyme, specifically a serine protease, that is produced in the pancreas and secreted into the small intestine as an inactive precursor called chymotrypsinogen. Once activated, chymotrypsin helps to digest proteins in food by breaking down specific peptide bonds in protein molecules. Its activity is based on the recognition of large hydrophobic side chains in amino acids like phenylalanine, tryptophan, and tyrosine. Chymotrypsin plays a crucial role in maintaining normal digestion and absorption processes in the human body.

Myoblasts are types of cells that are responsible for the development and growth of muscle tissue in the body. They are undifferentiated cells, meaning they have not yet developed into their final form or function. Myoblasts fuse together to form myotubes, which then develop into muscle fibers, also known as myofibers. This process is called myogenesis and it plays a crucial role in the growth, repair, and maintenance of skeletal muscle tissue throughout an individual's life.

Myoblasts can be derived from various sources, including embryonic stem cells, induced pluripotent stem cells, or satellite cells, which are adult stem cells found within mature muscle tissue. Satellite cells are typically quiescent but can be activated in response to muscle damage or injury, proliferate and differentiate into myoblasts, and fuse together to repair and replace damaged muscle fibers.

Dysregulation of myogenesis and impaired myoblast function have been implicated in various muscle-related disorders, including muscular dystrophies, sarcopenia, and cachexia. Therefore, understanding the biology of myoblasts and their role in muscle development and regeneration is an important area of research with potential therapeutic implications for muscle-related diseases.

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

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

Examples of recombinant fusion proteins include:

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

Connectin is also known as titin, which is a giant protein that plays a crucial role in the elasticity and stiffness of muscle fibers. It is the largest protein in humans, spanning half the length of a muscle cell's sarcomere, the basic unit of muscle contraction. Connectin/titin has several domains with different functions, including binding to other proteins, regulating muscle contraction, and signaling within the muscle cell. Mutations in the connectin/titin gene have been associated with various forms of muscular dystrophy and cardiomyopathy.

CD98 heavy chain is a type of protein found on the surface of many different types of cells in the human body. It is also known as SLCA1 or 4F2hc. The CD98 heavy chain combines with various other proteins to form transporter proteins, which are involved in the transport of various molecules across the cell membrane.

In the context of immunology and medical terminology, antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria that can be recognized by the immune system and stimulate an immune response. The CD98 heavy chain is not typically referred to as an antigen itself, but it may contribute to the overall antigenic properties of the cell expressing it.

However, it's important to note that the term "CD98 Heavy Chain" refers to a specific protein and not a medical condition or disease. If you have any specific concerns about this protein or its role in health and disease, I would recommend consulting with a healthcare professional or a researcher in the field of immunology.

Propylthiouracil is a medication that is primarily used to treat hyperthyroidism, a condition characterized by an overactive thyroid gland that produces too much thyroid hormone. The medication works by inhibiting the production of thyroid hormones in the body. It belongs to a class of drugs called antithyroid agents or thionamides.

In medical terms, propylthiouracil is defined as an antithyroid medication used to manage hyperthyroidism due to Graves' disease or toxic adenoma. It acts by inhibiting the synthesis of thyroid hormones, triiodothyronine (T3) and thyroxine (T4), in the thyroid gland. Propylthiouracil also reduces the peripheral conversion of T4 to T3. The medication is available as a tablet for oral administration and is typically prescribed at a starting dose of 100-150 mg three times daily, with adjustments made based on the patient's response and thyroid function tests.

It's important to note that propylthiouracil should be used under the close supervision of a healthcare provider due to potential side effects and risks associated with its use. Regular monitoring of thyroid function tests is necessary during treatment, and patients should promptly report any signs or symptoms of adverse reactions to their healthcare provider.

Muscle denervation is a medical term that refers to the loss of nerve supply to a muscle or group of muscles. This can occur due to various reasons, such as injury to the nerves, nerve compression, or certain medical conditions like neuromuscular disorders. When the nerve supply to the muscle is interrupted, it can lead to muscle weakness, atrophy (wasting), and ultimately, paralysis.

In denervation, the communication between the nervous system and the muscle is disrupted, which means that the muscle no longer receives signals from the brain to contract and move. Over time, this can result in significant muscle wasting and disability, depending on the severity and extent of the denervation.

Denervation may be treated with various therapies, including physical therapy, medication, or surgical intervention, such as nerve grafting or muscle transfers, to restore function and prevent further muscle wasting. The specific treatment approach will depend on the underlying cause and severity of the denervation.

Immunoglobulin alpha-chains (IgA) are a type of immunoglobulin or antibody that plays a crucial role in the immune system. They are composed of two heavy chains, known as alpha-chains, and two light chains. IgA is primarily found in secretions such as tears, saliva, breast milk, and respiratory and intestinal mucus, where they provide protection against pathogens that enter the body through these surfaces.

IgA can exist in two forms: a monomeric form, which consists of a single IgA molecule, and a polymeric form, which consists of several IgA molecules joined together by a J chain. The polymeric form is more common in secretions, where it provides an effective barrier against pathogens.

IgA functions by binding to antigens on the surface of pathogens, preventing them from attaching to and infecting host cells. It can also neutralize toxins produced by some bacteria and viruses. Additionally, IgA can activate the complement system, a group of proteins that work together to destroy pathogens, and initiate an immune response by recruiting other immune cells to the site of infection.

Deficiencies in IgA are relatively common and usually do not cause any significant health problems. However, in some cases, people with IgA deficiency may develop recurrent infections or allergies.

"Caenorhabditis" is a genus of nematode (roundworm) animals, which are commonly used as model organisms in scientific research. The most widely studied species within this genus is "Caenorhabditis elegans," which has been extensively researched due to its simple anatomy, short lifespan, and fully sequenced genome. These nematodes are found in various environments, including soil and decaying organic matter, and play a crucial role in the decomposition process. The term "Caenorhabditis" itself is derived from Greek roots, with "caeno" meaning "recent" or "new," and "rhabditis" referring to the shape of their tails.

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.

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

Muscular diseases, also known as myopathies, refer to a group of conditions that affect the functionality and health of muscle tissue. These diseases can be inherited or acquired and may result from inflammation, infection, injury, or degenerative processes. They can cause symptoms such as weakness, stiffness, cramping, spasms, wasting, and loss of muscle function.

Examples of muscular diseases include:

1. Duchenne Muscular Dystrophy (DMD): A genetic disorder that results in progressive muscle weakness and degeneration due to a lack of dystrophin protein.
2. Myasthenia Gravis: An autoimmune disease that causes muscle weakness and fatigue, typically affecting the eyes and face, throat, and limbs.
3. Inclusion Body Myositis (IBM): A progressive muscle disorder characterized by muscle inflammation and wasting, typically affecting older adults.
4. Polymyositis: An inflammatory myopathy that causes muscle weakness and inflammation throughout the body.
5. Metabolic Myopathies: A group of inherited disorders that affect muscle metabolism, leading to exercise intolerance, muscle weakness, and other symptoms.
6. Muscular Dystonias: Involuntary muscle contractions and spasms that can cause abnormal postures or movements.

It is important to note that muscular diseases can have a significant impact on an individual's quality of life, mobility, and overall health. Proper diagnosis and treatment are crucial for managing symptoms and improving outcomes.

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.

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

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

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

Sequence homology in nucleic acids refers to the similarity or identity between the nucleotide sequences of two or more DNA or RNA molecules. It is often used as a measure of biological relationship between genes, organisms, or populations. High sequence homology suggests a recent common ancestry or functional constraint, while low sequence homology may indicate a more distant relationship or different functions.

Nucleic acid sequence homology can be determined by various methods such as pairwise alignment, multiple sequence alignment, and statistical analysis. The degree of homology is typically expressed as a percentage of identical or similar nucleotides in a given window of comparison.

It's important to note that the interpretation of sequence homology depends on the biological context and the evolutionary distance between the sequences compared. Therefore, functional and experimental validation is often necessary to confirm the significance of sequence homology.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

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

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

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

Hypertrophic Cardiomyopathy, Familial is a genetic disorder characterized by thickening of the heart muscle (myocardium), specifically the ventricles. This thickening, or hypertrophy, can make it harder for the heart to pump blood effectively, potentially leading to symptoms such as shortness of breath, chest pain, and arrhythmias.

In familial hypertrophic cardiomyopathy, the disorder is inherited and passed down through families in an autosomal dominant pattern, meaning that a child has a 50% chance of inheriting the gene mutation from an affected parent. The condition can vary in severity even within the same family, and some individuals with the genetic mutation may not develop symptoms at all.

It is important to note that while hypertrophic cardiomyopathy can have serious consequences, many people with the condition lead normal lives with appropriate medical management and monitoring.

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.

Microfilament proteins are a type of structural protein that form part of the cytoskeleton in eukaryotic cells. They are made up of actin monomers, which polymerize to form long, thin filaments. These filaments are involved in various cellular processes such as muscle contraction, cell division, and cell motility. Microfilament proteins also interact with other cytoskeletal components like intermediate filaments and microtubules to maintain the overall shape and integrity of the cell. Additionally, they play a crucial role in the formation of cell-cell junctions and cell-matrix adhesions, which are essential for tissue structure and function.

Troponin is a protein complex found in cardiac and skeletal muscle cells that plays a critical role in muscle contraction. It consists of three subunits: troponin C, which binds calcium ions; troponin I, which inhibits the interaction between actin and myosin in the absence of calcium; and troponin T, which binds to tropomyosin and helps anchor the complex to the muscle filament.

In clinical medicine, "troponin" usually refers to cardiac-specific isoforms of these proteins (cTnI and cTnT) that are released into the bloodstream following damage to the heart muscle, such as occurs in myocardial infarction (heart attack). Measurement of troponin levels in the blood is a sensitive and specific biomarker for the diagnosis of acute myocardial infarction.

"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.

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

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.

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.

Acanthamoeba is a genus of free-living, ubiquitous amoebae found in various environments such as soil, water, and air. These microorganisms have a characteristic morphology with thin, flexible pseudopods and large, rounded cells that contain endospores. They are known to cause two major types of infections in humans: Acanthamoeba keratitis, an often painful and potentially sight-threatening eye infection affecting the cornea; and granulomatous amoebic encephalitis (GAE), a rare but severe central nervous system infection primarily impacting individuals with weakened immune systems.

Acanthamoeba keratitis typically occurs through contact lens wearers accidentally introducing the organism into their eyes, often via contaminated water sources or inadequately disinfected contact lenses and solutions. Symptoms include eye pain, redness, sensitivity to light, tearing, and blurred vision. Early diagnosis and treatment are crucial for preventing severe complications and potential blindness.

Granulomatous amoebic encephalitis is an opportunistic infection that affects people with compromised immune systems, such as those with HIV/AIDS, cancer, or organ transplant recipients. The infection spreads hematogenously (through the bloodstream) to the central nervous system, where it causes inflammation and damage to brain tissue. Symptoms include headache, fever, stiff neck, seizures, altered mental status, and focal neurological deficits. GAE is associated with high mortality rates due to its severity and the challenges in diagnosing and treating the infection effectively.

Prevention strategies for Acanthamoeba infections include maintaining good hygiene practices, regularly replacing contact lenses and storage cases, using sterile saline solution or disposable contact lenses, and avoiding swimming or showering while wearing contact lenses. Early detection and appropriate medical intervention are essential for managing these infections and improving patient outcomes.

Myocardial contraction refers to the rhythmic and forceful shortening of heart muscle cells (myocytes) in the myocardium, which is the muscular wall of the heart. This process is initiated by electrical signals generated by the sinoatrial node, causing a wave of depolarization that spreads throughout the heart.

During myocardial contraction, calcium ions flow into the myocytes, triggering the interaction between actin and myosin filaments, which are the contractile proteins in the muscle cells. This interaction causes the myofilaments to slide past each other, resulting in the shortening of the sarcomeres (the functional units of muscle contraction) and ultimately leading to the contraction of the heart muscle.

Myocardial contraction is essential for pumping blood throughout the body and maintaining adequate circulation to vital organs. Any impairment in myocardial contractility can lead to various cardiac disorders, such as heart failure, cardiomyopathy, and arrhythmias.

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

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

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

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

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

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

Calmodulin-binding proteins are a diverse group of proteins that have the ability to bind to calmodulin, a ubiquitous calcium-binding protein found in eukaryotic cells. Calmodulin plays a critical role in various cellular processes by regulating the activity of its target proteins in a calcium-dependent manner.

Calmodulin-binding proteins contain specific domains or motifs that enable them to interact with calmodulin. These domains can be classified into two main categories: IQ motifs and CaM motifs. The IQ motif is a short amino acid sequence that contains the consensus sequence IQXXXRGXXR, where X represents any amino acid. This motif binds to the C-lobe of calmodulin in a calcium-dependent manner. On the other hand, CaM motifs are longer sequences that can bind to both lobes of calmodulin with high affinity and in a calcium-dependent manner.

Calmodulin-binding proteins play crucial roles in various cellular functions, including signal transduction, gene regulation, cytoskeleton organization, and ion channel regulation. For example, calmodulin-binding proteins such as calcineurin and CaM kinases are involved in the regulation of immune responses, learning, and memory. Similarly, myosin regulatory light chains, which contain IQ motifs, play a critical role in muscle contraction by regulating the interaction between actin and myosin filaments.

In summary, calmodulin-binding proteins are a diverse group of proteins that interact with calmodulin to regulate various cellular processes. They contain specific domains or motifs that enable them to bind to calmodulin in a calcium-dependent manner, thereby modulating the activity of their target proteins.

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

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

"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.

Aging is a complex, progressive and inevitable process of bodily changes over time, characterized by the accumulation of cellular damage and degenerative changes that eventually lead to increased vulnerability to disease and death. It involves various biological, genetic, environmental, and lifestyle factors that contribute to the decline in physical and mental functions. The medical field studies aging through the discipline of gerontology, which aims to understand the underlying mechanisms of aging and develop interventions to promote healthy aging and extend the human healthspan.

Cardiomegaly is a medical term that refers to an enlarged heart. It can be caused by various conditions such as high blood pressure, heart valve problems, cardiomyopathy, or fluid accumulation around the heart (pericardial effusion). Cardiomegaly can be detected through imaging tests like chest X-rays or echocardiograms. Depending on the underlying cause, treatment options may include medications, lifestyle changes, or in some cases, surgery. It is important to consult with a healthcare professional for proper diagnosis and treatment.

Contractile proteins are a type of protein found in muscle cells that are responsible for the ability of the muscle to contract and generate force. The two main types of contractile proteins are actin and myosin, which are arranged in sarcomeres, the functional units of muscle fibers. When stimulated by a nerve impulse, actin and myosin filaments slide past each other, causing the muscle to shorten and generate force. This process is known as excitation-contraction coupling. Other proteins, such as tropomyosin and troponin, regulate the interaction between actin and myosin and control muscle contraction.

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

I'm sorry for any confusion, but "Protozoan Proteins" is not a specific medical or scientific term. Protozoa are single-celled eukaryotic organisms, and proteins are large biological molecules consisting of one or more chains of amino acid residues. Therefore, "Protozoan Proteins" generally refers to the various types of proteins found in protozoa.

However, if you're looking for information about proteins specific to certain protozoan parasites with medical relevance (such as Plasmodium falciparum, which causes malaria), I would be happy to help! Please provide more context or specify the particular protozoan of interest.

Calmodulin is a small, ubiquitous calcium-binding protein that plays a critical role in various intracellular signaling pathways. It functions as a calcium sensor, binding to and regulating the activity of numerous target proteins upon calcium ion (Ca^2+^) binding. Calmodulin is expressed in all eukaryotic cells and participates in many cellular processes, including muscle contraction, neurotransmitter release, gene expression, metabolism, and cell cycle progression.

The protein contains four EF-hand motifs that can bind Ca^2+^ ions. Upon calcium binding, conformational changes occur in the calmodulin structure, exposing hydrophobic surfaces that facilitate its interaction with target proteins. Calmodulin's targets include enzymes (such as protein kinases and phosphatases), ion channels, transporters, and cytoskeletal components. By modulating the activity of these proteins, calmodulin helps regulate essential cellular functions in response to changes in intracellular Ca^2+^ concentrations.

Calmodulin's molecular weight is approximately 17 kDa, and it consists of a single polypeptide chain with 148-150 amino acid residues. The protein can be found in both the cytoplasm and the nucleus of cells. In addition to its role as a calcium sensor, calmodulin has been implicated in various pathological conditions, including cancer, neurodegenerative diseases, and cardiovascular disorders.

Clenbuterol is a sympathomimetic amine, which is a type of medication that stimulates the sympathetic nervous system. It is primarily used as a bronchodilator to treat asthma and other respiratory disorders because it helps to relax the muscles in the airways and increase airflow to the lungs.

Clenbuterol works by binding to beta-2 receptors in the body, which triggers a series of reactions that lead to bronchodilation. However, it also has anabolic effects, which means that it can promote muscle growth and fat loss. This has led to its abuse as a performance-enhancing drug among athletes and bodybuilders.

It's important to note that Clenbuterol is not approved for use in humans in many countries, including the United States, due to concerns about its potential side effects and lack of proven benefits for athletic performance. It is also banned by most major sports organizations. The use of Clenbuterol for non-medical purposes can be dangerous and may lead to serious health complications, such as heart problems, muscle tremors, and anxiety.

I cannot provide a medical definition for "carps" as it is not a term used in medicine. The term "carp" refers to a type of freshwater fish that belongs to the family Cyprinidae. If you meant to ask about something else, please provide more context or clarify your question.

Nucleic acid hybridization is a process in molecular biology where two single-stranded nucleic acids (DNA, RNA) with complementary sequences pair together to form a double-stranded molecule through hydrogen bonding. The strands can be from the same type of nucleic acid or different types (i.e., DNA-RNA or DNA-cDNA). This process is commonly used in various laboratory techniques, such as Southern blotting, Northern blotting, polymerase chain reaction (PCR), and microarray analysis, to detect, isolate, and analyze specific nucleic acid sequences. The hybridization temperature and conditions are critical to ensure the specificity of the interaction between the two strands.

MEF2 (Myocyte Enhancer Factor-2) transcription factors are a family of proteins that regulate the transcription of genes, particularly in muscle cells. They play crucial roles in the development, growth, and maintenance of skeletal, cardiac, and smooth muscles. MEF2 transcription factors bind to specific DNA sequences, known as MEF2 response elements (MREs), in the promoter regions of target genes. This binding can either activate or repress gene transcription, depending on the context and interacting proteins. MEF2 transcription factors are involved in various cellular processes, such as muscle differentiation, metabolism, and stress responses. Dysregulation of MEF2 transcription factors has been implicated in several diseases, including muscular dystrophies, cardiovascular disorders, and neurodegenerative conditions.

The temporalis muscle is a fan-shaped muscle located in the lateral aspect of the head, in the temporal fossa region. It belongs to the group of muscles known as muscles of mastication, responsible for chewing movements. The temporalis muscle has its origin at the temporal fossa and inserts into the coronoid process and ramus of the mandible. Its main function is to retract the mandible and assist in closing the jaw.

Hyperthyroidism is a medical condition characterized by an excessive production and release of thyroid hormones from the thyroid gland, leading to an increased metabolic rate in various body systems. The thyroid gland, located in the front of the neck, produces two main thyroid hormones: triiodothyronine (T3) and thyroxine (T4). These hormones play crucial roles in regulating many bodily functions, including heart rate, digestion, energy levels, and mood.

In hyperthyroidism, the elevated levels of T3 and T4 can cause a wide range of symptoms, such as rapid heartbeat, weight loss, heat intolerance, increased appetite, tremors, anxiety, and sleep disturbances. Some common causes of hyperthyroidism include Graves' disease, toxic adenoma, Plummer's disease (toxic multinodular goiter), and thyroiditis. Proper diagnosis and treatment are essential to manage the symptoms and prevent potential complications associated with this condition.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

B-lymphocytes, also known as B-cells, are a type of white blood cell that plays a key role in the immune system's response to infection. They are responsible for producing antibodies, which are proteins that help to neutralize or destroy pathogens such as bacteria and viruses.

When a B-lymphocyte encounters a pathogen, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies specific to the antigens on the surface of the pathogen. These antibodies bind to the pathogen, marking it for destruction by other immune cells such as neutrophils and macrophages.

B-lymphocytes also have a role in presenting antigens to T-lymphocytes, another type of white blood cell involved in the immune response. This helps to stimulate the activation and proliferation of T-lymphocytes, which can then go on to destroy infected cells or help to coordinate the overall immune response.

Overall, B-lymphocytes are an essential part of the adaptive immune system, providing long-lasting immunity to previously encountered pathogens and helping to protect against future infections.

The pectoralis muscles are a group of chest muscles that are primarily involved in the movement and stabilization of the shoulder joint. They consist of two individual muscles: the pectoralis major and the pectoralis minor.

1. Pectoralis Major: This is the larger and more superficial of the two muscles, lying just under the skin and fat of the chest wall. It has two heads of origin - the clavicular head arises from the medial half of the clavicle (collarbone), while the sternocostal head arises from the anterior surface of the sternum (breastbone) and the upper six costal cartilages. Both heads insert onto the lateral lip of the bicipital groove of the humerus (upper arm bone). The primary actions of the pectoralis major include flexion, adduction, and internal rotation of the shoulder joint.

2. Pectoralis Minor: This is a smaller, triangular muscle that lies deep to the pectoralis major. It originates from the third, fourth, and fifth ribs near their costal cartilages and inserts onto the coracoid process of the scapula (shoulder blade). The main function of the pectoralis minor is to pull the scapula forward and downward, helping to stabilize the shoulder joint and aiding in deep inspiration during breathing.

Together, these muscles play essential roles in various movements such as pushing, pulling, and hugging, making them crucial for daily activities and athletic performance.

Hypertrophy, in the context of physiology and pathology, refers to an increase in the size of an organ or tissue due to an enlargement of its constituent cells. It is often used to describe the growth of muscle cells (myocytes) in response to increased workload or hormonal stimulation, resulting in an increase in muscle mass. However, hypertrophy can also occur in other organs such as the heart (cardiac hypertrophy) in response to high blood pressure or valvular heart disease.

It is important to note that while hypertrophy involves an increase in cell size, hyperplasia refers to an increase in cell number. In some cases, both hypertrophy and hyperplasia can occur together, leading to a significant increase in the overall size and function of the organ or tissue.

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

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.

Striated muscle, also known as skeletal or voluntary muscle, is a type of muscle tissue that is characterized by the presence of distinct light and dark bands, or striations, when viewed under a microscope. These striations correspond to the arrangement of sarcomeres, which are the functional units of muscle fibers.

Striated muscle is under voluntary control, meaning that it is consciously activated by signals from the nervous system. It is attached to bones via tendons and is responsible for producing movements of the body. Striated muscle fibers are multinucleated, meaning that they contain many nuclei, and are composed of numerous myofibrils, which are rope-like structures that run the length of the fiber.

The myofibrils are composed of thick and thin filaments that slide past each other to cause muscle contraction. The thick filaments are made up of the protein myosin, while the thin filaments are composed of actin, tropomyosin, and troponin. When a nerve impulse arrives at the muscle fiber, it triggers the release of calcium ions from the sarcoplasmic reticulum, which bind to troponin and cause a conformational change that exposes the binding sites on actin for myosin. The myosin heads then bind to the actin filaments and pull them towards the center of the sarcomere, causing the muscle fiber to shorten and contract.

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

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

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

Trypsin is a proteolytic enzyme, specifically a serine protease, that is secreted by the pancreas as an inactive precursor, trypsinogen. Trypsinogen is converted into its active form, trypsin, in the small intestine by enterokinase, which is produced by the intestinal mucosa.

Trypsin plays a crucial role in digestion by cleaving proteins into smaller peptides at specific arginine and lysine residues. This enzyme helps to break down dietary proteins into amino acids, allowing for their absorption and utilization by the body. Additionally, trypsin can activate other zymogenic pancreatic enzymes, such as chymotrypsinogen and procarboxypeptidases, thereby contributing to overall protein digestion.

Antibody specificity refers to the ability of an antibody to bind to a specific epitope or antigenic determinant on an antigen. Each antibody has a unique structure that allows it to recognize and bind to a specific region of an antigen, typically a small portion of the antigen's surface made up of amino acids or sugar residues. This highly specific binding is mediated by the variable regions of the antibody's heavy and light chains, which form a pocket that recognizes and binds to the epitope.

The specificity of an antibody is determined by its unique complementarity-determining regions (CDRs), which are loops of amino acids located in the variable domains of both the heavy and light chains. The CDRs form a binding site that recognizes and interacts with the epitope on the antigen. The precise fit between the antibody's binding site and the epitope is critical for specificity, as even small changes in the structure of either can prevent binding.

Antibody specificity is important in immune responses because it allows the immune system to distinguish between self and non-self antigens. This helps to prevent autoimmune reactions where the immune system attacks the body's own cells and tissues. Antibody specificity also plays a crucial role in diagnostic tests, such as ELISA assays, where antibodies are used to detect the presence of specific antigens in biological samples.

Masticatory muscles are a group of skeletal muscles responsible for the mastication (chewing) process in humans and other animals. They include:

1. Masseter muscle: This is the primary muscle for chewing and is located on the sides of the face, running from the lower jawbone (mandible) to the cheekbone (zygomatic arch). It helps close the mouth and elevate the mandible during chewing.

2. Temporalis muscle: This muscle is situated in the temporal region of the skull, covering the temple area. It assists in closing the jaw, retracting the mandible, and moving it sideways during chewing.

3. Medial pterygoid muscle: Located deep within the cheek, near the angle of the lower jaw, this muscle helps move the mandible forward and grind food during chewing. It also contributes to closing the mouth.

4. Lateral pterygoid muscle: Found inside the ramus (the vertical part) of the mandible, this muscle has two heads - superior and inferior. The superior head helps open the mouth by pulling the temporomandibular joint (TMJ) downwards, while the inferior head assists in moving the mandible sideways during chewing.

These muscles work together to enable efficient chewing and food breakdown, preparing it for swallowing and digestion.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

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

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

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

Immunoglobulin kappa-chains are one of the two types of light chains (the other being lambda-chains) that make up an immunoglobulin molecule, also known as an antibody. These light chains combine with heavy chains to form the antigen-binding site of an antibody, which is responsible for recognizing and binding to specific antigens or foreign substances in the body.

Kappa-chains contain a variable region that differs between different antibodies and contributes to the diversity of the immune system's response to various antigens. They also have a constant region, which is consistent across all kappa-chains. Approximately 60% of all human antibodies contain kappa-chains, while the remaining 40% contain lambda-chains. The relative proportions of kappa and lambda chains can be used in diagnostic tests to identify clonal expansions of B cells, which may indicate a malignancy such as multiple myeloma or lymphoma.

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.

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).

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.

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.

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

Examples of biological models include:

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

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

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

Peptide mapping is a technique used in proteomics and analytical chemistry to analyze and identify the sequence and structure of peptides or proteins. This method involves breaking down a protein into smaller peptide fragments using enzymatic or chemical digestion, followed by separation and identification of these fragments through various analytical techniques such as liquid chromatography (LC) and mass spectrometry (MS).

The resulting peptide map serves as a "fingerprint" of the protein, providing information about its sequence, modifications, and structure. Peptide mapping can be used for a variety of applications, including protein identification, characterization of post-translational modifications, and monitoring of protein degradation or cleavage.

In summary, peptide mapping is a powerful tool in proteomics that enables the analysis and identification of proteins and their modifications at the peptide level.

Mollusca is not a medical term per se, but a major group of invertebrate animals that includes snails, clams, octopuses, and squids. However, medically, some mollusks can be relevant as they can act as vectors for various diseases, such as schistosomiasis (transmitted by freshwater snails) and fascioliasis (transmitted by aquatic snails). Therefore, a medical definition might describe Mollusca as a phylum of mostly marine invertebrates that can sometimes play a role in the transmission of certain infectious diseases.

Alpha-globulins are a group of proteins present in blood plasma, which are classified based on their electrophoretic mobility. They migrate between albumin and beta-globulins during electrophoresis. Alpha-globulins include several proteins, such as alpha-1 antitrypsin, alpha-1 acid glycoprotein, and haptoglobin. These proteins play various roles in the body, including transporting and regulating other molecules, participating in immune responses, and maintaining oncotic pressure in blood vessels.

The Quadriceps muscle, also known as the Quadriceps Femoris, is a large muscle group located in the front of the thigh. It consists of four individual muscles - the Rectus Femoris, Vastus Lateralis, Vastus Intermedius, and Vastus Medialis. These muscles work together to extend the leg at the knee joint and flex the thigh at the hip joint. The Quadriceps muscle is crucial for activities such as walking, running, jumping, and kicking.

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

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.

Actinin is a protein that belongs to the family of actin-binding proteins. It plays an important role in the organization and stability of the cytoskeleton, which is the structural framework of a cell. Specifically, actinin crosslinks actin filaments into bundles or networks, providing strength and rigidity to the cell structure. There are several isoforms of actinin, with alpha-actinin and gamma-actinin being widely studied. Alpha-actinin is found in the Z-discs of sarcomeres in muscle cells, where it helps anchor actin filaments and maintains the structural integrity of the muscle. Gamma-actinin is primarily located at cell-cell junctions and participates in cell adhesion and signaling processes.

Calcium-binding proteins (CaBPs) are a diverse group of proteins that have the ability to bind calcium ions (Ca^2+^) with high affinity and specificity. They play crucial roles in various cellular processes, including signal transduction, muscle contraction, neurotransmitter release, and protection against oxidative stress.

The binding of calcium ions to these proteins induces conformational changes that can either activate or inhibit their functions. Some well-known CaBPs include calmodulin, troponin C, S100 proteins, and parvalbumins. These proteins are essential for maintaining calcium homeostasis within cells and for mediating the effects of calcium as a second messenger in various cellular signaling pathways.

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

Beta-2 microglobulin (β2M) is a small protein that is a component of the major histocompatibility complex class I molecule, which plays a crucial role in the immune system. It is found on the surface of almost all nucleated cells in the body and is involved in presenting intracellular peptides to T-cells for immune surveillance.

β2M is produced at a relatively constant rate by cells throughout the body and is freely filtered by the glomeruli in the kidneys. Under normal circumstances, most of the filtrated β2M is reabsorbed and catabolized in the proximal tubules of the nephrons. However, when the glomerular filtration rate (GFR) is decreased, as in chronic kidney disease (CKD), the reabsorption capacity of the proximal tubules becomes overwhelmed, leading to increased levels of β2M in the blood and its subsequent appearance in the urine.

Elevated serum and urinary β2M levels have been associated with various clinical conditions, such as CKD, multiple myeloma, autoimmune disorders, and certain infectious diseases. Measuring β2M concentrations can provide valuable information for diagnostic, prognostic, and monitoring purposes in these contexts.

Smooth muscle myocytes are specialized cells that make up the contractile portion of non-striated, or smooth, muscles. These muscles are found in various organs and structures throughout the body, including the walls of blood vessels, the digestive system, the respiratory system, and the reproductive system.

Smooth muscle myocytes are smaller than their striated counterparts (skeletal and cardiac muscle cells) and have a single nucleus. They lack the distinctive banding pattern seen in striated muscles and instead have a uniform appearance of actin and myosin filaments. Smooth muscle myocytes are controlled by the autonomic nervous system, which allows them to contract and relax involuntarily.

These cells play an essential role in many physiological processes, such as regulating blood flow, moving food through the digestive tract, and facilitating childbirth. They can also contribute to various pathological conditions, including hypertension, atherosclerosis, and gastrointestinal disorders.

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

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

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

Skeletal myoblasts are the precursor cells responsible for the formation and repair of skeletal muscle fibers. They are also known as satellite cells, located in a quiescent state between the basal lamina and sarcolemma of mature muscle fibers. Upon muscle injury or damage, these cells become activated, proliferate, differentiate into myocytes, align with existing muscle fibers, and fuse to form new muscle fibers or repair damaged ones. This process is crucial for postnatal growth, maintenance, and regeneration of skeletal muscles.

Rho-associated kinases (ROCKs) are serine/threonine kinases that are involved in the regulation of various cellular processes, including actin cytoskeleton organization, cell migration, and gene expression. They are named after their association with the small GTPase RhoA, which activates them upon binding.

ROCKs exist as two isoforms, ROCK1 and ROCK2, which share a high degree of sequence homology and have similar functions. They contain several functional domains, including a kinase domain, a coiled-coil region that mediates protein-protein interactions, and a Rho-binding domain (RBD) that binds to active RhoA.

Once activated by RhoA, ROCKs phosphorylate a variety of downstream targets, including myosin light chain (MLC), LIM kinase (LIMK), and moesin, leading to the regulation of actomyosin contractility, stress fiber formation, and focal adhesion turnover. Dysregulation of ROCK signaling has been implicated in various pathological conditions, such as cancer, cardiovascular diseases, neurological disorders, and fibrosis. Therefore, ROCKs have emerged as promising therapeutic targets for the treatment of these diseases.

Papain is defined as a proteolytic enzyme that is derived from the latex of the papaya tree (Carica papaya). It has the ability to break down other proteins into smaller peptides or individual amino acids. Papain is widely used in various industries, including the food industry for tenderizing meat and brewing beer, as well as in the medical field for its digestive and anti-inflammatory properties.

In medicine, papain is sometimes used topically to help heal burns, wounds, and skin ulcers. It can also be taken orally to treat indigestion, parasitic infections, and other gastrointestinal disorders. However, its use as a medical treatment is not widely accepted and more research is needed to establish its safety and efficacy.

An epitope is a specific region on the surface of an antigen (a molecule that can trigger an immune response) that is recognized by an antibody, B-cell receptor, or T-cell receptor. It is also commonly referred to as an antigenic determinant. Epitopes are typically composed of linear amino acid sequences or conformational structures made up of discontinuous amino acids in the antigen. They play a crucial role in the immune system's ability to differentiate between self and non-self molecules, leading to the targeted destruction of foreign substances like viruses and bacteria. Understanding epitopes is essential for developing vaccines, diagnostic tests, and immunotherapies.

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

Myeloma proteins, also known as monoclonal immunoglobulins or M-proteins, are entire or abnormal immunoglobulin (antibody) molecules produced by a single clone of plasma cells, which are malignant in the case of multiple myeloma and some related disorders. These proteins accumulate in the blood and/or urine and can cause damage to various organs and tissues.

In multiple myeloma, the excessive proliferation of these plasma cells leads to the overproduction of a single type of immunoglobulin or its fragments, which can be detected and quantified in serum and/or urine electrophoresis. The most common types of myeloma proteins are IgG and IgA, followed by light chains (Bence Jones proteins) and, less frequently, IgD and IgM.

The presence and levels of myeloma proteins are important diagnostic markers for multiple myeloma and related disorders, such as monoclonal gammopathy of undetermined significance (MGUS) and Waldenström macroglobulinemia. Regular monitoring of these proteins helps assess the disease's activity, response to treatment, and potential complications like kidney dysfunction or amyloidosis.

A plasmacytoma is a discrete tumor mass that is composed of neoplastic plasma cells, which are a type of white blood cell found in the bone marrow. Plasmacytomas can be solitary (a single tumor) or multiple (many tumors), and they can develop in various locations throughout the body.

Solitary plasmacytoma is a rare cancer that typically affects older adults, and it usually involves a single bone lesion, most commonly found in the vertebrae, ribs, or pelvis. In some cases, solitary plasmacytomas can also occur outside of the bone (extramedullary plasmacytoma), which can affect soft tissues such as the upper respiratory tract, gastrointestinal tract, or skin.

Multiple myeloma is a more common and aggressive cancer that involves multiple plasmacytomas in the bone marrow, leading to the replacement of normal bone marrow cells with malignant plasma cells. This can result in various symptoms such as bone pain, anemia, infections, and kidney damage.

The diagnosis of plasmacytoma typically involves a combination of imaging studies, biopsy, and laboratory tests to assess the extent of the disease and determine the appropriate treatment plan. Treatment options for solitary plasmacytoma may include surgery or radiation therapy, while multiple myeloma is usually treated with chemotherapy, targeted therapy, immunotherapy, and/or stem cell transplantation.

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

Core binding factors (CBFs) are a group of proteins that play critical roles in the development and differentiation of hematopoietic cells, which are the cells responsible for the formation of blood and immune systems. The term "core binding factor" refers to the ability of these proteins to bind to specific DNA sequences, known as core binding sites, and regulate gene transcription.

The two main CBFs are:

1. Core Binding Factor Alpha (CBF-α): Also known as RUNX1 or AML1, this protein forms a complex with Core Binding Factor Beta (CBF-β) to regulate the expression of genes involved in hematopoiesis. Mutations in CBF-α have been associated with various types of leukemia and myelodysplastic syndromes.
2. Core Binding Factor Beta (CBF-β): Also known as PEBP2B, this protein partners with CBF-α to form the active transcription factor complex. CBF-β enhances the DNA binding affinity and stability of the CBF-α/CBF-β heterodimer.

In certain types of leukemia, chromosomal abnormalities can lead to the formation of fusion proteins involving CBF-α or CBF-β. These fusion proteins disrupt normal hematopoiesis and contribute to the development of cancer. Examples include the t(8;21) translocation that creates the AML1/ETO fusion protein in acute myeloid leukemia (AML) and the inv(16) inversion that forms the CBFB-MYH11 fusion protein in AML.

I'm sorry for any confusion, but "Muscular Dystrophy, Animal" is not a standard medical term. Muscular Dystrophy is a group of genetic disorders that cause progressive weakness and loss of muscle mass. They are primarily human diseases and there are no known animal models of muscular dystrophy that directly correspond to any type of muscular dystrophy in humans.

However, scientists often use animals (like mice, dogs, and cats) as models for human diseases, including various types of muscular dystrophies. These animal models are used to study the disease process and to test potential treatments. For example, the mdx mouse is a well-known model of Duchenne Muscular Dystrophy (DMD), which is caused by a mutation in the dystrophin gene. This mouse lacks the muscle protein dystrophin, similar to humans with DMD, and shows many of the same symptoms, making it a valuable tool for research.

Calcium-transporting ATPases, also known as calcium pumps, are a type of enzyme that use the energy from ATP (adenosine triphosphate) hydrolysis to transport calcium ions across membranes against their concentration gradient. This process helps maintain low intracellular calcium concentrations and is essential for various cellular functions, including muscle contraction, neurotransmitter release, and gene expression.

There are two main types of calcium-transporting ATPases: the sarcoplasmic/endoplasmic reticulum Ca^2+^-ATPase (SERCA) and the plasma membrane Ca^2+^-ATPase (PMCA). SERCA is found in the sarcoplasmic reticulum of muscle cells and endoplasmic reticulum of other cell types, where it pumps calcium ions into these organelles to initiate muscle relaxation or signal transduction. PMCA, on the other hand, is located in the plasma membrane and extrudes calcium ions from the cell to maintain low cytosolic calcium concentrations.

Calcium-transporting ATPases play a crucial role in maintaining calcium homeostasis in cells and are important targets for drug development in various diseases, including heart failure, hypertension, and neurological disorders.

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.

Triiodothyronine (T3) is a thyroid hormone, specifically the active form of thyroid hormone, that plays a critical role in the regulation of metabolism, growth, and development in the human body. It is produced by the thyroid gland through the iodination and coupling of the amino acid tyrosine with three atoms of iodine. T3 is more potent than its precursor, thyroxine (T4), which has four iodine atoms, as T3 binds more strongly to thyroid hormone receptors and accelerates metabolic processes at the cellular level.

In circulation, about 80% of T3 is bound to plasma proteins, while the remaining 20% is unbound or free, allowing it to enter cells and exert its biological effects. The primary functions of T3 include increasing the rate of metabolic reactions, promoting protein synthesis, enhancing sensitivity to catecholamines (e.g., adrenaline), and supporting normal brain development during fetal growth and early infancy. Imbalances in T3 levels can lead to various medical conditions, such as hypothyroidism or hyperthyroidism, which may require clinical intervention and management.

Core Binding Factor-beta (CBF-β) is a subunit of the Core Binding Factor (CBF), which is a heterodimeric transcription factor composed of a DNA-binding alpha subunit and a non-DNA binding beta subunit. The CBF plays a crucial role in hematopoiesis, the process of blood cell development, by regulating the expression of various genes involved in this process.

The CBF-β subunit is a 36 kDa protein that is encoded by the CBFB gene in humans. It does not bind to DNA directly but instead forms a complex with the DNA-binding alpha subunit, which is either RUNX1 (also known as AML1), RUNX2, or RUNX3. The CBF-β subunit stabilizes the interaction between the alpha subunit and DNA, enhances its DNA-binding affinity, and increases the transcriptional activity of the complex.

Mutations in the CBFB gene have been associated with several hematological disorders, including acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and familial platelet disorder with predisposition to AML (FPD/AML). These mutations can lead to aberrant transcriptional regulation of hematopoietic genes, resulting in the development of these disorders.

Troponin I is a protein that is found in the cardiac muscle cells (myocytes) of the heart. It is a component of the troponin complex, which also includes troponin C and troponin T, that regulates the calcium-mediated interaction between actin and myosin filaments during muscle contraction.

Troponin I is specific to the cardiac muscle tissue, making it a useful biomarker for detecting damage to the heart muscle. When there is injury or damage to the heart muscle cells, such as during a heart attack (myocardial infarction), troponin I is released into the bloodstream.

Measurement of cardiac troponin I levels in the blood is used in the diagnosis and management of acute coronary syndrome (ACS) and other conditions that cause damage to the heart muscle. Elevated levels of troponin I in the blood are indicative of myocardial injury, and the degree of elevation can help determine the severity of the injury.

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.

Troponin T is a subunit of the troponin complex, which is a protein complex that plays a crucial role in muscle contraction. In particular, Troponin T is responsible for binding the troponin complex to tropomyosin, another protein that helps regulate muscle contraction.

In the context of medical diagnostics, Troponin T is often measured as a biomarker for heart damage. When heart muscle cells are damaged or die, such as in a myocardial infarction (heart attack), troponin T is released into the bloodstream. Therefore, measuring the levels of Troponin T in the blood can help diagnose and assess the severity of heart damage.

It's important to note that Troponin T is specific to cardiac muscle cells, which makes it a more reliable biomarker for heart damage than other markers that may also be found in skeletal muscle cells. However, it's worth noting that Troponin T levels can also be elevated in conditions other than heart attacks, such as heart failure, myocarditis, and pulmonary embolism, so clinical context is important when interpreting test results.

The heart atria are the upper chambers of the heart that receive blood from the veins and deliver it to the lower chambers, or ventricles. There are two atria in the heart: the right atrium receives oxygen-poor blood from the body and pumps it into the right ventricle, which then sends it to the lungs to be oxygenated; and the left atrium receives oxygen-rich blood from the lungs and pumps it into the left ventricle, which then sends it out to the rest of the body. The atria contract before the ventricles during each heartbeat, helping to fill the ventricles with blood and prepare them for contraction.

Calcium-calmodulin-dependent protein kinases (CAMKs) are a family of enzymes that play a crucial role in intracellular signaling pathways. They are activated by the binding of calcium ions and calmodulin, a ubiquitous calcium-binding protein, to their regulatory domain.

Once activated, CAMKs phosphorylate specific serine or threonine residues on target proteins, thereby modulating their activity, localization, or stability. This post-translational modification is essential for various cellular processes, including synaptic plasticity, gene expression, metabolism, and cell cycle regulation.

There are several subfamilies of CAMKs, including CaMKI, CaMKII, CaMKIII (also known as CaMKIV), and CaMK kinase (CaMKK). Each subfamily has distinct structural features, substrate specificity, and regulatory mechanisms. Dysregulation of CAMK signaling has been implicated in various pathological conditions, such as neurodegenerative diseases, cancer, and cardiovascular disorders.

Immunoglobulin fragments refer to the smaller protein units that are formed by the digestion or break-down of an intact immunoglobulin, also known as an antibody. Immunoglobulins are large Y-shaped proteins produced by the immune system to identify and neutralize foreign substances such as pathogens or toxins. They consist of two heavy chains and two light chains, held together by disulfide bonds.

The digestion or break-down of an immunoglobulin can occur through enzymatic cleavage, which results in the formation of distinct fragments. The most common immunoglobulin fragments are:

1. Fab (Fragment, antigen binding) fragments: These are formed by the digestion of an intact immunoglobulin using the enzyme papain. Each Fab fragment contains a single antigen-binding site, consisting of a portion of one heavy chain and one light chain. The Fab fragments retain their ability to bind to specific antigens.
2. Fc (Fragment, crystallizable) fragments: These are formed by the digestion of an intact immunoglobulin using the enzyme pepsin or through the natural breakdown process in the body. The Fc fragment contains the constant region of both heavy chains and is responsible for effector functions such as complement activation, binding to Fc receptors on immune cells, and antibody-dependent cellular cytotoxicity (ADCC).

These immunoglobulin fragments play crucial roles in various immune responses and diagnostic applications. For example, Fab fragments can be used in immunoassays for the detection of specific antigens, while Fc fragments can mediate effector functions that help eliminate pathogens or damaged cells from the body.

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

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

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

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.

Restriction mapping is a technique used in molecular biology to identify the location and arrangement of specific restriction endonuclease recognition sites within a DNA molecule. Restriction endonucleases are enzymes that cut double-stranded DNA at specific sequences, producing fragments of various lengths. By digesting the DNA with different combinations of these enzymes and analyzing the resulting fragment sizes through techniques such as agarose gel electrophoresis, researchers can generate a restriction map - a visual representation of the locations and distances between recognition sites on the DNA molecule. This information is crucial for various applications, including cloning, genome analysis, and genetic engineering.

A hindlimb, also known as a posterior limb, is one of the pair of extremities that are located distally to the trunk in tetrapods (four-legged vertebrates) and include mammals, birds, reptiles, and amphibians. In humans and other primates, hindlimbs are equivalent to the lower limbs, which consist of the thigh, leg, foot, and toes.

The primary function of hindlimbs is locomotion, allowing animals to move from one place to another. However, they also play a role in other activities such as balance, support, and communication. In humans, the hindlimbs are responsible for weight-bearing, standing, walking, running, and jumping.

In medical terminology, the term "hindlimb" is not commonly used to describe human anatomy. Instead, healthcare professionals use terms like lower limbs or lower extremities to refer to the same region of the body. However, in comparative anatomy and veterinary medicine, the term hindlimb is still widely used to describe the corresponding structures in non-human animals.

Immunoglobulin lambda-chains (Igλ) are one type of light chain found in the immunoglobulins, also known as antibodies. Antibodies are proteins that play a crucial role in the immune system's response to foreign substances, such as bacteria and viruses.

Immunoglobulins are composed of two heavy chains and two light chains, which are interconnected by disulfide bonds. There are two types of light chains: kappa (κ) and lambda (λ). Igλ chains are one type of light chain that can be found in association with heavy chains to form functional antibodies.

Igλ chains contain a variable region, which is responsible for recognizing and binding to specific antigens, and a constant region, which determines the class of the immunoglobulin (e.g., IgA, IgD, IgE, IgG, or IgM).

In humans, approximately 60% of all antibodies contain Igλ chains, while the remaining 40% contain Igκ chains. The ratio of Igλ to Igκ chains can vary depending on the type of immunoglobulin and its function in the immune response.

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

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

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

Exons are the coding regions of DNA that remain in the mature, processed mRNA after the removal of non-coding intronic sequences during RNA splicing. These exons contain the information necessary to encode proteins, as they specify the sequence of amino acids within a polypeptide chain. The arrangement and order of exons can vary between different genes and even between different versions of the same gene (alternative splicing), allowing for the generation of multiple protein isoforms from a single gene. This complexity in exon structure and usage significantly contributes to the diversity and functionality of the proteome.

DNA restriction enzymes, also known as restriction endonucleases, are a type of enzyme that cut double-stranded DNA at specific recognition sites. These enzymes are produced by bacteria and archaea as a defense mechanism against foreign DNA, such as that found in bacteriophages (viruses that infect bacteria).

Restriction enzymes recognize specific sequences of nucleotides (the building blocks of DNA) and cleave the phosphodiester bonds between them. The recognition sites for these enzymes are usually palindromic, meaning that the sequence reads the same in both directions when facing the opposite strands of DNA.

Restriction enzymes are widely used in molecular biology research for various applications such as genetic engineering, genome mapping, and DNA fingerprinting. They allow scientists to cut DNA at specific sites, creating precise fragments that can be manipulated and analyzed. The use of restriction enzymes has been instrumental in the development of recombinant DNA technology and the Human Genome Project.

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

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.

A binding site on an antibody refers to the specific region on the surface of the antibody molecule that can recognize and bind to a specific antigen. Antibodies are proteins produced by the immune system in response to the presence of foreign substances called antigens. They have two main functions: to neutralize the harmful effects of antigens and to help eliminate them from the body.

The binding site of an antibody is located at the tips of its Y-shaped structure, formed by the variable regions of the heavy and light chains of the antibody molecule. These regions contain unique amino acid sequences that determine the specificity of the antibody for a particular antigen. The binding site can recognize and bind to a specific epitope or region on the antigen, forming an antigen-antibody complex.

The binding between the antibody and antigen is highly specific and depends on non-covalent interactions such as hydrogen bonds, van der Waals forces, and electrostatic attractions. This interaction plays a crucial role in the immune response, as it allows the immune system to recognize and eliminate pathogens and other foreign substances from the body.

Biomechanics is the application of mechanical laws to living structures and systems, particularly in the field of medicine and healthcare. A biomechanical phenomenon refers to a observable event or occurrence that involves the interaction of biological tissues or systems with mechanical forces. These phenomena can be studied at various levels, from the molecular and cellular level to the tissue, organ, and whole-body level.

Examples of biomechanical phenomena include:

1. The way that bones and muscles work together to produce movement (known as joint kinematics).
2. The mechanical behavior of biological tissues such as bone, cartilage, tendons, and ligaments under various loads and stresses.
3. The response of cells and tissues to mechanical stimuli, such as the way that bone tissue adapts to changes in loading conditions (known as Wolff's law).
4. The biomechanics of injury and disease processes, such as the mechanisms of joint injury or the development of osteoarthritis.
5. The use of mechanical devices and interventions to treat medical conditions, such as orthopedic implants or assistive devices for mobility impairments.

Understanding biomechanical phenomena is essential for developing effective treatments and prevention strategies for a wide range of medical conditions, from musculoskeletal injuries to neurological disorders.

Immunoglobulin J-chains are small protein structures that play a role in the assembly and structure of certain types of antibodies, specifically IgM and IgA. The J-chain is a polypeptide chain that contains multiple cysteine residues, which allow it to form disulfide bonds with the heavy chains of IgM and IgA molecules.

In IgM antibodies, the J-chain helps to link the five identical heavy chain units together to form a pentameric structure. In IgA antibodies, the J-chain links two dimeric structures together to form a tetrameric structure. This polymerization of IgM and IgA molecules is important for their function in the immune system, as it allows them to form large complexes that can effectively agglutinate and neutralize pathogens.

The J-chain is synthesized by a specialized group of B cells called plasma cells, which are responsible for producing and secreting antibodies. Once synthesized, the J-chain is covalently linked to the heavy chains of IgM or IgA molecules during their assembly in the endoplasmic reticulum of the plasma cell.

Overall, the Immunoglobulin J-chain plays a crucial role in the structure and function of certain classes of antibodies, contributing to their ability to effectively combat pathogens and protect the body from infection.

Kinesin is not a medical term per se, but a term from the field of cellular biology. However, understanding how kinesins work is important in the context of medical and cellular research.

Kinesins are a family of motor proteins that play a crucial role in transporting various cargoes within cells, such as vesicles, organelles, and chromosomes. They move along microtubule filaments, using the energy derived from ATP hydrolysis to generate mechanical force and motion. This process is essential for several cellular functions, including intracellular transport, mitosis, and meiosis.

In a medical context, understanding kinesin function can provide insights into various diseases and conditions related to impaired intracellular transport, such as neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease, and Huntington's disease) and certain genetic disorders affecting motor neurons. Research on kinesins can potentially lead to the development of novel therapeutic strategies targeting these conditions.

Immunoglobulin allotypes refer to the genetic variations in the constant region of immunoglobulins (antibodies) that are caused by differences in the amino acid sequences. These variations are determined by specific alleles at polymorphic loci on chromosome 14 and 22, which are inherited in a Mendelian fashion.

Immunoglobulin allotypes can be used as markers for ancestry, immune response, and the identification of tissue types in transplantation. They also play a role in the regulation of the immune response and can affect the affinity and specificity of antibodies.

It's important to note that while immunoglobulin allotypes are inherited and do not change over an individual's lifetime, they should not be confused with immunoglobulin isotypes (IgA, IgD, IgE, IgG, and IgM) which refer to the different classes of antibodies that have distinct structures and functions.

The Immunoglobulin Joining Region (IgJ or J chain) is a polypeptide chain that is a component of certain immunoglobulins, specifically IgM and IgA. The J chain plays a crucial role in the polymerization of these immunoglobulins, allowing them to form higher-order structures such as pentamers (in the case of IgM) or dimers (in the case of IgA). This polymerization is important for the functioning of these immunoglobulins in the immune response. The J chain contains multiple cysteine residues that form disulfide bonds with each other and with the heavy chains of the immunoglobulin molecules, helping to stabilize the polymeric structure.

I'm sorry for any confusion, but there is no established medical or scientific definition for "Vitamin U." The term was used in the past to refer to a substance found in cabbage juice that seemed to help ulcers, but it's not recognized as a vitamin by modern nutrition standards. It's often referred to as methylmethionine or S-methylmethionine, which is a compound derived from the amino acid methionine. Please consult with a healthcare professional for medical advice.

Calcineurin is a calcium-calmodulin-activated serine/threonine protein phosphatase that plays a crucial role in signal transduction pathways involved in immune response and neuronal development. It consists of two subunits: the catalytic A subunit (calcineurin A) and the regulatory B subunit (calcineurin B). Calcineurin is responsible for dephosphorylating various substrates, including transcription factors, which leads to changes in their activity and ultimately affects gene expression. In the immune system, calcineurin plays a critical role in T-cell activation by dephosphorylating the nuclear factor of activated T-cells (NFAT), allowing it to translocate into the nucleus and induce the expression of cytokines and other genes involved in the immune response. Inhibitors of calcineurin, such as cyclosporine A and tacrolimus, are commonly used as immunosuppressive drugs to prevent organ rejection after transplantation.

Muscle weakness is a condition in which muscles cannot develop the expected level of physical force or power. This results in reduced muscle function and can be caused by various factors, including nerve damage, muscle diseases, or hormonal imbalances. Muscle weakness may manifest as difficulty lifting objects, maintaining posture, or performing daily activities. It is essential to consult a healthcare professional for proper diagnosis and treatment of muscle weakness.

Antibody diversity refers to the variety of different antibodies that an organism can produce in response to exposure to various antigens. This diversity is generated through a process called V(D)J recombination, which occurs during the development of B cells in the bone marrow.

The variable regions of heavy and light chains of antibody molecules are generated by the random selection and rearrangement of gene segments (V, D, and J) from different combinations. This results in a unique antigen-binding site for each antibody molecule, allowing the immune system to recognize and respond to a vast array of potential pathogens.

Further diversity is generated through the processes of somatic hypermutation and class switch recombination, which introduce additional changes in the variable regions of antibodies during an immune response. These processes allow for the affinity maturation of antibodies, where the binding strength between the antibody and antigen is increased over time, leading to a more effective immune response.

Overall, antibody diversity is critical for the adaptive immune system's ability to recognize and respond to a wide range of pathogens and protect against infection and disease.

Immunoglobulin delta-chains (IgD) are a type of heavy chain found in immunoglobulins, which are also known as antibodies. Antibodies are proteins that play a crucial role in the immune system's response to foreign substances, such as bacteria and viruses.

The heavy chains of an antibody consist of four polypeptide regions: the variable region, which varies between different antibodies and is responsible for recognizing and binding to specific antigens; and three constant regions, known as Cμ, Cγ, Cα, or Cδ, which determine the class of the antibody and its effector functions.

IgD heavy chains contain a single Cδ region and are found only in a small subset of antibodies, primarily located on the surface of mature B cells. IgD is co-expressed with IgM on the surface of naive B cells and plays a role in activating the immune response by binding to antigens and initiating signal transduction pathways that lead to B cell activation and differentiation into antibody-secreting plasma cells.

While the function of IgD is not fully understood, it is thought to play a role in regulating the immune response, including modulating allergic reactions and protecting against autoimmunity. Additionally, IgD has been found to have a role in the development and survival of B cells, as well as in the regulation of calcium signaling in B cells.

Cytoplasmic streaming, also known as cyclosis, is the movement or flow of cytoplasm and organelles within a eukaryotic cell. It is a type of intracellular transport that occurs in many types of cells, but it is particularly prominent in large, single-celled organisms such as algae and fungi.

During cytoplasmic streaming, the cytoplasm moves in a coordinated and organized manner, often in circular or spiral patterns. This movement is driven by the action of motor proteins, such as myosin, which interact with filamentous structures called actin filaments. The movement of the motor proteins along the actin filaments generates force, causing the cytoplasm and organelles to move.

Cytoplasmic streaming serves several functions in cells. It helps to distribute nutrients and metabolic products throughout the cell, and it also plays a role in the movement of organelles and other cellular components to specific locations within the cell. Additionally, cytoplasmic streaming can help to maintain the structural integrity of large, single-celled organisms by ensuring that their cytoplasm is evenly distributed.

Body weight is the measure of the force exerted on a scale or balance by an object's mass, most commonly expressed in units such as pounds (lb) or kilograms (kg). In the context of medical definitions, body weight typically refers to an individual's total weight, which includes their skeletal muscle, fat, organs, and bodily fluids.

Healthcare professionals often use body weight as a basic indicator of overall health status, as it can provide insights into various aspects of a person's health, such as nutritional status, metabolic function, and risk factors for certain diseases. For example, being significantly underweight or overweight can increase the risk of developing conditions like malnutrition, diabetes, heart disease, and certain types of cancer.

It is important to note that body weight alone may not provide a complete picture of an individual's health, as it does not account for factors such as muscle mass, bone density, or body composition. Therefore, healthcare professionals often use additional measures, such as body mass index (BMI), waist circumference, and blood tests, to assess overall health status more comprehensively.

Electrophoresis is a laboratory technique used in the field of molecular biology and chemistry to separate charged particles, such as DNA, RNA, or proteins, based on their size and charge. This technique uses an electric field to drive the movement of these charged particles through a medium, such as gel or liquid.

In electrophoresis, the sample containing the particles to be separated is placed in a matrix, such as a gel or a capillary tube, and an electric current is applied. The particles in the sample have a net charge, either positive or negative, which causes them to move through the matrix towards the oppositely charged electrode.

The rate at which the particles move through the matrix depends on their size and charge. Larger particles move more slowly than smaller ones, and particles with a higher charge-to-mass ratio move faster than those with a lower charge-to-mass ratio. By comparing the distance that each particle travels in the matrix, researchers can identify and quantify the different components of a mixture.

Electrophoresis has many applications in molecular biology and medicine, including DNA sequencing, genetic fingerprinting, protein analysis, and diagnosis of genetic disorders.

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.

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

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

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

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

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

Clathrin is a type of protein that plays a crucial role in the formation of coated vesicles within cells. These vesicles are responsible for transporting materials between different cellular compartments, such as from the plasma membrane to the endoplasmic reticulum or Golgi apparatus. Clathrin molecules form a lattice-like structure that curves around the vesicle, providing stability and shape to the coated vesicle. This process is known as clathrin-mediated endocytosis.

The formation of clathrin-coated vesicles begins with the recruitment of clathrin proteins to specific sites on the membrane, where they assemble into a polygonal lattice structure. As more clathrin molecules join the assembly, the lattice curves and eventually pinches off from the membrane, forming a closed vesicle. The clathrin coat then disassembles, releasing the vesicle to continue with its intracellular transport mission.

Disruptions in clathrin-mediated endocytosis can lead to various cellular dysfunctions and diseases, including neurodegenerative disorders and certain types of cancer.

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

The process of creating GMAs involves several steps:

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

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

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

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

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

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

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

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.

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

Physiological adaptation refers to the changes or modifications that occur in an organism's biological functions or structures as a result of environmental pressures or changes. These adaptations enable the organism to survive and reproduce more successfully in its environment. They can be short-term, such as the constriction of blood vessels in response to cold temperatures, or long-term, such as the evolution of longer limbs in animals that live in open environments.

In the context of human physiology, examples of physiological adaptation include:

1. Acclimatization: The process by which the body adjusts to changes in environmental conditions, such as altitude or temperature. For example, when a person moves to a high-altitude location, their body may produce more red blood cells to compensate for the lower oxygen levels, leading to improved oxygen delivery to tissues.

2. Exercise adaptation: Regular physical activity can lead to various physiological adaptations, such as increased muscle strength and endurance, enhanced cardiovascular function, and improved insulin sensitivity.

3. Hormonal adaptation: The body can adjust hormone levels in response to changes in the environment or internal conditions. For instance, during prolonged fasting, the body releases stress hormones like cortisol and adrenaline to help maintain energy levels and prevent muscle wasting.

4. Sensory adaptation: Our senses can adapt to different stimuli over time. For example, when we enter a dark room after being in bright sunlight, it takes some time for our eyes to adjust to the new light level. This process is known as dark adaptation.

5. Aging-related adaptations: As we age, various physiological changes occur that help us adapt to the changing environment and maintain homeostasis. These include changes in body composition, immune function, and cognitive abilities.

Protein kinases are a group of enzymes that play a crucial role in many cellular processes by adding phosphate groups to other proteins, a process known as phosphorylation. This modification can activate or deactivate the target protein's function, thereby regulating various signaling pathways within the cell. Protein kinases are essential for numerous biological functions, including metabolism, signal transduction, cell cycle progression, and apoptosis (programmed cell death). Abnormal regulation of protein kinases has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Complementarity Determining Regions (CDRs) are the portions of an antibody that recognize and bind to a specific antigen. These regions are located in the variable domains of both the heavy and light chains of the antibody molecule. The CDRs are formed by the hypervariable loops within these domains, which have unique sequences that allow them to bind specifically to a particular epitope on an antigen. There are three CDRs in each variable domain, for a total of six CDRs per antibody. The CDRs are primarily responsible for the antigen-binding specificity and affinity of an antibody.

The aorta is the largest artery in the human body, which originates from the left ventricle of the heart and carries oxygenated blood to the rest of the body. It can be divided into several parts, including the ascending aorta, aortic arch, and descending aorta. The ascending aorta gives rise to the coronary arteries that supply blood to the heart muscle. The aortic arch gives rise to the brachiocephalic, left common carotid, and left subclavian arteries, which supply blood to the head, neck, and upper extremities. The descending aorta travels through the thorax and abdomen, giving rise to various intercostal, visceral, and renal arteries that supply blood to the chest wall, organs, and kidneys.

I apologize for the confusion, but "physical conditioning" is not a term that is typically used in the context of animals in veterinary medicine or animal sciences. The term "physical conditioning" is more commonly used to describe the process of improving an individual's physical fitness through exercise and training.

However, in animal science, the concept of "training" or "exercising" animals may refer to the process of teaching them specific behaviors or skills, improving their physical abilities, or promoting their overall health and well-being. This might involve activities such as providing opportunities for regular exercise, engaging in play, or using positive reinforcement techniques to teach animals new skills or modify their behavior.

If you have any further questions about animal care or training, I would be happy to try to help!

"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.

Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.

Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.

Succinate dehydrogenase (SDH) is an enzyme complex that plays a crucial role in the process of cellular respiration, specifically in the citric acid cycle (also known as the Krebs cycle) and the electron transport chain. It is located in the inner mitochondrial membrane of eukaryotic cells.

SDH catalyzes the oxidation of succinate to fumarate, converting it into a molecule of fadaquate in the process. During this reaction, two electrons are transferred from succinate to the FAD cofactor within the SDH enzyme complex, reducing it to FADH2. These electrons are then passed on to ubiquinone (CoQ), which is a mobile electron carrier in the electron transport chain, leading to the generation of ATP, the main energy currency of the cell.

SDH is also known as mitochondrial complex II because it is the second complex in the electron transport chain. Mutations in the genes encoding SDH subunits or associated proteins have been linked to various human diseases, including hereditary paragangliomas, pheochromocytomas, gastrointestinal stromal tumors (GISTs), and some forms of neurodegenerative disorders.

Immunoglobulin G (IgG) is a type of antibody, which is a protective protein produced by the immune system in response to foreign substances like bacteria or viruses. IgG is the most abundant type of antibody in human blood, making up about 75-80% of all antibodies. It is found in all body fluids and plays a crucial role in fighting infections caused by bacteria, viruses, and toxins.

IgG has several important functions:

1. Neutralization: IgG can bind to the surface of bacteria or viruses, preventing them from attaching to and infecting human cells.
2. Opsonization: IgG coats the surface of pathogens, making them more recognizable and easier for immune cells like neutrophils and macrophages to phagocytose (engulf and destroy) them.
3. Complement activation: IgG can activate the complement system, a group of proteins that work together to help eliminate pathogens from the body. Activation of the complement system leads to the formation of the membrane attack complex, which creates holes in the cell membranes of bacteria, leading to their lysis (destruction).
4. Antibody-dependent cellular cytotoxicity (ADCC): IgG can bind to immune cells like natural killer (NK) cells and trigger them to release substances that cause target cells (such as virus-infected or cancerous cells) to undergo apoptosis (programmed cell death).
5. Immune complex formation: IgG can form immune complexes with antigens, which can then be removed from the body through various mechanisms, such as phagocytosis by immune cells or excretion in urine.

IgG is a critical component of adaptive immunity and provides long-lasting protection against reinfection with many pathogens. It has four subclasses (IgG1, IgG2, IgG3, and IgG4) that differ in their structure, function, and distribution in the body.

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

Phosphotransferases are a group of enzymes that catalyze the transfer of a phosphate group from a donor molecule to an acceptor molecule. This reaction is essential for various cellular processes, including energy metabolism, signal transduction, and biosynthesis.

The systematic name for this group of enzymes is phosphotransferase, which is derived from the general reaction they catalyze: D-donor + A-acceptor = D-donor minus phosphate + A-phosphate. The donor molecule can be a variety of compounds, such as ATP or a phosphorylated protein, while the acceptor molecule is typically a compound that becomes phosphorylated during the reaction.

Phosphotransferases are classified into several subgroups based on the type of donor and acceptor molecules they act upon. For example, kinases are a subgroup of phosphotransferases that transfer a phosphate group from ATP to a protein or other organic compound. Phosphatases, another subgroup, remove phosphate groups from molecules by transferring them to water.

Overall, phosphotransferases play a critical role in regulating many cellular functions and are important targets for drug development in various diseases, including cancer and neurological disorders.

A hybridoma is a type of hybrid cell that is created in a laboratory by fusing a cancer cell (usually a B cell) with a normal immune cell. The resulting hybrid cell combines the ability of the cancer cell to grow and divide indefinitely with the ability of the immune cell to produce antibodies, which are proteins that help the body fight infection.

Hybridomas are commonly used to produce monoclonal antibodies, which are identical copies of a single antibody produced by a single clone of cells. These antibodies can be used for a variety of purposes, including diagnostic tests and treatments for diseases such as cancer and autoimmune disorders.

To create hybridomas, B cells are first isolated from the spleen or blood of an animal that has been immunized with a specific antigen (a substance that triggers an immune response). The B cells are then fused with cancer cells using a chemical agent such as polyethylene glycol. The resulting hybrid cells are called hybridomas and are grown in culture medium, where they can be selected for their ability to produce antibodies specific to the antigen of interest. These antibody-producing hybridomas can then be cloned to produce large quantities of monoclonal antibodies.

Myogenic Regulatory Factor 5 (MRF5) is a protein that belongs to the family of muscle regulatory factors. It is a transcription factor, which means it regulates the expression of genes, specifically those involved in muscle development and differentiation. MRF5 plays a crucial role in skeletal muscle formation during embryonic development and also contributes to the maintenance and repair of skeletal muscles in adults.

MRF5 is expressed in developing muscle cells, where it helps to activate genes required for muscle-specific functions and represses genes associated with other cell fates. In addition, MRF5 has been implicated in the regulation of muscle stem cell (satellite cell) function and may play a role in the adaptation of skeletal muscles to various stimuli, such as exercise or injury.

Defects in MRF5 have been linked to certain muscular disorders, highlighting its importance in maintaining proper muscle function.

An oligonucleotide probe is a short, single-stranded DNA or RNA molecule that contains a specific sequence of nucleotides designed to hybridize with a complementary sequence in a target nucleic acid (DNA or RNA). These probes are typically 15-50 nucleotides long and are used in various molecular biology techniques, such as polymerase chain reaction (PCR), DNA sequencing, microarray analysis, and blotting methods.

Oligonucleotide probes can be labeled with various reporter molecules, like fluorescent dyes or radioactive isotopes, to enable the detection of hybridized targets. The high specificity of oligonucleotide probes allows for the precise identification and quantification of target nucleic acids in complex biological samples, making them valuable tools in diagnostic, research, and forensic applications.

Osmolar concentration is a measure of the total number of solute particles (such as ions or molecules) dissolved in a solution per liter of solvent (usually water), which affects the osmotic pressure. It is expressed in units of osmoles per liter (osmol/L). Osmolarity and osmolality are related concepts, with osmolarity referring to the number of osmoles per unit volume of solution, typically measured in liters, while osmolality refers to the number of osmoles per kilogram of solvent. In clinical contexts, osmolar concentration is often used to describe the solute concentration of bodily fluids such as blood or urine.

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

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

Protein transport, in the context of cellular biology, refers to the process by which proteins are actively moved from one location to another within or between cells. This is a crucial mechanism for maintaining proper cell function and regulation.

Intracellular protein transport involves the movement of proteins within a single cell. Proteins can be transported across membranes (such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, or plasma membrane) via specialized transport systems like vesicles and transport channels.

Intercellular protein transport refers to the movement of proteins from one cell to another, often facilitated by exocytosis (release of proteins in vesicles) and endocytosis (uptake of extracellular substances via membrane-bound vesicles). This is essential for communication between cells, immune response, and other physiological processes.

It's important to note that any disruption in protein transport can lead to various diseases, including neurological disorders, cancer, and metabolic conditions.

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

Here is a brief medical definition:

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

'Gene rearrangement in B-lymphocytes, light chain' refers to the biological process that occurs during the development of B-lymphocytes (a type of white blood cell) in the bone marrow. Specifically, it relates to the rearrangement of genes that code for the light chains of immunoglobulins, which are antibodies that help the immune system recognize and fight off foreign substances.

During gene rearrangement, the variable region genes of the light chain locus (which consist of multiple gene segments, including V, D, and J segments) undergo a series of DNA recombination events to form a functional variable region exon. This process allows for the generation of a vast diversity of antibody molecules with different specificities, enabling the immune system to recognize and respond to a wide range of potential threats.

Abnormalities in this gene rearrangement process can lead to various immunodeficiency disorders or malignancies such as B-cell lymphomas.

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.

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

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

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

1. Receptors: In the context of physiology and medicine, receptors are specialized proteins found on the surface of cells or inside cells that detect and respond to specific molecules, known as ligands. These interactions can trigger a variety of responses within the cell, such as starting a signaling cascade or changing the cell's metabolism. Receptors play crucial roles in various biological processes, including communication between cells, regulation of immune responses, and perception of senses.

2. Antigen: An antigen is any substance (usually a protein) that can be recognized by the adaptive immune system, specifically by B-cells and T-cells. Antigens can be derived from various sources, such as microorganisms (like bacteria, viruses, or fungi), pollen, dust mites, or even components of our own cells (for instance, in autoimmune diseases). An antigen's ability to stimulate an immune response is determined by its molecular structure and whether it can be recognized by the receptors on immune cells.

3. B-Cell: B-cells are a type of white blood cell that plays a critical role in the adaptive immune system, particularly in humoral immunity. They originate from hematopoietic stem cells in the bone marrow and are responsible for producing antibodies, which are proteins that recognize and bind to specific antigens. Each B-cell has receptors on its surface called B-cell receptors (BCRs) that can recognize a unique antigen. When a B-cell encounters its specific antigen, it becomes activated, undergoes proliferation, and differentiates into plasma cells that secrete large amounts of antibodies to neutralize or eliminate the antigen.

Muscle strength, in a medical context, refers to the amount of force a muscle or group of muscles can produce during contraction. It is the maximum amount of force that a muscle can generate through its full range of motion and is often measured in units of force such as pounds or newtons. Muscle strength is an important component of physical function and mobility, and it can be assessed through various tests, including manual muscle testing, dynamometry, and isokinetic testing. Factors that can affect muscle strength include age, sex, body composition, injury, disease, and physical activity level.

Temperature, in a medical context, is a measure of the degree of hotness or coldness of a body or environment. It is usually measured using a thermometer and reported in degrees Celsius (°C), degrees Fahrenheit (°F), or kelvin (K). In the human body, normal core temperature ranges from about 36.5-37.5°C (97.7-99.5°F) when measured rectally, and can vary slightly depending on factors such as time of day, physical activity, and menstrual cycle. Elevated body temperature is a common sign of infection or inflammation, while abnormally low body temperature can indicate hypothermia or other medical conditions.

Cell size refers to the volume or spatial dimensions of a cell, which can vary widely depending on the type and function of the cell. In general, eukaryotic cells (cells with a true nucleus) tend to be larger than prokaryotic cells (cells without a true nucleus). The size of a cell is determined by various factors such as genetic makeup, the cell's role in the organism, and its environment.

The study of cell size and its relationship to cell function is an active area of research in biology, with implications for our understanding of cellular processes, evolution, and disease. For example, changes in cell size have been linked to various pathological conditions, including cancer and neurodegenerative disorders. Therefore, measuring and analyzing cell size can provide valuable insights into the health and function of cells and tissues.

Cross-linking reagents are chemical agents that are used to create covalent bonds between two or more molecules, creating a network of interconnected molecules known as a cross-linked structure. In the context of medical and biological research, cross-linking reagents are often used to stabilize protein structures, study protein-protein interactions, and develop therapeutic agents.

Cross-linking reagents work by reacting with functional groups on adjacent molecules, such as amino groups (-NH2) or sulfhydryl groups (-SH), to form a covalent bond between them. This can help to stabilize protein structures and prevent them from unfolding or aggregating.

There are many different types of cross-linking reagents, each with its own specificity and reactivity. Some common examples include glutaraldehyde, formaldehyde, disuccinimidyl suberate (DSS), and bis(sulfosuccinimidyl) suberate (BS3). The choice of cross-linking reagent depends on the specific application and the properties of the molecules being cross-linked.

It is important to note that cross-linking reagents can also have unintended effects, such as modifying or disrupting the function of the proteins they are intended to stabilize. Therefore, it is essential to use them carefully and with appropriate controls to ensure accurate and reliable results.

Immunoglobulin M (IgM) is a type of antibody that is primarily found in the blood and lymph fluid. It is the first antibody to be produced in response to an initial exposure to an antigen, making it an important part of the body's primary immune response. IgM antibodies are large molecules that are composed of five basic units, giving them a pentameric structure. They are primarily found on the surface of B cells as membrane-bound immunoglobulins (mlgM), where they function as receptors for antigens. Once an mlgM receptor binds to an antigen, it triggers the activation and differentiation of the B cell into a plasma cell that produces and secretes large amounts of soluble IgM antibodies.

IgM antibodies are particularly effective at agglutination (clumping) and complement activation, which makes them important in the early stages of an immune response to help clear pathogens from the bloodstream. However, they are not as stable or long-lived as other types of antibodies, such as IgG, and their levels tend to decline after the initial immune response has occurred.

In summary, Immunoglobulin M (IgM) is a type of antibody that plays a crucial role in the primary immune response to antigens by agglutination and complement activation. It is primarily found in the blood and lymph fluid, and it is produced by B cells after they are activated by an antigen.

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

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

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

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

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

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

A sequence deletion in a genetic context refers to the removal or absence of one or more nucleotides (the building blocks of DNA or RNA) from a specific region in a DNA or RNA molecule. This type of mutation can lead to the loss of genetic information, potentially resulting in changes in the function or expression of a gene. If the deletion involves a critical portion of the gene, it can cause diseases, depending on the role of that gene in the body. The size of the deleted sequence can vary, ranging from a single nucleotide to a large segment of DNA.

Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by the immune system's B cells in response to the presence of foreign substances, such as bacteria, viruses, and toxins. These Y-shaped proteins play a crucial role in identifying and neutralizing pathogens and other antigens, thereby protecting the body against infection and disease.

Immunoglobulins are composed of four polypeptide chains: two identical heavy chains and two identical light chains, held together by disulfide bonds. The variable regions of these chains form the antigen-binding sites, which recognize and bind to specific epitopes on antigens. Based on their heavy chain type, immunoglobulins are classified into five main isotypes or classes: IgA, IgD, IgE, IgG, and IgM. Each class has distinct functions in the immune response, such as providing protection in different body fluids and tissues, mediating hypersensitivity reactions, and aiding in the development of immunological memory.

In medical settings, immunoglobulins can be administered therapeutically to provide passive immunity against certain diseases or to treat immune deficiencies, autoimmune disorders, and other conditions that may benefit from immunomodulation.

Two-dimensional (2D) gel electrophoresis is a type of electrophoretic technique used in the separation and analysis of complex protein mixtures. This method combines two types of electrophoresis – isoelectric focusing (IEF) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) – to separate proteins based on their unique physical and chemical properties in two dimensions.

In the first dimension, IEF separates proteins according to their isoelectric points (pI), which is the pH at which a protein carries no net electrical charge. The proteins are focused into narrow zones along a pH gradient established within a gel strip. In the second dimension, SDS-PAGE separates the proteins based on their molecular weights by applying an electric field perpendicular to the first dimension.

The separated proteins form distinct spots on the 2D gel, which can be visualized using various staining techniques. The resulting protein pattern provides valuable information about the composition and modifications of the protein mixture, enabling researchers to identify and compare different proteins in various samples. Two-dimensional gel electrophoresis is widely used in proteomics research, biomarker discovery, and quality control in protein production.

Leucine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through the diet. It is one of the three branched-chain amino acids (BCAAs), along with isoleucine and valine. Leucine is critical for protein synthesis and muscle growth, and it helps to regulate blood sugar levels, promote wound healing, and produce growth hormones.

Leucine is found in various food sources such as meat, dairy products, eggs, and certain plant-based proteins like soy and beans. It is also available as a dietary supplement for those looking to increase their intake for athletic performance or muscle recovery purposes. However, it's important to consult with a healthcare professional before starting any new supplement regimen.

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.

Thyroid hormones are hormones produced and released by the thyroid gland, a small endocrine gland located in the neck that helps regulate metabolism, growth, and development in the human body. The two main thyroid hormones are triiodothyronine (T3) and thyroxine (T4), which contain iodine atoms. These hormones play a crucial role in various bodily functions, including heart rate, body temperature, digestion, and brain development. They help regulate the rate at which your body uses energy, affects how sensitive your body is to other hormones, and plays a vital role in the development and differentiation of all cells of the human body. Thyroid hormone levels are regulated by the hypothalamus and pituitary gland through a feedback mechanism that helps maintain proper balance.

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

RNA probes are specialized biomolecules used in molecular biology to detect and localize specific RNA sequences within cells or tissues. They are typically single-stranded RNA molecules that have been synthesized with a modified nucleotide, such as digoxigenin or biotin, which can be detected using antibodies or streptavidin conjugates.

RNA probes are used in techniques such as in situ hybridization (ISH) and Northern blotting to identify the spatial distribution of RNA transcripts within cells or tissues, or to quantify the amount of specific RNA present in a sample. The probe is designed to be complementary to the target RNA sequence, allowing it to bind specifically to its target through base-pairing interactions.

RNA probes can be labeled with various reporter molecules, such as radioactive isotopes or fluorescent dyes, which enable their detection and visualization using techniques such as autoradiography or microscopy. The use of RNA probes has proven to be a valuable tool in the study of gene expression, regulation, and localization in various biological systems.

A DNA probe is a single-stranded DNA molecule that contains a specific sequence of nucleotides, and is labeled with a detectable marker such as a radioisotope or a fluorescent dye. It is used in molecular biology to identify and locate a complementary sequence within a sample of DNA. The probe hybridizes (forms a stable double-stranded structure) with its complementary sequence through base pairing, allowing for the detection and analysis of the target DNA. This technique is widely used in various applications such as genetic testing, diagnosis of infectious diseases, and forensic science.

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

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

A multigene family is a group of genetically related genes that share a common ancestry and have similar sequences or structures. These genes are arranged in clusters on a chromosome and often encode proteins with similar functions. They can arise through various mechanisms, including gene duplication, recombination, and transposition. Multigene families play crucial roles in many biological processes, such as development, immunity, and metabolism. Examples of multigene families include the globin genes involved in oxygen transport, the immune system's major histocompatibility complex (MHC) genes, and the cytochrome P450 genes associated with drug metabolism.

... myosin heavy chain kinase MHCK MIHC kinase myosin heavy chain kinase myosin I heavy-chain kinase myosin II heavy-chain kinase [ ... myosin heavy-chain] phosphate Thus, the two substrates of this enzyme are ATP and myosin heavy-chain, whereas its two products ... a myosin-heavy-chain kinase (EC 2.7.11.7) is an enzyme that catalyzes the chemical reaction ATP + [myosin heavy-chain] ⇌ {\ ... kinase myosin heavy chain kinase A STK6. Cote GP, Bukiejko U (1987). "Purification and characterization of a myosin heavy chain ...
MLCs are structurally and functionally distinct from myosin heavy chains (MHCs). Nevertheless, the association of MLCs with the ... A myosin light chain is a light chain (small polypeptide subunit) of myosin. Myosin light chains were discovered by Chinese ... Myosin light-chain kinase Myosin-light-chain phosphatase Myosin+Light+Chains at the U.S. National Library of Medicine Medical ... Structurally, myosin light chains belong to the EF-hand family, a large family of Ca2+- binding proteins. MLCs contain two Ca2+ ...
Myosin is composed of two heavy chains, two nonphosphorylatable alkali light chains, and two phosphorylatable regulatory light ... Myosin light chain 5 is a protein that, in humans, is encoded by the MYL5 gene. This gene encodes one of the myosin light ... "Entrez Gene: Myosin light chain 5". Retrieved 2017-01-24. This article incorporates text from the United States National ... This gene product, one of the regulatory light chains, is expressed in fetal muscle and in adult retina, cerebellum, and basal ...
Myosin exists as a hexamer of two heavy chains, two alkali light chains, and two regulatory light chains. The heavy chain can ... There are many cell-specific isoforms of myosin heavy chains, coded for by a multi-gene family. Myosin interacts with actin to ... "Human embryonic myosin heavy chain cDNA. Interspecies sequence conservation of the myosin rod, chromosomal locus and isoform ... Hayashida M, Maita T, Matsuda G (July 1991). "The primary structure of skeletal muscle myosin heavy chain: I. Sequence of the ...
"Entrez Gene: MYH14 myosin, heavy chain 14". Chen AH, Ni L, Fukushima K, et al. (1995). "Linkage of a gene for dominant non- ... 2002). "Evolutionary implications of three novel members of the human sarcomeric myosin heavy chain gene family". Mol. Biol. ... "Nonmuscle Myosin Heavy-Chain Gene MYH14 Is Expressed in Cochlea and Mutated in Patients Affected by Autosomal Dominant Hearing ... "A novel myosin heavy chain gene in human chromosome 19q13.3". Gene. 312: 165-71. doi:10.1016/S0378-1119(03)00613-9. PMID ...
Myosin heavy chains are encoded by a multigene family. In mammals, at least ten different myosin heavy chain (MYH) isoforms ... Myosin-1, also known as 'striated muscle myosin heavy chain 1', is a protein that in humans is encoded by the MYH1 gene. This ... Class II Myosins are hexameric proteins composed of a pair of myosin heavy chains (MYH) and two pairs of nonidentical light ... "Entrez Gene: MYH1 myosin, heavy chain 1, skeletal muscle, adult". Yoon SJ, Seiler SH, Kucherlapati R, Leinwand L (December 1992 ...
... is a smooth muscle myosin belonging to the myosin heavy chain family. Myosin-11 is a subunit of a hexameric protein ... Chicken Myosin-11) at the PDBe-KB. Babu GJ, Warshaw DM, Periasamy M (2000). "Smooth muscle myosin heavy chain isoforms and ... 1994). "Smooth muscle myosin heavy chain locus (MYH11) maps to 16p13.13-p13.12 and establishes a new region of conserved ... 2006). "Mutations in myosin heavy chain 11 cause a syndrome associating thoracic aortic aneurysm/aortic dissection and patent ...
"Myosin heavy chain pattern in the Akhal-Teke horses." animal 5.5 (2010): 658. VIDEO: Amazing equine trek from Ashkhabad to ... The main reason for this are allegations of a heavy infusion of Thoroughbred blood into the breed to create faster horses for ...
This recruitment leads to the repression of the MLC2v (Myosin Light Chain 2 v) and βMHC ( β-myosin heavy chain ) promoter. ... Rindt H, Gulick J, Knotts S, Neumann J, Robbins J (March 1993). "In vivo analysis of the murine beta-myosin heavy chain gene ... Once this complex is formed, these two proteins can regulate the alpha-myosin heavy chain (α-MHC) gene expression. The four ... Gupta MP, Gupta M, Dizon E, Zak R (1996). "Sympathetic control of cardiac myosin heavy chain gene expression". Molecular and ...
Myosin-15 also known as myosin, heavy chain 15 is a protein that in humans is encoded by the MYH15 gene. MYH15 is a slow-twitch ... McGuigan K, Phillips PC, Postlethwait JH (2004). "Evolution of sarcomeric myosin heavy chain genes: evidence from fish". Mol. ... "Evolutionary implications of three novel members of the human sarcomeric myosin heavy chain gene family". Mol. Biol. Evol. 19 ( ... 2004). "Myosin gene mutation correlates with anatomical changes in the human lineage". Nature. 428 (6981): 415-8. Bibcode: ...
"Entrez Gene: MYH8 myosin, heavy chain 8, skeletal muscle, perinatal". Bober E, Buchberger-Seidl A, Braun T, et al. (1990). " ... Karsch-Mizrachi I, Feghali R, Shows TB, Leinwand LA (Aug 1990). "Generation of a full-length human perinatal myosin heavy-chain ... Soussi-Yanicostas N, Whalen RG, Petit C (1993). "Five skeletal myosin heavy chain genes are organized as a multigene complex in ... 2004). "Mutation of perinatal myosin heavy chain associated with a Carney complex variant". N. Engl. J. Med. 351 (5): 460-9. ...
Myosin is a hexameric protein composed of a pair of myosin heavy chains (MYH) and two pairs of nonidentical light chains. This ... "Human embryonic myosin heavy chain cDNA. Interspecies sequence conservation of the myosin rod, chromosomal locus and isoform ... "Entrez Gene: MYH3 myosin, heavy chain 3, skeletal muscle, embryonic". Alvarado DM, Buchan JG, Gurnett CA, Dobbs MB (Jun 2011 ... Hundley AF, Yuan L, Visco AG (May 2006). "Skeletal muscle heavy-chain polypeptide 3 and myosin binding protein H in the ...
Myosin-7B also known as myosin, heavy chain 7B is a protein that in humans is encoded by the MYH7B gene. MYH7B is a slow-twitch ... McGuigan K, Phillips PC, Postlethwait JH (2004). "Evolution of sarcomeric myosin heavy chain genes: evidence from fish". Mol. ... "Evolutionary implications of three novel members of the human sarcomeric myosin heavy chain gene family". Mol. Biol. Evol. 19 ( ... 2010). "Two novel/ancient myosins in mammalian skeletal muscles: MYH14/7b and MYH15 are expressed in extraocular muscles and ...
"MYH9 myosin heavy chain 9 [Homo sapiens (Human)] - Gene - NCBI". Zhang L, Li C, Su X (December 2020). "Emerging impact of the ... collagen type I alpha 1 chain), COL1A2 (collagen type I alpha 2 chain), COL3A1 (collagen type III alpha 1 chain), PAFAH1B1 ( ... myosin regulatory light chain 12A) gene. While very few cases have been analyzed to date, USP6-containing fusion genes have ... Its most common partner gene in NF is the MYH9 (myosin-9) gene. This USP6-MYH9 fusion gene forms as a result of a translocation ...
... (myosin heavy chain 2) is a protein that in humans is encoded by the MYH2 gene. GRCh38: Ensembl release 89: ... "Entrez Gene: MYH2 myosin, heavy chain 2, skeletal muscle, adult". Schwartz CE, McNally E, Leinwand L, Skolnick MH (1987). "A ... 2002). "Myosin heavy chain IIa gene mutation E706K is pathogenic and its expression increases with age". Neurology. 58 (5): 780 ... Chung MC, Kawamoto S (2005). "IRF-2 is involved in up-regulation of nonmuscle myosin heavy chain II-A gene expression during ...
Toydemir RM, Rutherford A, Whitby FG, Jorde LB, Carey JC, Bamshad MJ (2006). "Mutations in embryonic myosin heavy chain (MYH3) ... 2006) showed that mutations in embryonic myosin heavy chain 3 (MYH3; MIM *160270), at 17p-13.1-pter, caused classic FSS ... Online Mendelian Inheritance in Man (OMIM): MYOSIN, HEAVY CHAIN 3, SKELETAL MUSCLE, EMBRYONIC; MYH3 - 160720 b .0001 c .0002 d ... an embryonic myosin residue retained post-embryonically. Of the remaining 6 patients in whom they found mutations, 3 had ...
Giger, JM; Haddad, F; Qin, AX; Zeng, M; Baldwin, KM (April 2005). "Effect of unloading on type I myosin heavy chain gene ... Also, transformations in the myosin heavy chain profile indicated that there was a greater level of hybrid slow/fast fibers in ... Zhou, MY; Klitgaard, H; Saltin, B; Roy, RR; Edgerton, VR; Gollnick, PD (May 1995). "Myosin heavy chain isoforms of human muscle ... Pandorf, CE; Haddad, F; Roy, RR; Qin, AX; Edgerton, VR; Baldwin, KM (15 December 2006). "Dynamics of myosin heavy chain gene ...
"Noninvasive estimation of myosin heavy chain composition in human skeletal muscle." Med. Sci. Sports Exerc 43.9 (2011): 1619- ... heavy chain myosin amount20) and muscle status/condition (e.g.,fatigue, potentiation, inhibition, stress influence on the body ... Application of tensiomyography method identifies muscle pair asymmetry and asynchronous action in the kinetic chain, which ...
1998). "Control of AMP deaminase 1 binding to myosin heavy chain". Am. J. Physiol. 275 (3 Pt 1): C870-81. doi:10.1152/ajpcell. ...
Implications in the repression of alpha-myosin heavy chain during heart failure". J. Biol. Chem. 278 (45): 44935-48. doi: ... DNA-binding proteins PURalpha and PURbeta bind to a purine-rich negative regulatory element of the alpha-myosin heavy chain ...
Implications in the repression of alpha-myosin heavy chain during heart failure". J. Biol. Chem. 278 (45): 44935-48. doi: ... DNA-binding proteins PURalpha and PURbeta bind to a purine-rich negative regulatory element of the alpha-myosin heavy chain ...
Myosin Heavy Chain (MHC) Myosin Light Chain - alkali (MLC1) Myosin Light Chain - regulatory (MLC2) The Immunohistochemical ... Caiozzo VJ, Baker MJ, Huang K, Chou H, Wu YZ, Baldwin KM (September 2003). "Single-fiber myosin heavy chain polymorphism: how ... Baldwin KM, Haddad F (January 2001). "Effects of different activity and inactivity paradigms on myosin heavy chain gene ... Low(er) myosin ATPase, sensitive to alkali. IIa (Fast oxidative/glycolytic, FOG) - High glycolytic, oxidative and myosin ATPase ...
The myosin heavy chain isotype is a major determinant of the specific fiber type. In zebrafish embryos, the first muscle fibers ... Between the tenth and the eighteenth weeks of gestation, all muscle cells have fast myosin heavy chains; two myotube types ... "Expression of multiple slow myosin heavy chain genes reveals a diversity of zebrafish slow twitch muscle fibres with differing ... Sokoloff, Alan J.; Li, Haiyan; Burkholder, Thomas J. (August 2007). "Limited expression of slow tonic myosin heavy chain in ...
... is directly involved in smooth muscle myosin heavy chain (SMHC) gene regulation. Overexpression of MEF2B will activate ... a component of a smooth muscle-specific complex that binds an A/T-rich element important for smooth muscle myosin heavy chain ... a component of a smooth muscle-specific complex that binds an A/T-rich element important for smooth muscle myosin heavy chain ...
Myosin heavy chain This disambiguation page lists articles associated with the title MYH. If an internal link led you here, you ...
Myosin-9 also known as myosin, heavy chain 9, non-muscle or non-muscle myosin heavy chain IIa (NMMHC-IIA) is a protein which in ... Class II myosins include muscle and non-muscle myosins that are organized as hexameric molecules consisting of two heavy chains ... April 2010). "Heavy chain myosin 9-related disease (MYH9 -RD): neutrophil inclusions of myosin-9 as a pathognomonic sign of the ... controlling the myosin activity, and two essential light chains (17 kDa), which stabilize the heavy chain structure. MYH9 is a ...
Myosin II contains two heavy chains (MHC) which constitute the head and tail domains. Each of these heavy chains contains the N ... The myosin light chain phosphatase is inhibited to increase the gain or sensitivity of myosin light chain kinase to calcium. ... myosin II has two heads. In smooth muscle, there is a single gene (MYH11) that codes for the heavy chains myosin II, but there ... Different combinations of heavy and light chains allow for up to hundreds of different types of myosin structures, but it is ...
This is achieved by using a type of Cre whose expression is driven by the α {\displaystyle \alpha } -myosin heavy chain ... "Prolonged Cre expression driven by the α-myosin heavy chain promoter can be cardiotoxic". Journal of Molecular and Cellular ...
"Cloning and regional assignment of the human myosin heavy chain 12 (MYH12) gene to chromosome band 15q21". Cytogenetics and ... Rodriguez OC, Cheney RE (Mar 2002). "Human myosin-Vc is a novel class V myosin expressed in epithelial cells". Journal of Cell ... "Interaction of the postsynaptic density-95/guanylate kinase domain-associated protein complex with a light chain of myosin-V ... "Interaction of the postsynaptic density-95/guanylate kinase domain-associated protein complex with a light chain of myosin-V ...
Its major substrate is Myosin Heavy Chain (MHC, or Myosin-2, or MYH2), meaning it induces the proteasome-mediated degradatin of ... MuRF1 is upregulated during skeletal muscle atrophy - and thus the degradation of myosin heavy chain, which is a major ... This finding suggests that Myosin Heavy Chain levels may be dysregulated in the heart in the absence of MuRF1, leading to ... "The E3 Ligase MuRF1 degrades myosin heavy chain protein in dexamethasone-treated skeletal muscle". Cell Metabolism. 6 (5): 376- ...
... myosin heavy chain kinase MHCK MIHC kinase myosin heavy chain kinase myosin I heavy-chain kinase myosin II heavy-chain kinase [ ... myosin heavy-chain] phosphate Thus, the two substrates of this enzyme are ATP and myosin heavy-chain, whereas its two products ... a myosin-heavy-chain kinase (EC 2.7.11.7) is an enzyme that catalyzes the chemical reaction ATP + [myosin heavy-chain] ⇌ {\ ... kinase myosin heavy chain kinase A STK6. Cote GP, Bukiejko U (1987). "Purification and characterization of a myosin heavy chain ...
... and IGHJ3 with nearly identical heavy and light chain complementarity-determining region 3 sequences. Th … ... patients express an unmutated heavy chain immunoglobulin variable (V) region encoded by IGHV1-69, IGHD3-16, ... Chronic lymphocytic leukemia antibodies with a common stereotypic rearrangement recognize nonmuscle myosin heavy chain IIA ... a major protein band at approximately 225 kDa that was identified by mass spectrometry as nonmuscle myosin heavy chain IIA ( ...
Working capacity and expression of myosin heavy chain isoforms in skeletal muscle of chronic alcoholic men without liver ... After 4 weeks of alcohol abstinence a shift in the expression of myosin heavy chain type I towards myosin heavy chain type IIA ... the expression of myosin heavy chain isoforms in human skeletal muscle by decreasing the expression of myosin heavy chain type ... Wada, M.; Katsuta, S.; Doi, T.; Kuno, S. 1990: Favourable associations between the myosin heavy-chain and light-chain isoforms ...
This is a correction to: Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis ... Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis elegans muscles developed ... Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis elegans muscles developed ... Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis elegans muscles developed ...
Remarkable heterogeneity in myosin heavy-chain composition of the human young masseter compared with young biceps brachii Best ...
View Myosin heavy chain 11 Antibody (MYH11/923) [Alexa Fluor® 594] (NBP2-47900AF594) validated in 2 species & 6 applications ... Myosin heavy chain 11. The protein encoded by the MYH11 gene is a smooth muscle myosin belonging to the myosin heavy chain ... Additional Myosin heavy chain 11 Products. *All Products for Myosin heavy chain 11 ... AAT4, FAA4, MYH11, MYH11 myosin, heavy chain 11, smooth muscle, SMHC, SMMHC, Smooth muscle myosin heavy chain ...
mouse Myosin Heavy Chain Type I MYH7 antibody validated for Immunofluorescence,Immunohistochemistry,Western Blot ... Three myosin heavy chain isoforms in type 2 skeletal muscle fibres.. Lømo T Journal of muscle research and cell motility 10.3 ( ... Three myosin heavy chain isoforms in type 2 skeletal muscle fibres.. Lømo T Journal of muscle research and cell motility 10.3 ( ... Myosin heavy chain isoform and metabolic profile differ in beef steaks varying in tenderness.. Matarneh SK Meat science 170. ( ...
myosin-11. Names. epididymis secretory sperm binding protein. myosin, heavy chain 11, smooth muscle. myosin, heavy polypeptide ... MYH11 myosin heavy chain 11 [Homo sapiens] MYH11 myosin heavy chain 11 [Homo sapiens]. Gene ID:4629 ... MYSc_Myh11; class II myosin heavy chain 11, motor domain. pfam01576. Location:848 → 1928. Myosin_tail_1; Myosin tail. pfam02736 ... MYSc_Myh11; class II myosin heavy chain 11, motor domain. pfam00063. Location:87 → 771. Myosin_head; Myosin head (motor domain) ...
Absolute quantification of myosin heavy chain isoforms by selected reaction monitoring can underscore skeletal muscle changes ... Skeletal muscle fibers contain different isoforms of myosin heavy chain (MyHC) that define distinctive contractile properties. ... Skeletal muscle fibers contain different isoforms of myosin heavy chain (MyHC) that define distinctive contractile properties. ...
Myosin heavy chain and cardiac troponin T damage is associated with impaired myofibrillar ATPase activity contributing to ... Myosin heavy chain and cardiac troponin T damage is associated with impaired myofibrillar ATPase activity contributing to ...
HUMAN NONMUSCLE MYOSIN HEAVY-CHAIN MESSENGER-RNA - GENERATION OF DIVERSITY THROUGH ALTERNATIVE POLYADENYLYLATION Journal ...
... both α-myosin heavy chain (α-MHC, the faster contracting isoform, encoded by Myh6 gene) and β-myosin heavy chain (β-MHC, the ... Lompré AM, Nadal-Ginard B, Mahdavi V. Expression of the cardiac ventricular alpha- and beta-myosin heavy chain genes is ... A family of microRNAs encoded by myosin genes governs myosin expression and muscle performance. Dev Cell. 2009;17:662-73. ... Factors controlling cardiac myosin-isoform shift during hypertrophy and heart failure. J Mol Cell Cardiol. 2007;43:388-403. ...
... ; Synonyms: Anti-CPSFS1A,Anti-CPSFS1B,Anti-CPSKF1A,Anti- ... Myosin is a 480,000 dalton protein containing two identical heavy chains (200,000 daltons each) and four light chains (15,000- ... Multiple forms of myosin heavy chains exist for each muscle type; skeletal, cardiac, smooth and non-muscle isomyosin forms ... Anti-Myosin (Skeletal) antibody produced in rabbit has been used in:. *immunohistochemistry ...
MYH3: myosin heavy chain 3. *MYH6: myosin heavy chain 6. *MYH7: myosin heavy chain 7 ... MYH9: myosin heavy chain 9. *MYH11: myosin heavy chain 11. *MYO5A: myosin VA ...
MYH6+Slow Skeletal Myosin Heavy chain (2). * Myosin+Tau+MYH6+non-muscle heavy chain Myosin+TDP1+STK33+non-muscle Myosin IIA+ ...
myosin, heavy chain 9. ISO. DNA:missense mutation:exon:4270G>C,D1424H (human). RGD. PMID:12500226. RGD:6902925. NCBI chr 7: ... myosin, heavy chain 9. ISO. CTD Direct Evidence: marker/mechanism. CTD. PMID:10973259. NCBI chr 7:109,343,718...109,424,457 ... myosin XVA. ISO. ClinVar Annotator: match by term: Alport syndrome. ClinVar. PMID:28492532 PMID:30311386. NCBI chr10:45,277,619 ... collagen type IV alpha 6 chain. ISO. ClinVar Annotator: match by term: X-linked Alport syndrome. ClinVar. NCBI chr X: ...
Myosin heavy chain 11. 0.7721. 55. POU2F2. POU class 2 homeobox 2. 0.7634. 55. ...
Myosin Heavy Chains. *Myocardium. *Microscopy, Electron. *Microscopy, Confocal. *Laminin. *L-Lactate Dehydrogenase ...
PDB Description: Structure of nucleotide-free scallop myosin S1. PDB Compounds: (A:) myosin heavy chain, striated muscle. SCOPe ... Protein Myosin S1, motor domain [52642] (5 species). common fold is interrupted with some all-alpha subdomains. ... d1sr6a2 c.37.1.9 (A:6-28,A:77-837) Myosin S1, motor domain {Bay scallop (Aequipecten irradians) [TaxId: 31199]} ... d1sr6a2 c.37.1.9 (A:6-28,A:77-837) Myosin S1, motor domain {Bay scallop (Aequipecten irradians) [TaxId: 31199]} ...
D-dimer and smooth muscle myosin heavy chain (smMHC) have been the most studied. The protein smMHC is a major component of ... The smooth muscle myosin heavy chain study. Ann Intern Med 2000; 133:537-41. ... Results of a prospective study using an immunoassay of smooth muscle myosin heavy chain. Circulation 1996; 93:1244-9. ... Suzuki T, et al., Diagnostic implications of elevated levels of smooth-muscle myosin heavy-chain protein in acute aortic ...
Open this publication in new window or tab ,,Differential regulation of myosin heavy chains defines new muscle domains in ... extraocular muscles, myofiber, myosin heavy chain 7, obscurin, zebrafish National Category Ophthalmology Identifiers. urn:nbn: ... Loss of obscurin induces a myofiber type shift in the EOMs, with upregulation of cardiac myosin heavy chain, myh7, showing an ... In this study, we show that six fast muscle-specific myosin heavy chain genes have unique expression patterns in the zebrafish ...
RefSeq) myosin heavy chain 9. KO. K10352 myosin heavy chain 9/10/11/14. ... Myosin_tail_1 Myosin_head Myosin_N Crescentin ERM_helical CC2-LZ IQ ADIP ATG16 AAA_22. ... Myosin_tail_1 Myosin_head Myosin_N IQ ADIP CC2-LZ ERM_helical Crescentin AAA_22. ... Myosin_tail_1 Myosin_head Myosin_N ADIP IQ ERM_helical CC2-LZ AAA_22. ...
MiRNA-208a regulates systemic energy homeostasis and β-myosin heavy chain content via mediator complex subunit 13 (MED13) [44 ... For all polymerase chain reaction experiments, samples were run in triplicates.. 4.8. Statistical Analysis. Continuous ...
Methods: EAM was induced by immunizing BALB/c mice with cardiac α-myosin heavy chain peptides (MyHC-α). 1, 25(OH)2 D3 (1,000 ng ... Eight-week-old male BALB/c mice were subcutaneously injected with cardiac α-myosin heavy chain peptides (MyHC-α, sequence: ... Neu N, Beisel KW, Traystman MD, Rose NR, Craig SW: Autoantibodies specific for the cardiac myosin isoform are found in mice ... Neu N, Beisel KW, Traystman MD, Rose NR, Craig SW: Autoantibodies specific for the cardiac myosin isoform are found in mice ...
Myosin in the largest biology dictionary online. Free learning resources for students covering all major areas of biology. ... There is a single heavy chain of 119kD and multiple (3 or 4) calmodulin light chains. The heavy chain has a C terminal domain ... Other myosins are Myosin III, Myosin III, Myosin IV, Myosin V, Myosin VI, Myosin VII, Myosin VIII, Myosin IX, Myosin X, etc... ... and is more similar to sarcomeric myosin than to the nonsarcomeric myosins. Smooth muscle myosin has two 200 kD heavy chains, ...
Malalignment of the sarcomeric filaments in hypertrophic cardiomyopathy with cardiac myosin heavy chain gene mutation A ...
... and a nonmuscle myosin II all localize to the cortex o ... Depletion of the nonmuscle myosin II heavy chain (NMY)-2 or of ... myosin II regulatory light chain; MT, microtubule; NCC, nucleocentrosomal complex; NMY, nonmuscle myosin II heavy chain; PAR, ... myosin II regulatory light chain; MT, microtubule; NCC, nucleocentrosomal complex; NMY, nonmuscle myosin II heavy chain; PAR, ... The nonmuscle myosin regulatory light chain gene mlc-4 is required for cytokinesis, anterior-posterior polarity, and body ...
32 Klitgaard, H. et al. Ageing alters the myosin heavy chain composition of single fibres from human skeletal muscle. Acta ... Studies have shown that older individuals have reduced expression of mitochondrial respiratory chain complexes and reduced ...
  • 1. The aim of this study was to examine the effect of chronic alcohol ingestion on working capacity and on the expression of myosin heavy chain isoforms in fibre types of human skeletal muscle. (eurekamag.com)
  • 4. The relative proportion of fibres expressing only myosin heavy chain type IIB isoforms was one-third of normal in the alcoholic patients at both tests 1 and 2. (eurekamag.com)
  • The relative proportion of fibres expressing only myosin heavy chain type IIA isoforms was the same in alcoholic patients at test 1 and in normal control subjects, but increased by 25% between test 1 and 2 in the alcoholic group. (eurekamag.com)
  • 5. The relative proportion of fibres showing coexpression of myosin heavy chain type IIA/IIB isoforms was about two-thirds of normal in alcoholic patients at both test 1 and test 2, whereas fibres with co-expression of myosin heavy chain type I/IIA were not seen in the control group, but were found in the alcoholic group, where they doubled from test 1 to test 2. (eurekamag.com)
  • Two isoforms of smooth muscle myosin heavy chain have been identified, designated MHC-1 and MHC-2. (bio-techne.com)
  • Three myosin heavy chain isoforms in type 2 skeletal muscle fibres. (uiowa.edu)
  • Skeletal muscle fibers contain different isoforms of myosin heavy chain (MyHC) that define distinctive contractile properties. (unipd.it)
  • Therefore, HEp-2 cell extracts were immunoprecipitated with recombinant stereotypic subset-specific CLL mAbs, revealing a major protein band at approximately 225 kDa that was identified by mass spectrometry as nonmuscle myosin heavy chain IIA (MYHIIA). (nih.gov)
  • In Caenorhabditis elegans , the partitioning proteins (PARs), microfilaments (MFs), dynein, dynactin, and a nonmuscle myosin II all localize to the cortex of early embryonic cells. (rupress.org)
  • The head of the myosin is that part that binds with actin. (biologyonline.com)
  • The sarcomeres contain a number of proteins, including alpha actinin, which is the major constituent of the Z band, and actin and myosin, which are the major components of the thin and thick filaments, respectively. (medscape.com)
  • Expression of smooth muscle myosin is developmentally regulated, appearing early in smooth muscle development, and is specific for smooth muscle development. (bio-techne.com)
  • whole myosin (heavy and light chains) from human skeletal muscle. (sigmaaldrich.com)
  • Studies have shown that older individuals have reduced expression of mitochondrial respiratory chain complexes and reduced aerobic respiration in skeletal muscle 3,4 . (researchsquare.com)
  • It is the classical sarcomeric myosin that self assembles into bipolar thick filaments. (biologyonline.com)
  • There are two heavy chains (up to 240 kD) and two pairs of light chains (15-20 kD), the self-assembled filaments are shorter than those of the sarcomere . (biologyonline.com)
  • Smooth muscle myosin heavy chain (SM-MHC) is a cytoplasmic structural protein, which is a major component of the contractile apparatus in smooth muscle cells. (bio-techne.com)
  • The protein encoded by the MYH11 gene is a smooth muscle myosin belonging to the myosin heavy chain family. (bio-techne.com)
  • The gene product is a subunit of a hexameric protein that consists of two heavy chain subunits and two pairs of non-identical light chain subunits. (bio-techne.com)
  • The pericentric inversion of chromosome 16 [inv(16)(p13q22)] produces a chimeric transcript that encodes a protein consisting of the first 165 residues from the N terminus of core-binding factor beta in a fusion with the C-terminal portion of the smooth muscle myosin heavy chain. (bio-techne.com)
  • Myosin is a 480,000 dalton protein containing two identical heavy chains (200,000 daltons each) and four light chains (15,000-26,000 daltons). (sigmaaldrich.com)
  • Immunohistochemistry, in-situ hybridization, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) techniques were used to evaluate the presence of desmin protein and its mRNA. (diva-portal.org)
  • Myosin I is an ubiquitous motor protein. (biologyonline.com)
  • Myosin II is a multimeric protein (440 kD) with two heavy chains (200 kD) and two pairs of light chains (17-22 kD) in each hexamer . (biologyonline.com)
  • MYO2 may be similar to dilute myosin from mouse and p190 protein from vertebrate brain. (biologyonline.com)
  • Myosins belong to a family of motor proteins in muscle s to enable muscle contraction . (biologyonline.com)
  • Cytoplasmic myosin II is a family of sarcomeric myosin like proteins, also hexameric, responsible for force generation by interaction with microfilament s. (biologyonline.com)
  • Smooth muscle myosin has two 200 kD heavy chains, two regulatory 20 kD light chains that can be phosphorylated, altering its binding to the heavy chains which induces a conformational change that renders the myosin active and two 17 kD light chains. (biologyonline.com)
  • Scallop myosin is directly calcium regulated (through regulatory and essential light chains) and is more similar to sarcomeric myosin than to the nonsarcomeric myosins. (biologyonline.com)
  • The tail domain interacts with the other molecules and/or other myosin subunits. (biologyonline.com)
  • Other names in common use include ATP:myosin-heavy-chain O-phosphotransferase calmodulin-dependent myosin heavy chain kinase MHCK MIHC kinase myosin heavy chain kinase myosin I heavy-chain kinase myosin II heavy-chain kinase [myosin-heavy-chain] kinase myosin heavy chain kinase A STK6. (wikipedia.org)
  • There is a single heavy chain of 119kD and multiple (3 or 4) calmodulin light chains. (biologyonline.com)
  • May be a homodimer, which associates with multiple calmodulin or myosin light chains. (lu.se)
  • Brush border myosin I is a single-headed myosin found in the microvilli of vertebrate intestinal epithelial cells, linking the membrane to the microfilament core. (biologyonline.com)
  • Both young and old rats displayed an increase in developmental myosin heavy chain (MHCdev+) labeling in the exposed muscle, indicating muscle regeneration. (cdc.gov)
  • The MYO2 gene product is an unconventional myosin from yeast involved in polarized secretion. (biologyonline.com)
  • Structural analysis of myosin heavy chain kinase A from Dictyostelium. (wikipedia.org)
  • Leukemic B lymphocytes of a large group of unrelated chronic lymphocytic leukemia (CLL) patients express an unmutated heavy chain immunoglobulin variable (V) region encoded by IGHV1-69, IGHD3-16, and IGHJ3 with nearly identical heavy and light chain complementarity-determining region 3 sequences. (nih.gov)
  • However, to obtain complete recovery with a normal level of myosin heavy chain type IIB expression, more than 4 weeks of abstinence is necessary. (eurekamag.com)
  • Between species and tissue s there are considerable variations in the properties of Myosin II. (biologyonline.com)
  • Myosin II is the type of myosin found in muscle cells and is responsible for producing muscle contraction. (biologyonline.com)
  • Cardona A, Fernández J, Solana J, Romero R. An in situ hybridization protocol for planarian embryos: monitoring myosin heavy chain gene expression. (stowers.org)
  • In cardiac and skeletal muscle cells, the β-myosin heavy chain forms part of a larger protein called type II myosin. (nih.gov)
  • 1. Altered expression of skeletal muscle myosin isoforms in cancer cachexia. (nih.gov)
  • 9. Microgravity-induced transformations of myosin isoforms and contractile properties of skeletal muscle. (nih.gov)
  • Studies have shown that older individuals have reduced expression of mitochondrial respiratory chain complexes and reduced aerobic respiration in skeletal muscle 3,4 . (researchsquare.com)
  • A number of conventional and unconventional myosins. (embl.de)
  • 2. The roles of myosin ATPase activity and myosin light chain relative content in the slowing of type IIB fibers with hindlimb unweighting in rats. (nih.gov)
  • The heavy chains possess actin-binding and ATPase activity. (bvsalud.org)
  • The MYH7 gene provides instructions for making a protein known as the beta (β)-myosin heavy chain. (nih.gov)
  • Each type II myosin protein consists of two heavy chains (produced from the MYH7 gene) and two pairs of regulatory light chains (produced from several other genes). (nih.gov)
  • Most MYH7 gene mutations that cause familial hypertrophic cardiomyopathy change single protein building blocks (amino acids) in the β-myosin heavy chain protein. (nih.gov)
  • Changes in the MYH7 gene probably disrupt the normal function of type II myosin in muscle cells. (nih.gov)
  • 8. Effects of thyroid hormone receptor gene disruption on myosin isoform expression in mouse skeletal muscles. (nih.gov)
  • The MYO5A gene is one of three myosin V heavy-chain genes, belonging to the myosin gene superfamily. (nih.gov)
  • We have used these cells as transformation recipients for an altered myosin heavy chain gene that encodes a protein bearing a carboxy-terminal 34-kD truncation. (rupress.org)
  • Sarcomeres are composed of thick filaments made up of type II myosin and thin filaments made up of actin. (nih.gov)
  • Some of these mutations change single amino acids, while others delete a single amino acid from the heavy chain. (nih.gov)
  • The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. (bvsalud.org)
  • 11. Myosin heavy chain is not selectively decreased in murine cancer cachexia. (nih.gov)
  • A 2.5-A resolution structure of calcium-free calmodulin (CaM) bound to the first two IQ motifs of the murine myosin V heavy chain reveals an unusual CaM conformation. (rcsb.org)
  • The binding of the myosin head to the actin filaments, together with the concomitant hydrolysis of ATP for energy, results in the contraction of the sarcomeres that in turn causes contraction of the entire muscle, resulting in movement (or the development of isometric tension that permits us to hold objects or resist being pulled). (medscape.com)
  • A subclass of myosins found generally associated with actin-rich membrane structures such as filopodia. (umassmed.edu)
  • A smooth-muscle myosin heavy-chain assay is performed in the first 24 hours. (medscape.com)
  • The smooth muscle myosin heavy-chain assay has greater sensitivity and specificity than transthoracic echocardiography (TTE), CT, and aortography, but it has less sensitivity and specificity than transesophageal echocardiography (TEE), MRI, and helical CT. (medscape.com)
  • It is unclear how these changes in the structure and function of myosin lead to progressive muscle weakness in people with Laing distal myopathy. (nih.gov)
  • Both young and old rats displayed an increase in developmental myosin heavy chain (MHCdev+) labeling in the exposed muscle, indicating muscle regeneration. (cdc.gov)
  • 3. Age effect on expression of myosin heavy and light chain isoforms in suspended rat soleus muscle. (nih.gov)
  • 5. Synergistic ablation does not affect atrophy or altered myosin heavy chain expression in the non-weight bearing soleus muscle. (nih.gov)
  • 6. [Expression of myosin heavy chain IIx mRNA as a molecular marker of disuse of soleus muscle in rats]. (nih.gov)
  • 7. Myosin heavy chain composition in normal and atrophic equine laryngeal muscle. (nih.gov)
  • 12. Hindlimb suspension induces the expression of multiple myosin heavy chain isoforms in single fibres of the rat soleus muscle. (nih.gov)
  • 15. UBR2 targets myosin heavy chain IIb and IIx for degradation: Molecular mechanism essential for cancer-induced muscle wasting. (nih.gov)
  • We investigated biceps femoris long head (BFlh) myosin heavy chain (MHC) composition from biopsy samples, and the association of hamstrings composition and hamstrings muscle volume (using MRI) with knee flexor maximal and explosive strength. (elsevierpure.com)
  • The sarcomeric interaction of α- myosin heavy chain (α-MHC) with Titin is vital for cardiac structure and contraction. (bvsalud.org)
  • Spatial and temporal control of nonmuscle myosin localization: identification of a domain that is necessary for myosin filament disassembly in vivo. (rupress.org)
  • Myosin Type I" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (umassmed.edu)
  • Unconventional myosin Myo1c promotes membrane fusion in a regulated exocytic pathway. (umassmed.edu)
  • Myosin-9 is implicated in diseases such as Macrothrombocytopenia with or without nephritis or sensorineural hearing loss, and autosomal dominant Deafness, 17. (receptor.ai)
  • Specifically, researchers suspect that mutations alter the structure of the tail region of the β-myosin heavy chain. (nih.gov)
  • The heavy chains each have two parts: a head region and a tail region. (nih.gov)
  • myosin heavy chain lactylation maintains sarcomeric structure and function and alleviates the development of heart failure. (bvsalud.org)
  • Most of the mutations result in changes in the tail region of the β-myosin heavy chain. (nih.gov)
  • Understanding the role of Myosin-9 could open doors to potential therapeutic strategies for these conditions. (receptor.ai)