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hexamethonium compounds
Compounds containing the hexamethylenebis(trimethylammonium) cation. Members of this group frequently act as antihypertensive agents and selective ganglionic blocking agents.
hexanes
Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.
hexanols
Isomeric forms and derivatives of hexanol (C6H11OH).
hexanones
6-carbon straight-chain or branched ketones.
hexestrol
A synthetic estrogen that has been used as a hormonal antineoplastic agent.
hexetidine
A bactericidal and fungicidal antiseptic. It is used as a 0.1% mouthwash for local infections and oral hygiene. (From Martindale, The Extra Pharmacopoeia, 30th ed, p797)
hexobarbital
A barbiturate that is effective as a hypnotic and sedative.
hexobendine
A potent vasoactive agent that dilates cerebral and coronary arteries, but slightly constricts femoral arteries, without any effects on heart rate, blood pressure or cardiac output.
hexoprenaline
Stimulant of adrenergic beta 2 receptors. It is used as a bronchodilator, antiasthmatic agent, and tocolytic agent.
hexosamines
AMINO SUGARS created by adding an amine group to a hexose sugar.
hexoses
MONOSACCHARIDES whose molecules contain six carbon atoms, such as GLUCOSE and FRUCTOSE. They generally have the chemical formula C6H12O6.
hexuronic acids
Term used to designate tetrahydroxy aldehydic acids obtained by oxidation of hexose sugars, i.e. glucuronic acid, galacturonic acid, etc. Historically, the name hexuronic acid was originally given to ascorbic acid.
hexylresorcinol
A substituted dihydroxybenzene used topically as an antiseptic for the treatment of minor skin infections.
heymann nephritis antigenic complex
A complex of antigenic proteins obtained from the brush border of kidney tubules. It contains two principal components LOW DENSITY LIPOPROTEIN RECEPTOR-RELATED PROTEIN-2 and LDL-RECEPTOR RELATED PROTEIN-ASSOCIATED PROTEIN. The name of this complex is derived from researcher, Dr. Walter Heymann, who developed an experim...
high fructose corn syrup
Syrup made from corn used widely in foods and beverages as a cheaper alternative sweetener to SUCROSE (common table sugar). It is generated by enzymatic processing of natural corn syrup to produce a liquid most widely composed of 42 or 55% FRUCTOSE, GLUCOSE, and various POLYSACCHARIDES.
hippurates
Salts and esters of hippuric acid.
hirudins
Single-chain polypeptides of about 65 amino acids (7 kDa) from LEECHES that have a neutral hydrophobic N terminus, an acidic hydrophilic C terminus, and a compact, hydrophobic core region. Recombinant hirudins lack tyr-63 sulfation and are referred to as 'desulfato-hirudins'. They form a stable non-covalent complex wit...
histamine
An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
histamine agents
Drugs used for their actions on histaminergic systems. Included are drugs that act at histamine receptors, affect the life cycle of histamine, or affect the state of histaminergic cells.
histamine agonists
Drugs that bind to and activate histamine receptors. Although they have been suggested for a variety of clinical applications histamine agonists have so far been more widely used in research than therapeutically.
histamine antagonists
Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.
histamine h1 antagonists
Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other s...
histamine h1 antagonists, non-sedating
A class of non-sedating drugs that bind to but do not activate histamine receptors (DRUG INVERSE AGONISM), thereby blocking the actions of histamine or histamine agonists. These antihistamines represent a heterogenous group of compounds with differing chemical structures, adverse effects, distribution, and metabolism. ...
histamine h2 antagonists
Drugs that selectively bind to but do not activate histamine H2 receptors, thereby blocking the actions of histamine. Their clinically most important action is the inhibition of acid secretion in the treatment of gastrointestinal ulcers. Smooth muscle may also be affected. Some drugs in this class have strong effects i...
histamine h3 antagonists
Drugs that selectively bind to but do not activate HISTAMINE H3 RECEPTORS. They have been used to correct SLEEP WAKE DISORDERS and MEMORY DISORDERS.
histatins
A group of small, histidine-rich, cationic peptides in human SALIVA which are antibacterial and antifungal.
histidine
An essential amino acid that is required for the production of HISTAMINE.
histidinol
The penultimate step in the pathway of histidine biosynthesis. Oxidation of the alcohol group on the side chain gives the acid group forming histidine. Histidinol has also been used as an inhibitor of protein synthesis.
histocompatibility antigen h-2d
A component of the murine major histocompatibility complex class I family. It contains one Ig-like C1-type domain and functions in processing and presentation of exogenous peptide antigens to the immune system.
histocompatibility antigens
A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transpl...
histocompatibility antigens class i
Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on mos...
histocompatibility antigens class ii
Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 1...
histone deacetylase inhibitors
Compounds that inhibit HISTONE DEACETYLASES. This class of drugs may influence gene expression by increasing the level of acetylated HISTONES in specific CHROMATIN domains.
hiv antigens
Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (LAV) antigens.
hiv core protein p24
A major core protein of the human immunodeficiency virus encoded by the HIV gag gene. HIV-seropositive individuals mount a significant immune response to p24 and thus detection of antibodies to p24 is one basis for determining HIV infection by ELISA and Western blot assays. The protein is also being investigated as a p...
hiv envelope protein gp120
External envelope protein of the human immunodeficiency virus which is encoded by the HIV env gene. It has a molecular weight of 120 kDa and contains numerous glycosylation sites. Gp120 binds to cells expressing CD4 cell-surface antigens, most notably T4-lymphocytes and monocytes/macrophages. Gp120 has been shown to in...
hiv envelope protein gp41
Transmembrane envelope protein of the HUMAN IMMUNODEFICIENCY VIRUS which is encoded by the HIV env gene. It has a molecular weight of 41,000 and is glycosylated. The N-terminal part of gp41 is thought to be involved in CELL FUSION with the CD4 ANTIGENS of T4 LYMPHOCYTES, leading to syncytial formation. Gp41 is one of t...
hiv fusion inhibitors
Inhibitors of the fusion of HIV to host cells, preventing viral entry. This includes compounds that block attachment of HIV ENVELOPE PROTEIN GP120 to CD4 RECEPTORS.
hiv integrase inhibitors
Inhibitors of HIV INTEGRASE, an enzyme required for integration of viral DNA into cellular DNA.
hiv protease inhibitors
Inhibitors of HIV PROTEASE, an enzyme required for production of proteins needed for viral assembly.
hla-a11 antigen
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*11 allele family.
hla-a1 antigen
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*01 allele family.
hla-a24 antigen
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*24 allele family.
hla-a2 antigen
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.
hla-a3 antigen
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*03 allele family.
hla-a antigens
Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of...
hla antigens
Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.
hla-b13 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*13 allele family.
hla-b14 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*14 allele family.
hla-b15 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*15 allele family.
hla-b18 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*18 allele family.
hla-b27 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*27 allele family.
hla-b35 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*35 allele family.
hla-b37 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*37 allele family.
hla-b38 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*38 allele family.
hla-b39 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*39 allele family.
hla-b40 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*40 allele family.
hla-b44 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*44 allele family.
hla-b51 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*51 allele family.
hla-b52 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*52 allele family.
hla-b7 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*07 allele family.
hla-b8 antigen
A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*08 allele family.
hla-b antigens
Class I human histocompatibility (HLA) surface antigens encoded by more than 30 detectable alleles on locus B of the HLA complex, the most polymorphic of all the HLA specificities. Several of these antigens (e.g., HLA-B27, -B7, -B8) are strongly associated with predisposition to rheumatoid and other autoimmune disorder...
hla-c antigens
Class I human histocompatibility (HLA) antigens encoded by a small cluster of structural genes at the C locus on chromosome 6. They have significantly lower immunogenicity than the HLA-A and -B determinants and are therefore of minor importance in donor/recipient crossmatching. Their primary role is their high-risk ass...
hla-d antigens
Human immune-response or Class II antigens found mainly, but not exclusively, on B-lymphocytes and produced from genes of the HLA-D locus. They are extremely polymorphic families of glycopeptides, each consisting of two chains, alpha and beta. This group of antigens includes the -DR, -DQ and -DP designations, of which ...
hla-dp alpha-chains
Transmembrane proteins that form the alpha subunits of the HLA-DP antigens.
hla-dp antigens
A group of the D-related HLA antigens (human) found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.
hla-dp beta-chains
Transmembrane proteins that form the beta subunits of the HLA-DP antigens.
hla-dq alpha-chains
Transmembrane proteins that form the alpha subunits of the HLA-DQ antigens.
hla-dq antigens
A group of the D-related HLA antigens found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.
hla-dq beta-chains
Transmembrane proteins that form the beta subunits of the HLA-DQ antigens.
hla-dr1 antigen
An HLA-DR antigen associated with HLA-DRB1 CHAINS that are encoded by DRB1*01 alleles.
hla-dr2 antigen
A broad specificity HLA-DR antigen that is associated with HLA-DRB1 CHAINS encoded by DRB1*01:15 and DRB1*01:16 alleles.
hla-dr3 antigen
An HLA-DR antigen which is associated with HLA-DRB1 CHAINS encoded by DRB1*03 alleles.
hla-dr4 antigen
An HLA-DR antigen which is associated with HLA-DRB1 CHAINS encoded by DRB1*04 alleles.
hla-dr5 antigen
A broad-specificity HLA-DR antigen that is associated with HLA-DRB1 CHAINS encoded by DRB1*11 and DRB1*12 alleles.
hla-dr6 antigen
A broad-specificity HLA-DR antigen that is associated with HLA-DRB1 CHAINS encoded by DRB1*13 and DRB1*14 alleles.
hla-dr7 antigen
A HLA-DR antigen that is associated with HLA-DRB1 CHAINS encoded by DRB1*07 alleles.
hla-dr alpha-chains
Transmembrane proteins that form the alpha subunits of the HLA-DR antigens. They are also referred to as the HLA-DR heavy chains.
hla-dr antigens
A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.
hla-drb1 chains
A subtype of HLA-DRB beta chains that includes over one hundred allele variants. The HLA-DRB1 subtype is associated with several of the HLA-DR SEROLOGICAL SUBTYPES.
hla-drb3 chains
A subtype of HLA-DRB beta chains that includes over 50 allelic variants. The HLA-DRB3 beta-chain subtype is associated with HLA-DR52 serological subtype.
hla-drb4 chains
A subtype of HLA-DRB beta chains that is associated with the HLA-DR53 serological subtype.
hla-drb5 chains
A subtype of HLA-DRB beta chains that is associated with the HLA-DR51 serological subtype.
hla-dr beta-chains
Transmembrane proteins that form the beta subunits of the HLA-DR antigens. They are also referred to as the HLA-DR light chains.
hla-dr serological subtypes
HLA-DR antigen subtypes that have been classified according to their affinity to specific ANTIBODIES. The DNA sequence analyses of HLA-DR ALPHA-CHAINS and HLA-DR BETA-CHAINS has for the most part revealed the specific alleles that are responsible for each serological subtype.
hla-e antigens
Class I human histocompatibility (HLA) antigens encoded by genes at the E locus on chromosome 6. They bind a restricted subset of peptides derived from the leader peptides of other class I molecules. They primarily are involved with down-regulating cytolytic activity of NK CELLS and restricting non-canonical CD8-POSITI...
hla-g antigens
Class I human histocompatibility (HLA) surface antigens encoded by alleles on locus B of the HLA complex. The HLA-G antigens are considered non-classical class I antigens due to their distinct tissue distribution which differs from HLA-A; HLA-B; and HLA-C antigens. Note that several isoforms of HLA-G antigens result fr...
hn protein
Glycoprotein from Sendai, para-influenza, Newcastle Disease, and other viruses that participates in binding the virus to cell-surface receptors. The HN protein possesses both hemagglutinin and neuraminidase activity.
holmium
An element of the rare earth family of metals. It has the atomic symbol Ho, atomic number 67, and atomic weight 164.93.
holothurin
A highly toxic saponin occurring in HOLOTHUROIDEA. This marine toxin is an anionic surfactant, hemolyzing ERYTHROCYTES.
homocysteine
A thiol-containing amino acid formed by a demethylation of METHIONINE.
homogentisic acid
Dihydroxyphenylacetic acid with hydroxyls at the 2 and 5 positions of the phenyl ring.
homoharringtonine
Semisynthetic derivative of harringtonine that acts as a protein synthesis inhibitor and induces APOPTOSIS in tumor cells. It is used in the treatment of MYELOID LEUKEMIA, CHRONIC.
homosteroids
Steroids whose structure has been expanded by the addition of one or more carbon atoms to the ring skeleton in any of the four rings.
homovanillic acid
A 3-O-methyl ETHER of (3,4-dihydroxyphenyl)acetic acid.
hormone antagonists
Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.
hormones
Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by ...
hormones, ectopic
Hormones released from neoplasms or from other cells that are not the usual sources of hormones.
hormones, hormone substitutes, and hormone antagonists
A collective grouping for both naturally occurring and synthetic hormones, substitutes, and antagonists.