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|Medical Dictionary - Dictionary of Medicine and Human Biology|
agamogenesis (ag′a-mo-jen′e-sis, a-gam-o-)
SYN: asexual reproduction. [G. agamos, unmarried, + genesis, production]
agamogenetic (ag′a-mo-je-net′ik, -a-gam-o-)
Indicating asexual reproduction.
SYN: asexual reproduction. [G. agamos, unmarried, + gonos, offspring]
Agamomermis culicis (ag-a-mo-mer′mis ku′li-kis)
A species of nematode parasitic in the mosquito; a few cases have been recorded in humans, usually larval worms found emerging from body openings, presumably after ingestion of infected insects or application of moist earth bearing free-living larval stages. [G. agamos, unmarried, + Mod. L., fr. G. mermis, cord; L. culex, gnat]
SYN: schizont. [G. agamos, unmarried, + on (ont-), being]
SYN: agamic. [G. agamos, unmarried]
The state of being without ganglia; e.g., absence of ganglion cells from the myenteric plexus as a characteristic of congenital megacolon. [G. a- priv. + ganglion + -osis, condition]
The doctrine that exalts nonsexual (brotherly) love. [G. agape, brotherly love]
agar (ah′gar, a′gar)
A complex polysaccharide (a sulfated galactan) derived from seaweed (various red algae); used as a solidifying agent in culture media; it has the valuable property of melting at 100°C, but not solidifying until 49°C. [Bengalese] bile salt a. an a. medium containing lactose, peptone, sodium taurocholate, and neutral red, for the growth and isolation of Gram-negative rods. birdseed a. media prepared from Guizottia abyssinica seeds used in culturing and in the presumptive diagnosis of Cryptococcus neoformans. blood a. a mixture of blood, usually sheep or horse, and an a.-based medium used for the cultivation of many medically important microorganisms. Bordet-Gengou potato blood a. glycerine-potato a. with 25% of blood, used for the isolation of Bordetella pertussis. brain-heart infusion a. a medium used for the isolation of fastidious microorganisms, especially fungi. chocolate a. blood a. heated until the blood becomes brown or chocolate in color, used especially to isolate Haemophilus or Neisseria and other species for which unheated blood is inhibitory. cholera a. an alkaline a. medium for cultivating Vibrio cholerae. cornmeal a. a culture medium that is low in nutrients, used extensively in the study of yeastlike and filamentous fungi; it suppresses vegetative growth while stimulating sporulation of many species, and is widely used for producing the distinctive chlamydospores of Candida albicans. Czapek solution a. a culture medium used for the cultivation of fungus species and for identification of Aspergillus and Penicillium species. SYN: Czapek-Dox medium. EMB a. SYN: eosin-methylene blue a.. Endo a. a medium containing peptone, lactose, dipotassium phosphate, a., sodium sulfite, basic fuchsin, and distilled water; originally developed for the isolation of Salmonella typhi, this medium is now most useful in the bacteriological examination of water; coliform organisms ferment the lactose, and their colonies become red and color the surrounding medium; non-lactose-fermenting organisms produce clear, colorless colonies against the faint pink background of the medium. SYN: Endo medium. eosin-methylene blue a. a. composed of peptone, lactose, and sucrose and containing eosin and methylene blue, used to distinguish between lactose-fermenting and non–lactose-fermenting Gram-negative bacteria. Echerichia sp. show a characteristic sheen. SYN: EMB a.. MacConkey a. medium containing peptone, lactose, bile salts, neutral red, and crystal violet, used to identify Gram-negative bacilli and characterize them according to their status as lactose fermenters. Fermenters appear as pink colonies while nonfermenters are colorless. Mueller-Hinton a. medium containing beef infusion, peptone, and starch used primarily for the disk-a. diffusion method for antimicrobial susceptibility testing. Novy and MacNeal blood a. a nutrient a. containing two volumes of defibrinated rabbit's blood; suitable for the cultivation of a number of trypanosomes. nutrient a. a simple solid medium containing beef extract, peptone, a., and water; used for growing many common heterotrophic bacteria. oatmeal-tomato paste a. a special culture medium for the production of ascospore formation in the dermatophytes. potato dextrose a. a culture medium used extensively for the cultivation of fungi; especially good for development of conidia and other sporulating forms by which an organism is identified microscopically. rice-Tween a. a useful medium for the development of the chlamydospores in Candida albicans and for preparation of slide cultures for other forms of sporulation in other fungal species. Sabouraud a. a culture medium for fungi containing neopeptone or polypeptone a. and glucose, with final pH 5.6; it is the standard, most universally used medium in mycology and is the international reference. Modified Sabouraud a. (Emmons modification) with neutral pH and less glucose is better for pigment development in the colonies. Sabouraud dextrose a. a dextrose peptone medium that supports the growth of most pathogenic fungi. serum a. an enriched medium for cultivation of fastidious organisms; prepared by adding sterile serum to melted a.. Thayer-Martin a. a Mueller-Hinton a. with 5% heat-hemolyzed sheep blood and antibiotics, used for transport and primary isolation of Neisseria gonorrhoeae and Neisseria meningitidis. SYN: Thayer-Martin medium. yeast extract a. a medium used to induce sporulation and reduce vegetative growth in the cultivation of fungi.
The dried fruit body of Polyporus officinalis (family Polyporaceae), occurring in the form of brownish or whitish light masses, which contains a. acid. SYN: amadou. [G. agarikon, a kind of fungus] deadly a. SYN: Amanita phalloides. fly a. SYN: Amanita muscaria.
agaric acid (a-gar′ik)
Obtained from agaric and responsible for the anhidrotic action of the mushroom; used as an anhidrotic agent.
A large genus of mushrooms of which many are edible and others poisonous. [L. agaricum, fr. G. agarikon, a tree fungus]
A polysaccharide found in agar preparations consisting of d-galactose linked β1,3 glycosidically. Some of the galactosyl units are sulfated.
The neutral linear polysaccharide fraction found in agar preparations, generally composed of d-galactose and altered 3,6-anhydrogalactose residues; used in chromatography and electrophoresis.
Without stomach or digestive tract. [G. a- priv. + gaster, belly]
Lessened nervous control of the stomach. [G. a- priv. + gaster, belly, + neuron, nerve]
Abbreviation for automatic gain control.
1. The period that has elapsed since birth. 2. One of the periods into which human life is divided, distinguished by physical evolution, equilibrium, and involution; e.g., the seven ages of mankind are: infancy, childhood, adolescence, maturity, middle life, senescence, and senility. 3. To grow old; to gradually develop changes in structure that are not due to preventable disease or trauma and that are associated with decreased functional capacity and an increased probability of death. 4. To cause artificially the appearance characteristic of one who has lived long or of a thing that has existed for a long time. 5. In dentistry, to heat an alloy for amalgam so as to make it set more slowly, increase strength, reduce flow, and have a stable shelf life; aging occurs by relieving internal strains. [F. âge, L. aetas] achievement a. the relationship between the chronologic a. and the a. of achievement, as established by standard achievement tests. anatomical a. a. in terms of structure rather than of function or of passage of time. SYN: physical a.. basal a. highest mental a. level of the Stanford-Binet intelligence scale at which all items are passed. Binet a. the a. of the normal child with whose intelligence (as measured by the Stanford-Binet scale) the intelligence of the abnormal child corresponds (the profoundly retarded individual functions like a child of 1–2 years; the moderately to severely retarded, 3–7 years; the borderline to mildly retarded, 8–12 years). bone a. stage of development of bone (in years) as adjudged by radiography, in contrast to chronologic a.. childbearing a. the period in a woman's life between puberty and menopause. chronologic a. (CA) a. expressed in years and months; used as a measurement against which to evaluate a child's mental a. in computing the Stanford-Binet intelligence quotient. developmental a. 1. a. estimated by anatomic development since fertilization; 2. (DA) a. of an individual estimated from the degree of anatomic, physiologic, mental, and emotional maturation. emotional a. a measure of emotional maturity by comparison with average emotional development. gestational a. 1. in embryology, the a. of a conceptus expressed in elapsed time since conception; 2. in obstetrics, the developmental a. of a fetus, usually based on the presumed first day of the last normal menstrual period. menstrual a. a. of the conceptus computed from the start of the mother's last menstrual period. mental a. (MA) a measure, expressed in years and months, of a child's intelligence relative to a. norms as determined by testing with the Stanford-Binet intelligence scale. physical a. SYN: anatomical a.. physiologic a. a. estimated in terms of function.
Absence or failure of formation of any part. [G. a- priv. + genesis, production] gonadal a. absence of one or both gonads. müllerian a. SYN: Mayer-Rokitansky-Küster-Hauser syndrome. renal a. absence of one or both kidneys, most commonly unilateral with absence of the ipsilateral paramesonephric duct and its derivatives; renal function is normal as long as the remaining kidney is intact; bilateral or complete renal a. is associated with Potter facies and neonatal death. thymic a. absence of the thymus, which may be associated with parathyroid a. in DiGeorge syndrome.
Congenital absence of genitalia.
Markedly defective formation or absence of the genitalia; usually accompanied by protrusion of the abdominal viscera through an incomplete abdominal wall. [G. a- priv. + genos, sex, + soma, body]
1. An active force or substance capable of producing an effect. For agents not listed here, see the specific name. 2. A disease, a factor such as a microorganism, chemical substance, or a form of radiation the presence or absence of which (as in deficiency diseases) results in disease or more advanced disease. [L. ago, pres. p. agens (a.-), to perform] adrenergic blocking a. a compound that selectively blocks or inhibits responses to sympathetic adrenergic nerve activity (sympatholytic a.) and to epinephrine, norepinephrine, and other adrenergic amines (adrenolytic a.); two distinct classes exist, alpha- and beta-adrenergic receptor blocking agents. α-adrenergic blocking a. a class of drugs that compete with α-adrenergic agonists for available receptor sites: some compete for both α1 and α2 receptors ( e.g., phentolamine, dibenzyline) while others are primarily either α1 ( e.g., prazosin, terazosin) or α2 receptor blocking agents ( e.g., yohimbine). SYN: α-adrenoceptor antagonist, alpha-blocker. β-adrenergic blocking a. a class of drugs that compete with β-adrenergic agonists for available receptor sites; some compete for both β1 and β2 receptors ( e.g., propranolol) while others are primarily either β1 ( e.g., metoprolol) or β2 blockers; used in the treatment of a variety of cardiovascular diseases where β-adrenergic blockade is desirable. SYN: β-adrenergic receptor blocking a., β-adrenoreceptor antagonist, beta-blocker. adrenergic neuronal blocking a. a drug that prevents the release of norepinephrine from sympathetic nerve terminals ( e.g., guanethidine); it does not inhibit the responses of the adrenergic receptors to circulating epinephrine, norepinephrine, and other adrenergic amines. β-adrenergic receptor blocking a. SYN: β-adrenergic blocking a.. alkylating a. a drug or chemical that, via the formation of covalent bonds, forms a derivatized tissue constituent permanently containing part of the drug or chemical compound; frequently carcinogenic and mutagenic, but often used in the chemotherapy of cancer ( e.g., nitrogen mustards and carmustine). antianxiety a. a functional category of drugs useful in the treatment of anxiety and able to reduce anxiety at doses that do not cause excessive sedation. The majority of commonly used drugs falling into this category are benzodiazepines, which act at the γ-aminobutyric acid (GABA) receptor sites. Historically, barbiturates were the main agents in this category; a newer category, which acts at serotonin (5-HT1A) receptor sites, is currently represented by buspirone. SYN: anxiolytic (1) , minor tranquilizer. antidyskinetic a. a functional category of drugs with anticholinergic action, used to treat Parkinson disease and some of the acute movement disorders that may be caused by antipsychotic agents. antifoaming agents chemicals that lower surface tension (hence production of foam), used in laboratory evaporations, and also administered with oxygen to relieve the respiratory obstruction aggravated by the foam of edema fluid in pulmonary edema (pulmonary surfactant). antipsychotic a. a functional category of neuroleptic drugs that are helpful in the treatment of psychosis and have a capacity to ameliorate thought disorders. SYN: antipsychotic (1) , major tranquilizer. atypical antipsychotic a. a functional category of newer antipsychotic drugs thought to exert their action predominantly via serotonergic blockade. bacteriostatic a. SYN: bacteriostat. Bittner a. SYN: mammary tumor virus of mice. blister a. blocking a. a class of drugs that inhibit (block) a biologic activity or process, such as axonal conduction or transmission, access to a receptor, or movement of ions across a cell membrane; frequently called “blockers.” calcium channel-blocking a. a class of drugs that have the ability to inhibit movement of calcium ions across the cell membrane; of particular value in the treatment of cardiovascular disorders because of pharmacologic effects such as depression of mechanical contraction of cardiac and smooth muscle and of both impulse formation and conduction velocity ( e.g., verapamil, nifedipine). SYN: calcium antagonist, slow channel-blocking a.. chimpanzee coryza a. (CCA) SYN: respiratory syncytial virus. cholinergic a. an a. that mimics the action of acetylcholine or of the parasympathetic nervous system ( e.g., methacholine). contrast a. SYN: contrast medium. cycle-specific a. an a. that has effect in only one part of the cell cycle (S phase) or only when the cell is in a specific part of the cell cycle. delta a. SYN: hepatitis D virus. Eaton a. SYN: Mycoplasma pneumoniae. embedding agents materials such as celloidin, paraffin, etc. in which specimens of tissue are set before being cut into sections for microscopic examination. enterokinetic a. an a. used to relieve intestinal atony. F a. obsolete term for F plasmid. fertility a. obsolete term for F plasmid. foamy agents SYN: foamy viruses, under virus. ganglionic blocking a. an a. that impairs the passage of impulses in autonomic ganglia ( e.g., tetraethylammonium, trimethaphan). high osmolar contrast a. ionic water-soluble iodinated contrast medium. SYN: high osmolar contrast medium. initiating a. initiation. inotropic agents drugs that increase the force of contraction of cardiac muscle; examples include digitalis glycosides, amrinone, and epinephrine. LDH a. SYN: lactate dehydrogenase virus. low osmolar contrast a. (LOCA) nonionic water-soluble radiographic contrast material. SYN: low osmolar contrast medium, nonionic contrast a.. luting a. a fastening material or cement; e.g., plaster or wax to hold casts to an articulator, or material to hold crowns to teeth. mood stabilizing a. a functional category of drugs used to normalize mood, particularly by dampening mood swings ( e.g., lithium and some anticonvulsants such as carbamazepine and valproic acid). neuroleptic a. SYN: neuroleptic. neuromuscular blocking agents a group of drugs that prevent motor nerve endings from exciting skeletal muscle. They act either by competing for the neurotransmitter, acetylcholine (like D-tubocurarine, mivacurium, and pancuronium), or by first stimulating the postjunctional muscle membrane and subsequently desensitizing the muscle endplates to the acetylcholine (like succinylcholine or decamethonium); used in surgery to produce paralysis and facilitate manipulation of muscles. non–cycle-specific a. a. that has effect regardless of where the cell is in its division cycle. nondepolarizing neuromuscular blocking a. a compound that paralyzes skeletal muscle primarily by inhibiting transmission of nerve impulses at the neuromuscular junction rather than by affecting the membrane potention of motor endplate or muscle fibers ( e.g., curare, gallamine, vecuronium). nonionic contrast a. SYN: low osmolar contrast a.. Norwalk a. a strain of epidemic gastroenteritis virus that belongs to the calciviruses. [Norwalk, Ohio, where first implicated in disease] Pittsburgh pneumonia a. SYN: Legionella micdadei. promoting a. promotion. psychotropic a. a chemical compound that influences the human psyche. reovirus-like a. SYN: rotavirus. sclerosing a. a compound that acts by irritation of the veinous intimal epithelium; used in the treatment of varicose veins. slow channel-blocking a. SYN: calcium channel-blocking a.. sympathetic a. sympathomimetic amine. transforming a. 1. SYN: mitogen. 2. virus that can transform cells. TRIC agents strains of Chlamydia trachomatis that cause trachoma and inclusion conjunctivitis agents See Chlamydia trachomatis. typical antipsychotic a. a functional category of older antipsychotic drugs thought to exert their action predominantly via dopaminergic blockade.
An herbicide and defoliant, consisting of (2,4,5-trichlorophenoxy)acetic acid, (2,4-dichlorophenoxy) acetic acid, and dioxin, that was widely used in the Vietnam War; it has been shown to possess residual post-exposure carcinogenic and teratogenic properties in humans.
An appearance of youth in old age. [G. a., eternal youth, fr. a- priv. + geras, old age]
Loss or absence of the sense of taste. It may be: 1) general to all tastants (total), partial to some tastants, or specific to one or more tastants; 2) due to transport disorders (in access to the interior of the taste bud) or sensorineural disorders (affecting the gustatory sensory cells or nerves or the central gustatory neural pathways); or 3) hereditary or acquired. SYN: ageustia, gustatory anesthesia. [G. a- priv. + geusis, taste]
agger, pl .aggeres (aj′er, -ez; ag′er) [TA]
An eminence, projection, or shallow ridge. [L. mound] a. nasi [TA] an elevation on the lateral wall of the nasal cavity lying between the atrium of the middle meatus and the olfactory sulcus; it is formed by the mucous membrane covering the base of the ethmoidal crest of the maxilla. SYN: nasal ridge. a. perpendicularis SYN: eminence of triangular fossa of auricle. a. valvae venae SYN: prominence of venous valvular sinus.
agglomerate, agglomerated (a-glom′er-at)
SYN: aggregated. [L. ag-glomero, to wind into a ball; from ad, to, + glomus, a ball]
A substance that holds parts together or causes agglutination. [L. ad, to + gluten, glue]
To accomplish, or be subjected to, agglutination.
1. The process by which suspended bacteria, cells, or other particles are caused to adhere and form into clumps; similar to precipitation, but the particles are larger and are in suspension rather than being in solution. For specific a. reactions in the various blood groups, see Blood Groups appendix. 2. Adhesion of the surfaces of a wound. 3. The process of adhering. [L. ad, to, + gluten, glue] acid a. the clumping together of certain microorganisms at high hydrogen ion concentration. bacteriogenic a. the clumping of cells as a result of effects of bacteria or their products. cold a. a. of red blood cells by their own serum (see autoagglutination), or by any other serum when the blood is cooled below body temperature, but most pronounced below 25°C; the phenomenon results from cold agglutinins; may be seen occasionally in the blood of apparently normal persons or as a pathologic finding in patients with primary atypical pneumonia, infectious mononucleosis, and other viral diseases, certain protozoan infections, or lymphoproliferative neoplasms. See autoagglutination. cross a. SYN: group a.. false a. SYN: pseudoagglutination (1) . group a. a. by antibodies specific for minor (group) antigens common to several microorganisms, each of which possesses its own major specific antigen. SYN: cross a.. immune a. a. caused by antibody (agglutinin) that is specific for the suspended microorganism, cell, or for an antigen that has been coated on a particle of suitable size. indirect a. SYN: passive a.. nonimmune a. 1. a. caused by a lectin having a degree of specificity for a particular sugar, the mechanism of which is not understood; 2. a. that results from nonspecific factors, as in the case of acid a. or spontaneous a.. passive a. a. of particles that have been coated with soluble antigen, by antiserum specific for the adsorbed antigen. SYN: indirect a.. spontaneous a. nonspecific clumping of organisms in saline related to lack of polar groups in electrolyte solution.
Causing, or able to cause, agglutination.
1. An antibody that causes clumping or agglutination of the bacteria or other cells that either stimulated the formation of the a., or contain immunologically similar, reactive antigen. SYN: agglutinating antibody, immune a.. 2. A substance, other than a specific agglutinating antibody, that causes organic particles to agglutinate, e.g., plant a.. blood group agglutinins see Blood Groups appendix. chief a. SYN: major a.. cold a. an antibody which reacts more efficiently at temperatures below 37°C. cross-reacting a. SYN: group a.. flagellar a. SYN: H a. (1) . group a. an immune a. specific for a “shared” or common antigen. SYN: cross-reacting a.. H a. 1. an a. that is formed as the result of stimulation by, and which reacts with, the thermolabile antigen(s) in the flagella of motile strains of microorganisms; SYN: flagellar a.. 2. see ABO blood group, Blood Groups appendix. immune a. SYN: a. (1) . incomplete a. (a-gloo′ti-nin) antibody that binds to antigen but does not induce agglutination. These antibodies are usually of the IgG class and are referred to as incomplete antibody. major a. immune a. present in greatest quantity in an antiserum and evoked by the most dominant of a mosaic of antigens. SYN: chief a.. minor a. immune a. present in an antiserum in lesser concentration than the major a.. SYN: partial a.. O a. 1. an a. that is formed as the result of stimulation by, and that reacts with, the relatively thermostable antigen(s) that are part of the cell wall of certain microorganisms; SYN: somatic a.. 2. see ABO blood group, Blood Groups appendix. partial a. SYN: minor a.. plant a. a lectin. saline a. an antibody that causes agglutination of erythrocytes when they are suspended either in saline or in a protein medium. SYN: complete antibody. somatic a. SYN: O a. (1) . warm agglutinins an a. that is more reactive at 37°C than at lower temperatures.
An antigenic substance that stimulates the formation of specific agglutinin, which can cause agglutination of cells that contain the antigen or particles coated with the antigen. SYN: agglutogen. [agglutinin + G. -gen, production] blood group agglutinogens see Blood Groups appendix. T a. obsolete term for an a. formed from a latent receptor on human red cells by the action of an enzyme in cultures of certain bacteria.
Capable of causing the production of an agglutinin. SYN: agglutogenic.
Readily undergoing pronounced agglutination. [agglutination + G. phileo, to love]
Candidate gene for otosclerosis located at 15q25 to q26.
1. To unite or come together in a mass or cluster. 2. The total of individual units making up a mass or cluster. [L. ag-grego, pp. -atus, to add to, fr. grex (greg-), a flock] proteoglycan a. a large aggregation of proteoglycans noncovalently bound to a long molecule of hyaluronic acid; involved in cross-linking the collagen fibrils of cartilage matrix.
Collected together, thereby forming a cluster, clump, or mass of individual units. SYN: agglomerate, agglomerated, agminate, agminated.
A crowded mass of independent but similar units; a cluster. SYN: agglomeration. familial a. occurrence of a trait in more members of a family than can be readily accounted for by chance; presumptive but not cogent evidence of the operation of genetic factors.
An instrument for measuring platelet aggregation by monitoring over time the changes in optic density of a platelet suspension treated with aggregating agents such as ADP, collagen, epinephrine, etc.
A substance of microbial origin postulated to inhibit the resistance mechanisms of the host. [L. agressor, an assailant, fr. ad-gredio, pp. -gressus, to attack]
A domineering, forceful, or assaultive verbal or physical action toward another person as the motor component of the affects of anger, hostility, or rage. [L. aggressio, fr. aggredior, to accost, attack]
1. Denoting aggression. 2. Denoting a competitive forcefulness or invasiveness, as of a behavioral pattern, a pathogenic organism, or a disease process.
1. The process of growing old, especially by failure of replacement of cells in sufficient number to maintain full functional capacity; particularly affects cells ( e.g., neurons) incapable of mitotic division. 2. The gradual deterioration of a mature organism resulting from time-dependent, irreversible changes in structure that are intrinsic to the particular species, and that eventually lead to decreased ability to cope with the stresses of the environment, thereby increasing the probability of death. 3. In the cardiovascular system, the progressive replacement of functional cell types by fibrous connective tissue. 4. A demographic term, meaning an increase over time in the proportion of older persons in the population. clonal a. the deterioration in successive generations of a clone; thus paramecia and other simple forms, if allowed to reproduce asexually for a number of generations, invariably undergo deterioration, the characters of each group of descendants progressively departing from those of the original sexually produced ancestor.
Abnormally rapid speech in which words are imperfectly spoken or dropped out of a sentence. SYN: agitolalia. [L. agito, to hurry, + G. phasis, speech]
Having no glomeruli; said especially of a kidney in which the glomeruli have been destroyed, or kidneys of certain fish, e.g., toad fish, that possess tubules but no glomeruli.
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