|Medical Dictionary - Dictionary of Medicine and Human Biology|
A potent orally effective diuretic and antihypertensive agent related to chlorothiazide; can cause hypokalemia and hyperglycemia.
Rarely used term for an effusion of serous fluid into the gallbladder. [hydro- + G. chole, bile, + kystis, bladder]
hydrocholeresis (hi′dro-ko-ler-e′sis, -kol-er-)
Increased output of a watery bile of low specific gravity, viscosity, and solid content. [hydro- + G. chole, bile, + hairesis, a taking]
Pertaining to hydrocholeresis.
A potent analgesic derivative of codeine used as an antitussive and analgesic. Often used combined with aspirin or acetaminophen. SYN: dihydrocodeinone.
A gelatinous colloid in unstable equilibrium with its contained water, useful in dentistry for impressions because of its dimensional stability under controlled conditions. irreversible h. a h. whose physical state is changed by an irreversible chemical reaction when water is added to a powder and an insoluble substance is formed. reversible h. a h. composed of a base substance whose physical state may be changed from a solid or semisolid to a liquid by the application of heat and then changed to that of an elastic gel by cooling.
hydrocolpocele, hydrocolpos (hi-dro-kol′po-sel, -kol′pos)
Accumulation of mucus or other nonsanguineous fluid in the vagina. [hydro- + G. kolpos, bosom (vagina)]
hydrocortamate hydrochloride (hi-dro-kor′ta-mat)
An ester-salt of hydrocortisone, used topically in the treatment of acute and chronic dermatoses.
A reduction product (at C-11) of cortisone; a steroid hormone secreted by the adrenal cortex (the active hormone secreted in the greatest quantity by the adrenals) and the most potent of the naturally occurring glucocorticoids in humans; an antiinflammatory agent. SYN: cortisol. h. acetate an ester of h. with similar actions and uses as h.. SYN: cortisol acetate. h. cyclopentylpropionate an ester of h.. h. cypionate the cyclopentanepropionic ester of cortisone, for oral administration. h. hydrogen succinate a form of h. administered intravenously. h. sodium phosphate an anti-inflammatory agent for intravenous or intramuscular administration. h. sodium succinate a very soluble ester salt of h. (cortisol), used parenterally in the management of emergencies resulting from acute adrenal insufficiency.
An alkaloidal principle derived from cotarnine; it is the basic hydrolytic product of narcotine; also obtained from the mother liquors of thebaine.
hydrocyanic acid (hi′dro-si-an′ik)
HCN;a colorless, very toxic liquid, with the odor of bitter almonds, present in bitter almonds (amygdalin), the stones of peaches, plums and other fruits, and laurel leaves; inhalation of 300 p.p.m. causes death. SYN: hydrogen cyanide, prussic acid.
Poisoning with hydrocyanic acid.
A cyst with clear, watery contents. [hydro- + G. kystis, bladder]
1. An eruption of deeply seated vesicles, due to retention of fluid in the sweat follicles. 2. SYN: hidrocystoma. [hydro- + G. kystis, bladder, + -oma, tumor]
Water thirst, a characteristic of animals that ordinarily drink water. [hydro- + G. dipsa, thirst]
Periodic episodes of uncontrollable thirst, occasionally found in epileptic patients. [hydro- + G. dipsa, thirst, + mania, frenzy]
Diuresis effected by water.
The branch of physics concerned with the flow of liquids. [hydro- + G. dynamis, force]
hydrofluoric acid (hi-dro-flor′ik)
A solution of hydrogen fluoride gas in water; a poisonous, caustic, foaming liquid that is used to clean metals and can etch glass; extremely irritating to skin and lungs.
A colloid in which the particles are in the external or dispersion phase and water in the internal or dispersed phase. Cf.:hydrosol.
hydrogen (H) (hi′dro-jen)
1. A gaseous element, atomic no. 1, atomic wt. 1.00794. 2. The molecular form (H2) of the element. SYN: dihydrogen. [hydro- + G. -gen, producing] activated h. h. removed by a dehydrogenase, e.g., via a flavoprotein, from a metabolite for transference to another substance with which it combines. arseniureted h. SYN: arsine. h. bromide HBr;a colorless gas that has a very irritating odor and fumes in moist air; in aqueous solution, it is hydrobromic acid. h. chloride HCl;a very soluble gas which, in solution, forms hydrochloric acid. h. cyanide SYN: hydrocyanic acid. h. dehydrogenase a flavoprotein catalyzing the conversion of NAD+ to NADH by molecular h. (H2); i.e., H2 + NAD+ → H+ + NADH. h. dioxide SYN: h. peroxide. heavy h. SYN: h.-2. h. peroxide an unstable compound readily broken down to water and oxygen, a reaction catalyzed by various powdered metals and by the enzyme, catalase; a 3% solution is used as a mild antiseptic for skin and mucous membranes. SYN: h. dioxide, hydroperoxide. h. phosphide SYN: phosphine. phosphureted h. SYN: phosphine. h. sulfide H2S;a colorless, flammable, toxic gas with a familiar “rotten egg” odor, formed in the decomposition of organic matter containing sulfur; used as a reagent, and in the manufacture of chemicals. SYN: sulfureted h.. sulfureted h. SYN: h. sulfide.
The common h. isotope, making up 99.985% of the h. atoms occurring in nature. SYN: protium.
The isotope of h. of atomic wt. 2; the less common stable isotope of h., making up 0.015% of the h. atoms occurring in nature; the nucleus consists of a proton and a neutron. SYN: deuterium, heavy hydrogen.
A hydrogen isotope of atomic wt. 3; weakly radioactive, emitting beta particles to become the stable helium-3; half-life, 12.32 years. SYN: tritium.
hydrogenase (hi′dro-je-nas, hi-droj′e-nas)
1. Any enzyme that removes a hydride ion (or H:−) from NADH (or NADPH). SYN: hydrogenlyase. 2. The enzyme that catalyzes the reaction of 2H+ with ferricytochrome or ferredoxin to generate H2.
hydrogenation (hi′dro-je-na′shun, hi-droj′e-na-shun)
Addition of hydrogen to a compound, especially to an unsaturated fat or fatty acid; thus, soft fats or oils are solidified or “hardened.”
The decadic logarithm of the hydrogen ion concentration in blood or other fluid; its negative is the pH of that fluid.
SYN: hydrogenase (1) .
Pertaining to the motion of fluids and the forces giving rise to such motion.
That branch of kinetics concerned with fluids in motion.
Unstable in the presence of water.
A state in which the fluid in the tissues readily changes in amount.
Enzymes (EC class 3) cleaving substrates with addition of H2O at the point of cleavage; e.g., esterases, phosphatases, nucleases, peptidases. SYN: hydrolyzing enzymes. cysteine h. h. that utilize an active site cysteinyl residue for the catalytic event. serine h. h. that utilize an active site seryl residue for the catalytic event.
A class of lyases (EC 4.2.1.x) comprising enzymes removing H and OH as water, leading to formation of new double bonds within the affected molecule; the trivial names usually contain dehydratase or hydratase.
The circulating fluid in many of the invertebrates.
A solution containing the products of hydrolysis.
A chemical process whereby a compound is cleaved into two or more simpler compounds with the uptake of the H and OH parts of a water molecule on either side of the chemical bond cleaved; h. is effected by the action of acids, alkalies, or enzymes. Cf.:hydration. SYN: hydrolytic cleavage. [hydro- + G. lysis, dissolution]
Referring to or causing hydrolysis.
To subject to hydrolysis.
Massage produced by streams of water.
Protrusion of the meninges of brain or spinal cord through a defect in the bony wall, the sac so formed containing cerebrospinal fluid. [hydro- + G. meninx, membrane, + kele, hernia]
An instrument for determining the specific gravity or density of a liquid. SYN: areometer, gravimeter. [hydro- + G. meron, measure]
Accumulation of thin mucus or other watery fluid in the cavity of the uterus. [hydro- + G. metra, uterus]
Relating to hydrometry or the hydrometer.
Distention of uterus and vagina by fluid other than blood or pus. [hydro- + G. metra, uterus, + kolpos, bosom (vagina)]
Determination of the specific gravity of a fluid by means of a hydrometer.
Microcephaly associated with an increased amount of cerebrospinal fluid.
hydromorphone hydrochloride (hi-dro-mor′fon)
A synthetic derivative of morphine, with analgesic potency about 10 times that of morphine. SYN: dihydromorphinone hydrochloride.
A cystic tumor at the umbilicus, most commonly a vitellointestinal cyst. [hydro- + G. omphalos, umbilicus]
An increase of fluid in the dilated central canal of the spinal cord, or in congenital cavities elsewhere in the cord substance. [hydro- + G. myelos, marrow]
Protrusion of a portion of cord, thinned out into a sac distended with cerebrospinal fluid, through a spina bifida. [hydro- + G. myelos, marrow, + kele, tumor, hernia]
Dilation of the pelvis and calices of one or both kidneys. This may result from obstruction to the flow of urine, vesicoureteral reflux, or it may be a primary congenital deformity without an apparent cause. SYN: pelvocaliectasis, pyeloureterectasis. [hydro- + G. nephros, kidney, + -osis, condition]
Relating to hydronephrosis.
See h. ion.
Accumulation of serous fluid in the accessory tubes of the oviduct. [hydro- + G. para, beside, + salpinx, trumpet]
Relating to hydropathy.
The obsolete use of water to treat and cure disease.
Reduction or deprivation of water. [hydro- + G. penia, poverty]
Pertaining to or characterized by hydropenia.
A noninflammatory accumulation of fluid in the pericardial sac.
hydroperitoneum, hydroperitonia (hi′dro-par-i-to-ne′um, -to′ne-a)
SYN: ascites. [hydro- + peritoneum]
Those oxidoreductases that require H2O2 as hydrogen acceptors; e.g., peroxidases, catalase.
SYN: hydrogen peroxide.
hydrophil, hydrophile (hi′dro-fil, -fil)
A substance that is hydrophilic.
A tendency of the blood and tissues to absorb fluid. [hydro- + G. philos, fond]
1. Denoting the property of attracting or associating with water molecules, possessed by polar radicals or ions, as opposed to hydrophobic (2). 2. Tending to dissolve in water. 3. Polar. SYN: hydrophilous.
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