The clear periphery of a blood platelet. [hyalo- + G. meros, part]
An Old World genus (about 21 species) of large ixodid ticks with submarginal eyes, coalesced festoons, an ornate scutum, and a long rostrum. Adults parasitize all domestic ...
Morbid fear of glass objects. SYN: crystallophobia. [hyalo- + G. phobos, fear]
The protoplasmic fluid substance of a cell. [hyalo- + G. plasma, thing formed]
- nuclear h. SYN: karyolymph.
Inflammation of a serous membrane with a fibrinous exudate that eventually becomes hyalinized, resulting in a relatively thick, dense, opaque, glistening, white or gray-white ...
Degenerative changes in the vitreous body. [hyalo- + G. -osis, condition]
- asteroid h. numerous small spherical bodies (“snowball” opacities) in the corpus vitreum, ...
An oval or round structure within a cell nucleus that stains faintly but otherwise resembles a nucleolus. [hyalo- + G. soma, body]
A salt or ester of hyaluronic acid. SYN: hyalurate.
- h. lyase a lyase that catalyzes the cleavage of hyaluronic acid s, producing a number of ...
A mucopolysaccharide made up of alternating β1,4-linked residues of hyalobiuronic acid, forming a gelatinous material in the tissue spaces and acting as a lubricant and shock ...
1. Term used loosely for hyaluronate lyase, hyaluronoglucosaminidase, and hyaluronoglucuronidase, one or more of which are present in testis, sperm, other organs, bee and ...
An enzyme hydrolyzing β1,4 linkages in hyaluronates. SEE ALSO: hyaluronidase (1), hyaluronate lyase.
Oxygen therapy with pressures greater than 1 atmosphere or ambient oxygen pressure applied to the entire body in a chamber or room. [G. hyper, above, + baros, pressure, + oxys, ...
USAN-approved contraction for o-(4-hydroxybenzoyl)benzoate.
The word "hybrid" has a number of different biomedical meanings. In transmission genetics, a hybrid is the result of a cross between two genetically dissimilar parents. The ...
1. The process of breeding a hybrid. 2. Crossing over between related but nonallelic genes. 3. The specific reassociation of complementary strands of polynucleic acids; e.g., ...
Hybridization, fluorescent in situ
An important molecular cytogenetic method for identifying chromosomes and parts of chromosomes, deciphering chromosome rearrangements, and locating genes on chromosomes. " ...
Hybridization, in situ
The use of a DNA or RNA probe to detect the complementary sequence. In situ hybridization is like all nucleic acid hybridization in being a technique in which single-stranded ...
Hybridization, nucleic acid
A laboratory technique in which single-stranded nucleic acids (DNA or RNA) are allowed to interact so that complexes called hybrids are formed by molecules with similar, ...
A cell hybrid resulting from the fusion of a cancer cell and a normal lymphocyte (a type of white blood cell). The hybridoma is immortal in the laboratory and makes the same ...
USAN-approved contraction for monohydrochloride hemiethanolate hemihydrate, HCl 12C2H5OH 12H2O.
2,4-Imidazolidinedione; derived from urea or from allantoin; the NH–CH2–CO group is prototypical of α-amino acid s. H. derivatives are formed by the reaction of ...
1. SYN: h. cyst. 2. A vesicular structure resembling an Echinococcus cyst. [G. hydatis, a drop of water, a hyatid]
- Morgagni h. SYN: vesicular appendages of epoophoron, ...
Hydatid disease, alveolar (AHD)
A parasitic disease caused by the larval stage of a microscopic tapeworm Echinococcus multilocularis. AHD is found worldwide, mostly in northern latitudes. in central Europe, ...
A tumor that forms in the uterus as a mass of cysts resembling a bunch of grapes. Moles occur during the childbearing years. They do not spread outside of the uterus. However, a ...
A cystic mass composed of one or more hydatids formed in the scrotum. [ hydatid + G. kele, tumor]
The morbid state caused by the presence of hydatid cysts.
Surgical evacuation of a hydatid cyst. [ hydatid + G. stoma, mouth]
1. The aqueous humor. 2. The hyaloid membrane. 3. Relating to the aqueous humor. 4. Watery or resembling water. [G. hydor (hydat-), water, + eidos, resemblance]
Producing a discharge of watery fluid; denoting a class of cathartics that retain fluids in the intestine and aid in the removal of edematous fluids, e.g., saline cathartics. [ ...
11β,17α,21-Trihydroxy-5β-pregnane-3,20-dione; a metabolite of cortisole, reduced at the 4,5 double bond. SYN: 4,5α-dihydrocortisol.
Presence of an excessive amount of amniotic fluid, usually over 2,000 mL. SYN: polyhydramnios. [G. hydor, water, + amnion]
A condition in which the cerebral hemispheres of the brain are absent and replaced by sacs filled with cerebrospinal fluid. Usually the cerebellum and brainstem are formed ...
SYN: mercury. [G. hydrargyros, quicksilver, fr. hydor, water, + argyros, silver]
Effusion of a serous fluid into a joint cavity. [ hydr- + G. arthron, joint]
- intermittent h. a disorder characterized by a periodically recurring serous effusion into the ...
An alkaloid of hydrastis; an isoquinoline chemically related to narcotine. As the hydrochloride, was used locally in the treatment of catarrhal inflammation of the mucous ...
A semisynthetic alkaloid prepared from hydrastine; the hydrochloride has been used in uterine hemorrhage and as an oxytocic; in large doses, it is a powerful depressant of the ...
The dried rhizome of H. canadensis (family Ranunculaceae), a native of the eastern U.S.; formerly used in the treatment of chronic catarrhal states of the mucous membranes and ...
Trivial name applied, together with dehydratase, to certain hydro-lyases (EC 4.2.1.x) catalyzing hydration-dehydration; e.g., fumarate-malate interconversion by fumarate h..
An aqueous solvate (in older terminology, a hydroxide); a compound crystallizing with one or more molecules of water; e.g., CuSO4 5H2O.
Combined with water, forming a hydrate. SYN: hydrous.
1. Chemically, the addition of water; differentiated from hydrolysis, where the union with water is accompanied by a splitting of the original molecule and the water molecule. ...
An organic compound of the general formula RCO–NHNH2; an acyl derivative of hydrazine.
Hydrazine sulfate, an alternative medicine that has been claimed to be a treatment for cancer. It has been used as a first-line agent in cancer therapy and as a treatment for ...
Cleavage of chemical bonds by hydrazine; applied in protein and nucleic acid degradations.
A substance derived from aldehydes and ketones by reaction with hydrazine or a hydrazine derivative to give the grouping R′R″C=N—NHR.
A condition in which the blood volume is increased as a result of an increase in the water content of plasma, with or without a reduction in the concentration of protein; there is ...
Protrusion, through a cleft in the skull, of brain substance expanded into a sac containing fluid. SYN: encephalocystocele, hydrocephalocele, hydroencephalocele. [ hydr- + G. ...
Protrusion, through a defect in the skull, of a sac containing meninges, brain substance, and cerebrospinal fluid.
Rarely used term for internal hydrocephalus. [ hydr- + G. enkephalos, brain]
Relating to the obsolete use of water to treat or cure disease. SYN: hydrotherapeutic. [ hydr- + G. iatrikos, relating to medicine]
Relating to hydrogen in chemical combination.
A negatively charged hydrogen ( i.e., H:−) or a compound of hydrogen in which it assumes a formal negative charge, e.g., sodium borohydride (NaBH4).
The reduced form of ninhydrin. It is often used in conjunction with ninhydrin in the detection of amino or imino groups.
1. Water, watery. 2. Containing or combined with hydrogen. 3. A hydatid. [G. hydor, water]
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 name s usually ...
Any vesicular or bullous eruption. SYN: hidroa. [hydro + G. oon, egg]
- h. aestivale SYN: h. vacciniforme.
- h. puerorum SYN: h. vacciniforme.
- h. vacciniforme a recurrent ...
Absence of thirst for water. [hydro- + G. a- priv. + dipsa, thirst]
Distention of the vermiform appendix with a serous fluid.
A dark brown-red pigment that may be formed when bilirubin is reduced.
An aqueous solution of hydrogen bromide (HBr); its salts are bromides.
A usually symptomless anomaly of the renal calix that is dilated from obstruction of the infundibulum; usually discovered incidentally at pyelography or autopsy; may become ...
A compound containing only hydrogen and carbon.
- Diels h. a phenanthrene derivative obtained by the dehydrogenation of various steroids.
- saturated h. a h. that contains the ...
Accumulation of fluid in the coat around the testis. Small hydroceles tend to disappear by a year of age while larger hydroceles may persist and warrant surgery.
* * *
Excision of a hydrocele by drainage of its fluids and, sometimes partial excision of tunical vaginalis. [ hydrocele + G. ektome, excision]
1. Resembling hydrocephalus. 2. A condition in infants suffering from diarrhea or other debilitating disease, in which there are dehydration and general symptoms resembling ...
Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can compress and damage the ...
What is termed " hydrocephalus ex-vacuo" occurs when there is damage to the brain caused by stroke or injury, and there may be an actual shrinkage of brain substance. Although ...
Hydrocephalus, Macewen sign of
A sign to detect hydrocephalus (and brain abscess). Percussion (tapping) on the skull at a particular spot (near the junction of the frontal, temporal and parietal bones) yields ...
Hydrocephalus, normal pressure (NPH)
Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the brain. The fluid (the CSF) is often under increased pressure which can compress and damage the brain. ...
Also known as hydrocephalus, this is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can ...
HCl; the acid of gastric juice. The commercial product is used as an escharotic; the gas and the concentrated solution are strong irritants. SYN: muriatic acid.
- diluted h. a ...
A compound formed by the addition of a hydrochloric acid molecule to a basic moiety on the substance; e.g., guanine h., glycine h..
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]
Increased output of a watery bile of low specific gravity, viscosity, and solid content. [hydro- + G. chole, bile, + hairesis, a taking]
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.
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 ...
An alkaloidal principle derived from cotarnine; it is the basic hydrolytic product of narcotine; also obtained from the mother liquors of thebaine.
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; ...
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]
The branch of physics concerned with the flow of liquids. [hydro- + G. dynamis, force]
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.
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 ...
The decadic logarithm of the hydrogen ion concentration in blood or other fluid; its negative is the pH of that fluid.
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. ...
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.
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 ...
Addition of hydrogen to a compound, especially to an unsaturated fat or fatty acid; thus, soft fats or oils are solidified or “hardened.”
Pertaining to the motion of fluids and the forces giving rise to such motion.
That branch of kinetics concerned with fluids in motion.
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.
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 ...
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, ...
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]
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.
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]
Distention of the kidney with urine. Due to obstruction of urine outflow (for example, by a stone blocking the ureter, the tube going
* * *
Dilation of the pelvis and calices of ...
Accumulation of serous fluid in the accessory tubes of the oviduct. [hydro- + G. para, beside, + salpinx, trumpet]
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.
Those oxidoreductases that require H2O2 as hydrogen acceptors; e.g., peroxidases, catalase.
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. ...
SYN: rabies. [hydro- + G. phobos, fear; from reports of inability to swallow and resultant resistance to oral fluids in human and animal rabies]
1. Relating to or suffering from hydrophobia. 2. Lacking an affinity for water molecules, as opposed to hydrophilic. SYN: apolar (2). 3. Tending not to dissolve in water. 4. ...
A family of snakes, the true sea snakes, characterized by a vertically compressed tail, giving it a paddle- or oarlike appearance; their fangs, like those of cobras, are small, ...
Containing an excess of water or of watery fluid. SYN: dropsical.
Combined emphysema and edema; the presence of liquid and gas in tissues. [hydro- + G. pneuma, breath, spirit]
The presence of a serous effusion and of gas in the pericardial sac. SYN: pneumohydropericardium. [hydro- + G. pneuma, air, + pericardium]
The presence of gas and serous fluid in the peritoneal cavity. SYN: pneumohydroperitoneum. [hydro- + G. pneuma, air, + peritoneum]
The presence of both gas and fluids in the pleural cavity. SYN: pneumohydrothorax, pneumoserothorax. [hydro- + G. pneuma, air, + thorax]
Water-drinking, a characteristic of animals that ordinarily drink water. [hydro- + G. posis, drinking]
An excessive accumulation of clear, watery fluid in any of the tissues or cavities of the body; synonymous, according to its character and location, with ascites, anasarca, ...
Gross edema (swelling), usually with anemia, of the fetus. It can be due to Rh blood group incompatibility, in which antibodies crossing the placenta from the mother destroy the ...
Presence of purulent urine in the pelvis and calices of the kidney following obstruction of the ureter. [hydro- + G. pyon, pus, + nephrosis]
An antioxidant used in ointments. SYN: hydroquinol, quinol.
A collection of fluid ( hydrocele) around the testis, as in the tunica vaginalis or along the spermatic cord. [hydro- + G. orchis, testicle]
A rheostat in which resistance to the flow of electric current is provided by water.
A profuse discharge of watery fluid from any part of the body. [hydro- + G. rhoia, flow]
- h. gravidae, h. gravidarum discharge of a watery fluid from the vagina during pregnancy.
Accumulation of serous fluid in the fallopian tube, often an end result of pyosalpinx. SYN: hydrops tubae. [hydro- + G. salpinx, trumpet]
- intermittent h. intermittent ...
SYN: anasarca. [hydro- + G. sarx, flesh]
A chronic swelling of the testis complicated with hydrocele. [hydro- + G. sarx, flesh, + kele, tumor]
A colloid in aqueous solution, the particles being in the dispersed or internal phase and the water in the external or dispersion phase. Cf.:hydrogel.
A sphygmograph in which the pulse beat is transmitted to the recorder through a column of water.
A device for regulating water level. [hydro- + G. statikos, causing to stand]
Relating to the pressure of fluids or to their properties when in equilibrium.
SYN: hydrosudotherapy. [hydro- + L. sudor, sweat, + G. pathos, suffering]
Hydrotherapy combined with induced sweating, as in the Turkish bath. SYN: hydrosudopathy.
SYN: syringomyelia. [hydro- + G. hydor, water, + syrinx, a tube, + myelos, marrow]
The movement of cells or organisms in relation to water. [hydro- + G. taxis, arrangement]
Therapeutic use of water by external application, either for its pressure effect or as a means of applying physical energy to the tissues. SYN: hydrotherapeutics. [hydro- + G. ...
Relating to hot water. [hydro- + G. therme, heat]
The presence of hydrogen sulfide in the circulating blood. [hydro- + G. theion, sulfur, + haima, blood]
The excretion of hydrogen sulfide in the urine. [hydro- + G. theion, sulfur, + ouron, urine]
SYN: pleural effusion.
- chylous h. SYN: chylothorax.
In histology, tearing apart the tissue elements by injection of water. [hydro- + G. tome, a cutting]
The property in growing organisms of turning toward a moist surface (positive h.) or away from a moist surface (negative h.). [hydro- + G. tropos, a turning]
Injection of a liquid medication or saline solution through the cervix into the uterine cavity and fallopian tubes for dilation and/or treatment of the tubes.
A collection of fluid in the ovary. SYN: hydrops ovarii.
R—CO—NH—OH ⇄ RC(OH)=N—OH; hydroxylamine derivatives of carboxylic acid s, including amino acid s, formed by the action of hydroxylamine.
1. A compound containing a potentially ionizable hydroxyl group; particularly a compound that liberates OH− upon dissolving in water. 2. The h. anion, OH−.
Vitamin B12b, differing from cyanocobalamin (vitamin B12) in the presence of a hydroxyl ion in place of the cyanide ion at the sixth coordinate position on the cobalt atom. ...
An organic acid containing both OH and COOH groups; e.g., lactic acid.
Prefix indicating addition or substitution of the –OH group to or in the compound whose name follows. SEE ALSO: oxa-, oxo-, oxy-.
An enzyme with catalytic activity similar to that of lactoylglutathione lyase, but more general; catalyzes the hydrolysis of an S-2-hydroxyacylglutathione, producing glutathione ...
A major component and an essential ingredient of normal bone and teeth. Hydroxyapatite makes up bone mineral and the matrix of teeth. It is hydroxyapatite that gives bones and ...
Hydroxyapatite crystal disease
The inflammation caused by hydroxyapatite crystals has been referred to as hydroxyapatite crystal disease. Hydroxyapatite is a major component and an essential ingredient of ...
A quinoline derivative; an antimalarial agent whose actions and uses resemble those of chloroquine phosphate; also used in the treatment of lupus erythematosus and rheumatoid ...
A fatty acid that has a hydroxyl group covalently attached to it ( E.G., in hydroxynervone).
An abnormality in tryptophan metabolism, probably due to a defect in kynureninase, characterized by mild mental retardation, migraine-like headaches, and urinary excretion of ...
1. NH2OH; a partially oxidized derivative of ammonia; reacts with carbonyl groups to produce oximes; forms acid salts, e.g., h. hydrochloride. It is a chemical mutagen that ...
Enzymes catalyzing formation of hydroxyl groups by addition of an oxygen atom, hence oxidizing the substrate; most are found in EC subclass 1.14.
Placing of a hydroxyl group on a compound in a position where one did not exist before.
A cerebroside containing α-hydroxynervonic acid. SYN: oxynervone.
Urinary excretion of tyrosine and phenylalanine, as a result of ascorbic acid deficiency; occurs notably in those premature infants who lack this vitamin.
A metabolic disorder characterized by mental retardation and microscopic hematuria in some patients; associated with enhanced plasma concentration and urinary excretion of free ...
An oral antineoplastic agent that inhibits DNA synthesis; used in the treatment of a variety of malignancies including melanoma, chronic myelocytic leukemia, and carcinoma of ...
A mild sedative and minor tranquilizer used in neuroses; available as the hydrochloride and pamoate. Often used to prevent nausea and to enhance the effects of narcotics.
A class of coelenterates or jellyfishes, including Hydra, a freshwater polyp, Physalia, the “Portuguese man-of-war,” Millepora, a stinging coral, and the sea wasps, Chironex ...
The science of hygiene and sanitation, and the practice thereof. [G. hygieia, health, + -logia]
SYN: hygienist. [G. hygieia, health]
The science of preventive medicine and the preservation of health. From the name of Hygeia, the daughter of Asklepios, the Greek god of medicine (whose staff with entwined ...
Healthful; relating to hygiene; tending to maintain health.
One who is skilled in the science of health and its maintenance. SYN: hygieist.
- dental h. a licensed, professional auxiliary in dentistry who is both an oral health educator ...
Relating to moisture. [G. hygros, moist]
N-Methylproline, the methylbetaine of which is stachydrine.
Moisture, humidity; opposite of xero-. [G. hygros, moist]
A cystic swelling containing a serous fluid, such as housemaid's knee, etc. SYN: hydroma. [hygro- + G. -oma, tumor]
- h. axillare h. of the axillary region.
- cervical h. a ...
Any device for measuring the water vapor in the atmosphere, usually indicating relative humidity directly. [hygro- + G. metron, measure]
Morbid fear of dampness or moisture. [hygro- + G. phobos, fear]
Denoting a substance capable of readily absorbing and retaining moisture; e.g., NaOH, CaCl2.
SYN: sialorrhea. [hygro- + G. stoma, mouth]
Symbol for hydroxylysine or hydroxylysyl ( 5Hyl specifically refers to 5-hydroxylysine).
A lateral extension of the cerebral (or sylvian) aqueduct. [G. hyle, wood]
Morbid fear of forests. [G. hyle, forest, + phobos, fear]
A thin membrane which completely or partially occludes the vaginal opening. The hymen is a fold of mucous membrane usually present at birth at the orifice of the vagina. It is ...
Excision of the hymen. [G. hymen, membrane, + ektome, excision]
1. SYN: membranous. 2. Resembling the hymen.
Illness produced by infection with tapeworms of the genus Hymenolepis.
Common name for tapeworms of the family Hymenolepididae.
A family of tapeworms (order Cyclophyllidea) that includes the medically important genus Hymenolepis. [G. hymen, membrane, + lepis, rind]