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Medical Dictionary


hydroxylamino (hi-drok′sil-am-i-no)
The monovalent group or moiety, &cbond;NH&cbond;OH.

hydroxylapatite (hi-drok′sil-ap-a-tit)
SYN: hydroxyapatite.

hydroxylases (hi-drok′si-la-sez)
Enzymes catalyzing formation of hydroxyl groups by addition of an oxygen atom, hence oxidizing the substrate; most are found in EC subclass 1.14.

hydroxylation (hi-drok-si-la′shun)
Placing of a hydroxyl group on a compound in a position where one did not exist before.

5-hydroxylysine (5Hyl)
A hydroxylated amino acid found in certain collagens. The decreased ability to form h. is associated with Ehlers-Danlos syndrome type VI. SYN: δ-hydroxylysine.

SYN: β-hydroxy-β-methylglutaryl-CoA.

hydroxynervone (hi-drok-se-ner′von)
A cerebroside containing α-hydroxynervonic acid. SYN: oxynervone.

hydroxynervonic acid (hi-drok′se-ner-von′ik)
An important constituent of certain cerebrosides.

hydroxyphenyluria (hi-drok′se-fen-il-oo′re-a)
Urinary excretion of tyrosine and phenylalanine, as a result of ascorbic acid deficiency; occurs notably in those premature infants who lack this vitamin.

SYN: deoxycorticosterone.

3-hydroxyproline (3Hyp) (hi-drok′se-pro′len)
A derivative of proline found in certain collagens, particularly basement membrane collagen. SYN: 3-hydroxy-2-pyrrolidinecarboxylic acid.

4-hydroxyproline (4Hyp, Hyp)
4-Hydroxy-2-pyrrolidinecarboxylic acid;the trans-l-isomer is a pyrrolidine found among the hydrolysis products of collagen; not found in proteins other than those of connective tissue. A vitamin C deficiency will result in impaired formation of hydroxyproline. 4-hydroxyproline oxidase 1. a flavoenzyme that catalyzes the conversion of h. to Δ′-pyrroline-3-hydroxy-5-carboxylate using FAD; this enzyme appears to be deficient in individuals with hyperhydroxyprolinemia; 2. an enzyme that catalyzes the reaction of h. with NAD+ to form NADH and 4-oxoproline. SYN: 4-oxoproline reductase.

hydroxyprolinemia (hi-drok′se-pro-li-ne′me-a) [MIM*237000]
A metabolic disorder characterized by mental retardation and microscopic hematuria in some patients; associated with enhanced plasma concentration and urinary excretion of free hydroxyproline because of a deficiency of hydroxyproline oxidase; autosomal recessive inheritance.

15-hydroxyprostaglandin dehydrogenase (hi-drok′se-pros-ta-glan′din)
An enzyme that catalyzes the oxidation of prostaglandins, rendering them inactive, by converting the 15-hydroxyl group to a keto group using NAD+.

SYN: hypoxanthine.

3-hydroxy-2-pyrrolidinecarboxylic acid
SYN: 3-hydroxyproline.

8-hydroxyquinoline (hi-drok-se-kwin′o-lin)
A fungistat and chelating agent. SYN: quinolinol.

hydroxystilbamidine isethionate (hi-drok′se-stil-bam′i-den)
An antifungal and antiprotozoan agent used in the treatment of the nonprogressive cutaneous form of blastomycosis.

hydroxytoluic acid (hi-drok′se-to-loo′ik)
SYN: mandelic acid.

5-hydroxytryptamine (5-HT) (hi-drok-se-trip′ta-men)
SYN: serotonin.

hydroxytryptophan decarboxylase (hi-drok-se-trip′to-fan)
SYN: aromatic d-amino acid decarboxylase.

3-hydroxytyramine (hi-drok-se-ti′ra-men)
SYN: dopamine.

hydroxyurea (hi-drok′se-u-re′a)
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 the ovary. SYN: hydroxycarbamide.

hydroxyzine (hi-drok′si-zen)
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.

Hydrozoa (hi-dro-zo′a)
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 heckeri and Chiropsalmus quadrigatus, whose stings can cause severe wheals, pain, and skin necrosis, and occasionally rapid death from respiratory and cardiac depression. [hydro- + G. zoon, animal]

hygieiology (hi-je-yol′o-je)
The science of hygiene and sanitation, and the practice thereof. [G. hygieia, health, + -logia]

hygieist (hi′je-ist)
SYN: hygienist. [G. hygieia, health]

hygiene (hi′jen)
1. The science of health and its maintenance. 2. Cleanliness that promotes health and well being, especially of a personal nature. [G. hygieinos, healthful, fr. hygies, healthy] criminal h. obsolete term for the branch of mental h. or penology devoted to the study of the causes and prevention of criminality and the treatment of criminals. industrial h. practices adopted by an industrial concern to minimize occupation-related disease and/or injury. mental h. the science and practice of maintaining and restoring mental health; a branch of early twentieth century psychiatry that has become an interdisciplinary field including subspecialties in psychology, nursing, social work, law, and other professions. oral h. the cleaning of the mouth by means of brushing, flossing, irrigating, massaging, or the use of other devices. SEE ALSO: oral physiotherapy.

hygienic (hi-jen′ik, hi-je-en′ik)
Healthful; relating to hygiene; tending to maintain health.

hygienist (hi-je′nist, hi′je-en-ist)
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 and clinician, and who uses preventive, therapeutic, and educational methods for the control of oral diseases.

See hygro-.

hygric (hi′grik)
Relating to moisture. [G. hygros, moist]

hygric acid
N-Methylproline, the methylbetaine of which is stachydrine.

hygro-, hygr-
Moisture, humidity; opposite of xero-. [G. hygros, moist]

hygroma (hi-gro′ma)
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 benign cystic overgrowth of lymphatics of the neck, present at birth, which may form a large tumor-like mass. SYN: h. colli cysticum. h. colli cysticum SYN: cervical h.. cystic h. fetal malformation of fluid accumulations, usually around the neck and shoulders; may be simple or complex; often associated with Turner syndrome. subdural h. accumulation in the subdural space of proteinaceous fluid, usually derived from serum, or of cerebrospinal fluid due to a tear in the arachnoid membrane.

hygrometer (hi-grom′e-ter)
Any device for measuring the water vapor in the atmosphere, usually indicating relative humidity directly. [hygro- + G. metron, measure]

hygrometry (hi-grom′e-tre)
SYN: psychrometry.

hygrophobia (hi-gro-fo′be-a)
Morbid fear of dampness or moisture. [hygro- + G. phobos, fear]

hygroscopic (hi-gro-skop′ik)
Denoting a substance capable of readily absorbing and retaining moisture; e.g., NaOH, CaCl2.

hygrostomia (hi′gro-sto′me-a)
SYN: sialorrhea. [hygro- + G. stoma, mouth]

Symbol for hydroxylysine or hydroxylysyl (5Hyl specifically refers to 5-hydroxylysine).

Abbreviation for 5-hydroxylysine.

hyla (hi′la)
A lateral extension of the cerebral (or sylvian) aqueduct. [G. hyle, wood]

hylephobia (hi-le-fo′be-a)
Morbid fear of forests. [G. hyle, forest, + phobos, fear]

hymen (hi′men) [TA]
A thin membranous fold highly variable in appearance which partly occludes the ostium of the vagina prior to its rupture (which may occur for a variety of reasons). It is frequently absent (even in virgins) although remnants are commonly present as hymenal caruncula tags. [G. h., membrane] h. bifenestratus, h. biforis a h. in which there are two openings separated by a wide septum. Cf.:septate h.. cribriform h. a h. with a number of small perforations. denticulate h. a h. with markedly serrated edges. imperforate h. a h. in which there is no opening, the membrane completely occluding the vagina. infundibuliform h. a projecting, funnel-shaped h. with a central opening with sloping edges. h. sculptatus a h. with markedly uneven and ragged edges. septate h. a h. in which there are two openings separated by a narrow band of tissue. Cf.:h. bifenestratus. h. subseptus a h. in which the opening is partly closed by a septum. vertical h. a h. in which the opening is perpendicular.

hymenal (hi′men-al)
Relating to the hymen.

hymenectomy (hi-me-nek′to-me)
Excision of the hymen. [G. hymen, membrane, + ektome, excision]

hymenitis (hi-me-ni′tis)
Inflammation of the hymen.

hymenoid (hi′men-oyd)
1. SYN: membranous. 2. Resembling the hymen.

hymenolepiasis (hi′me-no-le-pi′a-sis)
Illness produced by infection with tapeworms of the genus Hymenolepis.

hymenolepidid (hi′men-o-lep′i-did)
Common name for tapeworms of the family Hymenolepididae.

Hymenolepididae (hi′men-o-lep′i-did-e)
A family of tapeworms (order Cyclophyllidea) that includes the medically important genus Hymenolepis. [G. hymen, membrane, + lepis, rind]

Hymenolepis (hi-me-nol′e-pis)
The largest genus (family Hymenolepididae) of tapeworms in the order Cyclophyllidea; especially common parasites of rodents, shrews, and aquatic birds. [G. hymen, membrane, + lepis, rind] H. diminuta a tapeworm species of rats and mice, rarely found in man; its cysticercoid larvae are harbored by beetles, fleas, caterpillars, and other insects. H. lanceolata a tapeworm of aquatic birds, rarely found in humans. H. nana the dwarf or dwarf mouse tapeworm; a small tapeworm of man, sometimes found in great numbers in the intestine; the cysticercoid can develop by two pathways: in the final host, with the egg from one human directly infective to another human host, in which both larval and adult stages occur, or through two hosts, an insect (or crustacean) intermediate and a vertebrate final host, the obligate two-host cycle of most cyclophylidean cestodes; in addition, H. nana can internally reinfect the same human or rodent host, producing a massive reinfection. H. nana, fraterna a race, strain, or subspecies of H. nana adapted to mice, although infectivity to humans may remain; the human form, H. nana, presumably is derived from the rodent strain.

hymenology (hi-me-nol′o-je)
The branch of anatomy and physiology concerned with the membranes of the body. [G. hymen, membrane, + logos, study]

Hymenoptera (hi-me-nop′ter-a)
An order of insects, including bees, wasps, and ants, characterized by locked pairs of membranous wings and high development of social or colonial behavior. [G. hymen, membrane, + pteron, wing]

hymenorrhaphy (hi-me-nor′a-fe)
Obsolete procedure of suturing the hymen in order to close the vagina. [G. hymen, membrane, + raphe, a suture]

hymenotomy (hi-me-not′o-me)
Surgical division of a hymen. [G. hymen, membrane, + tome, incision]

Wilfred, British plastic surgeon, *1903.

U-shaped, hyoid. [G. hyoeides, shaped like the letter upsilon, Υ]

hyoepiglottic (hi′o-ep-i-glot′ik)
Relating to the hyoid bone and the epiglottis; denoting the elastic h. ligament connecting the two structures. SYN: hyoepiglottidean.

hyoepiglottidean (hi′o-ep-i-glo-tid′e-an)
SYN: hyoepiglottic.

hyoglossal (hi′o-glos′al)
Relating to the hyoid bone and the tongue. SYN: glossohyal.

hyoglossus (hi′o-glos′us)
SYN: h. (muscle).

hyoid (hi′oyd)
U-shaped or V-shaped; denoting the h. bone and the h. apparatus. [G. hyoeides, shaped like the letter upsilon, Υ]

hyopharyngeus (hi′o-far′in-je′us)
See middle constrictor (muscle) of pharynx.

hyoscine (hi′o-sen)
SYN: scopolamine. h. hydrobromide SYN: scopolamine hydrobromide.

hyoscyamine (hi-o-si′a-men)
An alkaloid found in hyoscyamus, belladonna, duboisine, and stramonium; the levorotatory component of the racemic mixture, atropine; used as an antispasmodic, analgesic, and sedative; h. hydrobromide is used for the same purposes. SYN: daturine. h. sulfate an antispasmodic, hypnotic, and sedative, also used in parkinsonism to relieve tremor, rigidity, and excessive salivation.

hyoscyamus (hi-o-si′a-mus)
The leaves and flowering tops of H. niger (family Solanaceae); it contains hyoscyamine and hyoscine (scopolamine); an anticholinergic and antispasmodic. SYN: henbane. [G. hyoskyamos, henbane or hog's bean, fr. hys, gen. hyos, a hog, + kyamos, a bean]

hyothyroid (hi′o-thi′royd)
See thyrohyoid membrane.

Abbreviation for hypoxanthine; hydroxyproline (3Hyp and 4Hyp specifically refer to 3-hydroxyproline and 4-hydroxyproline, respectively).

Abbreviation for 3-hydroxyproline.

Abbreviation for 4-hydroxyproline.

Variation of the prefix hypo-, often used before a vowel. Cf.:sub-.

hypacusia (hi′pa-koo′ze-a, hip′a-)
SYN: hypacusis.


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