| hydatiform mole | <radiology> Trophoblastic proliferation with avascularity of chorionic villi, marked oedema and enlargement of chorionic villi, severe eclampsia prior to 24 weeks, 1st trimester bleeding, abnormal elevation of beta-hCG, passing grapelike vesicles per vagina, uterus large for dates (50%), hyperechoic intrauterine tissue interspersed with numerous punctate hypoechoic areas (hydropic villi), in 25% atypical appearance: large hyperechoic areas (blood clots) and areas of cystic degeneration; resembles incomplete abortion, thick hyperechoic rim around central anechoic zone, bilateral theca lutein cysts (18-37%) see also: gestational trophoblastic disease, hydatiform mole: types (12 Dec 1998) |
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| hydatiform mole: types | <radiology> Complete/classical mole, fertilization of an empty egg; diploid karyotype (paternal XX), no foetal parts; no chorionic membrane, 20% malignant complete mole with coexistent foetus (2%), molar degeneration of an identical twin partial mole, areas of molar change alternating with normal chorionic villi, triploid karyotype (66% XXY; 33% XXX), early onset of preeclampsia, foetal structures present (e.g., placenta), no malignant potential see: hydatiform mole (12 Dec 1998) |
| Hydatigera taeniaeformis | One of the common tapeworms of household cats; the larval form is called Cysticercus fasciolaris. Synonym: Hydatigera taeniaeformis, Taenia crassicollis. (05 Mar 2000) |
| hydatoid | <anatomy> Resembling water; watery; aqueous; hyaloid. Origin: Gr. "ydwr, "ydatos, water. Source: Websters Dictionary (01 Mar 1998) |
| Hyde | James N., U.S. Dermatologist, 1840-1910. See: Hyde's disease. (05 Mar 2000) |
| Hyde's disease | An eruption of hard nodules (Picker's nodules) in the skin caused by rubbing and accompanied by intense itching. Synonym: Hyde's disease. (05 Mar 2000) |
| hydnocarpus oil | The fixed oil expressed from seeds of Taraktogenos kurzii and Hydnocarpus wightiana (family Flacourtiaceae); formerly used in the treatment of leprosy. Synonym: gynocardia oil, hydnocarpus oil. (05 Mar 2000) |
| hydr- | 1. <prefix> A combining form from the Greek term for water. 2. <chemistry> A combining form of hydrogen, indicating hydrogen as an ingredient, as hydrochloric; or a reduction product obtained by hydrogen, as hydroquinone. (29 Oct 1998) |
| Hydra | <organism> Genus of freshwater coelenterates (cnidarians). They are small, solitary and only exist in the polyp form, which is a radially symmetrical cylinder that is attached to the substratum at one end and has a mouth surrounded by tentacles at the other. They have considerable powers of regeneration and have been used in studies on positional information in morphogenesis. (18 Nov 1997) |
| hydracetin | Pure form of acetylphenylhydrazine. (05 Mar 2000) |
| hydrachnid | <zoology> An aquatic mite of the genus Hydrachna. The hydrachids, while young, are parasitic on fresh water mussels. Origin: Hydr- + arachnid. Source: Websters Dictionary (01 Mar 1998) |
| hydracid | <chemistry> An acid containing hydrogen; sometimes applied to distinguish acids like hydrochloric, hydrofluoric, and the like, which contain no oxygen, from the oxygen acids or oxacids. See Acid. Origin: Hydr- + acid: cf. F. Hydracide. Source: Websters Dictionary (01 Mar 1998) |
| hydracrylic | <chemistry> Pertaining to, or designating, an isomeric variety of lastic acid that breaks down into acrylic acid and water. Origin: Hydr- + acrylic. Source: Websters Dictionary (01 Mar 1998) |
| hydractinian | <zoology> Any species or marine hydroids, of the genus Hydractinia and allied genera. These hydroids form, by their rootstalks, a firm, chitinous coating on shells and stones, and especially. On spiral shells occupied by hermit crabs. See: Hydra, and Actinia. Source: Websters Dictionary (01 Mar 1998) |
| hydradenitis | The inflammation of a sweat gland (usually of the apocrine type). The condition can be idiopathic or occur as a result of or in association with another underlying condition. Neutrophilic eccrine hidradenitis is a relatively rare variant that has been reported in patients undergoing chemotherapy, usually for non-hodgkin lymphomas or leukaemic conditions. (12 Dec 1998) |