| hay | Grass cut and cured for fodder. "Make hay while the sun shines." (Camden) "Hay may be dried too much as well as too little." (C. L. Flint) Hay cap, a canvas covering for a haycock. <medicine> Hay fever, nasal catarrh accompanied with fever, and sometimes with paroxysms of dyspnoea, to which some persons are subject in the spring and summer seasons. It has been attributed to the effluvium from hay, and to the pollen of certain plants. It is also called hay asthma, hay cold, and rose fever. Hay knife, a sharp instrument used in cutting hay out of a stack or mow. Hay press, a press for baling loose hay. Hay tea, the juice of hay extracted by boiling, used as food for cattle, etc. Hay tedder, a machine for spreading and turning newmown hay. Origin: OE. Hei, AS. Hg; akin to D. Kooi, OHG. Hewi, houwi, G. Heu, Dan. & Sw. Ho, Icel. Hey, ha, Goth. Hawi grass, fr. The root of E. Hew. See Hew to cut. Source: Websters Dictionary (01 Mar 1998) |
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| hay bacillus | <bacteria> Bacillus subtilis is a Gram-positive, rod-shaped, nonpathogenic bacterium which lives in soil. Its genome has been widely studied and is frequently used in genetic engineering and microbiology experiments. (09 Oct 1997) |
| hay fever | <chest medicine> An inflammatory response in the nasal passages to an allergic stimulus. Often includes: nasal congestion, sneezing, runny or itchy nose. (27 Sep 1997) |
| haybird | <zoology> The European spotted flycatcher. The European blackcap. Source: Websters Dictionary (01 Mar 1998) |
| haye | <zoology> The Egyptian asp or cobra (Naja haje) It is related to the cobra of India, and like the latter has the power of inflating its neck into a hood. Its bite is very venomous. It is supposed to be the snake by means of whose bite Cleopatra committed suicide, and hence is sometimes called Cleopatra's snake or asp. See Asp. Origin: Ar. Hayya snake. Source: Websters Dictionary (01 Mar 1998) |
| Hayem's haematoblast | <haematology> A discoid cell (3m diameter) found in large numbers in blood, important for blood coagulation and for haemostasis by repairing breaches (small breaks) in the walls of blood vessels. Platelet _ granules contain lysosomal enzymes, dense granules contain ADP (a potent platelet aggregating factor) and serotonin (a vasoactive amine). They also release platelet-derived growth factor which presumably contributes to later repair processes by stimulating fibroblast proliferation. Synonym: thrombocytes. (09 Oct 1997) |
| Hayem's solution | <haematology> A blood diluent used prior to counting red blood cells. (05 Mar 2000) |
| Hayem, Georges | <person> French physician, 1841-1933. See: Hayem's haematoblast, Hayem's solution, Hayem-Widal syndrome. (05 Mar 2000) |
| Hayem-Widal syndrome | <clinical sign> An obsolete term for acquired haemolytic icterus. Synonym: Widal's syndrome. (05 Mar 2000) |
| Hayflick's limit | <cell culture> The limit of human cell division in subcultures; such cells will divide only about 50 times before dying out. (05 Mar 2000) |
| Hayflick, Leonard | <person> U.S. Microbiologist, *1928. See: Hayflick's limit. (05 Mar 2000) |
| Haygarth's nodes | <anatomy> Exostoses from the margins of the articular surfaces and from the periosteum and bone in the neighborhood of the joints of the fingers, leading to ankylosis and associated with lateral deflection of the fingers toward the ulnar side, which occur in rheumatoid arthritis. Synonym: Haygarth's nodosities. (05 Mar 2000) |
| Haygarth's nodosities | <anatomy> Exostoses from the margins of the articular surfaces and from the periosteum and bone in the neighborhood of the joints of the fingers, leading to ankylosis and associated with lateral deflection of the fingers toward the ulnar side, which occur in rheumatoid arthritis. Synonym: Haygarth's nodosities. (05 Mar 2000) |
| Haygarth, John | <person> English physician, 1740-1827. See: Haygarth's nodes, Haygarth's nodosities. (05 Mar 2000) |
| timothy-hay bacillus | A saprophytic bacterium widely distributed in soil and dust and on plants. (12 Dec 1998) |
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