| black line | The linea alba in pregnancy, which then becomes pigmented. Synonym: black line. (05 Mar 2000) |
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| black lung | A form of chronic clung disease which develops after prolonged exposure to coal dust. Advanced disease and scarring is evident on chest X-ray. Symptoms include wheezing, chronic cough and shortness of breath. (27 Sep 1997) |
| black measles | An acute tick-borne illness caused by the bacteria Rickettsia rickettsii. The disease is characterised by sudden onset of headache, chills and fever which can persist for 2-3 weeks. A characteristic rash appears on the extremities and trunk about the 4th day of illness. (27 Sep 1997) |
| black membrane | <chemistry> An artificial phospholipid membrane formed by painting a solution of phospholipid in organic solvent over a hole in a hydrophobic support immersed in water. Drainage of the solvent from the film produces diffraction colours until the thickness falls below the wavelength of light it then appears to be black. The structure is an extended bimolecular leaflet. (18 Nov 1997) |
| black mustard | The dried ripe seed of Brassica nigra or of B. Juncea; it is the source of allyl isothiocyanate; it contains sinigrin (potassium myronate); myrosin; sinapine sulfocyanate; erucic, behenic, and synapolic acids; and fixed oil; a prompt emetic, a rubefacient, and a condiment. (05 Mar 2000) |
| black piedra | Piedra involving the hairs of the scalp, caused by Piedraia hortae and characterised by firmly adherent black, hard, gritty nodules composed of an organised, firmly cemented mass of fungus cells; the fungal growth is always located above the level of the hair follicles; the disease occurs in humid tropical countries of the Americas, Africa, Southeast Asia, and Indonesia, and attacks chimpanzees and other primates as well as humans. (05 Mar 2000) |
| black plague | In 14th-century Europe, the victims of the black plague had bleeding below the skin (subcutaneous haemorrhage) which made darkened ( blackened ) their bodies. Black plague can lead to black death characterised by gangrene of the fingers, toes, and nose. Black plague is caused by a bacterium (Yersinia pestis) which is transmitted to humans from infected rats by the oriental rat flea. (12 Dec 1998) |
| black pudding | A kind of sausage made of blood, suet, etc, thickened with meal. "And fat black puddings, proper food, For warriors that delight in blood." (Hudibras) Source: Websters Dictionary (01 Mar 1998) |
| black root | <botany> Dried rhizome and roots of Veronicastrum virginicum (family Serophulariaceae). Indigenous to North America. Formerly used as a cathartic. Synonym: black root, Culver's root. (05 Mar 2000) |
| Black's classification | A classification of cavities of the teeth based upon the tooth surface(s) involved. (05 Mar 2000) |
| Black's formula | A translation of Pignet's formula into British measurements: F = (W + C) -H; F is the empirical factor, W is the weight in pounds, C the chest girth in inches at full inspiration, and H the height in inches; a man is classed as very strong when F is over 120, strong between 110 and 120, good 100 to 110, fair 90 to 100, weak 80 to 90, very weak under 80. (05 Mar 2000) |
| black sickness | A chronic disease, occurring in India, Assam, China, the area formerly known as the Mediterranean littoral areas, the Middle East, India, Pakistan, China, South and Central America, Asia, Africa caused by Leishmania donovani and transmitted by the bite of an appropriate species of sandfly of the genus Phlebotomus or Lutzomyia; the organisms grow and multiply in macrophages, eventually causing them to burst and liberate amastigote parasites which then invade other macrophages; proliferation of macrophages in the bone marrow causes crowding out of erythroid and myeloid elements, resulting in leukopenia, and anaemia, splenomegaly, and hepatomegaly which are characteristic, along with enlargement of lymph nodes; fever, fatigue, malaise, and secondary infections also occur; different strains of leishmaniasis donovani occur; leishmaniasis infantum in Eurasia, leishmaniasis chagasi in Latin America. Synonym: Assam fever, black sickness, Burdwan fever, cachectic fever, Dumdum fever, kala azar, tropical splenomegaly. (05 Mar 2000) |
| black smoker | An undersea thermal vent emitting very hot (270-380 degrees C) water and minerals. (09 Oct 1997) |
| black spore | A degenerating malarial or other blood parasite in the body of the mosquito. (05 Mar 2000) |
| black tarantula | Sericopelma communis, a large black tarantula of Panama and the Canal Zone, whose bite is poisonous, although the effect is localised. (05 Mar 2000) |