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The histamine content of rat peritoneal fluid cells is doubled within 20 min by 0.5 microgram/ml of compound 48/80. Histamine catabolism inhibitors do not reproduce this effect; cells pre-incubated with alpha-fluoromethylhistidine are unresponsive to compound 48/80 which therefore activates pre-formed histidine decarboxylase rather than 'inducing' it. Non-mast cells showed no change after treatment with compound 48/80. 相似文献
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Life in extreme environments 总被引:46,自引:0,他引:46
Each recent report of liquid water existing elsewhere in the Solar System has reverberated through the international press and excited the imagination of humankind. Why? Because in the past few decades we have come to realize that where there is liquid water on Earth, virtually no matter what the physical conditions, there is life. What we previously thought of as insurmountable physical and chemical barriers to life, we now see as yet another niche harbouring 'extremophiles'. This realization, coupled with new data on the survival of microbes in the space environment and modelling of the potential for transfer of life between celestial bodies, suggests that life could be more common than previously thought. Here we examine critically what it means to be an extremophile, and the implications of this for evolution, biotechnology and especially the search for life in the Universe. 相似文献
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Zusammenfassung Es wird durchin vitro-Anaphylaxie an Rattenzwerchfell und Meerschweinchenlunge gezeigt, dass die Freisetzung von Histamin durch Dinitrophenol, Cyanid und Sauerstoffmangel gehemmt wird. Diese Hemmung kann aber durch Zufügen von Glukose durchbrochen werden. Die anaphylaktische Freisetzung von Histamin ist also an stoffwechselaktive Mastzellen gebunden. 相似文献
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A bitter tasting cyanoglucoside, sarmentosin, was isolated from an aposematic Apollo butterfly,Parnassius phoebus, and from its plant-host,Sedum stenopetalum. The content of sarmentosin in the body tissues was as high as 500 g/insect, suggesting a defensive role for this substance; a high concentration was detected in the wings. Sarmentosin was also present in the eggs. 相似文献
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The age and origins of the organisms that cause syphilis (treponemes) have long been matters for controversy. The widely-held belief that Columbus's ship brought the disease from the New World to Europe rests on identification of the classic lesions in Inca, Aztec and Mississippian bones that date from 1,000 to 3,000 years before present. But these were not confirmed by immunological techniques. We have observed lesions characteristic of treponemal infection in a Pleistocene bear from Indiana (dated 11,500 years BP) which give a positive result when tested with the antisera used by the US Center for Disease Control for verification of syphilis infection. This is the earliest detection of treponemal disease using contemporary techniques. 相似文献