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排序方式: 共有253条查询结果,搜索用时 15 毫秒
1.
M Joffe 《BMJ (Clinical research ed.)》1993,306(6893):1629-1630
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Vanessa R. Panz Paul Ruff Barry I. Joffe Mary-Anne Kedda Harold C. Seftel 《Human genetics》1996,97(4):438-440
The frequency of DNA polymorphisms in the tyrosine kinase domain (exons 17–21) of the insulin receptor gene was assessed
in 30 black and 30 white South Africans, using single-stranded conformation polymorphism and direct sequencing analysis. A
comparison of the frequencies of the normal versus the combined polymorphic alleles, found only in exon 17, showed a significant
difference between black and white groups (P = 0.037).
Received: 25 May 1995 / Revised: 1 September 1995 相似文献
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The 5-HT (serotonin) distribution in the nervous system of the macrodasyoid gastrotrich Turbanella cornuta was studied using immunocytochemical methods. Positive immunoreaction was found in two pairs of neurons. The neurons of one pair had processes which extended peripherally to the surface of the body. Central processes of both pairs entered the brain commissure and proceeded into the longitudinal cords. Unlike other acoelomate worms studied so far, the Platyhelminthes and the Nematoda, in this gastrotrich no 5-HT positive perikarya or processes were present in the pharynx innervation, and no positive neurons sent processes directly to the nerve cords 相似文献
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A covalently bound photoisomerizable agonist. Comparison with reversibly bound agonists at electrophorus electroplaques 总被引:2,自引:2,他引:0 下载免费PDF全文
HA Lester ME Krouse MM Nass NH Wassermann BF Erlanger 《The Journal of general physiology》1980,75(2):207-232
After disulphide bonds are reduced with dithiothreitol, trans-3- (α-bromomethyl)-3’-[α- (trimethylammonium)methyl]azobenzene (trans-QBr) alkylates a sulfhydryl group on receptors. The membrane conductance induced by this “tethered agonist” shares many properties with that induced by reversible agonists. Equilibrium conductance increases as the membrane potential is made more negative; the voltage sensitivity resembles that seen with 50 [mu]M carbachol. Voltage- jump relaxations follow an exponential time-course; the rate constants are about twice as large as those seen with 50 μM carbachol and have the same voltage and temperature sensitivity. With reversible agonists, the rate of channel opening increases with the frequency of agonist-receptor collisions: with tethered trans-Qbr, this rate depends only on intramolecular events. In comparison to the conductance induced by reversible agonists, the QBr-induced conductance is at least 10-fold less sensitive to competitive blockade by tubocurarine and roughly as sensitive to “open-channel blockade” bu QX-222. Light-flash experiments with tethered QBr resemble those with the reversible photoisomerizable agonist, 3,3’,bis-[α-(trimethylammonium)methyl]azobenzene (Bis-Q): the conductance is increased by cis {arrow} trans photoisomerizations and decreased by trans {arrow} cis photoisomerizations. As with Bis-Q, ligh-flash relaxations have the same rate constant as voltage-jump relaxations. Receptors with tethered trans isomer. By comparing the agonist-induced conductance with the cis/tans ratio, we conclude that each channel’s activation is determined by the configuration of a single tethered QBr molecule. The QBr-induced conductance shows slow decreases (time constant, several hundred milliseconds), which can be partially reversed by flashes. The similarities suggest that the same rate-limiting step governs the opening and closing of channels for both reversible and tethered agonists. Therefore, this step is probably not the initial encounter between agonist and receptor molecules. 相似文献
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J E Morley C Klein W J Kalk B I Joffe D Saffer L A Distiller H C Seftel 《Hormones et métabolisme》1978,10(3):231-237
The pituitary responses to the intravenous administration of 200 mg of Thyrotropin Releasing Hormone were investigated in 14 poorly controlled insulin dependent diabetic males and in nine matched controls. The mean TSH and prolactin responses in the two groups were similar although both tended to be lower in the diabetics. There was a small FSH rise in 11 of the 23 subjects. 相似文献
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Isolates of Fusarium species obtained from freshly harvested bean grains for human consumption collected from different Argentinean
regions, were investigated for their ability to biosynthesise trichothecenes and zearalenone either on rice grains or beans.
Low incidence of toxigenic fungi was observed. These mycotoxigenic species produced several toxins when grown on rice but
none or little amount when cultured on beans. The results of this report suggest that contamination of Argentinean beans with
Fusarium mycotoxins will not be common and therefore people would be at low mycotoxicosis risk through consumption of beans. 相似文献