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991.
Molecular analysis of DNA and construction of genomic libraries of Mycobacterium leprae. 总被引:30,自引:13,他引:17
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J E Clark-Curtiss W R Jacobs M A Docherty L R Ritchie R Curtiss rd 《Journal of bacteriology》1985,161(3):1093-1102
992.
A Phillips D W Hahn J L McGuire D Ritchie R J Capetola C Bowers K Folkers 《Life sciences》1988,43(11):883-888
ORF 23541 [N-Ac-D-Nal(2)1,D-pCl-Phe2,D-Pal(3)3,Ser4,Nic-Lys5,D-Nic-Lys 6, Leu7, I-Lys8, Pro9,D-Ala10NH2; "Nal-Lys antagonist"] was identified as a potent LHRH antagonist without significant anaphylactoid activity. It blocked ovulation in proestrus rats when administered subcutaneously with an ED50 of 5.8 micrograms/kg. Much higher doses of ORF 23541 than of other antagonists were required to induce a cutaneous anaphylactoid-like reaction. Intradermal administration of ORF 23541 caused an 8.75 x 8.75 mm wheal response with estimated doses of 10.9 and 13.7 micrograms in rats and guinea pigs, respectively. These doses were at least 10 times greater than that required of other LHRH antagonists for the same response. ORF 23541 also did not alter pulmonary function in guinea pigs or dogs when administered intravenously at doses up to 10 mg. These results indicate that ORF 23541 represents a new generation of LHRH antagonists with an improved safety margin. 相似文献
993.
A voltage-gated chloride conductance in rat cultured astrocytes 总被引:4,自引:0,他引:4
P T Gray J M Ritchie 《Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)》1986,228(1252):267-288
Large voltage-dependent outward currents are recorded with the whole-cell patch-clamp technique from rat cultured astrocytes under conditions where an outward movement of potassium ions is excluded (either by blockage of the potassium channels pharmacologically or by replacement of the internal potassium by the impermeant large organic cation N-methyl-(+)-glucamine). The current, which is activated at potentials more positive than -40 to -50 mV, is normally carried by an inward movement of chloride ions. Its reversal potential is the same as the chloride equilibrium potential. With depolarization to +60 mV (for 225 ms) little or no inactivation of the current occurs: with depolarizations to +90 to +110 mV a time-dependent decay is seen. The current, which is often not marked immediately after formation of the whole-cell clamp, generally increases over a period of a few minutes to a maximum (after which it usually declines), as if some as yet unknown intracellular factor keeping the channels closed were being washed away from the membrane. The time course of this phenomenon is not affected by changing of the internal free calcium concentration (from 10(-8)M to 10(-6)M) or by an intracellular mixture of cyclic AMP (1 mM), ATP (4 mM) and Mg+ (2 mM). The conductance is slightly increased when the chloride of the bathing medium is replaced by bromide; is much reduced on replacement by methylsulphate, sulphate, isethionate, or acetate; and is virtually abolished on replacement by the large anion gluconate. The outward current is inhibited by the disulphonate stilbenes DIDS and SITS; this blocking action was initially partly reversible, although never completely so. It is suggested that the chloride conductance plays a role in the spatial buffering of potassium by astrocytes. 相似文献
994.
DNA fingerprints from hypervariable mitochondrial genotypes 总被引:4,自引:0,他引:4
Conventional surveys of restriction-fragment polymorphisms in mitochondrial
DNA of menhaden fish (Brevoortia tyrannus/patronus complex) and chuckwalla
lizards (Sauromalus obesus) revealed exceptionally high levels of genetic
variation, attributable to differences in mtDNA size as well as in
restriction sites. The observed probabilities that any two randomly drawn
individuals differed detectably in mtDNA genotype were 0.998 and 0.983 in
the two species, respectively. Thus, the variable gel profiles provided
unique mtDNA "fingerprints" for most conspecific animals assayed. mtDNA
fingerprints differ from nuclear DNA fingerprints in several empirical
respects and should find special application in the genetic assessment of
maternity.
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995.
Influence of soil water stress on evaporation, root absorption, and internal water status of cotton 总被引:19,自引:14,他引:5
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Diurnal variations in leaf water potential, diffusion resistance, relative water content, stem diameter, leaf temperature, and energy balance components were measured in cotton (Gossypium hirsutum L. var. Lankart 57) during drought stress under field conditions. A plot of leaf water potential against either relative water content or stem diameter during the 24-hour period yielded a closed hysteresis loop. The relation between cell hydration and evaporation is discussed. 相似文献
996.
A variety of adhesives were used at —20 C to attach cryostat sections to cold slides and to allow fixation in the cryostat, thus preventing thawing artefacts. Of a range of adhesives readily available, a natural rubber solution, Romac C33, was found to give optimal results when used at this temperature. By this method histological, histochemical and immunofluorescent techniques could be successfully applied. 相似文献
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Energy-linked activities of the chromaffin granule membrane. 总被引:9,自引:0,他引:9