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991.
Effects of opioid blockade with nalmefene in older impotent men 总被引:2,自引:0,他引:2
We evaluated the effect of the opioid antagonist nalmefene on the HPG axis and on food consumption in 14 older impotent men. These patients had low to low normal mean serum testosterone values and normal gonadotrophin levels on screening evaluation. Normal response to GnRH was demonstrated in all the men. The protocol called for 24 hours of evaluation before and during administration of nalmefene 2.0 mg IV every 8 hours for 3 doses. During each 24 hour period, the following determinations were made: serum testosterone, FSH, and LH by five separate determinations between 8 AM and noon; 8 AM and 11 PM serum cortisols; 24 hour urine collections for free cortisol; and nocturnal penile tumescence (NPT). Food consumption was measured from 4 PM to 10 AM during the two periods. Nalmefene resulted in significant rises in testosterone, LH, and FSH. Nalmefene significantly elevated morning and evening cortisol measurements in all the patients. Nalmefene decreased total calorie consumption, principally by decreasing fat consumption. There was no effect on NPT. We conclude that in older impotent men, nalmefene acutely increases activity of the HPG axis and decreases calorie intake predominantly by decreasing fat consumption. 相似文献
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Jill S. Marty James P. Higham Elizabeth L. Gadsby Caroline Ross 《International journal of primatology》2009,30(6):807-823
Sexual selection has driven the evolution and elaboration of a wide variety of displays and ornaments in male nonhuman primates,
including capes, cheek flanges, and sexual coloration. Among the most sexually dimorphic of all primates is the drill (Mandrillus leucophaeus), the males of which can be 3 times the mass of females, possess large canines, and exhibit extremely bright sexual skin
coloration. However, the function of male coloration in this species has never been examined. Here, we present data on male
color (measured objectively using digital photography), dominance rank, measures of male-female association, and key sexual
behaviors, of adult male drills (n = 17) living in four semi free-ranging enclosures at the Drill Rehabilitation and Breeding Center in Nigeria. We test the
hypothesis that male coloration is a badge of status, indicating dominance rank, and the hypothesis that male coloration attracts
females. We found that male coloration did indicate rank, and that high ranking, strongly colored males were more likely to
associate with adult females, and more specifically with fully tumescent females. These males also engaged in more sexual
activity. However, measures of male-female association and sexual behaviors were not related to male color once rank had been
taken into consideration; i.e., for males of a given rank, females did not prefer those that were more colorful. We discuss
the results in light of what is known about the wild drill social system, in which unfamiliar individuals may come together
in “supergroups,” and in which quality indicators of competitive ability may be particularly important. 相似文献
999.
Expanded thermal niche for a diving vertebrate: A leatherback turtle diving into near-freezing water
Michael C. James Graeme C. Hays 《Journal of experimental marine biology and ecology》2006,335(2):221-226
The global distribution of extant reptiles is more limited than that of mammals or birds, with low reptilian species diversity at high latitudes. Central to this limited geographical distribution is the ectothermic nature of reptiles, which means that they generally become torpid at cold temperatures. However, here we report the first detailed telemetry from a leatherback turtle (Dermochelys coriacea) diving in cold water at high latitude. An individual equipped with a satellite tag that relayed temperature-depth profiles dived continuously for many weeks into sub-surface waters as cold as 0.4 °C. Global warming will likely increase the foraging range of leatherback turtles further into temperate and boreal waters. 相似文献
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Human erythrocyte and brain acetylcholinesterase are preferentially inhibited by the P(-)-isomers of C(+/-)P(+/-)-soman. The enzymes inhibited by the P(-)-isomers behave similarly with respect to oxime-induced reactivation and aging. HI-6 is the best reactivator for C(+)P(-)-soman-inhibited acetylcholinesterases. Oxime-induced reactivation of the C(-)P(-)-soman-inhibited acetylcholinesterases is much more difficult to achieve. 相似文献