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G.Christian Friesinger Oswald Oelz Brian J. Sweetman Alan S. Nies Joann L. Data 《Prostaglandins & other lipid mediators》1978,15(6):969-981
Prostaglandin (PG) D2 was biosynthesized by rabbit renal papillae incubates in vitro. Quantification of the renal prostaglandins by gas chromatography-mass spectroscopy demonstrated that the concentration of PGD2 generated by renal papillae was
to
the amount of PGE2 or about 1 μg/g tissue/30 min. Infusion of the sodium salt of PGD2 into the renal artery of the dog produced a dose related increase in renal blood flow and urine flow, free water clearance, sodium excretion and potassium excretion without changes in systemic hemodynamics. At low doses PGD2 increased renal blood flow to all cortical zones. Higher concentrations of PGD2 produced a shift in the intrarenal distribution of blood flow toward the juxtamedullary nephrons. 相似文献
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Heterogeneity of holocarboxylase synthetase in patients with biotin-responsive multiple carboxylase deficiency. 总被引:3,自引:0,他引:3 下载免费PDF全文
Holocarboxylase synthetase activity has been determined in fibroblasts of seven patients with the neonatal form of biotin-responsive multiple carboxylase deficiency. The normal Km for biotin was 15 +/- 3 nmol/l, while in the patients the values ranged from 48 to 1,062 nmol/l. The mean maximum velocity was 27% of normal. Differences among the values obtained for the Km for biotin and the heat stability of holocarboxylase synthetase suggested that the patients studied represented at least four distinct variants at the holocarboxylase synthetase locus. 相似文献
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Nutrient limitation of phytoplankton communities in Subarctic lakes and ponds in Wapusk National Park, Canada 总被引:1,自引:0,他引:1
We determined the limiting nutrient of phytoplankton in 21 lakes and ponds in Wapusk National Park, Canada, using nutrient
enrichment bioassays to assess the response of natural phytoplankton communities to nitrogen and phosphorus additions. The
goal was to determine whether these Subarctic lakes and ponds were nutrient (N or P) limited, and to improve the ability to
predict future impacts of increased nutrient loading associated with climate change. We found that 38% of lakes were not limited
by nitrogen or phosphorus, 26% were co-limited by N and P, 26% were P-limited and 13% were N-limited. TN/TP, DIN/TP and NO3
−/TP ratios from each lake were compared to the Redfield ratio to predict the limiting nutrient; however, these predictors
only agreed with 29% of the bioassay results, suggesting that nutrient ratios do not provide a true measure of nutrient limitation
within this region. The N-limited lakes had significantly different phytoplankton community composition with more chrysophytes
and Anabaena sp. compared to all other lakes. N and P limitation of phytoplankton communities within Wapusk National Park lakes and ponds
suggests that increased phytoplankton biomass may result in response to increased nutrient loading associated with environmental
change. 相似文献
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There is a need for safe medications that can effectively support recovery by treating symptoms of protracted abstinence that may precipitate relapse in alcoholics, e.g. craving and disturbances in sleep and mood. This proof-of-concept study reports on the effectiveness of gabapentin 1200 mg for attenuating these symptoms in a non-treatment-seeking sample of cue-reactive, alcohol-dependent individuals. Subjects were 33 paid volunteers with current Diagnostic and Statistical Manual of Mental Disorders-IV alcohol dependence and a strength of craving rating 1 SD or greater for alcohol than water cues. Subjects were randomly assigned to gabapentin or placebo for 1 week and then participated in a within-subjects trial where each was exposed to standardized sets of pleasant, neutral and unpleasant visual stimuli followed by alcohol or water cues. Gabapentin was associated with significantly greater reductions than placebo on several measures of subjective craving for alcohol as well as for affectively evoked craving. Gabapentin was also associated with significant improvement on several measures of sleep quality. Side effects were minimal, and gabapentin effects were not found to resemble any major classes of abused drugs. Results suggest that gabapentin may be effective for treating the protracted abstinence phase in alcohol dependence and that a randomized clinical trial would be an appropriate next step. The study also suggests the value of cue-reactivity studies as proof-of-concept screens for potential antirelapse drugs. 相似文献
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Industrial microbiology of solar salt production 总被引:3,自引:0,他引:3
Javor BJ 《Journal of industrial microbiology & biotechnology》2002,28(1):42-47
Solar salterns can be modeled as giant outdoor chemostats, much like a series of dams on a slow-moving river. Microorganisms
and their products play an essential, but sometimes uncharacterized, role in salt production in these ponds, from seawater
salinity up through NaCl saturation. They may physically affect the evaporation process and their by-products may chemically
modify or bind with dissolved ions. Many solar salt facilities engage microbiologists to establish monitoring programs for
analyses of nutrients, standing crop and associated biological variables in the ponds. Other solar salt companies engage microbiologists
only when there are “crises” in the ponds that interfere with salt production. Journal of Industrial Microbiology & Biotechnology (2002) 28, 42–47 DOI: 10.1038/sj/jim/7000173
Received 20 May 2001/ Accepted in revised form 13 June 2001 相似文献