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31.
Nicotine has been found to improve memory performance in a variety of tests including the radial-arm maze. Nicotine may have effects mediated by promoting the release of dopamine. The present study was conducted to determine the interactions of nicotine with D1 and D2 agonists. Rats were acutely administered nicotine, the D1 agonist SKF 38393, and D2/D3 agonist quinpirole, and nicotine together with each of these agonists. Nicotine significantly improved choice accuracy in the radial-arm maze. The D1 agonist SKF 38393 significantly impaired choice accuracy. Nicotine was effective in reversing this effect. The D2/D3 agonist quinpirole showed a trend toward potentiating the improvement in choice accuracy caused by 0.2 mg/kg (0.43 μmol/kg) of nicotine. These data show that, as with the nicotinic antagonist mecamylamine, there are significant interactions of dopamine systems with nicotine effects. © 1994 Wiley-Liss, Inc. 相似文献
32.
Anxiolytic benzodiazepines have been shown to impair place learning in the Morris water maze. However, a clear-cut demonstration of a direct and specific effect on mnemonic processes has not yet been offered. In the present study, the effects of diazepam on place navigation in the Morris water maze were studied in rats. Three conditions were examined: learning, reversal learning and learning after familiarisation of animals with the maze. In view of the anxiolytic and sedative properties of diazepam, appropriate doses of the drug, i.e. those that produced an anxiolytic effect but no major motor impairment, were initially selected in the water-lick conflict and rotarod tests, respectively. Doses of 2.5 and 5 mg/kg PO increased punished drinking in the water-lick conflict test without significantly decreasing rotarod performance. These doses were then used to assess the effects of diazepam on spatial behaviour. Diazepam, at both doses, impaired place learning in behaviourally naive rats. Such an effect appeared to be transient: diazepam-treated rats eventually reached control performance. Moreover, analysis of the probe trial at the end of training revealed adoption of a spatial strategy to locate the submerged platform. Neither reversal learning nor learning after familiarisation was affected. These results do not replicate previous findings in the Morris water maze and provide some evidence that the diazepam-induced place learning deficit may be primarily anxiolytic in nature. 相似文献
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宝鸡市城市饮用水与人群健康效应的调查研究 总被引:1,自引:1,他引:0
本文通过对宝鸡市居民饮自来水和自备井水的人群进行了回顾性和前瞻性调查分析,结果发现,饮自来水与饮未经处理自备井水明显的差异。即调查组(饮自来水)肠道传染病发病率为4.22%和6.82%,对照组(饮自备井水)发病率为7.71%和11.56%经卡方检验P<0.05,差异有显著性。从发病病种来看,调查组和对照组均以腹泻为主,其次为痢疾和肝炎,发病率分别是:腹泻,调查组为35.59‰和63.00‰,对照组 相似文献
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TAMÁS HENICS & DENYS N. WHEATLEY 《International journal of experimental pathology》1997,78(5):343-354
Hep-2, human epithelial carcinoma cells, and human foreskin fibroblasts (FF9 and FF13) were exposed to either an ultrafiltrate (< 50 kD) of human sera or the weak base, procaine hydrochloride, to induce reversible cytoplasmic vacuolization. The formation of vacuoles was shown not to be due to imbibition of medium. Ultrastructural details obtained from various stages of vacuole formation were compared. In both cases of induction vacuoles were irregular and often appeared membraneless, with little in the way of electron-dense content. They started to form in the perinuclear cytoplasm and progressed towards the periphery. Osmotic stress was not involved since mitochondria remained normal throughout a vacuolization episode.
Vacuoles were often seen in close contact with filamentous structures, and this association remained detectable at late stages of the phenomenon. Fluorescent visualization of F-actin confirmed that the vacuoles were frequently bordered by microfilaments. No major metabolic impairment was apparent in vacuolized cells as judged by protein synthesis measurements, but nuclear fluorescence (DNA content) and forward light scatter (nuclear volume) by flow cytometric analysis suggested late S phase and G2 retardation.1 H-nmr relaxation measurements indicated intracellular water restricted in motional characteristics in vacuolized cells. The possibility of a restricted cytoplasmic phase separation as part of a transient adaptation response is raised, and a hypothesis to explain the findings is discussed. 相似文献
Vacuoles were often seen in close contact with filamentous structures, and this association remained detectable at late stages of the phenomenon. Fluorescent visualization of F-actin confirmed that the vacuoles were frequently bordered by microfilaments. No major metabolic impairment was apparent in vacuolized cells as judged by protein synthesis measurements, but nuclear fluorescence (DNA content) and forward light scatter (nuclear volume) by flow cytometric analysis suggested late S phase and G2 retardation.
37.
介绍了一种从谷朊粉废水中提取戊聚糖的工艺,由此工艺得到的产品(戊聚糖质量分数约70%,蛋白质质量分数约20%)能较好地保持戊聚糖的特性.研究了其它添加剂(卡拉胶)对戊聚糖的乳化性,戊聚糖对肉制品持油、持水性以及其质构的影响.谷朊粉废弃水提取物与卡拉胶的复配产品在添加量(质量分数)为6%时能使肉制品有较好的持油性和相应的质构. 相似文献
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39.
夜来香根茎水提取液局部麻醉作用的研究 总被引:13,自引:4,他引:9
目的:研究夜来香(CN)根茎水提取液的局部麻醉作用及其作用机制。方法:采用蟾蜍离体坐骨神经动作电位法、豚鼠皮丘法、椎管麻醉法、表面麻醉法。结果:20%的CN水提取液对蟾蜍离体坐骨神经动作电位可完全消失,但较1%的普鲁卡因稍弱。豚鼠皮丘实验表明,20%CN提取液有浸润麻醉作用,其浸润麻醉效果与1%的普鲁卡因相似,而且盐酸肾上腺素可增强其麻醉强度和明显延长局麻作用时间;家兔椎管麻醉实验表明CN提取液有明显的椎管麻醉作用;CN提取液对家兔角膜也有一定的表麻作用,只是作用强度及持续时间比1%的普鲁卡因稍弱或稍短。结论:CN提取液有明显的局部麻醉作用。 相似文献
40.
微乳对难溶性药物增溶机理的研究 总被引:17,自引:1,他引:16
目的:初步探讨微乳对难溶性药物的增溶机理.方法:经处方筛选及相图研究确定(BL-9/正丁醇3∶1)/油/水比例为9∶1∶40的微乳处方;以二氢吡啶类药物为模型药物,测定其在微乳、胶束和油相中的溶解度及油/水分配系数;根据化学结构,采用计算机软件计算药物的特性参数,并结合模型药物的特性分析微乳增溶难溶性药物的机理.结果:微乳对药物的增溶效果远大于油相和胶束,并随药物的脂溶性和空间结构的改变而变化.结论:微乳可用于增溶难溶性药物,且脂溶性越大,空间位阻越小,增溶效果越明显. 相似文献