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Latent inhibition (LI) is a reduction in the rate of acquisition of a Pavlovian conditioned response that results from prior nonreinforced preexposure to a conditioned stimulus (CS). LI has been suggested to reflect the operation of mechanisms involved in stimulus selection for subsequent cognitive processing. The present experiment was conducted to assess the effect of bilateral lesions of the nucleus basalis magnocellularis (NBM) on LI employing a conditioned emotional response paradigm. Bilateral lesions of the NBM were produced by administration of 0.12 M quisqualic acid and resulted in decreased cortical acetylcholinesterase staining, as well as a 40% reduction in cortical choline acetyltransferase activity. Following lever press training, preexposed animals received 40 presentations of a 60-s tone CS. Nonpreexposed animals received no tone presentations. Acquisition of conditioned suppression was then assessed over the course of 4 tone-shock (0.6 mA, 0.5 s) pairings. Control, preexposed animals displayed a retarded rate of acquisition in comparison to nonpreexposed controls, thereby demonstrating that the parameters used in the present experiment produced LI. In contrast, lesioned animals preexposed to the CS acquired conditioned suppression as readily as non-preexposed lesioned animals. However, the acquisition of conditioned suppression in both lesioned groups was found to be similar to that displayed in the preexposed control group. This pattern of results was interpreted as being attributable to a lesion-induced impairment in the ability to maintain stimulus processing, rather than a deficit in the ability to filter a stimulus. Copyright © 1996 Elsevier Science Inc.  相似文献   
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Five patients with hereditary angioedema (HAE) were studied during attacks and remission as were healthy controls. The high levels of C1/C1-INH complexes, low C4 and high ratio C4 activation products (C4bc)/C4 also differed significantly during remission compared to controls.During attacks C4bc/C4 increased (922–2007; P =0.022, remission versus attacks, median values throughout), C2 and CH50 dropped (111–31%; P =0.043 and 110–36%; P =0.016, respectively), TCC (C5b-9) increased (0.88–1.23 AU/ml; P =0.028). Cleavage of HK increased to be almost complete during attacks (20–90%; P =0.009). While factor XIa/serpin-complexes did not increase, a more than twofold rise in thrombin/antithrombin-complexes (0.20–0.50 μg/l; P =0.009) and in plasmin/alpha-2-antiplasmin-complexes (7.3–17 nmol/l; P =0.028) was observed. For the first time cascade activation in HAE was studied simultaneously, and corroborates that attacks lead to activation of the kallikrein-kinin system, fibrinolysis and early part of the classical complement pathway. In addition, the authors present novel data of terminal complement and coagulation activation, the latter apparently not via FXIa.  相似文献   
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河南省1963~2002年百日咳流行动态及控制策略分析   总被引:8,自引:0,他引:8  
目的掌握河南省40年来百日咳的流行病学特征及其影响因素,为制定免疫策略和预测疫情趋势提供依据。方法对河南省不同免疫阶段的百日咳流行病学特征进行分析。结果河南省40年来共报告百日咳3 065 075例,死亡572例。大致可分4个阶段:1963~1978年,年平均发病率为293.47/10万,死亡43例;1979~1983年,年发病率为87.70/10万~17.78/10万,呈逐年下降趋势,死亡6例;1984~1990年,发病率为1.28/10万~6.73/10万,死亡1例;1990年以后发病率为0.25/10万~1.00/10万,连续10年无死亡病例。表明随着百日咳疫苗接种率的不断提高,不但大大降低了百日咳的发病率和死亡率,也改变了其流行周期。结论目前的免疫策略首先应继续做好儿童常规免疫,其次应加强百日咳疫情管理,提高疫情报告的及时性、准确性。  相似文献   
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Cerebrospinal fluid (CSF) amino acid levels including excitatory amino acids (i.e. glutamate and aspartate) in 25 preterm and 18 full-term newborn infants with no serious disease except intracranial hemorrhage (ICH) were measured. ICH was detected in 13 preterm and six full-term infants on the basis of the clinical, lumbar puncture (LP) and cranial ultrasonography (CraUSG) findings. Twelve preterm and 12 full-term infants who were neurologically healthy comprised the control group. The mean concentration of CSF amino acids did not differ between preterm and full-term infants. The CSF concentrations of taurine, threonine, glycine, alanine, valine, isoleucine, leucine, tyrosine and phenylalanine in preterm infants, and threonine, aspartic acid and alanine in full-term infants were significantly elevated in infants with ICH. These abnormalities, especially in preterm infants, are probably related to cerebral hypoxia in CSF amino acid concentrations in newborn infants with ICH.  相似文献   
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目的:进一步探讨LCP在胫骨骨折微创技术中的治疗经验。方法:自2003年8月~2005年8月,选取胫骨骨折患者50例,随机分为观察组(LCP组)及对照组(LC-DCP组)进行内固定对照研究和随访。所得数据进行统计分析。结果:所有病例无感染、内固定松动、不愈合等情况出现。观察组手术时间和扶拐下地的时间有明显缩短,统计学有显著性差异。观察组临床愈合时间比对照组也有提前,但无显著的统计学差异。结论:LCP系统设计合理,固定牢靠,操作效率高,能最大程度保护局部软组织和血运,促进骨折愈合。各方面性能指标优于LC-DCP系统,是应用MIPPO技术治疗胫骨骨折良好的内固定选择。  相似文献   
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目的:了解曲唑酮治疗酒精滥用的有效性并与呋喃唑酮进行比较。方法:采用随机对照的方法,用汉密尔顿抑郁量表(HAMD)、汉密尔顿焦虑量表(HAMA)和饮酒心理依赖评分表等,分别评定两组患者在处理前后的分值,然后作前后比较及组间比较。结果:两组患者治疗后比治疗前HAMD、HAMA及饮酒心理依赖评分均有显著差异(P<0.05或P<0.01),但两组间比较差异均无显著性。结论:曲唑酮对于戒除酒瘾有明显疗效,不失为一种新的选择。  相似文献   
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