GABAB receptor protein and mRNA distribution in rat spinal cord and dorsal root ganglia

The presence of metabotropic receptors for GABA, GABAB, on primary afferent terminals in mammalian spinal cord has been previously reported. In this study we provide further evidence to support this in the rat and show that the GABAB receptor subunits GABAB1 and GABAB2 mRNA and the corresponding subunit proteins are present in the spinal cord and dorsal root ganglion. We also show that the predominant GABAB1 receptor subunit mRNA present in the afferent fibre cell body appears to be the 1a form. In frozen sections of lumbar spinal cord and dorsal root ganglia (DRG) GABAB receptors were labelled with [3H]CGP 62349 or the sections postfixed with paraformaldehyde and subjected to in situ hybridization using oligonucleotides designed to selectively hybridize with the mRNA for GABAB(1a), GABAB(1b) or GABAB2. For immunocytochemistry (ICC), sections were obtained from rats anaesthetized and perfused-fixed with paraformaldehyde. The distribution of binding sites for [3H]CGP 62349 mirrored that previously observed with [3H]GABA at GABAB sites. The density of binding sites was high in the dorsal horn but much lower in the ventral regions. By contrast, the density of mRNA (pan) was more evenly distributed across the laminae of the spinal cord. The density of mRNA detected with the pan probe was high in the DRG and distributed over the neuron cell bodies. This would accord with GABAB receptor protein being formed in the sensory neurons and transported to the primary afferent terminals. Of the GABAB1 mRNA in the DRG, approximately 90% was of the GABAB(1a) form and approximately 10% in the GABAB(1b) form. This would suggest that GABAB(1a) mRNA may be responsible for encoding presynaptic GABAB receptors on primary afferent terminals in a manner similar to that we have previously observed in the cerebellar cortex. GABAB2 mRNA was also evenly distributed across the spinal cord laminae at densities equivalent to those of GABAB1 in the dorsal horn. GABAB2 mRNA was also detected to the same degree within the DRG. Immunocytochemical analysis revealed that GABAB(1a), GABAB(1b) and GABAB2 were all present in the spinal cord. GABAB(1a) labelling appeared to be more dense than GABAB(1b) and within the superficial dorsal horn GABAB(1a) was present in the neuropil whereas GABAB(1b) was associated with cell bodies in this region. Both 1a and 1b immunoreactivity was expressed in motor neurons in lamina IX. GABAB2 immunoreactivity was expressed throughout the spinal cord and was evident within the neuropil of the superficial laminae.     

自制中药粉剂中盐酸小檗碱的定量检测方法

目的测定自制中药粉剂中盐酸小檗碱的含量。方法采用薄层扫描法测定了盐酸小檗碱的含量。结果盐酸小檗碱在1～6μg间呈良好的线性关系,r=0.9975,平均回收率为97.95%,RSD为2.36%(n=5)。结论所建立的方法可靠准确地进行定量检测,可用于该制剂的质量控制。     

Comparison of Radiographic and pQCT Analyses of Healing Rat Tibial Fractures

Fracture healing and callus formation have traditionally been evaluated by using X-ray radiography. Here we compared X-ray radiography and peripheral quantitative computed tomography (pQCT) in evaluating the healing callus of standardized tibial fractures in 141 female rats after a 4- or 8-week follow-up. The results were compared with the tensile (4-week) and compressive (8-week) failure load of the callus. The projectional size of callus, as defined from lateral ex vivo radiographs, correlated significantly with the pQCT-defined cross-sectional area (CSA) of mid-callus. This relationship was dependent on the pQCT attenuation threshold, being higher for the CSA of compact bone (r = 0.85, P < 0.0001) than for the total bone CSA (r = 0.68, P < 0.0001). Radiographically defined callus projectional area also correlated strongly with bone mineral content (BMC) (r = 0.84–0.86, P < 0.0001). The mean optical density of the callus analyzed from the radiographs had only a weak correlation with the pQCT-defined bone mineral density (BMD) of callus. A weak negative relationship was found between CSA and BMD. The optical density analyzed from lateral radiographs did not correlate with the tensile or compressive failure load of callus. Callus size, BMC, and BMD were associated with the compressive failure load, whereas both radiographs and pQCT were poor in explaining the failure load in tension. Received: 28 June 1999 / Accepted: 28 October 1999     

定量酶联免疫吸附试验在检测麻疹IgG抗体中的应用与比较

目的对定量酶联免疫吸附试验(ELISA)在麻疹病毒IgG抗体检测中的应用进行评价,并与传统的半定量ELISA方法做比较。方法收集2003年的92份山西省和内蒙古自治区健康成人血清,用德国维润公司定量ELISA试剂盒测定麻疹IgG抗体滴度。这些血清已经用半定量方法将抗体滴度分为阴性和1∶200、1∶800、1∶3200、1∶12800四个组。将两种方法测定的结果进行比较。结果定性测定结果分析发现,92份血清标本中,5份阴性,1份可疑,86份阳性,与传统半定量ELISA方法的一致率为96·74%,统计分析两实验结果差异无显著的统计学意义。定量测定结果分析发现,随着抗体滴度的增高,该组血清抗体国际单位(IU)也随之上升,均数也随之增高,抗体滴度分组与抗体IU呈明显的正相关,相关系数(rs)为0·963,P<0·000。可重复性检验证明该试剂的可重复性较好。结论定量ELISA方法在麻疹以及其它病毒血清学研究中的应用具有优势。     

L’appréciation des risques sanitaires liés aux aliments : une vision de biométriciens: Seconde partie : mises en œuvre

National and international authorities recommend the use of quantitative risk assessment for any decision-making in the field of the sanitary and nutritional food safety. This paper deals with the principles for the implementation of such analyses. The construction of the model and data specification from food contamination to adverse effects is presented and discussed. While point estimation is the rule for a fast decision-making, the stochastic approach appears to be the only one that allows to answer to the questions of the decision maker. For this approach, Monte-Carlo simulation vs the bayesian approach are compared, the latter is favoured. Nutritionists should be aware of the particular interest to use these methods for the evaluation of the impact of a volontary incorporation of nutriment in food.     

连续消毒中大肠杆菌O_(157)∶H_7对碘伏抵抗力的变化及其与质粒pO_(157)关系的研究

〔目的〕研究分析在连续消毒中大肠杆菌O1 57∶H7对碘伏抵抗力变化及其与质粒pO1 57关系。〔方法〕用碘伏连续消毒 6株大肠杆菌O1 57∶H710代 ,对比消毒前后试验菌对该消毒剂的抵抗力、质粒图谱以及质粒酶切图谱 ,用SDS -高温法消除原始菌与连续消毒后试验菌的质粒。〔结果〕连续消毒 10代后 ,试验菌对碘伏的抵抗力增加 ;试验菌的质粒图谱以及质粒pO1 57的CalⅠ酶切图谱均无明显变化 ;消除原始菌的小质粒后 ,细菌对消毒剂的抵抗力不变 ,消除原始菌的大质粒和连续消毒后试验菌的质粒后 ,试验菌对碘伏的抵抗力增加。〔结论〕结果提示 ,连续消毒会使试验菌对碘伏的抵抗力增加 ,抵抗力增加的原因可能与质粒pO1 57无直接关系。     

连续消毒中大肠埃希菌O_(157)∶H_7对洗必泰抵抗力的变化和与质粒pO_(157)的关系

目的　研究连续消毒中大肠埃希菌O157∶H7对洗必泰抵抗力的变化及其与质粒 pO157关系。方法　用洗必泰连续消毒 6株大肠埃希菌O157∶H710代 ,消除连续消毒前后试验菌的质粒 ;对比消毒前后试验菌对该消毒剂的抵抗力、质粒图谱以及质粒酶切谱。结果　连续消毒 10代后 ,试验菌对洗必泰的抵抗力不变 ;试验菌的质粒图谱以及质粒pO157的ClaⅠ酶切图谱均无明显变化 ;消除连续消毒前后试验菌的质粒后 ,试验菌对洗必泰的抵抗力不变。结论　连续消毒不会使试验菌对洗必泰的抵抗力增加 ,且试验菌对洗必泰的抵抗力与质粒 pO157无直接关系。     

脑缺血再灌注大鼠海马神经元线粒体变化的形态计量分析

目的:探讨大鼠脑缺血再灌注后海马神经元线粒体的形态变化.方法:采用结扎颈总动脉的方法制备缺血再灌注模型,根据再灌注时间将大鼠分为Ⅰ、Ⅱ、Ⅲ三组.电镜下观察海马神经元线粒体的改变,并采用Leica Qwin图像分析系统对线粒体的形态变化进行计量分析.结果:缺血再灌注各组海马神经元线粒体均出现损伤,线粒体肿胀、外膜破坏,嵴断裂、溶解呈空泡状,缺血再灌注Ⅱ组线粒体的损伤较Ⅰ、Ⅲ组严重.与假手术组相比,缺血再灌注Ⅱ、Ⅲ组线粒体的体密度、数密度、比表面和嵴膜表面密度明显减小(P<0.05),平均体积和平均截面积显著增大(P<0.05);缺血再灌注Ⅰ组仅平均体积和平均截面积增大(P<0.05),其余改变不明显(P＞0.05).结论:缺血再灌注可损伤海马神经元线粒体的形态结构,且与再灌注时程有关.     

磺酰胺嘧啶类化合物的定量构效关系研究

目的研究磺酰胺嘧啶类化合物的定量构效关系(QSAR)。方法应用量子化学方法计算了48个磺酰胺嘧啶类化合物的结构参数,并用神经网络方法讨论了此类化合物分子结构与内皮素(ETs)受体拮抗活性之间的QSAR。结果获得了一个预测能力较好的QSAR神经网络模型。结论磺酰胺嘧啶类化合物与ETs受体之间存在直接的电荷迁移作用,前线轨道能、电子结构、空间因素是影响此类化合物对ETs活性的主要因素。将量子化学和神经网络相结合的方法可以成为QSAR研究的有效工具。     

栀子药材中三种有效成分HPLC定量分析结果不确定度的评定

采用HPLC方法同时测定栀子药材中栀子苷、绿原酸和藏红花素Ⅰ的含量,通过对测试方法流程进行分析,确定不确定度来源,结合含量测定方法验证数据,计算了不确定度分量、合成不确定度及扩展不确定度;结果表明,用HPLC方法定量分析栀子药材中栀子苷、绿原酸和藏红花素1的方法满足现代药物分析方法学的要求,且三者的扩展不确定度分别为0.1024,0.2254,0.1265.