Factors that Affect Pancreatic Islet Cell Autophagy in Adult Rats: Evaluation of a Calorie-Restricted Diet and a High-Fat Diet

Aging may be a risk factor for type 2 diabetes in the elderly. Dietary intervention can affect glucose tolerance in adults, which may be due to body composition and islet cell autophagy. The aim of this study was to determine the effects of various dietary interventions on islet cell autophagy. Pancreatic tissue and blood samples were collected from Sprague Dawley rats (14–16 months old, n = 15 for each group) that received a normal diet (ND), a high-fat diet (HFD), or a calorie-restricted diet (CRD). The body weight (BW), visceral fat, serum lipid levels, fasting serum glucose, insulin levels, and β/α cell area were determined in 14-16-(0-w), 16-18-(8-w), and 18-20(16-w)-month-old rats. Pancreatic islet autophagy (LC3B and LAMP2), AP (Acid Phosphatase) and apoptosis (apoptosis index, AI (TUNEL assay) and cleaved caspase-3) were detected using immunohistochemistry, ELISA and western blot. At 16 weeks, the expressions of LC3B, LAMP2 and AP markedly increased in both the HFD (P<0.01) and CRD (P<0.05) groups; however, an increase in the AI (P<0.05), cleaved caspase-3 and Beclin1 expression and a decrease in the expressions of BCL2 and BCLXL (P<0.05) were observed in only the HFD group. FFA, triglyceride levels, HOMA-IR, insulin levels and glucagon levels were significantly increased in the HFD group but decreased in the CRD group at 16 weeks (P<0.05). The degree of islet cell autophagy was potentially regulated by the levels of FFA and islet cell insulin and glucagon, which may have been due to the effects of Beclin1/BCL2.     

Nitric oxide generation by hemocytes of the mussel Mytilus galloprovincialis.

The phagocytic activity of Mytilus galloprovincialis hemocytes is thought to be associated with NADPH-oxidase activity of the plasma membrane, thus producing superoxide anions. Few studies, however, have been devoted to nitric oxide release by these haemocytes. We investigated NO generation in M. galloprovincialis in order to understand its role in the defensive mechanisms of these organisms. The presence of NO-synthase-like enzymatic activity in protein homogenates from M. galloprovincialis hemocytes was revealed by the conversion of radiolabelled L-arginine to L-citrulline. We observed partial inhibition of the luminol-dependent chemiluminescence of stimulated M. galloprovincialis hemocytes by both NO-synthase inhibitors and superoxide dismutase, indicating that peroxynitrite (which results from the reaction between nitric oxide and superoxide anions) partially mediated this chemiluminescence. Furthermore, we confirmed the production of nitric oxide by M. galloprovincialis by highlighting the nitric oxide-synthase-dependence of the nitrate and nitrite production of stimulated hemocytes.     

抗人肺腺癌单克隆抗体重,轻链可变区基因的分离克隆和序列测定

根据鼠免疫球蛋白重。轻链可变区基因ＦＲ１和ＦＲ４的序列保守性,化学合成了适于体外扩增Ｉｇ重、轻链可变区基因（Ｖ_Ｈ和Ｖ_Ｌ）的数对引物。以分泌抗人肺腺癌单抗的杂交瘤细胞株ＷＬＡ－２Ｃ４的基因组ＤＮＡ为模板,ＰＣＲ扩增Ｖ_Ｈ和Ｖ_Ｌ基因,分别克隆人ｐＵＣ１９载体。转化子经蓝、白斑筛选,酶切鉴定,双脱氧测序证实确为鼠单抗可变区基因,其中Ｖ_Ｈ基因全长为３４８ｂｐ,编码１１６ａａ,属重链ⅡＢ亚类;Ｖ_Ｌ基因全长３１８ｂｐ,编码１０６ａａ,属Ｋ轻链Ⅵ亚类。     

鼠肝DNA甲基化酶的纯化及物理化学性质的研究

以Ｗｉｓｔａｒ大鼠肝为材料,确立了一个简便的纯化鼠肝ＤＮＡ甲基化酶的程序,包括：细胞的超声破碎、去内源核酸、硫酸铵盐析、磷酸纤维素亲和层析、ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－５０柱层析及ＳｅｐｈａｄｅｘＧ－１５０凝胶过滤。用不同浓度聚丙烯酰胺凝胶电泳和孔梯度凝胶电泳检测,纯化后的酶已达电泳均一,且酶的比活力提高１１２倍。以聚丙烯酰胺孔梯度凝胶电泳测得其天然酶的分子量为３６５ｋＤ,以ＳＤＳ－聚丙烯酰胺凝胶电泳测得该酶有两种亚基,大亚基为９５ｋＤ,小亚基为８５ｋＤ,推测该酶由两个大亚基和两个小亚基组成。     

利用马尾松年轮资料重建江苏暖湿地区气候的初步研究

利用树木年轮气候学方法,根据马尾松生长对气候变量具非线性响应,尝试重建江苏暖湿地区过去１１６年（１８７４～１９９０）的年平均气温和降水量。温度的重建效果优于降水量,实测值与重建值两者的缩减误差（ＲＥ）分别为０．１２和０．１０,两者的平均偏差百分率分别为２．３％和２０％。绝大部分重建结果可从观测记录和历史文献中得到验证,但在温度较高或降水量较多的若干年份,实测值与重建值有较大偏差。     

西安市MRSA 耐消毒剂基因qacA/B 的检测

目的:了解西安市三甲综合医院耐甲氧西林金黄色葡萄球菌(MRSA)qacA/B基因的携带情况,以便掌握其对消毒剂的耐药情况。方法:收集临床分离的152株耐甲氧西林金黄色葡萄球菌,采用聚合酶链反应检测qacA/B基因,并将qacA/B基因扩增产物进行测序,测序结果进行比对。结果:152株耐甲氧西林金黄色葡萄球菌中有11株检出qacA/B阳性,qacA/B携带率7.2%;测序结果比对发现,4株qacA的基因编码序列同一位点均有一个碱基发生突变(C→T),苏氨酸突变为异亮氨酸。结论:该地区临床分离的耐甲氧西林金黄色葡萄球菌中qacA/B携带率相对较低,但也存在抵抗消毒剂的风险,临床应加强消毒剂使用的管理,阻止MRSA的传播,减少感染的发生。     

植物甜蛋白马宾灵(Mabinlin Ⅱ)的二级结构及其B细胞抗原表位预测

马宾灵(MabinlinⅡ)是中国所特有的植物甜蛋白,在目前已知的7种植物甜蛋白中具有最佳的热稳定性,将其作为新型甜味剂有着广阔的市场前景。本研究以马宾灵的氨基酸序列为基础,采用Garnier-Robson方法和Chou-Fasman方法预测马宾灵的二级结构,采用Karplus-Schulz方法预测马宾灵的蛋白质骨架区柔韧性,采用Kyte-Doolittle方法预测马宾灵的蛋白质疏水性,采用Emini方法预测马宾灵的蛋白质表面可能性,采用Jameson-Wolf方法预测马宾灵的B细胞抗原表位。分析结果表明,马宾灵的A链多形成转角和无规则卷曲结构,A链的N端27～30区段形成较柔软的蛋白质骨架结构,A链的N端4～6、7～9、10～11、12～14、20～22、23～26和30～33区段为抗原位点的可能性较大;马宾灵的B链多形成β折叠和转角结构,B链的N端0～7、9～13、28～29、33～34、40～45、53～54和55～57区段为抗原位点的可能性较大。本研究以生物信息学手段分析预测马宾灵的二级结构及其B细胞抗原表位,为设计马宾灵多克隆抗体以检测马宾灵在不同生物反应器中的表达研究提供参考数据。     

Distribution of Cryptosporidium parvum sporozoite apical organelles during attachment to and internalization by cultured biliary epithelial cells

Although accumulating evidence supports an active role for host cells during Cryptosporidium parvum invasion of epithelia, our knowledge of the underlying parasite-specific processes triggering such events is limited. In an effort to better understand the invasion strategy of C. parvum, we characterized the presence and distribution of the apical organelles (micronemes, dense granules, and rhoptry) through the stages of attachment to, and internalization by, human biliary epithelia, using serial-section electron microscopy. Novel findings include an apparent organized rearrangement of micronemes upon host cell attachment. The apically segregated micronemes were apposed to a central microtubule-like filamentous structure, and the more distal micronemes localized to the periphery and apical region of the parasite during internalization, coinciding with the formation of the anterior vacuole. The morphological observations presented here extend our understanding of parasite-specific processes that occur during attachment to, and internalization by, host epithelial cells.     

基因组编辑脱靶研究进展

近年各种基因组编辑技术的成功研发为人类疾病的治疗与预防谱写了新的篇章,这些技术对应的基因组编辑工具主要包括锌指核酸酶(ZFNs)、转录激活子样效应因子核酸酶(TALENs)和最近发现的规律成簇间隔短回文重复(CRISPR)/Cas系统。这些工具相应的脱靶问题目前是制约基因组编辑技术介导人类疾病治疗的重要瓶颈。本文将分别从基因组编辑工具的介绍、脱靶的现状、解决优化的方案和检测方法进行总结与探讨,通过比较,进一步了解基因组编辑工具的优缺点及相关脱靶检测方法的适用性。