Purification and some properties of the methyl-CoM reductase of Methanothrix soehngenii

Abstract The methyl-CoM reductase from Methanothrix soehngenii was purified 18-fold to apparent homogeneity with 50% recovery in three steps. The native molecular mass of the enzyme estimated by gel-fitration was 280 kDa. SDS-polyacrylamide gel electrophoresis revealed three protein bands corresponding to M _r 63 900, 41 700 and 30 400 Da. The methyl-coenzyme M reductase constitutes up to 10% of the soluble cell protein. The enzyme has K _m apparent values of 23 μM and 2 mM for N -7-mercaptoheptanoylthreonine phosphate (HS- HTP = component B ) and methyl-coenzyme M (CH₃CoM) respectively. At the optimum pH of 7.0 60 nmol of methane were formed per min per mg protein.     

百色市1～6岁儿童乙肝疫苗接种后免疫水平状况分析

掌握百色市乙型肝炎疫苗纳入儿童免疫规划后的免疫效果,客观评价免疫规划工作现状。方法按现况研究原理,全市12个县(区),每个县(区)各抽取150名儿童,每个县在东、西、南、北、中五个方位随机抽取5个行政村,每个行政村抽取6个年龄组(1～6岁儿童),每个年龄组抽取5名常住儿童(当地居住三个月以上),收集血清样本进行乙肝病毒感染相关标志表面抗原及抗体检测。结果全市共调查1～6岁儿童1 809名儿童,乙肝表面抗原携带率为0.66%,低于2006年全国调查的1～4岁人群乙肝表面抗原携带率(0.96%),达到中国《2006—2010年全国乙型病毒性肝炎防治规划》提出的5岁以下儿童乙肝表面抗原携带率<1%的控制目标要求;1～6岁儿童乙肝表面抗体阳性率为77.77%,高于2006年全国调查的1～4岁人群乙肝抗体阳性率(71.24%)。结论百色市自2003年将乙肝疫苗纳入免疫规划管理后,乙肝免疫效果显著,乙肝病毒表面抗原阳性率大幅度下降,婴幼儿体内保护性抗体水平也高于全国水平。加强对孕产妇住院分娩率和婴幼儿乙肝疫苗接种工作,尤其是乙肝疫苗首针及时接种是今后乙肝预防控制的重点。     

Isolation and Identification of the Female Sex Pheromone of the Potato Tuberworm Moth,Phthorimaea operculella (Zeller)

The sex pheromone produced by adult females of the potato tuberworm moth was isolated from unmated female moths reared in the laboratory. The gas Chromatographic and mass spectrometric data suggested the pheromone to be a tridecatrienyl acetate. The isolated pheromone was subjected to partial hydrogenation with hydrazine and hydrogen peroxide and subsequent ozonolysis to produce a mixture of ω-acetoxy-alkanals. They were identified by mass Chromatographic technique as 4-acetoxy-butanal, 7-acetoxy-heptanal, and 10-acetoxy-decanal respectively. Consequently, the pheromone was identified as 4,7,10-tridecatrienyl acetate except the geometric configuration.     

Optimal control strategies and cost-effectiveness analysis of a malaria model

The aim of this paper is to investigate the effectiveness and cost-effectiveness of three malaria preventive measures (use of treated bednets, spray of insecticides and a possible treatment of infective humans that blocks transmission to mosquitoes). For this, we consider a mathematical model for the transmission dynamics of the disease that includes these measures. We first consider the constant control parameters’ case, we calculate the basic reproduction number and investigate the existence and stability of equilibria; the model is found to exhibit backward bifurcation. We then assess the relative impact of each of the constant control parameters measures by calculating the sensitivity index of the basic reproductive number to the model's parameters. In the time-dependent constant control case, we use Pontryagin's Maximum Principle to derive necessary conditions for the optimal control of the disease. We also calculate the Infection Averted Ratio (IAR) and the Incremental Cost-Effectiveness Ratio (ICER) to investigate the cost-effectiveness of all possible combinations of the three control measures. One of our findings is that the most cost-effective strategy for malaria control, is the combination of the spray of insecticides and treatment of infective individuals. This strategy requires a 100% effort in both treatment (for 20 days) and spray of insecticides (for 57 days). In practice, this will be extremely difficult, if not impossible to achieve. The second most cost-effective strategy which consists of a 100% use of treated bednets and 87% treatment of infective individuals for 42 and 100 days, respectively, is sustainable and therefore preferable.     

研究报告：缓激肽上调豚鼠肠道黏膜下神经丛环氧合酶2的表达

目的缓激肽和缓激肽B2受体在肠神经系统中起重要作用。缓激肽通常参与肠道的炎症反应和神经保护,这种作用取决于缓激肽诱导前列腺素的形成。环氧合酶1 (COX1)和环氧合酶2 (COX2)催化花生四烯酸转化为前列腺素。本研究旨在探讨缓激肽刺激对豚鼠肠神经前列腺素E2 (p GE2)释放和COX2表达的影响及信号机制。方法本文通过免疫荧光检测肠神经细胞中COX2与神经细胞标志物Anti-Hu和ch AT的表达;采用PCR及蛋白质印迹(Western blot)检测不同条件下缓激肽刺激对COX2表达的影响;使用缓激肽B1受体的选择性拮抗剂Leu-8和B2受体的选择性拮抗剂HOE-140,研究缓激肽影响COX2表达的信号机制;利用COX2选择性拮抗剂NS398和COX1拮抗剂FR12207,观察COX2在缓激肽诱导p EG2释放的作用。结果 COX2与神经细胞标志物Anti-Hu和ch AT在肠神经细胞上共同表达,缓激肽可通过B2受体诱导肠神经细胞COX2的表达。缓激肽刺激引起的肠神经细胞p GE2的释放与COX2表达升高密切相关。结论缓激肽通过B2R影响肠道黏膜下神经丛COX2的表达,肠道缓激肽...     

Curcumin inhibits ultraviolet light induced human immunodeficiency virus gene expression

Recently, we reported that the herbal drug St. John's Wort is a potent inhibitor of UV-induced HIV-LTR activation in stably transfected HIVcat/HeLa cells [35]. Our previous studies have demonstrated that the activation of p38 MAP kinase (stress-activated protein kinase-2) and NF-B are both required for a full UV-induced HIV gene expression response. In this study we have investigated the mechanism by which curcumin inhibits UV-activated HIV-LTR gene expression. We found that treatment of HIVcat/HeLa cells with micromolar concentrations of curcumin completely abolished UV activation of HIV gene expression. Curcumin treatment at similar doses as those used to inhibit HIV gene expression also effectively blocked UV activation of NF-B, as demonstrated by electrophoretic mobility shift assay. In contrast, curcumin did not inhibit UV-induced phosphorylation of p38 MAP kinase. This observation was also supported by findings that curcumin did not inhibit UV-induced phosphorylation of CREB/ATF-1 and ATF-2. Although curcumin was ineffective in preventing UV-induced p44/42 MAP kinase phosphorylation, the JNK (1 and 2) and AP-1 activation were efficiently blocked by curcumin in HeLa cells. We conclude that the mechanism by which curcumin modulates UV activation of HIV-LTR gene expression mainly involves the inhibition of NF-B activation.     

B27K—去B链C端三肽胰岛素的制备、生物活力与自聚合性质

液相合成五肽Gly Phe Phe Tyr Lys(Boc)Obut,与B链C端去八肽胰岛素酶促缩合得到B2 7K 去B链C端三肽胰岛素(B2 7K DTrI,B2 7K destripeptideinsulin)。用小鼠惊厥法和小鼠降血糖法测得B2 7K DTrI的整体生物活力为标准胰岛素的 80 % ,B2 7K DTrI与人胎盘细胞膜胰岛素受体结合能力为标准胰岛素的 ( 12 5± 13 ) %。用凝胶过滤法证明B2 7K DTrI自聚合性质降低 ,具有与去B链C端五肽胰岛素相同的单体性质。在B2 7K DtrI结构中 ,B2 7T被K取代 ,其优点是在酵母中表达其前体后 ,可以很方便地通过胰蛋白酶水解获得     

肠道菌群失衡对乙型肝炎相关慢加急性肝衰竭患者血浆降钙素原升高的影响

目的 探讨肠道菌群失衡对乙型肝炎相关慢加急性肝衰竭（hepatitis B virus-related acute-on-chronic liver failure,HBV-ACLF）患者血浆降钙素原（procalcitonin,PCT）水平升高的影响。方法 检测29例HBV-ACLF（肝衰组）、14例慢性乙型肝炎（乙肝组）患者入院时的血浆PCT、内毒素（endotoxin,LPS）水平,收集患者新鲜尾便并通过高通量测序检测肠道菌群状况,统计分析两组患者间肠道菌群、B/E值、PCT和LPS水平的差异,以及肝衰组患者PCT、LPS、B/E值三者间的相关性。结果 与乙肝组患者比较,肝衰组厚壁菌门、放线菌门、双歧杆菌属、乳杆菌属等肠道菌群显著减少,而拟杆菌门、变形菌门、埃希菌属等肠道菌群过度生长,两组患者间各菌群比较差异均具有统计学意义（t=-4.84,Z=-2.84,Z=-2.57,Z=-4.39,t=3.59,t=2.64,t=2.19,P＜0.01、＜0.01、=0.01、＜0.01、＜0.01、=0.01、=0.04）;肝衰组PCT[0.50（0.96）]ng/mL、LPS（0.46±0.10）EU/mL、B/E值（0.04±0.01）,乙肝组PCT（0.08±0.02）ng/mL、LPS（0.05±0.02）EU/mL、B/E值（1.62±0.31）,各指标两组间比较差异均具有统计学意义（Z=-3.17,t=5.88,t=16.18,P＜0.01、0.01、0.01）;肝衰组B/E值与LPS水平呈负相关关系（r=‒0.81,P＜0.01）,B/E值与PCT水平呈负相关关系（r=‒0.79,P＜0.01）,且PCT水平与LPS呈正相关关系（r=0.76,P＜0.01）。结论 HBV-ACLF患者肠道菌群失衡导致肠源性LPS生成增多,而肠源性LPS促使PCT产生增多。     

单核细胞趋化蛋白-1、高迁移率族蛋白B1与溃疡性结肠炎患者肠道菌群变化的相关性

目的 探讨单核细胞趋化蛋白-1（MCP-1）、高迁移率族蛋白B1（HMGB1）与溃疡性结肠炎（UC）患者肠道菌群变化的相关性。方法 选取2016年9月‒2018年1月遂宁市中心医院收治的98例UC患者资料,根据Mayo评分系统将UC患者分为活动期组（n=50）和缓解期组（n=48）。选取同期进行体检的健康人50例作为对照组。比较各组间肠道菌群,血清MCP-1、HMGB1水平,并进行Pearson相关分析。结果 活动期组患者肠道乳杆菌、双歧杆菌含量[（5.34±0.87）、（5.81±0.83）CFU/g]显著低于缓解期组和对照组[（8.07±0.86）、（8.35±0.88）CFU/g;（8.13±0.91）、（8.46±0.95）CFU/g]（F=12.035,P0.05）。活动期组和缓解期组患者血清MCP-1、HMGB1水平[（267.42±23.51）、（21.35±2.26）ng/mL;（188.15±20.73）、（6.28±1.38）ng/mL]显著高于对照组[（106.38±15.92）、（2.13±0.41）ng/mL]（F=84.163,P<0.001;F=25.386,P<0.001）;活动期组患者血清MCP-1、HMGB1水平[（267.42±23.51）、（21.35±2.26）ng/mL]显著高于缓解期组[（188.15±20.73）、（6.28±1.38）ng/mL]（t=17.676、39.641,均P<0.05）。经过Pearson相关性分析,MCP-1、HMGB1与UC患者乳杆菌、双歧杆菌含量呈负相关（r=‒0.715、‒0.659,r=‒0.703、‒0.614,均P<0.001）,与大肠埃希菌、肠球菌、拟杆菌含量呈正相关（r=0.783、0.702,r=0.762、0.735,r=0.653、0.612,均P<0.001）。结论 MCP-1、HMGB1作为促炎因子可介导肠黏膜炎性反应,引起UC患者肠道菌群的紊乱。     

皮下种植黑色素瘤对小鼠血液中脂肪和氨基酸代谢的影响*

目的:探讨皮下种植黑色素瘤对小鼠血液中相关脂肪和氨基酸代谢的影响。方法:野生型小鼠皮下种植B16黑色素瘤细胞,两周后观察小鼠并取不同的组织称重,检测血液中甘油三酯、葡萄糖、脂肪酸、炎症因子的水平。利用质谱方法检测血液中氨基酸的水平。结果:野生型小鼠皮下肿瘤种植2周后体重没有明显变化,脾脏和肝脏的重量明显增加,皮下脂肪组织和腹腔脂肪组织的重量没有明显变化。血液中甘油三酯的水平明显增高,葡萄糖和甘油的水平明显下降。血液中炎症因子Interleukin 6(IL6)和Interferon gamma(IFNγ)的水平明显增加。血液的质谱结果显示有四种氨基酸的水平有明显变化,其中胱氨酸(Cystine)增加了约30倍,丝氨酸(Serine)、谷氨酰胺(Glutamine)和色氨酸(Tryptophan)分别有不同程度的降低。结论:皮下黑色素瘤显著影响小鼠机体营养状态和炎症,并特异性影响血液中氨基酸的代谢。