SIRT3 regulation of mitochondrial oxidative stress

Mitochondria play a central role in the production of reactive oxygen species as byproducts of metabolism and energy production. In order to protect cellular structures from oxidative stress-induced damage, cells have evolved elegant mechanisms for mitochondrial ROS detoxification. The mitochondrial sirtuin, SIRT3, is emerging as a pivotal regulator of oxidative stress by deacetylation of substrates involved in both ROS production and detoxification. This review will summarize recent findings on the regulation of mitochondrial ROS homeostasis by SIRT3.     

Improved knowledge and practices among end-users of mother-to-child transmission of HIV prevention services in rural Zimbabwe

OBJECTIVE: To evaluate the influence of a prevention of mother-to-child transmission of HIV advocacy and mobilization campaign on awareness and knowledge levels within the community. METHOD: We used a knowledge, attitudes and practices survey to collect baseline data in November 2002 and again in July 2004 for evaluation purposes. RESULTS: A total of 351 women attending healthcare services were interviewed each time. The proportion of women aware of the service increased from 48.0% in 2002 to 82.8% in 2004 (OR = 4.9, 95% CI 3.3-7.3, P = 0.001). Exclusive breastfeeding was identified as a mother-to-child transmission risk factor by 27.1% in 2002 and by 55.8% of respondents in 2004 (OR = 2.9, CI 2.1-4.2, P = 0.001). Although most interviewees agreed that the prevention of sexual transmission of HIV was the best strategy for prevention of mother-to-child transmission of HIV (88.3% in 2002 and 96.4% in 2004), few reported having ever used a male condom (24.8% in 2002 vs. 29.8% in 2004, P = 0.16). DISCUSSION: Prevention of mother-to-child transmission of HIV strategies at both individual and community level were still insufficiently understood and applied. Targeted educational messages and communication for social change need to be combined. Knowledge, attitudes and practices surveys can be used to monitor programme progress.     

法尼醇X受体对L02细胞脂肪代谢的调节作用

目的 观察法尼醇X受体(FXR)对人肝细胞株L02细胞脂肪代谢的调节作用.方法 油酸钠建立L02细胞脂肪变模型(脂肪变组),油酸钠及鹅去氧胆酸钠建立干预模型(干预组),设对照组(培养基中不加药物),3组均设立24、48、72 h时间点.油红O染色,细胞内甘油三酯含量测定,检测肝细胞脂肪变程度;Westem blot和RT-PCR方法检测核受体FXR及固醇调节元件结合蛋白1c(SREBP-1c)的表达变化.结果 脂肪变组随着肝细胞脂肪变性的发生发展,FXR表达呈逐渐降低趋势,但差异无统计学意义.SREBP-lc mRNA的表达明显升高,24、48,72 h图像半定量分析结果分别为0.495±0.062、0.579±0.064、0.612±0.067,SREBP-1c蛋白表达分别为0.394±0.044、0.488±0.066、0.543±0.064,均明显高于干预组和对照组,差异有统计学意义.干预组FXR mRNA表达明显上调,24、48,72 h分别为0.253±0.041、0.298±0.042、0.334±0.051,FXR蛋白分别为0.221±-0.022、0.313±0.041,0.341±0.046,与脂肪变组比较,,值为6.41～50.93,Jp值均<0.05或0.01,差异有统计学意义.脂变组甘油三酯含量各时间段均明显增加,干预组甘油三酯含量各时间段均明显降低.差异有统计学意义.结论 FXR表达下调与肝细胞脂肪沉积密切相关;刺激FXR表达增加可能通过抑制其靶基因SREBP-1c表达而改善L02细胞脂肪变性.     

北京大型建筑工地农民工性行为与艾滋病知识知晓率相关性研究

目的了解农民工性行为与艾滋病防治知识知 晓率的相关性,为制定大城市建筑工地农民工艾滋病防治策略提供科学依据。方法对北京市2家大型建筑工地的农民工开展问卷调查,进行统计学描述。结果调查的371名农民工中,知晓艾滋病的187人（50.40%）,不知晓的184人（49.6%）。有固定性伴（配偶或女朋友）的农民工、找女性性服务者的农民工和有临时性伴的农民工,其艾滋病知识知晓率分别为47.37%、66.67%和50%;每次均使用安全套的比例分别为5.26%、66.67%和25%;找女性性服务者和找临时性伴发生性行为与艾滋病知晓率之间差异无统计学意义（χ^2=0.38,P〉0.01）。艾滋病知识是否知晓与是否找女性性服务者和临时性伴之间没有相关性。但对艾滋病知识知晓的农民工在高危性行为时,安全套的使用率要明显高于不知晓的农民工（χ^2=41.28,P〈0.005）。存在以异性为主（1.35%）及同性为主（0.54%）的性取向。结论农民工中艾滋病防治知识知晓率低,存在艾滋病知识和发生高危险性行为的分离现象;应关注农民工中男男性行为的现象。应在农民工中采取同伴教育等多种形式,加大宣传艾滋病防治知识,推广安全套的使用,以减少危险性行为的发生。     

慢性乙型肝炎患者疾病相关认知度及抗病毒治疗现状调查分析

目的调查CHB患者疾病相关知识的认知情况及其抗病毒治疗现状,分析患者对疾病相关知识的认知度与接受抗病毒治疗的相关性。方法依据CHB疾病相关知识设计调查问卷,对2011年10月至2013年10月首都医科大学附属北京地坛医院收治的CHB队列中部分患者进行问卷调查。结果本次调查共发放问卷930份,回收有效问卷881份（有效率94.73%）。将患者对疾病相关知识的认知程度分为较差、一般、较好3个层次。881例患者中,对预防知识的认知较差、一般、较好比例分别为17.71%、30.76%、51.53%,对基础知识的认知比例分别为22.02%、38.71%、39.27%,对治疗知识的认知比例分别为57.43%、15.89%、26.67%。正在进行抗病毒治疗的患者548例,占患者总数的62.20%,疾病相关综合知识认知较差组CHB患者抗病毒比例明显低于其他组CHB患者。结论目前患者对CHB疾病相关知识认知较差,医务人员应加强对患者的宣教。     

The influence of the bone-implant interface stiffness on stress profiles surrounding Al2O3 and carbon dental implants

Dental implants have been used and studied for the replacement of missing teeth for many years. Finite element stress analysis (FESA) has previously been used in their evaluation to study the effect of various design parameters on induced stresses. A twodimensional FESA was used to evaluate the effect that the implant-bone interface elastic modulus has on the stress distribution around LTI carbon and aluminum oxide dental implants. The results of this investigation indicate that a soft tissue interface between implants and bone negates the effect of implant elastic modulus and results in stress profiles that were almost identical for the LTI carbon and aluminum oxide implants. This research was supported by NIH Grants DE 04653, DE 0041, and AM 0022, and VA Grant V629P-713.     

随动载荷对腰椎小关节接触力的影响

目的研究不同大小随动载荷在腰椎不同姿态下对小关节接触力的影响。方法建立非线性三维有限元腰椎模型(L1~S1),并考虑小关节软骨的非均一厚度和非线性材料特征。对腰椎模型施加不同大小的随动力预载荷(0、0.5、0.8、1.2 k N)以及7.5 N·m不同方向上(前屈、后伸、侧弯、轴向旋转)的纯力矩,对比各运动节段两侧小关节上在不同加载工况下的接触力,并定量研究随动载荷对小关节不对称性的影响。结果随动载荷的应用会增大屈伸以及侧弯(同侧)状态下的小关节接触力,而减少侧弯(对侧)时的小关节接触力,而且这种增大(或减小)效应会随着随动载荷本身的增大而减弱。对于轴向扭转,预载荷对小关节力几乎没有影响。在腰椎不同的姿态下,随动载荷对于小关节接触力不对称性的影响按从大到小排列依次为:侧弯(同侧)、前屈、侧弯(对侧)、后伸、轴向扭转。结论随动载荷对腰椎小关节接触力的影响随腰椎运动姿态的不同而不同。在腰椎的生物力学研究中,小关节的不对称性需要被充分考虑,尤其是在生理载荷作用下腰椎后部结构的研究中。     

锌、铜、镁含量在ICP及FGR母体血清中含量的变化

目的探讨妊娠期肝内胆汁淤积症(ICP)及胎儿生长受限(FGR)患者血清中锌、铜、镁含量的变化。方法以原子吸收分光光度法分别测定35名ICP患者、11例FGR患者及20例正常妊娠女性血清锌、铜、镁浓度。结果ICP患者血清锌含量为0.40±0.16μg/mL,较对照组明显降低(P0.05),铜含量1.88±0.43μg/mL,镁含量0.66±0.73μg/mL,均与对照组无显著性差异(P0.05);FGR组铜含量2.31±0.53μg/mL,较对照组明显升高,锌含量为0.46±0.13μg/mL,镁含量为0.47±0.44μg/mL,均较对照组明显降低,有显著性差异(P0.05);ICP组铜含量较FGR组低,有显著性差异(P0.05),而锌、镁含量两组相比较无显著性差异(P0.05)。结论针对孕妇血清锌、铜、镁含量变化进行饮食调整对孕期健康有重要意义。