Net -1 frameshifting on a noncanonical sequence in a herpes simplex virus drug-resistant mutant is stimulated by nonstop mRNA

Ribosomal frameshifting entails slippage of the translational machinery during elongation. Frameshifting permits expression of more than one polypeptide from an otherwise monocistronic mRNA, and can restore expression of polypeptides in the face of frameshift mutations. A common mutation conferring acyclovir resistance in patients with herpes simplex virus disease deletes one cytosine from a run of six cytosines (C-chord) in the viral thymidine kinase (tk) gene. However, this mutation does not abolish TK activity, which is important for pathogenicity. To investigate how this mutant retains TK activity, we engineered and analyzed viruses expressing epitope-tagged TK. We found that the mutant's TK activity can be accounted for by low levels of full-length TK polypeptide produced by net -1 frameshifting during translation. The efficiency of frameshifting was relatively high, 3-5%, as the polypeptide from the reading frame generated by the deletion, which lacks stop codons (nonstop), was poorly expressed mainly because of inefficient protein synthesis. Stop codons introduced into this reading frame greatly increased its expression, but greatly decreased the level of full-length TK, indicating that frameshifting is strongly stimulated by a new mechanism, nonstop mRNA, which we hypothesize involves stalling of ribosomes on the polyA tail. Mutational studies indicated that frameshifting occurs on or near the C-chord, a region lacking a canonical slippery sequence. Nonstop stimulation of frameshifting also occurred when the C-chord was replaced with a canonical slippery sequence from HIV. This mechanism thus permits biologically and clinically relevant TK synthesis, and may occur more generally.     

Blood Pressure Effects of Combined β-Blocker and Angiotensin-Converting Enzyme Inhibitor Therapy Compared With the Individual Agents: A Placebo-Controlled Study With Nebivolol and Lisinopril

J Clin Hypertens (Greenwich). 2012; 14:588–592. © 2012 Wiley Periodicals, Inc. Blood pressure (BP) reductions when combining blockers of the renin‐angiotensin system (RAS) and β‐blockers have generally not been shown to be greater than for individual agents, possibly because of overlapping mechanisms of action. The authors tested the additivity of the β‐blocker nebivolol, which has vasodilating activity, with the angiotensin‐converting enzyme inhibitor lisinopril in patients with stage 2 diastolic hypertension. The BP effects of placebo (n=93), nebivolol 5 mg to 20 mg daily (n=185), lisinopril 10 mg to 40 mg daily (n=189), and nebivolol 5 mg to 20 mg + lisinopril 10 mg to 40 mg (n=189) during 6 weeks of treatment were compared. The primary end point was change in diastolic BP (DBP). For the full cohort, baseline BP was 163.8/104.4 mm Hg, mean age was 49.2 years, 58% were men, 62% were white, and 34% were black. DBP fell by 17.2±10.2 mm Hg with the combination, greater than placebo (8.0±9.2, P<.0001), nebivolol (13.3±8.9, P=.0010), and lisinopril (12.0±9.8, P<.0001). For systolic BP, corresponding reductions were 19.2±19.8 mm Hg, 9.9±16.4 (P<.0001 vs combination), 14.4±14.1 (P=.0470), and 16.1±17.2 (P=.0704). Adverse event rates were similar in all groups. This study demonstrated the potential antihypertensive benefits of combining nebivolol with a RAS blocker.     

机器人辅助腹腔镜活体供肾切取术31例报告

目的评估机器人辅助腹腔镜活体供肾切取术的安全性和有效性。方法回顾性分析2013年11月至2015年8月第四军医大学西京医院实施的31例机器人辅助腹腔镜活体供肾切取术的供、受者的临床资料。结果31例均顺利完成供肾切取术,手术时间110~190 min,术中出血量20~100 ml,供肾热缺血时间100~160 s,保留肾静脉长度1.8~3.0 cm,肾动脉长度1.4~2.3 cm。2例供肾取出时发生脾脏损伤,行脾脏修补术;1例供者术后出血,经止血、纠正贫血后好转。31例供者术后均随访6个月以上,均未发生远期并发症。31例受者中,1例出现移植肾功能延迟恢复,经治疗后于术后1个月血清肌酐恢复正常。移植肾存活率为100%。结论机器人辅助腹腔镜活体供肾切取术具有安全、可靠、创伤小、恢复快、不影响供肾功能等优势,可作为供肾切取有效而安全的手术方式。     

柯氏模型在发热门诊支援护士培训效果评价中的应用

目的 探讨发热门诊支援护士培训的实践与效果。方法 对59名发热门诊支援护士进行培训,以柯氏模型作为评价工具,通过培训满意度调查、理论及操作考核成绩、医务人员传染病突发事件应对能力问卷调查、半结构式访谈,从反应层、学习层、行为层及结果层对培训效果进行评价。结果 支援护士总体满意率96.61%;培训后理论及操作考试成绩,传染病突发事件预防能力、准备能力、救援能力得分显著高于培训前（均P<0.05）;半结构式访谈提炼出4个主题：综合能力得到提升、培训规范化、心理感受、培训需进一步优化。结论 开展发热门诊支援护士培训有助于提高其传染病突发事件应对能力、传染病理论知识及操作技能。     

二氧化氯杀菌效果影响因素的研究

为了解二氧化氯含量、作用时间、温度、有机物、溶液pH等因素对二氧化氯杀灭枯草杆菌黑色变种芽孢效果的影响,进行了载体定量杀菌试验。结果,含二氧化氯150mg/L溶液对亚麻布片上枯草杆菌黑色变种芽孢杀灭作用的浓度系数、D值、温度系数分别为:1.599、4.405 min、1.954。50％(ml/ml)小牛血清存在与否,该液作用 10 min的杀芽孢率分别为99.86％与 99.99％;在该液pH为3、5、7时,作用20min的杀芽孢率分别为99.97％、99.90％与99.67％。结果表明,该消毒液杀菌效果随二氧化氯含量增加、作用时间延长、温度升高而增强,酸性条件较好,有机物有一定影响。     

十二指肠非壶腹部神经内分泌肿瘤内镜下切除的回顾性研究

目的 评价内镜超声检查术（EUS）判断十二指肠非壶腹部神经内分泌肿瘤大小和浸润深度的准确性，并对比内镜黏膜下剥离术（ESD）和改良ESD治疗十二指肠非壶腹部神经内分泌肿瘤的有效性和安全性。方法 以2007年1月至2018年1月于中国人民解放军总医院接受ESD（ESD组）或改良ESD（改良ESD组）治疗的22例十二指肠非壶腹部神经内分泌肿瘤患者为研究对象，回顾性纳入患者临床资料。22例患者中，13例行ESD,9例行改良ESD。对比分析ESD组和改良ESD组整块切除率、R0切除率、手术时间、手术相关并发症发生率等指标。以术后病理结果为金标准，评估术前EUS判定病变大小和浸润深度的准确率。结果 22例十二指肠非壶腹部神经内分泌肿瘤大小为（6.9±1.5）mm。与术后组织病理学结果相对照，内镜超声评估病变浸润深度的准确性为95.5%（21/22）。ESD组和改良ESD组的R0切除率分别为13/13和7/9（100.0% 比77.8%, P=1.000）。改良ESD组在手术时间上显著短于ESD组[（16.0±2.2） min 比 （29.8±4.9）min，P<0.001]。ESD组发生1例术中穿孔和1例迟发穿孔，改良ESD组发生1例迟发出血。术后22例患者均成功进行了随访，随访时间为(30.0±24.8)个月。随访期间无患者发生局部复发或者远处转移。结论 内镜超声可以准确评价十二指肠非壶腹部神经内分泌肿瘤的大小和浸润深度。对于直径≤10 mm，浸润深度局限在黏膜下层的十二指肠非壶腹部神经内分泌肿瘤，改良ESD可以获得与ESD相当的临床治疗效果。     

肾缺血-再灌注损伤大鼠SDF-1、ICAM-1表达与肾小管坏死评分的相关性研究

目的探讨肾缺血-再灌注损伤(IRI)大鼠基质细胞衍生因子(SDF)-1、细胞间黏附分子-1(ICAM-1)与肾小管坏死评分的相关性。方法将60只SD大鼠随机分成手术组、假手术组两组,每组各30只。根据手术后检测时间不同,每组再分为6个不同时段的亚组(1、6、12、24、48、72 h组),每个亚组有5只大鼠。手术组建立大鼠肾IRI模型,假手术组大鼠仅予游离双侧肾动脉后缝合切口。检测各个时间点肾功能、肾小管坏死评分及肾脏组织SDF-1、ICAM-1表达变化。对手术组大鼠肾组织SDF-1、ICAM-1表达与肾功能和肾小管坏死评分进行Pearson直线相关分析。结果手术组术后血尿素氮(BUN)、血清肌酐(Scr)较术前及相应时间段假手术亚组明显升高(均为P0.05),且于术后12 h显著升高,高峰期在术后48 h。手术组肾小管坏死评分随时间的延长逐渐增高(均为P0.05);肾小管坏死评分最高在手术48 h组(P0.05)。与手术1 h组比较,手术6 h组大鼠肾组织SDF-1、ICAM-1表达开始明显增多(均为P0.05);手术后48 h达高峰,于手术后72 h开始下降。手术组的肾组织SDF-1、ICAM-1表达与术后各时间段BUN、Scr、肾小管坏死评分呈正相关(r=0.614、0.662、0.751;0.640、0.703、0.785;均为P0.05)。结论当大鼠肾组织发生IRI时,SDF-1、ICAM-1表达上调,BUN、Scr升高,肾小管坏死评分升高,而且SDF-1、ICAM-1的表达与BUN、Scr、肾小管坏死评分呈正相关,提示SDF-1、ICAM-1表达增高程度可以作为反映肾IRI后严重程度的指标。