Membrane insertion and topology of the p7B movement protein of Melon Necrotic Spot Virus (MNSV)

Cell-to-cell movement of the Melon Necrotic Spot Virus (MNSV) is controlled by two small proteins working in trans, an RNA-binding protein (p7A) and an integral membrane protein (p7B) separated by an amber stop codon. p7B contains a single hydrophobic region. Membrane integration of this region was observed when inserted into model proteins in the presence of microsomal membranes. Furthermore, we explored the topology and targeting mechanisms of full-length p7B. Here we present evidence that p7B integrates in vitro into the ER membrane cotranslationally and with an Nt-cytoplasmic/Ct-luminal orientation. The observed topology was monitored in vivo by fusing GFP to the Ct of p7B, enabling the overexpression in Escherichia coli cultures. Finally, the topology of a putative p14 movement protein was established by replacing the amber stop codon located between p7A and p7B.     

Accuracy of N‐terminal‐pro‐atrial natriuretic peptide in patients admitted to emergency department

Objective. B‐type natriuretic peptide (BNP) and N‐terminal‐pro‐BNP (Nt‐proBNP) are commonly used for the triage of patients in the emergency department (ED) with dyspnoea and/or chest pain. The aim of our study was to determine the accuracy of N‐terminal‐pro‐ANP (Nt‐proANP) in such patients. Material and methods. Nt‐proANP was measured by home‐made radioimmunoassay in 137 ED patients admitted with cardiovascular and/or pulmonary disorders. BNP and Nt‐pro‐BNP were determined with automated assays. Final diagnosis was confirmed at discharge or after follow‐up. Results. Nt‐proANP levels were significantly influenced by the diagnostic subgroups (ANOVA: p<0.001) and were [geometric mean (range)]: 19727?ng/L (5260–45200) in congestive heart failure (CHF, n = 31), 6575?ng/L (1350–36000) in coronary artery disease (CAD, n = 19), 5324?ng/L (1710–13150) in pulmonary embolism (PE, n = 20), 5035?ng/L (1510–16600) in pulmonary diseases (PD, n = 24) and 3001?ng/L (750–11860) in patients without cardiopulmonary diseases (n = 43). Pairwise comparisons demonstrated that CHF patients had Nt‐pro‐ANP values higher than all other groups (p<0.05) and that patients without cardiopulmonary diseases had the lowest values (p<0.05). For diagnosis of CHF, the area under the ROC curve of Nt‐proANP was 0.94 (95?% CI: 0.89–0.98) and was equivalent to Nt‐proBNP (0.91; p = 0.284) and BNP (0.93; p = 0.572). Conclusions. The diagnostic accuracy of Nt‐proANP was equivalent to BNP and Nt‐proBNP in the present cohort of patients admitted to ED with dyspnoea and/or chest pain.     

酶联免疫吸附试验与中和抗体试验检测麻疹抗体比较研究

目的探讨酶联免疫吸附试验(ELISA)和中和抗体试验(NT)在麻疹抗体检测中的应用价值。方法以NT为"金标准",同时用德国Virion/Serion的定量ELISA试剂盒检测364份麻疹抗体滴度,将两种方法测定的结果进行比较。结果 NT的阳性率为57.69%,几何平均滴度(GMT)为1∶5.48,ELISA的阳性率为42.86%,平均抗体活性值为48.57IU/L。定性结果发现,ELISA特异度为99.35%,其敏感度即阳性符合率为73.81%,且阳性符合率随着滴度增加呈现增高的趋势(z=-5.99,P<0.001)。Fisher精确概率法发现,滴度1∶2组、滴度1∶4组与其他各组阳性符合率差异均有统计学意义(P<0.05),滴度1∶8组与滴度≥1∶64组阳性符合率差异有统计学意义(P<0.05),其余各组间阳性符合率差异均无统计学意义(P>0.05)。定量结果发现,ELISA抗体活性值与NT滴度呈明显正相关,相关系数r=0.884,P<0.001。结论德国Virion/Serion的定量ELISA试剂盒在检测低滴度麻疹抗体时易出现假阴性,检测高滴度麻疹抗体时,两种方法敏感性接近;滴度临界值为1∶8～1∶16。该试剂可推荐用于健康人群麻疹抗体水平监测。     

Nt‐proBNP in haemodialysis patients: A preliminary study

Objective. N‐terminal pro‐brain natriuretic peptide (Nt‐proBNP) is a marker of left ventricular function. Although many factors can increase left ventricular dysfunction in haemodialysis patients, the role of Nt‐proBNP is uncertain. Material and methods. Serum concentrations of Nt‐proBNP and troponin T were measured by electrochemiluminescence and C‐reactive protein by immunoturbidimetry in 52 dialysis patients followed‐up for 36 months. Results. Nt‐proBNP correlated (p<0.05) with time on haemodialysis (rho = 0.345), left ventricular mass index (r = 0.596), troponin T level (r = 0.605) and age (r = 0.296). Patients with a history of heart disease showed higher levels of Nt‐proBNP (median; minimum‐maximum ngl/L) (15,571; 1,553–209,451) than those without (4,535; 751–115,078) (p<0.01). Sensitivity and specificity of Nt‐proBNP in the detection of left ventricular dysfunction (ventricular ejection fraction <45?%) were 1.0 and 0.782, respectively. In the univariate analysis, patients with Nt‐proBNP levels ?33,314?ng/L, CRP ?5?mg/L or troponin T ?0.1?µg/L had poorer probabilities of 1‐year, 2‐year and 3‐year survival than patients with lower levels. Unfavourable prognostic factors in the multivariate analysis were CRP >5?mg/L and Tn T >0.1?µg/L. Conclusions. Nt‐proBNP showed good diagnostic performance for detecting left ventricular dysfunction and was an important predictor of mortality in haemodialysis patients in the univariate analysis. In the multivariate analysis, Nt‐proBNP lost its prognostic value, whereas for CRP and Tn T it was maintained.     

Preparation-free method can enable rapid surfactant screening during industrial processing of influenza vaccines

Triton X-100 (TX-100) is the most common surfactant used to split viruses during the production of influenza split-virus vaccines. It is a mild surfactant not known to denature the viral proteins; this property makes TX-100 useful for maintaining antigen conformational structure, and, as an added benefit, for partially stabilizing vaccine formulations against protein aggregation. Despite its benefits, TX-100 needs to be filtered out after virus splitting has been achieved, due to its toxicity in large quantities. Accordingly, residual TX-100 presence in vaccine formulations has implications for both formulation stability and safety, necessitating both accurate screening during processing to guide decision-making about filtration repeats and accurate quantitation in the final product. Accurate HPLC-based methods are used successfully for the latter but their use for routine screening during processing is far from ideal because they often require extensive sample preparation and are fairly slow, complicated and costly. Here, “deconstruction” of UV–Vis absorption spectra into components corresponding to different absorbing “species” is demonstrated as a novel and viable method for routine TX-100 screening in vaccine samples from different industrial processing steps. This method is fairly accurate and, more importantly, preparation-free, rapid, simple/user-friendly and comparatively inexpensive. It is evaluated in depth in terms of applicability conditions, limitations and potential for high-throughput adaptation as well as generalization to other complex biopharmaceutical formulations.     

DNA structural alterations induced by bis-netropsins modulate human DNA topoisomerase I cleavage activity and poisoning by camptothecin

Bis-netropsins (bis-Nts) are efficient catalytic inhibitors of human DNA topoisomerase I (top I). These DNA minor groove binders are considered to serve as suppressors of top I-linked DNA breaks, which is generally believed to be related to their affinity to DNA. In this study, it was found that bis-Nts exhibit sequence-specificity of suppression of the strong top I-specific DNA cleavage sites and that this sequence-specificity is determined by differential ligand-induced structural alterations of DNA. Raman scattering analysis of bis-Nts interactions with double-stranded oligonucleotides, each containing the site of specific affinity to one of bis-Nts and a distinctly located top I degenerate consensus, demonstrated that bis-Nts induce not only structural changes in duplex DNA at their loading position, but also conformational changes in a distant top I-specific DNA cleavage site. The ability to alter the DNA structure correlates with the anti-top I inhibitory activities of the ligands. In addition, DNA structural alterations induced by bis-Nts were shown to be responsible for modulation of the camptothecin (CPT)-mediated DNA cleavage by top I. This effect is expressed in the bis-Nts-induced enhancement of some of the CPT-dependent DNA cleavage sites as well as in the CPT-induced enhancement of some of the top I-specific DNA cleavage sites suppressed by bis-Nts in the absence of CPT.     

硝普钠多巴胺治疗低血压并慢性心衰评价

目的 观察硝普钠、多巴胺与利尿剂合用治疗低血压合并慢性充血性心衰的疗效、安全性及其对患者血浆氨基末端脑钠肽(Nt-proBNP))浓度的影响.方法 将105例心衰患者随机分为治疗组和对照组,对照组给利尿剂与氨茶碱治疗;治疗组在对照组基础上加用硝普钠与多巴胺,观察10d,并对两组的心功能改善、症状改善及心脏彩超进行对比,并采用ELISA法对两组患者治疗前后血浆Nt-proBNP进行测定.结果 治疗组总有效率94.5%,显效率60.2%,治疗后左室射血分数(LVEF)显著高于对照组(P＜0.05);治疗组治疗后血浆Nt-proBNP水平显著低于对照组(P＜0.05).结论 硝普钠与多巴胺联用在治疗低血压合并慢性充血性心衰中有重要意义,血浆Nt-proBNP水平在心衰治疗疗效评价中有较高敏感性.     

甲型H1N1流感合并侵袭性肺曲霉病的诊治

1临床资料 患者男，22岁，因咳嗽、咳痰、发热1周，咯血、气促1d于2009年11月22日入院。患者既往体健，2009年11月15日无明显诱因出现咳嗽，咳白色黏液痰，伴发热，无胸痛、气促、盗汗、乏力等。11月21日凌晨4时突然咯血约40mL，于当日8时到外院就诊，并再次咯血约200mL，摄片检查胸片示两上中下肺淡薄模糊影，右中肺融合成团片状密集影，诊断为肺结核转诊我院。     

Brain Activation of Unpleasant Emotions Increases Catastrophizing in Patients with Chronic Pain

BackgroundCatastrophic thinking among patients with chronic pain impairs their quality of life and increases anxiety levels. Further, severe pain causes high emotional brain sensitivity and unpleasant feelings. However, the effects of emotional changes on catastrophic thinking in patients with chronic pain remain unclear.AimsWe hypothesised that emotional brain activity during mild pain stimuli would affect catastrophic thinking in these patients. We aimed to examine the relationship between unpleasant emotional brain activation and catastrophic thinking due to pain stimuli in patients with chronic pain.DesignThis was a prospective observational study.ParticipantsWe included patients with chronic pain and healthy individuals.MethodsThe impact of emotional brain activity on catastrophic thinking was evaluated, specifically, the skin conductance response and oxygenated haemoglobin levels using near-infrared spectroscopy. After receiving three different pain stimuli, the participants were evaluated using the Numeric Rating Scale, Pain Catastrophising Scale, and McGill Pain Questionnaire.ResultsThere were 28 patients in the chronic pain group and 33 patients in the healthy group. There was no between-group difference in oxygenated haemoglobin levels during pain stimulation. The chronic pain group showed a higher Pain Catastrophising Scale score and skin conductance response than the healthy group (p < .05). In the chronic pain group, oxygenated haemoglobin levels after pain stimuli were significantly associated with the Pain Catastrophising Scale score and skin conductance response (p < .05).ConclusionsBrain activity of unpleasant emotions may influence catastrophic thinking in patients with chronic pain.