Sensitive and high sensitivity next generation cardiac troponin assays: more than just a name

In the 20 years that cardiac troponin testing has been available in clinical laboratories, the biomarker has revolutionised testing of patients with acute coronary syndromes. Cardiac troponin I and T testing has become the cornerstone for diagnosis of myocardial infarction and is useful for risk assessment and management of suspected acute coronary syndrome patients. As evidence and knowledge have evolved, it has become clear that even small troponin elevations are associated with adverse health outcomes. As a result there have been several generations of troponin assays, all toward tests that reliably detect lower concentrations of this critical analyte. Guidance for cardiac troponin interpretation has been in the form of myocardial infarction redefinition and evidence-based clinical and analytical guidelines. Although terminology naming generations for cardiac troponin assays has been inconsistent, state-of-the-art cardiac troponin assays are generally referred to as 'sensitive' assays and are in general compliance with analytical guidelines. Evidence shows that use of a sensitive troponin assay can result in diagnosis of myocardial infarction earlier. Next generation cardiac troponin I and T assays will likely be termed 'high sensitivity'; these assays should have the ability to measure troponin with a CV of total error of <10% at concentrations significantly lower than the 99 percentile of the normal reference population. As such, these assays should reliably measure troponin in most normal individuals and detect troponin changes (delta values) below the 99 percentile. This property may result in earlier ACS diagnosis and better management. Utilisation of high sensitivity troponin measurements may be useful for applications other than acute coronary syndromes including risk stratifying patients with renal insufficiency, heart failure, cardiac amyloid and screening elderly patients.     

Peripheral education of the immune system by the colonic microbiota

There is growing interest in understanding the effects of host–microbial interactions on host physiologic processes. Much of the work in this arena is logically focused on the interaction at mucosal surfaces as this is a primary site of interaction. However, there is ample evidence to suggest that the effects of the microbiota have a much farther reach including the systemic immune system. While there are some similarities to effects at mucosal surfaces (i.e. reduced numbers of adaptive immune cells, diminished innate responses), there are some important differences that we highlight such as the response to immunogens and bacterial antigens. We propose that understanding the details of how specific components of the microbiota influence the systemic immune system likely will have significant impact on our understanding the pathophysiology of a variety of autoimmune diseases.     

Natural Protection of Spring and Well Drinking Water Against Surface Microbial Contamination. II. Indicators and Monitoring. Parameters for Parasites

Abstract

Recent outbreaks of cryptosporidiosis and reports of other newly described para-sitic diseases associated with drinking water transmission prompted a reevaluation of source water monitoring criteria for public health protection. The field of microbial indicators was reviewed and each candidate sentinel evaluated in terms of its sensitivity, specificity, and technical feasibility. In addition, a clear distinction was made between source water monitoring and monitoring in the distribution system. Of all potential candidate microbial sentinels, Escherichia coli is deemed the most efficacious for public health protection. Based on a conservative estimate of its half-life in groundwater for 8 d. it is recommended that at least two samples be obtained during this half-life. In addition to E. coli, two water quality indicator sentinels, which are not necessarily direct public health threats, should also be monitored at the same frequency. These are the total coliform group and the enterococci. If E. coli is present in any source water sample, the borehole and any directly connected borehole should be embargoed. If either total coliforms or enterococci are detected, only that individual borehole should be taken off line and not used until the situation is remediated and the cause of the fecal contamination eliminated. Clostridium perfrigens spores serve as a useful long-lived indicator. However, their perseverance in a sample should not be considered a direct public health threat because spores may far outlive pathogens. As a parasite indicator, C. perfringens should have the same importance as a positive colifom or enterococcus analysis. Coliphages do not yet fulfill enough of the criteria to be routinely employed. Biological monitoring should be coupled with physicochemical monitoring to establish a long-term history of the source. Because all natural waters vary in the amounts of heterotrophic plate count bacteria, test methods should be employed that are refractory to them. A combination of rigorous source protection plus extraordinary source monitoring serve as sufficient multiple barriers for parasite protection.     

Effects of microbial metabolites on catalase activity and growth of Staphylococcus aureus 6538 P

The effects of cell extracts and supernatants ofLactobacillus spp. andCorynebacterium spp. on catalase activity and growth ofStaphylococcus aureus 6538 P were studied. Intra- and extracellular metabolites of lactobacilli and corynebacteria inhibited catalase activity ofS. aureus 6538 P. The growth ofS. aureus 6538 P decreased after incubation with lactobacillus metabolites. The inhibitory effect of intra- and extracellular metabolites of lactobacilli and corynebacteria on catalase activity ofS. aureus is a possible pathway of microbial interrelations responsible for the formation and/or development of microbial biocenoses. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 7, pp. 80–82, July, 2000     

2004年度我院细菌检测结果及耐药性分析

目的监测我院2004年临床可疑细菌感染标本的分离培养及细菌耐药状况。方法对我院从2004年1月19日—2004年12月31日分离的235株细菌,按常规操作规程进行,必要时应用BD公司的BBLCRASTAL鉴定系统。药敏试验采用WHO推荐的K-B纸片扩散法测定细菌对药物的敏感性。结果培养率最高的细菌为大肠埃希菌、金黄色葡萄球菌、铜绿假单胞菌、肺炎克雷伯菌、白色假丝酵母菌等。碳青霉烯类是革兰阴性杆菌(除嗜麦芽窄食单胞菌)抗菌作用最强的抗生素。头孢哌酮/舒巴坦、头孢他啶、左氧氟沙星对革兰阴性杆菌也有很好的抗菌活性。但仍有40%~55%的大肠埃希菌对氟喹诺酮类耐药。结论头孢哌酮/舒巴坦、左氧氟沙星、环丙沙星、庆大霉素和妥布霉素对非发酵阴性杆菌的抗菌谱较广,抗菌作用也较好,另外一些耐药菌株的出现应引起我们注意。     

飞行疲劳对不同年龄民航飞行人员视觉融合的影响

目的 探讨跨时区长时间飞行中飞行疲劳与年龄因素的关系,为年大飞行人员延长飞行年限提供试验依据.方法 采用临界闪光融合频率（CFF）检测、划消测验等方法,对执行不同航线跨时区运输任务的中国国际航空公司47名男性飞行人员（年龄27～58岁）,在飞行前1 d、空中飞行3 h、6 h、9 h和落地后当天、第2天、第3天晚上睡觉前进行7次测试.对测试结果进行重复测量的多因素方差分析和均数差异检验.结果 CFF值和划消测验成绩在飞行3 h、6 h、9 h的过程中逐步降低,飞行9 h下降到最低点.多因素方差分析表明,不同检测时间为主要变异源,时差效应和工种效应均不明显（P＞0.05）.年龄因素对CFF值未产生显著影响（F=1.38,P=0.26）.划消测验成绩与年龄因素显著相关（F=8.50,P＜0.01）,成绩差异主要存在于40岁以下（含）和41岁以上（含）飞行人员之间.41岁至58岁飞行人员的数字划消成绩基本上处于同一水平（P=0.53）.结论 对41岁至58岁飞行人员来说年龄不是导致飞行疲劳的主要因素,本研究结果支持有限制地特许延长部分年大飞行人员飞行年限.     

地衣芽胞杆菌对肠道致病菌的体内拮抗作用研究

目的:探讨地衣芽胞杆菌C01在模型小鼠体内对大肠杆菌、沙门氏菌抑制作用以及对乳杆菌等有益菌的促进作用。方法:用地衣芽胞杆菌C01灌胃肠道感染模型小鼠,采用体外活菌培养,分析粪便菌群数量的变化。结果:C01灌胃治疗组(EPEC C01)中乳杆菌的数量显著高于EPEC灌胃模型组(EPEC N)(P<0.01),肠杆菌数量下降极显著(P<0.01),而(EPEC N)组肠杆菌数显著高于正常对照组(NS)(P<0.05);肠炎沙门氏菌处理后C01灌胃治疗组(SL C01)和处理后肠炎沙门氏模型组(SL N)比较,乳杆菌、肠球菌和总厌氧菌的变化不明显,但肠杆菌数量下降极显著(P<0.01);形态病理学观察结果显示,C01芽胞杆菌灌胃治疗组肠粘膜病变明显减轻,肠粘膜及绒毛高度明显增加,绒毛轻度水肿,绒毛排列整齐、致密。结论:地衣芽胞杆菌C01在体内对肠炎沙门氏菌和致病性大肠杆菌有较强的抑制作用,能促进乳杆菌等生理性有益菌的增殖,可保护肠粘膜结构的完整性免受病原菌的侵袭。     

直接饲喂微生物在奶牛生产中的研究进展

直接饲喂微生物(direct-fed microbial,DFM),亦称益生菌,被认为是目前较好的抗生素替代品.本文就DFM作用机理和对奶牛的生产性能的影响作了论述,并就今后的发展趋势作了探讨.     

微生物胞外多糖--热凝胶的酶法提取

采用中性蛋白酶处理热凝胶胞外多糖发酵液,降解其中的菌体,实验证明,与传统的酸碱法相比,中性蛋白酶法更能有效地对热凝胶多糖发酵液提纯,而且保持了其主要性能--热成胶性.进一步确定了酶法提取纯化热凝胶的最优条件,获得的多糖产品为纯一的β-(1,3)葡聚糖,且有效地去除了蛋白质等杂质.