环境中条件致病菌对无机砷毒性降解作用

目的 研究环境中几种常见的条件致病菌对无机砷的降解作用.方法 各菌株接种在不同浓度含砷培养基中,观察其对砷的耐受性及砷对各菌株的生长影响;利用超声波细胞粉碎机震碎菌体后,用超低温捕获原子吸收分光光度仪检测砷含量,用荧光光谱检测器检测砷形态.结果 实验所用各菌株均可耐受1 000 mg/L无机砷的浓度,养基中无机砷浓度<1 mg/L时对细菌的生长影响不大,无机砷浓度>1 mg/L时在短时间内可抑制细菌的生长,但随着培养时间的延长,细菌会耐受这种高砷环境.结论 实验菌株对无机砷均具一定的降解作用.     

臭氧水灭菌效果的试验观察

目的 测定高效电解臭氧消毒治疗机在不同浓度、对不同菌株的杀菌效果，为其临床应用提供依据。方法 在不同条件下，用臭氧水对菌悬液进行消毒，定量培养，计算杀菌率。结果 在5mg/L浓度下对标准菌株大肠埃希菌(ATCC8099)、金黄色葡萄球菌(ATCC25923)、白色念珠菌(ATCCl0231)作用1min杀灭率可达100％，对枯草杆菌芽胞(ATCC9372)作用10min杀灭率可达99．99％；用临床菌株试验，在5mg/L浓度下作用0．5min，对金黄色葡萄球菌、大肠埃希菌、白色念珠菌的杀灭率为100％，在1．25mg/L浓度对金黄色葡萄球菌、大肠埃希菌、白色念珠菌、铜绿假单胞菌的杀灭率均＞99．3％。结论 高效电解臭氧消毒治疗机产生的臭氧水具有快速、高效杀菌作用。     

纳米银对多重耐药菌的抑菌效果研究

目的 探讨纳米银对多重耐药菌的抑菌效果。方法 制备金黄色葡萄球菌的标准菌株和耐甲氧西林菌株,大肠埃希菌的标准菌株和产ESBLs菌株悬液并与终浓度80、100、120、140 mg/L四个浓度纳米银溶液混合处理,分别于处理前和处理后10、20、30、40 min取混合菌液培养,计数菌悬液菌落数,分析纳米银不同浓度,不同处理时间对四种菌株的抑菌率。比较纳米银溶液对不同种细菌之间,同种耐药菌株和标准菌株之间的抑菌率差别,分析纳米银的抑菌效果。结果 纳米银溶液浓度120 mg/L时,作用30 min就能完全抑制0.5麦氏浊度的所有大肠埃希菌标准菌株和产ESBLs菌株,而完全抑制0.5麦氏浊度的金黄色葡萄球菌标准菌株和耐甲氧西林菌株需要纳米银溶液浓度120 mg/L作用40 min或140 mg/L作用30 min。120 mg/L浓度纳米银处理20 min对大肠埃希菌标准株的抑菌率为(72.42±5.50)%,高于对金黄色葡萄球菌标准株的抑菌率(55.67±7.62)%,差异有统计学意义(t=5.64, P=0.000)。纳米银对产ESBLs大肠埃希菌菌株的抑菌率为(71.51±5.56)%,高于对耐甲氧西林金黄色葡萄球菌菌株的抑菌率(53.78±5.90)%,差异有统计学意义(t=6.91, P=0.000))。纳米银抑菌率在大肠埃希菌标准菌株和产ESBLs菌株之间,金黄色葡萄球菌标准菌株和耐甲氧西林菌株之间差异无统计学意义(P>0.05)。结论 纳米银对革兰氏阴性杆菌的抑菌能力高于革兰氏阳性球菌,而对同种菌的耐药和敏感菌株的抑菌能力无明显性差异。     

双黄连粉针剂对产ESBLs大肠埃希菌的体外抑菌作用

目的:通过双黄连粉针剂在体外对产ESBLs大肠埃希菌抑菌作用的研究,验证中药制剂对耐药菌的抑制作用,并探讨中西药联合应用对耐药菌的作用效果。方法:采用全自动微生物鉴定和药敏分析系统(VITEK-32)对细菌耐药性进行鉴定和表型筛选;参照临床和实验室标准研究所(CLSI)推荐的纸片扩散法对初步筛选的可疑菌株进行确认;参照临床和实验室标准研究所(CLSI)推荐的肉汤稀释法,研究双黄连粉针剂、双黄连粉针剂联合舒普深对产ESBLs大肠埃希菌的体外抑制作用。结果:双黄连对产ESBLs的大肠埃希菌的药物最低抑菌浓度(MIC)为70 mg/ml;舒普深对产ESBLs的大肠埃希菌的MIC为31.25μg/ml;双黄连和舒普深联合作用于产ESBLs的大肠埃希菌,双黄连浓度60 mg/ml作用6 h后,再用舒普深浓度15.625μg/ml即可抑制产ESBLs大肠埃希菌的生长,与单用双黄连比较,双黄连浓度降低了14.3%,与单用舒普深比较,舒普深浓度降低了50%。结论:双黄连对产ESBLs大肠埃希菌有一定的抑制作用,双黄连与舒普深联合应用(间隔6 h)在体外能够增强舒普深对产ESBLs大肠埃希菌的抑菌作用。     

大肠埃希菌多药耐药株对常用消毒剂的抗力试验观察

目的 研究临床分离的大肠埃希菌多药耐药株对消毒剂的抗力水平,同时了解消毒剂在常用浓度下对多药耐药株的消毒效果.方法 采用最低抑菌浓度(MIC)测定试验与悬液定量杀菌试验,以大肠埃希菌标准株作对照,对临床分离的大肠埃希菌多药耐药株进行苯扎溴铵等4种消毒剂的抗性变化和消毒效果的试验观察.结果 苯扎溴铵、碘伏对21株大肠埃希菌多药耐药株MIC值分别有61.9%、71.4%的菌株高于标准株;对"84"消毒液MIC值有14.3%的菌株高于标准株,所有菌株对过氧乙酸MIC值与标准株相同;4种消毒剂在常用浓度下对大肠埃希菌多药耐药株作用5 min杀灭率为100.0%.结论 临床分离的大肠埃希菌多药耐药株对苯扎溴铵和碘伏的抗力高于标准株;4种消毒剂在常用浓度下对临床分离大肠埃希菌多药耐药株消毒有效.     

纳米银体外抑菌效果的试验观察

目的探讨不同浓度的纳米银溶液对细菌和真菌的抑菌作用。方法采用抑菌环试验及最低抑菌浓度试验对不同浓度的纳米银溶液抑制细菌及真菌的效果进行观察。结果抑菌环结果显示,含≥5mg/L的纳米银溶液对金黄色葡萄球菌、铜绿假单胞菌和大肠埃希菌有抑菌作用,含≥10mg/L的纳米银溶液对白色假丝酵母菌有抑菌作用;纳米银溶液对白色假丝酵母菌的最低抑菌浓度为10mg/L,对金黄色葡萄球菌、铜绿假单胞菌、大肠埃希菌的最低抑菌浓度为5mg/L。结论较小浓度的纳米银溶液对细菌及真菌有较好的抑菌作用。     

以绿色荧光蛋白为报告基因的环境砷离子生物检测体系的构建

目的 建立环境中砷的生物检测方法.方法 根据GenBank中已发表的革兰阳性菌中参与砷抗性机制的操纵子序列R46 ars,人工合成arsR全部序列(含小部分arsD基因序列)及其上游的启动子序列,以绿色荧光蛋白基因为报告基因,构建含砷离子特异性诱导启动子表达载体pET28a(+)-ars-gfp,并采用感受态转化法将该重组表达载体转化入大肠埃希菌表达宿主菌Escherichia coli BL21(DE3)中,构建砷离子检测菌株,并进行PCR和酶切鉴定.结果 通过PCR和酶切鉴定,表明重组表达载体成功构建并转化入大肠杆菌E.coli BL21 (DE3),绿色荧光蛋白报告基因在有砷离子(0.2～1.0μmol/L)存在的环境中得到表达.结论 该菌株适用于环境中砷的生物检测.     

不同抗菌药物诱导革兰阴性菌释放内毒素的体外试验研究

目的检测不同抗菌药物作用不同时间诱导革兰阴性菌释放内毒素(LPS)的浓度,为抗感染治疗预防内毒素血症提供依据。方法试验于2014年8-10月进行,将1麦氏浊度各菌株菌悬液0.5ml与不同浓度的抗菌药物0.5ml溶液混匀,得到0.5个麦氏浊度的待测溶液,将待测菌悬液0.2ml直接加入反应主剂中溶解,使用微量加样器转移至10mm×75mm标准玻璃反应管中,用MB-80微生物快速动态检测系统检测内毒素浓度,使用SPSS17.0进行统计处理。结果阿米卡星(0.125mg/L)与大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍氏不动杆菌作用1min释放的LPS差异无统计学意义,阿米卡星浓度为2、8mg/L时大肠埃希菌释放LPS与其他3种菌相比差异均有统计学意义(P<0.05),美罗培南0.125mg/L、阿米卡星2mg/L、头孢哌酮/舒巴坦64mg/L与大肠埃希菌作用3min与1min时的LPS检测值差异均有统计学意义(P<0.05),美罗培南0.125mg/L、阿米卡星2mg/L、哌拉西林/他唑巴坦16mg/L、头孢他啶32mg/L、头孢哌酮/舒巴坦64mg/L与肺炎克雷伯菌分别作用3、5、10min检测的LPS结果的差异无统计学意义。结论不同抗菌药物浓度、不同作用时间诱导革兰阴性菌内毒素释放的水平有影响,同一抗菌药物对不同革兰阴性细菌诱导释放内毒素的能力也不同,临床使用抗菌药物治疗革兰阴性菌引起的感染时,应尽量减少抗菌药物诱导内毒素升高引起的内毒素血症危害。     

某84消毒液杀菌效果及毒性实验观察

目的 了解一种以次氯酸钠为主要成分的液体消毒剂的杀菌效果、稳定性及毒性.方法 采用悬液定量杀灭试验、自然留样稳定性试验等方法进行实验研究.结果 该消毒剂含有效氯1 000 mg/L、600 mg/L的溶液对悬液中金黄色葡萄球菌、大肠埃希菌分别作用7.5 win、40 min的杀灭对数值≥5.00;含有效氯1 000 mg/L的溶液作用30min对物体表面自然菌各次试验的平均杀灭对数值均≥1.00;含有效氯600 mg/L的溶液作用40 min对黄瓜上染的大肠埃希菌的杀灭对数值≥3.00.能量试验表明该消毒剂最低合格浓度为有效氯1 000 mg/L的稀释液.置25℃±2 ℃恒温恒湿箱3个月,该消毒剂有效氯含量平均下降8.68%.该消毒剂原液急性经口毒性试验属实际无毒,对小鼠骨髓嗜多染红细胞无致微核作用.结论 该消毒剂杀菌效果较好,毒性较低,性质不稳定.     

分子生物学方法鉴定由自毙鼠分离的细菌

目的 对1株由自毙鼠分离的细菌（X175菌株）进行属、种及型的鉴定。方法 ①采用16S rDNA对X175菌株进行种属鉴定;②应用荧光PCR检测X175菌株是否存在致泻性大肠埃希菌常见毒素基因（stx1/stx2/eae、lt/st、aggR/ipaH）及大肠埃希菌O104、H4基因;③应用PCR检测X175菌株是否存在肠出血性大肠埃希菌（EHEC）O104∶H4的9个毒力基因。结果 ①经16S rDNA鉴定,X175菌株与大肠埃希菌埃希菌属的一些菌株相似度达99%,进化树显示X175菌株与大肠埃希菌O104∶H4菌株的亲缘关系较近;②大肠埃希菌O104基因和ipaH基因检测结果均为阳性,stx1/stx2/eae、lt/st、aggR、志贺菌/沙门菌、H4等基因检测结果均为阴性;③肠出血性大肠埃希菌O104∶H4九个毒力因子检测结果均为阴性。结论 X175菌株为大肠埃希菌O104弱毒型菌株,H抗原和其他一些特性还需进一步研究。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.