登革Ⅱ型病毒感染Balb/C实验小鼠的研究

目的：探讨Balb/C小鼠作为实验动物模型感染登革病毒的情况。方法：小鼠腹部皮下多点注射接种大剂量登革病毒后在一定时间内检测血清病毒,抗体及腹腔巨噬细胞,脾细胞登革病毒感染情况。结果：Balb/C实验小鼠接种感染登革病毒以后能产生1-2d病毒血症,接种后第4d血清中即可检测到特异性抗体,说明在登革病毒感染早期即产生可检测到的特异性抗体,而腹腔巨噬细胞在接种后前1-2d登革病毒感染率较高,但下降很快,第4d以后感染水平很低,小鼠脾细胞登革病毒感染率极低,几乎检测不到阳性,结论：Balb/C实验小鼠可以用于实验感染登革Ⅱ型病毒。     

八氯代二苯并二噁英对C57BL/6j雄性小鼠心肌基因表达谱的影响

目的 探讨八氯代二苯并二噁英(1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin,OCDD)对小鼠心脏基因表达谱改变的影响.方法将20只7～8周龄SPF级雄性C57BL/6j小鼠按体重随机分为4组,分别为对照(玉米油)组和低(1.25×10(-6)g/ml)、中(1.25 × 10(-...     

二硫化碳染毒对ApoE基因敲除小鼠和C57BL/6J小鼠脂肪酸代谢的影响

目的 研究二硫化碳(CS2)染毒对ApoE基因敲除小鼠和C57BL/6J小鼠脂肪酸代谢的影响.方法 将24只雄性ApoE基因敲除小鼠随机分为CS2染毒正常饮食组、CS2未染毒正常饮食组、CS2染毒高脂饮食组、CS2未染毒高脂饮食组;24只C57BU6J雄性小鼠也按同样的方式分成4组;每组6只.将染毒组以浓度为1 g/m3的CS2进行静式吸入染毒,5 h/d,5 d/周,共2周.收集小鼠全血,采用酸催化甲酯化方法对脂肪酸进行衍生化,并用气质联用(GC-MS)方法比较染毒前后脂肪酸含量.结果 C57BL/6J小鼠染毒高脂饮食组花生酸含量明显低于C57BL/6J小鼠未染毒高脂饮食组,ApoE基因敲除小鼠染毒正常饮食组花生四烯酸含量明显低于ApoE基因敲除小鼠未染毒正常饮食组,ApoE基因敲除小鼠染毒高脂饮食组γ-亚麻酸含量明显高于ApoE基因敲除小鼠未染毒高脂饮食组,差异均有统计学意义(P＜0.05).结论 CS2染毒可以引起小鼠脂肪酸代谢紊乱,CS2可能对动脉粥样硬化等心血管疾病有影响.     

IRM-2、C57BL/6小鼠Lewis肺癌模型免疫学特性的比较研究

目的 观察IRM-2、C57BL/6小鼠肿瘤模型的免疫学特性。方法 取Lewis肺癌组织,用生理盐水稀释成2×106/ml,取细胞悬液,接种小鼠腋下,0.2ml/只,观察荷瘤鼠生存期、外周血白细胞分类及淋巴细胞分型,并与健康小鼠进行比较。结果 IRM-2荷瘤鼠的平均生存时间为25.5d,C57BL/6荷瘤鼠为24.5d,IRM-2荷瘤鼠CD4、CD8值低于IRM-2健康鼠。C57BL/6荷瘤鼠CD4、CD8值高于C57BL/6健康鼠,IRM-2小鼠的CD4/CD8比值小于1,C57BL/6比值大于1。两种荷瘤小鼠的CD11b均高于健康小鼠。结论 IRM-2小鼠CD4/CD8比值小于1,C57BL/6小鼠CD4/CD8比值大于1,IRM-2小鼠与C57BL/6小鼠免疫学功能有明显的差异。     

HBV阳性血清体外感染HepG-2细胞方法建立

目的建立乙型肝炎病毒(HBV)阳性血清体外感染人肝癌细胞系HepG-2的方法。方法低温同步化处理HepG-2细胞后用高浓度HBV阳性血清与含有4%聚乙二醇的无血清伊格尔极限必需培养基(MEM)共孵育HepG-2细胞,设阴性对照组和空白对照组;18 h后加入含10%胎牛血清的MEM继续培养6 d,每隔24 h收集细胞和培养上清,荧光定量PCR检测HBV DNA,间接免疫荧光技术检测细胞内乙型肝炎病毒表面抗原(HBsAg)。结果 HBV阳性血清感染组HepG-2细胞内和培养上清中在感染后第1 d可检测到HBV DNA,分别为(16.04±7.99)×103、(8.84±3.97)×103 copies/mL,细胞内DNA含量在第2 d达到(3.51±1.86)×105 copies/mL,然后逐渐下降,在第4 d降到检测下限以下,而培养上清中病毒DNA在检测的时间内逐渐升高,在第6天达到(8.41±5.34)×105 cop-ies/mL;间接免疫荧光检测感染组细胞膜和胞浆中均有HBsAg表达;传代培养感染细胞后,在第1代细胞培养上清和细胞内均可检测到HBV DNA(3.58×105、7.34×105 copies/mL),第2代培养上清中可检测到少量HBV DNA(2.89×103 copies/mL),但细胞内检测到HBV DNA低于检测下限(896 copies/mL),第3代细胞的上清和细胞内均未检测到HBV DNA。结论 HBV阳性血清在一定条件下可以感染HepG-2细胞,病毒能在细胞内进行短期复制。     

扎伊尔型埃博拉病毒实时荧光定量PCR方法的建立

目的 建立扎伊尔型埃博拉病毒实时荧光定量PCR快速检测技术。方法 人工合成扎伊尔型埃博拉病毒包膜糖蛋白GP基因上1 969～2 113 bp的保守特异片段,克隆到pUC57重组质粒中,构建阳性模板;以103～109拷贝数的重组质粒样品共7组作为标准品,制作标准曲线;设计上游引物5' - GAACCACATGATTGGACCAAGA - 3'、下游引物5' - TAACTCCAATACCTGCCGGTATC - 3'及TaqMan探针FAM 5' - TTGTTGATAAAACCCTTCCGGACCAGG - 3' BHQ1,采用普通PCR和实时荧光定量PCR,检测其特异性和灵敏度。结果 克隆出含GP 1 969～2 113 bp片段的阳性重组质粒pUC57 - GP,其浓度为97.75 ng/μl;以pUC57 - GP为标准品,制备标准曲线,拷贝数为103～109 copies/μL有较好线性关系,相关系数R2 = 0.999;能特异性检测扎伊尔型埃博拉病毒,而与I型登革病毒、寨卡病毒无交叉反应,其检测最低拷贝数达3.10×101copies/μl。 结论 建立了扎伊尔型埃博拉病毒荧光定量PCR快速检测技术,具有快速、灵敏、特异、定量检测等特点,可为埃博拉疫情的综合防控提供技术支撑。     

大剂量γ射线对小鼠造血功能损伤的比较研究

目的探讨大剂量电离辐射对IRM-2小鼠、C57BL/6 J小鼠造血功能损伤及恢复的比较。方法用137Csγ射线分别对IRM-2小鼠、ICR小鼠进行4.0Gy照射,照后9d,检测小鼠造血功能三项(脾指数、CFU-S、DNA)指标的变化;对IRM-2小鼠、C57BL/6 J小鼠进行6.0Gy照射,照后45d,检测小鼠外周血白细胞的变化及绝对值。结果 IRM-2小鼠4.0Gy照射后9 d造血功能三项指标均高于ICR小鼠,CFU-S、DNA差异有统计学意义(P0.001)。6.0Gy照射后45d WBC、RBC及HGB、HCT指标均高于C57BL/6 J小鼠,差异有统计学意义(P0.01)。结论受137Csγ射线大剂量及亚致死剂量照射后,IRM-2小鼠与C57BL/6 J小鼠及ICR小鼠比较,造血系统有较强的恢复功能。     

重组沙门菌载体HIV-1 2F5表位疫苗毒力及分布

目的 研究表达Ⅰ型人类免疫缺陷病毒(HIV-1)2F5表位的重组沙门菌(SA-2F5)对BALB/c小鼠的半数致死量(LD50),并观察其在小鼠体内的生物学分布.方法 BALB/c小鼠随机分8组,以0,104～1010菌落形成单位(CFU)重组菌灌胃,30d后用改良寇氏法测定LD50;BALB/c小鼠随机分2组,灌胃给予107CFU重组沙门菌或磷酸盐缓冲液(PBS),分别于感染后第3,9,16,30 d,无菌操作取各组肝、脾、肠系膜淋巴结,检测重组沙门菌在小鼠体内的分布.结果 SA-2F5对BALB/c小鼠的LD50为1.45×109CFU;感染后第3d,肝、脾、肠系膜淋巴结活菌数依次为5.38×104,4.87×104,9.08×103 CFU.第9d各脏器活菌数分别降至7.35×102,7.50×102及3.00 X 102CFU.第16d各脏器活菌数基本与第9d相当.之后各脏器中活菌数持续下降,至第30d肝、脾内检测不到活菌,肠系膜淋巴结内活菌为2.1×102CFU.结论 重组沙门菌SA-2F5毒力显著降低,在小鼠体内具有良好的生物学分布.     

唾液乙型肝炎病毒检测在预防乙型肝炎传播中的意义

目的 探讨乙型肝炎(简称乙肝)患者唾液中乙肝病毒(HBV)含量在乙肝传播中的意义.方法 采用荧光定量聚合酶链反应检测200例乙肝患者和20例健康体检者的血清、唾液中HBVDNA含量.按血清乙肝病毒含量高低分为4组,即对照A组、阴性B组、低病毒C组[1×103～1×105拷贝/ml(copies/ml)]、高病毒D组(＞1×105copies/ml).分析唾液与血清病毒含量之间的关系.结果 200例乙肝患者血清中检出HBV DNA 180例,阳性率为90.O%,而唾液中检出HBV DNA145例,阳性率为72.5%,两者比较差异没有统计学意义(X2=1.35,P＞0.05).低病毒C组血清与唾液检出病毒(100.0%vB 38.5%)两者比较差异具有统计学意义(X2=14.11,P＜0.01).高病毒D组血清与唾液检出病毒(100.%It8 83.8%)两者比较差异没有统计学意义(X2=1.05,P＞0.05).血清高病毒D组病毒平均含量为(6.63±1.55)log copies/ml(拷贝/ml的常用对数),唾液中病毒平均含量为(5.21±1.85)log copies/ml,唾液较血清病毒含量平均低一个数量级.20例健康体检者血清和唾液中未检出HBV DNA.结论 乙肝患者血清中含有较高的HBV DNA病毒时,其唾液中也存在具有感染性的HBV DNA病毒,可能成为传染源之一.精确检测唾液中HBV DNA水平可评价病毒在体内复制程度,进而判断患者的传染力度.     

伯氏疟原虫感染不同年龄小鼠免疫反应特点

目的 了解伯氏疟原虫(Plasmodium berghei NK65,P.b NK65)感染幼年和中年C57BL/6小鼠免疫反应特点.方法 P.b NK65感染3周龄幼年和8月龄中年C57 BL/6小鼠,采用流式细胞分析技术检测不同年龄组小鼠脾细胞悬液中髓样树突状细胞(dendritic cells,DCs)数量,表面表达MHCⅡ类分子和CD86分子的DCs数量以及分泌IgG抗体的B细胞数量;ELISA方法检测脾细胞培养上清中IFN-γ和IL-4水平.结果 3周小鼠DCs数量[(40.08 ±3.54)×105]在感染后5d明显升高,8月龄鼠在感染后5 d[(103.47 ±11.07) ×105]及8 d[(104.04±1.92) ×105]明显升高;3周鼠表面表达MHCⅡ类分子和CD86分子的DCs数量在感染后明显升高,8月龄鼠在感染后8d表达MHCⅡ类分子[(239.40±16.32)×105]和CD86分子[(148.48±14.84)×1o5]数量明显高于3周鼠(P ＜0.05);3周鼠[(251.01 ±34.02) pg/mL]和8月龄鼠[(584.17±54.03) pg/mL] IFN-γ水平在感染后5 d均明显升高,2组比较差异有统计学意义(P＜0.05).结论 3周和8月龄C57BL/6小鼠感染P.b NK65后,其细胞免疫和体液免疫存在明显差异.     

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.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.