小鼠淋巴瘤细胞TK基因突变试验检测染料木素的诱变性

目的：用小鼠淋巴瘤细胞TK基因突变试验检测染料木素的诱变性。方法：不加S9活化的条件下，用染料木素5、10、15、20μg／ml处理L5178Y细胞3h，采用微孔板法进行细胞毒性、平板接种效率和突变频率测定。结果：随染毒剂量的增加，染料木素对L5178Y的细胞毒性增大。染料木素能诱发L5178Y细胞tk位点突变频率显著增高，当剂量达到15μg/ml以上时其诱发突变频率为自发突变的3倍以上。结论：染料木素对L5178Y细胞有明显的细胞毒性，并可诱发tk基因突变。     

基于TK基因突变试验评价卷烟烟气的遗传毒性

目的采用TK基因突变试验研究卷烟烟气的遗传毒性。方法以L5178Y tk+/-3. 7. 2C小鼠淋巴瘤细胞为研究对象,3R4F参比卷烟的烟气为受试物,卷烟烟气经DMSO萃取后,设置试验剂量组为20、40、80、100、150μg/m L,另设二甲基亚砜溶剂对照组和环磷酰胺阳性对照组,对L5178Y tk+/-3. 7. 2C小鼠淋巴瘤细胞染毒处理及表达。结果在加S9的情况下,80μg/m L的突变频率是溶剂对照组3倍以上,实验结果呈阳性。结论在此次试验条件下,卷烟烟气具有TK基因致突变作用。     

Fe3O4及Fe3O4-Glu纳米颗粒的毒性和致突变性研究

[目的]研究直径约15 nm的四氧化三铁纳米颗粒(nano-Fe3O4)、谷氨酸包覆的四氧化三铁纳米颗粒(nano-Fe3O4-Glu)的毒性及致突变性.[方法]①单次给药实验在以往急性毒性实验的基础上,对昆明种小鼠口服一次给药,分别得到nano-Fe3O4、nano-Fe3O4-Glu的最大耐受量.②小鼠骨髓细胞微核试验nano-Fe3O4及nano-Fe3O4-Glu分别设150mg/kg、300mg/kg和600mg/kg各三个剂量组,另设阴性对照组和环磷酰胺组,分别计算其微核率.③小鼠精子畸形试验两种受试物分别设150 mg/kg、300 mg/kg、600 mg/kg三个剂量组及阴性对照组和环磷酰胺组,连续5 d染毒,染毒后第35 d处死,分别计算其精子畸形率.④体外CHL细胞染色体畸变试验nano-Fe3O4设1.05μg/ml、2.10μg/ml、4.20μg/ml三个剂量组,nano-Fe3O4-Glu设30μg/ml、60 μg/ml、120 μg/ml三个剂量组,另设阴性、阳性对照组和空白对照组.在加S9mix和不加S9mix时,分别计算细胞染色体畸变率.[结果]两种受试物的小鼠经口染毒最大耐受量均大于600 mg/kg;小鼠骨髓细胞微核试验中两种受试物的微核率均低于2‰;小鼠精子畸形试验中,nano-Fe3O4各剂量组小鼠精子畸形率均高于3.8%,与阴性对照组比较有统计学差异(P＜0.01);体外CHL细胞染色体畸变试验中,在加与不加体外活化系统(S9mix)的条件下,两种受试物的CHL细胞染色体畸变率均低于5%.[结论]在本试验条件下,nano-Fe3O4及nano-Fe3O4-Glu对小鼠体细胞均未见有致突变性,而nano-Fe3O4对雄性小鼠生殖细胞有致突变性;在体外试验中,两种纳米颗粒均未见有致突变性.     

1，1-二氨基2，2-二硝基乙烯对哺乳动物细胞致突变性研究

在非代谢活化（-S9）和代谢活化（+S9）条件下，以1，1-二氨基-2，2-二硝基乙烯（FOX-7）处理小鼠淋巴瘤L5178Y细胞和中国仓鼠肺CHL细胞，进行体外哺乳动物细胞TK基因突变试验和染色体畸变试验。结果显示，分别以500、250、125 μg/ml浓度的FOX-7处理L5178Y细胞，各剂量组突变频率与溶剂对照组相比，差异有统计学意义（P<0.05），且具有剂量相关性；分别以300、200、100 μg/ml浓度FOX-7处理CHL细胞，各剂量组染色体畸变细胞率与溶剂对照组比较，差异无统计学意义（P>0.05）。提示FOX-7可能对小鼠淋巴瘤L5178Y细胞TK基因具有致突变性，对中国仓鼠肺CHL细胞染色体无致突变性。     

五氯酚钠致突变性研究

目的 研究五氯酚钠的致突变性,为五氯酚钠的毒性机制研究提供依据.方法 应用Ames试验、小鼠淋巴瘤细胞试验和体外染色体畸变试验研究五氯酚钠的致突变性.结果 五氯酚钠对鼠伤寒沙门菌TA97、TA98、TA100、TA102 4 株菌株无论直接作用或代谢活化后作用,均未呈现致突变性;随染毒浓度增大,L5178Y细胞tk位点的突变频率有升高的趋势,其中150 μg/ml剂量组的突变率与对照组比较,差异有统计学意义(P＜0.05);无论是否加入代谢活化剂,受试物均引起染色体畸变率的明显增加.结论 五氯酚钠能诱发中国仓鼠卵巢(CHO)细胞染色体畸变,是非基因致突变物或弱基因致突变物.     

硝基胍对小鼠L5178Y细胞TK基因的致突变作用

通过体外哺乳动物细胞TK基因突变试验,探讨硝基胍(NQ)的细胞致突变性。在无代谢活化(-S9)和有代谢活化(+S9)条件下,NQ处理L5178Y细胞3h后表达培养2d,加入三氟胸苷(TFT),接种于96孔板,培养12d,计算突变频率(MF)。结果显示,以1000、2 000、4000μg/ml NQ处理L5178Y细胞,在-S9和+S9条件下,各剂量组MF具有剂量相关性,4000μg/ml剂量组的MF分别为(126.24±20.22)×10-6和(375.83±41.94)×10-6,显著高于溶剂对照组(P<0.05)。提示NQ可能对小鼠淋巴瘤L5178Y细胞TK基因具有致突变性。     

三种化妆品原料遗传毒性的体外微核检测法

目的探讨三种化妆品原料(香兰素、尼泊金甲酯、对苯二胺)的遗传毒性。方法应用体外胞质分裂阻断微核法检测上述3种化妆品原料(香兰素:40、80、160μg/ml;尼泊金甲酯:63、125、250、500μg/ml;对苯二胺:15、30、60μg/ml)在加和不加代谢活化系统两种条件下对中国仓鼠肺细胞(CHL)微核率和细胞毒性的影响。设3个染毒剂量组、阳性对照组(+S9为环磷酰胺,-S9为丝裂霉素C)和溶剂对照组(二甲基亚砜)。结果三种化妆品原料的最高剂量均能引起50%～60%的细胞毒性;与溶剂对照组相比,香兰素各剂量组微核细胞率均无显著增加(P>0.05),尼泊金甲酯在加入代谢活化系统条件下各剂量组微核细胞率均有显著增加(P<0.01或P<0.05),对苯二胺在有和无代谢活化系统存在两种条件下微核细胞率均有显著增加(P<0.01)。结论体外微核试验显示,香兰素未检测出遗传毒性;尼泊金甲酯和对苯二胺具有遗传毒性,可导致CHL细胞染色体断裂或诱发非整倍体。     

复方菊苣粉急性经口毒性和遗传毒性研究

目的 研究复方菊苣粉的急性经口毒性和遗传毒性。方法 SD大鼠(体质量为170 g～190 g)20只，设15 g/(kg·bw)1个剂量组，进行急性经口毒性试验；小鼠骨髓嗜多染红细胞微核试验选用昆明种小鼠(体质量为25 g～30 g)50只，设2.5 g/(kg·bw)、5.0 g/(kg·bw)和10.0 g/(kg·bw)3个试验组，同时设阴性对照和阳性对照；体外哺乳类细胞染色体畸变试验：试验设11个复方菊苣粉剂量：-S9条件下设5.0 mg/ml、2.5 mg/ml和1.25 mg/ml 3个剂量；+S9条件下设2.18 mg/ml、1.09 mg/ml和0.55 mg/ml 3个剂量。同时设阴性对照，进行综合评价。结果 急性经口毒性试验：SD大鼠15 g/(kg·bw)剂量经口染毒后，2周内未见动物死亡，亦无明显的中毒症状或不良反应，判属无毒级别。遗传毒性试验：Ames试验、小鼠骨髓嗜多染红细胞微核试验和体外哺乳类细胞染色体畸变试验三项遗传毒性试验结果均为阴性。结论 复方菊苣粉属无毒级物质，未见遗传毒性作用。     

β-1，3-D-葡聚糖的遗传毒性研究

目的 检测β-1，3-D-葡聚糖的遗传毒性。方法 采用Ames试验、小鼠骨髓嗜多染红细胞微核试验和小鼠精子畸形试验对受试物进行遗传毒性研究。结果 β-1，3-D-葡聚糖Ames试验在加和不加S9条件下均无致突变性，对小鼠骨髓嗜多染红细胞微核试验无诱发微核作用，小鼠精子畸形试验未见精子畸形率增高。结论 β-1，3-D-葡聚糖在本实验条件下，无致突变作用。     

杨梅花青素的安全性评价研究

为评价杨梅花青素的食用安全性,依据《卫生部保健食品检验与评价技术规范》(2003)分别进行小鼠急性经口毒性试验、遗传毒性试验(Ames试验、小鼠骨髓细胞微核试验、小鼠睾丸染色体畸变试验)和大鼠30天喂养试验。结果显示,杨梅花青素对小鼠的急性经口半数致死剂量(LD50)分别为5 840和6 810 mg/kg,分别相当于人体推荐剂量的343和400倍。在加与不加S9,杨梅花青素染毒各剂量组对标准测试菌株TA97a、TA98、TA100和TA102均无致突变作用。各剂量杨梅花青素染毒组小鼠骨髓嗜多染红细胞微核率与阴性对照组相比,差异均无统计学意义(P0.05),PCE/NCE值在正常范围内。各剂量杨梅花青素染毒组小鼠的性染色体早熟分离率、常染色体早熟分离率和畸变细胞率与阴性对照组相比,差异均无统计学意义(P0.05)。在30天喂养试验中,大鼠的生长发育情况、血液学指标、血清生化指标、各主要脏器重量及其脏器系数以及病理组织学均未见异常变化。提示杨梅花青素急性经口毒性属于实际无毒级,无发育毒性、遗传毒性或致突变作用。在本次实验剂量范围内,杨梅花青素食用安全性良好。     

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.