蜂胶对环磷酰胺等4种诱发剂诱发突变的抑制作用

目的 探讨蜂胶对环磷酰胺等强诱变剂诱发基因突变的抑制作用。方法 应用Ames试验分别检测蜂胶对环磷酰胺（CP）、叠氮钠（NaN3)、正定霉素（DNR）、2－氨基芴（2－AF）诱发突变的抑制作用。结果 蜂胶对CP等4种诱变剂诱发的突变均产生抑制作用,且伴有剂－反应,;其中8－200μg／皿浓度蜂胶均出现中等强度或以下的抑制（抑制率＜75．0％,1000μg/皿浓度蜂胶对2－AF、NaN3、CP等3种诱变剂出现了强度抑制（抑制率分别为80．9％,79．7％,98．7％）。蜂胶本身无诱变活性。结论 蜂胶对CP等4种诱变剂诱发的不同类型的基因突变均有一定的抑制作用。     

玻璃酸钠中间体遗传毒性试验

目的研究玻璃酸钠中间体的遗传毒性。方法采用鼠伤寒沙门菌/哺乳动物微粒体酶试验(Ames试验)、微核试验、染色体畸变试验研究玻璃酸钠中间体的遗传毒性。结果 (1)Ames试验:在加与不加大鼠肝微粒体酶(S-9)条件下,玻璃酸钠中间体在0.8~500μg/皿剂量范围内,各菌株回变菌落数均未超过自发回变菌落数的2倍,亦无剂量-反应关系。受试物未引起TA97、TA98、TA100和TA102试验菌株基因突变,Ames试验阴性。(2)微核试验:玻璃酸钠中间体各剂量组(67、134、268mg/kg)所诱发的微核率分别为1.7‰、1.7‰和1.9‰,与阴性对照组(1.7‰)比较差异无显著性,说明在该试验条件下,该样品无致小鼠骨髓嗜多染红细胞微核作用,小鼠骨髓微核试验呈阴性。(3)中国仓鼠肺细胞染色体畸变试验:在加与不加S-9两种条件下,并于24 h后收集细胞进行染色体畸变分析,发现玻璃酸钠中间体各剂量组的染色体畸变率与阴性对照组相比差异无显著性。结论本试验条件下,玻璃酸钠中间体Ames试验结果为阴性,小鼠骨髓嗜多染红细胞微核试验结果为阴性,无细胞毒性作用,体外哺乳动物细胞染色体畸变试验结果为阴性。     

乙烷硒啉致突变试验研究

目的观察乙烷硒啉是否存在遗传毒性。方法应用Ames试验、中国仓鼠肺细胞体外培养染色体畸变试验和小鼠骨髓嗜多染红细胞微核试验,研究乙烷硒啉的致突变作用。结果Ames试验在〈400μg/皿浓度下未见回复突变菌落数显著增加;中国仓鼠肺细胞体外培养染色体畸变试验在〈3.3μg/ml浓度下未出现细胞染色体畸变率显著增高;小鼠骨髓嗜多染红细胞微核试验在〈20.0g/kg剂量下未诱发微核细胞率的增高。结论乙烷硒啉在试验剂量范围内无致突变作用。     

对二氯苯致突变性的实验研究

目的　研究对二氯苯的致突变性。方法　Ames试验用TA97、TA98、TA10 0和TA10 2菌株 ,加与不加S 9试验 (剂量设为 0 2 5、0 5、1 0、2 0、5 0mg/皿 ) ;小鼠骨髓多染红细胞微核试验 (剂量设为 10 0、2 0 0、40 0、80 0mg/kg)和小鼠睾丸细胞染色体畸变试验 (剂量设为 2 5 0、5 0 0、10 0 0mg/kg)。结果　Ames试验中各测试浓度的回变菌落数均未超过自然回变菌落数 2倍 ;小鼠骨髓多染红细胞微核试验和小鼠睾丸细胞染色体畸变试验 ,各剂量组和阴性对照组差异无显著性 (P >0 0 5 )。结论　该试验范围内 ,未见对二氯苯有致突变性。     

溴硝醇的致突变作用

目的研究常用化学添加抗菌剂溴硝醇的致突变性。方法通过CHL细胞染色体畸变试验、CHO细胞正向基因突变试验、Ames试验及小鼠骨髓微核试验等4个致突变生物学试验对溴硝醇进行致突变性研究。细胞染色体畸变试验,选用CHL细胞,设暴露浓度为30、10、5、2.5mg/L(-S9)和50、20、10、3mg/L(+S9)。正向基因突变试验,选用CHO细胞,设暴露浓度为20、10、5、2.5mg/L。Ames试验,选用TA97、TA98、TA100、TA102、TA1535菌株,暴露浓度为50、25、12.5、6.25、3.125μg/皿(+S9),30、15、7.5、3.75、1.875μg/皿(-S9)。小鼠骨髓微核试验,60只小鼠随机分成6组,雌雄各半,雄性小鼠染毒剂量为20、40、80mg/kg;雌性小鼠为25、50、100mg/kg。结果 CHL细胞染色体畸变试验结果显示,各剂量组溴硝醇诱发的染色体畸变率均≤4.5%,与阴性对照组比较差异无统计学意义(P0.05)。正向基因突变试验结果显示,各剂量组溴硝醇对CHO细胞突变频率,与阴性对照比较差异无统计学意义(P0.05)。Ames试验结果显示,各剂量组溴硝醇的回变菌落数均阴性对照组的自发回变菌落数的2倍,亦无剂量反应关系。小鼠骨髓微核试验结果显示,溴硝醇3个剂量组均未引起微核出现率增加。结论本研究条件下,溴硝醇无明显致突变作用。     

除草剂毒莠定原药的致突变性

目的　研究除草剂毒莠定原药的致突变性。方法　采用小鼠骨髓多染红细胞微核试验,剂量设为雄性13 1、2 61、5 2 2mg/kg、雌性2 3 0、460、92 0mg/kg ;小鼠睾丸精母细胞染色体畸变试验,剂量设为3 2 6、65 3、13 0 5mg/kg。Ames试验用TA97、TA98、TA10 0、TA10 2菌株,加与不加S9试验,剂量设为5、5 0、5 0 0、10 0 0、5 0 0 0 μg/皿。结果　小鼠骨髓多染红细胞微核试验和小鼠睾丸精母细胞染色体畸变试验,各剂量组和阴性对照组比较,差异无显著性(P >0 0 5 ) ;Ames试验中各测试浓度的回变菌落数均末超过自然回变菌落数的2倍。结论　该试验范围内,未见毒莠定原药有致突变性。     

杀菌剂十三吗啉的致突变性

目的研究杀菌剂十三吗啉原药的致突变性。方法小鼠骨髓多染红细胞微核试验剂量设为150、3006、00 mg/kg;小鼠睾丸精母细胞染色体畸变试验剂量设为163、326、652 mg/kg。Ames试验剂量设为5、50、500、1 000、5 000μg/皿。结果小鼠骨髓多染红细胞微核试验和小鼠睾丸精母细胞染色体畸变试验,各剂量组和阴性对照组比较,差异无显著意义(P>0.05);Ames试验中各测试浓度的回变菌落数均末超过自然回变菌落数的2倍。结论该试验范围内,未见十三吗啉原药有致突变性。     

新药轻灵-盐酸西部曲明的诱变性研究

目的为确保国家二类新药‘轻灵-盐酸西部曲明'临床用药的安全性,对其作出可靠的毒理学评价.方法采用Ames试验、体外染色体畸变分析试验和微核试验对其进行了体内外诱变性研究.Ames试验中,采用TA97、TA98、TA100、TA102四种菌株,平板掺入法,4个剂量进行了加与不加S9的试验;体外染色体畸变分析试验中,采用CHL细胞系,设4个剂量,进行加与不加S9的试验;在小鼠体内骨髓细胞微核试验中,采用80、27和9mg/kg剂量.结果Ames试验加与不加S9的试验均未发现回变菌落数增加;体外染色体畸变分析试验各剂量组的染色体畸变率均未超过5%;小鼠体内骨髓细胞微核试验未发现骨髓细胞微核率增加.结论在本试验条件下,未发现轻灵-盐酸西部曲明有诱变性.     

金神软胶囊的毒理学安全性研究

〔目的〕评价金神软胶囊作为有降脂功效的保健食品的食用安全性。〔方法〕采用急性毒性试验、小鼠骨髓微核试验、小鼠精子畸形试验、Ames试验和 3 0d喂养试验进行检测。〔结果〕雌、雄大、小鼠急性经口LD50 >10g/kg体重 ,属无毒级 ;小鼠骨髓微核试验、精子畸形试验和Ames试验结果均为阴性 ;3 0d喂养试验未显示明显毒性。〔结论〕金神软胶囊属安全的保健食品。     

蒲公英水煎剂抗突变作用实验分析研究

目的：根据体外原核细胞、体内真核细胞和体内生殖细胞染色体相结合的实验研究方法,对蒲公英水煎剂进行了抗突变作用的分析研究,为蒲公英保健功能开发作技术探讨。方法：采用标准化鼠伤寒沙门氏菌/微粒体酶试验(Ames Test)、小鼠骨髓细胞微核试验和小鼠睾丸染色体畸变试验方法,对不同浓度的蒲公英水煎剂进行了抗突变试验及效果评价。结果：蒲公英水煎剂各剂量组对阳性诱变剂敌克松(Dexon)、甲基甲烷磺酸酯(MMS)、2-乙酰氨基芴(2-AAF)所诱导的Ames试验菌株TA98、TA100的回复突变菌落数均有不同的拮抗作用。对环磷酰胺(CP)诱导的小鼠骨细胞微核发生率和对丝裂霉素C(MMC)诱发的小鼠睾丸细胞染色体的畸变均有明显的抑制作用。结论：提示蒲公英水煎剂具有一定的抗突变作用。     

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.     

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.     

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.     

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.