氟化钠,氯化汞和亚砷酸钠对小鼠睾丸早期精细胞微核率的影响

采用Ｔａｔｅｓ微核试验法检测３种无机化学物对雄性小鼠生殖细胞染色体的损伤作用。不同剂量的氟化钠（１４ｍｇ／ｋｇ、２８ｍｇ／ｋｇ）、氯化汞（０．５ｍｇ／ｋｇ、１．０ｍｇ／ｋｇ）和亚砷酸钠（０．２５ｍｇ／ｋｇ、０．５ｍｇ／ｋｇ）分别经腹腔注射染毒，每天１次，连续３天，于首次染毒后第１５天杀鼠。测得微核率为７．２％，１０．０‰；６．４‰、５．６‰和３．４‰、３．０‰。其中氟化钠和氯化汞组的微核率与阴性对照组（２．２‰）比较．有显著差异．可以认为是雄性生殖细胞染色体断裂剂。根据染毒到制片的间隔时间判断，氟化钠和氯化主要作用于减数分裂前的Ｇ１和Ｓ期初级精母细胞。     

一种有机镓化合物对小鼠的胚胎毒性和致畸性

本文报道２－二甲氨基环己氧基－二甲基镓的胚胎毒性和致畸性的试验结果。雌性小鼠在检出阴栓的当天定为妊娠ｄ０，于ｄ０～ｄ１５每天灌胃一次，剂量分１．５，３，６ｍｇ／ｋｇ三组，对照组给生理盐水，ｄ１７处死小鼠剖腹按常规方法检查胚胎毒性和致畸性。结果表明６ｍｇ／ｋｇ组２只母鼠中毒死亡，各染毒组母鼠体重增长迟缓。３和６ｍｇ／ｋｇ组出现明显胚胎毒性，早期吸收胎明显增加。染毒组活存胎鼠中均有外观、骨骼和内脏畸形可见。     

钼和汞联合染毒对小鼠骨髓多染红细胞微核率影响

［目的］探讨对钼对汞遗传毒性的影响。［方法］观察采用腹腔注射钼酸钠和氯化汞联合染毒对小鼠骨髓多染红细胞微核率的影响。［结果］连续４天给小鼠注射ＨｇＣｌ２［１．０ｍｇ／ｋｇ（ｂｗ）］的同时注射１０、１００ｍｇ／ｋｇ（ｂｗ）］的Ｎａ２ＭｏＯ４可显著降低ＨｇＣｌ２的致小鼠微核率（Ｐ〈０．００１）;在ＨｇＣｌ２［１．０ｍｇ／ｋｇ（ｂｗ）给小鼠染毒前３天连续注射１００ｍｇ／ｋｇ（ｂｗ）Ｎａ２ＭｏＯ４可显著地     

硒和锗拮抗苯致小鼠骨髓细胞微核的实验观察

采用小鼠骨髓嗜多染红细胞微核试验方法观察微量元素硒和锗的抗苯诱变活性。结果：苯吸入染毒（１５ｍｇ／Ｌ×５天，每天２小时）后，小鼠微核率明显增高。在苯处理前３０分钟经口给予不同浓度的亚硒酸钠（００５～２５０ｍｇ／ｋｇ）或锗－１３２（５０～５００ｍｇ／ｋｇ），微核细胞率显著降低，微核抑制率随硒或锗剂量的增加而升高。提示，硒和锗对苯诱导的遗传物质损伤具有保护作用     

氯化镉对小鼠精子的影响

４０只小鼠随机分为４组：对照组，氯化镉３．５ｍｇ／ｋｇ，氯化镉７．０ｍｇ／ｋｇ，氯化镉１４．０ｍｇ／ｋｇ。灌胃染毒，灌胃量为０．１ｍｌ／１０ｇ体重。３天后处死动物，检测精子活动率及精子密度。结果表明，氯化镉７．０ｍｇ／ｋｇ和氯化镉１４．０ｍｇ／ｋｇ组精子活动率比对照组降低（Ｐ〈０．０５），氯化镉７．０ｍｇ／ｋｇ和氯化镉１４．０ｍｇ／ｋｇ组精子密度比对照组降低有非常显著意义（Ｐ〈０．０１）。     

抗氟灵致突变实验研究

用健康昆明种小鼠，以１１．８和２．４ｇ／（ｋｇ．ｄ）抗氟灵连续灌胃５次，每次间隔２４小时，分别用０．０４ｇ／（ｋｇ．ｄ）环磷酰酰和０．００２ｇ／（ｋｇ．ｄ）丝裂霉素Ｃ为阳性对照，１ｍｌ／（ｋｇ．ｄ）蒸馏水为阴性对照进行微核和精原及精母细胞染色体畸变试验，结果实验组小鼠骨髓嗜多染色红细胞微核发生率明显低于阳性对照组（Ｐ〈０．０１），高于阴性对照组（Ｐ〉０．０５），睾丸精原与精母细胞染色体畸变率比阳性     

氯化锂对小鼠体细胞遗传毒性作用的实验研究

观察氯化锂的遗传毒性特征并对其毒作用机制做一初步探讨。以氯化锂为受试物,昆明种小鼠为受试对象,分低（２２．５ｍｇ／ｋｇ）、中（７５．０ｍｇ／ｋｇ）、高（２２５．０ｍｇ／ｋｇ）３个不同剂量组进行小鼠体细胞遗传毒性试验。氯化锂经口灌胃染毒后,小鼠骨髓细胞染色体畸变率增高（Ｐ〈０．０５）;骨髓细胞微核率、胎肝细胞微核率增高（Ｐ〈０．０５,Ｐ〈０．０１）。结果表明,一定剂量的氯化锂对昆明种小鼠体细胞具有遗     

茶黄色素的毒理学研究

对茶叶提取物茶黄色素的急性毒性、蓄积毒性和致突变作用进行了研究。结果表明：茶黄色素属基本无毒类；无明显蓄积作用；但大鼠和小鼠经口染毒均可见明显中枢神经系统中毒症状和肺弥漫性出血灶；茶黄色素３７５、７５０、１５００ｍｇ／ｋｇ剂量组小鼠骨髓ＰＣＥ微核率分别为２．０‰，２．８‰．２．４‰，与阴性对照组（２．８‰）相比均无显著性差异；Ａｍｅｓ实验中３１２．５μｇ、６２５μｇ、１２５０μｇ、２５００μｇ５０００μｇ／皿各剂量组ＴＡ９７、ＴＡ９８、ＴＡ１００、ＴＡ１０２等不同菌株加与不加Ｓ９ＭＲ均小于２；茶黄色素３７５、７５０１５００ｍｇ／ｋｇ各剂量组小鼠睾丸级精母细胞染色体畸变率与对照组比较无明显差异，而１５００ｍｇ／ｋｇ剂量组小鼠睾丸初级精母细胞性染色体单价体（４．８％）和常染色体单价体（５．６％）与对照组（２．５％，２．５％）比较有显著差异。     

镉对大鼠肺泡巨噬细胞Fc受体和超微结构影响的研究

雌性ＳＤ大鼠经气管注入ＣｄＣｌ２溶液染毒后２４ｈ，观察肺泡巨噬细胞（ＡＭ）Ｆｃ受体（ＦｃＲ）数的改变和超微结构的变化。结果表明，Ｃｄ对ＡＭＦｃＲ数的影响表现出一定的剂量效应关系。０．０２ｍｇ／ｋｇ时ＦｃＲ数即显著降低，０．１、０．５ｍｇ／ｋｇ染毒剂量组的ＦｃＲ数分别比对照组降低７２％和８８％。ＡＭ超微结构观察发现，暴露于Ｃｄ后，大鼠的ＡＭ线粒体（Ｍｉ）膜性结构明显受损，膜破损、嵴变淡、溶解，甚至空泡化。溶酶体的变化也比较显著。作者认为，Ｃｄ引起大鼠ＡＭ胞质变化比胞核的变化明显。     

2－萘酚对小鼠免疫功能影响的实验研究

研究了２－萘酚对ＢＡＬＢ／Ｃ小鼠免疫功能的影响。结果发现，当小鼠接触５～２０ｍｇ／ｋｇ剂量２－萘酚时，１０ｍｇ／ｋｇ和２０ｍｇ／ｋｇ剂量组的小鼠抗体生成细胞功能和外周血Ｔ淋巴细胞数明显低于对照组（Ｐ＜０．０５），并２０ｍｇ／ｋｇ剂量组的脾重也显著低于对照组（Ｐ＜０．０５）。但是，各剂量组小鼠外周血红细胞和白细胞数、体重及主要脏器病理检查均未见异常改变。可见，２－萘酚对机体免疫功能有一定的抑制作用。     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.     

Psychopathological features of a patient population of targets of workplace bullying

BACKGROUND: A strong association between workplace bullying and subsequent anxiety and depression, indicated by empirical research, suggests that bullying is an aetiological factor for mental health problems. AIMS: To evaluate levels of stress and anxiety-depression disorder developed by targets of workplace bullying together with outcome at 12 months and to characterize this population in terms of psychopathology and sociodemographic features. METHODS: Forty-eight patients (36 women and 12 men) meeting Leymann Inventory of Psychological Terror criteria for bullying were included in a prospective study. Evaluations were performed at first consultation and at 12 months using a standard clinical interview, a visual analogue scale of stress, the Hospital Anxiety and Depression (HAD) scale, the Beech scale of stress in the workplace and a projective test (Picture-Frustration Study). RESULTS: At first consultation, 81% of patients showed high levels of perceived stress at work and 83 and 52% presented with anxiety or depression, respectively. At 12 months, only 19% of working patients expressed a feeling of stress at work. There was a significant change in symptoms of anxiety while there was no change in symptoms of depression. Stress at work and depression influenced significatively capacity to go back to work. At 12-month assessments, workers showed a significantly better score on the HAD scale than non-workers. Over half the targets presented a neuroticism-related predominant personality trait. CONCLUSION: Workplace bullying can have severe mental health repercussions, triggering serious and persistent underlying disorders.     

The rise and fall in incidence of malignant mesothelioma from a British Naval Dockyard, 1979-1999

BACKGROUND: The incidence of malignant mesothelioma in Britain is predicted to rise over the next 15-25 years because of past failure to protect the workforce against inhalation of asbestos. In British Naval dockyards, alternative insulation materials and respiratory protection were introduced from the mid-1960s. Aims This study was carried out to investigate the effects of these control measures on mesothelioma deaths in dockyard workers. METHODS: Cases of mesothelioma of the pleura and peritoneum between 1979 and 1999 in workers from the Devonport Naval Dockyard, south-west England, were sought from coroners' and medico-legal records. RESULTS: Three hundred and one cases were identified, 7% peritoneal. The peak incidence occurred in 1991 with 25 cases per annum (quadratic model fit R(2) = 74.2%, P < 0.001) and we predict that by 2003 the incidence will fall to fewer than five cases per annum. The mean time between first exposure and presentation was 48.5 years [95% confidence interval (CI) = 47.3-49.8], but this was significantly shorter in the more heavily exposed trades, when compared with the less heavily exposed (42 years, 95% CI = 39.0-45.0, versus 49.5 years, 95% CI = 48.2-50.9). Those with higher exposure were also at significantly greater risk of peritoneal disease (P < 0.023, Fisher's exact test). CONCLUSION: The reduction in incidence of mesothelioma is greater than can be accounted for by reduction in numbers of dockyard workers over the last 50 years. Changes in insulation materials and improved industrial hygiene measures introduced into the Devonport Dockyard from the mid-1960s have resulted in an earlier decline in the incidence of malignant mesothelioma than that predicted for the British workforce as a whole.     

Organophosphate toxicity and occupational exposure

The ubiquitous organophosphates present a continuing health hazard in agriculture, public health eradication programmes and as chemical warfare agents. Despite significant progress in understanding the potential mechanisms of toxicity far beyond the commonly accepted mechanism of cholinesterase inhibition in intentional exposures, the precise health effects following occupational exposures are yet to be completely defined. A much greater understanding exists of the clinical features of organophosphate poisoning. These are characterized by a triphasic response involving an initial acute cholinergic phase, an intermediate syndrome (both associated with high mortality) and a disabling but non-lethal delayed polyneuropathy. The delayed polyneuropathy may occur in the absence of the cholinergic or intermediate phases. However, progress is still required in order to improve the quantification and assessment of occupational exposures and the implementation of appropriate preventive measures. Finally, evidence-based guidelines for appropriate or optimal therapeutic interventions following poisoning are required urgently and collaborative work with colleagues in developing countries, where the occurrence of organophosphate exposures is more frequent, may provide the answers.     

Miliaria rubra of the lower limbs in underground miners

This report documents a case series of miliaria rubra of the lower limbs in miners at a deep underground metalliferous mine in tropical arid Australia. During the summer months of February and March 1999, all cases of miliaria rubra of the lower limbs in underground miners seen at the mine's medical centre were clinically examined and administered a questionnaire. Twenty-five patients were seen, an incidence of 56.4 cases per million man-hours. Miliaria rubra was most often located between the ankle and knee (88% of cases). Twenty-four percent had concurrent folliculitis and 20% had concurrent tinea. Thirty-two percent had a personal history of asthma. Walking through ground-water and splashing of the legs was common. Three to 4 weeks of sedentary duties in air conditioning was generally required to achieve resolution of miliaria rubra. The incidence of miliaria rubra of the lower limbs is 38% of the incidence of heat exhaustion at the same mine. The length of disablement is greater, however. Atopics may be at increased risk of miliaria rubra. Control measures are discussed.     

Planning research

The starting point for any research project should be a question.Once this has been defined and the relevant scientific literaturereviewed, a protocol should be drawn up. This will be used notonly as a guide to the conduct of the study and in the preparationof the final report, but also in seeking any financial supportand approvals that are required for the investigation. A protocolis normally arranged in sections covering the background tothe study, the question(s) that it will address, the methodsthat will be used for the collection and analysis of data, thestatistical power of the investigation (where relevant), anyethical considerations, and the financial input that will beneeded. A pilot study is often helpful where aspects of thestudy method are untried or of uncertainvalidity.     

Stress in the Norwegian police service

BACKGROUND: High levels of stress have been attributed to the conditions of police work, but there is little empirical evidence for this. AIMS: To develop a new instrument to measure job stress in the police; to assess the most severe and frequent police stressors; to compare levels of stress according to the demographic and organizational factors; and to study stress in relation to personality traits, work locus of control and coping strategies. METHODS: A comprehensive nationwide questionnaire survey of 3272 Norwegian police at all hierarchical levels, including the Norwegian Police Stress Survey (NPSS), the Job Stress Survey, the Basic Character Inventory, the Work Locus of Control Scale, and the Coping Strategies Scale. RESULTS: Work injuries were appraised as the most stressful but least frequent stressor and job pressure was reported the least severe but most frequent stressor. Females experienced job stressors less frequently, but appraised them as more severe than men did. Older police officers reported more job pressure severity and fewer work injuries. The police in districts where peer support was planned but not implemented, and who worked in districts with more than 50,000 inhabitants, perceived the lack of support more severely than others. The correlations between stress and personality traits, work locus of control, and coping were moderate. CONCLUSIONS: The NPSS captures police-specific stressors that are not adequately measured by global stress instruments. The study of stress in police work should preferably involve a nationwide use of police-specific stress instruments.