松花粉对小鼠急性酒精性肝损伤的保护作用研究

目的:研究松花粉对小鼠急性酒精性肝损伤的保护作用。方法:通过预先给予各组小鼠松花粉,剂量分别为500、1000mg/kg,30d后各剂量组及模型对照组小鼠经口一次给予乙醇4800mg/kg,建立急性肝损伤模型,观察松花粉对急性肝损伤小鼠肝脏脂质过氧化反应、肝细胞脂肪变性等的影响。结果:12h后各剂量组小鼠肝组织MDA含量与乙醇模型组相比均降低,高剂量组具有显著差异(P<0.05);低、高剂量组肝组织GSH含量均高于乙醇模型对照组,分别具有显著和极显著差异(P<0.05,P<0.01)。肝组织苏丹Ⅲ染色显示,各剂量组肝细胞内脂滴比乙醇模型对照组明显减少。结论:实验结果表明松花粉能对抗酒精中毒引起的肝脏脂质过氧化损伤,具有有效的保肝作用。     

三羟异黄酮保护急性酒精性肝损伤机制研究

目的探讨大豆三羟异黄酮(Gen)对急性酒精性肝损伤保护效果及与乙醇代谢相关酶活性的影响关系。方法 2 w龄昆明种小白鼠(90只)随机分为空白对照组,模型组,Gen试剂对照组(200 mg/kg bw),Gen试剂预防组(分别有50、100、200 mg/kg bw的低、中、高三种剂量,乙醇灌胃前给药)和Gen试剂治疗组(低、中、高三种剂量,乙醇灌胃后给药)9组;用50%乙醇12 ml/kg bw大剂量灌胃雄性小鼠诱发急性酒精性肝损伤,实验连续10 d后测定小鼠血液和肝脏组织的丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、丙二醛(MDA)、甘油三酯(TG)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)等生化指标,测定肝脏组织的乙醇脱氢酶(ADH)、乙醛脱氢酶(ALDH)和细胞色素氧化酶系(CYP2E1)的活性。结果模型组小鼠血液与肝脏的ALT、AST水平比较空白对照组和Gen试剂对照组明显升高,差异显著(P<0.05=;Gen预防组与治疗组小鼠血液与肝脏的ALT、AST水平比较模型组显著降低,显示有剂量效应,MDA、TG比较模型组显著降低,GSH、SOD比较模型组显著升高,差异显著(P<0.05);Gen预防组与治疗组小鼠血液与肝脏的ADH、ALDH与模型组比较酶活性显著升高,CYP2E1酶活性显著降低;Gen对照组与空白对照组之间各项检测结果无显著差异。结论 Gen对急性酒精性肝损伤有预防保护效果,有影响乙醇代谢酶活性作用,缓解乙醇代谢产生的氧化应激。     

二烯丙基一硫化物对小鼠急性酒精性肝损伤的保护作用

目的研究二烯丙基一硫化物(DAS)对急性酒精性肝损伤的保护作用。方法将40只健康SPF级雄性昆明小鼠随机分为4组,分别为对照组、模型组、DAS干预组和DAS对照组,每组10只。DAS干预组和DAS对照组小鼠经口灌胃给予50 mg/kg的DAS溶液,每天1次,连续7 d;对照组和模型组小鼠给予等体积的玉米油。末次给药2 h后,模型组和DAS干预组小鼠经口灌胃给予5 g/kg乙醇诱导肝损伤,连续3次,每次间隔12 h;对照组和DAS对照组小鼠给予等体积等热量的麦芽糖糊精。测定血清丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)的活力以及肝组织匀浆中谷胱甘肽(GSH)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPx)活力。结果与模型组比较,对照组、DAS干预组和DAS对照组小鼠血清ALT、AST活力和肝组织匀浆中MDA含量均较低,肝组织匀浆中GSH含量和SOD、GPx、GR活力均较高,差异有统计学意义(P<0.05或P<0.01)。结论 DAS对小鼠急性酒精性肝损伤有保护作用,机制可能与其具有的抗氧化活性有关。     

姜精油对小鼠急性酒精性肝损伤的辅助保护作用

目的研究姜精油对小鼠急性酒精性肝损伤是否具有辅助保护作用。方法将70只BALB/C小鼠随机分为空白对照组,急性酒精性肝损伤模型组,姜精油超低剂量组(62.5mg/kg)、极低剂量组(125mg/kg)、低剂量组(250mg/kg)、中剂量组(500mg/kg)和高剂量组(1000mg/kg)7组,每组10只。常规喂养,每日灌胃给药1次,连续给药30天,第31天采用50%无水乙醇溶液进行一次性灌胃后断头处死。检测各组小鼠肝匀浆中的甘油三酯(TG)、丙二醛(MDA)和谷胱甘肽(GSH)水平,并进行肝脏病理组织学检查。结果随姜精油剂量的增加,小鼠肝组织匀浆的中TG值呈下降趋势,其中中剂量组和高剂量组与急性酒精性肝损伤模型组间存在显著差异(P<0.05);各剂量组的MDA值均明显低于急性酒精性肝损伤模型组(P<0.01),其中低剂量组的MDA值最低;极低剂量组和低剂量组的GSH值明显高于急性酒精性肝损伤模型组(P<0.05,P<0.01);低剂量组、中剂量组和高剂量组的肝脏病理组织检查评分明显低于急性酒精性肝损伤模型组(P<0.01)。结论姜精油对酒精性肝损伤具有辅助保护作用。     

N—乙酰半胱氨酸对二甲基甲酰胺所致急性肝损伤的保护作用

目的 探讨N-乙酰半胱氨酸(NAC)对二甲基甲酰胺(DMF)所致急性肝损害的保护作用。方法 给小鼠腹腔注射一次1800mg/kg DMF后用NAC灌胃。测定血清山梨醇脱氢酶(SDH)、丙氨酰氨基转移酶(ALT)、甘胆酸(CG)、肝脏谷胱甘肽(GSH)、Na~ K~ -ATP酶、Ca~(2 )-ATP酶,观察肝脏病理改变。结果 与单纯染毒组比较,染毒后连续口服NAC组血清SDH、ALT、CG明显降低(P<0.05),肝脏GSH含量升高,Na~ K~ -ATP酶、Ca~(2 )-ATP酶活性增高(P<0.05),肝脏病理改变减轻。结论 NAC对DMF所致急性肝损伤有一定保护作用。     

急、慢性酒精暴露对小鼠肝损伤的作用

目的探讨不同方式酒精暴露致小鼠肝损伤作用。方法选择32只6周龄SPF级C57BL/6J雄性小鼠,适应性喂养1周后,随机分配到急性酒精处理组和慢性酒精处理组,每组16只;在每个组别中,再随机分成对照组(n=8)和酒精组(n=8)。将C57BL/6J小鼠分别通过单次给予50%(V/V)乙醇溶液(4 g/kg体重)灌胃和喂养LIEBER-DECARLI酒精液体饲料6周建立急性和慢性酒精性肝损伤模型。取血清检测生化指标丙氨酸氨基转移酶(ALT)及血脂水平,取肝脏并称重,计算肝脏指数。采用苏木精伊红(HE)染色观察病理改变、肝组织匀浆后检测丙二醛(MDA)和还原型谷胱甘肽(GSH)水平。结果与各自对照组相比,两酒精组小鼠肝脏指数均有增加,且慢性酒精组(5.47±0.08)差异有统计学意义(P=0.032);两酒精组小鼠血清ALT和甘油三酯水平均显著增加,其中慢性酒精组ALT[(69.6±0.10)mmol/L]增加更为明显(P=0.009);HE染色结果显示两酒精组小鼠肝组织均有受损,其中慢性酒精组小鼠肝损伤组织学、脂肪变性及炎症坏死程度较急性组均表现更严重;两酒精组小鼠肝脏MDA含量均有升高,且慢性组[(0.55±0.02)mmol/L]表现更为明显(P=0.014),GSH含量均低于各自对照组,差异均有统计学意义(P=0.038、0.028)。结论两种方法建立的酒精性模型均可造成小鼠肝损伤,其中液体酒精饲料诱发的小鼠慢性肝脏损伤更为严重。     

大豆卵磷脂对酒精性肝损伤保护作用效果观察

[目的]研究大豆卵磷脂对小鼠酒精性肝损伤的保护作用。[方法]将动物随机分成阴性对照组、乙醇模型组及0.2、0.4和1.2 g/(kg.bw)3个剂量组,剂量组每天灌胃给予大豆卵磷脂。30 d后,乙醇模型组及剂量组1次灌胃给予50%乙醇12 ml/kg.bw,禁食12 h后处死,取动物肝脏,测定肝匀浆液MDA、GSH-PX、TG量,对肝脏进行病理组织学检查。[结果]与乙醇模型组比较,低、高剂量组MDA含量降低,各剂量组GSH-PX含量升高,组织切片观察到脂肪变性评分低于乙醇模型组,差异均有显著性。[结论]大豆卵磷脂对酒精性肝损伤具有保护作用。     

蝙蝠蛾拟青霉复合胶囊对四氯化碳与酒精所致小鼠急性肝损伤保护作用

目的探讨蝙蝠蛾拟青霉复合胶囊对四氯化碳与酒精所致小鼠急性肝损伤的保护作用。方法分别采用四氯化碳和酒精灌胃诱导小鼠急性肝损伤模型,测定四氯化碳急性肝损伤模型小鼠血清中丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)的含量及酒精急性肝损伤模型小鼠肝组织中丙二醛(MDA)、甘油三酯(TG)、还原型谷胱甘肽(GSH)的含量并观察2组肝组织切片病理形态学变化。结果蝙蝠蛾拟青霉复合胶囊675、2 025 mg/kg BW剂量组四氯化碳急性肝损伤小鼠血清的ALT、AST含量均低于模型对照组,差异具有统计学意义(P 0.05)。急性酒精性肝损伤模型中,675、2 025 mg/kg BW剂量组的MDA含量和3个剂量组的TG含量明显低于模型对照组,675、2 025 mg/kg BW剂量组的GSH含量明显高于模型对照组,差异均具有显著性(P 0.05)。小鼠肝组织形态学结果表明,四氯化碳肝损伤模型肝组织中、高剂量组的肝脏细胞坏死程度与模型对照组比较积分显著下降,差异具有显著性(P 0.05),各剂量组气球样变积分和高剂量组水样变程度积分也较模型组有显著性降低(P 0.01);蝙蝠蛾拟青霉复合胶囊能显著改善急性酒精性肝损伤小鼠肝细胞脂肪变性程度,差异具有显著性(P 0.05)。结论蝙蝠蛾拟青霉复合胶囊对小鼠急性肝损伤具有较好的辅助保护功能。     

茶多酚、维生素C对镉急性毒性影响的实验研究

目的 研究预先投予茶多酚(TP)和Vit C对急性镉(Cd)毒性的影响。方法 4组Wistar大鼠分别皮下注射氯化钠、25μmol/kg的氯化镉溶液,以及以TP、VitC预处理后的25μmol/kg氯化镉溶液。染毒24h后测定其血清中的ALT和IDH含量,肝和肾皮质的Cd含量,肝、肾组织中的GSH和MDA含量及GSH-Px活性。结果 与对照组比较,单纯染镉组大鼠肝、肾Cd含量升高,肝GSH、MDA含量升高,GSH-Px入活性降低,而肾GSH—Px活性降低。经TP和Vit C预处理后,急性染镉大鼠血清中的ALT和IDH活性及肝脏中GSH、MDA含量明显低于单纯染镉组,而GSH-Px活性高于单纯染镉组。TP干预组肝脏中的Cd及肾脏中MDA显著低于单纯染镉组,Vil C干预组末见差异。与单纯染镉组比较,TP和VitC干预组肾脏中的Cd、GSLH含量及GSH-Px活性差异无显著性。结论 TP和VitC预处理对急性镉中毒所致的肝损伤有一定的预防作用。     

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.