过氧化苯甲酰对小鼠肝脏组织损伤作用

目的 探讨面粉增白剂过氧化苯甲酰(benzoyl peroxide,BPO)对小鼠肝脏组织的损伤作用.方法 64只昆明种小鼠随机分为对照组和低、中、高剂量BPO组,分别灌胃给予BPO50,100和200 mg/kg,每组16只,雌雄各半;灌胃6周后,测定各组肝脏组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量及三磷酸腺苷(ATP)酶活力.结果 高、中剂量BPO组SOD活力分别为(40.15±7.13),(46.01±6.69)U/(mg·prot),与对照组(53.15±6.55)U/(mg·prot)比较,差异有统计学意义(P<0.05);高剂量BPO组与对照组MDA含量分别为(1.93±0.37)和(1.57±0.33)nmol/(mg·prot),差异有统计学意义(P<0.05);高剂量BPO组Mg2+-ATP、Ca2+-ATP酶活力分别为(1.58±0.11)和(1.48±0.09)μmol Pi/(mg·prot),与对照组比较明显降低,差异有统计学意义(P<0.05);各剂量BPO组GSH-Px活力与对照组比较差异无统计学意义(P>0.05).结论 BPO在一定程度上可降低小鼠肝脏抗氧化及Ca2+、Mg2+-ATP酶活力.     

山茱萸多糖对高温暴露大鼠睾丸组织损伤影响

目的 观察山茱萸多糖(FCP)对高温暴露大鼠睾丸组织损伤的影响.方法 用FCP(0,10,50,100,150mg/kg)灌胃雄性SD大鼠14 d后温水浴造模,观察睾丸组织形态改变,测定睾丸及附睾系数、精子计数与活力、超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量及生殖细胞凋亡情况.结果 FCP可改善损伤睾丸组织形态,随浓度增加作用越明显;与损伤组SOD活力(195.05±25.62)NU/mg prot及MDA含量(3.02±1.18)nmol/mg prot比较,FCP150 mg组SOD活力(285.34±24.37)NU/mg prot明显升高,MDA含量(1.48±0.63)nmol/mg prot明显降低;与损伤组(64.05±1.35)%比较,FCP150mg组生殖细胞凋亡率(15.50±1.06)%明显下降,差异有统计学意义(P<0.01).结论 FCP对高温暴露大鼠睾丸组织的损伤具有保护作用.     

不同剂量葡萄籽原花青素对砷致雄性小鼠肝脏毒性拮抗作用研究

目的观察不同剂量葡萄籽提取物原花青素对三氧化二砷(As2O3)所致雄性小鼠肝脏毒性干预效果,研究其抗氧化损伤作用机制及其干预效果的差异。方法按体重分层将50只雄性昆明种小鼠随机分为5组:对照组(生理盐水0.9%)、As2O3组(4 mg/kg·bw)、和As2O3(4 mg/kg·bw)+GSPE低(100 mg/kg·bw)、中(200 mg/kg·bw)、高(400 mg/kg·bw)剂量组,每组10只,连续灌胃5周;称量小鼠体重、肝重,并计算其肝脏系数;测定肝脏组织的天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、T-AOC等指标,采用单因素方差分析对比组间差异。结果 As2O3组体重、GSH含量、T-AOC水平均低于对照组,肝重、肝脏系数、ALT、AST活力、MDA含量均高于对照组(P均<0.05);As2O3+GSPE(200、400)mg/(kg·bw)剂量组体重均高于As2O3组(P均<0.05);As2O3+GSPE(100、200、400)mg/(kg·bw)剂量组肝重、肝脏系数、ALT、AST活力、MDA含量均低于As2O3组(P均<0.05);GSH含量、T-AOC水平均高于As2O3组(P均<0.05)。As2O3+GSPE低剂量组小鼠体重比As2O3+GSPE中剂量组低(P<0.05);As2O3+GSPE低、中、高剂量组GSH含量(137.17±34.70)μmol/g prot、(198.02±41.28)μmol/g prot、(272.06±35.85)μmol/g prot、T-AOC水平(5.33±0.76)U/mL、(7.07±0.83)U/mL、(11.54±1.86)U/mL依次增高(P<0.05)。结论 GSPE可能通过抗氧化损伤作用拮抗As2O3致雄性小鼠的肝脏毒性,高剂量GSPE干预效果较好。     

硫酸镁对小鼠肾缺血再灌注损伤保护作用

目的 观察硫酸镁对小鼠肾缺血再灌注损伤的抗氧化保护作用.方法 雄性小鼠随机分为假手术组、模型组和硫酸镁高、低剂量(120、60 mg/kg)组,无创动脉夹夹闭左肾蒂45 min和再灌注3h制备急性肾缺血再灌注损伤模型,检测肾脏指数、血清尿素氮(BUN)和肌酐含量、肾组织丙二醛(MDA)含量以及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力,HE染色观察肾组织学变化.结果 硫酸镁高、低剂量组小鼠肾指数分别为(0.72±0.05)和(0.74±0.07)、血清BUN含量为(12.36±2.24)和(15.58±1.92) mmol/L、血清肌酐水平为(98.23±4.37)和(114.63±6.24) μmol/L、肾组织MDA含量为(2.11±0.24)和(2.27±0.21) nmol/(mg·prot),肾组织SOD活力为(4.03±0.68)和(3.51±0.58) U/(mg·prot),硫酸镁高剂量组肾组织GSH-Px活力为(323.90±23.50)U/( mg· prot),与模型组比较,差异均有统计学意义(P＜0.05),且肾组织病理变化较轻.结论 硫酸镁对小鼠急性肾缺血再灌注损伤具有保护作用,其机制可能与抑制脂质过氧化反应有关.     

饮水染镉对大鼠睾丸及血液抗氧化功能影响

目的探讨饮水染镉对雄性大鼠睾丸及血液抗氧化功能影响。方法将30只雄性SD大鼠(性成熟)随机分成5组,分别为对照组,25、50、100、200 mg/L Cd Cl2组,经饮水染镉,连续56 d;检测大鼠睾丸、血液中谷胱甘肽过氧化物酶(GSH-Px)活性、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量。结果与对照组比较,200 mg/L染镉组大鼠睾丸中GSH-Px活性[(7.94±2.25)μmol/(min·gprot)]降低(P<0.05),MDA含量[(5.84±0.61)nmol/mgprot]明显升高(P<0.01);与对照组比较,200 mg/L染镉组大鼠全血GSH-Px活性[(32.99±4.45)μmol/(min·gprot)]、红细胞SOD活性[(8 574.79±887.65)NU/g Hb]、血浆SOD活性[(9.94±1.38)NU/mgprot]明显下降(P<0.05),血浆MDA含量[(0.26±0.03)nmol/mgprot]明显上升(P<0.05)。结论饮水染镉可引起雄性大鼠睾丸及血液抗氧化功能损伤。     

维生素C对甲醛胚胎发育毒性抑制作用

目的 探讨维生素C(VC)对甲醛诱导胎鼠发育毒性的影响.方法 应用体外全胚胎培养模型,观察100μg/mL VC对终浓度为9,27,81 μmol/L甲醛诱导昆明种小鼠胚胎发育毒性的影响.结果 与对照组比较,9μmol/L甲醛可使胚胎头长、颅臀长、谷胱甘肽(GSH)、丙二醛(MDA)含量分别升高到(1.66±0.21),(3.48±0.40)mm,(47.70±2.12)me,/(g·prot),(4.27±0.62)nmol/(mg·prot),差异有统计学意义(P<0.05);27 μmol/L甲醛使胚胎脏层卵黄囊(VYS)直径、头长、颅臀长、体节数、GSH含量分别下降到(4.35±0.65),(1.48±0.30),(3.19±0.43)mm,(25.2±1.2)对,(40.25±4.38)mg/(g·prot),MDA含量升高到(6.29±0.47)nmol/(mg·prot),与对照组比较,差异有统计学意义(P<0.05);VC能明显改善上述指标,但与对照组比较差异无统计学意义(P<0.01);VC不能明显改善81 μmol/L甲醛诱导的毒性损伤.结论 VC对一定剂量范围内的甲醛胚胎毒性具有明显抑制作用.     

三氧化二砷染毒小鼠肝脏中砷甲基化水平与肝脏氧化应激的关系

目的探讨三氧化二砷(As2O3)染毒小鼠肝脏组织中砷甲基化水平的变化及其与肝脏氧化应激关系,为揭示砷甲基化水平在砷毒性机制中的作用提供依据。方法将40只昆明种小鼠随机分为对照组(0.9%生理盐水)、As2O3低中高剂量组(1.0、2.0和4.0 mg/kg)组,连续灌胃5周;采用高效液相色谱与原子荧光联用技术(HPLC-HGAFS)测定肝脏组织中三价无机砷(As3+)、五价无机砷(As5+)、一甲基胂(MMA)、二甲基胂(DMA)含量及构成比(%),计算砷一甲基化指数(PMI)、二甲基化指数(SMI);利用试剂盒测定丙二醛(MDA)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)。结果随着As2O3剂量增加,小鼠肝脏组织中各形态砷代谢产物含量增加(P0.001),砷甲基化水平(i As%、MMA%、DMA%、PMI、SMI)提高(P0.001);小鼠肝脏MDA显著高于对照组(P0.001),GSH、SOD、T-AOC显著低于对照组(P0.001);1 mg/kg染毒剂量时,PMI与T-AOC呈负相关(P0.05),SMI与GSH、SOD呈负相关(P0.05);在2 mg/kg染毒剂量时,PMI、SMI与MDA呈正相关(P0.05)而与GSH、SOD呈负相关(P0.05);在4 mg/kg染毒剂量时,PMI与MDA呈正相关(P0.05),PMI、SMI与GSH、SOD呈负相关(P0.05)。结论随着砷染毒剂量的增加,小鼠肝脏组织中各种形态砷含量增多,砷甲基化水平提高,进而导致小鼠肝脏氧化损伤严重。     

海藻萜类化合物联合VE对酒精性肝损伤大鼠影响

目的 研究凹顶藻萜类化合物(Laurencia extract,LET)与维生素E(VE)合用对乙醇诱导肝损伤大鼠的影响及其作用机制.方法 70只雄性Wistar大鼠随机分为7组.除空白组每天给予蒸馏水灌胃外,其余各组均每天乙醇12 mL/(kg·bw)灌胃,各干预组分别给予不同剂量LET加VE、VE、甘利欣灌胃,6周后测定血清肝功、血脂及肝匀浆中抗氧化指标.结果 不同剂量LET合用干预组血清肝功、血脂水平与乙醇模型组比较,差异有统计学意义(P<0.05);LET中、高剂量合用干预组谷胱甘肽过氧化物酶(GSH-Px)活力分别为(59.523±11.015),(59.541±13.724)U/(mg·prot);丙二醛含量(MDA)分别为(5.018±1.239),(4.799±1.628)nmol/(mg·prot);高剂量合用干预组超氧化物歧化酶活力(SOD)为(147.690±9.989)U/(mg·prot),与乙醇模型组GSH-Px(45.624±10.589)U/(mg·prot)、MDA含量(10.593±1.716)nmol/(mg·prot)、SOD活力(100.153±13.632)12/(mg·prot)比较,差异有统计学意义(P<0.05).结论 LET与VE合用能调整酒精性肝损伤大鼠体内脂质代谢,改善肝功能,减少脂质过氧化产物,对酒精造成的机体损伤表现出相应的保护效应.     

叶黄素对砷致小鼠肝脏毒性的预防保护作用

目的观察提前给予小鼠叶黄素干预对砷肝脏毒性的预防效果。方法将84只SPF级昆明种小鼠,雌雄各半,随机分为35 d空白组、70 d空白组、35 d单纯叶黄素组、70 d单纯叶黄素组、砷染毒组、35 d叶黄素拮抗组和70 d叶黄素预防组,按叶黄素40 mg/kg,As2O35 mg/kg剂量灌胃给药。测定血清中谷氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)活性,肝脏匀浆丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、还原型谷胱甘肽(GSH)含量、总抗氧化能力(T-AOC)及一氧化氮(NO)含量,采用单因素方差分析对比组间差异。结果砷染毒组AST和ALT活性、MDA含量显著高于70 d空白组,SOD活性、GSH及NO含量、T-AOC水平显著低于70 d空白组(P<0.05);70 d叶黄素预防组AST及ALT活性、MDA含量低于35 d叶黄素拮抗组(P<0.05),SOD活性、NO及GSH含量、T-AOC水平均高于35 d叶黄素拮抗组(P<0.05)。结论提前给予叶黄素干预可以提高小鼠肝脏组织抗氧化损伤能力,从而拮抗砷的肝脏毒性作用。     

枳实对糖尿病小鼠肾脏抗氧化能力及胰岛影响

目的 研究枳实提取物对实验性糖尿病小鼠肾脏抗氧化能力及胰岛形态的影响.方法 将枳实提取物分成高、中、低剂量[5.1,3.4,1.7 g/(kg·bw)]治疗糖尿病小鼠4周后,观察其一般状况、肾脏的抗氧化能力及胰岛形态变化.结果 枳实高剂量组小鼠末期血糖为(20.37±5.25)mmol/L,明显低于糖尿病组的(25.74±2.99)mmol/L(P<0.05);枳实高剂量组谷胱甘肽(GSH)含量为[(34.40±8.54)mg/(g·prot)],明显高于糖尿病组的[(21.38±3.91)mg/(g·prot)](P<0.01);枳实高剂量组丙二醛(MDA)和NO含量分别为[(0.89±0.37)nmol/(mg·prot)],[(1.27±0.56)μmol/(g·prot)],明显低于糖尿病组的[(1.46±0.39)nmol/(mg·prot)],[(2.15±0.85)μmol/(g·prot)](P<0.01或P<0.05),光镜下枳实提取物治疗组胰岛细胞损伤程度较糖尿病组轻.结论 枳实提取物能增强肾脏的抗氧化能力;保护胰岛组织细胞并降低胰岛细胞损伤.     

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.