甲醛-苯联合染毒对小鼠的致突变作用

目的探讨甲醛、苯对小鼠的联合致突变作用。方法采用昆明种小鼠64只,分阴性对照组、甲醛组、苯组、联合组、阳性对照组,进行小鼠骨髓细胞微核试验及精子畸形试验。结果甲醛组、苯组小鼠骨髓细胞微核率及精子畸形率均明显高于各自的阴性对照组(P<0.01);甲醛和苯联合染毒诱发小鼠骨髓细胞微核率为14.1‰,精子畸形率为16.26%,二者单独染毒所引发的骨髓细胞微核率之和为13.6‰,精子畸形率之和为16.74%,与联合染毒所引发的骨髓细胞微核率(14.1‰)和精子畸形率(16.26%)基本相同。结论甲醛和苯联合染毒对小鼠骨髓细胞及精子的致突变作用属于相加作用。     

丙烯腈对大鼠睾丸抗氧化酶活力和脂质过氧化水平的影响

目的　探讨丙烯腈(ACN)的雄性生殖毒性机制。方法　健康雄性SD大鼠分别以0、7.5、15.0、30.0 mg/kg剂量腹腔注射ACN染毒,测定其睾丸谷胱甘肽(GSH)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH Px)、谷胱甘肽S 转移酶(GST)活力。结果　ACN染毒4周后,15.0、30.0 mg/kg组大鼠睾丸GSH含量[(7.44±0.96)、(6.95±0.77)mg/g pro]增加,30.0 mg/k组大鼠GSH Px活力[(70.89±4.01)U/mg pro]升高,与对照组的差异均有统计学意义(P<0.05,P<0.01)。ACN染毒8周后,30.0 mg/kg组大鼠睾丸GSH含量[(2.50±0.94)mg/g pro]降低,15.0、30.0mg/kg组大鼠SOD活力[(102.08±16.08)、(113.30±17.20)NU/mg pro]升高,与对照组的差异均有统计学意义(P<0.01)。ACN染毒13周后,15.0、30.0 mg/kg组大鼠睾丸GSH含量降低,30.0 mg/kg组GST活力下降,各染毒组GSH Px活力均低于对照组,30.0 mg/kg组MDA含量[(0.68±0.16)nmol/mgpro]高于对照组[(0.38±0.12)nmol/mg pro],差异均有统计学意义(P<0.01)。停止染毒后2周,大鼠睾丸GSH水平恢复;30.0 mg/kg组大鼠睾丸MDA含量下降,但仍高于对照组,GSH Px活力仍低于对照组,差异均有统计学意义(P<0.05)。结论　ACN能通过破坏氧化-抗氧化体系的平衡,诱导雄性大鼠睾丸脂质过氧化损伤。     

三氯乙烯致小鼠血浆脂质过氧化作用的研究

目的 探讨三氯乙烯(TCE)对小鼠血浆脂质过氧化作用.方法 小鼠经口灌胃给予不同剂量(0,500,1 000,2 000 mg/kg体重)的TCE,连续4 d.末次染毒后24 h,断头处死动物,制备血浆,分别测定血浆中的超氧化物歧化酶(SOD)活力、丙二醛(MDA)及活性氧(ROS)含量,并与阴性对照组比较.结果 TCE低、中、高剂量染毒组血浆中MDA(280.00 ±18.63、338.86±10.62、470.91±103.06 nmol/ml)、ROS(887.65±84.04、934.92±52.52、997.95±162.82 U/ml)含量明显高于对照组(221.14±33.11 nmol/ml,837.76士430.70 U/ml)(均P＜0.001).SOD活力(515.43±102.63、256.87±48.58、130.41±60.07 U/ml)低于对照组(711.66±69.90 U/ml)(P＜0.001),且染毒剂量与MDA、ROS含量呈正相关,与SOD活力呈负相关.各指标在不同性别没有显著性差异(P＞0.05).结论 TCE经口染毒可引起小鼠血浆脂质过氧化反应.     

苯和二硫化碳诱导小鼠骨髓嗜多染红细胞微核的研究

目的探讨苯和二硫化碳对雌性小鼠体细胞遗传物质的影响.方法采用静式吸入法分别用苯和二硫化碳染毒NIH成年雌性小鼠15 d(2 h/d),分析受试小鼠骨髓嗜多染红细胞微核细胞率.结果苯染毒低、中、高剂量组浓度分别为706、1 922、4 864 mg/m^3,三剂量组的微核细胞率依次为7.2‰、7.3‰、8.3‰,与阴性对照组(2.1‰)比较有显著性差异(P＜0.05),二硫化碳染毒低、中、高剂量组浓度分别为199、651、1 209 mg/m^3,三剂量组的微核细胞率依次为3.0‰、4.2‰、5.1‰,中剂量组和高剂量组与阴性对照组比较有显著性差异(P＜0.05),具有较好的剂量-效应关系.结论苯和二硫化碳均能诱导雌性小鼠体细胞微核增加.     

番茄汁对镉中毒小鼠肝肾损伤保护作用

目的 探讨番茄汁的促排镉作用及对肝肾损伤的影响.方法 小鼠饲喂CdCl2和番茄汁,4周后处死,测定肝、肾镉含量,血清尿素氮(BUN)及谷丙转氨酶(ALT)的含量,血、肝、肾超氧化物岐化酶(SOD)活性、丙二醛(MDA)含量、谷胱甘肽过氧化物酶(GSH-Px)活力.结果 番茄汁低剂量组肝、肾镉含量为[(12.4±0.52),(9.3±0.37)μg/g]与镉染毒组[(15.6±0.11),(11.2±0.45)μg/g]比较,明显降低(P＜0.01),血ALT、BUN含量[(204.4±15.2),(11.1±2.05)]mmol/L明显低于镉染毒组[(502.5±21.3)、(14.5±3.15)]mmol/L(P＜0.01),血、肝、肾MDA含量分别为[(10.5±1.2),(10.7±2.1),(11.3±1.2)nmol/mgprot],明显低于镉染毒组(P＜0.01),血、肝、肾SOD、GSH-Px的活性明显升高(P＜0.01),呈剂量效应关系.结论 番茄汁对镉中毒小鼠肝、肾损伤具有一定保护作用,其机制可能与增强小鼠抗氧化能力有关.     

刺五加、葡萄籽提取物方剂对衰老模型小鼠肝脏细胞凋亡及氧化应激的影响

目的研究刺五加、葡萄籽提取物方剂对衰老模型小鼠肝脏细胞凋亡及氧化应激的影响。方法SPF级昆明种雄性小鼠50只,随机分1组阴性对照组(10只)和4组D-半乳糖模型组(每组各10只),模型组以1ml/(kg.bw)的剂量连续腹腔注射150mg/(kg.bw)的D-半乳糖2个月后,分为模型对照组和刺五加、葡萄籽提取物方剂低、中、高3个剂量组。各剂量组灌胃分别给予0.16、0.33、1.00g/(kg.bw)的刺五加、葡萄籽提取物方剂,模型对照组灌胃给予相应体积的纯净水,同时各组腹腔注射150mg/(kg.bw)的D-半乳糖,连续60d后取肝脏。通过AnnexinV/PI联合标记染色肝细胞,以流式细胞仪在Ex=488nm条件下,CellQuest软件分析肝细胞凋亡率;同时以分光光度法检测肝脏氧化应激状态。结果在Contourplot图上,根据肝细胞标记染料AnnexinV/PI的强度可见,中、高剂量组肝细胞凋亡百分率分别为(30.94±7.59)%、(29.35±5.58)%,均低于模型对照组[(47.99±11.95)%](P<0.01)。中、高剂量组MDA含量[(1.64±1.30)、(1.57±1.72)nmol/mg]均低于模型对照组[(3.92±0.73)nmol/mg](P<0.01);中、高剂量组SOD活性[(162.92±18.04)、(175.53±24.65)NU/mg]均高于模型对照组[(135.77±29.16)NU/mg](P<0.05);而各剂量组GSH-Px活性与模型对照组比较差异均无统计学意义(均P>0.05)。结论刺五加、葡萄籽提取物方剂可减少衰老模型小鼠肝细胞凋亡的发生,通过降低MDA含量和升高SOD活性增加机体对氧化应激反应的能力。     

包头市水源水及其自来水中有机提取物对小鼠氧化性损伤及遗传毒性研究

目的 探讨黄河包头段水源水及其自来水中有机提取物对小鼠的氧化性损伤及遗传毒性影响.方法 于2005年4月,采集黄河包头段上、中、下游水源水及其自来水.将昆明种健康小鼠按体重随机分成14组,每组10只,雌、雄各半.分别设自来水组、上游水组、中游水组和下游水组[每组中分低(2 L/ml)、中(5 L/ml)、高剂量组(10 L/ml)]、阴性对照组(DMSO)、阳性对照组(环磷酰胺).染毒组和阴性对照组按0.01 ml/g对小鼠进行灌胃,每天灌胃1次,连续5 d.末次染毒6 h后,测定各组小鼠肝脏、肾脏中超氧化物岐化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力以及丙二醛(MDA)的含量.计算小鼠骨髓细胞微核率.结果 中、下游水染毒组肝组织SOD和GSH-Px活力均随染毒剂量增加呈下降趋势;4种水样染毒组肾组织SOD活力在低剂量组较对照组升高,然后呈下降趋势;3种水源水染毒组肾组织GSH-Px活力随染毒剂量增加呈下降趋势;肝肾组织MDA含量随染毒剂量增加呈上升趋势,且存在不同程度的统计学意义.除自来水低剂量组外,各染毒组的微核率均高于阴性对照组,低于阳性对照组;在相同剂量组中,水源水染毒的小鼠骨髓细胞微核率均高于自来水,差异有统计学意义(P＜0.01).且中游水染毒的小鼠骨髓细胞微核率最高.结论 黄河包头段水源水及其自来水中有机提取物对小鼠具有氧化性损伤作用和潜在的遗传毒性作用.     

重组葡激酶致突变作用研究

目的研究重组葡激酶的致突变作用.方法CHL细胞染色体畸变试验(±S9),剂量为4125、8250、16500AU/ml、Ames试验(±S9),剂量为16.5、165、1650、16500、165000AU/ml)和小鼠骨髓嗜多染红细胞微核试验(肌肉注射剂量为83.5、167.0、334.0mg/kg).结果CHL细胞染色体畸变率均小于5%;各剂量组TA97、TA98、TA100、TA102各试验菌株MR＜2;各剂量组小鼠骨髓嗜多染红细胞微核率均小于2.00‰.结论重组葡激酶在本试验条件下无致突变作用.     

口服亚硒酸钠和维生素E对高海拔地区心血管病患者甲状腺激素的影响

目的探讨使用亚硒酸钠和维生素E对高海拔地区心血管病患者甲状腺激素的影响.方法将心血管病患者随机分为3组A组42例患者口服亚硒酸钠,同时加服维生素E;B组28例患者口服亚硒酸钠;对照组20例,未服用亚硒酸钠及维生素E.观察对象分别于治疗前和治疗6个月后抽血检测血清硒(Se)、血浆谷胱甘肽过氧化物酶(GSH-Px)活力、丙二醛(MDA)含量及甲状腺激素(T3、T4)等指标,以观察远期疗效.结果治疗后A组和B组血清Se含量[(0.71±0.22)、(0.68±0.18)μmol/L]明显高于治疗前[(0.31±0.17)、(0.33±0.14)μmol/L],差异有显著性(P＜0.01);A组和B组血浆GSH-Px活力分别为(87.12±13.61)、(84.79±12.13)U/L,较治疗前[分别为(58.43±18.93)、(57.12±17.36)U/L]明显增加.A组和B组MDA含量[(4.86±1.18)、(4.18±1.23)nmol/ml]较治疗前[(8.66±0.96)、(8.71±0.87)nmol/ml]明显降低,差异均有显著性(P＜0.01);A组和B组患者T3和T4较对照组明显降低,趋于正常.血清Se与血浆GSH-Px呈正相关(r=0.781,P＜0.01),与MDA、T3、T4浓度呈负相关(r=-0.385;r=-0.687;r=-0.412,均P＜0.05).甲状腺激素恢复正常者A组31例(73.81%)、B组20例(71.42%);部分恢复者A组4例(9.52%)、B组2例(7.43%),其恢复率明显高于对照组,差异有显著性(P＜0.05),远期疗效较好.结论补充适量硒和维生素E可纠正高原环境下因低Se而引起的甲状腺激素代谢异常.     

汽车尾气对人体内脂质过氧化作用的影响

目的探讨汽车尾气对人体的脂质过氧化水平的影响,方法对170名长期接触尾气的交通警察和108名所接触尾气的健康人员为调查对象。分别测定血清中超氧化物歧化酶(SOD活力)、丙二醛(MDA)的含量并对其结果进行统计分析。结果接触组血清SOD活力低于对照组分别为(89.58±14.36)NU/ml和(116.83±20.78)NU/ml,MDA含量高于对照组,分别为(6.19±1.60)nmol/ml和(4.85±0.86)nmol/ml,且均差异有非常显著性(P<0.001)。2项指标的异常检出率均高于对照组,SOD异常率分别为40%和6.5%;MDA异常率分别为43.5%和10.2%,差异有非常显著性(P<0.001)。结论汽车尾气可引起接触者体内脂质过氧化水平和抗氧化酶活性的改变。     

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.     

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.     

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.     

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.     

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.