守宫木致CHL及V79细胞染色体畸变作用

目的 观察守宫木对体外培养细胞的遗传学毒性.方法 以守宫木提取液为受试物,不同浓度条件下染毒培养中国仓鼠肺成纤维细胞(CHL)及中国仓鼠肺细胞(V79)2株细胞系,观察中期分裂相细胞的染色体畸变率.结果 守宫木对CHL细胞的染色体致畸率很高(P<0.01),在50%浓度下,其直接致染色体畸变能力明显高于经S9代谢活化组,对CHL细胞的染色单体型畸变明显高于染色体型畸变.守宫木对V79细胞在50%浓度下,其直接的致染色体畸变效应不明显,经S9代谢活化,致突变效应与阴性对照组比较差异有统计学意义(P<0.05),染色单体型畸变仍高于染色体型畸变.结论 守宫木具有一定的诱发染色体畸变的遗传毒性.     

10种市售染发剂的安全性评价

目的研究市售染发剂的使用安全性现状,探讨使用染发剂对健康的可能效应与不良影响。方法采用眼刺激试验、Ames试验、体外细胞染色体畸变试验等方法检测10种从市场抽检的染发剂对兔和体外测试系统的影响。结果10种染发剂所含的染料中间体均较低,对实验兔染毒30s后冲洗试验呈现眼刺激性或腐蚀性,但4s后冲洗试验均呈轻刺激性或微刺激性;在Ames试验中,10种染发剂对TA97、TA98、TA100、TA102鼠伤寒沙门菌菌株的各染毒剂量组均呈现阴性反应,各种染发剂无细胞毒性时的最高染毒剂量为2000μg/皿或1500μg/皿,最低染毒剂量为125μg/皿;在中国仓鼠CHL细胞株体外细胞染色体畸变试验中,各种染发剂无细胞毒性时的最高染毒剂量为2500μg/ml至156μg/ml,最低染毒剂量为78μg/ml到19.5μg/ml,染色体畸变细胞率最高为7.5%(+S9)及5%(-S9),与对照相比差异均无统计学意义。结论目前市售的染发剂具有一定眼刺激性,但无明显遗传毒性作用;其对基因突变与染色体畸变的作用力较文献报道的同类产品低,可能与现在染发剂中染料中间体的含量减少有关。     

沙尘暴细颗粒物对人外周血淋巴细胞的遗传损伤效应

目的探讨沙尘暴细颗粒物(PM2.5)对人外周血淋巴细胞的遗传损伤.方法用采集自内蒙古包头市和甘肃武威市的沙尘暴和正常天气PM2.5不同浓度(0、33、100、300μg/ml)提取物染毒人外周血淋巴细胞,用染色体畸变试验和胞质阻断法进行畸变率和微核率统计.结果包头、武威沙尘暴和正常天气PM2.5提取物的100、300μg/ml剂量组人血淋巴细胞微核率均高于其对照组(均P＜0.01).包头、武威沙尘暴300μg/ml剂量组和正常天气PM2.5提取物的100、300μg/ml剂量组人血淋巴细胞核分裂指数均低于其对照组(P＜0.05或P＜0.01);染毒剂量与微核率呈正相关,与核分裂指数成负相关.不同浓度沙尘暴PM2.5提取物染毒能引起人外周血淋巴细胞染色体结构畸变,主要表现为染色体及染色单体断裂、缺失、成环、形成双着丝粒(染色体桥)、断片等,同时也明显增加了淋巴细胞染色体畸变率,且存在剂量-反应关系(P＜0.01).结论沙尘暴PM2.5能引起淋巴细胞遗传损伤,其遗传毒性主要与染毒剂量有关.     

亚硝酸钠对中国仓鼠肺细胞染色体畸变率的影响

[目的]研究亚硝酸钠(NaNO2)致中国仓鼠肺细胞(CHL)染色体畸变的作用. [方法]测定NaNO2对CHL细胞的半数抑制浓度(IC50),根据IC50设立不同剂量组,进行正式实验,分别观察不加及加S9后的染色体畸变情况,根据标准进行结果判定. [结果]NaNO2染毒在不加S9时,128、12.8和1.28μg/ml 3个剂量组的染色体畸变率均＞5%而≤10%,为可疑阳性,而高剂量组(1.28 mg/ml)畸变率＞10%而＜20%,为阳性反应.NaNO2染毒在加入活化系统S9后,各剂量组引起CHL细胞染色体畸变率在12.8和1.28 μg/ml 2个剂量组的染色体畸变率均＞5%而≤100%,为可疑阳性,而中(128μg/ml)和高(1.28 mg/ml)剂量组畸变率均＞10%而＜20%,为阳性反应. [结论]NaNO2在1.28 mg/ml剂量下可引起CHL细胞染色体畸变率增高.     

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。     

碲化镉量子点对CHL细胞染色体畸变作用研究

目的探讨碲化镉量子点(CdTe QDs)对中国仓鼠肺成纤维细胞(CHL)染色体畸变作用。方法用体外方法检测CdTe QDs在1.6、3.2、6.3、12.6、25.2μl/ml染毒浓度范围内,在代谢活化条件下(+S9)及非代谢活化条件下(-S9)CHL细胞的染色体畸变率。结果 CdTe QDs的代谢活化组(+S9)在染毒浓度为2.6μl/ml和25.2μl/ml浓度组CHL细胞染色体畸变率与对照组比较,显著增加(P<0.01),染色体畸变类型主要是染色体断裂、交换和碎片等。结论 CdTe QDs在代谢活化条件下(+S9)可能导致CHL细胞染色体畸变。     

复方菊苣粉急性经口毒性和遗传毒性研究

目的 研究复方菊苣粉的急性经口毒性和遗传毒性。方法 SD大鼠(体质量为170 g～190 g)20只，设15 g/(kg·bw)1个剂量组，进行急性经口毒性试验；小鼠骨髓嗜多染红细胞微核试验选用昆明种小鼠(体质量为25 g～30 g)50只，设2.5 g/(kg·bw)、5.0 g/(kg·bw)和10.0 g/(kg·bw)3个试验组，同时设阴性对照和阳性对照；体外哺乳类细胞染色体畸变试验：试验设11个复方菊苣粉剂量：-S9条件下设5.0 mg/ml、2.5 mg/ml和1.25 mg/ml 3个剂量；+S9条件下设2.18 mg/ml、1.09 mg/ml和0.55 mg/ml 3个剂量。同时设阴性对照，进行综合评价。结果 急性经口毒性试验：SD大鼠15 g/(kg·bw)剂量经口染毒后，2周内未见动物死亡，亦无明显的中毒症状或不良反应，判属无毒级别。遗传毒性试验：Ames试验、小鼠骨髓嗜多染红细胞微核试验和体外哺乳类细胞染色体畸变试验三项遗传毒性试验结果均为阴性。结论 复方菊苣粉属无毒级物质，未见遗传毒性作用。     

甲基丙烯酸环氧丙酯致人支气管上皮细胞染色体损伤的研究

目的研究甲基丙烯酸环氧丙酯(GMA)对人支气管上皮(16HBE)细胞染色体损伤的情况,探讨其潜在致癌性。方法 GMA染毒16HBE细胞后,收获不同染毒剂量(4、8、12、16、20μg/ml)、染毒次数(1、2、3次)、转化代数(10、30代)的细胞进行染色体畸变分析。结果在4～20μg/ml剂量范围内,随染毒剂量的增加,染色体畸变率(3%、6%、7%、11%、14%)升高,并呈剂量-反应关系;随着染毒次数增加,3次染毒的细胞染色体畸变率(6%、7%、10%)显著增高;转化第10代细胞表现为染色体结构畸变,而转化第30代细胞主要表现为染色体数目畸变。结论 GMA能够诱导16HBE细胞染色体畸变,且畸变类型由早期的结构畸变转变为数目畸变。     

守宫木Sauropus androgynus毒理学安全性评价

目的 研究守宫木的急性及亚慢性、细胞、遗传及免疫毒性并对其作出安全性评价.方法 对守宫木进行小鼠急性经口、大鼠亚慢性经口、细胞、遗传及免疫毒性试验.结果 全成份鲜样匀浆、叶干粉LD50值＞21.5 g/kg,梗干粉小鼠LD50值雌性20 g/kg、雄性23.3 g/kg;大鼠亚慢性经口毒性试验中干粉无明显有害作用剂量(NOAEL)为2 000 mg/kg;较低剂量守宫木对细胞生长有抑制作用,较高剂量则出现细胞增殖现象;浓缩除菌滤液剂量相当于含鲜样6×102mg/mL时,染色体畸变急剧增加,剂量达1.2×103 mg/mL时,细胞全部死亡;守宫木提取物对BALB/C小鼠脾T、B淋巴细胞体外增殖功能以及肿瘤坏死因子(TNF)、干扰素(IFN-γ)细胞因子的分泌功能均呈抑制作用,而对腹腔巨噬细胞吞噬功能呈刺激性增强作用.结论 守宫木为低毒或无毒类物质,对大鼠无明显急性毒性、亚慢性毒性,对免疫系统有一定毒物兴奋效应.     

吴茱萸对CHL细胞染色体畸变影响的研究

目的 探讨吴茱萸的主要生物碱(吴茱萸碱和吴茱萸次碱)以及柠檬苦素对CHL细胞染色体畸变的影响,对其遗传毒性进行初步研究.方法 用不同剂量的吴茱萸碱、吴茱萸次碱、柠檬苦素对CHL细胞进行体外染毒,观察其致CHL细胞染色体结构及数量的变化.结果 吴茱萸在0.5 mg/ml、0.05 mg/ml和0.005 mg/ml不同测试浓度下,在+S9和-S9条件下,与细胞作用4h及24h收集细胞进行染色体畸变分析,各剂量组染色体畸变率均在正常范围；吴茱萸次碱在0.5 mg/ml、0.05 mg/ml和0.005 mg/ml不同测试浓度下,在+S9和-S9条件下,与细胞作用4h收集细胞进行染色体畸变分析,各剂量组染色体畸变率均在正常范围,与细胞作用24 h,可诱发可重复性的阳性结果；柠檬苦素在2.5mg/ml、0.25 mg/ml和0.025 mg/ml不同测试浓度下,在+S9和-S9条件下,各剂量组染色体畸变率均出现可重复性的阳性结果.结论 在本试验所确定的测试条件下,吴茱萸次碱和柠檬苦素可导致CHL细胞染色体畸变.     

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.     

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.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.