自然杀伤细胞活性测定方法的可行性研究

目的通过研究已知的免疫抑制剂环磷酰胺对大鼠自然杀伤细胞(NK细胞)功能的影响,说明NK细胞活性测定方法用于非特异性免疫毒性评价的可行性。方法雄性Wistar大鼠40只,体重180~200 g,随机分为对照组和2、5、10 mg/kg环磷酰胺染毒组,每组10只大鼠,各剂量组每日灌胃染毒1次,连续28 d,对照组给予生理盐水。染毒结束后24 h,断头处死大鼠,取脾脏,制备浓度为5×106/ml的脾细胞悬液,采用乳酸脱氢酶释放法评价NK细胞对靶细胞(YAC-1细胞)的杀伤活性。结果10 mg/kg环磷酰胺染毒组大鼠的NK细胞活性(25.6%±11.8%)低于对照组的NK细胞活性(44.6%±15.3%),差异有统计学意义(P<0.05)。结论NK细胞活性测定方法用于非特异性免疫毒性评价具有可行性。     

脂多糖及伴刀豆球蛋白A诱导脾淋巴细胞增殖试验方法用于免疫毒性评价的可行性研究

目的研究脂多糖(LPS)及伴刀豆球蛋白A(ConA)诱导脾淋巴细胞增殖试验的两种方法用于免疫毒性评价的可行性。方法雄性Wistar大鼠40只,体重180~200 g,随机分为对照组和2,5,10 mg/kg环磷酰胺染毒组,每组10只大鼠,各剂量组每日灌胃染毒1次,连续28 d,对照组给予生理盐水。染毒结束后24 h,断头处死大鼠,取脾脏,制浓度为3×106个/ml的脾细胞悬液,用MTT方法进行LPS及ConA诱导脾淋巴细胞增殖试验。结果10 mg/kg环磷酰胺染毒组大鼠的B淋巴细胞和T淋巴细胞的增殖能力(吸光度值,分别为0.032±0.037和0.028±0.050)低于对照组的B淋巴细胞和T淋巴细胞的增殖能力(分别为0.124±0.093和0.458±0.320),差异有统计学意义(P<0.05)。结论LPS及ConA诱导脾淋巴细胞增殖试验的两种方法用于免疫毒性评价具有可行性。     

冷烫液对小鼠的免疫毒性作用

目的 研究冷烫液对小鼠免疫功能的影响。方法 选择体重18－22g的雌性昆明小鼠每组10只,以冷烫液12．5、250、1000mg/kg灌胃染毒3周后进行体液免疫、细胞免疫、非特异性免疫及免疫脏器重量测试。结果 250、1000mg/kg剂量组的胸腺和脾脏重量明显低于对照组（P＜0．05,P＜0．01）,空斑形成细胞对数值、血清溶血素抗体体积、足跖厚度及碳郭清指数均低于对照组（P＜0．05,P＜0．01）。结论 冷烫液对小鼠的免疫功能有毒性作用。     

敌匹硫磷对Balb/c小鼠免疫功能影响

目的 观察敌匹硫磷对小鼠细胞免疫功能和体液免疫功能的影响.方法 将敌匹硫磷以1.6,3.2,6.3,12.5和25 mg/kg剂量灌胃染毒小鼠,4周后观察小鼠免疫功能的变化.采用T淋巴细胞增殖和迟发型变态反应来评价细胞免疫功能,采用血清溶血素测定和抗体生成细胞检测来评价体液免疫功能,采用乳酸脱氢酶法测定自然杀伤细胞(NK细胞)活性来评价非特异性免疫功能.结果 敌匹硫磷染毒4周后,6.3 me,/kg组小鼠的体液免疫功能和迟发型变态反应受到抑制;12.5,25 mg/kg组小鼠的胸腺脏器系数均降低20%,抗体生成细胞数分别降低39%和52%,血清溶血素水平分别降低15%和20%,迟发型变态反应水平分别降低33%和35%,淋巴细胞增殖能力分别下降27%和35%,NK细胞活性分别下降24%和28%.结论 敌匹硫磷对Balb/c小鼠的体液免疫功能、细胞免疫功能以及非特异性免疫功能均有抑制作用,体液免疫功能对其毒性更为敏感.     

环磷酰胺染毒对大鼠迟发型过敏反应的影响

目的建立大鼠28 d染毒的免疫毒性模型,并验证该方法检测迟发型过敏反应[Delayed-typehypersensitivity(DTH)reaction]的可行性。方法Wistar大鼠80只,雌雄各半,体重180~200 g,随机分为对照组和5,15,30 mg/kg环磷酰胺染毒组,染毒组每日灌胃染毒1次,连续染毒28 d;染毒第24天用1%二硝基氟苯溶液300μl涂抹大鼠背部皮肤进行致敏,染毒结束后,将1%二硝基氟苯溶液50μl涂抹大鼠右耳(两面);24 h后处死大鼠,剪下左右耳郭;用打孔器取下直径10 mm的耳片并称重;用左、右耳片重量之差表示DTH程度。对照组用生理盐水灌胃,其他处理同染毒组。结果15 mg/kg和30 mg/kg染毒组的雄性大鼠DTH程度分别为(45.4±23.2)mg和(10.7±7.1)mg,明显低于对照组(61.6±14.5)mg,差异有显著性(P<0.05);15 mg/kg和30 mg/kg染毒组雌性大鼠DTH程度分别为(27.4±9.8)mg和(21.3±11.0)mg,明显低于对照组(48.0±8.4)mg,差异有显著性(P<0.05);雄、雌性大鼠DTH程度的减低均具有明显的剂量-反应关系。结论大鼠28 d环磷酰胺经口染毒(15 mg/kg和30 mg/kg)可引起其特异性细胞免疫功能减低,同时也验证了该方法检测DTH的可行性。     

蒜氨酸+蒜酶对环磷酰胺处理小鼠免疫功能的影响

目的探讨蒜氨酸+蒜酶对环磷酰胺所致免疫功能低下小鼠体液免疫功能的免疫调节作用。方法采用环磷酰胺腹腔注射法建立免疫抑制模型,给予蒜氨酸+蒜酶,观察小鼠免疫器官重量及腹腔巨噬细胞吞噬率,测定血清半数溶血值(HC50)。结果对环磷酰胺所致免疫低下小鼠,蒜氨酸+蒜酶可明显提高腹腔巨噬细胞吞噬功能(P<005),促进血清溶血素形成,但对免疫器官重量无影响。结论蒜氨酸+蒜酶对环磷酰胺所致体液免疫功能低下有免疫保护作用,对其非特异免疫、特异性体液免疫都有上调作用。     

野生牛肝菌保健功能研究

目的观察野生牛肝菌对昆明种小鼠免疫功能的影响和对SD大鼠的降血脂作用。方法 (1)免疫功能实验:实验设野生牛肝菌组9.0 g/(kg bw)+环磷酰胺(CP)、CP组、正常对照组。灌胃小鼠牛肝菌提取液35 d,CP腹腔注射造成小鼠免疫损伤。观察小鼠胸腺脏器系数、血清溶血素、小鼠足趾DTH、碳粒廓清指数α等指标。(2)降血脂实验:设3个野生牛肝菌剂量组4.0、8.0、16.0 g/(kg bw)、阴性对照组和高脂模型对照组。各剂量组大鼠灌胃牛肝菌提取液30 d,对照组灌胃等量蒸馏水,在试验结束时取大鼠血清测定TG、CHO、LDH 3个指标。结果 (1)免疫功能试验中免疫损伤的小鼠血清溶血素(HC50)、小鼠足趾DTH、碳粒廓清指数α明显高于CP组,差异有统计学意义(P<0.01),其中小鼠足趾DTH恢复至正常对照组水平。(2)各剂量组的血脂指标与高脂对照组差异无统计学意义(P>0.01)。结论在本实验条件下,野生牛肝菌对CP所致的免疫损伤小鼠细胞免疫、体液免疫、非特异性免疫功能有明显改善作用,但不能预防大鼠的高脂血症。     

富右旋反式炔丙菊酯原药对大鼠的致畸作用

目的 观察富右旋反式炔丙菊酯对大鼠的致畸作用.方法 根据<农药登记毒理学试验方法>(GB15670-1995)进行试验.分别设4、20、100 mg/kg 3个富右旋反式炔丙菊酯原药染毒组,另设玉米油溶剂对照组和环磷酰胺阳性对照组.每组孕鼠12只.结果 与溶剂对照组比较,各染毒组孕鼠的黄体数、着床数、活胎率、死胎率和吸收胎率、染毒组胎鼠的体重、身长和尾长均未见明显改变,3个染毒组和溶剂对照组均未见外观畸形、内脏畸形和骨骼畸形;100 mg/kg组妊娠第16天和第20天孕鼠的体重分别为(339.7±13.1)g和(372.2±17.8)g,明显低于溶剂对照组[(356.2±19.3)g和(394.3±16.1)g].结论 在本实验条件下,富右旋反式炔丙菊酯原药对大鼠母体具有一定的毒性,无作用剂量为20 mg/kg;未发现胚胎毒性和致畸作用.     

蜂胶软胶囊对小鼠免疫调节功能的影响

目的根据原卫生部2003年发布的《保健食品检验与评价技术规范》要求,探索蜂胶软胶囊对小鼠免疫调节功能的影响。方法经口给予小鼠不同剂量的受试物蜂胶软胶囊30 d后,通过抗体生成细胞数和血清溶血素含量测定,观察其对小鼠体液免疫的影响;通过迟发型变态反应和Con A诱导的小鼠脾淋巴细胞转化试验,研究受试物对小鼠细胞免疫的影响;通过碳粒廓清试验和小鼠腹腔巨噬细胞吞噬鸡红细胞试验以及NK细胞的活性测定,评价蜂胶软胶囊对小鼠非特异性免疫功能的影响。结果与溶剂对照组比较,受试物高剂量组小鼠溶血空斑数和血清溶血素水平显著提高(P0.01),中剂量组小鼠仅溶血空斑数增加明显(P0.01);受试物高剂量组小鼠DTH和脾淋巴细胞增殖能力显著增强(P0.05);中剂量组仅小鼠脾淋巴细胞增殖能力增强(P0.05);受试物高剂量组、中剂量组小鼠单核巨噬细胞吞噬能力显著提高(P0.01)。结论本试验条件下,蜂胶软胶囊可能是通过提高小鼠的特异性和非特异性免疫功能从而增强机体免疫力。     

市售防蛀剂(含对二氯苯)亚急性染毒对小鼠免疫功能的影响

目的研究市售防蛀剂(含对二氯苯)对小鼠免疫器官、单核-巨噬细胞、细胞免疫、体液免疫功能的影响.方法用ICR雄性小鼠随机分为5组:阴性对照组用食用油;实验组分为190、375、750 mg/kg防蛀剂灌胃染毒30 d;阳性对照组用环磷酰胺50 mg/kg隔日腹腔注射,共2次.采用免疫器官系数、碳粒廓清指数、血清溶血素及迟发性变态反应(足跖增厚法)指标,观察对小鼠免疫功能的影响.结果高剂量组小鼠胸腺系数减小(P＜0.01),中、高剂量组小鼠肝脏系数明显增加(P＜0.01),吞噬指数明显降低(P＜0.05),血清溶血素抗体水平降低,对迟发性变态反应无影响.结论在本实验剂量与条件下,该防蛀剂具有抑制小鼠胸腺发育、引起肝脏肿大,对单核-吞噬细胞有抑制作用,降低血清溶血素,对小鼠免疫功能有抑制作用.     

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.     

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.     

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.     

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.     

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.