新农药叶枯灵的体外代谢转化研究

本文采用 HPLC、TLC、UV、IR 和 MS 对叶枯灵经体外代谢后所形成的代谢产物进行分离和鉴定。结果表明,叶枯灵经体外代谢后所形成的3种代谢产物分别为肼叉-1,3-二噻茂烷,2-苯甲酰肼叉-1,3-二噻茂烷-S-氧和苯甲酸。叶枯灵经酰胺酶的催化可进行水解作用。叶枯灵还可经肝微粒体混合功能氧化酶的作用进行 S-氧化反应。     

氚标记2-苯酰肼叉-1,3-二噻茂烷在大鼠体内的分布

为探讨新农药2-苯酰肼叉-1,3-二噻茂烷(BHD)在机体内的吸收、分布、排泄、蓄积及对胎盘屏障透过性,以氚标记该农药(~3H-BHD)并对染毒大鼠进行了观察。     

新农药叶枯灵的毒性研究

农药叶枯灵(原名“渝—7802”)系四川省重庆农药厂新研制的有机硫杀菌剂,其化学名药2-苯酰胼叉-1,3-二噻茂烷(2-benzoyl-yhdrazono-1,3-ditholane),分子式为C_(10)H_(10)NOS_2,系白色粉剂,易溶于二甲亚砜、丙酮等有机溶剂,难溶于水和油。经     

新农药2-苯酰肼叉-1,3-二噻茂烷的毒理研究

2-苯酰肼叉-1,3-二噻茂烷(渝-7802)为国内新试制的一种农业杀菌剂。经口LD_(50)小鼠为82.2mg/kg(雌)和73.7mg/kg(雄),大鼠为108.3mg/kg(雌)和138.8mg/kg(雄)本品属中等毒类农药,可经胃肠道和呼吸道吸收,但不易经皮吸收,对皮肤粘膜无明显刺激作用。在大鼠体内无明显蓄积作用和致畸作用。Ames试验和染色体畸变试验阴性。     

经口和吸入~(14)C-氯乙烯在大鼠体内的转归

业已表明氯乙烯对大鼠和人有致癌性。据报道部分氯乙烯代谢成为极性产物从尿中排出。其转归与剂量有关,并可能有二种以上的代谢途径,根据资料推测氯乙烯的致癌活性是可能通过形成烷化代谢产物,如氯乙醛、氧化氯乙烯所致。作者采用~(14)G-氯乙烯(放射化学纯度95～96%),对大鼠进行经口和吸入染毒的药理动力学和代谢的研究。[方法]成年雄性大鼠,4～5只为一组。吸入染毒共二组,分别吸入氯乙烯10和1,000ppm 6小时,比括性分别为4,848(10 ppm)和     

尿中2-硫代噻唑烷-4-羧酸的高压液相色谱法测定

本文采用酸性乙醚提取,高压液相色谱测定的方法对二硫化碳在尿中的代谢产物2-硫代噻唑烷-4-羧酸(TTCA)进行了分析。结果表明,本法灵敏度高,干扰少,应用范围广,且线性范围,精密度,回收率亦均符合定量分析的要求,适用于二硫化碳的生物监测工作。     

全二维气相色谱串联质谱法测定全血中萘烷及其代谢产物

目的 建立全血中萘烷及其代谢产物(萘烷醇、萘烷酮)的全二维气相色谱检测方法。方法 全血经环己烷提取、固相萃取柱净化后，采用Rxi-5Sil MS作一维柱、DB-17 MS作二维柱进行分离，质谱仪检测，以外标法定量。结果 萘烷及其代谢产物萘烷醇、萘烷酮在二维谱图上有效分离，检出限为7～9μg/L,定量限为19～27μg/L,在0～5μg/mL范围内线性关系良好(r>0.999)。血液样本平均加标回收率为96.4%～102.8%,相对标准偏差(RSD)为3.1%～5.9%。结论 建立的方法简便灵敏，分离度好，回收率高，适用于血液样本中萘烷及其代谢产物的检测。     

气相色谱—质谱联机分离鉴定叶枯灵的代谢物

经口灌胃给大鼠叶枯灵35.8mg/kg,收集24小时尿,采用气相色谱—质谱(GC—MS)联机分离和鉴定了尿中的主要代谢物。据此推断,叶枯灵进入体内迅速水解,继而在氮原子上乙酰化,并用化学合成品对照确证,该法灵敏度高,分离效果好。     

同时检测人尿中六种大豆异黄酮代谢产物的HPLC法

目的研究建立双波长同时检测人尿中大豆异黄酮代谢产物雌马酚等6种化学成分含量的高效液相色谱分析方法。方法尿样品用β-葡萄糖苷酶水解,乙酸乙酯萃取;采用乙酸乙酯-甲醇-0.05%磷酸盐缓冲液作为流动相,梯度洗脱;程序波长紫外检测器检测,检测波长为254nm、280nm。结果方法的线性范围为0.05～10μg/ml;检出限为0.03～0.05μg/ml,定量限为0.1～0.17μg/ml;6种成分的平均回收率为71.4%～102.1%;相对标准偏差为1.0%～7.9%。应用新建立的方法测定了10份人尿样品中6种活性化学成分的含量。结论该方法可靠,适用于人尿中大豆异黄酮代谢产物的分析检测。     

农药叶枯灵对大鼠离体灌流肝的影响研究

进行了叶枯灵的大鼠肝脏离体循环式灌流肝实验研究,结果表明,灌流肝正常功能至少可维持2小时,叶枯灵在500uM 时,对大鼠灌流肝有毒作用,LDH 酶活性及 K~+浓度对评价叶枯灵的有毒作用是敏感的指标。本文建立了大鼠离体灌流肝的模型,适用于化合物的毒性及代谢的研究。     

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.