冷损伤血管NO合成酶活力的变化及其生物学意义

目的 观察不同程度冷损伤血管ＮＯ合成酶（ＮＯＳ）活力的变化,并研究超氧化物歧化酶（ＳＯＤ）和ＶｉｔＣ对这各变化影响。方法分离Ｗｉｓｔａｒ大鼠主动脉,并在ＰＢＳ培育培养１小时,然后使其暴露于－２０℃环境。以全自动生化分析仪测定血管培养液中乳酸脱氢酶（ＬＤＨ）活力,以Ｇｒｉｅｓｓ化学法观测血管ＮＯＳ活力,以肾上腺肾自氧化法血管ＳＯＤ活力。结果 当血管暴露于－２０℃环境１、２、４分钟后,血管２液中ＬＤＨ     

利用限制性片段长度多态性分析检测乙醛脱氢酶基因2的基因型

人类摄入酒精主要通过Ⅰ型酒精脱氢酶和乙醛脱氢酶共同催化。为建立乙醛脱氢酶基因２（ＡＬＤＨ２）的基因型检测方法，本研究应用限制性片段长度多态性分析法（ＲＦＬＰ－ＰＣＲ）测定ＡＬＤＨ２的基因型。根据ＡＬＤＨ２的基因序理资料，设计一含一个碱基替代的限制性内切酶ＭｂｏⅡ的可识别位点。随后ＤＮＡ模板在下列条件扩增；变性；９４，１ｍｉｎ，退火；５７℃，３ｍｉｎ，延伸；７２℃１ｍｉｎ。３５个循环。聚合酶链反应产     

氯化甲基汞对卵巢细胞酶及其线粒体的影响

用氯化甲基汞（以１／２００ＬＤ５０、１／２０ＬＤ５０和１／２ＬＤ５０即０．１９２５ｍｇ／ｋｇ、１．９２５ｍｇ／ｋｇ和１９．２５ｍｇ／ｋｇ体重的剂量）给昆明种雌性小鼠经口染毒，然后测定卵巢细胞中的ＬＤＨ、Ｇ－６－ＰＤ和ＳＤＨ活性，同时做卵巢细胞线粒体的电镜观察。结果表明：各剂量组的ＬＤＨ、Ｇ－６－ＰＤ活性明显低于对照组（Ｐ＜０．０５）。１／２ＬＤ５０和１／２０ＬＤ５０组的ＳＨＤ活性也明显低于对照组（Ｐ＜０．０５）。从电镜看到线粒体膜较完整，但在１／２ＬＤ５０和１／２０ＬＤ５０组中的线粒体嵴数目减少，甚至完全消失，基质呈空泡状改变。总之，酶活性改变，能量代谢的异常和线粒体的损伤可能是氯化甲基汞造成卵巢细胞功能改变的重要原因。     

甲基汞对卵巢细胞酶及其线粒体的影响

用氯甲基汞（以１／２００ＬＤ５０、１／２０ＬＤ５０和１／２ＬＤ５０即０．１９２５ｍｇ／ｋｇ、１．９２５ｍｇ／ｋｇ和１９．２５ｍｇ／ｋｇ体重的剂量）给昆明种雌性小鼠经口染毒，然后测定卵巢细胞中的ＬＤＨ、Ｇ－６－ＰＤ和ＳＤＨ活性，同时做卵巢细胞线粒体的电镜观察。结果表明：各剂量组的ＬＤＨ、Ｇ－６－ＰＤ活性明显低于对照组（Ｐ＜０．０５）。１／２ＬＤ５０和１／２０ＬＤ５０组的ＳＤＨ活性也明显低于对照组（Ｐ＜０．０５）。从电镜看到线粒体膜较完整，但在１／２ＬＤ５０和１／２０ＬＤ５０组中的线粒体嵴数目减少，甚至完全消失，基质呈空泡状改变。总之，酶活性改变，能量代谢的异常和线粒体的损伤可能是氯化甲基汞造成卵巢细胞功能改变的重要原因。     

砷与铅对人及大鼠红细胞脂质过氧化作用的影响

通过体内体外实验探讨了砷与铅对机体脂质过氧化（ＬＰＯ）的联合作用。用离体人红细胞膜染毒，砷（Ａｓ２Ｏ３）在体系中浓度分别是０，０．４，２．０，１０．０及２０．０ｍｍｏｌ／Ｌ；铅（ＰｂＡｃ２）在体系中浓度分别是０，０．０８，０．４及２．０ｍｍｏｌ／Ｌ；联合染毒采用２×２析因设计，各取其剂量的最低无作用剂量，３７℃孵育６０ｍｉｎ测定ＬＰＯ水平。结果显示，砷与铅对离体人红细胞膜ＬＰＯ的影响具有联合作用，其作用形式为相加作用。为观察砷与铅对整体动物的影响，我们采用２×２析因设计，分别取ＬＤ５０的１／５剂量以灌胃的方式染毒，砷为２．４ｍｇ／ｋｇ，铅为３０ｍｇ／ｋｇ，连续１０天。结果显示，砷与铅对大鼠血浆ＬＰＯ作用不明显，但引起红细胞超氧化物歧化酶（ＳＯＤ）活性的明显抑制，红细胞谷胱苷肽（ＧＳＨ）含量下降；析因分析表明，砷与铅对大鼠红细胞ＳＯＤ活性抑制具有联合作用，联合作用形式为相加作用     

不稳定心绞痛与急性心肌梗死血脂变化比较

目的：探讨不稳定心绞痛（ＵＡＰ）和急性心肌梗死（ＡＭＩ）之间血脂变化。方法：对１０９例ＵＡＰ和１４３例ＡＭＩ病人血脂值进行统计学处理分析。结果：ＵＡＰ组ＴＧ（１７１．２±１４６．９）ｍｇ／ｄｌ高于ＡＭＩ组（１３６．９±８４）ｍｇ／ｄｌ（Ｐ＜０．０１）及ＴＧ／ＨＤＬ－Ｃ（５．５±６．２）比（４．１±３．３）和ＬＤＬ－Ｃ／ＨＤＬ－Ｃ（４．０±１．９）比（３．６±１．６）高于ＡＭＩ组（两者均Ｐ＜０．０５）。结论：ＵＡＰ病人ＬＤＬ－Ｃ／ＨＤＬ－Ｃ比值增高可能与其血管病变严重性相关     

HCl—NaBH4—K3Fe（CN）6体系气态原子吸收光谱法测定饮料中铅

采用ＶＡ－９０气态原子化装置与ＷＦＸ－１Ｄ原子吸收分光光度计联用测定饮料中铅，采用ＨＣｌ－ＮａＢＨ４－Ｋ３Ｆｅ（ＣＮ）６体系，经Ｌ９（３４）正交试验选择最佳实验条件为：ＮａＢＨ４２０ｇ／Ｌ，Ｋ３Ｆｅ（ＣＮ）６１００ｇ／Ｌ，ＨＣｌ１．５ｍｌ，氩气流量为０．８Ｌ／ｍｉｎ。在０～１００μｇ／Ｌ范围内，相关系数ｒ＝０．９９９６，回收率为９４．１％～１０７．５％，Ｒ·Ｓ·Ｄ％＝３．３～５．２特征浓度和检出限分别为１．２９μｇ／Ｌ／１％和０．０４９μｇ／Ｌ。干扰试验表明，Ｓｎ、Ｈｇ、Ｃｒ、Ｃｕ、Ｍｎ在５００μｇ／Ｌ以下，Ｚｎ、Ａｓ、Ｆｅ、Ｎｉ、Ａｇ在１０００μｇ／Ｌ以下，不干扰测定     

拟除虫菊酯对大鼠脑突触小体谷氨酸摄取的抑制作用

体外研究显示，溴氰菊酯（１ｘ１０￣（－７）～１ｘ１０￣（－４）ｍｏｌ／Ｌ）可使大鼠大脑皮层和海马突触小体￣３Ｈ－ＤＬ－谷氨酸摄取量分别降低７．２％～２１．５％和１０．４％～２５．１％，且存在明显的剂量。效应关系。而氯菊酯却只在高剂量（１ｘ１０￣（－４）ｍｏｌ／Ｌ）方使海马突触小体￣３Ｈ－ＤＬ－谷氨酸摄取明显降低。此外，溴氰菊酯还可降低小脑和纹状体￣３Ｈ－ＤＬ－谷氨酸的摄取，抑制率分别为１６．５％和３１．８％。结果表明，溴氰菊酯和氯菊酯可严重干扰脑组织高亲和性谷氨酸摄取机制的功能，其中以含氰基的溴氰菊酯作用较强，因此在拟除虫菊酯杀虫剂对哺乳动物的中枢兴奋性毒性作用中可能具有重要意义。     

内源性脂质过氧化产物丙二醛对细胞周期抑制的诱导作用

本研究所用细胞为含有野生型ｐ５３的人类大肠癌细胞系（ＲＫＯ）及无遗传学效用ｐ５３的人类肺腺癌细胞系（Ｈ１２９９）。ＲＫＯ和Ｈ１２９９细胞在３７℃、９５％空气、５％ＣＯ２环境中,分别在ＭｅＣｏｙｓ５Ａ和Ｆ１２培养基中培养。分别用丙二醛（ＭＤＡ）（１ｍｍｏｌ／Ｌ）、ＡＤＲ（０．４ｍｏｌ／Ｌ）处理上述细胞,以阿霉素（ＡＤＲ）处理为阳性对照。结果显示,经ＭＤＡ处理ＲＫＯ和Ｈ１２９９细胞２４ｈ,Ｍ１Ｇ－ｄＲ加合物含量分别增加了３倍和６倍。用ＭＤＡ和ＡＤＲ处理ＲＫＯ细胞,Ｇ２Ｍ期细胞的比例随处理时间的增加而…     

微乳液-8-羟基喹啉体系测定Fe(Ⅲ)

研究了 Ｏ／ Ｗ 阴离子微乳液十二烷基硫酸钠（ Ｓ Ｄ Ｓ）／正丁醇（ｎ－ Ｃ４ Ｈ９ Ｏ Ｈ）／正庚烷（ｎ－ Ｇ７ Ｈ１６ ）／ Ｈ２ Ｏ 对 Ｆｅ 与８－ 羟基喹啉（ Ｈ Ｏｘ ）显色体系的增敏增稳作用,实验结果表明其灵敏度为ε４６０ ＝ ６５６×１０３ Ｌ·ｍ ｏｌ－ １ ·ｃｍ － １ ,ε５８０ ＝ ５５９×１０３ Ｌ·ｍ ｏｌ－ １ ·ｃｍ － １ ,与相同含水量的 Ｓ Ｄ Ｓ胶束体系（ε４６０ ＝ ４７２×１０３ Ｌ·ｍ ｏｌ－ １ ·ｃｍ － １ ,ε５８０ ＝ ４０５×１０３ Ｌ·ｍ ｏｌ－ １ ·ｃｍ － １ ）比较,发现其测定灵敏度显著增加,增加百分比分别为３８９％ 、４６９％ ,某些实验条件得以改善。     

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.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.     

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.     

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.     

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.