全氟辛烷磺酸对大鼠兴奋性氨基酸影响

目的 探讨全氟辛烷磺酸(PFOS)与大鼠中枢神经系统兴奋性氨基酸含量关系.方法 将成年Wistar大鼠经口 PFOS染毒.实验组剂量分别为12.5,25,50 mg/kg,对照组给予等体积的2%吐温-80溶液.24 h后高效液相色谱法测定脑组织中谷氨酸、天冬氨酸、γ-氨基丁酸及甘氨酸含量变化.结果 天冬氨酸12.5,50 mg/kg组含量分别为(1.24±0.109),(1.11±0.452)umol/g,与对照组(1.51±0.076)umol/g比较,差异有统计学意义(P<0.05).谷氨酸无明显变化.甘氨酸12.5,25,50mg/kg组含量分别为(0.82±0.201),(1.09±0.215),(1.12±0.395)/umol/g.与对照组(1.54±0.120)umol/g比较.差异均有统计学意义(P<0.05).γ-氨基丁酸12.5,25 mg/kg组含量分别为(1.52±0.187),(1.68±0.188)umol/g,与对照组(2.03±0.370)umol/g比较,差异有统计学意义(P<0.05).结论 低剂量PFOS染毒后中枢神经系统出现先抑制后兴奋的症状可能与兴奋性氨基酸的参与有关.     

全氟辛烷磺酸对小鼠大脑谷氨酸含量和蛋白激酶活性的影响

目的 通过观察全氟辛烷磺酸（PFOS）对雄性小鼠大脑谷氨酸含量、蛋白激酶C（PKC）和蛋白激酶A（PKA）活性的影响及超微结构的改变,探讨PFOS所致神经毒性机制。方法 44只雄性昆明系小鼠按体重分为4组,每组11只。PFOS染毒剂量分别为5、10、20mg／kg,对照组给予同等体积2％吐温．80,连续经口染毒10d。分光光度计法测定小鼠大脑谷氨酸含量,非放射性蛋白激酶检测法测定PKC和PKA活性,透射电镜观察大脑皮质超微结构的损伤。结果 10、20mg／kg染毒组小鼠大脑谷氨酸含量分别为（1．57±0．11）、（1．62±0．16）mmol/g蛋白,与对照组[（1．45±0．13）mmol/g蛋白]相比,差异有统计学意义（F=39．59,P〈0．05）;5、10、20mg／kg染毒组PKC活性分别为（29．05±2．89）、（33．65±3．82）和（34．20±3．16）pmol·min^-1·（mg蛋白）^-1,与对照组[（24．53±2．88）pmol·min^-1·（mg蛋白）^-1]比较,差异有统计学意义（F=7．75,P〈0．05）。5、10、20mg／kg染毒组PKA活性与对照组比较,分别升高了（24．12±3．86）％、（34．02±3．04）％和（33．42±3．71）％,差异有统计学意义（F=26．27,P〈0．01）。但PKC和PKA活性的升高趋势在PFOS剂量为20mg／kg时趋缓。给予小鼠PFOS可对大脑皮质细胞造成细胞核膜凹陷的超微结构损伤。结论 PFOS染毒导致小鼠脑组织谷氨酸含量、PKC和PKA活性升高,并对大脑皮质细胞造成超微结构损伤,可能是PFOS引起神经毒性的机制之一。     

全氟辛烷磺酸对大鼠脑组织氨基酸类神经递质和谷氨酰胺合成酶的影响

目的探讨全氟辛烷磺酸(PFOS)与大鼠中枢神经系统兴奋性氨基酸和谷氨酰胺合成酶(GS酶)的剂量反应关系。方法将20只成年雄性Wister大鼠随机分为4组(对照组、4个染毒组)每组5只。大鼠染毒PFOS(12.5、25、50mg/kg)5天后,对照组给予等体积的2%吐温-80溶液,应用高效液相色谱法测定脑组织氨基酸类神经递质及谷氨酰胺合成酶的改变。结果与对照组比较,大鼠自发活动能力下降;50mg/kg体重组海马谷氨酸含量显著降低,25和50mg/kg体重组皮质谷氨酸含量显著降低;随着染毒剂量的增加海马GS酶活性增加,其中12.5mg/kg剂量组和25mg/kg剂量组明显高于对照组(P<0.05)。结论氨基酸类神经递质含量的改变是PFOS神经毒性的机制之一。     

α-硫辛酸对甲基汞致大鼠脑谷氨酸代谢转运障碍的拮抗作用

[目的]探讨出硫辛酸（alpha—lipoicacid,α-LA）对甲基汞所致大鼠脑谷氨酸代谢转运障碍的拮抗作用。[方法]清洁级Wistar大鼠24只,按体重随机分为4组,分别为对照组,低、高甲基汞染毒组和α-LA干预组,每组6只,雌雄各半。对照组和低、高甲基汞染毒组先皮下注射0．9％氯化钠溶液,α-LA干预组皮下注射35gmol／kgct-LA;2h后,对照组腹腔注射0．9％氯化钠溶液,低、高甲基汞染毒组和α-LA干预组分别腹腔注射氯化甲基汞4、12和12lamol／kg。α-LA预处理隔日1次;染毒组每日1次,每周5次;连续处理4周。最后1次染毒24h后,分离大鼠大脑皮质,制备5％、10％的组织匀浆,测定大脑皮质汞（Hg）、谷氨酸（Glu）、谷氨酰胺（Gin）含量,及谷氨酰胺酶（PAG）、谷氨酰胺合成酶（GS）、Na＋-K＋ATPase、Ca2＋．ATPase活力。[结果]甲基汞高剂量染毒组大鼠脑汞为（17．72±1．36）μg,／g组织、Glu含量为（71．57±10．87）μmol／g白、PAG活力为（31．26±4．38）μmol／（min·g蛋白）,均高于对照组（P〈0．01）;CAn含量及Gs活力分别为（0．155±0．04）μmol／g蛋白及（23．89±3．60）u儋蛋白,Na＋-K＋-ATPase及Ca2＋-ATPase活力分别为（4．03±0．57）μmol／（mg蛋白·h）及（2．21±0．62）μmol／（mgg蛋白·h）,均低于对照组（P〈0．01）;与甲基汞高剂量染毒组比较,α-LA干预组大鼠脑汞含量未见明显变化;Glu含量（63．02±3．33）μmol／g蛋白及PAG活力（26．03±3．88）μmol/（min·g蛋白）均降低（P〈0．01或P〈0．05）,Gin含量（0．20±0．05）μmol／g蛋白、GS活力（34．05士4．23）U／g蛋白、Na＋-K＋-ATPase活力为（5．52±1．16）μmol／（h·mg蛋白）及Ca2＋-ATPase活力为（3．27±0．60）μmol／（h·mg蛋白）,均升高（P〈0．01或P〈0．05）。[结论]a-LA对甲基汞所致大鼠脑谷氨酸代谢紊乱有一定的拮抗作用。     

维生素B6缺乏对大鼠海马脑区氨基酸类和一氧化氮递质系统的影响

目的为探讨维生素B6影响认知功能的可能机制,对缺乏VB6的生长期大鼠海马脑区氨基酸和NO递质系统进行了观察.方法20只Wistar大鼠分为VB6缺乏组和对照组,测定海马脑区氨基酸和NO含量以及海马突触小体谷氨酸摄取量.结果VB6缺乏组大鼠的红细胞天门冬氨酸氨基转移酶(EAST)活性系数为2.06±0.33,超过1.8,而对照组的为1.19±0.17,(P＜0.05),表明机体已处于VB6缺乏状态.VB6缺乏组与对照组比较,大鼠海马脑区谷氨酸含量升高[(9.61±0.61)μmol·g-1vs.(8.36±0.54)μrmol·g-1,P＜0.05],而甘氨酸则降低[(3.82±0.53)μmol·g-1vs.(4.65±0.53)μmol·g-1,P＜0.05],兴奋性氨基酸与抑制性氨基酸比例失调;同时海马突触小体对谷氨酸的摄取能力降低[(33 160±6 929)CPM·mg pro-1vs.(55 849±8 365)CPM·mg pro-1,P＜0.05];此外,精氨酸含量也升高[(0.15±0.01)μmol·g-1vs.(0.12±0.01)μmol·g-1,P＜0.05],NO含量则降低[(1.17±0.13)mg·g-1vs.(1.33±0.14)mg·g-1,P＜0.05].结论VB6可通过参与调节神经递质合成代谢来影响学习记忆能力.     

兴奋性氨基酸与1,2-二氯乙烷急性中毒性脑病关系的探讨

目的　探讨兴奋性氨基酸 (EAAs)与 1 ,2 二氯乙烷 (1 ,2 DCE)急性中毒性脑病的关系。方法　将SD大鼠随机分为 7组 :对照组、3个染毒组 (5 .0、1 0 .0、2 0 .0g/m31 ,2 DCE)和 3个时间组(1 0 .0g/m31 ,2 DCE染毒后 2、4、6h) ;连续静式吸入染毒 1 2h ;干湿重法测定大鼠脑皮质和髓质含水量 ;高效液相色谱法 (HPLC)检测脑组织中谷氨酸 (Glu)、天冬氨酸 (Asp)、甘氨酸 (Gly)及γ 氨基丁酸(GABA)含量的变化。结果　 (1 )大鼠脑皮质和髓质含水量 :不同剂量染毒组大鼠脑皮质含水量分别为 76 .1 0 %± 1 .41 %、76 .45 %± 0 .75 %、79.95 %± 1 .45 % ,均高于对照组 (74.2 2 %± 1 .77% ) ,差异有显著性 (P <0 .0 5 ,P <0 .0 1 ) ;髓质含水量仅 2 0 .0g/m3组 (71 .77%± 3 .0 7% )有明显升高 ,差异有显著性(P <0 .0 5)。染毒后 2、4、6h脑皮质含水量分别为 79.36 %± 2 .1 0 %、79.48%± 1 .2 1 %、80 .64 %±1 .93 % ,均高于 1 0 .0g/m3即刻组 ,差异有显著性 (P <0 .0 5)。 (2 ) 4种氨基酸递质含量 :不同剂量染毒组Asp含量分别为 (4.83± 0 .35)、(7.1 7± 0 .40 )、(1 0 .52± 0 .39) μmol/g ;Glu含量分别为 (2 3 .86± 0 .62 )、(31 .2 1± 2 .50 )、(2 8.2 3± 1 .58) μmol/g;Gly含量分别为 (5 .59±     

苯并[a]芘对大鼠学习记忆和海马氨基酸类神经递质含量的影响

目的 研究苯并[a]芘(B[a]P)对大鼠学习记忆和海马氨基酸类神经递质含量的影响.方法 健康雄性SD大鼠32只,按脑室插管后的体重随机分为4组:溶剂对照组及2.5、5.0、10.0mmol/L B[a]P染毒组.以不同浓度(2.5、5.0、10.0 mmol/L)的B[a]P橄榄油溶液各10μl侧脑室注射染毒大鼠,溶剂对照组注射等体积的橄榄油.用Morris水迷宫测试大鼠的学习记忆能力.高效液相色谱一荧光检测器法测定海马氨基酸类神经递质的含量.结果 与对照组相比,B[a]P染毒组大鼠学习记忆能力明显下降,差异有统计学意义(P<0.01);而且染毒组大鼠海马谷氨酸(Gh)含量明显降低,差异有统计学意义(P<0.01);而天冬氨酸(Asp)、甘氨酸(Gly)、γ-y.氨基丁酸(GABA)含量在各组未见明显变化.结论 B[a]P能使大鼠空间学习记忆能力降低,这可能与海马兴奋性氨基酸含量的降低有关.     

鱼藤酮对大鼠纹状体谷氨酸-谷氨酰胺环路的影响

[目的]观察鱼藤酮（rotenone）对大鼠纹状体谷氨酸一谷氨酰胺环路代谢的影响。[方法]将24只SD大鼠随机分为正常对照组、溶剂对照组、2.0mg／kg和4.0mg／ks鱼藤酮染毒组。采用高效液相色谱法（HPLC）检测鱼藤酮染毒大鼠纹状体谷氨酸（glutamate,Glu）和谷氨酰胺（glutamine,Gin）含量;使用逆转录聚合酶链式反应（RT-PCR）法观察谷氨酰胺合成酶（glutamine synthetase,GS）基因表达的变化;采用分光光度法检测谷氨酰胺酶（phosphate activated glutaminase,PAG）与GS活性。[结果]与正常对照组比较,4.0mg／kg染毒组大鼠纹状体Glu含量明显升高（P〈0.01）,而Gin含量明显降低（P〈0.01）;4.0mg／kg染毒组GSmRNA表达明显增强（P〈0.05）;4.0mg／kg染毒组Gs活性却明显降低,PAG活性明显升高（P〈0.01）。[结论]鱼藤酮诱导大鼠纹状体Glu含量明显升高,可能是导致中脑神经元兴奋性损伤的的主要原因之一。     

乐果对大鼠皮层神经元氧化损伤及兴奋性氨基酸递质含量的影响

目的 观察乐果染毒对原代培养的大鼠皮层神经元的的毒性作用及损伤机制.方法 体外原代培养SD大鼠皮层神经元6 d后,加入终浓度为1、5、10、50、100 μmol/L的乐果,于染毒后48 h收获细胞,取匀浆上清液用于氧化损伤及细胞内兴奋性氨基酸递质的测定,流式细胞术检测细胞凋亡.结果 染毒48 h后,乐果浓度在5、10、50、100 μmol/L时,超氧化物歧化酶(SOD)活力[(1.04±0.02)、(0.99±0.02)、(0.96±0.02)、(0.91±0.02)U/mg pro]即明显降低,谷胱甘肽(GSH)含量[(219.35±6.79)、(205.6±6.29)、(194.06±2.63)、(93.68±7.56)mg/g pro]明显降低,丙二醛(MDA)含量[(21.22±0.29)、(24.01±0.34)、(27.15±1.02)、(32.91±1.39)nmol/mg pro]明显升高,与对照组比较,差异均有统计学意义(P<0.01);10、50、100 μmol/L剂量组天冬氨酸含量明显升高,1、5、10、50、100μmol/L剂量组谷氨酸含鼍明显升高,与对照组比较,差异均有统计学意义(P<0.01);1、10、100 μmol/L染毒组乐果对神经无细胞凋亡影响明显.乐果染毒后,神经元内MDA含量与兴奋性氨基酸(天冬氨酸、谷氨酸)含量呈正相关,相关系数分别为0.937和0.759;而与GSH含量呈负相关,相关系数分别为-0.868和-0.801,有统计学意义(P<0.01).结论 乐果可引起神经元氧化损伤及兴奋性氨基酸递质含量变化,共同参与神经元的凋亡过程.     

正常成人总体蛋白质更新率及血浆甘氨酸动力学参数的测定

实验以~(15)N-甘氨酸为示踪剂,一次静脉内注射给药后,分别收集一定时间内血浆样品和尿样。血浆样品经一系列处理后,用气相层析-质谱联用仪(GC-MS)分析血浆中~(15)N-甘氨酸的丰度衰减情况,尿样经处理后,用同位素比值质谱计测定其中~(15)N丰度,并分别按不同的数学模型,计算出一系列动力学参数。实验测定了12例正常成人的总体蛋白质更新率为4.20±0.23(蛋白质g·d~(-1)·kg~(-1),合成速率为3.29±0.26(蛋白质g·d~(-1)·kg~(-1)),分解速率为3.06±0.25(蛋白质g·d~(-1)·kg~(-1)),其中10例的血浆甘氨酸更新率为3.02±0.46/h,血浆库容量为98.358±9.60μmol/kg,血浆甘氨酸流量为289.325±26.23(μmol·kg~(-1)·h~(-1))。     

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.     

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.     

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.