铅对大鼠海马一氧化氮合酶基因表达的影响

目的　探讨铅对海马一氧化氮合酶 (nNOS)基因的mRNA和蛋白表达的影响。方法　 1 2只大鼠饮用含 0 2 %醋酸铅 (PbAc)水 3个月后 ,作为铅染毒组进行实验。用ABC免疫组织化学和半定量逆转录 -聚合酶链式反应 (RT PCR)方法测定大鼠海马nNOS阳性神经元数量和nNOSmRNA含量的变化。结果　铅染毒组大鼠海马CA1 区、齿状回nNOS阳性神经元数目分别为 4 6 6 7± 9 0 4和 30 5 3± 7 0 8,较对照组的6 0 6 7± 1 3 4 8和 5 7 0 7± 1 1 1 4明显减少 ,差异有显著性 (P <0 0 5 ) ;铅染毒组大鼠海马CA3 区nNOS阳性神经元数目与对照组比较 ,差异无显著性 (P >0 0 5 ) ;铅染毒组大鼠海马nNOSmRNA含量 (0 0 71± 0 0 2 5 )比对照组 (0 4 5 4± 0 0 4 5 )显著减少 (P <0 0 1 )。结论　铅对大鼠海马各区nNOS阳性神经元数和mRNA表达降低 ,可能是铅干扰学习记忆功能的机制之一     

牛磺酸对染铅大鼠学习记忆影响的改善作用

目的　探讨牛磺酸 (Tau)对染铅大鼠学习记忆影响的改善作用。方法　 4 0只Wistar大鼠随机均分为 5组 :空白对照组、铅染毒组 (40mg·kg-1·d-1醋酸铅灌胃 4周 )、Tau 10 0mg组 (10 0mg·kg-1·d-1)、Tau 4 0 0mg组 (40 0mg·kg-1·d-1)、Tau 80 0mg组 (80 0mg·kg-1·d-1) :染铅后继续灌胃 4周。第 5～ 8周每周用方位水迷宫试验测试学习记忆能力 1次。第 8周末处死动物 ,测定全血铅和脑丙二醛 (MDA)、超氧化物歧化酶 (SOD)、谷胱甘肽 (GSH)、谷胱甘肽过氧化物酶 (GSH PX)、一氧化氮合成酶 (NOS)、乙酰胆碱酯酶 (AChE)等指标水平。结果　 (1)水迷宫实验中 ,各Tau治疗组大鼠逃逸时间均少于铅染毒组 ,其中Tau 80 0mg组在第 6、7、8周实验、Tau 4 0 0mg组在第 6周的实验中 ,逃逸时间与铅染毒组比较 ,差异有显著性 (P <0 .0 5 )。 (2 )Tau 10 0、4 0 0mg组大鼠血铅水平分别为 (5 10 .90±5 7.5 6 )、(485 .4 0± 98.85 ) μg/L ,与铅染毒组比较 ,差异有显著性 (P <0 .0 5 )。 (3)Tau 80 0、4 0 0mg组大鼠脑MDA水平、SOD活力、NOS活力、AChE活力以及Tau 80 0mg组GSH含量、GSH PX活力与铅染毒组比较 ,差异有显著性 (P <0 .0 5或P <0 .0 1)。结论　Tau可改善染铅大鼠的学习记忆能力 ,对铅染毒大鼠的大脑有一定的     

睡眠剥夺对大鼠学习能力的影响及机制初步研究

目的 :探讨睡眠剥夺对大鼠学习能力的影响。方法 :采用小平台水环境法建立睡眠剥夺模型 ,以正常组和大平台组作为对照 ,检测大鼠海马一氧化氮 (NO)及一氧化氮合酶 (NOS)含量变化 ,并以Y型迷宫测量大鼠学习能力。结果 :(1)睡眠剥夺 1d、3d、5d组海马NO含量分别为(5 .2 6± 1.34)、(7.6 3± 1.86 )、(7.96± 2 .15 ) μmol·mgprot- 1,NOS含量分别为 (2 .4 6± 0 .6 8)、(2 .97± 0 .73)、(3.18± 0 .82 )U·mgprot- 1,分别高于正常对照组〔(3.4 9± 1.18) μmol·mgprot- 1、(1.32±0 .6 7)U·mgprot- 1〕和大平台组〔(4.35± 1.0 9) μmol·mgprot- 1、(1.89± 0 .6 2 )U·mgprot- 1(P <0 .0 1,0 .0 5 )〕 ;后两组比较无显著性差异。 (2 )睡眠剥夺 3d、5d组迷宫正确反应所需电击次数分别为 (2 8.1± 5 .2 )、(41.4± 7.9)次 ,所需时间为 (136 .4± 2 1.7)、(186 .7± 2 9.8)s ,高于正常对照组的 (2 2 .9± 4 .7)次 ,(10 9.6± 16 .5 )s和大平台组的 (16 .8± 3.5 )次 ,(82 .9± 13.2 )s(P <0 .0 1)。 (3)NO含量与迷宫正确反应所需电击次数及时间有显著正相关关系 (P <0 .0 1)。结论 :睡眠剥夺导致的大鼠学习能力下降可能与NO/NOS的神经毒性作用有关。     

慢性铅接触对大鼠学习和记忆的影响

目的　观察长期低铅暴露对大鼠学习及记忆功能的影响并探讨其可能的机理。方法　选择刚断乳的Wistar大鼠 2 0只 ,随机分为实验组 (n =13)和对照组 (n =7) ,分别饮用 0 0 5%醋酸铅水溶液和蒸馏水。饲养10 0～ 110d后用Y迷宫检测分辨学习及记忆能力 ,然后取血和脑行铅、钙含量的测定。结果　慢性低铅接触后大鼠的学习能力 (2 0 2 3± 5 52 )和记忆保持百分数 (6 4 17± 9 92 )均显著低于正常对照组 (分别为 13 86± 1 95,86 6 7± 5 16 ) ,(P <0 0 1,t =2 95,2 98)。染铅大鼠血铅 (0 399± 0 82 ) μg/ml、脑铅 (2 189± 0 818) μg/g湿重 ,浓度均显著高于对照组 (0 0 4 93± 0 0 12 μg/ml,0 6 9± 0 0 8μg/g湿重 ) ,(P <0 0 1,t =10 94和 4 4 1) ;而两组间血钙和脑钙差异无显著性。学习记忆能力与血铅、脑铅含量有关。结论　慢性铅接触可损害大鼠的学习记忆功能 ,铅通过血脑屏障沉积于大脑并与钙离子拮抗 ,干扰了细胞内的钙稳态 ,是造成脑损害的机制之一。     

不同价态锰对神经母细胞瘤细胞的氧化损伤作用

目的　探讨不同价态、不同浓度锰引起神经细胞的脂质过氧化对细胞的损伤作用。方法　分别用 0 ,0 2 5 ,0 5 0 ,0 75mmol/L二价锰、三价锰对神经母细胞瘤细胞 (SH SY5Y)染毒 2 4h ,观察测定细胞超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH Px)、丙二醛 (MDA)、GSH Px/MDA及细胞膜脂荧光各向异性的变化。结果　二价锰、三价锰染毒各低、中、高剂量组细胞SOD活力 [(5 2 2 1 2± 5 7 74 ) ,(4 98 38± 37 2 9) ,(4 6 4 86± 2 4 0 9)和 (4 99 79± 30 86 ) ,(4 77 2 3± 6 1 6 6 ) ,(4 35 95± 74 0 4 )NU/mg蛋白 ]与对照组[(86 1 2 4± 35 74 )NU/mg蛋白 ]比较明显降低 ,差异有显著性 (P <0 0 5 ) ;GSH Px活力 [(1 9 0 4± 5 1 6 ) ,(1 7 74± 5 91 ) ,(1 5 99± 5 6 2 )和 (1 6 5 8± 6 1 9) ,(1 5 79± 7 2 9) ,(1 4 2 3± 5 2 0 )活力单位 ]均较对照组[(2 9 2 3± 7 83)活力单位 ]降低 ,差异有非常显著性 (P <0 0 1 ) ;GSH Px/MDA较对照组降低 ,差异有显著性 (P <0 0 5 ) ,而MDA和细胞膜脂荧光各向异性有所升高 (P <0 0 5 ) ;相同染毒剂量情况下 ,三价锰组上述指标的变化比二价锰组明显。结论　锰通过抑制SOD、GSH Px活力 ,降低细胞抗氧化能力 ,造成细胞膜功能的损伤。三     

铅对大鼠海马生长抑素神经元及其基因表达的影响

研究铅对大鼠海马不同亚区生长抑素 (SS)神经元及其基因表达的影响 ,Wistar大鼠采用饮水加2 0 0 0 μg ml醋酸铅 (PbAc)方法染毒 3个月后 ,用原子吸收分光光度法测定血液和海马铅的含量 ,并通过免疫组化和原位杂交技术检测海马SS和SSmRNA阳性神经元蛋白和基因表达。结果显示 ,染铅组大鼠血液和海马铅含量分别为 (1 30 0 5± 1 4 2 1 )mg L和 (1 0 1 1 62± 59 54)ng L ,较对照组的 (5 54± 0 76)mg L和 (1 81 98±47 2 7)ng L明显增高 ,差异有显著性 (P <0 0 5) ;染铅组大鼠海马CA1 区SS和SSmRNA阳性神经元数目分别为 (2 3 2 7± 4 58)和 (37 60± 9 69) ,较对照组的 (40 38± 7 61 )和 (53 48± 1 0 2 2 )明显减少 ,差异有非常显著性(P <0 0 1 ) ;染铅组大鼠海马CA3 区SS和SSmRNA阳性神经元数目为 (1 2 1 6± 3 40 )和 (1 6 1 8± 6 1 9) ,较对照组的 (1 7 68± 5 86)和 (2 5 93± 7 47)明显减少 ,差异有显著性 (P <0 0 5)。提示染铅后大鼠海马各区SS阳性神经元的蛋白、基因表达能力是降低的     

溴氰菊酯对大鼠神经细胞胞内游离钙浓度及凋亡的影响

目的　观察溴氰菊酯 (DM )对神经细胞游离钙浓度 ([Ca2 + ]i)及凋亡的影响。方法　Wistar大鼠随机分为对照组与 3个染毒组 ,染毒组腹腔注射 1 2 .5mg/kg的DM ;以Fura 2 /AM为荧光指示剂 ,RF 530 1PC荧光分光光度计测定染毒后 5、2 4、48h后大鼠神经细胞 [Ca2 + ]i浓度的变化 ;FACS42 0型流式细胞仪测定细胞凋亡率。结果　PM染毒 5、2 4、48h组大鼠海马及皮层细胞 [Ca2 + ]i分别为 :5h组海马 :(389.94± 43 .64)nmol/L、皮层 :(449.33± 2 3 .2 3)nmol/L ;2 4h组海马 :(340 .47±32 .36)nmol/L、皮层 :(31 1 .62± 2 5 .48)nmol/L ;48h组海马 (2 87.1 3± 2 4 .2 9)nmol/L、皮层 :(346 .55±36 .87)nmol/L ,均高于对照组 [海马 :(2 0 3 .2 4± 1 8.53)nmol/L、皮层 :(2 2 6 .85± 1 4 .81 )nmol/L] ,差异有显著性 (P <0 .0 1 )。染毒 48h组大鼠此二项指标值较 5h组明显下降 ,差异有显著性 (P <0 .0 5)。染毒 2 4、48h组大鼠神经细胞凋亡率 [海马 :(8.45± 1 .0 2 ) %、(9.44± 1 .1 4 ) % ,皮层 :(7.90± 0 .49) %、(8.0 1± 0 .87) % ]均明显高于对照组 [海马 :(2 .97± 0 .36) %、皮层 :(3 .50± 0 .48) % ] ,差异有显著性 (P<0 .0 1 ) ,且有时间 反应关系 (r=0 .940、0 .893)。结论　DM可影响大鼠神     

溴氰菊酯对原代培养大鼠星形胶质细胞存活率和胞内游离钙浓度的影响

目的　观察溴氰菊酯 (DM)对原代培养大鼠神经星形胶质细胞存活率及胞内游离钙离子浓度 ([Ca2 + ]i)的影响。方法　以锥虫蓝染料排斥试验检测细胞染DM后存活率的变化 ;以Fura 2 /AM为荧光指示剂 ,RF 5 30 1PC荧光分光光度计测定细胞内 [Ca2 + ]i的变化。结果　 1× 10 -5mol/L组染毒DM 72h后细胞存活率下降为 91.9% ,与对照组的差异有显著性 (P <0 .0 5 ) ,1× 10 -4mol/L组DM染毒4、12、4 8、72h后细胞存活率分别为 89.0 %、84 .8%、81.2 %和 79.2 % ,差异有显著性 (P <0 .0 1) ;1× 10 -7、1× 10 -6、1× 10 -5mol/L组DM染毒 5min后胞内 [Ca2 + ]i分别上升至 (45 1.4± 4 2 .3)、(5 36 .9± 4 7.5 )、(870 .9± 10 0 .5 )nmol/L ,与染毒前及对照组比 ,差异有显著性 (P <0 .0 1)。以后各染毒组胞内 [Ca2 + ]i逐渐下降 ,15min时 1× 10 -8、1× 10 -7、1× 10 -6、1× 10 -5mol/L染毒组胞内 [Ca2 + ]i分别降至 (12 4 .3± 6 .0 )、(131.3± 19.1)、(118.9± 1.4 )、(136 .6± 3.8)nmol/L ,与染毒前及对照组比差异均有显著性 (P <0 .0 5或P <0 .0 1)。结论　DM在体外可降低神经胶质细胞的存活率并短时升高胞内 [Ca2 + ]i。     

哺乳期母鼠接触溴氰菊酯对其仔鼠神经行为发育的影响

目的探讨哺乳期母鼠接触溴氰菊酯(DM)对发育期仔鼠脑一氧化氮合酶(NOS)活力及神经行为发育的影响。方法妊娠大鼠随机分为对照组和2个染毒组,每组6只。染毒剂量分别为3．35和6．70 mg/kg,每只母鼠自产后1～19 d,隔日1次,经口染毒DM；对照组予等量玉米油。观察DM对出生后5、10和21 d仔鼠脑NOS活力及30d仔鼠学习、记忆能力的影响。结果2个染毒组仔鼠哺乳存活率(81．80%、78．60%)均明显降低于对照组(96．70%),差异有统计学意义(P＜0．01)；6．70 mg/kg染毒组10、21 d仔鼠体重[(16．62±2．28)、(31．34±6．94)g]明显低于对照组[(18．81±2．01)、(36．21±7．01)g],差异有统计学意义(P＜0．05)；6．70mg/kg染毒组仔鼠延迟时间为(3．05±1．20)s,被动逃避反应阳性率为21．5%；3．35 mg/kg染毒组被动逃避反应阳性率为22．5%,与对照组比较,差异均有统计学意义(P＜0．05)。旷场实验中,2个染毒组仔鼠行进格子数均明显降低,与对照组的差异均有统计学意义(P＜0．05)；产后5至21 d仔鼠脑NOS活力呈发育性增高趋势；6．70mg/kg染毒组出生后5 d仔鼠脑NOS活力[(0．60±0．07)U·mg pro~(-1)·h~(-1)]明显低于对照组,差异有统计学意义(P＜0．05)结论哺乳期母鼠接触DM可导致仔鼠神经行为发育迟缓,并伴有NOS活力下降。     

热性惊厥对大鼠情感行为及学习记忆的影响

【目的】　探讨热性惊厥对大鼠情感行为及学习记忆能力的影响。　【方法】　 3 6只雄性SD (Spraque Dawley)大鼠随机分为热性惊厥组 (febrileseizuresgroup ,FS) ,发热对照组 (febrilecontrolgroup ,FG)及正常对照组 (nor malcontrolgroup ,NG)。观察各组大鼠在旷场试验 (openfieldtest ,OFT)、避暗试验 (passiveavoidancetest,PAT)以及在Morris水迷宫 (Morriswatermaze ,MWM )试验中情感行为及学习记忆能力的改变。　【结果】　FS组大鼠与NG、FG组相比 :在OFT中穿格得分分值 ( 3 7.48± 7.0 9)降低 ,后肢性站立的次数 ( 12 .11± 4.41)减少 ,排出粪便粒数 ( 10 .62±2 .3 2 )增多 ,差异有非常显著性 (P <0 .0 1) ;在PAT中 ,FS组大鼠犯错次数 ( 4 .0 2± 1.2 9)增加 ,且记忆潜伏期 [( 169.71± 10 3 .2 2 )秒 ]缩短 ,差异有非常显著性 (P <0 .0 1) ;在Morris水迷宫试验中 ,FS组大鼠搜寻站台的逃逸潜伏期明显延长 ,差异有非常显著性 (P <0 .0 1)。　【结论】　多次热性惊厥发作可使大鼠的情感行为和学习记忆能力受损     

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 human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

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.     

The risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.