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     

鱼藤酮对SH-SY5Y细胞线粒体膜电位的影响

[目的]探讨环境毒素鱼藤酮对人多巴胺能神经母细胞瘤(SH-SY5Y)细胞线粒体膜电位的影响以及线粒体ATP敏感性钾通道(MitochondrialATP-sensitivepotassiumchannel,mKATPchannel)在其中的作用。[方法]先用0、5、20、100nmol/L浓度的鱼藤酮单独处理SH-SY5Y细胞,观察鱼藤酮与线粒体膜电位下降的量效关系;然后在此4组中分别按加和不加mKATP通道抑制剂5-羟葵酸(5-Hydroxydecanoate,5-HD)0.5mmol/L和(或)激活剂二氮嗪(Diazoxide,DZX)1.0mmol/L与不同浓度鱼藤酮共同作用,观察细胞线粒体膜电位的变化。细胞线粒体膜电位的检测采用罗丹明绿色荧光负载、流式细胞仪测量荧光强度的方法。[结果]5、20和100nmol/L鱼藤酮作用24h分别导致SH-SY5Y细胞线粒体膜电位下降至对照组的91.76%、71.21%和49.65%,膜电位下降程度与鱼藤酮剂量相关;DZX单独作用使线粒体膜电位下降了13.45%,DZX与5和20nmol/L鱼藤酮共同作用分别下降至对照组的75.32%和66.06%,比同浓度鱼藤酮单独作用更加明显;5-HD可抵消DZX的上述作用,5-HD与5nmol/L鱼藤酮共同作用时可减轻鱼藤酮引起的细胞膜电位下降。[结论]鱼藤酮可以引起SH-SY5Y细胞线粒体膜电位下降;小剂量鱼藤酮(5和20nmol/L)能开放mKATP通道,该作用可被5-HD逆转;与DZX相比,小剂量鱼藤酮只能激活某一类型的mKATP通道,这是它导致线粒体膜电位下降的机制之一。大剂量鱼藤酮降低线粒体膜电位的机制中mKATP通道的作用较小。     

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     

三氯乙烯对角质形成细胞线粒体功能和形态的影响

目的探讨三氯乙烯（TCE）对皮肤细胞的毒性机制。方法以不同浓度（0．125、0．500和2．000mmol／L）TCE处理体外分离培养的正常人角质形成细胞（KC），同时设培养基对照组和体积分数为1％的丙酮对照组，然后：（1）分别进行四甲基偶氮噻唑蓝（MTT）试验和ATP酶活力测定来检测细胞毒性和线粒体的代谢变化；（2）采用罗丹明123染色方法，借助流式细胞仪检测线粒体膜电位变化情况；（3）通过透射电子显微镜观察线粒体形态学的改变。结果TCE染毒后，细胞活力随着时间延长和剂量的增加而减小，线粒体酶活力抑制率增加，ATP酶活力减小；线粒体膜电位水平从染毒开始到8h迅速下降2．000mmol／LTCE染毒8h后Rh123荧光强度（8．20±0．66）与对照组（18．73±0．45）相比，差异有统计学意义（P〈0．01）；8h以后则变化不大，12和24h Rh123荧光强度与8h组比较，差异无统计学意义（P〉0．05），线粒体膜电位随染毒剂量的增加呈明显的剂量-效应关系。电镜下可见，TCE处理组线粒体出现肿胀，空泡变性，基质减少，部分嵴消失，对照组线粒体结构完整，基质分布均匀，可见线粒体嵴。结论TCE可以导致KC线粒体功能和形态发生明显改变，这些变化在TCE诱导的KC毒性中具有重要的意义。     

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。     

葡多酚对胸腺细胞凋亡和线粒体膜电位的影响

目的　观察葡多酚 (GPC)对氧化损伤引发的胸腺细胞凋亡和线粒体膜电位的影响。方法　在体外培养的胸腺细胞中加入不同浓度的GPC和培养液中浓度为 12 5 μmol L的H2 O2 ,共同培养 2h ,采用流式细胞术检测细胞凋亡和线粒体膜电位水平。结果　氧化损伤组细胞凋亡率为 (2 9 5 3± 3 8) % ,线粒体膜电位为 2 7 2 4± 2 2 (D值 ) ,5 0mg LGPC保护组则分别为 (8 6 1± 1 2 ) %和 87 5 5± 4 7(D值 ) ,两组间的差异均有显著性 (P <0 0 5 )。结论　GPC可有效抑制氧自由基引发的胸腺细胞凋亡和线粒体膜电位的下降 ,对胸腺细胞的氧化损伤有良好防护作用     

锰对不同月龄大鼠脑纹状体细胞线粒体功能的影响

[目的 ]观测不同价态的锰化合物 (包括二价锰和三价锰 )对大鼠脑组织纹状体部位细胞线粒体功能的影响及不同年龄的大鼠对锰化合物毒性的易感性差异。 [方法 ]分别选用 4个月和 1 8个月龄的Wistar大鼠作为研究对象 ,将大鼠分成不同的月龄组 ,每组又分成对照组和两个锰化合物组 ,腹腔注射染毒 (剂量按 6mg/kg)一个月后宰杀 ,提取动物脑组织纹状体部位细胞线粒体 ,测定线粒体复酶复合体 [complexⅡ及complex (Ⅰ +Ⅲ ) ]活性作为判断线粒体功能的指标 ,并同时观察染毒期间动物体重的变化。 [结果 ]不同鼠龄组中 ,锰化合物组线粒体功能均低于正常组。 1 8月龄和 4月龄大鼠complex (Ⅰ +Ⅲ )活性分别为 :正常组 (2 35± 1 0 3)、(2 66±0 1 1 )nmol/ (min·μg) ;二价锰组 (1 86± 1 0 8)、(2 0 4±0 1 2 )nmol/ (min·μg) ;三价锰组 (1 99± 1 0 1 )、(2 0 9± 0 1 6)nmol/ (min·μg) ;1 8月龄和 4月龄大鼠complexⅡ活性分别为 :正常组(2 58 70± 9 86)、(30 4 64± 2 0 1 8)nmol/ (min·μg) ;二价锰组 (2 0 8 45± 1 2 71 )、(2 4 7 0 0± 1 9 52 )nmol/ (min·μg) ;三价锰组(2 2 5 1 7±7 67)、(2 57 87±1 6 2 8)nmol/ (min·μg) ,且随着年龄的增高 ,对毒物的易感性也增加 ;并且观察     

银杏叶提取物对三氯乙烯所致的角质形成细胞线粒体膜电位变化的影响

目的研究三氯乙烯(TCE)对角质形成细胞(KC)线粒体膜电位的影响以及银杏叶提取物(GBE)的保护作用,为预防三氯乙烯皮肤损害提供理论依据。方法体外培养的人角质形成细胞以不同浓度TCE处理8h,GBE保护实验则以不同浓度GBE预处理2h后再进行TCE染毒,采用罗丹明123(Rh123)和碘化丙啶(PI)双染色方法,通过流式细胞仪检测线粒体膜电位的变化情况。结果空白对照组Rh123荧光强度为18.73±0.45,正常和早期凋亡细胞分别占(77.10±2.08)%和(12.33±1.39)%;2.0mmol/LTCE染毒组Rh123荧光强度下降到8.20±0.66(与空白对照相比,P<0.01),正常和早期凋亡细胞比例分别为(11.90±0.56)%和(65.33±1.45)%(与空白对照相比,均P<0.01)。10mg/L的GBE预处理对2.0mmol/LTCE所致的线粒体膜电位下降即显示有保护作用,Rh123荧光强度为13.80±0.92,正常细胞占(40.90±2.10)%,早期凋亡细胞占(32.10±1.25)%(与2.0mmol/LTCE染毒组相比差异有统计学意义,P<0.01)。随着GBE浓度的增大,保护作用渐强,100mg/L的GBE达到完全的保护作用,上述3项指标分别为18.57±0.57,(76.57±2.67)%和(11.63±1.07)%(与2.0mmol/LTCE染毒组相比,P<0.01,而与空白对照组相比差异均无统计学意义)。结论TCE可以剂量依赖性地诱导KC线粒体膜电位的下降,使细胞进入凋亡状态;GBE预处理能有效预防TCE所致的线粒体膜电位的下降,并可降低KC凋亡。研究结果提示GBE可能用作预防三氯乙烯皮肤损伤的有效保护剂。     

鱼藤酮对PC12细胞的毒性作用

目的 研究鱼藤酮对PC12细胞的毒性作用及其机制.方法 分别用0.1、0.5、1.0μmol/L的鱼藤酮染毒PC12细胞72 h,对照组加入相同剂量的DMS0,采用四甲基偶氮唑盐（MT T）比色法检测细胞活力,借助流式细胞仪检测各浓度下细胞的凋亡率和线粒体膜电位的变化.结果 0.1、0.5、1.0μmol/L鱼藤酮作用于PC12细胞72 h时,细胞活力随染毒浓度的增加而降低.细胞虽未发生明显的凋亡,但处于G1期细胞随染毒浓度增加而增多,G2/S期细胞相对减少,说明鱼藤酮抑制细胞增殖明显,线粒体膜电位降低显著.结论 鱼藤酮在小剂量长时间的持续作用时,启动了细胞凋亡,表现为对PC12细胞的线粒体膜电位的降低.     

锰的离子价态对大鼠心肌线粒体膜电位的影响

[目的]通过实验观察染锰后大鼠心肌线粒体膜电位(ΔΨM)的变化,探讨不同价态锰在不同剂量时,对心肌线粒体的毒作用及其强度。[方法]Wistar4月龄大鼠,断头处死,提取心肌线粒体,分别用Mn2+和Mn3+(终浓度为50、100、200、400μmol/L)染毒10min后,加入含罗丹明(Rhodamin123)的反应缓冲液中,用单波长荧光分光光度计测定在激发波长503nm、发射波长527nm条件下,3min内样品罗丹明荧光值的改变,代表ΔΨM的变化。[结果]Mn2+各染毒剂量组与对照组比较,ΔΨM下降,且差异有显著性(P<0.05);各染毒剂量组之间ΔΨM差异无显著性。Mn3+各染毒剂量组ΔΨM明显低于对照组,且差异有显著性(P<0.05)。各染锰组ΔΨM随浓度的增加而降低,组间相比差异有显著性(P<0.05)。经回归分析Mn3+、Mn2+对ΔΨM影响的b值95%可信区间分别为(-0.0493,-0.0953)和(-0.0047,-0.0479),差异也有显著性(P<0.05)。[结论]不同价态的锰均可使心肌ΔΨM降低,产生心肌毒性;Mn3+对心肌线粒体的毒性大于Mn2+,其机制有待进一步研究。     

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.     

Die sogenannte Vinylchlorid-Krankheit—eine berufsbedingte Systemsklerose?

Zusammenfassung Es wurden 13 Arbeiter untersucht, die zwischen 1 3/4 und 18 Jahren in einem PVC-herstellenden Betrieb beschäftigt waren. 8 von ihnen wiesen sklerodermieartige Hautveränderungen (Abb. 2) auf, die histologisch charakterisiert sind durch Verbreiterung und Homogenisierung der kollagenen Faserbündel (Abb. 3 u. 4) sowie Fragmentation und Rarefizierung der elastischen Fasern (Abb. 5). Bei 7 Patienten bestanden trommelschlegelartige Auftreibungen einzelner Fingerendphalangen (Abb. 1). 11 Patienten zeigten Durchblutungsstörungen der Extremitäten (4 von diesen ein Raynaud-Syndrom) und 6 Patienten Acroosteolysen einzelner Fingerendphalangen (Abb. 6, Tabellen 1–3).Darüber hinaus bestand bei allen Patienten eine Thrombocytopenie, bei 12 Patienten eine Splenomegalie, bei 11 Patienten eine Einschränkung der Leberfunktion (erhöhte BSP-Retention). An der Leber ließ sich histologisch bei den 5 laparoskopierten Patienten eine deutliche Fibrosierung der Portalfelder nachweisen. Bei 4 Patienten bestanden Oesophagusvaricen (Tabellen 4 u. 5). 8 Patienten zeigten eine Partialinsuffizienz mit Hinweisen für vorwiegend restriktive Veränderungen.Die hier beschriebenen Veränderungen gehen weit über das bisher bekannte Acroosteolysesyndrom hinaus. Es wird der dringende Verdacht geäußert, daß langfristige Vinylchlorid-Exposition dieses komplexe Krankheitsbild verursacht. Daher wird für diese systemische Krankheit die Bezeichnung Vinylchlorid-Krankheit vorgeschlagen.Wir danken Frau E. Voigtländer für die Herstellung der klinischen und histologischen Abbildungen.     

Empathic processes: perception by medical students of patients'' anxiety and depression

Perceptions by medical students of patients' affective states were investigated, and the effect of the students' own emotions on such perceptions. One hundred and one fourth-year medical students rated the levels of anxiety and depression of three women patients presented on videotape, rated their own levels of anxiety and depression and completed a questionnaire on aspects of the rating process. Students had widely different and often inappropriate perceptions of patients' levels of anxiety and depression. Students who consistently overrated anxiety or depression in patients, compared to those who consistently underrated, were themselves significantly more anxious or depressed. These data suggest a need in medical education for systematic teaching of empathic skills and for recognition of potential bias in clinical decision-making arising from the clinician's own emotional state.     

The reported incidence of work-related ill-health in Scotland (2002-2003)

BACKGROUND: Although incidence data for work-related ill-health in the UK are available, more detailed information for smaller geographical areas has hitherto been unpublished. AIMS: To estimate the incidence of work-related ill-health reported by clinical specialists in Scotland, 2002-2003. METHODS: THOR (The Health and Occupation Reporting network) is a UK wide reporting scheme for work-related ill-health. In 2002-2003, 241 out of 2162 physicians in THOR were based in Scotland. We have summarized the reported cases and calculated incidence rates for categories of ill-health by age, gender and industry. The UK Labour Force Survey (2002) was used to provide denominator data, with comparisons made between rates for Scotland and the rest of the UK. RESULTS: In 2002-2003, 4043 estimated cases were reported from Scotland. Mental ill-health was most frequently reported (41%); followed by musculoskeletal disorders (31%), skin disorders (16%), respiratory disease (10%), hearing disorders (2%) and infection (1%). The reported average annual incidence rate per 100,000 employees for all work-related ill-health in Scotland was 86.0. The highest reported rate for mental ill-health was found for employees in public administration and defence (76.7 per 100,000), and health and social work (72.3 per 100,000). The construction industry had the highest reported rate of musculoskeletal disorders (41.6 per 100,000), while hairdressers appeared at most risk of developing occupational contact dermatitis (rate=86.4 per 100,000). CONCLUSIONS: Despite its limitations, THOR has indicated types of work-related ill-health and related industries for targeted disease prevention in Scotland.     

Function of the protein RPE65 in the visual cycle

A protein called RPE65 performs a key role in the trans-cis isomerization of retinol in the retinal pigment epithelium of the eye. The palmitoylation of RPE65 serves to switch off the visual cycle in darkness and to switch it on in the light.     

Acute symptoms following work with pesticides

BACKGROUND: Serious accidental poisoning by pesticides is rare in the UK, but more minor pesticide-related illness may be under-reported. Anecdotally, use of sheep dip has been linked with flu-like symptoms. AIM: To explore the frequency, nature and determinants of acute symptoms following work with pesticides. METHODS: A postal survey of men in three rural areas of England and Wales provided data on occupational use of five categories of pesticide, occurrence of 12 specified symptoms within 48 h of using pesticides and tendency to somatize. Risk factors for pesticide-related symptoms were assessed by modified Cox regression. RESULTS: Of 10 765 responders (response rate = 31%), 4108 had at some time used pesticides occupationally, including 935 (23%) who reported symptoms following such work on at least one occasion. In two areas, acute symptoms were most frequent following use of sheep dip (29 and 32% of users), but in the third area the rate was significantly lower (13% of users). The relative frequency of symptoms was similar for all five categories of pesticide, and flu-like symptoms did not cluster unusually among users of sheep dip. Risk of pesticide-related symptoms increased with somatizing tendency (prevalence ratio for highest versus lowest category 2.4, 95% confidence interval 2.0-3.0) and was higher in men who had used pesticides most often or handled concentrate. CONCLUSION: Acute symptoms are common following work with pesticides, but in many cases the illness may arise through psychological rather than toxic mechanisms.     

The Life Events Inventory: re-scaling based on an occupational sample.

The objective of this study was to compare the validity of the original weightings used by the Life Events Inventory (LEI) with those obtained from a contemporary occupational sample. Fifty male and 62 female manufacturing employees (age range 16-55 years) assigned scores to each item on a slightly modified version of the LEI scale. The current sample consistently assigned higher weights to events/items than did the original sample, but there was high agreement in terms of item ranking. Some distinct age and gender differences in scoring were apparent, and are discussed further. It was concluded that when separate weightings are employed for age and gender groups, the LEI remains a useful tool for quantifying background levels of stress in both workplace stress audits and epidemiological studies where statistical control for non-occupational sources of stress is required.     

Maxillofacial injuries related to work accidents: a new concept of a hospital-based full electronic occupational trauma surveillance system

The objective of this study was to investigate the occurrence of occupational maxillofacial injuries using a newly installed relational database. Twenty-six injuries were identified out of 28,624 patients admitted to the emergency unit during a 12 month period. Falls from height or being struck by moving objects were common causes of these injuries. Two-thirds of those identified were construction workers. This paper demonstrates the power of modern databases to identify specific occurrences that may provide the basis for prevention in the future.     

Rôles physiologiques des endocannabinoïdes dans le contrôle de l’homéostasie énergétique

Endocannabinoids are endogenous lipids which modulate the release of neurotransmitters and activate different signaling pathways, through the binding to cannabinoïd receptors, CB1 and CB2. Endocannabinoids are involved in the control of a variety of behavioural and neuroendocrine functions, including feeding behaviour. In the central nervous system, they essentially modulate the expression of orexigen or anorexigen neuropeptides thus resulting in the stimulation of food intake. Their peripheral targets are mainly the liver and the white adipose tissue where they stimulate lipogenesis, through the modulation of several enzymes and proteins expressions. Cannabinoïd receptor agonists are nowadays prescribed to improve appetite of people suffering from cancer or AIDS. In the same way, CB1 antagonist, such as Rimonabant, could provide efficient treatment of obesity.