母鼠妊娠及哺乳期铅摄入致后代学习记忆损害动物模型的建立

目的建立妊娠及哺乳期铅摄入对后代学习记忆损害的动物模型的影响。方法母鼠在妊娠及哺乳期的不同阶段给予铅暴露后观察子鼠的学习记忆能力的变化,孕鼠70只,自确定受孕后即随机分成7组。孕早期低剂量组(60mg/kg)和孕早期高剂量组(240mg/kg),于受孕第0天给醋酸铅直至仔鼠断乳,其染铅42d;孕晚期低剂量组(60mg/kg)和孕晚期高剂量组(240mg/kg),于受孕第14天起给醋酸铅至仔鼠断乳,共染铅28d;出生后低剂量组(60mg/kg)和高剂量组(240mg/kg),于分娩日起给醋酸铅至仔鼠断乳,共染铅21d;另设阴性对照组。结果大鼠在孕期和哺乳期给铅致20日龄后代幼鼠的定位航行能力受到明显影响。随着训练时间的增加,对照组的幼鼠逃避时间显著缩短,而在孕期和哺乳期给铅致20日龄各组后代幼鼠的逃避时间并没有显著缩短,与对照组比较,差异具有统计学意义。在训练7d后进行空间探索测试,对照组幼鼠搜寻平台的时间明显较实验各组快,差异具有统计学意义;穿越平台的次数对照组也显著多于实验各组,差异有统计学意义;在第Ⅰ象限停留的时间比实验各组要长,差异有统计学意义。结论母鼠妊娠及哺乳期铅处理的各组幼鼠空间学习记忆能力有明显的影响,此模型适合进一步研究围产期铅暴露后子代学习记忆的影响。     

铅的神经毒性及螺旋藻的拮抗效应

目的探讨螺旋藻对铅致神经毒性的拮抗作用。方法采用口服醋酸铅(PbAC2)溶液方法建立小鼠铅中毒模型,用螺旋藻灌胃进行实验性治疗。持续6周后,实验检测小鼠学习、记忆成绩和抗疲劳能力,并测定脑组织和血浆中丙二醛(MDA)含量。结果与对照组相比,模型组的学习、记忆能力下降,抗疲劳能力降低;MDA含量增高,差异均有统计学意义(P0.05或P0.01)。与模型组相比,治疗组的学习、记忆能力和抗疲劳能力又得到改善,MDA含量也降低,差异均有统计学意义(P0.05或P0.01)。结论铅可降低小鼠的学习、记忆能力和抗疲劳能力,而螺旋藻对铅导致的神经毒性有一定的拮抗作用。     

十堰市2～6岁集居儿童血铅现状分析

目的:了解十堰市城区2～6岁集居儿童血铅水平现状并分析其影响因素。方法:血铅采用石墨炉原子吸收光谱法测定,并对儿童家长进行问卷调查。结果:2431名集居儿童的血铅平均值为0.487μmol/L,其中,1092名儿童血铅≥0.483μmol/L。结论:目前十堰市城区集居儿童平均血铅水平与铅中毒率较高,应采取措施对诱发因素进行控制。     

职业铅接触致肾损伤的危险度评定

目的 通过职业流行病学调查和基准剂量计算,对职业性铅接触所造成的肾损伤进行危险度评定.方法 以浙江某蓄电池生产工厂239名工人为接触组,同地区某厨具厂工人76名为对照组,对工人开展问卷调查与体格检查,采集生物样本.收集车间空气中铅监测资料,计算工人在车间中接触的铅的总量,考查铅外剂量与内剂量之间的关系;以外剂量(铅参考接触剂量)、血铅、尿铅为接触标记,以尿中N-乙酰-β-D-氨基葡萄糖苷酶(UNAG)和尿白蛋白(UALB)(均以尿肌酐进行校正)为效应标记.采用基准剂量计算软件(BMDS 11311)计算基准剂量反应为5%时,各效应标记的血铅、尿铅基准剂量.结果 铅的外剂量与内剂量呈正相关(血铅:r=0.466,P<0.01;尿铅:r=0.383,P<0.01),铅接触组的血铅、尿铅水平分别为654.03μg/L、143.45μg/g Cr,明显高于对照组(分别为57.12μg/L、7.20μg/gCr),且呈剂量-效应关系;按照对照组效应指标的95%上限为参考值上限,求得各效应指标的异常发生率与接触指标呈剂量-反应关系;UALB、UNAG的血铅BMDL-05分别为607.76、362.56μg/L,UALB、UNAG的尿铅BMDL-05分别为117.79、78.79 μg/Cr.结论 职业铅接触可致肾损伤,且呈剂量-反应关系;使用计算血铅、尿铅BMD的方法能进行职业铅接触的肾损害危险度评定.     

某蓄电池厂铅危害的调查

目的了解某蓄电池厂铅危害状况,为采取相应卫生防护措施提供依据。方法采用职业卫生学调查、工作场所职业病危害因素现场监测和职业健康检查,对结果进行统计分析。结果作业环境空气中铅浓度超标高达71%,168名铅作业工人检出疑似职业性慢性轻度铅中毒26人,慢性铅中毒观察对象53人,并有不同程度的神经系统和消化系统的症状。结论该蓄电池厂存在较严重的职业危害,必须采取积极有效的防护措施。     

铅诱导人脐静脉内皮细胞损伤及机制研究

目的探讨铅诱导人脐静脉内皮细胞损伤效应及机制。方法用不同浓度的铅染毒人脐静脉内皮细胞,观察细胞形态和活性,通过检测细胞上清液丙二醛(MDA)、非对称性二甲基精氨酸(ADMA)、一氧化氮(NO)的含量和一氧化氮合酶(NOS)的活性等指标,观察铅对人脐静脉内皮细胞损伤的量-效关系(终浓度分别为1、2、4、8mg/L的铅处理细胞24h)和时-效关系(终浓度为4mg/L的铅分别于处理0、3、6、12、24、48h后观察检测指标)。实验分为正常对照组(加入与处理组等体积的D-Hank’s液,铅浓度为0mg/L)、铅处理组(加终浓度分别为1、2、4、8mg/L的铅)、铅VitC组(铅终浓度为4mg/L,VitC终浓度为100mg/L)和阳性对照组(加终浓度为500μg/L的过氧化氢)。结果 2～8mg/L的铅能显著改变细胞形态、降低细胞活性;能显著性诱导内皮细胞MDA升高。2～8mg/L的铅还能显著性诱导内皮细胞NO含量降低,具有显著的时间依赖性,各处理组间两两比较差异有统计学意义(P0.05或P0.01)。4mg/L铅处理时细胞ADMA含量最高,且分别在处理后24h到达最高峰。结论 2～8mg/L铅能显著诱导人脐静脉内皮细胞损伤;ADMA在铅诱导人脐静脉内皮细胞损伤中有着重要作用。     

Lead Levels in Vegetables from Artisanal Mining Sites of Dilimi River,Bukuru and Barkin Ladi North Central Nigeria: Cancer and Non-Cancer Risk Assessment

Lead (Pb) contamination of foods and especially of frequently consumed vegetables is a growing public health concern worldwide. Although levels of exposure in developed countries have declined over the past decades, the same cannot be said of developing countries. Health risk assessment has increasingly been employed to determine the potential hazard of heavy metal exposure to humans. In this study vegetable samples (tomatoes, red pepper, brown beans, lettuce, cabbage, Irish potatoes, onions, green beans and carrot), soil samples, irrigation water and sediment samples were collected from the Dilimi River, Bukuru and Barkin Ladi communities in north central Nigeria and analyzed for Pb content using atomic absorption spectroscopy. The results showed levels with ranges from 0.5 – 2.4 mg/kg (Dilimi River), 0.3 – 1.7 mg/kg (Barkin Ladi) and 1.46 – 1.89 mg/kg (Bukuru) in vegetables were largely above the maximum permissible limit recommended by WHO/FAO. The lead levels found in soil samples, which ranged from 9.19 – 36.042 mg/kg, also exceeded some safety standards. At least 75% of the calculated estimated daily intakes of Pb from different vegetable samples were also higher than the permissible tolerable daily intakes PTDI (0.0035 mg/kg day-1) of Pb in both adults and children. Target hazard quotient THQ values > 1 were also observed in children. In conclusion, there is a health risk from consumption of vegetables in these mining communities.     

磷酸氢铈纳米吸附剂预富集-火焰原子吸收法 测定水中痕量铅

摘要:目的　建立磷酸氢铈（CeP）一维纳米吸附剂预富集-火焰原子吸收法测定水体中痕量铅的新方法。方法　用10 mg CeP 对pH为2～9的200 ml水样中的Pb2+吸附富集30 min,抽滤后再用4.00 ml 2 mol/L的硝酸溶液解吸60 min,用火焰原子吸收法测定解吸液中的Pb2+。结果　该方法测定Pb2+的线性范围为10～400 μg/L,回归方程为y＝0.0011x + 0.0043,线性相关系数r＞0.999,检出限为1.14 μg/L,相对标准偏差为1.12%（n＝9,80 μg/L）,加标回收率为99.8%～107.5%。结论　本方法线性范围宽,灵敏度高,准确度和精密度良好,操作条件简单,测定成本低,可应用于环境水样中痕量铅的测定。     

石墨炉原子吸收光谱法测定水果和蔬菜中的痕量铅镉

目的 建立水果和蔬菜中铅镉的石墨炉原子吸收光谱测定法。方法 样品加入硝酸-过氧化氢消解液后放置过夜,次日直接在智能样品处理器上进行低温赶酸。采用石墨炉原子吸收光谱法测定。结果 铅和镉浓度分别在0～20 ng/ml和0～2 ng/ml范围内线性相关系数分别为0.9989和0.9986,检出限分别为0.76 μg/L和0.033 μg/L,RSD在2.16%～4.90%之间,加标回收率在90.0%～98.3%之间。结论 该方法空白值低,简单易行,灵敏度高,准确性好,适用于水果蔬菜中铅和镉的快速测定。     

Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check:The role of highvoltage shock testing

AIM To describe our experience with shock testing for the evaluation of patients with Riata? leads.METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation(VF) induction and in 5 cases a R-wave-synchronized shock( 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients(80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients(20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance( 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF.CONCLUSION In Riata? leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing.