部分食品中化学污染物铅和镉的含量调查

目的调查研究珠海市菜篮子食品中铅、镉污染情况。方法于2005-2007年从农贸市场、酒店酒家,按照随机采样原则,采集189份食品,依据GB/T5009.12-2003、GB/T5009.15-2003所规定的方法对所采集的样品进行铅、镉含量检测。结果189份样品中,有17份样品的铅或镉含量超标,超标率为8.99%。单纯铅含量超标的样品11份,超标率为5.82%,主要是皮蛋,超标率有33.33%;单纯镉含量超标的样品7份,超标率为3.70%,主要是食用菌,超标率有40.00%。结论珠海市部分食品中存在铅和镉污染问题。     

重金属暴露及其致癌分子机制的研究进展

随着工业化活动和环境污染的加剧,对环境致癌物的监测、评估及防控已经成为人类健康所面临的重大研究课题。越来越多的研究表明,空气、水,土壤等环境中的重金属通过多种方式进入人体,不仅损害人体的血管、神经、免疫,以及造血功能,而且在体内的蓄积还可以导致癌症的发生。重金属致癌成为目前肿瘤预防和干预研究所关注的重点之一。该文针对镉、砷、铅汞暴露导致癌症发生的分子医学方面的研究进展予以综述。     

不同类型心房起搏电极的安置经验

报告安置不同类型心房电极５６例的经验。其中螺旋电极２１根（内收式单极１１根、双极８根，暴露式单极２根），倒叉Ｊ形电极３５根。５６例的心房电极均于首次手术时安置成功，住院期间无电极脱位、心肌穿孔及阈值异常增高。随访期有１例患者倒叉电极移位；内收式螺旋单、双极电极和倒叉电极各有１例晚期阈值增高。严格遵守操作规程，将心房电极安置于右心耳并使Ｘ线和心电测试的指标及起搏参数达到可靠的要求，则有助于提高安置心房电极的成功率，并能减少电极移位和阈值升高。     

合肥市大蜀山几种药用植物体内铅的含量分析

目的:以安徽省合肥市郊大蜀山几种常见的药用植物为例,分析铅(Pb)在药用植物不同部位的分布,初步探索Pb在药用植物体内分布的规律。方法:采用湿法消化、原子吸收分光光度法测定Pb元素的含量。结果:植物体内Pb的含量与植物种类和生长环境有关。本实验为从源头控制中药材和中成药重金属超标提供科学依据。     

宝鸡市市区268名儿童铅中毒情况的相关因素分析

目的研究宝鸡市市区儿童铅中毒相关因素,提出干预对策.方法严格按照有关要求,采用原子吸收石墨炉法进行血铅测定;对测试血铅高于100 μg/L的儿童通过问卷调查相关影响因素.结果 268名儿童血铅水平平均为150 μg/L ,其中血铅水平≥100 μg/L者占79.85%.结论宝鸡市市区属于工业城市,儿童铅中毒检出率较高,应引起高度重视.     

aVR – the forgotten lead

Electrocardiography continues to be a focal point of modern medicine, and the electrocardiogram (ECG) continues to be the most frequently ordered cardiac test. Most of the clinical importance of the ECG rests on the invaluable information it renders in diagnosing acute coronary syndromes and cardiac arrhythmias. However, the ECG is a valuable tool and diagnostic aid in the evaluation of many other conditions such as pericarditis and pulmonary embolism. Of the electrocardiographic leads, aVR has traditionally received less attention in clinical evaluation of the ECG. The present study discusses instances with pictorial examples in which lead aVR provides valuable clinical information and makes a case for close attention being paid to this ‘forgotten lead’.     

Asymptomatic congenital lead poisoning – case report

Context. Congenital lead poisoning is uncommon and there is no consensus on the management of the newborn. Case Details. A female infant was born to a lead-burdened woman identified by screening just prior to delivery. Maternal blood lead level (BLL) was 58 μg/dL. The infant's BLL on the second day of life was 72 μg/dL with a free erythrocyte protoporphyrin level of 175 μg/dL. The child was managed by an exchange transfusion followed by chelation. The BLL 6 h after exchange transfusion was 11.4 μg/dL. Follow-up 2 years later showed a BLL of 9 μg/dL and normal development. Discussion. We present the details of a case of congenital lead poisoning treated aggressively which appears to have resulted in a favorable outcome.     

Region of Interest Sensitivity Ratio in Analyzing Sensitivity Distributions of Electrocardiographic Measurements

Modern devices such as wearable and implantable systems provide new methods for bioelectric measurement while creating new needs to assess the efficacy of the measurements. A modeling related analysis method, called the region of interest sensitivity ratio (ROISR), has been developed and applied hitherto in analyzing EEG measurements. ROISR describes how well the sensitivity of a measurement is concentrated within the region of interest (ROI). The objectives of the present study were to demonstrate and evaluate the applicability of this method in analyzing the specificity of ECG leads and to compare the results with those previously published. Here the specificities of the 117 leads of a Dalhousie body surface ECG mapping system to different segments of the left ventricular myocardium and the whole right ventricular free wall were analyzed. The ROISR method was also validated with epicardial dipole simulations. The results are consistent with those from previous clinical studies, and the ROISR method is thus applicable in future studies where, e.g., sensitivity distributions of implantable ECG measurements are analyzed.     

Chronic effects of low lead levels on sperm quality, gonadotropins and testosterone in albino rats

The current study evaluates the impact of low or moderate levels of lead acetate (PbAc) on sperm parameters, gonadotropins (FSH, LH) and testosterone. Adult albino wistar male rats were allocated to five groups and given 0%, 0.025%, 0.05%, 0.1% and 0.3% PbAc in distilled drinking water for 24 weeks.There was no change in body weight gain and in absolute or relative weight of testes, epididymides and seminal vesicles. The ventral prostate weight was decreased in groups exposed to 0.05%, 0.1% and 0.3% PbAc without statistically significant differences.Sperm velocity was decreased in all treated groups while reduction of sperm motility was observed in rats exposed to 0.05%, 0.1% and 0.3% PbAc without statistically significant differences compared to the control group. However, there was a significant increase greater than 100% in the total percentage of abnormal sperm in groups treated with 0.1% (p<0.01) and 0.3% PbAc (p<0.05).The frequency of dead sperm was significantly increased only in the 0.3% PbAc group (p<0.01). Significant increases in frequencies of amorphous head sperm (p<0.01) and abnormal tails (p<0.01) were found in the group exposed to 0.1% PbAc, while the frequency of neck abnormalities was increased in the high-lead-exposed group (p<0.01).The levels of LH and FSH were not significantly affected after lead treatment and significant increase in serum testosterone level was noted only in animals administered 0.05% PbAc (p<0.01).In conclusion, our results reveal that some sperm parameters were altered at low or moderate lead concentrations with no obvious alteration of hypothalamic–pituitary function. The increase of testosterone level observed suggests that lead may target testicular function.     

血铅对细胞免疫黏附功能影响的研究

目的评估血铅对儿童细胞免疫黏附(TRR、TLR、TGR)的影响,探讨血铅对细胞免疫黏附的影响程度以及血铅临界值与细胞免疫黏附的关系。方法根据血铅值将儿童分为3组:≥0.48μmol/L组26例,0.24~0.48μmol/L组40例,<0.24μmol/L组54例。①采用石墨炉原子吸收光谱法测定血铅水平。细胞免疫黏附测定采用新鲜血免疫黏附肿瘤细胞花环实验。②血铅与细胞免疫黏附肿瘤细胞的关系采用直线相关分析。结果高铅组与低铅组比较细胞免疫黏附率差异显著。铅分界值越高免疫黏附率改变越明显。①≥0.48μmol/L组儿童TRR和TLR表达明显低于<0.24μmol/L组(t=3.48,2.32,P<0.01)。②血铅值≥0.48μmol/L时血铅水平与TRR、TLR表达呈显著负相关(r=-0.703,-0.606,P<0.01)。结论铅对小儿细胞免疫黏附功能有不良影响,两者存在相关关系。