儿童血铅与其它微量元素水平的关系

为探讨儿童血铅与血锌、铁、铜、钙、锰含量的相互消长关系 ,利用多元线性回归分析对 2 1 72名儿童的血微量元素及血铅进行了分析。结果显示 ,被调查儿童中 47 5 6%的儿童血铅升高 ,全部呈轻 中度升高 ( 0 1 0～ 0 44μg/mL) ;钙、铁、锰对血铅值的倒数 (PB1)的作用显著 (P<0 0 1 ) ,但相关并不密切 ,偏相关系数分别为 -0 0 79,0 0 7,0 0 6;血钙与血锌、铜之间有明显的交互作用 ,儿童体内血钙对血铅的影响依赖于血铜、锌的含量 ;血铁和锰含量与PB1呈正相关 ,即与血铅水平呈负相关 ,两者的部分作用又被它们之间的交互作用所减弱。结果提示 ,轻 中度铅中毒仍是城市儿童中普遍存在的一个重要问题 ,除了控制铅污染源外 ,还要注意适当补充铁剂 ,合理饮食以保持机体内钙锰等各种微量元素间的平衡也是重要的防治措施。     

24万深圳市学童铅中毒的筛查

为给深圳市儿童铅中毒的防治提供基础资料和指导,对深圳市学童的铅中毒进行了大规模的筛查,从2001年10月至2004年1月,分五个阶段,总检测人数达241283人,检测主要采用ZPP,血锌原卟啉测定法。结果表明,五个阶段铅偏高和超高总人数为110140人,铅超标比例为45．65％。对300名家长和23880名筛查儿童进行了电话调查和访问。对筛查结果的准确性、铅中毒筛查方法、儿童铅中毒形势、环境与铅中毒的关系等进行了讨论。并采取了一些防治措施,给有关方面提出了防治铅中毒的建议,对铅防治工作作出了贡献。     

五味子联苯环辛烯类木脂素成分的结构与药理活性关系和药物创新

传统中药五味子具有多种药理活性。20世纪70年代以来,我国临床发现五味子能改善慢性肝炎病人的肝功能异常,在此基础上,我所化学家和药理学家对五味子分离得到的20余种联苯环辛烯类木酯素成分和其药理作用进行了大量研究。五味子的药理活性主要有:保肝,抗氧化,诱导肝药酶,增强解毒功能,促进蛋白质、糖原合成,克服肿瘤耐药性,增强对抗药癌的敏感性以及对中枢神经系统的镇静作用。在这些研究基础上,合成了保肝作用最强的五味子丙素结构类似物,相继研制出两种抗肝炎新药联苯双酯（DDB）和双环醇（bicyclol）。本文对五味子木脂素类成分的结构与药理活性关系以及两种新药的创制做一综述。     

乘员股骨在轴向压力-弯矩下的损伤生物力学机理研究

汽车前碰撞事故中在冲击力作用下乘员股骨经常产生骨折创伤.为研究乘员股骨在不同的轴向压力-弯矩作用下的损伤机理及其耐受限度值,首先建立了一个较为精细的50百分位乘员的坐姿下肢有限元模型,并通过模拟股骨动态三点弯曲及下肢的轴向膝部冲击实验对模型的有效性进行了验证.在此基础上,针对股骨在轴向压力-弯矩载荷下的断裂失效分别进行了曲梁力学模型分析及有限元虚拟实验研究.结果表明:股骨骨折位置依赖于膝部轴向压力及弯矩的载荷大小的变化,在预加载弯矩从0增加到676Nm时,股骨失效部位由股骨颈部转移到股骨干末端区域;失效部位发生在颈部及股骨干时的最大力矩分别为285 296Nm和381443Nm.股骨损伤机理的分析结果阐释了在膝部轴向冲击实验中失效部位位于股骨颈部,而在汽车前碰撞事故中仍有大量的股骨干骨折出现的原因.      

1 332例儿童头发微量元素检测分析

为了解信宜市城区幼儿园儿童体内微量元素含量情况,回顾性分析了2003年信宜市城区幼儿园3至7岁儿童头发微量元素普查资料。结果表明,本区儿童缺锌率20．42％,缺碘率14．26％,缺钙率8．86％,缺铁率3．00％,铅高率42．04％。提示该市城区幼儿园儿童体内微量元素失衡相当普遍,必须加强幼儿园管理,监测和指导儿童微量元素营养,开展健康教育,提高群卫生保健意识,普通城区也要开展儿童铅中毒防治工作。     

高跟鞋致损伤的生物力学与流行病学研究进展

以降低高跟鞋损伤风险为出发点, 对高跟鞋步态生物力学特征进行系统综述, 并结合相关流行病学依据对高跟鞋引发的肌肉骨骼系统损伤情况作出总结, 为进一步研究提供思路. 对高跟鞋步态中足底压力分布、下肢各关节三维角度变化及关节力矩特征三方面进行了较为全面的总结与分析, 并且明确阐述了高跟鞋对踝关节扭伤、足部疼痛及摔倒的生物力学机制的影响. 但到目前为止, 没有足够的流行病学研究证据可以证明高跟鞋会增加膝关节炎的患病风险. 随着对高跟鞋步态及其损伤机制更为明确与深入的认识, 高跟鞋设计也将朝着更加人性化与合理化的方向发展.     

Effect of plating and incubation conditions on the detection of lactic acid bacteria after high hydrostatic pressure treatment

ABSTRACT

Lactic acid bacteria (Leuconostoc mesenteroides, Enterococcus faecalis, and Lactobacillus fermentum) were subjected to high hydrostatic pressures (HHPs) of 400 and 600?MPa at 25°C for 10?min in phosphate-buffered saline. Differential plating methods were applied to evaluate HHP-treated cell populations, assuming that healthy and injured cells during plate incubation survived maximum and minimal stress, respectively. The stress was altered by using several selective media in combination with aerobic or anaerobic incubation at 25°C or 30°C. E. faecalis was detectable after 600?MPa treatment while L. mesenteroides and L. fermentum were nondetectable. Specific combinations of incubation conditions were suggested to determine maximum and minimum viable counts of L. mesenteroides and E. faecalis. The difference between the maximum and minimum counts can be used to evaluate HHP-injured population with reduced risks to overestimate healthy and/or underestimate HHP-injured cells.     

Dysphonia and bulimia: Vomiting laryngeal injury

Voice problems associated with vomiting laryngeal injury in bulimic patients have not been previously described in the literature. Injuries found include subepithelial vocal fold hemorrhages that probably go on to produce mucosal wave tethering. More severe scarring may also result, but superficial telangiectasia of the glottic mucosa seems to be a more common feature. Three patients from a voice clinic population are described, and a further 10 patients from an eating disorders clinic who had not presented with voice complaints were studied with questionnaires, history, video laryngostroboscopy, and voice recordings.     

Investigation on the effects of diamide on NO production in vascular endothelial cells (VEC)

Nitric oxide (NO) controls several physiological functions of the cardiovascular system. The study on the effect of diamide (N₂H₄·H₂O) on NO production in vascular endothelial cells (VEC) may provide significant reference for VEC’s modeling in studying cardiovascular diseases. The objective of this study was to elucidate how high concentration diamide (V_diamide/V_{culture miedium}=5 ml/l) and low concentration diamide (V_diamide/V_{culture miedium}=0.5 ml/l) affect NO production in a human endothelial cell line (ECV304). After cells were incubated with diamide (5 or 0.5 ml/l) for 4, 6, 8 or 10 h, respectively, the amounts of NO metabolites released by the cells were quantitated and the degree of damage of VEC was observed using microscope. The results showed that NO production in VEC tended to decrease with the lapse of time in the 0.5 ml/l diamide group. In the 5 ml/l diamide group, on the contrary, NO production in VEC tended to increase with the lapse of time. At the same time, from the morphologic observation, the VEC were damaged severely after treated with 5ml/l diamide. So it could be concluded that the severe damage induced by high concentration diamide would have triggered the express of inducible nitric oxide synthases (iNOS). Just for the expresssion of iNOS, NO production in VEC treated with high concentration diamide occurred abnormally in contrast to the 0.5 ml/l group.     

Impact non-pénétrant sur le thorax : influence de la courbure sur la propagation des ondesNonpenetrating impact on the thorax: influence of curvature on wave propagation

Theoretical studies of the propagation of impact waves through the thorax are needed to improve the design of bulletproof jackets and blast protections (Fung in ‘Biomechanics Motions, Flow, Stress, and Growth’, Springer-Verlag, 1990; Cooper et al., J. Trauma 40 (1996) S38–S41). The influence of the weak acoustic coupling at the interface between the thoracic wall and the lung were described in (Grimal et al., C. R. Acad. Sci. IIB 329 (2001) 655–662); in this work, we study, within the frame of elastodynamics and with an approximate analytical method, the effects of the curvature of this interface. Results are given in terms of strain energy for the pressure wave, transmitted or converted. Focalisation of energy in the medium representing the lung is important for curvatures measured in humans. To cite this article: Q. Grimal et al., C. R. Mecanique 330 (2002) 569–574.