TREATMENT OUTCOMES IN MODERATELY LEAD TOXIC CHILDREN

拟议研究的长期目标是改善有害的 增加儿童铅（Pb）吸收的影响。 为此我们 将继续评估生物化学和功能的后果， 在一个全面的范围内， 临床研究计划的重点是螯合治疗的效果。 我们的多学科方法侧重于身体之间的关系， 铅的负担和三种类型的结果。 人体铅负荷 通过三种方式测量：1）血铅浓度，最近的指标 暴露; 2）CaNa 2 EDTA测试期间的尿铅排泄， 可动铅库; 3）骨的X射线荧光测定 铅，一种直接，非侵入性和定量测量骨铅， 随着时间的推移而积累。 结果指标是那些受到影响的指标 铅的负担。 包括：1）生化异常， 全血中红细胞原卟啉水平和1，25- 血清中的二羟维生素D（1，25-（OH）2D）和骨钙素浓度; 2)中枢神经系统功能障碍， 躯体感觉诱发电位; 3）反映的行为缺陷 通过全球情报措施，除了具体措施， 注意力和反应时间。 前/后处理设计允许 我们来描述随着时间的推移治疗对多种结果的影响， 推断中度铅毒性对 儿童的大脑功能和行为，并探讨不同的手段， 铅发挥其毒性作用。

The long-term goal of the proposed research is to ameliorate the harmful effects of increased lead (Pb) absorption in children. To this end, we will continue to assess the biochemical and functional consequences of moderate body burdens of Pb in young children within a comprehensive clinical research program focused on the effects of chelation treatment. Our multidisciplinary approach focuses on the relationships between body burden of Pb and three types of outcomes. Body Pb burden is being measured in three ways: 1) blood Pb concentrations, an index of recent exposure; 2) urinary Pb excretion during CaNa2 EDTA testing, an index of mobilzable Pb stores; and 3) L x-ray fluorescence determination of bone Pb, a direct, non-invasive and quantitative measure of bone Pb that has accumulated over time. The outcome measures are those which are affected by lead burden. these include: 1) biochemical abnormalities -- erythrocyte protoporphyrin levels (EP) in whole blood and 1,25- dihydroxyvitamin D (1,25-(OH)2D) and osteocalcin concentrations in serum; 2) central nervous system dysfunction as indexed by auditory and somatosensory evoked potentials; and 3) behavioral deficits as reflected by global measures of intelligence in addition to specific measures of attention and reaction time. A pre-/post-treatment design is permitting us to describe the effects of treatment on multiple outcomes over time, to make inferences about the effects of moderate Pb toxicity on children's brain function and behavior, and to explore different means by which Pb exerts its toxic effects.