TREATMENT OUTCOMES IN MODERATELY LEAD TOXIC CHILDREN

这项拟议的研究的长期目标是改善 适量铅摄取对儿童的影响按顺序 为此，我们希望评估生化和功能后果 儿童体内铅的中等身体负荷量 临床研究计划的重点是螯合治疗的效果。 由于我们的多学科方法，我们关注的是 人体铅负荷与三种结局的关系身躯 铅负荷的测量有三种方式：1)血铅浓度，一项指标 最近接触；2)CaNa2EDTA刺激时的尿铅排泄 测试，可移动铅储存的指标；以及3)X射线荧光 骨铅测定，骨铅蓄积的直接测定 随着时间的推移。结果衡量标准，即那些受铅负担影响的指标， 包括1)生化异常--红细胞原卟啉水平 全血中的(EP)和1，25-二羟基维生素D(1，25-(OH)2D) 血药浓度；2)中枢神经系统功能障碍指标 听觉和体感诱发电位；3)行为缺陷 以全球情报衡量标准以及具体衡量标准为索引 注意力和反应时间。前/后处理设计将允许我们 为了描述随着时间的推移治疗对多种结果的影响， 推断中度铅中毒对儿童的影响 脑功能和行为，并探索铅可能通过的不同途径 发挥它的作用。

The long-term goal of the proposed research is to ameliorate the harmful effects in children of absorbing moderate amounts of lead (Pb). In order to do this, we wish 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. Because of our multidisciplinary approach, we are concerned with the relationships between body burden of Pb and three type of outcomes. Body Pb burden is measured in three ways: 1) blood Pb concentrations, an index of recent exposure; 2) urinary Pb excretion during CaNa2EDTA provocative testing, an index of mobilizable Pb stores; and 3) x-ray fluorescence measurement of bone Pb, direct measurement of bone Pb that has accumulated over time. The outcome measures, that is, those affected by lead burden, include 1) biochemical abnormalities -- erythrocyte protoporphyrin levels (EP) in whole blood and 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentrations in serum; 2) central nervous system dysfunction as indexed by auditory and somatosensory evoked potentials; and 3) behavioral deficits as indexed by global measures of intelligence as well as specific measures of attention and reaction time. A pre-/post-treatment design will allow 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 may exert its effects.