δ-氨基乙酰丙酸脱水酶基因多态性对职业铅接触工人血铅和锌原卟啉的影响

[目的 ]研究δ 氨基乙酰丙酸脱水酶 (ALAD)基因多态性对职业铅接触工人血铅 (PbB)和锌原卟啉 (ZPP)的影响。 [方法 ]采集 170名上海市某蓄电池厂职业铅接触工人外周静脉血样 ,多聚酶链式反应 (PCR)和限制性内切酶 (MspⅠ )限制性片段长度多态性 (RFLP)方法进行ALAD基因分型分析 ,用PE 80 0型原子吸收分光光度计和ZPP 3 80 0型血液锌原卟啉测定仪分别测定PbB和ZPP含量 ,并分析其与基因型的关系。 [结果 ]①ALAD11纯合子基因型者有 15 4名 ,占90 5 9% ;ALAD12杂合子基因型者有 16名 ,占 9.41% ;未检出ALAD2 2纯合子基因型者 ;②ALAD1和ALAD2等位基因分布频率分别是 95 .2 9%和 4.71% ;③在同等外暴露条件下 ,ALAD12杂合子基因型组工人血铅水平 ( 1.0 4± 0 .48μmol/L)明显高于ALAD11纯合子基因型组工人血铅水平 ( 0 .78± 0 .3 4μmol/L) ,且差异有统计学意义 ;④ALAD12基因型工人锌原卟啉(ZPP)含量比ALAD11基因型者稍低 ,但差异没有统计学意义 ,前者为 ( 0 .42± 0 .2 4) μmol/L ,后者为 ( 0 .46± 0 .41) μmol/L。[结论 ]ALAD2等位基因频率与文献报道的亚洲人群的结果相近 ,符合Hardy Weinberg平衡 ,在同样职业铅暴露环境下 ,具有ALAD2等位基因的工人血铅水平增高 ,ALAD2等位基因可加重工人体内的铅     

An integrative index of biological effects of lead

Biological indicators of lead effects on the central nervous system (as measured by performance tests), hematogenous bone marrow (hemoglobin levels), and kidney function (BUN levels) can be combined in an integrative index (INDEX). This integrative index can be in turn related to indicators of lead exposure and absorption. Such an index was calculated by removing age effects in measures of performance and kidney function and then transforming all the variables to Z (standard) units. Secondary lead smelter workers and a control group were studied. In secondary lead smelter workers this INDEX was found to be significantly correlated with ZPP, blood lead levels, and duration of lead exposure. In this population the magnitude of the correlation coefficients with ZPP levels was much higher than that for blood lead levels. INDEX had a higher correlation with ZPP than with each of its components: performance test scores, hemoglobin, and BUN levels. Although performance test scores, hemoglobin, and BUN levels were shown to discriminate between the control, non-lead-exposed population, and the lead-exposed group, INDEX (and particularly one pair of its components, CNS and hemoglobin levels) achieved the best discrimination between groups. The concept of an integrative index of biological effects of lead may be especially useful in defining populations at high risk for developing chronic, potentially irreversible neurologic and kidney dysfunction, and in assessing the severity of lead effects in individual cases.     

从几个铅作业小厂的调查看乡镇企业的劳动卫生问题

对西安地区3个铅作业小厂进行了流行病学调查。发现其劳动条件均很差，车间内铅烟浓度普遍超标十几倍到几十倍；工人铅吸收与铅中毒总检出率高达53.1％。周围环境亦受到污染，污染区居民已受到铅的危害，建议重视乡镇企业的劳动卫生，制订有关法规，加强监督与管理。对铅中毒的筛栓指标进行了对比与讨论，认为ZPP可作为现场筛检的首选指标。     

红细胞游离原卟啉与锌卟啉对铅中毒临床诊断价值的研究

对72例轻度铅中毒、44例铅吸收及7例接触铅无铅中毒住院患者测定了PbB，CPbU(驱铅治疗第一日的尿排铅量)、ALAU、FEP，ZPP。微机分析结果指出不同病情的3组病例之间，5项指标都有极显著的差异，并高度相关，可以相互换算。相关分析表明曲线回归优于直线回归。FEP的升高程度大于ZPP。FEP与ZPP的优点是在慢性铅中毒很少出现假阴性，测定结果的稳定性较好，简便迅速而易于操作。缺点是接触铅后并不迅速升高，临床治愈后并不迅速恢复，测定结果与病情不平行，特异性也不够，评价时应注意这些不足之处。     

Occupational lead exposure

Summary Quantitative measures of saccadic eye movements were examined in 52 lead exposed autobody shop workers and 52 age matched controls with no history of occupational lead exposure. Three characteristics of saccadic eye movements were studied: 1) saccade accuracy; 2) number of overshoots; and 3) maximum velocity. The results indicated that workers exposed to inorganic lead showed a decrease in saccade accuracy and an increase in overshoots compared with controls. Saccade maximum velocity was lower in lead exposed workers than in controls but the difference was just short of statistical significance. Correlations between measures of saccadic eye movements and indicators of lead absorption—blood lead (Pb-B) and zinc protoporphyrin (ZPP) levels-were analyzed in the lead exposed workers. Saccade accuracy was negatively correlated with both Pb-B and ZPP levels. The number of overshoots was not correlated with either Pb-B or ZPP levels. Saccade maximum velocity was not correlated with Pb-B, however, there was a significant negative correlation with ZPP. Age effects observed in the control group were disrupted in lead exposed workers. In addition, saccadic eye movements in younger workers (below 30 years old) were more affected by exposure to inorganic lead than were saccadic eye movements in older workers (50 years and older). It is proposed that these findings are consistent with a relatively rapid buildup of metabolically active lead burden observed in the study group. The data suggest that quantitative assessment of eye movements may be an important tool for studying subclinical central nervous system (CNS) dysfunction due to inorganic lead exposure.Part of this study was presented at the XX International Congress on Occupational Medicine, Cairo, Egypt, Sept. 26–29 (1981)This study was supported in part by NIEHS grant ES00928 of the National Institute of Health, US Department of Health and Human Services     

用锌原紫质(ZPP)作为缺铁性红细胞生成的标记衡量感染免疫缺陷病毒(HIV)病人机体铁状况

尽管HIV病人的贫血很常见 ,但没有一个可靠的指标诊断缺Fe性贫血。因此我们研究了不同程度的感染HIV病人Zn原紫质 (ZPP)运铁蛋白饱和度 (TS)和铁蛋白。调查了 76名感染HIV病人的铁状况。用正面血液荧光检测 (afront -facedhematoflurimeter)测量ZPP ,用浊度测定法测铁蛋白和运铁蛋白。其中 4 2名病人患贫血 ,根据贫血程度不同将病人分为三组 :A组血红蛋白 (HB) >14g/dL ,B组 12～ 14g/dL ,C组Hb <12g/dL。A组与B组的研究参数差异不显著。C组出现显著不同 :β2 -球蛋白的均数值 3 6± 0 5mg/L(C组与B组相对比P <0 0 1和A组相比 ,P <0 0 0 1) ;CD - 4阳性T细胞均数 173± 4 1/ μL(和A组比P <0 0 1) ;ZPP均数 86± 12 μmol/mol血质 (和A组、B组相对照P <0 0 0 1,且铁蛋白均数 10 6 6± 377μg/L(P <0 0 1与A、B组相比 )。根据这些数据 ,我们计算出三个指标的敏感性和特异性分别为 :TS(10 0 %和 39%) ,ZPP(78%和 4 4 %)铁蛋白(5 6 %和 10 0 %)。由此我们推荐一种方法至少两个指标联合使用诊断缺铁性贫血 ,如 :铁蛋白和TS或铁蛋白和ZPP。     

Zinc protoporphyrin,a useful parameter to address hyperferritinemia

Zinc protoporphyrin (ZPP) is produced instead of heme as soon as iron support to erythropoiesis becomes insufficient. In iron deficiency the intra-erythrocytic ZPP concentration is increased. The aim of this study was to investigate whether ZPP is influenced by increased iron levels in hereditary hemochromatosis (HE) and is useful in the clarification of hyperferritinemia. Twenty HE patients and 160 patients with hyperferritinemic caused by anemia of chronic disorders, liver diseases, transfusional iron overload and hematologic or solid malignancies were enrolled. ZPP was measured using the Aviv front-face hematofluorometer (normal ≤ 40 μmol/mol heme). In HE, ZPP was significantly lower (median, 20 μmol/mol heme; p = 0.0005) compared to our historical control group. At diagnosis, 15 (75%) HE patients had ZPP values ≤25 μmol/mol heme. After phlebotomy, ZPP remained unchanged (median, 23 μmol/mol heme), although the initially high ferritin concentration decreased to normal. ZPP values in the other hyperferritinemic groups were significantly higher compared to HE and control groups. In contrast to HE, ZPP values ≤25 μmol/mol heme were only observed in 11% of cases with non-transfusional hyperferritinemia. The diagnostic accuracy of a ZPP ≤25 μmol/mol heme to detect HE in non-transfused hyperferritinemic patients was 87%, with a sensitivity of 75% and a specificity of 89%. Showing significantly lower values in HE, ZPP seems to be a useful parameter in distinguishing HE from other hyperferritinemic disorders as those conditions are generally accompanied by an increased ZPP.     

铅污染区儿童血铅与锌原卟啉、红细胞参数相关性研究

目的探讨铅污染区儿童血铅与锌原卟啉、红细胞参数相关性。方法对云南某县铅锌矿区和县城非铅锌矿区2～9岁儿童共464人进行血铅(BPb)水平、红细胞参数及锌原卟啉(ZPP)水平调查,按血铅水平分为高、低血铅组并进行血Pb与红细胞参数(RBC、HB、HCT、MCV、MCH、MCHC、RDW)及ZPP相关性分析。结果儿童血铅浓度均值154.4ugL,铅中毒率79.1%,ZPP均值2.7uggHb。血铅>250ugL时,血铅与红细胞参数具有相关性(RR:0.637)。高铅组血铅水平与RBC、ZPP有较强相关性(r分别为:-0.975、0.957)。RBC随血铅水平增高呈高度负相关,血铅水平<200ugL时,与ZPP无相关性。血铅水平达～250ugL、～300ugL、～350ugL时,血铅与ZPP具有较强相关性(r分别为:0.567、0.93、0.886)并呈高度正相关。结论随血铅水平的增高,RBC与血铅呈高度负相关,当血铅水平>250ugL时,血铅与ZPP具有高度正相关性,而当血铅水平<200ugL时,与ZPP相关关系不密切,因此ZPP不能作为铅中毒筛查指标。     

德州市3～6岁健康儿童锌原卟啉正常值调查

目的 :观察 3～ 6岁健康儿童锌原卟啉 (ZPP)及其与年龄、性别、血红蛋白 (Hb)的关系。方法 :采用血液荧光仪对不同托儿所和学前班的 4 5 4名儿童进行 ZPP和 Hb测定 ,然后进行统计学处理。结果 :4 11名健康儿童正常参考值为 (2 .6 4± 0 .9)μg/ g Hb,95 %上限为 4 .12μg/ g Hb,男性与女性儿童间无差异 (P>0 .0 5 ) ,各年龄组间有显著差异 (P<0 .0 1) ,且 6岁组最高 ,贫血儿童 ZPP亦增高 ,ZPP与 Hb呈负相关 (P<0 .0 5 )。结论 :ZPP可以作为儿童缺铁性贫血的筛查 ,各地区、各实验室及各年龄组应采用不同的正常值     

Effectiveness of zinc protoporphyrin/heme ratio for screening iron deficiency in preschool-aged children

Hemoglobin and zinc protoporphyrin (ZPP) tests are commonly used to screen for iron deficiency, but little research has been done to systematically evaluate the sensitivity and specificity of these two tests. The goal of this study was to evaluate the effectiveness of zinc protoporphyrin/heme (ZPP/H) ratio as a point-of-service screening test for iron deficiency among preschool-aged children by comparing the sensitivity and specificity of hemoglobin, ZPP/H ratio, and serum ferritin (SF). Also completed were assessments for the prevalence of anemia, iron deficiency (ID), and iron deficiency anemia (IDA) with indicators of ferritin models. This study was carried out with 95 children ages 3 to 6 y. Anthropometric measurements were assessed, and blood samples were analyzed for hemoglobin, SF, transferrin saturation (TS), and ZPP. Anemia was common and the prevalences of anemia, ID, and IDA were 14.7%, 12.6%, and 5.2%, respectively. The ZPP/H ratio was strongly and significantly correlated with hemoglobin. And ZPP/H ratio was a more sensitive test for ID than hemoglobin or SF measurement, correctly identifying more than twice as many iron-deficient children (sensitivity of 91.7%, compared to 41.7% for hemoglobin and SF). However, ZPP/H ratio had lower specificity (60.2%, compared to 89.1% for hemoglobin or 96.4% for SF) and resulted in the false identification of more subjects who actually were not iron deficient than did hemoglobin or SF. Low hemoglobin concentration is a late-stage indicator of ID, but ZPP/H ratio can detect ID at early stages and can be performed easily at a relatively low cost. Therefore, ZPP/H ratio can serve as a potential screening test for pre-anemic iron deficiency in community pediatric practices.