A study of the relationship between ambient lead and blood lead among lead battery workers

 Objective: To examine the relationship between ambient lead levels and blood lead levels and to explore the modifiers of the relationship between ambient lead and blood lead. Method: A cross-sectional study was conducted in two lead battery factories. Blood lead level and ambient lead concentration were measured for each participant concurrently. A structured questionnaire was administered to collect sociodemographic characteristics and occupational history. Design: Biological and personal environmental measurements of 219 lead-exposed workers were analyzed by both simple and multiple linear regression. A regression model was selected for interpretation. Results: A high correlation (r=0.62) between ambient lead (PbA) and blood lead (PbB) was observed. In addition, numerous factors, including age, sex, alcohol consumption, personal hygiene practice and type of lead exposure, were also found to influence blood lead levels. Although PbB was highly correlated with PbA, blood lead level may not be effectively lowered by reducing ambient lead level. Based on the regression coefficients, improvement of hygienic practice was more effective at lowering PbB than reducing ambient lead level. Good hygienic practice may be the preferential way to reduce lead exposure in current conditions. Conclusion: Education of correct work practice may be more important than engineering control in the developing countries to lower blood lead levels in lead battery factories. Received: 28 May 1996/Accepted: 30 August 1996     

普鲁卡因-安氟醚静吸复合全麻下硝酸甘油控制性降压对动脉血气的影响

以９例ＡＳＡⅠ～Ⅱ级、在普鲁卡因－安氟醚静吸复合全麻下择期手术的成人患者为对象，观察了硝酸甘油（ＮＴＧ）控制性降压（ＭＡＰ下降３０％）对动脉血气的影响。结果：与对照组相比，降压期间ＰａＯ２、ＢＥ明显下降，ＰａＣＯ２、Ｐａ－ｅｔＣＯ２明显升高。说明ＮＴＧ控制性降压可给血气带来不良影响。     

血压在前阻力血管中下降最快的原因分析

目的：解释血压在毛细血管前阻力血管中下降最快的原因。方法：利用物理模型简化复杂的心血管系统。结果：全身所有的微、小动脉段“并联”，全身所有的毛细血管段“并联”。结论：微、小动脉段的总流阻最大、使俐血压在微、小动脉中下降最快。     

成人原发性肾病综合征血容量与肾素,醛固酮,心钠素的关系

探讨成人原发性肾病综合征(NS)血容量与肾素、醛固酮及心钠素的关系。方法 应用~(113)mInCl标记转铁蛋白稀释法测定血容量,放免法测定血浆激素水平。对水肿期NS28例、正常26例及其中NS缓解期随访18例进行检测。结果 (1)水肿期NS血容量与正常组无差别,血浆肾素活性(PRA)、血管紧张素Ⅱ(ATⅡ)、醛固酮(Ald)、心钠素(ANP)水平均较正常组高,白蛋白、各激素水平与血容量无显著相关;(2)缓解期与水肿期比较,总的血容量无差异,Ald、ANP显著降低,PRA、ATⅡ则无明显差异;(3)Ald与24小时尿排钠(UNaV)显著负相关。结论 Ald和ANP是NS钠排泄的主要调节因子。     

离体不同时间血痕的肉眼和扫描电镜观察

对离体不同时间血痕进行肉眼和扫描电镜观察，获得了血痕形态结构变化的初步认识．结果随时间延长，血痕逐渐干燥、龟裂，电镜下纤维蛋白网消失，其超微结构变化观察有助于血痕经过时间的推断．     

抗—HCV阳性单采浆供血员HGV感染随访研究

为了解单采浆供血员庚型肝炎病毒（ＨＧＶ）感染及其转归，对１０２名抗－ＨＣＶ阳性单采浆供血员冻存血清进行抗－ＨＧＶ和ＨＧＶＲＮＡ检测，对抗－ＨＧＶ和（或）ＨＧＶＲＮＡ阳性者作３年随访研究。采用ＥＩＡ法检测抗－ＨＧＶ，包被抗原来自ＨＧＶ不同功能区的合成肽。应用ＲＴ－ＰＣＲ法检测ＨＧＶＲＮＡ，引物选自ＨＧＶＮＳ３区。结果表明，抗－ＨＣＶ阳性单采浆供血员ＨＧＶＲＮＡ阳性率为１９．６１％（２０／１０２），抗－ＨＧＶ阳性率为１７．６５％（１８／１０２），ＨＧＶ感染率（抗ＨＧＶ和／或ＨＧＶＲＮＡ阳性）为２４．５１％（２５／１０２），而对照组仅为０．９４％（１／１０６）。提示单采血浆是ＨＧＶ感染的重要危险因素。ＨＧＶＲＮＡ和抗－ＨＧＶ的３年阴转率分别为３５．００％（７／２０）和１１．１１％（２／１８），说明ＨＧＶ感染有慢性携带趋势     

Biocompatibility of Hemoglobin Solutions. II. The Inflammatory Reaction of Human Monocytes and Mouse Peritoneal Macrophages

This study explored the inflammatory mechanism of toxicity of hemoglobin solutions (Hb-S). Human monocytes and mouse activated peritoneal macrophages were incubated with seven different solutions. The first four consisted of non-cross-linked bovine Hb. Of these, Hb-SI was incompletely purified of stromal phospholipids, Hb-SII was contaminated with environmental bacterial endotoxins, Hb-SIII was pure hemoglobin, and Hb-SIV was pure Hb with the addition of superoxide dismutase (SOD), catalase (CAT), and mannitol (M). The other three solutions were made of pure bovine Hb cross-linked with different agents: Hb-SV, reacted with glutaraldehyde; Hb-SVI reacted with bis-3,5-dibromosalicyl fumarate (DBSF); and Hb-SVII reacted with a ring-opened dialdehyde derivative of 5'(pyro)-phosphate of adenosine (ATP) (o-ATP). The reaction of monocytes and macrophages was studied in terms of (a) O2-derived radicals, as determined by the measurement of H2O2 and lipid peroxides; (b) complement factor C3a desArg; (c) 6-keto-prostaglandin F1 alpha (stable metabolite of prostacyclin); and (d) TxB2 (stable metabolite of thromboxane) released into the culture supernatants. The most significant reactions were obtained with the solutions contaminated with stromal phospholipids or bacterial endotoxins. Pure Hb was less reactive. Further reduction in proinflammatory activity was achieved by the addition of oxygen radical-scavengers (SOD, CAT, and M), or by the cross-linking of Hb with DBSF or o-ATP.     

Plasma Separator for Encapsulating Fluorescent Probe in Erythrocytes

Using a plasma separator, it is possible to wash large volumes of whole blood free of plasma proteins in short periods. The novelty, however, is that the same apparatus can be used to reversibly hemolyze and reseal the red blood cells (RBCs) using hypotonic and hypertonic dialysates, respectively. This technique was assessed using the fluorescent exogenous agent uranin (fluorescein sodium). Results indicate that the encapsulation of the RBCs can be completed in under 2 h. The encapsulation efficiency of the RBCs was approximately 80% with a RBC recovery rate of 75%.     

Trans-scleral application of a semiconductor diode laser

We used a diode laser with an output power of 1 W through a fiberoptic light pipe (200 microns diameter) to deliver laser energy through the sclera of pigmented rabbits. Ciliary body destruction occurred with energy levels of 300-400 mW and exposure time of 0.5 sec. Retinal photocoagulation was achieved with energy levels of 200-500 mW in 0.5 sec. Histologic examination of acute lesions demonstrated thermal destruction of ciliary body processes and retina. Chorioretinal scar formation was observed clinically and histologically within 2-3 weeks. Our data indicate that the transscleral diode laser may be used for destruction of the ciliary body processes or peripheral retinal coagulation in pigmented eyes.     

Perioperative specific management of blood volume loss in craniosynostosis surgery

Accurate assessment and replacement of blood loss and fluid–electrolyte deficit during craniosynostosis repair is difficult owing to patient size and the diversity of surgical technique. Forty-three patients undergoing primary craniosynostosis repair over a 10-year period were studied retrospectively to determine blood loss and fluid deficit and to assess blood transfusion practices during both intraoperative and postoperative periods. Blood loss was calculated on the basis of estimated red cell mass (ERCM) and fluid-electrolyte imbalance was investigated with blood samplings. Blood transfusion was considered appropriate if the postoperative or posttransfusion ERCM was within 12% of the preoperative value. Estimated fluid requirement (EFR) was used in 4 ml kg^–1 h^–1 except for neonates. Intraoperatively, 80% of all patients were appropriately managed with respect to blood transfusion and EFR. Postoperatively only 20% of the patients receiving transfusions were transfused appropriately. In 23.3% of these patients (10/43) unexpected respiratory distress developed immediately after their recovery from the anesthesia. With the measurement of estimated blood volume and allowable blood loss, appropriate transfusion could be achieved for the successful treatment of the primary craniosynostosis. Received: 16 February 1998