正交设计评价吸附剂清除百草枯和敌草快的体外试管实验

  目的  通过体外试管实验方法，评价消化道吸附剂清除百草枯和敌草快的效果。
  方法  通过正交设计以体外试管实验探索毒物质量浓度、吸附剂种类、反应时间和酸碱度4个因素对百草枯和敌草快清除能力的影响。
  结果  吸附剂种类、反应时间和酸碱度对百草枯和敌草快清除率的影响差异有统计学意义（P < 0.05）。对百草枯清除率影响程度大小的顺序为吸附剂种类>反应时间>酸碱度；对敌草快清除率影响程度大小的顺序为吸附剂种类>酸碱度>反应时间。上述因素清除百草枯和敌草快的最佳组合为pH=12的环境下，采用蒙脱石散为吸附剂、反应时间120 min。
  结论  体外试管实验条件下，常用吸附剂蒙脱石散、活性炭粉和捣碎的药用炭片均可有效清除百草枯和敌草快。吸附剂种类、反应时间和酸碱度对百草枯和敌草快的清除率均有影响。
     

血液透析联合血液灌流治疗急性百草枯中毒疗效meta分析

目的 分析血液透析联合血液灌流医治急性百草枯中毒的疗效。
方法 通过检索CBMdisc、CNKI、CHKD、万方、维普、PubMed、Embase等国内外数据库近16年公开发表的血液透析联合血液灌流治疗百草枯中毒的相关论文, 使用RevMan 5.3软件对结果进行meta分析。
结果 共检索出文献317篇, 9篇文献纳入。共计543例患者, 其中血液透析联合血液灌流治疗组(治疗组)308例, 死亡90例, 常规治疗组(对照组)235例, 死亡156例。各研究间同质性较好(χ2=5.96, DF=8, P>0.05, I2=0%), 疗效的合并OR值=0.19(95% CI为0.13~0.28, Z=8.51, P < 0.01)。
结论 血液透析联合血液灌流医治急性百草枯中毒相比常规治疗, 可显著降低死亡率。但确切疗效还需考虑其他多种因素, 需要更多数据, 在临床上进一步探究。
     

前处理步骤对微波消解-原子荧光光谱法测定尿硒的影响

目的 探讨微波消解-原子荧光光谱法测定尿硒的前处理步骤中酸的种类、浓度、添加剂（包括硫脲-抗坏血酸、铁氰化钾）对测定结果的影响,为开发尿硒测定方法提供依据。
方法 通过比较不同浓度的硝酸溶液和盐酸溶液、不同浓度硫脲-抗坏血酸溶液、添加铁氰化钾溶液对尿硒测定结果的影响,来优化微波消解-原子荧光光谱法测定尿硒的前处理步骤。
结果 随着硝酸浓度的提高,尿样定容液硒荧光值先升后降,而使用含体积分数5%~30%盐酸的水溶液时,硒荧光值较稳定;无须加入硫脲-抗坏血酸或铁氰化钾,如遇非硒金属干扰测定可用体积分数30%盐酸溶液定容来消除。优化后的方法回收率为84.07%~85.28%,精密度为0.95%~2.29%。
结论 所得的实验条件优化了微波消解-原子荧光光谱法测定尿硒的前处理方法,可为同行开发尿硒的测定提供参考。
     

电感耦合等离子体发射光谱法测定工作场所空气中铅及其无机化合物

目的 提高铅及其无机化学物分析方法的灵敏度。
方法 用电感耦合等离子体发射光谱法对工作场所空气中铅及其无机化合物进行测定。
结果 本法的分析范围为0.005~1.00 μg/mL, 线性相关系数为1.000(P < 0.05), 相对标准偏差为0.62%~0.96%, 回收率达到95.8%~100%, 待测样品在室温下至少可以存放7 d。
结论 该法具有快速准确、操作简便、灵敏度高、检出限低等优点, 弥补了现有检测方法灵敏度达不到实际要求, 实验步骤过于烦琐而无法适用于大量样品分析等不足。
     

名词小词典

毒物代谢动力学　　毒物代谢动力学 (toxicokinetics)是一门毒理学的分支科学,它应用药物代谢动力学的基本原理和方法,通过建立数学模型来定量的阐述外来化合物在机体内吸收、分布、生在体内随时间变化含量在不断改变的动态规律,计算出其各项基本参数。基本参数包括峰值浓度、消除速率常数、半衰期、曲线下面积、清除率和表观分布容积等。血液灌流　　血液灌流 (hemoperfusion,HP)是临床常用的血液净化方法之一,它通过将患者的血液从体内引出经过体外循环,利用体外循环灌流器中吸附剂的吸附作用清除外源性和内源性毒物、药物以及代谢产物等…     

血液灌流

血液灌流(hemopefusion，HP)是临床常用的血液净化方法之一，它通过将患者的血液从体内引出经过体外循环，利用体外循环灌流器中吸附剂的吸附作用清除外源性和内源性毒物、药物以及代谢产物等，从而达到净化血液的目的。常用的吸附剂有活性炭和吸附树脂。     

血液灌流救治5例急性铊中毒护理体会

血液灌流(hemoperfusion,HP)是临床常用的血液净化方法[1]。通过穿刺等方式将患者的血液从体内引出进行体外循环,利用体外循环灌流器中吸附剂的作用清除外源性和内源性毒物、药物以及代谢废产物等,从而达到净化血液的     

电感耦合等离子质谱法检测工作场所空气中铟及其化合物

目的 采用电感耦合等离子体质谱技术, 建立工作场所空气中低浓度铟(In)及其化合物的检测方法。
方法 采用微孔滤膜采集工作场所空气中的In及其化合物, 5mL硝酸作为消解液, 电热板加热消解样品后, 电感耦合等离子体质谱(ICP-MS)定量检测。
结果 在选定的范围内, 铟及其化合物的浓度与铟和内标铑响应值的比值具有良好的线性关系, 相关系数大于0.999。以采样体积75L计, 检出限为0.33μg/L, 最低检出浓度为1.11×10-4mg/m3, 加标回收率为99.7%~103.7%, 相对标准偏差(RSD)为0.78%~4.64%。
结论 建立的方法检出限低、灵敏度高、简单、快速、准确, 适用于工作场所空气中低浓度铟及其化合物的检测。
     

个人剂量监测能力考核不合格原因分析

目的 查找个人剂量监测能力考核不合格原因, 确保日后个人剂量监测数据的准确可靠, 提高监测能力。
方法 参加中国疾病预防控制中心辐射防护与核安全医学所组织的2017年度全国个人剂量监测能力考核, 根据五组盲样考核的结果, 参照能力考核方案的方法对不合格原因进行分析和实验验证。
结果 五组考核结果中, 2组X射线照射的单组性能|P_i|>0.30, 3组γ射线照射的单组性能|P_i| < 0.30, 单组性能考核结果不合格, 整体能力考核不合格。验证实验显示, 使用的剂量盒与采用的刻度因子一致可使X射线照射的单性能|P_i| < 0.30。
结论 刻度因子的正确选用非常重要, 对个人剂量监测系统有很大的影响。
     

溶剂解吸-气相色谱法对工作场所空气中正戊醇检测方法研究

目的 建立工作场所空气中正戊醇溶剂解吸-气相色谱检测的方法。
方法 溶剂解吸-气相色谱法, 以正丁醇-二硫化碳溶液(体积比1:100)作为解吸液, 采用0.32 mm×30 m FFAP毛细管气相色谱柱、氢火焰离子化检测器(flame ionization detector, FID)对正戊醇进行检测。
结果 本方法正戊醇的检出限为1.3 μg, 相关系数r>0.999, 精密度为2.4%~7.7%, 不同浓度回收率在96.1%~101.1%之间, 采样效率100%, 解吸效率为92.3%, 正戊醇穿透容量>6.1 mg; 样品在常温下可保存7 d。
结论 该方法操作方便, 准确可靠, 可以用于工作场所空气中正戊醇的测定。
     

床边血液灌流治疗急性甲胺磷中毒研究

目的 探讨血液灌流(HP)对甲胺磷中毒患者体内毒物的清除效果.方法 在综合治疗的基础上,对15例重度急性甲胺磷中毒患者予以HP治疗,在HP前,HP开始后5、15、30、45、60 min及HP结束时(120 min)共7个时间点分别采集患者外周静脉血5 ml,测定血清中甲胺磷浓度及血清胆碱酯酶活力,并测定HP后灌流器吸附的甲胺磷含量.结果 15例患者存活12例,死亡3例.55例中毒患者HP前血胆碱酯酶活力为(662.60±632.05)IU/L,HP后血胆碱酯酶活力为(2577.52±920.38)IU/L,灌流前后血胆碱酯酶活力的差异有统计学意义(P<0.01).HP治疗后第45、60、120 min时患者血中甲胺磷浓度分别为(851±672)、(680±529)、(587±520)μg/ml,明显低于HP前(1659±1105)μg/ml,差异有统计学意义(P<0.01).灌流器吸附甲胺磷含量阳性.结论 HP可以明显降低甲胺磷中毒患者血清中毒物浓度,实验方法直接证明了临床应用HP的碳肾确能吸附甲胺磷.

Abstract：

Objective To explore the effect of hemoperfusion(HP) about the pacients of methamidophos poisoning.Methods On the basis of comprehensive treatment,15 cases of severe acute methamidophos poisoning patients were treated with HP,Blood samples were collected at 7 time points,before and 5,15,30,45,60mins following the beginning and the end of hemoperfusion.Blood samples were used for measuring the concentration of methamidophos and perfusion devices were used for measuring the volume of methamidophos adsorbed by the device after hemoperfusion.Results 15 patients live in 12 cases,3 cases of death.HP (former) blood Cholinesterase vigor were 662.60 + 632.05,HP (after) blood cholinesterase vigor were 2577.52 + 920.38 IU/L;The difference of blood Cholinesterase vigor between the before and after HP was statistically significant (P < 0.01).The patients' methamidophos concentration of blood when HP treated 45,60,120 min were respectively (851 + 672),(680 + 529),(587 + 520) μg /ml,there were significantly lower than that the patients' methamidophos concentration of blood who were before HP (1659 +1105) μg/ml,a statistically significant difference (P<0.01).Conclusion HP can be cut down obviously methamidophos poisoning patients serum concentrations of toxic,the experimental method directly prove the clinical application of carbon HP can really adsorption methamidophos.     

人外周血淋巴细胞体外乙酸铅染毒后氧化应激损伤研究

目的 研究乙酸铅染毒人外周血淋巴细胞致氧化应激与DNA氧化损伤情况。
方法 分别用浓度为0 μmol/L、20 μmol/L、40 μmol/L和80 μmol/L的乙酸铅染毒人外周血淋巴细胞6 h、12 h、24 h, 应用2', 7'-二氯二氢荧光素二乙酸酯(DCFH-DA)染色分析和流式细胞仪检测染毒后细胞内活性氧类(ROS)水平, 高度水溶性四唑盐(WST-1)法检测染毒后细胞内总超氧化物歧化酶(T-SOD)活性, 酶联免疫吸附测定法(ELISA)试剂盒检测染毒后细胞8-羟基脱氧鸟苷(8-OHdG)水平, 并对ROS、T-SOD、8-OHdG三指标间的关系进行相关性分析。
结果 乙酸铅染毒6 h后, 各染毒组人外周血淋巴细胞ROS水平均高于对照组, 差异有统计学意义(P < 0.01);20 μmol/L染毒组人外周血淋巴细胞T-SOD和8-OHdG水平与对照组相比, 差异无统计学意义(P>0.05), 而40 μmol/L和80 μmol/L染毒组人外周血淋巴细胞T-SOD和8-OHdG水平均高于对照组, 差异有统计学意义(P < 0.01)。乙酸铅染毒12 h和24 h后, 各染毒组人外周血淋巴细胞ROS、T-SOD和8-OHdG水平均高于对照组, 差异有统计学意义(P < 0.01)。相关性分析显示, 细胞内ROS含量与T-SOD活性呈负相关(r_{6 h}=-0.865、r_{12 h}=-0.890、r_{24 h}=-0.801, P < 0.01), 与8-OHdG含量呈正相关(r_{6 h}=0.840、r_{12 h}=0.829、r_{24 h}=0.866, P < 0.01)。
结论 乙酸铅染毒人外周血淋巴细胞后会诱导细胞ROS生成, 抑制细胞内抗氧化酶SOD活性, 造成人外周血淋巴细胞氧化应激状态增强和DNA氧化性损伤。
     

某蓄电池厂作业工人血铅、尿铅与指甲铅检测结果分析

目的 通过对某蓄电池厂工作人员血铅、尿铅及指甲铅水平的分析, 探讨三者在职业病诊断中的价值。
方法 留取该企业203名作业工人静脉血标本、尿标本以及指甲标本, 用石墨炉原子吸收光谱法测定血铅、尿铅以及指甲铅水平, 并对数据进行统计学分析。
结果 该企业铅烟时间加权平均浓度(C_TWA)为(0.31 ±0.37) mg/m3, 铅尘C_TWA为(0.28 ±0.50) mg/m3。员工血铅均值为(280.37 ±164.86)μg/L, 异常率为22.7%;尿铅均值为(0.035 ±0.042) mg/L, 异常率为11.3%;指甲铅均值为(1 407.96 ±2 625.26)μg/g。男性工人血铅、尿铅、指甲铅水平均高于女性工人, 差异有统计学意义(P < 0.01或0.05)。不同工龄组工人血铅、尿铅异常率差异均无统计学意义(P>0.05)。血铅、尿铅水平和指甲铅水平均存在相关关系(r=0.544、0.546, P < 0.01)。
结论 该蓄电池厂铅作业工人血铅、尿铅、指甲铅均有异常, 指甲铅和血铅水平有较好的相关性。指甲铅水平可作为职业性慢性铅中毒诊断的一个辅助指标, 值得进一步探讨。
     

火焰原子吸收光谱法测定工作场所空气中镉及其化合物含量的不确定度评定

[目的]探讨火焰原子吸收光谱法测定工作场所空气中镉及其化合物含量的不确定度评定方法。[方法]依据国家职业卫生标准GBZ/T 160.5-2004和JJF 1059.1-2012的原理和方法,对不确定度的分量进行计算。[结果]采集75 L和120 L标准采样体积引入的相对不确定度分别为0.008 4、0.004 8,标准溶液及配制过程引入的不确定度为0.006 6,标准曲线拟合引入的相对不确定度为0.025 8,样品制备过程引入的相对不确定度为0.030 0,样品重复测定引入的相对不确定度为0.001 5。合成相对标准不确定度为0.041 9,测定工作场所空气中镉及其化合物浓度为0.067 mg/m^3,扩展不确定度为0.005 mg/m^3(k=2)。样品溶液制备过程、拟合标准曲线和标准采样体积是本方法不确定度的主要来源,其他分量相对很小。样品溶液制备过程中样品消解过程引入的不确定度对合成不确定度的贡献最大。[结论]在试验中,要注意减少样品前处理损失,选择高纯度标准液、标准物,加强前处理和标准曲线拟合等步骤的质量控制,减少测量结果的不确定度,保证试验数据的准确性、可靠性。     

Oral and dermal absorption of chlorpyrifos: a human volunteer study

OBJECTIVES: To determine the kinetics of elimination of urinary dialkylphosphate metabolites after oral and dermally applied doses of the organophosphate pesticide chlorpyrifos to human volunteers and to determine whether these doses affected plasma and erythrocyte cholinesterase activity. METHOD: Five volunteers ingested 1 mg (2852 nmol) of chlorpyrifos. Blood samples were taken over 24 hours and total void volumes of urine were collected over 100 hours. Four weeks later 28.59 mg (81567 nmol) of chlorpyrifos was administered dermally to each volunteer for 8 hours. Unabsorbed chlorpyrifos was washed from the skin and retained for subsequent measurement. The same blood and urine sampling regime was followed as for the oral administration. Plasma and erythrocyte cholinesterase concentrations were determined for each blood sample. The concentration of two urinary metabolites of chlorpyrifos--diethylphosphate and diethyl-thiophosphate--was determined for each urine sample. RESULTS: The apparent elimination half life of urinary dialkylphosphates after the oral dose was 15.5 hours and after the dermal dose it was 30 hours. Most of the oral dose (mean (range) 93% (55-115%)) and 1% of the applied dermal dose was recovered as urinary metabolites. About half (53%) of the dermal dose was recovered from the skin surface. The absorption rate through the skin, as measured by urinary metabolites was 456 ng/cm2/h. Blood plasma and erythrocyte cholinesterase activity did not fall significantly during either dosing regime. CONCLUSION: An oral dose of chlorpyrifos was readily absorbed through the skin and almost all of the dose was recovered as urinary dialkylphosphate metabolites. Excretion was delayed compared with the oral dose. Only a small proportion of the applied dose was recovered during the course of the experiment. The best time to collect urine samples for biological monitoring after dermal exposure is before the shift the next day. The amounts of chlorpyrifos used did not depress acetyl cholinesterase activity but could be readily detected as urinary dialkylphosphate metabolites indicating that the urinary assay is a more sensitive indicator of exposure.

 

     

Heterogeneity of small intestinal microcirculation

INTRODUCTION: Microcirculatory disorders play important roles in the impairment of the mucosal barrier of the small intestine. Circulatory failures may increase the heterogeneity of microvascular perfusion, however, conventional methods are inadequate to describe an evolving heterogeneity in time or space. The authors aims were to examine and characterize the microcirculatory reactions in the mucosa and longitudinal muscle of the small intestine in clinically relevant experimental models of circulatory disorders. METHODS: Intravital videomicroscopy with orthogonal polarization spectral imaging technique was used to visualize the microcirculation. A mathematical approach was applied to describe the temporal variability in perfusion based on the calculation of average red blood cell velocity from the relative time periods of observed velocity, while spatial heterogeneity was calculated as a function of the perfused area. The authors' experiments were performed after 1. sham operation, 2. during hemorrhagic shock and crystalloid resuscitation, 3. during 2-hr endotoxin infusion, 4. in response to nitric oxide synthesis inhibition, and 5. after superior mesenteric artery occlusion and reperfusion. RESULTS: During hemorrhagic shock a fluctuating flow pattern appeared in the mucosa, the average red blood cell velocity decreased by 40% in the villi and by 60% in the muscle. Ischemia caused 20% flow reduction in both layers, while endotoxin caused a temporary 20% decrease in the mucosa, and a persistent, over 25% decrease in the muscle layer. Nitric oxide synthesis inhibition resulted in a 40% decrease in both structures. CONCLUSIONS: Heterogeneity of microcirculatory perfusion may appeared both spatially (between or within anatomical layers) and in time (periodically) after the insults. A redistribution of blood flow favouring the mucosa evolves in the small intestine after systemic circulatory disorders. Heterogenous perfusion-related microcirculatory changes can be characterized with mathematical approaches, and these calculations should be taken into account during the comparison of the consequences of distinct circulatory failures involving the small intestine.     

Urinary excretion of diethylphosphorus metabolites in persons poisoned by quinalphos or chlorpyrifos

The urinary excretion rates of diethyl phosphate and diethyl phosphorothioate and changes in blood cholinesterase activities were studied in fifteen persons self-poisoned either by the organophosphorus pesticide quinalphos (twelve persons) or by chlorpyrifos (three persons). The organophosphate poisoning was always indicated by a significant depression of serum and/or red blood cell cholinesterase activities. The return of serum cholinesterase activity in the range of referent values took more than 30 days and had a different course in different persons. The most rapid increase in red blood cell acetylcholinesterase activity was noted within 24 h after the first treatment with oximes Pralidoxime and/or HI-6. None of the spot urine samples, collected daily after admission of persons to hospital, contained measurable quantities of the parent pesticide. There was no correlation between the maximum concentration of total urinary diethylphosphorus metabolites normalized to creatinine and the initial inhibition of blood cholinesterase activities measured in samples collected on the day of admission to hospital. The excretion of metabolites followed the kinetics of a biphasic reaction. The half-time of urinary metabolites concentration decrease in the fast excretion phase in quinalphos poisoned persons was 5.5–14.2 h (eight persons) and 26.8–53.6 h (four persons) and in chlorpyrifos poisoned persons 3.5–5.5 h. The half-time for the slow excretion phase ranged from 66.5 to 127.9 h in all persons and for both compounds. For a given person, the rates of excretion of diethyl phosphate and diethyl phosphorothioate were about the same. However, in quinalphos poisoned persons the proportions of single metabolites in total diethylphosphorus metabolites varied with the initial maximum concentration of total metabolites. Simultaneous determination of both metabolites gave a more reliable and sensitive confirmation of absorption and retention of quinalphos and chlorpyrifos in the body.     

孕中期妇女体力活动与血糖代谢的关联性

目的探究孕中期体力活动与血糖水平及妊娠期糖尿病(gestational diabetes mellitus,GDM)的关联。方法采用横断面调查的方法,于2017-2018年在广州市纳入孕周在20~28周的孕妇1083人。采用面对面调查收集一般人口学和生活方式等资料,采用国际体力活动问卷调查过去一周的体力活动,通过口服葡萄糖耐量试验(oral glucose tolerance test,OGTT)测量孕妇血糖和诊断GDM。运用多重线性回归和Logistic回归分析模型分别探讨不同类型体力活动和静坐行为与血糖及GDM的关联。结果36.57%的孕妇体力活动达到推荐值(中高体力活动≥150 min/week)。多重线性回归结果表明,孕中期妇女总体力活动强度与OGTT-2 h血糖水平呈负相关关系(β=-0.10,P=0.017);运动锻炼和休闲体力活动强度与OGTT-1 h血糖呈负相关(β=-0.11,P=0.042),未发现其他类型体力活动或静坐时间与血糖之间的关联。Logistic回归分析模型分析未发现各类型体力活动或静坐时间与GDM风险之间的关联。结论孕中期妇女体力活动水平较低,近2/3妇女未达到推荐值。孕中期妇女总体力活动、运动锻炼和休闲体力活动有助于降低餐后血糖。