三甲基氯化锡引发低血钾症的机制探讨

目的　探讨三甲基氯化锡(trimethyltinchloride,TMT)引发低血钾症的机制。方法　给SD大鼠腹腔注射TMT,观察血浆钾、钠、氯及红细胞内钾的水平,红细胞膜Na     

废旧塑料加工致急性三甲基氯化锡中毒4例分析

分析4例以低血钾为主要临床表现的患者资料,经对症治疗1例死亡,3例治愈.依据临床表现、实验室检查、毒物检测和现场调查确诊为职业性急性三甲基氯化锡(TMT)中毒.提示废旧塑料加工可致急性TMT中毒,以低钾血症及中枢神经系统损害为主,低钾血症是TMT中毒早期主要临床表现之一.     

三甲基氯化锡引发低血钾症动物模型的研究

目的 研究用三甲基氯化锡（TMT－Cl)引发低血钾症动物模型的方法。方法 给SD大鼠腹腔注射TMT－Cl,观察其半数致死剂量（LD50）以及血钾、血钠、血氯水平与TMT-Cl的剂量和染毒时间的关系。结果 TMT－Cl的LD50为14.7mg/kg。随着剂量的增加,血钾水平显著下降,死亡明显加快;10mg/kg组血钾随着染毒时间增加而不断下沉,至第6d达到最低为4.85mmol/L,第11d开始回升,但需到28d后才恢复至正常水平。血钾下降的速度及程度与中毒表现有关。染毒后0.5h动物血钠水平也明显下降,但24h后均恢复正常。结论 采用ＴＭＴ－Ｃl可以制作大鼠低血钾症动物模型。     

三甲基氯化锡作业工人生物学监测指标的研究

目的 探讨职业接触二甲基氯化锡(TMT-cl)作业工人的生物学监测指标.方法 利用气相色谱分析法,对发生TMT-cl中毒的5个企业接触TMT-cl的44名男性作业工人(接触组)和某食品厂50名工人(对照组)尿中TMT-cl水平和血清钾含量进行测定,并对使用的甲基硫醇锡热稳定剂或造粒料、废料中TMT-cl含量进行分析.结果 重、中、轻度TMT-cl中毒患者尿中均检出TMT-cl,分别为(0.869±0.392)、(0.963±0.482)、(0.716±0.384)μg/L,与对照组比较,差异有统计学意义(P＜0.01),尿中TMT-cl与病情严重程度无明显的平行关系(F=1.88,P＞0.05);TMT-cl重度中毒者第4天尿中TMT-cl与第1天比较,差异无统计学意义(P＞0.05),而中、轻度TMT-cl中毒者第4大尿中TMT-cl与第1天比较明显下降,差异有统计学意义(P＜0.01);第21天,重、中、轻TMT-cl中毒者尿中TMT-cl明显高于接触反应组,差异有统计学意义(P＜0.01).接触组低血钾发生率77.3%,明显高于对照组,差异有统计学意义(P＜0.01);接触组平均血钾水平低于正常参考值(3.5 mmol/L),与对照组比较,差异有统计学意义(P＜0.01),且血钾水平与病情严重程度存在平行关系(F=4.45,P＜0.05).接触组尿中TMT-cl与血钾呈负相关(r=-0.4456,P＜0.01).结论 尿中TMT-cl可作为TMT-cl中毒特异性接触指标;血钾可作为早期的生物监测指标,以发现早期中毒人群.     

使用甲基硫醇锡企业三甲基氯化锡职业中毒的调查分析

目的 探讨甲基硫醇锡PVC塑料稳定剂毒性及三甲基氯化锡(TMT)职业中毒原因.方法 利用气相色谱分析法对6种甲基硫醇锡中TMT含量进行分析;对8家使用甲基硫醇锡热稳定剂企业采用问卷法进行职业卫生调查.结果 6种甲基硫醇锡稳定剂中TMT含量除1种＜0.48 mg/kg外,其余5种为60.9～920 mg/kg,发生TMT中毒的3家企业使用的甲基硫醇锡其TMT占总锡≥0.2%,此时甲基硫醇锡成晶的毒性比不含TMT的成品毒性高254 mg/kg.使用甲基硫醇锡热稳定剂企业的人员对甲基硫醇锡热稳定剂的防护知识了解较少,防毒防尘设施较差.结论 尽快制定甲基硫醇锡热稳定剂中TMT限量标准(TMT占总锡＜0.20%)及使用量标准(＜1.2%),加强PVC加工企业的监督力度.     

回收废旧聚氯乙烯塑料导致三甲基氯化锡中毒事故的调查

目的调查1起由回收废旧塑料破碎作业导致三甲基氯化锡（TMT）中毒的原因。方法调查中毒者及其生产岗位、工艺，检测生产原料的TMT含量，分析中毒原因。结果回收废旧塑料中TMT含量达304．20mg/kg，破碎加热工艺可挥发出TMT，事故属于TMT中毒。结论回收塑料破碎作业可引起TMT中毒。     

废旧塑料加工致急性三甲基氯化锡中毒2例报告

目的 分析总结废旧塑料回收加工引起急性中毒的病因及其诊治经验.方法 对2例因回收加工废旧塑料引起的以低血钾为主要临床表现的急性中毒患者的临床资料进行分析.结果 经现场调查、毒物检测、临床表现、实验室检查,确诊为"急性三甲基氯化锡(TMT)中毒",对症治疗后均治愈.结论 废旧塑料加工可致急性TMT中毒;以低钾血症及中枢神经系统损害为主;有效纠正缺钾是救治的关键.     

一起职业性急性三甲基氯化锡中毒事故调查

目的通过调查分析1起由PVC塑料加工过程导致的三甲基氯化锡（TMT）中毒事故，以提出预防措施。方法调查中毒者临床表观及其生产岗位、工艺，检测生产原料TMT含量，分析中毒原因。结果该职业中毒事故系TMT中毒引起，其中职业性TMT中毒2人，职业性TMT接触反应2人。结论应改善PVC塑料加工过程中可致有机锡稳定剂挥发的诸工序局部排风和全面通风设施，加强上述工序员工的职业性健康检查工作。     

工作场所空气中三种氯化甲基锡的同时测定

目的 建立同时测定工作场所空气中三甲基氯化锡(TMT)、二甲基二氯化锡(DMT)和甲基三氯化锡(MMT)的测定方法.方法 工作场所空气中氯化甲基锡化合物用OVS管采样,用四乙基硼酸钠作为衍生剂,在pH为4.0±0.2的乙酸钠-冰醋酸缓冲液中,将极性的氯化甲基锡衍生成非极性的甲基乙基锡化合物,再用正己烷萃取,经毛细管分离,气相色谱-质谱法(GC/MS)定性和定量检测.结果 线性范围TMT为0.0528～26.3750 μg,DMT为0.2244～112.2000 μg,MMT为0.0526～26.3000μg;相关系数TMT为0.999 9,DMT为0.999 1,MMT为0.999 9;以采空气15 L计算最低检出浓度,TMT为0.001 mg/m3,DMT为0.002 mg/m3,MMT为0.0001 mg/m3.平均相对标准偏差(RSD)TMT为0.78%,DMT为2.57%,MMT为4.17%;平均回收率TMT为99.3%,DMT为97.8%,MMT为84.0%;平均采样效率TMT为99.3%,DMT为97.8%,MMT为84.0%;样品在室温中至少可保存7 d,在4℃下至少可保持14 d.结论 该方法适用于工作场所空气中3种氯化甲基锡的同时检测.     

三甲基氯化锡引起低血钾症的肾脏机制探讨

目的探讨三甲基氯化锡(trim ethyltin ch loride,TMT)引起低血钾症的肾脏机制。方法将SD大鼠随机分成3组,每组10只,分别经腹腔注射TMT 0、10.0、21.5 m g/kg,测定0.5 h、1 d、3 d、6 d和11 d血浆的钾。将大鼠随机分成2组,每组10只,分别经腹腔注射TMT 0、10.0 m g/kg,测定1 d、6 d和11 d的24 h尿量和尿钾浓度。将大鼠随机分成6组,每组10只,分别经腹腔注射TMT 0、10.0 m g/kg,测定1 d、6 d和11 d的肾小管上皮细胞膜钠钾ATP酶的活力。结果大鼠腹腔注射TMT 10.0、21.5 m g/kg后0.5 h,血钾显著下降(P<0.05),6 d和11 d血钾仍低于正常水平(P<0.05);给予TMT 10.0 m g/kg后1 d、6 d和11 d,尿量先增后减、尿排总钾均显著增加(P<0.05);1 d、6 d和11 d肾小管上皮细胞膜钠钾ATP酶活力均显著低于对照组(P<0.01)。结论TMT引起低血钾症的主要原因是肾脏排钾持续增多,其机制与TMT引起肾小管细胞膜钠钾ATP酶活力下降,进而引起K 的重吸收下降有关。     

有机锡塑胶制品加工业职业危害对工人健康影响

目的探讨塑胶制品行业职业危害因素对工人身体健康的影响。方法采用现场职业卫生学调查、工作场所职业病危害因素检测和职业健康体检相结合的方法,对该行业存在的职业病危害因素及其对工人身体健康的影响进行分析。结果粉尘、噪声均超过国家规定的职业接触限值,选择20个采样点测定三甲基氯化锡(TMT)空气中含量,平均0.008 6 mg/m3。职业健康检查发现,接触粉尘工人29.4%通气功能减退,11.9%小气道功能减退,17.5%双肺纹理增多、增粗,2.4%双肺散在小阴影。接触噪声工人17.9%语频听阈提高,74.4%高频听阈提高。接触TMT工人38.9%尿锡超标,42.1%血钾低。结论塑胶制品行业存在粉尘、噪声、TMT三种主要职业病危害因素,对工人身体健康造成严重影响。     

三甲基氯化锡对亚慢性染毒大鼠肾氢钾ATP酶活力及蛋白与基因表达的研究

目的 探索三甲基氯化锡(trimethyltin chloride,TMT)对亚慢性染毒大鼠肾氢钾ATP酶活力、蛋白和基因表达水平的影响.方法 取6周龄雌性SD大鼠55只,随机分成对照、低剂量、中剂量、高剂量和超高剂量组,共5组,每组11只,分别按0、8.20、32.81、131.25、262.50μg·kg-1·d-1的TMT剂量经饮水亚慢性染毒,14周后测定血钾水平,取大鼠肾脏,用定磷法测量氢钾ATP活力,用免疫印迹法测定肾氢钾ATP酶蛋白表达水平,用实时定量-聚合酶链反应法测定肾氢钾ATP酶的mRNA表达水平.结果 与对照组[(6.9±0.3)mmol/L]比较,超高剂量组血钾水平[(5.6±0.4)mmol/L]明显降低,差异有统计学意义(P＜.01).低剂量和超高剂量组氢钾ATP酶活力分别为(4.50±1.45)、(435±-0.72)μmolPi·mgprot-1·h-1,明显低于对照组[(6.55±0.77)μmolPi·mgprot-1·h-1],差异有统计学意义(P＜0.05).与对照组比较,超高剂量组氢钾ATP酶蛋白和mRNA表达水平差异均无统计学意义(P＞0.05).结论 TMT亚慢性接触可抑制氢钾ATP酶的活力,但不抑制该酶的蛋白和基冈表达.

Abstract：

Objective To study the activity、protein and gene expression of renal HK-ATPase (HKA) in rats subchronicly exposed to trimethyltin chloride (TMT). Methods In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 μg·kg-1 ·d-1 for 14 weeks.Then serum K+ levels were measured; the activities of H K-ATPase (HKA) in kidneys were detected by the method of determinenate phosphorus content;Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively. Results The serum K + level in super-high dosage group was (5.6±0.4) mmol/L, which was significantly lower than that [(6.9±0.3) mmol/L] in control group (P＜0.01).The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50±1.45 and 4.55±0.72 μmolPi·mg prot-1h-1, respectively, which were significantly lower than that (6.55±0.77 μmol Pi ·mg prot-1h-1) in control group (P＜0.05). Conclusion When rats were exposed subchronicly to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.     

ST段抬高型心肌梗死早期低血钾的临床意义

目的 探讨伴低血钾的急性心肌梗死(AMI)患者的临床特点和低血钾对预后的影响.方法 收集行急诊经皮冠状动脉介入治疗(PCI)的急性ST段抬高型心肌梗死患者216例,根据入院后即刻血钾水平分为A组(血钾＜3.5mmol/L,67例)和B组(血钾≥3.5mmol/L,149例).比较两组患者梗死部位、梗死相关血管及肌酸激酶同工酶MB(CK-MB)、心肌肌钙蛋白T(cTnT)峰值水平的差异,观察两组患者住院期间梗死后心绞痛、心律失常、心力衰竭及心脏性猝死的发生情况.结果 (1)A组广泛前壁、前壁梗死率和梗死相关血管为前降支率均高于B组[61.2%(41/67)比44.3%(66/149),55.2%(37/67)比38.9%(58/149)],差异有统计学意义(P=0.022、0.026).A组CK-MB、cTnT峰值高于B组[(194.39±101.27)μg/L比(115.35 ± 78.62) μg/L,(19.16 ± 11.48) μg/L比(9.07 ± 7.65) μg/L],差异有统计学意义(P=0.004、0.002).(2)A组左室射血分数低于B组(P=0.003),A组梗死后心绞痛、室性心动过速、心室颤动及心力衰竭的发生率[分别为 43.3%(29/67)、32.8%(22/67)、11.9%(8/67)、37.3%(25/67)]均高于B组[分别为24.8%(37/149)、18.1%(27/149)、4.0%(6/149)、20.8%(31/149)],差异有统计学意义(P=0.006、0.017、0.029、0.010).结论 低血钾与AMI患者的梗死部位、梗死相关血管有关,并影响患者的预后.

Abstract：

Objective To investigate clinical characteristics of patients with ST-elevation myocardial infarction (STEMI) and hypokalemia and the effects of hypokalemia on prognosis. Methods Consecutive 216 cases with STEMI who underwent emergency PCI were divided into group A (serum potassium ＜ 3.5 mmol/L) and group B (serum potassium＞3.5 mmol/L). Infarct site, infarct interrelated artery, peak level of CK-MB and cTnT were compared between two groups. Post-infarctional angina pectoris, arrhythmia, heart failure and cardiac death were compared. Results (1 )The percentage of anterior wall myocardial infarction , left anterior descending artery (LAD) lesions in group A were significantly higher than those in group B [61.2%(41/67) vs. 44.3%(66/149),55.2%(37/67)vs. 38.9%(58/149),P = 0.022,0.026]. The peak levels of CK-MB and cTnT in group A were significantly higher than those in group B [(194.39 ± 101.27) μg/L vs. (115.35 ±78.62)μg/L,(19.16 ±11.48)μg/L vs. (9.07 ±7.65) μg/L,P = 0.004,0.002].(2)Left ventricular ejection fraction in group A was significant lower than that in group B (P - 0.003). The incidence rates of post-infarctional angina pectoris, ventricular tachycardia, ventricular fibrillation and heart failure were significantly higher in group A [43.3%(29/67),32.8%(22/67), 11.9%(8/67),37.3%(25/67)] than those in group B [24.8%(37/149),18.1%(27/149),4.0%(6/149),20.8%(31/149)](P = 0.006, 0.017, 0.029, 0.010). Conclusions Hypokalemia is associated with infarct site and infarct interrelated artery. Hypokalemia has bad effect on prognosis of STEMI.     

Serum potassium testing in diuretic-treated outpatients. A multivariate approach

We evaluated risk factors for abnormal serum potassium (K+) concentrations in 5817 outpatients on chronic diuretic therapy. Hypokalemia (K+ less than 3.5 meq/L) occurred in 18.8 percent at the last clinic measurement. Hyperkalemia (K+ greater than 5.5) was rare (0.5%) and was even less common in those also taking KCl or a K+ sparing drug (0.2%). Hypokalemic patients were younger, healthier, more often hypertensive, more commonly taking a thiazide diuretic, and more likely to have been hypokalemic in the past. Hyperkalemic patients were older, more often suffering from heart or renal failure, and more commonly taking furosemide. Logistic regression analysis yielded eight variables that contributed significantly to the prediction of hypokalemia: mean and most recent serum K+, thiazide use, the use and duration of use of potassium-sparing diuretics, age, and most recent serum sodium and bicarbonate determinations. The regression equation allowed us to identify a group of patients (63% of the total) at low risk for hypokalemia (K+ less than 3.5 in 9.4%; K+ less than 3.0 in 0.5%) and another group (37% of the total) at high risk for hypokalemia (K+ less than 3.5 in 35%; K+ less than 3.0 in 5%). Information about the risk of hypokalemia can be used to decide when to measure serum potassium concentration in individual diuretic-treated outpatients.     

Toxicity of Trimethyltin and Dimethyltin in Rats and Mice

Extensive uses of methyltin compounds in polyvinyl chloride (PVC) production have led to a dramatic increase of occupational-related methyltin poisoning accidents and the widespread contamination of methyltins in various environmental media. Here, we conducted studies to compare the acute toxicity induced by trimethyltin (TMT) and dimethyltin (DMT), and investigated the cumulative toxic effects of TMT in rats and mice. Neurobehavioral changes were observed in rats and mice treated with either DMT or TMT, but we also observed that both TMT and DMT exposure in rats significantly lowered the blood potassium level. Moreover, the cumulative toxic coefficient factor of TMT was 1.7 in rats versus 3.8 in mice, suggesting a high cumulative risk for rats and a moderate risk for mice. In summary, we demonstrated that acute and chronic exposure to methyltin compounds induced neurotoxicity and hypokalemia. Moreover, our study suggests that TMT can accumulate in the body and pose a risk for workers chronically exposed to a low dose of TMT.     

孕早中期唐氏综合征筛查及297例介入产前诊断数据分析

目的:探索一种有效的产前筛查唐氏综合征和其他严重出生缺陷儿的方法及各血清标志物筛查的截断界值。方法:应用时间分辨荧光免疫分析技术,对4762例孕妇进行血清标志物(PAPP-A/freeβ-hCG或者AFP/freeβ-hCG/μE3)联合筛查,使用Multical软件筛查高风险对象,通过羊水或脐带血细胞培养获得染色体核型给予诊断。结果:①筛查随访的2602例孕妇中,筛查出唐氏综合征及18三体高风险140例,NTD高风险17例,单项指标异常574例。共发现唐氏综合征10例、18三体4例、13三体2例、45,X3例、臂间倒位2例、缺失3例、遗传多态5例;重型地贫2例、无脑畸形1例、先天性肾病综合征1例。②血清标志物联合筛查的灵敏度、特异度、假阳性率、假阴性率分别为56.52%、94.41%、5.59%、43.48%;仅用PAPP-A作为独立指标筛查的灵敏度、特异度、假阳性率、假阴性率分别为100.00%、95.81%、4.19%、0;仅用AFP作为独立指标筛查的灵敏度、特异度、假阳性率、假阴性率分别为37.50%、90.84%、9.16%、62.50%;仅用freeβ-hCG作为独立指标筛查的灵敏度、特异度、假阳性率、假阴性率分别为33.33%、87.16%、12.84%、66.67%。③μE3的诊断界点为≤0.733MoM时可筛查出50%的唐氏综合征,假阳性率为9.36%;AFP的诊断界点为<0.6MoM时可筛查出40%的唐氏综合征,假阳性率为8.40%;若AFP的诊断界点为≤0.7MoM时可筛查出70%的唐氏综合征,假阳性率为19.40%;freeβ-hCG的诊断界点为<0.4MoM可筛查出75%的18三体病例,假阳性率为4.00%;freeβ-hCG的诊断界点为≥1.8MoM可筛查出40%的21三体病例,假阳性率为18.60%;freeβ-hCG的诊断界点为≥1.7MoM可筛查出50%的21三体病例,假阳性率为21.90%。以假阳性率5.00%为标准,freeβ-hCG的诊断界点为≥3.0MoM可筛查出10.00%的21三体病例。结论:血清标志物联合筛查的效率高于单项指标,但对血清标志物单项筛查阳性者也要建议产前诊断。唐氏综合征筛查是预测不良妊娠结局的有效指标,结合产前诊断对防止先天缺陷有实用价值。     

Feasibility of baculovirus-expressed recombinant 10-kDa antigen in the serodiagnosis of Taenia solium neurocysticercosis

Bacterially expressed recombinant 10-kDa protein of Taenia solium metacestode (TsM) was previously found to be reliable in the diagnosis of active stage neurocysticercosis (NCC) by immunoblotting but not by ELISA. In this study, we evaluated the diagnostic feasibility of detecting eukaryote-expressed recombinant 10-kDa protein of TsM by ELISA (rTsM10-ELISA) in the serum and cerebrospinal fluid (CSF) from NCC patients. In 45 cases of active NCC, 91.1 and 97.8% cases showed positive reactions for serum and CSF by rTsM10-ELISA. ELISA employing the crude cyst fluid antigen (CF-ELISA) also revealed a similar result. Negligible cross-reactions were observed in serum samples from control subjects and from subjects with other helminthic diseases by rTsM10-ELISA (5/139 cases, 3.6%). By contrast, CF-ELISA demonstrated a high degree of cross-reactivity (24/139, 17.3%) especially from those patients with alveolar and cystic echinococcoses. The overall sensitivity and specificity of rTsM10-ELISA were 94.3 and 96.4%; and those of CF-ELISA were 95.7 and 84.5%, for serum and CSF, respectively. Antibody responses to rTsM10 were detected as early as 3 months after experimental infection of T. solium eggs in pigs. Our results show that ELISA with rTsM10 could be highly applicable in the serodiagnosis of NCC from early stage of infection.     

血管紧张素转换酶抑制剂对血清钾水平的影响

[目的]观察肾功能不全的病人应用血管紧张素转换酶抑制剂(ACEI)时血清钾的水平。[方法]将病人分成肾功能正常组和肾功能不全组,二组病人都口服依那普利5mg/d。有11例因水肿同时口服安体舒通40~60mg/d。在口服前和口服后1.5个月分别作血清钾测定。在肾功能不全组的病人出现血清钾升高后改服氨氯地平5mg/d。[结果]在口服依那普利5mg/d后,肾功能不全组的血清钾水平高于肾功能正常组,改服氨氯地平5mg/d后血清钾恢复正常。Logistic回归分析显示,同时口服安体舒通和肌酐水平是引起血清钾升高的危险因素。[结论]肾功能不全组病人在口服依那普利5mg/d后血清钾高于肾功能正常组。在服用ACEI时必须监测血清钾浓度。