Comparison of urinary thallium levels in non-occupationally exposed people and workers

Purpose

To determine a reference background urinary thallium level; to compare urinary thallium data from workers to this background level; to investigate factors affecting these levels and whether creatinine correction is appropriate.

Methods

Urine samples from non-occupationally exposed people (n = 273, from 113 individuals) and workers (n = 896, from 447 individuals) were analysed for thallium by ICP-MS. A reference background level was calculated, defined as the 95th percentile value of a non-occupationally exposed population. Worker data were divided into two subsets: thallium workers (those who work directly with thallium or its compounds) and general workers; and compared to the background level. Bayesian linear mixed effects modelling was used to investigate factors affecting urinary thallium concentration and the efficacy of creatinine correction for the determination of urinary thallium.

Results

The reference background urinary thallium level is 0.27 μmol/mol creatinine (creatinine-corrected) or 0.40 μg/l (uncorrected). Median values were 0.11 μmol/mol creatinine or 0.17 μg/l for non-occupationally exposed people, 0.12 μmol/mol creatinine or 0.20 μg/l for general workers and 0.19 μmol/mol creatinine or 0.41 μg/l for thallium workers. Variation was lower in creatinine-corrected models. Nine per cent of samples from general workers and 39 % of samples from thallium workers exceeded the creatinine-corrected background level. By 2010, 90 % of all workers had urinary thallium levels below the 95th percentile reference background level.

Conclusions

Urinary thallium concentrations were higher in thallium workers than non-occupationally exposed people and general workers. Creatinine correction is appropriate.     

胃、结直肠癌术前区域性动脉化疗几个相关问题

胃、结直肠癌根治性切除术复发转移是严重影响术后5 a生存率提高的重要原因.以手术为主综合治疗已成为新的趋势,其中术前区域性动脉化疗(preoperative regional-arterial chemotherapy,PRAC)尤为值得重视.本文介绍了术前PRAC的概念、作用机制和影响区域性动脉化疗疗效的相关因素,并就术前区域性动脉化疗在胃、结直肠癌综合治疗中的评价进行讨论.     

清开灵与利巴韦林治疗小儿呼吸道合胞病毒肺炎的比较：单盲、随机、平行对照试验

目的:比较清开灵与利巴韦林对呼吸道合胞病毒肺炎患儿治疗效果的差异。方法:选择2005-02/2006-04在北京儿童医院分中心治疗的小儿呼吸道合胞病毒肺炎97例,患儿法定监护人知情同意。采用单盲、随机、平行对照试验的原则,按区组随机化方法分为2组,清开灵注射液组49例,利巴韦林组48例。①清开灵注射液组:清开灵注射液静脉滴注加口服中成药。②利巴韦林组:利巴韦林注射液静脉滴注加口服复方愈创木酚磺酸钾口服液。两组疗程均为10d,比较两组患儿的疗效。结果:清开灵注射液组脱落3例,利巴韦林组脱落1例,进入结果分析清开灵注射液组46例,利巴韦林组47例。①清开灵注射液组发热患儿体温恢复正常时间比利巴韦林组短[(2.72±1.86)d,(6.29±2.41)d(P<0.01)]。②清开灵注射液组患儿咳嗽、痰壅、气促症状积分改善方面优于利巴韦林组(P<0.05～0.01)。③清开灵注射液组的呼吸道合胞病毒转阴时间明显优于利巴韦林组。④咳嗽、痰壅、病毒转阴时间、气促均进入Logistic模型,其中前两个症状的回归系数绝对值较大。结论:清开灵注射液治疗小儿呼吸道合胞病毒肺炎在退热、止咳平喘、呼吸道合胞病毒转阴时间等方面均具有明显优势,咳嗽、痰壅这两个症状更能反映清开灵注射液的疗效优于利巴韦林。     

Volume acceleration as an index of neuromuscular output

At the transition from expiration to inspiration, when flow and volume changes are small, changes in the respiratory system driving pressure could determine the degree of volume acceleration (AI), which, in turn, could reflect the degree of respiratory center output. To test this hypothesis, we calculated AI occurring in each respiratory cycle at the transition from expiration to inspiration during CO2 rebreathing in 4 healthy supine subjects. To minimize the flow and volume change over the measurement interval, we measured AI just prior to inspiration within the limits of an expiratory flow of 0.2 L . sec -1 to zero flow using digital differentiation. We also measured mouth pressure 100 msec after the onset of inspiration (P0.1) during intermittent transient inspiratory airway occlusions. During CO2 rebreathing AI increased significantly with both increasing PCO2 and P0.1. We also compared pairs of rebreathing studies, performed without and with an alinear (16 cm H2O . L -1 . sec -1) inspiratory resistor (IR), repeated twice in the 4 subjects. IR markedly decreased delta VE/delta PCO2 and the slope of the increase in mean inspiratory flow rate with PCO2 (delta VT/TI/delta PCO2) but did not significantly alter either delta AI/delta PCO2 or the increase in P0.1 with PCO2 (delta P0.1/delta PCO2). However, the effects of IR on AI and P0.1 differed between the early and late phases of each rebreathing run; early in the rebreathing runs (PCO2 = 55 Torr) IR increased both AI and P0.1 by a similar amount, but near the end of rebreathing (PCO2 = 60 Torr) IR increased P0.1 but not AI. Our results are consistent with the possibility that AI reflects neuromuscular output under the conditions of the study. Hence this approach justifies further evaluation to determine its general applicability.