Derivation of internal dose-based thresholds of toxicological concern for occupational inhalation exposure to systemically acting organic chemicals

This study aimed at deriving occupational thresholds of toxicological concern for inhalation exposure to systemically-acting organic chemicals using predicted internal doses. The latter were also used to evaluate the quantitative relationship between occupational exposure limit and internal dose. Three internal dose measures were identified for investigation: (i) the daily area under the venous blood concentration vs. time curve, (ii) the daily rate of the amount of parent chemical metabolized, and (iii) the maximum venous blood concentration at the end of an 8-hr work shift. A dataset of 276 organic chemicals with 8-hr threshold limit values-time-weighted average was compiled along with their molecular structure and Cramer classes (Class I: low toxicity, Class II: intermediate toxicity, Class III: suggestive of significant toxicity). Using a human physiologically-based pharmacokinetic model, the three identified dose metrics were predicted for an 8-hr occupational inhalation exposure to the threshold limit value for each chemical. Distributional analyses of the predicted dose metrics were performed to identify the percentile values corresponding to the occupational thresholds of toxicological concern. Also, simple linear regression analyses were performed to evaluate the relationship between the 8-hr threshold limit value and each of the predicted dose metrics, respectively. No threshold of toxicological concern could be derived for class II due to few chemicals. Based on the daily rate of the amount of parent chemical metabolized, the proposed internal dose-based occupational thresholds of toxicological concern were 5.61?×?10^?2 and 9?×?10^?4 mmol/d at the 10th percentile level for classes I and III, respectively, while they were 4.55?×?10^?1 and 8.5?×?10^?3 mmol/d at the 25th percentile level. Even though high and significant correlations were observed between the 8-hr threshold limit values and the predicted dose metrics, the one with the rate of the amount of chemical metabolized was remarkable regardless of the Cramer class (r² = 0.81; n = 276). The proposed internal dose-based occupational thresholds of toxicological concern are potentially useful for screening-level assessments as well as prioritization within an integrated occupational risk assessment framework.     

电针复合TCI靶控输注在单肺通气食管癌开胸手术麻醉中的应用与安全性＊

目的 探讨电针复合靶控输注（Target Controlled Infusion， TCI）在单肺通气食管癌开胸手术麻醉中的应用价值。方法 选取于我院拟行单肺通气食管癌开胸切除手术患者60例作为研究对象。随机将其分为试验组与对照组，对照组30例采取气管插管全麻及TCI靶控输注维持麻醉深度，试验组30例则在对照组方案基础上辅助电针麻醉，记录两组患者手术麻醉时间、药物用量、苏醒时间、并发症；以及术前（T_Ⅰ）、插管前即刻（T_Ⅱ）、插管后1 min（T_Ⅲ）、切皮即刻（T_Ⅳ）、去骨时（T_Ⅴ）、拔管即刻（T_Ⅵ）时平均动脉压（MAP）、平均心率（HR）、BIS值；术前、术后1天、术后3天简易智能精神状态检查量表（MMSE）；并于麻醉诱导前（T₀）、手术开始2 h（T₁）、术后1天（T₂）、术后3天（T₃）时抽取患者外周静脉血检测IL-1β、IL-6、IL-10、TNF-α浓度。结果 试验组手术用时、麻醉时间略低于对照组，但差异无统计学意义（P>0.05），试验组异丙酚、舒芬太尼用量以及苏醒时间均明显低于对照组（P<0.05）；T_Ⅱ时两组平均动脉压（Mean Arterial Pressure， MAP）、心率（Heartrate， HR）较术前明显降低，且试验组MAP明显低于对照组（P<0.05），但两组T_Ⅱ时HR比较无显著差异（P>0.05）；T_Ⅲ、T_Ⅵ时对照组MAP、HR明显高于T_Ⅰ时，而试验组MAP、HR与T_Ⅰ比较无显著差异（P>0.05）。术后1天、3天试验组简易智能精神状态检查量表（Mini-Mental State Examination， MMSE）评分低于对照组，有显著性差异（P<0.05）。T₁、T₂、T₃时试验组白介素-1β（IL-1β）、白介素-6（IL-6）、肿瘤坏死因子（Tumor Necrosis Factor-α， TNF-α）水平明显低于对照组（P<0.05），白介素-10（IL-10）水平明显高于对照组（P<0.05）。结论 采用电针复合TCI靶控输注麻醉方案可有效提升单肺通气食管癌开胸手术麻醉效果，能够降低患者术后认知功能障碍发生风险。     

基于家庭的心理治疗对强迫障碍治疗的研究进展

强迫障碍(obsessive-compulsive disorder,OCD)是常见的难治性精神疾病,经过心理治疗和药物治疗仅有40%~60%患者获得缓解,患者残留各种症状和功能障碍。心理治疗是OCD治疗的重要组成部分,家庭因素在疾病的发生、维持和预后中起重要作用,以家庭为基础的心理治疗越来越受到重视。文章就对OCD采用基于家庭的心理治疗的必要性和进展进行综述,研究显示患者家属的精神心理状态和家庭顺应性等因素与OCD治疗效果密切相关,而家庭成员高度参与,针对家庭因素干预的基于家庭的心理治疗策略可以增强治疗效果,改善患者家庭功能。文章为强迫障碍的临床优化治疗提供了实践依据。     

细胞因子白细胞介素-4对认知功能改善的研究进展

白细胞介素4(IL-4)是T辅助2(Th2)介导的免疫反应的基本免疫调节细胞因子,IL-4具有复杂的信号系统和多效的功能,但在脑组织中,诸多研究发现IL-4可在炎症中保护认知功能。该文总结了关于IL-4保护认知功能的证据及机制,以及在阿尔茨海默病、缺血性脑血管病以及手术后认知功能障碍中IL-4保护认知功能的途径及证据。     

Children's diets,pesticide uptake,and implications for risk assessment: An Israeli case study

The presence of pesticides in the Israeli food supply is well documented but little is known about the risks posed by children's diets for potential exposures. We investigated potential exposures to food-borne pesticides in a sample of 301 urban Israeli children (2008–10). Data from a food frequency questionnaire, 24 hour food recall, and Israel's national pesticide monitoring program were used to estimate uptake factors for 26 compounds in 27 fruits and vegetables. A pilot risk assessment was performed and the findings were compared with the Israel Ministry of Health's 2012 pesticide risk assessment for the general population. The surveyed children had higher potential exposures than the general population for over one third of the compounds, and uptake factors exceeded the Acceptable Daily Intake in ten compounds. Methamidophos, exceeded the ADI at the 25th percentile and fenamiphos, iprodione, and oxydemethon methyl, exceeded the ADI at the 50 percentile. ADIs for several compounds were exceeded even though the residues detected were below the statutory limit. Improved monitoring, enforcement, and revision of the Maximum Residue Limit for certain food/pesticide pairs are indicated as is the need to incorporate data on children's actual food consumption in national risk assessments.