Generalized causal mediation analysis

The goal of mediation analysis is to assess direct and indirect effects of a treatment or exposure on an outcome. More generally, we may be interested in the context of a causal model as characterized by a directed acyclic graph (DAG), where mediation via a specific path from exposure to outcome may involve an arbitrary number of links (or "stages"). Methods for estimating mediation (or pathway) effects are available for a continuous outcome and a continuous mediator related via a linear model, while for a categorical outcome or categorical mediator, methods are usually limited to two-stage mediation. We present a method applicable to multiple stages of mediation and mixed variable types using generalized linear models. We define pathway effects using a potential outcomes framework and present a general formula that provides the effect of exposure through any specified pathway. Some pathway effects are nonidentifiable and their estimation requires an assumption regarding the correlation between counterfactuals. We provide a sensitivity analysis to assess the impact of this assumption. Confidence intervals for pathway effect estimates are obtained via a bootstrap method. The method is applied to a cohort study of dental caries in very low birth weight adolescents. A simulation study demonstrates low bias of pathway effect estimators and close-to-nominal coverage rates of confidence intervals. We also find low sensitivity to the counterfactual correlation in most scenarios.     

巧用案例与问题法提高发酵工程工艺原理教学效果

结合在发酵工程工艺原理教学中的实践,阐述了巧用具体案例及围绕问题组织教学的意义、具体实施过程以及所达到的教学效果。结果表明,巧用列举案例法、讲评案例法、讨论案例法及问题教学法可强化课堂教学知识的运用和掌握,有利于理论联系实际,便于提高学生自主学习意识,有利于提高学习兴趣以及提高教学效果。     

Application of in silico and in vitro methods in the development of adverse outcome pathway constructs in wildlife

There is a long history of using both in silico and in vitro methods to predict adverse effects in humans and environmental species where toxicity data are lacking. Currently, there is a great deal of interest in applying these methods to the development of so-called ‘adverse outcome pathway’ (AOP) constructs. The AOP approach provides a framework for organizing information at the chemical and biological level, allowing evidence from both in silico and in vitro studies to be rationally combined to fill gaps in knowledge concerning toxicological events. Fundamental to this new paradigm is a greater understanding of the mechanisms of toxicity and, in particular, where these mechanisms may be conserved across taxa, such as between model animals and related wild species. This presents an opportunity to make predictions across diverse species, where empirical data are unlikely to become available as is the case for most species of wildlife.     

丙基硫氧嘧啶影响妊娠合并甲状腺功能亢进孕妇甲状腺功能及妊娠结局的研究

目的:探讨丙基硫氧嘧啶(PTU)影响妊娠合并甲状腺功能亢进(甲亢)孕妇甲状腺功能及妊娠结局的影响。方法:选择我院妇产科2010年3月至2013年1月收治的110例妊娠合并甲亢的患者作为观察对象,随机分为观察组58例,对照组52例。观察组予PTU每天300 mg口服,对照组确诊后未能定期检测甲状腺功能而自行停药,或拒绝PTU药物治疗。结果:观察组TT3、TT4、FT3、FT4、TSH水平均显著低于对照组,差异均具有统计学意义(均P0.05);观察组早产或流产、剖宫产、妊娠高血压、心力衰竭、重度子痫明显低于对照组,而足月产明显高于对照组,差异均具有统计学意义(均P0.05);观察组的围生儿发生胎儿窘迫、低体重儿、新生儿甲亢、转入NICU发生率均显著低于对照组,两组比较差异均具有统计学意义(均P0.05)。结论:规范的PTU治疗能很好地改善妊娠合并甲亢患者的孕期甲状腺功能,减低甲亢对孕妇及新生儿的危害,改善妊娠结局,且对新生儿畸形率无显著的影响,是一种相对安全和有效的治疗方法。     

自体软骨细胞移植技术治疗膝关节软骨缺损的研究进展

膝关节软骨缺损发病率高,且自身修复能力有限。治疗膝关节软骨缺损的传统方法包括钻孔术、微骨折术、自体骨软骨移植术。然而,钻孔术和微骨折术治疗后缺损区生成的是纤维软骨,而不是正常的透明软骨,两者在力学强度、硬度、耐磨损性等多方面存在很大差距。自体骨软骨移植术可生成正常的透明软骨,但存在供体有限、不适合进行大面积软骨缺损治疗等多方面缺点在临床方面应用受限。近年来,自体软骨细胞移植技术发展迅速,越来越多的病人接受此治疗方法并获得良好效果,引起人们广泛关注。本文根据近年来国内外的各项相关研究成果进行总结,阐述膝关节软骨缺损的各种治疗方法,着重介绍自体软骨细胞移植技术。第三代自体软骨细胞移植技术生成的软骨以透明软骨为主,符合关节生物力学要求,且避免了第一代、第二代自体软骨细胞移植的术后并发症,成为治疗膝关节大面积软骨缺损安全有效的治疗方法。另外,本文就软骨细胞支架材料的发展、移植物术后的转归等问题提出进一步设想。     

枯草杆菌二联活菌对儿童巨细胞病毒性肝炎患儿肠道菌群及预后的影响

目的 探究枯草杆菌二联活菌对儿童巨细胞病毒(CMV)性肝炎患儿肠道菌群的调节作用及其对预后的影响.方法 选择2016年5月到2019年5月我院收治的81例重症巨细胞病毒性肝炎患儿为研究对象,按照随机数字表法分为联合组(n=41)和对照组(n=40).对照组患儿采用常规治疗方法,联合组患儿在对照组基础上联合枯草杆菌二联活...     

Toward Optimal Outcome Following Pivotal Response Treatment: A Case Series

There is a growing literature on children with autism spectrum disorder (ASD) who respond favorably to behavioral treatment, which is often termed “optimal outcome.” Rates and definitions of optimal outcome vary widely. The current case series describes an empirically validated behavioral treatment approach called Pivotal Response Treatment (PRT). We present two preschool-aged children who received an intensive course of PRT and seem to be on a trajectory toward potential optimal outcome. Understanding response to treatment and predictors of response is crucial, not necessarily to predict who may succeed, but to individualize medicine and match children with customized treatment programs that will be best tailored to their unique and varied needs.     

Comparison of Treatment Outcome Measures for Irritable Bowel Syndrome

We have examined the relations among three common treatment outcome measures in irritable bowel syndrome (IBS): end of treatment global ratings by a physician, end of treatment patient global ratings, and measures derived from a daily symptom diary completed by the patient. Eighty-four IBS patients (53 female, 31 male) participated in a randomized controlled evaluation of three psychological treatment conditions for IBS. Treatment outcome measures from this trial (Blanchard et al., 1992) were used in the present methodological study. Physician global ratings were significantly correlated with patient global ratings (r = .45, p < .01). Both of these global ratings also correlated significantly with a composite score from patient diary ratings. Multiple regression analyses revealed that reductions in bloating and constipation account for 18% of the variance in patient global ratings. Global ratings at end of treatment by either patient or physician were only partially related to symptom relief as measured by a daily diary.     

孕期个性化营养干预对妊娠期糖尿病孕妇糖脂水平及妊娠结局的影响

目的:探讨孕期个性化营养干预对妊娠期糖尿病孕妇糖脂水平及妊娠结局的影响。方法:选择2016年8月-2017年10月期间于我院产检的妊娠期糖尿病孕妇160例,以随机数字表法分为研究组(n=80)和对照组(n=80)。对照组给予常规营养干预,研究组则予以孕期个性化营养干预。比较两组干预前后空腹血糖、餐后2h血糖、总胆固醇(TC)、三酰甘油(TG)、高密低脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平,观察孕妇及新生儿并发症发生情况。结果:干预后两组孕妇空腹血糖、餐后2 h血糖显著降低,且研究组低于对照组(P0.05)。干预后对照组孕妇TC、TG、LDL-C较干预前显著升高(P0.05),HDL-C差异无统计学意义(P0.05),研究组血脂水平与干预前比较差异无统计学意义(P0.05),与对照组比较,研究组孕妇TC、TG、LDL-C水平更低(P0.05)。研究组妊娠期高血压、胎膜早破发生率均明显低于对照组(P0.05),两组感染、产后出血发生率比较无统计学差异(P0.05)。与对照组比较,研究组新生儿窘迫、巨大儿、新生儿低血糖、早产儿的发生率降低(P0.05)。结论:孕期个性化营养干预可有效改善妊娠期糖尿病孕妇的糖脂水平,且能够有效降低并发症发生率,从而改善妊娠结局。