Using a monotone single-index model to stabilize the propensity score in missing data problems and causal inference

The augmented inverse weighting method is one of the most popular methods for estimating the mean of the response in causal inference and missing data problems. An important component of this method is the propensity score. Popular parametric models for the propensity score include the logistic, probit, and complementary log-log models. A common feature of these models is that the propensity score is a monotonic function of a linear combination of the explanatory variables. To avoid the need to choose a model, we model the propensity score via a semiparametric single-index model, in which the score is an unknown monotonic nondecreasing function of the given single index. Under this new model, the augmented inverse weighting estimator (AIWE) of the mean of the response is asymptotically linear, semiparametrically efficient, and more robust than existing estimators. Moreover, we have made a surprising observation. The inverse probability weighting and AIWEs based on a correctly specified parametric model may have worse performance than their counterparts based on a nonparametric model. A heuristic explanation of this phenomenon is provided. A real-data example is used to illustrate the proposed methods.     

Colon and rectal cancer risk after bariatric surgery in a multicountry Nordic cohort study

Obesity is a risk factor for colorectal cancer. Yet, some research indicates that weight-reducing bariatric surgery also increases colorectal cancer risk. Our study was undertaken because current evidence examining bariatric surgery and risk of colorectal cancer is limited and inconsistent. This population-based cohort study included adults with a documented obesity diagnosis in Denmark, Finland, Iceland, Norway or Sweden in 1980–2015. The incidence of colorectal cancer in participants with obesity who had and had not undergone bariatric surgery was compared to the incidence in the corresponding background population by calculating standardized incidence ratios (SIR) with 95% confidence intervals (CI). Additionally, operated and nonoperated participants with obesity were compared using multivariable Cox regression, providing hazard ratios (HR) with 95% CIs adjusted for confounders. Among 502,772 cohort participants with an obesity diagnosis, 49,931(9.9%) underwent bariatric surgery. The overall SIR of colon cancer was increased after bariatric surgery (SIR 1.56; 95% CI 1.28–1.88), with higher SIRs ≥10 years postsurgery. The overall HR of colon cancer in operated compared to nonoperated participants was 1.13 (95% CI 0.92–1.39) and 1.55 (95% CI 1.04–2.31) 10–14 years after bariatric surgery. Bariatric surgery did not significantly increase the risk of rectal cancer (SIR 1.14, 95% CI 0.83–1.52; HR 1.08, 95% CI 0.79–1.49), but the risk estimates increased with longer follow-up periods. Our study suggests that bariatric surgery is associated with an increased risk of colon cancer, while the support for an increased risk of rectal cancer was weaker.     

基于网络药理学和分子对接技术的抗病毒颗粒治疗新型冠状病毒肺炎（COVID-19）的潜在物质基础研究

目的通过网络药理学及分子对接技术探寻抗病毒颗粒治疗新型冠状病毒肺炎(COVID-19)的潜在物质基础。方法借助TCMSP检索抗病毒颗粒中板蓝根、连翘、石膏、知母、芦根、地黄、广藿香、石菖蒲、郁金的化学成分和作用靶点。通过Uni Prot数据库查询靶点对应的基因,进而运用Cytoscape3.6.1构建药材-化合物-靶点(基因)网络,通过DAVID进行基因本体(GO)功能富集分析和KEGG通路富集分析,预测其作用机制,将药材-化合物-靶点网络中排名前15的成分与新型冠状病毒(SARS-Co V-2)3CL水解酶进行分子对接,同时将比枯枯灵、木犀草素、槲皮素与血管紧张素转化酶Ⅱ(ACE2)进行分子对接。结果药材-化合物-靶点(基因)网络包含药材8个、化合物75个、靶点255个。GO功能富集分析得到GO条目161个(P0.05),其中生物过程(BP)条目65个,细胞组成(CC)条目36个,分子功能(MF)条目60个。KEGG通路富集筛选得到131条信号通路(P0.05)。分子对接结果显示抗病毒颗粒中比枯枯灵、木犀草素、槲皮素等核心活性化合物与SARS-Co V-23CL水解酶的亲和力与临床推荐化学药相似。结论抗病毒颗粒中的活性化合物比枯枯灵、木犀草素、槲皮素等能通过与ACE2结合作用于PTGS2、HSP90AB1、PTGS1等靶点调节多条信号通路,从而可能发挥对COVID-19的治疗作用。     

原发性肝淀粉样变1例报告并文献回顾

目的:报道1例原发性肝淀粉样变病例，提高该病的认识水平，减少误诊误治。方法:分析我院2015年03月诊治并经病理学确诊的肝淀粉样变1例，并结合国内外文献，对本病的临床表现、诊断、治疗及预后进行讨论分析。结果:患者临床表现为右上腹隐痛、腹胀、肝大；既往:1年前因脾破裂于我院肝胆外科行脾切除术；术后病理:（脾）内有较多出血，有血肿形成，周围脾白髓萎缩，红髓间质有玻璃样变性，符合陈旧性脾破裂伴血肿形成。肝功提示:碱性磷酸酶明显升高，白蛋白减低，球蛋白升高，肝脏CT示肝脏体积明显增大，肝脏实质强化不均匀，胆囊结石。肝穿刺组织病理活检:肝细胞索变性坏死，有炎细胞浸润，肝索内肝细胞间有粉染无结构物质，免疫组化染色结果:CD34(-)、刚果红染色(+)。结论:对肝淀粉样变缺乏诊治经验是该病误诊的原因之一，以腹痛、肝大为主要临床表现极易误诊为脂肪肝，肝硬化及原发性肝癌。当临床上遇到肝脏肿大明显伴碱性磷酸酶明显升高且与其他肝功生化指标变化不平行时，尤其合并多器官受累表现者，须警惕肝淀粉样变的可能，确诊的惟一方法是肝穿刺行组织病理检查，但应注意出血等并发症。     

益气活血化瘀方治疗高血压性脑基底节出血术后的临床研究

目的观察益气活血化瘀方治疗高血压性脑基底节出血术后的临床疗效。方法将60例高血压性脑基底节出血患者随机分为观察组28例与对照组32例,对照组予单纯手术治疗,观察组在手术基础上联合益气活血化瘀方治疗。观察两组患者在治疗前后格拉斯哥昏迷指数(GCS)评分、肌力、血肿体积、中医证候积分、住院时间,并评估疗效。结果经治疗后,两组患者GCS评分明显下降,血肿体积明显缩小,中医证候积分明显降低,术后瘫痪侧肌力均明显改善(均P<0.05),观察组改善程度优于对照组(P<0.05);观察组中医证候总有效率为75.00%,明显高于对照组的59.38%(P<0.05);观察组的住院时间明显短于对照组(P<0.05)。结论益气活血化瘀方联合手术治疗可明显改善高血压性脑基底节出血患者的GCS评分、肌力,降低中医证候积分,缩小血肿体积,缩短住院时间,提高中医证候疗效。     

光学表面监测系统与CBCT确定左侧乳腺癌深吸气屏气放疗误差的比较

目的 建立本单位应用光学表面监测系统(OSMS)门控技术在左侧乳腺癌深吸气屏气(DIBH)放疗的基本流程,比较应用OSMS与CBCT确定左侧乳腺癌DIBH放疗摆位误差的一致性。方法 20例左侧乳腺癌患者采用DIBH方法治疗,OSMS与模拟定位DIBH体表外轮廓配准,CBCT扫描与模拟定位CT配准各记录得到误差数据,数据包括左右(x)、上下(y)、前后(z)方向平移误差和旋转误差Rx、Ry、Rz。采用Pearson法分析两者相关性,Bland-Altman法检验两者一致性。结果 两种方法呈正相关,x、y、z方向平移误差以及Rx、Ry、Rz方向旋转误差的相关系数分别为0.84、0.74、0.84、0.65、0.41、0.54(P<0.01),95%CI值分别为-0.37~0.42 cm、-0.39~0.41 cm、-0.29~0.49cm和-2.9°~1.4°、-2.6°~1.4°、-2.4°~2.5°,均<5mm和3°。20例左侧乳腺癌DIBH放疗患者系统误差<0.18cm,随机误差<0.24cm。结论 左侧乳腺癌DIBH放疗中应用OSMS与CBCT两种方式确定与模拟定位状态误差具有一致性,CBCT图像引导基础上使用无辐射的OSMS验证位置信息是安全可靠的。     

138例儿童颅外恶性生殖细胞肿瘤临床研究

目的:研究儿童恶性生殖细胞瘤（malignant germ cell tumor，MGCT）的临床及预后特征。方法:回顾性分析1998年1月至2016年1月上海儿童医学中心收治的初发颅外MGCT患儿138例。对患儿的临床特点、疗效及预后做综合分析。结果:按病理分期，Ⅰ期患儿5年总生存期（overall survival，OS）OS为100.00%，Ⅱ期患儿5年为94.44%，Ⅲ期5年OS为96.43%，Ⅳ期5年OS为88.73%。多因素分析显示，病理分期对生存率的影响有统计学差异（P<0.01），年龄、性别及部位对于生存率的影响无显著统计学差异。本研究中共有13例Ⅰ/Ⅱ期患儿接受手术后临床观察，有5例（38.5%）在2年内出现疾病复发进展的情况并接受化疗，目前均达到临床缓解。结论:通过以手术联合含铂类药物化疗并根据临床危险度的不同分层治疗MGCT瘤患儿，可得到较好的临床疗效。     

丹参干燥前后游离型和结合型酚酸的比较研究

丹参干燥前后,新鲜和干燥丹参中酚酸成分含量有显著性差异,即在干燥过程中随脱水增加,丹参酚酸含量显著增加。为探究丹参干燥前后游离型和结合型酚酸含量的差异及转化,该实验对丹参酚酸水解方法、水解产物、水解规律等进行研究,采用UPLC测定丹参结合型酚酸4种主要水解产物丹参素、咖啡酸二聚体(SMND-309)、咖啡酸、甘西鼠尾草酸甲(原紫草酸)以及丹参中3种主要游离酚酸成分(迷迭香酸、紫草酸和丹酚酸B)的含量。结果显示,丹参酚酸的碱水解效果显著优于酸水解,优选的碱水解条件为用含有1%抗坏血酸的2 mol·L-1氢氧化钠溶液于70℃水解4 h;游离酚酸和结合酚酸的水解产物相同;新鲜丹参中游离酚酸含量较低,结合酚酸含量较高,而干燥丹参却相反。提示丹参生长过程中已积累储存了大量的结合型酚酸,主要以酯键与细胞壁多糖结合形成了不溶性酚酸,常规方法不易检出,在干燥脱水过程中,结合型酚酸或在相关酶的作用下转化生成大量的游离酚酸。     

Antiviral Properties of Traditional Chinese Medicine against Coronavirus: Research Clues for Coronavirus Disease-2019

The objective of this study was to provide research clues for the prevention and treatment of coronavirus disease?2019 (COVID?19) and coronavirus (CoV) infection using Traditional Chinese Medicine (TCM). A review on research and clinical trials that using TCM extracts and active ingredients against CoV was performed, and a table of TCM agents and their effects on CoV were summarized. Relevant analysis was performed and visual expression of the data included summarizing the types of TCM and treatment methods for COVID?19. TCM fighting against CoV is mainly used in the lung and heart channels, and its medicinal properties are mainly cold and mild, while its taste is mainly bitter and sweet. The majority of research focused on treatments that clear away heat and toxic materials and those that strengthen body resistance and tonify deficiencies. TCM has unique advantages to fight against CoV. The development of new anti?CoV therapy using TCM is of great significance for the prevention and treatment of COVID?19 pneumonia and various viral infectious diseases.