China special issue on gastrointestinal tumors-Radiological features of pathological complete response in mismatch repair deficient colorectal cancer after neoadjuvant PD-1 blockade: A post hoc analysis of the PICC phase II trial

Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy.     

寰枢椎后路柔性固定的生物力学研究

目的分析细棒、PEEK棒固定对寰枢关节稳定性的影响。方法采用6具新鲜成人枕骨(occipital bone,Oc)~颈椎C4节段进行测试,模拟以下手术及固定状态:①完整状态;②损伤状态:枢椎齿状突II型骨折;③坚强固定:寰枢椎均采用普通椎弓根螺钉固定,直径3.5 mm钛棒连接;④PEEK棒:直径3.5 mm的PEEK棒连接;⑤细棒:直径2.0 mm钛棒连接。采用重复测量实验设计,在完整、损伤和不同的固定状态下,通过脊柱试验机对标本分别施加1.5 N·m的前屈/后伸、左/右侧弯和左/右轴向旋转的纯力偶矩。采用Optotrak三维运动测量系统连续采集标本运动,分析寰枢椎之间角度运动范围和中性区。结果采用直径3.5 mm的钛棒,2.0 mm的细棒以及3.5 mm的PEEK棒固定后,在前屈、后伸、侧弯和旋转方向上均显著减小了固定节段的运动范围(P<0.05)。直径3.5 mm和2.0 mm的棒固定后的运动范围,在各个方向上无显著性差异。PEEK棒固定的运动范围仅在侧弯方向上大于坚强固定(P=0.005),其他方向无显著性差异。3种固定方式在屈伸、侧弯和旋转方向上均显著减小了固定节段的中性区(P<0.05)。各种固定方式之间相比较,无显著性差异(P>0.05)。结论在寰枢关节采用直径2.0 mm的细棒固定,与坚强固定的稳定性相当。采用直径3.5 mm的PEEK棒固定,在前屈、后伸、旋转方向上与坚强固定的稳定性相当,在侧弯方向上弱于坚强固定。     

A High Order Bound Preserving Finite Difference Linear Scheme for Incompressible Flows

We propose a high order finite difference linear scheme combined with a high order bound preserving maximum-principle-preserving (MPP) flux limiter to solve the incompressible flow system. For such problem with highly oscillatory structure but not strong shocks, our approach seems to be less dissipative and much less costly than a WENO type scheme, and has high resolution due to a Hermite reconstruction. Spurious numerical oscillations can be controlled by the weak MPP flux limiter. Numerical tests are performed for the Vlasov-Poisson system, the 2D guiding-center model and the incompressible Euler system. The comparison between the linear and WENO type schemes, with and without the MPP flux limiter, will demonstrate the good performance of our proposed approach.     

论当前疾病预防控制体系面临的主要问题

对当前的疾病预防控制体系和机构面临的体系不健全、政府投入不充分、事业发展不平衡、人才缺失和能力不足、缺乏系统的理论指导、体系的碎片化严重、与社会经济发展的战略衔接不力、机构内部内生动力和活力不足以及体系治理能力不足等问题做了讨论分析,以期进一步分析在健康中国战略和事业单位机构改革等宏观环境变化所带来的机遇以及疾控体系的发展策略和具体措施,促进疾病预防控制事业在改革中谋发展。     

骨形态发生蛋白2及碱性成纤维生长因子2对大鼠骨髓间充质干细胞膜片增殖和成骨分化的影响

文题释义： 细胞膜片技术：是在体外接种培养高密度的细胞，使其相互融合生长至100%而形成的透明致密膜状物。该技术不需要胰酶消化即可收集细胞，因此保留了大量的胞外基质、细胞间连接以及细胞-基质连接等结构。目前细胞膜片技术已成为组织工程领域的研究热点，已被推广应用于牙周膜、角膜、心脏、软骨、食管等多种组织器官修复。 成骨细胞：主要由内外骨膜和间充质始祖细胞分化而来，在复杂的骨形成过程中发挥着主要的功能，承担着骨基质的合成、分泌和矿化。骨髓间充质干细胞具有多向分化潜能，能定向分化为成骨细胞，其成骨分化过程可受多种因素的影响，如细胞因子的调控、遗传因素和激素水平等。背景：现阶段骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖、成骨分化的影响和作用机制还尚未可知，如何将生长因子与组织工程细胞膜片技术相整合，最终将其用于骨缺损修复具有重要意义。 目的：探讨单独及联合应用骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖和成骨分化的影响。 方法：体外分离培养鉴定SD大鼠骨髓间充质干细胞并构建细胞膜片，选用不同质量浓度的骨形态发生蛋白2和碱性成纤维生长因子2单独及联合诱导骨髓间充质干细胞膜片，CCK-8法结合碱性磷酸酶活性检测确定2种因子促进膜片增殖和成骨分化的最佳有效质量浓度；然后对骨髓间充质干细胞膜片进行成骨诱导，通过大体及显微镜观察、Vonkossa染色、茜素红染色、RT-PCR检测相关成骨标志物来评估诱导效果。 结果与结论：单独应用骨形态发生蛋白2可增强骨髓间充质干细胞膜片的碱性磷酸酶活性，最佳质量浓度为100 μg/L(P < 0.001)，单独应用碱性成纤维生长因子2能加速骨髓间充质干细胞膜片的增殖，最佳质量浓度为20 μg/L(P < 0.001)，而联合应用既可以促进膜片增殖又能提高其碱性磷酸酶活性(P < 0.001)；经成骨诱导后，4组膜片在形态学上无明显差异，均能诱导骨髓间充质干细胞膜片的成骨分化，其中联合组钙结节最明显(P < 0.001)，可显著促进膜片晚期成骨分化并抑制其早期成骨分化，具有明显的协同促进作用(P < 0.001)。结果表明，骨形态发生蛋白2和碱性成纤维生长因子2联合应用时具有协同作用，既可以促进骨髓间充质干细胞膜片增殖，又能显著增强其成骨诱导能力。ORCID: 0000-0003-1918-579X(何惠宇) 中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程     

基于雨课堂的临床流行病学教学改革与实践

目的探讨雨课堂在临床流行病学教学中的作用和效果。方法采用随机对照法在本科阶段无流行病学学习经历的临床专业硕士研究生中,使用雨课堂线上课前预习及课后随堂练习的功能,用于评价雨课堂线上功能的辅助教学效果。结果应用雨课堂线上功能干预组与对照组在基线、阶段小测和末考卷面成绩均无统计学差异;但对于主动学习,雨课堂参与度较高的学生成绩提高明显。结论雨课堂有利于理论性较强课程的学习,但是仍不能忽略课堂教学师生互动过程。     

Outcomes after neoadjuvant or adjuvant chemotherapy for cT2-4N0-1 non–small cell lung cancer: A propensity-matched analysis

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Association Study of Matrix Metalloproteinases Gene Polymorphisms with Susceptibility to Rheumatoid Arthritis: A Meta-Analysis

Objective: Association of matrix metalloproteinases (MMPs) gene polymorphisms with rheumatoid arthritis is controversial. We conduct a meta-analysis to clarify this dispute.

Methods: We systematically searched the electronic PUBMED, EMBASE and CNKI databases for research articles about MMPs (MMP-1, MMP-2, MMP-3, MMP-9) gene polymorphisms and rheumatoid arthritis (RA) up to January 2015. According to the heterogeneity, fixed-effects or random-effects models were used to calculate crude odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results: A total of 11 articles involving 2143 cases and 2049 controls were included in this meta-analysis. Overall, no significant associations were observed between MMP-1-1607 1G/2G polymorphism and RA. Stratification by ethnicity, no significant associations were observed in Caucasian populations. Similarly, no significant associations were observed between MMP-3-1171 5A/6A, MMP-9-1562 C/T polymorphisms and RA in overall and Caucasian populations, respectively. However, a weak association was found between MMP-2-1306 C/T polymorphism and RA (C vs. T, OR?=?0.813, 95%CI?=?0.694–0.953, p?=?0.010) in overall populations.

Conclusions: The present meta-analysis suggests that MMP-1-1607 1G/2G, MMP-3-1171 5A/6A, MMP-9-1562 C/T polymorphisms are not associated with the susceptibility of RA, but MMP-2 -1306 C/T is weakly associated with susceptibility to RA. Further studies with more sample size are needed for definitive conclusions.     

解剖锁定钢板联合同种异体腓骨治疗肱骨近端骨折疗效的Meta分析

文题释义：肱骨近端骨折：肱骨近端包括肱骨头及大结节、小结节，中老年人骨质疏松及低能量损伤可导致肱骨近端骨折。 同种异体腓骨：取自于人体异体，经过加工处理，去除其免疫原性，保留其骨性结构，可用于移植修复骨缺损，起到支撑作用。 背景：肱骨近端骨折是临床常见骨折，但对肱骨近端内侧柱缺乏支撑的骨折目前仍是治疗难点，并发症常见，失败率较高。 目的：比较解剖锁定钢板联合同种异体腓骨与单纯解剖锁定钢板治疗肱骨近端骨折的疗效。 方法：使用计算机检索PubMed、Embase、Cochrane Library、Google Scholar、中国知网、万方、维普数据库，检索时间均从建库到2020年2月。检索国内外关于对比研究解剖锁定钢板联合同种异体腓骨与单纯解剖锁定钢板治疗肱骨近端骨折疗效的文献。2名研究员根据纳入和排除标准分别独立筛选文献，提取数据，评估文献中的偏倚风险。纳入12篇相关文献使用RevMan 5.2软件将以下指标进行Meta分析，包括影像学数据、功能评分和并发症。结果与结论：①通过文献检索、根据纳入和排除标准，12篇文献纳入研究，其中11篇为回顾性队列研究，1篇为随机对照研究；纳入研究文献质量高，但GRADE证据质量级别较低。②共纳入958例患者，其中解剖锁定钢板联合同种异体腓骨组411例，单纯解剖锁定钢板组547例；③Meta分析结果显示，解剖锁定钢板联合同种异体腓骨组术后1年肱骨头高度差值(MD=-2.40，95%CI：-2.49至-2.31)、颈干角差值(MD= -6.14，95%CI：-6.62至-5.67)、目测类比评分(MD=-0.22，95%CI：-0.35至-0.08)、肩关节功能评分(MD=4.12，95%CI：2.18-6.06)，上肢伤残评分(MD=-10.32，95%CI：-13.44至-7.19)、术后2年的目测类比评分(MD=-0.37，95%CI：-0.55至-0.19)、肩关节功能评分(MD=5.07，95%CI：2.86-7.27)、总体并发症(OR=0.31，95%CI：0.20-0.48)及肱骨头螺钉切出(OR=0.25，95%CI：0.11-0.55)均明显优于单纯解剖锁定钢板组(P < 0.05)，肱骨头坏死(OR=0.94，95%CI：0.47-1.88)，两组间差异无显著性意义(P > 0.05)；④因此，较弱的证据提示，肱骨近端解剖锁定钢板联合同种异体腓骨治疗肱骨近端骨折的短期疗效优于解剖锁定钢板，可减少并发症的发生，促进功能恢复。ORCID: 0000-0002-8486-3932(阳运康) 中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程