高仿真情景模拟下生命支持设备培训的应用

目的通过高仿真情景模拟下生命支持设备的培训,临床工程师可以了解设备的操作和常见故障的现场解决方法,还可以通过学习相关的医学知识,对临床科室的工作有进一步的认识,以提高快速判断和处理生命支持设备现场常见故障的能力。方法学员根据临床救治要求给高仿真模拟人(human patient simulator,HPS)使用相应的生命支持设备,后台操作老师根据培训现场情况随时改变HPS的病例程序,现场授课老师根据HPS的病情变化引起生命支持设备相应的反应,设置和口述生命支持设备的各种故障现象,要求学员迅速做出判断处理。授课老师依据考核表的各个项目进行考核,采用标准的"简短理论讲授+分项技术练习+综合模拟演练+录像分析总结"教学模式。结果通过授课老师录像回顾点评分析,在进行第二轮演练时,学员各项考核得分都有了较大提高,与第一轮演练成绩的差异具有统计学意义(P0.05)。结论临床工程师定期参加生命支持设备相关培训是非常必要的,通过高仿真情景模拟下生命支持设备培训,使受训的临床工程师在"身临其境"的临床救治过程中,对心肺复苏、呼吸衰竭救治的操作技能,以及对生命支持设备的操作、现场常见故障的判断和解决的能力有了较大提高,真正做到医工结合。     

离体脊柱生物力学测试的加载方法研究进展

离体脊柱标本三维运动载荷-位移特性的描述是脊柱生物力学研究的基础,如何准确地模拟在体脊柱的载荷与运动情况是脊柱生物力学研究的难点。国内外学者从测试理论与测试工具上都进行了大量的研究。目前脊柱三维运动测试按照控制方法主要分为载荷控制、位移控制和混合控制。基于不同的控制方法,测试工具也在不断的发展与完善之中。总结目前国内外研制的脊柱离体加载装置的工作原理,并分析其主要优缺点,为离体脊柱生物力学加载装置研究提供参考。     

采用分子动力学模拟方法探究Ca~(2+)对VWF-A2结构域稳定性的影响

目的探究Ca~(2+)对VWF-A2结构域稳定性的影响。方法 A2和A2/Ca~(2+)的晶体结构取自PDB数据库。通过恒力拉伸分子动力学模拟,比较分析Ca~(2+)结合引起的构象变化、解折叠路径的差异以及酶切位点的暴露程度。结果 A2结构域的解折叠路径和酶切位点的暴露过程是力依赖的。Ca~(2+)结合不影响A2结构域的前期解折叠,但由于α3β4-环链局部构象重排所致柔性降低,约束了β1-β4-β5片层的运动,导致进一步解折叠受阻而停留在中间稳态,影响酶切位点的充分暴露。结论力可诱导A2结构域中β5片层的解折叠使酶切位点暴露,而Ca~(2+)的结合则通过稳定疏水核心结构,阻碍酶切位点的暴露,最终降低ADAMTS13的酶切效率。研究结果有助于加深对ADAMTS13酶切VWF-A2结构域进而调控VWF止血能力过程的理解,并为相关抗血栓药物设计提供指导。     

Prognostic and clinicopathological significance of PD-L1 in patients with renal cell carcinoma: a meta-analysis based on 1863 individuals

The prognostic significance of PD-L1 in renal cell carcinoma (RCC) had been investigated in previous studies; however, the results remain controversial. The primary aim of this meta-analysis was to investigate the prognostic and clinicopathological significance of the PD-L1 expression in patients with RCC. Relevant literature was identified form PubMed, Embase, Web of Science and Cochrane library, which compared the prognostic significance between PD-L1 expression and RCC. Hazard ratios (HRs) for survival outcomes and odds ratios (ORs) for clinical parameters associated with PD-L1 were extracted from eligible studies. Heterogeneity was assessed using the I² value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg’s funnel plots and Egger’s regression test. A total of 1863 patients from ten eligible studies were analyzed. The results showed that PD-L1 expression is associated with poor overall survival in clear cell RCC (ccRCC) (HR = 2.76, 95%CI: 2.25–3.38, I² = 14.4%, P < 0.001) and non-clear cell RCC (non-ccRCC) (HR = 2.77, 95%CI: 1.62–4.72, I² = 28.8%, P < 0.001). In addition, PD-L1 expression was found to be significantly associated with primary tumor stage (OR = 1.76, 95%CI: 1.39–2.23; I² = 56.3%), regional lymph node involvement (OR = 2.10, 95%CI: 1.48–2.98; I² = 14.9%), distant metastases (OR = 2.69, 95%CI: 2.05–3.54; I² = 0.0%), nuclear grade (OR = 1.72, 95%CI: 1.32–2.23; I² = 79.4%) and histologic tumor necrosis (OR = 2.25, 95%CI: 1.59–3.18; I² = 66.1%) in patients with RCC. The outcome stability was confirmed by sensitivity analysis. Both the Begg’s funnel plot test (P = 0.276) and the Egger’s (P = 0.388) verified that there was no publication bias within the included studies. This study suggests that PD-L1 expression is correlated with poor prognosis and advanced clinicopathological features in RCC patients.     

Massively parallel sequencing on human cleavage-stage embryos to detect chromosomal abnormality

Purpose

Next-generation sequencing technology like MPS has recently been introduced to perform comprehensive chromosome screening on human trophectoderm samples for preimplantation embryo assessment. However, the potential of MPS in chromosome analysis of single cell from blastomeres has not yet been investigated.

Immunogenicity of insulin producing cells differentiating from human umbilical cord mesenchymal stem cells北大核心

BACKGROUND: Human umbilical cord mesenchymal stem cells (hUC-MSCs) have low immunogenicity and it is unclear whether insulin producing cells (IPCs) that differentiate from hUC-MSCs have low immunogenicity. OBJECTIVE: To investigate the immunogenicity of IPCs differentiating from hUC-MSCs in vitro and after IPCs transplantation into the host. METHODS: (1) The hUC-MSCs were induced to differentiate into IPCs according to the modified scheme. Flow cytometry assay was used to detect the immunophenotype and apoptotic rate of IPCs in a cytotoxicity test. (2) Cell counting kit-8 was used to detect the proliferative capacity of human peripheral blood mononuclear cells in the one-way mixed lymphocyte assay. (3) The IPCs were then transplanted into the abdominal cavity and left renal capsule of mice, and then the infiltration of immune cells was detected by flow cytometry and immunohistochemistry. RESULTS AND CONCLUSION: The IPCs highly expressed HLA-ABC and lowly expressed HLA-DR, CD40 and CD80. The apoptosis rate of IPCs increased with the increase of pre-sensitized splenocytes in the cytotoxicity test. In the one-way mixxd lymphocyte assay, IPCs inhibited the proliferation of human peripheral blood mononuclear cells when the target ratio was 10:1 and 50:1. After IPCs transplantation, the number of lymphocytts was increased in the transplanttd si. In summary, our results show that IPCs that differentiatt from hUC-MSCs maintain low immunogenicity in vitro, but have some immunogenicity after transplantation into the host due to microenvironment changes. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

创伤后肘关节僵硬553例回顾性分析

目的 研究创伤后肘关节僵硬的发病情况.方法 收集1997年1月至2013年12月北京积水潭医院收治的553例创伤后肘关节僵硬患者的病历资料进行回顾性研究.记录患者的临床资料和影像学资料.结果 553例中男性366例,女性187例;平均年龄为35岁(12 ～ 76岁),以＞30 ～40岁年龄组的患者最多(166例,占30.8％).中低能量损伤301例(54.4％),高能量损伤227例(41.1％);关节外骨折、损伤60例(10.8％),平均固定时间6.1周,关节内骨折、脱位493例(89.2％),平均固定时间4.9周;肘关节活动范围平均30°(0°～110°);肘部有异位骨化者457例(82.6％),无异位骨化96例(17.4％).结论 创伤后肘关节僵硬通常累及年轻、活跃人群,在临床工作中应重视低能量损伤、关节外骨折和简单关节内骨折的治疗,避免超过3周的制动,采取适当的手术固定方式,早期进行以主动功能锻炼为主,辅以轻柔的被动练习,另外需积极应对异位骨化的发生.     

新鲜下肢骨折术前深静脉血栓形成危险程度评分量表初探

目的 初步尝试建立新鲜下肢骨折术前深静脉血栓形成危险程度评分量表,用于院内下肢骨折患者术前深静脉血栓形成危险程度的客观判断.方法 回顾性分析2011年1月至2012年12月北京积水潭医院创伤骨科治疗的新鲜下肢骨折患者资料,依据排除标准剔除病例后共纳入分析1 705例.这些患者被随机分为两组,研究组(879组)通过logistic回归分析筛选出危险因素,以多因素logistic回归OR值赋分的方法产生新鲜下肢骨折术前深静脉血栓形成危险程度评分量表,检验组(826例)对评分表进行验证.结果 纳入患者中男性1 106例,女性599例;平均年龄(50±18)岁,logistic回归分析显示可以预测深静脉血栓形成的因素包括年龄、待术时间、受伤原因、受伤部位、心脑血管疾病史以及D-二聚体(D-Dimer)检测值.根据回归OR值得出的分值分别是:年龄≤35岁为1分,＞35 ～ ＜65岁为4分,≥65岁为6分;待术时间＜8d为1分,≥8d为2分;受伤原因低能量为1分,高能量为3分;受伤部位中,足踝损伤为1分,小腿骨折为3分,膝关节周围骨折为5分,股骨中上段为7分,骨盆髋臼为4分,多发骨折为6分;无心脑血管疾病史为1分,有心脑血管疾病史为2分;D-Dimer＜ 600 μg/L为1分,≥600μg/L为3分.受试者工作特征曲线下面积为0.79,临界点15.5分,总体数据临界点灵敏度为77.00％,特异度为68.17％.结论 新鲜下肢骨折术前血栓危险程度评分量表对深静脉血栓形成具有一定的预测效能,但是存在局限性.