农村订单定向医学生培养第二课堂的形式与教学

根据农村订单定向医学生免费本科医学教育人才培养模式改革试点的要求，落实卓越医生教育培养计划目标，以第二课堂为载体，以建立居民健康档案与开展居民健康管理为教学形式和教学内容，通过建立档案、病种筛选、自主学习、教师指导、健康管理、家庭访视、信息维护等方式，为农村订单定向医学生打下基层医疗卫生服务的坚实基础，并促进综合实践能力全面提升。     

LncRNA UCA1对肺癌细胞放射敏感性影响及机制研究

目的 研究长链非编码RNA (LncRNA) UCA1对肺癌细胞增殖、凋亡及放射敏感性影响及其机制。方法 运用qRT-PCR法检测肺癌细胞A549、H1299和人正常肺细胞HBE中UCA1、miR-513a-5p表达。将si-con组(转染si-con)、si-UCA1组(转染si-UCA1)、miR-513a-5p组(转染miR-513a-5p mimics)、miR-NC组(转染miR-NC)、IR+si-con组(转染si-con+照射)、IR+si-UCA1组(转染miR-NC+照射)、IR+miR-513a-5p组(转染miR-513a-5p mimics+照射)、IR+miR-NC组(转染miR-NC+照射)、IR+si-UCA1+anti-miR-513a-5p组(共转染si-UCA1和anti-miR-513a-5p+照射)均用脂质体法转染至A549、H1299细胞,然后部分组进行4Gy照射。MTT法检测各组细胞增殖,克隆形成实验检测细胞增敏比,流式细胞术检测各组细胞凋亡,双荧光素没报告基因检测实验检测各组细胞的荧光活性。结果 与HBE细胞相比,A549、H1299细胞中UCA1表达显著升高(P<0.05),miR-513a-5p表达显著降低(P<0.05)。抑制UCA1、过表达miR-513a-5p均可明显抑制A549、H1299细胞增殖、促进凋亡、提高放射敏感性(放射增敏比为1.897、2.146和1.615、1.872)。miR-513a-5p可抑制野生型UCA1细胞的荧光活性,且UCA1可负向调控miR-513a-5p的表达。抑制miR-513a-5p可逆转抑制UCA1对细胞的放射敏感性的增强作用。结论 抑制LncRNA UCA1可增强放射对肺癌细胞敏感性,其机制可能与靶向抑制miR-513a-5p有关。     

静息态功能磁共振成像功能连接特异性指数模型在评估健康老年人认知分数中的应用

与传统量表法和任务态功能磁共振成像(fMRI)相比,静息态功能磁共振(rfMRI)在认知功能检测上有很大优势(特别是针对老年人),但脑老化功能影像学标记尚在探索中。提出功能连接特异性指数模型,试图与健康壮年人对照,分析健康老年人脑功能特异性,寻求区分认知分数的功能影像学指标,探索其分类认知分数优差的可能性,为替代提供研究基础。实验数据来自98名健康老年人和90名健康壮年人,前者来源于葡萄牙健康老年人认知功能的队列研究,在rfMRI扫描前,在认知量表测试分数最优和最差中,分别选出55名和43名作为实验组;后者数据来自哈佛医学院GSP影像组学,年龄在18～35岁之间,在rfMRI扫描前的认知功能评价分数居中,作为对照组。首先,对rfMRI预处理后,计算每人全脑功能连接,构建以脑区为单位的功能连接特异性指数模型,分析老年人脑功能连接与壮年人的偏移程度,统计、对比获得对优、差分数敏感的标志性脑区;然后,以其特异性指数值形成特征向量;最后,应用概率神经网络(PNN)模型对优、差分数组进行分类和N折交叉验证以检验所建指数模型的分类能力。健康老年人脑功能连接特异性指数模型可定位于健康老年人认知分数敏感的标志性脑区,分别处于额叶、颞叶、顶叶中的5个脑区;以这些脑区的指数为特征向量,可有效地区分优、差认知分数,准确度可达81.7%。通过对评价指数的建模并联合机器学习方法,可为rfMRI评估健康老年人认知分数提供有效的评价指标和新方法。     

Developing normal number of small segments-activity clouds of the electromyography interference pattern

Guillain-Barré syndrome (GBS) is an inflammatory polyradiculoneuropathy associated with numerous viral infections. Recently, there have been many case reports describing the association between coronavirus disease-2019 (COVID-19) and GBS, but much remains unknown about the strength of the association and the features of GBS in this setting. We reviewed 37 published cases of GBS associated with COVID-19 to summarize this information for clinicians and to determine whether a specific clinical or electrodiagnostic (EDx) pattern is emerging. The mean age (59 years), gender (65% male), and COVID-19 features appeared to reflect those of hospitalized COVID-19 patients early in the pandemic. The mean time from COVID-19 symptoms to GBS symptoms was 11 days. The clinical presentation and severity of these GBS cases was similar to those with non–COVID-19 GBS. The EDx pattern was considered demyelinating in approximately half of the cases. Cerebrospinal fluid, when assessed, demonstrated albuminocytologic dissociation in 76% of patients and was negative for severe acute respiratory distress syndrome–coronavirus-2 (SARS-CoV-2) in all cases. Serum antiganglioside antibodies were absent in 15 of 17 patients tested. Most patients were treated with a single course of intravenous immunoglobulin, and improvement was noted within 8 weeks in most cases. GBS-associated COVID-19 appears to be an uncommon condition with similar clinical and EDx patterns to GBS before the pandemic. Future studies should compare patients with COVID-19–associated GBS to those with contemporaneous non–COVID-19 GBS and determine whether the incidence of GBS is elevated in those with COVID-19.     

增强乳腺能谱摄影与常规乳腺X线摄影对乳腺良恶性疾病的诊断价值比较

目的探讨比较常规乳腺X线摄影(MG)与对比增强乳腺能谱摄影(CESM)对乳腺良恶性疾病的诊断价值。方法对2018年5月~2020年4月同时完成CESM和MG检查并最终获得病理诊断的74例患者纳入研究，均为女性，年龄22~56岁(41.02±8.24岁)。采用Stenographe Essential全数字化乳腺机，经由上肢静脉注射碘对比剂后采用头尾位(CC位)和内外斜位(MLO位)，一次压迫高低能曝光，得到低能图像和经过特定算法处理的高能减去低能的减影图像，由3名放射科乳腺专业医师对所得图像进行质量分析并做出影像学诊断，以病理为标准，比较CESM与MG对乳腺良恶性疾病诊断差异，并进一步对比两种方法诊断为同一肿瘤分级的诊断符合率差异，分析比较两种方法的诊断效。结果共40例乳腺恶性肿瘤、42例良性病变。MG在诊断良恶性病变的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为77.50%、80.95%、79.48%、70.27%及79.07%，而CESM的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为100%、90.47%、90.90%、100%及95.12%(P < 0.05)。MG在诊断乳腺肿瘤分级3~5级中的诊断符合率分别为79.00%、66.70%、86.70%、85.70%及100%，CESM为100%、92.30%、87.50%、90%及100%(P < 0.05)。结论CESM诊断乳腺良恶性疾病优于MG，尤其是在诊断3级及4A级的肿瘤中。      

多裂肌间隙入路与经皮入路联合伤椎置钉治疗无神经损伤的胸腰段椎体骨折的对比研究

目的 探讨多裂肌间隙入路和经皮入路分别联合伤椎置钉治疗无神经损伤胸腰段椎体骨折的临床疗效。方法 回顾性分析苏州大学附属第一医院2015年1月-2018年1月采用多裂肌间隙入路和经皮入路分别联合伤椎置钉治疗无神经损伤的胸腰段椎体骨折的52例患者的临床资料。经多裂肌间隙入路患者25例(A组),男19例、女6例,年龄35~67 (49.84±9.11)岁;经皮入路患者27例(B组),男20例、女7例,年龄21~66(48.44±11.02)岁。比较两组患者一般资料,以及手术出血量、手术时间、术后镇痛药物使用率、术后下地时间及术后住院时间;手术前后不同时间点的腰背部疼痛视觉模拟评分(VAS);比较两组手术前、术后下地前及术后12个月时伤椎前缘高度比值和矢状位Cobb角变化。结果 两组患者一般资料比较差异均无统计学意义(P值均＞0.05)。均顺利完成手术,术后随访12个月。A组的手术时间、术后下地时间分别为120(90,136)min、2(1,3)d,均短于B组的144(110,220)min、4(2,5)d,差异均有统计学意义(P值均＜0.05);A组术后使用镇痛药物例数(2例)少于B组(15例),差异有统计学意义(P＜0.05);两组患者手术出血量、术后住院时间差异均无统计学意义(P值均＞0.05)。两组患者术后VAS评分均较术前有明显改善,差异均有统计学意义(P值均＜0.01);A、B组间术前、术后12个月VAS评分比较,差异均无统计学意义(P值均＞0.05),但术后第3天VAS评分比较,A组低于B组,差异有统计学意义(P＜0.05)。两组患者术后下地前及术后12个月伤椎前缘高度比值、矢状面Cobb角较术前改善明显,差异均有统计学意义(P值均＜0.05),但两组间同时间点伤椎前缘高度比值和矢状面Cobb角比较差异均无统计学意义(P值均＞0.05)。结论 多裂肌间隙入路和经皮入路分别联合伤椎置钉治疗无神经损伤的胸腰段椎体骨折均取得良好疗效,在改善骨折畸形及远期腰背部疼痛上无明显差异,但经皮入路手术时间更长、术后短期腰背部疼痛更严重、下地时间更晚,相较于多裂肌间隙入路手术并不具有明显优势。     

Construction of the PG-deficient mutant of Fusarium equiseti by CRISPR/Cas9 and its pathogenicity of pitaya

Fusarium is an important plant pathogen and many cell wall-degrading enzymes (CWDEs) are produced in Fusarium-infected plant tissues. To investigate the role of CWDEs in the pathogenicity of pitaya pathogen, we isolated a Fusarium equiseti strain from the diseased pitaya fruit and the activities of CWDEs were determined. The higher polygalacturonase (PG) activity was confirmed both in vitro and vivo. Aiming at the PG gene, the CRISPR/Cas9 system of F. equiseti was constructed and optimized for the first time. Through the process of microhomology-mediated end joining, the flanking region containing 30 bp was used to mediate the homologous recombination of Cas9 double-strand breaks, and the PG gene knockout mutants were obtained by protoplast transformation. Through the phenotypic and pathogenicity experiments of the wild-type strain and mutant strain, the results showed that the colony growth rate and spore production of the strain without the PG gene decreased to some extent, and the lesion diameter and the degree of pericarp cell damage decreased, which showed that the CRISPR/Cas9 system could be used in F. equiseti and PG enzyme and can play a significant role in the interaction between F. equiseti and pitaya fruit.