Differences in pathological changes between two rat models of severe traumatic brain injury

The rat high-impact free weight drop model mimics the diffuse axonal injury caused by severe traumatic brain injury in humans,while severe controlled cortical impact can produce a severe traumatic brain injury model using precise strike parameters.In this study,we compare the pathological mechanisms and pathological changes between two rat severe brain injury models to identify the similarities and differences.The severe controlled cortical impact model was produced by an electronic controlled cortical impact device,while the severe free weight drop model was produced by dropping a 500 g free weight from a height of 1.8 m through a plastic tube.Body temperature and mortality were recorded,and neurological deficits were assessed with the modified neurological severity score.Brain edema and bloodbrain barrier damage were evaluated by assessing brain water content and Evans blue extravasation.In addition,a cytokine array kit was used to detect inflammatory cytokines.Neuronal apoptosis in the brain and brainstem was quantified by immunofluorescence staining.Both the severe controlled cortical impact and severe free weight drop models exhibited significant neurological impairments and body temperature fluctuations.More severe motor dysfunction was observed in the severe controlled cortical impact model,while more severe cognitive dysfunction was observed in the severe free weight drop model.Brain edema,inflammatory cytokine changes and cortical neuronal apoptosis were more substantial and blood-brain barrier damage was more focal in the severe controlled cortical impact group compared with the severe free weight drop group.The severe free weight drop model presented with more significant apoptosis in the brainstem and diffused blood-brain barrier damage,with higher mortality and lower repeatability compared with the severe controlled cortical impact group.Severe brainstem damage was not found in the severe controlled cortical impact model.These results indicate that the severe controlled cortical impact model is relatively more stable,more reproducible,and shows obvious cerebral pathological changes at an earlier stage.Therefore,the severe controlled cortical impact model is likely more suitable for studies on severe focal traumatic brain injury,while the severe free weight drop model may be more apt for studies on diffuse axonal injury.All experimental procedures were approved by the Ethics Committee of Animal Experiments of Tianjin Medical University,China(approval No.IRB2012-028-02)in Febru ary 2012.

过表达CXCR4的骨髓间充质干细胞通过增强的肠道归巢能力抑制小鼠肠炎相关肿瘤的形成

背景:骨髓来源间充质干细胞(MSC)用于炎症性肠病(IBD)及IBD相关肠癌的治疗潜力已受到越来越多的关注。然而,MSC究竟是抵制还是促进肿瘤形成仍然存在争议。基质细胞衍生因子1(SDF-1)/C-X-C趋化因子受体4(CXCR4)在MSC归巢过程具有非常关键的作用。本研究旨在评估过表达CXCR4的MSC在IBD瘤变过程中的作用。方法:应用携带CXCR4或绿色荧光蛋白(GFP)的慢病毒载体转染MSC。通过细胞趋化实验和侵袭实验检测CXCR4表达情况。采用偶氮甲烷和葡聚糖硫酸钠(DSS)制作小鼠结肠炎成瘤模型。将实验小鼠分为3组,分别注射磷酸盐缓冲液(PBS)、MSC-GFP或MSC-CXCR4。结果:与MSC-GFP组小鼠相比,MSC-CXCR4小鼠体重下降程度减少,结肠相对更长,肿瘤数量更少,肿瘤负荷减轻;此外,结肠组织中促炎细胞因子表达和STAT3磷酸化水平均下调。结论:过表达CXCR4的MSC表现出抑瘤功能,其机制可能是CXCR4促进MSC向炎性肠组织的归巢。

男性直肠癌患者全直肠系膜切除术后吻合口漏风险增高

背景:患者性别对于直肠癌全直肠系膜切除术(TME)后吻合口漏形成的影响目前仍存在争议。本研究旨在评估性别与吻合口漏的相关性。方法:回顾性分析2010-2014年间在我院接受TME手术且行一期吻合的直肠癌患者的临床资料。比较男性与女性患者术后吻合口漏发生率。结果:入组的956例直肠癌患者中,男性587例(61.4%),女性369例(38.6%)。相较于女性患者,男性患者中吸烟和饮酒的比例更高,但有腹部手术史者较少;术前肠梗阻的比例更高,肿瘤本身也相对较大。全组病例中出现术后吻合口漏81例(8.5%),其中男性患者发生率高于女性患者(10.6%vs.5.1%,P¼0.003)。多因素逻辑回归分析证实,男性是术后吻合口漏发生的独立危险因素(OR¼2.41,95%CI:1.37-4.23,P¼0.002);对于腹腔镜TME手术的亚组分析也得到了相同的结果(OR¼2.11,95%CI:1.15-3.89,P¼0.016)。结论:男性直肠癌患者TME手术后吻合口漏的发生风险相对较高。保护性肠造口或可为吻合口提供保护,降低吻合口漏的发生风险,尤其是对于男性患者。