The effect of synthetic oxygen carrier-enriched fibrin hydrogel on Schwann cells under hypoxia condition in vitro

Schwann cell (SC), which plays a key role in peripheral nerve regeneration, is one of the most classic supportive cells in neural tissue engineering. However, the biological activity of SCs seeded in nerve scaffolds decays subsequently due to local hypoxia induced by ischemia. Thus, we aimed to investigate whether a synthetic oxygen carrier-enriched fibrin gel would provide a sustained oxygen release to cultured SCs in vitro for overcoming a temporary (48 h) oxygen deprivation. In this study, perfluorotributylamine (PFTBA)-based oxygen carrying fibrin gel was prepared to provide oxygen for SCs under normoxic or hypoxic conditions. The dissolved oxygen within the culture media was measured by a blood-gas analyzer to quantify the time course of oxygen release from the PFTBA-enriched fibrin gel. SCs were cultured in the presence or absence of PFTBA-enriched fibrin gel under normoxic or hypoxic conditions. The tolerance of SCs to hypoxia was examined by a cell apoptosis assay. The growth of cells was characterized using S-100 staining and a CCK-8 assay. The migration of cells was examined using a Transwell chamber. The mRNA of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glial cell derived neurotrophic factor (GDNF), neural cell adhesion molecule (N-CAM) and vascular endothelial growth factor (VEGF) in SCs were assayed by RT-PCR. In addition, SCs cultured in 3D PFTBA-enriched hydrogel were characterized by Live/Dead staining and the mRNA levels of BDNF, NGF, GDNF, N-CAM and VEGF were assayed by RT-PCR. The results showed that the PFTBA-enriched fibrin hydrogel was able to promote cell adhesion, migration, and proliferation under hypoxic conditions. Interestingly, PFTBA applied through the fibrin hydrogel dramatically enhanced the mRNA of BDNF, NGF, GDNF, N-CAM and VEGF under hypoxic condition. These findings highlight the possibility of enhancing nerve regeneration in cellular nerve grafts through PFTBA increased neurotropic secretion in SCs.     

Transforming growth factor-β1 promotes homing of bone marrow mesenchymal stem cells in renal ischemia-reperfusion injury

Backgrounds: Acute ischemia reperfusion-induced kidney injury is a common cause of acute renal failure, and it is also an important cause of delayed recovery of transplanted kidney functions and even loss of function. However, there is no effective treatment method in clinical applications presently. Objective: The objective was to investigate effects of transforming growth factor-β1 on homing of bone marrow mesenchymal stem cells in renal ischemia-reperfusion injury. Methods: Effects of TGF-β1 over-expression in MSCs on expression of CXCR4 and chemotactic effect to SDF-1 were investigated by in vitro transmembrane chemotaxis. Anti-TGF-β1 antibody was incubated with ischemia reperfusion injury renal tissue homogenate and effects of anti-TGF-β1 antibody were observed. In addition, effects of TGF-β1 gene transfection and anti-CXCR4 antibody treatment in MSCs on expression of SDF-1/CXCR4 axis of renal tissues and damage repair were further explored. Results: Expression of TGF-β1 mRNA in the IRI group increased significantly, and MSCs transplantation could enhance expression of CXCR4 mRNA in rats of the IRI group, the expression of CXCR4 can be decreased by the anti-TGF-β1 antibody and the anti-CXCR4 antibody. TGF-β1 induced homing of MSCs in repair of renal ischemic reperfusion injury by regulating expression of CXCR4 on cell membranes. Blue fluorescence of DAPI-positive MSCs cells of renal parenchyma in the IRI+MSC group was enhanced significantly, which was significantly inhibited by anti-TGF-β1 and anti-CXCR4 antibody, and the inhibitory effect of anti-CXCR4 antibody was more obvious than that of anti-TGF-β1 antibody. Conclusion: Transforming growth factor-β1 promotes homing of bone marrow mesenchymal stem cells in renal ischemia-reperfusion injury, which will provide useful data on role of TGF-β1 in regulating SDF-1/CXCR4 axis-induced MSCs homing.     

上颈椎不稳前路内固定方式的选择

目的:探讨上颈椎不稳前路内固定手术方式的选择及治疗效果。方法:自2000年3月至2010年9月,采用寰枢椎前路内固定手术治疗上颈椎不稳83例,男59例,女24例;年龄20～68岁,平均42岁。其中齿状突螺钉内固定36例,寰枢椎前路经关节螺钉内固定16例,C2,3前路钢板内固定23例,齿状突螺钉联合寰枢椎经关节螺钉内固定5例,齿状突螺钉联合C2,3钢板内固定2例,寰枢椎经关节螺钉联合C2,3钢板内固定1例。结果:1例颈脊髓完全损伤患者,行寰枢椎经关节螺钉内固定,术后1个月死于肺部感染。其余病例获得随访,时间8个月～3年,平均15个月。无椎动脉及脊髓损伤,所有病例寰枢椎获得稳定。36例齿状突螺钉内固定及5例齿状突联合寰枢椎经关节螺钉内固定者,未植骨,齿状突骨性愈合。寰枢椎经关节螺钉内固定病例:1例并发肺部感染死亡;1例齿状突ⅡC型粉碎性骨折并寰枢关节前脱位,齿状突及植骨未骨性愈合,但寰枢关节纤维连接无不稳定表现;1例寰枢椎陈旧性前脱位Ⅰ期前路寰枢椎经关节螺钉内固定,Ⅱ期后路Brooks钢丝内固定后路植骨,寰枢椎骨性融合。其他病例均植骨并获骨性融合。结论:上颈椎不稳患者,根据不同的骨折及不稳类型,选择相应的前路内固定,可取得较好疗效。     

颈前路空心螺钉内固定治疗齿状突骨折

目的 探讨颈前路空心螺钉内固定治疗齿状突骨折的效果.方法 24例齿状突骨折病人,在X线监测下施行颈前路空心螺钉内固定治疗,并分析结果.结果 随访6～40个月,全部病人获得骨性愈合,无明显并发症.结论 齿状突骨折应用前路空心螺钉内固定,可获得良好结果,能保留寰枢椎间的运动功能,并发症发生率低.     

兔寰枢椎前脱位不全脊髓损伤早期细胞凋亡的实验研究

目的制备伴脊髓不全损伤兔寰枢椎前脱位模型,观察模型早期脊髓神经细胞凋亡的变化。方法建立伴脊髓不全损伤兔寰枢椎前脱位模型,采用原位末端转移酶标记技术（terminal deoxynucleotidyl transferase-mediatednick-end labeling,TUNEL）检测术后6 h、24 h、72 h损伤节段脊髓细胞的形态及数量变化。结果伤后6 h,损伤节段脊髓可见阳性神经细胞大量表达,至24 h损伤段阳性神经细胞达高峰,持续至72 h阳性神经细胞数见下降。各时间点与假手术组比较,损伤段脊髓神经细胞凋亡数均增加（P〈0.05）,凋亡的神经细胞数在24 h较6 h、72 h均更多（P〈0.05）。结论通过手术方式可成功制备寰枢椎前脱位并脊髓损伤模型,在模型寰枢椎可靠固定的前提下（未复位）,脊髓损伤逐渐加重,脊髓损伤后广泛存在细胞凋亡。     

兔体感诱发电位正常参考值研究

目的测定正常成年日本大耳白兔神经皮层体感诱发电位（somatosensory evoked potential,SEP）,建立本实验室SEP正常值数据库,为相关的临床和基础研究提供实验参数。方法选择日本大耳白兔30只,雌雄各半。选用英国牛津NHK30-Medelec Synergy肌电诱发电位术中监护仪。采用腹腔注射水合氯醛进行麻醉。测量日本大白兔皮层体感诱发电位正向波（P1）、负向波（N1）的正常值。结果 30只日本大白兔均检测出清晰辨认的波形。在头皮记录到较一致的,由一个P1和一个N1组成的体感诱发电位。潜伏期为P1（12.32±1.73）ms,N1（21.95±1.88）ms;P1N1复合波波幅为（2.02±1.56）μV。结论 SEP测量值较稳定,为进一步研究SEP的病理变化提供了实验依据。     

创伤诱发颈椎后纵韧带骨化症发病的临床研究

目的 探讨创伤诱发颈椎后纵韧带骨化症(OPLL)发病的临床特点及其转归.方法 对56例由创伤诱发的颈椎OPLL的临床资料进行回顾性研究,主要分析其临床症状、体征及其影像学表现.其中前路手术8例,后路手术44例,并按JOA评分标准判断其术后改善率.结果 48例(85.7％)在创伤前感颈部僵硬、活动不灵活,44例(78.6％)出现括约肌功能障碍,35例(62.5％)MRI信号改变.前路手术平均改善率为62.1％;后路手术平均改善率为52.3％;脊髓信号发生改变的35例,平均改善率为42％.4例非手术治疗,2例死亡.结论 创伤是诱发颈椎OPLL发病的重要原因,该病起病急、病情重、预后差;早期手术治疗是促进神经功能恢复的重要途径.     

284名试用期护生工作倦怠感现状调查与分析

目的了解试用期护生工作试用期间的职业倦怠状况,帮助其树立积极向上的正面情绪,减轻或消除工作倦怠感。方法采用问卷调查法,对武汉市3所三级医院、4所二级医院的284名试用期护生工作倦怠状况进行了调查,并与杭州市地区群体护士常模进行比较分析。结果试用期护生情感衰竭及去人格化两个维度上属低度倦怠,个人成就感维度属高度倦怠。情感衰竭及去人格化维度倦怠程度得分低于杭州市护士群体,个人成就感维度倦怠感高于杭州市护士群体,差异均有统计学意义（P〈0.01）。急诊科试用期护生情感衰竭及去人格化维度倦怠感高于其他组;急诊科试用期护生个人成就感维度倦怠感低于其他组;三级医院护生去人格化维度倦怠感高于二级医院,差异有显著统计学差异（P〈0.01）;不同学历、有无护士执照方面差异无统计学意义（P〉0.01）。结论建议管理者从试用期护生的工作阶段特殊角度出发,减轻或消除职业倦怠感,从而提高试用期护生的工作积极主动性,为优质护理服务的更好延续打下坚实基础。     

经皮Herbert螺钉治疗新鲜腕舟骨骨折

目的探讨经皮Herbert螺钉内固定治疗新鲜腕舟骨骨折的临床疗效。方法对本院2004年1月~2010年10月期间采用Herbert螺钉内固定治疗的18例新鲜腕舟骨骨折病例进行回顾性分析。骨折根据Herbert分型A2型10例,B2型6例,B3型2例。结果所有病人均获随访,随访时间为5~18个月,平均8个月,骨折均获骨性愈合。按改良Mayo腕关节功能评分,优12例,良5例,尚可1例,优良率为94%。结论对急性腕舟骨骨折患者采用经皮闭合复位Herbert螺钉内固定治疗,效果满意,具有疤痕小,重返工作时间短的优势。     

构建组织工程骨与生物蛋白胶双相接种法的实验研究

目的观察采用生物蛋白胶（fibrin glue,FG）双相接种技术促进组织工程骨体外构建的可行性。方法以生物蛋白胶为介质,用双相接种技术将羊骨髓间充质干细胞（mesenchymal stem cells,MSCs）与同种异体冻干脱钙骨基质（freeze-dried demineralized bone matrix,FDBM）复合,在体外构建组织工程骨,以静置接种法作为对照。通过细胞计数、光学和电子显微镜及四甲基偶氮唑盐比色法（methyl thiazolyl tetrazolium,MTT）检测观察细胞在支架材料上的粘附、生长情况。结果双相接种法在不同接种密度时都可保持细胞上架率维持在80%左右,上架细胞的数量随接种细胞密度增加成比例增加;FG对细胞的增殖没有明显影响,提高接种密度使细胞生长曲线提前达到平台期,各组的细胞数量峰值接近。结论双相接种技术可显著提高种子细胞的上架效率,可以作为一种体外构建组织工程骨的好方法。