控制和影响神经干细胞增殖分化为神经元细胞的途径及因素

目的:探讨控制和影响神经干细胞向神经元细胞转化途径的因素。资料来源:应用计算机检索Medline和cnki数据库1990-01/2006-06期间的有关神经干细胞和增殖与分化关系的文献,检索词“NSC,proliferation,differentiation”,并限定文章语言种类为English。同时计算机检索中国生物医学文献数据库1990-01/2006-06期间的相关文献,限定文章语言种类为中文,检索词“神经干细胞、增殖、分化”。资料选择:选取关于影响神经干细胞增殖与分化特别是机制方面的相关文献,删除未进行对照的试验研究的文章,然后查余下的文献全文,进一步判断是否采用对照。纳入标准:平行对照组,即未采用影响神经干细胞增殖与分化的因素或正常对照;实验组为采用干扰神经干细胞增殖与分化的因素。排除明显不随机的试验。质量评价主要考察资料的真实性,调查设计是否严密,实施过程是否严格,统计学处理是否合理。资料提炼:共检索43篇关于神经干细胞增殖与分化分别与基因调控、生长因子、细胞因子及微环境信号等因素密切相关文章,31编符合纳入标准。排除的12篇试验中,8篇是因重复的同一研究,4篇是Meta分析研究。资料综合:神经干细胞是一种具有强大的自我更新能力和多向分化潜能的细胞,它具有分化为中枢神经系统内神经元、星形胶质细胞和少突胶质细胞的能力;其增殖与分化与基因调控、生长因子、细胞因子及微环境信号等因素密切相关,基本螺旋-环-螺旋基因、凋亡相关基因Bc1-XL、sox2等参与了神经干细胞的定向分化机制,notch信号通路、过氧化物酶体增殖分化激活受体Y信号通路也影响神经干细胞的分化方向。结论:神经干细胞的增殖与分化机制尚不十分清楚,其分化及调控机制是多因素调节和多因素相互作用的结果。     

Bronchial artery embolization: monitoring with somatosensory evoked potentials. Work in progress

Surgery remains the treatment of choice for massive and recurrent hemoptysis. In some instances, however, immediate surgical intervention is contraindicated. In these situations, bronchial artery embolization (BAE) has proved to be a successful definitive treatment for non-surgical candidates and a palliative therapy in patients requiring hemodynamic stabilization prior to surgery. The most serious complication of BAE is spinal cord ischemia. This relates directly to the potential anastomotic connections between the bronchial circulation and the anterior spinal artery. Somatosensory evoked potentials (SSEPs) have been used in the past to monitor spinal cord ischemia during procedures that threaten the vascularity of the spinal cord. The authors report two cases in which SSEPs were employed to monitor spinal cord ischemia during bronchial artery embolization.     

The prospects for renal xenotransplantation

Summary: Xenotransplantation of non-human organs into human recipients has long been proposed as a possible strategy to overcome the acute shortage of donor organs. However, vascular organ transplants to humans from phylogenetically disparate species such as the pig are not currently possible due to a rapid rejection process termed hyperacute rejection. This process is initiated by the binding of host pre-formed 'natural antibodies' to the donor vascular endothelium, activation of the host complement system and activation or injury of the donor endothelial cells, leading to intravascular coagulation and loss of the graft due to ischaemic necrosis within minutes to hours of engraftment. Prevention of natural antibody binding and complement activation is viewed as paramount to preventing hyperacute rejection. Even if hyperacute rejection can be prevented, further barriers to successful discordant xenografts such as delayed xenograft rejection and a donor-directed cell-mediated rejection process will still represent major obstacles. This review examines recent advances being made in the various areas of xenograft research and the potential clinical application of pig-to-human xenografts that these strategies may bring.     

Dural infolding during C1-2 myelography

Inward buckling of the dura at C1-2 may occasionally occur with hyperextension of the neck and can result in a difficult or unsuccessful puncture when the posterior lateral C1-2 approach is used for cervical myelography. In this circumstance, placement of the head in a neutral or slightly flexed position may widen the posterior subarachnoid space and facilitate the needle puncture.     

综合疗法治愈狼疮性急性肾衰1例

1　病例报告　患者 ,女 ,6 0岁 ,因反复发热 2 5 a、全身性关节疼痛 2 3 a,双下肢水肿 2 mo,腹胀、尿少 1mo,于 1998- 10 - 2 0入院 .1975年患者出现发热 ,全身关节疼痛 ,四肢关节周围皮肤出现结节性红斑 ,触之疼痛 ,多次化验血沉 115 mm· h- 1 ,抗核抗体阴性 ,类风湿因子阳性 ,未找到狼疮细胞 ,诊断为“类风湿性关节炎”.1986年因上述症状复发再次入我院 ,多次检查后发现血抗核抗体 ( ) ,抗双链 DNA抗体 ( ) ,临床确诊为系统性红斑狼疮 (SL E) ,狼疮性肝炎 ,狼疮性胸膜炎 ,狼疮性肺炎 .经治疗好转 ,但上述症状反复发作 .此次上述症状复…     

急性髓细胞白血病血型变异1例

1　临床资料　患者 ,女 ,6 1岁 ,1999- 0 6 - 0 3日确诊为急性红白血病 (M6 ) .先后 4次住院 ,鉴定血型均为 O型 . 2 0 0 0 - 0 1- 2 2日复诊 ,正反鉴定表明 ,患者红细胞与抗 - B不凝集 ,与抗 - A凝集 ,血清中有抗 - B抗体 (表 1) ,吸收释放试验证实为 A型 (表2 ) .输 A型浓缩红细胞 2 μ,无不良反应 .表 1　血型正反鉴定试剂血清试剂红细胞标本抗 A 抗 B 抗 A+ B Ac Bc Oc被检红细胞 2 + -3+ ---自身血清 -3+ -表 2　吸收、放散试验被检 RBC吸收抗血清后上清被检 RBC吸收抗血清后释放液试剂细胞抗 A修正液抗 B修正液抗 A修正液抗…