一氧化氮在神经退行性疾病中的作用:非类固醇性抗炎药的治疗前景(英文)

一氧化氮(nitric oxide, NO)是一类胞内信使。研究表明,神经退行性病人脑组织中催化合成NO的酶的表达水平显著提高,提示NO与神经退行性疾病密切相关。此外,在这些组织中还检测到硝化的蛋白,提示NO在这些组织中具有生物活性。在神经免疫应答中,神经元和胶质细胞(包括小胶质细胞和星形胶质细胞)内都发生了NO水平的改变。很多神经退行性疾病都伴随有神经炎症,抑制神经炎症的信号通路能延迟这些疾病的发展。因此,NO及其释放通路已逐渐成为神经退行性疾病研究领域的热点,对它们的理解能帮助我们找到合适的方案来预防、减缓或者治愈这些疾病。     

Induced abortion is not a cause of subsequent preterm delivery in teenage pregnancies

To examine the possible impact of previous induced abortion on the occurrence of preterm delivery in the subsequent pregnancy in teenage women, a retrospective case-control study was performed on mothers aged 13-19 years who delivered in one tertiary hospital over a 4 year period. Those who had a history of induced abortion prior to the index pregnancy were identified from the records and compared with a control group without previous induced abortion and who were matched for maternal age and parity. Of the 118 cases thus identified, 28 (23.7%) had more than one induced abortions and 18 (15.3%) had one or more induced abortions in the second trimester. There were 10 (8.5%) para 1 cases. No significant differences could be demonstrated between the study and control groups in the maternal demographics, major pregnancy complications, or perinatal outcome, except for the incidence of smokers which was significantly higher (39.0 versus 14.4%, P < 0.02) in the study group. The number of previous induced abortions did not appear to be related to the incidence of preterm labour, which was 10.2 and 8.5% in the study and control groups respectively. Our findings indicate that previous induced abortion is not a significant cause of preterm labour and delivery in teenage pregnancies.      

Prognostic factors for an unsatisfactory primary methotrexate treatment of cervical pregnancy: a quantitative review

To determine the risks when the primary methotrexate (MTX) treatment of cervical pregnancy has an unsatisfactory outcome, we conducted a Medline search on relevant literature published from January 1983 to June 1997. The search yielded 28 publications of 48 cases of cervical pregnancy. These and four new cases from our institutions were used in our study. A cervical pregnancy that presented with a serum beta-human chorionic gonadotrophin concentration of > or = 10,000 mIU/ml [odds ratio (OR) 10.82, 95% confidence interval (CI) 2.59, 45.14], gestational age at > or = 9 weeks (OR 6.44, 95% CI 1.46, 28.52), embryonic cardiac activity (OR 14.29, 95% CI 2.95, 76.92), and crown- rump length of >10 mm (OR 13.33, 95% CI 1.46, 120.48) was considered to be associated with a higher unsatisfactory rate of primary MTX treatment. A concomitant feticide was found to enhance the therapeutic effect of MTX treatment if embryonic cardiac activity was evident (OR 0.13, 95% CI 0.02, 0.68). Administration of a high dose of MTX did not seem to be more effective than a lower one. Our findings supported some previous observations and, more importantly, provided useful clinical information in selecting appropriate candidates for MTX treatment in cases of cervical pregnancy.      

Endothelium dependence of prostanoid-induced relaxation in human hand veins

The endothelium dependence of prostanoid-induced relaxation was examined in human isolated hand veins precontracted by endothelin. Indomethacin (10^-6 mol l^-1) and the thromboxane A₂-receptor antagonist BM 13.505 (10^-6 mol l^-1) were present throughout. The endothelium was removed by insufflating carbogen through the vessel lumen. Prostaglandin (PG) F_2α, PGE₁ PGE₂, and prostacyclin (PGI₂) elicited concentration-dependent relaxant effects. Removal of the endothelium reduced the relaxation induced by PGE_2α and PGE₂, but not that elicited by PGE₁ and PGI₂. The order of potency was PGE₂? PGE₁? PGI₂? PGF_2α regardless of the presence or absence of endothelium. The relaxation elicited by an acidified solution of NaNO₂ (generating nitric oxide) was almost identical in intact and endothelium-denuded vein segments. The results are compatible with the existence of two prostanoid receptor populations mediating relaxation: (1) one located on the smooth muscle cells and; (2) another present on the endothelium or possibly on the smooth muscle and modulated by the endothelium. The latter receptor appears to be activated by PGF_2α and PGE₂, but not by PGE₁ and PGI₂.     

Guidelines on the selection and use of therapeutic products to treat haemophilia and other hereditary bleeding disorders

Summary. Evidence based guidelines are presented on the selection and use of therapeutic products to treat haemophilia. These guidelines offer advice based on the best published scientific and medical information. They will be reviewed regularly by UKHCDO Advisory Committee. Included are details of therapeutic products available in the UK to treat patients with haemophilia and other bleeding disorders and the background information on which the recommendations are based are presented.     

脐血间充质干细胞体外培养方法的改良及其成骨分化能力

目的:采用两种改良方法体外分离培养脐血间充质干细胞,并观察其成骨分化能力。方法:实验于2006-05/09在上海交通大学医学院附属第九人民医院骨与关节中心细胞实验室完成。①所用28份脐血标本由复旦大学医学院附属妇产科医院提供,取自足月健康顺产新生儿,产妇和家属均书面同意,实验经医学伦理委员会批准。②采集28份脐血标本,50～90mL/份,枸橼酸抗凝。采集后12h内密度梯度离心法分离出单个核细胞,接种于100mm×20mm培养皿中,细胞浓度为1×1010L-1,置于含体积分数为0.1胎牛血清的α-MEM培养液中原代培养,5～7d后半量换液,后每隔3～4d全量换液一次。③细胞贴壁后,分两组予以改良培养。改良1组10份,当培养皿底圆形巨核细胞融合、梭形成纤维样细胞脱落时将细胞悬液移入新的培养皿中培养;改良2组18份,待培养皿底圆形巨核细胞渐渐占据优势时,将培养基更换为含体积分数为0.15小牛血清的α-MEM,当圆形巨核细胞大部脱落后换回含体积分数为0.1胎牛血清的α-MEM培养基。成纤维样细胞融合至80%～90%时胰酶消化,按1∶2或1∶3传代培养。④显微镜下观察脐血间充质干细胞的形态。取第5代脐血间充质干细胞,采用流式细胞仪测定细胞免疫表型,以碱性磷酸酶法检测成骨分化能力。结果:①28份脐血间充质干细胞中,共20份原代培养中出现贴壁细胞(改良1组6份,改良2组14份),其中13份培养出能融合且可稳定传代的成纤维样细胞(改良1组4份,改良2组9份),成功率46.4%。②原代培养5～7d后贴壁细胞呈梭形成纤维样细胞和圆形巨核细胞。改良1组与2组于原代培养5周可见成纤维样细胞集落,细胞形态与骨髓间充质干细胞相似,呈较均一的长梭形,传至22代形态无明显变化。③可强烈表达CD29、CD105等间充质干细胞表面标志,而不表达CD34、CD45和CD106等造血干细胞和内皮细胞标志。④成骨诱导1周,脐血间充质干细胞可分化为成骨细胞,碱性磷酸酶染色呈阳性。结论:脐血中存在的单个核细胞经过改良培养后,可提高脐血间充质干细胞的培养成功率。脐血间充质干细胞具有与其他来源的单个核细胞类似的表型及成骨分化潜能,且易于体外扩增、传代稳定。     

Feature specific segmentation in perceived structure-from-motion.

Motion information is important to vision for extracting the 3-D (three-dimensional) structure of an object, as evidenced by the compelling percept of three-dimensionality attainable in displays which are purely motion-defined. It has recently been shown that when subjects view a rotating transparent cylinder of dots simulated with parallel projection, they rarely perceive rotation reversals which are physically introduced (Treue, Andersen, Ando & Hildreth, Vision Research, 35;1995:139-148). We show however that when the elements defining the cylinder are oriented, the number of perceived reversals increases systematically to near maximum as the difference between element orientations on the two surfaces increases. These results imply that structure-from-motion mechanisms are capable of exploiting local feature differences between the different surfaces of a moving object.     

猪源性异种骨支架材料的生物相容性

目的:异种骨来源广泛,价格低廉,经过适当处理既能保留骨诱导作用,并作为骨支架使其具有骨传导作用。检测猪源性骨支架材料与人源性骨支架材料的生物相容性有无明显差异,为猪源性骨支架材料取代人源性骨支架材料提供实验依据。方法:实验于2006-08/2007-03在南方医科大学人体解剖学系实验室(广东省组织构建与检测重点实验室)完成。①实验材料:人源性、猪源性骨支架材料(为课题组前期制备);脂肪源间充质细胞(前期培养)。②实验方法及评估:体外细胞毒性实验:提取人源性、猪源性骨支架材料浸提液,用此浸提液培养脂肪源间充质细胞,并用无浸提液的DMEM培养基做对照,镜下观察细胞生长状况,流式细胞术检测细胞生长周期;人源性、猪源性骨支架材料皮下植入试验:于8只新西兰大白兔皮下,脊柱左侧植入异种骨支架材料,右侧植入同种异体骨支架材料。分别于4,8,12,16周将植入材料连同周围组织取出,进行组织切片观察及电镜观察。对动物处置符合动物伦理学标准。结果:①体外细胞毒性实验结果:在同一时间点,浸提液组、正常培养组细胞生长状况均良好,未见明显细胞抑制;流式细胞术检测细胞周期,3组细胞G1、G2、S期细胞百分率差异无统计学意义(P>0.05)。②皮下植入实验结果:组织切片光镜及电镜观察,4周两种植入材料周围均见结缔组织包绕,有大量巨噬细胞、浆细胞、中性粒细胞、单核细胞浸润,材料表面光滑,与结缔组织界限清楚;8周时炎症反应减轻,可见部分材料开始降解,材料表面稍显粗糙,有少量结缔组织长入材料内部;12周炎症反应基本消失、材料降解明显、异位成骨趋势明显,材料表面更加粗糙,周围有大量结缔组织长入材料;16周均无炎症反应,两种材料大部分降解,并且猪源性骨支架材料降解更为迅速,均有新骨形成,材料表面粗糙程度较12周时为甚,骨支架材料基本消失。结论:猪源性异种骨支架材料有良好的生物相容性,与人源性异种骨支架材料无明显差别。