FoxD3在胚胎发育和维持胚胎干细胞多能性的作用

学术背景：胚胎干细胞无论对转基因动物的制备还是对疾病的治疗都具有巨大的潜能，但前提是用于治疗的胚胎干细胞具有其特有的多能性和全能性，而FoxD3在胚胎发育和维持胚胎干细胞多能性都具有重要作用。目的：了解FoxD3在胚胎发育和维持胚胎干细胞多能性的作用。检索策略：应用计算机检索Pubmed1996—09／2007—05期间的相关文章，检索词为“FoxD3”，限定语言种类为英文。检索到67篇文章，排除重复的和与胚胎发育和胚胎干细胞相关性不大的文章，共纳入32篇文献。文献评价：32篇文献中分别涉及胚胎干细胞转录调节、FoxD3在胚胎发育和维持胚胎干细胞多能性的作用及其Foxd3在其他细胞中（骨髓细胞、神经嵴细胞、色素细胞）的功能等方面的内容,资料综合：胚胎干细胞具有其他细胞不可比拟的特性使胚胎干细胞应用广泛，要合理控制胚胎干细胞在体内和体外的分化，关键要了解那些控制胚胎干细胞命运的基因。FoxD3是叉头框（Forkheadbox，Fox）家族中的一个转录调控因子，它对胚胎上胚层及其衍生物的形成和建立多潜能胚胎干细胞系具有重要作用，并与控制胚胎发育和胚胎干细胞多能性的其他转录调控因子有一定的联系。结论：FoxD3是维持胚胎上胚层细胞多潜能性和在体外建立胚胎干细胞系所必需的。     

睡眠剥夺对力竭运动大鼠胸腺谷胱甘肽、丙二醛、超氧化物歧化酶的影响

目的:观察不同睡眠剥夺时间后力竭运动对大鼠胸腺谷胱甘肽、丙二醛含量和超氧化物歧化酶活性的变化,探讨睡眠剥夺对大鼠抗氧化能力的影响。方法:实验于2006-04/05在湖南师范大学体育学院运动生物化学实验室完成。实验分组:选择10周龄健康雄性SD大鼠30只,按随机数字表法分为5组,每组6只:睡眠非运动组,睡眠 力竭运动组和睡眠剥夺24,48,72h 力竭运动组。实验方法:①采用轻柔刺激法制备大鼠睡眠剥夺模型。②睡眠非运动组和睡眠 力竭运动组不进行睡眠剥夺。③睡眠 力竭运动组和睡眠剥夺各组大鼠运动方案:跑台坡度为10°,速度为19.3m/min(相当于76%VO2max),所有大鼠运动至力竭(运动末期,大鼠先后滞留跑道后1/3处达3次以上,各种刺激驱赶均无效,停跑后体征表现为呼吸急促,神情倦怠,腹卧位,对刺激反应迟钝,捕捉时,逃避反应较运动前减弱)。实验评估:①大鼠一般状态。②力竭时间。③大鼠力竭后麻醉处死,测定胸腺谷胱甘肽、丙二醛含量和超氧化物歧化酶活性。结果:纳入大鼠30只,均进入结果分析。①大鼠一般状态:睡眠 力竭运动组大鼠表现为形态正常,活泼好动,皮毛光亮,眼睛有神;睡眠剥夺48,h 力竭运动组大鼠均出现神态倦怠,眼神黯淡,四肢亦有不同程度的红肿;睡眠剥夺24h 力竭运动组大72鼠介于以上两者之间。②睡眠 力竭运动组和睡眠剥夺24,7248,h组大鼠的力竭时间分别为(232.36±37.67),(269.19±38.61),(162.42±35.70),(141.07±28.56)。③谷胱甘肽含量、超氧化物歧化酶活性:睡眠 力竭运动组谷胱甘肽含量和超氧min化物歧化酶活性均低于睡眠非运动组[分别为(25.54±0.79),(27.09±1.31)mg/g;(±0.21),(±0.10)mkat/g],差异有显4.594.88著性意义(P<0.05);睡眠剥夺24h 力竭运动组谷胱甘肽含量和超氧化物歧化酶活性均高于睡眠非运动组[分别为(28.60±0.96),(27.09±1.31)mg/g;(±0.10),(±0.10)5.234.88mkat/g],差异有显著性意义(P<0.05),睡眠剥夺48,h 力竭运动组P72均低于睡眠非运动组[分别为(23.74±1.19),(22.43±0.52),(27.09±1.31)mg/g;(±0.14),(±0.18),(±0.10)mkat/g],4.523.354.88差异均有非常显著性意义(P<0.01);睡眠剥夺各组与睡眠 力竭运动组间谷胱甘肽含量和超氧化物歧化酶活性差异均有非常P显著性意义(P<0.01);睡眠剥夺各组间比较差异有显著性意义(P<0.05)。④丙二醛浓度:睡眠 力竭运动组丙二醛浓度高于P睡眠非运动组[分别为(±0.27),(±0.24)μmol/L],差异有非常显著性意义(P<0.01);睡眠剥夺各组与睡眠非运动组之间6.565.35P差异均有非常显著性意义(P<0.01);睡眠剥夺24,48,72h 力竭运动组丙二醛含量均高于睡眠 力竭运动组[分别为(±0.12),(±P7.398.850.72),(10.89±0.82),(±0.27)μmol/L],差异有显著性意义(P<0.05;P<0.01);睡眠剥夺各组间比较,睡眠剥夺48h与睡眠剥夺24h差6.56异无显著性意义(P>0.05),睡眠剥夺72h与睡眠剥夺24h、睡眠剥夺72h与睡眠剥夺48h间比较差异有非常显著性意义(P<0.01)。结论:①睡眠剥夺24h可引起大鼠胸腺氧化应激,使氧自由基能力有所增强。②睡眠剥夺48,72h力竭运动后氧自由基能力降低。     

The effectiveness of the confidential unit exclusion option

BACKGROUND: The confidential unit exclusion (CUE) option is intended to reduce human immunodeficiency virus (HIV) transmission by excluding donors newly infected with HIV who have not yet developed HIV antibody (window-period donors); however, its efficacy in excluding window- period donors has not been evaluated. STUDY DESIGN AND METHODS: The use of the CUE option was studied among the donors of 3.7 million units at 18 American Red Cross blood services regions during 1991 and 1992 and among 322 previously HIV-1-seronegative donors who subsequently donated a seropositive unit between 1987 and 1990 at 40 United States blood centers. These seroconverting donors had previously been shown to be highly likely to donate during their window period. RESULTS: On the basis of data from these two populations, it was estimated that only 3 to 5 percent of units donated by window-period donors were not transfused because of the CUE option, that 0.4 percent of all donations were from donors who confidentially excluded their blood from transfusion, and that donors who confidentially excluded their blood were 21 times more likely to be HIV antibody-positive than donors who did not use the CUE option. It is estimated that, if all US blood centers used the CUE option, a total of 2 to 17 otherwise acceptable units donated by window-period donors would not be transfused annually. CONCLUSION: Although donors who confidentially exclude their blood from transfusion are 21 times more likely to have HIV antibody, the rarity of window-period donors and the infrequency of confidential exclusion by window-period donors cause the CUE option to have minimal impact on transfusion safety.     

POLYCYTHAEMIA RUBRA VERA PRESENTING WITH DEPRESSION: RECOGNISING THE SYNDROME ABULIA

SUMMARY A patient with polycythaemia rubra vera is described, presenting primarily with symptoms attributed to depression. While in the ward she developed a stroke, confirmed on CT scan of the head. Venesection alone produced marked improvement in her neurological and psychiatric symptoms. The clinical picture corresponds most accurately to the neurological syndrome of abulia, which is an important differential diagnosis of depression with psychomotor retardation. The pathophysiology of impaired cerebral blood flow causing neuropsychiatrie symptoms in polycythaemia is discussed.     

Mapping of monoclonal antibodies to human factor IX

We used recombinant DNA techniques to map a panel of six monoclonal antibodies (MoAbs) to regions of the human factor IX molecule. A-2 maps to 17 amino acids at the amino terminus of the heavy chain of IXa; 2D5, an inhibitor of clotting, is defined to 36 amino acids of the first EGF- like domain of human factor IX. A-4, A-5, C10D, and FXC008 all map to a region of the heavy chain containing amino acids 180 through 310, suggesting an immunodominant site. FXC008 has been reported to interfere with binding of factor IXa to factor VIII:Ca.     

Evidence that several high-frequency human blood group antigens reside on phosphatidylinositol-linked erythrocyte membrane proteins

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder associated with absence of expression of phosphatidylinositol (PI)- linked membrane proteins from circulating hematopoietic cells of multiple lineages. Recent work demonstrated that decay accelerating factor, one such PI-linked protein, bears the Cromer-related blood group antigens. This study demonstrated that other high incidence antigens, including Cartwright (Yta/Ytb), Holley-Gregory (Hy/Gya), John Milton Hagen (JMH), and Dombrock (Doa/Dob), are absent from the complement-sensitive (PNH III) erythrocytes of patients with PNH. The relatively normal, complement-insensitive erythrocytes from the same patients express these antigens normally. Therefore, these antigens most likely reside on PI-linked proteins absent from PNH III, but not PNH I, erythrocytes.     

Complement-induced vesiculation and exposure of membrane prothrombinase sites in platelets of paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired stem-cell disorder in which the glycolipid-anchored membrane proteins, including the cell-surface complement inhibitors, CD55 and CD59, are partially or completely deleted from the plasma membranes of mature blood cells. To gain insight into the pathogenesis of thrombosis that is frequently observed in this disorder, the procoagulant responses of PNH platelets exposed to the human terminal complement proteins C5b-9 were investigated. C5b-9 complexes were assembled on gel-filtered platelets by incubation with purified C5b6, C7, C9, and limiting amounts of C8. Platelet microparticle formation and exposure of plasma membrane- binding sites for coagulation factor Va were then analyzed by flow cytometry. PNH platelets exhibiting undetectable levels of surface CD59 antigen showed an approximately 10-fold increase in sensitivity to C5b- 9-stimulated expression of membrane-binding sites for factor Va when compared with platelets from normal controls. Expression of catalytic surface for the prothrombinase complex (VaXa) paralleled the exposure of factor Va-binding sites; the rate of prothrombin conversion by C5b-9- treated PNH platelets exceeded that of C5b-9-treated normal controls by approximately 10-fold at the maximal input of C8 tested (500 ng/mL). These data indicate that PNH platelets deficient in plasma membrane CD59 antigen are exquisitely sensitive to C5b-9-induced expression of prothrombinase activity, and suggest that the tendency toward thrombosis in these patients may be due, at least in part, to the deletion of this complement inhibitor from the platelet plasma membrane.