转染癌基因的骨髓基质干细胞体外分化特征

目的:观察转染癌基因的骨髓基质干细胞在体外分化情况,为肝细胞癌的细胞源研究提供实验依据。方法:实验于2003-05/2004-06在南方医科大学药理教研室实验室完成。①两步法获取大鼠肝细胞,梯度离心法分离大鼠骨髓基质干细胞。②单基因转染是单独将c-myc或K-ras癌基因瞬时转染大鼠骨髓基质干细胞,6孔培养板中培养,24h后荧光显微镜下观察骨髓基质干细胞转染结果。双基因转染步骤相同,只是将c-myc和K-ras癌基因同时转染大鼠骨髓基质干细胞。③c-myc癌基因转染组、K-ras癌基因转染组、双癌基因转染组常规培养,加入含体积分数为0.1胎牛血清的DMEM培养基,于37℃、体积分数为0.05的CO2孵箱培养,每24h半量更换培养液。④c-myc癌基因转染 肝细胞组、K-ras癌基因转染 肝细胞组、双癌基因转染 肝细胞组将已转染癌基因的骨髓基质干细胞,置于叠加的培养板半透膜的上方(细胞密度均为1×105个/cm2),再将肝细胞置于半透膜的下方(每孔细胞密度为3×105/cm2)进行共培养,其余步骤同常规培养。⑤通过反转录聚合酶式反应和细胞免疫组化检测骨髓基质干细胞分化情况。结果:①癌基因转染24h骨髓基质干细胞检测结果:单独转染c-myc或K-ras癌基因的细胞,其绿色荧光蛋白呈均匀一致分布;双基因转染的细胞,绿色荧光蛋白呈点片状分布。②各组骨髓基质干细胞向肿瘤细胞分化检测结果:c-myc癌基因转染组、K-ras癌基因转染组、双癌基因转染组的骨髓基质干细胞,均未向肿瘤细胞分化;c-myc癌基因转染 肝细胞组、K-ras癌基因转染 肝细胞组、双癌基因转染 肝细胞组的骨髓基质干细胞,均向肝细胞癌发展;空白对照组骨髓基质干细胞细胞均为阴性。此外,双癌基因转染 肝细胞组的骨髓基质干细胞分化增殖迅速,反转录聚合酶式反应和免疫组化检测发现,培养第7天出现甲胎蛋白表达,并迅速增加,而第7天出现的白蛋白和细胞角蛋白18表达迅速减弱,第14天消失。结论:转染癌基因的骨髓基质干细胞,在向肝细胞诱导的条件下,部分癌基因可以使干细胞分化为肝癌细胞;多癌基因转染时,更易于使干细胞分化为肝癌细胞。     

胶原-壳聚糖复合材料的制备及生物安全性检测

目的:制备胶原-壳聚糖复合细胞载体,并对该载体进行系统的生物学性能检测。方法:实验于2003-07/2006-06在天津市医药科学研究所完成。将胶原溶液和壳聚糖溶液按照一定比例(9∶1)混匀,交联后真空冷冻干燥,制成胶原-壳聚糖复合载体,对该载体进行复合材料性状及理化性能检测。并采用急性全身毒性试验、皮内刺激试验、皮肤致敏试验、溶血试验、细胞毒性试验和致突变试验进行生物学性能检测。结果:①胶原-壳聚糖复合材料具有三维立体多孔结构,适合细胞的三维生长,能为新生组织提供良好的支架。②急性全身毒性试验、皮内刺激试验均阴性,致敏率仅为6.25%,细胞毒性为0级,无诱变能力。结论:从仿生学角度出发,制备出可生物降解的胶原-壳聚糖复合材料,经过系统的生物学评价发现,胶原-壳聚糖复合材料具有良好的生物安全性,对机体无毒,不致突变,对细胞有较强的亲和作用,利于细胞生长和分化。     

Seroconversion to human immunodeficiency virus (HIV) in hemophiliacs. Relation to lymphadenopathy

The authors studied the natural history of human immunodeficiency virus (HIV) exposure in 187 hemophiliacs followed for an average of 45 months. Overall, 55 percent developed antibody specific for HIV and 21 percent developed persistent generalized lymphadenopathy. Most patients seroconverted sometime between early 1982 and the end of 1984. Four patients developed acquired immune deficiency syndrome (AIDS) and four seropositive patients developed idiopathic thrombocytopenia (ITP). One of the four patients who developed AIDS and three of the four with ITP had preexisting lymphadenopathy. None of the 10 patients with lymphadenopathy or the 20 asymptomatic patients was seropositive for human T-lymphotropic virus, type I. Although seropositivity and lymphadenopathy have been found in many of the authors' patients, few have developed clinical disease that can be related to HIV infection.     

Platelet concentrates stored for 5 days in a reduced volume of plasma maintain hemostatic function and viability

BACKGROUND: Platelet concentrates prepared from whole blood are generally suspended in a standard volume of 50 to 60 mL of plasma and can be stored thus at 20 to 24 degrees C for up to 5 days. In vitro studies suggested that this plasma volume could be reduced to 30 to 35 mL without impairing platelet function. STUDY DESIGN AND METHODS: This study evaluated whether platelets stored for 5 days in a reduced volume (30-35 mL) of plasma maintained their in vivo viability, hemostatic function, and recovery in recipients. Paired autologous platelet survival studies were done in 20 adult volunteers to assess platelet viability. A rabbit ear bleeding-time model was used to compare the hemostatic effectiveness of human platelet concentrates stored for 5 days in the standard or reduced volume of plasma. Platelet recovery was compared in thrombocytopenic hospital patients. RESULTS: Paired platelet survival studies indicated no significant difference between the values in platelet concentrates stored for 5 days in the reduced volume of plasma and the values in those stored in the standard volume. In the animal model, there was no significant difference in the bleeding times achieved by either set of platelet concentrates. The platelet count increments in thrombocytopenic patients were measured. The platelet count increments in patients who received reduced-volume platelet concentrates were as good as the increments achieved in patients given standard-volume concentrates. CONCLUSION: The in vivo viability, recovery, and hemostatic function of platelets collected in polyvinylchloride plastic containers and stored in 30 to 35 mL of plasma for 5 days are maintained as well as those of platelets stored in 50 to 60 mL of plasma.     

The Hong Kong Society of Rheumatology consensus recommendations for the management of gout

Clinical Rheumatology - Gout is one of the most common noncommunicable diseases in Hong Kong. Although effective treatment options are readily available, the management of gout in Hong Kong remains...     

On the development of the European S3 guidelines on the systemic treatment of psoriasis vulgaris: structure and challenges

Background The development of evidence based guidelines is a demanding and time consuming process. Therefore it is important to share the knowledge and discuss the structure of these guidelines in detail. Objectives To present a method report on the development process of the European evidence based guidelines on the systemic treatment of psoriasis vulgaris with the aim to offer guidance to other guidelines groups with lesser experience and to critically appraise the methodology of the guidelines development process. Methods The guidelines are based on the previously evaluated literature from three European national evidence based guidelines and an additional systematic search and evaluation of new literature. Further steps included a structured consensus conference and a DELPHI procedure to develop the recommendations, as well as several internal and external reviews. All steps were coordinated by the Division of evidence based medicine in cooperation with a group of methodologists. Results A total of 114 studies were included, serving as base for the efficacy chapters of the intervention. The recommendations, based on the efficacy and the level of evidence of the included studies were discussed and finally consented by the guidelines group. After subsequent reviews the guidelines were presented to the European Dermatology Forum, European Academy of Dermatology and Venereology and Union Européenne des Médicins Spécialistes for approval and published in October 2009. Conclusion The development of European evidence based guidelines requires a coordinated structure which can be achieved by the integration of an experienced group of methodologists. Nevertheless further improvements are imaginable and might be considered for an update or other European evidence based guidelines.     

Comparison of measurements obtained with hand files or the Canal Leader attached to electronic apex locators: an in vitro study

AIM: The aim of the present in-vitro study was to combine directly the Canal Leader handpiece (SET, Olching, Germany) with the electronic apex locators ROOT ZX (Morita, Kyoto, Japan) and JUSTY (Yoshida, Tokyo, Japan) to find out whether the working length values thus obtained were identical to those resulting from the combination of the same electronic devices with hand files. METHODOLOGY: A total of 50 natural extracted teeth with single canals and mature apices were used. A radiograph was used as a control and the distance from the radiographic apex to the tip of the file was measured and compared with the results of the electronic length determination. RESULTS: For both electronic devices the differences amongst the distribution of the measurements were not statistically significant under the specified conditions (P > 0.05), indicating that the measurements with hand files and with the Canal Leader were identical for the majority of the cases. CONCLUSIONS: Under the conditions of this study the working length of canals obtained with electronically assisted hand files were similar to those obtained with the electronically assisted mechanical handpiece Canal Leader.