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.     

Effect of bisphosphonates on nitric oxide production by inflammatory activated chondrocytes

OBJECTIVE: Bisphosphonates have been reported to possess anti-inflammatory and cartilage protective effects in animal arthritis models but not much is known about their direct effect on chondrocytes. In this study we evaluate the effect of bisphosphonates on nitric oxide (NO) production by activated chondrocytes. METHODS: Isolated bovine chondrocytes and bovine cartilage explants were used. In the second part of the study human cartilage explants (osteoarthritis (OA) and non-OA cartilage) were used. The isolated chondrocytes and cartilage explants were pre-incubated with clodronate, pamidronate or risedronate and stimulated with IL-1 and TNF-alpha (10 ng/mL, 48 h). NO production was quantified using the Griess assay. RESULTS:In bovine cultures, clodronate (10(-4)mol/L) and pamidronate (10(-6)mol/L) showed a small inhibition of NO production (up to 15 % and 25% respectively), whereas risedronate had no effect.In the human cartilage cultures no effect of BPs on the NO production was detected except for the highest concentration of clodronate tested (10(-4)mol/L) which demonstrated a small enhancement (19%) in NO production reaching significance in the non-OA group. CONCLUSION: BPs have a modest effect on NO production by inflammatory activated chondrocytes only in the higher concentrations, indicating that the clinical relevance of these effects is probably negligible.     

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...     

Basophil activation test by flow cytometry: present and future applications in allergology

The diagnosis of allergic reactions in clinical practice rests upon both clinical history and the demonstration of specific immunoglobulin E (sIgE), either in the serum or via skin tests. However, for various reasons, identification of the offending allergen(s) is not always possible. Moreover, not all allergies are IgE-mediated. In an attempt to find reliable methods to investigate hypersensitivity reactions, histamine and sulfidoleukotriene release tests have long been introduced. However, relatively few comprehensive quality reports have been published so far. Upon challenge with a specific allergen, basophils not only secrete quantifiable bioactive mediators but also upregulate the expression of different markers which can be detected efficiently by flow cytometry using specific monoclonal antibodies. This review addresses the principals, particular technical aspects and pitfalls as well as the clinical and research applications of flow-assisted analysis of in vitro activated basophils.     

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.