NOD鼠腹腔巨噬细胞肿瘤坏死因子α和白细胞介素水平变化与吡格列酮的干预效应

目的:观察含0.02%吡格列酮的饲料对NOD鼠糖尿病发病率的影响,分析巨噬细胞在吡格列酮预防NOD鼠糖尿病中的作用。方法:实验于2003-01/2005-01在中南大学湘雅二医院动物实验室及中心实验室完成。4周龄NOD雌鼠56只,随机数字表法分为吡格列酮组(n=25)和对照组(n=26),分别摄食含0.02%吡格列酮的混合饲料和普通营养饲料。自10周龄开始,每周测尿糖1次,尿糖阳性后用血糖仪测血糖,连续两次血糖≥16.7mmol/L即诊断为糖尿病。两组各取12周龄NOD雌鼠15只,处死前4d腹腔注射30g/L的硫代乙醇酸钠2mL,麻醉后摘除眼球法处死小鼠后腹腔灌洗收集巨噬细胞,加入脂多糖共同培养24d后收集上清,ELISA法测细胞因子肿瘤坏死因子α、白细胞介素6水平。结果:小鼠56只全部进入糖尿病发病率分析;进入腹腔巨噬细胞肿瘤坏死因子α、白细胞介素6的水平结果分析20只。①30周龄时,对照组25只小鼠有20只发生了糖尿病,发病率80.0%,平均发病时间为(139.2±38.2)d;吡格列酮组26只中有14只发生了糖尿病,发病率为53.8%,平均发病时间为(153.0±28.1)d,与对照组相比,吡格列酮组发病率明显降低(P<0.05)。②12周龄时对照组NOD鼠腹腔巨噬细胞肿瘤坏死因子α、白细胞介素6水平与吡格列酮组差异无显著性意义[(537.4±112.49),(448.9±92.18)ng/L;(551.2±108.23),(461.7±80.49)ng/L,P>0.05]。结论:吡格列酮在一定程度上预防和延缓NOD鼠糖尿病的发生;吡格列酮对NOD鼠糖尿病和胰岛炎的预防作用可能与巨噬细胞无明显关系。     

Quantitation of CD62, soluble CD62, and lysosome-associated membrane proteins 1 and 2 for evaluation of the quality of stored platelet concentrates

BACKGROUND: Platelets become activated during storage, which results in secretion of granules, vesiculation of microparticles, secretion of protein, and a number of other biochemical and morphologic processes that decrease the utility of platelet concentrates stored for transfusion. STUDY DESIGN AND METHODS: To evaluate the quality of stored platelet concentrates, the cell surface expression of specific activation-dependent antigens (CD62 and lysosome-associated membrane proteins 1 and 2 [LAMP-1, LAMP-2]) on platelets stored in a hospital blood bank over a 7-day period was examined. Relative microparticle counts and the expression of CD62 by microparticles, as well as platelet concentrate supernatant levels of soluble CD62, were determined. RESULTS: The percentage of platelets expressing CD62 increased significantly from Day 1 to Day 5 (p < 0.05) of storage; the mean fluorescence values for CD62 did not. In contrast, the mean fluorescence values of LAMP-1 and LAMP-2 rose significantly (p < 0.01 and p < 0.05, respectively) between Days 1 and 5. Significant declines in CD62, LAMP-1, and LAMP-2 percent expression and mean fluorescence were seen on Day 6 of storage (p < 0.001). Microparticle numbers increased significantly during storage and correlated with levels of CD62 protein (free and membrane-bound) (r = 0.95 vs. Day 2, p < 0.05; r = 0.88 vs. Day 5, p < 0.05). CONCLUSION: Flow cytometric evaluations of the expression of cell surface CD62, LAMP-1, and LAMP-2 are complementary tests that, especially when used in conjunction with the quantitation of CD62 protein, provided a simple and effective means of evaluating the quality of platelet concentrates stored for transfusion.     

Red cell alloimmunization in multitransfused HLA-typed patients

The authors studied retrospectively the formation of clinically significant red cell (RBC) alloantibodies in 958 HLA-typed, multiply transfused patients receiving kidney (603 patients) or liver (263 patients) transplants or plateletpheresis transfusions (92 patients). RBC alloantibodies were found in 91 (9.5%) of these patients and multiple antibodies in 35 (3.7%). Rh (D, C, c, and E) antibodies accounted for 49 percent of the total and Kell antibodies for 31 percent. Antibodies were found in 15 percent of apheresis recipients and in 8.6 percent of renal and 9.5 percent of liver transplantation patients. No association was found between any HLA-A, HLA-B, or HLA-DR phenotype and the presence of RBC alloantibodies, either in general or when analyzed according to the specific antibody. Renal transplant patients with RBC alloantibodies were somewhat more broadly HLA-alloimmunized than were those without RBC alloantibodies. Patient gender did not affect these results. The authors concluded that the immune response to RBC alloantigens is independent of HLA type but is associated with an increased level of HLA antibody formation.     

乙交酯-丙交酯共聚物-细胞复合体移植治疗脊髓损伤

目的:观察神经干细胞、许旺细胞和组织工程支架材料乙交酯-丙交酯共聚物于大鼠髓内共移植后的生物相容性,及其对大鼠损伤脊髓形态和功能的修复作用。方法:实验于2005-05/2006-09在首都医科大学附属北京市神经外科研究所损伤修复实验室完成。①实验材料:健康成年雌性Wistar大鼠36只,随机数字表法分为单纯支架组、神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组,12只/组。乙交酯-丙交酯共聚物由中科院化学研究所医用高分子材料中心提供。②实验方法:各组大鼠均建立脊髓T9半横断损伤模型。神经干细胞 许旺细胞 支架复合体组取2×1010L-1的许旺细胞、神经干细胞各10μL接种于乙交酯-丙交酯共聚物支架内,神经干细胞 支架复合体组取2×1010L-1的神经干细胞10μL接种于乙交酯-丙交酯共聚物支架内,单纯支架组取10μLDMEM培养液置于乙交酯-丙交酯共聚物支架内,于脊髓缺损处分别植入对应的复合物。③实验评估:应用电镜观察乙交酯-丙交酯共聚物支架的降解及轴突的再生状况;应用BBB评分和电生理技术检测大鼠脊髓功能性的恢复情况。结果:36只Wistar大鼠均进入结果分析。①行为学观察结果:移植术后4,12周,神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组大鼠的后肢运动功能BBB评分均好于单纯支架组(P<0.01),其中神经干细胞 许旺细胞 支架复合体组尤为明显。②神经电生理检查结果:在脊髓半横断损伤后即刻,所有动物的体感诱发电位和运动诱发电位波幅都明显减低甚至消失。移植术后4周,神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组大鼠的体感诱发电位和运动诱发电位波幅均有所恢复;至移植术后12周恢复明显。单纯支架组移植术后4,12周体感诱发电位和运动诱发电位波幅无明显变化。③电镜观察结果:扫描电镜下,随着时间的延长各组植入的乙交酯-丙交酯共聚物逐渐降解。透射电镜下,各组植入材料正中横断面可见新生的无髓及有髓神经纤维,至12周时神经干细胞 许旺细胞 支架复合体组最明显。结论:乙交酯-丙交酯共聚物在大鼠损伤的脊髓内具有良好的生物相容性;其与神经干细胞、许旺细胞共移植能够明显促进脊髓半横断损伤大鼠的脊髓轴突再生,并改善肢体的运动功能。     

The virtues of vitamin D—but how much is too much?

Vitamin D deficiency is common in healthy adults and children as well as in the chronic kidney disease (CKD) population. What was once a disease of malnourished children in the developing world has re-emerged and reached pandemic proportions. In parallel with this development, there is a growing awareness that vitamin D is not simply a ‘calcaemic hormone’ but plays an important role in the prevention of cardiovascular disease, infectious and auto-immune conditions, renoprotection, glycaemic control and prevention of some common cancers. Most tissues in the body have a vitamin D receptor and the enzymatic machinery to convert ‘nutritional’ 25-hydroxyvitamin D to the active form 1,25-dihydroxyvitamin D; it is estimated that 3% of the human genome is regulated by the vitamin D endocrine system. Although there are few well-conducted studies on the benefits of vitamin D therapy, an exuberant use of vitamin D is now seen in the general population and at all stages of CKD. There is emerging evidence that vitamin D may in fact have a therapeutic window, and at least from the effects on the cardiovascular system, more is not necessarily better. In this review, we discuss the role of nutritional vitamin D (ergocalciferol or cholecalciferol) supplementation in CKD patients, interpreting the clinical studies in the light of the vitamin D metabolic pathway and its pluripotent effects. While nutritional vitamin D compounds clearly have numerous beneficial effects, randomised controlled studies are required to determine the effectiveness and optimal dose at different stages of CKD, its concurrent use with activated vitamin D compounds and its safety profile.     

Immunosuppression among HIV‐1‐positive patients attending for care: experience from two large HIV centres in the United Kingdom

Objectives

The aim of the study was to describe the prevalence of and examine the factors associated with immunosuppression (CD4<200 cells/μL) among HIV‐infected patients attending two large inner London treatment centres.

Methods

Patients attending for care who had a CD4 count <200 cells/μL during a 6‐month period (1 January to 30 June 2007) were identified from the UK national CD4 surveillance database. Corresponding case notes were reviewed and factors associated with the most recent immunosuppressive episode examined. Patients either previously had a CD4 count >200 cells/μL at any time under follow‐up which had decreased (group A) or never had a CD4 count >200 cells/μL (group B; late presenters).

Results

Of 4589 patients, 10.2% (467) had at least one CD4 count <200 cells/μL. In group A (60.1% of patients), 70.4% were not receiving antiretroviral therapy (ART) at the time at which the CD4 count fell to <200 cells/μL. Reasons included: treatment interruption (TI; 32.6%), patient declined ART (20.2%), infrequent attendance (19.1%), physician delay in offer (23.1%) and transient CD4 cell count decrease (3.9%). Among those receiving ART, one in three had poor adherence. In group B, 92.3% had started ART after presentation: most had recently started and were responding virologically. AIDS‐defining diagnoses occurred in the year preceding the decrease in CD4 cell count in 12.6% of patients in group A and 33.3% of those in group B.

Conclusion

The majority of patients became immunosuppressed while under care. Our findings suggest that, in addition to strategies aimed at earlier diagnosis, there are further opportunities to reduce severe immunosuppression in patients already attending for HIV care.