Incidence of and risk factors for severe liver toxicity in HIV-infected patients on anti-tuberculosis treatment.

OBJECTIVE: To assess the incidence and risk factors for severe liver toxicity in human immunodeficiency virus (HIV) infected patients on anti-tuberculosis treatment and the impact of patients' characteristics and concomitant medications instituted during the first week of antituberculosis treatment. METHODS: HIV-infected patients referred to six French hospitals between 1 January 1992 and 31 December 2004, with confirmed or 'presumptive' tuberculosis (TB). Liver toxicity was studied during the first 2 months of TB treatment. RESULTS: During the 12 years of the study period, 144 patients were enrolled. Severe liver toxicity developed in 15 (10.7%). The median time to development of liver toxicity was 14 days. In the univariate analysis, high baseline bilirubin levels (P = 0.004), CD4 cell counts between 50 and 100 cells/mm3 (P = 0.022) and the use of fluconazole (P = 0.0005) were associated with liver toxicity. In the multivariate analysis, independent risk factors were abnormal baseline alanine aminotransferase (ALT) (P = 0.028) and bilirubin levels (P = 0.033) and the use of fluconazole (P = 0.008). CONCLUSION: Severe liver toxicity is frequent, and occurs early in the course of anti-tuberculosis treatment. ALT and bilirubin levels should be closely monitored during the first month of treatment, especially in patients with high baseline ALT or bilirubin levels. We suggest caution when prescribing fluconazole and anti-tuberculosis drugs concomitantly, although this needs to be confirmed and further investigated.     

Community-acquired bacteraemic pneumococcal pneumonia in adults: effect of diminished penicillin susceptibility on clinical outcome

Pneumococcal pneumonia remains a common disease with a high mortality rate. Between 1995 and 2000, we prospectively analyzed 95 consecutive adult cases of community-acquired bacteraemic pneumococcal pneumonia treated in a single centre. The incidence of pneumococcal resistance to penicillin increased from 19 to 50% during the study period. Multivariate analysis showed that only age and recent hospitalization were independently associated with fatal outcome. The proportion of penicillin-resistant strains was slightly but not significantly higher among patients who died before the fourth hospital day than among those who died later. Patients who died before D4 were more likely to have a recent history of hospitalization, cancer and/or chemotherapy. It thus appears that infection by a resistant pneumococcal strain is not in itself a gravity factor in this setting, but that their acquisition is associated with pejorative clinical features.     

Core2 beta-1,6-N-acetylglucosaminyltransferase enzyme activity is critical for P-selectin glycoprotein ligand-1 binding to P-selectin

P-selectin glycoprotein ligand-1 (PSGL-1) is a high-affinity counterreceptor for P-selectin on myeloid cells and activated T-cells. In addition, PSGL-1 can serve, both in vitro and in vivo, as an E- selectin ligand. Appropriate glycosylation of PSGL-1 is crucial for binding to P-selectin. Functional PSGL-1 is known to bear sialyl lewis X (SLex) or a closely related oligosaccharide. In this study, we show that Chinese hamster ovary (CHO) cells expressing PSGL-1 and fucosyltransferase show a dramatic increase in binding to P-selectin when transfected with "core2" transferase, the enzyme that initiates branching of O-linked glycans. Moreover, only PSGL-1 from core2 transfectant CHO cells can be affinity-captured with P-selectin, suggesting that branched O-linked glycans are required for high- affinity binding to P-selectin. Analysis of PSGL-1-derived O-linked oligosaccharides produced in core2 transfected cells shows the presence of more elaborated glycans. Interestingly, transfection of core2 in these cells does not alter binding to E-selectin.     

Trimetazidine-induced encephalopathy with choreiform disorders: a case report

Trimetazidine is known to induce parkinsonism but choreiform disorders have not yet been described with this drug. A 88-year-old patient treated with trimetazidine developed choreiform movements, gait disorders, tremor and visual hallucinations. These symptoms disappeared after drug withdrawal. Although this drug contains a piperazinic ring like other anti-dopaminergic drugs which are already known to potentially induce chorea like neuroleptics and some anti-convulsive drugs. When a patient treated with trimetazidine develops or worsens motor disorders (parkinsonism or choreiform disorders), this drug must be stopped.     

RNA干扰技术抑制成骨细胞核激活因子受体配体基因对破骨细胞生成的影响

目的:利用RNA干扰技术抑制大鼠成骨细胞核激活因子受体配体(Ligand of receptor activator of NF-κB,RANKL)的表达,观察成骨细胞RANKL/骨保护素(osteoprotegerin,OPG)比值变化,探讨成骨细胞与破骨细胞生成的相关性。方法:实验于2006-05/10在四川大学华西医院移植免疫实验室(国家重点实验室)完成。①实验材料:体外化学合成4条RANKL序列特异性小干扰RNA(small interfering RNA,siRNA),用Lipofectin2000TM转染成骨细胞。②实验方法:采用荧光实时定量聚合酶链反应检测RANKL mRNA的表达,筛选出最有效的干扰序列。③实验分组:分为最有效的siRNA转染组、阴性对照组和空白对照组,每组设5个平行样本。采用免疫组织化学染色检测成骨细胞中RANKL、OPG蛋白的表达,观察RANKL/OPG比值变化。④实验评估:采用成骨细胞、破骨细胞共培养技术观察以上3组转染后的成骨细胞对破骨细胞生成的影响。结果:①4种siRNA敲除RANKL基因后mRNA的表达:4种siRNA转染成骨细胞后,相对空白对照组,siRNA4分子对RANKLmRNA的抑制作用最为明显,达到89%。siRNA1,siRNA3对RANKLmRNA的抑制作用大于50%,而siRNA2对RANKLmRNA的也有相当的抑制作用。②各组成骨细胞中RANKL和OPG蛋白水平:RANKL和OPG的阳性表达均显示为棕黄色颗粒,RANKL主要分布于成骨细胞的胞浆和胞膜,OPG主要分布于成骨细胞的胞浆。siRNA4转染组RANKL表达(平均积分光密度值)低于空白对照组(分别为3.05±2.17,11.31±1.26),差异有显著性意义(P<0.01);阴性对照组与空白对照相比,差异无显著性意义(P>0.05)。siRNA4转染组、阴性对照组OPG表达与空白对照组比较,差异均无显著性意义(P>0.05)siRNA4转染组RANKL/OPG比值低于空白对照组(分别为0.12±0.03,0.45±0.04),差异有显著性意义(P<0.01)。③转染的成骨细胞对破骨细胞生成的影响:各组共培养形成的破骨细胞形态与分离的成熟破骨细胞相似,为不规则形,胞浆红染,并有伪足形成。siRNA4转染组破骨细胞形成低于空白对照组、阴性对照组[分别为(12±2),(31±7),(28±5)个/孔],差异有显著性意义(P<0.01);阴性对照组与空白对照相比,差异无显著性意义(P>0.05)。结论:RNA干扰沉默RANKL表达可下调成骨细胞RANKL/OPG比值,抑制破骨细胞的生成。     

Satellite cell loss and impaired muscle regeneration in selenoprotein N deficiency

Selenoprotein N (SelN) deficiency causes a group of inherited neuromuscular disorders termed SEPN1-related myopathies (SEPN1-RM). Although the function of SelN remains unknown, recent data demonstrated that it is dispensable for mouse embryogenesis and suggested its involvement in the regulation of ryanodine receptors and/or cellular redox homeostasis. Here, we investigate the role of SelN in satellite cell (SC) function and muscle regeneration, using the Sepn1(-/-) mouse model. Following cardiotoxin-induced injury, SelN expression was strongly up-regulated in wild-type muscles and, for the first time, we detected its endogenous expression in a subset of mononucleated cells by immunohistochemistry. We show that SelN deficiency results in a reduced basal SC pool in adult skeletal muscles and in an imperfect muscle restoration following a single injury. A dramatic depletion of the SC pool was detected after the first round of degeneration and regeneration that totally prevented subsequent regeneration of Sepn1(-/-) muscles. We demonstrate that SelN deficiency affects SC dynamics on isolated single fibres and increases the proliferation of Sepn1(-/-) muscle precursors in vivo and in vitro. Most importantly, exhaustion of the SC population was specifically identified in muscle biopsies from patients with mutations in the SEPN1 gene. In conclusion, we describe for the first time a major physiological function of SelN in skeletal muscles, as a key regulator of SC function, which likely plays a central role in the pathophysiological mechanism leading to SEPN1-RM.