Update on the interaction of rifampin and warfarin

A 79-year-old man with a history of deep vein thrombosis and pulmonary embolism received anticoagulation therapy with warfarin 5 mg daily for 8 months. He was diagnosed with osteomyelitis and underwent partial metatarsal resection of his right foot. After surgery, antibiotics were initiated, including ertapenem sodium 1 g intravenously every 24 hours, vancomycin 1400 mg intravenously every 24 hours, and rifampin 300 mg by mouth twice daily. Achieving a therapeutic level of anticoagulation was difficult despite escalating doses of warfarin, because of the interaction with rifampin. A 5- to 6-fold increase in warfarin dose was prescribed to reach therapeutic international normalized ratios (INRs), but even these increases were insufficient to maintain his INR in the therapeutic range. After rifampin was discontinued, warfarin doses were gradually reduced over the next 2 months. When concurrent warfarin-rifampin therapy is necessary, vigilant monitoring is imperative and significant increases in warfarin doses are likely.     

Promoter polymorphism rs3087456 in the MHC class II transactivator gene is not associated with susceptibility for selected autoimmune diseases in German patient groups

We analysed whether the single nucleotide polymorphism (SNP) rs3087456 in the promoter of the MHC class II transactivator (MHC2TA) gene is associated with manifestation of rheumatoid arthritis, multiple sclerosis, narcolepsy and Wegener granulomatosis. The recently reported association in a northern population of the MHC2TA variation with these autoimmune diseases is not evident in the German population.     

Association screen for atopic dermatitis candidate gene regions using microsatellite markers in pooled DNA samples

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting up to 16% of children in developed countries. A complex genetic background for AD has been suggested, with genetic as well as environmental factors influencing disease susceptibility. Among other factors, dysregulation in both the innate and the adaptive immune system has been proposed to play a role in AD pathophysiology. We present here an extended association screen for AD using microsatellite markers in 154 genes related to innate and adaptive immunity in pooled DNA samples from 150 German children with AD and 100 controls. After Bonferroni correction, no marker revealed a significant association with AD. Yet, markers representing the nuclear factor kappa B (NFKB)1 and chemokine receptor (CCR)4 genes showed differences in allelic distributions between cases and controls for both pooled DNA analysis and individual genotyping and were thus further investigated. Evaluation of additional single nucleotide polymorphisms (SNP) in the NFKB1 and CCR4 genes revealed no association of individual SNPs with AD. In contrast, haplotype analyses showed a significantly different haplotype distribution between patients and controls for CCR4 (P < 0.001). Furthermore, when SNP-SNP interaction effects were analysed for these two genes, we found significant evidence for epistatic interactions between SNPs within each of the two genes but no evidence for a gene-gene interaction, suggesting that variation in or near both the CCR4 and the NFKB1 genes might individually contribute to AD pathogenesis.     

No association between polymorphisms in the BDNF gene and age at onset in Huntington disease

Background

Recent evidence suggests that brain-derived neurotrophic factor (BDNF) is an attractive candidate for modifying age at onset (AO) in Huntington disease (HD). In particular, the functional Val66Met polymorphism appeared to exert a significant effect. Here we evaluate BDNF variability with respect to AO of HD using markers that represent the entire locus.

Methods

Five selected tagging polymorphisms were genotyped across a 65 kb region comprising the BDNF gene in a well established cohort of 250 unrelated German HD patients.

Results

Addition of BDNF genotype variations or one of the marker haplotypes to the effect of CAG repeat lengths did not affect the variance of the AO.

Conclusion

We were unable to verify a recently reported association between the functional Val66Met polymorphism in the BDNF gene and AO in HD. From our findings, we conclude that neither sequence variations in nor near the gene contribute significantly to the variance of AO.     

Three novel mutations in the ACTA2 gene in German patients with thoracic aortic aneurysms and dissections

Mutations in the gene encoding smooth muscle cell alpha actin (ACTA2) have recently been shown to cause familial thoracic aortic aneurysms leading to type A dissections (TAAD) and predispose to premature stroke and coronary artery disease. In order to further explore the role of ACTA2 variations in the pathogenesis of TAAD, we sequenced the coding regions of this gene in 40 unrelated German patients with TAAD (with (n=21) or without (n=19) clinical features suggestive of Marfan syndrome). All patients had previously tested negative for mutations in the FBN1 and TGFBR2 genes. We identified three novel ACTA2 mutations and mapped them on a three-dimensional model of actin. Two mutations affect residues within (M49V) or adjacent to (R39C), the DNAse-I-binding loop within subdomain 2 of alpha actin. They were observed in families with recurrent aortic aneurysm (R39C) or aortic dissection (M49V). The third mutation causes an exchange in the vicinity of the ATP-binding site (G304R) in a patient thought to have isolated TAAD. None of the affected individuals had clinical features typical for Marfan syndrome, and no case of premature stroke or coronary artery disease was reported from the affected families. In conclusion, we underscore the role of ACTA2 mutations in nonsyndromic TAAD and suggest that ACTA2 should be included in the genes routinely investigated for syndromic and nonsyndromic TAAD. Detailed clinical investigations of additional families are warranted to further explore the full range of phenotypic signs associated with the three novel mutations described here.     

Severe Guillain-Barré syndrome associated with chromosome 17p11.2-12 duplication

We report a patient with Guillain-Barré syndrome (GBS), characterized by severe tetraparesis, bulbar syndrome, and ophthalmoparesis. The nadir was reached within 1 day, followed by respiratory insufficiency requiring mechanical ventilation. Molecular analysis revealed a duplication at chromosome 17p11.2-12, which is a known genetic cause of Charcot-Marie-Tooth disease type 1A (CMT1A). We suggest that this genotype may comprise a previously unrecognized genetic risk factor for GBS.     

小腿带腓肠神经远端筋膜蒂皮瓣移植的应用进展

目的:综合分析小腿、踝、足部复合伤后组织缺损与筋膜皮瓣移植的修复关系以及小腿带腓肠神经远端筋膜蒂皮瓣移植的解剖学基础与临床应用进展。资料来源:应用计算机检索Medline1990-01/2006-10有关小腿带腓肠神经远端筋膜蒂皮瓣移植的文章,检索词“sural nerve,fascia,flap,leg,lesser saphena”,并限定文章语言种类为English。同时计算机检索CNKI数据库1996-01/2006-10有关小腿带腓肠神经远端筋膜蒂皮瓣移植的文章,检索词“腓肠神经,皮瓣,筋膜,小隐静脉”,并对检索词进行分别组合,限定文章语言种类为中文。资料选择:对检索到的小腿带腓肠神经远端筋膜蒂皮瓣移植方面的相关信息进行整理,阅读2005,2006年度专业核心期刊的相关文章,在CNKI阅读查询到的引用2次以上的文献,选取针对性强的文章。资料提炼:有关小腿带腓肠神经远端筋膜蒂皮瓣移植的文献,有解剖学研究、病例报道、解剖与临床结合论著及综述等,相似的同一研究较多,国内研究、运用较国外丰富,其中有30篇纳入研究范畴。资料综合:小腿带腓肠神经远端蒂筋膜皮瓣具有以下优点:①蒂部具有穿支动脉,同时携带位于深筋膜层的皮神经及浅静脉,皮瓣移植难度较小,修复创面满意,不损失肢体的知名主干血管。②蒂部成形灵活,属于生理性皮瓣,成活可靠。③可重建感觉,以同样血供为基础的可形成复合瓣。小腿带腓肠神经远端筋膜蒂皮瓣是解决膝以下,足跖骨头以上皮肤组织缺损的简单、安全、效果良好的方法。结论:小腿带腓肠神经远端筋膜蒂皮瓣移植已成为创伤修复日渐青睐的手术方式,但在适应症、皮瓣血运基础、对小隐静脉处理、皮瓣质量(大小、外观、感觉)、术后护理等方面有待达成共识,使之成为修复创面的常用手段。     

人参皂甙Rb_1和Rg_1对小鼠中枢神经递质受体和脑内蛋白质合成的影响

应用放射配基结合法测定了人参皂甙Rb_1和Rg_1对α_1,α_2,β肾上腺素能受体、M胆碱能受体、5-羟色胺、多巴胺及GABA等七种受体的作用。结果均不能证明它们对这七种受体有亲和力。但给动物ip药物连续5天,Rb_1和Rg_1均能使中枢M胆碱受体密度显著增高。Rb_1及Rg_1还能显著增加脑内蛋白质的含量。上述实验结果对解释人参的中枢作用提供了重要证据。     

柯萨奇-腺病毒受体在肾癌组织中的表达及意义

目的:研究柯萨奇-腺病毒受体(CAR)在肾癌组织中的表达及意义.方法:应用免疫组化SP法检测12例癌旁正常肾组织和48例肾细胞癌组织中CAR的表达.结果:12例正常肾组织全部表达CAR,48例肾细胞癌组织中31例无CAR表达.不同分级CAR表达率分别为Ⅰ级54.5%(12/22)、Ⅱ级23.5%(4/17)、Ⅲ级11.1%(1/9);不同分期CAR表达率分别为Ⅰ期57.9%(11/19)、Ⅱ期30.8%(4/13)、Ⅲ期18.2%(2/11)、Ⅳ期0(0/5).结论:在多数肾细胞癌组织中CAR基因表达丧失;CAR表达变化与肾癌的分级、分期相关,可以作为肾癌分化、转移的重要生物学指标.     

The formation and function of the neutrophil phagosome

Neutrophils are the most abundant circulating leukocyte and are crucial to the initial innate immune response to infection. One of their key pathogen-eliminating mechanisms is phagocytosis, the process of particle engulfment into a vacuole-like structure called the phagosome. The antimicrobial activity of the phagocytic process results from a collaboration of multiple systems and mechanisms within this organelle, where a complex interplay of ion fluxes, pH, reactive oxygen species, and antimicrobial proteins creates a dynamic antimicrobial environment. This complexity, combined with the difficulties of studying neutrophils ex vivo, has led to gaps in our knowledge of how the neutrophil phagosome optimizes pathogen killing. In particular, controversy has arisen regarding the relative contribution and integration of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived antimicrobial agents and granule-delivered antimicrobial proteins. Clinical syndromes arising from dysfunction in these systems in humans allow useful insight into these mechanisms, but their redundancy and synergy add to the complexity. In this article, we review the current knowledge regarding the formation and function of the neutrophil phagosome, examine new insights into the phagosomal environment that have been permitted by technological advances in recent years, and discuss aspects of the phagocytic process that are still under debate.