ITPA Polymorphisms Are Associated with Hematological Side Effects during Antiviral Therapy for Chronic HCV Infection

Background/ObjectiveGenetic polymorphisms in the inosine triphosphatase (ITPA) gene have been associated with the protection from early ribavirin(RBV)-induced hemolytic anemia among patients with chronic hepatitis C virus (HCV) infection. The aim of the present study was to investigate the association between the functional ITPA variants and hematological side effects during antiviral therapy with pegylated interferon (PegIFN) and RBV.ResultsIn total, 213 patients were included. The predicted ITPase activity was normal among 152 (71%) patients; 61 (29%) patients had ITPase deficiency. By multivariable linear regression, RBV dose in mg per kilogram (Beta 0.09, 95%CI 0.04–0.13, p<0.001) and normal ITPase activity (Beta 0.89, 95%CI 0.64–1.14, p<0.001) were associated with more Hb decline at week 4 of treatment. Patients with normal ITPase activity underwent more dose adjustments of RBV than patients with ITPase deficiency (19(13%) vs 1(2%),p = 0.014) and received erythropoietin more frequently (12 (8%) vs 0 (0%),p = 0.024).ConclusionGenetic variants in the ITPA gene protected against RBV treatment-induced anemia among Caucasian patients with chronic HCV infection. Patients with normal ITPase activity underwent more dose reductions of RBV and received erythropoietin more frequently.     

Genetics of shoulder girdle formation: roles of Tbx15 and aristaless-like genes

The diverse cellular contributions to the skeletal elements of the vertebrate shoulder and pelvic girdles during embryonic development complicate the study of their patterning. Research in avian embryos has recently clarified part of the embryological basis of shoulder formation. Although dermomyotomal cells provide the progenitors of the scapular blade, local signals appear to have an essential guiding role in this process. These signals differ from those that are known to pattern the more distal appendicular skeleton. We have studied the impact of Tbx15, Gli3, Alx4 and related genes on formation of the skeletal elements of the mouse shoulder and pelvic girdles. We observed severe reduction of the scapula in double and triple mutants of these genes. Analyses of a range of complex genotypes revealed aspects of their genetic relationship, as well as functions that had been previously masked due to functional redundancy. Tbx15 and Gli3 appear to have synergistic functions in formation of the scapular blade. Scapular truncation in triple mutants of Tbx15, Alx4 and Cart1 indicates essential functions for Alx4 and Cart1 in the anterior part of the scapula, as opposed to Gli3 function being linked to the posterior part. Especially in Alx4/Cart1 mutants, the expression of markers such as Pax1, Pax3 and Scleraxis is altered prior to stages when anatomical aberrations are visible in the shoulder region. This suggests a disorganization of the proximal limb bud and adjacent flank mesoderm, and is likely to reflect the disruption of a mechanism providing positional cues to guide progenitor cells to their destination in the pectoral girdle.     

Overexpression of the 78-kDa glucose-regulated protein/immunoglobulin-binding protein (GRP78/BiP) inhibits tissue factor procoagulant activity

Previous studies have demonstrated that overexpression of GRP78/BiP, an endoplasmic reticulum (ER)-resident molecular chaperone, in mammalian cells inhibits the secretion of specific coagulation factors. However, the effects of GRP78/BiP on activation of the coagulation cascade leading to thrombin generation are not known. In this study, we examined whether GRP78/BiP overexpression mediates cell surface thrombin generation in a human bladder cancer cell line T24/83 having prothrombotic characteristics. We report here that cells overexpressing GRP78/BiP exhibited significant decreases in cell surface-mediated thrombin generation, prothrombin consumption and the formation of thrombin-inhibitor complexes, compared with wild-type or vector-transfected cells. This effect was attributed to the ability of GRP78/BiP to inhibit cell surface tissue factor (TF) procoagulant activity (PCA) because conversion of factor X to Xa and factor VII to VIIa were significantly lower on the surface of GRP78/BiP-overexpressing cells. The additional findings that (i) cell surface factor Xa generation was inhibited in the absence of factor VIIa and (ii) TF PCA was inhibited by a neutralizing antibody to human TF suggests that thrombin generation is mediated exclusively by TF. GRP78/BiP overexpression did not decrease cell surface levels of TF, suggesting that the inhibition in TF PCA does not result from retention of TF in the ER by GRP78/BiP. The additional observations that both adenovirus-mediated and stable GRP78/BiP overexpression attenuated TF PCA stimulated by ionomycin or hydrogen peroxide suggest that GRP78/BiP indirectly alters TF PCA through a mechanism involving cellular Ca(2+) and/or oxidative stress. Similar results were also observed in human aortic smooth muscle cells transfected with the GRP78/BiP adenovirus. Taken together, these findings demonstrate that overexpression of GRP78/BiP decreases thrombin generation by inhibiting cell surface TF PCA, thereby suppressing the prothrombotic potential of cells.     

Cancer genetics and its "different faces of autonomy"

In this article we discuss the development of a practice of screening, preventive treatment, and presymptomatic testing for individuals at risk of Familial Adenomatous Polyposis (FAP), a specific hereditary predisposition for colon cancer. We describe this development as a process of co-evolution, showing how this practice has been gradually taking shape in a new network of actors, routines, rules, institutions and technologies. We further argue that, looking at the emergence and transformation of this practice, we can distinguish two different regimes: a regime of prevention and a regime of self-determination. In each of these regimes the autonomy of patients and individuals at risk is shaped in a different way, that is, through a different complex of ideals, procedures, institutions, technologies, and routines. In our view, the interference between these two regimes is an important characteristic of the emergent new genetics and is reflected in the growing debate about non-directivity in genetic counselling. However, as our argument implies, when facing the challenges of the new genetics we should not restrict the debate to the quality and ethics of counselling, but extend our view to the whole complex of elements and activities which shapes individual autonomy in the context of different regimes.     

Tuning hydrophobicity of highly cationic tetradecameric Gramicidin S analogues using adamantane amino acids

Ring extended Gramicidin S analogues containing adamantane amino acids and six cationic residues were designed and evaluated. Systematic replacement of the hydrophobic residues with adamantane amino acids resulted in a small set of compounds with varying amphipathic character. It was found that the amphipathicity of these compounds is correlated to their biological activity. Several bacterial strains including MRSA strains were shown to be killed by the novel peptides. The most potent antibacterial peptides are tetradecameric GS analogues containing six positives charges and two adamantane moieties.     

Extensive sharing of MHC class II alleles between rhesus and cynomolgus macaques

In contrast to rhesus monkeys, substantial knowledge on cynomolgus monkey major histocompatibility complex (MHC) class II haplotypes is lacking. Therefore, 17 animals, including one pedigreed family, were thoroughly characterized for polymorphic Mhc class II region genes as well as their mitochondrial DNA (mtDNA) sequences. Different cynomolgus macaque populations appear to exhibit unique mtDNA profiles reflecting their geographic origin. Within the present panel, 10 Mafa-DPB1, 14 Mafa-DQA1, 12 Mafa-DQB1, and 35 Mafa-DRB exon 2 sequences were identified. All of these alleles cluster into lineages that were previously described for rhesus macaques. Moreover, about half of the Mafa-DPB1, Mafa-DQA1, and Mafa-DQB1 alleles and one third of the Mafa-DRB exon 2 sequences are identical to rhesus macaque orthologues. Such a high level of Mhc class II allele sharing has not been reported for primate species. Pedigree analysis allowed the characterization of nine distinct Mafa class II haplotypes, and seven additional ones could be deduced. Two of these haplotypes harbor a duplication of the Mafa-DQB1 locus. Despite extensive allele sharing, rhesus and cynomolgus monkeys do not appear to possess identical Mhc class II haplotypes, thus illustrating that new haplotypes were generated after speciation by recombination-like processes.