Long-term safety and efficacy of ambrisentan in Japanese adults with pulmonary arterial hypertension.

OBJECTIVE: To investigate the safety and efficacy of long-term administration of ambrisentan in Japanese adults with pulmonary arterial hypertension (PAH). RESEARCH DESIGN AND METHODS: In this open-label extension of a preceding multicenter dose-escalation study, 21 Japanese patients with PAH received treatment with 5 or 10 mg of ambrisentan once daily and were comprehensively evaluated every 12 weeks. The primary endpoint was the safety of long-term ambrisentan administration, as defined by the incidence and severity of adverse events. The secondary (efficacy) endpoints were change in exercise capacity (as indicated by 6-minute walk distance), World Health Organization functional class, Borg dyspnea index, plasma brain natriuretic peptide level, cardiopulmonary hemodynamics, and time to clinical worsening of PAH. CLINICAL TRIAL REGISTRATION: NCT00554619. RESULTS: The mean total duration of treatment (i.e., including the preceding dose-escalation study) was approximately 139 weeks. There were fewer adverse events related to ambrisentan in this study than in the preceding study, and we identified no new safety signals that might preclude the long-term use of ambrisentan among Japanese adults with PAH. Improvements observed in efficacy endpoints in the preceding study were maintained in the present study. LIMITATIONS: This study did not include a control group and lacked the statistical power to reach definite conclusions regarding the efficacy of ambrisentan. CONCLUSION: Our results suggest that long-term administration of ambrisentan is well tolerated and efficacious for Japanese adults with PAH.

Multidetector-row computed tomography-based clinical assessment of fondaparinux for treatment of acute pulmonary embolism and acute deep vein thrombosis in Japanese patients.

BACKGROUND: Unfractionated heparin (UFH) is the standard drug for the initial treatment of pulmonary embolism (PE) and deep vein thrombosis (DVT) in Japan, whereas fondaparinux is the standard drug in Europe and the United States. Here, we examine the efficacy and safety of fondaparinux in Japanese patients. METHODS AND RESULTS: In 2 randomized, open-label, multicenter studies, 80 Japanese patients with acute PE or DVT received either subcutaneous fondaparinux or intravenous UFH as a non-comparative reference, in a 3:1 ratio, for 5-10 days. Concomitant warfarin therapy was continued until Day 90. Multidetector-row computed tomography-based assessment showed that 57.9% and 45.9% of the patients with acute PE and acute proximal DVT had proximal DVT and PE as a complication, respectively. There was no recurrence of symptomatic venous thromboembolism. In the fondaparinux group, the respective improvement rates at the end of the initial treatment and follow-up periods were 71.4% and 86.8% for 42 patients with PE, and 57.8% and 83.3% for 46 patients with DVT; similar results were noted in the UFH group. One patient in the fondaparinux group experienced major bleeding during the initial treatment, but no such episode in the UFH group. CONCLUSIONS: Once-daily, subcutaneous fondaparinux is as effective and safe without monitoring as adjusted-dose intravenous UFH for the initial treatment of acute PE and DVT in Japanese patients.

Expression and characterization of the Streptomyces coelicolor serine/threonine protein kinase PkaD.

We identified and characterized the gene encoding a new eukaryotic-type protein kinase from Streptomyces coelicolor A3(2) M145. PkaD, consisting of 598 amino acid residues, contained the catalytic domain of eukaryotic protein kinases in the N-terminal region. A hydrophobicity plot indicated the presence of a putative transmembrane spanning sequence downstream of the catalytic domain, suggesting that PkaD is a transmembrane protein kinase. The recombinant PkaD was found to be phosphorylated at the threonine and tyrosine residues. In S. coelicolor A3(2), pkaD was transcribed as a monocistronic mRNA, and it was expressed constitutively throughout the life cycle. Disruption of chromosomal pkaD resulted in a significant loss of actinorhodin production. This result implies the involvement of pkaD in the regulation of secondary metabolism.

Sequences and evolutionary analyses of eukaryotic-type protein kinases from Streptomyces coelicolor A3(2).

Four eukaryotic-type protein serine/threonine kinases from Streptomyces coelicolor A3(2) were cloned and sequenced. To explore evolutionary relationships between these and other protein kinases, the distribution of protein serine/threonine kinase genes in prokaryotes was examined with the TFASTA program. Genes of this type were detected in only a few species of prokaryotes and their distribution was uneven; Streptomyces, Mycobacterium, Synechocystis and Myxococcus each contained more than three such genes. Homology analyses by GAP and Rdf2 programs suggested that some kinases from one species were closely related, whilst others were only remotely related. This was confirmed by examining phylogenetic trees constructed by the neighbour-joining and other methods. For each species, analysis of the coding regions indicated that the G+C content of protein kinase genes was similar to that of other genes. Considered with the fact that in phylogenetic trees the amino acid sequences of STPK from Aquifex aeolicus and some other eukaryotic-type protein kinases in prokaryotes form a cluster with protein kinases from eukaryotes, this suggests that the eukaryotic-type protein kinases were present originally in both prokaryotes and eukaryotes, but that most of these genes have been lost during the evolutionary process in prokaryotes because they are not needed. This conclusion is supported by the observation that the prokaryotes retaining several of these kinases undergo complicated morphological and/or biochemical differentiation.