Rapid detection of blaIMP-6 by amplification refractory mutation system

Klebsiella pneumoniae resistant to almost all ß-lactams except imipenem designated as ISMRK (imipenem-susceptible meropenem-resistant Klebsiella) is emerging in Japan. All ISMRK carries bla_IMP-6 which differs from bla_IMP-1 by only a single nucleotide at position 640. We devised a rapid detection system of bla_IMP-6 by using ARMS PCR.     

Regulation by mitochondrial superoxide and NADPH oxidase of cellular formation of nitrated cyclic GMP: potential implications for ROS signalling

8-Nitro-cGMP (8-nitroguanosine 3',5'-cyclic monophosphate) is a nitrated derivative of cGMP, which can function as a unique electrophilic second messenger involved in regulation of an antioxidant adaptive response in cells. In the present study, we investigated chemical and biochemical regulatory mechanisms involved in 8-nitro-cGMP formation, with particular focus on the roles of ROS (reactive oxygen species). Chemical analyses demonstrated that peroxynitrite-dependent oxidation and myeloperoxidase-dependent oxidation of nitrite in the presence of H2O2 were two major pathways for guanine nucleotide nitration. Among the guanine nucleotides examined, GTP was the most sensitive to peroxynitrite-mediated nitration. Immunocytochemical and tandem mass spectrometric analyses revealed that formation of 8-nitro-cGMP in rat C6 glioma cells stimulated with lipopolysaccharide plus pro-inflammatory cytokines depended on production of both superoxide and H2O2. Using the mitochondria-targeted chemical probe MitoSOX Red, we found that mitochondria-derived superoxide can act as a direct determinant of 8-nitro-cGMP formation. Furthermore, we demonstrated that Nox2 (NADPH oxidase 2)-generated H2O2 regulated mitochondria-derived superoxide production, which suggests the importance of cross-talk between Nox2-dependent H2O2 production and mitochondrial superoxide production. The results of the present study suggest that 8-nitro-cGMP can serve as a unique second messenger that may be implicated in regulating ROS signalling in the presence of NO.     

Temporal changes of genetic population structure and diversity in the endangered Blakiston's fish owl (Bubo blakistoni) on Hokkaido Island, Japan, revealed by microsatellite analysis

The Blakiston's fish owl (Bubo blakistoni) population on Hokkaido Island, Japan, decreased to less than one hundred individuals over the last century due to habitat disruption by human activity. Although the ongoing conservation management has slightly restored the population, it remains endangered. In order to assess the genetic variation and population structure of the Blakiston's fish owl in Hokkaido, we genotyped eight microsatellite loci on 120 individuals sampled over the past three decades. The genotype data set showed low levels of genetic variation and gene flow among the geographically isolated five subpopulations. Comparative analysis of past and current populations indicated that some alleles shared by past individuals had been lost, and that genetic variation had declined over the last three decades. The result suggests that the genetic decline may have resulted from inbreeding and/or genetic drift due to bottlenecks in the Hokkaido population. The present study provides invaluable genetic information for the conservation and management of the endangered Blakiston's fish owl in Hokkaido.     

Potential association of Helicobacter cinaedi with atrial arrhythmias and atherosclerosis

Helicobacter cinaedi has been increasingly recognized as an emerging pathogen. Reports of recurrent bacteremia and isolation of H. cinaedi organisms from a patient with myopericarditis led us to postulate that H. cinaedi is associated with chronic inflammatory cardiovascular diseases such as atrial arrhythmias and atherosclerosis. To assess any association of H. cinaedi with atrial arrhythmias, a retrospective case-control study of patients attending Kumamoto University Hospital from 2005 to 2009 was performed. The arrhythmia status of these patients was determined from their electrocardiography and electrophysiological studies. Multiple logistic regression analysis was used to identify independent risk factors. In a comparison of case patients (n= 132) with control subjects (n= 137), H. cinaedi seropositivity was identified as an independent risk factor for atrial arrhythmia (odds ratio, 5.13; 95% confidence interval, 3.0-8.7; P < 0.001). There were no significant differences, however, between these two groups with respect to anti-H. pylori IgG concentrations, anti-Chlamydophila pneumoniae IgG concentrations, and other studied variables. IgG concentrations against H. cinaedi and H. pylori were inversely correlated, which suggests cross-immunity between these two bacteria. Also, to explore any association of H. cinaedi with atherosclerosis, immunohistochemical analysis of atherosclerotic aortic tissues collected post mortem from nine patients was performed. Immunohistochemistry of atherosclerotic aortic tissues from all nine patients detected H. cinaedi antigens inside CD68(+) macrophages. These findings provide the first evidence, to our knowledge, of a possible association of H. cinaedi with atrial arrhythmias and atherosclerosis.     

The Small Interfering RNA Pathway Is Not Essential for Wolbachia-Mediated Antiviral Protection in Drosophila melanogaster

Wolbachia pipientis delays RNA virus-induced mortality in Drosophila spp. We investigated whether Wolbachia-mediated protection was dependent on the small interfering RNA (siRNA) pathway, a key antiviral defense. Compared to Wolbachia-free flies, virus-induced mortality was delayed in Wolbachia-infected flies with loss-of-function of siRNA pathway components, indicating that Wolbachia-mediated protection functions in the absence of the canonical siRNA pathway.     

Cytotoxic prodigiosin family pigments from Pseudoalteromonas sp. 1020R isolated from the Pacific coast of Japan

Pseudoalteromonas sp. 1020R, isolated from the Pacific coast of Japan, produces prodigiosin family pigments. Structural analysis indicated that these are prodigiosin (2-methyl-3-pentyl-prodiginine) and three other prodigiosin congeners which differ only in the lengths of the alkyl side chains. These compounds exhibited different extents of cytotoxicity against U937 leukemia cells, and cell death was accompanied by typical features of apoptosis.     

Whole-genome sequencing and analysis of the Malaysian cynomolgus macaque (Macaca fascicularis) genome

ABSTRACT: BACKGROUND: The genetic background of the cynomolgus macaque (Macaca fascicularis) is made complex by the high genetic diversity, population structure, and gene introgression from the closely related rhesus macaque (Macaca mulatta). Herein we report the whole-genome sequence of a Malaysian cynomolgus macaque male with more than 40-fold coverage, which was determined using a resequencing method based on the Indian rhesus macaque genome. RESULTS: We identified approximately 9.7 million single nucleotide variants (SNVs) between the Malaysian cynomolgus and the Indian rhesus macaque genomes. Compared with humans, a smaller nonsynonymous/synonymous SNV ratio in the cynomolgus macaque suggests more effective removal of slightly deleterious mutations. Comparison of two cynomolgus (Malaysian and Vietnamese) and two rhesus (Indian and Chinese) macaque genomes, including previously published macaque genomes, suggests that Indochinese cynomolgus macaques have been more affected by gene introgression from rhesus macaques. We further identified 60 nonsynonymous SNVs that completely differentiated the cynomolgus and rhesus macaque genomes, and that could be important candidate variants for determining species-specific responses to drugs and pathogens. The demographic inference using the genome sequence data revealed that Malaysian cynomolgus macaques have experienced at least three population bottlenecks. CONCLUSIONS: This list of whole-genome SNVs will be useful for many future applications, such as an array-based genotyping system for macaque individuals. High-quality whole-genome sequencing of the cynomolgus macaque genome may aid studies on finding genetic differences that are responsible for phenotypic diversity in macaques and may help control genetic backgrounds among individuals.     

The role of heavy-metal ATPases,HMAs, in zinc and cadmium transport in rice

The P_1B-type heavy metal ATPases (HMAs) are diverse in terms of tissue distribution, subcellular localization, and metal specificity. Functional studies of HMAs have shown that these transporters can be divided into two subgroups based on their metal-substrate specificity: a copper (Cu)/silver (Ag) group and a zinc (Zn)/cobalt (Co)/cadmium (Cd)/lead (Pb) group. Studies on Arabidopsis thaliana and metal hyperaccumulator plants indicate that HMAs play an important role in the translocation or detoxification of Zn and Cd in plants. Rice possesses nine HMA genes, of which OsHMA1–OsHMA3 belong to the Zn/Co/Cd/Pb subgroup. OsHMA2 plays an important role in root-to-shoot translocation of Zn and Cd, and participates in Zn and Cd transport to developing seeds in rice. OsHMA3 transports Cd and plays a role in the sequestration of Cd into vacuoles in root cells. Modification of the expression of these genes might be an effective approach for reducing the Cd concentration in rice grains.     

Effects of a novel Y5 antagonist in obese mice: combination with food restriction or sibutramine

Objective: To further address the function of the Y5 receptor in energy homeostasis, we investigated the effects of a novel spironolactone Y5 antagonist in diet-induced obese (DIO) mice. Methods and Procedures: Male C57BL/6 or Npy5r^−/− mice were adapted to high-fat (HF) diet for 6–10 months and were submitted to three experimental treatments. First, the Y5 antagonist at a dose of 10 or 30 mg/kg was administered for 1 month to DIO C57BL/6 or Npy5r^−/− mice. Second, the Y5 antagonist at 30 mg/kg was administered for 1.5 months to DIO C57BL/6 mice, and insulin sensitivity was evaluated using an insulin tolerance test. After a recovery period, nuclear magnetic resonance measurement was performed to evaluate body composition. Third, DIO mice were treated with the Y5 antagonist alone, or in combination with 10% food restriction, or with another anorectic agent, sibutramine at 10 mg/kg, for 1.5 months. Plasma glucose, insulin, and leptin levels, and adipose tissue weights were quantified. Results: The spironolactone Y5 antagonist significantly reduced body weight in C57BL DIO mice, but not in Npy5r^−/− DIO mice. The Y5 antagonist produced a fat-selective loss of body weight, and ameliorated obesity-associated insulin resistance in DIO mice. In addition, the Y5 antagonist combined with either food restriction or sibutramine tended to produce greater body weight loss, as compared with single treatment. Discussion: These findings demonstrate that the Y5 receptor is an important mediator of energy homeostasis in rodents.