Mechanisms of plasmid-mediated antibiotic resistances in Vibrio parahaemolyticus

The mechanisms of drug resistance of clinical isolate, Vibrio (V.) parahaemolyticus ST550, resistant to chloramphenicol (CP), aminoglycoside antibiotics (AGs) and beta-lactam antibiotics were investigated. The mechanisms of resistance to CP, AGs and beta-lactam antibiotics were dependent on chloramphenicol acetyltransferase (CAT), aminoglycoside-3"-adenylyltransferase AAD(3") and aminoglycoside-3'-phosphotransferase APH(3') and TEM type penicillinase, respectively.     

Discovery of novel series of benzoic acid derivatives containing biphenyl ether moiety as potent and selective human beta(3)-adrenergic receptor agonists: Part IV

Identification and SAR study of novel series of beta(3)-AR agonists with benzoic acid are described. Conversion of ether linkage position of phenoxybenzoic acid derivative 2b led to compound 7b with moderate beta(3)-AR activity. Further modification in right, center and left parts of compound 7b was investigated to improve the beta(3)-AR potency and selectivity. Compounds 7g and 7k, with the bulky aliphatic-substituted group at 2-position of benzoic acid moiety, were identified as potent and selective beta(3)-AR agonists. In addition, in vivo efficacy of compounds 7g and 7k was exhibited on dog OAB model.     

The antibacterial activity of plaunotol against Staphylococcus aureus isolated from the skin of patients with atopic dermatitis.

Plaunotol was tested for possible antibacterial activity against twenty strains of methicillin-resistant Staphylococcus aureus (MRSA) and fourteen strains of methicillin-sensitive S. aureus (MSSA) which had been isolated from the skin of patients with atopic dermatitis under growth-promoting conditions. Plaunotol was effective against all strains tested. The dose of plaunotol for 50% inhibition of growth (ID50) ranged from 2.5 to 16 micrograms/ml for strains of MRSA and from 2.5 to 7.0 micrograms/ml for those of MSSA. These results suggest that plaunotol may be useful in the prevention of infection by MRSA and in skin care for patients with atopic dermatitis.     

Cognitive and socio-emotional deficits in platelet-derived growth factor receptor-β gene knockout mice

Platelet-derived growth factor (PDGF) is a potent mitogen. Extensive in vivo studies of PDGF and its receptor (PDGFR) genes have reported that PDGF plays an important role in embryogenesis and development of the central nervous system (CNS). Furthermore, PDGF and the β subunit of the PDGF receptor (PDGFR-β) have been reported to be associated with schizophrenia and autism. However, no study has reported on the effects of PDGF deletion on mice behavior. Here we generated novel mutant mice (PDGFR-β KO) in which PDGFR-β was conditionally deleted in CNS neurons using the Cre/loxP system. Mice without the Cre transgene but with floxed PDGFR-β were used as controls. Both groups of mice reached adulthood without any apparent anatomical defects. These mice were further examined by conducting several behavioral tests for spatial memory, social interaction, conditioning, prepulse inhibition, and forced swimming. The test results indicated that the PDGFR-β KO mice show deficits in all of these areas. Furthermore, an immunohistochemical study of the PDGFR-β KO mice brain indicated that the number of parvalbumin (calcium-binding protein)-positive (i.e., putatively γ-aminobutyric acid-ergic) neurons was low in the amygdala, hippocampus, and medial prefrontal cortex. Neurophysiological studies indicated that sensory-evoked gamma oscillation was low in the PDGFR-β KO mice, consistent with the observed reduction in the number of parvalbumin-positive neurons. These results suggest that PDGFR-β plays an important role in cognitive and socioemotional functions, and that deficits in this receptor may partly underlie the cognitive and socioemotional deficits observed in schizophrenic and autistic patients.     

Habitat preferences of four chironomid species associated with aquatic macrophytes in an irrigation reservoir

Habitat preferences of four chironomid species associated with aquatic macrophytes were studied during the vegetation season from April to October at an irrigation reservoir located in Nagoya, Japan.The two smaller sized species,Corynoneura cuspis Tokunaga andPentapedilum tigrinum Hashimoto, were found to be abundant in two floating-leaved plants,Nymphoides indica O. Kuntze andTrapa japonica Flerov. Phytophages,C. cuspis larvae were observed freely moving on the surfaces of leaves and stems within both of these floating-leaved plant communities. Although found within both plant communities,P. tigrinum larvae, as facultative leaf miners, were more concentrated on the surfaces and within the leaves ofN. indica, which have a thin epidermis and thick mesophyll layer.The two larger sized species,Glyptotendipes viridis (Macquart) andPentapedilum sordens (van der Wulp), were found to be living principally within the stems ofN. indica and the petioles ofT. japonica. These parts of the plants, with thin epidermis and many lacunae in the parenchyma, are favorable for miners.     

Isolation and structure of a new integron that includes a streptomycin resistance gene from the R plasmid of Pseudomonas aeruginosa

Abstract A new integron, located on the R plasmid of Pseudomonas aeruginosa , was isolated in Japan. This integron was made up of two conserved segments (5'- and 3'-conserved segments) and a single streptomycin resistance gene as a gene cassette. The structure of this integron resembles that of integron InC, the existence of which was postulated by Bissonnette and Roy (J. Bacteriol. 174, 1248–1257, 1992).     

Unnatural enantiomer of chaetocin shows strong apoptosis-inducing activity through caspase-8/caspase-3 activation

Chaetocin, a natural product isolated from Chaetomium species fungi, was reported to have various biological activities, including antitumor and antifungal activities. Recently, we reported the first total synthesis of chaetocin and its derivatives. Here, we examined the cell-death-inducing activity of these compounds in human leukemia HL-60 cells. The unnatural enantiomer of chaetocin (ent-chaetocin) was more potent than chaetocin, and was found to induce apoptosis through the caspase-8/caspase-3 activation pathway.     

Variations in the gene for vacuolating toxin, vacA, in Japanese isolates of Helicobacter pylori.

Each of 284 strains of Helicobacter pylori which had been isolated in Japan was shown, by use of the polymerase chain reaction (PCR), to be positive for the vacA genes. The amplified vacA genes generated by PCR were classified into six classes (five for the clinical isolates, and one which corresponded to the standard strains). Endoscopic analysis revealed that cases of gastritis were most likely to be associated with class D, while none were associated with class A. The patterns of products of PCR obtained from the Japanese isolates were compared with theoretical patterns derived from sequences of vacA which had been reported previously. The nucleotide sequences of amplified fragments of vacA from representative strains in each class were determined and compared with those of previously reported vacA genes.     

Survival Analysis of Patients with Interval Cancer Undergoing Gastric Cancer Screening by Endoscopy

AimsInterval cancer is a key factor that influences the effectiveness of a cancer screening program. To evaluate the impact of interval cancer on the effectiveness of endoscopic screening, the survival rates of patients with interval cancer were analyzed.MethodsWe performed gastric cancer-specific and all-causes survival analyses of patients with screen-detected cancer and patients with interval cancer in the endoscopic screening group and radiographic screening group using the Kaplan-Meier method. Since the screening interval was 1 year, interval cancer was defined as gastric cancer detected within 1 year after a negative result. A Cox proportional hazards model was used to investigate the risk factors associated with gastric cancer-specific and all-causes death.ResultsA total of 1,493 gastric cancer patients (endoscopic screening group: n = 347; radiographic screening group: n = 166; outpatient group: n = 980) were identified from the Tottori Cancer Registry from 2001 to 2008. The gastric cancer-specific survival rates were higher in the endoscopic screening group than in the radiographic screening group and the outpatients group. In the endoscopic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer and the patients with interval cancer were nearly equal (P = 0.869). In the radiographic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer was higher than that of the patients with interval cancer (P = 0.009). For gastric cancer-specific death, the hazard ratio of interval cancer in the endoscopic screening group was 0.216 for gastric cancer death (95%CI: 0.054-0.868) compared with the outpatient group.ConclusionThe survival rate and the risk of gastric cancer death among the patients with screen-detected cancer and patients with interval cancer were not significantly different in the annual endoscopic screening. These results suggest the potential of endoscopic screening in reducing mortality from gastric cancer.