Decontamination of mycoplasma-contaminated Orientia tsutsugamushi strains by repeating passages through cell cultures with antibiotics

Background: Mycoplasmas-contamination of Orientia tsutsugamushi, one of the obligated intracellular bacteria, is a very serious problem in in vitro studies using cell cultures because mycoplasmas have significant influence on the results of scientific studies. Only a recommended decontamination method is to passage the contaminated O. tsutsugamushi strains through mice to eliminate only mycoplasmas under influence of their immunity. However, this method sometimes does not work especially for low virulent strains of O. tsutsugamushi which are difficult to propagate in mice. In this study, we tried to eliminate mycoplasmas contaminants from both high virulent and low virulent strains of the contaminated O. tsutsugamushi by repeating passage through cell cultures with antibiotics in vitro. Results: We cultured a contaminated, high virulent strain of O. tsutsugamushi using a mouse lung fibroblasts cell line, L-929 cell in the culture medium containing lincomycin at various concentrations and repeated passages about every seven days. At the passage 5 only with 10 μg/ml of lincomycin, we did not detect mycoplasmas by two PCR based methods whereas O. tsutsugamushi continued good growth. During following four passages without lincomycin, mycoplasmas did not recover. These results suggested that mycoplasmas were completely eliminated from the high virulent strain of O. tsutsugamushi. Furthermore, by the same procedures with 10 μg/ml of lincomycin, we also eliminated mycoplasmas from a contaminated, low virulent strain of O. tsutsugamushi. Our additional assay showed that 50 μg/ml of lyncomycin did not inhibit the growth of O. tsutsugamushi, although MICs of many mycoplasmas contaminants were less than 6 μg/ml as shown previously. Conclusion: Our results showed an alternative method to eliminate mycoplasmas from the contaminated O. tsutsugamushi strains in place of in vivo passage through mice. Especially this notable method works for the decontamination not only from the high virulent strain also from the low virulent strain of O. tsutsugamushi. For further elimination, lincomycin at the limit concentration, which does not inhibit the growth of O. tsutsugamushi, can possibly eliminate most mycoplasmas from contaminated O. tsutsugamushi strains

Atg9a deficiency causes axon-specific lesions including neuronal circuit dysgenesis

Conditional knockout mice for Atg9a, specifically in brain tissue, were generated to understand the roles of ATG9A in the neural tissue cells. The mice were born normally, but half of them died within one wk, and none lived beyond 4 wk of age. SQSTM1/p62 and NBR1, receptor proteins for selective autophagy, together with ubiquitin, accumulated in Atg9a-deficient neurosoma at postnatal d 15 (P15), indicating an inhibition of autophagy, whereas these proteins were significantly decreased at P28, as evidenced by immunohistochemistry, electron microscopy and western blot. Conversely, degenerative changes such as spongiosis of nerve fiber tracts proceeded in axons and their terminals that were occupied with aberrant membrane structures and amorphous materials at P28, although no clear-cut degenerative change was detected in neuronal cell bodies. Different from autophagy, diffusion tensor magnetic resonance imaging and histological observations revealed Atg9a-deficiency-induced dysgenesis of the corpus callosum and anterior commissure. As for the neurite extensions of primary cultured neurons, the neurite outgrowth after 3 d culturing was significantly impaired in primary neurons from atg9a-KO mouse brains, but not in those from atg7-KO and atg16l1-KO brains. Moreover, this tendency was also confirmed in Atg9a-knockdown neurons under an atg7-KO background, indicating the role of ATG9A in the regulation of neurite outgrowth that is independent of autophagy. These results suggest that Atg9a deficiency causes progressive degeneration in the axons and their terminals, but not in neuronal cell bodies, where the degradations of SQSTM1/p62 and NBR1 were insufficiently suppressed. Moreover, the deletion of Atg9a impaired nerve fiber tract formation

下顎犬歯236歯の根管形態についての検討

To achieve the effect of mechanical preparation of root canals, transparent specimens of extracted 236 mandibular canines were investigated for canal configuration, thickness and curvature of the root canal, condition of any accessory canals, and location of the apical foramen. Fewer than 25% of the specimens showed accessory canals that were impossible to clean mechanically. The majority of the lateral branches were 0.15mm<and≦0.20mm. Although apical foramina located away from the apex were observed in 18% of the mandibular canines. All apical foramina were located within 0.5mm of the apex. Data on the thickness of the root and main canal in the apical portion and curvature of the root canal suggest that for adequate apical preparation, a #60 file must be able to reach the apical constriction

Impairment of starvation-induced and constitutive autophagy in Atg7-deficient mice

Autophagy is a membrane-trafficking mechanism that delivers cytoplasmic constituents into the lysosome/vacuole for bulk protein degradation. This mechanism is involved in the preservation of nutrients under starvation condition as well as the normal turnover of cytoplasmic component. Aberrant autophagy has been reported in several neurodegenerative disorders, hepatitis, and myopathies. Here, we generated conditional knockout mice of Atg7, an essential gene for autophagy in yeast. Atg7 was essential for ATG conjugation systems and autophagosome formation, amino acid supply in neonates, and starvation-induced bulk degradation of proteins and organelles in mice. Furthermore, Atg7 deficiency led to multiple cellular abnormalities, such as appearance of concentric membranous structure and deformed mitochondria, and accumulation of ubiquitin-positive aggregates. Our results indicate the important role of autophagy in starvation response and the quality control of proteins and organelles in quiescent cells

Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe

The Extragalactic Background Light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ~10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts (GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of gamma-ray flux attenuation by the EBL. We place upper limits on the gamma-ray opacity of the Universe at various energies and redshifts, and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the "baseline" model of Stecker et al. (2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A. Reimer, L.C. Reye

Evolution of living donor liver transplantation over 10 years: experience of a single center.

PURPOSE: To evaluate the changes in living donor liver transplantations (LDLTs) over the last 10 years, we analyzed our experience of performing LDLT in a single center. METHODS: We performed 73 LDLTs over the 10 years between 1997 and 2007 in Nagasaki University Hospital, Japan. RESULTS: Initially, from 1997 to 2003, LDLT was performed for pediatric patients; then, between 2004 and 2007, adult-to-adult LDLT was introduced, primarily for hepatocellular carcinoma (HCC) in liver cirrhosis. We also began performing LDLTs for adults with ABO-incompatible blood type combination in the latter period. As the number of adult-to-adult LDLTs increased, left-sided grafts became fi rst choice for these patients. Survival rates were 88.3%, 77.2%, 70.2% at 1, 3, and 5 years, respectively. There was a relatively low incidence of arterial complications, and although the incidence of biliary complications was high initially, it decreased with experience. Likewise, the operative time, blood loss, and hospital stay after LDLT also improved remarkably. CONCLUSION: Over the last 10 years the indications for, and operative techniques used in LDLT have changed dramatically, even in a single center in Japan

Local microbleeding facilitates IL-6– and IL-17–dependent arthritis in the absence of tissue antigen recognition by activated T cells

Local microbleeding induces the accumulation of Th17 cells and the development of IL-17– and IL-6–dependent arthritis in the absence of cognate antigen recognition by CD4+ T cells

BioHackathon series in 2011 and 2012: penetration of ontology and linked data in life science domains

The application of semantic technologies to the integration of biological data and the interoperability of bioinformatics analysis and visualization tools has been the common theme of a series of annual BioHackathons hosted in Japan for the past five years. Here we provide a review of the activities and outcomes from the BioHackathons held in 2011 in Kyoto and 2012 in Toyama. In order to efficiently implement semantic technologies in the life sciences, participants formed various sub-groups and worked on the following topics: Resource Description Framework (RDF) models for specific domains, text mining of the literature, ontology development, essential metadata for biological databases, platforms to enable efficient Semantic Web technology development and interoperability, and the development of applications for Semantic Web data. In this review, we briefly introduce the themes covered by these sub-groups. The observations made, conclusions drawn, and software development projects that emerged from these activities are discussed