131 research outputs found

    Intestinal Resident Yeast Candida glabrata Requires Cyb2p-Mediated Lactate Assimilation to Adapt in Mouse Intestine

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    The intestinal resident Candida glabrata opportunistically infects humans. However few genetic factors for adaptation in the intestine are identified in this fungus. Here we describe the C. glabrata CYB2 gene encoding lactate dehydrogenase as an adaptation factor for survival in the intestine. CYB2 was identified as a virulence factor by a silkworm infection study. To determine the function of CYB2, we analysed in vitro phenotypes of the mutant Δcyb2. The Δcyb2 mutant grew well in glucose medium under aerobic and anaerobic conditions, was not supersensitive to nitric oxide which has fungicidal-effect in phagocytes, and had normal levels of general virulence factors protease, lipase and adherence activities. A previous report suggested that Cyb2p is responsible for lactate assimilation. Additionally, it was speculated that lactate assimilation was required for Candida virulence because Candida must synthesize glucose via gluconeogenesis under glucose-limited conditions such as in the host. Indeed, the Δcyb2 mutant could not grow on lactate medium in which lactate is the sole carbon source in the absence of glucose, indicating that Cyb2p plays a role in lactate assimilation. We hypothesized that Cyb2p-mediated lactate assimilation is necessary for proliferation in the intestinal tract, as the intestine is rich in lactate produced by bacteria flora, but not glucose. The Δcyb2 mutant showed 100-fold decreased adaptation and few cells of Saccharomyces cerevisiae can adapt in mouse ceca. Interestingly, C. glabrata could assimilate lactate under hypoxic conditions, dependent on CYB2, but not yeast S. cerevisiae. Because accessible oxygen is limited in the intestine, the ability for lactate assimilation in hypoxic conditions may provide an advantage for a pathogenic yeast. From those results, we conclude that Cyb2p-mediated lactate assimilation is an intestinal adaptation factor of C. glabrata

    A simple and rapid chemiluminescence assay for on-site analysis of paraquat using a portable luminometer

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    Paraquat (N,N′-dimethyl-4,4′-bipyridinium dichloride) is one of the most widely used herbicides owing to its high efficacy and low environmental persistence. However, because paraquat has significant acute toxicity, fatalities are often caused by accidental or voluntary ingestion of paraquat. In consideration of the strong toxicity and fast-Acting property of paraquat, on-site analysis at accident scenes should be effective in facilitating immediate medical treatment. In this study, a simple and rapid chemiluminescence assay using a portable luminometer was developed for on-site analysis of paraquat. The proposed assay is based on luminol chemiluminescence detection of superoxide anion radical resulting from the redox reaction between paraquat and dithiothreitol. Intense chemiluminescence was observed after mixing of paraquat and dithiothreitol in the presence of luminol. Because the chemiluminescence intensity was proportional to the concentration of paraquat, a quantitative measurement of paraquat was possible. The calibration curve for standard paraquat solution was linear from 0.025 to 2.5 μM with the correlation coefficient of 0.992; the detection limit (blank + 3SD) was 22 nM. The proposed assay was applied to determine paraquat in beverage samples after a cation exchange clean-up procedure. Given that the portable luminometer used in this study is small and lightweight, the proposed assay should be useful for on-site analysis of paraquat

    Detection of sentinel and non-sentinel lymph node micrometastases by complete serial sectioning and immunohistochemical analysis for gastric cancer

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    <p>Abstract</p> <p>Background</p> <p>We investigated the presence and distribution of the sentinel and the non-sentinel node micrometastases using complete serial sectioning and immunohistochemical staining (IHC), to inspect whether lymph node micrometastases spread to the sentinel lymph nodes first.</p> <p>Methods</p> <p>A total of 35 patients, who underwent gastrectomy with a sentinel lymph node biopsy for gastric cancer, were enrolled in this study. Total of 1028 lymph nodes of 35 patients having gastric cancer without metastasis of lymph node by permanent section with hematoxylin and eosin staining (H&E) were selected. There were 252 sentinel nodes and the other 776 were non-sentinel nodes. All nodes were sectioned serially and stained alternately with H&E and IHC. Lymph node micrometastases was defined as proving to be positive first either the IHC or the complete serial sectioning.</p> <p>Results</p> <p>Micrometastases were detected in 4 (11%) of the 35 patients, 6 (0.58%) of 1028 nodes. Of these 4 patients, 3 had micrometastases exclusively in sentinel nodes, and the other had micrometastasis in both sentinel and non-sentinel nodes. There was no patient who had the micrometasitases only in non-sentinel nodes.</p> <p>Conclusion</p> <p>These results support the concept that lymph node micrometastasis of gastric cancer spreads first to sentinel nodes.</p

    Clinical characteristics of non-radiographic versus radiographic axial spondyloarthritis in Asia and non-radiographic axial spondyloarthritis in other regions: results of the cross-sectional ASAS-COMOSPA study

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    Objectives To delineate characteristics of non-radiographic axial spondyloarthritis (nr-axSpA) in Asia versus non-Asian regions, and compare radiographic axSpA (r-axSpA) with nr-axSpA within Asia. Methods Data were collected from the Assessment of SpondyloArthritis international Society-COMOrbidities in SPondyloArthritis database. Categorising patients by region, we compared clinical characteristics between nr-axSpA from Asia vs elsewhere (Europe, the Americas and Africa). Within Asians, we additionally compared patient characteristics of those with nr-axSpA versus r-axSpA. Results Among 3984 SpA cases, 1094 were from Asian countries. Of 780 axSpA patients in Asia, 112 (14.4%) had nr-axSpA, less than in non-Asian countries (486/1997, 24.3%). Nr-axSpA patients in Asia were predominantly male (75.9% vs 47.1%), younger at onset (22.8 vs 27.8 years) and diagnosis (27.2 vs 34.5 years), and experienced less diagnostic delay (1.9 vs 2.9 years) compared with nr-axSpA in non-Asian countries. Nr-axSpA in Asia exhibited higher human leucocyte antigens-B27 prevalence (90.6% vs 61.9%), fewer peripheral SpA features (53.6% vs 66.3%) and similar extra-articular and comorbid disease rates compared with those with nr-axSpA in non-Asian countries. Disease activity, functional impairment and MRI sacroiliitis were less in nr-axSpA in Asia, with higher rates of non-steroidal anti-inflammatory drug response and less methotrexate and biological disease-modifying antirheumatic drugs use. Within Asia, r-axSpA showed higher disease activity and structural damage compared with nr-axSpA, with no differences in other features. Conclusion Among axSpA, lower frequency of nr-axSpA was observed in Asia. Our results offer an opportunity to better understand clinical characteristics and optimise diagnostic strategies, such as ensuring access and availability of MRI resources for accurate diagnosis of nr-axSpA in Asia.Pathophysiology and treatment of rheumatic disease

    The history of human populations in the Japanese Archipelago inferred from genome-wide SNP data with a special reference to the Ainu and the Ryukyuan populations

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    The Japanese Archipelago stretches over 4000 km from north to south, and is the homeland of the three human populations; the Ainu, the Mainland Japanese and the Ryukyuan. The archeological evidence of human residence on this Archipelago goes back to 430 000 years, and various migration routes and root populations have been proposed. Here, we determined close to one million single-nucleotide polymorphisms (SNPs) for the Ainu and the Ryukyuan, and compared these with existing data sets. This is the first report of these genome-wide SNP data. Major findings are: (1) Recent admixture with the Mainland Japanese was observed for more than one third of the Ainu individuals from principal component analysis and frappe analyses; (2) The Ainu population seems to have experienced admixture with another population, and a combination of two types of admixtures is the unique characteristics of this population; (3) The Ainu and the Ryukyuan are tightly clustered with 100% bootstrap probability followed by the Mainland Japanese in the phylogenetic trees of East Eurasian populations. These results clearly support the dual structure model on the Japanese Archipelago populations, though the origins of the Jomon and the Yayoi people still remain to be solved

    Allyl Isothiocyanate that Induces GST and UGT Expression Confers Oxidative Stress Resistance on C. elegans, as Demonstrated by Nematode Biosensor

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    Electrophilic xenobiotics and endogenous products from oxidative stresses induce the glutathione S-transferases (GSTs), which form a large family within the phase II enzymes over both animal and plant kingdoms. The GSTs thus induced in turn detoxify these external as well as internal stresses. Because these stresses are often linked to ageing and damage to health, the induction of phase II enzymes without causing adverse effects would be beneficial in slowing down ageing and keeping healthy conditions. for use as a nematode biosensor. With the nematode biosensor, we found that AITC induced GST expression and conferred tolerance on the nematode against various oxidative stresses. We also present evidence that the transcription factor SKN-1 is involved in regulating the GST expression induced by AITC.We show the applicability of the nematode biosensor for discovering and evaluating functional food substances and chemicals that would provide anti-ageing or healthful benefits

    Chinese herb mix Tiáo-Gēng-Tāng possesses antiaging and antioxidative effects and upregulates expression of estrogen receptors alpha and beta in ovariectomized rats

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    <p>Abstract</p> <p>Background</p> <p>Herb mixtures are widely used as an alternative to hormonal therapy in China for treatment of the menopausal syndrome. However, composition of these herb mixtures are complex and their working mechanism is often unknown. This study investigated the effect of Tiáo-Gēng-Tāng (TG-decoction), a Chinese herbal mixture extract, in balancing female hormones, regulating expression of estrogen receptors (ERs), and preventing aging-related tissue damage.</p> <p>Methods</p> <p>Ovariectomized 5-month-old female rats were used to model menopause and treated with either TG-decoction or conjugated estrogen for 8 weeks. Estradiol (E<sub>2</sub>), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured in serum and in the hypothalamus. Hypothalamic expression of estrogen receptor (ER) alpha and beta were studied by real-time PCR and western blotting. Total antioxidant capacity (T-AOC), oxidation indicator superoxide dismutase (SOD) activity and tissue damage parameter malondialdehyde (MDA) were measured using standard assays. Aging-related ultrastructural alterations in mitochondria were studied in all animals by transmission electron microscopy.</p> <p>Results</p> <p>TG-decoction-treatment elevated E<sub>2 </sub>and lowered FSH in serum of ovariectomized rats. The potency and efficacy of TG-decoction on the hypothalamus was generally weaker than that of conjugated estrogens. However, TG-decoction was superior in upregulating expression of ERα and β. TG-decoction increased hypothalamic SOD and T-AOC levels and decreased MDAlevels and mitochondrial damage in hypothalamic neurons.</p> <p>Conclusions</p> <p>TG-decoction balances female hormones similarly to conjugated estrogens but less effectively. However, it is superior in up regulating ERα and β and exhibits antioxidative antiaging activities. Whilst it shares similar effects with estrogen, TG-decoction also seems to have distinctive and more complex functions and activities.</p
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