587 research outputs found

    Hepatitis B Virus X Protein Impairs Hepatic Insulin Signaling Through Degradation of IRS1 and Induction of SOCS3

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    Hepatitis B virus (HBV) is a major cause of chronic liver diseases, and frequently results in hepatitis, cirrhosis, and ultimately hepatocellular carcinoma. The role of HCV in associations with insulin signaling has been elucidated. However, the pathogenesis of HBV-associated insulin signaling remains to be clearly characterized. Therefore, we have attempted to determine the mechanisms underlying the HBV-associated impairment of insulin signaling.The expressions of insulin signaling components were investigated in HBx-transgenic mice, HBx-constitutive expressing cells, and transiently HBx-transfected cells. Protein and gene expression was examined by Western blot, immunohistochemistry, RT-PCR, and promoter assay. Protein-protein interaction was detected by coimmunoprecipitation.HBx induced a reduction in the expression of IRS1, and a potent proteasomal inhibitor blocked the downregulation of IRS1. Additionally, HBx enhanced the expression of SOCS3 and induced IRS1 ubiquitination. Also, C/EBPalpha and STAT3 were involved in the HBx-induced expression of SOCS3. HBx interfered with insulin signaling activation and recovered the insulin-mediated downregulation of gluconeogenic genes.These results provide direct experimental evidences for the contribution of HBx in the impairment of insulin signaling

    Pathogenesis of Nonalcoholic Steatohepatitis and Hormone-Based Therapeutic Approaches

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    Non-alcoholic fatty liver disease (NAFLD) is an emerging global health problem and a potential risk factor for type 2 diabetes, cardiovascular disease, and chronic kidney disease. Nonalcoholic steatohepatitis (NASH), an advanced form of NAFLD, is a predisposing factor for development of cirrhosis and hepatocellular carcinoma. The increasing prevalence of NASH emphasizes the need for novel therapeutic approaches. Although therapeutic drugs against NASH are not yet available, fundamental insights into the pathogenesis of NASH have been made during the past few decades. Multiple therapeutic strategies have been developed and are currently being explored in clinical trials or preclinical testing. The pathogenesis of NASH involves multiple intracellular/extracellular events in various cell types in the liver or crosstalk events between the liver and other organs. Here, we review current findings and knowledge regarding the pathogenesis of NASH, focusing on the most recent advances. We also highlight hormone-based therapeutic approaches for treatment of NASH

    Effects of Substrate to Inoculum Ratio on the Biochemical Methane Potential of Piggery Slaughterhouse Wastes

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    The aim of this study was to assess the effect of substrate to inoculum ratio (S/I ratio) on the biochemical methane potential (BMP) and anaerobic biodegradability (Ddeg) of different piggery slaughterhouse wastes, such as piggery blood, intestine residue, and digestive tract content. These wastes were sampled from a piggery slaughterhouse located in Kimje, South Korea. Cumulative methane production curves for the wastes were obtained from the anaerobic batch fermentation having different S/I ratios of 0.1, 0.5, 1.0, and 1.5. BMP and anaerobic biodegradabilities (Ddeg) of the wastes were calculated from cumulative methane production data for the tested conditions. At the lowest S/I ration of 0.1, BMPs of piggery blood, intestine residue, and digestive tract content were determined to be 0.799, 0.848, and 1.076 Nm3 kg−1-VSadded, respectively, which were above the theoretical methane potentials of 0.539, 0.644, and 0.517 Nm3 kg−1-VSadded for blood, intestine residue, and digestive tract content, respectively. However, BMPs obtained from the higher S/I ratios of 0.5, 1.0, and 1.5 were within the theoretical range for all three types of waste and were not significantly different for the different S/I ratios tested. Anaerobic biodegradabilities calculated from BMP data showed a similar tendency. These results imply that, for BMP assay in an anaerobic reactor, the S/I ratio of anaerobic reactor should be above 0.1 and the inoculum should be sufficiently stabilized to avoid further degradation during the assay

    Prognostic Value of Postoperative CEA Clearance in Rectal Cancer Patients with High Preoperative CEA Levels

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    PURPOSE: We determined the prognostic value of carcinoembryonic antigen (CEA) clearance after tumor resection with serial evaluation of postoperative CEA levels in rectal cancer. METHODS: Between 1994 and 2004, we retrospectively reviewed 122 patients with rectal cancer whose serum CEA levels were measured on the preoperative day and postoperative days 7 and 30. Patients with preoperative CEA levels <5.0 ng/ml were excluded. An exponential trend line was drawn using the three CEA values. Patients were categorized into three groups based on R(2) values calculated through trend line, which indicates the correlation coefficient between exponential graph and measured CEA values: exponential decrease group (group 1: 0.9 < R(2) < or = 1.0), nearly exponential decrease group (group 2: 0.5 < R(2) < or = 0.9), and randomized clearance group (group 3: 0.5 < or = R(2)). We then analyzed the CEA clearance pattern as a prognostic indicator. RESULTS: With a median follow-up of 57 months, the 5-year overall survival was 62.3% vs. 48.1% vs. 25% and the 5-year disease-free survival was 58.6% vs. 52.7% vs. 25% among groups 1, 2, and 3 (P = 0.014, P = 0.027, respectively) in patients with stage III rectal cancer. For those with stage II rectal cancer, the 5-year overall survival rate of group 1 was significantly better than groups 2 and 3 (88.8% vs. 74.1%, respectively, P = 0.021). CONCLUSIONS: the postoperative pattern of CEA clearance is a useful prognostic determinant in patients with rectal cancer. Patients with a randomized pattern of CEA clearance after tumor resection should be regarded as having the possibility of a persistent CEA source and may require consideration of intensive follow-up or adjuvant therapy.ope

    Practical Review of Olfactory Training and COVID-19

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    Olfactory disorders one of the most frequent distinctive symptoms of COVID-19 infection. COVID-19-induced olfactory disorder can be classified as post-infectious olfactory dysfunction (PIOD). The effect of drugs on olfactory disorder following upper respiratory infection, including PIOD, has not been clearly established, which adds to the difficulty with treating the disorder. However, the effect of olfactory training on PIOD has been confirmed by numerous studies. As such, olfactory training is gaining attention, and has taken on greater importance, as the sole treatment for COVID-19–induced olfactory disorder in this pandemic age. This review describes the effect of olfactory training for COVID-19–induced olfactory disorder by analyzing the relevant literature

    Measured sodium excretion is associated with cardiovascular outcomes in non-dialysis CKD patients: results from the KNOW-CKD study

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    BackgroundThere are insufficient studies on the effect of dietary salt intake on cardiovascular (CV) outcomes in chronic kidney disease (CKD) patients, and there is no consensus on the sodium (Na) intake level that increases the risk of CV disease in CKD patients. Therefore, we investigated the association between dietary salt intake and CV outcomes in CKD patients.MethodsIn the Korean cohort study for Outcome in patients with CKD (KNOW-CKD), 1,937 patients were eligible for the study, and their dietary Na intake was estimated using measured 24h urinary Na excretion. The primary outcome was a composite of CV events and/or all-cause death. The secondary outcome was a major adverse cardiac event (MACE).ResultsAmong 1,937 subjects, there were 205 (10.5%) events for the composite outcome and 110 (5.6%) events for MACE. Compared to the reference group (urinary Na excretion&lt; 2.0g/day), the group with the highest measured 24h urinary Na excretion (urinary Na excretion ≥ 8.0g/day) was associated with increased risk of both the composite outcome (hazard ratio 3.29 [95% confidence interval 1.00-10.81]; P = 0.049) and MACE (hazard ratio 6.28 [95% confidence interval 1.45-27.20]; P = 0.013) in a cause-specific hazard model. Subgroup analysis also showed a pronounced association between dietary salt intake and the composite outcome in subgroups of patients with abdominal obesity, female, lower estimated glomerular filtration rate (&lt; 60 ml/min per 1.73m2), no overt proteinuria, or a lower urinary potassium-to-creatinine ratio (&lt; 46 mmol/g).ConclusionA high-salt diet is associated with CV outcomes in non-dialysis CKD patients

    Clinical Impact of Tumor Regression Grade after Preoperative Chemoradiation for Locally Advanced Rectal Cancer: Subset Analyses in Lymph Node Negative Patients

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    BACKGROUND: We investigated the prognostic significance of tumor regression grade (TRG) after preoperative chemoradiation therapy (preop-CRT) for locally advanced rectal cancer especially in the patients without lymph node metastasis. METHODS: One-hundred seventy-eight patients who had cT3/4 tumors were given 5,040 cGy preoperative radiation with 5-fluorouracil/leucovorin chemotherapy. A total mesorectal excision was performed 4-6 weeks after preop-CRT. TRG was defined as follows: grade 1 as no cancer cells remaining; grade 2 as cancer cells outgrown by fibrosis; grade 3 as a minimal presence or absence of regression. The prognostic significance of TRG in comparison with histopathologic staging was analyzed. RESULTS: Seventeen patients (9.6%) showed TRG1. TRG was found to be significantly associated with cancer-specific survival (CSS; P = 0.001) and local recurrence (P = 0.039) in the univariate study, but not in the multivariate analysis. The ypN stage was the strongest prognostic factor in the multivariate analysis. Subgroup analysis revealed TRG to be an independent prognostic factor for the CSS of ypN0 patients (P = 0.031). TRG had a stronger impact on the CSS of ypN (-) patients (P = 0.002) than on that of ypN (+) patients (P = 0.521). In ypT2N0 and ypT3N0, CSS was better for TRG2 than for TRG3 (P = 0.041, P = 0.048), and in ypN (-) and TRG2 tumors, CSS was better for ypT1-2 than for ypT3-4 (P = 0.034). CONCLUSION: TRG was found to be the strongest prognostic factor in patients without lymph node metastasis (ypN0), and different survival was observed according to TRG among patients with a specific histopathologic stage. Thus, TRG may provide an accurate prediction of prognosis and may be used for f tailoring treatment for patients without lymph node metastasis.ope

    Arabidopsis U2AF65 Regulates Flowering Time and the Growth of Pollen Tubes

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    During pre-mRNA splicing, U2 small nuclear ribonucleoprotein auxiliary factor 65 (U2AF65) interacts with U2AF35 and splicing factor 1 (SF1), allowing for the recognition of the 3′-splice site by the ternary complex. The functional characterization of U2AF65 homologs has not been performed in Arabidopsis thaliana yet. Here, we show that normal plant development, including floral transition, and male gametophyte development, requires two Arabidopsis U2AF65 isoforms (AtU2AF65a and AtU2AF65b). Loss-of-function mutants of these two isoforms displayed opposite flowering phenotypes: atu2af65a mutants showed late flowering, whereas atu2af65b mutants were characterized by slightly early flowering, as compared to that in the wild-type (Col-0) plants. These abnormal flowering phenotypes were well-correlated with the expression patterns of the flowering time genes such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT). However, the two atu2af65 mutants did not display any morphological abnormalities or alterations in abiotic stress tests. Double mutation of the AtU2AF65a and AtU2AF65b genes resulted in non-viable seeds due to defective male gametophyte. In vitro pollen germination test revealed that mutations in both AtU2AF65a and AtU2AF65b genes significantly impaired pollen tube growth. Collectively, our findings suggest that two protein isoforms of AtU2AF65 are differentially involved in regulating flowering time and display a redundant role in pollen tube growth
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