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Summary: Background: Chronic hepatitis B virus (HBV) infection is a great health burden with geographical variations. Aims: To explore genetic variants associated with chronic HBV infection. Methods: The study included 15 352 participants seropositive for HBV core antibodies in Taiwan Biobank. Among them, 2591 (16.9%) seropositive for HBV surface antigen (HBsAg) were defined as having chronic HBV infection. All participants were examined for whole‐genome genotyping by Axiom‐Taiwan Biobank Array. The human leucocyte antigen (HLA) imputation was performed after identification of the variants within the region. Logistic regressions were used to estimate odds ratios (ORs) with 95% confidence intervals. Correlations of different HLA allele frequencies with HBsAg seroprevalence were evaluated across worldwide populations by Pearson correlation coefficients. Epitope prediction was performed for HLA alleles using NetMHCIIpan method. Results: Located within a cluster of 450 single nucleotide polymorphisms in HLA class II, rs7770370 (P = 2.73 × 10−35) was significantly associated with HBV chronicity (Pcorrected < 8.6 × 10−8). Imputation analyses showed that HLA‐DPA1*02:02 and HLA‐DPB1*05:01 were associated with chronic HBV, with adjusted ORs of 1.43 (1.09‐1.89) and 1.61 (1.29‐2.01). These allele frequencies were positively correlated with global HBsAg seroprevalence, with R of 0.75 and 0.62 respectively (P < 0.05). HLA‐DRB1*13:02, HLA‐DQA1* 01:02 and HLA‐DQB1*06:09 associated with HBV chronicity negatively, with adjusted ORs of 0.31 (0.17‐0.58), 0.70 (0.56‐0.87) and 0.33 (0.18‐0.63). These HLA alleles had various binding affinities to the predicted epitopes derived from HBV nucleocapsid protein. Conclusions: HLA class II variants are relevant for chronicity after HBV acquisition. [ABSTRACT FROM AUTHOR]

Oestrogens have been reported to attenuate acute inflammation in sepsis. In this study, the effects of long-term oestrogen replacement with 17β-oestradiol (E2) on endotoxaemia-induced circulatory dysfunction and multiple organ dysfunction syndrome were evaluated in ovariectomized (Ovx) rats. E2 (50 μg/kg, s.c., 3 times/week) was administered for 8 weeks, followed by the induction of endotoxaemia by intravenous infusion of lipopolysaccharides (LPS; 30 mg/kg/4 hrs). Oestrogen deficiency induced by ovariectomy for 9 weeks augmented the LPS-induced damage, including endotoxic shock, myocardial contractile dysfunction, renal dysfunction and rhabdomyolysis. Cardiac levels of NF-κB p65, iNOS and oxidized glutathione, free radical production in skeletal muscles, myoglobin deposition in renal tubules, and plasma levels of plasminogen activator inhibitor-1, TNF-α, and IL-6 were more pronounced in the Ovx + LPS group than in the Sham + LPS group. Long-term treatment of E2 prevented this amplified damage in Ovx rats. Six hours after LPS initiation, activation of the autophagic process, demonstrated by increases in Atg12 and LC3B-II/LC3B-I ratios, and induction of haem oxygenase (HO)-1 and heat-shock protein (HSP) 70 protein expression in myocardium were increased significantly in the Ovx + E2 + LPS group. These results suggest that activation of autophagy and induction of HO-1 and HSP70 contribute to the protective effect of long-term E2 replacement on multiple organ dysfunction syndrome in endotoxaemia. [ABSTRACT FROM AUTHOR]

There has been growing interest in polyproline type II (PPII) helices since PPII helices have been found in folded and unfolded proteins and involved in a variety of biological activities. Polyproline can also form type I helices (PPI) which are very different from PPII conformation and only exist in certain organic solvents. Recent studies have shown that stereoelectronic effects play a critical role in stabilizing a PPI or PPII helix. Here, we have synthesized a series of host-guest peptides with an electron-withdrawing substituent at the 4 R or 4 S position of proline and used a kinetic approach to further explore stereoelectronic effects on the transition barrier of the interconversion between PPI and PPII conformations. Time-dependent circular dichroism measurements revealed that the rates of PPII → PPI conversion were reduced upon incorporating the hydroxyl-, fluoro-, and methoxy-groups at the 4 R position while the rates would be increased if these substituents were at the 4 S position. We quantified the changes in transition free energy by comparing their rate constants. (4 R,2 S)-4-Fluoroproline and (4 S,2 S)-4-fluoroproline have the largest effect on the transition energy barrier for PPII → PPI conversion. Our results provide important insights into the role of stereoelectronic effects on the PPII → PPI transition state barrier, which has not been reported in past thermodynamic studies. [ABSTRACT FROM AUTHOR]