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1.
A novel actinobacterium, designated strain NEAU-ML12T, was isolated from a millipede (Kronopolites svenhedind Verhoeff), which was collected from Fenghuang Mountain in Wuchang, Heilongjiang Province, north China. The strain was characterized using a polyphasic approach. Strain NEAU-ML12T was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Rhodococcus. 16S rRNA gene sequence similarity analysis showed that the strain NEAU-ML12T belongs to the genus Rhodococcus, and was most closely related to Rhodococcus tukisamuensis Mb8T (98.9 %) and Rhodococcus koreensis DNP505T (97.7 %). Phylogenetic analysis based on 16S rRNA gene sequences also demonstrated that strain NEAU-ML12T should be classified in the genus Rhodococcus, forming a distinct clade with R. tukisamuensis Mb8T supported by a 99 % bootstrap value. However, the DNA–DNA relatedness between strain NEAU-ML12T and R. tukisamuensis Mb8T was found to be 41.9 ± 0.7 %. Furthermore, strain NEAU-ML12T could also be differentiated from R. tukisamuensis Mb8T and other closely related strains (R. koreensis DNP505T and Rhodococcus maanshanensis M712T) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-ML12T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kronopolitis sp. nov. is proposed. The type strain is NEAU-ML12T (=CGMCC 4.7145T = DSM 46702T).  相似文献   
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The second messenger NAADP triggers Ca2+ release from endo-lysosomes. Although two-pore channels (TPCs) have been proposed to be regulated by NAADP, recent studies have challenged this. By generating the first mouse line with demonstrable absence of both Tpcn1 and Tpcn2 expression (Tpcn1/2−/−), we show that the loss of endogenous TPCs abolished NAADP-dependent Ca2+ responses as assessed by single-cell Ca2+ imaging or patch-clamp of single endo-lysosomes. In contrast, currents stimulated by PI(3,5)P2 were only partially dependent on TPCs. In Tpcn1/2−/− cells, NAADP sensitivity was restored by re-expressing wild-type TPCs, but not by mutant versions with impaired Ca2+-permeability, nor by TRPML1. Another mouse line formerly reported as TPC-null likely expresses truncated TPCs, but we now show that these truncated proteins still support NAADP-induced Ca2+ release. High-affinity [32P]NAADP binding still occurs in Tpcn1/2−/− tissue, suggesting that NAADP regulation is conferred by an accessory protein. Altogether, our data establish TPCs as Ca2+-permeable channels indispensable for NAADP signalling.  相似文献   
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Background

Studies are limited on pegylated interferon (Peg-IFN) therapy for chronic hepatitis B (CHB) patients who failed or relapsed on previous antiviral therapy.

Objectives

We aimed to investigate the effect of Peg-IFN therapy in treatment-experienced CHB patients.

Study Design

A total of 57 treatment-experienced CHB patients at two medical centers were enrolled. All of the patients were treated with Peg-IFN α-2a at 180 μg weekly for 24 or 48 weeks. The hepatitis B serological markers and viral loads were tested every 3 months until 1 year after stopping Peg-IFN therapy. The endpoints were HBV DNA <2000IU/mL, hepatitis B e antigen (HBeAg) seroconversion, and a hepatitis B surface antigen (HBsAg) loss at 12 months post-treatment.

Results

In HBeAg-positive patients, 25.0%, 29.2%, and 12.5% of the patients achieved HBeAg seroconversion, HBV DNA <2000 IU/mL and a combined response, respectively, at 12 months post-treatment. Prior IFN therapy, a high baseline ALT level, a low creatinine level, undetectable HBV DNA at 12 weeks and a decline in HBV DNA >2 log10 IU/mL at 12 weeks of therapy were factors associated with treatment response. In HBeAg-negative patients, 9.1%, 15.2%, and 6.1% of the patients achieved undetectable HBV DNA, HBV DNA <2000 IU/mL, and an HBsAg loss, respectively, at 12 months post-treatment. No factor was significantly associated with the treatment response in the HBeAg-negative patients. The median HBsAg level declined from 3.4 to 2.6 log10 IU/mL in all the patients, and the 5-year cumulative rate of the HBsAg loss was 9.8% in the HBeAg-negative patients. Overall, none of the patients prematurely discontinued the Peg-IFN therapy.

Conclusions

Peg-IFN re-treatment is effective for a proportion of HBeAg-positive treatment-experienced patients; it has limited efficacy for HBeAg-negative treatment-experienced patients. Peg-IFN might facilitate HBsAg loss in HBeAg-negative treatment-experienced patients.  相似文献   
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In the X-ray structure of the staphylococcal nuclease–Ca2+ ?3′,5′-pdTp complex, the conformation of the inhibitor 3′,5′-pdTp is distroteed Lys-70* and Lys-71* from an adjacent molecule of staphylococcal nuclease (Loll, P.J., Lattman, E.E. Proteins 5 : 183-201, 1989). In order to correct this crystal packing problem, the solution conformation of enzyme-bound 3′,5′-pdTp in the staphylococcal nuclease–metal–pdTp Complex determined by NMR methods was docked into the X-ray structure of the enzyme [Weber, D. J., Serpersu, E. H., Gittis, A. G., Lattman, E. E., Mildvan, A. S. (preceding paper)]. In the NMR-docked structure, the 5′-phophate of 3′,5′-pdTp overlaps with that in the X-ray Structure. However the 3′-phosphate accepts a hydrogen bond from Lys-49 (2.89Å) rather than from Lys-84 (8.63 Å), and N3 of thymine donates a hydrogen bond to the OH of Tyr-115 (3.16 Å) which does not occur in the X-ray structure (5.28 Å). These interactions have been tested by binding studies of 3′,5′-pdTp, Ca2+, and Mn2+ to the K49A, K84A, and Y115A mutants of staphylococcal nuclease using water proton relaxation rate and EPR methods. Each mutant was fully active and structurally intact, as found by CD and two-dimensional NMR spectroscopy, but bound Ca2+ 9.1- to 9.9-fold more weakly than the wild-type enzyme. While thye K84A mutation did not significantly weaken 3′,5′-pdTp binding to the enzyme (1.5 ± 0.7 fold), the K49A mutation weakened 3′,5′-pdTp binding to the enzyme by the factor of 4.4 ± 1.8-fold. Similarly, the Y115A mutation weakened 3′,5′-pdTp binding to the enzyme 3.6 ± 1.6-fold. Comparable weakening effects of these mutations were found on the binding of Ca2+-3′,5′-pdTp. These results are more readily explained by the NMR-docked structure of staphylococcal nuclease-metal-3′,5′-pdTp than by the X-ray structure. © 1993 Wiley-Liss, Inc.  相似文献   
9.
Receptor-tyrosine-kinase-like orphan receptor 1 (ROR1) is expressed during embryogenesis and by certain leukemias, but not by normal adult tissues. Here we show that the neoplastic cells of many human breast cancers express the ROR1 protein and high-level expression of ROR1 in breast adenocarcinoma was associated with aggressive disease. Silencing expression of ROR1 in human breast cancer cell lines found to express this protein impaired their growth in vitro and also in immune-deficient mice. We found that ROR1 could interact with casein kinase 1 epsilon (CK1ε) to activate phosphoinositide 3-kinase-mediated AKT phosphorylation and cAMP-response-element-binding protein (CREB), which was associated with enhanced tumor-cell growth. Wnt5a, a ligand of ROR1, could induce ROR1-dependent signaling and enhance cell growth. This study demonstrates that ROR1 is expressed in human breast cancers and has biological and clinical significance, indicating that it may be a potential target for breast cancer therapy.  相似文献   
10.
絮凝颗粒粒度分布对自絮凝酵母SPSC01乙醇耐受能力的影响   总被引:1,自引:0,他引:1  
利用激光聚焦反射式颗粒测量系统, 通过调节不同的搅拌速率, 得到了分批补料培养条件下粒度分布不同的四个絮凝酵母SPSC01颗粒群体, 进而对絮凝颗粒群体分布对乙醇耐受性进行了系统研究。经过6 h、20%乙醇的冲击, 颗粒粒度为100、200、300和400 mm的自絮凝酵母SPSC01的存活率分别为3.5%、26.7%、48.8%和37.6%。这表明不同粒度分布的絮凝颗粒群体乙醇耐受性具有明显差别, 在一定粒度范围内乙醇耐受性达到最高, 乙醇耐受性最高的酵母群体的乙醇得率系数85.5%, 比乙醇耐性最低的颗粒群体提高了7.2%。粒度为100、200和300 mm的自絮凝酵母颗粒群体总麦角固醇、游离麦角固醇及海藻糖含量与粒度大小成正相关, 但在粒度为400 mm的絮凝颗粒群体中总麦角固醇、游离麦角固醇及海藻糖含量呈下降趋势, 与其乙醇耐性低于300 mm絮凝颗粒的结果相一致。对细胞膜透性的研究表明, 颗粒粒度为300 mm的絮凝酵母颗粒细胞膜通透性(P′)最低, 分别仅为颗粒粒度为100 mm和200 mm颗粒群体的43%和52%, 表明粒度分布不同的絮凝颗粒群体乙醇耐性的差别与细胞膜透性密切相关。  相似文献   
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