128 research outputs found

    Transforming Growth Factor-β1 Suppresses Hepatitis B Virus Replication by the Reduction of Hepatocyte Nuclear Factor-4α Expression

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    Several studies have demonstrated that cytokine-mediated noncytopathic suppression of hepatitis B virus (HBV) replication may provide an alternative therapeutic strategy for the treatment of chronic hepatitis B infection. In our previous study, we showed that transforming growth factor-beta1 (TGF-β1) could effectively suppress HBV replication at physiological concentrations. Here, we provide more evidence that TGF-β1 specifically diminishes HBV core promoter activity, which subsequently results in a reduction in the level of viral pregenomic RNA (pgRNA), core protein (HBc), nucleocapsid, and consequently suppresses HBV replication. The hepatocyte nuclear factor 4alpha (HNF-4α) binding element(s) within the HBV core promoter region was characterized to be responsive for the inhibitory effect of TGF-β1 on HBV regulation. Furthermore, we found that TGF-β1 treatment significantly repressed HNF-4α expression at both mRNA and protein levels. We demonstrated that RNAi-mediated depletion of HNF-4α was sufficient to reduce HBc synthesis as TGF-β1 did. Prevention of HNF-4α degradation by treating with proteasome inhibitor MG132 also prevented the inhibitory effect of TGF-β1. Finally, we confirmed that HBV replication could be rescued by ectopic expression of HNF-4α in TGF-β1-treated cells. Our data clarify the mechanism by which TGF-β1 suppresses HBV replication, primarily through modulating the expression of HNF-4α gene

    Imaging findings in craniofacial childhood rhabdomyosarcoma

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    Rhabdomyosarcoma (RMS) is the commonest paediatric soft-tissue sarcoma constituting 3–5% of all malignancies in childhood. RMS has a predilection for the head and neck area and tumours in this location account for 40% of all childhood RMS cases. In this review we address the clinical and imaging presentations of craniofacial RMS, discuss the most appropriate imaging techniques, present characteristic imaging features and offer an overview of differential diagnostic considerations. Post-treatment changes will be briefly addressed

    Subcellular trafficking of the substrate transporters GLUT4 and CD36 in cardiomyocytes

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    Cardiomyocytes use glucose as well as fatty acids for ATP production. These substrates are transported into the cell by glucose transporter 4 (GLUT4) and the fatty acid transporter CD36. Besides being located at the sarcolemma, GLUT4 and CD36 are stored in intracellular compartments. Raised plasma insulin concentrations and increased cardiac work will stimulate GLUT4 as well as CD36 to translocate to the sarcolemma. As so far studied, signaling pathways that regulate GLUT4 translocation similarly affect CD36 translocation. During the development of insulin resistance and type 2 diabetes, CD36 becomes permanently localized at the sarcolemma, whereas GLUT4 internalizes. This juxtaposed positioning of GLUT4 and CD36 is important for aberrant substrate uptake in the diabetic heart: chronically increased fatty acid uptake at the expense of glucose. To explain the differences in subcellular localization of GLUT4 and CD36 in type 2 diabetes, recent research has focused on the role of proteins involved in trafficking of cargo between subcellular compartments. Several of these proteins appear to be similarly involved in both GLUT4 and CD36 translocation. Others, however, have different roles in either GLUT4 or CD36 translocation. These trafficking components, which are differently involved in GLUT4 or CD36 translocation, may be considered novel targets for the development of therapies to restore the imbalanced substrate utilization that occurs in obesity, insulin resistance and diabetic cardiomyopathy

    Altimetry for the future: Building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Treatment of anorexia nervosa:A multimethod investigation translating experimental neuroscience into clinical practice

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    Background Anorexia nervosa (AN) is a severe psychiatric condition and evidence on how to best treat it is limited. Objectives This programme consists of seven integrated work packages (WPs) and aims to develop and test disseminable and cost-effective treatments to optimise management for people with AN across all stages of illness. Methods WP1a used surveys, focus groups and a pre–post trial to develop and evaluate a training programme for school staff on eating disorders (EDs). WP1b used a randomised controlled trial (RCT) [International Standard Randomised Controlled Trial Number (ISRCTN) 42594993] to evaluate a prevention programme for EDs in schools. WP2a evaluated an inpatient treatment for AN using case reports, interviews and a quasi-experimental trial. WP2b used a RCT (ISRCTN67720902) to evaluate two outpatient psychological therapies for AN. WP3 used a RCT (ISRCTN06149665) to evaluate an intervention for carers of inpatients with AN. WP4 used actimetry, self-report and endocrine assessment to examine physical activity (PA) in AN. WP5 conducted a RCT (ISRCTN18274621) of an e-mail-guided relapse prevention programme for inpatients with AN. WP6 analysed cohort data to examine the effects of maternal EDs on fertility and their children’s diet and growth. WP7a examined clinical case notes to explore how access to specialist ED services affects care pathways and user experiences. Finally, WP7b used data from this programme and the British Cohort Study (1970) to identify the costs of services used by people with AN and to estimate annual costs of AN for England. Results WP1a: a brief training programme improved knowledge, attitudes and confidence of school staff in managing EDs in school. WP1b: a teacher-delivered intervention was feasible and improved risk factors for EDs in adolescent girls. WP2a: both psychological therapies improved outcomes in outpatients with AN similarly, but patients preferred one of the treatments. WP2b: the inpatient treatment (Cognitive Remediation and Emotional Skills Training) was acceptable with perceived benefits by patients, but showed no benefits compared with treatment as usual (TAU). WP3: compared with TAU, the carer intervention improved a range of patient and carer outcomes, including carer burden and patient ED symptomatology. WP4: drive to exercise is tied to ED pathology and a desire to improve mood in AN patients. PA was not increased in these patients. WP5: compared with TAU, the e-mail-guided relapse prevention programme resulted in higher body mass index and lower distress in patients at 12 months after discharge. WP6: women with an ED had impaired fertility and their children had altered dietary and growth patterns compared with the children of women without an ED. WP7a: direct access to specialist ED services was associated with higher referral rates, lower admission rates, greater consistency of care and user satisfaction. WP7b: the annual costs of AN in England are estimated at between £45M and £230M for 2011. Conclusions This programme has produced evidence to inform future intervention development and has developed interventions that can be disseminated to improve outcomes for individuals with AN. Directions for future research include RCTs with longer-term outcomes and sufficient power to examine mediators and moderators of change. Trial registration Current Controlled Trials ISRCTN42594993, ISRCTN67720902, ISRCTN06149665 and ISRCTN18274621

    Regulation of transcription from the hepatitis B virus major surface antigen promoter by the Sp1 transcription factor

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    The DNA-binding proteins which recognize the regulatory sequence elements of the hepatitis B virus (HBV) major surface antigen promoter were examined by gel retardation analysis, using nuclear extracts from the human hepatoma cell line Huh7. Using this assay, we identified four regions (B, D, E, and F) of the promoter that interact with the same or similar transcription factor(s). In addition, the recognition sequence for the Sp1 transcription factor bound the same or similar transcription factor(s) present in Huh7 cell nuclear extracts, and this binding was inhibited by the four major surface antigen promoter elements, B, D, E, and F. Purified Sp1 transcription factor was shown to bind to three (B, D, and F) of the major surface antigen promoter regulatory sequence elements by DNase I footprinting. Using transient transfection assays with Drosophila Schneider line 2 cells, we found that transcription from the major surface antigen promoter was transactivated by exogenously expressed Sp1, whereas transcription from the other three HBV promoters was not. Deletion analysis of the major surface antigen promoter demonstrated that the promoter region between -35 and +157 was sufficient to confer Sp1 responsiveness. This promoter region includes one of the regulatory elements footprinted by the purified Sp1 transcription factor. The function of the B, D, E, and F promoter elements was further examined by using these binding sites cloned into a minimal promoter element. Each of these regulatory regions transactivated transcription from the minimal promoter element in response to exogenously expressed Sp1. This finding demonstrates that the HBV major surface antigen promoter contains four functional Sp1 binding sites which probably contribute to the level of expression from this promoter during viral infection.</jats:p

    Direct quantification of the translocation activities of Saccharomyces cerevisiae Pif1 helicase

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    10.1093/nar/gkz541Nucleic acids research47147494-750
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