51 research outputs found

    Completeness and timeliness of tuberculosis notification in Taiwan

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    Tuberculosis (TB) is a notifiable disease by the Communicable Disease Control Law in Taiwan. Several measures have been undertaken to improve reporting of TB but the completeness and timeliness of TB notification in Taiwan has not yet been systemically evaluated

    Transforming Growth Factor-ฮฒ1 Suppresses Hepatitis B Virus Replication by the Reduction of Hepatocyte Nuclear Factor-4ฮฑ 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-ฮฒ1) could effectively suppress HBV replication at physiological concentrations. Here, we provide more evidence that TGF-ฮฒ1 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-4ฮฑ) binding element(s) within the HBV core promoter region was characterized to be responsive for the inhibitory effect of TGF-ฮฒ1 on HBV regulation. Furthermore, we found that TGF-ฮฒ1 treatment significantly repressed HNF-4ฮฑ expression at both mRNA and protein levels. We demonstrated that RNAi-mediated depletion of HNF-4ฮฑ was sufficient to reduce HBc synthesis as TGF-ฮฒ1 did. Prevention of HNF-4ฮฑ degradation by treating with proteasome inhibitor MG132 also prevented the inhibitory effect of TGF-ฮฒ1. Finally, we confirmed that HBV replication could be rescued by ectopic expression of HNF-4ฮฑ in TGF-ฮฒ1-treated cells. Our data clarify the mechanism by which TGF-ฮฒ1 suppresses HBV replication, primarily through modulating the expression of HNF-4ฮฑ gene

    The elements of human cyclin D1 promoter and regulation involved

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    Cyclin D1 is a cell cycle machine, a sensor of extracellular signals and plays an important role in G1-S phase progression. The human cyclin D1 promoter contains multiple transcription factor binding sites such as AP-1, NF-า›B, E2F, Oct-1, and so on. The extracellular signals functions through the signal transduction pathways converging at the binding sites to active or inhibit the promoter activity and regulate the cell cycle progression. Different signal transduction pathways regulate the promoter at different time to get the correct cell cycle switch. Disorder regulation or special extracellular stimuli can result in cell cycle out of control through the promoter activity regulation. Epigenetic modifications such as DNA methylation and histone acetylation may involved in cyclin D1 transcriptional regulation
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