466 research outputs found

    In Vitro Anti-Cytomegalovirus Activity of Kampo (Japanese Herbal) Medicine

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    We examined the effect of three types of Kampo medicines on human cytomegalovirus (CMV) replication in the human embryonic fibroblast cell line, MRC-5. Treatment of cells with at least 0.01 μg/ml of Kampo medicines inhibited the cytopathic effects of CMV-infected MRC-5 cells. Moreover, Kampo medicine decreased the replication of CMV without affecting the inhibition of host cells, with a concomitant decrease in CMV DNA levels. However, Kampo medicine demonstrated no virocidal effect on cell-free CMV. Furthermore, western blotting analysis demonstrated that the Kampo medicine decreased the amount of 65 kDa late antigen expression in the infected cells. These results suggest that Kampo medicine may be sufficient to inhibit viral DNA replication and late protein synthesis, resulting in anti-CMV effects. Therefore, these three Kampo medicines have the potential of being a source of new powerful anti-CMV compounds

    Accumulation of Uroporphyrin I in Necrotic Tissues of Squamous Cell Carcinoma after Administration of 5-Aminolevulinic Acid

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    5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence is widely used for the intraoperative detection of malignant tumors. However, the fluorescence emission profiles of the accompanying necrotic regions of these tumors have yet to be determined. To address this, we performed fluorescence and high-performance liquid chromatography (HPLC) analyses of necrotic tissues of squamous cancer after 5-ALA administration. In resected human lymph nodes of metastatic squamous cell carcinoma, we found a fluorescence peak at approximately 620 nm in necrotic lesions, which was distinct from the PpIX fluorescence peak at 635 nm for viable cancer lesions. Necrotic lesions obtained from a subcutaneous xenograft model of human B88 oral squamous cancer also emitted the characteristic fluorescence peak at 620 nm after light irradiation: the fluorescence intensity ratio (620 nm/635 nm) increased with the energy of the irradiation light. HPLC analysis revealed a high content ratio of uroporphyrin I (UPI)/total porphyrins in the necrotic cores of murine tumors, indicating that UPI is responsible for the 620 nm peak. UPI accumulation in necrotic tissues after 5-ALA administration was possibly due to the failure of the heme biosynthetic pathway. Taken together, fluorescence imaging of UPI after 5-ALA administration may be applicable for the evaluation of tumor necrosis

    Sweet Taste Receptor Expressed in Pancreatic β-Cells Activates the Calcium and Cyclic AMP Signaling Systems and Stimulates Insulin Secretion

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    BACKGROUND:Sweet taste receptor is expressed in the taste buds and enteroendocrine cells acting as a sugar sensor. We investigated the expression and function of the sweet taste receptor in MIN6 cells and mouse islets. METHODOLOGY/PRINCIPAL FINDINGS:The expression of the sweet taste receptor was determined by RT-PCR and immunohistochemistry. Changes in cytoplasmic Ca(2+) ([Ca(2+)](c)) and cAMP ([cAMP](c)) were monitored in MIN6 cells using fura-2 and Epac1-camps. Activation of protein kinase C was monitored by measuring translocation of MARCKS-GFP. Insulin was measured by radioimmunoassay. mRNA for T1R2, T1R3, and gustducin was expressed in MIN6 cells. In these cells, artificial sweeteners such as sucralose, succharin, and acesulfame-K increased insulin secretion and augmented secretion induced by glucose. Sucralose increased biphasic increase in [Ca(2+)](c). The second sustained phase was blocked by removal of extracellular calcium and addition of nifedipine. An inhibitor of inositol(1, 4, 5)-trisphophate receptor, 2-aminoethoxydiphenyl borate, blocked both phases of [Ca(2+)](c) response. The effect of sucralose on [Ca(2+)](c) was inhibited by gurmarin, an inhibitor of the sweet taste receptor, but not affected by a G(q) inhibitor. Sucralose also induced sustained elevation of [cAMP](c), which was only partially inhibited by removal of extracellular calcium and nifedipine. Finally, mouse islets expressed T1R2 and T1R3, and artificial sweeteners stimulated insulin secretion. CONCLUSIONS:Sweet taste receptor is expressed in beta-cells, and activation of this receptor induces insulin secretion by Ca(2+) and cAMP-dependent mechanisms
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