1,894 research outputs found

    Benign Pleomorphic Adenoma of the Soft Palate Metastasizing to the Sphenoid Sinus

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    A benign pleomorphic adenoma is the most common tumor of the salivary glands. This tumor has the potential to metastasize to bone, the head and neck region, visceral organs and skin. Although there a few reports about a benign pleomorphic adenoma metastasizing to the maxillary sinus in the paranasal sinuses, there are no reports about a metastatic benign pleomorphic adenoma in the sphenoid sinus. We report here on a case of a benign pleomorphic adenoma of the soft palate that metastasized to the sphenoid sinus, and we briefly review the relevant clinical literature

    Biosynthesis of phenylpropanoids and their protective effect against heavy metals in nitrogen-fixing black locust (Robinia pseudoacacia)

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    Purpose: To examine the effect of various heavy metals (HMs) on phenylpropanoid pathway compounds in Robinia pseudoacacia.Methods: A series of pot culture experiments were performed to understand how the metabolic profile of phenylpropanoid compounds were affected by various HMs, such as redox-active HMs (AgNO3 and CuCl2), and non-redox-active HMs (HgCl2). Phenylpropanoid compound level was evaluated by high performance liquid chromatography.Results: The total phenylpropanoid level in leaves increased significantly in all the treated groups when compared to that in the untreated group (p < 0.05). However, a significant effect on the total phenylpropanoid levels was only found for redox-active HMs (p < 0.05), whereas non-redox-active HMs showed less accumulation. Chlorogenic acid and rutin were the two major phenylpropanoid compounds found after the plants were subjected to redox and non-redox-active HMs stress. However, when compared to these two compounds, the levels of catechin hydrate, epicatechin, p-coumaric acid, kaempferol, and quercetin were lower. Caffeic acid level was significantly decreased in both redox and non-redox-active HMs when compared to that in the control (p < 0.05). In addition, trans-cinnamic acid accumulation was altered based on the types and concentration of HMs.Conclusion: Phenylpropanoid metabolic pathway participated in the HM tolerance process for the protection of R. pseudoacacia from oxidative damage caused by HMs, thus allowing the species to grow in highly HMs-contaminated areas. Keywords: Heavy metals, Non-redox-active metals, Phenylpropanoid compounds, Redox-active metals, Robinia pseudoacaci

    Histological confinement of transglutaminase-mediated nit sheath crosslinking is essential for proper oviposition and egg coating in the human head louse, Pediculus humanus capitis

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    Background Head louse females secrete liquid gel, which is mainly composed of the louse nit sheath protein 1 (LNSP1) and LNSP2, when they lay eggs. The gel is crosslinked by transglutaminase (TG) to form the nit sheath, which covers most of the egg except the top operculum area where breathing holes are located. Knowledge on the selective mechanism of nit sheath solidification to avoid uncontrolled crosslinking could lead to designing a novel method of louse control, but no information is available yet. Methods To elucidate the crosslinking mechanisms of nit sheath gel inside the reproductive system of head louse females, in situ hybridization in conjunction with microscopic observation of the oviposition process was conducted. Results Histochemical analysis revealed that LNSP1 and LNSP2 are expressed over the entire area of the accessory gland and uterus, whereas TG expression site is confined to a highly localized area around the opening of posterior oviduct. Detailed microscopic observations of oviposition process uncovered that a mature egg is positioned in the uterus after ovulation. Once aligned inside the uterus, the mature egg is redirected so that its operculum side is tightly held by the ventral end of the uterus being positioned toward the head again and its pointed bottom end being positioned toward the dorsal end of the uterus, which functions as a reservoir for the nit sheath gel. Conclusions Physical separation of the TG-mediated crosslinking site from the ventral end of the uterus is necessary to avoid uncontrolled crosslinking inside the uterus and to ensure selective crosslinking over only the lower part of egg without any unwanted crosslinking over the operculum during oviposition. Graphical Abstrac

    The Effect of Doxycycline on PMA-Induced MUC5B Expression via MMP-9 and p38 in NCI-H292 Cells

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    ObjectivesDoxycycline is commonly used in medicine for its bacteriostatic antimicrobial properties. Recent studies have reported that doxycycline also has anti-inflammatory effects. Matrix metalloproteinase (MMP)-9 has been found to be involved in the physiological and pathological process of inflammatory airway disease. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, is known to stimulate the expression of MMP and mucin genes in the airway and intestinal epithelial cells. Therefore, the effects and signal pathways of doxycycline on PMA-induced MUC5B expression dependent MMP-9 in human airway epithelial cells were investigated.MethodsIn human NCI-H292 airway epithelial cells, MUC5B and MMP-9 mRNA expression, MUC5B protein expression, and MMP-9 protein activity after the treatment with PMA, MMP-9 or doxycycline were determined by reverse transcriptase-polymerase chain reaction, enzyme immunoassay, gelatin zymography, and Western blot analysis.ResultsPMA increased MMP-9 and MUC5B expression. MMP-9 increased MUC5B expression. Doxycycline inhibited PMA-induced MUC5B expression, and PMA-induced MMP-9 mRNA expression and protein activity. Doxycycline inhibited phosphorylation of p38 induced by PMA and MMP-9.ConclusionThe results of this study suggest that doxycycline inhibited PMA-induced MUC5B mRNA expression and protein production through the MMP-9 and p38 pathways in human NCI-H292 airway epithelial cells

    Effect of Epigallocatechin-3-Gallate on PMA-Induced MUC5B Expression in Human Airway Epithelial Cells

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    ObjectivesAmong the inflammatory mediators, phorbol 12-myristate 13-acetate (PMA) is associated with the regulation of MUC5B expression in the airway epithelial cells. Epigallocatechin-3-gallate (EGCG) is the major component of green tea extract. The biological activity of EGCG includes reduction of cholesterol and antioxidant activity, as well as anti-inflammatory effect. However, the precise action mechanism of anti-inflammatory effect of EGCG in the airway epithelial cells has not been fully defined. This study investigates the effect and the brief signaling pathway of EGCG on PMA-induced MUC5B expression in the airway epithelial cells.MethodsIn NCI-H292 airway epithelial cells, the effect and signaling pathway of EGCG on MUC5B expression were investigated using real-time polymerase chain reaction analysis, enzyme immunoassay, immunohistochemical analysis, gelatin zymography assay, and immunoblot analysis.ResultsIn NCI-H292 airway epithelial cells, PMA induced MUC5B expression, phosphorylation of p38 mitogen-activated protein kinase (MAPK), and matrix metalloproteinase-9 (MMP-9) expression and protein activity. EGCG significantly decreased PMA-induced MUC5B expression, phosphorylation of p38 MAPK, and MMP-9 expression and protein activity. SB203580 (p38 MAPK inhibitor) significantly decreased PMA-induced MMP-9 expression. In addition, SB203580 and MMP-9 I (MMP-9 inhibitor) significantly decreased PMA-induced MUC5B expression.ConclusionThese results suggest that EGCG down-regulates PMA-induced MUC5B expression through the p38 MAPK dependent MMP-9 signaling pathway in human airway epithelial cells
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