1,300 research outputs found

    Inhibition of release of vasoactive and inflammatory mediators in airway and vascular tissues and macrophages by a Chinese herbal medicine formula for allergic rhinitis

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    Herbal therapies are being used increasingly for the treatment of allergic rhinitis. The aim of this study was to investigate the possible pharmacological actions and cellular targets of a Chinese herbal formula (RCM-101), which was previously shown to be effective in reducing seasonal allergic rhinitis symptoms in a randomized, placebo-controlled clinical trial. Rat and guinea pig isolated tissues (trachea and aorta) were used to study the effects of RCM-101 on responses to various mediators. Production of leukotriene 134 in porcine neutrophils and of prostaglandin E-2 and nitric oxide (NO) in Raw 264.7 cells were also measured. In rat and guinea pig tracheal preparations, RCM-101 inhibited contractile responses to compound 48/80 but not those to histamine (guinea pig preparations) or serotonin (rat preparations). Contractile responses of guinea pig tracheal preparations to carbachol and leukotriene C-4. and relaxant responses to substance P and prostaglandin E2 were not affected by RCM-101. In rat aortic preparations, precontracted with phenylephrine, endothelium-dependent relaxant responses to acetylcholine and endothelium-independent relaxant responses to sodium nitroprusside were not affected by RCM-101. However, RCM-101 inhibited relaxations to L-arginine in endothelium-denuded rat aortic preparations, which had been pre-incubated with lipopolysaccharide. RCM-101 did not affect leukotriene 134 formation in isolated porcine neutrophils, induced by the calcium ionophore A23187; however, it inhibited prostaglandin E-2 and NO production in lipopolysaccharide-stimulated murine macrophages (Raw 264.7 cells). The findings indicate that RCM-101 may have multiple inhibitory actions on the release and/or synthesis of inflammatory mediators involved in allergic rhinitis

    Inhibition of release of inflammatory in primary and cultured cells by a Chinese herbal medicine formula for allergic rhinitis

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    BACKGROUND - We demonstrated that a Chinese herbal formula, which we refer to as RCM-101, developed from a traditional Chinese medicine formula, reduced nasal and non-nasal symptoms of seasonal allergic rhinitis (SAR). The present study in primary and cultured cells was undertaken to investigate the effects of RCM-101 on the production/release of inflammatory mediators known to be involved in SAR. METHODS - Compound 48/80-induced histamine release was studied in rat peritoneal mast cells. Production of leukotriene B4 induced by the calcium ionophore A23187 was studied in porcine neutrophils using an HPLC assay and lipopolysaccharide-stimulated prostaglandin E2 production was studied in murine macrophage (Raw 264.7) cells by immune-enzyme assay. Expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) was determined in Raw 264.7 cells, using western blotting techniques. RESULTS - RCM-101 (1-100 microg/mL) produced concentration-dependent inhibition of compound 48/80-induced histamine release from rat peritoneal mast cells and of lipopolysaccharide-stimulated prostaglandin E2 release from Raw 264.7 cells. Over the range 1 - 10 microg/mL, it inhibited A23187-induced leukotriene B4 production in porcine neutrophils. In addition, RCM-101 (100 microg/mL) inhibited the expression of COX-2 protein but did not affect that of COX-1. CONCLUSION - The findings indicate that RCM-101 inhibits the release and/or synthesis of histamine, leukotriene B4 and prostaglandin E2 in cultured cells. These interactions of RCM-101 with multiple inflammatory mediators are likely to be related to its ability to reduce symptoms of allergic rhinitis

    Interference estimated time of arrival on a 6-DOF cable-driven haptic foot platform

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    A Cable-Driven Locomotion Interface employs two independent cable-driven haptic foot platforms constrained in six degrees of freedom (6-DOF). Its control system and its geometry are designed for performing a wide range of trajectories that could generate cable interferences. This paper presents and analyzes computational methods for determining which cable can be released from an active actuation state while allowing control in a minimal tension state, thereby ensuring that both platforms stay in a controllable workspace. One challaging task is to develop light and fast computational algorithms for hard real time processes included in haptic display applications. Seeing that releasing a cable from an active actuation state might generate discontinuities in tension values in the other cables, this paper proposes collision prediction schemes named Interference Estimated Time of Arrival in order to reduce or completely eliminate such discontinuities

    Panax ginseng C.A Meyer root extract for moderate Chronic Obstructive Pulmonary Disease (COPD): study protocol for a randomised controlled trial

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    Chronic obstructive pulmonary disease (COPD) impairs quality of life and leads to premature mortality. COPD sufferers experience progressive deterioration of lung function and decreased ability to undertake day-to-day activities. Ginseng has been used for thousands of years in Chinese medicine for respiratory symptoms. Several controlled clinical trials using ginseng for COPD have shown promising clinical effect, however these studies were generally small and with some potential bias, prompting the need for rigorously designed studies

    Inverse lift: a signature of the elasticity of complex fluids?

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    To understand the mechanics of a complex fluid such as a foam we propose a model experiment (a bidimensional flow around an obstacle) for which an external sollicitation is applied, and a local response is measured, simultaneously. We observe that an asymmetric obstacle (cambered airfoil profile) experiences a downards lift, opposite to the lift usually known (in a different context) in aerodynamics. Correlations of velocity, deformations and pressure fields yield a clear explanation of this inverse lift, involving the elasticity of the foam. We argue that such an inverse lift is likely common to complex fluids with elasticity.Comment: 4 pages, 4 figures, revised version, submitted to PR
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