13 research outputs found

    Anti-allergic Activity of Stem Bark of Myrica esculenta Buch.-Ham. (Myricaceae)

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    Allergic diseases, such as allergic asthma, are hypersensitivity reactions initiated by immunological mechanisms. Myrica esculenta (M. esculenta) is known traditionally in Ayurveda to possess anti-asthmatic activity. The present investigation was undertaken to evaluate the effect of crude extract of stem bark of M. esculenta (Family Myricaceae, commonly known as Kaiphal) on experimental allergic reactions. Experimental models studied were allergic pleurisy and vascular permeability induced by acetic acid in mice. Pretreatment with M. esculenta (75 mg/kg and 150 mg/kg, p.o.) significantly inhibited the eosinophil accumulation (P < 0.01) respectively in the pleural cavity. M. esculenta (75 and 150 mg/kg, p.o.) significantly inhibited the rise in plasma exudation (57.12% and 59.77%, P < 0.01) induced by acetic acid in mice. These findings demonstrate that the crude extract from the stem bark of M. esculenta possesses antiallergic activity. This activity may be mediated by reducing the release of mediators such as histamine, inhibition of mast cell degranulation, and inhibition of eosinophil accumulation thereby preventing the release of cytokines and chemokines

    The genetic architecture of the human cerebral cortex

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    INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

    Activated memory T helper cells in bronchoalveolar lavage fluid from patients with atopic asthma:relation to asthma symptoms, lung function, and bronchial responsiveness

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    BACKGROUND: Bronchial mucosal inflammation and epithelial damage are characteristic features of asthma. Activation of T helper lymphocytes may contribute to this process by mechanisms including the release of cytokines promoting eosinophil infiltration and activation. METHODS: Bronchial washings and bronchoalveolar lavage fluid were obtained from 29 atopic asthmatic patients (19 with current symptoms and 10 symptom free) and 13 normal volunteers. Flow cytometry was used to assess T cell phenotype and activation status in bronchoalveolar lavage fluid and peripheral blood, and differential cell counts were made on bronchial washings and bronchoalveolar lavage fluid. Findings were related to severity of disease as reflected by symptom scores, baseline lung function, and airway responsiveness. RESULTS: CD4 T lymphocytes in bronchoalveolar lavage fluid and blood from asthmatic patients were activated by comparison with controls (CD4 CD25, median 16.8% v 8.7% for bronchoalveolar lavage fluid, and 15.3% v 8.7% in blood). Bronchoalveolar lavage fluid CD4 T cells from both asthmatic patients and controls were of memory phenotype (95.8% and 96.8% CD45RO and 1.7% and 0.4% CD45RA respectively), whereas both CD45RO and CD45RA T cells were present in blood. Patients with asthma and current symptoms showed increased bronchoalveolar T cell activation compared with patients without symptoms (CD4 CD25 18.7% v 12.3%). Within the asthmatic group there was a significant association between CD4 CD25 lymphocytes and asthma symptom scores (rs = 0.75), airway methacholine responsiveness (log PC20, rs = -0.43) and baseline FEV1 (rs = -0.39). A correlation was also found between CD4 CD25 lymphocytes and eosinophils in bronchoalveolar lavage fluid (rs = 0.48). Eosinophils in bronchoalveolar lavage fluid were increased in asthmatic patients compared with controls and the percentage of eosinophils in bronchoalveolar lavage fluid correlated with asthma symptom score. A relation was found between percentage of epithelial cells in bronchoalveolar lavage fluid and FEV1 and methacholine PC20. CONCLUSION: These results support the hypothesis that selective activation of memory CD4 T cells contributes to eosinophil accumulation, bronchial hyperresponsiveness, and symptoms in asthma

    Cytokines. 3. Cytokines in asthma.

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