Mast cells participate in allergy and inflammation by secreting inflammatory mediators such as histamine and proinflammatory cytokines. Flavonoids are naturally occurring molecules with antioxidant, cytoprotective, and antiinflammatory actions. However, effect of flavonoids on the release of histamine and proinflammatory mediator, and their comparative mechanism of action in mast cells were not well defined. Here, we compared the effect of six flavonoids (astragalin, fisetin, kaempferol, myricetin, quercetin, and rutin) on the mast cell-mediated allergic inflammation. Fisetin, kaempferol, myricetin, quercetin, and rutin inhibited IgE or phorbol-12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-mediated histamine release in RBL-2H3 cells. These five flavonoids also inhibited elevation of intracellular calcium. Gene expressions and secretion of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and IL-8 were assessed in PMACI-stimulated human mast cells (HMC-1). Fisetin, quercetin, and rutin decreased gene expression and production of all the proinflammatory cytokines after PMACI stimulation. Myricetin attenuated TNF-alpha and IL-6 but not IL-1beta and IL-8. Fisetin, myricetin, and rutin suppressed activation of NF-kappaB indicated by inhibition of nuclear translocation of NF-kappaB, NF-kappaB/DNA binding, and NF-kappaB-dependent gene reporter assay. The pharmacological actions of these flavonoids suggest their potential activity for treatment of allergic inflammatory diseases through the down-regulation of mast cell activation.

Long-term treatment of lamivudine led to significant improvement in the seroconversion rate of HBeAg in children with chronic hepatitis B compared with IFN-alpha therapy. Furthermore, in preschool-age children, it led to significant improvement in the seroconversion rate of HBeAg and HBsAg compared with school-age children.

Background: Bronchiectasis is a chronic pulmonary disease characterized by progressive and irreversible bronchial dilatation. The aim of the present study was to investigate the etiologies and clinical features of bronchiectasis in Korean children. Methods: We performed a retrospective review of the medical records for children diagnosed with bronchiectasis between 2000 and 2017 at 28 secondary or tertiary hospitals in South Korea. Results: A total of 387 cases were enrolled. The mean age at diagnosis was 9.2 ± 5.1 years and 53.5% of the patients were boys. The most common underlying cause of bronchiectasis was preexisting respiratory infection (55.3%), post-infectious bronchiolitis obliterans (14.3%), pulmonary tuberculosis (12.3%), and heart diseases (5.6%). Common initial presenting symptoms included chronic cough (68.0%), recurrent pneumonia (36.4%), fever (31.1%), and dyspnea (19.7%). The most predominantly involved lesions were left lower lobe (53.9%), right lower lobe (47.1%) and right middle lobe (40.2%). No significant difference was observed in the distribution of these involved lesions by etiology. The forced expiratory volume in 1 s (FEV 1 ) levels were lowest in cases with interstitial lung disease-associated bronchiectasis, followed by those with recurrent aspiration and primary immunodeficiency. Conclusions: Bronchiectasis should be strongly considered in children with chronic cough and recurrent pneumonia. Long-term follow-up studies on pediatric bronchiectasis are needed to further clarify the prognosis and reduce the disease burden in these patients.

Background and Objectives: The goal of this study was to assess changes in left ventricular (LV) function and to identify pre-closure factors associated with LV dysfunction {fractional shortening (FS) below 29%} after transcatheter patent ductus arteriosus (PDA) closure. Subjects and Methods: Forty-three pediatric patients with PDAs underwent cardiac catheterization for hemodynamic studies and intervention. Doppler echocardiography was performed at pre-closure, post-closure, and follow-up. Results: S' and A' of the septum and mitral annulus were significantly decreased at post-closure and follow-up, respectively. In five of eight patients with Qp/Qs ratios over 1.60 and Pp/Ps ratios over 0.32 at pre-closure, the FS was decreased below 29% at post-closure. Qp/Qs ratio over 1.60 and Pp/Ps ratio over 0.32 at pre-closure had a sensitivity of 86% and a specificity of 84% for predicting FS to be below 29% at post-closure. Conclusion: Larger amounts of pre-closure left-to-right shunting and higher pulmonary artery pressure were associated with an increased likelihood of FS <29% after closure. The results of this study suggest that serial assessments of ventricular function are needed after PDA occlusion in patients with high Qp/Qs and Pp/Ps ratios.

We found higher levels of cytokines (IFN-α, IL-6, IP-10) of innate immunity than those of acquired immunity in pediatric H1N1 infection. Of the cytokines found to be increased in cases with H1N1 infection, IP-10 and IL-6 were found to be correlated with disease severity (lymphopenia and hypoxia). IP-10 and IL-6 may be important markers in pediatric H1N1 infection.