DNA methylation of the allergy regulatory gene interferon gamma varies by age, sex, and tissue type in asthmatics

Background Asthma is associated with allergic sensitization in about half of all cases, and asthma phenotypes can vary by age and sex. DNA methylation in the promoter of the allergy regulatory gene interferon gamma (IFNγ) has been linked to the maintenance of allergic immune function in human cell and mouse models. We hypothesized that IFNγ promoter methylation at two well-studied, key cytosine phosphate guanine (CpG) sites (-186 and -54), may differ by age, sex, and airway versus systemic tissue in a cohort of 74 allergic asthmatics. Results After sampling buccal cells, a surrogate for airway epithelial cells, and CD4+ lymphocytes, we found that CD4+ lymphocyte methylation was significantly higher in children compared to adults at both CpG sites (P <0.01). Buccal cell methylation was significantly higher in children at CpG -186 (P = 0.03) but not CpG -54 (P = 0.66). Methylation was higher in males compared to females at both CpG sites in CD4+ lymphocytes (-186: P <0.01, -54: P = 0.02) but not buccal cells (-186: P = 0.14, -54: P = 0.60). In addition, methylation was lower in CD4+ lymphocytes compared to buccal cells (P <0.01) and neighboring CpG sites were strongly correlated in CD4+ lymphocytes (r = 0.84, P <0.01) and weakly correlated in buccal cells (r = 0.24, P = 0.04). At CpG -186, there was significant correlation between CD4+ lymphocytes and buccal cells (r = 0.24, P = 0.04) but not at CpG -54 (r = -0.03, P = 0.78). Conclusions These findings highlight significant age, sex, and tissue-related differences in IFNγ promoter methylation that further our understanding of methylation in the allergic asthma pathway and in the application of biomarkers in clinical research

Reaction of Liquid Sulphur Trioxide with Diethyl Ether

1106-110

Physicochemical Studies in Non-aqueous Solvents: Part XVII - Cryoscopic Studies of Some Uni-univalent Electrolytes in Tetra methylurea

438-44

Studies on Chlorosulphites:Part I - Preparation & Structure of N-Alkyl/N-2-Chloroethyl-pyridinium/picolinium Chlorosulphites

41-4

Physico-chemical studies in nonaqueous solvents. Part 13. Thermochemical studies of some 1:1 electrolytes in tetramethylurea

Heats of solution of alkali metal, ammonium and substituted ammonium perchlorates, lithium and sodium bromides and sodium and potassium thiocyanates have been measured in the concentration range 1.75-67.7×10−3 mol dm−3 in tetramethylurea (TMU) at 26.9°C. Slopes of the linear plots of heat of solution against square root of concentration of the electrolytes (except for NaClO4 and KSCN) are 2 to 9 times higher than the theoretical limiting slope, suggesting thereby slight association of these electrolytes in TMU. However, the experimental slopes of the plots of NaClO4 and KSCN are comparable to the theoretical plot, showing complete dissociation of these electrolytes. Ion solvation enthalpies have been computed using a modified Buckingham's model. The results indicate that ion solvation enthalpies decrease with the increase in the size of the ions, which is consistent with findings in other solvents

Effects of Asymptomatic Proximal and Distal Gastroesophageal Reflux on Asthma Severity

Rationale: Silent gastroesophageal reflux (GER) is common in patients with asthma, but it is unclear whether GER is associated with worse asthma symptoms or reduced lung function