大鼠腹腔肥大细胞脱颗粒过程中磷脂酶D活性的变化

AIM: To study the changes of phospholipase D (PLD) activity of actively sensitized rat peritoneal mast cells (RPMC) in degranulation. METHODS: Degranulation of RPMC was determined by measurement of β-hexosaminidase release. PLD activity assay was carried out by measurement of PLD product, choline, with chemiluminescent oxidation of luminol. RESULTS: Actively sensitized RPMC challenged with ovalbumin (0.5-8 mg/L for 120 s, 4 mg/L for 15-120 s) resulted in significant activation of PLD accompanied with the increment of β-hexosaminidase release. PLD activity of sensitized RPMC was increased by more than 2-fold compared with that of unsensitized RPMC which contained low levels of PLD activity [(35+ 13) pmol choline/min in 1 x 106cells], but β-hexosaminidase releases of the sensitized cells were as low as spontaneous releases. After challenge with ovalbumin 4 mg/L for 120 s, PLD activity of sensitized RPMC was increased to (155+43) pmol choline/min in lx 106cells and β-hexosaminidase release was also elevated significantly (4.5-fold of spontaneous release, n=6, P＜0.05). When unsensitized RPMC were stimulated with antigen, PLD activity and β-hexosaminidase release of the cells were hardly changed.Sensitized RPMC were treated with 1% 1-butanol or 2,3- disphosphoglycerate l0 mmol/L before challenge with ovalbumin, these drugs induced an inhibition of PLD activity and a reduction of β-hexosaminidase release to basal level. 1-Butanol 0.1% also worked. CONCLUSION: Phospholipase D plays an important role in the regulation of β-hexosaminidase release in actively sensitized rat peritoneal mast cells.

Background: This study aimed to assess trends in gender differentials in child immunization beyond the conventional male-female dichotomy, by considering gender, surviving siblings, birth order and different compositions of older siblings in tandem, during 1990- 2007 in India and Pakistan.
Methods: Using different rounds of Demographic and Health Survey datasets, we adopted the World Health Organization guidelines for appraising full immunization among children. Sex composition of surviving older siblings was combined. Cochrane-Armitage and the Chisquare tests were used to test linear and nonlinear trends, respectively.
Results: Although child immunization has increased during the period of 1990-2007 in both India and Pakistan, results showed that more than 50% of the eligible children did not receive the recommended immunization. The results also showed that boys and girls with no older surviving siblings and those with only surviving siblings of the opposite sex appeared to have fully immunized proportionally compared with the children with other sibling compositions.
Conclusion: The findings confirmed that girls and boys were not always treated equally, and that there was a clear pattern of selective neglect in child immunization in both countries during the period of 1990-2007.