AIM:To investigate the effect of exogenous epidermal growth factor(EGF) on expression of EGFR and EGF mRNA of the injuried lung tissue of neonatal premature rats exposed to hyperoxia.METHODS:The neonatal Sprague-Dawley rats of 21-day gestational age model of hyperoxia induced lung injury were made by continually inhaling 95% oxygen.The model rats were divided into two groups randomly,the EGF trail group and the NS control group.The other rats were taken into the air control group.Each group was divided into three subsets:a(1-3 days),b(4-6 days) and c(1-6 days) according to different application times of EGF or NS.Rats in sub groups were executed and the lung tissues were removed at postnatal 3th,7th,14th day respectively.Using immunohistochemistry method,the expression of EGF-R of lung tissues in different groups was observed,and the expression of EGF mRNA was determined by reverse transcriptase polymerase chain reaction(RT-PCR).RESULTS:The expression of EGF mRNA increased by degrees following the increasing postnatal days.Compared with the air control group,the expression of EGF-R and EGF mRNA increased in the hyperxia group at 7th day and 14th day.The expression of EGF-R increased in corresponding hyperxia NS control group at 14th day(P

AIM: To examine the expression of CD69 on NK cells at the fetomaternal interface in CBA/J?DBA/2 mice as a model of recurrent spontaneous abortion (RSA), and to evaluate the effects of lymphocyte immunotherapy (LIT) on the level of CD69 expression and the relationship with the outcomes of murine fetuses and pups. METHODS: The outcomes of murine fetuses and pups were evaluated in breeding pairs of CBA/J?DBA/2, C57BL/6?DBA/2 and BALB/c?DBA/2 mice. Both preweaning growth curves and Kaplan-Meier survival graphs of pups were constructed throughout postnatal days 1 to 21. In addition, the level of CD69 expression on NK cells at the fetomaternal interface with and without LIT were determined by two-color flow cytometric analysis, stained with PE-CD69 and FITC-DX5. The subpopulation of CD16/CD32 + NK cells was also evaluated. RESULTS: Statistically significant differences were observed between CBA/J?DBA/2 mice and normal fertile controls in the median increase of maternal weight during pregnancy, the number of pups born per litter, the median neonatal weight on postnatal day 1, and the resorption rate of fetuses. The proportion of CD69 +DX5 + cells which represents activated NK cells was significantly higher in CBA/J?DBA/2 mice compared with normal fertile controls, while efficient LIT was able to dramatically decrease the expression of CD69 on NK cells at the fetomaternal interface and this was associated with the decrease of resorption rate accordingly. CONCLUSION: The fraction of CD69 +DX5 + cells seems to be functionally important in the mechanisms by which the embryos were rejected, whereas efficient LIT is capable of reducing the abortion rate via decreasing the expression of CD69 molecules on NK cells at the fetomaternal interface.

AIM: To investigate the effect of glycine on endotoxin and hypoxia-induced necrotizing exterocolitos (NEC) in rats. METHODS: In glycine+NEC group, twenty anesthetized and artificially ventilated rats received 1g/kg glycine (20%, iv). Five minutes later, the rats were treated with 2 mg/kg lipopolysaccharide (LPS). In control group (NS+NEC), twenty rats were treated with normal saline as a substitute for glycine. In all animals, FiO 2 was reduced after 90 min from 21% to 5% and ventilation continued until 180 min or death. At the end of the experiment, the samples of blood and intestine were obtained immediately. Serum TNF? was measured with ELISA, serum NO was determined by nitrate reductase. The histopathology of the necrotic lesions were categoried: grade Ⅰ, focal mild injury confined to villous tips; grade Ⅱ, partial loss of villi; grade Ⅲ, necrosis extending to submucosa; grade Ⅳ, transmural necrosis. RESULTS: The survival time [(159 25?22 78) min vs (138 75?19 05) min] was shorter in the NS+NEC group ( P