Effect of L-alanyl-L-glutamine on expression of insulin-like growth factor-1 in intestinal tissues of low-birth-weight newborn rats with hypoxia/reoxygenation-induced intestinal injury / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of L-alanyl-L-glutamine (Ala-Gln) on the levels of insulin-like growth factor-1 (IGF-1) and IGF-1 receptor (IGF-1R) in the intestinal tissues of low-birth-weight (LBW) newborn rats with hypoxia/reoxygenation-induced intestinal injury.</p><p><b>METHODS</b>Pregnant rats were fed with or without smoking. The rats born by those fed without smoking were included in group A; for the rats born by those fed with smoking, normal-birth-weight rats were included in group B, and LBW rats were randomly divided into control group (group C), hypoxia/reoxygenation (H/R) group (group D), and Ala-Gln group (group E). Each group consisted of 24 newborn rats. The rats in groups D and E received H/R treatment twice a day for three consecutive days to establish an intestinal injury model; the rats in group E were intraperitoneally injected with Ala-Gln (10 ml/kg) before daily H/R treatment, while those in groups C and D were given an equal dose of normal saline by intraperitoneal injections. On days 4, 7, and 10 after birth, 8 rats were sacrificed in each group to collect intestinal tissues. The IGF-1 levels in intestinal tissues were measured using ELISA, and IGF-1R levels were measured by immunohistochemistry.</p><p><b>RESULTS</b>There were no significant differences in IGF-1 and IGF-1R levels between groups A and B at all time points. The levels of IGF-1 and IGF-1R in group C kept increasing, were higher than those in other groups on day 7 (P<0.05), and reached a normal level on day 10, without significant differences compared with those in groups A and B. Group D had significantly lower IGF-1 and IGF-1R levels than group C at all time points (P<0.05). The levels of IGF-1 and IGF-1R in group E were lower than those in group C on days 4 and 7 (P<0.05), but they increased to approximately the levels in group C and were significantly higher than those in group D on day 10.</p><p><b>CONCLUSIONS</b>Intrauterine and postnatal hypoxia may induce intestinal injury in LBW newborn rats, and parenteral administration of high-dose Ala-Gln can reduce hypoxia-induced intestinal injury. Therefore, Ala-Gln has a protective effect against hypoxia-induced intestinal injury.</p>

Culture in vitro and lentivirus transfection of rat mesenchymal stem cells / 中国实验血液学杂志

This study was purposed to establish the methods for isolation, culture, identification and labeling of bone marrow mesenchymal stem cells (BMMSC), so as to provide quantified seed cells for cell transplantation. Bone marrow was collected from SD rat by flushing femur and tibias under sterile condition and BMMSC were purified by adherent culture and amplified in vitro. The immunophenotypes of BMMSC were identified by flow cytometry, the ability of differentiation to osteogenic and adipogenic lineages was detected by alizarin red and oil red O respectively. The BMMSC were transfected by using lentivirus with green fluorescence protein (GFP) gene so as to determine GFP expression in BMMSC. The results demonstrated that the method of adherent culture could effectively isolate and purify rat BMMSC which displayed homogenous fibro-like morphology. The flow cytometry showed that BMMSC expressed CD29, CD44, not expressed CD34, CD45. The BMMSC could differentiated into osteoblasts and adipocytes two mesenchymal lineages when grown in specific medium for each lineage. After being transfected by lentivirus, BMMSC could express GFP. It is concluded that the adherent culture is simple, effective, feasible method to separate MSC from the bone marrow of adult rats; the separated and cultured cells exhibit the biological characteristics of BMMSC and differentiating potential. BMMSC can express GFP efficiently and stably in vitro after being transfected by lentivirus, which can be used to label cells for tracing in vivo.

Prophylaxis of neonatal respiratory distress syndrome by intra-amniotic administration of pulmonary surfactant / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neonatal respiratory distress syndrome (NRDS) is caused by a deficiency in pulmonary surfactant (PS) and is one of the main reasons of neonatal mortality. This study was conducted to evaluate the efficacy and safety of intra-amniotic administration of pulmonary surfactant for prophylaxis of NRDS.</p><p><b>METHODS</b>Forty-five pregnant women who were due for preterm delivery and whose fetuses' lungs proved immature were divided into two groups. Fifteen women (study group) were administered one dose of pulmonary surfactant injected into the amniotic cavity and delivered within several hours. Nothing was injected into the amniotic cavity of 30 women of the control group. The proportion of neonatal asphyxia, NRDS, mortality and the time in hospital were analyzed to determine if there was any difference between the two groups.</p><p><b>RESULTS</b>There was no significant difference between the two groups for neonatal asphyxia. Foam tests showed that higher proportion of neonates in the study group than in the control group (56.3% vs 13.3%, P < 0.05) had lung maturity. A greater number of control neonates (11/30, 32.3%) had NRDS, compared with the neonates given PS via the amniotic cavity before delivery (1/16, 6.3%, P < 0.05). The neonates in the study group spent nearly 10 days less in hospital than the control group [(32.4 +/- 7.6) days vs (42.0 +/- 15.7) days, P < 0.05], but the difference in mortality between the two groups was not statistically significant.</p><p><b>CONCLUSIONS</b>Intra-amniotic administration of pulmonary surfactant can significantly reduce the proportion of NRDS and the time in hospital of preterm neonates. Whether this method can reduce the mortality of preterm neonates needs to be evaluated further. Intra-amniotic administration of pulmonary surfactant provides an additional effectual means for NRDS prophylaxis.</p>