Effects of conventional mechanical ventilation with low tidal volume on the expression of growth factors and inflammatory mediators in developing porcine lungs / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of conventional mechanical ventilation (CMV) with low tidal volume on developmental porcine lungs by examining the expression of growth factors and inflammatory mediators.</p><p><b>METHODS</b>Twelve preterm piglets born at 99 days of gestational age, 12 term neonatal piglets and 11 young piglets (4-5-weeks old) were randomly placed on CMV or were not ventilated (control group). The ventilator settings were adjusted to provide a tidal volume of 6-8 mL/kg in order to maintain a normal blood-gas value. After 6 hrs (preterm piglets) or 24 hrs (neonatal and young piglets) of mechanical ventilation, the mRNA expression of growth factors PDGF-B, IGF-I, KGF, HGF, VEGF and TGF-beta1 and proinflammatory cytokines IL-1beta, IL-6, IL-8 and TNF-alpha in the lung tissue was measured using RT-PCR. Growth factor protein expression was measured with immunohistochemistry.</p><p><b>RESULTS</b>In preterm piglets, the CMV group had increased mRNA expression of PDGF-B (5.11+/-0.10 vs 4.88+/-0.01), IL-1beta (4.95+/-0.27 vs 4.08+/-0.37), IL-6 (4.76+/-0.27 vs 4.00+/-0.28) and IL-8 (5.31+/-0.57 vs 4.15+/-0.46), but decreased IGF-I mRNA expression (3.54+/-0.13 vs 3.80+/-0.11) compared with those in the control group (P<0.05 or 0.01). In term neonatal piglets and young piglets, there were no significant differences in the mRNA expression of growth factors and proinflammatory cytokines between the CMV and control groups.</p><p><b>CONCLUSIONS</b>CMV caused inflammatory injury in immature lungs by increasing the expression of proinflammatory cytokines and PDGF-B and decreasing IGF-I expression. However, CMV had no effects on pulmonary expression of growth factors and inflammatory mediators in term neonatal piglets and young piglets.</p>

Protective effects of allopurinol on white matter damage in premature rats / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of allopurinol (ALLO) on white matter damage in premature rats.</p><p><b>METHODS</b>An animal model for white matter damage was established by bilateral carotid artery occulation (BCAO). Eighty-four newborn SD rats (1 day old) were used in this study and were divided randomly into three groups [sham surgery (Sham); BCAO group (BCAO); allopurinol-treated group (ALLO)]. Pathological changes were studied 7 days and 14 days after BCAO, respectively. Myelin basic protein (MBP) was detected by immunohistochemistry 7 days and 14 days after BCAO, respectively. MBP-mRNA expression was determined 7 days and 14 days after BCAO respectively by reverse transcription-polymerase chain reaction (RT-PCR) with fluorescent quantitative method.</p><p><b>RESULTS</b>In BCAO group, mild or severe rarefaction was found in 10 cases in the corpus callosum area, especially at the cingulum. Pathological changes of white matter were found in 4 cases in internal capsule. Subcortex white matter rarefaction was found in 8 cases. The extent of white matter rarefaction in ALLO group was reduced significantly. Enlargement of bilateral ventricles was found in 6 of 8 cases in BCAO group. The average ventricle size in ALLO group (2.44 +/- 0.71)% was reduced significantly as compared with that in BCAO group (3.27 +/- 0.73)% (P < 0.05). Strong MBP positive staining was found in sub-cortex, corpus callosum, hippocampus gyrus, and internal capsule of P14 sham surgery group. In BCAO group the MBP staining extent was reduced. The extent of MBP staining of ALLO group was between the other two groups. The optical density (OD) of MBP positive staining in BCAO group (6.60 +/- 0.68) was found higher than that in sham surgery group (9.40 +/- 0.53), the difference was statistically significant (P < 0.05). Compared with BCAO group, OD value in ALLO group (7.10 +/- 0.18) increased significantly (P < 0.05). RT-PCR data showed that MBP-mRNA copies (log10) in P7 and P14 rats of both BCAO and ALLO groups were lower than that in sham surgery group (P < 0.01); However, MBP-mRNA copies in ALLO group were higher than that in BCAO group (P < 0.05).</p><p><b>CONCLUSIONS</b>BCAO could be used in newborn rats (1 day old) to establish a premature white matter damage (WMD) animal model. Allopurinol may have a potential protective effect on premature SD rat with ischemic WMD.</p>