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ObjectiveThis meta-analysis aimed to investigate the efficacy and safety of plastic wrap applied after birth and during NICU in preterm infants for prevention of heat loss in preterm infants.Study MethodsThe Medline (1950 to August 2015), the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 7, 2015), CINAHL (1982 to August 2015) and the Embase (1974 to August 2015) databases were searched for randomized controlled trials (RCTs) or quasi-RCTs with main outcomes related to the core temperature (baseline temperature and/or post-stabilization temperature), hypothermia, mortality rate and hyperthermia.ResultThe included studies were of low to moderate quality. Compared with unwrapped infants, plastic wrap was associated with a significantly higher baseline temperature and post-stabilization temperature both in infants < 28 weeks of gestation (mean difference [MD] = 0.62, 95% CI 0.38 to 0.85; MD = 0.41, 95% CI 0.33 to 0.50, respectively), and in infants between 28 to 34 weeks of gestation (MD = 0.54, 95% CI 0.21 to 0.87; MD = 0.64, 95% CI 0.45 to 0.82, respectively). Use of plastic wrap was associated with lower incidence of hypothermia (relative risk [RR] = 0.70, 95% CI 0.63 to 0.78). However, use of plastic wrap in preterm infants was not associated with decrease in mortality (RR: 0.88, 95% CI 0.70 to 1.12, P = 0.31). Incidence of hyperthermia was significantly higher in the plastic wrap group as compared to that in the control group (RR = 2.55, 95% CI: 1.56 to 4.15, P = 0.0002). Hyperthermia in the plastic wrap group was resolved within one or two hours after unwrapping the babies.ConclusionPlastic wrap can be considered an effective and safe additional intervention to prevent hypothermia in preterm infants. However, its cost-effectiveness and long-term effect on mortality needs to be ascertained by conducting well-designed studies with longer follow-up period.

The present study was carried out to observe the protective effects of αB-crystallin protein on hydrogen peroxide (H2O2)-induced injury in rat myocardial cells (H9c2) and to investigate the mechanisms of these protective effects at the cellular level, which could provide the experimental basis for future applications of αB-crystallin in the treatment of cardiovascular disease. Western blotting was used to measure the expression of αB-crystallin in cultured H9c2 cells in vitro. A αB-crystallin recombinant expression vector, pcDNA3.1-Cryab, was constructed to transfect H9c2 cells for the establishment of cells that stably expressed αB-crystallin. A tetrazolium-based colorimetric assay (MTT test) was used to measure changes in the viability of the H9c2 cells at 1, 2, 3 and 4 h after induced by 150 μM H2O2 to establish a model of H2O2 injury to cells. H2O2 was applied to H9c2 cells that were stably transfected with αB-crystallin, and the effect of αB-crystallin overexpression on the viability of myocardial cells subjected to H2O2-induced injury was measured by the MTT assay. The effect of αB-crystallin overexpression on the H2O2-induced injury of H9c2 cells was also analyzed by flow cytometry. The mitochondrial components and cytoplasmic components of H9c2 cells were separated, and western blotting was used to measure the effect of αB-crystallin overexpression on the release of cytochrome c from the mitochondria. Western blotting was also used to measure the effect of αB-crystallin overexpression on the expression of the anti-apoptosis protein Bcl-2 and components of the phosphatidylinositol 3-OH kinase (PI3K)/AKT pathway. The αB-crystallin recombinant expression vector pcDNA3.1-Cryab successfully transfected H9c2 cells, and H9c2 cells that were stably transfected with αB-crystallin were established after G418 selection. The measurements carried out by western blotting showed that αB-crystallin proteins are expressed in normal H9c2 cells, but the proteins' expression was much higher in pcDNA3.1-Cryab transfected cells (P < 0.01). The MTT assays showed that 4 h of H2O2 treatment induced significant injury in H9c2 cells (P < 0.01), but αB-crystallin overexpression can effectively antagonize the H2O2-induced injury to H9c2 cells (P < 0.05). The results of flow cytometry analysis showed that αB-crystallin overexpression can significantly reduce apoptosis in H2O2-injured H9c2 cells (P < 0.05). The results of western blotting showed that αB-crystallin overexpression in myocardial cells can reduce the H2O2-induced release of cytochrome c from the mitochondria (P < 0.05), antagonize the H2O2-induced downregulation of Bcl-2 (P < 0.05) and magnify the decrease in phosphorylated AKT levels induced by H2O2 injury (P < 0.05). The overexpression of αB-crystallin has a protective effect on H2O2-injured H9c2 cells, and αB-crystallin can play a protective role by reducing apoptosis, reducing the release of cytochrome c from the mitochondria and antagonizing the downregulation of Bcl-2 expression. The protective effects of αB-crystall...