Pediatric research
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The nuclear enzyme poly(ADP-ribose) polymerase (PARP) is a key component of molecular mechanisms leading to cell death or survival after an ischemic insult. Oxidative stress damages DNA, and breaks in the DNA strands activate PARP enzyme, leading to poly(ADP-ribosyl)ation of nuclear proteins. In this study, we investigated PARP activation using immunodetection of PAR polymers in the brain of neonatal rat pups subjected to unilateral focal ischemia with reperfusion. ⋯ Pretreatment with 3-aminobenzamide (3-AB, 10 mg/kg) strongly reduced PARP activation and cell death. These data suggest that PARP activation represents, in the immature brain, the early sign of ischemic cell death. This raises the possibility of the use of PARP inhibitors not only immediately postischemia but perhaps also later to reduce ischemic lesion in the MCA territory and its connected structures.
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Determining total energy expenditure (TEE) and its components in children treated with home parenteral nutrition (CHPN) under free-living conditions is an important consideration in the assessment of energy requirements and the maintenance of health. The aim of this study was to assess TEE and physical activity in CHPN. Eleven CHPN (three girls and eight boys; median age, 6.0 y; range, 4.5-15.0 y) were compared with 11 healthy children (three girls and eight boys; median age, 6.0 y, range, 4.5-14.0 y) after pairing for sex, age, and weight. ⋯ Sleeping energy expenditure (SEE), expressed per kilogram of FFM, was significantly greater in the CHPN group (median, 0.15; range, 0.10-0.23 kJ/min/kg FFM versus median, 0.12; range, 0.09-0.21 kJ/min/kg FFM for controls; p < 0.05, Wilcoxon rank test). These findings were explained by the high correlation between the energy flow infused by parenteral nutrition and sleeping energy expenditure (p < 0.05, Spearman test) and also-diet induced thermogenesis (p < 0.05 Spearman test). These results suggest that the energy requirements of children on long-term home parenteral nutrition programs do not differ from controls and that cyclic parenteral nutrition does not interfere with physical activity.
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Cystic fibrosis (CF) patients develop chronic lung infections associated with airway obstruction by viscous and insoluble mucus secretions. Although mucus glycoproteins (mucins) are thought to be responsible for mucus plugs, other glycoconjugate components of airway secretions have not been systematically evaluated. The aim of the present study was to determine whether chondroitin sulfate proteoglycans (CSPG) contribute to the insolubility of CF sputum. ⋯ In vitro mixing experiments showed that mucin in nonpurulent sputa was reduced upon incubation with purulent sputa, presumably because of degradation or a loss of immunoreactive mucin epitopes from leukocyte and/or bacterial enzymes present in purulent sputa. Our results suggest that CSPG contribute more significantly than mucins to the insolubility of purulent tracheobronchial secretions from CF patients. Because purulent sputa from non-CF patients showed a similar pattern, our observations with CF sputa may have wider applicability.
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Several aspects of the central regulation of respiratory control have been investigated on brainstem-spinal cord preparations isolated from newborn rats whose dam was given 0.02% caffeine in water as drinking fluid during the whole period of pregnancy. Analysis of the central respiratory drive estimated by the recording of C4 ventral root activity was correlated to Fos ponto-medullary expression. Under normoxic conditions, preparations obtained from the caffeine-treated group of animals displayed a higher respiratory frequency than observed in the control group (9.2 +/- 0.5 versus 7.2 +/- 0.6 burst/min). ⋯ Under hypoxic conditions, the preparations displayed a typical hypoxic respiratory depression associated with changes in the medullary Fos expression pattern. In addition, the hypoxic respiratory depression is clearly emphasized after in utero exposure to caffeine and coincides with an increased Fos expression in the area postrema and nucleus raphe obscurus, two structures in which it is not increased in the absence of caffeine. Taken together, these results support the idea that in utero caffeine exposure could affect central respiratory control.
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Comparative Study
Positive pressure ventilation with the open lung concept optimizes gas exchange and reduces ventilator-induced lung injury in newborn piglets.
Previous studies demonstrated that high-frequency oscillatory ventilation using the open lung concept (OLC) resulted in superior gas exchange and a reduction in ventilator-induced lung injury (VILI). We hypothesized that these beneficial effects could also be achieved by applying the OLC during positive pressure ventilation. After repeated whole-lung-lavage, newborn piglets were assigned to either OLC positive pressure ventilation (PPV(OLC)), OLC high-frequency oscillatory ventilation (HFOV(OLC)), or conventional positive pressure ventilation (PPV(CON)) and ventilated for 5 h. ⋯ There were no differences between the two OLC groups. We conclude that, in surfactant-depleted newborn piglets, application of the OLC during PPV is feasible and results in superior gas exchange and a reduction in VILI compared with conventional PPV. These beneficial effects are comparable to HFOV.