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Natural Surfactant (natural + surfactant)

Distribution by Scientific Domains
Medical Sciences57%

Selected Abstracts

Natural surfactant combined with beclomethasone decreases oxidative lung injury in the preterm lamb

PEDIATRIC PULMONOLOGY, Issue 12 2009
Carlo Dani MD
Abstract We performed a randomized study in preterm lambs to assess the hypothesis that the treatment with natural surfactant combined with beclomethasone might decrease pulmonary oxidative stress in an animal model of respiratory distress syndrome (RDS). Animals received 200,mg/kg of porcine natural surfactant or 200,mg/kg of natural surfactant combined with 400 or 800,µg/kg of beclomethasone. Lung tissue oxidation was studied by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and non-protein bound iron (NPBI) in bronchial aspirate samples. In addition, lung mechanics was evaluated. TH was lower in the groups treated with surfactant plus 400 or 800,µg/kg of beclomethasone than in the surfactant group; AOPP was lower in the group treated with surfactant plus 800,µg/kg of beclomethasone than in the other groups; NPBI was similar in all groups. Surfactant treatment was followed by a sustained improvement of tidal volume (TV) and airway resistance, while dynamic compliance did not vary. However, the mean airway pressure needed to obtain similar values of TV was lower in the group treated with surfactant plus 800,µg/kg of beclomethasone than in other groups. We concluded that natural surfactant combined with beclomethasone at 800,µg/kg is effective in reducing the oxidative lung stress and improving the respiratory function in an animal model of RDS. Pediatr Pulmonol. 2009; 44:1159,1167. © 2009 Wiley-Liss, Inc. [source]

Effect of natural surfactants released from athabasca oil sands on air holdup in a water column

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2000
Zhiang Zhou
Abstract Natural surfactants released from Athabasca oil sands are a crucial component in water-based bitumen extraction processes. The effect of natural surfactant released from estuarine and marine oil sands on air holdup was investigated using a water column. The air holdup in the resultant supernatant of the conditioned oil sands slurry was found to be much higher than that in de-ionized water. A further increase in air holdup was observed with the supernatant obtained from the oil sands slurry conditioned with caustic. Aging of the ore prior to bitumen extraction caused an increase in air holdup. The presence of small amount of fine solids in the supernatant resulted in a higher air holdup for all the cases studied. The present study shows that the higher air holdup and poorer processibility of marine ores, compared with estuarine ores, could be accounted for by the release of larger amount of surface active species and the presence of more fine clays in the ores. Les surfactants naturels issus de sables pétrolifères d'Athabasca sont une composante essentielle des precédés d'extraction du bitume bases sur l'eau. On a étudié à l'aide d'une colonne à eau l'effet sur la rétention d'air de surfactants naturels de sables pétrolifères de mer et d'estuaire. La rétention d'air des boues de sables pétrolifères conditionnées dans le sumageant qui en résulte s'avère nettement superieure à celle constatée dans l'eau déionisée. Une rétention d'air encore plus grande est observée avec le surnageant issu de boues de sables pétrolifères conditionnées avec de la soude caustique. Le vieillissement des minerals avant l'extraction du bitume entraîne un accroissement de la rétention d'air. La présence d'une petite quantité de fines solides dans le surnageant entraîne une plus grande rétention d'air dans tous les cas étudiés. Cette étude montre que la plus grande rétention d'air et l'aptitude moins favorable à l'exploitation des minerals marins, par rapport aux minerals d'estuaire, peut s'expliquer par la production de plus grandes quantités d'espèces surfactives et la présence d'argiles plus fines dans les minerals. [source]

Randomized trial comparing natural and synthetic surfactant: increased infection rate after natural surfactant?

ACTA PAEDIATRICA, Issue 5 2000
AK Kukkonen
The efficacy of a natural porcine surfactant and a synthetic surfactant were compared in a randomized trial. In three neonatal intensive care units, 228 neonates with respiratory distress and a ratio of arterial to alveolar partial pressure of oxygen <0.22 were randomly assigned to receive either Curosurf 100mgkg,1 or Exosurf Neonatal 5 ml kg,1. After Curosurf, the fraction of inspired oxygen was lower from 15min (0.45 ± 0.22 vs 0.70 ± 0.22, p = 0.0001) to 6 h (0.48 ± 0.26 vs 0.64 ± 0.23,p= 0.0001) and the mean airway pressure was lower at 1 h (8.3 3.2 mmH2O vs 9.4 ± 3.1 mmH2O ,= 0.01). Thereafter the respiratory parameters were similar. The duration of mechanical ventilation (median 6 vs 5 d) and the duration of oxygen supplementation (median 5 vs 4 d) were similar for Curosurf and Exosurf After Curosurf, C-reactive protein value over 40 mg r1 occurred in 45% (vs 12%; RR 3.62, 95%CI 2.12-6.17, p = 0.001), leukopenia in 52% (vs 28%; RR 1.85, 95%CI 1.31-2.61, ,= 0.001) and bacteraemia in 11% (vs 4%; RR3.17, 95%CI 1.05-9.52, p < 0.05). We conclude that when given as rescue therapy Curosurf had no advantage compared with Exosurf in addition to the more effective initial response. Curosurf may increase the risk of infection. [source]

Natural surfactant combined with beclomethasone decreases oxidative lung injury in the preterm lamb

PEDIATRIC PULMONOLOGY, Issue 12 2009
Carlo Dani MD
Abstract We performed a randomized study in preterm lambs to assess the hypothesis that the treatment with natural surfactant combined with beclomethasone might decrease pulmonary oxidative stress in an animal model of respiratory distress syndrome (RDS). Animals received 200,mg/kg of porcine natural surfactant or 200,mg/kg of natural surfactant combined with 400 or 800,µg/kg of beclomethasone. Lung tissue oxidation was studied by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and non-protein bound iron (NPBI) in bronchial aspirate samples. In addition, lung mechanics was evaluated. TH was lower in the groups treated with surfactant plus 400 or 800,µg/kg of beclomethasone than in the surfactant group; AOPP was lower in the group treated with surfactant plus 800,µg/kg of beclomethasone than in the other groups; NPBI was similar in all groups. Surfactant treatment was followed by a sustained improvement of tidal volume (TV) and airway resistance, while dynamic compliance did not vary. However, the mean airway pressure needed to obtain similar values of TV was lower in the group treated with surfactant plus 800,µg/kg of beclomethasone than in other groups. We concluded that natural surfactant combined with beclomethasone at 800,µg/kg is effective in reducing the oxidative lung stress and improving the respiratory function in an animal model of RDS. Pediatr Pulmonol. 2009; 44:1159,1167. © 2009 Wiley-Liss, Inc. [source]

Effect of natural surfactants released from athabasca oil sands on air holdup in a water column

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2000
Zhiang Zhou
Abstract Natural surfactants released from Athabasca oil sands are a crucial component in water-based bitumen extraction processes. The effect of natural surfactant released from estuarine and marine oil sands on air holdup was investigated using a water column. The air holdup in the resultant supernatant of the conditioned oil sands slurry was found to be much higher than that in de-ionized water. A further increase in air holdup was observed with the supernatant obtained from the oil sands slurry conditioned with caustic. Aging of the ore prior to bitumen extraction caused an increase in air holdup. The presence of small amount of fine solids in the supernatant resulted in a higher air holdup for all the cases studied. The present study shows that the higher air holdup and poorer processibility of marine ores, compared with estuarine ores, could be accounted for by the release of larger amount of surface active species and the presence of more fine clays in the ores. Les surfactants naturels issus de sables pétrolifères d'Athabasca sont une composante essentielle des precédés d'extraction du bitume bases sur l'eau. On a étudié à l'aide d'une colonne à eau l'effet sur la rétention d'air de surfactants naturels de sables pétrolifères de mer et d'estuaire. La rétention d'air des boues de sables pétrolifères conditionnées dans le sumageant qui en résulte s'avère nettement superieure à celle constatée dans l'eau déionisée. Une rétention d'air encore plus grande est observée avec le surnageant issu de boues de sables pétrolifères conditionnées avec de la soude caustique. Le vieillissement des minerals avant l'extraction du bitume entraîne un accroissement de la rétention d'air. La présence d'une petite quantité de fines solides dans le surnageant entraîne une plus grande rétention d'air dans tous les cas étudiés. Cette étude montre que la plus grande rétention d'air et l'aptitude moins favorable à l'exploitation des minerals marins, par rapport aux minerals d'estuaire, peut s'expliquer par la production de plus grandes quantités d'espèces surfactives et la présence d'argiles plus fines dans les minerals. [source]