| 1. |
- BLENNOW, M, et al.
(författare)
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Monoamine neurotransmitters and metabolites in the cerebrospinal fluid following perinatal asphyxia
- 1995
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 67:6, s. 407-413
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Tidskriftsartikel (refereegranskat)abstract
- While the release of neurotransmitters is involved in the pathophysiology of brain damage following birth asphyxia, it also plays a role in endogenous defense against such damage. Levels of monoamines and the main cerebral monoamine metabolites in the cerebrospinal fluid (CSF) were measured in asphyxiated and control infants within 24 h after birth. The results indicate an increased turnover of noradrenaline (NA) and dopamine following asphyxia. Furthermore, the NA stores in the brain seem to be exhausted in some cases. We conclude that this increase in catecholamine turnover to some extent explains the clinical symptoms of hypoxic-ischemic encephalopathy and that it may reflect an intrinsic adaptive capacity to perinatal distress.
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| 2. |
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| 3. |
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| 4. |
- Huang, QW, et al.
(författare)
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Effects of inhaled nitric oxide and high-frequency ventilation in rabbits with meconium aspiration
- 1999
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 76:6, s. 374-382
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To evaluate effects of inhaled nitric oxide (iNO) in experimental meconium aspiration treated with high-frequency (HFV) or conventional mechanical ventilation (CMV). Ventilated adult rabbits had meconium instilled intratracheally resulting in respiratory failure as evidenced by more than 50% reduction of dynamic lung compliance (Cdyn) and increase in mean oxygenation index (OI) from 1 to 16. The animals were then allocated to 2 groups treated without (control) or with iNO at 20 ppm (NO). In each group the animals were initially ventilated with CMV or HFV mode for 3 h and then in a crossover fashion with HFV or CMV for another 3 h (CMV→HFV, HFV→CMV), respectively. In the first 3 h of treatment, the animals subjected to HFV-CMV in the control, and those with both HFV-CMV and CMV-HFV in the NO group had significantly reduced OI. In the subsequent 3 h, the animals in the control group with CMV-HFV did not improve in OI and those with HFV-CMV had deteriorated. In the NO group with both CMV-HFV and HFV-CMV moderate improvement of OI was observed. Platelet aggregation capability and counts were significantly decreased and bleeding time prolonged in animals receiving iNO treatment. These results suggest that both HFV alone and a combined treatment of iNO with either CMV or HFV are more effective in improving blood oxygenation than that of CMV in this animal model. The influence of iNO on platelet aggregation should be considered.
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| 5. |
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| 6. |
- Johansson, J, et al.
(författare)
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Synthetic surfactant protein analogues
- 1998
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 7474 Suppl 1, s. 9-14
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Tidskriftsartikel (refereegranskat)abstract
- Surfactant preparations for the treatment of respiratory distress syndrome (RDS) that contain phospholipids and small amounts of the two hydrophobic proteins, SP-B and SP-C, are presently obtained from animal lungs. Since structural information about SP-B and SP-C is available, it appears possible to design analogues that can replace the native proteins in synthetic surfactants. SP-C contains a single helix, but analogues with the poly-Val sequence of the native molecule do not fold into a native-like α-helical conformation. However, replacement of all Val with Leu yields efficient folding into a helical structure and Leu-based SP-C analogues effectively accelerate spreading of surfactant lipids and exhibit some physiological activity in animal models of RDS. The inferior in vivo activity of synthetic surfactants containing SP-C only compared to that of surfactant preparations derived from natural sources may be caused by a lack of covalently linked palmitoyl groups in the analogues and/or absence of SP-B. SP-B is significantly larger than SP-C and has a tertiary fold of several amphipathic helices in a dimeric structure. A single simplified amphipathic helical peptide containing only Leu and Lys does not mimic the surface properties of SP-B in vitro. These circumstances make the design of SP-B analogues from solely structural considerations less likely to be successful than in the case of SP-C.
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| 7. |
- Lothian, C, et al.
(författare)
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Different expression and mobilisation of the complement regulatory proteins CD35, CD55 and CD59 in neonatal and adult neutrophils
- 1997
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 72:1, s. 15-21
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the expression and the N-formyl-methionyl-phenylalanine (fMLP)- and interleukin-8 (IL-8)-induced mobilisation of the complement regulatory proteins CR1 (CD 35), decay-accelerating factor (CD55) and CD59 on neutrophils in neonates and adults. The expression of CD35 on resting neonatal neutrophils was significantly higher than in adults. Both fMLP and IL-8 increased CD35 expression more markedly in adults. CD55 on resting neutrophils in neonates was significantly higher than in adults, but did not further increase upon fMLP stimulation as opposed to adults. The increase in CD59 expression was more pronounced in adult neutrophils and was significantly higher than in neonates after fMLP activation. The addition of the protease inhibitor phenylmethanesulphonyl fluoride during fMLP activation improved the upregulation of CD 3 5 significantly more in neonates, but not CD 55 or CD59. This effect could be replaced by human normal sera. These data demonstrate that differences exist between neonatal and adult neutrophils with respect to the expression and mobilisation of functional receptors related to protection from autologous complement lysis and may indicate differences in the efficiency to circumvent complement-mediated cell damage at the inflammatory site.
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| 8. |
- ROBERTSON, B, et al.
(författare)
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Alveolar-to-vascular leakage of surfactant protein A in ventilated immature newborn rabbits
- 1995
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 68:3, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- We measured alveolar-to-vascular leakage of surfactant protein A (SP-A) in immature newborn rabbits delivered at a gestational age of 27 days. Experimental animals received, via a tracheal cannula, 2 ml/kg of a mixture of modified porcine surfactant (Curosurf, 80 mg/ml) and human recombinant SP-A (4 mg/ml). Littermate controls received the same volume of human SP-A in saline (4 mg/ml). After 30 min of artificial ventilation with a frequency of 40/min and an inspiration time of either 0.75 or 0.45 s, blood was sampled from the right ventricle and the lungs were lavaged. The content of human SP-A in serum and lung lavage fluid was determined with ELISA kits, and the alveolar-to-vascular leak expressed as the quotient of total SP-A in serum and lavage fluid. The leak in control animals amounted to about 2% of SP-A in lung wash and was several times higher in these animals than in those receiving surfactant. The leak was of the same order irrespective of whether the animals were ventilated with long or short inspiration time. We speculate that serum levels of SP-A may reflect the degree of lung injury in various forms of respiratory failure.
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| 9. |
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| 10. |
- Tornhage, CJ, et al.
(författare)
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Plasma somatostatin and cholecystokinin levels in preterm infants during the first day of life
- 1996
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 70:6, s. 311-321
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Tidskriftsartikel (refereegranskat)abstract
- Our knowledge about regulatory gut peptides in preterm infants is scanty. We therefore began a study of plasma somatostatin (SS) and cholecystokinin (CCK) in preterm infants at birth and during the neonatal period. Plasma SS and CCK levels were assessed in 77 mothers and in 91 preterm infants immediately after birth (umbilical cord) and during the first day of life (IF) (n = 69, median age 5 h). The gestational age ranged from 23 to 36 weeks and the birth weight from 460 to 3,350 g. After Sep-Pak C<sub>18</sub> semichromatography of plasma, SS and CCK were analyzed by RIA. Both plasma SS and CCK levels increased significantly during the first hours of life. Plasma SS levels were negatively correlated to gestational age, birth weight and birth length. When the SS-1F levels were adjusted for gestational age in a multivariate analysis there was no independent association with birthweight but a weak association with birth length. Plasma CCK-1F levels were not correlated with any of these variables. Plasma SS-1F levels were lower after cesarean section. Plasma SS and CCK levels during the first day were not correlated to multiple birth, mode of anesthesia, umbilical pH, Apgar score and blood glucose level before first meal.
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