| 1. |
- Artlich, A, et al.
(författare)
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Single breath analysis of endogenous nitric oxide in the newborn
- 2001
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 79:1, s. 21-26
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Tidskriftsartikel (refereegranskat)abstract
- Nitric oxide (NO) is found in the exhaled gas of humans immediately after birth. However, variations of endogenous NO concentration during the breathing cycle have not been studied in newborns. We examined 24 newborns without acute respiratory compromise during spontaneous nasal breathing. Gas was sampled from the tip of a thin nasal catheter placed in the hypopharynx. Endogenous NO concentrations measured by chemiluminescence were assigned to the breathing cycle using synchronized CO<sub>2</sub> recording. Exhaled NO could reproducibly be measured at 1.9 ± 0.2 parts per billion (ppb, mean ± SEM). Autoinhaled nasal NO peaks during regular breathing were 12.0 ± 1.7 ppb and reached intermittent maxima of 52.2 ± 5.8 ppb. During regular breathing 6 infants exhibited sudden decreases of nasal NO peaks to periods with <50% amplitude suggesting transient shortage of autoinhaled nasal NO. We conclude that tidal NO analysis can be used to assess upper and lower airway NO production noninvasively during spontaneous breathing in the newborn.
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| 2. |
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| 3. |
- Li, YH, et al.
(författare)
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Induction of human macrophage vascular endothelial growth factor and intercellular adhesion molecule-1 by Ureaplasma urealyticum and downregulation by steroids
- 2002
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 82:1, s. 22-28
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lung disease (CLD) remains a major cause of morbidity for the prematurely born infant. The pathogenesis of CLD is complex and has not been defined entirely. Infection and lung inflammatory events have been thought to play a key role in the development of CLD. However, the contribution of <i>Ureaplasma urealyticum</i> to the development of CLD is debated and steroids produce some improvement in neonates with this disease. The aim of this study was to investigate if <i>U. urealyticum</i> could stimulate macrophages to produce vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) in vitro, which are potentially associated with both early and later pathological changes in the lung during the development of CLD. In addition, the impact of dexamethasone and budesonide on these processes was examined. We found that <i>U. urealyticum</i> antigen (≧4 × 10<sup>7</sup> color-changing units/ml) stimulated human macrophages (phorbol 12-myristate 13-acetate-differentiated THP-1 cell line) to produce VEGF and soluble ICAM-1 in a dose-dependent manner (p < 0.05) measured by ELISA. Likewise, cell surface ICAM-1 (CD54) measured by flow cytometry was increased after stimulation with <i>U. urealyticum</i>. This effect was attenuated by budesonide and dexamethasone (p < 0.05). The mRNA expressions of VEGF and ICAM-1 detected by a semi-quantitative reverse transcriptase polymerase chain reaction were also induced in response to <i>U. urealyticum</i> and inhibited by the steroids (p < 0.05). The expression of ICAM-1 was reduced by 85.5% when the TNF-α production was neutralized with an anti-TNF-α antibody. Our findings imply that <i>U. urealyticum </i>might be involved in the development of CLD of prematurity.
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| 4. |
- Li, YH, et al.
(författare)
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Inhibition of macrophage proinflammatory cytokine expression by steroids and recombinant IL-10
- 2001
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 80:2, s. 124-132
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lung disease (CLD) of prematurity is a prolonged respiratory failure in very-low-birth-weight neonates. Proinflammatory cytokines have been implicated in the development of CLD. Steroids have been shown to produce some improvement in neonates with this disease. The purpose of this study was to evaluate the downregulation of these proinflammatory cytokines by dexamethasone, budesonide and recombinant IL-10 (rIL-10) in order to elucidate the mechanism of the clinical benefit of steroids in babies. Our results showed that dexamethasone, budesonide and rIL-10 significantly inhibited both IL-6 and TNF-α production in the THP-1 cell line stimulated by lipopolysaccharide and <i>Ureaplasma urealyticum</i> antigen. Similar effects were found in macrophages from tracheobronchial aspirate fluid from newborn infants. In the rat alveolar macrophage cell line, steroids inhibited IL-6 and TNF-α production, while rat rIL-10 did not significantly decrease production. In conclusion, steroids and human rIL-10 were able to downregulate proinflammatory cytokine production, which may explain the beneficial effect of steroids and suggests that rIL-10 could be tried as an anti-inflammatory agent in neonates with a high risk of CLD.
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| 5. |
- Li, YH, et al.
(författare)
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Ureaplasma urealyticum induces apoptosis in human lung epithelial cells and macrophages
- 2002
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 82:3, s. 166-173
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lung disease (CLD) of prematurity remains a significant cause of morbidity among premature infants. It is a multifactorial disorder and characterized by an early increased number of neutrophils and alveolar macrophages, with later architectural epithelial and endothelial cell damage. Recently, apoptosis of type 2 pneumocytes in the lung of preterm neonates with acute and chronic lung disease has been examined and apoptosis of mesenchymal cells was detected in the chronic stage of bronchopulmonary dysplasia. Infection and inflammatory responses in the lungs play important roles. However, the contribution of <i>Ureaplasma urealyticum</i> to the development of CLD is debated. We found that <i>U. urealyticum</i> induced apoptosis in human type II lung epithelial cells (A549 cell line) and macrophages (derived from human monocytic cell line THP-1) by measuring the outer leaflets translocation of phosphatidylserine (flow cytometry analysis and fluorescence microscopy assessment), DNA fragmentation analysis, cell morphology changes such as diminution in cell volume, increased cytoplasmic staining, and nuclear pyknosis (hematoxylin and eosin staining) and viable counting (trypan blue exclusion). Anti-TNF-α monoclonal antibody partially protected the macrophages from undergoing apoptosis after infection with <i>U. urealyticum.</i> Our findings imply that <i>U. urealyticum</i> might be involved in impairing lung structure and host immune response during the development of CLD.
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| 6. |
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| 7. |
- Sandberg, Kenneth, 1945, et al.
(författare)
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N-acetylcysteine administration during the first week of life does not improve lung function in extremely low birth weight infants
- 2004
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126 .- 1421-9727. ; 86:4, s. 275-9
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen toxicity is thought to be an important factor involved in development of bronchopulmonary dysplasia (BPD) in the very preterm infant. Glutathione (GSH) plays a major role in the antioxidant defense system in the preterm lung and there are theoretical implications that N-acetylcysteine (NAC) treatment could improve its function. The purpose of this study was to investigate whether NAC treatment during the first week of life to preterm infants improved neonatal lung function as a measure of lung injury. The study was part of a multi-center Nordic controlled trial with prophylactic intravenous NAC treatment (16-32 mg/kg/day) for 6 days in newborn infants with birth weights 500-999 g. Lung mechanics, with calculations of compliance and resistance of the respiratory system, together with measurements of functional residual capacity and indices of gas mixing efficiency in the lung, were performed in 33 preterm infants (18 received NAC and 15 placebo) before discharge from the NICU. Median (range) gestational age was 25 (24-28) weeks in the NAC-treated infants and 25 (24-29) in the placebo group. Corresponding mean (SD) birth weights were 0.774 (0.11) and 0.761 (0.12) kg respectively. Lung function measurements did not show any significant differences between NAC-treated infants compared to placebo when examined before discharge from the NICU. We conclude that prophylactic NAC treatment to extremely low birth weight infants during the first week of life does not improve lung function at term.
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| 8. |
- Sohlstrom, A, et al.
(författare)
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Effects of oxytocin treatment in early life on body weight and corticosterone in adult offspring from ad libitum-fed and food-restricted rats
- 2000
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Ingår i: Biology of the Neonate. - : S. Karger AG. - 0006-3126 .- 1421-9727. ; 78:1, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were: (1) to assess the effects of maternal undernutrition during pregnancy on adult offspring with regard to growth, body composition and plasma levels of glucose, insulin and corticosterone, and (2) to investigate whether oxytocin treatment early in life could ameliorate the adverse effects of food restriction in utero. Pups from ad libitum-fed and food-restricted (60% of ad libitum intake during pregnancy) rats were injected subcutaneously once a day with oxytocin or saline on days 1-14 after birth. At adult age (62 days), male offspring from food-restricted darns had lower body weight, less adipose tissue, lower plasma glucose but higher corticosterone levels, compared to offspring from ad libitum-fed dams. However, oxytocin-treated food-restricted males had higher body weight, higher glucose and lower corticosterone levels compared to their saline-treated counterparts. In conclusion, oxytocin treatment early in life seems to ameliorate some of the adverse effects of food restriction in utero. Copyright (C) 2000 S. Karger AG, Basel.
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| 9. |
- Sohlström, Annica, 1959-, et al.
(författare)
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Oxytocin treatment during early life influences reproductive performance in ad libitum fed and food-restricted female rats
- 2002
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Ingår i: Biology of the Neonate. - : S. Karger AG. - 0006-3126 .- 1421-9727. ; 81:2, s. 132-138
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Tidskriftsartikel (refereegranskat)abstract
- Oxytocin treatment may permanently alter endocrine axes resulting in anti-stress and anabolic effects. However, the nutritional status influences the effects of oxytocin. The specific aims of this study were to investigate the effects of postnatal oxytocin treatment on reproductive performance in adult life, by studying maternal weight gain, adiposity, plasma levels of IGF-I as well as fetal and placental weights in the following groups of animals: (1) Ad libitum fed dams coming from ad libitum fed mothers. (2) Ad libitum fed dams coming from food-restricted mothers. (3) Food-restricted dams coming from ad libitum fed mothers. (4) Food-restricted dams coming from food-restricted mothers. Oxytocin treatment postnatally had long-term effects and increased adiposity in pregnant dams and stimulated placental and fetal growth relative to saline-treated dams. However, if the dams themselves had been exposed to food restriction during fetal life, the effect of postnatal oxytocin treatment changed. The oxytocin-treated mothers were still fatter but had smaller fetuses. In conclusion, postnatal oxytocin treatment influences reproductive performance in later life but is dependent on the mother’s previous and current nutritional experience.
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| 10. |
- Tashiro, K, et al.
(författare)
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Modified protocols for surfactant therapy in experimental meconium aspiration syndrome
- 2003
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 83:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- In adult rats with experimental meconium aspiration syndrome, we investigated whether the therapeutic effect of exogenous surfactant was increased by addition of dextran or preceding airway lavage with diluted surfactant. Animals (n = 72) ventilated with pure oxygen were given human meconium suspension (50–75 mg kg<sup>–1</sup>) through the airways. When the PaO<sub>2</sub> had decreased to <20 kPa (mean ± SD 12 ± 3.9 kPa), the rats were randomly allocated to ten groups (G). G 6–10 underwent lung lavage with diluted Curosurf (5 mg ml<sup>–1</sup>, 20 ml kg<sup>–1</sup>), whereas G 1–5 did not. G 1 and 6 received no additional material through the airways. G 2 and 7 received Curosurf (100 mg kg<sup>–1</sup>), and G 3 and 8 received Curosurf (100 mg kg<sup>–1</sup>) plus dextran (75 mg kg<sup>–1</sup>); G 4 and 9 received Curosurf (200 mg kg<sup>–1</sup>), and G 5 and G 10 received Curosurf (200 mg kg<sup>–1</sup>) plus dextran (75 mg kg<sup>–1</sup>). All rats in G 1 died before 180 min after randomization. In G 2, 3, 6, 7, and 8, the PaO<sub>2</sub> transiently increased to 30–40 kPa. In G 4, 5, 9, and 10, the PaO<sub>2</sub> remained >30 kPa for 180 min. Both airway lavage and supplementation with dextran improved the therapeutic effects of surfactant; however, a large dose (200 mg kg<sup>–1</sup>) was nevertheless required to optimize gas exchange.
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