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Träfflista för sökning "WFRF:(Fellman Vineta) srt2:(2000-2004)"

Sökning: WFRF:(Fellman Vineta) > (2000-2004)

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1.
  • Ahola, T., et al. (författare)
  • Plasma 8-isoprostane is increased in preterm infants who develop bronchopulmonary dysplasia or periventricular leukomalacia
  • 2004
  • Ingår i: Pediatr Res. - 0031-3998. ; 56:1, s. 88-93
  • Tidskriftsartikel (refereegranskat)abstract
    • Our aim was to assess the plasma free 8-epi-prostaglandin F(2alpha) (8-isoprostane) and ascorbyl radical as risk indicators for oxidative damage in extremely low birth weight infants (ELBWIs) and the effect of N-acetylcysteine (NAC) on these markers. Plasma samples were collected on days 3 and 7 of life from infants who were enrolled in a randomized, controlled trial in which i.v. NAC or placebo was administered to ELBWIs during the first week of life, with the aim of preventing bronchopulmonary dysplasia (BPD). Plasma 8-isoprostane was analyzed in 83 infants using an enzyme immunoassay kit. Ascorbyl radical concentration was measured in 61 infants with electron spin resonance spectroscopy. The 8-isoprostane concentrations were similar in the NAC and placebo groups. In infants who later developed BPD or died (n = 29), the median (range) 8-isoprostane concentration was significantly higher (p = 0.001) on day 3 and day 7 [50.0 pg/mL (19-360) and 57.0 pg/mL (14-460), respectively] than in survivors without BPD [n = 54; 34.5 pg/mL (5-240) and 39.5 pg/mL (7-400), respectively]. The 8-isoprostane levels increased significantly more (p < 0.05) in infants who later developed periventricular leukomalacia. NAC treatment or the later development of BPD was not related to the ascorbyl radical levels. The ascorbyl radical level decreased significantly in all groups from day 3 to day 7, but the difference between the groups was not significant. The mean (SD) ascorbyl radical level on day 3 was significantly higher (p < 0.01) in infants who later developed periventricular leukomalacia [287 (124) versus 194 (90)]. These data suggest that plasma 8-isoprostane could serve as a marker in assessing the risk for BPD development in ELBWIs.
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2.
  • Ahola, T, et al. (författare)
  • Thiol metabolism in preterm infants during the first week of life
  • 2004
  • Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 64:7, s. 649-658
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Oxidative stress is implicated in the pathogenesis of several complications of prematurity. The glutathione cycle is one of the most important intracellular antioxidant systems. The synthesis of glutathione may not be adequate in preterm neonates because of the low levels of cysteine available. The aim of this study was to evaluate cysteine and glutathione metabolism during the first week of life in preterm infants. Methods: Plasma and erythrocyte thiol concentrations were measured in 78 preterm infants with a birthweight of 500 1500 g, and erythrocyte glutamate-cysteine ligase (GCL), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferases (GST) and glucose 6-phosphatedehydrogenase (G6PDH) in 26 infants with a birthweight of 1000 - 1500 g. Results: The mean (SD) plasma glutathione concentration increased from day 0 to day 1 (14.9 (7.1) vs. 27.7 (11.9) mumol/L, p<0.001), and then decreased. The plasma cysteine concentration changed in the opposite direction ( 172 (59) vs. 129 (42) μmol/L, p<0.01). In infants with respiratory distress syndrome (RDS) the mean plasma glutathione concentration, but not cysteine, was lower on day 0 compared with infants without RDS (11.7 (5.2) vs. 21.4 (5.6) mumol/L, p<0.01). Erythrocyte glutathione concentration decreased during the first week of life, whereas erythrocyte cysteine concentration increased significantly from day 3 to day 7 (p<0.01). Erythrocyte cysteine and glutathione concentrations had a positive correlation. The GCL and GR activities did not change, but GST and G6PDH activities decreased during the first week (p<0.01). GPx activity decreased until day 3 (p<0.01) and was higher on day 0 and day 1 in infants with RDS. Conclusions: Very low birthweight infants have an initial increase in plasma glutathione and initial decrease in plasma cysteine level during the first week of life, and also a positive correlation between erythrocyte cysteine and glutathione levels.
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4.
  • Huotilainen, Minna, et al. (författare)
  • Auditory magnetic responses of healthy newborns
  • 2003
  • Ingår i: NeuroReport. - 1473-558X. ; 14:14, s. 1871-1875
  • Tidskriftsartikel (refereegranskat)abstract
    • We recorded magnetic brain activity from healthy human newborns when they heard frequency changes in an otherwise repetitive sound stream. We were able to record the magnetic counterpart of the mismatch negativity (MMN) previously described only with electric recordings in infants. The results show that these recordings are possible, although still challenging due to the small head size and head movements. The modelling of the neural sources underlying the recorded responses suggests cortical sources in the temporal lobes.
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5.
  • Kujala, A, et al. (författare)
  • Speech-sound discrimination in neonates as measured with MEG
  • 2004
  • Ingår i: NeuroReport. - 1473-558X. ; 15:13, s. 2089-2092
  • Tidskriftsartikel (refereegranskat)abstract
    • Magnetic brain responses to speech sounds were measured in 10 healthy neonates. The stimulation consisted of a frequent vowel sound [a] with a steady pitch contour, which was occasionally replaced by the vowel [i:] with a steady pitch, or the vowel [a] with a rising pitch, manifesting a change of intonation. The magnetic mismatch-negativity response (MMNm) was obtained and successfully modelled to the speech sound quality change in all infants and to the intonation change in 6 infants. The present results indicate that auditory-cortex speech-sound discrimination may well be studied with magnetic recordings as early as in newborn infants.
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6.
  • Leipala, JA, et al. (författare)
  • Haemodynamic effects of erythrocyte transfusion in preterm infants
  • 2004
  • Ingår i: European Journal of Pediatrics. - : Springer Science and Business Media LLC. - 1432-1076 .- 0340-6199. ; 163:7, s. 390-394
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of the study was to assess the short-term cardiorespiratory effects of a standard red cell transfusion in very low birth weight (<1500 g) infants undergoing intensive care. A total of 37 infants (birth weight 920+/-230 g, gestational age 27.8+/-2.1 weeks, age at study 6.1+/-3.9 days) with indwelling arterial lines were studied when 10 ml/kg of packed donor red cells were transfused based on clinical judgment. Infants with patent ductus arteriosus and/or inotropic treatment were excluded from the study. Oxygen saturation, left ventricular output, stroke volume, systolic, diastolic and mean arterial pressure, heart rate, and capillary refill time were assessed immediately prior to the transfusion and within an hour after the transfusion was completed. Capillary refill time after the transfusion was significantly shorter than prior to the transfusion (2.1+/-0.9 versus 2.4+/-1.0 s, P =0.033). Left ventricular output, stroke volume and arterial pressures remained unaltered. Oxygen saturation after the transfusion was lower than before the transfusion (94.0+/-3.8 versus 95.3+/-2.5%, P =0.014) despite unaltered oxygen supply. Conclusion: the data suggest that although a red cell transfusion of 10 ml/kg may marginally improve peripheral perfusion, it does not influence cardiac output and arterial blood pressure in normotensive preterm infants. It may, however, cause a transient decrease in oxygen saturation.
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7.
  • Nissila, I, et al. (författare)
  • Auditory hemodynamic studies of newborn infants using near-infrared spectroscopic imaging
  • 2004
  • Ingår i: IEEE Engineering in Medicine and Biology Society. Conference Proceedings. - 1557-170X. ; 2, s. 1244-1274
  • Tidskriftsartikel (refereegranskat)abstract
    • The noninvasive study of tissue blood volume and oxygenation using near-infrared light is a new and actively developing technology. We have used near-infrared spectroscopic imaging (NIRSI) to study hemodynamic responses on the auditory cortices evoked by auditory stimulation. Ten healthy newborn infants were studied. The otoacoustic emission hearing test was performed for each infant. Pulse oximetry was used to monitor the heart rate during the measurement, video recording was used to monitor motion artifacts, and the eye movements were noted in order to determine sleep stage. A 16-channel frequency-domain optical imaging system developed in our laboratory was used for NIRSI measurements. The stimuli were presented in trains of seven 1 kHz beeps with 700-ms inter-stimulus intervals. The stimulus trains were separated by 25-s silent periods in order to allow for the hemodynamic delay. In 3/8 cases, we obtained a clear bilateral increase in [HbO/sub 2/], and in two additional cases, a clear response on one hemisphere. The mean change in [HbO/sub 2/] was +0.9+/-0.9muM and the mean change in [Hb] was -0.3+/-0.4muM for those channels producing the largest response for each subject. No statistically significant response was found in 3/8 cases.
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9.
  • Ruusuvirta, T, et al. (författare)
  • Newborn human brain identifies repeated auditory feature conjunctions of low sequential probability
  • 2004
  • Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 20:10, s. 2819-2821
  • Tidskriftsartikel (refereegranskat)abstract
    • Natural environments are usually composed of multiple sources for sounds. The sounds might physically differ from one another only as feature conjunctions, and several of them might occur repeatedly in the short term. Nevertheless, the detection of rare sounds requires the identification of the repeated ones. Adults have some limited ability to effortlessly identify repeated sounds in such acoustically complex environments, but the developmental onset of this finite ability is unknown. Sleeping newborn infants were presented with a repeated tone carrying six frequent (P = 0.15 each) and six rare (P similar to0.017 each) conjunctions of its frequency, intensity and duration. Event-related potentials recorded from the infants' scalp were found to shift in amplitude towards positive polarity selectively in response to rare conjunctions. This finding suggests that humans are relatively hard-wired to preattentively identify repeated auditory feature conjunctions even when such conjunctions occur rarely among other similar ones.
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10.
  • Ruusuvirta, T, et al. (författare)
  • The newborn human brain binds sound features together
  • 2003
  • Ingår i: NeuroReport. - 1473-558X. ; 14:16, s. 2117-2119
  • Tidskriftsartikel (refereegranskat)abstract
    • To process a stimulus as a holistic entity, the human brain must be able to conjoin its different features. Previous evidence suggests that this ability emerges during the first months of life, implying its considerable dependence on postnatal development. We recorded human newborn (1-3 days of age) electrical brain responses to frequently occurring (standard) sounds and to rarely occurring (deviant) sounds in a series. Responses to deviants differed from those to standards despite the fact that only the combination of sound frequency and intensity could be used as a cue for discriminating between these sound types. Our finding suggests that the human brain is ready for auditory feature binding very soon after birth.
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