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- Ågren, Johan
(författare)
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Water transport through perinatal skin : Barrier function and aquaporin water channels
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- While constituting a well functioning interface with the aqueous environment in utero, the skin offers a poor barrier after very preterm birth. As a result, transepidermal water loss (TEWL) is high, a fact which has important clinical consequences in these infants. To investigate the transport of water through perinatal skin and the potential role of aquaporin (AQP), a water channel protein, in this process, we determined TEWL in a group of extremely preterm infants, and in an experimental rat model we analyzed the expression and distribution of AQP in perinatal skin in relation to TEWL, skin surface hydration and water content. The effects of antenatal corticosteroids (ANS) and of restricted intake of fluids and nutrients on barrier characteristics of the perinatal skin and its AQP expression were also studied.In infants born at 24 and 25 weeks of gestation TEWL was very high in the first days after birth and decreased with increasing postnatal age. At a postnatal age of 4 weeks, TEWL was still twice as high as previously reported in infants born at a gestational age of 25-27 weeks and four times higher than in infants born at term. In the rat model, immunohistochemical analysis revealed that AQP1 and AQP3 are abundantly expressed in the skin. AQP1 was expressed exclusively in dermal capillaries and AQP3 in basal layers of the epidermis. AQP1 and AQP3 mRNA as assessed by semiquantitative RT-PCR was higher in fetal than in adult skin. As in infants, TEWL and skin surface hydration were inversely related to gestational age in the rat. In preterm rat pups exposed to ANS, TEWL and skin surface hydration were lower than in unexposed controls, and AQP3 expression was selectively induced by ANS. In term newborn rat pups, restriction of fluid and nutrient intake resulted in a higher skin water content and higher TEWL early after birth, while at an age of 7 days TEWL was lower in fasting rat pups than in controls, although skin water content was still higher.To conclude, TEWL is very high in extremely preterm infants early after birth and then decreases at a slower rate than previously reported for a group of slightly more mature infants. This is the first time that the distribution and gene expression of AQP1 and AQP3 have been demonstrated in perinatal skin. The localization and expression of AQP in the skin might indicate that these water channels are involved in the regulation of skin hydration and transepidermal water transport in the fetus and newborn infant.
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- Agren, Johan, et al.
(författare)
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Antenatal Corticosteroids and Postnatal Fluid Restriction Produce Differential Effects on AQP3 Expression, Water Handling, and Barrier Function in Perinatal Rat Epidermis
- 2010
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Ingår i: Dermatology research and practice. - : Hindawi Limited. - 1687-6113 .- 1687-6105.
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Tidskriftsartikel (refereegranskat)abstract
- Loss of water through the immature skin can lead to hypothermia and dehydration in preterm infants. The water and glycerol channel aquaglyceroporin-3 (AQP3) is abundant in fetal epidermis and might influence epidermal water handling and transepidermal water flux around birth. To investigate the role of AQP3 in immature skin, we measured in vivo transepidermal water transport and AQP3 expression in rat pups exposed to clinically relevant fluid homeostasis perturbations. Preterm (E18) rat pups were studied after antenatal corticosteroid exposure (ANS), and neonatal (P1) rat pups after an 18 h fast. Transepidermal water loss (TEWL) and skin hydration were determined, AQP3 mRNA was quantified by RT-PCR, and in-situ hybridization and immunocytochemistry were applied to map AQP3 expression. ANS resulted in an improved skin barrier (lower TEWL and skin hydration), while AQP3 mRNA and protein increased. Fasting led to loss of barrier integrity along with an increase in skin hydration. These alterations were not paralleled by any changes in AQP3. To conclude, antenatal corticosteroids and early postnatal fluid restriction produce differential effects on skin barrier function and epidermal AQP3 expression in the rat. In perinatal rats, AQP3 does not directly determine net water transport through the skin.
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- Farooqi, Aijaz, et al.
(författare)
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Impact at Age 11 Years of Major Neonatal Morbidities in Children Born Extremely Preterm
- 2011
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Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 0031-4005 .- 1098-4275. ; 127:5, s. E1247-E1257
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Uncertainty continues regarding the extent to which neonatal morbidities predict poor long-term outcome and functional abilities in extremely preterm infants. OBJECTIVE: The goal of this study was to determine the impact of bronchopulmonary dysplasia (BPD), ultrasonographic signs of brain injury, and severe retinopathy of prematurity (ROP) on 11-year outcomes in infants born at < 26 weeks' gestation. METHODS: A total of 247 infants were born alive before 26 completed weeks of gestation from 1990 through 1992 in all of Sweden, and 98 (40%) survived to a postmenstrual age of 36 weeks. Main outcome measures were (1) poor outcome, defined as combined end point of death after 36 weeks' postmenstrual age or survival with at least 1 major disability at 11 years, and (2) consequences of chronic conditions in the survivors according to a validated instrument administered to parents. RESULTS: Brain injury and severe ROP but not BPD correlated independently with poor outcome at 11 years of age. Among children who were free from BPD, brain injury, and severe ROP, 10% had a poor outcome. Corresponding rates with any 1, any 2, and all 3 neonatal morbidities were 19%, 58%, and 80%, respectively. Multivariate analysis revealed that brain injury and severe ROP were associated with high rates of consequences of chronic conditions. CONCLUSIONS: In infants born extremely preterm who survive to a postmenstrual age of 36 weeks, severe ROP and brain injury separately predict the risk of death or major disability at 11 years of age. Thus, continued research to determine how to prevent these complications of prematurity is critical.
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- Farooqi, Aijaz, et al.
(författare)
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Mental health and social competencies of 10- to 12-year-old children born at 23 to 25 weeks of gestation in the 1990s : a Swedish national prospective follow-up study.
- 2007
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Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 0031-4005 .- 1098-4275. ; 120:1, s. 118-133
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Tidskriftsartikel (refereegranskat)abstract
- Abstract OBJECTIVE: We investigated a national cohort of extremely immature children with respect to behavioral and emotional problems and social competencies, from the perspectives of parents, teachers, and children themselves. METHODS: We examined 11-year-old children who were born before 26 completed weeks of gestation in Sweden between 1990 and 1992. All had been evaluated at a corrected age of 36 months. At 11 years of age, 86 of 89 survivors were studied and compared with an equal number of control subjects, matched with respect to age and gender. Behavioral and emotional problems, social competencies, and adaptive functioning at school were evaluated with standardized, well-validated instruments, including parent and teacher report questionnaires and a child self-report, administered by mail. RESULTS: Compared with control subjects, parents of extremely immature children reported significantly more problems with internalizing behaviors (anxiety/depression, withdrawn, and somatic problems) and attention, thought, and social problems. Teachers reported a similar pattern. Reports from children showed a trend toward increased depression symptoms compared with control subjects. Multivariate analysis of covariance of parent-reported behavioral problems revealed no interactions, but significant main effects emerged for group status (extremely immature versus control), family function, social risk, and presence of a chronic medical condition, with all effect sizes being medium and accounting for 8% to 12% of the variance. Multivariate analysis of covariance of teacher-reported behavioral problems showed significant effects for group status and gender but not for the covariates mentioned above. According to the teachers' ratings, extremely immature children were less well adjusted to the school environment than were control subjects. However, a majority of extremely immature children (85%) were functioning in mainstream schools without major adjustment problems. CONCLUSIONS: Despite favorable outcomes for many children born at the limit of viability, these children are at risk for mental health problems, with poorer school results.
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- Jennische, Margareta, et al.
(författare)
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School level at 10 years of age in children who required neonatal intensive care in 1980-1989
- 2006
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 95:12, s. 1586-1593
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Tidskriftsartikel (refereegranskat)abstract
- School level at age 10 was studied in two cohorts of children who had required neonatal intensive care (NIC): cohort 1, children born 1980-1985 (n=310); and cohort 2, children born 1986-1989 (n=245); and two control groups. More than 80% of all NIC children of both cohorts attended the appropriate mainstream grade 3 or 4; 12.9% of cohort 1 and 6.8% of cohort 2 were in mainstream grade 2. Six per cent of both cohorts received special education. Among very preterm children (23-31 gestational weeks), 73.5% of cohort 1 and 80.3% of cohort 2 attended grades 3 and 4, while 22.9% and 12.1%, respectively, were in grade 2. Assistance (remedial teaching, personal assistant or special teaching group) was given to 42.4% of cohort 1 in the mainstream (grades 2, 3 and 4) and to 38.2% of cohort 2 in the mainstream. In cohort 2, more very preterm girls than matched controls received assistance (p < 0.05); no corresponding difference was found in very preterm boys. Most children with congenital malformations received assistance in mainstream education or received special education. Conclusion: Most NIC children are in mainstream school classes at age 10. Twelve to 23% of very preterm children are 1 y behind. Many NIC children in the school mainstream need assistance at school, but the proportion of children in mainstream education increases markedly with time.
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- Johansson, Anders, 1972-, et al.
(författare)
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Monitoring of heart and respiratory rates in newborn infants using a new photoplethysmographic technique
- 1999
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Ingår i: Journal of clinical monitoring and computing. - 1387-1307 .- 1573-2614. ; 15:7-8, s. 461-467
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Tidskriftsartikel (refereegranskat)abstract
- Objective.A new photoplethysmographic (PPG) device for respiratoryand heart rate monitoring has been evaluated in the neonatal care units at theUniversity Children's Hospital of Uppsala, Sweden. The purpose of thisstudy was to compare this new device with more established techniques, i.e.,transthoracic impedance plethysmography (TTI) for monitoring of respiratoryrate and ECG for heart rate monitoring.Methods.Data were acquiredcontinuously for 8-hours in each of 6 neonates. The signals were analysed forperiods of 30 seconds, in which the heart and respiratory signals from the PPGdevice were compared with the ECG and the impedance plethysmogram.Results.The ECG recordings were of high quality in 77% of the analysed periods.In these periods, excluding periods (6%) disturbed by offset-adjustement ofthe PPG signal, the PPG heart signal included 1.1% (±0.7% SD) falsenegative beats and 0.9% (±0.6%) false positive beats. In periods withan impedance signal of high quality (29% of total time), the part of the PPGsignal synchronous with respiration included 2.7% (±1.1%) falsenegative breaths and 1.5% (±0.4%) false positive breaths. Here, 2% ofthe periods were discarded because of offset-adjustment. From the periods oflow signal quality, two other conclusions were drawn: 1) The impedance signalcontains more power in the respiratory range than the corresponding PPGrespiratory signal. 2) The breaths are easier to identify in the PPGrespiratory signal than in the impedance signal (subjective measure).Conclusions.Electrode and motion artefacts seem to disturb the ECGsignals and, particularly, the impedance signals. During periods of highquality ECG and impedance signals, the new optical device produces signals ofequal quality to these traditional methods, and is in some cases even better.The new device is non-invasive and has a small optical probe. These factors indicate further advantages of the photoplethysmographic method.
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