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Biomedical subjects

G Sedin

Publications and source records attributed to G Sedin.

At least 91 records · Page 5Linked to original sources
PubMed1984

Cystic ovaries in a pre-term newborn infant.

Oestrogen-producing ovarian cysts in a very pre-term infant led to swelling of the labia majora and of the lower abdominal wall. Following surgical removal of the left ovary the serum concentration of oestradiol decreased temporarily. Less than 2 weeks after surgery several new cysts appeared in the right ovary. Treatment with medroxyprogesterone acetate resulted in disappearance of these cysts. Simultaneously the serum concentration of oestradiol fell to a normal level.

Estradiol↗
PubMed1984

Effects of human albumin infusion on transepidermal water loss in newborn infants.

A study was made to determine whether the high transepidermal water loss in preterm newborn infants is affected by infusion of human albumin. In 7 preterm infants, born after 25-30 weeks of gestation, 0.5 g of human albumin per kilogram body weight (b.w.) was infused through an umbilical artery catheter in 6 h on the 1st day after birth. In 2 other infants, born after 28 completed weeks of gestation, human albumin in an amount of 1.0 g/kg body weight was infused. The plasma albumin concentration increased significantly from a pre-infusion value of 27.1 to 29.5 g/l after 4 h of infusion. Simultaneously the transepidermal water loss decreased from 26.6 to 23.5 g/(m2 X h); this difference was also significant. Within 2 h after the end of the albumin infusion, both the plasma albumin concentration and the transepidermal water loss had returned to levels that were not significantly different from the pre-infusion values. Plasma osmolality and sodium concentration did not alter during the infusion, nor did arterial blood pressure.

Body Water↗
PubMed1983

Plasma theophylline and caffeine and plasma clearance of theophylline during theophylline treatment in the first year of life.

Plasma concentrations of caffeine and theophylline were simultaneously determined in 17 preterm infants after oral administration of aminophylline for treatment of apnoea. The ratio of caffeine/theophylline concentration in plasma increased during the first 2 weeks of treatment, owing to the longer time required for caffeine than for theophylline to reach steady state. The caffeine/theophylline ratio at steady state was 0.57 +/- 0.03 (mean +/- SE). Thus, caffeine contributed significantly to the total methylxanthine load in the infants. The plasma clearance of theophylline was calculated from the plasma steady state concentrations. In 3 preterm infants treated with oral aminophylline, repeated sampling showed an approximately linear increase in clearance with time from 16.8 +/- 0.4 (mean +/- SE) at a postnatal age of 6-11 days to 30.9 +/- 2.5 ml/kg/h at 64-69 days. In 1 full-term infant treated with oral theophylline from 3.5 to 11.5 months of age, the plasma clearance of theophylline increased in a roughly linear manner, reaching a plateau of about 100 ml/kg/h at 6-7 months of age. This corresponds to the clearance found in 1-4 year old infants.

Apnea↗
PubMed1983

Alveolar deadspace during high frequency positive pressure ventilation. Influence of ventilatory pattern.

Pulmonary gas exchange was studied in association with high frequency ventilation and its relation to the duration of insufflation and end-expiratory pressure investigated. Alveolar deadspace, alveolar ventilation and the alveolar-arterial oxygen difference were obtained in cats receiving a constant minute ventilation. Alveolar deadspace increased with ventilatory frequency when a long insufflation time was used. A positive end-expiratory pressure (PEEP) decreased the alveolar deadspace in high frequency ventilation. Thus, with the low compressible volume ventilator, more efficient high frequency ventilation can be achieved with a short period of insufflation plus low PEEP.

Animals↗
PubMed1983

Transepidermal water loss in newborn infants. VIII. Relation to gestational age and post-natal age in appropriate and small for gestational age infants.

In 68 appropriate for gestational age (AGA) and 33 small for gestational age (SGA) infants, transepidermal water loss was studied during the first four weeks after birth. The method used to measure evaporation rate is based on measurement of the water vapour pressure gradient close to the skin surface. All measurements were made at an ambient humidity of 50% and with the infants calm and quiet. At all the investigated post-natal ages in both AGA and SGA infants, an exponential relationship was found between transepidermal water loss (g/m2 h) and gestational age, this loss being much higher in the pre-term infants than in those born at term. The transepidermal water loss was generally lower in SGA than in AGA infants during the first week of post-natal life, irrespective of gestational age at birth. There was a gradual decrease in transepidermal water loss with increasing post-natal age in both pre-term AGA and pre-term SGA infants. Three weeks after birth this water loss tended to be higher in pre-term SGA infants than in pre-term AGA infants of corresponding gestational age.

Age Factors↗
PubMed1983

Transepidermal water loss in newborn infants. IX. The relationship between skin blood flow and evaporation rate in fullterm infants nursed in a warm environment.

In order to investigate whether a change in skin blood flow is associated with changes in the evaporative loss of water from the skin of fullterm appropriate for gestational age infants, we measured the evaporation rate and skin blood flow in the body temperature range 36.6 to 37.2 degrees C. Fifteen healthy, fullterm newborn infants delivered by Caesarean section were studied in a warm environment. Evaporation rate and skin blood flow were measured non-invasively without disturbing the infant. When the body temperature slowly rose because of the warm environment, the skin blood flow steadily increased. The rate of evaporation of water from the skin slowly decreased until a body temperature of 37.1 degrees C was reached. The evaporation rate then suddenly increased as the infant began to sweat. Thus, in fullterm newborn infants born by Caesarean section the skin blood flow increases in the body temperature range 36.6-37.1 degrees C but does not influence the evaporation rate from the skin.

Body Temperature Regulation↗
PubMed1983

Transepidermal water loss in newborn infants. X. Effects of central cold-stimulation on evaporation rate and skin blood flow.

In order to investigate whether sweating and cutaneous vasodilatation. induced by a warm environment, is inhibited by central cold-stimulation, the evaporation rate and skin blood flow were studied by non-invasive techniques before and after the feeding of cold glucose to 17 fullterm appropriate for gestational age infants, born by elective Caesarean section, on their first day after birth. In newborn infants who were visibly sweating and had an increased skin blood flow at a body temperature above 37.1 degrees C, such central cold-stimulation quickly inhibited sweating and decreased skin blood flow. In infants with almost the same body temperature but with no sweating, this stimulation caused no change in evaporation rate or skin blood flow. The regulation of body temperature in fullterm newborn infants can thus be disturbed by central cold-stimulation, resulting in a decreased heat loss to the environment even though the body temperature is elevated.

Body Temperature Regulation↗
PubMed1983

Transepidermal water loss in full-term and pre-term infants.

The amount of water lost from the skin and the relation of the water loss to environmental factors, activity, body temperature, gestational age, nutritional status at birth and post-natal age were studied in full-term and pre-term newborn infants. The method we used was non-invasive and based on determination of the water vapour pressure gradient immediately above the skin surface. We found that the transepidermal water loss per unit time and area (TEWL; g/m2 h) could be calculated by using values from only three measurement sites. TEWL increased with activity and when body temperature was elevated above 37.1 degrees C. On the first day after birth TEWL in appropriate for gestational age (AGA) infants was exponentially related to gestational age, with much higher values in the most pre-term infants than in full-term infants. In full-term small for gestational age (SGA) infants TEWL was significantly lower than in full-term AGA infants. In pre-term and full-term AGA infants and in full-term SGA infants we found an inverse linear relationship between ambient humidity and evaporation rate (ER; g/m2 h) from the skin. The level of ER and the slope of the relationship depended on the gestational age of the infant, with higher ER in the more pre-term infants. Analysis of the relationship between ambient humidity and ER indicated that there is a gradual change in the permeability of the skin with gestational age. In pre-term infants TEWL gradually decreased during the first weeks of life. In full-term AGA infants TEWL was almost unchanged during these first weeks.

Body Temperature↗
PubMed1983

Water evaporation and heat exchange with the environment in newborn infants.

The amount of water evaporated from the skin of newborn infants and the temperatures of the skin, the ambient air and the surfaces facing the infants were measured and used to calculate the evaporative, radiative and convective heat exchange between the infant and the environment in infants of varying gestational ages. Immediately after birth the evaporative heat exchange was very high but it then decreased gradually. The radiative heat exchange was very high in the delivery room but lower in the incubators. In incubators the evaporative heat exchange was high in the most pre-term infants, especially when nursed at a low ambient humidity. Different modes of heat exchange were interrelated, so that when the pre-term infants had a high evaporation rate, a high ambient temperature was needed and the heat exchange through radiation and convection decreased. Net heat exchange was lowest in very pre-term infants at an ambient humidity of 60%.

Body Temperature↗
PubMed1982

Cerebrospinal fluid ferritin in newborn infants. Elevated levels in cerebral infection or bleeding.

One hundred and four infants with neurological symptoms or suspected infection during the neonatal period were consecutively investigated with respect to ferritin and albumin concentrations in the cerebrospinal fluid (CSF). In some cases serial determinations of CSF ferritin were performed during the period in the neonatal unit. CSF ferritin was significantly higher in infants that recovered very soon from a transient neonatal disorder (TND) than in apparently healthy adults. No difference in CSF ferritin was found between full-term infants with TND and pre-term infants with TND or asphyxiated infants. Three out of five infants with septicaemia or meninigitis showed a marked increase in CSF ferritin during the observation period, and the same finding was made in three infants with intracranial bleeding, in whom CSF ferritin values 100 times the upper reference limit for infants with TND were recorded. In two infants with neonatal convulsions secondary to asphyxia moderate CSF elevations were observed. No correlation was found between ferritin and albumin in CSF, suggesting that other mechanisms than passive penetration from blood into CSF must have been responsible for the raised levels of CSF ferritin. More likely the observed ferritin increments reflect ferritin release from macrophages undergoing phagocytosis either induced by cerebral bleeding or due to infectious agents.

Adult↗
PubMed1982

Transepidermal water loss in newborn infants. VI. Heat exchange with the environment in relation to gestational age.

The amount of water evaporated from the skin of newborn infants and the temperatures of the skin, of the ambient air, and of the surfaces facing the infants were measured and used as a basis for calculation of the evaporative, radiative and convective heat exchange between the infant and the environment. The infants were of varying gestational ages, from 25 to 39 completed weeks of gestation. Evaporative heat exchange was high in the most preterm infants when nursed at a low ambient humidity, while the high ambient humidity needed to maintain these infants at a stable body temperature led to a low loss of heat through radiation and convection or even a heat gain. In the more mature infants evaporative heat exchange was lower, while radiative and convective heat exchange was higher.

Body Temperature↗
PubMed1982

Transepidermal water loss in newborn infants. VII. Relation to post-natal age in very pre-term and full-term appropriate for gestational age infants.

During the first weeks after birth the transepidermal water loss was determined repeatedly in 7 infants born after 25-27 weeks of gestation, in 13 infants born after 28-30 weeks and in 14 full-term infants. All infants were appropriate for gestational age. The very pre-term infants had high evaporative water losses from their skin on their first days after birth. A gradual decrease was then observed, but after four weeks the values were still higher than those in full-term infants. The transepidermal water loss in full-term infants was unchanged during the first two weeks of life, but increased during the subsequent two weeks. The relation between evaporation rate from an interscapular skin area and ambient humidity was studied repeatedly during the first week of life in two very pre-term infants. The magnitude of evaporation decreased with increasing post-natal age, but was still dependent on the ambient relative humidity.

Female↗
PubMed1982

A low continuous positive airway pressure induces regular breathing and increased inspiratory activity in newborn lambs.

To determine the lowest continuous positive airway pressure (CPAP) at which breathing becomes regular and to determine whether the phrenic nerve activity changes simultaneously, breathing pattern and phrenic nerve activity were studied in spontaneously breathing newborn lambs at various levels of CPAP. A CPAP of 0.25 kPa decreased the variability of phrenic burst interval, i.e. made the breathing regular. This CPAP also increased the mean impulse frequency within the phrenic nerve bursts, indicating greater inspiratory activity. A high CPAP did not offer any further advantages to the breathing pattern or to the inspiratory activity.

Animals↗
PubMed1982

Neonatal convulsions treated with continuous, intravenous infusion of diazepam.

Eight patients born at term in the years 1974-76, with neonatal convulsions due to severe perinatal asphyxia, were treated for 6-11 days with continuous intravenous infusion of diazepam. Doses of 1.0-1.5 mg per hour (mg/h) were usually required to stop the convulsions. In one infant 2.75 mg/h was needed. During the treatment, all infants had measurable serum concentrations of diazepam, half of them above 35 mumol/1. The convulsions stopped in all eight infants, and did not return after discontinuation of the infusion. Side-effects were noted in all infants, but they were all able to breathe adequately. At follow-up the psychomotor development was normal in all cases and there were no signs of neurological disorders, except in one patient, in whom mild epilepsy was observed. Continuous infusion of diazepam should be given in doses of at least 1 mg/h (corresponding to around 0.3 mg/kg h) to stop convulsions in full-term infants efficiently and should be increased under close supervision and with monitoring of respiration and heart rate until treatment is effective.

Diazepam↗
PubMed1981

Case report. Trisomy 9 syndrome.

Two cases of trisomy 9 are described. Patient 1 is the fourth case of complete trisomy 9 to be reported, and the third reported to have been born alive. This patient showed an anomaly of the perineum, with a short distance between the anus and vulva, and the circular muscle around the anus was missing. Like earlier cases of complete trisomy 9, this girl died in the neonatal period. Patient 2, with a trisomy 9 mosaicism, had a mesenterium commune. The two above-mentioned malformations have not been described previously as part of the syndrome. The features of the trisomy 9 syndrome and the differences between infants with trisomy 9 and trisomy 9 mosaicism are discussed.

Abnormalities, Multiple↗
PubMed1981

Measurement of water transport through the skin.

A method for measuring water exchange through human skin has been developed. It is based on estimation of the vapour pressure gradient immediately above the surface of the skin and permits the skin area investigated to be exposed to the ambient air during the entire period of measurement. Influence on the microclimate above the skin, with respect to humidity and temperature, is thereby minimized. An instrument for measuring small amounts of water evaporated from or absorbed by a surface per unit time and area is described and its accuracy discussed. The instrument has a high degree of accuracy and better sensitivity than previously described devices used for this purpose. It has been used primarily to investigate the rate of evaporation from the skin surface in newborn infants and from the skin in patients with burns.

Biological Transport↗