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Biomedical subjects

B Winbladh

Publications and source records attributed to B Winbladh.

At least 37 records · Page 2Linked to original sources
PubMed1985

Early postnatal development of transport functions in the rabbit choroid plexus.

The development of transport functions in the rabbit choroid plexus was followed postnatally up to 2 months after birth. The activity of ouabain-sensitive Na+, K+-ATPase in newborn rabbit choroid plexus composes about one-fourth (lateral and third ventricle) to one-half (fourth ventricle) of the activity in the adult animal, and it increases markedly within the first 3 weeks of early life. A similar profile of postnatal changes is observed for the capacity to take up and accumulate the organic base choline, which is about three to five times higher for the adult rabbit than for the newborn animal. This coincides with the maturation of the epithelial cells as well as with the development of the sympathetic nerve supply in the choroid plexus. The results suggest that energy-dependent translocation systems influenced by local sympathetic nerves in the choroid plexus, at the interface between blood and CSF, have a functional role shortly after birth.

Adenosine Triphosphatases↗
PubMed1985

Influence of thyroid hormones on transport function and Na+-K+-ATPase activity in the rat choroid plexus.

The sympathomimetic stimulation of choroid plexus transport and secretion in rat seems to be mediated by beta-adrenergic receptors. In the present report the effect of induced changes in thyroid function on transport mechanisms in the rat choroid plexus was studied. Following induction of hyperthyroidism (treatment with T3 for 10 days) the tissue/medium ratio (T/M) for choline uptake in choroid plexus in vitro decreased significantly by 68%. The Na+-K+-ATPase activity showed a statistically significant increase of about 16%. Also following cervical sympathectomy, T3 caused a reduction of the T/M for choline, to the same level as in the non-sympathectomized animals, while the effect of T3 on the Na+-K+-ATPase activity was changed into a 22% decrease. Hypothyroidism (administration of PTU in the drinking water) had little or no effect on the uptake and accumulation of choline in the choroid plexus. The Na+-K+-ATPase activity was reduced by 40%, in contrast to the stimulating effect of T3. There is, hence, reason to believe that the transport of choline in the choroid plexus is only partly regulated by adrenergic mechanisms acting via Na+-K+-ATPase. The major effect of T3 on the choline uptake may be exerted by a mechanism different from the ATPase activity and not involving adrenergic receptors.

Animals↗
PubMed1984

Cord blood T lymphocyte subpopulations in premature and full-term infants.

Cord blood lymphocyte preparations from premature and full-term infants were examined for T cell subsets using monoclonal antibodies. The number of T cells in relation to the total number of lymphocytes, the proportions of T helper (Th), and T suppressor (Ts) phenotypes, respectively, were the same in preterm infants of gestational age (GA) 26-36 weeks and term infants (GA 38-41) weeks). There was no correlation between GA and Th/Ts ratio. The relative number Ts was significantly lower in infants than in adult women.

Adult↗
PubMed1982

Bacterial colonization of newborn infants in a neonatal intensive care unit.

The bacterial colonization of the nose, umbilicus, perineum and faeces in 85 newborns was studied during one period of high and one of low occupancy in a neonatal intensive care unit. Cultures were taken on admission, at three days, at one week of age, and then weekly during the stay in the unit. Colonization took place early and potential pathogens were responsible for a significant part of the spectrum. At one week of age, more than 50% of the infants had Staphylococcus aureus in the nose and umbilicus, 25% had E. coli and/or Klebsiella enterobacter in the umbilicus, and 60% had Klebsiella enterobacter in the perineum. Neither the occupancy rate in the unit nor the clinical state of the infant seemed to influence the colonization pattern significantly. Changes in flora were frequent in the individual infant. However, the bacterial spectrum remained essentially the same with increasing age during the stay in the unit and during the two periods. Only on two occasions was the same phage type of Staphylococcus aureus found in two infants at the same time. Two cases of septicemia occurred in the 85 infants during the three months of the study. Both infants were colonized beforehand with the causative organism. The results may indicate that the clinical state of the infant is of greater importance for risk of septicemia than the pattern of the bacterial colonization.

Bacteria↗
PubMed1981

Sympathetic influence on transport functions in the choroid plexus of rabbit and rat.

In vitro uptake of an organic base (choline) and an organic acid (p-aminohippuric acid; PAH), both radiolabelled, was measured in isolated choroid plexus of rat and rabbit, and expressed as tissue/medium ratios. A significant increase in the tissue accumulation of choline was seen in denervated rabbit choroid plexus 1 week following unilateral cervical sympathectomy. The accumulation of PAH was not affected. The uptake of both test substances was significantly reduced after sympathetic denervation of the rat choroid plexus. The results agree with the local sympathetic inhibition of cerebrospinal fluid production in rabbit (corresponding studies on rat have not been performed), and favour the assumption that the adrenergic nerves in the choroid plexus mediate direct effects on the plexus epithelium.

Aminohippuric Acids↗
PubMed1980

The effects of pharmacological treatment on pulmonary function in children with exercise-induced asthma.

The effects of two therapeutic regimens were investigated in eleven boys and eight girls (8--13 years) with a history of exercise-induced asthma (EIA), who reacted with subjective signs of EIA and a decrease in FEV1.0 exceeding 10% after an exercise test. A test program (TP) including complete spirometry, bicycle ergometer and treadmill exercise tests preceded and followed by dynamic spirometry at one and five min after exercise, was performed before and after each treatment period. In 12 patients with sporadic medication before the trials, continuous peroral treatment with a combination of a beta 2-stimulating drug and a xanthine derivative for three weeks did not significantly improve TP data. In 13 children (six from the above group) who were already on continuous treatment as above, addition of disodium cromoglycate (DSCG) inhalations for 3--4 weeks improved the response to acute administration of a beta-receptor stimulatory aerosol but did not influence EIA. Seven of the children continued their DSCG treatment for one year. Minor improvement of EIA provoked by cycling but not by treadmill was seen after this. The ventilatory effort in relation to working intensity was lowered. No significant differences were found between treadmill running and cycling in provoking asthma.

Adolescent↗
PubMed1979

Pharmacokinetics of theophylline in young children with asthma: comparison of rectal enema and suppositories.

Six children, aged 2 months - 4 years, received theophylline 5-6 mg/kg intravenously. Its disposition could be described by a two-compartment open model, the mean serum half life (t 1/2 beta) was 3.75 h, i.e., shorter than in adults, but there was a considerable interindividual variation (1.8-7.0 h, in one patient 13.3 h). Thirteen children (2 months - 4 years) received theophylline suppositories in a dose of 3.8-5.0 mg/kg, and ten (6 months - 4 years) in a dose of 8.4-14.5 mg/kg. Absorption was slow (mean half-time 43 min), incomplete and variable (biological availability 8-100%, mean 80%). Only four of the patients given the higher dose and none given the lower dose reached a therapeutic serum concentration (10-20 microgram/ml). Nine children (6 months - 4 years) received rectal enemas of theophylline 4.1-9.2 mg/kg. Absorbtion was rapid (mean half-time 5.5 min) and biological availability averaged 100%. Six patients reached a serum concentration within the therapeutic range. Using the mean values of the calculated pharmacokinetic parameters, rectal enemas providing a dose of theophylline of 6-8 mg/kg t.i.d. were computed to give serum concentrations between 8-20 microgram/ml, without producing too high a level during the absorption phase.

Age Factors↗
PubMed1979

Accidental poisoning in pre-school children in the Stockholm area. Medical, psychosocial and preventive aspects.

Accidental poisoning in pre-school children requiring hospital admission has increased sixfold from 1955 to 1975 in the Stockholm area. The mortality from this accident has decreased from 0.5 to less than 0.1 per 100 000 pre-school children in the whole of Sweden during the same period. Medical and psychosocial background factors were investigated in 104 consecutive in-patients (0--6 years old) with accidental poisoning and compared to an out-patient group, a group of patients who only had called the poison control centre, and a matched control group from Child Health Centres. There were no difference between the groups regarding health and history of earlier accidents except that 20--25% of the families of the poisoned children and 7% of the control families had called the Poison Control Centre before. Change of residence during the last 6 months was much commoner among families of poisoned children than of nonpoisoned. Other social stress factors were more common among in-patients than out-patients. The measures taken by the parents to combat the poisoning were adequate in most cases. The decrease in mortality inspite of the increase in potentially dangerous accidental poisonings may be attributed to a good knowledge among parents about adequate measures and where to seek advice resulting in early treatment, and to intensive care and antidote therapy.

Accident Prevention↗
PubMed1978

The influence of amphetamine addiction on pregnancy and the newborn infant.

The influence of amphetamine addiction on pregnancy and the newborn infant has been studied retrospectively in 23 cases. Six of the mothers claimed to have discontinued their abuse in early pregnancy, while the remaining 17 mothers continued throughout. In comparison with the average number of visits by pregnant Swedish women to maternal health centres, the 17 women who continued their abuse made significantly fewer visits, although there was a wide variation. Complications related to pregnancy and delivery were few, however. One child with a myelomeningocele was stillborn. Six children were preterm and three small for gestational age. Two full-term children were extremely drowsy and in need of tube feeding, symptoms that might be due to the maternal abuse. Eight of the ten mothers, who had previous children placed in foster homes by the Social Welfare Department, left the hospital with their newborn infant in their care as well as all the eleven primiparae.

Adolescent↗
PubMed1975

Clearance of some quaternary amines from the spinal subarachnoid space.

The spinal subarachnoid space was perfused with artificial cerebrospinal fluid (CSF) from the low lumbar level to the middle thoracic level or to the cisterna magna in anesthetized rabbits. 3-H-choline, 3-H-methyl-atropine or 3-H-decamethonium with carrier in different concentrations was added to the perfusate together with 14-C-inulin, the latter serving as a marker of the dilution of the perfusate by original CSF. Choline was eliminated from the perfusate partly by a saturable mechanism probably by an uptake into the spinal cord. About 15 per cent of the radioactivity of the choline infused was recovered from the spinal cord mainly as phosphorylcholine, betaine, and phospholipids. Amphetamine decreased the elimination of choline from ventriculocisternal perfusates and partly inhibited the uptake of choline in rabbit choroid plexus in vitro. In contrast, amphetamine did not influence the saturable elimination of choline in the lumbothoracic perfusion. Neither methylatropine nor decamethonium was eliminated from the perfusate by a saturable mechanism in the lumbothoracic perfusions. However, in perfusions including the cisterna magna methylatropine was partly eliminated by such a mechanism. The concentration of radioactivity in fourth ventricular choroid plexa suggested this structure to be responsible for the saturable part of the elimination. In conclusion, there is no active removal of quaternary amines in general from spinal CSF like the choroid plexus mediated clearance from ventricular CSF.

Animals↗