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Biomedical subjects

S Petersen

Publications and source records attributed to S Petersen.

At least 145 records · Page 8Linked to original sources
PubMed1982

The mechanism of gastrin release in cysteamine-induced duodenal ulcer.

Duodenal ulcer can be induced in rats by a single dose of cysteamine. The ulcer formation is accompanied by acid hypersecretion and elevated serum gastrin levels. This study was performed to elucidate the mechanisms of gastrin release after an ulcerogenic dose of cysteamine. Cysteamine induced a rise in serum gastrin from 29 +/- 5 pg/ml to a maximum of 203 +/- 62 pg/ml after 3 h in unoperated rats, whereas no rise was seen in vagotomized or antrectomized rats. The beta-adrenergic blocking agent propranolol strongly inhibited cysteamine-induced gastrin release, whereas atropine dependent on an intact vagus and may be mediated by beta-adrenergic receptors.

Animals↗
PubMed1981

Correlated changes in feeding behavior on selection for large and small body size in mice.

An automated method was used to record the temporal pattern of feeding of lines of mice selected over 15 generations for high and low body weight (L-mice and S-mice, respectively). Both L-mice and S-mice eat in meals concentrated during the night, and meal frequency is similar in the two lines, but L-mice consume much larger meals, each made up of many more separate feeding bouts. The outbred strain from which the selected lines were derived has a similar basic pattern of feeding in meals, which becomes like that of L-mice when the animal's thermogenic metabolic rate is high, and like that of S-mice when it is low, suggesting that the differences between the feeding patterns of the two selected lines are a secondary consequence of alterations in whole body metabolic rate.

Animals↗
PubMed1981

Serum indomethacin concentrations after intravenous administration to preterm infants with patent ductus arteriosus.

Six preterm infants with PDA received 14 treatments with indomethacin 0.2 mg/kg intravenously. Auscultatory and echocardiographic assessment indicated closure of the duct in 2, partial closure in 2, and no effect in 2 infants. The mean serum concentration of indomethacin was: 15 min after the first injection 1 314 ng/ml, after 1 hour 970 ng/ml, after 6 hours 718 ng/ml, and after 24 hours 388 ng/ml. The mean half-life of indomethacin in the serum was 20 hours (range 9-50 hours). Side effects in all infants were hyponatraemia, decreased urinary output, decreased urinary sodium excretion, and weight gain. One infant had transient thrombocytopenia and gastrointestinal haemorrhage. By intravenous administration of indomethacin in a dose of 0.2 mg/kg to preterm infants a sufficiently high serum concentration is obtained shortly after the injection. To maintain a high serum concentration for a longer period it is recommended to give a second dose of 0.2 mg/kg after 6 hours and if necessary a third dose of 0.1 mg/kg 24 hours after the first dose.

Ductus Arteriosus, Patent↗
PubMed1981

Effect on serum calcium of a alpha-hydroxy-vitamin D3 supplementation in infants of low birth weight, infants with perinatal asphyxia, and infants of diabetic mothers.

Thirty infants of low birth weight, 35 infants with perinatal asphyxia, and 16 infants of diabetic mothers were investigated for early neonatal hypocalcaemia. The infants were randomized into a group prophylactically given 1 alpha-hydroxy-vitamin D3, 0.05 or 0.10 micrograms/kg i.v. on the first 3 days of life, and an untreated control group. In infants of low birth weight and infants of diabetic mothers there were no differences in serum ion-Ca concentrations on days 2, 3, 5, and 7 between the treated and untreated groups. In infants with perinatal asphyxia, however, serum ion-Ca concentrations on days 5 and 7 were significantly higher in the treated than in the untreated group, while on days 2 and 3 the differences were not statistically significant. The hypocalcaemia in asphyctic infants was not correlated to bicarbonate treatment, but infants with severe signs of asphyxia had lower serum ion-Ca concentrations than infants with only mild or no signs. Hypocalcaemia in asphyctic infants might be explained by a decreased concentration of 1 alpha, 25-dihydroxy-vitamin D3 following reduced 1 alpha-hydroxylation in the kidney as a consequence of anoxia during perinatal asphyxia.

Asphyxia Neonatorum↗
PubMed1981

Hypernatraemia, diabetes mellitus, hyperprolactinaemia, retarded growth and delayed puberty in a 14 year old girl. Effect of bromocriptine treatment.

Investigations in a 14 year old girl with arrested growth for 2 years, delayed pubertal development, hypernatraemia without thirst, diabetes mellitus and hyperlipaemia are reported. The hypernatraemia was accompanied by a low vasopressin concentration with an abnormal response to thirst, high plasma renin but normal plasma aldosterone concentrations. Treatment with vasopressin and increased fluid intake decreased serum sodium levels. Serum gonadotrophins were low; GH response during an insulin tolerance test was subnormal and basal serum Prl concentration was elevated. Bone age, thyroid function and adrenal function were normal. After initiation of bromocriptine treatment her growth accelerated and regular menstruations commenced. The serum gonadotrophin levels increased and showed pulsatile release. A hypothalamic disorder is suggested, but no cerebral lesion could be demonstrated.

Adolescent↗
PubMed1980

Megakaryocytes in the foetal circulation and in cubital venous blood in the mother before and after delivery.

22 newborn infants delivered by Caesarean section were investigated in order to ascertain the number and morphology of megakaryocytes in the umbilical artery and vein. Averages of 65.5 and 47 MK per ml blood were found, respectively. 25% of MK in the artery and 8% in the vein had copious cytoplasm. Thus there was a significantly higher total number of MK and number of MK with copious cytoplasm in blood from the artery than from the vein (P less than 0.05). In blood from the aorta in 16 newborn infants we found an average of 28 MK per ml blood, 8% had copious cytoplasm. There was a significantly smaller number of MK in the aorta than in both the artery and the vein of the umbilical cord (P less than 0.05). There was the same percentage of MK with copious cytoplasm in the aorta as in the umbilical vein. The number of MK in cubital venous blood from the mother prior to delivery was 17.5 MK per ml and was significantly higher than about 3 months after delivery when it was 5 MK per ml blood, which is a normal value (P less than 0.05). In both series, 1.5% of MK had copious cytoplasm, as in a normal material.

Aorta↗
PubMed1980

Acute haematogenous osteomyelitis and septic arthritis in childhood. A 10-year review and follow-up.

Seventy-three children, who were admitted to hospital during the period 1965-1976 with osteomyelitis or septic arthritis, were included in a retrospective study as well as a clinical and radiological follow-up. Ten cases of osteomyelitis occurred during the neonatal period and about half of the cases of osteomyelitis and septic arthritis occurred before the age of 2 years. Staph. aureus was the dominating pathogen isolated and half of the strains were penicillin-resistant. The group of children with osteomyelitis who were given early treatment, i.e. within 1 week, against penicillin-resistant Staph, aureus had a higher clinical cure rate after 1 month (0.01 < P < 0.025) compared with the rest of the children. Five children developed recurrent or chronic osteomyelitis. An early follow-up in 69 children 1-11 years after the disease showed that none had any complaints or invalidity. However, one patient with neonatal septic arthritis presented severe dysplasia and subluxation of the hip and four children with osteomyelitis had severe, but asymptomatic, radiological changes.

Adolescent↗
PubMed1979

Fetal thyrotoxicosis in utero.

A case of fetal thyrotoxicosis in utero in a boy with familial predisposition to thyrotoxicosis is reported. At 26 weeks of gestation fetal hyperkinesia and fetal tachycardia developed. This was preceded by a significant pathologic increase in long-acting thyroid stimulator (LATS) in the mother. The fetal hyperkinesia and tachycardia were considered to be signs of fetal thyrotoxicosis, possibly induced by placentally transferred LATS. The fetal thyrotoxicosis responded well to propylthiouracil given to the mother. After birth the boy developed slight signs of neonatal thyrotoxicosis although his serum thyroxine values increased analogous to those of his elder sister, who had presented classical neonatal thyrotoxicosis.

Female↗
PubMed1978

Effects of testosterone upon feeding in male mice.

Food intake and pattern of feeding were recorded in intact and castrate male mice. Intact adults are larger and eat more than pre-pubertal castrates, due to rapid growth at puberty. Castration in adulthood has little effect upon food intake, but feeding becomes concentrated into large, infrequent meals. The change in meal size appears primary and is reversed by testosterone. During rapid growth at puberty, both meal size and frequency are high. It is suggested that testosterone affects feeding in two ways. Rapid weight gain at puberty leads to high meal size and frequency, but in adulthood meal size is depressed. Meal size in adults is further depressed by stimuli from females, and it is argued in this case that testosterone affects a general mechanism for altering feeding when other activities have a high priority.

Animals↗
PubMed1978

Pseudohypoaldosteronism. Clinical, biochemical and morphological studies in a long-term follow-up.

A boy with pseudohypoaldosteronism was followed from birth to the age of 7 years. Failure to thrive, vomiting, dehydration, hyponatraemia and urinary sodium loss were prominent findings. Urinary excretion of corticosteroid metabolites was normal. Before treatment, excessively high plasma renin concentration was found, associated with a marked activation of aldosterone secretion. A renal biopsy showed pronounced hypertrophy of the juxtaglomerular apparatus. Persisting metabolic acidosis and an insufficient urinary acidifying capacity suggested the presence of distal renal tubular acidosis. Treatment with sodium bicarbonate and sodium chloride from 19 to 31 months of age resulted in normal growth and normal physical and mental development. The plasma electrolytes were normalized but a pronounced activation of the renin-aldosterone system persisted after therapy, and on sodium restriction this system responded with a considerable further activation.

Aldosterone↗
PubMed1978

Long-term prophylaxis with methenamine hippurate in girls with recurrent urinary tract infections.

Twenty girls, aged 5-12 years, with recurrent urinary tract infections, were treated with methenamine hippurate, Hiprex, for a period of 12 months. The number of infections per patient per year was reduced from 3.1 to 0.7 (p less than 0.001). After prophylaxis was stopped this number increased to 1.4 which is a significantly higher incidence than occurred during treatment (p less than 0.05). A few girls complained of the taste but no side-effects were observed. Methenamine hippurate is a useful alternative in long-term prophylaxis against recurrent urinary tract infections in girls.

Child↗