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Biomedical subjects

S Larsen

Publications and source records attributed to S Larsen.

At least 217 records · Page 12Linked to original sources
PubMed1991

Urine profiles and kidney histology following intravenous diatrizoate and iohexol in the degeneration phase of gentamicin nephropathy in rats. Effects on urine and serum profiles.

Urine chemical profiles were followed for three or nine days after intravenous injection of diatrizoate, iohexol, or saline in 30 rats, where a tubulointerstitial nephropathy was induced by gentamicin given over an eight-day period. Another ten rats injected with saline served as controls. Compared to injection of saline, both iohexol and diatrizoate induced dysfunction. The excretion of the cytoplasmic enzyme lactate dehydrogenase was significantly greater following iohexol than following diatrizoate. No significant differences between the two media were shown by the various serum components examined. Among the gentamicin-treated rats, light microscopy showed prolonged occurrence of tubular necrosis and a more intensive round cell infiltration following iohexol than following diatrizoate and saline. Both contrast media induced further temporary renal dysfunction in rats with gentamicin nephropathy; iohexol induced more morphologic changes than diatrizoate.

Animals↗
PubMed1991

Pretreatment with steroids before intravenous injection of diatrizoate or iohexol. Effects on urine and serum profiles.

The effects on urine and serum profiles of intravenous injection of diatrizoate, iohexol, or saline were studied in male rats pretreated with steroids or saline. Using urinary albumin, glucose, sodium, and the enzymes lactate dehydrogenase (LDH), gamma-glutamyltransferase (GGT), and N-acetyl-beta-D-glucosaminidase (NAG) as markers of glomerular and tubular function, it was found that diatrizoate caused temporary glomerular and tubular dysfunction; the effect was independent of the kind of pretreatment. Iohexol did not cause increased glomerular permeability in steroid- and saline-pretreated rats. When used following saline, iohexol induced increased excretion of three tubular components, whereas iohexol plus steroids caused increased excretion of all five tubular components. The dysfunctional effect of iohexol plus steroids was less than that of diatrizoate plus steroids. The serum components revealed no abnormalities induced by either contrast media or methylprednisolone. Pretreatment with steroids has no effect on the glomerular or tubular dysfunctional effect of diatrizoate, whereas it worsens the temporary tubular dysfunctional effect of iohexol in rats.

Acetylglucosaminidase↗
PubMed1991

Effects of selective beta 2-adrenoceptor blockade on serum potassium and exercise performance in normal men.

1. The differential effects of beta-adrenoceptor subtypes on potassium fluxes and exercise capacity were compared in eight healthy young men using single oral doses of the selective beta 2-adrenoceptor antagonist ICI-118551, the selective beta 1-adrenoceptor antagonist atenolol or the non-selective beta-adrenoceptor antagonist propranolol. The study was randomized, double-blind and placebo controlled. 2. Potassium in the venous effluent from the exercising muscles increased progressively with increasing exercise intensity. This response was augmented by propranolol, whereas neither atenolol nor ICI-118551 modified the response. After exercise potassium concentration fell exponentially with no difference between the treatment regimens. 3. Cumulative work was significantly reduced by ICI-118551 (6.4%, P = 0.04) and by propranolol (12.4%, P less than 0.01), whereas the reduction with atenolol (5.6%) did not reach statistical significance. 4. Atenolol and propranolol reduced peak heart rate by 23% and 29%, and peak systolic blood pressure by 9% and 11% respectively during maximal exercise. ICI-118551 caused a non-significant reduction in heart rate during submaximal exercise, with a significant reduction at maximum exercise (6% reduction), whereas systolic blood pressure was not different from placebo. Diastolic blood pressures were similar across all treatment regimens. 5. Similar glucose concentrations were obtained at baseline and at exhaustion during all treatment regimens. Lactate concentrations were comparable for any given exercise intensity irrespective of treatment regimens. Propranolol reduced lactate concentrations from the exercising muscles at maximum exercise in proportion to the reduction of maximal exercise capacity. 6. The subjective perception of fatigue was not affected by either beta 1- or beta 2-adrenoceptor blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1991

Islet cell cytoplasmic antibodies (ICA) in diabetes and disorders of glucose tolerance.

Islet cell cytoplasmic antibodies were determined in 85 individuals 60 to 74 years old with fasting hyperglycaemia, in 65 patients with cystic fibrosis, in 113 patients with pancreatitis, in 21 patients with Turner's phenotype, and in 135 first-degree relatives of patients with Type 1 (insulin-dependent) diabetes. Islet cell antibodies were absent in all 60 to 74-year-old subjects with fasting hyperglycaemia detected by screening, and who did not require insulin treatment within 3 years. Islet cell antibodies were also absent in all patients with pancreatitis, cystic fibrosis, or Turner's phenotype. Islet cell antibodies were detected in 2 out of 135 (1.5%) first-degree relatives of new Type 1 diabetic patients, and in 1 out of 371 (0.3%) non-diabetic control subjects. During 12 years of follow-up 1 of the 2 first-degree relatives with islet cell antibodies and the only positive control developed Type 1 diabetes. It is suggested that islet cell antibodies are primarily associated with Type 1 diabetes and not with other disorders of glucose tolerance.

Acute Disease↗
PubMed1991

Feeding problems, height and weight in different groups of disabled children.

Two hundred and twenty-one disabled children from seven diagnostic groups have been examined with respect to height, weight and prevalence of four different feeding problems. Retarded growth and feeding problems were common in children with cerebral palsy, mental retardation, congenital heart disease and deaf-blindness, but rare in children with esophagus atresia, cystic fibrosis and epilepsy. Mean relative height and weight were significantly lower (p much less than 0.01) in children with mechanical feeding problems, such as impairment of self-feeding skills and oral-motor dysfunction, than in children without these problems, regardless of diagnostic group. Mean relative weight was also significantly lower in children with poor appetite than in children with good appetite. Feeding problems contribute to short stature and underweight in severely disabled children.

Adolescent↗
PubMed1991

Cellular inflammatory infiltrates and renal cell turnover in kidney allografts: a study using in situ hybridization and combined in situ hybridization and immunohistochemistry with a Y-chromosome-specific DNA probe and monoclonal antibodies.

The generation and targeting of inflammatory cells in acutely rejecting kidney allografts are only partly understood. In order to investigate the origin of infiltrating mononuclear cells and the renal cell turnover, percutaneous renal biopsies (45) and lost renal allografts (4) from 40 sex-mismatched transplant patients clinically suspected of developing acute rejection were analysed by in situ hybridization (ISH) and combined ISH and immunohistochemistry (IMH). A biotinylated Y-chromosome-specific DNA probe was used for ISH. Monoclonal antibodies against leukocytes (leukocyte common antigen (CD45), T lymphocytes (CD43), B lymphocytes (L26) and myeloid/histiocytic cells (mac 387] were employed using a three-stage immunoperoxidase technique followed by ISH on the same specimens. The ISH method was very sensitive when differentiating male from female cells (p less than 0.01). Posttransplant mononuclear infiltrates were shown to be of recipient origin and dominated by T lymphocytes and myeloid/histiocytic cells. Tubular and glomerular cells remained of donor origin even after 10 months. There was no evidence of revascularization by recipient endothelial cells.

Antibodies, Monoclonal↗
PubMed1991

Cyclosporine-induced renal morphologic and immunohistologic changes in patients with chronic uveitis.

Ten long-term cyclosporine-treated patients with chronic uveitis underwent percutaneous renal biopsy in order to evaluate a) abnormalities of renal morphology and b) the nature of lymphocytic infiltrates by immunohistochemistry. Pretransplant renal biopsies from eleven cadaveric donors served as controls. Eight of the ten patients had lymphocytic infiltrates consisting predominantly of T lymphocytes with a CD4+/CD8+ ratio of 1.46, which is identical to that of peripheral blood in healthy donors. Evidence of immune activation as estimated by the presence of interleukin-2 receptors, transferrin receptors or by the expression of MHC class II antigens was not demonstrated in any of the patients. The severity of morphologic alterations did not correlate with any of the clinical or paraclinical data. Percutaneous renal biopsy should be performed within 18 months of treatment to identify patients susceptible to renal side effects of cyclosporine.

Adult↗
PubMed1991

Potential for thermophilic (50 degrees C) anaerobic dechlorination of pentachlorophenol in different ecosystems.

Thermophilic (50 degrees C) anaerobic biodegradation of pentachlorophenol (PCP) was investigated by using different inocula from natural ecosystems and anaerobic digesters. The inocula tested were three freshwater sediments, four anaerobic sewage sludge samples from digesters treating sludge from wastewater plants with various industrial inputs, and digested manure from an anaerobic reactor. Only one digested-sludge sample and the manure sample were from thermophilic environments. The initial PCP concentration was 7.5 or 37.5 microM. After 8 months, PCP had disappeared from the sediment samples and various, less chlorinated intermediates were present. Additions of extra PCP were degraded within 4 weeks, and a maximal observed dechlorination rate of 1.61 mumol/liter/day in the vials with addition of 7.5 microM PCP and 7.50 mumol/liter/day in the vials with addition of 37.5 microM PCP were measured for a freshwater sediment. In contrast, only 2.8 to 17.5% of the initial PCP added had disappeared from the sludge samples after 8 months of incubation. The complex pattern of intermediates formed indicated that the dechlorination of PCP proceeded via different pathways, involving at least two different populations in the dechlorination processes.

Anaerobiosis↗
PubMed1991

Height reduction in 539 tall girls treated with three different dosages of ethinyloestradiol.

During the period 1970 to 1985, 539 constitutionally tall girls were treated with ethinyloestradiol in varying dosages to reduce final height. They all had a predicted final height above 181 cm (greater than +2.5 SD). The girls were all healthy and were treated with three different dosages of ethinyloestradiol. Throughout these 15 years recommended treatment regimens changed, and the treatments described followed these guidelines. Girls in group 1 (n = 263) were treated with 0.5 mg of ethinyloestradiol, group 2 (n = 178) with 0.25 mg, and group 3 (n = 98) with 0.1 mg. The total mean (SEM) reduction of final height was 5.9 (0.2), 5.3 (0.1), and 4.4 (0.2) cm when treated with 0.5, 0.25, and 0.1 mg respectively. Group 1 was treated for 2.02 (0.03) years and group 2 and 3 for 1.85 (0.04) and 1.63 (0.05) years respectively. When expressed in relation to the treatment period the reduction of final height was 3.0 (0.1), 3.1 (0.1), and 2.9 (0.2) cm/year of treatment respectively. All the girls were treated with ethinyloestradiol as a daily single dose, while progestogen was given daily the first 10 days of every month. In conclusion we found that a daily dose of ethinyloestradiol 0.1 mg for about 20 months is sufficient to reduce final height. We recommend starting treatment at a bone age of about 12 years.

Adolescent↗
PubMed1991

The effect of insulin withdrawal on intermediary metabolism in patients with diabetes secondary to chronic pancreatitis.

Insulin was withdrawn from 7 patients with Type I (insulin-dependent) diabetes and 4 patients with insulin-dependent diabetes secondary to chronic pancreatitis, both groups without residual beta-cell function. Median plasma glucagon concentrations rose slightly, but significantly after withdrawal of insulin in Type I diabetic patients (from 14 (range: 11-16) to 19 (14-25) pmol/l by 6 h), but not in the patients with secondary diabetes. This was accompanied by a significantly higher increase in blood glucose concentration from 5.1 (4.9-5.7) to 15.2 (12.9-18.1) mmol/l by 6 h in Type I diabetic patients compared with patients with secondary diabetes (from 4.9 (4.3-6.7) to 13.1 (10.9-13.5) mmol/l) (p less than 0.01). Beta-hydroxybutyrate increased to a similar extent in the two groups, whereas no significant increases were found in glycerol and lactate in any of the groups. Increased secretion of glucagon is not essential for the development of hyperglycemia and ketonemia in patients with diabetes secondary to chronic pancreatitis, but may augment the degree of hyperglycemia in Type I diabetic patients compared with patients having secondary diabetes.

3-Hydroxybutyric Acid↗
PubMed1991

Evaluation of symphysis-fundus measurements and weighing during pregnancy.

To evaluate the value of using symphysis-fundus (SF) distance and maternal weight gain measurements in predicting an infant's birth weight, these measurements were analysed in 831 single-birth deliveries at Aker University Hospital during a period of 3 months. Of the 96 babies with a birth weight below the 10th percentile for gestational age, 39 (41%) could be detected by a series of SF-measurements. For every third correctly identified SGA (small for gestational age) baby, there were 7 false positive predictions. Only 13 (14%) of the mothers who gave birth to SGA babies demonstrated a weight gain at each medical check-up during pregnancy, whereas 197 (30%) of the women giving birth to normal-weight babies showed a weight gain each time (p = 0.02). However, for maternal weight gain, both predictive value (14%) and specificity (29%) were low. Hence, these two screening methods for the detection of SGA babies remain imprecise in practice. Test procedures should be improved, and factors influencing fetal growth should be emphasized to detect fetuses at risk.

Birth Weight↗
PubMed1991

The multi-crossover model for classifying patients as responders to a given treatment.

The strength and the validity of the multi-crossover model (MCO model) were investigated to optimalize the procedure for correctly classifying individual responders to a given therapy. One hundred and fifteen patients with non-ulcer dyspepsia from seven Norwegian hospitals were included in a 6-week double-blind MCO-designed trial with alternating weekly treatments with ranitidine and placebo. An individual effect score (X score) was calculated on the basis of the number of times the active drug was associated with less symptoms than the preceding or following placebo period. Patients categorized as responders (X score greater than or equal to 4) or unclassifiables (X scores = 2 or 3) after the MCO period continued single-blind active treatment for 4 weeks and were then reclassified by means of cross-tabulation of efficacy and adverse effects. Eighty-five per cent of the MCO responders and 62% of the 42 MCO unclassifiables were reclassified as responders. The reclassified responders were then included in a single-blind follow-up placebo period until relapse or for a maximum of 8 weeks. The relapse rate was significantly greater (p less than 0.01) and the time to relapse significantly shorter (p less than 0.01) in the group of MCO responders than in the MCO unclassifiables. The large response and relapse rates in the group of MCO responders verify that the MCO model is a reliable method for correctly classifying responders to treatment. Our results indicate that by including patients with an X score of 3 in the definition of 'responder', the MCO model could be modified to optimalize the procedure for correct classification.

Clinical Trials as Topic↗
PubMed1991

Ranitidine for non-ulcer dyspepsia. A clinical study of the symptomatic effect of ranitidine and a classification and characterization of the responders to treatment.

Seven Norwegian centres recruited 61 female and 54 male patients with non-ulcer dyspepsia (NUD). Their mean age was 40 years. After 6 weeks' double-blind alternating treatment with 150 mg ranitidine twice daily and placebo, 1 week of each alternative (part I), an effect score (Xs) and an efficacy index (Ei) were calculated. Ranitidine was significantly superior to placebo for symptomatic relief (p less than 0.01). Twenty-eight, 49, and 38 patients were Xs-classified as 'responders', 'unclassified', and 'nonresponders' to ranitidine, respectively. The symptomatic effect was impressive in the responder group and moderate but significant also in the unclassified group. The nonresponders had a significantly unfavourable effect of ranitidine compared with placebo. The Xs-classified responders and unclassified continued single-blind treatment with ranitidine for 4 weeks (part II) and were reclassified as 'new responders/nonresponders'. The new responders received single-blind treatment with placebo until relapse or maximum 8 weeks (part III). Parts II and III verified the good Xs classification of responders to ranitidine treatment. The overall effect of ranitidine in patients with NUD was due to good symptomatic effect in a subpopulation characterized by meal-related heartburn and/or regurgitation, large body mass index, first-degree relatives with gastrointestinal diseases, a relatively low frequency of gastrointestinal symptoms per week, and absence of soft stools.

Adult↗
PubMed1991

Flush perfusion of rabbit kidneys with autogeneic, allogeneic and xenogeneic blood.

A simple perfusion model was developed to study the events that lead to rejection of renal xenografts. Flush perfusion of the kidneys of 24 rabbits was carried out with blood from rabbits, cats, or humans. Light microscopy showed alterations with neutrophilic granulocytes margination of the vessels after only 15 min of perfusion. In the experiments with human blood the immunofluorescence microscopy showed deposits of immunoglobulins and complement factor III. This simple method is therefore a useful way of studying perfusion in renal xenografts.

Animals↗
PubMed1991

Energy and nutrient intakes of disabled children: do feeding problems make a difference?

We examined the effect of feeding problems and alternative feeding practices on the energy and nutrient intakes of disabled children. Subjects were 221 disabled children aged 1 to 16 years from seven diagnostic groups: a 4-day food record was obtained for 166 children. The children's energy and nutrient intakes were examined in relation to the presence or absence of four feeding problems (gross motor/self-feeding impairment, oral-motor dysfunction, lack of appetite, food aversions) and two alternate feeding practices (prolonged assisted feeding and use of pureed foods). Cross-sectional analyses showed that children with feeding problems or alternative feeding practices had lower energy and nutrient intakes than did children without these factors. The presence of oral-motor dysfunction or prolonged assisted feeding significantly reduced relative energy intake. In general, differences in energy and nutrient intakes between children with and without other feeding problems or practices were small, and few statistically significant differences were found. The findings indicate that some feeding problems may reduce food intake in disabled children, although this effect is lessened by the conscientious efforts of parents. Parents and families of disabled children should receive dietary counseling to prevent deteriorative effects on the physical growth and health of children with long-standing feeding problems.

Adolescent↗
PubMed1990

[Porphyria variegata--the first case in Norway].

In Norway, the most common porphyrias are acute intermittent porphyria and porphyria cutanea tarda. We describe the first case of porphyria variegata in this country. The patient showed symptoms of the skin and had no abdominal discomfort. Her family was also evaluated and two other persons were found with suspected latent porphyria variegata. We discuss the main symptoms of this type of porphyria and the possibilities of treatment. We emphasize that examination of porphyrins in the feces of patients with porphyria variegata is essential for the diagnosis.

Humans↗