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Biomedical subjects

B F Hansen

Publications and source records attributed to B F Hansen.

At least 55 records · Page 3Linked to original sources
PubMed1996

Wortmannin inhibits both insulin- and contraction-stimulated glucose uptake and transport in rat skeletal muscle.

The role of phosphatidylinositol (PI) 3-kinase for insulin- and contraction-stimulated muscle glucose transport was investigated in rat skeletal muscle perfused with a cell-free perfusate. The insulin receptor substrate-1-associated PI 3-kinase activity was increased sixfold upon insulin stimulation but was unaffected by contractions. In addition, the insulin-stimulated PI 3-kinase activity and muscle glucose uptake and transport in individual muscles were dose-dependently inhibited by wortmannin with one-half maximal inhibition values of approximately 10 nM and total inhibition at 1 microM. This concentration of wortmannin also decreased the contraction-stimulated glucose transport and uptake by approximately 30-70% without confounding effects on contractility or on muscle ATP and phosphocreatine concentrations. At higher concentrations (3 and 10 microM), wortmannin completely blocked the contraction-stimulated glucose uptake but also decreased the contractility. In conclusion, inhibition of PI 3-kinase with wortmannin in skeletal muscle coincides with inhibition of insulin-stimulated glucose uptake and transport. Furthermore, in contrast to recent findings in incubated muscle, wortmannin also inhibited contraction-stimulated glucose uptake and transport. The inhibitory effect of wortmannin on contraction-stimulated glucose uptake may be independent of PI 3-kinase activity or due to inhibition of a subfraction of PI 3-kinase with low sensitivity to wortmannin.

1-Phosphatidylinositol 4-Kinase↗
PubMed1996

Caries experience of 35-year-old Oslo residents and changes over a 20-year period.

The dental health of 35-year-old Oslo citizens was investigated in cross-sectional studies applying similar methods in 1973, 1984 and 1993. In the 1993 investigation, a clinical and radiographic examination of dental caries was performed on 121 randomly selected individuals (response rate 68 per cent). DMFT/S scores were used for recording caries experience. Carious surfaces (DS) were related to independent variables organised under the four main categories of health field concept; environment, behaviour, biology and health care. Mean DMFS based on 28 teeth was 40.9 in 1993, compared to 66.5 in 1984 and 68.2 in 1973. DS, MS, FS and DMF values were significantly lower in 1993 compared with those from the previous 1973 and 1984 studies, while only minor differences were detected from 1973 to 1984. High numbers of decayed surfaces (DS) were significantly associated with poor oral hygiene, unsatisfactory economic status and irregular dental visiting habits. The most influential independent variables explained 35 per cent of the variance in carious surfaces (DS).

Adult↗
PubMed1995

Relative importance of ischemic injury and immunological injury on the development of transplant arteriosclerosis in rabbit aortic allografts.

The development of transplant arteriosclerosis has emerged as a major problem to long-term survival after heart transplantation. The accelerated development of arteriosclerosis in the transplanted arteries, including the aorta, could result either from an ischemic injury in connection with the transplantation, or from an immunological reaction against the transplant, or both. We evaluated histologically and biochemically whether extension of the ischemic period from 1 to 24 hr has any influence on the development of transplant arteriosclerosis, in aorta-allografted rabbits clamped at human levels of plasma cholesterol. One set of rabbits was without immunosuppressive treatment (n = 10 + 9) and another otherwise identical set of rabbits received cyclosporine to achieve blood cyclosporine levels in the human therapeutic range (n = 10 + 12). The number of T lymphocytes in intima suggested that, in the grafts from untreated animals, an immunological injury had arisen, which cyclosporine reduced. A clear trend toward a worsening of the transplant arteriosclerosis was demonstrated as a function of the severity of the ischemic injury, both with and without immunosuppressive treatment. However, the worsening effect of maximal ischemic injury was less than that due to maximal immunological injury. In grafts from cyclosporine-treated animals, the development of transplant arteriosclerosis was significantly less than in grafts from untreated animals exposed to identical periods of ischemia. These results suggest that compared with immunological injury, ischemic injury is of minor importance for the development of experimental transplant arteriosclerosis.

Animals↗
PubMed1995

Effect of oestrogen replacement therapy on development of experimental arteriosclerosis: a study in transplanted and balloon-injured rabbit aortas.

The mechanism underlying possible protection of oestrogen replacement therapy against cardiovascular disease appears to go beyond beneficial changes in plasma lipoproteins. A direct action of oestrogen on the metabolism of lipoproteins after entering the arterial wall may occur. The present study evaluated whether oestrogen replacement therapy affects the development of experimental arteriosclerosis in immunologically injured (experiment A + B) and balloon-injured (experiment B) aortas in ovariectomized rabbits maintained at a human level of plasma cholesterol; both models involve severe damage to the endothelium with resulting rapid accumulation of lipoproteins in the arterial intima and therefore appear suitable for studying factors directly affecting subendothelial lipoprotein metabolism. In experiment A, dietary cholesterol required to maintain a human level of plasma cholesterol was significantly higher for the oestrogen group than for the placebo group. Similarly, cholesterol accumulation in the aortic grafts was borderline higher for the oestrogen than the placebo group, whilst intimal hyperplasia was without difference between the groups. Due to a modified schedule of cholesterol feeding in experiment B, oestrogen and placebo groups received the same amount of dietary cholesterol, and cholesterol accumulation and intimal hyperplasia were similar in immunologically injured and balloon-injured parts of the aorta in both groups. These results suggest that in the female rabbit maintained at a human level of plasma cholesterol, oestrogen replacement therapy has no direct action on the development of experimental arteriosclerosis when induced by immunological or mechanical injury to the endothelium.

Animals↗
PubMed1995

Effect of the antioxidant probucol on transplant arteriosclerosis in aorta-allografted rabbits.

The attenuation of atherogenesis by oral probucol treatment, demonstrated in several animal studies, has been attributed to the antioxidative property of probucol. It is thought that probucol, by inhibiting oxidation of low density lipoproteins (LDL) decreases the uptake of LDL into monocytes, and thereby reduces the development of foam cells and fatty streaks. Also, the neointimal proliferation seen after balloon injury has been attenuated by treatment with probucol. Since foam cells and neointimal proliferation are both important elements of transplant arteriosclerosis, we have investigated whether probucol might also retard the development of experimental transplant arteriosclerosis. The thoracic aorta from one rabbit was transplanted as a bypass graft onto the abdominal aorta of another rabbit. Nine rabbits were treated with 1 g probucol per day and seven animals were treated with vehicle. After a recovery period of 2 weeks, all rabbits were clamped at a human level of plasma cholesterol (6 to 7 mmol/l) for a period of 3 weeks. The amount of dietary cholesterol necessary for this clamping tended to be higher in probucol treated than in vehicle-treated rabbits. The distribution of plasma cholesterol between lipoprotein classes was similar in the two groups, except for the concentration of high density lipoproteins (HDL), which was significantly lowered by probucol. Probucol markedly decreased the susceptibility of LDL and intermediate density lipoprotein plus very low density lipoprotein (IDL + VLDL) particles to oxidation, as measured by the production of conjugated dienes when adding Cu2+. Despite this, the development of transplant arteriosclerosis as well as the number of macrophages in the neointima were not significantly different in the aortic allografts from the two groups. These results suggest that antioxidative agents do not retard the development of experimental transplant arteriosclerosis.

Animals↗
PubMed1995

(-)-anipamil retards atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Calcium antagonists have been reported to limit atherosclerosis in cholesterol fed rabbits. The purpose of this study was to examine the effect of the calcium antagonist (-)-anipamil on the spontaneous development of atherosclerosis in homozygote WHHL rabbits. From the age of 7 weeks, three groups of rabbits received 0 (control, n = 11), 1 mg/kg body weight (n = 11), or 10 mg/kg body weight (n = 12) of (-)-anipamil for 17 weeks. Serum cholesterol at start of the investigation was 18.8 +/- 1.2 (mean +/- SEM), 20.5 +/- 1.8, and 19.5 +/- 0.8 mM, respectively, in the three groups. No significant differences were found in serum lipids (i.e., VLDL, IDL, LDL, HDL) in the study period among the three groups. Plasma anipamil at the end of the study was 0.23 +/- 6, and 202 +/- 19 ng/ml, respectively, in the three treatment groups. The degree of atherosclerosis in the abdominal aorta was significantly lower (p < 0.02) in the 10 mg/kg body weight (-)-anipamil group compared with the two other groups. No significant difference was found in the thoracic aorta. It is concluded that (-)-anipamil retards development of atherosclerosis in the abdominal aorta in WHHL rabbits.

Animals↗
PubMed1995

Changes in endodontic status 1973-1993 among 35-year-olds in Oslo, Norway.

Epidemiological investigations from Scandinavia have documented high prevalence of apical periodontitis and inferior quality and results of endodontic treatment performed in general practice. The present investigation is part of a 20-year follow-up study on oral health in 35-year-old Oslo citizens focusing on endodontic conditions. The results indicate reduced prevalence of apical periodontitis and statistically significant improvement in endodontic status compared with results from a similar study performed in 1984.

Adult↗
PubMed1995

Tetracycline-resistant micro-organisms recovered from patients with refractory periodontal disease.

Tetracycline in combination with scaling and root planing is frequently used to treat refractory periodontal disease. This study examined tetracycline resistance in bacteria recovered from periodontal pockets of patients with refractory periodontitis. Bacterial isolates resistant to 10 micrograms/ml of tetracycline were isolated from plaque samples of 17 patients, of whom 6 had received tetracycline within 8 weeks prior to sampling. Minimal inhibitory concentrations (MICs) of tetracycline and minocycline were determined by agar dilution. In the 6 patients who had received tetracycline, a mean of 22.9% (+/- 38.2) of the total cultivable subgingival flora were resistant to tetracycline, compared with a mean of 7.2% (+/- 8.5) in the untreated group. Although various organisms were isolated, in most patients, the tetracycline-resistant organisms were dominated by Streptococcus spp. Overgrowth of Candida was found in one patient, and of Enterobacteriaceae in another patient, while small numbers of yeast or Staphylococcus spp. were isolated from the plaque samples of 9 others. 3 out of 4 patients who did not respond to tetracycline treatment had a variety of tetracycline-resistant anaerobic Gram-negative rods present. No correlation was found between increased proportions of tetracycline resistance in the whole bacterial sample and the presence of resistant periodontal pathogens.

Adult↗
PubMed1995

Changes in periodontal treatment needs. A follow-up study of Oslo citizens from the ages of 35 to 50 years.

A random sample of 35-year-old subjects from Oslo took part in a dental survey in 1973 and were re-examined in 1988. Eighty-one subjects (85%) attended the final examination. The need for periodontal treatment was assessed by the Periodontal Treatment Need System (PTNS), and the oral hygiene by the Simplified Oral Hygiene Index (OHI-S). The participants attended a structured interview and answered a questionnaire about general and dental health habits as well as psycho-social factors. Only small changes in the distribution of subjects in the different PTNS categories were found to have taken place during the 15 years. In 1973, 56.8% were in need of scaling (Class B) and 32.1% had one or more deep inflamed pockets (Class C), and in 1988 the scores were 54.3% and 30.1% respectively. A logistic regression model was used to study the associations between risk factors and increased treatment need, as expressed by increase in the number of C-quadrants. Increased number of C-quadrants was positively associated both with short duration of education and with no interdental cleaning. Using a socio-ecological model for periodontal diseases, variables describing the items "behaviour" and "environment" were found to be most closely associated with increased need for periodontal treatment.

Adult↗
PubMed1995

Prevalence of radiographic alveolar bone loss in young adults, a multinational study.

In a multinational study of alveolar bone loss, bite-wing radiographs of 8,703, 15-17-year-old adolescents from 18 centres in 16 countries were examined. Of these, 13 per cent were excluded as non-informative because of bad quality radiographs or missing first molars. Bone loss was a common finding globally (mean prevalence rate of subjects with bone loss 10.2 per cent), although there were great geographical variations. The bone loss was mostly horizontal, infrabony lesions were rare. The most frequently affected sites were the mesial aspects of the first maxillary molars followed by the distal aspects of the same teeth. Twenty-three subjects from the Finnish bite-wing study were examined for clinical conditions. When subjects with and without radiographic bone loss were compared, no statistically significant differences in the mean Gingival Index were found. The subjects were re-examined 5 years later. The gingival condition and the oral hygiene tended to be better at the end of the period than they had been at the start, but it was only in males that the differences were statistically significant. Periodontal destruction cannot be predicted from the gingival condition, but bite-wing radiographs of adolescents seem to be a valuable diagnostic tool for early detection of periodontal bone loss.

Adolescent↗
PubMed1994

[AIDS and heart disease].

This article reviews cardiac manifestations of AIDS in terms of etiology, pathogenesis, pathoanatomic lesions and heart function. Hypothetically the prevalence of myocarditis and disperse fibrosis of the myocardium are correlated to increasing rates of dilated cardiomyopathy and cardiac insufficiency. Echocardiography has proved to be of value in detecting early abnormalities and should be recommended on broad indications, though aggressive therapy of cardiac abnormalities is of importance to ensure quality of life and surveillance for the patients.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Gastrin and somatostatin in Helicobacter pylori infected antral mucosa.

Helicobacter pylori infection is associated with increased meal stimulated gastrin secretion, but the reason for this is unknown. Sequence specific radioimmunoassays were used to measure the concentration of alpha-amidated gastrin, the total progastrin product, and somatostatin in biopsy specimens of human antral mucosa. The antral concentrations of alpha-amidated gastrin and of total progastrin products were significantly higher in H pylori infected patients than in those not infected by this organism. In contrast, the antral somatostatin concentration was significantly decreased in infected patients. Progastrin processing, determined by gel chromatography, seemed unaffected by H pylori infection. The results suggest that the finding of increased gastrin secretion from the antral G cells in H pylori infected patients may be a result of reduced inhibition of G-cell secretion by somatostatin.

Adult↗
PubMed1994

Cyclosporin suppresses transplant arteriosclerosis in the aorta-allografted, cholesterol-clamped rabbit. Suppression preceded by decrease in arterial lipoprotein permeability.

The immunosuppressant cyclosporin has been suggested to aggravate as well as retard the development of transplant arteriosclerosis, the major long-term problem for patients with heart transplants. We examined the effect of human therapeutic levels of blood cyclosporin on the development of experimental transplant arteriosclerosis. The thoracic aorta from one rabbit was transplanted as an end-to-side bypass on the abdominal aorta of another rabbit, and plasma cholesterol was clamped at 5 to 7 mmol/L. Cyclosporin markedly suppressed the severity of transplant arteriosclerosis, judged both biochemically and histologically: cholesterol content in aortic transplants was reduced by 70% and 80% after 10 days and 20 days of cholesterol feeding, respectively (both comparisons, P < .01), and after 20 days of cholesterol feeding myointimal proliferation was totally inhibited in grafts from cyclosporin-treated animals, judged from maximal intimal thickness and intimal area on cross sections of grafts (both comparisons, P < .05). In another group of non-cholesterol-fed, aorta-transplanted rabbits, cyclosporin reduced by 90% (P < .01) an otherwise markedly increased permeability to low-density lipoprotein in transplanted aortas. These results suggest that cyclosporin causes a substantial decrease in the severity of transplant arteriosclerosis and that this effect is mediated at least partly via a large decrease in aortic lipoprotein permeability.

Animals↗
PubMed1994

Atherosclerosis in Watanabe heritable hyperlipidaemic rabbits. Evaluation by macroscopic, microscopic and biochemical methods and comparison of atherosclerosis variables.

The spontaneous development of atherosclerotic disease in 38 homozygous and 34 heterozygous Watanabe heritable hyperlipidaemic rabbits was evaluated by qualitative and quantitative light microscopy in aorta, coronary, pulmonary and renal arteries, by naked eye and macroscopic morphometric estimation of aortic atherosclerosis extent and by biochemical analysis of aortic cholesterol content. No noteworthy atherosclerosis was demonstrated within 19 months in heterozygous rabbits. In homozygous rabbits, atherosclerotic lesions were seen from the age of 4 months and progressed with age. All 19-month-old rabbits had severe atherosclerotic disease. As much as 64% of the variation in atherosclerosis extent/severity could be explained by serum cholesterol and age. A highly significant correlation between the various methods for quantitation of atherosclerosis extent and/or severity was demonstrated, suggesting that quantitative microscopy, macroscopic morphometry and determination of aortic cholesterol content may be equally valid as a measure of atherosclerosis in WHHL rabbits and are therefore interchangeable.

Animals↗
PubMed1993

A socio-ecologic model for periodontal diseases.

A socio-ecologic conceptual model for periodontal diseases has been proposed. The model, which includes 4 items: health-care organization, human biology, behavioral factors, and environment, has been tested on a random-sample of 50-year-old Oslo citizens. The investigation is based on a clinical examination as well as a questionnaire and structured interview. A logistic regression model was used to study associations between risk factors and the probability of deep periodontal pockets (> 5.5 mm). The risk of periodontal pockets was positively associated with: short duration of education, being of male gender, previous periodontal treatment, poor oral hygiene and infrequent toothbrushing. Variables describing behavioral factors and human biology were the items found to be most closely associated with periodontal pocketing.

Biology↗
PubMed1992

The influence of dietary olive oil and margarine on aortic cholesterol accumulation in cholesterol-fed rabbits maintained at similar plasma cholesterol level.

The present study compares the atherogenicity of a standard diet and diets with 10% olive oil or 10% margarine added, in rabbits maintained at a mean plasma cholesterol level of about 20 mM for 13 weeks. Each group consisted of 15 animals. The distribution of cholesterol in plasma between VLDL, IDL, LDL and HDL was similar in the 3 groups. The thoracic aortic cholesterol accumulation was 16.6 +/- 1.6, 11.4 +/- 1.0 (P < 0.05) and 12.6 +/- 1.7 (P > 0.05) nmol/mg wet weight for the group receiving standard diet, diet with 10% olive oil added and diet with 10% margarine added, respectively. There was no significant difference between groups in the occurrence of the atherosclerotic changes in the proximal and distal parts of coronary arteries, abdominal aorta and renal arteries. The occurrence of atherosclerotic changes in the pulmonary arteries was equal in the groups receiving standard diet and diet with 10% margarine added while it was significantly lower (P < 0.05) in the group receiving diet with 10% olive oil added. The atherosclerotic changes at the aortic orifice of coronary arteries were quanticated morphometrically and were most severe in the group on the standard diet. The results indicate a comparable atherogenic effect of 10% olive oil or margarine addition to standard diet on development of atherosclerosis in rabbits maintained at a similar plasma cholesterol level. The study also suggests that supplementation of olive oil or margarine to standard rabbit diet leads to lower cholesterol accumulation in the thoracic aorta compared with standard diet, an effect not modulated by changes in plasma cholesterol concentrations.

Animals↗
PubMed1992

Clinical responses to subgingival application of a metronidazole 25% gel compared to the effect of subgingival scaling in adult periodontitis.

A newly developed metronidazole 25% dental gel was compared with subgingival scaling in the treatment of adult periodontitis. 206 patients in 9 centres participated in the study. Probing pocket depth (PPD) and bleeding on probing (BOP) were recorded before treatment and 2, 6, 12, 18, and 24 weeks after the treatment. All patients had at least 1 tooth in each quadrant with a PPD of 5 mm or more. The treatments consisted of 2 applications of dental gel (days 0 and 7) in 2 randomly selected quadrants (split mouth design) and 2 sessions of subgingival scaling (1 quadrant on day 0, and 1 quadrant on day 7). Instruction in oral hygiene was given 2 weeks after completed treatment. The average PPD and the average frequency of BOP were calculated over all sites with initial PPD of 5 mm or more. PPD and BOP were thus, at each examination, calculated from the same sites. The mean PPD was 5.9 mm before gel application and 5.8 mm before scaling (p = 0.31). BOP was 88% in both treatment groups. 24 weeks after the treatment, PPD and BOP were significantly reduced in both groups and for both parameters (p < 0.01). PPD was reduced by 1.3 mm after gel application and 1.5 mm after scaling; BOP was reduced by 32% and 39%, respectively. The difference between the treatments was statistically significantly, but considered as clinically unimportant.

Adult↗