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Biomedical subjects

A Johansen

Publications and source records attributed to A Johansen.

At least 73 records · Page 4Linked to original sources
PubMed1989

Neoplasms of the central nervous system in Norway. IV. A population-based epidemiological study of meningiomas.

All 1632 cases of meningioma reported to the Norwegian Cancer Registry from 1955 to 1986 have been studied: a) 96% appeared in patients over 30 years of age, b) 95% were histologically benign, c) 88% were located intracranially, and d) 66% occurred in females. The female predominance manifested itself in the middle age period. Eighty-seven percent of the intraspinal meningiomas presented in females, but the ratio between intracranial and intraspinal meningiomas was significantly lower in females (5.4) than in males (20.4). Increased incidence rates of meningioma in females are revealed for the birth-cohorts after 1930. The reason for this change is unclear so both environmental and hormonal factors should be explored. Based upon the epidemiological data, it appears that female sex hormone(s) could act as a growth stimulus in the development of meningiomas, but are neither sufficient nor necessary for tumourigenesis.

Age Factors↗
PubMed1988

Optimal matching between canine left ventricle and afterload.

A parabolic relationship exists between ventricular external work and arterial load at given preload and contractility. Previous data indicate that the working point falls close to the parabola optimum. By combining the left ventricular (LV) end-systolic pressure-volume relationship (ESPVR) and an equation describing external stroke work, optimum values of stroke volume (SV), the slope (Emax) of the ESPVR, and arterial resistance (Rp) corresponding with the optimum (i.e., mSV, mEmax, mRp) were obtained. Experiments in anesthetized dogs were performed to test whether mSV, mEmax, and mRp also correspond to observed SV, Emax, and Rp at three different levels of volume load (right atrial pressure, RAP) before and after acute depression of LV contractility. Comparisons of observed and optimal values of SV, Emax, and Rp were made before and after LV depression. Before embolization, the ratios were SV/mSV 1.10-1.20 (RAP 5-15 mmHg); Emax/mEmax 1.21-1.41; and Rp/mRp 0.84-0.69. After LV depression, SV/mSV was 0.80-0.83, Emax/mEmax was 0.78-0.71, and Rp/mRp was 1.56-1.46. The ratios were all significantly changed (P less than 0.01) by the induced LV depression. The present analysis may offer a new tool to detect nonoptimal relations between cardiac and arterial functions.

Animals↗
PubMed1988

Risk factors of morbidity and mortality in surgically treated chronic aortic valvular heart disease.

A cohort of 617 patients underwent aortic valve replacement (AVR) the median follow-up time was 3.4 years with a range (0-7.8) years. The incidence of early mortality was 5.0% and the five years survival (77.9 +/- 1.9)%. Risk factors of early mortality and morbidity (Low Output Syndrome) occurring the first 31 days after operation were pinpointed. Another analysis was done to estimate independent predictors of late premature death from all causes, and from specific causes (cardiac related, sudden cardiac). One of the major late morbid events was the appearance of systemic emboli. Its rate was 1.4% pats. Year. Its risk factors were presence of pure aortic regurgitation and advanced age at operation. The relative survival rate was at 5 years of 87.0% for the total cohort, but for our younger patients (age less than 30 years), we reached 99.4%. Our results suggest more aggressive measures to correct the hazard in AVR, and impose carefulness in comparing quality of AVR from different institutions for mortality and morbidity. Finally the results of AVR are rather palliative than curative except for our younger patients where we reached curability.

Adult↗
PubMed1988

A case of thromboangiitis obliterans affecting coronary, pulmonary, and splenic vessels. Is thromboangiitis obliterans a generalized vascular disease?

We describe a 53 year old man who died following his 3rd myocardial infarction. Before death there were scintigraphic signs of infarctions in the lung and spleen. Postmortem examination revealed an occlussive vascular disease in coronary, pulmonary, and splenic vessels. The histological findings were consistent with thromboangiitis obliterans. We suggest that thromboangiitis obliterans probably is a generalized vascular disease.

Coronary Vessels↗
PubMed1987

Influence of the prostaglandin E1 analogue Rioprostil on the human gastric mucosa.

Ten healthy volunteers received the prostaglandin E1 analogue Rioprostil 300 micrograms b.i.d. for 1 week. Endoscopically obtained biopsies were investigated with tritiated thymidine and autoradiography to determine the rate of cell proliferation and with a texture-analyzing system to measure the intracellular amount of mucus in the epithelial cells. Rioprostil did not alter the tritiated thymidine labeling index in the antral area but did significantly depress it in the fundic area. The mucus content was unchanged in the antrum but was significantly increased in the fundus. These observations indicate that Rioprostil given orally causes an enhanced cell maturation in the fundic area as well as an increased intracellular mucus content. Rioprostil seems to have no influence on the human antral area.

Adult↗
PubMed1987

The effect of acetyl salicylic acid and indomethacin on cell proliferation kinetics in the human gastric mucosa.

To determine the effect of acetyl salicylic acid and Indomethacin on the rate of cell proliferation in the human gastric stomach, 6 healthy volunteers received daily 3 g of acetyl salicylic acid or 150 mg of indomethacin for one week in a double-blind crossover trial. Cell proliferation was assessed by means of tritiated thymidine and autoradiography. The labelling index did not change, indicating that cell proliferation to compensate for the exfoliation caused by ASA and indomethacin does not increase.

Adult↗
PubMed1987

Dysplasia in gastric mucosa: prognostic significance.

Forty-seven patients having dysplasia in biopsies from the gastric mucosa were subjected to re-investigation. Twenty-three patients were alive at follow-up and 14 underwent gastroscopy with removal of random biopsies. The median duration of observation was 39 months, range 10-63 months. Regression of the dysplasia was found in all patients; in nine there was normal mucosa without dysplastic alterations in the control biopsies, mild dysplasia was still present in five of the patients. Our results suggest that the incidental finding of mild or moderate dysplasia does not, per se, indicate the necessity of further control, whereas severe dysplasia indicates repeat gastroscopies with biopsies, as such epithelial changes can occur together with gastric carcinoma.

Adult↗
PubMed1986

The effect of contractility and preload on matching between the canine left ventricle and afterload.

We define matching between ventricle and afterload to imply that the ventricle is adapted to its afterload to yield maximum external work output. For the ventricle, this optimal adaption will depend on end-diastolic dimension, heart rate, and contractility. Because contractility is impaired during ventricular failure, we propose that the adaption between ventricle and load is not as good during failure as during normal conditions. According to our definition, this implies that during failure external work output is less than maximum. Ventricle-load matching is then not present, i.e., a mismatch exists between ventricle and load. This hypothesis was tested in a canine preparation in which arterial load of the left ventricle was varied from one beat to the next. Left ventricular depression was induced by injections of 50 micron microspheres into the left coronary bed. We observed left ventricular stroke volume and external work during afterload variations at three different preload levels before and after microembolization. Before embolization the control observations of work and stroke volume were positioned at the apex of parabolas relating work to stroke volume. After embolization, however, control observations fell down along the left limb of the parabolas. These observations were independent of preload. Thus this study, carried out in a preparation with the heart in situ, supports the idea that the normal left ventricle is matched to its load and demonstrates ventricle-load mismatch when the left ventricle is failing.

Animals↗
PubMed1986

Effect of cimetidine on gastric mucosal cell proliferation in man.

Seven duodenal ulcer patients were treated for 3 months with cimetidine. Before and after treatment endoscopic biopsy specimens were taken for autoradiographic estimation of cell proliferation in the gastric mucosa in the antral and fundic part of the stomach and from the duodenum. In all three areas the estimated labeling index was increased during medication with cimetidine. The increase in epithelial cell renewal may participate in the ulcer healing effect of cimetidine.

Adult↗