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Biomedical subjects

I Nordenfelt

Publications and source records attributed to I Nordenfelt.

At least 19 recordsLinked to original sources
PubMed1987

The transfer factor (diffusing capacity) as a predictor of hypoxaemia during exercise in restrictive and chronic obstructive pulmonary disease.

Thirty patients (17 with restrictive, eight with chronic obstructive pulmonary disease and five with combined pulmonary changes) were studied. Ordinary pulmonary function tests were made and in addition the transfer factor (diffusion capacity) was measured at rest and compared to the arterial oxygen tension at rest and during maximal exercise. There was a significant correlation (r = 0.89) between the transfer factor at rest and the oxygen tension during maximal exercise in both the patients with restrictive and those with obstructive lung disease, but no correlation was found between the transfer factor and the resting oxygen tension. Exercise induced hypoxaemia (PO2 less than 8-8.5 kPa) occurred in some patients and this could be predicted with an excellent sensitivity and specificity if a discrimination point for the transfer factor of 50 per cent of predicted or less was chosen. Determination of the transfer factor at rest is thus a good screening test for exertional hypoxaemia and can be used to select patients for exercise testing when the purpose is to detect hypoxaemia.

Adult↗
PubMed1987

Catecholamine release after physical exercise. A new provocative test for early diagnosis of pheochromocytoma in multiple endocrine neoplasia type 2.

A simple and practical provocative test is needed for early asymptomatic pheochromocytoma, which is a major risk for patients with multiple endocrine neoplasia type 2 (MEN-2). We measured plasma catecholamines before and after submaximal exercise in 26 MEN-2 gene carriers, eight of whom with asymptomatic pheochromocytoma, nine with medullary thyroid carcinoma and 10 after uni- or bilateral adrenalectomy. Seventeen clinically healthy individuals and 11 patients with neurovegetative lability and symptoms mimicking pheochromocytoma served as controls. Plasma adrenaline, noradrenaline and dopamine increased after exercise except for adrenaline after bilateral adrenalectomy. The post-exercise levels of adrenaline and the adrenaline/dopamine ratio were significantly higher in the pheochromocytoma patients compared to the healthy controls and the patients with neurovegetative lability, while the patients with medullary thyroid carcinoma represented an intermediate group with a high probability of developing adrenal tumors. The present method is a physiological test with a high sensitivity and specificity. It is practical and well suited for repeated examinations and seems to be of value for the detection of early pheochromocytoma in MEN-2 patients. Furthermore, the test could be used in the differential diagnosis between pheochromocytoma and neurovegetative lability.

Adrenal Gland Neoplasms↗
PubMed1985

Reference values for exercise tests with continuous increase in load.

Reference values for exercise tests with continuous increase in load are presented. The exercise tests were performed on an electrically braked bicycle ergometer by 188 randomly selected Swedes of both sexes who were between 20 and 79 years of age. The reference values are related to sex, age (in decades) and weight and classified in decreasing levels of exercise capacity. Reference values for systolic blood pressure at different work loads are also given.

Adult↗
PubMed1985

Effect of metoprolol on "non-specific" ST-segment and T-wave changes.

Metoprolol, a cardio-selective beta-adrenergic blocking agent, was studied in 25 patients to assess its effect on "non-specific" ST-segment and T-wave changes both at rest and during exercise. In two thirds of the patients with ST-T-abnormalities at rest, the changes disappeared completely after beta-blockade but reappeared during exercise in some of them. Only in 9 patients were the changes eliminated also during exercise implying that they were "functional", i.e., caused by increased sympathetic discharge. In those patients, where the ST-T-abnormalities were not affected at all by the beta-blockade, they were probably due to organic heart disease, whereas when they were reduced but not completely abolished, increased sympathetic tone as well as organic heart disease might be the cause. It is inferred that the diagnostic information is increased by studying the effect of beta-blockade not only at rest but also during exercise. Metoprolol seems to be well suited for the evaluation of "non-specific" ST-T-abnormalities, especially when non-selective beta-blockers should be avoided, e.g. in obstructive lung disease.

Adolescent↗
PubMed1984

Venous volume in offspring of hypertensive patients.

Twenty normotensive healthy male offspring of hypertensive patients were compared to 20 adequate controls regarding venous volume, the effect of ouabain on venous volume and signs of left ventricular hypertrophy. Among offspring there were slightly increased amplitudes in the orthogonal ECG as compared to controls but the differences were not statistically significant. Using a plethysmographic technique we found a significantly lower venous volume of the forearm in the offspring than in controls. There was, however, no effect of ouabain on the venous volume. The decreased venous distensibility among normotensive offspring might be an early manifestation of essential hypertension.

Adult↗
PubMed1982

Diagnosis of deep vein thrombosis with 99Tcm-plasmin.

The diagnostic efficiency of 99Tcm-plasmin test was evaluated by X-ray contrast phlebography in 110 consecutive patients with suspected deep vein thrombosis (DVT). The test was positive in 50 of 55 patients with DVT (sensitivity 91%) and negative in 18 of 55 without DVT (specificity 33%). The positive plasmin test in patients without DVT was in most cases due to another inflammatory process or a post-thrombotic state. The 99Tcm-plasmin test is a rapid and sensitive screening method for th diagnosis of DVT, but as it is based on comparison between the legs, it may be unreliable in cases of bilateral thrombosis. The low specificity makes it less valuable in patients with concomitant inflammatory disease or previous thrombosis in either leg. When the plasmin test is positive, the diagnosis of DVT should in most cases be confirmed by X-ray contrast phlebography.

Adult↗
PubMed1977

Effects of a new beta1-selective beta-blocker H 87/07 in angina pectoris.

The efficacy and toleration of a new beta1-selective beta-blocker, H 87/07, was compared with placebo in 33 patients with angina pectoris. The efficacy was evaluated using subjective assessments of attack rate and nitroglycerin consumption as well as objective assessments of exercise tolerance on a bicycle ergometer. H 87/07 significantly reduced the attack rate and the nitroglycerin consumption compared with placebo. The mean reduction amounted to 13 and 36% respectively. No significant differences were found between H 87/07 and placebo with regard to exercise tolerance. Due to high intrinsic stimulating activity (I.S.A.) H 87/07 altered the heart rate and blood pressure only slightly at rest but during exercise significant reductions were seen. Except for one patient who had cardiac decompensation on H 87/07 no side-effects of clinical importance were seen. No significant changes were seen with regard to the laboratory tests performed.

Adrenergic beta-Antagonists↗
PubMed1975

Diagnosis of ventricular septal defect in acute myocardial infarction without cardiac catheterization.

Five patients with acute myocardial infarction and a systolic murmur suggestive of ventricular septal rupture or mitral regurgitation have been examined by external vascular isotope dilution curves over the chest after i.v. injection of 125I-hippuran. In three patients these isotope dilution curves showed signs of left-to-right shunting of blood, and subsequent autopsy demonstrated the presence of ventricular septal defect. In two patients there was no sign of left-to-right shunting, and these patients recovered.

Aged↗