Search PubMed⌕ Search

Biomedical subjects

K E Pedersen

Publications and source records attributed to K E Pedersen.

At least 37 records · Page 2Linked to original sources
PubMed1991

Magnesium content of the human heart.

Although changes in the body's magnesium status have been linked to ischemic heart disease, sudden death and arrhythmia, there is as yet no recommended, established procedure for evaluation of magnesium homeostasis. We therefore explored the relationship between the magnesium content of the heart and that of serum, lymphocytes and skeletal muscle in 50 men undergoing cardiac surgery, using biopsies from the right auricula, right atrium and skeletal muscle and simultaneously drawn venous blood for measurement of lymphocyte and serum electrolyte concentration. Median magnesium values (mumol/g wet weight) were 7.42 (3.98-8.89) in skeletal muscle, 5.49 (3.44-7.66) in right auricula and 5.80 (2.60-7.53) in right atrium. The magnesium concentration in skeletal muscle was found to correlate with that in right auricula (r = 0.46, p less than 0.01) and right atrium (r = 0.43, p less than 0.01), whereas values in serum and lymphocytes showed no correlation with the heart's magnesium content. When myocardial biopsy is not available, skeletal muscle magnesium concentration seems to be the best predictor of the human myocardium's magnesium status.

Chlorides↗
PubMed1990

[Percutaneous transluminal coronary angioplasty in acute myocardial infarction].

The attitude towards the treatment of acute myocardial infarction is currently changing. As an example of one of the new methods, a successful case of acute percutaneous transluminal coronary angioplasty is presented. Which of the new therapeutic regimens provides the best prognosis is unknown, but considering the resources and the hitherto published studies, intravenous thrombolysis seems in general to be the most advantageous, while the others ought only to be used on special indications.

Adult↗
PubMed1990

PAF receptors in guinea-pig and human lung.

The autoradiographic distribution and density of specific binding sites for the PAF receptor antagonist [3H]-WEB 2086 was assessed in non-diseased and asthmatic human lung and in guinea-pig airway tissue. In general, only very low levels of specific binding were detected in these tissues with no evidence for PAF receptors in airway smooth muscle. Asthma does not appear to involve significantly increased airway PAF receptor expression.

Animals↗
PubMed1990

Sodium content and sodium efflux of mononuclear leucocytes from young subjects at increased risk of developing essential hypertension.

Mononuclear leucocytes were used as a cellular model for the in vitro measurements of volume, sodium and potassium content, sodium efflux rate constants and absolute sodium efflux in order to assess any cellular changes in young men at increased risk of developing essential hypertension, and to analyze whether any such changes were associated with borderline hypertension and/or heredity. Four groups of subjects were evaluated: 28 normotensive (NTO) and 20 borderline hypertensive (BHO) offspring of hypertensives, 12 borderline hypertensives with normotensive parents (BH) and 28 normotensive subjects with normotensive parents (NT). The cellular sodium/potassium contents of the four groups were not discernibly different. Ouabain insensitive sodium efflux rate constant and corresponding absolute efflux were significantly increased in offspring of hypertensives. Ouabain sensitive absolute sodium efflux was significantly increased in borderline hypertensives (BHO + BH) compared to normotensives (NT + NTO). These results indicate that leucocytes from subjects predisposed to hypertension possess an increased ouabain insensitive sodium transport mechanism and in subjects with borderline hypertension the sodium-potassium pump seems activated.

Adolescent↗
PubMed1989

Increased 22Na+-influx in lymphocytes from offspring of essential hypertensive patients.

Lymphocytes were used as a cellular model for the in vitro measurements of 22Na+-influx during sodium pump inhibition by ouabain. The measurements were made using lymphocytes from young men at increased risk of developing essential hypertension in order to assess any changes and to analyse whether any such changes were associated to borderline hypertension and/or heredity. Four groups were evaluated: 28 normotensive and 20 borderline hypertensive offspring of hypertensives, 12 borderline hypertensives and 28 normotensives with normotensive parents. 22Na+-influx was significantly increased in offspring of hypertensive parents especially in the normotensive offspring of hypertensive parents. The association between heredity and increased 22Na+-influx found by us in vitro may be caused by either an increased passive sodium-influx and/or an increased sodium-sodium exchange mechanism.

Adolescent↗
PubMed1989

Increased number of ouabain binding sites in lymphocytes from borderline hypertensives.

Lymphocytes were used as a cellular model for the in vitro measurements of maximal ouabain binding sites in order to assess any changes in young men at increased risk of developing essential hypertension, and to analyse whether any such changes were associated to borderline hypertension and/or heredity. Four groups were evaluated; 28 normotensive (NTO) and 20 borderline hypertensive (BHO) offspring of hypertensives. Twelve borderline hypertensives (BH) and 28 normotensive subjects (NT) with normotensive parents. The number of ouabain binding sites were significantly increased in the borderline hypertensives irrespective of heredity. The borderline hypertensives were heavier than the normotensives. A stepwise multiple regression model was therefore used in order to control confoundings by body mass index (BMI) and other factors such as age, gamma glutamyl transferase, 24 h sodium excretion, serum triglyceride, and serum cholesterol, which may influence the number of ouabain binding sites. Only BMI entered the stepwise model. These results indicate the presence of an increased number of sodium-potassium pumps in lymphocytes from borderline hypertensives. This difference may be attributed to the blood pressure disease or increased body mass.

Adolescent↗
PubMed1989

Lymphocytic sodium and potassium pump function in Bartter's syndrome.

Bartter's syndrome is characterized by chronic hypokalaemia, activation of the renin-angiotensin system and normal blood pressure. To investigate whether a generalized disturbance of sodium-potassium pump function might be of pathogenetic importance, lymphocytic sodium-potassium homeostasis was examined in 5 patients suffering from Bartter's syndrome. Two of the patients were treated with potassium chloride supplementation, the others were without medical treatment when studied. All were severely hypokalemic (serum potassium 2.8 +/- 0.24 mmol/l, mean +/- SEM). Lymphocyte sodium and potassium concentration (14.4 +/- 0.37 and 94.4 +/- 7.7 mmol/l, respectively), ouabain sensitive 22Na-efflux rate constant (2.68 +/- 0.25 h), and absolute ouabain sensitive efflux rate (38.16 +/- 4.2 mmol l-1 h) did not differ from matched controls. Ouabain binding capacity was 126 900 +/- 23 500 sites/cell in patients vs 50 400 +/- 17 900 in controls (p less than 0.05). In conclusion, patients with Bartter's syndrome may have an intrinsic abnormal pump function, characterized by an increased pump density and a low cation turn-over rate per pump unit.

Adult↗
PubMed1989

Changes in pure-tone thresholds in individuals aged 70-81: results from a longitudinal study.

The results of audiometric evaluation of 376 randomly selected men and women, 70 years old and born in 1901, are reported. The investigation is part of a large study on a gerontological population in which the original participants were tested again with pure-tone and speech audiometry at ages 75, 79 and 81. We also report audiometric results obtained at ages 70 and 75 from a second group, consisting of 297 men and women born in 1906. Hearing loss was most pronounced at higher frequencies for both sexes, and men had an average of 10 dB greater hearing loss at 8 kHz than women. The decrease in hearing threshold in men between the ages of 70 and 81 was more pronounced at 2 kHz (27 dB) than at 4 and 8 kHz (15 and 20 dB, respectively). The average hearing loss in women increased at a constant rate between the ages of 70 and 79 (15 dB), while between the ages of 79 and 81 the changes in pure-tone threshold was minimal. There were no significant differences in pure-tone thresholds for women born in 1901 when compared to those born in 1906 at the ages of 70 and 75. However, men born in 1906 had a more pronounced hearing loss at the age of 75 than those born in 1901.

Age Factors↗
PubMed1988

A case of multiple extra-adrenal pheochromocytomas.

A case report of a 37-year-old previously healthy man who contracted hypertension and insulin-dependent diabetes mellitus. Urinary catecholamine excretion was elevated. A total of nine benign pheochromocytomas with characteristic histological appearance were successfully removed. Most of the tumors were located extra-adrenally in the upper abdomen and in the pelvis. Two of the tumors were found in organ plexuses in the mesocolon sigmoideum and in the anterior wall of prostata. Because of asynchronous tumor growth a life-long follow-up is recommended.

Abdominal Neoplasms↗
PubMed1988

Sensitivity and specificity of audiological tests in patients with vertigo.

In patients with vertigo a comprehensive test battery has been used for localizing pathological processes responsible for the symptoms. Audiological tests have been an integral part of the otoneurological investigation. However, in many studies the diagnostic sharpness of psychoacoustic tests in the localization of specific disease in the cranial nerve system has been called in question. Other tests, such as stapedius reflex and auditory brainstem response, have been of increasing importance in the diagnostic set-up. The purpose of this paper is to present a survey of the literature regarding the position of audiological tests in otoneurology.

Acoustic Impedance Tests↗
PubMed1988

Alterations in sodium-potassium regulation in mononuclear leucocytes from young borderline hypertensive and offspring of hypertensive patients.

Membrane ion transports were investigated in lymphocytes from young normotensive and borderline hypertensive offspring with and without heredity for hypertension. Borderline hypertension per se was associated with an enhancement of sodium-potassium pump activity. Heredity per se was associated with increased sodium influx and ouabain-resistant sodium efflux.

Adolescent↗
PubMed1988

86Rubidium uptake in mononuclear leucocytes from young subjects at increased risk of developing essential hypertension.

This study was designed to assess any changes in mononuclear leucocytes from young men at increased risk of developing essential hypertension and to determine whether any changes found were associated with borderline hypertension and/or heredity. To this end we used mononuclear leucocytes as a cellular model for in vitro measurement of total 86rubidium uptake to give an index of sodium-potassium pump activity. Four groups of subjects were evaluated, 28 normotensive and 20 borderline hypertensive offspring of hypertensives, and 12 borderline hypertensives and 28 normotensives with normotensive parents. 86Rubidium uptake was significantly increased in the borderline hypertensive subjects, especially in the borderline hypertensive offspring of hypertensive patients. Our results indicate that the sodium-potassium pump is activated in mononuclear leucocytes from borderline hypertensives, and especially in those borderline hypertensives with at least one hypertensive parent. The latter group was also the group at greatest risk of developing essential hypertension.

Adolescent↗
PubMed1987

Volume, sodium content and sodium efflux of human mononucleated cells: characteristics and methodological problems.

New methods for determining the volume and sodium content of human mononucleated cells are presented and the kinetics of sodium efflux are characterized. Sodium efflux obeyed first-order kinetics with a half-life of about 9 min. The ouabain-sensitive sodium pump is responsible for about 60% of the total turnover of this cation. Reliable measurement of cell volume and sodium content requires pre-incubation at physiological conditions. Determination of sodium efflux should be based on the initial (less than 15 min) cellular delay of 22Na-activity in preloaded cells. In normal subjects (n = 34), mean cell volume was 635 +/- 138 nl/10(6) cells and sodium content averaged 14.6 +/- 2.8 mmol/l cell. Total and ouabain-sensitive efflux rate constants were 4.56 +/- 0.66 h-1 and 2.70 +/- 0.47 h-1. Corresponding absolute sodium efflux averaged 65.1 +/- 14.8 and 38.9 +/- 9.6 mmol/l/h, respectively.

Cell Separation↗
PubMed1987

Cell membrane handling of sodium in lymphocytes during salt restriction in normotensives.

Lymphocyte sodium content and sodium efflux were studied in 9 healthy normotensive males without history of essential hypertension before, during and after 5 weeks of severe sodium depletion. Sodium depletion caused a significant increase in sodium content and a slight but non-significant decrease in potassium content. Total and ouabain-sensitive sodium efflux rate constants decreased significantly during sodium depletion, while absolute sodium efflux, derived from cellular sodium concentration and the corresponding sodium efflux rate constants, remained unchanged. A significant reduction in arterial mean and diastolic blood pressure, measured by ambulatory as well as by home readings, was observed during salt restriction. Prolonged severe sodium depletion of normotensive subjects leads to changes in lymphocytic sodium homeostasis, probably due to a primary inhibition of the sodium pump and a secondary intralymphocytic sodium accumulation. The mechanism underlying these changes remains unclarified.

Adult↗
PubMed1987

Influence of physical activity on plasma digoxin in hospitalised patients.

The influence of physical activity on the plasma digoxin concentration was investigated in 13 digitalised patients suffering from a variety of cardiac diseases. Plasma digoxin concentration was determined four times during two consecutive days. In the morning, the standing position and one hour of physical activity caused a consistent and significant decrease in the plasma digoxin concentration, the mean reduction being 26.7 percent. In the afternoon, no consistent changes of plasma digoxin concentration were observed during one hour's rest. Consequently, we suggest standardisation of the blood sampling procedure so that no blood collection takes place in the morning until the patient has been performing normal physical activity for at least one hour.

Adult↗
PubMed1986

The significance of the enterohepatic circulation on the metabolism of digoxin in patients with the ability of intestinal conversion of the drug.

A cardiac patient had to be given a very high dosage of digoxin to attain therapeutic plasma level. The increased dosage requirement could partly be explained by reduced bioavailability due to intestinal conversion of digoxin. Consequently, the kinetics of the drug was examined before and after erythromycin treatment. Before treatment the determination of the area under the concentration versus time curve (AUC) following a single dose of digoxin given orally or intravenously demonstrated a substantial reduction in the absolute bioavailability. Erythromycin administration during 20 days caused a dramatic rise in AUC when the single oral dose was repeated, exceeding the two AUC obtained prior to initiation of the antibiotic therapy, and the steady state plasma digoxin level was 2-3-fold increased. The fact that the AUC obtained for a single oral dose of digoxin after erythromycin treatment exceeded that obtained when given intravenously before erythromycin indicated the presence of an enterohepatic circulation of digoxin. This may contribute substantially to the elimination of digoxin in patients with the capability of intestinal conversion of digoxin.

Digoxin↗