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Biomedical subjects

S Simonsen

Publications and source records attributed to S Simonsen.

At least 37 records · Page 2Linked to original sources
PubMed1989

Serum HDL2 distribution in patients with coronary heart disease and controls as estimated by a precipitation reaction between HDL2 and an extract of Staphylococcus capitis.

Serum HDL2 concentration has been shown to be lowered in patients with coronary heart disease (CHD). Since we previously reported that serum HDL2 can be estimated by single radial diffusion in agar containing an extract of Staphylococcus capitis, it seemed of interest to study whether serum HDL2 as estimated by this method is different in CHD patients and controls. It was shown that relative activity of HDL2, assessed by the method, was appreciably lower in 40 men with angiographically proven coronary artery disease (CAD) than in a control group of 39 men of the same age. Also apolipoprotein A (apo A) concentration was lower in the CAD group, but group difference in HDL2 activity was greater than separation based upon apoA. It is suggested that precipitation with an extract of Staphylococcus capitis might be a useful approach to estimate serum HDL2 levels.

Adult↗
PubMed1988

Plasma atrial natriuretic peptide in cardiac transplant recipients. A prospective study.

Cardiac transplantation in 10 patients with congestive heart failure resulted in reduction of high plasma concentrations of atrial natriuretic peptide (ANP), preoperatively five-fold above normal, to a level two-fold above normal, which was maintained throughout a 12-week follow-up period. Cardiac function was normalized in all patients. Transient increases in plasma ANP, in four cardiac recipients 3-10-fold their basal levels, could neither be related to rejection episodes nor to cardiac dysfunction, but rather to signs of fluid and sodium retention. High plasma ANP levels in cardiac transplant recipients suggest that the capacity to secrete ANP is preserved in the transplanted heart.

Adolescent↗
PubMed1987

Increased beta-adrenoceptor-coupled adenylate cyclase response in transplanted human hearts.

A transplanted (Tx) heart will probably compensate its sympathetic denervation by increasing the sensitivity to adrenergic stimulants. To evaluate whether this also engages the myocardial adenylate cyclase (AC) system, small endomyocardial biopsies were collected at right heart catheterization both from patients with heart Tx with no signs of rejection and from a group of patients serving as controls. In crude homogenates from these biopsies, AC activity was measured at basal conditions and following in vitro stimulation with optimal concentrations of beta-receptor agonists, histamine and sodium fluoride (NaF). The Tx group exhibited a 75% (p = 0.01) higher activation of AC with isoproterenol, and a 62% (p less than 0.05) higher AC activation with terbutaline compared with the control group. The differences in AC activation by histamine and NaF were insignificant. Thus, sympathetic denervation leads to increased activation of the beta-adrenoceptor-coupled AC system, leaving the histaminergic system unaltered. The upregulation does probably engage the receptor part of the receptor-AC system exclusively, since no elevation of NaF stimulation of AC was found in the Tx hearts.

Adenylyl Cyclases↗
PubMed1985

Catecholamine-responsive adenylate cyclase activity in human endomyocardial biopsies. Individual sensitivity to isoproterenol stimulation and propranolol inhibition.

In the present study we have examined adenylate cyclase (AC) activity, the stimulation by isoproterenol and inhibition by propranolol, in endomyocardial biopsies from eleven patients with suspected cardiomyopathy. Biopsies were obtained by heart catheterization from the right endomyocardial surface of the interventricular septum. Three biopsies were taken from each patient (mean weight, 2.1 mg; range, 1.2-4.0 mg). One biopsy was studied by light microscopy. The two other biopsies were homogenized and AC activity in the homogenates was determined in the presence of different concentrations of isoproterenol and isoproterenol (5 micrograms/ml) combined with different concentrations of propranolol. Thus stimulation and inhibition curves were established for a pair of biopsies from each patient. Appropriate biopsy material was obtained in triplicate from only seven patients. In these patients the variance in maximal receptor stimulation (by isoproterenol) and inhibition (by propranolol) was significantly smaller in pairs of biopsies compared to the variance between all biopsies (p values from less than 0.05 to less than 0.025). Hence it is possible to determine AC activity, and adrenergic receptor function, in very small endomyocardial biopsies. New diagnostic possibilities could thereby be introduced.

Adenylyl Cyclases↗
PubMed1979

Combined aortic and mitral valve replacement. A randomized study comparing the Björk-Shiley and Lillehei-Kaster disc valve.

The present series was comprised of 48 patients, 25 of whom received the Björk-Shiley (B-S) and 23 the Lillehei-Kaster (L-K) disc valves. The 2 groups were comparable with regard to age, and to preoperative clinical and hemodynamic status. The randomized selection was carried out at the beginning of the operation. The total mortality in the B-S and L-K groups was 16% and 21% respectively. All surviving patients were restudied 13-40 months (mean 27) after surgery. Late thromboembolic complications occurred in 2 patients with B-S and in 3 with L-K valves, all leaving minor neurological sequelae. There was a relatively large number of patients in the L-K group with unmeasurable values of haptoglobin, indicating more hemolysis in these patients. However, the difference was not statistically significant. The clinical and hemodynamic status was improved in both groups. In the aortic position a significant gradient was found across the L-K valve, while no significant obstruction in the flow was found in the B-S valve. The pulmonary arteriolar resistance was significantly higher in patients with B-S than in those with L-K valves. Otherwise, there was no significant differences between the 2 groups, neither with regard to clinical nor to hemodynamic status.

Aortic Valve↗
PubMed1979

Determination of pressure gradient in mitral stenosis with Doppler echocardiography.

The accuracy of a non-invasive ultrasound Doppler technique for the determination of the pressure gradient in mitral stenosis was evaluated in a study of 8 adult patients. Transseptal left atrial catheterisation and retrograde left ventricular catheterisation were performed. The same diastoles were used to compare the gradient constructed from the ultrasound data (delta PU) with that constructed from the manometric data (delta PM). In the 8 patients the difference betweent he mean diastolic values of delta PU and delta PM was - 0.54 +/- 1.0 (SD) mmHg. The corresponding figure for mid-diastole was 0.01 +/- 0.9 (SD) mmHg. The results indicate that the ultrasound technique is sufficiently accurate for diagnostic purposes.

Adult↗
PubMed1979

An ultrasound Doppler technique for the noninvasive determination of the pressure gradient in the Björk-Shiley mitral valve.

The accuracy in determining the pressure gradient in the Björk-Shiley mitral implant from noninvasive ultrasound Doppler data was explored in nine adult patients. Manometric and ultrasound data were collectd simultaneously, and identical diastolic periods were used to compare the manometric gradient (delta Pm) with the gradient obtained from ultrasound data (delta Pu). In the nine patients the mean diastolic value of delta Pm ranged from 2-12.5 mm Hg and the difference between the mean diastolic values of delta Pm and delta Pu was 0.3 +/- 1.0 mm Hg(SD). The results of the investigation indicated that the method is accurate and reliable in the nonivasive determination of the mean diastolic gradient in the Björk-Shiley mitral implant.

Blood Pressure↗
PubMed1978

Effect of carbocromen induced coronary vasodilatation on myocardial metabolism in coronary artery disease.

Myocardial metabolism was studied during coronary vasodilatation by carbocromen during atrial pacing in patients with coronary arteriosclerotic disease. Coronary sinus flow was measured by the continuous infusion thermodilution technique. Carbocromen increased myocardial flow by the same amount at rest and during pacing-induced tachycardia. The administration of carbocromen did not interfere with myocardial oxygen consumption, free fatty acid (FFA) uptake, pulmonary or systemic hemodynamics. Atrial pacing above the anginal threshold increased lactate and hypoxanthine excretion to the coronary sinus, but to a greater extent during carbocromen treatment. Thus, carbocromen is a specific coronary vasodilator acting independently of pacing induced vasodilatation. Metabolic data indicate a small but unfavourable effect on ischemic metabolism which might be due to a "coronary steal".

Cardiac Pacing, Artificial↗
PubMed1978

Determination of renal blood flow by thermodilution method.

The single bolus thermodilution method for measurement of renal vein blood flow was tested. In model experiments the thermodilution method was compared with graduated cylinder measurements over a flow range from 50 to 1050 ml/min. There was a good correlation between the two methods (r = 0.98) with a mean of differences of 5.2%. In eighteen patients measurements were performed in duplicate in thirty-one renal veins. Comparison was made between the first (x) and second (u) measurement--performed within 3 min. The correlation between the two was very good (r = 0.99; y = 1.03x - 11.48). In twelve patients bilateral renal vein blood flow measurements were performed simultaneous to blood flow measurement by PAH clearance. The correlation between total flow measured by thermodilution (y) and by the clearance method (x) was good (r = 0.98; y = 0.79x + 221). It is concluded that the thermodilution method requires catheterization of the renal veins, but is otherwise simple to perform, is inexpensive and gives reliable results. It is particularly advantageous when repeated measurements in the study of acute changes in renal haemodynamics is desirable.

Humans↗
PubMed1978

Effect of nifedipine (Adalat) on coronary haemodynamics in patients with coronary arteriosclerotic disease.

Effects of the new Ca++ antagonist nifedipine (Adalat) on coronary haemodynamics were studied in 8 patients with documented ischaemic heart disease. The continuous infusion thermodilution technique was used to measure cardiac venous blood flow. Sublingual application of 10 mg nifedipine caused a significant increase (16%) in myocardial blood flow and a decrease (18%) in coronary arteriolar resistance at rest, but not during a submaximal atrial pacing test. There was no change in coronary arteriovenous oxygen difference, myocardial oxygen consumption, oxygen consumption per unit of heart rate blood pressure index or left ventricular efficiency index. The effects on the coronary haemodynamics are discussed in relation to the simultaneous changes in general haemodynamics. Systolic aortic pressure was slightly reduced, significantly only at rest, while peripheral vascular resistance decreased and cardiac output increased also during atrial pacing. No change in free fatty acid metabolism was observed. It is concluded that nifedipine is a mild coronary vasodilator. No effect was observed on myocardial oxygen demand. The oxygen cost of left ventricular work was unchanged by the drug both at rest and during the submaximal stress test.

Adult↗
PubMed1978

Dialysis fistulas and cardiac failure.

A haemodialysis fistula may be a factor in the development of cardiac failure, and surgical reduction of fistula blood flow can improve the condition. We have investigated 6 patients with dialysis fistulas and closed the fistula in one of them, with marked improvement of cardiac failure. It is unlikely that a peripheral dialysis fistula can cause cardiac failure by itself, but it may be a contributing factor when the cardiac reserve is reduced due to other causes.

Adult↗
PubMed1978

Verapamil and pulmonary hypertension.

We report on the effect of verapamil in 12 patients suffering from pulmonary hypertension. The drug caused a slight, but statistically significant decrease in mean pulmonary artery pressure and in the work performance by the right ventricle. The mean pressure of the right atrium, the end-diastolic pressure of the right ventricle, the pulmonary arteriolar resistance, the cardiac index and the stroke volume were not significantly changed, however, and there was a wide spread of the values observed. In some patients the drug exerted a marked negative inotropic effect, with a concomitant increase in the pulmonary arteriolar resistance.

Adult↗
PubMed1978

Myocardial biopsy in diagnosis of endomyocardiopathy in patient with electro- and vectorcardiographic signs of myocardial infarction.

A 52-year-old woman is described with the clinical picture of congestive heart failure, electro- and vectorcardiographic evidence of myocardial infarction, combined with angiographically hypokinetic left ventricle, but with patent coronary arteries. Endomyocardial biopsy disclosed changes consistent with 'congestive cardiomyopathy'. Thus, the study shows that the Q wave pattern on the electrocardiogram provides insufficient evidence for the diagnosis of myocardial infarction, and may be misleading in patients with cardiomyopathy. In such circumstances, endomyocardial biopsy from the left or right ventricle appears to be a helpful diagnostic method, and further use of this technique may permit a more precise diagnosis in patients with a history of myocardial infarction, but with normal coronary arteries.

Biopsy↗