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Biomedical subjects

N Norman

Publications and source records attributed to N Norman.

At least 55 records · Page 3Linked to original sources
PubMed1980

Serum insulin response to oral glucose load during a dietary intervention trial in healthy coronary high risk men: the Oslo study.

The effect of an ordinary lipid-lowering diet on serum insulin response to oral glucose load was investigated in a randomized, primary preventive trial of the Oslo Study of coronary heart disease in healthy high risk middle aged men. After 3 years intervention the treated group showed a significantly lower insulin response curve, a lower serum total cholesterol, a higher cholesterol ratio (defined as the ratio between high density lipoprotein cholesterol and low density + very low density lipoprotein cholesterol), lower fasting triglycerides and lower relative body weight than the control group. Increased levels of serum insulin and elevated insulin response to oral glucose load has been shown in earlier studies to be associated with increased susceptibility for atherosclerotic diseases. Therefore, it might be of importance, that lipid-lowering diet induce a lowering of serum insulin response in healthy, coronary prone men. As a contrast to the two high risk groups, the very low response curve of serum insulin and glucose in a group of coronary low risk men is also presented, and it is suggested that serum insulin levels should be added to the coronary prone syndrome of hyperlipidemia, obesity and physical inactivity.

Adult↗
PubMed1979

Haemodynamic effects of treatment and withdrawal of spironolactone in essential hypertension.

The effect of spironolactone (50 mg b.i.d.) in essential hypertension was studied by measurement of effective renal plasma flow (ERPF), blood urea nitrogen (Ur+), serum creatinine (Cr), cardiac index (CI), plasma volume (PV), body weight (BW), mean arterial blood pressure (MAP), total peripheral resistance index (TPRI), plasma renin activity (PRA) and plasma aldosterone (PA) in two groups of patients. Ten cases had determinations before, after 5 weeks and 4 months of treatment; fourteen cases who had been treated at an average of 18 months, had measurements while on treatment and 5 weeks after cessation of the drug. Among the ten patients ERPF fell in six and increased in four patients during treatment, but was statistically unchanged in the total group. Ur + and Cr were also unchanged by treatment. ERPF was unchanged after withdrawal of the drug. During treatment BW decreased 3.5%, PV decreased in nine and increased in one patient, while PRA and PA increased 426% and 202%, respectively. After cessation of the aldosterone blockade, BW increased 1.9%, PV 10.5% while PRA and PA fell 60% and 48.9%, respectively. MAP fell in eight out of ten patients during treatment. This fall was associated with a fall in CI or TPRI, or both. After withdrawal of the drug, MAP increased in nine and decreased in five of the patients. The data shows that this dosage of spironolactone gave minor adjustments of the systemic and renal circulation in spite of the consistent changes in BW, PV, PRA and PA.

Adult↗
PubMed1979

Urinary sodium and blood pressure in vegetarians.

Urinary sodium, potassium urea, creatinine, uric acid, plasma urea, creatinine, cholesterol, blood pressures, height, weight, and skinfold thickness were measured in some or all of 106 matched pairs of vegetarians (mainly Seventh-Day Adventists) and nonvegetarians. Mean blood pressures were lower in vegetarians (141.9/88.9 mm) than nonvegeterians (148.0/90.9 mm) but the urinary excretion of sodium was higher, although not significantly, in the vegetarians (mean of 169.7 compared with 161.2 mmole/day). The vegetarians also had a higher urinary potassium excretion (62.9 mmole/day) than the nonvegetarians (54.8 mmole/day) thus giving them a lower mean sodium to potassium ratio (3.0 compared with 3.3). Both systolic and diastolic blood pressures correlated positively with plasma cholesterol levels which were less in vegetarians (6.0 mmole/liter) than nonvegetarians (6.6 mmole/liter). They also correlated positively with the urinary sodium to potassium ratio, but only in nonvegetarians. It was concluded that dietary sodium does not explain the blood pressure differences between vegetarians and nonvegetarians.

Adolescent↗
PubMed1979

Decreased renal plasma flow during propranolol treatment in essential hypertension.

The pharmacodynamic effect of propranolol (80 mg b.i.d.) on the renal and systemic circulation was studied after 1 and 8 months of treatment in 13 patients with essential hypertension, using non-invasive radioisotope techniques. Effective renal plasma flow (ERPF) fell from (mean +/- S.E.M.) 244 +/- 18 to 208 +/- 14 after 1 month and to 187 +/- 13 ml/min.m2 after 8 months of treatment. Concomitantly cardiac index (CI) fell from 3.24 +/- 0.15 to 2.62 +/- 0.11 and 2.75 +/- 0.10 l/min.m2, respectively. The coefficient of correlation between the decreases in ERPF and CI was 0.49. Mean arterial blood pressure decreased from 138 +/- 5 to 118 +/- 5 and 116 +/- 4 mmHg, respectively. Left ventricular work was reduced by 30.2 and 27%, while peripheral resistance was unchanged. Total plasma volume was increased from 19.3 +/- 0.5 to 20.3 +/- 0.6 ml/cm after 1 month, but was within the same range as the control values after 8 months of treatment. Pulmonary plasma volume was unchanged, indicating that there was no pooling of plasma in the pulmonary circulation. The interventricular circulation time was increased from 6.9 +/- 0.4 s to 8.4 +/- 0.3 s and varied with the change in heart rate. It is concluded that the fall in ERPF might be explained by reduced cardiac output in addition to interference with the hemodynamic autoregulation in the kidney.

Adult↗
PubMed1978

Renal plasma flow and cardiac output during hydralazine and propranolol treatment in essential hypertension.

Eleven patients with essential hypertension were given hydralazine (25 mg b.i.d.) for 2 weeks, hydralazine and propranolol (80 mg b.i.d.) for the next 2 weeks, and propranolol alone for the last 2 weeks. The changes in the renal and systemic circulation elicited by the drugs were studied before start of medication and bi-weekly during the treatment, using non-invasive radioisotope techniques. Hydralazine alone did not alter mean arterial blood pressure (MAP), heart rate (HR), cardiac index (CI), effective renal plasma flow (ERPF), peripheral renin activity (PRA) and plasma aldosterone (Aldo) but when propranolol was added MAP fell 15.2%, HR 22.5% and CI 18.4%, while ERPF was unchanged. When hydralazine was withdrawn and propranolol was given alone, ERPF decreased 13.2%. Plasma aldosterone was unchanged, whereas PRA decreased during propranolol treatment. The reduction in ERPF elicited by propranolol, was highly significant (P less than 0.01). From the test sequence it appears that dihydralazine prevents this effect of propranolol on kidney function. These findings might have a direct bearing on the choice of antihypertensive treatment.

Adult↗
PubMed1978

The cardiac response to a small i.v. dose of dihydralazine, a safe drug for diagnostic tests?

Dihydralazine, given in small i.v. doses, has been of great value in diagnostic tests for unilateral renovascular hypertension, where it enhances renin release on the affected side. The acute hemodynamic effects of an i.v. dose of 0.1 mg/kg b.wt. were studied in 14 patients with essential hypertension, using a quantitative renographic technique for determination of effective renal plasma flow and radiocardiographic technique for determination of the parameters in systemic circulation. Cardiac index increased from 4.040 to 6.423 1/min.m2 (p less than 0.01), stroke index from 59 to 66 ml/beat.m2 (p less than 0.05), heart rate from 70.4 to 96.6 beats/min (p less than 0.01) and left ventricular work index from 1.04 to 1.49 W/m2 (p less than 0.01), while mean arterial B decreased from 125 to 110 mmHg (p less than 0.01) and total peripheral resistance index from 2927 to 1534 10(5).N.s.m(-3) (p less than 0.01). Effective renal plasma flow and pulmonary plasma volume were unchanged. Peripheral renin activity increased from 0.5 to 1.6 nmol A1/1.h (p less than 0.02). It is concluded that even a small test dose of 0.1 mg/kg of dihydralazine elicits a considerable additional work load on the heart, a circumstance that must be taken into consideration in studies of patients with coronary heart diseases.

Adult↗
PubMed1975

Scintigraphy with 131I-19-iodocholesterol in adrenal disease.

Adrenal scintigraphy after i.v. injection of 131I-19-iodocholesterol has been performed in 4 patients with primary aldosteronism, 5 with Cushing's syndrome and 1 patient with phaeochromocytoma. In primary aldosteronism a unilaternal adrenocortical adenoma was demonstrated in 2 patients, while the method failed in 1 patient to visualize a tumour that was localized by measurements of aldosterone concentrations in the adrenal veins and by adrenal venography; in 1 patient none of the methods demonstrated a tumour. In Cushing's syndrome, adrenal scinitgraphy indicated bilateral adrenocortical hyperplasia in 1 patient and visualized the tumour in 2 patients with adrenocortical adenoma. In all patients with Cushing's syndrome due to unilateral adrenocortical tumour, the accumulation of radioactivity in the contralateral adrenal was suppressed. However, a delayed and slight accumulation of the isotope in the suppressed gland contralateral to an adrenocortical carcinoma was misinterpreted and led to exploration on the wrong side since the tumour did not concentrate radioactivity at all. The method failed in 1 patient to localize the adrenocortical tissue responsible for the relapse of Cushing's syndrome after bilateral adrenalectomy for hyperplasia. In the patient with phaeochromocytoma, no radioactivity was found on the tumour. It is conculded that adrenal scintigraphy is a safe and valuable method for localization of adrenal tumours and their differentiation from adrenocortical hyperplasia. Some diagnostic pitfalls do, however, exist, as demonstrated in this series of patients.

Adolescent↗
PubMed1975

Effective renal plasma flow (ERPF) of the individual kidney and renal venous renin activity (RVRA) determined simultaneoulsy before and after the administration of dihydralazine in renovascular hypertension.

Effective renal plasma flow (ERPF) and renal venous renin activity (RVRA) were determined for the two kidneys separately before and after intravenous administration of dihydralazine in 50 cases of suspected unilateral renovascular hypertension. A ratio above 1.4 between the ERPFs of the two kidneys and an RVRA ratio above 1.5 were used as signs of lateralization. The two procedures showed agreement about presence or absence of lateralization in 36 cases before and 44 after dihydralazine administration. Eleven patients underwent surgery. ERPF and the changes in ERPF induced by dihydralazine gave important prognostic and preoperative information. Data on renin release rates are presented.

Adolescent↗