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Biomedical subjects

W Vetter

Publications and source records attributed to W Vetter.

At least 19 recordsLinked to original sources
PubMed1992

Urinary free cortisol versus 17-hydroxycorticosteroids: a comparative study of their diagnostic value in Cushing's syndrome.

We evaluated the usefulness of the basal urinary 24-h excretion rates of free cortisol versus 17-hydroxycorticosteroids in the diagnosis of Cushing's syndrome. On an outpatient basis, both urinary free cortisol and 17-hydroxycorticosteroids levels were determined in 48 patients with Cushing's syndrome, as well as in 95 obese and 94 healthy control persons of normal weight. Determination of the urinary free cortisol content allowed a clear-cut distinction between the patients with hypercortisolism and the controls, resulting in a sensitivity of 100% and specificity of 98% for the diagnosis of Cushing's syndrome. The diagnostic accuracy of urinary free cortisol was distinctly superior to that of 17-hydroxycorticosteroids, which showed a wide overlap of values between the groups, with a sensitivity of 73% and a specificity of 94%. In conclusion, the measurement of basal urinary free cortisol provided an excellent diagnostic sensitivity and specificity in the assessment of adrenocortical function. This simple and accurate test thus seems to be particularly useful in the outpatient evaluation of patients with suspected Cushing's syndrome.

17-Hydroxycorticosteroids↗
PubMed1979

[Hypertension in unilateral (non-vascular) nephrosclerosis: renin activity in the venous kidney blood and effect of nephrectomy].

13 patients (9 females, 4 males) with hypertension and unilateral (non-vascular) small kidney underwent nephrectomy. Before surgery, renin activity (PRA) was measured in renal vein blood before and/or 15 and 30 minutes after intravenous stimulation with 40 mg furosemide. From these PRA values renin rations (PRA affected side/PRA unaffected side) were calculated. A ratio of greater than or equal to 1.5 was considered to be significant. After a mean postoperative observation period of 3.9 +/- 1.3 years 6 patients (46%) were cured and 6 were improved. In only 1 patient (8%) did hypertension remain unchanged. No differences could be observed between the renin ratios of cured and improved cases. Furthermore, in no patient was a correlation found between preoperative renin ratios and the degree of postoperative blood pressure reduction. Finally, both patients with renin ratios less than or equal to 1.4 were cured by surgery. Marked differences between cured and improved patients were seen in preoperative blood pressure values, age, duration of hypertension and renal function. Cured patients were younger and had much lower mean systolic and diastolic blood pressure values, shorter duration of hypertension and better renal function than improved patients. These results show that the diagnostic and prognostic validity of renal venous renin ratios is very limited in patients with a unilateral (non-vascular) small kidney. In these patients the effect of nephrectomy can already be predicted by analyzing simple anamnestic, clinical and chemical data.

Adolescent↗
PubMed1979

[Minoxidil in treatment resistant hypertension].

22 patients (4 female, 18 male, mean age 47 +/- 10.7 years) with severe essential hypertension (n = 21) and renovascular hypertension (n = 1) were treated with a mean daily dosage of 16.3 +/- 5.1 mg minoxidil for up to 42 weeks. In addition, all patients received a diuretic (hydrochlorothiazide or furosemide) and a beta-blocker (pindolol or propranolol). 8 patients were treated simultaneously with alpha-methyl-dopa. Within one week minoxidil led to a significant reduction in both systolic and diastolic supine blood pressure (p less than or equal to 0.005) from 201.3 +/- 29.0/125.4 +/- 19.2 mm Hg to 172.8 +/- 28.3/106.0 +/- 19.9 mm Hg. The maximum initial blood pressure response was observed after 3 weeks with a mean daily dosage of 12.2 +/- 9.4 mg of minoxidil (160.5 +/- 20.7/99.4 +/- 13.8 MM Hg, p less than or equal to 0.001). Throughout the remaining period a constant and significant reduction in supine systolic and diastolic and upright diastolic blood pressure was achieved (p less than 0.005-less than 0.001) whereas at times systolic blood pressure values could not be lowered significantly. Body weight and pulse rate showed no significant changes throughout the study. In some cases furosemide had to be added by up to 500 mg/day to counteract minoxidil induced water and salt retention. Only moderate doses of beta-blockers were required to prevent a drug induced rise in pulse rate. In these patients a significant change in renal function was not observed. The results show that minoxidil is a potent drug in the treatment of severe essential hypertension.

Adult↗
PubMed1979

[Renovascular hypertension. Prognostic value of renal venous renin determinations (author's transl)].

In the present study the effect of surgery on blood pressure was investigated in 35 patients with renovascular hypertension: 17 patients with fibromuscular hyperplasia (FMD) and 18 with atherosclerosis (ASS) of the renal artery. Patients with FMD were younger (31,8 years), showed a shorter duration of hypertension (1.8 years) and were prevalently female (82%), whereas patients with ASS were markedly older (48.2 years), showed a longer duration of hypertension (2.6 years) and were most often male (78%). In both groups of patients the intravenous urogram was positive in a comparable high percentage (FMD=64%, ASS=61%). Following surgical intervention 47%(n=8) of the 17 patients with FMD were cured, 47% (n=8) were improved and only 6% (n=1) showed insufficient reduction of blood pressure values. In ASS the respective values were 28, 55 and 17%. Consequently a good effect of surgery (cured and improved) was observed in 88.5% of all patients. Patients with ASS who failed to respond to surgery (n=3) showed a remarkable long duration of hypertension (7.0 plus or minus 1.4 years). Plasma renin activity (PRA) was determined preoperatively in both renal veins in all 35 patients. From these values the PRA-ratio (PRA affected/unaffected side) was calculated. In 27 patients PRA determinations were repeated following (15 and 30 min) intravenous injection of 40 mg furosemide. PRA-ratios of larger than or equal to 1.5 were considered to be significant. In 31 patients with unilateral renovascular hypertension PRA-ratios were correlated to the postoperative blood pressure reduction. No significant differences in mean PRA-ratios were observed between cured and improved patients. Furthermore, for the total group of 31 patients no significant correlations were obtained between PRA-ratios and postoperative blood pressure reduction. Our results do not support the widespread opinion that PRA determinations in both renal veins are useful to predict the effect of surgery in patients with unilateral renovascular disease. Therefore, from our experience this method should not be recommended as obligatory in the diagnostic work-up of renovascular hypertension.

Adult↗
PubMed1979

[Are automatic devices suitable for blood pressure determinations?].

Four automatic blood pressure recorders (Bosograph II, Bosch EBM 500, Elag BE 237R, and Physiometrics SR-2) were compared with the random zero sphygmomanometer. Since each of the automatic devices was calibrated for phase IV, diastolic blood pressure values were read off at phase IV and not phase V of Korotkow with the random zero sphygmomanometer. Blood pressure measurements were carried out in 80 patients with hypertension and in 20 normotensive healthy subjects. Readings with the automatic recorders and with the random zero sphygmomanometer correlated well in a wide range of systolic and diastolic blood pressure (r = 0.878--0.982, p less than 0.001). However, the automatic values were in most cases significantly lower than those obtained with the random zero device. For Physiometrics SR-2, where two diastolic readings were possible, only the first diastolic values correlated well with phase IV of Korotkow. The second values were significantly lower, with a difference of -11.1 mm Hg, and probably did not reflect the true diastolic blood pressure. These results show that each of the four automatic recorders is suitable for measuring blood pressure. However, with the Physiometrics SR-2, Only the higher diastolic reading should be used. The differences between the four automatic devices were minor and can therefore be ignored.

Automation↗
PubMed1979

Age- and sex-related differences in plasma aldosterone in essential hypertension. Relationship to plasma renin activity.

In essential hypertension mean basal (supine) and stimulated plasma renin activity (2 h upright posture + 40 mg furosemide intraveneously) decreased progressively with age. No significant differences were observed in renin levels between male and female patients. With increasing age mean basal (supine) plasma aldosterone remained almost unchanged in females, whereas in males a slight increase was found. However, in the comparable age-groups no significant sex-related differences were obtained. In female patients changes in mean stimulated plasma aldosterone with increasing age paralleled those of plasma renin activity, whereas in males this relationship was less obvious: only a slight age-related decline in stimulated aldosterone levels was observed and significantly lower plasma aldosterone concentrations in male than in female hypertensives of the younger age-groups (less than 40 years) were found. The results indicate that in essential hypertension with increasing age dissociation between plasma aldosterone and plasma renin activity occurred. Furthermore, the described alterations in adrenal aldosterone release are more pronounced in male than in female patients.

Adolescent↗
PubMed1979

Night-day variations of renin-activity in primary aldosteronism.

To detect changes in previously unmeasurable low renin activity plasma specimens of 20 patients with primary aldosteronism (12 with an unilateral adenoma and 8 with idiopathic bilateral adrenal hyperplasia), obtained at short term intervals between 20.00 and 8.00, were incubated over a prolonged period of 18 hours. 6 of 12 patients with an aldosterone producing adenoma (APA) and 3 of 8 patients with idiopathic bilateral adrenal hyperplasia (IAH) showed typical night-day variations of PRA with lower values before and higher values after midnight. 7 of these 9 patients with night-day rhythmicity of PRA simultaneously showed secretory episodes. In 2 patients (1 with APA, 1 with IAH) PRA was constantly undetectable (less than 0.2 ng/ml . 18 h) and in 2 patients with APA a fixed secretion of renin was observed. We failed to demonstrate typical night-day variations of PRA in 3 patients with APA and in 4 with IAH, although in 5 of these 7 patients secretory episodes of PRA were found. Our results show that different patterns of PRA curves may be observed both in patients with APA and IAH. Thus, analysis of PRA curves is of no value to differentiate patients with APA from those with IAH.

Adenoma↗
PubMed1979

Metabolic studies of ornidazole in the rat, in the dog and in man.

1. Ornidazole, labelled with 14C in the imidazole ring, administered orally to rats, dogs and men was largely excreted in the urine, predominantly as metabolites, with less than 4% of the drug being excreted unchanged. Free and conjugated metabolites were found in the ratio of approx. 1 : 2. 2. The pattern of free ornidazole and metabolites was different in the three species: while ornidazole predominated in man, ornidazole and metabolite M1 in the dog, the most extensive metabolic pattern was found in the rat. 3. The following metabolites were identified: M1, 1-chlorlo-3-(2-hydroxymethyl-5-nitro-1-imidazolyl)-2-propanol; M2, 2-methyl-5-nitroimidazole; M3, N-(3-chloro-2-hydroxypropyl)acetamide: M4, 3-(-2-methyl-5-nitro-1-imidazolyl)-1, 2-propanediol; M5, acetamide. 4. The formation of metabolite M3 and M5 indicated cleavage of the imidazole ring between N-1/C-5 and C-2/C-3. Other ring scissions were not observed. Metabolites carrying a free amino group were not detected. On the basis of the structures identified, a scheme is suggested for the metabolism of ornidazole.

Animals↗
PubMed1978

[Experiences with a new hypouricemic diuretic (tienilic acid): comparison with hydrochlorothiazide].

A new hypouricemic diuretic (tienilic acid) was compared with hydrochlorothiazide in a double-blind study in 8 patients with mild essential hypertension. After a two-week placebo period the patients received either 250 mg tienilic acid or 50 mg hydrochlorothiazide in a single daily dose for 3 weeks. After a second placebo period of 2 weeks the patients received, in a crossover design, either tienilic acid or hydrochlorothiazide for a further 3 weeks. The reduction of blood pressure and of body weight was similar for both drugs. When treatment was started diuresis and natriuresis increased with tienilic acid and with hydrochlorothiazide. Whereas serum sodium levels showed only minor variations, serum potassium levels fell with both diuretics and urinary potassium excretion increased. Urinary calcium excretion decreased and serum calcium levels slightly increased under both treatments. Both diuretics induced similar increases of plasma renin activity, plasma aldosterone concentration and aldosterone-18-glucuronide excretion. Blood urea nitrogen and, to a lesser extent, serum creatinine levels were raised slightly under both drug regimens. Whereas the serum uric acid level rose and remained elevated for the duration of hydrochlorothiazide treatment, it fell significantly and remained lowered during treatment with tienilic acid. Uric acid clearance was about twice as high with tienilic acid as with hydrochlorothiazide. Tienilic acid therefore appears to be a therapeutic alternative to thiazides and other hyperuricemic diuretics in hypertensive patients in whom hyperuricemia should be avoided or corrected.

Adult↗
PubMed1978

[Renovascular hypertension: therapy by means of percutaneous transluminal dilatation of renal artery stenoses].

Percutaneous transluminal dilatation was performed in 5 patients with unilateral atherosclerotic renovascular disease and one patient with occlusion of a renal artery. Hemodynamic activity of the stenosis was documented by determination of pre- and poststenotic blood pressure values and by measurement of renal plasma flow. Flowing transluminal dilatation all patients showed a significant drop in blood pressure and antihypertensive treatment could be reduced or even discontinued. Only one patient became hypertensive again 3 months after the dilatation procedure. In this patient both the reduction of renal plasma flow and the delayed nephrographic effect on the stenotic side in the intravenous urogram were interpreted as symptoms of a recurrence of significant renal artery stenosis. In 2 of the six patients with impaired kidney function glomerula filtration are increased, as documented by a decrease in serum creatinine values. The results show that percutaneous transluminal dilatation may be a valuable method in the management of renovascular hypertension.

Creatinine↗
PubMed1978

[Left ventricular function in hypertension treated with beta blockers].

In 14 patients with essential hypertension, left ventricular function was assessed echocardiographically before and after 4 and 8 weeks of treatment with the betablocking agent atenolol. Atenolol was given orally in a dose of 100 mg/day. After 4 weeks of treatment systolic blood pressure decreased from 160 to 138 mm Hg(p less than 0.001) and diastolic pressure from 105 to 91 mm Hg(p less than 0.001). Heart rate decreased from 76 to 64 beats/min (p less than 0.05). Systolic shortening of the left ventricular transverse diameter declined from 41 to 36% (p less than 0.01), though in no instance did it fall below the lower limit of normality (30%). After 8 weeks of betablocking therapy, blood pressure and heart rate remained essentially unchanged. Systolic shortening increased slightly but insignificantly to 38%. The left ventricular enddiastolic diameter did not change throughout the study. It is concluded that longterm betablocking therapy is associated with a significant reduction of left ventricular function which improves in the later stage of treatment. Since the diminution of left ventricular function is slight, the induction of left heart decompensation is unlikely, at any rate in patients with initially normal left ventricular function.

Adrenergic beta-Antagonists↗
PubMed1978

Percutaneous transluminal dilatation: a new treatment of renovascular hypertension?

Percutaneous transluminal dilatation of a left sided renal artery stenosis was performed in a 61 year old patient with hypertension. Biochemical and hemodynamic activity of the renal artery stenosis was demonstrated by measurement of renal venous renin-activity and determination of renal plasma flow and of pre- and poststenotic blood pressure values. Shortly after the dilatation procedure hypertension disappeared and renal plasma flow increased. The described procedure might be an alternative method to renal vascular surgery.

Arterial Occlusive Diseases↗
PubMed1978

Control of plasma aldosterone in diabetic patients with hyporeninemic hypoaldosteronism.

In three patients with diabetes and hyporeninemic hypoaldosteronism changes in renin activity, plasma aldosterone and cortisol were examined under various conditions: orthostasis and intravenous furosemide, infusion of synthetic beta1-24 ACTH on two consecutive days and diurnal variations in basal hormone fluctuations. Each patient showed unmeasurably low renin activity unresponsive to orthostasis and intravenous furosemide while plasma aldosterone was below normal range. Under ACTH-infusion only marked increases in aldosterone were observed in one patient whereas cortisol responded normally in all diabetics tested. Analysis of diurnal night day fluctuations (20.00-8.00) in plasma aldosterone and cortisol revealed a close and statistically significant relationship between both hormones in each of the three patients (p less then 0.05-less than 0.001). Variations in plasma aldosterone thus were mediated through changes in endogenous pituitary ACTH. Compared with normal controls however, diurnal aldosterone curves were set at a lower level. Our results demonstrate that a reduced sensitivity of the adrenal gland to ACTH is not responsible for the observed subnormal plasma aldosterone levels in these patients. Therefore, the lack of circulating angiotensin II seems to be the causative reason of hypoaldosteronism. The exact mechanism of undetectable renin activity in these patients remains unknown.

Adrenocorticotropic Hormone↗
PubMed1978

Primary aldosteronism: inability to differentiate unilateral from bilateral adrenal lesions by various routine clinical and laboratory data and by peripheral plasma aldosterone.

In 31 patients with primary aldosteronism routine clinical and laboratory data, the effect of orthostasis on plasma aldosterone (PA), plasma renin activity (PRA) and cortisol (PC), effect of fludrocortisone or high sodium intake on basal PA and night-day fluctuations of basal PA and PC with and without suppression of pituitary ACTH by dexamethasone were determined to differentiate patients with a unilateral aldosterone producing tumour (adenoma, APA, n=20; carcinoma, CA, n=1) from those with idiopathic bilateral adrenal hyperplasia (IAH, n=10). Mean systolic and diastolic blood pressure, age, serum potassium and urinary excretion of sodium and potassium were not significantly different in both groups of patients. Normokalaemic primary aldosteronism occurred both in patients with APA (n=2) and in patients with IAH (n=1). Mean basal PA and mean urinary excretion rate of aldosterone-18-glucuronide were higher though not significantly different in patients with APA or CA than in those with IAH. A substantial number of the patients with APA (n=5) and with IAH (n=3) showed urinary excretion rates of aldosterone-18-glucuronide less than 13 microgram/24 h. Mean PA and PRA significantly increased (P less than 0.025) in patients with IAH in response to posture. However, these changes also occurred at times in some patients with APA. Both fludrocortisone and high sodium intake produced a variable and no group-specific effect on basal PA. Night-day variations in PA were positively correlated with those in PC in all patients with APA (n=12) and in 5 of 8 patients with IAH. A dissociation of PA and PC, however, was only observed in patients with IAH. Finally, the effect of dexamethasone on plasma aldosterone curves was variable in both groups of patients. Our results indicate that under the described conditions analysis of routine clinical and laboratory data and of peripheral PA, PRA and PC are of limited value in differentiating patients with APA or CA from those with IAH.

Adenoma↗