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Biomedical subjects

F Krück

Publications and source records attributed to F Krück.

At least 37 records · Page 2Linked to original sources

Clinical, endocrinological, and cytological characterization of two 46, XX males.

In two 46,XX males, 20 and 21 yr of age, gonadotropins, testosterone, and estradiol were measured in serum and compared to those in a control group of four men. In addition, in one subject, androgen metabolism was measured in biopsied skin and cultured skin fibroblasts. In both XX men, a pulsatile pattern of gonadotropin, testosterone, and estradiol release into serum was observed. The levels of the gonadotropins and estradiol were higher and the levels of testosterone were lower in XX men than in normal men. hCG stimulation resulted in a significant increase in testosterone secretion, and LRH administration caused a more prolonged rise in gonadotropin levels in the XX men. The administration of estradiol caused a positive feedback response in the XX men and resulted in a suppression of gonadotropin secretion in the controls. Finally, the formations of C-19 metabolites from testosterone and estrone from androstenedione were found to be in the same range in skin and skin fibroblasts from the XX men as in those from normal men. It can be concluded that 46,XX men have altered hypothalamic-pituitary and gonadal function compared to normal men.

Adult↗

[Use of routinely performed spirometry in the general medical examination (author's transl)].

The value of routine spirometry was investigated in 631 unselected out-patients. The spirogram was abnormal in 17%, the ECG in 15% and the chest X-ray in 13% of patients. Pathological spirograms correlated mainly with mild or moderate obstructive ventilatory disturbances (80%) which were associated with clinical findings in only 74%. In the ECG, disturbances of repolarisation were more common (71%) than those of stimulation and conduction (29%) and were associated with clinical findings in 65%. In 91% of patients with pathological chest radiograms other investigations had indicated the necessity for an X-ray. Thus spirometry is, in addition to ECG and chest X-ray, a useful routine method. As disorders of the lung function are not always predictable by smoking habits, spirometry offers the possibility for early detection of symptom-free disease of the lung and respiratory tract.

Electrocardiography↗

Evidence for participation of kinins in the antihypertensive effect of converting enzyme inhibition.

In low- and normal- renin hypertensive patients, but not in high-renin patients, the acute antihypertensive response to the angiotensin-converting enzyme (ACE) inhibitor captopril was completely blocked by aprotinin-induced kallikrein inhibition. Blood pressure reduction with long-term ACE inhibition could be overcome only in part by aprotinin. It is proposed that in low- and normal-renin hypertension the vasodepressor effect of acute ACE inhibition is mainly due to kinin accumulation. Conversely, in high-renin patients a fall in angiotensin II concentration accounts for the hypotensive response to captopril. From the pressor effect of aprotinin in chronically captopril treated patients it appears that kinins are also involved in the blood pressure reduction with long-term ACE inhibition. The finding that ACE inhibition and kallikrein blockade produced predictable and opposite effects on blood pressure suggests broad participation of changes in depressor kinin production in the control of vascular tone in essential hypertension.

Adult↗

[Pseudohyponatremia in multiple myeloma (author's transl)].

In the present study frequency and mechanisms of alterations in serum electrolytes in multiple myeloma were investigated. Asymptomatic hyponatremia (up to 93 mmol/l) was present in 7 of 15 patients. Water of serum was significantly lower, viscosity of serum significantly raised as compared to healthy controls. A highly significant negative correlation between sodium concentration and viscosity was found. By measuring serum sodium concentration with viscosity independent dilution systems it could be proved that in each case the observed hyponatremia was caused by flaws in our routinely used viscosity dependent dilution method. The decrease in water of serum contributed only little to the development of hyponatremia. It is concluded that the decrease in serum sodium concentration in multiple myeloma is nothing else than a feigned hyponatremia which needs no therapy.

Aged↗

[A new principle in long-term treatment of essential hypertension: angiotensin-converting enzyme inhibition (author's transl)].

The blood pressure lowering effect of the orally effective converting-enzyme-inhibitor captopril (SQ 14.225) was investigated in a double-blind study in 20 patients with moderate essential hypertension. During treatment with captopril alone (150 mg t.i.c.) blood pressure dropped from an average of 167/111 to 148/99 mm Hg lying and from 164/113 to 143/99 mm Hg upright whereby 4 patients showed normalisation of their blood pressure (less than 145/95 mm Hg). There was no significant change of pulse frequency. Addition of hydrochlorothiazide led to return to normal of blood pressure in all patients. Even after 6 months of treatment tolerance had not developed. The antihypertensive effect of captopril alone paralleled the one of hydrochlorothiazide and there were no side effects. Activity of the converting enzyme in serum as well as plasma concentrations of angiotensin II and aldosterone were clearly lowered by captopril whereas plasma renin activity increased significantly. Renal sodium and water excretion and glomerular filtration rate were not influenced.

Adult↗

[Clonidine in the management of hypertensive crisis (author's transl)].

Haemodynamic data were obtained by means of Swan-Ganz balloon catheters in eight patients during hypertensive crisis. After obtaining control values, 150 microgram clonidine in 10 ml isotonic sodium chloride was administered intravenously over ten minutes. During the hypertensive crisis there was a moderate rise in pulmonary artery and right ventricular pressures, in addition to a rise in systemic arterial pressure. In addition there was a lower than normal cardiac index, averaging 2.2 l/min.m2, a reduced stroke volume of 49.3 ml, a markedly elevated peripheral vascular resistance of 3584 dyn.s.cm-5, and an elevated cardiac work index of 5.08 kg.m/min.m2. After clonidine administration there was a significant fall in systolic, diastolic and mean femoral artery pressures (P less than 0.005), without any significant fall in pulmonary artery and right ventricular pressures. At the same time there was a further fall in cardiac index to an average of 1.85 l/min.m3, largely due to a reduced heart rate. Stroke volume fell slightly in only two patients. Peripheral vascular resistance did not fall significantly, while cardiac work index was significantly below the control value as late as four hours after clonidine administration.

Acute Disease↗

Decreased urinary kallikrein activity and elevated blood pressure normalized by orally applied kallikrein in essential hypertension.

Urinary kallikrein excretion was significantly lower in patients with essential hypertension (0.48 +/- 0.05 EU/24 h) than in normotensive controls (1.26 +/- 0.14 EU/24 h). Oral administration of hog pancreatic kallikrein normalized decreased urinary kallikrein and reduced arterial pressure. The treatment-induced rise in urinary kallikrein was due to an enhanced release of endogenous enzyme, as was determined by radioimmunoassay. It is proposed that in the hypertensive patients the low urinary kallikrein excretion reflects a defect in renal kallikrein formation which is normalized by oral kallikrein. The hypotensive action of oral kallikrein as well as its stimulating effects on renal kallikrein release suggest that the kallikrein-kinin system is involved in blood pressure regulation and that impaired renal kallikrein activity may be a factor in the maintenance of essential hypertension.

Adult↗

Impaired renal kallikrein activity and elevated blood pressure normalized by orally applied kallikrein in essential hypertension.

Urinary kallikrein excretion was significantly lower in patients with essential hypertension (0.48 +/- 0.05 EU/24 h) than in normotensive controls (1.26 +/- 0.14 EU/24 h). Oral administration of hog pancreatic kallikrein normalized decreased urinary kallikrein and reduced arterial pressure. The treatment-induced rise in urinary kallikrein was due to an enhanced release of endogenous enzyme, as was determined by radioimmunoassay. It is proposed that in the hypertensive patients the low urinary kallikrein excretion reflects a defect in renal kallikrein formation which is normalized by oral kallikrein. The hypotensive action of oral kallikrein, as well as its stimulating effects on renal kallikrein release, suggest that the kallikrein-kinin system is involved in blood pressure regulation and that impaired renal kallikrein activity may be a factor in the maintenance of essential hypertension.

Administration, Oral↗

Testosterone metabolism in human bone.

The conversion of [1,2,6,7-3H]testosterone to [3H]dihydrotestosterone has been assessed in ground sp¿ongiosa of normal and osteoporotic bone. The tissue was obtained from 23 patients, 18 women, 3 men and 2 children who were undergoing orthopedic surgery. The formation of dihydrotestosterone was demonstrated in all samples examined. The half maximum rate of dihydrotestosterone formation occurred at a substrate concentration of 0.3 microM a value similar to that reported for dihydrotestosterone formation in other androgen target organs. Under the standardized conditions utilized in this study the rate of dihydrotestosterone formation did not differ significantly in normal as compared to osteoporotic bone. Furthermore, the conversion of testosterone to androstenedione was also similar in osteoporotic and normal bone. Based on these studies it seems reasonable to conclude that dihydrotestosterone rather than testosterone is the active intracellular androgen in human bone since in other androgen target tissue androgen action is mediated by dihydrotestosterone if 5 alpha-reductase is present.

Adult↗

Low urinary kallikrein excretion and elevated blood pressure normalized by orally kallikrein in essential hypertension.

1. Urinary kallikrein was measured in 67 patients with essential hypertension and 25 normotensive subjects variously on unrestricted and low sodium diet. Also, the effect of orally applied hog pancreatic kallikrein on elevated blood pressure and kallikrein excretion was evaluated. 2. Urinary kallikrein was reduced in a large subgroup of patients with sustained essential hypertension. 3. With salt restriction, urinary kallikrein rose markedly in normotensive subjects and patients with borderline hypertension but not in those with sustained hypertension. 4. Oral kallikrein normalized reduced kallikrein excretion and lowered elevated blood pressure. 5. The rise in urinary kallikrein with oral kallikrein was due to an increased formation of endogenous enzyme. 6. A defective kallikrein-kinin system may be involved in both the low urinary kallikrein excretion and the hypertension.

Administration, Oral↗

[Effect of a chronic alpha adrenergic receptor blockade on basal secretion of renin in essential hypertension].

To investigate the effect of chronic alpha-adrenergic receptor blockade on renin release, plasma renin activity (PRA) was determined overnight at short intervals in 9 patients with essential hypertension before and after 7 days medication with phenoxybenzamine (20 mg orally/day). Inhibition of basal (supine) renin secretion in response to alpha-adrenergic receptor blockade was more apparent in patients with elevated PRA (n = 3) than in those with normal PRA. On the other hand, patients with low PRA (n = 2) even showed an increase in renin release. In addition, night-day variations with secretory episodes in PRA were blunted during drug administration. It is suggested that alpha-adrenergic receptor blockade inhibits renin secretion distal to its blockade of specific adrenergic receptors. However, the increase in renin release during phenoxybenzamine observed in patients with low PRA indicates that the responsiveness of renin secretion to stimulatory effects (most probably induced by the lowered blood pressure in our patients) remained intact during alpha-adrenergic receptor blockade.

Adrenergic alpha-Antagonists↗

Clinical and pharmacological investigations of the new saluretic azosemid.

Ple 1053 (Azosemid) is a diuretic which resembles furosemide chemically and in its mode of action. When administered intravenously, Ple 1053 was approximately 5 times more potent on a weight basis than furosemide, its dose-response relationship was closer and the slope was steeper. After oral administration Ple 1053 and furosemide were approximately equal in potency. However, the effect of Azosemid in healthy subjects was relatively prolonged and abrupt peaks did not occur.

Administration, Oral↗

Third factor and edema formation.

Urine extracts as well as plasma and urine fractions from normal persons during extracellular volume expansion and from patients with edema of different origin were tested for natriuretic (rat bioassay) and antinatriferetic (frog skin) activity. Whereas the extracts and fractions from normal persons with extracellular volume expansion proved to have a distinct natriuretic and antinatriferetic effect, no such effect was observed with urine and plasma preparations from patients with sodium retention and edema. Whether or not edema formation is mediated by a loss of natriuretic activity remains still to be clarified.

Adult↗