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Biomedical subjects

B Wocial

Publications and source records attributed to B Wocial.

At least 109 records · Page 6Linked to original sources

[Pheochromocytoma].

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Adrenal Gland Neoplasms↗

Alterations in plasma dopamine-beta-hydroxylase and catecholamine concentrations during surgical removal of pheochromocytoma.

In order to determine the mechanism of release of catecholamines from pheochromocytoma plasma levels of noradrenaline (NA), adrenaline (A), dopamine (DA) and dopamine-beta-hydroxylase (DBH) were measured in 6 patients with pheochromocytoma undergoing surgical treatment. In 4 patients both the DBH activity and plasma catecholamine concentrations rapidly increased during surgical manipulation of the tumor. In the remaining 2 patients dispite increase of plasma catecholamines DBH activity remained unchanged during surgical manipulation of the pheochromocytoma. The present results suggest that a certain fraction of plasma catecholamines in patients with pheochromocytoma is released from the tumor by exocytosis.

Adrenal Gland Neoplasms↗

Sympathetic reactivity to upright posture in borderline and established hypertension.

Plasma and urinary catecholamines and their metabolites were estimated in 18 patients with borderline hypertension (BH), 27 patients with established hypertension (EH) and 15 healthy subjects in basal conditions and after 20-min standing. Patients with EH differed from the remaining groups, showing decreased urinary excretion of noradrenaline (NA). In patients with BH, in comparison with controls, an augmented plasma NA in basal conditions as well as a more pronounced increment of plasma NA in response to upright posture was observed. Moreover, in BH increased urinary excretion of dopamine, homovanillic acid and 3-methoxy-4-hydroxyphenylglycol has been found. In patients with BH the increase of diastolic blood pressure in response to upright posture was associated with an exaggerated increase of plasma NA and adrenaline. The results of the study show that patients with BH are characterized by sympathetic overactivity and suggest that in this type of hypertension this factor may play a role in response of blood pressure to physiological stimuli.

Adolescent↗

Prostaglandin levels and renin activity in renal venous blood of patients with renal hypertension.

In view of the possible role of prostaglandins /PG/ in the pathogenesis of hypertension we have determined PGE2 and PGF2 alpha levels simultaneously with plasma renin activity/PRA/ in renal venous and caval venous blood in 13 patients with unilateral renal artery stenosis/RAS/ and in six untreated patients with unilateral parenchymal renal disease/PRD/. Four patients with essential hypertension were the control group. PG levels and PRA were estimated by RIA. In patients with RAS the mean PGE2 level as well as PRA was higher on the side of the stenosis. No such difference was found in the PGF2 alpha level. There was a significant correlation between the renal vein PGE2 ratio and renin ratio /stenotic side versus contralateral side/ r=0.520, 0.02 less than p less than 0.05. In patients with PRD prostaglandin levels in venous blood of the affected kidney were similar to that of venous caval blood, but markedly elevated in the venous blood of the contralateral kidney. PRA was similar on both sides. The data obtained in this study indicate, that prostaglandins in renal venous blood behave differently in hypertensive patients with RAS and PRD. In patients with RAS augmented PGE2 release may serve as a protective mechanism. In patients with PRD, the increased PG level in the non-affected kidney may reflect a compensatory mechanism in spite of the atrophic process in the affected kidney.

Adolescent↗

Changes in the excretion of catecholamines and their metabolites in patients with essential hypertension during sodium intake restriction.

Excretion of noradrenaline (NA), adrenaline (A), dopamine (DA) and their metabolites vanillylmandelic acid (VMA), methoxycatecholamines (MNA + MA) as well as 3-methoxy-4-hydroxy-phenylglycol (MHPG) was studied in 95 patients with essential hypertension and in 25 normal subjects on normal and low sodium diets. The patients were divided into 3 groups according to NA excretion under basal conditions. NA excretion was increased during sodium intake restriction, the highest values of this increase being found in patients whose basal NA excretion was diminished. At low sodium intake the high and the low NA excretors responded with significant increases of DA excretion. The mean excretion of VMA increased significantly on low sodium diet in all 3 groups of patients. The MNA + MA excretion decreased significantly during sodium intake restriction in patients with normal NA excretion. At low sodium intake the excretion of MHPG was highest in patients with low basal NA excretion. These data suggest that in patients with essential hypertension subjected to sodium restriction the excretion and metabolism of catecholamines are related to basal sympathetic activity.

Adolescent↗

The urinary excretion of 3-methoxy-4-hydroxyphenylglycól in acute myocardial infarction.

Urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG), noradrenaline, adrenaline and vanillylmandelic acid (VMA) was studied in 30 patients with acute myocardial infarction. The excretion of MHPG was higher in patients with myocardial infarction than in the control group, with no difference between uncomplicated and complicated courses of the disease. The excretion of MHPG showed a negative although not significant correlation with noradrenaline and VMA during the first days of infarction and a statistically significant positive correlation on the 5th day of the disease. The possible causes of the changes observed are discussed.

Adult↗

The effect of mental stress on catecholamines, their metabolites and plasma renin activity in patients with essential hypertension and in healthy subjects.

1. Ten patients with essential hypertension and ten healthy men were submitted to mental stress consisting of Kraepelin's arithmetic test combined with noise. Concentrations of plasma and urine catecholamines and of their metabolites as well as plasma renin activity before and after the test were studied. 2. In both groups a significant increase of noradrenaline and adrenaline in blood and noradrenaline in urine was observed. The urinary excretion of dopamine fell significantly in both groups after stress. 3. After mental stress a significant increase in urinary excretion of 3-methoxy-4-hydroxyphenylglycol was observed in both groups. The excretion of vanillylmandelic acid decreased significantly only in healthy subjects. 4. The plasma renin activity rose significantly in both groups but the increase was more pronounced in healthy subjects.

Adolescent↗