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Biomedical subjects

R Kolloch

Publications and source records attributed to R Kolloch.

At least 37 records · Page 2Linked to original sources
PubMed1993

Neurohormonal and metabolic effects of severe and moderate salt restriction in non-obese normotensive adults.

OBJECTIVE: The effects of severe and moderate sodium restriction on blood pressure, neurohormonal activity and serum lipids were studied in non-obese normotensive adults. METHODS: In the first part of the study, 163 subjects were randomly assigned to a diet of 20 or 300 mmol/day sodium for 1 week each. In the second part, 25 subjects were given a diet of 85 or 200 mmol/day sodium for 4 weeks each in random order. RESULTS: After severe salt restriction 19% of the subjects had a significant decline (salt-sensitive group), 15% showed a significant rise (counter-regulator group) and 66% exhibited no change in blood pressure (salt-resistant group). Severe sodium restriction increased plasma renin activity and noradrenaline concentration, as well as serum total and low-density lipoprotein-cholesterol and triglycerides. After correction for haematocrit, only the changes in total and low-density lipoprotein-cholesterol remained significant. The rise in plasma renin activity during salt restriction was steeper in the counter-regulator group than in the other groups, whereas the changes in plasma noradrenaline concentrations were similar in all groups. During moderate salt restriction, plasma renin activity and noradrenaline concentration were significantly increased, but serum lipid concentrations and blood pressure did not change. CONCLUSION: In non-obese normotensive adults, severe and moderate salt restriction stimulates neurohormonal activity. In contrast to severe salt restriction, a moderate reduction in dietary salt intake does not influence blood lipids in normotensive subjects.

Adult↗
PubMed1993

Divergent hemodynamic and hormonal responses to varying salt intake in normotensive subjects.

Blood pressure responses to 1 week of low-salt (20 mmol sodium/d) and high-salt (300 mmol sodium/d) intake were investigated in a single-blind randomized study in 163 white, nonobese normotensive subjects (65 women and 98 men; mean age, 38 +/- 1.2 years). The individuals were classified as salt sensitive when mean arterial blood pressure rose by at least 5 mm Hg during high-salt intake, as salt resistant when mean arterial blood pressure changed by less than 5 mm Hg, and as "counterregulator" when mean arterial blood pressure fell by at least 5 mm Hg during the high-salt diet. Reexamination of 31 subjects showed that this approach to the testing of salt sensitivity was reliable and reproducible. Thirty subjects (18.4%) were classified as salt sensitive, 108 (66.3%) as salt resistant, and 25 (15.3%) as counterregulators. Multiple regression analysis revealed that age, body weight, and family history of hypertension contributed significantly to the change in blood pressure after the diets. Salt sensitivity was more frequent in older subjects and in those with a positive family history of hypertension. An increase in blood pressure after salt restriction was more likely in younger individuals and in those with a negative family history of hypertension. Plasma renin activity and plasma aldosterone concentrations were lower in salt-sensitive compared with salt-resistant and counterregulating subjects. The rise in plasma renin activity during salt restriction was most pronounced in counterregulating subjects. Plasma norepinephrine concentrations were not different among the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of a high-cholesterol diet on arterial wall thickness and vascular reactivity in young rabbits.

Cholesterol enrichment of arteries may induce biochemical and structural abnormalities in vascular smooth muscle resulting in increased arterial contractile sensitivity. We studied the effects of a high-cholesterol diet on arterial structural properties and vascular reactivity in young rabbits. In vivo measurements of aortic intimal-plus-medial thickness using high resolution ultrasound imaging were obtained before and after 3 weeks of a high-cholesterol diet in 12 rabbits (group 2) and compared to data from 12 animals a cholesterol-free diet fed (group 1). Six rabbits (group 3) were studied before and after a 3-week, high-cholesterol diet and after a subsequent 13-week, cholesterol-free recovery diet. Blood pressure responsiveness to noradrenaline was evaluated before and at the end of each diet period. In groups 2 and 3, high dietary cholesterol caused an increase in intimal-plus-medial thickness from 0.31 mm and 0.33 mm to 0.88 mm and 0.89 mm, respectively (p less than 0.001). Plasma cholesterol concentration rose from 0.9 +/- 0.26 mmol/l to 36.7 +/- 8.56 mmol/l. There was no change in group 1. In group 3, intimal-plus-medial thickness remained increased (1.01 mm) following the cholesterol-free recovery diet despite normal plasma cholesterol. Blood pressure responsiveness to noradrenaline was markedly increased after the high-cholesterol diet (p less than 0.001) in groups 2 and 3 and after the cholesterol-free recovery diet in group 3 (p less than 0.001), and was directly related to intimal-plus-medial thickness (r = 0.84; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Primary amyloid tumor of the lung].

Primary idiopathic amyloidosis may be a diagnostic problem because of its low incidence and its variable manifestations. The clinical and radiographic findings in a patient with accidentally discovered primary amyloidosis of the lung are presented. The extensive mediastinal and hilar lymph-node enlargement was striking. Peripheral bronchial carcinoma was initially suspected because of the radiographic and CT findings. Various patterns of pulmonary amyloidosis have to be considered in the differential diagnosis of nodules and interstitial changes of the lung.

Amyloidosis↗
PubMed1991

Short-term dietary sodium restriction increases serum lipids and insulin in salt-sensitive and salt-resistant normotensive adults.

Evidence suggests that dietary salt reduction similar to diuretic therapy may adversely affect lipid and glucose metabolism. We studied 147 non-obese normotensive subjects (60 females and 87 males) aged 19-78 years who entered a single-blind crossover trial and were randomly assigned to a low salt diet of 20 mmol or a high salt diet of 300 mmol sodium per day, for 7 days each. Sodium restriction lowered mean arterial blood pressure (MAP) by a mean of 7.5 mmHg in 17% (salt-sensitive), had no hemodynamic effect in 67% (salt-resistant) and raised MAP by a mean of 6 mmHg in 16% of the subjects (reverse reactors). With dietary salt restriction serum total- and LDL-cholesterol as well as serum insulin and uric acid concentrations increased significantly in all three groups. The largest increases in total (10%) and LDL- (12%) cholesterol occurred in the reverse reactors. Salt-sensitives had significant higher lipoprotein(a) values than the other two groups. Salt-restriction had no significant effect on this parameter. Plasma renin activity, as well as plasma aldosterone and noradrenaline concentrations rose in all three groups during the low salt diet, the largest increases being observed in the reverse reactors. Short-term sodium restriction in normotensive adults has unfavourable effects on lipid and glucose metabolism, especially in subjects who do not derive hemodynamic benefit. Further studies are necessary to examine the effects of more moderate salt reduction for longer periods on the risk factor profile for cardiovascular disease before a low salt diet can be regarded as a safe public health measure for the general population.

Adult↗
PubMed1990

[Therapy of moderate hypertension with the calcium antagonist nitrendipine in combination with beta receptor blocker or diuretic].

The efficacy of the calcium channel blocker nitrendipine alone and in combination with the beta blocking agent acebutolol or hydrochlorothiazide was tested in 34 patients with moderate essential hypertension. After a wash out period of three to four weeks, all patients received placebo for two weeks, thereafter 20 mg of nitrendipine per day for four weeks. When diastolic blood pressure remained above 95 mmHg with nitrendipine, acebutolol (200 mg/d) or the thiazide (25 mg/d) was added in a randomised double-blind fashion. With nitrendipine alone, blood pressure could be normalized in nine patients with a drop in pressure from 168/108 to 152/89 mmHg. The other patients showed a fall in blood pressure from 164/110 to 152/102 mmHg. In these patients, the addition of acebutolol or thiazide was followed by a further fall in blood pressure which was similar with both drugs. With acebutolol blood pressure decreased from 154/102 to 146/94 mmHg and with the thiazide from 152/102 to 147/95 mmHg, respectively. Minor and mostly transient side effects were predominantly seen during therapy with nitrendipine alone. The fall in diastolic but not systolic blood pressure with nitrendipine was correlated with age. The blood pressure lowering effect of nitrendipine was independent of plasma renin activity and intracellular electrolyte concentrations. In the therapy of moderate hypertension, nitrendipine given in combination with a betablocker or a thiazide diuretic is effective and well tolerated.

Acebutolol↗
PubMed1990

[Cough, dyspnea, hemoptysis].

The 26-year-old man experienced symptoms of chronic airway obstruction with shortness of breath, cough and wheezing, which primarily led to a diagnosis of asthma bronchiale. Absence of adequate response to antiasthmatic treatment and development of hemoptysis and weight loss led to the tentative diagnosis of upper airway obstruction by tumor. Bronchoscopy revealed adenoid cystic carcinoma of the distal trachea.

Adult↗
PubMed1989

Altered plasma leucine-enkephalin concentrations in patients with established hypertension may be involved in impaired regulation of blood pressure.

Leucine-enkephalin is known to modulate cardiovascular activity. In the present study we determined plasma leucine-enkephalin and noradrenaline concentrations in young men with essential hypertension and in normotensives at rest and after bicycle exercise. The essential hypertensive patients had a lower concentration level of resting leucine-enkephalin than the normotensives. Exercise increased leucine-enkephalin in both groups. Noradrenaline was significantly higher in the essential hypertensives than in the normotensives. The central alpha 2-agonist clonidine reduced leucine-enkephalin at rest in the normotensives and prevented its increase during exercise, but had no effect on leucine-enkephalin in the essential hypertensives. These results may reflect an altered interaction between leucine-enkephalin and noradrenaline in essential hypertensives compared to normotensives, possibly contributing to hypertension.

Adult↗
PubMed1988

Reduced beta-endorphin secretion in young patients with mild essential hypertension at rest and during exercise.

Evidence suggests that altered central adrenergic and opioidergic activities are involved in the elevated blood pressure of patients with essential hypertension. In the present study plasma concentrations of the opioid peptide beta-endorphin were significantly lower at rest in young subjects with essential hypertension and high plasma noradrenaline (n = 9) than in normotensive controls (n = 13, P less than 0.05). After bicycle exercise the beta-endorphin of both groups increased comparably, the percentage increase being greater in essential hypertensives than in controls. Treatment with clonidine for 14 days normalized low beta-endorphin, high plasma noradrenaline and high blood pressure in essential hypertensives at rest, but had no effect in controls. After bicycle exercise clonidine induced a threefold greater increase in beta-endorphin in controls than in essential hypertensives. The results point to a reduced endorphinergic activity in essential hypertensives, both at rest and during exercise, which can be normalized by central alpha 2-agonism at rest only. The results may indicate altered interactions between central adrenergic and opioidergic receptor systems, which could contribute to high blood pressure in essential hypertensives.

Adult↗
PubMed1987

[Bronchography during flexible bronchoscopy. Indications and results in bronchiectasis].

The radiological imaging of the respiratory tract by bronchography has apparently lost in importance since the introduction of newer imaging methods. Indications for and results of bronchography, performed after bronchoscopy with a flexible bronchoscope under local anesthesia, were analysed in 115 patients. In 68 the bronchography had been performed because of suspected bronchiectasis, in the others because of hemoptysis, cough or infiltration of unclear etiology. In 43% of patients who had undergone bronchography bronchiectasis was indeed found, in 47% there were isolated or additional changes in the bronchial system. In 70% the examination had furthered the diagnosis. The described method of bronchography was not significantly more uncomfortable than flexible bronchoscopy alone. Combined bronchoscopy and bronchography is thus a valuable procedure in the diagnosis of pneumonological abnormalities.

Adolescent↗
PubMed1987

[Diagnosis of sarcoidosis using MR tomography].

One hundred and thirty-three patients with lymph node enlargement from various causes were examined by MR tomography, using 0.5 and 1.5 Tesla. Amongst these, there were 27 patients with chronically enlarged lymph nodes and histologically confirmed sarcoidosis; these showed characteristic T1 intervals. Enlarged lymph nodes due to chronic inflammatory conditions can be differentiated from lymph nodes with malignant lymphoma, or from lymph node metastases from carcinomas. Although there are problems with the determination of relaxation times on MR tomography, this may be a valuable method for the differential diagnosis of sarcoid.

Adult↗
PubMed1987

Normalization of blood pressure and plasma concentrations of beta-endorphin and leucine-enkephalin in patients with primary hypertension after treatment with clonidine.

Opioid peptides are thought to be involved in blood pressure regulation, possibly via an interaction with the sympathetic nervous system (CNS). To further elucidate this hypothesis the plasma concentrations of beta-endorphin, leucine-enkephalin and noradrenaline were determined overnight (9 p.m. to 8 a.m.) in young patients with mild essential hypertension and then compared to normotensive controls. The mean concentrations of beta-endorphin during the early night (9 p.m. to 2 a.m.) and leucine-enkephalin were lower (p less than 0.05, p less than 0.01, respectively) than in the normotensive subjects, but the noradrenaline concentration was higher. After 14 days of treatment with clonidine, which decreases sympathetic activity via a central action, beta-endorphin, leucine-enkephalin, and noradrenaline concentrations did not differ between both groups. It is concluded that the lower plasma concentrations of beta-endorphin and leucine-enkephalin in the hypertensive group could reflect reduced opioidergic activity in the CNS and in the peripheral sympathetic neurons and also could be involved in the increased sympathetic activity of these patients. Besides via sympathetic inhibition, clonidine also may reduce the increased blood pressure further by normalizing central beta-endorphin release.

Adult↗
PubMed1986

Effects of the new angiotensin-converting enzyme inhibitor, ramipril, in patients with essential hypertension.

The antihypertensive and hormonal effects of the new angiotensin-converting enzyme (ACE) inhibitor, ramipril, were assessed by means of a single-blind trial in ten unselected patients with mild-to-moderate essential hypertension. After a 2-week period on placebo, 5 mg ramipril was administered once daily for 2 weeks. Blood pressure returned to normal in five patients and decreased in the remaining patients, without significant changes in heart rate or orthostatic hypotension. A fall in blood pressure was apparent within 1-2 h of the first dose; the maximum decrease was reached at 4-6 h and a fall in pressure was still detectable after 24 h. At 24 h post dose angiotensin-converting enzyme activity was suppressed to 40% of the baseline. Blood pressures for the 10 h interval post dosing showed smooth through-the-day control with minimal peak/trough difference in lowering effect. The magnitude of the blood pressure decrement achieved with the inhibitor did not correlate with baseline renin levels or the rise in renin following treatment. No side-effects were noted during the 2-week observation period. The study demonstrates that ramipril, given in a once-daily regimen over a period of 2 weeks, is well tolerated and provides smooth and effective blood pressure control throughout the 24-h interval between doses.

Adult↗
PubMed1986

Mineralocorticoid escape during kallikrein inhibition.

Kinins have been considered to be involved in the escape from the sodium retaining effects of mineralocorticoids. In a metabolic study in rats, the importance of the kallikrein-kinin system for sodium and potassium excretion was evaluated by aprotinin-induced kallikrein inhibition under basal conditions and during DOCA administration. Kallikrein inhibition was accompanied by a transient sodium retention. The escape from the sodium retaining effect of DOCA was not affected. However, the DOCA-induced potassium loss was enhanced. Kallikrein inhibition decreased urinary prostaglandin (PG) E2 and prevented the DOCA-induced rise in PGE2. Plasma renin activity was stimulated after 10 days of aprotinin administration. The kallikrein-kinin system is not an important mediator of the escape phenomenon but it may play a role in the regulation of sodium and potassium excretion.

Animals↗