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Biomedical subjects

C Marone

Publications and source records attributed to C Marone.

49 records · Page 3Linked to original sources
PubMed1981

Acute hypercalcemic hypertension in man: role of hemodynamics, catecholamines, and renin.

The effect of acute hypercalcemia on blood pressure, blood volume, hemodynamic parameters, plasma norepinephrine, epinephrine, dopamine, renin, and aldosterone concentrations was investigated. After 1 hour of equilibration, 10 patients received an infusion of calcium gluconate in 5% dextrose (calcium 15 mg/kg of body wt in 3 hours). The calcium infusion increased the mean serum calcium from 8.7 to 13.0 mg/dl, the systolic blood pressure from 144 +/- 10 to 184 +/- (SEM) 12 mm Hg (P less than 0.001), the diastolic pressure from 78 +/- 4 to 93 +/- 5 mm Hg (P less than 0.01). The plasma volume was decreased by 9% (P less than 0.001), whereas the hematocrit was increased (P less than 0.05). Heart rate and cardiac output remained unchanged. Total peripheral resistance was increased from 1643 +/- 223 to 2256 +/- 387 dyne.sec/cm5 (P less than 0.05). The plasma epinephrine concentration rose from 4.5 +/- 0.7 to 6.9 +/- 1.2 ng/dl (P less than 0.01). The plasma norepinephrine concentration was unchanged after 2 hours and increased only slightly after 3 hours of calcium infusion. Plasma renin, aldosterone, and dopamine concentrations were not significantly changed. These findings demonstrate that acute hypercalcemic hypertension is mediated by an increase in peripheral vascular resistance. Hypercalcemic hypertension may be induced by a direct effect of calcium on blood vessels; calcium-mediated increase in adrenal epinephrine release may play a mild contributory role, and plasma volume contraction, an inhibitory role.

Adult↗
PubMed1980

Effects of a new diuretic (piretanide) compared with furosemide on renal diluting and concentrating mechanisms in patients with the nephrotic syndrome.

The mode and site of action of the new diuretic agent piretanide were investigated in man. The effect of a single oral dose of 12 mg was compared with that of furosemide 80 mg p.o. iin 6 patients with the nephrotic syndrome. Piretanide showed a greater diuretic and natriuretic response than furosemide during maximal water diuresis, but the effect was similar in the hydropenic state. Like furosemide, piretanide decreased free water clearance relative to delivery during water diuresis and the reabsorption of solute-free water during hydropenia. This inhibitory action on both the concentrating and diluting urinary mechanisms demonstrates an effect of piretanide localized in the ascending limb of Henle's loop. Consistent alterations in glomerulur filtration rate, renal blood flow or filtration fraction were not observed.

Body Water↗
PubMed1980

Role of haemodynamics, catecholamines and renin in acute hypercalcaemic hypertension in man.

1. The effect of acute hypercalcaemia on blood pressure, blood volume, haemodynamic indices, plasma catecholamines, renin and aldosterone levels was investigated in 10 patients. 2. Calcium infusion (15 mg/kg over 3 h) increased (P < 0.05) plasma calcium and adrenaline levels, blood pressure, total peripheral resistance and packed cell volume. Plasma volume was decreased, and heart rate, cardiac output and plasma renin, aldosterone or dopamine levels were not significantly changed. Plasma noradrenaline was increased only minimally after 3 h of calcium infusion. 3. Mean blood pressure before and during calcium infusion correlated with concomitant serum calcium (r = 0.39; P < 0.02) or adrenaline levels (r = 0.57; P < 0.01); changes in blood pressure correlated with variations in plasma adrenaline (r = 0.68; P < 0.001). 4. Acute hypercalcaemic hypertension is mediated by an increase in peripheral vascular resistance and may be induced by a direct effect of calcium on blood vessels. The calcium-mediated increase in adrenaline release may play a contributory, and plasma volume contraction an inhibitory, role.

Adult↗
PubMed1978

[The variation of 16 serum protein fractions following renal transplantation (author's transl)].

We have investigated 16 serum proteins in 20 patients with stable renal function after renal transplantation. Our investigations have shown the following substantial findings: a regular increase of prealbumin, alpha1-glycoprotein, haptoglobin, hemopexin and beta2-glycoprotein, as well as a rather frequent increase of alpha 2-macroglobulin. As far as variations of the serum protein levels are concerned there was no correlation with kidney disease, accompanying illnesses, therapy or interval since transplantation.

Adult↗
PubMed1977

[Interstial pneumopathy after low dose bleomycin therapy].

The case is report of a 52-year-old woman who died of interstitial pneumopathy following treatment for an unclassifiable neoplasm of liver, spleen and bone marrow with a total dose of 97 mg/m2 bleomycin. The development of interstitial pneumopathy after this low bleomycin dosage may have been favored by a previous thorax irradiation 22 years earler for round cell sarcoma.

Bleomycin↗
PubMed1977

[Serum lipids in diminished kidney function, during hemodialysis and after kidney transplantation].

Lipids have been investigated in three groups of patients with chronic renal insufficiency. 19 patients were on conservative treatment (no dialysis), 52 patients were on regular hemodialysis, and 27 patients had been transplanted. The results were compared with those obtained from control subjects of the same age and sex. Hyperlipoproteinemia was found in 25% of the uremic patients, 55% of hemodialysis patients, and 85% of transplant recipients. The predominant lipid abnormalities were hyperlipoproteinemia of Type IV in both uremic (5 out of 19) and hemodialysis patients (17 ou of 52). Hyperlipoproteinemia of Type II was mainly observed after transplantation (IIb: 13, IIa: 5 out of 27).

Adult↗
PubMed1977

[Serum protein values in uremic patients, dialysis-patients and patients with transplanted kidneys].

Within three patient groups (1. advanced renal failure, 2. patients under chronic hemodialysis, 3. patients with renal transplants) 16 serum proteins were determined immunochemically employing MANCINIS method. The group mean values for each protein were compared, and the statistical significance of intergroup differences was examined. The most noteworthy results were the following: a distinct increase in prealbumin in all groups, least marked in the dialyzed patients; frequent elevation of alpha2-macroglobulin in the patients with transplanted kidney, but not in the other two groups; a significant increase in beta2-glycoprotein in all groups. Other changes affected several components of the acute phase reactants which were, in part, markedly elevated. On the other hand, alpha1-antitrypsin and transferrin remained largely within the normal range. Possible mechanisms accounting for some of these changes are discussed.

Adult↗
PubMedDate not supplied

Cardiovascular and metabolic profile during intervention with urapidil in humans.

Increased sympathetic activity or vascular reactivity to norepinephrine or both may play a complementary role in the pathogenesis of essential hypertension. Therefore, blood pressure regulation and metabolic correlates of cardiovascular risk were evaluated in 19 normal subjects and in 13 subjects with essential hypertension receiving placebo and after 4 weeks of intervention with urapidil, an agent that was found experimentally to exert a combined central sympathetic and peripheral alpha-adrenergic receptor inhibition. In hypertensive patients, urapidil normalized the initially low norepinephrine pressor dose (+ 106%), mildly increased basal plasma norepinephrine levels (+36%), and markedly shifted the plasma norepinephrine concentration-blood pressure response curve (p less than 0.01). Blood pressure was decreased (p less than 0.001). In normal subjects, urapidil produced only mild increases in norepinephrine plasma levels (+22%) and norepinephrine pressor dose (+38%) and no change in blood pressure. Body weight, exchangeable sodium, and blood volume were unaltered or increased slightly. Heart rate; plasma epinephrine, renin, angiotensin II, basal aldosterone, and electrolyte levels; plasma clearances of norepinephrine and angiotensin II; pressor effects of angiotensin II; chronotropic responses to isoproterenol or a norepinephrine-induced rise in blood pressure; and urinary prostaglandin F2 alpha excretion, as well as serum lipoprotein fractions and glucose, insulin, and uric acid levels, were not significantly modified by urapidil. Prostaglandin E2 excretion tended to be increased. Aldosterone responsiveness to angiotensin II was increased by urapidil in normal (p less than 0.05) but not in hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Predicting intradialytic hypotension from experience, statistical models and artificial neural networks.

BACKGROUND: Symptomatic intradialytic hypotension (IDH) associated with increased mortality in hemodialysis patients is difficult to predict and hence prevent. Artificial Neural Networks (ANNs) are promising tools to solve multidimensional non-linear problems. The aim of the study was to verify in which way mathematical models, statistics or knowledge of patients influence the ability of the nephrologists to predict IDH. METHODS: The performance of ANNs was compared with that of independent nephrologists supported by a logistic regression giving odds ratio for each studied variable (NEPHiS) or of nephrologists in charge of the patients without (NEPHc) or with statistical support as for NEPHiS (NEPHcS). Data from 98 hemodialysis patients were analysed in order to select patients with frequent IDH (>10% of the dialysis sessions). Complete data on 1979 dialysis sessions from 7 patients were retrieved. The ability to predict the occurrence of hypotension episodes was compared (ROC curves) between ANNs, NEPHc/S (N=7) in Switzerland and NEPHiS from independent dialysis centers in Western Australia (N=10). RESULTS: ANN gave the most accurate correlation between estimated and observed IHD episodes compared to NEPHc (p<0.001), but a similar performance was attained by NEPHcS (p<0.001). NEPHiS were superior to NEPHc (P<0.05), but inferior to ANN (P<0.01). For a sensitivity of 80%, specificity was 44% for ANNs, 33% for NEPHcS and 20% for NEPHc. CONCLUSIONS: ANNs are superior to nephrologists in predicting IDH episodes; however when supported by a statistical analysis, nephrologists reach ANNs in their prediction ability. IDH still remains difficult to predict even with mathematical models.

Aged↗