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Biomedical subjects

A Novarini

Publications and source records attributed to A Novarini.

At least 91 records · Page 5Linked to original sources
PubMed1981

Increased erythrocyte lithium--sodium countertransport in essential hypertension: its relationship to family history of hypertension.

1. Erythrocyte lithium--sodium countertransport was measured in 46 normotensive healthy controls without family history of hypertension, 15 subjects with essential hypertension, but without evidence of family history of high blood pressure, and 43 subjects with essential hypertension and at least one hypertensive first-degree relative. 2. Mean values (mmol h-1 l-1 of erythrocytes) were 0.248 +/- 0.092 in controls, 0.258 +/- 0.087 in hypertensive subjects without family history (not significant vs controls), 0.360 +/- 0.115 in hypertensive subjects with family history of hypertension (P less than 0.001 vs controls), 0.334 +/- 0.117 in all hypertensive subjects, both with and without family history (P less than 0.001 vs controls). 3. Our data confirm the finding of an increased erythrocyte lithium--sodium countertransport, but with a significant overlap between essential hypertension and control values. Lithium--sodium countertransport is higher only in hypertensive subjects with at least one hypertensive first-degree relative. 4. We suggest that the increase of lithium--sodium countertransport in erythrocytes is not a consistent marker of essential hypertension. It seems to be associated with the family prevalence and/or the hereditability of hypertension, rather than with high blood pressure per se.

Adult↗
PubMed1980

The influence of renal function on the elimination kinetics of sulbenicillin in man.

Serum concentration and urinary excretion following a single i.v. dose of 1 g Sulbenicillin (SB) have been studied in 13 subjects with different degrees of renal insufficiency and 4 control subjects. With normal GFR, serum half-life averages 27 min, with GFR between 45 and 14 ml/min, 1,5 hours, with GFR below 8-10 ml/min, 4,6 hours (maximum 7 hours). The usually recommended dosage schedule is 1 g every 6 hours. Only when GFR falls below 8-10 ml/min, the interval between doses must be changed; 1 g every 8-12 hours should be given under these conditions. However, in cases of severe extrarenal or urinary tract infections due to antibiotic-resistant strains of E. coli, Ps. aeruginosa, Pr. morganii, a first dose of 2-4 g SB should be given, followed by maintenance half-doses (1-2 g SB) every half-life.

Adult↗
PubMed1980

[Na/K transport in red blood cells from normal subjects: methodological problems (author's transl)].

In this work we present a method which evaluates the facility of applying and reproducing ion fluxes in human cells using radioactive 22Na as a tracer. Intracellular sodium concentration, rate constants for total (oKNa TOT), ouabain-sensitive (oKNa OUABs) and ouabain-insensitive (oKNa OUABins), sodium efflux and relative effluxes obtained by multiplying the rate constant by the sodium concentration were measured in the red cells of 20 normal subjects. Our results have been shown to be comparable with those obtained in other reports and show a statistically significant relationship between intracellular sodium concentration and the rate constant for active sodium efflux: one would conclude that the intracellular sodium constant probably depends on the activity of the sodium pump genetically determined in each individual. Since such a method is precise can be exactly reproduced, it can be applied to the study of cellular metabolism of different clinical disorders characterized by significant fluid and electrolyte imbalances.

Adult↗
PubMed1980

[Na/K transport in red blood cells from severely burned patients (author's transl)].

The working of the Na/K pump in the red cells of 6 patients with extensive burns was analyzed using radioactive substances with the aim of comparing their red cells with those of 20 normal subjects. In the red cells of patients with extensive burns was found that the intracellular sodium concentration was clearly increased, that the rate constant of ouabain-sensitive efflux diminished, and that the total sodium efflux was augmented by the increase of the ouabain-insensitive part. It is likely that the intra and extra-cellular transportation defects produce an accumulation of sodium inside the cell which succeeds in stimulating the activity of the pump. Although this pump is impaired, the high sodium concentration obtains a new steady state characterized by apparently normal ouabain-sensitive sodium efflux and by an increased ouabain insensitive efflux. The pathogenesis of these defects of cellular homeostasis which are linked to the presence of various complex mechanisms (shock, calorie balance, fluid and electrolyte imbalances, the circulation of "toxic substances" etc), in cases of extensive burns, has not been completely elucidated.

Adult↗
PubMed1978

Studies on cell water and electrolytes in chronic renal failure.

Studies were carried out in 10 normal subjects and in 16 patients with moderately severe chronic renal failure (CRF) to determine the quantities of potassium (K), sodium (Na) and water in muscle tissue obtained by needle biopsy and in white cells (WBC) from peripheral venous blood. Depletion of intracellular K with high levels of Na and normal water were found in patients with CRF. Therefore, the cellular electrolyte pattern was not substantially different from that reported by others in patients with advanced uremia although there was no increase in intracellular water (as can occur in end-stage CRF). These data suggest that in end-stage CRF accumulation of intracellular water could be relatively independent of intracellular electrolyte balance.

Adolescent↗
PubMed1978

Studies on bicarbonate reabsorption in chronic renal failure.

The role of nephron loss, extracellular fluid volume (ECFV) expansion and body potassium stores on bicarbonate reabsorption in chronic renal failure (CRF) was evaluated. In 17 CRF and 3 control subjects, tubular HCO3 reabsorption was studied by HCO3 1M titration technique; ECFV (22Na space at 4th hour) and cell K content (muscle biopsy) were also determined. Nephron loss per se does not cause any change of HCO3 reabsorption rate per unit GFR. With ECFV expansion induced by HCO3 infusion, a Tm HCO3 is rapidly reached only in controls and in CRF patients showing a significant basal ECFV expansion. In these subjects reabsorbed HCO3/Na ratio is constant, suggesting that under these conditions, HCO3 reabsorption depends on the same mechanisms that control Na reabsorption. In cell K depleted CRF patients, HCO3 reabsorption rises more than in controls and no Tm HCO3 is detected, at least within the limits of isotonic ECFV expansion induced by titration; in these subjects HCO3 reabsorption does not appear to be limited by natriuretic factors. In CRF subjects with normal ECFV and cell K, there is a greater HCO3 tolerance to ECFV expansion induced by titration technique than in controls.

Absorption↗
PubMed1978

[Thienylic acid, a new drug with saluretic and uricosuric activity. Preliminary data].

The effects of ticrynafen (250-500 mg) on salt-water and uric acid metabolism have been studied in 18 patients with no haemodinamic abnormalities or salt-water repletion (cardiac failure, oedema). The main results are: -- an effective natriuresis is observed in the first days and is attenuated thereafter. In subjects with a reduced GFR, a negative salt balance is obtained altough the volume of diuresis is not significantly increased. -- The potassium loss is variable according to dosage (maximum at 500 mg), renal function (low when reduced). -- The increase of urinary uric acid excretion and the lowering of blood uric acid concentration are rapid and prolonged. In conclusion, we confirm the effective natriuretic and uricosuric properties of ticrynafen.

Adult↗
PubMed1977

[Aspects of glycolipid metabolism in chronic renal insufficiency: interference of oral glucose administration during and after dialysis with changes induced by short dialyses with glucose free dialysate].

As part of some research into certain aspects of glycolipidic metabolism in chronic renal insufficiency, a study has been made of alterations in glycaemia, insulinaemia, free fatty acids and triglycerides during and following brief periods of dialysis by glucose-free bath in 26 subjects: within this group, 50 g of glucose were administered to 8 patients at the 2nd hour of dialysis and 100 g to another 8 at the end of therapy. The following findings were made during glucose-free dialysis: marked hypoglycaemia starting from the first hour until the end, marked increase in FFA and marked fall in TG upon the lipolytic action of heparin. In the post-dialysis period, immediate normalization in glycaemia, steady diminution in FFA and notable increase in TG as early as the 1st hour. Administration of glucose during dialysis prevents hypoglycaemia by altering FFA and TG behaviour in the post-dialysis period. Administration of glucose at the end leads to hyperglycaemia and hyperinsulinaemia with marked fall in FFA and TG. During dialysis, the phenomena observed depend on the action of heparin, acetate and the absence of glucose. This absence brings on hypoglycaemia with secondary glycogenolysis and-or neoglucogenesis during dialysis; in the post-dialysis period, hepatic neosynthesis of TG in the presence of normal glycaemic and insulinaemic values. Glucose per os determines hyperglycaemia and secondary hyperinsulinaemia with FFA esterification at the level of adipose tissue and a fall in serous TG.

Administration, Oral↗
PubMed1977

[Physiopathological and functional semeiologic considerations in a case of primary normoaldosteronemic hyperaldosteronism].

Among the atypical pictures of primary aldosteronism, sometimes, normal blood and urine concentration of aldosterone have been observed in association with an adrenal aldosterone-producing adenoma. Here we report a case of atypical primary aldosteronism so characterized: -- the patient had the typical clinical findings of aldosteronism (hypertension, hypokalemic alkalosis, polyuria, etc). -- the patient exhibted all the biochemical abnormalities of primary aldosteronism: increase of exchangeable Na and of plasma volume, decrease of exchangeable K, etc. -- the patient had normal blood and urine levels of aldosterone. -- the patient's blood and urine aldosterone concentration increased following sodium depletion and K administration. Such increase was comparable with that obtained in normal subjects after the same tests. However, at the end of these tests, the patient was still in potassium depletion and sodium repletion. Therefore, it was concluded that the secretion of aldosterone, although normal in absolute values, was inappropriate to the metabolic status of the patient, since such "normal" values were found in association with conditions that should have produced an inhibition of aldosterone production. The catheterization of adrenal veins demonstrated the existence of a right adrenal adenoma. The blood pressure and the biochemical parameters of the patients have been normalized by right adrenalectomy.

Adenoma↗