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Biomedical subjects

A Borghetti

Publications and source records attributed to A Borghetti.

At least 109 records · Page 6Linked to original sources
PubMed1982

Muscle tissue electrolytes in burned subjects.

In a group of patients with burns covering at least 20 per cent of their body surface area (BSA), extracellular electrolytes and acid-base status and intracellular electrolytes and nitrogen (muscle needle biopsy) were measured both in the early phase (12-24 hours) and 7-14 days after burn injury. In the acute burn phase, extracellular electrolyte and acid-base disturbances are uncommon, while intracellular data shows increase of muscle sodium, decrease of muscle potassium and magnesium and normal muscle cell nitrogen. In the later burn phase, despite an adequate fluid, electrolyte and protein-calorie supply, the changes of electrolytes appear to be uncorrected; no decrease of muscle cell nitrogen is found. Our data could suggest that defects of the sodium-potassium pump in the cell membrane, which are thought to be the cause phase of burns, do not ameliorate with adequate fluid and protein-calorie intake; however, a persistent muscle potassium depletion is also consistent with a reduction of cell "capacity' for potassium, possibly due to muscle protein catabolism, although muscle cell protein values do not show a significant reduction.

Acid-Base Equilibrium↗
PubMed1982

[Effects of passive semiorthostatic cardiopulmonary hematic centralization (by immersion in water) on hydrosaline elimination and on the renin-angiotensin-aldosterone system in essential hypertension].

In 25 patients with essential hypertension and 9 control subjects we have studied the effects of central hypervolemia during water immersion on both renin-angiotensin-aldosterone system and renal function (diuresis volume and urine excretion of Na, k and osmoles). Reduction of blood pressure, plasma renin activity and aldosterone was found to be similar in both groups; renal excretion of water, Na, K and osmoles was significantly higher in the hypertensive group compared to the controls. These urinary features may be related to a reduced proximal tubular reabsorption by cardiorenal reflex due to cardiopulmonary volume receptors stimulation without any change of GFR measured as the creatinine clearance. The urinary pattern, observed during water immersion in hypertensive group without any change of plasma sodium, osmolality or protein concentration, was comparable to "exaggerated natriuresis"; this may suggest that also "exaggerated natriuresis" is due either to renal vasodilatation or to renal tubular sympathetic activity reduction secondary to a cardiorenal reflex by cardiopulmonary volume expansion.

Adolescent↗
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 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

Nephrotoxicity of chromium. Remarks on an experimental and epidemiological investigation.

Observations conducted on a group of workers exposed to chromium (who showed a rapid urinary excretion of the metal and progressive increase of clearance with cumulative years of exposure), induced the authors to evaluate the nephrotoxic action of chromium in rats exposed to acute and chronic intoxication. The progressive Cr accumulation in the renal cortex during the course of testing explains the increase of the excreted fraction of filtered Cr, and therefore, the clearance, of the metal through the reduction of the tubular lumen-epithelium gradient. Paralleling the anatomical lesions (demonstrated only at the level of the proximal tubular cells), are the increasing modifications of the cellular lesion or altered reabsorption registered by several urinary indicators. Similar changes were found in subjects chronically exposed to the metal; their reversibility is linked to the possibility of repairing the epithelial damage by stopping exposure.

Animals↗
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↗
PubMed1978

[Relation between environmental concentration, urinary elimination and body burden of chromium in occupationally exposed workers].

Biological and environmental monitoring of chromium exposure was carried out on 20 welders working with special electrodes in the manufacture of tank-cars. The workers were divided in groups, according to the different degree of chromium accumulation, which was determined by renal clearance of diffusible chromium. A closed linear relationship between TWA concentration of hydrosoluble chromium in air and urinary excretion of the metal at the end of exposure was observed. The parameters of regression lines in welders with more (clearance 10 ml/min) or less (clearance 5 ml/min) accumulation of chromium suggest that the renal burden influences not only the basal excretion, but also the excretion at the end of exposure. We underline the difficulty in the determination of correct biological limits if we take them from TLV in air. We must at least consider the degree of accumulation in exposed workers too.

Air Pollutants↗