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Biomedical subjects

A Fabris

Publications and source records attributed to A Fabris.

At least 73 records · Page 4Linked to original sources
PubMed1982

Effects of dietary protein and phosphorus restriction on the progression of early renal failure.

Three groups of patients with chronic renal failure were studied. Group 1 comprised 25 patients with a mean serum creatinine of 2.18 mg/dl and a mean arterial pressure of 117 mm Hg. Group 2 had 20 patients with a mean serum creatinine of 4.24 mg/dl and a mean arterial pressure of 119 mm Hg. All these patients were kept for 18 to 76 months on a diet containing about 40 kcal/kg, 0.6 g/kg of protein, 700 mg of phosphorus, and 1,000 to 1,500 mg of calcium (orally supplemented). Group 3 comprised 30 patients with a mean serum creatinine of 2.28 mg/dl and a mean arterial pressure of 116 mm Hg. They had followed no specific dietary regimen for 3 to 72 months, and their dietary calorie, protein, phosphorus, and calcium intakes averaged 35 kcal/kg, 70 g, 900 mg, and 800 mg, respectively. The plots of reciprocal creatinine against time gave slopes of -0.0008 and -0.0010 in patients in groups 1 and 2, and a slope of -0.020 in group 3 patients. The slopes of both groups 1 and 2 were statistically different (analysis of variance and "F" test, P less than 0.01) from that of group 3. No evidence of progressive protein and phosphorus depletion was observed in groups 1 and 2 patients. We conclude that a moderate dietary restriction of protein and phosphorus is an acceptable and effective regimen for delaying progression of functional deterioration in early renal failure.

Adolescent↗
PubMed1982

Medullary sponge kidney and hyperparathyroidism--a puzzling association.

28 adult patients with radiological evidence of medullary sponge kidney (MSK) were studied. Hypercalcemia and increased serum parathyroid hormone (PTH) values were found in 10 patients (36%). In 7 of them, parathyroid surgery was performed: a single adenoma was found in 6 cases and multiple-gland hyperplasia in 1 case. After surgery, 3 patients had normalization of calcium metabolism; 4 patients had persistence of hypercalciuria with progressive increase in serum PTH values (and recurrence of the adenoma in 1 case). Of the remaining patients, 10 (36%) had definite or marginal hypercalciuria, resulting from renal calcium leak in 8 and from intestinal calcium hyperabsorption in 2 of them. In 8 patients (28%), no evidence of disordered calcium metabolism was found. The association of MSK and hyperparathyroidism is not a chance occurrence. MSK might be a renal anatomical complication of primary hyperparathyroidism, or it might be regarded as an anatomic substrate--or rather as a consequence--of prolonged hypercalciuria, regardless of its pathogenesis. The lack of disordered calcium metabolism in a considerable number of patients, however, shows that the enigma of MSK is still far from being solved.

Adenoma↗
PubMed1982

Studies on brain density in hemodialysis and peritoneal dialysis.

30 patients on hemodialysis or peritoneal dialysis have been investigated by computerized tomographic (CT) scan. To evaluate possible cerebral alterations induced by dialysis, CT examinations were carried out before, immediately after and 6 h after the end of dialysis with an Evaluskop, which provides an objective precise evaluation of even slight variations in brain density. No morphological variations were noted after dialysis, while the brain density fell significantly during and after the treatment. A decrease in density was not observed in normal subjects or in patients on continuous peritoneal dialysis. The changes in the densitometric values of brain tissue suggest that there is a postdialysis gain in cerebral water linked to the intermittent treatment. CT may represent a simple reliable method for studying uremic encephalopathy and investigating the pathogenesis of the dialysis disequilibrium syndrome.

Adolescent↗
PubMed1982

Anatomical bases of peritoneal permeability: a reappraisal. Anatomy of peritoneum.

The peritoneal membrane consists of flat mesothelial cells linked together with digitations and containing vesiculae with pinocytic capacity, of endothelial cells (containing Weibel-Palade's bodies and vesiculae) and of an interstitial tissue consisting of a network of watery channels. The cellular structures of mesothelium and endothelium are characterized by tight and gap junctions or perhaps by macular junctions. The visceral peritoneum shows a prevalence of gap junctions, the pericysic veins contain only tight junctions while both types can be found in the arterioles. Two different ways for solute transport are theoretically possible: the vesicles of plasmalemma (via pinocytosis) and the junctions (via size-sieving effect). Studies with tracers did not furnish unequivocal data on this problem and did not clarify if these structures could be the equivalent of the pores of the Landis-Pappenheimer's theory. The studies of Karnowsky and Simionescu, using tracers, have in fact given opposite results.

Animals↗
PubMed1982

Pharmacokinetics of intravenous and intraperitoneal cefuroxime during peritoneal dialysis.

We investigated the pharmacokinetics of cefuroxime sodium, a new parenteral beta-lactam antibiotic, in 15 patients with stable chronic renal failure during intermittent peritoneal dialysis (IPD). Eight patients were administered 1 g cefuroxime as an intravenous bolus 1 h before the start of dialysis. Mean plasma levels of cefuroxime fell from 80 mcg/ml at 1 h to 40 mcg/ml at 6-8 h. At 24 h, concentrations were higher than 20 mcg/ml. In peritoneal fluid cefuroxime reached 16.7 mcg/ml at 1 h and 7.55 mcg/ml at 6 h. Seven patients received cefuroxime added to the dialysis solution at a dose of 2.5 g/10 liters. After 6 h of dialysis, cefuroxime reached plasma levels of 60 mcg/ml; after 24 h, concentrations were 37.5 mcg/ml. These results demonstrate that cefuroxime, administered by the i.v. route, easily diffuses from blood to peritoneal fluid and, from peritoneal fluid to blood when added to the dialysis solution. In both cases concentrations reached by cefuroxime are sufficient to treat peritoneal infections associated with peritoneal dialysis.

Adult↗
PubMed1981

Functional renal involvement in normotensive patients with progressive systemic sclerosis: impaired sodium excretion during isotonic saline infusion.

An intravenous infusion of 2,000 ml isotonic saline was performed in 8 normotensive, normoreninemic patients with progressive systemic sclerosis. None of them had clinical evidence of renal disease. Total and proximal fractional excretion of sodium was reduced when compared with that of 8 normal subjects. No correlation was found with para-aminohippurate (PAH) clearance values. Two years after this study was done, 4 patients developed arterial hypertension; interestingly, plasma renin activity remained within the normal range. Reduced sodium excretion is suggested as having a pathogenetic role in the hypertension of progressive systemic sclerosis.

Adolescent↗
PubMed1981

Prevention of calcium nephrolithiasis with low-dose thiazide, amiloride and allopurinol.

We report 5 years' experience with low-dose hydrochlorothiazide, 50 mg/day and amiloride, 5 mg/day, in 519 patients with recurrent calcium nephrolithiasis. Additional treatment with allopurinol, 100 mg/day was prescribed for approximately 50 percent of the patients. All patients had active stone formation, having 3,464 stones in 3,126 patient-years (6.67 stones per patient, 1.10 stones per year). Hypercalciuria was present in 65 percent of the patients and hyperuricosuria in 24 percent. The administration of low-dose hydrochlorothiazide was effective in reducing urinary calcium excretion in most patients. It is possible that the hypocalciuric effect of hydrochlorothiazide were enhanced by amiloride, an agent which has been shown to cause hypocalciuria when given alone. Significant side effects requiring discontinuation of the drug were observed in only 5 percent of the patients. During 872.8 patient-years of treatment, only 53 new stones were formed (0.10 stones per patient, 0.06 stones per year) in contrast with the 916 predicted ones. The difference (chi-square) is statistically significant (p less than 0.001). These results show that the administration of low-dose hydrochlorothiazide and amiloride, either alone or in association with allopurinol, is clinically effective in reducing the rate of recurrence of calcium nephrolithiasis.

Adult↗
PubMed1981

Renal handling of sodium and water in early chronic liver disease. Evidence for a reduced natriuretic activity of the cirrhotic urinary extracts in rats.

Acute expansion of extracellular fluid volume during maximal water diuresis was induced in 8 chronic liver disease patients without clinical evidence of fluid retention, and in 8 controls. Fractional reabsorption of sodium was inferred in the proximal tubule, in the ascending limb of Henle's loop, and in the more distal site of the tubule. The results indicate that the significantly reduced increment of sodium excretion in cirrhotic patients was due to its augmented reabsorption in the proximal tubule. To establish whether there was a reduced activity of a natriuretic factor, a biologic assay was performed in 16 albino Wistar rats by using urine samples collected immediately after completion of a saline load and processed with gel filtration. The infusion of this fraction resulted in a significant lowering of the increment of urine output, and absolute and fractional sodium excretion only in the rats infused with urine extracts from cirrhotic patients. The results of this study raise the possibility that a reduced production of a natriuretic factor may play some role in the pathogenesis of sodium retention, which is observed in patients with cirrhosis of the liver.

Animals↗
PubMed1981

Acid-base balance on peritoneal dialysis.

Forty studies of acid-base balance during intermittent peritoneal dialysis (IPD) and during continuous ambulatory peritoneal dialysis (CAPD) were performed on 20 patients who were receiving IPD with acetate buffer (5 patients), IPD with lactate buffer (5 patients), CAPD with acetate buffer (5 patients) and CAPD with lactate buffer (5 patients). Measurements of acetate, lactate and pyruvate levels in blood and dialyzate were taken at different times during dialysis; blood samples for blood gas analysis were drawn at the same times. Calculations of the kinetics of acetate, lactate and bicarbonate during IPD and CAPD were carried out according to the method of Tolchin [1977] but modified for PD. Thus it was possible to quantify the balance of the buffers, their mass transfer rates, bicarbonate generation and the percentage of buffer converted to HCO3. IPD kinetics of acetate and lactate were found to be similar, the main difference being a lower and significant percentage conversion of lactate to bicarbonate (45%) compared to that of acetate to bicarbonate (71%) (P < 0.005). On CAPD the kinetics of the two buffers was quite different: while the serum lactate level was always low (mean 0.97 +/- 0.33 mM/l), the acetate level was always high (mean 5.12 +/- 3.34 mM/l). Thus the utilization of the two buffers during "acute intermittent" treatment (IPD) and "continuous" treatment (CAPD) is different. On IPD there are no important differences between the two buffers, whilst on CAPD lactate seems to be better and safer than acetate; for instance, serum HCO3 values are relatively constant with lactate (27.7 +/- 2.13 mM/l) while with acetate there is a trend to exceed physiological values (29.5 +/- 1.7 mM/l). When acetate is used in the dialyzate for CAPD the concentration must be less than 38.5 mM/l.

Acetates↗
PubMed1976

Experience with a new vascular prosthetic device (Sparks mandril) for periodic haemodialysis.

In eighteen months, eleven Sparks mandrils have been implanted in ten patients who presented serious vascular access problems. So far nine mandrils have been anastomosed and six are functioning. In one patient the apparatus, inserted in the right leg, clotted after 108 dialyses and was reinserted in the left arm; after a further forty dialyses the patient died from causes not connected with dialysis. Another patient's Sparks mandril thrombosed from infection on the fourth post-operative day. Using a single needle apparatus, 693 dialyses have been carried out with particular problems either for the patients or the grafts.

Adult↗