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Biomedical subjects

G Maschio

Publications and source records attributed to G Maschio.

At least 109 records · Page 6Linked to original sources

Dietary problems of the dialysis patient.

The patients on regular dialysis treatment (RDT) usually experience an adaption phase that may sometimes be complicated by intercurrent catabolic episodes before the steady state is reached. In all these clinical settings, and especially during the catabolic episodes, a correct nutritional evaluation is of great importance. The main abnormalities in body composition and metabolism, which may affect the nutritional status in these patients, are reviewed. The caloric intake should provide the ideal amount of 35 kcal/kg b.w., which seems to be critical in maintaining an ideal body weight. A protein intake of 1.0-1.2 g/kg b.w. is adequate to keep a nitrogen balance and to prevent excessive nitrogen-containing waste product accumulation. Carbohydrates should represent 45-50% of total caloric intake and monomeric carbohydrates should be limited. Lipids as 35-40% of total caloric intake are recommended with the polyunsaturated to saturated fatty acid ratio being 1.0. Phosphate intake should not exceed 900-1,200 mg. Calcium supplements are required up to a total intake of 1,500 mg. During the catabolic phases, however, both the caloric and nitrogen intakes should be increased to meet the increased needs of the patients.

Acid-Base Equilibrium↗

Effects of timolol on blood pressure, systemic hemodynamics, plasma renin activity, and glomerular filtration rate in patients with essential hypertension.

Timolol, a non-cardioselective beta-blocking agent, was administered orally after 2 weeks of placebo to 14 patients with essential hypertension for 8 weeks following 1-4 weeks of dose-ranging period. Patients were first hospitalized and submitted to a diagnostic workup. They were placed on a diet containing 100 mEq of Na+ and 65 mEq of K+; this regimen was also prescribed during outpatient treatment. The changes in blood pressure, systemic hemodynamics, plasma renin activity, urine aldosterone, and glomerular filtration rate were evaluated. A significant and stable decrease in systolic and diastolic blood pressure associated with a fall in cardiac output (-21%), heart rate (-17%), plasma renin activity, and urine aldosterone were observed. The blood pressure lowering effect was unrelated to the decrease in cardiac output and plasma renin activity. Glomerular filtration rate was unchanged. No important side effects were observed during the treatment.

Adult↗

Carbohydrate metabolism in patients with nephrotic syndrome and normal renal function.

The effects of a standard oral glucose tolerance test (OGTT) on the serum concentrations of glucose, insulin, growth hormone (GH) and cortisol were evaluated in 38 adult patients with primary nephrotic syndrome and with normal renal function, and in 10 normal subjects. 14 patients had a diabetic-like response and 24 were not different from controls. In both groups of patients an increase in insulin pool secretion, probably due to elevated serum GH levels, was observed. The increased GH values were not related to serum albumin nor to urinary protein losses. No significant difference in serum cortisol values was observed in patients with nephrotic syndrome as compared to controls. There was no strict correlation between the various histologic lesions and the metabolic abnormalities. However, patients with a diabetic-like response to OGTT had a higher frequency of membranous glomerulopathy or focal glomerular sclerosis.

Adult↗

Early dietary protein and phosphorus restriction is effective in delaying progression of chronic renal failure.

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) was prescribed to three groups of patients with chronic renal failure for 6 to 76 months. The mean serum creatinine values were 2.18 mg/dl in group 1 (25 patients), 4.24 mg/dl in group 2 (20 patients), and 6.10 mg/dl in group 3 (8 patients). An additional group of 30 patients (group 4) who had followed no specific dietary treatment for 3 to 72 months was taken as control. The plots of reciprocal serum creatinine against time gave slopes of -0.0008, -0.0010, and -0.0041 in the three groups of patients on the protein-restricted diet, and a slope of -0.020 in the patients on the free diet. The differences between the slopes in patients in groups 1, 2, and 3 versus that in patients in group 4 are statistically significant (analysis of variance and F ratio: P less than 0.01). During the follow-up period a decline in reciprocal serum creatinine greater than the mean values in the whole group was observed in 37.5% of patients in group 3, in 20% of those in group 2, and in only 12% of those in group 1. Thus, the degree of functional renal deterioration is critical in modulating the effects of dietary protein and phosphorus restriction. Several nonimmunologic factors, including hypertension, infection, electrolyte abnormalities, and low-calorie intake, appeared to play an important role in influencing the rate of progression of renal failure in patients on dietary protein restriction.

Adolescent↗

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↗

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↗

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↗

Clinical significance of urinary fibrinogen degradation products in renal disease: study with two methods and correlation with histological findings of intraglomerular coagulation.

The investigation of fibrinogen degradation products (FDP) in urine has been suggested as a reliable method to detect the glomerular deposition of fibrin. Urinary FDP were investigated in 246 patients with renal disease by means of a latex test in 100 of them (positive in 54%); in the remaining 146 patients the Merskey method was used which gave positive results in 26% of them. A significant correlation between urinary protein excretion and FDP was only observed in those patients examined with the latex test. In patients investigated with the Merskey method, the simultaneous determination of serum FDP showed no correlation between FDP values in serum and urine. In those patients studied by means of renal biopsy, a poor correlation was observed between immunofluorescence and electron microscopic evidence of fibrin deposition and urinary FDP. In conclusion, isolated urinary FDP detection is not an index of pathologic coagulation in the glomeruli.

Biopsy, Needle↗

Clinical significance of plasma factor VIII levels in renal disease.

The plasma levels of factor VIII related antigen (FVIIIRA), factor VIII coagulant activity (FVIIIC) and the ratio between them were evaluated in 57 patients with kidney disease of diverse etiology, and with either normal (49) or impaired (8) renal function. Renal biopsy specimens were obtained from 47 patients with normal renal function. No correlation was observed between the increased plasma values of FVIIIRA and FVIIIC and renal function, histologic findings, and the pattern of deposition of immunoglobulin and complement. In contrast, plasma levels of both components of factor VIII were positively correlated with the magnitude of proteinuria. In the authors' opinion, the determination of factor VIII components is of no value in establishing the diagnosis and prognosis of patients with kidney disease. The finding on immunofluorescence of simultaneous deposition of factor VIII and C3 in the arteriolar walls might suggest incipient atherosclerotic damage. The FVIIIRA/FVIIIC ratio was increased in 87% of the patients and particularly in those with membrano-proliferative glomerulonephritis and chronic renal failure; however, the clinical relevance of this finding remains to be elucidated. The significant correlation between the two components suggests that in renal disease a simultaneous aggregation of the two proteins in factor VIII takes place.

Adolescent↗

Recurrence of autonomous hyperparathyroidism in calcium nephrolithiasis.

In a woman with bilateral recurrent calcium nephrolithiasis and hypercalciuria, hypercalcemia developed and she underwent parathyroid surgery, which led to excision of a histologically-confirmed adenoma. The patient became normocalcemic but remained hypercalciuric despite reduction of dietary calcium intake. Several calculi recurred in both kidneys. Four to six years after parathyroidectomy, hypercalcemia recurred and the patient underwent a new surgical exploration; a parathyroid gland with diffuse adenomatous aspects and another gland with pure hyperplasia were excised. Once again, after surgery the patient became normocalcemic but remained hypercalciuric. Evidence for a "renal calcium leak" hypercalciuria was obtained, and thiazide administration led to normalization of urinary calcium excretion. In calcium nephrolithiasis, persistent hypercalciuria may lead to recurrence of autonomous hyperparathyroidism.

Adenoma↗

125I-iothalamate and creatinine clearances in patients with chronic renal diseases.

In 196 adult patients with chronic renal disease or primary hypertension, the evaluation of glomerular filtration rate (GFR) by means of creatinine clearance, 'predicted' creatinine clearance and [125I]-iothalamate clearance was performed. Iothalamate clearance was evaluated after subcutaneous injection of the substance . In patients with normal or upper borderline plasma creatinine values, the iothalamate clearance ranged from 44 to 117 ml/min/1.73 m2 and the overestimation of GFR from creatinine clearance was negligible. In patients with mild or advanced renal failure, the overestimation of GFR from creatinine clearance increased up to 18 and 32%, respectively. The clinical usefulness of iothalamate clearance is evident especially in patients with mild renal failure, in whom an accurate evaluation of GFR is often important for a correct dietary and therapeutic approach.

Adolescent↗