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Biomedical subjects

E Valvo

Publications and source records attributed to E Valvo.

At least 55 records · Page 3Linked to original sources

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↗

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↗

Haemodynamics of stable renal transplant recipients.

1. Haemodynamics, blood volume, plasma renin concentration and creatinine clearance were evaluated in 24 stable renal transplant recipients. 2. The mean cardiac index of the transplant recipients was not different from that of the normal subjects. 3. The transplant recipients comprised eight hypertensive and 16 normotensive patients. The mean cardiac index was the same in eight hypertensive and 16 normotensive patients. Thus the hypertension of stable renal transplant recipients is sustained by a high total peripheral resistance. 4. The mean blood volume, plasma renin concentration and creatinine clearance were similar in eight hypertensive and 16 normotensive patients. Therefore the hypertension of stable renal transplant recipients is not related to blood volume expansion, elevated peripheral renin or low creatinine clearance. The cause of the elevated total peripheral resistance in hypertension in stable renal transplant recipients remains to be elucidated.

Adolescent↗

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↗

Renal tubular defects in recurring bilateral nephrolithiasis.

A metabolic study was performed in 28 patients with bilateral recurrent calcium-containing renal staghorn calculi and chronic pyelonephritis ("obstructive nephropathy"). Fourteen had normal GFR and 14 mild renal insufficiency. Ten normal subjects were used as controls. Under basal conditions, polyuria and negative sodium balance were commonly observed in patients with obstructive nephropathy and normal renal function. After an acute acid load (NH4Cl) an acidifying defect, i.e. high values for urine pH and reduced excretion of titratable acid and ammonium, was observed in 64% of patients with normal GFR and in 71.4% of those with renal insufficiency. During intravenous infusion with neutral sodium phosphate, the urine pH changed little but the rate of excretion of titratable acid increased in direct proportion to that of urinary phosphate in both groups of patients. These results, associated with the finding of normal blood pH in almost all patients, lead to the conclusion that an incomplete Type 1 or "distal" renal tubular acidosis is a frequent complication of obstructive nephropathy secondary to bilateral nephrolithiasis. The anatomical abnormalities of renal tubules and collecting ducts and the superimposed interstitial nephritis might be the pathogenetic factors responsible for the acidifying defect and for the impairment in sodium and water conservation.

Acidosis, Renal Tubular↗

Alterations in renal tubular sodium and water transport in polycystic kidney disease.

Thirty patients with chronic renal diease -10 with polycystic kidney disease (PKD) and normal GFR; 10 with PKD and GFR is less than 30 ml+min; 10 with chronic glomerulonephritis (CGN) and GFR is less than 30 ml+min -and 10 normal subjects were investigated. The ability to concentrate urine maximally (T-CH2O) after water deprivation and the renal handling of water and electrolytes following hypertonic volume expansion were studied. A defect in T-CH2O was common in PKD patients even with normal GFR. In PKD patients with normal GFR, volume expansion was not followed by a natriuretic effect of the same magnitude as in controls. This ""inadequate natriuresis after volume expansion"" may be explained partly by chronic hyponatremia and partly by a functional defect, i.e. the incomplete arterial vasodilation in the kidney. At comparable degrees of renal insufficiency, T-CH2O was lower in PKD than in CGN patients. It seems likely that in PKD patients the increased endogenous osmotic load has exaggerated the tubular defect in urine concentration already present at normal GFR. Furthermore, volume expansion was followed by a significant increase in fractional sodium excretion only in PKD patients with renal insufficiency.

Adult↗