The US color Doppler in acute renal failure.

Imaging techniques, especially ultrasonography and Doppler, can give an effective assistance in the differential diagnosis of acute renal failure (ARF). An resistance Index (RI) value >0.75 is reported as optimal in attempting differential diagnosis between acute tubular necrosis (ANT) and prerenal ARF. In hepatorenal syndrome (HRS) RIs is very increased. In some renal vasculitis, as nodose panarteritis (PN), hemolytic-uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP), parenchymal perfusion is reduced and RI increased. In lupus nephritis the RI values are correlated with creatinine level and normal RI are considered as a good prognostic tool. In acute primitive or secondary glomerulonephritis (GN), RI value is normal, with diffuse parenchymal hypervascularization. In acute crescentic and proliferative GN and tubulo-interstitial disease, color Doppler (CD) and power Doppler (PD) reveal a decreased renal parenchymal perfusion, which correlates with increased RI values. In acute thrombosis of renal artery, US color Doppler (DUS) reveals either an absence of Doppler signal or a tardus-parvus pulse distal to the vascular obstruction. In this situation it is possible to visualize hyperthropic perforating vessels that redirect their flow from the capsular plexus to the renal parenchyma. In acute thrombosis of the renal vein Doppler analysis of parenchymal vessels reveals remarkable RI values, sometimes with reversed diastolic flow. In postrenal ARF an adjunct to the differentiation between obstruction and non obstructive dilatation can be found through RIs. Diagnostic criteria of obstruction as reported by literature are: RI>0.70 in the obstructed kidney and, mostly, a difference in RI between the 2 kidneys >0.06-0.1.

[Chronic renal failure and tuberous sclerosis. Report of two clinical cases]. / L'insufficienza renale cronica avanzata nella sclerosi tuberosa. Descrizione di due casi clinici.

Tuberous sclerosis complex (TSC) is an autosomal dominant hereditary disease characterized by a high rate of spontaneous mutations involving at least two loci: TSC(1) (9q34) and TSC(2) (16p13). It results in hamartomas or tumours which can affect a variety of organs, most commonly the brain, skin and kidneys. At least half of patients with TSC have underlying renal pathology, most commonly angiomyolipomas (AML) and/or cysts with, more rarely, adenocarcinoma, but oncocytomas, sarcomas, interstitial fibrosis and glomerulosclerosis have all been reported. Renal disorders may be asymptomatic or associated with acute lumbar ache, hematuria, abdominal mass, retroperitoneal hemorrhage. Renal failure is infrequent. The diagnosis of this disease is often performed, as in the present cases, very late and it is made possible by radiological examinations such as TC scan o RMI (when renal failure is present), usually performed after macrohaematuria or abdominal or renal colics or renal failure. When fatty tissue cannot be demonstrated within renal lesion (as in the female case), biopsy can be undertaken to exclude malignancy. Histology at the edge of an AML may look like renal carcinoma, but recent studies suggest that it can be differentiated by staining for HMB-45 which is positive in AML and negative in carcinoma. Two cases of tuberous sclerosis with different neurological fenotype, with bilateral renal angiomyolipomatosis and heavy renal failure, are presented.

End-stage renal failure from renal amyloidosis of the AA type associated with giant lymph node hyperplasia (Castleman's disease).

A case of end-stage renal failure caused by renal amyloidosis of the AA type is reported. No chronic disease responsible for the deposition of reactive amyloid was detected until giant lymph node hyperplasia of the angiofollicular type was identified in a mediastinal mass. Amyloid was found within the tumour mass and was characterized by immunochemistry with monoclonal antibodies to be of the AA type. Castleman's disease should be added to the list of chronic diseases endangering renal function by inducing the production and tissue deposition of secondary (AA) amyloid.

[Plasma malondialdehyde in patients with chronic renal insufficiency undergoing hemodialytic treatment]. / Malondialdeide plasmatica in soggetti con insufficienza renale cronica in trattamento emodialitico.

To verify the hypothesis of a possible involvement of free radicals of oxygen in some aspects of chronic renal failure, authors have executed, by high resolution liquid chromatography (HPLC), the measurement of plasmatic malondialdehyde (MDA) in 15 patients with chronic renal failure undergoing haemodialysis and in 15 healthy control subjects. The two groups were comparable for sex and age. Statistical analysis of the two groups resulted significant (p < 0.05). These results are according to literature data and show a problem of oxidative metabolism in subjects with chronic renal failure undergoing haemodialysis also if it might be useful to investigate the question with wider enumeration of cases, to clarify better the clinical significance of these alterations and to point out eventual correlations.