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A Vianello

Publications and source records attributed to A Vianello.

At least 55 records · Page 3Linked to original sources
PubMed1993

Long-term survival on renal replacement therapy for primary hyperoxaluria type I.

We describe the case of a patient in end-stage renal failure due to primary hyperoxaluria type I (PH1) who started hemodialysis in 1977 and is still alive and active. The diagnosis of PH1 was first suspected after a bone biopsy performed in 1981 to investigate hyperparathyroidism. Oxalosis recurred as early as 3 months after transplantation in a cadaver kidney grafted in 1987; nevertheless, graft function remained good enough to make possible the discontinuation of dialysis treatment for 5 months and thereafter to have only 1 dialysis a week for 17 months. The diagnosis of PH1 has been recently confirmed despite the patient being already anuric by means of the determination of plasma oxalate and glycolate levels as well as by determining hepatic alanine:glyoxylate amino-transferase.

Adult↗
PubMed1993

Serum beta-2-microglobulin level and residual renal function in peritoneal dialysis.

In 32 noncirrhotic patients on peritoneal dialysis, mean serum beta 2-microglobulin (s beta 2M) was 26.58 +/- 12.32 mg/l (9.7-63.5). We found a significant correlation between s beta 2M and serum creatinine (sCr; r = 0.760), blood urea nitrogen (BUN; r = 0.573), total creatinine and BUN clearance (r = 0.623 and 0.599, respectively), 24-hour Kt/V (r = 0.638), glomerular filtration rate (r = 0.623), 24-hour urine output (r = 0.669), serum total protein (r = 0.584) (p < 0.01 for all the above r values); beta 2M peritoneal clearance and mass transfer (r = 0.414 and 0.427, respectively; p < 0.05). Our data demonstrate and confirm the contribution of residual renal function in determining s beta 2M levels and it is seemingly more important than beta 2M peritoneal clearance.

Adolescent↗
PubMed1993

Influence of donor age on cadaver kidney graft function and survival: univariate and multivariate analyses.

The influence of donor age on the outcome of kidney transplantation (TX) was evaluated in 169 patients who received a primary cadaver kidney transplant at our center between September 16, 1984, and December 31, 1990. All the patients received cyclosporin A as part of the immunosuppressive protocol. Patients were grouped according to donor age: low donor age (LDA; donor age range 12-25 years), medium donor age (MDA; range 26-50 years) and higher donor age (HDA; range 51-66 years). There were no differences between groups in graft and patient survival, and multivariate analysis did not show any effect of donor age on those parameters. Proteinuria/day and number of rejection episodes did not differ between groups either. Immediate diuresis was more frequent in group LDA than in the other two groups (73.8, 54.7 and 57.1%, respectively; p < 0.05) and immediate diuresis resulted as a weak positive prognostic factor for graft outcome at multivariate analysis (p = 0.05). At both univariate and multivariate analyses, donor age resulted inversely correlated with creatinine clearance (CCr) at every period after TX but the 5th year, with r2 from 0.12 to 0.23 (p < 0.01). The LDA group had significantly better CCr than the HDA group at every period after TX but for the 5th year (the MDA group behaved intermediately).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Electrical potential dissipation induced by free fatty acids in pea stem mitochondria.

Linolenic, linoleic, oleic, palmitic and stearic acids (FFA) collapse the electrical potential of pea stem mitochondria in the absence or in the presence of 0.5 mM Mg2+. Higher concentrations of this cation (5 mM) lower the rate of dissipation caused by linoleic, oleic and palmitic acids, while abolishing that induced by stearic acid. Carboxyatractyloside and ADP do not reverse the FFA-induced collapse both in the presence or absence of Mg2+. EDTA, EGTA or BHT do not influence the dissipation caused by FFA that, in addition, is not linked to lipid peroxidation evaluated as malondialdehyde or conjugated diene formation. Only linolenic acid sustains a peroxidation which, however, appears to be caused by its own oxidation catalysed by lipoxygenases rather than by membrane lipoperoxidation induced by this free fatty acid. These results suggest that neither the ATP/ADP exchanger nor lipid peroxidation appear to be involved in FFA-induced uncoupling in pea stem mitochondria.

Cations, Divalent↗
PubMed1991

Generation of superoxide anion and hydrogen peroxide at the surface of plant cells.

In addition to well-known cell wall peroxidases, there is now evidence for the presence of this enzyme at the plasma membrane of the plant cells (surface peroxidase). Both are able to catalyze, through a chain of reactions involving the superoxide anion, the oxidation of NADH to generate hydrogen peroxide. The latter is oxidized by other wall-bound peroxidases to convert cinnamoyl alcohols into radical forms, which, then polymerize to generate lignin. However, there are other enzymes at the surface of plasma membranes capable of generating hydrogen peroxide (cell wall polyamine oxidase), superoxide anion (plasma membrane Turbo reductase), or both (plasma membrane flavoprotein?). These enzymes utilize NAD(P)H as a substrate. The Turbo reductase and the flavoprotein catalyze the univalent reduction of Fe3+ and then of O2 to produce Fe2+ and O2-., respectively. The superoxide anion, in the acidic environment of the cell wall, may then dismutate to H2O2. These superoxide anion- and hydrogen peroxide-generating systems are discussed in relation to their possible involvement in physiological and pathological processes in the apoplast of plant cells.

Cell Membrane↗
PubMed1990

Hydrogen peroxide formation and iron ion oxidoreduction linked to NADH oxidation in radish plasmalemma vesicles.

Previously, we showed the presence in radish (Raphanus sativus L.) plasmalemma vesicles of an NAD(P)H oxidase, active at pH 4.5-5.0, which elicits the formation of anion superoxide (Vianello and Macrí (1989) Biochim. Biophys. Acta 980, 202-208). In this work, we studied the role of hydrogen peroxide and iron ions upon this oxidase activity. NADH oxidation was stimulated by ferrous ions and, to a lesser extent, by ferric ions. Salicylate and benzoate, two known hydroxyl radical scavengers, inhibited both basal and iron-stimulated NADH oxidase activity. The iron chelators EDTA (ethylenediaminetetraacetic acid) and DFA (deferoxamine melysate) at high concentrations (2 mM) inhibited the NADH oxidation, whereas they were ineffective at lower concentrations (80 microM); the subsequent addition of ferrous ions caused a rapid and limited increase of oxygen consumption which later ceased. Hydrogen peroxide was not detected during NADH oxidation but, in the presence of salicylate, its formation was found in significant amounts. NADH oxidase activity was also associated to a Fe2+ oxidation which was only partially inhibited by salicylate. Ferrous ion oxidation was partially inhibited by catalase and prevented by superoxide dismutase, while ferric ion reduction was abolished by catalase and unaffected by superoxide dismutase. These results show that during NADH oxidation iron ions undergo oxidoreduction and that hydrogen peroxide is produced and rapidly consumed. As previously suggested, this oxidation appears linked to the univalent oxidoreduction of iron ions by a reduced flavoprotein of radish plasmalemma which is then converted to a radical form. The latter, reacting with oxygen generates the superoxide anion which dismutases to H2O2. Hydrogen peroxide, through a Fenton's reaction, may react with Fe2+ to produce hydroxyl radicals, or with Fe3+ to generate the superoxide anion.

Cell Membrane↗
PubMed1990

The organ donor.

Vascularized organ transplantation is now a widely applied therapy for patients with end-stage diseases of the heart, lungs, liver, kidneys, and pancreas. A critical shortage of donor organs exists in the United States and, as a consequence, prospective transplant recipients die while waiting for a life-saving transplant. The apparent shortage of cadaver organs is, in large part, caused by the reluctance and failure of the physician and the public to promote cadaver organ donation. Educational awareness programs for both professional personnel and the public at large are needed to increase the number of potential donors and multiorgan procurements carried out. All victims of trauma with severe closed head injury or cerebrovascular catastrophe secondary to anoxia should be considered as potential organ donors and referred to the local organ procurement agency for evaluation.

Aged↗
PubMed1989

NAD(P)H oxidation elicits anion superoxide formation in radish plasmalemma vesicles.

Radish plasmalemma-enriched fractions show an NAD(P)H-ferricyanide or NAD(P)H-cytochrome c oxidoreductase activity which is not influenced by pH in the 4.5-7.5 range. In addition, at pH 4.5-5.0, NAD(P)H elicits an oxygen consumption (NAD(P)H oxidation) inhibited by catalase or superoxide dismutase (SOD), added either before or after NAD(P)H addition. Ferrous ions stimulate NAD(P)H oxidation, which is again inhibited by SOD and catalase. Hydrogen peroxide does not stimulate NADH oxidation, while it does stimulate Fe2+-induced NADH oxidation. NADH oxidation is unaffected by salicylhydroxamic acid and Mn2+, is stimulated by ferulic acid, and inhibited by KCN, EDTA and ascorbic acid. Moreover, NADH induces the conversion of epinephrine to adrenochrome, indicating that anion superoxide is formed during its oxidation. These results provide evidence that radish plasma membranes contain an NAD(P)H-ferricyanide or cytochrome c oxidoreductase and an NAD(P)H oxidase, active only at pH 4.5-5.0, able to induce the formation of anion superoxide, that is then converted to hydrogen peroxide. Ferrous ions, sparking a Fenton reaction, would stimulate NAD(P)H oxidation.

Cell Membrane↗
PubMed1988

Comparison between three mathematical models of KT/V.

In thirty anuric patients undergoing chronic hemodialysis the KT/V values obtained with the formula: (formula; see text) were compared with the values obtained with the following two formulae: (formula; see text) The results given by formulae B and C differed from those with formula A respectively by 12.81 +/- 11.98% and 10.38 +/- 3.64%. For routine determination of KT/V we suggest the use of formulae A and C as a means of establishing rapidly, in one step, whether the hemodialytic treatment examined is adequate.

Female↗
PubMed1986

Arachidonic acid metabolites in a nephroblastoma associated with paraneoplastic hypercalcemia.

Blood concentration of PGE2, F2a, 6 keto PGF1a (6kF1a), TxB2 and 13, 14 dehydro 15 keto PGE2 (13, 14 OH 15 k E2) were measured in renal artery and vein of a patient with a PGs producing nephroblastoma. The tumor tissue produced PGs in the following order: PGF2a greater than PGE2 greater than TxB2 greater than 6kF1a greater than 13, 14 OH 15 k E2. However, renal artery concentration of the substances were as follows: 13, 14 OH 15 k E2 greater than TxB2 greater than 6kF1a greater than PGF2a greater than PGE2. Since arterial concentration is critical to postulating a calcium mobilizing effect on bone tissue, PGE2 arterial level seems to be too low to exert a pathogenetic role on hypercalcemia, at least in the patient reported here.

Arachidonic Acids↗
PubMed1985

Interactions between muzolimine, PgE2 and the renin-angiotensin-aldosterone system.

UNLABELLED: The aim of our study was to determine the possible interrelation between muzolimine and the renal PG and renin-angiotensin systems by direct assay of these renal hormones. 4 groups of five rats were subdivided as follows: Group 1: controls; Group 2: rats treated with muzolimine (100 mg/kg); Group 3: rats treated with indomethacin (4 mg/kg); Group 4: rats treated with both muzolimine and indomethacin. After 3 days, the rats were transferred to metabolic cages, urine and plasma samples were taken on the 4th day and the following parameters assayed: Urine: creatinine, Na+, PGE2. Plasma: PRA and aldosterone. RESULTS AND CONCLUSIONS: Muzolimine: 1) increase PRA (11.8 +/- 1.06 vs. 8.66 +/- 1.56 AI ng/ml/h - p less than 0.01) and 2) increases PGE2 release (7.08 +/- 3.22 vs. 0.6 +/- 0.19 micrograms/mg urine creatinine - p less than 0.005). PG synthesis-inhibition (indomethacin) lowers (0.118 +/- 0.056 mmol Na+/mg urine creatinine of group 2 vs 0.043 +/- 0.019 mmol Na+/mg urine creatinine of group 4 - p less than 0.025) although not completely abolishes (0.043 +/- 0.019 nmol Na+/mg urine creatinine of group 4 vs. 0.019 +/- 0.006 mmol Na+/mg of group 3 - p less than 0.05) the natriuretic effect of muzolimine. This suggests that the natriuretic activity of the drug, at least in part, depends on PGE2 production.

Animals↗