Search PubMed⌕ Search

Biomedical subjects

R Gusmano

Publications and source records attributed to R Gusmano.

At least 73 records · Page 4Linked to original sources
PubMed1994

[IgA serology in idiopathic IgA deposit nephropathy in children].

It is generally thought that in primary IgA nephropathy (IgAN) an altered immune response favours high levels of serum IgA directed against environmental or mesangial antigens (Ag) leading to circulating IgA containing immune complexes (IgAIC). The aim of this multicenter collaborative study was to evaluate some of the IgA immunologic abnormalities in children with IgAN. We investigated 42 children with biopsy-proved IgAN, 21 children with non-IgA glomerulonephritides (CD) and 15 with previous urologic disorders without any evidence of immunologic disease (U). The following methods were used: detection of macromolecular IgA (IgAIC by the conglutinin solid-phase assay, heavy MW IgA measured in 2.5% polyethylene glycol precipitate, IgA-fibronectin aggregates, mixed IgA-IgGIC); serum levels of IgA to alimentary Ags (gliadin, glyc-gli, ovalbumin, bovine serum albumin) and mesangial Ags (fibronectin, laminin, type IV collagen) and reactivity of IgA with the lectin jacalin. In children affected with IgAN serum levels of macromolecular IgA were significantly higher in comparison to U group (p < 0.05-p < 0.0005). IgA-fibronectin aggregates only were significantly higher also than CD group (p < 0.0005). Mean levels of antigliadin IgA were significantly higher in IgAN than in controls (CD p < 0.01 and U p < 0.03) and similar data were found for IgA to mesangial matrix (laminin and fibronectin), which were significantly greater in IgAN than in CD and U (p < 0.01-p < 0.0002). Serum IgA in children with IgAN showed a greater affinity for both polycations and glycosylated molecules. Children affected by IgAN present abnormalities in serum IgA similar to those observed in adults with the same disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Reversible tubular proteinuria precedes microalbuminuria and correlates with the metabolic status in diabetic children.

Early tubular alterations were studied in 53 children with insulin-dependent diabetes mellitus (IDDM), 32 of whom were followed at regular 6-monthly intervals for 3 years. The urinary levels of retinol-binding protein (RBP), beta 2-microglobulin and brush border antigens (BBA) (determined by monoclonal enzyme immunoassay) were taken as indices of functional and cellular tubular alterations; urinary albumin was considered an early marker of glomerular alterations. All indices of tubular alterations were higher in IDDM children than in 368 normal children, while albuminuria was unchanged. Urinary levels of BBA, however, varied widely during follow-up, with 25 of the 32 IDDM patients who were followed at regular intervals having pathological values for BBA on at least one occasion, followed by normalization. Metabolic alteration was found to be the main cause of this variability, since a high statistical correlation was found between urinary BBA and fructosamine (P < 0.001) and between RBP and the stable fraction of glycosylated haemoglobin (P < 0.001). The data confirm that transient tubular proteinuria occurs in diabetic children before any other marker of renal involvement such as microalbuminuria. The maintenance of good metabolic control is essential to normalize this early abnormality that can be considered a reversible sign of functional renal involvement.

Adolescent↗
PubMed1993

A randomized trial of cyclosporine in steroid-resistant idiopathic nephrotic syndrome.

To compare the efficacy (induction of remission) and safety of cyclosporine (CsA) with those of supportive therapy in patients with steroid-resistant idiopathic nephrotic syndrome (INS), we organized an open, prospective, randomized, multicentric, controlled study for parallel groups, stratified for adults and children. Forty-five patients with steroid-resistant INS were randomly assigned to supportive therapy or CsA (5 mg/kg/day for adults, 6 mg/kg/day for children) for six months, then tapered off by 25% every two months until complete discontinuation. Four patients were lost to follow-up. During the first year 13/22 CsA-treated patients versus three of 19 controls attained remission of the nephrotic syndrome (P < 0.001). A symptom score was assessed at time 0 and at six months. The mean score significantly decreased in the CsA group (P < 0.001), but remained unchanged in the controls. At month 6 the mean urinary protein excretion, the mean serum proteins and plasma cholesterol had significantly improved in the CsA group but were not changed in the controls. There were no significant differences in serum creatinine and creatinine clearance between treatments (interaction time* treatments, P = 0.089 and P = 0.935, respectively) at month 6 versus basal. The CsA-related side-effects were mild; no significant difference in blood pressure between the two groups was seen at any time. This study shows that CsA can bring about remission in some 60% of patients with steroid-resistant INS. In patients with normal renal function and without severe hypertension, CsA at the therapeutic scheme adopted did not produce severe renal or extrarenal toxicity.

Adolescent↗
PubMed1993

Proteolytic activity and free amino acid concentrations in polymorphonuclear leucocytes.

Polymorphonuclear granulocytes (PMN) are valuable tools for evaluating amino acid (AA) metabolism in nucleated cells, although variations of free amino acid concentrations due to the methods used for the separation of the cells and the procedures used for lysis have been reported. Furthermore, analytical variations in PMN AA concentration may be induced by protease activation during preparation, so that free AA detected in cells could originate from proteolysis other than from the physiological metabolic pathways and transport systems. To study this possibility we measured granulocyte protease activity and AA concentrations in cell suspensions processed with and without the addition of antiproteolytic agents. Granulocyte AA concentrations and protease activity in samples treated with antiproteolytics were 8-15 times lower than in samples processed without antiproteolytics. The use of protease inhibitors throughout the sample preparation is necessary for reliable estimation of free AA in granulocytes.

Amino Acids↗
PubMed1993

Cyclosporin versus cyclophosphamide for patients with steroid-dependent and frequently relapsing idiopathic nephrotic syndrome: a multicentre randomized controlled trial.

OBJECTIVE: To compare the efficacy (maintenance of remission), safety and tolerability of cyclosporin (CsA) with those of cyclophosphamide in patients with steroid-dependent or frequently relapsing nephrotic syndrome (NS). DESIGN: Open, prospective, randomized, multicentre, controlled study for parallel groups, stratified for adults and children. The setting was in nephrological departments in Italy. SUBJECTS AND INTERVENTIONS: Seventy-three patients with steroid-sensitive idiopathic NS admitted to the study were randomly assigned to cyclophosphamide (2.5 mg/kg/day) for 8 weeks or CsA (5 mg/kg/day in adults, 6 mg/kg/day in children) for 9 months, tapered off by 25% every month until complete discontinuation at month 12. Seven patients lost to follow up were not considered in the analysis. The remaining 66 patients were followed up for 3-24 months after randomization. MAIN OUTCOME MEASURES: Relapse-free survival; number of N.S. relapses/patient/year; cumulative dose of prednisone/patient; laboratory investigations (kidney and liver functions, haematological parameters); incidence of adverse events. RESULTS: At month 9, 26 of 35 CsA-treated patients were still in complete remission and a further five patients were in partial remission; 18 of 28 cyclophosphamide-treated patients were in complete remission, and one in partial remission (P = NS). No difference between adults and children was seen with either treatment. The risk of relapse was similar between frequent relapsers (19 of 22) and steroid-dependent patients (8 of 14) given CsA, and those given cyclophosphamide (5 of 15 and 6 of 15). The mean number of relapses per year and the mean dose of prednisone per year were significantly less (P < 0.001) in both groups for the experimental year than for the year before randomization. At 2 years, 25% of the patients given CsA (50% adults and 20% children) and 63% of those given cyclophosphamide (40% adults and 68% children) had not had any relapse of NS. Tolerance to the two drugs was generally good. The CsA-related side-effects were mild and disappeared after drug discontinuation. CONCLUSIONS: This study shows that both treatments are effective and well tolerated; more patients given cyclophosphamide had stable remissions.

Adolescent↗
PubMed1993

Worldwide demographic aspects of chronic renal failure in children.

Incidence of chronic renal failure in children is not yet clearly known. In recent years it has been evaluated on the basis of the number of patients accepted into dialysis-transplantation programs and is thus underestimated, as registries do not list children who are not treated for technical reasons, lack of facilities or health policy. The number of new patients per year per million child population varies widely. Differences among countries are mainly related to economic development. In developed countries the incidence of CRF remains stable or decreases slowly owing to early diagnosis, improved conservative treatment, prevention of genetically-transmitted diseases, whereas the prevalence increases steadily as a consequence of improved replacement therapy. Causes of primary renal diseases have been analyzed in several series totaling over 9400 children. The most frequent cause is chronic primary glomerulonephritis followed by pyelonephritis, including obstructive uropathies and vesico-ureteral reflux. Differences in geographical distribution of etiologies are also analyzed. The relative contribution of chronic peritoneal dialysis and hemodialysis in the treatment of children with ESRF varies from country to country. Several problems regarding CRF in children are briefly discussed: prevention of renal failure, extension of treatment opportunities to more children, quality of replacement therapy, and clinical rehabilitation of children.

Child↗
PubMed1992

Multiple mechanisms for doxorubicin cytotoxicity on glomerular epithelial cells 'in vitro'.

This study was planned to define the metabolic pathways for free radical production by isolated glomeruli and glomerular epithelial cells in vitro after exposure to cytotoxic doses of doxorubicin. A net increment in glomerular superoxide anion (O2.) synthesis was observed at doxorubicin doses between 10 and 30 micrograms/ml, a drug level which also induced a parallel increment in uric acid synthesis. Since the synthesis of O2. with production of uric acid implies an activity of xanthine oxidase, a few experiments were performed with glomeruli which had been deprived of xanthine oxidase activity. In this case doxorubicin-inducible O2. and uric acid synthesis by glomeruli was practically nil. A similar stimulatory effect of O2. synthesis was induced by doxorubicin on glomerular epithelial cells and also in this case O2. synthesis was suppressed by pre-treating cells with deoxyconformicin, a selective inhibitor of adenosine deaminase. Finally, equimolar amounts of the drug were equally cytotoxic even when kept constantly outside the cell by a stable linkage with an agarose macroporous bed. In summary, these data demonstrate that O2. is generated by isolated glomeruli and glomerular epithelial cells 'in vitro' when exposed to cytotoxic amounts of doxorubicin and that purine degradation to uric acid furnish the metabolic pathways for glomerular O2. generation. However, doxorubicin is comparably cytotoxic on glomerular epithelial cells from outside cells thus suggesting that also a membrane perturbation may activate the series of events leading to cell injury.

Adenosine Deaminase↗
PubMed1992

Urinary excretion of brush border antigens and other proteins in children with vesico-ureteric reflux.

This study was designed to evaluate the occurrence and the type of proteinuria in 82 children with vesico-ureteric reflux (VUR) with or without renal scars. The urinary excretion of the high molecular weight protein albumin was taken as an index of glomerular alterations and the excretion of retinol-binding protein (RBP), beta 2-microglobulin and brush border antigens (BBA) (measured by monoclonal antibody-based enzyme-linked immunosorbent assay) was taken as an index of tubular alterations. All such markers were increased in children with VUR and were related to the degree of renal function. Patients showing reduced creatinine clearance had very high levels of albuminuria, microproteinuria and BBA, with all these variables reciprocally correlated. In children with normal renal function however, only microproteins (not albumin or BBA) were slightly increased, thus indicating an isolated tubular defect without involvement of the proximal segment of the tubule. However, microprotein excretion did not correlate with the grade of scarring (99mtechnetium-dimercaptosuccinic acid scan), both RBP and beta 2-microglobulin excretion being normal in 75% of children with radioisotopic signs of renal lesions but increased in 17% of children without scars. Therefore, tubular proteinuria identifies different groups of children with VUR but is not related to renal scarring. Prospective studies will define the usefulness of proteinuria as a reliable indicator of renal outcome.

Adolescent↗
PubMed1992

Energy and nutrient intake of patients with mild-to-moderate chronic renal failure compared with healthy children: an Italian multicentre study.

Nutritional counselling is important in the management of children with chronic renal failure (CRF). In 1988, a controlled European multicentre study was started to evaluate the effects of a low-protein diet on the progression of CRF in children. To assess the energy, macro- and micronutrient intake, 4-day weighed dietary records were obtained from 50 children with low to moderate CRF (creatinine clearance 65 to 15 ml/min per 1.73 m2) and from 93 healthy children. The mean energy intake was 90%-93% of the recommended dietary allowance for Italian children in controls and 76%-88% in CRF patients. The mean protein intake was 2.1-3.1 g/kg per day in controls and 1.6-2.7 g/kg per day in CRF patients. Overall, the energy intake was 10% and the protein intake 33% lower in CRF patients than in healthy children. Children with CRF consumed less cholesterol, calcium and phosphorus than healthy children. The lower spontaneous intake of energy, protein and other nutrients should be taken into account when planning the nutrition of children with CRF.

Child↗
PubMed1992

Extracellular matrix formation by epithelial cells from human polycystic kidney cysts in culture.

Cells from the cysts of patients with autosomal dominant polycystic kidney disease (PKD) were grown in vitro under standard conditions without the aid of collagen-pretreated surfaces, and both the synthesis and composition of the extracellular matrix were investigated. At confluence, PKD cells presented the typical features of epithelial cells, but showed a different collagen composition from fibroblasts. Compared with normal tubular epithelia (NTE), PKD monolayers produced an excess of extracellular matrix, which accounted for 30% of the total incorporation of [3H] proline, although this value was considerably lower (by a factor of 10) in the case of NTE. Immunohistochemical and electrophoretic techniques revealed a complex collagen composition in the extracellular matrix which included [alpha (III)]3 and collagen IV. However, part of the collagen components remained unidentified in spite of the fact that they exhibited a typical M(r) of alpha 1(I) and alpha 2(I) in the presence of urea. Immunoprecipitation with monospecific antibodies and Northern blotting with specific probes failed to recognize alpha 1(I) and alpha 2(I), but demonstrated their presence in fibroblasts. Purification and cyanogen bromide digestion demonstrated a strong interhomology in fingerprint peptide composition among the uncharacterized collagens synthesized by PKD cells, thus suggesting a common identity. These observations document a markedly augmented production of extracellular matrix by PKD cultured cells in vitro, and show the presence of collagens which do not share homologies with the major collagen molecules. A better characterization of extracellular matrix composition is central to any comprehension of the cytogenetic mechanisms in vivo.

Adult↗
PubMed1992

Delayed puberty in uremia: pituitary-gonadal function during short-term pulsatile luteinizing hormone-releasing hormone administration.

Pubertal development is frequently delayed or disordered in children with chronic renal failure. Both neuroendocrine and peripheral alterations due to uremia have been hypothesized to explain the impairment in the pituitary gonadal axis. The aim of the present study was to evaluate quantitative (immunological) and qualitative (biological) LH secretion, as well as FSH and sex steroids, before and during 7 days of sc LHRH administration (136-150 ng/kg bw every 120 min) in 5 uremic children (13.1-14.8 yr) with delayed puberty. Six nonuremic children (13.2-17.8 yr) with delayed puberty underwent the same schedule and served as control group. On day 0 mean immunoreactive LH (I-LH) levels were higher in uremic (4.5 +/- 0.9 mIU/ml) than in nonuremic (1.9 +/- 03 mIU/ml; p < 0.05) subjects while no differences were observed in bioactive LH (B-LH) levels (2.9 +/- 0.7 mIU/ml vs 2.4 +/- 0.3 mIU/ml). In both groups of subjects testosterone was at prepubertal levels. Spontaneous I-LH and B-LH pulses were observed sporadically in both uremic and nonuremic subjects. Short-term pulsatile LHRH administration induced significant increases in B-LH, I-LH, FSH and testosterone. The B/I LH ratio increased from day 0 (0.7 +/- 0.2) to day 7 (1.3 +/- 0.4; p < 0.05) in uremics while it showed wide fluctuations in nonuremic subjects. On day 7, 4 uremic and 5 nonuremic subjects showed a pulsatile release of B-LH after exogenous LHRH pulses. Our data document that in uremia there are qualitative as well as quantitative abnormalities in pituitary gonadal secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Nutritional status and muscle amino acids in children with end-stage renal failure.

Nutritional status, assessed by anthropometric and biochemical methods, and muscle water, protein and amino acid composition, were evaluated in a control group of 10 children with normal renal function who were undergoing elective surgery, and in 15 children with end-stage chronic renal failure. Samples of the rectus abdominis muscle were taken when surgery was performed in the control children and when a peritoneal catheter was implanted in the uremic children. Height and body weight were reduced in the uremic children compared to the controls but skinfold thickness, arm muscle circumference and serum proteins (total protein, albumin, transferrin, pseudocholinesterase) were essentially normal. The muscle contents of total, extracellular and intracellular water, and of alkali-soluble protein (ASP), DNA and the ASP-DNA ratio were not significantly different in uremic children from those in the controls. Plasma leucine, isoleucine, tyrosine, valine, and serine levels were significantly decreased, whereas plasma citrulline, 1-methylhistidine and 3-methylhistidine levels were increased. Muscle isoleucine and valine levels and the valine/glycine ratio were low in the uremic children. Our results demonstrate that children with chronic renal failure and growth retardation may maintain a satisfactory nutritional status but exhibit amino acid abnormalities typical of uremia.

Adolescent↗