Biomedical subjects

F Perfumo

Publications and source records attributed to F Perfumo.

18 recordsLinked to original sources

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↗

PubMed1992

Modulation of proteinuria and renal xanthine oxidase activity by dietary proteins in acute adriamycin nephrosis in rats: lack of correlation with intra- and extracellular amino acids.

Protein restriction ameliorates proteinuria in acute adriamycin (ADR) nephrosis and decreases the renal levels of xanthine oxidase (XO), a putative mediator of ADR nephrotoxicity. Hypothetically, the effect of protein restriction on renal XO levels may be due to variations in plasma and tissue proteic amino acids (AA). To elucidate this point, the levels of AA in plasma and in renal homogenates were determined in rats with ADR nephrosis and fed diets with different protein contents: (a) high (35%) casein; (b) standard (21%) casein; (c) low (9%) casein; (d) low casein plus a synthetic mixture of Val, Leu and Ile. The protein content of the diet determined certain marked variations in plasma AA: high levels of Val, Leu and Ile were found in rats fed on a high protein diet, while the same AA were low, in rats on low protein regimen. Supplementation of the low protein diet with a synthetic mixture of branched-chain AA (Val, Leu and Ile) normalized the plasma levels of these AA. In spite of these changes, tissue AA were similar in all groups, regardless of the protein contents of the diets. Furthermore, the levels of renal XO and proteinuria were unrelated to variations in plasma AA, since both parameters were low in protein-restricted and protein-restricted AA-supplemented rats while high in rats fed a high or normoproteic diet. These data demonstrate that low protein diets induce marked alterations in plasma AA composition which are similar in may respects to those found in protein malnutrition.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1992

Five years' experience of the Italian Registry of Pediatric Chronic Peritoneal Dialysis.

The results of the first 5 years' experience of the Italian Registry of Pediatric Chronic Peritoneal Dialysis (CPD) (1986-1990) are presented. Patients of less than 15 years of age at start of dialysis were enrolled and clinical data collected until the age of 19. The number of the dialysis centres participating in the Registry increased from 7 in 1986 to 15 in 1990. The total number of patients on CPD was 119, the number of new patients per year ranged from 15 to 28 and the percentage of all dialysed children treated with CPD increased from 40% in 1986 to 49% in 1990. The age of patients at start of CPD was 8.5 +/- 4.9 years and 16% of them were under 2 years. Only CAPD was utilized in 1986, while CCPD/NPD accounted for 53% and 65% of the treated patients in 1989 and 1990, respectively. At 4 years, patient survival was 91.3% and technique survival 79.3%. A comparison between data of 48 patients on CPD and 34 on hemodialysis, who started dialysis in the period 1989-1990, showed that CPD was the most frequent form of initial therapy (56%) and was the treatment of choice for children younger than 4 years.

Age Factors↗

PubMed1992

Peritonitis in children undergoing chronic peritoneal dialysis (CPD): data from the Italian Registry of Pediatric CPD.

During the period 1986-1990, 119 patients were enrolled in the Italian Registry of Pediatric CPD. CAPD was largely predominant in the first 3 years, while CCPD accounted for 48% of dialysis months in the period 1989-1990. The connect-disconnect system was a Y set for all patients during the whole observation period. The incidence of peritonitis decreased from 1 episode: 10.9 patient-months in 1986 to 1:19.8 in 1988, and then passed to 1:16.2 in 1990. A comparison of the incidence of peritonitis between CAPD and CCPD, referring to the 1989-1990 period, showed no significant difference. The percentage of positive peritoneal fluid cultures changed from 48% in 1986 to 73% in 1990. Gram-positive bacteria, primarily Staphylococcus aureus and Staphylococcus epidermidis, accounted for most of the isolated organisms. Candida albicans was cultured in 3 cases both in 1986 and 1987. Exit site infection was the predominant (82%) complication, followed by leakage and catheter cuff extrusion. The hospitalization rate for peritonitis resulted persistently high (61% of episodes) and the mean duration was 12.7 days. Of the 8 patients who were switched to hemodialysis, 4 had recurrent peritonitis and 1 Candida albicans peritonitis.

Adolescent↗

PubMed1991

Biological activity of luteinizing hormone in uraemic children: spontaneous nocturnal secretion and changes after administration of exogenous pulsatile luteinizing hormone-releasing hormone--preliminary observations.

Normal pubertal progression is associated with quantitative and qualitative changes in gonadotrophin release. Uraemic children show a delayed or disturbed puberty. We have therefore examined nocturnal gonadotrophin and sex steroid secretion in seven males and three females [age 11-15 years, pubertal stage (PS) 1-3] with chronic renal failure on conservative treatment. In addition to immunoreactive luteinizing hormone (i-LH) we have measured the biological activity of LH (b-LH). Nine children aged 12-17 years with PS 1-3 and normal renal function served as a control group. In two uraemic children, i-LH, b-LH, follicle stimulating hormone and sex steroids were evaluated before and 7 days after pulsatile LH-releasing hormone (LHRH) administration (150 ng/kg body weight subcutaneously every 120 min). Mean i-LH levels were higher in uraemic children than in controls. An increase in i-LH during sleep was found in all controls and in eight of ten uraemic subjects. Mean b-LH levels were lower during sleep and the b/i LH ratio was reduced in uraemic children with PS 2-3 whether asleep or awake compared with controls. Pulsatile administration of LHRH provoked a rise of i-LH and b-LH levels with an increased b/i LH ratio, suggesting an intact pituitary responsiveness. These preliminary data indicate that the gonadotrophin control of LH is abnormal in uraemic children, and that biopotency of LH secretion might be improved after short-term pulsatile LHRH administration.

Adolescent↗

PubMed1991

Autoreactive lymphocytotoxic IgM antibodies in highly sensitized dialysis patients waiting for a kidney transplant: identification and clinical relevance.

The contribution of different families of lymphocytotoxic antibodies in the serologic reactivity of 45 highly sensitized dialysis patients (HSDP) (panel reactivity antibody value-PRA greater than 80%) was assessed by analyzing patients' sera for the presence of auto- and alloreactive IgM and alloreactive IgG antibodies. A total of 220 sera was screened at different incubation temperatures, before and after treatment with the reducing agent dithiothreitol, against a large variety of cell targets by means of complement dependent cytotoxicity (CDC) and antiglobulin augmented (AHG) CDC assays. The results allowed to subdivide the HSDP under study into four groups: Group 1 consisted of 13 untransplanted patients and 14 patients with a prior failed graft whose PRA values did not change following DTT treatment. Alloreactive IgG antibodies alone, with anti-HLA specificity, were present in the sera of this patient group. Group 2 consisted of 3 untransplanted patients whose sera did not contain any autolymphocytotoxic antibody but appeared completely unreactive to panel lymphocytes following DTT treatment, thus confirming the presence of alloreactive IgM only endowed with antiHLA reactivity. Group 3 consisted of 4 untransplanted and 4 patients with a prior failed graft whose sera were found to contain in addition to autoreactive IgM also alloreactive IgG antibodies. Their PRA values declined after DTT treatment on average from 96.2% to 45% and from 95% to 52.5%, respectively. Group 4 consisted of 6 untransplanted patients whose PRA reactivity to both autologous and panel lymphocytes completely disappeared following DTT treatment, thus indicating that their sera contained exclusively autolymphocytotoxic IgM antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1979

[The hyperaminoacidurias with special reference to cystinuria].

Increased urinary excretion of free amino acids is a sign which requires determination of the underlying cause. Physiological aspects of tubular transport with emphasis on the role played by transport proteins or carriers are briefly discussed. Subsequently we present a resumptive classification. In prerenal hyperaminoaciduria the urinary excretion of amino acids just reflects the error in amino acid metabolism. Depending on tubular reabsorption of the amino acid involved in the metabolic error three types can be distinguished: the overflow, the competitive and the non-threshold hyperaminoacidurias. Renal hyperaminoaciduria can either be specific for individual or group-related amino acids, or generalized involving all amino acids. With the exception of classical cystinuria the various hyperaminoacidurias have more theoretical than clinical importance. Generalized hyperaminoaciduria is always a symptom of severe tubular disturbance which can be produced by various metabolic diseases, intoxications or deficiency states. Finally we present our experience in the treatment of cystinuria with mercaptopropionyl-glycine.

Amino Acids↗

PubMed1979