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Biomedical subjects

F Perfumo

Publications and source records attributed to F Perfumo.

At least 73 records · Page 4Linked to original sources

Pharmacokinetics and hematologic response to subcutaneous administration of recombinant human erythropoietin in children undergoing long-term peritoneal dialysis: a multicenter study.

For a study of the pharmacokinetics and hematologic response of subcutaneously administered recombinant human erythropoietin (rHuEPO), 24 children (mean age, 10 years 3 months; range, 3 months to 18 years) maintained by peritoneal dialysis and with anemia caused by end-stage renal failure (mean hemoglobin level, 6.5 gm/dl; range, 4.7 to 7.9) were treated with rHuEPO administered subcutaneously at an initial dose of 25 IU/kg twice per week. After a 4-week interval, in the case of no response (hemoglobin increase < or = 1 to 1.5 gm/dl per month) the rHuEPO dosage was increased every 4 weeks according to the following schedule: 50, 75, 100, and 150 IU/kg twice per week. The administration of rHuEPO produced a rapid increase in serum concentration with a mean peak level of 59.8 mU/ml after 9 hours. Mean area under the curve to 72 hours was 2020 mU/ml per hour (range, 568 to 6609); mean elimination half-life and mean residence time were, respectively, 25.2 hours (range, 6.2 to 58.7) and 42.0 hours (range, 10.9 to 96). Of 24 children entered in the study, six had the drug suspended early because of renal transplantation (n = 1), lack of compliance (n = 4), or severe worsening of hypertension (n = 1). Eighteen patients had increased hemoglobin levels (to 9.4 +/- 1.7 gm/dl after 24 weeks of treatment). No correlation was found between the increase in hemoglobin concentration and any of the pharmacokinetic data or the peak erythropoietin level reached during the kinetic profile. Eight children required an increase of antihypertensive medications to maintain satisfactory blood pressure values. We conclude that low doses of subcutaneously administered rHuEPO slowly release the drug into the blood and satisfactorily increase hemoglobin levels with very few side effects.

Adolescent↗

Progression of chronic adriamycin nephropathy in leukopenic rats.

In this study, we examined the progression of chronic Adriamycin (ADR) nephropathy in mild leukopenic rats and tried to define the possible relationship between tubulointerstitial lesions and proteinuria in this model. Chronic ADR nephropathy was induced by 2 doses of ADR (2 mg/kg) in 32 Sprague-Dawley rats. Eight of these were randomly assigned to cyclophosphamide treatment (50 mg/kg), given intravenously every week, to keep the blood leukocyte count constantly lower than 5,000/mm3. Serial parameters were followed for 16 weeks including clearance studies with iothalamate and p-aminohippurate and the analysis of urinary protein composition by: (a) an enzymatic assay for beta-glucosidase; (b) specific ELISA using antibodies against rat albumin and RBP, and finally (c) two-dimensional electrophoresis. ADR-treated rats rapidly (within 2 weeks) developed massive proteinuria which was in constant increment throughout the disease evolution in each single component (i.e., high and low molecular weight proteinuria, enzymuria) and developed renal insufficiency. At week 8, in ADR rats, glomerulosclerosis was mild whereas tubulointerstitial infiltrates predominated, characterized mainly by CD4+ T lymphocytes while CD8+ T lymphocytes were inconspicuous, and macrophages were only occasionally present. All such alterations had worsened after 16 weeks when the tubulointerstitial infiltration was associated with marked interstitial fibrosis and tubular atrophy. Leukopenia induced by cyclophosphamide was in all cases associated with a net amelioration of renal histopathology reducing tubulointerstitial infiltrates (by 40%) and glomerulosclerosis (33 +/- 5 vs. 52.2 +/- 7.5% sclerotic glomeruli) and also ameliorated glomerular filtration indexes (Cl 780 +/- 40 vs. 447 +/- 66 microliters/min/kg-1). In spite of these differences, albuminuria and urinary-retinol-binding protein were comparable at weeks 4, 8 and 16 in this group, while urinary beta-glucosidase was decreased at week 16 (p < 0.001) in cyclophosphamide-treated rats. No other qualitative changes in urinary proteins were detectable by 2-dimensional electrophoresis during the disease development. We concluded that chronic leukopenia prevents interstitial cellular infiltration by lymphocytes, interstitial fibrosis and slows down the decline of renal function typical of chronic ADR nephropathy. Glomerulosclerosis is also reduced in leukopenic rats without any appreciable changes in the urinary excretion of high molecular weight proteins deriving from the glomerulus. Finally, the improvement in tubulointerstitial alteration is associated with the reduction in urinary lysosomal enzymes. Tubulointerstitial alterations are implicated with a prominent role in the progression towards renal failure in chronic ADR glomerulopathy.

Animals↗

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↗

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↗

Chronic peritoneal dialysis catheters in pediatric patients: experience of the Italian Registry of Pediatric Chronic Peritoneal Dialysis.

During the period 1986-1991, 140 pediatric patients [age < or = 15 years at the start of chronic peritoneal dialysis (CPD)], belonging to 15 dialysis centers, were enrolled in the Italian Registry of Pediatric Chronic Peritoneal Dialysis. Data on 188 peritoneal catheters were collected: 161 catheters were Tenckhoff (144 double-cuff, 17 single-cuff), and 27 were two-cuff Valli-type catheters. All catheters were surgically inserted; the entry site was in the midline in 84 cases and paramedian in 104. An omentectomy was performed in 78.8% of the cases. Apart from peritonitis, there were 161 catheter-related complications (103 exit-site infections, 17 leakages, 15 obstructions, 15 outer-cuff extrusions, 5 hemoperitoneum, 6 others) observed during 2687.5 dialysis-months, with an incidence of one complication every 16.7 dialysis-months. Fifty-five catheters (29.2%) were removed; infection (39 cases) was the main cause for removal, followed by obstruction (9 cases), dislocation, and outer-cuff extrusion (2 cases each). Actuarial survival of all catheters was 79.7% at 1 year, 66.6% at 2 years, 42.8% at 3 years, and 39.8% at 4 years. No difference in catheter survival was observed according to the entry site. When considering the age of the patients at catheter insertion, a difference close to statistical significance was found (p = 0.06).

Actuarial Analysis↗

Analysis of complications in a chronic peritoneal dialysis pediatric patient population. The Italian Registry of Pediatric Chronic Peritoneal Dialysis.

During the period 1986-1991, the Italian Registry of Pediatric Chronic Peritoneal Dialysis collected data from 140 patients younger than 15 years at the start of chronic peritoneal dialysis (CPD). In this study we review the Registry's complications and patient hospitalization data. A total of 395 complications directly related to CPD were registered during 2722 dialysis-months. There were 176 episodes of peritonitis (44.5%), 161 catheter-related complications (40.7%) (103 exit-site infections, 17 leakages, 15 obstructions, 15 cuff extrusions, 5 hemoperitoneum, and 6 other complications), and 58 technique-related complications (14.8%) (39 abdominal hernias, 10 hydroceles, 5 with abdominal pain, 4 hydrothorax complications). The patient hospitalization rate during the period 1989-1991 was evaluated; the analysis referred to 106 patients who underwent treatment for a total of 1520.5 dialysis-months. Patients starting CPD in the year and patients already on CAPD spent 5.8 and 2.1 days per patient-month in the hospital, respectively; the difference was not statistically significant. The evaluation of complications (both technical and systemic) causing patient hospitalization showed that peritonitis was responsible for 43.2% of patient admissions and 36.3% of days hospitalized, catheter-related complications for 22% and 19.8%, technique-related complications for 8.3% and 5.1%, and other clinical complications for 26.5% and 38.8%, respectively.

Catheters, Indwelling↗

Cardiovascular function in a chronic peritoneal dialysis pediatric population on recombinant human erythropoietin treatment.

Anemia, through a hyperkinetic state, is an important contributor to myocardial function impairment. To determine the cardiovascular effects of recombinant human erythropoietin (rHuEPO) therapy, 10 chronic peritoneal dialysis (CPD)-treated anemic children were studied before and during 18 months of treatment. The following parameters were recorded: hemoglobin (Hb) [percent of target level (TL) = x-2 standard deviations of normal Hb values for age and sex], heart rate (HR, beats/minute), mean arterial pressure (MAP, mmHg), end-diastolic left ventricular diameter (EDLVD, mm/sm BSA), shortening fraction (SF, percent), and interventricular septal thickness (IVS, mm/sm BSA). Student's t-test for paired data showed (vs time before treatment, T0) a progressive increase in Hb, a progressive decrease in HR, and a progressive increase in MAP. EDLVD progressively decreased, while SF and IVS remained unchanged throughout the study. Regression analysis showed a close correlation between anemia correction and decrease of HR (p < 0.01), while no correlation was found between Hb and EDLVD or SF, IVS, or MAP. Our data indicate that anemia correction in these patients is mainly associated with a decrease in hyperkinetic state (HR reduction with SF unvaried), while left ventricular function and dimensions remain normal, despite an increase in MAP.

Anemia↗

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↗

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↗

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↗

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↗

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↗

Long-term effect of amino-acid dialysis solution in children on continuous ambulatory peritoneal dialysis.

The study involved eight metabolically stable children, with chronic renal failure on continuous ambulatory peritoneal dialysis (CAPD) whom we followed for 12-18 months. For the first 6 months CAPD was performed with dextrose; for the subsequent 6-12 months the morning exchange was substituted with a 1% amino-acid (AA) solution. The following parameters did not change during the study: serum creatinine, uric acid, inorganic phosphate, serum bicarbonate, potassium, cholesterol, triglycerides, total protein, albumin and transferrin. The only parameter that changed was blood urea nitrogen, which increased moderately. The anthropometric parameters did not show significant variation before and after AA dialysis. The plasma AA profile, which under basal conditions showed lower levels of several essential AAs, improved during the treatment period, with a partial correction of the imbalance. It is possible that this correction of plasma AAs may positively influence the metabolism of some organs such as the brain, muscle and those of the hepatosplanchnic region. The intracellular pool of free AAs, measured in polymorphonuclear leucocytes, was severely altered before the treatment and after 6 and 12 months showed only minor variations. It is possible that some modifications in the proportion of the different AAs in the dialysis solution or an improvement in the concentration or in the number of exchanges per day are necessary in order to change the nutritional status and to modify the intracellular AA pool.

Amino Acids↗

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↗

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↗