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Biomedical subjects

G Rizzoni

Publications and source records attributed to G Rizzoni.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cyclosporine A monitoring in children: abbreviated area under curve formulas and C2 level.

Cyclosporine A (CsA) is the most commonly used drug in organ transplantation. To evaluate exposure the gold standard is area under curve (AUC), but this is expensive and requires many blood samples. For this reason, abbreviated formulae have been developed in adults. Data in children are scanty. Formulae cannot be applied in patients taking CsA every 8 h. We tested the abbreviated AUC formula published for adults in renal transplant children on twice daily therapy and we propose a method, requiring three blood samples, for those taking CsA every 8 h. A very good correlation was obtained for both groups. Furthermore, we studied the correlation between CsA concentration 2 h after administration and AUC. A good correlation was found supporting the possible use of this parameter for monitoring CsA therapy.

Adolescent↗
PubMed1999

Delayed onset of systemic lupus erythematosus in patients with "full-house" nephropathy.

Three patients are described who presented with a glomerulopathy suggestive of lupus nephritis in the absence of other clinical and biological evidence of systemic lupus erythematosus (SLE). Renal biopsies showed a "full-house" immunofluorescence pattern and two patients also had cytoplasmic tubuloreticular inclusions by electron microscopy. All these patients developed antinuclear and anti-double-stranded DNA antibodies 3, 5, and 10 years after their original presentation. Subsequently, 1 patient also developed clinical symptoms of lupus. Reviewing all renal biopsies performed in our department, we found 14 additional patients who presented with a "full-house" immunofluorescence glomerulonephritis in the absence of other features of SLE. After a mean follow-up of 5.8 years, these patients have not developed serological or clinical evidence of SLE. We conclude that a "full-house" glomerulopathy in children may be the first symptom of SLE, especially when cytoplasmic tubuloreticular inclusions are detected. The appearance of other clinical and biological symptoms may be delayed by several years.

Adolescent↗
PubMed1999

Purpura of the ears: a distinctive vasculopathy with circulating autoantibodies complicating long-term treatment with levamisole in children.

The cutaneous side-effects of levamisole include non-specific and lichenoid eruptions, fixed drug eruption and, very rarely, cutaneous vasculitis. We describe a distinctive clinical and histological vasculopathy with immunological abnormalities in children with paediatric nephrotic syndrome receiving long-term levamisole treatment. Four boys and one girl were identified. Their average age was 10 years. Levamisole had been used for an average of 24 months. Purpura of the ears was the most common finding corresponding histologically to a vasculopathic reaction pattern ranging from a leucocytoclastic and thrombotic vasculitis to a vascular occlusive disease without true vasculitis but with associated antinuclear, antiphospholipid and anticytoplasmic antibodies. The eruption resolved in all patients 2-3 weeks after the discontinuation of levamisole, but serum autoantibodies persisted for 2-14 months.

Adjuvants, Immunologic↗
PubMed1999

Left ventricular hypertrophy, treadmill tests, and 24-hour blood pressure in pediatric transplant patients.

BACKGROUND: Hypertension and left ventricular hypertrophy (LVH) are possible complications in pediatric patients after renal transplantation. METHODS: We performed left ventricular echocardiography, 24-hour ambulatory blood pressure monitoring (24-hr ABPM), and treadmill tests in 28 pediatric renal transplant patients (mean age 16.1 +/- 3.7; time since transplantation 36 +/- 23 months). Left ventricular mass (LVM) was indexed for height 2.7. RESULTS: LVH was found in 82% of the patients. Seven of these patients were normotensive by 24-hour ABPM, but five patients showed a hypertensive systolic BP response during the treadmill test. LVM/height 2.7 correlated significantly with the mean 24-hour systolic BP (P = 0.002) and with the maximal exercise systolic BP (P = 0.002). CONCLUSION: LVH is frequent in pediatric renal transplant patients. More information is needed with respect to the risk for LVH, including data from 24-hour ABPM and treadmill testing.

Adolescent↗
PubMed1998

A ten-year experience of Brescia-Cimino arteriovenous fistula in children: technical evolution and refinements.

PURPOSE: The arteriovenous fistula (AVF) of Brescia-Cimino fulfills nearly all of the criteria for an optimal access for chronic hemodialysis, such as long-term patency rate, low complication rate, and respect of vascular morphologic features. Alternative dialytic methods (i.e., external shunts and vascular grafts) cannot easily be applied to pediatric patients, and in addition, these methods are responsible for higher complication rates. METHODS: From January 1985 to December 1994, 112 Brescia-Cimino AVFs were performed in 90 children (average age, 5.5 years; range, 5 months to 18 years). The average weight of the children was 28 kg (range, 6.5 to 54 kg); 16% of AVFs were performed in children who were less than 5 years old, and 18% in children who were less than 15 kg in body weight. RESULTS: Chronic renal failure was caused by a nephropathy in 53 cases (14 with a nephrotic syndrome), and 37 cases had a uropathy. In all cases a phlebography was performed before the microsurgical treatment. Since 1994 an inflatable tourniquet has been placed on the selected upper arm because of an optimal exsanguination of the operating field. The primary patency rate was obtained in all but six of the children; 35% of AVFs had either immediate or late complications. Thrombosis was the most frequent complication that we observed. In comparison with 79% of late thrombosis, 60% of early thrombosis was cured. Of the 80 AVFs, 63.5% with a 4-year follow-up are still patent. CONCLUSION: We emphasize the following two conclusions: first, microsurgery is essential to create AVFs with good results in children as well as in adult patients; and second, the results improved after the adoption of an upper-arm exsanguination and ischemia (pressure range, 400 mm Hg to 600 mm Hg) that avoided spasm of the vessels with a final 35% reduction in surgical time.

Adolescent↗
PubMed1998

Hypertension in young patients after renal transplantation: ambulatory blood pressure monitoring versus casual blood pressure.

The results of ambulatory blood pressure monitoring (ABPM) in children after kidney transplant were analyzed to ascertain any alteration in circadian BP profile, degree of hypertension, and efficacy of therapy. The data were also compared with casual BP data and left ventricular mass index (LVMI). We have examined 30 patients (17 male, 13 female), mean age 16.1+/-3.6 years after kidney transplant. All patients were receiving triple immune-suppressive therapy and 20 of them were also taking antihypertensive therapy. They underwent clinical examination with measurement of BP at rest, echocardiogram mono-2D, and ABPM. The following ABPM parameters were recorded: systolic (S) and diastolic (D) BP at rest; mean 24-h SBP and DBP; mean daytime SBP and DBP; mean nighttime SBP and DBP; nocturnal fall in SBP and DBP; and mean daytime and nighttime heart rate (HR). The patients were divided in two groups. Group A consisted of 20 patients taking antihypertensive treatment; group B consisted of 10 patients not taking antihypertensive treatment. Casual and ABPM data for the two groups were compared using the Student t test for unpaired data. Blood pressure at rest and LVMI were not statistically different between the two patient groups. The ABPM data showed statistical differences between the two groups for mean 24-h SBP and DBP, daytime and nighttime SBP, nighttime DBP, fall in nocturnal DBP, and nighttime HR. Mean 24-h SBP and DBP, mean daytime SBP and DBP, and mean nighttime SBP and DBP were significantly correlated to LVMI (respectively, P = .009, P = .005, P = .008, P = .007, P = .05, and P = .01). Twenty-four-hour ABPM was more useful in the diagnosis and management of hypertension than was casual BP at rest.

Adolescent↗
PubMed1997

Combined heart and kidney transplantation in a child: will we need it more in the future?

A 12-year-old girl affected by idiopathic dilated cardiomyopathy and renal failure was referred to our institution for cardiac transplantation. A simultaneous heart-kidney transplantation from the same donor was decided. The immunosuppression schedule consisted of azathioprine, antithymocyte globulin, steroids, and cyclosporine. At a follow-up visit at 24 months after transplantation, no episodes of heart or kidney rejection had occurred and cardiac and renal function were good. Concomitant failure of heart and kidney is well known in the literature, but it appears to be more frequent in adult as compared with the pediatric population. This is the first case of combined heart and kidney transplantation in a child. Because of the successful outcome and good follow-up, the number of combined organ transplantations will most likely increase in the future.

Cardiomyopathy, Dilated↗
PubMed1997

Ultrastructural immunocytochemistry of collagenous and non-collagenous proteins in fast-frozen, freeze-substituted, and low-temperature-embedded renal tissue in Alport syndrome.

This paper describes the ultrastructural immunolocalization of the alpha 2 chain of collagen IV, laminin, and the amino terminal propeptide of collagen I (N-Pro I) in glomeruli of rapidly frozen, freeze-substituted, and low-temperature-embedded renal biopsy specimens from two cases of Alport disease and from normal kidneys. The alpha 2 chain of collagen IV is present in the whole thickness of the basement membrane in glomeruli of Alport patients, while it is limited to the subendothelial portion of the basement membrane of normal glomeruli. Laminin has the same distribution in both normal and Alport glomeruli, but is apparently more concentrated along the basement membrane of normal glomeruli. N-Pro I is localized in mesangial areas and in the basement membrane in Alport cases, while it is not detected in normal glomeruli. These data suggest complex rearrangements of major constituents of the glomerular basement membrane network and demonstrate early deposition of fibrillary collagen proteins in the matrix before the appearance of banded collagen fibres. This finding could be an indicator of early evolution towards glomerulosclerosis.

Basement Membrane↗
PubMed1997

Feeding dysfunction in infants with severe chronic renal failure after long-term nasogastric tube feeding.

Nasogastric tube feeding (NGTF) is frequently necessary to overcome the inadequate caloric intake of children with severe chronic renal failure (CRF). In a multicenter retrospective study, we evaluated feeding dysfunction after tube feeding withdrawal in children with severe CRF who started long-term enteral nutrition early in childhood. We considered, almost exclusively, infants who had started NGTF very early and continued to be tube fed for at least 9 months. Twelve patients were included in the study: 8 showed significant and persistent eating difficulties, with difficulties in chewing and swallowing in 7 and food refusal in 6. For 2 patients "panic attacks" from swallowing were repeatedly reported. These problems persisted for more than year in 5 patients and between 1 and 6 months in 4. The possible feeding difficulties that may follow NTGF must be carefully evaluated. A possible means of overcoming these difficulties might include: encouraging the use of a pacifier, proposing water for spontaneous assumption, leaving the child the possibility of eating food spontaneously during the daytime, and increased support for the parents during weaning. These need prospective study.

Child, Preschool↗
PubMed1997

Exercise tolerance and behavior of blood pressure in children and adolescents after renal transplant.

OBJECTIVE: The purpose of the study was to evaluate the exercise tolerance and the behaviour of blood pressure during a maximal exercise testing on treadmill for a group of patients with renal transplant carried out at least 6 months earlier. EXPERIMENTAL DESIGN, SETTING AND PATIENTS: In a retrospective study, nineteen patients were examined in our laboratory: 13 boys and 6 girls, mean age 15.8 years (range 10.5-22). INTERVENTIONS: All patients were given a clinical examination, an ECG at rest, a maximal exercise testing on treadmill (Bruce protocol), a mono-2D echo, a lung function test and 24-hour Holter monitoring. The results of the exercise test were compared with those of two control groups of same age and body surface area. RESULTS: The clinical examination of their cardiovascular apparatus gave normal results. The echo revealed anatomical and heart function anomalies related to the original disease. Exercise testing on treadmill showed a reduction in exercise tolerance (p < 0.001) and the maximal heart rate showed a statistically significant difference (p < 0.001) in comparison to control groups. Maximal systolic blood pressure was higher than in patients with same body surface area (p < 0.001) and higher than in peers (p = 0.133). CONCLUSIONS: In view of this hypertensive response, strenuous physical activity should be undertaken with caution and indeed submaximal aerobic activity is more suitable for this population of patients.

Adolescent↗
PubMed1996

Prenatal ultrasonographic findings of dominant polycystic kidney disease and postnatal renal evolution.

Autosomal dominant polycystic kidney disease (ADPKD) is a relatively common genetic disorder, and its prenatal diagnosis has been reported with increasing frequency. Nevertheless, no data are available on the significance of prenatal ultrasound (US) patterns in predicting postnatal renal function and outcome. We report on one case of ADPKD diagnosed prenatally by US, and on two cases diagnosed immediately after birth, with different prenatal US and renal outcomes. Data on prenatal US findings and postnatal renal evolution are scanty and largely incomplete. Apparently, none of the prenatal findings are consistently different in cases with and without normal postnatal renal function and blood pressure. More complete information on prenatal US findings and postnatal renal evolution is urgently needed.

Female↗
PubMed1996

Sensorineural hearing loss in patients reaching chronic renal failure in childhood.

The incidence of sensorineural hearing loss (SNHL) was investigated in 68 patients who reached chronic renal failure (CRF) in childhood with the aim of identifying possible risk factors. Tests were carried out by means of pure-tone and impedance audiometry. SNHL was found in 29% of patients on conservative treatment, 28% of patients on hemodialysis, and 47% after renal transplantation. Differences among groups were not significant. A significant correlation was found with the administration of ototoxic drugs (aminoglycosides and furosemide). We hypothesize that SNHL may be reduced in patients with CRF or on renal replacement therapy by strictly monitoring ototoxic therapy.

Acoustic Impedance Tests↗