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Biomedical subjects

G Zacchello

Publications and source records attributed to G Zacchello.

At least 19 recordsLinked to original sources

Infantile encephalomyopathy and nephropathy with CoQ10 deficiency: a CoQ10-responsive condition.

Coenzyme Q10 (CoQ10) deficiency has been associated with various clinical phenotypes, including an infantile multisystem disorder. The authors report a 33-month-old boy who presented with corticosteroid-resistant nephrotic syndrome in whom progressive encephalomyopathy later developed. CoQ10 was decreased both in muscle and in fibroblasts. Oral CoQ10 improved the neurologic picture but not the renal dysfunction.

Atrophy↗

Mycophenolate mofetil pharmacokinetic monitoring in pediatric kidney transplant recipients.

This open-label, longitudinal, long-term study of de novo pediatric renal transplant recipients was designed to investigate the pharmacokinetics (PK) of mycophenolic acid (MPA) and its possible interaction with cyclosporine (CsA). Thirty-four children on an immunosuppressive regimen of CsA, prednisone, and mycophenolate mofetil (MMF, 300-400 mg/m2 twice daily) were investigated at 6, 30, 180, and 360 days after transplantation. Considerable interindividual variability in the areas under the concentration curve (AUC(0-12)) of MPA was observed during the follow-up, although the dose of MMF remained the same over the same time. Predose levels (C0) increased significantly during the first 6 months after transplantation: C0 at 6 and 180 days after transplantation was 0.8 +/- 0.6 and 1.9 +/- 1.1 microg/mL (P < .0001). A significant time-dependent increase in the AUC of MPA was also observed during the first 6 posttransplant months: AUC(0-12) at 6 and 180 days after transplantation was 23.3 +/- 10.8 and 40 +/- 11.6 mg*h/L (P = .003). MPA concentrations 3 and 4 hours after MMF intake were the individual time points that best correlated with the full MPA AUC (r = 0.8 and 0.79; P < .001). The abbreviated MPA AUC (0-4 hours) correlated reasonably with the full AUC (r = 0.87; P < .001). Finally, a significant reduction in CsA dose during the first 6 posttransplant months (P < .001) matched the significant increases in both MPA C0 and full MPA AUC, thus demonstrating the interaction of the 2 immunosuppressive drugs. These observations suggest the need for therapeutic drug monitoring when adjusting the dose of MMF in children.

Child↗

Kidney transplantation in children with reconstructed bladder.

There is some controversy about the safety of renal transplantation in patients with an augmentation cystoplasty because of the possibility of urinary tract infection in immunosuppressed patients leading to pyelonephritis and graft loss. Nevertheless, it is now well known that in patients with a small volume and poorly compliant bladder, reconstructive bladder surgery (augmentation cystoplasty or continent reservoir) creates a low-pressure and compliant reservoir, which protects the upper urinary tract and restores a functional lower urinary tract. Graft survival is not adversely affected when a kidney transplant is drained into a reconstructed bladder. When bowel segments are used for augmentation, a voiding modality with clean intermittent self-catheterization does not increase the risk of urinary tract infections, even in immunosuppressed patients.

Child↗

Retrospective study of children with acute pyelonephritis. Evaluation of bacterial etiology, antimicrobial susceptibility, drug management and imaging studies.

The purpose of the study was to investigate the management of pyelonephritis in a large Italian pediatric population. A total of 1,333 patients (36% male) were considered. Escherichia coli was the most frequently isolated agent (89.9%), followed by Proteus mirabilis (3.6%) and Klebsiella oxytoca (2.1%). 27% of microorganisms were resistant to amoxicillin, 4% to amoxicillin/clavulanic acid, 11% to trimethoprim-sulfamethoxazole, 2.4% to gentamicin and less than 2% to ceftazidime. Despite this resistance pattern showing that oral antibiotics, such as amoxicillin/clavulanic acid, are effective in vitro as well as parenteral antimicrobials, a parenteral antibiotic was given initially to 756 (57.2%) children. A prophylactic regimen was started in 922 patients with a rate of reinfection during prophylaxis of 9.5%; a higher rate of reinfection was observed in patients with reflux (25%) compared to children without reflux (3%) (p < 0.0001). Vesicoureteral reflux was demonstrated in 30% of patients. The number of renal abnormalities detected by DMSA in patients with and without reflux was significantly different (p < 0.001). CRP was higher in patients with scars (p < 0.02). In conclusion, pyelonephritis represents a common disease with about 2,500 days of hospitalization per year in the Veneto Region where there is a pediatric population of about 800,000 under 15 years of age. The results of antimicrobial in vitro tests indicate that amoxillicin/clavulanic acid could represent the antibiotic of choice. The high frequency of malformations, observed even in children between 6 and 12 years of age, may suggest the need of an imaging study including DMSA scan and VCUG in all age groups.

Acute Disease↗

Successful renal transplantation in children under 6 years of age.

To evaluate the efficacy of renal transplantation in small pediatric patients, we have reviewed 41 allografts performed in 39 children (28 M/11 F) less than 6 years of age between 1987 and 1998 in the North Italy Transplant Program. Of these patients, 39 had a cadaver donor and 2 a living-related donor, with ages ranging from 20 days to 35 years. The mean follow-up was 56 months. Graft survival was 74.5% and 70.5% at 1 and 5 years, respectively. The causes of graft lost were acute rejection (4), graft vascular thrombosis (4), and hemolytic uremic syndrome recurrence (1). Only 1 patient has died due to chickenpox. Double and triple immunosuppressive therapies were used in 63% and 37% of patients, respectively, on the basis of different center protocols, without differences in graft survival. Steroids were successfully administered on alternate days in 37% of patients, 6-12 months after transplantation. Thrombosis was reported in 2 of 6 kidneys from donors less than 1 year of age and in 2 of 35 donors older than 1 year (P < 0.05). Thirty rejections occurred in 23 patients: 7 episodes were steroid resistant and were treated with ATG/OKT3. Thirty-four infections were reported in 16 of 41 patients; of these 17 were viral, 14 bacterial, and 3 due to Mycoplasma. Four surgical complications were reported: 1 graft artery stenosis, 1 ureteral stenosis, 1 urinary leak, and 1 lymphocele. Mean height standard deviation score improved from -2.0 +/- 1.3 pre transplantation to -1.8 +/- 1.4, -1.5 +/- 1.3, and -1.5 +/- 1.5 at 1, 2, and 5 years post transplantation. Linear growth was significantly better in infants treated with alternate-day steroids. Hypertension was a frequent complication, since 19 of the 30 patients with a 5-year follow-up were still being treated with antihypertensive drugs. In conclusion, graft survival in patients less than 6 years old is satisfactory and similar to that obtained in children aged from 6 to 18 years (70.5% vs. 78.9% at 5 years, P = NS). Consequently, since there are many difficulties in managing infants on maintenance dialysis, an early transplant should be considered. Donors older than 24 months carry a low risk of vascular thrombosis and may be successfully grafted in infants.

Child Development↗

Angiotensin converting enzyme inhibition worsens the excretory phase of diuretic renography for obstructive hydronephrosis.

PURPOSE: A growing body of evidence identifies the renin-angiotensin system as a key factor in the onset and progression of renal damage in chronic partial obstruction, which often represents a complex diagnostic challenge. A prospective study was undertaken to evaluate the role of captopril mercaptoacetyltriglycine-3 (MAG-3) renography as an early diagnostic test of obstruction. We report the results in a subgroup of children who underwent surgical correction for pyeloureteral obstruction. MATERIALS AND METHODS: Pyeloplasty was performed in 12 patients, including 10 males, 2 to 72 months old (median age 7) with unilateral hydronephrosis, including normal renal function and blood pressure. Basal and captopril enhanced diuretic renography with 99mtechnetium MAG-3 was performed within 24 hours using the same hydration and diuretic stimulus (0.75 mg./kg. furosemide), and 0.75 mg./kg. captopril was administered orally 60 to 90 minutes before scintigraphy. RESULTS: No adverse effects or modifications of the blood pressure were observed after captopril administration. The diuretic response was deeply worsened by angiotensin converting enzyme inhibition in each hydronephrotic kidney even when the basal study was only slightly abnormal (15-minute washout basal -27 +/- 16%, after captopril -9 +/- 13, p <0.005). After surgical correction the diuretic washout during angiotensin inhibition appeared normal in all patients (15-minute washout -56 +/- 14%). Separate renal function and parenchymal transit of MAG-3 were not modified by angiotensin converting enzyme inhibition, preoperatively or postoperatively. CONCLUSIONS: Our data confirm the influence of angiotensin on the kidney excretory system in human hydronephrosis and suggest a role for captopril enhanced diuretic renography in the early diagnosis of pyeloureteral obstruction. Further work is needed to evaluate angiotensin converting enzyme inhibition as a protective agent in obstructive nephropathy.

Angiotensin-Converting Enzyme Inhibitors↗

A multicenter survey on automated peritoneal dialysis prescription in children.

Automated peritoneal dialysis (APD) is considered the first-choice chronic peritoneal dialysis modality for pediatric patients. Nighttime APD courses reduce the impact of PD treatment on a patient's and family's way of life, and the wide range of prescription options permit the dialysis schedule to be tailored to the needs of children of varying age and body size. We registered data concerning the dialytic regimens adopted in 12 pediatric dialysis centers for the treatment of 110 children on APD. Of the 110 children, 64 (aged 7.6 +/- 5.1 years) were on nightly intermittent peritoneal dialysis (NIPD); 29 (aged 9.2 +/- 4.3 years) were on tidal peritoneal dialysis (TPD); and 17 (aged 8.2 +/- 4.9 years) were on continuous cycling peritoneal dialysis (CCPD). The main prescription parameters for the various regimens (mean +/- standard deviation) were these: NIPD--exchanges: 13.0 +/- 5.8; duration: 10.0 +/- 1.1 hours; dwell volume: 36.5 +/- 6.2 mL/kg body weight (BW); glucose concentration: 1.69% +/- 0.41%. TPD--exchanges: 23.3 +/- 8.1; duration: 10.0 +/- 1.0 hours; dwell volume: 36.1 +/- 5.9 mL/kg BW; glucose concentration: 1.63% +/- 0.37%. CCPD--exchanges: 13.0 +/- 4.7; duration: 10.1 +/- 1.3 hours; dwell volume: 37.7 +/- 5.2 mL/kg BW; glucose concentration: 1.65% +/- 0.28%. Tidal volume was 52.2% +/- 9.0% of initial fill volume. Daytime dwell volume was 54.8% +/- 17.3% of night volume in CCPD patients, and 56.6% +/- 13.3% in 9 patients on continuous TPD. Because the patient population in this report varied in age, body size, and metabolic needs, the resulting range in prescription parameters was quite wide. Nevertheless, the duration of nightly PD sessions averaged 10 hours, fill volume averaged 36 mL per kilogram body weight, and daytime volume averaged 50% of nighttime fill volume.

Child↗

Rapid and simple determination of inulin in biological fluids by high-performance liquid chromatography with light-scattering detection.

We report a new high-performance liquid chromatography method developed for measuring inulin in plasma and urine using ion moderated partition chromatography and evaporative light-scattering detection. Samples are deproteinized with a zinc acetate and phosphotungstic acid solution and added with melezitose as an internal standard. The chromatographic separation is carried out in 16 min at a flow-rate of 0.6 ml/min using deionized water as the mobile phase. Within-run precision, measured at four different concentrations (0.050 mg/ml, 0.150 mg/ml, 0.300 mg/ml and 1.200 mg/ml), ranges from 1.7 to 3.4% in plasma and from 1.5 to 3.5% in urine. Similarly, between-run precision is in plasma from 2.0 to 4.3% and in urine from 2.0 to 4.4%. Analytical recovery ranges from 97.9 to 100.1% in plasma and from 99.1 to 99.7% in urine, respectively. Detection limit (signal-to-noise ratio=3) is 5 microg/ml both in plasma and urine. The method is simple, sensitive, without interference due to hexoses or drugs commonly taken by patients with renal diseases, and offers the advantage of measuring inulin without previous hydrolysis of the molecule.

Adolescent↗

Hemolytic-uremic syndrome as a presenting form of acute lymphocytic leukemia.

We report an 8-year-old girl who presented with hemolytic-uremic syndrome (HUS) as the onset manifestation of acute lymphocytic leukemia (ALL). The patient was admitted to the hospital for renal failure, thrombocytopenia, and anemia during a HUS outbreak. She was discharged 2 weeks later with normal renal function. One month later the girl presented with clinical and laboratory signs consistent with a diagnosis of ALL. The short time interval between HUS and ALL suggests that HUS was probably an early manifestation of acute leukemia.

Child↗

De novo cancers in paediatric renal transplant recipients: a multicentre analysis within the North Italy Transplant programme (NITp), Italy.

The purpose of this study was to determine the frequency and the outcome of de novo malignancies in a cohort of renal transplant paediatric patients. The records of 493 kidney transplants, carried out in 454 paediatric recipients at the three paediatric transplant centres of the North Italy Transplant programme (NITp, Italy) were reviewed. 10 cases of malignancies (2.2%) comprising both PTLD (post-transplant lymphoproliferative disorders) (6 cases, 1.3%) and non-PTLD malignancies (4 cases, 0.88%) were reported. Non-PTLD included one urothelial carcinoma and one Wilms' tumour of the recipient's left native kidney, one abdominal dysgerminoma and one optic nerve glioma of the left eye. The PTLD consisted of localised or disseminated Epstein-Barr virus (EBV)--associated B-lymphocyte monoclonal (5 cases) and polyclonal (1 case) proliferations. All patients suffering from PTLD had been EBV-negative at the time of transplantation, but developed EBV primary infection after transplantation. All PTLD patient donors were EBV-positive. In addition, all but 1 patient received, before and/or after transplantation, a range of immunosuppressive drugs in addition to the baseline prophylactic immunosuppressive regimen. Moreover, 3 patients suffered from syndromes associated with a genetic predisposition to cancer. Finally, the malignancies reported here were associated with 20% graft failure and 20% mortality rates.

Adolescent↗

Renal glomerular response to the inhibition of prostaglandin E2 synthesis and protein loading after the relief of unilateral ureteropelvic junction obstruction.

PURPOSE: We investigated glomerular filtration rate and renal function reserve after the surgical relief of partial obstruction. MATERIALS AND METHODS: We evaluated 4 boys and 1 girl 9 to 14 years old who underwent pyeloplasty because of unilateral ureteropelvic junction obstruction. Contralateral normal kidneys served as controls. The glomerular filtration rate (inulin clearance), and urinary excretion of prostaglandin E2, thromboxane B2 and endothelin were determined at baseline and after a meal of 4 gm./kg. cooked unsalted red meat on day 4 postoperatively. Tests were repeated the following day 1 hour after the oral administration of 20 mg./kg. aspirin, an inhibitor of prostaglandin E2 synthesis. Urine was collected separately through a bladder catheter and another catheter placed in the upper renal pelvis at surgery. RESULTS: Glomerular filtration rate at baseline was significantly greater in normal than in surgically treated kidneys (77.2 ml. per minute, range 60 to 98 versus 63.6, range 43 to 78, p = 0.04). Aspirin did not change baseline inulin clearance in normal kidneys but it significantly decreased the glomerular filtration rate in operated renal units (-4% versus -26.4%, p = 0.04). The concentration of all vasoactive compounds was not significantly different in the urine specimens of normal and operated kidneys. The administration of aspirin resulted in a significant decrease in mean urinary prostaglandin E2 excretion plus or minus standard error in operated but not in normal renal units (0.64+/-0.12 ng. per minute versus 0.27+/-0.06, p = 0.04). When expressed as mean versus baseline values, protein induced glomerular hyperfiltration seemed lower in operated than in contralateral intact kidneys (6.9% and 12.4%, respectively). CONCLUSIONS: In the immediate postoperative period previously obstructed kidneys maintain renal function via mechanisms that depend on the activation of prostaglandin, mimicking normal renal function. This effect is decreased by drugs that inhibit prostaglandin E2 production. Therefore, renal damage may be present when the glomerular filtration rate appears normal.

Adolescent↗

Extracorporeal photochemotherapy after cardiac transplantation: a new therapeutic approach to allograft rejection.

UNLABELLED: Photopheresis (ECP) is a new immunomodulatory therapy in which recipient lymphocytes are treated extracorporeally with 8-methoxypsoralen and ultraviolet light. The treatment seems to induce an inhibition of both humoral and cellular rejection after transplantation. OBJECTIVE: Since recurrent rejection (RR) continues to be a severe complication after heart transplantation (HTx) and the immunosuppressive regimes used for the treatment are often associated with increased morbidity and mortality, we investigated whether ECP could have a beneficial effect on the number and severity of rejection episodes. METHODS: Eleven HTX recipients (5 M and 6 F, mean age 48.5 yrs) with RR were enrolled in the study. ECP was performed at weekly intervals during the 1st month, at 2 week intervals during the 2nd and 3rd month, and then monthly for another 3 months. RESULTS: The fraction of biopsies (EMB) with a grade 0/1A rejection increased during ECP from 46% to 72% while the EMB showing a 3A/3B rejection decreased from 42% to 18%. It is also noteworthy that out of the 78 EMB performed during ECP only one showed a 3B rejection in comparison with 13 out of 110 EMB in the pre-ECP period. Six rejection relapses were observed in a total follow-up of 60 months, two of them occurring during the tapering of oral steroid. Four relapses were reversed by ECP, one by i.v. steroids and the last by methotrexate after the failure of both i.v. steroids and ECP. The mean doses of immunosuppressive drugs resulted lower after 6 months of ECP: steroids were reduced from 13 to 8.25 mg/day, cyclosporine from 375 to 285 mg/day, azathioprine from 55 to 35 mg/day. CONCLUSIONS: ECP is a well tolerated treatment. Its administration allows better RR control and significant reduction in immunosuppressive therapy.

Adult↗

Rapid determination of creatinine in serum and urine by ion-pair high-performance liquid chromatography.

We report a simple and reliable high performance liquid chromatography method for measuring creatinine in serum and urine. The chromatographic run is performed on a C(18) column after protein precipitation with acetone and addition of cimetidine as an internal standard. The separation is carried out in 20 min at a flow rate of 0.8 ml/min, with a mobile phase consisting of 100 mmol/l sodium dihydrogen phosphate solution, containing 30 mmol/l sodium lauryl sulfate pH 3.0 and acetonitrile (60:36, v/v). The absorbance is monitored at 200 nm. The relationship between creatinine concentration and the creatinine/internal standard peak area is linear up to 1,088 micromol/l. Within-run precision measured at three different creatinine concentrations ranges from 0.89% to 2.34% in serum and from 0.34% to 1.10% in urine. Between-run precision varies from 1.68% to 3.17% in serum and from 1.58% to 1.85% in urine over a wide range of concentrations. Analytical recovery is between 98.71% and 101.25% in serum and between 98.96% and 100.27% in urine. The detection limit is 3.24 micromol/l for a signal-to-noise ratio of 3. The method shows a good linearity with the reference isotope dilution gas chromatography-mass spectrometry procedure (r=0.999), without interferences, even in the presence of high bilirubin concentrations.

Bilirubin↗