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Biomedical subjects

G Zilleruelo

Publications and source records attributed to G Zilleruelo.

At least 19 recordsLinked to original sources
PubMed2003

Beneficial effects of continuous overnight catheter drainage in children with polyuric renal failure.

OBJECTIVE: To determine the possible beneficial effect of providing decompression of the collecting system by continuous overnight catheter drainage (COCD) in children with progressive renal disease and dysfunctional bladder syndrome, commonly associated with polyuria which may overwhelm bladder capacity. PATIENTS AND METHODS: COCD was used in seven patients (four boys) with progressive polyuric kidney failure associated with dysfunctional bladders (current age 18.7 years, SD 5; age at COCD 12 years, SD 6). Five children had surgical bladder augmentation and all were prescribed daytime intermittent catheterization (IC) for a mean (SD) of 4.7 (3.4) years before COCD. All had significant polyuria, with a mean (SD) urine output of 2370 (971) mL/m2 per day. RESULTS: The mean (SD) glomerular filtration rate at the start of COCD was 48 (21) mL/min/1.73 m2, which is currently stable in the five patients continuing treatment. The mean (SD) duration of COCD was 4.9 (2) years. One patient showed no improvement and had a pre-emptive transplant within 1.2 years; another was transplanted after 5.5 years. Six patients showed evidence of benefit from COCD, with significant attenuation in the slope of renal functional decay (P = 0.02) and a mean (sd) prolongation of the predicted time to end-stage renal disease of 12.2 (5.6) years (P < 0.002). Hospitalization for febrile urinary tract infections was decreased from a mean (sd) of 1.7 (1.4) to 0.4 (0.7) times (P = 0.03) in the first year of COCD and eliminated by the second year (P < 0.01). CONCLUSION: COCD of the dysfunctional bladder in patients with progressive polyuric renal failure appears to offer the potential for preserving kidney function in selected patients. It does not replace surgical bladder augmentation or daytime IC in the core management.

Child↗
PubMed2001

Angiotensin-II and endothelin-1 levels in children with renoprival hypertension.

Children with end-stage renal disease (ESRD) often remain hypertensive despite bilateral nephrectomy and aggressive fluid removal on hemodialysis. We speculated that an extrarenal source of renin might contribute to the release of "tissular" angiotensin-II (AT-II) generating hypertension in anephric patients. At the same time, experimental evidence supports that peripheral AT-II vasoconstrictive effect is likely mediated by endothelin-1 (ET-1). Thus, it is conceivable that hypertension in ESRD patients may be due, in part, to a cascade involving vascular production and secretion of AT-II and ET-1. In order to establish the relationship between AT-II, ET-1, and blood pressure we performed a pilot study to measure predialysis systolic and diastolic blood pressures (SBP and DBP, respectively) and serum AT-II and ET-1 levels in 12 anephric children receiving hemodialysis. Predialysis AT-II and ET-1 levels were similar in all patients, and neither value correlated with their mean SBP or DBP. In patients with postdialysis hypertension, there was no correlation between predialysis AT-II and ET-1 plasma levels. We therefore find no evidence to suggest that vascular-mediated AT-II and/or ET-1 contributes significantly to hypertension in anephric patients.

Adolescent↗
PubMed2001

Identification of poor responders to erythropoietin among children undergoing hemodialysis.

OBJECTIVES: To identify the factors determining a high recombinant human erythropoietin (rHuEPO) dose requirement and associated side effects in children undergoing hemodialysis. STUDY DESIGN: We retrospectively analyzed the clinical data of 23 children (aged 5-20 years) undergoing long-term hemodialysis. All subjects received intravenous rHuEPO to maintain hemoglobin levels > or = 10 g/dL and had iron supplement. Subjects were divided into 2 groups: those receiving high-dose rHuEPO (> or = 450 U/kg/wk) and those receiving an average dose (< 450 U/kg/wk). We compared the specific variables between both groups by using Mann-Whitney, Fisher exact, and linear regression tests; a P value < .05 was considered significant. RESULTS: Four of 23 subjects (17%) received high-dose rHuEPO despite iron repletion. These subjects were small and young and had frequent bacterial infections, high ferritin levels, and severe hyperparathyroidism. Two patients with human immunodeficiency virus infection required high-dose rHuEPO. The main adverse effect of high-dose rHuEPO was an increase in the heparin requirement during hemodialysis. CONCLUSIONS: Age, body weight, inflammatory status, and severity of hyperparathyroidism should be taken into account when adjusting rHuEPO dose for children undergoing hemodialysis. Furthermore, we suggest that high rHuEPO doses are related to an increase in the heparin requirement in these children.

Age Factors↗
PubMed2000

Diuretic MAG3 scintigraphy (F0) in acute pyelonephritis: regional parenchymal dysfunction and comparison with DMSA.

UNLABELLED: 99mTc-DMSA late static planar imaging or SPECT is being used for the investigation of focal acute pyelonephritis (APN), especially in children with urinary tract infection (UTI). Diuretic 99mTc-mercaptoacetyltriglycine (MAG3) dynamic scintirenography has been applied in the evaluation of kidney function and structure, frequently to exclude obstruction. However, in children and adults with a clinical picture of APN, diuretic MAG3 scintigraphy with zero time injection of furosemide (MAG3-F0) was observed to display focal parenchymal abnormalities; regional dysfunction (focal parenchymal decrease in early uptake; slow filling in and prolonged late retention of activity); or, less frequently, fixed defects. This observation was further studied both retrospectively and prospectively, and its sensitivity and specificity for APN were compared with those of dimercaptosuccinic acid (DMSA). METHODS: In the retrospective study, for 36 children with UTI and regional parenchymal findings on MAG3-F(0), data were reviewed, analyzed, and compared with the results of concurrent DMSA studies. In the prospective study, for 57 children with clinical and laboratory findings suggestive of APN, the 2 radiopharmaceuticals were used for imaging sequentially and the results of the 2 studies were compared. The criteria for abnormal findings compatible with the diagnosis of APN were, for MAG3-F(0), regional parenchymal dysfunction and fixed focal defects and, for DMSA, focal defects without parenchymal loss. RESULTS: In all groups of patients, most abnormal MAG3-F(0) studies (80%) showed regional parenchymal dysfunction, but in some (20%) a fixed defect was found. Compared with DMSA and when both regional dysfunction and focal defects were considered, MAG3-F(0) was as sensitive as DMSA. Some patients had only MAG3-F(0) abnormalities, suggesting a slightly lower specificity for MAG3-F(0) compared with DMSA (86%); this finding needs further study, because it also raises questions about the sensitivity of DMSA, considering that only a small percentage of patients with clinically suggestive findings had abnormal study findings. In most patients with fixed defects on both DMSA and MAG3-F(0), follow-up studies showed no resolution, suggesting that a fixed defect on MAG3-F(0) may indicate either more severe APN or preexistent scars and that regional dysfunction may be a sign more specific for APN and prognostic of potential recovery. In addition, a pattern more specific for a scar--a fixed defect with a dilated regional calyx--was seen on follow-up MAG3-F(0). CONCLUSION: A fast (25-min) planar dynamic MAG3-F(0) study was found to be as sensitive at depicting focal parenchymal abnormalities in APN as was the 3- to 4-h DMSA routine procedure. The sensitivity and specificity of both studies need further evaluation.

Acute Disease↗
PubMed1999

Survival and complications of cuffed catheters in children on chronic hemodialysis.

Central venous catheters are being increasingly used as hemodialysis vascular access. We evaluated catheter survival, outcome predictors, and complications in a total of 36 catheters used in 13 children and young adults undergoing chronic maintenance hemodialysis through catheter for a duration of 10.4+/-5.6 months. Reasons for catheter failure were: thrombosis 12 of 36 (33%), infection 6 of 36 (17%), and extrusion 2 of 36 (5.4%). Catheters were lost to infection and thrombosis at 1.1 and 2.2 episodes per 1,000 catheter days, respectively. Symptomatic infections, Gram-negative and polymicrobial sepsis increased the risk of catheter failure. Most of the thrombotic episodes occurred in patients with inherent thrombotic tendency. The survival of the 36 catheters was 62% at 1 year. The survival of 13 randomly chosen catheters, 1 from each patient, was 85% at 1 year. The time from insertion to first complication correlated significantly with the outcome (P<0.03). We conclude that central venous catheters are still associated with a high rate of failure and may be a regular access choice only in a selected patient population with no inherent thrombotic tendency and no other option available for long-term hemodialysis.

Adolescent↗
PubMed1999

Abnormal urinary acidification in infants with hydronephrosis.

Distal renal tubular abnormalities have been observed in patients with dilated urinary tract disorders. The present study was undertaken to look for patterns in urinary acidification in infants with varying degrees of hydronephrosis due to either reflux or obstruction and occurring as unilateral or bilateral disease. Three groups of infants (mean age 3.7+/-3.8 months) were studied prospectively. Groups IA and IB included patients with hydronephrosis who were acidotic and non-acidotic, respectively. Group II served as controls and consisted of patients with diarrhea and secondary metabolic acidosis with no known renal disease. Serum electrolytes, creatinine, and urine pH were measured in all patients. Urinary titratable acidity, ammonium (NH4), and net acid excretion (NAE) were measured by the titrimetric method. Infants with hydronephrosis demonstrated lower urinary buffering capacity, reflected in low NAE in the face of acidosis. Deficiencies were noted in both titratable acid and NH4 excretion compared with control infants. Acidosis was as common in unilateral as in bilateral disease, regardless of severity score. These data confirm a defect in distal urinary acidification in infants with hydronephrosis, whether unilateral or bilateral. Immaturity and endogenous acid load may play a significant role in the manifestation of metabolic acidosis with unilateral disease.

Female↗
PubMed1998

Fungal peritonitis in pediatric patients.

Fungal peritonitis (FP) is a rare complication of peritoneal dialysis (PD). Although treatment with fluconazole (FCZ) has improved catheter survival and preservation of the peritoneal membrane, FP still carries a high morbidity and mortality in pediatrics. High-risk factors for FP include previous usage of systemic antibiotics and recurrent bacterial peritonitis. A prospective experience in the treatment of FP was conducted at the University of Miami/Jackson Children's Hospital from 1992 to 1997. All patients received either oral or intravenous loading dose of FCZ (5-7 mg/kg) followed by intraperitoneal (i.p.) FCZ (75 mg/L). Amphotericin B (amp B) was added when clinical sepsis was present. A total of 6 patients had FP (all Candida sp.; mean age: 6 years). Two of these patients were neonates with Tenckhoff-catheter placement at less than 1 week of age. Five patients achieved sterilization of the peritoneal fluid. One patient required catheter removal (C. tropicalis). The 2 neonates were infection free for 29 and 41 days, respectively, but both died of superimposed bacterial sepsis. The remaining 4 patients survived and completed 6 weeks of FCZ treatment. Two have had preservation of the peritoneal membrane for more than 1 year. The other 2 were switched to hemodialysis. We conclude that FCZ is an effective treatment for fungal peritonitis in pediatric patients. Adjunct therapy with amp B is usually necessary if sepsis is present. Although eradication of the fungus is possible in a majority of cases, neonates and immunocompromised hosts remain at high risk for morbidity and mortality.

Adolescent↗
PubMed1996

Validity of random urines to quantitate proteinuria in children with human immunodeficiency virus nephropathy.

Accurate assessment of proteinuria in pediatric patients infected with the human immunodeficiency virus (HIV) is limited by constraints imposed by timed urine collections and low creatinine excretion in very ill patients with low muscle mass. We therefore sought to validate the use of random urine specimens to quantitate total protein and creatinine excretion in a population of 236 HIV-positive children. A mathematical derivation for estimating urine volume (V) was constructed. The accuracy of the final calculation [V = 832 (kL/Ucr)BSA] (where k = constant, L body length, UCr urine creatinine and BSA body surface area) was tested by regression analysis comparing the calculated and measured volume of 31 urines from ambulatory HIV-negative patients. The correlation coefficient was highly significant (r = 0.77, P < or = 0.0001). The relationship was also applied to 23 timed urine specimens from HIV-positive patients with similar significance (r = 0.87, P < 0.0001). A regression analysis of measured proteinuria against the urine protein: creatinine ratio (Upr/Ucr) in these same urines from the HIV-positive patients yielded a significant relationship both in the linear (r = 0.95, y = 0.4x) and the logarithmic regression (r = 0.97, y = x + 0.4). These data support the use of random Upr/Ucr ratios to estimate daily proteinuria in HIV-infected pediatric patients despite low creatinine excretion rates. The previously accepted values continue to apply, with Upr/Ucr < or = 2.0 considered normal and > 2.0 representative of nephrotic proteinuria.

Adolescent↗
PubMed1996

Renal tubular abnormalities in infants with hydronephrosis.

PURPOSE: Abnormalities in renal tubular function have been observed in hydronephrotic urinary tract disease, resulting in metabolic acidosis, hyperkalemia and excessive free water diuresis. The frequency of these abnormalities, particularly in our infant population, was the impetus for our study. MATERIALS AND METHODS: We studied 50 infants selected from 199 patients followed for hydronephrosis before any surgical intervention during a 5-year period. Mean patient age was 1.5 +/- 1.0 months at the time of diagnosis by ultrasound, voiding cystourethrography and a radionuclide renal scan. Lesions were classified as unilateral or bilateral and graded according to severity of renal pelvic dilatation or grade of vesicoureteral reflux. RESULTS: At least 1 abnormality of tubular function was present in 29 patients (58%) of whom the predominant abnormality was renal tubular acidosis in 23 (79%, 46% of the total study group). Renal tubular acidosis was diagnosed on the basis of a serum total carbon dioxide of 19 mM./l. or less with urinary pH 5.5 or greater. The defect appeared to be distal in most cases. Other abnormalities included defects in urinary concentrating ability in 10 patients (4 with unilateral urinary tract dilatation). Distal tubular aldosterone resistance in 6 patients (3 with unilateral dilatation) was demonstrated by hyperkalemia with a low transtubular potassium gradient of 3 or less and low fractional excretion of potassium. Although common in unilateral lesions, renal tubular dysfunction became more prevalent with an increase in severity score and bilaterality. CONCLUSIONS: Renal tubular dysfunction is frequent in hydronephrotic infants with unilateral or bilateral disease. Although rarely life threatening and usually self-limiting, the metabolic consequences of these abnormalities require investigation to allow for appropriate medical management.

Female↗
PubMed1995

HIV nephropathy in children.

The evaluation and management of children with HIV nephropathy provide a great challenge to the pediatric nephrologist caring for patients with this tragic illness, of which the nephropathy is only part of their problem and extends beyond the patient to the family and all of the supportive team involved. Care decisions should be based on a multi-disciplinary approach in which the infectious disease component is included. There are many areas that require a better understanding, particularly the pathogenesis of HIV nephropathy and the approach to treatment of the nephropathy with specific drugs. Early identification of children affected with this condition and an aggressive approach to management seem essential to the improvement of the outcome of these patients.

AIDS-Associated Nephropathy↗
PubMed1993

Growth of uremic infants on forced feeding regimens.

Infants born with congenital renal insufficiency generally grow poorly during the first years of life and incur a height deficit that is rarely regained. Actual energy and protein requirements have not been determined for these children. In 12 infants with creatinine clearances less than 70 ml/min per 1.73 m2, growth and nutrient intakes were monitored during the first 2 years of life. Forced feeding regimens after 3 months of age, including gastrostomy in 3 patients, were necessary to maintain energy intakes near 100% of the recommended dietary allowance (RDA). Protein intakes averaged in excess of 140% RDA. Linear growth did not correlate with either energy or protein intakes, suggesting that neither was a limiting factor to growth. Length velocity standard deviation score (LV-SDS) did not correlate with degree of renal insufficiency at any age, but average LV-SDS did relate significantly and inversely to C-terminal parathyroid hormone (PTH) levels. Growth parameters, including LV-SDS and weight velocity SDS (WV-SDS) were lowest at 6 months of age. Weight and length SDS followed with a maximum decline at 12 months of age. While weight for length SDS remained normal and WV-SDS showed recovery during the 2nd year, LV-SDS remained negative. Length SDS stabilized near--2 SDS. In summary, these data suggest that the major height deficit in infants with renal insufficiency is incurred during the first 6 months of life. Ponderal indices suggested that very early nutritional deficits may have been a primary contributor to subsequent height deficits.(ABSTRACT TRUNCATED AT 250 WORDS)

Enteral Nutrition↗
PubMed1993

Human immunodeficiency virus nephropathy.

Varying components of the syndrome of human immunodeficiency virus nephropathy (HIVN) have been described, the most pertinent including proteinuria/nephrotic syndrome, progressive azotemia, normal blood pressure, enlarged and hyperechoic kidneys, rapid progression to end-stage renal disease (ESRD), and no response to treatment regimens. The diagnosis of HIVN requires identification of excessive proteinuria or albuminuria, determined by a total protein excretion on a timed urine collection or a high protein/creatinine ratio in a random specimen. Various pathological lesions have been found in HIVN. The lesion of focal and segmental sclerosis (FS/FSS) is most characteristic in adults and usually is associated with a rapid demise. FS/FSS also has been described in approximately one-half of the pediatric patients reported in the literature (31/64). Despite progression to ESRD, the clinical course in children with HIVN is less fulminant than in adults. Other reported histological findings include primarily mesangial hyperplasia as well as minimal change, focal necrotizing glomerulonephritis or lupus nephritis, and hemolytic uremic syndrome. In addition to glomerular pathology, interstitial findings of dilated tubules filled with a unique proteinaceous material, atrophied tubular epithelium, and interstitial cell infiltration are very common. On electron microscopy, most investigators have found tubuloreticular inclusion bodies in endothelial cells of glomerular capillaries. Treatment of patients who develop ESRD remains highly controversial. Most adult patients treated with hemodialysis have succumbed rapidly; peritoneal dialysis has been better tolerated. Transplantation in patients with HIV infection must be considered to be tentative, with reports of acceleration towards full blown acquired immunodeficiency syndrome in some and uneventful 5-year survival in others.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1991

Clinical management of the pediatric renal-allograft recipient.

Management of the pediatric renal-transplant recipient requires careful pretransplant evaluation including psychosocial assessment and cautious donor/recipient selection. Early transplantation is preferable in infants less than 1 year of age if a suitable live-related donor is available. However, cadaveric-allograft transplantation is best reserved for patients older than 3 years with donors older than 5 years. Pre-emptive transplantation is suitable for approximately one fifth of the population. Medical preparation includes careful HLA-A, -B, and -DR loci matching, interferon treatment for positive hepatitis antigenemia, and acyclovir prophylaxis for a cytomegalovirus (CMV) antibody-negative patient to a seropositive donor. Postoperative management requires close monitoring of the patient's volume status with careful fluid replacement in the form of colloid and crystalloid. Immunosuppression involves multiple drug regimens that include corticosteroids, ciclosporin, azathioprine, antilymphocyte (or -thymocyte) globulin (ALG/ATG), monoclonal antibodies (OKT3), and a ciclosporin alternative: FK-506. Long-term complications dictate management and are divided into medical, surgical, immune, and infectious categories. These are predominated by treatment of acute and chronic rejection, hypertension, and CMV infection.

Blood Transfusion↗
PubMed1990

Quantitation of proteinuria with urinary protein/creatinine ratios and random testing with dipsticks in nephrotic children.

We examined the relative feasibility of using random urinary dipstick testing and urinary protein/creatinine ratios in the quantitation of proteinuria. Sixty-four children with relapsing nephrotic syndrome, ranging in age from 1 1/2 to 16 years, contributed 145 timed urine collections and 150 random specimens, which were analyzed by urinary protein dipstick, quantitation of protein and creatinine, or both. Total protein excretion was expressed as grams per surface area per day and the urinary protein/creatinine ratio as milligrams of protein per milligram of creatinine. Degrees of proteinuria were designated as physiologic (less than 0.1 gm/m2/day), intermediate (greater than 0.1 and less than 1.0 gm/m2/day), or nephrotic (greater than 1.0 gm/m2/day). The log regression analysis of the 24-hour urinary protein/creatinine ratio (y) and total protein excretion (x) was highly significant (r = 0.97; p less than 0.001). The upper and lower confidence limits of the urinary protein/creatinine ratio (1.0 and 0.1, respectively) closely approximated the designations for nephrotic and physiologic proteinuria, respectively. These values were therefore used to classify degrees of proteinuria by the urine protein/creatinine ratio. The validity of these tests was assessed by sensitivity, specificity, and predictive value, and compared with that of random testing by urinary dipstick. The urinary protein/creatinine ratio offered good reliability as a test for classifying degrees of proteinuria and accurately predicting nephrotic and physiologic proteinuria. The random dipstick testing was reliable only when results were distinctly positive and when sensitivity and specificity were low. The error in the total protein excretion value that was imposed by collection errors with high and low variations in the creatinine value (57% of samples) was largely corrected by normalization of the data by log transformation. When controlled for creatinine excretion, linear regression analysis allowed calculation of total protein excretion (TP) from the urinary protein/creatinine ratio (U P/Cr) by the following equation: TP (gm/m2/day) = 0.63 (U P/Cr) at all levels of proteinuria. The random urinary protein/creatinine ratio appeared to offer the most sensitive test for classification of proteinuria in children with nephrosis, with the advantages of ease and expediency not afforded by the 24-hour urine quantitation.

Adolescent↗
PubMed1989

Renal disease in children with the acquired immunodeficiency syndrome.

Of 155 children with the acquired immunodeficiency syndrome (AIDS) whom we evaluated during a 6 1/2-year period, 12 were found to have proteinuria. Histologic studies of tissue from these 12 patients revealed a wide spectrum of renal disease: focal glomerulosclerosis in 5, mesangial hyperplasia in 5, segmental necrotizing glomerulonephritis in 1, and minimal change disease in 1. In addition, 6 had tubulointerstitial infiltrates, and 10 had glomerular dense deposits. All 10 renal specimens studied by electron microscopy contained endothelial tubuloreticular inclusions. The mean age (+/- SD) of the five patients with focal glomerulosclerosis when this condition was identified was 27 +/- 19 months. All five had severe renal failure within a year and died of other causes during the following year. The mean age of the five patients with mesangial hyperplasia was 38 +/- 31 months. Although none of them went on to have renal failure, four died within 8 +/- 7 months. Ten of the 12 patients with proteinuria died during the study period. Of the two surviving, one had mesangial hyperplasia and the other had minimal change disease. We conclude that children who acquire human immunodeficiency virus (HIV) infection during the perinatal period may have renal disease, most often focal glomerulosclerosis, as is the case in adults, or mesangial hyperplasia. Although 5 of the 12 children we studied had renal failure during the study period, none died of it. Further studies are needed to determine the correlations between clinical and pathological features and the pathophysiology of AIDS nephropathy in children.

Acquired Immunodeficiency Syndrome↗