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Biomedical subjects

U Alon

Publications and source records attributed to U Alon.

At least 37 records · Page 2Linked to original sources

Aplasia of the cerebellar vermis associated with chronic renal disease. A report of six cases and a review of the literature.

UNLABELLED: We report six patients with aplasia or hypoplasia of the cerebellar vermis with early symptoms consisting of psychomotor retardation, nystagmus and severely reduced visual acuity due to congenital amaurosis. At age 5.6-12.1 years, five of these patients developed symptoms of chronic renal failure due to renal maldevelopment. CONCLUSION: Children presenting with vermis aplasia should be monitored for associated disorders, especially renal disease.

Blindness↗

Assessment and interpretation of the tubular threshold for phosphate in infants and children.

Studies in the last decade demonstrated that in children tubular maximum phosphate reabsorption per glomerular filtration rate (TmP/GFR) is identical to TP/GFR; TP indicating tubular phosphate reabsorption under basal conditions, without phosphate load. TP/GFR is calculated from the formula TP/GFR = SP-UP x SCr:UCr, based on simultaneous urine and blood creatinine and phosphate concentrations, and is applicable in both the fasting and non-fasting child. These studies also demonstrated that the use of Walton and Bijvoet nomogram in children may result in overestimation of TmP/GFR compared with TP/GFR calculated from the above formula. When using the formula, one should bear in mind that creatinine is used to express GFR and as a result a significant deviation from true GFR may occur in patients with renal failure. Therefore when employing TP/GFR for the investigation of the renal handling of phosphate in children, three factors should be taken into consideration: (1) the formula in reality expresses TP/CCr; (2) only data obtained by exactly the same methodology can be used as reference values; data obtained from studies in which the nomogram was utilized or in which methods other than CCr were used to measure GFR should not be used for reference; (3) in patients with renal failure, TP/CCr will significantly overestimate TP/Cinulin.

Absorption↗

Vitamin status of infants receiving long-term peritoneal dialysis.

The oral vitamin intakes and blood vitamin concentrations of seven infants receiving long-term peritoneal dialysis were measured. The serum concentrations of vitamin A, vitamin B12, vitamin C and folic acid were determined. Thiamine and riboflavin were assessed by the activation of erythrocyte transketolase and erythrocyte glutathione reductase, respectively. Vitamin B6 was measured as plasma pyridoxal phosphate. All patients received a daily vitamin supplement devoid of vitamin A. Dietary vitamin intake was derived from infant formula. In all cases, the patients' blood concentrations of the water-soluble vitamins were equal to or greater than normal infant values. Serum vitamin A levels were elevated despite the lack of supplementation. The combined dietary/supplemental water-soluble vitamin intake of the patients exceeded the recommended daily allowance in all but one patient. These preliminary data emphasize the need to further evaluate the vitamin requirements of infants receiving long-term peritoneal dialysis.

Diet↗

A seven year experience with kidney transplantation for pediatric end stage renal disease.

Renal transplantation for pediatric end stage renal disease (ESRD) is a preferred option in dealing with these chronically ill patients. The pediatric renal transplant program at University of Missouri-Kansas City School of Medicine was begun in 1986 at St. Luke's Hospital and subsequently shifted to the Children's Mercy Hospital as experience was accumulated. To date 35 transplants have been performed in 31 recipients. Fifty-one per cent of the patients transplanted were adolescents (older than 13 years) and 91% of the patients were older than 4 years. Sixteen of the 35 transplants were from living related donors and 19 patients received their kidneys from cadaveric donors. Immunosuppression consisted of corticosteroids, azathioprine, cyclosporine and antilymphoblast globulin. No patients died following transplantation with a functioning kidney. Allograft survival with living related transplants at one year and three years was 91% and 86% respectively. Cadaveric allograft survival at one year and three years was 78% and 46% respectively. Most kidneys were lost due to either acute or chronic rejection although there were three patients who lost their kidney due to primary nonfunction, including one child age 23 months. The growth pattern of all but the youngest children (< or = 2 years) following transplantation showed no evidence of accelerated growth. Results in this early series of pediatric renal transplant patients is encouraging from the standpoint of patient and allograft survival and even though accelerated growth is not seen in the older children, it seems to offer a better quality of life for children with end stage renal disease.

Adolescent↗

Symptomatic peritoneal calcification in a child: treatment with tidal peritoneal dialysis.

OBJECTIVE: To evaluate the ability of tidal peritoneal dialysis to decrease the pain and frequency of hemoperitoneum associated with peritoneal calcification. DESIGN: Prospective case evaluation. SETTING: The Home Peritoneal Dialysis Unit, Children's Mercy Hospital. PATIENT: Seven-year old male with diffuse peritoneal calcifications, daily abdominal pain, and recurrent hemoperitoneum. INTERVENTION: Tidal peritoneal dialysis was conducted with an initial fill volume of 45 mL/kg and a tidal inflow volume of 23 mL/kg. The patient also maintained a daytime pass volume of 45 mL/kg. Duration of treatment was 7 months. RESULTS: The patient's abdominal pain resolved 2 days after initiating tidal peritoneal dialysis. No episodes of hemoperitoneum or abdominal pain have occurred for 7 months. CONCLUSION: Tidal peritoneal dialysis is a unique approach to the achievement of symptomatic relief in the patient with peritoneal calcification.

Abdominal Pain↗

Neuroblastoma in a renal transplanted child.

A 3-year-old boy was diagnosed with neuroblastoma 2 years after a renal transplant that was complicated by acute and chronic rejection. Extensive immunosuppressive therapy may have contributed to the development or progression of this tumor which has not been described previously following organ transplantation.

Acute Disease↗

Aminoglycoside ototoxicity in pediatric patients receiving long-term peritoneal dialysis.

We evaluated 14 children on long-term peritoneal dialysis for ototoxicity associated with aminoglycoside (AG) therapy. Baseline evaluation of all patients and 7 controls included pure-tone audiometry (PTA) and click-evoked auditory brain stem response (ABR). Nine patients had repeat PTA and ABR evaluations and vestibular testing 1 year after study entry. Five patients had an additional assessment following intraperitoneal AG therapy. The baseline auditory function of the patients was significantly poorer than controls at 6.0 and 8.0 kHz by PTA (P < 0.05), whereas the results of ABR testing were not different. Of the 14 patients, 4 (28%) had hearing loss, 3 of whom had a history of intravenous AG therapy. In contrast, none of the patients who received intraperitoneal AG therapy only, or without a history of AG therapy, had hearing loss (P < 0.005). There was no evidence of progressive loss of hearing acuity with time or associated with intraperitoneal AG therapy. One patient had findings of vestibular dysfunction. We conclude that children receiving peritoneal dialysis are at risk of AG ototoxicity. While intraperitoneal administration of AG may be associated with less ototoxicity than intravenous administration, further study is necessary to verify this finding and close monitoring of AG levels remains mandatory irrespective of the route of administration. PTA rather than click-evoked ABR appears to be the best indicator of abnormal hearing acuity in this population.

Adolescent↗

Cerebral vasculitis in acute post-streptococcal glomerulonephritis.

Neurological complications in acute post-streptococcal glomerulonephritis (APSGN) have been traditionally attributed to hypertensive encephalopathy. A 9-year-old girl with biopsy-documented APSGN developed seizures at a time she was normotensive and biochemically well balanced. Computed tomography of her brain was consistent with vasculitis, a finding which was also clinically supported by apparent vasculitic involvement of other organ systems. All clinical, laboratory and radiological abnormalities resolved with recovery from the APSGN. We suggest that on rare occasions neurological complications in APSGN may result from involvement of the central nervous system in multiorgan transient vasculitis.

Acute Disease↗

The renal clearance and infusion clearance of inulin are similar, but not identical.

Thirty-eight simultaneous renal (R-Cin) and infusion (INF-Cin) clearances of inulin were done. The equilibration period preceding the clearance studies was of at least two hours duration. The R-Cin on each subject was based on two clearance periods during which the plasma inulin concentration ([P(in)]) varied by 1.0 mg/dl or less and the rate of inulin excretion by less than 10%. There was excellent correlation between the R-Cin and the INF-Cin (r = 0.976), but the INF-Cin consistently exceeded the R-Cin (mean difference = 13.8 +/- 8.8 ml/min/1.73 m2, t = 9.7163 and P = < 0.001). Complete equilibration of inulin in body fluids has been assumed when [P(in)] levels were relatively constant (variation < 10%). However, complete equilibration of inulin would not be present, even with relatively constant P(in) levels, if the rate of infusion of inulin were equal to the rate of excretion plus the rate of penetration of inulin into less permeable components of the extracellular fluid compartment (that is, dense connective tissue solids). Estimation of glomerular filtration rate using the INF-Cin requires complete equilibration of inulin in body fluids, a process probably requiring 12 to 15 hours or longer.

Adolescent↗

The kidney in systemic disease: Part II--Autoimmune and vascular disorders.

The long-term outlook for the pediatric patient with lupus nephritis has improved dramatically over the past several decades. In 1968, Meislin and Rothfield compared childhood with adult SLE and found the prognosis to be worse when disease onset was at the age of 15 years or younger. Children with renal disease had only a 42% 5-year survival rate vs. an 82% survival rate in adults. Caeiro et al. found the 10-year survival rate in childhood to be only 48%. However, more recent data have demonstrated comparable results for patients of all ages. Ten-year patient survival rates have improved to 69% to 85% as a result of better immunosuppressive therapy, more effective antibiotics, and improved control of hypertension. Despite this overall improvement, severe renal disease continues to complicate the course of 20% to 35% of patients with SLE originating in childhood and demands further investigation of newer therapeutic measures.

Autoimmune Diseases↗