The ratios of urinary markers of tubular function, including U-β2MG, U-NAG and U-Ca, to Cr vary by age, being higher in younger children. In contrast, the ratios of urinary markers of glomerular filtration (such as U-Pr)to Cr do not vary by age, making them suitable for corrections relative to Cr.

We evaluated the prevalence and the types of infectious foci in oral as well as ear, nose, and throat diseases, and we examined incidence of renal involvement with active treatment for focal infection in children with Henoch-Schönlein Purpura. A total of 96 children who presented at Aichi Children's Health and Medical Center and were diagnosed as having HSP were evaluated for infectious foci in the ear, nose, throat, and oral cavities. Seventy-one of 96 children (74.0%) had some type of infectious lesion, such as sinusitis or tonsillitis, and the prevalence of sinusitis was the highest (51 cases, 53.7%). In 44 HSP patients without renal involvement at the first examination, the incidence of nephritis was lower (13.6%) than in previous reports (17–54%) due to our aggressive intervention for infectious foci.

Cr secretion by renal tubules was approximately 50 % of the GFR. In this study, we indicate that the measurements of 2-h Ccr or 24-h Ccr do not show true GFR but we could infer approximate GFR from the values. The use of 2- or 24-h Ccr might contribute to the treatment of pediatric CKD patients.

The absence of pyuria in transurethral catheterization urine sediments does not rule out UTI. Pyuria in bag-collected urine specimens frequently consists of urine leukocytes from external genitalia as well as from the urinary tract.

BACKGROUND: Due to their active growth, children require more protein intake than adults. We therefore hypothesized that dialysis dosage should be greater in children than in adults to achieve an equivalent BUN level. We assessed unmeasured nitrogen losses to determine whether a higher dialysis dosage is required in pediatric than in adult peritoneal dialysis (PD) patients. METHODS:We examined urea kinetics 25 times in 13 pediatric patients divided into three age groups: Ͻ5 years, Ն5 and Ͻ10 years, and Ն10 years. Nutrient intake was calculated over 3 days, dietary protein intake (DPI) was averaged, and protein equivalent of nitrogen appearance rates (PNA) were calculated. Anabolism by growth was added to the PNA to calculate the corrected PNA, and the corrected PNA/DPI was compared among the three age groups.RESULTS: Median corrected PNA/DPI differed signifi cantly among the three age groups (p Ͻ 0.001), with a signifi cant positive correlation between age and corrected PNA/DPI (p Ͻ 0.001). Unmeasured nitrogen losses were 43.7% in children aged Ͻ5 years, 27.9% in children Ն5 and Ͻ10 years, and 10.7% in children aged Ն10 years.CONCLUSIONS: Unmeasured nitrogen losses should be considered when determining the delivered PD dose by Kt/V urea in children, because these losses are greater in children with PD, especially in infants, than in adults. Therefore, it is not necessary for dialysis dosage to be greater in children than in adults, even when aiming for equal BUN concentrations.