Child nephrology and urology最新文献

Transient renal insufficiency in the neonate is frequently the result of hypoperfusion of the kidneys due to circulatory compromise and is associated with a normal renal ultrasound scan. We describe an infant with transient renal insufficiency associated with hyperuricemia, hyperuricosuria and increased echogenicity of the renal medullary pyramids. Transient uric acid nephropathy may be a more common occurrence in the neonate than previously recognized.

OKT3 has become one of the more effective antirejection therapies for patients receiving kidney transplants. However, its usefulness is diminished or blocked by the development of antimouse/anti-OKT3 antibodies. We evaluated 17 children receiving OKT3 for steroid-resistant acute rejection for the development and persistence of antibodies after therapy. OKT3 was successful in reversing acute rejection in 14 of 17 patients. Eight children developed antimouse antibodies, 7 at a low titer (1:100). The retesting of all children 6 months later showed no detectable antibodies. Children develop anti-OKT3 antibodies at a rate similar to adults and with time lose detectable levels which may have significance if a subsequent course of OKT3 is needed.

Examination of the effects of dietary manipulation on progression of chronic renal failure (CRF) has been of interest for two reasons: dietary protein restriction is an effective method of ameliorating uremic symptoms and studies of changes in serum creatinine (and later, creatinine clearance or glomerular filtration rate, showed that the course of renal insufficiency is predictable. Results from studies of patients and animals with CRF suggested that a low-protein, phosphorus-restricted diet could slow the rate of loss of renal function. Animal studies have identified several mechanisms for progressive renal damage. These include glomerular hypertension causing capillary damage, glomerular damage from hypertrophic stimuli or hypermetabolism, calcium-phosphorus deposition and nephrotoxicity of the diet. The scientific basis for these different mechanisms will be discussed and each mechanism will be analyzed in terms of experimental studies in patients with CRF.

We performed both kidney ultrasonography (KUS) and intravenous urography (IVU) in 56 children with urinary tract infections (UTI) to compare the effectiveness of these procedures in detecting urinary tract malformations (UTMs). In 7 patients where KUS findings were interpreted as normal, IVU detected the following UTMs: hydronephrosis (3), stenosis of the pelvi-ureteric junction (2), pelvi-ureteric duplication (1) and kidney dislocation (1). In 2 other patients, mild hydronephrosis diagnosed by KUS was not confirmed by IVU. With respect to IVU, KUS revealed a sensitivity of 77.4% and a specificity of 92%. In our experience, IVU is still irreplaceable in the diagnostic protocol of UTMs in children; KUS should be regarded as a useful complementary procedure.

A technique for percutaneous renal biopsy in children is described which combines the use of ultrasound guidance and a disposable automatic biopsy device. Twenty-five biopsies in 22 children were performed using the Bard Monopty biopsy instrument. Adequate tissue was obtained to aid in diagnosis in 24 of 25 cases. Complications inclused 2 small perinephric hematomas. We conclude that the Bard Monopty biopsy device in association with ultrasonography provides for a safe and reliable technique to perform percutaneous renal biopsy in children.

In a sample of 28 children diagnosed as having idiopathic hypercalciuria, ultrasound studies showed nephrocalcinosis in 6 cases, the rest having normal sonographs. On biochemical comparison, the two groups were statistically distinguishable by means of three parameters. The group with nephrocalcinosis showed higher values of calciuria and calciuria versus magnesuria ratio (p less than 0.05), as well as lower maximum urinary osmolality (p less than 0.01) than the group with normal sonographs. A negative correlation was found between the calciuria values and the values obtained from the concentration test (p less than 0.05). At present, the factors favoring the deposit of calcium salts in children with idiopathic hypercalciuria are not yet fully known.

Abnormal sonographic findings were obtained in all cases of infantile idiopathic nephrotic syndrome (IINS). Hyperechoic renal parenchyma, subcapsular hypoechoic band and loss of cortical medullary differentiation were the commonest abnormalities. There was no specific sonographic difference between the different types of IINS. The subcapsular hypoechoic band is also not diagnostic for IINS. Abnormal sonographic findings indicate renal biopsy to identify specific types of IINS.

Subclavian vein catheterization is a relatively safe procedure. Few long-term complications have been reported. We recently diagnosed subclavian vein stenosis in a 14-year-old peritoneal dialysis patient. The stenosis occurred 2 years after the use of a subclavian vein catheter for temporary hemodialysis. Stenosis became clinically apparent by progressive painless swelling of the right arm and was documented by venography.

Anti-HBV vaccination was performed in 17 children with chronic renal insufficiency on conservative treatment and in 29 control children. The response to vaccination was satisfactory in patients as well as in the control group and no significant difference was found between the two groups as to percentage of responders and to the titre of HBsAb produced. It appears reasonable to vaccinate all patients with chronic renal insufficiency before they reach end-stage renal disease in areas with high prevalence of HBV infection.