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.

The deterioration rate of creatinine clearance (CCr) was studied in 40 children with chronic renal failure (CRF) on conservative treatment followed up for at least 1 year (range 1-12). The deterioration rate of CCr was significantly (p less than 0.01) higher in glomerulopathies (G) than in hypoplasias (H) and in vascular nephropathies (VN) and significantly (p less than 0.01) higher in hereditary nephropathies (HN) than in VN. The differences in the deterioration rate of CCr between H and HN and between H and VN were not explainable on the basis of the different age at diagnosis or of the different prevalence of hypertension. These data indicate that the primary renal disease is important in determining the progression of CRF.

The incidence of hypertension (HT) in renal parenchymal disease of the young is very high, varying from 38 to 78%. This points to the central role of the kidneys in normal blood pressure control. HT in chronic renal failure (CRF) and end-stage renal disease (ESRD) depends on the nature of the underlying disease. The degree of renal failure has a highly variable effect. The clinical signs and symptoms of this form of HT are often superimposed on those of the basic (renal) disorder. The pathogenesis of HT in CRF is dominated by volume- and renin-mediated mechanisms. In addition, a wide variety of humoral and neural factors play a role. The HT seen in patients on renal replacement therapy (RRT) and after renal transplantation (Tx) poses special problems. In this paper these various aspects of HT in CRF are discussed and the principles of treatment are reviewed. It has been shown beyond any doubt that control of HT in young patients with CRF and ESRD, treated conservatively or on RRT and after renal Tx is of utmost importance for their long-term outcome. This is an important challenge for all pediatricians looking after young patients with CRF and ESRD.

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.