Familial hypercalcemia and hypercalciuria: no mutations in the Ca2+-sensing receptor gene.

A 6-year-old boy presented with persistent hypercalcemia, hypercalciuria and nephrocalcinosis from early infancy. His 40-year-old father also had hypercalcemia and hypercalciuria. In both individuals serum values of intact parathyroid hormone (PTH) were repeatedly normal. Although these findings suggest a functional abnormality of the calcium-sensing receptor (CaR), no mutations in coding regions of the CaR gene could be demonstrated.

[Long-term prognosis of childhood IgA nephropathy in adult life]. / Pronóstico en la vida adulta de la nefropatía IgA diagnosticada en la edad pediátrica.

BACKGROUND: To evaluate long-term prognosis in a group of children with IgA nephropathy and to analyse which clinical factors were associated with progression to chronic renal failure in adulthood. PATIENTS AND METHOD: Retrospective study. 58 young adults with IgA nephropathy diagnosed at 10.6(SD 2.9) years old and studied after a follow-up of 11.8 (SD 2.9) years. RESULTS: Relapses of macroscopic hematuria and proteinuria were the most frequent symptoms at onset (75.9%). In 25.9% of patients high plasmatic IgA levels were also detected. Most cases had grade I (44.8%)or grade II (44.8%) histological lesions at diagnosis. At the last control, clinical remision was observed in 21 patients (36.2%) and 50% of the whole group remained with abnormal urine. 8 patients(13.8%) reached terminal renal failure. Mean renal survival (defined as glomerular filtration rate above 50 ml/min/1.73 m2)was 100, 93.3 and 81.1% at 5, 10 and 15 years of evolution, respectively. CONCLUSIONS: About 14% of children with IgA nephropathy had long-term renal bad prognosis. Hypertension at onset, plasma creatinine elevation and proteinuria during adolescence were significant risk factors associated with chronic renal failure during adulthood. Minimal lesions at IgA nephropathy diagnosis in children did not exclude long-term poor prognosis.

Predictors of final adult height after renal transplantation during childhood: a single-center study.

AIM: Assessment of final adult height and its predictive factors in children transplanted (RTx) and followed up in a single center. METHODS: A cohort of 32 patients (17 boys, 15 girls) who received RTx before the age of 15 years and had reached a final adult height was selected. Twenty patients received a single RTx, 9 patients received two RTx, and 3 patients received three RTx. Seven children were transplanted preemptively, while the remaining 25 children received peritoneal dialysis for relatively short periods of time. In 11 patients, recombinant human growth hormone (rhGH) was administered either before (n = 8) or after (n = 3) RTx. RESULTS: In 13 patiens (41%), the final height standard deviation score for chronological age (hSDS) was -2.3+/-0.5, below the 95% confidence limits for target height (group A), while in 19 patients (59%), it was -0.7+/-0.8, within the 95% confidence limits for target height (group B). The hSDS values at the start of dialysis and at the time of first RTx were significantly lower in group A than in group B. A higher hSDS at the start of dialysis and at the time of first RTx had a significant positive influence on the final height (FH), whereas a longer duration of dialysis had a significant negative effect on the FH. Administration of rhGH after RTx played an important role in the achievement of a normal FH in 3 girls. No differences were observed between group A and B with respect to age at start of dialysis, chronological or bone age at first RTx, number of rejection episodes, duration of the study period from last RTx to FH, glomerular filtration rate during this study period, or percentage of time on prednisone therapy. CONCLUSIONS: The FH is almost exclusively predetermined by the height achieved at the start of dialysis and at the time of first RTx. Therefore, to reach target adult height after RTx, the best strategy is to shorten the time of dialysis and to start rhGH administration at a young age and as early as possible during the course of chronic renal failure. Administration of rhGH after RTx is also highly effective, but, given its potential danger, still remains a matter of investigation.

Direct analysis of milk for aluminium using electrothermal atomic absorption spectrometry.

This work was conducted in order to develop a sensitive, precise method for the direct determination of aluminium in dairy products without sample pre-treatment. For this purpose, various chemical modifiers and thermal programmes for an electrothermal atomic absorption spectrometer were assessed. Different dry and wet sample pre-treatments were investigated in order to test the applicability of the method to the direct determination of aluminium in the matrices. Aluminium adsorption or leaching in various milk storage materials was also investigated. The proposed method allows the determination of aluminium in the range 5-50 micrograms l-1 and a detection limit of 0.32 micrograms l-1 for aluminium. The precision achieved, expressed as the relative standard deviation, was 5.6% for within-run assays (repeatability) and 12.7% for between-run assays (reproducibility). Various types of commercially available milk (skim, low fat and whole) and milkshake (marketed in different packages) were analysed after dilution to 1 + 3 (v/v) with 0.2% HNO3. Processing whole milk for drinking slightly decreases its aluminium content, but heating in aluminium vessels also slightly increases its content. The reliability of the entire procedure was confirmed by an analysis performed on a Standard Reference Material.

Normokalaemic pseudohypoaldosteronism is present in children with acute pyelonephritis.

The present study demonstrates that renal tubular unresponsiveness to aldosterone, without associated hyperkalaemia, is present in children with acute pyelonephritis. We studied 32 children with a diagnosis of acute pyelonephritis established by high fever, flank pain/tenderness, increased blood levels of C-reactive protein and significant Escherichia coli growth in the urine culture. Renal tubular function tests and determinations of plasma renin activity and aldosterone concentration were performed at diagnosis (study 1), after three days of iv gentamycin (study 2) and after 21 days of antibiotic therapy (study 3). Findings were compared to those present in 32 normal children of similar age. Despite normal plasma potassium concentration, fractional potassium excretion and transtubular potassium concentration gradient were significantly decreased in studies 1 and 2, becoming normal in study 3. Decreased renal potassium excretion coexisted with increased values for plasma renin activity and aldosterone concentration. In study 3 these hormones remained elevated only in patients with scarred kidneys. The functional alteration present in acute pyelonephritis may be directly caused by the interstitial inflammation or be mediated by some E. coli endotoxin.