Urinary excretion of endothelin-1 in children with absorptive idiopathic hypercalciuria.

Urinary excretion of endothelin-1 (ET-1) and plasma ET-1 were measured in 21 children with absorptive idiopathic hypercalciuria (AIH) and 22 controls. The absorptive type of idiopathic hypercalciuria was determined by a calcium loading test. Daily urinary excretion of ET-1 and urinary ET-1/creatinine ratio were significantly increased ( P=0.005 and P=0.007, respectively) in patients with AIH (9274+/-6444 pg/24 h and 14.04+/-9.52 pg/mg, respectively) compared with controls (4699+/-2120 pg/24 h and 7.36+/-4.71 pg/mg, respectively). Plasma ET-1 levels were significantly lower in patients with AIH (0.84+/-0.64 pg/ml) than in controls (1.54+/-0.54 pg/ml, P=0.0001). In conclusion, patients with AIH had increased urinary ET-1 excretion and decreased plasma ET-1 levels. This is most likely due to the decreased reabsorption of ET-1 in the renal tubule and increased renal production.

Mesenteric lymphadenopathy as a cause of abdominal pain in children with lobar or segmental pneumonia.

We investigated whether mesenteric lymphadenopathy could be a cause of abdominal pain in children with lobar or segmental pneumonia. The study population consisted of 1)119 consecutive children with lobar pneumonia, older than 4 years of age, and 2) 31 healthy controls. Demographic, clinical, inflammatory, and radiographic data were recorded in all patients. All study subjects underwent abdominal ultrasound, focusing on the identification of mesenteric lymphadenopathy. One month later, a follow-up ultrasound was performed in patients with enlarged mesenteric lymph nodes at the initial examination. Forty patients complaining of abdominal pain were included in group 1, while the remaining 79 were in group 2. The two groups of patients did not significantly differ regarding their demographic, clinical (other than abdominal pain), and radiographic indices. In contrast, enlarged mesenteric lymph nodes with a sagittal diameter of at least 10 mm were identified significantly more commonly in the children of group 1 (P = 0.001). The association of enlarged lymph nodes with the presence of abdominal pain remained significant when the data were analyzed through multiple regression analysis (odds raio, 1.47; 95% confidence interval, 3-44). Enlarged mesenteric lymph nodes were found in a significantly lower ratio of healthy controls (3/31) compared to that observed in group 1 (P = 0.003). In all patients who were followed up, mesenteric lymph nodes had either decreased or were not detectable. Our findings indicate that mesenteric lymphadenopathy might be considered as a mechanism responsible for the development of abdominal pain in a relatively high percentage of children with pneumonia.

The impact of serum lipid levels on circulating soluble adhesion molecules in childhood.

Cell adhesion molecules play a rather important role in the development of atherosclerosis mediating the attachment of monocytes to the endothelium. It has also been well established that hyperlipidemia is a risk factor for atherosclerosis from childhood. The aim of this study was to investigate whether the soluble adhesion molecules correlate with the circulating lipid levels in children. The study population consisted of 107 children (64 boys, 43 girls) aged 6-13 y. Parental history of cardiovascular disease, age, gender, and anthropometric parameters were recorded in all children. Blood samples were obtained from every child following a 12-hour fasting period. Serum triglycerides, total cholesterol, and its fractions as well as plasma levels of P and E selectins and adhesion molecules sVCAM-1 and sICAM-1 were determined. After controlling for age and body mass index, both sVCAM-1 and sP-selectin levels were inversely associated with HDL values (r = -0.33, p = 0.005 and r = -0.39, p = 0.001, respectively). A significant positive correlation was found between sVCAM-1 and triglycerides (r = 0.48, p < 0.001). An increment of 10 mg/dL of HDL corresponds to about 50% reduction of the odds for endothelial dysfunction whereas an increment of 10 mg/dL of triglyceride levels indicates a more than 3-fold excess risk, using either sP-selectin or sVCAM-1 levels as a surrogate for the determination of endothelial dysfunction. We suggest that HDL-C and triglycerides correlate in a biologically plausible way with soluble adhesion molecules, which therefore could be considered as useful indicators of the process of preclinical atherosclerosis even from childhood.

Alkaline phosphatase and its isoenzyme activity for the evaluation of bone metabolism in children receiving anticonvulsant monotherapy.

This study aimed to investigate whether carbamazepine, sodium valproate or phenobarbital as monotherapy in ambulatory epileptic children with adequate sun exposure have some effect on their bone metabolism based on the determination of total serum alkaline phosphatase (AP) levels and its bone isoenzyme activity. Blood samples were obtained from 118 epileptic children (37 on carbamazepine, 47 on sodium valproate and 34 on phenobarbital) and from corresponding healthy controls matched for age, gender and anthropometric parameters. AP and its liver, bone and intestinal isoenzyme levels, other common biochemical markers of bone and liver metabolism and drug levels were measured in the study participants. Patients on carbamazepine or phenobarbital had significantly elevated AP levels accompanied by increased bone and liver isoenzyme activity compared to controls. An increase of bone AP isoenzyme values, correlated with the duration of treatment ( r= 0.49, P= 0.002), was found in children on sodium valproate without, however, a concomitant significant elevation of total AP values. We conclude that children who receive antiepileptic drugs as monotherapy, even when residing in a Mediterranean country with adequate sunlight, may have their bone metabolism affected as indicated by the elevated levels of bone AP isoenzyme. This isoenzyme, but not total AP values, could therefore be used as a marker for the selection of patients who would be benefited by a thorough evaluation of their bone metabolism profile.

Evaluation of E-cadherin/catenin complex in primary and secondary glomerulonephritis.

Catenins (alpha-, beta-, gamma-catenin, p120(ctn)) are cytoplasmic proteins initially identified in a complex with E-cadherin (ECD). The latter belongs to a superfamily of transmembrane glycoproteins important for cell adhesion in normal and disease states. Catenins and p120(ctn), in particular, are substrates for growth factor receptor tyrosine kinases. Cell adhesive mechanisms have an impact on cell migration and proliferation and thus are potentially involved in the pathogenesis of glomerulonephritides (GNs). Using appropriate monoclonal antibodies, we investigated the immunohistochemical expression of ECD, alpha-catenin, beta-catenin, gamma-catenin, and p120(ctn) in renal biopsy specimens from 95 patients with primary GN (n = 51) and secondary lupus-associated GN (n = 44). Examined cases were divided into two groups (proliferative [n = 35] and nonproliferative [n = 60] GNs). Among examined molecules, p120(ctn), beta-catenin, and gamma-catenin were expressed more frequently in glomerular epithelial cells, mainly in parietal epithelium (76%, 48%, and 40%, respectively). p120(ctn) and gamma-catenin epithelial expression appeared to be linked closely with proliferative lupus-associated GNs (P = 0.050 and P = 0.029, respectively). Mainly in lupus GNs, with regard to cellular crescents and epithelial cells around microadhesions to Bowman's capsule, p120(ctn) (63% and 73%, respectively), beta-catenin (72% and 75%), and gamma-catenin (75% and 64%) showed the greatest frequencies of positive detection. Mesangial cells were positive only occasionally for the examined molecules. In proliferative lupus GNs, expression of beta-catenin in mesangial cells tended to be prominent (P = 0.066). ECD and alpha-catenin were not expressed in cellular crescents or microadhesions, whereas only ECD was barely detectable in glomerular epithelial cells. In conclusion, expression of beta-catenin, gamma-catenin, and p120(ctn) is focused on glomerular epithelium, as well as on such lesions deriving from it as cellular crescents. This expression probably is linked with epithelial cells' responses to various mitogens, such as growth factors.

Effects of methylprednisolone pulses on renal function of guinea pigs.

Methylprednisolone produced a dose dependant significant increase in glomerular filtration rate, a significant decrease in sodium excretion, and a significant increase in urinary alkaline phosphatase activity in guinea pigs. The renal histology in groups with 4, 5 and 6 doses revealed mild degenerative changes in the tubular epithelial cells. The results suggest the beneficial effects of methylprednisolone pulse therapy on renal function mainly by increasing glomerular filtration rate with only minimal side effects.