Methylation cycle, arginine-creatine pathway and asymmetric dimethylarginine in paediatric renal transplant.

Background: Hyperhomocysteinaemia represents an important cause of morbidity in recipients of renal transplants, but few investigations have been carried out to evaluate the status of the methylation cycle and its relation with levels of new cardiovascular biomarkers, such as asymmetric dimethylarginine (ADMA).

Methods: Twenty-six children and adolescents aged 7-18 years (17 male, 9 female) with stable renal transplants were recruited for the study. None had received treatment with folate, vitamin B(12) or statins.

Persistence of essential fatty acid deficiency in cystic fibrosis despite nutritional therapy.

To study the evolution of plasma fatty acid composition of patients with cystic fibrosis (CF) in relation to nutritional status, pancreatic function, and development of CF-related liver disease (CFRLD) and diabetes mellitus, 24 CF pediatric patients with stable pulmonary disease were studied before and after an approximate period of 8 y. Nutritional status, pulmonary function, pancreatic function, and presence of CFRLD or diabetes mellitus were recorded. Results were compared with data obtained in 83 healthy children.

Fatty acid deficiency profile in children with food allergy managed with elimination diets.

Aim: To evaluate plasma fatty acid (FA) composition of children with food allergy undergoing elimination diets that avoided the offending antigens.

Methods: Twenty-five children (14 male, 11 female) aged 3.8 +/- 1.

The arginine-creatine pathway is disturbed in children and adolescents with renal transplants.

Cardiovascular disease is an important cause of morbidity in recipients of renal transplants. The aim of the present study was to analyze the status of the arginine-creatine pathway in such patients, given the relationship between the arginine metabolism and both renal function and the methionine-homocysteine cycle. Twenty-nine children and adolescents (median age 13, range 6-18 years), who had received a renal allograft 14.

Inherited renal tubulopathies associated with metabolic alkalosis: effects on blood pressure.

Inherited tubular disorders associated with metabolic alkalosis are caused by several gene mutations encoding different tubular transporters responsible for NaCl renal handling. Body volume and renin-angiotensin-aldosterone system status are determined by NaCl reabsorption in the distal nephron. Two common hallmarks in affected individuals: hypokalemia and normal / high blood pressure, support the differential diagnosis.

Arachidonic acid content in adipose tissue is associated with insulin resistance in healthy children.

Background: The fatty acid composition of membrane structural lipids, which is partly dependent on dietary intake, is associated with insulin action.

Aim: To examine the association between fatty acid composition of adipose tissue and skeletal muscle phospholipids with insulin resistance markers in a healthy pediatric population.

Methods: Using a cross-sectional design, we studied 83 healthy children divided into 3 groups, ages 2 to 5, 6 to 10 and more than 10 years.

Essential fatty acid deficiency profile in patients with nephrotic-range proteinuria.

Plasma free fatty acids are bound to albumin, filtered through the glomeruli, and reabsorbed at the proximal nephron. The aim of the present investigation was to determine if urinary loss of fatty acids results in essential fatty acid (EFA) deficiency in patients with nephrotic-range proteinuria. We studied 12 patients aged 9 months to 23 years (eight male, four female) four suffering from congenital nephrotic syndrome (NS) and eight from different renal diseases.

Mutations in the tight-junction gene claudin 19 (CLDN19) are associated with renal magnesium wasting, renal failure, and severe ocular involvement.

Claudins are major components of tight junctions and contribute to the epithelial-barrier function by restricting free diffusion of solutes through the paracellular pathway. We have mapped a new locus for recessive renal magnesium loss on chromosome 1p34.2 and have identified mutations in CLDN19, a member of the claudin multigene family, in patients affected by hypomagnesemia, renal failure, and severe ocular abnormalities.

Autosomal dominant pseudohypoaldosteronism type 1: mechanisms, evidence for neonatal lethality, and phenotypic expression in adults.

Autosomal dominant pseudohypoaldosteronism type 1 (adPHA1) is a rare condition that is characterized by renal resistance to aldosterone, with salt wasting, hyperkalemia, and metabolic acidosis. It is thought of as a mild disorder; affected children's symptoms respond promptly to salt therapy, and treatment is not required after childhood. Mutations in the mineralocorticoid receptor gene (MR) cause adPHA1, but the long-term consequences of MR deficiency in humans are not known.

Osteogenesis imperfecta: anthropometric, skeletal and mineral metabolic effects of long-term intravenous pamidronate therapy.

Background: Administration of bisphosphonates represents a beneficial therapy in children and adolescents with severe osteogenesis imperfecta (OI) because it significantly reduces the annual rate of bone fractures.

Aim: To evaluate the anthropometric, skeletal and mineral metabolic effects of long-term intravenous pamidronate therapy in OI.

Methods: Ten patients, aged 5 mo to 25 y, with OI received cyclical intravenous pamidronate.

Fatty acid composition of skeletal muscle and adipose tissue in Spanish infants and children.

There is a relationship between the fatty acid profile in skeletal muscle phospholipids and peripheral resistance to insulin in adults, but similar data have not been reported in infancy and childhood. The objective of this study was to investigate the fatty acid composition of skeletal muscle and adipose tissue across the paediatric age range. The fatty acid profile of skeletal muscle phospholipids and adipose tissue triacylglycerols was analysed in ninety-three healthy Spanish infants and children distributed into four groups: group 1 (0 to <2 years, n 10); group 2 (2 to <5 years, n 41); group 3 (5 to <10 years, n 24); group 4 (10 to 15 years, n 18).

An analysis of renal tubular acidosis by the Stewart method.

Renal tubular acidosis (RTA) comprises a group of disorders characterized by a low capacity for net acid excretion and persistent hyperchloremic, metabolic acidosis. To investigate the role of chloride, we performed hypotonic (0.45%) saline-loading experiments in 12 children with alkali-treated distal RTA (dRTA) and compared the results with data obtained from 17 healthy control subjects.

Abnormalities in plasma fatty acid composition in human immunodeficiency virus-infected children treated with protease inhibitors.

Aim: To study plasma fatty acid composition in human immunodeficiency virus-infected children treated with protease inhibitors and its relation with other components of the metabolic syndrome observed after this therapy.

Design: Cross-sectional study from collected clinical database.

Subjects: 17 children with HIV infection treated with protease inhibitors.

Bone mineral density and bone turnover in patients with Bartter syndrome.

The aim of this investigation was to evaluate bone mineral density (BMD), by use of DXA, and bone turnover, in patients with Bartter syndrome (BS). Ten patients (2 with BS type II and 8 with BS type III) were included in the procedure. Age at study varied between 2 and 30 years.

A founder mutation in the CLCNKB gene causes Bartter syndrome type III in Spain.

The term "Bartter syndrome" encompasses a group of closely related inherited tubulopathies characterized by markedly reduced NaCl transport by the distal nephron. At present, five different genetic variants have been demonstrated. The majority of patients with so-called classic Bartter syndrome carry inactivating mutations of the CLCNKB gene encoding the basolateral ClC-Kb chloride channel (Bartter syndrome type III).

Long-term renal follow-up of extremely low birth weight infants.

There is evidence that low birth weight caused by intrauterine growth retardation adversely affects normal renal development. Very little information on this issue is available on children born very prematurely. This investigation examined clinical and functional renal parameters in 40 children (23 boys, 17 girls) ranging in age between 6.

Acidosis increases magnesiuria in children with distal renal tubular acidosis.

In experimental animals, metabolic acidosis increases renal magnesium (Mg) excretion, whereas metabolic alkalosis reduces it. The objective of this study was to examine renal magnesium handling (U(Mg)) in children with primary distal renal tubular acidosis (DRTA). We measured U(Mg) in 11 children (3 females, 8 males, aged 6.

Influence of diet on atherogenic risk in children with renal transplants.

Cardiovascular disease is one of the main causes of morbidity and mortality in recipients of renal transplants. Although the risk for cardiovascular disease is in part genetically determined, it may also be influenced by diet. The aim of the present study was to analyze the cross-sectional association of dietary intake of nutrients with biochemical markers of atherogenic risk.

Neonatal hypercalcemia.

The causes of hypercalcemia during the neonatal period are varied. Diagnosis is based on the plasma levels of parathyroid hormone (PTH). (a) PTH in plasma is diminished; exogenous o r endogenous calcium overloading is suspected.

Branchio-oto-renal syndrome.

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by the association of branchial cysts or fistulae, external ear malformation and/or preauricular pits, hearing loss and renal anomalies. Mutations in the EYA1 gene, a human homologue of the drosophila "eyes absent" gene, are identified as the cause of BOR syndrome.

MYH9-related disease: May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are not distinct entities but represent a variable expression of a single illness.

May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are autosomal dominant macrothrombocytopenias distinguished by different combinations of clinical and laboratory signs, such as sensorineural hearing loss, cataract, nephritis, and polymorphonuclear Döhle-like bodies. Mutations in the MYH9 gene encoding for the nonmuscle myosin heavy chain IIA (NMMHC-IIA) have been identified in all these syndromes. To understand the role of the MYH9 mutations, we report the molecular defects in 12 new cases, which together with our previous works represent a cohort of 19 families.

Genetic and metabolic determinants of increased plasma plasminogen activator inhibitor-1 activity in children with renal transplants.

Recent studies have shown that activity of plasminogen activator inhibitor-1 (PAI-1), a prothrombotic protein, may be increased in transplanted patients. The aim of the present investigation was to determine PAI-1 activity in pediatric recipients of renal transplants and to establish the relative contribution of both genetic and metabolic factors. In 29 children and adolescents with stable renal transplants, we related plasma PAI-1 activity to an indicator of inflammatory status [plasma concentration of C-reactive protein (CRP)] and to elements of the insulin resistance syndrome [body mass index (BMI), fasting insulinemia, HOMA index and plasma triglyceride, HDL-cholesterol, apolipoproteins A-1 and B concentrations].

Hyperhomocysteinemia in children with renal transplants.

Many studies have demonstrated a strong association between elevated plasma total homocysteine (tHcys) levels and vascular disease. The aim of the present study was to determine the plasma levels of tHcys in pediatric recipients of renal transplants, to establish possible correlations with renal function, lipid profile, and folate and vitamin B12 status, and to assess whether the C677T and A1298C polymorphisms in the 5, l0-methylenetetrahydrofolate reductase (MTHFR) gene were associated with a particular risk. A total of 26 transplanted children and adolescents were investigated.