Location of disulfide bonds in mature alpha-L-fucosidase from pea.

Fuc-9 is the mature form of a vacuolar alpha-L-fucosidase enzyme which seems to play an important role in plant growth regulation. Fuc-9 is a 202-residue protein containing five Cys residues located at positions 64, 109, 127, 162 and 169. In this study, the disulfide structure of Fuc-9 was determined by MALDI-TOF mass spectrometry (MS), with minimal clean-up of the samples and at a nanomolar scale.

Large de novo deletion in chromosome 12 affecting the PAH, IGF1, ASCL1, and TRA1 genes.

Phenylketonuria is one of the most common genetic diseases in humans, affecting 1 in 10,000 whites. Deletions are generally uncommon in genes in which no long highly homologous segments are present, and in phenylalanine hydroxylase (PAH) deficiency they represent only 5% of cases. We present the case of a girl affected by classical phenylketonuria who has been screened for mutations in the PAH gene.

Anti-epileptic drug treatment in children: hyperhomocysteinaemia, B-vitamins and the 677C-->T mutation of the methylenetetrahydrofolate reductase gene.

The aim of the study was to observe the influence of carbamazepine and valproic acid on plasma total homocysteine and B-vitamin status and the gene-drug interaction with the 677C-->T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. Plasma total homocysteine concentrations were determined in 136 epileptic children taking anti-epileptic drugs as monotherapy. Nutritional (folate, B12 and B6 vitamins) and genetic (MTHFR 677 C-->T) determinants of plasma homocysteine were studied in a random sample of 59 of the 136 epileptic children.

[Clinical, biomedical , neurological and molecular study of 11 patients with new mutations in PAH gene].

Introduction: PKU is an autosomal recessive disorder. There is a broad spectrum phenotype which depends mainly on residual enzymatic activity and also on other factors such as modifying genes and non-genetic factors. This fact makes us consider that a multidisciplinary study of these patients is necessary to improve knowledge of the condition.

Homocysteine and the MTHFR 677C-->T allele in premature coronary artery disease. Case control and family studies.

Background: The aim of this work was to evaluate the role of homocysteine, and the MTHFR 677C-->T allele as risk factors for premature coronary artery disease and to analyse the inheritance of this metabolic disorder.

Material And Methods: Case-control and family studies were performed in a sample of 76 male patients (age < 55), 95 age-matched controls and 89 patients' offspring. Plasma total homocysteine concentrations, its nutritional determinants and the frequency of the MTHFR 677C-->T allele were measured, in addition to conventional risk factors.

Personal experience with the application of carbohydrate-deficient transferrin (CDT) assays to the detection of congenital disorders of glycosylation.

Congenital disorders of glycosylation (CDG) are genetic multisystemic diseases due to various defects in the biosynthesis or processing of glycoproteins. Our aim is to present our experience in the selective screening of CDG syndrome in a paediatric population (421 patients) with clinical suspicion of the disease, analysing serum carbohydrate-deficient transferrin (CDT) by radioimmunoassay and/or immunoturbidimetry. We established the normal values for our paediatric population.

Diagnostic approach to inborn errors of metabolism in an emergency unit.

Objectives: Our aim was to review the patients with a final diagnosis of inborn error of metabolism (IEM) who had previously required clinical attention at the emergency unit of our hospital over the last 9 years.

Methods: From the 184 patients with IEM, we selected 53 patients who required clinical attention at the EU as a prior step that led to a definitive diagnosis. We analyzed the frequency of the various IEM, their clinical presentations, and basic biochemical abnormalities in decompensation.

[Mitochondrial encephalomyelitis, lactic acidosis and cerebrovascular accidents (MELAS) in pediatric age with the A3243G mutation in the tRNALeu(UUR) gene of mitochondrial DNA].

Objectives: To evaluate three patients with the mitochondrial encephalopathy, lactic acidosis and cerebrovascular accident syndrome (MELAS) diagnosed in childhood, with particular reference to the initial symptoms and clinical evolution during the first stage at a pediatric age, and to compare them with other studies on the subject.

Patients And Methods: Two boys and a girl of 10, 11 and 13 years had tests on lactate, pyruvate and aminoacids in biological fluids under basal conditions and also functional tests and enzyme activity assay of the mitochondrial respiratory chain of a muscle biopsy. We also analysed the particular DNA mutations related to MELAS in different tissues from these patients and in lymphocytes from members of the mothers' families who could be tested.

Oxygen consumption measurement in lymphocytes for the diagnosis of pediatric patients with oxidative phosphorylation diseases.

Objectives: To evaluate the results of oxygen consumption measurement in lymphocytes for the diagnosis and treatment monitoring of pediatric patients with oxidative phosphorylation diseases.

Design And Methods: Twenty-four children with an oxidative phosphorylation disease were studied. Results were compared with those of 87 healthy children.

3-phosphoglycerate dehydrogenase deficiency in a patient with West syndrome.

3-phosphoglycerate dehydrogenase deficiency is a severe but treatable disorder of serine synthesis, first described in 1996 (Jaeken et al. 1996a). The patient presented with West syndrome, severe psychomotor delay, failure to thrive, microcephaly, atypical ocular movements, and pyramidal signs.

Prodigiosin from the supernatant of Serratia marcescens induces apoptosis in haematopoietic cancer cell lines.

The effects of supernatant from the bacterial strain Serratia marcescens 2170 (CS-2170) on the viability of different haematopoietic cancer cell lines (Jurkat, NSO, HL-60 and Ramos) and nonmalignant cells (NIH-3T3 and MDCK) was studied. We examined whether this cytotoxic effect was due to apoptosis, and we purified the molecule responsible for this effect and determined its chemical structure. Using an MTT assay we showed a rapid (4 h) decrease in the number of viable cells.

[Aspects of neuropathy in mitochondrial diseases].

Introduction: The existence of neuropathy has been described in mitochondrial disorders such as MELAS, MERRF, Leigh's syndrome, the Kearns-Saye syndrome, myoneurogastro-intestinal encephalopathy and progressive external ophthalmoplegia and constitutes a basic component of the NARP (neuropathy, ataxia and retinosis pigmentosa). However, the general prevalence of the neuropathy and its characteristics within the mitochondrial encephalopathies is not well understood.

Objectives: To characterize the neuropathy and try to establish a genotype-phenotype correlation.

Imidazolium molecular motifs located on dicationic frameworks. Electrospray mass spectrometric observation of carbenes: imidazolylidenes.

Electrospray ionization mass spectral analysis of simple dicationic imidazolium prototypes (M.2X) is reported and direct observation was obtained for proton-mediated ion-molecule reactions in the gas phase. The comparative ESI-MS study with heterophanes 1a.

[Antiepileptic drugs and carnitine].

Introduction: Carnitine is an nonproteic nitrogenated compound acid present in all mammalian tissue and its principal activity is the long-chain fatty acid transport across the mitochondrial membrane for beta-oxidation.

Development: Carnitine levels are maintained by absorption from dietary, endogenous synthesis in the liver and renal reabsorption. An alteration in concentration could be due to an abnormality in some of mentioned mechanism or to inherited errors in metabolism.

Total homocysteine in patients with type 1 diabetes.

Objective: Our aim was to study the presence of moderate hyperhomocysteinemia, a risk factor for premature cardiovascular disease, its modifying vitamin factors (folates, vitamins B12 and B6), and lipid risk factors in juvenile type 1 diabetes.

Research Design And Methods: A total of 91 patients with type 1 diabetes (46 girls and 45 boys) were studied, with ages ranging from 11 to 18 years, a duration of diabetes from 1 to 15 years, and in pubertal development (stages III, IV, V). In all patients, cholesterol, triglycerides, HDL and LDL cholesterol, lipoprotein(a), folates, cobalamin, vitamin B6, and total homocysteine were determined by specific assays.

Children with stroke: polymorphism of the MTHFR gene, mild hyperhomocysteinemia, and vitamin status.

The aim of this study was to investigate a possible association among the thermolabile polymorphism, nucleotide 677 cytosine to thymidine point mutation (677 C-->T) of the methylenetetrahydrofolate reductase (MTHFR) gene, hyperhomocysteinemia, serum folate, vitamins B12 and B6, and stroke in children. Allele and genotype frequencies for the 677 C-->T polymorphism in 21 children with stroke and 28 healthy children of the same age were studied. No differences in allelic frequency were detected between the two populations.

[Risk factors in cerebrovascular disease in childhood].

Introduction: The etiopathogenesis of cerebrovascular diseases in paediatrics is little known and very varied. Review of the literature gives little practical information about how to investigate a paediatric patient who presents with an acute cerebrovascular illness.

Objectives: To identify the risk factors for cerebrovascular accidents in the paediatric age group in our setting and establish guidelines as to how best to act.

Mutational spectrum of phenylalanine hydroxylase deficiency in the population resident in Catalonia: genotype-phenotype correlation.

Hyperphenylalaninemia (HPA) is a group of diseases characterized by the persistent elevation of phenylalanine levels in tissues and biological fluids. It is an autosomal recessive disorder affecting 1 in 10,000 individuals in Caucasian populations and about 1 in 6,600 in Catalonia. We report the mutational spectrum of phenylalanine hydroxylase deficiency in the population living in Catalonia and the genotype-phenotype correlation.

Decreased serum ubiquinone-10 concentrations in phenylketonuria.

Background: Ubiquinone-10 is a lipid with important metabolic functions that may be decreased in phenylketonuria (PKU) because patients with PKU consume diets restricted in natural proteins.

Objective: We studied serum ubiquinone-10 concentrations in PKU patients.

Design: This was a retrospective, transversal study in which we compared serum ubiquinone-10, plasma cholesterol, plasma tyrosine, and plasma phenylalanine concentrations in 43 PKU patients with concentrations in a reference population (n = 102).

[Ubiquinone: metabolism and functions. Ubiquinone deficiency and its implication in mitochondrial encephalopathies. Treatment with ubiquinone].

Objective: Review of ubiquinone-10 metabolism and functions in humans, focusing its implication in the pathogenesis and physiopathology of mitochondrial encephalomyopathies.

Development: Ubiquinone-10 is an endogenously synthesized lipid with a wide distribution in tissues. Tyrosine and acetil-CoA are involved in ubiquinone biosynthesis.

Identification of a cytogenetic deletion and of four novel mutations (Q69X, I172F, G188V, G197R) affecting the gene for ornithine transcarbamylase (OTC) in Spanish patients with OTC deficiency.

A deletion of at least 11.5 cM in the paternal X chromosome mapping between microsatellites DXS989 and DXS1003 and encompassing the genes for ornithine transcarbamylase (OTC), retinitis pigmentosa GTPase regulator (RPGR) and dystrophin, was associated with the loss of band Xp21 in a female patient with OTC deficiency. Another four female patients were heterozygous for point mutations in the OTC gene: the nonsense mutation Q69X or the missense mutations I172F, G188V and G197R.

Evaluation of hyperhomocysteinaemia in children with stroke.

Hyperhomocysteinaemia is associated with an increased risk of arterial vascular disease and thrombosis in adults. Our aim was to study the association of hyperhomocysteinaemia and stroke in children. Since some patients who had suffered a stroke developed seizures and received treatment with anti-epileptic (antifolate) drugs, we also examined the possible interaction between anti-epileptic drugs and hyperhomocysteinaemia.

Biochemical phenotype and its relationship with genotype in hyperphenylalaninemia heterozygotes.

The molecular detection of heterozygotes for hyperphenylalaninemia is difficult due to the large number of mutations in the PAH gene. For this reason, various indexes that measure plasma concentrations of phenylalanine (Phe) and tyrosine (Tyr), as an expression of Phe metabolizing capacity, have been used for the detection of carriers for mutations in the PAH gene. In this study, we contrast the biochemical and the molecular data in order to know if this is an accurate method.