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A Ribes

Publications and source records attributed to A Ribes.

64 records · Page 4Linked to original sources
PubMed1987

A new family affected by the syndrome of hyperornithinaemia, hyperammonaemia and homocitrullinuria.

We have reported three cases of hyperornithinaemia associated with hyperammonaemia and homocitrullinuria (HHH). They deal with two brothers and a sister from a family where the parents and four other children are healthy on clinical and biochemical examination. The biochemical findings in our patients indicate the existence of a defect in the transport of ornithine into the mitochondria. Cultured skin fibroblasts from two of these patients incorporated six times less [14C]ornithine into protein as compared to control cells. The most characteristic sign of the clinical picture is the progressive spastic paraparesis found in one of the cases. Ornithine supplementation and restricted protein intake may be useful in the treatment of this syndrome since after three years of treatment the clinical response was favourable and the patients showed no adverse clinical effects.

Adolescent↗
PubMed1986

[Organic aciduria. Forms of presentation and treatment].

Organic acidurias are congenital errors of the intermediate metabolism caused by a specific metabolic defect which gives rise to an anomalous excretion of carboxilic acids. The majority of these disease appear in the first weeks of life with few specific symptoms as hypotonia, lethargy, coma, seizures, vomits and dehydration. From biochemical point of view the findings of metabolic acidosis, ketosis, and hyperamoniemia are common. Frequently clinical symptoms are precipitated by infectious disease, traumatism or stress situations. The treatment applied in the initial phases may be efficient; for this reason diagnostic and early treatment are necessary for avoid irreversible sequelae. The diagnosis is also important for posterior genetic counseling. Organic acidurias are an interesting field of work for the pediatrician, neuropediatrician, biochemist and dietician to offer new perspectives in the diagnosis and treatment of many congenital errors of the metabolism.

Carboxylic Acids↗
PubMedDate not supplied

An atypical French form of pyruvate carboxylase deficiency.

A further case of pyruvate carboxylase deficiency, French type, with a particular clinical presentation and evolution is described. The initial neonatal symptoms started with respiratory distress, severe metabolic acidosis and a tendency to hypoglycemia. However, the clinical course was not rapidly deteriorating. At the age of 6 months he presented acute neurological symptoms, respiratory difficulty, lactic acidosis and hyperammonemia. Amino and organic acid abnormalities strongly suggested pyruvate carboxylase deficiency, which was confirmed by enzymatic studies in cultured fibroblasts and liver necropsy. Progressive deterioration and bronchopneumonia with cardiac failure and renal insufficiency led to death. Anatomic-pathologic studies revealed periventricular cysts and diffuse hypomyelination. Prenatal diagnosis of a further sibling was performed. The neonatal clinical presentation, biochemical abnormalities, and the presence of periventricular cysts suggested a French phenotype. However, the clinical course was less severe, suggesting a residual enzymatic activity and a possible milder mutation.

Amino Acids↗
PubMedDate not supplied

Polycyclic aromatic hydrocarbons in mountain soils of the subtropical Atlantic.

Surface soil samples from various altitudes on Tenerife Island, ranging from sea level up to 3400 m above mean sea level, were analyzed to study the distribution of 26 polycyclic aromatic hydrocarbons (PAHs) in a remote subtropical area. The stable atmospheric conditions in this island define three vertically stratified layers: marine boundary, trade-wind inversion, and free troposphere. Total PAH concentrations, 1.9 to 6000 microg/kg dry wt., were high when compared with those in tropical areas and in a similar range to those in temperate areas. In the marine boundary layer, fluoranthene (Fla), pyrene (Pyr), benz [a]anthracene (BaA), and chrysene (C + T) were largely dominant. The predominance of Fla over Pyr may reflect photo-oxidative processes during atmospheric transport, although coal combustion inputs cannot be excluded. The PAHs found in higher concentration in the soils from the inversion layer were benzo[b + j]fluoranthene (BbjF) + benzo[k]fluoranthene (BkF) > benzo[e]pyrene (BeP) approximately indeno[1,2, 3-cd]pyrene (Ind) > benzo[a]pyrene (BaP) approximately benzo[ghi]perylene (Bghi) > coronene (Cor) approximately dibenz[a,h]anthracene (Dib), reflecting that high temperatures and insolation prevent the accumulation of PAHs more volatile than BbjF in significant amounts. These climatic conditions involve a process of standardization that prevents the identification of specific PAH sources such as traffic, forest fires, or industrial inputs. Only soils with high total organic carbon (TOC) (e.g., 10-30%) preserve the more volatile compounds such as phenanthrene (Phe), methylphenanthrenes (MPhe), dimethylphenanthrenes (DMPhe), and retene (Ret). However, no relation between PAHs and soil TOC and black carbon (BC) was found. The specific PAH distributions of the free tropospheric region suggest a direct input from pyrolytic processes related to the volcanic emission of gases in Teide.

Altitude↗
PubMedDate not supplied

[Advances in biochemistry in the understanding of neurometabolic disorders].

The progress in the knowledge of neurometabolic diseases is due to the conjunction of innovations in several scientific and technological areas. Our review is focused in the biochemical aspects that we consider should be added systematically in the study of these diseases. 1. Analysis of sialotransferrin isoforms; 2. Analysis of specific acylcarnitines, and 3. Study of purine, pyrimidine and neurotransmitter metabolism.

Biochemical Phenomena↗
PubMedDate not supplied

[The contribution of molecular genetics to hereditary neurometabolic disorders].

In this article we review the main contribution of molecular genetics to understanding hereditary neurometabolic disorders. This includes improvement in diagnosis, especially in X chromosome linked disorders and illness due to the protein or gene expression in tissues which are difficult to obtain. Moreover molecular biology, as a diagnostic tool, has contributed decisively to genetic counselling by permitting firm diagnosis of carriers and prenatal diagnosis. Other important contributions, although more minor, are determination of the prognosis and establishment of individualized treatment based on the genotype. We also review the relation between the disease and the susceptibility allele, the possibility of making genetic population studies and of establishing presymptomatic diagnoses. It is concluded that understanding the molecular basis of a particular disorder has opened the way to diagnosis and prognosis. It also opens the door to genetic therapy, the study of other factors which may affect the action of genes and especially the proteinome.

Alleles↗
PubMedDate not supplied

[In utero macrocephaly as clinical manifestation of glutaric aciduria type I. Report of a novel mutation].

INTRODUCTION: Macrocephaly is a pivotal clinical sign, associated with multiple neurological diseases, particularly neurometabolical ones, such as the glutaric aciduria type I (GA I). This aciduria resulting from the genetical deficiency of the enzyme glutaryl-CoA dehydrogenase (GCDH). Is a relatively common cause of acute metabolic brain damage in early childhood. We report on one case of GA I, with early manifestations since fetal period and a novel mutation. CASE REPORT: Our patient was referred due macrocephaly in utero and occipitofrontal head circumference above the 98 percentile for chronologic age during first few months of life, hypotonia and development delay. The metabolic investigations of organic acids in urine and acylcarnitine profile in blood, the brain magnetic resonance and the molecular analyses of the glutaryl-CoA deshidrogenase gene, confirm the diagnosis. The molecular analysis allowed to identify one previously described mutation A293T and a novel mutation IVS5-2 A>G. CONCLUSION: It is important the recognition of in utero macrocephaly as a sign to early diagnosis of glutaric aciduria type I to initiate specific therapy to prevent the encephalopathic crises and minimize brain damage in patients who are already neurologically impaired.

DNA Mutational Analysis↗
PubMedDate not supplied

[Diagnosis and treatment of brain creatine deficiency syndromes].

AIM: To review the clinical, biochemical and genetic aspects of brain creatine deficiency syndromes, as well as the therapeutic options available. DEVELOPMENT: Brain creatine deficiency syndrome has recently been described as a series of inborn errors of metabolism that affect the synthesis and transport of creatine. Three metabolic defects are known: two affect synthesis -guanidinoacetate methyltransferase (GAMT) and arginine:glycine amidinotransferase (AGAT)- and one affects the transport of creatine. Clinically, these patients can display mental retardation, language disorders, epilepsy, autistic behaviour, neurological impairment and movement disorders. After the clinical selection, the different defects can be identified by a biochemical study involving the analysis of metabolites in biological fluids (guanidinoacetate and creatine/ creatinine ratio). Before continuing with the molecular studies, it is important to confirm the deficiency of brain creatine by means of magnetic resonance imaging with spectroscopy. Diagnostic confirmation of AGAT and GAMT deficits is carried out by determining the enzymatic activity in fibroblasts or lymphoblasts, or the incorporation of creatine in the case of studies of transport defects. The study of mutations in AGAT, GAMT (autosomal recessive inheritance) and SLC6A8 (X-linked) genes completes the diagnosis. CONCLUSIONS: Brain creatine deficiency syndromes are mainly associated to mental retardation and autism. GAMT and AGAT deficiencies respond to treatment with creatine, whereas patients with transport defects do not respond to this therapy; new therapeutic approaches are therefore being evaluated for this disease.

Amidinotransferases↗
PubMedDate not supplied

[Type I glutaric acidity with arachnoidal cysts].

Two sisters are shown who have been diagnosed as having glutaric acidity (GA) type I, in the neuroimage of which bilateral arachnoidal cysts were shown. There is a remarkable lack of correlation between the clinical status of the patients and the arachnoidal cysts. The younger sister developed the first symptoms of her illness at around 5 years of age, whereas the cysts had already been diagnosed at the age of one. It was considered convenient to doubt the diagnosis of type I GA, given the presence of bilateral or familiar arachnoidal cysts, despite the lack of symptoms.

Age of Onset↗