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Biomedical subjects

U Caruso

Publications and source records attributed to U Caruso.

At least 19 recordsLinked to original sources

Outcome of thiamine treatment in a child with Leigh disease due to thiamine-responsive pyruvate dehydrogenase deficiency.

We describe a child with severe psychomotor retardation, peripheral neuropathy and bilateral abnormal signal in basal ganglia on magnetic resonance imaging, consistent with Leigh disease. Fibroblast pyruvate dehydrogenase assayed with routine method was normal. However, because of neurological improvement after treatment with thiamine, pyruvate dehydrogenase activity was studied again with thiamine pyrophosphate concentration adjusted to the normal human tissue level and found to be deficient. We report here on diagnostic difficulties and clinical follow-up of this patient.

Child↗

3-Methylglutaconic aciduria and hypermethioninaemia in a child with clinical and neuroradiological findings of Leigh disease.

We report on a child with a clinical and neuroradiological picture consistent with Leigh disease and an unusual association of isolated hypermethioninaemia and 3-methylglutaconic aciduria. A low-methionine diet normalized both plasma methionine and urine 3-methylglutaconic acid; a methionine-loading test led to significant increase of both metabolites. In the skin fibroblasts the activity of 3-methylglutaconyl-CoA hydratase was essentially normal. No explanation of this uncommon association of hypermethioninaemia and glutaconic aciduria is available. The possibility of a common transporter for 3-methylglutaconic acid and methionine is an attractive hypothesis.

Amino Acid Metabolism, Inborn Errors↗

Purines and pyrimidines determination in urine using high-performance liquid chromatography.

Single purine and pyrimidine bases are involved in two fundamental metabolic pathways that lead to formation of the building stones of DNA and RNA. Purine and pyrimidine nucleotides are also critically important metabolites in many cellular functions. The main breakdown of purines and pyrimidines produces uric acid and B-minoacids, respectively. Therefore, the study of purine and pyrimidine compounds in body fluid has high clinical relevance. We report, in this work, our experience in purines and pyrimidines determination in urine from children presenting with a clinical picture suggesting an inborn these pathways.

Biomarkers↗

Acyl-CoA:dihydroxyacetonephosphate acyltransferase: cloning of the human cDNA and resolution of the molecular basis in rhizomelic chondrodysplasia punctata type 2.

Rhizomelic chondrodysplasia punctata (RCDP) is a genetic disorder which is clinically characterized by rhizomelic shortening of the upper extremities, typical dysmorphic facial appearance, congenital contractures and severe growth and mental retardation. Patients with RCDP can be subdivided into three subgroups based on biochemical analyses and complementation studies. The largest subgroup contains patients with mutations in the PEX7 gene encoding the PTS2 receptor. This results in multiple peroxisomal abnormalities which includes a deficiency of acyl-CoA:dihydroxyacetonephosphate acyltransferase (DHAPAT), alkyl-dihydroxyacetonephosphate synthase (alkyl-DHAP synthase), peroxisomal 3-ketoacyl-CoA thiolase and phytanoyl-CoA hydroxylase, although there are differences in the extent of the deficiencies observed. Patients in the two other subgroups have been reported to be either deficient in the activity of DHAPAT (RCDP type 2) or alkyl-DHAP synthase (RCDP type 3) while no other abnormalities could be observed. To examine whether the gene encoding DHAPAT is mutated in patients with RCDP type 2, we determined the N-terminal amino acid sequence of the enzyme isolated from human placenta. Using this sequence as a query, we identified a 2040 bp open reading frame (ORF) in the human database of expressed sequence tags. Expression of this ORF in the yeast Saccharomyces cerevisiae showed that we have identified the DHAPAT cDNA. The deduced amino acid sequence revealed no PTS2 consensus sequence. In contrast DHAPAT appears to contain a putative PTS1 at the extreme C-terminus. All RCDP type 2 patients analyzed were found to contain mutations in their DHAPAT cDNA. This demonstrates that RCDP type 2 is the result of mutations in DHAPAT.

Acyltransferases↗

An electrogenic amino acid transporter in the apical membrane of cultured human bronchial epithelial cells.

We performed Ussing chamber experiments on cultured human bronchial epithelial cells to look for the presence of electrogenic dibasic amino acid transport. Apical but not basolateral L-arginine (10-1, 000 microM) increased the short-circuit current. Maximal effect and EC50 were approximately 3.5 microA/cm2 and 80 microM, respectively, in cells from normal subjects and cystic fibrosis patients. The involvement of nitric oxide was ruled out because a nitric oxide synthase inhibitor (NG-nitro-L-arginine methyl ester) did not decrease the arginine-dependent current. Apical L-lysine, L-alanine, and L-proline, but not aspartic acid, were also effective in increasing the short-circuit current, with EC50 values ranging from 26 to 971 microM. Experiments performed with radiolabeled arginine demonstrated the presence of an Na+-dependent concentrative transporter on the apical membrane of bronchial cells. This transporter could be important in vivo to maintain a low amino acid concentration in the fluid covering the airway surface.

Alanine↗

Spherophakia associated with molybdenum cofactor deficiency.

Molybdenum cofactor deficiency is an autosomal recessive disorder characterized by lack of activity of the enzymes sulfite oxidase, aldehyde oxidase, and xanthine dehydrogenase or oxidase. The clinical manifestations are indistinguishable from those of isolated sulfite oxidase deficiency: craniofacial alterations, intractable neonatal convulsions, very severe mental retardation, lens dislocation, and death in the first decade of life. Lens dislocation is found in nearly all patients after neonatal age. In the present case it developed late (at the age of 8 years) and was preceded by bilateral spherophakia. We hypothesize that an abnormal relaxation of the zonular fibers is the cause of spherophakia in this disease; this causes lens dislocation eventually, after days, months, or years.

Child↗

Severe complex I deficiency in a case of neonatal-onset lactic acidosis and fatal liver failure.

We report a newborn admitted to our service on the 2nd day of life because of hypotonia and metabolic acidosis. A progressive hepatocellular dysfunction dominated the clinical picture and the patient died at 13 months of age because of severe hepatic failure. Persistent lactic acidosis, high ketone bodies levels and high-normal lactate/pyruvate and 3-hydroxybutyrate/acetoacetate molar ratios in plasma were found. Investigation of a liver biopsy revealed low activities of all the mitochondrial respiratory chain enzymes but in particular a marked decrease of complex I (NADH cytochrome c reductase) activity. All respiratory chain enzyme activities were normal in cultured skin fibroblasts. Mitochondrial DNA analysis failed to detect any major rearrangements. Although only a few cases have been reported so far, it is becoming clear that liver should be considered as one of the organs involved in oxidative phosphorylation disorders. The finding of unexplained progressive liver failure with poor neurological conditions, lactic acidaemia and ketonuria strongly warrants investigation for a respiratory chain disorder. Moreover, the finding of normal respiratory enzyme activities in a tissue other than liver does not rule out the existence of an oxidative phosphorylation disorder in patients with hepatocellular disease of unexplained origin.

Acidosis, Lactic↗

Tyrosinemia type III: diagnosis and ten-year follow-up.

Tyrosinemia type III, caused by deficiency of 4-hydroxyphenylpyruvate dioxygenase, is a rare disorder of tyrosine catabolism. Primary 4-hydroxyphenylpyruvate dioxygenase deficiency has been described in only three patients. The biochemical phenotype shows hypertyrosinemia and elevated urinary excretion of 4-hydroxyphenyl derivatives. We report the clinical and biochemical findings and the results of long-term follow-up in a new patient with this disorder presenting with severe mental retardation and neurological abnormalities. The clinical phenotype is compared with those reported in the three previously described patients.

4-Hydroxyphenylpyruvate Dioxygenase↗

[Cancer in the elderly. Clinico-epidemiologic considerations].

The elderly population is rapidly increasing in Western countries. Old age indirectly represents one of the most important risk factors for the development of neoplasias. In Italy in 1991 a total of 14,572 deaths from tumours were recorded, equivalent to 27% of all deaths; of these over 66% affected individuals aged over 65 years old. In the 65-74 age bracket mortality caused by tumour is the prime cause of death in Italy and is undergoing an exponential increase over time. The most frequently found tumours and above all the cause of the greatest number of deaths in the elderly population are lung cancer, prostate cancer, breast cancer, colorectal cancer, stomach cancer. To date the only weapon that has proved efficacious in some tumours (breast, colon-rectal, prostate, melanoma) is early diagnosis through screening and adequate treatment. The elderly are an extremely heterogeneous population and it is therefore not easy to provide guidelines that are applicable to the entire population. Firstly, it is important to provide more information in order to permit effective and targeted prevention. In order to fulfil this objective, structures offering the necessary equipment and skills will have to be create; training must be provided for personnel in this type of preventive medicine; lastly, the awareness of doctors towards this type of medicine must be increased by providing the correct information.

Aged↗

[Nonpalpable lesions of breast carcinoma in elderly patients].

Breast cancer is the most frequent form of tumour in women. The only weapon at our disposal to reduce the mortality rate for breast cancer is early diagnosis. A number of studies have shown, using appropriate prevention programmes, an increasing number of minimum 20-30% lesions. The probability that a non-palpable lesion is malignant increases with age, with a positivity of 37-39% is women aged over 50. Localisation using FNAB requires studies with greater statistical value so that it can be inserted in current prevention programmes, given that the percentage of false negative is > 8%. At present, excisional biopsy with bioptic tests continues to be the standard reference method for the diagnosis of non-palpable lesions; this diagnostic procedure allows the lesion to be removed in positive cases, and avoids re-operating as in the case of suspected or inadequate cytological tests.

Aged↗

[The surgical therapy of prostatic tumors].

In this paper the authors review the latest international literature regarding prostate tumour surgery, comparing surgery with the so-called "wait and see" approach. Together with hormone treatment, the latter method has been used by many researchers over the past few years given the low mortality caused by this tumour in spite of the increasing number of cases diagnosed. The wait-and-see approach is now rendered controversial by improved diagnostic methods and the widespread introduction of early diagnosis programmes. The authors report a number of studies on the use of "wait-and-see" in relation to radical prostatectomy and compare the results of the two techniques in terms of morbidity, mortality and survival. They go on to describe the various types of surgical technique used and their respective pros and cons as well as the complications typical of each technique. In conclusion, the authors discuss the indications for radical prostatectomy which, if performed in selected patients, appears to be a promising therapeutic approach in terms of disease-free survival and with a low operating mortality with complications that are not impossible to resolve using appropriate treatment.

Humans↗

Simple analysis of plasmalogens in erythrocytes using gas chromatography/mass spectrometry with selected-ion monitoring acquisition.

Plasmalogens are a unique class of ether-phospholipids whose role, even though not fully defined, is essential. Their biosynthesis starts in peroxisomes, therefore, plasmalogen analysis is fundamental in the study of peroxisomal disorders. The present work reports a simple method for plasmalogen determination in erythrocytes for use in the study of peroxisomal disorders in humans; the procedure is based on two other methods that have previously been reported and employs GC/MS for separation and detection.

Acetals↗