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Biomedical subjects

E Valle

Publications and source records attributed to E Valle.

At least 55 records · Page 3Linked to original sources
PubMed1982

Subcellular localization of phosphoenolpyruvate carboxykinase in the trypanosomatids Trypanosoma cruzi and Crithidia fasciculata.

Particulate fractions obtained from Trypanosoma cruzi and Crithidia fasciculata by different procedures were subjected to isopycnic centrifugation in sucrose gradients, in order to determine the subcellular localization of phosphoenolpyruvate carboxykinase (PEPCK) in both organisms, and of malic enzyme (ME) I in T. cruzi. The more clear-cut results were obtained with T. cruzi by breaking the cells by grinding in a mortar with silicon carbide and using a gradient from 0.4 to 2.0 M sucrose, whereas with C. fasciculata, the best procedure was disruption of the cells by digitonin treatment and potter homogenization and use of a gradient from 1.1 to 2.0 M sucrose. PEPCK banded together with the glycosomal marker hexokinase in both organisms; there was a clear separation from the mitochondrial markers, oligomycin-sensitive Mg2+-APTase and citrate synthase. PEPCK showed a latency of 24% in the enriched 'glycosoma' fraction of T. cruzi. ME I from T. cruzi, on the other hand, banded together with the mitochondrial markers. These results indicate that PEPCK and ME are present in different subcellular compartments, a fact significant for the prevention of a futile cycle between C4-dicarboxylic acids and C3-monocarboxylic acids, which might take place if both enzymes functioned in the same compartment.

Animals↗
PubMed1980

Intracellular distribution of carbon dioxide-fixing enzymes in Trypanosoma cruzi and Crithidia fasciculata.

The intracellular distribution of phosphoenopyruvate carboxykinase (EC 4.1.1.49) and NADP-linked malic enzyme (EC 1.1.1.40) activity in epimastigotes of Trypanosoma cruzi (Tulahuén strain) and in Crithidia fasciculata has been studied by two procedures: (i) subcellular fractionation by differential centrifugation of homogenates obtained by breaking the cells in a mortar; (ii) selective disruption of cellular membranes by digitonin treatment. Phosphoenolpyruvate carboxykinase is particulate in both organisms, as is one of the two forms of malic enzyme present in T. cruzi (malic enzyme I), whereas the other malic enzyme of T. cruzi (malic enzyme II) and the single malic enzyme of C. fasciculata are in the cytosol.

Citrate (si)-Synthase↗
PubMed1973

Antibodies against human types A and B influenzaviruses in the sera of animals in Spain.

Sera from several animal species were subjected to serological tests for antibodies against types A and B influenzaviruses of human origin. Of the swine sera, 13% were positive by the haemagglutination-inhibition test for the human A strain and, of those, 68% were also positive by the neuraminidase-inhibition test. None of the sera tested was positive for the B strain.

Animal Population Groups↗
PubMedDate not supplied

Visceral leishmaniasis and other severe infections in an adult patient with p47-phox-deficient chronic granulomatous disease.

We report a rare case of a male patient without known immunodeficiency consecutively diagnosed with visceral leishmaniasis, brain abscess and cavitating pneumonia in the 3rd decade of life. Chronic granulomatous disease (CGD) was diagnosed by a nitroblue tetrazolium test. A p47-phox mutation of the NADPH oxidase of the leukocytes was suspected by immunoblotting and confirmed by DNA analysis. The patient was homozygous for this mutation while his mother and sister were heterozygous asymptomatic carriers. After the CGD diagnosis the patient started a chronic prophylactic regimen with subcutaneous interferon-gamma (0.05 mg/m2 of body surface/three times a week), and oral trimethoprim-sulfamethoxazole and itraconazole (both at 5 mg/kg/day) with no subsequent infections after 12 months of follow-up.

Adult↗
PubMedDate not supplied

Early complications in type 1 diabetes: central nervous system alterations preceded kidney abnormalities.

Abnormalities of the central nervous system (CNS), as discerned by neuroelectrophysiological studies, and an impaired, charge-related, differential filtration of protein at kidney level as evaluated by selective protein clearance, have recently been shown in diabetes of short duration and without any apparent complication. In order to explore the time of appearance and possible correlations, CNS and kidney abnormalities have been evaluated in parallel both in short-term and long-standing type 1 diabetic subjects. Two groups of patients were studied: Group 1 (no. 15), with no previously known clinical sign of complications and less than 5 years from diagnosis; Group 2 (no. 15) with more than 10 years of disease and with or without clinical signs of diabetic complications. Twenty age and sex comparable normal subjects were included in the study (Group 3). Short-latency multimodal evoked potentials (visual-VEP, brainstem auditory-BAEP, median and tibial somatosensory m- and t-SEP) and charge and/or size selective protein clearances (albumin, anionic immunoglobulins, neutral/cationic immunoglobulins) were evaluated. In Group 1, 27% of patients showed neurophysiological abnormalities (P < 0.05 vs. Group 3) while one showed proteinuria. In Group 2, 60% of patients showed electrophysiological changes (P < 0.0001 vs. Group 3) while 67% showed abnormal charge or size selective proteinuria (P < 0.0001 vs. controls) with a significant association between the abnormalities of CNS and of charge selective proteinuria (P < 0.05). Thus, CNS abnormalities may be detected even in patients with diabetes of short duration and are later associated with subclinical kidney abnormalities. These findings stress the value of the multimodal evoked potential evaluation as a sensitive and early diagnostic approach to the study of diabetic complications.

Adult↗
PubMedDate not supplied

Monitoring of somatosensory evoked potentials in cerebral ischemia: an experimental model.

We have studied Mongolian gerbils using somatosensory evoked potentials (SEP) recordings before, during and after an ischemic event. In six experimental animals, cerebral ischemia was reproduced by clamping both carotid arteries for ten minutes. Two recordings were made during this period at 4' and 8'. An additional four recordings were made after removal of the clamp at 4', 8', 12' and 20'. Four animals were utilized as a control group, and were subjected to the identical experimental protocol, with the exclusion of carotid artery clamping. During ischemia we observed an evident alteration of the SEP recordings in the experimental animals, and a more or less rapid recovery during the post-ischemic period. This experimental model may be useful for the monitoring and the evaluation of the evolution of cerebro-vascular damage during the post-ischemic period.

Animals↗
PubMedDate not supplied

[Dopaminergic receptors].

The functions of multiple brain dopamine receptors are discussed in relation to the physiological role of dopamine in CNS.

Central Nervous System↗
PubMedDate not supplied

Brainstem auditory evoked potentials in toxic, metabolic and anoxic coma.

The aim of this study was to evaluate the efficacy of brainstem auditory evoked responses as a prognostic tool in conditions of coma which interfere with cerebral metabolism. Thirteen patients in coma resulting from different systemic disorders (barbiturate intoxication, cardiac arrest, chronic hepatic insufficiency) were included in the study. Brainstem auditory evoked potentials were recorded and patients were graded according to the results. When used in conjunction with other clinical parameters (Glasgow Coma Scale), brainstem auditory evoked potentials provided a more reliable prognostic tool than the traditional EEG exam alone. A good correlation was found between electrophysiological data and clinical outcome not only in barbiturate (toxic) coma, but also in hepatic (metabolic) coma. Of particular significance was the disappearance of the components which follow wave III (grade 2), leading to a fatal outcome in all three patients in hepatic coma.

Adult↗
PubMedDate not supplied

[Longitudinal study of evoked responses (VEP, BAEP, SSEP) in multiple sclerosis].

The Authors have examined 20 subjects affected by "possible" multiple sclerosis by means of a multimodal (VEP, BAEP, SEP) electrophysiologically evaluation longitudinally conducted during a time period of 1 year. The electrophysiological data obtained are related to the clinical picture, the disease's evolution, and to the adopted pharmacological therapy, in order to attempt a more precise diagnostic and prognostic assessment of these patients.

Adult↗
PubMedDate not supplied

Multimodal evoked potentials and CSF findings in the diagnosis of multiple sclerosis.

A group of 30 patients classified on clinical grounds as having definite (N = 16) or probable MS (N = 14) according to McAlpine's criteria, has been studied using multimodal recordings of evoked potentials (visual, auditory, and somatosensory) and examination of the cerebrospinal fluid (CSF) for oligoclonal bands and Link's Index. Evoked potentials examination proved extremely sensitive in discovering asymptomatic lesions of the central nervous system. CSF data, in particular the presence of oligoclonal bands, had a high sensitivity for MS. According to these electrophysiologic and immunologic results, we have reclassified our patients in conformity with the diagnostic criteria proposed by Bartel. The combination of electrophysiological and CSF data, together with common clinical criteria, led to greater diagnostic accuracy, making it possible to reclassify most patients previously considered to have probable MS as having definite MS.

Adult↗
PubMedDate not supplied

[Syringomyelia. Clinical and neurophysiologic correlations (SEP) as a function of surgical treatment].

The authors have studied the somatosensory evoked potential (SEP) behavior following stimulation of upper and lower limbs in two subjects affected by syringomyelia. The patients were evaluated electrophysiologically before and after decompressive surgical treatment. The findings indicate a positive correlation between the SEP recordings and the role of CSF pressure in the central nervous system.

Adult↗