174 research outputs found
Polarographic analyses of subsarcolemmal and intermyofibrillar mitochondria from rat skeletal and cardiac muscle
No full textWe report the polarographic analysis of subsarcolemmal and intermyofibrillar mitochondria from rat skeletal and cardiac muscle, in order to detect possible biochemical and functional differences. Electron microscopic observation of isolated mitochondria showed normal aspect, with intact membranes. Respiratory control rate with different substrates and state 3 activity did not show differences between subsarcolemmal and intermyofibrillar mitochondria in skeletal muscle and heart
Mitochondrial enzyme deficiency in cerebrotendinous xanthomatosis
No full textWe report reduced respiratory chain enzyme activity in isolated muscle mitochondria and high levels of serum and CSF pyruvate and lactate in a case of cerebrotendinous xanthomatosis. These findings raise the question of the pathogenetic role of mitochondrial dysfunction in this syndrome
Increase of serum levels of vitamin E during human aging: Is it a protective factor against death?
No full textDuring the recent years, numerous reports have focused the attention on the role of vitamin E as a trophic factor in normal function of the nervous system and in protection against aging or other age related pathologies as tumors, Parkinson's disease and several spino-cerebellar syndromes. We have previously reported cases with severe neurological diseases, including peripheral and central pathology due to abnormality of primary symptoms after vitamin E supplementation. Here we report the results of our studies on the changes of serum concentration of vitamin E during development and aging. vitamin E has been measured in the serum of 479 normal subjects from the birth to the age of 106 years, groupped as follows: below 20; 20-40; 40-60; 60-80; 80-100 and above 100 years. The results, show a linear increase of serum vitamin E values (18 mumole/l in the youngest group to 33.2 mumole/l in the centenarians). The data may be related to higher vitamin E intake during aging or to higher adsorption, or to minor catabolism and utilization. In any case, the highest vitamin E availability during aging has been shown and its role in protection against death is discussed
L’endoscopia intraoperatoria in chirurgia esofagea : un valido ausilio nell'approccio mini-invasivo
No full textAnalytic continuation of the critical line: suggestions for QCD
No full textSUMMARY We perform a numerical study of the systematic effects involved in the
determination of the critical line at real baryonic chemical potential by
analytic continuation from results obtained at imaginary chemical potentials.
We present results obtained in theories free of the sign problem, such as
two-color QCD with finite baryonic density and three-color QCD with finite
isospin chemical potential, and comment on general features which could be
relevant also to the continuation of the critical line in real QCD at finite
baryonic density
Patogenesi biochimica della malattia di Leber
No full textPatogenesi biochimica della malattia di Lebe
Headache, seizures and repente strokes in a young subject: a new case of MELAS-like syndrome?
No full textWe report the case of a 21-years-old man affected by fluctuating stroke-like symptoms and computed-tomographic hypodensities, associated with seizures, headache, vomiting and a biochemically abnormal response of blood lactate and pyruvate after an oral glucose load. Muscle biopsy showed an increased number of subsarcolemmal mitochondria of increased size. Mitochondrial enzyme analysis was normal. The diagnosis of a MELAS-like mitochondrial disease even with minor muscle involvement is discussed
Morphometric and biochemical study of muscle mitochondria in adult chronic progressive external ophthalmoplegia
No full textPalpebral ptosis and muscle fatiguability associated with perineurial cell ensheathment of muscle fibers: a new disease of the neuromuscular junction?
No full textPerineurial cell ensheathment of muscle fibers has been reported only in one patient. Here we describe a new case with identical morphologic features and a similar, but milder clinical course characterized by progressive muscle weaknesses and bilateral palpebral ptosis. EMG examination (including repetitive stimulation) and antibodies against acetylcholine receptors were normal. Muscle biopsy revealed several muscle fibers encircled by stratified rings of homogeneous material in which elongated nuclei were visible; this material was positively stained by antibodies directed at epithelial membrane antigen. On ultrastructural examination these encircling-fiber spirals had the characteristics of perineural cells. It is not clear yet whether perineurial cell ensheathment of muscle fibers is an occasional feature, or whether it has a pathogenetic role in the clinical picture of both cases. The perineurial sheaths might alter the correct neuromuscular transmission mimicking a myasthenia-like disease, either by interfering with the neuromuscular junction, or by changing the microenvironment, and, thus, altering the general excitability of the muscle fibers. (C) 1997 Elsevier Science B.V
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