The expression of mitochondrial proteins of two patients suffering from myopathy with progressive exercise intolerance and exhibiting a deficiency in the enzymatic activity of complex III (ubiquinol-cytochrome c reductase) has been analyzed by immunological titration. In both patients, the Fe-S protein, the cytochrome b and the 9.5 kDa protein were decreased while the expression of the other complex III subunits were close to normal values. This data indicates that, in some mitochondrial myopathies, proteins of the respiratory chain complexes can be accumulated in mitochondria without being integrated into a functional complex. This may be explained either by a lack of control of the coordination between the synthesis of subunits of mitochondrial and nuclear origin or by a difference in the degradation rate of the various subunits which are not properly assembled.

Adult↗

PubMedDate not supplied

[Diagnosis of muscular intolerance during exercise caused by enzyme deficiency in adults].

The exertional muscle pain syndrome in adults is expressed by recurrent episodes of pain and/or episodes of acute rhabdomyolysis, sometimes with transient myoglobinuria or even acute renal failure. The enzymatic origin of this syndrome is suggested by a familial history, by its usual onset during childhood or adolescence, and by its recurrent attacks usually, but not exclusively, caused by exercise. The aetiological diagnosis, suggested by the clinical context and some dynamic tests, is almost always based on good histological and biochemical examinations of the muscle biopsy.

Adult↗

PubMedDate not supplied

[Mitochondrial cytopathies].

Mitochondrial cytopathies are diseases due to a defect of mitochondrial respiratory chain and are characterized by the presence of morphological abnormalities of mitochondria (ragged red fibers). The clinical manifestations can be polymorphic as various organs may be involved; but in general, these disorders affect either muscle alone (progressive external ophtalmoplegia, myopathy with weakness) or muscle and brain (encephalomyopathies). Some of these diseases may be due to alterations of the mitochondrial genome. Diagnosis can be achieved through the following steps: measurement of lactate, pyruvate and ketone bodies after fasting followed by a carbohydrate rich meal and/or exercise; histological examination and biochemical investigation of a skeletal muscle biopsy; study of possible mitochondrial genome alterations.

Humans↗

PubMedDate not supplied

[Amyloid neuropathy. Ultrastructural study of 2 new cases].

Two familial and sporadic cases of amyloid neuropathy are reported. Nerve biopsies ultrastructural studies permit to involve endothelial and Schwann cells basement membranes into formation of amyloid. This classical notion was worth being recalled and specified. The purpose of amyloid formation is searched in a toxico-metabolic processus possibly in relation with observed demyelinating mechanism. The Schwann cell is at the cross of the cause and of its effect.

Adult↗

PubMedDate not supplied

[Use of local cobalt therapy in peripheral neuropathies associated with chronic lymphopathies (lymphoses). 2 cases with histo-immunologic and ultrastructural records].

In two cases of peripheral neuropathy, associated with a chronic lymphopathy, cobalt therapy to the lower limbs provided considerable relief of pain, with partial motor recovery. The disappearance after cobalt therapy of the lymphoid infiltrate of the peripheral nerve leads to discussion of the pathogeni role of this infiltrate. Immunofluorescent and electron microscopic studies form the basis of a discussion of the mechanism of involvement of the peripheral nerve non-secreting lymphopathies (chronic lymphoid leukaemia) and in secreting lymphopathies (Waldenström's disease).

Aged↗

PubMedDate not supplied