Biomedical subjects

B Mousson

Publications and source records attributed to B Mousson.

41 records · Page 3Linked to original sources

PubMedDate not supplied

Cardiac transplantation in an incomplete Kearns-Sayre syndrome with mitochondrial DNA deletion.

A 38-yr-old man with external ophthalmoplegia, cardiac conduction abnormalities, hearing loss, and ragged-red fibres in skeletal muscle biopsy, developed severe signs of cardiac failure within a few months. Echocardiography and angiography demonstrated a dilated cardiomyopathy. Ubiquinone 140 mg day-1 did not stop the worsening of the cardiac status and cardiac transplantation was performed. Molecular analysis showed a heteroplasmic 4.5 kb mitochondrial DNA deletion in endomyocardial tissue. Eighteen months later, cardiac evolution is good and neurological status is stable.

Adult↗

PubMedDate not supplied

Decreased expression of ubiquinol-cytochrome c reductase subunits in patients exhibiting mitochondrial myopathy with progressive exercise intolerance.

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

[Phosphoribosylpyrophosphate synthetase anomalies in 2 cases of gout beginning at an early age].

On the basis of a study of the action of phosphoribosylpyrophosphate (PRPP) synthetase (EC 2.7.6.1.) in 22 hyperuricemic and 9 normal subjects, the authors report two cases of gout with anomalies of the kinetics of this enzyme. The anomaly consists of an increase in affinity for inorganic phosphate (iP) in the absence of inhibitors, and a decrease in inhibition by low concentrations of ADP in the presence of iP. These patients show no other anomaly of intraerythrocyte PRPP (dosage and production "in vitro"), hypoxanthine-guanine-phosphoribosyl-transferase and APRTase (overall activity and apparent Km). These two cases of gout are characterized clinically by their early occurrence, appearing in one case in a pre-menopausal woman, their family character and their normal sensitivity to allopurinol.

Adenosine Diphosphate↗