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Biomedical subjects

C Minetti

Publications and source records attributed to C Minetti.

At least 73 records · Page 4Linked to original sources

Dystrophin deficiency in young girls with sporadic myopathy and normal karyotype.

We studied dystrophin in three young girls with a sporadic myopathy of early onset, manifested by mild to severe limb weakness, calf hypertrophy, high serum creatine kinase, normal karyotype, and morphologic features in muscle consistent with muscular dystrophy. DNA analysis did not reveal a deletion of the dystrophin gene. Immunohistochemical studies of dystrophin in muscle biopsies showed a mosaic of fibers with and without dystrophin, and immunoblot analysis showed partial dystrophin deficiency in all three patients, more severe in the patient with the highest proportion of dystrophin-deficient fibers. These observations suggest that the patients are Duchenne muscular dystrophy carriers. The data also support the concept that uneven lyonization in muscle is responsible for the clinical myopathy in these patients. We suggest that any girl with sporadic proximal limb weakness should be evaluated as a possible Duchenne carrier by dystrophin studies.

Child↗

[Infantile dermatomyositis. Clinical aspects and prospective treatments].

Juvenile dermatomyositis (DMI) is a rare illness of multisystem inflammatory disease of unknown etiology. It is usually considered as a part of the spectrum of polymyositis/dermatomyositis (PM/DM), and is distinguished from the adult form in having a number of different clinical features as well as distinctive pathologic findings. Although the clinical findings and course of the disease, laboratory evaluation and therapy have been reviewed, many of these studies are old and may not accurately reflect the current status of the disease as it is now defined and treated. Generally it is first diagnosed by the appearance of typical signs in both the skin and muscles. The clinical picture shows early signs of heterogeneity and is confirmed by these latter developments. Its classification falls into three groups: acute single cycle, chronic polycycle and continued chronic; this sickness invariably evolves into one or another of these three. Our current work involves 15 cases of DMI; 8 have acute monocycle, 4 chronic polycycle and 3 continued chronic. This illustrates the clinical and biological heterogenousness of this illness which in itself presents extreme difficulties when considering possible treatment. From our experience, high dose of corticosteroida intraveins have had the best result. Where cases have been acute at the beginning of the sickness and where there has been complications, particularly those of a bronco-pulmonary nature (we treated 3 such cases) it has proven to be beneficial to use corticosteroid together with the immunosuppresant: ciclofosfamide. The use of ciclosporina in one case who had resisted other forms of therapy has appeared to be effective, though this has yet to be verified.

Acute Disease↗

Mitochondrial encephalomyopathies.

The mitochondrial diseases present with great heterogeneity. They are often multisystemic and vary considerably in age at onset, distribution of weakness, severity, and course. Only nonthyroidal hypermetabolism has a distinctive clinical presentation. Therefore, attempts at classification have generated some controversy. This article discusses the general classification that takes into account genetic and biochemical features, which has resulted from the fast pace of biochemical and molecular genetic investigations.

Brain↗

A case of congenital neuromuscular disease with uniform type I fibers, abnormal mitochondrial network and jagged Z-line.

Histological, histochemical and ultrastructural studies of muscle biopsy in a case of congenital neuromuscular disease revealed unusual findings consisting of muscle fibers uniformity which were all type I and of small diameter, jagged Z-line and abnormally developed transverse network of mitochondria. E.M.G. examination demonstrated a myopathic pattern, but mitochondrial changes are quite different from those reported in mitochondrial myopathies and jagged Z-line seems poorly correlated with Z-line streaming present in denervation atrophy, target fibers, core-like lesions or other Z-line abnormalities of the nemaline myopathy. On the other hand type I histochemical uniformity seems more likely related to some dysfunction of the neuronal mechanisms that control both the fiber type differentiation and other trophic influences. It also suggests that myogenic E.M.G. pattern might actually be pseudo-myopathic and due to a reduction of the cross sectional area of the individual muscle fibers composing the motor unit.

Biopsy↗

Familial nemaline myopathy.

Two sisters with congenital nemaline myopathy are described. In both cases almost 70% of muscle fibers contained rods which were selectively localized in the larger ones. The variability coefficient was abnormally increased. Histochemical reactions showed that almost all the muscle fibers were type 1. In one case many fibers contained one or more core-like lesions. The parents and two siblings of the patients were clinically normal; EMG examination also showed normal motor unit potentials. Muscle biopsy was normal in the father; in the mother a slight type 1 predominance was detected without rods or other signs of myopathy. The disease seems to be transmitted by an autosomal recessive trait, although incomplete penetrance of a dominant trait cannot be excluded.

Biopsy↗