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Biomedical subjects

B M Gekht

Publications and source records attributed to B M Gekht.

At least 55 records · Page 3Linked to original sources
PubMed1983

[Terminal polineuropathy (independent clinical syndrome or variant course of myasthenia)].

The clinical data and findings of thorough electrophysiological and morphohistochemical examinations of the muscles of 13 patients with the myasthenic syndrome associated with terminal polyneuropathy are presented. Correlation of the clinical and electrophysiological data to the clinical manifestations of the disease and the magnitude of the block of the neuromuscular transmission disclosed a number of characteristic features of the clinical course of the disease (a predominantly oculodistal type of damage, a diminution or the absence of tendon and periosteal reflexes, the presence of atrophies of distal muscular groups) and of the EMG pattern (the presence of enlarged PDDE, an increase in residual latency, the inverse ratio of the decrement of electric and mechanical responses upon indirect stimulation of the muscle at a frequency of 3/sec) and in the histochemical picture (the presence of groupings of type I and II muscular fibrils, which are not characteristic of myasthenia). On the basis of the evidence obtained, a conclusion is drawn that the described syndrome is an independent clinical form rather than a myasthenia variant.

Adenosine Triphosphatases↗
PubMed1983

[Phenomenon of active reorganization of the architectonics (structure) of motor units].

The density of muscle fibers in a motor unit (MU) was studied electromyographically with the aid of a microelectrode. Muscle biopsy specimens withdrawn from patients with different neuromuscular diseases were subjected to morphological and histochemical studies. During denervation-reinnervation processes, the motoneuron actively reconstitutes the structure of an innervated MU. Apart from branching in the central part, the motoneuron excludes from the innervation zone the muscle fibers located in the most remote areas in respect of the MU center.

Action Potentials↗
PubMed1982

[Differential evaluation of excitatory conduction rats along different segments of motor nerves and functional tests in the diagnosis of diseases of the human peripheral neuromotor apparatus].

In 61 patients with neurono- and neuropathies and affections of the synaptic apparatus and the muscular matter of various etiology, the state of the peripheral nerves was examined. It was found that various forms of the pathology are characterized by specific changes in the speed of the stimulus transmission along various parts of motor nerves. The changes of the functional state can be seen especially clearly on comparing the speed of the stimulus transmission along the proximal and the distal parts of a peripheral nerve (the difference being named "transmission speed gradient"). In neuronopathies the transmission speed changes are prevailing in the proximal, in neuropathies in the distal, and in synaptic structure abnormalities in the extreme distal parts of the nerve. A 15-minute artificial ischemia of the nerve (a functional test) led to characteristic changes of the transmission speed, these changes correlating with the process stage. In cases of mild changes of the transmission speed the nerve was more sensitive, while in cases of pronounced changes more resistant to the ischemia. It was shown that the transmission speed changes in ischemia manifested themselves along the whole nerve, but not only in the site of its affection. In cases of the carpal canal syndrome the ischemia-induced lowering of the transmission speed in the nerve distal part was extremely sharp.

Diagnosis, Differential↗
PubMed1981

[Electromyographic and morphological analysis of the changes in the motor units in myasthenia, combined myasthenia with thymoma and polymyositis and terminal polyneuropathy with myasthenic syndrome].

Changes of the activity potentials of motor units and muscular fibres registered with the aid of needle electrodes are compared with the results of morphological examinations of biopsy specimens of 1,096 muscles taken from 137 patients with myasthenia, combinations of myasthenia with thymoma and polymyositis, as well as from patients with terminal polyneuropathy with the myasthenic syndrome. It has been shown that characteristic of myasthenia are differentiated changes of the motor unit activity potentials: in half of the muscles examined the parameters of those potentials were found to be normal, no polyphasic or protracted potentials were observed. In the patient with combinations of myasthenia with thymoma, polymyositis, and in terminal polyneuropathy with the myasthenic syndrome pronounced changes of all the activity potentials of the motor units were observed in the form of both a sharp shortening and a prolongation of their duration; a great number of polyphasic potentials was registered and spontaneous activity of various degree was observed. Morphological examinations of 55 biopsy specimens of the muscles of the same patients revealed a correlation between the degree of the dystrophic and atrophic changes of the muscular fibres and depth of the affection as determined on the basis of electromyographic findings.

Action Potentials↗
PubMed1980

[Clinical aspects of the pathology of neuromuscular transmission].

On the basis of analyzing clinical reports, the results of the author's own studies, and respective information published in literature, principal problems concerning the clinical course, the mechanism of development, the methods of treatment and organization of the therapeutic and prophylactic aid to patients with neuromuscular transmission pathologies are discussed. The main myasthenic syndromes, as well as problems of myasthenia differential diagnosis are described. A question on the role of autoimmune disturbances in the formation of muscular disturbances in cases of a neuromuscular transmission pathology is raised. Data characterizing the role of anticholinesterase drugs, hormones, surgical and radiotherapeutic methods in the treatment of myasthenia and myasthenic disturbances are presented.

Acetylcholinesterase↗
PubMed1980

[Electromyography using needle electrodes to analyze the structure and functional state of motor units in neuromuscular diseases].

Results of electromyographic examinations of over 1,000 patients with various forms of acute and chronic neuromuscular diseases and progressing myodystrophies are analyzed. The examinations were carried out with the use of needle electrodes. On comparing the electromyographic findings with the clinical ones and with the results of examining muscle biopsy specimens 5 electromyographic stages of motor unit changes occurring in the course of the development and compensation of the pathological process were differentiated. Stage I was characterized by a shortening of the duration of the activity potentials in some motor units, with the average duration of the motor unit activity potentials remaining unchanged. In Stage II the average duration of the motor unit activity potentials, due to a considerable shortening of most of them, diminishes by more than 20%. In Stage III, along with the short-duration potentials there appear much longer potentials with a duration exceeding the normal ones. Characteristic for Stages IV and V was prevalence of long motor unit activity potentials the average duration of which was by 20 to 40% greater than that of the normal ones. Data characterizing the degree of the spontaneous activity of muscular fibres (potentials of fibrillations and positive acute waves), as well as the spontaneous activity of the motor units (fasciculations) in various stages of their impairment are presented. The importance of evaluating the motor unit activity potentials and the spontaneous activity of the muscular fibres for diagnosing and studying the mechanisms of the development of neuromuscular diseases is discussed.

Action Potentials↗
PubMed1979

[Pathogenetic therapy of nervous system and muscular diseases using large doses of prednisolone on alternate days].

A total of 230 patients with myasthenia, polymositis, disseminated sclerosis and myeloradiculopolyneuronitis were administered high doses of prednisolone (up to 100 mg) every other day. The treatment efficacy and low incidence of side effects and complications are emphasized. High doses of prednisolone given every other day do not inhibit secretions of endogenic ACTH and cortisol. The immunodepressant effect of the drug remains unchanged.

Adolescent↗
PubMed1978

[Effect of hormonal therapy on the level of antibiodies to antigens of thymus epithelial tissue in myasthenia].

With the aid of an indirect method of immunofluorenscence in the process of a study of 65 blood sera of patients with myasthenia, the authors, demonstrated significant prevalence of antibodies titres to myoid cells and to an epithelial thymus reticulum (especialey in patients with thymomas) in comparison with normals. These data my indicate an autoimmune character of myasthenia. A positive effect of hormonal therapy was accompanied by a distinct drop in the level of antibodies in patients with myasthenia which permits to assume a certain connection between hormonotherapy and its influence on the autoimmune processes.

Anabolic Agents↗