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Biomedical subjects

V M Kazakov

Publications and source records attributed to V M Kazakov.

At least 19 recordsLinked to original sources
PubMed2006

[Lower motor neuron diseases with predominantly upper limbs affection: are they independent forms or atypical variants of amyotrophic lateral sclerosis?].

We carried out an analysis of 5 sporadic cases of lower motor neuron disease with predominant affection of the proximal parts of arms in 2 patients and distal parts in 3 patients. From clinical point of view, our own observations, along with similar cases reported in the literature with predominantly affected upper limbs, different progression of the disease and denervation changes during needle EMG, can argue for clinical heterogeneity of lower motor neuron disease. There were some difficulties in establishment of a differential diagnosis between atypical variants of amyotrophic lateral sclerosis ("flail arm" syndrome) and primary muscular atrophy of adults at the early stages of the disease. We suppose that atypical variants of amyotrophic lateral sclerosis resultant from affection of lower motor neuron only ("flail arm" syndrome and distal amyotrophy), could be distinguished from amyotrophic lateral sclerosis and considered as an independent entity.

Adolescent↗
PubMed2004

[A new method of analysis of impulse activity in brain neurons].

Investigation of impulse activity of hypothalamic neurons is of a great importance in attempt to connect the neuronal function with its activity. We have proposed an original method of analysis of background and temperature-induced impulse activity of thermosensitive neurons from frontal hypothalamus. In acute experiments on cats under ketamine anastasia neuronal activity was measured by glass microelectrode. Measurements of background neuronal activity was performed during 30 s, and post-stimulus activity was measured during 60 s. Computer program calculated the mean value of background activity. These results were used to create bar graph in the range +/- 100% with time interval 10%. It is suggested that the results of analysis of background activity of thermosensitive hypothalamic neurons allow interpret the characteristics of functions of hypothalamic neurons.

Animals↗
PubMed2003

[Pneumo-automatic apparatus for the artificial ventilation of the lungs for small laboratory animals].

We have designed apparatus of artificial ventilation of the lungs (AAV) for small laboratory animals on pneumoelements, examined static and dynamic characteristics of a generator of impulse signals and chose rational parametres of the apparatus. Some advantages of that model as compared with its analogues have been proved. The apparatus was approved at electrophysiological experiments on rats, 200-250 g. Monitoring of the most important parameters of the vital functions showed that external breathing on that apparatus was adequate.

Animals↗
PubMed1995

Experimental thyrotoxic myopathy: radioautography of protein synthesis in skeletal muscle and motor neurons of spinal cord.

The total protein synthesis was studied in skeletal muscle and spinal motor neurons in experimental thyrotoxic myopathy (TM) mice by using radioautography with 3H-methionine. A significant increase of mean specific radioactivity was found in motor neurons of mice with TM. No statistical differences were established in the level of 3H-methionine inclusions into muscle fibre proteins of experimental and control animals. Thus, the total protein synthesis in motor neurons is significantly increased with TM, while there is no change in the skeletal muscle. Our data suggest that muscular weakness in TM is not the consequence of protein metabolism disorders in skeletal muscle fibres.

Animals↗
PubMed1995

Clinical variability of facioscapulohumeral muscular dystrophy in Russia.

One hundred forty-two patients (66 men and 76 women) from 20 autosomal-dominant pedigrees and 3 families including 5 "sporadic" cases were examined. A great similarity of clinical manifestations among those affected was noted. Clinical variability of phenotypes reflecting various phases of the disease and different expressions of the mutant gene were always within the limits of the identical final phenotype of the disease, namely the facio-scapulo-humero-peroneal-femoro (posterior group of the muscles)-gluteal (gluteus maximus). Thus, the clinically and genetically homogeneous group of patients with autosomal-dominant descending with a "jump" form of facioscapulohumeral dystrophy (FSHD), called facioscapuloperoneal dystrophy (FSPD), was examined. Among the observed cases we did not come across any having the autosomal-dominant gradually descending form of FSHD, called facioscapulolimb dystrophy (FSLD), in which the pelvic and proximal lower limb muscles get weak earlier than in the peroneal group (anterior tibial) muscles. We could not reveal the "pure" facioscapulohumeral phenotype of muscle weakness in 142 examined patients. A "pure" FSHD does not exist as a nosological entity. It represents only the syndrome which characterizes the initial phase of FSLD, but not of the FSPD. It is quite probable that FSPD and FSLD which may be differentiated clinically are two different diseases connected with the mutation of allelic or even different genes. Linkage studies in FSPD and FSLD mapping genes would confirm this data.

Adolescent↗
PubMed1992

Terminal intramuscular motor innervation and motor end-plates in thyrotoxic myopathy.

Thyrotoxic myopathy was induced in 64 mice. Examination of their muscles revealed excessive axonal branching and degenerative changes of preterminal axons. Moreover, the mean diameter of their end-plates decreased and the levels of end-plate cholinesterase appeared to be reduced. In 43 patients with thyrotoxic myopathy, increased axonal branching and degenerative changes of preterminal axons, similar to those in the experimental mice, were also seen. The possibility that excess thyroid hormone may interfere with axonal transport or neuromuscular interactions is discussed.

Acetylcholinesterase↗
PubMed1991

[Motor innervation of muscle fibers in thyrotoxic myopathy].

In patients and test animals similar changes in innervation have been revealed. Degeneration of some preterminal axons has been shown. The most manifested feature's increased ramification of distal axons. No signs of real reinnervation have been found. New collateral branches of preterminal, terminal and ++ultra-terminal axons usually have their ends at the same muscle fiber in the form of additional nervous terminals. Decreased average diameter of motor end-plates, revealed in the test animals, depends not on their degeneration, but on formation of new small motor end plates as a result of immature axonal ramification of distal axons. Acetylcholinesterase activity in the end-plates is decreased. A suggestion is made that excess of thyroid hormones in the skeletal muscle disturbs both the system of cyclic nucleotides and mechanisms of muscular contraction, connected with it and axoplasmic transport, respectively. The changes of the terminal intramuscular innervation revealed, structures of the motor end-plates with a decrease of acetylcholinesterase activity are supposed to result from disturbances of neurotrophic regulation of the muscle fibers because of the disturbances of the axoplasmic current as the excess of thyroid hormones.

Adult↗
PubMed1991

[Differential diagnosis of thyrotoxic myopathy].

To differentiate between thyrotoxic myopathy and myodystrophy (of the limb-girdle type), severe myasthenia, polymyositis, Addison's disease, proximal spinal muscular atrophy, steroid myopathy and neurosis special diagnostic indices have been developed based on specific muscular weakness (and atrophy) pattern early in the disease, the sequence of separate muscles involvement as the pathological process progresses, disproportion between muscular weakness and atrophy, excessive folds of the skin above the affected muscles and the presence of deep reflexes, purposeful analysis of the anamnesis. The diagnosis is confirmed by thyroid function study and/or myopathy regression in response to antithyroid therapy.

Adolescent↗
PubMed1989

[Various problems of the pathogenesis of myopathy in patients with thyrotoxicosis].

In patients with thyrotoxic myopathy, histological investigation showed the decrease in mean diameter of skeletal muscles, and increased collateral branching of distal axons. The percentage of afflicted fibers was not high with focal pathology. The signs of true reinnervation were absent. Electroneuromyographic investigation confirmed mild myopathy. The authors discuss the possible participation of cyclic nucleotide system disorders in muscular weakness in these patients.

Adult↗
PubMed1987

[Thyrotoxic myopathy (clinical picture, diagnosis and principles of treatment)].

A series of 263 patients with thyrotoxic myopathy (TM) (47 males and 216 females) were studied. A total of 151 patients were investigated by the author and 112 case reports were taken from the literature. New clinical peculiarities of TM were detected. The author presented a quantitative assessment of the incidence, degree of weakness and atrophy of individual muscles, described the topography of muscular lesions at different phases of the development of thyrotoxicosis and myopathy. He also proposed an original formula of muscular weakness and atrophy which makes it possible to identify myopathy in its initial stage even when there are no evident clinical manifestations of thyrotoxicosis. Thus, a new method of early diagnosis of TM on the basis of topography of muscular lesions and other clinical characteristics is proposed. This method provides reliable evidence for the preliminary diagnosis of thyrotoxicosis. In addition to thyrotoxicosis correction the question is raised about the pathogenetic treatment of TM.

Adult↗
PubMed1986

Pathogenesis of experimental thyrotoxic myopathy.

Focal degenerative changes of skeletal muscle fibers (decrease in mean diameter, excessive axonal branching and a decrease in the mean diameter of motor end-plates together with a reduction of their acetylcholinesterase levels) were found by means of the experimental model thyrotoxic myopathy in mice compared to controls. A decrease in protein kinase affinity to cAMP and an increase in the number of nucleotide binding sites were revealed with a simultaneous decrease in cAMP level. The weakening of hormonal control of cAMP-dependent processes is probably the basic cause of muscular weakness and structural changes in skeletal muscles in thyrotoxic myopathy.

Acetylcholinesterase↗
PubMed1986

[Spinal facioscapulo-peroneal (or facioscapulo-crural) muscular atrophy and facioscapulo-peroneal muscular dystrophy].

A report is presented of a patient with lesions of muscles of the face, shoulder girdle, wrists and shins. The clinical findings were similar to those noted in a patient with facioscapuloperoneal muscular dystrophy. An analysis of statistical and dynamic formulas of muscular lesions with regard to electromyographic findings made it possible to determine the neurogenic nature of the damage. It is shown that under clinical conditions, using the formula of muscular lesions, one may differentiate between facioscapuloperoneal muscular atrophy and facioscapuloperoneal myodystrophy and Stark-Keser's spinal scapuloperoneal atrophy. It is proposed that the term neurogenic "scapulotibial syndrome" should be used instead of "scapuloperoneal" one.

Charcot-Marie-Tooth Disease↗
PubMed1985

[Changes in skeletal muscles in experimental thyrotoxic myopathy].

In an experimental model of thyrotoxic myopathy in mice certain decrease in average diameter of muscle fibers (MF) has been revealed (by 16%). In 1-20% of the MF various types of focal pathologic reactions (loss of cross and longitudinal striation, glial, glomerular and adipose degeneration, Zenker's necrosis) increasing number, structural changes and position of nuclei are observed. Degree of atrophy and part of the altered fibers depend on duration and severity of thyrotoxicosis. Morphologic disorders localize focally and are not so vast as to be the cause of muscle weakness. The main cause of the latter and of the structural disorders in the skeletal muscle at thyrotoxic myopathy is, evidently, slacken of the hormonal control in cyclic adenosine monophosphate-dependent processes.

Animals↗
PubMed1984

[Pathogenesis of experimental thyrotoxic myopathy].

The data obtained in mice with experimental thyrotoxic myopathy included a decrease in the median diameter of the muscle fibers by 17.1 per cent and various focal degenerative changes in less than 20 per cent of the muscle fibers; a statistically significant elevation in the activity of alpha-glycerophosphate dehydrogenase, as well as a reduction in phosphorylase activity and glycogen levels. There was also a significant diminution in the median diameter of the motor terminal plates, a decrease in cholinesterase activity and intensified collateral ramification of the distal axons. The major cause of the muscular weakness and structural changes in the skeletal muscles in thyrotoxic myopathy seems to lie in lowered cAMP concentrations and a weakened cAMP-dependent regulation of protein kinase.

Animals↗
PubMed1984

[Changes in muscle fibers of the somatic type in experimental thyrotoxic myopathy].

In mice used as a thyrotoxic myopathy model, activity of some oxidation-reduction enzymes, phosphorilase and glycogen content have been studied. Three series of experiments with separate controls have been carried out. Powdered thyroidin is given to the mice per os through a special cannula. The experiment is performed for 5 months. Musculus rectus femoris is studied. With development of thyrotoxicosis and myopathy, the diameter decreases and the form of the muscle fiber undergoes certain changes. alpha-glycerophosphate dehydrogenase (GPhDG) and succinate dehydrogenase activity increases. A definite division of fibers into two types, I and II remains unchanged, while differences between the fibers of I and Ia types disappear. The core-targetoid fibers are found among muscle fibers of I and Ia types, while those of "moth-eaten" belong to the II type. Glycogen content and phosphorilase activity decrease. Subdivision of the muscle fibers into the types according to the reactions revealing glycogen and phosphorilase activity is poorly expressed or absent. Adenosintriphosphatase and lactate dehydrogenase activities do not differ essentially from that in the control. Evidently, at hyperthyroidism the oxidation-reduction processes in the muscle fibers are disturbed and first of all in the link which is connected with the main enzyme (GPhDG) activity. This results in decay and disturbance of the myofibrillar proteins synthesis, serving as one of the reasons for appearance of the muscle atrophy.

Animals↗