Biomedical subjects
I A Makarova
Publications and source records attributed to I A Makarova.
[The dynamics of interhemispheric asymmetry during the processing of a transcallosal signal].
Multiple homotopic transcallosal responses were led from the visual, temporal, auditory and motor cortical areas in Wistar rats. Temporal parameters of positive as well as negative components of the responses revealed alteration of the interhemispheric asymmetry by the rule of right-left-right shifting. By the amplitude parameters of negative components the asymmetry was right-left-right whereas by the positive oscillations amplitude it was left-right-left. The data obtained suggest a right-left-right pattern of domineering of the hemisphere cortex in processing of transcallosal signal.
[The sex dimorphism in the dynamics of interhemispheric asymmetry during the processing of a transcallosal signal].
Two main patterns of interhemispheric domineering were distinguished: the right-left-right shift type and the left-right-left one. The domineering of the right hemisphere at the beginning and the end of processing of a transcallosal signal, was stronger in female rats in some areas, whereas in the majority of the areas under study domineering of the left hemisphere occurred more frequently in male rats. The data obtained suggests a greater participation of the right hemisphere cortex in females and the left hemisphere in males.
[The treatment of patients with imported helminthiases].
The authors treated helminth infestation in 856 patients who have arrived to Russia from tropical countries. Early diagnosis and treatment of helminthiasis in such patients reduce their susceptibility to other diseases in the course of relevant adaptation to new climatic conditions. The authors point to high efficacy of the drugs mebendazol, albendazol, medaminol (against ancylostomiasis, ascariasis, trichocephaliasis), praziquantel (against schistosomiasis and hymenolepiasis).
Ontogenesis of transcallosal responses in cats: I. Formation of interhemispheric connections in kittens in the first month of life.
In acute experiments on kittens at the age of 1 to 30 days, anaesthesized with nembutal and immobilized with diplacine, multiple transcallosal response (TCR) recording from different cortical areas was performed. In 2-15-day kittens homotopical TCRs appeared earlier, were wider represented, and revealed a greater configuration maturity and amplitude-time parameters in associative (parietal and sensorimotor) areas as compared to projection (somatosensory, visual and auditory) zones. It has been established that interhemispheric relations in the kitten associative cortex are mediated, not only by the callosal, but also by the extracallosal system, which was evidenced by the presence of late negative components preserved after callosotomy. The results of per-layer analysis of interhemispheric responses in 1 month kittens have shown that in the parietal cortex, in the course of development, the drains of surface-positive oscillation shifted from the V to the III layer, whereas the drain of surface-negative deviation remained at the level of II-III layers. The late component was registered at the depth of layers III-IV, having a drain in the I-II layers. In the sensorimotor cortex, the surface-negative oscillation had a drain in the I-II layers, whereas the surface-positive oscillation had a drain in the II and V-VI layers. The data obtained reflect the dynamics of the formation of interhemispheric relations in the first-month-of-life kittens and testify to an increased level of their integrative interaction.
Ontogenesis of transcallosal responses in cats: II. Formation of interhemispheric asymmetry.
Experiments were performed on 59 kittens of both sexes at the age of 1 to 30 days after birth, anaesthesized by nembutal and immobilized by diplacinum, using the technique of multiple topographical TCR recording. TCRs being recorded from symmetrical points of the right and left hemispheres, interhemispheric asymmetry of their amplitude time parameters was revealed, which arose immediately following TCR appearance. In the kittens' sensorimotor cortex TCR asymmetry was individual, whereas in the parietal cortex it was species-specific. One-hemisphere dominance in kittens possessed a partial character. During interhemispheric asymmetry formation, the callosal and the extracallosal systems participated. Asymmetry dynamism was revealed in asymmetry changing with kittens' age according to form (individual/species-specific) and magnitude (intensification/weakening up to changing its sign), and it was conditioned by differences in mechanisms of hemispheric interaction in the course of the cat's ontogenesis. The process of TCR asymmetry formation was characterized by zonal specificity. The general tendency of asymmetry development during ontogenesis in the cat was intensification, with age, of the integrative interaction of those systems which supported it.
[Patterns in the formation of transcallosal connections in the projection and associative areas of the cat cortex].
In acute experiments on immobilized 2-15-day old and adult cats, regularities of the ontogenetic callosal connexions maturation were studied in projection (somatosensory, auditory visual) and associative (sensorimotor, parietal) areas of the cortex by means of topographic recording of the transcallosal responses in symmetrical points of the opposite hemisphere. The data obtained suggest a heterochrony and different rate of the functional callosal connexions maturation in projection and associative areas of the cortex.
[Nature of transcallosal responses in the parietal cortex of the kitten].
In immobilized 2-18 day old kittens, transcallocal responses in the parietal cortex involved a positive--negative complex often accompanied by a negative deviation. The early positive--negative oscillation had a callosal, and the late one--an extracallosal nature. The layer-to-layer analysis of the transcallocal responses showed that the source of positive-negative component, as kittens develop, was transferred from V to III layer, whereas the source of the surface negative component remained on the level of II-III layers. The late negative component, having the cource in the layer I-II, was registered only up to the II-IV layers. The interhemispheric relations in the parietal cortex of kittens are actualized both by means of callosal and extracallosal systems and, with age, their interaction is intensified.
[Interrelations of the cerebral hemispheres in the cat in early stages of ontogeny].
Multiple recording of transcallosal responses (TCRs) from different cortex areas has been carried out by means of acute experiments with immobilized and anesthetized kittens at the age of 1 to 30 days after birth. Homotopical TCRs in kittens at the age of 2-15 days appear earlier, are presented wider and reveal features of a greater maturity configuration and of amplitudinal-temporal parameters in association zone (parietal and sensorimotor) in comparison with projection zones (somatosensory, visual and auditory). Interhemispheric interrelations in association cortex of kittens are carried out not only by means of callosal but extracallosal system. In the course of animal developing in the parietal cortex the drain of the surface-positive oscillation moves from V to III layer and the drain of the surface-negative deviation remains at the level of II-III layers. The late component is registered up to the depth of III-IV layers, having the drain in I-II layers. In sensorimotor cortex the surface-negative oscillation has the drain in I-II layers, surface-positive--in III and V--VI layers. The interhemispheric asymmetry emerging from the moment of responses appearance is peculiar to TCRs of projection and association zones. In the first month of the postnatal development the asymmetry of positive and negative TCR oscillation amplitude has an individual character in sensorimotor cortex and a specific one--in parietal. The temporal parameters of TCR in association areas of the left hemisphere cortex are significantly shorter than of the right one. The data given testify to the possibility of interhemispheric interrelation realization and the presence of interhemispheric asymmetry in cat's brain on the early stages of postnatal ontogenesis.
[Interhemispheric asymmetry of associative responses in the cat parietal cortex].
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The primary structure of Escherichia coli RNA polymerase. Nucleotide sequence of the rpoB gene and amino-acid sequence of the beta-subunit.
The combined structural study of proteins and of their corresponding genes utilizing the methods of both protein and nucleotide chemistry greatly accelerates and considerably simplifies both the nucleotide and protein structure determination and, in particular, enhances the reliability of the analysis. This approach has been successfully applied in the primary structure determination of the beta and beta' subunits of Escherichia coli DNA-dependent RNA polymerase and of their structural genes, yielding a continuous nucleotide sequence (4714 base pairs) that embraces the entire rpoB gene, the initial part of the rpoC gene and the intercistronic region, together with the total amino acid sequence of the beta subunit, comprising 1342 residues, and the N-terminal sequence of the beta' subunit (176 residues).
[Asymmetry in the cat motor cortex].
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[Transcallosal modulation of a focus of maximal activity in the motor cortex].
In acute experiments on cats, when recording EPs from 170 symmetrical points of the motor cortex, callosal influence on the maximal activity focus (MAF) was studied in conditions of stimulation of the sciatic nerves with different stimuli. After callosal transection, weak stimuli enlarged the MAF, strong one-narrowed it. The transcallosal modulation in intact brain is supposed to aid to delineate the MAF in the motor cortex and to exaggerate the differences between MAFs occurring at stimulation with different stimuli.
[Transcallosal modulation of a focus of maximal activity in the motor cortex].
In cats, EPs from 170 symmetrical points of the motor cortex were recorded during bilateral and unilateral stimulation of nerves of hind--and forelimbs. Charts of localization of the maximal activity foce (MAF) were drawn. Transection of the corpus callosum was shown to be followed by narrowing of MAFs during bilateral stimulation and by their enlargement during unilateral stimulation. The effect of MAF enlargement was found to be due to summation of thalamocortical and transcallosal projections in animals with intact callosal system, while the MAF narrowing effect--to be determined by reciprocal transcallosal influences. Existence of the spatial transcallosal modulation of thalamocortical projection in the motor cortex is supposed.
[The use of transfusion of freshly preserved blood and leukocytes in patients with tumors of the female genitalia during radiotherapy].
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Transcallosal modulation of a focus of maximal activity in the motor cortex.
Evoked potentials were recorded from 170 symmetrical points of the motor cortex in acute experiments on 10 cats anesthetized with chloralose and pentobarbital. Callosal influences on the focus of maximal activity (FMA) were studied during bilateral and unilateral electrical stimulation of the sciatic nerves at different strengths. During weak stimulation division of the corpus callosum was shown to broaden the FMA, but during strong stimulation the FMA was narrowed. It is suggested that transcallosal modulation in the intact brain leads to clearer demarcation of the FMA in the motor cortex and also increases the differences between FMAs arising during stimulation at different strengths.
Interhemispheric asymmetry of associative responses in the cat parietal cortex.
The asymmetry of associative responses in the parietal region of the cortex was experimentally studied during visual and auditory stimulation of tubocurarine-immobilized cats at various intensities with the multiple recording of evoked potentials (EP). The left-handed asymmetry of the early and late components of associative responses was established. It was shown that the zones of convergence of visual and auditory information are also asymmetric and predominate in the left hemisphere. By contrast to the projection regions, no strength or transcallosal modulation of the interhemispheric asymmetry could be found in the parietal cortex. The data obtained indicate the applicability of the principle of functional asymmetry to the activity of paired segments of associative cortical systems in animals.
Sexual dimorphism of the interhemispheric asymmetry dynamics during the processing of the transcallosal signal.
The characteristics of the dynamics of the functional interhemispheric asymmetry (FIAs) of the transcallosal influences in male and female rats were compared in this study through an analysis of the amplitude-temporal parameters of the homotopic transcallosal responses (TCR) in the course of their multiple topographical pickup from the dorsolateral surface of the cortex of both hemispheres in the time interval of the realization of the components of the responses. Two principal types of patterns of hemispheric dominance have been distinguished. The first type was described in accordance with the rule of the right-left-right shift of FIAs; the second type was described in accordance with the rule of its left-right-left shift. The changes in the FIAs of the temporal parameters of the positive components and the amplitude parameters of the positive and negative fluctuations were characterized by the identical type of dynamics in rats of both sexes. The dynamics of the FIAs of the temporal parameters of the negative components unfolded in accordance with the first type in the females, but in accordance with the second type in the males. The dominance of the investigated zones of the cortex of the right hemisphere was expressed more markedly in the females at the initial and terminal stages of the processing of transcallosal information. The phases of the dominance of the left hemisphere, by contrast, were identified and detected in a relatively larger territory of the neocortex examined in the males by comparison with the females. The results obtained suggest the relatively greater participation of the cortex of the right hemisphere in the females, but of the left hemisphere in the males during the processing of a transcallosal signal.