[Muscle post-effects and upright standing in healthy subjects and patients with sensory-motor integration disorders].

We compared the upright standing in 7 patients with sensory-motor disorders and 7 healthy subjects (control) before and after 30-s involuntary neck muscle contraction. A trajectory of the center of pressure was recorded during 30-s standing with the eyes open, eyes closed and standing on a foam-rubber with the eyes open. As compared to healthy subjects, patients exhibited an increased body sway area during standing with the eyes open on both the firm surface and foam-rubber and a backward shift of the center of pressure during standing with the eyes both open and closed. Closing the eyes affected the upright standing of patients to a lesser extent than standing of healthy subjects. Involuntary neck muscle contraction within 30 s elicited a backward shift of the center of pressure in healthy subjects, especially during standing with the eyes closed, and a decrease in the length of the center-of-pressure trajectory, especially of its frontal component during standing on the foam-rubber. In patients, a post-effect of the neck muscle contraction manifested itself as a decrease in the body sway area during standing on the foam-rubber and relative increase in the frontal component of the center-of-pressure trajectory during standing with the eyes closed. The results suggest that the upright standing of patients with sensory-motor disorders is more sensitive to somatosensory than visual input, and 30-s neck muscle contraction approach their postural stability to the age-matched control.

[Age-related structure of miners population in dependence on work conditions].

The authors analyzed age-related structure of miners population in major occupational groups with connection to special work conditions in one mine of Kouzbass. The data obtained prove certain influence of work conditions on age-related structure of occupational population.

[Isolation and molecular cytogenetic characteristics of the alpha-satellite DNA of human chromosome 6]. / Poluchenie i molekuliarno-tsitogeneticheskaia kharakteristika al'fa-satellitnoi DNK khromosomy 6 cheloveka.

In this work a molecular-cytogenetic characteristic has been given to the alpha-satellite DNA of chromosome 6. Using different restrictases made it possible to evaluate structural heterogeneity of the obtained subgroup of the alphoid DNA. Polymorphic restriction fragments of DNA have been found which can be used in determining linkage groups.

[Determination of the nucleic acids in pig embryonic kidney cells by magnetic cytaphoresis]. / Opredelenie nukleinovykh kislot v kletkakh SPEV metodom tsitomagnitofeza.

Gallocyanine-chrome alum-stained pig embryonic kidney cells have paramagnetic properties. They move under the influence of gradient magnetic field (magnetophoresis). The velocity of magnetophoresis is proportional to the content of nucleic acids in cells. This allows to estimate the content of nucleic acids per cell dry weight by magnetophoresis and analytical centrifugation.

[Silver staining of the nucleoli of pig embryonic kidney cells during the hyperactivation and inhibition of the synthesis of nucleolar RNA by UV microirradiation]. / Okrashivanie serebrom iadryshek kletok SPEV pri giperaktivatsii i ingibirovanii sinteza iadryshkovoi RNK u UF-mikrooblucheniem.

Silver staining of the nucleoli in pig embryo kidney cells (PK) was studied during the cell cycle and also upon mature nucleoli modifications induced by UV microirradiation. During anaphase only four silver-stained granules were revealed in each daughter set of chromosomes in the four nucleolus-organizing regions (NORs). In the following 1-2 hours, the number of granules in the NORs rapidly increased up to 25-30 per nucleus. During the next 20-25 hours of the cell cycle, the number of silver-stained granules was slowly doubling as the nucleoli grew in size. UV microirradiation of one nucleolus in the nucleus with two nucleoli induced a profound degradation of the injured nucleolus and a compensatory hypertrophy of the intact one. Such nucleolar modifications were accompanied by redistribution of the silver-stained granules between the injured and non-injured nucleoli and by alterations in the levels of nucleolar RNA synthesis in the NORs. These data support a hypothesis that silver-stained proteins may be involved in the regulation of the nucleolar activity.

[Role of several subcortical nuclei in the conduction of visual afferentation during early ontogeny]. / O roli nekotorykh podkorkovykh iader v provedenii zritel'noi afferentatsii v rannem ontogeneze.

Characteristics of EPs in different areas of the visual cortex elicited by stimulation of subcortical nuclei (LGB, posterior thalamic nuclei and superior colliculi) were studied in cat's fetuses during the last 10 days of their antenatal development. It was shown that both in the striate and in accessory visual areas the EPs are negative oscillations with a small initial positivity. Latencies of the EPs to stimulation of the thalamic nuclei make from 18 to 25 msec in different cortical areas and those to the stimulation of the superior colliculi--from 40 to 45 msec. Laminar analysis of EPs elicited in the occipital cortical area by the stimulation of LGB revealed two foci of depolarization; the one with shorter EP latency is localized in the depth of the cortex. The role of the extrageniculate ascending system and of different groups of fibers of the geniculocortical system in the formation of the main EP components in the visual cortex in early ontogenesis is discussed.

[Laminar analysis of evoked potentials of the cat visual cortex during prenatal ontogenesis]. / Posloinyi analiz vyzvannykh potentsialov zritel'noi kory koshki v prenatal'nom ontogeneze

A laminar analysis of visual evoked potentials recorded from the cortical striate zone in response to stimulation of the optic nerve was made on the cats foeti in the second half of antenatal development and on kittens in the first few days of their life. In all the investigated terms of prenatal ontogenesis, two negativity foci are distinctly revealed in the specific zones of the visual cortex. The first appears with the least latency in the middle cortical layers after an afferent volley inflow to the cortex. The second, which reaches a maximum in 40 to 50 msec appears in the superficial cortical structures. Analysis of the data obtained shows that the first excitation focus is due to the summation of EPSP in the neural elements of the middle cortical layers, while the second is caused by development of depolarization in the apical dendrites of the pyramidal neurones.

[Functional maturation of the cat visual cortex during prenatal ontogenesis]. / Funktsional'noe sozrevanie zritel'noi kory koshki v prenatal'nom ontogeneze

Development of the perceiving function of the visual cortex was studied on the foeti of cats in the second stage of antenatal development with intact placental blood circulation. It has been found that functional maturing of the cortical end of the visual analyser starts at the beginning of the second half of antenatal life. At this period EPs to stimulation of the optic nerve are recorded throughout the dorsal cortex of the contralateral hemisphere. At first they appear as slow three-phase (positive-negative-positive) oscillations of a small amplitude. As the foetus develops, the EP amplitude increases, and the EP configuration in the striate zone of the cortex becomes complex. Two weaks before birth, a short-latency negative wave appears against the background of the primary positive oscillation. In the last week of antenatal development of the foeti and in the first few days of the kittens life, EPs are represented in the specific zone of the visual cortex (g. lateralis) as two negative oscillations, and in the so-called associative zone (the middle part of the suprasylvian gyrus) by one long-latency high-amplitude negative oscillation which corresponds by latency to the second negative EP component in the striate cortex.