[Morpho-functional characteristic of the lateral vaults of the epidural space of the spinal cord and their clinical significance].

The study of the epidural space was performed on 362 samples of the vertebral column obtained from the fetuses aged from 16 weeks, newborns, children and adult persons aged up to 90 years, using anatomical and histological methods. Within the lateral parts of the epidural space, the lateral vaults were distinguished. A new anatomical interpretation of these structures is proposed, considering them as a complex of anatomical structures including the periosteum of the intervertebral foramen, the sleeve of dura mater, intervertebral veins, spinal arteries, adipose tissue, the system of the connective-tissue trabeculae, recurrent nerves controlling the blood flow in the vascular system of the vertebral channel and promoting the communication of the epidural space with the paravertebral areas.

[Morphometric characteristic of the basilar part of occipital bone in different forms of the skull].

140 preparations of the skull base and 97 preparations of the skull sagittal saw cuts were used to study the craniometric characteristics of the basilar part of the occipital bone. The dependence of craniometric characteristics on sex and form of the cerebral cranium was tested. Correlations between these parameters were determined.

[Craniological basis of operative approaches to the structures of posterior cranial fossa using endovideo-monitoring].

Cranioscopic and craniometric characteristics of posterior cranial fossa and correlations between them were studied using 127 skulls with different cranial shape (dolicho-, meso- and brachicraniums). It was found that most of the craniometric characteristics were independent on gender and shape of the skull, while each characteristic had some individual peculiarities. Endovideomonitoring was used to assess the optimality of suboccipital paramedial and retrosigmoid approaches to posterior cranial fossa using 20 heads of the corpses belonging to adult individuals.

[Morphometric characteristics and correlation interdependence of the lacrimal sac fossa and nasolacrimal canal in cerebral and facial parts of the skull of various shape].

Morphometric characteristics of lacrimal sac fossa (LSF) and nasolacrimal canal (NLC) were studied in 105 macerated skulls of humans of mature age. Extreme shape variants were detected for LSF and NLC inferior foramen. The peculiarities of topographic-anatomical relations of NLC with the neighboring structures of nasal cavity were established.

Concealed nuclei in Saccharomyces strains.

We have found that cells derived from heterokaryons (HK) showing phenotypical traits, coded by the nucleus of one parental strain and by the cytoplasm of the other, may produce mitotic progeny in which the second nucleus is apparently present but not expressed. This 'concealed' nucleus can be forced to expression after growth of these cytoductants on proper selective media. Using a micromanipulator, the buds containing both parental nuclei were isolated in various crosses.

[Factors affecting the frequency of concealed heterokaryosis in Saccharomyces cerevisiae].

In this work, studies on the phenomenon of concealed heterokaryosis that we previously detected in the saccharomycetes yeast strains were continued. New approaches to high effectiveness of isolation of cytoductants carrying the concealed nucleus were implemented, and the composition of individual concealed heterokaryons, zygotic clones, and the first zygotic buds was analyzed by a micromanipulator. The relationship between a delay in the growth of the parental strain (a potential donor of the concealed nucleus) and a decline in the frequency of the appearance of concealed heterokaryons (HKC) was observed.

[Mathematic modeling of the shape and size of the ethmoidal labyrinth].

The present work was designed to study craniometric characteristics of ethmoidal labyrinths, facial and cerebral skeleton and to define mathematical correlation between the parameters of ethmoidal labyrinth and facial and cerebral skeleton. As a result average, minimal and maximal values of linear parameters and the parameters of the volume of ethmoidal labyrinths were calculated. Correlational, regressive and factor analyses of the craniometric characteristics studied were carried out.

[Detection of concealed "illegitimate" nuclei in tetrad analysis of the diploid progeny of heterokaryons in Saccharomyces cerevisiae].

In this work, the studies on the previously detected phenomenon of concealed heterokaryosis in Saccharomyces cerevisiae were continued. In genetic and Southern blotting experiments, one of the nuclei in the heterokaryon was shown to be active (capable of division and ensuring the corresponding cell phenotype), whereas the other was not expressed until the heterokaryotic clone was transferred to the medium selective for this concealed nucleus. Moreover, the concealed nucleus was able to assume the active state after fusion with the second parental nucleus.

[Cryptic heterokaryons in strains of Saccharomyces cerevisiae. Conditions for detecting a cryptic nucleus].

A phenomenon discovered earlier, cryptic heterokaryosis in Saccharomyces yeast, has been further investigated. A phenotypically silent nucleus in a yeast cell may resume its expression after fusion with another parental cell. The resulting hybrid is capable of sporulation.