[Guidelines for comprehensive assessment of educational and training conditions of children and adolescents]. / Metodologiia kompleksnoi otsenki uslovii vospitaniia i obucheniia detei i podrostkov.

General guidelines have been developed to make a comprehensive assessment of the conditions of education and teaching and to predict probable changes in preschool- and schoolchildren's health. The guidelines envisage the use of standard procedures and programmes for the assessment and optimization of educational and teaching conditions for children and adolescents in educational establishments of different types.

[The effects of exogenous actin-binding casein kinase injected into the oocytes and ova of the clawed toad]. / Effekty ékzogennoi aktinsviazyvaiushchei kazeinovoi kinazy, in''etsirovannoi v ootsity i iaitsa shportsevoi liagushki.

The effects of microinjections of exogenous casein kinase 2 on the structural organization of the maturing oocytes and eggs were studied in Xenopus laevis. Kinase inhibited the progesterone-stimulated oocyte maturation and induced dislocation of pigment granules. The morphological effect was shown to be dose-dependent. The results obtained are discussed in the light of the possible influence of casein kinase 2 on the organization of the cortical actin cytoskeleton through phosphorylation of actin-binding proteins.

[Actin-binding proteins in Xenopus laevis oocytes and eggs. I. Presence and distribution of alpha-actinin and vinculin]. / Aktinsviazyvaiushchie belki v ootsitakh i iaitsakh shportsevoi liagushki. I. Prisutstvie i raspredelenie alpha-aktinina i vinkulina.

We studied the distribution of two actin-binding proteins, alpha-actinin and vinculin, in the oocytes and eggs of Xenopus laevis. These proteins are localized in the cortical area. A morphological connection of vinculin with the mirofilaments and plasma membrane was shown; the actin matrix in the egg was gold-labeled more intensely than in the oocyte. A possible role of these proteins in development of the cortical contractility and rearrangement of the actin cytoskeleton during oocyte maturation is discussed.

[The morphological criteria and proposed mechanisms of cortical contractility in oocytes of the clawed toad]. / Morfologicheskie kriterii i predpolagaemye mekhanizmy kortikal'noi sokratimosti ootsitov shportsevoi liagushki.

It is proposed to consider certain states of the cortical actin cytoskeleton corresponding to various stages of oocyte maturation as morphological criteria of the cortical contractility during progesterone-induced oocyte maturation. In the definitive oocyte, the cortical microfilaments form an anisotropic network, while in the mature egg, they form an isotropic disorganized network and, at the moment of contraction, bundles. Factors of the actin cytoskeleton transformation are discussed: actin-binding proteins, protein kinases, and bivalent ions. The data are given on the presence and distribution of the actin-binding protein vinculin in the cortex of the oocyte.

[A 2-component cytoskeletal system as the basis of cortical contractility in clawed toad eggs]. / Dvukhkomponentnaia tsitoskeletnaia sistema kak osnova kortikal'noi sokratimosti v iaitsakh shportsevoi liagushki.

The cortex of Xenopus laevis eggs includes as two components the plasma membrane with underlying microfilaments (external layer) and cytoplasmic matrix with embedded pigment granules (internal layer). The both components of the egg cortex are capable of contraction under the influence of calcium ions. The cortex of the fully grown oocyte is not capable of contraction but acquires it during progesterone-stimulated maturation, when the oocyte is transformed in the egg. It has been proposed on the basis of the data on the cortex cytoskeletal organization that in the oocytes the submembranous microfilaments form an anisotropic network, which is transformed in an isotropic randomly organized network in the egg. The latter is capable of contractile acts. Reorganization of the cytoskeleton in the internal cortex layer leads to formation of the actin contractile gel. The data are provided on the role of actin-associated proteins in changes of organization of the actin cortical cytoskeleton. Mechanisms underlying different sensitivity of microfilaments of the internal and external layers to cytochalasin B are discussed, as well as coordinated (in time) development of the contractility in these layers. A proposed model of development of the cortical contractility during oocyte maturation is based on the concept of two-component cytoskeletal system.

[A morphological study of the keratin cytoskeleton of the oocyte from the clawed toad using heterologous monoclonal antibodies]. / Izuchenie morfologii keratinovogo tsitoskeleta ootsita shportsevoi liagushki s pomoshch'iu geterologicheskikh monoklonal'nykh antitel.

Heterologous monoclonal antibodies E2 (against rat cytokeratin 8) and OSC-1 (against cytoskeletal preparations of mouse oocytes) were used to study the presence and distribution of cytokeratins in Xenopus oocytes during their maturation and growth. To improve visualization of cytokeratins, more adequate methods of oocyte fixation and processing were developed. The results on distribution of cytokeratins obtained with the above mentioned antibodies were compared with one another and with published data. It was found that data obtained by different authors, who used different types of antibodies and different methods for fixation and visualization of Xenopus oocyte cytokeratins, are often contradictory and inconsistent. Along with that, common features of cytokeratin distribution are revealed that have been noticed by every author: animal-vegetal asymmetry of cytokeratin distribution and the existence of two keratin domains, cortical and ooplasmic ones. Specific for the cortical domain of the animal hemisphere is the arrangement of filaments in parallels to the surface, whereas filaments of the ooplasmic domain are oriented radially. The vegetal hemisphere is characterized by the presence of a network formed by filaments with different orientation. We also describe certain peculiarities of cytokeratin distribution in previtellogenic oocytes, as well as disintegration of the keratin system by the end of oocyte maturation.

[The participation of polymerized actin in maintaining the spatial organization of the oocyte in the clawed toad and its detection in the deep regions of the ooplasm]. / Uchastie polimerizovannogo aktina v podderzhanii prostranstvennoi organizatsii ootsita shportsevoi liagushki i ego vyiavlenie v glubokikh oblastiakh ooplazmy.

Microfilaments were shown to be involved in maintaining spatial organization of the Xenopus laevis oocyte by using injections of DNAse I, which selectively destroys F-actin. An original method has been proposed for visualization of polymerized actin at the electron microscope level. Standard histological sections (5-6 um) were deparaffinized, treated with gold-labelled phalloidin, dehydrated, and embedded in epoxy resins using gelatin capsules placed onto sections. After resin polymerization, the section separated from the slide in liquid nitrogen was cut in ultrathin sections on an ultratome. This method allows to by-pass the cutting on an ultracryotome and to study the distribution of polymerized actin in any region of the oocyte at the electron microscope level. The method allows to make the light immunohistochemistry data more precise. We have shown using this method the presence of F-actin not only in the cortex, as was established earlier, but also in deep layers of the ooplasm. Some aspects of the intracellular matrix organization are discussed.

[Contractile proteins and nonerythroid spectrin in the oogenesis of the clawed toad]. / Sokratimye belki i neéritroidnyi spektrin v oogeneze shportsevoi liagushki.

Distribution of contractile proteins, actin and myosin, and spectrin was studied in oogenesis of X. laevis. These proteins are present already at the previtellogenic stages, where they are diffusely distributed. During vitellogenesis actin and myosin are distributed in the animal region in a fibril-like way, while in the vegetal one they are concentrated around the yolk platelets. In the mature oocyte, distribution of actin and myosin again becomes diffuse. Spectrin forms in the vitellogenic oocyte a network all over the cytoplasm, while in the full-grown oocyte it is localized mostly in the subcortex of the animal region and disappears during oocyte maturation. All these proteins are present in the nuclei of oocytes. Changes in distribution of actin, myosin and spectrin during oocyte maturation are discussed with reference to the cortical contractility, spatial distribution of yolk platelets and regional sensitivity to cytochalasin B.

[The distribution and relation to the cytoskeleton of specific prosomal proteins in the oogenesis of the clawed toad]. / Raspredelenie i sviaz' s tsitoskeletom spetsificheskikh prosomnykh belkov v oogeneze shportsevoi liagushki.

Using immunoblotting and immunofluorescent microscopy, we showed the presence in Xenopus laevis oocytes of two prosomal proteins (27 and 31-33 kDa) and studied their distribution during oogenesis. In the ooplasm, both proteins are detected in prosomal clusters of various size. During previtellogenesis, prosomal proteins are diffusely distributed in the nucleoplasm and form evenly distributed clusters in the cytoplasm. During oocyte growth, prosomal proteins disappear from the nucleus and form animal-vegetal and cortical gradients in the cytoplasm. In the course of oocyte maturation prosomal clusters become smaller. After artificial activation of the egg, the dorso-ventral gradient of distribution of prosomal proteins is observed. Double immunohistochemical labeling revealed morphological association between prosomal clusters and fibril-like structures of the oocyte containing actin and myosin. The latter are then replaced by diffusely distributed actin and myosin. Thus, correlation is observed between localization of the acto-myosin complex of the oocyte and that of prosomal proteins.

[The system of continuous postgraduate education of public health physicians and its optimization]. / Sistema nepreryvnogo poslediplomnogo obuchenia sanitarnykh vrachei i puti ee optimizatsii.

The paper describes the system of continuous post-graduate advanced training proceeding from the example of physicians who participated in the training course at the chair of child and teenage hygiene at the Central Institute for Advanced Medical Studies during correspondence and full-time training travelling cycles. The work was conducted with the group of physicians (153 persons), participants of the experimental group--15 physicians from the city of Yaroslavl and Yaroslavl region. The targeted training was carried out in the form of post-cycle training: subject studies, consultations and seminars conducted by the statt of the chair, performance of scientific and practical work, etc. during 2-5 years. As evidenced by the studies conducted the methods and methodology used for studying the efficiency of training can be recommended for other chairs and institutions engaged in advanced training of sanitary physicians.

[The organization of the cortical layer of amphibian ova. 1. The ultrastructure of the cortex of the oocytes and ova of the clawed toad: the effect of divalent cations]. / Organizatsiia kortikal'nogo sloia iaits amfibii. 1. Ul'trastruktura korteksa ootsitov i iaits shportsevoi liagushki: vliianie dvukhvalentnykh kationov.

Ultrastructure of oocyte and egg cortical layer isolated in media containing various ions has been studied. The following results were obtained: 1) in cortical layer a two-component cytoskeletal system is present; morphology of this system changes during development; 2) cytoskeleton of the egg cortex acts as a two-component system in response to the influence of Ca2+: the cortex per se is destroyed while subcortex is contracted; 3) cytoskeleton of the oocyte cortex is destroyed under the influence of Ca2+; 4) nature and sensitivity to the absence of Mg2+ in the medium varies for cytoskeletal structures of oocyte and egg cortex.

[Status and prospects of the development of postgraduate training of public health physicians in child and adolescent care]. / Sostoianie i perspektivy razvitiia poslediplomnogo obucheniia sanitarnykh vrachei po gigiene detei i podrostkov.

The state and dynamics of postgraduate education of sanitary physicians and their assistants on child and adolescent hygiene were analyzed during 1972-76 and 1982-86 in the Soviet Republics and the USSR in general. Causal and effective relationships of the detected drawbacks were established and ways of their elimination according to the restructuring of the system of refresher courses in public health presented.

[Chronology of the embryonic development of the common frog]. / Khronologiia zarodyshevogo razvitiia travianoi liagushki.

The tables of embryonic development of the common frog (Dabagyan, Sleptsova, 1975) have been made more precise: more precise timing of successive developmental stages (in the number of tau 0) from fertilization till hatching was provided and new drawings of the embryos during gastrulation were given.

[Does Masui's Ca-sensitive cytostatic factor exist in the cytoplasm of mature nonactivated eggs of Acipenser stellatus, Rana temporaria and Xenopus laevis?]. / Sushchestvuet li Ca-chuvstvitel'nyi tsitostaticheskii faktor Masui v tsitoplazme zrelykh neaktivirovannykh iaits Acipenser stellatus, Rana temporaria i Xenopus laevis?

The cytoplasm of mature non-activated and cleaving eggs of A. stellatus and R. temporaria had no cytostatic effect. The cytoplasm treated with EGTA, being injected in one of two blastomeres of the cleaving egg of the same species, inhibits fully or partially the cleavage. The nuclei in the "arrested" blastomeres had, however, vesicular structure but were not blocked at metaphase, as could be expected if the cleavage was inhibited by a cytostatic factor described by Masui (1974). The portion of perished embryos and "arrested" blastomeres was shown to increase with the dose of EGTA injected in the egg, donor of cytoplasm. In the experiments with reciprocal injections of the intact cytoplasm of the mature non-activated eggs in one of two blastomeres of the recipient embryo carried out on R. temporaria and X. laevis, the cytoplasm of X. laevis only arested the cleavage but in this case as well only 4 out of 32 "arrested" blastomeres were at metaphase. The cytostatic effect observed in our experiments was not, hence, similar to that observed by Masui on R. pipiens.

[Electron microscopic study of the development of cortex contractility in the frog oocyte]. / Elektronno-mikroskopicheskoe izuchenie stanovleniia sokratimosti korteksa ootsita travianoi liagushki.

The intact and isolated cortices of the Rana temporaria oocytes were studied at different stages of maturation by means of electron microscopy. In the isolated cortex of definitive oocyte the microfilaments were concentrated mainly in the microvilli, whereas under the plasma membrane there was only a thin disordered net of microfilaments. At the stage of the germinal vesicle breakdown and in the ovulated oocyte the microfilaments of isolated cortices formed relatively strong randomly distributed bundles under the plasma membrane. When the oocyte surface was cut through, the microfilaments could form oriented bundles only in cases the oocyte cortex was characterized by distinct contractility.