[Guidelines for comprehensive assessment of educational and training conditions of children and adolescents].

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].

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.

[Actin-binding proteins in Xenopus laevis oocytes and eggs. I. Presence and distribution of alpha-actinin and vinculin].

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.

[The morphological criteria and proposed mechanisms of cortical contractility in oocytes of the clawed toad].

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.

[A 2-component cytoskeletal system as the basis of cortical contractility in clawed toad eggs].

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.