[Provisionality phenomenon in the histo- organo- and systemogenesis].

This review summarizes the results of the study of the provisionality phenomenon in the development of the organs of the urinary system (mesonephros, metanephros) in viviparous (human, rat) and oviparous (bird) amniotes, human organs of mixed origin (pituitary, ovary, stomodeum) reparative regeneration of supporting tissues (in humans and Syrian hamster), morphogenesis of primary hepatic cancer developing against the background of superinvasive opisthorchiasis. It is shown that during the development of tissues and organs, the stages of provisional and definitive histo- and organogenesis could be determined; saltatory mechanism is typical for embryonic organogenesis (formation of cartilaginous skeletal primordia, meso- and metanephrons) and foci of oncogenesis. Transformation zones of the type of tissue organization in the epithelium are located in the areas of contacts of the derivatives of different embryonic primordia.

[The specific features of regenerative processes of hip and shin fractures in patients with superinvasion opisthorchiasis].

Opisthorchis superinvasion retains the natural manifestations of reparative regeneration of skeletal tissues, but activates proliferation stages and increases the promoter manifestations of histogenesis. Irrespective of a surgical option, the rate of infestation, and the place of residence, reparative regeneration of shaft fractures of the shin and hip occurs significantly more rapidly in patients with superinvasion opisthorchiasis than in those without the latter. In superinvasion opisthorchiasis, bone is restituted by early callus formation and accelerated regenerate mineralization.

Embryonic morphogenesis of the human pituitary.

Light microscopy methods were used to study the main stages in the organogenesis of the pituitary in human embryos at Carnegie stages (CS) 12-23. Rathke's pouch (RP) was shown to form as a traction fold over whole width of the roof of the stomodeum in embryos at CS 12 due to a flexure of the neural tube with which the epithelium had a tight anatomical relationship (the attached part of the anterior wall of the RP) in the median plane of the embryo. The rudiment of the hypothalamic infundibulum and neurohypophysis formed at CS 15, as a thickening of the posterior wall of the diencephalon.

[Human pituitary embryonic morphogenesis].

Basic stages of pituitary gland organogenesis were studied using the methods of light microscopy in human embryos at Carnegie stages (CS) 12-23 (25-57 postovulatory days). It is shown that Rathke's pouch (RP) is formed like a traction fold along the whole width of the stomodeum roof in embryos at CS 12 as a result of a neural tube bend, to which the epithelium is closely connected anatomically (attached part of RP front wall) in the middle plane of the embryo. At CS 15 the primordia of hypothalamic infundibulum and of neurohypophysis are formed as a thickening of diencephalic posterior wall.

[Role of provisionality principle in realization of phylembryogeneses].

The analysis of histogenesis of skeletogenic tissues and of organogenesis of the mesonephros and metanephros in higher mammalian animals and man, is presented. The new conception of provisionality is formulated, according to which embryonic primordium and/or its derivatives possess a determined capacity to form, on its course to definitive state, temporary structures (tissues or organs), which fulfil the vital functions in the developing organism and modeling the mechanisms of development and formation of structural and functional units or the whole organ at the level of definitive morphological substrate. Provisionality is regarded as the universal principle in realization of of phylembryogeneses.