[PRECHORDAL AND MYOEPICARDIAL PLATES: TERMINOLOGICAL ASPECTS, THE PROBLEMS OF DEFINITION].

Most accurately, the prechordal plate (PCP) can be defined as the zone of close contact of cells of endodermal epithelium and mesenchyme in the region between the oropharyngeal membrane and the notochord. This structure is involved in the induction of the anterior parts of the brain and, in particular, the pituitary gland, as well as in the formation of some of eye muscles and bones of the skull base (chordal chondrocranium). Further studies are needed to clarify PCP involvement in the development of pharynx, esophagus, and their derivatives, as well as to determine the source and the mechanisms of development of PCP mesenchymal cells.

Parameters of estrous cycles in albino rats normally and after injection of xenogenic cerebrospinal fluid.

We studied biological effects of xenogenic cerebrospinal fluid. Injection of the liquor to albino female rats during different periods of postnatal ontogeny induced changes in the dynamics of estrous cycles. Changes in the picture of vaginal smears, duration of estrous cycles, and proportion between their phases were found.

Continuous laser radiation effect at 1.06 microns on gastrointestinal tract.

The thermal effect of 1.06 microns YAG:Nd laser irradiation at temperature conditions up to 100 degrees C without crater formation on gastrointestinal (GI) tissue samples was investigated. The theoretical and experimental data show that at an intensity of 160-400 W/cm2 laser-induced heating of the tissue with an initial temperature of 20 degrees C leads to coagulation lesions at a temperature no less than 60 degrees C and at a depth of 1.