[Application of the method of acoustic microscopy for the study of eye tissues].

The paper describes the results of evaluation of potentialities of the application of scanning acoustic microscopy, which is still relatively new and as yet uncommon method of biological research, for the supravital study of animal eye structure in species with different eyeball size. Using the eyes of a goat, quail embryo (in situ) and frog tadpole (in vivo) as the examples, it was shown that non-destructive nature of the method used allows for the study of peculiarities of major morphologic structures in the state that is close to the natural one. Some acoustic images are presented showing eye structural elements along with the results of quantitative characteristic of the cornea, sclera and iris.

[The dependence of the differentiation potentials of fragments of the marginal zone in early gastrulas of the clawed toad on their morphogenetic movements]. / Zavisimost' differentsirovochnykh potentsii uchastkov kraevoi zony rannikh gastrul shportsevoi liagushki ot ikh morfogeneticheskikh dvizhenii.

Using Xenopus early gastrulae, we studied the dependence of differentiation potential of tissue fragments explanted from different regions of the marginal zone on the conditions promoting or preventing convergent-intercalation movements (CIM). Previously it has been shown that CIM are stimulated by surface tension usually produced in the embryo by folding (involuting) edge of cell layer. In the first experimental series, we prevented involution of tissue explanted from the region above blastopore by enveloping it in ectoderm of more advanced developmental stages. As the result, percentage of axial organs developed in such explants drastically decreased, whereas that of more ventral structures increased. In the second experimental series, an increase in percentage of axial structures that differentiated in tissue fragments explanted from the lateral part of marginal zone was achieved by stimulating involution of its dorsal edge. In the third series, it was shown that percentage of axial structures formed in ventral halves of embryos becomes significantly greater under the conditions that stimulate stretching of the surface and involution of the free edge of explants. A conclusion is drawn that regional specificity of differentiation potential, which is observed within the marginal zone, greatly depends on surface tension in the explants and, therefore, on morphogenetic movements proceeding in them.

[Body fluid and electrolyte content in rat tissues after space flight in the "Space-2044" spacecraft]. / Soderzhanie vody i élektrolitov v tkaniakh krys posle poleta na biosputnike "Kosmos-2044".

Contents of water, sodium, calcium and magnesium in different tissues of the rats stayed in space for 2 weeks in healing period of bone fracture following graded trauma of calf-bones as well as in the rats exposed to a head-down suspension (HDS) have been studied. In microgravity-exposed animals there were no significant changes in fluid-electrolyte composition of the liver, kidney, myocardium, skin, bone (calf bone). Specific "functional load" on the system of fluid-electrolyte homeostasis in the form of operation and subsequent healing of bone fracture did not result in additional changes in fluid and electrolyte contents of body tissues. In the HDS animals there was a significant change in fluid-electrolyte composition of skin, kidney and bone tissue.

[Antigenic structure of the foot-and-mouth-disease virus. I. Synthesis of protective peptides from the major immunogenic region of VP1 protein of foot-and-mouth virus type O1K]. / Antigennaia struktura virusa iashchura. Sintez protektivnykh peptidov posledovatel'nosti osnovnogo immunogennogo raiona belka VP1 virusa iashchura shtamma O1K.

A series of overlapping peptides with the sequence of the immunodominant region of VP1 protein of FMDV strain O1K have been synthesized by the classical solution method. Peptides were purified by standard methods and used for immunization of guinea pigs. It is shown that the 136-152 and 136-148 segments provide antiviral protection in guinea pigs, both in the free state and conjugated with an immunogenic carrier. Results with uncoupled peptides indicated that these segments may form not only B-, but also T-cell affecting sites.