Vol 148, No 4 (2015)

The study was conducted on 6 female and 36 male adult Wistar rats to compare the effects of dissociated cells derived from different embryonic CNS anlages, on the growth of regenerating nerve fibers in the damaged nerve of the recipient. After the sciatic nerve was damaged by ligation, part of the animals received the injection into the proximal portion of the nerve with a suspension of the cells obtained by dissociation of the fragments of spinal cord or forebrain vesicle taken from rat embryos at Day 15 of development. The analysis of transverse semithin sections of the distal part of the nerves was performed 21 and 60 days after surgery. It was found that the number of regenerating myelinated nerve fibers was increased 60 days after the injection of dissociated embryonic spinal cord cells, but not the neocortical cells, into the damaged nerve of the recipient.

The changes of the cellular composition of splenic lymphoid tissue were studied 7, 15 and 30 days after irradiation with a dose of 50 rad, in ВALB/c mice which received either distilled water or light (deuterium-depleted) water for a long time prior to and after irradiation. The irregular pattern of changes of splenic cellular composition was observed during the experiment. It was found that at day 7 after irradiation, the splenic structural zones in mice demonstrated a sharp decrease in the number of blast forms and mitotic cells, reflecting a lower level of lymphocytopoiesis, as well as an increased cellular destruction in mice consuming light water. By day 30 of the experiment, different responses of lymphoid structures were observed in the organ. In the periarteriolar lymphoid sheaths, the processes of cellular composition regeneration were more pronounced than in the germinal centers of lymphoid nodules, indicating the enhancement of body cell-mediated immunity and immunomodulating properties of light water in mice at later dates of post-irradiation period.

The aim of this work was to study the morphological changes of liver in common voles (Microtus arvalis Pallas) inhabiting the territories of brown coal deposition in Borodino coal opencast (Krasnoyarsk region) and on reclaimed dumps 10 and 20 years after its production. Trapping of the voles (10 animals in each group) living under natural conditions on each territory, was conducted for 30 days. Histological examination of the liver in all animals demonstrated degenerative changes and necrosis of hepatocytes, expressed to a various degree. Morphometric study has shown that the greatest changes in the structure of hepatic stroma and parenchyma took place in voles that lived in the dumps of coal, reclaimed 10 years before. It was found that in the animals of this group, the thickness of hepatocyte plates was increased 1.3 times, while the specific volume of necrotic hepatocytes was twice as much as this parameter in the animals that lived on intact territory.

With the aim of developing standards and conducting comparative analysis of the level of puberty in rural schoolchildren of Nizhniy Novgorod region, with regard to the temporal and territorial factors, 2411 individuals of both sexes aged 11-17 years were examined. During medical examinations, that were conducted in 2011-2013, the development of secondary sexual characteristics was characterized. The results obtained were compared with those received in 1967-1968 surveys and in the studied of modern children and teenagers living in the city of Nizhniy Novgorod. It was found that the level of puberty in rural schoolchildren has grown statistically significantly over the past 45 years. The appearance of secondary sexual characteristics in boys was accelerated by 2-3 years. In girls, the shift of 1-2 years was observed, while the sequence of their development remained unchanged, and in boys it was accompanied by the delayed growth of the thyroid cartilage. Among rural and urban boys, the differences in the level of puberty was less pronounced than among the girls. By the rate of passage of puberty transformations, rural girls lag behind their urban peers for 1 year. Modern rural students of Nizhny Novgorod region are characterized by higher variability of the manifestation of secondary sexual characteristics and their expression than in other regions of the country, especially among boys.

Using the technique of histochemical detection of enzyme acetylcholinesterase (AChE), the existence of the loci with high enzyme activity in the lateral nucleus of the lateral posterior thalamic complex was demonstrated in 2-week-old kittens (n=4) in contrast to the kittens aged 14 weeks (n=4). These loci were located opposite similar loci in the medial nucleus of the lateral posterior thalamic complex. Possible link between identified AChE-positive loci and the organization of thalamo-cortical and cortico-thalamic projections is discussed.

Methods for three-dimensional visualization of histological film preparations were developed using traditional flat-field microscopes. Preliminarily, the structures examined acquired the light reflecting ability by the reduction of silver nitrate impregnating them. Microscopy of preparations is carried out in reflected incident tenebrous illumination. The methods of processing of preparations for the study of cell surface relief, limiting membrane of the mesothelium and subsurface collagen fibers. Preparations are stored and examined in the wet state

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. The term «prechordal plate» should not be confused with the Spemann’s organizer, head organizer, oropharyngeal membrane, mesendoderm, head process and the prechordal mesoderm, which is common in the scientific literature. The term «myoepicardial plate» falsely indicates the common origin of myocardium and epicardium, thus its usage should be avoided.