Submicroscopic Investigation of Components of the Hematoencephalic Barrier in Newborns with Perinatal Hypoxic Damage

Abstract

The biggest losses from the entire period of childhood fall on the neonatal period of development of ontogenesis. Clinical manifestations of diseases and morphofunctional disorders that occur during intrauterine development or during childbirth play an important role in the formation of the child's health and are recorded during the neonatal period of development. The more accurate is the diagnosis of pathology in this age range, the more correct and effective will be the measures of treatment and rehabilitation. This will reduce to a minimum social loss and limit the formation of chronic pathology and deviations in the physical, mental and intellectual development of children. The hematoencephalic barrier is the most important dynamic structure that it is responsible for brain homeostasis and takes an active participation in the body tissues resistance to the harmful effects of perinatal hypoxic stress alongside with other structural and functional formations of the central nervous system. The purpose of the work was to identify characteristic morphological and functional changes in the components of the hematoencephalic barrier of newborns who underwent to perinatal hypoxia at the subcellular level using submicroscopic examination. Results and discussion. The study results present a fragment of a large work which deals with pathomorphological and compensatory changes in the components of the hematoencephalic barrier in deceased newborns. The latter were carried in conditions of chronic intrauterine hypoxia and undergoing acute ante-, intranatal hypoxia were studied using ordinary histology, morphometry, immunohistochemical reactions. Submicroscopic examination allowed deepening the level of surveillance. The morphological changes in newborns who were carried under conditions of chronic intrauterine hypoxia, they underwent acute intrauterine hypoxia and died in the acute period of hypoxic-ischemic encephalopathy. These newborns can be divided into two groups. The first group: pathological changes which were the result of acute asphyxia – edema, death and desquamation of endothelial cells as well as damage of gliacytes and their further death both as a result of cytotoxic edema (edema and lysis) and due to shrinkage of the nucleus with subsequent karyorrhexis. The presence of apoptotic changes in pericytes was registered. The second group of pathomorphological changes had signs which were formed under the «chronic» influence of the damaging factor (in this study it was chronic intrauterine hypoxia): general decrease of the microcirculatory bed in the volume; significant decrease in the number of capillaries with a «sleeve» of astrocytes processes; damage of the basement membranes of the capillaries (uneven thickness, blurring, bilayering)