The dissertation is devoted to the establishment of the main
pathomorphological manifestations of vascular remodeling of perifocal areas of
cerebral infarction in the dynamics of the recovery phase on the basis of
immunohistochemical, morphometric and electron microscopic study of their
changes in sectional and experimental material.
To achieve this goal the following research methods were used: light
microscopy, electron transmission microscopy, morphometry,
immunohistochemical determination of expression levels of markers VEGF-A,
VEGFR-2, CD 34, CD 105, MMP-9, statistical methods.
The study analyzes 174 observations of deceased patients with cerebral
infarction. Depending on the duration of the disease there are observation periods: 1
day, 3,7,14,21, 30 days or more.
The object of the study were perifocal areas of ischemic hemispheric
infarction of the brain, as well as areas outside the ischemic lesions.10
An experiment to model a cerebral infarction was performed on 35 white
Wistar rats weighing 200-220 g. both sexes. Five intact white rats formed a group of
control animals. The experimental material was studied by electron microscopy.
New data on the evolution of
structural damage to the microcirculatory tract at different times of ischemic stroke
have been obtained. The data on the features of the functioning capillary network in
the perifocal areas of infarction, the expression of CD 34, CD 105, the expression of 14
vasculoendothelial growth factor (VEGF-A) and its receptors VEGFR-2 at different
times of ischemic stroke. The role of matrix metalloproteinase (MMP-9) in the
processes of growth and remodeling of the vascular network in the dynamics of
ischemic stroke has been clarified. During the experiment on rats, new data were
obtained on ultrastructural destructive and reparative changes in the vessels of the
microcirculatory tract at different times of cerebral infarction. On the basis of a
complex morphofunctional assessment of the microcirculatory tract, the features of
vascular remodeling in the perifocal areas of ischemic stroke in the dynamics of the
acute phase are established.
To assess the effectiveness
of microcirculation in the perifocal areas of ischemic stroke, we must admit that an
early response to increase blood circulation in the perifocal areas of ischemic stroke
is increased collateral circulation, which can be assessed in histological specimens
by decreasing Kernogan index, increasing vascular density. It was found that severe
parenchymal edema without activation of cellular response, development of blood
stasis, the presence of erythrocyte and leukocyte aggregates, intravascular
hemolysis, the formation of fibrin clots in blood vessels is a prerequisite for severe
microcirculation disorders and indicates a lack of effective compensatory
mechanisms.
The expediency of assessing the activation of angio- and vasculogenesis by
increasing the area of expression of markers of neoangiogenesis, MMP9, the
appearance of endothelial proliferates and vascular budding is substantiated.
The results of this study will help to directly determine the timing of activation of
angiogenesis, which should be used in pathological practice for the analysis of
thanatogenesis in ischemic stroke.
