[MORPHO-FUNCTIONAL CHANGES OF THYMUS TISSUES IN CHILDREN WITH CONGENITAL HEART DISEASE].

Biopsy specimens of the thymus were studied in children aged under 11 months (n = 77) with congenital heart defects and circulatory hypoxia of varying severity. Histological sections were stained with hematoxylin-eosin and Shubich's method (to demonstrate mast cells). The expression of Ki-67, CD3 and CD34 was assessed by immunohistochemistry. The ultrastructure of thymic tissues was also examined. It was found that the severity of hypoxia determined the morphological changes in the organ associated with a development of large complex of tissue reactions. A disruption of internal structure and a loss of integrity of epithelio-reticular cells and thymocytes were demonstrated in ultrathin sections. Thymocyte proliferation index (Ki-67) and thymocytopoiesis intensity (CD3+) were reduced in all the zones of the thymus. The degree of hypoxia affected the redistribution of CD3+ lymphocytes leading to their accumulation in the medulla. The processes of endogenous regeneration took place which involved the cells of fibroblastic line and progenitor cells (CD34+) together with active formation of new blood vessels. These findings suggest that the morphological changes identified in the tissues of the thymus are a manifestation of tissue adaptation to hypoxia of varying severity under conditions of endogenous regeneration, simultaneously reflecting the processes of substitution cytogenesis.

[Structural changes and cellular composition of the mesenterial lymph nodes in mice of first generation after parental exposure to radiation].

Changes of the structure and cellular composition of mesenterial lymph nodes were studied in 93 outbred albino mice born from parents exposed to 0.3 and 3.0 Gy of the ionizing radiation, after single intraperitoneal immunization of the offspring with sheep erythrocytes. The changes (lymphoid tissue hypoplasia with the reduction of lymphocyte and plasma cell numbers, increase of apoptotic cell, macrophage and reticular cell numbers, as well as cell detritis volume) were more pronounced after an exposure to high-dose radiation. The outgrowth of node stroma, circulatory disturbances and tissue edema were observed. The processes of lymphoid tissue reduction in the cortex affected the medullary structure, finally resulting in the early lymph node involution, that reflected the changes in the general adaptation and defense reactions of the whole immune system.

[Mandibular bone tissue regeneration after the introduction of the implantation system performed on the basis of carbon composite material].

The purpose of this study was to investigate the processes of regeneration of bone tissue after the introduction of new implant systems. In the experiment, performed on 10 male pigs of Landras breed aged 50-55 days and weighing 17-18.5 kg, the time course of histological changes was studied in the area of mandibular regeneration after the formation of tissue defect and the introduction of the implant of a proposed construction. Morphological analysis of the experimental results 90, 180 and 270 days after the operation demonstrated the process of reparative regeneration of damaged bone along implant-bone block boundaries. Bone repair proceeded through the stage of formation of the woven bone with its progressive substitution by the lamellar bone, with the maintenance of the shape, size and symmetry of the damaged organ.

[Dysregulation of autonomic, hypophysis-adrenal and immune systems in patients with severe brain injury].

Thirty-three patients were studied in the acute stage of severe brain injury, 18 patients died during 24 days in a hospital, 15 patients had survived. The functional status of autonomic, hypophysis-adrenal and immune systems was followed up using variation cardiointervalography, Adrenocorticotropic hormone (ACTH) and cortisol as well as cell immunity parameters were measured. In patients with a fatal outcome, the overstrain of compensatory mechanisms of autonomic supply (mode amplitude, AMo and index of strain, IS) noted in the first day was exhausted to 19-22 days. The hyperreactivity of the adrenocorticoid system was characteristic of all patients. The wavelike character of the changes in mean concentration of cortisol, along with the decrease in ACTH, was observed in patients with a fatal outcome while cortisol and ACTH gradually decreased in survived patients. In patients with a fatal outcome, the helper-induction activity was dramatically inhibited after the short-term elevation. These parameters were correlated with the dynamics of mortality: the first peak of mortality was at the first week, along with the overstrain of the autonomic-endocrine regulation; the second peak was at 21-26 days, it was associated with a sharp reduction of hormone production, "immunological pit" and an exhaustion of the adaptive-compensatory mechanisms of the autonomic nervous system.

[The morphometric analysis of serotonin granules of platelets in migraine].

The serotonin hypothesis of migraine attack is based on a phenomenon of fast and significant decreasing of serotonin granules in blood platelets. The morphometric analysis was used to study area, diameter, length and wideness of platelet serotonin granules in 20 migraine patients during a headache attack and in an interparoxysmal period. We found that the area of serotonin granule surface in platelets was 0.231 +/- 0.595 mcm during the migraine attack that was significantly higher than that during the interparoxysmal period (0.205 +/- 0.037 mcm) and in the platelets of healthy controls (0.190 +/- 0.028 mcm) (n = 10). The study has shown that during migraine attack serotonin granules are undergone also structural changes.

[Dynamics of parameters of autonomous regulation, humoral immunity and neuroendocrine system in acute brain injury with fatal outcome].

Twenty-two patients with brain injury who died within 24 days after admission to the hospital were studied. Autonomous regulation was studied using a method of variation cardiointervalography (VCIG), humoral immunity - by a method of gel radial immunodiffusion, contents of adrenocorticotropic hormone (ACTH) and hydrocortisone - by a radioimmune method. VCIG registration and blood sampling were carried out in the morning in 1-3, 4-6, 7-10, 11-14, 15-18 and 19-22 days after admission to the hospital. A control group included 10 healthy people. A comparison group consisted of 15 patients survived after the severe brain injury. In patients with the fatal brain injury, the duration of adrenocortical stage was on average 3 weeks that was comparable to the parameters of survived patients. The immunological reactions were characterized by relatively higher concentrations of immunoglobulins in the first days of admission. In the following days, their levels fell down. The death occurred mostly in the 1st week when the levels of ACTH and cortisol in the peripheral blood and parameters of sympatic tone were maximal that might indicate the overstrain of autonomous and endocrine systems and in the 19-22 days in the period of the dramatic reduction of hormone production (immunological hole) and exhaustion of adaptive-compensation mechanisms as revealed by VCIG data.

[Morphofunctional features of 10-12-day-old rabbit lymphoid tissue]. / Morfofunktsional'nye osogbennosti limfoidnoi tkani u krolikov 10--12-dnevnogo vozrasta.

Histological, cytological, enzymatic (acid and alkaline phosphatase, SDG and alpha-GPhDG), immunomorphological (RNA, DNA, amount of T- and B-lymphocytes) peculiarities in structure of the lymphatic system organs have been studied in 10-12-day-old rabbits. It has been stated that T-lymphocytes predominant (in total amount) among the lymphoid cells in the organs; there is an essential amount of inactive cells. Besides, the activity of the hydrolytic enzymes is greater than that of the mitochondrial ones. Lymphatic follicles and T-zones in the organs are poorly developed, light centers, as a rule, are not formed, diffuse lymphoid tissue predominates.