[Age-related changes of the pituitary folliculo-stellate cells in rats in chronic stress].

UNLABELLED: Folliculo-stellate cells are known as S-100 protein immunopositive cells of the anterior lobe of pituitary gland which are not secreting hormones and are presumed to be organ specific stem cells of the adenohypophys. Their role in adaptation of the body to stress remains unclear. AIM: To evaluate dynamics of folliculo-stellate and hormone-producing cells in rats of different age in chronic stress exposure. MATERIALS AND METHODS: Sprague-Dawley rats aged 1, 3, 6 and 12 months were exposed to chronic immersion immobilization stress. Histological section of the pituitary glands were stained immunohistochemically with subsequent image analysis. RESULTS: In control rats S-100 protein-immunopositive cells increased in number with age and negatively correlated with the number of ACTH-positive cells. In experimental animals aged 1 and 3 months volume density of S-100 protein-immunoreactive cells significantly decreased and negatively correlated with ACTH-positive cells, while in 6 month old rats it was only slightly decreased and in 12 months old animals showed tendency to increase. CONCLUSIONS: Results of the study demonstrating capacity of the folliculo-stellate cells to contribute to the plasticity of the hypothalamo-hypophyseo-adrenal axis in chronic stress exposure at different age.

[Immunohistochemical characteristics of the spleen under the effect of various types of stressors].

The effect of different types of stressors (physical and psychoemotional) on the splenic immunoarchitecture in prepubertal Sprague-Dawley rats was evaluated using the quantitative immunohistochemical methods. Rats aged 1 month were exposed to chronic stress for 5 hours daily during 7 consecutive days. After the last stress session, animals were sacrificed, spleen was obtained for weighing and processed for routine histology and immunohistochemistry (CD3, CD8, CD90, CD20, ED1, PCNA, caspase-3) with subsequent computer image analysis. The results obtained demonstrated that the range of stress-induced immunosuppressive changes in the splenic compartments was associated with the type of stressor. Chronic exposure to purely psychological stress resulted in the decreased volume of the splenic white pulp associated mainly with the reduction of T-cell subcompartments with the decrease in their cellularity and the reduction of volume density of CD90+ and CD8+ cells in them compared to those in age-matched control animals, while the physical stressor affected both T- and B-subcompartments of the white pulp causing the reduction of lymphoid nodule volume, marginal zone width and volume density of CD20+ cells. Hypoplasia of the splenic B-zones was mainly associated with increased splenocyte apoptotic rate while that of the T-zones--with decreased proliferation rate and attenuated traffic of the recent thymic immigrants into the spleen.

[Immunohistochemical characteristics of the hypophysis under normal and stress-associated conditions].

Quantitative immunohistochemical investigation was undertaken to detect the peculiarities of the activation of the hypothalamic-hypophyseal-adrenocortical system at the level of its central unit--the adenohypophysis--in the growing organism under the conditions of chronic exposure to psycho-emotional stressors of varying intensities. Sprague-Dawley rats aged 30 days were exposed to either mild or severe chronic restraint stress for 5 hours during seven consecutive days. After the last exposure to stress, rats were decapitated, the endocrine glands (pituitary and adrenal glands) were removed, weighted, and embedded in paraffin; histological sections were stained with hematoxylin and eosin. Sections of hypophysis were also stained immunohistochemically using the monoclonal antibodies against adrenocorticotropic hormone (ACTH) and proliferating cell nuclear antigen (PCNA) with subsequent image analysis. The results of the study suggest that the stress-related hyperplasia of corticotropocytes in the hypophyseal pars distalis of the peripuberal rats was mainly associated with differentiation of the immature precursor cells of the hypophysis rather than with the increased cell proliferation.

[Accidental thymic involution in the growing body under the effect of different types of stressors].

Using the quantitative immunohistochemistry, the immunomodulatory effect of different types of stressors (physical and psychoemotional) on the thymus of growing experimental animals was assessed. Sprague-Dawley rats aged 21 day were exposed either to physical (water immersion) or emotional "expectation" stress for 5 hours daily during 7 consecutive days. After the final exposure to stress, animals were sacrificed, thymus was obtained for weighting and was processed for routine histology and immunohistochemistry (CD3, CD8, ED1, PCNA) with subsequent automatic image analysis. The finding obtained have demonstrated severe accidental thymic involution in both groups of experimental animals, which was more prominent under the effect of the physical stressor as compared to "purely" psychoemotional stressor. The major factors of poststress thymic hypoplasia were the increased apoptosis of the cortical thymocytes and inhibition of their proliferation, but not their increased transport to peripheral immune organs.

[Morphometric evaluation of the microcirculatory bed of the synovial membrane in rheumatoid arthritis using automatic image analyzer]. / Morfometricheskaia otsenka sosudov mikrotsirkuliatornogo rusla sinovial'noi obolochki pri revmatoidnom artrite s primeneniem avtomaticheskogo analizatora izobrazhenii.

Automatic analysis of the image makes objective assessment of the morphological picture of pathological processes much easier. The authors subjected only vascular changes to such an objective assessment. The picture of rheumatoid synovitis as a whole, i.e. including changes in their layers, nature and extent of infiltration can be subjected to the same analysis. This requires elaboration of more intricate programs or a more complex procedure of the analysis with due regard for all sings reflecting exudative and proliferative processes in all the components of the synovial tissue.

[The semiquantitative characteristics of the ultrastructural changes in the vessels of the microcirculatory bed of the synovial membrane in different clinical variants of rheumatoid arthritis]. / Polukolichestvennaia kharakteristika ul'trastrukturnykh izmenenii sosudov mikrotsirkuliatornogo rusla sinovial'noi obolochki pri razlichnykh klinicheskikh variantakh revmatoidnogo artrita.

Electron microscopy was used to make semiquantitative evaluation of lesions in the microvessels of the synovial membrane in patients with rheumatoid synovitis of different duration, different activity of the disease, joint and systemic form of rheumatoid arthritis, in seronegative and seropositive tests of rheumatoid patients. The synovial biopsy from patients with posttraumatic arthropathy without any clinical and morphological manifestations of synovitis served as control. Frequency of different ultrastructural changes in the vessel wall was statistically evaluated. Significant differences in the submicroscopic picture of microcirculatory lesions in immediate and late rheumatoid synovitis were discovered. Frequency and depth of destructive changes in the vessel wall persisted in the increased activity and appearance of systemic manifestations of the disease.

[Morphofunctional changes in the microcirculatory bed of the synovial membrane in antigen-induced arthritis]. / Morfofunktsional'nye izmeneniia mikrotsirkuliatornogo rusla sinovial'noi obolochki pri antigennom artrite.

Ultrastructural changes of synovial capillary and venule wall have been investigated in rabbits with antigen-induced arthritis, with the permeability of microcirculatory bed determined using 99mTc pertechnetate. The correlation between the incidence of ultrastructural microvascular damages in exudative phase of arthritis and the increased permeability has been established. Ultrastructural changes occurring in proliferative phase of arthritis are considered as adaptive to conditions of increased permeability.