Aim - to study the correlation between the thickness of the fibrous cap and collagen in the coronary and carotid plaques in patients with myocardial infarction. Materials and methods. The objects of the study were 81 coronary and carotid atherosclerotic plaques obtained during autopsy study of 15 patients who died from complications of myocardial infarction. Histological and morphometric study and immunohistochemistry were performed. Immunohistochemical examination was carried out using monoclonal antibodies against collagen types II, III, IV, VI, VII. Results. There is a combination of complicated, unstable and stable coronary and carotid atherosclerotic plaques in patients with myocardial infarction. Unstable atherosclerotic plaque is characterized by thinning of the fibrous cap mainly in the peripheral areas and the growth of destructive changes in the collagen types III, IV and VI. Conclusion. There is a critical thinning in the caps of unstable carotid and coronary plaques in myocardial infarction with signs of disorganization of collagen, leading to decreased resistance to mechanical stress of this type of plaques.

Aim - to study the reparative regeneration processes after experimental gradual traction of cervix uteri in rats. Materials and methods. The object of the study is the cervix at the sphincter. We performed gradual traction of cervix uteri in 25 rats under aether anesthesia and gathered the samples.We analyzed the course of reparative regeneration and performed sampling after 1, 3, 5, 7, 10, 15, 21 and 30 days. We carried out complex morphological examination with optical and transmission electron microscopy, and immunohistochemistry. The immunohistochemical examination of cervical tissues was performed using a set of monoclonal antibodies to а-smooth muscle actin. Results. It was determined that cervical traction formed three distinguishable zones: the zone of damage, the periwound zone and the zone of morphological integrity. The zone of damage corresponds to the actual sphincter and the periwound zone - to pre- and postsphincteral compartments. Several myocytes undergo necrosis in the damage zone. There is no necrosis in the periwound area, but we found some abnormality of intercellular contacts due to the change of the morphology of intercellular substance. The experimental traction causes the development of local septic inflammation, affecting all the layers. The synthesis of fibrous connective tissue components starts in the proliferative phase. It leads to restructuring of histoarchitecture and disruption of the functional syncytium structure. Conclusion. Post-traumatic regeneration is performed by changing the phenotype of survived myocytes from mantle to mantle-synthetic myocytes with synthesis of the fiber component of the intercellular substance. Also, there is an incomplete mitosis in several myocytes, which leads to the formation of binuclear or polyploid cells.