[Psychophysiologic indications in the students with different adaptation grade during examination period].

There are different changes in psychophysiologic behavior of the students with different adaptation grade to examination stress. Examination stress in the students with a low adaptation grade resulted in increase of response against a background of reduction of attention. The lowest changes in the indications studied have been observed in a group of students with an average adaptation degree. They demonstrated a reduced attention due to tiredness after their examinations. Statistically significant changes of these parameters have been also observed in the students with a high adaptation grade both before and after examinations. The extreme indexes of the psychic adaptation grade did not manifest their stability that leads to some changes in the psycho-physiologic state of the students in stress situations.

Cardiomyocyte ultrastructure in rats with different metabolizing capacities of the liver during acute myocardial infarction.

Electron microscopy of cardiomyocytes was performed on days 1, 3, and 7 after ligation of the coronary artery in rats previously divided according to liver metabolizing capacities into slowly and rapidly metabolizing animals. In rapidly metabolizing rats cardiomyocyte sarcoplasm contained large number of hyperplastic ribosomes and polysomes at the late stages of experiment, which attested to high activity of protein and RNA synthesis compared to slowly metabolizing rats. In slowly metabolizing animals edema of cardiomyocyte sarcoplasm and mitochondria was usually seen.

[Morphological characteristics of cardiomyocyte death in the experimental myocardial infarction in rats with various emotional reaction]. / Morfologicheskaia kharakteristika gibeli kardiomiotsitov pri éksperimental'nom infarkte miokarda u krys s raznoi émotsional'noi reaktsiei.

The peculiarities of morphological signs of cardiomyocyte death in the lesion focus in experimental myocardial infarction were studied. Infarction was induced by ligation of descending branch of the left heart coronary artery in outbred rats with 180-200 g body mass, which were previously subdivided into highly emotional (HE) and low emotional (LE) groups according to "open field" test. Microscopic study has shown that in the infarction focus of animals of both HE and LE groups cardiomyocyte death types were found that differed primarily by the state of myofibrils. Relaxation and contracture types of cardiomyocyte death were typical to HE animals, while lytic cardiomyocyte necrosis prevailed in LE group.

Morphological changes in myocardium in rats with different resistance to hypoxia after ligation of the coronary artery.

We studied morphological changes in the myocardium during experimental myocardial infarction in rats with different resistance to hypoxia. Microscopic examination showed that morphological changes in the ischemic zone and adjacent tissues are different in rats with high and low resistance to acute ischemia. In highly resistant rats, necrotic changes in cardiomyocytes included focal contracture and loosening. These changes were followed by the formation of focal necroses with well-defined boundaries, dense demarcation infiltrates, and pronounced hypertrophy of cardiomyocytes in the adjacent tissue. In low resistant rats, pronounced edema in the ischemia zone and numerous hemorrhages in the interstitial tissue developed in the early stage after coronary occlusion. These changes were followed by the formation of more extensive necrotic areas with diffuse boundaries, less pronounced demarcation, and irregular hypertrophy of cardiomyocytes in the surrounding tissue.