Morphological Features of the Ascending Aorta Remodeling and Activation of Regeneratory Potential in Intima when Forming Aneurysm.

In patients with an ascending aorta aneurysm, restructuring of all its layers and, first of all, the intima and media was revealed. The thickness of the intima was 79.3±63.1 µm in patients with aortic diameter <55 mm (group Ao<55) and 162.7±177.4 µm (p<0.05) in patients with aortic diameter ⩾55 mm (Ao⩾55 group), the thickness of the aortic media was 1184.0±198.2 and 1144.3±288.4 µm, respectively. In patients of the Ao<55 group, aortic dilatation was accompanied by compensatory thickening of the inner and middle layers of the aorta. In the Ao⩾55 group, thinning of the aortic media, fragmentation of elastic fibers, and its cystic degeneration were revealed. c-kit+ Stem cells were detected in the subendothelium of the thickened intima of the dilated ascending aorta. The appearance of c-kit+ cells correlated with intimal remodeling and its colonization with CD34+ and CD44+ myofibroblast-like cells.

[Altered Z-disks of myofibrils in the cardiomyocytes from patients with Ebstein's anomaly].

UNLABELLED: The aim of the study was to examine the peculiarities of the changes in Z-bands of myofibrils in the cardiomyocytes from patients with Ebstein's anomaly. MATERIAL AND METHODS: Electron microscopy assay of intraoperative biopsies of the right heart chambers in 41 patients aged from 9 months to 57 years was performed. RESULTS: Some patients exhibited Z-disk alterations of two types in individual cardiomyocytes, namely: local symmetrical bead-like expansions of Z-disks or longitudinal deposits of Z-material of different lengths along the myofibrils. Z-disk alterations were more common in atrial cardiomyocytes than in the ventricle. The presence of Z-disk alterations in the cardiomyocytes correlated with a number of clinical parameters. In particular, the occurrence of longitudinal deposits of Z-material in atrial cardiomyocytes directly correlated with the manifestation of the Wolff-Parkinson-White syndrome in the patients. CONCLUSIONS: Above characteristic ultrastructural changes in Z-bands of myofibrils in the cardiomyocytes from patients with Ebstein's anomaly have a certain similarity to Z-band diseases in skeletal muscle at sarcomeric protein gene mutations described in the literature, which suggests the mutations in the genes of proteins included in Z-bands of myofibrils in the cardiomyocytes from patients with Ebstein's anomaly.