Loss of Myofibrils in Cardiomyocytes as a Morphological Indicator of Reduced Compensatory Capabilities of Hypertrophied Myocardium.

The functioning of the ventricular myocardium in hypertrophic cardiomyopathy (HCM) under high hemodynamic load leads to depletion of its resources and is associated with the risk of developing a dilated stage. In patients with HCM, the cardiomyocytes of the interventricular septum are hypertrophied, the proportion of cardiomyocytes in which myofibrils constitute less than 50% of the sarcoplasm volume increases with increasing the cardiomyocyte length and correlates with echocardiographic signs of left ventricular obstruction. These cardiomyocytes are characterized by ultrastructural signs of synthetic activity.

[Morphology of the myocardium of the interventricular septum in children with hypertrophic cardiomyopathy].

Objective: To carry out a comparative analysis of the morphology of the interventricular septum (IVS) myocardium in children with hypertrophic cardiomyopathy (HCM) and without cardiovascular pathology.

Material And Methods: A study of myocardial biopsies of the IVS in children with HCM (=18, 1.2-17 years) and children without cardiovascular pathology (=11, 1-16 years) was carried out.

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.

Accelerated Growth, Differentiation, and Ploidy with Reduced Proliferation of Right Ventricular Cardiomyocytes in Children with Congenital Heart Defect Tetralogy of Fallot.

The myocardium of children with tetralogy of Fallot (TF) undergoes hemodynamic overload and hypoxemia immediately after birth. Comparative analysis of changes in the ploidy and morphology of the right ventricular cardiomyocytes in children with TF in the first years of life demonstrated their significant increase compared with the control group. In children with TF, there was a predominantly diffuse distribution of Connexin43-containing gap junctions over the cardiomyocytes sarcolemma, which redistributed into the intercalated discs as cardiomyocytes differentiation increased.

Morpho-functional changes of cardiac telocytes in isolated atrial amyloidosis in patients with atrial fibrillation.

Telocytes are interstitial cells with long, thin processes by which they contact each other and form a network in the interstitium. Myocardial remodeling of adult patients with different forms of atrial fibrillation (AF) occurs with an increase in fibrosis, age-related isolated atrial amyloidosis (IAA), cardiomyocyte hypertrophy and myolysis. This study aimed to determine the ultrastructural and immunohistochemical features of cardiac telocytes in patients with AF and AF + IAA.

Telocytes in the Myocardium of Children with Congenital Heart Disease Tetralogy of Fallot.

Telocytes, a new type of interstitial stem cells with long thin processes that form a three-dimensional network around cardiomyocytes, vessels, and nerve fibers were described in the myocardium of children with tetralogy of Fallot. Two types of morphologically different telocytes, spindle-shaped and rounded, were identified. Contacts of telocytes with stem cells and interstitial macrophages were found.

[Hypertrophic cardiomyopathy. Cardiomyocyte ultrastructure, the specific or stereotypic signs].

Unlabelled: Hypertrophic cardiomyopathy (HCM) is a congenital disease caused by mutations in a number of sarcomere proteins. According to the type of mutation, clinical observations record similar clinical manifestations, myocardial pathological changes, and the timing of manifestation of the disease in HCM patients.

Objective: To study cardiomyocyte (CMC) ultrastructural changes in the interventricular septum (IVS) of patients with HCM and evaluate their specificity for this pathology.

[Ultrastructural features of cardiomyocytes in infants with tetralogy of Fallot in the first year of life].

Objective: To analyze cardiomyocyte (CMC) ultrastructural changes in the right ventricle outflow tract (RVOT) of infants with tetralogy of Fallot (TF) in the first years of life and to compare the findings with clinical parameters in these patients.

Material And Methods: Intraoperative RVOT myocardial biopsy specimens obtained from 51 patients aged 3-33 months with TF during radical correction of defect were investigated. CMC diameter and length were measured using the semithin myocardial sections stained with periodic acid-Schiff.

Ultrastructural and Immunohistochemical Features of Telocytes in Placental Villi in Preeclampsia.

A new cell type, interstitial Cajal-like cell (ICLC), was recently described in different organs. The name was recently changed to telocytes (TCs), and their typical thin, long processes have been named telopodes (Tp). TCs regulate the contractile activity of smooth muscle cells and play a role in regulating vessel contractions.

[Morphological Features of Mesenhymal Stroma Cells of Chorionic Villi].

Background: Nowadays autologous mesenchymal placental stromal cells (MSCs) may use to treat for various diseases both of the mother and the child. Stroma of the placenta villi is appropriated origin for cell culture isolation.

Aim: of the study was to evaluate the possibility for selection and use of placental tissue for mesenchymal stromal cells.

[Morphological features of the myocardium of the atrial appendages in patients with different forms of atrial fibrillation].

Aim: to analyze the morphological features of the myocardium of the atrial appendages in patients with different forms of atrial fibrillation (AF) and to compare the findings with the clinical parameters of patients.

Material And Methods: Light and electron microscopies were used to examine the myocardium of the atrial appendages in adult patients with paroxysmal (PAF), persistent (PrAF), or long-standing persistent atrial fibrillation (LPAF) and in comparison group patients with sinus rhythm without history of AF. A morphometric method was employed to evaluate myocardial fibrosis and to measure the diameter of cardiomyocytes (CMCs); the degree of lipomatosis and amyloidosis was semiquantitatively determined; and the content of CMC myofibrils was estimated.

Ultrastructural Characteristics of Placental Telocytes.

Telocytes of placental villi were studied by electronic microscopy during physiological pregnancy. Ultrastructural features of telocytes indicating their heterogeneity and presence of at least three types of villi depending on their localization and kind were observed. All placental telocytes were characterized by small amount of organelles including mitochondria.

Proliferative Potential of Cardiomyocytes in Hypertrophic Cardiomyopathy: Correlation with Myocardial Remodeling.

Proliferating Ki-67 cardiomyocytes were detected in the interventricular septum myocardium of adult patients with hypertrophic cardiomyopathy. In the same patients, the severity of hypertrophy and the degree of cardiomyocyte differentiation were assessed by the content of myofibrils, ultrastructural morphology, and the pattern of connexin 43-containing gap junction distribution. Adult Ki-67 cardiomyocytes containing sarcomeric α-actin (sarc α-act) in the sarcoplasm (diameter 23.

Isolated Atrial Amyloidosis in Patients with Various Types of Atrial Fibrillation.

The myocardium of the right and left atrial appendages (auricles) in patients with paroxysmal, persistent, and permanent forms of atrial fibrillation was examined by histological methods and electron microscopy. Isolated atrial amyloidosis was detected in the left (50.0-56.

Age-Related Features of Cardiomyocyte Ploidy in Patients with Hypertrophic Obstructive Cardiomyopathy.

Endomyocardial biopsy samples of the interventricular septum from patients with hypertrophic cardiomyopathy isolated during myectomy were examined. We revealed significant variability of cardiomyocyte ploidy (from 2.9c to 13.

Resident cardiomyocyte precursor stem cells in the myocardium of infants of the first two years of life with tetralogy of Fallot.

We studied the content of resident myocardial stem cells, cardiomyocyte precursors, in myocardial biopsy specimens from the right ventricular outflow tract of patients of the first two years of life with tetralogy of Fallot. Myocardial resident stem cells were detected by the method of confocal immunohistochemistry using antibodies to c-kit and sarcomeric α-actin. The diameter of right ventricular cardiomyocytes was measured; the presence of myolysis zones was semiquantitatively evaluated.

[Cardiomyocyte structural rearrangement in patients with dilated cardiomyopathy and valvular heart disease].

Light and electron microscopies were used to analyze cardiomyocyte structural changes in the dilated left ventricle in patients with dilated cardiomyopathy and valvular heart diseases. The patients were found to have cardiomyocyte hypertrophy and ultrastructural rearrangement with a tissue-specific reduction. There was hypertrophic cardiomyocyte lengthening that continued after these cells stopped growing thicker, as well as occurred due to the loss of myofibrils, which increased during the cell rearrangement, and directly correlated with the lower ejection fraction and higher end-systolic volume of the left ventricle.

Resident stem cells in the myocardium of patients with obstructive hypertrophic cardiomyopathy.

Interventricular septum myocardium was studied in 40 patients with obstructive hypertrophic cardiomyopathy. Immunohistochemical assay revealed c-kit-positive resident cardiac stem cells in 82.5% patients.

[Features of cardiomyocytes structural changes in patients with postinfarction aneurism and reduced myocardial contractility of the left ventricle of the heart].

Cardiomyocytes (CMC) of 18 patients with both ischemic heart disease, aneurism of the front wall and reduced myocardial contractility of the left ventricle (LV) were hypertrophied and in state of chronic hibernation, which was characterized by weakening of tissue-specific signs. Widening of lack myofibrils' zones and in part gap junction of intercalated disk transfer on the side of cells was found The hypertrophy of CMC had positive correlation, but chronic hibernation - negative one with the volume of LV. The worse prognosis of clinical course was degenerative changes of hibernate CMC with accumulation of autophagosomes that correlated with increasing of LV sphericity index.

[Peculiarities of morphology and mechanisms of pathogenesis of hypertrophic cardiomyopathy].

Understanding the molecular basis and cell mechanisms, clinical course, and treatment of hypertrophic cardiomyopathy (HCMP) has progressed substantially in the last decade. The majority of genetic mutations associated with HCMP occur in genes encoding sarcomeric proteins, which are expressed only in cardiomyocytes. The spectrum of morphological features of HCMP includes: hypertrophy of myocardium, myocardial disarray, interstitial fibrosis, mitral valve abnormalities, and microvascular remodeling, is indicative of the involvement of other cell lineages.

Destructive effect of DNA topoisomerase II inhibitor vepesid on mouse spermatogenesis.

Inhibition of DNA topoisomerase II with vepesid induced structural and functional reorganization of chromatin in meiotically dividing spermatocytes I, which later led to the block of their differentiation and long-lasting disorders in spermatogenesis. Vepesid induced decondensation of spermatocyte I chromatin, block of desynapsis, and elongation of lateral elements of spermatocyte autosome synaptonemal complexes during late pachytene and diplotene of meiosis. This confirms the involvement of type II DNA topoisomerase in chromatin condensation and homologous chromosome desynapsis at the stage of diplotene and the role of this enzyme in structural organization of the synaptonemal complex.

Damaging effect of taxol on mouse spermatogenesis.

Taxol produced a specific effect on mouse spermatocytes I and on stem spermatogonia, which leads to overall degeneration of spermatocytes I and long lasting disorders of spermatogenesis. Breaks of the axial and lateral elements of the synaptonemal complex, aneuploidies in spermatocytes in early, middle, and late pachytene, and accumulation of cells with associations of sex chromosomes and autosomes were observed, which attested to blockade of spermatogenesis in late pachytene and diplotene of meiosis prophase I. Mesna, a chemoprotective agent, reduced total toxicity and lethal effects of taxol, but did not prevent destruction of the testes.