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. Although the placenta is not an innervated organ, we believe that TCs are present in the placenta. We studied placenta samples from physiological pregnancies and in different variants of preeclampsia (PE). We examined these samples using light microscopy of semi-thin sections, transmission electron microscopy, and immunohistochemistry. Immunohistochemical examination was performed with primary antibodies to CD34, CD117, SMA, and vimentin, and TMEM16a (DOG-1), the latter was used for the diagnosis of gastrointestinal stromal tumours (GIST) consisting of TCs. We have identified a heterogenetic population of ТСs in term placentas, as these cell types differed in their localization, immunophenotype and ultrastructural characteristics. We assume TMEM16a could be used as the marker for identification of TCs. In PE we have revealed telocyte-like cells with ultrastructural signs of fibrocytes (significant process thickening and the granular endoplasmic reticulum content was increased) and a loss of TMEM16a immunohistochemical staining.

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. The number of Ki67-positive cardiomyocytes varied greatly and amounted to 7.0–1025.5/10⁶ cardiomyocytes and also were decreased with increased myocytes differentiation. Ultrastructural signs of immaturity and proliferative activity of cardiomyocytes in children with TF were demonstrated. The proportion of interstitial tissue did not differ significantly from the control group. The myocardium of children with TF under six months of age was most sensitive to hypoxemia, it was manifested by a delay in the intercalated discs and myofibril assembly and the appearance of ultrastructural signs of dystrophic changes in the cardiomyocytes. Thus, the acceleration of ontogenetic growth and differentiation of the cardiomyocytes, but not the reactivation of their proliferation, was an adaptation of the immature myocardium of children with TF to hemodynamic overload and hypoxemia.

The aim. To carry out a comparative morphological characteristic of the uteroplacental area with abnormal placentation – pl. accreta, pl. increta, pl. percreta. Materials and methods. The study included 47 patients with atypical placentation; the comparison group included 10 healthy pregnant women with uterine scar after a previous caesarean section. A histological study of uteroplacental area samples was performed with hematoxylin and eosin, methylene blue staining. An immunohistochemical study with primary antibodies to cytokeratin 7 (CK7), Hif2a, vascular endothelial growth factor, α-SMA was carried out. The differences between the compared values were considered to be statistically significant at p < 0.05. The results of the study. Pl. accreta was determined in 12 (25.5 %), pl. increta – in 30 (63.9 %), pl. percreta – in 5 (10.6 %) patients. In all patients of the main group, the decidua was completely or partially absent in the area of abnormal placentation or was replaced by an uneven layer of fetal fibrinoid. Cases when placental villi unevenly penetrated into the thickness of myometrium in the form of “tongues” or “coves” bordered by fetal fibrinoid and often located intermuscularly were defined as pl. increta (n = 26). Cases with the placental villi ingrowth to the serous membrane were considered as pl. percreta (n = 5). In cases with deep variants of ingrowth (pl. increta and pl. percreta) (n = 31), the villi were visualized in the lumen of the vessels and the thinning of the lower uterine segment with the presence of stretched muscle bundles was revealed. Aseptic necrosis of the myometrium was found: in 2 (16.7 %) of 12 women with pl. accreta, in 26 (86.7 %) of 30 women with pl. increta and in 5 (100 %) women with pl. percreta. There were no areas of necrosis in the myometrium of the women of comparison group. Conclusion. The appearance and increase of myometrial necrosis zones in response to an increase in the depth of placental villus ingrowth were detected. Myometrial necrosis zones could be the cause of activation of angiogenic factors and an important stimulus for the development of abnormal vascularization in placenta accreta spectrum.

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. Materials and methods: The present study was based on 45 placental samples of women aged 27−38 yy. who underwent surgical delivery at 36−40 weeks of gestation. 30 of these women have been enrolled in the basic group including children with congenital abnormalities (CA). The comparison group consisted of 15 patients with physiological pregnancy. We performed histological examination (with hematoxylin and eosin staining), immunohistochemical examination (with use monoclonal antibodies CD90 (1:25; Abcam, UK), СD105 (1:500; Abcam, UK), CD44 (1:25; Dako), СD73 (1:200, Abcam, UK), and electron microscopy (by microscope Philips/FEI Corporation, Eindhoven, Holland). Eclipse 80i microscope (Nikon Corporation, Japan) was used to examine the immunohistochemical reactions as a brown staining. The evaluation of the intensity of reaction was conducted by NIS-Elements Advanced Research 3.2 program (Czech Republic). Student’s t-test and analysis of variance were used to compare the mean values. Differences were considered statistically significant at p0.05. Results: Interstitial cells of the stroma of the villi with CA had fibroblastic differentiation as revealed degenerative changes of the cells. The histologic examination with hematoxylin and eosin staining revealed significant fibrosis of the stroma of the placenta villi in CA group (p0,01). Immunohistochemical study of stem and intermediate chorionic villi revealed no significant differences in staining of CD44+, СD90+, СD73+, and CD105+ cells if compared to the control group (p0.05). Although CD105 expression was significantly lower in the CA group (0.058±0.0049) than in the control group (0.088±0.0039) (p0.05). However, electron microscopy detected the villi interstitial stromal cells with fibroblastic differentiation in CA group. Conclusions: Thus, it is necessary to exclude placenta with obstetrical history, somatic, and congenital pathology of the mother and the child when selecting the placental cell culture. Moreover, choosing a sample the morphological structure of the placenta should be taken into consideration. However, congenital malformations of the fetus, pathology of the mother cultivate mesenchymal stromal cells of placentas is inappropriate and should be taken advantage of the donor cells.

Introduction. Aortic aneurysm is characterized by aortic diameter expansion by 1.5 or more times and can lead to dissection and rupture of the aortic wall with fatal consequences. The aim of the study was to compare changes in the morphology of the ascending aorta wall in patients with bicuspid and tricuspid aortic valves (BAV and TAV, respectively) having an aortic aneurysm. Materials and methods. We examined biopsies of the ascending aorta with an aneurysm in 49 patients with BAV and 99 patients with TAV. Results. The diameter of the ascending aorta was 51.0±9.1 mm in patients with BAV and that in individuals with TAV was 54.6±11.5 mm. Morphometric study of aortic wall layers demonstrated a significant thickening of the intima (71.7±52.3 and 143.5±148.1 μm, respectively) and adventitia of the aorta (595.9±253.9 and 801.3±388.6 μm, respectively) [p<0.05], while the thickness of the media was almost the same (1127.0±246.9 and 1177.9±268.32 μm, respectively). Changes in the aortic media (fragmentation of elastic membranes, disruption of the parallel arrangement of smooth muscle cells, and density of vasa vasorum) were significantly less frequent in patients with BAV. Patients with BAV required surgery at a younger age than those with TAV, although they showed less pronounced signs of remodeling of aortic intima and media. Conclusion. Patients with BAV necessitate surgery when having less pronounced changes in the morphology of the ascending aortic wall. Construction of a stereometric model of histological changes in the aortic wall in an aortic aneurysm will allow us to quantitatively represent the role of key morphological characteristics, simplify pathological diagnosis, and optimize surgical management for patients with BAV. Keywords: bicuspid aortic valve, tricuspid aortic valve, aortic aneurysm, aortic intima, aortic medi

BACKGROUND: Intercellular gap junctions play a special role in the biology of cellular interactions. Their structural and dispositional changes can affect some biological functions, including disruption of electrical pulse propagation, which is primarily important for myocardial function. AIM: The aim was to evaluate the morphological characteristics and localization of connexin 43-containing (Cx43+) gap — junctions and to determine their association with changes in myocardial morphology of the interventricular septum and clinical parameters in patients with hypertrophic cardiomyopathy. MATERIALS AND METHODS: Morphometry and immunohistochemistry of interventricular septal myocardium were performed in patients with hypertrophic cardiomyopathy (n = 62, aged 18 to 61 years) compared with subjects without cardiovascular disease (n = 8, aged 25 to 54 years). Resection of the interventricular septum of the right ventricle was performed in patients with hypertrophic cardiomyopathy. Cx43+ gap junctions were identified in cardiomyocytes and their location and ultrastructural arrangement were determined. The data obtained were compared with clinical parameters of patients with hypertrophic cardiomyopathy. RESULTS: In the interventricular septal myocardium of patients with hypertrophic cardiomyopathy, a redistribution of Cx43+ gap junctions from intercalated discs to the lateral surfaces of cardiomyocytes was observed. Gap junction changes are more frequent and more extensive in patients with hypertrophic cardiomyopathy than in the control group. They are typical of patients with the most severe morphological and functional cardiac condition, as evidenced by echocardiographic data such as significant thickening of the interventricular septum and a decrease in the volume of the left ventricular cavity. Morphologically complex remodeling of the myocardium is manifested by hypertrophy of the cardiomyocytes and partial loss of their myofibrils. Ultrastructurally, 28.1% of patients with hypertrophic cardiomyopathy had gap junction defects in the myocardium such as sites of localized divergence of intercalated disc membranes and abnormal ring structures formed by invaginations of gap junction-containing sarcolemma. CONCLUSION: The location of Cx43+ gap junctions on the lateral surfaces of cardiomyocytes and changes in their ultrastructure suggest cardiomyocyte immaturity of the interventricular septum, which is typical of patients with hypertrophic cardiomyopathy and may cause a disruption of the electromechanical coupling of the myocardium.