Long-term effects of chromium on morphological and immunological parameters of Wistar rats.

Hexavalent chromium raises high concern because of its wide industrial applications and reported toxicity. Long-term (135 days) oral exposure of Wistar rats to chromium in the form of K2Cr2O7 (exposed group~20 mg/kg/day) led to a decrease in thymus mass and thymocytes' number and caused structural and functional changes in the lymph nodes and spleen, namely lymphoreticular hyperplasia and plasmocytic macrophage transformation. Programmed cell death was increased in both thymocytes and splenocytes and decreased in lymphocytes in the T-zones of spleen and lymph nodes. Moreover, Cr (VI) administration decreased myeloid cells' and neutrophils' number, while it increased lymphoid and erythroid cells' number in bone marrow. Cr (VI) immune system effects seem to be related to oxidative stress induction, as depicted by the increased levels of diene conjugates and malondialdehyde in the spleen and liver and by the decreased activity of catalase and superoxide dismutase in rats' erythrocytes. In addition, exposure to Cr (VI) decreased copper, nickel and iron concentrations in blood and liver, while Cr levels in blood, spleen and liver were increased, as expected. The observed changes in the series of immunological parameters studied contribute to the development of new approaches for the prevention of low level Cr exposure toxicity.

[The role of telocytes in myocardial remodeling and the development of cardiovascular complications in patients with chronic heart failure after coronary artery bypass grafting].

Аim of the study. A study of the role of cardiac telocytes (Tc) in myocardial remodeling and the effect of changes in their morphology on the clinical outcome of coronary bypass (CABG) in patients with chronic heart failure (CHF). MATERIALS AND METHODS: The perioperative period was analyzed in 83 patients (43 men and 40 women) with CHF I, IIA and IIB, NYHA functional class I-III undergoing CABG. Myocardial biopsy of the right atrial appendage (RAA), obtained during the CABG, was studied using histological, immunohistochemical (expression of CD-34/vimentin, MMP-2, TIMP-1, caspase-3, bcl-2) and morphometric methods. RESULTS: In the analysis of the myocardium of RAA of a group of patients with cardiovascular complications (CVC) after CABG, a significant decrease in the diameter of cardiomyocytes (CMCs) of their nuclei, bulk density (BD) of CMC, a significant decrease in BD Tc, trophic index; an increase in CMC with signs of apoptosis, BD of stroma, a violation of the ratio of MMP-2/TIMP-1. CONCLUSIONS: The intercellular network Tc with secreted regulatory factors and microvesicles is an important structural and functional link of the myocardium. The decrease in BD Tc has a significant effect on the remodeling and regenerative potential of the myocardium, leading to the development of CVC in patients with CHF.

[Prognostic Value of Melatonin Level, Structural and Functional Changes of the Myocardium in the Development of Complications in Patients With Heart Failure who Underwent Coronary Artery Bypass Grafting: the Possibilities of Pharmacological Cardioprotection].

OBJECTIVE: To assess the significance of melatonin, NT-proBNP and morphological markers of myocardial remodeling for predicting the risk of complications after coronary artery bypass grafting (CABG) in patients with ischemic heart disease and chronic heart failure (CHF). MATERIALS AND METHODS: We included in this study 83 patients who underwent CABG in the period from September 2013 to October 2014. All patients before CABG underwent standard laboratory and instrumental examination. Concentrations of melatonin and NT-proBNP were measured in 2 days before and after surgery. The evaluation of morphological markers of myocardial remodeling (expression of MT2 melatonin receptors [MTR2], caspase-3, bcl-2) was carried out in tissue samples taken at biopsies of the right atrial appendage during CABG. RESULTS: Analysis of groups of patients with favorable and unfavorable hospital outcomes revealed no significant differences in serum levels of NT-proBNP. There was a significant decrease in the level of melatonin in the subgroup of patients with unfavorable outcome of CABG in combination with high comorbid load and high degree of apoptosis of cardiomyocytes at the background of moderate and high MTR2 expression. Comparative assessment of pharmacotherapy prior to CABG revealed favorable effect on myocardial remodeling of a combination of perindopril and amlodipine. CONCLUSION: Preoperative evaluation of the level of melatonin sulfate, apoptosis markers, and comorbid load can serve as prognostic factors of complicated course of the postoperative period after CABG in patients with CHF. The combination of perindopril and amlodipine in patients with heart failure with preserved ejection fraction exerted a significant cardioprotective effect on the myocardium, contributing to a decrease of the apoptotic dominant.

[Role of telocytes in the heart in health and diseases]. / Rol' telotsitov v serdtse v norme i pri patologii.

This review summarizes the data available in the literature on the development, structure, and function of telocytes (TCs) and their role in the heart in health and diseases. At the present time, TCs have been found in many organs of mammals and humans. TC is a small oval cell that contains a nucleus surrounded by small amounts of cytoplasm, with extremely long and thin processes named telopodias. TCs have unique ultrastructural and immunohistochemical features; double positive labeling for CD34/PDGFR-ß and CD34/vimentin is suitable for their identification. The role of TCs in the heart at different study stages is the subject of debate. There are currently available data on a decline in the number of cardiac TCs in patients with various heart diseases. Relying on a number of investigations showing that TCs are present in the subepicardial stem cell niches, the authors consider a hypothesis for the key role of cardiac TCs in the regeneration and reparation of the heart.

Role of Biological Characteristics of Staphylococcus epidermidis in Intraerythrocytic Invasion and in Modulation of Erythrocyte Catalase and Superoxide Dismutase Activities in Experimental Generalized Infection.

Studies on mouse model of generalized Staphylococcus epidermidis infection have demonstrated that erythrocytes more often contained microorganisms with pronounced antihemoglobin activity and less frequently with hemolytic activity. Infection with S. epidermidis strains characterized by pronounced hemolytic or antihemoglobin activities was associated with inhibition of erythrocyte catalase and superoxide dismutase activities in all cases, except infection with strains with high antihemoglobin activity, when superoxide dismutase activity increased.

[Nanostructured bioplastic material for traumatic corneal injuries].

OBJECTIVE: To substantiate the use of nanostructured bioplastic material for the treatment of traumatic eye injuries. MATERIAL AND METHODS: The study enrolled 96 eyes of 48 rabbits and was carried out in 3 series of experiments, different in the type of induced corneal trauma: mechanical erosion, alkaline or acid burn. The animals were clinically monitored and sacrificed for morphological investigation at days 3, 7, 14, 30, and 90. RESULTS: The size of mechanical corneal erosions was repeatedly evaluated with fluorescein eye stain test. In the experimental group, Hyamatrix biomaterial was topically administered according to an original technique. In the controls, soft contact lenses were inserted and sutured. Complete closure of the epithelial defect with no impact on corneal properties was achieved in 3 days in the experimental group and in4 days in the control group. As for alkaline and acid corneal burns, experimental and control groups received Hyamatrix biomaterial and Solcoseryl eye gel correspondingly. In the experimental group of alkaline burn the defect closed by day 7, in the controls--by day 10-11. Acid-induced corneal edema also resolved by day 7 in the experimental group and by day 14 in the control group. CONCLUSION: 1. The results of this experimental and morphological study prove the hyaluronic acid-derived nanostructured bioplastic material effective in accelerating corneal re-epithelialization after mechanical erosions as compared with the controls. 2. Topical application of the hyaluronic acid-derived nanostructured bioplastic material shortens the exudative phase of inflammation, promotes corneal defect closure with formation of a more subtle opacification, and stimulates corneal restoration after chemical burns.

[INTERACTION OF PRO- AND EUKARYOTES AND THE PROBLEMS OF TISSUE BIOLOGY].

The article considers the interaction of pro- and eukaryotes from the standpoint of tissue biology. Examples of long-term persistence of prokaryotes in eukaryotic cells are presented. Morpho-functional characteristics of the interactions of pro- and eukaryotic cells are given, including their ultrastructural relationship. It is shown that the symbiosis between unrelated organisms is a reflection of their adaptation to the use of trophic resources of the environment. One of the implications of endocytobiosis of non-pathogenic bacteria in eukaryotic cells is to increase the biodiversity. The concept of multicellular eukaryotic organisms as complex cell and tissue systems of symbiotic interactions of pro- and eukaryotic cells, is discussed.

[The concept of tissues: the history and the present].

The concept of tissues is one of the main categories in histology. This paper describes the evolution of the tissue concept during the last century. The review of different definitions of tissues found in Russian and foreign educational and scientific literature published in XX-XXI centuries, is presented. Special attention is given to the changes of the concept of tissues that due to the appearance of the new approaches and concepts in tissue biology (doctrine of stem cells, differon principle of tissue organization, histione conception). A brief characteristic of different definitions of tissues based on various approaches that were suggested by Russian and foreign histologists, is given. The data are discussed that support the idea that the "tissue" concept belongs to a number of undefinable basic concepts of tissue biology.

[Extracellular matrix remodeling myocardium of the left ventricle rats with experimental heart failure after perindopril and melatonin administration].

The aim of the study was to examine the reorganization of extracellular matrix left ventricular myocardium (LVM) rats (n = 38) with experimental heart failure (EHF) as affected by perindopril and melatonin administration. Rats LVM was studied using the methods of light microscopy, immunocytochemistry and morphometry. At day 14 of EHF, marked mosaic staining cardiomyocytes acid dyes, manifest hemodynamic disturbances: venous and capillary congestion, lymphostasis, perivascular and interstitial edema, there was a increase the volume density (OD) stroma, high activity of MMP-1 and TIMP-1. After modeling the EHF to 28 days in LVM, a further increase of hemodynamic met, cardiosclerosis areas and perivascular sclerosis, a significant increase OD stroma, observed decrease in the expression of MMP-1 and TIMP-1. In rats given perindopril and melatonin for 14 days, there was a regression of pathological changes in the balance was maintained MMP-1/TIMP-1 ratio close to the group of intact rats. Cardioprotective effects of perindopril and melatonin on extracellular matrix LVM of rats with EHF is discussed.

[Interstitial endocrine apparatus of testes of experimental animals in conditions of chromium-benzene intoxication].

With the use of histological, morphometric and statistical methods there was shown a gonadotropic effect of chromium, benzene and also their mixtures in male mice (CBA x C57Bl6) F1. The established structural changes in the testes of exposed animals showed the suppression of their germinative and endocrine functions. The response of Leydig cells in the chromium group expresses a development of the compensatory process in the relation with the destruction of seminiferous epithelium.

[Morphological basis of the effect of hypothalamic neurosecretion on structural and functional homeostasis of pro- and eukaryotes].

Experimental histological aspects of neuroendocrinology are examined together with the emphasis on the regulatory and adaptogenic role of hypothalamic nonapeptidergic neurosecretory system in provision of structural-functional homeostasis in animal organism, including the conditions of its interaction with the microorganisms. Some new facts are presented demonstrating the positive effect of oxytocin on the realization of histo- and organotypical potencies by the tissues with different cambial characteristics during the necrotic suppurative processes. The priority directions are indicated for the further development of the fundamental and applied aspects of neuroendocrinology for optimization of the reparative histogeneses and inactivation of bacterial persistence potential.

[Structural reorganization of the myocardium in ovariectomized rats with experimental heart failure after melatonin administration].

The aim of the study was to examine the reorganization of left ventricular myocardium (LVM) in ovariectomized rats with experimental heart failure (EHF) as affected by melatonin administration. Rat LVM was studied using the methods of light microscopy, immunocytochemistry and morphometry. At day 14 of EHF, marked heteromorphism of contractile cardiomyocytes (CMC), signs of dystrophy, overcontraction and damage of muscle fibers, karyopyknosis, paranuclear edema, local sarcoplasm destruction were detected together with CMC showing signs of apoptosis. At day 28 after EHF modeling, a further increase in the number of CMC with significant changes in the morphological and tinctorial properties was found as well as the cells with signs of apoptosis. In rats given melatonin for 14 days, there was a regression of pathological changes, with the decrease in the hypertrophy of CMC and their nuclei, reduction of the number of CMC with the signs of apoptosis. Cardioprotective effect of melatonin on LVM of ovariectomized rats with EHF is discussed.

[Morphological features of the organs of the immune system in conditions of exposure to chromium and benzene].

Morphological features of the thymus, spleen and lymph nodes on the 45th--and 90th day of oral exposure to benzene, potassium dichromate and their mixtures were studied in 40 Wistar rats. A strong trend to a decrease in the activity of T lymphocytes has been established. Apoptotic thymocytes and lymphocytes in the T-dependent areas of spleen and lymph nodes have been revealed.

[Morphological characteristic of gastric submucosal vessels in the peritumoral areas].

The structural peculiarities of the gastric submucosal vessels in the areas adjacent to the tumor, were studied in 63 patients with gastric cancer. It was found that the processes of tumoral angiogenesis affected not only a tumoral tissue, but also the submucosal regions adjacent to the tumor was characterized by an abnormal structure of its vascular network, their excessive twisting and pathological dilatation. In samples obtained from 33 out of 63 patients studied, the microcirculatory bed vessels were found to be formed by a single layer of endothelial cells. These vessels were found in 25 out of 28 patients with metastases in regional lymph nodes (89,3%) and only in 8 out of 35 patients without metastases (22,8%). The data obtained can be used for predicting the risk of lymphogenic metastase spread in patients with gastric cancer.

Bacterial translocation from the gastrointestinal tract in healthy and injured rats.

OBJECTIVE: To study the phenomenon of asymptomatic penetration of bacteria from the gastrointestinal tract into various tissues of healthy rats and rats with skin wounds and closed fractures at different doses and with different species of bacteria. METHOD: Healthy rats and rats with full-thickness skin wounds and closed femoral fractures were given varying doses of radiolabeled bacteria (S. aureus 209P or B. subtilis 534) per os in doses of up to 1010 bacteria per 1kg of body mass. Six hours later, these animals were euthanised and, together with blood smears, tissue samples of liver, spleen, stomach, small and large intestine, lung, hypothalamus, posterior pituitary gland, epinephros and skin and muscle from the wound site were subjected to bacteriological and histological analysis. RESULTS: In total, 99 rats were used for the experiments. Viable bacteria were found to systemically penetrate into the tissues of the internal organs in 45 healthy animals, 27 rats with incisions and 27 rats with fractures. In healthy animals, viable bacteria mostly accumulated in the stomach wall, the mucous membranes of the small intestine, the mesenteric lymph nodes and in the spleen and liver. Translocation was registered in uninjured animals receiving 1x106 and more bacteria per 1kg of rat's weight and in injured rats receiving 1x104 bacteria and more. Bacteria penetrated the local tissues at both wound sites (skin wounds and fracture sites). CONCLUSION: Bacterial translocation is a protective mechanism that gives the immune system constant contact with external antigens, although it can contribute to the spreading of infection in an organism. In healthy animals, small amounts of bacteria penetrate systemically from the tract and small intestine into the tissues of the spleen and liver. During injury, translocated bacteria also appear at the focus of injury. CONFLICT OF INTEREST: None.