Structural Changes in Rat Hepatocyte Nucleolus under Nucleolar Stress Caused by Hypothermia.

Structural changes in rat hepatocyte nucleoli were studied during deep hypothermia simulated by immersion in water at 5°C for 40 min (ambient air temperature 7°C). In comparison with the control, phenomena of nucleolar stress occurred in rats during hypothermia: the number of fibrillar centers (FC) per nucleus (by 1.7 times) and per nucleolus (by 1.

Ultrastructural Myocardial Reorganization during Experimental Treatment with Doxorubicin and Atorvastatin.

We studied ultrastructural reorganization of the myocardium in Wistar rats treated with doxorubicin (single intraperitoneal injection in a dose of 15 mg/kg) and atorvastatin (daily intragastric administration in a dose of 20 mg/kg for 7 days) individually and in combination. It was found that doxorubicin administered alone or in combination with atorvastatin induces disturbances of varying severity in cardiomyocyte ultrastructure indicating the development of regenerative and plastic myocardial insufficiency. In case of isolated administration of atorvastatin, lytic changes in myofibrils, increased autophagic processes, and segregation of the fibrillar and granular components in the nucleoli appeared in the ultrastructure of some cardiomyocytes with increasing the observation period.

Monooxygenase System and NO Metabolism in Liver Microsomes of Rats with Toxic Hepatitis and the Effect of Sesquiterpene Lactones.

We analyzed changes in activities of enzymes of phases I and II of xenobiotic biotransformation and parameters of NO metabolism in liver microsomes of rats with toxic CCl-induced hepatitis after a 14-day course of sesquiterpene lactones from Artemisia leucodes (10 mg/kg). It was found that toxic hepatitis was associated with significant inhibition of NADPH-cytochrome c-reductase, benzo(a)pyrene hydroxylase, and NADPH-diaphorase, reduced cytochrome P-450 content, and enhanced induction of nitrate/nitrite reductase with accumulation of NO metabolites in the liver. Administration of sesquiterpene lactones stimulated activity of the studied components of the cytochrome P-450 system and promoted recovery of the NOergic system components; the effects were most pronounced in 7 and 14 days after treatment.

Morphology of the Myocardium after Experimental Bone Tissue Trauma and the Use of Extracellular Vesicles Derived from Mesenchymal Multipotent Stromal Cells.

The effect of extracellular vesicles (EVs) of various origins on the heart structures in the time of health and disease has been well studied. At the same time, data on the distribution of EVs throughout the body after introduction into the tissues and the possibility of the influence of these EVs on organs distant from the injection site are practically absent. It is also necessary to note a certain inconsistency in the results of various researchers: from articles on the direct absorption of EVs derived from mesenchymal multipotent stromal cells (MSC EVs) by cardiomyocytes to the data that the heart is inherently immune to drug delivery mediated by nanoparticles.

Multipotent Stromal Cell Extracellular Vesicle Distribution in Distant Organs after Introduction into a Bone Tissue Defect of a Limb.

When administered intravenously, extracellular vesicles derived from multipotent stromal cells (MSC EVs) immediately pass through the lungs along with the blood and regularly spread to all organs. When administered intraperitoneally, they are absorbed either into the blood or into the lymph and are quickly disseminated throughout the body. The possibility of generalized spread of MSC EVs to distant organs in case of local intratissular administration remains unexplored.

Some Special Aspects of Liver Repair after Resection and Administration of Multipotent Stromal Cells in Experiment.

Changes in rat liver after resection and injection of autologous multipotent mesenchymal stromal cells of bone marrow origin (MSCs) transfected with the GFP gene and cell membranes stained with red-fluorescent lipophilic membrane dye were studied by light microscopy. It was found that after the introduction of MSCs into the damaged liver, their differentiation into any cells was not found. However, under the conditions of MSCs use, the number of neutrophils in the parenchyma normalizes earlier, and necrosis and hemorrhages disappear more quickly.

Features of Myocardial Remodeling and Changes in the Blood Lipid Spectrum in Experimental Doxorubicin-Induced Cardiomyopathy and Atorvastatin Administration.

Structural myocardial reorganization and changes in the blood lipid spectrum in rats were studied after administration of a single sublethal dose of doxorubicin (15 mg/kg) alone and in combination with atorvastatin (20 mg/kg/day over 7 days). It was established that doxorubicin induced the development of dyslipidemia in experimental animals (the concentrations of total cholesterol, triglycerides, and VLDL increased by 2.2, 2.

[Molecular mechanisms of the cardiotoxic action of anthracycline antibiotics and statin-induced cytoprotective reactions of cardiomyocytes].

The manifestation of the side cardiotoxic effect of anthracycline antibiotics limits their use in the treatment of malignant processes in some patients. The review analyzes the main causes of the susceptibility of cardiomyocytes to the damaging effect of anthracyclines, primarily associated with an increase in the processes of free radical oxidation. Currently, research is widely carried out to find ways to reduce anthracycline cardiotoxicity, in particular, the use of cardioprotective agents in the complex treatment of tumors.

Immunistochemical Analysis of the Expression of TGFβ, Galectin-1, Vimentin, and Thrombospondin in Gastric Cancer Associated with Systemic Undifferentiated Connective Tissue Dysplasia.

We performed immunohistochemical analysis of the expression of TGFβ, galectin-1, vimentin, and thrombospondin in the mucosa in gastric cancer of diffuse and intestinal type associated with systemic undifferentiated connective tissue dysplasia. In diffuse gastric cancer, both with and without association with connective tissue dysplasia, a higher level of expression of TGFβ, galectin-1, vimentin, and thrombospondin in the tumor was detected in comparison with the perifocal and tumor zones in intestinal gastric cancer, which may reflect the pathogenetic peculiarities of the two histotypes of gastric cancer. Intestinal type of gastric cancer associated with connective tissue dysplasia is characterized by a high level of expression of galectin-1 and vimentin in the perifocal zone and TGFβ in the tumor zone.

Structural Analysis of the Myocardium in Experimental Anthracycline-Induced Cardiomyopathy Combined with Adrenergic Stimulation.

We studied dynamic changes in the total number of cardiomyocytes and the character of structural lesions in the myocardium in rats with modeled anthracycline-induced cardiomyopathy provoked by a single injection of doxorubicin in a dose of 10 mg/kg alone or in combination with subsequent adrenergic stimulation. The injections of epinephrine during the development of anthracycline-induced cardiomyopathy resulted in more pronounced loss of body weight, stronger decrement of the heart weight, and more severe decrease of the cardiomyocyte count in comparison with the corresponding changes induced by doxorubicin alone. The basic lesions of cardiomyocytes in anthracycline-induced cardiomyopathy are the lytic alterations and subsegmental contractures; in contrast, combined use of doxorubicin and epinephrine provoked degree II and III contractures.

Intracellular Reorganization of Cardiomyocytes in Dyslipidemic Cardiomyopathies.

The study examined the myocardial ultrastructural alterations in rats maintained on various atherogenic diets. It revealed the complex ultrastructural alterations of cardiomyocytes and endotheliocytes (including the lytic and destructive changes of the intracellular organelles, upregulation of the autophagocytosis in the cardiomyocytes, and necrobiosis with apoptosis of endotheliocytes) reflecting the cytopathic features of circulating cholesterol and lipoproteins, whose elevation determined the intensity of destructive processes. The revealed peculiarities in the changes of lipid inclusions (their osmiophilic transformation) in cardiomyocytes can be provoked by entry of cholesterol into the cells and its further metabolic modifications.

Role of Matrix Metalloproteinase-2 in the Development of Cyclophosphamide-Induced Cardiomyopathy.

Immunohistochemical assay was employed to determine localization of MMP-2 in cardiomyocytes of WAG rats and changes in MMP-2 expression during modeled cardiomyopathy induced by single intraperitoneal injection of cyclophosphamide (125 mg/kg) alone or in combination with preventive intraperitoneal administration of an equal dose of asparcam-L (potassium-magnesium asparaginate) 30 min prior to the cytostatic. In the myocardium of control and experimental rats, MMP-2 was mostly located in cardiomyocyte nuclei. During the development of cyclophosphamide-induced cardiomyopathy (in 3 days after injection), the index of MMP-2-positive cardiomyocyte nuclei increased by 76%.

Expression of Flk-1 and Cyclin D2 mRNA in the Myocardium of Rats with Doxorubicin-Induced Cardiomyopathy and after Treatment with Betulonic Acid Amide.

The expression of VEGFR2 (Flk-1, according to immunohistochemistry) and of cyclin D2 mRNA (according to real-time PCR) in the myocardium of rats is studied in doxorubicin-induced cardiomyopathy and in response to betulonic acid amide. Doxorubicin alone and in combination with betulonic acid amide causes after 3 days a manifest reduction of cyclin D2 mRNA expression (by 38 and 63%, respectively), while injection of betulonic acid amide alone causes a 23-fold increase of cyclin D2 mRNA expression. An increase of cyclin D2 mRNA expression has been detected in all experimental groups after 14 days of experiment, the most pronounced in response to betulonic acid amide (63 times).

Immunohistochemical Study of the Expression of Vascular Endothelial Growth Factor Receptor-2 (KDR/Flk-1) during Myocardial Infarction.

Immunohistochemical study showed that vascular endothelial growth factor receptor-2 (KDR/Flk-1) is expressed in the cytoplasm of viable cardiomyocytes, mononuclear cells of the granulation tissue, and smooth muscle cells of intramural arteries at all terms of postinfarction reparative regeneration. Cardiomyocytes were highly heterogeneous by the intensity of staining. This feature was typical of cardiomyocytes in the ischemic area (no staining), as well as within various muscle bundles and one muscle bundle.

High Antimetastatic Activity of Platin Liposomal Form after Lyophilization and Storage.

Antimetastatic activity of Platin in lyophilized liposomes stored for 7 years after fabrication was evaluated. The main flaw of liposomes as vehicles for drug delivery to the tumors is their high affinity for the liver, which accumulates a great amount thereof. This property of liposomes can be used for adjuvant therapy of operable primary tumors metastasizing to the liver.

Cardiotoxic and Dyslipidemic Effects of Doxorubicin and Betulinic Acid Amide.

Changes in the blood lipid spectrum and structural reorganization of the rat myocardium in response to injection of a single sublethal dose of doxorubicin (7 mg/kg) alone and in combination with course administration of betulonic acid amide (100 mg/kg/day for 14 days) were studied. Betulinic acid amide in the specified dose exhibited less pronounced cardiotoxic (necrobiotic impairment of cardiomyocytes) and dyslipidemic (increase of cholesterol and triglyceride levels) effects in comparison with doxorubicin. Combined treatment with betulinic acid amide and doxorubicin led to more pronounced remodeling of the myocardium, which was shown by a significant increase of the connective tissue/cardiomyocyte volume ratio detected by day 14 of the experiment.

Clinical Morphological Studies of Myelofibrosis with Different Types of Bone Marrow Involvement in Patients with Chronic Lymphocytic Leukemia.

Clinical-morphological study of myelofibrosis was carried out in patients with chronic lymphocytic leukemia at the debut of the disease. Trephinobiopsy specimens of the ileac bone, aspirated specimens of the bone marrow, and peripheral blood smears were studied in 80 patients. Chronic lymphocytic leukemia was associated with myelofibrosis of different severity in 22.

Stimulation of Cardiomyocyte Regeneratory Reactions under Conditions of Cytopathic Hypercholesterolemia.

The regeneratory reactions of cardiomyocytes in the heart under conditions of cytopathic exposure to hypercholesterolemia and during verapamil treatment were studied by immunohistochemical detection of proliferation marker Ki-67 and evaluation of cardiomyocyte count. A 30-day exposure of rats to atherogenic diet led to an increase of Ki-67+ cardiomyocytes by 14.5-16.

Immunohistochemical Analysis of MMP-2 Expression in the Myocardium During the Postinfarction Period.

Immunohistochemical analysis revealed 2.5-fold increased of expression MMP-2 in myocardium samples during the early period (up to 3 days) of postinfarction reparative regeneration. During this period, MMP-2 was detected mainly in monocytes/macrophages circulating in the blood and migrating to the necrotic zone, while expression in the intermuscular and perivascular connective tissue was lower.

Expression of ryanodine receptor mRNA and sarcoplasmic Ca²⁺-ATPase mRNA in the myocardium and intracellular reorganization of cardiomyocytes in dyslipidemia and during verapamil treatment.

In experiments on rats, atherogenic diet led to hypercholesterolemia, while addition of verapamil to the diet led to the development of hypertriglyceridemia in these animals. Dyslipidemia induced significant changes in the cardiomyocyte ultrastructure (lytic changes in myofibrils and sarcoplasmic matrix and aggravation of autophagocytosis) that were most pronounced after addition of mercazolyl alone to the diet. After 30-day atherogenic diet, we observed a decrease in the relative content of RyR2 mRNA (by 67-73%, p<0.

Remodeling of myocardium in rat with chronic dyslipidemia and under conditions of verapamil treatment.

The type and intensity of remodeling (structural reorganization) of the myocardium in Wistar rats were studied under conditions of experimental chronic dyslipidemia and verapamil treatment. Long (64 days) atherogenic diet caused dyslipidemia and led to reduction of the heart percent weight. The cytopathic effect of dyslipidemia manifested in more intense lytic injuries of cardiomyocytes, development of diffuse and small focal cardiosclerosis under conditions of manifest circulatory disorders.

Proliferative activity of cadriomyocytes in chronic hypercholesterolemia.

We studied proliferative activity of cardiomyocytes (using proliferation marker Ki-67) and compared it with their total number in the heart under conditions of experimental chronic hypercholesterolemia and its combination with hypothyroidism. It was found that Ki-67-positive cells are primarily located in the subepicardial layer near the heart base in both intact and experimental animals. Replicative cardiomyocyte pool in intact rats constituted 1.

Expression of mRNA of apolipoprotein E, apolipoprotein A-IV, and matricellular proteins in the myocardium and intensity of fibroplastic processes during experimental hypercholesterolemia.

The expression of mRNA of matricellular proteins (osteopontin, and lumican), apolipoproteins E and A-IV, and microsomal triglyceride transfer protein, and the intensity of fibroplastic processes were studied in the myocardium of rats during experimental chronic hypercholesterolemia. We have found that the development of chronic hypercholesterolemia was followed by an increase in volume density of interstitial connective tissue in the myocardium reflecting the activation of fibroplastic processes. A slight positive correlation was observed between the connective tissue density in the myocardium and expression of osteopontin mRNA (r=0.

Structural changes in the myocardium and serum lipid spectrum in experimental hypercholesterolemia and hypothyroidism.

We studied the peculiarities of lipid spectrum of the blood and structural reorganization of the myocardium in experimental hypercholesterolemia with and without hypothyroidism. It was found that alimentary hypercholesterolemia accompanied by elevated total cholesterol, LDL, HDL, and triglyceride concentrations led to a decrease in body weight, heart weight, number of cardiomyocytes in the heart and induced pronounced lytic changes in cardiomyocytes, circulation disorders (sludge syndrome, echinocytosis of erythrocytes, lymphostasis), diffuse fibrosis of the stroma, and appearance of foam cells among diffuse mononuclear infiltrate cells. The combination of hypercholesterolemia with hypothyroid status caused more pronounced changes in the lipid spectrum and atherogenic index and more pronounced lytic and necrobiotic changes in cardiomyocytes.

Ultrastructure and stereology of cardiomyocytes in the development of regenerative and plastic myocardial insufficiency during ontogeny.

The age-related features of ultrastructural reorganization of cardiomyocytes were studied in rats with anthracycline-induced injury. The development of regenerative and plastic insufficiency of cardiomyocytes in animals of various age groups was accompanied by stereotypic ultrastructural reorganization. The major changes concerned the nucleus, myofibrillar compartment, and rough sarcoplasmic reticulum.