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The subcutaneous tissue of rats after implantation of polypropylene materials with adsorbed bone marrow-derived mesenchymal multipotent stromal cells (MMSCs) was studied using light microscopy. Inflammation in response to implantation was mild, and the foreign material was encapsulated into a thin strip of dense fibrous connective tissue with multinucleated macrophages. By 1 year after introduction of the monofilament and 6 and 12 months after implantation of the mesh product, some threads were deformed, broken, and had sharp edges. Small fragments of foreign material appeared in the adjacent tissues surrounded by their own relatively thick acellular capsule. As a result of preliminary adsorption of MMSCs on polypropylene, the thickness of the connective tissue capsule decreased, its vascularization increased, and the severity of inflammatory infiltration decreased. However, all effects of MMSCs adsorption in rats were transient and disappeared within 1 week., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

In a patient after implantation of a metal screw implant into the bone with suturing of the soft tissues above it after 6 months there was a spontaneous delimitation of the product by a thin strip of compact bone tissue, most likely formed from the bone structures damaged during the operation. Small bone fragments formed during the preparation of the implantation bed were found in the tissues as homogeneous eosinophilic deposits without inflammation and macrophage reactions.

A literature search was conducted to review papers on the results of studies of clear cell renal cancer (CCRC) vascularization. Numerous data on the relationship between tumor pathogenesis and its vascularization have been revealed, which indicates the multifactorial nature of CCRC development and the significant role of angiogenesis in this process. It should be taken into account that patients with CCRC may have impaired vessel formation even before tumor development. To evaluate normal and pathologic angiogenesis, a pathohistologic study using immunohistochemistry is certainly necessary. Due to the significant role of angiogenesis in the development and course of CCRC, the use of drugs that suppress the formation of the vascular network in the tumor is relevant and advisable. To date, many drugs have been developed and introduced into clinical practice to inhibit angiogenesis. However, such drugs have not lived up to the expectations placed due to the frequent and rapidly developing drug resistance. Timely detection of pre-tumor and tumor processes, as well as effective treatment of cancer, including CCRC, is possible only with close cooperation between pathomorphologists and oncologists.

The state of rat kidneys after injection of bone marrow multipotent stromal cells (MSC) labeled with Vybrant CM-Dil into intact or resected liver was studied by fluorescence microscopy. The main structural changes in the kidneys after MSC injection into intact and partially resected liver manifested as granular dystrophy and necrobiotic/necrotic changes in single epithelial cells of the distal tubules and collecting ducts, thrombosis of some vessels, progression of an ascending urinary tract infection (detection of dust-like fluorescent objects), which can be due to the immunomodulating or even immunosuppressive influence of MSC and their detritus. MSC injected into the intact or resected liver, as well as the products of their degradation were not detected in the kidneys at all terms of observation. After injection of MSC into partially resected liver, manifestations of bacterial contamination of the renal medulla appeared later. The injection of MSC into the liver can be complicated by thrombosis of the renal vessels, which should be taken into account when using this administration route in the cell therapy., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature.)

The possibility of dissemination of bone marrow multipotent stromal cells stained with Vybrant CM-Dil after injection into an intact and resected liver was studied using luminescence microscopy. Labeled cells were found in the kidneys, spleen, lungs, axillary, mesenteric, and inguinal lymph nodes. We observed dissemination of multipotent stromal cells and their detritus throughout the body that occurred only after filtration in the lungs, where most cells underwent destruction. Perivascularly located macrophages in various organs can phagocytize multipotent stromal cells and their detritus from blood vessels. The content of objects labeled with Vybrant CM-Dil in distant organs was significantly lower after multipotent stromal cell injection into the resected liver, which was associated with the deposition of cells in the damaged area of the organ and their partial entry into the abdominal cavity., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

Based on the literary analysis, the influence of cellular technologies on the results of implantation of mesh materials was studied. The scientific literature of recent years contains a large amount of data devoted to the study of mesh structures and the possibilities of their modification using multipotent stromal cells (MSC) for implantation into patients for correcting tissue defects and pelvic organ prolapse. However, the ideal implant has not yet been created. Additional studies with a longer follow-up period are needed to determine the most successful and safe methods and materials for the restoration of pathologically altered or lost tissues and the transition to clinical trials. It is also yet to come to an unambiguous understanding of the best sources of MSC, ways for stimulation of proliferation, preservation and delivery of these cells into the necessary tissues of the body, to thoroughly study the causes of inefficiency and the risks of developing various complications, especially in the long term. The progress of urological implantology in modern conditions, of course, will be associated with the introduction of modern materials and technologies, including the using MSC.

Light luminescent microscopy was used to study the distribution of extracellular microvesicles with PKH26-stained membranes secreted by placenta-derived mesenchymal stromal cells in the uterine tissues at different terms after injections to intact rats and after abdominal delivery (a model of cesarian section). Microvesicles migrated through the uterine tissues and were detected for at least 8 days after injection. In some cases, microvesicles were more numerous in the uterus after cesarian section modeling, which can be related to blockade of microcirculation and lymph flow due to inflammation accompanying surgical intervention. The content of microvesicles in the uterine tissues gradually declined due to macrophage phagocytosis and, probably, due to their migration into the vascular bed. Despite their size, properly stained extracellular microvesicles can be detected by light microscopy in tissues after injections.

The minimum and maximum indicators of the length, width, area or volume of organs and structures in the lower urinary tract can normally vary up to 2-3 times. With age, at healthy women the absolute and relative length of the urethra, the urethrovesical angle, and the inclination of the urethra do not change. Both smooth and striated muscle tissues, which are part of various departments of the female urethra, undergo atrophy during the aging process. Smooth muscle tissue is less variable with age, but striated muscle symplasts are sometimes completely absent in urethral biopsies from elderly patients. With age, the vascularization and density of the innervation decrease in the urethral structures, but the content of connective tissue in the external urethral sphincter increases. Urinary tract mobility at young women is more pronounced than at older women. The apparent insufficiency of modern investigations about age-related changes in the lower urinary tract indicates the relevance and need to continue studying of the organ and tissue transformation in the urinary system during aging, this may be important for determining the etiology and pathogenesis of some pathological conditions, such as stress urinary incontinence, as well as for differential diagnosis between age norm and pathology.

The researches devoted to postoperative liver regeneration and influence in this process were analyzed. Liver injury is followed by hypertrophy of residual liver parenchyma. The use of various cytokines is perspective for activation, acceleration and inhibition of liver recovery. Cellular technologies in the treatment of liver diseases can affect its repair. Moreover, these methods could make unnecessary resection and transplantation of liver in certain cases. It is generally accepted that the main effect of multipotent stromal cells (MSC) in liver failure is associated with their differentiation to the cellular elements of this organ. At the same time, recent reports revealed that MSC injection to the liver is followed by their quick death, dissemination to other organs and tissues or even elimination from the organism. Regeneration of non-parenchymal structures (vascular network and bile ducts) should be considered in addition to functional recovery of liver parenchyma after resection. Clarification of indications and contraindications for MSC therapy, as well as prevention of possible complications associated with cellular technologies are required.

Aim: To integrate transcriptomic and DNA-methylomic measurements on varicose versus normal veins using a systems biological analysis to shed light on the interplay between genetic and epigenetic factors., Materials & Methods: Differential expression and methylation were measured using microarrays, supported by real-time quantitative PCR and immunohistochemistry confirmation for relevant gene products. A systems biological 'upstream analysis' was further applied., Results: We identified several potential key players contributing to extracellular matrix remodeling in varicose veins. Specifically, our analysis suggests MFAP5 acting as a master regulator, upstream of integrins, of the cellular network affecting the varicose vein condition. Possible mechanism and pathogenic model were outlined., Conclusion: A coherent model proposed incorporates the relevant signaling networks and will hopefully aid further studies on varicose vein pathogenesis.

Hemorrhagic changes after subcutaneous injection of autologous bone marrow multipotent mesenchymal cells with transfected GFP gene and additionally stained cell membranes to WAG rats in the projection of ligated femoral vein were studied by fluorescent microscopy. Hemorrhages in tissues with experimental acute local venous occlusion were caused by a combination of venous hypertension with inflammation around the foreign body - the ligature used for ligation of the vein. Fibrin found in tissues together with erythrocytes in the hemorrhages could stimulate the formation of granulations and new vessels instead of damaged or thrombosed ones. Multipotent mesenchymal stromal cells and their detritus getting into the regional lymph nodes initiated immune reactions morphologically confirmed by stubborn hypertrophy and hyperplasia of the lymphoid nodules, hemorrhages, and manifest diapedesis of erythrocytes to the organ parenchyma and sinus system.

Changes in the muscular tissue after subcutaneous injection of autologous bone marrow multipotent mesenchymal stromal cells transfected with GFP gene and additionally stained with cell membrane dye Vybrant CM-Dil in the projection of ligated femoral vein were studied by light microscopy with luminescence. Stromal cells injected through the skin can appear not only in the damaged tissue where acceleration of regeneration processes is required, but also in intact structures located in superficial or deeper layers. In intact muscular tissue, stromal cells spreading in the perivascular tissue initiate inflammation and migration of macrophages, activate and even trigger sclerotic processes due to differentiation into connective tissue cells (fibroblasts) and stimulation of proliferation and collagen synthesis by host fibroblasts. Injected multipotent mesenchymal stromal cells are gradually phagocytized by macrophages.

Mannans, which are biological macromolecules of polysaccharide origin and function as immunomodulators, have been shown to stimulate macrophages in vivo by interaction with the mannose receptor. Thus, they can be used to stimulate macrophages in order to effectively remove circulating atherogenic lipoproteins. Our primary aim was to evaluate the hypolipidemic potential of mannans from C. albicans serotype A (mannan A) and serotype B (mannan B) in a murine model of hyperlipidemia. Mannan A and mannan B were shown to significantly (p<0.05) stimulate both the proliferation (p <0.05) and nitric oxide production of murine peritoneal macrophages in vitro. Pre-treatment of CBA/Lac mice with mannan A prior to induction of hyperlipidemia significantly (p<0.001) reduced serum atherogenic LDL-cholesterol, total cholesterol, and triglycerides. Mannan B exhibited a similar, but more potent, hypolipidemic effect. Electron microscopic analysis of liver revealed a significant (p<0.001) decrease in the volume of lipid droplets when hyperlipidemic mice were pretreated by both mannans. In conclusion, our findings would suggest that both polysaccharide-based biological macromolecules evaluated in the present study, specifically, the natural immunomodulators (mannans A and B), appeared to function as effective lipid-lowering macromolecules, which could potentially serve as adjunct therapy to more conventional hypolipidemic medications such as a statin drug., (Copyright © 2017 Elsevier B.V. All rights reserved.)

For assessment of the modern situation about the choice of materials for manufacture of dental implants and the processing of their surface the scientific literature for the last 2 years was study. On the basis of a large number of contradictory results of the researches devoted to each of dental implantation problems it is possible to draw a conclusion that any of primal problems of implantology is finally not solved. There is no unique opinion at the choice of optimum material for manufacture of dental implants, at the way of processing and modification of their surface. The problem of improvement of quality of dental implantation and fight against complications of this procedure cannot be solved simple drawing other substances on the implanted material surface, this task more easily and more successfully is solved via changes of product structure and various modification of implant surface. Up to the present the researches of an opportunity to influence on characteristics of the implanted materials, changing their structure and character of a surface, continue. And the publications reporting about the considerable positive effect of artificially created roughnesses on product surfaces, and the articles claiming that there are no big differences between the rough and polished implants are confirmed by objective measurements with statistical processing of the obtained data. It should be noted that among articles there are very many works of the doubtful plan or with insufficiently valid conclusions. This review leads to the conclusion that further clinical and experimental studies and about the choice of materials for manufacture of implants and at the ways of processing of their surface are necessary.

Autologous multipotent mesenchymal stromal cells (MMSC) of bone marrow origin with transfected GFP gene and additionally stained cell membranes were injected to rats through the skin in the projection of ligated femoral vein. The results were evaluated by fluorescent microscopy. No signs of MMSC incorporation into the wall of ligated vessel or reorganized collaterals were detected. Angiogenesis processes involving MMSC were detected in experimental rats within just 4 days and progressed until week 2 postinjection, mainly in granulations at the site of surgical intervention and the cicatrix forming there. Injected MMSC completely formed all tunics of the new vessels and incorporated in the vessels forming from the recipient cells. MMSC and the objects created from them were gradually eliminated with participation of macrophages and replaced by structures formed from the recipient cells.

The author name G. A. Chastikina should read G. A. Chastikin.

The peculiarities of tissue sclerosis after injection of autologous bone marrow multipotent mesenchymal stromal cells transfected with GFP gene and stained with Vybrant CM-Dil cell membrane dye were studied by light microscopy with luminescence. The surgical intervention consisting in ligation of the great vein was followed by tissue sclerotic transformation caused by direct damage and chronic inflammation caused by the presence of slowly resorbed ligature. Injection of stromal cells after this intervention led to formation of more extensive scar. This can attest to the possibility of stromal cells differentiation into connective tissue cells, fibroblasts, and stimulation of proliferation and collagen synthesis by host fibroblasts. A decrease in the volume of dense fibrous connective tissue due to scar reorganization at latter terms cannot not excluded.

Numerical density of vessels in axillary lymph node structures in breast cancer patients was studied by light microscopy with antibodies to CD34. The correlation between the stage of breast cancer and vascularization of lymph nodes was analyzed. The development of breast cancer was followed by rapid and significant increase in the number of blood vessel in axillary lymph nodes in general and in all their specific areas, especially in the paracortex and medullary substance. Strong or very strong positive correlation between the stage of tumor process and parameters of vascularization was observed in various areas of the axillary lymph nodes. No significant differences in node vascularization were observed between women without breast cancer and women with stage I breast cancer; the differences were found only starting from stage II. Considerable vascularization of lymph nodes can be a symptom of malignant tumor growth in the area of lymph collection. The duration of the tumor process and the size of the tumor can be indirectly evaluated by the increase in vessel number in lymph nodes.

The initial stages of angiogenesis in rats after transcutaneous injection of autologous bone marrow multipotent mesenchymal stromal cells transfected with GFP gene and stained cell membranes in the projection of ligated femoral vein were studied by fluorescent light and confocal laser microscopy. Large clusters of brightly fluorescing elongated fibroblast-like cells were seen in the paravasal tissue and in the postoperative scar and signs of angiogenesis were noted as soon as in 4 days. The injected cells not only formed new vessels, but also integrated into vessels formed by host cells. Some injected cells were phagocytizied by macrophages and the latter started to fluoresce due to the presence of the membrane dye. These macrophages within the specified period appeared in the regional inguinal lymph nodes where they formed clusters in the lymphoid parenchyma of the cortical substance.

The possibility of formation of lymphatic vessels after introduction of autologous bone marrow-derived multipotent mesenchymal stromal cells transfected with GFP gene into thrombosed femoral vein was studied by fluorescent microscopy. Vascular thrombosis caused by ligation of the great vein with subsequent injection of thrombin solution was accompanied by blockade of regional lymph flow. The cells injected into thrombosed vein directly participate in the formation of new lymphatic vessels in the paravasal tissue surrounding the vein, its tissue region, and around regional lymph nodes. This is seen from bright specific fluorescence of individual cells in the walls of lymphatic vessels and all vascular layers and valves in UV light.

Background: The aims of this study were to evaluate the effect of poloxamer 407 administration on atherogenic serum lipoprotein fractions and subfractions associated with cholesterol, triglycerides and phospholipids, as well as the onset of early atherosclerosis, in mice., Methods: Mice were administered either sterile saline or poloxamer 407 (to induce a dose-controlled hyperlipidemia) for 1 month and then sacrificed at 1, 4 and 10 days after the last dose of poloxamer 407. Systolic and diastolic blood pressure, the activity of a cysteine protease (cathepsin B) in cardiac and liver tissue, and histological/morphological examination of heart and liver specimens was performed for each group of mice at each time point. Lastly, small angle X-ray scattering was utilized to analyze the lipoprotein fractions and subfractions associated with cholesterol, triglycerides and phospholipids for both groups of mice at each time point. Statistical analysis was performed using one-way, analysis-of-variance with post hoc analysis to determine significantly different mean values, while correlation analysis employed the Spearman test., Results: Poloxamer 407-treated mice revealed significant hyperlipidemia, moderately elevated blood pressure, general lipidosis in liver cells, increased cysteine protease activity in heart tissue, and contractile-type changes in cardiomyocytes. Similar to humans, the onset of atherosclerosis in poloxamer 407-treated mice was characterized by a steady increase in serum low-density, intermediate-density and very-low-density lipoprotein fractions, as well as very-low-density lipoprotein subfractions., Conclusions: We would propose that the sustained elevation of serum atherogenic lipoprotein fractions and subfractions induced by the administration of poloxamer 407 to mice resulted in the morphological changes we observed in both heart and liver cells, which are suggested to precede atherosclerosis, since this is a well-established mouse model of atherosclerosis. Since most of the cellular, biochemical and physiological changes documented in the present study using poloxamer 407-treated mice are related to the symptoms of early atherosclerosis in humans, it is suggested that the poloxamer 407-induced mouse model of hyperlipidemia and atherosclerosis might prove beneficial as an experimental animal model with which to evaluate the pathological features observed in early-stage atherosclerosis.

The reactions of the regional lymph nodes, caused by implantation of the autologous multipotent stromal cells of bone marrow origin (AMSCBMO) to accelerate the healing of mandibular bone defect were studied by fluorescent microscopy in inbred male Wag rats aged 6 months (n=62). After the introduction of polyhydroxyalkanoate transplant containing adsorbed AMSCBMO with a transfected Green Fluorescent Protein (GFP) gene into a damaged bone area, the lymphoid nodules in submandibular lymph nodes demonstrated the appearance of numerous large macrophages containing multiple oval fluorescent inclusions in the cytoplasm. The number of these macrophages increased within 2 weeks after surgery and then began to decline. Apparently, AMSCBMO introduced in this way, were partially absorbed by macrophages. After destruction of the structures formed from AMSCBMO, the debris was also phagocytized by macrophages. In either case, these macrophages appeared in the germinal centers of lymphoid nodules in lymph nodes, where the induction of immune responses against DNA and GFP protein was probable.

The features of submandibular lymph node (LN) reactions after lower jaw tissue damage at old rats were studied by method of light microscopy. In LN of old rats for all terms of observation, including intact control, the volume of connective tissue is considerable increased. Besides, old animals in LN have of more change duration of a cortical plateau volume, less - of paracortex and lymphoid nodules without light centers. Features of cellular element number consisted in considerable decrease in quantity of lymphocytes, mitotic figures, immunoblasts and plasmablasts against increase in keeping of macrophages, cells with destruction, stromal elements and erythrocytes.

Numerous and often contradictory research results specify that the mechanism of increased susceptibility to diseases in old age has no satisfactory explanation so far. Together with it in literature almost completely there are no comparative data on features of surgery and injury influence on a structure and functions of lymphoid organs at patients of different age groups. However, lymph nodes are a marker of activity of inflammatory process in the region, on their changes it is possible to estimate precisely productivity of different medical actions, to predict development of many complications, and, thus, successfully to take actions for their prophylaxis. All this is especially important and actual because of constant increase in average age, in life expectancy of human population and strengthening of surgical activity at patients of advanced and old age.

The possibility of pregnancy and labor was evaluated and tissue changes after injection of autologous bone marrow multipotent mesenchymal stromal cells with transfected GFP gene were studied in rats with experimental hydrometra. Injection of stromal cells to the uterine cicatrix increased the number of vessels (vascular walls or their elements) formed de novo with participation of injected cells. The animals produced progeny 2 estrous cycles earlier, the percentage of "puerperal" rats in this group was higher, their progeny was more numerous and they had the maximum numbers of little rats. The maternal mortality was lower after injection of stromal cells. Injection of stromal cells led to development of a trend to more rapid reparative processes in the uterus in animals with cicatricial stenosis of its lumen.

The results of transplantation of autologous bone marrow multipotent mesenchymal stem cells carrying GFP gene and labeled with cell nucleus-specific dye DAPI near the thrombosed vein in rat hind limb were studied by methods of luminescent microscopy. It was demonstrated that autologous multipotent mesenchymal stem cells participate in the formation of granulations at the site of surgery. The blood fl ow in the thrombosed great vein was always restored through thrombolysis. We observed no signs of incorporation of the transplanted cells into the wall of the great vessel, clot recanalization, or formation of collaterals. Small branches of the great vein in the affected region were also thrombosed. The blood fl ow in these branches was always restored with participation of the transplanted cells or through clot recanalization or through obliteration of the thrombosed vessels and formation of new vessels. The transplanted cells and structures formed by them were gradually replaced by the recipient cells.

In the male Wag rats aged 6 months with the body mass of 180-200 g the luminescent microscopy was used to examine the possibility of lymphatic vessel formation after injection into thrombosed vein of the thigh of autologous multipotent stromal cells of bone marrow origin (AMSCBMO) transfected with green fluorescent protein gene. Animals were sacrificed 4 days and 1, 2, 3, 4 and 5 weeks after the injection of AMSCBMO. The control group consisted of intact rats, animals with venous thrombosis receiving no injection of AMSCBMO and those injected with AMSCBMO but without the prior modelling of venous thrombosis. In each experimental and control groups at each time point 11-12 animals were used (total number equal to 226). After the main vein ligation with the subsequent injection of thrombin solution, in addition to the thrombosis of the blood vessels, morphological signs of thrombosis of the lymphatic bed and lymphostasis were present: the dilation of lymphatic vessel lumen, thinning of their layers, intense staining of their luminal heterogeneous content. AMSCBMO, injected into thrombosed vein, were found to directly participate in lymphangiogenesis in the connective tissue around vein, its tissue region and in the area of regional lymph nodes. This is indicated by bright specific luminescence of both individual cells in the wall of the lymphatic vessels, and all their tunics together with the valves, when exposed to UV light.

Methods of light microscopy were used to study the morphological changes of the oral cavity mucosa in rats (n = 48) in chronic renal failure (CRF) of various degrees. It was found that after 6 months of modeling of mild and moderate CRF, lamina propria of the oral cavity mucous membranes was diffusely infiltrated with leukocytes. At the same time, relative density of the distribution of the components of blood and lymphatic vascular bed was increased. In severe CRF, the atrophy and hyperkeratosis of the epithelium of the oral cavity mucous membrane developed, while the lamina propria demonstrated sclerosis and significant increase of leukocyte (primarily neutrophil and monocyte) and macrophage numerical density with the formation of small leukocyte infiltrates. In addition, in moderate and severe CRF, the number of eosinophils and plasma cells was increased in the lamina propria which indicates the possible presence of allergic component in the initiation and maintenance of its inflammation.

The uterine tissues of female rats (n=30) with a scarred myometrium were examined by methods of light microscopy after the delivery. 1.5-2 months after the delivery no significant differences in the parameters of blood and lymph flow in the deep layers of the endometrium, myometrium and the myometrial scar tissue were found between the intact rats, nulliparous rats with a scarred uterus, rats that gave birth after laparotomy only and those that gave birth under the conditions of myometrial scar. In the course of pregnancy and labor activity, the damage of the tissues was observed not in the uterine scar proper, but at its borders with the myometrium. This is supported by the old hemorrhages and lymphostasis phenomena, greater number of lymphocytes, neutrophils, monocytes, macrophages and erythrocytes. In determining the indications and contraindications to vaginal childbirth in women with scarred uterus it is necessary to examine not only the scar proper, but also its border with the myometrium. The myometrial scar by itself, is not an absolute contraindication to vaginal delivery, the natural delivery is feasible in the absence of cavities with liquid and hemorrhages in the tissues of the uterine scar and at its border with myometrium.

The effects of the injection of autologous multipotent stromal stem cells of bone marrow origin (MSSCBM) (mesenchymal stem cells) with green fluorescent protein gene, additionally marked with DAPI nuclear stain, close to a thrombosed hindlimb vein, were studied by fluorescent microscopy in adult male Wag rats (n = 214). The control groups consisted of intact rats (n = 12), animals with venous thrombosis without the injection of MSSCBM (n = 71) and rats that received paravasal injection of MSSCBM, but without preliminary modeling of venous thrombosis (n = 72). It was found that MSSCBM participated in the development of granulation tissue at the site of surgical intervention performed during the modeling of thrombosis. The rapid development of granulation tissue at the site of surgical trauma may contribute to faster wound clearance from detritus, nonviable tissue and antigenic substances, early onset of tissue repair processes and rapid healing. Restoration of blood flow in the tissue region of a thrombosed vein began later than after the intravenous injection of MSSCBM.

Morphological changes in tissues adjacent to the implant were studied 1, 2, 6, and 12 months after implantation of biodegradable suture materials (catgut thread, DemeTECH polyfilament thread, and Surgilactin monofilament thread) into subcutaneous fat of rats. Tissue reaction to implantation of different suture materials developed as usual in response to a wound process and to a foreign body. By the end of month 1. the stage of traumatic perifocal inflammation was replaced in all groups by the proliferative phase with formation of new vessels and connective tissue. A trend to reduction of the productive inflammation activity from month 1 to month 12 was noted. Complete degeneration of the material after 12 months with complete recovery of the histoarchitecture of the adjacent tissues (restitution) was detected only after implantation of DemeTECH polyfilament thread.

Polylactide degradation processes after its implantation into the subcutaneous fat of rats were studied by microscopy. After implantation polylactide was encapsulated in connective tissue. If a fragment of polylactide had sharp edges, injuring the tissue, a thick capsule formed with pronounced inflammatory infiltration and sclerosis of adjacent tissues. If the implant had no sharp edges, the capsule was thin and the level of inflammation the minimum. Foreign body giant cells were found in the capsule and near it in all cases. The activity of the inflammatory process gradually reduced over 6 months. The intensity of inflammation sharply increased by the 12th month after implantation, when activity of phagocyte enzyme and deformation by the capsule led to fragmentation or liquefaction of polylactide.

The method of light microscopy was used to study the reactions of the surrounding tissues to the implantation of non-degradable surgical materials (prolene 3/0 thread made from polypropelene, the composite grid made from polypropelene or polyester with polylactic acid) in the subcutaneous adipose tissue of rats 1, 2, 6 and 12 months after grafting. No less than 6 rats were examined in every time point. It was shown that the tissue reactions to implantation of different non-degradable surgical materials follows the general pattern, characteristic of wound process and foreign body reaction. By the first month of observation in both groups of animals the stage of traumatic perifocal inflammation was replaced by the proliferative phase with the formation of new blood vessel and connective tissue. The tendency to reduction of the activity of productive inflammation was observed from the 1st to the 12th month together with the increased fibrous scar transformation of the granulation tissue.

The reaction of various tissues of rats to implantation of polyhydroxyalkanoate films and ultrafine fibers was studied by optic microscopy. Implantation of polyhydroxyalkanoate films into the abdominal cavity caused a peritoneal reaction, leading after 1 month to the formation of fibrous adhesions between polyhydroxyalkanoate and intestinal loops. Under the skin and in the muscle tissue polyhydroxyalkanoate films were encapsulated in a thick fibrous capsule. Implantation of polyhydroxyalkanoate ultrathin fibers led to formation of foreign body granulomas in all tissues with perifocal inflammation and sclerosis of the adjacent tissues. The polymer was fragmented in these granulomas and phagocytosed by macrophages with the formation of giant foreign body cells. Hence, polyhydroxyalkanoate materials implanted in vivo caused chronic granulomatous inflammatory reaction and were very slowly destroyed by macrophages.

Tissue reactions, accompanying the degradation processes of polylactide (PLA) implants after their placement into the subcutaneous tissue, were studied by the methods of light microscopy in 6 month-old Wag rats (n=24) weighing 180-200 g. It was found that PLA implants became encapsulated by connective tissue. If the implant or its fragment had sharp margins that damaged the tissues, a thick capsule was formed with a distinct inflammatory infiltration and the sclerosis of the surrounding tissues. If the implant had no sharp margins, the capsule was thin, and the activity of inflammation was minimal. In all cases, the giant cells of foreign body type were present in the capsule and next to it. Gradually, during 6 months, the activity of inflammatory process subsided. Inflammation sharply increased 12 months after the implantation, when, as a result of effect of enzymes released by phagocytes and deformation by a capsule, PLA implants were either fragmented or is liquified. PLA-based materials are not totally biodegradable, and may persist in the body for a long time.

Regeneration processes in rat mandibular bone after transplantation of a suspension of autologous BM MSC in culture medium were studied by methods of light microscopy and X-ray densitometry. It was found that the structures of red BM in the callus after transplantation of autologous BM MSC formed earlier than in natural reparation. The formation of cavities containing BM determines lower tissue density at the site of injury after transplantation of autologous BM MSC on weeks 4 and 5 of observation than during spontaneous healing. These changes progressed throughout the observation period and attested to accelerated bone tissue reparation.

Scientific literature about the use of MSC contains clinical and experimental data on the efficiency of cell technologies for restoration of the osteoarticular apparatus. The use of MSC immobilized in the appropriate carriers and differentiation of these cells towards the bone cells and chondrocytes are of crucial importance. However, the use of MSC, both individual and in combination with other preparations and substances has a number of drawbacks and advantages. The absence of published reports on contraindications and complications of cell therapy is worthy of note, because the analysis of unsuccessful application of MSC will help to determine the indication for this treatment, and hence, to improve the efficiency of cell technologies in the future. Wider use of MSC in clinical practice and experimental studies for acceleration of reparative processes in the bone and cartilage tissue seems to be promising.

Results of injection of autologous bone marrow mesenchymal stem cells with transfected GFP gene into the rat uterine horn cicatrix were studied by light microscopy. Large groups of blood vessels with blood cells inside were seen after injection of autologous bone marrow cells into the cicatrix on the right horn, formed 2 months after its ligation; no groups of vessels of this kind were found in the cicatrix in the contralateral horn. Examination of unstained sections in reflected UV light showed sufficiently bright fluorescence in the endothelium and outer vascular membrane in the uterine horn cicatrix only on the side of injection. Hence, autologous mesenchymal stem cells injected into the cicatrix formed the blood vessels due to differentiation into endotheliocytes and pericytes. The expression of GFP gene not only in the vascular endothelium, but also in vascular outer membranes indicated that autologous mesenchymal stem cells differentiated in the endothelial and pericytic directions.

Remodeling and cytograms of pararectal lymph nodes were studied in patients with rectal cancer after neoadjuvant therapy by different protocols. Radiotherapy and its combination with chemotherapy lead to an increase in the volume of connective tissue components and significant reduction of the volume density of lymphoid follicles without germinative centers. The counts of dividing cells, immunoblasts, and plasmoblasts in various compartments of the pararectal lymph nodes changed more significantly after radiotherapy, while changes in the count of monocytes and neutrophils were more pronounced after cytostatic therapy combined with exposure to ionizing radiation. These differences can be explained by the systemic toxic effect of chemotherapeutic drugs and primarily local cytotoxic effects of radiotherapy manifesting largely at the site of exposure.

The structure of gingival mucous membrane leukocytal infiltration of 80 patients with chronic apical periodontitis of different age groups was studied by the light microscopy with the use of monoclonal antibodies to CD38. It was disclosed that in gingival tissues of practically all patients 2 types of leukocytal infiltration were present with low number of plasmatic cells and high number of neutrophils (true leukocytal infiltration) and structures with high number of plasmatic cells and low number of neutrophils - most likely lymphoid follicle resultant in mucous membranes of different organs in cases of chronic inflammation. In epithelial gingival paving in cases of chronic apical periodontitis CD38(+)-cells were absent.

Rat liver, small intestinal wall, mesenteric, mediastinal, and popliteal lymph nodes of rats were studied by indirect immunoperoxidase method with monoclonal antibodies to cytochrome P-450 1A1/1A2. These cytochrome forms were detected in low concentrations in hepatocytes, macrophages of the small intestinal villi and mesenteric and mediastinal lymph nodes of intact animals. Basal induction of monooxygenase enzymes can be caused by cytochrome inductors entering with air (environmental pollution) or food.

The mesenteric, mediastinal, and popliteal lymph nodes of rats were studied by indirect immunoperoxidase method using monoclonal antibodies to cytochrome P450 1A1/1A2 after oral treatment with benzo[a]pyrene. These cytochrome forms were detected in monocytes, macrophages, reticular and littoral cells, cell detritus, and liquid contents of the paracortical and medullary sinuses of all studied lymph nodes. The results indicate that exo- and endogenous toxic substances are oxidized not only in the liver, but also in lymph nodes.

Studies of mesenteric lymph nodes of rats by indirect immunoperoxidase method using monoclonal antibodies to cytochrome P450 1A/1A2 after oral dose of benzo[a]pyrene showed the presence of these cytochrome forms in monocytes, macrophages, reticular and litoral cells, cell detritus, and liquid contents of the paracortical zone and medullary substance sinuses. Oxidation of various exo- and endogenous toxins in the lymph nodes was revealed.