INFLUENCE OF CHRONIC NON-GASEOUS ACIDOSIS ON BONE TISSUE

The urgency of the problem is due to the high prevalence among the population in all countries of the world and socio-economic losses associated with serious complications of osteoporosis. Chronic non-gaseous acidosis leads to disruption of many metabolic processes, which causes dysfunction of some organs, namely, can lead to decreased kidney function, exacerbate cardiovascular disease, the development of osteoporosis. Different types of non-gaseous acidosis are accompanied by changes in protein metabolism, which lead to the development of osteoporosis. Aim: to study the structural features of the bone tissue of the femur in chronic non-gaseous acidosis. Methods. The experiments were carried out on 60 intact white outbred male rats weighing 120-180 g, which were kept on a balanced diet of vivarium. Chronic non-gaseous acidosis was simulated by daily intragastric administration with a probe for 60 days 20 mmol/kg NH4CL. The control animals were injected with the same amount of tap water. Histological examination and osteometry were used to study the structure, length and thickness of the rat femur. Free, bound, and total oxyproline in rat urine was determined by biochemical method. Results. In chronic non-gaseous acidosis after 6 months there is a tendency to reduce the length and thickness of the femur, but does not differ significantly from the control group. In the urine of rats of the experimental group, the total oxyproline increases mainly due to an increase in free oxyproline, which indicates the predominance of collagen degradation over repair. The histological structure of the bone is disturbed due to the thinning of the bone beams, the intercellular matrix is disorganized, in some places there is its "defibering" with the formation of foci of destruction and cylindrical "lumens". There is a violation of the crystalline structure of bone tissue, its uneven calcification, the formation of cracks in the bone beams. Studied literature sources and our research indicate that chronic non-gaseous acidosis has a pathogenic effect on the histological structure of bone. Acidosis is a stress factor that increases the level of glucocorticoids. Glucocorticoids inhibit type I collagen synthesis and increase the expression of collagenase 3, which promotes collagen degradation. Collagen is a source of amino acids that are the substrate for renal ammoniogenesis. Renal ammoniogenesis is a compensatory mechanism in chronic non-gaseous acidosis, which required for restores the normal ratio between fixed cations and anions blood plasma. Thus, the violation of the organic basis of bones is the body's adaptation to chronic non-gaseous acidosis. Conclusions. Chronic non-gaseous acidosis simultaneously leads to thinning and disorganization of the intercellular matrix, disruption of the crystal structure of bone tissue, which indicates its important role in the development of osteoporosis. In chronic non-gaseous acidosis, the concentration of oxyproline in the urine increases, which is a marker of the destruction of collagen in the organic matrix of bone.

New aspects in the pathogenesis of miscarriage in women with extragenital pathology

Study objective: to determine the dynamics of type 9 metalloproteinase (MMP-9) and its tissue inhibitor-1 (TIMP-1) in the pathogenesis of early miscarriage in women with chronic diseases of the hepatobiliary system.Materials and methods. The study included 39 women with a history of early pregnancy miscarriage, who were diagnosed with chronic liver diseases as a result of clinical, instrumental and laboratory studies (17 persons with steatosis and 22 persons with non-alcoholic steatohepatitis). The control group consisted of 8 women without somatic pathology and 8 pregnant women at the first trimester of gestation. MMP-9 and TIMP-1 value in the blood serum was determined by the enzyme immunoassay.Results. MMP-9 and TIMP-1 growth in the blood serum of women with a history of miscarriage was established in the pre-gravidar period. The most significant increase in the parameters of the intercellular matrix was found in patients with non-alcoholic steatohepatitis. MMP-9 and TIMP-1 increased in in blood serum in the first trimester in women with liver diseases. MMP-9 increased against the background of a decrease in the TIMP-1 activity in patients with the threat of premature pregnancy termination. Miscarriage was diagnosed in patients with a minimum value of a tissue inhibitor. Conclusions. There is an imbalance between MMP-9 and TIMP-1 in the blood serum in women with early miscarriage and chronic diseases of the hepatobiliary system. MMP-9 and TIMP-1 level in patients with hepatic steatosis is lower than in patients with non-alcoholic steatohepatitis. MMP-9 increased during physiological pregnancy, and the TIMP-1 activity practically did not change, which indicates the role of MMP-9 in the initial stages of placentation. MMP-9 value in women with a burdened premorbid background with a physiological course of pregnancy and threatening early spontaneous miscarriage was significantly different. The highest activity of MMP-9 was in women with the threat of spontaneous miscarriage in the early stages. TIMP-1 in the first trimester in women with chronic liver disease increased in those with a favorable course of pregnancy and decreased in the threat of spontaneous miscarriage. Such changes in MMP-9 and TIMP-1 in patients with miscarriage indicate the accumulation of intercellular matrix and sclerotic changes in the vessels that provide blood to the uterus.

A rare case of hypodysfibrinogenemia in patient without hematomesenchymal dysplasia

Фибриноген и коллаген являются важнейшими протеинами межклеточного матрикса, оказывающие прямое влияние как на дифференцировку мезенхимальных стволовых клеток, так и на остеогенез. Кроме того, в клинической практике встречаются случаи протекания данного синдрома не в классическом виде, которые требуют более углубленного изучения звеньев патогенеза и разработки оптимальной коррекции заболевания. Нами проведен поиск литературных данных по ключевым словам в базах данных PubMed, UpToDate, BMJ. Представлен обзор современных научных данных и результаты наблюдения редкого клинического случая у пациента с гиподисфибриногенемией с проявлениями асептического некроза головок бедренных костей без гематомезенхимальной дисплазии. Заключение: В целом, в настоящее время подробно изучены различные аспекты клинико-биохимического патогенеза аномалий фибриногена, но остаются «белые пятна» в изучении тонких патогенетических механизмов на молекулярно-генетическом уровне, а именно: катаболизм белка, реакции раздельного синтеза отдельных полипептидных цепей фибриногена в разных тканях. Остается нерешенным вопрос о целесообразности применения корригирующих гемостаз препаратов таргетного действия при отсутствии у пациента выраженных тромботических и геморрагических проявлений. Fibrinogen and collagen are the most important intercellular matrix proteins that directly effect on the differentiation of mesenchymal stem cells and osteogenesis. In addition, there are non-classical cases of this syndrome that require indepth study of pathogenesis and optimal disease correction. We examined literature data by keywords in databases PubMed, UpToDate, BMJ. We presented a review of current scientific data and observation results of a rare clinical case in a patient with hypodysfibrinogenemia without hematomesenchymal dysplasia with manifestations of aseptic necrosis of femoral heads. Conclusions: In general, various aspects of clinical and biochemical pathogenesis of fibrinogen abnormalities are currently studied in detail, but there are “white spots” in the study of sophisticated pathogenetic mechanisms at the molecular genetic level, namely protein catabolism, the reaction of separate synthesis of individual fibrinogen polypeptide chains in different tissues. Unresolved is the question of applicability of hemostatic corrective drugs in the absence of expressed thrombotic and hemorrhagic manifestations.

EVALUATION OF THE INFLUENCE OF CULTURING ON THE INTENSITY OF BIOFILM FORMATION BY KLEBSIELLA PNEUMONIAE STRAINS

Due to the prevalence of biofilm infections caused by Klebsiella pneumoniae, in laboratory diagnostic practice it has a great importance to obtain a standard model of Klebsiella biofilm for evaluating the bactericidal effect and effectiveness of antimicrobial drugs. Describes the method of Klebsiella biofilms formation in vitro. The intensity of biofilm formation was evaluated by the ability of bacteria to bind the crystal violet. The degree of film formation was measured by optical density. The presence of an intercellular matrix was confirmed by staining of Congo-red solution followed by light microscopy. The effect of exogenous and endogenous factors on biofilm formation by K. pneumoniae strains was investigated. The influence of the nutrient composition, the age of the culture («daily», «weekly»), the presence of oxygen and the temperature conditions were studied. The nutrient composition of the medium significantly influenced on biofilm formation of K. pneumoniae: DMEM stimulated biofilm formation in most strains in vitro compared to TSB. The age of the culture (daily, weekly) did not significantly affect the biofilm formation of Klebsiella. At the same time, the temperature of culturing and the presence of oxygen can both stimulate and inhibit biofilm formation, depending on the strain under study. Most strains of Klebsiella better form a biofilm under aerobic conditions at 37º C.

DELAYED COGNITIVE DEFICIT AS A RESULT OF NEONATAL LIPOPOLYSACCHARIDE EXPOSURE: A PRESUMABLE IMPLICATION OF LONG-LASTING CHANGES OF NEUROPLASTIC GENE EXPRESSION

Disorders of the CNS development at an early age caused by various types of perinatal pathology, such as infectious diseases, trauma, hypoxia and ischemia, often lead to the development of cognitive brain dysfunctions in adulthood. Proinflammatory cytokines play key role in these pathological processes and can affect the expression of genes involved in the regulation of neuroplasticity. This article describes the changes in the expression of fibroblast growth factor-2 (Fgf2), as well as genes encoding matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), proteins that by intercellular matrix re-modeling are involved in the regulation of neuroplasticity.

Noncanonical effects of vasopressin in angiogenesis

The molecular action of vasopressin depends on the localization of hormonal receptors. The basic physiological effects of vasopressin are manifested in the blood vasculature, renal inner medulla and brain. To date, new information concerning the tissue-specific spreading of vasopressin receptors has been accumulated, and it needs to be summarized. Platelets and endotheliocytes expressing V1a and V2 receptor types, respectively, are related to less investigated targets of the hormone. Vasopressin induces the initial reversible stage of platelet activation, required for interaction with intercellular matrix proteins. Platelet adhesion on endothelium activates cellular secretion of growth factors and enzymes for intercellular matrix glucosamine metabolism. Platelet hyaluronidase HYAL2 hydrolyses high-molecular hyaluronic acid to shorter fragments. Unlike intact hyaluronic acid with a molecular weight of several megadaltons, generally showing distinctive antiangiogenic properties, intermediate fractions of hyaluronan hydrolysis in a range from 2.5 to 200 kilodaltons have a stimulating effect on angiogenesis. Intercellular contacts between platelets and endotheliocytes are stabilized due to adhesive transmembrane glycoprotein PECAM-1 interaction. Resulting PECAM-1 heterodimers acquire conformation with high affinity to integrins αvβ3. Integrin activation forms contact links between endothelium and fibrillar proteins. Activated endotheliocytes secrete von Willebrand factor and P-selectin. These proteins are accumulated in Weibel–Palade bodies. Vasopressin stimulates cAMP-dependent ACAP-regulated exocytosis of Weibel–Palade bodies. von Willebrand factor possesses adhesive properties and additionally accelerates interaction of cells with the intercellular matrix. Adhesion on fibrillar collagen and membrane glycoproteins in cooperation with effects of PECAM-1–αvβ3 integrin complexes fixes cell aggregates in the surrounding interstitium and promotes proliferating endotheliocyte migration in according to the direction of local growth factor gradients during angiogenesis. Neurohormonal regulation of platelet and endotheliocyte secretory activity functionally link proliferation and migration of endotheliocytes during angiogenesis and integrate it according to the adaptive capacity of the entire organism.

Morphofunctional characteristics and immunological regulation of the orbital fibroblasts function in endocrine ophthalmopathy

Endocrine ophthalmopathy (EOP) is a chronic disease characterized by progressive autoimmune inflammation of the soft retrobulbar tissues in thyroid dysfunction. The orbital fibroblasts with their unique morphofunctional properties are very important in the pathogenesis of the infiltrative process and fibrosis of the extraocular muscles and/or retrobulbar tissue. They, unlike other localization fibroblasts, have not mesodermal, but neuro-ectodermal origin. The review acquaints with the immunological aspects of the regulation of these cells in different activity phases of disease. Intercellular interaction with T-lymphocytes (CD40-CD154) leads to orbital fibroblasts activation with increased expression of pathological receptors for thyroid-stimulating hormone, as well as production of intercellular matrix components, adhesion molecules, growth factors, cytokines and prostaglandins. Detailed morphofunctional characteristics of the orbit fibroblast subpopulations and mechanisms regulating their transdifferentiation into adipocytes and myofibroblasts are given. The analysis of literature data on the effect of T-helper type 17 on the functional activity of Thy1+/Thy1- (CD90+/CD90-) orbital fibroblasts is presented. The importance of the further study of the orbital fibroblasts characteristics in EOP and their intercellular interaction with various immune cells was noted, which may be able to uncover new pathogenetic mechanisms of this pathology.

Molecular Biological Peculiarities of the Must Cells Secretome of the Lower Limb Skin in Trophic Ulcers of Various Etiologies

The purposeof this research was to study characteristics of the mast cell (MC) secretome of the skin of the lower extremities in patients with trophic ulcers of various etiologies.Material and methods.The study included patients with venous, arterial and neurotrophic ulcers, as well as patients with the normal skin of the lower extremities. Skin specimens were stained by toluidine blue using histochemical techniques and Romanowsky–Giemsa staining; immunohistochemical protocols were used to detect MC tryptase and chymase, including the technology of multiple immune-labeling. Skin sections were studied using a ZEISS Axio Imager.A2 microscope (Carl Zeiss, Germany).Results.In the skin of patients with chronic arterial and, especially, venous insufficiency, the number of protease-containing MCs and chymase expression in the skin increased compared with the similar indicators of the skin without pathological changes. Activation of the protease secretory pathways in MCs was manifested by the release of separate tryptase and chymase-positive granules, and by the formation of granule-containing fragments of the cytoplasm. The group of patients with neurotrophic ulcers was characterized by the most expressed growth in the volume of the MC population in the skin with the increase of their size, activity of the secretory pathways and signs of polymorphism. Infiltration of the skin by MC spread into the epidermis with intensive secretion of proteases into the area of tight junctions and the intercellular matrix of the basal and spinous layers.Conclusion.MC specific proteases in chronic ulcers of the lower extremities of various etiologies may be used as an informative marker of inflammatory progression degree in the skin not only for diagnostic purposes and monitoring the effectiveness of the performed therapy but also as a promising target for pharmacological agents.

Discogenic pain

Discogenic pain in the back presents certain difficulties both in clinical diagnosis and in understanding pathogenesis. In recent years, several significant mechanisms of the pathogenesis of this type of back pain have been disclosed. it has been shown that the key factors for its development are increased expression of the cytokine iL-1b and other inflammatory mediators, which destroy the intercellular matrix of the disc and inhibit the production of proteoglycans. Pathological angio- and neurogenesis, developing in the intervertebral disc, which normally is aneuricular and avascular, are the main pathophysiological mechanisms of discogenic pain. Based on a number of analyzed works, it can be concluded that preparations containing chondroprotectors (symptomatic slow-acting drugs in osteoarthritis, SYSADOA) are able to influence these key pathogenesis of discogenic back pain.

HIFα as a target for different oncoproteins during carcinogenesis

The basic characteristics of tumours are ability for invasiveness and metastasis. These properties are realized due to destruction of intercellular matrix caused with acidification of intercellular area stimulated with transition from tissue respiration to glycolysis. The transition to glycolysis in tumor cells is observed not only during hypoxic state how is realized in normal cells but also during oxygenation (Warburg effect). It is accepted that by any carcinogenic action the activation of oncogenes or inactivation of genes – supressors occurs. As a result it is permanent expression of oncoproteins and stimulation of tumour development. Different oncoproteins operate in different regulation systems at that they cause the same effect – tumour development.It is assumed that oncoproteins are not the ultimate factor in tumour development but there are existed some common element which is activated by different oncoproteins. In this review it is assumed that common element is HIFα (hypoxia-inducible factor α) transcription factor and it is discussed the mechanisms its activation by oncoproteins takes place in different signal systems.