Evaluation of Advantages of Lithium Chloride as a Precipitating Agent in RNA Isolation from Frozen Vein Segments.

Contamination of the sample with DNA is a problem when isolating RNA by phenol-chloroform extraction, and DNase treatment introduces an additional error in the analysis of gene expression. Bearing in mind the ability of LiCl to precipitate RNA selectively, we studied the possibility and advantage of using LiCl as a precipitation agent in the protocol for RNA precipitation [3] from frozen segments of large vessels. Combined use of LiCl with isopropanol as precipitating agents (optimal ratio 2.5 M and 40%, respectively) significantly eliminates negative effects of using this salt (inhibition of reverse transcription and low RNA yield).

[Current trends of the choice and processing of materials for dental implantation]. / Sovremennye tendentsii vybora i obrabotki materialov dlia dental'noi implantatsii.

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.

Polymorphism of Matrix Metalloproteinases Genes MMP1, MMP2, MMP3, and MMP7 and the Risk of Varicose Veins of Lower Extremities.

We studied the effects of single nucleotide polymorphisms in the promoter regions of matrix metalloproteinase genes rs1799750 (-1607dupG) MMP1, rs243865 (C-1306T) MMP2, rs3025058 (-1171dupA) MMP3, and rs11568818 (A-181G) MMP7 on the risk of varicose vein of the lower extremities in ethnical Russians, residents of the Russian Federation. We genotyped 536 patients with this pathology and 273 healthy participants without history of chronic venous disease. Association was examined using logistic regression analysis. None of the studied polymorphisms showed statistically significant association with the risk of varicose veins of the lower extremities. Our results provide evidence that these polymorphisms are not involved in the pathogenesis of varicose veins and cannot serve as markers of predisposition to this pathology.

Polymorphic Variants rs13155212 (T/C) and rs7704267 (G/C) in the AGGF1 Gene and Risk of Varicose Veins of the Lower Extremities in the Population of Ethnic Russians.

We analyzed associations between single nucleotide polymorphisms (SNP) rs13155212 and rs7704267 in the AGGF1 gene (angiogenic factor with G patch and FHA domains 1) and the risk of risk of varicose veins of the legs in ethnic Russians. Frequencies of alleles, genotypes, and haplotypes were estimated in the sample of patients with this disease (474 patients) and in the control group of participants (478 volunteers) without a history of chronic venous disease. None of the studied polymorphisms was associated with the risk of this pathology. The whole AGGF1 gene sequence lies in a single block of high linkage disequilibrium, and both studied polymorphic variants are representative of all other SNP within this region. From these results, a conclusion was made that AGGF1 gene polymorphism does not affect the risk of varicose veins of the legs in ethnic Russians, or its contribution is low and can be revealed only after analysis of larger cohorts.

[Algorithm for selection of individual therapy with clopidogrel in vascular surgical practice]. / Algoritm podbora individual'noi terapii klopidogrelom v praktike sosudistogo khirurga.

For treatment of patients with diseases of lower limb arteries and prevention of cardiovascular complications in high-risk patients (those with diabetes mellitus, arterial hypertension, dyslipidemia, obesity) permanent antiplatelet therapy is indicated. A problem is variable individual sensitivity to therapeutic agents. For antiplatelet therapy in patients with atherosclerosis of lower limb arteries there has been obtained an evidence-supported base concerning efficacy of long-term administration of clopidogrel preparations, unlike patients with acute coronary syndrome, for whom there has been accumulated an evidence-confirmed base of administering clopidogrel preparations, as well as ticagrelor and prasugrel in various clinical situations. Clopidogrel is currently the best known representative from the group of thienopyridines. It is a pro-drug and has complicated metabolism: two-stage oxidation under the effect of isoforms of cytochrome 2C19. Its active form irreversibly inhibits binding of ADP with P2Y12 receptors of thrombocytes. This is followed by inhibition of binding of fibrinogen with the glycoprotein IIb/IIIa receptor and a decrease of aggregation. Determining blood platelet aggregation with ADP, collagen and arachidonic acid forms the basis of clinical assessment of the functional state of thrombocytic activity and may be a marker of efficacy of treatment with antiaggregants. A complicated mechanism of action of clopidogrel implies individual policy of the attending physician in making a decision concerning the duration of therapy and selection of the dose. These prerequisites resulted in working out a recommended algorithm of individual dosing of clopidogrel (based on the analysis of case histories of patients with atherosclerosis of lower limb arteries by the level of platelet aggregation to a series of inducers) and correction of the dose of the drug based on the results of molecular-genetic testing of the cytochrome CYPC19 gene. The algorithm makes it possible to achieve a maximum level of efficacy and safety of treatment with antiaggregants.

Reaction of rat tissues to implantation of lactic acid-based biodegradable polymer.

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.

Local tissue reaction to implantation of biodegradable suture materials.

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.

[Peculiarities of tissue reactions to implantation of non-degradable surgical materials].

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.

[Tissue reactions to the use of implants manufactured from lactic acid polymers].

Recent literature on the morphological results of the application of polymers produced from lactic acid (polylactides--PLA), contains a plethora of experimental and clinical data on the efficiency and safety of their use for the medico-biological purposes. However, the question on the actual rate of biological disintegration of PLA materials remains unanswered. There are conflicting views on the inflammatory reaction ranging from a complete negation of an inflammatory response to PLA implantation up to the reports describing the expressed aseptic inflammatory reactions caused by presence of this material in tissues. Some researchers report the total absence of the foreign-body reactions to this class of implants, while some others indicate the obligatory formation of the foreign-body giant cells. Further research is necessary to precisely predict degradation processes of and to detect all the potential risks associated with the use of PLA-based materials.

Reaction of the rat tissues to implantation of polyhydroxyalkanoate films and ultrafine fibers.

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 during the degradation of polylactide implants in the body].

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.

[Morphological tissue changes after the implantation of a biodegradable material on collagen basis].

The objective of this study was to examine the peculiarities of tissue reactions during the degradation of "Collost" bioplastic material on the collagen basis with completely preserved fibrous structure, after its implantation into the bone tissue defect. The defect in bone tissue sized 1-2 mm x 3-5 mm was created in tibial condyle. The study was performed on 24 Wistar rats using light microscopic methods. The tissue reactions were studied at different time intervals (1, 2, 6 and 12 months) after the implantation of collagenic material. It was found that after the implantation, the material became impregnated with blood, and due to fibrin, densely adhered to the damaged tissues. Further, the cells were found to migrate along the blood clot into its depth from the surrounding tissues. These were primarily the fibroblasts which were located in a network of fibers and started to absorb collagen from a surrounding material and to synthesize new collagen. Gradually, the collagenic material became similar to a cell-containing network. The volume of the newly synthesized collagen increased, and after some time all the foreign material was absorbed by fibroblasts and replaced with connective tissue. After 1 year, a large "Collost" fragment was completely degraded and replaced by loose connective tissue. The implantation of a collagenic material did not stimulate the formation of a delimiting connective tissue capsule

[Peculiarities of tissue reactions during resorption of biodegradable suture materials].

The reaction of the surrounding tissues to the implantation of biodegradable suture materials (plain catgut threads, DemeTECH polyglactin 910, Surgilactin--polyglactin 910) into the subcutaneous adipose tissue of rats, was studied using light microscopy 1, 2, 6 and 12 months after grafting. It was shown that the tissue reactions to implantation of different biodegradable suture materials followed the general pattern characteristic of wound healing and foreign body reaction. By the first month of observation, in all the animal groups, the stage of traumatic perifocal inflammation was replaced by a proliferative phase with the new growth of the blood vessels and connective tissue. In all the animal groups, there was a trend to reduction of productive inflammation activity from the 1st month till the 12th month. By the 12th month the total degeneration of the material with full recovery of structure of surrounding tissues (restitution) was recorded only after the implantation of polyglactin 910 (DemeTECH).

[Peculiarities of angiogenesis after the implantation of polyhydroxyalkanoate films with the adsorbed multipotent stromal stem cells of a bone marrow origin].

The processes developing in various rat tissues after implantation of polymeric polyhydroxyalkanoate (PHA) film fragments with adsorbed autologous multipotent stromal (mesenchymal) cells of bone marrow origin (AMMSCBM), were studied by methods of light microscopy. After the implantation of PHA film with AMMSCBM, the number of blood vessels in the surrounding tissues was found to increase as a result of neoangiogenesis. In this case,AMMSCBM did not migrate and were not destroyed at the place of injection, but differentiated into the cells forming blood vessel structures. The processes of angiogenesis in the tissues around PHA implant, in turn, lead to development of a larger number of blood vessels in the granulations formed around the implanted foreign body, higher volume of granulations proper and subsequent development of a thicker capsule delimiting polymer implant.

[Tissue responses to silicone materials in the body].

Light microscopy was used to study connective tissue capsules formed around different silicone breast implants. It has been found that due to the activity of microfibroblasts to minimize the volume of foreign bodies, the capsule gradually shrinks; its inner surface deforms and develops an undulating appearance with a multitude of outgrowths or protrusions inside. With the passage of time, silicone migrates to the capsule tissue and outside where it is absorbed by phagocytes. The inerter to a living organism the implant material is, the less it will stimulate a macrophage response. The task of designing new implants is to search for maximally bioinert materials that are strong enough to be compressed by the capsule and be fragmented and, moreover, elastically similar to normal breast tissue.

[Lymphatic endothelium in certain conditions].

Presented herein is a review of the literature data concerning the structural and functional peculiarities of the endothelium of the lymphatic and blood vessels. The authors consider the current state of the art of the problem regarding dysfunction of lymphatic endothelium dysfunctions developing in various diseases, as well as in the process of ontogenesis, pointing out an important role of impaired processes of lymphangiogenesis, underlying the development of diseases of the lymphatic system. The authors also assess administration of quercetine in treatment for chronic venous insufficiency, followed by suggesting a possible mechanism of its positive action consisting ina decrease in the oedema at early stages of lymphoedema.

Regeneration of red bone marrow in rat lower jaw after transplantation of mesenchymal stem cells into the site of injury.

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.

[Morphological tissue changes after the implantation of elastic lamellar foreign bodies in the experiment].

The reaction of rat tissues was studied using the methods of light microscopy 4, 12, 18 days, 1, 2, 6 and 12 months after hypodermic implantation of polymeric films made of polyhydroxyalkanoates (PHA). It was found that polymer, like any foreign matter in an organism, become immediately covered by fibrin. By day 4, there the deformation and destruction of polymeric films were observed due to fibrin contraction. Further, the foreign body was covered by a connective tissue capsule. Under the action of myofibroblasts, the capsule around PHA contracted, thus further deforming and breaking the polymer. Small particles of polymer were covered by macrophages, after some time the cytoplasm of macrophages fused forming the giant cells of foreign body type. After the prolonged period, small fragments of polymeric films were almost completely degraded by macrophages. Large polymeric fragments that were not deformed or crushed, became encapsulated by fibrous tissue and remained unchanged for long time periods.

[The effect of autologous mesenchymal stem cells of bone marrow origin on regeneration of damaged rat bottom jaw bone].

The regeneration processes after introduction in site of damaged bone of rat bottom jaw of autologous mesenchymal stem cells of bone marrow origin (AMSCBMO) in suspension were studied by methods of light microscopy and x-ray densitometry. Morphological methods showed that formation of red bone marrow in bone callosity occurs much earlier after use AMSCBMO than in the time of natural course of reparation. Formation of cavities with a marrow decreases tissue density after application AMSCBMO in a site of damage in 4 and 5 weeks of supervision. The specified changes progress during all time of observation and are the certificate of accelerated development of regenerative processes in bone tissue.

The Impact of Hypoglycemic Therapy on the Prognosis for Acute Coronary Syndrome in Patients with Type 2 Diabetes.

The article discusses particular circumstances of acute coronary syndrome (ACS) in patients with type 2 diabetes (T2D). In addition, the available literature data and clinical guidelines reflecting the role of hypoglycemic therapy as a cardioprotection factor in ACS are analyzed. The article considers possible protective molecular mechanisms of various groups of drugs in ischemic cardiomyocytes.