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Mathematical modelling of fluorine ion implantation process is carried out by using the SRIM-2008 program for the determination of quantitative characteristics of the radiation defect formation in the gadolinium–gallium garnet (GGG). The crystal depth distributions are measured for elastic and inelastic energy losses of both the implanted F+ ion with 90 keV energy and the displaced matrix ions due to their slowing-down in the GGG crystal. Depth distribution profiles are obtained for quantities of implanted and displaced ions. The damage pattern and its quantitative characteristics are determined. Structural changes caused by fluorine ion implantation in a surface layer of the GGG single crystal are investigated by an X-ray diffraction technique. The shape of the strain profile in the implanted layer and relationships of its characteristics with the simulation results are determined.

Objective: To study the immunohistochemical features of various scar tissues in children without connective tissue pathology and with undifferentiated connective tissue dysplasia syndrome., Material and Methods: Tissue biopsy was performed in 217 children who underwent surgical treatment for various lesions, such as injuries, burns, as well as other procedures. There were 127 boys (58.5%) and 90 (41.5%) girls. The main group consisted of 98 (48.2%) children with scar tissue; group of UCTD syndrome - 65 (30.0%) children; control group - 43 (24.8%) patients without pathological scars. Histological examination of scar tissue and intact skin was carried out during primary or redo reconstructive surgery. Immunohistochemical study of antibodies against CD34, CD105, CD140b, PDGFs, COL types I, III and IV was performed., Results: The study showed a quantitative characteristic of expression of COL type I in hypertrophic scar with predominance in the main group (77.5±5.4%; p <0.05), and decrease in COL type IV. Keloid form was associated with predominance of granulation tissue in all layers of dermis and high levels of all types of collagen. In the group of UCTD, COL type III prevailed in all pathological forms of the scar. We determined quantitative indicators of expression of vascularization factors (CD34; CD105) and fibroblastic activity (CD140b; PDGFs)., Conclusion: Understanding the process of fibrinogenesis and analysis of stages of triggering mechanisms are essential for development of preventive algorithms. Individualized approach should be considered in the treatment. These studies are especially important in children with UCTD syndrome as high-risk group for pathological scarring. Thus, further research is required.

Objective: Was to evaluate the effectiveness of anti-scar treatment with Contractubex gel in children and adults., Material and Methods: A group of researchers based on clinical hospitals and university medical clinics carry out the multicenter study to evaluate the effectiveness of anti-scar treatment with Contractubex gel containing cepalin, allantoin and heparin, with its early appointment in groups of children from 12 to 18 years old and adults from 21 to 35 years old. The study included data from 216 patients. Patients of both age groups were initially divided into two: the main and control ones with an equal distribution according to the type of surgical intervention (hernia repair and appendectomy), age, gender, and anamnestic data. The dynamic observation was carried out using two rating scales - filled out by a doctor (Vancouver scale) and a patient (author's rating scale in the Scar Diary mobile application)., Results: Based on the results of the analysis of the data obtained, a high efficiency of the use of Contractubex gel at the early stages of scar formation among patients of the main group in comparison with the control was revealed. By 90 days, the treatment result according to the Vancouver scale was 0,16±0,1 points in the main group and 0,39±0,2 points in the control group. At the same time, with a dynamic scale for assessing the cicatricial process, there was a significant ( p <0.05) improvement in the main group (0,2±0,06 points) compared with the control group (0,6±0,17 points). In addition, was noticed the strong commitment to anti-scar treatment in pediatric patients., Conclusions: The work confirms the undoubted need for anti-scar treatment in the early stages of scar formation after surgical interventions, which accelerates the psychophysical rehabilitation of patients after surgery and improves the quality of life.

Nuclear domain 10 (ND10), also referred to as nuclear bodies, are discrete interchromosomal accumulations of several proteins including promyelocytic leukemia protein (PML) and Sp100. In this study, we investigated the mechanism of ND10 assembly by identifying proteins that are essential for this process using cells lines that lack individual ND10-associated proteins. We identified the adapter protein Daxx and BML, the RecQ helicase missing in Bloom syndrome, as new ND10-associated proteins. PML, but not BLM or Sp100, was found to be responsible for the proper localization of all other ND10-associated proteins since they are dispersed in PML-/- cells. Introducing PML into this cell line by transient expression or fusion with PML-producing cells recruited ND10-associated proteins into de novo formed ND10 attesting to PMLs essential nature in ND10 formation. In the absence of PML, Daxx is highly enriched in condensed chromatin. Its recruitment to ND10 from condensed chromatin requires a small ubiquitin-related modifier (SUMO-1) modification of PML and reflects the interaction between the COOH-terminal domain of Daxx and PML. The segregation of Daxx from condensed chromatin in the absence of PML to ND10 by increased accumulation of SUMO-1-modified PML suggests the presence of a variable equilibrium between these two nuclear sites. Our findings identify the basic requirements for ND10 formation and suggest a dynamic mechanism for protein recruitment to these nuclear domains controlled by the SUMO-1 modification state of PML.

The template interaction of calf thymus and human placenta DNA primases has been investigated. Using oligothymidylates, we showed that a template consisting of ten monomeric units was the critical size for interaction with the enzyme. The hydrophobic effect is likely to be a major factor determining template recognition by the DNA primase. The correlation between the template affinity with the enzyme and the octanol-water hydrophobic scale confirms this suggestion. In addition, the electrostatic interaction between the phosphate group of the template and side chains on the enzyme probably increases template affinity. Using methylated poly(dA), we found that the first nucleotide base of the primer should be more hydrophobic than the corresponding nucleotide base of the template. A model for the mechanism of action of DNA primase is suggested on the basis of data presented in this study and previous findings. According to this model, (a) DNA primase binds ten nucleotides of the template; (b) the synthesis of primer up to the formation of a decamer occurs processively and competes with template binding of the enzyme; (c) the conditions under which the nucleotides are incorporated into the RNA product change during the extension of the primer, and these changes are responsible for switching from primase to polymerase activity. The template specificity of DNA primase is likely to play an important role in the initiation and regulation of DNA replication.

Human placenta and calf thymus DNA-polymerase-alpha-primases were analyzed using native gradient-polyacrylamide-gel electrophoresis followed by overlay assays of polymerase and primase activities. The human enzyme contained three catalytically active native forms of 330, 440 and 560 kDa and the bovine enzyme five forms of 330, 440, 500, 590 and 660 kDa. Of the various DNA polymerase forms, only the largest (560 kDa for human DNA polymerase and 590 kDa and 660 kDa for bovine DNA polymerase) contained primase activity. Titration of human DNA-polymerase-alpha-primase with DNA-polymerase-free primase caused the conversion of the 440-kDa to the 560-kDa form. The data favour the idea that primase binds to DNA polymerase alpha as an oligomer of 3 primases/polymerase core. In addition, the ability of primase to utilize oligoriboadenylates containing (prA)n or pp(prA)n was investigated. The primase elongated pp(prA)2-7 up to nanoadenylates or decaadenylates, but did not add 9 or 10 mononucleotides to a preexistent primer. In contrast to pp(prA)n less than 10, (prA)n less than 10 were rather poor primers for the primase. Both pp(prA)8,9 and (prA)n greater than 10 were elongated by primase, producing characteristic multimeric oligonucleotides. The possible connection of the structure of the DNA-polymerase-alpha-primase complex with the catalytical properties of primase is discussed.

The immunoaffinity purification of human placenta DNA primase devoid of DNA polymerase alpha activity is described. Primase consists of 52 and 59 kDa polypeptides. They form a single protein of 330 kDa under native conditions. The polypeptide structure of primase is believed to be (52 + 59)3. Primase synthesizes the oligoribonucleotides 2-9 monomers long and multimeric oligoribonucleotides of a modal length of about 10 monomers. The following model of RNA primer synthesis is proposed: 1) primase, being in free state or in complex with Pol alpha, forms a protein trimer or another structure that includes several primases; 2) primase synthesizes de novo only the oligonucleotides 2-10 monomers in length; 3) the newly synthesized oligonucleotides dissociate in solution or translocate to either Pol alpha or a neighbouring primase unit to be further elongated with the next 7-10 mononucleotides.

Calf thymus DNA polymerase alpha-primase, human placenta DNA polymerase alpha-primase and human placenta DNA primase synthesized oligoriboadenylates of a preferred length of 2-10 nucleotides and multimeric oligoribonucleotides of a modal length of about 10 monomers on a poly(dT) template. The dimer and trimer were the prevalent products of the polymerization reaction. However, only the oligonucleotides from heptamers to decamers were elongated efficiently by DNA polymerase alpha.