The Best Material from the VII Congress of Russian Biophysicists.

The purpose of this Special Issue is to demonstrate the current state of research in the field of biophysics in the Russian Federation [...].

Medium viscosity influence on the open states genesis in a DNA molecule.

The studies were carried out by the mathematical modeling of DNA mechanical deformations. Numerical calculations done for the interferon alpha 17 gene, which consists of 980 base pairs. It has been established that the genesis and dynamics of open states in the DNA molecule depends on the magnitude of the external influence (torque) and on the viscosity of the environment. In addition, it is shown that the dynamics of open states zones can have a jump-like character with a small change in the magnitude of the torque. When torque is applied to all 980 base pairs of the gene, the following effect is observed: an increase in the viscosity of the medium leads to an increase in the value of the torque necessary for the occurrence of OS and DNA unwinding, i.e. viscosity plays an important stabilizing role in DNA dynamics. Under the influence of a localized torque on different (by the content of A-T and G-C pairs and location) regions of the interferon alpha 17 gene, it was found that the magnitude of the external torque necessary for the occurrence of open states at all calculated values of viscosity depends on the nucleotide composition. The dependence of the torque magnitude required for the open states occurrence on viscosity is observed when the torque is applied to areas close to the gene boundaries. At the same time, the significance of the end effect, which weakens DNA, decreased with increasing viscosity of the medium.Communicated by Ramaswamy H. Sarma.

Evaluation of effectiveness of a new treatment method for healing infected wounds: an animal model.

OBJECTIVE: To evaluate the effectiveness of a new treatment method in healing superficial infected wounds compared with surgical debridement with chlorhexidine solution. METHOD: In this animal model, two wounds were created on the back of 10 male adult rabbits. Wounds treated by Method 1 were debrided using 0.02% chlorhexidine aqueous solution and an antibiotic topical ointment. Wounds treated by Method 2 wounds were treated using a newly developed device which enabled visual monitoring of the wound as it was treated with various pharmacological solutions (including antiseptic, antiseptic oxidant and an osmotically active agent) specifically formulated for each wound healing stage. Wound area size (using digital planimetry) and time taken to clean the wound were recorded, and biopsies were taken, at the beginning of the study and at various timepoints throughout. RESULT: It was observed that both wound cleaning and wound healing were accelerated by treatment with method 2 compared with method 1 (by 43.8% and 36.7%, respectively). There were also a significantly smaller number of complications in these wounds [p=0.0044] due to the positive ratios of neutrophils and fibroblasts in the wound cavities (from the third to the fourteenth day after wound modelling). CONCLUSION: Wounds treated with the new device in method 2 had a shorter wound healing time than wounds treated with a traditional method. The automated influx-outflow of solutions removed any fragments of necrotic tissue from the wound surface. Wounds were able to be monitored without the need to remove dressings. The transparent, airtight film, which allowed for wound monitoring without the need to remove dressings, meant that suturing was not required. This resulted in no complications in the wounds treated by this new method.

Gender Difference Response of Male and Female Immunodeficiency Rats Treated with Tissue-specific Biomolecules.

BACKGROUND: The modern immunology is targeted to the detailed study of various immunopathological conditions at the molecular and cellular level, development of new methods for the prevention, diagnostics and treatment of contagious and non-contagious diseases of humans and animals. METHODS: In the present work we took the rats with model of cyclophosphamide-induced immunodeficiency and studied the features of gender impact of the complex extract of immunocompetent organs (thymus, spleen and mesenteric lymph nodes) Sus scrofa and its separate fraction with molecular weight less than 30 kDa administered to male and female rats. RESULTS: The impact of gender differences and tissue-specific biomolecules (30 kDa fraction) on hematological parameters (leukocytes, erythrocytes, platelets), functional activity of immune system (IL-2, IL-4, IL-6, complement system, IgG, IgM), biochemical parameters of hepatocytes functioning (activity of ALP and LDG), carbohydrate metabolism (glucose) and lipid metabolism (triglycerides). CONCLUSION: Decrease of ALP activity is caused by inhibition of bile formation in a liver after introduction of cytostatic agent, and in contrast to complex extract, the administration of fraction 30 kDa allows improving bile production in male rats.

Orthotopic transplantation of a tissue engineered diaphragm in rats.

The currently available surgical options to repair the diaphragm are associated with significant risks of defect recurrence, lack of growth potential and restored functionality. A tissue engineered diaphragm has the potential to improve surgical outcomes for patients with congenital or acquired disorders. Here we show that decellularized diaphragmatic tissue reseeded with bone marrow mesenchymal stromal cells (BM-MSCs) facilitates in situ regeneration of functional tissue. A novel bioreactor, using simultaneous perfusion and agitation, was used to rapidly decellularize rat diaphragms. The scaffolds retained architecture and mechanical properties and supported cell adhesion, proliferation and differentiation. Biocompatibility was further confirmed in vitro and in vivo. We replaced 80% of the left hemidiaphragm with reseeded diaphragmatic scaffolds. After three weeks, transplanted animals gained 32% weight, showed myography, spirometry parameters, and histological evaluations similar to native rats. In conclusion, our study suggested that reseeded decellularized diaphragmatic tissue appears to be a promising option for patients in need of diaphragmatic reconstruction.