Comparative Morphological Characteristics of the Results of Implantation of Decellularized and Recellularized Porcine Skin Scaffolds.

The tissue reaction of pig skin to implantation of decellularized and recellularized dermal matrices on a formed wound defect was evaluated by histological methods on days 2, 5, 8, 16, and 20 after surgery. Differences in tissue response to different matrices were identified. In experimental wounds coated with decellularized dermal matrices, we observed the formation of a scar tissue, which required autodermoplasty on day 12 of the experiment. In wounds coated with recellularized dermal matrices, all layers of the skin completely recovered by day 20 after surgery with the formation of full dermal and epidermal layers. Our findings suggest that reparative morphological changes in the wound depend on the presence of fibroblasts in the implanted dermal matrix.

Modification of Rat Lung Decellularization Protocol Based on Dynamic Conductometry of Working Solution.

We modified the protocol of obtaining of biological scaffolds of rat lungs based on dynamic recording of specific resistivity of working detergent solution (conductometry) during perfusion decellularization. Termination of sodium deoxycholate exposure after attaining ionic equilibrium plateau did not impair the quality of decellularization and preserved structural matrix components, which was confirmed by morphological analysis and quantitative assay of residual DNA.

[Automatic morphometric analysis as a method for determining the level of extracellular matrix components and for quantifying nuclear antigens]. / Avtomatizirovannyi morfometricheskii analiz kak metod opredeleniia soderzhaniia komponentov vnekletochnogo matriksa i kolichestvennoi otsenki iadernykh antigenov.

Automated image analysis methods are highly important for biotechnology research. The authors developed and tested a program for the morphometric analysis of photomicrographs of the sections processed using the standard immunohistochemical examination protocols. The color deconvolution method used in the algorithm was proven to be effective in mapping the distribution of DAB chromogen in the sample containing multiple dyes. The experiment demonstrated that the level of extracellular matrix proteins could be comparatively quantified in different groups of samples. The effective methods for the quantitative analysis of the Ki-67 labelling index were also tested using the same algorithms. The developed program was published under free GPL 3.0.

[Experimental development and rationale for a renal decellularization protocol with subsequent comprehensive assessment of the biological scaffold].

Chronic renal failure (CRF) is one of the most challenging problems of contemporary medicine. Patients with chronic renal failure usually need renal replacement therapy as either hemodialysis, peritoneal dialysis or a kidney transplant. The latter is the most promising option for end-stage kidney disease. However, the shortage of donor organs, the complexity of their delivery, the difficulty in finding an immunologically compatible donor and the need for lifelong immunosuppression triggered advances in modern tissue engineering. In this field, the primary priority is focused on developing bioengineered scaffolds with subsequent recellularization with autologous cells. Using such constructs would allow for solving both ethical and immunological problems of transplantation. The aim of this pilot study was to develop a new method of renal decellularization using small laboratory animals. MATERIALS AND METHODS: The study investigated the morphological structure of the obtained decellularized matrix and quantitatively tested DNA residues in the resulting scaffold. We proposed a new biophysical method for assessing the matrix quality using the EPR spectroscopy and conducted experiments on the matrix recellularization with mesenchymal multipotent stem cells to estimate cytotoxicity, cell viability and metabolic activity. RESULTS: The obtained decellularized renal matrix retained the native tissue architecture after a complete removal of the cell material, had no cytotoxic properties and supported cell adhesion and proliferation. CONCLUSION: All the above suggests that the proposed decellularization protocol is a promising method to produce tissue-engineered kidney constructs with possible clinical application in the foreseeable future.

Evaluation of the influence of decellularization on the changes in biomechanical properties of primate lungs.

The effect of decellularization on the biomechanical properties of macaque lungs was studied. The quality of the biological scaffold was additionally assessed by morphological methods, and the contents of extracellular matrix (ECM) fibers were determined both qualitatively and quantitatively. Histological analysis revealed no damage of structural integrity of ECM components, but the scaffold elasticity significantly decreased, which was confirmed by the changes in the hysteresis loop without a concomitant decrease in peak loads, with the mechanical strength of the samples being retained. These changes require taking additional measures to prevent a decrease in the effective lung volume.

[Modern diagnostic and management aspects of citrate therapy for uric acid nephrolithiasis].

INTRODUCTION: Iso-aciduria - long-term existence of urine pH within a narrow range (pH <0.8-1.2 units.) - activates certain enzymes for which these pH levels are favorable. Then, this activation induces precipitation of crystals corresponding to these enzymes. OBJECTIVE: To enable citrate therapy without a risk of altering the stone chemical composition and to identify indicators reflecting the degree of metabolic disorders in patients with uric acid nephrolithiasis. MATERIAL AND METHODS: Citrate therapy was provided with a mixture comprising "Potassium citrate monohydrate" and "Tri-sodium citrate di-hydrate" in a ratio of 2: 1. The study group included 64 patients, who had ultrasound-detected calyx stones and hyperechoic inclusions from 2 to 4 mm without acoustic shadow, located in the papillary region of the renal pyramids. Statistical analysis was performed by cross tabulations (pairing). RESULTS: The results of the statistical analysis have proven the legitimacy and feasibility of the proposed method of classifying patients into homogeneous groups according to the disease severity. CONCLUSION: Long-term citrate therapy should be carried out in such a way as to achieve maximum range of urine pH (from 5.4 to 7.8 units), which will allow to avoid deposition of other crystals upon the existing stone and identify indicators reflecting the degree of metabolic disorders in patients with uric acid nephrolithiasis. CONCLUSION: Long-term citrate therapy should be carried out in such a way as to achieve maximum range of urine pH (from 5.4 to 7.8 units), thus avoiding deposition of other crystals upon the existing stone.

[Positional changes of the magistral blood flow of the left kidney in men with varicocele and infertility].

This paper proves the correlation between characteristics of blood flow rate in the renal veins and resistance indices of the renal arteries. As a result of polypositional assessment of venous blood flow, it was found that the violations of magistral venous blood flow in the left kidney can affect the formation and progression of varicocele, and the severity of disorders of spermatogenesis. The necessity of assessment of testicular veins and the pressure in left renal vein not only in clin- and orthostasis or Valsalva maneuver, but in the six static positions is discussed; this can allow to register the violations of magistral renal blood flow at the early stages important for fertility disorders, improve the efficiency of diagnosis and treatment of patients with varicocele.

[Polymorphism of the HLA-DRB1 04 gene in inhabitants of Tuva]. / Polimorfizm gena HLA-DRB1 04 u zhitelei Tuvy.

Data on the HLA-DRB1 04 gene typing among Tuvinians from Kyzyl are presented. Experiments were conducted by using the hybridization of allele-specific oligonucleotides with the amplified fragments of high molecular-weight DNA and reverse hybridization. The HLA-DRB1 0401 allele was most frequent among DR4-positive individuals. The HLA-DRB1 0405 and HLA-DRB1 0403 alleles were found at somewhat lower frequencies. In one individual, the rare HLA-DRB1 0410 subtype differing from HLA-DRB1 0405 subtype by the substitution of glycine for valine in codon 86 was detected.