Experimental evaluation of new chitin-chitosan graft for duraplasty.

Natural materials such as collagen and alginate have promising applications as dural graft substitutes. These materials are able to restore the dural defect and create optimal conditions for the development of connective tissue at the site of injury. A promising material for biomedical applications is chitosan-a linear polysaccharide obtained by the deacetylation of chitin. It has been found to be nontoxic, biodegradable, biofunctional and biocompatible in addition to having antimicrobial characteristics. In this study we designed new chitin-chitosan substitutes for dura mater closure and evaluated their effectiveness and safety. Chitosan films were produced from 3 % of chitosan (molar mass-200, 500 or 700 kDa, deacetylation rate 80-90%) with addition of 20% of chitin. Antimicrobial effictively and cell viability were analysed for the different molar masses of chitosan. The film containing chitosan of molar mass 200 kDa, had the best antimicrobial and biological activity and was successfully used for experimental duraplasty in an in vivo model. In conclusion the chitin-chitosan membrane designed here met the requirements for a dura matter graft exhibiting the ability to support cell growth, inhibit microbial growth and biodegradade at an appropriate rate. Therefore this is a promising material for clinical duroplasty.

[DISTRIBUTION OF GENOTYPES OF C825T POLYMORPHISM ß3-SUBUNIT G-PROTEIN GENE IN PATIENTS WITH ARTERIAL HYPERTENSION ACCORDING THE DEGREE OF OBESITY].

Arterial hypertension (AH) and obesity - risk factors for cardiovascular diseases and their complications, leading to high morbidity and mortality. These nosologies notedly linked, because have common etiological factors, pathophysiological mechanisms and genetic determination. The aim this research was to analyze the distribution of genotypes of the C825T polymorphism of ß3-subunit G-protein gene (GNB3) according the degree of obesity and to assess the risk of obesity in patients with AH. Patients were divided into three groups according the degree of obesity. We used clinical, anthropometric, instrumental, molecular-genetic and statistical methods. The significance of differences of alleles and genotypes frequency was determined by test χ². For comparing the groups used nonparametric Mann-Whitney and Kruskal-Wallis tests. A value of p<0.05 was considered significant. Our research showed high frequency of T allele carriers and C/T genotype among patients with hypertension and obesity (χ² = 27,976, p <0.001). In our study we observed the absence of statistically significantly difference (p = 0.677) of distribution of genotypes and alleles in patients with AH according the degree of obesity. The risk of obesity in T allele carriers was in 2.2 times higher than in C allele carriers in patients with AH. In summary, our study showed association of C825T polymorphism of the GNB3 with obesity, but did not prove the association this with the degree of obesity i patients with AH.