The role of alkaloids in cigarette smoke was investigated in the cumulus expansion of oocyte-cumulus complexes (OCC) isolated from large antral porcine follicles. Suppression of the cumulus expansion stimulated by FSH was observed in the presence of different concentration of cadmium, anabasine and nicotine but not its metabolite cotinine. There were comparable inhibitory effects of cadmium and nicotine on the synthesis and accumulation of hyaluronic acid in the cell/matrix compartment of OCC. The inhibitory effect of tested compounds on the cumulus expansion was accompanied by decreased progesterone synthesis by cumulus cells during 42 h incubation of OCC with FSH. The results suggest that cigarette smoking may affect intrafollicular processes, which are responsible for normal ovulation and fertilization., S. Vršanská, E. Nagyová, A. Mlynarčíková, M. Ficková, J. Kolena., and Obsahuje bibliografii
a1_Mechanical properties of scaffolds seeded with mesenchymal stem cells used for cartilage repair seem to be one of the critical factors in possible joint resurfacing. In this paper, the effect of adding hyaluronic acid, hydroxyapatite nanoparticles or chitosan nanofibers into the cross-linked collagen I on the mechanical response of the lyophilized porous scaffold has been investigated in the dry state at 37 oC under tensile loading. Statistical significance of the results was evaluated using ANOVA analysis. The results showed that the addition of hyaluronic acid significantly (p<<0.05) reduced the tensile elastic modulus and enhanced the strength and deformation to failure of the modified cross-linked collagen I under the used test conditions. On the other hand, addition of hydroxyapatite nanoparticles and chitosan nanofibers, respectively, increased the elastic modulus of the modified collagen ten-fold and four-fold, respectively. Hydroxyapatite caused significant reduction in the ultimate deformation at break while chitosan nanofibers enhanced the ultimate deformation under tensile loading substantially (p<<0.05). The ultimate tensile deformation was significantly (p<<0.05) increased by addition of the chitosan nanofibers. The enhanced elastic modulus of the scaffold was translated into enhanced resistance of the porous scaffolds against mechanical load compared to scaffolds based on cross-linked neat collagen or collagen with hyaluronic acid with similar porosity. It can be concluded that enhancing the rigidity of the compact scaffold material by adding rigid chitosan nanofibers can improve the resistance of the porous scaffolds against compressive loading, which can provide more structural protection to the seeded mesenchymal stem cells when the construct is implanted into a lesion., a2_Moreover, scaffolds with chitosan nanofibers seemed to enhance cell growth compared to the neat collagen I when tested in vitro as well as the scaffold stability, extending its resorption to more than 10 weeks., J. Jančář, A. Slovíková, E. Amler, P. Krupa, H. Kecová, L. Plánka, P. Gál, A. Nečas., and Obsahuje bibliografii