National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Combination of cobalt bis(dicarbollide) amino derivative and antibiotic effect on growth of staphylococcus epidermidis
Lokočová, K. ; Vaňková, E. ; Šícha, Václav ; Masák, J.
Nosocomial infections are often caused by bacteria from the Staphylococcus genus. The clinically relevant representatives of this species are Staphylococcus epidermidis and Staphylococcus aureus which grow predominantly as surface-attached stable communities known as biofilms. Cells in these biofilms are often highly resistant to antibiotics. Therefore, new antimicrobial or antibiofilm substances are still being developed. In this study, we investigated the influence of cobalt bis(dicarbollide) or its amino derivatives, and antibiotics (erythromycin, tetracycline)-alone and in combination-to determine the antimicrobial activity and the inhibition of biofilm formation against three type strains of S. epidermidis. We used a microcultivation device to determine the minimum inhibitory concentrations and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay to determine the metabolic activity of the cells in biofilms. We observed the synergistic effect of cobalt bis(dicarbollide) and its amino derivatives with both the antibiotics on both the planktonic and biofilm cells.
Substituted metallacarboranes and carboranes with potentially interesting biological activity
Šícha, Václav
The research in this Ph.D. thesis deals with the preparation of new substitutional derivatives of cobaltabisdicarbollide and icosahedral carboranes designed primarily to search for new drugs to inhibit the HIV-1 protease enzyme, which causes AIDS. The use of borane clusters overcomes the shortcomings of existing organic inhibitors. After synthesis of the compounds reported here, they were passed to biochemists who measured the inhibition kinetics of these substances on an isolated enzyme HIV-1 protease (IC50), and performed similar tests on HIV-1 infected cell cultures (EC50). For each compound, the concentration which caused an inhibition of enzyme activity (substrate cleavage) of 50 % of the concentrations of, IC50 (in vitro) and EC50 (in vivo) were included into boron compounds library. Additionally included was the specific mechanism by which the substances were able to selectively inhibit the enzyme. These findings are a key to possible future drug substructure determination. The author of this thesis synthesized and characterized a series of fourteen new compounds containing a motif of two units of cobalt bisdicarbollide connected with a flexible organic chain via a functional group embedded in the center of the molecule. Twelve new B-N derivatives offering cobalta bisdicarbollide nitrile,...
Antimicrobial activity of cobalt bis(dicarbollide) aminoderivatives
Kvasničková, E. ; Masák, J. ; Šícha, Václav
We carried out experiments focused on the determination of the antimicrobial acitivity of selected representatives of cobalt bis{dicarbollide) aminoderivates. lt was proved, that studied yeast strain C. parapsilosis DBM 2165 is not sensitive to the cobalt bis{dicarbollide) or its aminoderivatives. Gram-negative bacteria P. aeruginosa B-59188 is weakly susceptive to cobalt bis(dicarbollide), but no significant inhibition of growth by cobalt bis(dicarbollide) aminoderivatives was observed. The highest effect on inhibition of microbial growth was confirmed in the case of gram-positive bacteria 5. aureus. This observation demonstrates the real possibility of using these substances in the treatment of infection caused by gram-positive bacterial strains.

See also: similar author names
1 Šicha, Václav
2 Šícha, Vojtěch
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