Biomedical subjects

J Labuda

Publications and source records attributed to J Labuda.

5 recordsLinked to original sources

PubMed2001

Cyclodextrins as electrode modifiers.

Complexation abilities and analytical applications of working electrodes with attached cyclodextrins (CDs) are reviewed. For the immobilization of CDs, their adsorption and formation of self-assembled monolayers, preparation of polymer films, as well as incorporation within plasticized membranes and composites such as carbon paste and gels are considered. Some electrochemical investigations of the CD interactions in solution are also reported with respect to their use at CD modified electrodes.

Adsorption↗

PubMed2000

Modified screen-printed electrodes for the investigation of the interaction of non-electroactive quinazoline derivatives with DNA.

Five morpholino-quinazoline derivatives have been investigated voltammetrically using a competition with the tris(o-phenanthroline) cobalt(III) redox marker for the accumulation at dsDNA modified screen-printed electrodes. An association of quinazolines with DNA was observed at the modified electrodes polarized by the negative potential of -0.4 V vs. Ag/AgCl. This was confirmed by a potentiometric stripping analysis based on the DNA guanine signal. Calibration curves for quinazolines within a concentration range of micromol/L were obtained with DP voltammetry using 5 x 10(-7) mol/L Co(phen)3(3+) marker. The quinazolines exhibit no effect on the DNA complex with the fluorescent thiazole orange derivative TO-PRO-3. The role of the accumulation potential in the association interaction with DNA is discussed.

Calibration↗

PubMed1998

Macrocyclic Cu(II)tetraanhydroaminobenzaldehyde complex--antiproliferative activity in vitro and in vivo.

The macrocyclic Cu(II)-tetraanhydroaminobenzaldehyde complex Cu(TAAB)C12 induces various cytotoxic effects in the dependence on a cell line, concentration and time of exposition. The highest complex concentration of 914 nmol/l induces degeneration of certain part of the HeLa cells population after 24 hours of cultivation. The concentration of 183 nmol/l causes a delayed cytotoxic effect on HeLa and HepG2 cells. After 24 hours of culturing 15.4-28.4% of cell population proliferated but after 48 and 72 hours 2.0-42.3% of the cell population degenerated. The cytotoxic effect on V79 cells is directly dependent on the actual concentration and time of the complex influence. The cytotoxic concentrations of Cu(TAAB)Cl2 induce an integrity damage of cytoplasmatic membrane and two phase unbalanced growth. Cu(TAAB)Cl2 possesses an antileukemic activity which at the dose of 10 mg/kg of body weight is not accompanied by side toxic effects on mice.

Animals↗

PubMed1997

Antimicrobial effects of the macrocyclic Cu(II)-tetraanhydroaminobenzaldehyde complex.

The Cu(II)-tetraaza macrocyclic complex exhibited antimicrobial effects on bacteria, yeasts and filamentous fungi. The highest antibacterial activity was found with B. subtilis and S. aureus, the respective IC50 values being 18 and 80 micrograms/L and the MIC values 50 and 1000 micrograms/L. A concentration of 1 mg/L exerted a bacteriocide effect on S. aureus. The MIC value for B. subtilis was 250 times lower and for P. aeruginosa 10 times lower than the corresponding values for ampicillin. The Cu-complex was inactive against all tested yeasts. The strongest antifungal effect was manifested for R. nigricans, with an IC50 value under 0.1 mg/L, whereas in A. alternata the IC50 was 13.5 mg/L.

Anti-Bacterial Agents↗

PubMed1995

Superoxide dismutase mimetic activity of macrocyclic Cu(II)-tetraanhydroaminobenzaldehyde (TAAB) complex.

The superoxide dismutase mimetic activity of a copper(II) complex with the tetraazamacrocyclic ligand TAAB has been investigated using the xanthin-xanthine oxidase system for generation of superoxide. The complex exhibits 50% inhibition of the 3-(4-iodophenyl)-2-(4-nitrophenyl)-5-phenyltetrazolium chloride (INT) reduction at the concentration of 0.144 mumol.l-1 (pH 7.8, 25 degrees C). The activity survives in the presence of chelators including EDTA and serum albumin. The enzymatic activity of the complex represents about 3% of that of intact Cu2Zn2SOD.

Copper↗