Authors:Attila Szöllősi, László Narr, Attila G. Kovács, and Gabriella Styevkó
Kinetics of growth and product formation of G. toluenoxydans DSMZ 19350 strain were investigated using sodium-acetate as substrate and Fe3+-ions and fumarate as electron acceptor. Response surface method was adapted for evaluation of growth of bacteria. Results showed that maximum growth was detected in the case of 2.2 g/L substrate concentration. Application of higher substrate concentration (>2.5 g/L sodium acetate) significantly inhibits the bacterial growth. Luong’s model was found to be the most suitable to determine kinetic parameters (μmax = 0.033 1/h, KS = 0.205 g/L) of growth of G.toluenoxydans strain, and the growth was completely inhibited at substrate concentration higher than 3.1 g/L. In the case of product formation the Haldane model was used and kinetic parameters are μPmax = 0.123 mg/h, KPS= 0.184 g/L. Correlation between microbial growth and product formation was observed using the Luedeking–Piret empirical method. Both factors (growth and number of cells) affected significantly iron(III)-reduction, thus the product formation. These results are important and open the possibility to design a continuous MFC setting operating with G. toluenoxydans as biocatalyst.
Disposition kinetics and urinary excretion of ceftriaxone were investigated in healthy crossbred calves after its single intravenous administration (10 mg kg–1). Based on kinetic parameters, an appropriate dosage regimen of ceftriaxone in calves was calculated. The peak plasma level of ceftriaxone at 1 min was 84.0 ± 1.55 μg ml–1 which declined to 0.43 ± 0.05 μg ml–1 at 8 h. The value of elimination half-life (t1/2α), volume of distribution Vd (area) and total body clearance (ClB) were 4.39 ± 0.63 h, 1.91 ± 0.19 L kg–1 and 0.31 ± 0.01 L kg–1 h–1, respectively. Approximately 41 per cent of total administered drug was recovered in the urine within 24 h of its administration. The plasma protein binding of ceftriaxone was found to be concentration dependent with an overall mean of 38.55 per cent. The binding capacity of ceftriaxone to plasma proteins and the dissociation rate constant of protein-drug complex were 20.1 × 10–8 ± 18.4 × 10–8 mole g–1 and 1.07 × 10–6 ± 0.52 × 10–6 mole, respectively. An appropriate intravenous dosage regimen of ceftriaxone in cattle would be 12 mg kg–1 repeated at 24 h.
The aim of this study was to determine the anti-inflammatory effects of macrolides through kinetic parameters in bronchoalveolar lavage fluid (BALF) of lipopolysaccharide-induced lung injury. Rats were divided into four groups: lipopolysaccharide (LPS), LPS + tylosin, LPS + tilmicosin and LPS + tulathromycin. BALF samples were collected at sampling times. TNF, IL-1β, IL-6, IL-10 and 13,14-dihydro-15-keto-prostaglandin F2α (PGM) and C-reactive protein (CRP) were analysed. Area under the curve (AUC) and maximum plasma concentration (Cmax) values of inflammatory mediators were determined by a pharmacokinetic computer programme. When inflammatory mediator concentrations were compared between the LPS group and other groups for each sampling time, the three macrolides had no pronounced depressor effect on cytokine levels, but they depressed PGM and CRP levels. In addition, tylosin and tilmicosin decreased the AUC0-24 level of TNF, while tilmicosin decreased the AUC0-24 level of IL-10. Tylosin and tulathromycin decreased the AUC0-24 of PGM, and all three macrolides decreased the AUC0-24 of CRP. Especially tylosin and tulathromycin may have more expressed anti-inflammatory effects than tilmicosin, via depressing the production of inflammatory mediators in the lung. The AUC may be used for determining the effects of drugs on inflammation. In this study, the antiinflammatory effects of these antibiotics were evaluated with kinetic parameters as a new and different approach.
Kanwar, S. S., Verma, H. K., Kumar, Y., Chimni, S. S., Chauhan, G. S.: Effect of solvents and kineticparameters on synthesis of ethyl propionate by
-MBAm)-matrix immobilized lipase of
, J. L., Carta, G., Mrani, A., Kadiri, T., Belarbi, Y., Mir, A.: Esterification of fatty acids using nylon-immobilized lipase in
-hexane: Kineticparameters and chain-length effects. J Biotechnol
, 209–216 (2002
Authors:Andreja Prevendar Crnić, D. Sakar, Jelena Pompe-Gotal, Z. Biđin, Ivana Lojkić, and S. Čajavec
Cinti, D. L., Moldeus, P. and Schenkman, J. B. (1972): Kineticparameters of drug-metabolizing enzymes in Ca 2+ -sedimented microsomes from rat liver. Biochem. Pharmacol. 21 , 3249-3256.
Kineticparameters of drug