RESUMO
The methods accepted to determine antimicrobial drug susceptibility of mycobacteria are based on the determination of the microorganisms' growth on solid or liquid medium containing a specified concentration of a single drug.
RESUMO
In the present work a rapid method to determine the susceptibility of Mycobacterium tuberculosis to isoniazid and streptomycin by determining levels of mycolic acids by high-performance liquid chromatography (HPLC) was developed. Mycobacterial growth kinetics in the presence and absence of antituberculosis drugs was characterized by evaluating the total area corresponding to mycolic acid peaks (TAMA). Results show a linear relationship between the logarithm of CFU per milliliter and TAMA and show that it is possible to detect growth inhibition of M. tuberculosis in the presence of isoniazid or streptomycin by using HPLC in 3 and 4 days, respectively.
Assuntos
Antibióticos Antituberculose/farmacologia , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Ácidos Micólicos/análise , Cromatografia Líquida de Alta PressãoRESUMO
T-514 is a toxic substance of Karwinskia humboldtiana which has been described as a possible anticancer agent. An animal model (New Zeland white rabbit) was selected for pharmacokinetic studies that would allow the performance of surgical techniques to catheterize central vessels in order to obtain blood samples at short time intervals. A nonlinear regression analysis method was used to fit the plasmatic concentration data to a multiexponential mathematical function; a computer program based on Marquant's iterating algorithm was used to fit the experimental curves. In the present work we show the advantage of introducing two catheters of different diameters in the jugular vein using modifications of the Seldinger and Braunüle techniques: a catheter of small diameter (18 G) is used to introduce the drug and a larger one (16 G) to sample at different times. The larger diameter catheter facilitates a rapid sampling of blood (two mL/s) which is essential to determine the initial phase of the distribution process (alpha phase). The behavior of T-514 corresponded to a two-compartment model with a biexponential equation C = 0.35 e-0.13(t-2) + 0.17 e-0.03(t-2).