ORCID Profile
0000-0001-5484-4573
Current Organisation
Universidad de Chile Facultad de Medicina
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Publisher: Frontiers Media SA
Date: 06-12-2021
DOI: 10.3389/FPHAR.2021.674117
Abstract: Cyclosporine (CsA) and tacrolimus (TAC) are immunosuppressant drugs characterized by a narrow therapeutic range and high pharmacokinetic variability. The effect of polymorphisms in genes related to the metabolism and transport of these drugs, namely CYP3A4 , CYP3A5 , MDR1 and POR genes, has been evaluated in erse populations. However, the impact of these polymorphisms on drug disposition is not well established in Latin American populations. Using TaqMan ® probes, we determined the allelic frequency of seven variants in CYP3A4 , CYP3A5 , MDR1 and POR in 139 Chilean renal transplant recipients, of which 89 were treated with CsA and 50 with TAC. We tested associations between variants and trough and/or 2-hour concentrations, normalized by dose (C 0 /D and C 2 /D) at specific time points post-transplant. We found that CYP3A5*3/*3 carriers required lower doses of TAC. In TAC treated patients, most CYP3A5*3/*3 carriers presented higher C 0 /D and a high proportion of patients with C 0 levels outside the therapeutic range relative to other genotypes. These results reinforce the value of considering CYP3A5 genotypes alongside therapeutic drug monitoring for TAC treated Chilean kidney recipients.
Publisher: Wiley
Date: 06-2009
DOI: 10.1111/J.1558-5646.2009.00660.X
Abstract: Models of host-parasite coevolution predict pronounced genetic dynamics if resistance and infectivity are genotype-specific or associated with costs, and if selection is fueled by sufficient genetic variation. We addressed these assumptions in the black bean aphid, Aphis fabae, and its parasitoid Lysiphlebus fabarum. Parasitoid genotypes differed in infectivity and host clones exhibited huge variation for susceptibility. This variation occurred at two levels. Clones harboring Hamiltonella defensa, a bacterial endosymbiont known to protect pea aphids against parasitoids, enjoyed greatly reduced susceptibility, yet clones without H. defensa also exhibited significant variation. Although there was no evidence for genotype-specificity in the H. defensa-free clones' interaction with parasitoids, we found such evidence in clones containing the bacterium. This suggests that parasitoid genotypes differ in their ability to overcome H. defensa, resulting in an apparent host x parasitoid genotype interaction that may in fact be due to an underlying symbiont x parasitoid genotype interaction. Aphid susceptibility to parasitoids correlated negatively with fecundity and rate of increase, due to H. defensa-bearing clones being more fecund on average. Hence, possessing symbionts may also be favorable in the absence of parasitoids, which raises the question why H. defensa does not go to fixation and highlights the need to develop new models to understand the dynamics of endosymbiont-mediated coevolution.
No related grants have been discovered for Luis E. Castañeda.