Differences in resistance to reinfection with low and high inocula of <i>Trypanosoma cruzi</i> in chagasic mice treated with nifurtimox and relation to immune response

Reinfection of chronic chagasic mice after treatment with nifurtimox resulted in different outcomes according to the number of parasites used for inoculation. Nifurtimox-treated chagasic animals injected with 2,500 trypomastigotes developed higher parasitemia and increased mortality compared with nontreated chagasic mice. When reinfection was done with 25 trypomastigotes, treated and nontreated animals showed similar parasitemias and mortalities, which were significantly higher in nonchagasic controls infected for the first time. Immunological studies showed that treatment with nifurtimox led to a decrease in anti-Trypanosoma cruzi antibodies engaged in parasite destruction, inducing either complement-dependent lysis or antibodydependent cytotoxicity, but no difference in anti-T. cruzi cell-mediated immunity was found between treated and nontreated chagasic animals. It is concluded that treatment with nifurtimox leads to a loss of resistance to reinfection with a large number of trypanosomes, which is maintained with challenge with a few parasites, and that these two thresholds of premunition are probably associated with humoral and cell-mediated anti-T. cruzi immune responses, respectively.Facultad de Ciencias Médica

Rol de la HSP27 y HSP70 en la progresión del cáncer de pulmón humano

El desarrollo de nuevos marcadores tumorales, se hace cada vez más necesario para identificar pacientes portadores de cáncer de pulmón con alta posibilidad de recurrencia y baja sobrevida. Sin embargo, hasta la fecha y pese a todos los esfuerzos, ningún marcador ha sido totalmente satisfactorio como factor predictivo. En este sentido, la familia de las Hsp (proteínas de shock térmico) constituye un grupo de chaperonas moleculares que se generan para mantener la homeostasis y proteger a las células normales ante una injuria.Facultad de Ciencias Médica

Rol de la HSP27 y HSP70 en la progresión del cáncer de pulmón humano

El desarrollo de nuevos marcadores tumorales, se hace cada vez más necesario para identificar pacientes portadores de cáncer de pulmón con alta posibilidad de recurrencia y baja sobrevida. Sin embargo, hasta la fecha y pese a todos los esfuerzos, ningún marcador ha sido totalmente satisfactorio como factor predictivo. En este sentido, la familia de las Hsp (proteínas de shock térmico) constituye un grupo de chaperonas moleculares que se generan para mantener la homeostasis y proteger a las células normales ante una injuria.Facultad de Ciencias Médica

Differences in resistance to reinfection with low and high inocula of <i>Trypanosoma cruzi</i> in chagasic mice treated with nifurtimox and relation to immune response

Reinfection of chronic chagasic mice after treatment with nifurtimox resulted in different outcomes according to the number of parasites used for inoculation. Nifurtimox-treated chagasic animals injected with 2,500 trypomastigotes developed higher parasitemia and increased mortality compared with nontreated chagasic mice. When reinfection was done with 25 trypomastigotes, treated and nontreated animals showed similar parasitemias and mortalities, which were significantly higher in nonchagasic controls infected for the first time. Immunological studies showed that treatment with nifurtimox led to a decrease in anti-Trypanosoma cruzi antibodies engaged in parasite destruction, inducing either complement-dependent lysis or antibodydependent cytotoxicity, but no difference in anti-T. cruzi cell-mediated immunity was found between treated and nontreated chagasic animals. It is concluded that treatment with nifurtimox leads to a loss of resistance to reinfection with a large number of trypanosomes, which is maintained with challenge with a few parasites, and that these two thresholds of premunition are probably associated with humoral and cell-mediated anti-T. cruzi immune responses, respectively.Facultad de Ciencias Médica