ABSTRACT
Widespread antimalarial resistance has been a barrier to malaria elimination efforts in Sri Lanka. Analysis of genetic markers in historic parasites may uncover trends in the spread of resistance. We examined the frequency of Plasmodium falciparum chloroquine transporter (pfcrt; codons 72-76) haplotypes in Sri Lanka in 1996-1998 and 2004-2006 using a high-resolution melting assay. Among 59 samples from 1996 to 1998, we detected the SVMNT (86%), CVMNK (10%), and CVIET (2%) haplotypes, with a positive trend in SVMNT and a negative trend in CVMNK frequency (P = 0.004) over time. Among 24 samples from 2004 to 2006, we observed only the SVMNT haplotype. This finding indicates selection for the SVMNT haplotype over time and its possible fixation in the population.
Subject(s)
Antimalarials/pharmacology , Chloroquine/pharmacology , Malaria, Falciparum/parasitology , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Plasmodium falciparum/genetics , Protozoan Proteins/genetics , Protozoan Proteins/metabolism , Animals , Drug Resistance/genetics , Haplotypes , Humans , Malaria, Falciparum/epidemiology , Plasmodium falciparum/drug effects , Sri Lanka/epidemiology , Time FactorsABSTRACT
Uterine leiomyomas (also known as uterine fibroids) are the most common benign tumors of female reproductive tract and are the single most common indication for hysterectomies. Despite their high prevalence, the exact pathogenesis of these benign tumors is still unknown. One possible mechanism for leiomyoma formation is dysregulation of mesenchymal stem cell activity. Mesenchymal stem cells have been identified in both human and murine uteri and cancer stem cells have been identified in female reproductive malignancies. We compared stem/progenitor cell characteristics in both normal myometrium and the corresponding leiomyoma of patient's undergoing hysterectomies. We found that leiomyoma cells form fewer mesenchymal stem cell colonies and exhibit less Hoechst dye-excluding side population (SP) activity, which is a function associated with progenitor cells in other tissues, than cells isolated from normal myometrium. Whereas in normal myometrium, we observed heterogeneous expression of CD90, a cell surface marker associated the with differentiation potential of uterine fibroblasts, in leiomyomas, we observed homogenous expression of CD90, suggesting leiomyoma cells are more terminally differentiated. Furthermore, we found that while leiomyoma cells could only produce CD90 expressing cells, both CD90+ and CD90- myometrial cells could reestablish their original heterogeneous CD90 profile when expanded in vitro. These results suggest that normal myometrium contains cells with stem/progenitor cell activities that are absent in leiomyomas.
