Luis Eduardo Ramirez Giraldo

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Trypanosoma cruzi (Tc) diversity is determined by different biological, genetic, and biochemical markers and has been grouped into six discrete typing units (DTUs) or taxonomic groups (TcI–TcVI). This variability, coupled with natural reinfection or the hosts' immunosuppression, may play an important role in the pathogenesis of Chagas disease. Therefore, we(More)
In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF) sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum(More)
Polymorphisms in Plasmodium falciparum cg2 and pfcrt genes and their association with chloroquine resistance in vitro in Colombian parasites were evaluated in this study. Association of chloroquine resistance with resistance to other antimalarial drugs in vitro was also examined. Polymerase chain reactions (PCR) for kappa and omega cg2 regions and nested(More)
Several point mutations in the dihydrofolate reductase (DHFR) gene of Plasmodium falciparum have been correlated with in vitro anti-folate drug resistance of laboratory and field isolates. Furthermore, two different point mutations that generate amino acid substitutions at the same position of the enzyme have been observed in all the isolates studied to(More)
Several highly antigenic proteins containing tandem repeats rich in glutamic acid residues have been described in Plasmodium falciparum. However, relatively little information is available about analogous genes in rodent parasites. This report describes a 4.2-kb genomic DNA fragment from P. chabaudi with a deduced amino acid sequence that is predominantly(More)
Although chloroquine (CQ) resistance was first reported in Colombia in 1961 and sulfadoxine-pyrimethamine (SP) resistance in 1981, the frequency of treatment failures to these drugs in Colombia is unclear. A modified World Health Organization 14-day in vivo drug efficacy test for uncomplicated Plasmodium falciparum malaria in areas with intense malaria(More)
Sulfadoxine/pyrimethamine (SP) is considered an alternative treatment for acute uncomplicated malaria caused by Plasmodium falciparum resistant to chloroquine. However, the appearance of resistance to this drug has been reported since its initial use in Colombia. Molecular analysis of the dihydrofolate reductase gene indicates a correlation between in vitro(More)
The resurgence and spread of antimalarial drug resistance is one of the causes of the worldwide increase of malaria. In Colombia, uncomplicated Plasmodium falciparum malaria has been treated with a combination of amodiaquine (AQ) and sulfadoxine/pyrimethamine (SP) since 2000. The efficacy of these two antimalarials was evaluated after the implementation of(More)
This study assessed the number of CD4 T lymphocytes, the parasitemia and serum levels of interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), IL-4 and IL-10 of patients infected by human immunodeficiency virus (HIV) and human immunodeficiency virus/Chagas’ disease coinfection. CD4 T lymphocytes were low in the two groups of(More)
Trypanosoma cruzi (Tc), the causative agent of Chagas disease, affects millions of people worldwide. One of the major characteristics of T. cruzi is related to its heterogeneity due to the variability of its biological properties, parasite growth rates, infectivity, tissue tropism, morbidity and virulence among different isolates observed during(More)