Martha Lucía Díaz

Differential expression of Trypanosoma cruzi I associated with clinical forms of Chagas disease: Overexpression of oxidative stress proteins in acute patient isolate

Chagas disease has a variable clinical course with different manifestations and heterogenous geographical distribution. Some studies suggest that this clinical variability could be influenced by the genetic variability of T. cruzi. Here we present the differential protein expression among trypomastigotes and amastigotes of T. cruzi group I isolates from patients with acute and chronic form of Chagas disease from Santander, Colombia. A total of 29 proteins were identified by MALDI-TOF and LC-MS/MS; twenty in trypomastigote and nine in amastigote stage. The 29 proteins identified were grouped in 7 functional categories: 1) metabolism 31%, 2) assembly of cytoskeleton 13.7%, 3) protein destination 13.7%, 4) defenses antioxidants 20.6%, 5) protein synthesis and cellular cycle 13.7%, 6) catabolism 6.8%, and 7) adhesion 3.4%. Tryparedoxin peroxidase, lipoamide dehydrogenase, tyrosine amino transferase and HSP70 were overexpressed in the acute Chagas isolate. Tryparedoxin peroxidase overexpression in the acute isolate was confirmed by Western blot analysis. Most of these proteins are associated with resistance to oxidative stress facilitating their survival within host cells. Therefore, these proteins may represent virulence factors associated with the development of the acute form of the disease and could be used as biomarkers of the clinical course of disease and as drug targets.

Factores asociados con la participación de pacientes en ensayos clínicos en cáncer

Background Cancer clinical trials require the voluntary participation of patients for their adequate development. Not all patients wish to do this, thus affecting their development. In other studies, the most important identified reasons in that influence the decision have been lack of information about study design, randomisation methods, and kind of treatment, use of placebos, toxicity, and side effects of the investigational medicinal product.

OriginalFactores asociados con la participación de pacientes en ensayos clínicos en cáncerSome reasons why patients take part in cancer clinical trials

Background Cancer clinical trials require the voluntary participation of patients for their adequate development. Not all patients wish to do this, thus affecting their development. In other studies, the most important identified reasons in that influence the decision have been lack of information about study design, randomisation methods, and kind of treatment, use of placebos, toxicity, and side effects of the investigational medicinal product.

Differential protein expression in developmental stages of Trypanosoma cruzi I isolated from a patient with chronic chagasic cardiomyopathy

INTRODUCTION Trypanosoma cruzi is the causative agent of Chagas disease. During infection in mammalian hosts, two main forms of the parasite are observed: trypomastigotes and amastigotes. During differentiation, each stage of the parasite expresses a pattern of proteins specific to each phase-proteins which are responsible for the cells morphological, biochemical and biological properties. These properties ultimately govern the infectivity, virulence and survival of the parasite. OBJECTIVE A differential expression analysis was conducted to compare trypomastigote and amastigote stages of T. cruzi I isolate, and to identify proteins differentially expressed by means of mass spectrometry. MATERIALS AND METHODS A T. cruzi clone of the strain MHOM/07/338 was used to analyze the differential expression between trypomastigote stages of a T. cruzi isolate, using two-dimensional electrophoresis and identification of differentially expressed proteins by mass spectrometry. The protein profiles of the stages of the parasite were obtained by two-dimensional gel electrophoresis and visualized in gels dyed with Coomassie blue. The images were analyzed with PDQuest software and the differential expression of the proteins was identified by MALDI TOF or LC MS/MS. RESULTS The two-dimensional gels revealed an average of 325 protein spots in each stage. The comparative analyses detected 21 spots that were over expressed in the trypomastigote stage and 30 in the amastigote stage. Sixteen of the over expressed proteins were selected for identification by mass spectrometry and classified in several functional categories. Mass spectrophotometry determined that the proteins were associated mainly with glucolytic metabolism and assembly of the cytoskeleton constituents. CONCLUSIONS The differential expression between trypomastigote and amastigote stages consisted of proteins specific to T. cruzi and are potential targets for the design of treatment drugs.