oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Characterization of subpopulations (clones and subclones) of the 21 SF strain of Trypanosoma cruzi after long lasting maintenance in the laboratory
Campos, Rozalia MF;Andrade, Sonia G;
Memórias do Instituto Oswaldo Cruz , 1996, DOI: 10.1590/S0074-02761996000600029
Abstract: several studies have shown a clonal structure of trypanosoma cruzi and its possible correlation with the behavioral heterogeneity of the parasite strains. in the present study, the 21 sf strain, that have been maintained in laboratory by successive passages in mice, for more than 15 years, showing a stability of biological and isoenzymic characteristics has been cloned, with the objective of establishing the characters of its clones and subclones. with the technique of isolation of a single parasite from the blood of infected mice, 5 clones and 14 subclones have been obtained. after four passages into mice, inoculum of 105 was obtained for each clone and subclone and inoculated into mice weighing 10 to 12 g. these were used for the study of the biological behavior of the clones: evolution of parasitemia, morphology of blood forms and host mortality. for isoenzymic characterization, the clones and subclones were analyzed for alat, asat, gpi and pgm enzymes. results have shown that the 5 clones and the 14 subclones disclosed a biological behavior similar to the parental strain, with minor variability of the parasitemic profiles and also the same isoenzymic patterns. these results confirm the stability of the 21 sf strain and indicate a clonal homogeneity of its populations. this is compatible with the hypothesis that the t. cruzi strains represent an equilibrium of either homogenous or heterogeneous populations.
Comparative Analysis by Polymerase Chain Reaction Amplified Minicircles of Kinetoplast DNA of a Stable Strain of Trypanosoma cruzi from S?o Felipe, Bahia, its Clones and Subclones: Possibility of Predominance of a Principal Clone in this Area
Campos, Rozalia F;Gon?alves, Marilda S;Reis, Eliana AG dos;Reis, Mitermayer G dos;Andrade, Sonia G;
Memórias do Instituto Oswaldo Cruz , 1999, DOI: 10.1590/S0074-02761999000100009
Abstract: molecular characterization of one stable strain of trypanosoma cruzi, the 21 sf, representative of the pattern of strains isolated from the endemic area of s?o felipe, state of bahia, brazil, maintained for 15 years in laboratory by serial passages in mice and classified as biodeme type ii and zymodeme 2 has been investigated. the kinetoplast dna (kdna) of parental strain, 5 clones and 14 subclones were analyzed. schizodeme was established by comparative study of the fragments obtained from digestion of the 330-bp fragments amplified by polymerase chain reaction (pcr) from the variable regions of the minicicles, and digested by restriction endonucleases rsa i and hinf i. our results show a high percentual of similarity between the restriction fragment lenght polymorphism (rflp) for the parental strain and its clones and among these individual clones and their subclones at a level of 80 to 100%.this homology indicates a predominance of the same "principal clone" in the 21sf strain and confirms the homogeneity previously observed at biological and isozymic analysis. these results suggest the possibility that the t. cruzi strains with similar biological and isoenzymic patterns, circulating in this endemic area, are representative of one dominant clone. the presence of "principal clones" could be responsible for a predominant tropism of the parasites for specific organs and tissues and this could contribute to the pattern of clinico-pathological manifestations of chagas's disease in one geographical area.
Comparative Analysis by Polymerase Chain Reaction Amplified Minicircles of Kinetoplast DNA of a Stable Strain of Trypanosoma cruzi from S o Felipe, Bahia, its Clones and Subclones: Possibility of Predominance of a Principal Clone in this Area  [cached]
Campos Rozalia F,Gon?alves Marilda S,Reis Eliana AG dos,Reis Mitermayer G dos
Memórias do Instituto Oswaldo Cruz , 1999,
Abstract: Molecular characterization of one stable strain of Trypanosoma cruzi, the 21 SF, representative of the pattern of strains isolated from the endemic area of S o Felipe, State of Bahia, Brazil, maintained for 15 years in laboratory by serial passages in mice and classified as biodeme Type II and zymodeme 2 has been investigated. The kinetoplast DNA (kDNA) of parental strain, 5 clones and 14 subclones were analyzed. Schizodeme was established by comparative study of the fragments obtained from digestion of the 330-bp fragments amplified by polymerase chain reaction (PCR) from the variable regions of the minicicles, and digested by restriction endonucleases Rsa I and Hinf I. Our results show a high percentual of similarity between the restriction fragment lenght polymorphism (RFLP) for the parental strain and its clones and among these individual clones and their subclones at a level of 80 to 100%.This homology indicates a predominance of the same "principal clone" in the 21SF strain and confirms the homogeneity previously observed at biological and isozymic analysis. These results suggest the possibility that the T. cruzi strains with similar biological and isoenzymic patterns, circulating in this endemic area, are representative of one dominant clone. The presence of "principal clones" could be responsible for a predominant tropism of the parasites for specific organs and tissues and this could contribute to the pattern of clinico-pathological manifestations of Chagas's disease in one geographical area.
Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model
Gómez-Hernández, César;Rezende-Oliveira, Karine;Nascentes, Gabriel Ant?nio Nogueira;Batista, Lara Rocha;Kappel, Henrique Borges;Martinez-Ibarra, José Alejandro;Trujillo Contreras, Francisco;Lages-Silva, Eliane;Ramírez, Luis Eduardo;
Revista da Sociedade Brasileira de Medicina Tropical , 2011, DOI: 10.1590/S0037-86822011005000058
Abstract: introduction: for a long time, the importance of chagas disease in mexico, where many regarded it as an exotic malady, was questioned. considering the great genetic diversity among isolates of trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of chagas disease in mexico, this study aimed to identify the molecular and biological characterization of trypanosoma cruzi isolates from different endemic areas of this country, especially of the state of jalisco. methods: eight mexican trypanosoma cruzi strains were biologically and genetically characterized (pcr specific for trypanosoma cruzi, multiplex-pcr, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, rapd - (random amplified polymorphic dna). results: two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×106 to 107 parasites/ml) and subpatent. in addition, all isolates were able to infect 100% of the animals. the isolates mainly displayed tropism for striated (cardiac and skeletal) muscle. pcr amplification of the mini-exon gene classified the eight strains as tci. the rapd technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. conclusions: the mexican t. cruzi strains are myotrophic and belong to group tci.
Trypanosoma cruzi isolates from Mexican and Guatemalan acute and chronic chagasic cardiopathy patients belong to Trypanosoma cruzi I
Ruíz-Sánchez, Rosario;León, María Paula de;Matta, Vivian;Reyes, Pedro A;López, R;Jay, David;Monteón, Victor M;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000300012
Abstract: trypanosoma cruzi is classified into two major groups named t. cruzi i and t. cruzi ii. in the present work we analyzed 16 stocks isolated from human cases and four isolated from triatomines from diverse geographical origins (mexico and guatemala). from human cases four were acute cases, six indeterminates, and six from chronic chagasic cardiophatic patients with diagnosis of dilated cardiomyopathy established based on the left-ventricular end systolic dimension and cardiothoracic ratio on chest x-radiography and impaired contracting ventricle and different degree conduction/rhythm aberrations. dna samples were analyzed based on mini-exon (me) polymorphism, using a pool of three oligonucleotide for the amplification of specific intergenic region of t. cruzi me gene. all the mexican and guatemalan isolates regardless their host or vector origin generated a 350 bp amplification product. in conclusion t. cruzi i is dominant in mexico and guatemala even in acute and chronic chagasic cardiopathy patients. to our knowledge, this is the first study describing predominance of t. cruzi i in human infection for north and central america.
Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II)
Campos, Rozália Figueira;Guerreiro, Marcos Lázaro S.;Sobral, Karina de Souza Castro;Lima, Rita de Cássia P. Cunha;Andrade, Sonia G.;
Revista da Sociedade Brasileira de Medicina Tropical , 2005, DOI: 10.1590/S0037-86822005000200003
Abstract: susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 sf strain (biodeme type ii, trypanosoma cruzi ii). swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days). treatment determined negativity of the parasitemia. cure rates were evaluated by parasitological cure tests. serology was evaluated for treated animals (titers from negative to 1:640) and untreated controls (1:160 to 1:640). cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. results suggested that the variability of response to treatment of the clonal populations of trypanosoma cruzi ii strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.
Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II)
Campos Rozália Figueira,Guerreiro Marcos Lázaro S.,Sobral Karina de Souza Castro,Lima Rita de Cássia P. Cunha
Revista da Sociedade Brasileira de Medicina Tropical , 2005,
Abstract: Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II). Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days). Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640) and untreated controls (1:160 to 1:640). Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.
Trypanosoma cruzi: expression of antigenic component 5 among 35 laboratory clones obtained from 18 different isozymic variants
Breniere, Simone F.;Revollo, Susana;Caillard, Thierry;Velatte, Eric;Legrand, Dominique;Afchain, Daniel;Desjeux, Philippe;
Revista do Instituto de Medicina Tropical de S?o Paulo , 1987, DOI: 10.1590/S0036-46651987000200003
Abstract: two monoclonal antibodies anti-component 5 of trypanosoma cruzi (i-35/115 and ii-190/30) were tested in ifa and elisa respectively against 35 t. cruzi laboratory clones. among the 35 clones tested, 18 different isozyme patterns were detected. all clones were recognized by both monoclonal antibodies except one clone which did not react with ii-190/30. these results support the universal expression of specific component 5 within the taxon t. cruzi.
Mexican Trypanosoma cruzi stocks: analysis of minicircle kDNA homologies by cross-hybridization
Bosseno, Marie-France;Espinoza, Bertha;Sánchez, Beatriz;Brenière, Simone Frédérique;
Memórias do Instituto Oswaldo Cruz , 2000, DOI: 10.1590/S0074-02762000000400005
Abstract: homologies of minicircle kdna of 27 mexican stocks were studied by cross-hybridization with four kdna probes derived from three reference stocks belonging to groups trypanosoma cruzi i (so34 cl4 and silvio) and t. cruzi ii (mn) and one mexican stock. high homologies were only observed with silvio (six stocks) and mexican probes (11 stocks). after 30 min exposure (low homology) additional stocks were recognized with so34 cl4 (three stocks) and silvio (six stocks) probes; with the mexican probe only five stocks remained non-reactive. all the stocks were typed by isoenzyme (16 loci) and mexican stocks belonged to t. cruzi i. hybridization patterns were not strictly correlated with the observed clustering and cross-hybridization of kdna minicircles is not available to distinct mexican stocks.
Mexican Trypanosoma cruzi stocks: analysis of minicircle kDNA homologies by cross-hybridization  [cached]
Bosseno Marie-France,Espinoza Bertha,Sánchez Beatriz,Brenière Simone Frédérique
Memórias do Instituto Oswaldo Cruz , 2000,
Abstract: Homologies of minicircle kDNA of 27 Mexican stocks were studied by cross-hybridization with four kDNA probes derived from three reference stocks belonging to groups Trypanosoma cruzi I (SO34 cl4 and Silvio) and T. cruzi II (MN) and one Mexican stock. High homologies were only observed with Silvio (six stocks) and Mexican probes (11 stocks). After 30 min exposure (low homology) additional stocks were recognized with SO34 cl4 (three stocks) and Silvio (six stocks) probes; with the Mexican probe only five stocks remained non-reactive. All the stocks were typed by isoenzyme (16 loci) and Mexican stocks belonged to T. cruzi I. Hybridization patterns were not strictly correlated with the observed clustering and cross-hybridization of kDNA minicircles is not available to distinct Mexican stocks.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.