23 results on '"Parrado, Rudy"'
Search Results
2. Leishmaniasis in Chapare, Bolivia
- Author
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Rojas, Ernesto, Parrado, Rudy, Delgado, Raul, Reithinger, Richard, and Garcia, Ana L.
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Company distribution practices ,Leishmaniasis -- Risk factors ,Leishmaniasis -- Distribution ,Leishmaniasis -- Drug therapy ,Leishmaniasis -- Research ,Disease transmission -- Control ,Disease transmission -- Research - Abstract
To the Editor: In Bolivia, most cases of leishmaniasis are caused by Leishmania (Viannia) braziliensis (1). The parasite is transmitted zoonotically by several sandfly species and, when transmitted to humans, [...]
- Published
- 2009
3. Sequence analysis of the 3’-untranslated region of HSP70 (type I) genes in the genus Leishmania: its usefulness as a molecular marker for species identification
- Author
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Requena Jose M, Chicharro Carmen, García Lineth, Parrado Rudy, Puerta Concepción J, and Cañavate Carmen
- Subjects
Leishmania ,HSP70 ,3’UTR ,Sequence analysis ,Microsatellites ,Phylogenetic analysis ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background The Leishmaniases are a group of clinically diverse diseases caused by parasites of the genus Leishmania. To distinguish between species is crucial for correct diagnosis and prognosis as well as for treatment decisions. Recently, sequencing of the HSP70 coding region has been applied in phylogenetic studies and for identifying of Leishmania species with excellent results. Methods In the present study, we analyzed the 3’-untranslated region (UTR) of Leishmania HSP70-type I gene from 24 strains representing eleven Leishmania species in the belief that this non-coding region would have a better discriminatory capacity for species typing than coding regions. Results It was observed that there was a remarkable degree of sequence conservation in this region, even between species of the subgenus Leishmania and Viannia. In addition, the presence of many microsatellites was a common feature of the 3´-UTR of HSP70-I genes in the Leishmania genus. Finally, we constructed dendrograms based on global sequence alignments of the analyzed Leishmania species and strains, the results indicated that this particular region of HSP70 genes might be useful for species (or species complex) typing, improving for particular species the discrimination capacity of phylogenetic trees based on HSP70 coding sequences. Given the large size variation of the analyzed region between the Leishmania and Viannia subgenera, direct visualization of the PCR amplification product would allow discrimination between subgenera, and a HaeIII-PCR-RFLP analysis might be used for differentiating some species within each subgenera. Conclusions Sequence and phylogenetic analyses indicated that this region, which is readily amplified using a single pair of primers from both Old and New World Leishmania species, might be useful as a molecular marker for species discrimination.
- Published
- 2012
- Full Text
- View/download PDF
4. Usefulness of Serial Blood Sampling and PCR Replicates for Treatment Monitoring of Patients with Chronic Chagas Disease
- Author
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Parrado, Rudy, primary, Ramirez, Juan Carlos, additional, de la Barra, Anabelle, additional, Alonso-Vega, Cristina, additional, Juiz, Natalia, additional, Ortiz, Lourdes, additional, Illanes, Daniel, additional, Torrico, Faustino, additional, Gascon, Joaquim, additional, Alves, Fabiana, additional, Flevaud, Laurence, additional, Garcia, Lineth, additional, Schijman, Alejandro G., additional, and Ribeiro, Isabela, additional
- Published
- 2019
- Full Text
- View/download PDF
5. First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease
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Ramírez, Juan C., Parrado, Rudy, Sulleiro Igual, Elena, de la Barra, Anabelle, Rodríguez, Marcelo, Villarroel, Sandro, Irazu, Lucía, Alonso-Vega, Cristina, Alves, Fabiana, Curto, María A., García, Lineth, Ortiz, Lourdes, Torrico, Faustino, Gascon, Joaquim, Flevaud, Laurence, Molina Romero, Israel, Ribeiro, Isabela, Schijman, Alejandro G., Universitat Autònoma de Barcelona, and Universitat de Barcelona
- Subjects
0301 basic medicine ,Chagas disease ,Posaconazole ,Molecular biology ,lcsh:Medicine ,Artificial Gene Amplification and Extension ,Satellite DNA ,Ravuconazole ,Polymerase Chain Reaction ,Biochemistry ,Geographical locations ,purl.org/becyt/ford/1 [https] ,0302 clinical medicine ,Malaltia de Chagas ,Medicine and Health Sciences ,lcsh:Science ,Protozoans ,Trypanosoma Cruzi ,Multidisciplinary ,External quality assurance ,Eukaryota ,Trypanocidal Agents ,Clinical Laboratory Sciences ,3. Good health ,Nucleic acids ,Clinical Laboratories ,Nitroimidazoles ,Benznidazole ,CIENCIAS NATURALES Y EXACTAS ,Research Article ,medicine.drug ,Trypanosoma ,Bolivia ,medicine.medical_specialty ,Drug Research and Development ,Forms of DNA ,Otras Ciencias Biológicas ,Concordance ,030231 tropical medicine ,030106 microbiology ,Real-Time Polymerase Chain Reaction ,Research and Analysis Methods ,Ciencias Biológicas ,03 medical and health sciences ,Diagnostic Medicine ,Internal medicine ,parasitic diseases ,Parasitic Diseases ,Genetics ,medicine ,Humans ,Chagas Disease ,Clinical Trials ,purl.org/becyt/ford/1.6 [https] ,Molecular Biology Techniques ,Molecular Biology ,Monitoring, Physiologic ,Biologia molecular ,Pharmacology ,proficiency testing ,business.industry ,lcsh:R ,Organisms ,Biology and Life Sciences ,DNA ,Triazoles ,South America ,Molecular diagnostics ,medicine.disease ,Parasitic Protozoans ,Clinical trial ,Chagas' disease ,Immunology ,lcsh:Q ,Real-Time PCR ,Clinical Medicine ,People and places ,business ,Quality assurance - Abstract
Real-Time PCR (qPCR) testing is recommended as both a diagnostic and outcome measurement of etiological treatment in clinical practice and clinical trials of Chagas disease (CD), but no external quality assurance (EQA) program provides performance assessment of the assays in use. We implemented an EQA system to evaluate the performance of molecular biology laboratories involved in qPCR based follow-up in clinical trials of CD. An EQA program was devised for three clinical trials of CD: the E1224 (NCT01489228), a pro-drug of ravuconazole; the Sampling Study (NCT01678599), that used benznidazole, both conducted in Bolivia; and the CHAGASAZOL (NCT01162967), that tested posaconazole, conducted in Spain. Four proficiency testing panels containing negative controls and seronegative blood samples spiked with 1, 10 and 100 parasite equivalents (par. eq.)/mL of four Trypanosoma cruzi stocks, were sent from the Core Lab in Argentina to the participating laboratories located in Bolivia and Spain. Panels were analyzed simultaneously, blinded to sample allocation, at 4-month intervals. In addition, 302 random blood samples from both trials carried out in Bolivia were sent to Core Lab for retesting analysis. The analysis of proficiency testing panels gave 100% of accordance (within laboratory agreement) and concordance (between laboratory agreement) for all T. cruzi stocks at 100 par. eq./mL; whereas their values ranged from 71 to 100% and from 62 to 100% at 1 and 10 par. eq./mL, respectively, depending on the T. cruzi stock. The results obtained after twelve months of preparation confirmed the stability of blood samples in guanidine-EDTA buffer. No significant differences were found between qPCR results from Bolivian laboratory and Core Lab for retested clinical samples. This EQA program for qPCR analysis of CD patient samples may significantly contribute to ensuring the quality of laboratory data generated in clinical trials and molecular diagnostics laboratories of CD. Fil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Parrado, Rudy. Universidad Mayor de San Simon; Bolivia Fil: Sulleiro, Elena. Universitat Autònoma de Barcelona; España Fil: De La Barra, Anabelle. Universidad Mayor de San Simon; Bolivia Fil: Rodríguez, Marcelo. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina Fil: Villarroel, Sandro. Universidad Mayor de San Simon; Bolivia Fil: Irazu, Lucía. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina Fil: Alonso Vega, Cristina. Drugs for Neglected Diseases initiative; Suiza Fil: Alves, Fabiana. Drugs for Neglected Diseases initiative; Suiza Fil: Curto, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: García, Lineth. Universidad Mayor de San Simon; Bolivia Fil: Ortiz, Lourdes. Universidad Autonoma Juan Misael Saracho; Bolivia Fil: Torrico, Faustino. Fundacion CEADES; Bolivia Fil: Gascón, Joaquim. Universidad de Barcelona; España Fil: Flevaud, Laurence. Medecins Sans Frontières Operational Center Barcelona-Athens; España Fil: Molina, Israel. Universitat Autònoma de Barcelona; España Fil: Ribeiro, Isabela. Drugs for Neglected Diseases initiative; Suiza Fil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina
- Published
- 2017
6. First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease
- Author
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Ramírez, Juan C., primary, Parrado, Rudy, additional, Sulleiro, Elena, additional, de la Barra, Anabelle, additional, Rodríguez, Marcelo, additional, Villarroel, Sandro, additional, Irazu, Lucía, additional, Alonso-Vega, Cristina, additional, Alves, Fabiana, additional, Curto, María A., additional, García, Lineth, additional, Ortiz, Lourdes, additional, Torrico, Faustino, additional, Gascón, Joaquim, additional, Flevaud, Laurence, additional, Molina, Israel, additional, Ribeiro, Isabela, additional, and Schijman, Alejandro G., additional
- Published
- 2017
- Full Text
- View/download PDF
7. Congenital infection with Trypanosoma cruzi primes cord blood Vd2 T cells to proliferate in response to isopentenyl pyrophosphate
- Author
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Hermann Emmanuel, Flores Amilcar, Berthe Aurlie, Alonso-Vega Cristina, Truyens Carine, Carlier Yves, Parrado Rudy, and Torrico Faustino
- Subjects
chemistry.chemical_compound ,chemistry ,Cord blood ,Immunology ,Isopentenyl pyrophosphate ,Immunology and Allergy ,Biology ,Non-peptidic antigen ,Trypanosoma cruzi ,biology.organism_classification ,Virology - Published
- 2013
8. Analytical Validation of Quantitative Real-Time PCR Methods for Quantification of Trypanosoma cruzi DNA in Blood Samples from Chagas Disease Patients
- Author
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Ramírez, Juan Carlos, primary, Cura, Carolina Inés, additional, da Cruz Moreira, Otacilio, additional, Lages-Silva, Eliane, additional, Juiz, Natalia, additional, Velázquez, Elsa, additional, Ramírez, Juan David, additional, Alberti, Anahí, additional, Pavia, Paula, additional, Flores-Chávez, María Delmans, additional, Muñoz-Calderón, Arturo, additional, Pérez-Morales, Deyanira, additional, Santalla, José, additional, Marcos da Matta Guedes, Paulo, additional, Peneau, Julie, additional, Marcet, Paula, additional, Padilla, Carlos, additional, Cruz-Robles, David, additional, Valencia, Edward, additional, Crisante, Gladys Elena, additional, Greif, Gonzalo, additional, Zulantay, Inés, additional, Costales, Jaime Alfredo, additional, Alvarez-Martínez, Miriam, additional, Martínez, Norma Edith, additional, Villarroel, Rodrigo, additional, Villarroel, Sandro, additional, Sánchez, Zunilda, additional, Bisio, Margarita, additional, Parrado, Rudy, additional, Maria da Cunha Galvão, Lúcia, additional, Jácome da Câmara, Antonia Cláudia, additional, Espinoza, Bertha, additional, Alarcón de Noya, Belkisyole, additional, Puerta, Concepción, additional, Riarte, Adelina, additional, Diosque, Patricio, additional, Sosa-Estani, Sergio, additional, Guhl, Felipe, additional, Ribeiro, Isabela, additional, Aznar, Christine, additional, Britto, Constança, additional, Yadón, Zaida Estela, additional, and Schijman, Alejandro G., additional
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- 2015
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9. Sequence analysis of the 3-untranslated region of HSP70 (type I) genes in the genus Leishmania: Its usefulness as a molecular marker for species identification
- Author
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Ministerio de Ciencia y Tecnología (España), Instituto de Salud Carlos III, Ministerio de Asuntos Exteriores y Cooperación (España), Fundación Ramón Areces, Requena, José María, Chicharro, Carmen, García, Lineth, Parrado, Rudy, Puerta, Concepción J., Cañavate, Carmen, Ministerio de Ciencia y Tecnología (España), Instituto de Salud Carlos III, Ministerio de Asuntos Exteriores y Cooperación (España), Fundación Ramón Areces, Requena, José María, Chicharro, Carmen, García, Lineth, Parrado, Rudy, Puerta, Concepción J., and Cañavate, Carmen
- Abstract
Background: The Leishmaniases are a group of clinically diverse diseases caused by parasites of the genus Leishmania. To distinguish between species is crucial for correct diagnosis and prognosis as well as for treatment decisions. Recently, sequencing of the HSP70 coding region has been applied in phylogenetic studies and for identifying of Leishmania species with excellent results. Methods: In the present study, we analyzed the 3-untranslated region (UTR) of Leishmania HSP70-type I gene from 24 strains representing eleven Leishmania species in the belief that this non-coding region would have a better discriminatory capacity for species typing than coding regions. Results: It was observed that there was a remarkable degree of sequence conservation in this region, evenbetween species of the subgenus Leishmania and Viannia. In addition, the presence of many microsatellites was a common feature of the 3-UTR of HSP70-I genes in the Leishmania genus. Finally, we constructed dendrograms based on global sequence alignments of the analyzed Leishmania species and strains, the results indicated that this particular region of HSP70 genes might be useful for species (or species complex) typing, improving for particular species the discrimination capacity of phylogenetic trees based on HSP70 coding sequences. Given the large size variation of the analyzed region between the Leishmania and Viannia subgenera, direct visualization of the PCR amplification product would allow discrimination between subgenera, and a HaeIII-PCR-RFLP analysis might be used for differentiating some species within each subgenera. Conclusions: Sequence and hylogenetic analyses indicated that this region, which is readily amplified using a single pair of primers from both Old and New World Leishmania species, might be useful as a molecular marker for species discrimination. © 2012 Requena et al.; licensee BioMed Central Ltd.
- Published
- 2012
10. Sequence analysis of the 3'-untranslated region of HSP70 (type I) genes in the genus Leishmania: its usefulness as a molecular marker for species identification
- Author
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Requena, José María, Chicharro, Carmen, García, Lineth, Parrado, Rudy, Puerta, Concepción J., Cañavate, Carmen, Requena, José María, Chicharro, Carmen, García, Lineth, Parrado, Rudy, Puerta, Concepción J., and Cañavate, Carmen
- Abstract
BackgroundThe Leishmaniases are a group of clinically diverse diseases caused by parasites of the genus Leishmania. To distinguish between species is crucial for correct diagnosis and prognosis as well as for treatment decisions. Recently, sequencing of the HSP70 coding region has been applied in phylogenetic studies and for identifying of Leishmania species with excellent results.MethodsIn the present study, we analyzed the 3’-untranslated region (UTR) of Leishmania HSP70-type I gene from 24 strains representing eleven Leishmania species in the belief that this non-coding region would have a better discriminatory capacity for species typing than coding regions.ResultsIt was observed that there was a remarkable degree of sequence conservation in this region, even between species of the subgenus Leishmania and Viannia. In addition, the presence of many microsatellites was a common feature of the 3´-UTR of HSP70-I genes in the Leishmania genus. Finally, we constructed dendrograms based on global sequence alignments of the analyzed Leishmania species and strains, the results indicated that this particular region of HSP70 genes might be useful for species (or species complex) typing, improving for particular species the discrimination capacity of phylogenetic trees based on HSP70 coding sequences. Given the large size variation of the analyzed region between the Leishmania and Viannia subgenera, direct visualization of the PCR amplification product would allow discrimination between subgenera, and a HaeIII-PCR-RFLP analysis might be used for differentiating some species within each subgenera.ConclusionsSequence and phylogenetic analyses indicated that this region, which is readily amplified using a single pair of primers from both Old and New World Leishmania species, might be useful as a molecular marker for species discrimination.
- Published
- 2012
11. Killer cell immunoglobulin-like receptor expression induction on neonatal CD8(+) T cells in vitro and following congenital infection with Trypanosoma cruzi.
- Author
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Hermann, Emmanuel, Berthe, Aurélie, Truyens, Carine, Alonso-Vega, Cristina, Parrado, Rudy, Torrico, F, Carlier, Yves, Braud, Veronique, Hermann, Emmanuel, Berthe, Aurélie, Truyens, Carine, Alonso-Vega, Cristina, Parrado, Rudy, Torrico, F, Carlier, Yves, and Braud, Veronique
- Abstract
Major histocompatibility complex (MHC) class I-specific inhibitory natural killer receptors (iNKRs) are expressed by subsets of T cells but the mechanisms inducing their expression are poorly understood, particularly for killer-cell immunoglobulin-like receptors (KIRs). The iNKRs are virtually absent from the surface of cord blood T cells but we found that KIR expression could be induced upon interleukin-2 stimulation in vitro. In addition, KIR expression was enhanced after treatment with 5-aza-2'-deoxycytidine, suggesting a role for DNA methylation. In vivo induction of KIR expression on cord blood T cells was also observed during a human congenital infection with Trypanosoma cruzi which triggers activation of fetal CD8(+) T cells. These KIR(+) T cells had an effector and effector/memory phenotype suggesting that KIR expression was consecutive to the antigenic stimulation; however, KIR was not preferentially found on parasite-specific CD8(+) T cells secreting interferon-gamma upon in vitro restimulation with live T. cruzi. These findings show that KIR expression is likely regulated by epigenetic mechanisms that occur during the maturation process of cord blood T cells. Our data provide a molecular basis for the appearance of KIRs on T cells with age and they have implications for T-cell homeostasis and the regulation of T-cell-mediated immune responses., JOURNAL ARTICLE, SCOPUS: ar.j, FLWIN, info:eu-repo/semantics/published
- Published
- 2009
12. Analytical Performance of a Multiplex Real-Time PCR Assay Using TaqMan Probes for Quantification of Trypanosoma cruzi Satellite DNA in Blood Samples
- Author
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Duffy, Tomas, primary, Cura, Carolina I., additional, Ramirez, Juan C., additional, Abate, Teresa, additional, Cayo, Nelly M., additional, Parrado, Rudy, additional, Bello, Zoraida Diaz, additional, Velazquez, Elsa, additional, Muñoz-Calderon, Arturo, additional, Juiz, Natalia A., additional, Basile, Joaquín, additional, Garcia, Lineth, additional, Riarte, Adelina, additional, Nasser, Julio R., additional, Ocampo, Susana B., additional, Yadon, Zaida E., additional, Torrico, Faustino, additional, de Noya, Belkisyole Alarcón, additional, Ribeiro, Isabela, additional, and Schijman, Alejandro G., additional
- Published
- 2013
- Full Text
- View/download PDF
13. Amniotic fluid is not useful for diagnosis of congenital Trypanosoma cruzi infection.
- Author
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Virreira Bermudez, Myrna, Martinez, Sabrina, Alonso-Vega, Cristina, Torrico, F, Solano, Marco Antonio, Torrico, Mary Cruz, Parrado, Rudy, Truyens, Carine, Carlier, Yves, Svoboda, Michal, Virreira Bermudez, Myrna, Martinez, Sabrina, Alonso-Vega, Cristina, Torrico, F, Solano, Marco Antonio, Torrico, Mary Cruz, Parrado, Rudy, Truyens, Carine, Carlier, Yves, and Svoboda, Michal
- Abstract
Although Trypanosoma cruzi can be transmitted transplacentally and induce congenital infection, no data are available about the presence of this parasite in human amniotic fluid. We examined 8, 19, and 4 amniotic fluid samples (collected at delivery or by aspiration of gastric content of neonates) from control uninfected mothers (M-B-), infected mothers delivering uninfected newborns (M+B-), and mothers of confirmed congenital cases (M+B+), respectively. Polymerase chain reaction (PCR), using nuclear and kinetoplastic DNA primers (Tcz1-Tcz2 and 121-122), were negative for all control M-B- samples, but positive for 5 of 19 M+B- and 2 of 4 M+B+ samples. To determine the number of parasites in the positive samples, real-time PCR using S35/S36 kinetoplastic DNA was performed. Only one M+B+ sample presented a high parasitic DNA amount, whereas the other six PCR-positive samples displayed traces of T. cruzi DNA. In conclusion, the release of parasites in amniotic fluid is probably a rare event that cannot be helpful for the routine diagnosis of congenital Chagas disease., Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., info:eu-repo/semantics/published
- Published
- 2006
14. Estimación de la parasitemia en la infección humana por Trypanosoma cruzi: las altas parasitemias están asociadas con la severa y fatal enfermedad de Chagas congenita.
- Author
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Torrico, Mary Cruz, Solano, Marco Antonio, Guzmán, José Miguel, Parrado, Rudy, Suarez, Eduardo, Alonso-Vega, Cristina, Truyens, Carine, Carlier, Yves, Torrico, F, Torrico, Mary Cruz, Solano, Marco Antonio, Guzmán, José Miguel, Parrado, Rudy, Suarez, Eduardo, Alonso-Vega, Cristina, Truyens, Carine, Carlier, Yves, and Torrico, F
- Abstract
The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease., English Abstract, Journal Article, Validation Studies, info:eu-repo/semantics/published
- Published
- 2005
15. Killer cell immunoglobulin-like receptor expression induction on neonatal CD8+T cellsin vitroand following congenital infection withTrypanosoma cruzi
- Author
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Hermann, Emmanuel, primary, Berthe, Aurélie, additional, Truyens, Carine, additional, Alonso-Vega, Cristina, additional, Parrado, Rudy, additional, Torrico, Faustino, additional, Carlier, Yves, additional, and Braud, Véronique M., additional
- Published
- 2010
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- View/download PDF
16. Co-Infection of Leishmania (Viannia) braziliensis and HIV: Report of a Case of Mucosal Leishmaniasis in Cochabamba, Bolivia
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Torrico, Faustino, primary, Solano, Marco, additional, Reithinger, Richard, additional, Castro, Rosario, additional, Marquez, Carla Jimena, additional, Torrico, Mary Cruz, additional, García, Ana Lineth, additional, and Parrado, Rudy, additional
- Published
- 2009
- Full Text
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17. Leishmaniases in Bolivia: Comprehensive Review and Current Status
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García, Ana L., primary, Parrado, Rudy, additional, Rojas, Ernesto, additional, Reithinger, Richard, additional, Delgado, Raúl, additional, and Dujardin, Jean-Claude, additional
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- 2009
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18. Multiprimer PCR System Diagnosis of Pulmonary Tuberculosis in Cochabamba, Bolivia
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Parrado, Rudy, primary, Lozano, Daniel, additional, Garcia, Lineth, additional, Torrico, Mary Cruz, additional, Delgado, Raúl, additional, Torrico, Faustino, additional, Laserna, Monica, additional, and Reithinger, Richard, additional
- Published
- 2008
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19. AMNIOTIC FLUID IS NOT USEFUL FOR DIAGNOSIS OF CONGENITAL TRYPANOSOMA CRUZI INFECTION
- Author
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VIRREIRA, MYRNA, primary, CARLIER, YVES, additional, TORRICO, FAUSTINO, additional, SOLANO, MARCO, additional, PARRADO, RUDY, additional, MARTINEZ, SABRINA, additional, TRUYENS, CARINE, additional, ALONSO-VEGA, CRISTINA, additional, SVOBODA, MICHAL, additional, and TORRICO, MARY CRUZ, additional
- Published
- 2006
- Full Text
- View/download PDF
20. Analytical Validation of Quantitative Real-Time PCR Methods for Quantification of Trypanosoma cruziDNA in Blood Samples from Chagas Disease Patients
- Author
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Ramírez, Juan Carlos, Cura, Carolina Inés, da Cruz Moreira, Otacilio, Lages-Silva, Eliane, Juiz, Natalia, Velázquez, Elsa, Ramírez, Juan David, Alberti, Anahí, Pavia, Paula, Flores-Chávez, María Delmans, Muñoz-Calderón, Arturo, Pérez-Morales, Deyanira, Santalla, José, Marcos da Matta Guedes, Paulo, Peneau, Julie, Marcet, Paula, Padilla, Carlos, Cruz-Robles, David, Valencia, Edward, Crisante, Gladys Elena, Greif, Gonzalo, Zulantay, Inés, Costales, Jaime Alfredo, Alvarez-Martínez, Miriam, Martínez, Norma Edith, Villarroel, Rodrigo, Villarroel, Sandro, Sánchez, Zunilda, Bisio, Margarita, Parrado, Rudy, Maria da Cunha Galvão, Lúcia, Jácome da Câmara, Antonia Cláudia, Espinoza, Bertha, Alarcón de Noya, Belkisyole, Puerta, Concepción, Riarte, Adelina, Diosque, Patricio, Sosa-Estani, Sergio, Guhl, Felipe, Ribeiro, Isabela, Aznar, Christine, Britto, Constança, Yadón, Zaida Estela, and Schijman, Alejandro G.
- Abstract
An international study was performed by 26 experienced PCR laboratories from 14 countries to assess the performance of duplex quantitative real-time PCR (qPCR) strategies on the basis of TaqMan probes for detection and quantification of parasitic loads in peripheral blood samples from Chagas disease patients. Two methods were studied: Satellite DNA (SatDNA) qPCR and kinetoplastid DNA (kDNA) qPCR. Both methods included an internal amplification control. Reportable range, analytical sensitivity, limits of detection and quantification, and precision were estimated according to international guidelines. In addition, inclusivity and exclusivity were estimated with DNA from stocks representing the different Trypanosoma cruzidiscrete typing units and Trypanosoma rangeliand Leishmaniaspp. Both methods were challenged against 156 blood samples provided by the participant laboratories, including samples from acute and chronic patients with varied clinical findings, infected by oral route or vectorial transmission. kDNA qPCR showed better analytical sensitivity than SatDNA qPCR with limits of detection of 0.23 and 0.70 parasite equivalents/mL, respectively. Analyses of clinical samples revealed a high concordance in terms of sensitivity and parasitic loads determined by both SatDNA and kDNA qPCRs. This effort is a major step toward international validation of qPCR methods for the quantification of T. cruziDNA in human blood samples, aiming to provide an accurate surrogate biomarker for diagnosis and treatment monitoring for patients with Chagas disease.
- Published
- 2015
- Full Text
- View/download PDF
21. Killer cell immunoglobulin-like receptor expression induction on neonatal CD8+ T cells in vitro and following congenital infection with Trypanosoma cruzi.
- Author
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Hermann, Emmanuel, Berthe, Aurélie, Truyens, Carine, Alonso-Vega, Cristina, Parrado, Rudy, Torrico, Faustino, Carlier, Yves, and Braud, Véronique M.
- Subjects
MAJOR histocompatibility complex ,KILLER cells ,T cells ,INTERLEUKIN-2 ,CORD blood ,TRYPANOSOMA cruzi ,IMMUNE response - Abstract
Major histocompatibility complex (MHC) class I-specific inhibitory natural killer receptors (iNKRs) are expressed by subsets of T cells but the mechanisms inducing their expression are poorly understood, particularly for killer-cell immunoglobulin-like receptors (KIRs). The iNKRs are virtually absent from the surface of cord blood T cells but we found that KIR expression could be induced upon interleukin-2 stimulation in vitro. In addition, KIR expression was enhanced after treatment with 5-aza-2′-deoxycytidine, suggesting a role for DNA methylation. In vivo induction of KIR expression on cord blood T cells was also observed during a human congenital infection with Trypanosoma cruzi which triggers activation of fetal CD8
+ T cells. These KIR+ T cells had an effector and effector/memory phenotype suggesting that KIR expression was consecutive to the antigenic stimulation; however, KIR was not preferentially found on parasite-specific CD8+ T cells secreting interferon-γ upon in vitro restimulation with live T. cruzi. These findings show that KIR expression is likely regulated by epigenetic mechanisms that occur during the maturation process of cord blood T cells. Our data provide a molecular basis for the appearance of KIRs on T cells with age and they have implications for T-cell homeostasis and the regulation of T-cell-mediated immune responses. [ABSTRACT FROM AUTHOR]- Published
- 2010
- Full Text
- View/download PDF
22. Usefulness of Serial Blood Sampling and PCR Replicates for Treatment Monitoring of Patients with Chronic Chagas Disease
- Author
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Parrado, Rudy, Ramirez, Juan Carlos, de la Barra, Anabelle, Alonso-Vega, Cristina, Juiz, Natalia, Ortiz, Lourdes, Illanes, Daniel, Torrico, Faustino, Gascon, Joaquim, Alves, Fabiana, Flevaud, Laurence, Garcia, Lineth, Schijman, Alejandro G., and Ribeiro, Isabela
- Abstract
This work evaluated a serial blood sampling procedure to enhance the sensitivity of duplex real-time quantitative PCR (qPCR) for baseline detection and quantification of parasitic loads and posttreatment identification of failure in the context of clinical trials for treatment of chronic Chagas disease, namely, DNDi-CH-E1224-001 (ClinicalTrials.gov registration no. NCT01489228) and the MSF-DNDi PCR Sampling Optimization Study (NCT01678599).
- Published
- 2018
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23. [Estimation of the parasitemia in Trypanosoma cruzi human infection: high parasitemias are associated with severe and fatal congenital Chagas disease].
- Author
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Torrico MC, Solano M, Guzmán JM, Parrado R, Suarez E, Alonzo-Vega C, Truyens C, Carlier Y, and Torrico F
- Subjects
- Animals, Birth Weight, Bolivia epidemiology, Chagas Disease diagnosis, Female, Hematocrit instrumentation, Hematocrit methods, Humans, Infant, Newborn, Male, Mice, Sensitivity and Specificity, Umbilical Cord, Chagas Disease congenital, Chagas Disease parasitology, Parasite Egg Count methods, Parasitemia mortality, Trypanosoma cruzi isolation & purification
- Abstract
The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease.
- Published
- 2005
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