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Autor Juan Guillermo McEwen Ochoa |
Documentos disponibles escritos por este autor (5)
Clasificado(s) por (Año de edición descendente) Refinar búsquedaA culture medium for paracoccidioides brasiliensis with high plating efficiency, and the effect of siderophores / Juan Guillermo McEwen Ochoa
Título : A culture medium for paracoccidioides brasiliensis with high plating efficiency, and the effect of siderophores Tipo de documento : documento electrónico Autores : Juan Guillermo McEwen Ochoa, Fecha de publicación : 1988 Títulos uniformes : Journal of Medical and Veterinary Mycology Idioma : Inglés (eng) Resumen : The plating efficiency of Paracoccidioides brasiliensis on standard mycological media is poor, impairing its isolation and recovery from various sources, particularly infected tissues. We describe a medium that markedly improves P. brasiliensis plating efficiency. It consists of a synthetic medium (modified McVeigh-Morton) supplemented with 4% (v:v) horse serum and 5% (v:v) culture filtrate from stationary phase P. brasiliensis cultures. A commercially available medium (brain-heart infusion), ordinarily inferior to unsupplemented McVeigh-Morton medium, is at least as efficacious as supplemented McVeigh-Morton medium when supplemented in this manner. We show that plating efficiency varies among P. brasiliensis isolates and can even vary with the isolate's history of passage in culture. In contrast, all isolates studied could produce the growth enhancing factors present in culture filtrate, whereas others can be substituted for both the filtrate and serum. The enhancing effect of filtrate and/or serum could be removed by chelating iron. P. brasiliensis-produced siderophores are likely to be the growth enhancing moiety in culture filtrates. Mención de responsabilidad : E. Castaneda, E. Brummer, A.M. Perlman, J.G. McEwen, D.A. Stevens Referencia : J Med Vet Mycol. 1988;26(6):351-8. DOI (Digital Object Identifier) : 10.1080/02681218880000501 PMID : 2977619 En línea : https://academic.oup.com/mmy/article-abstract/26/6/351/917657 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4350 A culture medium for paracoccidioides brasiliensis with high plating efficiency, and the effect of siderophores [documento electrónico] / Juan Guillermo McEwen Ochoa, . - 1988.
Obra : Journal of Medical and Veterinary Mycology
Idioma : Inglés (eng)
Resumen : The plating efficiency of Paracoccidioides brasiliensis on standard mycological media is poor, impairing its isolation and recovery from various sources, particularly infected tissues. We describe a medium that markedly improves P. brasiliensis plating efficiency. It consists of a synthetic medium (modified McVeigh-Morton) supplemented with 4% (v:v) horse serum and 5% (v:v) culture filtrate from stationary phase P. brasiliensis cultures. A commercially available medium (brain-heart infusion), ordinarily inferior to unsupplemented McVeigh-Morton medium, is at least as efficacious as supplemented McVeigh-Morton medium when supplemented in this manner. We show that plating efficiency varies among P. brasiliensis isolates and can even vary with the isolate's history of passage in culture. In contrast, all isolates studied could produce the growth enhancing factors present in culture filtrate, whereas others can be substituted for both the filtrate and serum. The enhancing effect of filtrate and/or serum could be removed by chelating iron. P. brasiliensis-produced siderophores are likely to be the growth enhancing moiety in culture filtrates. Mención de responsabilidad : E. Castaneda, E. Brummer, A.M. Perlman, J.G. McEwen, D.A. Stevens Referencia : J Med Vet Mycol. 1988;26(6):351-8. DOI (Digital Object Identifier) : 10.1080/02681218880000501 PMID : 2977619 En línea : https://academic.oup.com/mmy/article-abstract/26/6/351/917657 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4350 Reserva
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Código de barras Número de Ubicación Tipo de medio Ubicación Sección Estado DD000851 AC-1988-006 Archivo digital Producción Científica Artículos científicos Disponible
Título : Nuclear staining of Paracoccidioides brasiliensis conidia Tipo de documento : documento electrónico Autores : Juan Guillermo McEwen Ochoa, ; Blanca I. Restrepo, ; Maria E. Salazar, ; Ángela Restrepo Moreno, Fecha de publicación : 1987 Títulos uniformes : Journal of Medical and Veterinary Mycology Idioma : Inglés (eng) Resumen : More than 80% of the conidia produced by two different isolates of Paracoccidioides brasiliensis, were found to be uninucleate; however, when they were incubated at 37°C and began to transform into yeast cells, they became bi- or multi-nucleated, so that when most of the conidia had already transformed into yeast cells (72–96 h), there were at least four or five nuclei per cell in approximately 80% of the conidia examined. Mención de responsabilidad : Juan G. McEwen, Blanca I. Restrepo, Maria E. Salazar, Angela Restrepo Referencia : J Med Vet Mycol. 1987 Oct;25(5):343-5 DOI (Digital Object Identifier) : 10.1080/02681218780000411 PMID : 2448446 En línea : https://academic.oup.com/mmy/article-abstract/25/5/343/1299208 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4343 Nuclear staining of Paracoccidioides brasiliensis conidia [documento electrónico] / Juan Guillermo McEwen Ochoa, ; Blanca I. Restrepo, ; Maria E. Salazar, ; Ángela Restrepo Moreno, . - 1987.
Obra : Journal of Medical and Veterinary Mycology
Idioma : Inglés (eng)
Resumen : More than 80% of the conidia produced by two different isolates of Paracoccidioides brasiliensis, were found to be uninucleate; however, when they were incubated at 37°C and began to transform into yeast cells, they became bi- or multi-nucleated, so that when most of the conidia had already transformed into yeast cells (72–96 h), there were at least four or five nuclei per cell in approximately 80% of the conidia examined. Mención de responsabilidad : Juan G. McEwen, Blanca I. Restrepo, Maria E. Salazar, Angela Restrepo Referencia : J Med Vet Mycol. 1987 Oct;25(5):343-5 DOI (Digital Object Identifier) : 10.1080/02681218780000411 PMID : 2448446 En línea : https://academic.oup.com/mmy/article-abstract/25/5/343/1299208 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4343 Reserva
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Código de barras Número de Ubicación Tipo de medio Ubicación Sección Estado DD000844 AC-1987-001 Archivo digital Producción Científica Artículos científicos Disponible
Título : Morphological development of the conidia produced by paracoccidioides brasiliensis mycelial form Tipo de documento : documento electrónico Autores : Blanca I. Restrepo, ; Juan Guillermo McEwen Ochoa, ; Maria E. Salazar, ; Ángela Restrepo Moreno, Fecha de publicación : 1986 Títulos uniformes : Journal of Medical and Veterinary Mycology Idioma : Inglés (eng) Resumen : P. brasiliensis conidia were studied for their ability to grow as yeasts or as molds according to temperature. Using a microculture system we found that such conidia shared the ability of the parent mycelium to transform directly into multiple-budding yeast cells at 36°C or to produce germ tubes and branching mycelia if kept at 22°C. Mención de responsabilidad : Blanca I. Restrepo, Juan G. McEwen, Maria E. Salazar, Angela Restrepo Referencia : J Med Vet Mycol. 1986 Aug;24(4):337-9. DOI (Digital Object Identifier) : 10.1080/02681218680000491 PMID : 3746586 En línea : https://academic.oup.com/mmy/article-abstract/24/4/337/921937 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4339 Morphological development of the conidia produced by paracoccidioides brasiliensis mycelial form [documento electrónico] / Blanca I. Restrepo, ; Juan Guillermo McEwen Ochoa, ; Maria E. Salazar, ; Ángela Restrepo Moreno, . - 1986.
Obra : Journal of Medical and Veterinary Mycology
Idioma : Inglés (eng)
Resumen : P. brasiliensis conidia were studied for their ability to grow as yeasts or as molds according to temperature. Using a microculture system we found that such conidia shared the ability of the parent mycelium to transform directly into multiple-budding yeast cells at 36°C or to produce germ tubes and branching mycelia if kept at 22°C. Mención de responsabilidad : Blanca I. Restrepo, Juan G. McEwen, Maria E. Salazar, Angela Restrepo Referencia : J Med Vet Mycol. 1986 Aug;24(4):337-9. DOI (Digital Object Identifier) : 10.1080/02681218680000491 PMID : 3746586 En línea : https://academic.oup.com/mmy/article-abstract/24/4/337/921937 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4339 Reserva
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Código de barras Número de Ubicación Tipo de medio Ubicación Sección Estado DD000841 AC-1986-007 Archivo digital Producción Científica Artículos científicos Disponible
Título : Pathogenesis of paracoccidioidomycosis: A histopathological study of the experimental murine infection Tipo de documento : documento electrónico Autores : Víctor Bedoya M., ; Juan Guillermo McEwen Ochoa, ; Ángela María Tabares Velásquez, ; Fabio Uribe Jaramillo, ; Ángela Restrepo Moreno, Fecha de publicación : 1986 Títulos uniformes : Mycopathologia Idioma : Inglés (eng) Resumen : The pathogenesis of primary pulmonary P. brasiliensis infection, the systemic dissemination which followed, and the histopathology of the main organs involved was studied in a murine model of chronic paracoccidioidomycosis. Adult male BALB/C mice, were challenged intranasally with 26×10−6 viable P. brasiliensis yeast cells. We inoculated 86 animals which were sacrificed from 0 h to 20 weeks. As controls, 11 mice were instilled with saline solution, and 48 with 26×10−6 heat-killed. P. brasiliensis yeast cells. None of the animals receiving saline, exhibited pathologic alterations; 11.6% of those inoculated with the heatkilled cells, revealed mild, transitory acinopulmonary neutrophilic infiltrates. The animals infected with viable cells, developed a systemic process affecting mainly the lungs (46.5%), liver (18.6%), lymphnodes (18.6%), and spleen (3.5%). In this group of animals, lung lesions were detected regularly at all time periods from 3 h to 20 weeks. A multiple bronchoneumonic process was initially observed at 6 h, reached its maximum intensity around the third day, subsided thereafter but did not disappear and reactivated after the fifth week to become stationary until the end of experiments. Dissemination to other organs occurred early, and apparently by the hematogenous route. Initially the inflammatory cell infiltrate was mainly neutrophilic. With time, these cells were gradually replaced by lymphocytes, histiocytes and plasmocytes. Granuloma configuration of the cell infiltrate was distinctly seen around the fifth week, with multinucleated giant cells appearing at the ninth week. Hiliary lymphnode involvement was rare (7%) and primary lung lesions, as seen in tuberculosis and histoplasmosis, were not observed. Mención de responsabilidad : Víctor Bedoya, Juan G. McEwen, Angela M. Tabares, Fabio Uribe Jaramillo & Angela Restrepo Referencia : Mycopathologia. 1986 Jun;94(3):133-44. DOI (Digital Object Identifier) : 10.1007/BF00454591 PMID : 3762654 En línea : https://link.springer.com/article/10.1007%2FBF00454591 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4338 Pathogenesis of paracoccidioidomycosis: A histopathological study of the experimental murine infection [documento electrónico] / Víctor Bedoya M., ; Juan Guillermo McEwen Ochoa, ; Ángela María Tabares Velásquez, ; Fabio Uribe Jaramillo, ; Ángela Restrepo Moreno, . - 1986.
Obra : Mycopathologia
Idioma : Inglés (eng)
Resumen : The pathogenesis of primary pulmonary P. brasiliensis infection, the systemic dissemination which followed, and the histopathology of the main organs involved was studied in a murine model of chronic paracoccidioidomycosis. Adult male BALB/C mice, were challenged intranasally with 26×10−6 viable P. brasiliensis yeast cells. We inoculated 86 animals which were sacrificed from 0 h to 20 weeks. As controls, 11 mice were instilled with saline solution, and 48 with 26×10−6 heat-killed. P. brasiliensis yeast cells. None of the animals receiving saline, exhibited pathologic alterations; 11.6% of those inoculated with the heatkilled cells, revealed mild, transitory acinopulmonary neutrophilic infiltrates. The animals infected with viable cells, developed a systemic process affecting mainly the lungs (46.5%), liver (18.6%), lymphnodes (18.6%), and spleen (3.5%). In this group of animals, lung lesions were detected regularly at all time periods from 3 h to 20 weeks. A multiple bronchoneumonic process was initially observed at 6 h, reached its maximum intensity around the third day, subsided thereafter but did not disappear and reactivated after the fifth week to become stationary until the end of experiments. Dissemination to other organs occurred early, and apparently by the hematogenous route. Initially the inflammatory cell infiltrate was mainly neutrophilic. With time, these cells were gradually replaced by lymphocytes, histiocytes and plasmocytes. Granuloma configuration of the cell infiltrate was distinctly seen around the fifth week, with multinucleated giant cells appearing at the ninth week. Hiliary lymphnode involvement was rare (7%) and primary lung lesions, as seen in tuberculosis and histoplasmosis, were not observed. Mención de responsabilidad : Víctor Bedoya, Juan G. McEwen, Angela M. Tabares, Fabio Uribe Jaramillo & Angela Restrepo Referencia : Mycopathologia. 1986 Jun;94(3):133-44. DOI (Digital Object Identifier) : 10.1007/BF00454591 PMID : 3762654 En línea : https://link.springer.com/article/10.1007%2FBF00454591 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4338 Reserva
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Código de barras Número de Ubicación Tipo de medio Ubicación Sección Estado DD000839 AC-1986-005 Archivo digital Producción Científica Artículos científicos Disponible
Título : Chronic murine paracoccidioidomycosis: Effect of ketoconazole on clearance of paracoccidioides brasiliensis and immune response Tipo de documento : documento electrónico Autores : Guillermo L. Hoyos, ; Juan Guillermo McEwen Ochoa, ; Ángela Restrepo Moreno, Fecha de publicación : 1984 Títulos uniformes : Journal of Medical and Veterinary Mycology Idioma : Inglés (eng) Resumen : In a murine model of chronic pulmonary and disseminated paracoccidioidomycosis, ketoconazole (100 mg kg-1 in 0–3% agar) given by gavage twice daily for 1 or 2 months enabled all mice to clear disseminated Paracoccidioides brasiliensis from the spleen. Clearance of P. brasiliensis from the lungs was more difficult, and was achieved in 60% of the mice treated for 2 months. Sera from agar-treated control mice at days 77 and 103 post-infection demonstrated precipitating antibodies to P. brasiliensis antigens, but sera from ketoconazole-treated mice were precipitin-negative, indicating a favorable prognosis. Delayed hypersensitivity reactions to P. brasiliensis antigens in ketoconazole-treated mice were not significantly greater than in controls; consequently this test correlated less well with response than levels of serum antibody. This is the first use of this animal model of paracoccidioidomycosis to study the effect of antifungal drug protocols on the resolution of the disease. It also demonstrates the utility of this model in addressing clinically relevant questions about this disease and its treatment. Mención de responsabilidad : Guillermo L. Hoyos, Juan G. McEwen, Elmer Brummer, Elizabeth Castañeda, Angela Restrepo, David A. Stevens Referencia : Sabouraudia. 1984;22(5):419-26. DOI (Digital Object Identifier) : 10.1080/00362178485380671 PMID : 6095472 En línea : https://academic.oup.com/mmy/article-abstract/22/5/419/1628665 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4330 Chronic murine paracoccidioidomycosis: Effect of ketoconazole on clearance of paracoccidioides brasiliensis and immune response [documento electrónico] / Guillermo L. Hoyos, ; Juan Guillermo McEwen Ochoa, ; Ángela Restrepo Moreno, . - 1984.
Obra : Journal of Medical and Veterinary Mycology
Idioma : Inglés (eng)
Resumen : In a murine model of chronic pulmonary and disseminated paracoccidioidomycosis, ketoconazole (100 mg kg-1 in 0–3% agar) given by gavage twice daily for 1 or 2 months enabled all mice to clear disseminated Paracoccidioides brasiliensis from the spleen. Clearance of P. brasiliensis from the lungs was more difficult, and was achieved in 60% of the mice treated for 2 months. Sera from agar-treated control mice at days 77 and 103 post-infection demonstrated precipitating antibodies to P. brasiliensis antigens, but sera from ketoconazole-treated mice were precipitin-negative, indicating a favorable prognosis. Delayed hypersensitivity reactions to P. brasiliensis antigens in ketoconazole-treated mice were not significantly greater than in controls; consequently this test correlated less well with response than levels of serum antibody. This is the first use of this animal model of paracoccidioidomycosis to study the effect of antifungal drug protocols on the resolution of the disease. It also demonstrates the utility of this model in addressing clinically relevant questions about this disease and its treatment. Mención de responsabilidad : Guillermo L. Hoyos, Juan G. McEwen, Elmer Brummer, Elizabeth Castañeda, Angela Restrepo, David A. Stevens Referencia : Sabouraudia. 1984;22(5):419-26. DOI (Digital Object Identifier) : 10.1080/00362178485380671 PMID : 6095472 En línea : https://academic.oup.com/mmy/article-abstract/22/5/419/1628665 Enlace permanente : https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=4330 Reserva
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Código de barras Número de Ubicación Tipo de medio Ubicación Sección Estado DD000831 AC-1984-004 Archivo digital Producción Científica Artículos científicos Disponible
