Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros

Tipo de estudio
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Mem Inst Oswaldo Cruz ; 110(1): 145-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25742276

RESUMEN

Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition.


Asunto(s)
Parasitosis Intestinales/diagnóstico , Momias/parasitología , Tricuriasis/diagnóstico , Trichuris/aislamiento & purificación , Animales , Brasil , Historia del Siglo XVIII , Historia del Siglo XIX , Humanos , Recto/parasitología , Síndrome , Trichuris/ultraestructura
2.
Mem Inst Oswaldo Cruz ; 105(7): 938-41, 2010 11.
Artículo en Inglés | MEDLINE | ID: mdl-21120369

RESUMEN

The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.


Asunto(s)
Angiostrongylus cantonensis/aislamiento & purificación , Vectores de Enfermedades , Gastrópodos/parasitología , Angiostrongylus cantonensis/anatomía & histología , Angiostrongylus cantonensis/clasificación , Animales , Brasil , Femenino , Masculino , Meningoencefalitis/parasitología , Meningoencefalitis/transmisión , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/transmisión
3.
Free Radic Biol Med ; 108: 183-191, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28363600

RESUMEN

Trypanosoma cruzi is the causative agent of Chagas disease and has a single mitochondrion, an organelle responsible for ATP production and the main site for the formation of reactive oxygen species (ROS). T. cruzi is an obligate intracellular parasite with a complex life cycle that alternates between vertebrate and invertebrate hosts, therefore the development of survival strategies and morphogenetic adaptations to deal with the various environments is mandatory. Over the years our group has been studying the vector-parasite interactions using heme as a physiological oxidant molecule that triggered epimastigote proliferation however, the source of ROS induced by heme remained unknown. In the present study we demonstrate the involvement of heme in the parasite mitochondrial metabolism, decreasing oxygen consumption leading to increased mitochondrial ROS and membrane potential. First, we incubated epimastigotes with carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), an uncoupler of oxidative phosphorylation, which led to decreased ROS formation and parasite proliferation, even in the presence of heme, correlating mitochondrial ROS and T. cruzi survival. This hypothesis was confirmed after the mitochondria-targeted antioxidant ((2-(2,2,6,6 Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (MitoTEMPO) decreased both heme-induced ROS and epimastigote proliferation. Furthermore, heme increased the percentage of tetramethylrhodamine methyl ester (TMRM) positive parasites tremendously-indicating the hyperpolarization and increase of potential of the mitochondrial membrane (ΔΨm). Assessing the mitochondrial functional metabolism, we observed that in comparison to untreated parasites, heme-treated epimastigotes decreased their oxygen consumption, and increased the complex II-III activity. These changes allowed the electron flow into the electron transport system, even though the complex IV (cytochrome c oxidase) activity decreased significantly, showing that heme-induced mitochondrial ROS appears to be a consequence of the enhanced mitochondrial physiological modulation. Finally, the parasites that were submitted to high concentrations of heme presented no alterations in the ultrastructure. Consequently, our results suggest that heme released by the insect vector after the blood meal, modify epimastigote mitochondrial physiology to increase ROS as a metabolic mechanism to maintain epimastigote survival and proliferation.


Asunto(s)
Enfermedad de Chagas/inmunología , Hemo/metabolismo , Mitocondrias/metabolismo , Trypanosoma cruzi/fisiología , Animales , Carbonil Cianuro p-Trifluorometoxifenil Hidrazona/metabolismo , Procesos de Crecimiento Celular , Células Cultivadas , Transporte de Electrón , Complejo IV de Transporte de Electrones/metabolismo , Metabolismo Energético , Humanos , Estadios del Ciclo de Vida , Potencial de la Membrana Mitocondrial , Compuestos Organofosforados/metabolismo , Consumo de Oxígeno , Piperidinas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Rodaminas/metabolismo
4.
Vet Parasitol ; 176(2-3): 226-35, 2011 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-21109353

RESUMEN

Trichuris thrichomysi n. sp., recovered from the cecum of the wild rodent Thrichomys apereoides from a transition zone between the Atlantic Forest and Cerrado morfoclimatic domains, and its life cycle observed under experimental conditions are described. This new species is closely related to Trichuris travassosi, Trichuris chiliensis and Trichuris fulvi, but can be distinguished from them mainly by differences in the posterior end of males. Details of the surface such as the bacillary gland, cuticular inflations and several morphological details obtained by scanning electron microscopy and field emission scanning electron microscopy confirmed the characteristics that differentiate the new species. The histopathology of the intestinal wall of naturally infected rodents is also reported. The present study extends the geographical distribution of T. thrichomysi n. sp to the Pantanal ecosystem and reports a new host, Thrichomys pachiurus.


Asunto(s)
Enfermedades de los Roedores/parasitología , Roedores/parasitología , Tricuriasis/veterinaria , Trichuris/anatomía & histología , Trichuris/clasificación , Animales , Brasil/epidemiología , Femenino , Masculino , Enfermedades de los Roedores/epidemiología , Especificidad de la Especie , Tricuriasis/epidemiología , Tricuriasis/parasitología
5.
Mem. Inst. Oswaldo Cruz ; 110(1): 145-147, 03/02/2015. graf
Artículo en Inglés | LILACS | ID: lil-741613

RESUMEN

Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition.


Asunto(s)
Animales , Femenino , Masculino , Ratones , Suplementos Dietéticos , Diabetes Mellitus Experimental/dietoterapia , Hiperglucemia/prevención & control , Hipoglucemiantes/uso terapéutico , Liriope (Planta)/química , Tubérculos de la Planta/química , Polisacáridos/uso terapéutico , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Suplementos Dietéticos/efectos adversos , Etnofarmacología , Regulación Enzimológica de la Expresión Génica , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/aislamiento & purificación , Resistencia a la Insulina , Glucógeno Hepático/metabolismo , Hígado/enzimología , Hígado/metabolismo , Hígado/patología , Medicina Tradicional China , Páncreas/metabolismo , Páncreas/patología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/efectos adversos , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Polisacáridos/administración & dosificación , Polisacáridos/efectos adversos , Polisacáridos/aislamiento & purificación , Distribución Aleatoria , Ratas Wistar , Pruebas de Toxicidad Aguda
6.
Mem. Inst. Oswaldo Cruz ; 105(7): 938-941, Nov. 2010. ilus, tab
Artículo en Inglés | LILACS | ID: lil-566189

RESUMEN

The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.


Asunto(s)
Animales , Femenino , Masculino , Angiostrongylus cantonensis , Vectores de Enfermedades , Gastrópodos , Angiostrongylus cantonensis , Angiostrongylus cantonensis , Brasil , Meningoencefalitis , Meningoencefalitis/transmisión , Infecciones por Strongylida , Infecciones por Strongylida/transmisión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA