Consulta: subjectFacets:"Trypanosoma cruzi"
Registros recuperados: 95
Data/hora: 06/06/2024 03:41:08

RNA-binding proteins and their role in the regulation of gene expression in Trypanosoma cruzi and Saccharomyces cerevisiae
Provedor de dados: 74
Autores: Oliveira,Camila; Faoro,Helisson; Alves,Lysangela Ronalte; Goldenberg,Samuel.
Abstract RNA-binding proteins (RBPs) have important functions in the regulation of gene expression. RBPs play key roles in post-transcriptional processes in all eukaryotes, such as splicing regulation, mRNA transport and modulation of mRNA translation and decay. RBPs assemble into different mRNA-protein complexes, which form messenger ribonucleoprotein complexes (mRNPs). Gene expression regulation in trypanosomatids occurs mainly at the post-transcriptional level and RBPs play a key role in all processes. However, the functional characterization of RBPs in Trypanosoma cruzi has been impaired due to the lack of reliable reverse genetic manipulation tools. The comparison of RBPs from Saccharomyces cerevisiae and T. cruzi might allow inferring on the function...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: RNA-binding proteins; Trypanosoma cruzi; Saccharomyces cerevisiae; Gene expression regulation.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572017000100022

Trypanosomatid comparative genomics: contributions to the study of parasite biology and different parasitic diseases
Provedor de dados: 74
Autores: Teixeira,Santuza M.; Paiva,Rita Márcia Cardoso de; Kangussu-Marcolino,Monica M.; DaRocha,Wanderson D.
In 2005, draft sequences of the genomes of Trypanosoma brucei, Trypanosoma cruzi and Leishmania major, also known as the Tri-Tryp genomes, were published. These protozoan parasites are the causative agents of three distinct insect-borne diseases, namely sleeping sickness, Chagas disease and leishmaniasis, all with a worldwide distribution. Despite the large estimated evolutionary distance among them, a conserved core of ~6,200 trypanosomatid genes was found among the Tri-Tryp genomes. Extensive analysis of these genomic sequences has greatly increased our understanding of the biology of these parasites and their host-parasite interactions. In this article, we review the recent advances in the comparative genomics of these three species. This analysis also...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma brucei; Trypanosoma cruzi; Leishmania major; Genome; RNAseq.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100001

DNA lesions and repair in trypanosomatids infection
Provedor de dados: 74
Autores: Repolês,Bruno M.; Machado,Carlos Renato; Florentino,Pilar T.V.
Abstract Pathological processes such as bacterial, viral and parasitic infections can generate a plethora of responses such as, but not restricted to, oxidative stress that can be harmful to the host and the pathogen. This stress occurs when there is an imbalance between reactive oxygen species produced and antioxidant factors produced in response to the infection. This imbalance can lead to DNA lesions in both infected cells as well as in the pathogen. The effects of the host response on the parasite lead to several kinds of DNA damage, causing alterations in the parasite’s metabolism; the reaction and sensitivity of the parasite to these responses are related to the DNA metabolism and life cycle of each parasite. The present review will discuss the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Reactive oxygen species; DNA repair.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000200311

Morfometría de la Parótida de Ratón Infectado por la Cepa RAL de Trypanosoma cruzi en Función del Sexo
Provedor de dados: 77
Autores: Albuquerque,Sergio de; Lopes,Ruberval Armando; Sala,Miguel Angel; Abraháo,Ana Amelia Carraro; Ribeiro,Rosa Domingues.
Fueron estudiadas las alteraciones y el nivel de deterioro de las parótidas de animales infectados con la cepa RAL de Trypanosoma cruzi. Se utilizaron ratones albinos (Mus musculus) de ambos sexos, debido al dimorfismo sexual de las glándulas salivares, inoculados con 2 x 10(4) tripomastigotes sanguíneos de la cepa RAL del T. cruzi. Los animales fueron sacrificados al 12° día de infección, coincidiendo con el pico parasitémico. La parótida fue procesada histológicamente y, posteriormente, evaluada histopatológica y morfometricamente. Los resultados permitieron verificar intenso parasitismo en la glándula, la que presentó desorganización estructural y atrofia generalizada de acinos y conductos, más intensos en las hembras. Concluyendo, la cepa RAL del T....
Tipo: Journal article
Palavras-chave: Trypanosoma cruzi; Cepa RAL; Ratón; Parótida; Histopatología; Morfometría.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022007000200004

Estudio Morfométrico del Hígado de Ratón en la Enfermedad de Chagas Experimental
Provedor de dados: 77
Autores: Ragonha,Louise Helena Olhan; Abrahão,Ana Amélia Carraro; Sala,Miguel Angel; Lopes,Ruberval A.; Ribeiro,Rosa Domingues; Prado Jr.,José Clovis do; Albuquerque,Sérgio de; Zucoloto,Sérgio.
El objetivo de este trabajo fue caracterizar histopatológicamente y morfométricamente las alteraciones del tejido hepático de ratón, durante la fase aguda de la infección por la cepa MORC-2 de Trypanosoma cruzi. Esta cepa mostró acentuado tropismo por el hígado, con numerosos nidos de amastigotes en los cortes examinados. El hígado de los animales infectados estaba constituido por células menores, con citoplasma granuloso. En algunas áreas, los sinusoides estaban congestionados y las células de Kupffer hipertróficas e hiperplásicas. El tejido hepático mostró focos circunscritos de células inflamatorias en áreas de necrosis, sinusoides, en torno de las venas centrolobulillares y de los espacios porta. La vena centrolobulillar estaba dilatada y...
Tipo: Journal article
Palavras-chave: Morfometría; Histopatología; Hígado; Ratón; Trypanosoma cruzi; Cepa MORC-2.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022006000400015

Estudio Cariométrico de Placentas de Ratones con Infección Aguda por Diferentes Cepas de Trypanosoma cruzi
Provedor de dados: 77
Autores: Sala,Miguel Ángel; Lopes,Ruberval Armando; Abrahão,Ana Amelia Carraro; Meneguette,Cicero; Albuquerque,Sérgio de; Ribeiro,Rosa Domingues.
El objetivo de este trabajo fue evaluar cariometricamente las alteraciones causadas por diferentes cepas de T. cruzi en la placenta del ratón. Ratones hembras de 60 días, grávidas, fueron inoculadas, intraperitonealmente, con 2 x 10(5) tripomastigotes sanguíneos de las cepas colombiana, Y, Solivia o RC del T. cruzi. Fueron observadas claras diferencias en las alteraciones cariométricas de las células trofoblásticas gigantes y de las células trofoblásticas de la zona esponjosa. Los resultados demostraron que las cepas colombiana y RC causan alteraciones tanto en las células trofoblásticas gigantes como en las células del trofoblasto esponjoso, mientras que las cepas Y y Bolivia provocan alteraciones solamente en las células trofoblásticas gigantes. Es...
Tipo: Journal article
Palavras-chave: Enfermedad de Chagas Experimental; Trypanosoma cruzi; Ratón; Placenta; Cariometría.
Ano: 2008
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022008000300018

Ergosterol isolated from the basidiomycete Pleurotus salmoneostramineus affects Trypanosoma cruzi plasma membrane and mitochondria
Provedor de dados: 80
Autores: Alexandre,Tatiana Rodrigues; Lima,Marta Lopes; Galuppo,Mariana Kolos; Mesquita,Juliana Tonini; Nascimento,Matilia Ana do; Santos,Augusto Leonardo dos; Sartorelli,Patricia; Pimenta,Daniel Carvalho; Tempone,Andre Gustavo.
Abstract  Background  Major drawbacks of the available treatment against Chagas disease (American trypanosomiasis) include its toxicity and therapeutic inefficiency in the chronic phase of the infection, which makes it a concern among neglected diseases. Therefore, the discovery of alternative drugs for treating chronic Chagas disease requires immediate action. In this work, we evaluated the mushroom Pleurotus salmoneostramineus in the search for potential antiparasitic compounds.  Methods  Fruit bodies of the basidiomycete Pleurotus salmoneostramineus were triturated and submitted to organic solvent extraction. After liquid-liquid partition of the crude extract, three fractions were obtained and the bioguided fractionation study was conducted to isolate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pleurotus salmoneostramineus; Ergosterol; Trypanosoma cruzi; Mechanism of action.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100313

Efficacy of sertraline against Trypanosoma cruzi: an in vitro and in silico study
Provedor de dados: 80
Autores: Ferreira,Daiane Dias; Mesquita,Juliana Tonini; Silva,Thais Alves da Costa; Romanelli,Maiara Maria; Batista,Denise da Gama Jaen; Silva,Cristiane França da; Gama,Aline Nefertiti Silva da; Neves,Bruno Junior; Melo-Filho,Cleber Camilo; Soeiro,Maria de Nazare Correia; Andrade,Carolina Horta; Tempone,Andre Gustavo.
Abstract  Background: Drug repurposing has been an interesting and cost-effective approach, especially for neglected diseases, such as Chagas disease.  Methods: In this work, we studied the activity of the antidepressant drug sertraline against Trypanosoma cruzi trypomastigotes and intracellular amastigotes of the Y and Tulahuen strains, and investigated its action mode using cell biology and in silico approaches.  Results: Sertraline demonstrated in vitro efficacy against intracellular amastigotes of both T. cruzi strains inside different host cells, including cardiomyocytes, with IC50 values between 1 to 10 μM, and activity against bloodstream trypomastigotes, with IC50 of 14 μM. Considering the mammalian cytotoxicity, the drug resulted in a selectivity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Drug; Treatment; Sertraline; Drug repurposing; Drug repositioning.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992018000100321

American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico
Provedor de dados: 80
Autores: Jiménez-Coello,Matilde; Acosta-Viana,Karla; Guzmán-Marín,Eugenia; Bárcenas-Irabién,Alejandra; Ortega-Pacheco,Antonio.
AbstractBackground The American trypanosomiasis is a zoonosis caused by the protozoaTrypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico.Methods A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 %...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Epidemiology; Owned dogs; Major city; Mexico.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992015000100343

Impact of autologous whole blood administration upon experimental mouse models of acute Trypanosoma cruzi infection
Provedor de dados: 80
Autores: Pavão,Beatriz Philot; Demarque,Kelly Cristina; Batista,Marcos Meuser; Oliveira,Gabriel Melo de; Silva,Cristiane França da; Silva,Francisca Hildemagna Guedes da; Caputo,Luzia Fátima Gonçalves; Cascabulho,Cynthia Machado; Barcinski,Marcello André; Soeiro,Maria de Nazaré Correia.
Abstract  Background: Autologous whole blood (AWB) administration is described as alternative/complementary medical practice widely employed in medical and veterinary therapy against infections, chronic pathologies and neoplasias. Our aim is to investigate in vivo biological effect of AWB using healthy murine models under the course of Trypanosoma cruzi acute infection.  Methods: The first set of studies consisted of injecting different volumes of AWB and saline (SAL) into the posterior region of quadriceps muscle of healthy male Swiss mice under distinct therapeutic schemes evaluating: animal behavior, body and organ weight, hemogram, plasmatic biochemical markers for tissue damage and inflammatory cytokine levels and profile. To assess the impact on the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Autologous blood; Alternative therapy; Mouse models; Trypanosoma cruzi.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992018000100316

Antileishmanial and antitrypanosomal activity of the cutaneous secretion of Siphonops annulatus
Provedor de dados: 80
Autores: Pinto,Erika Gracielle; Antoniazzi,Marta Maria; Jared,Carlos; Tempone,and Andre Gustavo.
Background Among the tropical parasitic diseases, those caused by protozoans are considered a challenge to public health, being represented by leishmaniasis and Chagas disease. In view of the low effectiveness and toxicity of the current therapy, animal venoms such as amphibian secretions have been used as a promising source of new drug prototypes. The present work aimed to achieve bioguided fractionation of metabolites present in a cutaneous secretion of the caecilian Siphonops annulatus (Amphibia: Gymnophiona: Siphonopidae) with antileishmanial and antitrypanosomal activity.Methods Through liquid-liquid partition and chromatographic techniques, the secretion was fractionated using bioguided assays. The 50% inhibitory concentration (IC50) of the main...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amphibians; Venoms; Leishmania; Trypanosoma cruzi; Therapy; Drugs.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992014000200340

Canine trypanosomiasis: etiology of infection and implications for public health
Provedor de dados: 80
Autores: Eloy,LJ; Lucheis,SB.
Canine trypanosomiasis, caused by protozoans of the genus Trypanosoma, is divided into two primary types: the American form (Chagas disease), due to Trypanosoma cruzi infection, and the African form (sleeping sickness or surra), provoked by Trypanosomaevansi. This disease was originally enzootic and affected only wild animals, including mammals and birds, which served as reservoirs. Later, it spread to domestic animals such as horses, cattle and dogs. The disease became a zoonosis when contact between rural inhabitants and natural Trypanosoma foci occurred, due to ecological imbalances and increasing migration. Dogs are significantly involved in this context, because they are the main domestic animals and participate in the transmission and maintenance...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Canine trypanosomiasis; Trypanosoma cruzi; Trypanosoma evansi; Chagas disease; Surra.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992009000400002

Using prodigiosin against some gram-positive and gram-negative bacteria and Trypanosoma cruzi
Provedor de dados: 80
Autores: Herráez,Rocío; Mur,Anna; Merlos,Alexandra; Viñas,Miguel; Vinuesa,Teresa.
Abstract  Background: This work aimed to explore the action of natural prodigiosin on both bacterial organisms and Trypanosoma cruzi cells.  Methods: Natural prodigiosin pigment was extracted and purified from cultures of Serratia marcescens. Two media, peanut broth and peptone glycerol broth, both recommended in the literature for prodigiosin production, were compared. The prodigiosin obtained was employed to explore its antimicrobial properties against both bacteria and Trypanosoma cruzi cells.  Results: Peanut broth yielded four times more prodigiosin. The prodigiosin showed remarkable activity (minimal inhibitory concentrations in the range of 2-8 µM for bacteria and half maximal inhibitory concentration of 0.6 µM for Trypanosoma cruzi). In fact, the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Chagas disease; Prodigiosin; Atomic force microscopy.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992019000100314

Benznidazole affects expression of Th1, Th17 and Treg cytokines during acute experimental Trypanosoma cruzi infection
Provedor de dados: 80
Autores: Gatto,Mariana; Oliveira,Larissa Ragozo Cardoso; Dias,Fernanda De Nuzzi; Araújo Júnior,João Pessoa; Lima,Carlos Roberto Gonçalves; Lordelo,Eliana Peresi; Santos,Rodrigo Mattos dos; Kurokawa,Cilmery Suemi.
Abstract  Background The present study evaluated the effect of treatment with benznidazole on mRNA expression of IFN-γ, IL-17, IL-10, TGF-β and FoxP3 in spleen and heart tissue of BALB/c mice in the acute phase of an experimental infection with Trypanosoma cruzi, strains JLP or Y.  Methods The mRNA expression of cytokines and parasite load were assessed by q-PCR. Dependent groups were compared using Student's paired t-test and independent groups were compared using Student's unpaired t-test.  Results Infection with the JLP or Y strains increased expression of IFN-γ in the heart and of IL-10 and IL-17 in the spleen and heart compared to uninfected animals. Treatment increased the expression of IFN-γ and decreased the expression of IL-17, IL-10, TGF- β and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chagas disease; Trypanosoma cruzi; Immune response; Cytokines; Q-PCR.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100320

Organ tropism during the acute and chronic phases of Trypanosoma cruzi infection in BALB/c mice
Provedor de dados: 80
Autores: Oliveira,LRC; Picka,MCM; Nicolete,VC; Calvi,SA; Marcondes-Machado,J.
The aim of the present study was to investigate the presence of Trypanosoma cruzi in the heart, liver, lung, and kidneys, using hemoculture and PCR analysis, of mice infected with different parasite strains during the acute and chronic phases of infection. Parasitemia curves revealed strain-specific biological behaviors. For the Y and JLP strains, the acute phase of infection started at days six and ten post-infection, parasitemia peaked at days seven and 15 post-infection, the chronic phase started at days nine and 28 post-infection, and animals started dying at days 19 and 120 post-infection, respectively. When the two strains were compared, the JLP strain exhibited reduced and slower replication rates associated with a delayed peak of parasitism and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; PCR; Hemoculture; Organs; Distribution.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992012000100005

Trypanosomatids in dogs belonging to individuals with chronic Chagas’ disease living in Botucatu town and surrounding region, São Paulo State, Brazil
Provedor de dados: 80
Autores: Lucheis,S. B.; Da Silva,A. V.; Araújo Jr,J. P.; Langoni,H.; Meira,D. A.; Marcondes-Machado,J.
Among domestic animals, dogs are considered to be the major reservoirs of trypanosomatids and, due to their proximity to man, the presence of these parasites in dogs is an alert to actions aiming at triatomine control. Fifty dogs (26 males and 24 females), aged from 2 months to 15 years, belonging to 30 chronic Chagas’ disease individuals from 15 different municipalities in the western region of São Paulo State, Brazil, were subjected to blood collection for the following tests: artificial xenodiagnosis, blood culture, and Polymerase Chain Reaction (PCR). Forty-three (86%) out of 50 dogs were positive to at least one of the tests performed; 34 (68%) were positive to xenodiagnosis, 30 (60%) to blood culture, and 25 (50%) to PCR for T. cruzi and/or T....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; T. rangeli; Dog; Xenodiagnosis; Blood culture; Polymerase chain reaction.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000400009

Triatominae (Hemiptera: Reduviidae): Systematic questions and some others
Provedor de dados: 82
Autores: Schaefer,Carl W.
The Neotropical Chagas' disease vectors are classified as members of the reduviid subfamily Triatominae. However, this classification has been suggested to be incorrect, and the suggestion has been treated as fact by some authors; the suggestion is that some (all?) groups in Triatominae had different nontriatomine reduviid ancestors. In this article I raise this question explicitly and ask other questions ancillary to it. I do not answer these questions. Of particular interest is the systematic position of Linshcosteus, the only genus of Triatominae all of whose species occur outside the New World (in India). Related to this question is that of the origin(s) of the several species and populations probably derived from the tropicopolitan Triatoma...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insecta; Chagas' disease; Trypanosoma cruzi; Rhodnius; Linshcosteus; Cladistics.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2003000100001

Characterization of the Fibronectin Binding Properties of Typanosoma cruzi  Epimastigotes
Provedor de dados: 19
Autores: Cox, Dermot; Uga, Shoji; Motoyama, Yukio; Yoshida, Keizo.
Palavras-chave: Trypanosoma cruzi; Epimastigotes; Fibronectin binding; RGDS(Arg-Gly-Asp-Ser).
Ano: 1992
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/176

Quantitative Determination of Growth of Amastigotes and Trypomastigotes in an In Vitro Cultivation System of HeLa Cells Infected with Trypanosoma cruzi
Provedor de dados: 19
Autores: Nakajima-Shimada, Junko; Hirota, Yumiko; Kaneda, Yoshimasa; Aoki, Takashi.
Palavras-chave: Trypanosoma cruzi; HeLa cells; In vitro infection; Quantitative growth determination.
Ano: 1994
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/200

Chemical composition, anti-Trypanosoma cruzi and cytotoxic activities of the essential oil from green fruits of Protium ovatum (BURSERACEAE)
Provedor de dados: 94
Autores: Estevam,Elisângela Barbosa Borges; Alves,Cássia Cristina Fernandes; Esperandim,Viviane Rodrigues; Cazal,Cristiane de Melo; Souza,Alex Fonseca; Miranda,Mayker Lazaro Dantas.
Abstract  Chagas disease is a major neglected tropical disease caused by Trypanosoma cruzi. It has been treated with the antiparasitic drugs nifurtimox and benzonidazole, which cause several side effects. The market for natural products has considerably grown lately and the use of plants has become an alternative to the development of novel drugs to cure the disease. Therefore, this study aimed at describing the chemical analysis of the essential oil from green fruits of Protium ovatum and evaluating their trypanocidal and cytotoxic potential. The essential oil was obtained by Clevenger hydrodistillation whereas its chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS). The major compounds found in the essential oil...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Protium ovatum; SS-myrcene; Fruits; Essential oil; Trypanosoma cruzi; Cytotoxic analysis.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452018000106001

Enfermedad de Chagas en poblaciones prehistóricas del norte de Chile
Provedor de dados: 97
Autores: ORELLANA-HALKYER,NANCY; ARRIAZA-TORRES,BERNARDO.
La enfermedad de Chagas es producida por el parásito Trypanosoma cruzi, el cual afecta tanto a seres humanos como a animales, en particular mamíferos marsupiales y placentarios. Las vías de transmisión son diversas, siendo una de las más importantes la vía vectorial, en la que participan insectos infectados con este parásito, animales y humanos. En este artículo de revisión discutimos los postulados sobre la vía de transmisión oral, los hallazgos de T. cruzi en momias de América y especialmente en las del norte de Chile. Presentamos además información que apunta a que la enfermedad de Chagas estuvo presente mucho antes de la conquista europea y de la construcción de viviendas de adobe. Comentamos las hipótesis sobre el vector domiciliado más importante de...
Tipo: Journal article
Palavras-chave: Enfermedad de Chagas; Norte de Chile; Triatominos; Trypanosoma cruzi; Zooarqueología.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2010000400007

La inoculación de Lactobacillus casei en ratones NIH induce una respuesta protectora contra la infección por Trypanosoma cruzi (cepa Ninoa)
Provedor de dados: 108
Autores: Bautista Garfias,Carlos Ramón; Torres Álvarez,María del Carmen; Martínez Gómez,Federico.
El objetivo del presente estudio fue evaluar el efecto de Lactobacillus casei administrado por vía oral o intraperitoneal a ratones NIH, en la infección experimental con Trypanosoma cruzi cepa Ninoa. Se distribuyeron al azar 23 ratones NIH en tres grupos, los cuales fueron tratados siete días antes de la infección con 12 x 10(4) Trypanosoma cruzi, cepa Ninoa. Los animales en el grupo testigo (n = 7) recibieron solución salina estéril por vía intraperitoneal (ip); los del grupo Lc-O (n = 8), Lactobacillus casei vía oral, y los del grupo Lc-IP (n = 8) recibieron L. casei vía ip. Los ratones tratados con lactobacilos mostraron un número reducido de parásitos sanguíneos después de la confrontación, en comparación con el grupo testigo (P &lt; 0.01). A su vez,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Lactobacillus casei; Adyuvante; Resistencia.
Ano: 2008
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0301-50922008000200003

DETECCIÓN DE INFECCIÓN NATURAL POR Trypanosoma cruzi (TRYPANOSOMATIDAE) EN TRIATOMINOS DEL MUNICIPIO DE COLOSÓ, COLOMBIA
Provedor de dados: 37
Autores: AYALA HOYOS,Carolina Julieth; HERNÁNDEZ MENDOZA,Carlos Mario; EYES ESCALANTE,Melissa; ROMERO RICARDO,Luis Roberto; ÁLVAREZ RODRÍGUEZ,Rafael Andrés; BLANCO TUIRÁN,Pedro.
RESUMEN El reporte de triatominos infectados por Trypanosoma cruzi en un área silvestre del municipio de Colosó, hizo necesario determinar las especies de vectores en cercanía a las viviendas de la vereda Jorro, por ser el asentamiento rural próximo al hallazgo. En la presente nota, se informa por primera vez para el municipio la presencia de especies de triatominos de importancia epidemiológica con un alto porcentaje de infección por el parásito, además, de ampliar la distribución de estos vectores en el departamento de Sucre. Para ello, se realizaron capturas de los insectos en 13 viviendas por búsqueda activa, vigilancia comunitaria y trampas de luz. La determinación de la infección natural se llevó a cabo por observación directa al microscopio y...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Colosó; Enfermedad de Chagas; Infección; Triatominos; Trypanosoma cruzi; Vectores.
Ano: 2019
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2019000100180

INFECCIÓN NATURAL POR Trypanosoma cruzi (TRYPANOSOMATIDAE) EN TRIATOMINOS INTRADOMÉSTICOS DEL DEPARTAMENTO DE GUAINÍA
Provedor de dados: 37
Autores: SOLÍS-MEDINA,Cesil; ZULUAGA AGUIRRE,Sara; TRIANA-CHAVEZ,Omar; CANTILLO-BARRAZA,Omar.
RESUMEN La búsqueda continua de triatominos forma parte de los programas de vigilancia de la enfermedad de Chagas en zonas con características ecológicas apropiadas para la presencia del vector, permitiendo priorizar y definir las acciones de intervención. El objetivo del presente trabajo fue determinar la presencia y estado de infección de triatominos en viviendas del municipio de Inírida (Guainía). El estudio se realizó entre 2018 y 2019 mediante vigilancia comunitaria y búsqueda activa. Los vectores se identificaron y evaluaron por PCR. Se recolectaron cinco triatominos (un Panstrongylus lignarius y cuatro P. geniculatus). Se evidenció la infección natural en ambas especies. La genotipificación mostró la presencia de TcI Dom. Se actualiza así la...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enfermedad de Chagas; Panstrongylus geniculatus; Panstrongylus lignarius; Triatominos; Trypanosoma cruzi.
Ano: 2021
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2021000100127

Prevalencia de infección por Trypanosoma cruzi en escolares de Salta y Chaco, Argentina
Provedor de dados: 38
Autores: Sánchez Negrette,Olga; Zaidenberg,Mario; Monteros,María Concepción; Acevedo,Analía; Linares,Víctor; Freilij,Héctor.
El objetivo del trabajo consistió en identificar la seroprevalencia de la infección por Trypanosoma cruzi en niños en edad escolar en localidades de las provincias de Salta y Chaco. Se trabajó en 44 escuelas de la ciudad de Salta, en parajes de San Carlos; en 10 escuelas de La Unión y en 7 escuelas de Taco Pozo. El trabajo tiene un diseño de corte transversal. La toma de muestra se realizó por punción capilar con equipos Serokit, y la confirmación de los casos seropositivos o dudosos por punción venosa, y obtención de suero, para realizar HAI y ELISA. Los casos seropositivos confirmados fueron tratados con Benznidazol® durante 60 días en dosis de 5-7mg/kg/ día. Para el análisis estadístico se elaboraron tablas con frecuencias absolutas y relativas. Se...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Seroprevalencia; Trypanosoma cruzi; Escolares; Salta; Chaco; Vectores.
Ano: 2017
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-29572017000400016

Metabolismo del hemo: las dos caras de los efectos de la acumulación de precursores y porfirinas
Provedor de dados: 38
Autores: Rossetti,María Victoria; Buzaleh,Ana María; Parera,Victoria Estela; Fukuda,Haydée; Lombardo,María Elisa; Lavandera,Jimena; Gerez,Esther Noemí; Melito,Viviana Alicia; Zuccoli,Johanna Romina; Ruspini,Silvina Fernanda; Puente,Vanesa Rocío; Diez,Berenice Andrea; Teijo,María Julieta; Cerbino,Gabriela Nora; Varela,Laura Sabina; Néstor Guolo,Marcelo; Batlle,Alcira María del Carmen.
Las porfirias son enfermedades metabólicas consecuencia de fallas en la biosíntesis del hemo, caracterizadas por un patrón específico de acumulación y excreción de intermediarios, responsables de su patofisiología. En las porfirias agudas el exceso de ácido d-aminolevúlico (ALA) produce una sintomatología neuroabdominal asociada al daño oxidativo por formación de especies reactivas de oxígeno (ROS), originadas por autooxidaxión del ALA. En las cutáneas, la sintomatología es producto de la acumulación de porfirinas, que como el ALA, inducen la formación de ROS. Su desencadenamiento se precipita por factores endógenos (ayuno, estrés, hormonas) y/o exógenos (fármacos), en particular algunos anestésicos. Se presenta una revisión de los estudios bioquímicos y...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Metabolismo del hemo; Porfirias; Porfirinas; Ácido d-aminolevúlico; Anestésicos volátiles; Terapia fotodinámica; Trypanosoma cruzi.
Ano: 2016
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-29572016000400005

Detección de Trypanosoma cruzi en tejido y sangre murina por PCR convencional y en tiempo real
Provedor de dados: 38
Autores: Davies,Carolina; Poma,Ramiro Hugo; Marino Cardozo,Rubén; Mora,María Celia; Ramos,Federico; Rajal,Verónica Beatriz; Basombrío,Miguel Ángel.
El objetivo del presente trabajo fue comparar la detección de ADN de Trypanosoma cruzi mediante PCR en tiempo real (qPCR) y PCR convencional en sangre periférica (n=25) y músculo esquelético (n=20) de ratones tratados con drogas tripanomicidas luego de 6 meses post-tratamiento. En las muestras de sangre se detectaron un total de 7 positivas por qPCR, mientras que por PCR convencional sólo se detectaron 2. En músculo esquelético, 15 muestras fueron positivas por qPCR y 3 por PCR convencional. Los resultados obtenidos demuestran que la fuerza de concordancia es débil entre las técnicas de PCR utilizadas para la detección de ADN de T. cruzi (k=0,37; 49% positivas por qPCR vs. 11% por PCR convencional, p=0,0001). En las muestras de sangre, los valores...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: PCR convencional; PCR en tiempo real; Ratones; Carga parasitaria; Sangre periférica; Músculo esquelético; Trypanosoma cruzi.
Ano: 2014
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-29572014000400004

Diagnóstico de infección por Trypanosoma cruzi en Centros de Atención Primaria de Salta, Argentina
Provedor de dados: 38
Autores: Sánchez Negrette,Olga; Monteros,María Concepción; Davies,Carolina; Zaidenberg,Mario Oscar.
La Enfermedad de Chagas causada por el parásito hemoflagelado Trypanosoma cruzi, constituye un grave problema de Salud Pública. En Argentina, se controla sistemáticamente la sangre a transfundir, la donación de órganos y se ha disminuido notablemente la transmisión vectorial. El objetivo de este proyecto fue implementar el uso del equipo para recolección de sangre capilar y conservación en glicerina (Serokit) en los servicios de enfermería de los Centros de Atención Primaria de la Salud en la ciudad de Salta a fin de conocer la seroprevalencia de infección por Trypanosoma cruzi en pacientes que concurren a los mismos. Para ello se realizó el par serológico HAI y ELISA en las muestras conservadas en Serokit y luego en muestras de sangre tomadas por punción...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Atención primaria de salud; Enfermedad de Chagas; Serología; Niños; Trypanosoma cruzi; Prevención y control.
Ano: 2013
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-29572013000400008

Avaliação da atividade anti-Leishmania e anti-Trypanosoma do extrato etanólico das folhas de Annona squamosa L
Provedor de dados: 40
Autores: Sobreira Dantas Nóbrega de Figuêiredo,Francisco Rodolpho; Gyllyandeson,de Araújo Delmondes; Paulo da Cruz,Luzia; Amaro do Nascimento,Érika; Relison Tintino,Saulo; Santiago Lemos,Izabel Cristina; Bezerra da Cunha,Francisco Assis; Vega Gomez,Maria Celeste; Coronel,Cathia; Martins da Costa,José Galberto; Melo Coutinho,Henrique Douglas; Bezerra Felipe,Cícero Francisco; Alencar de Menezes,Irwin Rose; Kerntopf,Marta Regina.
As doenças parasitárias, também chamadas de &amp;#8220;doenças negligenciadas&amp;#8221;, continuam sendo uma grande dificuldade para o desenvolvimento social e econômico dos países mais pobres. Podemos citar como exemplo dessas doenças, a leishmaniose e a doença de Chagas. A leishmaniose é causada por parasitas do gênero Leishmania e afeta cerca de 12 milhões de pessoas. A doença de Chagas, causada pelo protozoário Trypanosoma cruzi, causa aproximadamente 50.000 mortes por ano. Os fármacos disponíveis para o tratamento dessas doenças são altamente tóxicos, sendo este um dos motivos que leva à busca por drogas eficazes e seguras para seus tratamentos. As folhas da Annona squamosa, espécie da família Annonaceae, já foram descritas na literatura por suas...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Annona squamosa; Annonaceae; Leishmania; Trypanosoma cruzi.
Ano: 2016
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-37432016000300001

In vitro trypanocidal activity of solamargine and extracts from Solanum palinacanthum and Solanum lycocarpum of brazilian cerrado
Provedor de dados: 42
Autores: MOREIRA,RAQUEL R.D.; MARTINS,GILMARCIO Z.; MAGALHÃES,NATHÁLIA O.; ALMEIDA,ADÉLIA E.; PIETRO,ROSEMEIRE C.L.R.; SILVA,FLÁVIA A. J.; CICARELLI,REGINA M.B.
The present investigation was to evaluate the potential trypanocidal activity of crude ethanolic extract of the fruits of Solanum palinacanthum, Solanum lycocarpum and the glycoalcaloid, solamargine. S. palinacanthum and S. lycocarpum fruit powders were submitted to exhaustively extraction with 96% ethanol and solamargine were isolated from the extract of S. palinacanthum. Both extracts and solamargine were analysed for trypanocidal activity by using MTT colorimetric assay. Extracts of S. palinacanthum showed to be more active (IC50 = 175.9 µg.ml–1) than S. lycocarpum (IC50 = 194.7 µg.ml–1). Solamargine presented a strong activity (IC50 = 15.3 µg.ml–1), which can explain the better activity of the both extracts. Benznidazol (IC50 = 9.0 µg.ml–1) is the only...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Solanum palinacanthum; Solanum lycocarpum; Solamargine; Epimastigote; Antitrypanosomal activity; Trypanosoma cruzi.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000300903

Mammalian cell invasion and intracellular trafficking by Trypanosoma cruzi infective forms
Provedor de dados: 42
Autores: Mortara,Renato A.; Andreoli,Walter K.; Taniwaki,Noemi N.; Fernandes,Adriana B.; Silva,Claudio V. da; Fernandes,Maria Cecília D.C.; L'abbate,Carolina; Silva,Solange da.
Trypanosoma cruzi, the etiological agent of Chagas’ disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle and T. cruzi II, linked to the human disease. In the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. Several parasite surface components and some of host cell receptors with which they interact have been identified. Our work focused on how amastigotes, usually found growing in the cytoplasm, can invade mammalian cells with infectivities comparable to that of trypomastigotes. We found differences in cellular responses induced by amastigotes and trypomastigotes regarding...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Cellular invasion; Amastigotes; Trypomastigotes; Parasitophorous vacuole escape; Trafficking; Coxiella burnetii; Phylogenetic lineages.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000100006

Inositol metabolism in Trypanosoma cruzi: potential target for chemotherapy against Chagas' disease
Provedor de dados: 42
Autores: OLIVEIRA,MECIA M.; EINICKER-LAMAS,MARCELO.
Chagas' disease is a debilitating and often fatal disease caused by the protozoan parasite Trypanosoma cruzi. The great majority of surface molecules in trypanosomes are either inositol-containing phospholipids or glycoproteins that are anchored into the plasma membrane by glycosylphosphatidylinositol anchors. The polyalcohol myo-inositol is the precursor for the biosynthesis of these molecules. In this brief review, recent findings on some aspects of the molecular and cellular fate of inositol in T. cruzi life cycle are discussed and identified some points that could be targets for the development of parasite-specific therapeutic agents.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Inositol; Trypanosoma cruzi; Chagas' disease; Chemotherapy.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652000000300015

Balanced cytokine-producing pattern in mice immunized with an avirulent Trypanosoma cruzi
Provedor de dados: 42
Autores: Soares,Milena B. P.; Gonçalves,Renata; Pyrrho,Alexandre S.; Costa,Deise A.; Paiva,Claudia N.; Gattass,Cerli R.
We have previously demonstrated that inoculation of BALB/c mice with trypomastigotes of CL-14, an avirulent Trypanosoma cruzi clone, prevents the development of parasitemia and mortality after challenge with virulent CL strain. In this report, we investigated the cytokine and antibody profiles induced by inoculation with CL-14 clone. Groups of mice were inoculated with trypomastigotes of CL-14 clone and challenged with infective CL strain. Challenged CL-14-inoculated mice had lower levels of IFN-&lt;FONT FACE=Symbol&gt;g&lt;/font&gt; and higher production of IgG1 antibodies as compared to CL strain-infected mice. Previous inoculation with CL-14 clone partially prevented the suppression of IL-2 production caused by CL strain infection. No significant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Protection; Cytokines; Humoral response.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652003000200005

In vitro antiparasitic activity and chemical composition of the essential oil from Protium ovatum leaves (Burceraceae)
Provedor de dados: 42
Autores: ESTEVAM,ELISÂNGELA B.B.; DEUS,ISABELLA P.B. DE; SILVA,VANESSA P. DA; SILVA,ELIZABETH A.J. DA; ALVES,CASSIA C.F.; ALVES,JOSÉ MILTON; CAZAL,CRISTIANE M.; MAGALHÃES,LIZANDRA G.; PAGOTTI,MARIANA C.; ESPERANDIM,VIVIANE R.; SOUZA,ALEX F.; MIRANDA,MAYKER L.D.
ABSTRACT Leishmaniasis and trypanosomiasis are globally widespread parasitic diseases which have been responsible for high mortality rates. Since drugs available for their treatment are highly hepatotoxic, nephrotoxic and cardiotoxic, adherence to therapy has been affected. Thus, the search for new, more effective and safer drugs for the treatment of these diseases is necessary. Natural products have stood out as an alternative to searching for new bioactive molecules with therapeutic potential. In this study, the chemical composition and antiparasitic activity of the essential oil from Protium ovatum leaves against trypomastigote forms of Trypanosoma cruzi and the promastigote forms of Leishmania amazonensis were evaluated. The essential oil was promising...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Leishmania amazonensis; Essential oil; Protium ovatum; Parasitic diseases.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000603005

Susceptible hosts: a resort for parasites right in the eye of the immune response
Provedor de dados: 42
Autores: DOSREIS,GEORGE A.
Trypanosomatid protozoan parasites express an aggressive strategy of parasitism by infecting host macrophages and inducing extensive T-lymphocyte activation. One goal of such strategy is to drive the immune response of genetically susceptible hosts to a state of unresponsiveness regarding parasite killing. Unresponsiveness is achieved through different mechanisms, depending on the parasite species. In this brief review, recent findings on the molecular and cellular bases of the parasites' exploitation of host immune responses are discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Leishmania chagasi; T lymphocytes; CTLA-4; Apoptosis; Transforming growth factor.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652000000100011

The pathogenesis of Chagas' disease: when autoimmune and parasite-specific immune responses meet
Provedor de dados: 42
Autores: SOARES,MILENA B. P.; PONTES-DE-CARVALHO,LAIN; RIBEIRO-DOS-SANTOS,RICARDO.
Chagas' disease is a major health problem in Latin America, where it constitutes one of the leading causes of heart failure. About one fourth of Trypanosoma cruzi-infected individuals develop chronic chagasic cardiomyopathy (CChC), the most severe form of the disease. CChC is histologically characterized by the presence of multifocal inflammatory infiltrates in the heart, composed mainly by mononuclear cells, usually adhered to myocytes and leading to myocytolysis, and frequently by interstitial fibrosis. The pathogenesis of CChC is still unclear, despite intense investigations both in human beings and in animal models of the disease. Although tissue parasitism is rare in the chronic phase of infection, an immune response targeted to persistent parasites...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chagas' disease; Myocarditis; Autoimmunity; Trypanosoma cruzi; Delayed-type hypersensitivity.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000400008

Two special organelles found in Trypanosoma cruzi
Provedor de dados: 42
Autores: SOUZA,WANDERLEY DE; CARREIRO,ISABEL PORTO; MIRANDA,KILDARE; SILVA,NARCISA L. CUNHA E.
We review here two unique organelles from Trypanosoma cruzi. One of them is the acidocalcisome, cytoplasmic vacuoles containing a very high Ca2+ concentration and a Ca2+ - H+ translocating ATPase activity, present in all trypanosomatids. The other organelle is the reservosome, site of accumulation of endocytosed macromolecules, very rich in cysteine proteinase, that is present only in epimastigote forms of trypanosomes belonging to the Schyzotrypanum sub-genus.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acidocalcisome; Reservosome; Trypanosoma cruzi.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652000000300016

Molecular basis of mammalian cell invasion by Trypanosoma cruzi
Provedor de dados: 42
Autores: Yoshida,Nobuko.
Establishment of infection by Trypanosoma cruzi, the agent of Chagas' disease, depends on a series of events involving interactions of diverse parasite molecules with host components. Here we focus on the mechanisms of target cell invasion by metacyclic trypomastigotes (MT) and mammalian tissue culture trypomastigotes (TCT). During MT or TCT internalization, signal transduction pathways are activated both in the parasite and the target cell, leading to Ca2+ mobilization. For cell adhesion, MT engage surface glycoproteins, such as gp82 and gp35/50, which are Ca2+ signal-inducing molecules. In T. cruzi isolates that enter host cells in gp82-mediated manner, parasite protein tyrosine kinase as well as phospholipase C are activated, and Ca2+ is released from I...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Trypomastigotes; Cell invasion; Signal transduction; Ca2+ mobilization.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652006000100010

The pentose phosphate pathway in Trypanosoma cruzi: a potential target for the chemotherapy of Chagas disease
Provedor de dados: 42
Autores: Igoillo-Esteve,Mariana; Maugeri,Dante; Stern,Ana L.; Beluardi,Paula; Cazzulo,Juan J.
Trypanosoma cruzi is highly sensitive to oxidative stress caused by reactive oxygen species. Trypanothione, the parasite's major protection against oxidative stress, is kept reduced by trypanothione reductase, using NADPH; the major source of the reduced coenzyme seems to be the pentose phosphate pathway. Its seven enzymes are present in the four major stages in the parasite's biological cycle; we have cloned and expressed them in Escherichia coli as active proteins. Glucose 6-phosphate dehydrogenase, which controls glucose flux through the pathway by its response to the NADP/NADPH ratio, is encoded by a number of genes per haploid genome, and is induced up to 46-fold by hydrogen peroxide in metacyclic trypomastigotes. The genes encoding...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Chagas disease; Pentose phosphate pathway; Oxidative stress; NADPH generation.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652007000400007

Effect of acetylsalicylic acid on total myenteric neurons in mice experimentally infected with Trypanosoma cruzi
Provedor de dados: 42
Autores: SOUZA,NOEMI D. DE; BELIN,BRUNA S.; MASSOCATTO,CRISTINA L.; ARAÚJO,SILVANA M. DE; SANT’ANA,DÉBORA M.G.; ARAÚJO,EDUARDO J.A.; P. FILHO,PHILENO; NIHEI,OSCAR K.; MOREIRA,NEIDE M.
Abstract: We investigated the effects of acetylsalicylic acid (ASA) on the total myenteric neuronal population in the descending colon in Trypanosoma cruzi-infected mice. Thirty-five male Swiss mice, 60 days old, were divided into a control group (C group), control group treated with ASA (CA group), infected group (I group), and infected group treated with ASA (IA group). A total of 1300 trypomastigotes of the Y strain of T. cruzi were intraperitoneally inoculated in the IA and I groups. The CA and IA groups were treated with ASA intraperitoneally. At 75 days post-infection (dpi), all of the animals were sacrificed. Neurons in the colon were stained with Giemsa, quantified, and measured. No difference in the course of infection was observed between the IA...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acetylsalicylic acid; Colon; Giemsa; Mice; Myenteric neurons; Trypanosoma cruzi.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000300804

Neuronal changes caused by Trypanosoma cruzi: an experimental model
Provedor de dados: 42
Autores: Moreira,Neide M; Sant'ana,Débora M. G; Araújo,Eduardo J. A; Toledo,Max J. O; Gomes,Mônica L; Araújo,Silvana M. de.
Define an experimental model by evaluating quantitative and morphometric changes in myenteric neurons of the colon of mice infected with Trypanosoma cruzi. Twenty-eight Swiss male mice were distributed into groups: control (CG, n=9) and inoculated with 100 (IG100, n=9) and 1000 (IG1000, n=10) blood trypomastigotes, Y strain-T. cruzi II. Parasitemia was evaluated from 3-25 days post inoculation (dpi) with parasites peak of 7.7 × 10(6) and 8.4 × 10(6) trypomastigotes/mL at 8th dpi (p&amp;gt;0.05) in IG100 and IG1000, respectively. Chronic phase of the infection was obtained with two doses of 100mg/Kg/weight and one dose of 250mg/Kg/weight of Benznidazole on 11, 16 and 18 dpi. Three animals from each group were euthanized at 18, 30 and 75 dpi. The colon was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chagas disease; Colon; Enteric nervous system; Giemsa; Trypanosoma cruzi.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000200014

Active transcription and ultrastructural changes during Trypanosoma cruzi metacyclogenesis
Provedor de dados: 42
Autores: Ferreira,Ludmila R.P.; Dossin,Fernando de M.; Ramos,Thiago C.; Freymüller,Edna; Schenkman,Sergio.
The differentiation of proliferating epimastigote forms of Trypanosoma cruzi , the protozoan parasite that causes Chagas’ disease, into the infective and non-proliferating metacyclic forms can be reproduced in the laboratory by incubating the cells in a chemically-defined medium that mimics the urine of the insect vector. Epimastigotes have a spherical nucleus, a flagellum protruding from the middle of the protozoan cell, and a disk-shaped kinetoplast - an organelle that corresponds to the mitochondrial DNA. Metacyclic trypomastigotes have an elongated shape with the flagellum protruding from the posterior portion of the cell and associated with a spherical kinetoplast. Here we describe the morphological events of this transformation and characterize a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Metacyclogenesis; Transcription; RNA polymerase II.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000100011

Chagas disease in prehistory
Provedor de dados: 42
Autores: Ferreira,Luiz F.; Jansen,Ana M.; Araújo,Adauto.
The classical hypothesis proposes that Chagas disease has been originated in the Andean region among prehistoric people when they started domesticating animals, changing to sedentary habits, and adopting agriculture. These changes in their way of life happened nearly 6,000 years ago. However, paleoparasitological data based on molecular tools showed that Trypanosoma cruzi infection and Chagas disease were commonly found both in South and North American prehistoric populations long before that time, suggesting that Chagas disease may be as old as the human presence in the American continent. The study of the origin and dispersion of Trypanosoma cruzi infection among prehistoric human populations may help in the comprehension of the clinical and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ancient DNA; Chagas disease; Mummies; Paleoepideiology; Paleoparasitology; Trypanosoma cruzi.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300022

Correlation between infection rate of triatominies and Chagas Disease in Southwest of Bahia, Brazil: a warning sign?
Provedor de dados: 42
Autores: SILVEIRA,ELIEZER A. DA; RIBEIRO,ISRAEL S.; AMORIM,MIGUEL S.; ROCHA,DALVA V.; COUTINHO,HELDER S.; FREITAS,LEANDRO M. DE; TOMAZI,LAIZE; SILVA,ROBSON A.A. DA.
ABSTRACT Chagas disease, caused by the Trypanosoma cruzi, has a wide distribution in South America, and its main method of control is the elimination of triatomines. It is presented here the geographic distribution and the rate of natural infection by T. cruzi of triatomines collected and evaluated from 2008 to 2013 in southwest of Bahia. Triatomines were captured in the intradomiciliary and peridomiciliary areas of five cities located in the southwest of Bahia state, identified, and analyzed for the presence of trypanosomatids in their feces. During the study period the number of patients suspected for acute Chagas disease was recovered from the Notifiable Diseases Information System (SINAN). 8966 triatomines were captured and identified as belonging to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Infection; Chagas disease; Trypanosoma cruzi; Vector.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000501941

Parameters for evaluation of clinical trial in mice infected with Trypanosoma cruzi
Provedor de dados: 45
Autores: Falkowski,G.J.S.; Sandri,P.F.; Tiyo,R.; Aleixo,D.L.; Araújo,S.M.
The effectiveness of clinical parameters in the evaluation of Trypanosoma cruzi infection was analyzed in male Swiss mice at 8 weeks old Animals were divided into HG (healthy) and IG (1400 trypomastigotes, intraperitoneally, Y strain - Trypanosoma cruzi). Quantitative and qualitative parameters were evaluated in non-consecutive days in the period, from 7th-11th and 15th-18th days of infection. There were significant differences (P&lt;0.05) between both groups in both periods regarding water consumption, abdominal circumference and weight. The second group presented differences in amount of excreta, body temperature, move-up and mortality. There was no difference (P&amp;gt;0.05) between the groups in food consumption, exploration of self-cleaning and skin...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Clinical analysis; Chagas disease; Experimental infection; Mice; Trypanosoma cruzi.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352012000600020

Cysteine proteinases of Trypanosoma cruzi: from digestive enzymes to programmed cell death
Provedor de dados: 47
Autores: Kosec,Gregor; Alvarez,Vanina; Cazzulo,Juan J.
Trypanosoma cruzi, the parasite causing Chagas disease, contains a number of proteolytic enzymes. The recent completion of the genome sequence of the T. cruzi CL Brener clone suggests the presence of 70 cysteine peptidases, 40 serine peptidases (none of them from the chymotrypsin family), about 250 metallopeptidases (most leishmanolysin homologues), 25 threonine peptidases, and only two aspartyl peptidases, none of them from the pepsin family. The cysteine peptidases belong to 7 families of Clan CA, 3 families of Clan CD, and one each of Clans CE and CF. In Clan CA, the C1 family is represented by cruzipains 1 and 2, biochemically well characterized, as well as cathepsin B and two other cathepsins. There are a number of homologues to calpains (family C2),...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Chagas disease; Cysteine proteinases; Apoptosis; Autophagy.
Ano: 2006
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452006000300008

Effects of buthionine sulfoximine nifurtimox and benznidazole upon trypanothione and metallothionein proteins in Trypanosoma cruzi.
Provedor de dados: 48
Autores: MAYA,JUAN DIEGO; RODRÍGUEZ,ANDRÉS; PINO,LAURA; PABÓN,ADRIANA; FERREIRA,JORGE; PAVANI,MARIO; REPETTO,YOLANDA; MORELLO,ANTONIO.
Proteins rich in sulfhydryl groups, such as metallothionein, are present in several strains of the parasite Trypanosoma cruzi, the etiological agent of Chagas' disease. Metallothionein-like protein concentrations ranged from 5.1 to 13.2 pmol/mg protein depending on the parasite strain and growth phase. Nifurtimox and benznidazole, used in the treatment of Chagas' disease, decreased metallothionein activity by approximately 70%. T. cruzi metallothionein was induced by ZnCl2. Metallothionein from T. cruzi was partially purified and its monobromobimane derivative showed a molecular weight of approximately 10,000 Da by SDS-PAGE analysis. The concentration of trypanothione, the major glutathione conjugate in T. cruzi, ranged from 3.8 to 10.8 nmol/mg protein,...
Tipo: Journal article
Palavras-chave: Trypanosoma cruzi; Metallothionein; Glutathione; Trypanothione; Benznidazole; Nifurtimox; Buthionine sulfoximine.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000100007

Studies on parasitemia courses and mortality in mice infected with genetically distant Trypanosoma cruzi clonets
Provedor de dados: 48
Autores: WALLACE,ANNE; ORTÍZ,SILVIA; SÁNCHEZ,GITTITH; VILLAGRA,REBECA; MUGA,MABEL; SOLARI,ALDO.
The biological characterization of bloodstream forms of eleven Trypanosoma cruzi cloned stocks, corresponding to two genetically similar clonets (&lt;A HREF="#19"&gt;19&lt;/A&gt; and &lt;A HREF="#20"&gt;20&lt;/A&gt;) and one distant clonet (39), according to multilocus enzyme electrophoresis analysis, showed dissimilar parasitemia in an experimental isogenic mouse model. While clonet 39 stocks gave low parasitemias, clonets 19 or 20 stocks gave high parasitemias, independently of the inocula (10² and 10(4) bloodstream forms) used. High parasitemia did not always associate with greater mortality. Statistical studies on mortality using a low inocula showed significantly higher mortality with clonet 39 stocks when compared to clonets 19 or 20 stocks. Finally,...
Tipo: Journal article
Palavras-chave: Trypanosoma cruzi; Clonets; Parasitemia; Mortality; Bloodstream forms; Multilocus enzyme electrophoresis.
Ano: 2001
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602001000200011

Sera of Chagasic patients react with antigens from the tomato parasite Phytomonas serpens
Provedor de dados: 48
Autores: Graça-de Souza,Viviane K; Monteiro-Góes,Viviane; Manque,Patrício; Souza,Tatiana A.C.B; Corrêa,Paulo R.C.; Buck,Gregory A; Ávila,Andréa R; Yamauchi,Lucy M; Pinge-Filho,Phileno; Goldenberg,Samuel; Krieger,Marco A; Yamada-Ogatta,Sueli F.
The genus Phytomonas comprises trypanosomatids that can parasitize a broad range of plant species. These fagellates can cause diseases in some plant families with a wide geographic distribution, which can result in great economic losses. We have demonstrated previously that Phytomonas serpens 15T, a tomato trypanosomatid, shares antigens with Trypanosoma cruzi, the agent of human Chagas disease. Herein, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identify proteins of P. serpens 15T that are recognized by sera from patients with Chagas disease. After 2D-electrophoresis of whole-cell lysates, 31 peptides were selected and analyzed by tandem mass spectrometry. Twenty-eight polypeptides were identifed, resulting in 22...
Tipo: Journal article
Palavras-chave: Phytomonas serpens; Trypanosoma cruzi; Antigenic cross-reactivity; Trypanosomatids.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000200011

Cytotoxicity and trypanocidal activity of nifurtimox encapsulated in ethylcyanoacrylate nanoparticles
Provedor de dados: 48
Autores: SÁNCHEZ,GITTITH; CUELLAR,DANIELA; ZULANTAY,INES; GAJARDO,MARTA; GONZÁLEZ-MARTIN,GUILLERMO.
The aim of the present study was to study the trypanocidal activity of nanoparticles loaded with nifurtimox in comparison with the free drug against Trypanosoma cruzi, responsible for Chagas' disease. Ethylcyanoacrylate nanoparticles acted as the delivery system into cells. As the obligate replicative intracellular form is amastigote, in vitro studies were performed on this form of parasite as well as on cell culture derived trypomastigotes. The fluorescence method used here was very useful as it allowed for the simultaneous study of trypanocide activity and cytotoxicity by determining living or dead parasites within living or dead host cells. According to these results, the greatest trypanocide activity on cell culture-derived trypomastigotes was recorded...
Tipo: Journal article
Palavras-chave: Nifurtimox; Nanoparticles; Amastigotes; Trypomastigotes; Trypanosoma cruzi.
Ano: 2002
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000100007

F(ab')2 antibody fragments against Trypanosoma cruzi calreticulin inhibit its interaction with the first component of human complement
Provedor de dados: 48
Autores: AGUILAR,LORENA; RAMÍREZ,GALIA; VALCK,CAROLINA; MOLINA,MARÍA C; ROJAS,ÁLVARO; SCHWAEBLE,WILHELM; FERREIRA,VIVIANA; FERREIRA,ARTURO.
Trypanosoma cruzi calreticulin (TcCRT), described in our laboratory, retains several important functional features from its vertebrate homologues. We have shown that recombinant TcCRT inhibits the human complement system when it binds to the collagenous portion of C1q. The generation of classical pathway convertases and membrane attack complexes is thus strongly inhibited. In most T. cruzi-infected individuals, TcCRT is immunogenic and mediates the generation of specific antibodies. By reverting the C1q / TcCRT interaction, a parasite immune evasion strategy, these antibodies contribute to the host / parasite equilibrium. In an in vitro correlate of this situation, we show that the C1q / TcCRT interaction is inhibited by F(ab')2 polyclonal anti-TcCRT IgG...
Tipo: Journal article
Palavras-chave: Calreticulin; C1q; F(ab')2 antibody fragments; Trypanosoma cruzi.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200008

Chronic Chagas disease: PCR-xenodiagnosis without previous microscopic observation is a useful tool to detect viable Trypanosoma cruzi
Provedor de dados: 48
Autores: Saavedra,Miguel; Zulantay,Inés; Apt,Werner; Martínez,Gabriela; Rojas,Antonio; Rodríguez,Jorge.
We evaluate the elimination of the microscopic stage of conventional xenodiagnosis (XD) to optimize the parasitological diagnosis of Trypanosoma cruzi in chronic Chagas disease. To this purpose we applied under informed consent two XD cages to 150 Chilean chronic chagasic patients. The fecal samples (FS) of the triatomines at 30, 60 and 90 days post feeding were divided into two parts: in one a microscopic search for mobile trypomastigote and/or epimastigote forms was performed. In the other part, DNA extraction-purification for PCR directed to the conserved region of kDNA minicircles of trypanosomes (PCR-XD), without previous microscopic observation was done. An XD was considered positive when at least one mobile T. cruzi parasite in any one of three...
Tipo: Journal article
Palavras-chave: Chronic Chagas disease; PCR; Triatoma infestans; Trypanosoma cruzi; Xenodiagnosis.
Ano: 2013
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602013000300011

Chagas disease: Present status of pathogenic mechanisms and chemotherapy
Provedor de dados: 48
Autores: Maya,Juan Diego; Orellana,Myriam; Ferreira,Jorge; Kemmerling,Ulrike; López-Muñoz,Rodrigo; Morello,Antonio.
There are approximately 7.8 million people in Latin America, including Chile, who suffer from Chagas disease and another 28 million who are at risk of contracting it. Chagas is caused by the flagellate protozoan Trypanosoma cruzi. It is a chronic disease, where 20%-30% of infected individuals develop severe cardiopathy, with heart failure and potentially fatal arrhythmias. Currently, Chagas disease treatment is more effective in the acute phase, but does not always produce complete parasite eradication during indeterminate and chronic phases. At present, only nifurtimox or benznidazole have been proven to be superior to new drugs being tested. Therefore, it is necessary to find alternative approaches to treatment of chronic Chagas. The current treatment...
Tipo: Journal article
Palavras-chave: Chagas disease; Chemotherapy; Nifurtimox; Trypanosoma cruzi; Prostaglandins.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000300009

Early and late molecular and morphologic changes that occur during the in vitro transformation of Trypanosoma cruzi metacyclic trypomastigotes to amastigotes
Provedor de dados: 48
Autores: CONTRERAS,VÍCTOR T; NAVARRO,MARÍA C; DE LIMA,ANA R; DURAN,FRANCY; ARTEAGA,ROSA; FRANCO,YUNAIMY.
The amastigogenesis primary of T. cruzi occurs naturally when metacyclic trypomastigotes transform into amastigotes within the cells of the mammalian host. The in vitro study of the macromolecular changes that occur over several days during the transformation process should provide significant indications of how the parasite adapts to the mammalian host environment. We show here that metacyclic trypomastigotes pre-incubated at 37&amp;deg; C in a protein-rich medium reach a high degree of transformation to amastigotes when re-incubated in the fresh medium. Giemsa-stained smears show that during the pre-incubation phase, the metacyclic trypomastigotes undergo lengthening at the posterior end and a thinning out of the entire body. SDS-PAGE analysis of...
Tipo: Journal article
Palavras-chave: Amastigogenesis; Differentiation; Macromolecular changes; Metacyclic trypomastigotes; Trypanosoma cruzi.
Ano: 2002
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000100008

Divalent cation hinder the solubilization of a tubulin kinase activity from Trypanosoma cruzi epimastigotes
Provedor de dados: 48
Autores: UZCANGA,GRACIELA; GALÁN-CARIDAD,JOSÉ MANUEL; SUAREZ,KAREM NORIS; BUBIS,JOSÉ.
Trypanosoma cruzi epimastigotes were extracted under various conditions in order to examine the role of divalent cations in the solubilization of microtubule proteins. When epimastigotes were homogenized in the presence of 5 mM Mg+2 and 5 mM Ca+2, a protein kinase responsible for phosphorylating tubulin, as well as the tubulin that became phosphorylated, remained tightly associated with the parasite particulate and detergent-resistant fractions. On the contrary, tubulin kinase and its substrate were predominantly released into the parasite cytosolic and detergent-soluble fractions, when epimastigotes were extracted in the presence of 5 mM EDTA and 5 mM EGTA. These evidences demonstrated a divalent cation-dependent solubilization of the enzyme responsible...
Tipo: Journal article
Palavras-chave: Microtubules; Post-translational modification of tubulin; Protein kinase CK2; Protein phosphorylation-dephosphorylation; Signal transduction; Trypanosoma cruzi; Tubulin.
Ano: 2003
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300008

Effect of tripanosomicide benznidazole (Rochagan®) on the biodistribution of sodium pertechnetate (Na99mTcO4) in Wistar rats
Provedor de dados: 52
Autores: Barbosa,Vanessa Santos de Arruda; Holanda,Maria de Carvalho Xavier; Silva,Roseane Pereira da; Oliveira,Daniel Pereira de; Silva Júnior,Maurício Ferreira da; Oliveira,Elias Herculano de; Spyrides,Maria Helena Constantino; Medeiros,Aldo Cunha.
Benznidazole, a drug with specific anti-Trypanosoma cruzi activity, is used in the treatment of Chagas' disease. The radiopharmaceutical sodium pertechnetate (Na99mTcO4) is used to obtain diagnostic images of the stomach, thyroid, parathyroids, salivary glands, brain and in the study of esophageal reflux and blood flow. This study aimed at evaluating in vivo the influence of benznidazole treatment on the sodium pertechnetate biodistribution in Wistar rats. The percentage of radioactivity per gram (%ATI/g) of various organs (brain, heart, esophagus, stomach, small intestine, large intestine, spleen, liver, muscle and blood) was determined. Comparing the treated rats with the controls, we observed that sodium pertechnetate biodistribution did not change when...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antiparasite; Radiopharmaceutical; Technetium-99m; Benznidazole; Biodistribution; Trypanosoma cruzi.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000700028

Trypanosoma cruzi Chagas, 1909: genetic variability of isolates from chronic chagasic patients in the Paraná state, Brazil
Provedor de dados: 52
Autores: Kopp,Rogério Luiz; Miyazaki,Márcia; Thomaz-Soccol,Vanete.
The present work had as objective to verify the genetic diversity among strains of Trypanosoma cruzi isolated in chronic chagasic patients in the Paraná state. Fifty patients with compatible clinical symptoms were selected (cardiopathy, megacolon and/or megaesophagus) and that presented positive serological reaction to T. cruzi. Six strains of the protozoan were isolated in hemoculture and identified by electrophoresis in starch thick gel with aid of 14 isoenzymes (6PGD; G6PD; ME¹; ME²; ICD; PGM; GPI; GOT¹; GOT²; NP¹; NP²; DIA; MPI and FH). The statistical analysis were accomplished by the softwares NTSYs and UPGMA. Eighty-four electromorphs were individualized and four isoenzymes (ICD, GPI, 6PGD, e PGM) showed compatibility for heterozygosis. The phenetic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Multilocus enzyme electrophoresis; Chagas disease; Epidemiology; Phenetic analysis.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000300009

Effect of medicinal plants on the parasitemia of Trypanosoma cruzi and on the biodistribution of sodium pertechnetate (Na99mTcO4)
Provedor de dados: 52
Autores: Silva,Roseane Pereira da; Holanda,Cecília Maria de Carvalho Xavier; Barbosa,Vanessa Santos de Arruda; Oliveira,Daniel Pereira de; Lima,Natália Alves; Câmara,Antônia Cláudia Jácome da; Medeiros,Aldo da Cunha; Constantino,Maria Helena Spyrides.
Artemisia vulgaris (AV) is an antihelmintic and antimalarial drug; Aloe vera(babosa) acts as antidiabetic, laxative and anti-inflammatory;Benznidazole (BZ) is a trypanocidal of Trypanosoma cruzi (TC). Technetium-99m (99mTc) has been used in nuclear medicine to obtain diagnostic images. This study evaluated the plant effects in TC parasitemia and on the biodistribution of 99mTc in mice. Twenty mice were infected by TC. At the peak of parasitemia, 5 mice received babosa; 5 received AV and 5 received BZ. The parasitemia was determined at 0, 2, 4 and 6 h of drugs administration. Five infected mice without drugs, 5 mice without TC and the group treated with AV, received 99mTc. The radioactivity was calculated. Infected mice that received babosa reduced...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aloe vera; Artemisia vulgaris; Technetium-99m; Trypanosoma cruzi; Parasitemia; Biodistribution.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000700034

Conventional serological performance in diagnosis of Chagas' disease in southern Brazil
Provedor de dados: 55
Autores: Araújo,Anelise Bergmann; Berne,Maria Elisabeth Aires.
Results of Chagas' disease diagnosis show disagreement. The aim of this study was to compare commercial tests for Chagas' disease serodiagnosis in southern Brazil. A total of 161 samples were evaluated. Three enzyme-linked immunosorbent assays, one indirect hemagglutination and one indirect immunofluorescence were assessed. Trypomastigote excreted-secreted antigen-blot was a confirmatory method. From 161 samples, 65.84% were positive in all tests, while 34.16% presents mismatch result in at least one of the tests. All techniques tested presented false-positive and/or false-negative results as follows: Enzyme-linked immunosorbent assay 1 had more false-positive results (lower specificity), indirect immunofluorescence had the highest rate of false-negative...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Chagas' disease; Serodiagnosis; Immunoassays.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702013000200010

Definition of a diagnostic routine in individuals with inconclusive serology for chagas disease
Provedor de dados: 55
Autores: Picka,Mariele Cristina Modolo; Meira,Domingos Alves; Carvalho,Thaís Batista de; Peresi,Eliana; Marcondes-Machado,Jussara.
Despite the existence of highly sensitive tests, inconclusive serological results are frequent in chronic chagasic infection. This study aimed to define a diagnostic conduct for 30 individuals with inconclusive serology (G3) for chagasic infection assisted at the Outpatient Unit for Infectious and Parasitic Diseases of the Botucatu School of Medicine. Twenty-one individuals with negative serology (G1) and 33 with positive serology (G2) were also studied. Serological methods ELISA, HAI, IFI and immunoblotting TESA-cruzi were used for G1, G2 and G3, and parasitological methods xenodiagnosis, hemoculture and PCR-LIT were used for G2 and G3 individuals. ELISA, HAI and IFI were performed in 5 different blood samples in G2 and G3. TESA-cruzi was carried out only...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chronic chagasic infection; Trypanosoma cruzi; Inconclusive serology; Immunoblotting.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702007000200012

Differential expression on mitochondrial tryparedoxin peroxidase (mTcTXNPx) in Trypanosoma cruzi after ferrocenyl diamine hydrochlorides treatments
Provedor de dados: 55
Autores: Kohatsu,Andréa A.N.; Silva,Flávia A.J.; Francisco,Acácio I.; Rimoldi,Aline; Silva,Marco T.A.; Vargas,Maria D.; Rosa,João A. da; Cicarelli,Regina M.B.
Abstract Resistance to benznidazole in certain strains of Trypanosoma cruzi may be caused by the increased production of enzymes that act on the oxidative metabolism, such as mitochondrial tryparedoxin peroxidase which catalyses the reduction of peroxides. This work presents cytotoxicity assays performed with ferrocenyl diamine hydrochlorides in six different strains of T. cruzi epimastigote forms (Y, Bolivia, SI1, SI8, QMII, and SIGR3). The last four strains have been recently isolated from triatominae and mammalian host (domestic cat). The expression of mitochondrial tryparedoxin peroxidase was analyzed by the Western blotting technique using polyclonal antibody anti mitochondrial tryparedoxin peroxidase obtained from a rabbit immunized with the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Ferrocenyl diamine hydrochlorides; Mitochondrial tryparedoxin peroxidase (mTcTXNPx); Oxidative stress mechanisms.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702017000200125

Reactivation of Chagas' disease leading to the diagnosis of acquired immunodeficiency syndrome
Provedor de dados: 55
Autores: Santos,Eder de Oliveira; Canela,João dos Reis; Monção,Henry Carlos Gomes; Roque,Mauro José Guedes.
Reactivation of chronic Chagas' disease is a rare condition and occurs only in immunosuppressed patients. We report a case of a patient with a rapid and fatal reactivation of Chagas' disease, manifested by meningoencephalitis, which lead to a diagnosis of acquired immunodeficiency syndrome (AIDS). We believe there is sufficient evidence to include the reactivation of Chagas' disease among the diagnostic criteria of AIDS in Human Immunodeficiency Virus (HIV) infection.
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Chagas' disease; Trypanosoma cruzi; Acquired immunodeficiency syndrome; Human immunodeficiency virus; Meningoencephalitis.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702002000600009

Prevalence of Trypanosoma cruzi/HIV coinfection in southern Brazil
Provedor de dados: 55
Autores: Stauffert,Dulce; Silveira,Mariangela Freitas da; Mesenburg,Marília Arndt; Manta,Adriane Brod; Dutra,Alessandra da Silva; Bicca,Guilherme Lucas de Oliveira; Villela,Marcos Marreiro.
Abstract Chagas disease reactivation has been a defining condition for acquired immune deficiency syndrome in Brazil for individuals coinfected with Trypanosoma cruzi and HIV since 2004. Although the first coinfection case was reported in the 1980s, its prevalence has not been firmly established. In order to know coinfection prevalence, a cross-sectional study of 200 HIV patients was performed between January and July 2013 in the city of Pelotas, in southern Rio Grande do Sul, an endemic area for Chagas disease. Ten subjects were found positive for T. cruzi infection by chemiluminescence microparticle immunoassay and indirect immunofluorescence. The survey showed 5% coinfection prevalence among HIV patients (95% CI: 2.0–8.0), which was 3.8 times as high as...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Chagas disease; Trypanosoma cruzi; AIDS.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702017000200180

Anti-Trypanosoma cruzi antibody detection in blood donors in the Southern Brazil
Provedor de dados: 55
Autores: Araújo,A.B.; Vianna,E.E.S.; Berne,M.E.A.
Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State, Brazil, from 2004 to 2005. Serological study was performed using ELISA Chagatest. Sampling containing values ± 20% cut off were evaluated using ELISA Chagatek, ELISA Alka/Adaltis, IHA Chagatest and IIF Imunocruzi. TESA-Blot was used as a confirmatory procedure in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Blood donors; Serological screening.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702008000600007

Incidence of Trypanosoma cruzi transmission through breastfeeding during acute experimental Chagas disease
Provedor de dados: 55
Autores: Martins,Luciamare Perinetti Alves; Castanho,Roberto Esteves Pires; Nogueira,Adriano Barbosa; Silva,Otavio Turolo da; Gusmão,Alex Silva de.
OBJECTIVE: To verify the incidence of T. cruzi transmission through breastfeeding during acute experimental Chagas' disease. METHODS: Fifteen female Swiss mice were mated and, after pregnancy confirmation, placed in individual cages. A few hours after birth, the females were inoculated with 0.1 mL of blood containing approximately 3 x 10(5) trypomastigote forms of Y strain of T. cruzi and continued breastfeeding for 25 days. RESULTS: In 142 offspring examined no infection through breast-feeding was observed. CONCLUSIONS: The low number of trypomastigote forms ingested by the newborn mice combined with biological and biochemical characteristics of blood trypomastigotes may explain the lack of transmission in this experiment.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Foods for pregnant and breastfeeding mothers; Chagas disease.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702011000200004

Expression of extracellular matrix components and their receptors in the central nervous system during experimental Toxoplasma gondii and Trypanosoma cruzi infection
Provedor de dados: 56
Autores: Silva,A.A.; Roffê,E.; Lannes-Vieira,J.
Alterations in extracellular matrix (ECM) expression in the central nervous system (CNS) usually associated with inflammatory lesions have been described in several pathological situations including neuroblastoma and demyelinating diseases. The participation of fibronectin (FN) and its receptor, the VLA-4 molecule, in the migration of inflammatory cells into the CNS has been proposed. In Trypanosoma cruzi infection encephalitis occurs during the acute phase, whereas in Toxoplasma infection encephalitis is a chronic persisting process. In immunocompromised individuals such as AIDS patients, T. cruzi or T. gondii infection can lead to severe CNS damage. At the moment, there are no data available regarding the molecules involved in the entrance of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Toxoplasma gondii; Trypanosoma cruzi; Central nervous system; Extracellular matrix.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000500013

Cytokine production profile of heart-infiltrating T cells in Chagas' disease cardiomyopathy
Provedor de dados: 56
Autores: Cunha-Neto,E.; Rizzo,L.V.; Albuquerque,F.; Abel,L.; Guilherme,L.; Bocchi,E.; Bacal,F.; Carrara,D.; Ianni,B.; Mady,C.; Kalil,J.
The hallmark of chronic Chagas' disease cardiomyopathy (CCC) is the finding of a T cell-rich inflammatory mononuclear cell infiltrate in the presence of extremely few parasites in the heart lesions. The scarcity of parasites in affected heart tissue casts doubt on the direct participation of Trypanosoma cruzi in CCC heart tissue lesions, and suggests the possible involvement of autoimmunity. The cells in the infiltrate are presumably the ultimate effectors of tissue damage, and there is evidence that such cells recognize cardiac myosin in molecular mimicry with T. cruzi proteins rather than primary reactivity to T. cruzi antigens (Cunha-Neto et al. (1996) Journal of Clinical Investigation, 98: 1709-1712). Recently, we have studied heart-infiltrating T...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Chagas' disease cardiomyopathy; Immunology; Cytokines; Gamma-interferon.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000100018

Molecular mimicry between cardiac myosin and Trypanosoma cruzi antigen B13: identification of a B13-driven human T cell clone that recognizes cardiac myosin
Provedor de dados: 56
Autores: Abel,L.C.J.; Kalil,J.; Cunha-Neto,E.
Previous reports from our group have demonstrated the association of molecular mimicry between cardiac myosin and the immunodominant Trypanosoma cruzi protein B13 with chronic Chagas' disease cardiomyopathy at both the antibody and heart-infiltrating T cell level. At the peripheral blood level, we observed no difference in primary proliferative responses to T. cruzi B13 protein between chronic Chagas' cardiopathy patients, asymptomatic chagasics and normal individuals. In the present study, we investigated whether T cells sensitized by T. cruzi B13 protein respond to cardiac myosin. T cell clones generated from a B13-stimulated T cell line obtained from peripheral blood of a B13-responsive normal donor were tested for proliferation against B13 protein and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Molecular mimicry; Crossreactive T cells; Cardiac myosin; Trypanosoma cruzi; Chagas' disease.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100007

Rapid test for the evaluation of the activity of the prodrug hydroxymethylnitrofurazone in the processing of Trypanosoma cruzi messenger RNAs
Provedor de dados: 56
Autores: Barbosa,C.F.; Okuda,E.S.; Chung,M.C.; Ferreira,E.I.; Cicarelli,R.M.B.
No fully effective treatment has been developed since the discovery of Chagas' disease by Carlos Chagas in 1909. Since drug-resistant Trypanosoma cruzi strains are occurring and the current therapy is effectiveness in the acute phase but with various adverse side effects, more studies are needed to characterize the susceptibility of T. cruzi to new drugs. Many natural and/or synthetic substances showing trypanocidal activity have been used, even though they are not likely to be turned into clinically approved drugs. Originally, drug screening was performed using natural products, with only limited knowledge of the molecular mechanism involved in the development of diseases. Trans-splicing, which is unusual RNA processing reaction and occurs in nematodes...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Trans-splicing; Trypanocidal drugs; Permeable cells; RNA processing; Hydroxymethylnitrofurazone.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000100005

Evasion of immune responses by Trypanosoma cruzi, the etiological agent of Chagas disease
Provedor de dados: 56
Autores: DosReis,G.A.
Infection with the protozoan parasite Trypanosoma cruzi leads to Chagas disease, which affects millions of people in Latin America. Infection with T. cruzi cannot be eliminated by the immune system. A better understanding of immune evasion mechanisms is required in order to develop more effective vaccines. During the acute phase, parasites replicate extensively and release immunomodulatory molecules that delay parasite-specific responses mediated by T cells. This immune evasion allows the parasite to spread in the host. In the chronic phase, parasite evasion relies on its replication strategy of hijacking the TGF-β signaling pathway involved in inflammation and tissue regeneration. In this article, the mechanisms of immune evasion described for T. cruzi...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; T cells; GPI-anchors; TGF-β; Mucin; Apoptosis.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000200001

The use of confocal laser scanning microscopy to analyze the process of parasitic protozoon-host cell interaction
Provedor de dados: 56
Autores: de-Souza,W.; de-Carvalho,T.U.; de-Melo,E.T.; Soares,C.P.; Coimbra,E.S.; Rosestolato,C.T.; Ferreira,S.R.; Vieira,M.
In this communication we review the results obtained with the confocal laser scanning microscope to characterize the interaction of epimastigote and trypomastigote forms of Trypanosoma cruzi and tachyzoites of Toxoplasma gondii with host cells. Early events of the interaction process were studied by the simultaneous localization of sites of protein phosphorylation, revealed by immunocytochemistry, and sites of actin assembly, revealed by the use of labeled phaloidin. The results obtained show that proteins localized in the interaction sites are phosphorylated. The process of formation of the parasitophorous vacuole was monitored by labeling the host cell surface with fluorescent probes for lipids (PKH26), proteins (DTAF) and sialic acid...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Confocal laser scanning microscopy; Host cell-parasite interaction; Trypanosoma cruzi; Toxoplasma gondii.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001100015

How are antibodies involved in the protective mechanism of susceptible mice infected with T. cruzi?
Provedor de dados: 56
Autores: Umekita,L.F.; Mota,I.
Host resistance to Trypanosoma cruzi is dependent on both natural and acquired immune responses. During the acute phase of the infection the presence of IFN-&lt;FONT FACE=Symbol&gt;g&lt;/font&gt;, TNF-&lt;FONT FACE=Symbol&gt;a&lt;/font&gt;, IL-12 and GM-CSF has been closely associated with resistance, whereas TGF-ß and IL-10 have been associated with susceptibility. Several investigators have demonstrated that antibodies are responsible for the survival of susceptible animals in the initial phase of infection and for the maintenance of low levels of parasitemia in the chronic phase. However, how this occurs is not yet understood. Our results and other data in the literature support the hypothesis that the protective role of antibodies in the acute phase of...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Trypanosoma cruzi; Chronic mouse antibodies; Clearance; Cytokines; Acute phase; Susceptible mice.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000300001

Trypanosoma cruzi: amastigote polymorphism defined by monoclonal antibodies
Provedor de dados: 56
Autores: Verbisck,N.V.; Da-Silva,S.; Mortara,R.A.
We have raised monoclonal antibodies (mAbs) directed towards amastigote forms of Trypanosoma cruzi, and shown that mAbs 1D9 and 4B9 are carbohydrate while mAb 4B5 activity is resistant to periodate oxidation of the antigen. Here we used an ELISA to quantitate and compare the expression of surface epitopes on fixed parasites among different parasite isolates. The expression of markers varied among T. cruzi amastigotes isolated from infected cells or after extracellular differentiation of trypomastigotes. Moreover, we also observed an extensive polymorphic expression of these epitopes among amastigotes derived from different strains and clones. For instance, mAb 2C2 strongly and evenly reacted with 9 strains and clones (G, Y, CL, Tulahuen, MD, and F, and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Amastigote; Monoclonal antibodies; Surface antigen; Polymorphism.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001200011

Signal transduction induced in Trypanosoma cruzi metacyclic trypomastigotes during the invasion of mammalian cells
Provedor de dados: 56
Autores: Yoshida,N.; Favoreto Jr.,S.; Ferreira,A.T.; Manque,P.M.
Penetration of Trypanosoma cruzi into mammalian cells depends on the activation of the parasite's protein tyrosine kinase and on the increase in cytosolic Ca2+ concentration. We used metacyclic trypomastigotes, the T. cruzi developmental forms that initiate infection in mammalian hosts, to investigate the association of these two events and to identify the various components of the parasite signal transduction pathway involved in host cell invasion. We have found that i) both the protein tyrosine kinase activation, as measured by phosphorylation of a 175-kDa protein (p175), and Ca2+ mobilization were induced in the metacyclic forms by the HeLa cell extract but not by the extract of T. cruzi-resistant K562 cells; ii) treatment of parasites with the tyrosine...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Signal transduction; Metacyclic trypomastigotes; Protein kinase; Calcium response; Cell invasion.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000300003

The non-palindromic adaptor-PCR method for the identification of the T-cell receptor genes of an interferon-gamma-secreting T-cell hybridomaspecific for trans-sialidase, an immunodominant Trypanosoma cruzi antigen
Provedor de dados: 56
Autores: Hiyane,M.I.; Boscardin,S.B.; Rodrigues,M.M.
Cloning of the T-cell receptor genes is a critical step when generating T-cell receptor transgenic mice. Because T-cell receptor molecules are clonotypical, isolation of their genes requires reverse transcriptase-assisted PCR using primers specific for each different Valpha or Vß genes or by the screening of cDNA libraries generated from RNA obtained from each individual T-cell clone. Although feasible, these approaches are laborious and costly. The aim of the present study was to test the application of the non-palindromic adaptor-PCR method as an alternative to isolate the genes encoding the T-cell receptor of an antigen-specific T-cell hybridoma. For this purpose, we established hybridomas specific for trans-sialidase, an immunodominant Trypanosoma...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: NPA-PCR method; T-cell receptor; Trypanosoma cruzi; Trans-sialidase.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300005

Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi
Provedor de dados: 56
Autores: Melo,E.J.T.; Beiral,H.J.
Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase) on the multiplication of L. amazonensis, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM) for 48 h. Hydroxyurea arrested intracellular multiplication of all infective forms of the parasites tested. In treated cultures, the percent of infected host cells decreased (50-97%) and most intracellular parasites were eliminated. Ultrastructural observations showed no morphologic change in host cells while intracellular parasites presented drastic...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Toxoplasma gondii; Trypanosoma cruzi; Leishmania amazonensis; Hydroxyurea.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000100009

Immunocytochemical and biochemical detection of alpha-L-fucosidase in Trypanosoma cruzi
Provedor de dados: 56
Autores: Miletti,L.C.; Almeida-de-Faria,M.; Colli,W.; Alves,M.J.M.
The aim of the present study was to demonstrate the presence of alpha-L-fucosidase in Trypanosoma cruzi. Immunocytochemical and biochemical techniques were used to localize and characterize a membrane-associated, neutral-pH-optimum, alpha-L-fucosidase from the parasite. Light and electron microscopy localized the alpha-L-fucosidase specifically on the surface of the parasite and on membranes in the posterior region of the epimastigote stage. Although much less intense, labeling was also detected on the surface of trypomastigotes. At least 50% of the alpha-L-fucosidase activity was associated with epimastigote membrane solubilized with 1 M NaCl or 1% Triton X-100, suggesting that alpha-L-fucosidase is peripherally associated with membranes. The enzyme from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Trypanosomatids; Fucosidase; Fucose; Glycoproteins; Glycolipids.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000500006

Immunodominance: a new hypothesis to explain parasite escape and host/parasite equilibrium leading to the chronic phase of Chagas' disease?
Provedor de dados: 56
Autores: Rodrigues,M.M.; Alencar,B.C.G. de; Claser,C.; Tzelepis,F.
Intense immune responses are observed during human or experimental infection with the digenetic protozoan parasite Trypanosoma cruzi. The reasons why such immune responses are unable to completely eliminate the parasites are unknown. The survival of the parasite leads to a parasite-host equilibrium found during the chronic phase of chagasic infection in most individuals. Parasite persistence is recognized as the most likely cause of the chagasic chronic pathologies. Therefore, a key question in Chagas' disease is to understand how this equilibrium is established and maintained for a long period. Understanding the basis for this equilibrium may lead to new approaches to interventions that could help millions of individuals at risk for infection or who are...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Chagas' disease; Trypanosoma cruzi; Immunodominance; Major histocompatibility complex.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000300001

Protein 3-nitrotyrosine formation during Trypanosoma cruzi infection in mice
Provedor de dados: 56
Autores: Naviliat,M.; Gualco,G.; Cayota,A.; Radi,R.
Nitric oxide (·NO) is a diffusible messenger implicated in Trypanosoma cruzi resistance. Excess production of ·NO and oxidants leads to the generation of nitrogen dioxide (·NO2), a strong nitrating agent. Tyrosine nitration is a post-translational modification resulting from the addition of a nitro (-NO2) group to the ortho-position of tyrosine residues. Detection of protein 3-nitrotyrosine is regarded as a marker of nitro-oxidative stress and is observed in inflammatory processes. The formation and role of nitrating species in the control and myocardiopathy of T. cruzi infection remain to be studied. We investigated the levels of ·NO and protein 3-nitrotyrosine in the plasma of C3H and BALB/c mice and pharmacologically modulated their production during...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Peroxynitrite; Nitric oxide; Nitrotyrosine; Free radicals; Trypanosoma cruzi; Chagas' disease.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005001200011

Trypanosoma cruzi infection induces up-regulation of cardiac muscarinic acetylcholine receptors in vivo and in vitro
Provedor de dados: 56
Autores: Peraza-Cruces,K.; Gutiérrez-Guédez,L.; Castañeda Perozo,D.; Lankford,C.R.; Rodríguez-Bonfante,C.; Bonfante-Cabarcas,R.
The pathogenesis of chagasic cardiomyopathy is not completely understood, but it has been correlated with parasympathetic denervation (neurogenic theory) and inflammatory activity (immunogenic theory) that could affect heart muscarinic acetylcholine receptor (mAChR) expression. In order to further understand whether neurogenic and/or immunogenic alterations are related to changes in mAChR expression, we studied two models of Trypanosoma cruzi infection: 1) in 3-week-old male Sprague Dawley rats chronically infected with T. cruzi and 2) isolated primary cardiomyocytes co-cultured with T. cruzi and peripheral blood mononuclear cells (PBMC). Using [³H]-quinuclidinylbenzilate ([³H]-QNB) binding assays, we evaluated mAChR expression in homogenates from selected...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chagas disease; Muscarinic acetylcholine receptor; Super-sensitivity; Trypanosoma cruzi; Immunogenic theory; Neurogenic theory.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000900009

Endothelin-1 receptors play a minor role in the protection against acute Trypanosoma cruzi infection in mice
Provedor de dados: 56
Autores: Roffê,E.; Souza,A.L.S.; Machado,P.P.; Barcelos,L.S.; Romanha,A.J.; Mariano,F.S.; Silva,J.S.; Machado,C.R.; Tanowitz,H.B.; Teixeira,M.M.
Chagas' disease, caused by the protozoan Trypanosoma cruzi, is a major cause of cardiovascular disability in countries where it is endemic. Damage to the heart microvasculature has been proposed to be an important factor in the pathogenesis of heart dysfunction. Endothelin-1 (ET-1) is a potent vasoconstrictor and exerts its effects via specific ET A and ET B receptors. A few studies have suggested a role for ET-1 and its receptors in the pathogenesis of Chagas' disease. We investigated the effects of treatment with bosentan, an ET A/ET B receptor antagonist, on the course of T. cruzi infection (Y strain) in C57Bl/6 mice. Treatment with bosentan (100 mg kg-1 day-1) was given per os starting day 0 after infection until sacrifice. Bosentan significantly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Endothelin; Myocarditis; Chemokines.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000300015

Modulation of B lymphocyte function by an aqueous fraction of the ethanol extract of Cissampelos sympodialis Eichl (Menispermaceae)
Provedor de dados: 56
Autores: Alexandre-Moreira,M.S.; Piuvezam,M.R.; Pecanha,L.M.T.
Cissampelos sympodialis Eichl species are used in folk medicine for the treatment of asthma, arthritis and rheumatism. In the present study, we investigated the immunomodulatory effect of an aqueous fraction of a 70% (v/v) ethanol extract of C. sympodialis leaves on B lymphocyte function. The hydroalcoholic extract inhibited the in vitro proliferative response of resting B cells induced by LPS (IC50 = 17.2 µg/ml), anti-delta-dextran (IC50 = 13.9 µg/ml) and anti-IgM (IC50 = 24.3 µg/ml) but did not affect the anti-MHC class II antibody-stimulated proliferative response of B cell blasts obtained by stimulation with IL-4 and anti-IgM. Incubation with the hydroalcoholic extract used at 50 µg/ml induced a 700% increase in intracellular cAMP levels. IgM secretion...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: B lymphocytes; Cissampelos sympodialis; Natural products; Trypanosoma cruzi; Immunoglobulin.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001100010

Cissampelos sympodialis Eichl (Menispermaceae) leaf extract induces interleukin-10-dependent inhibition of Trypanosoma cruzi killing by macrophages
Provedor de dados: 56
Autores: Alexandre-Moreira,M.S.; Freire-de-Lima,C.G.; Trindade,M.N.; Castro-Faria-Neto,H.C.; Piuvezam,M.R.; Peçanha,L.M.T.
The aqueous fraction of the ethanolic extract (AFL) of Cissampelos sympodialis Eichl (Menispermaceae), popularly known as milona, has been shown to have both immunosuppressive and anti-inflammatory effects. In the present study we investigated the modulation of macrophage antimicrobicidal activity by in vitro treatment with the extract from C. sympodialis. Normal and thioglycolate-elicited mouse peritoneal macrophages were infected in vitro with the protozoan Trypanosoma cruzi DM28c clone. We observed that the AFL (used at doses ranging from 13 to 100 µg/ml) increased T. cruzi growth and induced a 75% reduction in nitric oxide production. This inhibition could be mediated by the stimulation of macrophage interleukin-10 (IL-10) secretion since the in vitro...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cissampelos sympodialis; Macrophage; Trypanosoma cruzi; Nitric oxide; Interleukin-10.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000200006

Trypanosoma cruzi infection: a continuous invader-host cell cross talk with participation of extracellular matrix and adhesion and chemoattractant molecules
Provedor de dados: 56
Autores: Marino,A.P.M.P.; Silva,A.A.; Pinho,R.T.; Lannes-Vieira,J.
Several lines of evidence have shown that Trypanosoma cruzi interacts with host extracellular matrix (ECM) components producing breakdown products that play an important role in parasite mobilization and infectivity. Parasite-released antigens also modulate ECM expression that could participate in cell-cell and/or cell-parasite interactions. Increased expression of ECM components has been described in the cardiac tissue of chronic chagasic patients and diverse target tissues including heart, thymus, central nervous system and skeletal muscle of experimentally T. cruzi-infected mice. ECM components may adsorb parasite antigens and cytokines that could contribute to the establishment and perpetuation of inflammation. Furthermore, T. cruzi-infected mammalian...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Extracellular matrix; Cell adhesion; Cell migration; Adhesion molecules; Chemokines.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000800020

Presence of autoantibodies against HeLa small nuclear ribonucleoproteins in chagasic and non-chagasic cardiac patients
Provedor de dados: 56
Autores: Bosetto,M.C.; Peixoto,M.S.; Castro,L.I.R. de; Cicarelli,R.M.B.
We detected anti-human small nuclear ribonucleoprotein (snRNP) autoantibodies in chagasic patients by different immunological methods using HeLa snRNPs. ELISA with Trypanosoma cruzi total lysate antigen or HeLa human U small nuclear ribonucleoproteins (UsnRNPs) followed by incubation with sera from chronic chagasic and non-chagasic cardiac patients was used to screen and compare serum reactivity. Western blot analysis using a T. cruzi total cell extract was also performed in order to select some sera for Western blot and immunoprecipitation assays with HeLa nuclear extract. ELISA showed that 73 and 95% of chronic chagasic sera reacted with HeLa UsnRNPs and T. cruzi antigens, respectively. The Western blot assay demonstrated that non-chagasic cardiac sera...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chagas' disease; Autoantibodies; Small nuclear ribonucleoprotein; Trypanosoma cruzi; HeLa cells; Cross-reactivity.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000100006

Induction of cell-mediated immunity during early stages of infection with intracellular protozoa
Provedor de dados: 56
Autores: Gazzinelli,R.T.; Talvani,A.; Camargo,M.M.; Santiago,H.C.; Oliveira,M.A.P.; Vieira,L.Q.; Martins,G.A.; Aliberti,J.C.S.; Silva,J.S.
Toxoplasma gondii and Trypanosoma cruzi are intracellular parasites which, as part of their life cycle, induce a potent cell-mediated immunity (CMI) maintained by Th1 lymphocytes and IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt;. In both cases, induction of a strong CMI is thought to protect the host against rapid parasite multiplication and consequent pathology and lethality during the acute phase of infection. However, the parasitic infection is not eliminated by the immune system and the vertebrate host serves as a parasite reservoir. In contrast, Leishmania sp, which is a slow growing parasite, appears to evade induction of CMI during early stages of infection as a strategy for surviving in a hostile environment (i.e., inside the macrophages which are...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leishmania; Toxoplasma gondii; Trypanosoma cruzi; Macrophages; Cytokines; Nitric oxide.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000100012

Trypanosoma cruzi infection and/or administration of the nonsteroidal anti-inflammatory nimesulide increase the number of colonic crypts overexpressing metallothioneins in rat colon carcinogenesis
Provedor de dados: 56
Autores: Escalante,R.D.; de Oliveira,Ê.C.; Cunha,F.Q.; Vespúcio,M.V.O.; Ribeiro-Silva,A.; Aprilli,F.; Garcia,S.B.
Trypanosoma cruzi infection and nonsteroidal anti-inflammatory drugs inhibit colorectal carcinogenesis by mechanisms not completely known and metallothionein proteins (MTs) may be involved in this process. Sixty-six male Wistar rats weighing 90 to 120 g were randomly divided into seven groups (GI to GVII). GI, GII and GIII animals were subcutaneously infected with 200,000 trypomastigote forms of the Y strain of T. cruzi. After 8 weeks, GI, GII, GIV, and GVI were injected with one weekly subcutaneous dose of 12 mg/kg dimethylhydrazine for 4 weeks. In sequence, GI, GIV and GV were treated with nimesulide (10 mg/kg per dose, five times per week for 8 weeks). Groups I, III, IV, and VI had 12 animals, and each of the other groups had 6 animals. All the animals...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Nimesulide; Dimethylhydrazine; Metallothioneins; Colon carcinogenesis.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700007

Cytokines in innate and acquired immunity to Trypanosoma cruzi infection
Provedor de dados: 56
Autores: Abrahamsohn,I.A.
Resistance to Trypanosoma cruzi infections is critically dependent on cytokine-mediated activation of cell-mediated immune effector mechanisms. This review focuses on the role of IL-10, TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt;, IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; and IL-12 in controlling T. cruzi replication by the innate and specific immune systems of the vertebrate host. A study performed on mice with disrupted recombinase-activating genes (RAG/KO), which lack T and B lymphocytes, revealed the importance of IL-12, IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; and TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt; in the resistance against T. cruzi mediated by the innate immune system. In addition, data from experiments using IL-10 KO, RAG/KO and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Interferon-gamma; Interleukin-12; TNF-alpha; Interleukin-10; Innate immunity; Knock-out mice.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000100015

RNA and DNA aptamers as potential tools to prevent cell adhesion in disease
Provedor de dados: 56
Autores: Ulrich,H.; Alves,M.J.M.; Colli,W.
Recent research has shown that receptor-ligand interactions between surfaces of communicating cells are necessary prerequisites for cell proliferation, cell differentiation and immune defense. Cell-adhesion events have also been proposed for pathological conditions such as cancer growth, metastasis, and host-cell invasion by parasites such as Trypanosoma cruzi. RNA and DNA aptamers (aptus = Latin, fit) that have been selected from combinatorial nucleic acid libraries are capable of binding to cell-adhesion receptors leading to a halt in cellular processes induced by outside signals as a consequence of blockage of receptor-ligand interactions. We outline here a novel approach using RNA aptamers that bind to T. cruzi receptors and interrupt host-cell...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: SELEX; Aptamers; Cell adhesion; Cell invasion; Trypanosoma cruzi.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000300002

Renovascular hypertension increases serum TNF and CX3CL1 in experimental Trypanosoma cruzi infection
Provedor de dados: 56
Autores: Silva,M.C.; Azevedo,M.A.; Figueiredo,V.P.; Moura Junior,M.R.; Coelho Junior,D.; Martinelli,P.M.; Machado,R.P.; Alzamora,A.C.; Talvani,A.
Trypanosoma cruzi triggers a progressive inflammatory response affecting cardiovascular functions in humans and experimental models. Angiotensin II, a key effector of the renin-angiotensin system, plays roles in mediating hypertension, heart failure, and inflammatory responses. T. cruzi and AngII can induce inflammatory responses by releasing inflammatory mediators. The aim of this study was to evaluate systemic AngII, tumor necrosis factor (TNF), and CX3CL1 mediators in a two-kidney one-clip (2K1C) renovascular hypertension model using Wistar rats infected with T. cruzi. Our data showed an increase in serum AngII in uninfected and T. cruzi-infected rats 1 week after 2K1C surgery compared to non-2K1C (Sham) animals. The baseline systolic blood pressure was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Hypertension; Tumor necrosis factor; CX3CL1; Cardiac inflammation.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2018000500614

Clearance-inducing antibodies are responsible for protection against the acute phase of Trypanosoma cruzi infection in mice
Provedor de dados: 56
Autores: Umekita,L.F.; Ramos,D.P.; Mota,I.
A study was conducted on mice infected with strains Y and CL of Trypanosoma cruzi. The ability of anti-Y and anti-CL sera to induce complement-mediated lysis, immune clearance and protection against the acute phase of the infection was studied using homologous anti-Y or anti-CL serum tested with the Y or CL strain, or heterologous anti-Y serum tested with the CL strain or anti-CL serum tested with the Y strain. Complement-mediated lysis was induced by both homologous and heterologous antisera but protection was afforded only by homologous antisera. Immune clearance was induced by homologous but not by heterologous antisera. Antisera with high clearance ability were able to confer protection whereas antisera with high lytic ability were not. These results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trypanosoma cruzi; Clearance; Complement-mediated lysis; Protection.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001000009

Biological activity of the essential oils from Cinnamodendron dinisii and Siparuna guianensis
Provedor de dados: 58
Autores: Andrade,Milene Aparecida; Cardoso,Maria das Graças; Gomes,Marcos de Souza; Azeredo,Camila Maria Oliveira de; Batista,Luís Roberto; Soares,Maurilio José; Rodrigues,Leonardo Milani Avelar; Figueiredo,Ana Cristina S.
This study had analyzed the antibacterial, antifungal and trypanocidal activity of the essential oils from Cinnamodendron dinisii Schwacke (Canellaceae) and Siparuna guianensis Aublet (Siparunaceae). The essential oils were obtained from fresh leaves by hydrodistillation, using a modified Clevenger apparatus. Chemical analysis by gas-liquid chromatography coupled to mass spectrometry (GC-MS) showed that these essential oils are rich in monoterpene and sesquiterpene hydrocarbons. Activity against the pathogenic bacteria Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella choleraesuis and Staphylococcus aureus was evaluated with the agar cavity diffusion method, while activity on the filamentous fungi Aspergillus flavus, Aspergillus...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Volatile oils; Fungi; Bacteria; Trypanosoma cruzi.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000100189

Leishmanicidal, trypanocidal, and cytotoxic activities of endophytic fungi associated with bioactive plants in Brazil
Provedor de dados: 58
Autores: Rosa,Luiz H.; Gonçalves,Vívian N.; Caligiorne,Rachel B.; Alves,Tânia M. A.; Rabello,Ana; Sales,Policarbo A.; Romanha,Alvaro J.; Sobral,Marcos E. G.; Rosa,Carlos A.; Zani,Carlos L.
One hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive Brazilian plant species Ageratum myriadenia, Palicourea tetraphylla, Piptadenia adiantoides, and Trixis vauthieri. All fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. The crude extracts were tested in bioassay panels using Leishmania amazonensis, Trypanosoma cruzi, the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and three human cancer cell lines. Thirty-three extracts (27.2%) exhibited at least one biological activity. Seventeen extracts (14%) were cytotoxic against one or more human cancer cell line with the IC50 values ranged of &gt;0.2 to 25 µg/mL. Twenty-four extracts (19.8%)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Endophytic fungi; Human tumoral cell; Leishmania; Secondary metabolites; Trypanosoma cruzi.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000200024

Miocardite chagásica em caninos no Estado do Rio Grande do Sul
Provedor de dados: 65
Autores: Pavarini,Saulo Petinatti; Oliveira,Eduardo Conceição de; Bandarra,Paulo Mota; Leal,Juliano Souza; Umezawa,Eufrosina Setsu; Rozza,Daniela Bernadete; Driemeier,David.
Neste trabalho, são relatados dois casos de morte súbita por doença de Chagas aguda em caninos da zona rural de Porto Alegre, Rio Grande do Sul, Brasil. Os cães, um macho Pit Bull com nove meses (canino 1) e uma fêmea Labrador Retriever com dois anos (canino 2), morreram em janeiro de 2005 e maio de 2008, respectivamente. As necropsias revelaram aumento cardíaco em ambos os casos. O coração do canino 2 apresentou formato globoso com múltiplas áreas pálidas na musculatura cardíaca, mais evidentes no ventrículo direito e câmaras cardíacas dilatadas, principalmente as da direita. Ao exame histológico, ambos os casos apresentaram alterações semelhantes caracterizadas por infiltrado inflamatório difuso não-purulento acentuado, predominantemente linfocitário...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Miocardite; Cães; Trypanosoma cruzi.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782009000400044

Aspectos clínico-laboratoriais da infecção natural por Trypanosoma cruzi em cães de Mato Grosso do Sul
Provedor de dados: 65
Autores: Souza,Alda Izabel de; Paulino-Junior,Daniel; Sousa,Marlos Gonçalves; Camacho,Aparecido Antonio.
A doença de Chagas causada pelo T. cruzi é transmitida, principalmente, por insetos vetores e está distribuída na Argentina, no Chile, na Venezuela e no Brasil. O cão, além de ser um importante reservatório, também é vítima da doença e a única espécie capaz de desenvolver manifestações clínicas iguais a do homem. O presente trabalho teve como objetivo descrever as alterações clínicas encontradas em quatro cães infectados naturalmente pelo T. cruzi e alertar para a possibilidade de que a ocorrência dessa enfermidade em cães de Mato Grosso do Sul possa estar sendo subestimada. Os animais foram selecionados a partir de exames sorológicos de reação de imunofluorescência indireta (RIFI), ensaio imunossorvente ligado à enzima (ELISA) e immunoblotting com...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Doença de Chagas; Trypanosoma cruzi; Cão; Aspectos clínicos.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782008000500024