37 research outputs found
Vaccination with Recombinant Microneme Proteins Confers Protection against Experimental Toxoplasmosis in Mice
Toxoplasmosis, a zoonotic disease caused by Toxoplasma gondii, is an important public health problem and veterinary concern. Although there is no vaccine for human toxoplasmosis, many attempts have been made to develop one. Promising vaccine candidates utilize proteins, or their genes, from microneme organelle of T. gondii that are involved in the initial stages of host cell invasion by the parasite. In the present study, we used different recombinant microneme proteins (TgMIC1, TgMIC4, or TgMIC6) or combinations of these proteins (TgMIC1-4 and TgMIC1-4-6) to evaluate the immune response and protection against experimental toxoplasmosis in C57BL/6 mice. Vaccination with recombinant TgMIC1, TgMIC4, or TgMIC6 alone conferred partial protection, as demonstrated by reduced brain cyst burden and mortality rates after challenge. Immunization with TgMIC1-4 or TgMIC1-4-6 vaccines provided the most effective protection, since 70% and 80% of mice, respectively, survived to the acute phase of infection. In addition, these vaccinated mice, in comparison to non-vaccinated ones, showed reduced parasite burden by 59% and 68%, respectively. The protective effect was related to the cellular and humoral immune responses induced by vaccination and included the release of Th1 cytokines IFN-γ and IL-12, antigen-stimulated spleen cell proliferation, and production of antigen-specific serum antibodies. Our results demonstrate that microneme proteins are potential vaccines against T. gondii, since their inoculation prevents or decreases the deleterious effects of the infection
Terrestrial behavior in titi monkeys (Callicebus, Cheracebus, and Plecturocebus) : potential correlates, patterns, and differences between genera
For arboreal primates, ground use may increase dispersal opportunities, tolerance to habitat change, access to ground-based resources, and resilience to human disturbances, and so has conservation implications. We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality. We examined whether the frequency of terrestrial activity correlated with study duration (a proxy for sampling effort), rainfall level (a proxy for food availability seasonality), and forest height (a proxy for vertical niche dimension). Terrestrial activity was recorded frequently for Callicebus and Plecturocebus spp., but rarely for Cheracebus spp. Terrestrial resting, anti-predator behavior, geophagy, and playing frequencies in Callicebus and Plecturocebus spp., but feeding and moving differed. Callicebus spp. often ate or searched for new leaves terrestrially. Plecturocebus spp. descended primarily to ingest terrestrial invertebrates and soil. Study duration correlated positively and rainfall level negatively with terrestrial activity. Though differences in sampling effort and methods limited comparisons and interpretation, overall, titi monkeys commonly engaged in a variety of terrestrial activities. Terrestrial behavior in Callicebus and Plecturocebus capacities may bolster resistance to habitat fragmentation. However, it is uncertain if the low frequency of terrestriality recorded for Cheracebus spp. is a genus-specific trait associated with a more basal phylogenetic position, or because studies of this genus occurred in pristine habitats. Observations of terrestrial behavior increased with increasing sampling effort and decreasing food availability. Overall, we found a high frequency of terrestrial behavior in titi monkeys, unlike that observed in other pitheciids
Taking the pulse of Earth's tropical forests using networks of highly distributed plots
Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of funding agencies. Here we show how a global community is responding to the challenges of tropical ecosystem research with diverse teams measuring forests tree-by-tree in thousands of long-term plots. We review the major scientific discoveries of this work and show how this process is changing tropical forest science. Our core approach involves linking long-term grassroots initiatives with standardized protocols and data management to generate robust scaled-up results. By connecting tropical researchers and elevating their status, our Social Research Network model recognises the key role of the data originator in scientific discovery. Conceived in 1999 with RAINFOR (South America), our permanent plot networks have been adapted to Africa (AfriTRON) and Southeast Asia (T-FORCES) and widely emulated worldwide. Now these multiple initiatives are integrated via ForestPlots.net cyber-infrastructure, linking colleagues from 54 countries across 24 plot networks. Collectively these are transforming understanding of tropical forests and their biospheric role. Together we have discovered how, where and why forest carbon and biodiversity are responding to climate change, and how they feedback on it. This long-term pan-tropical collaboration has revealed a large long-term carbon sink and its trends, as well as making clear which drivers are most important, which forest processes are affected, where they are changing, what the lags are, and the likely future responses of tropical forests as the climate continues to change. By leveraging a remarkably old technology, plot networks are sparking a very modern revolution in tropical forest science. In the future, humanity can benefit greatly by nurturing the grassroots communities now collectively capable of generating unique, long-term understanding of Earth's most precious forests.Additional co-authors: Susan Laurance, William Laurance, Francoise Yoko Ishida, Andrew Marshall, Catherine Waite, Hannsjoerg Woell, Jean-Francois Bastin, Marijn Bauters, Hans Beeckman, Pfascal Boeckx, Jan Bogaert, Charles De Canniere, Thales de Haulleville, Jean-Louis Doucet, Olivier Hardy, Wannes Hubau, Elizabeth Kearsley, Hans Verbeeck, Jason Vleminckx, Steven W. Brewer, Alfredo Alarcón, Alejandro Araujo-Murakami, Eric Arets, Luzmila Arroyo, Ezequiel Chavez, Todd Fredericksen, René Guillén Villaroel, Gloria Gutierrez Sibauty, Timothy Killeen, Juan Carlos Licona, John Lleigue, Casimiro Mendoza, Samaria Murakami, Alexander Parada Gutierrez, Guido Pardo, Marielos Peña-Claros, Lourens Poorter, Marisol Toledo, Jeanneth Villalobos Cayo, Laura Jessica Viscarra, Vincent Vos, Jorge Ahumada, Everton Almeida, Jarcilene Almeida, Edmar Almeida de Oliveira, Wesley Alves da Cruz, Atila Alves de Oliveira, Fabrício Alvim Carvalho, Flávio Amorim Obermuller, Ana Andrade, Fernanda Antunes Carvalho, Simone Aparecida Vieira, Ana Carla Aquino, Luiz Aragão, Ana Claudia Araújo, Marco Antonio Assis, Jose Ataliba Mantelli Aboin Gomes, Fabrício Baccaro, Plínio Barbosa de Camargo, Paulo Barni, Jorcely Barroso, Luis Carlos Bernacci, Kauane Bordin, Marcelo Brilhante de Medeiros, Igor Broggio, José Luís Camargo, Domingos Cardoso, Maria Antonia Carniello, Andre Luis Casarin Rochelle, Carolina Castilho, Antonio Alberto Jorge Farias Castro, Wendeson Castro, Sabina Cerruto Ribeiro, Flávia Costa, Rodrigo Costa de Oliveira, Italo Coutinho, John Cunha, Lola da Costa, Lucia da Costa Ferreira, Richarlly da Costa Silva, Marta da Graça Zacarias Simbine, Vitor de Andrade Kamimura, Haroldo Cavalcante de Lima, Lia de Oliveira Melo, Luciano de Queiroz, José Romualdo de Sousa Lima, Mário do Espírito Santo, Tomas Domingues, Nayane Cristina dos Santos Prestes, Steffan Eduardo Silva Carneiro, Fernando Elias, Gabriel Eliseu, Thaise Emilio, Camila Laís Farrapo, Letícia Fernandes, Gustavo Ferreira, Joice Ferreira, Leandro Ferreira, Socorro Ferreira, Marcelo Fragomeni Simon, Maria Aparecida Freitas, Queila S. García, Angelo Gilberto Manzatto, Paulo Graça, Frederico Guilherme, Eduardo Hase, Niro Higuchi, Mariana Iguatemy, Reinaldo Imbrozio Barbosa, Margarita Jaramillo, Carlos Joly, Joice Klipel, Iêda Leão do Amaral, Carolina Levis, Antonio S. Lima, Maurício Lima Dan, Aline Lopes, Herison Madeiros, William E. Magnusson, Rubens Manoel dos Santos, Beatriz Marimon, Ben Hur Marimon Junior, Roberta Marotti Martelletti Grillo, Luiz Martinelli, Simone Matias Reis, Salomão Medeiros, Milton Meira-Junior, Thiago Metzker, Paulo Morandi, Natanael Moreira do Nascimento, Magna Moura, Sandra Cristina Müller, Laszlo Nagy, Henrique Nascimento, Marcelo Nascimento, Adriano Nogueira Lima, Raimunda Oliveira de Araújo, Jhonathan Oliveira Silva, Marcelo Pansonato, Gabriel Pavan Sabino, Karla Maria Pedra de Abreu, Pablo José Francisco Pena Rodrigues, Maria Piedade, Domingos Rodrigues, José Roberto Rodrigues Pinto, Carlos Quesada, Eliana Ramos, Rafael Ramos, Priscyla Rodrigues, Thaiane Rodrigues de Sousa, Rafael Salomão, Flávia Santana, Marcos Scaranello, Rodrigo Scarton Bergamin, Juliana Schietti, Jochen Schöngart, Gustavo Schwartz, Natalino Silva, Marcos Silveira, Cristiana Simão Seixas, Marta Simbine, Ana Claudia Souza, Priscila Souza, Rodolfo Souza, Tereza Sposito, Edson Stefani Junior, Julio Daniel do Vale, Ima Célia Guimarães Vieira, Dora Villela, Marcos Vital, Haron Xaud, Katia Zanini, Charles Eugene Zartman, Nur Khalish Hafizhah Ideris, Faizah binti Hj Metali, Kamariah Abu Salim, Muhd Shahruney Saparudin, Rafizah Mat Serudin, Rahayu Sukmaria Sukri, Serge Begne, George Chuyong, Marie Noel Djuikouo, Christelle Gonmadje, Murielle Simo-Droissart, Bonaventure Sonké, Hermann Taedoumg, Lise Zemagho, Sean Thomas, Fidèle Baya, Gustavo Saiz, Javier Silva Espejo, Dexiang Chen, Alan Hamilton, Yide Li, Tushou Luo, Shukui Niu, Han Xu, Zhang Zhou, Esteban Álvarez-Dávila, Juan Carlos Andrés Escobar, Henry Arellano-Peña, Jaime Cabezas Duarte, Jhon Calderón, Lina Maria Corrales Bravo, Borish Cuadrado, Hermes Cuadros, Alvaro Duque, Luisa Fernanda Duque, Sandra Milena Espinosa, Rebeca Franke-Ante, Hernando García, Alejandro Gómez, Roy González-M., Álvaro Idárraga-Piedrahíta, Eliana Jimenez, Rubén Jurado, Wilmar López Oviedo, René López-Camacho, Omar Aurelio Melo Cruz, Irina Mendoza Polo, Edwin Paky, Karen Pérez, Angel Pijachi, Camila Pizano, Adriana Prieto, Laura Ramos, Zorayda Restrepo Correa, James Richardson, Elkin Rodríguez, Gina M. Rodriguez M., Agustín Rudas, Pablo Stevenson, Markéta Chudomelová, Martin Dancak, Radim Hédl, Stanislav Lhota, Martin Svatek, Jacques Mukinzi, Corneille Ewango, Terese Hart, Emmanuel Kasongo Yakusu, Janvier Lisingo, Jean-Remy Makana, Faustin Mbayu, Benjamin Toirambe, John Tshibamba Mukendi, Lars Kvist, Gustav Nebel, Selene Báez, Carlos Céron, Daniel M. Griffith, Juan Ernesto Guevara Andino, David Neill, Walter Palacios, Maria Cristina Peñuela-Mora, Gonzalo Rivas-Torres, Gorky Villa, Sheleme Demissie, Tadesse Gole, Techane Gonfa, Kalle Ruokolainen, Michel Baisie, Fabrice Bénédet, Wemo Betian, Vincent Bezard, Damien Bonal, Jerôme Chave, Vincent Droissart, Sylvie Gourlet-Fleury, Annette Hladik, Nicolas Labrière, Pétrus Naisso, Maxime Réjou-Méchain, Plinio Sist, Lilian Blanc, Benoit Burban, Géraldine Derroire, Aurélie Dourdain, Clement Stahl, Natacha Nssi Bengone, Eric Chezeaux, Fidèle Evouna Ondo, Vincent Medjibe, Vianet Mihindou, Lee White, Heike Culmsee, Cristabel Durán Rangel, Viviana Horna, Florian Wittmann, Stephen Adu-Bredu, Kofi Affum-Baffoe, Ernest Foli, Michael Balinga, Anand Roopsind, James Singh, Raquel Thomas, Roderick Zagt, Indu K. Murthy, Kuswata Kartawinata, Edi Mirmanto, Hari Priyadi, Ismayadi Samsoedin, Terry Sunderland, Ishak Yassir, Francesco Rovero, Barbara Vinceti, Bruno Hérault, Shin-Ichiro Aiba, Kanehiro Kitayama, Armandu Daniels, Darlington Tuagben, John T. Woods, Muhammad Fitriadi, Alexander Karolus, Kho Lip Khoon, Noreen Majalap, Colin Maycock, Reuben Nilus, Sylvester Tan, Almeida Sitoe, Indiana Coronado G., Lucas Ojo, Rafael de Assis, Axel Dalberg Poulsen, Douglas Sheil, Karen Arévalo Pezo, Hans Buttgenbach Verde, Victor Chama Moscoso, Jimmy Cesar Cordova Oroche, Fernando Cornejo Valverde, Massiel Corrales Medina, Nallaret Davila Cardozo, Jano de Rutte Corzo, Jhon del Aguila Pasquel, Gerardo Flores Llampazo, Luis Freitas, Darcy Galiano Cabrera, Roosevelt García Villacorta, Karina Garcia Cabrera, Diego García Soria, Leticia Gatica Saboya, Julio Miguel Grandez Rios, Gabriel Hidalgo Pizango, Eurídice Honorio Coronado, Isau Huamantupa-Chuquimaco, Walter Huaraca Huasco, Yuri Tomas Huillca Aedo, Jose Luis Marcelo Peña, Abel Monteagudo Mendoza, Vanesa Moreano Rodriguez, Percy Núñez Vargas, Sonia Cesarina Palacios Ramos, Nadir Pallqui Camacho, Antonio Peña Cruz, Freddy Ramirez Arevalo, José Reyna Huaymacari, Carlos Reynel Rodriguez, Marcos Antonio Ríos Paredes, Lily Rodriguez Bayona, Rocio del Pilar Rojas Gonzales, Maria Elena Rojas Peña, Norma Salinas Revilla, Yahn Carlos Soto Shareva, Raul Tupayachi Trujillo, Luis Valenzuela Gamarra, Rodolfo Vasquez Martinez, Jim Vega Arenas, Christian Amani, Suspense Averti Ifo, Yannick Bocko, Patrick Boundja, Romeo Ekoungoulou, Mireille Hockemba, Donatien Nzala, Alusine Fofanah, David Taylor, Guillermo Bañares-de Dios, Luis Cayuela, Íñigo Granzow-de la Cerda, Manuel Macía, Juliana Stropp, Maureen Playfair, Verginia Wortel, Toby Gardner, Robert Muscarella, Hari Priyadi, Ervan Rutishauser, Kuo-Jung Chao, Pantaleo Munishi, Olaf Bánki, Frans Bongers, Rene Boot, Gabriella Fredriksson, Jan Reitsma, Hans ter Steege, Tinde van Andel, Peter van de Meer, Peter van der Hout, Mark van Nieuwstadt, Bert van Ulft, Elmar Veenendaal, Ronald Vernimmen, Pieter Zuidema, Joeri Zwerts, Perpetra Akite, Robert Bitariho, Colin Chapman, Eilu Gerald, Miguel Leal, Patrick Mucunguzi, Miguel Alexiades, Timothy R. Baker, Karina Banda, Lindsay Banin, Jos Barlow, Amy Bennett, Erika Berenguer, Nicholas Berry, Neil M. Bird, George A. Blackburn, Francis Brearley, Roel Brienen, David Burslem, Lidiany Carvalho, Percival Cho, Fernanda Coelho, Murray Collins, David Coomes, Aida Cuni-Sanchez, Greta Dargie, Kyle Dexter, Mat Disney, Freddie Draper, Muying Duan, Adriane Esquivel-Muelbert, Robert Ewers, Belen Fadrique, Sophie Fauset, Ted R. Feldpausch, Filipe França, David Galbraith, Martin Gilpin, Emanuel Gloor, John Grace, Keith Hamer, David Harris, Tommaso Jucker, Michelle Kalamandeen, Bente Klitgaard, Aurora Levesley, Simon L. Lewis, Jeremy Lindsell, Gabriela Lopez-Gonzalez, Jon Lovett, Yadvinder Malhi, Toby Marthews, Emma McIntosh, Karina Melgaço, William Milliken, Edward Mitchard, Peter Moonlight, Sam Moore, Alexandra Morel, Julie Peacock, Kelvin Peh, Colin Pendry, R. Toby Pennington, Luciana de Oliveira Pereira, Carlos Peres, Oliver L. Phillips, Georgia Pickavance, Thomas Pugh, Lan Qie, Terhi Riutta, Katherine Roucoux, Casey Ryan, Tiina Sarkinen, Camila Silva Valeria, Dominick Spracklen, Suzanne Stas, Martin Sullivan, Michael Swaine, Joey Talbot, James Taplin, Geertje van der Heijden, Laura Vedovato, Simon Willcock, Mathew Williams, Luciana Alves, Patricia Alvarez Loayza, Gabriel Arellano, Cheryl Asa, Peter Ashton, Gregory Asner, Terry Brncic, Foster Brown, Robyn Burnham, Connie Clark, James Comiskey, Gabriel Damasco, Stuart Davies, Tony Di Fiore, Terry Erwin, William Farfan-Rios, Jefferson Hall, David Kenfack, Thomas Lovejoy, Roberta Martin, Olga Martha Montiel, John Pipoly, Nigel Pitman, John Poulsen, Richard Primack, Miles Silman, Marc Steininger, Varun Swamy, John Terborgh, Duncan Thomas, Peter Umunay, Maria Uriarte, Emilio Vilanova Torre, Ophelia Wang, Kenneth Young, Gerardo A. Aymard C., Lionel Hernández, Rafael Herrera Fernández, Hirma Ramírez-Angulo, Pedro Salcedo, Elio Sanoja, Julio Serrano, Armando Torres-Lezama, Tinh Cong Le, Trai Trong Le, Hieu Dang Tra
Azitromicina inibe a infecção por Toxoplasma gondii em oculares de fetos e reduz o parasitismo na infecção congênita e adquirida em modelo experimental de Calomys callosus
Toxoplasma gondii is an obligatory intracelullar parasite of large geographical distribution
that causes severe sequelae to fetuses of mothers infected for the first time during
pregnancy and in immunossuppressed adults. The drugs most frequently used for the
treatment of toxoplasmosis are a combination of sulfadiazine and pirimethamine plus
folinic acid. However, these drugs present severe side effects and currently their efficacy is
under study. Other medicines that are considered as alternatives for the treatment are
clindamycin, atovaquone and azithromycin. The latter has demonstrated to be effective
againts both tachyzoites and bradyzoites in vitro with lesser side effects in clinical practice.
In this study we tested the efficacy of azithromycin on the reduction of vertical
transmission of Toxoplasma, by the analyses of fetal eyes of Calomys callosus, as well as
the acquired adult infection analyzing brains of the mothers and adult males. For the
analysis of the treatment on the vertical transmission, females of C. callosus were
inoculated perorally with 20 cysts of the ME49 strain of T. gondii on the first day of
pregnancy and then received the different treatments. Fetuses and mothers brains were
collected on days 15, 17 e 19 of gestation/infection. Females were sorted into three
treatment groups: control (vehicle), azithromycin (300mg/kg/dia) and the association of the
drugs sulfadiazine (100 or 75 mg/Kg/day), pyrimethamine (100 or 50mg/Kg/day) and
folinic acid (15mg/Kg/day). The drugs were administered orally starting at different days
post-infection and animals were bled on the first day of pregnancy and on the day of
sacrifice to perform ELISA tests for the detection of anti-T. gondii antibodies. For the
analyses of acquired infection, adult males were infected and treated using the same drugs
as the females, for either the same or longer periods. After treatment, animals were
sacrificed and the brains were collected from the adults and eyes from the fetuses. All
samples were processed for immunohistochemistry, using a policlonal antibody against
T.gondii , while one of the eyes of fetuses from day 19 were also processed for real time
PCR detection of parasite DNA. Parasite load was significantly reduced in brain tissues of
females treated with azithromycin when compared to SPAf treatment. In fetuses of
azithromycin-treated mothers no parasites were detected in the eyes analyzed. No
difference was seen in parasite load when the SPAf-treated group was compared to the
control group. In brain tissues of adult males, there was significant reduction in parasite
numbers in the azithromycin-treated animals. Our study demonstrated a good efficacy of
azithromycin for the treatment of pregnant females, diminishing fetal ocular infection, as
well as for the treatment of adult animals, representing an alternative choice for the
treatment of toxoplasmosis.Universidade Federal de UberlândiaMestre em Imunologia e Parasitologia AplicadasToxoplasma gondii é um parasita intracelular obrigatório, amplamente distribuído e que
causa danos graves aos fetos quando são transmitidos durante a gestação e em adultos
imunossuprimidos. As drogas mais utilizadas para o tratamento da toxoplasmose são a
combinação de medicamentos: sulfadiazina, pirimetamina e ácido folínico. Entretanto,
essas drogas demonstram graves efeitos colaterais e, atualmente, a sua eficácia é bastante
discutida na literatura. Outros medicamentos são tidos como alternativos ao tratamento da
toxoplasmose adquirida, dentre eles a clindamicina, a atovaquona e a azitromicina. Essa
última demonstra-se eficaz no combate as formas taquizoítas e bradizoítas, in vitro , do
parasita e apresenta-se com poucos efeitos colaterais na prática clínica. Neste estudo
testamos a eficácia da azitromicina na redução da transmissão congênita de Toxoplasma
analisando olhos de fetos de Calomys callosus, bem como da infecção adquirida em
adultos através da análise do tecido cerebral de fêmeas prenhes e de machos
imunocompetentes. Para a avaliação da infecção vertical, fêmeas de C. callosus foram
inoculadas, oralmente, com 20 cistos da cepa ME49 de T. gondii no 1º dia de gestação e
tratadas com os differentes protocolos. Os fetos foram coletados nos dias 15, 17 e 19 de
gestação-infecção materna. As fêmeas foram divididas em três grupos de tratamento: PBS,
azitromicina (300mg/Kg/dia) e a combinação (SPAf) de sulfadiazina (100 ou 75
mg/Kg/dia), pirimetamina (100 ou 50mg/Kg/dia) e ácido folínico (15mg/Kg/dia). Os
medicamentos foram administrados oralmente em diferentes dias após a infecção. As
fêmeas foram sangradas no primeiro dia de gestação e no dia do sacrifício para a realização
de teste ELISA para confirmar soroconversão. Para análise da infecção adquirida, machos
de C. callosus seguiram o mesmo protocolo de infecção e tratamento das fêmeas grávidas,
mas por tempos diferentes. Os cérebros maternos e de machos adultos, bem como os olhos
dos fetos foram dissecados e embebidos em parafina para análise por imunohistoquímica
usando anticorpo policlonal anti-T. gondii. Um dos olhos de fetos sacrificados no 19º dia
foi utilizado para a detecção de DNA do parasita pela técnica de PCR em tempo real. A
quantidade de parasitas estava significantemente reduzida em tecido cerebral das fêmeas
tratadas com azitromicina quando comparados a SPAf ou com veículo. Nas regiões
oculares fetais, não foram detectados parasitas nos animais tratados com azitromicina. Não
houve diferença na infecção ocular fetal entre os animais tratados com a SPAf ou PBS. Na
infecção adquirida, a azitromicina reduziu a quantidade de parasitas em vacúolos
parasitóforos e estruturas como cistos. Nosso trabalho demonstrou a eficácia da
azitromicina no combate à infecção ocular congênita, na redução da carga parasitária nos
cérebros maternos e de machos adultos imunocompetentes mostrando ser uma possível
alternativa no tratamento da toxoplasmose
Eficácia do tratamento da Azitromicina na transmissão congênita de Toxoplasma gondii em Calomys callosus
Trabalho de Conclusão de Curso (Graduação)Toxoplasma gondii é um protozoário parasita intracelular obrigatório capaz de infectar uma grande variedade de hospedeiros. Quando transmitidos durante a gestação, as conseqüências para o feto são geralmente graves, especialmente no sistema nervoso central, onde ocorre inflamação e necrose, deixando lesões irreversíveis. A droga mais utilizada no tratamento da toxoplasmose durante a gestação é a espiramicina, que tem diversos efeitos colaterais. O propósito deste estudo foi testar se o macrolideo azitromicina era capaz de reduzir a transmissão plancentária de T gondii em modelo experimental no roedor Calomys callosus. Fêmeas de C. callosus foram inoculadas por via oral com 20 cistos da cepa ME-49 de T gondii no dia da fertilização, determinado pela presença da rolha vaginal. Fetos e placentas foram coletados do 15° ao 20° dia de gestação, sendo que cérebro e olhos foram fixados em formalina e embebidos em parafina para análise imunohistoquímica usando anticorpo monoclonal contra TgSAG1. O cérebro e o figado, assim como a placenta, foram macerados e inoculados intraperitonealmente em camundongos Swiss para análise sorológica. No grupo controle, Toxoplasma foi detectado em todos os cortes de cérebro e em cortes oculares dos dias gestacionais 17 e 19, enquanto que no grupo tratado com azitromicina, só houve detecção de taquizoitas em cortes de cérebro do dia gestacional 16, sendo todos os cortes oculares negativos para a presença do parasita. No modelo estudado, o tratamento de fêmeas grávidas com azitromicina diminuiu a transmissão congênita de T. gondii
Seroprevalence and risk factors for Toxoplasma gondii infection in pigs in southern Piauí
This study is aimed to assess the prevalence and risk factors associated with T. gondii infection in pigs. We evaluated 143 pigs, in 10 randomly-chosen farms located in Southern Piauí. The pig's blood serum was analyzed through ELISA in detection of anti-T. gondii antibodies. A seroprevalence of 25.5% was observed in the pigs that reacted against T. gondii antigens. The data from the records demonstrated an association with some factors such as: age, diet, type of management, breed and presence of cats in the farms with a prevalence of T. gondii. With the exception of sex, all others features represent risk factors for T. gondii infection. Furthermore, our data contributed to the understanding of the T. gondii seroprevalence in pig farms located in Southern Piauí
Lysophosphatidylcholine Triggers TLR2- and TLR4- Mediated Signaling Pathways but Counteracts LPSInduced NO Synthesis in Peritoneal Macrophages by Inhibiting NF-κB Translocation and MAPK/ERK Phosphorylation
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Previous issue date: 2013Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Bioquímica Médica. Programa de Biologia Molecular e Biotecnologia. Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular- INCT-EM. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Bioquímica Médica. Programa de Biologia Molecular e Biotecnologia. Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular- INCT-EM. Rio de Janeiro, RJ, Brasil.University of Texas at El Paso. Department of Biological Sciences. The Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Biological Sciences. The Border Biomedical Research Center. El Paso, Texas, USA / Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto. Departamento de Biologia Celular e Molecular Patogênicos. Ribeirão Preto, SP, Brasil.University of Texas at El Paso. Department of Biological Sciences. The Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Biological Sciences. The Border Biomedical Research Center. El Paso, Texas, USA / Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto. Departamento de Biologia Celular e Molecular Patogênicos. Ribeirão Preto, SP, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Biofísica Carlos Chagas Filho. Laboratório de Parasitologia Molecular. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Bioquímica Médica. Programa de Biologia Molecular e Biotecnologia. Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular- INCT-EM. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Bioquímica Médica. Programa de Biologia Molecular e Biotecnologia. Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular- INCT-EM. Rio de Janeiro, RJ, Brasil.Background: Lysophosphatidylcholine (LPC) is the main phospholipid component of oxidized low-density lipoprotein
(oxLDL) and is usually noted as a marker of several human diseases, such as atherosclerosis, cancer and diabetes.
Some studies suggest that oxLDL modulates Toll-like receptor (TLR) signaling. However, effector molecules that are
present in oxLDL particles and can trigger TLR signaling are not yet clear. LPC was previously described as an
attenuator of sepsis and as an immune suppressor. In the present study, we have evaluated the role of LPC as a
dual modulator of the TLR-mediated signaling pathway.
Methodology/Principal Findings: HEK 293A cells were transfected with TLR expression constructs and stimulated
with LPC molecules with different fatty acid chain lengths and saturation levels. All LPC molecules activated both
TLR4 and TLR2-1 signaling, as evaluated by NF-қB activation and IL-8 production. These data were confirmed by
Western blot analysis of NF-қB translocation in isolated nuclei of peritoneal murine macrophages. However, LPC
counteracted the TLR4 signaling induced by LPS. In this case, NF-қB translocation, nitric oxide (NO) synthesis and
the expression of inducible nitric oxide synthase (iNOS) were blocked. Moreover, LPC activated the MAP Kinases
p38 and JNK, but not ERK, in murine macrophages. Interestingly, LPC blocked LPS-induced ERK activation in
peritoneal macrophages but not in TLR-transfected cells.
Conclusions/Significance: The above results indicate that LPC is a dual-activity ligand molecule. It is able to trigger
a classical proinflammatory phenotype by activating TLR4- and TLR2-1-mediated signaling. However, in the
presence of classical TLR ligands, LPC counteracts some of the TLR-mediated intracellular responses, ultimately
inducing an anti-inflammatory phenotype; LPC may thus play a role in the regulation of cell immune responses and
disease progression
Number of brain cysts and survival of mice immunized with microneme proteins and infected with <i>T</i>. <i>gondii</i>.
<p>Mice immunized on days 0, 15, and 30 with the indicated preparations of TgMICs or with the vehicle (PBS) were challenged after one month (day 60) with <i>T</i>. <i>gondii</i> infection, provoked by gavage with cysts of the ME49 strain. (A) Cyst numbers were counted from whole brain homogenates of mice, harvested one month after challenge with 40 cysts. The results are expressed as means ± SD for each group. Significance is denoted as *p < 0.05, compared to the PBS group. (B) Survival curves of mice that were challenged with 80 cysts of the ME49 strain and observed daily for mortality. Data are representative of six experiments with similar results.</p