14 research outputs found
The Liver Plays a Major Role in Clearance and Destruction of Blood Trypomastigotes in Trypanosoma cruzi Chronically Infected Mice
Intravenous challenge with Trypanosoma cruzi can be used to investigate the process and consequences of blood parasite clearance in experimental Chagas disease. One hour after intravenous challenge of chronically infected mice with 5Ă106 trypomastigotes, the liver constituted a major site of parasite accumulation, as revealed by PCR. Intact parasites and/or parasite remnants were visualized at this time point scattered in the liver parenchyma. Moreover, at this time, many of liver-cleared parasites were viable, as estimated by the frequency of positive cultures, which considerably diminished after 48 h. Following clearance, the number of infiltrating cells in the hepatic tissue notably increased: initially (at 24 h) as diffuse infiltrates affecting the whole parenchyma, and at 48 h, in the form of large focal infiltrates in both the parenchyma and perivascular spaces. Phenotypic characterization of liver-infiltrating cells 24 h after challenge revealed an increase in Mac1+, CD8+ and CD4+ cells, followed by natural killer (NK) cells. As evidence that liver-infiltrating CD4+ and CD8+ cells were activated, increased frequencies of CD69+CD8+, CD69+CD4+ and CD25+CD122+CD4+ cells were observed at 24 and 48 h after challenge, and of CD25âCD122+CD4+ cells at 48 h. The major role of CD4+ cells in liver protection was suggested by data showing a very high frequency of interferon (IFN)-Îł-producing CD4+ cells 24 h after challenge. In contrast, liver CD8+ cells produced little IFN-Îł, even though they showed an enhanced potential for secreting this cytokine, as revealed by in vitro T cell receptor (TCR) stimulation. Confirming the effectiveness of the liver immune response in blood parasite control during the chronic phase of infection, no live parasites were detected in this organ 7 days after challenge
Anopheline Species Complexes in Brazil. Current Knowledge of Those Related to Malaria Transmission
First isolation of Cryptococcus gattii molecular type VGII and Cryptococcus neoformans molecular type VNI from environmental sources in the city of Belém, Parå, Brazil
Fatores associados ao acesso geogrĂĄfico aos serviços de saĂșde por pessoas com tuberculose em trĂȘs capitais do Nordeste brasileiro
First isolation of Cryptococcus gattii molecular type VGII and Cryptococcus neoformans molecular type VNI from environmental sources in the city of Belém, Parå, Brazil
Cryptococcus neoformans and Cryptococcus gattii are important
agents of meningoencephalitis in humans in the city of Belém. This
clinical data suggests that the region may be a highly endemic area for
the pathogenic Cryptococcus species within the state of ParĂĄ
(PA), Northern Brazil. Preliminary analysis of 11 environmental samples
from the city of Belém showed two positive locations, including a
hollow of a kassod tree (Senna siamea) colonized simultaneously by C.
gattii molecular type VGII and C. neoformans molecular type VNI, and a
birdcage in a commercial aviary positive for C. neoformans, molecular
type VNI. This is the first evidence of an environmental occurrence of
molecular types VNI and VGII in PA
Low frequency of human papillomavirus detection in prostate tissue from individuals from Northern Brazil
The presence of human papillomavirus (HPV) was evaluated in 65 samples
of prostate tumours and six samples of prostates with benign prostatic
hyperplasia from individuals from Northern Brazil. We used a highly
sensitive test, the Linear Array HPV Genotyping Test, to detect 37 high
and low-risk HPV types. In this study, only 3% of tumour samples showed
HPV infection. Our findings support the conclusion that, despite the
high incidence of HPV infection in the geographic regions studied, HPV
was not associated with a higher risk of prostate cancer. To our
knowledge, this is the first study evaluating the frequency of HPV
detection in prostatic tissue of individuals from Brazil
Distribuição das espĂ©cies do gĂȘnero Anopheles (Diptera, Culicidae) no Estado do MaranhĂŁo, Brasil Distribution of species from genus Anopheles (Diptera, Culicidae) in the State of MaranhĂŁo, Brazil
Estudou-se a distribuição e diversidade de espĂ©cies de Anopheles em 123 municĂpios do Estado do MaranhĂŁo, Brasil. O mĂ©todo bĂĄsico foi a captura de fĂȘmeas dentro e nos arredores das habitaçÔes humanas, em intervalos compreendidos entre 18h e 6h, no perĂodo de janeiro de 1992 a dezembro de 2001. Foram capturados 84.467 exemplares distribuĂdos em 24 espĂ©cies, com o predomĂnio de A. triannulatus sensu lato (20.788), A. darlingi (19.083), A. nuneztovari (16.884), A. albitarsis s.l. (14.352), A. aquasalis (8.202) e A. evansae (2.885). As outras 18 espĂ©cies juntas representaram apenas 2,7%. As espĂ©cies encontradas no maior nĂșmero de municĂpios foram: A. albitarsis s.l. (109 municĂpios), A. triannulatus s.l. (106), A. nuneztovari (93), A. darlingi (87) e A. evansae (64). A riqueza e a ampla distribuição das espĂ©cies de anofelinos no MaranhĂŁo concordam com a posição geogrĂĄfica do estado, entre as macrorregiĂ”es que caracterizam o Brasil, resultando em uma fauna mista, com elementos representativos dessas regiĂ”es.<br>We studied the distribution and diversity of Anopheles species in 123 counties (municipalities) in the State of MaranhĂŁo, Brazil. The basic method consisted of capturing female specimens inside and around human dwellings between 6 PM and 6 AM from January 1992 to December 2001. A total of 84,467 specimens belonging to 24 species were captured, with a predominance of A. triannulatus sensu lato (20,788), A. darlingi (19,083), A. nuneztovari (16,884), A. albitarsis s.l. (14,352), A. aquasalis (8.202), and A. evansae (2,885). The other 18 species together accounted for only 2.7% of the total. The species found in the most counties were A. albitarsis s.l. (109 counties), A. triannulatus s.l. (106), A. nuneztovari (93), A. darlingi (87), and A. evansae (64). The richness and wide distribution of anopheline species in MaranhĂŁo agree with the State's geographic position among Brazil's macro-regions, resulting in a mixed fauna with representative elements from these regions