Leishmania Parasites Drive PD-L1 Expression in Mice and Human Neutrophils With Suppressor Capacity

Neutrophils play an important role in the outcome of leishmaniasis, contributing either to exacerbating or controlling the progression of infection, a dual effect whose underlying mechanisms are not clear. We recently reported that CD4+ and CD8+ T cells, and dendritic cells of Leishmania amazonensis-infected mice present high expression of PD-1 and PD-L1, respectively. Given that the PD-1/PD-L1 interaction may promote cellular dysfunction, and that neutrophils could interact with T cells during infection, we investigated here the levels of PD-L1 in neutrophils exposed to Leishmania parasites. We found that both, promastigotes and amastigotes of L. amazonensis induced the expression of PD-L1 in the human and murine neutrophils that internalized these parasites in vitro. PD-L1-expressing neutrophils were also observed in the ear lesions and the draining lymph nodes of L. amazonensis-infected mice, assessed through cell cytometry and intravital microscopy. Moreover, expression of PD-L1 progressively increased in neutrophils from ear lesions as the disease evolved to the chronic phase. Co-culture of infected neutrophils with in vitro activated CD8+ T cells inhibits IFN-γ production by a mechanism dependent on PD-1 and PD-L1. Importantly, we demonstrated that in vitro infection of human neutrophils by L braziliensis induced PD-L1+ expression and also PD-L1+ neutrophils were detected in the lesions of patients with cutaneous leishmaniasis. Taken together, these findings suggest that the Leishmania parasite increases the expression of PD-L1 in neutrophils with suppressor capacity, which could favor the parasite survival through impairing the immune response

Estudo de associaçăo de variaçőes dos genes BCHE (Butirilcolinesterase) e GHRL (Grelina) com obesidade /

Orientadora : Eleidi A. Chautard Freire MaiaCo-orientador : Ricardo L. R. de SouzaDissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Cięncias Biológicas, Programa de Pós-Graduaçăo em Genética. Defesa: Curitiba, 2008Inclui bibliografi

Avalia??o microsc?pica e pesquisa de sujidades em amostras comerciais de or?gano (Origanum vulgare L.), salsa (Petroselinum sativum Hoffim.) e chimichurri.

Entende-se por condimentos e especiarias, produtos naturais de origem vegetal ou ? sua mistura, podendo apresentar-se inteiros, fragmentados ou em p?. Devido ? sua origem no campo e forma de processamento, pesquisas demonstram a incid?ncia de sujidades nesta mat?ria prima. Dessa forma, o objetivo deste trabalho foi avaliar microscopicamente amostras de or?gano, salsa e chimichurri comercializados na cidade de Ouro Preto, Minas Gerais. As amostras foram submetidas aos m?todos de desengorduramento e descolora??o, e posteriormente, foram visualizadas em estereosc?pio e microsc?pio ?tico. Foram utilizadas quatro amostras distintas de cada condimento: duas marcas comerciais embaladas, e duas comercializadas a granel. Em todas elas, foi constatada a presen?a de sujidades leves, como pelos e fragmentos de insetos, e sujidades pesadas, como areia, pedras e acr?lico. Com rela??o ? presen?a de insetos e seus fragmentos, todas as amostras estavam dentro dos limites estabelecidos pela legisla??o vigente. No entanto, seis amostras foram classificadas como em desacordo ao regulamento, por apresentarem sujidades n?o previstas. Em uma amostra de or?gano, foi detectada a presen?a de outras esp?cies vegetais, caracterizando uma poss?vel fraude, uma vez que sua presen?a n?o foi declarada no r?tulo.Condiments and spices are natural vegetable products, marketed alone or in a mixture, whole, fragmented or powdered. Due to their origin in the field and processing form, researches have been demonstrating incidence of soils in these products. Thus, this work aimed evaluates microscopically samples of oregano, parsley and chimichurri marketed in Ouro Preto, Minas Gerais. The samples were submitted to degreasing and discoloration methods, and then, stereoscopic and optical microscope visualization. Four different samples of each condiment were used: two packaged trade marks, and two commercialized in bulk. In all of them, the presence of light soils, such as hair and insects? fragments, and heavy soils, such as sand, stones and acrylic, were observed. Regarding the presence of insects and their fragments, all samples were within the limits established by current legislation, however, six samples were classified as in disagreement, because they presented soil with aren?t covered by legislation. In a sample of oregano, it was detected other plant species, characterizing a possible fraud, since its presence wasn?t declared on the label

Effect of venlafaxine on bone loss associated with ligature-induced periodontitis in Wistar rats

<p>Abstract</p> <p>Background</p> <p>The present study investigated the effects of venlafaxine, an antidepressant drug with immunoregulatory properties on the inflammatory response and bone loss associated with experimental periodontal disease (EPD).</p> <p>Materials and Methods</p> <p>Wistar rats were subjected to a ligature placement around the second upper left molar. The treated groups received orally venlafaxine (10 or 50 mg/kg) one hour before the experimental periodontal disease induction and daily for 10 days. Vehicle-treated experimental periodontal disease and a sham-operated (SO) controls were included. Bone loss was analyzed morphometrically and histopathological analysis was based on cell influx, alveolar bone, and cementum integrity. Lipid peroxidation quantification and immunohistochemistry to TNF-α and iNOS were performed.</p> <p>Results</p> <p>Experimental periodontal disease rats showed an intense bone loss compared to SO ones (SO = 1.61 ± 1.36; EPD = 4.47 ± 1.98 mm, p < 0.001) and evidenced increased cellular infiltration and immunoreactivity for TNF-α and iNOS. Venlafaxine treatment while at low dose (10 mg/kg) afforded no significant protection against bone loss (3.25 ± 1.26 mm), a high dose (50 mg/kg) caused significantly enhanced bone loss (6.81 ± 3.31 mm, p < 0.05). Venlafaxine effectively decreased the lipid peroxidation but showed no significant change in TNF-α or iNOS immunoreactivity.</p> <p>Conclusion</p> <p>The increased bone loss associated with high dose venlafaxine may possibly be a result of synaptic inhibition of serotonin uptake.</p

Combined Treatment of Heterocyclic Analogues and Benznidazole upon Trypanosoma cruzi In Vivo

Chagas disease caused by Trypanosoma cruzi is an important cause of mortality and morbidity in Latin America but no vaccines or safe chemotherapeutic agents are available. Combined therapy is envisioned as an ideal approach since it may enhance efficacy by acting upon different cellular targets, may reduce toxicity and minimize the risk of drug resistance. Therefore, we investigated the activity of benznidazole (Bz) in combination with the diamidine prodrug DB289 and in combination with the arylimidamide DB766 upon T. cruzi infection in vivo. The oral treatment of T.cruzi-infected mice with DB289 and Benznidazole (Bz) alone reduced the number of circulating parasites compared with untreated mice by about 70% and 90%, respectively. However, the combination of these two compounds decreased the parasitemia by 99% and protected against animal mortality by 100%, but without providing a parasitological cure. When Bz (p.o) was combined with DB766 (via ip route), at least a 99.5% decrease in parasitemia levels was observed. DB766+Bz also provided 100% protection against mice mortality while Bz alone provided about 87% protection. This combined therapy also reduced the tissular lesions induced by T. cruzi infection: Bz alone reduced GPT and CK plasma levels by about 12% and 78% compared to untreated mice group, the combination of Bz with DB766 resulted in a reduction of GPT and CK plasma levels of 56% and 91%. Cure assessment through hemocultive and PCR approaches showed that Bz did not provide a parasitological cure, however, DB766 alone or associated with Bz cured ≥13% of surviving animals

Spatial point analysis based on dengue surveys at household level in central Brazil

<p>Abstract</p> <p>Background</p> <p>Dengue virus (DENV) affects nonimunne human populations in tropical and subtropical regions. In the Americas, dengue has drastically increased in the last two decades and Brazil is considered one of the most affected countries. The high frequency of asymptomatic infection makes difficult to estimate prevalence of infection using registered cases and to locate high risk intra-urban area at population level. The goal of this spatial point analysis was to identify potential high-risk intra-urban areas of dengue, using data collected at household level from surveys.</p> <p>Methods</p> <p>Two household surveys took place in the city of Goiania (~1.1 million population), Central Brazil in the year 2001 and 2002. First survey screened 1,586 asymptomatic individuals older than 5 years of age. Second survey 2,906 asymptomatic volunteers, same age-groups, were selected by multistage sampling (census tracts; blocks; households) using available digital maps. Sera from participants were tested by dengue virus-specific IgM/IgG by EIA. A Generalized Additive Model (GAM) was used to detect the spatial varying risk over the region. Initially without any fixed covariates, to depict the overall risk map, followed by a model including the main covariates and the year, where the resulting maps show the risk associated with living place, controlled for the individual risk factors. This method has the advantage to generate smoothed risk factors maps, adjusted by socio-demographic covariates.</p> <p>Results</p> <p>The prevalence of antibody against dengue infection was 37.3% (95%CI [35.5–39.1]) in the year 2002; 7.8% increase in one-year interval. The spatial variation in risk of dengue infection significantly changed when comparing 2001 with 2002, (ORadjusted = 1.35; p < 0.001), while controlling for potential confounders using GAM model. Also increasing age and low education levels were associated with dengue infection.</p> <p>Conclusion</p> <p>This study showed spatial heterogeneity in the risk areas of dengue when using a spatial multivariate approach in a short time interval. Data from household surveys pointed out that low prevalence areas in 2001 surveys shifted to high-risk area in consecutive year. This mapping of dengue risks should give insights for control interventions in urban areas.</p