Humoral and cellular immune responses in mice against secreted and somatic antigens from a Corynebacterium pseudotuberculosis attenuated strain: Immune response against a C. pseudotuberculosis strain.

BACKGROUND: Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis (CL), a chronic disease that affects goats and sheep. CL is characterized by the formation of granulomas in lymph nodes and other organs, such as the lungs and liver. Current knowledge of CL pathogenesis indicates that the induction of humoral and cellular immune responses are fundamental to disease control. The aim of this study was to evaluate the humoral and cellular immune responses in BALB/c mice inoculated with a C. pseudotuberculosis strain isolated in the state of Bahia, Brazil. RESULTS: The lymphocyte proliferation and in vitro production of IFN-γ, IL-4, IL-10, IL-12 and nitric oxide by spleen cells stimulated with secreted and somatic antigens from the studied strain were evaluated. IgG subclasses were also analyzed. Results showed a significant increase of Th1-profile cytokines after 60 days post-inoculation, as well as an important humoral response, represented by high levels of IgG2a and IgG1 against C. pseudotuberculosis. CONCLUSION: The T1 strain of C. pseudotuberculosis was shown to induce humoral and cellular immune responses in BALB/c mice, but, even at a dosage of 1x10(7) CFU, no signs of the disease were observed.

BRCA1 and BRCA2 rearrangements in Brazilian individuals with Hereditary Breast and Ovarian Cancer Syndrome.

Approximately 5-10% of breast cancers are caused by germline mutations in high penetrance predisposition genes. Among these, BRCA1 and BRCA2, which are associated with the Hereditary Breast and Ovarian Cancer (HBOC) syndrome, are the most frequently affected genes. Recent studies confirm that gene rearrangements, especially in BRCA1, are responsible for a significant proportion of mutations in certain populations. In this study we determined the prevalence of BRCA rearrangements in 145 unrelated Brazilian individuals at risk for HBOC syndrome who had not been previously tested for BRCA mutations. Using Multiplex Ligation-dependent Probe Amplification (MLPA) and a specific PCR-based protocol to identify a Portuguese founder BRCA2 mutation, we identified two (1,4%) individuals with germline BRCA1 rearrangements (c.547+240_5193+178del and c.4675+467_5075-990del) and three probands with the c.156_157insAlu founder BRCA2 rearrangement. Furthermore, two families with false positive MLPA results were shown to carry a deleterious point mutation at the probe binding site. This study comprises the largest Brazilian series of HBOC families tested for BRCA1 and BRCA2 rearrangements to date and includes patients from three regions of the country. The overall observed rearrangement frequency of 3.44% indicates that rearrangements are relatively uncommon in the admixed population of Brazil.

Flavonoids from the Brazilian plant Croton betulaster inhibit the growth of human glioblastoma cells and induce apoptosis

Abstract This study investigated the effects of the flavonoids 5-hydroxy-7,4′-dimethoxyflavone, casticin, and penduletin, isolated from Croton betulaster Müll Arg., Euphorbiaceae, a plant utilized in popular medicine in Brazil, on the growth and viability of the human glioblastoma cell line GL-15. We observed that 5-hydroxy-7,4′-dimethoxyflavone and casticin were not toxic to GL-15 cells after 24 h of exposure. However, casticin and penduletin inhibited the metabolic activity of glioblastoma cells significantly at a concentration of 10 µM (p ≤ 0.05). Flavonoids casticin and penduletin also induced a significant and dose-dependent growth inhibition beginning at 24 h of exposure, and the most potent flavonoid was penduletin. It was also observed that penduletin and casticin induced an enlargement of the cell body and a reduction of cellular processes, accompanied by changes in the pattern of expression of the cytoskeletal protein vimentin. Signs of apoptosis, such as the externalization of membrane phosphatidyl serine residues, nuclear condensation, and fragmentation, were also detected in cells treated with 50–100 µM flavonoids. Our results indicate that flavonoids extracted from C. betulaster present antitumoral activity to glioblastoma cells, with penduletin proving to be the most potent of the tested flavonoids. Our results also suggest that these molecules may be promising supplementary drugs for glioblastoma treatment.

Pesquisa de interferon gama em tecido periodontal de ratos submetidos à movimentação dentária induzida / Gamma-interferon investigation in rat periodontal tissue under induced dental movement

INTRODUÇÃO: durante o tratamento ortodôntico, um processo inflamatório é induzido, desencadeando uma série de eventos bioquímicos que resultam na movimentação dentária. Estímulos como a hipóxia e a deformação mecânica são os principais fatores responsáveis pela quebra da homeostasia celular, resultando em estresse e liberação de diversos mediadores importantes para o movimento do dente. Para que a remodelação óssea ocorra durante o tratamento ortodôntico, fatores reguladores,como subprodutos do ácido araquidônico e citocinas,são liberados.Ao interferon gama (INF-γ , uma citocina principal liberada após a indução da resposta imune adaptativa, é atribuída a função de atrair os macrófagos, que auxiliam na remoção de restos celulares e promovem a cicatrização e reorganização das áreas com inflamação. OBJETIVO: visto que alguns aspectos biológicos que permeiam a movimentação dentária ainda não estão totalmente esclarecidos, procurou-se, neste trabalho, verificar a expressão do INF-γ por células do periodonto de ratos submetidos à movimentação ortodôntica. MÉTODOS: a amostra foi constituída por nove ratos, cujos primeiros molares superiores direitos foram movimentados com uma força de 0,5N, por 3, 7 e 14 dias. Os molares esquerdos desempenharam o papel de grupo controle. RESULTADOS: através da imunohistoquímica, foi verificada a ausência de expressão de INF-γ na quase totalidade dos tecidos estudados,tanto no lado de pressão quanto no lado de tração.

INTRODUCTION: During the orthodontic treatment, an inflammatory process is induced, triggering series of biochemical events that results in dental movement. Stimuli such as hypoxia and mechanical deformation are the main factors responsible for the breaking of cell homeostasis, resulting in stress and liberation of several important mediators for tooth movement. To occur osseous remodeling during orthodontic treatments, regulating factors such as sub products of arachidonic acid and cytokines are released. To interferon-gamma (INF-γ ), a main cytokine released after induction of adaptive immune response, is attributed the function of attracting the macrophages, which aids in removing cell rests and promote healing and reorganization of the inflamed areas. AIM: Given that some biological aspects that permeate dental movement are not yet fully clear, we aimed in this study to investigate INF-γ expression in the periodontium of rats under orthodontic movement. METHODS: The sample was composed of 9 rats, whose first upper right molars were moved with a force of 0,5N, for 3, 7 and 14 days. The left molars were used as controls. RESULTS: Through immunohistochemistry, we verified the absence of INF-γ expression in almost all the studied tissues, in both the traction and pressure sides.