Invasin of Yersinia pseudotuberculosis is not a polyclonal activator of mouse B lymphocytes

It is known that the invasin molecule of Yersinia pseudotuberculosis stimulates human peripheral B cells in vitro. In this work we evaluated the in vivo role of invasin as polyclonal activator of B lymphocytes in the mouse experimental model, by comparing strains of Y. pseudotuberculosis expressing invasin and isogenic inv mutants. Swiss mice were infected intravenously with two strains expressing invasin (YpIII pIB1 and an isogenic virulence plasmid-cured strain, YpIII) and with two invasin mutant strains (Yp100 pIB1 and Yp100, plasmid-cured). Spleen cells were sampled on days 7, 14, 21 and 28 after infection. Immunoglobulin (Ig)-secreting spleen cells were detected by protein A plaque assay and specific antibodies were detected in sera by ELISA. The virulent strain YPIII pIB1 (wild type) did not provoke polyclonal activation of B lymphocytes in vivo. In general, fewer Ig-secreting spleen cells of all isotypes were found in the infected animals than in the control animals. Specific IgG antibodies were detected in the sera of animals infected with all strains. The peak response occurred on the 21 st day post-infection, and the Yp100 strain provoked the highest level of these antibodies. We concluded that invasin is not a polyclonal activator of murine B cells.

Assessment of the potential clastogenic/aneugenic risk of Casearia sylvestris extract using in vivo assays

Casearia sylvestris (Flacourtiaceae) is a plant which grows in wild and has been widely used in folk medicine. In this study, clastogenic/aneugenic properties of Casearia sylvestris crude ethanolic extract were evaluated using in vivo chromosomal aberrations (CAs) and micronucleus (MN) assays in rodents. The animals were treated by gavage with 3 concentrations of the extract: 150, 300 and 500 mg/kg body weight. Bone marrow cells from Wistar rats were collected 24 h after having been submitted to the MN and CAs test. Peripheral blood cells from Swiss mice were collected 48 and 72 h after having been submitted to the MN test. The results show that C. sylvestris extract does not induce a significant increase in mean values for micronucleated polychromatic erythrocytes (MNPCE) in Swiss mice and Wistar rats, or CAs in rat bone marrow cells, at the 3 tested doses, indicating that the extract showed no clastogenic/aneugenic effects on chromosomes of the rodent cells tested. © 2007 The Japan Mendel Society.

Efeito genotóxico da artemisinina e do artesunato em células de mamíferos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Clastogenicidade e /ou aneugenicidade do hormônio androgênico nandrolona (Deca-Durabolin®) em camundongos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

CD95 (FAS) e CD178 (FASL) induzem apoptose em células CD4+ E CD8+ do sangue periférico e esplênicas em cães naturalmente infectados por Leishmania spp: Kathlenn Liezbeth Oliveira Silva. -

Pós-graduação em Ciência Animal - FMVA

Avaliação gênica da sintase de óxido nítrico endotelial (eNOS) em adultos de mesma idade e idosos hipertensos submetidos ao treinamento físico: efeito na pressão arterial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fatores de risco para hanseníase em portadores de HIV e AIDS em áreas de alta endemicidade na Amazônia

Em um país onde a hanseníase é endêmica e onde a infecção pelo HIV continua expandindo-se e interiorizando-se, espera-se encontrar um aumento da prevalência de indivíduos convivendo simultaneamente com hanseníase e HIV/aids. Com o objetivo de identificar fatores de risco para a hanseníase em portadores de HIV/aids e descrever aspectos clínicos e epidemiológicos, realizou-se um estudo de caso controle envolvendo 33 pacientes co-infectados (HIV/hanseníase) e 90 controles (HIV/aids sem hanseníase). Na amostra estudada o sexo masculino foi mais freqüente tanto nos coinfectados quanto nos controles, prevaleceram jovens e adultos jovens em ambos os grupos, Belém foi a área de procedência mais freqüente entre co-infectados e controles, não houve diferença entre renda familiar de co-infectados e controles, os pacientes co-infectados apresentavam-se, em sua maioria, no estágio de aids com grande oscilação de células CD4 periféricas. As formas clínicas mais freqüentem ente encontradas, entre os co-infectados, foram as paucibacilares, sendo a média de células CD4+ no sangue periférico significativamente maior no grupo de co-infectados. Os prováveis fatores de risco para hanseníase relacionados à infecção pelo HIV (situação clínica, situação de imunodeficiência laboratorial e co-morbidades com outras micobacterioses) não foram estatisticamente significantes. Os fatores de risco para hanseníase já descritos na literatura, tais quais contatos intradomiciliares e antecedentes familiares de hanseníase, demonstraram ser significativamente os fatores de risco para a hanseníase em indivíduos com HIV/aids, aumentando em 45 vezes e 21 vezes, respectivamente, a chance de adoecer do mal de Hansen. A recidiva não se configurou como fator de risco para a Hanseníase em pacientes HIV/aids. A maioria dos coinfectados apresentaram sinais e sintomas de hanseníase 6 meses após o inicio da TARV, confirmando estudos anteriores que sugerem ser a hanseníase uma doença associada à reconstituição imunológica no paciente portador de HIV/aids. Estudos subseqüentes fazem-se necessários para complementar este e os anteriores sobre esta tão intrigante e desafiante co-infecção.

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Compounds used to produce cloned animals are genotoxic and mutagenic in mammalian assays in vitro and in vivo

The compounds 6-dimethylaminopurine and cycloheximide promote the successful production of cloned mammals and have been used in the development of embryos produced by somatic cell nuclear transfer. This study investigated the effects of 6-dimethylaminopurine and cycloheximide in vitro, using the thiazolyl blue tetrazolium bromide colorimetric assay to assess cytotoxicity, the trypan blue exclusion assay to assess cell viability, the comet assay to assess genotoxicity, and the micronucleus test with cytokinesis block to test mutagenicity. In addition, the comet assay and the micronucleus test were also performed on peripheral blood cells of 54 male Swiss mice, 35 g each, to assess the effects of the compounds in vivo. The results indicated that both 6-dimethylaminopurine and cycloheximide, at the concentrations and doses tested, were cytotoxic in vitro and genotoxic and mutagenic in vitro and in vivo, altered the nuclear division index in vitro, but did not diminish cell viability in vitro. Considering that alterations in DNA play important roles in mutagenesis, carcinogenesis, and morphofunctional teratogenesis and reduce embryonic viability, this study indicated that 6-dimethylaminopurine and cycloheximide utilized in the process of mammalian cloning may be responsible for the low embryo viability commonly seen in nuclear transfer after implantation in utero.

Flavonoid Detection in Hydroethanolic Extract of Pouteria torta (Sapotaceae) Leaves by HPLC-DAD and the Determination of Its Mutagenic Activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genomic screening of testicular germ cell tumors from monozygotic twins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mimosa (Mimosa caesalpiniifolia) prevents oxidative DNA damage induced by cadmium exposure in Wistar rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vivo evaluation of the genetic toxicity of Rubus niveus Thunb. (Rosaceae) extract and initial screening of its potential chemoprevention against doxorubicin-induced DNA damage

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

PHF21B as a candidate tumor suppressor gene in head and neck squamous cell carcinomas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of HLA-G molecule and HLA-G gene polymorphisms in tumors, viral hepatitis, and parasitic diseases

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)