15 research outputs found
In vivo glioblastoma growth is reduced by apyrase activity in a rat glioma model
BACKGROUND: ATP is an important signalling molecule in the peripheral and central nervous system. Both glioma growth and tumor resection induces cell death, thus liberating nucleotides to the extracellular medium. Nucleotides are hydrolyzed very slowly by gliomas when compared with astrocytes and induce neuronal cell death and glioma proliferation. The objective of the present study was to test the involvement of extracellular ATP in glioblastoma growth in a rat glioma model. METHODS: To deplete the extracellular ATP, the enzyme apyrase was tested on the treatment of gliomas implanted in the rats CNS. One million glioma C6 cells in 3 microliters of DMEM/FCS were injected in the right striata of male Wistar rats, 250–270 g. After 20 days, the rats were decapitated and the brain sectioning and stained with hematoxylin and eosine. We performed immunohistochemical experiments with Ki67, CD31 and VEGF. Total RNA was isolated from cultured glioma C6 cells and the cDNA was analyzed by Real Time-PCR with primers for the NTPDase family. RESULTS: C6 glioma cells effectively have a low expression of all NTPDases investigated, in comparison with normal astrocytes. The implanted glioma co-injected with apyrase had a significant reduction in the tumor size (p < 0.05) when compared with the rats injected only with gliomas or with gliomas plus inactivated apyrase. According to the pathological analysis, the malignant gliomas induced by C6 injection and co-injected with apyrase presented a significant reduction in the mitotic index and other histological characteristics that indicate a less invasive/proliferative tumor. Reduction of proliferation induced by apyrase co-injection was confirmed by counting the percentage of Ki67 positive glioma cell nuclei. According to counts with CD31, vessel density and neoformation was higher in the C6 group 20 days after implantation. Confirming this observation, rats treated with apyrase presented less VEGF staining in comparison to the control group. CONCLUSION: These results indicate that the participation of extracellular ATP and the ecto-nucleotidases may be associated with the development of this type of brain tumor in an in vivo glioma model
Heterogeneity of linalool chemotypes of Lippia alba (Mill.) N.E.Br., based on clonal half-sib progenies
Engenharia da computação e odontologia : criação de um sistema móvel para uso no atendimento odontológico domiciliar
Engenharia da computação e odontologia : criação de um sistema móvel para uso no atendimento odontológico domiciliar
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Decitabine limits escape from MEK inhibition in uveal melanoma
MEK inhibitors (MEKi) demonstrate anti‐proliferative activity in patients with metastatic uveal melanoma, but responses are short‐lived. In the present study, we evaluated the MEKi trametinib alone and in combination with drugs targeting epigenetic regulators, including DOT1L, EZH2, LSD1, DNA methyltransferases, and histone acetyltransferases. The DNA methyltransferase inhibitor (DNMTi) decitabine effectively enhanced the anti‐proliferative activity of trametinib in cell viability, colony formation, and 3D organoid assays. RNA‐Seq analysis showed the MEKi‐DNMTi combination primarily affected the expression of genes involved in G1 and G2/2M checkpoints, cell survival, chromosome segregation and mitotic spindle. The DNMTi‐MEKi combination did not appear to induce a DNA damage response (as measured by γH2AX foci) or senescence (as measured by β‐galactosidase staining) compared to either MEKi or DNMTi alone. Instead, the combination increased expression of the CDK inhibitor p21 and the pro‐apoptotic protein BIM. In vivo, the DNMTi‐MEKi combination was more effective at suppressing growth of MP41 uveal melanoma xenografts than either drug alone. Our studies indicate that DNMTi may enhance the activity of MEKi in uveal melanoma
The nucleotide hydrolysis is altered in blood serum of streptozotocin-induced diabetic rats
Development of chitosan, gelatin and liposome film and analysis of its biocompatibility in vitro
Avaliação do impacto da exposição a agrotóxicos sobre a saúde de população rural: Vale do Taquari (RS, Brasil) Evaluation of the impact of exposure to pesticides on the health of the rural population: Vale do Taquari, State of Rio Grande do Sul (Brazil)
Este estudo transversal teve o objetivo de avaliar possível associação entre contato com agrotóxicos e prevalência de doenças crônicas em população rural do Sul do Brasil. Três municípios foram aleatoriamente escolhidos. A amostra selecionada por conveniência foi recrutada durante três meses (2005) e se compôs de 298 sujeitos de ambos os sexos, com idade entre 18 e 65 anos e que procuravam farmácia pública ou privada para a compra de medicamentos. Os dados obtidos, mediante entrevistas estruturadas, demonstraram que 68,4% dos entrevistados exerciam atividade rural, dos quais 74,8% eram membros de famílias de agricultores e tinham contato com agrotóxicos. A média de idade foi 51±16,5 anos para os entrevistados com contato com agrotóxicos e 50±17,9 anos para os sem contato. A amostra foi constituída de 36,2% por homens e 57,7% dos indivíduos que apresentavam mais de quatro anos de estudo. O contato direto ou indireto com agrotóxicos associou-se ao relato de várias doenças, sendo as neurológicas e as orais as mais prevalentes. Houve associação com relato de condições dolorosas, de modo que indivíduos com contato com agrotóxicos apresentaram em torno de duas vezes mais chances de as referirem. Os dados corroboram os da literatura e indicam a necessidade de promoção de medidas de proteção e prevenção da saúde da população rural.<br>The scope of this cross-sectional study was to assess a possible link between contact with pesticides and the prevalence of chronic disease in the rural population in the south of Brazil. Three municipalities were randomly chosen. The sample selected was recruited over three months (2005) and was composed of 298 subjects of both sexes, between 18 and 65 years of age, who frequented public or private pharmacies for the purchase of medication. Data obtained by means of structured interviews revealed that 68.4% of those interviewed worked in rural activities, and 74.8% of these were members of families working in agriculture with contact with pesticides. The average age was 51+16.5 years of age for the interviewees with contact with pesticides and 50+17.9 years for those without contact. The sample was composed of 36.2% of men, and 57.7% of the individuals had more than four years of education. Direct or indirect contact with pesticides was associated with the report of several diseases, with neurological and oral diseases being the most prevalent. There was a link with painful conditions and individuals with contact with pesticides reported twice as many diseases. The data corroborate the literature and draw attention to the need for promoting measures to protect the health of the rural population