156 research outputs found
Diferenças na expressão e no descarte do TNFR1 e TNFR2 durante a infecção in vitro com o Mycobacterium bovis
A tuberculose é uma doença infecciosa causada por bactérias do gênero Mycobacterium, entre elas o M. bovis. Esses bacilos penetram no organismo principalmente pela via respiratória, sendo fagocitados pelos macrófagos alveolares. A infecção desencadeia uma cascata de moléculas inflamatórias, que visa a eliminação do patógeno. A citocina fator de necrose tumoral-alfa (TNF-α) tem um papel importante no desenvolvimento da tuberculose por induzir potente resposta inflamatória, além de regular a apoptose. O TNF-α atua por meio de dois receptores de superfície celular, o receptor 55-kDa (TNFR1) e o receptor 75-kDa (TNFR2). Esses receptores são inicialmente sintetizados como proteínas ancoradas na membrana celular, mas podem ser clivados por proteólise originando os receptores solúveis sTNFR-1 e sTNFR-2, que podem competir com os TNFRs pela ligação com o TNF-α. O objetivo desse trabalho foi analisar, in vitro, a expressão de TNFRs na superfície macrófagos J774.A1 infectados com o M. bovis BCG, além de investigar a presença de sTNFRs e TNF-α nos sobrenadantes de cultura. Os resultados mostram uma produção significativa de TNF-α e maior expressão de TNFR1 nas culturas infectadas com M. bovis, em comparação ao controle não infectado. Na presença de M. bovis as células apresentaram uma diminuição significativa na expressão do TNFR2, o que correlacionou com maior detecção de sTNFR2. Estes dados indicam que a infecção de macrófagos J774.A1 com o M. bovis induz um aumento significativo na produção de TNF-α que correlaciona com uma maior expressão de TNFR1 na superfície das células cultivadas. Os níveis de sTNFR2 foram maiores após a infecção com M. bovis e podem influenciar no acesso do TNF-α ao TNFR1, modulando a atividade biológica do TNF-α
Markers expression of cell proliferation and apoptosis in basal cell carcinoma
FUNDAMENTOS: O carcinoma basocelular é o câncer mais comum em humanos. Estudos que utilizam recursos da biologia molecular e genética, associados à histomorfologia, permitem a identificação de fatores de risco no desenvolvimento de lesões mais recorrentes e agressivas. OBJETIVO: Correlacionar a expressão dos marcadores de apoptose (p53 e Bcl-2) e proliferação celular (Ki-67 e PCNA) com os indicadores histológicos de gravidade do tumor. MÉTODOS: Estudaram-se cinco amostras das formas nodular, morfeiforme e superficial, respectivamente, e um grupo-controle com três pacientes livres de lesão. Empregou-se o teste de Mann-Whitney na comparação da expressão desses marcadores com a forma de apresentação do carcinoma basocelular. RESULTADOS: Verificou-se que a marcação do Bcl-2 foi expressiva nos CBCs ditos agressivos (variantes morfeiforme e nodular). Dos tumores estudados, 66,7% (n = 10) indicaram fortemente o p53. Nossos resultados mostram maior expressão do Ki-67 no carcinoma basocelular nodular e superficial, sem expressão nos controles. O PCNA mostrou forte marcação em todos os tipos de tumores e nos controles. CONCLUSÃO: Os achados nos permitem concluir que o Bcl-2 e o p53 apresentam tendência para diagnosticar gravidade do carcinoma basocelular e o Ki-67, por seu comportamento variável, não pode ser considerado como marcador de gravidade, assim como o PCNA, que não foi um bom marcador de proliferação celular.BACKGROUND: - Basal cell carcinoma is the most common form of human cancer. Studies employing molecular and genetic biology techniques, associated with histomorphology, lead to the identification of risk factors in the development of more recurring and aggressive lesions. OBJECTIVE - To correlate markers expression of apoptosis (p53 and bcl-2) and cell proliferation (Ki-67 and PCNA) with histological indicators of tumor severity. METHODS - Five samples of the nodular, morpheaform and superficial types of carcinoma were studied, espectively.One control group with three lesion-free patients was also included in the study. The Mann-Whitney test was used to compare these markers expression with the manifestation form of basal cell carcinoma. RESULTS - Bcl-2 expression was significant in basal cell carcinomas said to be aggressive (morpheaform and nodular types). Of the studied tumors, 66.7% (n =10) strongly expressed p53.Our results show a greater expression of Ki-67 in nodular and superficial basal cell carcinoma, with no expression in the controls. PCNA showed a strong expression in all types of tumors and in the controls. CONCLUSION - The findings allow us to conclude that Bcl-2 and p53 show a tendency to indicate the severity of basal cell carcinoma. In contrast, Ki-67, due to its variable behavior, cannot be considered a marker of severity. Also, PCNA was not a good marker of cell proliferation
Influence of examiners’ experience on the reproducibility of different gold standard techniques and histological criteria for validation of the diagnosis of occlusal caries lesions
The aims of this study were to evaluate the influence (1) of the examiner experience and (2) three histological classification criteria on the reproducibility of two gold standard techniques (non-dye or dye) for validation of the diagnosis of occlusal caries. This study comprised a sample of 210 digital images of 105 permanent teeth (105 rhodamine B dyed and 105 dyefree hemisections) and six examiners. Images were evaluated on a laptop computer and categorised according to three different histological classification criteria (proposed by Ekstrand, Lussi or Downer) and repeated in order to allow reproducibility calculation. For data analysis, the six participants were divided into two groups: G1: examiners with previous experience in histological evaluation and G2: examiners with no experience in histological evaluation. Statistical significance was set at 0.05. Results. The mean intraexaminer reproducibility values in G1 were higher than G2 in all variables. Intra-examiner reproducibility was lower for the dye-free technique in both groups. The mean values of inter-examiner reproducibility in G1 ranged from 0.60 to 0.68, and in G2 values ranged from 0.34 to 0.69. Conclusion. It can be concluded that: (1) the examiners’ experience seems to influence the reproducibility of the two gold standard techniques studied and reproducibility tends to be lower when the dye-free technique is used, and (2) the histological classification criterion does not appear to influence the reproducibility for validation of the diagnosis of occlusal caries
Biogenic Synthesis and antibiofilm efficacy of iron nanoparticles via computer simulation
The search for new drugs can be accelerated by in silico methods, i.e., fully computational methods known for their speed and low cost, allowing the analysis of a large amount of data, e.g., thousands of possible antimicrobials, in a few weeks. Molecular docking and first-principles calculations are great allies in this quest. They enable the assessment of protein-ligand interactions and can predict interactions between NPs and macromolecules to provide more information about the interactions and dynamics of NPs in biological systems. In this context, this work aims to use in silico methods to detect the formation of biogenic metallic nanoparticles from functional microalgal biomolecules of the genus Chlorella, which have chelation of metal ions as a fundamental property, and to verify the possible antibacterial biofilm efficacy using computational tools such as molecular docking. In a first analysis, it was found that the iron salt FeSO4 was the most suitable to bind the microalgal enzyme and produce its phytochelatin protein. Following this result, an analysis of the electronic structure of the phytochelatin complex with the iron salt was carried out, proving its structural modification at the nanometric level, after which an analysis of its therapeutic effect on antibiofilm activity was performed. S. aureus, a bacterium known for its multiresistant to antibiotics, these results demonstrate, through alternative in silico methods, the physiological role of phytochelatin from microalgae in the detoxification and bioremediation of metallic contaminants
Atendimento Humanizado às Mulheres em Situação de Violência: a percepção das mulheres atendidas na DEAM/Parintins, Amazonas
Este artigo analisa o atendimento da Delegacia Especializada de Parintins às mulheres em situação de violência, a partir da percepção dessas mulheres sobre os serviços desse órgão. Os dados foram obtidos através de pesquisa de campo, em janeiro de 2014, aplicando-se um roteiro semiestruturado de entrevistas em dois profissionais da delegacia – a assistente social e o escrivão; e em cinco mulheres atendidas pela instituição. A versão das mulheres evidenciou a fragilidade da estrutura física da delegacia e do atendimento a elas, pela ausência de uma equipe multidisciplinar. A observação da situação apontou registros de descaso por atendentes da DEAM, tornando-se obstáculo à continuidade dos processos. Entre os elementos contributivos destacamse ainda: a falta de espaço adequado ao atendimento e a insuficiência de conhecimento da equipe sobre as questões de gênero e violência contra a mulher. Como “porta de entrada” das denúncias torna-se evidente a carência, na Delegacia, de um atendimento humanizado às mulheres, assegurando-lhes os seus direitos
Avaliação da apoptose de macrófagos alveolares em camundongos Balb/c infectados com cepas de Mycobacterium bovis de diferentes virulências
-O Mycobacterium bovis é um membro do complexo Mycobacterium tuberculosis, um grupo de microorganismos com a capacidade de causar
tuberculose em humanos. A característica marcante das micobactérias patogênicas é a sua habilidade para sobreviver e replicar dentro do
fagossomo do macrófago. A apoptose dos macrófagos infectados pode ser uma alternativa de defesa do hospedeiro, capaz de eliminar o ambiente
de suporte para o crescimento da micobactéria. No presente trabalho investigamos, in vivo, a influência da virulência e da carga bacteriana na
ocorrência da apoptose de macrófagos durante a fase inicial da infecção pulmonar experimental por M. bovis. Camundongos BALB/c foram
infectados intratraquealmente com alta ou baixa carga das cepas virulenta (ATCC 19274) e atenuada (BCG Moreau) de M. bovis. Após 3 e 7 dias de
infecção, avaliamos a freqüência da apoptose dos macrófagos pulmonares e sua correlação com o crescimento da micobacteria e com os níveis in
situ das citocinas TNF-alfa, IL-10 e IL-12 e da proteína anti-apoptótica Bcl-2. Foi observado um aumento da apoptose de macrófagos após a infecção
com ambas as cepas. Entretanto, a cepa virulenta induziu menos apoptose do que a cepa atenuada, sendo que, no 3o dia houve redução da
apoptose na infecção com alta carga, enquanto que no 7o dia uma maior inibição ocorreu em baixa carga. Essa inibição da apoptose, promovida pela
cepa virulenta, foi associada com o aumento da produção de IL-10, redução da produção de TNF-alfa e aumento da expressão de Bcl-2. Observamos
ainda uma menor produção de IL-12 nos pontos de menor apoptose dos macrófagos o que reforça a hipótese de que a apoptose das células
infectadas contribui para o desenvolvimento de imunidade específica contra o patógeno. Em conjunto esses dados sugerem que a cepa virulenta de
M. bovis é capaz de modular a apoptose em um modo carga-dependente de acordo com suas necessidades de crescimento intracelular e
disseminação para células adjacentes
Effects of treatments for drooling on caries risk in children and adolescents with cerebral palsy
Neuromuscular impairment makes individuals with cerebral palsy (CP) more prone to drooling. Among the treatment options, there are procedures that interfere with saliva production. It is imperative to evaluate the effect of the different modalities since the reduction in salivary flow rate/production may exacerbate the risk of dental caries. The aim of this study was to compare the effects of different treatments for drooling on caries risk and salivary parameters in children and adolescents with CP. A total of 142 children and adolescents with CP, aged 6 to 18 years, were assigned to groups based on the different treatments they had received for drooling: G1?anticholinergic drugs (n = 18), G2?botulinum toxin injection (n = 16), G3?salivary glands surgery (n = 16), G4?no treatment (n = 42), and G5?non-drooling subjects (n = 50). All participants were evaluated on the Simplified Oral Hygiene Index, and for the prevalence of dental caries (decayed, missing, and filled teeth index and white spot lesions). Unstimulated whole saliva was collected, and salivary flow rate and osmolality were measured. Chi-square, ANOVA and Poisson regression were calculated. Prevalence ratios and their respective 95 % confidence intervals were obtained. The significance level was fixed at 5%. No differences were found in the decayed, missing, and filled teeth index (p = 0.128) and Simplified Oral Hygiene Index (p = 0.674) among the different groups. G3 presented significantly higher percentages of WSL (p<0.001), lower values of salivary flow rate (p<0.001), and higher values of osmolality (p<0.001). The white spot lesion prevalence ratio was higher only for G3 (Prevalence ratio = 14.36; IC 95% = 4.64-44.40; p<0.001). Children and adolescents with CP who had received surgical treatment for drooling exhibited higher number of white spot lesions because of the reduced salivary flow rate and higher salivary osmolality
Nanostructured system based on hydroxyapatite and curcumin: A promising candidate for osteosarcoma therapy:A promising candidate for osteosarcoma therapy
Osteosarcoma is the most common type of bone cancer. Despite therapeutic progress, survival rates for metastatic cases or that do not respond well to chemotherapy remain in the 30% range. In this sense, the use of nanotechnology to develop targeted and more effective therapies is a promising tool in the fight against cancer. Nanostructured hydroxyapatite, due to its biocompatibility and the wide possibility of functionalization, is an interesting material to design nanoplatforms for targeted drug delivery. These platforms have the potential to enable the use of natural substances in the fight against cancer, such as curcumin. Curcumin is a polyphenol with promising properties in treating various types of cancer, including osteosarcoma. In this work, hydroxyapatite (n-HA) nanorods synthesized by the hydrothermal method were investigated as a carrier for curcumin. For this, first-principle calculations based on the Density Functional Theory (DFT) were performed, in which the modification of curcumin (CM) with the coupling agent (3-aminopropyl) triethoxysilane (APTES) was theoretically evaluated. Curcumin was incorporated in n-HA and the drug loading stability was evaluated by leaching test. Samples were characterized by a multi-techniques approach, including Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), X-ray diffraction (XRD), X-ray fluorescence spectrometry (FRX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), zeta potential analysis (ζ), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results show that n-HAs with a 90 nm average size were obtained and successful incorporation of curcumin in the nanostructure was achieved. Cell viability and the number of osteosarcoma cells were decreased by CMAP-HA treatment. Furthermore, the stability test suggests that hydroxyapatite nanoparticles present great potential for the transportation of curcumin in the bloodstream, crediting this system for biological performance evaluations aiming at the treatment of osteosarcomas. Keywords: nanostructures, curcumin, hydroxyapatite, osteosarcoma
Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis
The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB
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