Efficacy of instrumentation techniques and irrigation regimens in reducing the bacterial population within root canals

The purpose of this study was to compare the in vitro intracanal bacterial reduction produced by using two instrumentation techniques and different irrigation methods. Root canals inoculated with Enterococcus faecalis were prepared by using the following techniques and irrigants: alternated rotary motions (ARM) technique, hand nickel-titanium files and 2.5% sodium hypochlorite (NaOCl) as irrigant; ARM technique and combined irrigation with 2.5% NaOCl and citric acid; ARM technique and combined irrigation with 2.5% NaOCl and 2% chlorhexidine gluconate; and Greater Taper rotary files, using 2.5% NaOCl as irrigant. Controls were instrumented by using the ARM technique and irrigated with sterile saline. Canals were sampled before and after preparation. After serial dilution, samples were plated onto Mitis-Salivarius agar, and the colony forming units that were grown were counted. All test techniques and solutions significantly reduced the number of bacterial cells within the root canal (p 0.05). Nonetheless, all of them were significantly more effective than the control group (p < 0.05). These findings support the importance of using antimicrobial irrigants during the chemomechanical preparation, regardless of the solutions or instrumentation techniques used

INIBIÇÃO DA INFECÇÃO in vitro DE MACRÓFAGOS POR Leishmania amazonensis POR EXTRATO E FRAÇÕES DE Chenopodium ambrosioides L.

A utilização de espécies vegetais, como Chenopodium ambrosioides L., para o tratamento da leishmaniose na terapêutica tradicional tem despertado interesse na busca de novos compostos mais eficazes e menos tóxicos. Nosso grupo demonstrou as atividades imunoestimuladora e anti-Leishmania in vivo do extrato bruto hidroalcoólico (EBH) de C. ambrosioides e efeito anti-promastigota in vitro do EBH e das suas frações. Neste trabalho, avaliou-se a atividade anti-Leishmania do EBH e suas frações acetato de etila (FAc) e clorofórmica (FCHCl3) em macrófagos infectados in vitro por Leishmania amazonensis. Foram realizados dois modelos: “proflático” e “terapêutico”. No primeiro, macrófagos peritoneais de camundongos Swiss  foram tratados com EBH, FAc ou FCHCl3 nas concentrações de 62,5µg/mL, 125µg/mL e 250µg/mL e, após 4 horas, infectados com formas promastigotas do parasito na razão de 1:10 por 24 horas. No segundo, os macrófagos foram infectados com promastigotas (1:10) e, após 4 horas, tratados com EBH, FAc ou FCHCl3 por 24 horas. Foram então realizados a quantifcação das amastigotas fagocitadas e o cálculo das taxas de infecção. No modelo “proflático”, apenas os macrófagos expostos ao EBH nas maiores concentrações apresentaram  taxas de  infecção  inferiores ao controle negativo. Entretanto, no modelo “terapêutico”, as  três concentrações de EBH e também da FAc reduziram a infecção de macrófagos em relação ao controle negativo, sendo a maior concentração do EBH mais efetiva inclusive que o controle positivo.  Em conclusão, o EBH de folhas de C. ambrosioides e a sua FAc possuem efeito terapêutico anti-Leishmania na infecção in vitro de macrófagos.Descritores: Leishmaniose; Leishmania amazonensis; Chenopodium ambrosioides.AbstractInhibit  of  in  vitro  macrophage  infection  by  Leishmania  amazonensis  by  extract  and  fractions  from Chenopodium ambrosioides L. The use of plant species such as Chenopodium ambrosioides L. for the treatment of leishmaniasis in traditional medicine has aroused interest in fnding new, more effective and less toxic compounds. Our group demonstrated the immunostimulatory and in vivo anti-Leishmania activities of the crude hydroalcoholic extract (HCE) from C. ambrosioides L. and the in vitro anti-promastigote effect of the HCE and its fractions. In this study, we evaluated the anti-Leishmania activity of the HCE and its fractions ethyl acetate (FAc) and chloroform (FCHCl3) in macrophages infected in vitro with Leishmania amazonensis. Two models, “prophylactic” and “therapeutic”, were performed. In the frst, Swiss mice peritoneal macrophages were treated with CHE, FAc or FCHCl3 in concentrations of 62,5μg/mL, 125μg/mL and 250μg/mL and, after 4 hours, infected with promastigote forms in the ratio of 1:10 for 24 hours. In the second model, the macrophages were infected with promastigotes (1:10)  and,  after 4 hours,  treated with HCE, FAc or FCHCl3 for 24 hours. Quantifcation of phagocytosed amastigotes and calculation  of  infection  rates were  then  perfomed.  In  the  “prophylactic” model,  only macrophages  exposed  to  the  highest concentrations of HCE presented  infection  rates  lower  than  the negative  control. However,  in  the  “therapeutic” model,  the three concentrations of both the HCE and FAc reduced the infection of macrophages compared to the negative control, with the highest concentration of HCE being even more effective than the positive control. In conclusion, the HCE from leaves of Chenopodium ambrosioides and its FAc have an anti-Leishmania therapeutic effect on the in vitro macrophages infection.Descriptors: Leishmaniasis. Leishmania amazonensis. Chenopodium ambrosioides

Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells.

Background: Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke. Methods: Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation. Results: We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation. Conclusions: Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development

CONTROLE DE ORIENTAÇÃO E VELOCIDADE DE CADEIRA DE RODAS POR VISÃO COMPUTACIONAL

This work proposes a computer vision system for wheelchair control based on facial coordinates and head position estimation. This work comprises the design of a low-cost motorized wheelchair, which aims to promote independence and quality of life for people who have motor difficulties to manipulate a joystick. The tests performed on the built prototype resulted in an accuracy of 87.78%, an precision of 90.00% and a sensitivity of 87.70%. Tests performed in the motorized wheelchair resulted in an average accuracy of 94.69%, average precision of 91.04% and average sensitivity of 89.38%.Este trabalho propõe um sistema de visão computacional para controle de cadeira de rodas com base em coordenadas faciais e estimativa da posição da cabeça. Este trabalho compõe o projeto de uma cadeira de rodas motorizada de baixo custo, que tem como objetivo promover independência e qualidade de vida a pessoas que possuem dificuldades motoras para manipular um joystick. Os testes realizados no protótipo construído resultaram em uma acurácia de 87,78%, a precisão de 90,00% e uma sensibilidade de 87,70%. Os testes realizados na cadeira de rodas motorizada resultaram em uma acurácia média de 94,69%, precisão média de 91,04% e sensibilidade média de 89,38%

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Industrial scale isolation, structural and spectroscopic characterization of epiisopiloturine from Pilocarpus microphyllus stapf leaves: a promising alkaloid against schistosomiasis

This paper presents an industrial scale process for extraction, purification, and isolation of epiisopiloturine (EPI) (2(3H)- Furanone,dihydro-3-(hydroxyphenylmethyl)-4-[(1-methyl-1H-imidazol-4-yl)methyl]-, [3S-[3a(R*),4b]]), which is an alkaloid from jaborandi leaves (Pilocarpus microphyllus Stapf). Additionally for the first time a set of structural and spectroscopic techniques were used to characterize this alkaloid. EPI has shown schistomicidal activity against adults and young forms, as well as the reduction of the egg laying adult worms and low toxicity to mammalian cells (in vitro). At first, the extraction of EPI was done with toluene and methylene chloride to obtain a solution that was alkalinized with ammonium carbonate. The remaining solution was treated in sequence by acidification, filtration and alkalinization. These industrial procedures are necessary in order to remove impurities and subsequent application of the high performance liquid chromatography (HPLC). The HPLC was employed also to remove other alkaloids, to obtain EPI purity higher than 98%. The viability of the method was confirmed through HPLC and electrospray mass spectrometry, that yielded a pseudo molecular ion of m/z equal to 287.1 Da. EPI structure was characterized by single crystal X-ray diffraction (XRD), 1H and 13C nuclear magnetic resonance (NMR) in deuterated methanol/chloroform solution, vibrational spectroscopy and mass coupled thermal analyses. EPI molecule presents a parallel alignment of the benzene and the methyl imidazol ring separated by an interplanar spacing of 3.758 Å indicating a π-π bond interaction. The imidazole alkaloid melts at 225°C and decomposes above 230°C under air. EPI structure was used in theoretical Density Functional Theory calculations, considering the single crystal XRD data in order to simulate the NMR, infrared and Raman spectra of the molecule, and performs the signals attribution