21 research outputs found
Avaliação da Resistência ao Cisalhamento Por Extrusão, Push-out, de Pinos de Fibra de Vidro Cimentados à Dentina Radicular de Dente Bovinos Com Diferentes Cimentos Resinosos - Estudo in Vitro
Devido a necessidade do conhecimento sobre a resistência de união dos agentes cimentantes resinosos empregados para retenção de pinos intra-radiculares, este estudo in-vitro, teve o objetivo de avaliar a adesão de diferentes cimentos resinosos as paredes dos condutos radiculares, proveniente da cimentação adesiva de pinos de fibra de vidro, verificando a resistência de união, pelo teste de push-out, nas diferentes regiões do canal. Para esse estudo foram utilizados 36 raízes de dentes bovinos divididos em 3 grupos, onde foram cimentados Pinos de Fibra de Vidro Reforpost n º 3, para o Grupo A: usou PanaviaF/ ED Primer , Grupo B: RelyX ARC/ Scotchbond Multi-plus e Grupo C: RelyX Unicem , feita a cimentação dos pinos os espécimes foram preparados para ensaio mecânico de push-out nos diferentes terços radiculares. Para analise estatistica utilizou-se o metodo de Kruskal Wallis para comparação das medias e para identificar os Grupos que diferem dentro de cada terço usou-se o teste de Mann Whitney., encontramos que para todos os grupos a força adesiva no terço cervical foram semelhante, para o terço médio o Grupo B e C foram estatisticamente semelhantes e ambos superiores ao Grupo A, e para o terço apical o Grupos B foi superior ao Grupo A e ambos apresentaram valores menores que o Grupo C, que teve uma uniformidade na qualidade adesivas nas diferentes profundidades da raiz, já o grupo A foi apresentou melhores valores no terço cervical, sendo os terços médio e apical semelhantes e ambos inferiores ao terço cervical e para o grupo B o terço cervical foi superior ao apical e ambos semelhantes ao terço médio (p≤0,05). Concluímos com o estudo que o tipo de cimento utilizado influenciou na qualidade adesiva, sendo que aqueles que necessitam de tratamento dentinário prévio a adesão foram influenciados pela profundidade do canal, diminuindo a adesão ao se aproximar das regiões mais apicais, diferentemente do cimento auto-adesivo que apresentou valores de adesão uniforme
Jaboticaba (Myrciaria jaboticaba) powder consumption improves the metabolic profile and regulates gut microbiome composition in high-fat diet-fed mice
The consumption of a high-fat diet can cause metabolic syndrome and induces host gut microbial dysbiosis and non-alcoholic fatty liver disease (NAFLD). We evaluated the effect of polyphenol-rich jaboticaba peel and seed powder (JPSP) on the gut microbial community composition and liver health in a mouse model of NAFLD. Three-month-old C57BL/6 J male mice, received either a control (C, 10% of lipids as energy, n = 16) or high-fat (HF, 50% of lipids as energy, n = 64) diet for nine weeks. The HF mice were randomly subdivided into four groups (n = 16 in each group), three of which (HF-J5, HF-J10, and HF-J15) were supplemented with dietary JPSP for four weeks (5%, 10%, and 15%, respectively). In addition to attenuating weight gain, JPSP consumption improved dyslipidemia and insulin resistance. In a dose-dependent manner, JPSP consumption ameliorated the expression of hepatic lipogenesis genes (AMPK, SREBP-1, HGMCoA, and ABCG8). The effects on the microbial community structure were determined in all JPSP-supplemented groups; however, the HF-J10 and HF-J15 diets led to a drastic depletion in the species of numerous bacterial families (Bifidobacteriaceae, Mogibacteriaceae, Christensenellaceae, Clostridiaceae, Dehalobacteriaceae, Peptococcaceae, Peptostreptococcaceae, and Ruminococcaceae) compared to the HF diet, some of which represented a reversal of increases associated with HF. The Lachnospiraceae and Enterobacteriaceae families and the Parabacteroides, Sutterella, Allobaculum, and Akkermansia genera were enriched more in the HF-J10 and HF-J15 groups than in the HF group. In conclusion, JPSP consumption improved obesity-related metabolic profiles and had a strong impact on the microbial community structure, thereby reversing NAFLD and decreasing its severity.This work was financially supported by Brazilian funding: FAPERJ – Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ: E-26/202.677/2018, E-26/010.002203/2019) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brazil (CAPES) – Finance code 001. Benjamin Willing was supported by the Canada Research Chair Program and his laboratory received funding from the Canadian Natural Science and Engineering Research Council (NSERC
GMOs in animal agriculture: time to consider both costs and benefits in regulatory evaluations
In 2012, genetically engineered (GE) crops were grown by 17.3 million farmers on over 170 million hectares. Over 70% of harvested GE biomass is fed to food producing animals, making them the major consumers of GE crops for the past 15 plus years. Prior to commercialization, GE crops go through an extensive regulatory evaluation. Over one hundred regulatory submissions have shown compositional equivalence, and comparable levels of safety, between GE crops and their conventional counterparts. One component of regulatory compliance is whole GE food/feed animal feeding studies. Both regulatory studies and independent peer-reviewed studies have shown that GE crops can be safely used in animal feed, and rDNA fragments have never been detected in products (e.g. milk, meat, eggs) derived from animals that consumed GE feed. Despite the fact that the scientific weight of evidence from these hundreds of studies have not revealed unique risks associated with GE feed, some groups are calling for more animal feeding studies, including long-term rodent studies and studies in target livestock species for the approval of GE crops. It is an opportune time to review the results of such studies as have been done to date to evaluate the value of the additional information obtained. Requiring long-term and target animal feeding studies would sharply increase regulatory compliance costs and prolong the regulatory process associated with the commercialization of GE crops. Such costs may impede the development of feed crops with enhanced nutritional characteristics and durability, particularly in the local varieties in small and poor developing countries. More generally it is time for regulatory evaluations to more explicitly consider both the reasonable and unique risks and benefits associated with the use of both GE plants and animals in agricultural systems, and weigh them against those associated with existing systems, and those of regulatory inaction. This would represent a shift away from a GE evaluation process that currently focuses only on risk assessment and identifying ever diminishing marginal hazards, to a regulatory approach that more objectively evaluates and communicates the likely impact of approving a new GE plant or animal on agricultural production systems
Comparison of Resin Cement Insertion Techniques for Luting Fiberglass Posts
Objective: To evaluate the effect of two insertion techniques of self-adhesive dual resin cement on the bond strength of fiberglass posts in different portions of the root. The homogeneity of the cement layer along the root canal was also evaluated. Material and Methods: The root canals of 28 bovine teeth were instrumented, filled, and 14mm-space was prepared for luting fiberglass posts (Reforpost #3, Angelus), maintaining 4mm of apical sealing. The roots were randomly allocated into two groups according to the cement insertion technique (n=14): Lentulo Drill (Dentsply/Maillefer) or Centrix syringe (Dentsply). The posts were fixed with self-adhesive resin cement (RelyX U200, 3M ESPE). After 7 days, the roots were cross-sectioned to obtain three 1.0-mm-thick samples of each third of the space prepared for the post. Two samples of each third were subjected to push-out test (0.5 mm/min; 200N) and the third specimen was used for the analysis of cementation layer homogeneity. Images of specimens (40x magnification) were assessed and classified by two calibrated examiners (Kappa = 0.87) according to the presence or absence of voids and misfit. Data were analyzed by two-way ANOVA and Pearson Chi-Square test. Results: There was no statistically significant effect of insertion technique (p=0.278) or post-space thirds (p = 0.521) on bond strength of fiberglass posts. Chi-Square test showed that cement insertion with the Lentulo drill produced more cement voids than Centrix syringe (p = 0.023). Conclusion: The cement insertion technique did not influence bond strength of fiberglass posts in bovine root dentin. The use of Centrix syringe for cement insertion is preferred since it produced more homogenous cement layer
Determination of the binding properties of p -cresyl glucuronide to human serum albumin
International audiencep-Cresyl glucuronide (p-CG) is a by-product of tyrosine metabolism that accumulates in patients with end-stage renal disease. p-CG binding to human serum albumin in physiological conditions (37 degrees C, pH 7.40) was studied by ultrafiltration (MWCO 10kDa) and data were analyzed assuming one binding site. The estimated value of the association constant was 2.77x10(3)M(-1) and a maximal stoichiometry of 3.80mol per mole. At a concentration relevant for end-stage renal patients, p-CG was 23% bound to albumin. Competition experiments, using fluorescent probes, demonstrated that p-CG did not bind to Sudlow's site I or site II. The p-CG did not interfere with the binding of p-cresyl-sulfate or indoxyl sulfate to serum albumin
Role of Natural Antioxidants from Functional Foods in Neurodegenerative and Metabolic Disorders
International audienc
Qualitative Evaluation of Scanning Electron Microscopy Methods in a Study of the Resin Cement/Dentine Adhesive Interface
The protein-bound uremic toxin p-cresyl-sulfate promotes intracellular ROS production and lipid peroxidation in 3T3-L1 adipose cells
International audiencePatients with chronic kidney disease (CKD) often exhibit increased level of oxidative stress that contribute to the deterioration of renal function and uremic complications. White adipose tissue (WAT) has been recognized as a major site of production of radical oxygen species (ROS) in the context of metabolic diseases. This study was designed to decipher whether the protein bound uremic toxin p-cresyl-sulfate (p-CS) could contribute to ROS production in WAT and promote oxidative stress. Mouse 3T3-L1 adipocytes were incubated for 2 h in culture medium containing 212 μM p-CS, a concentration chosen to mimic levels encountered in end stage renal disease patients or KCl as a control and intracellular ROS production was measured using the fluorescent probe 5-6-carboxy-2',7'-dichlorodihydrofluorescein diacetate. Oxidative insult was estimated by the measurement of malondialdehyde (MDA) content and glutathione content. The effects of probenecid (1 mM) a potent inhibitor of organic anion transporter, apocynin (1 mM) an inhibitor of NADPH oxidase or common antioxidants such as α-tocopherol (2.5 μM), ascorbate (200 μM), and N-acetylcysteine (500 μM) were further evaluated. p-CS triggered a striking increase in ROS production (+228%, p \textless 0.01), in MDA content (+214%, p \textless 0.005) and a decrease in glutathione (-47%, P \textless 0.01). Pre-treatment of cells with probenecid, apocynin or antioxidants prevented the p-CS induced ROS production and oxidative insults. These results suggest that in uremic state, the intracellular accumulation of p-CS in adipose cells could contribute, through an activation of NADPH oxidase, to the redox imbalance often reported in CKD patients