1,960 research outputs found
Recurrent aphthous stomatitis and Helicobacter pylori
Background: Recurrent aphthous stomatitis (RAS) is a recurrent painful ulcerative disorder that commonly affects
the oral mucosa. Local and systemic factors such as trauma, food sensitivity, nutritional deficiencies, systemic
conditions, immunological disorders and genetic polymorphisms are associated with the development of
the disease. Helicobacter pylori (H. pylori) is a gram-negative, microaerophile bacteria, that colonizes the gastric
mucosa and it was previously suggested to be involved in RAS development. In the present paper we reviewed all
previous studies that investigated the association between RAS and H. pylori.
Material and Methods: A search in Pubmed (MEDLINE) databases was made of articles published up until July
2015 using the following keywords: Helicobacter Pylori or H. pylori and RAS or Recurrent aphthous stomatitis.
Results: Fifteen experimental studies that addressed the relationship between infection with H. pylori and the
presence of RAS and three reviews, including a systematic review and a meta-analysis were included in this
review. The studies reviewed used different methods to assess this relationship, including PCR, nested PCR,
culture, ELISA and urea breath test. A large variation in the number of patients included in each study, as well as
inclusion criteria and laboratorial methods was observed. H. pylori can be detected in the oral mucosa or ulcerated
lesion of some patients with RAS. The quality of the all studies included in this review was assessed using levels
of evidence based on the University of Oxford’s Center for Evidence Based Medicine Criteria.
Conclusions: Although the eradication of the infection may affect the clinical course of the oral lesions by undetermined
mechanisms, RAS ulcers are not associated with the presence of the bacteria in the oral cavity and there
is no evidence that H. pylori infection drives RAS developmen
Identificação e controle de processos via desenvolvimentos em séries ortonormais. Parte B: controle preditivo
This paper presents an overview about predictive control schemes based on orthonormal basis function models. Different predictive control schemes based on such models are discussed, namely, linear controllers with terminal (stabilizing) constraints, robust controllers, and non-linear controllers. The discussions comprise a broad bibliographical survey on the subject as well as two case studies involving a simulated dynamic system and a real process.O presente artigo aborda o problema da seleção da estrutura de modelos em algoritmos de controle preditivo para sistemas monovariáveis. Neste sentido, apresenta a utilização de modelos com estrutura dinâmica desenvolvida através de bases de funções ortonormais, como as funções de Laguerre, Kautz ou funções ortonormais generalizadas. Os principais aspectos relacionados com esta classe de modelos no contexto de controladores preditivos lineares com restrições terminais, não lineares e robusto são discutidos e uma revisão bibliográfica é apresentada. O desempenho de malha fechada das estratégias analisadas é ilustrado através de dois casos de estudo envolvendo uma incubadora para recém nascidos e um processo simulado de polimerização isotérmica.322336Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Identificação e controle de processos via desenvolvimentos em séries ortonormais. Parte A: identificação
In this paper, an overview about the identification of dynamic systems using orthonormal basis function models, such as those based on Laguerre and Kautz functions, is presented. The mathematical foundations of these models as well as their advantages and limitations are discussed within the contexts of linear, robust, and nonlinear identification. The discussions comprise a broad bibliographical survey on the subject and a comparative analysis involving some specific model realizations, namely, linear, Volterra, fuzzy, and neural models within the orthonormal basis function framework. Theoretical and practical issues regarding the identification of these models are also presented and illustrated by means of two case studies related to a polymerization process.O presente artigo apresenta uma visão geral do estado da arte na área de identificação de sistemas utilizando modelos dinâmicos com estrutura desenvolvida através de bases de funções ortonormais, como as funções de Laguerre, Kautz ou funções ortonormais generalizadas. Discute-se as vantagens e possíveis limitações desse tipo de estrutura bem como os fundamentos matemáticos dos modelos correspondentes nos contextos de identificação linear, linear com incertezas paramétricas (identificação robusta) e não linear, incluindo uma revisão bibliográfica abrangente sobre o tema. Diferentes realizações de modelos com funções de base ortonormal, a saber, modelos lineares, de Volterra, fuzzy e neurais, são detalhadas e discutidas comparativamente em termos de capacidade de representação, parcimônia, complexidade de projeto e interpretabilidade. Aspectos práticos da identificação desses modelos são também apresentados e ilustrados através de dois casos de estudo envolvendo um processo simulado de polimerização isotérmica.301321Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Perillyl alcohol in Solid Lipid Nanoparticles (SLN-PA): Cytotoxicity and antitumor potential in sarcoma 180 mice model
Cancer is a group of diseases characterized by the uncontrolled growth of cells. These cells invade organs and tissues by extension or direct dissemination and can spread to other regions of the body.
Nanomedicine offers many possibilities to prevent the spread of cancer tissue and help cure the disease.
In this work, solid lipid nanoparticles (SLN) were used to encapsulate perillyl alcohol (PA), a volatile
monoterpene with proven anticancer activity. Encapsulation of PA into SLN (SLN-PA) is expected to
promote controlled release, increase PA bioavailability, and impair the volatility of the monoterpene.
SLN-PA prepared by high-shear homogenization showed average particle diameter around 254 nm,
polydispersity index ~ 0.35, zeta potential ~ -14.7 mV, and encapsulation efficiency 84.6%. Scanning
electron microscope analysis revealed a decrease in crystallinity, suggesting the encapsulation of PA in
the SLN, confirming the spherical shape and the loading of the monoterpene in the SLN. In vitro cytotoxicity
assays against murine fibroblasts (L929) showed that SLN-PA in both treated doses did not
induce any cytotoxicity on non-tumoral cells. In vivo antitumor effect of the SLN-PA was evaluated in
sarcoma 180-transplanted mice. The in vivo results demonstrated a significant tumor inhibition rate of
51.76 and 54.49% via intraperitoneal application of SLN-PA at doses of 100 and 200 mg/kg/day (p <
0.05), respective when compared to the negative control (dimethyl sulfoxide). Adverse side effects of
SLN-PA were not noticed in the liver, the kidney, or spleen tissue. The developed SLN-PA can be
considered as a safe approach for site-specific antitumor effect in vivo, reinterpreting new nanoparticles-
based cancer therapy.This work was supported by the Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional
de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio à Pesquisa e à Inovação
Tecnológica do Estado de Sergipe (Fapitec) and Coordenação de Aperfeiçoamento de Pessoal de Nível
Superior (CAPES). Eliana B. Souto would like to acknowledge the Portuguese Science and Technology
Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) for the project
UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
Anti-tumor efficiency of Perillylalcohol/β-Cyclodextrin inclusion complexes in a sarcoma S180-induced mice model
The low solubility and high volatility of perillyl alcohol (POH) compromise its bioavailability and potential use as chemotherapeutic drug. In this work, we have evaluated the anticancer activity of POH complexed with -cyclodextrin (-CD) using three complexation approaches. Molecular docking suggests the hydrogen-bond between POH and -cyclodextrin in molar proportion was 1:1. Thermal analysis and Fourier-transform infrared spectroscopy (FTIR) confirmed that the POH was enclosed in the -CD cavity. Also, there was a significant reduction of particle size thereof, indicating a modification of the -cyclodextrin crystals. The complexes were tested against human L929 fibroblasts after 24 h of incubation showing no signs of cytotoxicity. Concerning the histopathological results, the treatment with POH/-CD at a dose of 50 mg/kg promoted approximately 60% inhibition of tumor growth in a sarcoma S180-induced mice model and the reduction of nuclear immunoexpression of the Ki67 antigen compared to the control group. Obtained data suggest a significant reduction of cycling cells and tumor proliferation. Our results confirm that complexation of POH/-CD not only solves the problem related to the volatility of the monoterpene but also increases its efficiency as an antitumor agent.This work was supported by the Banco do Nordeste (grant FUNDECI/2016.0015), Conselho
Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio à Pesquisa e
à Inovação Tecnológica do Estado de Sergipe (Fapitec) and Coordenação de Aperfeiçoamento de
Pessoal de Nível Superior (CAPES). Eliana B. Souto would like to acknowledge the Portuguese
Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE)
for the project UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership
Agreement PT2020.info:eu-repo/semantics/publishedVersio
Cytotoxic, antitumor and toxicological profile of Passiflora alata leaf extract
Passiflora alata or passion fruit is a native flowering plant from Amazon, geographically spread from Peru to Brazil. The plant has long been used in folks medicine for its pharmacological properties and is included in the Brazilian Pharmacopoeia since 1929. The aim of this study was to evaluate the potential cytotoxic and antitumor activities of Passiflora alata leaf extract (PaLE) in S180-tumor bearing mice. The percentage of cell proliferation inhibition (% CPI) and IC50 in relation to 4 tumor cell lines were determined in PC3, K-562, HepG2 and S180 cell lines using the MTT assay. PaLE showed a CPI > 75% and greater potency (IC50 < 30 µg/mL) against PC3 and S180 cell lines. PaLE showed antitumor activity in treatments intraperitoneally (36.75% and 44.99% at doses of 100 and 150 mg/kg/day, respectively). Toxicological changes were shown in the reduced body mass associated with reduced food consumption, increased spleen mass associated with histopathological increase in the white pulp of the spleen and increased number of total leukocytes with changes in the percentage relationship between lymphocytes and neutrophils. Our outcomes corroborate the conclusion that PaLE has antitumor activity in vitro and in vivo with low toxicity.This research was funded by the Coordenação Aperfeiçoamento de Pessoal de Nivel Superior
(CAPES), Fundação de Ámparo à Pesquisa do Estado de Sergipe (FAPITEC) (PROCESSO: 88887.159533/2017-00 extração, encapsulação e caracterização de bioativos para o interesse biotecnologico), Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 301964/2019-0 Chamada 06/2019, and Chamada CNPq nº 01/2019) and by the Portuguese Science and Technology Foundation (FCT) project UIDB/04469/2020 (strategic fund).info:eu-repo/semantics/publishedVersio
Robust Expansion of Uncertain Volterra Kernels into Orthonormal Series
Abstract-This paper is concerned with the computation of uncertainty bounds for the expansion of uncertain Volterra models into an orthonormal basis of functions, such as the Laguerre or Kautz bases. This problem has already been addressed in the context of linear systems by means of an approach in which the uncertainty bounds of the expansion coefficients have been estimated from a structured set of impulse responses describing a linear uncertain process. This approach is extended here towards nonlinear Volterra models through the computation of the uncertainty bounds of the expansion coefficients from a structured set of uncertain Volterra kernels. The proposed formulation assures that the resulting model is able to represent all the original uncertainties with minimum intervals for the expansion coefficients. An example is presented to illustrate the effectiveness of the proposed formulation
Magnetoliposomes containing calcium ferrite nanoparticles for applications in breast cancer therapy
Magnetoliposomes containing calcium ferrite (CaFe2O4) nanoparticles were developed and characterized for the first time. CaFe2O4 nanoparticles were covered by a lipid bilayer or entrapped in liposomes forming, respectively, solid or aqueous magnetoliposomes as nanocarriers for new antitumor drugs. The magnetic nanoparticles were characterized by UV/Visible absorption, XRD, HR-TEM, and SQUID, exhibiting sizes of 5.2 ± 1.2 nm (from TEM) and a superparamagnetic behavior. The magnetoliposomes were characterized by DLS and TEM. The incorporation of two new potential antitumor drugs (thienopyridine derivatives) specifically active against breast cancer in these nanosystems was investigated by fluorescence emission and anisotropy. Aqueous magnetoliposomes, with hydrodynamic diameters around 130 nm, and solid magnetoliposomes with sizes of ca. 170 nm, interact with biomembranes by fusion and are able to transport the antitumor drugs with generally high encapsulation efficiencies (70%). These fully biocompatible drug-loaded magnetoliposomes can be promising as therapeutic agents in future applications of combined breast cancer therapy.This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013; UID/FIS/04650/2019), CQUM (UID/QUI/00686/2016; UID/QUI/00686/2019) and LA-26 (PEst-C/SAU/LA0026/2013), and through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by FCT, European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. The magnetic measurements were supported by projects UTAP-EXPL/NTec/0046/2017, NORTE-01-0145-FEDER-028538 e PTDC/FIS-MAC/29454/2017. The APC was also funded by FCT. B.D.C. acknowledges FCT for a PhD grant (SFRH/BD/141936/2018)
Percepções sobre risco e efeitos do uso e consumo de esteroides anabolizantes por praticantes de musculação
It is known that the design of the harm caused by the indiscriminate use of anabolic steroids is short of the potential harm that misuse can cause. Were investigated 50 men users of anabolic androgenic steroids (AAS). All participants are bodybuilders, mean age 29 years (±7). Most have completed higher education (n=12; 26.1%) or are enrolled in higher education (n=17; 37%). The highest form of knowledge to AAS was for gym colleagues (n=10; 20%) and 17 (34%) show more than one. Twenty-nine (58%) received parenteral AAS, 46.5% (n=20) self-made application and the most frequently EAA cited were Durateston (n= 39; 78%) and Deca-Durabolin (n=38; 76%). Twenty six (59.1%) surveyed said they had used AAS for veterinary use. For 64% (n=32) of the participants have a physical thinner was the main justification for the use of AAS; the positive effect most noticeable was the improvement of athletic performance. Thus it appears that individuals who use AAS have, to share the risks of misuse, and that prevention campaigns should go beyond to warn of the harmful effects of AAS use
- …