Efeito de glucanas do fungo Caripia montagnei em modelo de inflamação intestinal induzida por tnbs em ratos Wistar e em células de carcinoma de cólon humano HT-29

Compounds derived from fungi has been the subject of many studies in order to broaden the knowledge of their bioactive potential. Polysaccharides from Caripia montagnei have been described to possess anti-inflammatory and antioxidant properties. In this study, glucans extracted from Caripia montagnei mushroom were chemically characterized and their effects evaluated at different doses and intervals of treatment. It was also described their action on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and its action on cells of the human colon carcinoma (HT-29). Compounds extracted of C. montagnei contain high level of carbohydrates (96%), low content of phenolic compounds (1.5%) and low contamination with proteins (2.5%). The (FT-IR) and (NMR) analysis showed that polysaccharides from this species of mushroom are composed of α- and β-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed a reduction of colonic lesions in all groups treated with the glucans of Caripia montagnei (GCM). GCM significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that such glucans acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01), nitric oxide (p < 0.001), and myeloperoxidase (p < 0.001). These results were confirmed microscopically by the reduction of cellular infiltration. The increase of catalase activity suggest a protective effect of GCM on colonic tissue, confirming their anti-inflammatory potential. GCM displayed cytostatic activity against HT-29 cells, causing accumulation of cells in G1 phase, blocking the cycle cell progression. Those glucans also showed ability to modulate the adhesion of HT-29 cells to Matrigel® and reduced the oxidative stress. The antiproliferative activity against HT-29 cells displayed by GCM (p <0.001) can be attributed to its cytostatic activity and induction of apoptosis by GCM

Efeito de extratos da alga marinha caulerpa mexicana em modelos de inflamação em murinos

The regulation of the inflammatory response is essential to maintain homeostasis. Several studies have been performed to search new drugs that can contribute to avoiding or minimizing an excessive inflammatory process. The aim of this study was to evaluate the effect of extracts of green algae Caulerpa mexican in models of inflammation. In mice, the model of peritonitis induced inflammatory zymosan pretreatment of mice with aqueous and methanol extracts of C. mexican was able to reduce cell migration to the peritoneal cavity. Treatment of mice with extracts of C. mexican also reduced the ear edema induced by xylene and exerted inhibitory action on the migration of leukocytes in inflammation-induced zymosan the air pouch, and timedependent for the extracts tested in the model of ulcerative colitis induced by DSS 3%, the extract methanol, but not the aqueous C. mexican, significantly reduced the clinical symptoms of colitis, as well as the production of proinflammatory cytokines in the culture of mouse colon, in the histological analysis there was a slight reduction of inflammation in the intestinal mucosa. We concluded that the administration of the extracts resulted in the reduction of cell migration to different sites as well as reducing the edema formation induced by chemical irritant. This study demonstrates for the first time the antiinflammatory effect of aqueous and methanolic extracts from green marine algae Caulerpa mexican

Estudos e projetos de filtro interdigital em microfita para aplicação prática ao transponder do satélite ITASAT

This work shows a theoretical analysis together with numerical and experimental results of transmission characteristics from the microstrip bandpass filters with different geometries. These filters are built over isotropic dielectric substrates. The numerical analysis is made by specifical commercial softwares, like Ansoft Designer and Agilent Advanced Design System (ADS). In addition to these tools, a Matlab Script was built to analyze the filters through the Finite-Difference Time-Domain (FDTD) method. The filters project focused the development of the first stage of filtering in the ITASAT s Transponder receptor, and its integration with the others systems. Some microstrip filters architectures have been studied, aiming the viability of implementation and suitable practical application for the purposes of the ITASAT Project due to its lowspace occupation in the lower UHF frequencies. The ITASAT project is a Universityexperimental project which will build a satellite to integrate the Brazilian Data Collect System s satellite constellation, with efforts of many Brazilian institutes, like for example AEB (Brazilian Spatial Agency), ITA (Technological Institute of Aeronautics), INPE/CRN (National Institute of Spatial Researches/Northeastern Regional Center) and UFRN (Federal University of Rio Grande do Norte). Comparisons were made between numerical and experimental results of all filters, where good agreements could be noticed, reaching the most of the objectives. Also, post-work improvements were suggested.

Atividades experimentais no ensino de biologia em escolas públicas do estado do Rio Grande do Norte, Brasil: caracterização geral e concepção de professores

Recent research has revealed that the majority of Biology teachers believe the practice of experimental activities as a didactical means would be the solution for the improvement of the Biology teaching-learning process. There are, however, studies which signal the lack of efficiency in such practice lessons as far as building scientific knowledge is concerned. It is also said that despite the enthusiasm on the teachers‟ part, such classes are rarely taught in high school. Several studies point pedagogical difficulties as well as nonexistence of a minimal infrastructure needed in laboratories as cause of low frequency in experimental activities. The poor teacher performance in terms of planning and development of classes; the large number of students per class; lack of financial stimulus for teachers are other reasons to be taken into account among others, in which can also be included difficulties of epistemological nature. That means an unfavorable eye of the teacher towards experimental activities. Our study aimed to clarify if such scenario is generalized in high schools throughout the state of Rio Grande do Norte Brazil. During our investigation a sample of twenty teaching institutions were used. They were divided in two groups: in the first group, five IFRN- Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte schools. Two of those in Natal, and the other three from the country side. The second group is represented by fifteen state schools belonging to the Natal metropolitan area. The objectives of the research were to label schools concerning laboratory facilities; to identify difficulties pointed by teachers when performing experiment classes, and to become familiar with the conceptions of the teachers in regarding biology experiment classes. To perform such task, a questionnaire was used as instrument of data collecting. It contained multiple choice, essay questions and a semi-structured interview with the assistance of a voice recorder. The data analysis and the in loco observation allowed the conclusion that the federal schools do present better facilities for the practice of experimental activities when compared to state schools. Another aspect pointed is the fact that teachers of federal schools have more time available for planning the experiments; they are also better paid and are given access a career development, which leads to better salaries. All those advantages however, do not show a significantly higher frequency regarding the development of experiments when compared to state school teachers. Both teachers of federal and state schools pointed infra-structure problems such as the availability of reactants, equipments and consumption supplies as main obstacle to the practice of experiments in biology classes. Such fact leads us to conclude that maybe there are other problems not covered by the questionnaire such as poor ability to plan and execute experimental activities. As far as conceptions about experimental activities, it was verified in the majority of the interviewees a inductive-empiric point of view of science possibly inherited during their academic formation and such point of view reflected on the way they plan and execute experiments with students

Efeitos do tratamento com Hidrogel na cicatrização de úlceras venosas de membros inferiores: revisão sistemática

Chronic venous disease (CVD) is evident among the chronic diseases and affects the elderly population and primarily is responsible for leg ulcers in this population. The use of dressings in the care of a venous ulcer is a fundamental part of the treatment for healing, however, evidence to assist in choosing the best dressing is scarce. The main objective of this study was to evaluate the effectiveness of treatment with hydrogel in the healing of venous ulcers using search methods, synthesis of information and statistical research through a systematic review and meta-analysis. Randomized controlled trials were selected in the following databases: CENTRAL; DARE; NHS EED; MEDLINE; EMBASE; CINAHL. Beyond these databases three websites were consulted to identify ongoing studies: ClinicalTrials.gov, OMS ICTRP e ISRCTN. The primary outcomes were analyzed: complete wound healing, incidence of wound infection and the secondary were: changes in ulcer size, time to ulcer healing, recurrence of ulcer, quality of life of participants, pain and costs of treatment. Four studies are currently included in the review with a total of 250 participants. The use of hydrogel appears to be superior to conventional dressing, gauze soaked in saline, for the healing of venous leg ulcers; 16/30 patients showed complete healing of ulcers (RR 5,33, 95%CI [1,73,16,42]). The alginate gel was shown to be more effective when compared to the hydrogel dressing in reduction of the wound area; 61,2% (± 26,2%) with alginate e 19,4% (± 24,3%) with hydrogel at the end of four weeks of treatment. Manuka honey has shown to be similar to the hydrogel dressings in percentage of area reduction. This review demonstrated that there is no evidence available about the effectiveness of the hydrogel compared to other types of dressings on the healing of venous leg ulcers of the lower limbs, thus demonstrating the need of future studies to assist health professionals in choosing the correct dressing.

Avaliação clínica do efeito da irradiação pós-opratória do laser de baixa intensidade na cicatrização de gengivoplastias em humanos

Many studies have been made to understand the process of tissular cicatrization, as well as the possible effects of laser therapy in the wound healing. However, the influence of low frequency laser irradiation in the repairing process is not completely understood. Our study has the purpose to assess clinically the effect of postoperative irradiation of the low frequency laser in humans, and the gingival repairing process postgingivoplasty performed with the extern bevel technique. Twenty-four patients with inflammatory gingival hyperplasia were enrolled in this study, which did not reduce with basic periodontal procedures, and patients with melanin pigmentation, with esthetic indications. After surgery the test group, randomly selected by a drawing, received laser application with energy density of 4 J/cm2, immediately after surgery and each 48 hours, during a week, with a total of 4 sections. The control group did not receive irradiation. The visual clinical analyses were performed by a single blind examiner, in the 2nd, 4th, 6th, 8th, 15th and 21st days post surgery. For statistic analyses of the data was used a Q-square test. Concerning the color, the results showed a better wound healing during days 6 to 8. when assessed the degree of progress of surgical wound, the results showed that the test group had a better cicatrization compared with the control group in the 2nd, 6th, 8th and 15th days post surgery, and at the 21st day both groups had the same results. Our results confirm that the laser had clinical influence in the repairing process after gingivoplasty surgery during days 2 to 15 post surgery

Estudos de adsorção de tetraciclina e cromoglicato em partículas de quitosana

Among the polymers that stand out most in recent decades, chitosan, a biopolymer with physico-chemical and biological promising properties has been the subject of a broad field of research. Chitosan comes as a great choice in the field of adsorption, due to their adsorbents properties, low cost and abundance. The presence of amino groups in its chain govern the majority of their properties and define which application a sample of chitosan may be used, so it is essential to determine their average degree of deacetylation. In this work we developed kinetic and equilibrium studies to monitor and characterize the adsorption process of two drugs, tetracycline hydrochloride and sodium cromoglycate, in chitosan particles. Kinetic models and the adsorption isotherms were applied to the experimental data. For both studies, the zeta potential analyzes were also performed. The adsorption of each drug showed distinct aspects. Through the studies developed in this work was possible to describe a kinetic model for the adsorption of tetracycline on chitosan particles, thus demonstrating that it can be described by two kinetics of adsorption, one for protonated tetracycline and another one for unprotonated tetracycline. In the adsorption of sodium cromoglycate on chitosan particles, equilibrium studies were developed at different temperatures, allowing the determination of thermodynamic parameters

Estudos de adsorção de tetraciclina em partículas de quitosana

Due to its physico-chemical and biological properties, related to the abundance and low cost of raw material, chitosan has been recognized as a material of wide application in various fields, such as in drug delivery systems. Many of these properties are associated with the presence of amino groups in its polymer chain. A proper determination of these amino groups is very important, in order to properly specify if a given chitosan sample can be used in a particular application. Thus, in this work, initially, a comparison between the determination of the deacetylation degree by conductometry and elemental analysis was carried out using a detailed analysis of error propagation. It was shown that the conductometric analysis resulted in a simple and safe method for the determining the degree of deacetylation of chitosan. Subsequently, experiments were performed to monitor and characterize the adsorption of tetracycline on chitosan particles through kinetic and equilibrium studies. The main models of kinetics and adsorption isotherms, widely used to describe the adsorption on wastewater treatment systems and the drug loading, were used to treat the experimental data. Firstly, it was shown that an apparent linear t/q(t) × t relationship did not imply in a pseudo-second-order adsorption kinetics, differently of what has been repeatedly reported in the literature. It was found that this misinterpretation can be avoided by using non-linear regression. Finally, the adsorption of tetracycline on chitosan particles was analyzed using insights obtained from theoretical analysis, and the parameters generated were used to analyze the kinetics of adsorption, the isotherm of adsorption and to ropose a mechanism of adsorption

Estudos de sorção de um corante aniônico modelo em partículas de quitosana reticulada

Textile activity results in effluents with a variety of dyes. Among the several processes for dye-uptaking from these wastewaters, sorption is one of the most effective methods, chitosan being a very promising alternative for this end. The sorption of Methyl Orange by chitosan crosslinked particles was approached using equilibrium and kinetic analyses at different pH s. Besides the standard pseudo-order analysis normally effectuated (i.e. pseudo-first-order and pseudo-second-order), a novel approach involving a pseudo-nth-order kinetics was used, nbeing determined via non-linear regression, using the Levenberg-Marquardt method. Zeta potential measurements indicated that electrostatic interactions were important for the sorption process. Regarding equilibrium experiments, data were well fitted to a hybrid Langmuir-Freundlich isotherm, and estimated Gibbs free energy of adsorption as a function of mass of dye per area of chitosan showed that the process of adsorption becomes more homogeneous as the pH of the continuous phase decreased. Considering the kinetics of sorption, although a pseudo-nth-order description yielded good fits, a kinetic equation involving diffusion adsorption phenomena was found to be more consistent in terms of a physicochemical description of the sorption process

O fator de crescimento de fibroblasto básico melhora a cicatrização de anastomoses duodenais em ratos

RESUMO: Objetivo: Avaliar as alterações histológicas, e o ganho de resistência em anastomoses duodenais tratadas com fator de crescimento de fibroblasto básico (FGFb). Métodos: Vinte ratos da raça Wistar foram submetidos a secção transversal do duodeno, seguida de anastomose. Os animais foram divididos em 4 grupos de 5 animais cada: A1 e A2 (experimentais), nos quais foi aplicado FCFb sobre a anastomose logo após seu término; e B1 e B2 (controles), nos quais foi administrada solução salina sobre a zona de anastomose. Os roedores foram mortos com superdose de anestésico, sendo A1, B1 no 5º dia e A2, B2 no 7º dia de pós-operatório. Foi feita avaliação quanto à resistência das anastomoses à pressão e análise da densidade média dos achados histopatológicos com auxílio do sistema digitalizado Image proPlus. Resultados: No grupo A1 a pressão suportada pelas anastomoses foi de 52±14,4 mmHg e no grupo A2 140±34,8 mmHg. Em B1 a pressão atingiu 33,6±15,2 mmHg e as anastomoses do grupo B2 suportaram pressão 105±30,3. No grupo A1 a densidade média dos elementos histopatológicos foi de 93±9,3 e A2 atingiu 181,8±27,6. Nos grupos de controle B1 e B2 as densidades médias foram 67,6±16,7 e 101±12,9 respectivamente. A análise estatística revelou diferença significante entre nos dados dos grupos experimentais e controles (p<0,05).Conclusão: a aplicação tópica do FCFb foi capaz de aumentar a resistência das feridas do duodeno suturadas e observadas após 5 e 7 dias de evolução. Estimulou a neovascularização, a formação de fibroblastos e de fibras colágenas, melhorando os escores histológicos em relação ao controle.

Efeito de glucanas do fungo Caripia montagnei em modelo de inflamação intestinal induzida por tnbs em ratos Wistar e em células de carcinoma de cólon humano HT-29

Compounds derived from fungi has been the subject of many studies in order to broaden the knowledge of their bioactive potential. Polysaccharides from Caripia montagnei have been described to possess anti-inflammatory and antioxidant properties. In this study, glucans extracted from Caripia montagnei mushroom were chemically characterized and their effects evaluated at different doses and intervals of treatment. It was also described their action on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and its action on cells of the human colon carcinoma (HT-29). Compounds extracted of C. montagnei contain high level of carbohydrates (96%), low content of phenolic compounds (1.5%) and low contamination with proteins (2.5%). The (FT-IR) and (NMR) analysis showed that polysaccharides from this species of mushroom are composed of α- and β-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed a reduction of colonic lesions in all groups treated with the glucans of Caripia montagnei (GCM). GCM significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that such glucans acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01), nitric oxide (p < 0.001), and myeloperoxidase (p < 0.001). These results were confirmed microscopically by the reduction of cellular infiltration. The increase of catalase activity suggest a protective effect of GCM on colonic tissue, confirming their anti-inflammatory potential. GCM displayed cytostatic activity against HT-29 cells, causing accumulation of cells in G1 phase, blocking the cycle cell progression. Those glucans also showed ability to modulate the adhesion of HT-29 cells to Matrigel® and reduced the oxidative stress. The antiproliferative activity against HT-29 cells displayed by GCM (p <0.001) can be attributed to its cytostatic activity and induction of apoptosis by GCM