980 resultados para Formative Evaluation
Resumo:
Much information on flavonoid content of Brazilian foods has already been obtained; however, this information is spread in scientific publications and non-published data. The objectives of this work were to compile and evaluate the quality of national flavonoid data according to the United States Department of Agriculture`s Data Quality Evaluation System (USDA-DQES) with few modifications, for future dissemination in the TBCA-USP (Brazilian Food Composition Database). For the compilation, the most abundant compounds in the flavonoid subclasses were considered (flavonols, flavones, isoflavones, flavanones, flavan-3-ols, and anthocyanidins) and the analysis of the compounds by HPLC was adopted as criteria for data inclusion. The evaluation system considers five categories, and the maximum score assigned to each category is 20. For each data, a confidence code (CC) was attributed (A, B, C and D), indicating the quality and reliability of the information. Flavonoid data (773) present in 197 Brazilian foods were evaluated. The CC ""C"" (as average) was attributed to 99% of the data and ""B"" (above average) to 1%. The main categories assigned low average scores were: number of samples; sampling plan and analytical quality control (average scores 2, 5 and 4, respectively). The analytical method category received an average score of 9. The category assigned the highest score was the sample handling (20 average). These results show that researchers need to be conscious about the importance of the number and plan of evaluated samples and the complete description and documentation of all the processes of methodology execution and analytical quality control. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
Feijo, T.S., Cardozo, SX, Daleprane, J.B., Sabaa Srur, A.U.O. & Boaventura, G.T. [Evaluation of the influence of the proteinic quality of the genetically modified and organic soy beans in the growth of two generations of rats Wistar.] Avaliacao da influencia da qualidade proteica da soja geneticamente modificada e organica no crescimento de duas geracoes de ratos Wistar. Revista Brasileira de Medicina Veterinaria, 31(3):139-144, 2009. Programa de Pos-Graduacao em Patologia, Hospital Universitario Antonio Pedro. Centro de Ciencias Medicas, Universidade Federal Fluminense. Rua Marques do Parana, 303, Niteroi, RJ 24030-210, Brasil. E-mail: sergian@ufnj.br Sixty four Wistar rats, male of two consecutive generations determined as F(0) and F(1) were used to study the cumulative effect of two variety soy beans, cultivated with organic seasoning and genetically modified, The animals of each generation were divided into three groups of eight rats each fed on diets consisted of organic soy, soy genetically modified and casein respectively. All the animals received water and the diet ad libitum for period of 28 days. Where the diet consumption and the animals weight were evaluated. After statistic analysis of the results no expressive differences were observed on diet consumption, weight variation, protein efficient ratio and food efficiency ratio on same group of animals in the different generations. On the other hand, significant difference was found on final proteinic retention on animal descendants of the same groups; however of different generations. With this, the supplementation of organic soy with L-cistin provided better avail of this protein in relation to the protein of the soy genetically modified. However, this supplementation did not reveal efficiency in keeping the proteinic employment from one generation to another one, since soy varieties presented better performance on F(0) generation when compared with F(1).
Resumo:
Evaluation of commercially available test kits for Chagas disease for use in blood bank screening is difficult due to a lack of large and well-characterized specimen panels. This study presents a collaborative effort of Latin American blood centers and the World Health Organization (WHO) to establish such a panel. A total of 437 specimens, from 10 countries were collected and sent to the WHO Collaborating Center in Sao Paulo and used to evaluate 19 screening assays during 2001 through 2005. Specimens were assigned a positive or negative status based on concordant results in at least three of the four confirmatory assays (indirect immunofluorescence, Western blot, radioimmunoprecipitation assay, and recombinant immunoblot). Of the 437 specimens, 168 (39%) were characterized as positive, 262 (61%) were characterized as negative, and 7 (2%) were judged inconclusive and excluded from the analysis. Sensitivity and specificity varied considerably: 88 to 100 and 60 to 100 percent, respectively. Overall, enzyme immunoassays (EIAs) performed better than the other screening assays. Four EIAs had both parameters higher than 99 percent. Of the four confirmatory assays, only the RIPA gave a 100 percent agreement with the final serologic status of the specimens. The sensitivities and specificities of at least four of the commercially available EIAs for Chagas disease are probably high enough to justify their use for single-assay screening of blood donations. Our data suggest that the majority of commercially available indirect hemagglutination assays should not be used for blood donor screening and that the RIPA could be considered a gold standard for evaluating the performance of other assays.
Resumo:
In this study, in vitro anti-T. cruzi activity assays of nifuroxazide (NX) analogues, such as 5-nitro-2-furfuryliden and 5-nitro-2-theniliden derivatives, were performed. A molecular modeling approach was also carried out to relate the lipophilicity potential ( LP) property and biological activity data. The majority of the NX derivatives showed increased anti-T. cruzi activity in comparison to the reference drug, benznidazole (BZN). Additionally, the 5-nitro-2-furfuryliden derivatives presented better pharmacological profile than the 5-nitro-2-theniliden analogues. The LP maps and corresponding ClogP values indicate that there is an optimum lipophilicity value, which must be observed in the design of new potential anti-T. cruzi agents. (c) 2009 Elsevier Ltd. All rights reserved.
Resumo:
The study compared the growth capability of probiotic (Lactobacillus acidophilus La05, Lactobacillus casei Lc01 and Bifidobacterium animalis Bb12) and non-probiotic (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus) cultures on twenty-one culture media grouped according to selectivity: nonselective agars, selective agars without antibiotics and MRS agars containing different combinations of lithium chloride, cystein, bile salts and antibiotics. Four of these media were selected for quantitative enumeration of L acidophilus La05, L casei Lc01, and B. animalis Bb12. The best culture media and incubation conditions for enumeration of the probiotic cultures were: B. animalis: MRS agar with dicloxacillin, 37 degrees C or 42 degrees C, anaerobiosis; L acidophilus: MRS agar with bile salts, 37 degrees C or 42 degrees C, aerobiosis; L casei: MRS agar with lithium chloride and sodium propionate, 37 degrees C or 42 degrees C, aerobiosis or anaerobiosis. Plating on MRS with glucose replaced by maltose, 37 degrees C or 42 degrees C, anaerobiosis, will distinguish probiotic from non-probiotic cultures. For enumeration of each probiotic in a mixed culture, the following media and incubation conditions were recommended: B. animalis: 4ABC-MRS, 42 degrees C, anaerobiosis, L acidophilus: LC medium, 42 degrees C, aerobiosis or anaerobiosis and L casei: LP-MRS, 42 degrees C, aerobiosis or anaerobiosis. In all experiments, differences in counts using pour plating or surface plating were not significant (P <= 0.05). (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.
Resumo:
Sensory acceptance of formulations of probiotic Minas fresh cheese was investigated. Cheeses were prepared and supplemented with Lactobacillus acidophilus (T1 - probiotic), Lactobacillus acidophilus + Streptococcus thermophilus (T2 - probiotic + starter) or produced with no addition of cultures (T3 - control). Sensory acceptance tests were performed after 7 and 14 days of storage at 5 degrees C, using a 9-point hedonic scale (1 = dislike extremely; 9 = like extremely). After 7 days, no significant difference was detected among cheeses T1, T2 and T3 (P > 0.05). After 14 days, cheeses T1 and T2 presented higher acceptance and differed significantly from cheeses T3. Cheeses T3 presented significant difference between 7 and 14 days of storage (P < 0.05), whereas probiotic cheeses T1 and T2 were stable in the same period (P > 0.05). The addition of L. acidophilus, either solely or in co-culture with a thermophilic starter culture, resulted in good acceptance of Minas fresh cheese, improving sensory performance of the product during storage.
Resumo:
As a consequence of the large distribution and use of medicinal plants, the industries are producing products based on plant species in various pharmaceutical forms, which have been commercialized in pharmacies and natural products homes. However, there is no guarantee for the vast majority of these products, as to their effctiveness, safety, and quality, which may cause risks to the health of consumers. There it is important the establishment of standardized protocols of quality control for phytotherapeutic products. Tinctures of barbatimao are available in the Brazilian market proceeding from diverse manufacturers. With the purpose to evaluate the difference between the quality of tinctures of barbatimao proceeding from four manufactures, a comparative study of ph ysico-chenfical andphylocheinical characteristics was carried out. For physico-chemical analysis, the pH, density, dry residue and tannins content were evaluated. The phytochemical analysis was made using thin layer chromatography. The differences observed in physico-chemical and phytochemical characteristics had evidenced the lack of standardization in the production of these tinctures.
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Ent-kaur-16(17)-en-19-oic acid (kaurenoic acid, KA) is a tetracyclic diterpene prototype for natural anticaries agents. Six KA derivatives were prepared and their antimicrobial activity against the main microorganisms involved in the caries process evaluated. The sodium salt of KA (KA-Na) was the most active, displaying very promising MIC values for most pathogens. Time-kill assays against the primary causative agent of caries (Streptococcus mutans) indicated that KA and KA-Na only inhibited growth in the first 12 h, suggesting a bacteriostatic effect. After this period (12-24 h), their bactericidal effect was clearly noted. KA and KA-Na showed no synergy when combined with the gold standard anticariogenic (chlorhexidine dihydrochloride, CHD) in the checkerboard assays against S. mutans.
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Aim of the study: In a previous study, our group described the gastric protective effect of the hydroalcoholic extract of Brazilian green propolis. The main compounds found in Brazilian green propolis include phenolic acids, such as: caffeic, ferulic, p-coumaric and cinnamic acids. This study was therefore carried out to evaluate the antiulcerogenic property of the main phenolic acids found in Brazilian Green Propolis. Material and methods: The anti-ulcer assays were performed using the following protocols: nonsteroidal-antinflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, and stress-induced ulcer. The effects of the phenolic acids on gastric content volume, pH and total acidity, using the pylorus ligated model, were also evaluated. Results: It was observed that treatment using doses of 50 and 250 mg/kg of caffeic, ferulic, p-coumaric and cinnamic acids and positive controls (omeprazol or cimetidine) significantly diminished the lesion index, the total area of the lesion and the percentage of lesion in comparison with the negative control groups. In addition, the percentage of ulcer inhibition was significantly higher in the groups treated with the different phenolic acids, cimetidine or omeprazol, in all the protocols used, compared with the negative control groups. In the model to determine gastric secretion, using ligated pylorus, treatment with phenolic acids and cimetidine reduced the volume of gastricjuice and total acidity and significantly increased the gastric pH (p < 0.05), compared with the control group, with the exception of the group treated with 50 mg/kg of p-coumaric acid, in which no significant difference was observed, compared with the control. In relation to the acute toxicity, none sign of toxicity was observed when phenolic acids, used in this study, were administered for rats in dose of 2000 mg/kg. Conclusions: In conclusion, the results of this study show that caffeic, ferulic, p-coumaric and cinnamic acids display antiulcer activity. (c) 2008 Elsevier Ireland Ltd. All rights reserved.
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In this work, we have used molecular dynamics, density functional theory, virtual screening, ADMET predictions, and molecular interaction field studies to design and propose eight novel potential inhibitors of CDK2. The eight molecules proposed showed interesting structural characteristics that are required for inhibiting the CDK2 activity and show potential as drug candidates for the treatment of cancer. The parameters related to the Rule of Five were calculated, and only one of the molecules violated more than one parameter. One of the proposals and one of the drug-like compounds selected by virtual screening indicated to be promising candidates for CDK2-based cancer therapy.
Resumo:
Hydrodynamic studies were conducted in a semi-cylindrical spouted bed column of diameter 150 mm, height 1000 mm, conical base included angle of 60 degrees and inlet orifice diameter 25 mm. Pressure transducers at several axial positions were used to obtain pressure fluctuation time series with 1.2 and 2.4 mm glass beads at U/U-ms from 0.3 to 1.6, and static bed depths from 150 to 600 mm. The conditions covered several flow regimes (fixed bed, incipient spouting, stable spouting, pulsating spouting, slugging, bubble spouting and fluidization). Images of the system dynamics were also acquired through the transparent walls with a digital camera. The data were analyzed via statistical, mutual information theory, spectral and Hurst`s Rescaled Range methods to assess the potential of these methods to characterize the spouting quality. The results indicate that these methods have potential for monitoring spouted bed operation.
Resumo:
Due to differences in the functional quality of natural extracts, we have also faced differences in their effectiveness. So, it was intended to assess the antioxidant activity of natural extracts in order to attain their functional quality. It was observed that all the extracts (brown and green propolis, Ginkgo biloba and Isoflavin Beta (R)) and the standard used (quercetin) showed antioxidant activity in a dose-dependent manner with IC50 values ranging from 0.21 to 155.28 mu g mL(-1) (inhibition of lipid peroxidation and scavenging of the DPPH center dot assays). We observed a high correlation (r(2)= 0.9913) among the antioxidant methods; on the other hand, the antioxidant activity was not related to the polyphenol and flavonoid content. As the DPPH center dot assay is a fast method, presents low costs and even has a high correlation with other antioxidant methods, it could be applied as an additional parameter in the quality control of natural extracts.
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Stable multiple emulsions containing andiroba oil and sunscreen have been formulated. These were prepared using the two-step procedure. The formulations were characterized and their stability over the time was evaluated by centrifugation, macroscopic, and microscopic analyses, and rheological measurements. The photoprotective efficacy of the O/W and O1/W/O2 containing or not andiroba oil was evaluated by in vivo sun protection factor determination according to the FDA method. The formulations exhibited good stability during 30 days after preparation at different temperatures. These presented pseudoplastic flow behaviour and thixotropy. The increase of in vivo SPF value was not observed when andiroba oil was incorporated into emulsions containing ethylhexyl methoxycinnamate. These multiple emulsions can be utilized as an interesting topical vehicle.
Resumo:
The effects of some composition variables on the development of multiple emulsions by one-step method were evaluated and their morphology characterized. The formulations that remained stable during the period of the test were submitted to centrifugation and thermal stress tests. The stability and the morphology of multiple droplets were affected not only by the type and concentration of the surfactants employed, but also by the water/oil ratios used. The results suggest that the formation of multiple droplets could involve a combination of transitional and catastrophic phase inversions. The results provide improved knowledge about the one-step emulsification method, a simplified process to prepare multiple emulsions when compared to the two-steps method.
Resumo:
Considering that antioxidant flavonols have been reported to be beneficial to human health, but that their low water solubility and bioavailability limit their administration through systemic route, the development of suitable flavonol-carriers is of great importance for clinical therapeutics. The aim of this study was to prepare liposomes containing flavonols or not and evaluate their antioxidant activity. Vesicles were obtained by ethanol injection method and characterized in terms of entrapment efficiency, size and zeta potential. Inhibitory activity of liposomal flavonols on reactive oxygen species generation was assessed in vitro using luminol--H(2)O(2)--horseradish peroxidase technique. Antioxidant activity of liposomal flavonols is dependent on concentration and chemical structure of active compound. Quercetin and myricetin are the most active flavonols (IC(50) == 0.6--0.9 mu A mu mol/L), followed by kaempferol (IC(50) == 3.0--4.5 mu A mu mol/L) and galangin (IC(50) == 4.0--7.0 mu A mu mol/L). Our results suggest that antioxidant-loaded liposomes may be promising tools for therapy of diseases where oxidative stress is involved.