A physiological manoeuvre to improve the positivity of the gastro-oesophageal reflux scintigraphic test

One of the best examinations used routinely to detect gastro-oesophageal reflux (GOR) is scintigraphy and attempts are continuously being made to improve the performance of the test. We have tested a new manoeuvre to improve the results. Three hundred and twenty eight patients (190 males and 138 females, aged 1 month to 84 years, average 4.47 years) were studied after a 12 h fast period with 100 MBq of Tc-99(m)-Phytate, 50 ml volume, directly delivered into the stomach in a mixture of orange juice. All patients were strongly suspected of having GOR. Conventional acquisition was done for 20 min, at a rate of one frame every 20 s. in the middle of the examination, small children were put in the upright position and held there for a few seconds or released in a way that allowed movement; adults were asked to stand up and walk a few metres. The test was then continued for the remaining 10 min. The global index of positivity was 64.6% (76 positive cases in the first half of the examination and 134 positive cases only after the manoeuvre). The mean of GOR episodes observed in the positive cases without the manoeuvre was 0.5 per patient, significantly different from the mean of 1.59 noted after the manoeuvre (P<0.01). In 28 cases the manoeuvre increased either the intensity or the frequency of reflux previously detected without it. We believe that this manoeuvre should be performed in all scintigraphic tests aiming to detect GOR. In the present series, the manoeuvre increased the frequency of GOR episodes. ((C) 2001 Lippincott Williams & Wilkins)].

Determinação da razão isotópica delta13C em bebidas comerciais a base de laranja

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production and characterization of polygalacturonase from thermophilic Thermoascus aurantiacus on submerged fermentation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Friction losses in valves and fittings for liquid food products

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilização do resíduo líquido de indústria de processamento de suco de laranja como meio de cultura de Penicillium citrinum: depuração biológica do resíduo e produção de enzima

Penicillium citrinum grown in orange juice processing wastes medium under continuous agitation was studied in order to establish optimal conditions (incubation period, incubation temperature, initial pH and nitrogen addition) for biomass and ribonuclease production, as well as, biological depuration of the wastes. Nitrogen addition to wastes medium increased the biomass and ribonuclease production and provides COD reduction. The soy meal shows to be the best nitrogen source. The conditions for a more favorable enzyme and biomass production and COD reduction were initial pH 6.0 and temperature of 27°C. The maximum value obtained for these parameters on optimal conditions of cultivation was 11 U/mL of enzyme, 4 mg/mL of biomass (dry matter) and 55% of COD reduction, in 96 hours of incubation.

Simple and fast spectrophotometric determination of H2O2 in photo-Fenton reactions using metavanadate

This work proposes a spectrophotometric method for the determination of hydrogen peroxide during photodegradation reactions. The method is based on the reaction of H2O2 with amonium metavanadate in acidic medium, which results in the formation of a red-orange color peroxovanadium cation, with maximum absorbance at 450 nm. The method was optimized using the multivariate analysis providing the minimum concentration of vanadate (6.2 mmol L-1) for the maximum absorbance signal. Under these conditions, the detection limit is 143 mu mol L-1. The reaction product showed to be very stable for samples of peroxide concentrations up to 3 mmol L-1 at room temperature during 180 h. For higher concentrations however, samples must be kept refrigerated (4 degrees C) or diluted. The method showed no interference of Cl- (0.2-1.3 mmol L-1), NO3- (0.3-1.0 mmol L-1), Fe3+, (0.2-1.2 mmol L-1) and 2,4-dichlorophenol (DCP) (0.2-1.0 mmol L-1). When compared to iodometric titration, the vanadate method showed a good agreament. The method was applied for the evaluation of peroxide consumption during photo-Fenton degradation of 2,4-dichlorophenol using blacklight irradiation. (c) 2004 Elsevier B.V. All rights reserved.

Reagentless biosensor for isocitrate using one step modified Pt-Ir microelectrode

The Pt-Ir microelectrode modified through one step, electropolymerization is proposed for the isocitrate amperometric biosensor construction. The enzyme (isocitrate dehydrogenase-ICDH), coenzyme (NADP(+)) and mediator (Meldola's Blue) were immobilized onto the microelectrode surface in one step from a PIPES buffer solution containing pyrrole. The optimized experimental conditions were 25 cycles of cyclic voltammetric in a solution containing 3.58 10(-5) mol l(-1) of mediator, 3.51 10(-4) mol l(-1) of coenzyme and 2.68 U ml(-1) of enzyme. In contrast to the biosensor for isocitrate reported in literature, just one enzyme was immobilized and no coenzyme addition in the solution of analysis was necessary. Catalytic currents were proportional to the isocitrate concentration between 7.7 10(-6) and 1.04 10(-4) mol l(-1), showing good repeatability. The detection limit of the proposed biosensor was 3.50 10(-6) mol l(-1), the response time was lower than 20 s, the lifetime was about 30 determinations and no significant interference of sugars and citric acid was verified. Orange juice samples were analysed by both methodology biosensor and spectrophotometric commercial kit, and the obtained results presented a good correlation. The data demonstrated that the developed biosensor is suitable for isocitrate determination in orange juice without matrix interferences. (C) 2001 Elsevier B.V. B.V. All rights reserved.

In vitro evaluation of the effect of dietary acids and toothbrushing on human root dentin permeability

OBJECTIVES: The purpose of this in vitro study was to quantify the alterations in human root dentin permeability after exposure to dietary acids and to evaluate the effect of toothbrushing after acid application. METHOD AND MATERIALS: Extracted human third molars had their crowns sectioned above the CEJ, pulp tissue removed, and cervical root dentin exposed using a high-speed bur (approximately 1 mm in depth of substance loss). From each root fragment, one specimen was prepared. A total of 25 specimens were used and distributed randomly into five groups. The specimens were attached to a hydraulic pressure apparatus to evaluate the alterations of root dentin permeability after exposure to different acids. Dentin permeability was measured after the following sequential steps: (1) treatment with EDTA for 3 minutes to obtain the maximum permeability; (2) root planing to create a smear layer; (3) exposure to different acidic substances for 5 minutes (vinegar, cola drink, lemon juice, white wine, and orange juice); and (4) brushing for 3 minutes. RESULTS: All acidic substances increased dentin permeability after root planing. Lemon juice produced higher values for permeability when compared to the other substances (P = .009); moreover, orange juice showed similar results (P < .02) except when compared to vinegar (P = .12). Brushing right after acid exposure significantly reduced dentin permeability except in the vinegar group (P = .07). CONCLUSION: Under the experimental conditions, dietary acids increased root dentin permeability, and immediate brushing reduced permeability levels.

Avaliação do estresse oxidativo no sangue de consumidores habituais de suco de laranja

Two biomarkers of oxidative stress were evaluated in healthy volunteers treated with daily doses of orange juice that is well known source of vitamin C and citric flavanones, which have been associated with antioxidant, anti-inflammatory and hypolipidemic effects. The antioxidant capacity in the blood serum was evaluated by studying the scavenging of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical, and also lipid peroxidation was evaluated by the thiobarbituric acid reacting substances (TBARS) assay. The results have shown that the regular consumption of orange juice increased 150% and 200% the serum antioxidant capacity for women and men respectively, but it was no significant change in the serum lipid peroxidation. In conclusion, the increase of flavonones and vitamin C in the body due to the regular intake of orange juice expressively improved the antioxidant capacity, but without significant effect on the lipid peroxidation.

Impacto da tecnologia de alta pressão hidrostática sobre a qualidade do suco de laranja

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interpretação do consumidor, avaliação da intenção de compra e das características físico-químicas do néctar e do suco de laranja pronto para beber

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Perfil sensorial e aceitabilidade de aguardente de Liquor de laranja

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da viabilidade técnico-econômica da produção industrial da aguardente do licor de laranja

Pós-graduação em Alimentos e Nutrição - FCFAR

Caracterização dos óleos extraídos de sementes de laranjas (Citrus sinensis) como aproveitamento de resíduos agroindustriais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação de atividade antioxidante e da resposta glicêmica e insulínica do suco de laranja fresco em comparação ao suco de laranja pasteurizado no soro sanguíneo de indivíduos saudáveis

Pós-graduação em Alimentos e Nutrição - FCFAR