Oxidative stress and cellular immunity in patients with recurrent aphthous ulcers

Recurrent aphthous ulcer (RAU) is an inflammatory condition of the oral mucosa characterized by painful, well-circumscribed, single or multiple round or ovoid ulcerations. The exact etiologic factor(s) of these ulcerations are not yet understood. The objective of this study was to evaluate inflammatory processes and free radical metabolism of 25 patients with RAUs compared to 25 healthy controls. The levels of malondialdehyde (MDA) and glutathione (GSH) were determined by high-performance liquid chromatography. Tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), IL-10, and IL-12 were determined by ELISA. Nitric oxide (NO), myeloperoxidase (MPO), total antioxidant status (TAS), and total oxidant status (TOS) levels were measured spectroscopically in serum. The levels of MDA, GSH, TNF-α, IL-2, IL-12, MPO, and TOS, and oxidative stress index (OSI) were higher, and the levels of NO, IL-10, and TAS were lower in patients with RAU than in controls. Statistical analysis showed that GSH, TNF-α, IL-2, IL-10, and OSI differed significantly in patients with RAU compared to controls. These parameters have important roles in oxidant/antioxidant defense.

High prevalence of methicillin resistance and PVL genes amongStaphylococcus aureus isolates from the nares and skin lesions of pediatric patients with atopic dermatitis

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureusisolates from skin infections. Methicillin-resistant S. aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.

Influence of carbon source and the fermentation process on levan production by Zymomonas mobilis analyzed by the surface response method

The aim of this study is to assess sugar cane juice and sucrose as substrates, the batch and fed batch processes and their interaction in the levan production using a complete factorial design. Zymomonas mobilis was cultivated in different sugar cane juice and sucrose concentrations in two fermentation processes at 25 °C for 20 h. A complete factorial design (2³) was used to analyze the effects of the type and concentration of the substrate, as well as the batch and fed batch processes. A complete second factorial design (2²) was used to observe the importance of sugar cane juice. The results indicated that the batch process improved the levan production reaching 40.14 g/L. The addition of sugar cane juice was not statistically significant for levan formation, however sugar cane juice stimulated biomass, sorbitol and ethanol production. The best medium for levan production was 150 g/L sucrose in batch.

Experimental results and modeling of poultry carcass cooling by water immersion

Poultry carcasses have to be chilled to reduce the central breast temperatures from approximately 40 to 4 °C, which is crucial to ensure safe products. This work investigated the cooling of poultry carcasses by water immersion. Poultry carcasses were taken directly from an industrial processing plant and cooled in a pilot chiller, which was built to investigate the influence of the method and the water stirring intensity on the carcasses cooling. A simplified empiric mathematical model was used to represent the experimental results. These results indicated clearly that the understanding and quantification of heat transfer between the carcass and the cooling water is crucial to improve processes and equipment. The proposed mathematical model is a useful tool to represent the dynamics of carcasses cooling, and it can be used to compare different chiller operational conditions in industrial plants. Therefore, this study reports data and a simple mathematical tool to handle an industrial problem with little information available in the literature.

Peroxidase activity and sensory quality of ready to cook mixed vegetables for soup: combined effect of biopreservatives and refrigerated storage

Enzymatic senescence processes and browning of fresh cut vegetables negatively affect their sensory properties and nutritional value and finally result in the rejection of affected products by consumers. In order to prevent quality decay, the combined effects of natural antioxidants and storage temperature on peroxidase activity and sensory attributes (overall visual quality, browning and odor) of individual and mixed vegetables for soup (butternut squash, leek and celery) were evaluated. Fresh cut vegetables were treated with antioxidant solutions as tea tree essential oil (15 μl/mL), propolis extract (15 μl/mL) and gallic acid (2 mg/mL) and stored at optimal (5 °C) and abusive (15 °C) temperature for a maximum of 14 days. The application of natural preservatives, plus optimal storage conditions, exerted significant inhibitory effects in peroxidase activity of squash, celery and mixed vegetables throughout the storage. Furthermore, propolis treatment applied on mixed vegetables retarded browning appearance and preserved the visual quality for a longer period when compared to untreated product.

Lactose hydrolysis potential and thermal stability of commercial β-galactosidase in UHT and skimmed milk

Abstract The commercial enzyme (E.C. = 3.2.1.23) from Kluyveromyces lactis (liquid) and Aspergillus oryzae(lyophilized) was investigated for its hydrolysis potential in lactose substrate, UHT milk, and skimmed milk at different concentrations (0.7; 1.0 and 1.5%), pH values (5.0; 6.0; 6.5 and 7.0), and temperature (30; 35; 40 and 55 ºC). High hydrolysis rates were observed for the enzyme from K. lactis at pH 7.0 and 40 ºC, and from A. oryzae at pH 5.0 and 55 ºC. The enzyme from K. lactis showed significantly higher hydrolysis rates when compared to A. oryzae. The effect of temperature and β-galactosidase concentration on the lactose hydrolysis in UHT milk was higher than in skimmed milk, for all temperatures tested. With respect to the thermal stability, a decrease in hydrolysis rate was observed at pH 6.0 at 35 ºC for K. lactisenzyme, and at pH 6.0 at 55 ºC for the enzyme from A. oryzae. This study investigate the hydrolysis of β-galactosidase in UHT and skimmed milk. The knowledge about the characteristics of the β-galactosidase fromK. lactis and A. oryzae enables to use it most efficiently to control the enzyme concentration, temperature, and pH in many industrial processes and product formulations.