115 resultados para free-choice profile


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The main objectives of the present study were (a) to study the effects of the different combinations of Lactobacillus delbrueckii subsp. bulgaricus (Lb), Lactobacillus acidophilus (La), Lactobacillus rhamnosus (Lr), and Bifidobacterium animalis subsp. lactis (BI) in co-culture with Streptococcus thermophilus (St) on the rate of acid development in milk and milk-whey mixture, and (b) the effect of the level of the total solids of the different bases on the acidification profile and viability of potential health-promoting microorganisms. The co-culture of St-Lr showed the lowest values V(max) in all bases; while the co-culture St-Bl had high t(Vmax) in milk and whey bases (12 and 10 g/100 g, respectively). Co-cultures St-La and St-Lb reached V(max) at pH 5.5, while St-Lr and St-Bl at pH 5.91. Fermentation time to reach pH 4.5 was longer when St-Lr co-culture was used, while St-Lb had the lowest value. All the products had slight development of acid during the storage period, and lowest values were observed when the St-Bl co-culture was employed. Lb, BI and St cultures had high counts at pH 4.5 in the three bases. The total solids affected the viability of Lb and La. The technological interest of these combinations is discussed in this article. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. AM rights reserved.

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The effects of acai pulp addition and different probiotic bacteria on the fatty acid profile of stirred yoghurt were examined. Skim milk was divided into two groups: one containing acai pulp and another without the fruit. Batches were inoculated with yoghurt starter culture and divided into five groups according to probiotic addition. Counts of viable microorganisms were measured at days 1, 14 and 28 of cold storage. Fatty acid profile was determined by gas chromatography at day 1. Acai pulp favoured an increase in Lactobacillus acidophilus L10, Bifidobacterium animalis ssp. lactis Bl04 and Bifidobacterium longum Bl05 counts at the end of 4 weeks of cold storage. This study demonstrated that acai pulp addition increased monounsaturated and polyunsaturated fatty acid contents in probiotic yoghurt and enhanced the production of cc-linolenic and conjugated linoleic acids during fermentation of skim milk prepared with B. animalis ssp. lactis Bl04 and B94 strains. (C) 2010 Elsevier Ltd. All rights reserved.

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Phenolic compounds are found in seaweed species together with other Substances presenting antioxidant activity. The objective of this work was to evaluate the antioxidant activity of the free phenolic acids (FPA) fraction from the seaweed Halimeda monile, and its activity to protect the expression of hepatic enzymes in rats, under experimental CCI(4) injury. The antioxidant activity was measured by the DPPH method. The FPA fraction (80 mg/kg, p.o.) was administered during 20 consecutive days to rats. The peroxidation was performed by thiobarbituric acid reactive substances (TBARS). The SOD and CAT enzymatic expressions were measured by RT/PCR. The histology technique was used to evaluate liver injuries. The expression of both, CAT and SOD genes, was more preserved by FPA. Only partial injury could be observed by histology in the liver of rats receiving FPA as compared with the control group; and CCI(4) administration induced 60% more peroxidation as compared with the rats receiving FPA. These data suggest that FPA could modulate the antioxidant enzymes and oxidative status in the liver through protection against adverse effects induced by chemical agents.

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The objective of the present study was to evaluate the occurrence of Salmonella spp. in 15 samples of pork meat cuts (T-bone, shank, sausage and ribs) commercialized in open markets of Pelotas (RS, Brazil) and verify the prevalent serovars, and test the isolates profile of sensitivity to several antibiotics of importance in medicine (nalidixic acid, ampicillin, aztreonam, kanamycin, carbenicillin, cephalothin, cefoxitin, ceftriaxone, ciprofloxacin, chloramphenicol, gentamicin, sulfonamide, tetracycline and trimetoprina). Twelve samples (80%) were contaminated by Salmonella enterica, serovars Infantis, Derby, Panama and Typhimurium. All isolates were susceptible to trimetoprin, aztreonam, ciprofloxacin, ceftriaxone and cefoxitin. For the other antibiotics, the pattern of sensitivity varied as serovar. In addition, 39.1% of isolates showed up to be multiresistant.

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The reactive oxygen species (ROS) produced by neutrophils are involved in the pathogenesis of several diseases, for which the intake of antioxidants could benefit patients either as a prophylactic or therapeutic treatment. Propolis is among the known antioxidants, and its chemical composition may vary under the influence of seasonality, which may interfere in its biological properties. This work evaluates the role of seasonality on the production of some important compounds of propolis samples produced monthly from November 2001 through October 2002 as well as the effect of these samples on the oxidative metabolism of stimulated neutrophils, by using both luminol and lucigenin to produce chemiluminescence (CLlum and CLluc, respectively). The cytotoxicity of the most active extracts to neutrophils was also investigated. The inhibitory effect of the propolis samples varied significantly during the studied period for both assays (3.4 +/- 1.1 to 16.0 +/- 1.1 mu g/mL for CLlum and 6.2 +/- 2.0 to 30.0 +/- 5.0 mu g/mL for CLluc), which was also observed in the quantitative profile of the main analyzed compounds (aromadendrin-4`-methyl ether, artepillin C, and baccharin). This effect started to become more prominent during the fall and, among all the studied extracts, the one obtained in May displayed the highest inhibitory effect on CL production (3.4 +/- 1.1 mu g/mL for alum and 6.2 +/- 2.0 mu g/mL for CLluc). The HPLC qualitative profiles of the extracts of propolis samples were quite similar, but there was a huge variation in terms of quantitative profile. It seems that aromadendrin-4`-methyl ether and baccharin play an essential role in the antioxidant activity, while artepillin C is not very important for this effect. The extracts presenting the highest antioxidant activity were produced in May, June, and August, and they did not display cytotoxicity at 25 mu g/mL; quercetin, used as control, was not toxic to neutrophils at 8.5 mu g/mL (C) 2010 Elsevier B.V. All rights reserved.

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P>With the evidence showing the protection variability of bacille Calmette-Guerin, new potential vaccines for tuberculosis have been tested around the world. One of the general concerns in tuberculosis vaccine development is the possibility of priming the host immune system with prior exposure to environmental mycobacteria antigens, which can change the efficacy of subsequent vaccination. As there is a great homology between the species from Mycobacterium genera, the previous contact of experimental animals with environmental mycobacteria could sensitize the mice and, in this way, could influence subsequent vaccine research. The aim of our study was to investigate critical points in an animal facility to search for environmental mycobacteria that eventually could be in direct or indirect contact with the experimental animals. Samples were collected from surfaces of walls, floor, animal cages and shelves and analysed using the Ogawa-Kudoh decontamination method. Samples of drinking water, food and sawdust were collected for analysis by the NALC/NaOH decontamination method. Also, the samples were cultivated directly in broth medium, without any method for decontamination. After decontamination methods, we observed bacterial colony growth in 4.31% of the total of samples analysed. These samples were stained with Ziehl-Neelsen and we did not detect any acid-fast bacilli, suggesting that the animal facility analysed is free from contamination by environmental mycobacteria and is not a source of mycobacterial antigens. Furthermore, our study showed a new paradigm in tuberculosis vaccine development: concern about the animal facility environment in terms of immune system priming of experimental animals by nascent bacterial contaminants.

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Crotalus durissus rattlesnakes are responsible for the most lethal cases of snakebites in Brazil. Crotalus durissus collilineatus subspecies is related to a great number of accidents in Southeast and Central West regions, but few studies on its venom composition have been carried out to date. In an attempt to describe the transcriptional profile of the C. durissus collilineatus venom gland, we generated a cDNA library and the sequences obtained could be identified by similarity searches on existing databases. Out of 673 expressed sequence tags (ESTs) 489 produced readable sequences comprising 201 singletons and 47 clusters of two or more ESTs. One hundred and fifty reads (60.5%) produced significant hits to known sequences. The results showed a predominance of toxin-coding ESTs instead of transcripts coding for proteins involved in all cellular functions. The most frequent toxin was crotoxin, comprising 88% of toxin-coding sequences. Crotoxin B, a basic phospholipase A(2) (PLA(2)) subunit of crotoxin, was represented in more variable forms comparing to the non-enzymatic subunit (crotoxin A), and most sequences coding this molecule were identified as CB1 isoform from Crotalus durissus terrificus venom. Four percent of toxin-related sequences in this study were identified as growth factors, comprising five sequences for vascular endothelial growth factor (VEGF) and one for nerve growth factor (NGF) that showed 100% of identity with C. durissus terrificus NGF. We also identified two clusters for metalloprotease from PII class comprising 3% of the toxins, and two for serine proteases, including gyroxin (2.5%). The remaining 2.5% of toxin-coding ESTs represent singletons identified as homologue sequences to cardiotoxin, convulxin, angiotensin-converting enzyme inhibitor and C-type natriuretic peptide, Ohanin, crotamin and PLA(2) inhibitor. These results allowed the identification of the most common classes of toxins in C. durissus collilineatus snake venom, also showing some unknown classes for this subspecies and even for C. durissus species, such as cardiotoxins and VEGF. (C) 2009 Published by Elsevier Masson SAS.

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Matrix metalloproteinases (MMPs) are promising diagnostic tools, and blood sampling/handling alters MMP concentrations between plasma and serum and between serum with and without clot activators. To explain the higher MMP-9 expression in serum collected with clot accelerators relative to serum with no additives and to plasma, we analyzed the effects of increasing amounts of silica and silicates (components of clot activators) in,citrate plasma, serum, and huffy coats collected in both plastic and glass tubes from 50 healthy donors, and we analyzed the effects of silica and silicate on cultured leukemia cells. The levels of MMP-2 did not show significant changes between glass and plastic tubes, between serum and plasma, between serum with and without clot accelerators, or between silica and silicate treatments. No modification of MMP-9 expression was obtained by the addition of silica or silicate to previously separated plasma and serum. Increasing the amounts of nonsoluble silica and soluble silicate added to citrate and empty tubes prior to blood collection resulted in increasing levels of MMP-9 relative to citrate plasma and serum. Silica and silicate added to buffy coats and leukemia cells significantly induced MMP-9 release/secretion, demonstrating that both silica and silicate induce the release of pro- and complexed MMP-9 forms. We recommend limiting the misuse of serum and avoiding the interfering effects of clot activators. (c) 2007 Elsevier Inc. All rights reserved.

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This work evaluated the Modulation of reactive oxygen species (ROS) produced by the cisplatin-human DNA interaction in a cell-free experimental model by the carotenoids bixin and lycopene extracted from, natural dietary Sources and purified through luminol- and Cypridina luciferin methoxy-analogue (MCLA)- enhanced chemiluminescence assays. The results showed that the ROS generation by DNA-cisplatin interaction was inhibited by both lycopene and bixin in a concentration-dependent manner. At a concentration of 100 mu M, lycopene and bixin inhibited Superoxide anion (O center dot(2)) generation at 90% and 82%, respectively, and the total ROS generation at 44% and 42%, respectively. The formation of significant amounts of isomers or degradation products of both carotenoids was not observed after ROS scavenging, as evaluated by high-performance liquid chromatography. Taken together, these results Suggest that carotenoids can be helpful to Modulate the oxidative stress found in cancer therapy with cisplatin. (c) 2008 Elsevier Ltd. All rights reserved.

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There exists a significant group of sources of a census nature for the study of slavery in the 1870s. These sources derive mainly from the registration of slaves that was established by the Law of the Free Womb of 1871. In this article, we discuss the different ways of presenting registration information. We analyze a sample of the registered slave population, including 69 towns from different parts of the country that total a little over 112,000 slaves and 25, 000 slave holders. In addition to characterizing the demographic profile of the slaves that make up the sample, we verify the ownership of slaves.