931 resultados para LACTIC-ACIDOSIS


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Objective To evaluate the changes in tissue perfusion parameters in dogs with severe sepsis/septic shock in response to goal-directed hemodynamic optimization in the ICU and their relation to outcome. Design Prospective observational study. Setting ICU of a veterinary university medical center. Animals Thirty dogs with severe sepsis or septic shock caused by pyometra who underwent surgery and were admitted to the ICU. Measurements and Main Results Severe sepsis was defined as the presence of sepsis and sepsis-induced dysfunction of one or more organs. Septic shock was defined as the presence of severe sepsis plus hypotension not reversed with fluid resuscitation. After the presumptive diagnosis of sepsis secondary to pyometra, blood samples were collected and clinical findings were recorded. Volume resuscitation with 0.9% saline solution and antimicrobial therapy were initiated. Following abdominal ultrasonography and confirmation of increased uterine volume, dogs underwent corrective surgery. After surgery, the animals were admitted to the ICU, where resuscitation was guided by the clinical parameters, central venous oxygen saturation (ScvO2), lactate, and base deficit. Between survivors and nonsurvivors it was observed that the ScvO2, lactate, and base deficit on ICU admission were each related independently to death (P = 0.001, P = 0.030, and P < 0.001, respectively). ScvO2 and base deficit were found to be the best discriminators between survivors and nonsurvivors as assessed via receiver operator characteristic curve analysis. Conclusion Our study suggests that ScvO2 and base deficit are useful in predicting the prognosis of dogs with severe sepsis and septic shock; animals with a higher ScvO2 and lower base deficit at admission to the ICU have a lower probability of death.

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Lactobacillus sakei 1 is a food isolate that produces a heat-stable antimicrobial peptide (sakacin 1, a class ha bacteriocin) inhibitory to the opportunistic pathogen Listeria monocytogenes. Bacterial isolates with antimicrobial activity may be useful for food biopreservation and also for developing probiotics. To evaluate the probiotic potential of L. sakei I, it was tested for (i) in vitro gastric resistance (with synthetic gastric juice adjusted to pH 2.0, 2.5, or 3.0); (ii) survival and bacteriocin production in the presence of bile salts and commercial prebiotics (inulin and oligofructose); (iii) adhesion to Caco-2 cells; and (iv) effect on the adhesion of L. monocytogenes to Caco-2 cells and invasion of these cells by the organism. The results showed that L. sakei I survival in gastric environment varied according to pH, with the maximum survival achieved at pH 3.0, despite a 4-log reduction of the population after 3 h. Regarding the bile salt tolerance and influence of prebiotics, it was observed that L. sakei 1 survival rates were similar (P > 0.05) for all de Man Rogosa Shame (MRS) broth formulations when tests were done after 4 h of incubation. However, after incubation for 24 h, the survival of L. sakei 1 in MRS broth was reduced by 1.8 log (P < 0.001), when glucose was replaced by either inulin or oligofructose (without Oxgall). L. sakei 1 was unable to deconjugate bile salts, and there was a significant decrease (1.4 log) of the L. sakei 1 population in regular MRS broth plus Oxgall (P < 0.05). In spite of this, tolerance levels of L. sakei 1 to bile salts were similar in regular MRS broth and in MRS broth with oligofructose. Lower bacteriocin production was observed in MRS broth when inulin (3,200 AU/ml) or oligofructose (2,400 AU/ml) was used instead of glucose (6,400 AU/ml). L. sakei I adhered to Caco-2 cells, and its cell-free pH-neutralized supernatant containing sakacin I led to a significant reduction of in vitro listerial invasion of human intestinal Caco-2 cells.

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Lactic acid bacteria are used in food production to provide desirable organoleptic characteristics, and can also act as biopreservatives, controlling the growth of undesirable microorganisms. In this study, we examined the antimicrobial action of Lactobacillus sakei 2a and its concentrated acid extract against food-borne Salmonella spp. The extract was obtained by acid extraction from culture broth of L. sakei 2a and was designated extract 2a. We determined that extract 2a had significant activity (approximately 500 AU ml(-1)). We used different antimicrobial substances alone or in combination with extract 2a to evaluate the inhibitory activity of the various treatments on a pool of five Salmonella strains. The pathogen Listeria monocytogenes Scott A Cm-r Em(r) was used as an indicator strain of inhibitory activity. In summary, all antimicrobials substances that were tested showed an inhibitory effect against the growth of Salmonella, andthis action was enhanced in the presence of extract 2a. Moreover, among the treatments applied, the combination of extract 2a and 0.1% lactic acid exhibited the most potent inhibitory effect towards the pool of Salmonella strains. Our findings indicate that L. sakei 2a and extract 2a, especially in combination with other antimicrobials, present potential technological application in the control of salmonellae in foods.

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A dried tomato-flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc-37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10(7) CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product.

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This work assessed the bioremediation of herbicide Velpar K (R), in vitro in aqueous solution, used against weeds in sugar cane in Sao Paulo state. The herbicide contained Hexazinone and Diuron. It was used the microbial inoculant denominated Effective Microorganisms (EM-4), pool of microorganisms from soil that contained lactic and photosynthetic bacteria, fungi, yeasts and actinomycetes for bioremediation. Results for the depth of cultivation on agar-agar inoculated with EM-4 showed the microorganisms growth in the concentrations between 0.2% and 1.0% of the Velpar K (R) in the gel. The analysis of high performance liquid chromatography ( HPLC) showed that the EM-4 was effective for the bioremediation of the herbicide, which reached the values of 80% for diuron and 70% for hexazinone after 21 days in solution of 2:1 of Velpar K (R)/EM-4 ratio. These results could be useful for planning the bioremediation of contaminated areas with Velpar K (R).

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Metabolic studies are very important to improve quality of functional dairy products. For this purpose, the behaviors of pure cultures of Streptococcus thermophilus (St) and Lactobacillus rhamnosus (Lr) as well a co-culture of them (St-Lr) were investigated during skim milk fermentation, and the inulin effect as prebiotic was assessed. Lr was able to metabolize 6 g/100 g more galactose than St and St-Lr. Final lactic acid production by Lr was higher (9.8 g/L) compared to St (9.1 g/L) and St-Lr (9.1 g/L). Acetic acid concentration varied from 0.8 g/L (St-Lr) to 1.5 g/L (Lr) and that of ethanol from only 0.2 g/L (St-Lr) to 0.4 g/L (Lr), which suggests the occurrence in Lr of a NADH oxidase activity and citrate co-metabolization via pyruvate, both dissipating a part of the reducing power. Diacetyl and acetoin accumulated at the highest levels (18.4 and 0.8 mg/L, respectively) with St-Lr, which suggests possible synergistic interactions between these microorganisms as well as the Lr capability of co-metabolizing citrate in the presence of lactose. Inulin stimulated both biomass growth and levels of all end-products, as the likely result of fructose release from its partial hydrolysis and subsequent metabolization as an additional carbon and energy source. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.

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To shed light on the interactions occurring in fermented milks when using co-cultures of Streptococcus thermophilus with Lactobacillus bulgaricus (StLb) or Lactobacillus acidophilus (StLa), a new co-metabolic model was proposed and checked either in the presence of Inulin as a prebiotic or not. For this purpose, the experimental data of concentrations of substrates and fermented products were utilized in balances of carbon, reduction degree and ATP. S. thermophilus exhibited always quicker growth compared to the other two microorganisms, while the percentage of lactose fermented to lactic acid, that of galactose metabolized, and the levels of diacetyl and acetoin formed strongly depended on the type of co-culture and the presence of inulin. The StLb co-culture led to higher acetoin and lower diacetyl levels compared to StLa, probably because of more reducing conditions or limited acetoin dehydrogenation. Inulin addition to StLa suppressed acetoin accumulation and hindered that of diacetyl, suggesting catabolite repression of alpha-acetolactate synthase expression in S. thermophilus. Both co-cultures showed the highest ATP requirements for biomass growth and maintenance at the beginning of fermentation, consistently with the high energy demand of enzyme induction during lag phase. Inulin reduced these requirements making biomass synthesis and maintenance less energy-consuming. Only a fraction of galactose was released from lactose, consistently with the galactose-positive phenotype of most dairy strains. The galactose fraction metabolized without inulin was about twice that in its presence, which suggests inhibition of the galactose transport system of S. thermophilus by fructose released from partial inulin hydrolysis. (C) 2012 Elsevier B.V. All rights reserved.

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Nisin is a promising alternative to chemical preservatives for use as a natural biopreservative in foods. This bacteriocin has also potential biomedical applications. Lactic acid bacteria are commonly cultivated in expensive standard complex media. We have evaluated the cell growth and nisin production of Lactococcus lactis in a low-cost natural medium consisting of diluted skimmed milk in a 2-L bioreactor. The assays were performed at 30 degrees C for 56 h, at varying agitation speeds and airflow rates: (1) 200 rpm (no airflow, and airflow at 0.5, 1.0 and 2.0 L/min); (2) 100 rpm (no airflow, and airflow at 0.5 L/min). Nisin activity was evaluated using agar diffusion assays. The highest nisin concentration, 49.88 mg/L (3.3 log AU/mL or 1,995.29 AU/mL), was obtained at 16 h of culture, 200 rpm and no airflow (k(L)a = 5.29 x 10(-3)). These results show that a cultivation medium composed of diluted skimmed milk supports cell growth to facilitate nisin biosynthesis.

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The aim of this study was to evaluate the potential application of biodegradable nanoparticles containing a photosensitizer in photodynamic therapy. The poly (D,L lactic-co-glycolic acid) nanoparticles were studied by steady-state techniques, time-resolved fluorescence, and laser flash photolysis. The external morphology of the nanoparticles was established by scanning electron microscopy, and the biological activity was evaluated by in vitro cell culture by 3-(4,5 dimethylthiazol-2,5 biphenyl) tetrazolium bromide assay. The particles were spherical in shape exhibiting a 435 nm diameter with a low tendency to aggregate. The loading efficiency was 77%. The phthalocyanine-loaded-nanoparticles maintained their photophysical behavior after encapsulation. The cellular viability was determined, obtaining 70% of cellular death. All the performed physical-chemical, photophysical, and photobiological measurements indicated that the phthalocyanine-loaded-nanoparticles are a promising drug delivery system for photodynamic therapy and photoprocesses. (C) 2012 Laser Institute of America.

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Antitumor activities have been described in selol, a hydrophobic mixture of molecules containing selenium in their structure, and also in maghemite magnetic nanoparticles (MNPs). Both selol and MNPs were co-encapsulated within poly(lactic-co-glycolic acid) (PLGA) nanocapsules for therapeutic purposes. The PLGA-nanocapsules loaded with MNPs and selol were labeled MSE-NC and characterized by transmission and scanning electron microscopy, electrophoretic mobility, photon correlation spectroscopy, presenting a monodisperse profile, and positive charge. The antitumor effect of MSE-NC was evaluated using normal (MCF-10A) and neoplastic (4T1 and MCF-7) breast cell lines. Nanocapsules containing only MNPs or selol were used as control. MTT assay showed that the cytotoxicity induced by MSE-NC was dose and time dependent. Normal cells were less affected than tumor cells. Cell death occurred mainly by apoptosis. Further exposure of MSE-NC treated neoplastic breast cells to an alternating magnetic field increased the antitumor effect of MSE-NC. It was concluded that selol-loaded magnetic PLGA-nanocapsules (MSE-NC) represent an effective magnetic material platform to promote magnetohyperthermia and thus a potential system for antitumor therapy.

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The effect of the addition of passion fruit peel powder (PFPP) on the fermentation kinetics and texture parameters, post-acidification and bacteria counts of probiotic yoghurts made with two milk types were evaluated during 28 days of storage at 4 degrees C. Milks were fermented by Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (CY340), and one strain of probiotic bacteria: Lactobacillus acidophilus (L10 and NCFM), Bifidobacterium animalis subsp. lactis (8104 and HN019). The addition of PFPP reduced significantly fermentation time of skim milk co-fermented by the strains L10, NCFM and HN019. At the end of 28-day shelf-life, counts of B. lactis Bl04 were about 1 Log CFU mL(-1) higher in whole yoghurt fermented with PFPP regarding its control but, in general, the addition of PFPP had less influence on counts than the milk type itself. The titratable acidity in yoghurts with PFPP was significantly higher than in their respective controls, and in skim yoghurts higher than in the whole ones. The PFPP increased firmness, consistency (except for the NCFM strain of L acidophilus) and cohesiveness of all skim yoghurts. The results point out the suitability of using passion fruit by-product in the formulation of both skim and whole probiotic yoghurts. (C) 2012 Elsevier Ltd. All rights reserved.

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We investigated the effect of increased glucose oxidase concentration as a technological option to decrease oxidative stress during the processing of probiotic yogurts. Probiotic yogurts were produced with increased concentrations of glucose oxidase (0, 250, 500, 750, or 1,000 mg/kg) and submitted to physicochemical and microbiological analysis at 1, 15, and 30 d of refrigerated storage. Higher concentrations of glucose oxidase (750 and 1,000 mg/kg) and a longer storage time were found to have an influence on the characteristics of the probiotic yogurt, contributing to more extensive post-acidification, an increase in the dissolved oxygen level, and higher proteolysis. In addition, increased production of aroma compounds (diacetyl and acetaldehyde) and organic acids (mainly lactic acid) and a decrease in the probiotic bacteria count were reported. The use of glucose oxidase was a feasible option to minimize oxidative stress in probiotic yogurts. However, supplementation with excessive amounts of the enzyme may be ineffective, because insufficient substrate (glucose) is present for its action. Consumer tests should be performed to evaluate changes in the sensory attributes of the probiotic yogurts with increased supplementation of glucose oxidase. In addition, packaging systems with different permeability to oxygen should be evaluated.

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Contents Among the modifications that occur during the neonatal period, pulmonary development is the most critical. The neonate's lungs must be able to perform adequate gas exchange, which was previously accomplished by the placenta. Neonatal respiratory distress syndrome is defined as insufficient surfactant production or pulmonary structural immaturity and is specifically relevant to preterm newborns. Prenatal maternal betamethasone treatment of bitches at 55days of gestation leads to structural changes in the neonatal lung parenchyma and consequently an improvement in the preterm neonatal respiratory condition, but not to an increase in pulmonary surfactant production. Parturition represents an important challenge to neonatal adaptation, as the uterine and abdominal contractions during labour provoke intermittent hypoxia. Immediately after birth, puppies present venous mixed acidosis (low blood pH and high dioxide carbon saturation) and low but satisfactory Apgar scores. Thus, the combination of physiological hypoxia during birth and the initial effort of filling the pulmonary alveoli with oxygen results in anaerobiosis. As a neonatal adaptation follow-up, the Apgar analysis indicates a tachypnoea response after 1h of life, which leads to a shift in the blood acidbase status to metabolic acidosis. One hour is sufficient for canine neonates to achieve an ideal Apgar score; however, a haemogasometric imbalance persists. Dystocia promotes a long-lasting bradycardia effect, slows down Apgar score progression and aggravates metabolic acidosis and stress. The latest data reinforce the need to accurately intervene during canine parturition and offer adequate medical treatment to puppies that underwent a pathological labour.

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The aim of this study was to evaluate the blood gas profile of experimentally copper-poisoned sheep (in the pre-hemolytic, hemolytic and post-hemolytic phases) that have been treated or not treated with ammonium tetrathiomolybdate. Ten lambs of the Santa Ines breed were divided into two groups: control and ATTM (treated (ammonium tetrathiomolibydate). The animals were submitted to increasing doses of copper sulfate until macroscopic hemoglobinuria was detected. All of the control animals from died within four days of hemolytic crisis, and one sheep from ATTM died during the treatment. There was no difference in blood gas parameters between experimental groups. Higher values of pCO(2) were observed during the hemolytic crisis (HC) in both groups. The control group had higher mean values of hCO(3) in the times HC and 2 days after hemolytic crisis (dA) when compared with the time 15 before hemolytic crises (dB). The sheep that were treated with ATTM presented lower values of hCO(3) at 7dB and higher levels at the HC. The control and ATTM groups exhibited higher values of BE during the HC. Poisoning resulted in disorder in the acid-base equilibrium, characterized by metabolic alkalosis and respiratory acidosis. Treatment with ATTM was able to reverse the changes in acid-base balance in copper poisoning sheep.

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The incorporation of the curcumin into poly(lactic-co-glycolic)acid (PLGA) nanospheres by the nanoprecipitation technique, the characterization of the nanoparticles and the schistosomicidal activity of the curcumin-loaded into PLGA nanospheres were reported. The incorporation process occurred with high efficiency and the images of field-emission scanning electron microscopy (FESEM) revealed the production of spherically shaped particles. According to the dynamic light scattering measurements, the particles are nanometric and monodisperse. The curcumin-loaded PLGA nanoparticles (50 and 100 mu M) caused the death of all worms and a separation between 50% and 100% of Schistosoma mansoni couples at concentrations from 30 mu M. Moreover, the curcumin-loaded PLGA nanoparticles also decreased the motor activity and caused partial alterations in the tegument of adult worms. This study marks the first time that schistosomicidal activity has been reported for curcumin-loaded PLGA nanoparticles.