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The objective of this study was to evaluate the immobilization of lipase on a chitosan support by physical adsorption, aiming at its application in hydrolytic and synthetic reactions. Two types of chitosan (flakes and porous) were used for immobilizing lipase from a microbial source (Candida rugosa) and animal cells (porcine pancreas). The best results for recovery of total activity after immobilization were obtained for microbial lipase and porous chitosan beads. This set was selected for further immobilization studies, including full characterization of the immobilized derivative in aqueous and organic media. In aqueous medium, the operational and thermal stabilities of this preparation were quantified. In organic medium, the direct synthesis of n-butyl butyrate in organic solvent was chosen as a model reaction. The influence of several parameters, such as temperature, initial butyric acid concentration and amount of enzyme in the reaction system, was analyzed. Production of n-butyl butyrate was optimized and an ester yield response equation was obtained, making it possible to predict ester yields from known values of the three main factors. Use of this immobilized preparation was extended to the direct esterification of a large range of carboxylic acids (from C2 to C12) with a variety of alcohols (from C2 to C10).

Microbial lipase from Candida rugosa immobilized into porous chitosan beads was tested for esterification selectivity with butanol and different organic acids (C2–C12), and butyric acid and different aliphatic alcohols (C2–C10). After 24 h, the acids tested achieved conversions of about 40–45%. Acetic acid was the only exception, and in this case butanol was not consumed. Different alcohols led to butyric acid conversions >40%, except for ethanol, in which case butyric acid was converted only 26%. The system’s butanol and butyric acid were selected for a detailed study by employing an experimental design. The influence of temperature, initial catalyst concentration, and acid:alcohol molar ratio on the formation of butyl butyrate was simultaneously investigated, employing a 23 full factorial design. The range studied was 37–50°C for temperature (X1), 1.25–2.5% (w/v) for the catalyst concentration (X2), and 1 and 2 for the acid:alcohol molar ratio (X3). Catalyst concentration (X2) was found to be the most significant factor and its influence was positive. Maximum ester yield (83%) could be obtained when working at the lowest level for temperature (37°C), highest level for lipase concentration (2.5% [w/v]), and center level of acid:alcohol molar ratio (1.5). The immobilized lipase was also used repeatedly in batch esterification reactions of butanol with butyric acid, revealing a half-life of 86 h.

Objetivo: descrever os fatores de risco associados á gravidez na adolescência. Métodos: trata-se de estudo transversal. Desenvolvido com 207 adolescentes, gestantes ou puérperas, internadas em uma maternidade pública de referência no Piauí. A coleta de dados foi realizada durante os meses de fevereiro a maio de 2016. Resultados: o estudo evidenciou que os fatores associados com a gravidez na adolescência foram: baixa escolaridade; baixa frequência e desempenho escolar, especialmente entre adolescentes de 15 a 19 anos; ocupação, que entre a faixa etária de 15 a 19 anos predominaram as donas de casa, e entre 10 a 14 anos as estudantes; e violência intrafamiliar, mais incidente entre adolescentes de 10 a 14 anos. Conclusão: os dados obtidos nesse estudo foram bastante relevantes, pois deixaram evidente que a educação é uma fator primordial para prevenção da gravidez na adolescência, uma vez que, esta predominantemente ocorre entre adolescentes com baixa escolaridade ou que deixaram de frequentar a escola e se ocupam no cuidado ao lar.

Lecitase Ultra (a quimeric fosfolipase commercialized by Novozymes) has been immobilized via two different strategies: mild covalent attachment on cyanogen bromide agarose beads and interfacial activation on octyl-agarose beads. Both immobilized preparations have been submitted to different individual or cascade chemical modifications (amination, glutaraldehyde or 2,4,6-trinitrobenzensulfonic acid (TNBS) modification) in order to check the effect of these modifications on the catalytic features of the immobilized enzymes (including stability and substrate specificity under different conditions). The first point to be remarked is that the immobilization strongly affects the enzyme catalytic features: octyl-Lecitase was more active versus p-nitrophenylbutyrate but less active versus methyl phenylacetate than the covalent preparations. Moreover, the effects of the chemical modifications strongly depend on the immobilization strategy used. For example, using one immobilization protocol a modification improves activity, while for the other immobiled enzyme is even negative. Most of the modifications presented a positive effect on some enzyme properties under certain conditions, although in certain cases that modification presented a negative effect under other conditions. For example, glutaraldehyde modification of immobilized or modified and aminated enzyme permitted to improve enzyme stability of both immobilized enzymes at pH 7 and 9 (around a 10-fold), but only the aminated enzyme improved the enzyme stability at pH 5 by glutaraldehyde treatment. This occurred even though some intermolecular crosslinking could be detected via SDS-PAGE. Amination improved the stability of octyl-Lecitase, while it reduced the stability of the covalent preparation. Modification with TNBS only improved enzyme stability of the covalent preparation at pH 9 (by a 10-fold factor)., We gratefully recognize the support from the Spanish Government, grant CTQ2009-07568, grant VIE cod 5706 (UIS-Colombia) and CNPq (Brazil). The predoctoral fellowships for Ms. García-Galán (Spanish Government) and Mr dos Santos (CNPq, Brazil) are also recognized. Dr Pereira thanks Fundación Carolina and UNIFAL-MG.

The search for an inexpensive support has motivated our group to undertake this work dealing with the use of chitosan as matrix for immobilizing lipase. In addition to its low cost, chitosan has several advantages for use as a support, including its lack of toxicity and chemical reactivity, allowing easy fixation of enzymes. In this article, we describe the immobilization of Candida rugosa lipase onto porous chitosan beads for the enzymatic hydrolysis of olive oil. The binding of the lipase onto the support was performed by physical adsorption using hexane as the dispersion medium. A comparative study between free and immobilized lipase was conducted in terms of pH, temperature, and thermal stability. A slightly lower value for optimum pH (6.0) was found for the immobilized form in comparison with that attained for the soluble lipase (7.0). The optimum reaction temperature shifted from 37 degrees C for the free lipase to 50 degrees C for the chitosan lipase. The patterns of heat stability indicated that the immobilization process tends to stabilize the enzyme. The half-life of the soluble free lipase at 55 degrees C was equal to 0.71 h (Kd = 0.98 h(-1)), whereas for the immobilized lipase it was 1.10 h (Kd = 0.63 h(-1)). Kinetics was tested at 37 degrees C following the hydrolysis of olive oil and obeys the Michaelis-Menten type of rate equation. The Km was 0.15 mM and the Vmax was 51 micromol/(min x mg), which were lower than for free lipase, suggesting that the apparent affinity toward the substrate changes and that the activity of the immobilized lipase decreases during the course of immobilization.

ResumoUm caso de hematoma na intradural espinal espontâneo ao nível de T11-12, simulando um quadro de tumor, é relatado. O diagnóstico de processo expansivo intradural extramedular foi feito por meio de ressonância magnética. O exame histopatológico confirmou tratar-se de hematoma organizado. Hematomas espinais espontâneos são raros, e os casos descritos referem-se a hematomas extradurais. Não encontramos na literatura pesquisada hematoma intradural espinal espontâneo.

The effect of dexamethasone (a synthetic glucocorticoid) on the activity of antioxidant enzymes (superoxide dismutase (SOD), catalase and glutathione peroxidase) of the lymphoid organs (mesenteric lymph nodes (MLN), spleen and thymus) was investigated. For comparison with non-immune tissues, skeletal muscles (soleus and gastrocnemius (GC) were also studied. As an indication of the occurrence of lipid peroxidation, the content of thiobarbituric acid reactant substances (TBARs) was also determined. Dexamethasone treatment decreased the TBARs content of the lymphoid organs and raised it in the GC and soleus muscles. The activity of Cu/Zn-SOD was reduced in all tissues. However, the activity of Mn-SOD was decreased in the MLN and soleus muscle only. The activity of catalase was reduced in the MLN and thymus and raised in the spleen and GC and soleus muscles. The imposed treatment raised the activity of GPX in the MLN, thymus and spleen and reduced it in GC and soleus muscles. These data led us to postulate that the mechanism for the therapeutic effect of glucocorticoids as antiinflammatory and immunosuppressive agents might include modification of antioxidant enzyme activities.

Thiobarbituric acid reactant substances (TBARs) content, and the activities of glucose-6-phosphate dehydrogenase (G6PDh), citrate synthase (CS), Cu/Zn- and Mn-superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) were measured in the lymphoid organs (thymus, spleen, and mesenteric lymph nodes (MLN)) and skeletal muscles (gastrocnemius and soleus) of adrenodemedullated (ADM) rats. The results were compared with those obtained for sham-operated rats. TBARs content was reduced by adrenodemedullation in the lymphoid organs (MLN) (28%), thymus (40%) and spleen (42%)) and gastrocnemius muscle (67%). G6PDh activity was enhanced in the MLN (69%) and reduced in the spleen (28%) and soleus muscle (75%). CS activity was reduced in all tissues (MLN (75%), spleen (71%), gastrocnemius (61%) and soleus (43%)), except in the thymus which displayed an increment of 56%. Cu/Zn-SOD activity was increased in the MLN (126%), thymus (223%), spleen (80%) and gastrocnemius muscle (360%) and was reduced in the soleus muscle (31%). Mn-SOD activity was decreased in the MLN (67%) and spleen (26%) and increased in the thymus (142%), whereas catalase activity was reduced in the MLN (76%), thymus (54%) and soleus muscle (47%). It is particularly noteworthy that in ADM rats the activity of glutathione peroxidase was not detectable by the method used. These data are consistent with the possibility that epinephrine might play a role in the oxidative stress of the lymphoid organs. Whether this fact represents an important mechanism for the establishment of impaired immune function during stress remains to be elucidated.

Three different approaches for lipase catalysed synthesis of citronellyl acetate by a commercial available immobilized lipase have been studied: a) direct esterification reaction of citronellol with acetic acid; b) alcoholysis of butyl acetate with citronellol and c) transesterification of citronellyl butyrate with butylacetate. Heptane was used as solvent for all the experiments. The extent of reaction occurred in the order alcoholysis>transesterification>esterification. Substrate partitioning between the immobilization support and the organic medium seems to greatly influence the catalytic performance of this enzyme preparation. Production of citronellyl acetate, was found to be dependent on the partition coefficient of the acyl donor which account the greatest value for the acetic acid.

This study examined the effects of glycocorticoids, insulin, thyroxine, and epinephrine upon the activities of CuZn- and Mn-superoxide dismutases (SOD), catalase, and glutathione peroxidase (GPX) and upon hydrogen peroxide production in rat macrophages obtained from the intraperitoneal cavity. The experiments were performed in vivo under conditions causing hormonal dysfunctions: adrenal demedullation, dexamethasone treatment, thyroidectomy, administration of L-tri-iodothyronine (T3) and L-thyroxine (T4), and diabetes. Macrophages were also cultured for 24 hr in the presence of dexamethasone, thyroid hormones, and insulin as to evaluate possible interferences caused in vivo by changes in other hormones. The results indicated that these hormones do control the activities of the antioxidant enzymes and hydrogen peroxide production both in vivo and in vitro. Insulin increased the activities of CuZn-SOD, catalase, and GPX and reduced that of Mn-SOD. Thyroid hormones raised the activities of CuZn- and Mn-SOD and decreased that of GPX, whereas glucocorticoids reduced both Mn-SOD and GPX. The removal of the adrenal medulla caused a decrease of Mn-SOD and GPX activities in the macrophages. Hydrogen peroxide production was increased by insulin and reduced by thyroid hormones and glucocorticoids. The changes in antioxidant enzyme activities caused by these hormones in macrophages may indicate important mechanisms for the establishment of impaired immune function in endocrine pathologies.

Reports about relationship on renal function and vancomycin exposure are conflicted and limited. Goals: To identify if high serum vancomycin levels precede changes in serum creatinine or if it is secondary to reduced glomerular filtration and to analyze associated clinical conditions. Methods: retrospective cohort study, initially of 56.555 measurements of vancomycin levels from 511 patients admitted from December 2011 to June 2012 was analyzed. Patients with uncompleted dates were excluded and the correlation analysis was performed in 127 patients that were divided into four groups based on vancomycin levels (20 mg/mL) and creatinine (1.4 mg/dL) levels. After that, 80 medical charts of these patients was reviewed for the presence of comorbidities, sepsis, acute kidney injury and use of other nephrotoxic drugs. Results: there was a significant increase in vancomycin levels, when creatinine > 1.4 mg/dL and vancomycin ≤ 20 mg/mL (Group 3) on the first measurement. It was identified there was a significant association between creatinine > 1.4 mg/mL and vancomycin > 20 mg/mL, n = 7 (Group 4) in patients aged 50–59 years. Acute kidney injury was present in patients with previous higher vancomycin levels. Conclusions: Impaired renal function occurred before vancomycin levels measurements were taken, influencing the serum levels of vancomycin in the following days. In these patients the elevation of vancomycin did not lead to a worsening in renal function. There was a positive correlation between elevated creatinine and vancomycin levels in elderly, male and septic. Patients who need more attention were those with acute kidney injury who have previous higher vancomycin levels.

O objetivo deste trabalho foi a produção de biodiesel via rota enzimática, utilizando resíduo gorduroso de fritura como substrato e o planejamento fatorial como ferramenta de análise. O planejamento fatorial foi empregado para avaliar os parâmetros da reação de transesterificação, quanto à razão molar óleo:etanol (1:3; 1:4,7; 1:9; 1:13,3 e 1:15) e temperatura (30, 34, 45, 56 e 60ºC). A reação foi conduzida em shaker, usando 20 g do meio reaciona e 2 g do derivado imobilizado de lipase durante 15h. Os diferentes ensaios foram avaliados por cromatografia gasosa (verificação do teor de ésteres de etila) e viscosímetro, mostrando uma produção de 67,9% de ésteres de etila para a razão molar óleo:etanol de 1:4,7 e 34ºC de temperatura; e uma viscosidade de 3,82 cP para a razão molar óleo:etanol de 1:3 e 45ºC de temperatura, sendo estes os melhores resultados, indicando que a variável que interferiu significativamente no rendimento da reação foi a temperatura.

Background Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old) immediately before and 5 and 60 min after the exhaustive Wingate test. Results Maximum anaerobic power was improved by acute creatine supplementation (10.5 %), but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP), leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Conclusions Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent) and inherent antioxidant activity of creatine.

The effect of swimming-training upon the activities of the enzymes involved in the generation of reducing-equivalents (citrate synthase-mitochondria and glucose-6-phosphate dehydrogenase-cytosol) and of antioxidant enzymes (CuZn- and Mn-SOD, catalase and glutathione peroxidase) in the lymphoid organs (thymus, mesenteric lymph nodes and spleen) was examined. The skeletal muscles (soleus-red and gastrocnemius-white) were also studied. Although our data suggest an apparently random, organ-specific change in enzymatic activity, some interesting trends can be observed. Firstly, the increased cirtrate synthase and Mn-SOD activities observed in red, but not in white muscle, corroborate the well-known effect of endurance exercise-training on mitochondrial oxidative metabolism. Secondly, there was an inverse relationship between TBARs-monitored lipoperoxidation and glutathione peroxidase activity in all tissues studied, what is in accordance with the previous findings showing that such enzyme exerts the fine control of intracellular lipoperoxide concentration. Except in the case of the spleen, there was a trend for elevated glucose-6-phosphate dehydrogenase activity, coadjuvant of glutathione peroxidase in the antioxidant response to physical exercise in all tissues. Thirdly, Mn-SOD and catalase were conspicuously associated to oxidative stress in the thymus, while glutathione and catalase could be linked to this parameter in the spleen. Fourthly, the lymph nodes seem to be more dependent on the glucose-6-phosphate dehydrogenase/glutathione peroxidase pair for protection against damage promoted by physical exercise. Mn-SOD and catalase activities were lower in the lymph nodes after swimming training. Finally, the observed changes in antioxidant enzyme activities in the spleen, lymph nodes and thymus indicate that endurance training affects the aerobic metabolism of these immune-related organs. Whether these changes lead to the impaired immune function reported in exercise remains to be found.

This study examined the effect of experimental hyperand hypothyroidism on the superoxide dismutase, catalase and glutathione peroxidase activities of rat lymphoid organs (mesenteric lymph nodes, spleen and thymus) and muscles (soleus and gastrocnemius-white portion) for comparison. The capacity for the generation of reducing equivalents was also investigated: activities of glucose-6-phosphate dehydrogenase (pentose-phosphate pathway) and citrate synthase (Krebs cycle). Hyperthyroidism tended to enhance lipid peroxide content in all tissues. This effect may result from (1) a high capacity for the generation of reducing equivalents in cytosol and mitochondria and (2) a reduced activity of catalase in the lymphoid organs and of glutathione peroxidase in the muscles. The process of lipid peroxidation in these tissues caused by hyperthyroidism was probably slowed down by the augmentation of CuZn- and Mn-superoxide dismutase (Mn-SOD) activities observed under this condition. Hypothyroidism tended to diminish lipid peroxidation and did not affect citrate synthase and glucose-6-phosphate dehydrogenase activities in the lymphoid organs and muscles. Low levels of thyroid hormones tended to diminish Mn-SOD and glutathione peroxidase activities. These findings show that the thyroid hormones might be able to regulate the activities of CuZn- and Mn-SOD, and catalase and glutathione peroxidase in the lymphoid organs and skeletal muscles. Journal of Endocrinology (1994) 140, 73–77

Lipids-rich wastewater was partial hydrolyzed with porcine pancreas lipase and the efficiency of the enzymatic pretreatment was verified by the comparative biodegradability tests (crude and treated wastewater). Alternatively, simultaneous run was carried out in which hydrolysis and digestion was performed in the same reactor. Wastewater from dairy industries and low cost lipase preparation at two concentrations (0.05 and 0.5% w.v-1) were used. All the samples pretreated with enzyme showed a positive effect on organic matter removal (Chemical Oxygen Demand-COD) and formation of methane. The best results were obtained when hydrolysis and biodegradation were performed simultaneously, attaining high COD and color removal independent of the lipase concentration. The enzymatic treatment considerably improved the anaerobic operational conditions and the effluent quality (lower content of suspended solids and less turbidity). Thus, the use of enzymes such as lipase seemed to be a very promising alternative for treating the wastewaters having high fat and grease contents, such as those from the dairy industry.O presente trabalho teve como objetivo o pré-tratamento de efluente da indústria de laticínios na hidrólise de lipídeos, empregando lipase de fonte de células animais de baixo custo disponível comercialmente (pâncreas de porco) na formação de gás metano por biodegradabilidade anaeróbia empregando diferentes concentrações de lipase (0,05 e 0,5 % w.v-1). A utilização de lipase no pré-tratamento do efluente acelerou a hidrólise de lipídeos e, conseqüentemente, auxiliou o tratamento biológico resultando na redução da matéria orgânica em termos de Demanda Química de Oxigênio (DQO), cor e sólidos em suspensão como lipídeos. Os melhores resultados em termos de remoção de DQO e cor foram obtidos quando a hidrólise e biodigestão foram realizadas simultaneamente, independente da concentração de lipase empregada. Estes resultados mostram que a hidrólise e biodigestão podem ser realizadas simultaneamente empregando baixa concentração de lipase (0,05% w.v-1), contribuindo para a redução de custo e tempo no processo de biodegradação aneróbia.

Apesar da consolidação dos programas de pós-graduação stricto sensu em Educação Física (PPG-EF), críticas têm sido evidenciadas. Dentre as principais destacam-se a formação técnica e a especialização nos períodos iniciais de formação científica, a distância entre conhecimento produzido e sociedade e a valorização quantitativa da produção bibliográfica, orientando os objetivos da pesquisa para a publicação. Denominamos esse modo de produção científica de fordismo acadêmico. Assim, o objetivo do ensaio é discutir a orientação política dos PPG-EF e problematizar suas implicações para produção do conhecimento e a formação acadêmica. A ênfase na produção bibliográfica e a desvalorização da EF enquanto área de intervenção pode comprometer a formação crítica e resultar em descaracterização da área. Despite the consolidation of stricto sensu postgraduate programs in Physical Education (PP-PE), critics have been noted. Among the principal, it is pointed out the technical formation and specialization on the initial periods of scientific formation, the distance between knowledge and society, the emphasis on the quantitative bibliographic production, guiding the aim of research for publication. This form of scientific production is entitled as academic fordism. Thus, the aim of this essay is discuss the orientation politic of the PP-PE and your implication to knowledge production and academic formation. The emphasis on bibliographic production and the devaluation of the PE likes area of intervention may implicate on the critical formation and result in mischaracterization of area. Pese a la consolidación de los estudios de postgrado en Educación Física (PPG-EF), las críticas han sido frecuentes. Entre aquellas que son centrales, están la formación técnica y la especialización en los tiempos iniciales de formación científica, la lejanía entre la producción de conocimiento y de la sociedad, y la valoración cuantitativa de la producción bibliográfica, cuando se pone los objetivos de investigación bajo la orientación para la publicación. Llamamos a este modo de producción científica de fordismo académico. El objetivo de este ensayo es discutir la orientación política de PPG-EF y refletir sobre sus implicaciones para la producción de conocimiento y para la formación académica. El énfasis en la producción bibliográfica y la desvalorización de la EF como un espacio de intervención puede poner en peligro la formación crítica y resultar en una descaracterización del área.

Most resistance training programs use constant rest period lengths between sets and exercises, but some programs use decreasing rest period lengths as training progresses. The aim of this study was to compare the effect on strength and hypertrophy of 8 weeks of resistance training using constant rest intervals (CIs) and decreasing rest intervals (DIs) between sets and exercises. Twenty young men recreationally trained in strength training were randomly assigned to either a CI or DI training group. During the first 2 weeks of training, 3 sets of 10-12 repetition maximum (RM) with 2-minute rest intervals between sets and exercises were performed by both groups. During the next 6 weeks of training, the CI group trained using 2 minutes between sets and exercises (4 sets of 8-10RM), and the DI group trained with DIs (2 minutes decreasing to 30 seconds) as the 6 weeks of training progressed (4 sets of 8-10RM). Total training volume of the bench press and squat were significantly lower for the DI compared to the CI group (bench press 9.4%, squat 13.9%) and weekly training volume of these same exercises was lower in the DI group from weeks 6 to 8 of training. Strength (1RM) in the bench press and squat, knee extensor and flexor isokinetic measures of peak torque, and muscle cross-sectional area (CSA) using magnetic resonance imaging were assessed pretraining and posttraining. No significant differences (p < or = 0.05) were shown between the CI and DI training protocols for CSA (arm 13.8 vs. 14.5%, thigh 16.6 vs. 16.3%), 1RM (bench press 28 vs. 37%, squat 34 vs. 34%), and isokinetic peak torque. In conclusion, the results indicate that a training protocol with DI is just as effective as a CI protocol over short training periods (6 weeks) for increasing maximal strength and muscle CSA; thus, either type of program can be used over a short training period to cause strength and hypertrophy.

Calcineurin inhibitors exacerbate ischemic injury in transplanted kidneys, but it is not known if sirolimus protects or exacerbates the transplanted kidney from ischemic injury. We determined the effects of sirolimus alone or in combination with cyclosporin A (CsA) on oxygenated and hypoxic/reoxygenated rat proximal tubules in the following in vitro groups containing 6-9 rats per group: sirolimus (10, 50, 100, 250, 500, and 1000 ηg/mL); CsA (100 µg/mL); sirolimus (50 and 250 ηg/mL) + CsA (100 µg/mL); control; vehicle (20% ethanol). For in vivo studies, 3-week-old Wistar rats (150-250 g) were submitted to left nephrectomy and 30-min renal artery clamping. Renal function and histological evaluation were performed 24 h and 7 days after ischemia (I) in five groups: sham, I, I + SRL (3 mg·kg -1 ·day -1 , po ), I + CsA (3 mg·kg ·day , sc ), I + SRL + CsA. Sirolimus did not injure oxy-genated or hypoxic/reoxygenated proximal tubules and did not potentiate the tubular toxic effects of CsA. Neither drug affected the glomerular filtration rate (GFR) at 24 h. GFR was reduced in CsA-treated rats on day 7 (0.5 ± 0.1 mL/min) but not in rats receiving sirolimus + CsA (0.8 ± 0.1 mL/min) despite the reduction in renal blood flow (3.9 ± 0.5 mL/min). Acute tubular necrosis regeneration was similar for all groups. Sirolimus alone was not toxic and did not enhance hypoxia/reoxygenation injury or CsA toxicity to proximal tubules. Despite its hemodynamic effects, sirolimus protected post-ischemic kidneys against CsA toxicity.Key words: Cyclosporin A; Nephrotoxicity; Renal proximal tubules; Renal ischemia

Resumen en: The intention of this work was to evaluate the growth of Pseudomonas aeruginosa (C1 LBPVMA-UFAL) on lubricant oil and verify the production of rhamnolipi...

5-Aminolevulinic acid (ALA), a heme precursor that accumulates in acute intermittent porphyria patients and lead-exposed individuals, has previously been shown to autoxidize with generation of reactive oxygen species and to cause in vitro oxidative damage to rat liver mitochondria. We now demonstrate that chronically ALA-treated rats (40 mg/kg body wt every 2 days for 15 days) exhibit decreased mitochondrial enzymatic activities (superoxide dismutase, citrate synthase) in liver and soleus (type I, red) and gastrocnemius (type IIb, white) muscle fibers. Previous adaptation of rats to endurance exercise, indicated by augmented (cytosolic) CuZn-superoxide dismutase (SOD) and (mitochondrial) Mn-SOD activities in several organs, does not protect the animals against liver and soleus mitochondrial damage promoted by intraperitoneal injections of ALA. This is suggested by loss of citrate synthase and Mn-SOD activities and elevation of serum lactate levels, concomitant to decreased glycogen content in soleus and the red portion of gastrocnemius (type IIa) fibers of both sedentary and swimming-trained ALA-treated rats. In parallel, the type IIb gastrocnemius fibers, which are known to obtain energy mainly by glycolysis, do not undergo these biochemical changes. Consistently, ALA-treated rats under swimming training reach fatigue significantly earlier than the control group. These results indicate that ALA may be an important prooxidant in vivo.

1. The enolamine form of 5-aminolaevulinic acid (ALA), a haem precursor that accumulates in lead poisoning and in acute intermittent porphyria (AIP), undergoes fast autoxidation at slightly alkaline pH with concomitant generation of reactive oxygen species. 2. The transmembrane potential, Ca2+ ion fluxes and state-4 respiratory rate, of isolated rat liver mitochondria are severely affected by mM addition of ALA; the toxic role of ALA-produced oxygen radicals was demonstrated by use of appropriate scavengers. 3. Induction of superoxide dismutase biosynthesis in lead-exposed workers, in AIP carriers and in ALA-treated rats, is viewed as a protective response against oxygen radical toxicity. 4. 5-Aminolaevulinic acid-generated oxygen radicals, together with Pb-stimulated Fe-dependent lipid peroxidation, might be involved in the aetiology of the neuropsychiatric manifestations of both plumbism and acute intermittent porphyria.

Médicos, fisiologistas, bioquímicos, psicólogos e até profissionais envolvidos com exercício físico estão recentemente aumentando seus interesses pela dinâmica não-linear, uma teoria científica desenvolvida principalmente por matemáticos, que é genericamente conhecida por Teoria da Complexidade. Embora poucos trabalhos em Educação Física e Esporte utilizem esse paradigma para solucionar seus problemas, nota-se um crescente interesse por esse mesmo enfoque, principalmente em relação aos efeitos do exercício físico sobre mudanças na variabilidade e complexidade de séries temporais fisiológicas. Geralmente, tais mudanças se revelam na forma de queda em seu comportamento temporal, denotando diminuição na complexidade do organismo ou de componentes envolvidos especificamente na sua regulação. De acordo com a Teoria da Complexidade, por enfatizar interações não-lineares existentes em sistemas biológicos, verifica-se que não é importante apenas a elevação (supercompensação) de componentes do organismo com a prática de exercícios físicos, mas também aqueles que atrofiam (descompensação) paralelamente, porque podem contribuir para a ocorrência de perda de sincronia na funcionalidade desses sistemas. Assim, em oposição à ênfase que se dá no treinamento físico à repetição monótona de atividade física intensa e voltada para efeitos específicos positivos, que invariavelmente leva à simplificação do organismo, recomenda-se maior variação qualitativa e quantitativa nos exercícios praticados. O objetivo é preservar sua complexidade natural ou impedir que ocorra diminuição rápida com o envelhecimento. A presente revisão tem por objetivo, além de descrever a possível perda de complexidade com o treinamento físico, discutir alguns conceitos da Teoria da Complexidade de modo introdutório, com particular ênfase em tópicos envolvendo saúde e desempenho físico.

OBJETIVO: Verificar as alterações promovidas pela suplementação de creatina nas variáveis antropométricas e da resultante de força máxima dinâmica (RFMD) em universitários submetidos a oito semanas de treinamento de força. METODOLOGIA: Participaram deste estudo, 18 universitários do sexo masculino, com idade entre 19 e 25 anos. Antes do treinamento foram determinadas a estatura (cm), a massa corporal (kg) e testes de ação muscular voluntária máxima dinâmica (1AMVMD), os sujeitos foram assinalados a um dos dois grupos, A (creatina) e B (placebo), foi adotado o protocolo duplo-cego. Após oito semanas de treinamento de força, repetiu-se a bateria de testes do pré-treinamento. RESULTADOS: Após oito semanas, verificou-se que tanto no grupo A como no B houve alterações estatisticamente significantes (ES) na RFMD em todos os exercícios (p = 0,007 a 0,008). A análise da melhora percentual e do delta da RFMD, nos exercícios de agachamento, desenvolvimento e supino fechado, mostrou que o grupo A teve alterações positivas ES superiores ao grupo B (p = 0,008 a 0,038). A massa magra aumentou ES somente no grupo A (p = 0,038). Contudo, o percentual de gordura corporal não mostrou alterações em nenhum dos grupos. A relação entre a melhora percentual (MP) das circunferências (C) do braço e antebraço e a MP na RFMD do exercício de desenvolvimento foi ES (r = 0,481 e 0,546, respectivamente), bem como entre a MP na C da coxa e na MP da RFMD do exercício de agachamento (r = 0,619). CONCLUSÃO: Independente do suplemento ingerido o treinamento de força foi capaz de induzir ajustes positivos na RFMD; contudo, a suplementação de creatina mostrou-se mais eficiente que o placebo, induzindo a maior aumento percentual e de delta na força. OBJECTIVE: To verify the alterations promoted by creatine supplementation in the anthropometric variables and the resultant of dynamic maximum strength (RDMS) in college students submitted to 8 wk of strength training. METHODOLOGY: The sample consisted of 18 male college students, aged between 19 to 25 years. Height (cm), body mass (kg) and tests of maximum voluntary muscular action (1MVMA) weight in the squat were determined prior to the training. The subjects were divided in two groups: A (creatine) or B (placebo).The double-blind protocol was adopted. After 8 weeks of strength training, the tests battery from the pre-training was repeated. RESULTS: After 8 wk of training, it was verified that both groups had statistically significant (SS) alterations in the RDMS in all the exercises (p = 0.007 / 0.008). The analysis of the percentile improvement (PI) and the RDMS delta in the squat exercises, military press and close-grip-extensions, showed that group A had positive SS alterations higher than group B (p = 0.008 / 0.038). Lean body mass only SS increased in group A (p = 0.038). However, the percentage of body fat did not show alterations in none of the groups. The relationship between the PI of the arm and forearm circumferences (C) and the PI in the RDMS of the development exercise was SS (r = 0.481 and 0.546, respectively), as well as between the PI in the thigh C and the PI of the RDMS of the squat exercise (r = 0.619). CONCLUSION: Regardless the substance ingested, strength training was able to increase in RDMS; however, creatine supplementation was shown to be more efficient that the placebo, showing higher percentual and delta improvement in strength.

Chitin was functionalized with hexamethylenediamine followed by glutaraldehyde activation, and its capacity to bind Candida rugosa lipase was investigated. The loading of 250 units g(-1) support showed to be effective, resulting in a uniform enzyme fixation with high catalytic activity. Both free and immobilized lipases were characterized by determining the activity profile as a function of pH, temperature, and thermal stability. For the immobilized lipase, the influence of the reaction temperature and substrate polarity in nonconventional biocatalysis was also analyzed. Production of butyl esters was found to be dependent on the substrate partition coefficient, which accounts the greatest value for the system butanol and butyric acid. The highest enzyme activity was found for the system butanol and caprylic acid at a reaction temperature of 40 degrees C. Under such conditions, the operational stability tests indicated that a small enzyme deactivation occurs after 12 batches, revealing a biocatalyst half-life of 426.7 h.

The search for an inexpensive support has motivated our group to undertake this work dealing with the use of chitosan as matrix for immobilizing lipase. In addition to its low cost, chitosan has several advantages for use as a support, including its lack of toxicity and chemical reactivity, allowing easy fixation of enzymes. In this article, we describe the immobilization of Candida rugosa lipase onto porous chitosan beads for the enzymatic hydrolysis of olive oil. The binding of the lipase onto the support was performed by physical adsorption using hexane as the dispersion medium. A comparative study between free and immobilized lipase was conducted in terms of pH, temperature, and thermal stability. A slightly lower value for optimum pH (6.0) was found for the immobilized form in comparison with that attained for the soluble lipase (7.0). The optimum reaction temperature shifted from 37°C for the free lipase to 50°C for the chitosan lipase. The patterns of heat stability indicated that the immobilization process tends to stabilize the enzyme. The half-life of the soluble free lipase at 55°C was equal to 0.71 h (K d = 0.98h-1), whereas for the immobilized lipase it was 1.10 h (K d = 0.63h-1). Kinetics was tested at 37°C following the hydrolysis of olive oil and obeys the Michaelis- Menten type of rate equation. The K m was 0.15 mM and the V max was 51 µmol/ (min-mg), which were lower than for free lipase, suggesting that the apparent affinity toward the substrate changes and that the activity of the immobilized lipase decreases during the course of immobilization.

The enzymatic synthesis of selected low molecular weight esters such as acetate esters by direct esterification using acetic acid as acyl donor usually display low yields. The acetic acid changes the polarity of the reaction medium, which in this turn modifies the partitioning of water between the solid phase (enzyme preparation) and the liquid phase (substrate), resulting in its accumulation on the enzyme solid phase. This may reduce the enzyme´s local pH. Therefore, the enzyme active site is modified and the reaction became nearly impossible. Our previous work showed that there is a negative relationship between enzyme activity and substrate partition coefficient (Ps); that is, the higher the substrate partition coefficient the lower the amount of product formed. This work investigated the feasibility of minimizing this inhibition by replacing the esterification reaction for alcoholysis reaction using several acetate esters. This approach enhanced the reaction yields to 46%, which is about 3 times higher than that one obtained in the esterification route.

Orientador: Rui Curi Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia Resumo: O efeito da insulina, hormônios tiroidianos, glicocorticóides (dexametasona) e catecolaminas na atividade de enzimas antioxidantes (CuZn- e Mn- superoxido dismutase SOD, catalase e glutatione peroxidase - GPX) em macrófagos intraperitoneais residentes de ratos e órgãos linfóides (linfonodo mesentérico - LNM, timo e baço) foi investigado. Para tanto, ratos adultos foram submetidos à várias disfunções hormonais: diabetes, hiper e hipotiroidismo, tratamento com dexametasone e adrenodesmedulação. O efeito dos hormônios em macrófagos cultivados também foi avaliado. Além dos estudos sobre atividade de enzimas antioxidantes, a produção de peróxido de hidrogênio (H202) por macrófagos foi determinada in vivo e in vitro. Em macrófagos: 1) a insulina aumentou a atividade da CuZn-SOD, catalase e GPX mas reduziu a da Mn-SOD, 2) os hormônios tiroidianos elevaram a atividade da CuZn- e Mn-SOD mas diminuiu a da GPX, enquanto que a dexametasona reduziu a da Mn-SOD e GPX, 3) a remoção da medula adrenal promoveu diminuição da atividade da Mn-SOD e GPX, 4) a produção de H202 foi aumentada pela insulina mas reduzida pelos hormônios tiroidianos e dexametasona. A indução do diabetes causou as seguintes mudanças de atividade das enzimas antioxidantes em órgãos linfóides: redução (exceto para GPX) no baço, aumento (exceto para a Mn-SOD) no timo, queda da Mn-SOD e catalase mas aumento da GPX no LNM; todas essas alterações foram revertidas pelo tratamento com insulina e permaneceu inalterada pela normoglicemia. O hipertiroidismo provocou elevação das atividades da CuZn- e Mn-SOD e diminuição da atividade da catalase nos órgãos linfóides. O tratamento com dexametasona causou: 1) queda da atividade da CuZn-SOD em todos os órgãos linfóides e da Mn-SOD no LNM, 2) redução da atividade da catalase no LNM e timo e aumento no baço, 3) aumento da atividade da GPX no LNM, timo e baço. A adrenodesmedulação elevou a atividade da CuZn-SOD em todos os órgãos linfóides, diminuiu a atividade da Mn-SOD no LNM e baço mas elevou no timo, enquanto que a atividade da catalase foi reduzida no LNM e timo e a atividade da GPX tornou-se indetectável nestas condições. Esses dados indicam que a atividade das enzimas antioxidantes é alterada pela insulina, hormônios tiroidianos, glicocorticóides e adrenalina. Essas alterações enzimáticas e metabólicas são tecidoespecíficas e podem desempenhar papel importante nas modificações da funcionalidade imunitária que geralmente acompanham as disfunções endócrinas envolvendo esses hormônios Abstract: The effect of insulin, thyroid hormones, glucocorticoids (dexamethasone) and catecholamines on the activity of antioxidant enzymes (CuZn- and Mn-superoxide dismutase - SOD, catalase, and glutathione peroxidase - GPX) in rat resident intraperitoneal macrophages and lymphoid organs (mesenteric lymph nodes - MLN, thymus, and spleen) was investigated. For this purpose, aduIt rats were submitted to various hormonal disfunctions such as diabetes, hyper and hypothyroidism, dexamethasone treatment and adrenodemedullation. The effect of the hormones on macrophage cuItures was also examined. In addition to the antioxidant enzyme assays, the production of hydrogen peroxide (H202) by macrophages was determined both in vivo and in vitro. In macrophages: 1) Insulin raised the activity of CuZn-SOD, catalase and GPX but reduced that of Mn-SOD, 2) Thyroid hormones increased the activity of CuZn- and Mn-SOD but decreased that of GPX, whereas dexamethasone diminished both Mn-SOD and GPX activities, 3) The removal of adrenal medulla caused a marked decrease of Mn-SOD and GPX activities, 4) H202 production was increased by insulin but reduced by thyroid hormone and dexamethasone treatment. The induction of diabetes caused the following changes in antioxidant enzyme activities of the lymphoid organs: Reduction (except for GPX) in the spleen, increase (except for Mn-SOD) in the thymus, decrease of Mn-SOD and catalase but increase of GPX in the MLN; all these changes were reversed by insulin treatment and remained unchanged under normoglycemia. The hyperthyroidism provoked an elevation of CuZn- and Mn-SOD activities and decrease of catalase in all lymphoid organs. Dexamethasone treatment caused: 1) A decrease of CuZn-SOD activity in all lymphoid organs and of Mn-SOD in the MLN, 2) A reduction of catalase activity in the MLN and thymus and an increase in the spleen, 3) An augmentation of GPX activity in the MLN, thymus and spleen. Adrenodemedullation raised CuZn-SOD activity in all lymphoid organs, decreased the activity of Mn-SOD in the MLN and spleen but increased the latter activity in the thymus, whereas catalase activity was reduced in the MLN and thymus and GPX activity became undetectable under these conditions. These findings support the proposition that the antioxidant enzyme activities are aItered by insulin, thyroid hormones, glucocorticoids and adrenalin. These metabolic changes are tissue-specific and might play a role in the impairment of the immune function under endocrine disfunctions involving these hormones Doutorado Fisiologia Doutor em Ciências

BACKGROUND: Ankle-brachial index (ABI) can access peripheral artery disease and predict mortality in prevalent patients on hemodialysis. However, ABI has not yet been tested in incident patients, who present significant mortality. Typically, ABI is measured by Doppler, which is not always available, limiting its use in most patients. We therefore hypothesized that ABI, evaluated by a simplified method, can predict mortality in an incident hemodialysis population. METHODOLOGY/PRINCIPAL FINDINGS: We studied 119 patients with ESRD who had started hemodialysis three times weekly. ABI was calculated by using two oscillometric blood pressure devices simultaneously. Patients were followed until death or the end of the study. ABI was categorized in two groups normal (0.9-1.3) or abnormal (1.3). There were 33 deaths during a median follow-up of 12 months (from 3 to 24 months). Age (1 year) (hazard of ratio, 1.026; p = 0.014) and ABI abnormal (hazard ratio, 3.664; p = 0.001) were independently related to mortality in a multiple regression analysis. CONCLUSIONS: An easy and inexpensive technique to measure ABI was tested and showed to be significant in predicting mortality. Both low and high ABI were associated to mortality in incident patients on hemodialysis. This technique allows nephrologists to identify high-risk patients and gives the opportunity of early intervention that could alter the natural progression of this population.

Rats weighing 45–50 g were fed 3 diets for 8 wk: a balanced control diet (CD) consisting of 4% fat (polyunsaturated/saturated fatty acids [P/S] ratio 2.9/1) and two fat-rich diets: polyunsaturated (UD)—P/S 7.6/1 and saturated (SD) P/S 0.3/1. After 8 wk feeding on the respective diets, rats were subjected to swimming for 90 min at 30°C daily, 5 d/wk for 8 wk. At the end of this period, the rats were killed and the lymphoid organs (LO—thymus, spleen, and mesenteric lymph nodes) and muscles (soleus and gastrocnemius) removed for the measurement of TBARs (Thiobarbituric Acid Reactant Substances) content and of the activities of antioxidant enzymes (CuZn- and Mn-Superoxide dismutase.—SOD—, catalase, and glutathione peroxidase). To evaluate the changes in the sites of generation of reducing equivalents involved in the formation of free radicals, the activities of citrate synthase and glucose-6-phosphate dehydrogenase were measured. The exercise-training clearly modified the enzyme activities and TBARs content of the lymphoid organs and skeletal muscles, but this effect was dependent upon the diet given to the rats. However, fatty acid rich diets had presented a more pronounced effect on the studied aspects than did physical activity. Although one could expect a summatory effect of polyunsaturated fatty acid-rich diet and exercise-training, swimming increased the activities of CuZn- and Mn-SOD in almost all tissues from the elevated level promoted by fat-rich diets.

The effect of alloxan-induced diabetes on CuZn- and Mn-superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) activities, as well as the content of thiobarbituric acid reactive substances (TBARs) were examined in rat lymphoid organs (mesenteric lymph nodes (MLN), thymus and spleen) and, for comparison, red and white muscle fibres. The capacity for generation of reduced equivalents was also evaluated by measuring the activities of glucose-6-phosphate dehydrogenase (pentosephosphate pathway – cytosol) and citrate synthase (Krebs cycle – mitochondria). Diabetes raised the capacity for the generation of reducing equivalents in the lymphoid organs: in the mitochondria of the thymus and spleen and in the cytosol of the mesenteric lymph nodes and thymus. In muscles, diabetes reduced CuZn-SOD activity in soleus and raised the activity in gastrocnemius, and depressed the activities of catalase in soleus and of glutathione peroxidase in both soleus and gastrocnemius. In relation to the lymphoid organs, the spleen showed a decrease in the antioxidant enzyme activities (except for glutathione peroxidase), whereas the thymus showed an increased level (except for Mn-SOD), and the MLN presented a reduction in Mn-SOD and catalase activities and an increase in GPX activity caused by diabetes. The content of TBARs in the tissues followed the changes in GPX activity inversely: i.e. a decrease in the lymphoid organs (except in the spleen) and an increase in the muscles of diabetic rats compared with the control group. All these changes found in diabetic rats were reversed by insulin treatment and were not modified by the normalization of glycaemia. Journal of Endocrinology (1994) 142, 161–165

A Educação Física tem procurado se afirmar como disciplina acadêmica e profissão recorrendo a algumas estratégias. Por exemplo, tentou-se modificar o seu nome, caracterizar o seu objeto de estudo e desenvolver metodologia própria. Para o seu desenvolvimento enquanto profissão, não encontramos uma ampla discussão desta questão. Este ensaio teve por objetivo discutir o terceiro item através de uma ampla revisão dos principais métodos científicos disponíveis. Constatamos com isso que existe confusão entre métodos e técnicas entre os profissionais da Educação Física e que a metodologia ainda não desenvolveu um método científico isento de problemas

O paradigma adaptacionísta das Ciências Biológicas é o que normalmente serve de modelo teórico para explicar as mudanças de rendimento físico obtidas com o treinamento esportivo. Esta afirmação justifica-se pelo fato de a prática esportiva utilizar os princípios da sobrecarga e da especificidade adaplativa para obter esse efeito. Apesar de, a curto prazo, a aplicação destes princípios contribuir para melhorar o desempenho físico, a longo prazo, pode induzir o aparecimento da barreira de rendimento físico apresentada por atletas de alto nível, ou por indivíduos que se exercitam regularmente sem variar a atividade física. Esse problema pode ser exemplificado com a: a) perda progressiva da capacidade de elevar o rendimento físico com o treinamento de velocidade ou b) pela diminuição da capacidade de síntese de milocôndrias musculares com o treinamento da resistência aeróbia. De acordo com o paradigma da aulo-organização, para que o estímulo do exercício promova desestabilização homeoslática com supercompensação, o organismo deve possuir alto grau de coneclude entre as suas diversas partes constituintes. Entretanto, a especialização esportiva, por promover alterações orgânicas e celulares específicas, resultando em modificações da interação existente entre esses componentes do organismo, pode ser o principal fator responsável pelo aparecimento da barreira de rendimento físico. Neste trabalho, estamos propondo que o treinamento deve ser organizado de forma a permitir maior variabilidade de experiências motoras c de sobrecargas para reduzir o risco do surgimento precoce deste problema

O oxigênio consumido pelos organismos é reduzido à água de maneira tetravalente no interior das mitocôndrias celulares. Esta reação é catalisada pela enzima citocromo oxidase sem a liberação de oxiradicais (superóxido [ 0 2‘1 e hidroxil [O H ]) e peróxido de hidrogênio (H20 2). Entretanto, uma pequena percentagem deste oxigênio sofre redução unieletrônica no interior das células gerando estas espécies químicas altamente reativas e tóxicas, denominadas espécies reativas de oxigênio (EROs). Existem evidências de que o exercício físico ou o treinamento estimulam as principais vias metabólicas envolvidas na formação de EROs, a saber: respiração mitocondrial. degradação de bases purínicas seguida de oxidação pela xantina oxidase citoplasmática e o envolvimento de ferro e cobre. Em paralelo, observa-se queda das proteções enzimáticas e químicas do organismo contra EROs nesta condição. Como conseqüência, foi demonstrado lesões oxidativas por EROs acima do normal nos tecidos e órgãos de animais e humanos submetidos ao exercício físico ou treinamento. Nosso objetivo neste trabalho é revisar as principais evidências favoráveis a formação de EROs no organismo pelo exercício físico e treinamento, disponíveis na literatura especializada nesta área

A 36-year-old woman with a sudden history of low back pain radiating into the right lower extremity. The physical examination revealed paraparesis, saddle anesthesia and urinary incontinence. Magnetic resonance imaging revealed lipoma of the filum terminale (hyperintense sign within the filum terminale) (). The patient underwent surgery without delay with intraoperative neurophysiological monitoring (), and she had a full recovery of all neurological deficits. […] Cauda equina syndrome caused by filum terminale lipoma: magnetic resonance imaging features and surgical treatment

O soro resultante da produção de queijo, por possui alta carga orgânica e composição rica em lactose, proteínas, lipídios e minerais, apresenta potencial para uma série de aplicações mais nobres e ambientalmente favoráveis do que o seu despejo como rejeito. Dentre as aplicações possíveis do soro, encontram-se a sua utilização direta como substrato para produção de enzimas e, de forma indireta, na geração de energia, como, por exemplo, na produção de biogás por digestão anaeróbia. Neste último caso, a presença de lipídios pode limitar o processo. Portanto, destaca-se a importância das lipases na atuação da etapa de hidrólise da digestão anaeróbia, contribuindo para o processo de geração de energia. Dentro deste contexto, o presente estudo teve como objetivo avaliar a aplicação do soro de queijo na produção de lipases ligadas ao micélio e na geração de biogás. Para tal propósito, foram avaliados os fungos filamentosos Penicillium janthinellum CCT3162, Penicillium italicum AT4421 e Mucor circinelloides URM 4182, conhecidos por serem bons produtores de lipase ligada ao micélio. O estudo foi iniciado pela determinação das condições otimizadas da hidrólise do lipídio presente no soro, avaliando o efeito da linhagem fúngica, do carregamento de lipase (na forma de células íntegras), pH do meio e temperatura, por meio de planejamento experimental utilizando o método de Taguchi, com matriz L9 saturada. O fungo M. circinelloides foi selecionado como a fonte mais eficiente da enzima lipase, empregando soro de queijo como meio de cultivo. A suplementação do soro foi também avaliada, mas os aditivos utilizados (azeite de oliva, peptona e sais) não proporcionaram aumento significativo na atividade hidrolítica da lipase. A principal lipase gerada foi produzida a partir do meio de cultivo composto por soro de queijo integral, sem nenhum aditivo, por um período de incubação de 120 h. Algumas propriedades da lipase obtida foram pH ótimo de 7,5, temperatura ótima no intervalo de 40 a 60 °C e tempo de meia-vida com a relação à estocagem de 26,8 dias. Foram também analisados os parâmetros cinéticos da lipase quanto ao Km (115,74 mmol L-1 ) e Vmax (186,92 µmol g-1 min-1 ). O desempenho da lipase foi verificado na hidrólise do soro de queijo, apresentando preferência pela clivagem de ácidos graxos de menor cadeia carbônica (

O presente trabalho teve como objetivo a obtenção de ésteres com propriedades lubrificantes a partir de matérias-primas renováveis, como a biomassa microbiana, e um subproduto da indústria sucroalcooleira (óleo fúsel), avaliando a eficiência de catalisadores heterogêneos (bioquímicos e químicos) por meio de duas rotas catalíticas: 1) transesterificação do óleo microalgal empregando a lipase de Burkholderia cepacia (LBC) imobilizada em Nb2O5 e 2) transesterificação direta da biomassa microbiana catalisada por H3PMo12O40 impregnado em Nb2O5. O trabalho foi desenvolvido em cinco etapas. Inicialmente, a microalga Dunaliella salina foi cultivada em fotobiorreator de coluna de bolhas com capacidade de 10 L visando obtenção de material lipídico suficiente para as reações. Foram realizados 15 cultivos, obtendo-se um volume total de 150 L, correspondente a 172,5 g de biomassa e 32,76 g de material lipídico. Em seguida foram preparados os catalisadores propostos por protocolos já estabelecidos, sendo obtido para o catalisador químico acidez superficial de 5,644 mmol H+ g -1 e para o catalisador bioquímico elevada atividade hidrolítica (1400 ± 103 U g-1 ). Na terceira etapa, as reações de transesterificação por catálise bioquímica, empregando o óleo microalgal e diferentes aceptores do grupo acila (alcoóis etílico, butílico e isoamílico) óleo fúsel simulado e óleo fúsel foram conduzidas em reatores de vidro com capacidade de 50 mL, contendo 10 gramas de meio reacional à 45 °C e agitação magnética (150 rpm), durante um período máximo de 120 h, empregando iso-octano como solvente. Como reação controle foram efetuados testes com óleo de macaúba nas mesmas condições reacionais. A transesterificação direta da biomassa microalgal, empregando como catalisador H3PMo12O40 impregnado em Nb2O5 foi a quarta etapa do trabalho, em que as reações foram conduzidas em reator pressurizado (Parr Série 5500), a 250 °C, agitação de 300 rpm e razão molar 1:180 material lipídico/aceptor do grupo acila. Finalmente, os produtos obtidos foram purificados e quantificados por cromatografia gasosa, RMN 1H, viscosimetria e teor de glicerídeos. Os resultados obtidos demonstraram o potencial da microalga Dunaliella salina na produção de biolubrificantes, visto que ambos os catalisadores (químico e bioquímico) atuaram de forma eficiente convertendo os ácidos graxos presentes no óleo microalgal nos ésteres alquílicos correspondentes. Apesar do desempenho similar dos catalisadores testados, a via química foi superior em relação à via bioquímica, fornecendo conversões mais elevadas (= 95 %) foram constatados baixos teores de monoacilgliceróis (=95 %) had low monoacylglycerol (

A estabilidade à oxidação é uma das propriedades mais importantes do biodiesel pois afeta a sua estabilidade durante o período de estocagem influenciando no desempenho do motor. As pesquisas atuais tendem a desenvolver aditivos antioxidantes para melhorar sua estabilidade. Algumas plantas exibem propriedades antioxidantes devido à sua composição química e que podem auxiliar nessa estabilização. O objetivo deste trabalho foi estudar a estabilidade termo oxidativa do biodiesel de soja e do sebo bovino puro e aditivado com folhas e extrato das folhas de acerola, graviola, manga e pitanga frente à luz, a 60º C e a baixas temperaturas por 0, 168, 504, 1176 e 1848 h de estocagem de forma a avaliar o seu enquadramento dentro das normas ANP, ASTM, EN. As folhas usadas como aditivo antioxidante foram moídas num moinho de facas a 10 mesh e os extratos das folhas foram obtidos pelo processo Soxhlet. O biodiesel de soja foi obtido pela rota etílica e o de sebo bovino pela metílica. A estabilidade termo oxidativa foi monitorada determinando-se o índice de acidez, a viscosidade cinemática, a densidade, por espectroscopia no infravermelho com Transformada de Fourier e por termogravimetria. Os resultados mostraram que o biodiesel de soja e do sebo bovino é estável frente à luz após 1848 h. O efeito antioxidante das folhas sobre o biodiesel de soja após 168 h de estocagem a 60º C segue a seguinte ordem: folhas de graviola > folhas de pitanga > folhas de manga > folhas de acerola, enquanto para o extrato das folhas tem-se: extrato das folhas de acerola> extrato das folhas de graviola>extrato das folhas de manga>extrato das folhas de pitanga, após 504h. Para o biodiesel de sebo bovino as folhas apresentaram a ordem: folhas de pitanga>folhas de acerola >folhas de manga>folhas de graviola, e para os extratos a ordem: extratos da folha de manga > extratos da folha de graviola >extratos da folha de pitanga>extratos da folha de acerola. O butil hidroxitolueno (BHT), antioxidante sintético, apresentou maior efeito antioxidante sobre o biodiesel de soja em relação às aditivações com folhas e seus extratos após 1176h. No biodiesel de sebo bovino, a atividade do BHT foi semelhante aos extratos das folhas de acerola, graviola e pitanga após 504h e o de manga após 1176h. A ordem da estabilidade do biodiesel de soja aditivado frente a baixas temperaturas foi: extrato de pitanga > extrato de manga > extrato de acerola > extrato de graviola. Os resultados dos testes em baixa temperatura indicam que o biodiesel de soja aditivado ou não pode ser usado em qualquer região do país para todas as estações do ano. O efeito dos extratos das folhas na estabilidade do biodiesel frente a baixas temperaturas foi: extratos das folhas de manga>extratos de acerola>extratos de graviola>extratos de pitanga. O biodiesel de sebo bovino puro apresenta menor estabilidade frente a baixas temperaturas em relação ao biodiesel de soja. Os resultados obtidos do IA, viscosidade cinemática, densidade, FTIR e TGA indicam que as folhas e extratos das folhas das frutas estudadas podem atuar como aditivos antioxidantes na estabilidade oxidativa do biodiesel. Oxidation stability is one of the most important properties of biodiesel because it affects their stability during the storage period influence on engine performance. Current research tend to develop antioxidant additives to improve their stability. Some plants have antioxidant properties due to their chemical composition and may assist in this stabilization. The aim of this study was to oxidative term stability of soybean biodiesel and pure beef tallow and spiked with leaves and extracts of the leaves of cherry, soursop, mango and cherry front light, 60 ° C and low temperatures for 0, 168, 504, 1176 and 1848 h of storage in order to evaluate its framework within the ANP, ASTM, EN. The leaves used as an antioxidant additive were ground in a knife mill to 10 mesh and extracts of leaves were obtained by Soxhlet process. Soybean biodiesel was obtained by the ethyl route and beef tallow by methyl. The term oxidative stability was monitored by determining the acid number, kinematic viscosity, density, by infrared spectroscopy with Fourier Transform and thermogravimetry. The results showed that the biodiesel soya and tallow is stable against the light for 1848 h. The antioxidant effect of leaves on soybean biodiesel after 168 h of storage at 60 ° C follows the following order: leaves of soursop> sheets of cherry> mango leaves> acerola leaves while for the leaves of the statement we have: extract leaves acerola> extract of the leaves of soursop> extract of mango leaves> extract of cherry leaves after 504h. For the leaves beef tallow biodiesel showed the order: leaves of cherry> leaves acerola> mango leaves> soursop leaves and extracts the order: Mango leaf extracts> soursop leaf extracts> leaf extracts of cherry> acerola leaf extracts. The butylated hydroxytoluene (BHT), synthetic antioxidant, showed higher antioxidant effect on soybean biodiesel in relation to additivations with leaves and their extracts after 1176h. In beef tallow biodiesel BHT activity was similar to the extracts of the leaves of cherry, soursop and cherry after 504h and the sleeve after 1176h. The order of stability of soy biodiesel additive against low temperatures was: cherry extract> mango extract> acerola extract> soursop extract. The results of the tests indicate that low temperature soybean biodiesel additive or may not be used in any region of the country for all seasons. The effect of the extracts of leaves in front biodiesel stability at low temperatures was: extracts of mango leaves> acerola extracts> soursop extracts> cherry extracts. Biodiesel pure beef tallow has lower stability in low temperatures to soy biodiesel. The results of the AI, kinematic viscosity, density, FTIR and TGA show that the extracts of the leaves and fruits studied sheets can act as antioxidant additives in the oxidative stability of biodiesel.