13 resultados para 481

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The filamentous fungus Paecylomices variotii was able to produce high levels of cell extract and extracellular invertases when grown under submerged fermentation (SbmF) and solid-state fermentation, using agroindustrial products or residues as substrates, mainly soy bran and wheat bran, at 40A degrees C for 72 h and 96 h, respectively. Addition of glucose or fructose (a parts per thousand yen1%; w/v) in SbmF inhibited enzyme production, while the addition of 1% (w/v) peptone as organic nitrogen source enhanced the production by 3.7-fold. However, 1% (w/v) (NH4)(2)HPO4 inhibited enzyme production around 80%. The extracellular form was purified until electrophoretic homogeneity (10.5-fold with 33% recovery) by DEAE-Fractogel and Sephacryl S-200 chromatography. The enzyme is a monomer with molecular mass of 102 kDa estimated by SDS-PAGE with carbohydrate content of 53.6%. Optima of temperature and pH for both, extracellular and cell extract invertases, were 60A degrees C and 4.0-4.5, respectively. Both invertases were stable for 1 h at 60A degrees C with half-lives of 10 min at 70A degrees C. Mg2+, Ba2+ and Mn2+ activated both extracellular and cell extract invertases from P. variotii. The kinetic parameters K-m and V-max for the purified extracellular enzyme corresponded to 2.5 mM and 481 U/mg prot(-1), respectively.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper we study the continuity of invariant sets for nonautonomous infinite-dimensional dynamical systems under singular perturbations. We extend the existing results on lower-semicontinuity of attractors of autonomous and nonautonomous dynamical systems. This is accomplished through a detailed analysis of the structure of the invariant sets and its behavior under perturbation. We prove that a bounded hyperbolic global solutions persists under singular perturbations and that their nonlinear unstable manifold behave continuously. To accomplish this, we need to establish results on roughness of exponential dichotomies under these singular perturbations. Our results imply that, if the limiting pullback attractor of a nonautonomous dynamical system is the closure of a countable union of unstable manifolds of global bounded hyperbolic solutions, then it behaves continuously (upper and lower) under singular perturbations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: To investigate the effect of lovastatin on renal ischemia followed by reperfusion. METHODS: Thirty one Wistar rats submitted to left renal ischemia for 60 minutes followed by contralateral nephrectomy were divided into two groups: A (n = 17, control, no treatment), and B (n = 14, lovastatin 15 mg/kg/day p.o. ten days before ischemia). The animals were sacrificed at the end of ischemia, after 24 hours and at seven days after reperfusion. Survival, serum urea and creatinine levels and renal mitochondrial function were evaluated. RESULTS: Mortality was 29.4% in group A and 0.7% in group B. Urea and creatinine levels were increased in both groups, but the values were significantly lower in group B. Mitochondrial function showed decoupling in 83.4% of group A, as opposed to 38.4/% of group B. CONCLUSIONS: The result shows a protective action of renal function by lovastatin administered before ischemia/reperfusion. Since most of the mitochondrial fraction presented membranes with the ability to maintain ATP production in group B, stabilization of the mitochondrial membrane should be considered as part of the protective action of lovastatin on renal function in ischemia/reperfusion.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Amniotic fluid (AF) was described as a potential source of mesenchymal stem cells (MSCs) for biomedicine purposes. Therefore, evaluation of alternative cryoprotectants and freezing protocols capable to maintain the viability and stemness of these cells after cooling is still needed. AF stem cells (AFSCs) were tested for different freezing methods and cryoprotectants. Cell viability, gene expression, surface markers, and plasticity were evaluated after thawing. AFSCs expressed undifferentiated genes Oct4 and Nanog; presented typical markers (CD29, CD44, CD90, and CD105) and were able to differentiate into mesenchymal lineages. All tested cryoprotectants preserved the features of AFSCs however, variations in cell viability were observed. In this concern, dimethyl sulfoxide (Me2SO) showed the best results. The freezing protocols tested did not promote significant changes in the AFSCs viability. Time programmed and nonprogrammed freezing methods could be used for successful AFSCs cryopreservation for 6 months. Although tested cryoprotectants maintained undifferentiated gene expression, typical markers, and plasticity of AFSCs, only Me2SO and glycerol presented workable viability ratios.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction: The purpose of this randomized clinical study was to evaluate the presence of the periodontal pathogen Aggregatibacter actinomycetemcomitans on metallic brackets and the effectiveness of a 0.12% chlorhexidine digluconate mouthwash in inhibiting this microorganism. Methods: The study involved 35 patients of both sexes having orthodontic treatment with fixed appliances between the ages of 14 and 22 years, randomized into 2 groups: experimental (n = 17) and control (n = 18). Two new metallic brackets were placed on the patients' premolars, and the subjects rinsed with a solution of 0.12% chlorhexidine digluconate or a placebo solution twice a week for 30 days. After that, the brackets were removed and underwent microbiologic analysis with the checkerboard DNA-DNA hybridization technique. Data were analyzed by using the Student t, Fisher exact, and Mann-Whitney tests at the significance level of 5%. Results: The results showed that A actinomycetemcomitans was present in all brackets from the subjects in the control group vs 83% of the subjects who rinsed with chlorhexidine digluconate (P<0.0001). There were also significantly lower levels of this species in the chlorhexidine digluconate group compared with the control group (P = 0.0003). Conclusions: We concluded that 0.12% chlorhexidine digluconate rinsing, twice a week for 30 days during orthodontic treatment, is effective in reducing the presence and levels of A actinomycetemcomitans on metallic brackets. (Am J Orthod Dentofacial Orthop 2012;142:481-6)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: To assess reproductive function in male ankylosing spondylitis (AS) patients in comparison to healthy controls. Methods: Twenty AS patients were compared to 24 healthy male subjects with regard to demographic data, urological examination, testicular ultrasound (US), semen analysis, anti-sperm antibodies, and hormone profile. Exclusion criteria were present use of sulfasalazine or methotrexate, and ever use of biological/cytotoxic agents. Disease activity of AS was evaluated by clinical and laboratory assessments. Results: Demographic data were similar in AS and controls (p = 0.175). Varicocele was found significantly more frequently in AS patients than in controls (40% vs. 8%, p = 0.027). Semen analysis revealed no significant differences in sperm quality between AS patients and controls (p > 0.05). By contrast, the median of normal sperm forms was significantly lower in AS patients with vs. those without varicocele [13.5 (range 2-27) vs. 22 (range 10-32.5)%, p = 0.049] whereas no difference in sperm morphology was observed comparing AS patients and controls without varicocele (p = 0.670). Comparison of AS patients with and without varicocele showed that anti-sperm antibodies, hormones, inflammatory markers, and disease activity scores did not contribute to the impaired sperm morphology observed in AS patients with varicocele. Conclusions: An increased frequency of varicocele was found in AS patients associated with sperm abnormalities but independent of therapy, anti-sperm antibodies, hormonal alterations, or disease parameters. Investigation for varicocele should be routine in AS patients with fertility problems.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ferreira-Junior NC, Fedoce AG, Alves FHF, Correa FMA, Resstel LBM. Medial prefrontal cortex endocannabinoid system modulates baroreflex activity through CB1 receptors. Am J Physiol Regul Integr Comp Physiol 302: R876-R885, 2012. First published December 28, 2011; doi: 10.1152/ajpregu.00330.2011.-Neural reflex mechanisms, such as the baroreflex, are involved in the regulation of cardiovascular system activity. Previous results from our group (Resstel LB, Correa FM. Medial prefrontal cortex NMDA receptors and nitric oxide modulate the parasympathetic component of the baroreflex. Eur J Neurosci 23: 481-488, 2006) have shown that glutamatergic synapses in the ventral portion of the medial prefrontal cortex (vMPFC) modulate baroreflex activity. Moreover, glutamatergic neurotransmission in the vMPFC can be modulated by the endocannabinoids system (eCBs), particularly the endocannabinoid anandamide, through presynaptic CB1 receptor activation. Therefore, in the present study, we investigated eCBs receptors that are present in the vMPFC, and more specifically whether CB1 receptors modulate baroreflex activity. We found that bilateral microinjection of the CB1 receptor antagonist AM251 (100 or 300 pmol/200 nl) into the vMPFC increased baroreflex activity in unanesthetized rats. Moreover, bilateral microinjection of either the anandamide transporter inhibitor AM404 (100 pmol/200 nl) or the inhibitor of the enzyme fatty acid amide hydrolase that degrades anandamide, URB597 (100 pmol/200 nl), into the MPFC decreased baroreflex activity. Finally, pretreatment of the vMPFC with an ineffective dose of AM251 (10 pmol/200 nl) was able to block baroreflex effects of both AM404 and URB597. Taken together, our results support the view that the eCBs in the vMPFC is involved in the modulation of baroreflex activity through the activation of CB1 receptors, which modulate local glutamate release.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: To analyze the efficiency of high voltage pulsed current (HVPC) with early application in three different sites, in the regeneration of the sciatic nerve in rats submitted to crush injury, the sciatic functional index (SFI) was used to assess the functional recovery. Methods: After crushing of the nerve, 57 animals were submitted to cathodal HVPC at frequency of 50Hz and voltage of 100V, 20 minutes per day, 5 days per week. The rats were divided into five groups: control group; ganglion group; ganglion + muscle group; muscle group; and sham group. The SFI was determined weekly for seven weeks, from the preoperative period to the 6th postoperative week. Results: Compared with the control group, the results showed a significantly better performance of group 2 for the first 3 weeks; group 3 showed significantly better performance in the third week; and group 4 showed a significantly negative performance during the 481 and 6th weeks. Conclusion: Early application of HVPC had a positive effect in the treatment of the spinal cord region and the sciatic nerve root ganglion with a dispersive electrode on the contralateral lumbar region or on the gastrocnemius. However, HVPC had a negative effect in the treatment with an active electrode on the gastrocnemius and a dispersive electrode on the contralateral thigh. Level of evidence II, Prospective comparative study.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: The purpose of this study was to determine the impact of pharmacologic treatment with cilostazol and pentoxifylline on gait biomechanics of ischemic rat hindlimbs compared with nonischemic controls. Methods: An experimental study was designed using 30 Wistar rats divided into five groups (n = 6): control (C); ischemia (I) - animals submitted to left common iliac artery interruption without pharmacologic treatment; pentoxifylline (Pen) - rats submitted to procedure and treated with pentoxifylline 3 mg/kg twice a day for 6 weeks; cilostazol (Cil) - animals submitted to procedure and treated with cilostazol 30 mg/kg twice a day for 6 weeks; and sham (S) - animals submitted to procedure without artery interruption. Gait analysis was performed using a computed treadmill. Time, number, and duration of each hindlimb contact were obtained. The total number of contacts (TNC) and the total duration of contacts (TDC) were compared between left and right hindlimb and among groups. Left hindlimb ischemic incapacitation index (LHII) was defined by the formula: LHII = (1 - TNCleft x TDCleft/TNCright x TDCright) x 100 Results: Left hindlimb TNC values were twofold lower in I, Pen, and Cil groups than in C and S groups (P < .01). In I, Pen, and Cil groups, TNC values for the left hindlimb were half of the right hindlimb ones (P < .01). Left hindlimb TDC values were lower in I and Pen groups than the other groups (P < .01). Cil group presented twofold increased values, not different from C and S groups (P = 0.16). Right hindlimb TNC values were greater for I group (P < .01). LHII was around zero in C and S groups and 82 in both I and Pen groups (P < .01). Cil group presented a LHII of 42; higher than C and S groups, but lower than I and Pen groups (P < .01). Conclusions: Cilostazol at a dose of 30 mg/kg twice a day promoted improvement in gait performance in rats submitted to chronic hindlimb ischemia. Pentoxifylline at a dose of 3 mg/kg twice a day did not show this effect. (J Vasc Surg 2012;56:476-81.)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Copaifera langsdorffii Desf. commonly known as "copaiba", produce a commercially valuable oil-resin that is extensively used in folk medicine for anti-inflammatory, antimicrobial and antiseptic purposes. We have found the hydroalcoholic extract of this plant leaf has the potential to treat urolithiasis, a problem affecting similar to 7% of the population. To isolate the functional compounds C. langsdorffii leaves were dried, ground, and macerated in a hydroalcoholic solution 7:3 to produce a 16.8% crude extract after solvent elimination. Urolithiasis was induced by introduction of a calcium oxalate pellet (CaOx) into the bladders of adult male Wistar rats. The treated groups received the crude extract by oral gavage at 20 mg/kg body weight daily for 18 days. Extract treatment started 30 days after CaOx seed implantation. To monitor renal function sodium, potassium and creatinine concentrations were analyzed in urine and plasma, and were found to be in the normal range. Analyses of pH, magnesium, phosphate, calcium, uric acid, oxalate and citrate levels were evaluated to determine whether the C. langsdorffii extract may function as a stone formation prevention agent. The HPLC analysis of the extract identified flavonoids quercitrin and afzelin as the major components. Animals treated with C. langsdorffii have increased levels of magnesium and decreased levels of uric acid in urinary excretions. Treated animals have a significant decrease in the mean number of calculi and a reduction in calculi mass. Calculi taken from extract treated animals were more brittle and fragile than calculi from untreated animals. Moreover, breaking calculi from untreated animals required twice the amount of pressure as calculi from treated animals (6.90 +/- A 3.45 vs. 3.00 +/- A 1.51). The extract is rich in flavonoid heterosides and other phenolic compounds. Therefore, we hypothesize this class of compounds might contribute significantly to the observed activity.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O objetivo específico deste artigo é identificar as origens dos empresários, como nacionalidade e gênese do capital para o início da atividade, na indústria de máquinas e equipamentos em São Paulo, e a evolução do setor no período de 1870 a 1900. Tentamos identificar os empreendimentos na indústria e sua relação com o comércio importador e exportador, com os fazendeiros de produtos para exportação (principalmente o café), com os imigrantes comerciantes e com os que possuíam algum conhecimento técnico.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ensaios de migração de cloretos são usados para mensurar a capacidade do concreto em inibir o ataque por cloretos. Muitos pesquisadores realizam esse ensaio em uma fatia de concreto extraída da parte central dos corpos de prova cilíndricos, descartando cerca de 75% do concreto usado para moldar os corpos de prova. Esse fato gerou a questão: Seria possível extrair mais fatias de um mesmo corpo de prova sem se perder a confiança nos resultados? O principal objetivo desse trabalho é responder a essa pergunta. Outro objetivo desse estudo foi mostrar a diferença da penetração de cloretos entre as faces finais e as superfícies internas das vigas e lajes de concreto. Os resultados indicaram que é possível usar mais fatias de um único corpo de prova para um teste de migração de cloretos. Além disso, foi demonstrado que houve significativa diferença da penetração de cloretos entre as superfícies acabadas (com desempenadeira - topo do corpo de prova) e as superfícies provenientes das paredes das fôrmas (base do corpo de prova).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O implante coclear (IC) tem sido indicado para crianças deficientes auditivas de grau severo e/ou profundo que não tem benefício com o aparelho de amplificação sonora individual (AASI), e que apresentem família adequada e motivada para o uso do dispositivo, bem como condições adequadas de reabilitação na cidade de origem. Atualmente, a procura pelo IC também ocorre por pais surdos, fluentes na Língua Brasileira de Sinais (LIBRAS), que recorrem a este tratamento para oferecer outra realidade para seus filhos. O ambiente destas crianças é bilíngue, dado pela LIBRAS dos pais e pela linguagem oral dos familiares próximos, do fonoaudiólogo e da escola. Neste sentido, o presente estudo visou acompanhar quatro crianças deficientes auditivas implantadas, sendo duas crianças filhas de pais deficientes auditivos fluentes na LIBRAS (expostas a ambiente bilíngue) e duas crianças filhas de pais sem alterações auditivas (expostas a ambiente oral). Para tanto, as habilidades de audição e de aquisição da linguagem oral foram comparadas nas quatro crianças implantadas. Foi possível observar que as quatro crianças apresentaram habilidades auditivas e de linguagem semelhantes ao longo do primeiro ano de uso do IC. Contudo, a partir disto, as crianças inseridas em ambiente bilíngue apresentaram melhor desempenho auditivo e linguístico, comparado ao desenvolvimento das outras crianças. As crianças inseridas em ambiente bilíngue podem se beneficiar do IC, desenvolvendo habilidades auditivas e de linguagem similares às das crianças inseridas em ambiente oral. Ressalta-se que os benefícios do dispositivo são obtidos a partir de aspectos multifatoriais, e estudos mais aprofundados são necessários.