排序方式: 共有119条查询结果,搜索用时 15 毫秒
51.
Luciana E. Drumond Talita H. Ferreira‐Vieira Danielle Bernardes Josiane F. Silva Virgínia S. Lemos Márcio F. D. Moraes Grace S. Pereira Juliana Carvalho‐Tavares André R. Massensini 《Journal of neurochemistry》2012,123(2):317-324
Although it is well known that regular exercise may promote neuroprotection, the mechanisms underlying this effect are still not fully understood. We investigated if swim training promotes neuroprotection by potentiating antioxidant pathways, thereby decreasing the effects of oxidative stress on glutamate and nitric oxide release. Male Wistar rats (n=36) were evenly randomized into a trained group (TRA) (5 days/week, 8 weeks, 30 min) and a sedentary group (SED). Forty‐eight hours after the last session of exercise, animals were killed and brain was collected for in vitro ischemia. Cortical slices were divided into two groups: a group in which oxidative stress was induced by oxygen and glucose deprivation (OGD), and a group of non‐deprived controls (nOGD). Interestingly, exercise by itself increased superoxide dismutase activity (nOGD, SED vs. TRA animals) with no effect on pro‐oxidative markers. In fact, TRA‐OGD slices showed lowered levels of lactate dehydrogenase when compared with SED‐OGD controls, reinforcing the idea that exercise affords a neuroprotective effect. We also demonstrated that exercise decreased glutamate and nitrite release as well as lipid membrane damage in the OGD cortical slices. Our data suggest that under conditions of metabolic stress, swim training prevents oxidative damage caused by glutamate and nitric oxide release. 相似文献
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Scaini G de Rochi N Jeremias IC Deroza PF Zugno AI Pereira TC Oliveira GM Kist LW Bogo MR Schuck PF Ferreira GC Streck EL 《Molecular neurobiology》2012,45(2):279-286
Maple syrup urine disease is an inherited metabolic disease predominantly characterized by neurological dysfunction. However, the mechanisms underlying the neuropathology of this disease are still not defined. Therefore, the aim of this study was to investigate the effect of acute and chronic administration of a branched-chain amino acids (BCAA) pool (leucine, isoleucine, and valine) on acetylcholinesterase (AChE) activity and gene expression in the brain and serum of rats and to assess if antioxidant treatment prevented the alterations induced by BCAA administration. Our results show that the acute administration of a BCAA pool in 10- and 30-day-old rats increases AChE activity in the cerebral cortex, striatum, hippocampus, and serum. Moreover, chronic administration of the BCAA pool also increases AChE activity in the structures studied, and antioxidant treatment prevents this increase. In addition, we show a significant decrease in the mRNA expression of AChE in the hippocampus following acute administration in 10- and 30-day-old rats. On the other hand, AChE expression increased significantly after chronic administration of the BCAA pool. Interestingly, the antioxidant treatment was able to prevent the increased AChE activity without altering AChE expression. In conclusion, the results from the present study demonstrate a marked increase in AChE activity in all brain structures following the administration of a BCAA pool. Moreover, the increased AChE activity is prevented by the coadministration of N-acetylcysteine and deferoxamine as antioxidants. 相似文献
53.
Luis C. A. da Silva Talita L. Honorato Rosane S. Cavalcante Telma T. Franco Sueli Rodrigues 《Indian journal of microbiology》2012,52(1):60-65
Trichoderma strains were extensively studied as biocontrol agents due to their ability of producing hydrolytic enzymes, which are considered
key enzymes because they attack the insect exoskeleton allowing the fungi infection. The present work aimed to evaluate the
ability of chitosanase production by four Trichoderma strains (T. harzianum, T. koningii, T. viride and T. polysporum) under solid stated fermentation and to evaluate the effect of pH and temperature on enzyme activity. pH strongly affected
the enzyme activity from all tested strains. Chitosanase from T. harzianum and T. viride presented optimum activity at pH 5.0 and chitosanase from T. koningii and T. polysporum presented optimum activity at pH 5.5. Temperature in the range of 40–50°C did not affect enzyme activity. T. polysporum was found as the most promising strain to produce chitosanase with maximal enzyme activity of about 1.4 IU/gds, followed
by T. viride (~1.2 IU/gds) and T. harzianum (1.06 IU/gds). 相似文献
54.
Souza AC Volpini RA Shimizu MH Sanches TR Camara NO Semedo P Rodrigues CE Seguro AC Andrade L 《American journal of physiology. Renal physiology》2012,302(8):F1045-F1054
The pathophysiology of sepsis involves complex cytokine and inflammatory mediator networks, a mechanism to which NF-κB activation is central. Downregulation of endothelial nitric oxide synthase (eNOS) contributes to sepsis-induced endothelial dysfunction. Erythropoietin (EPO) has emerged as a major tissue-protective cytokine in the setting of stress. We investigated the role of EPO in sepsis-related acute kidney injury using a cecal ligation and puncture (CLP) model. Wistar rats were divided into three primary groups: control (sham-operated); CLP; and CLP+EPO. EPO (4,000 IU/kg body wt ip) was administered 24 and 1 h before CLP. Another group of rats received N-nitro-l-arginine methyl ester (l-NAME) simultaneously with EPO administration (CLP+EPO+l-NAME). A fifth group (CLP+EPOtreat) received EPO at 1 and 4 h after CLP. At 48 h postprocedure, CLP+EPO rats presented significantly higher inulin clearance than did CLP and CLP+EPO+l-NAME rats; hematocrit levels, mean arterial pressure, and metabolic balance remained unchanged in the CLP+EPO rats; and inulin clearance was significantly higher in CLP+EPOtreat rats than in CLP rats. At 48 h after CLP, creatinine clearance was significantly higher in the CLP+EPO rats than in the CLP rats. In renal tissue, pre-CLP EPO administration prevented the sepsis-induced increase in macrophage infiltration, as well as preserving eNOS expression, EPO receptor (EpoR) expression, IKK-α activation, NF-κB activation, and inflammatory cytokine levels, thereby increasing survival. We conclude that this protection, which appears to be dependent on EpoR activation and on eNOS expression, is attributable, in part, to inhibition of the inflammatory response via NF-κB downregulation. 相似文献
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56.
Santoro PH Neves PM Alexandre TM Sartori D Alves LF Fungaro MH 《Journal of invertebrate pathology》2008,97(2):83-90
This paper presents results on isolates of the entomopathogenic fungus Beauveria bassiana for Alphitobius diaperinus (Coleoptera: Tenebrionidae) control. Of the 30 isolates tested, four (CG 71, CG 152, UNIOESTE 4, and UNIOESTE 40) resulted in mortality rates >or= 40% within 10 days. These mortality rates could be considered high because of the resistance of these species to B. bassiana. Tests were conducted using these isolates to estimate LC(50), mortality rate over time, vegetative growth, and conidial production on artificial medium and on insects. Isolates CG 71, CG 152, and UNIOESTE 4 showed the best performance and great potential to be used in an integrated management program in poultry farms to control A. diaperinus. Also, the molecular profiles of 12 isolates were analyzed using the RAPD technique. The high-virulence isolates presented a more homogeneous RAPD pattern than the others. Genetic sequencing of the ITS region was performed for one of the virulent isolates (UNIOESTE 4) and compared with sequences deposited at the NCBI database, confirming its taxonomical position as belonging to B. bassiana Clade A. 相似文献
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Talita B. Gontijo Rossimiriam P. de Freitas Flavio S. Emery Leandro F. Pedrosa José B. Vieira Neto Bruno C. Cavalcanti Claudia Pessoa Aaron King Fabio de Moliner Marc Vendrell Eufrânio N. da Silva Júnior 《Bioorganic & medicinal chemistry letters》2017,27(18):4446-4456
Fluorescent quinone-based BODIPY hybrids were synthesised and characterised by NMR analysis and mass spectrometry. We measured their cytotoxic activity against cancer and normal cell lines, performed mechanistic studies by lipid peroxidation and determination of reduced (GSH) and oxidized (GSSG) glutathione, and imaged their subcellular localisation by confocal microscopy. Cell imaging experiments indicated that nor-β-lapachone-based BODIPY derivatives might preferentially localise in the lysosomes of cancer cells. These results assert the potential of hybrid quinone-BODIPY derivatives as promising prototypes in the search of new potent lapachone antitumor drugs. 相似文献
59.
Chagas CM Honorato TL Pinto GA Maia GA Rodrigues S 《Bioprocess and biosystems engineering》2007,30(3):207-215
Cashew apples are considered agriculture excess in the Brazilian Northeast because cashew trees are cultivated primarily with
the aim of cashew nut production. In this work, the use of cashew apple juice as a substrate for Leuconostoc mesenteroides cultivation was investigated. The effect of yeast extract and phosphate addition was evaluated using factorial planning tools.
Both phosphate and yeast extract addition were significant factors for biomass growth, but had no significant effect on maximum
enzyme activity. The enzyme activities found in cashew apple juice assays were at least 3.5 times higher than the activity
found in the synthetic medium. Assays with pH control (pH = 6.5) were also carried out. The pH-controlled fermentation enhanced
biomass growth, but decreased the enzyme activity. Crude enzyme free of cells produced using cashew apple juice was stable
for 16 h at 30°C at a pH of 5.0. 相似文献
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