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91.
92.
Much evidence demonstrates the antinociceptive effect of magnetic fields (MFs). However, the analgesic action mechanism of the electromagnetic field (EMF) is not exactly understood. The aim of the present study was to investigate the effects of 5‐HT1 and 5‐HT2 receptor agonists (serotonin HCl and 2,5‐dimethoxy‐4‐iodoamphetamine [DOI] hydrochloride) on EMF‐induced analgesia. In total, 66 adult male Wistar albino rats with an average body mass of 225 ± 13 g were used in this study. The animals were subjected to repeated exposures of alternating 50 Hz and 5 mT EMF for 2 h a day for 15 days. Prior to analgesia tests, serotonin HCl (5‐HT1 agonist) 4 mg/kg, WAY 100635 (5‐HT1 antagonist) 0.04 mg/kg, DOI hydrochloride (5‐HT2 receptor agonist) 4 mg/kg, and SB 204741 (5‐HT2 antagonist) 0.5 mg/kg doses were injected into rats. For statistical analysis of the data, analysis of variance was used and multiple comparisons were determined by Tukey’s test. Administration of serotonin HCl MF (5 mT)‐exposed rats produced a significant increase in percent maximal possible effect (% MPE) as compared with EMF group (P < 0.05). On the contrary, injection of WAY 100635 to MF‐exposed rats produced a significant decrease in analgesic activity (P < 0.05). Similarly, the administration of DOI hydrochloride significantly increased % MPE values as compared with the EMF group while SB 204741 reduced it (P < 0.05). In conclusion, our results suggested that serotonin 5‐HT1 and 5‐HT2 receptors play an important role in EMF‐induced analgesia; however, further research studies are necessary to understand the mechanism. Bioelectromagnetics. 2019;40:319–330. © 2019 Bioelectromagnetics Society.  相似文献   
93.
Morningness–eveningness is an individual difference that is related with various traits such as behavioral problems, personality, and health. The aim of the current study is to adopt the Morningness–Eveningness Stability Scale improved (MESSi) which is a novel assessment tool that consists of subscales of morning affect (MA), eveningness (EV), and distinctness (DI) into Turkish. Concurrent validity of the MESSi along with Big five inventory (BIG-5), Subjective alertness level, Pittsburg Sleep Quality Index (PSQI), Positive and Negative Affect Schedule (PANAS) were analyzed. The scale was administered to 1,076 high school and university students aged 14–47 years (M = 19.49, SD = 3.53). The explanatory factor analysis (EFA) and confirmatory factor analysis (CFA) revealed the three-factor structure of MESSi. According to the concurrent validity result of the MESSi with BIG-5, conscientiousness was found to correlate positively with MA and negatively with EV. Also, extraversion showed a negative correlation with DI and positive correlation with MA. Furthermore, the subjective alertness rating results showed that MA was positively related to alertness in the morning hours and negatively in the evening hours. Also, sleep quality-related results showed that EV and DI are positively related to total PSQI scores and negatively related to MA. In addition, concerning positive affect (PA) and negative affect (NA), MA was positively related with PA and negatively with NA, while DI was negatively related with PA and positively with NA. In overall, MESSi is a valid and reliable instrument and can be used in Turkish students.  相似文献   
94.
The aim of this work was to investigate the enzyme inhibition, antioxidant activity, and phenolic compounds of Lecokia cretica (Lam .) DC. Acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α‐glycosidase enzymes were strongly inhibited by the L. cretica extracts. IC50 values for the three enzymes were found as 3.21 mg/mL, 2.1 mg/mL, and 2.07 mg/mL, respectively. Antioxidant activities were examined in both aqueous and ethanol (EtOH) extracts using CUPRAC, FRAP, and DPPH method. Also, the phenolic compounds of the endemic plant were identified and quantified by using HPLC/MS/MS. According to the results, the extracts have remarkable antioxidant activities. The most abundant phenolic acids of L. cretica in EtOH extract were determined as quinic acid (12.76 mg/kg of crude extract), chlorogenic acid (3.39 mg/kg), and malic acid (2.38 mg/kg).  相似文献   
95.
The main objectives of this study were to optimize β-mannanase fermentation conditions by using Response Surface Methodology (RSM) and to model kinetically using the kinetic models. Based on the results, the optimum fermentation conditions were found to be initial sugar concentration of 10°Bx, whey concentration of 0.75% [w/v], and inoculum size of 8% (v/v). Under optimized conditions, β-mannanase activity (P), sugar consumed (ΔS), maximum β-mannanase production rate (QP), and sugar utilization yield (SUY) were 687.89 U/mL, 47.38 g/L, 118.54 U mL–1 day–1, and 69.73%, respectively. Kinetic models were employed to describe the optimum β-mannanase fermentation process. The kinetic analysis of β-mannanase fermentation showed that β-mannanase fermentation is growth associated because the α value (U/mgX) is approximately 330-fold higher than the β value (U/mgX·hr). Nevertheless, maintenance value (Z) was lower than γ value, thus showing that Aspergillus niger mainly utilizes the sugars for β-mannanase production and fungal growth. Consequently, carob extract and whey powder could be used to be cost-effective carbon and organic nitrogen sources, respectively. It was clearly indicated that the suggested kinetic models can successfully describe the fungal growth, β-mannanase production, and substrate consumption.  相似文献   
96.
Xiao Y  Tan ML  Ichiye T  Wang H  Guo Y  Smith MC  Meyer J  Sturhahn W  Alp EE  Zhao J  Yoda Y  Cramer SP 《Biochemistry》2008,47(25):6612-6627
We have used (57)Fe nuclear resonance vibrational spectroscopy (NRVS) to study the Fe(2)S(2)(Cys)(4) sites in oxidized and reduced [2Fe-2S] ferredoxins from Rhodobacter capsulatus (Rc FdVI) and Aquifex aeolicus (Aa Fd5). In the oxidized forms, nearly identical NRVS patterns are observed, with strong bands from Fe-S stretching modes peaking around 335 cm(-1), and additional features observed as high as the B(2u) mode at approximately 421 cm(-1). Both forms of Rc FdVI have also been investigated by resonance Raman (RR) spectroscopy. There is good correspondence between NRVS and Raman frequencies, but because of different selection rules, intensities vary dramatically between the two kinds of spectra. For example, the B(3u) mode at approximately 288 cm(-1), attributed to an asymmetric combination of the two FeS(4) breathing modes, is often the strongest resonance Raman feature. In contrast, it is nearly invisible in the NRVS, as there is almost no Fe motion in such FeS(4) breathing. NRVS and RR analysis of isotope shifts with (36)S-substituted into bridging S(2-) ions in Rc FdVI allowed quantitation of S(2-) motion in different normal modes. We observed the symmetric Fe-Fe stretching mode at approximately 190 cm(-1) in both NRVS and RR spectra. At still lower energies, the NRVS presents a complex envelope of bending, torsion, and protein modes, with a maximum at 78 cm(-1). The (57)Fe partial vibrational densities of states (PVDOS) were interpreted by normal-mode analysis with optimization of Urey-Bradley force fields. Progressively more complex D(2h) Fe(2)S(2)S'(4), C(2h) Fe(2)S(2)(SCC)(4), and C(1) Fe(2)S(2)(Cys)(4) models were optimized by comparison with the experimental spectra. After modification of the CHARMM22 all-atom force field by the addition of refined Fe-S force constants, a simulation employing the complete protein structure was used to reproduce the PVDOS, with better results in the low frequency protein mode region. This process was then repeated for analysis of data on the reduced FdVI. Finally, the degree of collectivity was used to quantitate the delocalization of the dynamic properties of the redox-active Fe site. The NRVS technique demonstrates great promise for the observation and quantitative interpretation of the dynamical properties of Fe-S proteins.  相似文献   
97.
Various mechanisms have been proposed for the pathogenesis of postischemic hepatic injury, including the generation of reactive oxygen metabolites. Oxytocin (OT) possesses antisecretory, antiulcer effects, facilitates wound healing and has anti-inflammatory properties. Hepatic ischemia-reperfusion (I/R)-injury was induced by inflow occlusion to median and left liver lobes ( approximately 70%) for 30 min of ischemia followed by 1h reperfusion in female Sprague-Dawley rats under anesthesia. I/R group (n=8) was administered intraperitoneally either OT (500 microg/kg) or saline at 24 and 12 h before I/R and immediately before reperfusion. Sham-operated group that underwent laparotomy without hepatic ischemia served as the control. Rats were decapitated at the end of reperfusion period. Hepatic samples were obtained for the measurement of myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH) and collagen levels and histopathological analysis. Tumor necrosis factor-alfa (TNF-alpha) and transaminases (SGOT, SGPT) were assayed in serum samples. I/R injury caused significant increases in hepatic microscopic damage scores, MPO activity, collagen levels, transaminase, serum TNF-alpha levels. Oxytocin treatment significantly reversed the I/R-induced elevations in serum transaminase and TNF-alpha levels and in hepatic MPO and collagen levels, and reduced the hepatic damage scores. OT treatment had tendency to abolish I/R-induced increase in MDA levels, while GSH levels were not altered. These results suggest that OT has a protective role in hepatic I/R injury and its protective effect in the liver appears to be dependent on its inhibitory effect on neutrophil infiltration.  相似文献   
98.
Carbonic anhydrase (CA) enzymes have been shown to play an important role in ion transport and in pH regulation in several organisms. Despite this information and the wealth of knowledge regarding the significance of CA enzymes, few studies have been reported about bee CA enzymes and the hazardous effects of chemicals. Using Apis mellifera as a model, this study aimed to determine the risk of pesticides on Apis mellifera Carbonic anhydrase enzyme (Am CA). CA was initially purified from Apis mellifera spermatheca for the first time in the literature. The enzyme was purified with an overall purification of ~35-fold with a molecular weight of ~32?kDa. The enzyme was then exposed to pesticides, including tebuconazole, propoxur, carbaryl, carbofuran, simazine and atrazine. The six pesticides dose-dependently inhibited in vitro AmCA activity at low micromolar concentrations. IC50 values for the pesticides were 0.0030, 0.0321, 0.0031, 0.0087, 0.0273 and 0.0165?μM, respectively. The AmCA inhibition mechanism of these compounds is unknown at this moment.  相似文献   
99.
Simple, high-yield purification of xanthine oxidase from bovine milk.   总被引:1,自引:0,他引:1  
Xanthine oxidase, a commercially important enzyme with a wide area of application, was extracted from fresh milk, without added preservatives, using toluene and heat. The short purification procedure, with high yield, consisted of extraction, ammonium sulfate fractionation, and DEAE-Sepharose (fast flow) column chromatography. Xanthine oxidase was eluted as a single activity peak from the column using a buffer gradient. The purification fold, specific activity and yield for the purified xanthine oxidase were 328, 10.161 U/mg and 69%, respectively. The enzyme was concentrated by ultrafiltration, although 31% of the activity was lost during concentration, no change in specific activity was observed. Activity and protein gave coincident staining bands on native polyacrylamide gels. The intensity and the number of bands were dependent on the oxidative state(s) of the enzyme; reduction by 2-mercaptoethanol decreased the intensity of the slow-moving bands and increased the intensity of the fastest-moving band. Following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two major bands (molecular masses of 152 and 131 kDa) were observed, accounting for > or = 95% of xanthine oxidase. Native- and SDS-PAGE showed that the purified xanthine oxidase becomes a heterodimer due to endogenous proteases.  相似文献   
100.
The effect of iloprost on airway smooth muscles and its influence on the actions of beta-agonists and histamine were studied in the isolated perfused lung and isolated tracheal strips from guinea-pigs. Bolus injection of iloprost into the pulmonary artery elicited a concentration-dependent decrease in pulmonary perfusion pressure and an increase in airway resistance. These effects are not mediated through cholinergic, serotoninergic and histaminergic receptors. A rapid tachyphylaxis affected the effect of iloprost in airway resistance but not in pulmonary perfusion pressure. Iloprost did not induce a response in the isolated tracheal strips and did not alter the effect of histamine in both tracheal strips and airway resistance. This compound, however, caused an inhibition in the airway resistance-reducing effect of adrenaline and isoprenaline in the isolated perfused lung and a potentiation in the perfusion pressure-increasing effect of adrenaline. Iloprost also inhibited the relaxing effect of adrenaline and isoprenaline in the isolated tracheal strips precontracted with histamine and potentiated the inhibitory effect of propranolol against adrenaline and isoprenaline. From these results it was concluded that: Iloprost, a stable analogue of prostacyclin, modulates the beta-adrenoceptor blocking effect of propranolol in both airway smooth muscles and pulmonary vasculature.  相似文献   
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