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51.
Glucose-6-phosphate dehydrogenase (G6PD) plays important roles in the maintenance of cellular redox balance. It was not until recently that the importance of G6PD in regulation of cellular growth and apoptosis emerged. In the present study, we found that G6PD-deficient fibroblasts were more susceptible to peroxynitrite-induced cytotoxicity. Treatment with peroxynitrite generator 3-morpholinosydnonimine (SIN-1) hydrochloride caused apoptosis in human fibroblast in a dose-dependent manner. This was preceded by a decrease in the intracellular level of glutathione (GSH) as well as accumulation of p53. The extent of apoptosis and glutathione depletion were greater in G6PD-deficient fibroblasts than in the normal counterpart. Pretreatment with green tea polyphenol epigallocatechin-3-gallate (EGCG) effectively blocked peroxynitrite-induced glutathione depletion, p53 accumulation, and apoptosis in both normal and G6PD-deficient cells. EGCG, administered to cells alone or as pretreatment, caused activation of Akt. The protective effect was abolished by phosphatidylinositol 3-kinase (PI3K) inhibitors, wortmannin, and LY294002. Our findings suggest that G6PD deficiency enhances the toxicity of peroxynitrite and that EGCG initiates cell survival signaling via the PI3K/akt pathway. 相似文献
52.
Nobuaki Kimura Wen-Cheng Liu Chih-Yu Chiu T. K. Kratz Wei-Bo Chen 《Paddy and Water Environment》2012,10(1):17-30
A nowcasting system integrating observations and a numerical model was developed to better understand the spatial distributions
and temporal variations in the dynamics of a small, subtropical lake occasionally influenced by severe rainstorms. The nowcasting
system was used to monitor real-time meteorological conditions and thermal structures, to provide spatial information on the
thermal and flow dynamics from model predictions, and to compare the predictions with the observations. The system was also
able to determine whether the instruments collecting field data were performing correctly using telemetry operations. The
nowcasting system was initially operated in the spring of 2009 in Yuan-Yang Lake, Taiwan. Rainstorm-induced mixing occurred
due to Typhoon Morakot during August 7–9, 2009. The mixing was observed by the instruments, and the spatial distributions
and temporal variations during the mixing were successfully predicted by the three-dimensional hydrodynamic lake model. A
quantitative comparison of the energy balances among the heat, wind, and water inflow inputs to the lake implied that the
typhoon-induced mixing was primarily caused by strong winds. The model predictions showed that the lake experienced mixing
and flooding (large amounts of inflow/outflow discharges), resulting in homogenous temperatures and flows that moved to the
outlet of the lake. 相似文献
53.
To produce a thermostable and neutral phytase (phy) of Bacillus subtilis E20 in Escherichia coli HMS174 and evaluate its efficiency in improving growth performance. The phy C of B. subtilis E20 was expressed in E. coli HMS 174, and then the 42‐kDa recombinant phy C was purified by Ni‐NAT and analysed by SDS–PAGE. The recombinant phy C had optimal ranges of pH of 6 ~ 7 and temperature of 50 ~ 60 °C. A thermostability analysis showed that the enzyme is a thermostable phytase, and around 33% of residual activity was detected after being incubated at 90 ~ 100 °C for 10 min. The recombinant phy C‐pretreated soybean meal for feed preparation improved white shrimp, Litopenaeus vannamei, growth and feed efficiency. Overall, the neutral and thermostable phy C is suitable for aquafeed, and it is able to improve the nutritional utilization, resulting in enhanced shrimp growth and reduced feed costs. 相似文献
54.
Philip Y. Lam Po Yee Chiu Hoi Yan Leung Na Chen Pou Kuan Leong Kam Ming Ko 《Fitoterapia》2010,81(8):1239-1245
The effect of schisandrin B (Sch B) on long-term ethanol-induced oxidative stress in various rat tissues was investigated. Long-term ethanol treatment increased reactive oxygen metabolites (ROM) level in plasma. The ethanol-induced oxidative stress was assessed by mitochondrial glutathione and α-tocopherol levels, antioxidant enzyme activities, malondialdehyde (mtMDA) production and heat shock protein (Hsp) 25/70 levels. Liver was most susceptible to oxidative stress with a significant increase in mtMDA production. Long-term Sch B treatment enhanced mitochondrial antioxidant status in a tissue non-specific manner. Sch B co-treatment ameliorated the alterations in plasma ROM levels, mtMDA production and Hsp 25/70 expression in rat tissues. 相似文献
55.
56.
The objective of this research was to conduct a human factors engineering analysis of a grafting robot design using computer-aided 3D simulation technology. A prototype tubing-type grafting robot for fruits and vegetables was the subject of a series of case studies. To facilitate the incorporation of human models into the operating environment of the grafting robot, I-DEAS graphic software was applied to establish individual models of the grafting robot in line with Jack ergonomic analysis. Six human models (95th percentile, 50th percentile, and 5th percentile by height for both males and females) were employed to simulate the operating conditions and working postures in a real operating environment. The lower back and upper limb stresses of the operators were analyzed using the lower back analysis (LBA) and rapid upper limb assessment (RULA) functions in Jack. The experimental results showed that if a leg space is introduced under the robot, the operator can sit closer to the robot, which reduces the operator's level of lower back and upper limbs stress. The proper environmental layout for Taiwanese operators for minimum levels of lower back and upper limb stress are to set the grafting operation at 23.2 cm away from the operator at a height of 85 cm and with 45 cm between the rootstock and scion units. 相似文献
57.
Weihsueh A. Chiu Kenny S. Crump 《Journal of Agricultural, Biological & Environmental Statistics》2012,17(1):107-127
We propose a method for introducing dependence in the dose-response modeling of multiple dichotomous endpoints. The method
uses a copula to define a joint multivariate distribution that is consistent with predetermined marginal distributions representing
the individual dose-response functions for each endpoint. Use of copulas allows the marginal dose-response functions for each
dose-endpoint combination to be unrestricted in form. An application of particular relevance to risk assessment is the dose-response
modeling of multiple types of tumors in test animals exposed to a carcinogen, allowing for tumors at different sites in the
same animal to be statistically dependent. In addition, the method can be used to address the possibility that different tissues/organs
are subject to different internal doses and possibly different active moieties. These applications are illustrated with rodent
cancer bioassay data from two example compounds. 相似文献
58.
Immunoadjuvant activities of a recombinant chicken IL-12 in chickens vaccinated with Newcastle disease virus recombinant HN protein 总被引:1,自引:0,他引:1
Su BS Yin HS Chiu HH Hung LH Huang JP Shien JH Lee LH 《Veterinary microbiology》2011,151(3-4):220-228
Recombinant fowlpox virus (rFPV/HN) expressing Newcastle disease virus (NDV) HN gene and rFPV/HN/chIL-12 co-expressing chicken IL-12 (chIL-12) and HN (rHN/chIL-12) genes have been characterized. rHN/chIL-12 or rchIL-12, expressed by our previous construct rFPV/chIL-12, co-administered with rHN was assessed for adjuvant activities of chIL-12. Chickens were vaccinated with various amounts of rHN/chIL-12 mixed with mineral oil (MO), intramuscularly. Levels of hemagglutination-inhibition (HI) antibody production depended on the concentration of the injected rHN or rHN/chIL-12. The lower HI antibody titers were obtained in chicken groups rHN/chIL-12/7-rHN/chIL-12/9, receiving 60ng rHN/8ng chIL-12 with MO, 30ng rHN/4ng chIL-12 with MO or 15ng rHN/2ng chIL-12 with MO, respectively, compared to those in chicken groups rHN/7-rHN/9, receiving rHN with MO alone. However, chickens in group rHN/chIL-12/7 or rHN/chIL-12/8 and rHN with MO alone showed the same effective protection. Chicken group rHN/chIL-12/9 was even more protective than that in group rHN/9. When rchIL-12 was co-injected with 15ng rHN plus MO, chickens produced low levels of HI antibody titers; while higher levels of IFN-γ production and an effective protection rate (83%) were obtained. On the other hand, low levels of IFN-γ production and low protection response (50%) were obtained in chickens injected with rHN with MO alone. Taken together, when the concentration of rHN decreased to certain levels, rchIL-12 reduced HI antibody production. The increase in the induction of IFN-γ production might suggest the enhancement of the cell-mediated immunity which conferred the protection from the NDV challenge. 相似文献
59.
Kuo MY Ou HC Lee WJ Kuo WW Hwang LL Song TY Huang CY Chiu TH Tsai KL Tsai CS Sheu WH 《Journal of agricultural and food chemistry》2011,59(9):5100-5108
Previous studies have shown that vascular endothelium-derived matrix metalloproteinases (MMPs) contribute to the destabilization of atherosclerotic plaques, a key event triggering acute myocardial infarction. In addition, studies have reported that the PKC-MEK-PPARγ signaling pathway is involved in oxidized low-density lipoprotein (oxLDL)-induced expression of MMPs. Ellagic acid, a phenolic compound found in fruits and nuts, has potent antioxidant, anti-inflammatory, and anticancerous properties. However, the molecular mechanisms underlying its antiatherogenic effects remain to be clarified. This study aimed to assess whether the effects of ellagic acid on the fibrotic markers MMP-1 and MMP-3 are modulated by the PKC-ERK-PPAR-γ signaling pathway in human umbilical vein endothelial cells (HUVECs) that have been exposed to oxLDL. It was found that ellagic acid significantly inhibited oxLDL-induced expressions of MMP-1 and MMP-3. Pretreatment with ellagic acid and DPI, a well-known ROS inhibitor, attenuated the oxLDL-induced expression and activity of PKC-α. In addition, ellagic acid as well as pharmacological inhibitors of ROS, calcium, and PKC strongly suppressed the oxLDL-induced phosphorylation of extracellular signal-regulated kinase (ERK) and NF-κB activation. Moreover, ellagic acid ameliorated the oxLDL-induced suppression of PPAR-γ expression. In conclusion, the data suggest that ellagic acid elicits its protective effects by modulating the PKC-α/ERK/PPAR-γ/NF-κB pathway, resulting in the suppression of ROS generation and, ultimately, inhibition of MMP-1 and MMP-3 expression in HUVECs exposed to oxLDL. 相似文献
60.
Md. Yunus Miah Chih-Yu Chiu Hiroaki Hayashi Mitsuo Chino 《Soil Science and Plant Nutrition》2013,59(4):787-796
Analysis of the effect of slow-releasing N fertilizers on microbial parameters of the rhizosphere soil is essential for their effective use. This investigation revealed the comparative effects of oxamide and ammonium sulfate as different N sources on some selected microbial parameters as well as the pH in the rhizosphere of wheat (Triticum aestivum cv. Nourin No. 61). The study was conducted on a Japanese upland alluvial soil using a rhizobox system. In the central compartment (CC) of the rhizoboxes treated with oxamide and ammonium sulfate, four wheat seedlings were grown for 53 d. In either of the treatments, the pH of the rhizosphere soil increased with the increase in the distance from the CC. In contrast, nitrate production, bacterial and fungal numbers, microbial biomass nitrogen, and β-acetylglucosaminidase activity decreased with the increase in the distance, with the highest values of the respective parameters being recorded in the CC. However, remarkable changes of these microbial parameters were found within a distance of 1–2 mm from the CC to the distant compartments. Thus the results indicated that pH, bacterial number, and nitrate production were high in the oxamide treatment. In contrast, higher fungal number, microbial biomass N, and .B-acetylglucosaminidase activity were associated with the ammonium sulfate treatment. It was assumed that the significant (p<O.05) effect of the rhizosphere on microbial activities varied with the treatments. 相似文献