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21.
Nabil Elsayed Allen Hacker Mohammad Mustafa Klaus Kuehn Gerhard Schrauzer 《Biochemical and biophysical research communications》1982,104(2):564-569
The effects of reducing glutathione peroxidase activity in the lung by changing dietary selenium intake has been investigated. In animals that were exposed to room air, selenium effects were confined to glutathione peroxidase activity, whereas under conditions of oxidant stress (ozone) the decrease in glutathione peroxidase activity prevented the stimulation of the pentose phosphate cycle (assayed by measuring glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities) which has been reported to increase in response to oxidant stress. The suppression of glutathione peroxidase activity was found to depend on dietary selenium concentration. The physiological significance of this observation may be related to the process of injury and repair in the lung. 相似文献
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Chitooligosaccharides are nontoxic and water-soluble compounds obtained by enzymatic degradation of chitosan, which is derived from chitin by a deacetylation process. Chitooligosaccharides possess broad range of activities such as antitumour, antifungal, antibacterial activities. Sulfated chitooligosaccharides (SCOSs) with different molecular weights were synthesized by a random sulfation reaction. In the present study, anti-HIV-1 properties of SCOSs and the impact of molecular weight on their inhibitory activity were investigated. SCOS III (MW 3-5 kDa) was found to be the most effective compound to inhibit HIV-1 replication. At nontoxic concentrations, SCOS III exhibited remarkable inhibitory activities on HIV-1-induced syncytia formation (EC50 2.19 μg/ml), lytic effect (EC50 1.43 μg/ml), and p24 antigen production (EC50 4.33 μg/ml and 7.76 μg/ml for HIV-1RF and HIV-1Ba-L, respectively). In contrast, unsulfated chitooligosaccharides showed no activity against HIV-1. Furthermore, it was found that SCOS III blocked viral entry and virus-cell fusion probably via disrupting the binding of HIV-1 gp120 to CD4 cell surface receptor. These results suggest that sulfated chitooligosaccharides represent novel candidates for the development of anti-HIV-1 agent. 相似文献
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Bardees Mickky Heshmat Aldesuquy Mustafa Elnajar 《Physiology and Molecular Biology of Plants》2020,26(6):1111-1117
Flag leaf and shoot growth at heading stage as well as ultimate yield capacity of ten wheat cultivars were assessed in a pot experiment under normal and drought conditions. Drought was imposed by withholding 25% of field capacity from the 45- day old plants for 21 days followed by normal irrigation until maturity. Leaf succulence degree and stomatal opening area as well as shoot biomass, density and distribution decreased in all cultivars in response to drought but to different degrees. On contrary, leaf sclerophylly degree and water saturation deficit increased in all cultivars as a result of drought. At the same time, drought caused marked alterations in leaf transpiration rate, hair features, abscisic acid content, osmotic adjustment and fatty acid profile of the concerned cultivars; with ultimate variable capacity for yield. The drought- induced changes in the estimated traits were graphically represented in a single map then they were correlated with each other. The considered cultivars could be eventually clustered based on their drought response; with Sids cultivars being the most drought tolerant whereas Shandaweel 1 and Giza 168 being the most sensitive. 相似文献
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Previous studies have indicated that there is no consensus on the effects of extremely low‐frequency electromagnetic (ELF‐EMF) exposure on the cardiovascular system. This study aimed to explore the short‐term effect of ELF‐EMF exposure on heart rate (HR) and HR variability (HRV). The sample consisted of 34 healthy males aged 18–27 years. The participants were randomly assigned to the EMF (n = 17) or the Sham group (n = 17). We employed a double‐blind repeated‐measures design consisting of three 5 min experimental periods. The chest region of each individual in the EMF group was exposed to 50 Hz, 28 μT, linear polarized, continuous EMF during the EMF exposure period. HR and HRV data were recorded continuously by using a photoplethysmography sensor. Within‐subject statistical analysis indicated a significant HR deceleration in both the EMF and Sham groups. However, the standard deviation of the NN intervals (SDNN), root mean square of successive differences (RMSSD), low‐frequency (LF), and high‐frequency (HF) powers increased only in the EMF group and remained stable in the Sham group. We also compared the same HRV indices measured during the EMF and Sham periods between the two experimental groups. The between‐subject analysis results demonstrated significantly higher SDNN, RMSSD, LF, and HF values in the EMF group than in the Sham group. The LF/HF ratio did not change significantly within and between groups. On the basis of these results, we concluded that short‐term exposure of the chest region to ELF‐EMF could potentially enhance parasympathetic predominance during the resting condition. Bioelectromagnetics. 2021;42:60–75. © 2020 Bioelectromagnetics Society. 相似文献
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Kim Jung-Il Karagozlu Mustafa Zafer An Hyung-Eun Choi Tae-June Yeo Yonggu Kim Chang-Bae 《Molecular biology reports》2021,48(7):5787-5793
Molecular Biology Reports - Trichoglossus haematodus is the most popular parrots globally and one of the most bred species in Korea's zoos. However, despite its popularity, there are limited... 相似文献