The expression changes of Rars gene in ischemia-injured neurons were investigated by detecting its translational product arginyl-t RNA synthetase（Arg RS）, and the inhibitory effects of ischemic preconditioning（IPC...The expression changes of Rars gene in ischemia-injured neurons were investigated by detecting its translational product arginyl-t RNA synthetase（Arg RS）, and the inhibitory effects of ischemic preconditioning（IPC） on Rars gene were explored. Both IPC model and prolonged ischemia（PI） model were established by using the classic oxygen glucose deprivation（OGD） method. The primary cultured neurons were assigned into the following groups： the experimental group（IPC＋PI group）, undergoing PI after a short period of IPC; the conditional control group（PI control group）, subjected to PI without IPC; blank control group, the normally cultured neurons. The Rars transcriptional activities and Arg RS expression levels were measured at different time points after re-oxygenation（3 h/6 h/12 h/24 h）. Data were collected and statistically analyzed. Compared to the blank control group, the Rars activities and Arg RS levels were significantly increased in PI control group, peaking at the time point of 6 h after re-oxygenation. Rars activities and Arg RS levels were significantly lower in the experimental group than in the PI control group at different time points after re-oxygenation. PI insult can induce an escalating activity of Rars and lead to Arg RS over-expression in primary cultured neurons. IPC can inhibit the increased Rars activity and down-regulate Arg RS expression of ischemia-insulted neurons. This mechanism may confer ischemic tolerance on neurons.展开更多
A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer...A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer cells. We examined retinoic acid receptors (RARs) and retinoids X receptors (RXRs) levels in 6 breast carcinoma cell lines and 18 breast cancer biopsy specimens. We found that RAR-α mRNA level was significantly higher in ER positive cell lines and samples. RAR-γ mRNA was expressed at relatively high levels in majority of tumor samples independent of the ER-status while RAR-β mRNA was expressed at low levels. We also found high RXR-α mRNA levels in all of the tumor samples examined while RXR-γ mRNA could not be detected. Our study suggests a possibility that retinoids inhibit tumor cell growth through RAR-a and RAR-α levels may serve as a potential marker to determine responsiveness of patients to retinoids therapy.展开更多
To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in Septemb...To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.展开更多
基金supported by the National Natural Science Foundation of China(No.81371453)
文摘The expression changes of Rars gene in ischemia-injured neurons were investigated by detecting its translational product arginyl-t RNA synthetase（Arg RS）, and the inhibitory effects of ischemic preconditioning（IPC） on Rars gene were explored. Both IPC model and prolonged ischemia（PI） model were established by using the classic oxygen glucose deprivation（OGD） method. The primary cultured neurons were assigned into the following groups： the experimental group（IPC＋PI group）, undergoing PI after a short period of IPC; the conditional control group（PI control group）, subjected to PI without IPC; blank control group, the normally cultured neurons. The Rars transcriptional activities and Arg RS expression levels were measured at different time points after re-oxygenation（3 h/6 h/12 h/24 h）. Data were collected and statistically analyzed. Compared to the blank control group, the Rars activities and Arg RS levels were significantly increased in PI control group, peaking at the time point of 6 h after re-oxygenation. Rars activities and Arg RS levels were significantly lower in the experimental group than in the PI control group at different time points after re-oxygenation. PI insult can induce an escalating activity of Rars and lead to Arg RS over-expression in primary cultured neurons. IPC can inhibit the increased Rars activity and down-regulate Arg RS expression of ischemia-insulted neurons. This mechanism may confer ischemic tolerance on neurons.
文摘A number of studies have been shown that retiniods can inhibit malignant cell growth including certain breast carcinoma cells. Its inhibitory effort is observed only in ER-positive but not in ER-negative breast cancer cells. We examined retinoic acid receptors (RARs) and retinoids X receptors (RXRs) levels in 6 breast carcinoma cell lines and 18 breast cancer biopsy specimens. We found that RAR-α mRNA level was significantly higher in ER positive cell lines and samples. RAR-γ mRNA was expressed at relatively high levels in majority of tumor samples independent of the ER-status while RAR-β mRNA was expressed at low levels. We also found high RXR-α mRNA levels in all of the tumor samples examined while RXR-γ mRNA could not be detected. Our study suggests a possibility that retinoids inhibit tumor cell growth through RAR-a and RAR-α levels may serve as a potential marker to determine responsiveness of patients to retinoids therapy.
文摘To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.
