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41.
Srivastava BK Soni R Joharapurkar A Sairam KV Patel JZ Goswami A Shedage SA Kar SS Salunke RP Gugale SB Dhawas A Kadam P Mishra B Sadhwani N Unadkat VB Mitra P Jain MR Patel PR 《Bioorganic & medicinal chemistry letters》2008,18(3):963-968
Design, synthesis and conformational analysis of few imidazole and oxazole as bioisosters of 4S-(-)-3-(4-chlorophenyl)-N-methyl-N'-[(4-chlorophenyl)-sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-caboxamidine (SLV-319) 2 is reported. Computer assisted conformational analysis gave a direct clue for the loss of CB1 antagonistic activity of the ligands without a fine docking simulation for the homology model. 相似文献
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Athar M Chaudhury NK Hussain ME Varshney R 《Molecular and cellular biochemistry》2011,352(1-2):281-292
Oxidative stress and mitochondrial dysfunction in cancer cells represent features that may be exploited therapeutically. We determined whether minor groove binding ligand Hoechst 33342, known to induce mitochondrial dysfunction via increase in reactive oxygen species (ROS), enhances killing of human head and neck cancer (KB) cells mediated by impaired expression of mitochondrial protein involved in electron transfer. Elevation in ROS generation, increase in ΔΨm, down regulation of cytochrome c oxidase (CO), alteration in expression of antioxidant enzymes viz. Mn-SOD and Catalase, and release of cytochrome c into the cytosol, were observed in time-dependent manner when cells were irradiated (5 Gy) in presence of Hoechst 33342. Persistent increase in ROS observed till 48 h following treatment decreased the clonogenic survival and viability to a large extent via increase in ΔΨm, release of cytochrome c and non-coordinated expression of antioxidant enzymes. Treatment with antioxidants PEG-MnSOD and PEG-catalase inhibited the increase in ROS and loss of cell survival, suggesting the involvement of ROS in the Hoechst 33342-induced cell death. The result demonstrated significant sensitization of cancer cells to radiation-induced toxicity in presence of Hoechst 33342 via increasing ROS to a toxic level and impairing CO expression and antioxidant enzymes. This understanding is expected to benefit both in elucidating the detailed mechanisms of actions of DNA interacting drug and designing better molecules for enhancing radiation-induced cell death among cancer cells. 相似文献
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Polycomb group genes control pattern formation in plant seed 总被引:14,自引:0,他引:14
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Preeti Gupta Elizabeth Sidhartha Michael J. A. Girard Jean Martial Mari Tien-Yin Wong Ching-Yu Cheng 《PloS one》2014,9(5)
Purpose
To evaluate a simplified method to measure choroidal thickness (CT) using commercially available enhanced depth imaging (EDI) spectral domain optical coherence tomography (SD-OCT).Methods
We measured CT in 31 subjects without ocular diseases using Spectralis EDI SD-OCT. The choroid-scleral interface of the acquired images was first enhanced using a post-processing compensation algorithm. The enhanced images were then analysed using Photoshop. Two graders independently graded the images to assess inter-grader reliability. One grader re-graded the images after 2 weeks to determine intra-grader reliability. Statistical analysis was performed using intra-class correlation coefficient (ICC) and Bland-Altman plot analyses.Results
Using adaptive compensation both the intra-grader reliability (ICC: 0.95 to 0.97) and inter-grader reliability (ICC: 0.93 to 0.97) were perfect for all five locations of CT. However, with the conventional technique of manual CT measurements using built-in callipers provided with the Heidelberg explorer software, the intra- (ICC: 0.87 to 0.94) and inter-grader reliability (ICC: 0.90 to 0.93) for all the measured locations is lower. Using adaptive compensation, the mean differences (95% limits of agreement) for intra- and inter-grader sub-foveal CT measurements were −1.3 (−3.33 to 30.8) µm and −1.2 (−36.6 to 34.2) µm, respectively.Conclusions
The measurement of CT obtained from EDI SD-OCT using our simplified method was highly reliable and efficient. Our method is an easy and practical approach to improve the quality of choroidal images and the precision of CT measurement. 相似文献49.
N. Nogué H. Hocart D. S. Letham E. S. Dennis A. M. Chaudhury 《Plant Growth Regulation》2000,32(2-3):267-273
Cytokinins are involved in plant cell proliferation leading to plant growth and morphogenesis. Earlier we described a mutant of Arabidopsis thaliana, amp1, that had five times higher levels of cytokinin and had a number of pleiotropic phenotypes, including increased cell proliferation and de-etiolated growth in the dark. While these phenotypes were correlated with higher levels of cytokinin, the actual mechanism of how cytokinin is elevated was not elucidated before. In order to understand if the increased cytokinin is a result of increased biosynthesis or decreased degradation we have compared the synthesis of cytokinins from radiolabelled adenine and the degradation of zeatin ribosides and other cytokinins between amp1 and wild type plants. The degradation of the hormone is not affected in the mutant but there is a 4 to 6 fold increase in cytokinin synthesis compared to the wild type. Because the amp1 mutant is recessive we hypothesise that the AMP1 product negatively regulates cytokinin production. 相似文献
50.
A. M. Chaudhury S. Craig E. S. Dennis M. Lavithis P. E. Taylor M. B. Singh R. B. Knox E. R. Signer 《Sexual plant reproduction》1994,7(1):17-28
We have taken a mutational approach to identify genes important for male fertility in Arabidopsis thaliana and have isolated a number of nuclear male/ sterile mutants in which vegetative growth and female fertility are not altered. Here we describe detailed developmental analyses of four mutants, each of which defines a complementation group and has a distinct developmental end point. All four mutants represent premeiotic developmental lesions. In ms3, tapetum and middle layer hypertrophy result in the degeneration of microsporocytes. In ms4, microspore dyads persist for most of anther development as a result of impaired meiotic division. In ms5, degeneration occurs in all anther cells at an early stage of development. In ms15, both the tapetum and microsporocytes degenerate early in anther development. Each of these mutants had shorter filaments and a greater number of inflorescences than congenic male-fertile plants. The differences in the developmental phenotypes of these mutants, together with the non-allelic nature of the mutations indicate that four different genes important for pollen development, have been identified. 相似文献