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41.
Ecdysteroid glycosides from Sida rhombifolia L 总被引:1,自引:0,他引:1
Seven ecdysteroids, including the three new compounds 1-3, were isolated from Sida rhombifolia L. Their structures and configurations were determined by extensive spectroscopic techniques in combination with chemical derivatization. The four known compounds--ecdysone (4), 20-hydroxyecdysone (5), 2-deoxy-20-hydroxyecdysone-3-O-beta-D-glucopyranoside (6), and 20-hydroxyecdysone-3-O-beta-D-glucopyranoside (7)--are reported for the first time from this plant. 相似文献
42.
Background
The entire gastrointestinal tract is protected by a mucous layer, which contains complex glycoproteins called mucins. MUC2 is one such mucin that protects the colonic mucosa from invading microbes. The initial interaction between microbes and mucins is an important step for microbial pathogenesis. Hence, it was of interest to investigate the relationship between host (mucin) and pathogen interaction, including Shigella induced expression of MUC2 and IL-1β during shigellosis.Methods
The mucin-Shigella interaction was revealed by an in vitro mucin-binding assay. Invasion of Shigella dysenteriae into HT-29 cells was analyzed by Transmission electron microscopy. Shigella induced mucin and IL-1β expression were analyzed by RT-PCR and Immunofluorescence.Results
The clinical isolates of Shigella were found to be virulent by a congo-red binding assay. The in vitro mucin-binding assay revealed both Shigella dysenteriae and Shigella flexneri have binding affinity in the increasing order of: guinea pig small intestinal mucinConclusions
Our study concludes that the Shigella species specifically binds to guinea pig colonic mucin, but not to guinea pig small intestinal mucin. The guinea pig colonic mucin showed a greater binding parameter (R), and more saturable binding, suggesting the presence of a finite number of receptor binding sites in the colonic mucin of the host. In addition, modification of mucins with TFMS and sodium metaperiodate significantly reduced mucin-bacterial binding; suggesting that the mucin-Shigella interaction occurs through carbohydrate epitopes on the mucin backbones. Overproduction of MUC2 may alter adherence and invasion of Shigella dysenteriae into human colonic epithelial cells. 相似文献43.
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Eric S. Goetzman John F. Alcorn Sivakama S. Bharathi Radha Uppala Kevin J. McHugh Beata Kosmider Rimei Chen Yi Y. Zuo Megan E. Beck Richard W. McKinney Helen Skilling Kristen R. Suhrie Anuradha Karunanidhi Renita Yeasted Chikara Otsubo Bryon Ellis Yulia Y. Tyurina Valerian E. Kagan Rama K. Mallampalli Jerry Vockley 《The Journal of biological chemistry》2014,289(15):10668-10679
Long-chain acyl-CoA dehydrogenase (LCAD) is a mitochondrial fatty acid oxidation enzyme whose expression in humans is low or absent in organs known to utilize fatty acids for energy such as heart, muscle, and liver. This study demonstrates localization of LCAD to human alveolar type II pneumocytes, which synthesize and secrete pulmonary surfactant. The physiological role of LCAD and the fatty acid oxidation pathway in lung was subsequently studied using LCAD knock-out mice. Lung fatty acid oxidation was reduced in LCAD−/− mice. LCAD−/− mice demonstrated reduced pulmonary compliance, but histological examination of lung tissue revealed no obvious signs of inflammation or pathology. The changes in lung mechanics were found to be due to pulmonary surfactant dysfunction. Large aggregate surfactant isolated from LCAD−/− mouse lavage fluid had significantly reduced phospholipid content as well as alterations in the acyl chain composition of phosphatidylcholine and phosphatidylglycerol. LCAD−/− surfactant demonstrated functional abnormalities when subjected to dynamic compression-expansion cycling on a constrained drop surfactometer. Serum albumin, which has been shown to degrade and inactivate pulmonary surfactant, was significantly increased in LCAD−/− lavage fluid, suggesting increased epithelial permeability. Finally, we identified two cases of sudden unexplained infant death where no lung LCAD antigen was detectable. Both infants were homozygous for an amino acid changing polymorphism (K333Q). These findings for the first time identify the fatty acid oxidation pathway and LCAD in particular as factors contributing to the pathophysiology of pulmonary disease. 相似文献
45.
Solvatochromic study of 3‐N‐(N′‐methylacetamidino)benzanthrone and its interaction with dopamine by the fluorescence quenching mechanism 下载免费PDF全文
D. Bharathi B. Siddlingeshwar Shivraj Anup Thomas Elena M. Kirilova Irena Nikolajeva 《Luminescence》2018,33(3):528-537
The change in photophysical properties of the organic molecule due to solvatochromic effect caused by different solvent environments at room temperature gives information about the dipole moments of 3‐N‐(N′‐methylacetamidino)benzanthrone (3‐MAB). The quantum yield, fluorescence lifetime of 3‐MAB was measured in different solvents to calculate radiative and non‐radiative rate constants. The results revealed that the excited state dipole moment (μe) is relatively larger compared to the ground state dipole moment (μg), indicating the excited state of the dye under study is more polar than the ground state and the same trend is noticed with theoretical calculations performed using the CAM‐B3LYP/6‐311+G(d,p) method. Further, the study on preferential solvation was carried out for 3‐MAB dye in ethyl acetate–methanol solvent mixture. The fluorescence quenching method has been employed for the detection of dopamine using 3‐MAB as fluorescent probe, using steady‐state and time resolved methods at room temperature. The method enables dopamine in the micro molar range to be detected. Also, an attempt to verify the quenching process by employing different models has been tried. Various rate parameters are measured using these models, our results indicates the quenching process is diffusion limited. 相似文献
46.
Npp106p, a Schizosaccharomyces pombe nucleoporin similar to Saccharomyces cerevisiae Nic96p, functionally interacts with Rae1p in mRNA export. 下载免费PDF全文
To identify components of the mRNA export machinery in Schizosaccharomyces pombe, a screen was developed to identify mutations that were synthetically lethal with the conditional mRNA export allele rae1-167. Mutations defining three complementation groups were isolated, and here we report the characterization of npp106 (for nuclear pore protein of 106 kDa). This gene encodes a predicted protein that has significant similarity to the Nic96p nucleoporin of Saccharomyces cerevisiae. Consistent with Npp106p being a nucleoporin, a functional green fluorescent protein (GFP)-tagged Npp106p localized to the nuclear periphery. In contrast to NIC96, the npp106 gene is not essential. Moreover, a delta npp106 mutant did not show cytoplasmic mislocalization of a simian virus 40 nuclear localization signal-GFP-LacZ reporter protein, and a fraction of cells had accumulation of poly(A)+ RNA in the nucleus. A consequence of the synthetic lethality between rae1-167 and npp106-1 was the accumulation of poly(A)+ RNA in the nucleus when cells were grown under synthetic lethal conditions. In addition to npp106-1, which is a nonsense mutation that truncates the protein at amino acid 292, the delta npp106 mutation was synthetically lethal with rae1-167, suggesting that the synthetic lethality is a consequence of the loss of a function of npp106. We further demonstrate that a region between amino acids 74 and 348 of Npp106p is required for complementation of the synthetic lethality. These results uncover a potential direct or indirect involvement of Npp106p in mRNA export. 相似文献
47.
S?R?Bharathi?Devi Aloysius?Dhivya M K?N?SulochanaEmail author 《Journal of biosciences》2016,41(3):487-496
Copper, although known as a micronutrient, has a pivotal role in modulating the cellular metabolism. Many studies have reported the role of copper in angiogenesis. Copper chaperones are intracellular proteins that mediate copper trafficking to various cell organelles. However, the role and function of copper chaperones in relation to angiogenesis has to be further explored. The intracellular copper levels when in excess are deleterious and certain mutations of copper chaperones have been shown to induce cell death and influence various cellular metabolisms. The study of these chaperones will be helpful in understanding the players in the cascade of events in angiogenesis and their role in cellular metabolic pathways. In this review we have briefly listed the copper chaperones associated with angiogenic and metabolic signalling and their function. 相似文献
48.
分析克拉玛依市麻疹流行状况及预防控制措施,为消除麻疹提供依据。采用描述流行病学分析方法,对2008年克拉玛依市麻疹资料进行分析。结果显示,克拉玛依市2008年麻疹发病率为38.83/10万(138/355381),呈高度散发,较2007年有所上升。发病高峰在3~5月,发病数占全年的83.33%。年龄分布大年龄组高于小年龄组,>20岁年龄组病例占50.00%,<1岁病例占18.84%;流动人口发病占51.11%。应切实提高麻疹常规免疫接种率和做好入托、入学儿童查验预防接种证工作,加强麻疹监测,提高实验室确诊病例的比例。 相似文献
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