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1.
Nonparametric spline regression with prior information 总被引:1,自引:0,他引:1
2.
In order to investigate gene expression changes associated with cytotoxicity, we used cDNA arrays to monitor the expression
of over 5,000 genes in response to toxic stress in the HepG2 liver cell line. Cells were treated with cytotoxic doses of acetaminophen,
caffeine or thioacetamide for nine time points ranging from 1 to 24 h. Samples of mRNA from each time point were used to prepare
radiolabeled cDNA, which was hybridized to nylon-membrane-based cDNA arrays. High-stringency washes were applied to reduce
cross-hybridization. Analysis of spot intensities revealed that each compound led to approximately 150-250 gene expression
changes that were sustained over at least three adjacent time points. The affected genes could be classified into clusters
based on their temporal patterns of differential expression. A common set of 44 genes showed similar expression changes in
response to all three compounds. Of these changes, 90% could be confirmed by quantitative RT-PCR analysis. The results indicate
that detailed array-based time-course studies, coupled with a sensitive and highly specific confirmation assay, provide a
powerful means of identifying cytotoxicity-associated gene expression changes.
Electronic Publication 相似文献
3.
Dry mixtures of sonicated vesicles of DPPC and trehalose which contained a maximum of 0.2 mol water/mol lipid were examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and freeze-fracture electron microscopy. Samples of dry DPPC and trehalose prepared from aqueous solution had a minimum Tm of 24°C for the gel to liquid-crystalline transition provided that the vesicles were dried with trehalose while the lipid was in liquid-crystalline phase. This low transition is compared to a transition of 105–112°C for dry pure DPPC and of 42°C for hydrated pure DPPC. The present work is an extension of earlier work from this laboratory using both other lipids and other methods of preparation. 相似文献
4.
Yung-Shun Su Ming-Jen Cheng Ming-Der Wu Chee-Yin Chai Aij-Lie Kwan Sheng-Han Su Yueh-Hsiung Kuo 《化学与生物多样性》2021,18(8):e2100211
Cultivation of the actinobacteria strain Isoptericola chiayiensis, a mangrove - derived actinobacteria that was isolated from a mangrove soil collected in Chiayi County, resulted in the isolation of one new 2-furanone derivative, isopterfuranone ( 1 ), one new sesquiterpenoid, isopterchiayione ( 2 ), one new benzenoid derivative, isopterinoid ( 3 ), five new flavonoids, chiayiflavans A−E ( 4 – 8 ), and 4 metabolites isolated for the first time from nature source, methyl 3-(4-methyl-2,5-dioxopyrrolidin-3-yl)propanoate ( 9 ), 3-ethyl-4-methylpyrrolidine-2,5-dione ( 10 ), chiayiensol ( 11 ) and chiayiensic acid ( 12 ). Their structures were determined through in-depth spectroscopic and mass-spectrometric analyses. Most of the isolates showed potent inhibitory effects on NO production in LPS-stimulated RAW 264.7 murine macrophages cells with IC50 values ranging from 9.36 to 40.02 μM. Of these isolates, 4 and 5 showed NO inhibitory activity with IC50 values of 17.14 and 9.36 μM, stronger than the positive control quercetin (IC50=36.95 μM). This is the first report on flavan metabolites from the genus Isoptericola. 相似文献
5.
David R. Nelson 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1612)
The world we live in is a biosphere influenced by all organisms who inhabit it. It is also an ecology of genes, with some having rather startling effects. The premise put forth in this issue is cytochrome P450 is a significant player in the world around us. Life and the Earth itself would be visibly different and diminished without cytochrome P450s. The contributions to this issue range from evolution on the billion year scale to the colour of roses, from Darwin to Rachel Carson; all as seen through the lens of cytochrome P450. 相似文献
6.
Environmental inputs during early development can shape the expression of phenotypes, which has long‐lasting consequences in physiology and life history of an organism. Here, we study whether experimentally manipulated availability of dietary antioxidants, vitamins C and E, influences the expression of genetic variance for antioxidant defence, endocrine signal and body mass in yellow‐legged gull chicks using quantitative genetic models based on full siblings. Our experimental study in a natural population reveals that the expression of genetic variance in total antioxidant capacity in plasma increased in chicks supplemented with vitamins C and E despite the negligible effects on the average phenotype. This suggests that individuals differ in their ability to capture and transport dietary antioxidants or to respond to these extra resources, and importantly, this ability has a genetic basis. Corticosterone level in plasma and body mass were negatively correlated at the phenotypic level. Significant genetic variance of corticosterone level appeared only in control chicks nonsupplemented with vitamins, suggesting that the genetic variation of endocrine system, which transmits environmental cues to adaptively control chick development, appeared in stressful conditions (i.e. poor antioxidant availability). Therefore, environmental inputs may shape evolutionary trajectories of antioxidant capacity and endocrine system by affecting the expression of cryptic genetic variation. 相似文献
7.
This paper is concerned with gene survival in a population which may increase without density dependence according to a generalization of the Moran model for haploid individuals. A selective advantage to one allele and the possibility of differential reproductive rates are allowed. Simple conditions are given for ultimate homozygosity to be certain and for the possibility of ultimate polymorphism. The results complement and extend those of Heyde (1981, 1982). 相似文献
8.
Metabolites of corticosteroids that contain the 21-oic acid moiety are found in human urine. The acids from neutral steroids and urinary pigments have been separated by passing the mixture through a column of polyethyleneimine cellulose. The acids adhering to the column are quantitatively eluted with dilute formic acid. The purified preparation is suitable for derivatization and chromatographic analysis. 相似文献
9.
《Fungal Ecology》2016
Competition between mycelia of saprotrophic cord-forming basidiomycetes occurs both within dead woody resources and in the soil-litter interface, and involves a variety of antagonistic mechanisms including the production of volatile organic compounds (VOCs). The antagonistic potential of VOC profiles from interactions in wood blocks and in soil microcosms was assessed using shared headspace experiments, and the profile of VOCs emitted over the course of interactions elucidated using solid phase microextraction (SPME) with gas chromatography-mass spectrometry (GC–MS). Quantitative and qualitative changes in VOC production occurred in interactions compared to self-pairing controls, with different VOC profiles from fungi growing in wood blocks compared to soil trays. There were both stimulatory and inhibitory effects of VOCs on target mycelial extension rate, hyphal coverage and fractal dimension. VOC-mediated effects were greater in self-pairing controls compared to interactions, and differed depending on the substratum in which the VOC-producing fungi were growing. 相似文献
10.
Allen Hirsh 《生物化学与生物物理学报:生物膜》1983,733(1):186-188
It is demonstrated that the phase changes reported for a quick frozen calcium cardiolipin solution containing CaCl2 are virtually identical to those seen in pure CaCl2. This introduces uncertainty as to whether the data in fact reflect the behavior of cardiolipin or of the associated CaCl2. 相似文献