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91.
Profiling Expression Patterns and Isolating Differentially Expressed Genes by cDNA Microarray System with Colorimetry Detection 总被引:1,自引:0,他引:1
Jeremy J.W. Chen Reen Wu Pan-Chyr Yang Jane-Yu Huang Yuh-Pyng Sher Meng-Hsuan Han Wei-Chen Kao Pei-Jung Lee Trai Fu Chiu Fu Chang Yi-Wen Chu Cheng-Wen Wu Konan Peck 《Genomics》1998,51(3):313
A high-density cDNA microarray with colorimetry detection system to simultaneously monitor the expression of many genes on nylon membrane is described and characterized. To quantify the expression of genes and to isolate differentially expressed genes, the southern hybridization process on filter membranes was employed. The levels of gene expression were represented by color intensities generated by colorimetric reactions in place of hazardous radioisotopes or costly laser-induced fluorescence detection. The gene expression patterns on nylon membranes were digitized by devices such as an economical flatbed scanner or a digital camera. The quantitative information of gene expression was retrieved by image analysis software. Quantitative comparison of the northern dot-blotting method with the microarray system is described. Applications employing single-color detection as well as dual-color detection to isolate differentially expressed genes among thousands of genes are demonstrated. 相似文献
92.
采用80%丙酮提取物的水萃取部位,利用凝胶、MCI、反相碳18、及 Toyopearl Butyl-650C 柱色谱进行分离纯化得到7个黄酮和3个苯乙醇苷类化合物。根据化合物的波谱数据分析鉴定为槲皮素(1)、槲皮苷(2)、异懈皮苷(3)、芦丁(4)、异牡荆素(5)、牡荆素(6)、木犀草素-7-O-α-L-鼠李糖(1→6)-β-D-葡萄糖苷(7)、2-phenethylβ-D-glucoside(8)、icariside D1(9)、2-苯乙基-D-芸香甙(10)。其中化合物1-3、5-6、8-10为首次从本属植物中分离得到。 相似文献
93.
94.
Estimating the rate of evolution of the rate of molecular evolution 总被引:22,自引:13,他引:22
A simple model for the evolution of the rate of molecular evolution is
presented. With a Bayesian approach, this model can serve as the basis for
estimating dates of important evolutionary events even in the absence of
the assumption of constant rates among evolutionary lineages. The method
can be used in conjunction with any of the widely used models for
nucleotide substitution or amino acid replacement. It is illustrated by
analyzing a data set of rbcL protein sequences.
相似文献
95.
Background
Computational prediction methods are currently used to identify genes in prokaryote genomes. However, identification of the correct translation initiation sites remains a difficult task. Accurate translation initiation sites (TISs) are important not only for the annotation of unknown proteins but also for the prediction of operons, promoters, and small non-coding RNA genes, as this typically makes use of the intergenic distance. A further problem is that most existing methods are optimized for Escherichia coli data sets; applying these methods to newly sequenced bacterial genomes may not result in an equivalent level of accuracy. 相似文献96.
Multiple forms of tubulin in the cytoskeletal and flagellar microtubules of polytomella 总被引:5,自引:9,他引:5 下载免费PDF全文
The alga polytomella contains several organelles composed of microtubules, including four flagella and hundreds of cytoskeletal microtubules. Brown and co-workers have shown (1976. J. Cell Biol. 69:6-125; 1978, Exp. Cell Res. 117: 313-324) that the flagella could be removed and the cytoskeletans dissociated, and that both structures could partially regenerate in the absence of protein synthesis. Because of this, and because both the flagella and the cytoskeletons can be isolated intact, this organism is particularly suitable for studying tubulin heterogeneity and the incorporation of specific tubulins into different microtubule-containing organelles in the same cell. In order to define the different species of tubulin in polytonella cytoplasm, a (35)S- labeled cytoplasmic fraction was subjected to two cycles of assembly and disassembly in the presence of unlabeled brain tubulin. Comparison of the labeled polytomella cytoplasmic tubulin obtained by this procedure with the tubulin of isolated polytomella flagella by two-dimensional gel electrophoresis showed that, whereas the β-tubulin from both cytoplasmic and flagellar tubulin samples comigrated, the two α-tubulins had distinctly different isoelectic points. As a second method of isolating tubulin from the cytoplasm, cells were gently lysed with detergent and intact cytoskeletons obtained. When these cytoskeletons were exposed to cold temperature, the proteins that were released were found to be highly enriched in tubulin; this tubulin, by itself, could be assembled into microtubules in vitro. The predominant α-tubulin of this in vitro- assembled cytoskeletal tubulin corresponded to the major cytoplasmic α-tubulin obtained by coassembly of labeled polytomella cytoplasmic extract with brain tubulin and was quite distinct from the α-tubulin of purified flagella. These results clearly show that two different microtubule-containing organelles from the same cell are composed of distinct tubulins. 相似文献
97.
Influenza virus infection increases p53 activity: role of p53 in cell death and viral replication 总被引:5,自引:0,他引:5 下载免费PDF全文
Turpin E Luke K Jones J Tumpey T Konan K Schultz-Cherry S 《Journal of virology》2005,79(14):8802-8811
98.
H. Benbouza J. M. Lacape J. M. Jacquemin B. Courtois F. B. H. Diouf D. Sarr N. Konan J. P. Baudoin G. Mergeai 《Molecular breeding : new strategies in plant improvement》2010,25(2):273-286
In order to select genotypes of Gossypium hirsutum genetically balanced and expressing the low-gossypol seed & high-gossypol plant trait introgressed from the Australian wild diploid species G. sturtianum, the [(G. hirsutum × G. raimondii)2 × G. sturtianum] triple hybrid was backcrossed to G. hirsutum and autopollinated to produce backcross and selfed progenies. Two hundred and six mapped SSR markers of G. hirsutum were used to monitor the introgression of SSR alleles specific to G. sturtianum and G. raimondii in the selected progenies. A high level of heterozygosity, varying from 25 to 100%, was observed for all G. sturtianum-specific SSR markers conserved in the most advanced progenies. These results indicate the existence of segregation distortion
factors that are associated with the genes controlling the researched trait. This study represents a starting point to map
the genes involved in the expression of the trait and better understand its genetic determinism. 相似文献
99.
N. Kouamé D. Koffi A.M. N’goan-Domoua A. Sétchéou G.A. Houé A.N. Konan O.D. Tra-Bi A. Kouamé-Koutouan R.D. N’gbesso A.K. Kéita 《Médecine Nucléaire》2011,35(10):533-536
ObjectiveThe aim of this study was to demonstrate the role of the Doppler ultrasound examination in the management of diabetic feet and particularly in the prevention of the diabetic's amputation.Patients and methodIt is about a retrospective study carried out over a 4-year period at Yopougon University Hospital (Abidjan, Côte d’Ivoire). It consisted in the analysis of the records of 78 patients hospitalized for diabetic foot and in whom was performed a Doppler ultrasound examination of the lower limbs vessels. The analysis of patients’ records helped to bring out the epidemiological, clinical, radiographic, biologic, therapeutic and evolutional elements.ResultsPatients’ mean age was 57.6 years. The sex ratio was 1.05. Adult diabetes accounted for 93.5% of cases and had been developing for 11.49 years on average. On the Doppler ultrasound scan of the lower limbs arterial anomalies of these limbs were found in 70 cases. They were associated with a venous anomaly in four cases. Arterial anomalies were represented by stenosis (34 cases), occlusions (10 cases), medialarterosclerosis (four cases), small arteries (six cases) and the associations of several elementary lesions (nine cases). In three cases, the arterial abnormality was not indicated. A medical treatment was instituted for all the patients. The outcome was favorable for 61 patients, 13 were amputated and four deaths were recorded.ConclusionColor Doppler ultrasound examination of lower limbs vessels helped to bring out a vascular anomaly in 89.7% of patients with diabetic foot whose treatment helped to keep the lower limb in 78.2%. We recommend the systematic request of this examination in the African diabetic with adult diabetes which has been developing for more than 10 years before the onset of diabetic foot. 相似文献
100.
Effect of oxygen tension on human peripheral blood leukocytes: lysosomal enzyme release and metabolic responses during phagocytosis 总被引:2,自引:0,他引:2 下载免费PDF全文
JL Skosey DC Chow S Nusinow J May V Gestautas Y Niwa 《The Journal of cell biology》1981,88(2):358-363
We found that nonlethal lysosomal enzyme release from human peripheral blood leukocytes during phagocytosis of opsonized zymosan in vitro was modified by the oxygen tension under which the cells were incubated; with decreasing Po(2), zymosan-induced release of lysosomal enzymes was potentiated. The effect on enzyme release could not be attributed secondarily to an effect on phagocytosis, because, as others have reported, Po(2) had little effect on that response. Metabolic responses that accompany phagocytosis were also modified by oxygen tension. Stimulation of oxidation by way of the pentose cycle was further enhanced by increasing Po(2). Conversely, anaerobic glycolysis was promoted by decreasing oxygen tension. ATP levels fell as a function of time and concentration of phagocytic stimulus, mirroring lysosomal enzyme release as modified by Po(2). Cyclic AMP levels fell during phagocytosis and lysosomal enzyme release, a change that could act to facilitate lysosomal enzyme release. However, the fall in nucleotide level was greatest with highest Po(2) (i.e., when lysosomal enzyme release was least). The inverse relationship between oxidative metabolism and enzyme release suggested that a product of oxidative metabolism might adversely influence enzyme release. Sulfhydryl antioxidants (Cysteine, glutathione) and scavengers of oxygen-derived reactants (superoxide dismutase, catalase, benzoate, hypoxanthine, xanthine, histidine, azide) all potentiated zymosan- stimulated enzyme release. These findings are consistent with the interpretation that one or more factors (e.g., superoxide anion, hydrogen peroxide, hydroxyl radical, singlet oxygen), generated in association with the burst of oxidative metabolism which accompanies phagocytosis, acts to inhibit lysosomal enzyme release. 相似文献