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791.
Nowacka J Helszer Z Walter Z Płucienniczak A Kazewski B 《Acta biochimica Polonica》2004,51(4):995-1001
Pre- and postnatal diagnosis of chromosomal aberrations is generally based on conventional cytogenetic analysis. In this paper, we have devised a quantitative polymerase chain reaction (Q-PCR) method to determine gene dose effects and applied it in cases of regular trisomy 21 as a model. The method is based on quantitative assessment of PCR products after using primers amplifying DNA fragments located in the pericentromeric, heterochromatic, euchromatic and telomeric regions of chromosome 21. A gene dose effect on the amount of PCR product in cases of trisomy 21 was confirmed. Moreover, a correlation between the amount of the PCR product of the examined sequences and their location in the chromosome was observed. The obtained results suggest that the Q-PCR technique can be applied in the diagnosis of aneuploidies. 相似文献
792.
793.
794.
Development of new and more reliable methods to immobilise biomolecules has emerged rapidly due to a continuous need for more stable, sensitive and reliable biosensors. This paper reports a new method of acetylcholine-esterase (AChE) immobilisation based on the high affinity interaction between the glycoproteic enzyme and Concanavalin A (Con A). In order to establish the nature of the link formed between the glycoenzyme, lectin and support, three different configurations are presented. The optimum immobilisation procedure was further used for biosensor manufacturing. The non-specific adsorption is around 3% and the chemical cross-linking of the proteins is avoided. The optimised method allows loading of the working electrode surface with different amounts of enzyme ranging from 0.3 to 3.3 mIU with a good operational stability. The sensor showed a linear response range to acetylthiocholine substrate between 10 and 110 micromol l(-1) with a sensitivity of 3.6 mA l mol(-1). The applicability of the method to the detection of organophosphorus insecticides resulted in a detection limit of 10(-8) mol l(-1) for chlorpyriphos. 相似文献
795.
A linkage map of garden pea was constructed on the basis of 114 plants (F2 generation) derived from a cross combination Wt10245 x Wt11238. The map, consisting of 204 morphological, isozyme, AFLP, ISSR, STS, CAPS and RAPD markers, was used for interval mapping of quantitative trait loci (QTLs) controlling seed number, pod number, 1000-seed weight, 1000-yield, and seed protein content. Characterization of each QTL included identification of QTL position with reference to the flanking markers, estimation of the part of variance explained by this QTL, and determination of its gene action. The yield-related traits were measured in F2 plants and in F4 recombinant inbred lines (RILs). The interval mapping revealed two to six QTLs per trait, demonstrating linkage to seven pea chromosomes. A total of 37 detected QTLs accounted for 9.1-55.9% of the trait's phenotypic variation and showed different types of gene action. As many as eight and ten QTLs influencing the analysed traits were mapped in linkage groups III and V, respectively, indicating an important role of these regions of the pea genome in the control of yield and seed protein content. 相似文献
796.
Cugini P Touitou Y Bogdan A Auzéby A Pellegrino AM Fontana S Vacca K Siena GD Di Rosa R Zannella FP Zannella P Zannella A Sepe FA Sepe L 《Chronobiology international》2001,18(1):99-107
The study investigates the circadian rhythm (CR) of urinary 6-sulphatoxy-melatonin (aMT6s) in long-living (longevous) subjects and their progeny. The aim is to detect whether or not the melatonin CR is a physiological feature associated with healthy longevity. The aMT6s CR was investigated in 10 longevous subjects, 8 of their children and 9 of their grandchildren, all in good health. Control data were obtained respectively from 13 adult subjects and 9 young subjects, in good health, but characterized by a negative family history for longevity. All the subjects were born and living in the same city. The study was performed in the summer of 1996. The aMT6s CR was found to persist in longevous subjects, being characterized by a lower mesor and amplitude. The aMT6s CR was found not to show properties consistently different in children and grandchildren as compared respectively to their adult and young controls. Because of its preservation in longevous subjects, it can be argued that the melatonin CR is a physiological feature associated with healthy longevity. Because of the comparability of aMT6s CR in children and grandchildren, with respect to their controls without a positive family history of longevity, it can be argued that the melatonin CR is not a marker that can be used for an earlier identification of the candidates for longevity. 相似文献
797.
Evidence of prooxidant and antioxidant action of melatonin on human liver cell line HepG2 总被引:3,自引:0,他引:3
The aim of this study was to evaluate melatonin cytotoxicity by measuring its effects on various cellular targets. Cell viability, intracellular reduced glutathione (GSH) level, and reactive oxygen species (ROS) production were assessed in the human liver cell line (HepG2), after incubation with increasing melatonin concentrations (0.1-10,000 microM). The incubation times tested were 24, 72, and 96 h for cell viability and intracellular GSH level, and 15 and 45 minutes for ROS production. Cellular target evaluations were possible in living cells by means of a new microplate cytofluorimeter. This technology was suitable for the assessment of cell viability, GSH level, and ROS overproduction with, respectively, neutral red, monochlorobimane (mBCl), and 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescent probes. At the lowest melatonin concentrations (0.1-10 microM) and for a relatively short incubation time (24 h), the antioxidant effect of melatonin was revealed by an increased intracellular GSH level, associated to cell viability improvement. In contrast, after longer incubation (96 h), cell viability significantly decreased with these lowest melatonin concentrations (0.1-10 microM). Moreover, high melatonin concentrations (1,000-10,000 microM) induced GSH depletion. This oxidative stress is associated with ROS overproduction from 10 microM after only 15 minutes of incubation. This dual effect is strong evidence that, in vitro, melatonin can be both antioxidant and prooxidant on the human liver cell line, depending on the concentration and incubation time. 相似文献
798.
Robins MJ Doboszewski B Nilsson BL Peterson MA 《Nucleosides, nucleotides & nucleic acids》2000,19(1-2):69-86
We report syntheses of new amide-linked (di-penta)nucleoside analogues of antisense oligonucleotide components. Solution-phase coupling of 3'-(carboxymethyl)-3'-deoxy- and 5'-amino-5'-deoxynucleoside derivatives provides amide dimers. Activated [3'-(carboxymethyl)-3'-deoxy] units with a 5'-azido-5'-deoxy function provide "masked" 5'-amino-5'-deoxy residues for chain extension, and a 5'-O-DMT-protected unit provides the 5'-terminus for attachment to a phosphodiester linkage. 相似文献
799.
Katarzyna Pużyńska Bogdan Kulig Wiktor Halecki Andrzej Lepiarczyk Stanisław Pużyński 《Acta Physiologiae Plantarum》2018,40(9):169
Oilseed rape (Brassica napus L.) reacts differently to foliar application of sulfur (S) and boron (B), and for that reason it is important to find an early indicator that would inform about the direction of this reaction. This study aimed at evaluating the early response of two double-low cultivars of winter oilseed rape: hybrid (Nelson) and open pollinated (Digger) on the foliar fertilization with S and B in two terms: fall and spring, based on the rate of leaf greenness index (SPAD) and seven indicators of chlorophyll a fluorescence (FL). On 7th or 9th day after the application of liquid fertilizers, the selected parameters of FL and SPAD were determined on the leaves of rape. As a result, a significant effect of foliar B and S supplementation on the yield of oilseed rape was found. Principal component analysis (PCA) allowed for a separation for each of the cultivars the two parameters of FL, namely Tfm and Fv/F0, which are sensitive indicators of a physiological state of the rape plants shortly after foliar S and B dressing. 相似文献
800.
Izidor Sosič Ana Mitrović Hrvoje Ćurić Damijan Knez Helena Brodnik Žugelj Bogdan Štefane Janko Kos Stanislav Gobec 《Bioorganic & medicinal chemistry letters》2018,28(7):1239-1247
Human cathepsin B is a cysteine protease with many house-keeping functions, such as intracellular proteolysis within lysosomes. Its increased activity and expression have been strongly associated with many pathological processes, including cancers. We present here the design and synthesis of novel derivatives of nitroxoline as inhibitors of cathepsin B. These were prepared either by omitting the pyridine part, or by modifying positions 2, 7, and 8 of nitroxoline. All compounds were evaluated for their ability to inhibit endopeptidase and exopeptidase activities of cathepsin B. For the most promising inhibitors, the ability to reduce extracellular and intracellular collagen IV degradation was determined, followed by their evaluation in cell-based in vitro models of tumor invasion. The presented data show that we have further defined the structural requirements for cathepsin B inhibition by nitroxoline derivatives and provided additional knowledge that could lead to non-peptidic compounds with usefulness against tumor progression. 相似文献