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941.
El Sabeh Malak Saha Subbroto Kumar Afrin Sadia Islam Md Soriful Borahay Mostafa A. 《Molecular and cellular biochemistry》2021,476(9):3513-3536
Molecular and Cellular Biochemistry - Uterine leiomyoma is the most common tumor of the female reproductive system and originates from a single transformed myometrial smooth muscle cell. Despite... 相似文献
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Purushotham Vemishetti Hussein I. El Subbagh Elie Abushanab and Raymond P. Panzica 《Nucleosides, nucleotides & nucleic acids》2013,32(2-4):739-748
Abstract 1′,2′-Seco-AZT (3) and its 3′R,4′S diastereomer (19) were prepared and evaluated as antiviral agents. The chiral, acyclic side chains of these thymine acyclonuleosides were derived from D-isoascorbic acid. The two AZT analogues, 3 and 19, were screened against HIV, other RNA viruses, and two DNA viruses and they were found to be inactive. 相似文献
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In common cypress, Cupressus sempervirens L., the megagametophyte persists in mature seeds as a polyploid endosperm containing cells with even and odd series of DNA
contents: 1C, 2C, 3C, 4C, 5C etc., where C is the amount of DNA in the haploid genome. In this study, cytometrical, histological
and cytochemical investigations were performed in order to determine the behavior of megagametophyte nuclei during the reproductive
cycle. Unexpected nuclear alterations due to a continuous process of nuclear fusion were observed in the megagametophyte,
leading to polyploidization and consequently to intense food-reserve synthesis. During the free nuclear stage, the megagametophyte
exhibited only sporadic nuclear fusion and limited food-reserve production. When cellularization took place, multinucleated
compartments were observed in which nuclei fused, producing odd and even series of DNA contents as proved by flow-cytometric
analysis. This polyploidization process considerably increased after fertilization and during embryo development, and was
accompanied by increased food-reserve synthesis. During these later stages, fusion mainly involved nuclei of contiguous cells
and was preceded by the disintegration of their adjacent walls. Mitoses with incomplete phragmoplast differentiation were
also observed to yield polyploid nuclei. Finally, in mature seeds the endosperm still exhibited multinucleate cells and fusion
nuclei, and contained high amounts of storage products. The results are interpreted as an alteration of DNA contents in the
megagametophyte cells in relation to specific metabolic activity during seed development.
Received: 2 September 1998 / Accepted: 31 December 1998 相似文献
948.
Salwa A. Maksoud M. Nabil El Hadidi Wafaa Mahrous Amer 《Vegetation History and Archaeobotany》1994,3(4):219-224
Physical and chemical analyses of beer residues recovered from a vat site at Hierakonpolis (Upper Egypt) were carried out. Radiocarbon dates of the residues suggest a dating of 3500–3400 cal B.C. and are believed to represent the oldest known beer in the world. Macroscopic and microscopic examinations of the residues revealed the presence of intact remains of grains and spikelets of wheat and barley, as well as fragments of dates and grape pips. Chemical analyses included percentages of sample ingredients, pH and total soluble ions, quantitative determinations of sugars, carboxylic acids and free amino acids. A total of 25 compounds were identified, which are components of fermentation processes that are believed to have formed in connection with the preparation of what is called Nekhen-Hoffman beer. 相似文献
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Elżbieta Boratyn Iwona Nowak Elżbieta Karnas Damian Ryszawy Dawid Wnuk Anna Polus Małgorzata Durbas Irena Horwacik Hanna Rokita 《Journal of cellular biochemistry》2020,121(5-6):3406-3425
Monocyte chemoattractant protein-1-induced protein 1 (MCPIP1) has a multidomain structure, which assures its pleiotropic activity. The physiological functions of this protein include repression of inflammatory processes and the prevention of immune disorders. The influence of MCPIP1 on the cell cycle of cancer cells has not been sufficiently elucidated. A previous study by our group reported that overexpression of MCPIP1 affects the cell viability, inhibits the activation of the phosphoinositide-3 kinase/mammalian target of rapamycin signalling pathway, and reduces the stability of the MYCN oncogene in neuroblastoma (NB) cells. Furthermore, a decrease in expression and phosphorylation levels of cyclin-dependent kinase (CDK) 1, which has a key role in the M phase of the cell cycle, was observed. On the basis of these previous results, the purpose of our present study was to elucidate the influence of MCPIP1 on the cell cycle of NB cells. It was confirmed that ectopic overexpression of MCPIP1 in two human NB cell lines, KELLY and BE(2)-C, inhibited cell proliferation. Furthermore, flow cytometric analyses and imaging of the cell cycle with a fluorescence ubiquitination cell-cycle indicator test, demonstrated that overexpression of MCPIP1 causes an accumulation of NB cells in the G1 phase of the cell cycle, while the possibility of an increase in G0 phase due to induction of quiescence or senescence was excluded. Additional assessment of the molecular machinery responsible for the transition between the cell-cycle phases confirmed that MCPIP1 overexpression reduced the expression of cyclins A2, B1, D1, D3, E1, and E2 and decreased the phosphorylation of CDK2 and CDK4, as well as retinoblastoma protein. In conclusion, the present results indicated a relevant impact of overexpression of MCPIP1 on the cell cycle, namely a block of the G1/S cell-cycle checkpoint, resulting in arrest of NB cells in the G1 phase. 相似文献