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1.
Bloom's syndrome. III. Analysis of the chromosome aberration characteristic of this disorder 总被引:14,自引:0,他引:14
The following hypothesis is put forward: X chromatin in man condenses around a center which is situated on Xq at a short distance from the centromere. The hypothesis is based on, and explains, two classes of observations. (1) Abnormal X chromosomes that have the assumed center in duplicate form bipartite Barr bodies in part of the cells. The frequency of bipartite bodies and the distance between the two parts seem to be determined by the distance between the postulated centers. (2) A large number of variously abnormal X chromosomes have been described. Almost all of them possess the postulated center and it seems possible that the very few apparent exceptions represent misidentifications of chromosome Xq — as isochromosome i(Xp). According to the hypothesis, chromosomes lacking the center would form no Barr body and therefore presumably would not be inactivated, thus leaving the cell severely unbalanced. Furthermore, absence of the center might interfere with the viability of the chromosome itself. 相似文献
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Seyede Saba Hosseini Seyed Omar Ebrahimi Maryam Haji Ghasem Kashani Somayeh Reiisi 《Cell biology international》2023,47(1):98-109
Naturally-derived drugs have drawn much attention in recent decades. Efficiency, lower toxicity, and economic reasons are some of their advantages that justify this broad range of administration for different diseases, including cancer. If we can find a specific combination that boosts the effects of their single therapy, leading to synergism effect, increased efficiency, and decreased toxicity, they can act even better. Quercetin and fisetin, two well-known flavonoids, have been used to fight against various cancers. In this study, we investigated their possible synergism quercetin and fisetin on MCF7, MDA-MB-231, BT549, T47D, and 4T1 breast cancer cell lines. Then the optimum combined dose was used to study their impacts on wound healing abilities and clonogenic properties. The real-time qPCR was used to study the expression of their validated downstream effectors in predicted pathways. A significant synergism effect (p < .01, combination index: <1) was observed for all cell lines. Combination therapy was significantly more effective in colony formation (p < .0001) and wound healing assays (p < .001) compared to single therapies. The expression level of potential effectors was also showed a greater change. In vivo study confirmed the in vitro results and showed how significantly (p < .001) their synergism promotes their singular function in inhibiting cancer progression. The breast cancer mouse models receiving combined therapy lived longer with higher average body weight and smaller tumor sizes. These results exhibit that quercetin and fisetin inhibit cancer cell proliferation, migration and colony formation synergistically, and matrix metalloproteinase signaling and apoptotic pathways are relatively responsible for inhibitory activities. 相似文献
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Sophie L. Richards Harith Farooq Hermenegildo Matimele Tereza Alves Castigo Datizua Clayton Langa Alice Massingue Jo Osborne Saba Rokni Camila de Sousa Iain Darbyshire 《Biotropica》2023,55(6):1183-1194
Successful protected area networks must represent biodiversity across taxonomic groups. However, too often plant species are overlooked in conservation planning, and the resulting protected areas may, as a result, fail to encompass the most important sites for plant diversity. The Mozambique Tropical Important Plant Areas project sought to promote the conservation of Mozambique's flora through the identification of Important Plant Areas (IPAs). Here, we use the Weighted Endemism including Global Endangerment (WEGE) index to identify the richest areas for rare and endemic plants in Mozambique and subsequently evaluate how well represented these hotspots are within the current protected area and IPA networks. We also examine the congruence between IPA and protected areas to identify opportunities for strengthening the conservation of plants in Mozambique. We found that high WEGE scores, representing areas rich in endemic/near-endemic and threatened species, predict the presence of IPAs in Mozambique, but do not predict the presence of protected areas. We also find that there is limited overlap between IPAs and protected areas in Mozambique. We demonstrate how IPAs could be an important tool for ensuring priority sites for plant diversity are included within protected area network expansions, particularly following the adoption of the “30 by 30” target agreed within the post-2020 Convention on Biological Diversity framework, with great potential for this method to be replicated elsewhere in the global tropics. 相似文献
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Pierluigi Gariboldi Francesca Pelizzoni Marco Tat Luisella Verotta Nadia El-Sebakhy Aya M. Asaad Rokia M. Abdallah Soad M. Toaima 《Phytochemistry》1995,40(6):1755-1760
Three new cycloartane glycosides, trigonoside I, II and III, and the known astragalosides I and II were isolated from the roots of Astragalus trigonus. The structures of the new glycosides were totally elucidated by high field (600 MHz) NMR analyses as cycloastragenol-6-O-β-xylopyranoside, cycloastragenol-3-O-[-l-arabinopyranosyl(1 → 2)-β-d-xylopyranosyl]-6-O-β- d-xylopyranoside and cycloastragenol-3-O-[-l-arabinopyranosyl(1 → 2)-β-d-(3-O-acetyl)-xylopyranosyl]-6-O-β-d-xylopyranoside. 相似文献
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Richard B. Forward Jr Elizabeth Freeman Kristen Gall Katie Saba 《Marine and Freshwater Behaviour and Physiology》2013,45(5):305-319
The supratidal amphipod Talorchestia longicornis Say has a circadian rhythm in activity, in which it is active on the substrate surface at night and inactive in burrows during the day. The present study determined: (1) the circadian rhythms in individual versus groups of amphipods; (2) the range of temperature cycles that entrain the circadian rhythm; (3) entrainment by high-temperature cycles versus light?:?dark cycles, and (4) seasonal substrate temperature cycles. The circadian rhythm was determined by monitoring temporal changes in surface activity using a video system. Individual and groups of amphipods have similar circadian rhythms. Entrainment occurred only to temperature cycles that included temperatures below 20°C (10–20, 15–20, 17–19, 15–25°C) but not to temperatures above 20°C (20–25, 20–30°C), and required only a 2°C temperature cycle (17–19°C). Diel substrate temperatures were above 20°C in the summer and below 20°C during the winter. Upon simultaneous exposure to a diel high-temperature cycle (20–30°C) and a light?:?dark cycle phased differently, amphipods entrained to the light?:?dark cycle. Past studies found that a temperature cycle below 20°C overrode the light?:?dark cycle for entrainment. The functional significance of this change in entrainment cues may be that while buried during the winter, the activity rhythm remains in phase with the day?:?night cycle by the substrate temperature cycles. During the summer, T. longicornis switches to the light?:?dark cycle for entrainment, perhaps as a mechanism to phase activity precisely to the short summer nights. 相似文献
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Sharma Himanshu Bhandawat Abhishek Rahim Mohammed Saba Kumar Pankaj Choudhoury Mohini Pal Roy Joy 《Molecular biology reports》2020,47(5):3485-3500
Molecular Biology Reports - Introns experience lesser selection pressure, thus are liable for higher polymorphism. Intron Length Polymorphic (ILP) markers designed from exon-flanking introns... 相似文献