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61.
Shuso Takeda Masayo Hirao-Suzuki Mitsuru Shindo Hironori Aramaki 《Current issues in molecular biology》2022,44(9):3849
Experimental evidence accumulated by our research group and others strongly suggests that (–)-xanthatin, a xanthanolide sesquiterpene lactone, exhibits anti-proliferative effects on human breast cancer cells (in vitro) as well as anti-tumor effects in experimental animals (in vivo). In cancer biology, it is now critically important for anti-cancer agents to selectively target cancer stem cells (CSCs) in order to overcome cancer therapeutic resistance and recurrence. However, it has not yet been established whether (–)-xanthatin abrogates the formation of breast CSCs. In the present study, we utilized chemically synthesized pure (–)-xanthatin and a culture system to obtain mammospheres from human breast cancer MCF-7 cells, which are a CSC-enriched population. We herein demonstrated for the first time that (–)-xanthatin exhibited the ability to kill mammospheres, similar to salinomycin, an established selective killer of CSCs. A possible anti-proliferative mechanism toward mammospheres by (–)-xanthatin is discussed. 相似文献
62.
Sterigmatocystin (STC) and aflatoxin B1 (AFB1) were analyzed in 246 corn samples, 126 soybean meal samples, and 861 formula feed samples from the Japanese market between April 2010 and March 2015. The detection rate, the highest concentration, and the mean concentration of STC were respectively 14%, 6.4 μg/kg, and 1.2 μg/kg for corn; 14%, 1.1 μg/kg, and 0.63 μg/kg for soybean meal; and 43%, 9.1 μg/kg, and 0.97 μg/kg for formula feed. The detection rate, the highest concentration, and the mean concentration of AFB1 were respectively 46%, 24 μg/kg, and 3.9 μg/kg for corn; 30%, 6.7 μg/kg, and 1.1 μg/kg for soybean meal; and 47%, 20 μg/kg, and 1.6 μg/kg for formula feed. A weak negative correlation between the STC and AFB1 concentrations was observed: there was a high concentration of AFB1 in samples that contained a lower concentration of STC and vice versa. Spearman’s rank correlation coefficient showed a weak negative correlation of ? 0.30 (p < 0.001, n = 128) for corn and ? 0.23 (p < 0.001, n = 575) for formula feed. In conclusion, no correlation was observed between the mean concentrations of STC contamination in formula feed (0.97 μg/kg) and in corn (1.2 μg/kg) and the blending rate (approximately 50%). The rate of STC contamination in the formula feed (43%) was higher than that in corn (14%). Therefore, it is likely that ingredients other than corn contribute to the contamination of formula feed with STC. In this study, regarding STC, problematic samples were not found. 相似文献
63.
Kai Yiu Ting Christina F. P. Leung Richard M. Graeff Hon Cheung Lee Quan Hao Masayo Kotaka 《Protein science : a publication of the Protein Society》2016,25(3):650-661
Cyclic ADP‐ribose (cADPR) mobilizes intracellular Ca2+ stores and activates Ca2+ influx to regulate a wide range of physiological processes. It is one of the products produced from the catalysis of NAD+ by the multifunctional CD38/ADP‐ribosyl cyclase superfamily. After elimination of the nicotinamide ring by the enzyme, the reaction intermediate of NAD+ can either be hydrolyzed to form linear ADPR or cyclized to form cADPR. We have previously shown that human CD38 exhibits a higher preference towards the hydrolysis of NAD+ to form linear ADPR while Aplysia ADP‐ribosyl cyclase prefers cyclizing NAD+ to form cADPR. In this study, we characterized the enzymatic properties of porcine CD38 and revealed that it has a prominent secondary NAD+ cyclase activity producing cADPR. We also determined the X‐ray crystallographic structures of porcine CD38 and were able to observe conformational flexibility at the base of the active site of the enzyme which allow the NAD+ reaction intermediate to adopt conformations resulting in both hydrolysis and cyclization forming linear ADPR and cADPR respectively. 相似文献
64.
Caitlin Kozel Brytteny Thompson Samantha Hustak Chelsea Moore Akio Nakashima Chingakham Ranjit Singh Megan Reid Christian Cox Evangelos Papadopoulos Rafael E. Luna Abbey Anderson Hideaki Tagami Hiroyuki Hiraishi Emily Archer Slone Ken-ichi Yoshino Masayo Asano Sarah Gillaspie Jerome Nietfeld Jean-Pierre Perchellet Stefan Rothenburg Hisao Masai Gerhard Wagner Alexander Beeser Ushio Kikkawa Sherry D. Fleming Katsura Asano 《Nucleic acids research》2016,44(18):8704-8713
65.
A new method is proposed for finding molecular weights from the boundary condition of the ultracentrifuge. The method is more rapid than the conventional Archibald method by at least one order of magnitude and should be especially useful for giant molecules with small diffusion coefficients. It employs a preset concentration gradient. A theoretical study of the method has been made by obtaining solutions to the Lamm equation analogous to the “mirror image” solution (for early times) and the Fourier expansion solution (for late times) of Mason and Weaver. Numerical examples of theoretical results are given, and the errors are discussed. Centrifugation in a preset linear gradient can also be used to reduce the time needed to reach equilibrium. 相似文献
66.
Equipment was devised which permitted the addition of specific gaseous ions to the atmosphere of plastic chambers in which seedlings of HORDEUM VULGARIS were grown in sand culture supplied with chemically defined nutrient solutions. Moderate densities of O2
– or O2
+ ions (1.8×104/cm3)in air containing an added 8% of O2 accelerated the growth rate. A like number of CO2
– or CO2
+ ions in air containing 8% of CO2 inhibited growth, impeded the production of chlorophyll and devitalized the young seedlings. Evidence is presented that O2
– and O2
+ stimulate the production of cytochromes and other Fe-containing enzymes through their action on the plant regulatory system responsible for the control of Fe metabolism. The toxic effect of CO2
– and CO2
+ cannot be explained as yet.
Zusammenfassung Eine Apparatur wurde entwickelt, die die Zufuhr von ionisiertem Gas der AtmosphÄre in Kammern gestattet. Darin wurden Keimlinge von HORDEUM VULGARIS in Sand mit chemisch definierten NÄhrlösungen gezüchtet. Konzentrationen von 1,8×104/cm3 O2 – und O2 + in Luft mit zusÄtzlich 8% O2 beschleunigten die Wachstumsrate. Die gleiche Menge CO2 – und CO2 + in Luft mit zusÄtzlich 8% CO2 hemmte die Wachstumsrate, die Bildung von Chlorophyll und entkrÄftigte die Keimlinge. Es wird gezeigt,dass O2 – und O2 + die Bildung von Cytochrom und anderen eisenhaltigen Enzymen anregen durcn ihre Wirkung auf das den Fe-Stoffwechsel regulierende System der Pflanze. Die toxische Wirkung von CO2 – und CO2 + lÄsst sich noch nicht erklÄren.
Resume On a construit un appareil permettant d'introduire dans 1'atmosphères des ions de gaz déterminés. On a alors effectué de telles adjonctions à l'air contenu dans des cellules de plastique dans lesquelles on cultivait HORDEUM VULGARIS sur du sable et dans une solution nutritive chimiquement définie. Des densités modérées d'ions O2 – ou O2 + (1,8×104/cm3) dans de l'air additionné de 8% d'O2 accélèrent la croissance. La meme concentration de CO2 – et CO2 + additionnée de 8% de CO2 a ralenti la croissance et la formation de chlorophylle et a diminué la vitalite des plantes nouvellement germées. On démontre que O2 – et O2 + active la formation de cytochrome et d'autres enzymes ferreuses par suite de l'action de ces ions sur le système régularisant le métabolisme du fer dans la plante. L'effet toxique du CO2 – et CO2 + reste encore inexpliqué.相似文献
67.
68.
Kouchi Matsumoto Masayo Sakata Masashi Kunitake Masao Miyazakia Chuichi Hirayama 《Biotechnology letters》2002,24(21):1791-1795
Utilizing the rapidity in capturing Salmonella lipopolysaccharide (LPS) and the macroporous nature of poly(ethyleneimine) immobilized polyester cloth (PEI-cloth), a PEI-cloth disk set in a Swinnex cartridge joined at both ends with 10 ml plastic syringes was repeatedly passed through with an LPS sample in large volumes. The captured LPS on the disk were detected at up to 1 pg, which is equivalent to the amount produced of 16 cells, by cloth enzyme immunoassay. 相似文献
69.
70.
Shin-Ichi Seki Hajime Takano Kazuto Kawakami Nobuhiko Kotaka Akira Endo Kenji Takehara 《Conservation Genetics》2007,8(5):1109-1121
The Japanese wood pigeon (Columba janthina) is endemic to the islands of East Asia and it is included in the Japanese and Asian Red Lists because of its narrow habitat
range that is restricted to mature forests on small islands and because of the destruction of these habitats. We examined
the genetic structure of Columba janthina by studying 463 base pairs of the mitochondrial control region sequences. We analyzed 154 samples from eight populations
and identified 27 haplotypes. Three population groups were identified based on the pairwise ΦST values. A substantial gene flow, as reflected by the low and non-significant ΦST values, is maintained among the northern group that includes six populations found on the Okinawa, Tokara, Goto, Setouchi,
Oki, and Izu islands. In contrast, the southeastern group found on the Ogasawara Islands had large ΦST values with every population from other regions (0.910 < ΦST < 0.962). The southwestern group found on the Sakishima Islands also had significant but small ΦST values with every population from the northern group (0.081 < ΦST < 0.205). The Mantel test showed a highly significant correlation between the ΦST values and the route length of the habitat network, as well as the linear distance with correction of the habitat gap effect,
indicating the importance of the closely connected structure of the habitats. The three groups mentioned above could be considered
as independent management units, and the southeastern group has the highest conservation priority due to its narrow distribution
range and small population size.
Electronic Supplementary Material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献