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931.
Kazumasa Hirata Misuzu Mukai Saeko Goda Masumi Ishio-Kinugasa Kenji Yoshida Akira Sakai Kazuhisa Miyamoto 《Biotechnology letters》2002,24(5):371-376
Hairy root cultures of Vinca minor and Ajuga reptans var. atropurpurea could be cryopreserved when the roots were precultured and encapsulated in 2% (w/v) alginate beads with 0.3 M sucrose and 0.5 M glycerol and dehydrated until the bead weight reached 25% of the initial weight before cooling in liquid nitrogen. Preculture and encapsulation of the roots with abscisic acid was effective in increasing the survival rates. For V. minor root tips moreover a sufficiently high survival rate of more than 70% was attained by eliminating glycerol from the preculture medium and dehydration of beads until 23% of the initial weight was reached instead of 25%. 相似文献
932.
Jin Konishi Hideki Okada Kazuaki Hirasawa Yoshitaka Ishii Kenji Maruhashi 《Biotechnology letters》2002,24(22):1863-1867
Using cell-free extracts of a desulfurizing mesophile, Rhodococcus erythropolis KA2-5-1 (the Dsz system) and Escherichia coli JM109, which possesses the desulfurizing genes of a thermophile Paenibacillus sp. A11-2 (the Tds system), the reactivity of desulfurizing enzymes toward 4,6-dialkyl dibenzothiophenes (4,6-dialkyl DBTs) and 7-alkyl benzothiophenes (7-alkyl BTs) was investigated. Both systems desulfurized all the 4,6-dialkyl DBTs, except 4,6-dibutyl DBT. Although some alkylated BTs were degraded by the Dsz system, no desulfurized compounds were detected. The reactivity of the Tds system toward alkylated BTs was higher than that of DBT. In contrast to the Dsz system, the Tds system yielded desulfurized compounds from all of the alkylated BTs examined. 相似文献
933.
Masanobu Hayashi Tomoko Kuge Daiji Endoh Kenji Nakayama Jiro Arikawa Akira Takazawa Toyo Okui 《Experimental Animals》2002,51(1):43-48
Effects of accumulation of copper and iron on induction of DNA strand breaks were investigated in Long-Evans Cinnamon (LEC) rats that spontaneously develop fulminant hepatitis. Copper and iron accumulated in the liver of LEC rats in an age-dependent manner from 4 to 15 weeks. Low-iron diet prevented the accumulation of iron in the liver, but did not prevent accumulation of copper. The amounts of DNA strand breaks that were estimated by comet assay in the liver cells of rats fed standard diet increased with age from 4 to 15 weeks. No significant differences were observed in the proportions of LEC rat liver cells without tail and the average lengths of tail momentum in the comet images between LEC rats that had been fed standard MF diet and low-iron diet. These results support the idea that accumulation of iron is not directly associated with the induction of DNA damage in the liver cells of LEC rats. 相似文献
934.
Stomach contents of 75 specimens of the cornetfish Fistularia commersonii, collected in shallow water off Kuchinoerabu-jima Island, southern Japan were analyzed. Many fish contained multiple prey.
The prey were mostly fish, grouped into two types, pelagic and reef fishes. The size of prey increased as the size of F. commersonii increased. All the small individuals (<50 cm SL) had fed on only small reef fish. However, most of the large individuals
(>50 cm SL) had fed on either prey type. Both pelagic and reef fishes usually occurred simultaneously in shallow water, suggesting
that most of the large cornetfish may selectively hunt either type of prey.
Received: February 27, 2001 / Revised: September 11, 2001 / Accepted: October 10, 2001 相似文献
935.
Several patterns of feeding behaviors have been documented in benthophagous fishes. The foraging behavior of the maiden goby,
Pterogobius virgo, was studied at Kurahashi Island in the Seto Inland Sea, Japan. Pterogobius virgo foraged mostly on polychaetes by volume from among several available prey items by digging in the sandy bottom. The digging
behavior comprised swing of only pectoral fins or of both pectoral fins and body. Pectoral fin swing exposed the cryptic prey
within the bottom, and fins and body swing exposed the prey and washed the sediment away. The swings were repeatedly and continuously
conducted at a site during the daytime, making a pit several centimeters deep in which the fish was located. After the prey
was exposed, the fish immediately and rapidly picked up the prey. Polychaetes were abundant prey in the sediment, occurring
in the layer 3–5 cm deep from the bottom surface in the study area. In this goby, spot-fixed fin digging, the first documentation
of feeding habits in gobies, may be effective for feeding on the most valuable prey, i.e., polychaetes, which may be otherwise
unavailable for this fish.
Received: April 24, 2001 / Revised: April 26, 2002 / Accepted: May 7, 2002 相似文献
936.
Atsuko Matsuoka Kenji Takeshita Ayumi Furuta Masayasu Ozaki Kiyoshi Fukuhara Naoki Miyata 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2002,521(1-2):29-35
We previously reported that 3,5,4′-trihydroxy-trans-stilbene (resveratrol), a polyphenolic phytoalexin found in grapes, induces a high frequency of sister chromatid exchanges (SCEs) in vitro. In this study, to investigate structure activity relationships, we synthesized six analogues of resveratrol differing in number and position of hydroxy groups, and we investigated their activity in chromosomal aberration (CA), micronucleus (MN) and sister chromatid exchange (SCE) tests in a Chinese hamster cell line (CHL). Two of the six analogues (3,4′-dihydroxy-trans-stilbene and 4-hydroxy-trans-stilbene) showed clear positive responses in a concentration-dependent manner in all three tests. Both were equal to or stronger than resveratrol in genotoxicity. The 4′-hydroxy (OH) analogue had the simplest chemical structure and was the most genotoxic. The other analogues did not have a 4′-hydroxy group. These results suggested that a 4′-hydroxy group is essential to the genotoxicity of stilbenes. 相似文献
937.
938.
Kenji Miyake Hidenori Tachida Yuji Oshima Ryoichi Arai Seirô Kimura Nobuyoshi Imada Tsuneo Honjo 《Ichthyological Research》2001,48(2):105-110
According to conventional views, the rosy bitterling, Rhodeus ocellatus, comprises two subspecies, R. ocellatus kurumeus and R. ocellatus ocellatus, the former being native to Japan whereas the latter was introduced into Japan from China during World War II. To examine
the genetic structure of Japanese R. ocellatus, part of the mitochondrial cytochrome b gene from 48 individuals collected from various locations in Japan was sequenced. Three major mitochondrial lineages were
found. Based on historical evidence, two of these represent R. ocellatus ocellatus and the third R. ocellatus kurumeus. The existence of two distinct lineages of R. ocellatus ocellatus in Japan suggests at least two colonizations. Some local populations comprised purely R. ocellatus kurumeus, but those from Kashima and Ogori included both subspecies. Because the proportion of R. ocellatus ocellatus in Kashima increased from 1994 to 1995, invasion by R. ocellatus ocellatus into R. ocellatus kurumeus habitats is apparently in progress.
Received: April 30, 1999 / Revised: March 22, 2000 / Accepted: December 20, 2000 相似文献
939.
Menadione-catalyzed H2O2 production by viable animal cells was proportional to the viable cell number, and H2O2 production decreased with increasing cytotoxic effects after the incubation of cells with cytotoxic compounds. The cytotoxic
effects of food additives, pesticides, antibiotics, heavy metals, phytotoxins, mycotoxins, and marine toxins were estimated
using the above test employingNIH/3T3 and Neuro-2a cells. Synergistic effects of the toxin mixture were observed and acute
cytotoxicity detected 1 h after the incubation of cells with toxins. This menadione-catalyzed H2O2production assay is rapid and simple compared to other popular cytotoxicity tests such as the MTT reduction assay and Neutral
red inclusion test, requiring4 h. The menadione-catalyzed H2O2 production assay is expected to be a useful food safety test for rapidly detecting toxic compounds having a basic cytotoxic
effect on common animal cells.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
940.
Takumi Higaki Natsumaro Kutsuna Kae Akita Hisako Takigawa-Imamura Kenji Yoshimura Takashi Miura 《PLoS computational biology》2016,12(4)
Plant leaf epidermal cells exhibit a jigsaw puzzle–like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo. 相似文献