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161.
Nobuhiko Arakawa Choten Inagaki Tomiko Kitamura Sumiko Fujiki Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(7):1445-1447
A two-dimensional mapping analysis was performed by HPLC for 4 kinds of standard galactosyllactoses (GLs, trisaccharide) which were assumed to be produced from lactose (galactopyranosylβ1→4 glucopyranose) in yogurt during the fermentation of lactic acid bacteria. After the pyridylamination of GLs, they were analyzed by HPLC in the reverse-phase (RP) and anion-exchange (AE) modes. The retention times of each peak obtained were converted to glucose units (GU) in RP mode for the pyridylaminated isomaltooligosaccharides (G1-3) and to relative retention time (RRT) in AE mode against pyridylaminated-isomaltotriose, and then the address data [GU, RRT] were plotted on a graph. This two-dimensional mapping method was found useful for a rapid qualitative evaluation of the chemical structure of trisaccharides formed in yogurt. 相似文献
162.
Makoto Watanabe Yu Kamimaki Marino Mori Shigeaki Okabe Izumi Arakawa Yoshiyuki Kinose Satoshi Nakaba Takeshi Izuta 《Journal of plant research》2018,131(6):907-914
Ozone is an air pollutant that negatively affects photosynthesis in woody plants. Previous studies suggested that ozone-induced reduction in photosynthetic rates is mainly attributable to a decrease of maximum carboxylation rate (Vcmax) and/or maximum electron transport rate (Jmax) estimated from response of net photosynthetic rate (A) to intercellular CO2 concentration (Ci) (A/Ci curve) assuming that mesophyll conductance for CO2 diffusion (gm) is infinite. Although it is known that Ci-based Vcmax and Jmax are potentially influenced by gm, its contribution to ozone responses in Ci-based Vcmax and Jmax is still unclear. In the present study, therefore, we analysed photosynthetic processes including gm in leaves of Siebold’s beech (Fagus crenata) seedlings grown under three levels of ozone (charcoal-filtered air or ozone at 1.0- or 1.5-times ambient concentration) for two growing seasons in 2016–2017. Leaf gas exchange and chlorophyll fluorescence were simultaneously measured in July and September of the second growing season. We determined the A, stomatal conductance to water vapor and gm, and analysed A/Ci curve and A/Cc curve (Cc: chloroplast CO2 concentration). We also determined the Rubisco and chlorophyll contents in leaves. In September, ozone significantly decreased Ci-based Vcmax. At the same time, ozone decreased gm, whereas there was no significant effect of ozone on Cc-based Vcmax or the contents of Rubisco and chlorophyll in leaves. These results suggest that ozone-induced reduction in Ci-based Vcmax is a result of the decrease in gm rather than in carboxylation capacity. The decrease in gm by elevated ozone was offset by an increase in Ci, and Cc did not differ depending on ozone treatment. Since Cc-based Vcmax was also similar, A was not changed by elevated ozone. We conclude that gm is an important factor for reduction in Ci-based Vcmax of Siebold’s beech under elevated ozone. 相似文献
163.
Tazro Ohta Takeshi Kawashima Natsuko O. Shinozaki Akito Dobashi Satoshi Hiraoka Tatsuhiko Hoshino Keiichi Kanno Takafumi Kataoka Shuichi Kawashima Motomu Matsui Wataru Nemoto Suguru Nishijima Natsuki Suganuma Haruo Suzuki Y-h. Taguchi Yoichi Takenaka Yosuke Tanigawa Momoka Tsuneyoshi Kazutoshi Yoshitake Yukuto Sato Riu Yamashita Kazuharu Arakawa Wataru Iwasaki 《Journal of plant research》2018,131(4):709-717
Recent studies have shown that environmental DNA is found almost everywhere. Flower petal surfaces are an attractive tissue to use for investigation of the dispersal of environmental DNA in nature as they are isolated from the external environment until the bud opens and only then can the petal surface accumulate environmental DNA. Here, we performed a crowdsourced experiment, the “Ohanami Project”, to obtain environmental DNA samples from petal surfaces of Cerasus?×?yedoensis ‘Somei-yoshino’ across the Japanese archipelago during spring 2015. C. × yedoensis is the most popular garden cherry species in Japan and clones of this cultivar bloom simultaneously every spring. Data collection spanned almost every prefecture and totaled 577 DNA samples from 149 collaborators. Preliminary amplicon-sequencing analysis showed the rapid attachment of environmental DNA onto the petal surfaces. Notably, we found DNA of other common plant species in samples obtained from a wide distribution; this DNA likely originated from the pollen of the Japanese cedar. Our analysis supports our belief that petal surfaces after blossoming are a promising target to reveal the dynamics of environmental DNA in nature. The success of our experiment also shows that crowdsourced environmental DNA analyses have considerable value in ecological studies. 相似文献
164.
Uptake of nitrogen and production of kainic acid by laboratory culture of the red alga Digenea simplex
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Shanshan Jiang Kazuyoshi Kuwano Gregory N. Nishihara Chisato Urata Ryusuke Shimoda Tomohiro Takatani Osamu Arakawa 《Phycological Research》2018,66(1):68-75
The red alga Digenea simplex was cultured with various culture media to clarify the nutritional conditions to produce kainic acid (KA ). Unlike the domoic acid‐producing red alga Chondria armata , D. simplex was insensitive to excessive manganese, and grew best (mean growth rate approximately 800% for 25 days) in modified PES medium (mPES ; seawater + nitrate, phosphate, iron, trace metals, vitamins, and 2‐[4‐(2‐hydroxyethyl)‐1‐piperazinyl]‐ ethanesulfonic acid) prepared with autoclaved seawater. Liquid chromatography‐mass spectrometry analysis of the algal extracts revealed that the KA content of the explants cultured with mPES or N·P·Fe medium (seawater + nitrate, phosphate, and iron) was somewhat higher than that of wild specimens (1748–2378 μg g?1 vs 1562 μg g?1). The 1H‐nuclear magnetic resonance spectrum of the KA extracted and purified from pooled explants was indistinguishable from the previously reported KA spectrum. When D. simplex was cultured for 6 weeks with medium in which NaNO 3 of mPES was replaced by Na15NO 3, the ratio of 214KA to total measured KA (totalKA = 213KA + 214KA ) in the cultured explants (0.1 at the beginning of culture) gradually increased to 2.5, indicating that D. simplex produces KA in proportion to its growth under the condition in which sufficient nitrogen source is available. 相似文献
165.
We experimented with vein grafting surgery on G?ttingen minipigs. Using the internal jugular vein for the tissue graft, we performed side-to-side anastomosis to the carotid artery, to which it runs parallel. One key point in this surgery was to prevent vasospasm of the carotid artery so as to keep the lumen sufficiently patent during anastomosis. The histopathological findings in the grafts which remained patent resembled those of vein grafts in humans. We therefore considered that this technique in minipigs can be applied for the study of coronary artery bypass surgery in humans. 相似文献
166.
Effective methods to inactivate or remove budded particles of a nuclear polyhedrosis virus of Bombyx mori (BmNPV) from a cell-cultured media or from host haemolymph that is infected by this virus have been developed. Two types of suspensions containing BmNPV budded virus particles, TC-100 media that cultured BmN4 cells infected by this virus and haemolymph of B. mori larvae infected by this virus, were treated by 6% (w/v) polyethylene glycol (PEG), 0.01% (w/v) chitosan, 0.05% (v/v) linoleic acid (an emulsion), and/or diethylether. Treatment by linoleic acid followed by PEG-precipitation and treatment by diethylether followed by PEG-precipitation were so effective that these treatments suppressed the viral titre of BmNPV-infected larval haemolymph from an original titre (> 109 TCID50 units/ml) to below a detectable limit. These methods are suggested as being potentially useful in an insect factory system; that is, a protein production system utilizing a baculovirus vector and its insect host or cultured cells on a large scale. 相似文献
167.
T Agatsuma Y Arakawa M Iwagami Y Honzako U Cahyaningsih S Y Kang S J Hong 《Parasitology international》2000,49(3):231-238
Nucleotide sequences of two regions, cytochrome c-oxidase subunit 1 (CO1) and NADH dehydrogenase subunit 1 (ND1) of the mitochondrial DNA and two regions, internal-transcribed spacer 2 (ITS2) and the D2 region in the 28S rDNA (28S) of the nuclear DNA were obtained from five Korean worms of the genus Fasciola in order to elucidate their taxonomic status. The CO1 and ND1 regions are all monomorphic in the Korean worms and similar to those of F. gigantica. On the other hand, the ITS2 and D2 regions were found to be polymorphic; that is, out of five worms, two possessed a F. gigantica-type sequence, one, a F. hepatica-type sequence and two possessed sequences of both types indicating an existence of different alleles at the loci. It should be noted that these variations of the ITS2 and D2 regions co-occur at the same individual worms. This was confirmed by sequencing five to six cloned PCR products for each worm. The present study strongly suggests interspecific cross-hybridization between the two species coexisting in Korea. 相似文献
168.
T. Arakawa S. Tomita M. Miyazawa M. Kiuchi M. Kato 《Journal of Applied Entomology》1999,123(7):443-446
Insect haemolymph contains growth promotor(s) for cultured insect cells and is frequently used as an additive to the culture media. Insect haemolymph serves as a pool of a protein product produced by a virus vector–insect host system. Haemolymph collection is an essential step in the above process, which should limit the scale and cost of their performance. In the present study, a simple procedure for bleeding from lepidopteran larvae, Bombyx mori , has been developed which utilized a spontaneous contraction of the insect body after a freezing–thawing treatment. In the case of fifth-instar B. mori , 60 to 80% of the total haemolymph was collected by this method. The authors applied the method to a haemolymph collection from frozen larvae stored at −80°C for longer than 1 month. Preservability of the frozen larvae enabled the development of a system dealing with a huge bulk of insects. The bleeding method was effective under cooled condition at 0°C or 4°C, which was desired for protein handling. Development of a large system would result in a cost reduction for the insect haemolymph products such as insect cell-culture additive. Furthermore, the above bleeding method was applied to the nuclear polyhedrosis virus-infected B. mori larvae and up to 80% of the total haemolymph was collected from the virus-infected larvae. It suggests the bleeding method as an effective means of haemolymph collection in the protein productive system using a virus vector and its insect host. 相似文献
169.
Kazunori Yamamoto Ritsuko Murakami Yoshichika Takamura 《FEMS microbiology letters》1998,161(2):351-358
The configuration of quinone systems, cellular fatty acids and diaminopimelic acids in 11 species of thermophilic clostridia which have been classified into new genera based on their 16S rRNA sequences was determined. It was found that menaquinone 7 was present in 10 species as the major component of menaquinone systems by analyses using HPLC with photodiode-array detector and electron impact mass spectrometry. In seven of the 11 species, the major cellular fatty acids were determined to be iso-15:0 and iso-17:0. As a results of chemotaxonomic studies it was demonstrated that the representatives of the new genera Thermoanaerobacter and Thermoanaerobacterium were heterogeneous in their chemical composition, whereas strains of the new genus Moorella and of the new unnamed genus which is composed of (Clostridium) stercorarium and (Clostridium) thermolacticum showed homogeneity in their chemotaxonomic characteristics. 相似文献
170.
Synergistic antitumor effects of interleukin-12 gene transfer and systemic administration of interleukin-18 in a mouse bladder cancer model 总被引:2,自引:0,他引:2
Kazuki Yamanaka Isao Hara Hiroshi Nagai Hideaki Miyake Kazuo Gohji Mark J. Micallef Masashi Kurimoto Soichi Arakawa Sadao Kamidono 《Cancer immunology, immunotherapy : CII》1999,48(6):297-302
We introduced the interleukin-12 (IL-12) gene into the mouse bladder cancer cell line (MBT2) to establish sublines that secrete
bioactive IL-12. IL-12-secreting MBT2 (MBT2/IL-12) sublines were completely rejected when subcutaneously implanted into immunocompetent
syngeneic C3H mice. Although this antitumor effect did not change when IL-12-secreting cells were injected into immunodeficient
mice whose CD8+ T or CD4+ T cells had been depleted by the corresponding antibody, it was abrogated when natural killer cells were depleted by anti-asialoGM1
antibody. In addition, when parental MBT2 cells mixed with MBT2/IL-12 cells were subcutaneously injected into mice, admixed
MBT2/IL-12 inhibited the growth of the parental tumor. Furthermore, this antitumor effect was enhanced by systemic IL-18 administration.
This synergism was abrogated when the mice were treated with interferon-γ-neutralizing antibody in vivo. In conclusion, local
secretion of IL-12 led to effective antitumor activity that was enhanced by systemic administration of IL-18. Interferon-γ
plays an important role in the synergism of IL-12 gene transduction and systemic administration of IL-18.
Received: 7 May 1998 / Accepted: 27 May 1999 相似文献