Formation of optically active neolignans from achiral coniferyl alcohol by cell-free extracts of Eucommia ulmoides     

Takeshi Katayama  Yuki Kado 《Journal of Wood Science》1998,44(3):244-246

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Delignification of cell walls of <Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis> during alkaline nitrobenzene oxidation     

Arata?YoshinagaEmail author  Seizo?Ohno  Minoru?Fujita 《Journal of Wood Science》2004,50(4):287-294

To clarify the behavior of whole lignins in wood cell walls during alkaline nitrobenzene oxidation, the delignification process from cell walls in normal and compression woods of Chamaecyparis obtusa Endl. (Cupressaceae) was observed using ultraviolet and transmission electron microscopies. The lignin content conspicuously decreased to around 10% after 35min in normal wood. The lignin content in compression wood finally leveled off at aroumd 10% after 50min. In gel filtration of oxidation products in ethyl acetate, a high molecular weight fraction was prominent in extracts from the early stage of the reaction. As the oxidation progressed, the high molecular weight fraction became less prominent in both normal and compression wood. Changes in the weights of cell wall residues during reaction indicated that approximately half of the components other than lignin were also removed from the cell walls. This shows that the majority of lignin with relatively high molecular weight is removed from the cell walls together with polysaccharides in the early stage of the reaction and that further oxidative degradation occurs in solution in later stages. Only a small amount of the lignin with low molecular weight could be analyzed by gas chromatography.Parts of this report were presented at the 47th (Kochi, April 1997) and 48th (Shizuoka, April 1998) Annual Meetings of the Japan Wood Research Society, and at the Lignin Symposium, Sapporo, October 1997  相似文献   

New approaches to wood bonding A base-activated lignin adhesive system     

R. A. Young  M. Fujita  B. H. River 《Wood Science and Technology》1985,19(4):363-381

Current knowledge of wood surface characteristics and surface modification are briefly reviewed and the postulated effects of chemical activation are summarized. It was found that aqueous sodium hydroxide can effectively activate wood surfaces to give strong dry autohesive bonds, but only low wet strength was obtained. However, excellent dry and wet wood bond strengths, equivalent to phenol-formaldehyde bonded samples, were obtained when methylolated lignin was used in combination with 3N sodium hydroxide activation. Several mechanisms of base activation are suggested, including enhanced wood surface contact and reactivity.  相似文献   

Parathyroid hormone‐related protein‐induced hypercalcemia due to osteosarcoma in a cat          下载免费PDF全文

Masashi Yuki  Makiko Nitta  Tetsuo Omachi 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2015,44(1):141-144

A 15‐year‐old castrated male mixed‐breed cat was presented with a history of sarcoma of the distal right hind limb. Biochemical analysis revealed increased concentrations of blood urea, creatinine, total calcium, ionized calcium, and parathyroid hormone‐related protein (PTHrP). The mass was removed surgically by amputation of the hind limb. Osteosarcoma was diagnosed based on histopathologic examination. All abnormal serum analyte concentrations improved immediately after surgery, including azotemia, total calcium, ionized calcium, and PTHrP. The biochemical results were attributed to osteosarcoma causing PTHrP‐induced hypercalcemia.  相似文献   

Time course of the incidence/multiplicity and histopathological features of murine colonic dysplasia,adenoma and adenocarcinoma induced by benzo[a]pyrene and dextran sulfate sodium     

Jiro Sonoda  Yuki Seki  Atsushi Hakura  Satoru Hosokawa 《Journal of toxicologic pathology》2015,28(2):109-120

Benzo[a]pyrene (BP) is mutagenic but noncarcinogenic in the murine colon. Recently, we reported rapid induction of colonic tumors by treatment of CD2F₁ mice with BP (125 mg/kg for 5 days) followed by a colitis inducer, dextran sulfate sodium (DSS) (4% in drinking water for 1 or 2 weeks). However, there are no reports on detailed time course and histopathological features of colonic proliferative lesions in this model. Here, we show the detailed time course of colonic dysplasia, adenoma and adenocarcinoma induced by treatment with BP, DSS, and a combination of the two (BP/DSS). In the colon of mice exposed to BP/DSS, 14.6 dysplastic foci per mouse were present one week after DSS treatment (week 4). The number of dysplastic foci decreased with time to 3.1 at week 9 and thereafter remained almost constant. At week 4, 1.5 adenocarcinomas were also observed, with a marked increase in numbers with time, reaching 29.3 at week 14. In contrast, the number of dysplastic foci induced by DSS alone showed a time course similar to that following BP/DSS treatment; however, only a few tumors appeared. Neither dysplastic foci nor neoplastic lesions were induced by BP only. In mice exposed to BP/DSS, β-catenin was demonstrated immunohistochemically in the nucleus and/or cytoplasm of the tumor cells, and this translocation from the cell membrane was evident in subsets of dysplastic foci. In dysplastic foci induced by DSS alone, β-catenin was absent in the nucleus/cytoplasm. These finding suggest that aberrant β-catenin accumulation in dysplastic foci is associated with tumor progression in this BP/DSS model.  相似文献   

Comparison of the canine corneal epithelial cell sheets cultivated from limbal stem cells on canine amniotic membrane,atelocollagen gel,and temperature‐responsive culture dish          下载免费PDF全文

Eunryel Nam  Naoki Fujita  Maresuke Morita  Keiko Tsuzuki  Hsing Yi Lin  Cheng Shu Chung  Takayuki Nakagawa  Ryohei Nishimura 《Veterinary ophthalmology》2015,18(4):317-325

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Reddish coloration of Chinese quince (Pseudocydonia sinensis) procyanidins during heat treatment and effect on antioxidant and antiinfluenza viral activities     

Hamauzu Y  Kume C  Yasui H  Fujita T 《Journal of agricultural and food chemistry》2007,55(4):1221-1226

To investigate the effects of processing Chinese quince fruit on the denaturation of phenolics and their food functions, fruit phenolic extracts were heated together with organic acid for up to 12 h. Chinese quince phenolic (mostly procyanidins) solution subjected to heat treatment changed from almost colorless, pale yellow, to a reddish color. Before heat treatment, the absorption spectra of polymeric procyanidins were observed only around 280 nm; after heat treatment, absorption occurred between 400 and 600 nm, which is related to the reddish color appearance. Thioacidolysis of denatured reddish phenolics showed that (-)-epicatechin subunits decreased during heat treatment and, in contrast, cyanidin increased. In addition, novel substances that could not be degraded by thioacidolysis were formed. Meanwhile, antioxidant activities, assessed by linoleic acid peroxidation, 1,1-diphenyl-2-picrylhydrazyl (DPPH), Folin-Ciocalteu, and FRAP methods, increased during heat treatment. The antiinfluenza viral activity of denatured reddish phenolics was inferior to that of intact fruit phenolics; however, they retained moderate activity. These results indicate that red coloration of fruit products of Chinese quince was mainly due to the spectral (i.e. structural) changes of procyanidins accompanied with formation of cyanidin. Increasing the length of heat treatment increased the antioxidant capacity of phenolics, and the resultant reddish phenolics retained moderate antiinfluenza viral activity.  相似文献   

Thermal behavior of beta-1 subunits in lignin: pyrolysis of 1,2-diarylpropane-1,3-diol-type lignin model compounds     

Kuroda K  Ashitani T  Fujita K  Hattori T 《Journal of agricultural and food chemistry》2007,55(8):2770-2778

1,2-Diarylpropane-1,3-diol-type lignin model compounds, 1,2-bis(4-hydroxy-3-methoxyphenyl)propane-1,3-diol (1) and 1-(3,4-diethoxyphenyl)-2-(4-methoxyphenyl)propane-1,3-diol (2), were pyrolyzed at 500 degrees C for 4 s to clarify the thermal behavior of beta-1 subunits in lignin. Products were monitored by gas chromatography/mass spectrometry. The cleavage of the Calpha-Cbeta bond to produce benzaldehydes such as 4-hydroxy-3-methoxybenzaldehyde (9) and phenylethanals as the counterparts such as 4-hydroxy-3-methoxyphenylethanal (10) occurred in pyrolyses of both 1 and 2. In pyrolysis of 1, an oxetane pathway leading to the formation of Z/E-stilbenes without the gamma-CH2OH group such as Z/E-4,4'-dihydroxy-3,3'-dimethoxystilbene (3) was predominant. In pyrolysis of 2, the oxetane pathway was minor, while pathways producing a dimer with a =CgammaH2 group by loss of water and a dimer with an alpha-carbonyl group were predominant. Pyrolysis of Japanese cedar wood provided 3 and 10 in approximately 0.8% and 0.6% yields, respectively, based on the Klason lignin content, while pyrolysis of a guaiacyl bulk dehydrogenation polymer gave them in a very small amount.  相似文献   

Bioavailability of amino acid-chelated and glass-embedded manganese to rainbow trout, Oncorhynchus mykiss (Walbaum), fingerlings     

S Satoh  M J Apines  T Tsukioka  V Kiron  T Watanabe  & S Fujita 《Aquaculture Research》2001,32(S1):18-25

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Purified Culture Systems for Bovine Oviductal Stromal Cells     

Yuki YAMAMOTO  Yoshihiko KOBAYASHI  Kiyoshi OKUDA 《The Journal of reproduction and development》2014,60(1):73-77

Isolated stromal cells from the ampullary and isthmic parts of bovine oviductal tissues were cultured in monolayer and spheroid (cell aggregate) systems. Prostaglandin F2α (PGF) plays a crucial role in oviductal contraction and is produced by oviductal epithelial cells in cattle. Since stromal cells of many organs produce PGF, PGF production by bovine oviductal stromal cells was investigated. After PGF synthesis was confirmed, the utility of isolation and culture methods for oviductal stromal cells was evaluated by PGF production in the present study. The homogeneity of the cells was > 99%. PGF production of the cells was increased by tumor necrosis factor-α. The stromal cells aggregated and formed a spheroid by the treatments with several reagents. PGF production was higher in the spheroid culture than in the monolayer culture. The isolation and culture methods described here will facilitate studies of the physiological function of bovine oviductal stromal cells.  相似文献