Equine coronavirus induces apoptosis in cultured cells     

Suzuki K  Matsui Y  Miura Y  Sentsui H 《Veterinary microbiology》2008,129(3-4):390-395

Equine coronavirus (ECoV) was first isolated from a diarrheic foal and was found genetically similar to group II coronaviruses. However, its pathological characteristics were not adequately investigated. In our preliminary in vitro investigation, ECoV-induced cell death was observed in bovine kidney-derived MDBK cells. Based on this finding, we investigated whether the ECoV-induced CPE was apoptosis. Following ECoV infection, MDBK cells showed morphological changes such as cell rounding and detachment from the culture surface. Moreover, syncytium formation was observed as the other type of cytopathic effect in ECoV infection. Morphologic and biochemical features of apoptosis, such as nuclear fragmentation and DNA ladder formation, were also detected in ECoV-infected cells. Moreover, as is commonly observed in coronavirus infection in other animals, the activities of effecter caspases – caspase-3/7 – and initiator caspases – caspase-8 and caspase-9 – that are representative factors in the death receptor-mediated apoptotic pathway and mitochondrial apoptotic pathway, respectively, were increased in ECoV-infected MDBK cells. Therefore, it was suggested that ECoV can induce apoptosis in MDBK cells via a caspase-dependent pathway. Apoptotic death of infected cells is detrimental because it causes cell and tissue destruction and inflammatory responses. Although the pathological characteristics of ECoV are largely unknown, apoptosis may be the pathological basis of lesions of the digestive system in ECoV infection.  相似文献   

Combination treatment of kenaf bast fiber for high viscosity pulp     

Bibhuti B. Mazumder  Yoshito Ohtani  Zhou Cheng  Kazuhiko Sameshima 《Journal of Wood Science》2000,46(5):364-370

The viscosity of kenaf bast fiber has been found to be highly sensitive and variable with different pulping methods; therefore, it is important to choose proper chemicals and conditions for pulping and bleaching of kenaf bast fiber. From several pulping experiments, a nonconventional pulping method with a combination of ammonium oxalate pretreatment followed by soda pulping at normal pressure and then acidic chlorite delignification was developed to obtain high-viscosity pulp (162 centipoise). The optimum level of alkali dosage of soda pulping for high-viscosity pulp was found to be 15% (on pulp as NaOH). Pulps showed linear relations between viscosity and xylose or glucose contents, but the combination pulping method gave extremely high pulp viscosity, beyond the relations. The highest viscosity pulp from kenaf bast fiber demonstrated a tear index about twofold and a folding endurance 6.2-fold higher than those of Manila hemp pulp with comparable tensile and burst indexes. The high-viscosity pulp could be used in the production of high-quality currency paper or longevity paper for special uses.Part of this paper was presented at the 43rd Lignin Symposium, Fuchu, Tokyo, October 26–27, 1998  相似文献   

Characterization of St-Valerien-Like Virus Genome Detected in Japan     

Go SATO  Hisayuki IDO  Masahiro KIUCHI  Michiyo KATAOKA  Kazuhiko KATAYAMA  Yukinobu TOHYA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(7):1045-1050

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Establishment and characterization of immortalized bovine endometrial epithelial cells     

Hanako Bai  Toshihiro Sakurai  Rulan Bai  Sachiko Yamakoshi  Etsunari Aoki  Mariko Kuse  Kiyoshi Okuda  Kazuhiko Imakawa 《Animal Science Journal》2014,85(8):799-804

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Maintenance of mouse trophoblast stem cells in KSR-based medium allows conventional 3D culture     

Shuai SUN  Shota YANO  Momo O NAKANISHI  Michiko HIROSE  Kazuhiko NAKABAYASHI  Kenichiro HATA  Atsuo OGURA  Satoshi TANAKA 《The Journal of reproduction and development》2021,67(3):197

Mouse trophoblast stem cells (TSCs) can differentiate into trophoblast cells, which constitute the placenta. Under conventional culture conditions, in a medium supplemented with 20% fetal bovine serum (FBS), fibroblast growth factor 4 (FGF4), and heparin and in the presence of mouse embryonic fibroblast cells (MEFs) as feeder cells, TSCs maintain their undifferentiated, proliferative status. MEFs can be replaced by a 70% MEF-conditioned medium (MEF-CM) or by TGF-ß/activin A. To find out if KnockOut^TM Serum Replacement (KSR) can replace FBS for TSC maintenance, we cultured mouse TSCs in KSR-based, FBS-free medium and investigated their proliferation capacity, stemness, and differentiation potential. The results indicated that fibronectin, vitronectin, or laminin coating was necessary for adhesion of TSCs under KSR-based conditions but not for their survival or proliferation. While the presence of FGF4, heparin, and activin A was not sufficient to support the proliferation of TSCs, the addition of a pan-retinoic acid receptor inverse agonist and a ROCK-inhibitor yielded a proliferation rate comparable to that obtained under the conventional FBS-based conditions. TSCs cultured under the KSR-based conditions had a gene expression and DNA methylation profile characteristic of TSCs and exhibited a differentiation potential. Moreover, under KSR-based conditions, we could obtain a suspension culture of TSCs using extracellular matrix (ECM) coating-free dishes. Thus, we have established here, KSR-based culture conditions for the maintenance of TSCs, which should be useful for future studies.  相似文献   

Histopathological changes in the pancreas due to decreased pancreatic blood flow in a canine tachycardia-induced cardiomyopathy model     

Aritada YOSHIMURA  Takahiro OHMORI  Kokoro ITOU  Ryo ISHI  Yuri MATSUMURA  Yuhei WADA  Miori KISHIMOTO  Tomoko IWANAGA  Naoki MIURA  Kazuhiko SUZUKI  Ryuji FUKUSHIMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(5):780

In dogs, pancreatic acinar cell injury is thought to be caused by decreased pancreatic blood flow due to heart failure. In previous our report, it demonstrated that decreased heart function causes a significant decrease in pancreatic blood flow in heart failure dog model caused by rapid ventricular pacing (RVP). However, the types of histopathological changes remain unclear. We aimed to verify the types of histopathological changes occurring in the pancreatic tissue due to decreased heart function. After RVP for 4 weeks, atrophy of pancreatic acinar cells, characterized by a decrease in zymogen granules, was observed in all areas of the pancreas. In conclusion, the result of this study suggests that attention should be paid to ischemia/hypoperfusion injury in the pancreas.  相似文献   

Effect of Free-Air CO₂ Enrichment (FACE) on the Community Structure of Aquatic Organisms in Floodwater of a Japanese Paddy Field during the Flooding Period of Rice Cultivation     

Masatsugu Yamazaki  Masumi Okada  Kazuhiko Kobayashi  Makoto Kimura 《Soil Science and Plant Nutrition》2005,51(2):271-279

In the present study, the effect of free-air CO₂ enrichment (FACE) on the diversity and the community structure of aquatic organisms in the floodwater of a paddy field in northern Japan was evaluated. The varieties and the number of aquatic organisms ranging from 30 μm to 2 cm were compared four times at intervals of 20 d between the FACE (599 ppm CO₂) and ambient air (384 ppm CO₂) plots during the flooding period of rice cultivation. Aquatic organisms were classified mainly at the order level. Twenty-eight taxonomical groups were detected, and the number of groups in the FACE plots was significantly lower than that in the ambient plots. Zygnematales and Chaetonotida were less frequently detected in the FACE plots. The population densities of Zygnematales, and Chaetonotida also tended to be lower in the FACE plots than in the ambient plots in the late flooding period (after 50 d of flooding). No groups showed a significantly higher population density and frequency of presence in the FACE plots than in the ambient plots. The seasonal variations in the number of taxonomical groups and the community structure of aquatic organisms were less conspicuous in the FACE plots than in the ambient plots. We concluded that the FACE conditions adversely affected the communities of aquatic organisms in paddy fields.  相似文献   

Methane uptake and nitrous oxide emission in Japanese forest soils and their relationship to soil and vegetation types   总被引：1，自引：1，他引：1  

Tomoaki MORISHITA  Tadashi SAKATA  Masamichi TAKAHASHI  Shigehiro ISHIZUKA  Takeo MIZOGUCHI  Yoshiyuki INAGAKI  Kazuhiko TERAZAWA  Satoshi SAWATA  Masanori IGARASHI  Hiroshi YASUDA  Yasuhiro KOYAMA  Yoshihito SUZUKI  Nobuyuki TOYOTA  Masamichi MURO  Masaru KINJO  Hirokazu YAMAMOTO  Daitaro ASHIYA  Yoichi KANAZAWA  Tetsu HASHIMOTO  Hidetaka UMATA 《Soil Science and Plant Nutrition》2007,53(5):678-691

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Effects of elevated carbon dioxide concentration on biological nitrogen fixation, nitrogen mineralization and carbon decomposition in submerged rice soil     

Weiguo Cheng  Kazuyuki Inubushi  Kazuyuki Yagi  Hidemitsu Sakai  Kazuhiko Kobayashi 《Biology and Fertility of Soils》2001,34(1):7-13

Controlled-environment chambers were used to study the effects of elevated CO₂ concentrations on biological N fixation, N mineralization and C decomposition in rice soil. In three chambers, CO₂ concentration was maintained at 353ᆣ/396ᆫ µmol mol^-1 (day/night; ambient CO₂), while in another three, CO₂ was maintained at 667ᆸ/700ᆽ µmol mol^-1 (day/night; elevated CO₂) throughout the growing season. Rice (var. Nipponbare) seedlings were grown under either ambient or elevated CO₂ concentrations, and then transplanted into the soils in the corresponding chambers. At different growth stages, soil samples were taken from surface (0-1cm) and sub-surface (1-10cm) layers at the centre of four hills, then sieved (<1 mm) to remove root residues. Fresh soil was used to measure N fixation activity (using the acetylene reduction assay), NH₄⁺ content and organic C. Separate sets of soil samples were transferred to serum bottles and anaerobically incubated at 30°C for 30 days to measure potential rates of N mineralization and C decomposition. Under an elevated atmospheric CO₂ concentration, acetylene reduction activity significantly increased in the surface soil layer during the early cultivation stages and in the sub-surface soil layer during the latter part of cultivation. There was no difference in the amount of NH₄⁺ in fresh soils between elevated and ambient CO₂ chambers, while the rate of N mineralization was increased by elevated CO₂ during the latter part of cultivation. Soils from the elevated CO₂ chambers had obviously higher rate of C decomposition than that from the ambient CO₂ chambers. CH₄ production gradually increased with the growth of rice plants. These results suggest that elevated CO₂ affected biological N fixation, N mineralization and C decomposition in submerged rice soil during the different growth stages of rice.  相似文献   

Receptor assay-guided isolation of anti-GABAergic insecticidal alkaloids from a fungal culture   总被引：2，自引：0，他引：2  

Kuriyama T  Kakemoto E  Takahashi N  Imamura K  Oyama K  Suzuki E  Harimaya K  Yaguchi T  Ozoe Y 《Journal of agricultural and food chemistry》2004,52(12):3884-3887

The gamma-aminobutyric acid (GABA) receptor bears sites of action for insecticides. To discover GABA receptor-directed insecticides in natural products, fungal culture extracts were screened for their ability to inhibit specific binding of the radiolabeled noncompetitive antagonist [3H]1-(4-ethynylphenyl)-4-n-propyl-2,6,7-trioxabicyclo[2.2.2]octane to housefly head membranes. The screening efforts led to the isolation of two alkaloids from Aspergillus terreus: PF1198A (alantrypinone) and PF1198B (serantrypinone), which had IC50 values of 0.34 and 2.1 microM, respectively, in this assay. These compounds were ca. 47-61-fold selective for housefly vs rat GABA receptors. Both compounds showed insecticidal activity against Myzus persicae in the range of 100-500 ppm. Binding assay-guided screening should provide significant opportunities for the identification of novel and selective insecticides.  相似文献