Time-course comparison of pulmonary inflammation induced by intratracheal instillation of four different nickel oxide nanoparticles in male Fischer rats     

Toshio Kobayashi  Yutaka Oshima  Yasuhiro Tsubokura  Takako Muroi  Shozo Ajimi  Makoto Nakai  Kenji Kawaguchi  Takeshi Sasaki  Naohide Shinohara  Nobuya Imatanaka 《Journal of toxicologic pathology》2021,34(1):43

Occupational exposure to nickel oxide (NiO) is an important cause of respiratory tract cancer. Toxicity is known to be associated with the dissociated component, i.e. nickel (II) ions. To address the relationship between physicochemical properties, including solubility in artificial lysosomal fluid, of NiO and time-course changes in the pulmonary response, we conducted an intratracheal instillation study in male Fischer rats using four different well-characterized NiO products, US3352 (NiO A), NovaWireNi01 (NiO B), I small particle (NiO C), and 637130 (NiO D). The NiOs were suspended in purified water and instilled once intratracheally into male F344 rats (12 weeks old) at 0 (vehicle control), 0.67, 2, and 6 mg/kg body weight. The animals were euthanized on days 3, 28, or 91 after instillation, and blood analysis, bronchoalveolar lavage fluid (BALF) testing, and histopathological examination were performed. The most soluble product, NiO B, caused the most severe systemic toxicity, leading to a high mortality rate, but the response was transient and surviving animals recovered. The second-most-soluble material, NiO D, and the third, NiO A, caused evident pulmonary inflammation, and the responses persisted for at least 91 days with collagen proliferation. In contrast, NiO C induced barely detectable inflammation in the BALF examination, and no marked changes were noted on histopathology. These results indicate that the early phase toxic potential of NiO products, but not the persistence of pulmonary inflammation, is associated with their solubility.  相似文献   

A spontaneously occurring malignant ovarian Sertoli cell tumor in a young Sprague Dawley rat     

Yuichi Kinoshita  Katsuhiko Yoshizawa  Yuko Emoto  Michiko Yuki  Takashi Yuri  Nobuaki Shikata  Susan A. Elmore  Airo Tsubura 《Journal of toxicologic pathology》2016,29(1):53-59

Primary ovarian tumors are generally uncommon in rats used in toxicologic studies. A malignant Sertoli cell tumor was present in the ovary of a 19-week-old female Sprague Dawley rat. Macroscopically, the mass was white and firm, 10 × 13 × 17 mm in size, and located in the right ovary. Histopathologically, the mass was composed of nests of pleomorphic cells, which formed seminiferous-like tubules separated by a thin fibrovascular stroma. The tubules were lined by tumor cells, which had basally located nuclei and abundant eosinophilic and vacuolated cytoplasm. In some areas, the tumor cells were arranged in a retiform growth pattern, mimicking a rete testis/ovarii. Disseminated metastases to the surfaces of the mesentery, spleen and liver were also present. Immunohistochemically, many tumor cells were strongly positive for vimentin, estrogen receptor α and Ki 67. Some tumor cells were positive for pancytokeratin and inhibin α. These findings closely resemble those of an ovarian-derived human malignant Sertoli cell tumor. From our review of the literature, we believe this is the first report of a spontaneous malignant Sertoli cell tumor in the ovary of a young laboratory rat. This case might provide useful historical control information for rat toxicity studies.  相似文献   

Quantitative structure—activity studies of insect growth regulators. XI. Stimulation and inhibition of N-acetylglucosamine incorporation in a cultured integument system by substituted N-tert-butyl-N,N′-dibenzoylhydrazines     

Yoshiaki Nakagawa  Yoshihiro Soya  Katsumi Nakai  Nobuhiro Oikawa  Keiichiro Nishimura  Tamio Ueno  Toshio Fujita  Norio Kurihara 《Pest management science》1995,43(4):339-345

The ability to stimulate N-acetylglucosamine (GluNAc) incorporation in-vitro of a number of N-tert-butyl-N,N′-dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in-vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in-vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in-vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle.  相似文献   

Matrix-metalloproteinases-2 and -9 production in bovine endometrial cell culture   总被引：1，自引：0，他引：1  

Hashizume K  Takahashi T  Shimizu M  Todoroki J  Shimada A  Hirata M  Sato T  Ito A 《The Journal of reproduction and development》2003,49(1):45-53

In vitro cell culture is a convenient tool for studying cellular mechanisms. In the present study, production of matrix-metalloproteinases (MMPs) in bovine endometrial (containing both epithelial and stromal cells) monolayer cells was examined. Blastocysts attached to the endometrial cells in a monolayer culture were examined for their effects on MMP-2 production. Initial attachment of blastocysts to the monolayer inhibited MMP-2 production by endometrial cells. But once trophoblast cells began to migrate into the endometrial cell layer, MMP-2 production increased, and at the same time MMP-9 production also became evident in the medium. In order to understand how blastocysts affected MMP-2 production, we examined the effect of progesterone, estradiol, insulin-like growth factors (IGFs), tumor necrosis factors (TNFs), and interferon-tau (IFN-tau) supplementation. It was IFN-tau that inhibited the production of MMP-2. In addition, progesterone at a lower dose appeared to inhibit MMP-2 production. Both TNF-alpha and TNF-beta strongly stimulated the production of MMP-2 and MMP-9, whereas IGFs had no effect. Based on these findings, it appears that conceptus has the capacity to inhibit MMP activity.  相似文献   

Intracytoplasmic sperm injection in the pig: where is the problem?   总被引：1，自引：0，他引：1  

Kren R  Kikuchi K  Nakai M  Miyano T  Ogushi S  Nagai T  Suzuki S  Fulka J  Fulka J 《The Journal of reproduction and development》2003,49(4):271-273

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Appearance of race Pfs:5 of spinach downy mildew fungus, Peronospora farinosa f. sp. spinaciae, in Japan     

Mamoru Satou  Kazufumi Nishi  Masaharu Kubota  Michiko Fukami  Hideaki Tsuji  Kees van Ettekoven 《Journal of General Plant Pathology》2006,72(3):193-194

The races for the causal agent of spinach downy mildew Peronospora farinosa f. sp. spinaciae were identified by inoculation of race-differential cultivars. One isolate was identified as Pfs:5s and the others belonged to a new race. This is the first report of race Pfs:5 and another new race in Japan.  相似文献   

Preliminary experiments on mechanical stretch-induced activation of skeletal muscle satellite cells in vivo     

Tomowa SAKATA  Ryuichi TATSUMI  Michiko YAMADA  Sei-Ichi SHIRATSUCHI  Shinpei OKAMOTO  Wataru MIZUNOYA  Akihito HATTORI  Yoshihide IKEUCHI 《Animal Science Journal》2006,77(5):518-525

We have shown in vitro that mechanical stretch triggers activation of quiescent satellite cells of skeletal muscle to enter the cell cycle through an intracellular cascade of events including nitric oxide (NO) synthesis that results in the release of hepatocyte growth factor (HGF) from its extracellular association and its subsequent presentation to signaling receptors. In order to explore the activation mechanism in vivo, stretch experiments were conducted in the living animal using our suspension model developed. This system used the weight of the hind portion of rats to stretch the inside muscles of the left hind limb suspended for a period of 0.5–2.0 h. At the end of the stretch period, the rats received an intraperitoneal injection of bromodeoxyuridine followed by immunocytochemistry for its incorporation as an index of satellite cell activation in vivo. Depending on the period of stretch, bromodeoxyuridine labeling was increased significantly over the contralateral unstretched leg or control muscle from untreated rats. A stretched muscle extract prepared from the 2 h stretched tissue by incubating it in PBS, showed the active form of HGF as revealed by immunoblotting and it could stimulate the activation of unstretched satellite cells. Also, administering NO synthase inhibitor L‐NAME prior to muscle stretch abolished the stretch activation of satellite cells. Therefore, the results from these experiments demonstrate that stretching muscle triggers NO synthesis and HGF release, which could activate satellite cells in vivo.  相似文献   

Evaporation of snow intercepted by a todo-fir forest (I) water balance easurements     

Yuichiro Nakai 《Journal of Forest Research》1997,2(1):67-67

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The effect of strain, growth stage, and cultivating condition of Ganoderma lucidum on 5α-reductase inhibition     

Jie Liu  Rumi Fujita  Michiko Sato  Kuniyoshi Shimizu  Fumiko Konishi  Kiyoshi Noda  Shoichiro Kumamoto  Chie Ueda  Hisatoshi Tajiri  Shuhei Kaneko  Yoshitaro Suimi  Ryuichiro Kondo 《Journal of Wood Science》2005,51(2):189-192

The inhibitory effects of 102 methanol extracts of 40 mycelia, 9 culture fluids, and 53 fruiting bodies of 40 strains of Ganoderma lucidum on 5-reductase were investigated. The methanol extract of the fruiting body of each strain was found to show the strongest 5-reductase inhibitory activity among the extracts tested.  相似文献   

The relationship between macroscopic strain and crystal lattice strain in wood under uniaxial stress in the fiber direction     

Takahisa Nakai  Hiroyuki Yamamoto  Tetsuya Nakao 《Journal of Wood Science》2005,51(2):193-194

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