Clearance of Theileria sergenti-infected bovine red blood cells in severe combined immune deficiency mice     

Yutaka Terada  Masayoshi Tsuji  Katsuro Hagiwara  Kiyoshi Takahashi  Chiaki Ishihara 《Veterinary parasitology》1995,60(3-4):221-228

Clearance of Theileria sergenti-infected bovine red blood cells (Bo-RBCs) from the blood circulation of severe combined immune deficiency (SCID) mice was studied to help understand the mechanisms of anemia developing in cattle infected with T. sergenti. For the clearance test, Bo-RBC samples having 2%, 58%, and 76% parasitemia and, as a control, parasite-free Bo-RBCs were prepared in the Bo-RBC-SCID mouse model. The T. sergenti-infected Bo-RBCs and the uninfected control Bo-RBCs were separately labeled with two, green and red, fluorescent dyes, mixed together, and injected intravenously into SCID mice. The blood samples collected at various time points were observed under a fluorescent microscope, and the numbers of green and red fluorescing RBCs were counted differentially to determine the clearance rates of T. sergenti-infected and uninfected Bo-RBCs. This test clearly demonstrated that the Bo-RBC samples having higher parasitemias were cleared faster from the blood circulation of SCID mice. The results suggest that the intravascular clearance system in SCID mice may have a mechanism by which T. sergenti-parasitized and non-parasitized Bo-RBCs are recognized and cleared differentially.  相似文献   

Purification and characterization of an angiotensin I‐converting enzyme inhibitory peptide derived from porcine troponin C     

Kazunori KATAYAMA  Makoto TOMATSU  Hidetaka FUCHU  Masaaki SUGIYAMA  Satoshi KAWAHARA  Kiyoshi YAMAUCHI  Yukio KAWAMURA  Michio MUGURUMA 《Animal Science Journal》2003,74(1):53-58

To search for a novel angiotensin I‐converting enzyme (ACE) inhibitory peptide, porcine skeletal troponin was hydrolyzed with pepsin. This hydrolysate showed ACE inhibitory activity, and was applied to various kinds of chromatography to separate an active peptide. Analysis using a protein sequencer identified this peptide as RMLGQTPTK (9mer). This sequence was estimated to occur at the 44–52 position of troponin C, and its 50% inhibitory protein concentration (IC₅₀) was 34 µM. RMLGQTP (7mer), a partial peptide of 9mer, showed activity with an IC₅₀ of 503 µM. RP‐HPLC analysis of a reaction mixture of 9mer and ACE showed that 9mer was slowly hydrolyzed by ACE. On the other hand, 7mer was rapidly hydrolyzed by ACE. Activity of 9mer was reduced as its hydrolysis by ACE proceeded. To estimate the resistance of 9mer to digestive proteases after oral administration, it was reacted with pepsin, α‐chymotrypsin, or trypsin. In each of these reaction mixtures, a significant amount of 9mer remained as a substrate after digestion. Remaining ACE inhibitory activity was close to that of 9mer. These results suggest that 9mer might not be digested after oral administration, because of its relatively high resistance to digestive proteases. Therefore, 9mer might be expected to work well in vivo as an ACE inhibitor.  相似文献   

Bisphenol A and nonylphenol bioconcentration in spotted halibut Varaspar variegates     

Ho chul  LEE  Kiyoshi  SOYANO  Atsushi  ISHIMATSU  Masaki  NAGAE  Shinya  KOHRA  Yasuhiro  ISHIBASHI  Koji  ARIZONO  Yuji  TAKAO 《Fisheries Science》2004,70(1):192-194

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Effects of gibberellins and benzylandenine on dormancy and flowering of Lilium speciosum     

Kiyoshi Ohkawa 《Scientia Horticulturae》1979,10(3):255-260

GA_{4 + 7} (1000 mg/l), alone or in combination with BA (100 mg/l), was found to induce shoot emergence and flowering in dormant bulbs of L. speciosum, while GA₃, alone or in combination with BA, had no effect. BA had a significant influence on increasing flower numbers, particularly when combined with GA_{4 + 7}.  相似文献   

Biochemical characteristics and in-vitro drug sensitivity of Salmonella typhimurium, Copenhagen variety isolated from domestic and feral pigeons, crows, a kite, chickens and animals in Japan.     

G Sato  N Ishiguro  M Asagi  C Oka  T Kawanishi  T Inoue 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1977,39(6):609-617

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Glycidol degrades scrapie mouse prion protein     

Yamamoto M  Horiuchi M  Ishiguro N  Shinagawa M  Matsuo T  Kaneko K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(9):983-990

Agents of transmissible spongiform encephalopathy (prion) are known to be extremely resistant to physicochemical inactivation procedures such as heat, radiation, chemical disinfectants such as detergents, alcohols, glutaraldehyde, formalin, and so on. Because of its remarkable resistance, it is difficult to inactivate prion. Chemical inactivation seems to be a practical method because it is applicable to large or fixed surfaces and complicated equipment. Here, three epoxides: beta-propiolactone, propylene oxide, and glycidol (GLD) were examined of their inactivation ability against scrapie-mouse prion protein (PrP(Sc)) under various conditions of chemical concentration, incubation time, and temperature. Among these chemicals, GLD worked most effectively and degraded PrP into small fragments. As a result of the bioassay, treatment with 3% GLD for 5 hr and 5% GLD for 2, 5 hr or 12 hr at room temperature prolonged the mean incubation time by 44, 30, 110 and 73 days, respectively. From dose-incubation time standard curve, the decrease in infectivity titers were estimated as 10(3) or more. Therefore, degradation of PrP(Sc) by GLD decreased the scrapie infectivity. It is also suggested that pH and salt concentrations influence the effect of GLD. Although further study is necessary to determine the optimal condition, GLD may be a potential prion disinfectant.  相似文献   

Transcriptional regulation of dectin-2 promoter in transgenic mouse     

Bonkobara M  Yudate T  Yagihara H  Washizu T  Cruz PD  Ariizumi K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(12):1483-1489

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Progesterone stimulation by LH involves the phospholipase-C pathway in bovine luteal cells   总被引：2，自引：0，他引：2  

Nishimura R  Shibaya M  Skarzynski DJ  Okuda K 《The Journal of reproduction and development》2004,50(2):257-261

Luteinizing hormone (LH)-stimulated steroidogenesis in luteal cells is known to be mediated through the activation of cyclic AMP (cAMP)-dependent protein kinase, and to be also modulated by calcium-dependent mechanisms. In the present study, we tested the hypothesis that LH stimulates progesterone (P4) production in bovine luteal cells through activation of phospholipase (PL) C by using a cell culture system. Bovine mid-luteal cells (Days 8-12 of the estrous cycle) were cultured for 24 h and then exposed to a PLC inhibitor (U-73122; 10 microM) with or without LH (10 ng/ml) for 4 h. U-73122 blocked LH-stimulated P4 production without affecting cAMP accumulation. Moreover, exposure of luteal cells to PLC increased P4 production in a dose-dependent manner. These results support the hypothesis that the luteotropic action of LH in bovine luteal cells is mediated not only by activation of adenylate cyclase but also by activation of PLC.  相似文献   

Effects of prostaglandin F(2alpha) and nitric oxide on the secretory function of bovine luteal cells   总被引：1，自引：0，他引：1  

Korzekwa A  Jaroszewski JJ  Bogacki M  Deptula KM  Maslanka TS  Acosta TJ  Okuda K  Skarzynski DJ 《The Journal of reproduction and development》2004,50(4):411-417

The objective of the present study was to investigate the influence of prostaglandin F(2alpha) (PGF (2alpha)) and nitric oxide (NO) on production of steroids and PGs by culturing bovine luteal cells obtained from ovaries on days 8-12 of the estrous cycle with a nitric oxide (NO) donor (Spermine NONOate), and a NO synthase inhibitor (N(G)-nitro-L-arginine methyl ester dihydrochloride: L-NAME). When the cells were exposed for 24 h to PGF(2alpha) (10(-7)-10(-5) M), production of progesterone (P(4)) increased significantly at all doses used (P<0.05). Moreover, PGF(2alpha) stimulated PGF(2alpha) production (P<0.01), depressed testosterone (T) production (P<0.05), but did not affect synthesis of prostaglandin E(2) (PGE(2)). Spermine NONOate decreased P(4) production to 66%, 47% and 34% of the control concentration after treatment with 10(-5) M, 10(-4) M and 10(-3) M, respectively, but did not affect T production, and increased PGF(2alpha) synthesis (P<0.05) and PGE(2) (P<0.01) at all doses used. L-NAME increased production of P(4) (P<0.01) but did not affect (P>0.05) secretion of T, PGF(2alpha) and PGE(2). Estradiol-17beta (E(2)) was detectable on the level of sensitivity of assay and was not significantly altered by any treatments. The overall results suggest that PGF(2alpha) and NO produced locally in bovine CL play roles in the regulation of the secretory function of the bovine CL as auto/paracrine factors.  相似文献   

Expression of Prnp mRNA (prion protein gene) in mouse spermatogenic cells     

Fujisawa M  Kanai Y  Nam SY  Maeda S  Nakamuta N  Kano K  Kurohmaru M  Hayashi Y 《The Journal of reproduction and development》2004,50(5):565-570

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