A novel HPLC method for glutathione-insulin transhydrogenase assay using fluorescence labeled insulin     

N Saito  H Yamanaka  S Nagasawa 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(1):1-4

The activity of rat liver glutathione-insulin transhydrogenase (GIT) was measured by HPLC. The degradation of fluorescein isothiocyanate-I (FITC-I)-labeled insulin is separated into several peaks, which are bound different amount of FITC-I. We selected mono-fluorescein-thiocarbamylated insulin to estimate the decrease of insulin content and it became possible to assay GIT activity. This novel method was time-saving and simple, and this system could utilize instead of previous method.  相似文献   

Purification and characterization of feline ghrelin and its possible role     

Ida T  Miyazato M  Naganobu K  Nakahara K  Sato M  Lin XZ  Kaiya H  Doi K  Noda S  Kubo A  Murakami N  Kangawa K 《Domestic animal endocrinology》2007,32(2):93-105

Ghrelin, a novel 28-amino acid peptide with an n-octanoyl modification at Ser3, has been isolated from rat and human stomach as an endogenous ligand for the growth hormone secretagogue receptor. Here, we purified feline ghrelin and examined its possible physiological role in cats. The major active form of feline ghrelin is a 28-amino acid peptide octanoylated (C8:0) at Ser3; except for one amino acid residue replacement, this structure is identical to those of rat and human ghrelins. However, much structural divergence in peptide length and fatty acid modification was observed in feline ghrelin: peptides consisting of 27 or 26 amino acids lacking Gln14 and/or Arg28 were found, and the third serine residue was modified by octanoic acid (C8:0), decanoic acid (10:0), or unsaturated fatty acids (C8:1, C10:1 and C10:2). In agreement with the structural divergence, two kinds of cDNA with different lengths were isolated. Administration of synthetic rat ghrelin increased plasma growth hormone levels in cats, with a potency similar to that in rat or human. Plasma levels of ghrelin in cats increased approximately 2.5-fold after fasting. The present study indicates the existence of structural divergence in feline ghrelin and suggests that, as in other animals, ghrelin may play important roles in GH release and feeding in cats.  相似文献   

Phenotype and function of murine discrete Peyer's patch macrophage derived - dendritic cells     

Makala LH  Reyes JC  Nishikawa Y  Tsushima Y  Xuan X  Huang X  Battsetseg B  Matsuo T  Nagasawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(4):491-499

The phenotype and function of peritoneal cavity macrophage-derived dendritic cells (PEC-DC) was previously reported. In this study we have gone further in using our established culture system to generated discrete Peyer's patch dendritic cells (DPP-DC) from murine discrete Peyer's patch macrophages (DPP-M?), following stimulation with granulocyte macrophage colony stimulating factor (GM-CSF) plus interleukin 4 (IL-4) for 7 days. DPP-M? from murine small intestines were obtained by mechanical disruption of discrete Peyer's patches (DPP), followed by metrizamide density gradient centrifugation to remove Peyer's patch resident DC and debri, after which an overnight adherent step in tissue culture medium was carried out for macrophage enrichment. Characterization of the generated DPP-DC was carried out using well-established criteria of morphology, expression of membrane antigens and capacity for antigen presentation. Dendritic cells expressed DEC-205, F4/80 and CD34 at high levels, but exhibited very low CD11c levels. They were shown to present soluble protein antigen to CD3(+) spleen T cells. A comparison of the surface antigen expression in the progenitor DPP-M? population and the generated DPP-DC showed a significant decrease in MHC class II levels and a marked down regulation of the co-stimulatory molecule CD86 (B7-2). High expression of the haemopoietic progenitor marker CD34 indicates that the generated DC, possess a haemopoietic rather than myeloid origin. Taken together, these results may provide a better understanding of the complex network regulating mucosal immune responses.  相似文献   

A role for balance of interferon-gamma and interleukin-4 production in protective immunity against Neospora caninum infection   总被引：3，自引：0，他引：3  

Nishikawa Y  Inoue N  Makala L  Nagasawa H 《Veterinary parasitology》2003,116(3):175-184

A suitable balance in the production of Th1/Th2-type cytokines has a crucial role in the control of microbial infections. We investigated cytokine production patterns and effects during Neospora caninum infection, based on two mouse models and an in vitro system. In the acute infection of N. caninum, BALB/c-background IFN-gamma-deficient mice that were sensitive to the N. caninum infection showed high levels of IL-10 production, whereas significant levels of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) production were observed in resistant wild type mice. BALB/c mice vaccinated with recombinant vaccinia virus expressing N. caninum surface protein NcSRS2 resisted parasite spread throughout the body, low levels of IFN-gamma production and high levels of IL-4 production were observed compared to unvaccinated animals. The treatment of N. caninum-infected cells with IFN-gamma or IL-10 decreased the host-cell viability in an in vitro system using mouse macrophage J774A.1 cells. On the other hand, IL-4, but not IL-10 administration, increased the viability of N. caninum-infected and IFN-gamma-treated cells. In the light of the balance of Th1/Th2-type cytokine production, an IFN-gamma/IL-4 balance may have a crucial role for the control of cellular responses against the parasite invasion.  相似文献   

Comparison of macrophage scavenger receptor-A knockout mice with wild type ones in the immune response against repeated infestation with Haemaphysalis longicornis     

Kabamoto S  Bhagat NA  Suzuki H  You M  Kamio T  Tsuji N  Claveria FG  Nagasawa H  Igarashi I  Toyoda Y  Fujisaki K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):355-359

Using macrophage scavenger receptor-A knockout (SRKO) mice, we examined the role of macrophage class A scavenger receptors (MRS-A) on the immune response and acquisition of host resistance against repeated infestation with Haemaphysalis longicornis. Except for one batch of nymphs that infested one of the SRKO (SR-/-) mice and showed no appreciable reduction in body weight, all the other groups of nymphs manifested significant decrease in body weight. Both SR-/- and wild type (SR+/+) mice showed a sustained increase in anti-tick antibody titers, but SR+/+ mice showed significantly higher titers. The IFN-gamma assayed in SR-/- mouse immune sera was substantially less compared with that in SR+/+ mice. Immune sera from SR-/- and SR+/+ mice recognized the 51 and 44 kDa, and 44 kDa proteins, respectively, of the salivary gland antigen. The difference in the level of anti-tick resistance manifested by both groups of mice may be influenced by less efficient trapping and processing of tick antigens by macrophages in mice lacking for the macrophage scavenger receptors, and consequently affected the cascade of Th1 and Th2 responses. We have thus obtained valuable data that strongly infer the role of MSR-A in enhancing host defense against repeated infestation with H. longicornis.  相似文献   

The role of CD4(+) or CD8(+) T cells in the protective immune response of BALB/c mice to Neospora caninum infection     

Tanaka T  Hamada T  Inoue N  Nagasawa H  Fujisaki K  Suzuki N  Mikami T 《Veterinary parasitology》2000,90(3):183-191

The role of CD4(+) or CD8(+) T cells in the immune response of BALB/c mice against Neospora caninum infection was examined by using anti-CD4 and/or anti-CD8 monoclonal antibodies (mAbs). Mice were intraperitoneally inoculated with anti-CD4 and/or anti-CD8 mAbs before and after infection with N. caninum and observed for 30 days after infection. Most of the anti-CD4 mAb-treated mice and all of the anti-CD4 and anti-CD8 mAbs-treated mice died within 30 days post-infection (p.i.). In contrast, 100% of PBS-treated mice and 70% of anti-CD8 mAb-treated mice survived more than 30 days. When compared with phosphate-buffered saline (PBS)-treated mice, the weight of mice treated with mAbs tended to decrease. From these results CD4(+) T cells, but not CD8(+) T cells, have an important role for protection of mice against N. caninum infection. Serum antibody levels to N. caninum in infected-mice treated with anti-CD4 mAb or a mixture of anti-CD4 and anti-CD8 mAbs were lower than those in the infected mice treated with anti-CD8 mAb or PBS. The mice treated with anti-interferon-gamma (IFN-gamma) mAb produced high antibody levels to N. caninum, but all mice died within 18 days p.i. These results indicated that IFN-gamma is an important cytokine for protection against N. caninum infection at the early stage of infection. However, since CD4(+) T cells against N. caninum were essential to the production of specific antibody, these antibodies might have important roles in host protection at the later stage of infection.  相似文献   

Novel species specific antigens of trypanosoma congolense and their different localization among life-cycle stages     

Inoue N  Lluz AT  Mori T  Nagasawa H  Fujisak K  Mikami T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(10):1041-1045

Seven monoclonal antibodies (mAbs) were raised against Trypanosoma congolense procyclic form (PCF). Localization of the antigens recognized by the mAbs was determined in bloodstream form (BSF), PCF, epimastigote form (EMF) and metacyclic form (MCF) by confocal laser scanning microscopy (CLSM). Two mAbs (10F9 and 20H12) showed different fluorescent patterns among different life-cycle stages of the parasite. The 10F9 recognized a 76 kDa antigen of all life-cycle stages of the parasite and the antigen localization corresponded with that of a mitochondrion. While the 20H12 recognized 119 and 122 kDa antigens of all the life-cycle stages and the antigen localization corresponded with a flagellum in BSF and MCF, tip of a flagellum in PCF, and part of cytoplasm in EMF. Moreover, the 20H12 did not react to T. brucei gambiense, T. b. rhodesiense and T. evansi antigens in both CLSM and immunoblotting. Therefore, the antigens recognized by the 20H12 seem to be T. congolense specific. Although, further studies will be required for a full characterization of the T. congolense specific 119 and 122 kDa antigens, the mAb 20H12 and the specific antigens may be useful in not only establishment of T. congolense specific diagnosis methods but also studies on molecular mechanisms regulating differentiation of the parasite during life-cycle.  相似文献   

Fundamental studies on wood/cellulose-plastic composites: effects of composition and cellulose dimension on the properties of cellulose/PP composite   总被引：2，自引：0，他引：2  

Rashmi Kumari  Hirokazu Ito  Masahiro Takatani  Miho Uchiyama  Tadashi Okamoto 《Journal of Wood Science》2007,53(6):470-480

Although wood/cellulose-plastic composites (WPC) of low wood/cellulose content have been more accepted worldwide and are promoted as low-maintenance, high-durability building products, composites containing high wood/cellulose content are not yet developed on an industrial scale. In this study, flow properties, mechanical properties, and water absorption properties of the compounds of cellulose microfiber/polypropylene (PP) and maleic anhydride-grafted polypropylene (MAPP) were investigated to understand effects of the high cellulose content and the dimensions of the cellulose microfiber. The molding processes studied included compression, injection, and extrusion. It was found that fluidity is not only dependent on resin content but also on the dimension of the filler; fluidity of the compound declined with increased fiber length with the same resin content. Dispersion of the composite was monitored by charge-coupled device (CCD) microscope. Increasing the plastic content in the cellulose-plastic formulation improved the strength of mold in addition to the bond development between resin and filler, and the tangle of fibers. The processing mode affected the physicomechanical properties of the cellulosic plastic. Compression-molded samples exhibited the lowest modulus of rupture (MOR) and modulus of elasticity (MOE) and the highest water absorption, while samples that were injection-molded exhibited the highest MOR (70 MPa) and MOE (7 GPa) and low water absorption (2%).  相似文献   

Identification of an allele attributable to formation of cucumber-like flavor in wild tomato species (Solanum pennellii) that was inactivated during domestication     

Matsui K  Ishii M  Sasaki M  Rabinowitch HD  Ben-Oliel G 《Journal of agricultural and food chemistry》2007,55(10):4080-4086

Carbon 6 (C6)-aldehydes formed by fatty acid 13-hydroperoxide lyase (13HPL) specific to fatty acid 13-hydroperoxides (13-HPO) are important flavor constituents in fresh tomato fruits. C9-aldehydes are usually formed by 9/13HPL showing dual specificity to 9- and 13-HPOs and are scarcely found in tomato fruits. Mature red fruits of one of the introgression lines, IL1-4, generated by hybridization of a cultivated tomato (Solanum lycopersicon) to its wild relative Solanum pennellii, form high amounts of C9-aldehydes upon homogenization. The IL1-4 fruits showed high 9/13HPL activity. One of the genes isolated from IL1-4 showed a high similarity to plant 9/13HPLs. Recombinant proteins expressed in Escherichia coli showed 9/13HPL activity. Cleaved amplified polymorphic sequence analyses indicated that the gene was specific to IL1-4 and S. pennellii. S. lycopersicon had a gene having high similarity to the S. pennellii gene. It was absent in IL1-4. Among the differences of amino acid residues found between the two genes, a Cys to Ser exchange may be responsible for the inactivation of resultant protein product of S. lycopersicon gene because the Cys is an essential amino acid residue for HPL activity. From these observations, it could be assumed that a tomato gene corresponding to S. pennellii 9/13HPL gene had been inactivated through domestication of tomatoes.  相似文献   

Viability of maternally heat-stressed mouse zygotes in vivo and in vitro   总被引：3，自引：0，他引：3  

Manabu OZAWA  Yukiko YAMASAKI  Miho HIRABAYASHI  Yukio KANAI 《Animal Science Journal》2003,74(3):181-185

Mammalian preimplantation embryos are susceptible to heat stress. This present study examined how maternal heat stress affects the development of mouse zygotes in vivo and in vitro. In Experiment 1, zygotes collected from female mice that were heat‐stressed for 12 h on day 1 of pregnancy were cultured in vitro. Maternally heat‐stressed zygotes developed normally to the two‐cell stage, but the majority of embryos failed to develop into morulae or blastocysts. In Experiment 2, pregnant mice were heat‐stressed on day 1 or from day 1 to day 3 of pregnancy. The number of living fetuses on day 14 of pregnancy was lower in heat‐stressed mice than in non‐stressed mice, but the difference was significant only in successively heat‐stressed mice. These results demonstrate that maternally heat‐stressed zygotes have reduced in vitro viability, but this phenomenon does not necessarily lead to embryo loss in the maternal environment.  相似文献