Estimating the spawning season of black sea bream Acanthopagrus schlegelii in Hiroshima Bay,Japan, from temporal variation in egg density

Fisheries Science - We aimed to determine the spawning period of black sea bream Acanthopagrus schlegelii in Hiroshima Bay, Japan, based on the distribution of its eggs, to assist in the resource...     

Susceptibilities against bovine lactoferrin with microorganisms isolated from mastitic milk

Antibacterial effects of bovine lactoferrin were studied in vitro against microorganisms isolated from mastitic milk in Tokachi area, Hokkaido, Japan. Microorganisms isolated were Escherichia coli (11 isolates), Klebsiella pneumoniae (5 isolates), enterococci (8 isolates), Staphylococcus aureus (10 isolates), coagulase negative staphylococci (CNS, 13 isolates), streptococci (11 isolates), Prototheca zopfii (7 isolates) and yeast-like fungi (9 isolates). Lactoferrin has been known as a multifunctional protein and its antimicrobial effect is one of the most essential function of it. In order to compare their susceptibilities against lactoferrin, the minimal inhibitory concentration values were estimated by a microplate assay method using 96-well microplate, which involved measuring the optical density of the cultures. Prototheca zopfii was highly sensitive to bovine lactoferrin and complete inhibition of this microorganism was observed even at the low concentration of 7 mug/ml. On the other hand, E. coli and enterococci showed resistance against lactoferrin action and staphylococci showed strain-dependent resistance.     

Anisotropic thermal properties of molded carbon phenolic spheres

Anisotropic thermal properties of molded carbon phenolic spheres (CPS), a mixture of sugi wood charcoal powders and phenol formaldehyde resin molded with a hot press, were investigated. The effects of the carbonizing temperature, particle size of chars, and density of the CPS on thermal properties were discussed. The molded CPS specimens were measured for their thermal properties using the laser flash method in both horizontal and vertical directions. The configuration of the CPS was observed by scanning electron microscopy. Anisotropy of the thermal properties (thermal diffusivity and thermal conductivity) between horizontal and vertical directions of the molded CPS was much higher than that of the uncarbonized molded phenolic spheres. Therefore, converting wood into molded CPS is an effective way to enhance the thermal-anisotropy properties. More marked effects of the carbonizing temperature, particle size, and density were observed in the horizontal direction than in the vertical direction. Anisotropy in thermal properties of the molded CPS may be considered an advantage for developing a new fire-retardant material for wood composites.An outline of this study was presented at the 47^th and 48^th annual meetings of the Japan Wood Research Society, Kochi and Shizuoka, 1997 and 1998.     

Antimicrobial susceptibilities of Mycoplasma isolated from bovine mastitis in Japan

Mycoplasma spp. are highly contagious pathogens and intramammary Mycoplasma infection is a serious issue for the dairy industry. As there is no effective vaccine for Mycoplasma infection, control depends on good husbandry and chemo‐antibiotic therapy. In this study, antimicrobial susceptibility of Mycoplasma strains recently isolated from cases of bovine mastitis in Japan was evaluated by minimum inhibitory concentration (MIC). All Mycoplasma bovis strains were sensitive to pirlimycin, danofloxacin and enrofloxacin, but not kanamycin, oxytetracycline, tilmicosin or tylosin. M. californicum and M. bovigenitalium strains were sensitive to pirlimycin, danofloxacin, enrofloxacin, oxytetracycline, tilmicosin and tylosin, but not to kanamycin. This is the first report to describe the MIC of major antimicrobial agents for Mycoplasma species isolated from bovine mastitis in Japan.     

Atomic-Scale Images of the Growth Surface of Ca1-xSrxCuO2 Thin Films

The surface microstructure of c-axis (Ca,Sr)CuO(2) thin films, grown by laser molecular beam epitaxy on SrTiO(3)(001) substrates, was studied by ultrahigh-vacuum scanning tunneling microscopy (STM). Images were obtained for codeposited Ca1-xSrxCuO(2) thin films, which show a layered-type growth mode. The surfaces consist of atomically flat terraces separated by steps that are one unit cell high. A pronounced dependence of the growth mechanism on the Sr/Ca ratio of the films was observed. Atomic resolution STM images of the CuO(2) sheets in the ab plane show a square lattice with an in-plane spacing of 4 angstroms; the lattice contains different concentrations of point defects, depending on the polarity of the sample-tip bias.     

Myoglobin subfractions: abnormality in duchenne type of progressive muscular dystrophy

Human metmyoglobin was separated electrophoretically into four subfractions: Mb(1), Mb(2), Mb(3), and Mb(4), which divide into at least two biochemically independent groups: Mb(1) and Mb(2), and Mb(3), and Mb(4). In normal subjects, Mb(1) constituted the predominant component; Mb(2), Mb(3), and Mb(4) were the minor components in this descending order. In the Duchenne type of progressive muscular dystrophy, on the contrary, a remarkable decrease in Mb(1) and a concomitant increase in Mb(3) were observed. This unique abnormality in the relative distribution of myoglobin subfractions was recognized only in the Duchenne type and not in other types of progressive muscular dystrophy or in other myopathies.     

Mitogenesis in response to PDGF and bombesin abolished by microinjection of antibody to PIP2

The turnover of phosphatidylinositol 4,5-bisphosphate (PIP2) is believed to constitute a crucial step in the signaling pathways for stimulation of cells by a variety of bioactive substances, including mitogens, but decisive evidence for the idea has not been obtained. In the present study, a monoclonal antibody to PIP2 was microinjected into the cytoplasm of NIH 3T3 cells before or after exposure to mitogens. The antibody completely abolished nuclear labeling with [3H]thymidine induced by platelet-derived growth factor and bombesin, but not by fibroblast growth factor, epidermal growth factor, insulin, or serum. The findings strongly suggest that PIP2 breakdown is crucial in the elicitation and sustaining of cell proliferation induced by some types of mitogens such as platelet-derived growth factor and bombesin.     

Propolypeptide of von Willebrand factor circulates in blood and is identical to von Willebrand antigen II

The generally mild bleeding disorder of von Willebrand disease is associated with abnormalities of two distinct plasma proteins, the large multimeric von Willebrand factor (vWF), which mediates platelet adhesion, and von Willebrand antigen II (vW AgII), which is of unknown function. The two proteins were found to have a common biosynthetic origin in endothelial cells and megakaryocytes, which explains their simultaneous absence in the severe form of this hereditary disease. Shared amino acid sequences from a 100-kilodalton plasma glycoprotein and from vW AgII are identical to amino acid sequences predicted from a complementary DNA clone encoding the 5' end of vWF. In addition, these proteins have identical molecular weights and immunologic cross reactivities. Monoclonal antibodies prepared against both proteins recognize epitopes on the pro-vWF subunit and on a 100-kilodalton protein that are not present on the mature vWF subunit in endothelial cell lysates. In contrast, polyclonal antibodies against vWF recognize both pro-vWF and vWF subunits. Thus, the 100-kilodalton plasma glycoprotein and vW AgII are identical proteins and represent an extremely large propolypeptide that is first cleaved from pro-vWF during intracellular processing and then released into plasma.     

Immune response during the onset of coliform mastitis in dairy cows vaccinated with STARTVAC®

The immune response during the onset of coliform mastitis in vaccinated cows was investigated by measuring lactoferrin (LF), interleukin-8 ( IL-8), and interleukin-1β (IL-1β) concentrations and somatic cell counts in 28 milk samples at the onset of acute coliform mastitis (ACM) and 73 milk samples at the onset of peracute coliform mastitis (PCM). Vaccinated ACM, unvaccinated ACM, and vaccinated PCM showed significantly higher values for LF and IL-1β levels than unvaccinated PCM (p < .01). The IL-8 concentration was lower in vaccinated PCM than in unvaccinated PCM (p < .05). There was no significant difference in somatic cell counts for each parameter. There were no significant differences in the parameters between vaccinated and unvaccinated ACM cows, or vaccinated ACM and PCM cows. From the above results, it is suggested that mastitis vaccination improved the early immune response, particularly at the onset of PCM, and played a large role in host defense against the initial infection.     

Comparative pathogenicity study on antigenically variant strains of Enterococcus seriolicida

Enterococcus seriolicida strains were divided into two groups, agglutinating and nonagglutinating, by a slide agglutination test using antiserum against the YT-3 strain. Intraperitoneal injection of agglutinating and nonagglutinating strains into yellowtail, Seriola quinqueradiata Temminck & Schlegel, revealed that nonagglutinating strains were more virulent than agglutinating strains. Two nonagglutinating and highly pathogenic strains SS91–014 and SS91–092 were subcultured 30 times in brain heart infusion broth, and the agglutination titres of 50 colonies from subcultures 1, 2, 3, 4, 5, 6, 11, 16, 21, 26 and 30 against anti-YT-3 serum were determined. Transformation from a nonagglutinating (1:<4) to an agglutinating (1: ≥4) pattern was first observed at the sixteenth subculture, and the ratio of agglutinating to nonagglutinating substrains rose until the thirtieth subculture. At this time, 70% of the SS91–014 population and 52% of the SS91–092 population were transformed to an agglutinating pattern. When the pathogenicity of four transformed substrains with different agglutination titres was tested in yellowtail, the nonagglutinating substrain showed higher pathogenicity than the agglutinating substrains, but no relationship between LD₅₀ values and the agglutination titres of transformed substrains was observed. The pathogenicity of E. seriolicida appears to be related to the agglutination pattern, although it was not demonstrated that this property is solely responsible for pathogenicity.