Distinguishable staining with neutral red for GFP-marked and GFP-nonmarked <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> strains simultaneously colonizing root surfaces     

Teruo Nonomura  Hiromi Tajima  Yuko Kitagawa  Naoko Sekiya  Kayoko Shitomi  Mami Tanaka  Kazuhiko Maeda  Yoshinori Matsuda  Hideyoshi Toyoda 《Journal of General Plant Pathology》2003,69(1):45-48

 Green fluorescent protein (GFP)-marked Fusarium oxysporum f. sp. melonis and nonmarked F. oxysporum f. sp. fragariae were stained with neutral red. The neutral red stained vacuoles of the fungi without disturbing GFP fluorescence in the cytoplasm. GFP-marked fungi showed fluorescent hyphae with dark-stained vacuoles, whereas nonmarked fungi were detected as nonfluorescent hyphae with dark-dotted vacuoles. Root colonization by these two fungi was monitored using this method. Microconidia attached similarly to the root surface and elongated vegetative hyphae. Only the pathogenic fungi invaded, causing necrosis at the inoculation site. Thus, the present method enabled us to track simultaneously the various formae speciales of F. oxysporum colonizing the root surface. Received: March 25, 2002 / Accepted: September 27, 2002  相似文献   

Ultrastructural study on the epithelial responses against attachment of indigenous bacteria to epithelial membranes in peyer's patches of rat small intestine     

Inamoto T  Kawata Y  Qi WM  Yamamoto K  Warita K  Kawano J  Yokoyama T  Hoshi N  Kitagawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(3):235-241

The ultrastructure of epithelial responses against the membrane adhesion of indigenous bacteria was investigated in the follicle-associated epithelium (FAE) of rat small intestine. The most frequent adherence of the various morphological types of bacteria to the epithelial membranes was found at the apex of the FAE. The attachment sites were deeply invaginated, and their bottoms were deformed into a sharp cone shape. Four layers with different electron densities were formed just beneath the apical membranes by microfilaments which surrounded the invaginations. The electron density of each layer was gradually decreased as being apart from the invaginations. The extremities of some bacteria in the invaginations were deformed into sharpened shapes. The cell walls of the extremities of the bacteria were occasionally dissolved in the invaginations, and their cytoplasms were slightly swollen with low electron densities. In some invaginations, the attached bacteria were eliminated to leave their fragments such as filamentous debris and a part of cell walls. Finally these remnants disappeared completely. When the bacterial colonies existed in the middle region of the FAE, the attachment of bacteria resulted in the engulfment of bacteria by M cells. The degenerated bacteria whose cytoplasmic matrices were separated into high electron dense materials and cleared materials were occasionally engulfed by ordinary microvillous columnar epithelial cells or goblet cells throughout the FAE. These findings suggest that the epithelial cells reject the attachment of live indigenous bacteria and that the M cells absorb indigenous bacteria in rat Peyer's patches.  相似文献   

Surveillance of avian influenza viruses in Northern pintails (Anas acuta) in Tohoku District, Japan     

Jahangir A  Watanabe Y  Chinen O  Yamazaki S  Sakai K  Okamura M  Nakamura M  Takehara K 《Avian diseases》2008,52(1):49-53

Among winter migratory waterfowl, Northern pintails (Anas acuta), in one of the largest flocks in Tohoku district, northeast Japan, were surveyed for influenza A viruses at five wintering sites in three prefectures, viz., Aomori, Akita, and Miyagi. A total of 38 influenza A viruses were isolated from 2066 fecal samples collected during November 2006 through March 2007. The overall isolation rate was 1.84%. Eleven different subtypes were isolated, including nine H5N2, seven H6N8, seven H10N1, four H4N6, three H6N1, three H11N9, and one each of H1N1, H6N2, H6N5, H10N9, H11N1. Only the H4N6 subtype was detected during two successive months, November and December, from Lake Ogawara of Aomori prefecture. One wintering site, Lake Izunuma of Miyagi prefecture, was negative for virus isolation throughout the study period. During the sampling period, the highest virus isolation rate was in December (4.90%) followed by November (2.18%), January (0.91%), and February (0.30%). Virus isolation was negative for samples collected in March 2007. These results suggest that influenza viruses are introduced by Northern pintail when they migrate into Japan, but the viruses are not maintained in the flocks, most likely because the birds are not breeding during the winter. We believe that this relatively large data set creates a strong foundation for future studies of avian influenza virus (AIV) prevalence, evolution, and ecology in wintering sites, along with the role of Northern pintails in the spread of AIV during their migration from northern Russia and Asia to Japan.  相似文献   

Histopathological classification of systemic Mycobacterium avium complex infections in slaughtered domestic pigs     

Hibiya K  Kasumi Y  Sugawara I  Fujita J 《Comparative immunology, microbiology and infectious diseases》2008,31(4):347-366

The aim of this study was to classify the histopathological features of pigs infected with Mycobacterium avium complex (MAC). We used slaughtered pig organs systemically infected with MAC. The results showed granulomatous lesions which were observed predominantly in the digestive organs and regional lymph nodes rather than respiratory organs. The histological picture showed a wide range of granulomatous stages from exudative to fibrotic reactions to the MAC infection. Eosinophils and giant cells were characteristically observed in the exudative reactions. The histopathological type in primary focus tended to be maintained in the respective organs. Most strains with the same genotype showed pathogenicity for guinea pigs irrespective of the type of granuloma. Although these findings suggest that different stages of a granulomatous lesion originating from the same causative agent might influence histological patterns, other possibilities such as the hereditary background of the host, or the effects of viral infections should be considered.  相似文献   

Association between intestinal lymphangiectasia and expression of inducible nitric oxide synthase in dogs with lymphoplasmacytic enteritis     

Takuro NAGAHARA  Koichi OHNO  Itsuma NAGAO  Taisuke NAKAGAWA  Yuko GOTO-KOSHINO  Masaya TSUBOI  James K. CHAMBERS  Kazuyuki UCHIDA  Hirotaka TOMIYASU  Hajime TSUJIMOTO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(1):20

Intestinal lymphangiectasia (IL) is a common complication in dogs. Since nitric oxide (NO) is known to relax the lymphatic vessel, we evaluated inducible NO synthase (iNOS) expression using immunohistochemistry in 13 dogs with lymphoplasmacytic enteritis (LPE) with or without IL. The duodenal iNOS expressing cells were significantly increased in dogs with IL-negative or IL-positive LPE dogs (P=0.025, P=0.007) compared with control dogs. However, there was no significant difference in iNOS expression between IL-positive and IL-negative tissues. Based on these results, there is no clear evidence for the NO overproduction in the pathogenesis of IL in dogs with LPE. Factors other than NO could, thus, contribute to IL in dogs with LPE.  相似文献   

Compositions of extractive components in the testes and ovaries of various sea urchins: comparisons among species,sexes, and maturational status     

Murata  Yuko  Yoshimura  Hirokazu  Unuma  Tatsuya 《Fisheries Science》2020,86(1):203-213

Fisheries Science - We investigated the compositions of free amino acids (FAAs), organic acids (OAs), and nucleotides and their related compounds (NAs) in the gonads of edible sea urchins in Japan....  相似文献   

Interannual variation of the diet shifts and their effects on the fatness and growth of age‐0 Pacific bluefin tuna (Thunnus orientalis) off the southwestern Pacific coast of Japan     

Yuko Hiraoka  Ko Fujioka  Hiromu Fukuda  Mikio Watai  Seiji Ohshimo 《Fisheries Oceanography》2019,28(4):419-433

We investigated the effect of feeding habits on the fatness (length–weight relationship (LW)) and otolith growth of age‐0 Pacific bluefin tuna (PBF) (fork length (FL) of 15.0–29.9 cm) collected off the southwestern Pacific coast of Japan from July to August during 2010–2015. The feeding rate on Clupeiformes (FRc) was substantially influenced by the path of the Kuroshio Current during early summer. We suggest that the following patterns occurred in the feeding habits of PBF. In 2012 and 2014, the short distance from the coast to the Kuroshio provided high overlap between PBF and Clupeiformes and increased the opportunity for feeding, and this pattern likely caused the observed diet shift from Crustacea to Clupeiformes by smaller PBF in the studied years than those in other years. In 2011 and 2015, the encounter probability for Clupeiformes might have been low due to the long distance to the Kuroshio Current, which led PBF to actively consume non‐Clupeiformes Teleostei. In contrast, in August 2010 and 2015, PBF did not encounter Clupeiformes or other Teleostei and may have been forced to feed on a large number of Crustacea; this effect was likely due to high water temperatures. Despite the interannual fluctuation in the timing of the diet shift and the feeding intensity (FI), these factors did not contribute to growth in length; rather, they contributed to fatness. Considering size‐dependent mortality in the larval stage, these results suggest that only fast‐growing individuals survive, even if the feeding conditions drastically change.  相似文献   

Antiradical function of sulfhydryl residues and oxidative stress markers in dairy cattle plasma     

Masahito TANAKA  Yuko KAMIYA  Mitsuru KAMIYA  Shigeru SHIOYA  Yutaka NAKAI 《Animal Science Journal》2007,78(1):61-65

The antiradical function of sulfhydryl (SH) residue in dairy cattle plasma and the relationship of SH residue concentrations to other oxidative stress markers, ascorbic acid and thiobarbituric acid reactive substance (TBARS) in plasma were investigated. The concentration of reduced glutathione (GSH) in phosphate buffer solution (pH 7.6) and SH residues in dairy cattle plasma decreased significantly (P < 0.05) in vitro by the addition of peroxyradicals at 38°C, depending on incubation periods. The decrease of GSH concentration with the peroxyradical solution was partially protected by the addition of sodium ascorbate solution. A positive and significant correlation with SH residues and albumin concentration in the fresh plasma obtained from 15 dairy cattle was observed (P < 0.05). The SH residue concentration was not correlated with the TBARS concentration in plasma. The total ascorbic acid and SH residues concentration in the plasma correlated positively but not significantly (P < 0.10). These results suggested that SH residues in dairy cattle plasma play important part in the antiradical function.  相似文献   

Isolation and characterization of tyrosinase inhibitor-producing microorganisms from marine environment     

Chiaki Imada  Yuko Sugimoto  Tomoko Makimura  Takeshi Kobayashi  Naoko Hamada  Etsuo Watanabe 《Fisheries Science》2001,67(6):1151-1156

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Comparison of microfilaria concentration method for Setaria digitata infection in cattle and for Dirofilaria immitis infection in dogs     

Watanabe Y  Yang CH  Tung KC  Ooi HK 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(5):543-545

Several peripheral blood microfilaria concentration methods that use Acetone (Acetone test), 2% formalin (modified Knott method), 5% Tween 20 solution, distilled water, 1% or 0.1% SDS were compared for their efficacy in detecting Setaria digitata microfilaria in cattle. The Acetone test was found to be more efficacious than the modified Knott method or the 5% Tween 20 solution test for detecting the S. digitata microfilaria in bovine blood. However, besides the Acetone test, the modified Knott method was also found to be suitable for Dirofilaria immitis microfilaria detection in dogs. SDS and distilled water were found not to be effective as hemolytic agent for the disruption of the red blood cell of both the cattle and dogs. Thus, the Acetone test is recommended for the primary screening of microfilaremia of S. digitata in cattle.  相似文献