Virological and serological studies of porcine respiratory coronavirus infection on a Japanese farm   总被引：1，自引：0，他引：1  

Usami Y  Fukai K  Ichikawa Y  Okuda Y  Shibata I  Motoyama C  Imai K  Kirisawa R 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(9):929-936

We detected transmissible gastroenteritis virus (TGEV) antibodies in pig farms in Tochigi prefecture, although the farms had no past record of TGEV vaccination or TGE. Among the farms, Farm A showed a high antibody incidence. We could not confirm if either TGEV or porcine respiratory coronavirus (PRCV) induced the antibodies, since conventional tests failed to discriminate PRCV from TGEV. Therefore, we conducted virological and serological examinations of this farm for 4 years to establish the etiology - TGEV or PRCV. Although no TGEV was detected, PRCVs were isolated from the nasal samples of pigs. Using a commercial ELISA kit, it was found that the antibodies detected in pigs of all the raising stages and sows were raised against PRCV but not TGEV. The phylogenetic analysis of the nucleotide sequences of the isolates showed that they were closely related to each other, and formed a separate cluster apart from the U.S.A. and European strains. In Cesarean-derived, colostrums-deprived piglets inoculated with a PRCV isolate, no clinical signs were seen, and the viruses were mainly isolated from the nasal samples. Moreover, viral genes were detected from the nasal sample of the contact pig. The result suggested that PRCV infection was located in the nasal cavity of pigs, and horizontal transmission easily occurs. From these results, PRCVs with different origins from the exotic PRCVs might be prevalent in pig farms in Japan.  相似文献   

Effect of bovine lactoferrin on functions of activated feline peripheral blood mononuclear cells during chronic feline immunodeficiency virus infection   总被引：1，自引：0，他引：1  

Kobayashi S  Sato R  Aoki T  Omoe K  Inanami O  Hankanga C  Yamada Y  Tomizawa N  Yasuda J  Sasaki J 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(5):429-435

Feline immunodeficiency virus (FIV) infection is characterized by chronic overactivation of immune and inflammatory system, resulting in anergic state and dysfunction of immune cells. Lactoferrin (LF), a glycoprotein present in exocrine secretions and neutrophils, plays an important role in host defense system. Our previous study showed that oral administration of bovine LF (bLF) suppressed oral inflammation, improved the clinical symptoms and decreased serum gamma-globulin as a marker of inflammation in FIV-infected cats with intractable stomatitis. The anti-inflammatory effect was partly involved in regulation of neutrophil function by bLF. In this study, to clarify the relationship between anti-inflammatory effects of bLF and peripheral blood mononuclear cells (PBMC), we examined the effect of bLF on proliferation, cell cycle progression and cytokine expression in mitogen-activated PBMC. MTT [3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl tetrazolium bromide] assay showed that bLF inhibited the concanavalin A (ConA)-induced cell proliferation in FIV-infected cats with the asymptomatic carrier and AIDS-related complex (ARC) phase. Bovine LF restored ConA-induced cell cycle progression and resulted in suppression of the induced apoptosis in feline PBMC. Real-time RT-PCR showed that bLF suppressed ConA-induced expression of interferon-gamma and interleukin-2 in cells of the ARC group regardless of the time of its addition to the medium. These results suggest the hypothesis that therapy with bLF may have the potential to improve and protect functions of overactivated lymphocytes by modulating the cell proliferation, cell cycle and cytokines expression in cats in terminal stage of FIV infection.  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   

Immunohistochemical distribution of inwardly rectifying K+ channels in the medulla oblongata of the rat     

Yamamoto Y  Ishikawa R  Omoe K  Yoshikawa N  Yamaguchi-Yamada M  Taniguchi K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(3):265-271

The inwardly rectifying K+ channels, Kir1.1, Kir2.3 and Kir4.1-Kir5.1, are the candidate chemosensory molecules for CO2/H+. We determined the mRNA expression and immunohistochemical localization of these channels in the medulla oblongata of the rat. RT-PCR analysis revealed mRNAs of Kir1.1, Kir2.3, Kir4.1 and Kir5.1 were detected in the medulla. The immunoreactivities for Kir1.1, Kir2.3, Kir4.1, and Kir5.1 were observed in the medulla, and immunolabeling pattern was varied by the subunit. Immunoreactivities for Kir1.1 and Kir2.3 were observed in the nerve cell bodies and glial cells both in the chemosensory areas [nucleus tractus solitarius (NTS), nucleus raphe obscurus (RO), pre-B?tzinger complex (PreB?tC)] and non-chemosensory area [hypoglossal nucleus (XII), inferior olive nucleus (IO)]. Kir4.1 immunoreactivity was observed in the glial cells and neuropil, especially in XII and IO. Kir5.1 immunoreactivity was observed in the nerve cell bodies in the XII, RO, and PreB?tC, but not in the NTS or IO. In the NTS, a dense network of varicose nerve fibers showed immunoreactivity for Kir5.1. Our findings suggest that Kir channels may not act specific to the central chemoreception, but regulate the ionic properties of cellular membranes in various neurons and glial cells.  相似文献   

Estrogen modulates the skeletal muscle regeneration process and myotube morphogenesis: morphological analysis in mice with a low estrogen status     

Rattanatrai CHAIYASING  Akihiro SUGIURA  Takuro ISHIKAWA  Koichi OJIMA  Katsuhiko WARITA  Yoshinao Z. HOSAKA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(12):1812

The purpose of this study was to elucidate the functions of estrogen and two estrogen receptors (ERs; ERα and ERβ) in the myoregeneration process and morphogenesis. Cardiotoxin (CTX) was injected into the tibialis anterior (TA) muscles of ovariectomized (OVX) mice to induce muscle injury, and subsequent myoregeneration was morphologically assessed. The diameter of regenerated myotubes in OVX mice was significantly smaller than that in intact mice at all time points of measurement. OVX mice also showed lower muscle recovery rates and slower speeds than did intact mice. ER protein levels showed a predominance of ERβ over ERα in both intact and OVX states. The ERβ level was increased significantly at 7 days after CTX injection in OVX mice and remained at a high level until 14 days. In addition, continuous administration of E2 to OVX mice in which muscle injury was induced resulted in a significantly larger diameter of regenerated myotubes than that in mice that did not receive estrogen. The results indicate that estrogen is an essential factor in the myoregeneration process since estrogen depletion delayed myoregeneration in injured muscles and administration of estrogen under the condition of a low estrogen status rescued delayed myoregeneration. The results strongly suggested that ERβ may be a factor that promotes myoregeneration more than does ERα.  相似文献   

Plasma concentrations of inhibin A in cattle with follicular cysts: relationships with turnover of follicular waves and plasma levels of gonadotropins and steroid hormones     

Todoroki J  Noguchi J  Kikuchi K  Ohnuma K  Ozawa M  Kaneko H 《Domestic animal endocrinology》2004,27(4):333-344

We investigated the profiles of circulating levels of inhibin A and total inhibin in beef cows with follicular cysts in relation to the patterns of follicular development and circulating gonadotropins and steroid hormones. Turnover of follicular waves was monitored in five cows every 2 days for 70 days from 10 days after detection of estrus without ovulation. The mean interwave intervals were 19.6 ± 1.0 days (n = 18 waves with cysts from the five cows). Circulating levels of inhibin A were approximately 170 pg/ml before emergence of follicular waves with cysts and increased (P < 0.05) concomitantly with follicle emergence. High concentrations of inhibin A (greater than 300 pg/ml) were noted for 7 days during the growth phase of cystic follicles, but inhibin A levels decreased gradually when development of the cysts reached a plateau. This profile of inhibin A was similar to those of total inhibin and estradiol, but was inversely related to the changes in plasma FSH concentrations. LH pulse frequency and mean concentrations of LH in cows with cysts were higher than those observed in the luteal phase of normal cyclic cows. These results indicate that the capacity to secrete inhibin, as well as estradiol, is maintained in cystic follicles, the growth of which is extended by LH secretion at levels greater than those seen in the normal luteal phase. Inhibin A plays an important role in the extension of interwave intervals by suppressing recruitment of a new cohort of follicles.  相似文献   

Genetic and serological characterization of novel serotype G8 bovine group A rotavirus strains isolated in Japan     

Fukai K  Onoda H  Itou T  Sato M  Miura Y  Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1413-1416

G8 bovine group A rotaviruses isolated in Japan were genetically and serologically characterized. The VP7 gene nucleotide and amino acid sequences revealed high identity with each other. All Japanese G8 strains were classified into the same lineage in the phylogenetic analysis based on VP7 gene sequences. Antisera to four Japanese G8 strains neutralized other G8 strains, but their neutralizing titers were between 8-fold lower and 2-fold higher than homologous strains. These results suggest that the VP7s of Japanese G8 strains have similar genetic and serologic characteristics. Observed differences in the neutralizing abilities of antisera for each strain appear to depend on differences in the P serotypes/genotypes.  相似文献   

Susceptibility to N-methyl-N-nitrosourea-induced retinal degeneration in different rat strains     

Yuko Emoto  Katsuhiko Yoshizawa  Yuichi Kinoshita  Michiko Yuki  Takashi Yuri  Airo Tsubura 《Journal of toxicologic pathology》2016,29(1):67-71

To evaluate the potential role of genetic background in the susceptibility to retinal degeneration induced by N-methyl-N-nitrosourea (MNU), female rats of the Sprague-Dawley (SD), Long-Evans (LE) and Copenhagen (CH) strains were administered 50 mg/kg MNU or saline at 7 weeks of age. Retina morphology and morphometric analysis of all rats was performed 7 days after MNU administration. Atrophy of both the peripheral and central outer retina occurred in all rat strains exposed to MNU. Decreased photoreceptor cell ratio and increased retinal damage ratio were observed. The severities of the retinal atrophy were similar among all three rat strains. In conclusion, MNU-induced photoreceptor degeneration developed consistently in all three strains regardless of the absence (SD rats) or presence (LE and CH rats) of melanin in the retina, suggesting that genetic and melanin factors did not affect photoreceptor cell death after MNU.  相似文献   

Hormone level analysis on adventitious root formation in Eucalyptus globulus     

Naoki Negishi  Katsuhiko Nakahama  Nobuaki Urata  Mikiko Kojima  Hitoshi Sakakibara  Akiyoshi Kawaoka 《New Forests》2014,45(4):577-587

Eucalyptus globulus is the one of the most economically important trees for pulp and paper industries due to its fast growth and short harvesting cycle. However, E. globulus is well known as a woody plant that is hard to propagate vegetatively. In this study, we found wide distribution of rooting ability among seven independent genotypes we tested. Analysis of the mechanism of adventitious rooting by using the auxin transport inhibitor, N-naphthylphthalamic acid, revealed that polar auxin transport is crucial in root formation. The gravitropism of the stem was highly correlated to the percentage of adventitious root formation. Hormonal analysis showed that the levels of indole-3-acetic acid (IAA) were the same between difficult-to-root and easy-to-root genotypes, whereas levels of IAAsp (indole-3-acetyl aspartic acid) were higher in the difficult-to-root genotype, indicating that IAA metabolism might play an important role in adventitious root formation in this species. Levels of several cytokinins exhibited differences between genotypes that varied in their cutting performance and rooting ability. Furthermore, higher level of cytokinin in elongating shoots were correlated with rooting percentage. Taken together, our results indicate that both auxins and cytokinins play a role in adventitious root formation in E. globulus, and that a complex interplay between the levels of auxins and cytokinins and their metabolism might result in root formation in this commercially important plant.  相似文献   

Genetic selection for resistance to mycoplasmal pneumonia of swine (MPS) in the Landrace line influences the expression of soluble factors in blood after MPS vaccine sensitization     

Tomoyuki Shimazu  Liushiqi Borjigin  Yuki Katayama  Meihua Li  Takumi Satoh  Kouichi Watanabe  Haruki Kitazawa  Sang‐gun Roh  Hisashi Aso  Katoh Kazuo  Yoshihito Suda  Akiko Sakuma  Mituru Nakajo  Keiichi Suzuki 《Animal Science Journal》2014,85(4):365-373

We recently developed a Landrace line that is resistant to mycoplasmal pneumonia of swine (MPS) infection by genetic selection for five generations, and we reported that the immunophenotype of this line is different from that of the non‐selected line in terms of changes in peripheral blood leukocyte population after MPS vaccination. This study followed up previous findings demonstrating changes in soluble factors in blood, namely, hormones, Mycoplasma hyopneumoniae‐specific immunoglobulin G (IgG), and cytokines. These two lines were injected with MPS vaccine on days ?7 and 0 after blood sampling on those days, and blood samples were collected on days ?14, ?7, 0, 2, 7 and 14. We found changes in the levels of many hormones and cytokines in both lines. However, we found that only growth hormone (GH) and interferon (IFN)‐γ levels were statistically different between these two lines. GH concentration was reduced (day 0) and IFN‐γ concentration was increased (day 14) in the MPS‐selected line compared with the non‐selected line, despite unchanged IFN‐γ messenger RNA expression in blood cells. Although detailed mechanisms underlying these phenotypes remain unsolved, these traits would be useful to improve MPS resistance in pig production and provide an insight into MPS infection.  相似文献