Fish Pathology
Online ISSN : 1881-7335
Print ISSN : 0388-788X
ISSN-L : 0388-788X
Volume 31 , Issue 4
Showing 1-15 articles out of 15 articles from the selected issue
  • C. S. Wang, K. F. J. Tang, G. H. Kou, S. N. Chen
    1996 Volume 31 Issue 4 Pages 177-182
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The present study demonstrates the first discovery of a yellow head disease-like virus (YHDLV) in Penaeus japonicus that were diagnosed as white spot disease and describes the histological changes and the characters of the virus under electron microscopical observation. In histological studies, cells with the basophilic inclusion bodies and hypertrophied nuclei were found in various tissues, including the lymphoid organ, interstitial hepatopancreatic tissue, cardiac tissue, gill tissue, connective tissue, cuticular epidermis and hematopoietic tissue. Transmission electron micrographs revealed the presence of rod-shaped, enveloped virions in the cytoplasm of the necrotic cells. The virus was 150-200 nm in length and 40-50 nm in width, but extraordinarily long viruses were also detected in the cells. The features of the YHDLV were very similar to yellow head disease virus of Penaeus monodon in Thailand.
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  • Tatsuya Kobayashi, Teruo Miyazaki
    1996 Volume 31 Issue 4 Pages 183-190
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    In December 1992, a disease characterized by cutaneous erosion and ulceration occurred in Japanese eels, Anguilla japonica, during the post-harvest stocking in cages showered with well water (15deg;C). Since then, this disease sometimes occurs and causes mass mortalities during the stocking before shipping.This study evaluated histological changes, virological characteristics and pathogenicity of an isolated virus from ulcerative lesions.Inocula prepared from the skin lesions, kidney and spleen of naturally diseased eels produced cytopathic effects in EK-1 and EPC cells at 15deg;C. Electron micrographs of infected EPC cells revealed virus virions with the average size of 188×70 nm. Replication of the virus was not inhibited by IUdR, but it was sensitive to ether. Serological tests showed a similarity of this isolate to two eel rhabdoviruses, EVA and EVEX. The isolated rhabdovirus had pathogenicity to eels by an intracutaneous injection at a viral level of 107 TCID50. Moribund fish of experimental infection displayed cutaneous lesions accompanied with necrosis of the dermal fibrocytes, hemorrhage and inflammatory cellular infiltration.These symptoms were similar to those of the natural cases. Moreover, moribund fish showed diffuse necrosis of the hematopoietic tissue, renal tubules, splenic pulps and hepatic parenchyma.The presence of virions in the above necrotic lesions was clearly observed by electron microscopy. We propose to designate this disease as rhabdoviral dermatitis in Japanese eel.
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  • Kazuaki Uno, Takahiko Aoki, Ryuji Ueno, Iwao Maeda
    1996 Volume 31 Issue 4 Pages 191-196
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The present study examined the pharmacokinetics of nalidixic acid (NA) in rainbow trout (Oncorhynchus mykiss) and sodium nifurstyrenate (NFS) in yellowtail (Seriola quinqueradiata) after a bolus intravascular administration. The doses of NA and NFS were 20 mg/kg and 10 mg/kg body weight, respectively. Rainbow trout were kept in tanks with running fresh water at 15.0 ±0.3deg;C. Yellowtail were kept in tanks with running sea water at 21.3±0.2deg;C. Serum concentrations of NA and NFS were determined using high performance liquid chromatography. Serum concentrations of NA in rainbow trout and NFS in yellowtail were best described by a two-compartment open model. The half-lives for the distribution phase (T1/2α) and elimination phase (T1/2β) were 1.4 h and 13 h for NA in rainbow trout and 0.6 h and 7.7 h for NFS in yellowtail, respectively. The apparent volume of distribution (Vd) and total body clearance (ClB) were estimated to be 1.01 l/kg and 54.7 ml/kg/h for NA in rainbow trout and 2.99l/kg and 271 ml/kg/h for NFS in yellowtail, respectively. The serum protein bindings in vivo were determined to be 10.9 ± 4.0% for NA in rainbow trout and 69.4± 7.5% for NFS in yellowtail, respectively. As an application of this pharmacokinetic study, the oral bioavailability and the dosage regimens of NA in rainbow trout and NFS in yellowtail were briefly evaluated.
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  • Jose Roberto Kfoury, Nobuaki Okamoto, Makoto Tanaka, Mamoru Yoshimizu, ...
    1996 Volume 31 Issue 4 Pages 197-201
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    “Rash”, a subchronic, debilitating and non-fatal inflammatory skin disease has been found in cultured rainbow trout (Oncorhynchus mykiss) in several areas of Japan over the past five years. This condition was observed from small fish (11cm in body length) to mature-size animals, however, most of the affected fish were market size (in Japan, 20cm/120g). Morbidity sometimes reaches as high as 48% and causes a significant economic impact, since those fish loose commercial value. A self-limited clinical course and healing of the lesion could be observed after 6 to 8 weeks. “Rash” signs included the presence of bright red, non-raised, ulcerated or not, defined to petechial scattered lesions on the ventral and/or lateral surfaces of the fish. Histopathological features included a subchronic focal to non-focal, non-suppurative dermatitis with various degrees of ulceration and an extensive mononuclear inflammatory infiltration. “Rash” etiology still remains unknown.
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  • Hari Suprapto, Takaaki Hara, Toshihiro Nakai, Kiyokuni Muroga
    1996 Volume 31 Issue 4 Pages 203-207
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A toxin lethal to fish was purified from extracellular products (ECP) of Edwardsiella tarda by ion exchange chromatography and gel filtration. The purified toxin is a protein having proteolytic activities and lethal toxicity to Japanese eel Anguilla japonica with the LD50 of 1.6μg per g of fish body weight. Molecular weight of the protein was estimated to be 37 kDa by SDS-PAGE. SDS-PAGE, Western blot and immunodiffusion analyses revealed that the 37 kDa protein was present in the ECP and ICC (intracellular components) of virulent strains of E. tarda but not in those of avirulent strains, indicating that this toxin plays an important role in the pathogenicity of E. tarda.
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  • Sataporn Direkbusarakom, Angkana Herunsalee, Mamoru Yoshimizu, Yoshio ...
    1996 Volume 31 Issue 4 Pages 209-213
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Extracts from 18 Thai traditional herbs were prepared by boiling with ethanol under a soxhlet apparatus and virucidal activity against fish pathogenic viruses (IHNV, OMV and IPNV) was tested by plaque reduction method using CHSE-214 cells.
    When the viruses were exposed to herb extract at 500μg/ml before inoculation to CHSE-214 cells, all herbs showed antiviral activity against IHNV and OMV, reducing plaques by 65-100% and 20-100%, respectively. However, in the case of IPNV, no plaque reduction was observed by any herbs tested.
    Some kinds of the herb extracts prevented viral infection, when CHSE-214 cells were treated with 100μg/ml of herbs for 3 h before viral infection. The percent of plaque reduction above 50% was observed in 6, 8 and 6 kinds of herb extracts for IHNV, OMV and IPNV, respectively. These extracts may inhibit the viral adsorption to the cells.
    When 100μg/ml of the herb extracts was applied for infected cells, the percent of plaque reduction above 50% was observed in 0, 8 and 5 kinds of herb extracts for IHNV, OMV and IPNV, respectively. This means that some of the herb extracts may inhibit the replication of OMV and IPNV in CHSE-214, but no herb has any effect for IHNV infection.
    Moreover, all of the tested herb extracts showed low toxicity to CHSE-214 cell line, the cytotoxic 50% value being 1, 200-41, 500μg/ml.
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  • Jeong-Ho Kim, Hiroshi Yokoyama, Kazuo Ogawa, Sei Takahashi, Hisatsugu ...
    1996 Volume 31 Issue 4 Pages 215-220
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The humoral immune response of ayu (Plecoglossus altivelis) to the microsporidian parasite Glugea plecoglossi was investigated. The antibody levels of sera from ayu, to which G. plecoglossi spores were administered orally, were measured by indirct ELISA. While the cysts appeared from 27 D.P.I. (days post-infection), the antibodies against the intact spores were first detected at 10 D.P.I. and no more significant increases in the antibody levels were observed. The uptake of spores through the gut epithelium was histologically observed. Additionally, sera from ayu in a cultured stock which showed 50% prevalence of infection were obtained and the antibody levels were measured by the ELISA. The antibody level was variable but no important difference was observed between fish with or without cysts. The intensity of infection (number of cysts) was not related to the antibody level both in the artificially and naturally-infected fish. These results suggest that the antibody production against the intact spores of G. plecoglossi plays no protective role against G. plecoglossi infection.
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  • Toshio Nakatsugawa, Yoshisuke Iida
    1996 Volume 31 Issue 4 Pages 221-227
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A chronic disease occurred in cultured ayu, Plecoglossus altivelis, from May to July in 1995 in Kyoto and Hiroshima Prefectures. Cumulative mortalities reached 16-30% during that period. One type of bacterium was isolated from the kidney of diseased ayu which characteristically showed pale gills, pale viscera, and swallen spleen and kidney. The isolates of the bacterium were confirmed to be pathogenic to ayu, Japanese flounder, Paralichthys olivaceus, and red sea bream, Pagrus major, by intramuscular injection. The organism was identified as a Pseudomonas species based on the biochemical properties.
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  • Sylvia Rodriguez, Ma Pilar Vilas, Ma Carmen Gutierrez, Sara I. Perez
    1996 Volume 31 Issue 4 Pages 229-230
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
  • J. Larenas, C. Astorga, J. Contreras, H. Garcés, J. Fryer, P. S ...
    1996 Volume 31 Issue 4 Pages 231-232
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
  • Satoru Matsuoka, Kiyoshi Inouye, Kazuhiro Nakajima
    1996 Volume 31 Issue 4 Pages 233-234
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Occurrences of red seabream iridoviral disease (RSIVD) in cultured marine fishes were investigated. The infection was identified by using Giemsa staining method and/or indirect immunofluorescence test with a monoclonal antibody against red seabream iridovirus (RSIV). In total RSIVD was found in 20 cultured marine fish species in 17 prefectures locating south-western part of Japan from 1991 to 1995. Infected fishes include 18 Perciformes, 1 Pleuronectiformes and 1 Tetraodontiformes.
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  • Susumu Yasumoto, Kazuya Nagasawa
    1996 Volume 31 Issue 4 Pages 235-236
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
  • Masashi Maita, Hideki Ushio, Nobuaki Okamoto
    1996 Volume 31 Issue 4 Pages 237-238
    Published: December 15, 1996
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Coho salmon were bled at a rate of 2% of the body weight and physiological parameters were examined after 14 days.
    Hematocrit values in anemic and control fish were 12.8±3.2, 31.0±0.7%, respectively. In anemic fish, plasma phospholipid, total cholesterol, free cholesterol, and alkaline phosphatase activity were significantly lower (p<0.01)than those of controls. The concentration of ATP was reduced by approximately 46% in the gill, and by 37% in the kidney of anemic fish, compared to control values. The amount of ATP-related compounds were also significantly lower in both the gill (p<0.01) and kidney (p<0.05) in anemic fish. No significant difference was observed in Na+-K+ATPase activities in both tissues.
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  • Hisatsugu Wakabayashi, Kenzo Sawada, Kouji Ninomiya, Eita Nishimori
    1996 Volume 31 Issue 4 Pages 239-240
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A new bacterial disease, causing mass mortalities among pond-cultured ayu (Plecoglossus altivelis) in Shiga and Tokushima prefectures, was studied. Bloody ascites appeared to be the most characteristic sign of the disease. The causative organism was similar to Pseudomonas putida, but it did not produce fluorescent pigment and reduced nitrate to nitrite. Most of the isolates showed the API 20NE profile number of 1-140-457. An antiserum against the causative organism did not react with Ps. putida ATCC12633T.
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  • 1996 Volume 31 Issue 4 Pages 241-246
    Published: December 15, 1996
    Released: October 26, 2009
    JOURNALS FREE ACCESS
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