Cutaneous plasmacytoma in three golden hamsters (Mesocrietus auratus)

Spontaneously occurring cutaneous tumours in three golden hamsters were characterized using histological, immunohistochemical and ultrastructural methods. Histologically, the tumours were composed of sheets of round to oval plasmacytoid cells with eccentrically placed nuclei. Tissue sections were weakly positive for anti-B lymphocyte antigen (BLA) staining. Ultrastructurally, large amounts of rough endoplasmic reticulum in the cytoplasm were observed. BLA positivity and characteristics of ultrastructure showed the plasma cell origin.     

Molecular detection of human periodontal pathogens in oral swab specimens from dogs in Japan

Periodontal diseases are known to be major diseases in humans, and are also common in dogs. The purpose of the present study was to analyze the distribution of periodontitis-related bacterial species using oral swab specimens collected from 26 pet dogs. The distribution of an animal gingival organism Porphyromonas gulae, in addition to 10 human periodontitis-related bacterial species, including Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Capnocytophaga ochracea, Capnocytophaga sputigena, Prevotella intermedia, Prevotella nigrescens, Aggregatibacter actinomycetemcomitans, Campylobacter rectus, and Eikenella corrodens, were evaluated by polymerase chain reaction with species-specific sets of primers. Porphyromonas gulae, Tannerella forsythia and Campylobacter rectus were detected in almost all dogs analyzed, all of which should be regarded as common members of oral flora in dogs. Then, isolation and identification of the Porphyromonas species in swab specimens were performed. There were 35 strains isolated from 22 dogs, and broad-range polymerase chain reaction and sequencing methods revealed that approximately 70% of them were Porphyromonas gulae. In contrast, the frequency of Porphyromonas gingivalis was extremely low. These findings indicate the presence of specific periodontitis-related pathogens in pet dogs, especially Porphyromonas gulae.     

Mycobacteriosis in two captive Florida manatees (Trichechus manatus latirostris).

Two male Florida manatees (Trichechus manatus latirostris) died at the marine aquarium in Inagi City, Tokyo, Japan. Acid-fast bacteria were demonstrated in tuberculoid nodules in the lungs from both manatees. Mycobacterium marinum and M. fortuitum were isolated from one manatee; M. marinum and M. kansasii were cultured from the second animal. This report confirms the pathogenicity and potentially fatal outcome of mycobacterial infection in manatees. In addition, the pathologic response to infection with these mycobacteria in manatees is similar to that associated with Mycobacterium spp. in other animals.     

Evaluation from otolith Sr stable isotope ratios of possible juvenile growth areas of Japanese eels collected from the West Mariana Ridge spawning area

Fisheries Science - The widely distributed East Asian Japanese eel Anguilla japonica constitutes a single genetically homogeneous population with a single spawning area near the West Mariana Ridge....     

Generation of recombinant bovine interferon tau in the human embryonic kidney cell line and its biological activity

The objective of this study was to generate recombinant bovine interferon tau (rbIFNT) in mammalian hosts. The complementary DNA encoding bovine IFNT2 was cloned for the construction of pRcRSV‐bIFNT2 expression vector. The expression vector was transfected to 293 cells. Transfected cells harboring expression vector were selected with G418. Highly expressing clonal line was adapted to serum‐free suspension culture in a spinner flask. The recombinant protein had 24 kDa apparent molecular mass, suggesting being expressed as a glycoprotein, and was purified from serum‐free conditioned medium by the combination of Diethylaminoethanol Sepharose ion exchange and Sephacryl S‐200 HR gel filtration. A total of 7.3 mg rbIFNT was obtained from 13.5 L conditioned medium. Generated rbIFNT was biologically active in terms of antiviral activity measured by the plaque inhibition assay with Madin‐Darby bovine kidney cells and the vesicular stomatitis virus. The recombinant protein was also utilized for immunization to raise antibodies in the rabbit. The generated antibody was capable of use in both Western blotting and the binding assay. The results in the present study suggest that a certain amount of rbIFNT is raised in mammalian hosts by using conventional plasmid vector and its antibody provides useful tools for studies in the biology of bovine IFNT.     

Experimental infection in specific-pathogen-free chicks with avian reovirus and avian nephritis virus isolated from broiler chicks showing runting syndrome

Avian reovirus (ARV) and avian nephritis virus (ANV) were individually isolated from runty 10-day-old broiler chicks. The ARV isolate, IR-R, the ANV isolate, IR-N, and the reference strain of ANV, G-4260, were inoculated orally into 1-day-old chicks of two specific-pathogen-free (SPF) chicken lines, 151 and PDL-1. Growth retardation without the presence of gross lesions was clearly observed at 7 and 14 days postinoculation (PI) in chicks of both lines inoculated with the IR-R strain. On the other hand, in chicks inoculated with IR-N strain, growth retardation was observed only in the chicks of line 151 at 7 and 14 days PI. Microscopically, nephritis was observed in both chicken lines at 7 and 14 days PI. When chicks that were inoculated with the IR-N strain at 1 day of age were inoculated with the IR-R strain at 3 days of age, growth retardation was observed in the chicks of line PDL-1 at 10 and 17 days PI. However, the growth retardation was less severe than in the group receiving a single inoculation of the IR-R strain.     

Morphologic study of inclusions in tissues from pigs inoculated with cytomegalovirus

Six 5-day-old gnotobiotic pigs inoculated intranasally with the J-1 strain of porcine cytomegalovirus (PCMV) were euthanatized within 9 to 18 days after inoculation. All pigs developed a subclinical form of PCMV infection and had characteristic intranuclear inclusions in all tissues. Morphologically, 2 types of inclusions were observed. One was a small herpetic intranuclear inclusion in reticuloendothelial cells, which contained a few nucleocapsids in the nucleus. The other was a typical cytomegalic intranuclear inclusion in macrophages in the lungs and in tubuloalveolar gland cells in the nasal mucosa. Inclusions contained many nucleocapsides in the nucleus and a large number of enveloped viral particles in the cytoplasm. The distribution of the specific immunofluorescent antigen of PCMV was coincident with the presence of herpetic and cytomegalic inclusions.     

Sequence comparison of the ORF 7 region of transmissible gastroenteritis viruses isolated in Japan

The 3' end region nucleotide sequence, including ORF7, of nine Japanese and two U.S.A. isolates of transmissible gastroenteritis virus (TGEV) were determined and compared. Nine Japanese TGEV strains have been isolated over the past 40 years (1956-1997). From the comparison of determined nucleotide sequences, we could divide the TGEV Japanese isolates into two groups and distinguish them from TGEV U.S.A. isolates.     

Myxoid leiomyosarcoma of the gizzard in a broiler chicken

A leiomyosarcoma was found in the gizzard of a 57-day-old female broiler chicken weighing 1.8 kg. Grossly, the tumor mass, 13.0 x 8.5 x 10.0 cm, enveloped the gizzard and had a gelatinous appearance due to the rich production of mucin. Miliary metastatic tumors were noted in the liver. Histopathologically, there was marked production of mucus throughout the tumor tissue, and densely or loosely arranged long spindle-shaped leiomyosarcoma cells proliferated. The tumor cells had a low rate of mitosis, showed slight cellular atypia, and, immunohistochemically, were positive for actin, alpha-smooth muscle actin, and desmin. Electron microscopically, various amounts of microfibrils with focal densities, dense patches, and basal plates were observed.     

Malignant fibrous histiocytoma in a Djungarian hamster

A subcutaneous malignant fibrous histiocytoma (MFH) was observed in the region between the right posterior trunk and right hind limb of a 2-year-old male Djungarian hamster weighing 45 g. Histologically, the tumor consisted of bizarre multinucleated giant cells, histiocytic cells, and fibroblastic cells with a storiform pattern, and was considered to be of the storiform-pleomorphic type of MFH. Severe nuclear atypia with prominent nucleoli and many mitotic figures was also observed. Electron microscopy demonstrated fibroblastic cells and histiocytic cells. The fibroblastic cells were spindle-shaped, and sometimes had an invaginated nucleus. The histiocytic cells were polygonal with an oval or kidney-shaped nucleus. The cytoplasm of both cells contained numerous free ribosomes, small amounts of rough endoplasmic reticulum, and round mitochondria. Tumor cells were immunohistochemically positive for vimentin, and were thought to be of undifferentiated mesenchymal cell origin. This is the first report of spontaneous MFH in a hamster.