Modification of three avian viruses passaged in Chinese hamster lung cells (Don) in pathogenicity to chicken embryo

The Beaudette 42 strain of avian infectious bronchitis virus, Sato strain of Newcastle disease virus, and Uchida strain of avian reovirus were passaged in Chinese hamster lung cells (Don), and some properties were examined. The Don-passaged strains showed a difference in replication in Don and chicken embryo kidney cells in one-step growth curve examinations and a partial modification in pathogenicity to chicken embryos; nevertheless, neutralization tests revealed no serological alteration.     

Immunohistochemical distribution of amyloid deposits in 25 cows diagnosed with systemic AA amyloidosis

The distribution of amyloid deposits was histopathologically and immunohistochemically examined in 25 cows aged 5 to 10 years that had been diagnosed with systemic AA amyloidosis. This examination revealed that amyloid deposits were also present in the hypophysis, ovary, uterus, mammary gland and skeletal muscle, in addition to the liver, kidney, spleen, pancreas, thyroid gland, adrenal gland, gastrointestinal mucosa, heart, lung and lymph nodes. The examined cows tended to have chronic inflammations, including chronic mastitis (six cases) or chronic pneumonia (four cases), which is thought of as a causative agent of AA amyloidosis. In contrast, five cases did not exhibit any chronic inflammation.     

A case of congenital hyperostosis in a newborn piglet

One female newborn piglet showed prominent thickening of both forelimbs and died soon after birth. Histopathologically, thin and woven trabeculae of bone was extending out from the edge of cortical bone in the affected forelimbs, and diagnosed as congenital hyperostosis. The extent of radially proliferated trabeculae was most prominent in radioulna. Many round- to spindle-shaped cells were observed in periosteum, which were considered to be osteoblasts. Around the periosteum, the mesenchymal proliferation was extensive with abundant mucus, and cartilaginous metaplastic changes were observed mainly around the radioulna and humerus. Dilatation of vessels with fibrin deposition in vessel walls was often observed, which were considered to reflect the localized circulatory disturbance.     

Histopathology of incidental findings in beagles used in toxicity studies

The purpose of our publication is to widely communicate the pictures of spontaneous findings occurring in beagles. Spontaneous arteritis occurs commonly in beagles. Frequent sites of arteritis are the heart, spleen, pancreas, epididymis and spinal cord. Morphological similarities between spontaneous and drug-induced arterial lesions may cause confusion when evaluating vascular toxicity of chemicals such as vasodilating agents. Focal and minimal inflammatory lesions are occasionally seen in the lung and may be associated with aspiration of food particles or of unknown causes. A cystic change with copious mucin production occurs occasionally in the mucosal epithelium of the gall bladder. Nesidioblastosis is seen rarely in the pancreas of beagles. C-cell complex and lymphocytic thyroiditis are common thyroid lesions. Spontaneous focal hypospermatogenesis and lobular Sertoli-cell-only seminiferous tubules occurring frequently in beagles must be distinguished from drug-induced damage of the seminiferous tubules in toxicity studies. The morphological differences of the female genital system in each cycle need to be understood; therefore, we present the normal features of the cyclic changes of the female genital organs. Further, we provide more information on spontaneous findings in beagles for exact diagnoses in toxicity studies.     

Detection of porcine circovirus 2 (PCV-2) DNA by nested PCR from formalin-fixed tissues of post-weaning multisystemic wasting syndrome (PMWS) pigs in Thailand

A retrospective study for the detection of porcine circovirus 2 (PCV-2) DNA was conducted by nested PCR method in 16 cases of swine post-weaning multisystemic wasting syndrome (PMWS) in Thailand. Histopathology showed characteristic lesions of PMWS and intracytoplasmic viral inclusion bodies in macrophages infiltrating in lymphoid tissues. PCV-2 DNA was detected from formalin-fixed and/or formalin-fixed paraffin-embedded tissues from all pigs with PMWS. The amplified products were digested with Hae III.     

Molecular characterization of Helicobacter pylori strains isolated from cynomolgus monkeys (M. fascicularis)

We recently reported the occurrence of natural infection with H. pylori in a group of cynomolgus monkeys with chronic active gastritis and gastric erosions. The goal of the present study was to characterize and to compare strains isolated from animals originating from two different geographical areas. Gross and microscopic pathology determined at the time of necropsy was similar in all animals. H. pylori were isolated from specimens harvested in five monkeys (four from Vietnam and one from the Philippines) with gastritis. Isolates from monkeys bred in Vietnam had a similar DNA fingerprint pattern, which was distinct from that of isolates from a monkey bred in the Philippines. All strains were of the s1a vacA subtype, but all the 'Vietnamese' strains were cagA+ and all but one were iceA1 whereas the 'Philippino' strains were cagA- and iceA2. The sequences of the 16S rRNA of the Vietnamese and Philippino strains shared 98% homology and both clustered with H. pylori sequences present in the NCBI database. In conclusion, cynomolgus monkeys can be naturally colonized by H. pylori, and the strains isolated from these animals appear to vary according to the geographical origin, thus indicating probable infection prior to importation. Since some of the cynomolgus monkeys developed antral erosions during natural infection, we propose that this animal model may be used to investigate the role of H. pylori in ulcerogenesis.     

Esophageal adenosquamous carcinoma in a cat

Esophageal carcinoma was observed in an eight-year-old, castrated male, Japanese domestic cat. Histologically, this neoplasm consisted of two different growth patterns, squamous cell carcinoma and adenocarcinoma. The results of immunohistochemical examination supported the fact that the two kinds of neoplastic cells have different characteristics. The tumor was, therefore, diagnosed as adenosquamous carcinoma. Esophageal tumors in the cat are very rare and, if any, neither adenocarcinoma nor adenosquamous carcinoma has been reported up to the present.     

Rapid methods for comparing the double-stranded RNA genome profiles of bluetongue virus

Various double-stranded RNA extraction procedures, gel electrophoresis systems, and methods to detect the RNA bands in the gel were investigated to find the most rapid methods to obtain the genome profiles of bluetongue virus in small volumes (1–25 ml) of infected cell culture fluids. Rapid double-stranded RNA extraction procedures coupled with staining the acrylamide gel slabs with ethidium bromide or silver nitrate resulted in well-defined genome profiles from bluetongue virus infected cell cultures in 6–48 h. Radioactive labelling of viral RNA with ³²P was time consuming, cumbersome and expensive. These techniques detect less than 0.5 μg of double-stranded RNA which can be obtained from one 1-ml well of a 24-well cluster plate of bluetongue virus infected cell monolayers. The methods were therefore suitable for rapid comparisons of the electropherotypes of multiple virus isolates.