Molecular cloning of canine nm23 cDNAs and their expression in normal and tumor tissues

Two canine nm-23 cDNAs, designated as nm23-C1 and -C2, were isolated and characterized. Both have a putative open reading frame consisting of 459-bp encoding 152 amino acids and are highly similar to human, mouse and rat homologues. To understand the potential role of nm23-C1 and -C2 in the development of mammary gland tumors (MGT), we analyzed the mRNA expression in 14 MGT samples by RT-PCR. The samples were divided into categories according to their histopathology (benign/malignant) and metastasis. No significant difference in the mRNA expression levels of either nm23-C1 or -C2 were observed between the benign and malignant groups or the metastatic and non-metastatic groups. These results suggest that nm23-C1 and -C2 are not related to the establishment of malignancy and metastatic lesions in canine MGT cases.     

Virulence characteristics of Yersinia pseudotuberculosis isolated from breeding monkeys in Japan

Between April 2001 and 2007, 18 Yersinia pseudotuberculosis outbreaks occurred in breeding monkeys at 12 zoological gardens in Japan, and 28 monkeys of 8 species died. A total of 18 Y. pseudotuberculosis strains from the dead monkeys, comprising one strain per outbreak, were examined for serotype and the presence of the virulence genes virF, inv, ypm (ypmA, ypmB and ypmC) and irp2. Of the 18 Y. pseudotuberculosis strains, 7 (38.9%) were serotype 4b, 7 (38.9%) were serotype 1b, and there was one each of serotypes 2b, 3, 6 and 7. All the 18 strains examined harbored virF and inv. Sixteen (88.9%) strains, including the strain of serotype 7, harbored ypmA. However, no strain harbored ypmB, ypmC and irp2.

This study demonstrated that among other pathogenic factors, almost all the Y. pseudotuberculosis isolated from the outbreaks had the ypm gene encoding the superantigenic toxin, YPM. As most of the monkeys who died in those outbreaks originated from South America and other regions, where the presence of the ypm gene have not been reported, YPM might be the cause, or at least the most important factor for, the high mortality of the breeding monkeys infected by Y. pseudotuberculosis in Japan. This is also the first report of a fatal case due to Y. pseudotuberculosis serotype 7 infection in the world.     

Intracranial meningioma with polygonal granular cell appearance in a Chihuahua

A menigioma with polygonal granular cell proliferation in an 11-year and 8-month-old male Chihuahua is described. The tumor was observed under the dura matter of the right cerebrum. Microscopically, the tumor consisted of solid growth foci of small- or large- sized polygonal cells, with pale-stained nuclei, prominent nucleoli, and fine granular to foamy eosinophilic cytoplasm. Some of the proliferating cells contained variable amounts of cytoplasmic PAS-positive granules. Immunohistochemical analysis revealed that neoplastic cells were positive for vimentin and S-100 protein. Ultrastructurally, the neoplastic cells contained vesicular structures with a few small round-shaped bodies in the cytoplasm. We diagnosed the case as canine meningioma with granular cell appearance.     

Multi-voxel magnetic resonance spectroscopy of cerebral metabolites in healthy dogs at 1.5 Tesla

This study was conducted to measure the difference in levels of cerebral metabolites in the right and left hemispheres, gray (GM) and white matter (WM), imaging planes, and anatomical regions of healthy dogs to establish normal variations. Eight male Beagle dogs (1 to 4 years of age; mean age, 2 years) with no evidence of neurologic disease were studied. Using the multi-voxel technique on a 1.5 Tesla magnetic resonance imaging scanner, metabolite values (N-acetyl aspartate [NAA], choline [Cho], creatine [Cr]) were obtained from the frontoparietal WM, parietal GM, temporal GM, occipital GM, thalamus, cerebellum, mid-brain, and pons. There was no significant difference in levels of these metabolites between the right and left in any locations or between the GM and WM in the cerebral hemispheres. However, there were significant differences in metabolite ratios within imaging planes. The NAA/Cr was lower in the cerebellum than other regions and the thalamus had a higher Cho/Cr and lower NAA/Cho ratio than in other regions. The spectral and metabolic values will provide a useful internal reference for clinical practice and research involving multi-voxel magnetic resonance spectroscopy. Measurement of metabolite values in the transverse plane is recommended for comparing levels of regional metabolites.     

Spontaneous Harderian Gland Adenocarcinoma in a Female F344 Rat: A Case Report

Harderian gland tumors are extremely rare in female F344 rats. An expansive enlarging lesion of the Harderian gland with compression, distortion and invasion of the surrounding muscle was found in a 110-week-old female F344/DuCrj rat, which was diagnosed as a Harderian gland adenocarcinoma. Epithelial growth patterns such as glandular, lobular, papillary and duct forming patterns were exhibited in most areas of the tumor. The tumor cells were pleomorphic and atypical. In one part of the tumor, poorly differentiated areas were found. This case was observed in the middle dose group of a carcinogenicity study of diphenylamine, which was not carcinogenic, we determine to be this case was a spontaneous tumor.     

Molecular characterization of avian polyomavirus isolated from psittacine birds based on the whole genome sequence analysis

Seven avian polyomaviruses (APVs) were isolated from seven psittacine birds of four species. Their whole genome sequences were genetically analyzed. Comparing with the sequence of BFDV1 strain, nucleotide substitutions in the sequences of seven APV isolates were found at 63 loci and a high level of conservation of amino acid sequence in each viral protein (VP1, VP2, VP3, VP4, and t/T antigen) was predicted. An A-to-T nucleotide substitution was observed in non-control region of all seven APV sequences in comparison with BFDV1 strain. Two C-to-T nucleotide substitutions were also detected in non-coding regions of one isolate. A phylogenetic analysis of the whole genome sequences indicated that the sequences from the same species of bird were closely related. APV has been reported to have distinct tropism for cell cultures of various avian species. The present study indicated that a single amino acid substitution at position 221 in VP2 was essential for propagating in chicken embryonic fibroblast culture and this substitution was promoted by propagation on budgerigar embryonic fibroblast culture. For two isolates, three serial amino acids appeared to be deleted in VP4. However, this deletion had little effect on virus propagation.     

Tyrosinase inhibitor from black rice bran

The inhibitor of tyrosinase activity in black rice bran was investigated. The methanol extract from black rice bran was re-extracted with hexane, chloroform, ethyl acetate, or water. The ethyl acetate extract had the most potent inhibition against tyrosinase activity by 80.5% at a concentration of 0.4 mg/mL. Inhibitory compound in the ethyl acetate fraction was isolated by silica gel column chromatography, and identified as protocatechuic acid methyl ester (compound 1) by GC, GC-MS, IR, and 1H and 13C NMR spectroscopy. Compound 1 inhibited 75.4% of tyrosinase activity at a concentration of 0.50 micromol/mL. ID(50) (50% inhibition dose) value of compound 1 was 0.28 micromol/mL. To study the structure-activity relationship, protocatechuic acid (2), vanillic acid (3), vanillic acid methyl ester (4), isovanillic acid (5), isovanillic acid methyl ester (6), veratric acid (7), and veratric acid methyl ester (8) were also assayed.