Histopathological, immunohistochemical and ultrastructural studies of a renal mesenchymal tumor in a young beagle dog

A 15-month-old male beagle dog used in a toxicity study had a primary renal mesenchymal tumor. Macroscopically, the tumor was a gray-white mass which was found in the right kidney, and extended from the capsule to a position slightly compressing the medulla. Microscopically, most of the tumor cells showed a myxoid pattern, in which the matrix was positive for alcian blue staining. In the other parts of the tumor, a fascicular and wavy pattern was observed, and the matrix was full of collagen fibrils. Immunohistochemically, tumor cells were positive for vimentin and fibronectin, and negative for cytokeratin, desmin, α-smooth muscle actin, Von Willebrand factor, cyclooxigenase-2 and myelin basic protein. As a result, we diagnosed this case to be a renal mesenchymal tumor. Based on the microscopic findings, interstitial characteristics and immunohistochemical features, the present case was classified as a congenital mesoblastic tumor.     

Characterization of lignin-derived products from various lignocellulosics as treated by semi-flow hot-compressed water

To elucidate the decomposition behaviors of lignin from different taxonomic groups, five different lignocellulosics were treated with hot-compressed water (230 °C/10 MPa/15 min) to fractionate lignins into water-soluble portions, precipitates, and insoluble residues. The lignin-derived products in each fraction were characterized and compared. The delignification of monocotyledons [nipa palm (Nypa fruticans) frond, rice (Oryza sativa) straw, and corn (Zea mays) cob] was more extensive than that achieved for Japanese cedar (Cryptomeria japonica, gymnosperm) and Japanese beech (Fagus crenata, dicotyledon angiosperm). The water-soluble portions contained lignin monomers like coniferyl alcohol and phenolic acids, while the precipitates contained higher molecular weight lignin with high content of ether-type linkages. Lignin in the insoluble residues was rich in condensed-type structures. In all five lignocellulosics, ether-type linkages were preferentially cleaved, while condensed-type lignin showed resistance to hot-compressed water. In the monocotyledons, lignin–carbohydrate complexes were cleaved and gave lignins that had higher molecular weights than those eluted from the woods. These differences would facilitate the delignification in monocotyledons. Such information provides useful information for efficient utilization of various lignocellulosics.     

Neurotropism of the 1997 Hong Kong H5N1 influenza virus in mice

The direct transmission of H5N1 influenza A viruses from chickens to humans in Hong Kong in 1997 emphasized the need to have information on the pathogenesis of avian influenza virus infection in mammals. H5N1 influenza viruses isolated from patients during the incident killed experimentally infected mice. The principal lesions of the mice were broncho-interstitial pneumonia and nonsuppurative encephalitis. Infectious viruses and/or viral antigens were detected in the brain as well as in the trigeminal and vagal ganglia but not in the blood of the mice. These findings suggest that the virus reached the brain through the vagus and/or trigeminal nerves following replication in the respiratory mucosa. The results imply that neurotropism of the H5N1 virus in mice is a novel characteristic in the pathogenesis of infection by human influenza virus isolates.     

Molecular cloning of canine monoamine oxidase subtypes A (MAOA) and B (MAOB) cDNAs and their expression in the brain

The role of monoamine oxidase has been shown to be related to some behavioral changes including aggression and cognitive dysfunction. In order to demonstrate the basic expression patterns of monoamine oxidase in the canine brain, we determined the full-length nucleotide sequences of cDNA for canine monoamine oxidase type A (MAOA) and type B (MAOB) genes that were isolated from the canine brain cDNA library. Oligonucleotide primers for PCR were constructed based on the conserved sequences reported thus far for other mammalian species. The nucleotide sequences had open reading frames of 1584 and 1563 bp for MAOA and MAOB, respectively. Both of these genes showed relatively high homology with other species in both nucleotide (> 81%) and deduced amino acid (> 85%) sequences. In Northern blot analyses MAOA mRNA was expressed broadly in various parts of the canine brain, whereas MAOB mRNA was found only in specific brain regions, such as the hypothalamus, hippocampus, brain stem and olfactory bulb. These results suggest that MAOA and MAOB mRNAs have subtype-specific expression patterns in the canine brain.     

Protective effects of intranasal vaccination with plasmid encoding pseudorabies virus glycoprotein B in mice

Intranasal administration of plasmid DNA encoding glycoprotein B of pseudorabies virus into mice induced both serum and secretory antibody responses. These mice resisted intranasal challenge with lethal dose of the virus, but did not intraperitoneal challenge. On the other hand, intramuscular injection of the plasmid induced less secretory and higher serum antibody responses than those of intranasally vaccinated mice. None of them was protected from virus challenge. The present results suggest that administration of plasmid DNA encoding glycoprotein B by respiratory mucosal route generates local secretory antibodies which serve to protect animals from pseudorabies virus infection.     

Molecular epidemiology of VapA-positive Rhodococcus equi in thoroughbred horses in Kagoshima,Japan

The prevalence of virulent R. equi having 15- to 17-kDa antigens (VapA) in fecal isolates from 13 thoroughbred foals and their dams on 5 farms in Kagoshima, Japan, and the plasmid profiles of VapA-positive isolates by restriction fragment digestion patterns were investigated to compare the genotypic variation among virulence plasmids of R. equi isolates from Japan. In total, 218 (24.6%) of 886 isolates from the feces of the 13 foals and 13 (12.5%) of 104 isolates from the feces of their dams demonstrated VapA-positive R. equi. Plasmid DNA preparations of 231 virulent isolates from foals and dams were analyzed by restriction enzyme digestion with endonucleases EcoRI, EcoT22I and HindIII and were divided into 3 types: 172 isolates contained a 90-kb type I plasmid, 57 contained a 90-kb type III plasmid and 2 contained a 90-kb type IV plasmid. This study demonstrates a geographic character in the distribution of virulence plasmids found in VapA-positive isolates from thoroughbred foals in Kagoshima.     

Measurement of peptidase activity and evaluation of effectiveness of administration of minocycline for treatment of dogs with periodontitis

OBJECTIVE: To determine clinical, enzymatic, and microbiologic effects of controlled-release localized administration of minocycline on dogs with periodontitis. ANIMALS: Five adult Beagles with periodontitis. PROCEDURE: After tooth scaling and root planing, 2 treatment, 1 placebo, and 1 control site were selected for each dog. Treatment sites (n = 10) received a periodontal formulation of minocycline hydrochloride, placebo sites (5) received ointment without minocycline, and control sites (5) did not receive ointment. Treatments were administered 4 times at weekly intervals. Peptidase activity and clinical and microbiologic effects were evaluated and compared among sites for 17 weeks. RESULTS: Bleeding of the gums on probing (BOP) and pocket depth (PD) improved at the treatment site and were maintained for 13 weeks after treatment. However, BOP and PD in placebo and control sites increased from weeks 9 to 17 Peptidase activity in the periodontal pocket decreased noticeably from week 1 to 17, compared with baseline values for the treatment site. However, peptidase activity for placebo and control sites increased and were above baseline values on week 9 and week 13, respectively. Total bacterial counts decreased by 90% for treatment sites and remained at that value for 13 weeks. However, for placebo and control sites, bacterial counts increased and reached the baseline value on week 17. CONCLUSIONS AND CLINICAL RELEVANCE: Increased peptidase activity is correlated with the progression of periodontitis in dogs. Treatment with minocycline, using a localized delivery system, was effective in dogs for at least 13 weeks after cessation of drug administration.     

Measurement of porcine luteinizing hormone concentration in blood by time-resolved fluoroimmunoassay

We validated a time-resolved fluoroimmunoassay (TR-FIA) using the lanthanide element europium as a non-radiological tracer for measuring luteinizing hormone (LH) in porcine peripheral blood. The dose-response curve of the reference standard ranged from 0.2048 to 50 ng/ml. Good parallelism was noted between the LH standard and plasma sample. The profile of LH throughout the estrous cycle, assessed by daily blood sampling, was consistent with the previous findings obtained by radioimmunoassays (RIAs). Moreover, the secretory patterns of pulsatile LH in the follicular phase and the preovulatory LH surge were also similar to those obtained in previous RIAs. We conclude that TR-FIA can be used to measure LH levels in porcine blood, with practical and convenient applications.