Molecular cloning of feline lung resistance-related protein (LRP) cDNA and its expression in a feline lymphoma cell line and adriamycin-resistant subline

Molecular cloning of feline lung resistance-related protein (LRP) was performed to evaluate the relationship between its expression level and drug resistance against chemotherapeutics. The nucleotide sequence of the coding region of feline LRP cDNA was found to be 2670-bp long and to show 84.2-92.6% homology to its human, mouse, and rat counterparts. The expression level of feline LRP mRNA was relatively high in lung, jejunum, and colon. An adriamycin (ADM)-resistant feline lymphoma subline, FT-1/ADM, showed a high level of MDR1 mRNA expression compared with parental FT-1 cells. However, no relationship was observed between the drug-resistant phenotype and the LRP mRNA expression level. Although no direct contribution of LRP to the development of the drug-resistant phenotype was observed, further investigation is advisable.     

Acidic soil conditions suppress zoospore release from zoosporangia in <Emphasis Type="Italic">Olpidium virulentus</Emphasis>

Lettuce big-vein disease, caused by Mirafiori lettuce big-vein virus and Lettuce big-vein associated virus, is suppressed when the pH of field soil becomes acidic. Therefore, we evaluated the effect of soil pH on the activities of Olpidium virulentus, the vector of the viruses. We found that acidic soil, pH less than 6.0, significantly reduced O. virulentus infection of the root and influenced the detection rate of zoospores released in the surrounding water. We concluded that acidic soil suppresses zoospore release from zoosporangia.     

Extension of the culture period for the in vitro growth of bovine oocytes in the presence of bone morphogenetic protein‐4 increases oocyte diameter,but impairs subsequent developmental competence

Bone morphogenetic protein‐4 (BMP‐4) inhibits luteinization of granulosa cells during in vitro growth (IVG) culture of bovine oocytes; however, oocytes derived from a 12 day IVG were less competent for development than in vivo‐grown oocytes. We herein investigated whether an extended IVG culture with BMP‐4 improves oocyte growth and development to blastocysts after in vitro fertilization. Oocyte‐granulosa cell complexes (OGCs) were cultured for 14 or 16 days with BMP‐4 (10 ng/mL), while a 12 day culture with BMP‐4 served as the in vitro control. OGC viability was maintained for the 16 day culture with BMP‐4 (83.2%), but was significantly lower without BMP‐4 (58.9%) than the control (83.0%). Prolong‐cultured oocytes at 16 days had statistically greater diameter (114.6 μm) than the control (111.7 μm). IVG oocytes with BMP‐4 for the 16 day culture had a similar nuclear maturation rate to the control (approximately 67%); however, blastocyst rates in BMP‐4 treated oocytes of 14 (1.8%) and 16 day (0%) IVG were statistically lower than that of 12 day IVG (9.0%). In conclusion, BMP‐4 maintained OGC viability and promoted oocyte growth in a prolonged culture, but impaired the developmental competence of oocytes. Prolonged culture may not be an appropriate strategy for enhancing the developmental competence of IVG oocytes.     

Properties of L-type bovine spongiform encephalopathy in intraspecies passages

The origin and transmission routes of atypical bovine spongiform encephalopathy (BSE) remain unclear. To assess whether the biological and biochemical characteristics of atypical L-type BSE detected in Japanese cattle (BSE/JP24) are conserved during serial passages within a single host, 3 calves were inoculated intracerebrally with a brain homogenate prepared from first-passaged BSE/JP24-affected cattle. Detailed immunohistochemical and neuropathologic analysis of the brains of second-passaged animals, which had developed the disease and survived for an average of 16 months after inoculation, revealed distribution of spongiform changes and disease-associated prion protein (PrP(Sc)) throughout the brain. Although immunolabeled PrP(Sc) obtained from brain tissue was characterized by the presence of PrP plaques and diffuse synaptic granular accumulations, no stellate-type deposits were detected. Western blot analysis suggested no obvious differences in PrP(Sc) molecular mass or glycoform pattern in the brains of first- and second-passaged cattle. These findings suggest failures to identify differences in mean incubation period and biochemical and neuropathologic properties of the BSE/JP24 prion between the first and second passages in cattle.     

Listeriosis in a raccoon dog (Nyctereutes procyonoides) associated with canine distemper

A wild raccoon dog (Nyctereutes procyonoides) that manifested severe illness and died was examined. Necropsy revealed severe emaciation, systemic icterus and petechial hemorrhages on the mucous membranes. Histopathologically, necroses were seen in the liver and brain stem associated with meningitis. Eosinophilic intranuclear inclusion bodies were observed in the spleen and intestinal mucosa, and eosinophilic intracytoplasmic inclusion bodies were seen in transitional epithelium in the bladder. Listeria monocytogenes 4b was isolated from the liver, spleen, kidneys and lungs, and the pathogen was also detected in the liver and brain stem immunohistopathologically. The disease was diagnosed as listeriosis associated with canine distemper virus infection in a raccoon dog.     

An occurrence of Salmonella typhimurium infection in sika deer (Cervus nippon)

Seven sika deer (Cervus nippon) in a herd of 30 deer in a park died. Upon examination of three dead deer, Salmonella Typhimurium was isolated from the organs and intestinal contents. Histopathological examination revealed catarrhal enteritis and focal necroses in the liver. Immunohistochemically, Salmonella antigen of O4 was detected in the enteric lesions. The case was diagnosed as S. Typhimurium infection in the sika deer. Because of the importance of Salmonella in public health, fecal and soil samples were continuously collected from the paddock. However, no Salmonella was isolated from any samples collected after medication of the deer and thorough disinfection of the immediate environment.     

Survey of ixodid tick species on domestic cats in Japan

Various species of ixodid ticks, attached to domestic cats in Japan, were identified in spring (April to June) and autumn (September to November). In the spring, a total of 282 ticks, including 61 larvae, 70 nymphs, 127 females and 24 males were collected from 126 cats. Of these, 264 were identified up to the species level. In the spring, Haemaphysalis longicornis was the most frequently (39.7%, 50/126) found tick species on feline hosts, followed by Ixodes ovatus (35.0%, 44/126), Ixodes nipponensis (15.9%, 20/126) and Haemaphysalis flava (9.5%, 12/126). Small numbers of Haemaphysalis megaspinosa, Haemaphysalis japonica, Ixodes persulcatus, Ixodes granulatus and Amblyomma testudinarium were also recovered. H. longicornis was the most frequently found tick species on cats around riversides or river basins, while I. ovatus and I. nipponensis were more frequently found on cats kept near woodland or related areas. I. nipponensis was more frequently found on castrated males. No major statistical differences in the frequency of tick attachment among sex, age or hair length for the three major tick species were found. Of 205 ticks including 173 (84.4%) larvae, 27 (13.2%) nymphs, 4 (2.0%) females and 1 (0.5%) male recovered from 62 cats in autumn, only 32 (15.6%) were identified. Most of the larvae were fully- or partly-engorged Haemaphysalis spp., and it was difficult to identify them further by morphological characterization.     

Infection frequency of mature apple fruit with Erwinia amylovora deposited on pedicels and its survival in the fruit stored at low temperature

The infection frequency of mature apple fruit by Erwinia amylovora and the survival of E. amylovora in the fruit stored at low temperature were investigated. The fruit stems (pedicels) of 460 mature apple fruit were inoculated with 10⁵ or 10⁴ cfu of bioluminescent E. amylovora, tagged with lux genes. Nine days after inoculation, 43% and 27% of the fruit inoculated with 10⁵ and 10⁴ cfu, respectively, were infected. All infected fruit looked healthy. After 6 months of storage at 5°C, almost all of the 142 infected fruit had viable E. amylovora. Of the fruit containing E. amylovora internally, 19.5% had latent infections and the rest had blight symptoms. E. amylovora was not uniformly distributed in the fruit flesh, and internal brown lesions were observed where E. amylovora was densely distributed. These findings showed that mature apple fruit may be infected with E. amylovora, especially as latent infections, and act as a source for long-range dissemination.     

Antibabesial activity of protoberberine alkaloids and 20-hydroxyecdysone from Arcangelisia flava against Babesia gibsoni in culture

Bioassay-guided fractionation of the boiled extract from the stems of Arcangelisia flava led to the isolation of palmatine (1), berberine (2), jatrorrhizine (3), dihydroberberine (4) and 20-hydroxyecdysone (5). The chemical structures of these compounds were elucidated on the basis of their chemical and spectral evidence. The isolated compounds were evaluated for their growth inhibiting effects on Babesia gibsoni in culture for a week. Compounds (1-4) showed significant inhibitions at concentrations from 100 to 1.0 microg/ml, while compound 5 at a concentration of 100 microg/ml, only.