The Food Safety Commission (FSC) of Japan, established in July 2003, has its own initiative to conduct risk assessments on food stuffs known as “self-tasking assessment”. Within this framework, the FSC decided to conduct a risk assessment of beef and beef offal imported into Japan from countries with no previous BSE reports; thus, a methodology was formed to suit to this purpose. This methodology was partly based on the previous assessments of Japanese domestic beef and beef imported from U.S.A./Canada, but some modifications were made. Other organizations’ assessment methods, such as those used for BSE status assessment in live cattle by the OIE and EFSA’s GBR, were also consulted. In this review, the authors introduce this alternative methodology, which reflects (1) the risk of live cattle in the assessed country including temporal risks of BSE invasion and domestic propagation, with the assessment results verified by surveillance data, and (2) the risk of beef and beef offal consisting of cumulative BSE risk by types of slaughtering and meat production processes implemented and the status of mechanically recovered meat production. Other possible influencing factors such as atypical BSE cases were also reviewed. The key characteristic of the current assessment is a combination of the time-sequential risk level of live cattle and qualitative risk level of meat production at present in an assessed country.
In this study, we investigated diabetic stage dependent cyclooxygenase-2 (COX-2) immunoreactivity in the dentate gyrus in streptozotocin (STZ)-induced type 1 diabetic rats. The animals were sacrificed at 2, 3 and 4 weeks after STZ treatment. Blood glucose levels were increased after STZ treatment. COX-2 immunoreactivity in dentate gyrus was significantly increased in these regions 3 weeks after STZ treatment and restored to its basal level to 4 weeks after STZ treatment. In contrast, COX-2 immunoreactivity was not changed in CA3 region in all groups. These results suggest that STZ-induced type 1 diabetes transiently, but not permanently, decreased synaptic transmission and plasticity 3 weeks after STZ treatment in the dentate gyrus.
Nine fowl adenoviruses (FAdVs) isolated from chickens with inclusion body hepatitis (IBH) in Japan from 2009 to 2010 were characterized serologically and genetically. These isolates were all neutralized by antisera against the SR-48 strain (FAdV-2). Phylogenetic analysis based on the part of the hexon gene that included the L1 region revealed that all isolates were almost identical except one isolate in 2009. This suggests a common ancestor for the FAdVs obtained from chickens with IBH in Japan in 2010.
Haemophilus parasuis is known to produce a group of virulence-associated autotransporter (AT) proteins, VtaAs; however, no other ATs have been characterized yet. On the basis of the reported sequence of a putative espP2 gene for extracellular serine protease (ESP)-like protein of H. parasuis, this putative AT gene was successfully amplified from H. parasuis serotype 5 field strain HPS0819, cloned and sequenced. The confirmed ORF sequence showed 100% identity with the reported putative espP2 gene. The recombinant ESP-like protein purified from Escherichia coli with a pET expression system was used for immunological characterization. An approximately 85 kDa antigen was detected in cultured H. parasuis by using antiserum to the purified ESP-like protein, and antibodies against the recombinant ESP-like protein were detected in a selected serum from pigs with experimental H. parasuis infection. The results indicated that H. parasuis could produce ESP-like protein in vitro and in vivo. In an immune protection study using guinea pigs, 6 out of 10 animals immunized with the recombinant ESP-like protein survived after challenge with 5 × 109 bacteria of strain HPS0819, whereas 7 out of 10 animals immunized with formalin-inactivated H0819 bacterin survived after challenge. The results suggest that ESP-like protein could be one of the vaccine antigen candidates for H. parasuis infection.
We evaluated effect of enterotoxigenic Escherichia coli (ETEC) specific lytic phage CJ12 in ETEC infected pigs. Phage was mixed with feed at a ratio of 1:1,000 (0.1%). One week after initially providing phage mixed feed, pigs were challenged orally with 1011 CFU of ETEC and body weight, diarrhea score, bacterial CFU and phage PFU in the feces were measured. Pigs of phage treated groups C (106 PFU/g) and D (108 PFU/g) showed more resistance to diarrhea due to ETEC infection compared to positive control group B on the third day after the initial challenge. Moreover, during the quantitation of ETEC in feces, both groups C and D showed approximately 63.92 and 60.73% reduced ETEC compared to positive control group B. Phages were successfully isolated from feces in both groups C and D during the experiment without any adverse effects, suggesting the possibility of using CJ12 as a feed additive.
The mechanisms of abortion and sterility induced by bacterial infection are largely unknown. In the present study, we found that Brucella abortus, a causative agent of brucellosis and facultative intracellular pathogen, caused sterility in pregnant mice. We have recently established a mouse model for abortion induced by B. abortus infection and high rates of abortion are observed for bacterial infection on day 4.5 of gestation, but not for other days. Infected newborn (first generation) mice showed poor growth compared with uninfected newborn mice and bacterial replication in the spleen of the former was observed over a long period. When infected first generation female mice were mated to infected first generation male mice, the number of fetuses was significantly less than that in uninfected first generation mice. These infected second generation mice also showed poor growth. These results suggest that vertical transmission of B. abostus causes sterility in pregnant mice and our mouse model would be useful for the investigating of brucellosis.
The in vitro activity of 15 antimicrobial agents against clinical isolates of Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Pasteurella spp. and Streptococcus canis from dogs was investigated. For Staphylococcus spp., the highest frequency of resistance was observed for penicillin, followed by ampicillin, tetracycline and chloramphenicol. The highest frequency of resistance in E. coli isolates was recorded for tetracycline and streptomycin. Pasteurella spp. and S. canis had the highest resistance rate for tetracycline and chloramphenicol. Most isolates showed full susceptibility to low-level resistance to colistin, florfenicol and fluoroquinolones. Further studies using larger number of isolates from both healthy and diseased dogs would provide a broader picture of antimicrobial resistance at a national level and promote prudent use of antimicrobial agents in companion animals.
A male Queensland koala (Phascolarctos cinereus adustus) at Kanazawa Zoological Gardens (Kanagawa, Japan) exhibited paralytic symptoms in the hind limbs. Computed tomography and magnetic resonance imaging revealed a mass on the left ventral side of the 11th to 13th thoracic vertebrae, and the presence of myelitis or edema in the spinal cord. The koala was under anesthesia during the examination and suddenly developed ventricular fibrillation and died. Necropsy revealed a firm flat ovoid hemorrhagic mass on the vertebrae. Following a microscopic examination including immunohistochemistry, the perivertebral mass was diagnosed as B cell lymphoma. Therefore, neoplastic cell infiltration into the spinal cord may cause paralytic symptoms in the hind limbs.
A Japanese domestic long-hair cat of about 8 years of age was presented with vomiting and hematochezia and was found to have significant hypereosinophilia. Bone marrow aspiration revealed moderate increases of eosinophilic lineages. Histopathological examination revealed mild eosinophilic and epitheliotropic T-lymphocytic infiltrations in the duodenum. Although the cat remained asymptomatic with only prednisolone administration, the cat presented with hematemesis, weight loss, and severe anorexia 512 days after the initial presentation. Subsequently, gastrointestinal perforation developed, and the cat died on Day 536. Histopathological examination of autopsy specimens revealed mixed cellular infiltration including eosinophils and neoplastic lymphocytes in the intestinal lymph nodes, intestine, liver, spleen, and pancreas. Immunohistochemical examination supports a diagnosis of intestinal T-cell lymphoma with severe hypereosinophilic syndrome.
Although the susceptibility of dermatophytes to antifungal drugs is well documented in humans, the effectiveness in animals has not been previously investigated. The in vitro susceptibility of 54 clinical isolates from animal dermatophytoses to ketoconazole (KTZ), itaconazole (ITZ) and terbinafine (TFN) was measured using microdilution assay (CLSI M38-A2 test) and by the E-test (KTZ and ITZ). All 3 drugs showed antifungal activity, while KTZ displayed the broadest minimum inhibition concentration (MIC) range (0.125–16 μg/ml) against M. canis and M. gypseum. The MIC of KTZ and ITZ was almost the same for human and animal isolates of T. mentagrophytes and T. rubrum. The MIC of TFN was almost the same for dermatophytes isolated from humans and animals.
To assess the relationship between pH and temperature in the ruminal bottom fluid, circadian changes were monitored using cows fed a control diet (C diet) or a rumen acidosis-inducing diet (RAI diet) by using a wireless radio-transmission pH- measurement system. These two parameters were measured simultaneously at 10-min intervals on day 14 after commencement of feeding. Compared to the mean ruminal pH for 60 min immediately after the morning feeding (0 hr), significantly lower pH was noted 3–13 hr later (P<0.05) and 4–19 hr later (P<0.01) in cows fed the C and RAI diets, respectively, although the reduction in the latter was much higher than that in the former. In contrast, significantly higher ruminal temperature was found at 8 and 12–14 hr later (P<0.05) and 6, 8, and 10–19 hr later (P<0.01) in cows fed the C and RAI diets, respectively. A significant negative correlation was observed between the lowest ruminal pH and its corresponding ruminal temperature in cows fed the C and RAI diets (r=-0.722 and -0.650, P<0.01, respectively), suggesting active fermentation and volatile fatty acid production in the rumen. However, ruminal pH profiles may not be predictable by measuring only ruminal temperature because decreases in ruminal pH were preceded by increases in ruminal temperature, and circadian changes in pH and temperature were associated with ruminal fermentation.
House dust mite (HDM) allergens are the most common allergens for induction of IgE-mediated hypersensitivity. Recently, epicutaneous sensitization with HDM allergens has been emphasized in the development of atopic dermatitis (AD) by producing various soluble factors in keratinocytes. Among the soluble factors, GM-CSF is a key molecule that activates Langerhans cells, antigen-presenting cells in the epidermis. In the present study, we investigated the effects of Dermatophagoides farinae (Der f) on GM-CSF production in a canine keratinocyte cell line, CPEK. CPEKs were found to produce GM-CSF upon stimulation by Der f. The GM-CSF production was suppressed by addition of a cysteine protease inhibitor. The present results suggest that cysteine protease-derived Der f may be an initiator of allergic inflammation by inducing the production of GM-CSF in keratinocytes.
Prevalence of equine gastric ulcer syndrome in 85 young Thoroughbreds was investigated. The presence of gastric ulcers was confirmed in 27.1% (23/85) of the horses by endoscopic examination. Sixty-two horses without gastric ulcers were allocated randomly to either the treated group (31 horses) or sham-dosed control group (31 horses) in order to investigate the efficacy of omeprazole oral paste in the prevention of gastric ulcers. At the second endoscopic examination conducted after 28 days of administration, only 1 horse in the treated group developed gastric ulcers, while 12 horses developed gastric ulcers in the control group. Based on these data, the efficacy of omeprazole in prevention of equine gastric ulcers in young Thoroughbreds during the training period was confirmed.
Stem cell based cell therapies offer significant potential for the field of regenerative medicine. Human amniotic fluid stem cells (hAFSCs) are an attractive source for lineage-specific differentiated stem cell therapy since they have properties that are able to differentiate into cells representing all three germ layers. To better understand the fate and location of implanted hAFSCs, a means to monitor cells in living subjects is essential. Here, we showed that differentiated cells, such as neurogenic, endothelial, and myogenic cells, derived from hAFSCs can be effectively labeled by the FITC-incorporated silica-coated nanoparticles, MNPs@SiO2 (FITC), although the labeling efficacy and cytotoxicity were distinct depending on the differentiated cell type. In addition, we observed that MNPs@SiO2-labeled cells provided sufficient signals for detection by optical and confocal microscope imaging when transplanted into the mice. These results suggest that the fluorescent dye incorporated MNPs@SiO2 are a useful tool for the cell labeling and in vivo tracking of differentiated cells derived from hAFSCs.
Growth deficit (gd) is a recessive mutation that occurs spontaneously in the inbred NC/Sgn mouse strain. Because homozygotes (gd/gd) of both sexes are sterile, they must be produced by mating putative heterozygous carriers (+/gd) whose phenotypes are essentially the same as those of wild-type +/+ mice. The objectives of this study were to develop an efficient method that distinguished a gd allele from a wild-type allele and, if possible, to identify nucleotide substitutions responsible for the gd mutation. The location of the gd locus was estimated to be at 58.3 Mbp on chromosome 4, over which Musk is located. An A-to-G base substitution, which resulted in an M826V amino acid exchange, was identified within a tyrosine kinase domain of Musk. This base substitution disrupted a recognition site for NlaIII; this allowed for discriminating the gd allele from the wild-type allele using PCR-RFLP analysis. When 130 (C57BL/6J × NC/Sgn-gd) F2 mice were genotyped by PCR-RFLP analysis, all 32 growth-retarded F2 mice were judged to have the gd/gd genotype. Musk mutations are known to cause congenital myasthenia, which is accompanied by growth retardation, postnatal lethality, and development of a hunchback. These were the typical phenotypes of gd/gd mutants. Although we cannot rule out the possibility that the neighboring genes around the Musk locus are related to the gd phenotype, gd could possibly be classified as a mutant allele of Musk.
Mycoplasma species identification is based on biochemical, immunological, and molecular methods that require several days for accurate identification. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a novel method for identification of bacteria and has recently been introduced into the clinical microbiology laboratory as a rapid and accurate technique. This method allows a characteristic mass spectral fingerprint to be obtained from whole inactivated mycoplasmal cells. In this study, we evaluated the performance of the MALDI-TOF MS for the identification of Mycoplasma by comparison with standard sequence analysis of 16S rRNA. We developed the first database of MALDI-TOF MS profiles of Mycoplasma species, containing Mycoplasma pulmonis, M. arthritidis, and M. neurolyticum, which are the most common pathogens in mice and/or rats, and species-specific spectra were recorded. Using the database, 6 clinical isolates were identified. Six tracheal swabs from 4 mice and 2 rats were cultured on PPLO agar for 4 to 7 days, and the colonies were directly applied to analyze the protein profiles. Five strains were identified as M. pulmonis, and 1 strain from a mouse was identified as M. neurolyticum (spectral scores were >2.00); the results were consistent with the results of the 16S rRNA gene sequence analysis (homologies>97.0%). These data indicate that MALDI-TOF MS can be used as a clearly rapid, accurate, and cost-effective method for the identification of M. pulmonis isolates, and this system may represent a serious alternative for clinical laboratories to identify Mycoplasma species.
A one-month male Greyhound dog presented with a swinging gait of the hindlimbs, and later developed muscular atrophy of the femoral region and hyperextension of hindlimbs. The dog had positive serum IFAT titers to Neospora caninum, but a negative titer in the cerebrospinal fluid (CSF). N. caninum-specific DNA was amplified from the CSF using a semi-nested polymerase chain reaction assay. Clusters of protozoa in biopsied muscle fibers were subsequently confirmed as N. caninum tachyzoites by immunohistochemical examination. Early recognition and treatment are necessary for effective recovery of clinical canine neosporosis, but antemortem diagnosis is difficult. We suggest that the detection of parasite deoxyribonucleic acid in the CSF is a useful antemortem diagnostic method in facilitating treatment of this disease.
Extraskeletal myxoid chondrosarcoma was found in a five-month-old male Irish setter dog. At necropsy, the largest mass, measuring 15 × 13 × 13 cm, was found in the right caudal lobe of the lung, and metastatic small masses were observed in multiple organs. Microscopically, the tumor comprised mainly atypical mesenchymal cells and myxoid stroma, which stained positively with Alcian blue. Immunohistochemically, the tumor cells stained positively for vimentin, S-100 protein, neuron-specific enolase, calretinin, and chromogranin A. Ultrastructurally, the cytoplasm of the tumor cells was comprised abundant rough endoplasmic reticulum, mitochondria, Golgi complex, free ribosomes and short irregular microvillous processes extending from the cytoplasm. Based on these pathological findings, this tumor was diagnosed as extraskeletal myxoid chondrosarcoma.
Vascular tumors and disorders, like angiomatosis, are rarely described in cetacean species. A retrospective histological study was carried out on lung samples from 35 common dolphins (Delphinus delphis) stranded in the Canary Islands coasts looking for morphological vascular changes and likely related causes. Twenty-five out of thirty-five (71%) common dolphins showed focal or multifocal angiomatosis-like lesions. A high association between this type of vascular proliferation and parasitic infestation was observed. In addition, a single pulmonary cavernous hemangioma not previously reported in common dolphins is presented.
Enteritis has been recognized as a major symptom in domestic animals and human patients suffering from feed and food poisonings. The aim of the present study was to clarify the excitatory mechanism of the pelvic nerve afferent which may influence the occurrence of enteritis in response to nociceptive chemical stimuli of the colon in normal and abnormal rats with colitis induced by dextran sulfate sodium (DSS). The pelvic nerve afferent activity was markedly increased by colonic instillation of solution (0.5 ml) of acetic acid (5–25%) and capsaicin (100μg/ml). The nerve activity was augmented by colonic instillation of capsaicin to a greater extent in rats with DSS-induced colitis than in normal control rats. This augmented activity by capsaicin was more prominent at one day (DSS-1) than at 8 day (DSS-8) after the administration of DSS. The increased nerve activity caused by capsaicin in DSS-1 and DSS-8 was significantly inhibited by pretreatment with ruthenium red, which is a nonselective inhibitor of TRP channels of unmyelinated C-fibers (nociceptors). In conclusion, it was elucidated that the nociceptive function of the pelvic nerve was largely elevated at one day after DSS-induced colitis and such increased function was mostly mediated by TRP channels.
Although some clinical studies have suggested that spironolactone (SPL), a mineralocorticoid receptor (MR) antagonist, appears to increase the blood glucose levels, experimental studies have not supported this notion. Here, we investigated the effect of SPL on blood glucose levels in SHR/NDmcr-cp(cp/cp) (ND) rats, an animal model of metabolic syndrome, in comparison with that of eplerenone (EPL), another MR antagonist. At the same dose of 100 mg/kg, SPL and EPL increased the urinary sodium-to-potassium ratio to a comparable extent, indicating that both agents have similar renal MR antagonistic efficacy in ND rats. Interestingly, SPL but not EPL significantly increased the level of blood glucose. The oral glucose tolerance test revealed that treatment with SPL led to glucose intolerance. The levels of serum insulin and adiponectin, regulators of the blood glucose level, were virtually unaffected by treatment with SPL. On the other hand, SPL induced a marked increase in the blood level of aldosterone, known to be a risk factor for insulin resistance. These results demonstrate that in comparison with EPL, SPL characteristically impairs glucose tolerance in an animal model of metabolic syndrome, in association with a higher blood level of aldosterone.
Platelet-rich plasma (PRP) was administered to cattle with hoof defects (10-mm drill hole) to promote sole defect healing. Two types of gels were prepared. One was a mixed gel [compound of gelatin microspheres (GM) incorporated with PRP and alginate] and was used for the test group, while the other was an alginate gel used for the control group. Each hole was filled with one of these gels. The drill hole depth, pressure pain, and hardness of the regenerated tissue were measured for 3 weeks after treatment. These measurements improved significantly in the test group than in the control group. The results suggest that a compound of GM incorporated with PRP and alginate had a hoof-regenerating effect in cattle.
Progressive ataxia and paralysis in three Miniature Dachshunds were found to be caused by idiopathic sterile pyogranulomatous inflammation of epidural fat between T5 and L4. All dogs were managed by hemilaminectomy and removal of epidural compressive material. Surgical findings and histopathological evaluation were necessary to diagnose epidural pyogranulomatous inflammation. A dog did not regain motor and sensor function after the surgery. Two dogs had exhibited improved neurological function after the surgery, but they recurred. Oral cyclosporine treatment was useful for their long remission. Idiopathic sterile pyogranulomatous inflammation of epidural fat can be considered to be a cause of thoracolumbar myelopathy in dogs.
The purpose of this study was to demonstrate that a barren parous Thoroughbred mare with lactation induced by hormonal treatment can be introduced to an orphan foal at the same farm and that the mare can become pregnant after the end of the hormonal treatment. An additional purpose was to investigate the changes in the plasma concentrations of prolactin, estradiol-17β, progesterone, follicle-stimulating hormone, and luteinizing hormone before, during, and after hormonal treatment. The difference in body weight between the adopted foal and the control foals, which were at the same farm and raised by their natural mothers, was 17 kg at 24 weeks old, when the foals were weaned. However, the adopted foal and the control foals had almost the same weight at 35 weeks old and later. The first ovulation after hormonal treatment was confirmed 10 days after the end of hormonal treatment and then the normal estrous cycle resumed. Furthermore, the changes in plasma progesterone, estradiol-17β, follicle-stimulating hormone, and luteinizing hormone showed regular patterns after the first ovulation. Conception was confirmed in the fifth ovulation. Meanwhile, another study demonstrated that conception was confirmed in the first ovulation after hormonal treatment. The present study is the first to demonstrate the hormonal profiles during and after induction of lactation in a Thoroughbred mare. This approach is useful for solving the economic and epidemic problems of introducing a nurse mare to an orphan foal.
By a series of experiments, we identified a new member of the locoweed family, Oxytropis serioopetala, that produces swainsonine, a phytotoxin harmful to livestock. In order to evaluate the toxicity of Oxytropis serioopetala, its extract was administered to ten rabbits by gavage at a dose of 1.5 mg/kg body weight as swainsonine once daily. After the 20th day, the rabbits appeared depressive and anorexic. In addition, intention tremors were apparent upon movement. Their eyes were dull. The rear limbs were severely weak and even progressed to partial paresis. The activities of serum aspartate aminotransferase (AST), alanine transaminase (ALT) and alkaline phosphatase (AKP) and urea nitrogen (BUN) levels in the poisoned rabbits increased significantly. Serum α-mannosidase (AMA) activity decreased markedly. Pathomorphological lesions in the locoweed-poisoned rabbits developed severe microvacuolation of visceral and neurological tissue. Extensive vacuolation was observed in the liver, kidney and brain. These clinical and pathological features are similar to the symptoms of locoism.