A cDNA, which has a high homology with teleost Platichthys flesus [Arg8] vasotocin (AVT) receptor (GenBank: AK033957), was found in mouse genome database. Analyses of the deduced amino acid sequence revealed that a cDNA has several features of AVT receptor. We tentatively named it as a mouse vasotocin receptor (MVTR). A two-electrodes voltage clamp technique was applied to characterize the MVTR expressed in Xenopus laevis oocytes. AVT induced Ca2+-dependent Cl- currents in Xenopus oocytes injected with MVTR cRNA. On the other hand, [Arg8] vasopressin, oxytocin and isotocin did not induce such currents. RT-PCR showed that MVTR mRNA was specifically expressed in the brain. In situ hybridization analysis demonstrated significant expression of MVTR mRNA in suprachiasmatic nucleus, arcuate nucleus and medial habenular nucleus of mouse brain. These results suggest that MVTR may mediate a variety of physiological functions in mouse.
Card15/Nod2 has been suggested to be an intracellular pathogen-associated molecular pattern (PAMPs) recognition molecule, which contains a leucine-rich repeat region similar to the Toll-like receptors (TLRs). Card15/Nod2 gene variants play an important role in the susceptibility to Crohn's disease. In this study, we examined the kinetics of Card15/Nod2 expression in intestinal tissue during inflammation in the 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-treated rat experimental colitis model. At 2 and 4 days after TNBS administration, the mononuclear cells remarkably infiltrated the mucosal layer and tunica muscularis, which was followed by a gradual decrease to resting levels at 14 days after TNBS administration. Card15/Nod2 mRNA expression increased and peaked at 4 days after the TNBS administration, followed by a gradual decrease in accordance with the amelioration of the inflammatory response. Expressions of Tlr2, Tlr4 and Myd88 were also upregulated in the inflamed colonic region, and in an in situ hybridization study, a positive signal for Card15/Nod2 was observed in the crypt of the epithelial cell layer and in the infiltrated cells of the submucosal and myenteric regions. These results suggest that in addition to the TLR recognition systems, Card15/Nod2 may contribute to the inflammatory process not only in the epithelial and submucosal layers but also in the tunica muscularis.
The expression pattern of CD44 was studied in the rat testis following ischemia/reperfusion (I/R) injury to elucidate the possible role of the CD44 adhesion molecule in acute experimental testicular torsion. Western blot analysis showed that CD44 expression began to increase significantly 24 hr after reperfusion, compared with the normal control; the increased expression persisted until 96 hr after I/R. Immunohistochemistry showed that, in the normal testis, CD44 was constitutively expressed mainly in ED2-positive resident macrophages in the interstitial space. After I/R, the majority of inflammatory cells in the interstitial space surrounding the damaged tubules were ED1-positive macrophages that were CD44-positive. These findings suggest that the significant increase in CD44 expression that occurs during the delayed phase after reperfusion originates from infiltrating macrophages possibly in anticipation of the migration and adhesion of additional macrophages into the affected testis.
Little is known about the distribution of Rhodococcus equi in the soil environment of native horses in China. One hundred and eight soil samples were collected from native-horse farms in the Hulun Beier grasslands of eastern Mongolia, the Xilin Goler grasslands of southern Mongolia, and Tongliao City in Inner Mongolia, China. The isolation rates of R. equi from soil samples from the Hulun Beier and Xilin Goler grasslands ranged from 25.9% to 30.0%. In contrast, isolation rates from soil samples from Tongliao City were as high as 82.3% and the mean number of R. equi in soil samples from Tongliao City was 10 times more than those of samples from the grasslands. The 488 isolates were examined using PCR for the presence of genes that encode virulence-associated 15-17 kDa antigen protein (VapA) and the 20 kDa antigen protein (VapB). All isolates were negative for virulence-associated proteins. Plasmid profiles of these avirulent isolates showed that cryptic plasmids of various sizes were present with an incidence of 13.3% to 21.5%. The results of the present study contrast with those of our recent study (J. Vet. Med. Sci. 67:611-613, 2005), in which we reported that R. equi was absent from Mongolian horses in Ulaanbaatar, Mongolia. It is suggested that the difference between the results of these two studies is due to the mobile pasturing system in Mongolia and nonmobile pasturing system in Inner Mongolia.
To investigate the roles of mammary PTHrP in calcium uptake and/or release in the mammary gland of cows, plasma PTHrP and Ca levels, and their arterial-venous differences were examined in a Jersey cow during the periparturient period. Levels of Ca in both abdominal aorta and abdominal subcutaneous vein blood slightly decreased around the parturition and at 24 days after the parturition, however, no remarkable arterial-venous differences were observed. Plasma PTHrP levels in both arterial and venous samples were below the detection limit (0.57 pmol/l) during the experimental period. Milk PTHrP and Ca levels were measured in 9 Holstein dairy cows. Although plasma PTHrP levels in all arterial and venous samples were also below the detection limit, milk PTHrP and Ca levels were remarkably high, ranging from 14,900 pmol/l to 41,200 pmol/l and from 772 mg/l to 1,200 mg/l, respectively. In addition, a significant positive correlation (P<0.01) was observed between milk PTHrP and Ca levels. These results suggested that mammary PTHrP is closely related to Ca concentration in the milk.
Elastase activity and concanavalin A (Con A) low affinity bovine lactoferrin (bLf) molecule were detected in mammary gland secretions (MGSs) from mammary glands (MGs) with clinical staphylococcal mastitis. Changes in clinical symptoms correlated with increases in both elastase activity and the concentration of Con A low-affinity Lf in MGSs from mastitic MGs. Bovine Lf treated with elastase (elastase-Lf) showed various small bLf molecules and the same image on Con A two-dimensional immunoelectrophoresis as low Con A affinity bLf in MGSs. We confirmed the presence of four common bLf peptides for the elastase-bLf and low Con A affinity bLf molecules in mastitic MGSs, and synthesized four peptides. Strong mRNA expression of interleukin-6 (IL-6), tumor necrosis factor α (TNFα), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) was induced in bovine mammary epithelial cells on stimulation with low Con A affinity bLf, elastase-bLf, and GQRDLLFKDSAL, a synthesis bLf peptide based on nuclear factor kappa B (NFκB) activation. These results suggest that bLf was cleaved by elastase, and that this cleavage changed the physical function of Lf. Our results indicate that elastase induced production of low Con A affinity bLf, including the bLf peptide GQRDLLFKDSAL, and had an inflammatory effect on staphylococcal mastitis.
This study investigated whether a small volume of 7.2% hypertonic saline solution (HSS) could affect M-mode echocardiographic indices in dogs. HSS induced significant increase in heart rate, stroke volume and cardiac index, when the fluid infusion was completed (P<0.05). In the HSS group, the left ventricular end-diastolic volume index, as an index of preload, significantly increased (P<0.05), whereas left ventricular end-systolic volume index were not altered. HSS induced slight increases in ejection fraction at end of infusion despite significantly differences were not observed. In conclusion, HSS did not induce a demonstrable effect on M-mode echocardiographic indices of systolic functionenhance cardiac contractility, but it caused preload augmentation that may contribute to an abrupt and transient increase in cardiac output just after HSS infusion.
A 10-year-old male beagle was referred to us with seizure related to hypoglycemia and a large intraabdominal mass. Based on various types of imaging and a laparoscopic biopsy, the intraabdominal mass was diagnosed as a hepatocellular carcinoma (HCC) of the quadrate lobe. The hypoglycemia was suspected to be associated with the HCC. After lobectomy of the quadrate lobe was performed, blood glucose levels continued to increase to higher than normal values and sugar was detected in the urine. The dog was diagnosed as diabetes mellitus (DM) and was treated with insulin for over two years after the surgery.
To investigate the relationships between trace elements concentrations in hair and atrial fibrillation (AF) in horses, concentrations of nineteen trace elements were detected in hair using the particle induced X-ray emission (PIXE) method. The horses were assigned to either control (n=22, no abnormalities) or AF groups (n=5) based on electrocardiograph findings. The mean concentrations of Ca and Zn in the hair of the AF group were significantly higher than those in the control group. The Zn/Cu ratio of the hair in the AF group (29.8 ± 5.5) was significantly higher than that in the control group (23.4 ± 2.2, P<0.05). The results of the present study suggest that there is a relationship between elevated concentrations of Ca and Zn in hair and AF.
To investigate the late effects of neutrons at the energy below 1 MeV on the liver carcinogenesis as a function of age, one-week old mice were exposed to 1.0 Gy monoenergetic neutrons (0.317, 0.525 and 1.026 MeV) or 137Cs gamma rays. Survival and carcinogenesis were examined by 18 months of age. Following radiation, tumor incidences in liver, Harderian gland, lung, ovary and pituitary gland were compared. The proportion of the lifespan with liver tumors exposed to neutrons to that exposed to gamma rays was calculated as a function of age. Survival rates among the three groups exposed to neutrons of different energies were not significantly different from one another but shorter than those treated with gamma rays for both sexes. With regard to liver tumor incidence evaluated at 18 months of age, the effectiveness of neutrons to gamma rays was 2.54 for females, and 2.08 for males by the factor. Levels of estrogen in the serum were similar between mice bearing liver tumors and those devoid of tumors. In conclusion, all three energies of neutrons induced similar effectiveness with respect to liver carcinogenicity. Proportions of the lifespan with liver tumors of neutron-exposed to gamma-exposed were shorter in females than males along with ages over 12 months. To obtain this factor at every age contributed for the evaluation of the biological effectiveness of radiations with the parameter of tumor incidence and latency simultaneously.
Helminth parasites were collected from 9 raccoon dogs (Nyctereutes procyonoides viverrinus) and 2 Japanese weasels (Mustela itatsi sho) on Yakushima Island, Japan. The former carnivore was introduced to this World Natural Heritage Area presumably within the last two decades, expanding its population thence, although detailed process(es) of the introduction is unknown. The collected trematodes from raccoon dogs included the triploid form of Paragonimus westermani, Brachylaima tokudai, Maritrema eroliae, and Pseudocryptotropa sp. Simultaneously, Paragonimus ohirai was found in one weasel killed by a traffic accident. Although the triploid form of P. westermani and P. ohirai are known to be distributed in some river-mouth areas of Yakushima Island based on previous surveys on crab hosts, natural infection was detected for the first time in wild final hosts. Particularly, the raccoon dog infected with P. westermani was caught in a mountainous area, distant from human residence or river-mouth areas. Although it is possible that the infected raccoon dog moved from a river-mouth area endemic with P. westermani after infection, the alternative scenario remains to be pursued; the endemic area of this zoonosis is expanding along with the recent expansion of raccoon dogs or feral cats (Felis catus), that became prevalent recently on this island including the mountainous areas. Maritrema eroliae taking a variety of shorebirds as its natural final hosts, and a minute trematode, Pseudocryptotropa sp., taking unknown natural final host(s) were recorded for the first time in raccoon dogs.
Helminth parasites were collected from 14 raccoon dogs (Nyctereutes procyonoides viverrinus) and 2 Japanese weasels (Mustela itatsi sho) on Yakushima Island, Kagoshima Prefecture (Kyushu), Japan. In addition to trematodes and nematodes reported separately, everted cystacanths of 3 bird acanthocephalans (Mediorhynchus robustus in 5 animals, Porrorchis leibyi in 2 animals, and Sphaerirostris lanceoides in 1 animal) were collected from the raccoon dogs introduced recently on this World Natural Heritage Area. A cystacanth of P. leibyi was collected also from a weasel indigenous to this island that were killed by traffic accidents. Recovery of everted cystacanths of M. robustus from the intestine of raccoon dogs was remarkably frequent (36%), suggesting that this acanthocephalan should be highly prevalent in passerine hosts on Yakushima Island, and the animals might vigorously take insect hosts or paratenic hosts. Furthermore, the present report is the second on M. robustus after its first record in Japan (Aichi Prefecture, Honshu) as M. garruli from a Eurasian jay (Garrulus glandarius japonicus) by Yamaguti in 1939. Porrorchis leibyi has never been recorded in Japan.
Nematodes were collected from 14 raccoon dogs (Nyctereutes procyonoides viverrinus) on Yakushima Island, Kagoshima Prefecture (Kyushu), Japan, that were the progeny of recently introduced animals to this World Natural Heritage Area, probably within the last 2 decades. Seven nematode species (Toxocara tanuki, Ancylostoma kusimaense, Arthrostoma miyazakiense, Strongyloides planiceps, Trichuris vulpis, Gongylonema sp., and Dirofilaria immitis) were collected from the raccoon dogs. Two nematode species (Molineus legerae and Strongyloides martis) were collected from 2 Japanese weasels (Mustela itatsi) indigenous to this island that were killed by traffic accidents. Considering that foxes and other carnivores, except for weasels, dogs and cats, are not distributed on this island, most of soil-borne nematodes such as roundworms, hookworms, and threadworms in raccoon dogs should have been introduced by the original population from the mainland Japan, and the infection hence maintained at a high level by new generations. Recovery of the third-stage larvae of Gongylonema sp. from the esophagus of raccoon dogs was remarkably frequent (79%), suggesting that the animals might vigorously take insect hosts. Although S. martis have never been recorded from weasels in Japan until this study, this threadworm might be prevalent in a variety of mustelids in Eurasia.
The prevalence of Babesia (Theileria) equi and B. caballi infections in donkeys in western Xinjiang China was investigated. In total, 93 serum samples were randomly taken from donkeys in the Kashi and Ili areas, and examined for B. equi and B. caballi infections by enzyme-linked immunosorbent assays using recombinant antigens. Of the 93 samples, 9 (9.6%) and 36 (38.7%) samples were positive for B. equi infection and B. caballi infection, respectively. In addition, 2 (2.2%) samples were positive for both B. equi and B. caballi infections. These results indicate that equine babesiosis might be extensively prevalent in donkeys in western Xinjiang.
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 9-year-old, castrated male Japanese domestic cat presented with a complaint of exertional dyspnea. Based on the radiographic findings, presumptive diagnosis of aspiration pneumonia or primary diffuse pulmonary neoplasia in the right middle lobe was made. Histologically, the pulmonary lesion was characterized by diffuse thickening of alveolar wall with the proliferation of apparently atypical irregular-shaped cells. Immunohistochemical staining using anti-human factor VIII-related antigen antiserum showed positive reaction in the cytoplasm of the atypical cells. According to the findings, the lesion was diagnosed as pulmonary intravascular hemangiosarcoma.
Six Eurasian red squirrels (Sciurus vulgaris orientis), victims of road traffic found during 2002 and 2004 near the Noppro Forest Park in Ebetsu, Hokkaido, Japan, were examined for the presence of Babesia parasites. Three of the six squirrels exhibited positive signals by nested PCRs targeting both the 18S rRNA and β-tubulin genes. Three squirrels proved to be infected with a B. microti-like parasite as evidenced by sequencing the amplified DNAs and by the morphology of the intraerythrocytic parasites. Genotypically, however, the parasite appeared to be of a new type, as it was clearly distinguishable from any of the known types that have previously been reported in various wild animals. This is the first report showing molecular evidence for the presence of B. microti-like parasites in Sciuridae.
A laser bowel welding technique for dogs and cats was developed. The bowel was pinched using a special clamp having an opening on the body developed for this experiment (LW clamp). Using the 2 different types of contact probe (blunt tip: Laser Bipolar Dissector (LBD); sharp tip: Super Scalpel Dissector (SSD)), the laser passed through the hole in the LW clamp to cut the bowels, while at the same time, sealing the cut portion. The results obtained in this study showed that the optimum laser output using LBD was 6-10 W in dog and cat ileum, and 8-10 W in dog and cat colon. Optimum laser output using SSD was 6-8 W in dog ileum, 8-10 W in dog colon, 10 W in cat ileum and 6-8 W in cat colon. No marked differences were observed between ileum and colon when using either LBD or SSD. At the same power, burst pressure tended to be slightly higher with LBD than with SSD, although there were not significant differences between them. Histologically, complete sealing of the welded site was seen. Welding and cutting of bowel in dogs and cats was thus confirmed to be possible using the LW clamp in combination with LBD or SSD probes under a diode laser output of approximately 8 W for 50-80 s (400-640 J/cm). Thus, we can expect that this method is applicable to clinical veterinary medicine.
The purpose of this study was to determine factors correlated with the severity of radiographic osteoarthritis (OA) scoring in dogs with cranial cruciate ligament rupture (CrCLR). Three radiographs of stifle joints (craniocaudal, mediolateral, and mediolateral radiograph with 90 degree flexion of the stifle and tarsal joints) were obtained from 36 dogs with CrCLR (Clinical group) and from 22 dogs without stifle joint disease (Control group). Information about these dogs was collected from the owners and from medical records. Radiographic OA scores in each dog in the clinical group were determined from radiographs using a numeric grading system previously reported. The tibial plateau angle (TPA) in each dog in both groups was measured on mediolateral radiographs with 90 degree flexion of the stifle and tarsal joints. The Mann-Whitney's U test was used for comparing variables between the clinical group and the control group, and Spearman's rank correlation test was used for evaluating correlations between radiographic OA scores and variables in the clinical group. No significant differences were detected between the clinical group and the control group for any of the variables. There were two positive correlations; one between the radiographic OA score and TPA (r=0.395, p=0.014); and the other between body weight and OA score (r=0.399, p=0.013) in the clinical group. Our results indicate that body weight and TPA could affect the severity of the radiographic OA score in dogs with CrCLR.
A 4-year-old female Miniature Dachshund was referred with a chief complaint of right periorbital swelling that had not responded to antibiotic therapy. Ultrasonography and fine-needle aspiration revealed that the periorbital lesion had a cystic structure without any inflammatory or neoplastic cells. Computed tomography (CT) showed that the cyst occupied a defect in the periorbital maxillary, lacrimal, and frontal bones and had invaded the nasal cavity. The lesion was histologically suspected by incisional biopsy as an epithelial cyst.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most toxic environmental pollutants that cause various biological effects on mammals. The purpose of our study was to identify the genes involved in hepatotoxicity and hepatocarcinogenesis caused by TCDD. C57BL/6 (AhR+/+, wild type) and B6.129-AhR<tm1Bra>/J (AhR-/-, knock out) mice were injected i.p. with a single treatment of TCDD at the dose of 100 μg/kg body weight. Relative liver weight was significantly increased at 72 hr after TCDD treatment without an apparent histopathological change in AhR+/+ mice (p<0.05). TCDD treatment also significantly increased activity of serum alanine aminotransferase in AhR-/- mice (p<0.05). The liver was analyzed for gene expression profiles 72 hr later. As compared with AhR-/- mice, the expression of 51 genes (>3-fold) was changed in AhR+/+ mice; 28 genes were induced, while 23 genes were repressed. Most of the genes were associated with chemotaxis, inflammation, carcinogenesis, acute-phase response, immune responses, cell metabolism, cell proliferation, signal transduction, and tumor suppression. This study suggests that the microarray analysis of genes in the liver of AhR+/+ and AhR-/- mice may help to clarify the mechanism of AhR-mediated hepatotoxicity and hepatocarcinogenesis by TCDD.
Since late 2003, highly pathogenic H5N1 influenza A viruses have spread among poultry and wild aquatic birds in Asian countries. Transmission of these viruses to humans can be lethal. Most human cases of infection with H5N1 viruses have occurred in Vietnam. Therefore, to understand the pathogenicity in mammals of these H5N1 viruses, we took viruses isolated from poultry (5 strains) and humans (2 strains) in Vietnam and tested their virulence in mice. The results showed that the H5N1 viruses from humans were pathogenic in mice and that one avian isolate was also pathogenic. These findings suggested that the H5N1 viruses circulating in poultry adapted during replication in humans or that strains pathogenic in mice were transmitted directly to humans.
Although birds infected with avian polyomavirus (APV) subclinically could be a source of infection, no epidemiological studies of APV in psittacine birds have been reported in Japan. In the present study, we investigated subclinical morbidity rate of APV in imported and domestically bred psittacine birds by polymerase chain reaction (PCR). Of 402 live birds from which blood or feather samples were taken between April, 2003 and March, 2004, 11 (2.7%) were found to be APV positive. The DNA sequences of the APV t/T antigen region were determined for five APV-positive randomly selected samples and were found to be conserved.
Equid herpes virus 1 (EHV-1) related isolates from a captive blackbuck (strain Ro-1) and Grevy's zebra (strain T965) behaved similarly to EHV-1 and EHV-9 in respect to their host cell range. Restriction enzyme analysis and a phylogenetic tree confirmed that Ro-1 and T965 were identical and more closely related to EHV-1 than to EHV-9. Differences from EHV-1 became obvious firstly, by amino acid alignments revealing two unique substitutions in the gB protein of Ro-1 and T965. Secondly, an EHV-1 type-specific monoclonal antibody did not detect its antigen on Ro-1, T965 or EHV-9 infected cells by immunohistochemistry. The results support the view that Ro-1 and T965 isolates represent a distinct, previously unrecognized species of equid herpesviruses.