We have studied the vasculature of the retina, ciliary processes and choroid in the North American raccoon (Procyon lotor), a nocturnal mammal, using light and scanning electron microscopic examination of corrosion casts. We carried out an identical study in the crab-eating macaque (Macaca fascicularis), which forages only during the daytime, in order to compare the ocular vasculature with that of nocturnal mammals. Our observations in raccoons demonstrated a photoreceptor layer associated with rich lymph and a poorly vascularized retina. The meridian region of the eye, which lies in the horizontal plane and pass around the optic disc, had a markedly sparse capillary network. This horizontal sparse vascular band may correspond to a visual streak. Ciliary process capillaries were delicate, and formed a well-developed and compact network. Choriocapillaries were quite thin and formed a coarse capillary network. This contrasted with the dense retinal and well-extended choroidal capillary networks noted in the macaques. Our findings suggest that the sparse retinal capillary network in raccoons is extremely beneficial for photon capture, thereby allowing the raccoon to see well at night, as the retinal vessels restrict the inflow of photons toward the photoreceptors. The well-developed lymph probably compensates for the sparse retinal capillaries and choriocapillaries and nourishes the retina in the nocturnal raccoon.
In native Mongolian horses, the incidence and distribution of Rhodococcus equi are poorly understood. One hundred and fourteen equine fecal samples and 71 soil samples were collected from the camp sites of 26 nomadic families located in three areas less than 100 km from Ulaanbaatar, Mongolia. Five fecal samples were also collected from foals of Przewalski's Horses introduced into the Hustai National Park, Mongolia. No R. equi was isolated from the Mongolian horses or the soil samples. However, three colonies of R. equi were isolated from two fecal samples collected from foals of Przewalski's Horses. These isolates were avirulent, with neither 15- to 17-kDa antigens (VapA) nor a 20-kDa antigen (VapB) genes being detected. We concluded that native Mongolian horses and their environment appear free from contamination with R. equi.
Alterations in the activities of enzymes related to energy metabolism in canine lymphoma cells were investigated. Cytosolic pyruvate kinase (PK) and mitochondrial malate dehydrogenase (MDH) activities in lymphoma cells were significantly higher than those in lymphocytes obtained from lymph nodes of healthy dogs, whereas cytosolic lactate dehydrogenase (LDH) activity was significantly lower in lymphoma cells. The cytosolic M/L ratio (MDH activity/LDH activity), which is considered to be a good indicator of energy metabolism related to glucose utilization in animal tissues, was significantly higher in lymphoma cells than in the normal lymphocytes.
We measured the concentrations of S-100B, a marker protein used in humans to detect brain damage, in the cerebrospinal fluid (CSF) of clinically normal cattle (n=15, mean age ± SD: 31.8 ± 37.5 months) and of cattle with various inflammatory disorders (n=43, 70.6 ± 31.9 months). The mean ± SD CSF S-100B level was 2.9 ± 1.6 ng/ml in the normal group and 7.0 ± 7.4 ng/ml in the diseased group. Thirteen diseased cattle that had developed no obvious neurological signs showed abnormally high S-100B concentrations (> 8.0 ng/ml), whereas the two cattle with neurological disorders did not. No particular disease could be related to the S-100B rise. Therefore, it remains inconclusive whether measurement of CSF S-100B concentration is useful in veterinary neurological diagnosis.
The experiment was aimed to test the efficacy of sugar cane extract (SCE) on the modulation of pig immunity under field conditions. The SCE preparation consisted of sugar cane extract (20%) and oilcake of rice bran (80%). SCE (500 mg/kg of body weight per day) was fed to weanling pigs on 3 consecutive days per week for 4 weeks. The results showed a significant enhancement of cytotoxicity of natural killer (NK) cells and phagocytosis by neutrophils and monocytes, compared to untreated pigs. The enhancement of NK cell function may have protected against porcine reproductive respiratory syndrome (PRRS), as there was a reduction in seroconversion rates in treated pigs. Moreover, SCE-treated pigs showed a 7.87% growth enhancement compared with untreated controls. Thus SCE produces an immunostimulative effect on porcine innate immunity that may provide protection against pathogens.
Tacrolimus was reported to have no antifungal activity against dermatophytes, but it might show a synergistic fungicidal activity with azoles against dermatophytes as in the case of pathogenic yeasts. Therefore, we examined the antifungal activity of tacrolimus combined with itraconazole (ITZ) against five strains of Trichophyton mentagrophytes by measuring cell growth and performing MIC (minimum inhibitory concentration) testing. The mean colony diameter of T. mentagrophytes on 1/10 diluted Sabouraud dextrose agar (dSDA) with tacrolimus combined with ITZ was significantly shorter than that on dSDA with tacrolimus or ITZ. MICs of tacrolimus, ITZ, and tacrolimus combined with ITZ against T. mentagrophytes were determined, respectively. The results revealed a synergistic activity of tacrolimus in combination with ITZ against T. mentagrophytes.
A 10-year-old cat with the paresis of hind limbs was initially diagnosed as a hypertrophic cardiomyopathy followed by acute thromboembolism of caudal abdominal aorta from the findings of the medical examinations. However, this case was proved to be an chronic myocardial infarction due to arteriosclerosis of coronary arteries by the pathologic diagnosis. In the left ventricular, the hypertrophy and the narrowing were slight, and a coagulative infarction was seen obviously. The intramural coronary arteriosclerosis showed thickening of the wall due to medial hyperplasia by fibrosis, and arterial stenosis. Myocardial infarction and arteriosclerosis are scarcely any reports of these lesions in cats. This case is valuable for an extremely rare case of myocardial infarction in the cat.
In order to determine insulin secretability and glucose utilization, a glucose tolerance test was performed in ateliotic cattle of 2 paternal strains; MHO and HSK cattle. MHO and HSK cattle showed different endocrine patterns in our previous study. Area under the insulin concentration curves (insulin-AUC) in the ateliotic cattle were significantly lower (122.3 ± 59.4 ng·min/ml and 99.2 ± 24.8 ng·min/ml for MHO and HSK cattle, respectively) than the control cattle (420.2 ± 175.2 ng·min/ml). These low insulin responses to GTT may have an influence on growth retardation in MHO and HSK cattle.
To investigate the toxic effect of neutrons at energies of approximately 1MeV on the ear, we exposed 7-day-old mice to 1.0 Gy of monoenergetic neutrons (1.026 MeV) or 137Cs gamma rays, and assessed subsequent morphological changes in the inner ear by light and scanning electron microscopy. Monoenergetic neutrons, but not gamma rays, caused acute changes in the ear. The epithelium of the greater epithelial ridge in the organ of Corti had disappeared by 72 hr post-irradiation, as a result of epithelial apoptosis observed 6 hr post-irradiation. Radiation could induce apoptotic cell death of the epithelium of the greater epithelial ridge at 3 or 4 days of age. Protruding structures were detected on the surface of the hair cells by 72 hr post-irradiation. The neutron-irradiation also caused the apoptotic cell death of epithelial cells at the nasal conchae, and subsequent acute otitis media continued until 10 weeks of age.
Gastrointestinal helminths were collected from 49 Japanese tree sparrows (Passer montanus saturatus) in Tokyo, Japan. In 16 sparrows, 1-9 (average, 3.5) gizzard spirurid nematodes (Acuaria skrjabini Ozerskaya, 1926) were found embedded in the mucosa of the gizzard. In addition, Capillaria sp., Platynosomum passeri Yamashita et Tsumura, 1962, and a hymenolepidid cestode were collected from 1, 2, and 1 sparrows, respectively. A sexually mature A. skrjabini female and 3 males were found also in a young gray starling (Sturnus cineraceus) that was found dead in the same area after failure to leave the nest. Starlings are a new host record for this spirurid species. Until this study, this gizzard spirurid species has not been recorded in this country or the Far East region.
Unusual metastasis of malignant aortic body tumor to multiple bones was detected in a 5-year-old female English Setter dog. Radiographs exhibited an abnormal mass in the base of heart and osteolytic lesions in the bodies of T11 and L2 vertebrates, body of right femur, right proximal humoral epiphysis and infraspinous fossa near to the neck of right scapula. At necropsy, multiple tumor masses of various sizes were observed also in the bones as well as the heart base and tracheobronchial lymph node. Tumor masses of L2 and T11 protruded into the vertebral canal and compressed corresponding sites of spinal cord, leading to paraplegia. Histopathologically, the tumor cells, arranged in sheets or nests, were polyhedral, lightly eosinophilic, finely granular cytoplasm with mostly round to oval nucleus and had scattered bizarre giant cells. Ultrastructural study revealed the characteristic findings that tumor cells contained a large number of small, electron-dense, membrane-limited secretory granules in cytoplasm. This is thought to be an extremely rare case having multiple bone metastases of a malignant aortic body tumor.
Quantitative trait locus (QTL) analyses of plasma cholesterol levels were carried out in three sets of F2 mice that were formed in a `round-robin' manner from C57BL/6J, KK (-Ay), and RR strains. Six QTLs were identified on chromosomes 1 (Cq1, Cq2, and Cq6), 3 (Cq3), and 9 (Cq4 and Cq5); of these, Cq2 colocalized with Cq6, and Cq4 colocalized with Cq5. The major candidate gene for Cq2 and Cq6 is Apoa2, and that for Cq4 and Cq5 is Apoa4. The adequacy of polymorphisms in candidate genes as cause of QTLs was investigated in this study. For Apoa2, three different alleles (Apoa2a, Apoa2b, and Apoa2c) are known. Since there was no significant physiologic difference between Apoa2a and Apoa2c alleles, previous hypothesis that Apoa2b was different from Apoa2a and Apoa2c in the ability to increase cholesterol levels was further supported. Presumably, G-to-A substitution at nucleotide 84 and/or C-to-T substitution at nucleotide 182 are crucial to make the Apoa2b unique. On the other hand, for Apoa4, the most striking polymorphism was the number of Glu-Gln-Ala/Val-Gln repeats in carboxyl end; however, this might not be responsible for QTLs. Instead, a silent mutation, C-to-T substitution at nucleotide 771, was shown to be completely correlated with the occurrence of QTLs in a total of six F2 intercrosses. Provisionally, but reasonably, these base substitutions are qualified as primary causes that constitute QTL effect. The potential strategy for identifying genes and base substitutions underlying QTLs is discussed.
To investigate an adequate infusion rate of propofol for total intravenous anesthesia (TIVA) in horses, the minimum infusion rate (MIR) comparable to the minimum alveolar anesthetic concentration (MAC) of inhalation anesthetic was determined under constant ventilation condition by intermittent positive pressure ventilation (IPPV). In addition, arterial propofol concentration was measured to determine the concentration corresponding to the MIR (concentration preventing reaction to stimulus in 50% of population, Cp50). Further, 95% effective dose (ED95) was estimated as infusion rate for acquiring adequate anesthetic depth. Anesthetic depth was judged by the gross purposeful movement response to painful stimulus. MIR and Cp50 were 0.10 ± 0.02 mg/kg/min and 5.3 ± 1.4 μg/ml, respectively. ED95 was estimated as 0.14 mg/kg/min (1.4MIR).
A 12-year-old intact male mongrel dog with a weight of 22 kg was referred with a complaint of progressive tetraparesis. Cervical myelography revealed an intradural-extramedullary mass at the second cervical vertebra. After computed tomography (CT) under general anesthesia, the patient showed dyspnea and cyanosis caused by insufficient movement of the chest wall. Positive pressure ventilation was therefore initiated. Hemilaminectomy and partial mass removal were performed 12 hr after the CT. The mass was histopathologically diagnosed as meningioma. Gradual weaning from the mechanical ventilation lasted for 80 hr after the operation. The patient eventually recovered from the ventilatory failure and the tetraparesis at approximately 6 and 14 days after the operation, respectively.
A 14-year-old spayed female cat weighing 2.3 kg developed tension pneumoperitoneum that progressed for 6 hr. Abdominocentesis was performed and 1.3 L of gas was aspirated after which the cat's respiratory condition improved. The next day, the cat's abdomen redistended, and laparotomy was performed. A gastric perforation was noted and sutured after the margin was resection. The cat showed a good physical condition without any gastrointestinal signs at 6 months after surgery.
A wild raccoon dog (Nyctereutes procynoides) which died due to a traffic accident on 18 October 2001, and was determined to be 4.5 years old, was examined. Visual appearance of the external genitalia in this animal showed to be female with a large penis-like clitoris protruding from the vulvar juncture. Visual examination of the internal genitalia revealed that the animal possessed both testes and uterus. Histological appearance of the removed gonads showed only Sertoli cells but no spermatogenesis. Using polymerase chain reaction with skin biopsy directed against the sex-determining region on the Y chromosome (SRY) gene, the genomic SRY gene was expressed as a single band and sequenced. Based on these findings, this raccoon dog was diagnosed as male pseudohermaphrodite.
Infection with equine herpesvirus-4 (EHV-4) is a major cause of respiratory tract disease, equine rhinopneumonitis, in horses. Although the full sequence of EHV-4 has been reported, genomic differences among EHV-4 field isolates have not yet been characterized. In this study, the genomic diversity between 23 Japanese EHV-4 isolates was analyzed by digestion with restriction endonucleases (BamHI, BgIII, EcoRI, SacI, and SalI) and polymerase chain reaction (PCR). The restriction endonuclease digestion patterns of the EHV-4 field isolates showed distinct differences which included mobility shifts of some fragments as well as loss and/or gain of fragments. Two EHV-4 genes containing repeat sequences, ORFs 24 and 71, were amplified by PCR and the amplified fragments were compared among the field isolates. The sizes of the amplified fragments varied among epizootiologically unrelated isolates, while the fragments of related isolates had the same size. The observed genomic diversity among EHV-4 field isolates may be a useful tool for epidemiological study of equine rhinopneumonitis by EHV-4 infection.
To estimate the genetic background of Japanese wild boars inhibiting the 4 prefectures of Shikoku Island (Kagawa, Tokushima, Kouchi and Ehime), we examined haplotypes of mitochondrial DNA (mtDNA) and genotypes of the nuclear glucosephosphate isomerase-processed pseudogene (GPIP) in 189 wild boars. Of the 8 different mtDNA haplotypes (J5, J10, J12, J13, J15, J19, J20 and E33) detected in Shikoku Island, the first to be identified were J19 and J20 (of Japanese wild boar lineage) and E33 (of European domestic pig lineage). The presence of haplotype E33 indicates local crossbreeding between wild boar and escaped domestic pigs and/or crossbred Inobuta. Four kinds of the GPIP genotypes were detected from 189 wild baors in Shikoku Island, but no European GPIP alleles were found. In 113 wild boars, no antibodies against Classical Swine Fever or Aujeszky's disease were detected, suggesting that they had not been exposed to those pathogens.