Thymoma and multiple thymic cysts in a dog with acquired myasthenia gravis

An anterior mediastinal cystic lesion in an 11-year-old mongrel dog was examined. The dog showed dysbasia and vomiting due to megaoesophagus, and anterior mediastinal round mass lesion, approximately 35 mm in diameter, was found by X ray. Based on clinical examinations, the dog was diagnosed as acquired myasthenia gravis and was successfully controlled by anticholinesterase treatment for approximately 4 months. The dog died of thermic stroke and was necropsied. Grossly, fatty tissues with cysts containing yellowish fluid and white nodules were found in the anterior mediastinal area. Histopathologically, multiple cysts, neoplastic tissues, and atrophic thymus were found within the examined tissues. The cysts were lined by thin wall consisting of ciliated long cuboidal and non-ciliated round cells and were filled with eosinophilic colloidal fluid. Some extended cysts contained neoplastic foci within their lumen and walls. The neoplastic tissues consisted of mixed population of large epithelial cells with abundant clear cytoplasm and large oval nuclei, and lymphocytes. Immunohistochemically, proliferating epithelial cells were intensely positive for keratin and cytokeratin, and more than half number of infiltrating lymphocytes were intensely positive for CD3 suggesting T cells. All these findings indicate the neoplastic lesion is thymoma and multiple cysts are considered as thymic or brachial cleft cysts.     

Sequence comparison of the dopamine receptor D4 exon III repetitive region in several species of the order Carnivora

It was previously demonstrated that the dog dopamine receptor D4 (DRD4) gene is polymorphic in terms of the repeat number and/or order of 39- and 12-bp sequences located in the third exon. To examine whether or not the repetitive region is present in other species of the order Carnivora, the homologous region of DRD4 genes were sequenced in the gray wolf, raccoon dog, Asiatic black bear, common raccoon and domestic cat. In the family Canidae, the wolf had an identical sequence to that of the dog 447b allele, and a repetitive sequence similar to the dog DRD4 was also recognized in the raccoon dog. On the other hand, no obvious repeated structure was observed in the sequences of the bear, raccoon and cat.     

多花黑麦草抗病基因类似物的克隆及CAPS标记

多花黑麦草具有适应性强、生物产量高和品质好等优点,为我国南方及其他温带地区重要的牧草。本研究利用目前已克隆出的抗病基因(R基因)所编码的蛋白质结构上所具有的共同氨基酸基序NBS-LRR设计寡核苷酸简并引物,对多花黑麦草基因组进行抗病基因类似物(RGA)克隆。从克隆中筛选出具代表性的RGA克隆115个,设计RGA-STS引物113对。利用细胞质雄性不育(CMS)F1群体对RGA-STS引物进行筛选,并采用限制性内切酶酶切扩增多态序列(CAPS)法进行抗病类似物的分子标记,共检测到22对RGA-STS引物的扩增产物具多态性,22个RGA-CAPS标记均被标记于多花黑麦草遗传连锁图中。结果还表明RGA在多花黑麦草遗传连锁图中分布范围较广,并具有簇状分布特性。     

The diagnostic significance of the plasma N-terminal pro-B-type natriuretic Peptide concentration in asymptomatic cats with cardiac enlargement

We evaluated the diagnostic significance of the N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration in asymptomatic cats with cardiac enlargement. The plasma NT-proBNP concentration was measured in 21 clinically healthy control cats, and 67 asymptomatic cats with cardiac enlargement defined as end-diastolic interventricular septum thickness (IVSd) and/or diastolic left ventricular posterior wall thickness (LVPWd) >0.6 cm, vertebla heart scale (VHS) >7.8, and/or left atria/aorta ratio (LA/Ao) >1.5. The plasma NT-proBNP concentration in the asymptomatic cats with cardiac enlargement (median: 662.0, range: 24.0-2,449.0 pmol/l) was significantly higher than that in the controls (24.0, 24.0-95.0 pmol/l, P<0.001). The plasma NT-proBNP concentration was significantly correlated with the VHS, LA/Ao, IVSd and LVPWd (r=0.578, P<0.001; r=0.462, P<0.001; r=0.563, P<0.001; and r=0.764, P<0.001, respectively). Receiver operating characteristic analysis showed a cut-off value of 95.0 pmol/l for the detection of asymptomatic cats with cardiac enlargement, sensitivity and specificity of 88.1 and 100%, respectively, and an area under the curve of 0.971. These results suggest that the determination of the plasma NT-proBNP concentration can be a useful screening test for asymptomatic cats with cardiac enlargement.     

Salivary mucocele in a laboratory beagle

The histologic characteristics of a salivary mucocele in a beagle used in a toxicity study are described in this report. A pale yellowish cyst under the mandibular skin containing frothy mucus was observed at necropsy. Microscopically, numerous villous projections arose from the internal surface of the cyst and were lined by stratified epithelial-like macrophages, which were immunopositive for macrophage scavenger receptor A. A ruptured sublingual interlobar duct connected to the lumen was observed near the cyst. Luminal amorphous material showed a positive reaction with Alcian blue and periodic acid-Schiff staining as did mucin in the sublingual gland. Ultrastructurally, the epithelial-like macrophages had numerous vacuoles containing electron-lucent material, which was presumed to be lysosomal in origin, and had pseudopods on their cell surfaces interdigitating with those on the adjacent cells. This case report helps to understand the diversity of the background findings in beagles used in toxicity studies.     

Experimental H-type bovine spongiform encephalopathy characterized by plaques and glial- and stellate-type prion protein deposits

ABSTRACT: Atypical bovine spongiform encephalopathy (BSE) has recently been identified in Europe, North America, and Japan. It is classified as H-type and L-type BSE according to the molecular mass of the disease-associated prion protein (PrPSc). To investigate the topographical distribution and deposition patterns of immunolabeled PrPSc, H-type BSE isolate was inoculated intracerebrally into cattle. H-type BSE was successfully transmitted to 3 calves, with incubation periods between 500 and 600 days. Moderate to severe spongiform changes were detected in the cerebral and cerebellar cortices, basal ganglia, thalamus, and brainstem. H-type BSE was characterized by the presence of PrP-immunopositive amyloid plaques in the white matter of the cerebrum, basal ganglia, and thalamus. Moreover, intraglial-type immunolabeled PrPSc was prominent throughout the brain. Stellate-type immunolabeled PrPSc was conspicuous in the gray matter of the cerebral cortex, basal ganglia, and thalamus, but not in the brainstem. In addition, PrPSc accumulation was detected in the peripheral nervous tissues, such as trigeminal ganglia, dorsal root ganglia, optic nerve, retina, and neurohypophysis. Cattle are susceptible to H-type BSE with a shorter incubation period, showing distinct and distinguishable phenotypes of PrPSc accumulation.     

Vaccination against Fowlpox virus via drinking water

The oral vaccination against Fowlpox was investigated via drinking water containing the F132-c strain of Fowlpox virus to be effective even though the vaccine virus-titer was 10(4) TCID (50)/dose each time. When the virus-titer of the F132-c strain was 10(4-5 )TCID(50)/dose per single drinking water vaccination, 90% or more of chickens were not protected, however, they were protected when vaccinated twice via drinking water. A weak immune response occurred by a slight infection after the first vaccination, and due to memory cells, a booster could work well after the second vaccination. These results suggest the possibility of reducing both the amount of virus required for a vaccine via drinking water and the labor cost in the field.     

Novel reovirus isolation from an Ostrich (Struthio camelus) in Japan

An orthoreovirus was isolated from an Ostrich (Struthio camelus) and rapidly identified as orthoreovirus by the rapid determination of viral RNA sequences (RDV) system and electron microscopy. Phylogenetic analysis of the sigma A protein indicated that the isolate belonged to avian species and was closely related to chicken orthoreovirus strain 138. The results of the present study indicated that an ostrich orthoreovirus is slight different from other chicken orthoreoviruses and provided evidence of diversity among avian orthoreoviruses. To our knowledge, this is the first genetic report of an orthoreovirus isolated from an ostrich.     

Improved rapid and efficient method for Staphylococcus aureus DNA extraction from milk for identification of mastitis pathogens

A rapid and efficient DNA extraction method was developed for detecting mastitis pathogens in milk. The first critical step involved cell wall disruption by bead-beating, as physical disruption using beads was more effective for DNA extraction from Gram-positive bacteria, such as Staphylococcus aureus, than enzymatic disruption using proteinase K. The second critical step involves the use of acetic acid and ammonium sulfate in the purification process, as these reagents effectively and efficiently remove the lipids and proteins in milk. Using these methods, DNA suitable for loop-mediated isothermal amplification was obtained within 30 min. Also, the rapid and sensitive detection of S. aureus in milk was possible at levels as low as 200 cfu/ml.     

Adjuvant effect of chicken interferon-gamma for inactivated Salmonella Enteritidis antigen

The adjuvant effect of chicken interferon-gamma (ChIFN-gamma) was examined for protecting chickens against intestinal colonization of Salmonella Enteritidis (SE) following oral exposure. Ten 7-week-old chickens per group were immunized with inactivated SE twice with or without co-administration of ChIFN-gamma intramuscularly, and all chickens were challenged with SE. Sera collected from immunized groups with or without ChIFN-gamma, and from unimmunized group were measured for SE antibody by agglutination test. The levels of antibodies were raised by 1 week post-immunization and did not show any difference between groups with and without ChIFN-gamma. No antibodies were detected in unimmunized group before challenge. Fecal samples from each group were cultured at 1, 4, 7, and 13 days post-challenge to determine the incidence of intestinal colonization and the numbers of SE shed into the environment. Co-administration of ChIFN-gamma, significantly reduced the incidence of intestinal colonization (P<0.05). At 13 days post-challenge, the bacterial counts of SE in organs were also reduced in ChIFN-gamma administered group. These data suggest co-administration of ChIFN-gamma with SE antigen enhances protection against SE challenge without acceleration of antibody production.