Prognostic value of magnetic resonance imaging in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion: 77 cases (2000-2003)

OBJECTIVE: To determine whether magnetic resonance imaging findings in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion were predictive of clinical outcome. DESIGN: Retrospective case series. ANIMALS: 77 dogs. PROCEDURE: Medical records and magnetic resonance images were reviewed; clinical outcome was classified as successful (regained ability to walk with no more than mild neurologic deficits) or unsuccessful (severe neurologic deficits persisted). The prognostic value of magnetic resonance imaging was compared with prognostic value of deep pain perception, duration of clinical signs, and rate of onset of clinical signs. RESULT: 33 (43%) dogs had areas of hyperintensity of the spinal cord greater than or equal to the length of the L2 vertebral body on T2-weighted magnetic resonance images. All 44 dogs without areas of hyperintensity on T2-weighted images had a successful outcome, but only 18 of the 33 (55%) dogs with an area of hyperintensity did. Only 5 of 16 dogs with an area of hyperintensity that had also lost deep pain perception had a successful outcome. The odds ratio for an unsuccessful outcome for a dog with an area of hyperintensity (29.87) was higher than the odds ratio for a dog that had lost deep pain perception (5.24). Duration and rate of onset of clinical signs were not associated with clinical outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggest that results of magnetic resonance imaging can be used to predict clinical outcome in dogs with paraplegia caused by intervertebral disk extrusion.     

Magnetic resonance imaging of a canine eye with melanoma

An 8-year-old Beagle dog had exophthalmos of the left eye for the last two past months. On ophthalmoscopy, the intraocular lesion could not be evaluated due to the opacity of the cornea. Ultrasonography revealed that the eyeball was distorted in shape and shifted in position, however, the precise lesion could not be identified. On magnetic resonance (MR) imaging, the lesion was observed as hyperintense on T1-weighted and hypointense on T2-weighted images, similar to those reported in human melanoma. The lesion was histologically diagnosed to be malignant intraocular melanoma. Though this is only a case report, canine ocular melanoma may show the similar characteristic MR images as in human uveal malignant melanoma.     

Pulmonary adenosquamous carcinoma in a dog

A mass that developed in the lung of a 10-year-old mixed-breed dog was pathologically examined. Histopathological examination showed papillary and tubular growth of glandular epithelium-like cells in some areas and growth of squamous cells arranged in nests in other areas, showing coexistence of adenocarcinoma and squamous cell carcinoma in a lung tumour. Immunohistochemical staining with anti-keratin-cytokeratin antibody was strongly positive for cytoplasms in both components. Electron microscopically, the neoplastic cells of the adenocarcinoma component had features of glandular cells, with microvilli, numerous free ribosomes, large round secretory granules and intercellular desmosomes. Non-keratinized squamous cells had tonofilaments and intercellular desmosomes. These findings led to the diagnosis of primary adenosquamous carcinoma, which demonstrates phenotypic profiles characteristic of both epidermal keratinocytes and glandular epithelium.     

Systemic activity of simeconazole and its derivatives in plants

The systemic activity of simeconazole (RS-2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol) and a number of its derivatives in plants has been investigated to establish which portion of the structure of the molecule contributes to this outstanding activity. The results revealed that the hydroxyl group of the simeconazole moiety is essential for vapour-phase activity and translocation from roots of the compound. They showed that the presence of a fluorine atom in the structure was not indispensable for vapour-phase activity or translocation from roots, although the fluorine atom contributed to these systemic movements. In addition, it was found that the fungicidal activity of simeconazole against Rhizoctonia solani Kühn and Blumeria graminis DC fsp hordei Marchal is potentiated by the fluorine atom, since the activity of a compound which lacked fluorine in the 4-position of the phenyl ring was inferior to that of simeconazole. A compound in which the silicon atom of simeconazole was replaced by a carbon atom showed lower antifungal activity than simeconazole, while phytotoxicity was caused in rice plants by soil drench of the compound. Therefore, the silicon atom of simeconazole may contribute to its selectivity between fungi and plants.     

Mitochondrial DNA variation in the Japanese marten Martes melampus and Japanese sable, Martes zibellina

Genetic relationship among Japanese sables, Martes zibellina and the introduced Japanese martens, Martes melampus in northern Japan was revealed by analyzing a 521-524bp DNA sequence from the cytochrome b (112bp)/transfer RNA-threonine (67bp)/tRNA-proline (65bp) and control region (277-280bp) of the mitochondrial genome. Intraspecific differences in sequences of M. zibellina and M. melampus (3.8-15.0% and 1.9-16.4%, respectively) were similar to interspecific differences between these two species (5.8-16.6%). Comparison of sequence data exhibited five haplotypes of M. melampus and four haplotypes of M. zibellina, which clustered into two groups (clusters-A and-B). Cluster-A included two haplotypes of M. melampus and two haplotypes of M. zibellina, whereas cluster-B included three haplotypes of M. melampus and two haplotypes of M. zibellina. Results of this study lead three possible explanations. Firstly, past hybridization between M. zibellina and M. melampus might have occurred. Secondary, these two species might have similar heteroplasmy of mtDNA. Thirdly, these haplotypes might have come from nuclear genome. Although further intensive studies are needed to make a conclusion, detection of hybridization with the Japanese marten are occurred or not is quite important to conserve the Japanese sable.     

Identification and morphological characteristics of dental neonatal line in sika deer (Cervus nippon)

The dental neonatal line of the sika deer (Cervus nippon) was identified experimentally using chronological labeling methods. In the enamel, prominent dark lines were observed under transmitted light, and the number of increments between the dark line and labeling line was almost consistent with the day-age at the time of labeling injection. Therefore, we identified the dark line as the enamel neonatal line. In the dentin, the bright line was observed under polarized light. Since the bright line corresponded to the enamel neonatal line, we recognized the bright line as the dentin neonatal line. Neonatal lines intersected with the enamel-dentin junction at approximately one-third cervical in the first molar. Using these features, it would make possible to distinguish the neonatal line in wild sika deer.     

Focal fatty liver in a heifer: utility of ultrasonography in diagnosis

A 30-month-old Holstein heifer presented with a history of decreased appetite and respiratory signs. Sonographic examination of the liver incidentally revealed an area of increased echogenicity between the portal vein and the gallbladder. The lesion was nonspherical and had no mass effect or displacement of the adjacent vessels. Its boundaries, to the liver, were geographic. The liver specimen was histologically compatible with a diagnosis of focal fatty liver change (FFLC). The sonographic features of focal fatty infiltration of the liver are characteristic. Recognition of the ultrasonographic data is important to differentiate FFLC from other lesions.