Subacute massive necrotizing myocarditis by canine parvovirus type 2 infection with diffuse leukoencephalomalacia in a puppy

Severe necrotizing myocarditis associated with canine parvovirus type 2 (CPV-2) infection and diffuse leukoencephalomalacia was recognized in a 4-week-old mongrel puppy. The cardiac lesions were characterized by severe diffuse myocardial degeneration and necrosis with occasional massive mineralization and distinct intranuclear inclusion bodies. Immunohistochemical examination revealed the presence of CPV-2 antigens in both the cytoplasm and nuclei of the myocytes. In the white matter of the cerebrum, moderate to severe diffuse necrosis with diffuse infiltration of gitter cells and occasional diffuse mineral deposits were recognized symmetrically and bilaterally. In the meningocortical area of the cerebellum, there was mild focal hemorrhage and accumulation of hemosiderin-laden histiocytes. In addition to the absence of viral antigen (as judged by immunohistochemistry), neither viral inclusions nor other vascular lesions were identified in examined sections of brain. These findings suggest that the brain lesions were not induced by direct CPV-2 infection but were related to severe myocardial lesions producing prolonged hypoxia and/or ischemia.

Peripheral neuroblastoma and primitive neuroectodermal tumor in Japanese black cattle

Peripheral neuroblastoma was found in a 1-year-old, male, Japanese black cattle (Case 1) and primitive neuroectodermal tumor was noted in 7-year-old, female, Japanese black cattle (Case 2). In Case 1, neoplastic tissue was replaced the right cranial vault and nasopharynx. A large, soft mass approximately 18 cm in diameter was also observed in the right mandibulopharyngeal area. In Case 2, a neoplastic mass of about 15 cm in diameter was found in the mandibulopharyngeal area. Histopathologically, massive necrosis showing a pseudopalisade arrangement was frequently observed in Case 1. On the contrary, Homer & Wright rosette formations of tumor cells were prominent in Case 2. Immunohistochemically, the proliferating cells in Case 1 were positive for vimentin, S-100, and neurofilament (NF) and those in Case 2 showed intense immunoreactivity for NF and neuron specific enolase, but were negative for vimentin and S-100. The different degrees of differentiation of the neoplastic cells originating from the neuroectoderm, might be reflected in their different morphological and immunohistochemical features.

Malignant aortic body tumor in a Holstein cow

A malignant aortic body tumor was observed in a 5-year-old female Holstein cow. The neoplastic mass, of 22 x 17 x 15 cm in size, was located at the base of the left atrium, having irregular lobular structures. The tumor cells had slightly eosinophilic cytoplasm, and a round or oval nucleus. Metastasis was only present in the premediastinal lymph node. The tumor cells exhibited intense immunoreactivity for neuron-specific enolase (NSE) and synaptophysin, and were moderately positive for chromogranin A. Electronmicroscopy revealed membrane-limited granules in the cytoplasm. The cultured cells were spindle in shape, and having projectional cytoplasm. They were intensely positive for NSE, synaptophysin, chromogranin A, and neurofilament (200 kD). Consequently, this case was diagnosed as a malignant aortic body tumor from the neuroecrodermal origin.

The use of feed restriction for mortality control of chickens in broiler farms

Feed restriction was attempted for the control of mortality at broiler farms. Respiratory signs were observed in both restricted-feed flocks and fully fed flocks, but they were less severe in the restricted-feed flocks. The death rate in the fully fed flocks began to rise at the age of 4 wk but did not do so in the restricted-feed flocks. Mortality in the restricted-feed flocks was significantly lower than in the fully fed flocks aged from 3 to 7 wk. The economic performance with restriction feeding was better than that with full feeding as a result of improvements in viability and feed conversion rates. Feed restriction appeared to be beneficial in decreasing the death losses.

Immunohistochemical study of constituents other than beta-protein in canine senile plaques and cerebral amyloid angiopathy

To clarify the significance of the constituents of canine senile plaques (SPs) or cerebrovascular amyloid deposits, paraffin and cryostat sections of canine brains were examined by immunohistochemistry using antibodies against cathepsin B (CB), cathepsin D (CD), cystatin C (CC), alpha-1-antichymotrypsin (ACT), heat shock protein 70 (HSP70), ubiquitin (Ubq), and apolipoprotein E (Apo E). On the cryostat sections, all types of canine SPs and cerebrovascular amyloid deposits in both arterioles and capillaries were positive for Apo E. On paraffin sections, the Apo E immunoreactivity of diffuse plaques was weak and varied according to the method of fixation or pretreatment before immunostaining. Moreover, amyloid plaques were found to contain several elements that were positive for CC, ACT, CD, and Ubq, and a subset of vascular amyloid deposits around cortical capillaries showed significant immunoreactivity for CD, CC, and ACT. In addition, vascular amyloid deposits in the arterioles showed moderate CD immunoreactivity and were intensely Apo E positive. No significant labeling of canine Sps or vascular amyloid deposits was detected when the antibodies against CB and HSP 70 were applied to the cryostat and paraffin sections. These results indicated that, of the constituents examined, Apo E might be most closely related to canine beta-amyloidosis in the early stage of this brain disorder.

Experimental production of ascites in broiler chickens using infectious bronchitis virus and Escherichia coli

Common commercial strain male broilers were intratracheally inoculated with 0.3 ml of fluid containing 10(3.7) embryo infective doses of infectious bronchitis virus (IBV) at 14 days of age and 7.5 x 10(6) colony-forming units of Escherichia coli at 18 days of age. Ascites was detected in 15 out of 100 infected birds, which was significantly higher than in a control group of 100 mock-infected birds (P < 0.01). Some parabronchi were blocked by copious exudate containing heterophils and fibrin in the infected birds at 22 days of age although these findings were not seen in the infected birds at 35 days of age or in birds with ascites. The erythrocyte packed cell volume and right ventricle/total ventricle (RV/TV) ratio of birds with ascites were higher than in birds without ascites. The RV/TV weight ratio for the infected group at the age of 35 days was higher than that of the control group. No IBV or E. coli were recovered from the ascitic birds. These findings suggest that these infectious agents induce ascites in the broilers, and then disappear until the birds suffer from ascites.

Enzymatic formation of dehydrodolichal and dolichal, new products related to yeast dolichol biosynthesis

Two new polyprenyl products in addition to dehydrodolichol and dolichol were detected by two-plate silica gel thin layer chromatography of nonpolar products formed from [1-14C]isopentenyl diphosphate and farnesyl diphosphate in the reaction with a crude 1,000 x g supernatant of yeast homogenates in the presence of NADPH. The new products were indistinguishable from authentic dehydrodolichal and dolichal. Analyses of the time-dependent and pH-dependent formation of the four products including dehydrodolichal and dolichal suggested that the biosynthetic pathway from dehydrodolichol leading to dolichal is different from that to dolichol. In double-labeled experiments with a combination of -l-14C-isopentenyl diphosphate and a [4B-3H]NADPH-generating system, the ratio of 3H- and 14C-derived radioactivities found in dolichal was six times higher than that in dolichol. A small amount of 3H-labeled dehydrodolichol was also detected. Considering the fact that dolichol is synthesized from dehydrodolichol (Sagami, H., Kurisaki, A., and Ogura, K. (1993) J. Biol. Chem. 268, 10109-10113), we propose that dehydrodolichol is a common branch point intermediate in the biosynthetic pathways leading to dolichal and dolichol and that dehydrodolichal is an intermediate in the pathway from dehydrodolichol to dolichal.

A retrospective study of canine senile plaques and cerebral amyloid angiopathy

Epidemiologic and morphologic features of canine senile plaques (SPs) and cerebral amyloid angiopathy (CAA) were examined in 69 necropsied dogs. Dogs having only SPs (diffuse plaques) frequently suffered from malignant neoplasms, and their mean age was significantly lower than that of dogs with CAA only. Morphologically, diffuse plaques showed wide distribution compared with amyloid plaques or CAA and were predominantly concentrated in the frontal cortex. We were unable to find any significant relationship between the severity of the SPs and individual age. These findings may indicate that the occurrence of canine SPs is not strictly associated with aging only and that additional factors are related to the occurrence of SPs, especially diffuse plaques.

Liver capsule thickening characterized by mesothelial cell proliferation with vascularization in broilers ascites syndrome

Thickened liver serosal membranes in 24 8-week-old male young broiler chickens with the ascitic syndrome were pathologically examined. Gross changes included inflammation of liver capsules (15/24 cases), right ventricular dilation (24/24 cases), pericarditis (5/24 cases), peritonitis (9/24 cases) and air sacculitis (7/24 cases). Histopathology revealed liver capsule thickening and focal hepatitis in all 24 cases, peri- and epi-carditis in 19 and myocarditis 11 cases. The thickened liver capsules consisted of spindle shaped-cells which reacted with anti-keratin rabbit serum and anti-vimentin monoclonal antibody, and formed cysts of varying size containing clear yellow fluid as ascitic fluid. The volume of sub-capsular fluid may have been responsible for the development of the cysts. The spindle-shaped cells were located perpendicular to the surface with thin bridges from the serosa together with a little collagen and vascularization. These changes were not observed in other serosal membranes in abdominal air sac or pericardium. We have therefore shown that the liver capsule thickening in the broilers ascites syndrome is characterized by mesothelial cell proliferation with vascularization.

Transplantation of a cell line derived from a canine benign mixed mammary tumour into nude mice

The MCM-B2 canine mammary cell line was serially transplanted into nude mice. The tumour masses consisted of elongated pleomorphic cells of varying size in the first to third passages; oval cells, becoming rounder, in the sixth to eighth passages; and cord-like, glandular and duct-like structures with compact radiating projections in the ninth and tenth passages. Ultrastructural and immunohistochemical examination of round cells confirmed their epithelial cell nature, but the morphology of the elongated and oval cells was identical with that of the original cell line. The findings suggest that the MCM-B2 cell line is a multipotential stem cell or is derived from glandular differentiation of mammary gland.

In vitro growth inhibition activities of recombinant feline interferon on all lines derived from canine tumours

To evaluate the anti-tumour effect of recombinant feline interferon (rFeIFN) against canine neoplastic cells, the antiproliferation and anti-colony-forming activities of rFeIFN were investigated in vitro, using four cell lines derived from canine tumours; oral acanthomatous epulis (MCA-B1), mammary benign mixed tumour (MCM-B2), squamous cell carcinoma (CSCC), and malignant melanoma (CMC-1). The rFeIFN had a dose-dependent inhibitory effect on the cell growth and colony formation of all the cell lines, although the degree of inhibition was lower than that in the feline cell lines used as a positive control, and the sensitivity of the cells to rFeIFN differed.

Granulomatous epididymitis related to Rhodotorula glutinis infection in a dog

A 4-year-old, male Great Dane dog developed severe swelling of the scrotum on 9 December 1991, and the testes and epididymides were removed surgically on 12 December 1992. The cut surface of the epididymides consisted of hard connective tissue and several small abcesses with slight hemorrhage. Histopathologically, the seminiferous tubules in the testes had only a few spermatogenic cells, but Sertoli cells were well preserved. Both epididymides consisted entirely of a proliferation of fibrous connective tissue, and only a few ducts deferens containing cell debris, neutrophils, and macrophages in the lumina were present. In all lesions of the epididymides, the macrophages contained periodic acid-Schiff- and Grocott's silver-positive round granules, 5-8 microns in diameter. Microbiologically, smooth salmon-pink colonies consisting of ovoidal yeast, about 10 microns in diameter, were isolated from the samples of epididymides but not from those of the testes. The isolated yeast had microbiological characteristics of Rhodotorula glutinis. From these observations, we diagnosed the present case as granulomatous epididymitis due to Rhodotorula infection.

Sequence of the canine c-yes proto-oncogene

Cloning of the canine yes oncogene was attempted from a cDNA library derived from a healthy canine spleen using a human c-yes-1 probe. The nucleotide and amino acid sequences revealed that the canine yes gene contained an open reading frame consisting of 539 amino acids. Its product had a molecular mass of 60,368 Daltons and showed 95.9 per cent and 90.4 per cent homology with human and chick p61c-yes, respectively. Moreover, the product had a myristylation signal, src homology region (SH) 3, SH2, and tyrosine kinase domains showing 98.8 per cent and 96.0 per cent homology with those of human beings and chickens, respectively. These findings indicate that the products of the canine yes gene may have non-receptor-type tyrosine kinase activity on the cell membrane, as is the case in human and chick p61c-yes.

Congenital lymphedema in a calf with lymph node dysplasia or aplasia

A 9-month-old male Japanese Black calf with subcutaneous edema in mainly both limbs was investigated. Necropsy revealed about 20 l of ascites and severe edema in the large omentum, abomasal folds, conjunctiva and rectum. Only small internal iliac and hepatic lymph nodes were found. Histopathology revealed lymph node dysplasia showing excess trabecular formation, reticular cell proliferation, and obvious dilation of both afferent and efferent lymphatics. These findings suggest that disturbance of lymphatic flow with congenital lymph nodes dyspalsia or aplasia resulted in lymphedema in this calf.

Senile plaques and other senile changes in the brain of an aged American black bear

A female American black bear (Euarctos ursus americanus) over 20 years old had shown epileptiform neurologic signs starting in March 1992 and was found dead unexpectedly 8 months later. At necropsy, pulmonary and intrabronchial hemorrhage was noted. In the brain, the leptomeninges exhibited slight thickening, and petechiae were evident in the hippocampus. Histopathologic examination of the brain revealed several senile changes: numerous senile plaques, amyloid deposition in cerebromeningeal arterioles, mineral deposition in the pallidum, and numerous corpora amylacea in the cerebellum.

Establishment of a cell line (MCM-B2) from a benign mixed tumour of canine mammary gland

A cell line was established from a benign mixed tumour of the canine mammary gland. Light microscopy of the cells cultured on plastic dishes revealed monolayer colonies. Cells that grew within the collagen gel matrix formed large three-dimensional colonies with a branching pattern. Immunohistochemically, these cells reacted intensely with anti-vimentin antiserum and mildly with anti-desmin antiserum. Ultrastructural examination revealed a large nucleus, intracytoplasmic organelles and intermediate filaments, which varied among cells. The cells possessed an abnormal chromosome number, an average of 80 per cell. Histologically, the xenografted tumour of cultured cells was similar to anaplastic carcinoma and reacted strongly with anti-vimentin antiserum, mildly with anti-desmin antiserum, and weakly with anti-keratin antiserum. The average chromosome number of cells form the xenografted tumour was the same as that of the original cultured cells. These findings suggest that the cell line might be derived from stem cells or atypical cells, and that it should be useful as model for the study of cell differentiation and proliferation in canine mammary tumours.

Giant cell glioblastoma in the frontal cortex of a dog

A dark gray mass 3 cm in diameter replacing the right frontal cortex was found in the brain of a 5-year-old male Doberman Pinscher dog at necropsy. Microscopic studies revealed that the mass consisted of a proliferation of pleomorphic tumor cells: large bizarre or plump eosinophilic cells, multinucleated giant cells, and small lymphocytic cells. These neoplastic cells at the margin of the necrotic area had a psuedopalisade arrangement and tended to proliferate around blood vessels. Immunohistochemically, the tumor cells reacted intensely with the antibody for vimentin and moderately with those for S-100 and glial fibrillary acidic protein. This canine tumor is placed in the category of glioblastoma or undifferentiated astrocytoma, which is analogous to human giant cell glioblastoma.

A cell line (MCA-B1) derived from a canine oral acanthomatous epulis

A canine oral acanthomatous epulis cell line designated MCA-B1 was established in culture. Immunohistochemically the cells reacted intensely with anti-keratin antibody and mildly with anti-vimentin antibody. An ultrastructural examination of the cells confirmed their epithelial nature. The modal chromosome number was 72 and the cloning efficiency in soft agar culture ranged from 3.4 to 16.1 per cent with a population doubling time of nine hours. MCA-B1 has since been passaged more than 70 times and maintained in culture for more than a year. Most of the characteristics of the original canine tumour cells were retained in the isolated cell line.

Antiproliferation and colony-forming inhibition activities of recombinant feline interferon (rFeIFN) on various cells in vitro

The antiproliferative and colony inhibiting activities of recombinant feline interferon (rFeIFN Type I) against various cells in vitro were examined. Feline and canine cells were both sensitive to rFeIFN. To inhibit the growth of feline cells by 50% approximately 5 x 10(2) to 1 x 10(3) U/mL rFeIFN was required and maximum activity was achieved at a concentration of 1 x 10(5) U/mL. Approximately 5 x 10(3) to 5 x 10(4) U/mL rFeIFN was necessary to inhibit the growth of canine cells by 50%. The antiproliferative and colony inhibiting activities of rFeIFN on canine cells appeared to be cell-specific and dose-dependent. However, human, monkey and hamster cells were resistant to rFeIFN. We suggest that rFeIFN might be useful for treatment of feline and some canine neoplastic conditions.

Mammary fibroadenoma in a young Holstein cow

A mammary mass approximately 60 cm in diameter, which developed in the left udder of a 17-month-old Holstein cow, was removed surgically. The mass was well demarcated from the surrounding tissues and its cut surface was lobular in appearance. Microscopically, the mass consisted of a proliferation of well differentiated ducts and mucinous connective tissue. Immunohistochemically, the proliferative stroma contained two distinct cell types; vimentin-positive fibroblasts and spindle cells positive for vimentin and actin at the periphery of the ducts. The biological features of the present mammary tumor are thought to be generally compatible with those of mammary fibroadenoma reported in humans and dogs.

The Indian soft-furred rat, Millardia meltada, a new host for Nippostrongylus brasiliensis, showing androgen-dependent sex difference in intestinal mucosal defence

Susceptibility of the Indian soft-furred rat, Millardia meltada, to infection with the intestinal helminth, Nippostrongylus brasiliensis, was examined. After subcutaneous infection with 1500 infective larvae (L3), daily faecal egg output (EPG) of both male and female animals reached a peak at 1 week post-infection (p.i.) with the same magnitude (about 20,000 epg faeces) and then rapidly decreased below detection level at around 2 weeks p.i. In male animals, however, after a transient cessation at 2 weeks p.i., parasite eggs reappeared in faeces 3 weeks afterwards, though the counts were far lower than the first peak. This phenomenon was rarely seen in female animals. High susceptibility of M. meltada to N. brasiliensis was confirmed by worm burdens. About 70% of the initial dose of larvae became adult worms in the intestine of male and female hosts. As suggested by the decline in egg counts, the majority of adult worms were expelled by 2 weeks p.i. The residual worm burden at 2 and 4 weeks p.i. was significantly higher in male than female animals. When orchidectomized males were infected with N. brasiliensis, the magnitude of residual worm burden was significantly reduced. On the other hand, ovariectomy did not affect the number of residual worms in females.

Amplification of a c-yes-1-related oncogene in canine lymphoid leukemia

Genomic DNAs from 4 canine spontaneous lymphoid neoplasms were examined by Southern blot hybridization using 7 kinds of oncogene probes. Analysis using a human c-yes-1 cDNA probe revealed amplification of the proto-oncogene in a DNA sample from a dog with lymphoid leukemia. Its degree was about 4- to 8-fold in comparison with a control DNA sample from a healthy dog. The genomic abnormality of canine c-yes-1-related oncogene may have a role in the tumorigenesis of this neoplasm, although the significance of the structural change in this oncogene remains unclear.