bluuebunny/crossref_metadata_2025 huggingface dataset:
Dilated Cardiomyopathy of Doberman Pinschers: Retrospective Histomorphologic Evaluation of Heart from 32 Cases
Authors: Everett R. M. , McGann J. , Wimberly H. C. , Althoff J.
Published: April 2003

Dilated cardiomyopathy of Doberman Pinschers (DCDP) is a progressive disease often presenting with a history of episodic weakness and syncope, or with clinical signs of predominantly left-sided congestive heart failure. A systematic dissection and histomorphologic evaluation of the heart from 32 Doberman Pinschers with a clinical diagnosis of dilated cardiomyopathy revealed a highly specific location for the characteristic myocardial lesions. The lesions of DCDP were found only in the left ventricular free wall, and in 30 cases, the lesions were characterized by myofiber degeneration and atrophy, and replacement of myocardium by dense bundles of collagen and clusters of adipocytes. In the two remaining hearts, myofiber atrophy and degeneration were accompanied by collagen deposition, but not adipocytes. In stained longitudinal (base to apex) tissue sections of the left ventricle, the lesions of DCDP were usually apparent to the unaided eye; appearing as a central linear pale zone, aligned in the long axis of the ventricular free wall. The lesions did not contain inflammatory cell infiltrates and often involved >50% of ventricular wall.
A Case of Intestinal Mycobacterium simiae Infection in an SIV-infected Immunosuppressed Rhesus Monkey
Authors: Didier A. , Mätz-Rensing K. , Kuhn E.-M. , Richter E. , Kaup F.-J.
Published: April 2003

Although Mycobacterium simiae was identified and classified more than three decades ago, only a few cases are mentioned in the current literature. After experimental simian immunodeficiency virus infection, a 9-year-old female rhesus monkey (Macaca mulatta) developed progressive immunosuppression and gastrointestinal disease very similar to the clinical and pathomorphologic features of Johne's disease, which is caused by M. paratuberculosis. Acid-fast-positive bacteria reacted immunohistochemically with antibodies against M. paratuberculosis and M. bovis but were not useful for differentiation because of a high degree of cross-reactivity. In contrast to immunohistochemistry and histopathology, biochemical methods and cycle sequencing analysis of the 16S ribosomal RNA identified M. simiae as the disease-causing pathogen. This case demonstrates the importance of molecular biological methods for the diagnosis of M. simiae infection in monkeys.
Naturally Occurring Tyzzer's Disease in a Calf
Authors: Ikegami T. , Shirota K. , Une Y. , Nomura Y. , Wada Y. , Goto K. , Takakura A. , Itoh T. , Fujiwara K.
Published: April 2003

Naturally occurring Clostridium piliforme infection (Tyzzer's disease) was found in a calf. Light microscopic examination revealed multifocal coagulative necrosis in the liver, catarrhal gastroenteritis, tracheitis and pneumonia, and thymic atrophy. Warthin-Starry staining clearly showed large filamentous bacilli in bundles or criss-cross patterns within the hepatocytes and epithelium and smooth muscle cells of the ileum and cecum. Immunohistochemistry using anti-C. piliforme RT and MSK strain antisera showed positive reaction against the bacilli. Electron microscopic examination revealed bacilli within the hepatocytes that demonstrated a characteristic vegetative form, with peritrichous flagella, and spores. The polymerase chain reaction (PCR) study using the paraffin-embedded liver sections, the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme was amplified. The characteristics of these bacilli are consistent with those of C. piliforme. The PCR technique using paraffin-embedded sections should be useful for confirming C. piliforme infection in spontaneous cases.
Prognostic Factors for Treated Canine Malignant Lymphoma
Authors: Kiupel M. , Teske E. , Bostock D.
Published: April 2003

The aim of this study was to investigate the prognostic importance of different clinical, immunohistologic and tumorproliferation characteristics in dogs with malignant lymphoma treated with chemotherapy. From 74 dogs with malignant lymphoma at least one enlarged peripheral lymph node was taken for biopsy before chemotherapy following a standardized protocol (vincristine, cyclophosphamide, prednisolone, doxorubicin, and L-asparaginase). The variables evaluated as prognostic factors were age, sex, and tumor stage, as well as histomorphologic grade (Kiel classification, Working Formulation), immunophenotype (using markers for CD3 and CD79a), and cell proliferation (Ki-67, proliferation cell nuclear antigen, mitotic index, and argyrophil nucleolar organizer regions [AgNORs]) in extirpated lymph nodes. All markers were used on routinely formalin-fixed, paraffin-embedded tissues. The AgNORs were assessed qualitatively, based on the AgNOR pattern distribution, and quantitatively using image analysis and routine counting. In both univariate and multivariate survival analyses, AgNORs were a valuable prognostic marker for the treatment of canine malignant lymphomas. Based on the results of the multivariate analysis longer survival time correlated with a B-cell type, a larger mean AgNOR area, a larger total AgNOR area, a shorter distance between two AgNORs, and a smaller AgNOR area to nucleus ratio. Longer disease-free survival time correlated with a smaller number of AgNORs per nucleus, a larger mean AgNOR area, a larger maximal AgNOR area, and a larger total AgNOR area. This study clearly demonstrates the additional benefit of the use of AgNORs in predicting treatment outcome in dogs with malignant lymphoma.
Intralobar Nephroblastematosis: Precursor Lesions of Nephroblastoma in the Sprague-Dawley Rat
Authors: Mesfin G. M.
Published: April 2003

Precursor lesions of spontaneous nephroblastoma (NB) in rats are here characterized for the first time, with a description of the progression of the tumor in prenatal, postnatal, and adult Sprague-Dawley rats (Upj:TUC[SD]spf.nb), which are genetically predisposed to the tumor. NB in the rat starts as a focal or multifocal interstitial accumulation of intensely basophilic immature (blastema) cells, invariably located in the deep renal cortex. Precursor lesions of NB (designated intralobar nephroblastematosis) and the early tumor do not overtly disrupt the overall structural organization and integrity of the kidney. However, with increasing size and neoplastic transformation, these lesions trap, compress, and displace/replace the existing renal tubules. Nephroblastematous foci occurred in one or both kidneys in tumor-bearing or non-tumor-bearing kidneys and in young and old rats. Like the precursor lesions, the early tumors in rats as young as 6 weeks of age were located in the inner cortex. Well-developed NB was comprised of blastema cells arranged in dense sheets or in ductular structures surrounded by mantles of blastema cells supported by varying amounts of fibromatous stroma. The stroma in one rat was hemangiosarcomatous (triphasic Wilms' tumor). Tumor cells were slightly pleomorphic and had varying amounts of granular cytoplasm with sparse organelles and showed junctional complexes and basal laminae whose frequency apparently depended upon whether the blastema cell tended to differentiate to epithelial or mesenchymal cells. NB in the rat was morphologically similar to immature pre-and postnatal kidneys, regardless of whether it occurred in young or old rats. The deep cortical location and interstitial infiltrative characteristics of precursor lesions of NB in the rat were analogous to intralobar nephrogenic rests, a variant of the precursor to Wilms' tumor in children.
Disseminated Blastomycosis in a Rhesus Monkey (Macaca mulatta)
Authors: Wilkinson L. M. , Wallace J. M. , Cline J. M.
Published: April 2003

An 8-year-old male rhesus monkey ( Macaca mulatta) died following a 6-day illness consisting of progressive depression, anorexia, labored abdominal breathing, coughing, and tachypnea. Gross necropsy findings included severe multifocal (miliary) granulomatous pneumonia, granulomatous splenitis, and multifocal cerebral abscesses. Histologic examination revealed 10–15-μm broad-based budding organisms within pyogranulomatous inflammatory lesions in the lung, tracheobronchial lymph node, brain, spleen, and liver. The distribution of extrapulmonary lesions was intermediate between that described for dogs and that described for humans. These findings were consistent with blastomycosis, which is previously unreported in nonhuman primates.
Exocrine Pancreatic Atrophy in German Shepherd Dogs and Rough-coated Collies: An End Result of Lymphocytic Pancreatitis
Authors: Wiberg M. E. , Saari S. A. M. , Westermarck E.
Published: April 2003

Previously published studies of the pathology of canine exocrine pancreatic insufficiency (EPI) have been based on morphological findings during the clinical phase of the disease, when atrophy of acinar parenchyma occurs. Recently, low serum trypsinlike immunoreactivity (TLI) concentration has been shown to precede clinical signs, making it possible to diagnose EPI prior to onset of the clinical disease. This study presents histological and ultrastructural findings of pancreatic biopsies from 11 German Shepherd Dogs and 2 Rough-coated Collies with subclinical EPI (SEPI). These findings were compared with those from dogs with clinical EPI ( n = 11) and healthy control dogs ( n = 5). Biopsied tissue from dogs with SEPI typically contained both normal and atrophied acinar parenchyma. The most significant finding was the marked lymphocytic infiltration, which was most prevalent at the border zone of affected and nonaffected parenchyma but had spread into the normal acinar tissue. Numerous intraacinar lymphocytes were found. Most of the lymphocytes were positive by immunostaining for CD3. In more advanced stages of destruction, the findings were characteristic of pancreatic acinar atrophy. In the atrophied parenchyma, the inflammatory reaction, if present, was less prominent. Ultrastructural changes were in accordance with those of the histological study showing infiltration of lymphocytes both in affected acini and in acini that revealed no obvious ultrastructural changes. Progressive degenerative changes of acinar cells were considered a nonspecific finding. Apoptotic death of acinar cells was occasionally found. The inflammatory reaction was clearly shown to precede the pancreatic acinar atrophy, and the findings suggested that lymphocytic pancreatitis leads to atrophy of the pancreas. The possibility that EPI is an immune-mediated disease in German Shepherd Dogs and Rough-coated Collies is discussed.
Spinal Dysraphism in a Newborn Holstein-Friesian Calf
Authors: Ohfuji S.
Published: April 2003

Spinal dysraphism, not associated with vertebral defect or arthrogryposis, was found in a 3-day-old Holstein—Friesian calf that was clinically diagnosed as having encephalopathy. The dysraphic lesion occurred in the sixth (C6) and seventh (C7) segments of the cervical spinal cord. Microscopically, the lesion was characterized by hydromyelia, syringomyelia, anomaly of the ventral median fissure, abnormal running of the myelinated nerve fibers in the white column, and absence of the central canal due to a developmental defect of the ependymal cells.
Possible Intraspinal Metastasis of a Canine Spinal Cord Nephroblastoma
Authors: Terrell S. P. , Platt S. R. , Chrisman C. L. , Homer B. L. , de Lahunta A. , Summers B. A.
Published: April 2003

A 2-year-old Basset Hound was admitted to the University of Florida Veterinary Medical Teaching Hospital with progressive spastic paraparesis. At necropsy, intradural extramedullary tumors produced areas of spinal cord swelling and softening in spinal cord segments T11–T12 and L4–L6. Histologic examination of the masses revealed sheets of polygonal blastemal cells, epithelial cells forming tubules and rosettes, and embryonal glomeruloid-like structures in the thoracic mass. Cells in the lumbar mass were less differentiated, forming rare tubules and no glomeruloid-like structures. The occurrence of two tumors in the spinal cord along with the less differentiated appearance of the lumbar tumor raises the possibility that the lumbar mass arose as a result of intraspinal metastasis. To our knowledge, this is the first report of multifocal or metastatic canine spinal nephroblastoma. In addition, the vimentin and cytokeratin immunohistochemical staining characteristics of these spinal cord nephroblastomas are described.
Lysosomal Storage Disease Caused by Sida carpinifolia Poisoning in Goats
Authors: Driemeier D. , Colodel E. M. , Gimeno E. J. , Barros S. S.
Published: April 2003

A neurologic disease characterized by ataxia, hypermetria, hyperesthesia, and muscle tremors of the head and neck was observed for 2 years in a flock of 28 Anglo-Nubian and Saanen goats on a farm with 5 ha of pasture. Six newborns died during the first week of life, and five abortions were recorded. The predominant plant in the pasture was Sida carpinifolia. The disease was reproduced experimentally in two goats by administration of this plant. Three goats with spontaneous disease and the two experimental animals were euthanatized and necropsied. No significant gross lesions were observed. Fragments of several organs, including the central nervous system, were processed for histopathology. Small fragments of the cerebellar cortex, liver, and pancreas of two spontaneously poisoned goats and two experimentally poisoned goats were processed for electron microscopy. Multiple cytoplasm vacuoles in hepatocytes, acinar pancreatic cells, and neurons, especially Purkinje cells, were the most striking microscopic lesions in the five animals. Ultrastructural changes included membrane-bound vacuoles in hepatocytes, Kupffer cells, acinar pancreatic cells, Purkinje cells, and the small neurons of the granular cell layer of the cerebellum. Paraffin-embedded sections of the cerebellum and pancreas were submitted for lectin histochemical analysis. The vacuoles in different cerebellar and acinar pancreatic cells reacted strongly to the following lectins: Concanavalia ensiformis, Triticum vulgaris, and succinylated Triticum vulgaris. The pattern of staining, analyzed in Purkinje cells and acinar pancreatic cells coincides with results reported for both swainsonine toxicosis and inherited mannosidosis.
Polysaccharide Storage Myopathy in Morgan, Arabian, and Standardbred Related Horses and Welsh-cross Ponies
Authors: Valentine B. A. , McDonough S. P. , Chang Y.-F. , Vonderchek A. J.
Published: April 2003

Polysaccharide storage myopathy is an equine neuromuscular disorder characterized by accumulation of glycogen-related polysaccharide inclusions within skeletal muscle fibers. The pathologic criteria for diagnosis of this disorder are somewhat controversial; however, periodic acid-Schiff-positive, amylase-resistant inclusions are considered pathognomonic. Although these inclusions are most often found in affected horses related to the Quarter Horse, draft horse, and Warmblood breeds, this report describes these characteristic inclusions in muscle of five horses from nonrelated breeds (two Morgans, one Arabian, one Arabian X Thoroughbred, and one Standardbred) and two Welsh cross ponies. Affected horses had histories of recurrent exertional rhabdomyolysis, and one developed progressive weakness leading to increased recumbency. The affected ponies were part of an unrelated research project and had no apparent clinical signs.
An Encephalopathy with Argyrophilic Inclusions in a Holstein—Friesian Cow
Authors: Nakamura N. , Yamaguchi H. , Furuoka H. , Matsui T.
Published: April 2003

The brain of a 6-year-old Holstein cow, which showed progressive neurologic symptoms during several months, was examined by histopathologic methods. Many round or oval-shaped cytoplasmic inclusions were observed, mainly in neurons of the temporal lobe and the hippocampus. Those inclusions were faintly eosinophilic with hematoxylin and eosin and positive with Bielschowsky's silver stain. Immunohistochemically, the inclusions were recognized by antiubiquitin and antiphosphorylated tau antibodies. Ultrastructurally, the inclusions were globular and well demarcated from the rest of the cytoplasm, lacked limiting membranes, and were mainly composed of straight fibrils about 15 nm in width. The structure of the inclusions was similar to that of Pick bodies in Pick's disease of humans. The pathogenesis of this bovine condition is not known.
Mammary Adenocarcinoma in a Male Squirrel Monkey (Saimiri sciureus)
Authors: Waggie K. S. , Tolwani R. J. , Lyons D. M.
Published: April 2003

A nodule was identified within the right mammary gland of a 16-year-old male squirrel monkey (Saimiri sciureus). The mass was excised and diagnosed as a mammary adenocarcinoma. The monkey developed congestive heart failure 1.5 years later and was euthanatized. At necropsy, a subcutaneous mass was found in the right axillary region. Histologically, the mass was identified as a lymph node whose architecture was effaced by neoplastic cells resembling those of the mammary tumor. Metastasis to internal organs was not observed. This is the first reported case of a mammary tumor in a New World primate and the only known case of mammary cancer in a male nonhuman primate.
Common Metastatic Carcinoma of California Sea Lions (Zalophus californianus): Evidence of Genital Origin and Association with Novel Gammaherpesvirus
Authors: Lipscomb T. P. , Scott D. P. , Garber R. L. , Krafft A. E. , Tsai M. M. , Lichy J. H. , Taubenberger J. K. , Schulman F. Y. , D. Gulland F. M.
Published: April 2003

Tissues from 10 adult California sea lions ( Zalophus californianus, seven females and three males) that had metastatic carcinoma in sublumbar area lymph nodes were examined histologically. A distinctive epithelial proliferative lesion interpreted as intraepithelial neoplasia was found in genital tracts of all ten animals; in vagina (5/7), cervix (7/7), uterus (3/7), penis (3/3) and prepuce (3/3). Intraepithelial neoplasia closely resembled metastatic carcinomas and was directly contiguous with invasive carcinoma in one animal. Rare eosinophilic intranuclear inclusion bodies were found in penile and preputial intraepithelial neoplasia (one animal), cervical intraepithelial neoplasia (one animal), invasive cervical carcinoma (one animal) and metastatic carcinoma (two animals). Electron microscopic examination of tissues from two sea lions (one with intraepithelial neoplasia and one with metastatic carcinoma) demonstrated viral particles consistent with a herpesvirus. An immunohistochemical stain for the latent membrane protein of Epstein-Barr virus was positive in intraepithelial neoplasia in one sea lion. Herpesvirus DNA sequences were detected by consensus primer polymerase chain reaction (PCR) in metastatic carcinomas from all four sea lions from which unfixed tumor samples were available. Results of sequencing were consistent with a novel gammaherpesvirus in the genus Rhadinovirus. DNA extracted from the four metastatic carcinomas also was tested for papillomavirus by Southern blot and PCR with consensus papillomavirus primers; all samples were negative by both methods. These findings support the genital origin of the sea lion carcinoma and implicate a novel gammaherpesvirus as a possible cause.
In Situ Hybridization Detection of Bovine Respiratory Syncytial Virus in the Lung of Experimentally Infected Lambs
Authors: Masot A. J. , Kelling C. L. , López O. , Sur J. H. , Redondo E.
Published: April 2003

We studied the distribution of bovine respiratory syncytial virus (BRSV) RNA in lungs of experimentally inoculated lambs by in situ hybridization at different times postinoculation. The probe used for in situ hybridization was prepared by reverse transcription of BRSV RNA, followed by polymerase chain reaction (PCR) amplification of the cDNA. Twenty-five Merino lambs of both sexes with a live weight of 17 ± 3 kg received an intratracheal inoculation of 20 ml saline solution containing 1.26 × 106 TCID50 BRSV (strain NMK7)/ml. Lambs were slaughtered 1, 3, 7, 11, and 15 days postinoculation (PID). Bronchial and bronchiolar epithelial cells were positive for BRSV nucleic acid by ISH at 1, 3, 7, and 11 PID. However, alveolar epithelial cells contained positive cells at 1, 3, and 7 PID. Cells containing viral RNA were detected from 1 to 11 PID in exudate within bronchial and bronchiolar lumina and from 3 to 7 PID in alveolar exudates. Positive hybridization signals were identified in interstitial mononuclear cells and in bronchi-associated lymphoid tissue from 3 to 11 PID. Mononuclear cells were located in peribronchiolar tissue and interalveolar septa. The highest signal intensity in positive cells was observed at 3 and 7 PID, coinciding with the most important histopathological findings.
Clinical, Hematologic, and Immunophenotypic Characterization of Canine Large Granular Lymphocytosis
Authors: MCDonough S. P. , Moore P. F.
Published: April 2003

Clinical, hematologic, and immunophenotypic data were studied in 25 dogs with large granular lymphocyte (LGL) lymphocytosis. Primarily large-breed dogs were affected, with an average age at initial diagnosis of 10 years (range 5-14 years). All dogs had persistent (>4 months) LGL lymphocytosis except for three that were euthanized with aggressive disease. Splenomegaly was reported in 12 of 20 dogs in which splenic size was evaluated. The clinical course was heterogeneous and dogs were divided into four groups based on similar clinical and hematologic findings: acute leukemia (3/25), persistent lymphocytosis with anemia (12/25), persistent lymphocytosis without anemia (8/25), and reactive lymphocytosis (2/25). Immunophenotypes varied within groups but were homogeneous among cells from the same patient except in the two dogs classified as reactive LGL lymphocytosis. Analysis of T-cell receptor (TCR) usage identified three main LGL lineages. TCRαβ was expressed in 15/25 (60%) cases. TCRγδ was expressed in 8/25 (32%) cases, and 2/25 (8%) cases were CD3-, compatible with NK cells. β2 integrin expression was distinctive. CD11a was consistently expressed, while CD11b was absent. CD11c was expressed only weakly in 16/25 (64%) cases. The leukointegrin αdβ2 was highly prevalent on all LGL lineages, being expressed in 23/25 (92%) cases. Prominent involvement of the spleen, relative sparing of bone marrow, an unexpectedly large proportion of γδ T-cell LGLs, and the distinctive β2 integrin expression pattern on diverse lineages of LGLs suggest the disease arises from unique populations of lymphocytes that preferentially localize in the splenic red pulp.
Axonal and Neuronal Amyloid Precursor Protein Immunoreactivity in the Brains of Guinea Pigs Given Tunicamycin
Authors: Finnie J. W. , Manavis J. , Blumbergs P. C. , Kuchel T. R.
Published: April 2003

Amyloid precursor protein (APP) immunocytochemistry was used to study axonal and neuronal changes in guinea pig brains exposed to tunicamycin. Substantial axonal injury was found in ischemic-hypoxic foci and more generally, but this injury was not readily appreciable in conventionally stained sections. Neuronal perikaryal APP expression was also widely distributed, possibly as an acute phase response to this neurotoxin.
Expression of Cyclooxygenase-2 in Canine Renal Cell Carcinoma
Authors: M. Khan K. N. , Stanfield K. M. , Trajkovic D. , Knapp D. W.
Published: April 2003

Cyclooxygenase-2 (COX-2) has been shown to be the primary enzyme responsible for prostaglandin production during inflammation but is absent in most tissues under normal physiological states. High levels of COX-2 expression have been observed in the macula densa and thick ascending limbs of fetal kidneys; this expression declines to minimal levels during renal maturation. We hypothesized that the neoplastic cells of renal cell carcinoma (RCC) may revert to high expression of COX-2, and we evaluated its expression in three spontaneous cases of canine RCC by using immunohistochemical methods. The neoplastic cells of two of the three cases exhibited moderate to marked COX-2 immunoreactivity. These results suggest that some canine renal cell carcinomas express high levels of COX-2, which may play a role in the modulation of neoplastic cell growth.
Ocular Histopathology of Ehrlichial Infections in the Dog
Authors: Panciera R. J. , Ewing S. A. , Confer A. W.
Published: April 2003

Histologic examination of eyes and brains of 27 dogs experimentally infected with either Ehrlichia canis, E. ewingii, E. chaffeensis, or human granulocytic ehrlichia (HGE) was conducted in the course of several experiments, the primary objectives of which were to investigate the susceptibility of the domestic dog to infection with various ehrlichial species and to assess the ability of ixodid tick species to acquire and transmit those infections. Uveitis and meningitis occurred in each of the dogs infected with E. canis but was not observed in dogs infected with the other Ehrlichia species. The inflammatory infiltrate was predominantly lymphocytic, monocytic, and plasmacytic; granulocytes were notably few. Ocular inflammation was most common and most intense in the ciliary body, becoming less intense in the choroid, iris, and retina, respectively. Meningitis was often accompanied by mild neuroparenchymal vascular cuffing and gliosis. The meningeal inflammatory cell infiltrate included a prominent monocyte population. Ocular and meningeal lesions were present in all E. canis-infected dogs from 22 through 200 days postexposure. Neither ocular nor brain lesions were observed with any of the other ehrlichial infections.
Rapid Transplacental Infection with Bovine Pestivirus Following Intranasal Inoculation of Ewes in Early Pregnancy
Authors: Swasdipan S. , Bielefeldt-Ohmann H. , Phillips N. , Kirkland P. D. , McGowan M. R.
Published: April 2003

Despite the importance of congenital viral infections in both veterinary and human medicine, only limited experimental work has been carried out to elucidate the mechanisms involved in transplacental virus infections. To further an understanding of fetal infection with pestiviruses, the distribution of bovine pestivirus in the uterine and fetal tissues of ewes in early pregnancy, following a natural route of infection, was investigated. On the 18th day of pregnancy, nine ewes were inoculated by the intranasal route with 1 X 105 50% tissue culture infective doses of an Australian isolate of noncytopathic bovine pestivirus (bovine viral diarrhea virus genotype 1). All ewes were ovariohysterectomized at approximately 100 hours postinfection. Samples from the reproductive tract and conceptus were examined histologically and tested for bovine pestivirus by nested reverse transcription–polymerase chain reaction (RT-PCR) and immunohistochemistry and for interferon-tau mRNA expression by nonnested RT-PCR. Although no histopathologic changes were observed in the maternal or fetal tissues, virus was detected in the reproductive tract of all nine ewes and in all of the conceptuses examined. At the time of surgery, only two of the nine ewes were demonstrably viremic. This study demonstrates that bovine pestivirus can spread from a natural site of infection to the ovine fetus within 4 days in the absence of maternal immunity and despite the presence of interferon expression in the reproductive tract.
A Case of Angiokeratoma
Authors: Vala H. , Esteves F.
Published: April 2003

Angiokeratoma is described by various authors as a rare variant of the hemangioma in the dog, characterized by a vascular component, like all types of vascular neoplasms, but also by an epithelial component. A case of angiokeratoma is described in a male 8-year-old dog. The tumor was located in heavily pigmented skin on the anterior surface of the front limb and not in the more usual previously described locations, eyelid and conjunctiva. Microscopic examination revealed a well-circumscribed mass with irregular hyperplasia of the epidermis and dilated vascular spaces filled with blood in the superficial dermis.
Tyzzer's Disease in a Neonatal Rainbow Lorikeet (Trichoglossus haematodus)
Authors: Raymond J. T. , Topham K. , Shirota K. , Ikeda T. , Garner M. M.
Published: April 2003

A captive-born 8-day-old male rainbow lorikeet ( Trichoglossus haematodus) was found dead. Histologically, there were necrotizing hepatitis, myocarditis, and ventriculitis. Silver stain revealed argyrophilic filamentous bacilli within hepatocytes, smooth myofibers of the gizzard, and cardiac myofibers surrounding foci of necrosis. Immunohistochemistry using anti- Clostridium piliforme RT and MSK strain antisera reacted positively against bacilli within hepatocytes, cardiac myofibers, smooth myofibers of the gizzard, and splenic and intestinal macrophages. Polymerase chain reaction (PCR) assay of paraffin-embedded liver, heart, gizzard, spleen, and small intestine amplified the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme. The results of histopathology, immunohistochemistry, and PCR are consistent with C. piliforme infection in this lorikeet.
Granulomatous Enteritis and Lymphadenitis in Iberian Pigs Naturally Infected with Lawsonia intracellularis
Authors: Segalés J. , Fernández-Salguero J. M. , Fructuoso G. , Quintana J. , Rosell C. , Pozo J. , De Arriba M. L. , Rubio P. , Domingo M.
Published: April 2003

Intestinal samples and/or lymph nodes of two Iberian pigs from two different farms were submitted for histopathologic examination. Both pigs had proliferation of ileal and/or cecal crypts with almost complete absence of goblet cells. Infection by Lawsonia intracellularis was demonstrated by immunohistochemistry and polymerase chain reaction assay. The mesenteric lymph node of one pig had moderate lymphocyte depletion with granulomatous inflammation of the lymph node parenchyma. Histiocytes and multinucleated giant cells from the lymph node of one pig contained L. intracellularis antigen within the cytoplasm. This pig had also porcine circovirus type 2 (PCV-2) infection, but nucleic acid and antigen of this virus were not demonstrated in the lymph node. The second pig had lymphocyte depletion and marked granulomatous inflammation in Peyer's patches. Histiocytes and multinucleated giant cells in areas of granulomatous inflammation contained L. intracellularis antigen; no PCV-2 nucleic acid or antigen was detected in the tissues of this pig. This is the first description of granulomatous ileitis and lymphadenitis associated with L. intracellularis infection.
Colocalization of Porcine Reproductive and Respiratory Syndrome Virus and Porcine Circovirus 2 in Porcine Dermatitis and Nephropathy Syndrome by Double-Labeling Technique
Authors: Choi C. , Chae C.
Published: April 2003

Simultaneous detection of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus 2 (PCV2) was achieved by a double-labeling technique using a combination of immunohistochemistry and in situ hybridization in five pigs with naturally occurring porcine dermatitis and nephropathy syndrome (PDNS). Both PRRSV and PCV2 were isolated from a homogenate of pooled skin and kidney from three pigs. PRRSV RNA was demonstrated by reverse transcription polymerase chain reaction (PCR) in skin, kidney, lymph node, and tonsil homogenates from all pigs. PCV2 DNA was demonstrated by PCR in kidney, lymph node, tonsil, liver, and lung homogenates from all pigs. For double-labeling studies, the tissue samples were processed sequentially, first by immunohistochemistry and then by in situ hybridization. The most consistent and intense staining for PRRSV and PCV2 was in the kidney, lymph node, and tonsil. PRRSV antigen and PCV2 DNA were also detected in the skin. This morphologic study is the first to confirm the presence of both PRRSV and PCV2 in the same tissues in pigs with naturally occurring PDNS.
Immunohistochemical Evaluation of a Malignant Pheochromocytoma in a Wolfdog
Authors: Sako T. , Kitamura N. , Kagawa Y. , Hirayama K. , Morita M. , Kurosawa T. , Yoshino T. , Taniyama H.
Published: April 2003

A malignant pheochromocytoma with multiple metastases was diagnosed in a 7-year-old male wolfdog that resulted from a cross between an eastern timber wolf (Canis lupus lycaon) and an Alaskan malamute. A yellowish white neoplastic mass approximately 10 cm diameter was found in the right adrenal gland. The neoplasm penetrated through the wall of the caudal vena cava. A diagnosis of pheochromocytoma was established by histopathologic and immunohistochemical procedures. Immunohistochemically, the neoplastic cells expressed chromogranin A, substance P, synaptophysin, Leu-7, protein gene product 9.5, methionine- enkephalin, S100 protein, and galanin. Multiple metastatic tumors were found in the kidneys, spleen, lungs, heart, and liver.
Spontaneous Complex Pheochromocytoma in a Fischer 344 Rat
Authors: Martinez M. J. , Mog S. R.
Published: April 2003

A spontaneous complex pheochromocytoma was diagnosed in the adrenal gland of an aged female Fischer 344 rat. This expansile neoplasm consisted of pheochromocytoma and areas of ganglioneuroma. The supporting stroma of both neoplastic components contained spindle-shaped cells, which also formed large fascicles. Immunohistochemically, pheochromocytoma cells stained for synaptophysin and chromogranin, scattered ganglioneuroma cells stained for neurofilament protein, and the spindle-shaped stromal cells were positive for S-100 protein. Special stains demonstrated Nissl substance in the ganglioneuroma cells and nerve fibers in the fascicles.
Granular Cell Tumor of the Canine Central Nervous System: Two Cases
Authors: Higgins R. J. , Lecouteur R. A. , Vernau K. M. , Sturges B. K. , Obradovich J. E. , Bollen A. W.
Published: April 2003

Although pure granular cell tumors have been reported in various sites in the dog, only one tumor has been reported in the central nervous system. Two dogs presented with neurologic signs had brain lesions detected by magnetic resonance imaging in the area of the olfactory bulbs and frontal cortex. In both dogs, a clinical diagnosis of a granular cell tumor was made from tissues obtained from stereotactic biopsies guided by computed tomography. Surgical removal of the tumors was followed by histopathologic, ultrastructural, and immunocytochemical characterization. Although not conclusive, these studies indicated that the granular cells were not of leucocyte origin but may have been derived from the meninges. One dog died 12 months after surgery, and the other was alive 4 months later.
Characterization of the Inflammatory Infiltrate in Canine Chronic Hepatitis
Authors: Boisclair J. , Doré M. , Beauchamp G. , Chouinard L. , Girard C.
Published: April 2003

Canine chronic hepatitis (CCH) is a progressive inflammatory disease of unknown etiology. To characterize the inflammatory infiltrate, 16 dogs with CCH were selected and classified into three groups based on the stage of fibrosis, as evaluated with Masson's trichrome stain. The inflammatory infiltrate in each liver section was immunohistochemically characterized and evaluated using CD3, lysozyme, λ and κ light chain, and α-smooth muscle actin antibodies. Numerous breeds were affected, and middle-aged females predominated in this select group. Necroinflammatory activity progressively increased and then waned as the hepatitis progressed to cirrhosis. CD3+ lymphocytes were the most numerous lymphoid cells in dogs with CCH. Degenerate hepatocytes were occasionally surrounded by CD3+ lymphocytes. Necrosis was positively correlated with the number of CD3+ lymphocytes. The λ and κ light chain-positive cell infiltrate was variable but generally mild. A positive correlation between the λ and κ light chain-positive cells and the portal α-smooth muscle actin was found. The number of α-smooth muscle actin-positive cells (myofibroblasts) in portal triads and fibrous septa was positively correlated with the stage of fibrosis. In contrast, no correlation was found between the number of lysozyme-positive cells (Kupffer cells) and the stage of fibrosis. These results further support the idea of an immune-mediated process in CCH and suggest that periductular myofibroblasts play an important role in canine liver fibrogenesis.
Uroplakin Expression in the Urothelial Tumors of Cows
Authors: Ambrosio V. , Borzacchiello G. , Bruno F. , Galati P. , Roperto F.
Published: April 2003

Expression of uroplakins (UPs) was investigated in 20 bladder tumors from cows that had been suffering from chronic enzootic hematuria for several years. In dysplastic urothelium and papillomatous proliferations, UP expression was evident both as luminal and intercellular staining. UPs appeared to clearly define the plasma membrane of luminal cells and the borders of cells placed in deeper layers, whether or not these intermediate cells were adjacent to superficial ones. Occasionally, some intermediate cells showed a remarkable cytoplasmic immunoreactivity. The pattern of UPs in grade I tumors was characterized by an evident discontinuity of luminal staining and by the presence of numerous intermediate cells showing a diffuse intracytoplasmic positivity for UPs. In grade II tumors, there was a decrease of luminal and intermediate cells showing UP expression and an apparent increase of clusters of intermediate cells with intracytoplasmic reactivity for UPs. In grade III tumors, immunoreactivity was heterogeneously distributed and a severe loss of UP-positive luminal and intermediate cells could be seen. Focally, superficial and deeper cells showed strong membraneous immunoreactivity that marked and delimited single cells, with complete circumferential peripheral staining clearly evident. UP expression in bladder tumors of cows reported in this study is similar to the UP pattern of some urothelial tumors in humans. Although UP expression is remarkably changed in bladder carcinogenesis of cattle, the UP gene(s) remains expressed during cell transformation and tumor progression.
Uterine Angiolipoleiomyoma in a Dog
Authors: Boisclair J. , Doré M.
Published: April 2003

An 11-year-old crossbred Pomeranian bitch displayed a large intramural, well-delineated uterine mass in one horn, near the junction with the uterine body. The mass was composed largely of mature adipose tissue, smooth muscle cells singly and in small clusters, anomalous medium-size and large arteries, and multifocal islands of cartilaginous and osseous tissues. Smooth muscle cells stained positively for desmin, and adipocytes and chondrocytes were positive for S-100 protein. This tumor has histologic and immunohistochemical features compatible with human uterine angiolipoleiomyoma, a rare tumor that has never been reported in the veterinary literature. This benign tumor is believed to be of a choristomatous nature.
Cats Differ from Mink and Ferrets in Their Response to Commercial Vaccines: A Histologic Comparison of Early Vaccine Reactions
Authors: Eggers Carroll E. , Dubielzig R. R. , Schultz R. D.
Published: April 2003

Early histologic changes in lesions at vaccine sites were compared in cats, mink, and ferrets. Twenty-four 4-month-old cats, 20 4-month-old mink, and 20 12-month-old ferrets were vaccinated with three rabies virus vaccines, two feline leukemia virus vaccines, alum adjuvant, and saline. Injection sites were excised at selected time points up to 21 days postvaccination. Histologic examination of the tissue revealed significant differences among the cats, mink, and ferrets in the local response to the commercial vaccines. When compared with ferrets and mink, cats had more lymphocytes in response to all three rabies vaccines. Production of fibroblasts, collagen, and macrophages differed among the three killed aluminum-adjuvanted vaccines in cats but did not differ significantly in mink or ferrets. Cats produced fewer binucleate cells than did mink or ferrets in response to the two adjuvanted leukemia virus vaccines. Differences seen in early tissue response of cats to commercial vaccines may be related to the increased predisposition of cats to vaccine-associated sarcomas.
A Variant of Pulmonary Alveolar Microlithiasis in nackt Mice
Authors: Starost M. F. , Benavides F. , Conti C. J.
Published: April 2003

Four adult mutant nackt mice, which demonstrate alopecia and CD4+ T-cell deficiency, and two outbred SENCAR mice (sentinels) were presented for routine health surveillance. Lesions were not observed at necropsy. Microscopically, all four nackt mice demonstrated multiple concretions that were 30–100 μm in diameter, irregularly rounded to oval, nonbirefringent, and amphophilic to basophilic. Many of the concretions appeared attached to or within the alveolar walls of all lung lobes. Approximately half of the concretions had irregular fracture lines. All concretions were periodic acid-Schiff positive, and Von Kassa staining revealed diffuse calcification. None of the concretions were associated with inflammatory cell infiltrates, and metaplastic ossification was not evident. A diagnosis of pulmonary alveolar microlithiasis, a rare disease in both humans and animals, was made based on the size and location of the concretions and the lack of an inflammatory response. This is the first report of a laboratory mouse demonstrating pulmonary alveolar microlithiasis.
Pancreatic Necrosis and Ventricular Erosion in Adenovirus-associated Hydropericardium Syndrome of Broilers
Authors: Nakamura K. , Tanaka H. , Mase M. , Imada T. , Yamada M.
Published: April 2003

Seven 19-day-old broiler chickens affected with hydropericardium syndrome (HPS) with pancreatic necrosis and gizzard erosions were investigated pathologically and virologically. Mortality increased after 13 days of age in a flock on a broiler farm. The mortality rate of the flock reached 10% by 19 days of age. Macroscopically, the chickens had hydropericardium (the characteristic gross change of HPS), pinpoint white foci in the pancreas, and ventricular erosions. Histologically, the chickens had multifocal hepatic necrosis with intranuclear inclusions in hepatocytes, a marked increase of macrophages in the spleen and lung, mild epicardial edema, multifocal necrosis of pancreatic acinar cells with intranuclear inclusions, focal necrosis of the ventricular koilin layer, and degeneration of the ventricular glandular epithelium with intranuclear inclusions. Immunohistochemically, intranuclear inclusions in the liver, pancreas, and ventriculi were stained positively against group I avian adenovirus (GIAAV) antigens. Ultrastructurally, 67-nm diameter viral particles were present in intranuclear inclusions. Virologically, serotype 4 of GIAAV was isolated from the liver, heart, and kidney of affected chickens. The pathologic changes of the present cases differ from previous cases of HPS; therefore, the present strain of GIAAV may have different pathogenicity for chickens than the previous virus strain of HPS.
Endometrial Hyperplasia and Mineralization in Zoo Felids Treated with Melengestrol Acetate Contraceptives
Authors: Munson L. , Gardner I. A. , Mason R. J. , Chassy L. M. , Seal U. S.
Published: April 2003

Melengestrol acetate (MGA) contraceptives are widely used in zoo felids to regulate fertility and may have deleterious effects on endometrial health. To determine whether MGA exposure was associated with endometrial disease, the genital tracts of 212 zoo felids (99 MGA treated and 113 control) representing 23 species were evaluated. Adenomatous and cystic hyperplasia were prevalent in both MGA-treated (85%) and control (61%) groups, and the risk of developing these lesions increased with age. Treatment with MGA further increased the risk of developing advanced hyperplasia regardless of dose, and treatment for >72 months significantly elevated that risk, whereas parous animals had a lower risk. Endometrial polyps, fibrosis, adenomyosis, and hydrometra occurred in both MGA-treated and control animals. MGA treatment was associated with an increased risk of hydrometra and mineralization but not of adenomyosis, polyps, or fibrosis after adjusting for advanced hyperplasia. Acute or chronic endometritis were associated with advanced hyperplasia but not with MGA treatment. These results indicate that proliferative and inflammatory endometrial lesions are common spontaneous diseases in zoo cats, and MGA contraceptives increase the risk of some diseases. The association of MGA with endometrial lesions that could impair fertility should be considered when using this contraceptive in genetically valuable felids.
Expression and Significance of p53, Rb, p21/waf-1, p16/ink-4a, and PTEN Tumor Suppressors in Canine Melanoma
Authors: Koenig A. , Bianco S. R. , Fosmire S. , Wojcieszyn J. , Modiano J. F.
Published: April 2003

The role of tumor suppressor genes in the pathogenesis of canine melanoma is incompletely understood. The genes encoding the tumor suppressors p53, Rb, p21 ( waf-1), p16 ( ink-4a), and PTEN have been postulated to contribute to the pathogenesis of melanoma in humans and experimental animal models. To assess whether inactivation of these genes similarly contributes to the origin and progression of canine melanoma, we examined their expression in seven distinct canine melanoma cell lines and in 31 retrospective samples (representing 29 dogs) of spontaneous canine melanoma. Various patterns suggestive of loss of tumor suppressor function emerged in these cell lines. The most frequently observed abnormality was loss or significant reduction of p16 expression in six of seven cell lines and in 21 of 26 tumor samples. Loss or significant reduction of PTEN expression was seen in four of seven cell lines and in 13 of 27 tumor samples. Although p53 was detectable in all the cell lines and in 24 of 30 tumors, exclusion of p53 from the nuclear compartment was observed in each of the cell lines and in 18 of 25 tumor samples. These results indicate that loss of function of these tumor suppressor proteins is a common occurrence that may contribute to the origin of canine melanoma. In our sample population, abnormalities in the expression or localization of one or more tumor suppressor proteins occurred with similar frequency in malignant and benign tumors; thus, additional work is necessary to determine how these proteins may impact disease progression and response to therapy.
Globoid Cell-like Leukodystrophy in a Domestic Longhaired Cat
Authors: Sigurdson C. J. , Basaraba R. J. , Mazzaferro E. M. , Gould D. H.
Published: April 2003

Globoid cell leukodystrophy (GLD; Krabbe disease), is a rare heritable metabolic disorder in humans, dogs, mutant twitcher mice, and rhesus monkeys that is caused by a deficiency in the lysosomal enzyme galactocerebrosidase (GALC). GALC deficiency results in the accumulation of psychosine, which is toxic to oligodendrocytes and Schwann cells of the central and peripheral nervous systems. Clinical signs include hypotonia, mental regression, and death by 2 years of age in most human patients. Here we describe a domestic longhaired kitten with rapidly progressive neurologic disease and brain and spinal cord lesions characteristic of GLD. Pathologic hallmarks of the disease reflect the loss of oligodendrocytes and include myelin loss, gliosis, and the perivascular accumulation of large mononuclear cells with fine cytoplasmic vacuoles (globoid cells) in the peripheral and central nervous systems. Globoid cells were CD68 and ferritin positive, confirming their monocytic origin, and cytoplasmic contents were nonmetachromatic and periodic acid-Schiff positive.