bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the Age Resistance of Swine to Group A Rotavirus Infection
Authors: Gelberg H. B.
Published: March 2010

To determine whether swine become naturally age resistant to group A rotavirus infection, colostrum-deprived, rotavirus-naive newborn pigs that were raised in isolation ( n = 34) were studied. Neonatal pigs and pigs 1, 2, 4, 6, 8, 10, and 12 weeks of age were inoculated orally with group A porcine rotavirus or mock inoculum and euthanatized at 24, 31, or 48 hours post-infection. Nine sections of small intestine, cecum, and colon were harvested and immunohistochemically examined for evidence of rotavirus replication within enterocytes. Infectivity was semiquantified by intestinal segment, and a composite score was obtained for each animal. In pigs inoculated at 1 week of age, enterocyte infection was mild and scattered; all other pigs became infected regardless of age or region of intestine, and older animals that became infected had infectivity scores similar to those of younger animals. In a second more limited study, pigs raised in the same isolation environment ( n = 11) but previously exposed to virus and demonstrating rotavirus serum antibody had a much lower degree of enterocyte infection at 8, 10, and 12 weeks of age (2, 4, and 6 weeks, respectively, after initial exposure to virus). Age resistance to clinical rotavirus disease in swine is due to factors other than an age-dependent development of resistance of enterocytes to infection, at least through 12 weeks of age.
Immune Complex-mediated Glomerulonephritis Associated with Bacterial Kidney Disease in the Rainbow Trout (Oncorhynchus mykiss)
Authors: Sami S. , Fischer-Scherl T. , Hoffmann R. W. , Pfeil-Putzien C.
Published: March 2010

Rainbow trout ( Oncorhynchus mykiss) developed a post-infectious chronic membranous glomerulonephritis 15 months after they had been experimentally infected with Renibacterium salmoninarum. Histologically, peritubular and periglomerular fibrosis, hypercellular glomeruli with occluded Bowman's space, and partial or complete adhesion to Bowman's capsule were constant features. Electron microscopy revealed thickened glomerular basement membranes with spikes accompanied by finely granular electron-dense deposits at the epithelial side and dense material in the mesangial matrix. Indirect immunofluorescence indicated linear immunoglobulin deposits along the glomerular basement membrane. The presence of R. salmoninarum was demonstrated by culture and by indirect immunofluorescence. Low serum hemagglutination-inhibiting antibody titers were demonstrated.
Intracranial Meningioma with Pulmonary Metastasis in Three Dogs
Authors: Schulman F. Y. , Ribas J. L. , Carpenter J. L. , Sisson A. F. , LeCouteur R. A.
Published: March 2010

Extracranial metastasis of primary central nervous system neoplasms is uncommon and has not been described in the dog. We report the clincopathologic features of intracranial meningioma with pulmonary metastasis in three dogs (case No. 1: 13-year-old castrated male Boxer dog; case No. 2: 14-year-old spayed female Dachshund; case No. 3: 6-year-old spayed female German Shepherd Dog). Case No. 1 presented with ataxia, lethargy, vomiting, and leaning and falling to the right, and had a transient remission following radiation and corticosteroid therapy; case No. 2 had a history of seizures that were unresponsive to primidone, left-sided postural reaction deficits, ataxia, and circling to the right; case No. 3 had only intermittent episodes of vomiting. Computed tomography of case Nos. 1 and 2 revealed peripherally located homogeneous contrast-enhancing intracranial masses. Postmortem examination revealed intracranial masses with single or multiple pulmonary nodules in all three cases. Histologically, the intracranial and pulmonary masses were meningotheliomatous meningiomas with atypical features including brain infiltration, necrosis, nuclear atypia, prominent nucleoli, and moderate cell density. All of the primary meningiomas had low mitotic rates. The current interest in early diagnosis and aggressive clinical/surgical management of canine patients with meningioma and other primary central nervous system neoplasms will likely result in an increased detection of extracranial metastases.
Ultrastructural Findings in Congenital Anemia, Dyskeratosis, and Progressive Alopecia in Polled Hereford Calves
Authors: Steffen D. J. , Leipold H. W. , Elliott G. S. , Smith J. E.
Published: March 2010

Ultrastructural evidence of dyserythropoiesis was found in ten calves (ages 1 to 16 months) previously diagnosed as having congenital anemia, dyskeratosis, and progressive alopecia. Morphologic abnormalities found in erythroid precursors of all calves were associated with the nucleus. Rubriblast nuclei were irregular with numerous blebs, indentations, and deep clefts. Elongated blebs appeared as satellite nuclei in some sections. Nuclear membranes had numerous defects or gaps, which were frequently present in, but not limited to, recently divided cells. Cytoplasmic material could be found within these gaps and extending into the nucleus. Rubricytes had chromatin that was abnormally condensed and hyperosmiophilic, with numerous translucent vacuoles present. Binucleate rubricytes occurred frequently in affected calves. These changes resemble those of type I congenital dyserythropoiesis in human beings, and we suggest congenital anemia, dyskeratosis, and progressive alopecia of Polled Hereford calves as the appropriate diagnostic terms to describe this disease.
Vascular Lesions in Lungs of Bali Cattle with Jembrana Disease
Authors: Budiarso I. T. , Rikihisa Y.
Published: March 2010

Jembrana disease is an acute infectious disease of unknown etiology enzootic among Bali cattle ( Bos javanicus) in Indonesia. Morphologic examination of 75 female Bali cattle between 18 months and 4 years old affected with Jembrana disease consistently revealed pulmonary granulomatous vascular lesions. The lesions were diffusely distributed throughout the lung. The principal lesion was the presence of a large number of intravascular macrophages that filled the lumina of pulmonary veins and pulmonary arteries of a vascular diameter of 20–200 μm, excluding the rest of blood cellular components. Concentric layers of perithelia] cells also with plasma cells and macrophages were occasionally present around both veins and arteries. Infiltration of polymorphonuclear leukocytes or small lymphocytes was not seen. Destruction or necrosis of tissues or blood vessels was rarely seen. Because this vascular lesion was found in the lungs of all affected cattle examined, this change is useful for the postmortem diagnosis of Jembrana disease. Moreover, its presence could be used to distinguish Jembrana disease from malignant catarrhal fever and other lymphoreticular proliferative conditions that are frequently found among cattle in Indonesia.
Effects of Mithramycin on Calcium Metabolism and Bone in Dogs
Authors: Rosol T. J. , Chew D. J. , Couto C. G. , Ayl R. D. , Nagode L. A. , Capen C. C.
Published: March 2010

Mithramycin (0.1 mg/kg) was administered intravenously to eight Beagle dogs on days 0 and 7 to determine its effects on calcium and phosphorus metabolism, serum parathyroid hormone concentration, osteoclastic bone resorption, and serum biochemical and hematologic parameters. Ionized calcium concentration was paradoxically increased on day 1 and decreased on day 8 in association with an increased serum parathyroid hormone concentration. Serum phosphorus concentration was decreased on days 1 and 2. Osteoclastic bone resorption in iliac cancellous bone was significantly decreased on day 8. There were mild increases in serum alkaline phosphatase (days 1, 2, 4, 8, 9), aspartate aminotransferase (day 9), and gammaglutamyl transpeptidase (days 7, 9) activities. Platelet numbers were increased on days 7 through 13, and packed red blood cell volumes were mildly decreased. This investigation demonstrates that two doses of mithramycin can be administered safely to dogs and may inhibit bone resorption in diseases associated with increased osteoclastic bone resorption, such as humoral hypercalcemia of malignancy.
Age-related Changes in Thyroid Structure and Function in Sprague-Dawley Rats
Authors: Rao-Rupanagudi S. , Heywood R. , Gopinath C.
Published: March 2010

Investigation of thyroid glands from 500 male and 500 female Sprague-Dawley rats, at time points of 8, 17, 30, 56, and 108 weeks of toxicity studies conducted at the Huntingdon Research Centre between 1981 and 1984, revealed age-related structural and functional changes that have previously not been well documented. The number of ultimobranchial cysts decreased with age, while area(s) of C-cell hyperplasia appeared with age. Beginning at 56 weeks, some of the thyroid follicles were hyperdistended with colloid, had irregular lumens, and were lined by flattened epithelium. These follicles had clumped, granular, and stratified colloid. Follicular tumors were found in 8% of the males and 6% of the females at 108 weeks. There was an increase in absolute thyroid weights (males from 21.8 ± 4.0 g to 46.5 ± 19.05 g, females from 17.2 ± 4.53 g to 41.7 ± 26.92 g) and body weights (males from 382.0 ± 70.6 g to 806.0 ± 120.7 g, females from 220.0 ± 21.0 g to 495.0 ± 127.3 g) with age in both sexes, but the relative thyroid weights were not significantly affected. Negative allometry was observed. With an increase in the age of the rats, there was a decrease in the height of the follicular epithelium and an increase in the internal follicular diameter and the total number of follicles. No prediction for sex could be detected. Serum T3 and T4 concentrations were constant until 56 weeks of age, but at 108 weeks, the values were markedly reduced (in males, serum T3 concentration decreased from 91.60 ± 13.970 ng/100 ml to 32.90 ± 10.878 ng/100 ml, and in females, from 90.80 ± 11.338 ng/100 ml to 48.10 ± 8.875 ng/100 ml; in males, serum T4 concentration decreased from 5.94 ± 0.679 μg/100 ml to 3.04 ± 0.604 μg/100 ml, and in females, from 4.59 ± 0.717μg/100 ml to 2.77 ± 0.786 μg/100 ml). The data suggest that the thyroid function of Sprague-Dawley rats reduces as the rats age.
Correlation of DNA Ploidy to Tumor Histologic Grade, Clinical Variables, and Survival in Dogs with Mast Cell Tumors
Authors: Ayl R. D. , Couto C. G. , Hammer A. S. , Weisbrode S. , Ericson J. G. , Mathes L.
Published: March 2010

By using flow cytometry, a retrospective analysis of the DNA content of 40 primary canine mast cell tumors and seven lymph nodes that contained metastatic mast cell tumor from 44 dogs of various breed, sex, and age was performed on formalin-fixed, paraffin-embedded samples of the tumors and nodes. These samples were chosen according to the following criteria: samples contained sufficient well-preserved tumor tissue in the paraffin block for processing, sufficient patient history data were available, clean and homogeneous cell suspensions were obtained after processing, and interpretable DNA histograms were produced on analysis. The ploidy data obtained were compared with the histopathologic grade, the anatomical site of occurrence, the clinical stage of the tumors, and the survival of the dogs. Over 70% (29/40) of the mast cell tumors were diploid. Three metastatic mast cell tumors in lymph nodes had the same ploidy status as their corresponding primary tumors. In five dogs, mast cell tumors from multiple sites in each dog displayed similar ploidy status. Of 26 dogs evaluated for survival times, 69% (18/26) had diploid tumors and 31 % (8/26) had aneuploid tumors. When numbers of diploid versus aneuploid tumors were compared, no significant difference was found between any two grades, clinical stages, or anatomic sites. A significant difference ( P = 0.02) was found, however, between aneuploid and diploid tumors when comparing Stage I and non-Stage I disease. The Kaplan-Meier survival plot indicated a tendency towards an increased survival within the first year in dogs with diploid versus aneuploid tumors ( P = 0.06).
Characterization of Morphologic Changes and Lymphocyte Subset Distribution in Lymph Nodes from Cats with Naturally Acquired Feline Immunodeficiency Virus Infection
Authors: Rideout B. A. , Lowernstine L. J. , Hutson C. A. , Moore P. F. , Pedersen N. C.
Published: March 2010

Lymph nodes were collected at biopsy or necropsy from 18 cats with naturally acquired symptomatic feline immunodeficiency virus (FIV) infection and from 18 seronegative cats. Thirty-five of the cats were domestic shorthairs and one was a Persian cross. The cats ranged from 7 months to 16 years of age and were mainly obtained from California veterinary practitioners, a California cattery, and a Veterinary Teaching Hospital. Based on clinical signs present at tissue collection, ten FIV-infected cats fell into the acquired immunodeficiency syndrome (AIDS)-related complex (ARC) clinical stage and eight in the terminal (AIDS) stage of FIV disease. All cats were FeLV negative by antigen ELISA. Histologic sections of lymph nodes from each cat were examined blindly and were categorized as hyperplastic, involuting, mixed hyperplastic and involuting, depleted, or normal based upon subjective evaluation of follicles and paracortex. The relative abundance of plasma cells was evaluated in methyl green pyronin (MGP) and hematoxylin and eosin-stained sections. Similar numbers of FIV-seropositive and -seronegative cats fell into each lymph node category. The only difference evident between FIV-infected cats and control cats was in the degree of plasmacytosis present; moderate to marked plasmacytosis was present in 13/18 FIV-infected cats but in only 3/18 control cats. Immunohistochemical staining of frozen lymph node sections from six FIV-infected cats and 12 control cats for CD4, CD8, Factor VIII-related antigen, and a B cell/follicular dendritic cell-specific (CD21-like) antigen revealed only a slight increase in the relative proportion of paracortical CD8+ lymphocytes versus CD4+ lymphocytes in lymph nodes from FIV-infected cats. These findings suggest that lymph node changes previously considered to be specific or highly suggestive of lentivirus-induced immunodeficiency disease are actually not specific but occur in FIV-seronegative cats as well. Despite this lack of specificity, lymph node changes seen in FIV-infected cats may have prognostic significance. All cats in the ARC stage had hyperplastic or mixed hyperplastic and involuting nodes, whereas those in the AIDS stage had either involuting or depleted nodes, which suggests that the clinical stage of disease correlates with the category of lymph node change.
Role ofHelicobacter felisin Chronic Canine Gastritis
Authors: Lee A. , Krakowka S. , Fox J. G. , Otto G. , Eaton K. A. , Murphy J. C.
Published: March 2010

Five gnotobiotic Beagle dogs were orally inoculated with a pure culture of Helicobacter felis. The remaining two littermates served as contact controls. Thirty days after infection, all animals were euthanatized and specimens were collected for evaluation. In infected dogs, H. felis was recovered from all areas of the stomach. Colonization was heaviest in the fundus and antrum. H. felis was not cultured from any segment of the gastrointestinal tract distal to the duodenum. Two weeks after infection, all five infected dogs had detectable IgM and IgG serum antibody to H. felis, whereas control dogs had no measurable H. felis serum antibody throughout the study. Histopathologic changes in the stomachs of infected dogs included large numbers of lymphoid nodules throughout all regions of the gastric mucosa and were most numerous in the fundus and body. A mild, diffuse lymphocytic infiltrate with small numbers of plasma cells and eosinophils was also present in the subglandular region of all portions of the gastric mucosa. Electron microscopic examination revealed large numbers of spiral-shaped H. felis in gastric mucus adjacent to or superimposed over the areas of inflammation. Occasionally, however, H. felis was observed within the canaliculi of gastric parietal cells. Histopathologic changes in the stomachs of the contact control dogs were limited to focal infiltrates of eosinophils and small aggregates of lymphocytes in the subglandular portions of the gastric mucosa in one animal. Infection with H. felis is a likely cause of naturally occurring lymphofollicular gastritis.
Rift Valley Fever Virus-induced Encephalomyelitis and Hepatitis in Calves
Authors: Rippy M. K. , Topper M. J. , Mebus C. A. , Morrill J. C.
Published: March 2010

Three calves (Nos. 1, 2 = 7 days old; No. 3 = 21 days old) were inoculated subcutaneously with virulent Rift Valley fever (RVF) virus. All calves became viremic and clinically ill, but the two 7-day-old calves were moribund and were euthanatized subsequently on post-inoculation day (PID) 3. Highest viral titers were measured in the serum, with lesser concentrations in the brain, heart, spleen, and liver of these animals. Viral antigens were detected by immunohistochemical analysis only in the livers, where positive staining was localized in coalescing foci of hepatocellular necrosis. The 21-day-old calf appeared to recover after viremia and pyrexia but became lethargic and ataxic and was euthanatized on PID 9. The calf was no longer viremic, and RVF virus was isolated only from the brain. Microscopic examination of the central nervous system revealed diffuse perivascular infiltrates of lymphocytes and macrophages, multifocal meningitis, and focal areas of neuronal necrosis and aggregates of macrophages, lymphocytes, and neutrophils throughout all regions of the brain and cervical spinal cord. There was positive immunohistochemical staining for viral antigens within the cytoplasm of neurons and glial cells throughout the central nervous system. Thus, RVF virus can cause encephalomyelitis in calves, and the specific virologic diagnosis can be made by immunohistochemical localization of viral antigens in formalin-fixed tissues.
Flow Cytometric Analysis of Feline Reticulocytes
Authors: Reagan W. J. , Vap L. M. , Weiser M. G.
Published: March 2010

Hemolytic anemia was induced in five Domestic Shorthair cats (four adult males and one spayed female obtained from a breeding colony at Colorado State University, CO), and blood samples were analyzed from five other cats (two castrated male Domestic Shorthairs, one castrated male Domestic Longhair, one castrated male Persian, and one spayed female Siamese presented to the Veterinary Teaching Hospital at Colorado State University for miscellaneous problems). Blood samples taken from these cats had percentages of aggregate reticulocytes that ranged from 0% to 14.5% as determined by manual counting and were used to identify the best technique for staining cat reticulocytes for flow cytometric analysis. The best technique was mixing a blood sample (1/2,000 dilution) with 0.2 μg thiazole orange in 1 ml of diluent and incubating the mixture in the dark at room temperature for 30 to 60 minutes. The percentage of reticulocytes determined by flow cytometry correlated well ( r = 0.88) with manually determined aggregate reticulocyte percentages; no significant differences were observed between the two techniques ( P > 0.05). For the conditions used, punctate reticulocytes were not detected by flow cytometry. Samples with very high platelet numbers and very low packed cell volumes may show falsely elevated percentages of reticulocytes as determined by flow cytometry. The reproducibility of the flow cytometric technique was good; the coefficient of variation ranged from 4.8% to 17.9% in two samples with two different times of incubation. Staining of cat aggregate reticulocytes with thiazole orange and use of flow cytometric quantification is a reproducible technique that has a good correlation with the manual reticulocyte counting method.
Experimental Oral Administration of Canine Adenovirus (Type 2) to Raccoons (Procyon lotor)
Authors: Hamir A. N. , Raju N. , Rupprecht C. E.
Published: March 2010

Canine adenovirus type 2 (CAV2) has been proposed for recombinant vaccines to control rabies in wild animals. To evaluate the suitability of CAV2 as a safe vector for the genetically engineered vaccines, seven wild-caught raccoons (three males and four females) were administered CAV2 per os. Two of the animals were euthanatized on each of post-infection days 3, 6, and 14, and one was euthanatized on day 21. Two other control raccoons (a male and a female) were also euthanatized on day 21. Microscopic pulmonary lesions of multifocal necrotizing bronchiolitis with basophilic intranuclear inclusions were seen in 3/4 raccoons euthanatized on post-infection days 3 and 6. Ultrastructural examination of lungs with pulmonary lesions revealed hexagonal viral particles characteristic of adenoviruses. CAV2 is potentially pathogenic for raccoons, and this susceptibility should be of concern to developers of recombinant vaccines who intend to use CAV2 as a vaccine vector.
Histopathologic Lesions in Sea Otters Exposed to Crude Oil
Authors: Lipscomb T. P. , Harris R. K. , Moeller R. B. , Pletcher J. M. , Haebler R. J. , Ballachey B. E.
Published: March 2010

Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters ( Enhydra lutris) that appeared to be contaminated with oil, that were in danger of becoming contaminated, or that were behaving abnormally were captured and taken to rehabilitation centers. Exposure to oil was assessed by visual examination when otters arrived at the centers. Degree of oil exposure was graded according to the following criteria: oil covering greater than 60% of the body—heavily contaminated; oil covering 30–60% of the body—moderately contaminated; oil covering less than 30% of the body or light sheen on fur—lightly contaminated. If there was no oil visible, otters were considered uncontaminated. Tissues from 51 oil-contaminated sea otters (14 males, 37 females) and from six uncontaminated sea otters (three males, three females) that died in rehabilitation centers were examined histologically. Among oil-contaminated sea otters, 19/46 had interstitial pulmonary emphysema, 13/40 had gastric erosion and hemorrhage, 11/47 had centrilobular hepatic necrosis, 14/47 had periportal to diffuse hepatic lipidosis, and 10/42 had renal tubular lipidosis. Of the uncontaminated sea otters, 1/6 had gastric erosion and hemorrhage and 1/6 had diffuse hepatic lipidosis. Histologic examinations were performed on tissues from five sea otters (three males, two females) found dead with external oil present 15 to 16 days after the spill. Periportal hepatic lipidosis and renal tubular lipidosis were found in 3/5, and interstitial pulmonary emphysema was found in 1/5. Tissues from six apparently normal sea otters (four males, two females) collected from an area not affected by an oil spill were examined histologically, and none of these lesions were found. We conclude that interstitial pulmonary emphysema, centrilobular hepatic necrosis, and hepatic and renal lipidosis of sea otters were associated with exposure to crude oil. Gastric erosion and hemorrhage may have been associated with stress of captivity and/or oil exposure.
Two Types of Bacteria Adherent to Bovine Respiratory Tract Ciliated Epithelium
Authors: Hastie A. T. , Evans L. P. , Allen A. M.
Published: March 2010

Two hundred sixty tracheas were obtained from a Philadelphia abattoir under permit from the Department of Agriculture; the tracheas were excised from predominantly Holstein calves of both sexes that weighed approximately 250 kg. Tracheas were transported in normal saline to the laboratory at Thomas Jefferson University, Philadelphia, Pennsylvania. Evidence of bacteria adherent to the tracheal epithelium was found in specimens from 20/24 of these tracheas. The epithelium from each of five tracheas was placed in glutaraldehyde fixative for transmission electron microscopic examination. Epithelium from each of 12 other tracheas was placed in formaldehyde fixative for light microscopic examination. Microscopically, 13 of these 17 bovine tracheal epithelia were observed to contain bacteria located longitudinally parallel to and between cilia and microvilli of ciliated cells. Preparations of ciliary axonemes isolated from the epithelium of seven additional bovine tracheas also contained these bacteria in sections viewed by a transmission electron microscope. These bacteria had two different ultrastructural morphologies: filamentous with a trilaminar-structured cell wall and short with a thick, homogeneously stained cell wall beneath a regularly arrayed surface layer. The short bacillus had surface carbohydrates, including mannose, galactose, and N-acetylgalactosamine, identified by lectin binding. The filamentous bacillus was apparently externally deficient in these carbohydrates. Immunogold staining revealed that the filamentous bacillus was antigenically related to cilia-associated respiratory (CAR) bacillus, which has been identified in rabbit and rodent species. Significantly decreased numbers of cilia were obtained from tracheal epithelium heavily colonized by the filamentous bacilli, suggesting a pathologic change in ciliated cells.
Prognostic Factors in Canine Mammary Tumors: A Multivariate Study of 202 Consecutive Cases
Authors: Hellmén E. , Bergström R. , Holmberg L. , Spångberg I.-B. , Hansson K. , Lindgren A.
Published: March 2010

The prognostic variables of 223 consecutively sampled spontaneous mammary tumors from female dogs were studied. These variables included flow cytometric DNA analysis and cell proliferation measured as cells in S-phase rate evaluated from DNA histograms. The dogs were surgically treated, in most cases with unilateral mastectomy (all mammary glands), and 202 of the 223 dogs were studied temporally following surgery. Univariate analysis with correction for age indicated that the variables of lymph node metastasis, elevated S-phase rate, presence of a sarcoma, DNA aneuploidy, and ulceration and infiltrative growth into underlying tissue had a statistically significant negative influence on the survival rates of dogs with a diagnosed malignant tumor. Similar results were obtained from tests on all dogs, but tumor size and its relative hazard increased with increasing size of the tumors, regardless of whether total or disease-specific mortality was considered. Using multivariate-analysisconducted Cox's proportional hazards model, elevated S-phase rate, increased age, and presence of a sarcoma remained statistically significant risk factors. The prognostic value of DNA ploidy and lymph node status varied depending on choice of end point. The study of tumor growth pattern and tumor size provided no prognostic information in the multivariate analysis. Flow cytometric cell analysis, including S-phase rate and DNA ploidy, is of value in predicting the prognosis of canine mammary tumors and can be used as a new prognostic tool to improve the preoperative diagnostics of canine mammary tumors.
Spontaneous Diabetes Mellitus in Young Cattle: Histologic, Immunohistochemical, and Electron Microscopic Studies of the Islets of Langerhans
Authors: Taniyama H. , Shirakawa T. , Furuoka H. , Osame S. , Kitamura N. , Miyazawa K.
Published: March 2010

Pathomorphologic studies were carried out on three cases of bovine diabetes mellitus with clinical signs of polydipsia, polyuria, severe emaciation, glycosuria, persistent hyperglycemia, and decreased glucose tolerance. At necropsy, two animals had atrophy of the pancreas, whereas other visceral organs, including the endocrine organs, showed no significant changes. Microscopically, there was atrophy and reduced numbers of pancreatic islets accompanied by interlobular and interacinar fibrosis and compensatory enlargement of some remaining islets. Lymphocytes were observed commonly around and within atrophic islets and occasionally around and within enlarged islets. Vacuolar degeneration with occasional accumulation of glycogen granules was observed in the β-cells of these enlarged islets. Immunohistochemical studies of atrophic islets demonstrated complete loss of β-cells or only a few small β-cells. There also was a corresponding decrease in the number of cells that stained with anti-glucagon (α-cells) or anti-somatostatin (δ-cells) antibodies. The vacuolated cells in the enlarged islets stained strongly with anti-insulin antibody (β-cells). Ultrastructurally, the majority of cells in the atrophic islets had reduced cytoplasmic volume and few secretory granules, features consistent with α-cells. In contrast, enlarged islets that had prominent immunohistochemical staining for insulin (β-cells) consisted of β-cells with cytosolic edema, mitochondrial swelling, dilated smooth endoplasmic reticulum, and reduced numbers of or degranulated secretory granules. These pathomorphologic features found in cattle are similar to those found in juvenile-onset insulin-dependent diabetes mellitus in human beings and suggest autoimmune involvement in diabetes.
Epizootic Gastritis Associated with Gastric Spiral Bacilli in Cheetahs (Acinonyx jubatus)
Authors: Eaton K. A. , Radin M. J. , Kramer L. , Wack R. , Sherding R. , Krakowka S. , Fox J. G. , Morgan D. R.
Published: March 2010

An outbreak of vomiting in a group of captive cheetahs ( Acinonyx jubatus) was investigated, and histologic examination revealed chronic gastritis characterized by infiltration of lymphocytes and numerous plasma cells and epithelial erosions. Lymphoid follicles, globule leukocytes, scattered neutrophils, and (in one animal) abscessed gastric glands were inconsistent findings. In addition, necropsy of three cheetahs revealed gastric mucosal hyperplasia. Two kinds of bacteria were identified in the stomachs of infected cheetahs. Numerous long, tightly coiled motile Gastrospirillum-like organisms were seen in gastric mucus and in Warthin-Starry-stained sections of mucosa. These bacteria could not be cultured but were transmitted to conventional mice in homogenates of gastric mucosa from infected cheetahs. Ultrastructural examination revealed helical filaments on some of these bacteria. In addition, a smaller Helicobacter sp. was isolated. This organism could be cultured in vitro under microaerophilic conditions. One or both of these bacterial species was probably responsible for the gastritis in these cheetahs.
Superficial Necrolytic Dermatitis (Necrolytic Migratory Erythema) in Dogs
Authors: Gross T. L. , Song M. D. , Havel P. J. , Ihrke P. J.
Published: March 2010

Twenty-two dogs with superficial necrolytic dermatitis were evaluated prospectively, twenty-one of which had characteristic crusting lesions of the paw pads. Histologically, epidermal lesions included parakeratosis and laminar intracellular edema. The plasma amino acid concentrations of eight dogs were markedly depressed. Nine dogs had terminal diabetes mellitus. These clinical and morphologic findings were strikingly similar to those of necrolytic migratory erythema in human beings, the most common cause of which is hyperglucagonemia due to islet cell tumor of the pancreas. No pancreatic tumors were found in these dogs; plasma glucagon concentrations in the five dogs tested were normal. The serum alkaline phosphatase concentrations were elevated in all dogs. Severe vacuolar hepatopathy, suggesting metabolically or hormonally induced hepatic dysfunction, was found in 21 dogs at necropsy or by biopsy; one dog had ultrasonographic abnormalities of the liver. Histopathologically, severe vacuolar alteration resulted in parenchymal collapse and nodular regeneration, which grossly mimicked cirrhosis. Although the definitive metabolic stimulus was not discovered for the cutaneous and hepatic lesions, the similarity of the cutaneous and biochemical features of canine superficial necrolytic dermatitis to human necrolytic migratory erythema warrants further investigation into possible underlying pancreatic hormonal dysfunction.
Placental Pathology of the Pregnant Mouse Inoculated withBrucella abortusStrain 2308
Authors: Tobias L. , Cordes D. O. , Schurig G. G.
Published: March 2010

Fifty-five pregnant BALB/c mice received various doses of Brucella abortus virulent strain 2308 intraperitoneally on day 9 of gestation, and uteri and spleens were examined at 3, 5, 7, and 9 days post-inoculation to study the pathogenesis of infection. A dose of 105.7B. abortus organisms produced a severe, necrosuppurative placentitis. Bacteria multiplied preferentially within the placenta and were identified within the rough endoplasmic reticulum of trophoblast giant cells and within the visceral yolk sac endoderm. Abortions did not occur, but infarction of the labyrinth region of severely affected placentas occasionally resulted in fetal death. The severity of infection in the spleens of nonpregnant mice receiving the same challenge dose was not significantly different from that in the spleens of challenged pregnant mice. These results suggest that the sensitivity of the pregnant mouse to placental brucellosis is not due to a generalized immunosuppression but rather may involve a combination of local suppression of the immune response and a susceptible cell population suitable for Brucella colonization and replication. Experimental murine brucellosis resembles ruminant brucellosis and provides a model to study the intracellular replication of B. abortus in trophoblasts.
An Immunohistochemical Study on the Cytogenetic Origin of Pulmonary Multinucleate Giant Cells in Porcine Dermatosis Vegetans
Authors: Evensen O.
Published: March 2010

The origin of pulmonary multinucleate giant cells (MGC) in porcine dermatosis vegetans was studied in six Norwegian Landrace pigs ages 4 (male), 5 (female), 6 (female), 10 (female), and 12 (one male, one female) weeks, using an avidin biotin peroxidase and alkaline phosphatase complex immunohistochemical method on sections of formalin- and ethanol-fixed and frozen tissue specimens. Well-characterized, commercially available antisera/monoclonal antibodies to keratin, vimentin, lysozyme, a monocytic antigen, and a myelomonocytic antigen were used. The immunoreactivity to intermediate-sized filaments in MGC was negative for keratins and positive for vimentin. In addition, a positive reaction was found in alveolar macrophages, chondrocytes, fibrocytes, alveolar lymphocytes, and granulocytes in ethanol-fixed tissue. Marked masking was observed in formalin-fixed tissue. Antilysozyme antiserum gave a positive cytoplasmic reaction in alveolar macrophages and MGC, although the reaction was variable in ethanol-fixed tissue. In trypsinized formalin-fixed tissue, a moderate and more consistent cytoplasmic reaction was observed in alveolar macrophages and MGC. Two monoclonal antibodies that identify human cells of the MMS, EMB 11 and Mac 387, were negative for EMB 11 in ethanol-fixed and frozen sections, whereas Mac 387 showed a positive and specific cytoplasmic immunoreaction in alveolar macrophages and small MGC in ethanol- and formalin-fixed tissue. Pulmonary MGC in dermatosis vegetans are derived from mesenchymal cells, and substantial evidence is provided in support of a monocyte/macrophage origin based on a positive reaction for lysozyme and a myelomonocytic antigen. The importance of adequate fixatives for immunohistochemical demonstration of cell-specific markers is clearly shown.
Adenomatous Hyperplasia of Equine Allantoic Epithelium
Authors: Hong C. B. , Donahue J. M. , Giles R. C. , Petrites-Murphy M. B. , Poonacha K. B. , Tramontin R. R. , Tuttle P. A. , Swerczek T. W.
Published: March 2010

Adenomatous hyperplasia with or without cystic formation of allantoic epithelium was observed in 63/954 equine placentas examined from 1 February 1988 to 31 January 1990. In 61/63 placentas, the adenomatous hyperplasia was associated with other placental lesions: 49 with chronic or chronic-active placentitis, six with placental edema, three with fetal diarrhea, one with placentitis and fetal diarrhea, one with fetal diarrhea and placental edema, and one with hyperplasia of chorionic epithelium. When lesions were less severe, the hyperplastic lesions were not grossly visible, but when lesions were severe, nodular, tumorous, cystic masses were observed at or near the insertion site of umbilical blood vessels. Histologically, lesions classified as stage 1 were characterized by hypertrophy and hyperplasia of epithelial cells and formation of intraepithelial glands (lumina). Lesions classified as stage 2 were characterized by the presence of fibroadenomatous changes in the allantoic stroma. Lesions classified as stage 3 were characterized by the formation of the nodular masses, which were composed of glandular or cystic structures of various sizes lined by cuboidal or low to medium columnar epithelium. These glands or cysts were empty or contained amphophilic secretion, a mixture of neutrophils and secretion material, or neutrophils. The cause of adenomatous hyperplasia of the equine allantois is not certain; however, there is a close connection between chronic placental disorders and this hyperplastic lesion.
Histologic and Immunohistochemical Studies of Granular Cell Tumors in Seven Dogs, Three Cats, One Horse, and One Bird
Authors: Patnaik A. K.
Published: March 2010

In a retrospective study, granular cell tumors in six dogs (Nos. 1–6), three cats (Nos. 1–3), one horse (No. 1), and one cockatiel ( Nymphicus hollandicus) (No. 1) and a meningioma with a granular cell component in one dog (No. 7) were examined histologically and immunohistochemically. These tumors were identified by histologic examination of surgical biopsy specimens, except in the horse, in which the tumor was an incidental finding at necropsy. These diagnoses were initially made by more than one pathologist. Five of the six granular cell tumors in the dogs were in the oral cavity; one of these was in the maxillary gingiva of a 6-month-old puppy. The tumors in the cats were located in the tongue, vulva, and digit. The tumor in the horse was in the lung, and the tumor in the cockatiel was in the periocular tissue. Histologically, all granular cell tumors were characterized by oval to polygonal cells of various sizes. The cells had abundant, pale, eosinophilic cytoplasm with distinct intracytoplasmic granules, distinct cell margins, and mostly central nuclei. In the dogs, the gingival tumor had a large amount of collagen tissue, the tumor in the tongue had dilated blood vessels, and the maxillary tumor in the puppy was more cellular than the other tumors. The tumors in the cats were more anaplastic than the other tumors; one, located in the digit, was considered malignant. The granules in all of the tumors stained with periodic acid-Schiff and were diastase resistant. On staining with Luxol fast blue, the granules of all tumors stained different shades of pink, with the exception of the tumor in the tongue of a cat, which stained bluish green. Immunocytochemically, all tumors except the tumor in the cockatiel reacted against antibodies to vimentin. The granular cell tumor in the lung of the horse and the intracranial meningioma in a dog reacted to the antibody S-100 protein; the tumor in the horse reacted to neuron-specific enolase; tumors in two dogs (gingiva and skin) reacted to L-antitrypsin, and the maxillary tumor also reacted to lysozyme; the malignant tumor in the digit of a cat and the periocular tumor in the cockatiel reacted to muscle common actin and actin; the tumor in the cockatiel also reacted to desmin. Results of these immunocytochemical studies suggest that granular cell tumors, like tumors composed of rhabdoid cells, clear cells, and oncocytes, can have similar morphologic features but be of different cellular origins.
Acute Megakaryoblastic Leukemia in One Cat and Two Dogs
Authors: Colbatzky F. , Hermanns W.
Published: March 2010

The clinical, hematologic, and histologic features of acute megakaryoblastic leukemia are described for an 8-year-old female Domestic Shorthair cat, a 3-year-old female mixed-breed dog, and a 3-year-old male German Shepherd Dog. The neoplastic cells were characterized as belonging to the megakaryocytic lineage. The following techniques were used: electron microscopy; detection of antibodies against human von Willebrand factor (vWF) and human platelet glycoprotein GP IIIa using a modified avidin biotin peroxidase complex technique on formalin-fixed paraffin sections; and enzyme histochemical methods on plastic sections for alkaline phosphatase, acid phosphatase, myeloperoxidase, α-naphthyl acetate esterase, α-naphthyl butyrate esterase, naphthol AS acetate esterase, and naphthol AS-D chloroacetate esterase. In addition, benign megakaryocytic cells, platelets, and neoplastic cells were labeled with lectins that have partially been shown to bind to platelet glycoproteins of other species. In healthy cats and dogs, the megakaryocytes and platelets reacted with lectins PSA, LCA, PHA-L, and WGA. Megakaryocytes and platelets from healthy cats were also labeled by lectin PNA. The lectins PHA-L and WGA reacted with neoplastic cells from the cat and both dogs. Lectin PNA bound to neoplastic cells from the cat, and lectins PSA, LCA, and SBA bound to neoplastic cells from both dogs. For the retrospective examination of paraffin-embedded material, the detection of vWF and GP IIIa appears to be the most reliable method for the identification of megakaryocytic cells.
Granulated Round Cell Tumor of Cats
Authors: McEntee M. F. , Horton S. , Blue J. , Meuten D. J.
Published: March 2010

Morphologic and biologic features of five feline granulated round cell tumors were compared with those previously reported to be of globule leukocyte and large granular lymphocyte origin. The five cats ranged from 6 to 9 years of age and presented with nonspecific gastrointestinal signs. Four of the five cats were tested for feline leukemia virus and were negative by enzyme-linked immunosorbent assay. The neoplastic process involved the abdominal cavity in all cases, with a predilection for the distal small intestine and mesentery. The liver and peripheral and thoracic lymphoid tissues were also sporadically affected. Neoplastic round cells contained 0.5–1.5-μm eosinophilic cytoplasmic granules that were difficult to discern on casual observation with hematoxylin and eosin stain but were deep blue and easily visualized when stained with phosphotungstic acid-hematoxylin. In two cases, epithelium in the affected ileum and liver contained unusually large numbers of apparently normal globule leukocytes. Ultrastructurally, the tumor granules tended to cluster at one nuclear pole and were spindle to round in shape with variably dense contents. Some granules contained a dense “cap” at one end or internal crystalloid bars that distorted the granule membrane. The tumors reported herein are similar to all three of the previously reported feline granulated round cell tumors and probably have a common cellular origin.
Variation in Rotavirus Virulence: A Comparison of Pathogenesis in Calves between Two Rotaviruses of Different Virulence
Authors: Hall G. A. , Bridger J. C. , Parsons K. R. , Cook R.
Published: March 2010

Variation in virulence between two bovine rotaviruses was investigated using ten female and ten male 10-day-old gnotobiotic calves of five breeds or cross breeds that were inoculated with a virulent strain or a strain of low virulence. Similar numbers of infectious viral particles were detected in feces of calves inoculated with either virus, but diarrhea, xylose malabsorption, and reduction of villus height occurred only after inoculation with virulent virus. The mean percentage of the area of the villus epithelium per villus immunostained for rotavirus antigen was eight times greater in calves inoculated with virulent virus, and the mean percentage of villi on which immunostained enterocytes were detected was twice as large in calves inoculated with virulent virus than in calves inoculated with the virus of low virulence. Mean crypt death and mean crypt cell production rates were increased after inoculation with either virus. Virulence was associated with extensive spread of infection through the small intestine, preferential colonization of the proximal small intestine, and marked damage to enterocytes and villi. The virus of low virulence infected the proximal small intestine poorly, and although it infected more enterocytes in the mid and distal small intestine and replicated in them, causing cytopathic effects, it did not damage intestinal structure and affect function.
Pulmonary Lesions in Mice Inoculated withActinobacillus pleuropneumoniaeHemolysin and Lipopolysaccharide
Authors: Idris U. E. A. , Harmon B. G. , Udeze F. A. , Kadis S.
Published: March 2010

Non-Swiss albino (CF1) male mice were used as a model to study the effects of specific toxic components of Actinobacillus pleuropneumoniae on the respiratory system. Mice were divided into five groups often each and were inoculated by the intranasal route with whole-cell Actinobacillus pleuropneumoniae serotype 1, cell-free culture supernatant fluid (CFCSF) containing hemolysin protein, purified lipopolysaccharide (LPS), heat-treated CFCSF, or phosphate-buffered saline solution. Pulmonary lesions were evaluated at 6 and 12 hours after inoculation. Mice inoculated with whole cells, CFCSF, and LPS developed severe purulent bronchiolitis and alveolitis. Focal pulmonary necrosis was also observed in these three groups but was most consistent in the CFCSF-inoculated mice. Ultrastructurally, lungs from mice inoculated with whole cells, LPS, and CFCSF were characterized by severe degenerative changes in type I and type II pneumocytes. Alveolar spaces contained cellular debris and fibrin. Endothelial cells were swollen, and selected pulmonary capillaries were occluded with platelets and fibrin. Infiltrating neutrophils were often swollen, vacuolated, and degranulated. Although inoculation with relatively large numbers of A. pleuropneumoniae are required to kill mice, the mouse lung appears quite sensitive to the toxic components produced by these bacteria. The elaboration of these two toxic components by A. pleuropneumoniae may be responsible for the characteristic pulmonary inflammatory and necrotic lesions observed in infected swine.
Sequential Changes in the Development of the Pancreatic Lesion of Zinc Toxicosis in Sheep
Authors: Smith B. L. , Embling P. P.
Published: March 2010

Fgorty-two 10-month-old castrated male sheep were dosed with zinc oxide to study the pathogenesis of the pancreatic lesion. For 4 weeks, the sheep were dosed three times per week with 240 mg Zn (as ZnO)/kg body weight/dose, and seven groups of six sheep each were necropsied at 4, 7, 14, 21, 28, 56, and 112 days after the start of dosing. Plasma zinc concentrations rose rapidly to 2.0-2.5 μg Zn/ml over the dosing period and fell rapidly to less than 1 μg Zn/ml within 2 weeks after dosing ceased. Organ zinc levels in liver, kidney, and pancreas fell from concentrations above 800 μg Zn/g (dry matter basis) to less than 200 μg/g within 4 weeks after dosing ceased. Although no animals showed any clinical signs of zinc toxicity, many sheep dosed with zinc oxide developed pancreatic lesions. Pancreatic lesions took up to 4 weeks to develop fully. The early pancreatic lesions involved necrosis of the pancreatic duct epithelium, periductular inflammation, and interlobular fat necrosis, all evident at 7 days but not at 4 days. These early lesions were followed by edema, lobular cystic change, atrophy, fibrosis, and a ductular hyperplasia. The initial lesion of the pancreas was ductular injury, and the subsequent pancreatic lesions may have developed in those lobules whose excretory ducts were obstructed by inflammatory debris.