bluuebunny/crossref_metadata_2025 huggingface dataset:
A Morphologic and Immunocytochemical Study of Hepatic Neoplasms in Cats
Authors: Patnaik A. K.
Published: March 2010

A retrospective study was done of 47 neoplasms of the hepatic and biliary systems from 47 cats brought to The Animal Medical Center over a period of 10 years (1980 to 1989). Histologic examination of specimens taken at necropsy revealed that 87% (41/47) of the hepatic neoplasms were epithelial and 13% (6/47) were nonepithelial. Of the epithelial tumors, 25/47 (53%) were of intrahepatic bile duct origin, 9/47 (19%) were of hepatocellular origin, 5/47 (11%) involved the extrahepatic bile ducts, and 2/47 (4%) were adenocarcinomas of the gall bladder. Of the nonepithelial neoplasms, hemangiosarcomas were more common, 5/47 (11%), than leiomyosarcomas, 1/47 (2%). Multiple liver lobes were involved in 21/34 (62%) of the epithelial and all six of the nonepithelial intrahepatic neoplasms. Most of the bile duct adenocarcinomas (6/9) were predominantly characterized by acinar structures with mucin production, diffuse necrosis, and little desmoplasia. The hepatocellular carcinomas were characterized by three patterns—trabecular (five tumors), pseudoglandular pattern (two tumors), and anaplastic (one tumor). The hepatic carcinoid was characterized by various-sized groups of acinar and rosettelike structures, some with lumens, separated by thin fibrovascular stroma. The extrahepatic bile duct adenocarcinomas (4/4) were acinopapillary with moderate desmosplasia, whereas the adenocarcinomas of the gall bladder had elongated tubular structures lined by anaplastic cells and a severe desmoplastic reaction. The neuroendocrine carcinoma of the extrahepatic bile duct, the hemangiosarcomas, and the leiomyosarcoma had morphologic features characteristic of these neoplasms. Two of the 16 (13%) bile duct adenomas had anaplastic and precancerous changes. Residual benign components were seen in 10/15 (67%) of the biliary adenocarcinomas, 4/9 (44%) of the intrahepatic bile duct adenocarcinomas, and all of the extrahepatic bile duct adenocarcinomas and gall bladder adenocarcinomas. Results of immunohistochemical studies of the biliary neoplasms were similar to those described in studies of biliary neoplasms in human beings. Results of this study revealed that the frequency of different types of hepatic neoplasms in cats varied from that seen in dogs and human beings, but the morphologic features were comparable.
Early Sequential Ultrastructural Renal Alterations Induced by 2-Bromoethylamine Hydrobromide in the Swiss ICR Mouse
Authors: Wolf D. C. , Turek J. J. , Carlton W. W.
Published: March 2010

Thirty-two male Swiss ICR mice were injected intraperitoneally with 300 mg 2-bromoethylamine hydrobromide/kg body weight, anesthetized, and perfused with glutaraldehyde-paraformaldehyde solution at 5, 15, 30, 60, 90, 120, 150, and 180 minutes after treatment. Eight control mice were injected intraperitoneally with sterile diluent, and one was perfused at each of the same time periods as the treated mice. Proximal tubule epithelial alterations progressed over time from increased secondary lysosome and myeloid body formation to cellular and mitochondrial swelling and eventually cell necrosis. The glomerular, peritubular, and vasa recta capillaries had endothelial cell swelling and desquamation and platelet aggregation. Bromoethylamine nephrotoxicosis in the male Swiss ICR mouse is an ischemic necrosis of the proximal tubules and papilla initiated by endothelial cell damage and makes an excellent model of chemically induced damage to endothelial cells and tubular necrosis.
Hepatic Lesions in Rabbits Infected with Encephalitozoon cuniculi Administered per Rectum
Authors: Fuentealba I. C. , Mahoney N. T. , Shadduck J. A. , Harvill J. , Wicher V. , Wicher K.
Published: March 2010

Microsporidia have been recognized recently as opportunistic pathogens in acquired immunodeficiency syndrome patients. In an attempt to develop an animal model of enteric microsporidiosis, adult (5 to 6 months old) male Flemish Giant rabbits from a closed New York colony were administered 5 × 103, 5 × 105, and 5 × 107 Encephalitozoon cuniculi per rectum. Rabbits given 5 × 105 and 5 × 107 E. cuniculi had moderate granulomatous periportal infiltrates, characterized by the presence of numerous macrophages, epithelioid cells, and a few multinucleated giant cells, lymphocytes, and plasma cells. Inflammatory cells also were seen infiltrating the tunica adventitia and tunica media of hepatic portal veins and branches of the hepatic artery. This study demonstrates that administration of E. cuniculi per rectum to rabbits results in infection that is characterized by high frequency and severity of hepatic lesions.
Neuropathology of Chronic Wasting Disease of Mule Deer (Odocoileus hemionus) and Elk (Cervus elaphus nelsoni)
Authors: Williams E. S. , Young S.
Published: March 2010

The pathology of the central nervous system of nine mule deer ( Odocoileus hemionus) and six elk ( Cervus elaphus nelsoni) with chronic wasting disease, a spongiform encephalopathy of mule deer and elk, was studied by light microscopy. Lesions were similar in both species and were characterized by spongiform transformation of gray matter, intracytoplasmic vacuolation of neurons, neuronal degeneration and loss, astrocytic hypertrophy and hyperplasia, occurrence of amyloid plaques, and absence of significant inflammatory response. Distribution and severity of lesions were evaluated at 57 locations; there were only minor differences between deer and elk. Consistent, severe lesions occurred in olfactory tubercle and cortex, hypothalamus, and the parasympathetic vagal nucleus of deer, and sections examined from these regions would be sufficient to establish a diagnosis of chronic wasting disease. Lesions were milder in these locations in elk but were sufficiently apparent to be of diagnostic value. Other differences included increased severity of lesions in some thalamic nuclei in elk in contrast to deer, the occurrence of amyloid plaques demonstrable by hematoxylin and eosin and histochemical stains in deer in contrast to elk, and the presence of mild white matter lesions in elk but not in deer. Lesions of chronic wasting disease were qualitatively comparable to those of scrapie, bovine spongiform encephalopathy, transmissible mink encephalopathy, and the human spongiform encephalopathies. Topographic distribution and lesion severity of chronic wasting disease were most similar to those of scrapie and bovine spongiform encephalopathy. Duration of clinical disease did not significantly influence lesion distribution or severity in either species.
Pulmonary Arterial Changes in Feline Dirofilariasis
Authors: McCracken M. D. , Patton S.
Published: March 2010

Eleven cats with spontaneous dirofilariasis were necropsied; ten were domestic shorthairs and one was a Persian. The cats ranged in age from 1 to 10 years, and 6/11 cats were male. One to three heartworms were present in the right ventricle and pulmonary arteries of each of the 11 cats. Patchy areas of rugose thickening of the intima of the pulmonary trunk and marked villous endarteritis of lobar and medium-sized pulmonary arteries were observed. Affected larger vessels were partially occluded by large villous intimal proliferations that were lined by hyperplastic endothelial cells supported by connective tissue stroma. Moderate to marked infiltration of eosinophils and mononuclear inflammatory cells was consistently observed in the intima of affected larger pulmonary arteries. Thrombosis of pulmonary arteries was seen in five cats. Medial hypertrophy, mild intimal proliferative changes, and focal infiltrations of leukocytes were seen in small pulmonary arteries. Lesions indicative of right-sided heart failure consisting of right ventricular dilation and chronic passive congestion of the liver were observed in four cats.
Involvement of CD8+T Cells in Delayed-type Hypersensitivity Responses against Bovine Leukemia Virus (BLV) Induced in Sheep Vaccinated with Recombinant Vaccinia Virus Expressing BLV Envelope Glycoprotein
Authors: Okada K. , Ikeyama S. , Ohishi K. , Suzuki H. , Sugimoto M. , Numakunai S. , Chiba T. , Murakami K. , Davis W. C. , Ohshima K. , Ikawa Y.
Published: March 2010

Delayed-type hypersensitivity responses against bovine leukemia virus (BLV) envelope glycoprotein (gp60) were induced in the skin of sheep vaccinated with recombinant vaccinia virus (RVV) expressing BLV glycoprotein. The lesions were characterized by marked infiltration of lymphocytes, slight migration of neutrophils, eosinophils, and macrophages in the dermis to hypodermis, and partial intercellular edema in the reticular layer. Immunohistochemical analysis with monoclonal antibodies demonstrated that the lymphocytic infiltrates consisted mainly of CD8+T cells (53.7–55.8% at 48 hours post-challenge of BLV), CD4+T cells (24.7–26.7%), and B cells (11.5–16.9%). The role of CD4+and CD8+T cells in suppressing BLV growth in RVV-vaccinated animals is discussed.
Bovine β-mannosidosis: Pathologic and Genetic Findings in Salers Calves
Authors: Bryan L. , Schmutz S. , Hodges S. D. , Snyder F. F.
Published: March 2010

β-mannosidosis is a recently recognized lysosomal storage disease in newborn Salers calves. Fourteen calves with β-mannosidase deficiency were examined. Twelve calves were from routine laboratory submissions, and two calves were the result of a breeding trial. Salers calves with β-mannosidase deficiency were of normal gestational weight, 36 ± 6 kg, but were affected at birth. The head was moderately domed, and there was mild superior brachygnathism. The calves were recumbent and had a head tremor. There was bilateral renal enlargement, severe hypomyelination in the brain and variable thyroid gland enlargement. Severe cytoplasmic vacuolation was present within neurons, tubule epithelial cells, follicular cells and macrophages of the nervous, renal, thyroid and lymphoid tissues, respectively. Pedigree analysis and breeding trial results were consistent with an autosomal recessive disease. An initial biochemical survey of 1,494 Salers cattle indicated a carrier frequency of 23%.
Immunohistochemical Identification of Myoepithelial, Epithelial, and Connective Tissue Cells in Canine Mammary Tumors
Authors: Destexhe E. , Lespagnard L. , Degeyter M. , Heymann R. , Coignoul F.
Published: March 2010

Fifty-eight formalin-fixed paraffin-embedded canine mammary tumors, 19 malignant and 39 benign, were used in this study. Tumors were obtained from dogs submitted for surgical resection of lesions at private veterinary practices in Brussels or from the surgery unit of the Faculty of Veterinary Medicine, University of Liège. Immunohistochemical evaluation was performed, using monoclonal antibodies directed against keratins 8–18 and 19, vimentin, desmin, and α-actin and polyclonal antibodies directed against high-molecular-weight keratins and S-100 protein. The main cell types, epithelial, myoepithelial, and connective, were identified, and myoepithelial cells represented the major component of most tumors, both benign and malignant. Myoepithelial cells had five patterns: resting and proliferative suprabasal cells, spindle and star-shaped interstitial cells, and cartilage. Reactivity to keratin 19, vimentin, α-actin, and S-100 protein suggested a progressive transformation from resting cells to cartilage. Epithelial cell reactivities were limited to keratins; only keratinized cells were positive for polyclonal keratins. Myofibroblasts were positive for both vimentin and α-actin, and connective tissue cells were positive for vimentin. Myoepithelial cells appeared to be the major component of carcinomas, justifying reevaluation and simplification of histomorphologic classifications, with a “pleomorphic carcinoma” group including all carcinomas except squamous, mucinous, and comedo carcinomas. Immunohistochemical evaluation, in addition to routine hematoxylin and eosin histopathologic evaluation is recommended for precise classification of canine mammary tumors.
Immunohistochemical Reactivity of Basal and Luminal Epithelium-specific Cytokeratin Antibodies within Normal and Neoplastic Canine Mammary Glands
Authors: Griffey S. M. , Madewell B. R. , Dairkee S. H. , Hunt J. E. , Naydan D. K. , Higgins R. J.
Published: March 2010

Human basal epithelium (myoepithelium)-specific (312C8–1) and luminal epithelium-specific (13H5) cytokeratin antibodies were applied to frozen sections of normal canine mammary tissues (seven), benign adenomas and hyperplasias (five), mixed tumors (12), and adenocarcinomas (18) to determine if epithelial subsets could be discriminated by the use of an avidin biotin peroxidase complex immunohistochemical procedure. The 312C8–1 and 13H5 antibodies were consistently reactive with basal and luminal epithelium, respectively, in the normal mammary gland (7/7) and in benign adenomas and hyperplasias (5/5). Mixed mammary tumors had similar basal and luminal epithelial reactivity and also had proliferating spindle-shaped stromal cells that were reactive with 312C8–1 (10/12) and 13H5 (4/12). The adenocarcinomas were subclassified into basal, luminal, and basal/luminal on the basis of 312C8–1 reactivity (4/18), 13H5 reactivity (2/18), and dual reactivity with mutually exclusive anatomic distribution (11/18), respectively. Those tumors with dual immunoreactivity were indicative of noninvasive carcinomas. Dogs with neoplasms that were reactive with 312C8–1 and nonreactive with 13H5 had local recurrence or distant metastasis within 2 weeks to 6 months after diagnosis. Other antibodies used for comparison were pan cytokeratin AE1/AE3, actin HHF35, and vimentin. 312C8–1 and 13H5 antibodies are specific for canine mammary basal and luminal epithelium, respectively, and by employing these antibodies, the origin and differentiation of canine mammary neoplasms can be determined more accurately than on the basis of hematoxylin and eosin-stained tissue alone.
Production of a Monoclonal Antibody against Canine GMP-140 (P-Selectin) and Studies of Its Vascular Distribution in Canine Tissues
Authors: Doré M. , Hawkins H. K. , Entman M. L. , Smith C. W.
Published: March 2010

Rapid upregulation of the adhesion molecule GMP-140 (P-selectin) on endothelial cells is believed to play an important role in the initial binding of leukocytes to endothelium, a very early step in the inflammatory response. Activated platelets that are involved in the coagulation system and in inflammatory processes also express GMP-140 on their surfaces. The objectives of the present study were to develop a monoclonal antibody against this adhesion molecule in the dog and to use this antibody to study platelet–neutrophil interactions in whole blood and to characterize the in vivo localization of GMP-140 in canine tissues. Five Balb/c mice were immunized with thrombin-stimulated dog platelets, and clones were screened using an enzyme-linked immunosorbent assay. The clone MD3 (IgG1) showed preferential binding to activated as compared with resting platelets. Flow cytometric analysis using MD3 revealed that 27% of circulating neutrophils in unstimulated blood had platelets bound to their surfaces; stimulation with platelet activating factor increased this percentage to 85%. Immunoblot analysis of solubilized dog platelets resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that the antibody MD3 recognized an approximately 140-kd protein. Immunohistochemical study of normal dog tissues with MD3 revealed that the antigen was present in endothelial cells of arteries, capillaries, and veins, depending on the specific tissue examined. Blood vessels staining positively with MD3 were most abundant in the digestive system (liver, stomach, small and large intestines), moderate in the lungs, kidneys, spleen, lymph nodes, and endocrine glands, and minimal in the brain, myocardium, skeletal system, and skin. Based on its presence on stimulated but not resting platelets, its molecular weight, and its vascular distribution, the antigen recognized by MD3 appears to be the selectin GMP-140 of the dog. This study documents that the cellular and tissue distribution of GMP-140 in dogs is very similar to that in human beings.
Disseminated Malignant Histiocytosis in a Golden Retriever: Clinicopathologic, Ultrastructural, and Immunohistochemical Findings
Authors: Hayden D. W. , Waters D. J. , Burke B. A. , Manivel J. C.
Published: March 2010

Diagnosis of malignant histiocytosis (MH), a disorder characterized by systemic proliferation of morphologically atypical histiocytes and their precursors, in an 8-year-old neutered female Golden Retriever was based on light and electron microscopic and immunohistochemical findings. Clinically, the dog presented with unilateral forelimb lameness. Eight days after surgical exploration of a swollen brachium, the dog developed sudden onset of posterior paresis, fecal and urinary incontinence, and a flaccid tail. Necropsy revealed infiltrative and nodular lesions in the right forelimb and regional lymph nodes, thoracic and abdominal cavities, and lumbar epidural space. Gross lesions were not found in the lungs or integument. Histopathologic examination showed infiltrates of atypical histiocytes in skeletal muscle, joint, and regional lymph nodes of the right forelimb; intercostal muscle; lung; liver; spleen; pancreas; kidneys; and spinal dura. Most tumor infiltrates were nodular and composed of loosely aggregated cells that were 10-30 μm in diameter with abundant eosinophilic to foamy cytoplasm, had central or eccentric nuclei, and were periodic acid-Schiff negative. Many binucleated cells, multinucleated giant cells, and mitotic figures were seen. Tumor cells contained phagocytosed erythrocytes, mononuclear cells, and some leukocytes. Ultrastructural features of tumor cells included cytoplasmic lipid droplets, lysosomes, and phagolysosomes. Immunohistochemical studies on paraffin-embedded sections showed positive reactivity to human T-cell Ag (clone UCHL-1) and for lysozyme, α-1-antitrypsin, and cathespin B. Polyclonal intracellular immunoglobulin reactivity and lectin binding (peanut, soybean, and wheat germ agglutinins and concanavalin A) were also demonstrated. Criteria for diagnosis of malignant histiocytic tumors and differential diagnosis are discussed.
Avian Keratoacanthoma (Dermal Squamous Cell Carcinoma) in Broiler Chicken Carcasses
Authors: Hafner S. , Harmon B. G. , Stewart R. G. , Rowland G. N.
Published: March 2010

Multiple lesions of dermal squamous cell carcinoma are found at a low frequency (0.04%) in the carcasses of young meat-type chickens at slaughter. For this study, affected carcasses ( n = 308) were removed from the processing line, and lesions were characterized by size, distribution, and morphology. Carcasses were also sexed and examined for evidence of metastasis. Nodular ( n = 297) and ulcerative ( n = 1,707) lesions were counted and examined. Most lesions were present in the pectoral, dorsopelvic, and femoral feather tracts. Few lesions ( n = 11) were found in wing tracts. Mean diameter was 5.4 mm for ulcerative lesions and 3.1 mm for nodular lesions. Histologic sections of ulcerative ( n = 579) and nodular ( n = 113) lesions were examined. Small nodular lesions originated from hyperplastic feather follicle epithelium. Nodules contained keratin-filled cysts lined by squamous epithelium that were associated with isolated islands and infiltrating cords of dermal keratinocytes. Loss of surface epithelium resulted in noduloulcerative and ulcerative lesions. Invasion of underlying skeletal muscle and evidence of visceral metastasis were not present, but invasion through elastic laminae and into the subcutis was present in 20.5% (134/654) of the lesions examined. The nodular lesions in these carcasses were morphologically similar to early nodular lesions previously described in live chickens as avian keratoacanthomas. A retrospective study compared selected production parameters and disease condemnations to the prevalence of squamous cell carcinoma in 665 flocks of broiler chickens. There was a positive correlation ( P < 0.0001) with the occurrence of airsacculitis but a negative correlation with increased age and condemnations for leukosis ( P < 0.0001). Tumor frequency followed a pronounced seasonal pattern, with decreased prevalence in summer months.
Peanut Agglutinin Lectin Immunohistochemical Staining of Normal and Neoplastic Canine Tissues
Authors: Haines D. M.
Published: March 2010

Peanut lectin binding sites were demonstrated in normal canine tissues and in 114 canine tumors by avidin biotin complex immunohistochemical staining on unfixed cryostat tissue sections. Peanut agglutinin (PNA) receptors occurred in a variety of normal cells and tissues, including lymphoid follicle center cells; cortical thymocytes; basal cells and the stratum spinosum of stratified squamous epithelium; columnar epithelium of the gastrointestinal tract; parietal cells and chief cells of the stomach; some endothelial cells; myelin; chrondrocytes; spermatogenic cells; cells of the adrenal medulla; Bowman's capsule and the distal convoluted tubules of the kidney; prostatic, perianal and endometrial epithelium; and the extracellular matrix of connective tissues. Neoplastic cell staining was sporadic and was most often observed in benign or well-differentiated neoplastic tissues in which the corresponding normal cells also expressed PNA binding sites. However, PNA also bound to some tumor cells in which the analogous normal tissues were unstained, including cells of some fibrosarcomas, rhabdomyosarcomas, hemangiopericytomas and proliferating myoepithelial cells in mixed mammary tumors. Although PNA binding is complex and heterogeneous in canine tissues and does not appear to immunohistochemically detect a moiety associated with neoplastic transformation per se in the majority of canine tumors, the expression of PNA receptors may be associated with neoplastic changes in some mesenchymal cell populations.
The Expression of Keratins, Vimentin, Neurofilament Proteins, Smooth Muscle Actin, Neuron-specific Enolase, and Synaptophysin in Tumors of the Specific Glands in the Canine Anal Region
Authors: Vos J. H. , van den Ingh T. S. G. A. M. , Ramaekers F. C. S. , Molenbeek R. F. , de Neijs M. , van Mil F. N. , Ivanyi D.
Published: March 2010

Eight canine tumors originating from specific glandular structures in the anal region, as well as metastatic tumor tissue of two of these cases (case Nos. 7, 8), were immunohistochemically analyzed using various monoclonal antibodies (MoAbs) directed against human keratin types, vimentin, neurofilament proteins, and α-smooth muscle actin. These tumors also were stained for the broad-spectrum neuroendocrine markers neuron-specific enolase (NSE) and synaptophysin. In histologically normal canine anal structures, α-smooth muscle actin and NSE antibodies stained basally localized (probably myoepithelial) cells in the anal glands and the anal sac glands. NSE staining also was present in a limited number of luminal cells in both anal glands and anal sac glands. Synaptophysin labeling was not observed in any of these glandular structures. Histologically, the tumors were differentiated into well- and moderately differentiated perianal gland tumors ( n = 5) and carcinomas without perianal gland differentiation (n = 3), corresponding to the so-called apocrine carcinomas of the anal region. Immunohistochemically, the perianal gland tumors could be differentiated from the carcinomas by marked differences in staining pattern with the various keratin MoAbs, particularly MoAbs directed against human keratin types 7 and 18. The keratin-staining characteristics of the carcinomas suggest a glandular luminal cell origin. Metastases of the carcinomas showed loss of some keratin-staining characteristics as compared with the primary tumor. Staining for NSE was only observed in solitary cells and small cell clusters in the carcinomas and their metastases, whereas the α-smooth muscle actin antibody did not react with the carcinoma cells. None of the tumors stained for neurofilament proteins or synaptophysin. An unequivocal neuroendocrine nature of the carcinomas could not be substantiated by our immunohistochemical study, although the presence of a population of neuroendocrine cells within these neoplasms seems likely. Because the immunohistochemical features of the carcinomas with respect to various keratin MoAbs and NSE are similar to those of the anal glands and the anal sac glands, both these glands might be considered as site of origin of these carcinomas.
Trypanosoma congolense in the Microvasculature of the Pituitary Gland of Experimentally Infected Boran Cattle (Bos indicus)
Authors: Abebe G. , Shaw M. K. , Eley R. M.
Published: March 2010

The pituitary glands of seven Boran cattle ( Bos indicus), five infected with a clone of Trypanosoma congolense IL 1180 (ILNat 3.1) transmitted by Glossina morsitans centralis and two uninfected controls, were examined by light and electron microscopy 43 (experiment 2) or 56 (experiment 1) days after fly challenge. The three cattle used in the first experiment included a 15-month-old female (No. 1), a 24–month-old female (No. 2), and a 21–month-old male (No. 3) as a control. In the second experiment, four cattle were used: two females (Nos. 4, 5) and one male (No. 6), all between 15 and 24 months of age, and one female control (No. 7) of similar age. In all the infected animals, dilation of both the sinusoids and microvasculature was apparent, as was an increase in the thickness of the extracellular matrix between the pituitary lobules. Trypanosomes were found in the microvasculature of the adenohypophysis and neurohypophysis in all the infected animals. Focal degenerative changes were seen in the adenohypophyseal section of glands from the infected animals euthanatized 56 days post-infection. These degenerative structural changes were confined to the somatotrophs cells. The possible role that trypanosomes in the microvasculature may play in inducing pituitary damage and dysfunction is discussed.
Histopathologic Features and Post-surgical Sequelae of 57 Cutaneous Neoplasms in Ferrets (Mustela putorius furo.)
Authors: Parker G. A. , Picut C. A.
Published: March 2010

The study of the signalment, histomorphologic features, and post-surgical clinical progress of 57 cutaneous neoplasms in 55 domestic ferrets ( Mustela putorius furo L.) was based on diagnostic pathologic accessions (1987–1992) from 142 ferrets. Mean age of the group was 4.3 years; 31/54 (57%) were female and 23/54 (43%) were male. Thirty-three (58%) of the cutaneous neoplasms were basal cell tumors. The mean age of ferrets with basal cell tumor was 5.2 years, and 23/33 (70%) were female. Histologically, the basal cell tumors were composed of well-differentiated basaloid epithelial cells with various degrees of squamous and sebaceous differentiation, similar to those seen in basal cell neoplasms of dogs. Nine of the 57 (16%) cutaneous neoplasms were mastocytomas. The mean age of ferrets with mastocytoma was 4.1 years; four were male, four were female, and the sex of one was unrecorded. Histologically, the mastocytomas were composed of well-differentiated mast cells with few eosinophils, similar to cutaneous mastocytomas of domestic cats. The mast cells had a small number of metachromatic cytoplasmic granules, and in six of eight neoplasms the granules had an affinity for conjugated avidin-peroxidase. Six of the cutaneous neoplasms (11%) were fibromas. The mean age of ferrets with fibroma was 2.7 years; 5 (83%) were male. Two cutaneous hemangiomas (4%) were in females, which were 4 and 5 years of age. There was one each hemangiosarcoma, cutaneous polyp, anal gland adenocarcinoma, lymphosarcoma of the prepuce and inguinal lymph node, and adenocarcinoma of the prepuce.
Granulomatous Leptomeningitis in Beagle Dogs
Authors: Maeda H. , Ozaki K. , Horikiri K. , Narama I.
Published: March 2010

A granulomatous leptomeningitis was seen in seven laboratory Beagle dogs (four males, three females), 14 to 15 months old, that had been used as control or experimental subjects in a toxicologic study. The dogs were clinically normal during the experimental period. Microscopic lesions were characterized by typical noncaseating granulomas in leptomeninges and slight scattered perivascular cuffing in gray and white matter throughout the central nervous system, with no site of predilection. Although no microorganisms could be found by ordinary light microscopic examination, there was a positive reaction for Escherichia coli antigen in the cytoplasm of macrophages, which corresponded to periodic acid-Schiff-positive, calcium-negative, and iron-negative materials in the granulomas and cuffs. Electron microscopic examination revealed that these materials were large phagolysosomes indicative of abnormal lysosomal function. These findings indicate that at least some cases of canine granulomatous leptomeningitis could be very likely caused by E. coli and represent an entity distinct from classical canine granulomatous meningoencephalitis.
Histologic and Immunohistochemical Characterization of Hemangiomas in the Skin of Seven Young Horses
Authors: Johnson G. C. , Miller M. A. , Floss J. L. , Turk J. R.
Published: March 2010

The histologic and immunochemical characteristics of benign vascular tumors excised from the skin of seven young horses were evaluated. The patients were male horses of various breeds and were 16 months of age or younger at the time of presentation. Six tumors occurred on the extremities, and one was removed from the lip. Histologically, most tumors consisted of cellular nodules of varying compactness with few to many blood-filled lumina. Nodular growth separated preexisting adnexa and subcutaneous collagen. Some tumors contained or consisted predominantly of loosely packed arrays of ramifying arteries, veins, and capillaries separated by collagen within the dermis and subcutis. Within areas of nodular growth, multilayered vascular walls were encircled by reticulin strands that surrounded the endothelium and adjacent pericytes and also separated nonperivascular cells in the mass. Immunohistochemical staining of factor-VIII-related antigen and labeling by Ulex europeus-1 lectin was restricted to an innermost layer of cells surrounding vascular spaces, confirming their vascular endothelial origin. The plump fusiform cells arranged concentrically around the endothelium and some of those unassociated with vascular lumina stained with antibody to α-smooth muscle actin, as did the muscularis of larger vessels inside and outside of tumor nodules. These findings demonstrate an orderly arrangement between endothelium and supportive cells in these benign vascular neoplasms of young horses, similar to that observed during vascular development.
Cellular Hyperplasia in Rats Following Continuous Intravenous Infusion of Recombinant Human Epidermal Growth Factor
Authors: Breider M. A. , Bleavins M. R. , Reindel J. F. , Gough A. W. , de la Iglesia F. A.
Published: March 2010

In this study, we determined in vivo morphologic effects of continuous intravenous infusion of recombinant human epidermal growth factor (EGF) in adult Wistar rats. The EGF used consisted of the amino acid residues 1-48 of the human 53-amino-acid EGF molecule, purified from transfected Escherichia coli. Doses of 25, 100, or 250 μg/kg body weight were administered using Harvard digital syringe infusion pumps for 4 weeks. At necropsy, the submandibular salivary glands, Harderian glands, liver, kidneys (females only), and ovaries were enlarged and urinary bladders were thickened in 100- and 250-μg/kg rats. Numerous tissues of the 100- and 250-μg/kg rats contained hyperplastic epithelial cells, and selected organs also had mesenchymal cell proliferation. Epithelial proliferation was most pronounced in the trachea, nasal cavity, nasolacrimal duct, tongue, stomach, small intestine, large intestine, urinary tract, salivary gland ducts, and Harderian gland. Periportal hepatocytes were hypertrophic, correlating with increased liver weight. In addition, mesenchymal cell proliferation was evident in the gastric mucosa lamina propria and in heart valves in 100- and 250-μg/kg rats. Increased ovarian weight correlated with increased number and size of corpora lutea and an increased incidence of luteal cysts. Continuous systemic exposure of adult Wistar rats to high doses of EGF resulted in generalized epithelial hyperplasia and tissue-selective mesenchymal proliferation.
Canine Lymphoma: Immunocytochemical Analysis of Fine-needle Aspiration Biopsy
Authors: Caniatti M. , Roccabianca P. , Scanziani E. , Paltrinieri S. , Moore P. F.
Published: March 2010

Cytospin preparations of fine-needle aspirates from 21 dogs with peripheral lymphadenopathy (18 with lymphoma and three with lymph node hyperplasia) were studied by combining morphologic and immunocytochemical analysis. Fine-needle aspirates were taken from at least two enlarged lymph nodes, and the diagnosis was based on air-dried smears stained with May-Grünwald Giemsa. Fine-needle aspiration biopsy always provided an adequate quality and quantity of cells to perform morphologic and immunologic studies. Immunophenotyping was performed on cytospin preparations with a panel of eight monoclonal antibodies specific for canine cell surface antigens and one rabbit polyclonal antibody (A452) against human CD3, which cross-reacts with dog antigen. The immunocytochemical study resulted in the diagnosis of 14 B-cell lymphomas (CD21 +, CD3-) and three T-cell lymphomas (all CD3 +, two CD8+). One lymphoma lacked surface antigens specific for the B- or T-cell lineage and was classified as non-B-non-T lymphoma (CD21-, CD3-, CD4-, CD8-). The monoclonal antibodies CA12.10C12, CA4.1D3, and CA1D6 and the polyclonal antibody A452, used as a group, appeared to be the most useful reagents to suggest lymphoid origin and to discriminate between T- and B-cell phenotype. Cytospin preparations in combination with immunocytochemistry provided a practical, economical, and accurate method for the diagnosis and phenotyping of canine lymphoma.
A Morphometric Study of Bone Marrow Megakaryocytes in Foals Infected with Equine Infectious Anemia Virus
Authors: Wardrop K. J. , Baszler T. V. , Reilich E. , Crawford T. B.
Published: March 2010

Morphometric evaluation of bone marrow core biopsies was used to determine megakaryocyte (MK) numbers and MK size in nine foals with equine infectious anemia virus (EIAV)-induced thrombocytopenia. Both immunocompetent normal foals and foals with severe combined immunodeficiency (SCID) were used. Platelet counts were made three times weekly following viral infection. Bone marrow core biopsies were taken from the ilium of each foal prior to experimental infection, immediately after the onset of thrombocytopenia, and at necropsy. All foals developed thrombocytopenia by 23 days postinfection. The bone marrow MK density did not change in response to the thrombocytopenia. MK area did not change significantly; however, the MK nuclear area at necropsy was significantly higher than that preinfection. The presence of thrombocytopenia in the SCID foals showed that immune-specific responses were not required for the production of EIAV-induced thrombocytopenia. Furthermore, the lack of a compensatory megakaryocytopoiesis in both SCID and normal foals was consistent with the theory that altered platelet production plays a role in the development of this thrombocytopenia.
A Retrospective Study of Canine Senile Plaques and Cerebral Amyloid Angiopathy
Authors: Yoshino T. , Uchida K. , Tateyama S. , Yamaguchi R. , Nakayama H. , Goto N.
Published: March 2010

Epidemiologic and morphologic features of canine senile plaques (SPs) and cerebral amyloid angiopathy (CAA) were examined in 69 necropsied dogs. Dogs having only SPs (diffuse plaques) frequently suffered from malignant neoplasms, and their mean age was significantly lower than that of dogs with CAA only. Morphologically, diffuse plaques showed wide distribution compared with amyloid plaques or CAA and were predominantly concentrated in the frontal cortex. We were unable to find any significant relationship between the severity of the SPs and individual age. These findings may indicate that the occurrence of canine SPs is not strictly associated with aging only and that additional factors are related to the occurrence of SPs, especially diffuse plaques.
Immunohistochemical Characterization of Canine Transmissible Venereal Tumor
Authors: Mozos E. , Méndez A. , Gómez-Villamandos J. C. , Mulas J. Martín de las , Pérez J.
Published: March 2010

The collective immunohistochemical expression of human lysozyme, human alpha-1-antitrypsin, human CD3 antigen, calf vimentin, human keratins, human lambda light chains, canine immunoglobulins IgG, IgM, and bovine protein S-100 has been analyzed on formalin-fixed, paraffin-embedded tissue sections of 25 spontaneous canine transmissible venereal tumors (CTVT) from both genital and extragenital locations using the avidin-biotin-peroxidase complex technique. Lysozyme immunoreactivity was detected in 10/25 CTVT, alpha-1-antitrypsin in 14/25 CTVT, and vimentin in 25/25 CTVT. All CTVT cells were negative to keratins 5 + 8 of the Moll catalogue (RCK-102), S-100 protein, lambda light-chain immunoglobulins, IgG, IgM, and CD3 antigen. The intratumoral T- and B-lymphocyte infiltrate was differentiated using CD3 antigen, lambda light-chain immunoglobulins, IgG, and IgM, and this technique could be useful to evaluate the regressive or progressive growth stage of venereal tumors. Our findings support the hypothesis of a histiocytic immunophenotype for CTVT, and these staining techniques could be used in the differential diagnosis with lymphomas.
Alimentary and Respiratory Tract Lesions in Eight Medically Fragile Holstein Cattle with Bovine Leukocyte Adhesion Deficiency (BLAD)
Authors: Ackermann M. R. , Kehrli M. E. , Laufer J. A. , Nusz L. T.
Published: March 2010

Lesions in the alimentary tract were studied in eight medically fragile Holstein cattle homozygous for the bovine leukocyte adhesion deficiency (BLAD) allele as determined by polymerase chain reaction and restriction endonuclease analysis. These cattle received institutional medical care but died or were euthanatized because of chronic debilitation associated with diarrhea (6/8) and pneumonia (4/8). The six cattle with diarrhea had acute ( n = 3) or chronic ( n = 3) intestinal ulcers, but the other two remained relatively healthy for 3 years and did not develop intestinal tract ulcers. Ulcerated areas were present in the small intestine in six animals, and two of these also had ulcers in the large intestine. Ulcers were covered by thick exudates that, in chronic lesions, partially occluded the intestinal lumen. Intramural and serosal fibrosis also contributed to lumen constriction. Pseudomonas aeruginosa was isolated from the intestine of four cattle. Bovine viral disease virus and Salmonella were not isolated from the five cattle that were tested. Respiratory tract lesions consisted of dense infiltrates of neutrophils in bronchi, bronchioles, and alveoli. This study suggests that intestinal lesions are integral to the demise of BLAD cattle that receive intensive medical care and that neutrophils do infiltrate the lung and enter airway lumina, despite the adhesion deficiency.
Lesions of Neonatally Induced Toxoplasmosis in Cats
Authors: Dubey J. P. , Mattix M. E. , Lipscomb T. P.
Published: March 2010

Five pregnant queens were inoculated orally with Toxoplasma gondii tissue cysts. Twenty-two live and three dead kittens were born 16 to 31 days after inoculation. Four kittens were eaten by queens and, thus, were not available for histologic examination. Twenty-one kittens that died or were euthanatized on day 2 (two kittens), 4 (one kitten), 5 (five kittens), 6 (five kittens), 7 (one kitten), 8 (four kittens), 16 (two kittens), and 29 (one kitten) after birth were studied histologically. T. gondii was detected by bioassay and was seen in histologic sections of tissues from all 21 kittens. The histologic lesions associated with neonatal toxoplasmosis were widely disseminated infiltrates of macrophages and neutrophils often accompanied by necrosis; lymphocytes and plasma cells were occasionally present. The most consistent lesions were proliferative interstitial pneumonia (21/21); necrotizing hepatitis (20/21); myocarditis (21/21); skeletal myositis (21/21); glossal myositis (19/19); nonsuppurative encephalitis affecting the cerebrum (18/18), brain stem (15/15), and spinal cord (9/9); uveitis (19/19); necrotizing adrenal adenitis (18/18); and interstitial nephritis (16/21). Placental lesions (2/2) consisted of grossly visible areas of necrosis and mineralization.
Lesions of Acute Inhaled Lethal Ricin Intoxication in Rhesus Monkeys
Authors: Wilhelmsen C. L. , Pitt M. L. M.
Published: March 2010

Five unimmunized adult rhesus monkeys weighing 5.9-6.3 kg were challenged with a precalculated, inhaled dose of 20.95-41.8 μg/kg of aerosolized ricin. Two males and three females either died or were killed at the onset of respiratory distress between 36 and 48 hours post-ricin inhalation and were necropsied. Consistent gross and microscopic lesions were confined to the thoracic cavity. All monkeys had multifocal to coalescing fibrinopurulent pneumonia, diffuse necrosis, and acute inflammation of airways, and nearly diffuse alveolar flooding, with peribronchovascular edema. All monkeys also had purulent tracheitis, fibrinopurulent pleuritis, and purulent mediastinal lymphadenitis. One male monkey and one female monkey had bilateral adrenocortical necrosis. We attributed the cause of death to asphyxiation following massive pulmonary alveolar flooding. The lesions of acute inhaled ricin intoxication in rhesus monkeys closely resembled those lesions reported in rats with acute inhaled ricin intoxication.
Immunohistochemical Detection of Lymphocyte Subpopulations in the Tarsal Joints of Chickens with Experimental Viral Arthritis
Authors: Pertile T. L. , Walser M. M. , Sharma J. M. , Shivers J. L.
Published: March 2010

We characterized the lymphocytes in the tarsal joint synovium of chickens inoculated with an arthrotropic strain of avian reovirus. Cryostat sections of whole joints taken from 2 days to 35 days postinoculation were analyzed using monoclonal antibodies directed against B lymphocytes, T lymphocytes, and chicken Ia antigen. Plasma cells were morphologically identified using stained sections of whole joints. Time-dependent changes were found in the type and number of positively staining cells. Synoviocytes and cells with a dendritic morphology stained positive for Ia in normal joint sections. T cells, mostly CD8 positive, were present in low numbers in acute phase arthritis (2-6 days postinfection) in the perivascular and superficial regions of the synovium. Subacute arthritis (8-14 days postinfection) was characterized by increased numbers of CD4 and CD8 T cells in the perivascular and superficial regions. The perivascular T cells began to organize into aggregates, with IgM-positive B cells and plasma cells on the periphery of these aggregates. Some CD8-positive cells were detected on the surface of the articular cartilage. Cells staining positively for Ia were not lymphocytes. Chronic arthritis (> 14 days postinfection) was characterized by large numbers of T cells in the perivascular and superficial regions, with the CD4-positive T cells found primarly in the lymphoid aggregates of the perivascular regions. IgM-positive B cells were fewer, but more plasma cells, few of which stained positive for IgM, were present. Lymphocytes in chronic arthritis stained positively for Ia. These data suggest that the types, numbers, and activation level of lymphocytes present in the tarsal joints are similar but not identical to those seen in rheumatoid arthritis.
Distribution of Virus and Viral Antigen in Specific Pathogen-free Calves Following Inoculation with Noncytopathic Bovine Viral Diarrhea Virus
Authors: Marshall D. J. , Moxley R. A. , Kelling C. L.
Published: March 2010

Gross and microscopic lesions and distribution of virus were studied in specific pathogen-free calves (SPF) 10 days post-inoculation (PI) with bovine viral diarrhea virus (BVDV). To investigate possible differences in tissue tropism between BVDV isolates, two clinically and antigenically different noncytopathic (ncp) isolates of BVDV were compared in the study. Four calves were exposed to noncytopathic (ncp) BVDV 7937, and four to ncp-BVDV 126. Two additional calves that were not exposed to virus served as controls. Both ncp-BVDV 7937 and ncp-BVDV 126 induced mild disease characterized by variable fever and anorexia. Lymphoid depletion was evident in Peyer's patch of four calves and the thymus of two calves exposed to BVDV. Differences between these isolates in the distribution of BVDV or BVDV antigen in tissues of inoculated calves were not found. High concentrations of BVDV and BVDV-specific antigen were detected in the thymus, Peyer's patch, and mesenteric lymph node of all exposed calves. BVDV was shown to infect cells of the bone marrow without causing microscopic lesions. High concentrations of BVDV were recovered from the bone marrow of all calves exposed to BVDV and BVDV-specific antigen was demonstrated at this location in six of these calves. Platelet counts of calves exposed to BVDV were significantly reduced during infection, which resulted in thrombocytopenia in one calf. Focal areas of necrosis were observed in squamous epithelial cells of the tonsil and ruminai mucosa. BVDV-specific antigen was found in and adjacent to these foci. Calves exposed to ncp-BVDV 7937 had slightly more severe clinical signs than those exposed to ncp-BVDV 126.
Immunohistochemical Detection of Virulence-associated Antigens of Rhodococcus equi in Pulmonary Lesions of Foals
Authors: Madarame H. , Takai S. , Morisawa N. , Fujii M. , Hidaka D. , Tsubaki S. , Hasegawa Y.
Published: March 2010

Rhodococcus equi was isolated from the lungs of six foals with bronchopneumonia. All isolates expressed 15-17-kd antigens by immunoblot analysis and contained a virulence-associated plasmid of 85 or 90 kb. Immunohistochemically, R. equi from all pulmonary lesions showed the expression of 15-17-kd antigens mainly in the phagocytic cells. The specific monoclonal antibody to 15-17-kd antigens of R. equi (MAb 10G5) may be an aid in the diagnosis of R. equi-induced pneumonia.
Conjunctival Mycobacteriosis in Two Emus (Dromaius novaehollandiae)
Authors: Pocknell A. M. , Miller B. J. , Neufeld J. L. , Grahn B. H.
Published: March 2010

Avian tuberculosis was diagnosed in two young adult female commercial emus ( Dromaius novaehollandiae) with granulomatous conjunctivitis. Histologically, the granulomas appeared typical of avian tuberculosis. Caseonecrotic cores were surrounded by a broad ring of palisading epithelioid macrophages and multinucleate giant cells with a moderate admixture of heterophils, lymphocytes, and plasma cells. One conjunctival granuloma had multifocal mineralization. At necropsy, granulomas were also found in visceral organs of both birds. Acid-fast bacilli were demonstrated in all lesions using Ziehl-Neelsen or Fite's stains. Culture confirmed the bacilli to be Mycobacterium avium (complex).
Lymphangiosarcoma in a Young Dog
Authors: Sagartz J. E. , Lairmore M. D. , Haines D. , Sheafor S. E. , Couto C. G.
Published: March 2010

Lymphangiosarcoma was diagnosed from biopsy material obtained from an 8-week-old puppy with a progressively enlarging subcutaneous inguinal swelling. Histologically, the tumor was composed of endothelial cells immediately adjacent to large collagen bundles. Tumor cells formed irregular vascular channels which extended along the connective tissue investments of small vessels and nerves of the subcutis and deep dermis. Similar neoplastic tissue extensively infiltrated an inguinal lymph node. Neoplastic cells were immunohistochemically stained for factor 8-related antigen and were weakly positive when compared with several hemangiomas and hemangiosarcomas. Transmission electron microscopy revealed numerous micropinocytotic vesicles and a continuous basal lamina. The puppy was euthanatized at 8 months of age due to severe septic polyarthritis. Lymphangiosarcoma was documented at the site of the original tumor as well as in the axillary lymph node at necropsy.