bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure of Macrophages and Karyolytic Bodies in Small Intestinal Villi of Macaque Monkeys and Baboons
Authors: Bronson R. T.
Published: March 2010

Macrophages in the lamina propria at the tips of small intestinal villi in 41 of 51 macaque monkeys were filled with eosinophilic, autofluorescent, periodic acid-Schiff-positive globules, hematoxyphilic and Feulgen-positive granules, vacuoles, and iron and lipochrome pigments. The Feulgen-positive granules were seen ultrastructurally in macrophages of nine of 15 clinically normal macaques and baboons. Four of the 15 had similar granules in the intercellular spaces of the epithelium. Ultrastructurally, the eosinophilic globules were electrondense phagolysosomes; the Feulgen-positive granules resembled nuclei of lymphocytes in various stages of pyknosis. Cytoplasmic organelles enclosed in membrane-bound vacuoles were present in the intercellular spaces of the epithelium of one monkey. Similar organelles were phagocytized by macrophages in another monkey. Feulgen-positive granules have been reported in villi of normal rodents. In all other species, including man, degenerating nuclei called “karyolytic bodies” and other evidence of enterocyte or lymphocyte degeneration have been considered abnormal concomitants of irradiation and antimitotic therapy. The significance of the findings in monkeys is not known, but they may represent a subclinical disease process.
Pathology of Experimental CV777 Coronavirus Enteritis in Piglets. II. Electron Microscopic Study
Authors: Ducatelle R. , Coussement W. , Debouck P. , Hoorens J.
Published: March 2010

Sixteen cesarean-derived, colostrum-deprived piglets were infected oronasally with CV777 coronavirus on the second or third day of life. Two uninfected piglets were controls. After an incubation period of 22 hours to 36 hours, all principals showed severe diarrhea. The piglets were killed at different time intervals. Viral particles were found in the jejunal villous epithelial cells from 18 hours after infection until four days after the beginning of diarrhea. In the colonic epithelial cells, viral particles and degenerative lesions were found only in the piglet killed 36 hours after onset of diarrhea.

Degenerative lesions in the enterocytes began at 18 hours after infection and were most pronounced in the jejunum at the onset of clinical signs. From 24 hours on after the onset of clinical signs, three cell types were found: degenerated virus-containing enterocytes; cuboidal cells; and columnar, highly vacuolated cells containing lipid droplets.
Naturally Occurring Polypoid Hyperplasia and Papilloma in Gallbladders of the Fat Sand Rat (Psammomys obesus terraesanctae Thomas)
Authors: Ungar H. , Adler J. H.
Published: March 2010

The gallbladders of 256 fat sand rats (131 males and 125 females) seven to 41 months old were studied histologically. None of the sand rats had been used in experimental procedures prior to death. Diffuse polypoid hyperplasia or papilloma of the gallbladder mucosa was found in 49 sand rats. Of these lesions, 45 were present in 126 sand rats in the second half of their lifespan. Neither concretions nor signs of chronic inflammation were seen. Signs of focal epithelial growth activity were seen in either form of lesion. Epithelial hyperplasia was excessive in two gallbladders, and one was diagnosed as carcinoma-in-situ. The papilloma in one sand rat revealed transition to adenocarcinoma, with penetration into the deep layers of the gallbladder. Preneoplastic nodules were found in the liver as frequently as reported previously, but they were unrelated to gallbladder lesions. The unusual high incidence of spontaneous epithelial proliferation in the gallbladder mucosa in sand rats of both sexes through several generations suggests this strain as a model in the experimental study of tumorigenesis in the gallbladder.
Vesicular Exanthema of Swine and San Miguel Sea Lion Virus: Experimental and Field Studies in Otarid Seals, Feeding Trials in Swine
Authors: Gelberg H. B. , Dieterich R. A. , Lewis R. M.
Published: March 2010

The naturally occurring disease caused by San Miguel sea lion virus in fur seals was characterized by small fluid-filled vesicles 1 to 25 mm in diameter on the nonhaired portions of the flippers. Early epithelial lesions contained multifocal sites of cell lysis. The resultant microvesicles enlarged and coalesced, forming grossly visible macrovesicles. Mature vesicles progressed to involve all layers of the epithelium but did not involve the underlying dermis.

Intradermal inoculation of vesicular exanthema of swine virus type A48 or San Miguel sea lion virus type 2 into otarid (fur) seal pups caused plaque-like lesions around inoculated coronary bands. These swellings regressed without rupture by 96 hours postinoculation. One seal inoculated with San Miguel sea lion virus had a linear lingual erosion at ten days postinoculation. Virus was isolated from this site and from two uninoculated sites, the tonsil and testicle. Contact controls showed no evidence of infection.

Virus was isolated in low titers from some sites of inoculation and draining lymph nodes from seals infected with vesicular exanthema of swine virus. Virus was recovered more easily, in higher titers, and from more tissues, from seals infected with San Miguel sea lion virus. Inoculated seals tested after four to ten days seroconverted.

Feeding swine seal tissues from the inoculation experiments resulted in seroconversion in swine which were fed tissues from seals infected with vesicular exanthema of swine virus but not in those which were fed tissues from seals infected with San Miguel sea lion virus.
The Bovine Pulmonary Inflammatory Response: Adjuvant Pneumonitis in Calves
Authors: Lay J. C. , Slauson D. O.
Published: March 2010

Twenty one- to two-month-old Holstein, Angus, or Holstein-Angus crossbred calves were given intravenous complete Freund's adjuvant and their lungs were examined at 24 hours to 30 days post-injection. Two calves given intravenous saline served as normal controls. The evolving pulmonary inflammatory response was characterized initially by multifocal vasculitis and acute multifocal exudative pneumonitis which progressed to a granulomatous interstitial pneumonitis by seven days post-injection. Discrete granulomas characterized the lesions in the lungs and lymph nodes at 30 days post-injection, and granulomas also were seen in liver, kidney, and spleen. Clinically, the calves were tachypneic and pyrexic during the first week post-injection. Four calves developed acute pulmonary edema and died during, or shortly after, administration of the adjuvant. This model of experimental pneumonia in calves is similar to complete Freund's adjuvant-induced experimental pneumonia in other species. It is reproducible and predictable in its course of development and resolution, and provides a useful model for studying basic mechanisms of pulmonary inflammatory injury and repair in the bovine lung.
Fusarium-Induced Osteochondrosis (Tibial Dyschondroplasia) in Chickens
Authors: Walser M. M. , Allen N. K. , Mirocha C. J. , Hanlon G. F. , Newman J. A.
Published: March 2010

Broiler chickens were started and maintained on rations containing 2%, 5%, and 10% grain contaminated with Fusarium roseum. There was mortality of 75% and 100%, respectively, in chicks fed 5% and 10% levels, and osteochondrosis was present in chicks which died at 12 to 17 days of age. Chicks on 2% or 3% F. roseum-contaminated grain survived the experimental period and osteochondrosis was well-developed in the proximal tibias of 85 or 90% of these chicks. The number of chondroclasts was reduced markedly in the affected bones. Defective chondroclasis may play a role in the pathogenesis of osteochondrosis associated with F. roseum.
Observations on Normal Skeletal Muscle of Mature Dogs: A Cytochemical, Histochemical, and Morphometric Study
Authors: Braund K. G. , Mcguire J. A. , Lincoln C. E.
Published: March 2010

Cytochemical, histochemical, and morphometric features of skeletal muscle were evaluated in 140 specimens from five appendicular muscles of 28 dogs which were free of neuromuscular disease. Dogs ranged from six months to 15 years of age. Evidence of degeneration and regeneration, cell reactions and architectural change was found but with an incidence of less than 1% of the total myofiber population in any muscle. The number of fibers with internal nuclei never exceeded 1%. The only changes that appeared to be age-related were fiber size variation associated with the presence of small angular type IIA fibers in muscles of dogs seven years of age and older. Percentages of type I, type IIA, and type IIC fibers remained relatively constant in the various muscles in the age range examined. Type I fibers predominated in medial head of triceps brachii and superficial digital flexor muscles, whereas type IIA fibers were more numerous in biceps femoris and long head of triceps brachii muscles. An approximately equal ratio was found in gastrocranius muscles. In any given muscle, type IIC fibers represented less than 2% of the fibers. Statistically significant differences were found in values for fiber size between groups of dogs weighing more than (mean diameter range = 40 to 50 μm) and less than (mean diameter range = 30 to 40 μm) 15 kilograms.
Parasitic Encephalitis Due toBaylisascaris sp.in Wild and Captive Woodchucks (Marmota monax)
Authors: Roth L. , Georgi M. E. , King J. M. , Tennant B. C.
Published: March 2010

Twelve of 102 woodchucks submitted for necropsy to the New York State College of Veterinary Medicine had clinical histories of central nervous system disorder. All had multifocal eosinophilic encephalitis with formation of granulomas. Nematode larvae, identified as Baylisascaris sp. were found in six of the 12 and were assumed to be the etiologic agent in all affected woodchucks. Both wild and captive (wild-trapped) woodchucks were affected, and all occurrences were between mid-June and early September.
The Quantitative Clearance of Bacteria from the Bloodstream of Rainbow Trout (Salmo gairdneri)
Authors: Ferguson H. W. , Claxton M. J. , Moccia R. D. , Wilkie E. J.
Published: March 2010

The blood clearance of 51Cr-labelled heat-killed Salmonella pullorum was biphasic and exponential for each phase. This pattern was the same for all three concentrations of bacteria used. The initial more rapid phase lasted for approximately 15 minutes when roughly 90% of the bacteria had been cleared. The second slower phase started 25 to 30 minutes post-inoculation and lasted for approximately 25 to 30 minutes. The tissue distribution of bacteria showed that in both absolute and relative terms, the kidney was the most important organ, accounting for more than 70% uptake of the bacteria.

These kinetics demonstrate that rainbow trout at 8°C are able to clear their bloodstream of Salmonella very efficiently, in a fashion very similar to mammals. It is not known, however, which of the various possible clearance mechanisms dominates each phase.
Pathology of the Mononuclear Cell Leukemia of Fischer Rats. II. Hematology
Authors: Stromberg P. C. , Vogtsberger L. M. , Marsh L. R. , Wilson F. D.
Published: March 2010

Complete hemograms were evaluated for 57 rats with mononuclear cell leukemia and compared to hemograms obtained from 52 age- and sex-matched nonleukemic rats. All leukemic rats had marked hemolytic anemia and associated spherocytosis, reticulocytosis, anisocytosis, and polychromasia. The anemia varied with the stage of illness and was more severe in rats with advanced leukemia. Death appeared to be related to anemia. There was a marked neutrophilia with left shift, mild lymphopenia, and moderate to severe thrombocytopenia. Atypical mononuclear cells were detected in circulation in all but three rats. Total white blood cell counts ranged from 5.0-370 x 103 cells/ml. There was an increase in erythrocyte osmotic fragility with separation into two distinct populations of erythrocytes. Eight of nine rats were Coomb's positive indicating an immune-mediated pathogenesis for the anemia. Hemostasis tests revealed a markedly prolonged prothrombin time, hypofibrinogenemia, slightly increased to normal partial thromboplastin time, and undetected fibrin degradation products. These findings suggest significant liver disease associated with the leukemia.
Feline Mammary Sarcoma Composed of Cells Resembling Myofibroblasts
Authors: Hayden D. W. , Ghobrial H. K. , Johnson K. H. , Buoen L. C.
Published: March 2010

A recurrent mammary sarcoma from an 11-year-old, female domestic cat was studied by light and electron microscopy and immunohistochemistry. The tumor consisted of interlacing bands of spindle cells with elongated blunt-ended nuclei and variable amounts of stroma. Multinucleated tumor giant cells and mitoses were common. Ultrastructurally, tumor cells had abundant rough endoplasmic reticulum with dilated cisternae, a prominent Golgi complex, frequent mitochondria, bundles of intracytoplasmic filaments with focal densities, and discontinuous basal lamina-like material and cell junctions. These findings suggest that myofibroblast-like cells were the predominant type of tumor cell. Failure to demonstrate immunoreactivity for cytokeratins attested to the non-epithelial origin of these neoplastic cells. Uniform immunoreactivity with anti-vimentin antibodies and specific labelling of some tumor cells with antiserum to actin are compatible with an origin of this tumor from modified fibroblasts (i.e., myofibroblast-like cells). Tumors composed largely of myofibroblasts may be unique and warrant separate classification from other types of fibroblastic tumors in animals.
Acute Myelomonocytic Leukemia with Neurologic Manifestations in the Dog
Authors: Christopher M. M. , Metz A. L. , Klausner J. , Polzin D. , Hayden D. W.
Published: March 2010

A dog was presented with mandibular paralysis, photophobia, and diffuse atrophy of the cranial skeletal muscles. Physical examination also revealed glossal paralysis, reduction of the swallowing reflex, reduction of the pupillary light response, and generalized lymphadenopathy. Cytologic and ultrastructural examinations of blood films, bone marrow, and lymph node aspirates were consistent with acute myelomonocytic leukemia. Post-mortem examination revealed extensive, multisystemic neoplastic infiltration with marked involvement of the central and peripheral nervous systems, especially the cranial and lumbar spinal nerves and associated ganglia. Neurologic manifestations arc unusual in acute myelomonocytic leukemia in the dog.
Salmonella Osteomyelitis in a Rhesus Monkey
Authors: Klumpp S. A. , Weaver D. S. , Jerome C. P. , Jokinen M. P.
Published: March 2010

An adult male rhesus monkey ( Macaca mulatto) developed clinical signs of severe osteomyelitis of the left femur 42 days after onset of enteritis. Salmonella sp. were cultured from feces, blood, and femoral lesions. Response to antibiotic therapy was poor, and the animal was euthanized. The left femur, with pathologic fracture and involucrum, and the right femur, tibia and fibula were most severely affected. Additionally hepatic microgranulomas, mild tubulointcrstitial nephritis, medullary histiocytosis and erythrophagocytosisin the lymph nodes, and a mild colitis were diagnosed microscopically. The severity of the disease and serum electrophoresis findings were suggestive of lowered resistance to the organism, possibly due to anemia or polychlorinated biphenyl toxicosis.
Histochemical and Morphometric Evaluation of Skeletal Muscle from Horses with Exertional Rhabdomyolysis (Tying-up)
Authors: McEwen S. A. , Hulland T. J.
Published: March 2010

Thirteen horses with histories of exertional rhabdomyolysis were exercised for 20 minutes to induce clinical signs of lameness, elevated serum creatine kinase (CK), and aspartate aminotransferase (AST) activities and skeletal muscle morphologic lesions. The clinical signs exhibited by affected horses included trembling, sweating, increased rate of respiration, and restricted limb movement. Serum CK reached maximal activity between 4 and 8 hours after the exercise period and serum AST activity peaked between 24 and 48 hours. Histologically, the skeletal muscle lesions in muscle biopsies 24 hours after the exercise period consisted of segmental muscle fiber degeneration. Damaged muscle fibers were repaired by myoblastic regeneration. Horses with moderate (>1,500 U/liter) to severe (>5,000 U/liter) elevations of serum CK activity accompanied by clinical signs of muscle soreness induced by exercise, had visible muscle fiber degeneration microscopically. Frozen sections of biopsies of the gluteus medius muscle from affected ( n = 13) and control ( n = 11) groups of horses were processed to demonstrate myofibrillar ATPase activity. These sections were then used to determine fiber types, area percentages, and mean cross sectional fiber sizes. The mean type I, type II, and intermediate fiber sizes were significantly larger in the affected group than in the control group. In the gluteus medius muscles of the affected group, there was a significantly greater percentage of intermediate fibers and a significantly greater percentage of area occupied by intermediate fibers than in the control group. In the muscle samples with acute lesions of exertional rhabdomyolysis, type II fibers were selectively but not exclusively affected. In one horse which was subsequently necropsied 24 hours after the exercise period, lesions were present in several postural muscles, the masseter muscle and the heart. We conclude that the gluteus medius muscle fibers of affected horses are larger in cross sectional area than those of control horses and that there is preferential degeneration of type II fibers in acute lesions of exertional rhabdomyolysis.
Incidental Lesions in Nonhuman Primate Placentae
Authors: Bunton T. E.
Published: March 2010

Twenty-one placentae from uncomplicated pregnancies of rhesus macaques in the third trimester (124–164 days) were examined to determine placental incidental lesions. Placental weight (PW) generally correlated with fetal weight (FW); PW:FW equaled approximately 1:3. Most placentae were bidiscoid (9.5% monodiscoid) with eccentric cord insertion and marginal or circummarginate membrane insertion. Macroscopically, there was in varying degrees, subchorionic, perivillous, and perilobular fibrin deposition, focal infarction, retroplacental hematoma, and calcification. Histologic changes included fibrinoid necrosis of villi, multifocal acute inflammation, excessive cytotrophoblasts, formation of syncytial knots, and intimal proliferation in umbilical vessels. Volume density of fibrinoid necrosis and calcification in terminal villi showed nonstatistically significant increases to term. However, calcification in reference to entire placental tissue increased significantly to term. All lesions seen in the rhesus are also seen incidentally in human placentae, but may become significant in correlation with pregnancy wastage if present to a large degree.
Ultrastructure of Fusarium-induced Tibial Dyschondroplasia in Chickens: A Sequential Study
Authors: Haynes J. S. , Walser M. M.
Published: March 2010

Female broiler chicks were randomly placed into two groups; one was treated twice daily with TDP-1 (a mycotoxin produced by Fusarium roseum), the other was controls. Chicks were sacrificed after 2, 4, 6, 8, 10, and 14 days of treatment and were evaluated for tibial dyschondroplasia. TDP-1-treated chicks examined after 2, 4, or 6 days of treatment had either no gross lesions (2 days) or mild gross lesions (4 and 6 days); growth plates from these groups did not have ultrastructural changes. TDP-1-treated chicks examined after 8, 10, or 12 days of treatment had moderate to severe gross lesions of tibial dyschondroplasia. These groups also had intracellular lipid accumulation and necrosis of chondrocytes within the retained cartilage. It was concluded that the cellular changes in tibial dyschondroplasia develop only after the cartilage accumulates; the changes are sequelae, possibly due to nutrient depletion from an increased distance between chondrocytes and perforating epiphyseal vessels, their nutrient source.
Pi Granules and Related Intracytoplasmic Inclusions in Equine Schwann Cells
Authors: Force L. , Jortner B. S. , Scarrat K.
Published: March 2010

Suchwann cells from a variety of nerves in two adult horses and one adult pony contained perinuclear intracytoplasmic inclusion complexes consisting of lipid droplets, variably electron-dense rounded to elongated bodies and rod-shaped multilamellar structures. The latter were characteristic of pi granules of Reich. There were no significant axonal or myelin alterations associated with these inclusions. It was concluded that the inclusions are a component of normal equine Schwann cells.
The Pathogenesis and Significance of Pre-iridal Fibrovascular Membrane in Domestic Animals
Authors: Peiffer R. L. , Wilcock B. P. , Yin H.
Published: March 2010

Histologic examination was made of 1,419 globes from domestic animals (964 dogs, 374 cats, 41 horses, and 40 cattle) with ocular disease; pre-iridal membranes (rubeosis iridis) were found in 98. The membranes originated as endothelial budding from the anterior iridal stroma and seemed to mature into fibrous or fibrovascular membranes that were often followed by hyphema or, occasionally, glaucoma. Pre-existent disease in the 98 affected globes included chronic endophthalmitis (27/98), chronic glaucoma (24/98), anterior uveal melanoma (15/98), ciliary body adenoma (14/98), neoplasms metastatic to the eye (8/98), and chronic retinal detachment (6/98). In terms of likelihood of occurrence, pre-iridal membranes seen in 21% (6/21) of globes with retinal detachment, 19% (14/75) of those with ciliary body adenomas, 14% (24/167) of those with chronic glaucoma, and 10% (15/158) of those with anterior uveal melanoma. They were detected with greatest relative frequency in horses (9/41) followed by dogs (83/964), cats (5/374) and cattle (1/40). These membranes, which are rarely detected by clinical examination, probably from in response to angiogenic factors released by ischemic retina, by neoplasms, or by leukocytes involved in ocular inflammation.
Canine Extraskeletal Osteosarcoma and Chondrosarcoma: a Clinicopathologic Study of 14 Cases
Authors: Patnaik A. K.
Published: March 2010

Canine extraskeletal osteosarcomas are extremely rare tumors. Over a period of 25 years at the Animal Medical Center, approximately 1,000 cases of skeletal osteosarcomas have been diagnosed. During the same period 11 cases of extraskeletal osteosarcomas and three extraskeletal chondrosarcomas were diagnosed. Tumors of the mammary gland were excluded. Extraskeletal osteosarcomas were found in the adrenal gland, eye, gastric ligament, ileum, kidney, liver, spleen, testicle, and vagina. The chondrosarcomas were found in the mitral valves, lungs, and omentum. The mean age of the dogs with extraskeletal osteosarcoma was 11 years, and the mean age of the dogs with extraskeletal chondrosarcoma was 14 years. The sizes of the tumors ranged from 3 cubic centimeters to 8,315 cubic centimeters. Osteoblastic osteosarcomas were the most common histologic type (7/11, 63.6%); there was a single case of each of the following: fibroblastic, fibrous histiocytic, chondroblastic, and mixed osteo-chondroblastic osteosarcoma. Two of the dogs with chondrosarcomas had mesenchymal chondrosarcomas involving the lungs and omentum. The remaining dog had a regular chondrosarcoma involving the mitral valve. Distant metastases were present in seven of 11 dogs with extraskeletal osteosarcoma and in none of the dogs with chondrosarcoma. In contrast to human beings, in which most extraskeletal osteosarcomas occur in the soft tissues and the extremities, most canine extraskeletal osteosarcomas develop in the visceral organs.
Phenotypic Characterization of Normal and Neoplastic Canine Endothelial Cells by Lectin Histochemistry
Authors: Augustin-Voss H. G. , Smith C. A. , Lewis R. M.
Published: March 2010

Cell surface glycoconjugate expression of endothelial cells in canine cutaneous hemangiomas and hemangiosarcomas was compared to normal cutaneous endothelial cells using eight different lectins (with and without neuraminidase pretreatment) in an indirect immunoperoxidase technique. Direct comparison of lectin binding pattern of neoplastic endothelial cells with adjacent normal endothelial cells revealed minor changes in the binding intensity of several lectins (enhanced: Wheat germ agglutinin [WGA]; reduced: Griffonia simplicifolia-I [GS-I], Ricinus communis agglutinin-I [RCA-I], Soybean agglutinin after neuraminidase pretreatment [Neu-SBA], and Wheat germ agglutinin after neuraminidase treatment [Neu-WGA]). Neoplastic endothelial cells in some tumors exhibited varying binding of Ulex europaeus agglutinin-I (UEA-I; not binding to normal canine endothelial cells) and no Soybean agglutinin (SBA) binding (variably binding to normal endothelial cells in small cutaneous vessels). Lectin binding of neoplastic cells was rather heterogenous within one tumor compared to the uniform binding pattern of normal endothelial cells. These lectin binding studies demonstrate the phenotypic heterogeneity of neoplastic endothelial cells, indicating changes of cell surface glycosylation during neoplastic transformation.
Gastric Stromal Tumors in Two Rhesus Macaques (Macaca mulatta)
Authors: Banerjee M. , Lowenstine L. J. , Munn R. J.
Published: March 2010

Two female rhesus monkeys ( Macaca mulatta, 10 and 24 years old) developed microcytic anemia and became terminally ill. At necropsy, large gastric masses were present, and, in one case, there were widespread abdominal metastases. Except for slightly atypical patterns, at the light microscopic level, the lesions resembled smooth muscle tumors. Ultrastructurally, however, cells in both tumors resembled primitive mesenchyme, while in one of the tumors, there were some characteristics of Schwann cells. No ultrastructural features of smooth muscle were present in either tumor. Vimentin and S-100 were detected immunohistochemically in both tumors. S-100 staining was more intense in the tumor with ultrastructural features of Schwann cells. Actin and desmin were not expressed in either gastric tumor, but diffusely stained a uterine tumor that was concomitantly present in one of the rhesus monkeys. The uterine tumor also exhibited typical ultrastructural features of smooth muscle. In the past, gastrointestinal stromal tumors in all species were thought to be of smooth muscle origin. Recently in human pathology, this conventional viewpoint has given way to the realization that there is a spectrum of neural crest and mesenchymal tumors. We report two gastric stromal tumors in two rhesus monkeys that histologically resembled smooth muscle tumors but were of neuroectodermal and primitive mesenchymal origin.
Neospora-like Protozoal Infections Associated with Bovine Abortions
Authors: Barr B. C. , Anderson M. L. , Dubey J. P. , Conrad P. A.
Published: March 2010

Eighty bovine fetuses with presumed protozoal infections from a previous 2-year retrospective study were examined by immunohistochemistry using antisera against Neospora caninum. In 66 (83%) of the fetuses, protozoa were found that reacted positively with anti- N. caninum sera. In three (4%) additional fetuses, protozoa identified as Sarcocystis species did not react, and in two fetuses (3%) single protozoal clusters were found only in hematoxylin and cosin-stained slides. A group of 20 fetuses were chosen for further evaluation. They included 14 fetuses from the first group of 80 fetuses plus six additional fetuses that had large numbers of protozoa in the fetal brain. The 20 fetuses were examined immunohistochemically with antisera to N. caninum, Hammondia hammondi, and Toxoplasma gondii. Protozoa from 3/20 fetuses, identified as Sarcocystis species, failed to react with any antisera. In 16/20 fetuses protozoa reacted positively to antisera against N. caninum, and in most cases reacted to H. hammondi, and weakly to one or more of the antisera against T. gondii. Thickwalled protozoal tissue cysts were found in the brain of four of these 16 fetuses by transmissiosn electron microscopy. The cyst wall morphology was comparable to N. caninum. The results suggested that a single protozoal parasite of unknown identity was responsible for most of the bovine abortions. By immunohistochemistry, the unknown protozoon reacted most strongly and consistently to N. caninum antisera, but was antigenically distinct from N. caninum. Ultrastructurally, tissue cysts found in four fetuses most closely resembled Neospora caninum.
A Novel DNA Virus Associated with Feather Inclusions in Psittacine Beak and Feather Disease
Authors: Latimer K. S. , Rakich P. M. , Steffens W. L. , Kircher I. M. , Ritchie B. W. , Niagro F. D. , Lukert P. D.
Published: March 2010

The nature of feather inclusions was characterized in 32 psittacine birds (30 cockatoos, one peachfaced lovebird ( Agapornis roseicollis), and one red-lored Amazon parrot ( Amazona autumnalis autumnalis)) with naturally-acquired psittacine beak and feather disease. Intranuclear inclusions within feather epithelial cells and intracytoplasmic inclusions within macrophages in the feather epithelium and pulp cavity contained psittacine beak and feather disease viral antigen when stained by the avidin-biotin complex immunoperoxidase technique. Ultrastructurally, inclusions were observed primarily within macrophages and to a lesser extent within epithelial cell nuclei. Macrophage inclusions appeared as paracrystalline arrays of viral particles. Intranuclear inclusions were less well defined, although scattered viral particles were present. Intracytoplasmic and intranuclear particles in ultrastructural preparations were identified by colloidal gold labeling as psittacine beak and feather disease virus. Feather epithelium was more frequently and severely involved in the disease process than was adjacent follicular epithelium. Plucked feathers with an intact epidermal collar and feather epithelium were preferred to follicular biopsies for histopathologic examination.
Myoepitheliomas in Inbred Laboratory Mice
Authors: Sundberg J. P. , Hanson C. A. , Roop D. R. , Brown K. S. , Bedigian H. G.
Published: March 2010

Myoepitheliomas are subcutaneous tumors that arise from myoepithelial cells of various exocrine glands. In a retrospective study of 142 tumors observed over a period of 3 years, myoepitheliomas occurred spontaneously in A/HcJ, A/J, BALB/cJ, BALB/cByJ, LLC,A/Ckc, and NOD/Lt inbred strains of mice. Tumors presented primarily in the subcutaneous tissues of the ventral neck (74% of the myoepitheliomas evaluated) but were observed in several other subcutaneous locations, including the head, perineum, and ventral abdomen. These areas were adjacent to salivary, mammary, clitoral, preputial, and Harderian glands. Forty myoepitheliomas were tested by the avidin-biotin complex technique with a panel of antisera specific for mouse keratins, intermediate filaments, and other cytoskeletal proteins to determine the cell type from which this neoplasm originated. Antibodies directed against the specific mouse keratins K5, K6, and K14, and a broadly crossreactive cytokeratin antibody stained acinar and ductal myoepithelial cells in normal mammary, salivary, and Harderian glands, and neoplastic cells in all cases. Antisera directed against a smooth muscle actin (anti-α-sm-1) stained acinar myoepithelial cells of the glands and vascular smooth muscle but neither ductular myoepithelial cells nor tumor cells. This supports the notion that these tumors originate from extraglandular ductular myoepithelial cells. Southern blots, prepared from DNA extracted from nine myoepitheliomas, did not show restriction fragment length polymorphisms when mouse mammary tumor virus (MMTV) cDNA or Int-1 genomic DNA probes were used; this implies that a retrovirus is not the etiologic agent.
Immunocytochemistry of Canine Thyroid Tumors
Authors: Leblanc B. , Parodi A. L. , Lagadic M. , Hurtrel M. , Jobit C.
Published: March 2010

Immunocytochemical studies using the peroxidase-antiperoxidase method with commercial antibodies against thyroglobulin, calcitonin, calcitonin gene-related peptide (CGRP), neuron specific enolase(NSE), somatostatin, and neurotensin were performed on 38 Bouin-fixed, paraffin-embedded canine thyroid tumors obtained from necropsy and surgical files from 2 Ecoles Nationales Vétérinaires (Alfort and Nantes, France) and from the Laboratoire d'Histo-Cytopathologie Vétérinaire, Maisons-Alfort (France). The tumors consisted of two follicular adenomas, nine follicular carcinomas, nine solid carcinomas, 12 follicular-compact-cellular carcinomas, and six C-cell carcinomas. All 32 follicular-cell tumors were stained positively for thyroglobulin, half of them had weak to moderate positive immunoreactivity for NSE, and all histologic patterns were represented. They had no immunoreactivity for somatostatin or neurotensin. Four C-cell carcinomas had a solid alveolar pattern, while two had a pseudo follicular pattern characterized by uneven, often coalescent, pseudofollicular formations with a multilayered epithelium surrounding a cavity that often contained red blood cells. Four C-cell carcinomas had uneven immunoreactivity for calcitonin, while all six were positive for CGRP or NSE. Immunoreactivity for CGRP was stronger or more widespread than positivity for calcitonin when both occurred in the same tumor. Some cells of three C-cell carcinomas had positive immunoreactivity for somatostatin. No immunoreactivity for neurotensin was detected. Seven tumors of follicular cell origin contained a few cells positive for calcitonin or CGRP, while three C-cell carcinomas had a few cells positive for thyroglobulin. These tumors were considered to contain entrapped remnants of normal thyroid tissue rather than being dual hormone producing tumors.
Immunohistochemical, Ultrastructural, and Hormonal Studies on the Endocrine Pancreas of Voles (Microtus arvalis) with Monosodium Aspartate-induced Diabetes
Authors: Sasaki M. , Arai T. , Usui T. , Oki Y.
Published: March 2010

A single subcutaneous administration of monosodium aspartate (MSA) to 30 neonatal voles, Microtus arvalis Pallas, induced a diabetes mellitus in 50% of the treated animals in early adulthood. The voles (18 males and 12 females) were weaned at 3 weeks of age and fed pellets for Herbivora and cubed hay. Diabetic voles with glycosuria (nine males and six females) were classified into two groups according to the duration and grade of glycosuria. One group had slight diabetes with glycosuria (+: 0.1%) for 1 week and the other severe diabetes with marked glycosuria (+++: ≧0.5%) for over 4 weeks. Pancreatic islets of diabetic voles ( n = 7) were examined immunohistochemically, light microscopically, and electron microscopically. Blood glucose concentration and tissue content of insulin, glucagon, and somatostatin were also measured. Slightly diabetic voles ( n = 3) had enlarged islets, that, viewed by light microscopy, were characterized by hypertrophy and hyperplasia of β cells with moderate degranulation. No changes were observed in the peripherally located α and β cells; the voles were moderately hyperglycemic, and they had decreased pancreatic insulin content. Severely diabetic voles ( n = 4) that had marked hyperglycemia and almost complete loss of insulin content showed marked vacuolation and degranulation of β cells. In addition, altered distribution of α and β cells from the periphery of the islets to their interior was noted. Ultrastructural examination revealed features compatible with those of hyperfunction of β cells in the slightly diabetic voles and marked degeneration of β cells with glycogen accumulation in the severely diabetic voles. In contrast, α and β cells retained their normal morphologic traits, even in the severely diabetic voles.
Enterovirulence of EnterotoxigenicBacteroides fragilisin Gnotobiotic Pigs
Authors: Duimstra J. R. , Myers L. L. , Collins J. E. , Benfield D. A. , Shoop D. S. , Bradbury W. C.
Published: March 2010

A porcine isolate of enterotoxigenic Bacteroides fragilis colonized the intestinal tract and caused watery, nonhemorrhagic diarrhea when given orally to 12, 1- to 2-day-old gnotobiotic pigs. Diarrhea occurred 2 to 3 days post-inoculation and continued throughout the 4 to 6 day post-inoculation period. Diarrheic pigs became mildly anorexic and dehydrated. They developed intestinal lesions characterized by swelling, vacuolation, and exfoliation of enterocytes, and crypt hyperplasia throughout the large intestine and, to a lesser extent, in the distal small intestine. Bacterial adherence to, or invasion of, the intestinal mucosa was not detected. A porcine isolate of nonenterotoxigenic B. fragilis was administered orally to six control pigs. The isolate colonized the intestinal tract, but the pigs did not develop clinical disease or intestinal lesions. The pathogenetic mechanism of the disease may involve mediation by a soluble enterotoxin (or toxins) elaborated by B. fragilis.
Expression of Epidermal Growth Factor Receptor in Plutonium-239-induced Lung Neoplasms in Dogs
Authors: Gillett N. A. , Stegelmeier B. L. , Kelly G. , Haley P. J. , Hahn F. F.
Published: March 2010

The expression of epidermal growth factor receptor (EGF-R) was examined in canine lung tumors and in proliferative epithelial foci induced by plutonium-239 to determine if EGF-R was associated with specific neoplastic phenotypes or putative preneoplastic lesions. Seventeen (47%) of 36 canine lung tumors expressed EGF-R. Of these 17 tumors, three tumors hybridized with an erb-B RNA probe, which identified activated cell oncogenes. The expression of EGF-R was not correlated with tumor etiology, e.g., spontaneous versus radiation induced, but did correlate with specific histologic phenotypes. Nineteen (15%) of 127 proliferative epithelial foci in the canine lungs also expressed EGF-R. The phenotypic specificity demonstrated for EGF-R in canine lung tumors parallels that previously shown in human lung tumors. This finding, in addition to the identification of EGF-R in nonneoplastic proliferative lung lesions, indicates that radiation-induced lung tumors in the dog may be a useful animal model to investigate the role of EGF-R in lung carcinogenesis.
Bovine Focal Proliferative Fibrogranulomatous Panniculitis (Lechiguana) Associated withPasteurella granulomatis
Authors: Riet-Correa F. , Méndez M. C. , Schild A. L. , Ribeiro G. A. , Almeida S. M.
Published: March 2010

In southern Brazil, cattle are affected by a disease known locally as Lechiguana and characterized by large subcutaneous swellings. Eighteen cases were examined clinically; 17 of the cattle had a single swelling, and one had two swellings. In 14 of the 18 cases, the swellings were located over the scapula and adjacent regions. The subcutaneous masses reached maximum dimensions of 45 × 50 cm, with heights above the skin surface of 5–25 cm. Growth was rapid, often taking place in 15 to 60 days. Histologically, all lesions were focal proliferative fibrogranulomatous panniculitis and consisted of focal proliferation of fibrous tissue that was infiltrated by plasma cells, eosinophils, lymphocytes, and sometimes neutrophils. An eosinophilic lymphangitis was also present, which sometimes resulted in the destruction of the lymphatics and the formation of eosinophilic microabscesses. Small granulomas, sometimes containing radiating clubs, and Splendore-Hoeppli material were present in the regional lymph node. Pasteurella granulomatis was isolated from the subcutaneous masses of 14 of the 18 natural cases. All 11 of these cases recovered following treatment with 3 g of chloramphenicol daily for 5 days. Untreated animals died. Because the area of anatomic distribution is similar to that infested by Dermatobia hominis, we postulate that this insect may transmit the causative agent. In one steer, a subcutaneous injection of P. granulomatis caused a large subcutaneous swelling consisting of interlacing bundles of collagen infiltrated by neutrophils, eosinophils, and some lymphocytes. Microabscesses, but not lymphangitis and granulomas, were detected. In all 11 cattle inoculated either intramuscularly or subcutaneously with P. granulomatis, purulent abscesses were produced at the sites of the injection, and P. granulomatis was recovered from all lesions.
Pulmonary Inflammation Associated with Aspirated Meconium and Epithelial Cells in Calves
Authors: Lopez A. , Bildfell R.
Published: March 2010

“Meconium aspiration syndrome” is a condition resulting in respiratory distress and the occasional death of newborn human beings. A retrospective study was conducted on 52 calves that were submitted for postmortem examination to the Atlantic Veterinary College, Charlottetown, Prince Edward Island, Canada. These calves died of infectious and noninfectious diseases within the first 2 weeks of life due to a variety of causes. The most common cause of death was infectious enteric disease. Histologic examination of lungs revealed that 42.5% of calves had evidence of meconium, squamous cells, or keratin in the lung. There was considerable variation in the magnitude of histologic changes in lungs containing aspirated material. Typically, affected lungs had only a few inconspicuous pieces of meconium, keratin, and squamous cells within bronchoalveolar spaces. Sporadically, the entire lumen of airways was obliterated by aspirated material. Lungs with aspirated material had a mild but diffuse alveolitis characterized by exudation of a few neutrophils, macrophages, and occasional multinucleated giant cells. Obstruction of small airways and focal atelectasis were also observed. Similar lesions have been reported in human meconium aspiration syndrome. It is concluded that histologic changes similar to those of human meconium aspiration syndrome occur commonly in calves that die within 2 weeks of birth. Further studies involving healthy age-matched calves are required to evaluate the clinicopathologic significance of meconium aspiration in this species.
Colonization of the Small Intestine of Weaned Pigs by EnterotoxigenicEscherichia colithat Lack Known Colonization Factors
Authors: Nagy B. , Arp L. H. , Moon H. W. , Casey T. A.
Published: March 2010

Intestinal colonization of 3-week-old weaned pigs by enterotoxigenic Escherichia coli (ETEC) strains that were originally isolated from weaned pigs with fatal diarrhea and that lacked K88, K99, F41, and 987P adhesins (4P−ETEC) was studied by histologic, immunofluorescent, and electron microscopic techniques. In the first experiment, 16 principal pigs were inoculated orogastrically with ETEC strain 2134 (serogroup 0157:H19) or 2171 (serogroup 0141:H4), and eight control pigs were not inoculated. In the second experiment, 24 principals were inoculated with ETEC strain 2134, and 12 controls were inoculated with a nonenterotoxigenic strain of E. coli. Principal and control pigs were necropsied at intervals from 24 to 72 hours after inoculation of principals to provide the tissues used for this report. Results from the two experiments and with both ETEC strains were similar and therefore were combined. Adhesion by 4P″ ETEC was demonstrated in ileum but not in cecum or colon in 22/40 principal pigs sampled at 24 to 72 hours after orogastric inoculation. Adherent bacteria were most apparent on the intestinal villi covering Peyer's patches. Only occasional adherent bacteria were detected in ileal sections from a few (4/20) of the control pigs. Adherence by 4P−ETEC was characterized by “patches” of bacteria closely associated with the lateral surfaces and less frequently with the tips and the bases of intact villi. In most cases, the adherent bacteria were separated from epithelial cell microvilli and other bacterial cells by a 50–400-nm space. Filamentous bacterial appendages bridged this space and formed a network among adjacent bacteria. Colonization of weaned pigs by the 4P−ETEC strains was characterized by preferential adhesion of bacteria to the villi covering Peyer's patches. The filamentous appendages observed between bacteria and microvilli are previously unrecognized fimbrial adhesins, which mediate colonization by these ETEC.
Carbonic Anhydrase Localization in Normal and Osteochondrotic Joint Cartilage of Growing Pigs
Authors: Ekman S. , Ridderstråle Y.
Published: March 2010

The histochemical localization of carbonic anhydrase in the normal and osteochondrotic epiphyseal growth cartilage from 15 growing pigs (6 to 18 weeks old) was studied. All animals were clinically normal. The entire thickness of the articular-epiphyseal cartilage complex from the femoral condyles was fixed in 2% glutaraldehyde and embedded in a water-soluble glycolmethacrylate. Sections (1–2 μm) were incubated on the surface of a medium containing cobalt, phosphate, and bicarbonate. A black precipitate formed at sites of enzymatic activity. This method shows the activity of all different isoenzymes of carbonic anhydrase. The specificity was checked by adding the carbonic anhydrase inhibitor acetazolamide to the incubation medium. Osteochondrosis in the epiphyseal growth cartilage was characterized by chondronecrotic areas in resting, proliferative, hypertrophic, and calcifying regions. When the hypertrophic and calcifying regions were involved, insufficient cartilage calcification and focally impaired ossification were seen. The chondronecrotic areas were surrounded by groups of morphologically viable cells, or so-called “clusters.” Carbonic anhydrase was present in chondrocytes of hypertrophic and calcifying regions of the normal growth cartilage and in osteoclasts and erythrocytes. No evidence of carbonic anhydrase activity was found in the articular cartilage or in the resting region of normal growth cartilage in any of the pigs. No enzyme activity was found in the osteochondrotic cartilage, either in clusters or dead cells. The lack of carbonic anhydrase in the osteochondrotic cartilage demonstrated in this study may result in an inability to produce the alkaline matrix necessary for calcification and could be one reason for the insufficient calcification typical of this cartilage.
A Retrospective Clinicopathologic Study of 212 Dogs with Cutaneous Hemangiomas and Hemangiosarcomas
Authors: Hargis A. M. , Ihrke P. J. , Spangler W. L. , Stannard A. A.
Published: March 2010

The relationship between skin pigmentation and piliation and the development of hemangiomas and hemangiosarcomas in the dermis and subcutaneous tissue was studied in 212 dogs. These 212 dogs had a combined total of 306 tumors; 38 of these 212 dogs had two or more of the same tumor in a different location or a combination of hemangioma and hemangiosarcoma. The average age of the dogs at the time of excision of these tumors was greater than 10 years. There was no sex predilection for the presence or absence of tumors. Cutaneous hemangiomas (73%) were more common than cutaneous hemangiosarcomas (27%). Hemangiomas had no predilection for dermis (51%) or subcutaneous tissue (47%), but hemangiosarcomas had a marked predilection for dermis (73%) over subcutaneous tissue (7%). Dogs with short hair coats and lightly pigmented skin had more hemangiomas and hemangiosarcomas of the dermis (65%) than did dogs with variable length hair coats and pigmentation (28%). Dogs with short hair coats and lightly pigmented skin had fewer hemangiomas and hemangiosarcomas of the subcutaneous tissue (10%) than did dogs with variable length hair coats and pigmentation (22%). Dogs with short hair coats and lightly pigmented skin also had more hemangiomas and hemangiosarcomas of ventral glabrous skin (65%) than did dogs with variable length hair coats and pigmentation (22%). In addition, there was no predilection of subcutaneous hemangiosarcoma for haired (33%) versus glabrous (33%) skin, but dermal hemangiosarcoma had a marked predilection for the glabrous skin (63%) when compared with haired skin (10%). The increased incidence of dermal hemangiomas and hemangiosarcomas in ventral glabrous skin suggests an association between solar radiation and the biologic properties of glabrous skin in the genesis of these tumors.