bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Airsacculitis in Turkeys Inoculated with Cell-free Culture Filtrate ofPasteurella multocida
Authors: Ficken M. D. , Barnes H. J. , Qureshi M. A.
Published: March 2010

Twenty-six female and 26 male turkeys, inoculated into the caudal thoracic air sacs with cell-free culture nitrate of Pasteurella multocida strain R44/6, were examined from 0 to 6 hours post-inoculation and compared with 26 female and 26 male sham-inoculated control turkeys given brain-heart-infusion broth. The air sac reacted rapidly with exudation of heterophils. Microscopically, low numbers of heterophils were present within air sac blood vessels and also perivascularly by 0.5 hour after inoculation. These became more numerous by 1.5 and 3 hours post-inoculation. By 6 hours post-inoculation, there was severe swelling of air sac epithelial and mesothelial cells and thickening of the air sac by proteinaceous fluid and heterophils. Ultrastructurally, mesothelial and air sac epithelial cells were vacuolated, and interdigitating processes of epithelial cells were separated. Microscopically, in control turkeys, rare heterophils were present perivascularly at 1.5, 3, and 6 hours after inoculation. Ultrastructurally, all features were normal. In turkeys given cell-free culture filtrate, total cell counts in air sac lavage fluids increased markedly by 3 hours post-inoculation in which heterophils predominated (>97%). There were only slight increases in cell counts of air sac lavages from control turkeys. The circulating blood heterophil cell count dropped transiently at 1.5 hours post-inoculation, followed by a return to normal 3 hours after inoculation, and by heterophilia by 6 hours post-inoculation in turkeys given either cell-free culture filtrate or brain-heart-infusion broth. These results indicate cell-free culture filtrate of P. multocida induces hematologic, cytologic, and morphologic changes indistinguishable from those induced by cultures of P. multocida.
Ultraviolet Radiation-induced Skin Tumors in a South American Opossum (Monodelphis domestica)
Authors: Kusewitt D. F. , Applegate L. A. , Ley R. D.
Published: March 2010

A total of 19 male and 21 female South American opossums ( Monodelphis domestica) were exposed to 250 J/m2 ultraviolet radiation from FS-40 sunlamps (280-400 nm) three times weekly for 70 weeks. The backs of the opossums were shaved as necessary to remove hair. In order to prevent photoreactivation of ultraviolet radiation-induced pyrimidine dimers by the light-dependent photolyase enzyme of the opossum, ultraviolet radiation-exposed opossums were housed under red lights (600-800 nm). The opossum photolyase requires light in the 320-450 nm range for its activity. Twenty-nine control opossums (14 males and 15 females) were irradiated by fluorescent lights with emission spectra primarily in the visible light range (320-700 nm); these control opossums were also housed under red lights, and their backs were also shaved to remove hair. No skin tumors were observed in control opossums, while ultraviolet radiation-exposed opossums developed a variety of hyperplastic and neoplastic skin lesions on the backs and on a single ear. Hyperplastic lesions included foci of epithelial hyperplasia, dermal fibroplasia, and focal proliferation of dermal melanocytes. A total of 20 ultraviolet radiation-exposed opossums (50%) developed skin tumors, and 13 opossums (32.5%) had more than a single tumor. Epithelial tumors included 25 papillomas, four keratoacanthomas, seven carcinomas in situ, three microinvasive squamous cell carcinomas, two invasive squamous cell carcinomas, and a single basal cell tumor. Ten dermal spindle cell tumors also occurred; most of these appeared to be fibrosarcomas. Two benign melanomas and one malignant melanoma were observed.
Structural and Biochemical Changes in a Spinal Myelinopathy in Twelve English Foxhounds and Two Harriers
Authors: Sheahan B. J. , Caffrey J. F. , Gunn H. M. , Keating J. N.
Published: March 2010

Degenerative lesions in the spinal cord white matter of 12 English Foxhounds and two Harriers between 3 and 6 years old were associated with a diet composed mainly of ruminant stomachs. Lesions were present throughout the length of the spinal cord and were more severe in ventral and lateral columns than in dorsal columns. Degenerate fibers were accompanied by astrocytic proliferation. Changes suggestive of a primary myelinopathy included vacuolated myelin sheaths around apparently intact axons and thick-thin transitions in myelin sheath thickness. Mixed sensory and motor peripheral nerves and muscle histochemical fiber type profiles appeared normal. Similarities were noted with the changes described in subacute combined degeneration of the spinal cord in human beings, a neuropathy caused by methionine and methylation deficiency in patients with vitamin B12 deficiency. Mean serum methionine levels were significantly lower ( P > 0.01) and mean liver methionine synthetase levels were significantly greater ( P > 0.01) in affected dogs restored to a balanced diet than in age-matched controls maintained on the balanced diet. The elevated methionine synthetase levels possibly reflected compensatory reactions to the associated dietary change.
Cutaneous Plasmacytomas with Amyloid in Six Dogs
Authors: Rowland P. H. , Valentine B. A. , Stebbins K. E. , Smith C. A.
Published: March 2010

Cutaneous plasmacytomas associated with local deposition of amyloid were diagnosed by light microscopy in a series of six older dogs (mean age 10.7 years) consisting of two Cocker Spaniels, a Poodle, a Weimeraner, and two mixed-breed dogs. The neoplasms occurred on the digits (2 dogs), forelimb (2 dogs), lip (1 dog), and ear (1 dog). In most cases, groups of neoplastic plasma cells were widely separated by large homogeneous islands of amyloid. The neoplastic cells had characteristic plasmacytoid features, but the degree of pleomorphism varied greatly between different neoplasms. In four of the six tumors, the diagnosis of plasmacytoma was confirmed by the demonstration of a monoclonal plasma cell population using immunofluorescent staining for anti-canine immunoglobulins. In these tumors, the neoplastic cells reacted with only one class of immunoglobulins (IgG). The amyloid did not react with any of the reagents used. The suspicion that the amyloid was of immunoglobulin origin (primary amyloid) was supported by its retention of birefringence under polarized light after treatment with potassium permanganate and staining with Congo red.
Mycobacterium paratuberculosisMonoassociated Nude Mice as a Paratuberculosis Model
Authors: Hamilton H. L. , Cooley A. J. , Adams J. L. , Czuprynski C. J.
Published: March 2010

In this study, a paratuberculosis (Johne's disease) model was developed by intragastrically dosing gnotobiotic athymic nude mice with Mycobacterium paratuberculosis. The mice infrequently shed bacilli from their intestinal tracts during the first 4 months after inoculation. Following this time, increasing numbers of M. paratuberculosis (greater than 4.0 log10bacilli per fecal pellet by 40 weeks) were recovered from the feces of the 12 mice that remained in the isolator. A similar pattern of recovery of M. paratuberculosis was obtained from the ileum, cecum, colon, and liver. Histopathologic lesions and acid-fast bacilli were rare during the first 4 months of infection and then, with time, increased in prevalence and severity. Mice maintained for 7 months or longer exhibited severe granulomatous inflammation and large numbers of acid-fast bacilli in the gastrointestinal tract and liver (up to 105log10, colony forming units per gram wet weight). Five mice maintained for 7 months or more developed clinical signs consistent with those seen in paratuberculosis (weight loss, chronic diarrhea); three of these mice eventually died or became moribund and were euthanatized. M. paratuberculosis monoassociated mice released increased levels of tumor necrosis factor activity into their sera, as compared to uninfected control mice, when they were injected with bacterial Iipopolysaccharide. The clinical signs, fecal shedding of M. paratuberculosis, granuloma formation, and progressive bacillary multiplication observed with these mice are consistent with naturally occurring M. paratuberculosis infection of ruminants (Johne's disease). This model will be useful for future studies of immunoregulation and antimicrobial therapy of paratuberculosis.
A Retrospective Survey of Endocardial Proliferative Lesions in Rats
Authors: Novilla M. N. , Sandusky G. E. , Hoover D. M. , Ray S. E. , Wightman K. A.
Published: March 2010

Sixty, proliferative, endocardial lesions were diagnosed in 19,304 rats, for an overall incidence of 0.3%. This population consisted of 10,127 Fischer 344,8,737 Wistar, 200 Sprague-Dawley, and 240 Long Evans rats from chronic/oncogenicity studies reported at Lilly Research Laboratories from 1976 to 1988. Of the 60 proliferative lesions, 44 were classified as endocardial hyperplasia, 15 as endocardial schwannomas, and one as an endocardial sarcoma for prevalence rates of 0.2%, 0.08%, and 0.005%, respectively. Affected rats ranged in age from 42 to 110 weeks. There were no sex or treatment-related differences in the prevalence of the rat endocardial proliferative lesions. A review of endocardial lesions in 18 of 233 Wistar rats treated with carbamate derivatives revealed endocardial hyperplasia in 12 rats, schwannomas in five rats, and a sarcoma in one rat. One of the 12 rats with endocardial hyperplasia also had an intramural schwannoma. Of 200 Wistar rats given N-nitroso-N-methylurca, two had endocardial hyperplasia, and one had an endocardial schwannoma, Morphologic features were similar in either spontaneous or ireatment-associated hyperplasia or neoplasia of the rat endocardium. Probable Schwann cell origin of the endocardial proliferative lesions was indicated by positive immunohistochemical staining for S-100 antigen in 10/12 spontaneous and 11/14 careinogen-associated endocardial hyperplastic lesions. Further, 15/16 spontaneous and 6/7 carcinogen-associated neoplasms were immunoreactive to S-100. No tumor metastasis was recorded in either the spontaneously affected or carcinogen-treated rats.
An Immunohistochemical Study of the Pneumonia Caused by Peste des Petits Ruminants Virus
Authors: Brown C. C. , Mariner J. C. , Olander H. J.
Published: March 2010

Ten goats were inoculated with peste des petits ruminants virus, a paramyxovirus closely related to rinderpest virus. All goats developed severe clinical disease, 8/10 having coughing or dyspnea as prominent clinical signs. In addition, all of the goats had stomatitis and diarrhea. Histopathologic and immunohistochemical studies were done only on the respiratory tracts. Pathologic changes ranged from mild multifocal bronchiolitis and bronchitis to severe bronchointerstitial pneumonia. Lesions were more severe in anteroventral than caudal lobes. The histologic nature of the viral process in the goat lungs had many features in common with the processes of pneumonia in dogs, due to canine distemper, or pneumonia in human beings, due to measles virus. Immunohistochemical staining of formalin-fixed, paraffin-embedded respiratory tract tissue was performed using an indirect system with rabbit anti-rinderpest virus serum, biotinylated anti-rabbit antibody, streptavidin-alkaline phosphatase, and nitroblue tetrazolium chromogen. Staining was sensitive, highlighting the presence of viral antigen in both lung and trachea of all goats. Viral antigen was found in both cytoplasm and nucleus of tracheal, bronchial, and bronchiolar epithelial cells, type II pneumocytes, syncytial cells, and alveolar macrophages. In general, the amount of staining correlated directly with the severity of the inflammatory process.
Skeletal Muscle Rhabdomyosarcomas in Inbred Laboratory Mice
Authors: Sundberg J. P. , Adkison D. L. , Bedigian H. G.
Published: March 2010

A total of 14 well differentiated rhabdomyosarcomas were diagnosed at necropsy in 10,000 mice. Of the 14 affected mice, ten were BALB/cJ, and there was one case each of A/HeJ, BALB/cByJ, C58/J, and C.B-17- scid/scid strains. Most often (10/14) tumors originated in the quadriceps muscles and metastases occurred in six cases. When submitted, affected mice were 2 to 8 months of age, with a mean age of 4 months. Tumor frequency for BALB/cJ mice was calculated to be 2.4/100,000 mice retained as breeders. No sexual dimorphisms were determined when data were correlated to actual numbers of each sex in the colony. All 14 primary tumors and metastases were positive by immunohistochemistry for the proteins pan myosin, sarcomeric actin, desmin, actin, and myosin, but were negative for smooth muscle actin, thus confirming the diagnosis. Using cell free homogenates of primary tumors, inoculated by intraperitoneal or intramuscular injection, tumors were not induced in either BALB/cJ or C58/J mice observed over a 22-week period. Southern blot analysis of DNA prepared from tumors and hybridized with a murine leukemia virus probe that recognizes both ecotropic and dualtropic viruses did not demonstrate viral genomic fragments in addition to those known to occur in each strain.
Actin Filament Alterations in Rat Hepatocytes Induced In Vivo and In Vitro by Microcystin-LR, a Hepatotoxin from the Blue-green Alga, Microcystis aeruginosa
Authors: Hooser S. B. , Beasley V. R. , Waite L. L. , Kuhlenschmidt M. S. , Carmichael W. W. , Haschek W. M.
Published: March 2010

The morphologic effects of microcystin-LR (MCLR) were examined in vitro and in vivo to identify the specific cell type(s) affected and to characterize the actin filament changes occurring in hepatocytes. Male Sprague Dawley rats were used for all studies. For in vitro studies, hepatic cells were isolated by collagenase perfusion of liver, while parenchymal cells (hepatocytes) and nonparenchymal cells were prepared by pronase digestion and metrimazide gradient centrifugation. Cell suspensions and primary hepatocyte monolayer cultures were treated with MCLR at doses up to 10 μg/ml; cultured hepatocytes were also treated with phalloidin or cytochalasin B at a dose of 10 μg/ml; and rats were treated intraperitoneally with MCLR at 180 mg/kg. Cultured hepatocyte preparations and frozen liver sections were stained with rhodamine-labeled phalloidin for filamentous actin. In cell suspensions. MCLR did not affect nonparenchymal cells but caused rapid, progressive, blebbing of the plasma membrane in hepatocytes. In cultured hepatocytes, MCLR caused plasma membrane blebbing as well as marked reorganization of actin microfilaments. These alterations were dose and time dependent. Cultured hepatocytes treated with phalloidin or cytochalasin B also showed extensive plasma membrane blebbing and actin filament alterations; however, actin filament changes were morphologically distinct from those induced by MCLR. In vivo, MCLR-induced hepatocyte actin alterations occurred at the same time as, or slightly preceded, histologic changes that began 30 minutes after dosing. These studies suggest that early MCLR-induced morphologic changes occurring both in vivo and in vitro are due to alterations in hepatocyte actin filaments.
Alterations in Pulmonary Morphology and Peripheral Coagulation Profiles Caused by Intratracheal Inoculation of Live and Ultraviolet Light-killedPasteurella haemolyticaA1 in Calves
Authors: Whiteley L. O. , Maheswaran S. K. , Weiss D. J. , Ames T. R.
Published: March 2010

Eighteen male Holstein calves were divided into groups of three and inoculated intratracheally with 5 x 109logarithmic phase or ultraviolet light-killed Pasteurella haemolytica biotype A serotype 1. Serial coagulation profiles were done on one calf from each group during the first 24 hours after inoculation. One calf from each group was necropsied at 4, 12, and 24 hours after inoculation and lesions were characterized with light and transmission electron microscopy. We found that 1) the pulmonary intravascular macrophage may have an important role in the early intravascular inflammatory events; 2) there was morphologic evidence for local initation of the coagulation cascade in the lung early in the disease process but it was not a consumptive process; and 3) killed-bacteria were capable of causing fibrin exudation, platelet aggregation and alveolar epithelial damage similar to live bacteria, but the degenerative changes in neutrophils, endothelial cells and intravascular fibrin formation that occur with live bacteria were not seen.
Ganglioneuromas of the Thyroid Gland in a Colony of Sprague-Dawley Rats
Authors: Crissman J. W. , Valerio M. G. , Asiedu S. A. , Evangelista-Sobel I.
Published: March 2010

Ganglioneuromas of the thyroid gland of Sprague-Dawley rats were found in 7.2% of 698 rats used in two, 2-year oncogenicity bioassays. The incidence of the tumor was unrelated to treatment or sex. Of the 52 ganglioneuromas of the thyroid gland identified in 50 animals, 40 (80%) had coincident C cell proliferations in the same or contralateral lobe. Ganglioneuromas were contiguous or commingled with C cell proliferations in 63.5% of the cases. The ganglioneuromas consisted of large ganglion cells and, in a few cases, cells thought to be less differentiated neuronal precursors, in a matrix of neurites and Schwann cells. They grew, infiltrating and expanding in the thyroid parenchyma, and did not metastasize. Immunohistochemical staining for calcitonin, S-100 protein, and neurofilaments, as well as electron microscopy, were used to further characterize the tumors. The close association of ganglioneuromas with C cell tumors supports the theory of neural crest origin of C cells and provides a parallel to the association of ganglioneuromas and pheochromocytomas in the adrenal medulla. This is the first report of ganglioneuromas occurring in the thyroid gland or occurring as a common entity in any species.
Spontaneous Amelanotic Melanomas of the Uveal Tract in F344 Rats
Authors: Yoshitomi K. , Boorman G. A.
Published: March 2010

Five intraocular amelanotic melanomas were identified in the National Toxicology Program's database consisting of records from more than 60.000 female and 60.000 male F344 rats, which were used as control and treated animals in 2-year carcinogenicity studies. The five spontaneous melanomas were grossly observed as white or yellow, unilateral nodules, which originated in the region of the iris and ciliary body, often also involving the choroid. These amelanotic melanomas were composed predominantly of spindle cells arranged in a whorled pattern often with perivascular orientation. Mitotic figures were common in five tumors. The spindle cells had a positive immunoreactivity for S-100 protein but were negative for desmin. Electron microscopic studies provided clear evidence that these tumors originated from the uveal melanocytes. Ultrastructurally, the spindle cells contained numerous cytoplasmic premelanosomes (stage II melanosomes) that were not associated with melanin. Special histochemical studies showed that the spindle cells had a negative reaction for melanin. Although electron microscopic features are critical in the diagnosis of amelanotic melanomas of the uveal tract, the whorled pattern of spindle cells is a useful histologic criterion in differential diagnosis of this tumor in F344 rats.
Heterophil Function in Healthy Chickens and in Chickens with Experimentally Induced Staphylococcal Tenosynovitis
Authors: Andreasen C. B. , Latimer K. S. , Harmon B. G. , Glisson J. R. , Golden J. M. , Brown J.
Published: March 2010

Heterophil function was evaluated in 16 healthy chickens and in 46 chickens with experimentally induced staphylococcal tenosynovitis. In paired blood samples, heterophils from chickens with tenosynovitis had a significant increase in adherence, chemotaxis, phagocytosis, and bacterial killing of Staphylococcus aureus compared to heterophils from healthy chickens. The percent adherence of heterophils to nylon fiber columns increased significantly from a 78.4% mean ± 6.6% standard deviation to 87.6% ± 3.2% after induction of staphylococcal tenosynovitis. Heterophil movement following in vitro exposure to saline or endotoxin was increased in chickens with tenosynovitis; 3 ± 1 heterophils/0.25 mm2to 10 ± 6 heterophils/0.25 mm2and 136 ± 29 heterophils/0.25 mm2to 340 ± 74 heterophils/0.25 mm2, respectively. Endotoxin-activated serum was chemoattractive for heterophils from all chickens. Flow cytometry was used to define the heterophil population on light scatter histograms, evaluate individual cell phagocytosis of latex beads, and quantitate the number of beads phagocytosed per heterophil. When incubated with increased numbers of beads, only heterophils from chickens with tenosynovitis phagocytosed higher numbers of beads. At heterophil to bead ratios of 1:10, the percentage of heterophils that phagocytosed beads increased from baseline values of 37.8% ± 9.0% to postinfection values of 67.3% ± 7.5%. Using 1:20 heterophil to bead ratios, heterophil phagocytosis increased from 38.7% ± 9.9% to post-infection values of 79.8% ± 7.3%. Heterophils from all chickens were able to phagocytose and kill log phase staphylococcal bacteria. After phagocytosis, the heterophils from chickens with staphylococcal tenosynovitis rapidly decreased the number of viable bacterial colony forming-units per milliliter by approximately one log. Circulating heterophils from chickens with experimentally induced staphylococcal tenosynovitis therefore appear to have increased functional capabilities in this bacterial inflammatory disease.
Effects of 4-Ipomeanol on Bovine Parainfluenza Type 3 Virus-induced Pneumonia in Calves
Authors: Li X. , Castleman W. L.
Published: March 2010

Previous research has demonstrated that 4-ipomeanol toxicosis can enhance the severity of parainfluenza virus-induced pneumonia in mice. The objectives of this study were to determine whether calves are susceptible to 4-ipomeanol-induced enhancement of parainfluenza type 3 viral pneumonia and to determine whether 4-ipomeanol alters pulmonary replication of parainfluenza virus. Male Holstein calves were injected with either 4-ipomeanol (3 mg/kg) or vehicle (polyethylene glycol) 3 days prior to intratracheal inoculation with either parainfluenza virus or sham inoculum of culture medium. Calves in the four treatment groups (ipomeanolparainfluenza, ipomeanol-medium, vehicle-parainfluenza, and vehicle-medium) were necropsied at 5 days after inoculation with parainfluenza virus or medium. The lungs were studied by correlated methods of light and electron microscopy, digitizing morphometry and pulmonary lavage to quanlitate the severity of pneumonia. Pulmonary viral titers were determined, and viral antigen was identified in the lung by immunoperoxidase technique. The calves in the ipomeanol-virus treatment group had over a 9-fold higher ( P < 0.05) volume density of virus-induced interstitial pneumonia than did the calves in the other three treatment groups. This 4-ipomcanol-enhanced viral pneumonia was associated with significantly greater ( P < 0.05) numbers of pulmonary macrophages and neutrophils in the lavage fluid and higher ( P < 0.05) pulmonary titers of pulmonary infectious parainfluenza virus. Four-ipomeanol-enhanced viral pneumonia was characterized in part by extensive hyperplasia of type II alveolar epithelial cells and by dense aggregates of macrophages and neutrophils in alveolar spaces and interalveolar septa. The results indicate that 4-ipomeanol exacerbates interstitial pneumonia in calves induced by bovine parainfluenza type 3 virus.
Bovine Undifferentiated Alveolar Rhabdomyosarcoma and its Differentiation in Xenotransplanted Tumors
Authors: Matsui T. , Imai T. , Han J. S. , Awakura T. , Taniyama H. , Osame S. , Nakagawa M. , Ono T.
Published: March 2010

At necropsy, a 7-year-old Holstein cow, clinically diagnosed via rectal palpation as having malignant abdominal neoplasia was found to have many metastatic tumors of various sizes in the abdominal and thoracic cavities and in the liver, lung, kidney, adrenal, uterus, and lymph nodes. These tumors were examined by histologic and immunohistochemical methods using anti-human myoglobin, anti-bovine myoglobin, and anti-desmin sera. Tumors were diagnosed as undifferentiated alveolar rhabdomyosarcomas. The tumors in the abdominal and thoracic cavities differed histologically from the metastases in organs. The former tumors consisted of only undifferentiated cells, most of which did not stain positively for desmin or myoglobin. The metastatic tumors contained a few rhabdomyoblastic cells that stained positively for desmin and myoglobin. Tumor tissues from the cow were transplanted and propagated through six passages in athymic nude mice. After one passage, the transplanted tumor histologically resembled those from the abdominal serosa and consisted of cells with scanty cytoplasm with an alveolar arrangement. Cells from this tumor stained positively for desmin and negatively for myoglobin. After two passages through nude mice, tumor cells were of two distinct histologic types: those cells with scanty cytoplasm and elongated cells with plentiful eosinophilic cytoplasm. Both of these cells stained positively for both desmin and myoglobin. After six passages, cross striations were detected in neoplastic cells by electron microscopy. These findings illustrate that a highly undifferentiated bovine rhabdomyosarcoma, in which most of the cells in the original tumor lacked desmin and myoglobin, became better differentiated and stained positively for desmin and myoglobin after serial transplantation in nude mice.
Intraocular and Orbital Malignant Schwannomas in F344 Rats
Authors: Yoshitomi K. , Boorman G. A.
Published: March 2010

Intraocular and orbital malignant Schwannomas in two F344 rats are presented. The two Schwannomas were identified among approximately 60,000 male and 60,000 female F344 rats. The intraocular malignant Schwannoma occurred in the iris, invading the corneal stroma through the destroyed Descemet membrane. The malignant orbital Schwannoma occurred in the left orbit, invading the contralateral orbit along the optic nerve. Histologically, the intraocular Schwannoma consisted predominantly of a perivascular fascicular pattern of plump spindle cells associated with marked cytoplasmic vacuolization. The orbital Schwannoma consisted of Antoni type A and B pattern, but Antoni B tissues predominated. Antoni A tissues consisted of closely packed, elongated spindle cells arranged in interlacing fascicles, while Antoni B tissues were highly cellular and consisted of anaplastic, small cells associated with marked cyst formation. Immunohistochemically, the intraocular Schwannoma had a positive immunoreactivity for S-100 protein, while the orbital Schwannoma had a negative immunoreactivity. Ultrastructurally, the cells of both intraocular and orbital Schwannomas had long, thin cell processes and pericytoplasmic basal laminae. Particularly, the plump spindle cells of the intraocular Schwannoma were most strikingly characterized by the well developed, extremely attenuated cell processes arranged in a lamellar or spiral pattern. These cell processes and cell bodies were associated with numerous desmosomes. Intracytoplasmic filamentous granules and bodies, consisting of intermediate filaments approximately 7 nm in width, were additional characteristics of the plump spindle cells.
Brucella abortus-associated Meningitis in Aborted Bovine Fetuses
Authors: Hong C. B. , Donahue J. M. , Giles R. C. , Poonacha K. B. , Tuttle P. A. , Cheville N. F.
Published: March 2010

Granulomatous meningitis was present in 6/33 bovine fetuses from which Brucella abortus ( B. abortus) had been isolated. Meningitis was severe in three fetuses, moderate in one fetus, and mild in the remaining two fetuses. The meningitis was characterized by the infiltration of a mixed population of lymphocytes, plasma cells, and macrophages in the leptomeninges. Vasculitis characterized by the infiltration of lymphocytes and plasma cells in the vascular wall was observed in the vessels of the cerebral cortices of 4/6 fetuses. Gram negative coccobacilli were present in the cytoplasm of the leptomeningeal macrophages and extracellularly. Brucellar antigens labeled by the avidin-biotin-peroxidase complex method were present in massive amounts in leptomeningeal macrophages and in small foci of stained cells in the choroid plexus and ependyma. The findings indicate that B. abortus is one of pathogens capable of inducing meningitis in bovine fetuses.
Lentivirus-induced Pulmonary Lesions in Rhesus Monkeys (Macaca mulatta) Infected with Simian Immunodeficiency Virus
Authors: Baskin G. B. , Murphey-Corb M. , Martin L. N. , Soike K. F. , Hu F-S , Kuebler D.
Published: March 2010

Necropsy reports from 28 rhesus monkeys that had been experimentally infected with simian immunodeficiency virus (SIV) and that were free of cytomegalovirus were reviewed. Lung sections from 24 of these monkeys that had no etiologic agent other than SIV detected in the lung were studied in detail by histopathologic, immunohistochemical, and electron microscopic examination and by in situ hybridization. Fourteen of the monkeys were part of a serial euthanasia study, while others were euthanatized after they became moribund. The following lesions were detected: perivascular inflammation, vasculitis, interstitial pneumonia, syncytial cells, hemorrhage, fibrin exudation, and pleural fibrosis. Perivascular inflammation was the most frequent lesion and occurred as early as 2 weeks after inoculation. Severe pneumonia and numerous syncytial cells were seen only in animals euthanatized because they had become moribund. The lesions appeared to be directly due to SIV infection. SIV antigens, RNA, and virions were detected in syncytial cells and macrophages by immunohistochemical examination, in situ hybridization, and transmission electron microscopic examination, respectively. The amount of virus present was correlated with the severity of the lesions. The SIV-induced lesions were different from those of the lymphocytic interstitial pneumonia, which occurs in human immunodeficiency virus-infected children and in ovine lentivirus-infected sheep and goats.
Cytokine Modulation of the Interaction Between Bluetongue Virus and Endothelial Cells in vitro
Authors: Coen M. L. , Ellis J. A. , O'Toole D. T. , Wilson W. C.
Published: March 2010

An in vitro model was developed to examine the interaction between endothelial cells and the host inflammatory response in bluetongue virus (BTV) infections. Whole cell enzyme-linked immunosorbent assays, a tritiated thymidine uptake assay, and a colorimetric assay of mitochondrial function were used to assess how four cytokines (interleukin-1, interleukin-2, interferon-gamma, and tumor necrosis factor-alpha) affect endothelial cell metabolism and susceptibility to BTV infection. Concurrent alterations in major histocompatibility complex (MHC) antigen expression were also examined. BTV infection suppressed target cell mitochondrial function and DNA synthesis and enhanced MHC class I expression. Interferon-gamma and tumor necrosis factor alpha suppressed viral antigen expression and were synergistic early in the infection. Interferon gamma enhanced MHC class I and induced MHC class II antigen expression in both BTV infected and uninfected endothelial cells. The other cytokines had minimal effect on endothelial cell surface antigen expression, although interleukin-1 (IL-1) did inhibit cell growth. Infected endothelial cell cultures produced interferon at 20 hours and 40 hours after infection. Electron microscopic analysis confirmed previous findings in other cell lines regarding BTV morphogenesis in endothelial cells, the putative target cell population in vivo.
Toxicosis in Sheep Following Ingestion of Natural Gas Condensate
Authors: Adler R. , Boermans H. J. , Moulton J. E. , Moore D. A.
Published: March 2010

Thirty of 200 ewes died or were euthanatized during a 21-day period following a 1-day accidental exposure to natural gas condensate, a complex mixture of hydrocarbons obtained during collection of natural gas from wells. Despite access to potable well water, the poisoned ewes willingly consumed toxic doses of condensate that contaminated surface water. Eight animals died without premonitory signs; the remainder became ill over the course of a few days to 3 weeks. The principal cause of mortality was aspiration pneumonia, but myocardial degeneration and necrosis, renal tubular damage, gastritis, enteritis, and meningeal edema and hyperemia were also observed. Gas chromatographic analysis identified chemical traces of the hydrocarbons in the tissues, and “fingerprinting,” the process of matching chromatographic tracings, provided forensic proof of the contamination source. Atomic absorption spectroscopy and cholinesterase analyses were performed to eliminate the possibility of toxicosis by heavy metal contaminants or other constituents. This appears to be the first reported incidence of natural gas condensate toxicity involving sheep or other ruminants. Although the available literature presents a suggestive pattern of clinical signs and pathologic lesions of petroleum product poisoning, diagnostic investigations should employ detailed analytic examination because each source of petroleum hydrocarbons contains unique sets of components that may produce different toxic effects.
Eosinophilic Gastroenteritis with Splendore-Hoeppli Material in the Ferret (Mustela putorius furo)
Authors: Fox J. G. , Palley L. S. , Rose R.
Published: March 2010

Eosinophilic gastroenteritis, focal or diffuse with eosinophilic infiltrations of the stomach or intestine, has been described in human beings, cats, dogs, and horses. In this paper, we describe infiltration of the gastrointestinal tract with eosinophils accompanied by a circulating eosinophilia in six ferrets ( Mustela putorius furo). Clinical signs included chronic weight loss, anorexia, and diarrhea. The small intestines from five ferrets had diffuse infiltrates of eosinophils. This resulted in focal or multifocal loss of the muscular tunic in three ferrets. Two of these ferrets also had eosinophilic gastritis. Eosinophilic granulomas with Splendore-Hoeppli material were present in mesenteric lymph nodes in four ferrets. Two ferrets had multiple organ involvement; one had eosinophilic granulomas in the liver, mesentery, and choroid plexus as well as moderate parapancreatic segmental arteritis with infiltration of eosinophils and mural thrombosis. The second ferret had, in addition to moderate diffuse gastric and small intestinal eosinophilic mucosal infiltrations, interstitial eosinophilic pulmonary infiltrates. Examination of all tissues failed to reveal an infectious agent.
Monoclonal Antibody-based Immunohistochemical Detection of Bovine Viral Diarrhea Virus in Formalin-fixed, Paraffin-embedded Tissues
Authors: Haines D. M. , Clark E. G. , Dubovi E. J.
Published: March 2010

Thirty-two monoclonal antibodies directed against epitopes on bovine viral diarrhea virus proteins and glycoproteins were tested for immunohistochemical reactivity with bovine viral diarrhea virus in formalin-fixed and paraffin-embedded tissues from 45 cases of bovine viral diarrhea virus-associated mucosal disease. Only one antibody, designated 15C5, which reacts with the 48-kD glycoprotein of bovine viral diarrhea virus, detected an epitope preserved in these specimens. Monoclonal antibody 15C5 and a polyclonal antibody to bovine viral diarrhea virus successfully detected bovine viral diarrhea viral antigens in 44/45 cases of mucosal disease and did not react with formalin-fixed tissues from 30 uninfected cattle. Monoclonal antibody-based immunohistochemical detection of bovine viral diarrhea virus in routinely fixed tissue specimens has advantages over other currently available techniques in terms of the convenience of specimen submission, the relative ease of method standardization, and the rapidity of the test, and by enabling identification of the virus in association with specific tissues, cell types, and histologic lesions.
Uptake of Ferritin by Follicle-associated Epithelium in the Colon of Calves
Authors: Paar M. , Liebler E. M. , Pohlenz J. F.
Published: March 2010

Uptake of macromolecules (e.g., ferritin) by M cells in follicle-associated epithelium in small and large intestine was investigated in three healthy, conventionally raised, 2- to 3-week-old, female Holstein Frisian calves. A 2.5% solution of ferritin was injected into the ligated loops in mid-jejunum, in terminal ileum, in the ascending colon adjacent to the ileocecal junction, and in the proximal loop of the ascending colon containing gut-associated lymphoid tissue. After exposure times that ranged from 82 to 165 minutes, ferritin was detected in M cells of domes in the small intestine, as well as in cells in follicle-associated epithelium of proprial lymphoid nodules and lymphoglandular complexes of colon that morphologically resembled M cells of small intestine. Ferritin was found in apical invaginations, apical vesicles, multivesicular bodies, basal vesicles, and adjacent intercellular spaces. In addition to ferritin, apical vesicles, multivesicular bodies, and intercellular spaces contained 50-nm membrane-bound particles. More ferritin was endocytosed by M cells of the small intestine than by M cells of the large intestine. In the large intestine, higher amounts of ferritin were found in M cells of follicle-associated epithelium overlying proprial lymphoid nodules than in M cells of follicle-associated epithelium in the depth of lymphoglandular complexes. Based on these results, we concluded that M cells of follicle-associated epithelium in the colon of calves provide a route for antigen uptake into the intestinal lymphoid system.
Toxic Peripheral Neuropathy with Demyelination in Sprague-Dawley Rats Given CGS 21595 —A 5-Lipoxygenase Inhibitor
Authors: Gunson D. E. , Sahota P. S. , Iverson W. O. , Chau R. Y. , McCormick G. M. , Traina V. M.
Published: March 2010

Male and female Sprague-Dawley rats were given CGS 21595, a pro-drug that is almost immediately metabolized to CGS 19213, a naphthoquinone that acts as a 5-lipoxygenase inhibitor. The compound was administered by gavage to five groups of Sprague-Dawley rats (group Nos. 1, 5, n = 30; group Nos. 2–4, n = 20) at daily doses of 0, 50, 150, 500, or 1,000 mg/kg for 13 weeks. Rats in the higher dose groups had a reduced weight gain, but significant neurologic signs were not observed. A peripheral neuropathy consisting predominantly of myelin destruction in the spinal nerve roots and sciatic nerves was seen in male rats treated with ≥ 150 mg/kg CGS 21595 and in female rats treated with ≥50 mg/kg CGS 21595 for 13 weeks. This lesion was not fully reversible after a recovery period of 4 weeks. Lesions consisted of ballooning of myelin sheaths, infiltration by macrophages, demyelination, and occasional areas of remyelination. Axons were generally preserved, and the brain and spinal cord were not affected. Male and female rats in all treatment groups had cytoplasmic hyaline droplets in the proximal renal tubules. This change was reversible after 4 weeks and was not associated with any other adverse effects on the kidney.
Transplantation of Large Granular Lymphocyte Leukemia in Congenitally Athymic Rats
Authors: Stromberg P. C. , Rosol T. J. , Grants I. S. , Mezza L. E.
Published: March 2010

Twenty-two congenitally athymic nude ( rnu/rnu) rats were transplanted with large granular lymphocyte leukemia derived from F344 rats and then compared with ten similar rats inoculated with a suspension of normal F344 rat spleen cells. The normal spleen cells and tumor cells from a spontaneous, naturally occurring leukemia did not grow or cause clinical disease in any of the rats. All rats inoculated with a serially passaged leukemia cell inoculum had local growth at the inoculation site that spread widely and resulted in progressive tumor growth. Death occurred between 16 and 38 days after inoculation. The 22 rats that received passaged tumor cells developed leukemia and splenomegaly. Spleens were diffusely infiltrated by tumor cells and had severe depletion of lymphocytes in the white pulp. Leukemic rats were thrombocytopenic and had hemolytic anemia characterized by increased osmotic fragility, red cell width, and many nucleated erythrocytes. The disease syndrome appears similar to that of F344 rats transplanted with the same inoculum. Because the host rats lacked T cells, it is concluded that the hemolytic anemia and thrombocytopenia that develop in transplanted rats are independent of T cell function.
Ultrastructural Changes in Articular Cartilages of Immature Beagle Dogs Dosed with Difloxacin, a Fluoroquinolone
Authors: Burkhardt J. E. , Hill M. A. , Turek J. J. , Carlton W. W.
Published: March 2010

The ultrastructural features of quinolone-induced arthropathy were studied in' the humeral and femoral heads of nine skeletally immature Beagle dogs (3 months old) that were dosed orally with difloxacin at 300 mg/kg body weight and euthanatized 24, 36, or 48 hours later in groups of three. Three age-matched dogs were given a placebo and euthanatized after 48 hours. Mitochondria in chondrocytes had significantly greater cross-sectional areas ( P < 0.05) in electron micrographs from dogs euthanatized after 48 hours of treatment than did those in other groups. There was also a significantly greater percentage of chondrocytes with swollen mitochondria in treated dogs than in the controls ( P < 0.05). These changes preceded the necrosis observed in some chondrocytes in the dogs of the 48-hour group. Disruption of extracellular matrix was first observed in the pericellular matrix of necrotic chondrocytes, indicating that this change was secondary to the changes in chondrocytes. Fissures within cartilages apparently resulted from the loss of the normal association of proteoglycans with collagen fibrils.
Microscopic and Ultrastructural Studies of Necrotizing Hepatopancreatitis in Pacific White Shrimp (Penaeus vannamei) Cultured in Texas
Authors: Frelier P. F. , Sis R. F. , Bell T. A. , Lewis D. H.
Published: March 2010

Granulomatous hepatopancreatitis of unknown etiology has been considered an important disease of Texas shrimp mariculture since 1985. Samples of Pacific white shrimp ( Penaeus vannamei) were collected during 1986, 1987, and 1990 from three farms and an experimental mariculture facility with histories of production loss and increased mortality rates. Histologic and ultrastructural examination of shrimp from the four sites demonstrated two morphologically distinct, Gram-negative, double-enveloped, intracytoplasmic bacteria in necrotic hepatopancreatic epithelium. The more numerous small, pleomorphic rod as well as the helical organism are both taxonomically unclassifiable. The helical organism lacked ultrastructural characteristics of previously described helical or spiral bacteria. The relationship between the two organisms is unknown, but the pleomorphic rod is thought to play a major role in the disease. The role of a bacterial agent(s) in subsequent disease episodes is suggested by the observation that the use of oxytetracycline-medicated feed resulted in increased production and survival. Hepatopancreatic tubular epithelial necrosis and shrimp mortality correlated directly with the extent of infection by the small pleomorphic rod. Individual discrete bacteria were identified microscopically by Steiner and Steiner's method. Three major developmental stages of the disease were characterized based on the extent and number of hepatopancreatic tubular epithelial cells containing bacteria, the degree of tubular interstitial inflammation, and the extent and chronicity of tubular necrosis. Additional studies are needed to clarify the roles of the different bacteria identified and the potential role of environmental factors on the disease process.
Brain Lesions of Naturally Occurring Pregnancy Toxemia of Sheep
Authors: Jeffrey M. , Higgins R. J.
Published: March 2010

The neuropathology and biochemical features of 17 sheep with clinical signs and gross necropsy features of naturally occurring pregnancy toxemia were retrospectively evaluated. The sheep ranged in age from 3 to 6 years and were of seven different breeds and three breed crosses. Thirteen sheep (case Nos. 1–4, 6–9, 11–14, 16) showed astrocytic nuclear swelling, hypertrophy and proliferation, and cerebrocortical neuronal necrosis. Seven of these sheep had Purkinje cell necrosis (case Nos. 2, 3, 6, 11, 12, 14, 16), and seven had vacuolation of cerebral and cerebellar sub-cortical white matter (case Nos. 1–4, 9, 12, 13). The neuropathologic features were similar to those of naturally occurring hypoglycemia of human beings and experimentally induced hypoglycemia of primates and the rat. The lesions seen in the sheep studied may have been caused by cerebral hypoglycemia, but data for blood or cerebral glucose concentrations were not available.
Effects of Humoral Hypercalcemia of Malignancy on the Parathyroid Gland in Nude Mice
Authors: Gröne A. , Rosol T. J. , Baumgärtner W. , Capen C. C.
Published: March 2010

The ultrastructure of parathyroid chief cells was examined from four groups of nude mice (NIH: Swiss) with different serum calcium concentrations. The groups consisted of eight male mice with hypercalcemia induced by transplantable canine adenocarcinoma (CAC-8), eight female mice with hypercalcemia induced by infusion of parathyroid hormone-related protein, ten male control mice, and six male mice fed a low calcium (0.01%) diet. Hypercalcemia induced by malignancy or parathyroid hormone-related protein infusion was associated with low serum phosphorus concentration, a decrease in the number of secretory and prosecretory granules in the parathyroid chief cells, and an increase in the cytoplasmic area of chief cells. Prominent myelinlike membranous whorls were present in the cytoplasm of chief cells of tumor-bearing and parathyroid hormone-related protein-infused hypercalcemic mice. Mice fed a low calcium diet had decreases in the number of secretory granules and cell area but increases in the number of prosecretory granules compared with control mice. The number of mitochondria and the nuclear area of chief cells were similar in all four groups. The prominent membranous whorls and increased cytoplasmic area of chief cells from these hypercalcemic mice mark these cells as distinctly different from the parathyroid chief cells of other species with hypercalcemia.
Hematologic Features of Iron Deficiency Anemia in Llamas
Authors: Morin D. E. , Garry F. B. , Weiser M. G. , Fettman M. J. , Johnson L. W.
Published: March 2010

Iron deficiency anemia was identified and characterized in three 14 to 29-month-old male llamas (llama Nos. 1–3) from separate herds in Colorado. The identification of iron deficiency anemia was based on hypoferremia (serum iron = 20–60 μg/dl), erythrocytic features, and hematologic response to iron therapy. The anemia was moderate and nonregenerative and characterized by erythrocyte hypochromia, microcytosis (mean cell volume = 15–18 fl), and decreased mean corpuscular hemoglobin concentration (36.0–41.0 g/dl). Morphologic features unique to llamas with iron deficiency anemia included irregular distribution of hypochromia within erythrocytes and increased folded cells and dacryocytes. The cause of iron deficiency was not determined. The llamas were treated with various doses and schedules of parenteral iron dextran. Two of the llamas were monitored for up to 14 months after the start of iron therapy and experienced increases in hematocrit and mean cell volume values. In one llama, progressive replacement of microcytic cells with normal cells was visualized on sequential erythrocyte volume distribution histograms following iron therapy.