bluuebunny/crossref_metadata_2025 huggingface dataset:
Enforcing Network Connectivity in Robot Team Missions
Authors: Tardioli D. , Mosteo A.R. , Riazuelo L. , Villarroel J.L. , Montano L.
Published: January 2010

The growing interest in robot teams for surveillance or rescue missions entails new technological challenges. Robots have to move to complete their tasks while maintaining communication among themselves and with their human operators, in many cases without the aid of a communication infrastructure. Guaranteeing connectivity enables robots to explicitly exchange information needed in collaborative task execution, and allows operators to monitor or manually control any robot at all times. Network paths should be multi-hop, so as not to unnecessarily restrict the team’s range. In this work we contribute a complete system which integrates three research aspects, usually studied separately, to achieve these characteristics: a multi-robot cooperative motion control technique based on a virtual spring—damper model which prevents communication network splits, a task allocation algorithm that takes advantage of network link information in order to ensure autonomous mission completion, and a network layer which works over wireless 802.11 devices, capable of sustaining hard real-time traffic and changing topologies. Link quality among peers is the key metric used to cooperatively move the robots and maintain uninterrupted connectivity, and the basis for novel ideas presented in each subsystem. Simulations and experimental results with real robots are presented and discussed.
Myopathy and Encephalopathy in Chick Embryos Experimentally Infected with Akabane Virusg
Authors: Konno S. , Koeda T. , Madarame H. , Ikeda S. , Sasaki T. , Satoh H. , Nakano K.
Published: January 2010

Chick embryos infected with Akabane virus by the yolk sac route at 6 days of incubation developed polymyositis and encephalitis. At 3 to 7 days after inoculation, skeletal muscles had myotubule degeneration, clumping of muscle cell nuclei, and infiltration of heterophils; dysplasia and aplasia were evident at 9 to 15 days after inoculation. Changes in the cerebral neostriatum and optic lobes at 2 to 11 days after inoculation included necrosis of primordial nervous tissue, hemorrhages, and hyperplasia of the vascular endothelial cells. Cavities were in nervous tissue subsequent to encephalitis. Hydranencephaly and vascular wall thickening were found 13 and 15 days after inoculation. Embryos infected intravenously at 15 days incubation had foci of encephalitis 3 to 6 days after inoculation, including neuronal degeneration, neuroglial hyperplasia, vascular endothelial proliferation, and heterophil infiltration.
Peripheral Neuropathy Associated with Dietary Riboflavin Deficiency in the Chicken I. Light Microscopic Study
Authors: Johnson W. D. , Storts R. W.
Published: January 2010

Chickens fed a riboflavin-deficient diet from hatching had leg weakness and paralysis as early as 12 days of age. Signs worsened through day 16; after 35 days, recovery was evident. Sciatic nerves from affected chickens were enlarged. Significant microscopic lesions were confined to peripheral nerves and included tissue separation (suggesting interstitial edema), Schwann cell swelling, perivascular leukocytic infiltration, and segmental demyelination accompanied by accumulation of osmiophilic debris in Schwann cell cytoplasm. Axon degeneration was present, but was not a primary lesion. Acid phosphatase enzyme activity of Schwann cells was increased in affected nerves. These results demonstrate that dietary riboflavin deficiency causes a demyelinating peripheral neuropathy in young, rapidly growing chickens.
Veno-occlusive Disease of the Liver in Captive Cheetah
Authors: Gosselin S. J. , Loudy D. L. , Tarr M. J. , Balistreri W. F. , Setchell K. D. R. , Johnston J. O. , Kramer L. W. , Dresser B. L.
Published: January 2010

Liver tissues from 126 captive cheetah were evaluated by light microscopy and histochemistry; eight animals were evaluated by electron microscopy. The main hepatic lesion, a vascular lesion resembling veno-occlusive disease (VOD) of the liver and characterized by subendothelial fibrosis and proliferation of smooth muscle-like cells in the central veins, was seen in 60% of the sexually mature cheetah. Although this hepatic vascular lesion was seen in cheetah as young as 1 year of age, the most severe lesions, usually associated with liver failure, were found in cheetah between the ages of 6 and 11. There was no sex predisposition, and in approximately 40% of the VOD cases, liver disease was not suspected clinically or at necropsy. VOD was found in other felidae, especially in the snow leopard. High levels of vitamin A in livers, as well as in diets of the cheetah, could be a contributing factor in the development of VOD in some groups of cheetah.
Role of M Cells and Macrophages in the Entrance of Mycobacterium paratuberculosis into Domes of Ileal Peyer's Patches in Calves
Authors: Momotani E. , Whipple D. L. , Thiermann A. B. , Cheville N. F.
Published: January 2010

Ligated ileal loops of calves were inoculated with live and heat-killed Mycobacterium paratuberculosis and were examined by light and electron microscopy. At 5 hours after inoculation, acid-fast bacilli were in subepithelial macrophages, but not in M cells covering domes. At 20 hours, more than 50 acid-fast bacilli per cross section were in subepithelial macrophages in domes. Both living and heat-killed bacilli passed into domes. Addition of anti- M. paratuberculosis bovine scrum to the inoculum enhanced entry of bacteria into domes. By electron microscopy, intact bacilli with electron-transparent zones (peribacillary spaces) were in the supranuclear cytoplasm of M cells at 20 hours. M cells also contained vacuoles, including electron-dense material interpreted as degraded bacilli. Subepithelial and intraepithelial macrophages contained bacilli and degraded bacterial material in phagosomes. These results suggest that calf ileal M cells take up bacilli, and that subepithelial and intraepithelial macrophages secondarily accept bacilli or bacterial debris which are expelled from M cells.
The Role of Proteases in 4-ipomeanol-induced Enhancement of Sendai Viral Pneumonia in Mice
Authors: Durham S. K. , Dubovi E. A. , Castleman W. L.
Published: January 2010

The ability of reconstituted, concentrated lyophilized lavage fluid to activate noninfectious Sendai virus (NISV) in vitro was examined. Lavage fluid was obtained from 4-ipomcanol (4-IP)-injured lungs at 1, 3, 5, 7, 9, and 13 days after treatment, and 1, 7, and 13 days after sham treatment (controls). Significantly higher viral titers were obtained using lavage fluid collected 1 day after 4-IP treatment. Higher protein concentrations were present in lavage fluid obtained at day 1 and 3 after 4-IP treatment. It is concluded that local viral-activating protease concentrations resulting from 4-IP-induced pulmonary injury is a likely microenvironmental modulator of paramyxoviral replication and can play an important role in paramyxoviral-induced lung injury.
Flow Cytofluorimetric Analysis of Lymphocyte Subset Alterations in Cattle Infected with Bovine Viral Diarrhea Virus
Authors: Ellis J. A. , Davis W. C. , Belden E. L. , Pratt D. L.
Published: January 2010

Clinically normal, bovine viral diarrhea virus (BVDV)-seronegative, 7 to 9-month-old steers were inoculated intranasally with NY-1. a noncytopathic strain of BVDV, or exposed intramuscularly to killed BVDV. Indirect immunofluorescence staining with monoclonal antibodies specific for bovine leukocyte subsets followed by flow cytometric analysis was used to monitor subsequent hematologic alterations. Infection with BVDV resulted in a transient leukopenia which was characterized by decreases in the absolute numbers of circulating T lymphocytes, including BoT4+ (“helper”) and BoT8+ (“cytotoxic/suppressor”) subsets, B lymphocytes, and neutrophils. There was no significant variation in numbers of non-T, non-B (“null”) lymphocytes or monocytes. Exposure to inactivated BVDV in a combination vaccine did not cause significant alteration in the circulating numbers of any major leukocyte subset; however, significant variation was seen in the BoT4/BoT8 ratios and in the numbers of cells expressing major histocompatibility complex (MHC) class II antigens.
Papillomas and Carcinomas Associated with a Papillomavirus in European Harvest Mice(Micromys minutus)
Authors: Sundberg J. P. , O'Banion M. K. , Shima A. , Knupp C. , Reichmann M. E.
Published: January 2010

Papillomaviruses, group-specific papillomavirus antigens, or extrachromosomal papillomavirus DNA were detected in cutaneous, mucocutaneous, and pulmonary tumors affecting a colony of European harvest mice (Micromys minutus). Skin lesions were classified as acanthomatous hyperplasia, epidermal inclusion cysts. squamous papillomas, inverted papillomas, trichoepitheliomas, and sebaceous carcinomas. Cutaneous horns (hyperkeratotic papillomas) were on mucocutaneous junctions of one animal. One mouse, with a cutaneous sebaceous carcinoma, had multiple pulmonary keratinaceous cysts. Papillomavirus antigens, detected by the avidin-biotin technique, were in 20 of 31 lesions tested. In contrast, by Southern blot hybridization all 28 lesions tested contained papillomavirus DNA. Papillomavirus DNA was demonstrated in two often benign cutaneous lesions by in situ hybridization.
Immunophenotype of Pulmonary Cellular Infiltrates in Sheep with Visceral Caseous Lymphadenitis
Authors: Ellis J. A.
Published: January 2010

Pulmonary lesions associated with Corynebacterium ovis were analyzed with an indirect immunoperoxidase staining technique using monoclonal antibodies. The predominant cells in abscess walls and surrounding lung parenchyma were large macrophages which expressed major histocompatibility complex (MHC) class II molecules on their surfaces. T lymphocytes were prominent in the same sites in the naturally occurring lesions, and SBU-T4-positivc (“helper/inducer”) cells were the major subset of lymphocytes (mean T4/T8 ratio = 3.5). B lymphocytes and granulocytes comprised minor populations of infiltrating cells. These results implicate activated macrophages and MHC class II-restricted T lymphocytes in the pathogenesis of established C. ovis infections in sheep.
Acute Fibrinopurulent Blepharitis and Conjunctivitis Associated with Staphylococcus hyicus, Escherichia coli, and Streptococcus sp. in Chickens and Turkeys
Authors: Cheville N. F. , Tappe J. , Ackermann M. , Jensen A.
Published: January 2010

Multiple outbreaks of acute severe fibrinopurulent lesions of the eyelids occurred in chickens and turkeys. Lesions began as tiny foci of epidermal necrosis and ulceration and spread to involve the entire eyelid. Scabs overlying the epidermis contained large gram-positive cocci; lesser numbers of small cocci and gram-negative bacilli were in more superficial areas. Staphylococcus hyicus was isolated from birds in all stages of the disease. Escherichia coli and Streptococcus sp. were isolated only during severe stages; no anaerobic bacterial pathogens were isolated. Vasculitis and perivascular lymphocytic infiltrates in deep layers of the dermis suggested that a staphylococcal toxin may have been involved. The disease was not reproduced by scarifying S. hyicus onto the eyelids or by intravenous inoculation of retro virus-infected chickens.
Retrovirus-associated Ovine Pulmonary Carcinoma (Sheep Pulmonary Adenomatosis) and Lymphoid Interstitial Pneumonia. I. Lesion Development and Age Susceptibility
Authors: Rosadio R. H. , Lairmore M. D. , Russell H. I. , DeMartini J. C.
Published: January 2010

To determine the lesion development of retrovirus-induced ovine pulmonary carcinoma (OPC), ten neonatal lambs were inoculated intratracheally with either 1) lung fluid preparations derived from a sheep with Type D retrovirus-associated OPC and concurrent ovine lentivirus (OvLV)-associated lymphoid interstitial pneumonia (LIP) ( n = 8); or 2) lung fluid from a sheep with only OvLV-LIP ( n = 2). Seven of eight neonates that received Type D retrovirus-associated OPC/OvLV-LIP lung fluid developed both OPC and LIP lesions between 9 and 32 weeks after inoculation. Mild OPC lesions consisted of foci of type II alveolar epithelial cells lining alveoli surrounded by minimal alveolar macrophage infiltrates. More severe OPC lesions consisted of multifocal aggregates of cuboidal to columnar neoplastic cells forming acini or masses associated with abundant alveolar macrophage infiltrates. Lesions of LIP consisted of peribronchiolar and perivascular lymphoid hyperplasia and heterogeneous interstitial leukocytic infiltrates. The two neonates that received OvLV-LIP lung fluid developed rapid and severe LIP, but not OPC lesions. Two lambs (inoculated as neonates with virus-free lung fluid) and three lambs (uninoculated contacts) served as controls and did not develop OPC. To investigate age susceptibility for development of OPC, 20 additional lambs within defined age groups (neonates, 2 weeks old, 5 weeks old, and 10 weeks old) received ultracentrifuged tumor homogenate. Neonatal to 5-week-old lambs inoculated with Type D retrovirus-associated OPC/OvLV-LIP tumor homogenate were equally likely to develop OPC, but lambs inoculated at 10 weeks of age were more refractory to tumor development. These results suggest that infection of sheep by the OPC retrovirus early in life enhances susceptibility to pulmonary neoplasia and defines methods to optimize experimental reproduction of this retrovirus-induced carcinoma.
A Pathologic and Toxicologic Evaluation of Veal Calves Fed Large Amounts of Zinc
Authors: Graham T. W. , Holmberg C. A. , Keen C. L. , Thurmond M. C. , Clegg M. S.
Published: January 2010

Tissues were examined from 26 male Holstein veal calves given large amounts of dietary zinc. All calves had been fed 706 μg zinc/g of milk replacer for 28 days before the first death occurred. Calves died naturally (14, group A) or were euthanatized (12, group B) after 23 days of feeding a lower concentration of zinc (150 μg/g). Average amounts of zinc in liver (wet weight) were 345.72 μg/g (group A) and 344.84 μg/g (group B). Mean kidney zinc concentrations were 219.0 μg/g (group A) and 252.38 μg/g (group B). Tissue manganese, copper, and iron levels were normal. Changes at necropsy included pneumonia, fluid digesta, and petechiae and infarcts in liver, kidney, and heart (as a result of bacterial infections). Histological changes that were directly attributed to dietary zinc intake were: marked atrophy and necrosis of pancreatic acinar tissue (group A); multifocal fibrosis of pancreatic acini (group B); multifocal renal cortical fibrosis with necrosis in convoluted tubules and loops of Henle, and with intratubular mineralization (groups A and B). Hepatic midzonal mineralization and fibrosis of the adrenal zona glomerulosa were seen in group B calves.
Histogenesis of Neoformation in the Endocrine Pancreas of Aging Horses
Authors: Furuoka H. , Shirakawa T. , Taniyama H. , Ohishi H. , Satoh H. , Itakura C.
Published: January 2010

Pancreatic tissue from 20 horses was examined using immunocytochemical techniques. In aged horses, neogenesis of endocrine cells, neoformation, and hyperplasia of islets occurred closely associated with the pancreatic duct; these changes were regarded as nesidioblastosis. In addition, pancreatic fibrosis accompanied by ductal proliferation and endocrine neogenesis was considered a regenerative change. Thus, the origin of neoformation in the endocrine pancreas was in the ductal system, and it is suggested that the pancreatic endocrine cells were of endodermal origin.
Degeneration of Cartilage Canal Vessels Associated With Lesions of Osteochondrosis in Swine
Authors: Carlson C. S. , Hilley H. D. , Meuten D. J.
Published: January 2010

Articular-epiphyseal cartilage complexes from the distal femur and humerus of five 3-month-old pigs were collected and preserved using either a conventional or a ruthenium hexammine trichloride (RHT)-supplemented fixation technique. Lesions were similar regardless of the fixation technique. Areas of necrosis were in epiphyseal but not articular cartilage from both sites of all pigs. Cartilage canals were confined to epiphyseal cartilage and contained vessels which had endothelial cells in varying stages of degeneration and necrosis. Areas of necrotic cartilage often were adjacent to or surrounded degenerate cartilage canals. Lipid emboli (up to 40.0 γm in diameter) were infrequently located in vessels within cartilage canals. Associated with the lipid emboli were leukocytes, erythrocytes, necrotic cell remnants, and flocculent material. Restriction of necrosis to epiphyseal cartilage and the association of these necrotic areas with degenerating vessels in cartilage canals strongly implicate a defect in cartilage canal blood supply in the pathogenesis of osteochondrosis. The RHT fixation technique resulted in excellent cellular detail at the light microscopic level, but ultrastructurally there was marked vacuolation of chondrocytes and matrix. The conventional technique caused shrinkage of all chondrocytes, resulting in a wide halo of pericellular matrix surrounding each cell.
Histopathologic and Immunocytochemical Studies of Distemper in Seals
Authors: Kennedy S. , Smyth J. A. , Cush P. F. , Duignan P. , Platten M. , McCullough S. J. , Allan G. M.
Published: January 2010

Thousands of harbor seals ( Phoca vitulina) died in European seas during 1988. Respiratory distress and oculonasal discharge were common clinical signs. We necropsied 76 affected seals. The main necropsy finding was severe pneumonia. Microscopic lung changes were characterized by proliferation of type II pneumocytes, filling of alveolar lumina with serofibrinous exudate, leukocytes, and macrophages, and necrosis of bronchial and bronchiolar epithelium. Intracytoplasmic and intranuclear acidophilic inclusion bodies characteristic of morbillivirus infection were seen in bronchial and bronchiolar epithelial cells. Microscopic lesions of non-suppurative demyelinating encephalitis were seen in the brain. There was degeneration and necrosis of neurons, focal gliosis, perivascular cuffing, and patchy demyelination. Many neurons and astrocytes contained intracytoplasmic and intranuclear inclusions. Using an immunoperoxidase technique, we detected morbillivirus antigen in many tissues including lung, brain, spleen, and urinary bladder. The origin of the seal morbillivirus is unknown.
Canine GM2 Gangliosidosis: Morphological and Biochemical Analysis
Authors: Singer H. S. , Cork L. C.
Published: January 2010

β-hexosaminidase activity and the effects of ganglioside storage on neuronal function were examined in a German shorthair pointer (GSHP) with progressive neurodegenerative signs. Morphologic evidence of neuronal storage and massive accumulation of GM2 ganglioside were present. β-hexosaminidase activity in plasma, liver, kidney, and brain, assayed with use of unsulfated fluorogenic substrates, was normal. There was no pathologic accumulation or aberrant localization of phosphorylated neurofilaments in neurons. Activity of cortical neurotransmitter synthesizing enzymes, choline acetyltransferase, and glutamate decarboxylase was unaffected. Ligand binding to carrier sites for choline high affinity uptake identified with [3H]hemicholinium-3 was increased, whereas post-synaptic binding to muscarinic cholinergic ([3H]QNB) and gamma-aminobutryic acid receptors ([3H]muscimol) was reduced.
Feline Oral Neoplasia: A Ten-Year Survey
Authors: Stebbins K. E. , Morse C. C. , Goldschmidt M. H.
Published: January 2010

A retrospective histological study was conducted on 371 neoplasms of the oral cavity in cats. Oral neoplasia accounted for 10% of feline neoplasms identified during the survey period. Eighty-nine percent of the oral neoplasms were malignant. Twenty different oral neoplasms were found. The most common were squamous cell carcinoma (61.2%), fibrosarcoma (12.9%), and fibromatous epulis of periodontal ligament origin (7.8%).
Ultrastructural Analysis of Platelets and Megakaryocytes from a Dog with Probable Essential Thrombocythemia
Authors: Tablin F. , Jain N. C. , Mandell C. P. , Hopper P. E. , Zinkl J. G.
Published: January 2010

Blood platelets and bone marrow megakaryocytes from a dog with essential thrombocythemia were analyzed by transmission electron microscopy and compared with those of control dogs. Platelets varied in size and shape and contained enlarged and dilated open canalicular systems. Megakaryocytes were dysmorphic and had evidence of abnormal maturation, with large numbers of megakaryoblasts containing alpha granules and poorly organized and reduplicated demarcation membranes. The fewer, more mature megakaryocytes lacked normal cytoplasmic organization. Most notable was the absence of well-demarcated “platelet fields,” due to the excessive and disorderly array of demarcation membranes.
Morphology of Leukocytes from Cats Affected with α-Mannosidosis and Mucopolysaccharidosis VI (MPS VI)
Authors: Alroy J. , Freden G. O. , Goyal V. , Raghavan S. S. , Schunk K. L.
Published: January 2010

The morphology and ultrastructure of circulating white blood cells from six Persian and from five Russian Blue/Siamese cats deficient in lysosomal activity of α-mannosidase and arylsulfatase B, respectively, were studied and compared to cells from corresponding normal and carrier cats. In cats with mannosidosis, light microscopic examination revealed vacuoles in lymphocytes and monocytes, whereas electron microscopic studies demonstrated additional vacuoles in neutrophils, eosinophils, and basophils. In cats with mucopolysaccharidosis VI (MPS VI), vacuoles containing metachromatic granules were observed in lymphocytes, neutrophils, eosinophils, and monocytes. Ultrastructural studies of these cells identified the accumulation of fibrillar material, which often was associated with lamellated membrane structures.
Pulmonary Alveolar Microlithiasis in Afghan Pika (Ochotona rufescens rufescens)
Authors: Madarame H. , Kumagai M. , Suzuki J. , Watanabe A. , Konno S.
Published: January 2010

Lung lesions of 60 Afghan pikas ( Ochotona rufescens rufescens) were examined histologically; 38 cases of pulmonary alveolar microlithiasis were found. Neither sex was predominantly affected, and there was no predilection for age.
Transitional Cell Carcinomas of the Urinary Tract in a Colony of Beagle Dogs
Authors: Nikula K. J. , Benjamin S. A. , Angleton G. M. , Lee A. C.
Published: January 2010

Gross and light microscopic features of transitional cell carcinomas (TCC) of the urinary tract were examined in Beagle dogs used for the study of the long-term effects of low-dose, whole-body, 60Co gamma radiation. Thirty-eight cases of TCC occurred among 990 dogs that were from 0 to 14 years of age. There was no conclusive evidence of a radiation effect. The 38 TCC were equally divided between male and female dogs, but there was a significant difference in the sex distribution of urethra-origin TCC. Eleven males had a primary urethral TCC compared to only two females. There was no significant difference between the urethra-origin and bladder-origin TCCs in the number of tumors that caused clinical signs, metastasized, or that contributed to the death of the dog. All cases of urethral TCC in male dogs occurred in the prostatic urethra. The majority of these cases were not recognized to be neoplasms at gross necropsy, but microscopic examination revealed the TCC. Our findings differ from previous reports stating that TCC occurs more frequently in female than male dogs, and they especially differ from reports claiming that urethra-origin TCC is predominately a disease of female dogs.
Effect of Chronic Administration of Recombinant Bovine Tumor Necrosis Factor to Cattle
Authors: Ohmann H. Bielefeldt , Campos M. , Snider M. , Rapin N. , Beskorwayne T. , Popowych Y. , Lawman M. J. P. , Rossi A. , Babiuk L. A.
Published: January 2010

Cachectin/tumor necrosis factor-alpha (TNF), a protein produced by macrophages upon stimulation, has been implicated as an important mediator of inflammatory processes and of clinical manifestations in chronic infectious diseases. In order to study further the potential role of TNF in infectious diseases, a homologous system was employed in which recombinant Escherichia coli (E. coli) derived bovine TNF (rBoTNF) was injected in cattle, either as a single bolus or in a repetitive treatment-regime. No clinical signs were observed, although changes occurred in hematologic and immunologic parameters when less than 0.5 mg of TNF/100 kg body weight was administered twice daily for 18 days. Prolonged treatment with 0.05–0.5 mg/100 kg induced histologic but no gross changes in the kidneys and liver. When doses were increased above 0.5 mg/100 kg, depression, anorexia, cachexia, and diarrhea appeared rapidly. Pathologic changes were apparent in various tissues including liver, kidneys, and lymphoid organs; body fat depots were depleted. Most of these changes appeared to be reversible; return to normal tissue-morphology occurred within 3 weeks of withdrawal of rBoTNF. The clinical and pathologic changes induced by prolonged rBoTNF administration resembled those observed in some chronic parasitic and viral infections of cattle in which macrophage-activation characteristically occur. Our finding may be relevant to the elucidation of the pathogenesis of these and other chronic infections.
Naturally Occurring Orocutaneous Papillomas and Carcinomas of Brown Bullheads (Ictalurus nebulosus) in New York State
Authors: Poulet F. M. , Wolfe M. J. , Spitsbergen J. M.
Published: January 2010

Ninety-four brown bullheads ( Ictalurus nebulosus) with spontaneous orocutaneous neoplasms (papillomas and carcinomas) were studied grossly and by light microscopy. Of these 94 fish, 71 were selected from 505 fish examined macroscopically during field surveys and 23 were selected from those submitted for diagnostic study. Fish with neoplasms came from 17 locations throughout New York State: Buffalo River, Canaan Lake, Cazenovia Lake, Delta Lake, Fort Pond, Greenwood Lake, Hudson River, Lake George, Lake Tiorati, Lincoln Hall Pond, Lincoln Pond, Oneida Lake, Onondaga Lake, Rutland Pond, Salmon River, Silver Stream Reservoir, and Swan Lake. The prevalence varied from 0 to 100%. Multiple neoplasms were more common (84/94, 89%) than solitary ones (10/94, 11%). In order of decreasing frequency, neoplasms arose on the head, especially the ventral aspect, the lower dental plate, the upper dental plate, the trunk, the barbels, the fins, the tongue, and the tail. Of the 38/94 brown bullheads (40%) with tumors in both upper and lower lips and dental plates, 24/38 (63%) had the tumors in opposition. Macroscopically, soft, pink or yellowish papillary masses protruded above the normal epithelial surfaces. Histologically, cutaneous and oral neoplasms originated from the morphologically similar Malpighian epithelial cells of the surface epithelia and from the outer cells of the enamel organ. Based on histopathologic criteria, cutaneous and oral neoplasms were considered the same disease in different anatomic locations. No apparent difference in biologic behavior was noted between cutaneous and oral neoplasms. The lesions apparently progressed from benign papilloma to locally invasive carcinoma (28/94, 30%). Neoplastic emboli were seen in one case, and no metastases were detected. There was no statistically significant difference between the susceptibility of males (20/57, 35%) and females (6/26, 23%) to carcinomas. An apparent correlation was noted between a higher frequency of malignant tumors and longer body size (3/ 13 fish [23%] <30 cm, 17/54 fish [31%] 30–34 cm, and 7/18 fish [39%] >34 cm).
Signs and Lesions of Experimental Sendai Virus Infection in Two Genetically Distinct Strains of SCID/Beige Mice
Authors: Percy D. H. , Auger D. C. , Croy B. A.
Published: January 2010

The pathogenesis of Sendai virus infection was studied in genetically immunodeficient mice of genotype scid/scid.bg/bg (SCID-beige) using C.B-17 SCID-beige mice, a BALB/c-related strain that expresses the same major histocompatibility complex as the Sendai virus-susceptible DBA/2 (H-24). Mice were inoculated intranasals with isolate 771076 of Sendai virus, then killed at 2-day intervals beginning on day 4 post-inoculation. Clinical signs were evident beginning at 8 to 10 days post-inoculation, and all animals remaining were killed in extremis by 14 to 17 days post-inoculation. Lesions in inoculated mice were confined to the respiratory tract. In the nasal passages, a nonresolving rhinitis, with epithelial hyperplasia/metaplasia occurred. Cranioventral bronchopneumonitis was characterized by marked hyperplasia and necrosis of epithelial cells lining airways and with leukocytic infiltration. At the alveolar level, there was marked hypertrophy and hyperplasia of type II pneumocytes, mobilization of alveolar macrophages, and obliteration of the normal architecture in severely affected areas. Viral antigen was evident beginning at 4 days post-inoculation and persisted in affected areas throughout the duration of the study. Because immunocompetent C57BL/6 mice are known to be genetically resistant to Sendai virus, the susceptibility of C57B/6 SCID-beige to Sendai virus was then compared to that of C.B-17 SCID-beige mice. In age-matched animals of the two strains, there was no evidence of natural resistance to Sendai virus infection in the immunodeficient C57BL/6 strain compared to the C.B-17 mice. These studies indicate that the genetic differences in susceptibility of two strains of immunocompetent mice to Sendai virus infection are eliminated by expression of the mutations scid and beige.
Tumors in St. Lawrence Beluga Whales (Delphinapterus leucas)
Authors: Guise S. De , Lagacé A. , Béland P.
Published: January 2010

A population of 450–500 belugas ( Delphinapterus leucas) resides in the polluted estuary of the St. Lawrence River. Stranded carcasses of this endangered population were recovered and necropsied. High concentrations of organochlorines, heavy metals, and benzo-a-pyrene exposure were demonstrated in tissues of these whales. Between 1988 and 1990, 21 tumors were found in 12 out of 24 carcasses. Among these tumors, six were malignant and 15 were benign. The animals were between 1.5 and >29 years of age, and the ages of animals with and without tumors did not differ when two juvenile animals (1.5 and 3.5 years of age) were excluded. Seven other neoplasms had been reported previously in six out of 21 well-preserved carcasses examined in the same laboratory between 1982 and 1987. Overall, 28 of the 75 confirmed tumors reported so far in cetaceans (37%) were from this small population of beluga whales in the St. Lawrence Estuary. Such a high prevalence of tumors would suggest an influence of contaminants through a direct carcinogenic effect and/or a decreased resistance to the development of tumors in this population.
Hereditary Suprabasilar Acantholytic Mechanobullous Dermatosis in Buffaloes (Bubalus bubalis)
Authors: Riet-Correa F. , Barros S. S. , Dame M. C. , Peixoto P. V.
Published: January 2010

A skin disease characterized by trauma-induced sloughing of haired skin, hooves, and horns is described in four calves from a herd of Murrah buffaloes ( Bubalus bubalis) in Brazil. Affected calves were detected shortly after birth by the presence of lesions affecting the distal extremities, the scapular and gluteal regions, and the tip of the tail. On histologic evaluation of affected skin, the lesions were characterized by suprabasilar vesicles and acantholysis affecting the epidermis and outer root sheath of the hair follicle infundibulum. The basal cell layer was intact and appeared as a single layer of cuboidal cells attached to the dermis. Ultrastructurally, the region between the stratum basale and the lower stratum spinosum had widened intercellular spaces with loss of desmosomal attachments, which led to the suprabasilar separation. The disease appears to be inherited as an autosomal recessive trait.
Malignant Rhabdoid Tumor in the Gastric Wall of an Aged Orangutan (Pongo pygmaeus)
Authors: Schauer G. , Moll R. , Walter J. H. , Rumpelt H. J. , Göltenboth R.
Published: January 2010

A 34-year-old female orangutan ( Pongo pygmaeus) developed renal failure and became uremic. At necropsy, large gastric masses were present around the cardia and in the corpus. Abdominal metastases occurred in the liver, pancreas, and right ovary. Light microscopic examination of the tumor revealed polygonal cells with vesicular nuclei and prominent nucleoli. The growth pattern was predominantly solid. Focal areas contained excentric cytoplasmic intermediate filament inclusions, as identified by immunohistochemistry and electron microscopy. Immunohisiochemical procedures demonstrated mainly the vimentin type of intermediate filaments. Except for occasional cytokeratin, other intermediate filament markers and neural, lymphocytic, and histiocytic markers stained negative. The morphologic and ultrastructural characteristics are typical for a malignant rhabdoid tumor, a term used in human pathology to describe a rare and extremely aggressive malignancy of uncertain histogenesis. Although usually located in the infant kidney, a few reports have documented the occurrence of similar lesions in extrarenal sites of adults. In human tumors, vimentin is often combined with the expression of cytokeratins. The sparsity of the cytokeratin filaments in this case might be due to species-specific variations and/or may reflect the hypothesis of a phenotypic concept encompassing a spectrum of histogenetic diversity.
Equine Glucose-6-phosphate Dehydrogenase Deficiency
Authors: Stockham S. L. , Harvey J. W. , Kinden D. A.
Published: January 2010

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a well-characterized X-linked inherited disorder in humans but has not been reported in horses. We describe a persistent hemolytic anemia and hyperbilirubinemia due to a severe G6PD deficiency in an American Saddlebred colt. Other abnormalities in the colt's erythrocytes as compared with those of healthy horses ( n = 22–35) included increased activities of hexokinase and pyruvate kinase, decreased concentrations of reduced glutathione and reduced nicotinamide adenine dinucleotide phosphate (NADP), and increased concentration of oxidized NADP. Morphologic abnormalities included eccentrocytosis, pyknocytosis, anisocytosis, macrocytosis, and increased number of Howell-Jolly bodies. Scanning and transmission electron microscopic examinations revealed that eccentrocytes had contracted to spherical regions and thin collapsed regions. Eccentrocytes were more electron dense than were normal erythrocytes when examined by transmission electron microscopy. When exposed to acetylphenylhydrazine, erythrocytes from the G6PD-deficient colt produced more and smaller Heinz bodies than did erythrocytes from normal horses. Abnormalities in the colt's dam included presence of eccentrocytes and pyknocytes; her average erythrocyte G6PD activity was slightly below the range of reference values.
Testicular Maturation in Prepubertal New Zealand White Rabbits
Authors: Frame S. R. , Hurtt M. E. , Green J. W.
Published: January 2010

Testicular maturation was assessed in age-matched, sexually immature (13–17-week-old) New Zealand white rabbits using end points frequently evaluated in toxicity studies: testicular weight and testicular histology. Testicular weights and testicular maturity as assessed histologically were markedly variable in sexually immature rabbits, especially at ≥ 14 weeks of age. The large variation in testicular weights in immature rabbits requires that large changes in a treatment group relative to controls be present for statistical detection of testicular weight effects at commonly used significance levels. Testicular weights and testicular maturity were strongly correlated to one another, but neither weight nor maturity was strongly correlated to body weight. Thus, stratification and randomization of immature rabbits to study groups based upon body weight will not assure in absence of group differences with respect to testicular maturity. The large variation in testicular weights and maturity in 13–17-week-old rabbits warrants caution in the evaluation of testicular changes when rabbits of this age range are used in toxicity studies.
Vascular Mineralization in the Monkey Brain
Authors: Yanai T. , Masegi T. , Ueda K. , Manabe J. , Teranishi M. , Takaoka M. , Matsunuma N. , Fukuda K. , Goto N. , Fujiwara K.
Published: January 2010

Mineralization of various degrees was found in the brains of 79 (59%) of 134 cynomolgus monkeys ( Macaca fascicularis). There was no age dependency in the incidence or severity, nor were there any abnormalities in growth, weight gain, or neurologic signs, although a slight sex difference was observed. The lesions, which were basophilic and intensely positive for periodic acid-Schiff or von Kossa stain, occurred in the vascular walls of the globus pallidus in two types: globoid bodies with prominent concentric lamellar structures in and around the arteriolar and venular wall (type A) and fine granules in the media of small or medium-sized arteries (type B). Electron microscopic examination revealed dense deposits in the degenerated media of small or medium-sized arteries or the thickened walls of the arterioles. X-ray microanalysis demonstrated the presence of calcium, phosphorus, iron, zine, magnesium, and aluminum.
Squamous Metaplasia of Bronchiolar Cell-derived Adenocarcinoma Induced by N-nitrosomethyl-n-heptylamine in Syrian Hamsters
Authors: Rehm S. , Lijinsky W.
Published: January 2010

Morphology and development of experimental bronchiolar lung tumors were studied in Syrian hamsters, using light and electron microscopic techniques. At the age of 9 weeks, 46 hamsters were each given one weekly gavage of 6.8 mg N-nitrosomethyl- n-heptylamine for 35 weeks, and hamsters were examined at intervals from 2 to 46 weeks. The present report describes the progression of adenocarcinomas of bronchiolar cell origin to adenosquamous and squamous cell carcinomas. Squamous metaplasia was commonly noted at the tumor periphery, i.e., zone of growth. In 20 hamsters, 22 adenosquamous and two squamous cell carcinomas (one a large cell carcinoma) were diagnosed by light microscopy. Overt keratinization was infrequent. Squamous cell metaplasia was not a feature of papillary neoplasms but was seen mainly with acinar structures. Ultrastructurally, squamous differentiation (metaplasia) appeared to develop along two different pathways. First, secretory cells were observed with large numbers of intermediate filaments and tonofilaments, with concurrent loss of organelles such as secretory granules and microvilli. Second, squamous metaplasia also appeared to develop from a progeny of tumor cells that failed to mature into secretory cells. Such cells were often present within the basal layer of secretory acini and resembled basal cells of the tracheobronchial tree. These observations were supported by increased expression of cytokeratins, as revealed by immunohistochemical procedures. Immunoelectron microscopic examination localized hamster Clara cell antigen in secretory granules of neoplastic Clara cells, in the cytoplasm between granules, and at the microvillous border. With the onset of squamous differentiation, Clara cell antigen was progressively lost from secretory cells and was only rarely seen in cells with tonofilaments. No labeling was present in squamous cells arising at the base of tumor acini. These results suggest that pulmonary squamous cell carcinomas may develop by direct squamous differentiation of secretory cells or may proceed from undifferentiated tumor cells.
Echinocytosis Associated with Rattlesnake Envenomation in Dogs
Authors: Brown D. E. , Meyer D. J. , Wingfield W. E. , Walton R. M.
Published: January 2010

A retrospective study of 28 cases of rattlesnake bites in dogs indicated an association of envenomation with echinocytosis; 25/28 dogs (89%) had echinocytosis within 24 hours of a rattlesnake bite being reported. Eighteen of the 28 dogs had marked type III echinocytosis (95–100% of mature erythrocytes affected), and seven dogs had moderate echinocytosis (15–30% of mature erythrocytes affected). The echinocytosis was transient, resolving within 48 hours of envenomation in those for which subsequent blood films were available (13/25). Hypokalemia was noted in 14 of 18 dogs for which biochemical data were available. The hypokalemia was not consistently associated with echinocytosis. The observation of echinocytosis in dogs supports a clinical diagnosis of rattlesnake envenomation.
Enzyme-linked Immunosorbent Assay to Measure Serum Ferritin and the Relationship between Serum Ferritin and Nonheme Iron Stores in Cats
Authors: Andrews G. A. , Chavey P. S. , Smith J. E.
Published: January 2010

Serum ferritin concentration correlates with tissue iron stores in humans, horses, calves, dogs, and pigs but not in rats. Because serum iron and total iron-binding capacity can be affected by disorders unrelated to iron adequacy (such as hypoproteinemia, chronic infection, hemolytic anemia, hypothyroidism, and renal disease), serum ferritin is probably the most reliable indicator of total body iron stores in larger species. To test the hypothesis that serum ferritin might be correlated with tissue iron levels in cats, we developed a quantitative enzyme-linked immunosorbent assay that uses two monoclonal antibodies in a sandwich arrangement to measure feline serum ferritin. The recovery of purified ferritin added to feline sera ranged from 94% to 104%; the within-assay coefficient of variability was 8.4%, and the assay-to-assay variability was 13.2%. Mean serum ferritin from 40 apparently healthy cats was 76 ng ml (SD = 24 ng/ml). Serum ferritin concentration was significantly correlated ( P < 0.001, n = 101, r = 0.365) with the nonheme iron in the liver and spleen (expressed as milligrams of iron per kilogram of body weight), as determined by Pearson product-moment correlation analysis. Because serum iron can decrease in diseases other than iron deficiency, the combination of serum iron and serum ferritin should provide sufficient evidence to differentiate anemia of chronic inflammation from anemia of iron deficiency in the cat.
Fatty Acid-mediated Gastroprotection Does Not Correlate with Prostaglandin Elevation in Rats Exposed to Various Chemical Insults
Authors: Mandel K. G. , Bertram T. A. , Eichhold M. K. , Pepple S. C. , Doyle M. J.
Published: January 2010

This study involved a comparison of activity of several long-chain fatty acids (arachidonic acid, dihomo-[γ]-linolenic acid, linoleic acid, and oleic acid) for protection against gastric mucosal damage elicited by taurocholic acid, acidified aspirin, and ethanol in rats. Each damaging agent induced gastric mucosal lesions in the corpus. Mucosal damage was induced by all agents, and all fatty acids protected the gastric mucosa; however, ethanol and arachidonic acid were the most potent damaging and protecting agents, respectively. Maximally protective doses for prevention of taurocholic acid-induced damage by arachidonic, dihomo-[γ]-linolenic, linoleic, and oleic acids were 50, 200, 100, and 200 mg/kg, respectively; however, 10 mg/kg arachidonic acid reduced lesion length by >50%, whereas minimally effective doses of the other fatty acids were ≥50 mg/kg. Similar potency differences were observed for fatty acid protection against acidified aspirin-induced gastric damage. Although all the fatty acids reduced macroscopic damage, histologic studies showed they did not totally eliminate surface mucosal damage. Microscopic analysis showed that treatment with dihomo-[γ]-linolenic acid or oleic acid attenuated depletion of neutral and acidic glycoproteins from the mucus neck cells of the gastric mucosa in response to exposure to taurocholic acid. Despite having similar gastroprotective activity, arachidonic, dihomo-[γ]-linolenic, linoleic, and oleic acids had very dissimilar abilities to elevate gastric mucosal E-series prostaglandins. Both arachidonic and dihomo-[γ]-linolenic acids elevated E-series prostaglandins, but arachidonic acid had 2–5-fold greater gastroprotective potency. Furthermore, oleic and linoleic acids, which had protective potency similar to that dihomo-[γ]-linolenic acid, did not significantly elevate prostaglandins. These studies failed to demonstrate an absolute correlation between prostaglandin elevation and gastroprotection. The results of this investigation suggest that prostaglandin elevation, although associated with gastroprotection, does not appear to be the sole mechanism for fatty acid-mediated protection of rat gastric mucosa.
Naturally Occurring Tyzzer's Disease in a Puppy
Authors: Young J. K. , Baker D. C. , Burney D. P.
Published: January 2010

A naturally occurring case of Tyzzer's disease due to infection with Bacillus piliformis in a wolf-dog hybrid resulted in widely disseminated lesions, including severe myocarditis, hepatitis, enterocolitis, intestinal leiomyositis, and adrenal cortical adenitis. Previously reported lesions for canine Tyzzer's disease have been limited to hepatic necrosis and a necrotizing enterocolitis.
Spontaneous Diabetes Mellitus Associated with Persistent Bovine Viral Diarrhea (BVD) Virus Infection in Young Cattle
Authors: Taniyama H. , Ushiki T. , Tajima M. , Kurosawa T. , Kitamura N. , Takahashi K. , Matsukawa K. , Itakura C.
Published: January 2010

Histologic and immunohistochemical studies were carried out on four young cattle with diabetes mellitus associated with persistent bovine viral diarrhea (BVD) virus infection. Clinical findings included persistent hyperglycemia, decreased glucose tolerance, glycosuria, polydipsia, and severe emaciation. Macroscopically, multiple erosions and ulcers in the mucosa of upper and lower alimentary tracts and swollen lymph nodes were commonly observed. Erosions and ulcers in the mucosa of tongue, esophagus, and forestomach were represented histologically by necrosis of squamous epithelium with neutrophilic infiltration. In the small and large intestines, villous atrophy and suppurative cryptitis were often observed, along with diffuse infiltration of lymphocytes and macrophages and fibroplasia in the lamina propria. In the pancreas of all cattle, there was a reduction in the number of islet cells, and most of the residual islet cells had hydropic degeneration and a decreased number of secretory granules. Immunohistochemical examination confirmed that these cells were severely degranulated β-cells. In addition, many islets containing necrotic islet cells were observed. These islet cells had increased eosinophilia and shrinkage of cytoplasm, as well as pyknotic nuclei. Inflammation of the islets with mild infiltration of lymphocytes was observed in all pancreatic lobes. In addition, bovine IgG-immunoreactive cells were identified immunohistochemically in the affected pancreatic islets. The BVD virus antigen was not identified in the cytoplasm of the islet cells by immunohistochemical study, although it was identified in the epithelial cells of the small intestine. The histologic and immunohistochemical studies demonstrated that the pancreatic lesions in these animals were similar to those caused by acute insulin-dependent diabetes mellitus (IDDM) in human beings. These findings suggest that IDDM in Japanese Black cattle is an autoimmune disease induced through persistent infection by BVD virus.