- Expression of MMP-2 and MMP-9 in Benign Canine Rostrotentorial Meningiomas Is Not Correlated to the Extent of Peritumoral Edema 15 novembre 2013
Beltran, E., Matiasek, K., Risio, L. D., Stefani, A. d., Feliu-Pascual, A. L., Matiasek, L. A.
Matrix metalloproteinases (MMPs) are proteolytic enzymes involved with extracellular matrix degradation. They have been considered to be important for tumor growth and development of peritumoral edema. This retrospective study investigated the expression of MMP subtypes 9 and 2 in canine intracranial meningiomas and their association with peritumoral edema. Twenty-two cases of histologically confirmed grade I meningiomas based on human World Health Organization classification were enrolled. Tumor volume and peritumoral edema were measured by magnetic resonance imaging volumetry. The intratumoral MMP expression was semiquantitatively assessed by immunoreactivity scores and compared with the imaging data. MMP-9 was expressed in all the samples (22/22), whereas proMMP-2 was expressed in 21 of 22 meningiomas, and a/proMMP-2 was expressed in 9 of 22. The immunoreactivity scores were not statistically linked to the severity of peritumoral edema. None of the evaluated MMP expression parameters were statistically linked to the edema index. Although both edema index and MMP-9 expression were highest in meningiomas of the olfactory and frontal region, only the latter mounted up to statistical significance (P = .002) if compared with parafalx and convexity meningiomas of the parietal lobe. In summary, MMP-2 and MMP-9 expression by tumor cells, evaluated through immunohistochemistry, is not predictive of the formation of peritumoral edema in canine rostrotentorial meningiomas.
- Histological Characterization of Dilated Cardiomyopathy in the Juvenile Toy Manchester Terrier 13 novembre 2013
Legge, C. H., Lopez, A., Hanna, P., Cote, E., Hare, E., Martinson, S. A.
Dilated cardiomyopathy (DCM), the most common form of cardiomyopathy in the dog, most often occurs in certain breeds. The objective of this study was to describe a rapidly progressive form of DCM that has been recently recognized in juvenile Toy Manchester Terrier dogs (TMTs). The clinical history and gross findings were reviewed in a group of 14 TMTs, and histologic sections of heart were examined in 12 of those 14 TMTs with DCM. Histochemical and histomorphometric analyses were employed to compare the heart in TMTs affected by DCM with that of control dogs. TMTs ranged in age from 10 to 58.3 weeks, with males and females being equally affected. Affected TMT hearts contained foci of degeneration and loss of myofibers with fibrosis and mild lymphoplasmacytic infiltrates. Less prominent features included foci of acute myofiber degeneration and necrosis with or without intralesional mineralization and mild to moderate suppurative and lymphoplasmacytic infiltrates. Morphometric quantification demonstrated that the right ventricle was more severely affected (P ≤ .05) than the left ventricle with variable involvement of the interventricular septum. Immunohistochemistry for canine parvovirus was negative in all heart samples. However, the absence of parvoviral antigen does not rule out a possible viral or autoimmune cause. The presence of these myocardial lesions among closely related dogs suggests a genetic contribution to this disease process in the TMT.
- Psittacid Herpesvirus 3 Infection in the Eclectus Parrot (Eclectus roratus) in Australia 13 novembre 2013
Gabor, M., Gabor, L. J., Peacock, L., Srivastava, M., Rosenwax, A., Phalen, D.
Psittacid herpesvirus 3 (PsHV-3) has recently been implicated as the cause of a severe respiratory disease in Bourke’s parrots (Neopsephotus bourkii) in the United States. In this report, the clinical manifestations and gross and microscopic lesions of PsHV-3 infection in 2 eclectus parrots (Eclectus roratus) in Australia are described. The presence of a PsHV-3 infection was confirmed by polymerase chain reaction amplification and sequencing of PsHV-3 DNA using degenerate and PsHV-3 primers. Electron microscopy of infected cells demonstrated the assembly of herpesvirus virions as well as intranuclear tubular structures. The detection of PsHV-3 in Australia in 2 eclectus parrots broadens the list of known affected species and confirms the presence of this virus in Australia.
- Distribution of Eastern Equine Encephalomyelitis Viral Protein and Nucleic Acid Within Central Nervous Tissue Lesions in White-tailed Deer (Odocoileus virginianus) 13 novembre 2013
Kiupel, M., Fitzgerald, S. D., Pennick, K. E., Cooley, T. M., O'Brien, D. J., Bolin, S. R., Maes, R. K., Piero, F. D.
An outbreak of eastern equine encephalomyelitis (EEE) occurred in Michigan free-ranging white-tailed deer (Odocoileus virginianus) during late summer and fall of 2005. Brain tissue from 7 deer with EEE, as confirmed by reverse transcriptase polymerase chain reaction, was studied. Detailed microscopic examination, indirect immunohistochemistry (IHC), and in situ hybridization (ISH) were used to characterize the lesions and distribution of the EEE virus within the brain. The main lesion in all 7 deer was a polioencephalomyelitis with leptomeningitis, which was more prominent within the cerebral cortex, thalamus, hypothalamus, and brainstem. In 3 deer, multifocal microhemorrhages surrounded smaller vessels with or without perivascular cuffing, although vasculitis was not observed. Neuronal necrosis, associated with perineuronal satellitosis and neutrophilic neuronophagia, was most prominent in the thalamus and the brainstem. Positive IHC labeling was mainly observed in the perikaryon, axons, and dendrites of necrotic and intact neurons and, to a much lesser degree, in glial cells, a few neutrophils in the thalamus and the brainstem, and occasionally the cerebral cortex of the 7 deer. There was minimal IHC-based labeling in the cerebellum and hippocampus. ISH labeling was exclusively observed in the cytoplasm of neurons, with a distribution similar to IHC-positive neurons. Neurons positive by IHC and ISH were most prominent in the thalamus and brainstem. The neuropathology of EEE in deer is compared with other species. Based on our findings, EEE has to be considered a differential diagnosis for neurologic disease and meningoencephalitis in white-tailed deer.
- Mast Cells in Canine Parvovirus-2-Associated Enteritis With Crypt Abscess 13 novembre 2013
Woldemeskel, M. W., Saliki, J. T., Blas-Machado, U., Whittington, L.
The role of mast cells (MCs) in allergic reactions and parasitic infections is well established. Their involvement in host immune response against bacterial and viral infections is reported. In this study, investigation is made to determine if MCs are associated with Canine parvovirus-2 (CPV-2)–induced enteritis with crypt abscess (ECA). Mast cell count (MCC) was made on toluidine blue–stained intestinal sections from a total of 34 dogs. These included 16 dogs exhibiting ECA positive for CPV-2 and negative for Canine distemper virus and Canine coronavirus by immunohistochemistry and fluorescent antibody test, 12 dogs with inflammatory bowel disease (IBD), and 6 non-ECA/non-IBD (control) dogs. The average total MCC per high-power field in ECA (40.8 ± 2.2) and IBD (24.7 ± 2.1) was significantly higher (P < .05) than in the control (3.4 ± 0.6). Although not significant (P > .05), MCC was also higher in ECA than in IBD. The present study for the first time has documented significantly increased MCs in CPV-2–associated ECA as was previously reported for IBD, showing that MCs may also play an important role in CPV-2–associated ECA. Further studies involving more CPV-infected dogs are recommended to substantiate the findings.
- Obesity: Bring on the Jiggle? 13 novembre 2013
- An Outbreak of Sodium Fluoroacetate (1080) Intoxication in Selenium- and Copper-Deficient Sheep in California 13 novembre 2013
Giannitti, F., Anderson, M., Caspe, S. G., Mete, A., East, N. E., Mostrom, M., Poppenga, R.
Sodium fluoroacetate is an organofluorine compound toxic to mammals, insects, and birds, currently registered for use only in livestock protection collars as a predacide in some North American states, with restricted use in California. A flock of 445 lambs and ewes in California were moved into a native pasture on a municipal refuse disposal site. Within 24 hours, 14 ewes were found dead, and the remaining sheep were moved off the site. Both ewes and lambs exhibited disoriented running, followed by apparent blindness, weakness, ataxia, coma, and death. Over the next 4 days, 63 ewes and 80 lambs died with a peak at 3 days after grazing the suspect pasture (157/445, 35% mortality). Two dead 4-month-old lambs and 2 ewes were submitted to the California Animal Health and Food Safety laboratory for necropsy. Grossly, there were bilateral diffuse pulmonary congestion and edema, hydrothorax and hydropericardium with fibrin clots, and multifocally extensive areas of epicardial petechiae, ecchymoses, and pallor. In 1 ewe, there was regional caudodorsal pulmonary hemorrhage and intraluminal tracheal clotted blood. Microscopically in all cases, there was multifocal acute myocardial degeneration and necrosis with nonsuppurative pleocellular myocarditis. Sodium fluoroacetate was detected in kidney from a lamb and a ewe at 27.5 and 12.5 parts per billion, respectively. All sheep were selenium deficient, and concurrent copper deficiency was diagnosed in 3. The pathological and toxicological findings were consistent with 1080 poisoning, possibly exacerbated by micronutrient deficiency. This outbreak raised an alert about the use of restricted products with potential lethal effect in animals in California.
- Middle East Respiratory Syndrome (MERS) Coronavirus: A New Challenge for Veterinarians? 13 novembre 2013
Gortazar, C., Segales, J.
- Principles for Valid Histopathologic Scoring in Research 13 novembre 2013
Gibson-Corley, K. N., Olivier, A. K., Meyerholz, D. K.
Histopathologic scoring is a tool by which semiquantitative data can be obtained from tissues. Initially, a thorough understanding of the experimental design, study objectives, and methods is required for the pathologist to appropriately examine tissues and develop lesion scoring approaches. Many principles go into the development of a scoring system such as tissue examination, lesion identification, scoring definitions, and consistency in interpretation. Masking (aka "blinding") of the pathologist to experimental groups is often necessary to constrain bias, and multiple mechanisms are available. Development of a tissue scoring system requires appreciation of the attributes and limitations of the data (eg, nominal, ordinal, interval, and ratio data) to be evaluated. Incidence, ordinal, and rank methods of tissue scoring are demonstrated along with key principles for statistical analyses and reporting. Validation of a scoring system occurs through 2 principal measures: (1) validation of repeatability and (2) validation of tissue pathobiology. Understanding key principles of tissue scoring can help in the development and/or optimization of scoring systems so as to consistently yield meaningful and valid scoring data.
- High-Pathogenicity Avian Influenza Virus in the Reproductive Tract of Chickens 13 novembre 2013
Silva, M. S. e., Rissi, D. R., Pantin-Jackwood, M., Swayne, D. E.
Infection with high-pathogenicity avian influenza virus (HPAIV) has been associated with a wide range of clinical manifestations in poultry, including severe depression in egg production and isolation of HPAIV from eggs laid by infected hens. To evaluate the pathobiology in the reproductive tract of chickens, adult hens were inoculated intranasally with 3 HPAIV strains. All 3 strains induced lesions in the reproductive tract 36 to 72 hours after inoculation. Positive immunostaining was observed in all segments of the reproductive tract, occurring predominantly in stromal cells and superficial germinal epithelium of the ovary, in mucosal epithelial cells and less often glandular epithelium throughout the oviduct, and in vascular endothelium. This study generates important data and explains previously reported virus isolation from yolk, due to ovarian virus replication, and virus recovery from albumin, due to virus replication in epithelial cells in several segments of the oviduct.