bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathologic Features of Naturally Occurring Juvenile Polyarteritis in Beagle Dogs
Authors: Snyder P. W. , Kazacos E. A. , Scott-Moncrieff J. C. , HogenEsch H. , Carlton W. W. , Glickman L. T. , Felsburg P. J.
Published: January 2010

Eighteen young Beagle dogs (eight males and 10 females), ages 6-40 months, with canine juvenile polyarteritis syndrome (CJPS), a naturally occurring vasculitis and perivasculitis of unknown etiology, were necropsied, and their tissues were examined by histopathologic and histochemical methods. The condition is characterized by recurring episodes of an acute onset of fever (>40 C) and neck pain that persist for 3-7 days. The major histopathologic alterations were a systemic vasculitis and perivasculitis. During the febrile, painful period of CJPS, the vascular lesions ranged from a histiocytic-lymphocytic periarterial infiltration to transmural arterial inflammation with concomitant fibrinoid necrosis and vascular thrombosis. Massive periarterial accumulations of inflammatory cells were common and often extended into adjacent tissues. The small- to medium- sized muscular arteries of the heart, cranial mediastinum, and cervical spinal meninges were consistently involved. Vasculitis occasionally occurred in other organ systems. The vascular lesions in dogs examined during clinically normal periods consisted of intimai and medial fibrosis, ruptured elastic laminae, and mild perivasculitis; these lesions were probably related to previous episodes of vasculitis. Eight dogs that had experienced repeated acute episodes also developed splenic, hepatic, and renal amyloidosis. The clinical signs, laboratory abnormalities, and the vascular lesions suggest that the condition may be immune-system mediated. CJPS may serve as a naturally occurring animal model of human immune-system-mediated vasculitides such as polyarteritis nodosa, infantile polyarteritis, and Kawasaki disease.
Clinical and Clinical Laboratory Correlates in Sea Otters Dying Unexpectedly in Rehabilitation Centers Following the Exxon Valdez Oil Spill
Authors: Rebar A. H. , Lipscomb T. P. , Harris R. K. , Ballachey B. E.
Published: January 2010

Following the Exxon Valdez oil spill, 347 oiled sea otters ( Enhydra lutris) were treated in rehabilitation centers. Of these, 116 died, 94 within 10 days of presentation. Clinical records of 21 otters dying during the first 10 days of rehabilitation were reviewed to define the laboratory abnormalities and clinical syndromes associated with these unexpected deaths. The most common terminal syndrome was shock characterized by hypothermia, lethargy, and often hemorrhagic diarrhea. In heavily and moderately oiled otters, shock developed within 48 hours of initial presentation, whereas in lightly oiled otters shock generally occurred during the second week of captivity. Accompanying laboratory abnormalities included leukopenia with increased numbers of immature neutrophils (degenerative left shift), lymphopenia, anemia, azotemia (primarily prerenal), hyperkalemia, hypoproteinemia/hypoalbuminemia, elevations of serum transaminases, and hypoglycemia. Shock associated with hemorrhagic diarrhea probably occurred either as a direct primary effect of oiling or as an indirect effect secondary to confinement and handling in the rehabilitation centers. Lightly oiled otters were less likely to die from shock than were heavily oiled otters (22% vs. 72%, respectively). Heavily oiled otters developed shock more rapidly and had greater numbers of laboratory abnormalities, suggesting that exposure to oil was an important contributing factor.
A New Inherited Muscular Disorder in Japanese Quails (Coturnix coturnix japonica)
Authors: Braga I. S. , Oda K. , Kikuchi T. , Tanaka S. , Shin Y. , Sento M. , Itakura C. , Mizutani M.
Published: January 2010

Thirteen adult mutant (LWC strain) Japanese quails ( Coturnix coturnix japonica), between the ages of 8 and 60 weeks were examined for a progressive muscular disorder. The disorder, inherited as an autosomal dominant trait, was clinically apparent as early as 28 days of age; it was characterized by generalized myotonia, muscle stiffness, and muscle weakness. Affected birds were identified by their inability to lift their wings vertically upward and by their inability to right themselves when placed on their dorsum. Electromyographic studies in two mutant quails showed high-frequency repetitive discharges comparable to those of myotonic runs. These discharges persisted after nerve resection. The distinctive histopathologic changes in the various muscles examined were ring fibers, sarcoplasmic masses, and internal migration of sarcolemmal nuclei. A slight decrease in the size of type IIB muscle fibers and a slight increase in the size of type IIA fibers were observed in the M. pectoralis thoracicus of affected quails. In older affected birds, inter- and intrafascicular fatty infiltration with replacement of type IIB fibers by fat cells was seen in the pectoral muscles. Single fiber necrosis, nonspecific lymphorrages, and variations in the muscle fiber size and shape were also noted. The typical muscle lesions and multisystem involvement, which was manifested by testicular degeneration and atrophy in the male LWC specimens and bilateral lenticular cataracts in 6 of 13 affected mutant quails, suggest resemblance of this new inherited muscular disorder to myotonic dystrophy in man.
Pathogenesis of Porcine Reproductive and Respiratory Syndrome Virus Infection in Gnotobiotic Pigs
Authors: Rossow K. D. , Collins J. E. , Goyal S. M. , Nelson E. A. , Christopher-Hennings J. , Benfield D. A.
Published: January 2010

The pathogenesis of porcine reproductive and respiratory syndrome virus (PRRSV) was determined in gnotobiotic pigs by studying the sequential development of microscopic lesions and sites of virus distribution and replication. Thirty-two pigs (three pigs/infected group and one pig/control group) were inoculated by nasal instillation of either PRRSV isolate ATCC VR-2332 (total dose 102,6TCID50) or uninfected cell culture supernatant. Infected and control pigs were euthanized at 12 hours, and 1, 2, 3, 5, 7, 14, and 21 days postexposure (PE). Gnotobiotic pigs experimentally infected with PRRSV were viremic by 12 hours PE and subsequently developed pneumonia, lymphadenopathy, vasculitis, myocarditis, and encephalitis. Lung lesions developed by day 3 PE, persisted through day 21 PE and were characterized by alveolar septa thickened by macrophages, alveolar proteinaceous and karyorrhectic debris, alveolar syncytial cells, and multifocal type II pneumocyte hypertrophy. Lymph node lesions varied in distribution and severity and were characterized by germinal center hypertrophy and hyperplasia, lymphocyte necrosis, multiple cystic spaces, and polykaryocytes within the cystic spaces. Heart lesions were a late feature of infection and all infected pigs had heart lesions on day 21 PE characterized by subendocardial, myocardial, and perivascular foci of lymphocytes. Vasculitis also varied in distribution and severity and affected all sizes of vessels. Results of this experiment indicate that PRRSV is a multisystem disease characterized initially by viremia with subsequent virus distribution and replication in multiple organs causing interstitial pneumonia, vasculitis, lymphadenopathy, myocarditis, and encephalitis.
Antibodies to Canine Granulocyte Colony-stimulating Factor Induce Persistent Neutropenia
Authors: Reagan W. J. , Murphy D. , Battaglino M. , Bonney P. , Boone T. C.
Published: January 2010

A severe persistent neutropenia developed in a rabbit that was injected intradermally with 120, 60, 60, and 120 μg of recombinant canine granulocyte colony-stimulating factor (cG-CSF) on days 1, 22, 31, and 44, respectively. The neutropenia was present from day 44 to day 205. The nadir of the neutropenia (60 cells/μl) occurred in conjunction with peak antibody titer (640,000) to cG-CSF on day 58. The immune antiserum from this rabbit reacted positively for cG-CSF on Western blot analysis. The immune antiserum also neutralized the activity of cG-CSF. On day 160, examination of the bone marrow showed marked granulocytic hypoplasia and mild erythroid hyperplasia. On day 205, the rabbit was still neutropenic (430 cells/μl), even though the last injection of cG-CSF was given 161 days previously. Necropsy on day 205 showed that there was still mild granulocytic hypoplasia with mild erythroid hyperplasia. Because of the lack of any inflammatory foci found at necropsy and the granulocytic hypoplasia, it was thought that the neutropenia was most likely due to decreased production and was not a consumptive process. It is hypothesized that the antibody that was produced to cG-CSF neutralized the effect of endogenous rabbit granulocyte colony-stimulating factor and prevented the normal proliferation and maturation of the rabbit neutrophils.
Preneoplastic and Neoplastic Lesions of Rat Hereditary Renal Cell Tumors Express Markers of Proximal and Distal Nephron
Authors: Wolf D. C. , Whiteley H. E. , Everitt J. I.
Published: January 2010

Long-Evans (Eker) rats carry a mutation that predisposes them to develop spontaneous renal cell tumors of two morphologic patterns: solid chromophilic masses or cystic lesions lined by eosinophilic cells. Previous studies have suggested that these tumors arise from the proximal tubules. In the present study, lectin-binding characteristics and cytokeratin expression of various stages of hereditary rat renal epithelial neoplasia were examined to localize the portion of the nephron from which tumors arise. Lectin-binding histochemistry has been used as a marker of cell surface glycoprotein expression, thought to be important in the differentiation of benign from malignant epithelial lesions and in the determination of their cell of origin. The presence or absence of keratin intermediate filaments in the rat nephron has been used to identify nephron segments. The polyclonal antibody to high- and low-molecular-weight cytokeratin stained the cells of the collecting ducts but not the proximal or distal tubules. Binding to the proximal tubules by the lectins Conavalia ensiformis (Con A), Dolichas biflorus, Ricinus communis (RCA-1), and Triticum vulgare and to the distal tubules by Con A, RCA-1, Arachis hypogaea (PNA) with and without neuraminidase, and the antibody for cytokeratins was demonstrated. The lectin binding and cytokeratin staining patterns of rat hereditary renal cell carcinoma, adenoma and the preneoplastic lesions of atypical tubules and hyperplasias suggest that cystic adenomas arise from the distal nephron, principally the collecting duct, whereas the solid atypical tubules, hyperplasias, and adenomas arise from the proximal nephron, principally the proximal tubule.
Canine Bullous Pemphigoid (BP): Identification of the 180-kd Canine BP Antigen by Circulating Autoantibodies
Authors: Iwasaki T. , Olivry T. , Lapiere J. C. , Chan L. S. , Peavey C. , Liu Y. Y. , Jones J. C. R. , Ihrke P. J. , Woodley D. T.
Published: January 2010

Human bullous pemphigoid (BP) is an immune-mediated blistering disease characterized by autoantibodies against BP antigens (230/180 kd), which are constitutive glycoproteins of hemidesmosomes found in basal keratinocytes. Blistering diseases similar to human BP have been reported in dogs. IgG deposits at the basement membrane zone (BMZ) are a common feature of canine BP. Although circulating anti-BMZ IgG autoantibodies have been demonstrated in some cases of canine BP, the specific skin protein targeted by these autoantibodies has not been identified. In this study, we characterized the antigenic target of the autoantibodies in the serum from a 3-year-old castrated male Pit Bull Terrier with BP. Direct immunofluorescence of the patient's skin demonstrated IgG deposits at the dermal-epidermal junction. Indirect immunofluorescence demonstrated autoantibodies in the patient's serum that stained the epidermal roof of salt-split canine skin and left the dermal floor unstained. These serum autoantibodies did not stain normal intact dog skin but labeled intact bovine tongue. Direct immunoelectron microscopy of the dog's skin revealed IgG deposits within the hemidesmosomes of the basal keratinocytes. Western immunoblotting experiments showed that canine keratinocytes express both the 230-kd and 180-kd bullous pemphigoid antigens, and the autoantibodies from the patient's serum recognized the 180-kd bullous pemphigoid antigen in proteins extracted from canine and human keratinocytes. Canine BP has many parallel features with human BP including similar immune deposition of IgG within hemidesmosomes and a hemidesmosome-associated 180-kd glycoprotein target for circulating autoantibodies.
Toxic Effects of Butylated Triphenyl Phosphate-based Hydraulic Fluid and Tricresyl Phosphate in Female F344 Rats
Authors: Latendresse J. R. , Brooks C. L. , Capen C. C.
Published: January 2010

Triaryl phosphates, including tricresyl phosphate (TCP) and butylated triphenyl phosphates (BTP), are used in the commercial manufacture of plastics, lubricants, and hydraulic fluids. Recent reports implicate these compounds as endocrine and reproductive toxicants that can cause cholesteryl lipidosis in adrenocortical (AC) and ovarian interstitial (OI) cells, suggesting altered metabolism of steroid hormones or cholesterol or of both. We investigated potential mechanisms of BTP and TCP toxicity to determine if there were functional abnormalities of the adrenal cortex or ovary. Groups of intact (nine or 12) and ovariectomized (six) female F344 rats, 10-12 weeks of age, received 0, 0.4 g/kg TCP, or 1.7 g/kg BTP in sesame oil vehicle or 1.7 g/kg neat BTP for 20, 40, or 60 days. All rats administered BTP and TCP developed cholesteryl lipidosis in AC and OI cells; the TCP-treated group was most severely affected. Serum concentrations of androstenedione and corticosterone were unchanged, but estradiol levels were significantly ( P < 0.05) elevated in BTP- and TCP-treated groups (14.5 times and 37.5 times greater than controls, respectively). Vaginal cytology revealed that BTP- but not TCP-treated females had abnormal reproductive cycles that were significantly prolonged in diestrus (3 times greater than control). There were significant elevations in serum total cholesterol (TCP-treated group was 1.3 times greater than controls), low-density lipoprotein (TCP-treated group was 1.8 times greater than controls), alanine transaminase (BTP-treated group was 2 times greater than controls), and albumin (a major serum estradiol-binding protein; BTP-treated group was 4.6 g/dl vs. 3.6 g/dl for controls). Liver weights (134% that of controls) and P-450 enzymes (3 times greater than controls) were significantly increased in BTP-treated rats. Abnormal reproductive cycles, elevated serum albumin, and increased hepatic P-450 concentration suggested fecundity could be affected in female rats exposed to BTP, most likely because of altered liver metabolism. Ovariectomized BTP-treated and control rats had similarly increased uterine weights after challenge with estradiol and estradiol benzoate, indicating that triaryl phosphate-induced esterase inhibition or other xenobiotic-induced block of hormone action in estradiol-responsive tissues was not responsible for the prolonged diestrus in rats with elevated serum estradiol. The pathogenesis of the cholesteryl lipidosis induced by TCP and BTP appeared to be separate from the reproductive effects because the lipidosis was most severe in TCP-treated rats, which had normal reproductive cycles and fertility.
Endothelial MHC Class II Antigen Expression and Endarteritis Associated with Marek's Disease Virus Infection in Chickens
Authors: Kariuki Njenga M. , Dangler C. A.
Published: January 2010

Experimental Marek's disease virus (MDV) infection in chickens was used to study the early pathogenesis of virus-induced atherosclerosis. Previous investigations using this model have reported the occurrence of atherosclerotic lesions after approximately 7 months postinfection. In this study, a total of 75 susceptible Cornell P-line chickens were inoculated intraperitoneally with the CU-2 strain of MDV at 3 days of age and subsequently perfused for histologic examination. At 2, 4, 8, 13, and 20 weeks postinoculation, the ascending aorta and the brachiocephalic and coronary arteries were evaluated for early changes. Expression of class II major histocompatibility complex (Ia) antigen by the vascular endothelium was demonstrated by indirect immunodetection as early as 2 weeks after virus inoculation. This change was followed by significant thickening of the intimai layer associated with mononuclear cell infiltration. All the arteries examined from the MDV-infected chickens were affected. Preliminary immunohistochemical staining showed the presence of CD3+ CD4+, and CD8+ cells among the infiltrating cells. The results suggest that an immunopathologic mechanism may be involved in the early pathogenesis of MDV-induced atherosclerosis in chickens.
Senile Plaques and Other Senile Changes in the Brain of an Aged American Black Bear
Authors: Uchida K. , Yoshino T. , Yamaguchi R. , Tateyama S. , Kimoto Y. , Nakayama H. , Goto N.
Published: January 2010

A female American black bear ( Euarctos ursus americanus) over 20 years old had shown epileptiform neurologic signs starting in March 1992 and was found dead unexpectedly 8 months later. At necropsy, pulmonary and intrabronchial hemorrhage was noted. In the brain, the leptomeninges exhibited slight thickening, and petechiae were evident in the hippocampus. Histopathologic examination of the brain revealed several senile changes: numerous senile plaques, amyloid deposition in cerebromeningeal arterioles, mineral deposition in the pallidum, and numerous corpora amylacea in the cerebellum.
Biliary Cystadenoma of Cats
Authors: Adler R. , Wilson D. W.
Published: January 2010

Published surveys of feline neoplasia have not specifically included biliary cystadenoma, and there is only one case report in the literature. This report is a compilation of 13 feline cases and provides a description of clinical, pathologic, immunohistochemical, and ultrastructural aspects of biliary cystadenoma as well as a discussion of comparative pathology of biliary cystadenoma in human beings and speculative histogenesis.
Spontaneous Renal Tubular Carcinoma in Fischer-344 Rat Littermates
Authors: Thurman J. D. , Hailey J. R. , Turturro A. , Gaylor D. W.
Published: January 2010

Two of 632 Fischer-344 rats in a food restriction study had spontaneous, bilateral, multicentric renal tubular cell carcinomas. Although there were 104 litters represented in this study, both rats that developed this rare neoplasm were from the same litter. The littermates, one male and one female, were in the food-restricted treatment groups (60% of ad libitum intake) and were 550 and 447 days old, respectively, at death. The probability that the two rare bilateral renal neoplasms occurred by a chance event in littermates is approximately 0.8%. The apparent familial predisposition for development of specific types of neoplasms emphasizes the importance of randomization of individuals into treatment groups and consideration of lineage for rare tumors.
Primary Gastrointestinal Lymphosarcoma with Epitheliotropism in Three Shar-Pei and One Boxer Dog
Authors: Steinberg H. , Dubielzig R. R. , Thomson J. , Dzata G.
Published: January 2010

Three male Shar-pei dogs and one female spayed Boxer dog ranging in age from 4 years, 4 months to 7 years, 8 months had 4-7-week histories of diarrhea, progressive anorexia, weight loss, and vomiting. The dogs were depressed, lethargic, and hypoalbuminemic, with losses of 23-39% of body weight. Endoscopic examination revealed gastric ulceration with areas of mucosal hyperemia and pallor. Small nodules with occasional central depressions were present in three dogs. Gastric and proximal duodenal mucosal biopsies showed neoplastic lymphocytes infiltrating the lamina propria, with invasion of the superficial and glandular epithelial basement membrane. Immunohistochemical evaluation of two dogs was negative for anti-canine IgG and positive for anti-CD3. Necropsy of the Boxer and two Shar-peis confirmed epitheliotropic gastric and small intestinal lymphoma in all three dogs, with mesenteric lymph node and hepatic involvement in two and one dog, respectively.
Hepatopathy Associated with Excessive Hepatic Copper in a Siamese Cat
Authors: Haynes J. S. , Wade P. R.
Published: January 2010

A 2-year-old spayed female Siamese cat was presented with clinical liver disease characterized by anorexia; depression; elevations in serum levels of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase; hyperbilirubinemia; and icterus. Liver biopsy diagnosed hepatocellular degeneration with marked centrilobular hepatocellular accumulation of rhodanine-positive brown granules. Subsequent postmortem examination revealed similar granular material in the epithelium of the proximal convoluted tubules and collecting ducts of the kidney and alveolar epithelium and macrophages in the lung. The liver and kidney copper concentrations were 4,074 and 792 ppm dry weight, respectively. Hepatic degeneration in this cat apparently was due to excessive accumulation of copper.
Epithelioma of the Fourth Ventricle in a Goat
Authors: Wicks J. R. , Oglesbee M. J.
Published: January 2010

We describe an epithelial neoplasm arising from the fourth ventricle of a goat and extending into the subjacent cerebellum along the spaces of Virchow-Robin. The neoplastic cells are consistent with squamous epithelium based upon light microscopic morphology and cytokeratin immunoreactivity. The lack of overt keratin formation and the lack of an exophytic component distinguishes this neoplasm from intracranial epidermoid cysts, resulting in the classification of this caprine tumor as an epithelioma.
Disseminated Adenovirus Infection Associated with Cutaneous and Visceral Hemorrhages in a Nursing Piglet
Authors: Tang K. N. , Baldwin C. A. , Mansell J. L. , Styer E. L.
Published: January 2010

An unusual adenovirus infection in a conventionally raised nursing pig was characterized clinically by hemorrhagic diathesis of the skin and microscopically by disseminated viral inclusions in the endothelial, interstitial, and epithelial cells of the skin, kidney, spleen, liver, heart, and small and large intestines. This disease was confirmed ultrastructurally by demonstration of typical adenoviral particles in the nuclei of endothelial cells in the myocardium and of interstitial cells in the small intestine. This is the first report of disseminated adenovirus infection in a nursing pig in North America.
Extramedullary Hematopoiesis in the Choroid Plexus of Five Dogs
Authors: Bienzle D. , Kwiecien J. M. , Parent J. M.
Published: January 2010

Five dogs euthanatized because of refractory seizures were found to have hematopoietic elements in the interstitium of the choroid plexus at the level of the fourth ventricle. None of the dogs had significant hematologic or cerebrospinal fluid abnormalities. The extramedullary hematopoiesis was confined to the central nervous system and consisted of megakaryocytes, immature granulocytes, and rubricytes in two dogs and of one predominant cell population in each of the other three dogs. These findings are unique, and factors possibly contributing to the formation of a hematopoietic inductive microenvironment in the choroid plexus are cytokine-neurokine homologies, locally altered vascular supply, and aberrant functioning of bone marrow-derived central nervous system macrophages.
Fibrosarcomas in Two Rats Arising from Hepatic Cysts of Cysticercus fasciolaris
Authors: Hanes M. A.
Published: January 2010

Two of five male Sprague-Dawley rats with hepatic tapeworm cysts developed large multinodular fibrosarcomas. Fibrosarcomas enveloped tapeworm cysts, invaded the serosa of multiple organs, and extended through the diaphragm into the pleural cavity. Light microscopy, immunohistochemistry, and electron microscopy supported the diagnosis of fibrosarcoma. The parasites were identified as Cysticercus fasciolaris, the larval stage of Taenia taeniaeformis. The development of sarcomas in rats induced by Taenia sp. is thought to be attributable to the chronic inflammatory reaction of the capsule. There are parallels between these and other tumors occurring in mice and cats with suggested chronic inflammatory etiologies.
Diagnosis of Naturally Occurring Bovine Viral Diarrhea Virus Infections in Ruminants Using Monoclonal Antibody-based Immunohistochemistry
Authors: Baszler T. V. , Evermann J. F. , Kaylor P. S. , Byington T. C. , Dilbeck P. M.
Published: January 2010

Formalin-fixed paraffin-embedded tissues from 50 spontaneous cases (39 bovine, nine ovine, two caprine) of bovine viral diarrhea virus (BVDV) infection diagnosed by virus isolation were retrospectively examined for BVDV antigen by immunohistochemistry using anti-BVDV gp-43 monoclonal antibody (Mab 15C5). The cases were separated into enteric disease syndrome, respiratory disease syndrome, and abortion/weak calf syndrome based upon clinical disease. The purposes of the study were to 1) compare routine virus isolation with immunohistochemistry in determining BVDV infection and 2) define tissue and cellular distribution of BVDV in various clinical manifestations of infection. In bovids, there was 100% concordance of virus isolation and immunohistochemistry using Mab 15C5 in cases of enteric disease (mucosal disease, acute and chronic diarrhea, neonatal diarrhea), respiratory disease, and abortion. When laboratory tests were restricted to gastrointestinal tissue and/or feces, virus isolation detected BVDV in only 65% of cattle, whereas immunohistochemistry detected BVDV antigen in 100% of cattle. Immunohistochemical detection of pestivirus was poor in cases of ovine abortion, ovine hairy shaker syndrome, and caprine abortion. The tissue distribution of BVDV antigen was widespread in individual cattle with all clinical forms of BVDV infection. Viral antigen accumulation was spatially correlated with tissue lesions (in the absence of other pathogens) only in the gastrointestinal tract, lymphoid tissue, lung, placenta, and eye. This study demonstrates the utility of immunohistochemistry using Mab 15C5 to diagnose BVDV infections in cattle with a broad spectrum of clinical disease.
The Lesions of Rotavirus Infection in 1- and 10-day-old Gnotobiotic Calves
Authors: Varshney K. C. , Bridger J. C. , Parsons K. R. , Cook R. , Teucher J. , Hall G. A.
Published: January 2010

Age-related resistance to rotavirus disease has been described with some rotaviruses. In the present study, we investigated age-related resistance to rotavirus disease by defining extent of intestinal infection, virus replication, and severity of intestinal lesions in groups of three 1- and 10-day-old gnotobiotic calves of mixed breed inoculated orally with a cloned bovine rotavirus of low virulence for calves (strain C3-160) and in two groups of three uninoculated control calves of mixed breed. One-day-old calves inoculated with rotavirus developed diarrhea 26 hours after inoculation, and their feces contained 108.5-109.2 TCID50/g feces; inoculated 10-day-old calves did not develop diarrhea, virus excretion commenced on the second or third day after inoculation, and peak concentrations of virus in feces were 105.7-107.9 TCID50/g feces. Calves were euthanatized within 8-30 hours after the attainment of peak virus shedding while they were still shedding virus at peak levels. The mean percentage of small intestinal epithelium that was immunostained for rotavirus was three times greater in 1-day-old calves than in 10-day-old calves, and the large intestine was infected more extensively in 1-day-old calves. Immunostaining for rotavirus was maximal in the mid small intestine. Staining of mucin was substantially less in the epithelium of the small intestines and colon of rotavirus-inoculated 1-day-old calves than in age-matched controls. The mean height of villi was reduced to approximately half that of controls in the mid and distal small intestine of rotavirus-inoculated 1-day-old calves and was unchanged in 10-day-old calves. Mean crypt cell production rates were greater than that in controls in both groups of rotavirus-inoculated calves, indicating increased enterocyte loss. Age-related resistance to disease was not due to an inability of rotavirus to infect and replicate in enterocytes with lethal effects but appeared to be associated with a slowing of the pathogenic process, which occurred because insufficient enterocytes became infected and destroyed for lesions to develop.
Histochemical Study of Cutaneous Mucins in Hypothyroid Dogs
Authors: Doliger S. , Delverdier M. , Moré J. , Longeart L. , Régnier A. , Magnol J. P.
Published: January 2010

A dermal mucinoisis, visualized as dermal alcianophilic material, is occasionally present in canine hypothyroidism (myxedema). Various histochemical reactions (alcian blue/periodic acid–Schiff [PAS], alcian blue at pH 2.6, alcian blue at pH 1.0, critical electrolytical concentrations with and without dimethylsulfoxide, differential hydrolysis by hyaluronidases) were performed on skin biopsies from six dogs (four females and two males ranging from 8 to 13 years) affected by hypothyroidism, all of them presenting dermal mucinosis in hematoxylin and eosin–stained sections. In these dogs, the only polysaccharide compound involved in the dermal mucinosis was hyaluronic acid. In this study, hyaluronic acid dermal deposits of hypothyroid dogs were significantly different from those of controls in subepidermal connective tissue and loose reticular connective tissue but not in periadnexal zones. We recommend the combined alcian blue/PAS reaction as a routine technique to assess dermal mucinosis in hypothyroid dogs.
The Lesions of Hepatic Fatty Cirrhosis in Sheep
Authors: Helman R. G. , Adams L. G. , Bridges C. H.
Published: January 2010

During a natural outbreak of hepatic fatty cirrhosis (HFC) in western Texas, 500 2-6-year-old Rambouillet ewe sheep were sequentially studied to determine the pattern of lesion development. All sheep developed lesions of HFC. Grossly, changes first began in the subcapsular hepatic parenchyma along the porta hepatis and spread peripherally until, in the final stages of the disease, approximately 80% of the liver was affected. Ascites, hydropericardium, and acquired hepatic vascular shunts were present in sheep with severe HFC. Light microscopic lesions initially appeared as accumulations of fine lipid droplets in the cytoplasm of periacinar hepatocytes but, with time, involved all hepatocytes of the lobule. The fat vacuoles in the periacinar hepatocytes coalesced to form larger vacuoles; and after rupture of adjacent fat-laden hepatocytes, fatty cysts appeared. Fibrosis began in the periacinar zone associated with the ruptured fatty cysts and continued until there was widespread bridging periacinar fibrosis. Islands of regenerating hepatocytes were frequently sequestered within the bands of fibrous tissue. Characteristically, the hepatic and posterior mediastinal lymph nodes, lung, and spleen contain ceroid. No lesions of hepatic encephalopathy were found in any animal. HFC is a progressive, chronic disease of sheep, and the morphology of the hepatic lesions is similar to lipotrope-deficient forms of nutritional cirrhosis. These findings are discussed in relation to similar nutritional deficiencies and toxicoses in sheep.
Osteochondrosis of the Articular-Epiphyseal Cartilage Complex in Young Horses: Evidence for a Defect in Cartilage Canal Blood Supply
Authors: Carlson C. S. , Cullins L. D. , Meuten D. J.
Published: January 2010

The objectives of this study were to determine in horses 1) the ages at which viable cartilage canal vessels are present in the articular–epiphyseal cartilage complex of three predilection sites and one nonpredilection site of osteochondrosis (OC), 2) the prevalence of lesions of OC in these sites, and 3) whether there was an association of lesions of OC with necrotic cartilage canal blood vessels. The medial femoral condyle, lateral femoral trochlear ridge, and distal ends of the tibia and proximal phalanx were examined grossly, microradiographically, and histologically in 35 horses 18 months old or younger. Cartilage canals containing patent blood vessels were present in all sites examined in foals less than 3 weeks old and were absent from all sites by 7 months of age. The overall prevalence of lesions of OC at one or more of the sites examined was 12/35 (34%). Prevalence increased to 11/22 (50%) in horses 2 months old and older. These lesions occurred primarily in the medial condyle of the femur ( n = 5) and the intermediate ridge of the distal tibia ( n = 5). All lesions seen in horses between 3 weeks and 5 months of age were associated with necrotic cartilage canal blood vessels. In horses 7 months of age and older, lesions of OC were considered chronic because of extensive involvement of the subchondral bone and bone marrow. These results suggest that OC lesions develop prior to 7 months of age and that ischemic necrosis of cartilage secondary to a defect in vascular supply is an important factor in the pathogenesis of this disease in horses.
Comparison of the Pathogenicity of Two US Porcine Reproductive and Respiratory Syndrome Virus Isolates with that of the Lelystad Virus
Authors: Halbur P. G. , Paul P. S. , Frey M. L. , Landgraf J. , Eernisse K. , Meng X.-J. , Lum M. A. , Andrews J. J. , Rathje J. A.
Published: January 2010

The Lelystad virus or one of two US isolates (VR2385, VR2431) of porcine reproductive and respiratory syndrome virus were given intranasally to 25 4-week-old cesarian-derived colostrum-deprived pigs. Pigs from these groups were necropsied at 1, 2, 3, 5, 7, 10, 15, 21, or 28 days postinoculation. The Lelystad virus and VR2431 induced mild transient pyrexia, dyspnea, and tachypnea. VR2385 induced labored and rapid abdominal respiration, pyrexia, lethargy, anorexia, and patchy dermal cyanosis. All three isolates induced multifocal tan-mottled consolidation involving 6.8% ( n = 9, SEM = 3.4) of the lung for Lelystad, 9.7% ( n = 9, SEM = 2.7) of the lung for VR2431, and 54.2% ( n = 9, SEM = 4.4) of the lung for VR2385 at 10 days postinoculation. Characteristic microscopic lung lesions consisted of type 2 pneumocyte hypertrophy and hyperplasia, necrotic debris and increased mixed inflammatory cells in alveolar spaces, and alveolar septal infiltration with mononuclear cells. Lymphadenopathy with follicular hypertrophy, hyperplasia, and necrosis was consistently seen. Similar follicular lesions were also seen in Peyer's patches and tonsils. Lymphohistiocytic myocarditis and encephalitis were reproduced with all three isolates. Clinical respiratory disease and gross and microscopic lung lesion scores were considerably and significantly more severe in the VR2385-inoculated pigs. All three viruses were readily isolated from sera, lungs, and tonsils throughout the 28 days of the study. The lymphoid and respiratory systems have the most remarkable lesions and appear to be the major site of replication of these viruses. This work demonstrated a marked difference in pathogenicity of porcine reproductive and respiratory syndrome isolates.
Comparative Severity of Respiratory Lesions of Sialodacryoadenitis Virus and Sendai Virus Infections in LEW and F344 Rats
Authors: Liang S.-C. , Schoeb T. R. , Davis J. K. , Simecka J. W. , Cassell G. H. , Lindsey J. R.
Published: January 2010

In several chronic diseases, lesions are more severe in LEW rats than in F344 rats. To determine whether or not acute viral diseases also are more severe in LEW rats than in F344 rats, we inoculated 6-7-week-old LEW and F344 rats with 107.2cell culture infective units of sialodacryoadenitis virus or 104.7infective units of Sendai virus. Twenty-four rats of each strain were given each virus. Lesions in nasal passages, tracheas, intrapulmonary airways, and pulmonary alveoli in 6 or 12 rats inoculated with each virus were assessed by scoring 5, 10, and 14 days after inoculation. Both viruses caused typical patchy necrotizing rhinitis, tracheitis, bronchitis, and bronchiolitis, with multifocal pneumonitis, in rats of both strains. Mean lesion indices for LEW rats given sialodacryoadenitis virus were significantly different from those for F344 rats for nasal passages on days 10 (0.999 vs. 0.680) and 14 (0.736 vs. 0.278), bronchi on day 5 (0.479 vs. 0.361), and alveoli on day 5 (0.677 vs. 0.275). Lesion indices for LEW rats given Sendai virus were significantly different from those for F344 rats for nasal passages on days 10 (1.000 vs. 0.611) and 14 (0.778 vs. 0.583); trachea on day 10 (0.625 vs. 0.028); bronchi on days 5 (0.476 vs. 0.331), 10 (0.123 vs. 0.013), and 14 (0.038 vs. 0); and alveoli on days 5 (0.413 vs. 0.114) and 10 (0.18 5 vs. 0.020). Thus, at the tested doses, both viruses caused more severe respiratory tract lesions in LEW rats than in F344 rats.
Lectin Histochemistry and Carcinoembryonic Antigen in Spontaneous Colonic Cancers of Cotton-top Tamarins (Saguinus oedipus)
Authors: Brack M.
Published: January 2010

The glycoconjugate-binding properties and the expression of carcinoembryonic antigen in colonic cancers of cotton-top tamarins at the German Primate Center are described. Deviating from findings in non-tumorous colonic epithelia of cotton-top tamarins was the presence of UEA-, SBA-, or DBA-binding sites in the infranuclear cytoplasm of colonic epithelial cells, staining of entire cells, and the occurrence of subepithelial extracellular glycoconjugates in and adjacent to colonic cancers. Carcinoembryonic antigen, which normally was limited to the fuzzy coat of the colonic epithelium, was demonstrated in the cytoplasm of the cancer cells.
Reduced Physeal Area and Chondrocyte Proliferation inPasteurella multocidaToxin-treated Rats
Authors: Ackermann Mark R. , Stabel Judith R. , Pettit Robin K. , Jacobson Carol D. , Elmquist Joel K. , Register Karen B. , Rimler Richard B. , Hilton Jana H.
Published: January 2010

Pasteurella multocida toxin depresses weight gain in rats and pigs. It also affects tissues with rapidly dividing cells. In the present study, we investigated the role of this protein toxin on chondrocyte growth in vivo. Rats were divided into a single- or multiple-dose group and were given, respectively, either a single injection (0.15 or 0.6 μg/kg toxin subcutaneously) or multiple injections (0.01-0.2 μg/kg subcutaneously) of toxin. Bone (humerus) and other selected tissues were stained for bromodeoxyuridine immunoreactivity (BrDU-IR) in order to gauge cell proliferation. Physeal area was measured in rats from the multiple-dose group. Serum from single-and multiple-dose groups were tested for tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) activity using a bioassay system. Decreased weight gain, feed intake, and feed efficiency were observed in single- and multiple-dose groups of rats. Decreased BrDU-IR indices were present in the resting and proliferative zone chondrocytes of the humeral physis in rats from the multiple-dose group, as was decreased physeal area. Increased serum IL-6 bioactivity was present in rats after 24 hours, and no changes in TNF-α bioactivity were seen in any group. No alterations in BrDU-IR were seen in rats fed restricted (80% of control) diets. These studies show that sublethal doses of toxin decrease weight gain and affect growth of long bones through suppression of chondrocyte proliferation. These effects may be mediated by direct binding of the toxin to target cells or IL-6 but are not associated with altered feed intake or TNF-induced cachexia.
Phenotypic Analysis of Neoplastic Cells from Calf, Thymic, and Intermediate Forms of Bovine Leukosis
Authors: Asahina M. , Kimura K. , Murakami K. , Ajito T. , Wu D. , Goryo M. , Aida Y. , Davis W. C. , Okada K.
Published: January 2010

Immunohistochemistry and flow cytometric analysis were used with monoclonal antibodies to examine the phenotype of neoplastic cells from cattle with sporadic bovine leukosis (three cases of calf form, two cases of thymic form, and three cases of intermediate form). Three cases of calf form and two cases of intermediate form were positive for B cell lineage in immunohistologic examination and in flow cytometric analysis for B-B2+, sIgM+, and major histocompatibility class II+. Two cases of thymic form and one case of intermediate form were CD2+, CD5+, CD6+, and CD8+ in immunohistologic examination and in flow cytometric analysis. The results show that neoplastic cells develop from B and T cell lineages in sporadic bovine leukosis.
Immunohistochemical Distribution Pattern of Intermediate Filament Proteins in 50 Feline Neoplasms
Authors: de las Mulas J. Martín , de los Monteros A. Espinosa , Carrasco L. , van Niel M. , Fernández A.
Published: January 2010

Twenty-eight epithelial and 22 nonepithelial feline tumors were studied immunohistochemically. Epithelial tumors were 10 squamous cell carcinomas, two basal cell tumors, two sebaceous gland carcinomas, three apocrine gland carcinomas, three thyroid papillary carcinomas, one thyroid solid carcinoma, one renal clear cell carcinoma, one renal papillary carcinoma, one endometrial carcinoma, and four lung bronchioloalveolar carcinomas. Nonepithelial tumors were 10 fibrosarcomas, one liposarcoma, one leiomyosarcoma, one rhabdomyosarcoma, one hemangiosarcoma, two mast cell tumors, one osteosarcoma, three melanomas, and two lymphomas. Commercially available antibodies directed against high- and low-molecular-weight keratins (keratin, RCK-102, NCL-5D3), vimentin, desmin, glial fibrillary acidic protein (GFAP), and neurofilament intermediate filament (IF) proteins were used in the avidin—biotin–peroxidase complex technique on formalin-fixed, paraffin-embedded tumor tissue samples. All epithelial tumors except the endometrial carcinoma expressed some type of keratin protein. Squamous cell carcinomas expressed high-molecular-weight keratins exclusively. Coexpression of high- and low-molecular-weight keratins was observed in one basal cell tumor, sebaceous and apocrine adenocarcinomas, and thyroid, renal, and lung carcinomas. In addition to keratins, vimentin immunoreactivity was found in all basal cell tumors, all sebaceous gland, thyroid papillary, renal, and lung adenocarcinomas, and one of the apocrine gland adenocarcinomas. Immunoreactivity with GFAP antibody was found in one basal cell tumor and one sebaceous gland adenocarcinoma. The endometrial carcinoma did not react with any of the antibodies applied. Nonepithelial tumors analyzed expressed either vimentin (fibrosarcomas, liposarcoma, haemangiosarcoma, mast cell tumors, osteosarcomas, melanomas) or vimentin and desmin (leiomyosarcoma, rhabdomyosarcoma, one fibrosarcoma) IF proteins exclusively. Lymphomas did not react with any of the antibodies employed. These findings indicate that IF proteins antibodies can be included in diagnostic panels of antibodies for immunocharacterization of feline tumors. In addition, they can be used as a basis for the diagnoses of poorly differentiated or undifferentiated feline neoplasms.
Histologic and Immunocytochemical Characterization of Canine Distemper-associated Metaphyseal Bone Lesions in Young Dogs Following Experimental Infection
Authors: Baumgärtner W. , Boyce R. W. , Weisbrode S. E. , Alldinger S. , Axthelm M. K. , Krakowka S.
Published: January 2010

The proximal metaphyses of the humerus of weanling gnotobiotic dogs experimentally infected with canine distemper virus (CDV) were investigated histologically and immunocytochemically between 4 and 41 days after infection. Viral antigen was demonstrated in hematopoietic marrow and bone cells at postinfection day (PID) 5 and PID 7, respectively. Between PID 8 and 27, CDV antigen was abundantly present in marrow cells, osteoclasts, and osteoblasts and less frequently in osteocytes. Immunopositive cells in both osseous tissues and bone marrow declined between PID 29 and PID 36 and were absent by PID 41. Chondrocytes of the growth plate were negative for viral antigen throughout the observation period. In bone, viral antigen was more frequently observed in bone cells of the primary spongiosa than in the secondary spongiosa. There was a strong correlation between occurrence of CDV antigen and osseous changes. Associated metaphyseal bone lesions were mild and most prominent between PID 8 and PID 32. Lesions consisted of necrosis of osteoclasts, which was associated with subsequent persistence of the primary spongiosa (growth retardation lattice). Atrophy and necrosis of osteoblasts and marrow cells were also noted. Infection of metaphyseal bone cells appears to be common in young dogs with experimental systemic distemper. Bone cell infection is preceded by infection of marrow cells, and infected bone cells may experience degeneration and necrosis. This subtle viral effect may result in defects in bone modeling in CDV-infected dogs.
Nasal Adenocarcinoma with Myoepithelial Component in a CD-1 Mouse
Authors: Chen H. C. , Pan I. Z. , Liang C. T. , Hong C. C.
Published: January 2010

Spontaneous nasal tumors are rare in mice, and only one adenocarcinoma and two more primary neoplasms of the nose have been observed in our files of long-term feeding studies, which are composed of 3,419 male and 3,521 female CD-1 (Cr1:CD-1® (ICR)BR) mice. This adenocarcinoma was a 1-cm-diameter mass observed grossly in the right nasal cavity of a 454-day-old, male CD-1 mouse from a treated group in a bioassay study conducted with 340 males and 340 females. The neoplastic epithelial cells affected the normal nasal architecture on the right side of the nose. Roughly, tumor neoplastic cells of the outer, lateral portion occurred as cuboidal to low columnar cells with basilarily located nuclei and eosinophilic cytoplasm. These cells were arranged in cylindrical profiles and frequently entrapped acini of the glands of the maxillary sinus. Neoplastic epithelial cells of the inner, medial portion appeared as serous acinar or ductular structures circumscribed by multiple lagers of myoepithelial-like cells. Staining failed to demonstrate mucous secretion. The site of origin of this neoplasm appeared to be the serous glands of the maxillary sinus. The adenocarcinoma was believed to be spontaneous.
Localized Retroperitoneal Fibromatosis Causing Intestinal Obstruction in a Cynomolgus Monkey (Macaca fascicularis)
Authors: Fikes J. D. , O'Sullivan M. G.
Published: January 2010

Gross examination of a 24-month-old, male cynomolgus monkey ( Macaca fascicularis) revealed obstruction of the ileum by a mass that entrapped and compressed the ileocecal junction. The mass was well circumscribed, firm, and white on cut surface. Histologically, the mass consisted of spindle-shaped cells arranged in interweaving bundles or as narrow cords and individual cells widely separated by dense collagen. A diagnosis of localized retroperitoneal fibromatosis was made based on the characteristic gross and microscopic findings and isolation of type D simian retrovirus, serotype-2, from spleen and mesenteric lymph node. Monkeys with localized retroperitoneal fibromatosis generally exhibit signs only of a palpable mass at the ileocecal junction and/or nonspecific diarrhea. This case represents an unusual presentation of localized retroperitoneal fibromatosis in which the lesion produced intestinal obstruction and death.