RESUMO
Recent "best practice" recommendations for peripheral nervous system sampling and processing provide guidance regarding nerve preparation for animal toxicity studies. This study explored the impact of delayed fixation, type of fixative, processing cycle times, starting ethanol concentration, and water bath temperature to improve nerve preservation in routinely prepared (paraffin-embedded, hematoxylin and eosin [H&E]-stained) sections. Sciatic nerves from adult Wistar rats (diameter, 1.04 ± 0.1 mm) and young domestic pigs (diameter 5.9 ± 1.2 mm) fixed at necropsy ("0" hours) or 3, 6, 12, or 24 hours after death were immersed in neutral-buffered 10% formalin containing 1.2% methanol (NBF) or methanol-free 4% formaldehyde (MFF) at room temperature. After fixation for 24 hours (rat) or 48 hours (pig), specimens were processed into paraffin, and â¼5-µm-thick sections were flattened on water baths set at 35°C, 40°C, or 45°C before H&E staining. Large-diameter nerves (pig) required longer processing cycles to ensure sufficient paraffin infiltration. For both small-diameter (rat) and large-diameter nerves, structural integrity was optimal if fixation by NBF or MFF occurred within 3 hours and the initial ethanol concentration for tissue processing was lowered to 50%. At all time points, structural preservation of nerve fibers was acceptable using NBF but was better with MFF. Use of a water bath at 35°C reduced processing-related nerve fiber separation within sections.
Assuntos
Nervo Isquiático , Fixação de Tecidos , Testes de Toxicidade , Animais , Fixadores , Formaldeído , Imuno-Histoquímica , Ratos , Ratos Wistar , Manejo de Espécimes , Suínos , ToxicologiaRESUMO
Clostridia represents a group of anaerobic spore-forming bacteria ubiquitous in the poultry environment. They are widely distributed in soil and survive for many years as highly resistant, inactive spores. They enter the body through wounds and contaminated feed as active bacteria or spores. Multiplication of clostridial bacteria occurs only in the absence of oxygen or in environments with very low concentrations of oxygen. During active multiplication, the clostridial organisms produce several toxins that are responsible for most of the clinical signs seen in clostridial diseases. Immunosuppression is a problem for the poultry industry. In modern, intensive poultry-rearing conditions, stress due to high population densities pose a considerable challenge for the immune system, and infectious agents can exploit this situation to cause disease. Immunosuppression may predispose turkeys to clostridial infection, resulting in clostridial dermatitis and mortality. The purpose of this study was to determine whether immunosuppression predisposes turkeys to clostridial infection and causes clostridial dermatitis. We immunosuppressed 10-wk-old turkey poults with dexamethasone. The birds immunosuppressed and not immunosuppressed were then challenged with Clostridium perfringens, Clostridium septicum, or both and examined for the development of clostridial dermatitis. The dexamethasone-treated birds were found to be more susceptible to C. peifingens/C. septicum challenge and developed clostridial dermatitis than the no-dexamethasone-treated birds through the subcutaneous route. However, oral inoculation of the same agents did not cause any dermatitis lesions in either of the groups.
Assuntos
Infecções por Clostridium/veterinária , Clostridium perfringens/fisiologia , Clostridium septicum/fisiologia , Dermatite/veterinária , Dexametasona/efeitos adversos , Imunossupressores/efeitos adversos , Doenças das Aves Domésticas/microbiologia , Perus/imunologia , Animais , Infecções por Clostridium/imunologia , Infecções por Clostridium/microbiologia , Dermatite/imunologia , Dermatite/microbiologia , Dexametasona/administração & dosagem , Terapia de Imunossupressão/efeitos adversos , Imunossupressores/administração & dosagem , Doenças das Aves Domésticas/imunologia , Perus/microbiologiaRESUMO
A 3-month-old male alpaca was presented for acute onset of non-weight-bearing left hind limb lameness. Antemortem diagnostics revealed a mass to the right of the urinary bladder and no blood flow in the left femoral artery. Necropsy revealed bilateral iliac arterial thrombi and an abscess near the urinary bladder.A 3-month-old male alpaca was presented for acute onset of non-weight-bearing left hind limb lameness. Antemortem diagnostics revealed a mass to the right of the urinary bladder and no blood flow in the left femoral artery. Necropsy revealed bilateral iliac arterial thrombi and an abscess near the urinary bladder.
RésuméThrombose artérielle iliaque bilatérale chez un petit alpaga(Vicugna pacos) . Un alpaga mâle âgé de 3 mois a été présenté pour l'apparition aiguë d'une boiterie du membre postérieur gauche sans appui de poids. Les tests diagnostiques avant le décès ont révélé une masse à la droite de la vessie et l'absence de débit sanguin dans l'artère fémorale gauche. La nécropsie a révélé des thrombi artérielles iliaques bilatérales et un abcès près de la vessie.(Traduit par Isabelle Vallières).
Assuntos
Abscesso/veterinária , Camelídeos Americanos , Artéria Ilíaca/patologia , Trombose/veterinária , Abscesso/diagnóstico , Animais , Animais Recém-Nascidos , Diagnóstico Diferencial , Evolução Fatal , Artéria Femoral/patologia , Coxeadura Animal/diagnóstico , Masculino , Trombose/diagnósticoRESUMO
Reported cases of herpesvirus-induced disease are uncommon in most species of reptiles, with the majority of reports in chelonians. Two monitor lizards (Varanus spp.) presented for postmortem examination at the Veterinary Medical Diagnostic Laboratory at the University of Missouri. Tan, 1-2-mm foci were grossly visible on the mucosal surface of the intestine and in the liver. Microscopically, there was multifocal necrosis in the lamina propria of the small intestine and in the liver. Many of the degenerate cells contained large, eosinophilic intranuclear inclusions. Enveloped icosahedral virions consistent with herpesvirus were detected by electron microscopy. A 180-bp DNA fragment was amplified by polymerase chain reaction from samples of small intestine and liver using primers that targeted a portion of the herpesvirus DNA polymerase gene. The sequence of the fragment was determined to be most closely related to Varanid herpesvirus 2 (80% nucleotide identity, 82% amino acid identity). Based on histological and molecular findings, a novel pathogenic herpesvirus of lizards in the family Varanidae is proposed.
Assuntos
Enterite/veterinária , Hepatite Viral Animal/virologia , Infecções por Herpesviridae/veterinária , Herpesviridae/classificação , Herpesviridae/isolamento & purificação , Lagartos , Sequência de Aminoácidos , Animais , Enterite/virologia , Regulação Viral da Expressão Gênica , Herpesviridae/genética , Infecções por Herpesviridae/virologia , Dados de Sequência Molecular , Filogenia , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
The role of Clostridium perfringens and Clostridium septicum in the development of cellulitis and mortality in turkey poults was examined. Studies were done in turkeys of two age groups: 3-wk-old and 7-wk-old turkey poults. The effect of varying doses of C. perfringens and C. septicum in reproducing cellulitis lesions and mortality in turkeys was investigated. Both in vitro and in vivo assays were conducted to study their toxic and biologic activities. Clostridium septicum spore culture was found to be more potent than that of C. perfringens in both in vitro assays, such as the hemolysis test, and in vivo assays in mice and turkeys. Both C. perfringens and C. septicum spore cultures were found to be capable of inducing cellulitis lesions and mortality in turkey poults when inoculated by subcutaneous route. Histopathology examination of affected tissues revealed a "moth-eaten appearance, with abundant growth of C. perfringens and C. septicum in the sarcomeres of muscle tissues and in the subcutaneous tissues. However, C. septicum was found to be more potent than C. perfringens in causing cellulitis lesions and mortality in turkeys. Three-week-old poults were found to be less susceptible than 7-wk-old poults in the development of cellulitis lesions and mortality after inoculation with either spore cultures of C. perfringens or C. septicum. The results of the current study suggest that although C. septicum is more potent in causing cellulitis lesions and mortality, infection with either C. septicum or C. perfringens can cause cellulitis lesions and mortality in turkeys.
Assuntos
Celulite (Flegmão)/veterinária , Infecções por Clostridium/veterinária , Clostridium perfringens , Clostridium septicum , Doenças das Aves Domésticas/microbiologia , Perus , Envelhecimento , Animais , Toxinas Bacterianas , Celulite (Flegmão)/microbiologia , Celulite (Flegmão)/patologia , Infecções por Clostridium/microbiologia , Infecções por Clostridium/patologia , Camundongos , Esporos BacterianosRESUMO
BACKGROUND: We previously demonstrated the ability of a human isolate of coxsackievirus-B5 (CVB5) to infect productively adult porcine islet cells (PICs) in vitro. PICs infected with CVB5 remain viable, and upon transplantation reversed diabetes in C56BL/6 mice for up to 5 days. METHODS: In the present work, we expanded this graft-to-host xenozoonosis model by examining the long-term functionality of CVB5-infected PIC xenografts in immunosuppressed mice. And, we characterized the pathogenesis of CVB5 infection in mice resulting from directional transmission of the virus from PIC xenografts to surrounding tissues in a mouse model for immunosuppressed human PIC xenograft recipients. RESULTS: Both acutely (12 h) and chronically (72 h) infected PIC xenografts functioned in vivo to reverse diabetes in mice. The efficacy of both infected and un-infected PICs was transient beyond 5 days post-inoculation and the long-term functionality of the grafts was compromised by host-to-graft rejection. CVB5-infected PIC xenografts transmitted infectious virus to immunosuppressed recipient mice resulting in extensive histopathologic changes. The virus replicated in the heart, liver, spleen, kidney, pancreas, brain and skeletal muscle in higher levels in severe-combined immunodeficient (SCID) mice that were directly inoculated with virus when compared to controls. In addition, infectious virus was recovered for up to 22 days after inoculation in SCID mice whereas it was only detected up to Day 4 PI in non-SCID mice. CONCLUSIONS: Immunosuppressed PIC xenograft recipients may be more susceptible to infection with CVB5 which could target the xenograft leading to disseminated infection in the host.
Assuntos
Infecções por Coxsackievirus/transmissão , Enterovirus Humano B/patogenicidade , Transplante das Ilhotas Pancreáticas , Transplante Heterólogo/efeitos adversos , Animais , Diabetes Mellitus Experimental/terapia , Enterovirus Humano B/metabolismo , Humanos , Transplante das Ilhotas Pancreáticas/efeitos adversos , Rim/citologia , Rim/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Suínos , Replicação ViralRESUMO
The objective of the present study was to compare the pathogenicity of early and recent isolates of avian metapneumovirus subtype-C (aMPV-C) in turkeys. Two-week-old turkeys were inoculated with early and recent isolates of aMPV-C. Clinical signs were monitored. Tissues were examined for viral ribonucleic acid (RNA), lesions, and viral antigen by reverse transcription-polymerase chain reaction (RT-PCR), histopathology and immunohistochemistry, respectively. Birds infected with the recent isolate had higher clinical sign scores than those infected with the early isolate. Only the recent isolate produced a multifocal loss of cilia in the nasal turbinate of infected birds. Immunohistochemistry revealed intense staining of aMPV antigen in turbinate and trachea of birds infected with the recent isolate. The findings indicate that the recent isolate produced more severe clinical signs and lesions in turkeys compared to the early isolate. The recent isolate could be ideal for the development of a challenge model for aMPV infection in turkeys.
Assuntos
Antígenos Virais/análise , Metapneumovirus/patogenicidade , Infecções por Paramyxoviridae/veterinária , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , RNA Viral/análise , Animais , Feminino , Imuno-Histoquímica/veterinária , Infecções por Paramyxoviridae/imunologia , Infecções por Paramyxoviridae/patologia , Infecções por Paramyxoviridae/virologia , Doenças das Aves Domésticas/imunologia , RNA Viral/genética , Distribuição Aleatória , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , PerusRESUMO
Five Japanese Black embryo transfer calves from a single embryo flush, 30 to 45-days-old, including 4 live animals for clinical examination and 1 dead for necropsy, were presented with a history of decreased milk intake and hypoproteinemia. Consistent clinicopathological abnormalities in the 4 calves presented for clinical evaluation included hyperkalemia, hyperphosphatemia, hypoproteinemia, hypoalbuminemia, hyperbilirubinemia, increased creatine phosphokinase activity, and proteinuria. Four calves ultimately were necropsied and all had histologic evidence of immune complex glomerulonephritis. Glomerulonephritis in these calves was hypothesized to have resulted from the interaction of passively acquired antibodies at birth and active immunization at 7 and 28 days of age with a Salmonella Typhimurium core antigen vaccine.
Assuntos
Doenças dos Bovinos/imunologia , Glomerulonefrite/imunologia , Animais , Bovinos , Doenças dos Bovinos/patologia , Doenças dos Bovinos/fisiopatologia , Glomerulonefrite/patologia , Glomerulonefrite/fisiopatologia , Imunização/efeitos adversos , Imunização/veterinária , Vacinas contra Salmonella/efeitos adversos , Vacinas contra Salmonella/imunologia , Salmonella typhimurium/imunologiaRESUMO
Between January 1 and December 31, 2005 gross and histologic examinations were performed on carcasses of 61 farm-raised white-tailed deer originating from Pennsylvania. Single-tube real-time reverse transcription polymerase chain reaction (real-time RT-PCR) for the detection of bovine viral diarrhea virus type 1 (BVDV-1) and type 2 (BVDV-2) was performed on each animal. Virus isolation was performed on tissue samples from 25 of 61 animals. Immunohistochemical (IHC) staining of ear-notch skin to identify BVDV antigen was performed on each animal. All tissues samples tested negative for both BVDV-1 and BVDV-2 by real-time RT-PCR, virus isolation, and IHC. Gross or histopathologic lesions suggestive of BVDV infection were not detected. Results of this study suggest that BVD is not a common cause of mortality in farm-raised white-tailed deer in Pennsylvania.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Cervos/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Animais , Animais Domésticos , Antígenos Virais/análise , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Vírus da Diarreia Viral Bovina/genética , Orelha/virologia , Feminino , Imuno-Histoquímica/veterinária , Masculino , Pennsylvania/epidemiologia , RNA Viral/química , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterináriaRESUMO
The necropsy records of 65 elk ranging from 1 day to 13(1/2) years of age were reviewed to determine the primary cause of death of each animal. The animal carcasses were submitted from 22 separate Pennsylvania elk farms over an approximately 8-year period. The most common causes of mortality in animals in which the cause of death was determined were gastrointestinal parasitism (21 cases), pneumonia (7 cases), enterocolitis (5 cases), malnutrition (5 cases), and rumenitis/acidosis (5 cases). The cause of death was undetermined in 4 of the 65 elk. Nematode organisms (20 cases) were the primary parasites identified in cases of mortality owing to gastrointestinal parasitism. Arcanobacterium pyogenes (3 cases), Escherichia coli (3 cases), and Streptococcus sp. (2 cases) were the most commonly isolated bacteria from the lung in the cases of pneumonia. Fungal organisms, consistent with Aspergillus sp. were present histologically within the pulmonary lesions in 5 cases. Bacterial agents associated with enterocolitis included Clostridium perfringens (2 cases), E. coli (1 case), Salmonella Newport (1 case) and Salmonella Thompson (1 case). The majority (56.3%) of the death loss in elk of known ages occurred in animals 1 year of age or less, with 71.4% of the gastrointestinal parasitism, 60.0% of the malnutrition, 60.0% of the enterocolitis, and 57.1% of the pneumonia cases occurring in animals within this age range. In conclusion, gastrointestinal parasitism, pneumonia, malnutrition, enterocolitis and rumenitis/acidosis were considered the most common causes of death in captive elk in this study.
Assuntos
Doenças dos Animais/mortalidade , Cervos , Acidose/veterinária , Animais , Animais Domésticos , Enterocolite/veterinária , Feminino , Enteropatias Parasitárias/veterinária , Masculino , Desnutrição/veterinária , Pennsylvania/epidemiologia , Pneumonia/veterinária , Estudos RetrospectivosRESUMO
Canine dysautonomia is a sporadic, generally fatal disease that rarely affects groups of related animals. Four 10-week-old Havanese puppies from a litter of 5 developed clinical signs of canine dysautonomia. The 4 affected dogs were exposed to an outdoor environment, whereas the fifth littermate was not exposed to the outdoors and remained clinically healthy. Clinical signs of dysautonomia developed 10-16 days after going outside the house. An unrelated dog also developed dysautonomia after exposure to 1 of the affected Havanese littermates. All 5 dogs had morphological changes consistent with dysautonomia (widespread neuronal degeneration in autonomic ganglia, select brainstem nuclei, and ventral horn motor neurons). Differential diagnoses were excluded through negative toxicological evaluation, fecal parasite screening, negative Canine distemper virus reverse transcription polymerase chain reaction, fluorescent antibody testing, attempted virus isolation, and electron microscopy. The 5 affected dogs were in the Kansas City, Missouri area, where there is a high incidence of dysautonomia.
Assuntos
Criação de Animais Domésticos , Vírus da Cinomose Canina/isolamento & purificação , Cinomose/diagnóstico , Disautonomias Primárias/veterinária , Animais , Animais Recém-Nascidos , Diagnóstico Diferencial , Cinomose/epidemiologia , Vírus da Cinomose Canina/genética , Cães , Meio Ambiente , Missouri/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Disautonomias Primárias/diagnóstico , Disautonomias Primárias/epidemiologiaRESUMO
Our earlier studies demonstrating avian pneumovirus (APV) RNA in wild geese, sparrows, swallows, starlings and mallard ducks suggested that wild birds might be involved in the circulation of APV in the United States. To determine whether turkey virus can be transmitted to the free flying birds, we placed APV-negative mallard ducks next to a turkey farm experiencing a severe APV outbreak and in an area with a large population of waterfowls. The sentinel ducks did not develop clinical APV disease but infectious APV (APV/MN-12) was recovered from choanal swabs after 2 weeks, and anti-APV antibodies detected after 4 weeks. Four APV isolates recovered from the neighboring turkeys that were experiencing an APV outbreak at the same time shared 95-99% nucleotide identity and 97-99% predicted amino acid identity with the duck isolate. In addition experimental infection of turkey poults with APV/MN-12 resulted in detection of viral RNA in nasal turbinates and APV-specific IgG in serum. These results indicate that the APV isolates from turkeys and ducks shared a common source, and the viruses from different avian species can cross-infect.
Assuntos
Doenças das Aves/virologia , Patos/virologia , Infecções por Pneumovirus/veterinária , Pneumovirus/genética , Perus/virologia , Sequência de Aminoácidos , Animais , Doenças das Aves/epidemiologia , Dados de Sequência Molecular , Filogenia , Pneumovirus/classificação , Pneumovirus/isolamento & purificação , Infecções por Pneumovirus/epidemiologia , Infecções por Pneumovirus/virologia , Homologia de Sequência de Aminoácidos , Estados Unidos/epidemiologiaRESUMO
The postmortem records of 160 white-tailed deer (Odocoileus virginianus) submitted for necropsy examination from 59 separate Pennsylvania captive deer farms over a 3.5-year period were reviewed to determine the primary cause of death of each animal. The most common causes of death were bronchopneumonia (39 cases), enterocolitis (30 cases), malnutrition (13 cases), and trauma (11 cases). Other causes of mortality included severe gastrointestinal parasitism (6 cases), cellulitis with septicemia (5 cases), degenerative myopathy (4 cases), ruminal acidosis (4 cases), and nephritis (4 cases). The cause of death was undetermined in 13 of the 160 animals. Arcanobacterium pyogenes (19 cases), Fusobacterium necrophorum (10 cases), Escherichia coli (7 cases), and Mannheimia haemolytica (4 cases) were the most commonly isolated bacteria from the pneumonic lungs. Bacterial agents associated with enterocolitis included Clostridium perfringens (15 cases), E. coli (12 cases), and Mycobacterium avium subsp. paratuberculosis (2 cases). The majority (52.2%) of the death loss in white-tailed deer of known ages occurred in animals 1 year of age or less, with 46.2% of the bronchopneumonia cases and 50.0% of the enterocolitis cases occurring during this time period. Cases of degenerative myopathy, myocardial degeneration, hepatic necrosis, meningoencephalitis, peritonitis, and urolithiasis considered severe enough to be the primary cause of death appeared early in life, affecting deer 6 months of age or less in all cases. In conclusion, bronchopneumonia, enterocolitis, malnutrition, and trauma were considered the most common causes of death in confined white-tailed deer in this study.
Assuntos
Doenças dos Animais/mortalidade , Causas de Morte , Cervos , Animais , Pennsylvania/epidemiologia , Estudos RetrospectivosRESUMO
An indirect immunofluorescence (IFA) test with a 96-well, flat-bottomed microplate was developed to detect avian pneumovirus (APV) antigen in Vero cell cultures. Samples of nasal turbinates and swabs from infraorbital sinuses and trachea were collected from 4-week-old poults experimentally inoculated with APV. The APV titers by tissue culture IFA staining were compared with that of visual reading of cytopathic effect (CPE). The ability of IFA staining to detect APV antigen correlated well with visualizing CPE. The use of IFA staining of Vero cell cultures allowed detection of APV in substantially less time than the use of visualizing CPE. In addition, the use of IFA allowed specific identification of the virus in cell culture.
Assuntos
Técnica Indireta de Fluorescência para Anticorpo/veterinária , Infecções por Pneumovirus/veterinária , Pneumovirus/imunologia , Doenças das Aves Domésticas/diagnóstico , Animais , Antígenos Virais/análise , Técnicas de Cultura de Células , Chlorocebus aethiops , Pneumovirus/isolamento & purificação , Pneumovirus/patogenicidade , Infecções por Pneumovirus/diagnóstico , Infecções por Pneumovirus/imunologia , Doenças das Aves Domésticas/imunologia , Perus , Células VeroRESUMO
Four- and nine-week-old poults were inoculated with cell culture propagated avian pneumovirus (APV) into each conjunctival space and nostril, followed by inoculation 3 days later with Escherichia coli, Bordetella avium (BA), or Ornithobacterium rhinotracheale or a mixture of all three (EBO). Clinical signs were evaluated on days 3, 5, 7, 9, 11, and 14 postinoculation (PI) of APV. The poults were euthanatized on days 2, 4, 6, 10, and 14 PI, and blood and tissues were collected. The poults that received APV followed by EBO or BA alone developed more severe clinical signs related to nasal discharge and swelling of intraorbital sinuses than did poults inoculated with APV alone or bacteria alone. More severe pathologic changes were found in poults inoculated with APV+BA that extended to the air sacs and lungs, particularly in 9-wk-old poults. Bordetella avium was recovered from tracheas and lungs of birds that were inoculated with APV followed by EBO or BA alone. APV was detected by immunohistochemical staining in the upper respiratory tract longer in the groups of poults inoculated with APV and pathogenic bacteria than in those that received only APV, particularly when BA was involved. Viral antigen was also detected in the lungs of poults that were inoculated with APV followed by administration of EBO or BA alone. Loss of cilia on the epithelial surface of the upper respiratory tract was associated with BA infection and may enhance infection with APV, allowing deeper penetration of the virus into the respiratory tract.
Assuntos
Infecções Bacterianas/veterinária , Metapneumovirus , Infecções por Paramyxoviridae/etiologia , Doenças das Aves Domésticas/etiologia , Perus , Animais , Infecções Bacterianas/complicações , Infecções Bacterianas/patologia , Infecções por Bordetella/complicações , Infecções por Bordetella/patologia , Infecções por Bordetella/veterinária , Bordetella avium , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/veterinária , Infecções por Flavobacteriaceae/complicações , Infecções por Flavobacteriaceae/patologia , Infecções por Flavobacteriaceae/veterinária , Ornithobacterium , Infecções por Paramyxoviridae/patologia , Doenças das Aves Domésticas/patologia , Infecções Respiratórias/etiologia , Infecções Respiratórias/patologia , Infecções Respiratórias/veterináriaRESUMO
An avian influenza (AI) outbreak occurred in meat-type chickens in central Pennsylvania from December 2001 to January 2002. Two broiler breeder flocks were initially infected almost simultaneously in early December. Avian influenza virus (AIV), H7N2 subtype, was isolated from the two premises in our laboratory. The H7N2 isolates were characterized as a low pathogenic strain at the National Veterinary Services Laboratories based on molecular sequencing of the virus hemagglutinin cleavage site and virus challenge studies in specific-pathogen-free leghorn chickens. However, clinical observations and pathologic findings indicated that this H7N2 virus appeared to be significantly pathogenic in meat-type chickens under field conditions. Follow-up investigation indicated that this H7N2 virus spread rapidly within each flock. Within 7 days of the recognized start of the outbreak, over 90% seroconversion was observed in the birds by the hemagglutination inhibition test. A diagnosis of AI was made within 24 hr of bird submission during this outbreak using a combination of virus detection by a same-day dot-enzyme-linked immunosorbent assay and virus isolation in embryonating chicken eggs. Follow-up investigation revealed that heavy virus shedding (90%-100% of birds shedding AIV) occurred between 4 and 7 days after disease onset, and a few birds (15%) continued to shed virus at 13 days post-disease onset, as detected by virus isolation on tracheal and cloacal swabs. AIV was not detected in or on eggs laid by the breeders during the testing phase of the outbreak. The two flocks were depopulated at 14 days after disease onset, and AIV was not detected on the two premises 23 days after depopulation.
Assuntos
Surtos de Doenças/veterinária , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Vírus da Influenza A/classificação , Vírus da Influenza A/imunologia , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/diagnóstico , Influenza Aviária/virologia , Pennsylvania/epidemiologia , Aves Domésticas , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/virologia , Quarentena/veterináriaRESUMO
Pigeon protozoal encephalitis (PPE) is an emerging central nervous system disease of pigeons (Columba livia f. domestica) caused by the apicomplexan parasite Sarcocystis calchasi. The intermediate host specificity of S. calchasi had been considered high, as domestic chickens were resistant to experimental infection. Here, we have re-evaluated this concept and expanded the known host range of S. calchasi by experimental infection of cockatiels (Nymphicus hollandicus), a species distantly related to pigeons. In this work, a group of eight cockatiels were experimentally infected with S. calchasi, which resulted in a biphasic central nervous system disease that paralleled PPE in many aspects, albeit with a more diverse pathology. All cockatiels became lethargic and polyuric between days 7 and 13 pi and during that time schizonts of S. calchasi were found primarily in the liver and spleen accompanied by necrosis and inflammation. As with pigeons, neurological signs occurred during a chronic phase of the disease in three cockatiels between 57 and 63 dpi. However, all five cockatiels necropsied in that period, or at the end of the trial at 76 dpi, had a severe lymphohistiocytic and necrotizing encephalitis. No tissue cysts were found in the heart, and cockatiels infected with 10(5) sporocysts only had a negligible parasite load in skeletal muscles despite the presence of severe central nervous system lesions. Notably, intralesional schizonts were identified in the brain of one cockatiel. In contrast to previous results, intralesional schizonts were also identified in the brains of three of six naturally infected pigeons from Minnesota and Missouri examined as part of an epidemiological investigation. In both the cockatiel and the pigeons, tissue cysts were found concurrently with schizonts suggesting an uncommon phenomenon in the Sarcocystis life cycle. Based on the results of this study, transmission of S. calchasi to avian species other than the domestic pigeon is possible. These findings suggest a, so far, unmonitored prevalence of S. calchasi in avian populations and highlight a possible ongoing dissemination of this parasite in the Northern Hemisphere.
Assuntos
Doenças das Aves/parasitologia , Cacatuas/parasitologia , Columbidae/parasitologia , Especificidade de Hospedeiro , Doenças do Sistema Nervoso/veterinária , Sarcocystis/fisiologia , Sarcocistose/veterinária , Animais , Doenças das Aves/patologia , DNA Espaçador Ribossômico/genética , Doenças do Sistema Nervoso/parasitologia , Doenças do Sistema Nervoso/patologia , Sarcocistose/parasitologia , Sarcocistose/patologiaRESUMO
Interactions between RNA binding proteins (RBPs) and genes are not well understood, especially in regulation of angiogenesis. The RBP HuR binds to the AU-rich (ARE) regions of labile mRNAs, facilitating their translation into protein and has been hypothesized to be a tumor-maintenance gene. Elevated levels of cytoplasmic HuR directly correlate with increased invasiveness and poor prognosis for many cancers, including those of the breast. HuR controls the expression of multiple genes involved in angiogenesis including VEGFα, HIF1α and thrombospondin 1 (TSP1). We investigated the role of HuR in estrogen receptor negative (ER(-)) breast cancer. MDA-MB-231 cells with higher levels of HuR have alterations in cell cycle kinetics and faster growth. Unexpectedly, HuR overexpression significantly interfered with tumor growth in orthotopic mouse models. The putative mechanism seems to be an anti-angiogenetic effect by increasing expression of TSP1 but also surprisingly, downregulating VEGF, a target which HuR normally increases. Our findings reveal that HuR may be regulating a cluster of genes involved in blood vessel formation which controls tumor angiogenesis. An approach of modulating HuR levels may overcome limitations associated with monotherapies targeting tumor vessel formation.
Assuntos
Antígenos de Superfície/metabolismo , Neoplasias da Mama/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Antígenos de Superfície/genética , Antígenos de Superfície/fisiologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proteínas ELAV , Proteína Semelhante a ELAV 1 , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Nus , Neovascularização Patológica/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/fisiologia , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Trombospondina 1/metabolismo , Transplante Heterólogo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The objective of this study was to evaluate different preparations of avian metapneumovirus (aMPV) subtype C as vaccine challenge in turkeys. Two aMPV isolates and their respective nasal turbinate homogenates after propagation in turkeys were used in the study. Significantly higher clinical sign scores were recorded in birds inoculated with 20 or 2% turbinate homogenate of recent isolate. Birds in the above groups showed more pronounced histopathological lesions, and a higher percentage of birds showed viral RNA and antigen in tissues. The data demonstrated that nasal turbinate homogenate of recent isolate produced severe clinical signs and lesions in turkeys and could be an ideal candidate for vaccine-challenge studies.
Assuntos
Metapneumovirus , Infecções por Paramyxoviridae/veterinária , Doenças das Aves Domésticas/virologia , Perus , Animais , Antígenos Virais/análise , Feminino , Histocitoquímica , Pulmão/patologia , Pulmão/virologia , Metapneumovirus/imunologia , Metapneumovirus/isolamento & purificação , Nariz/patologia , Nariz/virologia , Infecções por Paramyxoviridae/imunologia , Infecções por Paramyxoviridae/virologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/patologia , RNA Viral/análise , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Traqueia/patologia , Traqueia/virologiaRESUMO
This study was conducted to reexamine the hypothesis that human metapneumovirus (hMPV) will not infect turkeys. Six groups of 2-week-old turkeys (20 per group) were inoculated oculonasally with 1 of the following: noninfected cell suspension; hMPV genotype A1, A2, B1, or B2; or avian metapneumovirus (aMPV) subtype C. Poults inoculated with hMPV showed nasal discharge days 4-9 postexposure. Specific viral RNA and antigen were detected by reverse-transcription PCR and immunohistochemical evaluation, respectively, in nasal turbinates of birds exposed to hMPV. Nasal turbinates of hMPV-infected turkeys showed inflammatory changes and mucus accumulation. Each of the 4 hMPV genotypes caused a transient infection in turkeys as evidenced by clinical signs, detection of hMPV in turbinates, and histopathologic examination. Detailed investigation of cross-species pathogenicity of hMPV and aMPV and its importance for human and animal health is needed.