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1.
Avian Dis ; 60(1): 56-62, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26953944

ABSTRACT

T-2 toxin, a very potent immunotoxic Type A trichothecene, is a secondary metabolite produced primarily by Fusarium spp., which grows on cereal grains and can lead to contaminated livestock feed. Repeated exposure to T-2 toxin has been shown to cause immunosuppression and decrease the resistance of exposed animals to a variety of infectious diseases; however, the effects of T-2 toxin on Marek's disease (MD) vaccinal immunity have not been reported. Four trials were conducted to determine the effects of T-2 toxin on vaccinal immunity against MD. Day-old, white leghorn chicks of Avian Disease and Oncology Laboratory line 15I5 × 71 were treated daily for 7 days via crop gavage with T-2 toxin at a sublethal dose of 1.25 mg/kg body weight. Treated and untreated chicks were also vaccinated with turkey herpesvirus (HVT) at hatch and were challenged with the JM strain of MD virus (MDV) at 8 days of age. Chickens were tested for HVT viremia at 1 wk postvaccination immediately before challenge, and for HVT and MDV viremia at 3 wk postchallenge. Chickens were observed for the development of MD lesions and mortality within 8 wk of age. T-2 toxin significantly reduced body weight and titers of HVT viremia within 7 days after hatch. T-2 toxin shortened the incubation period for the development of MD lesions and mortality, but only in unvaccinated chickens. The percent MD protection in T-2-toxin-treated, HVT-vaccinated chickens ranged from 82% to 96% and was comparable to that in HVT-vaccinated untreated control chickens (89%-100%). The data suggest that exposure of chickens to sublethal doses of T-2 toxin for 7 consecutive days after hatch may influence the development of 1) HVT viremia; and 2) MD lesions and mortality, but only in unvaccinated chickens.


Subject(s)
Chickens , Herpesvirus 1, Meleagrid/immunology , Herpesvirus 2, Gallid/immunology , Marek Disease/immunology , Poultry Diseases/immunology , Viral Vaccines/immunology , Animals , Female , Male , Marek Disease/virology , Poultry Diseases/virology , T-2 Toxin , Vaccination/veterinary
2.
Br J Radiol ; 87(1039): 20140029, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24814694

ABSTRACT

OBJECTIVE: To measure the effect of the insertion of less-difficult malignant cases on subsequent breast cancer detection by breast imaging radiologists. METHODS: The research comprises two studies. Study 1: 8 radiologists read 2 sets of images each consisting of 40 mammographic cases. Set A contained four abnormal cases, and Set B contained six abnormal cases, including two priming cases (less difficult malignancies) placed at intervals of three and five subsequent cases before a subtle cancer. Study 2: 16 radiologists read a third condition of the same cases, known as Set C, containing six abnormal cases and two priming cases immediately preceding the subtle cancer cases. The readers were asked to localize malignancies and give confidence ratings on decisions. RESULTS: Although not significant, a decrease in performance was observed in Set B compared with in Set A. There was a significant increase in the receiver operating characteristic (ROC) area under the curve (z = -2.532; p = 0.0114) and location sensitivity (z = -2.128; p = 0.0333) between the first and second halves of Set A and a marginal improvement in jackknife free-response ROC figure of merit (z = -1.89; p = 0.0587) between the first and second halves of Set B. In Study 2, Set C yielded no significant differences between the two halves of the study. CONCLUSION: Overall findings show no evidence that priming with lower difficulty malignant cases affects the detection of higher difficulty cancers; however, performance may decrease with priming. ADVANCES IN KNOWLEDGE: This research suggests that inserting additional malignant cases in screening mammography sets as an audit tool may potentially lead to a decrease in performance of experienced breast radiologists.


Subject(s)
Breast Neoplasms/diagnostic imaging , Clinical Competence , Mammography/standards , Repetition Priming , Diagnostic Errors/prevention & control , Female , Humans , Mental Recall , Perception , ROC Curve , Sensitivity and Specificity , Task Performance and Analysis
3.
Clin Radiol ; 69(4): 397-402, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24418670

ABSTRACT

AIM: To examine how the location where reading takes place and the availability of prior images can affect performance in breast test-set reading. MATERIALS AND METHODS: Under optimized viewing conditions, 10 expert screen readers each interpreted a reader-specific set of images containing 200 mammographic cases. Readers, randomly divided into two groups read images under one of two pairs of conditions: clinical read with prior images and laboratory read with prior images; laboratory read with prior images and laboratory read without prior images. Region-of-interest (ROI) figure-of-merit (FOM) was analysed using JAFROC software. Breast side-specific sensitivity and specificity were tested using Wilcoxon matched-pairs signed rank tests. Agreement between pairs of readings was measured using Kendall's coefficient of concordance. RESULTS: Group performances between test-set readings demonstrated similar ROI FOMs, sensitivity and specificity median values, and acceptable levels of agreement between pairs of readings were shown (W = 0.75-0.79, p < 0.001) for both pairs of reading conditions. On an individual reader level, two readers demonstrated significant decreases (p < 0.05) in ROI FOMs when prior images were unavailable. Reading location had an inconsistent impact on individual performance. CONCLUSION: Reading location and availability of prior images did not significantly alter group performance.


Subject(s)
Breast Neoplasms/diagnostic imaging , Clinical Competence , Mammography , Quality Assurance, Health Care , Radiographic Image Enhancement , Clinical Competence/standards , Decision Making , Female , Humans , Observer Variation , Quality Assurance, Health Care/standards , Reproducibility of Results , Sensitivity and Specificity
4.
Avian Dis ; 56(3): 578-82, 2012 Sep.
Article in English | MEDLINE | ID: mdl-23050477

ABSTRACT

Chickens infected with subgroup J avian leukosis virus (ALV J) early in posthatch life develop viremia followed by a neutralizing antibody (Nab) response that may or may not be able to clear the viremia. Occasionally, chickens that do clear viremia by developing an efficient Nab response revert to viremia, and the factors responsible for this reversion are not clear. In this study, it was hypothesized that stress can cause seroconverted viremia-free chickens to revert to viremia. Adult (52-wk-old) male commercial meat-type chickens that were exposed to ALV J at hatch and had since cleared viremia and remained viremia-free for up to 40 wk, when subjected to chronic stress (for 14 days) induced by porcine adrenocorticotrophin (ACTH), reverted to viremia and cloacal shedding (2/6 [33%]). However, chickens that were contact-exposed to ALV J at 32 wk of age and had seroconverted failed to revert to viremia when subjected to similar chronic stress. Stress did not increase the susceptibility of adult meat-type chickens to ALV J infection by contact exposure. The lack of statistical significance due to the small sample size is a limitation of this study. However, in general, the results suggest that treatment of chickens with ACTH can cause reversion of viremia and cloacal shedding in ALV J-seroconverted adult male chickens that had been exposed to the virus at hatch, but not in chickens that were contact-exposed at 32 wk of age. The results warrant further studies with greater sample size to examine the role of stress in ALV J epidemiology.


Subject(s)
Adrenocorticotropic Hormone/toxicity , Avian Leukosis Virus/classification , Avian Leukosis/virology , Chickens , Poultry Diseases/virology , Viremia , Adrenocorticotropic Hormone/administration & dosage , Animals , Antibodies, Viral , Avian Leukosis/immunology , Avian Leukosis Virus/genetics , Male , Stress, Physiological/drug effects , Stress, Physiological/immunology
5.
Clin Radiol ; 67(7): 623-8, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22486992

ABSTRACT

The purpose of this article is to review the limitations associated with current methods of assessing reader accuracy in mammography screening programmes. Clinical audit is commonly used as a quality-assurance tool to monitor the performance of screen readers; however, a number of the metrics employed, such as recall rate as a surrogate for specificity, do not always accurately measure the intended clinical feature. Alternatively, standardized screening test sets, which benefit from ease of application, immediacy of results, and quicker assessment of quality improvement plans, suffer from experimental confounders, thus questioning the relevance of these laboratory-type screening test sets to clinical performance. Four key factors that impact on the external validity of screening test sets were identified: the nature and extent of scrutiny of one's action, the artificiality of the environment, the over-simplification of responses, and prevalence of abnormality. The impact of these factors on radiological and other contexts is discussed, and although it is important to acknowledge the benefit of standardized screening test sets, issues relating to the relevance of test sets to clinical activities remain. The degree of correlation between performance based on real-life clinical audit and performances at screen read test sets must be better understood and specific causal agents for any lack of correlation identified.


Subject(s)
Breast Neoplasms/diagnostic imaging , Clinical Competence , Mammography/statistics & numerical data , Mammography/standards , Female , Humans , Observer Variation
6.
Avian Dis ; 54(2): 848-56, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20608529

ABSTRACT

We have previously demonstrated a high incidence of chickens with persistent viremia even in the presence of neutralizing antibodies (V+A+) against the inoculated parental virus in commercial meat-type chickens inoculated at hatch with subgroup J avian leukosis virus (ALV J) field isolates. In this study, we used an ALV J molecular clone, ADOL pR5-4, to determine the role of neutralizing antibody (NAb) escape mutants in maintaining a high incidence of viral persistence, namely, V+A+ infection profile in commercial meat-type chickens. Chickens were housed as a flock in a pen or housed in isolation in solitary Horsfall-Bauer units for testing for NAb escape variants. The emergence of NAb escape variants was evaluated by sequential autologous virus neutralization (VN) (between virus and antibody from the same sampling period) and heterologous VN (between virus and antibody from preceding and succeeding sampling periods). Sequential virus isolates and corresponding antisera from 18 chickens were examined by VN matrix. In all chickens, autologous virus isolates were not neutralized by corresponding antisera. However, some of these resilient autologous virus isolates were neutralized by antibodies from subsequent sampling intervals. Nucleotide sequence analysis of consecutive isolates from three individually housed chickens with V+A+ infection profile revealed distinct changes within the envelope region, suggesting viral evolution to escape the host immune response. These results demonstrate that the emergence of antibody escape variants in commercial meat-type chickens contributes to ALV J persistence.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Avian Leukosis Virus/immunology , Avian Leukosis/virology , Chickens , Amino Acid Sequence , Animals , Antibody Specificity , Avian Leukosis/blood , Avian Leukosis/immunology , Avian Leukosis Virus/classification , Gene Expression Regulation, Viral , Gene Products, env/chemistry , Gene Products, env/genetics , Gene Products, env/metabolism , Genetic Variation , Molecular Sequence Data , Phylogeny , Poultry Diseases/immunology , Poultry Diseases/virology
7.
Vet Pathol ; 46(2): 282-7, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19261641

ABSTRACT

The role of subgroup J avian leukosis virus (ALV J) infection profile in the development of histiocytic sarcomatosis (HS) in chickens was evaluated using retrospective analysis of 2 experiments involving in ovo and at-hatch inoculation of commercial meat-type and ADOL line 0 chickens with 100 or 10,000 TCID(50) of various strains ALV J. HS was observed only in persistently viremic, meat-type chickens that were inoculated at hatch, but not in immunotolerized (persistently viremic, with no antibodies), in ovo inoculated chickens. However, the immunotolerized, in ovo inoculated chickens developed a high incidence of myeloid tumors. HS appeared to arise from the splenic ellipsoids and red pulp, and metastasized to liver, kidney, and other organs. The neoplastic cells were diffusely positive for ChL5, CD45, and MHC class II with multifocal infiltration of T and B lymphocytes. Expression of viral antigen gp85 within HS was very low compared with that noted in ALV J-induced myelocytomas. The above observations suggest that the mechanisms of oncogenesis of HS might be different from that of other ALV J-induced tumors.


Subject(s)
Avian Leukosis Virus/classification , Chickens , Histiocytic Sarcoma/veterinary , Poultry Diseases/pathology , Viremia , Animals , Histiocytic Sarcoma/immunology , Histiocytic Sarcoma/pathology , Histiocytic Sarcoma/virology , Liver/pathology , Meat , Poultry Diseases/virology , Spleen/pathology
8.
Avian Pathol ; 37(1): 7-13, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18202944

ABSTRACT

Immunohistochemistry and polymerase chain reaction (PCR) were used to test for the presence of avian leukosis virus (ALV) J viral antigen gp85 and proviral DNA, respectively, in various tissues (adrenal gland, bone marrow, gonad, heart, kidney, liver, lung, pancreas, proventriculus, sciatic nerve, spleen, and thymus). Tissues were collected from 32-week-old commercial meat-type and Avian Disease and Oncology Laboratory experimental White Leghorn Line 0 chickens with the following different infection profiles: tV + A-, included in ovo-tolerized viraemic chickens with no neutralizing antibodies (NAbs) on any sampling; ntV + A-, included chickens that were viraemic and NAb-negative at the time of termination at 32 weeks post hatch, but had NAbs on up to two occasions; V+ A+, included chickens that were viraemic and NAb-positive at the time of termination at 32 weeks post hatch, and had NAbs on more than two occasions; V - A+, included chickens that were negative for viraemia and NAb-positive at the time of termination at 32 weeks post hatch, and had antibody on more than two occasions; V - A-, included chickens that were never exposed to ALV J virus. There was a direct correlation between viraemia and tissue distribution of gp85, regardless of the NAb status and strain of chickens, as expression of ALV J gp85 was noted in only viraemic chickens (tV + A-, ntV + A-, V+ A+), but not in non-viraemic seroconverted chickens (V - A+). Of the four oligonucleotide primers pairs used in PCR to identify ALV J provirus, only one primer set termed H5/H7 was useful in demonstrating ALV J proviral DNA in the majority of the tissues tested from non-viraemic, antibody-positive chickens (V - A+). The results suggest that PCR using primer pair H5/H7 is more sensitive than immunohistochemistry in identifying ALV J in chickens that have been exposed to virus, but are not actively viraemic.


Subject(s)
Antigens, Viral/isolation & purification , Avian Leukosis Virus/classification , Avian Leukosis/virology , Chickens/genetics , Proviruses/isolation & purification , Animals , Antigens, Viral/metabolism , Avian Leukosis/metabolism , DNA, Viral/isolation & purification , Meat , Retrospective Studies
9.
Avian Dis ; 50(1): 131-4, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16617997

ABSTRACT

Although avian species are known to be susceptible to infection with Mycobacterium spp. organisms, much remains unknown about the susceptibility of birds to infection with M. bovis. The objective of this current study was to determine if wild turkeys (Meleagris gallopavo) can be infected with M. bovis when inoculated by the oral or intratracheal route. Six turkeys were orally inoculated and another six were inoculated via the trachea with a high dose of M. bovis, 1 x 10(5) CFU/ml. Six turkeys were sham-inoculated controls. Two turkeys from each treatment group were sacrificed on days 30, 60, and 90 postinoculation. There were no gross or microscopic lesions consistent with mycobacteriosis in the 23 inoculated turkeys over the 90-day duration of this study. Fecal cultures were also consistently negative for M. bovis when sampled before inoculation and on days 1, 30, and 60 postinoculation. Two intratracheally inoculated turkeys were positive for M. bovis in visceral tissues at 30 days postinoculation. However, this finding was only indicative of passive persistence of mycobacteria in the tissues and not of infection, as there were no attendant lesions or clinical compromise to support infection. Thus, it can be concluded that young wild turkeys are resistant to infection with M. bovis and, therefore, pose minimal threat as reservoir or spillover hosts for this organism.


Subject(s)
Bird Diseases/microbiology , Mycobacterium bovis/physiology , Tuberculosis/veterinary , Animals , Animals, Wild/microbiology , Bird Diseases/pathology , Body Weight , Disease Reservoirs/veterinary , Disease Susceptibility , Feces/microbiology , Female , Male , Mycobacterium bovis/pathogenicity , Pilot Projects , Tuberculosis/microbiology , Tuberculosis/pathology , Turkeys
10.
Avian Dis ; 47(2): 470-5, 2003.
Article in English | MEDLINE | ID: mdl-12887208

ABSTRACT

The purpose of this pilot study was to determine if pigeons (Columba livia) are susceptible to infection with Mycobacterium bovis by either oral or intratracheal inoculation and to assess their possible role in the lateral transmission of bovine tuberculosis. Six pigeons were orally inoculated with 1.3 x 10(5) colony-forming units of M. bovis, six pigeons were intratracheally inoculated with the same dose, and six pigeons served as noninoculated controls. The study continued for 90 days postinoculation (PI), with groups of birds necropsied at 30-day intervals, and fecal samples and tissues were collected for mycobacterial culture. Two pigeons, one intratracheally inoculated and one orally inoculated, shed M. bovis in their feces at 1 day PI, and one intratracheally inoculated bird shed M. bovis in its feces 60 days PI. Whereas no illness or weight loss was present during the course of the study, 2 of 12 inoculated birds exhibited microscopic lesions of mycobacteriosis, and the organism was isolated from tissues of three inoculated birds. Pigeons are susceptible to infection with M. bovis after high dose inoculation and can shed the organism in their feces for up to 60 days PI; intratracheally inoculated birds appear more likely to become active fecal shedders of M. bovis. Although these were high dose inoculations under experimental conditions, pigeons may potentially play a role in the lateral transmission of bovine tuberculosis between infected and uninfected mammalian hosts.


Subject(s)
Bird Diseases/microbiology , Columbidae/microbiology , Mycobacterium Infections/veterinary , Mycobacterium bovis/physiology , Animals , Bird Diseases/pathology , Bird Diseases/transmission , Disease Reservoirs , Disease Susceptibility , Feces/microbiology , Lung/microbiology , Lung/pathology , Mycobacterium Infections/transmission
11.
J Vet Med Sci ; 65(2): 255-8, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12655123

ABSTRACT

A mixed-antigen agar gel enzyme assay (AGEA) was developed to detect antibodies to poxviruses in chicken and turkey sera. The assay combines the principles of immunodiffusion and enzyme assay. For the detection of antibodies to fowl poxvirus (FP), pigeon poxvirus (PP) and turkey poxvirus (TP) in turkey serum samples, the three antigens were combined to form a mixed-antigen assay. To screen for antibodies to FP and PP in chicken serum samples, the two antigens were combined. When FP and PP viruses were combined as antigens, the sensitivity for chicken sera was 64% but the sensitivity of the agar gel precipitation test (AGPT) was 34% (P<0.001). When antibodies were detected in turkey sera using the mixed antigens, the AGEA had a sensitivity of 66.4% while that of AGPT was 25% (P<0.001).


Subject(s)
Antibodies, Viral/analysis , Avipoxvirus/immunology , Avipoxvirus/isolation & purification , Chickens/virology , Immunoassay/methods , Immunoassay/veterinary , Turkeys/virology , Animals , Antigens, Viral , Chickens/immunology , Immune Sera/immunology , Poxviridae Infections/diagnosis , Poxviridae Infections/immunology , Poxviridae Infections/veterinary , Poxviridae Infections/virology , Sensitivity and Specificity , Turkeys/immunology
12.
Poult Sci ; 81(1): 34-40, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11885897

ABSTRACT

Ducklings were given egg-derived antibody against Salmonella enteritidis (Ab) in drinking water daily to determine if infection could be prevented. Pekin ducklings in all experimental groups were infected on Day 1 or 5 with 0.7 x 10(6) Salmonella enteritidis (SE). Spleen, liver, and intestine of each bird were collected and cultured on Days 7, 14, 21, and 28. Only livers and spleens were culture positive for SE. Ducklings infected on Day 1 had more SE infections than controls at each observation. Ducklings infected on Day 5 had fewer SE infections than controls on Days 7, 14, and 21. The same experiment was repeated to determine if SE infection could be prevented under production conditions. Only 10 ducks per group were infected with 1.02 x 10(7) SE. In addition to Ab, one group each, infected on Day 1 or 5, received a proprietary probiotic (Pro) daily to determine if Pro was synergistic to Ab. Groups receiving Ab and Pro and infected on Day 1 had fewer birds infected than Ab alone in Day 1-infected birds. Both Day 1-infected groups had more birds infected than controls. Birds infected on Day 5 had fewer ducks infected than controls on Days 7, 14, and 21. Except for Day 14, birds receiving both Ab and Pro and infected on Day 5 had fewer birds infected than Ab alone on Day 21 and 28. Probiotics act synergistically with oral Ab. Oral antibodies may serve as a tool to prevent salmonella infection in poultry.


Subject(s)
Antibodies, Bacterial/therapeutic use , Ducks , Poultry Diseases/prevention & control , Probiotics/therapeutic use , Salmonella Infections, Animal/prevention & control , Salmonella enteritidis/immunology , Animals , Antibodies, Bacterial/administration & dosage , Antibodies, Bacterial/immunology , Drug Synergism , Female , Liver/microbiology , Poultry Diseases/microbiology , Probiotics/administration & dosage , Spleen/microbiology
13.
Avian Dis ; 45(3): 709-18, 2001.
Article in English | MEDLINE | ID: mdl-11569749

ABSTRACT

The purpose of this series of pilot studies was to determine whether the passerine species studied are susceptible to infection with Mycobacterium bovis. Separate experiments were conducted on wild-caught starlings (Sturnus vulgaris) and American crows (Corvus brachyrhynchos). In each experiment, four birds were challenged intraperitoneally and four were challenged orally with microorganisms. Challenge dose was 1 x 10(5) colony-forming units of M. bovis cultured from a white-tailed deer (Odocoileus virginianus) case in Michigan. Birds were euthanatized at 1 and 2 mo postinoculation. Histologic lesions suggestive of mycobacteriosis, without the presence of acid-fast bacilli, were noted in all experimental groups. Mycobacterial cultures performed on pooled tissue samples were positive for M. bovis in only some of the intraperitoneal inoculates of each species.


Subject(s)
Bird Diseases/microbiology , Mycobacterium bovis/pathogenicity , Songbirds/microbiology , Tuberculosis/veterinary , Administration, Oral , Animals , Animals, Wild , Bird Diseases/pathology , Body Weight , Deer , Injections, Intraperitoneal/veterinary , Liver/pathology , Organ Size , Pilot Projects , Tuberculosis/microbiology , Tuberculosis/pathology
14.
Arch Virol ; 146(5): 983-92, 2001.
Article in English | MEDLINE | ID: mdl-11448035

ABSTRACT

Glycoproteins H and L form a hetero-oligomeric complex (gH-L) which plays an important role in virus entry to host cells and cell-to-cell infection in herpesviruses. Interaction of gH and gL is considered to be critical for the biological function of these two glycoproteins. To investigate the interaction of MDV gH and gL, both gH and gL were expressed in in vitro cell culture systems using indirect immunofluorescence assay with gH and gL antibodies. The results suggested that co-expression of gH and gL in the same cells are required and necessary for both gH and gL subcellular translocation and cell surface expression. gL expressed in recombinant fowlpox virus (rFPV) infected chicken embryo fibroblasts (CEF) was consistently secreted into the culture medium. The primary peptide of gL binds with that of gH in the cytosol or ER lumen. By binding with gH, gL could anchor itself on the cell surface allowing for surface expression and viral spread to uninfected cells. The binding domain of gH was mapped to the amino acids 451-659 (SacI-HindIII) fragment and was essential for gH-L complex formation.


Subject(s)
Herpesvirus 2, Gallid/physiology , Viral Envelope Proteins/physiology , Animals , Antibodies, Viral/immunology , Binding Sites , Biopolymers , Cells, Cultured/virology , Chick Embryo , Culture Media, Conditioned , Fibroblasts/virology , Fluorescent Antibody Technique, Indirect , Genetic Vectors/genetics , Herpesvirus 2, Gallid/genetics , Herpesvirus 2, Gallid/immunology , Macromolecular Substances , Nucleopolyhedroviruses/genetics , Protein Binding , Protein Conformation , Protein Structure, Tertiary , Protein Transport , Recombinant Fusion Proteins/physiology , Spodoptera , Viral Envelope Proteins/chemistry , Viral Envelope Proteins/genetics , Viral Envelope Proteins/immunology , Virus Cultivation
15.
Virus Genes ; 22(3): 353-61, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11450954

ABSTRACT

The structure of the icosahedral adenovirus capsid is highly conserved among Adenoviridae. In its native form, the hexon is the major capsid protein. The nascent hexon requires the 100 kDa folding protein to fold into its native, trimeric form. The hexon and 100 kDa folding protein were co-expressed in a fowlpox virus (FPV) vector and in the recombinant FPVs (rFPVs) in which the hexon and 100 kDa folding protein genes are cloned head to tail, the native hexon could be detected with indirect immunofluorescence and immunoprecipitation using a native hexon monoclonal antibody. The FPV-@X100 construct, in which the 100kDa folding protein gene follows the hexon gene in a head to tail fashion, elicited the best humoral response in chickens. An attenuated HEV commercial vaccine elicited higher and longer lasting anti-HEV titers than FPV-@X100. Humoral immunity was also compared in turkeys inoculated with rFPVs expressing the hexon alone, the 100 kDa folding protein alone, or expressing both genes in different configurations. No anti-HEV humoral immune response was detected in turkeys inoculated with the rFPVs expressing the hexon alone or the 100 kDa folding protein alone.


Subject(s)
Adenoviridae/genetics , Capsid Proteins , Capsid/genetics , Fowlpox virus/classification , Animals , Antibodies, Viral/biosynthesis , Base Sequence , Blotting, Southern , Blotting, Western , Cell Line , DNA Primers , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique, Indirect , Fowlpox virus/genetics , Fowlpox virus/immunology , Microscopy, Confocal , Precipitin Tests , Recombination, Genetic
16.
J Am Vet Med Assoc ; 218(7): 1111-5, 2001 Apr 01.
Article in English | MEDLINE | ID: mdl-11318361

ABSTRACT

OBJECTIVE: To determine proportions of cats in which feline infectious peritonitis (FIP) was diagnosed on an annual, monthly, and regional basis and identify unique characteristics of cats with FIP. DESIGN: Case-control study. SAMPLE POPULATION: Records of all feline accessions to veterinary medical teaching hospitals (VMTH) recorded in the Veterinary Medical Data Base between January 1986 and December 1995 and of all feline accessions for necropsy or histologic examination at 4 veterinary diagnostic laboratories. PROCEDURE: Proportions of total and new feline accessions for which a diagnosis of FIP was recorded were calculated. To identify characteristics of cats with FIP, cats with FIP were compared with the next cat examined at the same institution (control cats). RESULTS: Approximately 1 of every 200 new feline and 1 of every 300 total feline accessions at VMTH in North America and approximately 1 of every 100 accessions at the diagnostic laboratories represented cats with FIP. Cats with FIP were significantly more likely to be young, purebred, and sexually intact males and significantly less likely to be spayed females and discharged alive than were control cats. The proportion of new accessions for which a diagnosis of FIP was recorded did not vary significantly among years, months, or regions of the country. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that FIP continues to be a clinically important disease in North America and that sexually intact male cats may be at increased risk, and spayed females at reduced risk, for FIP. The high prevalence of FIP and lack of effective treatment emphasizes the importance of preventive programs, especially in catteries.


Subject(s)
Feline Infectious Peritonitis/epidemiology , Age Factors , Animals , Case-Control Studies , Cats , Coronavirus/isolation & purification , Feline Infectious Peritonitis/diagnosis , Female , Hospitals, Animal , Hospitals, Teaching , Male , North America/epidemiology , Orchiectomy/veterinary , Ovariectomy/veterinary , Risk Factors , Sex Characteristics
17.
Avian Pathol ; 30(1): 49-53, 2001 Feb.
Article in English | MEDLINE | ID: mdl-19184873

ABSTRACT

Two cases where multiple juvenile cockatiels exhibited inappetance, depression, upper respiratory signs, and "lockjaw" are described. Symptoms progressed over several weeks until all birds died, in spite of antibacterial therapy. Seven affected birds from each case were submitted for diagnostic evaluation. Microscopically, all birds had necrotizing rhinitis and sinusitis, as well as myositis, perineuritis and osteomyelitis affecting the jaw muscles and cranial bones. Multiple bacterial agents were isolated from the lungs and sinuses in both cases. Juvenile cockatiels appear to be particularly susceptible to temporomandibulitis, temporomandibular joint rigidity, or "lockjaw". Once chronic inflammation and fibrosis develop, it appears unlikely that jaw mobility can be restored.

18.
Avian Dis ; 44(4): 1012-6, 2000.
Article in English | MEDLINE | ID: mdl-11195627

ABSTRACT

The diagnosis of eastern equine encephalitis (EEE) virus infection in avian species is relatively difficult when compared with other species. There are no characteristic histologic lesions in the avian brain that would serve to distinguish EEE from infections with, for example, Newcastle disease or highly pathogenic avian influenza virus. Traditionally, virus isolation (VI) and/or hemagglutination inhibition (HI) has been used for a definitive diagnosis of EEE in birds. Recently, we developed an immunohistochemistry (IHC) technique for confirmatory diagnosis of EEE infection in equine brain. This test also detected EEE virus in formalin-fixed avian brain. VI confirmed IHC finding in two cases of EEE in ring-neck pheasants. IHC is a rapid, sensitive test for confirming and differentiating a histopathologic diagnosis of EEE in avian species and should be considered as an alternative test to VI or HI.


Subject(s)
Bird Diseases/diagnosis , Encephalomyelitis, Eastern Equine/veterinary , Animals , Bird Diseases/pathology , Encephalomyelitis, Eastern Equine/diagnosis , Encephalomyelitis, Eastern Equine/pathology , Female , Immunoenzyme Techniques , Male , Michigan
19.
Avian Dis ; 43(4): 704-20, 1999.
Article in English | MEDLINE | ID: mdl-10611987

ABSTRACT

A novel syndrome was observed after inoculation of 3-wk-old chickens with highly virulent Marek's disease virus (MDV) strains. This syndrome was characterized by the acute onset of neurologic signs including flaccid paralysis of neck and limbs 9-10 days postinoculation, typically resulting in death 1-3 days after the onset of clinical signs. Most affected birds died, and spontaneous recovery was rare. Few if any gross tissue changes were found. Histologic brain lesions included acute vasculitis with vasogenic edema and perivascular cuffing. The syndrome was influenced by the virus strain and dose and by chicken strain and B haplotype and was prevented by vaccination with turkey herpesvirus. Chickens up to 18 wk of age were susceptible. On the basis of clinical signs and histopathology, the syndrome was determined to be an acute form of transient paralysis (TP); its more acute nature and virtual lack of spontaneous recovery differentiated this syndrome from classical TP. Affected birds were viremic, and brains were positive for viral DNA by polymerase chain reaction assays, but these tests were also positive in inoculated chickens without clinical signs and may have limited value for diagnosis. Although acute TP should occur only rarely in Marek's disease-vaccinated commercial flocks, this syndrome may be important in laboratory studies, where it could interfere with pathogenesis trials. Finally, acute TP appears to be one component in the pathogenesis of the early mortality syndrome, a previously described immunodepressive disease induced by inoculation of 1-day-old chicks with highly virulent MDV.


Subject(s)
Brain/virology , Herpesvirus 2, Gallid/pathogenicity , Marek Disease/physiopathology , Paralysis/etiology , Animals , Brain/pathology , Cerebellum/pathology , Chickens , DNA, Viral/isolation & purification , Female , Herpesvirus 2, Gallid/genetics , Herpesvirus 2, Gallid/isolation & purification , Hyperplasia , Hypertrophy , Male , Marek Disease/pathology , Necrosis , Paralysis/pathology , Paralysis/virology , Polymerase Chain Reaction , Species Specificity , Syndrome , Virulence
20.
Avian Dis ; 43(4): 721-37, 1999.
Article in English | MEDLINE | ID: mdl-10611988

ABSTRACT

A chronological study of central nervous system disorders induced by Marek's disease virus (MDV) has been conducted. Neurologic clinical signs were recorded daily for individual chickens of two genetic lines after inoculation of 13 serotype 1 MDV strains representing all three pathotypes. In addition to classical transient paralysis (TP) previously described by many workers, and acute TP, described in the companion paper, we have identified for the first time two other neurologic syndromes, persistent neurologic disease (PND) and late paralysis (LP). PND designates birds that showed a variety of neurologic signs (ataxia, torticollis, and nervous tics) after recovery from paralysis (12-15 days postin-oculation [DPI]) that either persisted through the observation period or presented a cyclic pattern. LP was a rare syndrome characterized by the late onset of the paralytic stage (about 20 DPI), perhaps indicating occasional failure of the initial intraabdominal inoculation to induce infection. Clinical signs and histopathologic alterations of the brain were also evaluated sequentially in chickens of two genetic lines after inoculation with two MDV strains (virulent MDV and very virulent plus MDV). Although clinical response differed greatly among treatment groups, types of lesions (endotheliosis, mononuclear perivascular cuffing, vasculitis, vacuolization, and increase in cellularity of the neuropil) were similar. However, early onset of lesions (by 6 days) appeared to be associated with a greater severity of clinical signs. We also found that neurologic response was greatly influenced by viral pathotype (virulence). This study thus confirms that the central nervous system is an important target organ for MDV resulting in several distinct clinical manifestations and suggests that neurologic responses in antibody-free chickens might be a useful criterion for virus pathotyping.


Subject(s)
Brain/pathology , Herpesvirus 2, Gallid/classification , Marek Disease/physiopathology , Marek Disease/virology , Nervous System Diseases/physiopathology , Nervous System Diseases/virology , Paralysis/etiology , Animals , Chickens , Female , Herpesvirus 2, Gallid/isolation & purification , Herpesvirus 2, Gallid/pathogenicity , Male , Necrosis , Nervous System Diseases/pathology , Paralysis/pathology , Paralysis/virology , Serotyping , Species Specificity , Vacuoles/pathology
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