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Biomedical subjects

C A Baldwin

Publications and source records attributed to C A Baldwin.

At least 19 recordsLinked to original sources

Feline immunodeficiency virus and puma lentivirus in Florida panthers (Puma concolor coryi): epidemiology and diagnostic issues.

This study documents the seroprevalence of feline immunodeficiency virus (FIV) and puma lentivirus (PLV) in free-ranging and captive Florida panthers (Puma concolor coryi) (n = 51) and translocated Texas cougars (P. concolor stanleyana) (n = 10) from 1985 to 1998. The sera were tested for anti-FIV antibodies by enzyme-linked immunosorbent assay (ELISA) and Western blot tests. The ELISAs were read kinetically (KELA) and the sera were retrospectively examined by PLV peptide ELISA. Eleven panthers and one cougar were positive by KELA; 4 panthers and 4 cougars were equivocal; 35 panthers and 5 cougars were negative; and 1 panther had no data. Seven of the 11 KELA-positive panthers were also positive by Western blot tests and all but one were positive by PLV peptide ELISA. Ten KELA-negative and Western blot-negative cats, were positive by PLV peptide ELISA. KELA results varied within cats from one sample period to the next, but PLV peptide ELISA results were consistent. Territorial sympatry and mating behaviour, noted from radiotelemetry location data on the cats, may have contributed to viral transmission between seropositive animals. These findings suggest that Florida panthers and the introduced Texas cougars have been exposed to FIV and/or PLV.

Animals↗

Equine herpesvirus 2-associated granulomatous dermatitis in a horse.

Granulomatous dermatitis in horses has been linked to many etiologies, including various parasites, fungi, and bacteria. Idiopathic forms of granulomatous inflammation-producing diseases, some of which are localized to the skin, also have been reported in horses. Herein we describe a case of recurrent equine granulomatous skin disease characterized by intranuclear viral inclusions within macrophages and giant cells. The histologic changes were primarily noted in the deep dermis and included multifocal to coalescing areas of necrosis marked by histiocytic cell infiltration and presence of giant cells. Electron microscopic examination revealed intranuclear and intracytoplasmic viral particles consistent with herpesvirus. Sequence results of the polymerase chain reaction product were consistent with equine herpesvirus 2, adding another possible etiology to the list of differentials in cases of equine granulomatous skin disease.

Animals↗

Epidemiology of feline infectious peritonitis among cats examined at veterinary medical teaching hospitals.

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.

Age Factors↗

Endometritis in postparturient cattle associated with bovine herpesvirus-4 infection: 15 cases.

Suppurative, ulcerative endometritis associated with bovine herpesvirus-4 (BHV-4) infection was identified in 15 postparturient dairy cows from 5 separate dairies. Characteristic eosinophilic to amphophilic intranuclear viral inclusion bodies were identified within degenerate endometrial lining epithelium and endothelial cells. Bovine herpesvirus-4 was confirmed as the etiology by a combination of fluorescent antibody assays, viral isolation, heminested PCR, ultrastructural examination of the uterus and inoculated tissue culture cells, and negative-stain electron microscopy of tissue culture supernatant. Viral particles measuring 70-95 nm were demonstrated in uterine epithelial and endothelial cells by electron microscopy. Bacteria including Arcanobacterium pyogenes, Escherichia coli, and an alpha-Streptococcus isolate were isolated from all uteri. Bovine herpesvirus-4-associated endometritis has been previously reported in sporadic cases in Europe but has not been previously reported in the United States. Endometritis associated with BHV-4 appears to be an emerging syndrome in Georgia dairy herds.

Animals↗

Effects of macrophage inhibitory factor-A3 (MIF-A3) on cytokine secretion and phagolysosome fusion in murine macrophages.

Macrophage inhibitory factor-A3 (MIF-A3) is a fraction derived from Mycobacterium avium serovar 2 (Mav2) that consists of a small amine containing compound (peptide), trehalose and two or three short chain fatty acids. MIF-A3 has been shown to inhibit candidacidal activity of murine thioglycolate-elicited peritoneal-derived macrophages and bovine peripheral blood monocytes, and scavenge reactive oxygen intermediates. In this study, MIF-A3 was evaluated for its effect on secretion of IL-1beta, IL-6, IL-10, TNFalpha and GM-CSF in C57BL/6 murine thioglycolate-elicited peritoneal-derived macrophages, with and without pre-incubation with affinity purified goat anti-MIF-A3 IgG, using ELISA cytokine kit analysis. Results of this study suggest that anti-MIF-A3 IgG does not enhance clearance of Mav2, alter phagocytosis or alter phagosome-lysosome interactions as determined by electron microscopy in Mav2 infected macrophages. MIF-A3 does induce secretion of IL-6, but does not induce secretion of TNFalpha, IL-1beta, and GM-CSF. TNFalpha has been previously shown to reduce growth, while IL-6 has been shown to enhance growth of M. avium. Since IL-6 appears to enhance growth of M. avium and MIF-A3 induces IL-6 secretion, MIF-A3 may be responsible for enhanced intracellular growth in M. avium infections and be a factor in the pathogenesis of M. avium infections.

Animals↗

Efficacy of vaccination for Mycobacterium avium with whole cell and subunit vaccines in experimentally infected swine.

Mycobacterium avium infections are a common problem in large swine producing states and cause substantial financial losses at slaughter inspection due to carcass condemnation. Once the infection is established in a swine herd it is difficult to effectively prevent or eliminate the disease. Previous mouse studies in our laboratory suggested that Macrophage Inhibitory Factor-A3 (MIF-A3) is a virulence factor of M. avium and potential antigen for vaccine development. In this study we evaluated the efficacy of a killed 'whole cell' M. avium serovar 2 bacterin and conjugated MIF-A3 subunit vaccine in preventing infection and disease in swine challenged with virulent M. avium serovar 2. Gross and microscopic pathology, acid-fast staining, culture and polymerase chain reaction (PCR) for the M. avium specific insertion sequence IS902 were utilized in evaluation. Results indicated that neither vaccine prevented infection in challenged animals; however, a 47% reduction in severity of disease was found in swine vaccinated with the 'whole cell' M. avium serovar 2 bacterin. Reduction in severity of disease was not detected in animals vaccinated with the subunit MIF-A3 vaccine.

Animals↗

Protection of pigs by vaccination of pregnant sows against eastern equine encephalomyelitis virus.

Serum-virus neutralizing antibodies were detected in serum and colostrum of sows vaccinated during pregnancy with commercially available vaccines against eastern equine encephalomyelitis virus (EEEV), and antibodies were detected in serum from nearly all pigs from vaccinated sows following colostrum uptake. Serum-virus neutralizing antibody (SVN) test titers were measured in colostrum and pigs at the next farrowing, and additional vaccination of sows prior to the third farrowing led to elevated SVN titers in serum, colostrum and all pigs. Six pigs from vaccinated sows challenged at 8 to 9 days of age with 1 x 10(6) TCID50 EEEV did not develop the high temperatures or signs of central nervous system disease that 6 pigs from non-vaccinated sows developed. Virus was isolate from blood and oropharyngeal swabs from all pigs from non-vaccinated sows with blood virus titers as high as 9.3 x 10(4) TCID50, while only low levels of virus were detected in blood and oropharyngeal swabs from pigs from vaccinated sows. Virus was also isolated from tonsils collected at necropsy from 3 pigs from non-vaccinated and 1 pig from vaccinated sows. Vaccination of pregnant sows leads to development of maternal antibodies that are transmitted via colostrum to pigs and are protective against clinical EEEV related disease after experimental challenge with EEEV. In addition, vaccination prevents amplification of virus in infected pigs and could result in protection of animals and farm labor in the environment of infected pigs.

Animals↗

Disseminated adenovirus infection associated with cutaneous and visceral hemorrhages in a nursing piglet.

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.

Adenoviridae Infections↗

Eastern equine encephalomyelitis virus infection in swine.

In 1 of 2 outbreaks of eastern equine encephalomyelitis virus (EEEV) infection in swine, 280 of 350 pigs died. Histopathologic findings in the brain were typical of EEEV infection. In addition, multifocal necrosis and inflammation were seen in the myocardium. Follow-up investigation in 1 of the herds revealed antibody response to EEEV in surviving pigs and in adult swine. Growth retardation was noticed in surviving pigs. Histologic examination revealed mild lesions in the brain of the survivors.

Animals↗

Noticing of unexpected events by adults with and without mental retardation.

Adults without mental retardation commonly fail to notice nominally obvious aspects of naturalistic scenes (Becklen & Cervone, 1983). We replicated and extended this effect to adults with mild mental retardation. Adults with and without retardation viewed a 60-second videotape of an amateur basketball game. They were instructed to press a button whenever the ball was passed. At one point, a woman carrying an open umbrella walked bodily through the ongoing action. Becklen and Cervone found that only 35% of adults without retardation noticed this unexpected event and that noticing was not predicted by task performance prior to the woman's appearance. In the present study noticing rates for subjects without retardation were similar to those reported by Becklen and Cervone and noticing by subjects with mental retardation was at least as high. Task performance for subjects with mental retardation was significantly lower than that of subjects without retardation, but noticing was not predicted by task performance (prior to the unexpected event) for either group. Results were interpreted in the context of an ecological approach to attention.

Adolescent↗

A serologic survey of Oklahoma cats for antibodies to feline immunodeficiency virus, coronavirus, and Toxoplasma gondii and for antigen to feline leukemia virus.

A serologic survey was done on 618 cat sera submitted to the Oklahoma Animal Disease Diagnostic Laboratory between July 1, 1987 and June 30, 1988. The samples were collected from clinically normal and sick cats. The sera were tested for the presence of antibodies to feline immunodeficiency virus by a commercial immunoassay, to a coronavirus by an indirect fluorescent antibody test, and to Toxoplasma gondii by a commercial latex agglutination test and for the presence of feline leukemia virus antigen with one of 3 different commercial assay kits. Ten percent of the sera had antibodies to feline immunodeficiency virus, 35% had antibodies to a coronavirus, and 22% had antibodies to Toxoplasma gondii. Feline leukemia virus antigen was detected in 15% of the sera. Thirty-two percent of the sera had evidence of exposure to 2 or more of the agents.

Animals↗