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B J Weigler

Publications and source records attributed to B J Weigler.

At least 19 recordsLinked to original sources
PubMed2001

Multivariable regression analysis and other findings from the 1999 joint ASLAP/ACLAM economic survey of laboratory animal veterinarians.

Results from a 1999 economic survey of laboratory animal veterinarians were used to develop a multivariable linear regression model capable of predicting income in light of a large set of characteristics of veterinarians and their employers. When considered simultaneously, the variables of experience, supervisory responsibility, ACLAM board certification, geographic region, type of employer, size of animal facility, and job title provided the best model fit, in agreement with an earlier statistical model of income for persons in this profession. Aspects of the demographics of faculty appointments and secondary sources of professional income available to some laboratory animal veterinarians also were evaluated.

Animals↗
PubMed2001

A primer in epidemiologic methodology.

Epidemiology is defined as the study of the distribution and determinants of disease within populations. In addition to the requirements for disease surveillance, epidemiologic methods have numerous applications in laboratory animal science and can reveal important insights into the multifactoral mechanisms of disease, thereby aiding in the design of optimized intervention strategies. Observational approaches to data collection can be used to quantify the role of causal factors under natural circumstances, complementing the value of experimental studies in this field. The meaning and appropriate use of standard measures of disease frequency and exposure-disease relationships are reviewed, along with explanations of bias and confounding. Recommendations for reporting the methods and findings from this type of work in comparative medicine literature are presented. Aspects of model-based approaches to data analysis are introduced, offering further opportunities for gaining needed information from epidemiologic study of problems in laboratory animal medicine and management.

Animal Diseases↗
PubMed1998

Detection of feline herpesvirus 1 DNA in corneas of cats with eosinophilic keratitis or corneal sequestration.

OBJECTIVE: To determine whether feline herpesvirus 1 (FHV-1) DNA is in the corneas of clinically normal cats and cats with eosinophilic keratitis or corneal sequestration. SAMPLE POPULATION: Corneal biopsy specimens obtained from cats referred for treatment of corneal sequestration or eosinophilic keratitis. PROCEDURE: Corneal scraping or keratectomy specimens collected from clinically normal cats, cats with eosinophilic keratitis, and cats with corneal sequestration were evaluated for FHV-1 DNA by use of polymerase chain reaction (PCR). DNA was extracted from the tissue, and 1 microgram was assayed for FHV-1 by use of a single-round (40 cycles) PCR assay with primers directed at a 322-bp region of the thymidine kinase gene. Polymerase chain reaction positivity for clinically normal and affected cats of various breeds was compared by chi 2 analysis at alpha = 0.05. RESULTS: The FHV-1 DNA was detected in 5.9% (1/17) of corneas from clinically normal cats, in 55.1% (86/156) of corneal sequestra, and in 76.3% (45/59) of scraping specimens from cats with eosinophilic keratitis. Prevalence was significantly (P < 0.001) greater for cats with corneal sequestration or eosinophilic keratitis than for clinically normal cats. For cats with corneal sequestration, prevalence of FHV-1 DNA was significantly lower in Persian and Himalayan, compared with domestic shorthair and longhair breeds. CONCLUSION: Data strongly imply involvement of FHV-1 in the pathogenesis of eosinophilic keratitis and corneal sequestration. In Persian and Himalayan breeds, however, other nonviral factors also appear to be involved. CLINICAL RELEVANCE: Feline herpesvirus 1 must be considered when treating cats with corneal sequestration or eosinophilic keratitis.

Animals↗
PubMed1997

High sensitivity polymerase chain reaction assay for active and latent feline herpesvirus-1 infections in domestic cats.

A polymerase chain reaction (PCR) assay was developed and used to detect feline herpesvirus-1 (FHV-1) in conjunctival and oropharyngeal swabs, and in latently infected tissues (trigeminal ganglia, optic nerves, optic chiasma, olfactory bulbs and corneas) collected from 10 experimentally infected cats. There was good agreement between parallel tests of the swab specimens by PCR and virus isolation assay during the phase of acute, latent and recurrent disease episodes (kappa = 0.63, P < 0.001). The PCR reliably detected < or = 240 copies of FHV-1 template DNA, significantly improving upon previously published PCR assays for the agent.

Animals↗
PubMed1997

Effect of a live attenuated intranasal vaccine on latency and shedding of feline herpesvirus 1 in domestic cats.

A prospective study was conducted that evaluated duration of virus shedding through acute and experimentally-induced recurrent disease episodes in 12 cats, and tissue distribution of latent infections, following intranasal vaccination with a temperature sensitive (ts) mutant strain of feline herpesvirus 1 (FHV1). Six of these cats were challenged with a virulent field strain of the agent to assess the extent to which vaccination affected subsequent shedding of virus and the establishment of latent infections. Virus isolation (VI) tests were done in parallel with a polymerase chain reaction (PCR) assay to compare the performance of each diagnostic method. The PCR confirmed that all 12 cats shed virus throughout the periods of vaccination, challenge or mock-challenge, and a cyclophosphamide-dexamethasone stress protocol to reactivate latent infections. Shedding to the tsFHV1 was documented by VI for up to 25 days following vaccination and for up to 15 days following challenge, but not after experimental stress. Overall, FHV1 was present in 144 of 300 (48%) cat-days of testing by PCR compared to 32 of 300 (11%) by VI. The frequency and distribution of latent FHV1 detected in neurologic, ophthalmic, and other tissues by PCR were identical for vaccine-only and vaccine-challenge groups, thereby disproving previous hypotheses that tsFHV1 mutants administered by this route protect against latency.

Administration, Intranasal↗
PubMed1997

Effects of valacyclovir in cats infected with feline herpesvirus 1.

OBJECTIVE: To determine whether orally administered valacyclovir can be used safely and effectively to treat cats with primary, feline herpesvirus 1 (FHV-1) infection. ANIMALS: 14 specific-pathogen-free adult cats. PROCEDURE: Cats were infected with FHV-1 strain 87-727 (300 microliters, 10(7) plaque-forming units/ml) by ocular and nasal inoculations, and were treated every 6 hours with dextrose (controls) or valacyclovir (60 mg/kg of body weight, PO). Virus shedding from both eyes and the oropharynx was monitored every 2 days by virus isolation, and subjective clinical scores were assigned daily for ocular and nasal discharge and conjunctival hyperemia. Urinalysis, CBC, and serum biochemical analysis were done prior to inoculation, and on days 2, 5, 7, 9, and 12 of infection. Differences in CBC and serum biochemical indices between groups were compared, as were differences between preinfection values and maximal postinfection values, rectal temperature, and scores for disease severity. RESULTS: All cats developed acute conjunctivitis and rhinitis typical of FHV-1 infection. Beginning between days 6 and 9, valacyclovir-treated cats became noticeably more lethargic and dehydrated than did cats of the control group. Total WBC and neutrophil counts were significantly lower in cats of the valacyclovir group. The experiment was terminated on day 12 for humane reasons. Histologic changes attributable to FHV-1 infection were similar in all cats. Additional histologic abnormalities seen only in the valacyclovir-treated cats were coagulative necrosis of the renal tubular epithelium, centrilobular atrophy and hepatic necrosis, and severe bone marrow depression. CONCLUSIONS: Cats appear to be uniquely sensitive to the toxic effects of valacyclovir, and even high doses appear not to suppress FHV-1 replication in acutely infected cats. CLINICAL RELEVANCE: Use of valacyclovir is of questionable value in cats with acute FHV-1 infection and, at high doses, the drug may be toxic.

Acyclovir↗
PubMed1996

Serological evidence for zoonotic hantaviruses in North Carolina rodents.

In a survey of seven species of wild rodents (n = 423) collected between October 1993 and March 1994 from the three principal ecological biomes of North Carolina (USA), we found hantavirus antibodies in seven (2%) of 301 Peromyscus spp. Hantavirus antibodies were detected in P. leucopus and P. maniculatus captured from mountain and coastal island biomes. Three mice were positive for Sin Nombre virus, while four others had antibodies to Seoul virus or a related agent. Two mice serologically positive for Sin Nombre virus were collected from inside a private mountain domicile. We conclude that the risk of human exposure to hantaviruses in North Carolina resembles that for most other areas of the continental United States.

Animals↗
PubMed1996

Efficacy of various therapeutic regimens in eliminating Pasteurella pneumotropica from the mouse.

Pasteurella pneumotropica, a gram-negative opportunistic pathogen, can be isolated from the oropharynx, intestinal tract, and reproductive tract of clinically normal mice and has been associated with various clinical syndromes, including conjunctivitis, infections of the reproductive tract, otitis, and subcutaneous abscess formation. Enrofloxacin, a fluoroquinolone bactericidal antimicrobial, has been shown to be effective in eliminating P. multocida from rabbits. We sought to determine whether enrofloxacin would eliminate P. pneumotropica from mice known to be asymptomatically infected with the agent. Pasteurella pneumotropica-positive (culture and immunofluorescence assay) male (n = 55) and female (n = 55) C57BL/6N mice were randomly assigned to one of seven treatment groups or to a control group. These groups were designed to evaluate the efficacy of enrofloxacin administered orally via the drinking water or parenterally at three dosages (8.5, 25.5, and 85.0 mg/kg of body weight per day) over a 14-day treatment period. A tetracycline-treated group (60 mg/kg per day) and an untreated control group were included for comparisons. Repeated oropharyngeal swab and fecal specimens were obtained for culture through posttreatment day 30, and specimens from numerous enteric and reproductive organs collected during necropsy were used to evaluate group differences. Enrofloxacin eliminated evidence of P. pneumotropica from all sites when administered at 25.5 or 85 mg/kg but not at 8.5 mg/kg by either route for at least 30 days after treatment. Tetracycline-treated and control groups remained consistently culture-positive throughout the study. We concluded that the oral route may be a more practical method for treating large numbers of mice. Enrofloxacin may be a practical and inexpensive alternative to cesarian rederivation or embryo transfer for the elimination of P. pneumotropica in mice.

Administration, Oral↗
PubMed1996

Randomly amplified polymorphic DNA polymerase chain reaction assay for molecular epidemiologic investigation of Pasteurella pneumotropica in laboratory rodent colonies.

After an episode of clinical Pasteurella pneumotropica infection was diagnosed in a C57BL/6N mouse, a randomly amplified polymorphic DNA polymerase chain reaction assay (RAPD-PCR) was developed and used to genetically characterize and differentiate 52 field isolates and laboratory reference strains of P. pneumotropica and related bacteria. A survey of rodents in the facility recovered 36 isolates of P. pneumotropica from 30 mice, six isolates from hamsters, and three isolates from rats during the follow-up investigation. Antibiograms and routine bacteriologic evaluations for morphologic and biochemical characteristics on selective media did not substantively aid in the differentiation of these isolates, but the RAPD-PCR revealed four strains of P. pneumotropica in the colony, two of which were confined to rats and hamsters. The RAPD-PCR unambiguously differentiated Heyl and Jawetz biotypes of P. pneumotropica recovered from mice, identified two additional genetic groups for rat and hamster isolates, and clearly distinguished P. pneumotropica from related bacteria. Most field isolates were genetically consistent with the Jawetz biotype of P. pneumotropica. The RAPD-PCR is a fast, sensitive, and efficient method for identifying genetic differences between strains of the P. pneumotropica complex and can contribute substantially in addressing the epidemiology, pathogenesis, and taxonomic classification of this common opportunistic pathogen.

Animals↗
PubMed1995

Zoonotic hantaviruses; new concerns for the United States.

Hantaviruses have emerged as agents of significant morbidity and mortality in human beings. These pathogens are maintained in nature as not clinically apparent, persistent infections in roden reservoirs, varying with each virus, and are shed via rodent feces, urine, and salivary excretions. Human exposure to hantaviruses principally occurs through the respiratory tract route and is focal and discontinuous, paralleling the distribution of virus in reservoir species and the likelihood of human-rodent interactions. Prior to 1993, hantaviruses were established etiologic agents of human febrile nephropathies and hematologic abnormalities on several continents, exclusive of North America. An episode of severe respiratory tract illness developed in association with a group of novel hantaviruses in the United States during 1993-1994, resulting in at least 98 confirmed cases of disease from 21 states and 51 deaths. Current evidence suggests that hantaviruses of zoonotic potential have long existed across widespread areas of the United States but have gone unrecognized.

Animals↗
PubMed1995

Risk of venereal B virus (cercopithecine herpesvirus 1) transmission in rhesus monkeys using molecular epidemiology.

The importance of venereal modes of B virus (cercopithecine herpesvirus 1) transmission was evaluated in 49 rhesus monkeys tested at necropsy. Antibodies to B virus were demonstrated in 19 monkeys, but no active viral shedding was detected in mucosal swabs collected at death. The polymerase chain reaction demonstrated presence of the ICP 18.5 (UL28) gene of B virus in neuronal tissues of 15 monkeys presumed to be latently infected, including 12.8% of trigeminal and 22.9% of lumbosacral ganglia pools. Two monkeys tested positive at both sites. Breeding history was predictive of B virus seropositivity (odds ratio, 1.64; 95% confidence interval, 1.21-2.23; P < .05). The population attributable risk of B virus seropositivity due to breeding was 22.7%, similar to the proportion of monkeys with B virus DNA in neuronal tissues subserving the genital region. Sexual contact is a significant, but not predominant, mode of B virus transmission between monkeys.

Age Factors↗
PubMed1994

Seroepidemiologic studies of cytomegalovirus infection in a breeding population of rhesus macaques.

A protein immunoblot (western blot) assay was developed for detection of IgG and IgM antibodies to cytomegalovirus (CMV) in banked serum and was used to study the epidemiology of infection in a breeding population of rhesus macaques. All juveniles and adults were antibody-positive to CMV. Repeated samples from 1990-born infants (n = 28) over a 12-month period allowed retrospective assessment of CMV seroconversion. Most infants (23 of 25 seroconversions) were apparently exposed to CMV during their first year of life. The IgM testing permitted identification of seroconversion time points in eight infants. Risk factors that significantly affected seroconversion probabilities in the study population were not found. Cytomegalovirus-free rhesus macaques are potentially valuable for viral teratology and pathogenesis research projects; however, present epidemiologic findings suggest that establishment of CMV-free colonies will be difficult in conventional settings.

Animals↗