Epidemiology and diagnosis of Mycobacterium tuberculosis in captive Asian elephants (Elephas maximus).

The deaths of two Asian elephants (Elephas maximus) in August 1996 led the United States Department of Agriculture to require the testing and treatment of elephants for tuberculosis. From August 1996 to September 1999. Mycobacterium tuberculosis infection was confirmed by culture in 12 of 118 elephants in six herds. Eight diagnoses were made antemortem on the basis of isolation of M. tuberculosis by culture of trunk wash samples; the remainder (including the initial two) were diagnosed postmortem. We present the case histories, epidemiologic characteristics, diagnostic test results, and therapeutic plans from these six herds. The intradermal tuberculin test, enzyme-linked immunosorbent assay serology, the blood tuberculosis test, and nucleic acid amplification and culture are compared as methods to diagnose M. tuberculosis infection in elephants.     

Specific antibody responses and generation of antigenic variants in chickens immunized against a virulent avian influenza virus.

To examine the specificity of the antibody response to the influenza hemagglutinin and the generation of antigenic variants, chickens were immunized against the highly virulent H5 virus A/Ty/Ont/7732/66 (H5N9) and then challenged with a lethal dose of the virus. The antibody responses of these chickens to the hemagglutinin (HA) were examined with an enzyme-linked immunosorbent assay (ELISA) in which their sera were titrated for the ability to block the binding of monoclonal antibodies (MAbs) to five distinct neutralizing epitopes on the viral HA. Based on the ELISA results, a majority (5/6) of the chickens produced antibodies to three of the five neutralizing epitopes on the viral HA. After challenge, two of six immunized chickens shed virus and died; antigenic comparisons of isolates from these two chickens indicated the presence of an antigenic variant; i.e., there was a change in one neutralizing epitope on the HA of virus shed by one chicken. None of the chickens had produced antibodies to this particular epitope on the viral HA. Inoculation of chickens with this variant resulted in 100% mortality, demonstrating that a change in this particular epitope did not alter the virulence of the virus. These studies indicate that chickens immunized against highly virulent influenza viruses may excrete virulent variants following challenge with live virus.     

Neomycin toxicosis in calves

Calves (n = 4) were given neomycin (2.25 or 4.5 mg/kg) twice daily IM and were compared with 2 calves given penicillin IM. The 2 hallmarks of aminoglycoside toxicosis, nephrotoxicosis and ototoxicosis, were seen with both dosages of parenterally administered neomycin. Nephrotoxicosis was confirmed by abnormal findings in urinalysis (granular casts, proteinuria, low specific gravity), renal biopsy results (tubular degeneration and necrosis), and increased 24-hour amounts of urinary enzymes (alanine aminopeptidase and gamma-glutamyltranspeptidase). Azotemia, decreased creatinine clearance, polyuria, and polydipsia also were documented in calves given neomycin. Clinically, deafness was suspected in 2 calves and was documented by electrical auditory-evoked response tests. Abnormalities in partial thromboplastin times and renal residues of neomycin were seen in all 4 calves that were given neomycin, but not in calves that were given penicillin.     

Determination of tumor necrosis factor-alpha responsiveness in piglets around weaning using an ex vivo whole blood stimulation assay

Ex vivo whole blood stimulation with endotoxin has proved to be a useful method for quantitative evaluations of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) response ability in humans. In the present study, a dose- and time-response study was carried out in order to develop an ex vivo whole blood stimulation assay for the quantification of TNF-alpha production in pigs. The TNF-alpha response was enhanced with increasing endotoxin stimulation dose. The maximum TNF-alpha response occurred after 2-8 h of stimulation. Subsequently, the assay was used to evaluate the TNF-alpha response in pigs (n=32) in relation to weaning. The TNF-alpha response was 332 pg ml(-1) (+/-59 pg) plasma 2 days before weaning and 127 pg ml(-1) (+/-23 pg) plasma 2 days after weaning, which was a significant reduction (p<0.001). Total and differential counts of leucocytes were the same before and after weaning. Thus the lower TNF-alpha response may be due to reduced monocyte responsiveness to the endotoxin, rather than caused by a reduction in monocyte numbers. The reduced TNF-alpha response in piglets after weaning may be a factor of importance to the increased disease susceptibility seen in piglets in this period.     

Effects of DNA dose,route of vaccination,and coadministration of porcine interleukin-6 DNA on results of DNA vaccination against influenza virus infection in pigs

OBJECTIVE: To examine the effects of DNA dose, site of vaccination, and coadministration of a cytokine DNA adjuvant on efficacy of H1-subtype swine influenza virus hemagglutinin (HA) DNA vaccination of pigs. ANIMALS: 24 eight-week-old mixed-breed pigs. PROCEDURE: 2 doses of DNA were administered 27 days apart by use of a particle-mediated delivery system (gene gun). Different doses of HA DNA and different sites of DNA administration (skin, tongue) were studied, as was coadministration of porcine interleukin-6 (pIL-6) DNA as an adjuvant. Concentrations of virus-specific serum and nasal mucosal antibodies were measured throughout the experiment, and protective immunity was assessed after intranasal challenge with homologous H1N1 swine influenza virus. RESULTS: Increasing the dose of HA DNA, but not coadministration of pIL6 DNA, significantly enhanced virus-specific serum antibody responses. Pigs that received DNA on the ventral surface of the tongue stopped shedding virus 1 day sooner than pigs vaccinated in the skin of the ventral portion of the abdomen, but none of the vaccinated pigs developed detectable virus-specific antibodies in nasal secretions prior to challenge, nor were they protected from challenge exposure. Vaccinated pigs developed high virus-specific antibody concentrations after exposure to the challenge virus. CONCLUSIONS AND CLINICAL RELEVANCE: Co-administration of pIL-6 DNA did not significantly enhance immune responses to HA DNA vaccination or protection from challenge exposure. However, HA DNA vaccination of pigs, with or without coadministration of pIL-6 DNA, induced strong priming of the humoral immune system.     

Reinventing rural development in Vietnam: Discursive constructions of grassroots democracy during the renovation reform

Over the past decades Vietnam has seen striking efforts to reinvent the exercise of democratic rural development. Promotion of grassroots democracy, notably under the Grassroots Democracy Decree (GDD), has been an acute response by Communist Party and government to large scale unrest among the rural populace owing to dissatisfactions with a felt mismatch between espoused commitments to ‘good governance’ and its actual practice. Through evidence from field work, this paper assesses the implications of the GDD in the central and northern highlands, analyzing how the promotion of grassroots democracy is discursively constructed by rural development professionals. The results outline three dominant discourses, which center on their respective interests in liberalist democratization, improved efficiency in state renovation, and enhanced accountability in governing local policy ambiguities. It argues that ‘grassroots democracy’ is serving as a conceptual mediator, supporting learning between diverging interests associated with rural development and different ideological positions shrouding the notion of democracy itself. Yet, given the extent that discourses are reflective of how professionals relate to grassroots aspirations, grassroots movements, which originally ushered the Party and central government to pass the GDD, have a significant struggle ahead of them to affect concrete changes in professionals' practices.     

The qualitative assessment of glycosaminoglycans in the canine intervertebral disc using a critical electrolyte concentration staining technique.

Through the use of a critical electrolyte concentration staining technique, the glycosaminoglycans (GAGs) in the nucleus pulposus region of the canine intervertebral disc were arbitrarily identified as "hyaluronic acid", chondroitin sulphate and keratan sulphate. Approximate estimates of GAG concentration could be qualitatively deduced by determining the appropriate GAG "ALCIANOPHILIC INDEX". This index was considered to be an effective qualitative adjunct to chemical quantitation of GAGs in the intervertebral disc.     

Use of naloxone to reverse carfentanil citrate-induced hypoxemia and cardiopulmonary depression in Rocky Mountain wapiti (Cervus elaphus nelsoni).

With the use of a crossover study design, we investigated the respiratory and cardiovascular effects of naloxone administration in eight healthy Rocky Mountain wapiti (Cervus elaphus nelsoni) anesthetized with carfentanil (10 microg/kg i.m.) and xylazine (0.1 mg/kg). Anesthetized animals showed profound hypoxemia with mild hypercapnia, tachycardia, hypertension, and acidosis prior to naloxone administration. After monitoring equipment was placed, animals were administered either naloxone (2 microg/microg carfentanil i.v.) or an equivalent volume of normal saline. Mean values for PaO2, PaCO2, heart rate, and respiratory rate were significantly different between naloxone- and saline-treated groups, but mean blood pressure, hematocrit, and serum electrolyte concentrations were not. Mean PaO2 was 23.0 +/- 4.1 mm Hg prior to administration of naloxone or saline and increased to 50.2 +/- 7.3 mm Hg after naloxone administration. Mean PaO2 of saline-treated animals did not change significantly. Electrocardiograms of three saline-treated animals suggested myocardial hypoxia. Hypoxemia appeared to be caused by respiratory depression, hemodynamic alterations, and lateral recumbency. All but one animal remained anesthetized after naloxone administration. Anesthesia in all animals was reversed in < or = 4 min with naltrexone (100 mg/mg carfentanil i.v. s.c.) and yohimbine (0.1 mg/kg i.v.). One bolus of naloxone improved oxygenation in carfentanil-xylazine-anesthetized wapiti.