Laboratory animal medicine education and training in the uniformed services: a brief history.

The history of laboratory animal medicine education and training for uniformed (U.S. Army, U.S. Air Force, and U.S. Public Health Service) veterinarians is reviewed from the beginnings in 1961 at the U.S. Air Force School of Aerospace Medicine. Of the 636 currently listed diplomates of the American College of Laboratory Animal Medicine, at least 208 (32.7%) received specialty training or experience in this discipline while on extended active duty in one of the uniformed services. The evolving "climate" has led to the establishment of the most recent program within the uniformed services at the Uniformed Services University of the Health Sciences in Bethesda, Maryland.

Molecular and biochemical mechanisms of Pasteurella haemolytica leukotoxin-induced cell death.

Pasteurella haemolytica leukotoxin (LKT) is a member of the RTX family of pore-forming toxins that kill bovine immune cells. Several studies have suggested that RTX toxins kill target cells by the induction of apoptosis. In the present study, BL3 bovine leukaemia cells were exposed to LKT and assessed by molecular and flow cytometric techniques that measure different aspects of apoptotic cell death. The intoxicated cells demonstrated morphological, light scatter and Hoechst 33258 staining characteristics consistent with cells undergoing apoptosis. The cells also exhibited internucleosomal DNA fragmentation and poly (ADP-ribose) polymerase (PARP) cleavage, both indicators of apoptosis. LKT-treated cells bound annexin-V-FITC indicating that phosphatidylserine groups were translocated from the inner to the outer leaflet of the cell membrane. The effect of LKT on cells was dose dependent and inhibitable by incubation with anti-LKT monoclonal antibody. Finally, an early step for induction of apoptosis appears to be the binding of LKT to a beta2 integrin since pre-incubating cells with anti-beta2 integrin antibodies inhibited LKT-induced apoptosis. This study provides new insights into understanding the pathogenesis of bovine pasteurellosis and could lead to the development of both preventative and therapeutic strategies for disease management.

Protease activity in a hapten-induced model of ulcerative colitis in rats.

Inflammatory bowel disease (IBD) is a painful and debilitating condition affecting the mucosal lining of the colon and other areas of the gastrointestinal tract. IBD generally falls into two major categories: ulcerative colitis (UC) and Crohn's disease. We have utilized dinitrobenzenesulfonic acid (DNBS) to induce experimental UC in rats. Histopathologic analysis indicates that DNBS induces a condition in animals similar to human UC. Biochemical results revealed 6- to 10-fold elevated levels of serine protease activity in colon tissue from animals with UC as compared with matched controls. We also observed elevated levels of protease activity in tissue samples obtained from human patients with UC. Hence, our results demonstrate that protease activity is increased in rodent and human UC. These proteases may play a significant role in destruction of colonic tissue in IBD. Protease inhibitors that target serine proteases may be useful pharmacological agents to limit tissue destruction in IBD.

High mobility group proteins 1 and 2 recognize chromium-damaged DNA.

Chromium (Cr) is a human carcinogen and a potent DNA damaging agent. Incubation of DNA with CrCl3 resulted in dose-dependent binding of Cr to DNA and, at concentrations >20 microM, altered the electrophoretic mobility of a 100 bp oligonucleotide. We also demonstrate that high mobility group (HMG) proteins 1 and 2 bind Cr-damaged DNA (Cr-DNA). Protein binding was lesion density-dependent, with maximal binding to DNA treated with 100 microM CrCl3. HMG2 binds to Cr-DNA with a calculated Kd of approximately 10(-9) M. These proteins also bound DNA obtained from chromate-treated cells. These results suggest that the covalent attachment of Cr to DNA induces alterations in DNA structure which are recognized by HMG1 and HMG2. Therefore, these proteins may function as Cr-damaged DNA recognition proteins in vivo and as a consequence of binding, may play a role in directing the cellular response to Cr-DNA adduct formation.

DNA binding activity of the mammalian translation elongation complex: recognition of chromium- and transplatin-damaged DNA.

The elongation factor complex, EF-1H, serves an essential function in protein biosynthesis in eukaryotic cells, although the role of EF-1H in other physiological processes is unknown. In this report, we demonstrate that three components of EF-1H (EF-1 beta, EF-1 delta, EF-1 gamma) bind to DNA modified with chromium (Cr), a potent DNA-damaging agent and an established human carcinogen. The EF-1H complex also binds to transplatin modified DNA but not to cisplatin-modified DNA. These results demonstrate that the EF-1H complex has functional DNA binding activity and is capable of recognizing the distortions in DNA structure resulting from the covalent binding of Cr and transplatin to DNA.

Fluconazole therapy in a rhesus monkey (Macaca mulatta) with epidural Trichosporon beigelii in a cephalic recording cylinder.

An adult female rhesus monkey with a cephalic recording cylinder surgically implanted over a craniotomy site developed cloudy cylinder fluid and a white gelatinous plaque on the epidural capsule surface. Results of baseline hematologic, serum biochemical, and cerebrospinal fluid analysis and simian retrovirus panel were unremarkable. Aerobic culture of the cylinder fluid yielded a pure culture of Trichosporon beigelii. This organism is a ubiquitous saprophytic fungus that is a potential pathogen, especially in the immunocompromised host. Factors that could have contributed to the infection included a microenvironment in the cylinder that was favorable to fungal growth, and presence of a dural pseudocapsule of collagen and granulation tissue in the implant which could have inhibited cellular defense mechanisms. An intravenous formulation of fluconazole was selected for direct application into the recording cylinder on the basis of safety and efficacy. Fluconazole is a highly water-soluble, metabolically stable bis-triazole antifungal with excellent cerebrospinal fluid penetration and low toxicity. A 4-week course of treatment eliminated Trichosporon organisms from the cylinder. Change to oral administration of fluconazole was made at that time to allow use of cephalic cylinder antibiotics that are incompatible with fluconazole. Further treatment with fluconazole was continued orally for 3 more months to prevent fungal recrudescence. Culture of cylinder fluid was performed periodically for 6 months after resolution, and results remained negative for T. beigelii. This case is believed to be the first reported T. beigelii infection in a non-human primate. Fluconazole was effective in eliminating the infection from the cylinder and preventing its recurrence.

Helicobacter pylori isolated from the domestic cat: public health implications.

Helicobacter pylori has been directly linked with active chronic gastritis, peptic ulceration, and gastric adenocarcinoma in humans. Although a substantial portion of the human population is colonized with H. pylori, the patterns of transmission of the organism remain in doubt, and reservoir hosts have not been identified. This study documents the isolation of H. pylori from domestic cats obtained from a commercial vendor. The isolation of H. pylori from these cats was confirmed by morphologic and biochemical evaluations, fatty acid analysis, and 16S rRNA sequence analysis. H. pylori was cultured from 6 cats and organisms compatible in appearance with H. pylori were observed in 15 additional cats by histologic examination. In most animals, H. pylori was present in close proximity to mucosal epithelial cells or in mucus layers of the glandular or surface epithelium. Microscopically, H. pylori-infected cat stomachs contained a mild to severe diffuse lymphoplasmacytic infiltrate with small numbers of neutrophils and eosinophils in the subglandular and gastric mucosae. Lymphoid follicles were also noted, particularly in the antrum, and often displaced glandular mucosal tissue. Thus, the domestic cat may be a potential model for H. pylori disease in humans. Also, the isolation of H. pylori from domestic cats raises the possibility that the organism may be a zoonotic pathogen, with transmission occurring from cats to humans.

Kinetic study of serum gentamicin concentrations in baboons after single-dose administration.

This study establishes preliminary pharmacokinetic data on the use of gentamicin sulfate administered IM to baboons. Serum concentrations greater than or equal to 12 micrograms/ml are generally agreed to cause toxicosis in human beings. On the basis of preliminary test results suggesting that the manufacturer's recommended dosage for dogs of 4.4 mg/kg of body weight caused potentially toxic serum concentrations, a dosage of 3 mg/kg was chosen to conduct a single-dose kinetic study in 6 baboons. Using a single-compartment model, the gentamicin serum half-life for IM administration of 3 mg of gentamicin/kg was 1.58 hours, and serum concentrations remained below the potentially toxic concentrations reported for human beings. We suggest that a dosage of 3 mg/kg is safer than a dosage of 4.4 mg/kg administered IM to baboons. Minimal inhibitory concentrations for 2 Pseudomonas aeruginosa isolates were less than or equal to 1 micrograms/ml. On the basis of our measured elimination half-life of 1.58 hours, it is reasonable to suppose that dosing q24 h will be inadequate to maintain therapeutic serum concentrations. We calculate that serum concentrations will remain at or above our measured minimal inhibitory concentration for P aeruginosa (1 micrograms/ml) for 100% of the treatment time if the animal is dosed q 6h, 78% for dosing q 8h, and 52% for dosing q 12h. Therefore, we suggest 3 mg/kg, q 8h or q 6h as appropriate dosing schedules for the use of gentamicin sulfate administered IM to baboons.

Current and future policies regarding laboratory animal welfare.

Laboratory animal welfare has made tremendous strides in recent years. The first laboratory animal welfare law was not enacted until 1966, and laboratory animal medicine as a specialty did not even exist until the 1960s. The AAALAC accreditation program has stimulated improvements in accredited institutions, and the FDA and EPA Good Laboratory Practices Acts had a major impact on industry in the 1970s, but the most visible impact upon academic institutions was made by NIH enforcing their Policy in the 1980s by suspending funding to several programs and institutions. The Association of American Medical Colleges and the Association of American Universities jointly published Recommendations for Governance and Management of Institutional Animal Resources in October 1985, following very closely the provisions of NIH and the Guide. Animal rights groups have even contributed toward the improvement of animal welfare policies by their recent flurry of demonstrations, thefts, and vandalism. The end result has been an impressively rapid upgrading and standardization of animal care and use policies and programs at all types of institutions that use animals in their work. Most major institutions now have qualified and credentialed laboratory animal medicine specialists directing their programs, conscientious and responsive animal care and use committees overseeing and evaluating animal welfare, and qualified, well-trained animal care staff and investigators. Institutions that do not meet these standards undergo great pressure from the USDA, NIH, their peers, and the public to bring their programs into compliance quickly and appropriately.(ABSTRACT TRUNCATED AT 250 WORDS)

Report of a panel discussion on how to run an effective Animal Care and Use Committee.

There was a consensus between the Panel and the participants in the audience as follows: All animal use should be reviewed by an Animal Care Committee. The policies and procedures of that Committee must, in the letter and in the spirit of federal guidelines, be developed by each institution, or group of institutions, mindful of its own operational practices and should apply to all research using animals, irrespective of the source of funds. The ACC will be accountable to the public at large for the conduct of animal research. To obtain the support of the community, the ACC must have the active support of the institution, both administratively and financially, and its own academic community who must be involved in ACC activities and, where possible, in the development of its policies and procedures. Education is essential. The Committee must understand its obligations and duties especially as they relate to confidentiality and internal freedom of discussion (this applies particularly to lay members). The faculty, staff, and students must understand the protective role of the Committee for both the community and animal subjects. The institutional community must be prepared to accept the responsibilities of animal use and so accept the need for education and updating in appropriate techniques and experimental design. Individual institutions and organizations, such as the Scientists Center for Animal Welfare, can and will provide information and guidance to those seeking assistance.

Effects of exercise on bleomycin-induced pulmonary toxicity in mice.

NIH/Swiss mice were used to study the effects of exercise on bleomycin-induced pulmonary toxicity. After a 2-week exercise acclimation program the mice were treated with bleomycin sc twice a week and swim-exercised for 1 hour three times a week for 6 weeks. Based on higher mortality and significant weight loss in the exercise-drug-treated mice and a comparison of histological data, it is concluded that exercise exacerbates the toxicity of bleomycin.

The Schirmer tear test in rhesus monkeys (Macaca mulatta).

A clinical case of keratoconjunctivitis sicca prompted a study to determine normal values for the Schirmer tear test in rhesus monkeys. Normal values for rhesus monkeys were calculated to be 6 to 24 mm wetting/minute (mean = 15.1) and it was determined that neither sex nor ketamine had a statistically significant effect on these values.

A surgical procedure and tethering system for chronic blood sampling, infusion, and temperature monitoring in caged nonhuman primates.

A jacket and tethering system was used to maintain chronic catheters in monkeys, which provided catheter access and manipulability without further restraint. Surgical placement of catheters and a temperature probe allowed for a common cutaneous exit and interface with the jacket and tether. Monkeys were fitted in a sterile leather or denim jacket which was attached to a sterilized flexible stainless steel cable. Through this conduit, an indwelling temperature probe, as well as catheters from the internal jugular and femoral veins, were attached to a swivel unit located on the upper portion of the cage. The internal jugular catheter was used for the continuous infusion of support solution. The catheter from the femoral vein was maintained with a heparin lock and used for serial blood sampling. Using this system, it was possible to obtain frequent blood samples and body temperature readings, and to administer a continuous intravenous infusion without chemical or excessive physical restraint. To date, 367 monkeys, 322 cynomolgus (Macaca fasicularis), 16 rhesus (Macaca mulatta), and 21 African green (Cercopithecus aethiops) have been studied using this procedure.

Acute clinical malaria (Plasmodium inui) in a cynomolgus monkey (Macaca fascicularis).

Acute clinical malaria caused by Plasmodium inui was diagnosed in an adult female cynomolgus monkey (Macaca fascicularis) 4 years after importation into the United States. Stress and immunosuppression associated with experimentation completed 2 weeks earlier may have contributed to the development of severe clinical disease. Clinical findings included severe regenerative anemia, hepatosplenomegaly, weakness, lethargy, weight loss, and anorexia. The infection was treated and successfully eliminated with chloroquine hydrochloride administered intramuscularly at a dose of 5 mg/kg base given at 0, 6, 24, 48, and 72 hours. Treatment also included a blood transfusion and intensive supportive care.

Hematologic characterization of naturally occurring malaria (Plasmodium inui) in cynomolgus monkeys (Macaca fascicularis).

Twenty of 47 recently imported cynomolgus monkeys (Macaca fascicularis) were found to have malarial infections. The agent identified was Plasmodium inui. All infections were subclinical in nature. Parasitemias ranged from 10 to 900 parasites/mm3 of whole blood. Pre- and post-treatment hematologic values were evaluated following treatment with chloroquine. Treatment was effective in clearing parasitemias from 13 of 14 infected monkeys. Pretreatment values of hematocrit, hemoglobin, and mean corpuscular volume were significantly different in infected animals compared to noninfected animals. While post-treatment hemoglobin and hematocrit values returned to noninfected control levels, mean corpuscular volume values of infected animals remained significantly lower in the post-treatment period.