The Endothelin-A Receptor Antagonist Zibotentan Induces Damage to the Nasal Olfactory Epithelium Possibly Mediated in Part through Type 2 Innate Lymphoid Cells.

Zibotentan, an endothelin-A receptor antagonist, has been used in the treatment of various cardiovascular disorders and neoplasia. Castrated athymic nude mice receiving zibotentan for a preclinical xenograft efficacy study experienced weight loss, gastrointestinal bloat, and the presence of an audible respiratory click. Human side effects have been reported in the nasal cavity, so we hypothesized that the nasal cavity is a target for toxicity in mice receiving zibotentan. Lesions in the nasal cavity predominantly targeted olfactory epithelium in treated mice and were more pronounced in castrated animals. Minimal lesions were present in vehicle control animals, which suggested possible gavage-related reflux injury. The incidence, distribution, and morphology of lesions suggested direct exposure to the nasal mucosa and a possible systemic effect targeting the olfactory epithelium, driven by a type 2 immune response, with group 2 innate lymphoid cell involvement. Severe nasal lesions may have resulted in recurrent upper airway obstruction, leading to aerophagia and associated clinical morbidity. These data show the nasal cavity is a target of zibotentan when given by gavage in athymic nude mice, and such unanticipated and off-target effects could impact interpretation of research results and animal health in preclinical studies.

Pharmacokinetics of a Transdermal Fentanyl Solution in Suffolk Sheep (Ovis aries).

Sheep used as surgical models require appropriate pain management, and the commonly used transdermal fentanyl patches require a long predosing period to achieve adequate plasma concentrations. The aim of this study was to assess the pharmacokinetic parameters of an FDA-approved transdermal fentanyl solution (TFS) that has yet to be tested in sheep. In this study, we compared TFS at 2.7 mg/kg (n = 2), 1.7 mg/kg (n = 3), and 0.5 mg/kg (n = 3) with the control fentanyl patch at 2 µg/kg/h (n = 1); both products were applied topically to the intrascapular region. Plasma concentrations showed significant interanimal variability. Severe adverse effects occurred at both 2.7 and 1.7 mg/kg TFS and mild to moderate adverse effects were noted at 0.5 mg/kg. At all 3 doses, TFS had greater maximal concentration, clearance rate, and volume of distribution; shorter time to maximal concentration; and similar half-lives to those of the patch. In addition, we validated the use of a commercial human fentanyl ELISA kit, which positively correlated with the liquid chromatography-mass spectroscopy data, but absolute values did not match. Overall, at all 3 dosages tested (0.5, 1.7, and 2.7 mg/kg), TFS delivered fentanyl plasma concentrations that exceeded the minimal effective concentration; however, adverse effects were noted at all 3 dosages. Caution and further study are required before the use of TFS in sheep can be recommended fully.

Institutional Oversight of Occupational Health and Safety for Research Programs Involving Biohazards.

Research with hazardous biologic materials (biohazards) is essential to the progress of medicine and science. The field of microbiology has rapidly advanced over the years, partially due to the development of new scientific methods such as recombinant DNA technology, synthetic biology, viral vectors, and the use of genetically modified animals. This research poses a potential risk to personnel as well as the public and the environment. Institutions must have appropriate oversight and take appropriate steps to mitigate the risks of working with these biologic hazards. This article will review responsibilities for institutional oversight of occupational health and safety for research involving biologic hazards.

Prevalence and diagnosis of hemotrophic mycoplasma infection in research sheep and its effects on hematology variables and erythrocyte membrane fragility.

Hemotrophic mycoplasma (hemoplasma) infection in research sheep can confound experimental results and contribute to morbidity and mortality. Prevalence and clinicopathologic studies historically relied on blood-smear diagnosis, but systematic studies using current molecular techniques are warranted. Here we sought to report the prevalence of subclinical infection in our study population, compare diagnostic sensitivity and specificity between blood smears and a PCR assay, and determine the effects of infection on CBC variables and erythrocyte membrane fragility. We collected whole-blood samples from 111 convenience-sampled research sheep. All samples were tested for hemoplasmas by using a PCR assay, blood smears were evaluated for visual presence of hemoplasmas, and CBC and osmotic fragility assays were performed. Subclinical prevalence, according to PCR diagnosis, was 14.1% (14 of 99) in our study population. Relative to the PCR assay, blood-smear diagnosis was 8.3% sensitive and 100% specific for hemoplasma detection. Subclinical infection was associated with changes in MCV, MCHC, RBC distribution width, and absolute monocyte count. Acute infection was associated with changes in RBC mass, Hgb concentration, MCV, MCH, MCHC, and absolute lymphocyte and monocyte counts. Acute infection was associated with increased mean erythrocyte fragility compared with that in uninfected control and treated sheep. We demonstrated that hemoplasma infection is common in our study population, blood-smear evaluation is insensitive at detecting infection, and infection is associated with changes in CBC variables and increased erythrocyte membrane fragility. These findings raise concerns regarding the suitability of hemoplasma-infected sheep for biomedical research.

Complete Genome Sequence of Mycoplasma ovis Strain Michigan, a Hemoplasma of Sheep with Two Distinct 16S rRNA Genes.

We report the complete genome sequence of Mycoplasma ovis strain Michigan. Its single circular chromosome has 702,511 bp and contains 2 copies of the 16S rRNA gene, one corresponding to M. ovis and the other to "Candidatus Mycoplasma haemovis." All housekeeping genes and the 5S-23S rRNA genes are present in single copies.

Institutional training programs for research personnel conducted by laboratory-animal veterinarians.

Research institutions are required by federal law and national standards to ensure that individuals involved in animal research are appropriately trained in techniques and procedures used on animals. Meeting these requirements necessitates the support of institutional authorities; policies for the documentation and enforcement of training; resources to support and provide training programs; and high-quality, effective educational material. Because of their expertise, laboratory-animal veterinarians play an essential role in the design, implementation, and provision of educational programs for faculty, staff, and students in biomedical research. At large research institutions, provision of a training program for animal care and use personnel can be challenging because of the animal-research enterprise's size and scope. At the University of Michigan (UM), approximately 3,500 individuals have direct contact with animals used in research. We describe a comprehensive educational program for animal care and use personnel designed and provided by laboratory-animal veterinarians at UM and discuss the challenges associated with its implementation.

Flushing induction chambers used for rodent anesthesia to reduce waste anesthetic gas.

Anesthetic induction chambers used for medical research are a substantial source of waste anesthetic gas (WAG). Ideally, any generated waste gas should be actively vented away from personnel operating the chamber by either a ventilated hood or snorkel. Unfortunately, the ideal environment for anesthetizing rodents is not always available. In an effort to create a safer environment, the authors designed a system to reduce WAG. This system is portable, can be adapted to different precision vaporizing anesthetic systems and fits in a variety of physical locations. The system flushes anesthetic gas out of an induction chamber before operators open the chamber. To ensure that the system was adequately flushing the anesthetic gas, the authors measured WAG concentration in the environment above the induction chamber and directly behind the vent of an activated charcoal filter. They also compared the efficiency of the filters in vertical and horizontal positions. Finally, they measured the recovery time for mice and rats after flushing the anesthetic gas from an induction chamber. The results show that flushing the induction chamber was an inexpensive and effective method for reducing WAG accumulation in the air surrounding the chamber.

Management of an outbreak of rat theilovirus.

Rat theilovirus is a commonly reported infection in research rat colonies. The author's institution experienced an outbreak of rat theilovirus in a breeding colony of unique outbred rats. To manage this outbreak, the institution chose to use a 'test and cull' strategy because this approach is reported to be successful in mouse colonies infected with Theiler's murine encephalomyelitis virus, a related virus. Here the author describes the outbreak and subsequent management of rat theilovirus. The strategy successfully cleared the virus from the rat colony.

Helicobacter spp. in wild mice (Peromyscus leucopus) found in laboratory animal facilities.

Wild rodents are a potential source for pathogen introduction into laboratory animal research facilities. A study was designed to assess wild mice found at our institution by infectious disease surveillance. Wild white-footed mice (Peromyscus leucopus) were captured with live capture traps placed in areas in which wild mice had been reported in several animal facilities. Captured animals were euthanized by inhalation of CO(2), blood was collected by cardiocentesis (n = 10), and necropsy was performed (n = 8). Serum samples were negative for antibodies to mouse parvovirus (types 1 and 2), mouse minute virus, Sendai virus, pneumonia virus of mice, mouse hepatitis virus, Theiler murine encephalomyelitis virus, reovirus, rotavirus, lymphocytic choriomeningitis virus, mouse adenovirus, ectromelia virus, K virus, cilia-associated respiratory bacillus, and Mycoplasma pulmonis. Of the 8 animals that were necropsied, pelt and cecal examinations were negative for ectoparasites and pinworms, respectively. Histopathologic examination of brain, heart, lungs, liver, kidney, spleen, stomach, and small intestine revealed bacteria morphologically compatible with Helicobacter spp. in the cecal and colonic glands and occasionally in the gastric lumen and pits. Mesenteric lymph nodes and feces from 8 of the animals were submitted for PCR analysis for the detection of mouse parvovirus, mouse minute virus, mouse hepatitis virus, and Helicobacter spp.; 7 of the samples were PCR-positive for Helicobacter spp. At this time, wild mice found in our animal facilities do not appear to be a significant source of common laboratory mouse viral pathogens. However, they are a potential source of Helicobacter infections.

Differential susceptibility of C57BL/6NCr and B6.Cg-Ptprca mice to commensal bacteria after whole body irradiation in translational bone marrow transplant studies.

BACKGROUND: The mouse is an important and widely utilized animal model for bone marrow transplant (BMT) translational studies. Here, we document the course of an unexpected increase in mortality of congenic mice that underwent BMT. METHODS: Thirty five BMTs were analyzed for survival differences utilizing the Log Rank test. Affected animals were evaluated by physical examination, necropsy, histopathology, serology for antibodies to infectious disease, and bacterial cultures. RESULTS: Severe bacteremia was identified as the main cause of death. Gastrointestinal (GI) damage was observed in histopathology. The bacteremia was most likely caused by the translocation of bacteria from the GI tract and immunosuppression caused by the myeloablative irradiation. Variability in groups of animals affected was caused by increased levels of gamma and X-ray radiation and the differing sensitivity of the two nearly genetically identical mouse strains used in the studies. CONCLUSION: Our retrospective analysis of thirty five murine BMTs performed in three different laboratories, identified C57BL/6NCr (Ly5.1) as being more radiation sensitive than B6.Cg-Ptprca/NCr (Ly5.2). This is the first report documenting a measurable difference in radiation sensitivity and its effects between an inbred strain of mice and its congenic counterpart eventually succumbing to sepsis after BMT.

Components of metabolic syndrome and coronary artery disease in female Ossabaw swine fed excess atherogenic diet.

Ossabaw swine have a 'thrifty genotype' (propensity to obesity) that enables them to survive seasonal food shortages in their native environment. Consumption of excess kcal causes animals of the thrifty genotype to manifest components of the metabolic syndrome, including central (intra-abdominal) obesity, insulin resistance, impaired glucose tolerance, dyslipidemia, and hypertension. We determined whether female Ossabaw swine manifest multiple components of the metabolic syndrome by comparing lean pigs fed a normal maintenance diet (7% kcal from fat; lean, n = 9) or excess chow with 45% kcal from fat and 2% cholesterol (obese, n = 8). After 9 wk, body composition, glucose tolerance, plasma lipids, and intravascular ultrasonography and histopathology of coronary arteries were assessed. Computed tomography (CT) assessed subcutaneous and intra-abdominal fat deposition and was compared with traditional methods, including anatomical measurements, backfat ultrasonography, and proximate chemical composition analysis. Compared with lean animals, obese swine showed 2-fold greater product of the plasma insulin x glucose concentrations, 4.1-fold greater total cholesterol, 1.6-fold greater postprandial triglycerides, 4.6-fold greater low- to high-density lipoprotein cholesterol ratio, hypertension, and neointimal hyperplasia of coronary arteries. The 1.5-fold greater body weight in obese swine was largely accounted for by the 3-fold greater carcass fat mass. High correlation (0.79 to 0.95) of CT, anatomical measurements, and ultrasonography with direct chemical measures of subcutaneous, retroperitoneal, and visceral fat indicates high validity of all indirect methods. We conclude that relatively brief feeding of excess atherogenic diet produces striking features of metabolic syndrome and coronary artery disease in female Ossabaw swine.