Melissa C. Dyson

B cell–deficient NOD.H-2h4 mice have CD4+CD25+ T regulatory cells that inhibit the development of spontaneous autoimmune thyroiditis

Wild-type (WT) NOD.H-2h4 mice develop spontaneous autoimmune thyroiditis (SAT) when given 0.05% NaI in their drinking water, whereas B cell–deficient NOD.H-2h4 mice are SAT resistant. To test the hypothesis that resistance of B cell–deficient mice to SAT was due to the activity of regulatory CD4+CD25+ T (T reg) cells activated if autoantigen was initially presented on non–B cells, CD25+ T reg cells were transiently depleted in vivo using anti-CD25. B cell–deficient NOD.H-2h4 mice given three weekly injections of anti-CD25 developed SAT 8 wk after NaI water. Thyroid lesions were similar to those in WT mice except there were no B cells in thyroid infiltrates. WT and B cell–deficient mice had similar numbers of CD4+CD25+Foxp3+ cells. Mice with transgenic nitrophenyl-specific B cells unable to secrete immunoglobulin were also resistant to SAT, and transient depletion of T reg cells resulted in severe SAT with both T and B cells in thyroid infiltrates. T reg cells that inhibit SAT were eliminated by day 3 thymectomy, indicating they belong to the subset of naturally occurring T reg cells. However, T reg cell depletion did not increase SAT severity in WT mice, suggesting that T reg cells may be nonfunctional when effector T cells are activated; i.e., by autoantigen-presenting B cells.

Preanesthesia, Anesthesia, Analgesia, and Euthanasia

The purpose of this chapter is to provide practical advice for administering anesthetics, analgesics, and euthanasia agents to the most commonly used laboratory animal species. It is not meant to be an exhaustive review of all anesthetic and analgesic protocols used in these species. More detailed information is available in both specialist laboratory animal anesthesia texts, (e.g., Fish et al., 2008; Kohn et al., 1997; Flecknell, 2009), and general veterinary anesthesia texts (e.g., Lumb and Jones, 2007).

Effects of stream acidification on lotic salamander assemblages in a coal-mined watershed in the Cumberland Plateau

We studied the effects of acid mine drainage (AMD) from abandoned coal mines on lotic salamanders and environmental conditions in the upper watershed (Cumberland Plateau) of North Chickamauga Creek (NCC; Tennessee River drainage) in southeastern Tennessee, USA, from 1996–97. Study sites (2nd- or 3rd-order reaches) were sampled in an AMD-influenced section (five sites) and in two reference streams (two minimally disturbed sites). A total of 212 plethodontids (premetamorphic larvae) representing four species were collected by kicknetting in riffles (n = 99) and electrofishing in mixed habitats (n = 113). The dusky salamander (Desmognathus fuscus) was the most abundant species in both AMD and reference reaches (> 80 – 90% of total catches), successively followed by the southern two-lined salamander (Eurycea cirrigera), spring salamander (Gyrinophilus porphyriticus), and red salamander (Pseudotriton ruber). Mining-influenced reaches were characterized by acidic flows (mean pH = 3.8–5.6), zero to low alkalinity, and elevated conductivity, sulfate, hardness, aluminum, and manganese, as well as very low abundances of salamanders. Reference reaches were slightly acidic to circumneutral (mean pH = 6.0–6.9) with low to moderate alkalinity, low levels of conductivity, hardness, sulfate, and metals, and high salamander abundances. Our findings document the impact of acid/metal pollution from past coal mining activities on lotic salamanders in a Cumberland Plateau stream.

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

BackgroundThe 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.MethodsThirty 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.ResultsSevere 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.ConclusionOur 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.

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

ABSTRACT 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.

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.

Chapter 22 – Preanesthesia, Anesthesia, Analgesia, and Euthanasia

The purpose of this chapter is to provide practical advice for administering anesthetics, analgesics, and euthanasia agents to the most commonly used laboratory animal species. It is not meant to be an exhaustive review of all anesthetic and analgesic protocols used in these species. More detailed information is available in both specialist laboratory animal anesthesia texts, (e.g., Fish et al., 2008; Kohn et al., 1997; Flecknell, 2009), and general veterinary anesthesia texts (e.g., Lumb and Jones, 2007).

Institutional Responsibilities for the Oversight of Personnel Safety in Animal Research

Research programs utilizing animal models present a wide variety of risks to personnel safety. These risks stem from a range of hazards including well-recognized physical, chemical, or infectious hazards to novel or less-well defined hazards associated with new and emerging technologies. Institutions must provide appropriate oversight of occupational health and safety programs to help prevent and recognize personnel injury or illness. In this article, we review institutional responsibilities pertaining to animal research safety programs including their regulatory basis and practices necessary for their effective oversight.

Chapter 24 – Preanesthesia, Anesthesia, Analgesia, and Euthanasia

The purpose of this chapter is to provide practical advice for administering anesthetics, analgesics, and euthanasia agents to the most commonly used laboratory animal species. It is not meant to be an exhaustive review of all anesthetic and analgesic protocols used in these species. More detailed information is available in both specialist laboratory animal anesthesia texts, (e.g., Fish et al., 2008; Kohn et al., 1997; Flecknell, 2009), and general veterinary anesthesia texts (e.g., Lumb and Jones, 2007).