Effect of Husbandry Practices on the Fecal Microbiota of C57BL/6J Breeding Colonies Housed in 2 Different Barrier Facilities in the Same Institution.

Evidence showing a relationship between the mouse gut microbiome and properties such as phenotype and reaction to therapeutic agents and other treatments has increased significantly over the past 20 to 30 y. Recent concerns regarding the reproducibility of animal experiments have underscored the importance of understanding this relationship and how differences in husbandry practices can affect the gut microbiome. The current study focuses on effects of different barrier practices in 2 barrier facilities at the same institution on the fecal microbiome of breeding C57Bl/6J mice.

In Utero Exposure to Benzo[a]pyrene Induces Ovarian Mutations at Doses That Deplete Ovarian Follicles in Mice.

Polycyclic aromatic hydrocarbons like benzo[a]pyrene (BaP) are ubiquitous environmental contaminants formed during incomplete combustion of organic materials. Our prior work showed that transplacental exposure to BaP depletes ovarian follicles and increases prevalence of epithelial ovarian tumors later in life. We used the MutaMouse transgenic rodent model to address the hypothesis that ovarian mutations play a role in tumorigenesis caused by prenatal exposure to BaP.

Charged-Iron-Particles Found in Galactic Cosmic Rays are Potent Inducers of Epithelial Ovarian Tumors.

Astronauts traveling in deep space are exposed to high-charge and energy (HZE) particles from galactic cosmic rays. We have previously determined that irradiation of adult female mice with iron HZE particles induces DNA double-strand breaks, oxidative damage and apoptosis in ovarian follicles, causing premature ovarian failure. These effects occur at lower doses than with conventional photon irradiation.

Evaluation of Anthelmintic Resistance and Exhaust Air Dust PCR as a Diagnostic Tool in Mice Enzootically Infected with .

The entry of infectious agents in rodent colonies occurs despite robust sentinel monitoring programs, strict quarantine measures, and stringent biosecurity practices. In light of several outbreaks with Aspiculuris tetraptera in our facilities, we investigated the presence of anthelmintic resistance and the use of exhaust air dust (EAD) PCR for early detection of A. tetraptera infection.

Ability of mini-implant-facilitated micro-osteoperforations to accelerate tooth movement in rats.

Introduction: Although current techniques for accelerated tooth movement often involve invasive surgical procedures, micro-osteoperforations (MOPs) using mini-implants may facilitate orthodontic tooth movement without raising flaps, reduce surgical risks, and increase patient acceptance. In this study, we evaluated the effectiveness of mini-implant-facilitated MOPs in inducing accelerated tooth movement and investigated the potential risks for root resorption.

Methods: Five MOPs were placed on the left side around the maxillary first molars in 6 rats using an automated mini-implant driver, whereas the right side received no MOPs as the control.

Factors in the Selection of Surface Disinfectants for Use in a Laboratory Animal Setting.

Because surface disinfectants are an important means of pathogen control within laboratory animal facilities, these products must have an appropriate spectrum of antimicrobial activity. However, many other factors must also be considered, including effects on human health, environmental safety, and animal behavior. Aqueous solutions of sodium hypochlorite often are considered to be the 'gold standard' for surface disinfection, but these products can be corrosive, caustic, and aversive in odor.

Comparison of the protective effect of a commercially available western diamondback rattlesnake toxoid vaccine for dogs against envenomation of mice with western diamondback rattlesnake (Crotalus atrox), northern Pacific rattlesnake (Crotalus oreganus oreganus), and southern Pacific rattlesnake (Crotalus oreganus helleri) venom.

Objective: To evaluate effectiveness of a commercially available toxoid manufactured from western diamondback (WD) rattlesnake (Crotalus atrox) venom against envenomation of mice with WD, northern Pacific (NP) rattlesnake (Crotalus oreganus oreganus), and southern Pacific (SP) rattlesnake (Crotalus oreganus helleri) venom.

Animals: 90 specific pathogen-free female mice.

Procedures: Mice were allocated into 3 cohorts (30 mice/cohort).

Core body temperature as adjunct to endpoint determination in murine median lethal dose testing of rattlesnake venom.

Median lethal dose (LD50) testing in mice is the 'gold standard' for evaluating the lethality of snake venoms and the effectiveness of interventions. As part of a study to determine the murine LD50 of the venom of 3 species of rattlesnake, temperature data were collected in an attempt to more precisely define humane endpoints. We used an 'up-and-down' methodology of estimating the LD50 that involved serial intraperitoneal injection of predetermined concentrations of venom.

Validation of an HPV16-mediated carcinogenesis mouse model.

Background/aim: Human papillomavirus Type 16 (HPV16) infection is a necessary but alone insufficient cause of invasive cervical cancer (ICC) and likely causes other genital cancers. Individual genetic variability influences the natural history of the neoplasm. Developing a variety of animal models to investigate HPV16-mediated carcinogenesis is important to Phase 1 trials for human cancer treatments.

The use of eutectic mixture of lidocaine and prilocaine in mice (Mus musculus) for tail vein injections.

Objective: To investigate a topical local anesthesia technique as a means to prevent and/or diminish pain in mice in a laboratory setting associated with tail vein injections performed by personnel in training.

Study Design: Prospective, randomized experimental trial.

Animals: Thirty six adult female, 23-28 g CD-1 mice from an in-house training colony.

Selective regulation of lymphopoiesis and leukemogenesis by individual zinc fingers of Ikaros.

C2H2 zinc fingers are found in several key transcriptional regulators in the immune system. However, these proteins usually contain more fingers than are needed for sequence-specific DNA binding, which suggests that different fingers regulate different genes and functions. Here we found that mice lacking finger 1 or finger 4 of Ikaros exhibited distinct subsets of the hematological defects of Ikaros-null mice.

Increased abscess formation and defective chemokine regulation in CREB transgenic mice.

Cyclic AMP-response element-binding protein (CREB) is a transcription factor implicated in growth factor-dependent cell proliferation and survival, glucose homeostasis, spermatogenesis, circadian rhythms, and synaptic plasticity associated with memory. To study the phenotype of CREB overexpression in vivo, we generated CREB transgenic (TG) mice in which a myeloid specific hMRP8 promoter drives CREB expression. CREB TG mice developed spontaneous skin abscesses more frequently than wild type (WT) mice.

Palatability and treatment efficacy of various ibuprofen formulations in C57BL/6 mice with ulcerative dermatitis.

Ibuprofen, a nonsteroidal antiinflammatory drug, is a nonselective inhibitor of cyclooxygenases 1 and 2 that commonly is used for its analgesic, antiinflammatory, and antipyretic properties. We compared the palatability and efficacy of medicated water containing ibuprofen from an oral pediatric suspension or liqui-gel capsules in C57BL/6 and genetically engineered mice of C57BL/6 background with ulcerative dermatitis. Mice (n = 14 or 15 per group) with ulcerated skin lesions of similar average size (capsule group, 6.

Glutathione-deficient mice have increased sensitivity to transplacental benzo[a]pyrene-induced premature ovarian failure and ovarian tumorigenesis.

Polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyrene (BaP) are ubiquitous environmental pollutants found in tobacco smoke, air pollution, and grilled foods. Prenatal exposure to BaP causes premature reproductive senescence in mice, and other PAHs are transplacental ovarian carcinogens. Glutathione (GSH) is critical for detoxification of the reactive metabolites of PAHs.

Outer membrane vesicles of a human commensal mediate immune regulation and disease protection.

Commensal bacteria impact host health and immunity through various mechanisms, including the production of immunomodulatory molecules. Bacteroides fragilis produces a capsular polysaccharide (PSA), which induces regulatory T cells and mucosal tolerance. However, unlike pathogens, which employ secretion systems, the mechanisms by which commensal bacteria deliver molecules to the host remain unknown.

The XX sex chromosome complement in mice is associated with increased spontaneous lupus compared with XY.

Objectives: Many autoimmune diseases are characterised by a female predominance. This may be caused by sex hormones, sex chromosomes or both. This report uses a transgenic mouse model to investigate how sex chromosome complement, not confounded by differences in gonadal type, might contribute to lupus pathogenesis.

Increased sensitivity to testicular toxicity of transplacental benzo[a]pyrene exposure in male glutamate cysteine ligase modifier subunit knockout (Gclm-/-) mice.

Polycyclic aromatic hydrocarbons (PAHs), like benzo[a]pyrene (BaP), are ubiquitous environmental pollutants formed by the incomplete combustion of organic materials. The tripeptide glutathione (GSH) is a major antioxidant and is important in detoxification of PAH metabolites. Mice null for the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in GSH synthesis, have decreased GSH concentrations.

Inhibiting microRNA-192 ameliorates renal fibrosis in diabetic nephropathy.

TGF-β1 upregulates microRNA-192 (miR-192) in cultured glomerular mesangial cells and in glomeruli from diabetic mice. miR-192 not only increases collagen expression by targeting the E-box repressors Zeb1/2 but also modulates other renal miRNAs, suggesting that it may be a therapeutic target for diabetic nephropathy. We evaluated the efficacy of a locked nucleic acid (LNA)-modified inhibitor of miR-192, designated LNA-anti-miR-192, in mouse models of diabetic nephropathy.

Severe hepatocellular disease in mice lacking one or both CaaX prenyltransferases.

Protein farnesyltransferase (FTase) and protein geranylgeranyltransferase-I (GGTase-I) add 15- or 20-carbon lipids, respectively, to proteins that terminate with a CaaX motif. These posttranslational modifications of proteins with lipids promote protein interactions with membrane surfaces in cells, but the in vivo importance of the CaaX prenyltransferases and the protein lipidation reactions they catalyze remain incompletely defined. One study concluded that a deficiency of FTase was inconsequential in adult mice and led to little or no tissue pathology.

Combined preconditioning and in vivo chemoselection with 6-thioguanine alone achieves highly efficient reconstitution of normal hematopoiesis with HPRT-deficient bone marrow.

Purine analogs such as 6-thioguanine (6TG) cause myelotoxicity upon conversion into nucleotides by hypoxanthine-guanine phosphoribosyltransferase (HPRT). Here we have developed a novel and highly efficient strategy employing 6TG as a single agent for both conditioning and in vivo chemoselection of HPRT-deficient hematopoietic stem cells. The dose-response and time course of 6TG myelotoxicity were first compared in HPRT wild-type mice and HPRT-deficient transgenic mice.

ORAI1 deficiency impairs activated T cell death and enhances T cell survival.

ORAI1 is a pore subunit of Ca(2+) release-activated Ca(2+) channels that mediate TCR stimulation-induced Ca(2+) entry. A point mutation in ORAI1 (ORAI1(R91W)) causes SCID in human patients that is recapitulated in Orai1(-/-) mice, emphasizing its important role in the immune cells. In this study, we have characterized a novel function of ORAI1 in T cell death.

Association between hair-induced oronasal inflammation and ulcerative dermatitis in C57BL/6 mice.

Ulcerative dermatitis (UD) is a genetically linked syndrome that affects the neck, torso, and facial regions of C57BL/6 mice and strains with C57BL/6 background. In this study, 96 mice with skin ulcerations in 3 different regions of the body and 40 control animals without ulcerated lesions were evaluated histologically for the presence of hair-induced inflammation in the oronasal cavity. We found that 73.