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Davis, CA, United States

Weiss E.E.,Center for Laboratory Animal Science | Evans K.D.,Center for Comparative Medicine | Griffey S.M.,University of California at Davis
Journal of the American Association for Laboratory Animal Science | Year: 2012

Fur mites were diagnosed in a colony of mice at our research institution. In the current study, we compared the effectiveness of PCR and tape test in a small population of mice at the onset of diagnosis and throughout treatment. Samples were collected 1 d prior to treatment with permethrin impregnated cotton balls and 6 and 12 wk after treatment. PCR confirmed the presence of Myocoptes musculinus and Radfordia affinis or Myobia musculi, but tape test confirmed only the presence of Myocoptes spp. The results of the PCR and tape test agreed 97.2% of the time during active infection on day 1, but only 59.5% and 48.4% of results coincided at 6 and 12 wk after treatment, respectively. At 6 wk, 11 of the 37 samples were PCR-negative but tape-test-positive, compared with 9 of the 31 samples at 12 wk. Our results show that PCR is a reliable diagnostic method during active fur mite infection but that false-negative results are possible after treatment. Negative PCR results after treatment should be interpreted carefully, and a secondary diagnostic method should be considered. Copyright © 2012 by the American Association for Laboratory Animal Science.

Baumgarth N.,University of California at Davis | Waffarn E.E.,Center for Comparative Medicine | Nguyen T.T.,Center for Comparative Medicine
Annals of the New York Academy of Sciences | Year: 2015

Mouse B-1 cells are not only major producers of steady-state natural antibodies but also rapid responders to infections and inflammation. These discrete functions may be the outcomes of distinct environmental or developmental triggers that drive B-1 cells toward IgM production or an effector cell fate. Alternatively, distinct B-1 cell subsets may exist, which differ in their functional plasticity. In this paper, we summarize existing data suggesting that B-1 cells form a heterogeneous group of cells with distinct developmental requirements and nonoverlapping functions. Most spleen B-1 cells differ in development from that of bone marrow and peritoneal cavity B-1 cells, in that they develop in the absence of natural IgM. Functional heterogeneity is revealed by findings that B-1 cells in the bone marrow and spleen, but not the peritoneal cavity, generate natural serum IgM, while the latter are rapid responders to inflammatory and infectious insults, resulting in their relocation to secondary lymphoid tissues. A clearer understanding of the developmental and functional differences within the B-1 cell pool may reveal how they might be harnessed for prophylaxis or therapy. © 2015 New York Academy of Sciences.

Gupta S.,University of California at Irvine | Pegu P.,Animal Models and Retroviral Vaccine Section | Venzon D.J.,U.S. National Institutes of Health | Gach J.S.,University of California at Irvine | And 6 more authors.
Journal of Infectious Diseases | Year: 2015

Background. The time to acquisition of simian immunodeficiency virus (SIV) infection following low-dose repeated rectal challenge correlated inversely with the number of transmitted/founder strains among macaques vaccinated with ALVAC-SIV/gp120 or gp120 alone. We determined if the ability of postvaccination, prechallenge sera to enhance SIVmac251 transcytosis across epithelial cells was associated with transmitted/founder strain number. Methods.Transcytosis was carried out by exposing sera and SIVmac251 to the apical surface of human endometrial carcinoma (HEC-1A) cells at pH 6.0 and 12 hours later quantifying virus in fluid bathing the basolateral cell surface (maintained at pH 7.4). These conditions allow Fc neonatal receptor (FcRn)-dependent shuttling of virus across cells. Results.There was a strong correlation between the amount of virus transcytosed and number of transmitted variants (R = 0.86, P <. 0001). We also found that 4 animals who remained uninfected after repeated rectal challenges had lower serum transcytosis activity than did 19 animals who subsequently became infected (P =. 003). Using immunohistochemistry, we demonstrated FcRn on columnar epithelial cells facing the lumen of the macaque rectum. Conclusions.Vaccine-induced antibody capable of enhancing transcytosis in vitro via FcRn may play a role in determining transmitted/founder strain number and infection outcomes following in vivo challenge. © 2014 © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.

Asmuth D.M.,University of California at Davis | Ma Z.-M.,University of California at Davis | Ma Z.-M.,Center for Comparative Medicine | Albanese A.,Veterans Administration Northern California Healthcare System | And 11 more authors.
AIDS | Year: 2013

Objectives: To examine the impact of serum-derived bovine immunoglobulin, an oral medical food known to neutralize bacterial antigen and reduce intestinal inflammation, on restoration of mucosal immunity and gastrointestinal function in individuals with HIV enteropathy. Design: Open-label trial with intensive 8-week phase of bovine serum immunoglobulin (SBI) 2.5 g twice daily with a 4-week washout period and an optional 9-month extension study. Methods: HIV enteropathy was defined as chronic gastrointestinal symptoms including frequent loose or watery stools despite no identifiable, reversible cause. Upper endoscopy for tissue immunofluorescent antibody assay and disaccharide gut permeability/absorption studies were performed before and after 8 weeks of SBI to test mucosal immunity and gastrointestinal function. Blood was collected for markers of microbial translocation, inflammation, and collagen kinetics. A validated gastrointestinal questionnaire assessed changes in symptoms. Results: All eight participants experienced profound improvement in symptoms with reduced bowel movements/day (P=0.008) and improvements in stool consistency (P=0.008). Gut permeability was normal before and after the intervention, but D-xylose absorption increased in seven of eight participants. Mucosal CD4+ lymphocyte densities increased by a median of 139.5 cells/mm2 from 213 to 322 cells/mm2 (P=0.016). Intestinal-fatty acid binding protein (I-FABP), a marker of enterocyte damage, initially rose in seven of eight participants after 8 weeks (P=0.039), and then fell below baseline in four of five who continued receiving SBI (P=0.12). Baseline serum I-FABP levels were negatively correlated with subsequent rise in mucosal CD4+ lymphocyte densities (r= -0.74, P=0.046). Conclusion: SBI significantly increases intestinal mucosal CD4+ lymphocyte counts, improves duodenal function, and showed evidence of promoting intestinal repair in the setting of HIV enteropathy. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Moore M.E.,Center for Comparative Medicine | Boren T.,Umea University | Solnick J.V.,Center for Comparative Medicine
Gut Microbes | Year: 2011

Helicobacter pylori is the primary cause of peptic ulcer disease and is estimated to account for about 60% of all cases of gastric cancer, the second most common cause of cancer death worldwide. Among the H. pylori virulence factors associated with disease, in addition to the well-known cag pathogenicity island, is the BabA adhesin, an outer membrane protein that binds with high affinity to fucosylated glycans on the gastric epithelium, such as Lewis B (Leb) and related terminal fucose residues found on the blood group O (H antigen), A and B antigens. BabA-mediated attachment to the gastric mucosa promotes chronic inflammation and gastric pathology, which from the bacterial perspective carries both risks and benefits. We recently described modulation in expression of BabA and related outer membrane proteins that occurs during colonization of experimental animals.1,2 Here we put these findings into a broader context, and speculate on their implications for the host-pathogen relationship. © 2011 Landes Bioscience.

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