@article{feng_tompkins_xu_zhang_mccaw_2003, title={Analysis of constitutive cytokine expression by pigs infected in-utero with porcine reproductive and respiratory syndrome virus}, volume={94}, ISSN={["0165-2427"]}, DOI={10.1016/S0165-2427(03)00059-X}, abstractNote={To investigate cytokine alterations in pigs infected in-utero with porcine reproductive and respiratory syndrome virus (PRRSV), constitutive mRNA expression by peripheral blood mononuclear cells (PBMCs) was measured. PBMC from in-utero PRRSV-infected pigs displayed significantly increased IL-6, IL-10, and IFN-γ mRNA expression at 0 and 14 days of age compared with age-matched control pigs. There were no significant differences in IL-2, IL-4, and IL-12 mRNA expression between in-utero PRRSV-infected and control pigs. However, the IL-10/IL-12 ratio was significantly increased in in-utero PRRSV-infected pigs at 0 and 14 days of age, suggesting the imbalance of IL-10 and IL-12 mRNA production. The abnormal mRNA expression of cytokines in in-utero PRRSV-infected pigs occurred concurrently with a significant decrease in the CD4+/CD8+ T-cell ratio in peripheral blood. PRRSV was not isolated from the sera of pigs at 9 weeks of age that had been viremic at 0 and 14 days old. Delayed type hypersensitivity (DTH) responses to Tuberculin and analysis of cytokine mRNA expression by PBMC showed that cell-mediated immune response and cytokine message profiles in pigs infected in-utero with PRRSV had returned to levels similar to those of control pigs by 9 weeks of age. We conclude that in-utero infection with PRRSV results in significant alteration of cytokine mRNA expression that may cause transient immunomodulation. However, at 10 weeks of age the pigs’ immune responses seemed to recover. This may help to understand the immunopathogenesis of in-utero PRRSV infection and the increased susceptibility to secondary bacterial pathogens in neonatal piglets.}, number={1-2}, journal={VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY}, author={Feng, WH and Tompkins, MB and Xu, JS and Zhang, HX and McCaw, MB}, year={2003}, month={Jul}, pages={35–45} }
 @article{feng_tompkins_xu_brown_laster_zhang_mccaw_2002, title={Thymocyte and peripheral blood T lymphocyte subpopulation changes in piglets following in utero infection with porcine reproductive and respiratory syndrome virus}, volume={302}, ISSN={["0042-6822"]}, DOI={10.1006/viro.2002.1650}, abstractNote={Piglets infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV) are born severely immunocompromised. In this article we more closely examine the effects of in utero PRRSV infection on circulating and thymic T cell populations. Numbers of CD4+, CD8+, and dual-positive lymphocytes were quantitated in circulation and in the thymus during the 2 weeks following birth. At birth we found that the number of circulating lymphocytes was suppressed by 60%. Lymphocyte numbers were also suppressed by 42% at day 7, but by day 14 the number of lymphocytes had rebounded and was actually 47% greater than controls. At birth and day 7, a drop in the number of CD4+ cells could partially explain the suppression we observed, while the rebound in total lymphocyte numbers seen at day 14 was due to a nearly fourfold increase in the number of circulating CD8+ cells. As a result, the normal CD4+:CD8+ ratio of between 1.4 and 2.2 for neonatal pigs was reduced to 0.1-0.5. The thymuses of infected piglets were found to be 50% smaller than those of control pigs and were characterized by cortical involution and severe cortical depletion of thymocytes. Analysis of the population of thymocytes revealed that double-positive thymocytes were suppressed to a greater degree than either single positive subpopulation. In addition, we show that the number of thymocytes undergoing apoptosis was increased twofold in piglets infected with PRRSV. Taken together, these results help explain the dramatic immunosuppression observed in neonatal animals infected in utero with PRRSV.}, number={2}, journal={VIROLOGY}, author={Feng, WH and Tompkins, MB and Xu, JS and Brown, TT and Laster, SM and Zhang, HX and McCaw, MB}, year={2002}, month={Oct}, pages={363–372} }
 @article{feng_laster_tompkins_brown_xu_altier_gomez_benfield_mccaw_2001, title={In utero infection by porcine reproductive and respiratory syndrome virus is sufficient to increase susceptibility of piglets to challenge by Streptococcus suis type II}, volume={75}, ISSN={["1098-5514"]}, DOI={10.1128/JVI.75.10.4889-4895.2001}, abstractNote={ABSTRACT}, number={10}, journal={JOURNAL OF VIROLOGY}, author={Feng, WH and Laster, SM and Tompkins, M and Brown, T and Xu, JS and Altier, C and Gomez, W and Benfield, D and McCaw, MB}, year={2001}, month={May}, pages={4889–4895} }
 @article{mccaw_2000, title={Effect of reducing crossfostering at birth on piglet mortality and performance during an acute outbreak of porcine reproductive and respiratory syndrome}, volume={8}, number={1}, journal={Swine Health and Production}, author={McCaw, M. B.}, year={2000}, pages={15–21} }
 @article{mccaw_osorio_wheeler_xu_erickson_1997, title={Effect of maternally acquired Aujeszky's disease (pseudorabies) virus-specific antibody in pigs on establishment of latency and seroconversion to differential glycoproteins after low dose challenge}, volume={55}, ISSN={["0378-1135"]}, DOI={10.1016/S0378-1135(96)01315-6}, abstractNote={This study investigated whether (1) passively immune pigs could become latently infected after challenge with low doses of wild type pseudorabies virus (PRV) and (2) if seroconversion to PRV could be consistently detected using two commercially available differential diagnostic ELISAs. Three litters of piglets with passively acquired PRV serum neutralizing (SN) antibody (geometric mean titers 47.03 to 95.10) were challenged at 6 to 12 days of age with 236 to 500 TCID50 of Shope strain virus; pigs were vaccinated at 11 weeks of age with a commercially available genetically engineered vaccine (TK− gE− gG− Iowa S62 strain PRV). Vaccination was intended to reduce the risk of reactivation of latent infection resulting in spread of virulent PRV infection to previously uninfected pigs during the experiment. Vaccination at this age also approximated common field practices in infected herds. After 15 weeks, all challenged pigs were seropositive on the PRV glycoprotein (g or gp) E differential ELISA but were seronegative on the gG differential ELISA. All three challenge groups had pigs that were latently infected as evidenced by the detection of PRV DNA by polymerase chain reaction (PCR) assay of their trigeminal ganglia (TG). There was a significant inverse relationship observed for age at challenge and the proportion of PCR positive pigs in the group 15 weeks postchallenge (p = 0.0004). This trend was independent of the passively acquired PRV SN antibody titers at challenge. In this study, passively acquired antibody did not provide protection against establishment of latent infection in piglets after exposure to low doses of virulent PRV. These latent infections were detected serologically by only one of two available differential diagnostic ELISAs.}, number={1-4}, journal={VETERINARY MICROBIOLOGY}, author={McCaw, MB and Osorio, FA and Wheeler, J and Xu, JS and Erickson, GA}, year={1997}, month={Apr}, pages={91–98} }
 @article{mccaw_1996, title={Farm management techniques for control of atrophic rhinitis = Tecniche di gestione dell'allevamento per il controllo della rinite atrofica}, volume={2}, number={1}, journal={Large Animals Review}, author={McCaw, M. B.}, year={1996}, pages={55} }
 @article{mccaw_xu_correa_1995, title={SURVIVAL OF PSEUDORABIES VIRUS ON SWABS MAINTAINED UNDER STANDARD FIELD SAMPLE SHIPPING CONDITIONS}, volume={7}, ISSN={["1040-6387"]}, DOI={10.1177/104063879500700108}, abstractNote={Pseudorabies virus survival was compared using three different types of applicator swabs in Eagle's minimum essential medium held under shipping conditions (packed with frozen gel packs) for up to 96 hours. Virus titer decay rates for dacron-tipped applicators were not statistically different from those of controls. Titer decay rates were statistically different from controls for cotton- and calcium alginate-tipped applicators. With the lowest input virus titer, virus was detectable up to 96, 72, or 24 hours after inoculation for dacron-, cotton-, and calcium alginate-tipped applicators, respectively. Dacron-tipped applicators were chosen to evaluate pseudorabies virus survival on tonsil swabs collected from experimentally challenged or contact control pigs to simulate field sampling and shipping conditions. Virus was still detectable in 20 of 24 swab samples after 72 hours in cell culture medium under shipping conditions.}, number={1}, journal={JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION}, author={MCCAW, MB and XU, JS and CORREA, MT}, year={1995}, month={Jan}, pages={56–59} }
 @article{mccaw_xu_1993, title={Protection against pseudorabies virus infection by intranasal vaccination of newborn pigs}, volume={54}, number={4}, journal={American Journal of Veterinary Research}, author={McCaw, M. B. and Xu, J.}, year={1993}, pages={527} }
 @article{mccaw_molitor_joo_1992, title={Characterization of pseudorabies virus antibody responses in young swine after infection and vaccination by using an immunoglobulin M antibody capture enzyme-linked immunosorbent assay}, volume={30}, number={2}, journal={Journal of Clinical Microbiology}, author={McCaw, M. B. and Molitor, T. W. and Joo, H. S.}, year={1992}, pages={346} }