23 research outputs found

    Immune Response to the West Nile Virus in Aged Non-Human Primates

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    Background: Risk of encephalitis from West Nile virus (WNV) infection increases dramatically with age. Understanding the basis of this susceptibility requires development of suitable animal models. Here, we investigated the immune response to WNV in old non-human primates. Methodology/Principal Findings: We investigated clinical, immunological and virological correlates of WNV infection in aging non-human primates. Aged (17-30yrs) and adult (6-9yrs) Rhesus macaques (RM) were challenged with WNV in the presence or the absence of the mosquito salivary gland extract (SGE) to approximate natural infection. None of the 26 animals exhibited clinical signs of the disease. Quantitative PCR suggested discrete and short-lived viremia, but infectious virus was never isolated. There was markedly increased, age-independent, proliferation of CD3- non-B cells, followed by Bcell proliferation, which correlated to the loss of detectable WNV genomes. Moreover, animals primed with mosquito salivary gland extract exhibited reduced circulating WNV RNA. While we found the expected age-associated reduction in T cell proliferation, adaptive immunity did not correlate with infection outcome. That was further confirmed in a cohort of thymectomized and/or CD8 T-cell depleted Cynomolgus macaques (CM; N = 15), who also failed to develop WNV disease. Conclusions/significance: Results are consistent with strong and age-independent innate resistance of macaques against WNV challenge. This animal model is therefore not suitable for vaccine and therapeutic testing against WNV. However, understanding the basis of their innate resistance against WNV in macaques could provide helpful clues to improve anti- WNV protection of older adults. © 2010 Wertheimer et al

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

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    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Compression failure morphology of linerboard. Project 2695-20, report two : a progress report to the Fourdrinier Kraft Board Group of the American Paper Institute

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    "March 15, 1981.""The Institute of Paper Chemistry, Jerald A. Watt, Gary A. Baum, Clyde H. Sprague.

    Rhesus macaque rhadinovirus-associated non-Hodgkin lymphoma: animal model for KSHV-associated malignancies

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    Rhesus macaque rhadinovirus (RRV) is closely related to Kaposi sarcoma-associated herpesvirus (KSHV) and is associated with the development of B-cell hyperplasia and persistent lymphadenopathy resembling multicentric Castleman disease in rhesus macaques (RMs) coinfected with simian immunodeficiency virus (SIV). Here we investigated whether RMs experimentally infected with SIV and RRV can develop other disease manifestations observed in HIV- and KSHV-infected patients. As reported earlier, inoculation of SIV-infected RMs with RRV results in persistent RRV infection, whereas immunocompetent animals infected with RRV exhibit viremia 2 weeks after infection, followed by a period of no virus detection until they are subsequently made immunodeficient by SIV infection. A subset of animals developed abnormal cellular proliferations characterized as extranodal lymphoma and a proliferative mesenchymal lesion. In situ hybridization and immunohistochemistry analysis indicate RRV is present in both malignancies, and DNA microarray analysis detected viral interleukin-6 (vIL-6) and viral FLICE-like inhibitory protein (vFLIP) transcripts. Reverse-transcriptase polymerase chain reaction analysis confirmed vIL-6 and vFLIP expression, and that of RRV open reading frames 72 and 73, homologs of KSHV open reading frames shown to be expressed in primary effusion lymphoma. These data support the utility of the RRV-/SIV-infected RM as an excellent animal model to investigate KSHV-like pathogenesis

    Analysis of cell cycle markers suggests an age associated delay in CD4+ proliferation.

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    <p>We used multi-parameter flow cytometry to evaluate the proliferation kinetics of CD4+ cells in each of our cohorts. The dark lines illustrate the two old animals whereas the lighter lines illustrate the two adult animals. The cell cycling is normalized to the baseline cycling recorded during this challenge for each animal, setting this to 0%. This illustration reveals that post WNV infection CD4+ cell cycling decreased followed by a marked increase on days 7, 10 and 14 which then wanes. Of particular interest is the age associated shift in kinetics both older animals (dashed lines) had a slower increase in CD4+ cycling than the adult animals (solid lines) and a prolonged phase prior to returning to a steady state post infection.</p

    Immunodeficient animals – CD8 depleted animals survive WNV infection.

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    <p>CD8+ Tcells from previously thymectomized and CD8 depleted animals were enumerated from total PBMC using multi-parameter flow cytometry prior to WNV infection. Twelve months prior to infection animals were thymectomized (N = 4), thymectomized and CD8 depleted (N = 4), only CD8 depleted (N = 3) or controls (N = 4) (dark filled circles) Light circles illustrate thymectomized animals, dark circles illustrate control (sham operated) animals and light filled circles represent CD8 depletion.</p
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