282 research outputs found

    Lactate Dehydrogenase-Elevating Virus Induces Systemic Lymphocyte Activation via TLR7-Dependent IFNα Responses by Plasmacytoid Dendritic Cells

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    BACKGROUND:Lactate dehydrogenase-elevating virus (LDV) is a natural infectious agent of mice. Like several other viruses, LDV causes widespread and very rapid but transient activation of both B cells and T cells in lymphoid tissues and the blood. The mechanism of this activation has not been fully described and is the focus of the current studies. PRINCIPAL FINDINGS:A known inducer of early lymphocyte activation is IFNalpha, a cytokine strongly induced by LDV infection. Neutralization of IFNalpha in the plasma from infected mice ablated its ability to activate lymphocytes in vitro. Since the primary source of virus-induced IFNalpha in vivo is often plasmacytoid dendritic cells (pDC's), we depleted these cells prior to LDV infection and tested for lymphocyte activation. Depletion of pDC's in vivo eradicated both the LDV-induced IFNalpha response and lymphocyte activation. A primary receptor in pDC's for single stranded RNA viruses such as LDV is the toll-like receptor 7 (TLR7) pattern recognition receptor. Infection of TLR7-knockout mice revealed that both the IFNalpha response and lymphocyte activation were dependent on TLR7 signaling in vivo. Interestingly, virus levels in both TLR7 knockout mice and pDC-depleted mice were indistinguishable from controls indicating that LDV is largely resistant to the systemic IFNalpha response. CONCLUSION:Results indicate that LDV-induced activation of lymphocytes is due to recognition of LDV nucleic acid by TLR7 pattern recognition receptors in pDC's that respond with a lymphocyte-inducing IFNalpha response

    Sequential and Spontaneous Star Formation Around the Mid-Infrared Halo HII Region KR 140

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    We use 2MASS and MSX infrared observations, along with new molecular line (CO) observations, to examine the distribution of young stellar objects (YSOs) in the molecular cloud surrounding the halo HII region KR 140 in order to determine if the ongoing star-formation activity in this region is dominated by sequential star formation within the photodissociation region (PDR) surrounding the HII region. We find that KR 140 has an extensive population of YSOs that have spontaneously formed due to processes not related to the expansion of the HII region. Much of the YSO population in the molecular cloud is concentrated along a dense filamentary molecular structure, traced by C18O, that has not been erased by the formation of the exciting O star. Some of the previously observed submillimetre clumps surrounding the HII region are shown to be sites of recent intermediate and low-mass star formation while other massive starless clumps clearly associated with the PDR may be the next sites of sequential star formation.Comment: Accepted for publication in MNRAS, 8 pages, 10 figure

    Radio polarimetric imaging of the interstellar medium: magnetic field and diffuse ionized gas structure near the W3/W4/W5/HB3 complex

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    We have used polarimetric imaging to study the magneto-ionic medium of the Galaxy, obtaining 1420 MHz images with an angular resolution of 1' over more than 40 square-degrees of sky around the W3/W4/W5/HB3 HII region/SNR complex in the Perseus Arm. Features detected in polarization angle are imposed on the linearly polarized Galactic synchrotron background emission by Faraday rotation arising in foreground ionized gas having an emission measure as low as 1 cm^{-6} pc. Several new remarkable phenomena have been identified, including: mottled polarization arising from random fluctuations in a magneto-ionic screen that we identify with a medium in the Perseus Arm, probably in the vicinity of the HII regions themselves; depolarization arising from very high rotation measures (several times 10^3 rad m^{-2}) and rotation measure gradients due to the dense, turbulent environs of the HII regions; highly ordered features spanning up to several degrees; and an extended influence of the HII regions beyond the boundaries defined by earlier observations. In particular, the effects of an extended, low-density ionized halo around the HII region W4 are evident, probably an example of the extended HII envelopes postulated as the origin of weak recombination-line emission detected from the Galactic ridge. Our polarization observations can be understood if the uniform magnetic field component in this envelope scales with the square-root of electron density and is 20 microG at the edge of the depolarized region around W4, although this is probably an over-estimate since the random field component will have a significant effect.Comment: 18 pages, 8 figures (7 jpeg and 1 postscript), accepted for publication in the Astrophysical Journa

    Yellow fever vaccine viremia following ablative BM suppression in AML

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    Univ São Paulo, Sch Med, Dept Infect & Parasit Dis, São Paulo, BrazilHosp Sirio Libanes, São Paulo, BrazilUniv São Paulo, Sch Med, Div Clin Immunol & Allergy, São Paulo, BrazilFundacao Prosangue Hemoctr São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Infect Dis Div DIPA, São Paulo, BrazilFundacao Oswaldo Cruz, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Infect Dis Div DIPA, São Paulo, BrazilWeb of Scienc

    The HII Region KR 140: Spontaneous Formation of a High Mass Star

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    We have used a multiwavelength data set from the Canadian Galactic Plane Survey (CGPS) to study the Galactic HII region KR 140, both on the scale of the nebula itself and in the context of the star forming activity in the nearby W3/W4/W5 complex of molecular clouds and HII regions. From both radio and infrared data we have found a covering factor of about 0.5 for KR 140 and we interpret the nebula as a bowl-shaped region viewed close to face on. Extinction measurements place the region on the near side of its parent molecular cloud. The nebula is kept ionized by one O8.5 V(e) star, VES 735, which is less than a few million years old. CO data show that VES 735 has disrupted much of the original molecular cloud for which the estimated mass and density are about 5000 MM_{\odot} and 100 cm3^{-3}, respectively. KR 140 is isolated from the nearest star forming activity, in W3. Our data suggest that KR 140 is an example of spontaneous (i.e., non-triggered) formation of, unusually, a high mass star.Comment: 46 pages; includes 15 figures; accepted by the Ap

    HIV-1/HSV-2 Co-Infected Adults in Early HIV-1 Infection Have Elevated CD4+ T Cell Counts

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    Introduction. HIV-1 is often acquired in the presence of pre-existing co-infections, such as Herpes Simplex Virus 2 (HSV-2). We examined the impact of HSV-2 status at the time of HIV-1 acquisition for its impact on subsequent clinical course, and total CD4+ T cell phenotypes. Methods. We assessed the relationship of HSV-1/HSV-2 co-infection status on CD4+ T cell counts and HIV-1 RNA levels over time prior in a cohort of 186 treatment naive adults identified during early HIV-1 infection. We assessed the activation and differentiation state of total CD4+ T cells at study entry by HSV-2 status. Results. of 186 recently HIV-1 infected persons, 101 (54%) were sero-positive for HSV-2. There was no difference in initial CD8+ T cell count, or differences between the groups for age, gender, or race based on HSV-2 status. Persons with HIV-1/HSV-2 co-infection sustained higher CD4+ T cell counts over time (+69 cells/ul greater (SD = 33.7, p = 0.04) than those with HIV-1 infection alone (Figure 1), after adjustment for HIV-1 RNA levels (-57 cells per 1 log(10) higher HIV-1 RNA, p<0.0001). We did not observe a relationship between HSV-2 infection status with plasma HIV-1 RNA levels over time. HSV-2 acquistion after HIV-1 acquisition had no impact on CD4+ count or viral load. We did not detect differences in CD4+ T cell activation or differentiation state by HSV-2+ status. Discussion. We observed no effect of HSV-2 status on viral load. However, we did observe that treatment naive, recently HIV-1 infected adults co-infected with HSV-2+ at the time of HIV-1 acquisition had higher CD4+ T cell counts over time. If verified in other cohorts, this result poses a striking paradox, and its public health implications are not immediately clear.Brazilian Program for STD and AIDS, Ministry of HealthSão Paulo City Health DepartmentFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)NIAID/NIHJohn E. Fogarty International CenterAIDS Research Institute of the AIDS Biology Program at UCSFCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Brazilian Ministry of EducationUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilUniv Calif San Francisco, San Francisco Gen Hosp, Div HIV AIDS, San Francisco, CA USAUniv Calif San Francisco, Dept Expt Med, San Francisco, CA USASao Paula City Hlth Syst, São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilBrazilian Program for STD and AIDS, Ministry of Health: 914/BRA/3014 UNESCO/KallasSão Paulo City Health Department: 2004-0.168.922-7/KallasFAPESP: 04/15856-9/KallasNIAID/NIH: AI066917/BarbourNIAID/NIH: AI064520/NixonJohn E. Fogarty International Center: D43 TW00003Web of Scienc

    An Instrument For Investigation of the Cosmic Microwave Background Radiation at Intermediate Angular Scales

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    We describe an off-axis microwave telescope for observations of the anisotropy in the cosmic microwave background (CMB) radiation on angular scales between 0.5 deg and 3 deg. The receiver utilizes cryogenic high-electron-mobility transistor (HEMT) amplifiers and detects the total power in multiple 3 GHz wide channels. Both frequency and polarization information are recorded allowing discrimination between CMB radiation and potential foreground sources and allowing checks for systematic effects. The instrumental radiometric offset is small (~1 mK). Data are taken by rapidly sampling while sweeping the beam many beamwidths across the sky. After detection, a spatio-temporal filter is formed in software which optimizes the sensitivity in a multipole band in the presence of atmospheric fluctuations. Observations were made from Saskatoon, Saskatchewan (SK), Canada during the winter of 1993 with six channels between 27.6 and 34.0 GHz, in 1994 with twelve channels between 27.6 and 44.1 GHz, and in 1995 with six channels between 38.2 and 44.1 GHz. The performance of the instrument and assessment of the atmospheric noise at this site are discussed.Comment: latex file is called inst.tex. 30 pages with 14 Postscript figures. Uses aas2pp4.sty (included). Submitted to Ap

    Food processing and technology 1978: a summary of research

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    Evaluation of tomato cultivars for processing / W. A. Gould, W. Stone, J. Mount, L. Witt, Y. Yamada, and S. Z. Berry -- Geotrichum candidum in midwestern tomato processing plants and various methods of inhibiting its growth / James G. Fox and Wilbur A. Gould -- Effects of various qualities of raw tomatoes (subjective evaluation) on color of extractable juice (objective evaluation) / Yasunori Yamada and Wilbur A. Gould -- Protein content of seeds taken from tomatoes at various stages of ripeness / Daniel Brodowski and J. R. Geisman -- Effects of cultivar, break temperature, and extraction methods on the viscosity of tomato juice / Hashmy Bel-Haj and Wilbur A. Gould -- A study of some factors affecting the solid content of canned tomatoes / J. R. Mount and W. A. Gould -- Prediction of ascorbic acid stability in canned apple juice / Mohamed I. Mahmoud and Wilbur A. Gould -- Investigation of protein content of ohio grown soybeans / Girish N. Desai and Andrew C. Peng -- Recovery and functionality of soybean leaf proteins / Mohammed H. Ali and Andrew C. Peng -- Carotene content of green snap beans / H. Fenercioglu and D. E. Crean -- Effect of reconditioning on the ascorbic acid content of potato cultivars / I. S. Arkoudilos and D. E. Crean -- Kinetic studies of polyphenol oxidase from HiDri cabbage / Ling-May Chen and Andrew C. Peng -- Refinements in pickle brine recycling / T. Glares and J. R. Geisman -- Use of ultraviolet light to inhibit Staphylococcus aureus growth on the surface of baked pumpkin pie / Nicholas N. Kallas and Wilbur A. Gould -- Development of a nutritionally improved corn masa / Thomas H. Rieman and Wilbur A. Gould -- Mechanical deboning of Lake Erie freshwater drum / W. E. Stone and W. A. Gould -- Lake Erie freshwater drum fillet processing, storage, and evaluation / W. E. Stone and W. A. Goul

    HTLV-1 Tax Specific CD8+ T Cells Express Low Levels of Tim-3 in HTLV-1 Infection: Implications for Progression to Neurological Complications

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    The T cell immunoglobulin mucin 3 (Tim-3) receptor is highly expressed on HIV-1-specific T cells, rendering them partially “exhausted” and unable to contribute to the effective immune mediated control of viral replication. To elucidate novel mechanisms contributing to the HTLV-1 neurological complex and its classic neurological presentation called HAM/TSP (HTLV-1 associated myelopathy/tropical spastic paraparesis), we investigated the expression of the Tim-3 receptor on CD8+ T cells from a cohort of HTLV-1 seropositive asymptomatic and symptomatic patients. Patients diagnosed with HAM/TSP down-regulated Tim-3 expression on both CD8+ and CD4+ T cells compared to asymptomatic patients and HTLV-1 seronegative controls. HTLV-1 Tax-specific, HLA-A*02 restricted CD8+ T cells among HAM/TSP individuals expressed markedly lower levels of Tim-3. We observed Tax expressing cells in both Tim-3+ and Tim-3− fractions. Taken together, these data indicate that there is a systematic downregulation of Tim-3 levels on T cells in HTLV-1 infection, sustaining a profoundly highly active population of potentially pathogenic T cells that may allow for the development of HTLV-1 complications

    Detection of Extended VHE Gamma Ray Emission from G106.3+2.7 with VERITAS

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    We report the detection of very-high-energy (VHE) gamma-ray emission from supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission overlapping the elongated radio SNR. The 7.3 sigma (pre-trials) detection has a full angular extent of roughly 0.6deg by 0.4deg. Most notably, the centroid of the VHE emission is centered near the peak of the coincident 12CO (J = 1-0) emission, 0.4deg away from the pulsar PSR J2229+6114, situated at the northern end of the SNR. Evidently the current-epoch particles from the pulsar wind nebula are not participating in the gamma-ray production. The VHE energy spectrum measured with VERITAS is well characterized by a power law dN/dE = N_0(E/3 TeV)^{-G} with a differential index of G = 2.29 +/- 0.33stat +/- 0.30sys and a flux of N_0 = (1.15 +/- 0.27stat +/- 0.35sys)x 10^{-13} cm^{-2} s^{-1} TeV^{-1}. The integral flux above 1 TeV corresponds to ~5 percent of the steady Crab Nebula emission above the same energy. We describe the observations and analysis of the object and briefly discuss the implications of the detection in a multiwavelength context.Comment: 5 pages, 2 figure
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