282 research outputs found
Lactate Dehydrogenase-Elevating Virus Induces Systemic Lymphocyte Activation via TLR7-Dependent IFNα Responses by Plasmacytoid Dendritic Cells
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
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
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
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
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 and 100 cm, 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
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
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
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
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
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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