bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mineralogy of fine‐grained material in the Krymka (LL3.1) chondrite
Authors: SEMENENKO V. P. , BISCHOFF A. , WEBER I. , PERRON C. , GIRICH A. L. 
Published: February 2010

Abstract— Two dark lithic fragments and matrix of the Krymka LL3.1 chondrite were mineralogically and chemically studied in detail. These objects are characterised by the following chemical and mineralogical characteristics, which distinguish them from the host chondrite Krymka: (1) bulk chemical analyses revealed low totals (systematically lower than 94 wt%) due to high porosity; (2) enrichment in FeO and depletion in S, MgO and SiO2 due to a high abundance of Fe‐rich silicates and low sulfide abundance; (3) fine‐grained, almost chondrule‐free texture with predominance of a porous, cryptocrystalline groundmass and fine grains; (4) occurrence of a small amount of once‐molten material (microchondrules) enclosed in fine‐grained materials; (5) occurrence of accretionary features, especially unique accretionary spherules; (6) high abundance of small calcium‐ aluminium‐rich inclusions (CAIs) in one of the fine‐grained fragments. It is suggested that the abundance of CAIs in this fragment is one of the highest ever found in an ordinary chondrite.Accretionary, fine‐grained spherules within one of the fragments bear fundamental information about the initial stages of accretion as well as on the evolution of the clast, its incorporation, and history within the bulk rock of Krymka. The differences in porosity, bulk composition, and mineralogy of cores and rims of the fine‐grained spherulitic objects allow us to speculate on the following processes: (1) Low velocity accretion of tiny silicate grains onto the surface of coarse metal or silicate grains in a dusty region of the nebula is the beginning of the formation of accretionary, porous (fluffy) silicate spherules. (2) Within a dusty environment with decreasing silicate/(metal + sulfide) ratio the porous spherules collected abundant metal and sulfide particles together with silicate dust, which formed an accretionary rim. Variations of the silicate/(sulfide + metal) ratio in the dusty nebular environment result in the formation of multi‐layered rims on the surface of the silicate‐rich spherules. (3) Soft accretion and lithification of rimmed, fluffy spherules, fine‐grained, silicate‐rich dust, metal‐sulfide particles, CAIs, silicate‐rich microchondrules, and coarse silicate grains and fragments followed. (4) After low‐temperature processing of the primary, accretionary rock collisional fragmentation occurred, the fragments were subsequently coated by fine‐grained material, which was highly oxidized and depleted in sulfides. (5) In a final stage this accretionary “dusty” rock was incorporated as a fragment within the Krymka host.
Comparative Measurement of Cell-Mediated Immune Responses of Swine to the M and N Proteins of Porcine Reproductive and Respiratory Syndrome Virus
Authors: Jeong Hyun-Jeong , Song Young-Jo , Lee Sang-Won , Lee Joong-Bok , Park Seung-Yong , Song Chang-Seon , Ha Gun-Woo , Oh Jin-Sik , Oh Youn-Kyoung , Choi In-Soo 
Published: February 2010

ABSTRACT

The principal objectives of this study were to develop autologous antigen-presenting cells (APCs) and to characterize the antigen-specific T-cell responses to the M and N proteins of porcine reproductive and respiratory syndrome virus (PRRSV) by using those APCs in outbred pigs. The
orf6
and
orf7
genes fused with porcine granulocyte-macrophage colony-stimulating factor (GM-CSF) were cloned into the mammalian expression vector to generate two plasmid DNAs, namely, pcDNA3.1-GM-CSF-PRRSV-M and pcDNA3.1-GM-CSF-PRRSV-N. Three of six pigs in two groups were repeatedly immunized with either plasmid DNA construct, and four pigs were used as controls. The recombinant M and N proteins fused with the protein transduction domain (PTD) of the human immunodeficiency virus type 1 transactivator of transcription protein were employed to generate major histocompatibility complex-matched autologous APCs from each pig. The levels of T-cell proliferation and gamma interferon (IFN-γ) synthesis were compared between pigs immunized with the two plasmid DNAs after stimulation of the peripheral blood mononuclear cells (PBMCs) of each pig with the autologous antigen-presenting dendritic cells and PBMCs. Higher levels of T-cell proliferation and IFN-γ synthesis were identified in PBMCs isolated from the pigs immunized with pcDNA3.1-GM-CSF-PRRSV-M than in those isolated from the pigs immunized with pcDNA3.1-GM-CSF-PRRSV-N. By way of contrast, serum antibodies were detected only in pigs immunized with pcDNA3.1-GM-CSF-PRRSV-N. However, no T-cell response or antibody production was detected in the control pigs. These results suggest that the M protein of PRRSV is a more potent T cell-stimulating antigen than the N protein. Nevertheless, it should be emphasized that the N protein substantially induces both cellular and humoral immune responses. The newly developed protocol for generating self APCs may prove effective in further efforts to characterize additional PRRSV proteins involved in the induction of cell-mediated immunity.
Low Prevalence Rate of Indeterminate Serological Human Immunodeficiency Virus Results among Pregnant Women from Burkina Faso, West Africa
Authors: Kania Dramane , Fao Paulin , Valéa Diane , Gouem Clarisse , Kagoné Thérèse , Hien Hervé , Somda Paulin , Ouédraogo Patrice , Drabo Aly , Gampini Sandrine , Méda Nicolas , Diagbouga Serge , Van de Perre Philippe , Rouet François 
Published: February 2010

ABSTRACT
Rapid human immunodeficiency virus (HIV) antibody tests have been adopted into national guidelines for HIV testing in many countries in sub-Saharan Africa. One goal of HIV rapid testing is to minimize the occurrence of indeterminate results. From January 2005 to December 2007, plasma (or serum) samples from pregnant women in Bobo-Dioulasso (Burkina Faso, West Africa) were screened for HIV by using two rapid tests (the Determine HIV1/2 test [Abbott] and Genie II HIV-1/HIV-2 [Bio-Rad]) through a sequential algorithm prior to enrollment of HIV-1-infected women in a prevention of mother-to-child transmission (PMTCT) trial (WHO/ANRS 1289 Kesho Bora trial). Samples exhibiting indeterminate results (Determine positive and Genie II negative) were further tested with a fourth-generation HIV enzyme immunoassay (EIA) (Murex HIV Ag/Ab combination in 2005 and 2006 and Vironostika HIV Uni-Form II Ag/Ab in 2007). If positive, they were finally assessed for HIV-1 RNA (Generic HIV-1 RNA viral load assay; Biocentric). From a total of 44,653 samples tested, 597 (1.3%) showed indeterminate results. Of these, 367 could be analyzed by EIA. Only 15 (15/367, 4.1%) samples were found EIA reactive. Of these, 11 could be tested for HIV-1 RNA. All were HIV-1 RNA negative. In our clinical practice, pregnant women with such indeterminate results are now reassured during posttest counseling that they are very unlikely to be infected with HIV-1. As a consequence, such women with indeterminate results can reliably be considered negative when urgent clinical decisions (such as providing PMTCT prophylaxis) need to be taken.
Outbreak of Febrile Respiratory Illness Associated with Adenovirus 11a Infection in a Singapore Military Training Camp
Authors: Kajon Adriana E. , Dickson Laura M. , Metzgar David , Houng Huo-Shu , Lee Vernon , Tan Boon-Huan 
Published: February 2010

ABSTRACT
Outbreak cases of acute respiratory disease (ARD) associated with subspecies B2 human adenovirus 11a (HAdV-11a) infection were detected during 2005 in a military basic training camp in Singapore. The Singapore HAdV-11a strain is highly similar to other Asian strains of HAdV-11, including strain QS-DLL, which is responsible for the recently described 2006 outbreak of ARD in China.
Novel Real-Time PCR Assay for Simultaneous Detection and Differentiation of
Clostridium chauvoei
and
Clostridium septicum
in Clostridial Myonecrosis
Authors: Halm Anna , Wagner Martin , Köfer Josef , Hein Ingeborg 
Published: February 2010

ABSTRACT

A real-time PCR assay based on the 16S rRNA gene sequence was designed for differentiation of blackleg-causing
Clostridium chauvoei
and
Clostridium septicum
, a phylogenetically closely related bacterium responsible for malignant edema. In order to exclude false-negative results, an internal amplification control was included in the assay. A set of three probes, one specific for
C. chauvoei
, one specific for
C. septicum
, and one specific for both species, permitted unequivocal detection of
C. chauvoei
in tests of 32
Clostridium
sp. strains and 10 non-
Clostridium
strains. The assay proved to be sensitive, detecting one genome of
C. chauvoei
or
C. septicum
per PCR and 1.79 × 10
3
C. chauvoei
cells/g artificially contaminated muscle tissue. In tests of 11 clinical specimens, the real-time PCR assay yielded the same results as an established conventional PCR method.
Detection of
Aspergillus fumigatus
in a Rat Model of Invasive Pulmonary Aspergillosis by Real-Time Nucleic Acid Sequence-Based Amplification
Authors: Zhao Yanan , Park Steven , Warn Peter , Shrief Raghdaa , Harrison Elizabeth , Perlin David S. 
Published: February 2010

ABSTRACT

Rapid and sensitive detection of
Aspergillus
from clinical samples may facilitate the early diagnosis of invasive pulmonary aspergillosis (IPA). A real-time nucleic acid sequence-based amplification (NASBA) method was investigated by use of an inhalational rat model of IPA. Immunosuppressed male Sprague-Dawley rats were exposed to
Aspergillus fumigatus
spores for an hour in an aerosol chamber. Bronchoalveolar lavage (BAL) fluid, lung tissues, and whole blood were collected from five infected rats at 1, 24, 48, 72, and 96 h postinfection and five uninfected rats at the end of the experiment. Total nucleic acid (TNA) was extracted on an easyMAG instrument. A primer-molecular beacon set targeting 28S rRNA was designed to detect
Aspergillus
spp. The results were compared to those of quantitative PCR (qPCR) (18S rDNA) and quantitative culture. The analytical sensitivity of the real-time NASBA assay was <1 CFU/assay. A linear range of detection was demonstrated over 5 log units of conidia (10 to 10
5
spores). Both NASBA and qPCR showed a progressive increase in lung tissue burdens, while the CFU counts were stable over time. The fungal burdens in BAL fluid were more variable and not indicative of a progressive infection. The results of both real-time assays correlated well for both sample types (
r
= 0.869 and
P
< 0.0001 for lung tissue,
r
= 0.887 and
P
< 0.0001 for BAL fluid). For all whole-blood specimens, NASBA identified
Aspergillus
-positive samples in the group from which samples were collected at 72 h postinfection (three of five samples) and the group from which samples were collected at 96 h postinfection (five of five samples), but no positive results were obtained by culture or PCR. Real-time NASBA is highly sensitive and useful for the detection of
Aspergillus
in an experimental model of IPA.
Rapid Identification and Differentiation of
Mycobacterium avium
Subspecies
paratuberculosis
Types by Use of Real-Time PCR and High-Resolution Melt Analysis of the MAP1506 Locus
Authors: Castellanos Elena , Aranaz Alicia , De Buck Jeroen 
Published: February 2010

ABSTRACT

High-resolution melt (HRM) analysis can identify sequence polymorphisms by comparing the melting curves of amplicons generated by real-time PCR amplification. We describe the application of this technique to identify
Mycobacterium avium
subspecies
paratuberculosis
types I, II, and III. The HRM approach was based on type-specific nucleotide sequences in MAP1506, a member of the PPE (proline-proline-glutamic acid) gene family.
Impact of Varicella-Zoster Virus on Dendritic Cell Subsets in Human Skin during Natural Infection
Authors: Huch Jennifer H. , Cunningham Anthony L. , Arvin Ann M. , Nasr Najla , Santegoets Saskia J. A. M. , Slobedman Eric , Slobedman Barry , Abendroth Allison 
Published: February 2010

ABSTRACTVaricella-zoster virus (VZV) causes varicella and herpes zoster, diseases characterized by distinct cutaneous rashes. Dendritic cells (DC) are essential for inducing antiviral immune responses; however, the contribution of DC subsets to immune control during natural cutaneous VZV infection has not been investigated. Immunostaining showed that compared to normal skin, the proportion of cells expressing DC-SIGN (a dermal DC marker) or DC-LAMP and CD83 (mature DC markers) were not significantly altered in infected skin. In contrast, the frequency of Langerhans cells was significantly decreased in VZV-infected skin, whereas there was an influx of plasmacytoid DC, a potent secretor of type I interferon (IFN). Langerhans cells and plasmacytoid DC in infected skin were closely associated with VZV antigen-positive cells, and some Langerhans cells and plasmacytoid DC were VZV antigen positive. To extend thesein vivoobservations, both plasmacytoid DC (PDC) isolated from human blood and Langerhans cells derived from MUTZ-3 cells were shown to be permissive to VZV infection. In VZV-infected PDC cultures, significant induction of alpha IFN (IFN-α) did not occur, indicating the VZV inhibits the capacity of PDC to induce expression of this host defense cytokine. This study defines changes in the response of DC which occur during cutaneous VZV infection and implicates infection of DC subtypes in VZV pathogenesis.
A Mouse Model of Lethal Infection for Evaluating Prophylactics and Therapeutics against Monkeypox Virus
Authors: Stabenow Jennifer , Buller R. Mark , Schriewer Jill , West Cheri , Sagartz John E. , Parker Scott 
Published: February 2010

ABSTRACT

Monkeypox virus (MPXV) is an orthopoxvirus closely related to variola, the etiological agent of smallpox. In humans, MPXV causes a disease similar to smallpox and is considered to be an emerging infectious disease. Moreover, the use of MPXV for bioterroristic/biowarfare activities is of significant concern. Available small animal models of human monkeypox have been restricted to mammals with poorly defined biologies that also have limited reagent availability. We have established a murine MPXV model utilizing the STAT1-deficient C57BL/6 mouse. Here we report that a relatively low-dose intranasal (IN) infection induces 100% mortality in the
stat1
−
/
−
model by day 10 postinfection with high infectious titers in the livers, spleens, and lungs of moribund animals. Vaccination with modified vaccinia virus Ankara (MVA) followed by a booster vaccination is sufficient to protect against an intranasal MPXV challenge and induces an immune response more robust than that of a single vaccination. Furthermore, antiviral treatment with CMX001 (HDP-cidofovir) and ST-246 protects when administered as a regimen initiated on the day of infection. Thus, the
stat1
−
/
−
model provides a lethal murine platform for evaluating therapeutics and for investigating the immunological and pathological responses to MPXV infection.
Interleukin 18 Coexpression during Respiratory Syncytial Virus Infection Results in Enhanced Disease Mediated by Natural Killer Cells
Authors: Harker James A. , Godlee Alexandra , Wahlsten Jennifer L. , Lee Debbie C. P. , Thorne Lucy G. , Sawant Devika , Tregoning John S. , Caspi Rachel R. , Bukreyev Alexander , Collins Peter L. , Openshaw Peter J. M. 
Published: February 2010

ABSTRACTRespiratory syncytial virus (RSV) causes bronchiolitis, the main cause of infantile hospitalization. Immunity against reinfection is poor, and there is great interest in boosting vaccine responses using live vectors expressing host cytokines. We therefore constructed a recombinant RSV expressing murine interleukin 18 (RSV/IL-18), a cytokine capable of inducing strong antiviral immune responses.In vitroRSV/IL-18 replicated at wild-type levels and produced soluble IL-18. In naïve BALB/c mice, RSV/IL-18 infection significantly increased both IL-18 mRNA and protein and attenuated the peak viral load 3-fold. Despite a reduced viral load, RSV/IL-18 infection caused a biphasic weight loss at days 2 and 6 postinfection that was not seen in wild-type infection. Day 2 disease was associated with enhanced pulmonary natural killer (NK) cell numbers and activity and was prevented by NK cell depletion during infection; day 6 disease was correlated with CD8 T-cell recruitment and was enhanced by NK cell depletion. IL-18 expression during priming also enhanced RSV-specific antibody responses and T-cell responses on secondary RSV infection. Therefore, while IL-18 boosted antiviral immunity and reduced the viral load, its coexpression worsened disease. This is the first recombinant RSV with this property, and these are the first studies to demonstrate that NK cells can induce pathology during pulmonary viral infections.
Antisense Transcription in Gammaretroviruses as a Mechanism of Insertional Activation of Host Genes
Authors: Rasmussen Mads Heilskov , Ballarín-González Borja , Liu Jinghua , Lassen Louise Berkhoudt , Füchtbauer Annette , Füchtbauer Ernst-Martin , Nielsen Anders Lade , Pedersen Finn Skou 
Published: February 2010

ABSTRACT

Transcription of retroviruses is initiated at the U3-R region boundary in the integrated provirus and continues unidirectionally to produce genomic and mRNA products of positive polarity. Several studies have recently demonstrated the existence of naturally occurring protein-encoding transcripts of negative polarity in complex retroviruses. We report here on the identification of transcripts of negative polarity in simple murine leukemia virus (MLV). In T-cell and B-cell lymphomas induced by SL3-3 and Akv MLV, antisense transcripts initiated in the U3 region of the proviral 5′ long terminal repeat (LTR) and continued into the cellular proto-oncogenes
Jdp2
and
Bach2
to create chimeric transcripts consisting of viral and host sequence. The phenomenon was validated
in vivo
using a knock-in mouse model homozygous for a single LTR at a position known to activate
Nras
in B-cell lymphomas. A 5′ rapid amplification of cDNA ends (RACE) analysis indicated a broad spectrum of initiation sites within the U3 region of the 5′ LTR. Our data show for the first time transcriptional activity of negative polarity initiating in the U3 region of simple retroviruses and suggest a novel mechanism of insertional activation of host genes. Elucidation of the nature and potential regulatory role of 5′ LTR antisense transcription will be relevant to the design of therapeutic vectors and may contribute to the increasing recognition of pervasive eukaryotic transcription.
Direct Evidence from Single-Cell Analysis that Human α-Defensins Block Adenovirus Uncoating To Neutralize Infection
Authors: Nguyen Emily K. , Nemerow Glen R. , Smith Jason G. 
Published: February 2010

ABSTRACT
Human α-defensins are evolutionarily conserved effectors of the innate immune response with broadly acting antibacterial activity. Their role in antiviral immunity is less well understood. We previously showed that these antimicrobial peptides are potent inhibitors of human adenovirus infection. Based on biochemical studies and indirect evidence from confocal microscopy, we proposed that defensins bind to and stabilize the virus capsid and neutralize infection by preventing the release of the endosomalytic protein VI. To determine whether defensin action also restricts exposure of the viral genome, we developed a system to evaluate adenovirus uncoating during cell entry by monitoring the exposure of BrdU-labeled viral genomes. This assay allowed us to determine the kinetics of uncoating of virus particles in single cells. Using this assay, we now provide direct evidence that human α-defensins block adenovirus infection by preventing uncoating during cell entry.
Role of the IE62 Consensus Binding Site in Transactivation by the Varicella-Zoster Virus IE62 Protein
Authors: White Kris , Peng Hua , Hay John , Ruyechan William T. 
Published: February 2010

ABSTRACT

The varicella-zoster virus (VZV) IE62 protein is the major transcriptional activator. IE62 is capable of associating with DNA both nonspecifically and in a sequence-specific manner via a consensus binding site (5′-ATCGT-3′). However, the function of the consensus site is poorly understood, since IE62 efficiently transactivates promoter elements lacking this sequence. In the work presented here, sequence analysis of the VZV genome revealed the presence of 245 IE62 consensus sites throughout the genome. Some 54 sites were found to be present within putative VZV promoters. Electrophoretic mobility shift assay (EMSA) experiments using an IE62 fragment containing the IE62 DNA-binding domain and duplex oligonucleotides that did or did not contain the IE62 consensus binding sequence yielded

K
D

(equilibrium dissociation constant) values in the nanomolar range. Further, the IE62 DNA binding domain was shown to have a 5-fold-increased affinity for its consensus site compared to nonconsensus sequences. The effect of consensus site presence and position on IE62-mediated activation of native VZV and model promoters was examined using site-specific mutagenesis and transfection and superinfection reporter assays. In all promoters examined, the consensus sequence functioned as a distance-dependent repressive element. Protein recruitment assays utilizing the VZV gI promoter indicated that the presence of the consensus site increased the recruitment of IE62 but not Sp1. These data suggest a model where the IE62 consensus site functions to down-modulate IE62 activation, and interaction of IE62 with this sequence may result in loss or decrease of the ability of IE62 to recruit cellular factors needed for full promoter activation.
The Pre-S2 Domain of the Hepatitis B Virus Is Dispensable for Infectivity but Serves a Spacer Function for L-Protein-Connected Virus Assembly
Authors: Ni Yi , Sonnabend Jessika , Seitz Stefan , Urban Stephan 
Published: February 2010

ABSTRACT

The envelope of the human hepatitis B virus (HBV) contains three membrane proteins (L, M, and S). They accomplish different functions in HBV infectivity and nucleocapsid envelopment. Infectivity determinants have been assigned to the N-terminal part of the pre-S1 domain of the L protein and the antigenic loop of the S domain in the L and/or S protein. Nucleocapsid envelopment requires a C-terminal sequence within pre-S1, including the five N-terminal amino acids of pre-S2 as part of the L protein. However, the role of the M protein and the pre-S2 domain of the L protein are not entirely understood. We addressed this question and analyzed assembly competence and infectivity of viruses that lack the M protein and, at the same time, carry alterations in the pre-S2 domain of L. These include deletions, in part frameshift mutations and a randomization of virtually the entire pre-S2 sequence. We found that the M protein is dispensable for HBV
in vitro
infectivity. Viruses that lack the M protein and contain a mostly randomized pre-S2 sequence assemble properly and are infectious in HepaRG cells and primary human hepatocytes. While deletions of 20 amino acids in the pre-S2 domain of L protein allowed the production of infectious virions, more extended deletions interfered with assembly. This indicates that the pre-S2 domain of the L protein serves an important role for virus assembly, presumably as a spacer that supports conformational changes of L protein but does not participate as part of the M protein or as a subdomain of the L protein in virus entry.