bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viremia and Nasal and Rectal Shedding of Rotavirus in Gnotobiotic Pigs Inoculated with Wa Human Rotavirus
Authors: Azevedo M. S. , Yuan L. , Jeong K.-I. , Gonzalez A. , Nguyen T. V. , Pouly S. , Gochnauer M. , Zhang W. , Azevedo A. , Saif L. J. 
Published: April 2005

ABSTRACT

Respiratory symptoms with rotavirus shedding in nasopharyngeal secretions have been reported in children with and without gastrointestinal symptoms (Zheng et al., 1991, J. Med. Virol.
34:
29-37). To investigate if attenuated and virulent human rotavirus (HRV) strains cause upper respiratory tract infections or viremia in gnotobiotic pigs, we inoculated them with attenuated or virulent HRV intranasally, intravenously, or orally or via feeding tube (gavage) and assayed virus shedding. After oral or intranasal inoculation with attenuated HRV, the pigs remained asymptomatic, but 79 to 95% shed virus nasally and 5 to 17% shed virus rectally. After inoculation by gavage, no pigs shed virus nasally or rectally, but all pigs seroconverted with antibodies to HRV. No viremia was detected through postinoculation day 10. Controls inoculated intranasally with nonreplicating rotavirus-like particles or mock inoculated did not shed virus. In contrast, 100% of pigs inoculated with virulent HRV (oral, intranasal, or gavage) developed diarrhea, shed virus nasally and rectally, and had viremia. The infectivity of sera from the viremic virulent HRV-inoculated pigs was confirmed by inoculating gnotobiotic pigs orally with pooled HRV-positive serum. Serum-inoculated pigs developed diarrhea and fecal and nasal virus shedding and seroconverted with serum and intestinal HRV antibodies. Pigs inoculated intravenously with serum or intestinal contents from the viremic virulent HRV-inoculated pigs developed diarrhea, virus shedding, and viremia, similar to the orally inoculated pigs. This study provides new evidence that virulent HRV causes transient viremia and upper respiratory tract infection in addition to gastrointestinal infection in gnotobiotic pigs, confirming previous reports of rotavirus antigenemia (Blutt et al., Lancet
362:
1445-1449, 2003). Our data also suggest that intestinal infection might be initiated from the basolateral side of the epithelial cells via viremia. Additionally, virus shedding patterns indicate a different pathogenesis for attenuated versus virulent HRV.
Characterization of Prototype Foamy Virus Gag Late Assembly Domain Motifs and Their Role in Particle Egress and Infectivity
Authors: Stange Annett , Mannigel Ingrid , Peters Katrin , Heinkelein Martin , Stanke Nicole , Cartellieri Marc , Göttlinger Heinrich , Rethwilm Axel , Zentgraf Hanswalter , Lindemann Dirk 
Published: April 2005

ABSTRACT
Foamy viruses (FV) are unusual among retroviruses since they require both Gag and Env structural proteins for particle egress. Recently significant progress has been made towards the mechanistic understanding of the viral release process, in particular that of retroviruses, and the viral domains and cellular pathways involved. However little is currently known about domains of FV structural proteins and cellular proteins engaged in this process. By mutational analysis of sequence motifs in prototype FV (PFV) Gag, bearing homology to known late assembly (L) domains, a PSAP motif with L domain function that was functionally interchangeable by heterologous L domains was identified. In contrast the inactivation of a PPPI motif had no significant influence on PFV particle release, although mutant viral particles displayed reduced infectivity. Similarly mutation of an evolutionary conserved YXXL motif revealed no classical L-domain function but resulted in release of noninfectious viruslike particles. Biochemical and electron microscopy analysis demonstrated that these mutant particles incorporated all viral structural proteins but contained aberrantly capsid structures, suggesting a role in capsid assembly for this PFV Gag sequence motif. In line with the mutational analysis, overexpression of dominant negative (DN) mutants and wild-type TSG101 but not the DN mutant of AIP-1/ALIX reduced PFV particle release and infectivity. Furthermore, DN mutants of Vps4A, Vps4B, and CHMP3 inhibited PFV egress and infectivity. Taken together these results demonstrate that PFV, like other viruses, requires components of the vacuolar protein sorting (VPS) machinery for egress and enters the VPS pathway through interaction with TSG101.
Pseudovirion Particle Production by Live Poxvirus Human Immunodeficiency Virus Vaccine Vector Enhances Humoral and Cellular Immune Responses
Authors: Chen Xuemin , Rock Michael T. , Hammonds Jason , Tartaglia James , Shintani Ayumi , Currier Jeff , Slike Bonnie , Crowe James E. , Marovich Mary , Spearman Paul 
Published: April 2005

ABSTRACTLive-vector-based human immunodeficiency virus (HIV) vaccines are an integral part of a number of HIV vaccine regimens currently under evaluation. Live vectors that carry an intactgaggene are capable of eliciting HIV pseudovirion particle formation from infected host cells. The impact of pseudovirion particle formation on the immune response generated by live HIV vaccine vectors has not been established. In this study, a canarypox HIV vaccine candidate vector expressing HIVgagandenvgenes, vCP205, was modified by the introduction of a glycine-to-alanine coding change in the N-terminal myristylation site ofgagto create Myr−vCP205. This substitution effectively eliminated particle formation without altering the level of protein production. vCP205 and Myr−vCP205 were then directly compared for the ability to induce HIV-specific immune responses in mice. The particle-competent vector vCP205 elicited higher levels of CD8+T-cell responses, as indicated by gamma interferon enzyme-linked immunospot (ELISPOT) assay and intracellular cytokine staining. Humoral responses to Gag and Env were also markedly higher from animals immunized with the particle-competent vector. Furthermore, HIV-specific CD4+T-cell responses were greater among animals immunized with the particle-competent vector. Using a human dendritic cell model of antigen presentation in vitro, vCP205 generated greater ELISPOT responses than Myr−vCP205. These results demonstrate that pseudovirion particle production by live-vector HIV vaccines enhances HIV-specific cellular and humoral immune responses.
An Unrelated Monoclonal Antibody Neutralizes Human Immunodeficiency Virus Type 1 by Binding to an Artificial Epitope Engineered in a Functionally Neutral Region of the Viral Envelope Glycoproteins
Authors: Ren Xinping , Sodroski Joseph , Yang Xinzhen 
Published: April 2005

ABSTRACT
Neutralizing antibodies often recognize regions of viral envelope glycoproteins that play a role in receptor binding or other aspects of virus entry. To address whether this is a necessary feature of a neutralizing antibody, we identified the V4 region of the gp120 envelope glycoprotein of human immunodeficiency virus type 1 (HIV-1) as a sequence that is tolerant of drastic change and thus appears to play a negligible role in envelope glycoprotein function. An artificial epitope tag was inserted into the V4 region without a significant effect on virus entry or neutralization by antibodies that recognize HIV-1 envelope glycoprotein sequences. An antibody directed against the artificial epitope tag was able to neutralize the modified, but not the wild-type, HIV-1. Thus, the specific target of a neutralizing antibody need not contribute functionally to the process of virus entry.
Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8 Replication and Transcription Activator Regulates Viral and Cellular Genes via Interferon-Stimulated Response Elements
Authors: Zhang Jun , Wang Jinzhong , Wood Charles , Xu Dongsheng , Zhang Luwen 
Published: April 2005

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (also called human herpesvirus 8 [HHV-8]) replication and transcription activator (RTA) is apparently necessary and sufficient for the switch from viral latency to lytic replication. RTA may regulate open reading frame (ORF) K14 (viral OX-2 homologue) and ORF74 (viral G-protein-coupled receptor homologue) genes through an interferon-stimulated response element (ISRE)-like sequence (K14 ISRE) in the promoter region. RTA strongly activated a K14 ISRE-containing K14-ORF74 promoter reporter construct and a heterologous promoter reporter construct containing K14 ISRE. RTA could bind to K14 ISRE and other ISREs, activate promoter reporter constructs from interferon-simulated genes (ISGs), and selectively induce three endogenous ISGs in primary endothelial cells: ISG-54, myxovirus resistance protein 1 (MxA), and stimulated
trans
-acting factor of 50 kDa. In addition, a region in the RTA DNA-binding domain has been identified with certain sequence similarity to the DNA-binding domains of the interferon regulatory factor (IRF) family. Mutation in one conserved amino acid within this region reduced the ability of RTA to bind to ISRE as well as other RTA response elements. Furthermore, the mutant failed to activate RTA-responsive promoters and to induce viral lytic gene expression. The mutation at the same conserved amino acid residue in IRF-7 drastically reduced its ability to bind to DNA and to activate the beta interferon promoter. The sequence and functional similarities between RTA and IRFs suggest that the HHV-8 RTA may usurp the cellular IRF pathway.
Evolution of the Equine Infectious Anemia Virus Long Terminal Repeat during the Alteration of Cell Tropism
Authors: Maury Wendy , Thompson Robert J. , Jones Quentin , Bradley Sarahann , Denke Tara , Baccam Prasith , Smazik Matthew , Oaks J. Lindsay 
Published: April 2005

ABSTRACT

Equine infectious anemia virus (EIAV) is a lentivirus with in vivo cell tropism primarily for tissue macrophages; however, in vitro the virus can be adapted to fibroblasts and other cell types. Tropism adaptation is associated with both envelope and long terminal repeat (LTR) changes, and findings strongly suggest that these regions of the genome influence cell tropism and virulence. Furthermore, high levels of genetic variation have been well documented in both of these genomic regions. However, specific EIAV nucleotide or amino acid changes that are responsible for cell tropism changes have not been identified. A study was undertaken with the highly virulent, macrophage-tropic strain of virus EIAV
wyo
to identify LTR changes associated with alterations in cell tropism. We found the stepwise generation of a new transcription factor binding motif within the enhancer that was associated with adaptation of EIAV to endothelial cells and fibroblasts. An LTR that contained the new motif had enhanced transcriptional activity in fibroblasts, whereas the new site did not alter LTR activity in a macrophage cell line. This finding supports a previous prediction that selection for new LTR genetic variants may be a consequence of cell-specific selective pressures. Additional investigations of the EIAV
wyo
LTR were performed in vivo to determine if LTR evolution could be detected over the course of a 3-year infection. Consistent with previous in vivo findings, we observed no changes in the enhancer region of the LTR over that time period, indicating that the EIAV
wyo
LTR was evolutionarily stable in vivo.
T-Cell Growth Transformation by Herpesvirus Saimiri Is Independent of STAT3 Activation
Authors: Heck Elke , Lengenfelder Doris , Schmidt Monika , Müller-Fleckenstein Ingrid , Fleckenstein Bernhard , Biesinger Brigitte , Ensser Armin 
Published: April 2005

ABSTRACTHerpesvirus saimiri (saimirine herpesvirus 2) (HVS), a T-lymphotropic tumor virus, induces lymphoproliferative disease in several species of New World primates. In addition, strains of HVS subgroup C are able to transform T cells of Old World primates, including humans, to permanently growing T-cell lines. In concert with the Stp oncoprotein, the tyrosine kinase-interacting protein (Tip) of HVS C488 is required for T-cell transformation in vitro and lymphoma induction in vivo. Tip was previously shown to interact with the protein tyrosine kinase Lck. Constitutive activation of signal transducers and activators of transcription (STATs) has been associated with oncogenesis and has also been detected in HVS-transformed T-cell lines. Furthermore, Tip contains a putative consensus YXPQ binding motif for the SH2 (srchomology 2) domains of STAT1 and STAT3. Tip tyrosine phosphorylation at this site was required for binding of STATs and induction of STAT-dependent transcription. Here we sought to address the relevance of STAT activation for transformation of human T cells by introducing a tyrosine-to-phenylalanine mutation in the YXPQ motif of Tip of HVS C488. Unexpectedly, the recombinant virus was still able to transform human T lymphocytes, but it had lost its capability to activate STAT3 as well as STAT1. This demonstrates that growth transformation by HVS is independent of STAT3 activation.
Rapid Viral Escape at an Immunodominant Simian-Human Immunodeficiency Virus Cytotoxic T-Lymphocyte Epitope Exacts a Dramatic Fitness Cost
Authors: Fernandez Caroline S. , Stratov Ivan , De Rose Robert , Walsh Katrina , Dale C. Jane , Smith Miranda Z. , Agy Michael B. , Hu Shiu-lok , Krebs Kendall , Watkins David I. , O'Connor David H. , Davenport Miles P. , Kent Stephen J. 
Published: April 2005

ABSTRACT

Escape from specific T-cell responses contributes to the progression of human immunodeficiency virus type 1 (HIV-1) infection. T-cell escape viral variants are retained following HIV-1 transmission between major histocompatibility complex (MHC)-matched individuals. However, reversion to wild type can occur following transmission to MHC-mismatched hosts in the absence of cytotoxic T-lymphocyte (CTL) pressure, due to the reduced fitness of the escape mutant virus. We estimated both the strength of immune selection and the fitness cost of escape variants by studying the rates of T-cell escape and reversion in pigtail macaques. Near-complete replacement of wild-type with T-cell escape viral variants at an immunodominant simian immunodeficiency virus Gag epitope KP9 occurred rapidly (over 7 days) following infection of pigtail macaques with SHIV
SF162P3
. Another challenge virus, SHIV
mn229
, previously serially passaged through pigtail macaques, contained a KP9 escape mutation in 40/44 clones sequenced from the challenge stock. When six KP9-responding animals were infected with this virus, the escape mutation was maintained. By contrast, in animals not responding to KP9, rapid reversion of the K165R mutation occurred over 2 weeks after infection. The rapidity of reversion to the wild-type sequence suggests a significant fitness cost of the T-cell escape mutant. Quantifying both the selection pressure exerted by CTL and the fitness costs of escape mutation has important implications for the development of CTL-based vaccine strategies.
Tumorigenic Poxviruses Up-Regulate Intracellular Superoxide To Inhibit Apoptosis and Promote Cell Proliferation
Authors: Teoh Melissa L. T. , Turner Patricia V. , Evans David H. 
Published: April 2005

ABSTRACT
Tumorigenic leporipoxviruses encode catalytically inactive homologs of cellular Cu-Zn superoxide dismutase (SOD1). The function of the orthologous myxoma virus M131R and Shope fibroma virus S131R gene products is uncertain, but they inhibit SOD1 activity by a process linked to binding its copper chaperone. Using a superoxide-sensitive dye (hydroethidine), we observed that virus infection increased intracellular superoxide levels in an M/S131R-dependent manner. To see whether this effect promotes infection, we deleted the Shope fibroma virus S131R gene and compared the clinical manifestations of wild-type and mutant virus infections in rabbits. S131RΔ virus produced significantly smaller fibroxanthosarcoma-like growths in vivo and, at a point where these growths were already receding, wild-type infections still showed extensive leukocyte infiltration, necrosis, and fibromatous cell proliferation. Coincidentally, whereas Jurkat cells are protected from mitochondria- and Fas-mediated apoptosis by wild-type myxoma virus in vitro, M131RΔ virus could not block Fas-initiated apoptosis as judged by DNA laddering, terminal deoxynucleotidyltransferase-mediated dUTP-fluorescein nick end labeling, and caspase 3 cleavage assays. These data suggest that tumorigenic poxviruses can modulate intracellular redox status to their advantage to stimulate infected cell growth and inhibit programmed cell death.
Global Biomass Variation and Its Geodynamic Effects: 1982–98
Authors: Rodell M. , Chao B. F. , Au A. Y. , Kimball J. S. , McDonald K. C. 
Published: April 2005

Abstract
Redistribution of mass near Earth’s surface alters its rotation, gravity field, and geocenter location. Advanced techniques for measuring these geodetic variations now exist, but the ability to attribute the observed modes to individual Earth system processes has been hampered by a shortage of reliable global data on such processes, especially hydrospheric processes. To address one aspect of this deficiency, 17 yr of monthly, global maps of vegetation biomass were produced by applying field-based relationships to satellite-derived vegetation type and leaf area index. The seasonal variability of biomass was estimated to be as large as 5 kg m−2. Of this amount, approximately 4 kg m−2 is due to vegetation water storage variations. The time series of maps was used to compute geodetic anomalies, which were then compared with existing geodetic observations as well as the estimated measurement sensitivity of the Gravity Recovery and Climate Experiment (GRACE). For gravity, the seasonal amplitude of biomass variations may be just within GRACE’s limits of detectability, but it is still an order of magnitude smaller than current observation uncertainty using the satellite-laser-ranging technique. The contribution of total biomass variations to seasonal polar motion amplitude is detectable in today’s measurement, but it is obscured by contributions from various other sources, some of which are two orders of magnitude larger. The influence on the length of day is below current limits of detectability. Although the nonseasonal geodynamic signals show clear interannual variability, they are too small to be detected.
Indian Monsoon Onset and the Americas Midsummer Drought: Out-of-Equilibrium Responses to Smooth Seasonal Forcing
Authors: Mapes Brian E. , Liu Ping , Buenning Nikolaus 
Published: April 2005

Abstract
Two dominant high-frequency features of Northern Hemisphere summer climatology are examined in an atmosphere–land general circulation model (AGCM): the sudden onset of rains in south Asia, and the midsummer rainfall minimum in the tropical Americas. A control simulation succeeds in capturing these observed features fairly well. A slowed-calendar experiment is performed, to see whether these features are close to equilibrium with seasonally evolving forcings (orbital geometry and SST). The results indicate that some lag (disequilbrium) within the AGCM delays south Asian onset by about a month, from May in the experiment when seasonal forcing evolves extremely slowly to June in the normal, full-speed seasonal cycle. Disequilibrium also acts to delay and limit the amplitude of the Americas midsummer drought, and the associated intrusion of the Atlantic subtropical high into the Intra-Americas Seas’ region. It is hypothesized that early summer (centered on the solstice) temperature over mid- and high-latitude continents, which differs greatly between experiment and control, drives the low-latitude rainfall differences. A more mysterious pole-to-pole, annual-mean, zonal wave-1 difference is also found in the slowed-calendar experiment.
New Vibrio cholerae O1 Biotype ElTor bacteriophages
Authors: Sen Anindito , Ghosh Amar N 
Published: April 2005

AbstractWe report the presence of three new O1 ElTor vibriophages named AS1, AS2 and AS3, isolated from the sewage and pond waters of the outskirts of Kolkata. A few phages, named AS4, with hexagonal heads and abnormally long tails with typical curly projections were also found in the water samples.
Is obesity a risk factor for low back pain? An example of using the evidence to answer a clinical question
Authors: Mirtz Timothy A , Greene Leon 
Published: April 2005

Abstract

Background

Obesity as a causal factor for low back pain has been controversial with no definitive answer to this date. The objective of this study was to determine whether obesity is associated with low back pain. In addition this paper aims to provide a step-by-step guide for chiropractors and osteopaths on how to ask and answer a clinical question using the literature.

Methods

A literature review using the MEDLINE search engine using the keywords "obesity", "low back pain", "body mass index" "BMI" and "osteoarthritis" from years 1990 to 2004 was utilised. The method employed is similar to that utilised by evidence-based practice advocates.

Results

The available data at this time is controversial with no clear-cut evidence connecting low back pain with obesity.

Conclusion

There is a lack of a clear dose-response relationship between body mass index (BMI) and low back pain. Further, studies on the relationship between obesity and related lumbar osteoarthritis, knee pain, and disc herniation are also problematic.There is little doubt that future studies with controlled variables are needed to determine the existence of an unambiguous link, if any.
Fertility Preservation in Breast Cancer Patients: A Prospective Controlled Comparison of Ovarian Stimulation With Tamoxifen and Letrozole for Embryo Cryopreservation
Authors: Oktay Kutluk , Buyuk Erkan , Libertella Natalie , Akar Munire , Rosenwaks Zev 
Published: April 2005

Purpose To develop safe ovarian stimulation methods to perform in vitro fertilization (IVF) in breast cancer patients who wish to preserve their fertility via embryo cryopreservation before chemotherapy. Patients and Methods Sixty women (age range, 24 to 43 years) with breast cancer were prospectively studied. Twenty-nine patients underwent 33 ovarian stimulation cycles with either tamoxifen 60 mg/d alone (Tam-IVF) or in combination with low-dose follicle-stimulating hormone (TamFSH-IVF) or letrozole 5 mg in combination with FSH (Letrozole-IVF). After IVF, all resultant embryos were cryopreserved to preserve fertility. Recurrence rates were compared with controls (n = 31) who elected not to undergo IVF. Results Compared with Tam-IVF, both TamFSH-IVF and Letrozole-IVF patients had greater numbers of follicles (2 ± 0.3 v 6 ± 1 and 7.8 ± 0.9, respectively; P < .0001), mature oocytes (1.5 ± 0.3 v 5.1 ± 1.1 and 8.5 ± 1.6, respectively; P < .001), and embryos (1.3 ± 0.2 v 3.8 ± 0.8 and 5.3 ± 0.8, respectively; P < .001). Peak estradiol (E2) levels were lower with Letrozole-IVF and Tam-IVF compared with TamFSH-IVF. After 554 ± 31 days (range, 153 to 1,441 days) of follow-up, cancer recurrence rate was similar between IVF and control patients (three of 29 v three of 31 patients, respectively; hazard ratio, 1.5; 95% CI, 0.29 to 7.4), and this estimate was not affected by cancer stage. Conclusion The combination of low-dose FSH with tamoxifen (TamFSH-IVF) or letrozole (Letrozole-IVF) results in higher embryo yield compared with Tam-IVF. Recurrence rates do not seem to be increased, but the letrozole protocol may be preferred because it results in lower peak E2 levels.
Flachheit: Eine nützliche Eigenschaft auch für Systeme mit Totzeiten (Flatness: A Useful Property also for Systems with Delays)
Authors: Rudolph Joachim 
Published: April 2005

Abstract
Die Trajektorienplanung sowie die Steuerung und die Folgeregelung nichtlinearer Systeme werden durch die Flachheitseigenschaft wesentlich vereinfacht. Davon zeugen zahlreiche Anwendungen im universitären wie im industriellen Bereich. Das Flachheitskonzept kann auf nichtlineare Totzeitsysteme und verteilte Systeme mit konzentrierten Stelleingriffen ausgedehnt werden. Anhand von Modellen chemischer Reaktoren wird beispielhaft in die flachheitsbasierten Methoden zur Systemanalyse, zur Trajektorienplanung und zum Reglerentwurf für nichtlineare Totzeitsysteme eingeführt.