bluuebunny/crossref_metadata_2025_split huggingface dataset:
RhoA-Derived Peptide Dimers Share Mechanistic Properties with Other Polyanionic Inhibitors of Respiratory Syncytial Virus (RSV), Including Disruption of Viral Attachment and Dependence on RSV G
Authors: Budge Philip J. , Li Yeqiang , Beeler Judy A. , Graham Barney S. 
Published: April 2004

ABSTRACTLarge polyanionic molecules, such as sulfated polysaccharides (including soluble heparin and dextran sulfate), synthetic polyanionic polymers, and negatively charged proteins, have been shown to broadly inhibit several enveloped viruses. We recently reported the antiviral activity of a peptide derived from amino acids 77 to 95 of a potential binding partner of respiratory syncytial virus F protein (RSV F), the GTPase RhoA. A subsequent study with a truncated peptide (amino acids 80 to 94) revealed that optimal antiviral activity required dimerization via intermolecular disulfide bonds. We report here that the net negative charge of this peptide is also a determining factor for its antiviral activity and that it, like other polyanions, inhibits virus attachment. In a flow cytometry-based binding assay, peptide 80-94, heparin, and dextran sulfate inhibited the attachment of virus to cells at 4°C at the same effective concentrations at which they prevent viral infectivity. Interestingly, time-of-addition experiments revealed that peptide 80-94 and soluble heparin were also able to inhibit the infectivity of a virus that had been prebound to cells at 4°C, as had previously been shown for dextran sulfate, suggesting a potential role for postattachment effects of polyanions on RSV entry. Neutralization experiments with recombinant viruses showed that the antiviral activities of peptide 80-94 and dextran sulfate were diminished in the absence of the RSV attachment glycoprotein (G). Taken together, these data indicate that the antiviral activity of RhoA-derived peptides is functionally similar to that of other polyanions, is dependent on RSV G, and does not specifically relate to a protein-protein interaction between F and RhoA.
Conserved Cysteine-Rich Domain of Paramyxovirus Simian Virus 5 V Protein Plays an Important Role in Blocking Apoptosis
Authors: Sun Minghao , Rothermel Terri A. , Shuman Laurie , Aligo Jason A. , Xu Shibo , Lin Yuan , Lamb Robert A. , He Biao 
Published: April 2004

ABSTRACT
The paramyxovirus family includes many well-known human and animal pathogens as well as emerging viruses such as Hendra virus and Nipah virus. The V protein of simian virus 5 (SV5), a prototype of the paramyxoviruses, contains a cysteine-rich C-terminal domain which is conserved among all paramyxovirus V proteins. The V protein can block both interferon (IFN) signaling by causing degradation of STAT1 and IFN production by blocking IRF-3 nuclear import. Previously, it was reported that recombinant SV5 lacking the C terminus of the V protein (rSV5VΔC) induces a severe cytopathic effect (CPE) in tissue culture whereas wild-type (wt) SV5 infection does not induce CPE. In this study, the nature of the CPE and the mechanism of the induction of CPE were investigated. Through the use of DNA fragmentation, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling, and propidium iodide staining assays, it was shown that rSV5VΔC induced apoptosis. Expression of wt V protein prevented apoptosis induced by rSV5VΔC, suggesting that the V protein has an antiapoptotic function. Interestingly, rSV5VΔC induced apoptosis in U3A cells (a STAT1-deficient cell line) and in the presence of neutralizing antibody against IFN, suggesting that the induction of apoptosis by rSV5VΔC was independent of IFN and IFN-signaling pathways. Apoptosis induced by rSV5VΔC was blocked by a general caspase inhibitor, Z-VAD-FMK, but not by specific inhibitors against caspases 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 13, suggesting that rSV5VΔC-induced apoptosis can occur in a caspase 12-dependent manner. Endoplasmic reticulum stress can lead to activation of caspase 12; compared to the results seen with mock and wt SV5 infection, rSV5VΔC infection induced ER stress, as demonstrated by increased expression levels of known ER stress indicators GRP 78, GRP 94, and GADD153. These data suggest that rSV5VΔC can trigger cell death by inducing ER stress.
Unspliced Rous Sarcoma Virus Genomic RNAs Are Translated and Subjected to Nonsense-Mediated mRNA Decay before Packaging
Authors: LeBlanc Jason J. , Beemon Karen L. 
Published: April 2004

ABSTRACT

Retroviruses package full-length, unspliced RNAs into progeny virions as dimerized RNA genomes. They also use unspliced RNAs as mRNAs to produce the
gag
and
pol
gene products. We asked whether a single Rous sarcoma virus (RSV) RNA can be translated and subsequently packaged or whether genomic packaging requires a nontranslated population of RNAs. We addressed this issue by utilizing the translation-dependent nonsense-mediated mRNA decay (NMD) pathway. NMD is the selective destruction of mRNAs bearing premature termination codons (PTCs). The pathway has been shown to be associated with splicing in higher eukaryotes. Here, we demonstrate that both translation and the cellular factor Upf1 are required for the decay of unspliced, PTC-bearing RSV RNA by the NMD pathway. To address the relationship between RNA translation and packaging, we examined virus produced in cells cotransfected with PTC-bearing retroviral clones and wild-type viral clones. We observed that PTC-bearing transcripts are packaged into viral particles at levels three- to fivefold less than those of control RNAs. Since PTC-mediated degradation requires translation, we conclude that RSV can package progeny virion particles using previously translated RNAs.
Acute Infection with Epstein-Barr Virus Targets and Overwhelms the Peripheral Memory B-Cell Compartment with Resting, Latently Infected Cells
Authors: Hochberg Donna , Souza Tatyana , Catalina Michelle , Sullivan John L. , Luzuriaga Katherine , Thorley-Lawson David A. 
Published: April 2004

ABSTRACT

In this paper we demonstrate that during acute infection with Epstein-Barr virus (EBV), the peripheral blood fills up with latently infected, resting memory B cells to the point where up to 50% of all the memory cells may carry EBV. Despite this massive invasion of the memory compartment, the virus remains tightly restricted to memory cells, such that, in one donor, fewer than 1 in 10
4
infected cells were found in the naive compartment. We conclude that, even during acute infection, EBV persistence is tightly regulated. This result confirms the prediction that during the early phase of infection, before cellular immunity is effective, there is nothing to prevent amplification of the viral cycle of infection, differentiation, and reactivation, causing the peripheral memory compartment to fill up with latently infected cells. Subsequently, there is a rapid decline in infected cells for the first few weeks that approximates the decay in the cytotoxic-T-cell responses to viral replicative antigens. This phase is followed by a slower decline that, even by 1 year, had not reached a steady state. Therefore, EBV may approach but never reach a stable equilibrium.
Analysis of Host Range Phenotypes of Primate Hepadnaviruses by In Vitro Infections of Hepatitis D Virus Pseudotypes
Authors: Barrera Azeneth , Guerra Bernadette , Lee Helen , Lanford Robert E. 
Published: April 2004

ABSTRACT
Hepatitis B virus (HBV) and woolly monkey hepatitis B virus (WMHBV) have natural host ranges that are limited to closely related species. The barrier for infection of primates seems to be at the adsorption and/or entry steps of the viral replication cycle, since a human hepatoma cell line is permissive for HBV and WMHBV replication following transfection of cloned DNA. We hypothesized that the HBV and WMHBV envelope proteins contain the principal viral determinants of host range. As previously shown by using the hepatitis D virus (HDV) system, recombinant HBV-HDV particles were infectious in chimpanzee as well as human hepatocytes. We extended the HDV system to include HDV particles pseudotyped with the WMHBV envelope. In agreement with the natural host ranges of HBV and WMHBV, in vitro infections demonstrated that HBV-HDV and WM-HDV particles preferentially infected human and spider monkey cells, respectively. Previous studies have implicated the pre-S1 region of the large (L) envelope protein in receptor binding and host range; therefore, recombinant HDV particles were pseudotyped with the hepadnaviral envelopes containing chimeric L proteins with the first 40 amino acids from the pre-S1 domain exchanged between HBV and WMHBV. Surprisingly, addition of the human amino terminus to the WMHBV L protein increased infectivity on spider monkey hepatocytes but did not increase infectivity for human hepatocytes. Based upon these data, we discuss the possibility that the L protein may be comprised of two domains that affect infectivity and that sequences downstream of residue 40 may influence host range and receptor binding or entry.
Cellular RNA Helicase p68 Relocalization and Interaction with the Hepatitis C Virus (HCV) NS5B Protein and the Potential Role of p68 in HCV RNA Replication
Authors: Goh Phuay-Yee , Tan Yee-Joo , Lim Siew Pheng , Tan Y. H. , Lim Seng Gee , Fuller-Pace Frances , Hong Wanjin 
Published: April 2004

ABSTRACT
Chronic infection by hepatitis C virus (HCV) can lead to severe hepatitis and cirrhosis and is closely associated with hepatocellular carcinoma. The replication cycle of HCV is poorly understood but is likely to involve interaction with host factors. In this report, we show that NS5B, the HCV RNA-dependent RNA polymerase (RdRp), interacts with a human RNA helicase, p68. Transient expression of NS5B alone, as well as the stable expression of all the nonstructural proteins in a HCV replicon-bearing cell line (V. Lohmann, F. Korner, J.-O. Koch, U. Herian, L. Theilmann, and R. Bartenschlager, Science 285:110-113), causes the redistribution of endogenous p68 from the nucleus to the cytoplasm. Deletion of the C-terminal two-thirds of NS5B (NS5BΔC) dramatically reduces its coimmunoprecipitation (co-IP) with endogenous p68, while the deletion of the N-terminal region (NS5BΔN1 and NS5BΔN2) does not affect its interaction with p68. In consistency with the co-IP results, NS5BΔC does not cause the relocalization of p68 whereas NS5BΔN1 does. With a replicon cell line, we were not able to detect a change in positive- and negative-strand synthesis when p68 levels were reduced using small interfering RNA (siRNA). In cells transiently transfected with a full-length HCV construct, however, the depletion (using specific p68 siRNA) of endogenous p68 correlated with a reduction in the transcription of negative-strand from positive-strand HCV RNA. Overexpression of NS5B and NS5BΔN1, but not that of NS5BΔC, causes a reduction in the negative-strand synthesis, indicating that overexpressed NS5B and NS5BΔN1 sequesters p68 from the replication complexes (thus reducing their replication activity levels). Identification of p68 as a cellular factor involved in HCV replication, at least for cells transiently transfected with a HCV expression construct, is a step towards understanding HCV replication.
Frequent Dual Initiation in Human Immunodeficiency Virus-Based Vectors Containing Two Primer-Binding Sites: a Quantitative In Vivo Assay for Function of Initiation Complexes
Authors: Voronin Yegor A. , Pathak Vinay K. 
Published: April 2004

ABSTRACT

We previously demonstrated that murine leukemia virus (MLV)-based vectors containing two primer-binding sites (PBSs) have the capacity to initiate reverse transcription more than once (Y. A. Voronin and V. K. Pathak, Virology
312:
281-294, 2003). To determine whether human immunodeficiency virus (HIV)-based vectors also have the capacity to initiate reverse transcription twice, we constructed an HIV type 1 (HIV-1)-based vector containing the HIV-1 PBS, a green fluorescent protein reporter gene (
GFP
), and a second PBS derived from HIV-2 3′ of
GFP
. Simultaneous initiation of reverse transcription at both the 5′ HIV-1 PBS and 3′ HIV-2 PBS was predicted to result in deletion of
GFP
. As in the MLV-based vectors,
GFP
was deleted in approximately 25% of all proviruses, indicating frequent dual initiation in HIV-based vectors containing two PBSs. Quantitative real-time PCR analysis of early reverse transcription products indicated that HIV-1 reverse transcriptase efficiently used the HIV-2 PBS. To investigate tRNA primer-RNA template interactions in vivo, we introduced several mutations in the HIV-2 U5 region. The effects of these mutations on the efficiency of reverse transcription initiation were measured by quantitative real-time PCR analysis of early reverse transcription products, with initiation at the HIV-1 PBS used as an internal control. Disruption of the lower and upper parts of the U5-inverted repeat stem reduced the efficiency of initiation 20- and 6-fold, respectively. In addition, disruption of the proposed interactions between viral RNA and tRNA
Lys3
thymidine-pseudouridine-cytidine and anticodon loops decreased the efficiency of initiation seven- and sixfold, respectively. These results demonstrate the relative influence of various RNA-RNA interactions on the efficiency of initiation in vivo. Furthermore, the two-PBS vector system provides a sensitive and quantitative in vivo assay for analysis of RNA-RNA and protein-RNA interactions that can influence the efficiency of reverse transcription initiation.
Induction of Disease by a Molecularly Cloned Highly Pathogenic Simian Immunodeficiency Virus/Human Immunodeficiency Virus Chimera Is Multigenic
Authors: Sadjadpour Reza , Theodore Theodore S. , Igarashi Tatsuhiko , Donau Olivia K. , Plishka Ronald J. , Buckler-White Alicia , Martin Malcolm A. 
Published: April 2004

ABSTRACTOne of three full-length infectious molecular clones of SHIVDH12R, designated SHIVDH12R-CL-7and obtained from productively infected rhesus monkey peripheral blood mononuclear cells, directed rapid and irreversible loss of CD4+T cells within 3 weeks of its inoculation into Indian rhesus monkeys. Induction of complete CD4+T-cell depletion by SHIVDH12R-CL-7was found to be dependent on inoculum size. The acquisition of this pathogenic phenotype was accompanied by the introduction of 42 amino acid substitutions into multiple genes of parental nonpathogenic SHIVDH12. Transfer of the entire SHIVDH12R-CL-7envgene into the genetic background of nonpathogenic SHIVDH12failed to confer the rapid CD4+T-lymphocyte-depleting syndrome; similarly, the substitution ofgagpluspolsequences from SIVsmE543for analogous SIVmac239genes in SHIVDH12R-CL-7attenuated the pathogenic phenotype. Amino acid changes affecting multiple viral genes are necessary, but insufficient by themselves, to confer the prototypically rapid and irreversible CD4+T-cell-depleting phenotype exhibited by molecularly cloned SHIVDH12R-CL-7.
Effects of Antibody on Viral Kinetics in Simian/Human Immunodeficiency Virus Infection: Implications for Vaccination
Authors: Zhang Lei , Ribeiro Ruy M. , Mascola John R. , Lewis Mark G. , Stiegler Gabriela , Katinger Hermann , Perelson Alan S. , Davenport Miles P. 
Published: April 2004

ABSTRACT
Passive antibody treatment of macaques prior to simian/human immunodeficiency virus infection produces “sterilizing immunity” in some animals and long-term reductions in viral loads in others. Analysis of viral kinetics suggests that antibody mediates sterilizing immunity by its effects on the initial viral inoculum. By contrast, reduction in peak viral load later in infection prevents CD4 depletion and contributes to long-term viral control.
Lessons Learned from Political Violence and Genocide in Teaching a Psychology of Peace: An Interview with Linda Woolf
Authors: Howe Tasha R. 
Published: April 2004

Tasha R. Howe got her BA in psychology from the University of California at Santa Barbara. She received her MA and PhD in developmental psychology from the University of California, Riverside. After doing an NIMH-sponsored postdoctoral fellowship in developmental psychopathology at Vanderbilt University, she served as assistant professor of psychology at Transylvania University in Lexington, Kentucky. Currently as assistant professor of psychology at Humboldt State University in California, Dr. Howe specializes in child abuse, family violence, developmental psychopathology, community violence, and ecological factors affecting normal and atypical child development. She teaches a wide variety of courses, including human development, the history of psychology, family violence, assessment and treatment of child abuse and neglect, children's cognitive development, and developmental psychopathology. She is married and has two sons, ages 6 and 1. Linda M. Woolf is the Coordinator of Holocaust and Genocide Studies and Professor of Psychology at Webster University in St. Louis, Missouri. She received her MS and PhD in applied-experimental psychology from Saint Louis University. She currently serves as Review Editor for the e-journal H-Genocide, secretary for the Society for the Teaching of Psychology (Division 2, APA), and an executive committee member for the Society for the Study of Peace, Conflict, and Violence (Division 48, APA). In addition to her courses on the Holocaust, genocide, peace and conflict, and women and global human rights, Dr. Woolf also teaches a wide variety of courses such as women's intellectual contributions to the study of mind and society, the history and systems of psychology, social psychology, adult development and aging, and introductory psychology. She loves baseball, Star Trek, and her dogs and cats!
Nanolithographie und Nanochemie: Sondentechniken zur Strukturierung und chemischen Modifizierung von Nanobauelementen
Authors: Wouters Daan , Schubert Ulrich S. 
Published: April 2004

AbstractDa photolithographisch nicht beliebig kleine Bauelemente hergestellt werden können, werden andere Strukturierungstechniken intensiv untersucht. Insbesondere Rastersondenlithographie‐Techniken gelten als vielversprechend für die Erzeugung solcher Strukturen, und da ihre Anwendung relativ einfach ist, sind diese Methoden inzwischen weit verbreitet. Beispiele sind die Dip‐Pen‐Lithographie und die kraftinduzierte lokale Strukturierung ebenso wie die lokale Oxidation mit Sonden. Diese Techniken sind besonders interessant, da so Nanostrukturen erhalten werden, die chemisch und physikalisch modifiziert und funktionalisiert werden können. Somit ist nicht nur die Produktion von elektronischen Bauelementen möglich, sondern auch die Erzeugung von Strukturen für die molekulare Erkennung oder die Sensorik. Wir zeigen hier die Fortschritte bei der Entwicklung von automatisierten Multispitzen‐Rastersondensystemen und ihre Anwendung bei der lokalen Oxidation. Außerdem erläutern wir den Stand der Technik und die Perspektiven von Nanobauelementen.
Development of calibration models for estimation of monomer concentration by Raman spectroscopy during emulsion polymerization: Facing the medium heterogeneity
Authors: Reis Marlon M. , Araújo Pedro H. H. , Sayer Claudia , Giudici Reinaldo 
Published: April 2004

AbstractThis work compares different calibration models for the estimation of monomer concentrations by Raman spectroscopy during semicontinuous emulsion copolymerization reactions. The limitations of these models are discussed in terms of a complex reaction, namely the copolymerization of vinyl acetate and butyl acrylate, whose monomers present overlapping Raman spectra, especially the C=C stretching band. Additionally, the copolymerization was monitored in a spectroscopic setup arranged for fast spectral acquisition, which resulted in a low signal‐to‐noise ratio. These realistic conditions for in‐line monitoring of emulsion copolymerization, i.e., considerable noise level in the spectra and medium heterogeneity, are discussed in the context of different approaches for adjusting the calibration model and the ensuing model limitations. It was verified that combining data obtained during reactions with synthetic samples is interesting from the statistical point of view, since in this way it is possible to produce data sets with a wide range of variation, allowing the accurate estimation of statistical parameters. These parameters are of major importance for process variables and product property estimations, especially if they are to be used for process control and decision making purposes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1136–1150, 2004
A study on the biodegradability of polyethylene terephthalate fiber and diethylene glycol terephthalate
Authors: Zhang Jianfei , Wang Xiaochun , Gong Jixian , Gu Zhenya 
Published: April 2004

AbstractThe degradation of diethylene glycol terephthalate (DTP) and polyethylene terephthalate fiber (PET fiber) by microbes and lipase was studied. The HPLC method was used to determine the degradation ratio and degradation rule of DTP. Greater than 90% DTP was degraded by microbes in 24 days and 40% by lipase in 24 h. The degradation of DTP can be described by the first‐order reaction model. Although the biodegradation ratio of PET fiber was still weak, we demonstrated with SEM micrographs and HPLC analysis that microbes and lipase could act on the PET fiber and there were some cracks on the surface of the fiber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1089–1096, 2004
Effect of clay concentration on the oxygen permeability and optical properties of a modified poly(vinyl alcohol)
Authors: Grunlan Jaime C. , Grigorian Ani , Hamilton Charles B. , Mehrabi Ali R. 
Published: April 2004

AbstractThe effect of clay concentration on the oxygen permeability and optical properties of a modified poly(vinyl alcohol) (PVOH) was studied. Sodium montmorrilonite (MMT‐Na+), at a concentration of 10 wt %, was found to decrease the oxygen permeability of the PVOH below 0.001 cc · mil/m2/day at 55% relative humidity. This low permeability is attributed to the strong interaction between PVOH and clay, as evidenced by an increase of more than 10°C in the glass transition temperature at this concentration. Transmission electron microscopy images show the high level of clay exfoliation that results from the strong affinity to PVOH. Haze and clarity were optical properties that changed significantly with increasing clay concentration. These values were 0.4 and 100%, respectively, in the absence of clay, but became 80 and 23% with 10 wt % MMT‐Na+. Transmission did not change as considerably, reaching a low of 73% with a clay concentration of 10 wt %. The ability to reduce the oxygen permeability of PVOH‐based systems at elevated humidity may prove advantageous for applications in food and flexible electronics packaging, where moisture sensitivity currently prevents them from being used. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1102–1109, 2004
Effect of bound rubber on characteristics of highly filled styrene–butadiene rubber compounds with different types of carbon black
Authors: Choi Sung‐Seen 
Published: April 2004

AbstractViscosity and cure time of a filled rubber compound having an accelerated sulfur cure system are affected by types and contents of the rubber and the filler as well as of the curatives. Bound rubber content is used as level of the reinforcement. Influence of bound rubber on viscosity and cure time of a rubber compound was studied using highly filled styrene–butadiene rubber compounds with carbon black having different structures. The bound rubber content increases with increase of the carbon black content and also increases as the carbon black structure is developed. The Mooney viscosity increases linearly with increase of the bound rubber content irrespective of the carbon black structure when the primary particle size of carbon black is nearly the same. The Mooney scorch time decreases linearly with increase of the bound rubber content irrespective of the carbon black structure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1001–1006, 2004