bluuebunny/crossref_metadata_2025_split huggingface dataset:
Herpes Simplex Virus Type 1 Regulatory Protein ICP0 Does Not Protect Cyclins D1 and D3 from Degradation during Infection
Authors: Everett Roger D. 
Published: August 2004

ABSTRACT
Previous reports have suggested that herpes simplex virus type 1 (HSV-1) immediate-early regulatory protein ICP0 stabilizes cyclins D1 and D3 during infection by inducing the degradation of cdc34, the E2-conjugating enzyme that is responsible for regulating the stability of these cyclins. Since ICP0 has complex effects on the progress of viral infection that vary greatly with cell type and viral dose, it can be difficult to distinguish between direct effects caused by ICP0 itself and indirect effects caused by the rate of the progression of infection in the absence of ICP0 at the chosen multiplicity of infection. This report describes the fates of cdc34 and cyclins D1 and D3 during HSV-1 infection under conditions that ensured that viral infection and gene expression were proceeding at equivalent rates in the presence and absence of ICP0. It was confirmed that both D-type cyclins were unstable during HSV-1 infection of a variety of cell types, but no effect on cdc34 was observed, even when high levels of ICP0 were expressed. Furthermore, there was no evidence that ICP0 protected either cyclin D1 or cyclin D3 from degradation. Reconstruction of the conditions of the experiments in the previous studies, using the stated cell type and multiplicities of infection, indicated that the original results could be explained by differences in the rate of progression of infection rather than by the presence or absence of ICP0. The data presented in this report are incompatible with the hypothesis that ICP0 induces the degradation of cdc34 and thereby stabilizes cyclins D1 and D3 during HSV-1 infection.
Involvement of a Bovine Viral Diarrhea Virus NS5B Locus in Virion Assembly
Authors: Ansari Israrul H. , Chen Li-Mei , Liang Delin , Gil Laura H. , Zhong Weidong , Donis Ruben O. 
Published: August 2004

ABSTRACTA novel mutant of bovine viral diarrhea virus (BVDV) was found with a virion assembly phenotype attributable to an insertion into the NS5B polymerase locus. This mutant, termed 5B-741, was engineered by reverse genetics to express NS5B with a C-terminal peptide tag of 22 amino acids. Electroporation of bovine cells with genomic RNA from this mutant showed levels RNA synthesis which were regarded as sufficient for infectivity, yet infectious virions were not produced. Pseudorevertants of mutant 5B-741 that released infectious virions and formed plaques revealed a single nucleotide change (T12369C). This change resulted in a leucine-to-proline substitution within the NS5B tag (L726P). Genetic analysis revealed that indeed a single nucleotide change encoding proline at NS5B position 726 in the pseudorevertant polyprotein mediated recovery of virion assembly function without improving genomic RNA accumulation levels. A subgenomic BVDV reporter replicon (rNS3-5B) was used to analyze the consequences of alterations of the genomic region encoding the NS5B C terminus on replication and assembly. Interestingly, rNS3-5B-L726P (revertant) replicated with the same efficiency as the rNS3-5B-741 mutant but produced 10 times more virions in atrans-packaging assay. These results indicated that impairment of assembly function in 5B-741 was independent of RNA accumulation levels and agreed with the observations from the full-length mutant and revertant genomes. Finally, we recapitulated the packaging defect of 5B-741 with a vaccinia virus expression system to eliminate possible unwanted interactions between the helper virus and the packaged replicon. Taken together, these studies revealed an unexpected role of NS5B in infectious virion assembly.
A Mutant of Sindbis Virus Which Is Able To Replicate in Cells with Reduced CTP Makes a Replicase/Transcriptase with a Decreased

K
m

for CTP
Authors: Li Mei-Ling , Lin Yen-Huei , Simmonds H. Anne , Stollar Victor 
Published: August 2004

ABSTRACT

We reported earlier the isolation and characterization of a Sindbis virus mutant, SV
PZF
, that can grow in mosquito cells treated with pyrazofurin (PZF), a compound that interferes with pyrimidine biosynthesis (Y. H. Lin, P. Yadav, R. Ravatn, and V. Stollar, Virology 272:61-71, 2000; Y. H. Lin, H. A. Simmonds, and V. Stollar, Virology 292:78-86, 2002). Three amino acid changes in nsP4, the viral RNA polymerase, were required to produce this phenotype. We now describe a mutant of Sindbis virus, SV
CPC
, that is resistant to cyclopentenylcytosine (CPC), a compound that interferes only with the synthesis of CTP. Thus, in contrast to SV
PZF
, which was selected for its ability to grow in mosquito cells with low levels of UTP and CTP, SV
CPC
was selected for its ability to grow in cells in which only the level of CTP was reduced. Although SV
PZF
was cross-resistant to CPC, SV
CPC
was not resistant to PZF. Only one amino acid change in nsP4, Leu 585 to Phe, was required for the CPC resistance phenotype. The viral replicase/transcriptase generated in SV
CPC
-infected mosquito cells had a lower

K
m

for CTP (but not for UTP) than did the enzyme made in SV
STD
-infected mosquito cells. SV
PZF
and SV
CPC
represent the first examples of viral mutants selected for the ability to grow in cells with low levels of ribonucleoside triphosphates (rNTPs). Further study of these mutants and determination of the structure of nsP4 should demonstrate how alterations in an RNA-dependent RNA polymerase permit it to function in cells with abnormally low levels of rNTPs.
Genetic Relationships and Evolution of Genotypes of Yellow Fever Virus and Other Members of the Yellow Fever Virus Group within the
Flavivirus
Genus Based on the 3′ Noncoding Region
Authors: Mutebi John-Paul , Rijnbrand René C. A. , Wang Heiman , Ryman Kate D. , Wang Eryu , Fulop Lynda D. , Titball Rick , Barrett Alan D. T. 
Published: August 2004

ABSTRACT
Genetic relationships among flaviviruses within the yellow fever (YF) virus genetic group were investigated by comparing nucleotide sequences of the 3′ noncoding region (3′NCR). Size heterogeneity was observed between members and even among strains of the same viral species. Size variation between YF strains was due to duplications and/or deletions of repeated nucleotide sequence elements (RYF). West African genotypes had three copies of the RYF (RYF1, RYF2, and RYF3); the Angola and the East and Central African genotypes had two copies (RYF1 and RYF3); and South American genotypes had only a single copy (RYF3). Nucleotide sequence analyses suggest a deletion within the 3′NCR of South American genotypes, including RYF1 and RYF2. Based on studies with the French neurotropic vaccine strain, passage of a YF virus strain in cell culture can result in deletion of RYF1 and RYF2. Taken together, these observations suggest that South American genotypes of YF virus evolved from West African genotypes and that the South American genotypes lost RYF1 and RYF2, possibly in a single event. Repeated sequence elements were found within the 3′NCR of other members of the YF virus genetic group, suggesting that it is probably characteristic for members of the YF virus genetic group. A core sequence of 15 nucleotides, containing two stem-loops, was found within the 3′NCR of all members of the YF genetic group and may represent the progenitor repeat sequence. Secondary structure predictions of the 3′NCR showed very similar structures for viruses that were closely related phylogenetically.
Interactions of Foot-and-Mouth Disease Virus with Soluble Bovine α
V
β
3
and α
V
β
6
Integrins
Authors: Duque Hernando , LaRocco Michael , Golde William T. , Baxt Barry 
Published: August 2004

ABSTRACT

At least four members of the integrin family of receptors, α
V
β
1
, α
V
β
3
, α
V
β
6
, and α
V
β
8
, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro. Our investigators have recently shown that the efficiency of receptor usage appears to be related to the viral serotype and may be influenced by structural differences on the viral surface (H. Duque and B. Baxt, J. Virol.
77:
2500-2511, 2003). To further examine these differences, we generated soluble α
V
β
3
and α
V
β
6
integrins. cDNA plasmids encoding the individual complete integrin α
V
, β
3
, and β
6
subunits were used to amplify sequences encoding the subunits' signal peptide and ectodomain, resulting in subunits lacking transmembrane and cytoplasmic domains. COS-1 cells were transfected with plasmids encoding the soluble α
V
subunit and either the soluble β
3
or β
6
subunit and labeled with [
35
S]methionine-cysteine. Complete subunit heterodimeric integrins were secreted into the medium, as determined by radioimmunoprecipitation with specific monoclonal and polyclonal antibodies. For the examination of the integrins' biological activities, stable cell lines producing the soluble integrins were generated in HEK 293A cells. In the presence of divalent cations, soluble α
V
β
6
bound to representatives of type A or O viruses, immobilized on plastic dishes, and significantly inhibited viral replication, as determined by plaque reduction assays. In contrast, soluble α
V
β
3
was unable to bind to immobilized virus of either serotype; however, virus bound to the immobilized integrin, suggesting that FMDV binding to α
V
β
3
is a low-affinity interaction. In addition, soluble α
V
β
3
did not neutralize virus infectivity. Incubation of soluble α
V
β
6
with labeled type A
12
or O
1
resulted in a significant inhibition of virus adsorption to BHK cells, while soluble α
V
β
3
caused a low (20 to 30%), but consistent, inhibition of virus adsorption. Virus incubated with soluble α
V
β
6
had a lower sedimentation rate than native virus on sucrose density gradients, but the particles retained all of their structural proteins and still contained bound integrin and, therefore, were not exhibiting characteristics of a picornavirus A particle.
Long-Term Persistence of Infection in Chimpanzees Inoculated with an Infectious Hepatitis C Virus Clone Is Associated with a Decrease in the Viral Amino Acid Substitution Rate and Low Levels of Heterogeneity
Authors: Fernandez Javier , Taylor Deborah , Morhardt Duncan R. , Mihalik Kathleen , Puig Montserrat , Rice Charles M. , Feinstone Stephen M. , Major Marian E. 
Published: August 2004

ABSTRACTTwo chimpanzees, 1535 and 1536, became persistently infected following inoculation with RNA transcripts from cDNA clones of hepatitis C virus (HCV). Analysis of the HCV genomes from both animals showed an accumulation of amino acid substitutions over time. The appearance of substitutions in the envelope genes was associated with increased antienvelope antibody titers. However, extensive mutations were not incorporated into hypervariable region 1 (HVR1). A comparison of the nonsynonymous substitution rate/synonymous substitution rate was made at various time points to analyze selective pressure. The highest level of selective pressure occurred during the acute phase and decreased as the infection continued. The nonsynonymous substitution rate was initially higher than the synonymous substitution rate but decreased over time from 3.3 × 10−3(chimpanzee 1535) and 3.2 × 10−3(chimpanzee 1536) substitutions/site/year at week 26 to 1.4 × 10−3(chimpanzee 1535) and 1.7 × 10−3(chimpanzee 1536) at week 216, while the synonymous substitution rate remained steady at ∼1 × 10−3substitutions/site/year. Analysis of PCR products using single-stranded conformational polymorphism indicated a low level of heterogeneity in the viral genome. The results of these studies confirm that the persistence of infection is not solely due to changes in HVR1 or heterogeneity and that the majority of variants observed in natural infections could not arise simply through mutation during the time period most humans and chimpanzees are observed. These data also indicate that immune pressure and selection continue throughout the chronic phase.
Interspecific Recombination between Two Ruminant Alphaherpesviruses, Bovine Herpesviruses 1 and 5
Authors: Meurens François , Keil Günther M. , Muylkens Benoît , Gogev Sacha , Schynts Frédéric , Negro Sandra , Wiggers Laetitia , Thiry Etienne 
Published: August 2004

ABSTRACTHomologous recombination between different species of alphaherpesviruses has been described between herpes simplex viruses 1 and 2 but has not yet been observed between other alphaherpesviruses. In the present study we chose to assess to what extent in vitro recombination can occur between members of a well-defined group of closely related viruses such as ruminant alphaherpesviruses. At 24 h after infection of epithelial bovine kidney cells with a double-deleted mutant of bovine herpesvirus 1 (BoHV-1) (containing green fluorescent protein and red fluorescent protein genes) and different ruminant alphaherpesviruses, four types of progeny viruses were detected and distinguished according to their phenotype. Frequent recombination events between identical or different strains of BoHV-1 were observed (up to 30%), whereas only two BoHV-1/BoHV-5 recombinants were identified, and no recombinants between BoHV-1 and less closely related caprine and cervine herpesviruses were detected. Restriction analysis of the genomes of the two BoHV-1/BoHV-5 recombinants showed different genetic backgrounds. One possessed a restriction pattern close to BoHV-1, whereas the other one was close to BoHV-5. This exhaustive analysis of each combination of coinfection in a unique situation of five closely related alphaherpesviruses revealed the importance of a high degree of genetic relatedness and similar parental virus growth kinetics for successful interspecific recombination.
Molecular, Biological, and In Vivo Characterization of the Guinea Pig Cytomegalovirus (CMV) Homologs of the Human CMV Matrix Proteins pp71 (UL82) and pp65 (UL83)
Authors: McGregor Alistair , Liu Fenyong , Schleiss Mark R. 
Published: August 2004

ABSTRACT
We recently identified the genes encoding the guinea pig cytomegalovirus (GPCMV) homologs of the upper and lower matrix proteins of human CMV, pp71 (UL82) and pp65 (UL83), which we designated GP82 and GP83, respectively. Transient-expression studies with a GP82 plasmid demonstrated that the encoded protein targets the nucleus and that the infectivity and plaquing efficiency of cotransfected GPCMV viral DNA was enhanced by GP82. The transactivation function of GP82 was not limited to GPCMV, but was also observed for a heterologous virus, herpes simplex virus type 1 (HSV-1). This was confirmed by its ability to complement the growth of an HSV-1 VP16 transactivation-defective mutant virus in an HSV viral DNA cotransfection assay. Study of a GP82 “knockout” virus (and its attendant rescuant), generated on a GPCMV bacterial artificial chromosome construct, confirmed the essential nature of the gene. Conventional homologous recombination was used to generate a GP83 mutant to examine the role of GP83 in the viral life cycle. Comparison of the one-step growth kinetics of the GP83 mutant (vAM409) and wild-type GPCMV indicated that GP83 protein is not required for viral replication in tissue culture. The role of GP83 in vivo was examined by comparing the pathogenesis of wild-type GPCMV, vAM409, and a control virus, vAM403, in guinea pigs. The vAM409 mutant was significantly attenuated for dissemination in immunocompromised strain 2 guinea pigs, suggesting that the GP83 protein is essential for full pathogenicity in vivo.
Current smoking and the risk of non-fatal myocardial infarction in the WHO MONICA Project populations
Authors: Mähönen M S , McElduff P , Dobson A J , Kuulasmaa K A , Evans A E 
Published: August 2004

Background:Cohort studies have shown that smoking has a substantial influence on coronary heart disease mortality in young people. Population based data on non-fatal events have been sparse, however.Objective:To study the impact of smoking on the risk of non-fatal acute myocardial infarction (MI) in young middle age people.Methods:From 1985 to 1994 all non-fatal MI events in the age group 35–64 were registered in men and women in the WHO MONICA (multinational monitoring of trends and determinants in cardiovascular disease) project populations (18 762 events in men and 4047 in women from 32 populations from 21 countries). In the same populations and age groups 65 741 men and 66 717 women participated in the surveys of risk factors (overall response rate 72%). The relative risk of non-fatal MI for current smokers was compared with non-smokers, by sex and five year age group.Results:The prevalence of smoking in people aged 35–39 years who experienced non-fatal MI events was 81% in men and 77% in women. It declined with increasing age to 45% in men aged 60–64 years and 36% in women, respectively. In the 35–39 years age group the relative risk of non-fatal MI for smokers was 4.9 (95% confidence interval (CI) 3.9 to 6.1) in men and 5.3 (95% CI 3.2 to 8.7) in women, and the population attributable fractions were 65% and 55%, respectively.Conclusions:During the study period more than half of the non-fatal MIs occurring in young middle age people can be attributed to smoking.
Current smoking among young adolescents: assessing school based contextual norms: Table 1
Authors: Pokorny S B , Jason L A , Schoeny M E 
Published: August 2004

Objective:To extend research on the relation of school based contextual norms to current smoking among adolescents by using three analytic techniques to test for contextual effects. It was hypothesised that significant contextual effects would be found in all three models, but that the strength of these effects would vary by the statistical rigor of the model.Design:Three separate analytic approaches were conducted on baseline self report student survey data from a larger study to test the relation between school level perceived peer tobacco use and individual current smoking status.Participants:A representative sample of 5399 sixth through eighth grade students in 14 midwestern middle schools completed the survey. All enrolled sixth through eighth grade students were eligible to participate in the survey. The student participation rate was 91.4% for the entire sample, and did not differ significantly between the schools (range 82–100%).Main outcome measure:Thirty day cigarette smoking prevalence.Results:A level 2 only model based on aggregated individual responses indicated that students in schools with higher average reported peer tobacco use were more likely to be current smokers than students in schools with lower average peer tobacco use. Using a level 1 only model based on individual responses indicated that the effect of school level perceived peer tobacco use on current smoking was significant when individual perceived peer tobacco use was excluded from the model but was non-significant when individual perceived peer tobacco use was added to the model. A multilevel model also indicated that the effect of school level perceived peer tobacco use on current smoking was not significant when individual perceived peer tobacco use was added to the model.Conclusion:The analytic approach used to examine contextual effects using individuals’ reports of peer tobacco use norms that were aggregated to obtain a context measure of the school norms may produce statistical artefacts that distort the association of the school context in general, and peer tobacco use norms in particular, with increased risk for current smoking beyond the risk associated with individual factors.
Recent trends in home and work smoking bans
Authors: Levy D T , Romano E , Mumford E A 
Published: August 2004

Objectives:Home and work smoking bans at the national and state level in the USA, and their relation to smoking prevalence and to tobacco control policies, are examined.Data:The Current Population Survey’s 1992/93 and 1998/99 tobacco use supplement surveys are the primary data source, supplemented with information on state level tobacco control policies.Methods:The national and state rate of bans are estimated, and changes over the course of the 1990s and their relation to smoking rates and tobacco control policies are examined.Results:The prevalence of work and home bans has increased considerably between 1992/93 and 1998/99. By 1999, over 65% of the population age 15 and above work in places with smoking bans, and over 60% live in homes with bans. We found that states with lower than average ban rates in 1993 tended to have had larger increases in ban rates between 1993 and 1999. We also found that home and work bans became more prevalent in states with initially low smoking rates, and that the growth in home bans coincided with a declining prevalence of smoking. States with higher levels of bans by 1999 also tended to have higher cigarette taxes, stricter clean air laws, and media/comprehensive campaigns in place.Conclusions:The results indicate that lower smoking rates are associated with higher rates of work and home bans, although substantial progress has also been made by those states with initially low rates of bans. While further work is needed to establish the direction of causality, it would appear that reductions in smoking rates, either through stronger tobacco control policies or otherwise, may reduce exposure to tobacco smoke not only by reducing the number of smokers, but also through increasing the number of firms and homes with smoking restrictions.
The impact of anti-tobacco industry prevention messages in tobacco producing regions: evidence from the US truth® campaign
Authors: Thrasher J F , Niederdeppe J , Farrelly M C , Davis K C , Ribisl K M , Haviland M L 
Published: August 2004

Background:Adolescents who live in tobacco producing regions may not respond favourably to anti-industry ads.Objective:To examine whether state level involvement in tobacco production appears to limit the effectiveness of anti-industry ads to prevent tobacco use among adolescents in the USA.Design:Time trend analyses were done using repeated cross sectional data from six waves of the Legacy Media Tracking Survey, which were collected between 1999 and 2003.Setting and participants:28 307 adolescents, ages 12–17 years, were classified as living in: tobacco producing states (TPS) (n  =  1929); non-tobacco producing states (non-TPS) with low tobacco control funding comparable to TPS (n  =  5323); non-TPS with relatively high funding (n  =  15 076); and non-TPS with established anti-industry ad campaigns (n  =  5979).Main outcome measures:Reactions to anti-industry ads; strength of anti-industry attitudes/beliefs; changes in anti-industry attitudes/beliefs over time.Results:Ad reactions did not differ by state type. Multivariate adjusted time trend analyses indicated significant, comparable increases in anti-industry attitudes/beliefs since the onset of the truth® campaign, in both TPS and non-TPS. Mediation analyses indicated that these increases were due, in part, to campaign exposure.Conclusions:Adolescents who live in tobacco producing regions appear to be as responsive to anti-industry ads as their counterparts in non-tobacco producing regions. This study provides further evidence for the effectiveness of such ads.