bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles of Human Parainfluenza Virus Type 3 Bases 13 to 78 in Replication and Transcription: Identification of an Additional Replication Promoter Element and Evidence for Internal Transcription Initiation
Authors: Hoffman Michael A. , Thorson LeeAnne M. , Vickman John E. , Anderson Joseph S. , May Nathan A. , Schweitzer Michelle N. 
Published: May 2006

ABSTRACT

The genomic promoter of human parainfluenza virus type 3 (HPIV3) contains multiple
cis
-elements controlling transcription and replication. Previous work showed that regions 1 to 12 and 79 to 96 were critical in promoting replication of an HPIV3 minireplicon, while the intergenic sequence and N gene start signal (IS/Ngs, bases 49 to 61) were important for transcription. Because these data were collected primarily using point mutations, not every base from position 1 to 96 was analyzed, and some important control elements may have been missed. To clarify the role of bases 13 to 78 in transcription and replication, a series of mutations were made which collectively scanned this entire region. Mutation of bases 13 to 28 resulted in markedly decreased HPIV3 minireplicon replication, indicating these bases constitute an additional
cis
-element involved in the synthesis of the HPIV3 antigenomic RNA. The position dependence of the IS/Ngs was also examined. Analysis of mutants in which the IS/Ngs was shifted 5′ or 3′ showed that this segment could be moved without significantly disrupting transcription initiation. Additional mutants which contained two successive IS/Ngs segments were created to test whether the polymerase accessed the gene start signal by proceeding along the template 3′ to 5′ or by binding internally at the gene start signal. Based on analysis of the double gene start mutants, we propose a model of internal transcription initiation in which the polymerase enters the template at approximately the location of the natural N gene start but then scans the template bidirectionally to find a gene start signal and initiate transcription.
Two Surface-Exposed Elements of the B30.2/SPRY Domain as Potency Determinants of N-Tropic Murine Leukemia Virus Restriction by Human TRIM5α
Authors: Perron Michel J. , Stremlau Matthew , Sodroski Joseph 
Published: May 2006

ABSTRACT

Human TRIM5α (TRIM5α
hu
) potently restricts N-tropic (N-MLV), but not B-tropic, murine leukemia virus in a manner dependent upon residue 110 of the viral capsid. Rhesus monkey TRIM5α (TRIM5α
rh
) inhibits N-MLV only weakly. The study of human-monkey TRIM5α chimerae revealed that both the v1 and v3 variable regions of the B30.2/SPRY domain contain potency determinants for N-MLV restriction. These variable regions are predicted to be surface-exposed elements on one face of the B30.2 domain. Acidic residues in v3 complement basic residue 110 of the N-MLV capsid. The results support recognition of the retroviral capsid by the TRIM5α B30.2 domain.
Silencing of Hepatitis A Virus Infection by Small Interfering RNAs
Authors: Kusov Yuri , Kanda Tatsuo , Palmenberg Ann , Sgro Jean-Yves , Gauss-Müller Verena 
Published: May 2006

ABSTRACT
Infection by hepatitis A virus (HAV) can cause acute hepatitis and, rarely, fulminant liver failure, in particular in patients chronically infected with hepatitis C virus. Based on our previous observation that small interfering RNAs (siRNAs) can silence translation and replication of the firefly luciferase-encoding HAV replicon, we now exploited this technology to demonstrate the effect of siRNAs on viral infection in Huh-7 cells. Freshly and persistently infected cells were transfected with siRNAs targeting various sites in the HAV nonstructural genes. Compared to a single application, consecutive siRNA transfections targeting multiple sequences in the viral genome resulted in a more efficient and sustained silencing effect than a single transfection. In most instances, multiple applications of a single siRNA led to the emergence of viral escape mutants with mutated target sites that rendered these genomes resistant to RNA interference (RNAi). Efficient and sustained suppression of the viral infectivity was achieved after consecutive applications of an siRNA targeting a computer-predicted hairpin structure. This siRNA holds promise as a therapeutic tool for severe courses of HAV infection. In addition, the results provide new insight into the structural bases for sequence-specific RNAi.
Furin Cleavage Potentiates the Membrane Fusion-Controlling Intersubunit Disulfide Bond Isomerization Activity of Leukemia Virus Env
Authors: Sjöberg Mathilda , Wallin Michael , Lindqvist Birgitta , Garoff Henrik 
Published: May 2006

ABSTRACT
The membrane fusion protein of murine leukemia virus is a trimer of a disulfide-linked peripheral-transmembrane (SU-TM) subunit complex. The intersubunit disulfide bond is in SU linked to a disulfide bond isomerization motif, CXXC, with which the virus controls its fusion reaction (M. Wallin, M. Ekström, and H. Garoff, EMBO J. 23:54-65, 2004). Upon receptor binding the isomerase rearranges the intersubunit disulfide bond into a disulfide bond isomer within the motif. This facilitates SU dissociation and fusion activation in the TM subunit. In the present study we have asked whether furin cleavage of the Env precursor potentiates the isomerase to be triggered. To this end we accumulated the late form of the precursor, gp90, in the cell by incubation in the presence of a furin-inhibiting peptide. The isomerization was done by NP-40 incubation or by a heat pulse under alkylation-free conditions. The cells were lysed in the presence of alkylator, and the precursor was immunoprecipitated, gel isolated, deglycosylated, and subjected to complete trypsin digestion. Disulfide-linked peptide complexes were separated by sodium dodecyl sulfate-tricine-polyacrylamide gel electrophoresis under nonreducing conditions. This assay revealed the size of the characteristic major disulfide-linked peptide complex that differentiates the two isomers of the disulfide bond between Cys336 (or Cys339) and Cys563, i.e., the bond corresponding to the intersubunit disulfide bond. The analyses showed that the isomerase was five- to eightfold more resistant to triggering in the precursor than in the mature, cleaved form. This suggests that the isomerase becomes potentiated for triggering by a structural change in Env that is induced by furin cleavage in the cell.
Human Papillomavirus Type 16 E6 Activates NF-κB, Induces cIAP-2 Expression, and Protects against Apoptosis in a PDZ Binding Motif-Dependent Manner
Authors: James Michael A. , Lee John H. , Klingelhutz Aloysius J. 
Published: May 2006

ABSTRACT
Infection with human papillomavirus (HPV) is a critical factor in the pathogenesis of most cervical cancers and some aerodigestive cancers. The HPV E6 oncoprotein from high-risk HPV types contributes to the immortalization and transformation of cells by multiple mechanisms, including degradation of p53, transcriptional activation of human telomerase reverse transcriptase (hTERT), and degradation of several proteins containing PDZ domains. The ability of E6 to bind PDZ domain-containing proteins is independent of p53 degradation or hTERT activation but does correlate with oncogenic potential (R. A. Watson, M. Thomas, L. Banks, and S. Roberts, J. Cell Sci. 116:4925-4934, 2003) and is essential for induction of epithelial hyperplasia in vivo (M. L. Nguyen, M. M. Nguyen, D. Lee, A. E. Griep, and P. F. Lambert, J. Virol. 77:6957-6964, 2003). In this study, we found that HPV type 16 E6 was able to activate NF-κB in airway epithelial cells through the induction of nuclear binding activity of p52-containing NF-κB complexes in a PDZ binding motif-dependent manner. Transcript accumulation for the NF-κB-responsive antiapoptotic gene encoding cIAP-2 and binding of nuclear factors to the proximal NF-κB binding site of the cIAP-2 gene promoter are induced by E6 expression. Furthermore, E6 is able to protect cells from TNF-induced apoptosis. All of these E6-dependent phenotypes are dependent on the presence of the PDZ binding motif of E6. Our results imply a role for targeting of PDZ proteins by E6 in NF-κB activation and protection from apoptosis in airway epithelial cells.
Characterization of the Early Steps of Hepatitis C Virus Infection by Using Luciferase Reporter Viruses
Authors: Koutsoudakis George , Kaul Artur , Steinmann Eike , Kallis Stephanie , Lohmann Volker , Pietschmann Thomas , Bartenschlager Ralf 
Published: May 2006

ABSTRACT
The lack of an efficient system to produce hepatitis C virus (HCV) particles has impeded the analysis of the HCV life cycle. Recently, we along with others demonstrated that transfection of Huh7 hepatoma cells with a novel HCV isolate (JFH1) yields infectious viruses. To facilitate studies of HCV replication, we generated JFH1-based bicistronic luciferase reporter virus genomes. We found that RNA replication of the reporter construct was only slightly attenuated and that virus titers produced were only three- to fivefold lower compared to the parental virus, making these reporter viruses an ideal tool for quantitative analyses of HCV infections. To expand the scope of the system, we created two chimeric JFH1 luciferase reporter viruses with structural proteins from the Con1 (genotype 1b) and J6CF (genotype 2a) strains. Using these and the authentic JFH1 reporter viruses, we analyzed the early steps of the HCV life cycle. Our data show that the mode of virus entry is conserved between these isolates and involves CD81 as a key receptor for pH-dependent virus entry. Competition studies and time course experiments suggest that interactions of HCV with cell surface-resident glycosaminoglycans aid in efficient infection of Huh7 cells and that CD81 acts during a postattachment step. The reporter viruses described here should be instrumental for investigating the viral life cycle and for the development of HCV inhibitors.
Kaposi's Sarcoma-Associated Herpesvirus Lytic Gene ORF57 Is Essential for Infectious Virion Production
Authors: Han Zhao , Swaminathan Sankar 
Published: May 2006

ABSTRACT

The ORF57 gene of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a nuclear protein expressed during the lytic phase of KSHV replication. An ORF57 homolog is present in all known human herpesviruses and many animal herpesviruses. Many of these proteins have been demonstrated to have essential transcriptional and posttranscriptional regulatory functions. ORF57 enhances expression of reporter genes posttranscriptionally in vitro and may synergize with transcription factors to enhance gene transcription. However, the biologic role of ORF57 in KSHV replication has not been established. In this study, we demonstrate that ORF57 is essential for productive KSHV lytic replication by constructing a recombinant KSHV in which ORF57 expression has been specifically inactivated. The ORF57-null KSHV recombinant was unable to produce virion progeny or fully express several other lytic KSHV genes except when ORF57 was provided in
trans
. The Epstein-Barr virus (EBV) homolog of ORF57, SM, was unable to rescue lytic KSHV virion production, although EBV SM does enhance KSHV lytic gene expression from the ORF57-null mutant. Conversely, ORF57 did not rescue an SM-null recombinant EBV, indicating the existence of virus-specific functions for the ORF57 family of genes.
Extraintestinal Spread and Replication of a Homologous EC Rotavirus Strain and a Heterologous Rhesus Rotavirus in BALB/c Mice
Authors: Fenaux M. , Cuadras M. A. , Feng N. , Jaimes M. , Greenberg H. B. 
Published: May 2006

ABSTRACT

Although rotavirus infection has generally been felt to be restricted to the gastrointestinal tract, over the last two decades there have been sporadic reports of children with acute or fatal cases of rotavirus gastroenteritis testing positive for rotavirus antigen and/or nucleic acid in various extraintestinal locations such as serum, liver, kidney, bladder, testes, nasal secretions, cerebrospinal fluid, and the central nervous system. Recently, studies in animals and people have demonstrated that rotavirus antigenemia is a common event during natural infection. In this study, we extend these observations and compare the intestinal and extraintestinal spread of wild-type homologous murine rotavirus EC and a heterologous strain, rhesus rotavirus (RRV), in newborn mice. A strand-specific quantitative reverse transcription-PCR (ssQRT-PCR) assay was used to quantify the ability of different rotavirus strains to spread and replicate extraintestinally. Both strain EC and RRV were detected extraintestinally in the mesenteric lymph nodes (MLN), livers, lungs, blood, and kidneys. Extraintestinal replication, as measured by ssQRT-PCR, was most prominent in the MLN and occurred to a lesser degree in the livers, kidneys, and lungs. In the MLN, strain EC and RRV had similar (
P
< 0.05) RNA copy numbers, although EC was present at a 10,000-fold excess over RRV in the small intestine. Rotavirus nonstructural protein 4 (NSP4) and/or assembled triple-layered particles, indicated by immunostaining with the VP7 conformation-dependent monoclonal antibody 159, were detected in the MLN, lungs, and livers of EC- and RRV-inoculated mice, confirming the ssQRT-PCR findings. Infectious RRV was detected in the MLN in quantities exceeding the amount present in the small intestines or blood. The cells in the MLN that supported rotavirus replication included dendritic cells and potentially B cells and macrophages. These data indicate that extraintestinal spread and replication occurs commonly during homologous and some heterologous rotaviral infections; that the substantial host range restrictions for rhesus rotavirus, a heterologous strain present in the intestine, are not necessarily apparent at systemic sites; that the level and location of extraintestinal replication varies between strains; that replication can occur in several leukocytes subsets; and that extraintestinal replication is likely a part of the normal pathogenic sequence of homologous rotavirus infection.
Epitopes Expressed in Different Adenovirus Capsid Proteins Induce Different Levels of Epitope-Specific Immunity
Authors: Krause Anja , Joh Ju H. , Hackett Neil R. , Roelvink Peter W. , Bruder Joseph T. , Wickham Thomas J. , Kovesdi Imre , Crystal Ronald G. , Worgall Stefan 
Published: May 2006

ABSTRACTOn the basis of the concept that the capsid proteins of adenovirus (Ad) gene transfer vectors can be genetically manipulated to enhance the immunogenicity of Ad-based vaccines, the present study compared the antiantigen immunogenicity of Ad vectors with a common epitope of the hemagglutinin (HA) protein of the influenza A virus incorporated into the outer Ad capsid protein hexon, penton base, fiber knob, or protein IX. Incorporation of the same epitope into the different capsid proteins provided insights into the correlation between epitope position and antiepitope immunity. Following immunization of three different strains of mice (C57BL/6, BALB/c, and CBA) with either an equal number of Ad particles (resulting in a different total HA copy number) or different Ad particle numbers (to achieve the same HA copy number), the highest primary (immunoglobulin M [IgM]) and secondary (IgG) anti-HA humoral and cellular CD4 gamma interferon and interleukin-4 responses against HA were always achieved with the Ad vector carrying the HA epitope in fiber knob. These observations suggest that the immune response against an epitope inserted into Ad capsid proteins is not necessarily dependent on the capsid protein number and imply that the choice of incorporation site in Ad capsid proteins in their use as vaccines needs to be compared in vivo.
Regulation of the EBNA1 Epstein-Barr Virus Protein by Serine Phosphorylation and Arginine Methylation
Authors: Shire Kathy , Kapoor Priya , Jiang Ke , Hing Margaret Ng Thow , Sivachandran Nirojini , Nguyen Tin , Frappier Lori 
Published: May 2006

ABSTRACT
The Epstein-Barr virus (EBV) EBNA1 protein is important for the replication and mitotic segregation of EBV genomes in latently infected cells and also activates the transcription of some of the viral latency genes. A Gly-Arg-rich region between amino acids 325 and 376 is required for both the segregation and transcriptional activation functions of EBNA1. Here we show that this region is modified by both arginine methylation and serine phosphorylation. Mutagenesis of the four potentially phosphorylated serines in this region indicated that phosphorylation of multiple serines contributes to the efficient segregation of EBV-based plasmids by EBNA1, at least in part by increasing EBNA1 binding to hEBP2. EBNA1 was also found to bind the arginine methyltransferases PRMT1 and PRMT5. Multiple arginines in the 325-376 region were methylated in vitro by PRMT1 and PRMT5, as was an N-terminal Gly-Arg-rich region between amino acids 41 and 50. EBNA1 was also shown to be methylated in vivo, predominantly in the 325-376 region. Treatment of cells with a methylation inhibitor or down-regulation of PRMT1 altered EBNA1 localization, resulting in the formation of EBNA1 rings around the nucleoli. The results indicate that EBNA1 function is influenced by both serine phosphorylation and arginine methylation.
Self-esteem in a palliative care population
Authors: Babar Mahrukh , ul Haq Sheikh Moeen 
Published: May 2006

Objective. To study the effects of palliative care treatment in cancer patients, on their self-esteem. Design and setting. It was a cross-sectional study conducted at Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan (SKMCH & RC). Participants. A total of 60 referred cancer patients receiving palliative care were interviewed using the Mehrabian self-esteem scale (MSE). No follow-up was required. All the patients were over 16 years of age. The sample was not restricted to any one type of cancer. Since lack of education could be a contributing factor, only patients who had a minimum of an eighth-grade education were included in the study. Results. Four variables were studied: gender, age, diagnostic-related group, and performance status. Performance status was determined using the Eastern Cooperative Oncology Group Scale (ECOG). The only significant correlation was between self-esteem and performance status, with a p value of 0.04. Conclusion. We conclude that the patients who are functionally active (not disabled) have a higher level of self-esteem, as compared to those who are disabled. This is quite understandable, as the patients who are not dependent on others for their needs feel worthy, resulting in higher self-esteem. This was the first study of its kind done in Pakistan. We identified two limitations. First, the sample size was small. Second, although the Mehrabian self-esteem scale is a valid, reliable, and standardized scale, it was not standardized for the population of Pakistan.
Assessment of nutritional status and fluid deficits in advanced cancer
Authors: Sarhill Nabeel , Mahmoud Fade Aziz , Christie Richard , Tahir Adnan 
Published: May 2006

Malnutrition and cachexia are frequent manifestations of cancer and are major contributors to morbidity and mortality. The assessment of nutrition status in cancer patients can be easily accomplished. The first step is to record a complete medical history and to perform a thorough clinical examination to uncover signs of nutritional deficiency. Simple and inexpensive tests are available to assess the body composition, such as: anthropometric measurements, skinfold thickness, arm muscle circumference and area, and weight and body mass index (BMI). Biochemical measurements are also available, such as serum albumin, transferring, and prealbumin. Fluid deficit is divided into two categories based on pathophysiology (dehydration and volume depletion) and to three subtypes based on plasma sodium concentration (hyponatremic, hypernatremic, and isotonic). Dehydration (total water deficit, especially intracellular) is always hypernatremic, while volume depletion (intravascular water and sodium deficit) is either hyponatremic, hypernatremic, or isotonic. There are no clear clinical differences among the various categories, but a delay of capillary refill, tachycardia, and orthostatic hypotension is more common with volume depletion. Careful clinical assessment and laboratory tests, especially serum sodium, are the keystones for diagnosis and effective management. Bioelectrical impedance (BEI) is an easy way to assess both nutrition status and fluid deficits in advanced cancer and should be used more often than it currently is. This article reviews the subjective and objective methods of assessing fluid deficit and nutrition in advanced cancer.
Terminal restlessness as perceived by hospice professionals
Authors: Head Barbara , Faul Annatje 
Published: May 2006

Any hospice professional can identify the syndrome known as terminal restlessness, and all would agree that it is extremely distressing to patients as well as their families and care-givers. Often, caregivers cannot ameliorate the anguish many patients experience at life’s end. Many clinicians assert that the causes are physical resulting from medication toxicity, organ shutdown and the associated metabolic changes, pain, urinary or fecal retention, dyspnea and related hypoxia, and sepsis. Yet, many also credit psychosocial and spiritual distress as precipitating factors. The purposes of this study were twofold: to compare the perceptions of practicing hospice clinicians with the literature related to terminal restlessness, and to determine if their experience with terminal restlessness agreed with the components of the one established scale for terminal restlessness found in the literature. In general, the study findings corresponded to the literature in regards to frequency, definition, causes, and behavioral manifestations of terminal restlessness. The clinicians in the study supported the impact of psychosocial and spiritual causes of terminal restlessness and defined the phenomenon in terms of time period; emotional, physical, and spiritual distress; changes in consciousness; and increased activity. However, the study did not support the inclusion of impaired consciousness and withdrawal as comprised in the terminal restlessness scale.
A specialized hospice for dementia patients and their families
Authors: Brechling Brigid G. , Kuhn Dan 
Published: May 2006

This article reports the development of a small pilot program and briefly describes its activities. The growing number of dementia patients in American communities indicates a need to extend hospice services to these patients and their families. It is difficult to determine at present whether this need could be met more effectively by encouraging existing hospices to accept these patients or by establishing specialized programs such as this one. Research in this area is indicated, as well as the sharing of information among hospices providing care to other specialized groups — people with AIDS or terminally ill children for example. The Alzheimer's Family Care Hospice has provided services to eight terminally ill dementia patients and their families in a pilot project sponsored jointly by the Rush Alzheimer's Disease Center and the Chicago Area Chapter of the Alzheimer's Association. Another six patients did not meet admission criteria.