bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frequency of Sample Submission for Optimal Utilization of the Cell Culture Cytotoxicity Assay for Detection of
Clostridium difficile
Toxin
Authors: Borek Anita P. , Aird Deborah Z. , Carroll Karen C. 
Published: June 2005

ABSTRACT

We reviewed the results of repeated sample submissions within a 7-day time frame for
Clostridium difficile
toxin testing. A total of 2,940 samples were tested during a 3-month period using a cell culture cytotoxicity assay (CCCA). The results from all second samples (
n
= 1,101) were concordant with the original test result. In only two cases (0.8%;
n
= 247) was a third sample positive when the first two samples were negative. In this study, submission of multiple samples for CCCA did not increase detection of
Clostridium difficile
infection.
Shared Genotypes of
Achromobacter xylosoxidans
Strains Isolated from Patients at a Cystic Fibrosis Rehabilitation Center
Authors: Van daele Sabine , Verhelst Rita , Claeys Geert , Verschraegen Gerda , Franckx Hilde , Van Simaey Leen , de Ganck Catharine , De Baets Frans , Vaneechoutte Mario 
Published: June 2005

ABSTRACT

During a study examining transmission of
Pseudomonas aeruginosa
among 76 cystic fibrosis patients in a rehabilitation center, where patients stay in close contact during prolonged periods, several clusters of patients carrying genotypically identical
P. aeruginosa
, as well as two clusters of 4 and 10 patients, respectively, colonized with genotypically identical
Achromobacter xylosoxidans
strains, were discovered.
Disseminated Coinfection with
Actinomyces graevenitzii
and
Mycobacterium tuberculosis
: Case Report and Review of the Literature
Authors: Tietz Andreas , Aldridge Kenneth E. , Figueroa Julio E. 
Published: June 2005

ABSTRACT

We report the first case of disseminated infection with both
Actinomyces graevenitzii
and
Mycobacterium tuberculosis
and review the medical literature. Concomitant actinomycosis and tuberculosis is very rare. The potential of the facultatively aerobic, newly described
A. graevenitzii
for disseminated invasive infection needs to be evaluated.
Pyrrolidine Dithiocarbamate Reduces Coxsackievirus B3 Replication through Inhibition of the Ubiquitin-Proteasome Pathway
Authors: Si Xiaoning , McManus Bruce M. , Zhang Jingchun , Yuan Ji , Cheung Caroline , Esfandiarei Mitra , Suarez Agripina , Morgan Andrew , Luo Honglin 
Published: June 2005

ABSTRACTCoxsackievirus B3 (CVB3) is one of the most common pathogens for viral myocarditis. The lack of effective therapeutics for CVB3-caused viral diseases underscores the importance of searching for antiviral compounds. Pyrrolidine dithiocarbamate (PDTC) is an antioxidant and is recently reported to inhibit ubiquitin-proteasome-mediated proteolysis. Previous studies have shown that PDTC inhibits replication of rhinovirus, influenza virus, and poliovirus. In the present study, we report that PDTC is a potent inhibitor of CVB3. Coxsackievirus-infected HeLa cells treated with PDTC showed a significant reduction of CVB3 viral RNA synthesis, viral protein VP1 expression, and viral progeny release. Similar to previous observation that divalent ions mediate the function of PDTC, we further report that serum-containing copper and zinc are required for its antiviral activity. CVB3 infection resulted in massive generation of reactive oxygen species (ROS). Although PDTC alleviated ROS generation, the antiviral activity was unlikely dependent on its antioxidant effect because the potent antioxidant,N-acetyl-l-cysteine, failed to inhibit CVB3 replication. Consistent with previous reports that PDTC inhibits ubiquitin-proteasome-mediated protein degradation, we found that PDTC treatment led to the accumulation of several short-lived proteins in infected cells. We further provide evidence that the inhibitory effect of PDTC on protein degradation was not due to inhibition of proteasome activity but likely modulation of ubiquitination. Together with our previous findings that proteasome inhibition reduces CVB3 replication (H. Luo, J. Zhang, C. Cheung, A. Suarez, B. M. McManus, and D. Yang, Am. J. Pathol.163:381-385, 2003), results in this study suggest a strong antiviral effect of PDTC on coxsackievirus, likely through inhibition of the ubiquitin-proteasome pathway.
Hepatitis C Virus E2-CD81 Interaction Induces Hypermutation of the Immunoglobulin Gene in B Cells
Authors: Machida Keigo , Cheng Kevin T.-H. , Pavio Nicole , Sung Vicky M.-H. , Lai Michael M. C. 
Published: June 2005

ABSTRACTHepatitis C virus (HCV) is one of the leading causes of chronic liver diseases and B-lymphocyte proliferative disorders, including mixed cryoglobulinemia and B-cell lymphoma. It has been suggested that HCV infects human cells through the interaction of its envelope glycoprotein E2 with a tetraspanin molecule CD81, the putative viral receptor. Here, we show that the engagement of B cells by purified E2 induced double-strand DNA breaks specifically in the variable region of immunoglobulin (VH) gene locus, leading to hypermutation in theVHgenes of B cells. Other gene loci were not affected. Preincubation with the anti-CD81 monoclonal antibody blocked this effect. E2-CD81 interaction on B cells triggered the enhanced expression of activation-induced cytidine deaminase (AID) and also stimulated the production of tumor necrosis factor alpha. Knockdown of AID by the specific small interfering RNA blocked the E2-induced double-strand DNA breaks and hypermutation of theVHgene. These findings suggest that HCV infection, through E2-CD81 interaction, may modulate host's innate or adaptive immune response by activation of AID and hypermutation of immunoglobulin gene in B cells, leading to HCV-associated B-cell lymphoproliferative diseases.
Novel Nuclear Export Signal-Interacting Protein, NESI, Critical for the Assembly of Hepatitis Delta Virus
Authors: Wang Yun-Hsin , Chang Shin C. , Huang Cheng , Li Ya-Ping , Lee Chia-Huei , Chang Ming-Fu 
Published: June 2005

ABSTRACT

The process of host factor-mediated nucleocytoplasmic transport is critical for diverse cellular events in eukaryotes and the life cycle of viruses. We have previously identified a chromosome region maintenance 1-independent nuclear export signal (NES) at the C terminus of the large form of hepatitis delta antigen (HDAg), designated NES(HDAg-L) that is required for the assembly of hepatitis delta virus (HDV) (C.-H. Lee et al., J. Biol. Chem.
276:
8142-8148, 2001). To look for interacting proteins of the NES(HDAg-L), yeast two-hybrid screening was applied using the GAL4-binding domain fused to the NES(HDAg-L) as bait. Among the positive clones, one encodes a protein, designated NESI [NES(HDAg-L) interacting protein] that specifically interacted with the wild-type NES(HDAg-L) but not with the export/package-defective HDAg-L mutant, NES*(HDAg-L), in which Pro-205 has been replaced by Ala. Northern blot analysis revealed NESI as the gene product of a 1.9-kb endogenous mRNA transcript that is present predominantly in human liver tissue. NESI consists of 467 amino acid residues and bears a putative actin-binding site and a bipartite nuclear localization signal. Specific interaction between HDAg-L and NESI was further confirmed by coimmunoprecipitation and immunofluorescence staining. Overexpression of antisense NESI RNAs inhibited the expression of NESI and abolished HDAg-L-mediated nuclear export and assembly of HDV genomic RNA. These data indicate a critical role of NESI in the assembly of HDV through interaction with HDAg-L.
Characterization of a Previously Unidentified Viral Protein in Porcine Circovirus Type 2-Infected Cells and Its Role in Virus-Induced Apoptosis
Authors: Liu Jue , Chen Isabelle , Kwang Jimmy 
Published: June 2005

ABSTRACT
Porcine circovirus type 2 (PCV2) is the causative agent of postweaning multisystemic wasting syndrome in pigs. In this study, transcription and translation of a novel viral gene (termed ORF3 here) was detected during productive infection of PCV2 in PK15 cells. The results of infection with ORF3-deficient PCV2 by site-directed mutagenesis indicated that the protein is not essential for viral replication. To investigate the underlying mechanism of cell death caused by replication of PCV2, apoptosis characterized by chromosomal condensation and fragmentation, formation of apoptotic bodies, and significant increase in hypodiploids were detected in infected cells. We further demonstrated that PCV2-induced apoptosis required the activation of caspase-8 but not caspase-9. The activation of caspase-8 results in the activation of caspase-3 as shown by an increase in the cleavage of the caspase substrate in the infected cells. To determine whether ORF3 protein could trigger apoptosis, ORF3 as well as ORF1 and ORF2 genes were transiently expressed in PK15 and Cos-7 cells for apoptotic activity assay. Transfection of cells with the ORF3 alone induced apoptosis using a pathway similar to that described in the context of viral infection. This is further confirmed by a significant decrease in apoptotic activity of infected cells in the absence of the ORF3 expression, suggesting that the protein plays a major role in the induction of virus-induced apoptosis. Altogether, these results indicate that ORF3 is a novel PCV2 protein that is not essential for viral replication in cultured cells but is involved in PCV2-induced apoptosis by activating caspase-8 and caspase-3 pathways.
Seroprevalence and Genomic Divergence of Circulating Strains of Feline Immunodeficiency Virus among
Felidae
and
Hyaenidae
Species
Authors: Troyer Jennifer L. , Pecon-Slattery Jill , Roelke Melody E. , Johnson Warren , VandeWoude Sue , Vazquez-Salat Nuria , Brown Meredith , Frank Laurence , Woodroffe Rosie , Winterbach Christiaan , Winterbach Hanlie , Hemson Graham , Bush Mitch , Alexander Kathleen A. , Revilla Eloy , O'Brien Stephen J. 
Published: June 2005

ABSTRACT

Feline immunodeficiency virus (FIV) infects numerous wild and domestic feline species and is closely related to human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). Species-specific strains of FIV have been described for domestic cat (
Felis catus
), puma (
Puma concolor
), lion (
Panthera leo
), leopard (
Panthera pardus
), and Pallas' cat (
Otocolobus manul
). Here, we employ a three-antigen Western blot screening (domestic cat, puma, and lion FIV antigens) and PCR analysis to survey worldwide prevalence, distribution, and genomic differentiation of FIV based on 3,055 specimens from 35
Felidae
and 3
Hyaenidae
species. Although FIV infects a wide variety of host species, it is confirmed to be endemic in free-ranging populations of nine
Felidae
and one
Hyaenidae
species. These include the large African carnivores (lion, leopard, cheetah, and spotted hyena), where FIV is widely distributed in multiple populations; most of the South American felids (puma, jaguar, ocelot, margay, Geoffroy's cat, and tigrina), which maintain a lower FIV-positive level throughout their range; and two Asian species, the Pallas' cat, which has a species-specific strain of FIV, and the leopard cat, which has a domestic cat FIV strain in one population. Phylogenetic analysis of FIV proviral sequence demonstrates that most species for which FIV is endemic harbor monophyletic, genetically distinct species-specific FIV strains, suggesting that FIV transfer between cat species has occurred in the past but is quite infrequent today.
Characterization of
Hortulanus
Endogenous Murine Leukemia Virus, an Endogenous Provirus That Encodes an Infectious Murine Leukemia Virus of a Novel Subgroup
Authors: Tipper Christopher H. , Bencsics Craig E. , Coffin John M. 
Published: June 2005

ABSTRACT

Simple retroviruses present a unique opportunity for examining the host-virus relationship. Following exogenous infection and integration into the germ line, copies of these viruses can become fixed within the genome. The resulting endogenous proviral “fossils” represent a record of past retroviral infections and forms. Previous work in our laboratory has been directed at dissecting the extensive nonecotropic murine leukemia virus content of the mouse genome. One such provirus,
hortulanus
endogenous murine leukemia virus (HEMV), found in a single copy in the genome of
Mus spicilegus
, was remarkable for characteristics that suggested that it was ancient and related to the hypothetical common ancestor of murine leukemia viruses (MLVs) and other gammaretroviral species. In the present study, we have analyzed its functional properties. Transfection of a molecular clone of the HEMV provirus into mouse-derived cell lines revealed that it is replication competent. Furthermore, host range and interference studies revealed a strictly ecotropic host range and the use of a receptor distinct from those used by other classical MLVs. The identity of nucleotide sequence of the long terminal repeats (LTRs) further suggested that HEMV is a relatively recent insertion into the
M. spicilegus
genome at the distal end of chromosome 7. Although unique to
M. spicilegus
, its presence in a homozygous state in three individuals obtained from different regions implies that it has been present long enough to become fixed in this species. Exhaustive phylogenetic analysis of all regions of the HEMV genome supported the previously assigned ancestral position of HEMV relative to other MLV-related viruses. Thus, HEMV is a relatively recent introduction into the
Mus
germ line but is representative of a relatively ancestral MLV group.
Wild-Type-Like Viral Replication Potential of Human Immunodeficiency Virus Type 1 Envelope Mutants Lacking Palmitoylation Signals
Authors: Chan Woan-Eng , Lin Hui-Hua , Chen Steve S.-L. 
Published: June 2005

ABSTRACT

Palmitoylation of the cytoplasmic domain of the human immunodeficiency type virus type 1 (HIV-1) envelope (Env) transmembrane protein, gp41, has been implicated in Env targeting to detergent-resistant lipid rafts, Env incorporation into the virus, and viral infectivity. In contrast, we provide evidence here to show that HIV-1 infectivity, Env targeting to lipid rafts, and Env incorporation into the virus are independent of cytoplasmic tail palmitoylation. The T-cell (T)-tropic HXB2-based virus, which utilizes CXCR4 as the entry coreceptor, carrying a Cys-to-Ser mutation at residue 764 or 837 or at both replicated with wild-type (WT) virus replication kinetics in CD4
+
T cells. The properties of Env expression, precursor processing, cell surface expression, and Env incorporation of these three mutant viruses were normal compared to those of the WT virus. These three mutant Env proteins all effectively mediated one-cycle virus infection. When the Cys residues were replaced by Ala residues, all single and double mutants still retained the phenotypes of infectivity, Env incorporation, and lipid raft localization of the WT Env. When Cys-to-Ala substitutions were introduced into the macrophage (M)-tropic ConB virus, which utilizes CCR5 as the coreceptor, these mutations did not affect the replication potential, Env phenotypes, lipid raft targeting, or Env assembly into the virus of the WT Env. These T- and M-tropic mutants also productively replicated in human primary CD4
+
T cells. Moreover, mutations at both Cys residues significantly reduced the level of palmitoylation of the Env. Our results together support the notion that palmitoylation of the cytoplasmic tail of the HIV-1 Env is not essential for the HIV-1 virus life cycle.
Attenuation of Recombinant Yellow Fever 17D Viruses Expressing Foreign Protein Epitopes at the Surface
Authors: Bonaldo Myrna C. , Garratt Richard C. , Marchevsky Renato S. , Coutinho Evandro S. F. , Jabor Alfredo V. , Almeida Luís F. C. , Yamamura Anna M. Y. , Duarte Adriana S. , Oliveira Prisciliana J. , Lizeu Jackeline O. P. , Camacho Luiz A. B. , Freire Marcos S. , Galler Ricardo 
Published: June 2005

ABSTRACT

The yellow fever (YF) 17D vaccine is a live attenuated virus. Three-dimensional (3D) homology modeling of the E protein structure from YF 17D virus and its comparison with that from tick-borne encephalitis virus revealed that it is possible to accommodate inserts of different sizes and amino acid compositions in the flavivirus E protein
fg
loop. This is consistent with the 3D structures of both the dimeric and trimeric forms in which the
fg
loop lies exposed to solvents. We demonstrate here that YF 17D viruses bearing foreign humoral (17D/8) and T-cell (17D/13) epitopes, which vary in sequence and length, displayed growth restriction. It is hypothesized that interference with the dimer-trimer transition and with the formation of a ring of such trimers in order to allow fusion compromises the capability of the E protein to induce fusion of viral and endosomal membranes, and a slower rate of fusion may delay the extent of virus production. This would account for the lower levels of replication in cultured cells and of viremia in monkeys, as well as for the more attenuated phenotype of the recombinant viruses in monkeys. Testing of both recombinant viruses (17D/8 and 17D/13) for monkey neurovirulence also suggests that insertion at the 17D E protein
fg
loop does not compromise the attenuated phenotype of YF 17D virus, further confirming the potential use of this site for the development of new live attenuated 17D virus-based vaccines.
Role of Papillomavirus E1 Initiator Dimerization in DNA Replication
Authors: Schuck Stephen , Stenlund Arne 
Published: June 2005

ABSTRACT
Viral initiator proteins are polypeptides that form oligomeric complexes on the origin of DNA replication (ori). These complexes carry out a multitude of functions related to initiation of DNA replication, and although many of these functions have been characterized biochemically, little is understood about how the complexes are assembled. Here we demonstrate that loss of one particular interaction, the dimerization between E1 DNA binding domains, has a severe effect on DNA replication in vivo but has surprisingly modest effects on most individual biochemical activities in vitro. We conclude that the dimer interaction is primarily required for initial recognition of ori.
In Vitro Assembly of PB2 with a PB1-PA Dimer Supports a New Model of Assembly of Influenza A Virus Polymerase Subunits into a Functional Trimeric Complex
Authors: Deng Tao , Sharps Jane , Fodor Ervin , Brownlee George G. 
Published: June 2005

ABSTRACT
Influenza virus RNA-dependent RNA polymerase is a heterotrimeric complex of PB1, PB2, and PA. We show that the individually expressed PB2 subunit can be assembled with the coexpressed PB1-PA dimer in vitro into a transcriptionally active complex. Furthermore, we demonstrate that a model viral RNA promoter can bind to the PB1-PA dimer prior to assembly with PB2. Our results are consistent with a recently proposed model for the sequential assembly of viral RNA polymerase complex in which the PB1-PA dimeric complex and the PB2 monomer are transported into the nucleus separately and then assembled in the nucleus.
The TUBB1 Q43P functional polymorphism reduces the risk of cardiovascular disease in men by modulating platelet function and structure
Authors: Freson Kathleen , De Vos Rita , Wittevrongel Christine , Thys Chantal , Defoor Johan , Vanhees Luc , Vermylen Jos , Peerlinck Kathelijne , Van Geet Chris 
Published: June 2005

AbstractThe discoid form of platelets is maintained by a marginal band of tightly coiled microtubules. β1-tubulin is the major isoform within platelet and megakaryocyte microtubules. In 24.2% of 33 unrelated inherited macrothrombocytopenia patients and in 10.6% of 272 subjects of a healthy population a P for Q substitution in β1-tubulin was found in the highly conserved residue 43. Heterozygous carriers of the Q43P variant showed a reduced platelet protein β1-tubulin expression. Transfection of green fluorescent protein (GFP)-tagged Q43P β1-tubulin in megakaryocytic MEG01 cells resulted in a disturbed tubulin organization. Electron microscopy revealed enlarged spherocytic platelets with a disturbed marginal band and organelle-free zones. In addition, platelets with the Q43P β1-tubulin variant had reduced adenosine triphosphate (ATP) secretion, thrombin receptor activating peptide (TRAP)-induced aggregation and collagen adhesion. The prevalence of the Q43P β1-tubulin variant was also 2 times higher (odds ratio, [OR] = 2.1;95% confidence interval [CI], 1.22-3.59) among control subjects than among patients with cardiovascular disease (10.4% versus 5.2%, P &lt; .001). By analyzing this protective factor in men and women separately, this association was only found in men. This study thus presents the functional consequences of the platelet Q43P β1-tubulin substitution that is frequent in the healthy population and may protect men against arterial thrombosis.
Pregnancy-induced obsessive compulsive disorder: a case report
Authors: Kalra Harish , Tandon Rajul , Trivedi Jitendra kumar , Janca Aleksandar 
Published: June 2005

Abstract
Pregnancy is a well-recognised risk factor in precipitating obsessive-compulsive disorder. We present and discuss a case with the onset of obsessive-compulsive disorder in the fourth month of gestation, which fully recovered two weeks after delivery. The phenomenology of the observed disorder was similar to earlier reports of obsessive-compulsive disorder in pregnancy, i.e. the obsessions and compulsions were predominantly related to the concern of contaminating the foetus resulting in washing compulsions. Despite the initial success with anti-obsessional drugs, the patient stopped the medication in the last month of gestation. Nevertheless, she fully recovered two weeks after the delivery without any psychiatric intervention. There were no obsessive-compulsive symptoms at one-year follow up. The possible mechanisms involved in the aetiology of this case, and future research directions in understanding the role of pregnancy in OCD are discussed.
Anticoagulation Monitoring Part 2: Unfractionated Heparin and Low-Molecular-Weight Heparin
Authors: Spinler Sarah A , Wittkowsky Ann K , Nutescu Edith A , Smythe Maureen A 
Published: June 2005

OBJECTIVE To review the availability, mechanisms, limitations, and clinical application of point-of-care (POC) devices used in monitoring anticoagulation with unfractionated heparin (UFH) and low-molecular-weight heparins (LMWHs). DATA SOURCES Articles were identified through a MEDLINE search (1966–August 2004), device manufacturer Web sites, additional references listed in articles and Web sites, and abstracts from scientific meetings. STUDY SELECTION AND DATA EXTRACTION English-language literature from clinical trials was reviewed to evaluate the accuracy, reliability, and clinical application of POC monitoring devices. DATA SYNTHESIS The activated partial thromboplastin time (aPTT) and activated clotting time (ACT) are common tests for monitoring anticoagulation with UFH. Multiple devices are available for POC aPTT, ACT, and heparin concentration testing. The aPTT therapeutic range for UFH will vary depending upon the reagent and instrument employed. Although recommended by the American College of Chest Physicians Seventh Conference on Antithrombotic and Thrombolytic Therapy, establishing a heparin concentration–derived therapeutic range for UFH is rarely performed. Additional research evaluating anti-factor Xa monitoring of LMWHs using POC testing is necessary. CONCLUSIONS Multiple POC devices are available to monitor anticoagulation with UFH. For each test, there is some variability in results between devices and between reagents used in the same device. Despite these limitations, POC anticoagulation monitoring of UFH using aPTT and, more often, ACT is common in clinical practice, particularly when evaluating anticoagulation associated with interventional cardiology procedures and cardiopulmonary bypass surgery.