bluuebunny/crossref_metadata_2025 huggingface dataset:
Response Prediction and Treatment Tailoring for Chronic Hepatitis C Virus Genotype 1 Infection
Authors: Lindh Magnus , Alestig Erik , Arnholm Birgitta , Eilard Anders , Hellstrand Kristoffer , Lagging Martin , Wahlberg Thomas , Wejstål Rune , Westin Johan , Norkrans Gunnar
Published: June 2007

We monitored early viral response during the treatment of hepatitis C virus (HCV) infection with the aim of identifying predictors of treatment outcome. We studied 53 patients with genotype 1 infection who received 180 μg/week pegylated interferon alfa-2a and 1,000 or 1,200 mg/day ribavirin depending on body weight and serially assessed HCV RNA in serum, using the Cobas TaqMan assay. Thirty-one patients (58%) achieved sustained viral response (SVR). SVR was obtained in 100% (10/10) of patients with pretreatment viremia concentrations below 400,000 IU/ml, in 100% (14/14) of patients with more than 1.5 log reduction of HCV RNA after 4 days of treatment, and in 95% (22/23) of patients with a rate of decline in viremia higher than 0.70 log units/week during the second phase. Non-SVR was seen in all patients with a second-phase decline rate lower than 0.35 log units/week. Patients with slopes between 0.50 and 0.80 log units/week achieved SVR (4/4) unless the treatment dose was modified (3/3). We conclude that the second-phase slope appears to be an accurate and useful predictor of treatment response. On the basis of these findings, we propose a model of tailored treatment which takes into account the second-phase slope and the amount of HCV RNA after 21 days of treatment.
Quality Control of Direct Molecular Diagnostics for Methicillin-Resistant
Staphylococcus aureus
Authors: van Belkum Alex , Niesters Hubert G. M. , MacKay William G. , van Leeuwen Willem B.
Published: June 2007

Ten samples containing various amounts of methicillin-resistant
Staphylococcus aureus
(MRSA), methicillin-susceptible
S. aureus
, methicillin-resistant
Staphylococcus epidermidis
(MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing 10
2
to 10
3
MRSA cells were frequently reported to be negative. MRSE samples were scored as negative by all commercial tests but by only two out of three in-house tests.
Molecular Typing of
Aspergillus terreus
Isolates Collected in Houston, Texas, and Innsbruck, Austria: Evidence of Great Genetic Diversity
Authors: Lass-Flörl Cornelia , Grif Katharina , Kontoyiannis Dimitrios P.
Published: June 2007

Aspergillus terreus
isolates collected from patients at The M. D. Anderson Cancer Center in Houston, TX, and at The University Hospital of Innsbruck, Austria, were analyzed using random amplification of polymorphic DNA-PCR with three different primers. No strain similarity in either institution was detected, indicating great genetic diversity of
A. terreus
.
Shedding and Reversion of Oral Polio Vaccine Type 3 in Mexican Vaccinees: Comparison of Mutant Analysis by PCR and Enzyme Cleavage to a Real-Time PCR Assay
Authors: Gnanashanmugam Devasena , Falkovitz-Halpern Meira S. , Dodge Anthony , Fang Melanie , Wong Lisa J. , Esparza Melissa , Hammon Rebecca , Rivas-Merelles Enrique E. , Santos Jose I. , Maldonado Yvonne
Published: June 2007

A uracil-to-cytosine mutation at nucleotide position 472 of oral poliovirus vaccine type 3 (OPV3) contributes to the development of vaccine-associated paralytic poliomyelitis (VAPP). To analyze OPV3 shedding patterns, we previously used the multistep method of mutant analysis by PCR and enzyme cleavage (MAPREC). This involves conventional reverse transcription-PCR to detect OPV3, followed by a restriction digest to quantify position 472 reversion. Real-time PCR detects and quantifies nucleic acid as PCR occurs and avoids postreaction processing. The goal of this study was to compare a real-time PCR method to MAPREC. Seventy-three stool samples from Mexican OPV recipients underwent the reverse transcription-PCR step of MAPREC and real-time PCR. Real-time PCR identified 23% more OPV3-positive samples than conventional reverse transcription-PCR. When reversion was compared, the revertant proportion (RP), defined as the percentage of revertants in a sample, differed by ≤10% in 21/25 (84%) samples. The four samples differing by >10% were obtained within 5 days of OPV administration. The real-time PCR assay identified samples with an RP of ≥85% with 94% sensitivity and 86% specificity compared to MAPREC. The mean difference in RP between the two methods was 3.6% (95% confidence interval, −0.3 to 7.5%). Real-time PCR methods reliably detect OPV3, and reversion estimates correlate more consistently with MAPREC when OPV3 reversion rates are high. Detecting VAPP-related mutations by real-time PCR is rapid and efficient and can be useful in monitoring ongoing global polio eradication efforts.
Role of Human Immunodeficiency Virus (HIV)-Specific T-Cell Immunity in Control of Dual HIV-1 and HIV-2 Infection
Authors: Zheng Natalie N. , McElrath M. Juliana , Sow Papa-Salif , Hawes Stephen E. , Diallo-Agne Habibatou , Stern Joshua E. , Li Fusheng , Mesher Andrew L. , Robinson Akeliah D. , Gottlieb Geoffrey S. , Huang Yunda , Kiviat Nancy B.
Published: June 2007

Progressive immune dysfunction and AIDS develop in most cases of human immunodeficiency virus type 1 (HIV-1) infection but in only 25 to 30% of persons with HIV-2 infection. However, the natural history and immunologic responses of individuals with dual HIV-1 and HIV-2 infection are largely undefined. Based on our previous findings, we hypothesized that among patients with dual infection the control of HIV-1 is associated with the ability to respond to HIV-2 Gag epitopes and to maintain HIV-specific CD4+T-cell responses. To test this, we compared the HIV-specific ex vivo IFN-γ enzyme-linked immunospot (ELISPOT) assay responses of 19 dually infected individuals to those of persons infected with HIV-1 or HIV-2 only. Further, we assessed the functional profile of HIV Gag-specific CD4+and CD8+T cells from nine HIV dually infected patients by using a multicolor intracellular cytokine staining assay. As determined by ELISPOT assay, the magnitude and frequency of IFN-γ-secreting T-cell responses to gene products of HIV-1 were higher than those to gene products of HIV-2 (2.64 versus 1.53 log10IFN-γ spot-forming cells/106cells [90% versus 63%, respectively].) Further, HIV-1 Env-, Gag-, and Nef- and HIV-2 Gag-specific responses were common; HIV-2 Nef-specific responses were rare. HIV-specific CD4+T helper responses were detected in nine of nine dually infected subjects, with the majority of these T cells producing gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and, to a lesser extent, interleukin-2. The HIV-1 plasma viral load was inversely correlated with HIV-2 Gag-specific IFN-γ-/TNF-α-secreting CD4+and HIV-2 Gag-specific IFN-γ-secreting CD8+T cells. In conclusion, the T-cell memory responses associated with containment of single HIV-1 and HIV-2 infection play a similar significant role in the immune control of dual HIV-1 and HIV-2 infection.
A New E6/P63 Pathway, Together with a Strong E7/E2F Mitotic Pathway, Modulates the Transcriptome in Cervical Cancer Cells
Authors: Teissier Sébastien , Ben Khalifa Youcef , Mori Marcella , Pautier Patricia , Desaintes Christian , Thierry Françoise
Published: June 2007

Cervical carcinoma is associated with certain types of human papillomaviruses expressing the E6 and E7 oncogenes, which are involved in carcinogenesis through their interactions with the p53 and pRB pathways, respectively. A critical event on the path to malignant transformation is often manifested by the loss of expression of the viral E2 transcription factor due to the integration into the host genome of the viral DNA. Using microarrays, we have previously shown that reintroduction of a functional E2 in the HeLa cervical carcinoma cell line activates a cluster of p53 target genes while at the same time severely repressing a group of E2F target genes. In the present study, using new high-density microarrays containing more than 22,000 human cDNA sequences, we identified a novel p63 pathway among E2-activated genes and 38 new mitotic genes repressed by E2. We then sought to determine the pathways through which these genes were modulated and used an approach that relies on small interfering RNA to demonstrate that the p63 target genes were activated through silencing of the E6/E6AP pathway while the mitotic genes were mainly repressed through E7 silencing. Importantly, a subset of the mitotic genes was shown to be significantly induced in biopsies of stage IV cervical cancers, which points to a prominent E7 pathway in cervical carcinoma.
Arenavirus Z-Glycoprotein Association Requires Z Myristoylation but Not Functional RING or Late Domains
Authors: Capul Althea A. , Perez Mar , Burke Emily , Kunz Stefan , Buchmeier Michael J. , de la Torre Juan C.
Published: June 2007

Generation of infectious arenavirus-like particles requires the virus RING finger Z protein and surface glycoprotein precursor (GPC) and the correct processing of GPC into GP1, GP2, and a stable signal peptide (SSP). Z is the driving force of arenavirus budding, whereas the GP complex (GPc), consisting of hetero-oligomers of SSP, GP1, and GP2, forms the viral envelope spikes that mediate receptor recognition and cell entry. Based on the roles played by Z and GP in the arenavirus life cycle, we hypothesized that Z and the GPc should interact in a manner required for virion formation. Here, using confocal microscopy and coimmunoprecipitation assays, we provide evidence for subcellular colocalization and biochemical interaction, respectively, of Z and the GPc. Our results from mutation-function analysis reveal that Z myristoylation, but not the Z late (L) or RING domain, is required for Z-GPc interaction. Moreover, Z interacted directly with SSP in the absence of other components of the GPc. We obtained similar results with Z and GPC from the prototypical arenavirus lymphocytic choriomeningitis virus and the hemorrhagic fever arenavirus Lassa fever virus.
Cytokine and Antibody Responses in Gnotobiotic Pigs after Infection with Human Norovirus Genogroup II.4 (HS66 Strain)
Authors: Souza M. , Cheetham S. M. , Azevedo M. S. P. , Costantini V. , Saif L. J.
Published: June 2007

A human norovirus genogroup II.4 strain HS66 (HuNoV-HS66) infects and causes mild diarrhea in gnotobiotic (Gn) pigs (S. Cheetham, M. Souza, T. Meulia, S. Grimes, M. G. Han, and L. J. Saif, J. Virol. 80:10372-10381, 2006). In this study we evaluated systemic and intestinal humoral and cellular immune responses to HuNoV-HS66 in orally inoculated pigs. Antibodies and type I interferon (IFN-I or IFN-α), proinflammatory interleukin-6 (IL-6), Th1 (IL-12 and IFN-γ), Th2 (IL-4), and Th2/regulatory T ([Treg] IL-10) cytokine profiles in serum and intestinal contents (IC) of the HuNoV-HS66-inoculated pigs and controls were assessed by enzyme-linked immunosorbent assay at selected postinoculation days (0 to 28). Using an enzyme-linked immunospot assay, we evaluated immunoglobulin M (IgM), IgA, and IgG antibody-secreting cells (ASC) and cytokine-secreting cells (CSC) in intestine, spleen, and blood. In the HuNoV-inoculated pigs, antibody titers in serum and IC were generally low, and 65% seroconverted. Pigs with higher diarrhea scores were more likely to seroconvert and developed higher intestinal IgA and IgG antibody titers. The numbers of IgA and IgG ASC were higher systemically than in the gut. In serum, HuNoV induced persistently higher Th1 (low transient IFN-γ and high IL-12) than the other cytokines, but also low Th2 (IL-4) and Th2/Treg(IL-10) levels; low, transient proinflammatory (IL-6) cytokines; and, notably, a delayed IFN-α response. In contrast, intestinal innate (IFN-α early and late) and Th1 (IL-12 late) cytokines were significantly elevated postinfection. HuNoV-HS66 also elicited higher numbers of Th1 (IL-12 and IFN-γ) CSC than Th2 (IL-4) and proinflammatory (IL-6) CSC, with the latter responses low in blood and intestine, reflecting low intestinal inflammation in the absence of gut lesions. These data provide insights into the kinetics of cytokine secretion in serum and IC of HuNoV-inoculated Gn pigs and new information on intestinal humoral and cellular immune responses to HuNoV that are difficult to assess in human volunteers.
Vaccinia Virus Entry, Exit, and Interaction with Differentiated Human Airway Epithelia
Authors: Vermeer Paola D. , McHugh Julia , Rokhlina Tatiana , Vermeer Daniel W. , Zabner Joseph , Welsh Michael J.
Published: June 2007

Variola virus, the causative agent of smallpox, enters and exits the host via the respiratory route. To better understand the pathogenesis of poxvirus infection and its interaction with respiratory epithelia, we used vaccinia virus and examined its interaction with primary cultures of well-differentiated human airway epithelia. We found that vaccinia virus preferentially infected the epithelia through the basolateral membrane and released viral progeny across the apical membrane. Despite infection and virus production, epithelia retained tight junctions, transepithelial electrical conductance, and a steep transepithelial concentration gradient of virus, indicating integrity of the epithelial barrier. In fact, during the first four days of infection, epithelial height and cell number increased. These morphological changes and maintenance of epithelial integrity required vaccinia virus growth factor, which was released basolaterally, where it activated epidermal growth factor 1 receptors. These data suggest a complex interaction between the virus and differentiated airway epithelia; the virus preferentially enters the cells basolaterally, exits apically, and maintains epithelial integrity by stimulating growth factor receptors.
Proteomics Analysis of
Helicoverpa armigera
Single Nucleocapsid Nucleopolyhedrovirus Identified Two New Occlusion-Derived Virus-Associated Proteins, HA44 and HA100
Authors: Deng Fei , Wang Ranran , Fang Minggang , Jiang Yue , Xu Xushi , Wang Hanzhong , Chen Xinwen , Arif Basil M. , Guo Lin , Wang Hualin , Hu Zhihong
Published: June 2007

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry were used to analyze the structural proteins of the occlusion-derived virus (ODV) of
Helicoverpa armigera
single nucleocapsid nucleopolyhedrovirus (HearNPV), a group II NPV. Twenty-three structural proteins of HearNPV ODV were identified, 21 of which have been reported previously as structural proteins or ODV-associated proteins in other baculoviruses. These include polyhedrin, P78/83, P49, ODV-E18, ODV-EC27, ODV-E56, P74, LEF-3, HA66 (AC66), DNA polymerase, GP41, VP39, P33, ODV-E25, helicase, P6.9, ODV/BV-C42, VP80, ODV-EC43, ODV-E66, and PIF-1. Two proteins encoded by HearNPV ORF44 (
ha44
) and ORF100 (
ha100
) were discovered as ODV-associated proteins for the first time.
ha44
encodes a protein of 378 aa with a predicted mass of 42.8 kDa.
ha100
encodes a protein of 510 aa with a predicted mass of 58.1 kDa and is a homologue of the gene for poly(ADP-ribose) glycohydrolase (
parg
). Western blot analysis and immunoelectron microscopy confirmed that HA44 is associated with the nucleocapsid and HA100 is associated with both the nucleocapsid and the envelope of HearNPV ODV. HA44 is conserved in group II NPVs and granuloviruses but does not exist in group I NPVs, while HA100 is conserved only in group II NPVs.
Relevance of the Interaction between Alphaherpesvirus UL3.5 and UL48 Proteins for Virion Maturation and Neuroinvasion
Authors: Fuchs Walter , Granzow Harald , Klupp Barbara G. , Karger Axel , Michael Kathrin , Maresch Christina , Klopfleisch Robert , Mettenleiter Thomas C.
Published: June 2007

The UL3.5 and UL48 genes, which are conserved in most alphaherpesvirus genomes, are important for maturation of pseudorabies virus (PrV) particles in the cytoplasm of infected cells (W. Fuchs, B. G. Klupp, H. J. Rziha, and T. C. Mettenleiter, J. Virol. 70:3517-3527, 1996; W. Fuchs, H. Granzow, B. G. Klupp, M. Kopp and T. C. Mettenleiter, J. Virol. 76:6729-6742, 2002). In bovine herpesvirus 1 (BoHV-1), the homologous gene products pUL3.5 and pUL48 have been demonstrated to interact physically (N. Lam and G. Letchworth, J. Virol. 74:2876-2884, 2000). Moreover, BoHV-1 pUL3.5 partially complemented a pUL3.5 defect in PrV (W. Fuchs, H. Granzow, and T. C. Mettenleiter, J. Virol. 71:8886-8892, 1997). By using coimmunoprecipitation and yeast two-hybrid studies, we observed a similar interaction between pUL3.5 and pUL48 of PrV, as well as a heterologous interaction between the PrV and BoHV-1 gene products. The relevant domain could be confined to the first 43 amino acids of PrV pUL3.5. Unlike its BoHV-1 homologue, PrV pUL3.5 is processed by proteolytic cleavage, and only an abundant 14-kDa fragment consisting of amino acids 1 to ≥116 could be detected by peptide mass fingerprint analysis of purified wild-type PrV particles, which also contain the pUL48 tegument component. To determine the biological relevance of the protein-protein interaction, pUL3.5-, pUL48-, and double-negative PrV mutants were analyzed in parallel. All deletion mutants were replication competent but exhibited significantly reduced plaque sizes and virus titers in cultured rabbit kidney cells compared to wild-type and rescued viruses, which correlated with a delayed neuroinvasion in intranasally infected mice. Remarkably, the defects of the double-negative mutant were similar to those of pUL48-negative virus. Electron microscopy of cells infected with either deletion mutant revealed the retention of naked nucleocapsids in the cytoplasm and the absence of mature virus particles. In summary, our studies for the first time demonstrate the relevance of the pUL3.5-pUL48 interaction for secondary envelopment of an alphaherpesvirus, give a molecular basis for the observed
trans
-complementation between the PrV and BHV-1 pUL3.5 homologs, yield conclusive evidence for the incorporation of a proteolytically processed pUL3.5 into PrV virions, and demonstrate the importance of both proteins for neuroinvasion and neurovirulence of PrV.
Enterocyte Proliferation and Intestinal Hyperplasia Induced by Simian Virus 40 T Antigen Require a Functional J Domain
Authors: Rathi Abhilasha V. , Sáenz Robles M. Teresa , Pipas James M.
Published: June 2007

Transgenic mice expressing the simian virus 40 large T antigen (TAg) in enterocytes develop intestinal hyperplasia that progresses to dysplasia with age. This induction requires TAg action on the retinoblastoma (Rb) family of tumor suppressors and is independent of the p53 pathway. In cell culture systems, the inactivation of Rb proteins requires both a J domain in TAg that interacts with hsc70 and an LXCXE motif that directs association with Rb proteins. Together these elements are sufficient to release E2Fs from their association with Rb family members. We have generated transgenic mice that express a J domain mutant (D44N) in villus enterocytes. In contrast to wild-type TAg, the D44N mutant is unable to induce enterocyte proliferation. Histological and morphological examination revealed that mice expressing the J domain mutant have normal intestines without loss of growth control. Unlike mice expressing wild-type TAg, mice expressing D44N do not reduce the protein levels of p130 and are also unable to dissociate p130-E2F DNA binding complexes. Furthermore, mice expressing D44N in a null p130 background are still unable to develop hyperplasia. These studies demonstrate that the ectopic proliferation of enterocytes by TAg requires a functional J domain and suggest that the J domain is necessary to inactivate all three pRb family members.
The C Terminus of Hepatitis C Virus NS4A Encodes an Electrostatic Switch That Regulates NS5A Hyperphosphorylation and Viral Replication
Authors: Lindenbach Brett D. , Prágai Béla M. , Montserret Roland , Beran Rudolf K. F. , Pyle Anna M. , Penin François , Rice Charles M.
Published: June 2007

Hepatitis C virus (HCV) nonstructural protein 4A (NS4A) is only 54 amino acids (aa) in length, yet it is a key regulator of the essential serine protease and RNA helicase activities of the NS3-4A complex, as well as a determinant of NS5A phosphorylation. Here we examine the structure and function of the C-terminal acidic region of NS4A through site-directed mutagenesis of a Con1 subgenomic replicon and through biophysical characterization of a synthetic peptide corresponding to this region. Our genetic studies revealed that in 8 of the 15 C-terminal residues of NS4A, individual Ala substitutions or charge reversal substitutions led to severe replication phenotypes, as well as decreased NS5A hyperphosphorylation. By selecting for replication-competent mutants, several second-site changes in NS3 were identified and shown to suppress these defects in replication and NS5A hyperphosphorylation. Circular-dichroism spectroscopy and nuclear magnetic resonance spectroscopy on a peptide corresponding to the C-terminal 19 aa of NS4A revealed that this region can adopt an alpha-helical conformation, but that this folding requires neutralization of a cluster of acidic residues. Taken together, these data suggest that the C terminus of NS4A acts as a dynamic regulator of NS3-4A interaction, NS5A hyperphosphorylation, and HCV replicase activity.
Structural Features of the Scaffold Interaction Domain at the N Terminus of the Major Capsid Protein (VP5) of Herpes Simplex Virus Type 1
Authors: Huang Eugene , Perkins Edward M. , Desai Prashant
Published: June 2007

Protein-protein interactions drive the assembly of the herpes simplex virus type 1 capsid. A key interaction occurs between the C terminus of the scaffold protein and the N terminus of the major capsid protein (VP5). Results from alanine-scanning mutagenesis of hydrophobic residues in the N terminus of VP5 revealed seven residues (I27, L35, F39, L58, L65, L67, and L71) that reside in two predicted alpha helices (helix 122-42and helix 258-72) that are important for this bimolecular interaction. The goal of the present study was to further characterize the VP5 scaffold interaction domain (SID). Amino acids at the seven positions were replaced with L, M, V or P (I27); I, M, V, or P (L35, L58, L65, L67, and L71); and H, W, Y, or L (F39). Replacement with a hydrophobic side chain did not affect the interaction with scaffold protein in yeast cells or the ability of a virus specifying the mutation from replicating in cells. The mutation to the proline side chain abolished the interaction in all cases and was lethal for virus replication. Mutant viruses with proline substitutions in helix 122-42at positions 27 and 35 assembled large open capsid shells that did not attain closure. Proline substitutions in helix 258-72at either position 59, 65, or 67 abolished the accumulation of VP5 protein, and, at 58 and 71, although VP5 did accumulate, capsid shells were not assembled. Thus, the second SID, SID2, is highly structured, and this alpha helix (helix 258-72) is likely involved in capsomere-capsomere interactions during shell accretion. Conserved glycine G59 in helix 258-72was also mutated. G59 may act as a flexible “hinge” in helix 258-72because decreasing the movement of this side chain by replacement with valine impaired capsid assembly. Thus, the N terminus of VP5 and the alpha helices embedded in this domain, as in the capsid shell proteins of some double-stranded DNA phages, are a key regulator of shell accretion and stabilization.
Expression and Characterization of a Minimal Hepatitis C Virus Glycoprotein E2 Core Domain That Retains CD81 Binding
Authors: McCaffrey Kathleen , Boo Irene , Poumbourios Pantelis , Drummer Heidi E.
Published: June 2007

The hepatitis C virus glycoprotein E2 receptor-binding domain is encompassed by amino acids 384 to 661 (E2661) and contains two hypervariable sequences, HVR1 and HVR2. E2 sequence comparisons revealed a third variable region, located between residues 570 and 580, that varies widely between genotypes, designated here as igVR, the intergenotypic variable region. A secreted E2661glycoprotein with simultaneous deletions of the three variable sequences retained its ability to bind CD81 and conformation-dependent monoclonal antibodies (MAbs) and displayed enhanced binding to a neutralizing MAb directed to E2 immunogenic domain B. Our data provide insights into the E2 structure by suggesting that the three variable regions reside outside a conserved E2 core.
Differential Inhibition of Long Interspersed Element 1 by APOBEC3 Does Not Correlate with High-Molecular-Mass-Complex Formation or P-Body Association
Authors: Niewiadomska Anna Maria , Tian Chunjuan , Tan Lindi , Wang Tao , Sarkis Phuong Thi Nguyen , Yu Xiao-Fang
Published: June 2007

The human cytidine deaminase APOBEC3G (A3G) and other APOBEC3 proteins exhibit differential inhibitory activities against diverse endogenous retroelements and retroviruses, including Vif-deficient human immunodeficiency virus type 1. The potential inhibitory activity of human APOBEC proteins against long interspersed element 1 (LINE-1) has not been fully evaluated. Here, we demonstrate inhibition of LINE-1 by multiple human APOBEC3 cytidine deaminases, including previously unreported activity for A3DE and A3G. More ancient members of APOBEC, cytidine deaminases AID and APOBEC2, had no detectable activity against LINE-1. A3A, which did not form high-molecular-mass (HMM) complexes and interacted poorly with P bodies, was the most potent inhibitor of LINE-1. A3A specifically recognizes LINE-1 RNA but not the other cellular RNAs tested. However, in the presence of LINE-1, A3A became associated with HMM complexes containing LINE-1 RNA. The ability of A3A to recognize LINE-1 RNA required its catalytic domain and was important for its LINE-1 suppression. Although the mechanism of LINE-1 restriction did not seem to involve DNA editing, A3A inhibited the accumulation of nascent LINE-1 DNA, suggesting interference with LINE-1 reverse transcription and/or integration or intracellular movement of LINE-1 ribonucleoprotein. Thus, association with P bodies or cellular HMM complexes could not predict the potency of APOBEC3 anti-LINE-1 activities. The catalytic domain of APOBEC3 proteins may be important for proper folding and target factors such as RNA or protein interaction in addition to cytidine deamination.
Preparation and Crystal Structures of Low-Valent Zirconocene Complexes Containing Tetramethyl(phenyl)cyclopentadienyl Ligands
Authors: Horáček Michal , Pinkas Jiří , Kubišta Jiří , Císařová Ivana , Gyepes Róbert , Štěpnička Petr
Published: June 2007

Zirconocene complex [ZrCl2(η5-C5Me4Ph)2] (1) prepared by metathesis of the appropriate lithium cyclopentadienide and ZrCl4 was reduced with magnesium in tetrahydrofuran in the presence of excess bis(trimethylsilyl)acetylene, yielding the low-valent complex [Zr(η5-C5Me4Ph)2- (η2-Me3SiC≡CSiMe3)] (2). However, in addition to 2, the reduction afforded an unexpected Zr(II) complex [Zr(η5-C5Me4Ph)2(s-trans-η4-buta-1,3-diene)] (3). Compounds 1-3 were characterized by spectroscopic methods and by X-ray single-crystal diffraction.
Remote Metal-Arene π Bonding in Organometallic Complexes: a DFT Study
Authors: Costa Paulo J. , Calhorda Maria José , Pregosin Paul S.
Published: June 2007

The observation that the 14-electron cation [Rh(PPh3)3]+ is more electron-rich than expected, as a result of coordination of a C=C bond in one phenyl group, opened the way to a search for more examples of this behavior. We used DFT calculations and energy decomposition analysis to study this M-η2-arene interaction and to calculate its strength. For this purpose, we have chosen two formally unsaturated complexes, viz. [Mo(η5-C5H5)(CO)2(PPh3)]+ (1) and [Ru(η5-C5H5)(binap)]+ (2). In the former complex, the PPh3 ligand can be easily moved away from the metal, destroying the Mo-η2-arene interaction, while in 2 this is achieved by a distortion of the Binap ligand. The experimental parameters, namely the distortion of the aryl-containing ligand, have been well reproduced by the calculated coordination geometry; the M-η2-arene interaction was estimated as 13.4 kcal mol-1 for Mo and 21.4 kcal mol-1 for Ru. The energy decomposition analysis revealed the formation of a covalent bond between the metal and the C=C bond, which made the global process favorable, regard- less the energy required to reorganize the geometry of the ligand in the new environment.
Sports-related acute and chronic avulsion injuries in children and adolescents with special emphasis on tennis
Authors: Vandervliet Everhard J M , Vanhoenacker Filip M , Snoeckx Annemie , Gielen Jan L , Van Dyck Pieter , Parizel Paul M
Published: June 2007

Acute and chronic sports-related muscle and tendon injuries are not infrequent in youngsters. In particular, the physis is prone to trauma as it constitutes the weakest part of the immature skeleton. The type of sports activity determines the location of the lesion. Most commonly, apophyses of the hip and pelvis are subject to avulsion. The purpose of this paper is to give a short overview of the pathogenesis, location, prevalence and imaging characteristics of acute and chronic avulsion injuries in the immature skeleton, with special emphasis on tennis-related injuries. Tennis-related injuries particularly involve apophyses of the ischial tuberosity, the anterior inferior or superior iliac spine and the iliac crest.
Effect of tadalafil on anaerobic performance indices in healthy athletes
Authors: Guidetti L , Emerenziani G P , Gallotta M C , Pigozzi F , Di Luigi L , Baldari C
Published: June 2007

Objective:

Given the therapeutic and non-therapeutic use of the tadalafil, (phosphodiesterase-5 inhibitor, PDE-5i), we examined its effects on anaerobic performance indices.

Methods:

In total, 12 well-trained subjects reported to the laboratory on two occasions 1 week apart to perform a 30 s Wingate anaerobic power test (WAnT) on a bicycle ergometer. The day before the WAnT, the subjects were double-blinded to receive an oral dose of tadalafil (20 mg) or placebo. Blood lactate value at rest and 1, 3, 6 and 10 minutes of recovery phase, mean power, peak power, time to peak power and fatigue index were assessed for each WAnT.

Results:

Blood lactate values at the 3-min recovery WAnT increased significantly in the tadalafil condition (mean (SD) 13.9 (1.7)v12.8 (1.3) mmol/l; p<0.05) and time to peak power decreased significantly (6.3 (1.3)v5.7 (1.5) s; p = 0.05). No differences were observed in any other parameters between the two conditions.

Conclusion:

The primary finding of this investigation was that the administration of a single dose of a long-term PDE-5i does not substantially influence anaerobic performance indices. However, results demonstrated both an increase in lactate values at the 3-min point of the recovery phase and a decrease in time to peak power.
Circuit weight training and cardiac morphology: a trial with magnetic resonance imaging
Authors: Camargo M D , Stein R , Ribeiro J P , Schvartzman P R , Rizzatti M O , Schaan B D
Published: June 2007

Background:

Aerobic training (AT) and circuit weight training (CWT) improve peak oxygen uptake (VO2peak). During CWT the circulatory system is exposed to higher pressure, which could induce left ventricle morphological adaptations, possibly distinct from those derived from aerobic training.

Objective:

To compare the effects of aerobic training and CWT upon morphological and functional cardiac adaptations detected by magnetic resonance imaging.

Methods:

Twenty healthy sedentary individuals were randomly assigned to participate in a 12-week programme of aerobic training (n = 6), CWR (n = 7) or no intervention (n = 7, controls). Training programmes consisted of 36 sessions, 35 min each, 3 times per week, at 70% of maximal heart rate, and CWT included series of resistance exercises performed at 60% of 1 maximal repetition. Cardiopulmonary exercise testing and cardiac magnetic resonance imaging were performed before and after the intervention.

Results:

There was a similar improvement in VO2peakfollowing aerobic training (mean (SD) increment: 12 (4)%) and CWT (12 (4)%), while there was no change in the control group. Aerobic training (12 (6)%) and CWT (16 (5)%) improved strength in the lower limbs, and only CWT resulted in improvement of 13 (4)% in the strength of the upper limbs. However, there were no detectable changes in left ventricular mass, end-diastolic volume, stroke volume or ejection fraction.

Conclusion:

In previously sedentary individuals, short-term CWT and aerobic training induce similar improvement in functional capacity without any adaptation in cardiac morphology detectable by cardiac magnetic resonance imaging.
EpCAM is predominantly expressed in high grade and advanced stage urothelial carcinoma of the bladder
Authors: Brunner A , Prelog M , Verdorfer I , Tzankov A , Mikuz G , Ensinger C
Published: June 2007

Background:

EpCAM is an adhesion molecule of the basolateral membranes in a variety of epithelial cells. Over-expression has been detected in many epithelial tumours and has been associated with high stage, high grade and a worse survival in some tumour types.

Aims:

To assess the prognostic value of EpCAM in urothelial carcinoma of the bladder.

Methods:

EpCAM expression was analysed by immunohistochemistry using a monoclonal antibody (clone VU-1D9) on a tissue microarray comprising 99 urothelial carcinomas of the bladder diagnosed between 1994 and 1997.

Results:

A significant relationship between high grade, advanced stage, and EpCAM expression was found, and expression of EpCAM was associated with a worse overall survival when compared to EpCAM negative tumours (p = 0.033). Multivariate analysis showed that EpCAM expression was not an independent prognostic factor for overall survival in urothelial carcinoma of the bladder.

Conclusion:

EpCAM expression is associated with advanced stage, high grade and poor overall survival in urothelial carcinoma of the bladder, but lacks an independent prognostic significance. The strong association with high grade tumours suggests a possible role during tumour progression and makes EpCAM a potential target for antibody mediated therapy.
PROOF OF TRIVIALITY OF λϕ4 THEORY
Authors: FRASCA MARCO
Published: June 2007

We show that a recent analysis in the strong coupling limit of the λϕ4 theory proves that this theory is indeed trivial giving in this limit the expansion of a free quantum field theory. We can get in this way the propagator with the renormalization constant and the renormalized mass. As expected the theory in this limit has the same spectrum as a harmonic oscillator. Some comments about triviality of the Yang–Mills theory in the infrared are also given.
GRAVITATIONAL WAVEFORMS FOR FINITE MASS BINARIES
Authors: VASÚTH MÁTYÁS , MAJÁR JÁNOS
Published: June 2007

One of the promising sources of gravitational radiation is a binary system composed of compact stars. It is an important question of how the rotation of the bodies and the eccentricity of the orbit affect the detectable signal. Here we present a method to evaluate the gravitational wave polarization states for inspiralling compact binaries with comparable mass. We consider eccentric orbits and the spin-orbit contribution in the case of one spinning object up to 1.5 post-Newtonian order. For circular orbits our results are in agreement with existing calculations.
CAVITY SCALING: AUTOMATED REFINEMENT OF CAVITY-AWARE MOTIFS IN PROTEIN FUNCTION PREDICTION
Authors: CHEN BRIAN Y. , BRYANT DREW H. , FOFANOV VIACHESLAV Y. , KRISTENSEN DAVID M. , CRUESS AMANDA E. , KIMMEL MAREK , LICHTARGE OLIVIER , KAVRAKI LYDIA E.
Published: June 2007

Algorithms for geometric and chemical comparison of protein substructure can be useful for many applications in protein function prediction. These motif matching algorithms identify matches of geometric and chemical similarity between well-studied functional sites, motifs, and substructures of functionally uncharacterized proteins, targets. For the purpose of function prediction, the accuracy of motif matching algorithms can be evaluated with the number of statistically significant matches to functionally related proteins, true positives (TPs), and the number of statistically insignificant matches to functionally unrelated proteins, false positives (FPs).

Our earlier work developed cavity-aware motifs which use motif points to represent functionally significant atoms and C-spheres to represent functionally significant volumes. We observed that cavity-aware motifs match significantly fewer FPs than matches containing only motif points. We also observed that high-impact C-spheres, which significantly contribute to the reduction of FPs, can be isolated automatically with a technique we call Cavity Scaling.

This paper extends our earlier work by demonstrating that C-spheres can be used to accelerate point-based geometric and chemical comparison algorithms, maintaining accuracy while reducing runtime. We also demonstrate that the placement of C-spheres can significantly affect the number of TPs and FPs identified by a cavity-aware motif. While the optimal placement of C-spheres remains a diffcult open problem, we compared two logical placement strategies to better understand C-sphere placement.
SYMBOLIC SEQUENCE ANALYSIS METHOD OF GAS/LIQUID TWO-PHASE FLOW MEASUREMENT FLUCTUATION SIGNALS
Authors: JIN NINGDE , MIAO LINGYU , LI WEIBO
Published: June 2007

Symbolic sequence analysis method was applied to analyze two-phase flow measurement fluctuating signals and some issues about key parameters which were effect on the symbolic statistical quantities were discussed. Based on the above study, eighty groups differential pressure fluctuating signals of gas/liquid two-phase flow were gathered in vertical upward pipes and we extracted the time irreversibility and chi-square statistics. When the gas superficial velocity is less than 0.02 m/s, the random variable motion feature and the dynamic character of bubble flow become gradually complex with the gas superficial velocity increasing. When gas superficial velocity exceeds 0.02 m/s, the dynamic character of flow pattern evolution becomes gradually simple from bubble flow to slug flow and the dynamic character becomes more and more complex from slug flow to churn flow with increasing gas superficial velocity. This study shows that time irreversibility and chi-square statistics are sensitive feature quantities of characterizing gas/liquid two-phase flow patterns and this can better help for understanding dynamic characteristics of gas/liquid two-phase flow patterns by observing the two statistical quantities changing with the two-phase flow parameters.
Role of S4 positively charged residues in the regulation of Kv4.3 inactivation and recovery
Authors: Skerritt Matthew R. , Campbell Donald L.
Published: June 2007

The molecular and biophysical mechanisms by which voltage-sensitive K+ (Kv)4 channels inactivate and recover from inactivation are presently unresolved. There is a general consensus, however, that Shaker-like N- and P/C-type mechanisms are likely not involved. Kv4 channels also display prominent inactivation from preactivated closed states [closed-state inactivation (CSI)], a process that appears to be absent in Shaker channels. As in Shaker channels, voltage sensitivity in Kv4 channels is thought to be conferred by positively charged residues localized to the fourth transmembrane segment (S4) of the voltage-sensing domain. To investigate the role of S4 positive charge in Kv4.3 gating transitions, we analyzed the effects of charge elimination at each positively charged arginine (R) residue by mutation to the uncharged residue alanine (A). We first demonstrated that R290A, R293A, R296A, and R302A mutants each alter basic activation characteristics consistent with positive charge removal. We then found strong evidence that recovery from inactivation is coupled to deactivation, showed that the precise location of the arginine residues within S4 plays an important role in the degree of development of CSI and recovery from CSI, and demonstrated that the development of CSI can be sequentially uncoupled from activation by R296A, specifically. Taken together, these results extend our current understanding of Kv4.3 gating transitions.
The pinwheel experiment revisited: effects of cellular electrophysiological properties on vulnerability to cardiac reentry
Authors: Yang Ming-Jim , Tran Diana X. , Weiss James N. , Garfinkel Alan , Qu Zhilin
Published: June 2007

In normal heart, ventricular fibrillation can be induced by a single properly timed strong electrical or mechanical stimulus. A mechanism first proposed by Winfree and coined the “pinwheel experiment” emphasizes the timing and strength of the stimulus in inducing figure-of-eight reentry. However, the effects of cellular electrophysiological properties on vulnerability to reentry in the pinwheel scenario have not been investigated. In this study, we extend Winfree's pinwheel experiment to show how the vulnerability to reentry is affected by the graded action potential responses induced by a strong premature stimulus, action potential duration (APD), and APD restitution in simulated monodomain homogeneous two-dimensional tissue. We find that a larger graded response, longer APD, or steeper APD restitution slope reduces the vulnerable window of reentry. Strong graded responses and long APD promote tip-tip interactions at long coupling intervals, causing the two initiated spiral wave tips to annihilate. Steep APD restitution promotes wave front-wave back interaction, causing conduction block in the central common pathway of figure-of-eight reentry. We derive an analytical treatment that shows good agreement with numerical simulation results.
TRPV1 gene knockout impairs preconditioning protection against myocardial injury in isolated perfused hearts in mice
Authors: Zhong Beihua , Wang Donna H.
Published: June 2007

Although the transient receptor potential vanilloid type 1 (TRPV1)-containing afferent nerve fibers are widely distributed in the heart, the relationship between TRPV1 function and cardiac ischemic preconditioning (PC) has not been well defined. Using TRPV1 knockout mice (TRPV1−/−), we studied the role of TRPV1 in PC-induced myocardial protection. Hearts of gene-targeted TRPV1-null mutant (TRPV1−/−) or wild-type (WT) mice were Langendorffly perfused in the presence or absence of CGRP8-37, a selective calcitonin gene-related peptide (CGRP) receptor antagonist; or RP-67580, a selective neurokinin-1 receptor antagonist when hearts were subjected to three 5-min periods of ischemia PC followed by 30 min of global ischemia and 40 min of reperfusion (I/R). PC before I/R decreased left ventricular (LV) end-diastolic pressure and increased LV developed pressure, coronary flow (CF), peak-positive maximum rate of rise of LV pressure in WT mice (PC-WT) compared with PC-TRPV1−/−, TRPV1−/−, or WT hearts ( P < 0.05), and PC also decreased LV end-diastolic pressure in PC-TRPV1−/−compared with TRPV1−/−. CGRP8-37or RP-67580 abolished PC-induced protection in WT but not TRPV1−/−hearts ( P < 0.05). Moreover, PC decreased lactate dehydrogenase release and infarct size in PC-WT compared with PC-TRPV1−/−, TRPV1−/−, or WT hearts, and it also lowered these parameters in PC-TRPV1−/−compared with TRPV1−/−hearts ( P < 0.05). Radioimmunoassay showed that the release of substance P and CGRP after PC was higher in WT hearts than in TRPV1−/−hearts ( P < 0.05), which was attenuated by capsazepine in WT but not TRPV1−/−hearts. Thus PC-induced protection of the heart was impaired in TRPV1−/−hearts, indicating that TRPV1 contributes to the beneficial effects of preconditioning against I/R injury through release substance P and CGRP.
Role of cardiac overexpression of ANG II in the regulation of cardiac function and remodeling postmyocardial infarction
Authors: Xu Jiang , Carretero Oscar A. , Lin Chun-Xia , Cavasin Maria A. , Shesely Edward G. , Yang James J. , Reudelhuber Timothy L. , Yang Xiao-Ping
Published: June 2007

ANG II has a clear role in development of cardiac hypertrophy, fibrosis, and dysfunction. It has been difficult, however, to determine whether these actions are direct or consequences of its systemic hemodynamic effects in vivo. To overcome this limitation, we used transgenic mice with cardiac-specific expression of a transgene fusion protein that releases ANG II from cardiomyocytes (Tg-ANG II-cardiac) without involvement of the systemic renin-angiotensin system and tested whether increased cardiac ANG II accelerates remodeling and dysfunction postmyocardial infarction (MI), whereas those mice show no evidence of cardiac hypertrophy under the basal condition. Male 12- to 14-wk-old Tg-ANG II-cardiac mice and their wild-type littermates (WT) were subjected to sham-MI or MI by ligating the left anterior descending coronary artery for 8 wk. Cardiac ANG II levels were ∼10-fold higher in Tg-ANG II-cardiac mice than their WT, whereas ANG II levels in plasma and other tissues did not differ between strains. Systolic blood pressure and heart rate were similar between groups with or without MI. In sham-MI, Tg-ANG II-cardiac mice had increased collagen deposition and decreased capillary density. The differences between strains became more pronounced after MI. Although cardiac function was well preserved in the Tg-ANG II-cardiac mice with sham-MI, cardiac remodeling and dysfunction post-MI were more severe than WT. Our results demonstrate that, independent of systemic hemodynamic effects, cardiac ANG II may act locally in the heart, causing interstitial fibrosis in sham-MI and accelerating deterioration of cardiac dysfunction and remodeling post-MI.
Homocysteine induces VCAM-1 gene expression through NF-κB and NAD(P)H oxidase activation: protective role of Mediterranean diet polyphenolic antioxidants
Authors: Carluccio Maria Annunziata , Ancora Maria Assunta , Massaro Marika , Carluccio Marisa , Scoditti Egeria , Distante Alessandro , Storelli Carlo , De Caterina Raffaele
Published: June 2007

Hyperhomocysteinemia is a recognized risk factor for vascular disease, but pathogenetic mechanisms involved in its vascular actions are largely unknown. Because VCAM-1 expression is crucial in monocyte adhesion and early atherogenesis, we evaluated the NF-κB-related induction of VCAM-1 by homocysteine (Hcy) and the possible inhibitory effect of dietary polyphenolic antioxidants, such as trans-resveratrol (RSV) and hydroxytyrosol (HT), which are known inhibitors of NF-κB-mediated VCAM-1 induction. In human umbilical vein endothelial cells (HUVEC), Hcy, at 100 μmol/l, but not cysteine, induced VCAM-1 expression at the protein and mRNA levels, as shown by enzyme immunoassay and Northern analysis, respectively. Transfection studies with deletional VCAM-1 promoter constructs demonstrated that the two tandem NF-κB motifs in the VCAM-1 promoter are necessary for Hcy-induced VCAM-1 gene expression. Hcy-induced NF-κB activation was confirmed by EMSA, as shown by the nuclear translocation of its p65 (RelA) subunit and the degradation of the inhibitors IκB-α and IκB-β by Western analysis. Hcy also increased intracellular reactive oxygen species by NAD(P)H oxidase activation, as shown by the membrane translocation of its p47phox subunit. NF-κB inhibitors decreased Hcy-induced intracellular reactive oxygen species and VCAM-1 expression. Finally, we found that nutritionally relevant concentrations of RSV and HT, but not folate and vitamin B6, reduce (by >60% at 10−6 mol/l) Hcy-induced VCAM-1 expression and monocytoid cell adhesion to the endothelium. These data indicate that pathophysiologically relevant Hcy concentrations induce VCAM-1 expression through a prooxidant mechanism involving NF-κB. Natural Mediterranean diet antioxidants can inhibit such activation, suggesting their possible therapeutic role in Hcy-induced vascular damage.