bluuebunny/crossref_metadata_2025 huggingface dataset:
Monoclonal Antibody-Based Antigen Capture Enzyme-Linked Immunosorbent Assay Reveals High Sensitivity of the Nucleocapsid Protein in Acute-Phase Sera of Severe Acute Respiratory Syndrome Patients
Authors: Di Biao , Hao Wei , Gao Yang , Wang Ming , Wang Ya-di , Qiu Li-wen , Wen Kun , Zhou Duan-hua , Wu Xin-wei , Lu En-jie , Liao Zhi-yong , Mei Ya-bo , Zheng Bo-jian , Che Xiao-yan
Published: January 2005

Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.
Induction of Thymus-Derived γδ T Cells byEscherichia coliEnterotoxin B Subunit in Peritoneal Cavities of Mice
Authors: Shimizu Toshiyasu , Sasaki Keiko , Kato Michio , Arimitsu Hideyuki , Ochi Sadayuki , Shigemori Naoko , Wasito Eddy Bagus , Yokochi Takashi , Tsuji Takao
Published: January 2005

We examined the activation of intraperitoneal T cells in BALB/c mice by theEscherichia colienterotoxin B subunit, which induced a specific Th2 type of T-cell response to intraperitoneally coadministered bovine immunoglobulin G. The numbers of both γδ and αβ T cells increased significantly after intraperitoneal administration of the B subunit in a time-dependent manner; these numbers were not affected by the B-subunit G33D mutant, which is defective in GM1ganglioside-binding ability. Early after administration a small number of γδ T cells produced either interleukin-4 (IL-4) or gamma interferon, while late after administration primarily IL-10-producing γδ T cells were detected. γδ T cells induced by the B subunit did not express a characteristic V gene over the time course of the study. The induction of γδ T cells did not occur in athymicnu/numice but could be induced upon transplantation of fetal AKR thymus-like αβ T cells. γδ T cells in athymicnu/numice with a fetal thymic graft predominantly expressed the donor Thy-1.1 antigen but not the host Thy-1.2 antigen. The induction of these T cells, however, could not be restored by coadministration of the B subunit with peritoneal cells from normal mice. These results suggest that the B subunit activates intraperitoneal γδ and αβ T cells in a manner dependent upon its ability to bind to GM1ganglioside. γδ T cells induced by the B subunit are Th2-type cells derived from the thymus. These γδ T cells may be functionally involved in specific Th2 responses to the B subunit, which possibly acts as an adjuvant through the influence of αβ T cells.
Immunofluorescence Assay for Detection of Human Metapneumovirus-Specific Antibodies by Use of Baculovirus-Expressed Fusion Protein
Authors: Ishiguro Nobuhisa , Ebihara Takashi , Endo Rika , Ma Xiaoming , Shirotsuki Ryo , Ochiai Susumu , Ishiko Hiroaki , Kikuta Hideaki
Published: January 2005

Human metapneumovirus (hMPV) has recently been identified as an etiological agent of acute respiratory infections. The hMPV fusion (F) protein has been indicated to be a major antigenic determinant that mediates effective neutralization and protection against hMPV infection. We developed a new immunofluorescence assay (IFA) using
Trichoplusia ni
(Tn5) insect cells infected with a recombinant baculovirus-expressing hMPV F protein (Bac-F IFA). A total of 200 serum samples from Japanese people 1 month to 41 years old were tested for immunoglobulin G antibodies to hMPV F protein by Bac-F IFA. The results were compared with those of the conventional IFA based on hMPV-infected LLC-MK2 cells (hMPV IFA). The titers obtained by the two IFAs correlated well (correlation coefficient of 0.88), and the concordance of seroreactivities between the two IFAs was 91% (κ = 0.76). For 192 of the 200 serum samples, the titers obtained by the Bac-F IFA were equal to or higher than those obtained by the hMPV IFA. These results indicated that the Bac-F IFA was more sensitive than the hMPV IFA and that the majority of the antibodies detected by the hMPV IFA reacted with the hMPV F protein. The Bac-F IFA is a more reliable, sensitive, and specific method for the detection of hMPV antibodies than is the hMPV IFA.
Differentiation, Maturation, and Survival of Dendritic Cells by Osteopontin Regulation
Authors: Kawamura Kodai , Iyonaga Kazuhiro , Ichiyasu Hidenori , Nagano Junji , Suga Moritaka , Sasaki Yutaka
Published: January 2005

Dendritic cells (DCs) are antigen-presenting cells with the ability to induce primary immune responses necessary in innate immunity and adaptive immunity. Osteopontin (OPN) is a secreted acidic phosphoprotein containing an arginine-glycine-aspartate sequence and has been suggested to play an important role in early cellular immune responses. The interaction between DCs and OPN has not been clarified. We hypothesized that there is an important interaction between DCs and OPN, which is an indispensable extracellular matrix component in early cellular immune responses. Human monocyte-derived DCs synthesized OPN especially during the differentiation from monocytes to immature DCs. By blocking of OPN with anti-OPN antibody, cultured DCs became smaller and expressed lower levels of costimulatory molecules and major histocompatibility complex class II antigens than untreated DCs. Furthermore, DCs treated with anti-OPN antibody easily underwent apoptosis. These results suggest that human DCs can produce OPN and that OPN may play a role in the differentiation, maturation, and survival of DCs by autocrine and/or paracrine pathways.
Evaluation of a West Nile Virus Immunoglobulin A Capture Enzyme-Linked Immunosorbent Assay
Authors: Prince Harry E. , Lapé-Nixon Mary
Published: January 2005

An in-house-developed enzyme-linked immunosorbent assay detected West Nile virus (WNV) immunoglobulin A (IgA) in 65 of 68 sera from WNV-infected patients; 40 of 63 WNV IgM-positive, IgG-negative serum or plasma specimens; 65 of 67 WNV IgM-positive, IgG-positive specimens; 0 of 70 WNV IgM-negative, IgG-negative specimens; and 0 of 64 archived blood donation sera. WNV IgA is thus highly prevalent among WNV-infected patients and typically appears after WNV IgM but before WNV IgG.
Use of Glycopeptidolipid Core Antigen for Serodiagnosis of
Mycobacterium avium
Complex Pulmonary Disease in Immunocompetent Patients
Authors: Kitada Seigo , Maekura Ryoji , Toyoshima Naomi , Naka Takashi , Fujiwara Nagatoshi , Kobayashi Masami , Yano Ikuya , Ito Masami , Kobayashi Kazuo
Published: January 2005

We report the development of a serodiagnostic method for
Mycobacterium avium
complex (MAC) disease with an enzyme immunoassay (EIA) with the MAC-specific glycopeptidolipid (GPL) core as the antigen. In this study, we confirmed by EIA that the GPL core antibody was in the sera of immunocompetent patients with MAC disease. The EIA for quantifying the GPL core antibody was evaluated as a clinical tool for serodiagnosis of pulmonary MAC disease. A significant increase in GPL core antibodies (immunoglobulins G, A, and M) was detected in sera of patients with MAC pulmonary diseases when they were compared to patients who were colonized with MAC, patients with
Mycobacterium kansasii
disease or tuberculosis, and healthy subjects. The sensitivities and specificities of the GPL core-based EIA for diagnosis of MAC pulmonary disease were 72.6% and 92.2%, respectively, for IgG, 92.5% and 95.1%, respectively, for IgA, and 78.3% and 91.0%, respectively, for IgM. The best sensitivity and specificity were obtained by measuring immunoglobulin A antibodies against GPL core antigen. The level of GPL core antibodies reflected disease activity, since it decreased in cured MAC patients who had responded to chemotherapy. Measurement of serum antibodies against GPL core is useful for both diagnosis and assessment of disease activity in MAC disease of the lung.
Antinucleosome Antibodies and Decreased Deoxyribonuclease Activity in Sera of Patients with Systemic Lupus Erythematosus
Authors: Sallai Krisztina , Nagy Eszter , Derfalvy Beata , Müzes Györgyi , Gergely Peter
Published: January 2005

Nucleosomes are the dominant autoantigens in patients with systemic lupus erythematosus (SLE), and immune complexes involving nucleosomes are the major cause of tissue damage. The activity of DNase I, the enzyme responsible for nucleosome degradation, has been found to be decreased in patients with SLE. However, it is not known whether DNase activity is a clinically useful parameter. The aim of our study was to assess DNase activity in a prospective study of 113 patients with SLE in relation to disease activity and organ involvement. We included two control groups: 9 patients with undifferentiated connective tissue disease (UCTD) and 14 healthy individuals. DNase activity was found to be lower in patients with SLE (63.75% ± 12.1%) than in the controls (81.3% ± 9.25%) (
P
< 0.001). DNase activity in patients with UCTD (64.9% ± 18.2%;
P
= 0.854) did not differ from that in patients with SLE. Patients with SLE had higher antinucleosome antibody titers (356.3 ± 851) than the controls (1.44 ± 2.77;
P
< 0.01) or UCTD patients (39.9 ± 57.7;
P
< 0.01). In addition, samples positive for antinucleosome antibodies displayed low levels of DNase activity. Within the SLE group, the presence of renal disease had no impact on DNase activity or antinucleosome antibody titers. Also, the SLE disease activity index showed no correlation with DNase activity. In a longitudinal study of six SLE patients, DNase activity did not follow disease activity or autoantibody titers. Our results confirm that serum DNase activity is decreased in patients with SLE, but we conclude that it is not a clinically useful parameter for the prediction of flare-ups of disease or renal involvement.
Pediatric Human Immunodeficiency Virus Screening in an African District Hospital
Authors: De Baets A. J. , Edidi B. S. , Kasali M. J. , Beelaert G. , Schrooten W. , Litzroth A. , Kolsteren P. , Denolf D. , Fransen K.
Published: January 2005

In order to evaluate alternative tests and strategies to simplify pediatric human immunodeficiency virus (HIV) screening at the district hospital level, a cross-sectional exploratory study was organized in the Democratic Republic of the Congo. Venous and capillary phlebotomies were performed on 941 Congolese children, aged 1 month to 12 years (153 children under 18 months and 788 children more than 18 months old). The HIV prevalence rate was 4.7%. An algorithm for children more than 18 months old, using serial rapid tests (Determine, InstantScreen, and Uni-Gold) performed on capillary blood stored in EDTA tubes, had a sensitivity of 100.0% (95% confidence interval [CI], 88.9 to 100.0%) and a specificity of 100.0% (95% CI, 99.5 to 100.0%). The results of this study suggest that the ultrasensitive p24 antigen assay may be performed on capillary plasma stored on filter paper (sensitivity and specificity, 100.0%;n= 87) instead of venous plasma (sensitivity, 92.3%; specificity, 100.0%;n= 150). The use of glucolets (instruments used to perform capillary phlebotomies), instead of syringes and needles, may reduce procedural pain and the risk of needle stick injuries at a comparable cost. Compared to the reference, HIV could have been correctly excluded based on one rapid test for at least 90% of these children. The results of this study point towards underutilized opportunities to simplify phlebotomy and pediatric HIV screening.
Role of the Simian Virus 5 Fusion Protein N-Terminal Coiled-Coil Domain in Folding and Promotion of Membrane Fusion
Authors: West Dava S. , Sheehan Michael S. , Segeleon Patrick K. , Dutch Rebecca Ellis
Published: January 2005

Formation of a six-helix bundle comprised of three C-terminal heptad repeat regions in antiparallel orientation in the grooves of an N-terminal coiled-coil is critical for promotion of membrane fusion by paramyxovirus fusion (F) proteins. We have examined the effect of mutations in four residues of the N-terminal heptad repeat in the simian virus 5 (SV5) F protein on protein folding, transport, and fusogenic activity. The residues chosen have previously been shown from study of isolated peptides to have differing effects on stability of the N-terminal coiled-coil and six-helix bundle (R. E. Dutch, G. P. Leser, and R. A. Lamb, Virology 254:147-159, 1999). The mutant V154M showed reduced proteolytic cleavage and surface expression, indicating a defect in intracellular transport, though this mutation had no effect when studied in isolated peptides. The mutation I137M, previously shown to lower thermostability of the six-helix bundle, resulted in an F protein which was properly processed and transported to the cell surface but which had reduced fusogenic activity. Finally, mutations at L140M and L161M, previously shown to disrupt α-helix formation of isolated N-1 peptides but not to affect six-helix bundle formation, resulted in F proteins that were properly processed. Interestingly, the L161M mutant showed increased syncytium formation and promoted fusion at lower temperatures than the wild-type F protein. These results indicate that interactions separate from formation of an N-terminal coiled-coil or six-helix bundle are important in the initial folding and transport of the SV5 F protein and that mutations that destabilize the N-terminal coiled-coil can result in stimulation of membrane fusion.
Epstein-Barr Virus Nuclear Antigen 1 Interacts with Nm23-H1 in Lymphoblastoid Cell Lines and Inhibits Its Ability To Suppress Cell Migration
Authors: Murakami Masanao , Lan Ke , Subramanian Chitra , Robertson Erle S.
Published: January 2005

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is expressed in the majority of latency programs in EBV-infected cells and is critical for the maintenance of EBV episomes in the infected cells. EBNA1 is also known to be involved in transcriptional activation and regulates expression of the EBV latent genes, including the EBNAs and LMP1. Thus, EBNA1 is a multifunctional protein with critical functions required for the persistence of the viral genome over successive generations, producing new daughter cells from the infected cell. We identify EBNA1 here as an interacting EBNA with the known suppressor of metastasis and cell migration, Nm23-H1. Nm23-H1 inhibits cell migration when expressed in cancer cells. We show that EBNA1 associates with Nm23-H1 in EBV-infected cells in vitro, as well as in lymphoblastoid cell lines (LCLs). Nm23-H1 predominantly localizes to the cytoplasm in BJAB and 293T cells; however, upon expression of EBNA1, Nm23-H1 is translocated to the nucleus in similar compartments to EBNA1, suggesting a potential functional role that is linked to EBNA1. Convincingly, in EBV-transformed LCLs Nm23-H1 is localized predominantly to the nucleus and colocalizes to similar compartment as EBNA1. Further, we tested the effects of EBNA1 on Nm23-H1-mediated suppression of cell migration and showed that EBNA1 rescues the suppression of cell migration mediated by Nm23-H1. These in vitro studies suggest that EBNA1 plays a critical role in regulating the activities of Nm23-H1, including cell migration, through a mechanism which involves direct interaction of this major regulator in EBV-infected cells.
Rodent Cells Support Key Functions of the Human Immunodeficiency Virus Type 1 Pathogenicity Factor Nef
Authors: Keppler Oliver T. , Allespach Ina , Schüller Lismarie , Fenard David , Greene Warner C. , Fackler Oliver T.
Published: January 2005

After infection with human immunodeficiency virus (HIV), progression toward immunodeficiency is governed by a complex interplay of viral and host determinants. The viral accessory protein Nef is a key factor for the development of AIDS. Strains of HIV and simian immunodeficiency virus that lack functional
nef
genes either do not induce AIDS or do so only after a significant delay. The validity of a transgenic-small-animal model for de novo infection by HIV will depend on its ability to recapitulate the actions of critical factors of viral pathogenicity, such as Nef. We assessed the ability of rat, mouse, and hamster cells to support key effector functions of Nef. In cell lines from rodents, the subcellular distribution of wild-type HIV type 1 strain SF2 Nef and mutants was comparable to that in human cells. Nef downregulated human CD4 from the cell surface, was associated with p21-activated kinase activity, and enhanced the infectivity of HIV-1 virions. Importantly, these Nef-induced effects, as well as the downregulation of rat CD4 and major histocompatibility complex class I molecules, could also be demonstrated in primary T lymphocytes and macrophages from human CD4-transgenic rats. Thus, HIV-1 Nef exerts key functions in rodent cells. In line with our ongoing efforts to establish a transgenic-rat model of HIV disease, these results indicate that important aspects of viral pathogenesis could be addressed in a transgenic-rodent model permissive for de novo infection and that such a model would be valuable for evaluating the function of Nef in vivo.
Regulation of Expression of the Epstein-Barr Virus BamHI-A Rightward Transcripts
Authors: Chen Honglin , Huang Jian , Wu Frederick Y. , Liao Gangling , Hutt-Fletcher Lindsey , Hayward S. Diane
Published: January 2005

The Epstein-Barr virus (EBV) BamHI-A rightward transcripts, or BARTs, are a family of mRNAs expressed in all EBV latency programs, including EBV-infected B cells in healthy carriers. Despite their ubiquitous expression, the regulation and biological function of BARTs are still unclear. In this study, the BART 5′ termini were characterized by using a procedure that selects capped, full-length mRNAs. Two TATA-less promoter regions, designated P1 and P2, were mapped. P1 had relatively high basal activity in both epithelial and B cells, whereas P2 exhibited higher activity in epithelial cells. Upon EBV infection of B cells, transcription from P1 was detected soon after infection, while expression from P2 was delayed. Promoter-reporter assays in transiently transfected cells revealed that P1 and P2 were differentially regulated. Interferon regulatory factor 7 (IRF7) and IRF5 negatively regulated P1 activity. c-Myc and C/EBP family members positively regulated P2. Regulation of P2 by C/EBPs was characterized by electrophoretic mobility shift assay, chromatin immunoprecipitation, and reporter assays. More-abundant BART expression in epithelial cells correlated with the relative expression of positive and negative regulators in these cells.
Semen-Specific Genetic Characteristics of Human Immunodeficiency Virus Type 1
env
Authors: Pillai Satish K. , Good Benjamin , Pond Sergei Kosakovsky , Wong Joseph K. , Strain Matt C. , Richman Douglas D. , Smith Davey M.
Published: January 2005

Human immunodeficiency virus type 1 (HIV-1) in the male genital tract may comprise virus produced locally in addition to virus transported from the circulation. Virus produced in the male genital tract may be genetically distinct, due to tissue-specific cellular characteristics and immunological pressures. HIV-1
env
sequences derived from paired blood and semen samples from the Los Alamos HIV Sequence Database were analyzed to ascertain a male genital tract-specific viral signature. Machine learning algorithms could predict seminal tropism based on
env
sequences with accuracies exceeding 90%, suggesting that a strong genetic signature does exist for virus replicating in the male genital tract. Additionally, semen-derived viral populations exhibited constrained diversity (
P
< 0.05), decreased levels of positive selection (
P
< 0.025), decreased CXCR4 coreceptor utilization, and altered glycosylation patterns. Our analysis suggests that the male genital tract represents a distinct selective environment that contributes to the apparent genetic bottlenecks associated with the sexual transmission of HIV-1.
Differential Induction of Antiviral Effects against West Nile Virus in Primary Mouse Macrophages Derived from Flavivirus-Susceptible and Congenic Resistant Mice by Alpha/Beta Interferon and Poly(I-C)
Authors: Pantelic Ljiljana , Sivakumaran Haran , Urosevic Nadezda
Published: January 2005

A cell model of primary macrophages isolated from the peritoneal cavity of flavivirus-susceptible and congenic resistant mice has been used to study the extent and kinetics of antiviral effects against West Nile virus upon priming with alpha/beta interferon (IFN-α/β) or poly(I-C) (pIC). The pattern of flavivirus resistance expressed after priming of cells in this model was in good agreement with the pattern of flavivirus resistance described in the brains of the corresponding mouse strains. While priming with either IFN-α/β or pIC completely blocked flavivirus replication in macrophages from resistant mice, it only transiently reduced flavivirus replication in macrophages from susceptible mice. It was only the combined pretreatment with IFN-α/β and pIC that elicited strong antiviral responses that completely prevented flavivirus replication in macrophages from susceptible mice. Primary macrophages isolated from the blood of healthy human donors expressed a similar need for double-stranded RNA (dsRNA) cofactor in developing efficient antiviral responses against West Nile virus. These findings reveal that the inefficient IFN-α/β-induced antiviral effects against flaviviruses in cells from susceptible hosts could be successfully complemented by an external dsRNA factor leading to the complete eradication of the virus. This treatment appears to compensate for the lack of an inborn resistance mechanism in cells from the susceptible host. Furthermore, it may also provide useful clues for the prevention and treatment of flavivirus infections.
Evidence for Heterogeneous Selective Pressures in the Evolution of the
env
Gene in Different Human Immunodeficiency Virus Type 1 Subtypes
Authors: Travers Simon A. A. , O'Connell Mary J. , McCormack Grace P. , McInerney James O.
Published: January 2005

Recent studies have demonstrated the emergence of human immunodeficiency virus type 1 (HIV-1) subtypes with various levels of fitness. Using heterogeneous maximum-likelihood models of adaptive evolution implemented in the PAML software package, with
env
sequences representing each HIV-1 group M subtype, we examined the various intersubtype selective pressures operating across the
env
gene. We found heterogeneity of evolutionary mechanisms between the different subtypes with a category of amino acid sites observed that had undergone positive selection for subtypes C, F1, and G, while these sites had undergone purifying selection in all other subtypes. Also, amino acid sites within subtypes A and K that had undergone purifying selection were observed, while these sites had undergone positive selection in all other subtypes. The presence of such sites indicates heterogeneity of selective pressures within HIV-1 group M subtype evolution that may account for the various levels of fitness of the subtypes.
Atypical Fusion Peptide of Nelson Bay Virus Fusion-Associated Small Transmembrane Protein
Authors: Cheng LiTing T. , Plemper Richard K. , Compans Richard W.
Published: January 2005

A 10-kDa nonstructural transmembrane protein (p10) encoded by a reovirus, Nelson Bay virus, has been shown to induce syncytium formation (34). Sequence analysis and structural studies identified p10 as a type I membrane protein with a central transmembrane domain, a cytoplasmic basic region, and an N-terminal hydrophobic domain (HD) that was hypothesized to function as a fusion peptide. We performed mutational analysis on this slightly hydrophobic motif to identify possible structural requirements for fusion activity. Bulky aliphatic residues were found to be essential for optimal fusion, and an aromatic or highly hydrophobic side chain was found to be required at position 12. The requirement for hydrophilic residues within the HD was also examined: substitution of 10-Ser or 14-Ser with hydrophobic residues was found to reduce cell surface expression of p10 and delayed the onset of syncytium formation. Nonconservative substitutions of charged residues in the HD did not have an effect on fusion activity. Taken together, our results suggest that the HD is involved in both syncytium formation and in determining p10 transport and surface expression.
Identification of Two Neutralizing Regions on the Severe Acute Respiratory Syndrome Coronavirus Spike Glycoprotein Produced from the Mammalian Expression System
Authors: Wang Shixia , Chou Te-hui W. , Sakhatskyy Pavlo V. , Huang Song , Lawrence John M. , Cao Hong , Huang Xiaoyun , Lu Shan
Published: January 2005

The Spike (S) protein of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) plays important roles in viral pathogenesis and potentially in the development of an effective vaccine against this virulent infectious disease. In this study, the codon-optimized S gene of SARS-CoV was synthesized to construct DNA vaccine plasmids expressing either the full-length or segments of the S protein. High titer S-specific immunoglobulin G antibody responses were elicited in rabbits immunized with DNA against various segments of the S protein. Two neutralizing domains were identified on the S protein, one at the N terminus (Ser12-Thr535) and the other near the C terminus (Arg797-Ile1192).
Enhanced Cytotoxicity without Internuclear Spread of Adenovirus upon Cell Fusion by Measles Virus Glycoproteins
Authors: Horn German P. , Vongpunsawad Sompong , Kornmann Evelyn , Fritz Barbara , Dittmer Dirk P. , Cattaneo Roberto , Dobbelstein Matthias
Published: January 2005

The efficiency of viruses in cancer therapy is enhanced by proteins that mediate the fusion of infected cells with their neighbors. It was reported that replication-competent adenovirus particles can spread between nuclei within fusion-generated syncytia. To assess this conjecture, we generated fusogenic adenoviruses that express a balanced ratio of the F and H glycoproteins of measles virus. The viruses displayed enhanced cytotoxicity but largely unchanged replication efficiencies compared to a nonfusogenic virus. Most notably, the virus genomes did not spread through fusion-generated multinuclear cells. Hence, adenovirus replication in syncytia remains largely restricted to initially transduced nuclei.
Anti-CXCR4 Monoclonal Antibodies Recognizing Overlapping Epitopes Differ Significantly in Their Ability To Inhibit Entry of Human Immunodeficiency Virus Type 1
Authors: Carnec Xavier , Quan Lan , Olson William C. , Hazan Uriel , Dragic Tatjana
Published: January 2005

CXCR4 is one of two physiologically relevant human immunodeficiency type 1 (HIV-1) entry coreceptors. Studies of CXCR4 mutants have not clearly identified the determinants of coreceptor function and specificity. We therefore used a panel of monoclonal antibodies to further elucidate CXCR4 expression, structure, and function. Our findings show the existence of conformational subpopulations of CXCR4 that are in equilibrium on the cell surface but are not cell type specific as previously reported. HIV-1 X4 isolates can interact with multiple CXCR4 conformations in order to gain entry into target cells.
Efficiency of pile groups installed in cohesionless soil using artificial neural networks
Authors: Hanna Adel M , Morcous George , Helmy Mary
Published: January 2005

This paper presents an artificial neural network (ANN) model that predicts the efficiency of pile groups installed in cohesionless soil and subjected to axial loading. The model accounts for the planar geometry of the group (pile diameter, pile spacing, and pile arrangement) and incorporates the effect of pile installation, pile length, cap condition, soil condition, and type of loading on the group efficiency. The results produced by the proposed ANN model compared well with the available results of laboratory and field tests. The ANN model is a viable design tool that assists foundation engineers in predicting the pile group efficiency in an accurate and realistic manner. In addition, this model can be easily updated to incorporate new data and accommodate new design parameters.Key words: axial load, pile foundation, group efficiency, cohesionless soil, artificial neural networks.
MODEL-BASED METHODS FOR STEGANOGRAPHY AND STEGANALYSIS
Authors: SALLEE PHIL
Published: January 2005

This paper presents methods for performing steganography and steganalysis using a statistical model of the cover medium. The methodology is general, and can be applied to virtually any type of media. It provides answers for some fundamental questions that have not been fully addressed by previous steganographic methods, such as how large a message can be hidden without risking detection by certain statistical methods, and how to achieve this maximum capacity. Current steganographic methods have been shown to be insecure against simple statistical attacks. Using the model-based methodology, an example steganography method is proposed for JPEG images that achieves a higher embedding efficiency and message capacity than previous methods while remaining secure against first order statistical attacks. A method is also described for defending against "blockiness" steganalysis attacks. Finally, a model-based steganalysis method is presented for estimating the length of messages hidden with Jsteg in JPEG images.
VALUATIONS OF k((X1,…,Xn)) WITH PREASSIGNED GROUP OF VALUES
Authors: GRANJA A.
Published: January 2005

Let Γ be a totally ordered abelian group of finite rational rank r. Consider s and n two non-negative integers with r+s≤n and denote by K a field. The main purpose of this paper is to construct a s-dimensional valuation v of the quotient field K((X1,…,Xn)) of the corresponding power series ring K[[X1,…,Xn]] such that v birrationally dominates K[[X1,…,Xn]] and has Γ as group of values. This is possible except for the case in which Γ=ℤ is the group of the integers, s=0, n≥2 and K does not admit an infinite algebraic extension. In this last case, we show that there does not exist such a valuation.
Regulation of the immunoexpression of aquaporin 9 by ovarian hormones in the rat oviductal epithelium
Authors: Brañes María C. , Morales Bernardo , Ríos Mariana , Villalón Manuel J.
Published: January 2005

The volume of oviductal fluid fluctuates during the estrous cycle, suggesting that water availability is under hormonal control. It has been postulated that sex-steroid hormones may regulate aquaporin (AQP) channels involved in water movement across cell membranes. Using a functional assay (oocytes of Xenopus laevis), we demonstrated that the rat oviductal epithelium contains mRNAs coding for water channels, and we identified by RT-PCR the mRNAs for AQP5, -8, and -9, but not for AQP2 and -3. The immunoreactivity for AQP5, -8, and -9 was localized only in epithelial cells of the oviduct. The distribution of AQP5 and -8 was mainly cytoplasmic, whereas we confirmed, by confocal microscopy, that AQP9 localized to the apical plasma membrane. Staining of AQP5, -8, and -9 was lost after ovariectomy, and only AQP9 immunoreactivity was restored after estradiol and/or progesterone treatments. The recovery of AQP9 reactivity after ovariectomy correlated with increased mRNA and protein levels after treatment with estradiol alone or progesterone administration after estradiol priming. Interestingly, progesterone administration after progesterone priming also induced AQP9 expression but without a change in mRNA levels. Levels of AQP9 varied along the estrous cycle with their highest levels during proestrus and estrus. These results indicate that steroid hormones regulate AQP9 expression at the mRNA and protein level and that other ovarian signals are involved in the expression of AQP5 and -8. Thus hormonal regulation of the type and quantity of water channels in this epithelium might control water transport in the oviductal lumen.
The α2-isoform of Na-K-ATPase mediates ouabain-induced hypertension in mice and increased vascular contractility in vitro
Authors: Dostanic Iva , Paul Richard J. , Lorenz John N. , Theriault Steven , Van Huysse James W. , Lingrel Jerry B.
Published: January 2005

Although ouabain is known to induce hypertension, the mechanism of how this cardiac glycoside affects blood pressure is uncertain. The present study demonstrates that the α2-isoform of the Na-K-ATPase mediates the pressor effects of ouabain in mice. To accomplish this, we analyzed the effect of ouabain on blood pressure in wild-type mice, where the α2-isoform is sensitive to ouabain, and genetically engineered mice expressing a ouabain-insensitive α2-isoform of the Na-K-ATPase. Thus differences in the response to ouabain between these two genotypes can only be attributed to the α2-isoform of Na-K-ATPase. As the α1-isoform is naturally resistant to ouabain in rodents, it will not be inhibited by ouabain in either genotype. Whereas prolonged administration of ouabain increased levels of ouabain in serum from both wild-type and targeted animals, hypertension developed only in wild-type mice. In addition, bolus intravenous infusion of ouabain increased the systolic, mean arterial, and left ventricular blood pressure in only wild-type anesthetized mice. In vitro, ouabain increased vascular tone and thereby phenylephrine-induced contraction of the aorta in intact and endothelium-denuded wild-type mice but in α2-resistant mice. Ouabain also increased the magnitude of the spontaneous contractions of portal vein and the basal tone of the intact aorta from only wild-type mice. The increase in aortic basal tone was dependent on the presence of endothelium. Our studies also demonstrate that the α2-isoform of Na-K-ATPase mediates the ouabain-induced increase in vascular contractility. This could play a role in the development and maintenance of ouabain-induced hypertension.
Mitochondrial KATPchannels in hindlimb remote ischemic preconditioning of skeletal muscle against infarction
Authors: Moses Michael A. , Addison Patrick D. , Neligan Peter C. , Ashrafpour Homa , Huang Ning , Zair Murtuza , Rassuli Alispasha , Forrest Christopher R. , Grover Gary J. , Pang Cho Y.
Published: January 2005

We previously demonstrated in the pig that instigation of three cycles of 10 min of occlusion and reperfusion in a hindlimb by tourniquet application (∼300 mmHg) elicited protection against ischemia-reperfusion injury (infarction) in multiple distant skeletal muscles subsequently subjected to 4 h of ischemia and 48 h of reperfusion, but the mechanism was not studied. The aim of this project was to test our hypothesis that mitochondrial ATP-sensitive potassium (KATP) (mKATP) channels play a central role in the trigger and mediator mechanisms of hindlimb remote ischemic preconditioning (IPC) of skeletal muscle against infarction in the pig. We observed in the pig that hindlimb remote IPC reduced the infarct size of latissimus dorsi (LD) muscle flaps (8 × 13 cm) from 45 ± 2% to 22 ± 3% ( n = 10; P < 0.05). The nonselective KATPchannel inhibitor glibenclamide (0.3 mg/kg) or the selective mKATPchannel inhibitor 5-hydroxydecanoate (5-HD, 5 mg/kg), but not the selective sarcolemmal KATP(sKATP) channel inhibitor HMR-1098 (3 mg/kg), abolished the infarct-protective effect of hindlimb remote IPC in LD muscle flaps ( n = 10, P < 0.05) when these drugs were injected intravenously at 10 min before remote IPC. In addition, intravenous bolus injection of glibenclamide (1 mg/kg) or 5-HD (10 mg/kg) at the end of hindlimb remote IPC also abolished the infarct protection in LD muscle flaps ( n = 10; P < 0.05). Furthermore, intravenous injection of the specific mKATPchannel opener BMS-191095 (2 mg/kg) at 10 min before 4 h of ischemia protected the LD muscle flap against infarction to a similar extent as hindlimb remote IPC, and this infarct-protective effect of BMS-191095 was abolished by intravenous bolus injection of 5-HD (5 mg/kg) at 10 min before or after intravenous injection of BMS-191095 ( n = 10; P < 0.05). The infarct protective effect of BMS-191095 was associated with a higher muscle content of ATP at the end of 4 h of ischemia and a decrease in muscle neutrophilic myeloperoxidase activity at the end of 1.5 h of reperfusion compared with the time-matched control ( n = 10, P < 0.05). These observations led us to conclude that mKATPchannels play a central role in the trigger and mediator mechanisms of hindlimb remote IPC of skeletal muscle against infarction in the pig, and the opening of mKATPchannels in ischemic skeletal muscle is associated with an ATP-sparing effect during sustained ischemia and attenuation of neutrophil accumulation during reperfusion.
Effect of chronic hypoxia on cholinergic chemotransmission in rat carotid body
Authors: He L. , Dinger B. , Fidone S.
Published: January 2005

Current views suggest that oxygen sensing in the carotid body occurs in chemosensory type I cells, which excite synaptically apposed chemoafferent nerve terminals in the carotid sinus nerve (CSN). Prolonged exposure in a low-oxygen environment [i.e., chronic hypoxia (CH)] elicits an elevated stimulus-evoked discharge in chemoreceptor CSN fibers (i.e., increased chemosensitivity). In the present study, we evaluated cholinergic chemotransmission in the rat carotid body in an effort to test the hypothesis that CH enhances ACh-mediated synaptic activity between type I cells and chemoafferent nerve terminals. Animals were exposed in a hypobaric chamber (barometric pressure = 380 Torr) for 9–22 days before evaluation of chemoreceptor activity using an in vitro carotid body/CSN preparation. Nerve activity evoked by ACh was significantly larger ( P < 0.01) after CH, suggesting increased expression of cholinergic receptors. Approximately 80% of the CSN impulse activity elicited by ACh (100- or 1,000-μg bolus) in both normal and CH preparations was blocked by the specific nicotinic receptor antagonist mecamylamine (100 μM). CSN activity elicited by acute hypoxia or hypercapnia in normal preparations was likewise blocked (≥80%) in the presence of 100 μM mecamylamine, but after CH the enhanced CSN activity elicited by acute hypoxia or hypercapnia was not reduced in the presence of 100 or 500 μM mecamylamine. A muscarinic receptor antagonist, atropine (10 μM), and a specific nicotinic receptor α7 subunit antagonist, methyllycaconatine (50 nM), blocked ∼50% of the hypoxia-evoked activity in normal preparations but were ineffective after CH. Prolonged exposure to hypoxia appears to dramatically alter chemotransmission in the carotid body, and may induce alternative neurotransmitter mechanisms and/or electrical coupling between type I cells and chemoafferent nerve terminals.
Time course of molecular responses of human skeletal muscle to acute bouts of resistance exercise
Authors: Bickel C. Scott , Slade Jill , Mahoney Ed , Haddad Fadia , Dudley Gary A. , Adams Gregory R.
Published: January 2005

Resistance exercise (RE) training, designed to induce hypertrophy, strives for optimal activation of anabolic and myogenic mechanisms to increase myofiber size. Clearly, activation of these mechanisms must precede skeletal muscle growth. Most mechanistic studies of RE have involved analysis of outcome variables after many training sessions. This study measured molecular level responses to RE on a scale of hours to establish a time course for the activation of myogenic mechanisms. Muscle biopsy samples were collected from nine subjects before and after acute bouts of RE. The response to a single bout was assessed at 12 and 24 h postexercise. Further samples were obtained 24 and 72 h after a second exercise bout. RE was induced by neuromuscular electrical stimulation to generate maximal isometric contractions in the muscle of interest. A single RE bout resulted in increased levels of mRNA for IGF binding protein-4 (84%), MyoD (83%), myogenin (∼3-fold), cyclin D1 (50%), and p21-Waf1 (16-fold), and a transient decrease in IGF-I mRNA (46%). A temporally conserved, significant correlation between myogenin and p21 mRNA was observed ( r = 0.70, P ≤ 0.02). The mRNAs for mechano-growth factor, IGF binding protein-5, and the IGF-I receptor were unchanged by RE. Total skeletal muscle RNA was increased 72 h after the second serial bout of RE. These results indicate that molecular adaptations of skeletal muscle to loading respond in a very short time. This approach should provide insights on the mechanisms that modulate adaptation to RE and may be useful in evaluating RE training protocol variables with high temporal resolution.
Effects of angiotensin II on autonomic components of nasopharyngeal stimulation in male conscious rabbits
Authors: Mousa Tarek M. , Gao Lie , Cornish Kurtis G. , Zucker Irving H.
Published: January 2005

Angiotensin II (ANG II) is known to activate central sympathetic neurons. In this study we determined the effects of ANG II on the autonomic components of the cardiovascular responses to stimulation of nasopharyngeal receptors with cigarette smoke. Experiments were carried out in conscious New Zealand White rabbits instrumented to record arterial pressure and heart rate. Rabbits were exposed to 50 ml of cigarette smoke before and after subcutaneous osmotic minipump delivery of ANG II at a dose of 50 ng·kg−1·min−1 for 1 wk in one group and intracerebroventricular (icv) infusion at a dose of 100 pmol/min for 1 h in a second group. The responses were compared before and after heart rate was controlled by pacing. Autonomic components were evaluated by intravenous administration of atropine methyl bromide (0.2 mg/kg) and prazosin (0.5 mg/kg). ANG II given either systemically or icv significantly blunted the pressor response to smoke ( P < 0.05) when the bradycardic response was prevented. This blunted response was not due to an absolute increase in baseline blood pressure after ANG II infusion (71.64 ± 11.6 vs. 92.1 ± 19.8 mmHg; P < 0.05) because normalization of blood pressure with sodium nitroprusside to pre-ANG II levels also resulted in a significantly blunted pressor response to smoke. The effect of smoke was α1-adrenergic receptor-mediated because it was essentially abolished by prazosin in both the pre- and the post-ANG II states ( P < 0.05). These results suggest that elevations in central ANG II reduce the sympathetic response to smoke in conscious rabbits. This effect may be due to an augmentation of baseline sympathetic outflow and a reduction in reflex sensitivity similar to the effect of ANG II on baroreflex function.
Conjugating Motion
Authors: Weissert Thomas
Published: January 2005

Our conception of time changed from the lofty absolute coordinate of the classical paradigm to merely a connection between local reference frames, thanks to the Special Theory of Relativity, a connection that depends on knowing the relative velocity between frames, and that entails knowing local velocities. We measure local velocities using a clock that cannot give us precise time because knowing time depends solely on knowing the process that we use to generate time. In the case of both macroscopic and microscopic clocks, an intrinsic uncertainty blocks us from knowing both the dynamic and static states of the variables involved. By focusing on the conceptual process that we use to describe physical systems, we can approach a common epistemology of both microscopic and macroscopic dynamical systems. We find that both systems of description require that we inser t time implicitly into the formalism to account for the conservation of identity through our own psychological experience of time. Although we cannot define exactly the nature of the conserved identity, we can describe its evolution with pairs of conjugate variables, one tracking the static state and one the dynamic state. Uncertainty extends from our conceiving system into our descriptive theories. An epistemology that emphasizes the balance between the conjugate variables as they serve to describe the evolution of the identity provides a common ground on which to discuss both the Heisenberg uncertainty principle of quantum mechanics and the bounded randomness of a deterministic macroscopic system. We have seen time go from a global to a local phenomenon, and perhaps now we must allow time to become an epiphenomenon even at the local level, one that we ourselves insert to account for the continuity of our own conscious experience.
Memory of Futures
Authors: Adam Barbara
Published: January 2005

We think of memories as being focused on the past. However, our ability to move freely in the temporal realm of past, present and future is far more complex and sophisticated than commonsense would suggest. In this paper I am concerned with our capacity to produce and extend ourselves into the far future, for example through nuclear power or the genetic modification of food, on the one hand, and our inability to know the potential, diverse and multiple outcomes of this technologically constituted futurity, on the other. I focus on this discrepancy in order to explore what conceptual tools are available to us to take account of long-term futures produced by the industrial way of life. And I identify some historical approaches to the future on the assumption that the past may well hold vital clues for today's dilemma, hence my proposal to engage in 'memory of futures'. I conclude by considering the potential of 'memory aids for the future' as a means to better encompass in contemporary concerns the long-term futures of our making.
Memory, Consciousness, and Time in Nabokov's Lolita
Authors: Hasty Olga
Published: January 2005

In his "Confession of a White Widowed Male," Humbert Humbert, the fictional narrator of Nabokov's Lolita, writes: "I am not concerned with so-called 'sex' at all." In the context of a narrative that centers on his pedophilia, it is difficult to take this assertion seriously. Yet if we do, we come to appreciate that Humbert's sexuality is emblematic of a distinctly modernist response to the perennial question of how to counter temporal passage and the inevitable loss attendant on it. Nabokov's configuration of memory, consciousness, and time in Lolita shows how passage itself might be engaged in the creative enterprise of resisting loss.