bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of New Formalin-Detoxified Botulinum Neurotoxin Toxoids
Authors: Keller James E.
Published: July 2008

Antigenicities of several formalin-detoxified botulinum neurotoxin preparations were measured by inhibition and sandwich enzyme-linked immunosorbent assay (ELISA), and immunogenicity was studied in mice. The toxoids were derived primarily from the serotype A 150-kDa neurotoxin protein, while one toxoid was derived from the naturally occurring 900-kDa toxin-hemagglutinin complex. Antigenicity was severely compromised in two commercially available toxoids. A variety of new toxoids were synthesized in-house by optimizing formaldehyde reaction conditions. Three of the resulting toxoids were found to be antigenically identical to the native toxin, as measured by inhibition ELISA, in spite of showing a reduction of toxicity by more than 100,000-fold. Sandwich ELISAs indicated that the in-house toxoids were two- to threefold less antigenic than the neurotoxin compared to commercial toxoids, which were about 100-fold less antigenic. Mice were immunized twice, on day 0 and day 14. By day 28, relatively high toxin-specific immunoglobulin G (IgG) titers were detected in animals that had received any of the in-house toxoids, with greater than 99% being IgG1 and the remainder being IgG2. These immunized mice remained asymptomatic after being challenged with 50 to 1,000,000 50% lethal dose (LD50) units of the 900-kDa neurotoxin. In contrast, animals immunized with several different batches of commercially available toxoids did not develop measurable toxin-specific antibody titers. However, these mice survived neurotoxin challenges with 2 LD50units but died when challenged with 6 LD50units. Neutralizing titers measured from pools of sera generated with the in-house toxoid preparations ranged from 2.5 to 5 U/ml. In terms of predicting immunogenicity, inhibition ELISAs comparing each formalin toxoid to the parent toxin provided good insight for screening the new toxoids as well as for estimating their relative in vivo potencies. Inhibition ELISA data indicate that those toxoids that most closely resemble the native toxin are highly immunogenic and protective. The superior quality of these new toxoids makes them useful tools for continued use in ELISA development and for antitoxin production.
Matched Case-Control Study of Effectiveness of Live, Attenuated S
79
Mumps Virus Vaccine against Clinical Mumps
Authors: Fu Chuanxi , Liang Jianhua , Wang Ming
Published: July 2008

Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live, attenuated S
79
mumps virus vaccine has been licensed for pediatric use since 1990. There has been no assessment of its efficacy. Thus, the objective of this study was to determine the effectiveness of live, attenuated S
79
mumps virus vaccine against clinical mumps. Cases were selected from the China Information System for Disease Control and Prevention during September 2004 to March 2005. Each case was matched to a control by gender, age, and area of residency. In all, 469 cases and 469 controls were enrolled in the study. Vaccination information was obtained from the Children's EPI Administrative Computerized System. Vaccine effectiveness (VE) was calculated for one or two doses of S
79
vaccine, with 95% confidence intervals (CI). VE of mumps virus vaccine for one dose versus none was protection of 86.0% (95% CI, 77.2% to 91.5%) of recipients, and VE was much higher in the first 4 years than in the 5 to 12 years after vaccination. The S
79
vaccine can effectively prevent clinical mumps, and a second dose of mumps virus vaccine is necessary for the protection of children in China.
Gender-Dependent HLA-DR-Restricted Epitopes Identified from Herpes Simplex Virus Type 1 Glycoprotein D
Authors: Zhang Xiuli , Castelli Florence A. , Zhu Xiaoming , Wu Michele , Maillère Bernard , BenMohamed Lbachir
Published: July 2008

In recent clinical trials, a herpes simplex virus (HSV) recombinant glycoprotein D (gD) vaccine was more efficacious in woman than in men. Here we report six HLA-DR-restricted T-cell gD epitope peptides that bind to multiple HLA-DR (DR1, DR4, DR7, DR13, DR15, and DRB5) molecules that represent a large proportion of the human population. Four of these peptides recalled naturally primed CD4+T cells in up to 45% of the 46 HSV-seropositive, asymptomatic individuals studied. For the gD49-82, gD77-104, and gD121-152peptides, the CD4+T-cell responses detected in HSV-seropositive, asymptomatic women were higher and more frequent than the responses detected in men. Immunization of susceptible DRB1*0101 transgenic mice with a mixture of three newly identified, gender-dependent, immunodominant epitope peptides (gD49-82, gD77-104, and gD121-152) induced a gender- and CD4+T-cell-dependent immunity against ocular HSV type 1 challenge. These results revealed a gender-dependent T-cell response to a discrete set of gD epitopes and suggest that while a T-cell epitope-based HSV vaccine that targets a large percentage of the human population may be feasible with a limited number of immunodominant promiscuous HLA-DR-restricted epitopes, gender should be taken into account during evaluations of such vaccines.
High-Level Antigen Expression and Sustained Antigen Presentation in Dendritic Cells Nucleofected with Wild-Type Viral mRNA but Not DNA
Authors: Melhem Nada M. , Gleason Sherrianne M. , Liu Xiang Dong , Barratt-Boyes Simon M.
Published: July 2008

Dendritic cells (DC) are potent antigen-presenting cells that hold promise as cell-based therapeutic vaccines for infectious diseases and cancer. Ideally, DC would be engineered to express autologous viral or tumor antigens to ensure the presentation of relevant antigens to host T cells in vivo; however, expression of wild-type viral genes in primary cell lines can be problematic. Nucleofection is an effective means of delivering transgenes to primary cell lines, but its use in transfecting DNA or mRNA into DC has not been widely investigated. We show that nucleofection is a superior means of transfecting human and monkey monocyte-derived DC with DNA and mRNA compared to lipofection and conventional electroporation. However, the delivery of DNA and mRNA had significantly different outcomes in transfected DC. DC nucleofected with DNA encoding green fluorescent protein (GFP) had poor antigen expression and viability and were refractory to maturation with CD40 ligand. In contrast, >90% of DC expressed uniform and high levels of GFP from 3 h to 96 h postnucleofection with mRNA while maintaining a normal maturation response to CD40 ligation. Monkey DC nucleofected with wild-type, non-codon-optimized mRNA encoding simian immunodeficiency virus Gag stimulated robust antigen-specific effector T-cell responses at 24 h and 48 h postnucleofection, reflecting sustained antigen presentation in transfected DC, whereas no detectable T-cell response was noted when DC were nucleofected with DNA encoding the same Gag sequence. These data indicate that mRNA nucleofection may be an optimal means of transfecting DC with autologous tumor or viral antigen for DC-based immunotherapy.
Use of GRA6-Derived Synthetic Polymorphic Peptides in an Immunoenzymatic Assay To Serotype
Toxoplasma gondii
in Human Serum Samples Collected from Three Continents
Authors: Sousa Susana , Ajzenberg Daniel , Vilanova Manuel , Costa José , Dardé Marie-Laure
Published: July 2008

Serotyping is a simple typing method that consists of an immunoenzymatic assay (enzyme-linked immunosorbent assay [ELISA]) using synthetic polymorphic peptides derived from
Toxoplasma gondii
antigens. We developed a new ELISA based on GRA6 C-terminal polymorphic peptides. Serum samples from 41 human infections due to 23 archetypal (type I, II, or III) and 18 nonarchetypal strains were selected in order to validate this approach. For 20 out of the 23 archetypal infections, there was a clear correlation between microsatellite genotype and GRA6 serotyping. All infections due to nonarchetypal strains were misclassified as archetypal strain infections. The GRA6 C-terminal peptides from these strains were analyzed to explain this misclassification. A second group of 455 patients with acute and chronic toxoplasmosis due to unknown genotypes from different European, African, and Latin American countries were included in this study, and the strain type predicted by this method. The results suggest that serotyping is a promising method for typing strains, although limitations exist for African and South American strains as a consequence of higher peptide polymorphism. Other peptides from different markers must be studied in order to discriminate archetypal from nonarchetypal strains.
Circulating 20S Proteasome Levels in Patients with Mixed Connective Tissue Disease and Systemic Lupus Erythematosus
Authors: Majetschak Matthias , Perez Magdalena , Sorell Luis T. , Lam Janet , Maldonado Marcos E. , Hoffman Robert W.
Published: July 2008

The associations of circulating 20S proteasomes (c20S) with clinical and serologic disease indices in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) are unknown. We present the initial report that c20S levels are elevated in MCTD and correlate with clinically relevant changes in disease activity in SLE and MCTD.
Assessment of
Aspergillus
-Specific T Cells for Diagnosis of Invasive Aspergillosis in a Leukemic Child with Liver Lesions Mimicking Hepatosplenic Candidiasis
Authors: Potenza Leonardo , Barozzi Patrizia , Rossi Giulio , Palazzi Giovanni , Vallerini Daniela , Riva Giovanni , Cellini Monica , Morselli Monica , Volzone Francesco , Venturelli Claudia , Quadrelli Chiara , Di Pancrazio Luciana , Cano Maria Carmen , Paolucci Paolo , Torelli Giuseppe , Luppi Mario
Published: July 2008

A child with acute myeloid leukemia presented with multiple liver lesions mimicking hepatosplenic candidiasis during the neutropenic phase following the induction chemotherapy. All the available diagnostic tools showed repeatedly negative results, including galactomannan. An enzyme-linked immunospot (ELISPOT) assay showed a high number of
Aspergillus
-specific T cells producing interleukin-10 [TH2(IL-10)] and a low number of
Aspergillus
-specific T cells producing gamma interferon [TH1(IFN-γ)], revealing invasive aspergillosis (IA) before the confirmatory biopsy. A progressive skewing from the predominance of TH2(IL-10) to a predominance of TH1(IFN-γ) was observed close to the complete resolution of the infection and foreshadowed the outcome. The ELISPOT assay holds promise for diagnosing pediatric IA.
Dynamics and Determinants of
Staphylococcus aureus
Carriage in Infancy: the Generation R Study
Authors: Lebon Ankie , Labout Joost A. M. , Verbrugh Henri A. , Jaddoe Vincent W. V. , Hofman Albert , van Wamel Willem , Moll Henriette A. , van Belkum Alex
Published: July 2008

Serial nasal swabs were collected at the ages of 1.5, 6, and 14 months from 443 infants in the Generation R Study. The objective was to study the dynamics and determinants of
Staphylococcus aureus
nasal carriage in the first year of life. The prevalence of
S. aureus
carriage decreased in the first year of life, from 52.1% at the age of 1.5 months to 12.9% at 14 months. Persistent carriage, defined as continuous carriage of the same
S. aureus
strain at the three sampling moments, was rarely detected in early infancy.
Detection of Group B Streptococci in Lim Broth by Use of Group B
Streptococcus
Peptide Nucleic Acid Fluorescent In Situ Hybridization and Selective and Nonselective Agars
Authors: Montague Naomi S. , Cleary Timothy J. , Martinez Octavio V. , Procop Gary W.
Published: July 2008

The sensitivity, specificity, and positive and negative predictive values for the detection of group B streptococci from Lim enrichment broth with sheep blood agar (SBA), with selective
Streptococcus
agar (SSA), and by a peptide nucleic acid fluorescent in situ hybridization (PNA FISH) assay were as follows: for culture on SBA, 68.4%, 100%, 100%, and 87.9%, respectively; for culture on SSA, 85.5%, 100%, 100%, and 94.1%, respectively; and for the PNA FISH assay, 97.4%, 98.3%, 96.1%, and 98.9%, respectively.
Basal Budding and Replication of the Murine Leukemia Virus Are Independent of the Gag L Domains
Authors: Sabo Yosef , Laham-Karam Nihay , Bacharach Eran
Published: July 2008

Moloney murine leukemia virus (MMuLV) Gag protein contains three identified late (L) domains, PPPY, YPAL, and PSAP, which are thought to interact with the endosomal sorting machinery to assist budding. We created single and combined L-domain mutants in all permutations and tested the resulting clones for budding and replication. Budding and replication of all viruses with mutated PPPY were greatly reduced; however, the basal replication level was retained, demonstrated by the slow spread of the viruses in culture. Mutations in PSAP or YPAL did not affect budding or spreading, demonstrating that these two motifs are dispensable for efficient MMuLV replication. Furthermore, the basal budding level was maintained following inhibition of endosomal sorting machinery, emphasizing that the basal budding of MMuLV is independent of this machinery.
Adenovirus IVa2 Protein Binds ATP
Authors: Ostapchuk Philomena , Hearing Patrick
Published: July 2008

IVa2 is an essential, multifunctional protein of adenovirus (Ad) supporting packaging of the viral genome into the capsid, assisting in assembly of the capsid, and activating Ad late transcription. A comparison of IVa2 protein sequences from different species of
Adenoviridae
shows conserved motifs associated with binding and hydrolysis of ATP (Walker A and B motifs). ATPases are essential proteins of bacteriophage packaging motors, and such activity may be required for Ad packaging. Results presented here show that the Ad2 IVa2 protein binds ATP in vitro and that sequences in the Walker A and B motifs are necessary for this activity.
PPEY Motif within the Rabies Virus (RV) Matrix Protein Is Essential for Efficient Virion Release and RV Pathogenicity
Authors: Wirblich Christoph , Tan Gene S. , Papaneri Amy , Godlewski Peter J. , Orenstein Jan Marc , Harty Ronald N. , Schnell Matthias J.
Published: July 2008

Late (L) domains containing the highly conserved sequence PPXY were first described for retroviruses, and later research confirmed their conservation and importance for efficient budding of several negative-stranded RNA viruses.
Rabies virus
(RV), a member of the
Rhabdoviridae
family, contains the sequence PPEY (amino acids 35 to 38) within the N terminus of the matrix (M) protein, but the functions of this potential L-domain in the viral life cycle, viral pathogenicity, and immunogenicity have not been established. Here we constructed a series of recombinant RVs containing mutations within the PPEY motif and analyzed their effects on viral replication and RV pathogenicity. Our results indicate that the first proline at position 35 is the most important for viral replication, whereas P36 and Y38 have a lesser but still noticeable impact. The reduction in viral replication was most likely due to inhibition of virion release, because initially no major impact on RV RNA synthesis was observed. In addition, results from electron microscopy demonstrated that the M4A mutant virus (PPEY→SAEA) displayed a more cell-associated phenotype than that of wild-type RV. Furthermore, all mutations within the PPEY motif resulted in reduced spread of the recombinant RVs as indicated by a reduction in focus size. Importantly, recombinant PPEY L-domain mutants were highly attenuated in mice yet still elicited potent antibody responses against RV G protein that were as high as those observed after infection with wild-type virus. Our data indicate that the RV PPEY motif has L-domain activity essential for efficient virus production and pathogenicity but is not essential for immunogenicity and thus can be targeted to increase the safety of rabies vaccine vectors.
Structure of Flexible Filamentous Plant Viruses
Authors: Kendall Amy , McDonald Michele , Bian Wen , Bowles Timothy , Baumgarten Sarah C. , Shi Jian , Stewart Phoebe L. , Bullitt Esther , Gore David , Irving Thomas C. , Havens Wendy M. , Ghabrial Said A. , Wall Joseph S. , Stubbs Gerald
Published: July 2008

Flexible filamentous viruses make up a large fraction of the known plant viruses, but in comparison with those of other viruses, very little is known about their structures. We have used fiber diffraction, cryo-electron microscopy, and scanning transmission electron microscopy to determine the symmetry of a potyvirus, soybean mosaic virus; to confirm the symmetry of a potexvirus, potato virus X; and to determine the low-resolution structures of both viruses. We conclude that these viruses and, by implication, most or all flexible filamentous plant viruses share a common coat protein fold and helical symmetry, with slightly less than 9 subunits per helical turn.
A Hyperfusogenic F Protein Enhances the Oncolytic Potency of a Paramyxovirus Simian Virus 5 P/V Mutant without Compromising Sensitivity to Type I Interferon
Authors: Gainey Maria D. , Manuse Mary J. , Parks Griffith D.
Published: July 2008

Viral fusogenic membrane proteins have been proposed as tools to increase the potency of oncolytic viruses, but there is a need for mechanisms to control the spread of fusogenic viruses in normal versus tumor cells. We have previously shown that a mutant of the paramyxovirus simian virus 5 (SV5) that harbors mutations in the P/V gene from the canine parainfluenza virus (P/V-CPI
−
) is a potent inducer of type I interferon (IFN) and apoptosis and is restricted for spread through normal but not tumor cells in vitro. Here, we have used the cytopathic P/V-CPI
−
as a backbone vector to test the hypothesis that a virus expressing a hyperfusogenic glycoprotein will be a more effective oncolytic vector but will retain sensitivity to IFN. A P/V mutant virus expressing an F protein with a glycine-to-alanine substitution in the fusion peptide (P/V-CPI
−
-G3A) was more fusogenic than the parental P/V-CPI
−
mutant. In two model prostate tumor cell lines which are defective in IFN production (LNCaP and DU145), the hyperfusogenic P/V-CPI
−
-G3A mutant had normal growth properties at low multiplicities of infection and was more effective than the parental P/V-CPI
−
mutant at cell killing in vitro. However, in PC3 cells which produce and respond to IFN, the hyperfusogenic P/V-CPI
−
-G3A mutant was attenuated for growth and spread. Killing of PC3 cells was equivalent between the parental P/V-CPI
−
mutant and the hyperfusogenic P/V-CPI
−
-G3A mutant. In a nude mouse model using LNCaP cells, the hyperfusogenic P/V-CPI
−
-G3A mutant was more effective than P/V-CPI
−
at reducing tumor burden. In the case of DU145 tumors, the two vectors based on P/V-CPI
−
were equally effective at limiting tumor growth. Together, our results provide proof of principle that a cytopathic SV5 P/V mutant can serve as an oncolytic virus and that the oncolytic effectiveness of P/V mutants can be enhanced by a fusogenic membrane protein without compromising sensitivity to IFN. The potential advantages of SV5-based oncolytic vectors are discussed.
Gag-Specific Cytotoxic T-Lymphocyte-Based Control of Primary Simian Immunodeficiency Virus Replication in a Vaccine Trial
Authors: Kawada Miki , Tsukamoto Tetsuo , Yamamoto Hiroyuki , Iwamoto Nami , Kurihara Kyoko , Takeda Akiko , Moriya Chikaya , Takeuchi Hiroaki , Akari Hirofumi , Matano Tetsuro
Published: July 2008

Gag-specific cytotoxic T lymphocytes (CTLs) exert strong suppressive pressure on human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication. However, it has remained unclear whether they can actually contain primary viral replication. Recent trials of prophylactic vaccines inducing virus-specific T-cell responses have indicated their potential to confer resistance against primary SIV replication in rhesus macaques, while the immunological determinant for this vaccine-based viral control has not been elucidated thus far. Here we present evidence implicating Gag-specific CTLs as responsible for the vaccine-based primary SIV control. Prophylactic vaccination using a Gag-expressing Sendai virus vector resulted in containment of SIVmac239 challenge in all rhesus macaques possessing the major histocompatibility complex (MHC) haplotype
90-120-Ia
. In contrast,
90-120-Ia
-positive vaccinees failed to contain SIVs carrying multiple
gag
CTL escape mutations that had been selected, at the cost of viral fitness, in SIVmac239-infected
90-120-Ia
-positive macaques. These results show that Gag-specific CTL responses do play a crucial role in the control of wild-type SIVmac239 replication in vaccinees. This study implies the possibility of Gag-specific CTL-based primary HIV containment by prophylactic vaccination, although it also suggests that CTL-based AIDS vaccine efficacy may be abrogated in viral transmission between MHC-matched individuals.
Association of the Cellular Coactivator HCF-1 with the Golgi Apparatus in Sensory Neurons
Authors: Kolb Gaelle , Kristie Thomas M.
Published: July 2008

HCF-1 is a cellular transcriptional coactivator that is critical for mediating the regulated expression of the immediate-early genes of the alphaherpesviruses herpes simplex virus type 1 and varicella-zoster virus. HCF-1 functions, at least in part, by modulating the modification of nucleosomes at these viral promoters to reverse cell-mediated repressive marks and promote activating marks. Strikingly, HCF-1 is specifically sequestered in the cytoplasm of sensory neurons where these viruses establish latency and is rapidly relocalized to the nucleus upon stimuli that result in viral reactivation. However, the analysis of HCF-1 in latently infected neurons and the protein's specific subcellular location have not been determined. Therefore, in this study, the localization of HCF-1 in unstimulated and induced latently infected sensory neurons was investigated and was found to be similar to that observed in uninfected mice, with a time course of induced nuclear accumulation that correlated with viral reactivation. Using a primary neuronal cell culture system, HCF-1 was localized to the Golgi apparatus in unstimulated neurons, a unique location for a transcriptional coactivator. Upon disruption of the Golgi body, HCF-1 was rapidly relocalized to the nucleus in contrast to other Golgi apparatus-associated proteins. The location of HCF-1 is distinct from that of CREB3, an endoplasmic reticulum-resident HCF-1 interaction partner that has been proposed to sequester HCF-1. The results support the model that HCF-1 is an important component of the viral latency-reactivation cycle and that it is regulated by association with a component that is distinct from the identified HCF-1 interaction factors.
Murine Coronavirus Mouse Hepatitis Virus Is Recognized by MDA5 and Induces Type I Interferon in Brain Macrophages/Microglia
Authors: Roth-Cross Jessica K. , Bender Susan J. , Weiss Susan R.
Published: July 2008

The coronavirus mouse hepatitis virus (MHV) induces a minimal type I interferon (IFN) response in several cell types in vitro despite the fact that the type I IFN response is important in protecting the mouse from infection in vivo. When infected with MHV, mice deficient in IFN-associated receptor expression (IFNAR−/−) became moribund by 48 h postinfection. MHV also replicated to higher titers and exhibited a more broad tissue tropism in these mice, which lack a type I IFN response. Interestingly, MHV induced IFN-β in the brains and livers, two main targets of MHV replication, of infected wild-type mice. MHV infection of primary cell cultures indicates that hepatocytes are not responsible for the IFN-β production in the liver during MHV infection. Furthermore, macrophages and microglia, but not neurons or astrocytes, are responsible for IFN-β production in the brain. To determine the pathway by which MHV is recognized in macrophages, IFN-β mRNA expression was quantified following MHV infection of a panel of primary bone marrow-derived macrophages generated from mice lacking different pattern recognition receptors (PRRs). Interestingly, MDA5, a PRR thought to recognize primarily picornaviruses, was required for recognition of MHV. Thus, MHV induces type I IFN in macrophages and microglia in the brains of infected animals and is recognized by an MDA5-dependent pathway in macrophages. These findings suggest that secretion of IFN-β by macrophages and microglia plays a role in protecting the host from MHV infection of the central nervous system.
Cell Cycle-Independent Expression of Immediate-Early Gene 3 Results in G
1
and G
2
Arrest in Murine Cytomegalovirus-Infected Cells
Authors: Wiebusch Lüder , Neuwirth Anke , Grabenhenrich Linus , Voigt Sebastian , Hagemeier Christian
Published: July 2008

The infectious cycle of human cytomegalovirus (HCMV) is intricately linked to the host's cell cycle. Viral gene expression can be initiated only in G
0
/G
1
phase. Once expressed, the immediate-early gene product IE2 prevents cellular DNA synthesis, arresting infected cells with a G
1
DNA content. This function is required for efficient viral replication in vitro. A prerequisite for addressing its in vivo relevance is the characterization of cell cycle-regulatory activities of CMV species for which animal models have been established. Here, we show that murine CMV (MCMV), like HCMV, has a strong antiproliferative capacity and arrests cells in G
1
. Unexpectedly, and in contrast to HCMV, MCMV can also block cells that have passed through S phase by arresting them in G
2
. Moreover, MCMV can also replicate in G
2
cells. This is made possible by the cell cycle-independent expression of MCMV immediate-early genes. Transfection experiments show that of several MCMV candidate genes, only immediate-early gene 3 (ie3), the homologue of HCMV IE2, exhibits cell cycle arrest activity. Accordingly, an MCMV ie3 deletion mutant has lost the ability to arrest cells in either G
1
or G
2
. Thus, despite interspecies variations in the cell cycle dependence of viral gene expression, the central theme of HCMV IE2-induced cell cycle arrest is conserved in the murine counterpart, raising the possibility of studying its physiological relevance at the level of the whole organism.
The Quality of Chimpanzee T-Cell Activation and Simian Immunodeficiency Virus/Human Immunodeficiency Virus Susceptibility Achieved via Antibody-Mediated T-Cell Receptor/CD3 Stimulation Is a Function of the Anti-CD3 Antibody Isotype
Authors: Bibollet-Ruche Frederic , McKinney Brett A. , Duverger Alexandra , Wagner Frederic H. , Ansari Aftab A. , Kutsch Olaf
Published: July 2008

While human immunodeficiency virus type 1 (HIV-1) infection is associated with hyperimmune activation and systemic depletion of CD4+T cells, simian immunodeficiency virus (SIV) infection in sooty mangabeys or chimpanzees does not exhibit these hallmarks. Control of immune activation is thought to be one of the major components that govern species-dependent differences in the disease pathogenesis. A previous study introduced the idea that the resistance of chimpanzees to SIVcpz infection-induced hyperimmune activation could be the result of the expression of select sialic acid-recognizing immunoglobulin (Ig)-like lectin (Siglec) superfamily members by chimpanzee T cells. Siglecs, which are absent on human T cells, were thought to control levels of T-cell activation in chimpanzees and were thus suggested as a cause for the pathogenic differences in the course of SIVcpz or HIV-1 infection. As in human models of T-cell activation, stimulation had been attempted using an anti-CD3 monoclonal antibody (MAb) (UCHT1; isotype IgG1), but despite efficient binding, UCHT1 failed to activate chimpanzee T cells, an activation block that could be partially overcome by MAb-induced Siglec-5 internalization. We herein demonstrate that anti-CD3 MAb-mediated chimpanzee T-cell activation is a function of the anti-CD3 MAb isotype and is not governed by Siglec expression. While IgG1 anti-CD3 MAbs fail to stimulate chimpanzee T cells, IgG2a anti-CD3 MAbs activate chimpanzee T cells in the absence of Siglec manipulations. Our results thus imply that prior to studying possible differences between human and chimpanzee T-cell activation, a relevant model of chimpanzee T cell activation needs to be established.
Two Regions within the Amino-Terminal Half of APOBEC3G Cooperate To Determine Cytoplasmic Localization
Authors: Stenglein Mark D. , Matsuo Hiroshi , Harris Reuben S.
Published: July 2008

APOBEC3G limits the replication of human immunodeficiency virus type 1, other retroviruses, and retrotransposons. It localizes predominantly to the cytoplasm of cells, which is consistent with a model wherein cytosolic APOBEC3G packages into assembling virions, where it exerts its antiviral effect by deaminating viral cDNA cytosines during reverse transcription. To define the domains of APOBEC3G that determine cytoplasmic localization, comparisons were made with APOBEC3B, which is predominantly nuclear. APOBEC3G/APOBEC3B chimeric proteins mapped a primary subcellular localization determinant to a region within the first 60 residues of each protein. A panel of 25 APOBEC3G mutants, each with a residue replaced by the corresponding amino acid of APOBEC3B, revealed that several positions within this region were particularly important, with Y19D showing the largest effect. The mislocalization phenotype of these mutants was only apparent in the context of the amino-terminal half of APOBEC3G and not the full-length protein, suggesting the existence of an additional localization determinant. Indeed, a panel of five single amino acid substitutions within the region from amino acids 113 to 128 had little effect by themselves but, in combination with Y19D, two substitutions—F126S and W127A—caused full-length APOBEC3G to redistribute throughout the cell. The critical localization-determining residues were predicted to cluster on a common solvent-exposed surface, suggesting a model in which these two regions of APOBEC3G combine to mediate an intermolecular interaction that controls subcellular localization.
Changes in punching shear design in Canadian standard CSA A23.3-04: a critical review
Authors: Gayed Ramez B. , Ghali Amin
Published: July 2008

Provisions of the 2004 version of the Canadian standard A23.3 related to punching shear design of reinforced concrete flat plates at their connections with columns are reviewed, with attention to the changes introduced in 2004. Revisions are proposed and justified.
Seismic performance of a full-scale, reinforced high-performance concrete building. Part II: Analytical study
Authors: Mousseau Sébastien , Paultre Patrick , Mazars Jacky
Published: July 2008

Full-scale tests provide valuable information on the characteristics of building structures that can be used to evaluate design methods, to calibrate modelling techniques, and to determine damage corresponding to loading levels. These tests are scarce due to the enormous requirements in testing space and specialized testing equipment. The seismic behaviour of a full-scale, two-storey, reinforced high-performance concrete building designed with moderate ductility detailing is evaluated by pseudo-dynamic testing, during which increasing seismic loads are applied, resulting in increasing levels of permanent damage to the structure. This paper presents the analytical predictions of the test results using a global force–displacement parameters approach and a refined approach, half-way between global modelling and finite element modelling, using force–strain parameters and damage mechanics principles. Identification of the parameters required to describe the response parameters are presented together with a description of the numerical procedures used in each approach. It is shown that the predictions are in good agreement with the test results. Advantages and disadvantages of each approach are highlighted in the context of performance-based analysis and design.
Double-angle shear connections with short outstanding legs
Authors: Gong Yanglin , Gillies Antony
Published: July 2008

This paper describes an experimental study on double-angle shear connections with a narrow outstanding leg width from 31 to 37 mm. When connection angles are welded to a supporting column with a face width less than 152 mm, a common practice is either to weld the angles to the column by flare bevel groove welds or shorten the outstanding legs to accommodate fillet welds. This practice reduces the rotational capacity of the connections; and therefore confirmation of this practice is required. Three groups, comprising 12 full-scale connection specimens, were tested. Each group consisted of four specimens having three, four, five, and six bolts, respectively. Group A used 9.5 mm thick angles and fillet welds, group B used 6.4 mm thick angles and fillet welds, and group C used 9.5 mm thick angles and flare bevel groove welds. The test results demonstrated that both rotational and shear capacities of the connections are satisfactory when either of the two details are used.
Semicontinuum analysis of shear-weak grillages
Authors: Jaeger Leslie G. , Bakht Baidar
Published: July 2008

Cellular bridges and voided slab bridges with large and frequently spaced circular voids undergo distortion of the cross section under nonuniform loads, which may have a significant effect on the load distribution characteristics of the bridge. For two-dimensional analysis of these bridges, it is usual to represent the transverse medium of the bridge as having finite shear rigidity. Up to the present time, the semicontinuum method of analysis did not have the capability of handling finite shear rigidity of the transverse medium. A modification is introduced in this paper through which it can now do so. It is shown that the proposed modifications consist of only minor changes to the set of equations of the earlier version of the method. By comparing the results of the proposed method with those obtained from grillage analysis, it is shown that the accuracy of the proposed method is equal to that of the grillage method, which has already been found by many researchers to be suitable for the analysis of shear-weak bridges. The paper also contains proposed modifications to the semicontinuum method so that it can handle finite shear rigidities of the longitudinal beams as well. Key words: analysis, bridges, load distribution, semicontinuum method, shear rigidity, shear-weak grillages, shear-weak plotes.
Axial stiffness of anchoring rods embedded in elastic media
Authors: Selvadurai A. P. S. , Rajapakse R. K. N. D.
Published: July 2008

This paper presents a theoretical evaluation of the axial stiffness characteristics of elastic rods partially embedded in elastic media. The novel analytical–numerical technique is based on an energy or variational scheme in which the deformation of the bar is specified by a function, which is indeterminate to within a set of unknown constants. A minimization of the potential energy of the bar–elastic medium system is used to determine these arbitrary constants. The numerical results presented illustrate the influence of the relative flexibility of the bar, its length-to-radius aspect ratio, etc. on its axial stiffness. Key words: anchor rods, load transfer, axial stiffness, variational methods, elastic piles, tapered bars.
Dépistage des embâcles de glace par analyse hydrométrique
Authors: El-Jabi N. , Sarraf S.
Published: July 2008

Ice jams amplify flooding problems in northern countries such as Canada. During spring flood, ice jams are often the cause of severe damages and affect considerably the production of hydroelectric power plants. This study presents a brief description of ice jams and the various types of analysis associated with this phenomenon. The effect of ice jams on the water level of 21 hydrometric stations in New Brunswick is investigated. Key words: ice jam, ice breakup, hydrometric analysis, New Brunswick, influenced level. [Journal translation]
Lakehead terminal elevators: aspects of their engineering history
Authors: Vervoort P.
Published: July 2008

Massive grain elevators have been a dominant feature of the waterfront at Thunder Bay since 1883 when the first terminal was under construction. The earliest terminal elevators built by the Canadian Pacific Railway were constructed in the wooden crib technique on a pile foundation. By the turn of the century, the inadequacies of the crib terminals forced engineers to experiment with new materials and new design concepts for terminal elevators. Steel, tile, and reinforced concrete all came into use for terminal elevator construction between 1898 and 1903. By 1910, the plan of the elevator had evolved from a single building into four separate structures. The appearance of the typical Lakehead terminal elevator today is the result of these engineering experiments which occurred at the end of the nineteenth century and in the early years of the twentieth. Key words: grain elevators, concrete construction, slip forms, formwork, bins, silos, timber construction, crib walls, cribs, steel construction.
Bearspaw Development: design and construction of a side-channel overflow spillway
Authors: Pildysh M. , Slopek R. J. , Nunn J. O. H. , Keys R. A.
Published: July 2008

An emergency spillway with a capacity of 1840 m3/s has been built to increase the spillway capacity of the 30-year-old Bearspaw Development so that it can safely pass the probable maximum flood. A unique aspect of the free-overflow, side-channel emergency spillway is the weir. This consists of an earthfill dyke with a cap and downstream facing of reinforced concrete. Comprehensive hydraulic model testing was undertaken to provide detailed design data and optimize the design of the emergency spillway. The overflow weir substructure is a zoned earthfill dyke with a 2 mm thick polyethylene membrane at the top of the impervious core to prevent frost heave of the concrete lining. The reinforced concrete lining of the spillway is required for erosion protection and is designed to withstand the hydrodynamic drag and uplift forces caused by flowing water as well as piezometric uplift pressures due to seepage. An extensive underdrainage system was installed to reduce uplift pressures under the lining. An unlined return channel excavated through overburden and rock conducts spill way discharges back to the river. This paper describes the model testing, design, and construction of the emergency spillway. Key words: spillway, overflow, weir, erosion, drainage, hydrodynamic, frost heave, membrane, revetment, model testing.
Interpretation and application of core test data in strength evaluation of existing concrete bridge structures
Authors: McIntyre M. , Scanlon A.
Published: July 2008

Compressive strength tests on concrete cores taken from existing bridge structures are often used as a tool in evaluating the strength of the existing structure. Some difficulties are, however, encountered in interpreting the result of these tests and incorporating appropriate values in the usual equations for determining strength of structural members. In this paper, relationships between core tests, cylinder tests, and in situ strength are reviewed based on data reported in the literature. Methods for incorporating core test data into a limit states design approach for strength evaluation are investigated. A method is proposed to convert data from compressive strength tests on cores into an equivalent design compressive strength that can be used in the normal design equations for strength. The method is applied to the analysis of an existing bridge for which core test data are available. Key words: concrete cores, reinforced concrete, bridges, tests, compressive strength, structural evaluation.
ADOPTION OF ADMINISTRATIVE INNOVATION WITHIN ORGANIZATION — AN EMPIRICAL STUDY OF TQM METAMORPHOSIS
Authors: TANNINEN KATI , JANTUNEN ARI , SAKSA JUHA-MATTI
Published: July 2008

Little research has been done on the adoption and implementation of administrative innovation and its diffusion within the organization. In our study we explore this in the context of Total Quality Management in a large, global company. The analysis is based on extensive historical data and in-depth interviews. Our findings highlight the role of internal change agents in the diffusion process within the firm. We also open up the dynamics of the adoption process and illustrate how the adopted administrative innovation is transformed during the adoption and implementation phases.
Aspirin induces gastric epithelial barrier dysfunction by activating p38 MAPK via claudin-7
Authors: Oshima Tadayuki , Miwa Hiroto , Joh Takashi
Published: July 2008

Tight junctions create a paracellular permeability barrier that is breached when nonsteroidal anti-inflammatory drugs cause gastrointestinal injury, including increased gastrointestinal permeability. However, the mechanism by which aspirin affects the function of gastric epithelial tight junctions is unknown. Thus, we examined the effect of aspirin on gastric mucosal barrier properties and tight junction organization using MKN28, a human gastric epithelial cell line that expresses claudin-3, claudin-4, claudin-7, zonula occludens (ZO)-1, and occludin, but not claudin-2 or claudin-5, as determined by immunoblot analysis and immunofluorescent staining. Aspirin (5 mM) treatment of MKN28 gastric epithelial monolayers significantly decreased transepithelial electrical resistance and increased dextran permeability. Both aspirin-mediated permeability and phosphorylation of p38 MAPK were significantly attenuated by SB-203580 (a p38 MAPK inhibitor) but not by U-0126 (a MEK1 inhibitor) or SP-600125 (a JNK inhibitor). Aspirin significantly decreased the quantity of claudin-7 protein produced by MKN28 cells but not the quantity of claudin-3, claudin-4, ZO-1, or occludin. The aspirin-induced decrease in claudin-7 protein was completely abolished by SB-203580 pretreatment. These results demonstrate, for the first time, that claudin-7 protein is important in aspirin-induced gastric barrier loss and that p38 MAPK activity mediates this epithelial barrier dysfunction.
Hypoxia stimulates pancreatic stellate cells to induce fibrosis and angiogenesis in pancreatic cancer
Authors: Masamune Atsushi , Kikuta Kazuhiro , Watanabe Takashi , Satoh Kennichi , Hirota Morihisa , Shimosegawa Tooru
Published: July 2008

Pancreatic cancer is characterized by excessive desmoplastic reaction and by a hypoxic microenvironment within the solid tumor mass. Chronic pancreatitis is also characterized by fibrosis and hypoxia. Fibroblasts in the area of fibrosis in these pathological settings are now recognized as activated pancreatic stellate cells (PSCs). Recent studies have suggested that a hypoxic environment concomitantly exists not only in pancreatic cancer cells but also in surrounding PSCs. This study aimed to clarify whether hypoxia affected the cell functions in PSCs. Human PSCs were isolated and cultured under normoxia (21% O2) or hypoxia (1% O2). We examined the effects of hypoxia and conditioned media of hypoxia-treated PSCs on cell functions in PSCs and in human umbilical vein endothelial cells. Hypoxia induced migration, type I collagen expression, and vascular endothelial growth factor (VEGF) production in PSCs. Conditioned media of hypoxia-treated PSCs induced migration of PSCs, which was inhibited by anti-VEGF antibody but not by antibody against hepatocyte growth factor. Conditioned media of hypoxia-treated PSCs induced endothelial cell proliferation, migration, and angiogenesis in vitro and in vivo. PSCs expressed several angiogenesis-regulating molecules including VEGF receptors, angiopoietin-1, and Tie-2. In conclusion, hypoxia induced profibrogenic and proangiogenic responses in PSCs. In addition to their established profibrogenic roles, PSCs might play proangiogenic roles during the development of pancreatic fibrosis, where they are subjected to hypoxia.
Intermittent access to preferred food reduces the reinforcing efficacy of chow in rats
Authors: Cottone Pietro , Sabino Valentina , Steardo Luca , Zorrilla Eric P.
Published: July 2008

Intermittent, extended access to preferred diets increases their intake. However, the effects of such access on the acceptance and reinforcing efficacy of otherwise satisfying alternatives is less known. To investigate the role of nonnutritional contributions to the hypophagia that follows removal of preferred food, male Wistar rats were fed a chow diet (Chow A/I), preferred to their regular chow (Chow), which was equally consumed under 1-choice conditions to an even more preferred chocolate-flavored, sucrose-rich diet (Preferred). Rats then learned to obtain Chow A/I pellets under a progressive ratio schedule of reinforcement and were assigned to two matched groups. Each week, one group ( n = 15) was diet-cycled, receiving Chow A/I for 5 days followed by the Preferred diet for 2 days. Controls received Chow A/I daily ( n = 14). Progressive ratio sessions were performed daily during the 5 days that all subjects received Chow A/I in the home cage. Across 5 wk, diet-cycled rats progressively ate less of the otherwise palatable Chow A/I diet. Hypophagia was not due to greater prior intake or weight gain, motor impairment, or facilitated satiation and was associated with changes in progressive ratio performance that suggested a reduced reinforcing efficacy of the Chow A/I diet in diet-cycled animals. By week 4, diet-cycled animals began to overeat the preferred diet, especially during the first 6 h of renewed access, resembling a deprivation effect. The results suggest that intermittent access to highly preferred food, as practiced by many restrained eaters, may progressively decrease the acceptability of less palatable foods, and may promote relapse to more rewarding alternatives.
Cardiovascular responses to peripheral chemoreflex activation and comparison of different methods to evaluate baroreflex gain in conscious mice using telemetry
Authors: Braga Valdir A. , Burmeister Melissa A. , Sharma Ram V. , Davisson Robin L.
Published: July 2008

Peripheral chemoreceptors located in the carotid bodies are the primary sensors of systemic hypoxia. Although the pattern of responses elicited by peripheral chemoreceptor activation is well established in rats, lambs, and rabbits, the cardiovascular responses to peripheral chemoreflex activation in conscious mice have not been delineated. Here we report that stimulation of peripheral chemoreceptors by potassium cyanide (KCN) in conscious mice elicits a unique biphasic response in blood pressure that is characterized by an initial and robust rise followed by a decrease in blood pressure, which is accompanied by a marked reduction in heart rate. The depressor and bradycardic responses to KCN were abolished by muscarinic receptor blockade with atropine, and the pressor response was abolished by α-adrenergic receptor blockade with prazosin, suggesting that vagal and sympathetic drive to the heart and sympathetic drive to the vasculature mediate these cardiovascular responses. These studies characterized the chemoreflex in conscious mice and established the reliability of using them for studying hypoxia-related diseases such as obstructive sleep apnea. In another series of experiments, two methods for analyzing baroreflex sensitivity were compared: the classical pharmacological approach using phenylephrine and sodium nitroprusside (i.e., the Oxford technique) or the sequence method for analyzing spontaneous baroreflex activity. Our findings indicate that both methods are reliable, and the sequence method certainly has its benefits as a predictive tool in the context of long-term noninvasive studies using telemetry. However, for absolute determination of baroreflex function, analysis of spontaneous baroreflex activity should be complemented by the classical pharmacological method.