bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein-Protein Interactions in the Complex between the Enhancer Binding Protein NIFA and the Sensor NIFL from
Azotobacter vinelandii
Authors: Money Tracy , Barrett Jason , Dixon Ray , Austin Sara 
Published: July 2002

ABSTRACT

The enhancer binding protein NIFA and the sensor protein NIFL from
Azotobacter vinelandii
comprise an atypical two-component regulatory system in which signal transduction occurs via complex formation between the two proteins rather than by the phosphotransfer mechanism, which is characteristic of orthodox systems. The inhibitory activity of NIFL towards NIFA is stimulated by ADP binding to the C-terminal domain of NIFL, which bears significant homology to the histidine protein kinase transmitter domains. Adenosine nucleotides, particularly MgADP, also stimulate complex formation between NIFL and NIFA in vitro, allowing isolation of the complex by cochromatography. Using limited proteolysis of the purified proteins, we show here that changes in protease sensitivity of the Q linker regions of both NIFA and NIFL occurred when the complex was formed in the presence of MgADP. The N-terminal domain of NIFA adjacent to the Q linker was also protected by NIFL. Experiments with truncated versions of NIFA demonstrate that the central domain of NIFA is sufficient to cause protection of the Q linker of NIFL, although in this case, stable protein complexes are not detectable by cochromatography.
Quinone Profiles of
Thermoplasma acidophilum
HO-62
Authors: Shimada Haruo , Shida Yasuo , Nemoto Naoki , Oshima Tairo , Yamagishi Akihiko 
Published: July 2002

ABSTRACT

Quinones of
Thermoplasma acidophilum
HO-62 were analyzed by high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance. Menaquinone, methionaquinone, and 2-
trans
and 2-
cis
forms of thermoplasmaquinone were identified. The relative amount of thermoplasmaquinone increased under anaerobic conditions, and those of menaquinone and methionaquinone increased under aerobic conditions.
OmpC Is the Receptor for Gifsy-1 and Gifsy-2 Bacteriophages of
Salmonella
Authors: Ho Theresa D. , Slauch James M. 
Published: July 2002

ABSTRACT

Mutations in the
Salmonella enterica
serovar Typhimurium
ompC
gene conferred resistance to Gifsy-1 and Gifsy-2 bacteriophages. Selection for complementing plasmids yielded clones of
ompC
. Introduction of an
ompC
clone into
Escherichia coli
conferred the ability to adsorb Gifsy phage. These data show that OmpC is the receptor for Gifsy-1 and Gifsy-2 phages.
In Vitro Transposition System for Efficient Generation of Random Mutants of
Campylobacter jejuni
Authors: Colegio Oscar R. , Griffin Thomas J. , Grindley Nigel D. F. , Galán Jorge E. 
Published: July 2002

ABSTRACT

Campylobacter jejuni
is the most common cause of food-borne illnesses in the United States. Despite the fact that the entire nucleotide sequence of its genome has recently become available, its mechanisms of pathogenicity are poorly understood. This is in part due to the lack of an efficient mutagenesis system. Here we describe an in vitro transposon mutagenesis system based on the
Staphylococcus aureus
transposable element Tn
552
that allows the efficient generation of insertion mutants of
C. jejuni
. Insertions occur randomly and throughout the entire bacterial genome. We have tested this system in the isolation of nonmotile mutants of
C. jejuni
. Demonstrating the utility of the system, six nonmotile mutants from a total of nine exhibited insertions in genes known to be associated with motility. An additional mutant had an inactivating insertion in sigma 54, implicating this transcription factor in flagellum regulation. The availability of this efficient system will greatly facilitate the study of the mechanisms of pathogenesis of this important pathogen.
Growth Phase Variation in Cell and Nucleoid Morphology in a
Bacillus subtilis recA
Mutant
Authors: Sciochetti Stephen A. , Blakely Garry W. , Piggot Patrick J. 
Published: July 2002

ABSTRACT

The major role of RecA is thought to be in helping repair and restart stalled replication forks. During exponential growth,
Bacillus subtilis recA
cells exhibited few microscopically observable nucleoid defects. However, the efficiency of plating was about 12% of that of the parent strain. A substantial and additive defect in viability was also seen for
addB
and
recF
mutants, suggesting a role for the corresponding recombination paths during normal growth. Upon entry into stationary phase, a subpopulation (∼15%) of abnormally long cells and nucleoids developed in
B. subtilis recA
mutants. In addition,
recA
mutants showed a delay in, and a diminished capacity for, effecting prespore nucleoid condensation.
Examination of the
Borrelia burgdorferi
Transcriptome in
Ixodes scapularis
during Feeding
Authors: Narasimhan Sukanya , Santiago Felix , Koski Raymond A. , Brei Brandon , Anderson John F. , Fish Durland , Fikrig Erol 
Published: July 2002

ABSTRACT

Borrelia burgdorferi
gene expression within the guts of engorging
Ixodes scapularis
ticks was examined by use of differential immunoscreening and differential expression with a customized amplified library. Fourteen chromosomal genes involved in energy metabolism, substrate transport, and signal transduction and 10 (4 chromosomal and 6 plasmid) genes encoding putative lipoproteins and periplasmic proteins were preferentially expressed in engorging ticks. These data demonstrate a new approach to the global analysis of
B. burgdorferi
genes that are preferentially expressed within the vector during feeding.
Analysis of the Heat Shock Response of
Neisseria meningitidis
with cDNA- and Oligonucleotide-Based DNA Microarrays
Authors: Guckenberger Matthias , Kurz Sebastian , Aepinus Christian , Theiss Stephanie , Haller Sabine , Leimbach Thomas , Panzner Ursula , Weber Jacqueline , Paul Hubert , Unkmeir Alexandra , Frosch Matthias , Dietrich Guido 
Published: July 2002

ABSTRACT

Oligonucleotide- and cDNA-based microarrays comprising a subset of
Neisseria meningitidis
genes were assessed for study of the meningococcal heat shock response and found to be highly suitable for transcriptional profiling of
N. meningitidis
. Employing oligonucleotide arrays encompassing the entire genome of
N. meningitidis
, we analyzed the meningococcal heat shock response on a global scale and identified 55 heat shock-deregulated open reading frames (34 induced and 21 repressed).
Characterization of
AFMP1
: a Novel Target for Serodiagnosis of Aspergillosis
Authors: Yuen Kwok-Yung , Chan Che-Man , Chan King-Man , Woo Patrick C. Y. , Che Xiao-Yan , Leung Andy S. P. , Cao Liang 
Published: July 2002

ABSTRACT

We cloned the
AFMP1
gene, which encodes the first antigenic cell wall galactomannoprotein in
Aspergillus fumigatus. AFMP1
codes for a protein, Afmp1p, of 284 amino acid residues, with a few sequence features that are present in Mp1p, the antigenic cell wall mannoprotein in
Penicillium marneffei
that we described previously, as well as several other cell wall proteins of
Saccharomyces cerevisiae
and
Candida albicans
. It contains a serine- and threonine-rich region for O glycosylation, a signal peptide, and a putative glycosylphosphatidyl inositol attachment signal sequence. Specific anti-Afmp1p antibody was generated with recombinant Afmp1p protein purified from
Escherichia coli
to allow further characterization of Afmp1p. Afmp1p has a high affinity for
Galanthus nivalis
agglutinin, a characteristic indicative of a mannoprotein. Furthermore, it was recognized by a rat monoclonal antibody against the galactofuran side chain of galactomannan, indicating that it is a galactomannoprotein. Ultrastructural analysis by immunogold staining indicated that Afmp1p is present in the cell walls of the hyphae and conidia of
A. fumigatus
. Finally, it was observed that patients with aspergilloma and invasive aspergillosis due to
A. fumigatus
develop a specific antibody response against Afmp1p. This suggested that the recombinant protein and its antibody may be useful for serodiagnosis in patients with aspergilloma or invasive aspergillosis, and the protein may represent a good cell surface target for host humoral immunity.
Characterization of Enteropathogenic and Enteroaggregative
Escherichia coli
Isolated from Diarrheal Outbreaks
Authors: Yatsuyanagi Jun , Saito Shioko , Sato Hiroyasu , Miyajima Yoshimichi , Amano Ken-Ichi , Enomoto Katsuhiko 
Published: July 2002

ABSTRACT

Virulence characteristics of diarrheal outbreak-associated
Escherichia coli
O55:NM, O126:NM, and O111:NM were examined. The
E. coli
O55:NM strains were atypical enteropathogenic
E. coli
(EPEC), while the
E. coli
O126:NM and O111:NM strains should be classified as enteroaggregative
E. coli
(EAggEC). The contributions of EPEC and EAggEC to the human disease burden in Japan might be significantly greater than is currently appreciated.
Comparison of Three Commercially Available Peptide-Based Immunoglobulin G (IgG) and IgA Assays to Microimmunofluorescence Assay for Detection of
Chlamydia trachomatis
Antibodies
Authors: Morré Servaas A. , Munk Christian , Persson Kenneth , Krüger-Kjaer Susanne , van Dijk Rogier , Meijer Chris J. L. M. , van den Brule Adriaan J. C. 
Published: July 2002

ABSTRACT

Three commercially available, peptide-based enzyme-linked immunosorbent assay (ELISA) systems (Chlamydia trachomatis IgG and IgA EIA [CT-EIA; Labsystems OY, Helsinki, Finland], SeroCT IgG and IgA [SeroCT; Savyon Diagnostics Ltd., Ashdod, Israel], and Chlamydia trachomatis IgG and IgA pELISA [CT pELISA; Medac, Wedel, Germany]) were evaluated for the detection of serum immunoglobulin G (IgG) and IgA antibodies specific for
Chlamydia trachomatis
and compared to the “gold standard” assay, the microimmunofluorescence (MIF) assay. Serological responses were analyzed in 149 women aged 20 to 30 years. Cervical swabs obtained from these women were examined for
C. trachomatis
by PCR, and 43 were found to be positive. The overall seroprevalence rates detected by CT-EIA, SeroCT, CT pELISA, and the MIF assay were 42, 42, 35, and 39%, respectively, for IgG and 7, 7, 3, and 7%, respectively, for IgA. The IgG seroprevalence rates for the PCR-positive women were two to three times higher than those for the PCR-negative women, i.e., 72 versus 29%, 72 versus 29%, 47 versus 26%, and 74 versus 25% for CT-EIA, SeroCT, CT pELISA, and the MIF assay, respectively. After discrepancy analysis, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the IgG assays; for CT-EIA they were 84.7, 98.6, 98.4, and 86.7%, respectively; for CT pELISA they were 71.4, 97.3, 96.2, and 78.3%, respectively; for SeroCT they were 84.7, 98.6, 98.4, and 86.3%, respectively; and for the MIF assay they were 79.2, 83.1, 98.3, and 83.1%, respectively. In conclusion, these peptide-based ELISA systems for the serological detection of
C. trachomatis
infection performed as well as the MIF assay. Since these tests are less time-consuming, less expensive, and easier to perform than the MIF assay, they might be useful in the serodiagnosis of chlamydial infection.
Rapid and Sensitive Detection of Physical Status of Human Papillomavirus Type 16 DNA by Quantitative Real-Time PCR
Authors: Nagao Shoji , Yoshinouchi Mitsuo , Miyagi Yasunari , Hongo Atsushi , Kodama Junichi , Itoh Sachio , Kudo Takafumi 
Published: July 2002

ABSTRACT
A rapid quantitative real-time PCR method was employed to quantify the copy number of E2 and E6 genes for analysis of the physical status of human papillomavirus type 16 (HPV-16) DNA. Significant differences with respect to both copy numbers were found when more than 40% of HPV-16 DNA was integrated with disruption of the E2 gene in an experimental model. The physical status of HPV-16 DNA in 50 clinical samples was exclusively episomal in 21 cases (42%), concomitant in 14 cases (28%), and integrated in 15 cases (30%). The prevalence of integrated and/or concomitant forms of HPV-16 DNA increased with progression of cervical disease. Four of 11 cervical intraepithelial neoplasia involved integrated forms of HPV-16 DNA partially or exclusively. This rapid, sensitive technique is useful in the analysis of the physical status of HPV DNA.
New Real-Time PCR Able To Detect in a Single Tube Multiple Rifampin Resistance Mutations and High-Level Isoniazid Resistance Mutations in
Mycobacterium tuberculosis
Authors: García de Viedma Darío , del Sol Díaz Infantes Maria , Lasala Fátima , Chaves Fernando , Alcalá Luis , Bouza Emilio 
Published: July 2002

ABSTRACT

The emergence of resistance to antituberculosis drugs is a relevant matter worldwide, but the retrieval of antibiograms for
Mycobacterium tuberculosis
is severely delayed when phenotypic methods are used. Genotypic methods allow earlier detection of resistance, although conventional approaches are cumbersome or lack sensitivity or specificity. We aimed to design a new real-time PCR method to detect rifampin (RIF)- and isoniazid (INH)-resistant
M. tuberculosis
strains in a single reaction tube. First, we characterized the resistant isolates in our area of Spain by DNA sequencing. Some mutation was found within the
rpoB
core region in all the RIF-resistant (RIF
r
) strains. Forty-six percent of the INH-resistant (INH
r
) strains showed a mutation in
katG
codon 315, and most of these were associated with high MICs. Eighteen of the RIF
r
, INH
r
, and multidrug-resistant strains sequenced were tested by our real-time PCR assay; and full concordance of the results of the PCR with the sequencing data was obtained. In addition, a blind test was performed with a panel of 15 different susceptible and resistant strains from throughout Spain, and our results were also in 100% agreement with the sequencing data. Ours is the first assay based on rapid-cycle PCR able to simultaneously detect in a single reaction tube a large variety of mutations associated with RIF resistance (12 different mutations affecting 8 independent codons, including the most prevalent mutations at positions 526 and 531) and the most frequent INH resistance mutations. Our design could be a model for new, rapid genotypic methods able to simultaneously detect a wide variety of antibiotic resistance mutations.
Recombinant Nucleoprotein-Based Enzyme-Linked Immunosorbent Assay for Detection of Immunoglobulin G Antibodies to Crimean-Congo Hemorrhagic Fever Virus
Authors: Saijo Masayuki , Qing Tang , Niikura Masahiro , Maeda Akihiko , Ikegami Tetsuro , Prehaud Christophe , Kurane Ichiro , Morikawa Shigeru 
Published: July 2002

ABSTRACT

The full-length nucleoprotein of Crimean-Congo hemorrhagic fever virus (CCHFV; 482 amino acid residues) was expressed as a His-tagged recombinant protein (His-CCHFV rNP) in the baculovirus system. The His-CCHFV rNP was efficiently expressed in insect cells and purified by Ni
2+
column chromatography. Using this substrate, an immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) was developed. We evaluated the sensitivity and specificity of the IgG ELISA, using serum samples previously determined to be antibody positive or negative by immunofluorescence tests on CCHFV-infected Vero E6 cells. We found very good correlation between the two tests: 87% for the positive sera (13 of 15) and 99% for the negative sera (107 of 108). These results indicate that the new IgG ELISA using His-CCHFV rNP has high sensitivity and specificity for detecting CCHFV antibodies. The CCHF patients' sera with high titers reacted only with the NP fragment containing amino acid residues between 201 and 306 in Western blotting. It is known that amino acid homologies are high in this region among various isolates. Thus, it is expected that this ELISA can detect antibodies not only for Chinese strains of CCHFV but also for other strains circulating in the world. These results suggest that the IgG ELISA system developed with the recombinant CCHFV NP is a valuable tool for diagnosis and epidemiological investigations of CCHFV infections.
Discrimination between Cases of Duodenal Ulcer and Gastritis on the Basis of Putative Virulence Factors of
Helicobacter pylori
Authors: Yamaoka Yoshio , Souchek Julianne , Odenbreit Stefan , Haas Rainer , Arnqvist Anna , Borén Thomas , Kodama Tadashi , Osato Michael S. , Gutierrez Oscar , Kim Jong G. , Graham David Y. 
Published: July 2002

ABSTRACT

The BabA,
cagA
, and
vacA
statuses of 827
Helicobacter pylori
isolates were used in logistic regression models to discriminate duodenal ulcer from gastritis. Only BabA was a candidate for a universal virulence factor, but the low
c
statistic value (0.581) indicates that none of these factors were helpful in predicting the clinical presentation.
Disseminated Herpes Simplex Virus and Varicella Zoster Virus Coinfection in a Patient Taking Thalidomide for Relapsed Multiple Myeloma
Authors: Curley Matthew J. , Hussein Shakir A. , Hassoun Paul M. 
Published: July 2002

ABSTRACTDisseminated herpes simplex virus (HSV) and varicella zoster virus (VZV) have been reported individually in immunosuppressed adults. We present a case of coinfection with disseminated HSV and VZV infection in a patient taking thalidomide for relapsed multiple myeloma. This is the first report of opportunistic infection associated with thalidomide.
Exacerbation of Autoantibody-Mediated Hemolytic Anemia by Viral Infection
Authors: Meite Mory , Léonard Sabine , Idrissi Mohammed El Azami El , Izui Shozo , Masson Pierre L. , Coutelier Jean-Paul 
Published: July 2002

ABSTRACTStrong enhancement of the pathogenicity of an antierythrocyte monoclonal antibody was observed after infection of mice with lactate dehydrogenase-elevating virus. While injection of the antierythrocyte antibody alone induced only moderate anemia, concomitant infection with this virus, which is harmless in most normal mice, led to a dramatic drop in the hematocrit and to death of infected animals. In vitro and in vivo analyses showed a dramatic increase in the ability of macrophages from infected mice to phagocytose antibody-coated erythrocytes. These results indicate that viruses can trigger the onset of autoimmune disease by enhancing the pathogenicity of autoantibodies. They may explain how unrelated viruses could be implicated in the etiology of autoantibody-mediated autoimmune diseases.
Quantitation of CD8+T-Lymphocyte Responses to Multiple Epitopes from Simian Virus 40 (SV40) Large T Antigen in C57BL/6 Mice Immunized with SV40, SV40 T-Antigen-Transformed Cells, or Vaccinia Virus Recombinants Expressing Full-Length T Antigen or Epitope Minigenes
Authors: Mylin Lawrence M. , Schell Todd D. , Roberts Debra , Epler Melanie , Boesteanu Alina , Collins Edward J. , Frelinger Jeffrey A. , Joyce Sebastian , Tevethia Satvir S. 
Published: July 2002

ABSTRACTThe cytotoxic T-lymphocyte response to wild-type simian virus 40 large tumor antigen (Tag) in C57BL/6 (H2b) mice is directed against threeH2-Db-restricted epitopes, I, II/III, and V, and oneH2-Kb-restricted epitope, IV. Epitopes I, II/III, and IV are immunodominant, while epitope V is immunorecessive. We investigated whether this hierarchical response was established in vivo or was due to differential expansion in vitro by using direct enumeration of CD8+T lymphocytes with Tag epitope/major histocompatibility complex class I tetramers and intracellular gamma interferon staining. The results demonstrate that epitope IV-specific CD8+T cells dominated the Tag-specific response in vivo following immunization with full-length Tag while CD8+T cells specific for epitopes I and II/III were detected at less than one-third of this level. The immunorecessive nature of epitope V was apparent in vivo, since epitope V-specific CD8+T cells were undetectable following immunization with full-length Tag. In contrast, high levels of epitope V-specific CD8+T lymphocytes were recruited in vivo following immunization and boosting with a Tag variant in which epitopes I, II/III, and IV had been inactivated. In addition, analysis of the T-cell receptor β (TCRβ) repertoire of Tag epitope-specific CD8+cells revealed that multiple TCRβ variable regions were utilized for each epitope except Tag epitope II/III, which was limited to TCRβ10 usage. These results indicate that the hierarchy of Tag epitope-specific CD8+T-cell responses is established in vivo.
Mature Dendritic Cells Infected with Herpes Simplex Virus Type 1 Exhibit Inhibited T-Cell Stimulatory Capacity
Authors: Kruse Monika , Rosorius Olaf , Krätzer Friedrich , Stelz Gerhard , Kuhnt Christine , Schuler Gerold , Hauber Joachim , Steinkasserer Alexander 
Published: July 2002

ABSTRACTMature dendritic cells (DC) are the most potent antigen-presenting cells within the entire immune system. Interference with the function of these cells therefore constitutes a very powerful mechanism for viruses to escape immune responses. Several members of theHerpesviridaefamily have provided examples of such escape strategies, including interference with antigen presentation and production of homologous cytokines. In this study we investigated the infection of mature DC with herpes simplex virus type 1 (HSV-1) and the way in which infection alters the phenotype and function of mature DC. Interestingly, the T-cell-stimulatory capacity of these DC was strongly impaired. Furthermore, we demonstrated that HSV-1 leads to the specific degradation of CD83, a cell surface molecule which is specifically upregulated during DC maturation. These data indicate that HSV-1 has developed yet another novel mechanism to escape immune responses.
Efficient Homologous RNA Recombination and Requirement for an Open Reading Frame during Replication of Equine Arteritis Virus Defective Interfering RNAs
Authors: Molenkamp Richard , Greve Sophie , Spaan Willy J. M. , Snijder Eric J. 
Published: July 2002

ABSTRACT

Equine arteritis virus
(EAV), the prototype arterivirus, is an enveloped plus-strand RNA virus with a genome of approximately 13 kb. Based on similarities in genome organization and protein expression, the arteriviruses have recently been grouped together with the coronaviruses and toroviruses in the newly established order
Nidovirales
. Previously, we reported the construction of pEDI, a full-length cDNA copy of EAV DI-b, a natural defective interfering (DI) RNA of 5.6 kb (R. Molenkamp et al., J. Virol. 74:3156–3165, 2000). EDI RNA consists of three noncontiguous parts of the EAV genome fused in frame with respect to the replicase gene. As a result, EDI RNA contains a truncated replicase open reading frame (EDI-ORF) and encodes a truncated replicase polyprotein. Since some coronavirus DI RNAs require the presence of an ORF for their efficient propagation, we have analyzed the importance of the EDI-ORF in EDI RNA replication. The EDI-ORF was disrupted at different positions by the introduction of frameshift mutations. These were found either to block DI RNA replication completely or to be removed within one virus passage, probably due to homologous recombination with the helper virus genome. Using recombination assays based on EDI RNA and full-length EAV genomes containing specific mutations, the rates of homologous RNA recombination in the 3′- and 5′-proximal regions of the EAV genome were studied. Remarkably, the recombination frequency in the 5′-proximal region was found to be approximately 100-fold lower than that in the 3′-proximal part of the genome.