bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role for Periodontitis in the Progression of Lipid Deposition in an Animal Model
Authors: Jain Ashish , Batista Eraldo L. , Serhan Charles , Stahl Gregory L. , Van Dyke Thomas E. 
Published: September 2003

ABSTRACT

Epidemiologic studies have implicated periodontitis as a risk factor for the development of cardiovascular disease. However, no prospective studies investigating this potential relationship have been carried out. Age- and sex-matched New Zealand White rabbits were maintained on a diet consisting of 0.5% fat for 13 weeks to induce the accumulation of lipid deposits in the aorta as a model for atherogenesis. One-half of the animals received silk ligatures around their mandibular premolars followed by an application of a periodontal pathogen,
Porphyromonas gingivalis
, to induce periodontitis. Animals were sacrificed after 14 weeks. Periodontal disease severity was quantified radiographically, histologically, and by direct visualization of bone loss on defleshed skulls. Lipid deposition was evaluated by computer-assisted morphometry in the aortas en face after lipid deposits were stained with Sudan IV. Animals with experimentally induced periodontitis had more extensive accumulations of lipids in the aorta than did nonperiodontitis animals (
P
< 0.05), and there was a positive correlation between the severity of periodontal disease and the extent of lipid deposition (
r
2
= 0.9501). The results provide direct evidence that periodontitis may be a risk factor and may contribute to the pathogenesis of atherosclerosis. The data support the concept that infections at remote locations can modulate atherosclerotic events distantly.
Streptococcus pyogenesInfection Induces Septic Arthritis with Increased Production of the Receptor Activator of the NF-κB Ligand
Authors: Sakurai Atsuo , Okahashi Nobuo , Nakagawa Ichiro , Kawabata Shigetada , Amano Atsuo , Ooshima Takashi , Hamada Shigeyuki 
Published: September 2003

ABSTRACTBacterial arthritis is a rapidly progressive and highly destructive joint disease in humans, withStaphylococcus aureusandNeisseria gonorrhoeaethe major causative agents, although beta-hemolytic streptococci as well often induce the disease. We demonstrate here that intravenous inoculation of CD-1 mice with the group A streptococcus (GAS) speciesStreptococcus pyogenesresulted in a high incidence of septic arthritis. Signs of arthritis emerged within the first few days after injection, and bacterial examinations revealed that colonization of the inoculated GAS in the arthritic joints persisted for 21 days. Induction of persistent septic arthritis was dependent on the number of microorganisms inoculated. Immunohistochemical staining of GAS with anti-GAS antibodies revealed colonization in the joints of infected mice. Cytokine levels were quantified in the joints and sera of infected mice by using an enzyme-linked immunosorbent assay. High levels of interleukin-1β (IL-1β) and IL-6 were detected in the joints from 3 to 20 days after infection. We noted that an increase in the amount of receptor activator of NF-κB ligand (RANKL), which is a key cytokine in osteoclastogenesis, was also evident in the joints of the infected mice. RANKL was not detected in sera, indicating local production of RANKL in the infected joints. Blocking of RANKL by osteoprotegerin, a decoy receptor of RANKL, prevented bone destruction in the infected joints. These results suggest that GAS can colonize in the joints and induce bacterial arthritis. Local RANKL production in the infected joints may be involved in bone destruction.
Expression of
Cpgp40/15
in
Toxoplasma gondii
: a Surrogate System for the Study of
Cryptosporidium
Glycoprotein Antigens
Authors: O'Connor R. M. , Kim K. , Khan F. , Ward H. D. 
Published: September 2003

ABSTRACT

Cryptosporidium parvum
is a waterborne enteric coccidian that causes diarrheal disease in a wide range of hosts. Development of successful therapies is hampered by the inability to culture the parasite and the lack of a transfection system for genetic manipulation. The glycoprotein products of the
Cpgp40/15
gene, gp40 and gp15, are involved in
C. parvum
sporozoite attachment to and invasion of host cells and, as such, may be good targets for anticryptosporidial therapies. However, the function of these antigens appears to be dependent on the presence of multiple O-linked α-
N
-acetylgalactosamine (α-GalNAc) determinants. A eukaryotic expression system that would produce proteins bearing glycosylation patterns similar to those found on the native
C. parvum
glycoproteins would greatly facilitate the molecular and functional characterization of these antigens. As a unique approach to this problem, the
Cpgp40/15
gene was transiently expressed in
Toxoplasma gondii
, and the expressed recombinant glycoproteins were characterized. Antisera to gp40 and gp15 reacted with the surface membranes of tachyzoites expressing the
Cpgp40/15
construct, and this reactivity colocalized with that of antiserum to the
T. gondii
surface protein SAG1. Surface membrane localization was dependent on the presence of the glycophosphatidylinositol anchor attachment site present in the gp15 coding sequence. The presence of terminal O-linked α-GalNAc determinants on the
T. gondii
recombinant gp40 was confirmed by reactivity with
Helix pomatia
lectin and the monoclonal antibody 4E9, which recognizes α-GalNAc residues, and digestion with α-
N
-acetylgalactosaminidase. In addition to appropriate localization and glycosylation,
T. gondii
apparently processes the gp40/15 precursor into the gp40 and gp15 component glycopolypeptides, albeit inefficiently. These results suggest that a surrogate system using
T. gondii
for the study of
Cryptosporidium
biology may be useful.
Effector ExoU from the Type III Secretion System Is an Important Modulator of Gene Expression in Lung Epithelial Cells in Response to
Pseudomonas aeruginosa
Infection
Authors: McMorran B. , Town L. , Costelloe E. , Palmer J. , Engel J. , Hume D. , Wainwright B. 
Published: September 2003

ABSTRACT

Pseudomonas aeruginosa
is an important pathogen in immunocompromised patients and secretes a diverse set of virulence factors that aid colonization and influence host cell defenses. An important early step in the establishment of infection is the production of type III-secreted effectors translocated into host cells by the bacteria. We used cDNA microarrays to compare the transcriptomic response of lung epithelial cells to
P. aeruginosa
mutants defective in type IV pili, the type III secretion apparatus, or in the production of specific type III-secreted effectors. Of the 18,000 cDNA clones analyzed, 55 were induced or repressed after 4 h of infection and could be classified into four different expression patterns. These include (i) host genes that are induced or repressed in a type III secretion-independent manner (32 clones), (ii) host genes induced specifically by ExoU (20 clones), and (iii) host genes induced in an ExoU-independent but type III secretion dependent manner (3 clones). In particular, ExoU was essential for the expression of immediate-early response genes, including the transcription factor c-Fos. ExoU-dependent gene expression was mediated in part by early and transient activation of the AP1 transcription factor complex. In conclusion, the present study provides a detailed insight into the response of epithelial cells to infection and indicates the significant role played by the type III virulence mechanism in the initial host response.
Interleukin-15 as an Immune Adjuvant To Increase the Efficacy of
Mycobacterium bovis
Bacillus Calmette-Guérin Vaccination
Authors: Umemura Masayuki , Nishimura Hitoshi , Saito Kimika , Yajima Toshiki , Matsuzaki Goro , Mizuno Satoru , Sugawara Isamu , Yoshikai Yasunobu 
Published: September 2003

ABSTRACT

Interleukin-15 (IL-15) transgenic mice which had been inoculated with
Mycobacterium bovis
bacillus Calmette-Guérin (BCG) 24 weeks previously showed resistance against airborne infection with
Mycobacterium tuberculosis
H37Rv accompanied by an increased CD8
+
-Tc1-cell response. IL-15 may be used as an immune adjuvant given with BCG vaccination to enhance its biologic efficacy.
The Type IVB Pili of
Salmonella enterica
Serovar Typhi Bind to the Cystic Fibrosis Transmembrane Conductance Regulator
Authors: Tsui Inez S. M. , Yip Cecilia M. C. , Hackett Jim , Morris Christina 
Published: September 2003

ABSTRACT

Salmonella enterica
serovar Typhi expresses type IVB pili. We show that the prePilS protein (the soluble precursor form of the structural pilin) interacts with a 15-mer peptide representing the first extracellular domain of the cystic fibrosis transmembrane conductance regulator (CFTR), a recognized human epithelial cell receptor for serovar Typhi (G. B. Pier et al., Nature 393:79-82, 1998). This indicates that after mediating bacterial self-association (C. Morris et al., Infect. Immun. 71:1141-1146, 2003), the pili then act to attach the bacterial clumps to CFTR in the membrane of gut epithelial cells. These sequential type IVB pilus-mediated events cannot be performed by (for example)
S. enterica
serovar Typhimurium, which may explain why only serovar Typhi causes epidemics of enteric fever in humans.
Inflammatory Cytokine Production Predominates in Early Lyme Disease in Patients with Erythema Migrans
Authors: Glickstein Lisa , Moore Brian , Bledsoe Tara , Damle Nitin , Sikand Vijay , Steere Allen C. 
Published: September 2003

ABSTRACT

In a study of cytokine production ex vivo by
Borrelia burgdorferi
-stimulated peripheral blood mononuclear cells from 27 patients with culture-positive erythema migrans, production of inflammatory cytokines predominated, particularly gamma interferon and, to a lesser degree, tumor necrosis factor alpha. In contrast, with the exception of interleukin-13, anti-inflammatory cytokine production was negligible. Thus,
B. burgdorferi
antigens in early Lyme disease often induce a strong inflammatory response.
Antibody Responses Elicited against theTreponema pallidumRepeat Proteins Differ during Infection with Different Isolates ofTreponema pallidumsubsp.pallidum
Authors: Leader Brandon T. , Hevner Karin , Molini Barbara J. , Barrett Lynn K. , Van Voorhis Wesley C. , Lukehart Sheila A. 
Published: September 2003

ABSTRACTVariation in the expression of the different Tpr proteins in the syphilis spirochete,Treponema pallidumsubsp.pallidum, may have important implications in its ability to evade host immune detection and cause persistent infection. In the present study we examined the pattern of antibody responsiveness to different Tpr members during infection with three isolates ofT. pallidum. There was variability in the specificities and temporal patterns of reactivity of the antibodies elicited against the individual Tpr proteins, suggesting that isolates may express different repertoires of Tpr proteins during infection.
Differential Contribution of Toll-Like Receptors 4 and 2 to the Cytokine Response toSalmonella entericaSerovar Typhimurium andStaphylococcus aureusin Mice
Authors: Lembo Annalisa , Kalis Christoph , Kirschning Carsten J. , Mitolo Vincenzo , Jirillo Emilio , Wagner Hermann , Galanos Chris , Freudenberg Marina A. 
Published: September 2003

ABSTRACTThe contribution of murine Toll-like receptors 2 and 4 (TLR2 and -4, respectively) to cytokine induction by heat-killed bacteria was analyzed in vitro and in vivo. Gram-negative bacteria induced cytokines primarily via TLR4; the contribution of TLR2 was only minor. Neither TLR4 nor, surprisingly, TLR2 was required in the MyD88-dependent response toStaphylococcus aureus.
Sequence and Expression Analysis of
virB9
of the Type IV Secretion System of
Ehrlichia canis
Strains in Ticks, Dogs, and Cultured Cells
Authors: Felek Suleyman , Huang Haibin , Rikihisa Yasuko 
Published: September 2003

ABSTRACT

Ehrlichia canis virB9
was cloned and expressed. The sequences of
virB9
from six geographic locations were identical.
virB9
was transcribed by
E. canis
in dogs, ticks, and cell culture. Infected dogs had antibodies to recombinant VirB9, indicating that VirB9 was produced by
E. canis
in dogs and was antigenic.
Host Adaptation of Pigeon Isolates of
Salmonella enterica
subsp.
enterica
Serovar Typhimurium Variant Copenhagen Phage Type 99 Is Associated with Enhanced Macrophage Cytotoxicity
Authors: Pasmans Frank , Van Immerseel Filip , Heyndrickx Marc , Martel An , Godard Claudine , Wildemauwe Christa , Ducatelle Richard , Haesebrouck Freddy 
Published: September 2003

ABSTRACT

Phage type 99 of
Salmonella enterica
subsp.
enterica
serovar Typhimurium variant Copenhagen strains isolated from pigeons were examined for the presence of genotypic and phenotypic characteristics. The pulsed-field gel electrophoresis patterns obtained with
Xba
I and
Bln
I from 38 pigeon strains were compared with those obtained from 89 porcine, poultry, and human strains of variant Copenhagen. Identical patterns with
Xba
I and four closely related patterns with
Bln
I were obtained with the pigeon strains, whereas 16
Xba
I patterns were found with the other strains. The
Xba
I patterns of the pigeon strains showed a low genetic similarity to the patterns of the porcine, poultry, and human strains and invariably showed a low-molecular-weight band that was absent in the majority of the other strains. The virulence genes
shdA
,
spvR
,
pefA
,
sopE
, and
spvB
were uniformly present in six pigeon isolates representing the genetic diversity found with
Bln
I. These six pigeon-derived strains were highly cytotoxic for pigeon macrophages compared to three porcine strains. After experimental infection of pigeons with a pigeon strain, clinical symptoms, fecal shedding, and colonization of internal organs were more pronounced than those after infection with a porcine strain. These data suggest that the phage type 99 strains used in this study are highly adapted to pigeons and should be classified as a host-restricted lineage of the serovar Typhimurium.
Serum Amyloid P Component Binding to Shiga Toxin 2 Requires Both A Subunit and B Pentamer
Authors: Marcato Paola , Vander Helm Kathleen , Mulvey George L. , Armstrong Glen D. 
Published: September 2003

ABSTRACT
Solid-phase binding, competitive binding, and cytotoxicity neutralization assays indicate that the B pentamer and A subunit both contribute to human serum amyloid P (HuSAP) component binding to Stx2. A polyvalent globotriaosyl-ceramide receptor analog, Daisy, did not competitively inhibit HuSAP binding, implying that the two ligands bind to different Stx2 domains.
Streptococcus pyogenes
Infection in Mouse Skin Leads to a Time-Dependent Up-Regulation of Protein H Expression
Authors: Smith Tara C. , Sledjeski Darren D. , Boyle Michael D. P. 
Published: September 2003

ABSTRACT

Streptococcus pyogenes
protein H (
sph
) is an immunoglobulin-binding protein present in the Mga regulon of certain M1 serotype isolates. Although
sph
is present in many strains, it is frequently not expressed. In this paper we show that protein H was highly expressed after bacteria were injected into the skin of mice and were recovered from the blood, kidney, or spleen at various times postinfection. The percentage of protein H-positive colonies increased with time, reaching 100% in the spleen and kidney within 24 to 72 h postinfection. The up-regulation of
sph
expression was also observed in a
mga
mutant.
Analysis of Expression Profile of Mammalian Cell Entry (
mce
) Operons of
Mycobacterium tuberculosis
Authors: Kumar Ashwani , Bose Mridula , Brahmachari Vani 
Published: September 2003

ABSTRACT

The sequencing of the complete genome of
M. tuberculosis
H37Rv has resulted in the recognition of four
mce
operons in its genome by in silico analysis. In an attempt to understand the significance of the redundancy of
mce
operons, we analyzed the expression profile of
mce
operons after different periods of growth in culture as well as during in vivo infection. Our results strongly suggest that
mce1
is expressed as a polycistronic message. In culture from day 8 to day 12, expression of only
mce1
was observed, but as the cultures progress towards stationary phase the expression profile of
mce
operons was altered; the transcripts of the
mce1
operon were barely detected while those of the
mce4
operon were prominent. In an analysis of the expression of
mce
operons in tubercle material collected from infected animal tissues, we detected the expression of
mce1
, -
3
and -
4
. Our results imply that
mce
operons other than
mce1
are also expressed during infection and that it is necessary to examine their role in pathogenesis.
Identification and Characterization of a New Staphylococcal Enterotoxin-Related Putative Toxin Encoded by Two Kinds of Plasmids
Authors: Omoe Katsuhiko , Hu Dong-Liang , Takahashi-Omoe Hiromi , Nakane Akio , Shinagawa Kunihiro 
Published: September 2003

ABSTRACT

We identified and characterized a novel staphylococcal enterotoxin-like putative toxin, which is named SER. Nucleotide sequencing analysis of the
ser
gene revealed that
ser
was most closely related to the
seg
gene. The
ser
gene product, SER, was successfully expressed as a recombinant protein in an
Escherichia coli
expression system, and recombinant SER (rSER) showed significant T-cell stimulation activity. The SER production in
ser
-harboring
Staphylococcus aureus
strains was confirmed by Western blot analysis using anti-rSER antibody. Moreover,
ser
was seen to be encoded by at least two types of plasmids. In particular, one kind of plasmid encoding the
ser
gene has been known as a
sed
- and
sej
-carrying pIB485-related plasmid.
Streptococcus pneumoniae
Damages the Ciliated Ependyma of the Brain during Meningitis
Authors: Hirst Robert A. , Gosai Bejal , Rutman Andrew , Andrew Peter W. , O'Callaghan Christopher 
Published: September 2003

ABSTRACT

Streptococcus pneumoniae
meningitis remains a disease with a poor outcome for the patient. A region of the brain that has been neglected in the study of meningitis is the ependyma, which has been identified as a location of adult pluripotent cells. In this study we have used a rat model of meningitis to examine whether the ependymal layer is affected by
S. pneumoniae
. The effects included localized loss of cilia, a decrease of the overall ependymal ciliary beat frequency, and damage to the ependymal ultrastructure during meningitis. In conclusion, loss of ependymal cells and ciliary function exposes the underlying neuronal milieu to host and bacterial cytotoxins and this is likely to contribute to the neuropathology commonly observed in pneumococcal meningitis.
Evaluation of the Roles of Four
Candida albicans
Genes in Virulence by Using Gene Disruption Strains That Express
URA3
from the Native Locus
Authors: Cheng Shaoji , Nguyen M. Hong , Zhang Zongde , Jia Hongyan , Handfield Martin , Clancy Cornelius J. 
Published: September 2003

ABSTRACT

Reintroducing
URA3
to its native locus in
Candida albicans not5
,
not3
,
bur2
, and
kel1
disruption mutants enabled us to directly compare strains with control strain CAI-12. We showed that
URA3
position affected orotidine 5′-monophosphate decarboxylase activity, hyphal morphogenesis, adherence, and mortality in murine disseminated candidiasis. After
URA3
was reintroduced to its native locus, only
NOT5
could be conclusively ascribed a role in virulence.
Identification of an Inducible Bacteriophage in a Virulent Strain of
Streptococcus suis
Serotype 2
Authors: Harel J. , Martinez G. , Nassar A. , Dezfulian H. , Labrie S. J. , Brousseau R. , Moineau S. , Gottschalk M. 
Published: September 2003

ABSTRACT

Streptococcus suis
infection is considered to be a major problem in the swine industry worldwide. Most virulent Canadian isolates of
S. suis
serotype 2 do not produce the known virulence markers for this pathogen. PCR-based subtraction hybridization was adapted to isolate unique DNA sequences which were specific to virulent strains of
S. suis
isolated in Canada. Analysis of some subtracted DNA clones revealed significant homology with bacteriophages of gram-positive bacteria. An inducible phage (named Ss1) was observed in
S. suis
following the incubation of the virulent strain 89-999 with mitomycin C. Phage Ss1 has a long noncontractile tail and a small isometric nucleocapsid and is a member of the
Siphoviridae
family. Ss1 phage DNA appears to be present in most Canadian
S. suis
strains tested in this study, which were isolated from diseased pigs or had proven virulence in mouse or pig models. To our knowledge, this is the first report of the isolation of a phage in
S. suis
.
Importance Measures of Multi-State Components in Multi-State Systems
Authors: Zio Enrico , Podofillini Luca 
Published: September 2003

In system engineering a practical and difficult problem is the identification of those components that mostly influence the system behaviour with respect to safety and reliability. In this regard, the information provided by importance measures gives useful insights for the safe and efficient operation of the system. Importance measures have received attention since the early times of risk and reliability analysis and have been defined in several ways for binary components in binary systems. Yet, there are applications for which a multi-state modelling of components and systems is required. This is the case of manufacturing production lines and power generation systems in which the components and the overall systems can operate at different, discrete, levels of performance so that the output provided is a fraction of the nominal design capacity. A similar situation occurs in transportation systems. In the limit, there is the case of systems whose performances are characterized in terms of an infinite set of continuous states. These are, for example, the passive safety systems whose utilization is becoming more and more significant in the advanced and innovative concepts of nuclear reactor design. In this paper, the definitions of the most frequently used classical importance measures are generalized to multi-state systems constituted by multi-state components. The extensions introduced characterize the importance of a component achieving a given level of performance with respect to the overall multi-state system unavailability and performance. The informative content provided by the introduced measures is illustrated on a simple multi-state system.
Dissecting Contributions of Prefrontal Cortex and Fusiform Face Area to Face Working Memory
Authors: Druzgal T. Jason , D'Esposito Mark 
Published: September 2003

Abstract
Interactions between prefrontal cortex (PFC) and stimulusspecific visual cortical association areas are hypothesized to mediate visual working memory in behaving monkeys. To clarify the roles for homologous regions in humans, event-related fMRI was used to assess neural activity in PFC and fusiform face area (FFA) of subjects performing a delay-recognition task for faces. In both PFC and FFA, activity increased parametrically with memory load during encoding and maintenance of face stimuli, despite quantitative differences in the magnitude of activation. Moreover, timing differences in PFC and FFA activation during memory encoding and retrieval implied a context dependence in the flow of neural information. These results support existing neurophysiological models of visual working memory developed in the nonhuman primate.