bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-Quality, Cost-Effective Strategy for Detection of Autoantibodies to Extractable Nuclear Antigens
Authors: Phan Tri G. , Ng Watson W. S. , Bird Dana , Smithers Kara , Wong Vicky , Gallagher Kerri , Williams Andrew , Adelstein Stephen 
Published: July 2002

ABSTRACT
We evaluated methods for the detection of autoantibodies to extractable nuclear antigens (ENAs) to determine the strategy that yielded the most cost effective and clinically meaningful result. We prospectively compared counterimmunoelectrophoresis (CIEP) with and without serum prediffusion (SPD) and found that SPD significantly improved the quality of precipitation lines. This resulted in a decreased requirement for repeat testing and, consequently, was associated with a significant decrease in reagent costs and specimen turnaround time. We also retrospectively compared reactivity by CIEP, CIEP plus SPD, enzyme-linked immunosorbent assay (ELISA), and line immunoassay (LIA) of 52 serum samples that were previously determined to be positive for ENAs, and we correlated the results with clinical diagnoses. There was significant agreement among CIEP, CIEP plus SPD, ELISA, and LIA for the detection of anti-SS-A, anti-SS-B and anti-RNP. In general, CIEP, CIEP plus SPD, and LIA correlated better with the clinical diagnoses than ELISA, even though ELISA detected anti-ENAs more often than the other methods. CIEP plus SPD is therefore the most cost effective method for the identification of clinically meaningful ENAs. Based on our experience, we now screen for ENAs by CIEP, and positive samples are then typed by CIEP plus SPD. Samples that are difficult to interpret are then further assessed by an alternative method.
Viral Load in Breast Milk Correlates with Transmission of Human Cytomegalovirus to Preterm Neonates, but Lactoferrin Concentrations Do Not
Authors: van der Strate B. W. A. , Harmsen M. C. , Schäfer P. , Swart P. J. , The T. H. , Jahn G. , Speer C. P. , Meijer D. K. F. , Hamprecht K. 
Published: July 2002

ABSTRACT
In vitro, lactoferrin (LF) strongly inhibits human cytomegalovirus (HCMV), which led us to hypothesize that in vivo HCMV might also be inhibited in secretions with high LF concentrations. In breast milk, high viral loads observed as high viral DNA titers tended to coincide with higher LF levels. However, the LF levels did not correlate to virus transmission to preterm infants. The viral load in the transmitting group was highest compared to the nontransmitting group. We conclude that viral load in breast milk is an important factor for transmission of the virus.
Antibody Responses toAcinetobacterspp. andPseudomonas aeruginosain Multiple Sclerosis: Prospects for Diagnosis Using the Myelin-Acinetobacter-Neurofilament Antibody Index
Authors: Hughes L. E. , Bonell S. , Natt R. S. , Wilson C. , Tiwana H. , Ebringer A. , Cunningham P. , Chamoun V. , Thompson E. J. , Croker J. , Vowles J. 
Published: July 2002

ABSTRACTAntibody responses toAcinetobacter(five strains),Pseudomonas aeruginosa,Escherichia coli, myelin basic protein (MBP), and neurofilaments were measured in sera from 26 multiple sclerosis (MS) patients, 20 patients with cerebrovascular accidents (CVA), 10 patients with viral encephalitis, and 25 healthy blood donors. In MS patients, elevated levels of antibodies against all strains ofAcinetobactertested were present, as well as antibodies againstP. aeruginosa, MBP, and neurofilaments, but not antibodies toE. coli, compared to the CVA group and controls. The myelin-Acinetobacter-neurofilament antibody index appears to distinguish MS patients from patients with CVAs or healthy controls. The relevance of such antibodies to the neuropathology of MS requires further evaluation.
Human Lactoferrin Interacts with Soluble CD14 and Inhibits Expression of Endothelial Adhesion Molecules, E-Selectin and ICAM-1, Induced by the CD14-Lipopolysaccharide Complex
Authors: Baveye S. , Elass E. , Fernig D. G. , Blanquart C. , Mazurier J. , Legrand D. 
Published: July 2002

ABSTRACTLipopolysaccharides (LPS), either in the free form or complexed to CD14, a LPS receptor, are elicitors of the immune system. Lactoferrin (Lf), a LPS-chelating glycoprotein, protects animals against septic shock. Since optimal protection requires administration of Lf prior to lethal doses of LPS, we hypothesized that interactions between Lf and soluble CD14 (sCD14) exist. In a first step, human sCD14 and human Lf (hLf) were used to determine the kinetic binding parameters of hLf to free sCD14 in an optical biosensor. The results demonstrated that hLf bound specifically and with a high affinity (Kd= 16 ± 7 nM) to sCD14. Affinity chromatography studies showed that hLf interacted not only with free sCD14 but also, though with different binding properties, with sCD14 complexed to LPS or lipid A–2-keto-3-deoxyoctonic acid–heptose. In a second step, we have investigated whether the capacity of hLf to interact with sCD14 could modulate the expression of endothelial-leukocyte adhesion molecule 1 (E-selectin) or intercellular adhesion molecule 1 (ICAM-1) induced by the sCD14-LPS complex on human umbilical vein endothelial cells (HUVEC). Our experiments show that hLf significantly inhibited both E-selectin and ICAM-1 expressions at the surface of HUVEC. In conclusion, these observations suggest that the anti-inflammatory effects of hLf are due not only to the ability of the molecule to chelate LPS but also to its ability to interact with sCD14 and with the sCD14 complexed to LPS, thus modifying the activation of endothelial cells.
Toxoplasma gondii
Homologue of
Plasmodium
Apical Membrane Antigen 1 Is Involved in Invasion of Host Cells
Authors: Hehl Adrian B. , Lekutis Christine , Grigg Michael E. , Bradley Peter J. , Dubremetz Jean-François , Ortega-Barria Eduardo , Boothroyd John C. 
Published: July 2002

ABSTRACT

Proteins with constitutive or transient localization on the surface of
Apicomplexa
parasites are of particular interest for their potential role in the invasion of host cells. We describe the identification and characterization of TgAMA1, the
Toxoplasma gondii
homolog of the
Plasmodium
apical membrane antigen 1 (AMA1), which has been shown to elicit a protective immune response against merozoites dependent on the correct pairing of its numerous disulfide bonds. TgAMA1 shows between 19% (
Plasmodium berghei
) and 26% (
Plasmodium yoelii
) overall identity to the different
Plasmodium
AMA1 homologs and has a conserved arrangement of 16 cysteine residues and a putative transmembrane domain, indicating a similar architecture. The single-copy
TgAMA1
gene is interrupted by seven introns and is transcribed into an mRNA of ∼3.3 kb. The TgAMA1 protein is produced during intracellular tachyzoite replication and initially localizes to the micronemes, as determined by immunofluorescence assay and immunoelectron microscopy. Upon release of mature tachyzoites, TgAMA1 is found distributed predominantly on the apical end of the parasite surface. A ∼54-kDa cleavage product of the large ectodomain is continuously released into the medium by extracellular parasites. Mouse antiserum against recombinant TgAMA1 blocked invasion of new host cells by approximately 40%. This and our inability to produce a viable TgAMA1 knock-out mutant indicate that this phylogenetically conserved protein fulfills a key function in the invasion of host cells by extracellular
T. gondii
tachyzoites.
Epithelial Cells Infected withChlamydophila pneumoniae(Chlamydia pneumoniae) Are Resistant to Apoptosis
Authors: Rajalingam Krishnaraj , Al-Younes Hesham , Müller Anne , Meyer Thomas F. , Szczepek Agnes J. , Rudel Thomas 
Published: July 2002

ABSTRACTThe obligate intracellular pathogenChlamydophila pneumoniae(Chlamydia pneumoniae) initiates infections in humans via the mucosal epithelia of the respiratory tract. Here, we report that epithelial cells infected withC. pneumoniaeare resistant to apoptosis induced by treatment with drugs or by death receptor ligation. The induction of protection from apoptosis depended on the infection conditions since only cells containing large inclusions were protected. The underlying mechanism of infection-induced apoptosis resistance probably involves mitochondria, the major integrators of apoptotic signaling. In the infected cells, mitochondria did not respond to apoptotic stimuli by the release of apoptogenic factors required for the activation of caspases. Consequently, active caspase-3 was absent in infected cells. Our data suggest a direct modulation of apoptotic pathways in epithelial cells byC. pneumoniae.
Human Lactoferrin and Peptides Derived from Its N Terminus Are Highly Effective against Infections with Antibiotic-Resistant Bacteria
Authors: Nibbering P. H. , Ravensbergen E. , Welling M. M. , van Berkel L. A. , van Berkel P. H. C. , Pauwels E. K. J. , Nuijens J. H. 
Published: July 2002

ABSTRACT

Since human lactoferrin (hLF) binds to bacterial products through its highly positively charged N terminus, we investigated which of the two cationic domains is involved in its bactericidal activity. The results revealed that hLF lacking the first three residues (hLF
−3N
) was less efficient than hLF in killing of antibiotic-resistant
Staphylococcus aureus, Listeria monocytogenes
, and
Klebsiella pneumoniae
. Both hLF preparations failed to kill
Escherichia coli
O54. In addition, hLF
−3N
was less effective than hLF in reducing the number of viable bacteria in mice infected with antibiotic-resistant
S. aureus
and
K. pneumoniae
. Studies with synthetic peptides corresponding to the first 11 N-terminal amino acids, designated hLF(1–11), and fragments thereof demonstrated that peptides lacking the first three N-terminal residues are less effective than hLF(1–11) in killing of bacteria. Furthermore, a peptide corresponding to residues 21 to 31, which comprises the second cationic domain, was less effective than hLF(1–11) in killing of bacteria in vitro and in mice having an infection with antibiotic-resistant
S. aureus
or
K. pneumoniae
. Using fluorescent probes, we found that bactericidal hLF peptides, but not nonbactericidal peptides, caused an increase of the membrane permeability. In addition, hLF killed the various bacteria, most probably by inducing intracellular changes in these bacteria without affecting the membrane permeability. Together, hLF and peptides derived from its N terminus are highly effective against infections with antibiotic-resistant
S. aureus
and
K. pneumoniae
, and the first two arginines play an essential role in this activity.
Characterization ofHaemophilus ducreyi-Specific T-Cell Lines from Lesions of Experimentally Infected Human Subjects
Authors: Gelfanova Valentina , Humphreys Tricia L. , Spinola Stanley M. 
Published: July 2002

ABSTRACTHaemophilus ducreyiis the etiologic agent of chancroid, a sexually transmitted genital ulcer disease that facilitates the transmission of human immunodeficiency virus. In the human model of infection, the histopathology of infected sites in part resembles a delayed-type hypersensitivity (DTH) response. In this study, T cells were isolated from skin biopsy specimens obtained from 24 subjects who were infected for 7 to 14 days. One clone and 12 lines that responded toH. ducreyiantigens were obtained from 12 of the subjects. Fluorescence-activated cell sorter analysis showed that the antigen-responsive lines and clone were predominantly CD3+and CD4+. The lines and clone responded toH. ducreyiantigen in a dose-dependent manner and produced gamma interferon (IFN-γ) alone or IFN-γ and interleukin-10 (IL-10) but no IL-4 or IL-5 in response toH. ducreyi. Proliferation of T cells was dependent on the presence of autologous antigen-presenting cells. The lines showed little response to antigens prepared from other members of thePasteurellaceaeand responded to different fractions ofH. ducreyiseparated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We conclude that T cells that recognizeH. ducreyiantigens are recruited to sites experimentally infected with the organism. The lack of cross-reactivity to thePasteurellaceaeand the response of the lines to different antigen fractions suggest that subjects are sensitized toH. ducreyiduring the course of infection.
Expression of Genes Encoding Th1 Cell-Activating Cytokines and Lymphoid Homing Chemokines by Chlamydia-Pulsed Dendritic Cells Correlates with Protective Immunizing Efficacy
Authors: Shaw Jennifer H. , Grund Vernon R. , Durling Luke , Caldwell Harlan D. 
Published: July 2002

ABSTRACT

We studied the expression of cytokines, chemokines, and chemokine receptors by the RNase protection assay in chlamydia-pulsed dendritic cells to better understand their potent anti-chlamydial immunizing properties. We found that chlamydia-pulsed dendritic cells express a complex profile of inflammatory and immunomodulatory molecules. These include CCR-7, interleukin-12, and interferon-induced protein 10, molecules that might influence the homing of pulsed dendritic cells to the site of chlamydial infection and the induction of a local protective CD4
+
Th1 cellular immunity.
Effects of Nonsteroidal Anti-Inflammatory Drugs on
Helicobacter pylori
-Infected Gastric Mucosae of Mice: Apoptosis, Cell Proliferation, and Inflammatory Activity
Authors: Kim Tae Il , Lee Yong Chan , Lee Kwang Hyoung , Han Jae Ho , Chon Chae Yoon , Moon Young Myoung , Kang Jin Kyung , Park In Suh 
Published: July 2002

ABSTRACT

Helicobacter pylori
and nonsteroidal anti-inflammatory drugs (NSAIDs) are two well-known important causative factors of gastric damage. While
H. pylori
increases apoptosis and the proliferation of gastric epithelial cells and is an important factor in peptic ulcer and gastric cancer, NSAIDs induce cell apoptosis and have antineoplastic effects. We investigated the effects of NSAIDs (a nonselective cyclooxygenase [COX] inhibitor [indomethacin] and a selective COX-2 inhibitor [NS-398]) on the apoptosis and proliferation of gastric epithelial cells and gastric inflammation in
H. pylori
-infected mice. C57BL/6 mice were sacrificed 8 weeks after
H. pylori
SS1 inoculation. Indomethacin (2 mg/kg) or NS-398 (10 mg/kg) was administered subcutaneously once daily for 10 days before sacrifice. The following were assessed: gastric inflammatory activity, gastric COX protein expression by Western blotting; gastric prostaglandin E
2
levels by enzyme immunoassay, apoptosis by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, and cell proliferation by Ki67 immunostaining. Compared to the controls,
H. pylori
infection and/or NSAID treatment increased COX-1 and COX-2 protein expression. Gastric prostaglandin E
2
levels, apoptotic index, cell proliferation index, neutrophil activity, and the degree of chronic inflammation were all increased by
H. pylori
infection, and these effects were significantly decreased by indomethacin treatment. However, NS-398 treatment after
H. pylori
infection did not induce a significant reduction, although it did result in a tendency to decrease. These results show that NSAIDs can reverse the increased apoptosis and proliferation of epithelial cells and inflammatory activity in the stomachs of
H. pylori
-infected mice and that, like COX-2 activation, COX-1 induction contributes to the change of gastric mucosal cell turnover and inflammation induced by
H. pylori
infection.
Induction of Specific Cytotoxic Lymphocytes in Mice Vaccinated withBrucella abortusRB51
Authors: He Yongqun , Vemulapalli Ramesh , Zeytun Ahmet , Schurig Gerhardt G. 
Published: July 2002

ABSTRACTA safe, more sensitive, nonradioactive, neutral red uptake assay was adopted to replace the traditional51Cr release assay for detection ofBrucella-specific cytotoxic T lymphocyte (CTL) activity. Our studies indicated thatBrucella abortusstrain RB51 vaccination of mice induced specific CTLs against both strain RB51- and strain 2308-infected J774.A1 macrophages but not againstListeria monocytogenes-infected J774.A1 cells. The antigen-specific cytotoxic activity was exerted by T lymphocytes but not by NK cells. CD3+CD4+T cells secreted the highest level of gamma interferon (IFN-γ) and were able to exert a low but significant level of specific lysis ofBrucella-infected macrophages. They also exerted a low level of nonspecific lysis of noninfected macrophages. In contrast, CD3+CD8+T cells secreted low levels of IFN-γ but demonstrated high levels of specific lysis ofBrucella-infected macrophages with no nonspecific lysis. These findings indicate thatB. abortusstrain RB51 vaccination of mice induces specific CTLs and suggest that CD3+CD4+and CD3+CD8+T cells play a synergistic role in the anti-Brucellaactivity.
Analogous Cytokine Responses toBurkholderia pseudomalleiStrains Contrasting in Virulence Correlate with Partial Cross-Protection in Immunized Mice
Authors: Ulett Glen C. , Ketheesan Natkunam , Clair Timothy W. , McElnea Catriona L. , Barnes Jodie L. , Hirst Robert G. 
Published: July 2002

ABSTRACTCytokine mRNA levels were assessed inBurkholderia pseudomallei-susceptible BALB/c mice andB. pseudomallei-resistant C57BL/6 mice following administration of a sublethal dose of less virulent (LV)B. pseudomallei, a candidate immunogen tested for protection against a highly virulent (HV) challenge. Compared on the basis of the bacterial loads, the cytokine patterns induced by HV and LVB. pseudomalleiwere similar, involving gamma interferon, interleukin-10, and other cytokines. Partial cross-protection betweenB. pseudomalleistrains is shown to be associated with cytokine profiles involving both type 1 and type 2 cytokines.
vrrB
, a Hypervariable Open Reading Frame in
Bacillus anthracis
Authors: Schupp James M. , Klevytska Alexandra M. , Zinser Guenevier , Price Lance B. , Keim Paul 
Published: July 2002

ABSTRACT

Bacillus anthracis
appears to be the most molecularly homogeneous bacterial species known. Extensive surveys of worldwide isolates have revealed vanishingly small amounts of genomic variation. The biological importance of the resting-stage spore may lead to very low evolutionary rates and, perhaps, to the lack of potentially adaptive genetic variation. In contrast to the overall homogeneity, some gene coding regions contain hypervariability that is translated into protein variation. During marker analysis of diverse strains, we have discovered a novel ca. 750-nucleotide open reading frame (ORF) that contains in-frame, variable-number tandem-repeat sequences. Four distinct variable regions exist within
vrrB
, giving rise to 11 distinct alleles in eight different length categories among
B. anthracis
strains. This ORF putatively codes for a 241- to 265-amino-acid protein, rich in glutamine (13.2%), glycine (23.4%), and histidine (23.0%). The variable-region amino acids of the
vrrB
ORF are strongly hydrophilic. Coupled with putative transmembrane domains flanking the variable regions, this suggests a membrane-anchored cytosolic or extracellular location for the putative protein. Sequence analysis of the complete ORFs from three
Bacillus cereus
strains shows maintenance of the ORF across species boundaries, including strong conservation of the amino acid sequence and the capacity to vary among strains. The presence of 11 different alleles of the
vrrB
locus is in stark contrast to the near homogeneity of
B. anthracis
. Evolution of hypervariable genes can negate the lack of genetic variability in species such as
B. anthracis
and provide select rapid evolution in other more variable species.
Functional Characterization of the HasA
PF
Hemophore and Its Truncated and Chimeric Variants: Determination of a Region Involved in Binding to the Hemophore Receptor
Authors: Létoffé Sylvie , Omori Kenji , Wandersman Cécile 
Published: July 2002

ABSTRACT

Hemophores are secreted by several gram-negative bacteria (
Serratia marcescens
,
Pseudomonas aeruginosa
,
Pseudomonas fluorescens
, and
Yersinia pestis
) and form a family of homologous proteins. Unlike the
S. marcescens
hemophore (HasA
SM
), the
P. fluorescens
hemophore HasA
PF
has an additional region of 12 residues located immediately upstream from the C-terminal secretion signal. We show that HasA
PF
undergoes a C-terminal cleavage which removes the last 21 residues when secreted from
P. fluorescens
and that only the processed form is able to deliver heme to the
S. marcescens
outer membrane hemophore-specific receptor, HasR
SM
. Functional analysis of variants including those with an internal deletion of the extra C-terminal domain show that the secretion signal does not inhibit the biological activity, whereas the 12-amino-acid region located upstream does. This extra domain may inhibit the interaction of the hemophore with HasR
SM
. To localize the hemophore regions involved in binding to HasR, chimeric HasA
PF
-HasA
SM
proteins were tested for biological activity. We show that residues 153 to 180 of HasA
PF
are necessary for its interaction with the receptor.
A Cyanobacterial Gene,
sqdX
, Required for Biosynthesis of the Sulfolipid Sulfoquinovosyldiacylglycerol
Authors: Güler Sinan , Essigmann Bernd , Benning Christoph 
Published: July 2002

ABSTRACT

The sulfolipid sulfoquinovosyldiacylglycerol is present in the photosynthetic membranes of plants and many photosynthetic bacteria. A novel gene,
sqdX
, essential for sulfolipid biosynthesis in the cyanobacterium
Synechococcus
sp. strain PCC7942 is proposed to encode the cyanobacterial sulfolipid synthase catalyzing the last reaction of the pathway.
Signaling System in
Porphyromonas gingivalis
Based on a LuxS Protein
Authors: Chung Whasun O. , Park Yoonsuk , Lamont Richard J. , McNab Rod , Barbieri Bruno , Demuth Donald R. 
Published: July 2002

ABSTRACT

The
luxS
gene of quorum-sensing
Vibrio harveyi
is required for type 2 autoinducer production. We identified a
Porphyromonas gingivalis
open reading frame encoding a predicted peptide of 161 aa that shares 29% identity with the amino acid sequence of the LuxS protein of
V. harveyi
. Conditioned medium from a late-log-phase
P. gingivalis
culture induced the luciferase operon of
V. harveyi
, but that from a
luxS
insertional mutant did not. In
P. gingivalis
, the expression of
luxS
mRNA was environmentally controlled and varied according to the cell density and the osmolarity of the culture medium. In addition, differential display PCR showed that the inactivation of
P. gingivalis luxS
resulted in up-regulation of a hemin acquisition protein and an arginine-specific protease and reduced expression of a hemin-regulated protein, a TonB homologue, and an excinuclease. The data suggest that the
luxS
gene in
P. gingivalis
may function to control the expression of genes involved in the acquisition of hemin.