bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemokine Receptor CCR5 Δ32 Genetic Analysis Using Multiple Specimen Types and the NucliSens Basic Kit
Authors: Tetali Suryakumari , Lee Eun Mi , Kaplan Mark H. , Romano Joseph W. , Ginocchio Christine C. 
Published: July 2002

ABSTRACT
Resistance to HIV-1 infection and delayed disease progression have been associated with a 32-bp deletion (Δ32) in the gene encoding the CCR5 chemokine receptor. In the present study we describe the modification of a nucleic acid sequence-based amplification (NASBA)-based CCR5 genotyping assay for a NucliSens Basic Kit (Organon Teknika, Durham, N.C.) format using a new target-specific sandwich oligonucleotide detection methodology. The new method permitted the use of generic electrochemiluminescent probes supplied in the NucliSens Basic Kit, whereas the original NASBA method required expensive target-specific ruthenium detection probes. The Basic Kit CCR5 Δ32 genotypic analysis was in 100% concordance with both the original NASBA assay and DNA PCR results. This study also evaluated the use of multiple specimen types, including peripheral blood mononuclear cells (PBMC), whole blood, dried blood spots, buccal scrapings, and plasma, for CCR5 genotype analysis. The sensitivities of the three assays were comparable when PBMC or whole blood was the specimen source. In contrast, when dried blood spots, buccal scrapings, or plasma was used as the sample source, the sensitivity of DNA PCR was 80.95, 42.8, or 0%, respectively, compared to 100% sensitivity obtained with the original NASBA and Basic Kit NASBA assays. Our study indicates that the NucliSens Basic Kit NASBA assay is very sensitive and specific for CCR5 Δ32 genotyping using multiple sample types.
Antibodies against
Streptococcus agalactiae
Proteins c
α
and R4 in Sera from Pregnant Women from Norway and Zimbabwe
Authors: Moyo Sylvester R. , Maeland Johan A. , Mudzori James 
Published: July 2002

ABSTRACT

Group B streptococci (GBS) express strain-variable and surface-localized proteins, which are important serotype markers and targets of protective antibodies. These include the c
α
and R4 proteins, one or the other of which is expressed by approximately 75% of clinical GBS isolates. These proteins have been considered vaccine candidates. In this study, the c
α
and R4 proteins were extracted by trypsin digestion of GBS and purified by sequential precipitation with trichloroacetic acid and ammonium sulfate followed by gel filtration chromatography. The proteins were used as antigens in an indirect enzyme-linked immunosorbent assay (ELISA) to measure the levels of c
α
- and R4-reactive antibodies in sera from pregnant women from Norway (
n
= 100) and from Zimbabwe (
n
= 124). Antibody levels in the Norwegian group of women were significantly higher than in the Zimbabwean group, and a higher proportion of the Norwegian women contained appreciable levels of antibodies against both proteins. The antibodies traversed the placental barrier. With individual sera, a significant correlation between the anti-c
α
and anti-R4 antibody levels was observed and each of the two protein antigens effectively competed for human serum antibodies both against itself and against the other antigen. Inhibition ELISA results demonstrated specificity for each of the proteins of immune antibodies raised in rabbits. These results demonstrate that (i) the majority of women of childbearing age have antibodies against c
α
and R4, (ii) the levels of these antibodies differ among pregnant women in different parts of the world, and (iii) the normal human serum antibodies may target a common c
α
and R4 protein site, whereas immune antibodies targeted a different site(s) specific for each protein.
Schistosomiasis in the People's Republic of China: Prospects and Challenges for the 21st Century
Authors: Ross Allen G. P. , Sleigh Adrian C. , Li Yuesheng , Davis George M. , Williams Gail M. , Jiang Zheng , Feng Zheng , McManus Donald P. 
Published: July 2002

SUMMARYSchistosomiasis japonica is a serious communicable disease and a major disease risk for more than 30 million people living in the tropical and subtropical zones of China. Infection remains a major public health concern despite 45 years of intensive control efforts. It is estimated that 865,000 people and 100,250 bovines are today infected in the provinces where the disease is endemic, and its transmission continues. Unlike the other schistosome species known to infect humans, the oriental schistosome, Schistosoma japonicum, is a true zoonotic organism, with a range of mammalian reservoirs, making control efforts extremely difficult. Clinical features of schistosomiasis range from fever, headache, and lethargy to severe fibro-obstructive pathology leading to portal hypertension, ascites, and hepatosplenomegaly, which can cause premature death. Infected children are stunted and have cognitive defects impairing memory and learning ability. Current control programs are heavily based on community chemotherapy with a single dose of the drug praziquantel, but vaccines (for use in bovines and humans) in combination with other control strategies are needed to make elimination of the disease possible. In this article, we provide an overview of the biology, epidemiology, clinical features, and prospects for control of oriental schistosomiasis in the People's Republic of China.
Role of Lipopolysaccharide Phase Variation in Susceptibility of
Haemophilus influenzae
to Bactericidal Immunoglobulin M Antibodies in Rabbit Sera
Authors: Erwin Alice L. , Brewah Yambasu A. , Couchenour Debra A. , Barren Philip R. , Burke Stephen J. , Choi Gil H. , Lathigra Raju , Hanson Mark S. , Weiser Jeffrey N. 
Published: July 2002

ABSTRACT

The effect of phase variation of lipopolysaccharide (LPS) structure on the susceptibility of
Haemophilus influenzae
to complement-dependent killing by normal human sera and normal rat sera has been described previously. The phase-variable structure phosphorylcholine (ChoP) confers susceptibility to human serum, since ChoP on the bacterial cell surface binds to serum C-reactive protein and activates complement. In contrast, expression of galα1,4gal, a second phase-variable epitope that is also found on human glycoconjugates, confers resistance to human serum. We studied the role of phase variation of these structures in the susceptibilities of
H. influenzae
KW20 (Rd) and a clinical isolate of nontypeable
H. influenzae
to killing by rabbit sera, which often possess naturally acquired complement-dependent bactericidal activity for unencapsulated
H. influenzae
. Expression of ChoP increased the resistance of strain KW20 to killing by bactericidal rabbit sera. In contrast, the serum resistance of a clinical isolate, H233, was unaffected by ChoP expression but was reduced by galα1,4gal expression. The rabbit sera with bactericidal activity (but not the nonbactericidal sera) all contained immunoglobulin M (IgM) antibodies able to bind to the surface of
H. influenzae
bacteria, as detected by flow cytometry, and contained IgM antibodies to LPS purified from strain KW20. Preincubation of sera with LPS reduced their bactericidal activity. Bactericidal activity was recovered quantitatively in an IgM-enriched fraction of sera. It is concluded that naturally occuring bactericidal activity for unencapsulated
H. influenzae
is largely due to IgM antibodies directed against phase-variable structures of the LPS.
Genetic Relatedness and Superantigen Expression in Group A Streptococcus Serotype M1 Isolates from Patients with Severe and Nonsevere Invasive Diseases
Authors: Chatellier Sonia , Ihendyane Nahla , Kansal Rita G. , Khambaty Farukh , Basma Hesham , Norrby-Teglund Anna , Low Donald E. , McGeer Allison , Kotb Malak 
Published: July 2002

ABSTRACTThe relatedness of group A streptococcal (GAS) strains isolated from 35 Canadian patients with invasive disease of different severity was investigated by a variety of molecular methods. All patients were infected with M1T1 strains and, based on clinical criteria, were classified as severe (n= 21) and nonsevere (n= 14) invasive GAS infection cases. All the M1 strains studied had theemm1.0 allele and the same streptococcal pyrogenic exotoxin (Spe) genotype,speA+speB+speC speF+speG+speH smeZ+ssa. All isolates had the samespeAallotype,speA2. The randomly amplified polymorphic DNA banding pattern with two different primers was identical for all strains, and pulsed field gel electrophoresis analysis showed that 33 and 30 isolates had identical banding patterns after DNA digestion withSfiI orSmaI, respectively; the nonidentical isolates differed from the main pattern by only one band. A relatively high degree of polymorphism in specific regions of thesicgene was observed among isolates; however, this polymorphism was not associated with disease severity. Likewise, although the phenotypic expression of SpeA, SpeB, and SpeF proteins varied among the M1T1 isolates, there was no correlation between the amount of Spe expressed and disease severity. Importantly, mitogenic and cytokine responses induced by partially purified bacterial culture supernatants containing a mixture of expressed superantigens were very similar for isolates from severe and nonsevere cases (P> 0.1). Together, the data indicate that highly related invasive M1T1 isolates, some indistinguishable, can cause disease of varying severity in different individuals. These findings underscore the contribution of host factors to the outcome of invasive GAS infections.
Analysis of Pilus Adhesins from
Haemophilus influenzae
Biotype IV Strains
Authors: Clemans Daniel L. , Marrs Carl F. , Bauer Richard J. , Patel Mayurika , Gilsdorf Janet R. 
Published: July 2002

ABSTRACT

A subset of nontypeable
Haemophilus influenzae
(NTHI) biotype IV isolates from the human genital tract or from infected newborn infants forms a cryptic genospecies characterized by, among other features, the presence of peritrichous pili. The objective of this study was to determine the similarity of these pili to hemagglutinating, HifA- and HifE-containing pili expressed by respiratory
H. influenzae
isolates. For this analysis, the presence of
hifA
and
hifE
and their gene products in NTHI biotype IV strains was assessed, the binding of
H. influenzae
biotype IV strains to human epithelial cells was characterized, possible genital tissue tropism of these isolates was explored, and the role of HifA- and HifE-possessing pili in the adhesion of NTHI biotype IV strains to human epithelial cells was determined. None of the six biotype IV NTHI isolates tested agglutinated human red blood cells, nor could they be enriched for hemagglutinating variants. Although
hifA
, which encodes the major structural subunit of hemagglutinating pili, and
hifE
, which encodes the tip adhesin of hemagglutinating pili, were detected by PCR from six and five, respectively, of the six biotype IV strains tested, neither HifA nor HifE (the gene products of
hifA
and
hifE
) were detected in any of these strains by Western blot analysis using antisera that recognize HifA and HifE of respiratory strains. Transmission electron microscopy showed no surface pili on the two biotype IV
H. influenzae
isolates examined; strain 4162 containing an insertional mutation in
hifA
also showed no surface pili, whereas strain 1595 containing an insertional mutation in
hifB
showed pilus-like structures that were shorter and thicker than hemagglutinating pili of the respiratory strains AAr176 and M43. In enzyme-linked immunosorbent assays, biotype IV strains adhered to 16HBE14o
−
and HEp-2 cells of respiratory origin as well as to ME180 and HeLa cells of genital origin. This adherence was not pilus specific, however, as GM-1, a known pilus receptor analog, did not inhibit binding of biotype IV strains to ME180, HEp-2, or HeLa cells, and GM-1 inhibition of binding to 16HBE14o
−
cells did not correlate with the presence of
hifE
. While both nonpiliated variants and
hifA
and
hifB
(encoding the pilus chaperone) mutants of respiratory strain AAr176 showed reduced binding (64 to 87% of that of piliated AAr176) to 16HBE14o
−
and ME180 cells,
hifA
and
hifB
mutants of the biotype IV strains showed minimal reduction in binding to these cell lines (91 to 98% of that of wild-type strains). Thus, although biotype IV
H. influenzae
isolates of the cryptic genospecies possess the genes that code for HifA- and HifE-containing hemagglutinating pili, epithelial cell adherence exhibited by these strains is not mediated by expression of hemagglutinating pili.
A 4.1-Kilodalton Polypeptide in the Cultural Supernatant of
Mycoplasma fermentans
Is One of the Substances Responsible for Induction of Interleukin-6 Production by Human Gingival Fibroblasts
Authors: Hasebe Akira , Shibata Ken-Ichiro , Watanabe Tsuguo 
Published: July 2002

ABSTRACT

The cultural supernatant of
Mycoplasma fermentans
induced interleukin-6 production by human gingival fibroblasts. The active entities were divided into hydrophilic and hydrophobic substances. In this study, we purified a 4.1-kilodalton polypeptide from the hydrophilic substances. It reacted with polyclonal antibodies to
M. fermentans
and activated human macrophages.
Identification, Characterization, and Variation in Expression of Two Serologically Distinct O-Antigen Epitopes in Lipopolysaccharides of
Campylobacter fetus
Serotype A Strains
Authors: Brooks Brian W. , Robertson Ruth H. , Lutze-Wallace Cheryl L. , Pfahler Wolfram 
Published: July 2002

ABSTRACT

Monoclonal antibodies (MAbs) to the lipopolysaccharide (LPS) O-antigens of
Campylobacter fetus
serotype A and B strains were produced. Eight MAbs specific for serotype A LPS were characterized on immunoblots of
C. fetus
serotype A LPS. Two immunoblot patterns were observed and were used to divide the eight MAbs into two groups. MAbs M1177 and M1194 were selected as representative of the two groups and were used in an enzyme-linked immunosorbent assay (ELISA) to examine the LPS O-antigen epitopes of 37 serotype A
C. fetus
subsp.
fetus
and C.
fetus
subsp.
venerealis
strains. Thirty-three strains (89%) reacted with both M1177 and M1194, 2 strains reacted only with M1177, and 2 strains reacted only with M1194. To further characterize the O-antigen epitopes, purified serotype A LPS was treated using various temperature and pH conditions and the effect of the treatments on the reactivity of the LPS with MAbs M1177 and M1194 was evaluated by ELISA. While no difference among several treatments was observed, heating serotype A LPS under alkaline conditions decreased the reaction with M1177 to background levels and increased the reaction with M1194. MAbs M1177 and M1194 were also used with ELISA to investigate in vivo and in vitro expression of the two O-antigen epitopes. There was substantial variation in expression of the two epitopes among weekly isolates of two
C. fetus
serotype A strains recovered from experimentally infected heifers. There was minimal variation in expression of the two epitopes in successive subcultures of three
C. fetus
serotype A strains.
Secretion of Listeriolysin by
Brucella suis
Inhibits Its Intramacrophagic Replication
Authors: Köhler Stephan , Layssac Marion , Naroeni Aroem , Gentschev Ivaylo , Rittig Michael , Liautard Jean-Pierre 
Published: July 2002

ABSTRACT

The introduction into
Brucella suis
1330 of a plasmid allowing the heterologous expression of a hybrid cytolysin containing listeriolysin from
Listeria monocytogenes
, and its export via the
Escherichia coli
hemolysin secretion pathway, resulted in secretion of active listeriolysin monitored by erythrocyte lysis. In contrast to observations with the nonhemolytic control strain, the phagosomes of infected human monocytes containing the hemolytic
B. suis
were partially disrupted, and this strain failed to multiply in human macrophage-like cells. These results added strong evidence supporting the proposal that the phagosome of the macrophage was the predominant niche of brucellae in their mammalian hosts.
Francisella tularensisInduces Cytopathogenicity and Apoptosis in Murine Macrophages via a Mechanism That Requires Intracellular Bacterial Multiplication
Authors: Lai Xin-He , Golovliov Igor , Sjöstedt Anders 
Published: July 2002

ABSTRACTThe murine macrophage-like cell line J774.A1 ingests and allows intracellular growth ofFrancisella tularensis. We demonstrate that, after 24 h of infection, a pronounced cytopathogenicity resulted and the J774 cells were undergoing apoptosis. Despite this host cell apoptosis, no decrease in bacterial numbers was observed. When internalization of bacteria was prevented or intracellularly locatedF. tularensisbacteria were eradicated within 12 h, the progression of host cell cytopathogenicity and apoptosis was prevented.
Nickel-Responsive Induction of Urease Expression in
Helicobacter pylori
Is Mediated at the Transcriptional Level
Authors: van Vliet Arnoud H. M. , Kuipers Ernst J. , Waidner Barbara , Davies Beverly J. , de Vries Nicolette , Penn Charles W. , Vandenbroucke-Grauls Christina M. J. E. , Kist Manfred , Bereswill Stefan , Kusters Johannes G. 
Published: July 2002

ABSTRACT

The nickel-containing enzyme urease is an essential colonization factor of the gastric pathogen
Helicobacter pylori
, as it allows the bacterium to survive the acidic conditions in the gastric mucosa. Although urease can represents up to 10% of the total protein content of
H. pylori
, expression of urease genes is thought to be constitutive. Here it is demonstrated that
H. pylori
regulates the expression and activity of its urease enzyme as a function of the availability of the cofactor nickel. Supplementation of brucella growth medium with 1 or 100 μM NiCl
2
resulted in up to 3.5-fold-increased expression of the urease subunit proteins UreA and UreB and up to 12-fold-increased urease enzyme activity. The induction was specific for nickel, since the addition of cadmium, cobalt, copper, iron, manganese, or zinc did not affect the expression of urease. Both Northern hybridization studies and a transcriptional
ureA
::
lacZ
fusion demonstrated that the observed nickel-responsive regulation of urease is mediated at the transcriptional level. Mutation of the HP1027 gene, encoding the ferric uptake regulator (Fur), did not affect the expression of urease in unsupplemented medium but reduced the nickel induction of urease expression to only twofold. This indicates that Fur is involved in the modulation of urease expression in response to nickel. These data demonstrate nickel-responsive regulation of
H. pylori
urease, a phenomenon likely to be of importance during the colonization and persistence of
H. pylori
in the gastric mucosa.
Intimin, Tir, and Shiga Toxin 1 Do Not Influence Enteropathogenic Responses to Shiga Toxin-Producing
Escherichia coli
in Bovine Ligated Intestinal Loops
Authors: Stevens Mark P. , Marchès Olivier , Campbell June , Huter Veronika , Frankel Gad , Phillips Alan D. , Oswald Eric , Wallis Timothy S. 
Published: July 2002

ABSTRACT

Shiga toxin-producing
Escherchia coli
(STEC) comprises a group of attaching and effacing (A/E) enteric pathogens of animals and humans. Natural and experimental infection of calves with STEC may result in acute enteritis or subclinical infection, depending on serotype- and host-specific factors. To quantify intestinal secretory and inflammatory responses to STEC in the bovine intestine, serotypes that are associated with human disease (O103:H2 and O157:H7) were introduced into ligated mid-ileal loops in gnotobiotic and conventional calves, and fluid accumulation and recruitment of radiolabeled neutrophils were measured after 12 h. STEC serotype O103:H2, but not serotype O157:H7, elicited strong enteropathogenic responses. To determine if the inflammatory response to STEC O103:H2 in calves requires Shiga toxin 1 or intimate bacterial attachment to the intestinal epithelium, defined mutations were made in the
stx1
,
eae
, and
tir
genes. Our data indicate that some STEC induce intestinal inflammatory responses in calves by a mechanism that is independent of A/E-lesion formation, intimin, or Shiga toxin 1. This may have implications for strategies to reduce STEC carriage in cattle.
Characterization of the Mouse Beta Defensin 1,
Defb1
, Mutant Mouse Model
Authors: Morrison Gillian , Kilanowski Fiona , Davidson Donald , Dorin Julia 
Published: July 2002

ABSTRACT

Beta defensins are small cationic antimicrobial peptides present in the respiratory system which have been proposed to be dysfunctional in the environment of the cystic fibrosis lung.
Defb1
, a murine homologue to the human beta defensins, has also been found to be expressed in the respiratory system and, in order to examine the function of beta defensins in vivo, gene targeting was used to generate
Defb1
-deficient (
Defb1
tm1Hgu
/

Defb1
tm1Hgu

[
Defb1
−/−
]) mice. The Defb1 synthetic peptide was shown to have a salt-sensitive antimicrobial activity that was stronger against
Staphylococcus aureus
than against
Escherichia coli
or
Pseudomonas aeruginosa. Defb1
−/−
mice were found, however, to be effective in the clearance of the cystic fibrosis relevant pathogen
S. aureus
from the airways after nebulization. Although no overt deleterious phenotype was evident in the
Defb1
−/−
mice, the number of mutant mice found to harbor bacteria of the
Staphylococcus
species in the bladder was significantly higher (
P
= 0.008) than that of controls, suggesting a role for these peptides in resistance to urinary tract infection.
Improved Tuberculosis DNA Vaccines by Formulation in Cationic Lipids
Authors: D'Souza S. , Rosseels V. , Denis O. , Tanghe A. , De Smet N. , Jurion F. , Palfliet K. , Castiglioni N. , Vanonckelen A. , Wheeler C. , Huygen K. 
Published: July 2002

ABSTRACTMice were vaccinated with plasmid DNA (pDNA) encoding antigen 85A (Ag85A), Ag85B, or PstS-3 fromMycobacterium tuberculosiseither in saline or formulated for intramuscular injections in VC1052:DPyPE (aminopropyl-dimethyl-myristoleyloxy-propanaminium bromide-diphytanoylphosphatidyl-ethanolamine) (Vaxfectin; Vical, Inc., San Diego, Calif.) or for intranasal instillations in GAP-DLRIE:DOPE (aminopropyl-dimethyl-bis-dodecyloxy-propanaminium bromide-dioleoylphosphatidyl-ethanolamine). These two novel cationic and neutral colipid formulations were previously reported to be effective adjuvants for pDNA-induced antibody responses. The levels of Ag85-specific total immunoglobulin G (IgG) and IgG isotypes were all increased 3- to 10-fold by formulation of pDNA in Vaxfectin. The level of production of splenic T-cell-derived Th1-type cytokines (interleukin-2 and gamma interferon) in response to purified Ag85 and to synthetic peptides spanning the entire Ag85A protein was also significantly higher in animals vaccinated with pDNA formulated in Vaxfectin. Cytolytic T-lymphocyte responses generated by pDNA encoding phosphate-binding protein PstS-3 in Vaxfectin were better sustained over time than were those generated by PstS-3 DNA in saline. Intranasal immunization with Ag85A DNA in saline was completely ineffective, whereas administration in GAP-DLRIE:DOPE induced a positive Th1-type cytokine response; however, the extent of the latter response was clearly lower than that obtained following intramuscular immunization with the same DNA dose. Combined intramuscular and intranasal administrations in cationic lipids resulted in stronger immune responses in the spleen and, more importantly, in the lungs as well. Finally, formulation in Vaxfectin increased the protective efficacy of the Ag85B DNA vaccine, as measured by reduced relative light unit counts and CFU counts in the spleen and lungs from mice challenged with bioluminescentM. tuberculosisH37Rv. These results may be of importance for future clinical use of DNA vaccines in humans.