bluuebunny/crossref_metadata_2025_split huggingface dataset:
Earlier Detection of Human Immunodeficiency Virus Type 1 p24 Antigen and Immunoglobulin G and M Antibodies to p17 Antigen in Seroconversion Serum Panels by Immune Complex Transfer Enzyme Immunoassays
Authors: Hashida Seiichi , Ishikawa Setsuko , Hashinaka Kazuya , Nishikata Ichiro , Oka Shinichi , Ishikawa Eiji 
Published: July 2002

ABSTRACT
For earlier diagnosis of human immunodeficiency virus type 1 (HIV-1) infection, the sensitivities of immune complex transfer enzyme immunoassays for HIV-1 p24 antigen and antibody immunoglobulin G (IgG) to HIV-1 p17 antigen were improved approximately 25- and 90-fold, respectively, over those of the previous immunoassays by performing solid-phase immunoreactions with shaking and increasing the serum sample volumes, and immune complex transfer enzyme immunoassay of antibody IgM to p17 antigen was also performed in the same way as the improved immunoassay of antibody IgG to p17 antigen. By the improved immunoassays, p24 antigen and antibody IgG to p17 antigen were detected earlier in 32 and 53%, respectively, of the HIV-1 seroconversion serum panels tested than before the improvements, and p24 antigen was detected as early as or earlier than HIV-1 RNA by reverse transcriptase-PCR (RT-PCR) in all of the panels tested. In 4 panels out of 19 tested, antibody IgG to p17 antigen or both antibodies IgG and IgM to p17 antigen were detected earlier than p24 antigen and RNA, although the antibody levels declined slightly before their steep increases usually observed after p24 antigen and RNA. Thus, the window period in diagnosis of HIV-1 infection can be shortened by detection of p24 antigen with the improved immunoassay as much as by detection of RNA with RT-PCR and, in some cases, more by detection of antibodies IgG and IgM to p17 antigen with the improved immunoassays than by detections of p24 antigen with the improved immunoassay and RNA with RT-PCR.
Pretreatment of Whole Blood for Use in Immunochromatographic Assays for Hepatitis B Virus Surface Antigen
Authors: Shin Hyeong-soon , Kim Chang-kyu , Shin Kwang-soon , Chung Hong-keun , Heo Tae-ryeon 
Published: July 2002

ABSTRACT

Immunochromatographic assays (ICAs) are also referred to as rapid tests, since they are simple and the results can be obtained within minutes after manually loading a few drops of a sample into each sample well of the test device. However, whole blood cannot be tested with ICA kits due to the visual hindrance caused by the color of red blood cells (RBCs), unless a cell-removing device such as a filter is mounted on the kits. Thus, when testing with blood, the advantage of the ICA kit is lost because of the additional time and machines required to coagulate and separate whole blood before preparing the serum. To overcome this limitation, whole-blood samples were added to a pretreatment solution to decolor the RBCs; the resulting mixtures were then loaded into the sample wells of the test device. The pretreating solution was composed of hydrogen peroxide (H
2
O
2
) to decolor the RBCs, Sag 471 (Osi Specialties) to restrain the mixture from vigorous foaming, sodium azide (NaN
3
) to inhibit the enzyme, which generates excessive foam at the beginning of decolorization, and EDTA as a chelating agent. As a result of this pretreatment, whole blood could be used with the ICA kit without reducing its simplicity and rapidity.
Detection of Immunologically Significant Factors for Chronic Fatigue Syndrome Using Neural-Network Classifiers
Authors: Hanson S. J. , Gause W. , Natelson B. 
Published: July 2002

ABSTRACTNeural-network classifiers were used to detect immunological differences in groups of chronic fatigue syndrome (CFS) patients that heretofore had not shown significant differences from controls. In the past linear methods were unable to detect differences between CFS groups and non-CFS control groups in the nonveteran population. An examination of the cluster structure for 29 immunological factors revealed a complex, nonlinear decision surface. Multilayer neural networks showed an over 16% improvement in ann-fold resampling generalization test on unseen data. A sensitivity analysis of the network found differences between groups that are consistent with the hypothesis that CFS symptoms are a consequence of immune system dysregulation. Corresponding decreases in the CD19+B-cell compartment and the CD34+hematopoietic progenitor subpopulation were also detected by the neural network, consistent with the T-cell expansion. Of significant interest was the fact that, of all the cytokines evaluated, the only one to be in the final model was interleukin-4 (IL-4). Seeing an increase in IL-4 suggests a shift to a type 2 cytokine pattern. Such a shift has been hypothesized, but until now convincing evidence to support that hypothesis has been lacking.
Production ofBartonellaGenus-Specific Monoclonal Antibodies
Authors: Liang Zhongxing , La Scola Bernard , Lepidi Hubert , Raoult Didier 
Published: July 2002

ABSTRACTMonoclonal antibodies (MAbs) which react with heat-resistant proteins with molecular masses of 32 to 33 kDa of 14 differentBartonellaspecies were produced. These antibodies did not react with antigens of 26 diverse bacterial strains by microimmunofluorescence assay except MAb B3D4, which reacted withChlamydia psittaciandChlamydia trachomatisat low titers. The identification of a commonBartonellaantigenic protein will make it possible to later produce a diagnostic antigen by cloning and expressing it inEscherichia coli. Moreover, these MAbs allow allBartonellaspecies to be identified to the genus level.
Molecular Properties, Biology, and Clinical Implications of TT Virus, a Recently Identified Widespread Infectious Agent of Humans
Authors: Bendinelli Mauro , Pistello Mauro , Maggi Fabrizio , Fornai Claudia , Freer Giulia , Vatteroni Maria Linda 
Published: July 2002

SUMMARY
TT virus (TTV) was first described in 1997 by representational difference analysis of sera from non-A to non-G posttransfusion hepatitis patients and hence intensively investigated as a possible addition to the list of hepatitis-inducing viruses. The TTV genome is a covalently closed single-stranded DNA of approximately 3.8 kb with a number of characteristics typical of animal circoviruses, especially the chicken anemia virus. TTV is genetically highly heterogeneous, which has led investigators to group isolates into numerous genotypes and subtypes and has limited the sensitivity of many PCR assays used for virus detection. The most remarkable feature of TTV is the extraordinarily high prevalence of chronic viremia in apparently healthy people, up to nearly 100% in some countries. The original hypothesis that it might be an important cause of cryptogenic hepatitis has not been borne out, although the possibility that it may produce liver damage under specific circumstances has not been excluded. The virus has not yet been etiologically linked to any other human disease. Thus, TTV should be considered an orphan virus.
Chlamydia pneumoniae
and Atherosclerosis: Critical Assessment of Diagnostic Methods and Relevance to Treatment Studies
Authors: Boman Jens , Hammerschlag Margaret R. 
Published: July 2002

SUMMARY
A number of studies have found that inflammation of the vessel wall plays an essential role in both the initiation and progression of atherosclerosis and erosion and fissure and the eventual rupture of plaques. Chlamydia pneumoniae is one of the infectious agents that have been investigated as possible causes of this inflammation. Initial studies of the association of C. pneumoniae and cardiovascular disease (CVD) were seroepidemiologic, and these were followed by studies in which the organism was identified in vascular tissue from patients with CVD by electron microscopy, PCR and immunocytochemical staining (ICC). C. pneumoniae has also been isolated by culture from vascular tissue in a small number patients. However, no single serologic, PCR, or ICC assay has been used consistently across all studies. The assays used are also not standardized. Recent studies of serologic and PCR assays for diagnosis of C. pneumoniae infection have suggested that there may be substantial interlaboratory variation in the performance of these tests. It now appears that some of the inconsistency of results from study to study may be due, in part, to lack of standardized methods. Although initial seroepi-demiologic studies demonstrated a significantly increased risk of adverse cardiac outcome in patients who were seropositive, subsequent prospective studies found either small or no in-creased risk. In addition to the lack of consistent serologic criteria, recent evaluations have demonstrated inherent problems with performance of the most widely used serologic methods. Most importantly, we do not have a reliable serologic marker for chronic or persistent C. pneumoniae infection.
Clostridium perfringens
Beta-Toxin Forms Potential-Dependent, Cation-Selective Channels in Lipid Bilayers
Authors: Shatursky Oleg , Bayles Robert , Rogers Marianne , Jost B. Helen , Songer J. Glenn , Tweten Rodney K. 
Published: July 2002

ABSTRACT

Recombinant beta-toxin from
Clostridium perfringens
type C was found to increase the conductance of bilayer lipid membranes (BLMs) by inducing channel activity. The channels exhibited a distribution of conductances within the range of 10 to 380 pS, with the majority of the channels falling into two categories of conductance at 110 and 60 pS. The radii of beta-toxin pores found for the conductance states of 110 and 60 pS were 12.7 and 11.1 Å, respectively. The single channels and the steady-state currents induced by beta-toxin across the BLMs exhibited ideal monovalent cation selectivity. Addition of divalent cations (Zn
2+
, Cd
2+
, or Mg
2+
) at a concentration of 2 mM increased the rate of beta-toxin insertion into BLMs and the single-channel conductance, while application of 5 mM Zn
2+
to a beta-toxin-induced steady-state current decreased the inward current by approximately 45%. The mutation of arginine 212 of beta-toxin to aspartate, previously shown to increase the 50% lethal dose of beta-toxin for mice nearly 13-fold, significantly reduced the ability of beta-toxin to form channels. These data support the hypothesis that the lethal action of beta-toxin is based on the formation of cation-selective pores in susceptible cells.
Salmonella entericaSerovar Typhimurium-Dependent Regulation of Inducible Nitric Oxide Synthase Expression in Macrophages by Invasins SipB, SipC, and SipD and Effector SopE2
Authors: Cherayil Bobby J. , McCormick Beth A. , Bosley Jacob 
Published: July 2002

ABSTRACTWhenSalmonella entericainvades mammalian cells, it activates signals leading to increased expression of inflammatory mediators. One such mediator is nitric oxide (NO), which is produced under control of the enzyme inducible NO synthase (iNOS). Induction of iNOS in response toSalmonellainfection has been demonstrated, but the bacterial effector molecules that regulate expression of the enzyme have not been identified. In the study reported here, an analysis ofSalmonella-dependent iNOS expression in macrophages was carried out. Wild-typeSalmonellastrains increased the levels of both iNOS protein and mRNA in murine macrophage cell lines in an invasion-independent fashion. Mutant strains lacking a functional pathogenicity island 1-encoded type III secretion system, as well as strains lacking the invasins SipB, SipC, and SipD, were impaired in iNOS induction. Complementation experiments indicated that all three of the invasins were required for induction of iNOS expression. These results suggested that an effector protein, translocated into macrophages via the type III secretion system in a SipB-, SipC-, and SipD-dependent manner, might be the ultimate mediator of iNOS induction. In keeping with this idea, a mutant strain deficient in SopE2, a recently described homolog of SopE, was found to be impaired in the induction of iNOS expression. These observations suggest that iNOS expression is regulated by signals activated by SopE2 (and possibly SopE) and that the role of SipB, SipC, and SipD in this process is to facilitate translocation of the relevant effector.
Identification of Vaccine Candidates for Experimental Visceral Leishmaniasis by Immunization with Sequential Fractions of a cDNA Expression Library
Authors: Melby Peter C. , Ogden Gary B. , Flores Hector A. , Zhao Weiguo , Geldmacher Christopher , Biediger Natalie M. , Ahuja Sunil K. , Uranga Jose , Melendez Maria 
Published: July 2002

ABSTRACTVisceral leishmaniasis caused by the intracellular parasiteLeishmania donovaniis a significant public health problem in many regions of the world. Because of its large genome and complex biology, developing a vaccine for this pathogen has proved to be a challenging task and, to date, protective recombinant vaccine candidates have not been identified. To tackle this difficult problem, we adopted a reductionist approach with the intention of identifying cDNA sequences in anL. donovaniamastigote cDNA library that collectively or singly conferred protection against parasite challenge in a murine model of visceral leishmaniasis. We immunized BALB/c mice with plasmid DNA isolated and pooled from 15 cDNA sublibraries (∼2,000 cDNAs/sublibrary). Following systemic challenge withL. donovani, mice immunized with 6 of these 15 sublibraries showed a significantly reduced (35- to 1,000-fold) hepatic parasite burden. Because of the complexity and magnitude of the sequential fractionation-immunization-challenge approach, we restricted our attention to the two sublibraries that conferred the greatest in vivo protection. From one of these two sublibraries, we identified several groups of cDNAs that afforded protection, including a set of nine novel cDNAs and, surprisingly, a group of five cDNAs that encodedL. donovanihistone proteins. At each fractionation step, the cDNA sublibraries or the smaller DNA fractions that afforded in vivo protection against the parasite also induced in vitro parasite-specific T helper 1 immune responses. Our studies demonstrate that immunization with sequential fractions of a cDNA library is a powerful strategy for identifying anti-infective vaccine candidates.
Tumor Necrosis Factor Alpha p55 Receptor Is Important for Development of Memory Responses to Blood-Stage Malaria Infection
Authors: Li Ching , Langhorne Jean 
Published: July 2002

ABSTRACTTumor necrosis factor alpha (TNF-α) is associated with malarial pathology in both humans and mice. InPlasmodium chabaudi chabaudi(AS) infections, the production of TNF-α and reactive metabolites from macrophages are also thought to play a role in controlling acute parasitemia. Since many of the biological functions of TNF-α are effected through the p55 receptor (p55R), mice made defective in this receptor via a targeted gene disruption (p55R−/−) have been used to study its involvement in the immune response againstP. chabaudi chabaudiand in the pathology associated with this infection. In the absence of the p55R, mice could overcome their primary infection, although higher acute-blood-stage parasitemias and more significant recrudescences were observed. Hypoglycemia, hypothermia, loss of erythrocytes, and loss of body weight, which occur transiently in this infection, were exacerbated by the lack of the p55R, but the differences were small, suggesting that other factors affect these symptoms. In contrast to wild-type (WT) mice, a second challenge infection in p55R−/−mice resulted in a course of infection similar to a primary infection. The malaria-specific immunoglobulin G antibody response of p55R−/−mice was lower than that of WT mice and was not increased by the second challenge infection. These data suggest that p55R−/−mice do not develop an efficient memory B-cell response against malarial infection and that this antibody response is important in immunity to reinfection.
Cellular and Cytokine Correlates of Mucosal Protection in Murine Model of Oral Candidiasis
Authors: Elahi Shokrollah , Pang Gerald , Clancy Robert , Ashman Robert B. 
Published: July 2002

ABSTRACTHost protection againstCandida albicansinfection in a model of oral candidiasis involving infection-prone [DBA/2 (H-2d)] and less infection-prone [BALB/c (H-2d)] mouse strains was analyzed in terms of antibody and cellular responses, and in terms of cytokine patterns from regional lymph node cells. There was a selective expansion of γ/δ+T-cell receptor cells, which correlated with the patterns of colonization in both mouse strains, with higher numbers of γ/δ T cells detected in BALB/c mice. Antigen-induced T-cell proliferation was significantly higher in BALB/c mice than in DBA/2 mice. Higher levels of serum immunoglobulin G (IgG) and salivary IgA antibodies were detected in BALB/c mice than in DBA/2 mice, but only after the infection was cleared. The cervical lymph node cells from infected mice were assessed for interleukin-4 (IL-4), IL-12, and gamma interferon (IFN-γ) mRNA gene expression by reverse transcription-PCR and protein production in the culture supernatants following restimulation in vitro. In BALB/c mice, an early increase in levels of IL-4, IFN-γ, and IL-12 correlated with rapid elimination ofC. albicans. In DBA/2 mice, where resolution of infection was delayed, IL-4 message expression was delayed and the IL-4 secretion level was lower. Neutralization of IL-4 by multiple injections of an anti-IL-4 monoclonal antibody in BALB/c mice resulted in increased carriage rate and delayed clearance of the yeasts. Collectively, the data suggest that the T-cell response toC. albicansin the regional lymph nodes which correlates best with rapid oral clearance ofC. albicansis a balanced Th0 cytokine response involving early secretion of both IFN-γ and IL-4.
Integrated Genomic Map from Uropathogenic
Escherichia coli
J96
Authors: Melkerson-Watson Lyla J. , Rode Christopher K. , Zhang Lixin , Foxman Betsy , Bloch Craig A. 
Published: July 2002

ABSTRACT

Escherichia coli
J96 is a uropathogen having both broad similarities to and striking differences from nonpathogenic, laboratory
E. coli
K-12. Strain J96 contains three large (>100-kb) unique genomic segments integrated on the chromosome; two are recognized as pathogenicity islands containing urovirulence genes. Additionally, the strain possesses a fourth smaller accessory segment of 28 kb and two deletions relative to strain K-12. We report an integrated physical and genetic map of the 5,120-kb J96 genome. The chromosome contains 26
Not
I, 13
Bln
I, and 7 I-
Ceu
I macrorestriction sites. Macrorestriction mapping was rapidly accomplished by a novel transposon-based procedure: analysis of modified minitransposon insertions served to align the overlapping macrorestriction fragments generated by three different enzymes (each sharing a common cleavage site within the insert), thus integrating the three different digestion patterns and ordering the fragments. The resulting map, generated from a total of 54 mini-Tn
10
insertions, was supplemented with auxanography and Southern analysis to indicate the positions of insertionally disrupted aminosynthetic genes and cloned virulence genes, respectively. Thus, it contains not only physical, macrorestriction landmarks but also the loci for eight housekeeping genes shared with strain K-12 and eight acknowledged urovirulence genes; the latter confirmed clustering of virulence genes at the large unique accessory chromosomal segments. The 115-kb J96 plasmid was resolved by pulsed-field gel electrophoresis in
Not
I digests. However, because the plasmid lacks restriction sites for the enzymes
Bln
I and I-
Ceu
I, it was visualized in
Bln
I and I-
Ceu
I digests only of derivatives carrying plasmid inserts artificially introducing these sites. Owing to an I-
Sce
I site on the transposon, the plasmid could also be visualized and sized from plasmid insertion mutants after digestion with this enzyme. The insertional strains generated in construction of the integrated genomic map provide useful physical and genetic markers for further characterization of the J96 genome.
Maturation of Human Dendritic Cells by Cell Wall Skeleton ofMycobacterium bovisBacillus Calmette-Guérin: Involvement of Toll-Like Receptors
Authors: Tsuji Shoutaro , Matsumoto Misako , Takeuchi Osamu , Akira Shizuo , Azuma Ichiro , Hayashi Akira , Toyoshima Kumao , Seya Tsukasa 
Published: July 2002

ABSTRACTThe constituents of mycobacteria are an effective immune adjuvant, as observed with complete Freund's adjuvant. In this study, we demonstrated that the cell wall skeleton ofMycobacterium bovisbacillus Calmette-Guérin (BCG-CWS), a purified noninfectious material consisting of peptidoglycan, arabinogalactan, and mycolic acids, induces maturation of human dendritic cells (DC). Surface expression of CD40, CD80, CD83, and CD86 was increased by BCG-CWS on human immature DC, and the effect was similar to those of interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), heat-killed BCG, and viable BCG. BCG-CWS induced the secretion of TNF-α, IL-6, and IL-12 p40. CD83 expression was increased by a soluble factor secreted from BCG-CWS-treated DC and was completely inhibited by monoclonal antibodies against TNF-α. BCG-CWS-treated DC stimulated extensive allogeneic mixed lymphocyte reactions. The level of TNF-α secreted through BCG-CWS was partially suppressed in murine macrophages with no Toll-like receptor 2 (TLR 2) or TLR4 and was completely lost in TLR2 and TLR4 double-deficient macrophages. These results suggest that the BCG-CWS induces TNF-α secretion from DC via TLR2 and TLR4 and that the secreted TNF-α induces the maturation of DC per se.
Immunogenicity of the B Monomer ofEscherichia coliHeat-Labile Toxin Expressed on the Surface ofStreptococcus gordonii
Authors: Ricci Susanna , Medaglini Donata , Rush Catherine M. , Marcello Alessandro , Peppoloni Samuele , Manganelli Riccardo , Palú Giorgio , Pozzi Gianni 
Published: July 2002

ABSTRACTThe B monomer of theEscherichia coliheat-labile toxin (LTB) was expressed on the surface of the human oral commensal bacteriumStreptococcus gordonii. Recombinant bacteria expressing LTB were used to immunize BALB/c mice subcutaneously and intragastrically. The LTB monomer expressed on the streptococcal surface proved to be highly immunogenic, as LTB-specific immunoglobulin G (IgG) serum titers of 140,000 were induced after systemic immunization. Most significantly, these antibodies were capable of neutralizing the enterotoxin in a cell neutralization assay. Following mucosal delivery, antigen-specific IgA antibodies were found in feces and antigen-specific IgG antibodies were found in sera. Analysis of serum IgG subclasses showed a clear predominance of IgG1 when recombinant bacteria were inoculated subcutaneously, while a prevalence of IgG2a was observed upon intragastric delivery, suggesting, in this case, the recruitment of a Th1 type of immune response.