bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Six Immunoassays for Detection of Dengue Virus-Specific Immunoglobulin M and G Antibodies
Authors: Groen Jan , Koraka Penelopie , Velzing Jans , Copra Cedrick , Osterhaus Albert D. M. E. 
Published: July 2002

ABSTRACT
The performance of six commercially available immunoassay systems for the detection of dengue virus-specific immunoglobulin M (IgM) and IgG antibodies in serum was evaluated. These included two IgM and IgG enzyme immunoassays (EIA) from MRL Laboratories and PanBio, a rapid immunochromatographic test (RIT) from PanBio, immunofluorescence assays (IFA) from Progen, a dot blot assay from Genelabs, and a dipstick EIA from Integrated Diagnostics (INDX). For this study a panel of 132 serum samples, including 90 serum samples from patients with suspected dengue virus infection and 42 serum samples from patients with other viral infections, was used. In addition, serial serum samples from two monkeys experimentally immunized and challenged with dengue virus type 2 were used. Results were considered conclusive when concordant results were obtained with four of the six antibody-specific assays. Based on this definition, the calculated overall agreement for the human serum samples for the respective IgM immunoassays was 97% (128 of 132), with 34% (45 of 132) positive serum samples, 63% (83 of 132) negative samples, and 3% of samples (4 of 132) showing discordant results. The calculated overall agreement for the IgG assays was 94% (124 of 132), with 49% (65 of 132) positive, 45% (59 of 132) negative, and 6% (8 of 132) discordant results, respectively. The sensitivities of the dengue virus-specific assays evaluated varied between 71 and 100% for IgM and between 52 and 100% for IgG, with specificities of 86 to 96% and 81 to 100%, respectively. The relative sensitivities of the respective IgM assays measured with the monkey serum samples were comparable with those obtained with 12 serial serum samples from humans. Overall performance, based on the sum of the agreement, sensitivity, specificity, and Kappa statistics of the IgM and IgG immunoassays, showed that the antibody detection systems from INDX and Genelabs and the MRL and PanBio EIA are useful and reliable assays for dengue virus serodiagnosis.
Simple and Rapid Method for Production of Whole-Virus Antigen for Serodiagnosis of Caprine Arthritis-Encephalitis Virus by Enzyme-Linked Immunosorbent Assay
Authors: Simard Carole , Kibenge Molly Twinomwe , Singh Patricia , Dixon Phyllis 
Published: July 2002

ABSTRACTPolyethylene glycol (PEG) was used to produce whole-virus antigen derived from tissue culture cells infected with a Canadian strain of caprine arthritis-encephalitis virus. PEG antigen batches were obtained after precipitation and concentration of infected tissue culture material with PEG 8000 and final treatment with sodium dodecyl sulfate. The optimum time of harvest of tissue culture extracted material to produce the maximum amount of viral proteins was determined in roller bottles, after cocultivation of infected and noninfected fetal lamb corneal cells. Samples from day 9 to day 25 postculture were collected and processed. By Western blotting, the optimum time of harvest was found to be day 25 following the coculture. Two large batches of PEG antigen were prepared at the optimum time of harvest. Both batches gave similar results when tested by Western blotting and enzyme-linked immunosorbent assay (ELISA), using reference control sera from infected and noninfected goats. For further testing in ELISA, cutoff values and ratios were determined for PEG batch 1, using 200 known serum samples from goats free of the disease. The PEG antigen batch was compared with an in-house ELISA antigen in a kinetic mode, using 498 serum samples from field goats. The in-house ELISA antigen was produced following two rounds of ultracentrifugation and treatment with sodium dodecyl sulfate (R. A. Heckert, W. B. McNab, S. M. Richardson, and M. R. Briscoe, Can. J. Vet. Res. 56:237–241, 1992). The PEG antigen batch was found suitable for ELISA, with a relative specificity of 100% and a relative sensitivity of 99.4% compared to the in-house ELISA antigen. This method of antigen production for ELISA was found to be rapid, inexpensive, and reliable for the diagnosis of caprine-arthritis encephalitis, without requiring the use of sophisticated laboratory equipment.
Enzyme Immunoassay Detection of Antigen-Specific Immunoglobulin G Antibodies in Longitudinal Serum Samples from Patients with Cryptosporidiosis
Authors: Priest Jeffrey W. , Li Anna , Khan Mohamad , Arrowood Michael J. , Lammie Patrick J. , Ong Corinne S. , Roberts Jacquelin M. , Isaac-Renton Judith 
Published: July 2002

ABSTRACT

Cryptosporidium parvum
is a protozoan parasite that causes diarrheal illness in a wide range of mammalian hosts, including humans. Characteristic serum immunoglobulin G (IgG) antibody responses to antigens in the 27- and 17-kDa size ranges have been shown to develop after infection, and several enzyme-linked immunosorbent assay (ELISA) and Western blot assay formats have been used to measure these IgG levels in human serum. Using a collection of serial samples from laboratory-confirmed cryptosporidiosis patients, we compared the results obtained by using two new ELISAs with those obtained with two different Western blot assays. When assayed with the large-format Western blot, 97% of the 67 patients had a demonstrable antibody response on at least one occasion. The Cp23 ELISA correctly identified 93% of the samples that had a 27-kDa response by Western blot and 100% of the negative samples. The Triton antigen ELISA detected 77% of the samples that had a 17-kDa response by Western blot and 88% of the negative samples. The sensitivity of the Triton antigen assay was higher for samples collected between 16 and 92 days after the onset of symptoms (96%). The minigel-format Western blot did not compare favorably with the large-format blot for the detection of antibodies to the 27-kDa antigen (71% sensitivity). A half-life of about 12 weeks was estimated for antibodies to both the 27- and 17-kDa antigens. We believe the Cp23 and Triton antigen ELISAs will be useful in epidemiologic studies of the prevalence of
Cryptosporidium
infection in the population.
Detection of Antibodies to
Babesia equi
in Horses by a Latex Agglutination Test Using Recombinant EMA-1
Authors: Xuan Xuenan , Igarashi Ikuo , Tanaka Tetsuya , Fukumoto Shinya , Nagasawa Hideyuki , Fujisaki Kozo , Mikami Takeshi 
Published: July 2002

ABSTRACT

A latex agglutination test (LAT) using recombinant equi merozoite antigen 1 (EMA-1) for the detection of antibodies to
Babesia equi
was developed. The LAT was able to differentiate very clearly between sera from
B. equi
-infected horses and sera from
Babesia caballi
-infected horses or from normal horses. The LAT results were identical to those of a previously developed enzyme-linked immunosorbent assay. These results indicate that LAT using recombinant EMA-1 might be very useful as a routine screening method for the diagnosis of
B. equi
infection.
Serum Immunoglobulin G Antibody Responses to
Bordetella pertussis
Lipooligosaccharide and
B.
parapertussis
Lipopolysaccharide in Children with Pertussis and Parapertussis
Authors: Trollfors Birger , Lagergård Teresa , Taranger John , Bergfors Elisabet , Schneerson Rachel , Robbins John B. 
Published: July 2002

ABSTRACT

Serum immunoglobulin G (IgG) antibodies against the lipooligosaccharide (LOS) of
Bordetella pertussis
and the lipopolysaccharide (LPS) of
Bordetella parapertussis
were measured by enzyme-linked immunosorbent assay in paired sera from 40 children with pertussis and 14 with parapertussis. Wide differences in the individual responses were noted. Both anti-LOS and -LPS IgG levels increased significantly in the children with pertussis, as did anti-LPS but not anti-LOS in those with parapertussis.
Detection of Y Chromosome DNA as Evidence of Semen in Cervicovaginal Secretions of Sexually Active Women
Authors: Chomont Nicolas , Grésenguet Gérard , Lévy Michel , Hocini Hakim , Becquart Pierre , Matta Mathieu , Tranchot-Diallo Juliette , Andreoletti Laurent , Carreno Marie-Paule , Kazatchkine Michel D. , Bélec Laurent 
Published: July 2002

ABSTRACT
The detection of traces of semen in cervicovaginal secretions (CVS) from sexually active women practicing unprotected sex is a prerequisite for the accurate study of cervicovaginal immunity. Two semen markers, the prostatic-specific antigen (PSA) and the Y chromosome, were detected in parallel in CVS obtained by a standardized vaginal washing of consecutive women attending the principal medical center for sexually transmitted diseases of Bangui, Central African Republic. PSA was detected by immunoenzymatic capture assay in the cell-free fraction of CVS, and the Y chromosome was detected by a single PCR assay of DNA extracted by silica from the cell fraction (Y PCR). Fifty (19%) cell-free fractions of the 264 β-globin-positive CVS samples were positive for PSA, and 100 (38%) cell fractions of the CVS samples were positive for the Y chromosome. All the 50 (19%) PSA-containing CVS samples were also positive for the Y chromosome. Fifty (19%) CVS samples were positive only for the Y chromosome, with no detectable PSA. The remaining 164 (62%) CVS samples were both PSA and Y chromosome negative. These findings demonstrate that CVS from sexually active women may contain cell-associated semen residues unrecognized by conventional immunoenzymatic assays used to detect semen components. The detection of cell-associated male DNA with a highly sensitive and specific procedure such as Y PCR constitutes a method of choice to detect semen traces in female genital secretions.
Diagnosis ofHelicobacter pyloriInfection in Children: Comparison of a Salivary Immunoglobulin G Antibody Test with the [13C]Urea Breath Test
Authors: Bode G. , Marchildon P. , Peacock J. , Brenner H. , Rothenbacher D. 
Published: July 2002

ABSTRACTThe prevalence ofHelicobacter pyloriinfection in a population-based sample of 477 children (mean age ± standard deviation, 5.8 ± 0.5 years) determined by the [13C]urea breath test ([13C]UBT) was 10.7% (95% confidence interval [CI], 8.1 to 13.8%), and that determined by salivary enzyme-linked immunosorbent assay (ELISA) was 11.9% (95% CI, 9.2 to 15.2%). Compared to the [13C]UBT, the sensitivity and specificity of the salivary ELISA were 80.9% (95% CI, 66.3 to 90.4%) and 95.3% (95% CI, 92.7 to 97.1%), respectively.
One-Step PCR To Distinguish B Virus from Related Primate Alphaherpesviruses
Authors: Hirano Makoto , Nakamura Shin , Mitsunaga Fusako , Okada Maki , Shirahama Shuya , Eberle Richard 
Published: July 2002

ABSTRACTBy adding betaine to the PCR mixture, we previously established a PCR method to amplify a DNA segment of the glycoprotein G gene of B virus (BV) derived from a rhesus macaque. We have found that DNA of other BV strains derived from cynomolgus, pigtail, and lion-tailed macaques can also serve as the template in our PCR assay. Under the same conditions no product was obtained with DNA of simian agent 8 of green monkeys andHerpesvirus papio2 of baboons, or the human herpes simplex viruses types 1 and 2. Thus, this PCR method is useful to discriminate BV from other closely related primate alphaherpesviruses.
Whipple's Disease and “Tropheryma whippelii”
Authors: Dutly Fabrizio , Altwegg Martin 
Published: July 2002

SUMMARYWhipple's disease is a rare bacterial infection that may involve any organ system in the body. It occurs primarily in Caucasian males older than 40 years. The gastrointestinal tract is the most frequently involved organ, with manifestations such as abdominal pain, malabsorption syndrome with diarrhea, and weight loss. Other signs include low-grade fever, lymphadenopathy, skin hyperpigmentation, endocarditis, pleuritis, seronegative arthritis, uveitis, spondylodiscitis, and neurological manifestations, and these signs may occur in the absence of gastrointestinal manifestations. Due to the wide variability of manifestations, clinical diagnosis is very difficult and is often made only years or even decades after the initial symptoms have appeared. Trimethoprim-sulfamethoxazole for at least 1 year is usually considered adequate to eradicate the infection. The microbiological diagnosis of this insidious disease is rendered difficult by the virtual lack of culture and serodiagnostic methods. It is usually based on the demonstration of periodic acid-Schiff-positive particles in infected tissues and/or the presence of bacteria with an unusual trilaminar cell wall ultrastructure by electron microscopy. Recently, the Whipple bacteria have been characterized at the molecular level by amplification of their 16S rRNA gene(s). Phylogenetic analysis of these sequences revealed a new bacterial species related to the actinomycete branch which was named “Tropheryma whippelli.” Based on its unique 16S ribosomal DNA (rDNA) sequence, species-specific primers were selected for the detection of the organism in clinical specimens by PCR. This technique is currently used as one of the standard methods for establishing the diagnosis of Whipple's disease. Specific and broad-spectrum PCR amplifications mainly but not exclusively from extraintestinal specimens have significantly improved diagnosis, being more sensitive than histopathologic analysis. However, “T. whippelii” DNA has also been found in persons without clinical and histological evidence of Whipple's disease. It is unclear whether these patients are true asymptomatic carriers or whether differences in virulence exist among strains of “T. whippelii” that might account for the variable clinical manifestations. So far, six different “T. whippelii” subtypes have been found by analysis of their 16S-23S rDNA spacer region. Further studies of the pathogen “T. whippelii” as well as the host immune response are needed to fully understand this fascinating disease. The recent cultivation of the organisms is a promising major step in this direction.
Dracunculiasis (Guinea Worm Disease) and the Eradication Initiative
Authors: Cairncross Sandy , Muller Ralph , Zagaria Nevio 
Published: July 2002

SUMMARYDracunculiasis, also known as guinea worm disease, is caused by the large female of the nematode Dracunculus medinensis, which emerges painfully and slowly from the skin, usually on the lower limbs. The disease can infect animals, and sustainable animal cycles occur in North America and Central Asia but do not act as reservoirs of human infection. The disease is endemic across the Sahel belt of Africa from Mauritania to Ethiopia, having been eliminated from Asia and some African countries. It has a significant socioeconomic impact because of the temporary disability that it causes. Dracunculiasis is exclusively caught from drinking water, usually from ponds. A campaign to eradicate the disease was launched in the 1980s and has made significant progress. The strategy of the campaign is discussed, including water supply, health education, case management, and vector control. Current issues including the integration of the campaign into primary health care and the mapping of cases by using geographic information systems are also considered. Finally, some lessons for other disease control and eradication programs are outlined.
Production of Borreliacidal Antibody to Outer Surface Protein A In Vitro and Modulation by Interleukin-4
Authors: Munson Erik L. , Du Chateau Brian K. , Jobe Dean A. , Lovrich Steven D. , Callister Steven M. , Schell Ronald F. 
Published: July 2002

ABSTRACTBorreliacidal antibody production is one of several parameters for establishing the effectiveness ofBorrelia burgdorferivaccines. The production of borreliacidal antibody was studied in vitro by culturing immune lymph node cells with macrophages andB. burgdorferi. We showed that borreliacidal antibody, directed primarily against outer surface protein A (OspA), was readily produced by lymph node cells obtained from C3H/HeJ mice vaccinated with formalin-inactivatedB. burgdorferiin aluminum hydroxide, but not recombinant OspA. Anti-OspA borreliacidal antibody was detected in supernatants of cultures of lymph node cells obtained on day 7 after vaccination, peaked on day 17, and rapidly declined. The borreliacidal activity was attributable to immunoglobulin G1 (IgG1), IgG2a, and IgG2b antibodies. When lymph node cells were treated with interleukin-4 (IL-4), production of borreliacidal antibody was inhibited but was unaffected by treatment with anti-IL-4 antibodies. These results suggest that other cytokines, but not IL-4, are mainly responsible for production of the secondary borreliacidal antibody response.
Immunization with RecombinantPlasmodium yoeliiMerozoite Surface Protein 4/5 Protects Mice against Lethal Challenge
Authors: Kedzierski Lukasz , Black Casilda G. , Coppel Ross L. 
Published: July 2002

ABSTRACTPlasmodium yoeliimerozoite surface protein 4/5 (PyMSP4/5), expressed as a recombinant protein, was highly effective at protecting mice against lethal challenge withP. yoelii. There was a significant correlation between prechallenge antibody levels and peak parasitemia, suggesting that the homologues of PyMSP4/5 inPlasmodium falciparumare promising components of a subunit vaccine against malaria.
Released ATP Is an Extracellular Cytotoxic Mediator in Salivary Histatin 5-Induced Killing of
Candida albicans
Authors: Koshlukova Svetlana E. , Araujo Marcelo W. B. , Baev Didi , Edgerton Mira 
Published: July 2002

ABSTRACT

Salivary histatins (Hsts) are antifungal peptides with promise as therapeutic agents against candidiasis. Hst 5 kills the fungal pathogen
Candida albicans
via a mechanism that involves release of cellular ATP in the absence of cytolysis. Here we demonstrate that released ATP has a further role in Hst 5 killing. Incubation of the cells with ATP analogues induced cell death, and addition of the ATP scavenger apyrase to remove extracellular ATP released during Hst 5 treatment resulted in a reduction in cell killing. Experiments using anaerobically grown
C. albicans
with decreased susceptibility to Hst 5 confirmed that depletion of cellular ATP as a result of ATP efflux was not sufficient to cause cell death. In contrast to Hst-susceptible aerobic cultures, anaerobically grown cells were not killed by exogenously applied ATP. These findings established that Hst binding, subsequent entry into the cells, and ATP release precede the signal for cytotoxicity, which is mediated by extracellular ATP. In a higher-eukaryote paradigm, released ATP acts as a cytotoxic mediator by binding to membrane nucleotide P2X receptors. Based on a pharmacological profile and detection of a
C. albicans
60-kDa membrane protein immunoreactive with antibody to P2X
7
receptor, we propose that released ATP in response to Hst 5 activates candidal P2X
7
-like receptors to cause cell death.
DNA Rearrangements in the Flagellin Locus of an
flaA
Mutant of
Campylobacter jejuni
during Colonization of Chicken Ceca
Authors: Nuijten Piet J. M. , van den Berg Anton J. G. , Formentini Ivan , van der Zeijst Bernard A. M. , Jacobs Anton A. C. 
Published: July 2002

ABSTRACT

Campylobacter jejuni
is an enteropathogen for humans but commensal for chickens. In both hosts, the flagella and motility are important colonization factors. The flagellin gene is duplicated in
Campylobacter
, but only one flagellin gene,
flaA
, is sufficient for motility. We found that, during colonization of the chicken intestine, a nonmotile
flaA
mutant of
C. jejuni
underwent rearrangements within its flagellin locus, thereby regaining its motility and colonization capacity. In contrast, in vitro motile revertants isolated from liquid culture showed different flagellin DNA rearrangements than after reversion in the chicken.
Cloning and Characterization ofvuuA, a Gene Encoding theVibrio vulnificusFerric Vulnibactin Receptor
Authors: Webster Athena C. D. , Litwin Christine M. 
Published: July 2002

ABSTRACTThe ability ofVibrio vulnificusto acquire iron from the host has been shown to correlate with virulence. Many iron transport genes are regulated by iron, and inV. vulnificus, transcriptional regulation by iron depends on thefurgene. The N-terminal amino acid sequence of a 72-kDa iron-regulated outer membrane protein purified from aV. vulnificus furmutant had 53% homology with the first 15 amino acids of the mature protein of theVibrio choleraevibriobactin receptor, ViuA. In this report, we describe the cloning, DNA sequence, mutagenesis, and analysis of transcriptional regulation of the structural gene for VuuA, the vulnibactin receptor ofV. vulnificus. Analysis of the DNA sequence of thevuuApromoter region demonstrated a sequence identical to the upstream Fur box ofV. cholerae viuA. Northern blot analysis showed that the transcript was strongly regulated by iron. The amino acid sequence of VuuA was 74% identical to the sequence ofV. choleraeViuA and was homologous to those of several TonB-dependent outer membrane receptors. An internal deletion of theV. vulnificus vuuAgene resulted in the loss of expression of the 72-kDa protein and the loss of the ability to use transferrin or vulnibactin as a source of iron. This mutant showed reduced virulence in an infant mouse model. Introduction of a plasmid containing the completeviuAcoding sequence and 342 bp of upstream DNA into the mutant restored ferric vulnibactin and ferric transferrin utilization to the mutant.
Biochemical and Immunological Characterization of MP65, a Major Mannoprotein Antigen of the Opportunistic Human Pathogen
Candida albicans
Authors: Gomez Maria J. , Maras Bruno , Barca Alessandra , La Valle Roberto , Barra Donatella , Cassone Antonio 
Published: July 2002

ABSTRACT

In the search of the antigenic determinants of a 65-kDa mannoprotein (MP65) of
Candida albicans
, tryptic fragments of immunoaffinity-purified MP65 preparations were tested for their ability to induce lymphoproliferation of human peripheral blood mononuclear cells (PBMC). Five major peptides (T1 to T5) were shown to induce a vigorous proliferation of PBMC from the majority of the eight healthy human subjects tested. With the use of synthetic peptides, critical amino acid sequences of the two most immunoactive (T1 and T2) peptides were determined. Similar to what was found for the MP65 molecule, no PBMC multiplication was induced by the antigenic peptides in cultures of naive cord blood cells. The amino acid sequence analysis of tryptic and chymotryptic peptides of MP65 demonstrated a substantial homology with the deduced sequences of two cell wall proteins of
Saccharomyces cerevisiae
, encoded by the genes
YRM305C
and
YGR279C
. However, the antigenic peptides were those showing the least similarity with the corresponding regions of the above proteins. In particular, the lymphoproliferation-inducing sequence of the T1 peptide scored only 20% identity with the homologous regions of
S. cerevisiae
proteins. Besides disclosing the amino acid sequence of MP65, this study provides an initial characterization of some of its antigenic determinants, as well as of synthetic peptides of potential use to detect specific immune responses against MP65, a major target of anticandidal cell-mediated immunity in humans.