bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnosis of Visceral Leishmaniasis by Enzyme-Linked Immunosorbent Assay Using Urine Samples
Authors: Islam Mohammad Zahidul , Itoh Makoto , Shamsuzzaman S. M. , Mirza Rusella , Matin Farzana , Ahmed Iftikhar , Shamsuzzaman Choudhury A. K. M. , Hossain M. Akram , Qiu Xu-Guang , Begam Nilufar , Furuya Masato , Leafasia Judson L. , Hashiguchi Yoshihisa , Kimura Eisaku 
Published: July 2002

ABSTRACT

A diagnostic method has been developed to detect anti-
Leishmania donovani
immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-
L. donovani
IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using
L. donovani
promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated
L. donovani
promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of
L. donovani
crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-
L. donovani
IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-
L. donovani
IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.
Genetic Heterogeneity of Small Ruminant Lentiviruses Involves Immunodominant Epitope of Capsid Antigen and Affects Sensitivity of Single-Strain-Based Immunoassay
Authors: Grego Elena , Profiti Margherita , Giammarioli Monica , Giannino Laura , Rutili Domenico , Woodall Chris , Rosati Sergio 
Published: July 2002

ABSTRACT

The
pol
and
gag
gene fragments of small ruminant lentivirus field isolates collected in the last decade in Italy were amplified, sequenced, and analyzed. Phylogenetic analysis revealed that the majority of ovine isolates form a distinct cluster more similar to caprine lentivirus prototypes than to the visna virus prototype. These findings confirm and extend those reported by Leroux et al. (Arch. Virol., 142:1125-1137, 1997). Moreover, we observed that a variable region of Gag, included in the fragment analyzed, corresponded to one of the three major capsid antigen epitopes, which suggests that the antibody response to this epitope may be type specific. To test this hypothesis, two recombinant peptides, derived from the Icelandic prototype K1514 and this novel genotype, were expressed and used in an enzyme-linked immunosorbent assay to screen a panel of ovine and caprine sera collected from different geographical locations in Italy. Several sera reacted in a type-specific manner, indicating that in a diagnostic setting the combination of at least these two type-specific peptides is necessary to cover a wide range of infections. Additionally, these results support the hypothesis of cross-species transmission based on the phylogenetic analysis described above. This has implications for the control and eradication of small ruminant lentivirus infections.
Identification, Molecular Cloning, and Evaluation of Potential Use of Isocitrate Dehydrogenase II of
Mycobacterium bovis
BCG in Serodiagnosis of Tuberculosis
Authors: Florio W. , Bottai D. , Batoni G. , Esin S. , Pardini M. , Maisetta G. , Campa M. 
Published: July 2002

ABSTRACT

Diagnosis of tuberculosis is time-consuming and requires infrastructures which are often not available in countries with high incidences of the disease. In the present study, an 82-kDa protein antigen was isolated by affinity chromatography and was identified by peptide mass fingerprinting as isocitrate dehydrogenase II, which is encoded by the
icd2
gene of
Mycobacterium bovis
BCG. The
icd2
gene of BCG was cloned by PCR, and the product of recombinant gene expression was purified and analyzed by two-dimensional polyacrylamide gel electrophoresis. The recombinant protein, named rICD2, was tested for its recognition by immunoglobulin G (IgG) antibodies from the sera of 16 patients with tuberculosis (TB) and 23 healthy individuals by Western blotting. The results showed that rICD2 is recognized by IgG antibodies from the sera of all TB patients tested at serum dilutions of ≥1:640. At a serum dilution of 1:1,280, the sensitivity was 50% and the specificity was 86.9%. These results indicate that rICD2 might represent a candidate for use in a new assay for the serodiagnosis of TB.
Use of Multiepitope Polyproteins in Serodiagnosis of Active Tuberculosis
Authors: Houghton Raymond L. , Lodes Michael J. , Dillon Davin C. , Reynolds Lisa D. , Day Craig H. , McNeill Patricia D. , Hendrickson Ronald C. , Skeiky Yasir A. W. , Sampaio Diana P. , Badaro Roberto , Lyashchenko Konstantin P. , Reed Steven G. 
Published: July 2002

ABSTRACTScreening of genomic expression libraries fromMycobacterium tuberculosiswith sera from tuberculosis (TB) patients or rabbit antiserum toM. tuberculosisled to the identification of novel antigens capable of detecting specific antibodies toM. tuberculosis. Three antigens, Mtb11 (also known as CFP-10), Mtb8, and Mtb48, were tested together with the previously reported 38-kDa protein, in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies in TB patients. These four proteins were also produced as a genetically fused polyprotein, which was tested with two additional antigens, DPEP (also known as MPT32) and Mtb81. Sera from individuals with pulmonary and extrapulmonary TB, human immunodeficiency virus (HIV)-TB coinfections, and purified protein derivative (PPD)-positive and PPD-negative status with no evidence of disease were tested. In samples from HIV-negative individuals, the ELISA detected antibodies in >80% of smear-positive individuals and >60% smear-negative individuals, with a specificity of ∼98%. For this group, smears detected 81.6% but a combination of smear and ELISA had a sensitivity of ∼93%. The antigen combination detected a significant number of HIV-TB coinfections as well as antibodies in patients with extrapulmonary infections. Improved reactivity in the HIV-TB group was observed by including the antigen Mtb81 that was identified by proteomics. The data indicate that the use of multiple antigens, some of which are in a single polyprotein, can be used to facilitate the development of a highly sensitive test forM. tuberculosisantibody detection.
Spectrum of Kaposi's Sarcoma-Associated Herpesvirus, or Human Herpesvirus 8, Diseases
Authors: Ablashi Dharam V. , Chatlynne Louise G. , Whitman, James E. , Cesarman Ethel 
Published: July 2002

SUMMARYHuman herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), discovered in 1994, is a human rhadinovirus (gamma-2 herpesvirus). Unlike other human herpesviruses (herpes simplex virus, Epstein-Barr virus, varicella-zoster virus, cytomegalovirus, HHV-6, and HHV-7), it is not widespread in the general population and has many unique proteins. HHV-8 is strongly associated with all subtypes of Kaposi's sarcoma (KS), multicentric Castleman's disease, and a rare form of B-cell lymphoma, primary effusion lymphoma. In addition, HHV-8 DNA sequences have been found in association with other diseases, but the role of the virus in these diseases is largely unconfirmed and remains controversial. The seroprevalence of HHV-8, based on detection of latent and lytic proteins, is 2 to 5% in healthy donors except in certain geographic areas where the virus is endemic, 80 to 95% in classic KS patients, and 40 to 50% in HIV-1 patients without KS. This virus can be transmitted both sexually and through body fluids (e.g., saliva and blood). HHV-8 is a transforming virus, as evidenced by its presence in human malignancies, by the in vitro transforming properties of several of its viral genes, and by its ability to transform some primary cells in culture. It is not, however, sufficient for transformation, and other cofactors such as immunosuppressive cytokines are involved in the development of HHV-8-associated malignancies. In this article, we review the biology, molecular virology, epidemiology, transmission, detection methods, pathogenesis, and antiviral therapy of this newly discovered human herpesvirus.
Legionella
and Legionnaires' Disease: 25 Years of Investigation
Authors: Fields Barry S. , Benson Robert F. , Besser Richard E. 
Published: July 2002

SUMMARY

There is still a low level of clinical awareness regarding Legionnaires' disease 25 years after it was first detected. The causative agents, legionellae, are freshwater bacteria with a fascinating ecology. These bacteria are intracellular pathogens of freshwater protozoa and utilize a similar mechanism to infect human phagocytic cells. There have been major advances in delineating the pathogenesis of legionellae through the identification of genes which allow the organism to bypass the endocytic pathways of both protozoan and human cells. Other bacteria that may share this novel infectious process are
Coxiella burnetti
and
Brucella
spp. More than 40 species and numerous serogroups of legionellae have been identified. Most diagnostic tests are directed at the species that causes most of the reported human cases of legionellosis,
L. pneumophila
serogroup 1. For this reason, information on the incidence of human respiratory disease attributable to other species and serogroups of legionellae is lacking. Improvements in diagnostic tests such as the urine antigen assay have inadvertently caused a decrease in the use of culture to detect infection, resulting in incomplete surveillance for legionellosis. Large, focal outbreaks of Legionnaires' disease continue to occur worldwide, and there is a critical need for surveillance for travel-related legionellosis in the United States. There is optimism that newly developed guidelines and water treatment practices can greatly reduce the incidence of this preventable illness.
Up-Regulation of Fas (CD95) and Induction of Apoptosis in Intestinal Epithelial Cells by Nematode
-
Derived Molecules
Authors: Kuroda Akio , Uchikawa Ryuichi , Matsuda Shinji , Yamada Minoru , Tegoshi Tatsuya , Arizono Naoki 
Published: July 2002

ABSTRACT

Infection by the intestinal nematode
Nippostrongylus brasiliensis
induces acceleration of apoptosis in the small intestinal villus epithelial cells in vivo. In the present study, we examined whether worm extract or excretory-secretory product induces apoptosis in the rat intestinal epithelial cell line IEC-6 in vitro. In the presence of worm extract or excretory-secretory product (≥6 μg/ml), IEC-6 cell growth was significantly suppressed, and there was a concomitant increase in the number of detached cells in culture dishes. Detached cells showed nuclear fragmentation, activation of caspase-3, and specific cleavage of poly(ADP-ribose) polymerase, suggesting that apoptosis was induced in these cells. Semiquantitative reverse transcription-PCR showed that expression of Fas (CD95) mRNA was up-regulated as early as 6 h after addition of excretory-secretory product, while Fas ligand expression and p53 expression were not up-regulated. Fluorescence-activated cell sorter analyses revealed a significant increase in Fas expression and a slight increase in FasL expression in IEC-6 cells cultured in the presence of excretory-secretory product, while control IEC-6 cells expressed neither Fas or FasL. These results indicated that
N. brasiliensis
worms produce and secrete biologically active molecules that trigger apoptosis in intestinal epithelial cells together with up-regulation of Fas expression, although the mechanism of induction of apoptosis remains to be elucidated.
LuxS-Mediated Quorum Sensing inBorrelia burgdorferi, the Lyme Disease Spirochete
Authors: Stevenson Brian , Babb Kelly 
Published: July 2002

ABSTRACTThe establishment ofBorrelia burgdorferiinfection involves numerous interactions between the bacteria and a variety of vertebrate host and arthropod vector tissues. This complex process requires regulated synthesis of many bacterial proteins. We now demonstrate that these spirochetes utilize a LuxS/autoinducer-2 (AI-2)-based quorum-sensing mechanism to regulate protein expression, the first system of cell-cell communication to be described in a spirochete. TheluxSgene ofB. burgdorferiwas identified and demonstrated to encode a functional enzyme by complementation of anEscherichia coli luxSmutant. CulturedB. burgdorferiresponded to AI-2 by altering the expression levels of a large number of proteins, including the complement regulator factor H-binding Erp proteins. Through this mechanism, a population of Lyme disease spirochetes may synchronize production of specific proteins needed for infection processes.
Plasma Membrane Cholesterol Modulates Cellular Vacuolation Induced by the
Helicobacter pylori
Vacuolating Cytotoxin
Authors: Patel Hetal K. , Willhite David C. , Patel Rakhi M. , Ye Dan , Williams Christopher L. , Torres Eric M. , Marty Kent B. , MacDonald Robert A. , Blanke Steven R. 
Published: July 2002

ABSTRACT

The
Helicobacter pylori
vacuolating cytotoxin (VacA) induces the degenerative vacuolation of mammalian cells both in vitro and in vivo. Here, we demonstrate that plasma membrane cholesterol is essential for vacuolation of mammalian cells by VacA. Vacuole biogenesis in multiple cell lines was completely blocked when cholesterol was extracted selectively from the plasma membrane by using β-cyclodextrins. Moreover, increasing plasma membrane cholesterol levels strongly potentiated VacA-induced vacuolation. In contrast, inhibiting de novo biosynthesis of cholesterol with lovastatin or compactin had no detectable effect on vacuolation. While depletion of plasma membrane cholesterol has been shown to interfere with both clathrin-mediated endocytosis and caveola-dependent endocytosis, neither of these two internalization pathways was found to be essential for vacuolation of cells by VacA. Depleting plasma membrane cholesterol attenuated the entry of VacA into HeLa cells. In addition, β-cyclodextrin reagents blocked vacuolation of cells that were either preloaded with VacA or had VacA directly expressed within the cytosol. Collectively, our results suggest that plasma membrane cholesterol is important for both the intoxication mechanism of VacA and subsequent vacuole biogenesis.
Generation and Characterization of Human Monoclonal scFv Antibodies against
Helicobacter pylori
Antigens
Authors: Reiche Nicole , Jung Andreas , Brabletz Thomas , Vater Tanja , Kirchner Thomas , Faller Gerhard 
Published: July 2002

ABSTRACT

Infection with
Helicobacter pylori
is chronic despite a vigorous cellular and humoral immune response and causes severe pathology in some patients. In this study, phage display was used as a new approach in order to investigate the role of the host's humoral immune response in the pathogenesis of
H. pylori
gastritis. Human monoclonal single-chain Fv (scFv) antibody fragments against
H. pylori
cell lysate and the
H. pylori
urease were isolated from an immune phage display library, constructed from peripheral blood lymphocytes of an
H. pylori
-infected patient. After affinity selection, 23% of the clones tested showed binding activity against a lysate of the
H. pylori
Sydney strain in enzyme-linked immunosorbent assay (ELISA) and 9% bound the
H. pylori
urease. Further characterization by PCR-fingerprint analysis and sequencing revealed that two closely related
H. pylori
binders and one antiurease scFv could be isolated. The selected scFvs were highly specific as analyzed by ELISA and immunoblots using various bacterial lysates and recombinant proteins. Analysis of the humoral immune response following
H. pylori
infection using human monoclonal antibodies might contribute to a better understanding of the pathogenesis of the disease. Moreover, using immune phage display libraries, it might be possible for relevant epitopes of
H. pylori
antigens to be determined, which might be of use for vaccine development.
Role of Yops and Adhesins in Resistance ofYersinia enterocoliticato Phagocytosis
Authors: Grosdent Nadine , Maridonneau-Parini Isabelle , Sory Marie-Paule , Cornelis Guy R. 
Published: July 2002

ABSTRACTYersinia enterocoliticais a pathogen endowed with two adhesins, Inv and YadA, and with the Ysc type III secretion system, which allows extracellular adherent bacteria to inject Yop effectors into the cytosol of animal target cells. We tested the influence of all of these virulence determinants on opsonic and nonopsonic phagocytosis by PU5-1.8 and J774 mouse macrophages, as well as by human polymorphonuclear leukocytes (PMNs). The adhesins contributed to phagocytosis in the absence of opsonins but not in the presence of opsonins. In agreement with previous results, YadA counteracted opsonization. In every instance, the Ysc-Yop system conferred a significant level of resistance to phagocytosis. Nonopsonized single-mutant bacteria lacking either YopE, -H, -T, or -O were phagocytosed significantly more by J774 cells and by PMNs. Opsonized bacteria were phagocytosed more than nonopsonized bacteria, and mutant bacteria lacking either YopH, -T, or -O were phagocytosed significantly more by J774 cells and by PMNs than were wild-type (WT) bacteria. Opsonized mutants lacking only YopE were phagocytosed significantly more than were WT bacteria by PMNs but not by J774 cells. Thus, YopH, -T, and -O were involved in all of the phagocytic processes studied here but YopE did not play a clear role in guarding against opsonic phagocytosis by J774. Mutants lacking YopP and YopM were, in every instance, as resistant as WT bacteria. Overexpression of YopE, -H, -T, or -O alone did not confer resistance to phagocytosis, although it affected the cytoskeleton. These results show that YopH, YopT, YopO, and, in some instances, YopE act synergistically to increase the resistance ofY. enterocoliticato phagocytosis by macrophages and PMNs.
Pathogenesis of Pneumococcal Pneumonia in Cyclophosphamide-Induced Leukopenia in Mice
Authors: Wang Erjian , Simard Marie , Ouellet Nathalie , Bergeron Yves , Beauchamp Denis , Bergeron Michel G. 
Published: July 2002

ABSTRACTStreptococcus pneumoniaepneumonia frequently occurs in leukopenic hosts, and most patients subsequently develop lung injury and septicemia. However, few correlations have been made so far between microbial growth, inflammation, and histopathology of pneumonia in specific leukopenic states. In the present study, the pathogenesis of pneumococcal pneumonia was investigated in mice rendered leukopenic by the immunosuppressor antineoplastic drug cyclophosphamide. Compared to the immunocompetent state, cyclophosphamide-induced leukopenia did not hamper interleukin-1 (IL-1), IL-6, macrophage inflammatory protein-1 (MIP-1), MIP-2, and monocyte chemotactic protein-1 secretion in infected lungs. Leukopenia did not facilitate bacterial dissemination into the bloodstream despite enhanced bacterial proliferation into lung tissues. Pulmonary capillary permeability and edema as well as lung injury were enhanced in leukopenic mice despite the absence of neutrophilic and monocytic infiltration into their lungs, suggesting an important role for bacterial virulence factors and making obvious the fact that neutrophils are ultimately not required for lung injury in this model. Scanning and transmission electron microscopy revealed extensive disruption of alveolar epithelium and a defect in surfactant production, which were associated with alveolar collapse, hemorrhage, and fibrin deposits in alveoli. These results contrast with those observed in immunocompetent animals and indicate that leukopenic hosts suffering from pneumococcal pneumonia are at a higher risk of developing diffuse alveolar damage.
Variation in Extracellular Protease Production among Clinical Isolates of
Staphylococcus aureus
Due to Different Levels of Expression of the Protease Repressor
sarA
Authors: Karlsson Anna , Arvidson Staffan 
Published: July 2002

ABSTRACT

Staphylococcus aureus
produces four major extracellular proteases: staphylococcal serine protease (V8 protease; SspA), cysteine protease (SspB), metalloprotease (aureolysin; Aur), and staphopain (Scp). Several in vitro studies have suggested that these enzymes are important virulence factors. Here we analyzed the protease production of 92
S. aureus
strains from infected human soft tissue. Twenty-one strains produced variable zones of proteolysis on casein agar plates, while the remaining 71 strains appeared to be protease negative. The major protease genes were present in all protease-positive (
n
= 5) and protease-negative (
n
= 12) strains analyzed. Northern blotting showed that transcription of the protease genes was suppressed due to increased sigma factor B (SigB)-dependent expression of the protease repressor SarA. Other SigB-dependent traits such as pigmentation and expression of
asp
23 were also increased in protease-negative compared to protease-positive strains. Inactivation of
sarA
in three protease-negative strains resulted in increased transcription of all protease genes and increased protease production, while overexpression of
sarA
in a strain producing protease at high levels repressed protease production. Our results suggest that the protease genes are conserved among clinical
S. aureus
strains and that the level of SigB-dependent expression of the protease repressor
sarA
determines the level of protease production in each strain.
Induction of Cell-Mediated Immunity toStaphylococcus aureusin the Mouse Mammary Gland by Local Immunization with a Live Attenuated Mutant
Authors: Gómez Marisa I. , Sordelli Daniel O. , Buzzola Fernanda R. , García Verónica E. 
Published: July 2002

ABSTRACTThe efficacy of intramammary (Ima) immunization with a live attenuated (la)Staphylococcus aureusmutant to protect the mouse mammary gland from infection has previously been established. The present study was aimed at evaluating whetherImaimmunization withla-S. aureuscan induce cell-mediated immune responses to the pathogen within the mammary gland. Mice were immunized byImaroute withla-S. aureus, and regional lymph node mononuclear cells were obtained thereafter. A higher expression of the interleukin-2 receptor was found on B and T cells from immunized mice when they were compared with control mice. Immunization withla-S. aureusinduced strong proliferative responses toS. aureus. Moreover, significantly increased levels of gamma interferon (IFN-γ) were produced by CD4+T cells when lymphocytes from immunized mice, but not from control mice, were cultured in the presence of staphylococcal antigens. Moreover, a significant increase in the percentage of IFN-γ-producing CD4+and CD8+T cells was observed afterS. aureus Imachallenge in immunized mice compared to challenged control mice. Our results demonstrated thatImaimmunization withla-S. aureusinduced primed lymphocyte populations capable of responding against staphylococcal antigens during in vitro stimulation, as well as during in vivo infection byS. aureus. CD4+and CD8+T cells appear to be the main lymphocyte subpopulations involved in this response. It is suggested that IFN-γ production induced byImaimmunization may play a pivotal role in the eradication of intracellular staphylococci.