bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Evaluation of a Rapid Immunochromatographic Test for Tuberculosis
Authors: Gounder Celine , de Queiroz Mello Fernanda Carvalho , Conde Marcus B. , Bishai William R. , Kritski Afrânio L. , Chaisson Richard E. , Dorman Susan E. 
Published: July 2002

ABSTRACT

Rapid diagnostic tests for tuberculosis (TB) are needed to facilitate early treatment of TB and prevention of
Mycobacterium tuberculosis
transmission. The ICT Tuberculosis test is a rapid, card-based immunochromatographic test for detection of antibodies directed against
M. tuberculosis
antigens. The objective of the study was to evaluate the performance of the ICT Tuberculosis test for the diagnosis of active pulmonary TB (PTB) with whole blood, plasma, and serum from patients suspected of having PTB and from asymptomatic controls in a setting with a high prevalence of PTB. Seventy patients suspected of having PTB (and who were later confirmed to have or not to have PTB by use of
M. tuberculosis
culture as the “gold standard”) and 42 controls were studied. Twenty-one controls were neither vaccinated with
Mycobacterium bovis
bacillus Calmette-Guérin (BCG) nor tuberculin skin test (TST) positive (group A controls), and 21 controls were TST positive and/or had previously been vaccinated with BCG (group B controls). Study subjects were drawn from one hospital and one primary health care unit in Rio de Janeiro City, Brazil. One version of the test (ICT-1) was evaluated by using whole blood, plasma, and serum samples. Sera obtained for this study were frozen and later tested with a manufacturer-modified version of the test (ICT-2). Among the patients suspected of having PTB, the sensitivities of the ICT-1 with whole blood, serum, and plasma were 83, 65, and 70%, respectively, and the specificities were 46, 67, and 56%, respectively. Among the group A controls, the specificities of ICT-1 with the three specimen types were 95, 100, and 95%, respectively. Among the group B controls, the specificities of ICT-1 with the three specimen types were 71, 86, and 86%, respectively. Among the patients suspected of having PTB, the sensitivity of ICT-2 was 70% and the specificity was 65%. Among the group A controls, the specificity of ICT-2 was 95%, and among the group B controls, the specificity of ICT-2 was 81%. With a 29% observed prevalence of PTB among patients suspected of having PTB, the positive predictive values of the ICT tests ranged from 39 to 50% and the negative predictive values ranged from 82 to 87%. The ICT Tuberculosis tests were not sufficiently predictive to warrant their widespread use as routine diagnostic tests for PTB in this setting. However, further evaluation of these tests in specific epidemiologic settings may be warranted.
Pulmonary Infiltrates in Immunosuppressed Patients: Analysis of a Diagnostic Protocol
Authors: Danés Cristina , González-Martín Julián , Pumarola Tomàs , Rañó Ana , Benito Natividad , Torres Antoni , Moreno Asunción , Rovira Montserrat , Puig de la Bellacasa Jorge 
Published: July 2002

ABSTRACT
A diagnostic protocol was started to study the etiology of pulmonary infiltrates in immunosuppressed patients. The diagnostic yields of the different techniques were analyzed, with special emphasis on the importance of the sample quality and the role of rapid techniques in the diagnostic strategy. In total, 241 patients with newly developed pulmonary infiltrates within a period of 19 months were included. Noninvasive or invasive evaluation was performed according to the characteristics of the infiltrates. Diagnosis was achieved in 202 patients (84%); 173 patients (72%) had pneumonia, and specific etiologic agents were found in 114 (66%). Bronchoaspirate and bronchoalveolar lavage showed the highest yields, either on global analysis (23 of 35 specimens [66%] and 70 of 134 specimens [52%], respectively) or on analysis of each type of pneumonia. A tendency toward better results with optimal-quality samples was observed, and a statistically significant difference was found in sputum bacterial culture. Rapid diagnostic tests yielded results in 71 of 114 (62.2%) diagnoses of etiological pneumonia.
Adaptation and Selection of Prion Protein Strain Conformations following Interspecies Transmission of Transmissible Mink Encephalopathy
Authors: Bartz Jason C. , Bessen Richard A. , McKenzie Debbie , Marsh Richard F. , Aiken Judd M. 
Published: July 2002

ABSTRACT

Interspecies transmission of the transmissible spongiform encephalopathies (TSEs), or prion diseases, can result in the adaptation and selection of TSE strains with an expanded host range and increased virulence such as in the case of bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease. To investigate TSE strain adaptation, we serially passaged a biological clone of transmissible mink encephalopathy (TME) into Syrian golden hamsters and examined the selection of distinct strain phenotypes and conformations of the disease-specific isoform of the prion protein (PrP
Sc
). The long-incubation-period drowsy (DY) TME strain was the predominate strain, based on the presence of its strain-specific PrP
Sc
following interspecies passage. Additional serial passages in hamsters resulted in the selection of the hyper (HY) TME PrP
Sc
strain-dependent conformation and its short incubation period phenotype unless the passages were performed with a low-dose inoculum (e.g., 10
−5
dilution), in which case the DY TME clinical phenotype continued to predominate. For both TME strains, the PrP
Sc
strain pattern preceded stabilization of the TME strain phenotype. These findings demonstrate that interspecies transmission of a single cloned TSE strain resulted in adaptation of at least two strain-associated PrP
Sc
conformations that underwent selection until one type of PrP
Sc
conformation and strain phenotype became predominant. To examine TME strain selection in the absence of host adaptation, hamsters were coinfected with hamster-adapted HY and DY TME. DY TME was able to interfere with the selection of the short-incubation HY TME phenotype. Coinfection could result in the DY TME phenotype and PrP
Sc
conformation on first passage, but on subsequent passages, the disease pattern converted to HY TME. These findings indicate that during TSE strain adaptation, there is selection of a strain-specific PrP
Sc
conformation that can determine the TSE strain phenotype.
Molecular Characterization of an Avian Astrovirus
Authors: Koci Matthew D. , Seal Bruce S. , Schultz-Cherry Stacey 
Published: July 2002

ABSTRACT
Astroviruses are known to cause enteric disease in several animal species, including turkeys. However, only human astroviruses have been well characterized at the nucleotide level. Herein we report the nucleotide sequence, genomic organization, and predicted amino acid sequence of a turkey astrovirus isolated from poults with an emerging enteric disease.
CD4-Independent, CCR5-Dependent Simian Immunodeficiency Virus Infection and Chemotaxis of Human Cells
Authors: Iyengar Sujatha , Schwartz David H. , Clements Janice E. , Hildreth James E. K. 
Published: July 2002

ABSTRACTMost simian immunodeficiency virus (SIV), human immunodeficiency virus type 2 (HIV-2), and HIV-1 infection of host peripheral blood mononuclear cells (PBMCs) is CD4 dependent. In some cases, X4 HIV-1 chemotaxis is CD4 independent, and cross-species transmission might be facilitated by CD4-independent entry, which has been demonstrated for some SIV strains in CD4−non-T cells. As expected for CCR5-dependent virus, SIV required CD4 on rhesus and pigtail macaque PBMCs for infection and chemotaxis. However, SIV induced the chemotaxis of human PBMCs in a CD4-independent manner. Furthermore, in contrast to the results of studies using transfected human cell lines, SIV did not require CD4 binding to productively infect primary human PBMCs. CD4-independent lymphocyte and macrophage infection may facilitate cross-species transmission, while reacquisition of CD4 dependence may confer a selective advantage for the virus within new host species.
Evaluation of Hepatitis C Virus Glycoprotein E2 for Vaccine Design: an Endoplasmic Reticulum-Retained Recombinant Protein Is Superior to Secreted Recombinant Protein and DNA-Based Vaccine Candidates
Authors: Heile Jens M. , Fong Yiu-Lian , Rosa Domenico , Berger Kim , Saletti Giulietta , Campagnoli Susanna , Bensi Giuliano , Capo Sabrina , Coates Steve , Crawford Kevin , Dong Christine , Wininger Mark , Baker Gary , Cousens Larry , Chien David , Ng Philip , Archangel Phillip , Grandi Guido , Houghton Michael , Abrignani Sergio 
Published: July 2002

ABSTRACT
Hepatitis C virus (HCV) is the leading causative agent of blood-borne chronic hepatitis and is the target of intensive vaccine research. The virus genome encodes a number of structural and nonstructural antigens which could be used in a subunit vaccine. The HCV envelope glycoprotein E2 has recently been shown to bind CD81 on human cells and therefore is a prime candidate for inclusion in any such vaccine. The experiments presented here assessed the optimal form of HCV E2 antigen from the perspective of antibody generation. The quality of recombinant E2 protein was evaluated by both the capacity to bind its putative receptor CD81 on human cells and the ability to elicit antibodies that inhibited this binding (NOB antibodies). We show that truncated E2 proteins expressed in mammalian cells bind with high efficiency to human cells and elicit NOB antibodies in guinea pigs only when purified from the core-glycosylated intracellular fraction, whereas the complex-glycosylated secreted fraction does not bind and elicits no NOB antibodies. We also show that carbohydrate moieties are not necessary for E2 binding to human cells and that only the monomeric nonaggregated fraction can bind to CD81. Moreover, comparing recombinant intracellular E2 protein to several E2-encoding DNA vaccines in mice, we found that protein immunization is superior to DNA in both the quantity and quality of the antibody response elicited. Together, our data suggest that to elicit antibodies aimed at blocking HCV binding to CD81 on human cells, the antigen of choice is a mammalian cell-expressed, monomeric E2 protein purified from the intracellular fraction.
Two Putative α-Helical Domains of Human Immunodeficiency Virus Type 1 Vpr Mediate Nuclear Localization by at Least Two Mechanisms
Authors: Kamata Masakazu , Aida Yoko 
Published: July 2002

ABSTRACT
To identify the domains of Vpr that are involved nuclear localization, we transfected HeLa cells with a panel of expression vectors that encode mutant Vpr protein with deletions or substitutions within putative domains. Immunofluorescence staining of transfected cells revealed that wild-type Vpr was localized predominantly in the nucleus and the nuclear envelope and certainly in the cytoplasm. Introduction of substitutions or deletions within αH1 or αH2 resulted, by contrast, in diffuse expression over the entire cell. In addition, double mutations within both of these α-helical domains led to the complete absence of Vpr from nuclei. Next, we prepared HeLa cells that express chimeric proteins which consist of the αH1 and αH2 domains fused individually with green fluorescent protein (GFP) and a Flag tag and extracted them with digitonin and Triton X-100 prior to fixation. Flag-αH1-GFP was detected in the nucleus but not in the cytoplasm, while Flag-αH2-GFP was retained predominantly in the nucleus and in a small amount in the cytoplasm. The immunostaining patterns were almost eliminated by substitutions in each chimeric protein. Thus, it appeared that the two α-helical domains might be involved in nuclear import by binding to certain cellular factors. Taken together, our data suggest that the two putative α-helical domains mediate the nuclear localization of Vpr by at least two mechanisms.
The Mouse Mammary Tumor Virus Transcription Enhancers for Hematopoietic Progenitor and Mammary Gland Cells Share Functional Elements
Authors: Reuss Frank U. , Coffin John M. 
Published: July 2002

ABSTRACT

Expression of mouse mammary tumor virus (MMTV)-encoded superantigens in B lymphocytes is required for viral transmission and pathogenesis. We have previously established a critical role of an enhancer element within the long terminal repeat (LTR) for MMTV
sag
gene expression in B-lymphoid progenitor cells. We now demonstrate enhancer activity of this element in a promyelocytic progenitor cell line. We also map the position of the enhancer within the U3 region of the MMTV LTR and show that the progenitor cell enhancer shares functional elements with a previously described mammary gland-specific enhancer.
Interaction of Cellular Proteins with the 5′ End of Norwalk Virus Genomic RNA
Authors: Gutiérrez-Escolano Ana Lorena , Brito Zamirath Uribe , del Angel Rosa M. , Jiang Xi 
Published: July 2002

ABSTRACT
The lack of a susceptible cell line and an animal model for Norwalk virus (NV) infection has prompted the development of alternative strategies to generate in vitro RNAs that approximate the authentic viral genome. This approach has allowed the study of viral RNA replication and gene expression. In this study, using mobility shift and cross-linking assays, we detected several cellular proteins from HeLa and CaCo-2 cell extracts that bind to, and form stable complexes with, the first 110 nucleotides of the 5′ end of NV genomic RNA, a region previously predicted to form a double stem-loop structure. These proteins had molecular weights similar to those of the HeLa cellular proteins that bind to the internal ribosomal entry site of poliovirus RNA. HeLa proteins La, PCBP-2, and PTB, which are important for poliovirus translation, and hnRNP L, which is possibly implicated in hepatitis C virus translation, interact with NV RNA. These protein-RNA interactions are likely to play a role in NV translation and/or replication.
Putative Immunodominant Human Immunodeficiency Virus-Specific CD8+T-Cell Responses Cannot Be Predicted by Major Histocompatibility Complex Class I Haplotype
Authors: Betts Michael R. , Casazza Joseph P. , Patterson Brent A. , Waldrop Shar , Trigona Wendy , Fu Tong-Ming , Kern Florian , Picker Louis J. , Koup Richard A. 
Published: July 2002

ABSTRACTRecent studies of human immunodeficiency virus (HIV)-specific CD8+T cells have focused on responses to single, usually HLA-A2-restricted epitopes as surrogate measures of the overall response to HIV. However, the assumption that a response to one epitope is representative of the total response is unconfirmed. Here we assess epitope immunodominance and HIV-specific CD8+T-cell response complexity using cytokine flow cytometry to examine CD8+T-cell responses in 11 HLA-A2+HIV+individuals. Initial studies demonstrated that only 4 of 11 patients recognized the putative immunodominant HLA-A2-restricted p17 epitope SLYNTVATL, suggesting that the remaining subjects might lack significant HIV-specific CD8+T-cell responses. However, five of six SLYNTVATL nonresponders recognized other HIV epitopes, and two of four SLYNTVATL responders had greater responses to HIV peptides restricted by other class I alleles. In several individuals, no HLA-A2-restricted epitopes were recognized, but CD8+T-cell responses were detected to epitopes restricted by other HLA class I alleles. These data indicate that an individual's overall CD8+T-cell response to HIV is not adequately represented by the response to a single epitope and that individual major histocompatibility complex class I alleles do not predict an immunodominant response restricted by that allele. Accurate quantification of total HIV-specific CD8+T-cell responses will require assessment of the response to all possible epitopes.
Combination of CCR5 and CXCR4 Inhibitors in Therapy of Human Immunodeficiency Virus Type 1 Infection: In Vitro Studies of Mixed Virus Infections
Authors: Rusconi Stefano , La Seta Catamancio Simona , Citterio Paola , Bulgheroni Elisabetta , Croce Francesco , Herrmann Steven H. , Offord Robin E. , Galli Massimo , Hirsch Martin S. 
Published: July 2002

ABSTRACT
We studied the combined anti-human immunodeficiency virus type 1 (HIV-1) effects of a derivative of stroma-derived factor 1β (SDF-1β), Met-SDF-1β, and a modified form of RANTES, aminooxypentane (AOP)-RANTES. The antiviral agents were tested singly or in combination at 95 and 99% virus inhibitory concentrations. Clinical R5 and X4 HIV-1 isolates were used. AOP-RANTES inhibited R5 but not X4 viruses, whereas Met-SDF-1β had the opposite effect. Combinations of these compounds inhibited mixed infections with R5 and X4 viruses (95 to 99%), whereas single drugs were less inhibitory (32 to 61%). Combinations of R5 and X4 inhibitors are promising and deserve further evaluation.
Second-Site Changes Affect Viability of Amphotropic/Ecotropic Chimeric Enveloped Murine Leukemia Viruses
Authors: O'Reilly Lucille , Roth Monica J. 
Published: July 2002

ABSTRACT

Chimeras were previously generated between the ecotropic (Moloney-MuLV) and amphotropic (4070A) SU and TM proteins of murine leukemia virus (MuLV). After passage in D17 cells, three chimeras with junctions in the C terminus of SU (AE5, AE6, and AE7), showed improved kinetics of viral spreading, suggesting that they had adapted. Sequencing of the viruses derived from the D17 cell lines revealed second-site changes within the
env
gene. Changes were detected in the receptor binding domain, the proline-rich region, the C terminus of SU, and the ectodomain of TM. Second-site changes were subcloned into the parental DNA, singly and in combination, and tested for viability. All viruses had maintained their original cloned mutations and junctions. Reconstruction and passage of AE7 or AE6 virus with single point mutations recovered the additional second-site changes identified in the parental population. The AE5 isolate required changes in the VRA, the VRC, the VRB-hinge region, and the C terminus of SU for efficient infection. Passage of virus, including the parental 4070A, in D17 cells resulted in a predominant G100R mutation within the receptor binding domain. Viruses were subjected to titer determination in three cell types, NIH 3T3, canine D17, and 293T. AE6 viruses with changes in the proline-rich region initially adapted for growth on D17 cells could infect all cell types tested. AE6-based chimeras with additional mutations in the C terminus of SU could infect D17 and 293T cells. Infection of NIH 3T3 cells was dependent on the proline-rich mutation. AE7-based chimeras encoding L538Q and G100R were impaired in infecting NIH 3T3 and 293T cells.
A TVA–Single-Chain Antibody Fusion Protein Mediates Specific Targeting of a Subgroup A Avian Leukosis Virus Vector to Cells Expressing a Tumor-Specific Form of Epidermal Growth Factor Receptor
Authors: Snitkovsky Sophie , Niederman Thomas M. J. , Carter Bob S. , Mulligan Richard C. , Young John A. T. 
Published: July 2002

ABSTRACT
We have previously described an approach that employs retroviral receptor-ligand bridge proteins to target retroviral vectors to specific cell types. To determine whether targeted retroviral entry can also be achieved using a retroviral receptor–single-chain antibody bridge protein, the TVA-MR1 fusion protein was generated. TVA-MR1 is comprised of the extracellular domain of the TVA receptor for subgroup A avian leukosis viruses (ALV-A), fused to the MR1 single-chain antibody that binds specifically to EGFRvIII, a tumor-specific form of the epidermal growth factor receptor. We show that TVA-MR1 binds specifically to a murine version of EGFRvIII and promotes ALV-A entry selectively into cells that express this cell surface marker. These studies demonstrate that it is possible to target retroviral vectors to specific cell types through the use of a retroviral receptor–single-chain antibody fusion protein.
Cytopathicity of Human Immunodeficiency Virus Type 2 (HIV-2) in Human Lymphoid Tissue Is Coreceptor Dependent and Comparable to That of HIV-1
Authors: Schramm Birgit , Penn Michael L. , Palacios Emil H. , Grant Robert M. , Kirchhoff Frank , Goldsmith Mark A. 
Published: July 2002

ABSTRACT
Epidemiological studies have shown that human immunodeficiency virus type 2 (HIV-2) is markedly less pathogenic than HIV-1 in vivo. Individuals infected with HIV-2 exhibit a remarkably slow rate of disease development, and these clinical properties have been attributed presumptively to an “attenuated” phenotype of HIV-2 itself. Here, we investigated the impact of coreceptor usage on the cytopathicity of HIV-2 and compared its pathogenic potential with that of HIV-1 in a unique human lymphoid histoculture model. We found that HIV-2 strains, as well as closely related simian immunodeficiency viruses (SIV), displayed mildly or highly aggressive cytopathic phenotypes depending on their abilities to use the coreceptor CCR5 or CXCR4, respectively. A side-by-side comparison of primary X4 HIV-1 and HIV-2 strains revealed similar, high degrees of cytopathicity induced by both HIV types. Furthermore, we found that HIV-2 coreceptor specificity for CCR5 and CXCR4 determined the target cell population for T-cell depletion in lymphoid tissue. Finally, utilization of the alternate coreceptors BOB and Bonzo did not significantly increase the cytopathic properties of HIV-2. These findings demonstrate that coreceptor preference is a key regulator of target cell specificity and the cytopathic potential of HIV-2, with indistinguishable rules compared with HIV-1. Moreover, HIV-2 strains are not characterized by an intrinsically lower cytopathicity than HIV-1 strains. Therefore, direct cytopathic potential per se does not explain the unique behavior of HIV-2 in people, highlighting that other unknown factors need to be elucidated as the basis for their lesser virulence in vivo.
A Human Immunodeficiency Virus Prime-Boost Immunization Regimen in Humans Induces Antibodies That Show Interclade Cross-Reactivity and Neutralize Several X4-, R5-, and Dualtropic Clade B and C Primary Isolates
Authors: Verrier Florence , Burda Sherri , Belshe Robert , Duliege Anne-Marie , Excler Jean-Louis , Klein Michel , Zolla-Pazner Susan 
Published: July 2002

ABSTRACTA human immunodeficiency virus (HIV) vaccine that will be useful in diverse geographic regions will need to induce a broad immune response characterized by cross-clade immunity. To test whether a clade B-based HIV candidate vaccine could induce interclade humoral responses, including neutralizing activity against primary HIV-1 isolates, sera were tested from recipients of a vaccine consisting of recombinant canarypox virus vCP205 and recombinant gp120SF2. Serum antibodies exhibited strong immunochemical cross-reactivity with V3 peptides from clades B, C, and F, with weaker activity for several V3 peptides from clades A, D, G, and H; essentially no reactivity could be demonstrated with V3 peptides from clades E and O. Extensive cross-clade reactivity was also documented by enzyme-linked immunosorbent assay with all nine recombinant HIV envelope glycoproteins tested from clades B, D, and E. In addition, vaccinees' sera displayed significant neutralizing activity against 5 of 14 primary isolates tested, including one X4 virus and two dualtropic viruses (from clade B) and two R5 viruses (from clades B and C). This is the first demonstration of the induction by a candidate HIV vaccine constructed from clade B laboratory strains of HIV of neutralizing activity against R5 and clade C primary isolates. The data suggest that, by virtue of their ability to induce cross-clade immune responses, appropriately formulated HIV vaccines based on a finite number of HIV isolates may ultimately be able to protect against the wide range of HIV isolates affecting the populations of many geographic regions.