bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Serum Immune Complexes in a New Test That Accurately Confirms Early Lyme Disease and Active Infection with
Borrelia burgdorferi
Authors: Brunner Michael , Sigal Leonard H. 
Published: July 2002

ABSTRACT

The present recommendation for serologic confirmation of Lyme disease (LD) calls for immunoblotting in support of positive or equivocal ELISA.
Borrelia burgdorferi
releases large quantities of proteins, suggesting that specific antibodies in serum might be trapped in immune complexes (ICs), rendering the antibodies undetectable by standard assays using unmodified serum. Production of ICs requires ongoing antigen production, so persistence of IC might be a marker of ongoing or persisting infection. We developed an immunoglobulin M (IgM) capture assay (EMIBA) measuring IC-derived IgM antibodies and tested it using three well-defined LD populations (from an academic LD referral center, a well-described Centers for Disease Control and Prevention (CDC) serum bank, and a group of erythema migrans patients from whose skin lesions
B. burgdorferi
was grown) and controls (non-Lyme arthritis inflammatory joint disease, syphilis, multiple sclerosis, and nondisease subjects from a region where LD is endemic, perhaps the most relevant comparison group of all). Previous studies demonstrated that specific antigen-antibody complexes in the sera of patients with LD could be precipitated by polyethylene glycol and could then be disrupted with maintenance of the immunoreactivity of the released antibodies, that specific anti-
B. burgdorferi
IgM was concentrated in ICs, and that occasionally IgM to specific
B. burgdorferi
antigens was found in the IC but not in unprocessed serum. EMIBA compared favorably with commercial and CDC flagellin-enhanced enzyme-linked immunosorbent assays and other assays in confirming the diagnosis of LD. EMIBA confirmed early
B. burgdorferi
infection more accurately than the comparator assays. In addition, EMIBA more accurately differentiated seropositivity in patients with active ongoing infection from seroreactivity persisting long after clinically successful antibiotic therapy; i.e., EMIBA identified seroreactivity indicating a clinical circumstance requiring antibiotic therapy. Thus, EMIBA is a promising new assay for accurate serologic confirmation of early and/or active LD.
Quantitative Analysis of Mycobacterial and Propionibacterial DNA in Lymph Nodes of Japanese and European Patients with Sarcoidosis
Authors: Eishi Yoshinobu , Suga Moritaka , Ishige Ikuo , Kobayashi Daisuke , Yamada Tetsuo , Takemura Tamiko , Takizawa Touichiro , Koike Morio , Kudoh Shoji , Costabel Ulrich , Guzman Josune , Rizzato Gianfranco , Gambacorta Marcello , du Bois Ronald , Nicholson Andrew G. , Sharma Om P. , Ando Masayuki 
Published: July 2002

ABSTRACTThe cause(s) of sarcoidosis is unknown.Mycobacteriumspp. are suspected in Europe andPropionibacteriumspp. are suspected in Japan. The present international collaboration evaluated the possible etiological links between sarcoidosis and the suspected bacterial species. Formalin-fixed and paraffin-embedded sections of biopsy samples of lymph nodes, one from each of 108 patients with sarcoidosis and 65 patients with tuberculosis, together with 86 control samples, were collected from two institutes in Japan and three institutes in Italy, Germany, and England. Genomes ofPropionibacterium acnes,Propionibacterium granulosum,Mycobacterium tuberculosis,Mycobacterium aviumsubsp.paratuberculosis, andEscherichia coli(as the control) were counted by quantitative real-time PCR. EitherP. acnesorP. granulosumwas found in all but two of the sarcoid samples.M. aviumsubsp.paratuberculosiswas found in no sarcoid sample.M. tuberculosiswas found in 0 to 9% of the sarcoid samples but in 65 to 100% of the tuberculosis samples. In sarcoid lymph nodes, the total numbers of genomes ofP. acnesorP. granulosumwere far more than those ofM. tuberculosis. P. acnesorP. granulosumwas found in 0 to 60% of the tuberculosis and control samples, but the total numbers of genomes ofP. acnesorP. granulosumin such samples were less than those in sarcoid samples.Propionibacteriumspp. are more likely thanMycobacteriaspp. to be involved in the etiology of sarcoidosis, not only in Japanese but also in European patients with sarcoidosis.
Comparative Performance of Herpes Simplex Virus Type 1-Specific Serologic Assays from MRL and Meridian Diagnostics
Authors: Ribes Julie A. , Smith Angela , Hayes Marie , Baker Doris J. , Winters Jeffrey L. 
Published: July 2002

ABSTRACTTwo companies, MRL and Meridian Diagnostics, have developed Food and Drug Administration-approved herpes simplex virus type 1 type-specific enzyme immunoassays. The sensitivity, specificity, and overall testing efficiency of these assays were 98.2, 93.8, and 96.6% for MRL and 98.8, 99.0, and 98.1% for Meridian, making both of these kits suitable for use in the clinical lab.
Evaluation of Two Nested PCR Assays for Detection of
Histoplasma capsulatum
DNA in Human Tissue
Authors: Bialek Ralf , Feucht Antje , Aepinus Christian , Just-Nübling Gudrun , Robertson Valerie J. , Knobloch Jürgen , Hohle Rolf 
Published: July 2002

ABSTRACT

In order to evaluate the diagnostic relevance of two nested PCR assays for diagnosis of histoplasmosis in clinical specimens, 100 paraffin-embedded biopsy specimens were examined. Upon microscopy of tissue, 50 biopsy specimens were histoplasma positive and 50 were negative. Due to destruction by formalin fixation, successful extraction of amplifiable human DNA was limited to 29 and 33 samples, respectively. A product of the
Histoplasma capsulatum
nested PCR assay targeting the gene encoding the unique fungal 100-kDa-like protein was detected in 20 histopathologically positive biopsy specimens but in none of the microscopically negative samples. Sequencing revealed that all 20 products of 210 bp were identical to the sequence of
H. capsulatum
in the GenBank database. In contrast, the nested PCR assay targeting the fungal 18S rRNA genes amplified products in 26 histopathologically positive but also in 18 microscopically negative biopsy specimens. However, sequencing revealed that only 20 of these 44 PCR products (231 bp) were identical to the sequence of
H. capsulatum
. The remaining 24 sequences were homologous to those of several
Euascomycetes
. These PCR products were detected only in tissues possibly colonized by nonpathogenic fungi, possibly causing these nonspecific amplifications. The detection limit of both
H. capsulatum
nested PCR assays was 1 to 5 fungal cells per sample. The two assays were similarly sensitive in identifying
H. capsulatum
. In this preliminary study, the novel 100-kDa-like-protein gene nested PCR revealed a specificity of 100% without requiring sequencing, which was necessary for identification of the 18S ribosomal DNA nested PCR products in order to avoid a high rate of false-positive results.
Leaky Scanning Is the Predominant Mechanism for Translation of Human Papillomavirus Type 16 E7 Oncoprotein from E6/E7 Bicistronic mRNA
Authors: Stacey Simon N. , Jordan Deborah , Williamson Andrew J. K. , Brown Michael , Coote Joanna H. , Arrand John R. 
Published: July 2002

ABSTRACTHuman papillomaviruses (HPV) are unique in that they generate mRNAs that apparently can express multiple proteins from tandemly arranged open reading frames. The mechanisms by which this is achieved are uncertain and are at odds with the basic predictions of the scanning model for translation initiation. We investigated the unorthodox mechanism by which the E6 and E7 oncoproteins from human papillomavirus type 16 (HPV-16) can be translated from a single, bicistronic mRNA. The short E6 5′ untranslated region (UTR) was shown to promote translation as efficiently as a UTR fromXenopusβ-globin. Insertion of a secondary structural element into the UTR inhibited both E6 and E7 expression, suggesting that E7 expression depends on ribosomal scanning from the 5′ end of the mRNA. E7 translation was found to be cap dependent, but E6 was more dependent on capping and eIF4F activity than E7. Insertion of secondary structural elements at various points in the region upstream of E7 profoundly inhibited translation, indicating that scanning was probably continuous. Insertion of the E6 region betweenRenillaand firefly luciferase genes revealed little or no internal ribosomal entry site activity. However when E6 was located at the 5′ end of the mRNA, it permitted over 100-fold-higher levels of downstream cistron translation than did theRenillaopen reading frame. Internal AUGs in the E6 region with strong or intermediate Kozak sequence contexts were unable to inhibit E7 translation, but initiation at the E7 AUG was efficient and accurate. These data support a model in which E7 translation is facilitated by an extreme degree of leaky scanning, requiring the negotiation of 13 upstream AUGs. Ribosomal initiation complexes which fail to initiate at the E6 start codon can scan through to the E7 AUG without initiating translation, but competence to initiate is achieved once the E7 AUG is reached. These findings suggest that the E6 region of HPV-16 comprises features that sponsor both translation of the E6 protein and enhancement of translation at a downstream site.
Initial Interactions of Subgenus D Adenoviruses with A549 Cellular Receptors: Sialic Acid versus α
v
Integrins
Authors: Arnberg Niklas , Kidd Alistair H. , Edlund Karin , Olfat Farzad , Wadell Göran 
Published: July 2002

ABSTRACT

Selected members of the adenovirus family have been shown to interact with the coxsackie adenovirus receptor, α
v
integrins, and sialic acid on target cells. Initial interactions of subgenus D adenoviruses with target cells have until now been poorly characterized. Here, we demonstrate that adenovirus type 8 (Ad8), Ad19a, and Ad37 use sialic acid as a functional cellular receptor, whereas the Ad9 and Ad19 prototypes do not.
Early Alterations of the Receptor-Binding Properties of H1, H2, and H3 Avian Influenza Virus Hemagglutinins after Their Introduction into Mammals
Authors: Matrosovich Mikhail , Tuzikov Alexander , Bovin Nikolai , Gambaryan Alexandra , Klimov Alexander , Castrucci Maria R. , Donatelli Isabella , Kawaoka Yoshihiro 
Published: July 2002

ABSTRACT

Interspecies transmission of influenza A viruses circulating in wild aquatic birds occasionally results in influenza outbreaks in mammals, including humans. To identify early changes in the receptor binding properties of the avian virus hemagglutinin (HA) after interspecies transmission and to determine the amino acid substitutions responsible for these alterations, we studied the HAs of the initial isolates from the human pandemics of 1957 (H2N2) and 1968 (H3N2), the European swine epizootic of 1979 (H1N1), and the seal epizootic of 1992 (H3N3), all of which were caused by the introduction of avian virus HAs into these species. The viruses were assayed for their ability to bind the synthetic sialylglycopolymers 3′SL-PAA and 6′SLN-PAA, which contained, respectively, 3′-sialyllactose (the receptor determinant preferentially recognized by avian influenza viruses) and 6′-sialyl(
N
-acetyllactosamine) (the receptor determinant for human viruses). Avian and seal viruses bound 6′SLN-PAA very weakly, whereas the earliest available human and swine epidemic viruses bound this polymer with a higher affinity. For the H2 and H3 strains, a single mutation, 226Q→L, increased binding to 6′SLN-PAA, while among H1 swine viruses, the 190E→D and 225G→E mutations in the HA appeared important for the increased affinity of the viruses for 6′SLN-PAA. Amino acid substitutions at positions 190 and 225 with respect to the avian virus consensus sequence are also present in H1 human viruses, including those that circulated in 1918, suggesting that substitutions at these positions are important for the generation of H1 human pandemic strains. These results show that the receptor-binding specificity of the HA is altered early after the transmission of an avian virus to humans and pigs and, therefore, may be a prerequisite for the highly effective replication and spread which characterize epidemic strains.
The DNA of a Plant Retroviroid-Like Element Is Fused to Different Sites in the Genome of a Plant Pararetrovirus and Shows Multiple Forms with Sequence Deletions
Authors: Vera Antonio , Daròs José-Antonio , Flores Ricardo , Hernández Carmen 
Published: July 2002

ABSTRACT
Carnation small viroid-like RNA (CarSV RNA) and its homologous DNA are the two forms of a unique plant retroviroid-like system. CarSV RNA is a 275-nucleotide noninfectious viroid-like RNA, present in certain carnation plants, which can adopt hammerhead structures in both polarity strands and self-cleave accordingly. CarSV DNA is organized as a series of head-to-tail multimers forming part of extrachromosomal elements in which CarSV DNA sequences are fused to sequences of carnation etched ring virus (CERV), a plant pararetrovirus. Analysis of more than 30 CarSV-CERV DNA junctions showed that distinct regions of the viral genome seem able to interact with CarSV DNA. All these junctions were short nucleotide stretches common to both CarSV and CERV DNAs. This suggests a polymerase-driven mechanism for their origin involving an enzyme with low processivity, most likely the viral reverse transcriptase. This view was further supported by the observation that most of CarSV sequences forming part of the junctions correspond either to strong secondary structure motifs in the conformation proposed for CarSV RNA or to its self-cleavage sites, which may have facilitated polymerase jumping. Accompanying the most-abundant CarSV RNA, a series of CarSV RNAs with sequence deletions were previously characterized. Here we have identified some of their corresponding DNA forms, together with other CarSV DNA forms with deletions not found in any CarSV RNA species identified so far. Some of these CarSV DNA forms have also been detected fused to CERV sequences. The existence of these shortened CarSV DNA versions may provide a continuous input of their corresponding transcripts and explain the persistence of CarSV RNAs with defective hammerhead structures for which an RNA-RNA model of amplification seems unlikely.
The Epstein-Barr Virus Promoter Initiating B-Cell Transformation Is Activated by RFX Proteins and the B-Cell-Specific Activator Protein BSAP/Pax5
Authors: Tierney Rosemary , Kirby Helen , Nagra Jasdeep , Rickinson Alan , Bell Andrew 
Published: July 2002

ABSTRACT
Epstein-Barr virus (EBV)-induced B-cell growth transformation, a central feature of the virus' strategy for colonizing the human B-cell system, requires full virus latent gene expression and is initiated by transcription from the viral promoter Wp. Interestingly, when EBV accesses other cell types, this growth-transforming program is not activated. The present work focuses on a region of Wp which in reporter assays confers B-cell-specific activity. Bandshift studies indicate that this region contains three factor binding sites, termed sites B, C, and D, in addition to a previously characterized CREB site. Here we show that site C binds members of the ubiquitously expressed RFX family of proteins, notably RFX1, RFX3, and the associated factor MIBP1, whereas sites B and D both bind the B-cell-specific activator protein BSAP/Pax5. In reporter assays with mutant Wp constructs, the loss of factor binding to any one of these sites severely impaired promoter activity in B cells, while the wild-type promoter could be activated in non-B cells by ectopic BSAP expression. We suggest that Wp regulation by BSAP helps to ensure the B-cell specificity of EBV's growth-transforming function.
The ORF1 Products of Tombusviruses Play a Crucial Role in Lethal Necrosis of Virus-Infected Plants
Authors: Burgyán József , Hornyik Csaba , Szittya György , Silhavy Dániel , Bisztray György 
Published: July 2002

ABSTRACTHybrids of cymbidium ringspot (CymRSV) and carnation Italian ringspot (CIRV) tombusviruses were used to identify viral symptom determinants responsible for the generalized necrosis in tombusvirus-infected plants. Surprisingly, symptoms ofNicotiana benthamianainfected with CymRSV/CIRV hybrids were distinctly different. It was demonstrated that not all chimeras expressing wild-type (wt) levels of p19 protein caused systemic necrosis as both parents CymRSV and CIRV did. We showed here that hybrids containing chimeric ORF1 were not able to induce lethal necrosis even if the viral replication of these constructs was not altered significantly. However, if a wt p33 (product of ORF1) of CymRSV was provided intransin transgenic plants expressing p33 and its readthrough product p92, the lethal necrosis characteristic to tombusvirus infection was restored. In addition, the expression of p33 by a potato virus X viral vector inN. benthamianacaused severe chlorosis and occasionally necrosis, indicating the importance of p33 in wt symptoms of tombusviruses. Thus, our results provide evidence that elicitation of the necrotic phenotype requires the presence of the wt p33 in addition to the p19 protein of tombusviruses.
A Functional Complex of Adenovirus Proteins E1B-55kDa and E4orf6 Is Necessary To Modulate the Expression Level of p53 but Not Its Transcriptional Activity
Authors: Cathomen Toni , Weitzman Matthew D. 
Published: July 2002

ABSTRACT
In adenovirus-infected cells, binding of E1B-55kDa and E4orf6 to the tumor suppressor protein p53 inhibits its transcriptional activity and causes rapid turnover of the protein. To investigate the requirements of the E1B-E4orf6 complex to modulate p53 function, we generated an E4orf6 mutant that failed to associate functionally and physically with E1B-55kDa but still interacted with p53. We confirm that E4orf6 and E1B-55kDa reduce p53 transactivation individually and show that their combined inhibition is additive rather than synergistic. Furthermore, we found that downregulation of p53's expression level, but not transcriptional inhibition of p53, depends on a functional E1B-E4 complex. A functional interaction of E1B-55kDa with p53, on the other hand, is a prerequisite for both transcriptional repression and downregulation of p53. The separation of these two functions will enable further dissection of the requirements for oncogenicity by the E4orf6 protein.
Wide Range of Viral Load in Healthy African Green Monkeys Naturally Infected with Simian Immunodeficiency Virus
Authors: Goldstein Simoy , Ourmanov Ilnour , Brown Charles R. , Beer Brigitte E. , Elkins William R. , Plishka Ronald , Buckler-White Alicia , Hirsch Vanessa M. 
Published: July 2002

ABSTRACT

The distribution and levels of simian immunodeficiency virus (SIV) in tissues and plasma were assessed in naturally infected African green monkeys (AGM) of the vervet subspecies (
Chlorocebus pygerythrus
) by limiting-dilution coculture, quantitative PCR for viral DNA and RNA, and in situ hybridization for SIV expression in tissues. A wide range of SIV RNA levels in plasma was observed among these animals (<1,000 to 800,000 copies per ml), and the levels appeared to be stable over long periods of time. The relative numbers of SIV-expressing cells in tissues of two monkeys correlated with the extent of plasma viremia. SIV expression was observed in lymphoid tissues and was not associated with immunopathology. Virus-expressing cells were observed in the lamina propria and lymphoid tissue of the gastrointestinal tract, as well as within alveolar macrophages in the lung tissue of one AGM. The range of plasma viremia in naturally infected AGM was greater than that reported in naturally infected sooty mangabeys. However, the degree of viremia in some AGM was similar to that observed during progression to AIDS in human immunodeficiency virus-infected individuals. Therefore, containment of viremia is an unlikely explanation for the lack of pathogenicity of SIVagm in its natural host species, AGM.
Hepatitis B Virus X Protein Colocalizes to Mitochondria with a Human Voltage-Dependent Anion Channel, HVDAC3, and Alters Its Transmembrane Potential
Authors: Rahmani Zohra , Huh Kyung-Won , Lasher Robert , Siddiqui Aleem 
Published: July 2002

ABSTRACT
Understanding the mechanism(s) of action of the hepatitis B virus (HBV)-encoded protein HBx is fundamental to elucidating the underlying mechanisms of chronic liver disease and hepatocellular carcinoma caused by HBV infection. In our continued attempts to identify cellular targets of HBx, we have previously reported the identification of a novel cellular protein with the aid of a yeast two-hybrid assay. This cellular gene was identified as a third member of the family of human genes that encode the voltage-dependent anion channel (HVDAC3). In the present study, physical interaction between HBx and HVDAC3 was established by standard in vitro and in vivo methods. Confocal laser microscopy of transfected cells with respective expression vectors colocalized HVDAC3 and HBx to mitochondria. This novel, heretofore unreported subcellular distribution of HBx in mitochondria implies a functional role of HBx in functions associated with mitochondria. Using a stable cationic fluorophore dye, CMXRos, we show that HBx expression in cultured human hepatoma cells leads to alteration of mitochondrial transmembrane potential. Such functional roles of HBx in affecting mitochondrial physiology have implications for HBV-induced liver injury and the development of hepatocellular carcinoma.
Reovirus-Induced Apoptosis Requires Activation of Transcription Factor NF-κB
Authors: Connolly Jodi L. , Rodgers Steven E. , Clarke Penny , Ballard Dean W. , Kerr Lawrence D. , Tyler Kenneth L. , Dermody Terence S. 
Published: July 2002

ABSTRACT
Reovirus infection induces apoptosis in cultured cells and in vivo. To identify host cell factors that mediate this response, we investigated whether reovirus infection alters the activation state of the transcription factor nuclear factor kappa B (NF-κB). As determined in electrophoretic mobility shift assays, reovirus infection of HeLa cells leads to nuclear translocation of NF-κB complexes containing Rel family members p50 and p65. Reovirus-induced activation of NF-κB DNA-binding activity correlated with the onset of NF-κB-directed transcription in reporter gene assays. Three independent lines of evidence indicate that this functional form of NF-κB is required for reovirus-induced apoptosis. First, treatment of reovirus-infected HeLa cells with a proteasome inhibitor prevents NF-κB activation following infection and substantially diminishes reovirus-induced apoptosis. Second, transient expression of a dominant-negative form of IκB that constitutively represses NF-κB activation significantly reduces levels of apoptosis triggered by reovirus infection. Third, mutant cell lines deficient for either the p50 or p65 subunits of NF-κB are resistant to reovirus-induced apoptosis compared with cells expressing an intact NF-κB signaling pathway. These findings indicate that NF-κB plays a significant role in the mechanism by which reovirus induces apoptosis in susceptible host cells.