bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Eleven Commercial Tests for
Chlamydia pneumoniae
-Specific Immunoglobulin G in Asymptomatic Healthy Individuals
Authors: Hermann Corinna , Graf Kathrin , Groh Annemarie , Straube Eberhard , Hartung Thomas 
Published: July 2002

ABSTRACT

The seroprevalence of anti-
Chlamydia pneumoniae
-specific immunoglobulin G (IgG) antibodies is high in the adult population. Experience is required to perform a microimmunofluorescence test (MIF), the current “gold standard” for serological diagnosis, and the assay still lacks standardization. Partially automated enzyme-linked immunosorbent assays (ELISAs) and enzyme immunoassays (EIAs), which are more standardized and for which the reading of results is less subjective, have been developed. The different commercially available serological tests differ in their sensitivities and specificities, depending primarily on the antigen used. Therefore, we evaluated 11 different tests (10 were species specific, 1 was genus specific) for IgG antibodies using serum samples of 80 apparently healthy volunteers. The interpretation of the results was based on the results of the gold standard, MIF: a sample was judged positive if it was positive by at least three of the four different MIFs. Based on this internal standard, we found that 71% of the samples were positive, while 8% were false positive by some tests. The correlations between the results of the different MIFs ranged from 83 to 99%, and the correlations between the results of the MIFs and the different ELISAs and EIAs ranged from 78 to 98%. Comparison of the IgG titers measured by MIF showed good agreement (
r
= 0.76 to 0.91). This analysis revealed that some ELISAs and EIAs fail to detect low IgG titers. The specificities of the species-specific tests varied from 95 to 100%, and the sensitivities varied from 58 to 100%. These results indicate that serological assays for the detection of anti-
C. pneumoniae
-specific IgG vary greatly in their sensitivities and specificities. MIF must still be considered the best method for the detection of IgG in apparently healthy subjects, but the sensitivities and specificities of new ELISAs approximate those of MIFs.
Candida glabrataOropharyngeal Candidiasis in Patients Receiving Radiation Treatment for Head and Neck Cancer
Authors: Redding Spencer W. , Kirkpatrick William R. , Coco Brent J. , Sadkowski Lee , Fothergill Annette W. , Rinaldi Michael G. , Eng Tony Y. , Patterson Thomas F. 
Published: July 2002

ABSTRACTCandida glabratacolonization is common in patients receiving radiation treatment for head and neck cancer, but to our knowledge has never been described as the infecting organism with oropharyngeal candidiasis (OPC). This study presents the first three patients described withC.glabrataOPC in this patient population. Patient 1 developedC.glabrataOPC and required fluconazole, 800 mg/day, for clinical resolution. Antifungal susceptibility testing revealed a MIC of fluconazole of >64 μg/ml. Elapsed time from initial culturing to treatment decision was 7 days. Patients 2 and 3 developedC.glabrataOPC. They were patients in a study evaluating OPC infections, and cultures were taken immediately. CHROMagarCandidaplates with 0, 8, and 16 μg of fluconazole/ml were employed for these cultures. Lavender colonies, consistent withC.glabrata, grew on the 0- and 8-μg plates but not on the 16-μg plate from patient 2 and grew on all three plates from patient 3. Based on these data, a fluconazole dose of 200 mg/day was chosen for patient 2 and a dose of 400 mg/day was chosen for patient 3, with clinical resolution in both. Elapsed time from initial culturing to treatment decision was 2 days.C.glabratadoes cause OPC in head and neck radiation treatment patients, and the use of fluconazole-impregnated chromogenic agar may significantly reduce treatment decision time compared to that with conventional culturing and antifungal susceptibility testing.
Characterization of Unusual Bacteria Isolated from Respiratory Secretions of Cystic Fibrosis Patients and Description of
Inquilinus limosus
gen. nov., sp. nov
Authors: Coenye Tom , Goris Johan , Spilker Theodore , Vandamme Peter , LiPuma John J. 
Published: July 2002

ABSTRACT

Using a polyphasic approach (including cellular protein and fatty acid analysis, biochemical characterization, 16S ribosomal DNA sequencing, and DNA-DNA hybridizations), we characterized 51 bacterial isolates recovered from respiratory secretions of cystic fibrosis (CF) patients. Our analyses showed that 24 isolates belong to taxa that have so far not (or only rarely) been reported from CF patients. These taxa include
Acinetobacter
sp.,
Bordetella hinzii
,
Burkholderia fungorum
,
Comamonas testosteroni
,
Chryseobacterium
sp.,
Herbaspirillum
sp.,
Moraxella osloensis
,
Pandoraea
genomospecies 4,
Ralstonia gilardii
,
Ralstonia mannitolilytica
,
Rhizobium radiobacter
, and
Xanthomonas
sp. In addition, one isolate most likely represents a novel
Ralstonia
species, whereas nine isolates belong to novel taxa within the α-
Proteobacteria
. Eight of these latter isolates are classified into the novel genus
Inquilinus
gen. nov. as
Inquilinus limosus
gen. nov., sp. nov., or as
Inquilinus
sp. The remaining 17 isolates are characterized as members of the family
Enterobacteriaceae
. The recovery of these species suggests that the CF lung is an ecological niche capable of supporting the growth of a wide variety of bacteria rarely seen in clinical samples. Elucidation of the factors that account for the association between these unusual species and the respiratory tract of CF patients may provide important insights into the pathophysiology of CF infection. Because accurate identification of these organisms in the clinical microbiology laboratory may be problematic, the present study highlights the utility of reference laboratories capable of identifying unusual species recovered from CF sputum.
Fatal Case of Pneumonia Caused by a Nonhemolytic Strain of
Streptococcus pyogenes
Authors: Taylor Mark B. , Barkham Timothy 
Published: July 2002

ABSTRACT

We report a case of pneumonia with a fatal outcome caused by a nonhemolytic strain of
Streptococcus pyogenes
. This strain was isolated in pure growth from blood cultures and was fully identified biochemically. Such strains will be difficult to recognize and isolate from sites with heavy growth of normal flora. This phenomenon has been reported sporadically before, and it is unknown how common such strains may be in pharyngeal samples.
Functional Analysis of the Genomic and Antigenomic Promoters of Human Respiratory Syncytial Virus
Authors: Fearns Rachel , Collins Peter L. , Peeples Mark E. 
Published: July 2002

ABSTRACT

The promoters involved in transcription and RNA replication by respiratory syncytial virus (RSV) were examined by using a plasmid-based minireplicon system. The 3′ ends of the genome and antigenome, which, respectively, contain the 44-nucleotide (nt) leader (Le) and 155-nt trailer-complement (TrC) regions, should each contain a promoter for RNA replication. The 3′ genome end also should have the promoter for transcription. Substitution for the Le with various lengths of TrC demonstrated that the 3′-terminal 36 nt of TrC are sufficient for extensive (but not maximal) replication and that when juxtaposed with a transcription gene-start (GS) signal, this sequence was also able to direct transcription. It was also shown that the region of Le immediately preceding the GS signal of the first gene could be deleted with either no effect or with a slight decrease in transcription initiation. Thus, the TrC is competent to direct transcription even though it does not do so in nature, and the partial sequence identity it shares with the 3′ end of the genome likely represents the important elements of a conserved promoter active in both replication and transcription. Increasing the length of the introduced TrC sequence incrementally to 147 nt resulted in a fourfold increase in replication and a nearly complete inhibition of transcription. These two effects were unrelated, implying that transcription and replication are not interconvertible processes mediated by a common polymerase, but rather are independent processes. The increase in replication was specific to the TrC sequence, implying the presence of a nonessential, replication-enhancing
cis
-acting element. In contrast, the inhibitory effect on transcription was due solely to the altered spacing between the 3′ end of the genome and GS signal, which implies that the transcriptase recognizes the first GS signal as a promoter element. Neither the enhancement of replication nor the inhibition of transcription was due to increased base-pairing potential between the 3′ and 5′ ends. The relative strengths of the Le and TrC promoters for directing RNA synthesis were compared and found to be very similar. Thus, these findings highlighted a high degree of functional similarity between the RSV antigenomic and genomic promoters, but provided a further distinction between promoter requirements for transcription and replication.
Gene Gun-Mediated DNA Immunization Primes Development of Mucosal Immunity against Bovine Herpesvirus 1 in Cattle
Authors: Loehr B. I. , Willson P. , Babiuk L. A. , van Drunen Littel-van den Hurk S. 
Published: July 2002

ABSTRACTVaccination by a mucosal route is an excellent approach to the control of mucosally acquired infections. Several reports on rodents suggest that DNA vaccines can be used to achieve mucosal immunity when applied to mucosal tissues. However, with the exception of one study with pigs and another with horses, there is no information on mucosal DNA immunization of the natural host. In this study, the potential of inducing mucosal immunity in cattle by immunization with a DNA vaccine was demonstrated. Cattle were immunized with a plasmid encoding bovine herpesvirus 1 (BHV-1) glycoprotein B, which was delivered with a gene gun either intradermally or intravulvomucosally. Intravulvomucosal DNA immunization induced strong cellular immune responses and primed humoral immune responses. This was evident after BHV-1 challenge when high levels of both immunoglobulin G (IgG) and IgA were detected. Intradermal delivery resulted in lower levels of immunity than mucosal immunization. To determine whether the differences between the immune responses induced by intravulvomucosal and intradermal immunizations might be due to the efficacy of antigen presentation, the distributions of antigen and Langerhans cells in the skin and mucosa were compared. After intravulvomucosal delivery, antigen was expressed early and throughout the mucosa, but after intradermal administration, antigen expression occurred later and superficially in the skin. Furthermore, Langerhans cells were widely distributed in the mucosal epithelium but found primarily in the basal layers of the epidermis of the skin. Collectively, these observations may account for the stronger immune response induced by mucosal administration.
Sequences of
Citrus Tristeza Virus
Separated in Time and Space Are Essentially Identical
Authors: Albiach-Martí María R. , Mawassi Munir , Gowda Siddarame , Satyanarayana Tatineni , Hilf Mark E. , Shanker Savita , Almira Ernesto C. , Vives María C. , López Carmelo , Guerri Jose , Flores Ricardo , Moreno Pedro , Garnsey Steve M. , Dawson William O. 
Published: July 2002

ABSTRACT

The first
Citrus tristeza virus
(CTV) genomes completely sequenced (19.3-kb positive-sense RNA), from four biologically distinct isolates, are unexpectedly divergent in nucleotide sequence (up to 60% divergence). Understanding of whether these large sequence differences resulted from recent evolution is important for the design of disease management strategies, particularly the use of genetically engineered mild (essentially symptomless)-strain cross protection and RNA-mediated transgenic resistance. The complete sequence of a mild isolate (T30) which has been endemic in Florida for about a century was found to be nearly identical to the genomic sequence of a mild isolate (T385) from Spain. Moreover, samples of sequences of other isolates from distinct geographic locations, maintained in different citrus hosts and also separated in time (B252 from Taiwan, B272 from Colombia, and B354 from California), were nearly identical to the T30 sequence. The sequence differences between these isolates were within or near the range of variability of the T30 population. A possible explanation for these results is that the parents of isolates T30, T385, B252, B272, and B354 have a common origin, probably Asia, and have changed little since they were dispersed throughout the world by the movement of citrus. Considering that the nucleotide divergence among the other known CTV genomes is much greater than those expected for strains of the same virus, the remarkable similarity of these five isolates indicates a high degree of evolutionary stasis in some CTV populations.
The Karyophilic Properties of Human Immunodeficiency Virus Type 1 Integrase Are Not Required for Nuclear Import of Proviral DNA
Authors: Petit Caroline , Schwartz Olivier , Mammano Fabrizio 
Published: July 2002

ABSTRACT
Integrase (IN) is a key component of the preintegration nucleoprotein complex (PIC), which transports the retroviral genome from the cytoplasm to the nucleus of newly infected cells. Retroviral IN proteins have intrinsic karyophilic properties, which for human immunodeficiency virus type 1 (HIV-1) are currently attributed to regions that display sequence homology to previously characterized nuclear localization signals. We asked here whether the karyophilic properties of HIV-1 IN are involved in the nuclear import of PIC. We mutated three conserved basic regions in the C-terminal domain of IN and analyzed the effects of mutations on subcellular localization of the protein, viral particle composition, IN dimerization within virions, and infectivity. Alteration of two sequences caused the loss of nuclear accumulation of IN and drastically reduced the capacity of the protein to multimerize. Mutation of the most C-terminal sequence had no effect on the subcellular localization and dimerization of IN. Nevertheless, conservation of all three sequences was required for viral infectivity. Despite the perturbation of IN subcellular localization, all mutant viruses displayed normal reverse transcription and nuclear transport of PICs in newly infected cells. The replicative defect was instead at the level of integration, for which all mutants were markedly affected in vivo. Besides reinforcing the association between dimerization of IN and nuclear accumulation of the enzyme, our data demonstrate that subcellular localization of IN alone cannot predict the fate of the PICs.
Effect of Coexpression of Interleukin-2 by Recombinant Respiratory Syncytial Virus on Virus Replication, Immunogenicity, and Production of Other Cytokines
Authors: Bukreyev Alexander , Whitehead Stephen S. , Prussin Calman , Murphy Brian R. , Collins Peter L. 
Published: July 2002

ABSTRACTWe constructed rRSV/mIL-2, a recombinant respiratory syncytial virus (rRSV) containing the coding sequence of murine interleukin-2 (mIL-2) in a transcription cassette inserted into the G-F intergenic region. The recovered virus (rRSV/mIL-2) expressed high levels (up to 2.8 μg/ml) of mIL-2 in cell culture. Replication of rRSV/mIL-2 in vitro was reduced up to 13.6-fold from that of wild-type (wt) rRSV, an effect that was due to the presence of the foreign insert but was not specific to mIL-2. Replication of the rRSV/mIL-2 virus in the upper and lower respiratory tracts of BALB/c mice was reduced up to 6.3-fold, an effect that was specific to mIL-2. The antibody response, including the levels of RSV-specific serum immunoglobulin G1 (IgG1), IgG2a, IgA, and total IgG, and the level of protective efficacy against wt RSV challenge were not significantly different from those of wt rRSV. Analysis of total pulmonary cytokine mRNA isolated 1 and 4 days following infection with rRSV/mIL-2 revealed elevated levels of mRNA for IL-2, gamma interferon (IFN-γ), IL-4, IL-5, IL-6, IL-10, IL-13, and IL-12 p40 compared to those for wt rRSV. Flow cytometry of total pulmonary mononuclear cells isolated 10 days following infection with rRSV/mIL-2 revealed increased levels of CD4+T lymphocytes expressing either IFN-γ or IL-4 compared to those of wt rRSV. These elevations in cytokine mRNA or cytokine-expressing CD4+cells relative to those of wt rRSV-primed animals were not observed following challenge with wt RSV on day 28. Thus, the expression of mIL-2 by rRSV was associated with a modest attenuation of virus growth in vivo, induction of serum antibodies at levels comparable to that of wt rRSV, and transient increases in both the Th1 and Th2 CD4+lymphocytes and cytokine mRNAs compared to those of wt rRSV.
Overexpression of Essential Splicing Factor ASF/SF2 Blocks the Temporal Shift in Adenovirus Pre-mRNA Splicing and Reduces Virus Progeny Formation
Authors: Molin Magnus , Akusjärvi Göran 
Published: July 2002

ABSTRACT
Expression of cytoplasmic mRNA from most adenovirus transcription units is subjected to a temporal regulation at the level of alternative pre-mRNA splicing. The general tendency is that splice site selection changes from proximal to distal late after infection. Interestingly, ASF/SF2, which is a prototypical member of the SR family of splicing factors, has the opposite effect on splice site selection, inducing an increase in proximal splice site usage. We have previously shown that SR proteins late during an adenovirus infection become partially inactivated as splicing regulatory proteins. A prediction from these results is that overexpression of an SR protein, such as ASF/SF2, during virus growth will interfere with virus replication by disturbing the balance of functional and nonfunctional ASF/SF2 in the infected cell. To test this hypothesis, we reconstructed a recombinant adenovirus expressing ASF/SF2 under the transcriptional control of a regulated promoter. The results show that, as predicted, induction of ASF/SF2 during lytic virus growth prevents the early to late shift in mRNA expression from both early (E1A and E1B) and late (L1) transcription units. Furthermore, ASF/SF2 overexpression blocks viral DNA replication and reduces selectively cytoplasmic accumulation of major late mRNA, resulting in a lower virus yield. Collectively, our results provide additional support for the hypothesis that viral control of SR protein function is important for the proper expression of viral proteins during lytic virus growth.
Uneven Distribution of Hepatitis C Virus Quasispecies in Tissues from Subjects with End-Stage Liver Disease: Confounding Effect of Viral Adsorption and Mounting Evidence for the Presence of Low-Level Extrahepatic Replication
Authors: Laskus Tomasz , Radkowski Marek , Wang Lian-Fu , Nowicki Marek , Rakela Jorge 
Published: July 2002

ABSTRACT
We have found differences among the populations of hepatitis C virus sequences in serum, peripheral blood mononuclear cells (PBMCs), and various tissues in patients with chronic hepatitis C. These results are compatible with the existence of independent viral compartments in the infected host. Our results also suggest that PBMCs, and probably various tissues, can selectively adsorb viral subpopulations differing in the E2 region.
Intrinsic Susceptibility of Rhesus Macaque Peripheral CD4+T Cells to Simian Immunodeficiency Virus In Vitro Is Predictive of In Vivo Viral Replication
Authors: Goldstein Simoy , Brown Charles R. , Dehghani Houman , Lifson Jeffrey D. , Hirsch Vanessa M. 
Published: July 2002

ABSTRACTPrevious studies with simian immunodeficiency virus (SIV) infection of rhesus macaques suggested that the intrinsic susceptibility of peripheral blood mononuclear cells (PBMC) to infection with SIV in vitro was predictive of relative viremia after SIV challenge. The present study was conducted to evaluate this parameter in a well-characterized cohort of six rhesus macaques selected for marked differences in susceptibility to SIV infection in vitro. Rank order relative susceptibility of PBMC to SIVsmE543-3-infection in vitro was maintained over a 1-year period of evaluation. Differential susceptibility of different donors was maintained in CD8+T-cell-depleted PBMC, macrophages, and CD4+T-cell lines derived by transformation of PBMC with herpesvirus saimiri, suggesting that this phenomenon is an intrinsic property of CD4+target cells. Following intravenous infection of these macaques with SIVsmE543-3, we observed a wide range in plasma viremia which followed the same rank order as the relative susceptibility established by in vitro studies. A significant correlation was observed between plasma viremia at 2 and 8 weeks postinoculation and in vitro susceptibility (P< 0.05). The observation that the two most susceptible macaques were seropositive for simian T-lymphotropic virus type 1 may suggests a role for this viral infection in enhancing susceptibility to SIV infection in vitro and in vivo. In summary, intrinsic susceptibility of CD4+target cells appears to be an important factor influencing early virus replication patterns in vivo that should be considered in the design and interpretation of vaccine studies using the SIV/macaque model.
Gene Transfer Using Recombinant Rabbit Hemorrhagic Disease Virus Capsids with Genetically Modified DNA Encapsidation Capacity by Addition of Packaging Sequences from the L1 or L2 Protein of Human Papillomavirus Type 16
Authors: El Mehdaoui Slimane , Touzé Antoine , Laurent Sylvie , Sizaret Pierre-Yves , Rasschaert Denis , Coursaget Pierre 
Published: July 2002

ABSTRACT
The aim of this study was to produce gene transfer vectors consisting of plasmid DNA packaged into virus-like particles (VLPs) with different cell tropisms. For this purpose, we have fused the N-terminally truncated VP60 capsid protein of the rabbit hemorrhagic disease virus (RHDV) with sequences which are expected to be sufficient to confer DNA packaging and gene transfer properties to the chimeric VLPs. Each of the two putative DNA-binding sequences of major L1 and minor L2 capsid proteins of human papillomavirus type 16 (HPV-16) were fused at the N terminus of the truncated VP60 protein. The two recombinant chimeric proteins expressed in insect cells self-assembled into VLPs similar in size and appearance to authentic RHDV virions. The chimeric proteins had acquired the ability to bind DNA. The two chimeric VLPs were therefore able to package plasmid DNA. However, only the chimeric VLPs containing the DNA packaging signal of the L1 protein were able efficiently to transfer genes into Cos-7 cells at a rate similar to that observed with papillomavirus L1 VLPs. It was possible to transfect only a very limited number of RK13 rabbit cells with the chimeric RHDV capsids containing the L2-binding sequence. The chimeric RHDV capsids containing the L1-binding sequence transfer genes into rabbit and hare cells at a higher rate than do HPV-16 L1 VLPs. However, no gene transfer was observed in human cell lines. The findings of this study demonstrate that the insertion of a DNA packaging sequence into a VLP which is not able to encapsidate DNA transforms this capsid into an artificial virus that could be used as a gene transfer vector. This possibility opens the way to designing new vectors with different cell tropisms by inserting such DNA packaging sequences into the major capsid proteins of other viruses.