bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased Specificity of an Assay for Recent Infection in HIV-1-Infected Patients on Highly Active Antiretroviral Treatment: Implications for Incidence Estimates
Authors: Chaillon Antoine , Le Vu Stéphane , Brunet Sylvie , Gras Guillaume , Bastides Frédéric , Bernard Louis , Meyer Laurence , Barin Francis 
Published: June 2012

ABSTRACTThe aim of this study was to estimate the rate of misclassification in treated HIV patients who initiated treatment at the chronic stage of HIV infection using an enzyme immunoassay (EIA) that discriminates between recent infection (RI; within 6 months) and established infection. The performance of EIA-RI was evaluated in 96 HIV-1 chronically infected patients on highly active antiretroviral therapy (HAART) with an undetectable viral load (VL) for at least 3 years. Demographic data, HIV-1 viral load, CD4+T-cell count, viral subtype, and treatment duration were collected. The subset of misclassified patients was further analyzed using samples collected annually. The impact on incidence estimates was evaluated by simulation. The specificity in treated patients was significantly lower (70.8 to 77.1%) than that observed in untreated patients (93.3 to 99.3%,P< 0.001). Patients falsely classified as recently infected had been treated for a longer period and had longer-term viral suppression than those correctly classified. The loss of specificity of the test due to treatment may have a dramatic impact on the accuracy of the incidence estimates, with a major impact when HIV prevalence is high. The cross-sectional studies intended to derive HIV incidence must collect information on treatment or, alternatively, should include detection of antiretroviral drugs in blood specimens to rule out treated patients from the calculations.
Molecular Characterization and Panton-Valentine Leucocidin Typing of Community-Acquired Methicillin-Sensitive Staphylococcus aureus Clinical Isolates
Authors: Otokunefor Kome , Sloan Tim , Kearns Angela M. , James Richard 
Published: June 2012

ABSTRACT

Limited comprehensive molecular typing data exist currently for Panton-Valentine leucocidin (PVL)-positive, methicillin-sensitive
Staphylococcus aureus
(PVL-MSSA) clinical isolates. Characterization of PVL-MSSA isolates by multilocus sequence typing (MLST) and
spa
typing in this study showed a genetic similarity to PVL-positive, methicillin-resistant
S. aureus
(PVL-MRSA) strains, although three novel
spa
types and a novel MLST (ST1518) were detected. Furthermore, the detection of PVL phages and haplotypes in PVL-MSSA identical to those previously found in PVL-MRSA isolates highlights the role these strains may play as precursors of emerging lineages of clinical significance.
Epidural Abscess Caused by Streptobacillus moniliformis
Authors: Addidle Michael , Pynn Joanne , Grimwade Kate , Giola Massimo 
Published: June 2012

ABSTRACT

We present an interesting case of a patient who developed an epidural abscess caused by
Streptobacillus moniliformis
. This is the first report in the medical literature of a spinal epidural abscess associated with this organism. Diagnosis of
S. moniliformis
infection requires a high degree of suspicion, and a delay may be inevitable when a relevant clinical history is lacking.
Detection of Extended-Spectrum β-Lactamase and Klebsiella pneumoniae Carbapenemase Genes Directly from Blood Cultures by Use of a Nucleic Acid Microarray
Authors: Fishbain Joel T. , Sinyavskiy Oleg , Riederer Kathleen , Hujer Andrea M. , Bonomo Robert A. 
Published: June 2012

ABSTRACT

The growing crisis of multidrug-resistant (MDR) Gram-negative bacteria requires that current technologies permit the rapid detection of extended-spectrum β-lactamase (
bla
ESBL
) and
Klebsiella pneumoniae
carbapenemase (
bla
KPC
) genes. In the present study, we assessed the performance characteristics of a commercially available nucleic acid microarray system for the detection of
bla
ESBL
and
bla
KPC
genes directly from positive blood cultures. Using blood cultures (BCs) that contained Gram-negative bacilli identified by Gram staining, we isolated bacterial DNA using spin columns (BC-C) and rapid water lysis (BC-W). Twenty ESBL/KPC-positive and 20 ESBL/KPC-negative blood culture samples, as well as 20 non-lactose-fermenting organisms, were tested. The 20 isolates that were ESBL positive by phenotypic testing were also evaluated on solid medium (SM), and the DNA was extracted by use of a spin column (SM-C). The resulting 140 DNA extractions were assessed for DNA quantity and quality using 260/280-nm absorbance ratios, and DNA microarray analysis was performed in a blinded fashion. Microarray and phenotypic results were concordant for 98.3% of BC-W, 90% of BC-C, and 95% of SM-C samples. Compared to phenotypic testing, the sensitivity and specificity for BC-C samples were 88.9% and 100%, respectively, and for BC-W samples, the sensitivity and specificity were 94.4% and 100%, respectively. BC-W samples yielded the highest concordance with phenotypic results. Nucleic acid microarrays offer promise in the identification of
bla
ESBL
and
bla
KPC
genes directly from blood cultures, thereby reducing the time to identification of these important pathogens.
Effect of Manganese in Test Media on
In Vitro
Susceptibility of Enterobacteriaceae and Acinetobacter baumannii to Tigecycline
Authors: Veenemans J. , Mouton J. W. , Kluytmans J. A. J. W. , Donnely R. , Verhulst C. , van Keulen P. H. J. 
Published: June 2012

ABSTRACT
We assessed the effect of increasing manganese concentrations in test media (0.001 to 1,024 mg/liter) on MICs of tigecycline. For both broth microdilution (BMD) and Etests, this effect was negligible for physiological concentrations, but MICs increased when concentrations exceeded 8 mg/liter. Susceptibility testing should be performed on media with standardized low manganese content.
Zoonotic Parasites of Bobcats around Human Landscapes
Authors: Carver Scott , Scorza Andrea V. , Bevins Sarah N. , Riley Seth P. D. , Crooks Kevin R. , VandeWoude Sue , Lappin Michael R. 
Published: June 2012

ABSTRACT

We analyzed
Lynx rufus
fecal parasites from California and Colorado, hypothesizing that bobcats shed zoonotic parasites around human landscapes.
Giardia duodenalis
,
Cryptosporidium
,
Ancylostoma
,
Uncinaria
, and
Toxocara cati
were shed.
Toxoplasma gondii
serology demonstrated exposure.
Giardia
and
Cryptosporidium
shedding increased near large human populations. Genotyped
Giardia
may indicate indirect transmission with humans.
Roles of Cell Signaling Pathways in Cell-to-Cell Contact-Mediated Epstein-Barr Virus Transmission
Authors: Nanbo Asuka , Terada Haruna , Kachi Kunihiro , Takada Kenzo , Matsuda Tadashi 
Published: June 2012

ABSTRACT

Epstein-Barr virus (EBV), a human gamma herpesvirus, establishes a life-long latent infection in B lymphocytes and epithelial cells following primary infection. Several lines of evidence indicate that the efficiency of EBV infection in epithelial cells is accelerated up to 10
4
-fold by coculturing with EBV-infected Burkitt's lymphoma (BL) cells compared to infection with cell-free virions, indicating that EBV infection into epithelial cells is mainly mediated via cell-to-cell contact. However, the molecular mechanisms involved in this pathway are poorly understood. Here, we establish a novel assay to assess cell-to-cell contact-mediated EBV transmission by coculturing an EBV-infected BL cell line with an EBV-negative epithelial cell line under stimulation for lytic cycle induction. By using this assay, we confirmed that EBV was transmitted from BL cells to epithelial cells via cell-to-cell contact but not via cell-to-cell fusion. The inhibitor treatments of extracellular signal-regulated kinase (ERK) and nuclear factor (NF)-κB pathways blocked EBV transmission in addition to lytic induction. The blockage of the phosphoinositide 3-kinase (PI3K) pathway impaired EBV transmission coupled with the inhibition of lytic induction. Knockdown of the RelA/p65 subunit of NF-κB reduced viral transmission. Moreover, these signaling pathways were activated in cocultured BL cells and in epithelial cells. Finally, we observed that viral replication was induced in cocultured BL cells. Taken together, our data suggest that cell-to-cell contact induces multiple cell signaling pathways in BL cells and epithelial cells, contributing to the induction of the viral lytic cycle in BL cells and the enhancement of viral transmission to epithelial cells.
Characterization of the Early Steps of Human Parvovirus B19 Infection
Authors: Quattrocchi Silva , Ruprecht Nico , Bönsch Claudia , Bieli Sven , Zürcher Christoph , Boller Klaus , Kempf Christoph , Ros Carlos 
Published: June 2012

ABSTRACT

The early steps of human parvovirus B19 (B19V) infection were investigated in UT7/Epo cells. B19V and its receptor globoside (Gb4Cer) associate with lipid rafts, predominantly of the noncaveolar type. Pharmacological disruption of the lipid rafts inhibited infection when the drug was added prior to virus attachment but not after virus uptake. B19V is internalized by clathrin-dependent endocytosis and spreads rapidly throughout the endocytic pathway, reaching the lysosomal compartment within minutes, where a substantial proportion is degraded. B19V did not permeabilize the endocytic vesicles, indicating a mechanism of endosomal escape without apparent membrane damage. Bafilomycin A
1
(BafA1) and NH
4
Cl, which raise endosomal pH, blocked the infection by preventing endosomal escape, resulting in a massive accumulation of capsids in the lysosomes. In contrast, in the presence of chloroquine (CQ), the transfer of incoming viruses from late endosomes to lysosomes was prevented; the viral DNA was not degraded; and the infection was boosted. In contrast to the findings for untreated or BafA1-treated cells, the viral DNA was progressively associated with the nucleus in CQ-treated cells, reaching a plateau by 3 h postinternalization, a time coinciding with the initiation of viral transcription. At this time, more than half of the total intracellular viral DNA was associated with the nucleus; however, the capsids remained extranuclear. Our studies provide the first insight into the early steps of B19V infection and reveal mechanisms involved in virus uptake, endocytic trafficking, and nuclear penetration.
Viral-Load-Dependent Effects of Liver Injury and Regeneration on Hepatitis B Virus Replication in Mice
Authors: Tian Yongjun , Chen Wen-ling , Kuo Cheng-fu , Ou Jing-hsiung James 
Published: June 2012

ABSTRACT
Hepatitis B virus (HBV) is a hepatotropic virus that can cause severe liver diseases. By conducting studies using four different transgenic mouse lines that carry either the wild-type HBV genome or the HBV genome incapable of expressing the X gene, we found that liver injury and regeneration induced by a partial hepatectomy (PHx) could have different effects on HBV replication depending on the mouse lines. Further studies using hydrodynamic injection to introduce different amounts of the HBV genomic DNA into the mouse liver revealed that liver injury and regeneration induced by PHx enhanced HBV replication when viral load was low and suppressed HBV replication when viral load was high. These effects of liver injury and regeneration on HBV were independent of the HBV X protein and apparently due to alpha and beta interferons (IFN-α/β), as the effects could be abolished by the injection of anti-IFN-α/β antibodies. Further analysis indicated that PHx could induce the expression of hepatocyte nuclear factor 3 gamma (HNF3γ) when viral load was low and activate the signal transducer and activator of transcription 3 (Stat3) and suppress the expression of the suppressor of cytokine signaling 3 (SOCS3) irrespective of viral load. As both HNF3γ and Stat3 are required to activate the HBV enhancer I to stimulate HBV gene expression and replication, these results provided an explanation to the viral-load-dependent effect of liver injury and regeneration on HBV replication. Our studies thus revealed a novel interaction between HBV and its host and provided important information for understanding HBV replication and pathogenesis during liver injury.
Impact on the Endoplasmic Reticulum and Golgi Apparatus of Turnip Mosaic Virus Infection
Authors: Grangeon Romain , Agbeci Maxime , Chen Jun , Grondin Gilles , Zheng Huanquan , Laliberté Jean-François 
Published: June 2012

ABSTRACT

The impact of turnip mosaic virus (TuMV) infection on the endomembranes of the host early secretory pathway was investigated using an infectious clone that has been engineered for tagging viral membrane structures with a fluorescent protein fused to the viral protein 6K
2
. TuMV infection led to the amalgamation of the endoplasmic reticulum (ER), Golgi apparatus, COPII coatamers, and chloroplasts into a perinuclear globular structure that also contained viral proteins. One consequence of TuMV infection was that protein secretion was blocked at the ER-Golgi interface. Fluorescence recovery after photobleaching (FRAP) experiments indicated that the perinuclear structure cannot be restocked in viral components but was dynamically connected to the bulk of the Golgi apparatus and the ER. Experiments with 6K
2
fused to photoactivable green fluorescent protein (GFP) showed that production of motile peripheral 6K
2
vesicles was functionally linked to the perinuclear structure. Disruption of the early secretory pathway did not prevent the formation of the perinuclear globular structure, enhanced the clustering of peripheral 6K
2
vesicles with COPII coatamers, and led to inhibition of cell-to-cell virus movement. This suggests that a functional secretory pathway is not required for the formation of the TuMV perinuclear globular structure and peripheral vesicles but is needed for successful viral intercellular propagation.
Characterization
In Vitro
and
In Vivo
of Pandemic (H1N1) 2009 Influenza Viruses Isolated from Patients
Authors: Watanabe Tokiko , Imai Masaki , Watanabe Shinji , Shinya Kyoko , Hatta Masato , Li Chengjun , Neumann Gabriele , Ozawa Makoto , Hanson Anthony , Zhong Gongxun , Fukuyama Satoshi , Kawakami Eiryo , Simmons Heather A. , Schenkman Daniel , Brunner Kevin , Capuano Saverio V. , Weinfurter Jason T. , Kilander Anette , Dudman Susanne G. , Suresh M. , Hungnes Olav , Friedrich Thomas C. , Kawaoka Yoshihiro 
Published: June 2012

ABSTRACT
The first influenza pandemic of the 21st century was caused by novel H1N1 viruses that emerged in early 2009. Molecular evolutionary analyses of the 2009 pandemic influenza A H1N1 [A(H1N1)pdm09] virus revealed two major clusters, cluster I and cluster II. Although the pathogenicity of viruses belonging to cluster I, which became extinct by the end of 2009, has been examined in a nonhuman primate model, the pathogenic potential of viruses belonging to cluster II, which has spread more widely in the world, has not been studied in this animal model. Here, we characterized two Norwegian isolates belonging to cluster II, namely, A/Norway/3568/2009 (Norway3568) and A/Norway/3487-2/2009 (Norway3487), which caused distinct clinical symptoms, despite their genetic similarity. We observed more efficient replication in cultured cells and delayed virus clearance from ferret respiratory organs for Norway3487 virus, which was isolated from a severe case, compared with the efficiency of replication and time of clearance of Norway3568 virus, which was isolated from a mild case. Moreover, Norway3487 virus to some extent caused more severe lung damage in nonhuman primates than did Norway3568 virus. Our data suggest that the distinct replicative and pathogenic potentials of these two viruses may result from differences in their biological properties (e.g., the receptor-binding specificity of hemagglutinin and viral polymerase activity).
A Human CD4+T Cell Epitope in the Influenza Hemagglutinin Is Cross-Reactive to Influenza A Virus Subtypes and to Influenza B Virus
Authors: Babon Jenny Aurielle B. , Cruz John , Ennis Francis A. , Yin Liusong , Terajima Masanori 
Published: June 2012

ABSTRACTThe hemagglutinin protein (HA) of the influenza virus family is a major antigen for protective immunity. Thus, it is a relevant target for developing vaccines. Here, we describe a human CD4+T cell epitope in the influenza virus HA that lies in the fusion peptide of the HA. This epitope is well conserved in all 16 subtypes of the HA protein of influenza A virus and the HA protein of influenza B virus. By stimulating peripheral blood mononuclear cells (PBMCs) from a healthy adult donor with peptides covering the entire HA protein based on the sequence of A/Japan/305/1957 (H2N2), we generated a T cell line specific to this epitope. This CD4+T cell line recognizes target cells infected with influenza A virus seasonal H1N1 and H3N2 strains, a reassortant H2N1 strain, the 2009 pandemic H1N1 strain, and influenza B virus in cytotoxicity assays and intracellular-cytokine-staining assays. It also lysed target cells infected with avian H5N1 virus. We screened healthy adult PBMCs for T cell responses specific to this epitope and found individuals who hadex vivogamma interferon (IFN-γ) responses to the peptide epitope in enzyme-linked immunospot (ELISPOT) assays. Almost all donors who responded to the epitope had the HLA-DRB1*09 allele, a relatively common HLA allele. Although natural infection or standard vaccination may not induce strong T and B cell responses to this highly conserved epitope in the fusion peptide, it may be possible to develop a vaccination strategy to induce these CD4+T cells, which are cross-reactive to both influenza A and B viruses.
Predictors of duodenal bulb biopsy performance in the evaluation of coeliac disease in children
Authors: Tanpowpong Pornthep , Broder-Fingert Sarabeth , Katz Aubrey J , Camargo Carlos A 
Published: June 2012

AimsStudies on the role of duodenal bulb biopsy (DBB) in coeliac disease (CD) evaluation have increased in recent years; growing evidence suggests that the disease can present solely in the duodenal bulb. Moreover, recent CD guidelines recommend obtaining a DBB. The study aim was to examine DBB performance in children undergoing CD evaluation and to identify independent predictors of DBB performance.MethodsThe authors performed a structured chart review of children aged <18 years who underwent CD evaluation between 2000 and 2010 at a large teaching hospital. The authors collected data including demographics, serology, endoscopy and histopathological findings. Predictors of DBB performance (obtained vs not obtained) were determined using multivariable logistic regression.ResultsAmong 616 children who underwent endoscopy, DBB was performed in 103 children (17%, 95% CI 14% to 20%) with an increasing trend in the more recent years (2008–2010, 25%; 2004–2007, 16%; and 2000–2003, 5%, p<0.001). Three independent predictors of DBB performance were older age at endoscopy (OR 1.05 per year of age), gross gastric antral abnormalities (OR 2.81) and gross duodenal abnormalities (OR 5.55). Regarding the DBB histological findings, patchiness of CD was found in 15%. Positive Marsh III biopsy presented solely on the DBB in 6/103 (6%, 95% CI 2% to 12%) children.ConclusionsThe authors found a significant increase in DBB performance over time, but the overall performance remains suboptimal. Improving education on obtaining a DBB for CD evaluation is crucial, especially among those children in whom DBB is more likely to be omitted.
Reconstructive endovascular treatment of a ruptured vertebral artery dissecting aneurysm using the Pipeline embolization device
Authors: Ducruet Andrew F , Crowley R Webster , Albuquerque Felipe C , McDougall Cameron G 
Published: June 2012

BackgroundThe Pipeline embolization device has been used successfully to treat intracranial aneurysms with difficult morphologies. However, the need for dual antiplatelet therapy has limited its use after subarachnoid hemorrhage.Case reportA 42-year-old woman with a ruptured dissecting aneurysm of her dominant vertebral artery (V4) was successfully treated by Pipeline embolization with preservation of flow through a covered posterior inferior cerebellar artery. This strategy preserved endovascular access for the treatment of severe posterior circulation vasospasm. She was a non-responder to thienopyridine agents and was thus maintained on aspirin and heparin, which was transitioned to warfarin following ventricular drain removal. The aneurysm remains angiographically obliterated at 6 months. Despite a moribund presentation and an extended hospitalization, she has made a remarkable neurological recovery.ConclusionsPipeline embolization may be used to treat a ruptured dissecting aneurysm in selected cases where parent vessel preservation is paramount.
Maximising the potential of voluntary counselling and testing for HIV: sexually transmitted infections and HIV epidemiology in a population testing for HIV and its implications for practice
Authors: Wu Hsiu , Wu Pei-Ying , Li Shu-Ying , Chang Sui-Yuan , Liu Wen-Chun , Wu Cheng-Hsin , Lo Yi-Cheng , Hsieh Chia-Yin , Sun Hsin-Yun , Hung Chien-Ching 
Published: June 2012

ObjectivesThis study aimed to describe the epidemiology of HIV infection and sexually transmitted infections (STIs) among persons who attended voluntary counselling and testing (VCT) service for HIV and to assess whether the VCT programme reached the right population at risk in Taiwan.MethodsFrom 2006 to 2010, questionnaire interview, integrated pretesting and post-testing counselling, followed by serological tests for HIV,Treponema pallidumandEntamoeba histolyticawere performed for all VCT clients; additional tests forChlamydia trachomatisandNeisseria gonorrhoeaeusing PCR assays of urine specimens were provided when the assays became available in two periods.ResultsDuring the study period, 10 198 VCT attendances occurred in 6863 clients, in whom 1685 (24.6%) had re-attendances. Male clients, men who have sex with men and clients with one-night stand and casual sexual partners were more likely to re-attend VCT service in the next 12 months. The overall STI prevalence was 3.5% for HIV infection, 2.2% syphilis, 1.0% amoebiasis, 4.7% chlamydia and 0.7% gonorrhoea. In logistic regression model, men who have sex with men were consistently independently associated with HIV infection, syphilis and amoebiasis. Among the repeaters, the incidence rate of HIV infection and syphilis was 3.4 and 1.6 per 100 person-years of follow-up, respectively. In Cox regression analysis, clients who used illicit non-injection recreational drugs and who practiced unprotected anal sex were at significantly higher risk of acquiring HIV infection and syphilis.ConclusionsWith higher rates of re-attendances and STIs, the VCT programme reached the population most at risk for HIV and STIs compared with other screening programmes in Taiwan. The potential of VCT programme can be maximised in the prevention and control of HIV infection and STIs by providing tests for more STIs and counselling to avoid use of recreational drugs and to promote safe sex.