| 1. |
- Skovbjerg, Susann, 1973, et al.
(författare)
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High cytokine levels in perforated acute otitis media exudates containing live bacteria
- 2010
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Ingår i: Clinical microbiology and infection. - : Elsevier BV. - 1469-0691 .- 1198-743X. ; 16:9, s. 1382-1388
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Tidskriftsartikel (refereegranskat)abstract
- Acute otitis media (AOM) is an inflammatory response to microbes in the middle ear, sometimes associated with rupture of the tympanic membrane. Human leukocytes produce different patterns of inflammatory mediators in vitro when stimulated with Gram-positive and Gram-negative bacteria, respectively. Here, we investigated the cytokine and prostaglandin E(2) (PGE(2)) responses in middle ear fluids (MEFs) from children with spontaneous perforated AOM and related the levels to the presence of pathogens detected by culture (live) or PCR (live or dead). Furthermore, in vivo cytokine pattern was compared with that induced in leukocytes stimulated by dead bacteria in vitro. MEFs with culturable pathogenic bacteria contained more IL-1beta (median 110 vs <7.5 ng/ml), TNF (6.3 vs <2.5 ng/ml), IL-8 (410 vs 38 ng/ml), and IL-10 (0.48 vs <0.30 ng/ml), than culture negative fluids, irrespective of PCR findings. IL-6 and PGE(2) were equally abundant (69-110 ng/ml) in effusions with live, dead or undetectable bacteria. Cytokine levels were unrelated to bacterial species and to the presence or absence of virus. Similar levels of TNF and IL-6 as found in the MEFs were obtained by in vitro stimulation of leukocytes, while 11x more IL-1beta and 3.5x more IL-8 was produced in vivo, and 22x more IL-10 was produced in vitro. A vigorous production of pro-inflammatory cytokines accompany AOM with membrane rupture regardless of causative agent, but the production seems to cease rapidly once the bacteria are killed and fragmented. IL-6 and PGE(2), however, remain after bacterial disintegration and may play a role in the resolution phase.
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| 2. |
- Adamiak, Beata, et al.
(författare)
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Human antibodies to herpes simplex virus type 1 glycoprotein C are neutralizing and target the heparan sulfate-binding domain
- 2010
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Ingår i: Virology. - : Elsevier BV. - 0042-6822. ; 400:2, s. 197-206
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Tidskriftsartikel (refereegranskat)abstract
- Human antibodies specific for glycoprotein C (gC1) of herpes simplex virus type 1 (HSV-1) neutralized the virus infectivity and efficiently inhibited attachment of HSV-1 to human HaCaT keratinocytes and to murine mutant L cells expressing either heparan sulfate or chondroitin sulfate at the cell surface. Similar activities were observed with anti-gC1 monoclonal antibody B1C1. In addition to HaCaT and L cells, B1C1 antibody neutralized HSV-1 infectivity in simian GMK AH1 cells mildly pre-treated with heparinase III. Human anti-gC1 antibodies efficiently competed with the binding of gC1 to B1C1 antibody whose epitope overlaps a part of the attachment domain of gC1. Human anti-gC1 and B1C1 antibodies extended survival time of mice experimentally infected with HSV-1. We conclude that in HaCaT cells and in cell systems showing restricted expression of glycosaminoglycans, human and some monoclonal anti-gC1 antibodies can target the cell-binding domain of this protein and neutralize viral infectivity.
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| 3. |
- Andersson, E. M., et al.
(författare)
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Comparison of the FilmArray assay and in-house real-time PCR for detection of respiratory infection
- 2014
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 46:12, s. 897-901
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Tidskriftsartikel (refereegranskat)abstract
- Recently, molecular methods capable of detecting almost all microbial agents that may cause acute respiratory infection have been introduced. The FilmArray Respiratory Panel assay, which integrates nucleic acid extraction, nested amplification and detection in a reaction pouch preloaded with all reagents required for detection of 17 viruses and 3 bacteria, was compared with an in-house real-time PCR that detects these agents in 8 parallel amplifications. When 128 clinical samples representing 18 of these agents were analysed by both assays the agreement was excellent, with kappa values ranging between 0.54 and 1.0. Discordances were mainly observed for adenovirus, but not when version 1.7 of FilmArray was used. The results show that these assays detect a wide range of pathogens with similar performance. FilmArray provides results after approximately 1 h, including approximate to 5 min hands-on time, and does not require advanced equipment or expertise in molecular diagnostics, making it a useful point-of-care-test for acute respiratory infections.
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| 4. |
- Brittain-Long, Robin, 1969, et al.
(författare)
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Access to a polymerase chain reaction assay method targeting 13 respiratory viruses can reduce antibiotics: a randomised, controlled trial.
- 2011
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Ingår i: BMC medicine. - : Springer Science and Business Media LLC. - 1741-7015. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Viral respiratory infections are common worldwide and range from completely benign disease to life-threatening illness. Symptoms can be unspecific, and an etiologic diagnosis is rarely established because of a lack of suitable diagnostic tools. Improper use of antibiotics is common in this setting, which is detrimental in light of the development of bacterial resistance. It has been suggested that the use of diagnostic tests could reduce antibiotic prescription rates. The objective of this study was to evaluate whether access to a multiplex polymerase chain reaction (PCR) assay panel for etiologic diagnosis of acute respiratory tract infections (ARTIs) would have an impact on antibiotic prescription rate in primary care clinical settings. METHODS: Adult patients with symptoms of ARTI were prospectively included. Nasopharyngeal and throat swabs were analysed by using a multiplex real-time PCR method targeting thirteen viruses and two bacteria. Patients were recruited at 12 outpatient units from October 2006 through April 2009, and samples were collected on the day of inclusion (initial visit) and after 10 days (follow-up visit). Patients were randomised in an open-label treatment protocol to receive a rapid or delayed result (on the following day or after eight to twelve days). The primary outcome measure was the antibiotic prescription rate at the initial visit, and the secondary outcome was the total antibiotic prescription rate during the study period. RESULTS: A total sample of 447 patients was randomised. Forty-one were excluded, leaving 406 patients for analysis. In the group of patients randomised for a rapid result, 4.5% (9 of 202) of patients received antibiotics at the initial visit, compared to 12.3% (25 of 204) (P = 0.005) of patients in the delayed result group. At follow-up, there was no significant difference between the groups: 13.9% (28 of 202) in the rapid result group and 17.2% (35 of 204) in the delayed result group (P = 0.359), respectively. CONCLUSIONS: Access to a rapid method for etiologic diagnosis of ARTIs may reduce antibiotic prescription rates at the initial visit in an outpatient setting. To sustain this effect, however, it seems necessary to better define how to follow and manage the patient according to the result of the test, which warrants further investigation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01133782.
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| 5. |
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| 6. |
- Brittain-Long, Robin, 1969, et al.
(författare)
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Seasonal variations of 15 respiratory agents illustrated by the application of a multiplex polymerase chain reaction assay.
- 2011
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Ingår i: Scandinavian journal of infectious diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548.
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: Nucleic acid amplification tests are increasingly being used to diagnose viral and bacterial respiratory tract infections. The high sensitivity of these tests affects our understanding of the epidemiology of respiratory tract infections. We have assessed the detection rate of a multiplex real-time polymerase chain reaction (PCR) test, with emphasis on epidemiology and seasonal distribution of the most common respiratory tract infections. Methods: Seven thousand eight hundred and fifty-three nasopharyngeal samples from 7220 patients (age range 0-98 y, median 22 y) obtained during 36 consecutive months (November 2006-October 2009), were analyzed with a multiplex PCR panel including influenza A (IfA) and B (IfB) virus, parainfluenza virus (PIV) 1-3, respiratory syncytial virus (RSV), human rhinovirus (HRV), human coronavirus (CoV) OC43, NL63, and 229E, human metapneumovirus (HMPV), adenovirus (AdV), enterovirus (EV), and 2 bacteria - Mycoplasma pneumoniae and Chlamydophila pneumoniae. Results: Of the total samples, 44.5% (n = 3496) were positive for at least 1 agent, with HRV being the most common (n = 1482, 38.0%), followed by RSV (n = 526, 13.5%) and IfA (n = 403, 10.3%). The diagnostic yield was significantly higher during the winter and early spring compared to the summer (n = 2439 of 4458 samples, 54.7% and n = 1057 of 3395 samples, 31.1%, respectively; p < 0.001). Conclusions: The diagnostic yield was highly dependent on the month of sampling and the age of the patient. However, the overall detection rate per month was above 30%, apart for August and September. Our findings support the use of similar tests in routine clinical care all year round. HRV was the most common finding in the respiratory tract, independent of season.
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| 7. |
- Clo, E., et al.
(författare)
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Characterization of the Viral O-Glycopeptidome: a Novel Tool of Relevance for Vaccine Design and Serodiagnosis
- 2012
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Ingår i: Journal of Virology. - : American Society for Microbiology. - 0022-538X .- 1098-5514. ; 86:11, s. 6268-6278
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Tidskriftsartikel (refereegranskat)abstract
- Viral envelope proteins mediate interactions with host cells, leading to internalization and intracellular propagation. Envelope proteins are glycosylated and are known to serve important functions in masking host immunity to viral glycoproteins. However, the viral infectious cycle in cells may also lead to aberrant glycosylation that may elicit immunity. Our knowledge of immunity to aberrant viral glycans and glycoproteins is limited, potentially due to technical limitations in identifying immunogenic glycans and glycopeptide epitopes. This work describes three different complementary methods for high-throughput screening and identification of potential immunodominant O-glycopeptide epitopes on viral envelope glycoproteins: (i) on-chip enzymatic glycosylation of scan peptides, (ii) chemical glycopeptide microarray synthesis, and (iii) a one-bead-one-compound random glycopeptide library. We used herpes simplex virus type 2 (HSV-2) as a model system and identified a simple O-glycopeptide pan-epitope, (501)PPA(GalNAc)TAPG(507), on the mature gG-2 glycoprotein that was broadly recognized by IgG antibodies in HSV-2-infected individuals but not in HSV-1-infected or noninfected individuals. Serum reactivity to the extended sialyl-T glycoform was tolerated, suggesting that self glycans can participate in immune responses. The methods presented provide new insight into viral immunity and new targets for immunodiagnostic and therapeutic measures.
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| 8. |
- D'Arrigo, I., et al.
(författare)
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Diverse IgG serum response to novel glycopeptide epitopes detected within immunodominant stretches of Epstein-Barr virus glycoprotein 350/220: diagnostic potential of O-glycopeptide microarrays
- 2013
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Ingår i: Glycoconjugate Journal. - : Springer Science and Business Media LLC. - 0282-0080 .- 1573-4986. ; 30:7, s. 633-640
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Tidskriftsartikel (refereegranskat)abstract
- The Epstein-Barr virus (EBV) envelope glycoprotein 350/220 (gp350/220) is the most abundant molecule on the viral surface and it is responsible for the initial viral attachment to cell surface of the host. As many other viral envelope proteins, it is highly glycosylated, not least with O-linked glycans, most of which essential for EBV life cycle. EBV gp350/220 is also a primary target for neutralizing antibodies in the human hosts and a promising candidate for an EBV vaccine. Here we showed that recombinant GalNAc transferases can glycosylate scan peptides of the EBV gp350/220 envelope protein immobilized on microarray glass slides. We also identified serum IgG antibodies to a selection of peptides and O-glycopeptides, whereas sera from EBV-IgG negative individuals remained negative. We here describe novel glycopeptide epitopes present within immunodominant stretches of EBV gp350/220 and demonstrate a remarkable variability between individual samples with respect to their reactivity patterns to peptides and glycopeptides. The study provides additional insights into the complex B-cell response towards the EBV gp350/220 envelope protein, which may have implications for diagnostic and vaccine developments.
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| 9. |
- Nasir, Waqas, et al.
(författare)
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Parvovirus B19 VLP recognizes globoside in supported lipid bilayers
- 2014
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Ingår i: Virology. - : Elsevier BV. - 0042-6822 .- 1096-0341. ; 456, s. 364-369
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Tidskriftsartikel (refereegranskat)abstract
- Studies have suggested that the glycosphingolipid globoside (Gb4Cer) is a receptor for human parvovirus B19. Virus-like particles bind to Gb4Cer on thin-layer chromatograms, but a direct interaction between the virus and lipid membrane-associated Gb4Cer has been debated. Here, we characterized the binding of parvovirus B19 VP1/VP2 virus-like particles to glycosphingolipids (i) on thin-layer chromatograms (TLCs) and (ii) incorporated into supported lipid bilayers (SLBs) acting as cell-membrane mimics. The binding specificities of parvovirus B19 determined in the two systems were in good agreement; the VLP recognized both Gb4Cer and the Forssman glycosphingolipid on TLCs and in SLBs compatible with the role of Gb4Cer as a receptor for this virus.
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| 10. |
- Nordén, Rickard, 1977, et al.
(författare)
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Inhibition of protein deacetylation augments herpes simplex virus type 1-activated transcription of host fucosyltransferase genes associated with virus-induced sLex expression.
- 2010
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Ingår i: Archives of virology. - : Springer Science and Business Media LLC. - 1432-8798 .- 0304-8608. ; 155:3, s. 305-13
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 induces expression of the selectin ligand sialyl Lewis X in infected cells by activating transcription of three normally silent host glycosyltransferase genes, FUT3, FUT5, and FUT6, a process that is initiated by binding of viral RNA to cellular protein kinase R. We investigated the involvement of protein deacetylation and promoter methylation in viral activation of host FUT genes by analysing the effects of appropriate inhibitors on the transcription rates of the FUT genes in virus-infected cells. The histone deacetylase inhibitor trichostatin A augmented the viral activation of FUT transcription, whereas inhibition of DNA methylation did not affect transcription of these genes. The trichostatin A enhancement did not involve interference with expression of viral late genes or viral DNA replication. Thus, the virus-activated FUT genes are at least partially suppressed by deacetylation of histones or other regulatory proteins in uninfected HEL cells, whereas promoter methylation is a less important factor.
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