bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decay-Accelerating Factor Binding Determines the Entry Route of Echovirus 11 in Polarized Epithelial Cells
Authors: Sobo Komla , Rubbia-Brandt Laura , Brown T. David K. , Stuart Amanda D. , McKee Thomas A. 
Published: September 2011

ABSTRACTThe interaction between echovirus 11 strain 207 (EV11-207) and decay-accelerating factor (DAF or CD55) at the apical surface of polarized Caco-2 cells results in rapid transport of the virus to tight junctions and in its subsequent uptake. A virus mutant (EV11-207R) which differs at 6 amino acids and whose affinity for DAF is apparently significantly lower remains at the apical surface, from where its uptake occurs. Binding of EV11-207 to DAF and its transport to tight junctions result in a loss of function of the junctions. In contrast, the mutant virus EV11-207R is not transferred to tight junctions, nor does it impair the integrity of these junctions. Cholesterol depletion from the apical membrane leads to DAF aggregation and, presumably, internalization and inhibits infection by EV11-207. However, infection by EV11-207R is significantly less sensitive to cholesterol depletion than infection by EV11-207, confirming the DAF requirement for EV11-207, but not EV11-207R, to infect cells. These data strongly indicate that in the case of infection of polarized epithelial cells by echovirus 11, DAF binding appears be a key determinant in the choice of entry pathway, at least in cell culture.
Immunotherapy of Murine Retrovirus-Induced Acquired Immunodeficiency by CD4 T Regulatory Cell Depletion and PD-1 Blockade
Authors: Li Wen , Green William R. 
Published: September 2011

ABSTRACTLP-BM5 retrovirus induces a complex disease featuring an acquired immunodeficiency syndrome termed murine AIDS (MAIDS) in susceptible strains of mice, such as C57BL/6 (B6). CD4 T helper effector cells are required for MAIDS induction and progression of viral pathogenesis. CD8 T cells are not needed for viral pathogenesis, but rather, are essential for protection from disease in resistant strains, such as BALB/c. We have discovered an immunodominant cytolytic T lymphocyte (CTL) epitope encoded in a previously unrecognized LP-BM5 retroviral alternative (+1 nucleotide [nt])gagtranslational open reading frame. CTLs specific for this crypticgagepitope are the basis of protection from LP-BM5-induced immunodeficiency in BALB/c mice, and the inability of B6 mice to mount an anti-gagCTL response appears critical to the initiation and progression of LP-BM5-induced MAIDS. However, uninfected B6 mice primed by LP-BM5-induced tumors can generate CTL responses to an LP-BM5 retrovirus infection-associated epitope(s) that is especially prevalent on such MAIDS tumor cells, indicating the potential to mount a protective CD8 T-cell response. Here, we utilized this LP-BM5 retrovirus-induced disease system to test whether modulation of normal immune down-regulatory mechanisms can alter retroviral pathogenesis. Thus, followingin vivodepletion of CD4 T regulatory (Treg) cells and/or selective interruption of PD-1 negative signaling in the CD8 T-cell compartment, retroviral pathogenesis was significantly decreased, with the combined treatment of CD4 Tregcell depletion and PD-1 blockade working in a synergistic fashion to substantially reduce the induction of MAIDS.
Proteinase K-Resistant Material in ARR/VRQ Sheep Brain Affected with Classical Scrapie Is Composed Mainly of VRQ Prion Protein
Authors: Jacobs J. G. , Bossers A. , Rezaei H. , van Keulen L. J. M. , McCutcheon S. , Sklaviadis T. , Lantier I. , Berthon P. , Lantier F. , van Zijderveld F. G. , Langeveld J. P. M. 
Published: September 2011

ABSTRACT

Classical scrapie is a prion disease in sheep and goats. In sheep, susceptibility to disease is genetically influenced by single amino acid substitutions. Genetic breeding programs aimed at enrichment of arginine-171 (171R) prion protein (PrP), the so-called ARR allele, in the sheep population have been demonstrated to be effective in reducing the occurrence of classical scrapie in the field. Understanding the molecular basis for this reduced prevalence would serve the assessment of ARR adaptation. The prion formation mechanism and conversion of PrP from the normal form (PrP
C
) to the scrapie-associated form (PrP
Sc
) could play a key role in this process. Therefore, we investigated whether the ARR allele substantially contributes to scrapie prion formation in naturally infected heterozygous 171Q/R animals. Two methods were applied to brain tissue of 171Q/R heterozygous sheep with natural scrapie to determine the relative amount of the 171R PrP fraction in PrP
res
, the proteinase K-resistant PrP
Sc
core. An antibody test differentiating between 171Q and 171R PrP fragments showed that PrP
res
was mostly composed of the 171Q allelotype. Furthermore, using a novel tool for prion research, endoproteinase Lys-C-digested PrP
res
yielded substantial amounts of a nonglycosylated and a monoglycosylated PrP fragment comprising codons 114 to 188. Following two-dimensional gel electrophoresis, only marginal amounts (<9%) of 171R PrP
res
were detected. Enhanced 171R
res
proteolytic susceptibility could be excluded. Thus, these data support a nearly zero contribution of 171R PrP in PrP
res
of 171R/Q field scrapie-infected animals. This is suggestive of a poor adaptation of classical scrapie to this resistance allele under these natural conditions.
Cross-Species Analysis of the Replication Complex of Old World Arenaviruses Reveals Two Nucleoprotein Sites Involved in L Protein Function
Authors: Kerber Romy , Rieger Toni , Busch Carola , Flatz Lukas , Pinschewer Daniel D. , Kümmerer Beate M. , Günther Stephan 
Published: September 2011

ABSTRACT
Lassa virus (LASV) causing hemorrhagic Lassa fever in West Africa, Mopeia virus (MOPV) from East Africa, and lymphocytic choriomeningitis virus (LCMV) are the main representatives of the Old World arenaviruses. Little is known about how the components of the arenavirus replication machinery, i.e., the genome, nucleoprotein (NP), and L protein, interact. In addition, it is unknown whether these components can function across species boundaries. We established minireplicon systems for MOPV and LCMV in analogy to the existing LASV system and exchanged the components among the three systems. The functional and physical integrity of the resulting complexes was tested by reporter gene assay, Northern blotting, and coimmunoprecipitation studies. The minigenomes, NPs, and L proteins of LASV and MOPV could be exchanged without loss of function. LASV and MOPV L protein was also active in conjunction with LCMV NP, while the LCMV L protein required homologous NP for activity. Analysis of LASV/LCMV NP chimeras identified a single LCMV-specific NP residue (Ile-53) and the C terminus of NP (residues 340 to 558) as being essential for LCMV L protein function. The defect of LASV and MOPV NP in supporting transcriptional activity of LCMV L protein was not caused by a defect in physical NP-L protein interaction. In conclusion, components of the replication complex of Old World arenaviruses have the potential to functionally and physically interact across species boundaries. Residue 53 and the C-terminal domain of NP are important for function of L protein during genome replication and transcription.
Gag Cytotoxic T Lymphocyte Escape Mutations Can Increase Sensitivity of HIV-1 to Human TRIM5α, Linking Intrinsic and Acquired Immunity
Authors: Battivelli Emilie , Migraine Julie , Lecossier Denise , Yeni Patrick , Clavel François , Hance Allan J. 
Published: September 2011

ABSTRACT
Although laboratory-adapted HIV-1 strains are largely resistant to the human restriction factor TRIM5α (hTRIM5α), we have recently shown that some viruses carrying capsid (CA) sequences from clinical isolates can be more sensitive to this restriction factor. In this study we evaluated the contribution to this phenotype of CA mutations known to be associated with escape from cytotoxic T lymphocyte (CTL) responses. Recombinant viruses carrying HIV-1 CA sequences from NL4-3 and three different clinical isolates were prepared, along with variants in which mutations associated with CTL resistance were modified by site-directed mutagenesis, and the infectivities of these viruses in target cells expressing hTRIM5α and cells in which TRIM5α activity had been inhibited by overexpression of TRIM5γ were compared. For both hTRIM5α-sensitive viruses studied, CTL-associated mutations were found to be responsible for this phenotype. Both CTL resistance mutations occurring within HLA-restricted CA epitopes and compensatory mutations occurring outside CTL epitopes influenced hTRIM5α sensitivity, and mutations associated with CTL resistance selected in prior hosts can contribute to this effect. The impact of CTL resistance mutations on hTRIM5α sensitivity was context dependent, because mutations shown to be responsible for the TRIM5α-sensitive phenotype in viruses from one patient could have little or no impact on this parameter when introduced into another virus. No fixed relationship between changes in hTRIM5α sensitivity and infectivity was discernible in our studies. Taken together, these findings suggest that CTL mutations may influence HIV-1 replication by modifying both viral infectivity and sensitivity to TRIM5α.
Increased Pathogenicity of a Reassortant 2009 Pandemic H1N1 Influenza Virus Containing an H5N1 Hemagglutinin
Authors: Cline Troy D. , Karlsson Erik A. , Freiden Pamela , Seufzer Bradley J. , Rehg Jerold E. , Webby Richard J. , Schultz-Cherry Stacey 
Published: September 2011

ABSTRACT

A novel H1N1 influenza virus emerged in 2009 (pH1N1) to become the first influenza pandemic of the 21st century. This virus is now cocirculating with highly pathogenic H5N1 avian influenza viruses in many parts of the world, raising concerns that a reassortment event may lead to highly pathogenic influenza strains with the capacity to infect humans more readily and cause severe disease. To investigate the virulence of pH1N1-H5N1 reassortant viruses, we created pH1N1 (A/California/04/2009) viruses expressing individual genes from an avian H5N1 influenza strain (A/Hong Kong/483/1997). Using several
in vitro
models of virus replication, we observed increased replication for a reassortant CA/09 virus expressing the hemagglutinin (HA) gene of HK/483 (CA/09-483HA) relative to that of either parental CA/09 virus or reassortant CA/09 expressing other HK/483 genes. This increased replication correlated with enhanced pathogenicity in infected mice similar to that of the parental HK/483 strain. The serial passage of the CA/09 parental virus and the CA/09-483HA virus through primary human lung epithelial cells resulted in increased pathogenicity, suggesting that these viruses easily adapt to humans and become more virulent. In contrast, serial passage attenuated the parental HK/483 virus
in vitro
and resulted in slightly reduced morbidity
in vivo
, suggesting that sustained replication in humans attenuates H5N1 avian influenza viruses. Taken together, these data suggest that reassortment between cocirculating human pH1N1 and avian H5N1 influenza strains will result in a virus with the potential for increased pathogenicity in mammals.
Major Histocompatibility Complex Class II Expression and Hemagglutinin Subtype Influence the Infectivity of Type A Influenza Virus for Respiratory Dendritic Cells
Authors: Hargadon Kristian M. , Zhou Haixia , Albrecht Randy A. , Dodd Haley A. , García-Sastre Adolfo , Braciale Thomas J. 
Published: September 2011

ABSTRACTDendritic cells (DC) play a key role in antiviral immunity, functioning both as innate effector cells in early phases of the immune response and subsequently as antigen-presenting cells that activate the adaptive immune response. In the murine respiratory tract, there are several respiratory dendritic cell (RDC) subsets, including CD103+DC, CD11bhiDC, monocyte/macrophage DC, and plasmacytoid DC. However, little is known about the interaction between these tissue-resident RDC and viruses that are encountered during natural infection in the respiratory tract. Here, we show bothin vitroandin vivothat the susceptibility of murine RDC to infection with type A influenza virus varies with the level of MHC class II expression by RDC and with the virus strain. Both CD103+and CD11bhiRDC, which express the highest basal level of major histocompatibility complex (MHC) class II, are highly susceptible to infection by type A influenza virus. However, efficient infection is restricted to type A influenza virus strains of the H2N2 subtype. Furthermore, enhanced infectivity by viruses of the H2N2 subtype is linked to expression of the I-E MHC class II locus product. These results suggest a potential novel role for MHC class II molecules in influenza virus infection and pathogenesis in the respiratory tract.
011 Pilot project evaluating HIV testing in St George's Emergency Department
Authors: Hempling M C , Pakianathan M , Majewska W , Shields K , Davey S , Karim J 
Published: September 2011

Objectives and BackgroundsWith the availability of highly active antiretroviral therapy, HIV is now very treatable. However, a third of those with HIV remain undiagnosed and the majority of deaths occurring in those with HIV are due to late diagnosis.AimsTo improve the detection rate of HIV early to offer people the opportunity to tackle the disease more effectively. To assess acceptability of the test to patients and staff within the ED.MethodsEligible patients were adults between 18 and 65 who attend the ED from 1 to 31 March 2011 having blood tests and able to consent. A trained member of staff obtained verbal consent. Patients were given an information leaflet and opportunity to ask questions. Testing was undertaken by laboratory staff and a telephone results line set up. Positive results were followed up by GUM staff. A survey was sent to the ED staff for further feedback.ResultsResults 2726 eligible patients had blood tests taken during the pilot period. 584 HIV tests were taken. Three new positives were diagnosed. In addition at least two patients with known HIV also attended during giving a prevalence of 0.85%. Over 50% of patients declined testing. The commonest reason was that they did not perceive that they were at risk. A minority were offended by being offered the test. The majority of staff responding to the survey were comfortable offering HIV testing (86%) and felt it appropriate to offer the test in the ED (81%).ConclusionsMost staff who answered the survey were happy to offer HIV testing. However, in many cases, the test was not offered or patients declined. Further training of the ED staff would be beneficial as we could have missed opportunities to pick up many more positives. Although three new diagnoses is a small number, this gives a prevalence that far exceeds the 2 in 1000 suggested by national HIV guidelines to make offering routine testing worthwhile. However, further cost analysis and assessment of overall impact on the ED would need to be done before we could continue to offer routine testing.
012 Retrospective analysis of cervical spine radiography in a tertiary head injury centre
Authors: Shafei R , Baneke A , Fink D , Costello J 
Published: September 2011

Objectives and BackgroundsThe EAST (Eastern Association for the Surgery of Trauma) guidelines define adequate radiography of the cervical spine. Previous studies looking at emergency department cervical spine radiographs have found a significant proportion to be inadequate. This study will ascertain the adequacy of cervical spine imaging on trauma patients in a major London tertiary referral centre. Local reporting of cervical spine radiographs are compared to the gold standard EAST guidelines.MethodsData were examined from 100 consecutive patients. We applied the EAST criteria retrospectively to all cervical spine radiology undertaken in this cohort of patients to define adequate or inadequate films. We assessed the performance of local radiology reporting.Results99% of patients undergoing a full trauma series had at least one inadequate initial image. Of these, 85% had at least one inadequate lateral or peg view. 74% with inadequate initial lateral or peg views had repeats performed. Only 23% of all inadequate initial and repeat lateral or peg views were explicitly reported as inadequate on the radiology report. In total 36% of all trauma patients left the emergency department with inadequate cervical spine imaging (no full trauma series or no repeat after an inadequate film).ConclusionsInadequate radiography of the cervical spine is common in trauma. Over one-third of trauma patients may not receive adequate imaging of their cervical spine; these findings suggest that there is significant process variability, which is compounded by the heterogamous population. We offer solutions.
014 Routine HIV testing in the Emergency Department: a tale of two trials: Abstract 014 Table 1
Authors: Finlay S , Rayment M , Rae C , Roberts P , Sullivan A 
Published: September 2011

Objectives and BackgroundsThe problem of undiagnosed HIV in the UK, resulting in preventable transmission rates, morbidity, mortality and cost, needs to be addressed. The HINTS (“HIV testing in Non-Traditional Settings”) trial showed that HIV testing in the ED is acceptable to patients and successful in identifying previously undiagnosed individuals. We aim to establish a model for sustainable HIV screening in the ED. HEDsUP (“HIV Testing in Emergency Departments: A Universal Offer Programme”) investigates ED-led delivery of testing within a network of four North West London EDs.MethodsWe implemented 24/7 doctor-delivered testing of all 16–65-year-old ED patients able to consent, as a part of routine care. Patient information leaflets were given and promotional material displayed. Salivary tests collected in the ED were processed in the local virology laboratory. Patients received results by text message (negative result) or telephone call if test reactive to arrange confirmatory serology. Local sexual health services organised all follow-up. ED and Sexual Health staff met weekly to review key outcome measures (number of eligible patients, numbers of tests offered and accepted). Sustainability methodology (real time run charts, statistical control methods, plan-do-study-act cycles) was used to modify processes in an iterative fashion.ResultsSee Abstract 014 table below. Marked weekly variation was noted in all key outcome measures. Plan-do-study-act cycles with notable positive impact included introduction of local champions, in-house teaching, and increased prominence of promotional material.Abstract 014 Table 1ResultsHINTSHEDsUP (wks 1–20)Eligible40707262Offered3469715Accepted2123 (61.2%)468 (65.5%)Sero-positivity4 (0.19%)1 (0.21%)ConclusionsHIV testing in EDs is feasible and remains acceptable (arguably more so) when doctor-delivered. Main challenges identified were expanding and maintaining provision across all shifts and all staff. An IT solution to prompt further testing is planned. Further work is underway to identify barriers to testing through focus groups and 1:1 interviews.
021 Non-standard practice of phlebotomy techniques: a significant cause of wasted samples and potential misleading results in Emergency Medicine
Authors: Berg J E , Berg J D , Ahee P 
Published: September 2011

Objectives and BackgroundsPhlebotomy is a potential cause of pre-analytical errors in the setting of a busy Emergency Department. We have studied current phlebotomy techniques in the Majors area comparing these to standard protocols that should be followed. We have looked at the incidence of haemolysed samples and compared this with that seen in the wider hospital.MethodsPhlebotomy episodes (n=50) were observed and compared to standard procedures. A computer based search of the number of haemolysed samples from Emergency Medicine and all hospital in-patients was reviewed.ResultsA total of 13 different types of Emergency Department staff were observed undertaking 50 phlebotomy episodes in the Majors area of the Emergency Department. Four different ways of taking blood were observed; cannulation and a syringe (38%), cannula with evacuated tube and adaptor (42%), syringe and needle into vein (14%), evacuated tube system used conventionally (6%). Where a syringe was used, two methods of transfer into the sample tube were observed; needle kept on with cap piercing (77%) and needle and evacuated cap both removed (23%). On 20 out of 50 phlebotomy episodes (40%), the potassium EDTA tube was filled prior to the biochemistry tube. A study of ward based phlebotomy found 30 of 1034 samples were haemolysed (2.9%). In the 50 phlebotomy episodes in the Majors area of the Emergency Department 24% produced a haemolysed sample (p<0.0001). Study of the samples taken from all areas of Emergency Medicine over a 7-day period showed 52 of 485 were haemolysed (10.7%; p<0.0001).ConclusionsOur results show that phlebotomy techniques in the Emergency Department vary considerably to those set out in standard protocols and manufacturers' guidelines. The evacuated tube system was used incorrectly over 50% of the time. In particular our results suggest that the use of small lumen cannula in the Majors area is a significant cause of haemolysed samples. Most staff were clearly unaware of the importance of the order of sample draw, which can lead to incorrect results for important analytes such as potassium, calcium and magnesium. There is also likely to be an increased incidence of needle stick injuries with samples being stabbed into collection tubes. Addressing these issues will help improve performance in hard times.
023 Multiprofessional morning handover in the Emergency Department: is it effective?
Authors: Lajko K , Dev S , Adshead N 
Published: September 2011

Objectives and BackgroundsEmergency Department (ED) handovers are arguably more complex than that which takes place in ward environments. This is because of an unpredictable patient load, compressed time-frames to meet operational and performance targets and undifferentiated and undiagnosed nature of the clinical problems. In order to ensure safe, relevant and accurate handovers in our department, we have implemented a novel multiprofessional model incorporating appropriate information exchange, learning opportunities and social interaction. In this study we investigated the effectiveness and usefulness of this new morning handover structure.MethodsA questionnaire containing 10 questions were given to staff over a 1-week period (14 to 20 March 2011). The questions included the following: (a) usefulness of multiprofessional handover (MPH) as a source of information about departmental and trust updates; (b) patient care and operational issues; (c) interprofessional education forum; and (d) comparison with previous handover experience.ResultsWe obtained data from 75 staff members comprising a mixture of the multiprofessional team (clinical lead, matron, all grades of medical staff, all grades of nursing staff, medical and nursing students, emergency pharmacist, domestic violence team, general manager, practice development team and alcohol liaison nurse). The results demonstrated that staff mostly supported the new morning handover structure. It was thought to be a very useful source of information in regards to departmental and trust updates in a multiprofessional forum (75 staff members). Staff members felt it was a forum for interprofessional education (65 staff members). Also, majority agreed that it improved patient care and operational issues within the department and trust wide (67 staff members).ConclusionsOur unique morning handover structure ensures patient safety as well as appropriate transfer of information and responsibility to all involved with the care of patients in the Emergency Department. It offers the opportunity for multiprofessional learning, encourages team work and improves the operational processes within the Emergency Department.