| dna sensor development based on multi-wall carbon nanotubes for label-free influenza virus (type a) detection. | this paper describes the dna immobilization using carbon multi-walled nanotubes (mwcnts) for direct and label-free detection of influenza virus (type a). the dna probe was attached on the sensor surface by means of covalent bonding between the amine and phosphate groups of the dna sequence. the interaction between the dna probe and the mwcnts were characterized by fourier transform infrared (ftir) spectrometry, raman spectra. the hybridization of the dna probe and the target dna were detected by ... | 2009 | 19682995 |
| nuclear dynamics of influenza a virus ribonucleoproteins revealed by live-cell imaging studies. | the negative sense rna genome of influenza a virus is transcribed and replicated in the nuclei of infected cells by the viral rna polymerase. only four viral polypeptides are required but multiple cellular components are potentially involved. we used fluorescence recovery after photobleaching (frap) to characterise the dynamics of gfp-tagged viral ribonucleoprotein (rnp) components in living cells. the nucleoprotein (np) displayed very slow mobility that significantly increased on formation of t ... | 2009 | 19744689 |
| inhibition of influenza virus infection by targeting genome conserved region with non-natural nucleic acid. | two highly conserved 15 base sequences of influenza a virus genome were identified by conserv software, which can detect contiguous conserved sequences of biological sequences. antiviral effect of phosphorothioate oligonucleotide that target these conserved sequences was evaluated by plaque formation assay and cell viability assay. pre-treatment of cells with anti-pb2 (rna polymerase subunit) reduced the size of plaques in a sequence dependent manner. post-treatment of cells with anti-pb2 phosph ... | 2009 | 19749372 |
| genomic diversity of oseltamivir-resistant influenza virus a (h1n1), luxembourg, 2007-08. | | 2009 | 19788831 |
| [influenza in poland in 2007]. | a total number of 374,042 cases of influenza and influenza-like illness were registered in poland in 2007 (incidence 981.3 per 100,000 population). compared to 2006 on 48.6% incidence increase was observed. despite this increase influenza activity in 2007 was among the lowest during the last four decades. regionally the incidence varied from 182.2 in pomorskie voivodeship to 2,957.1 in opolskie. children and adolescents under 15 years of age accounted for 33% of all cases (age specific incidence ... | 2009 | 19799242 |
| studies on the etiology of primary atypical pneumonia : iii. specific neutralization of the virus by human serum. | significant increases in neutralizing antibodies were demonstrated in 42 of a total of 69 persons with a clinical diagnosis of primary atypical pneumonia. detailed titrations of virus-neutralizing antibodies in a representative group of 28 patients are presented. increases of four- to 64-fold were demonstrated. acute-phase titers were 4 or less in 83 per cent and convalescent titers were 16 or over in 86 per cent of these cases. only about half of the number of patients having increases in neutr ... | 1945 | 19871504 |
| biochemical and kinetic analysis of the influenza virus rna polymerase purified from insect cells. | the influenza virus rna polymerase (rdrp) was purified from insect cells (around 0.2mg/l). the rdrp catalyzed all the biochemical reactions of influenza virus transcription and replication in vitro; dinucleotide apg and globin mrna-primed transcription, de novo initiation (replication), and polyadenylation. the optimal mg concentration, ph and temperature were 8mm, 8.0 and 25 degrees c, respectively, which were slightly different from those measured for rdrp of virions. this system is a single-r ... | 2010 | 19932088 |
| differentiation of two distinct clusters among currently circulating influenza a(h1n1)v viruses, march-september 2009. | analysis of all complete genome sequences of the pandemic influenza a(h1n1)v virus available as of 10 september 2009 revealed that two closely related but distinct clusters were circulating in most of the affected countries at the same time. the characteristic differences are located in genes encoding the two surface proteins - haemagglutinin and neuraminidase - and four internal proteins - the polymerase pb2 subunit, nucleoprotein, matrix protein m1 and the non-structural protein ns1. phylogene ... | 2009 | 19941799 |
| role of host-specific amino acids in the pathogenicity of avian h5n1 influenza viruses in mice. | recent large-scale sequence analyses revealed 'signature' amino acids at specific positions in viral proteins that distinguish human influenza viruses from avian viruses. to determine the role of these host lineage-specific amino acids in the pathogenicity of h5n1 avian influenza viruses, we generated mutant viruses possessing signature amino acids in the pb2, pa and np proteins of human influenza isolates ('human-like amino acids') in the genetic background of an avian h5n1 virus, and tested th ... | 2010 | 20016035 |
| active reassortment of h9 influenza viruses between wild birds and live-poultry markets in korea. | surveillance of h9 avian influenza viruses in korean live-poultry markets from september 2004 through october 2007 was carried out to investigate active reassortment between wild migratory birds and domestic poultry in korea. antigenic and phylogenetic analyses showed that most of the isolates belong to the previous korean h9n2-like lineage and differ from the southeastern chinese strains. interestingly, the ck/korea/lpm77/06 group (genotype b) and dk/korea/lpm248/07 group (genotype c) showed un ... | 2010 | 20033463 |
| duplex real-time reverse transcriptase pcr assays for rapid detection and identification of pandemic (h1n1) 2009 and seasonal influenza a/h1, a/h3, and b viruses. | reports of a novel influenza virus type a (h1n1), now designated by the world health organization as pandemic (h1n1) 2009, emerged from the united states and mexico in april 2009. the management of the pandemic in australia required rapid and reliable testing of large numbers of specimens for the novel influenza strain and differentiation from seasonal influenza strains. a real-time reverse transcriptase pcr (rt-pcr) assay for the detection of pandemic (h1n1) 2009 was designed and used with exis ... | 2010 | 20071557 |
| complete genome amplification of equine influenza virus subtype 2. | this work reports a method for rapid amplification of the complete genome of equine influenza virus subtype 2 (h3n8). a thermoscript reverse transcriptase instead of the avian myeloblastosis virus reverse transcriptase or moloney murine leukemia virus reverse transcriptase was used. this enzyme has demonstrated higher thermal stability and is described as suitable to make long cdna with a complex secondary structure. the product obtained by this method can be cloned, used in later sequencing rea ... | 2009 | 20085182 |
| antiviral effect of pyridinium formate, a novel component of coffee extracts. | n-methyl-pyridinium formate, a novel component of coffee extracts, inhibited the multiplication of both dna and rna viruses. in the presence of the compound, the progeny viral yields of both herpes simplex virus type 1 (hsv-1) and poliovirus in hep-2 cells and those of influenza virus type a in mdck cells decreased with increasing concentrations of the compound, although the degree of viral sensitivity to this compound differed. in addition, none of these viruses were directly inactivated by the ... | 2010 | 20127052 |
| an investigation of the pathology and pathogens associated with porcine respiratory disease complex in denmark. | respiratory infections are among the most important diseases of growing pigs. in order to elucidate the multifactorial aetiology of porcine respiratory disease complex (prdc) in denmark, lungs from 148 finishing pigs with cranioventral bronchopneumonia (case group) and 60 pigs without lung lesions (control group) were collected from abattoirs. the pathogens involved in prdc and their interactions were identified and linked to the histopathological diagnosis. the lung samples were cultured for ba ... | 2010 | 20181357 |
| alternative live-attenuated influenza vaccines based on modifications in the polymerase genes protect against epidemic and pandemic flu. | human influenza is a seasonal disease associated with significant morbidity and mortality. influenza vaccination is the most effective means for disease prevention. we have previously shown that mutations in the pb1 and pb2 genes of the live-attenuated influenza vaccine (laiv) from the cold-adapted (ca) influenza virus a/ann arbor/6/60 (h2n2) could be transferred to avian influenza viruses and produce partially attenuated viruses. we also demonstrated that avian influenza viruses carrying the pb ... | 2010 | 20181702 |
| correlation between polymerase activity and pathogenicity in two duck h5n1 influenza viruses suggests that the polymerase contributes to pathogenicity. | the influenza rna polymerase is known to be important in pathogenicity and adaptation of avian influenza viruses to mammalian hosts. however, the molecular mechanisms responsible are only partly understood. here we investigated the role of the polymerase in two different, closely related, h5n1 influenza viruses - a high pathogenic, a/duck/fujian/01/2002 (fj) strain and a low pathogenic, a/duck/guangxi/53/2002 (gx) strain. the polymerase activity of the fj strain was significantly greater than th ... | 2010 | 20211480 |
| detection of influenza a virus neuraminidase and pb2 gene segments by one step reverse transcription polymerase chain reaction. | we describe a single step reverse transcription polymerase chain reaction protocol that can be used to amplify part of the neuraminidase gene segment (segment 6) from all nine subtypes of influenza a virus. the method has also been applied to amplify gene segment 1 of influenza a, which encodes the basic polymerase protein 2 (pb2). the method combines the use of mixed base primers with a "touchdown" thermal cycling program and is applicable to a wide range of nucleic acid targets in which there ... | 2010 | 20300991 |
| a two-tiered model for simulating the ecological and evolutionary dynamics of rapidly evolving viruses, with an application to influenza. | understanding the epidemiological and evolutionary dynamics of rapidly evolving pathogens is one of the most challenging problems facing disease ecologists today. to date, many mathematical and individual-based models have provided key insights into the factors that may regulate these dynamics. however, in many of these models, abstractions have been made to the simulated sequences that limit an effective interface with empirical data. this is especially the case for rapidly evolving viruses in ... | 2010 | 20335193 |
| [molecular characterization of the early phase of the novel influenza a h1n1 (2009) viruses]. | pathogens of the first influenza pandemic this century belong to influenza a h1n1 viruses, which are different from human seasonal h1n1 viruses in antigenic and genetic characterization. to better understand the genetic characteristics and evolution, timely detect variant strains with epidemiological importance, we analyzed in detail the molecular characterization of the early influenza a h1n1 (2009) virus. | 2010 | 20344945 |
| scalable production of influenza virus in hek-293 cells for efficient vaccine manufacturing. | cell culture processes offer an attractive alternative to conventional chicken egg-based influenza vaccine production methods. however, most protocols still rely on the use of adherent cells, which makes process scale-up a challenging issue. in this study, it is demonstrated that the hek-293 human cell line is able to efficiently replicate influenza virus. production in serum-free suspension of hek-293 cultures resulted in high titers of infectious influenza viruses for different subtypes and va ... | 2010 | 20347632 |
| validation of a method for preparing influenza h5n1 simulated samples. | avian influenza virus type a subtype h5n1 and potentially other novel influenza a viruses continue to pose a concern with mutation into a form easily transmitted between humans. the ability to rapidly detect and characterize influenza viruses, and distinguish seasonal and novel influenza a viruses such as h5n1, remains important to minimize morbidity and mortality in humans. as with other rare and emerging viral pathogens, clinical specimens from persons with h5n1 infections are extremely rare. ... | 2010 | 20362615 |
| biochemical characterization of enzyme fidelity of influenza a virus rna polymerase complex. | it is widely accepted that the highly error prone replication process of influenza a virus (iav), together with viral genome assortment, facilitates the efficient evolutionary capacity of iav. therefore, it has been logically assumed that the enzyme responsible for viral rna replication process, influenza virus type a rna polymerase (iav pol), is a highly error-prone polymerase which provides the genomic mutations necessary for viral evolution and host adaptation. importantly, however, the actua ... | 2010 | 20454455 |
| the pb2 subunit of the influenza virus rna polymerase affects virulence by interacting with the mitochondrial antiviral signaling protein and inhibiting expression of beta interferon. | the pb2 subunit of the influenza virus rna polymerase is a major virulence determinant of influenza viruses. however, the molecular mechanisms involved remain unknown. it was previously shown that the pb2 protein, in addition to its nuclear localization, also accumulates in the mitochondria. here, we demonstrate that the pb2 protein interacts with the mitochondrial antiviral signaling protein, mavs (also known as ips-1, visa, or cardif), and inhibits mavs-mediated beta interferon (ifn-beta) expr ... | 2010 | 20538852 |
| temporal and spatial resolution of type i and iii interferon responses in vivo. | although the action of interferons (ifns) has been extensively studied in vitro, limited information is available on the spatial and temporal activation pattern of ifn-induced genes in vivo. we created bac transgenic mice expressing firefly luciferase under transcriptional control of the mx2 gene promoter. expression of the reporter with regard to onset and kinetics of induction parallels that of mx2 and is thus a hallmark for the host response. substantial constitutive expression of the reporte ... | 2010 | 20573823 |
| pathogenicity of highly pathogenic avian h5n1 influenza a viruses isolated from humans between 2003 and 2008 in northern vietnam. | vietnam is one of the countries most affected by highly pathogenic h5n1 influenza a viruses. to evaluate the potential pathogenicity in mammals of h5n1 viruses isolated from humans in vietnam, we determined the sequences of all eight genes of 22 human isolates collected between 2003 and 2008 and compared their virulence in mice. the isolates were classified into clade 1 and clade 2.3.4 and differed in pathogenicity for mice. whilst lysine at position 627 of pb2 (pb2-627k) is a critical virulence ... | 2010 | 20592108 |
| evidence for avian and human host cell factors that affect the activity of influenza virus polymerase. | typical avian influenza a viruses do not replicate efficiently in humans. the molecular basis of host range restriction and adaptation of avian influenza a viruses to a new host species is still not completely understood. genetic determinants of host range adaptation have been found on the polymerase complex (pb1, pb2, and pa) as well as on the nucleoprotein (np). these four viral proteins constitute the minimal set for transcription and replication of influenza viral rna. it is widely documente ... | 2010 | 20631125 |
| influenza a virus polymerase inhibits type i interferon induction by binding to interferon beta promoter stimulator 1. | type i interferons (ifns) are known to be critical factors in the activation of host antiviral responses and are also important in protection from influenza a virus infection. especially, the rig-i- and ips-1-mediated intracellular type i ifn-inducing pathway is essential in the activation of antiviral responses in cells infected by influenza a virus. previously, it has been reported that influenza a virus ns1 is involved in the inhibition of this pathway. we show in this report that the influen ... | 2010 | 20699220 |
| evaluation of an edible blue-green alga, aphanothece sacrum, for its inhibitory effect on replication of herpes simplex virus type 2 and influenza virus type a. | a hot-water extract of aphanothece sacrum, an edible aquacultured blue-green alga, was found to show a remarkable inhibitory effect on the replication of enveloped viruses including herpes simplex virus type 2 (hsv-2) and influenza virus type a (ifv-a, h1n1) in vitro. the main active components were suggested to be sulfated polysaccharides in non-dialyzable portion (aswph). aswph was found to inhibit the viral adsorption to the receptor of the host cells involved in the replication process of hs ... | 2010 | 20699552 |
| pb2 and hemagglutinin mutations are major determinants of host range and virulence in mouse-adapted influenza a virus. | serial mouse lung passage of a human influenza a virus, a/hong kong/1/68 (h3n2) (hk-wt), produced a mouse-adapted variant, ma, with nine mutations that was >10(3.8)-fold more virulent. in this study, we demonstrate that ma mutations of the pb2 (d701n) and hemagglutinin (ha) (g218w in ha1 and t156n in ha2) genes were the most adaptive genetic determinants for increased growth and virulence in the mouse model. recombinant viruses expressing each of the mutated ma genome segments on the hk-wt backb ... | 2010 | 20702632 |
| adjuvant effect of bacillus firmus on the expression of cytokines and toll-like receptors in mouse nasopharynx-associated lymphoid tissue (nalt) after intranasal immunization with inactivated influenza virus type a. | due to the persisting threat of development of new highly pathogenic influenza a subtypes, a mucosal vaccination which would induce a potent and cross-protective reaction is desirable. we succeeded in mucosal immunization of mice with an inactivated influenza a virus by using delipidated bacillus firmus (dbf) as adjuvant. the mechanism of adjuvant effect was followed in nalt by comparing the response after intranasal immunization by inactivated influenza virus type a (h1n1) alone, adjuvant alone ... | 2010 | 20709105 |
| nanoparticle-based biosensor for the detection of emerging pandemic influenza strains. | electrically active magnetic (eam) nanoparticles, consisting of aniline monomer polymerized around gamma iron(iii) oxide (γ-fe(2)o(3)) cores, serve as the basis of a direct-charge transfer biosensor developed for detection of surface glycoprotein hemagglutinin (ha) from the influenza a virus (fluav) h5n1 (a/vietnam/1203/04). h5n1 preferentially binds α2,3-linked host glycan receptors. eam nanoparticles were immunofunctionalized with antibodies against target ha. glycans preincubated with ha in 1 ... | 2010 | 20729069 |
| [effects of yinqiao detoxifcation oral liquid on nk cell viability and serum concentration of ifn-gamma in scid mouse infected by influenza virus fm1]. | to explore the dynamic effects of yinqiao detoxifcation oral liquid (yqd) on nk cell lysis in spleen and serum concentration of ifn-gamma in scid mouse infected by influenza a virus fm1. | 2010 | 20822020 |
| immunogenicity of influenza vaccine in children with pediatric rheumatic diseases receiving immunosuppressive agents. | children with rheumatic diseases receiving immunosuppressive therapy are a high-risk group for influenza virus infection; however, few data are available regarding the efficacy and safety of influenza vaccine for those individuals. | 2011 | 20861757 |
| ubiquitination and deubiquitination of np protein regulates influenza a virus rna replication. | influenza a virus rna replication requires an intricate regulatory network involving viral and cellular proteins. in this study, we examined the roles of cellular ubiquitinating/deubiquitinating enzymes (dubs). we observed that downregulation of a cellular deubiquitinating enzyme usp11 resulted in enhanced virus production, suggesting that usp11 could inhibit influenza virus replication. conversely, overexpression of usp11 specifically inhibited viral genomic rna replication, and this inhibition ... | 2010 | 20924359 |
| [the origin of the genetic variability of influenza viruses]. | to better understand the significant variability displayed by influenza viruses, we need to be aware not only of its genetic characteristics, but also of the effect this genetic makeup has on proteins associated with viral replication and antigenicity. the origin of such diversity is due first and foremost to its segmented genome that allows segment reassortment (antigenic shift) and second to the error prone viral polymerase (antigenic drift) responsible of copying the genes enclosed in these s ... | 2010 | 20957816 |
| the n terminus of pa polymerase of swine-origin influenza virus h1n1 determines its compatibility with pb2 and pb1 subunits through a strain-specific amino acid serine 186. | despite several lines of evidence suggesting possible mechanisms by which the influenza virus polymerase complex, comprising pb2, pb1 and pa, work in concert during virus replication, exactly how they function is not entirely understood. the n terminal region of the pa subunit has been shown to play a key role in various functions through a number of conserved amino acid residues. however, little is known about the role of amino acids reported to be unique for a virus strain. here, we investigat ... | 2010 | 21056603 |
| in vitro inhibitory activity of alpinia katsumadai extracts against influenza virus infection and hemagglutination. | alpinia katsumadai (ak) extracts and fractions were tested for in vitro antiviral activities against influenza virus type a, specially human a/pr/8/34 (h1n1) and avian a/chicken/korea/ms96/96 (h9n2), by means of time-of-addition experiments; pre-treatment, simultaneous treatment, and post treatment. | 2010 | 21062499 |
| viral respiratory tract infections among patients with acute undifferentiated fever in vietnam. | to investigate the proportion of viral respiratory tract infections among acute undifferentiated fevers (aufs) at primary health facilities in southern vietnam during 2001-2005, patients with auf not caused by malaria were enrolled at twelve primary health facilities and a clinic for malaria control program. serum was collected on first presentation (t0) and after 3 weeks (t3) for serology. after exclusion of acute dengue infection, acute and convalescent serum samples from 606 patients were usi ... | 2010 | 21073032 |
| pathogenicity of swine influenza viruses possessing an avian or swine-origin pb2 polymerase gene evaluated in mouse and pig models. | pb2 627k is a determinant of influenza host range and contributes to the pathogenicity of human-, avian-, and mouse-adapted influenza viruses in the mouse model. here we used mouse and pig models to analyze the contribution of a swine-origin and avian-origin pb2 carrying either 627k or 627e in the background of the classical swine h1n1 (a/swine/iowa/15/30; 1930) virus. the results showed pb2 627k is crucial for virulence in the mouse model, independent of whether pb2 is derived from an avian or ... | 2010 | 21074235 |
| emerging topics and new perspectives on hla-g. | following the fifth international conference on non-classical hla-g antigens (hla-g), held in paris in july 2009, we selected some topics which focus on emerging aspects in the setting of hla-g functions. in particular, hla-g molecules could play a role in: (1) various inflammatory disorders, such as multiple sclerosis, intracerebral hemorrhage, gastrointestinal, skin and rheumatic diseases, and asthma, where they may act as immunoregulatory factors; (2) the mechanisms to escape immune surveilla ... | 2010 | 21080027 |
| a diagnostic algorithm for detection of antibodies to influenza a viruses in dogs in italy (2006-2008). | since 2004, there have been several reports of influenza a virus (fluav) infection in dogs. dogs have been infected with equine influenza h3n8, avian influenza h3n2 and h5n1, and the pandemic h1n1 virus. because of recent avian and equine influenza outbreaks in italy, the objectives of the present study were to estimate the level of exposure of italian dogs to influenza a viruses and to assess a diagnostic algorithm for detection of fluav exposure in dogs. sera collected from 6,858 dogs from 200 ... | 2010 | 21088175 |
| identification of the 3' and 5' terminal sequences of the 8 rna genome segments of european and north american genotypes of infectious salmon anemia virus (an orthomyxovirus) and evidence for quasispecies based on the non-coding sequences of transcripts. | infectious salmon anemia (isa) virus (isav) is a pathogen of marine-farmed atlantic salmon (salmo salar); a disease first diagnosed in norway in 1984. this virus, which was first characterized following its isolation in cell culture in 1995, belongs to the family orthomyxoviridae, genus, isavirus. the isavirus genome consists of eight single-stranded rna segments of negative sense, each with one to three open reading frames flanked by 3' and 5' non-coding regions (ncrs). although the terminal se ... | 2010 | 21092282 |
| miller fisher syndrome in a toddler with influenza a (ph1n1) infection. | a 17-month-old previously healthy child presented with a 2-day history of inability to fully open his eyes and slight gait ataxia. in the month preceding admission, he had had low grade, intermittent fevers, followed by a nonproductive cough and sneezing. during hospital admission he lost deep tendon reflexes and was unable to walk. lumbar puncture revealed abnormally high protein, and a nasopharyngeal specimen was positive for influenza a (ph1n1). he received intravenous immunoglobulin and osel ... | 2010 | 21115746 |
| np body domain and pb2 contribute to increased virulence of h5n1 highly pathogenic avian influenza viruses in chickens. | the molecular basis of pathogenicity of h5n1 highly pathogenic avian influenza (hpai) viruses in chickens remains largely unknown. h5n1 a/chicken/yamaguchi/7/2004 virus (ckym7) replicates rapidly in macrophages and vascular endothelial cells in chickens, causing sudden death without fever or gross lesions, while h5n1 a/duck/yokohama/aq10/2003 virus (dkyk10) induces high fever, severe gross lesions, and a prolonged time to death, despite the 98% amino acid identity between the two viruses. to exp ... | 2010 | 21123376 |
| public perceptions of pandemic influenza resource allocation: a deliberative forum using grid/group analysis. | the emergence of virulent avian influenza a subtypes with potential to evolve into novel human subtypes prompted directives from the world health organisation recommending that countries prepare for a pandemic. in response the australian government developed the australian health management plan for pandemic influenza (ahmppi), which includes strategies to contain and/or manage a pandemic. to implement these strategies successfully, community compliance is necessary. our qualitative study invest ... | 2011 | 21228887 |
| detection of various respiratory viruses in patients with influenza-like illness before and after emergence of the 2009 pandemic h1n1 influenza virus in okinawa. | | 2011 | 21266765 |
| inhibition of highly pathogenic avian h5n1 influenza virus propagation by rna oligonucleotides targeting the pb2 gene in combination with celecoxib. | highly pathogenic avian influenza virus h5n1 can cause acute respiratory infections with an uncontrolled virus-induced cytokine storm in both poultry and humans. in view of the high mortality of h5n1 influenza virus infection, the development of novel broad-spectrum prophylactic and therapeutic agents against infection is urgently needed. in the present study, we attempted to explore whether the combinational use of a viral gene-targeted agent and immunomodulator is feasible as a new strategy ag ... | 2011 | 21449039 |
| [research progress in molecular determinants of neuraminidase, polymerase basic protein 2 and nonstructural protein 1, related to virulence of influenza a virus--a review]. | it is gradually recognized that host specificity and pathogenicity of influenza a virus could also be affected by proteins other than hemagglutinin (ha) due to its polygenic nature. in this review, detailed description was focused mainly on neuraminidase (na), polymerase basic protein 2 (pb2) and nonstructural protein 1 (ns1), especially their molecular determinants associated with virulence and host range restriction of influenza a virus. | 2011 | 21465783 |
| importance of viral genomic composition in modulating glycoprotein content on the surface of influenza virus particles. | despite progress in our knowledge of the internal organisation of influenza virus particles, little is known about the determinants of their morphology and, more particularly, of the actual abundance of structural proteins at the virion level. to address these issues, we used cryo-em to focus on viral (and host) factors that might account for observed differences in virion morphology and characteristics such as size, shape and glycoprotein (gp) spike density. twelve recombinant viruses were char ... | 2011 | 21470649 |
| virological surveillance and phylogenetic analysis of the pb2 genes of influenza viruses isolated from wild water birds flying from their nesting lakes in siberia to hokkaido, japan in autumn. | recent introduction of h5n1 highly pathogenic avian influenza virus (hpaiv) in wild birds from poultry in eurasia signaled the possibility that this virus may perpetuate in nature. surveillance of avian influenza especially in migratory birds, therefore, has been conducted to provide information on the viruses brought by them to hokkaido, japan, from their nesting lakes in siberia in autumn. during 2008-2009, 62 influenza viruses of 21 different combinations of hemagglutinin (ha) and neuraminida ... | 2011 | 21476486 |
| boom and bust cycles in virus growth suggest multiple selective forces in influenza a evolution. | abstract: background: influenza a virus evolution in humans is driven at least in part by mutations allowing the virus to escape antibody neutralization. little is known about the evolution of influenza in birds, a major reservoir of influenza a. methods: neutralizing polyclonal antiserum was raised in chicken against reassortant influenza virus, calx, bearing the hemagglutinin (ha) and neuraminidase (na) of a/california/7/2004 [h3n2]. calx was serially passaged in the presence of anti-calx poly ... | 2011 | 21501520 |
| production of influenza pseudotyped lentiviral particles and their use in influenza research and diagnosis: an update. | pseudotyped viral particles are being used as safe surrogates to mimic the structure and surface of many viruses, including highly pathogenic viruses such as avian influenza h5n1, to investigate biological functions mediated by the envelope proteins derived from these viruses. the first part of this article evaluates and discusses the differences in the production and characterization of influenza pseudoparticles. the second part focuses on the applications that such a flexible tool can provide ... | 2011 | 21504401 |
| virulence and genetic compatibility of polymerase reassortant viruses derived from the pandemic (h1n1) 2009 virus and circulating influenza a viruses. | gene mutations and reassortment are key mechanisms by which influenza a virus acquires virulence factors. to evaluate the role of the viral polymerase replication machinery in producing virulent pandemic (h1n1) 2009 influenza viruses, we generated various polymerase point mutants (pb2: 627k/701n, pb1: expression of pb1-f2 protein, and pa : 97i) and reassortant viruses with various sourse of influenza viruses by reverse genetics. although the point mutations produced no significant change in path ... | 2011 | 21507962 |
| mx is dispensable for interferon-mediated resistance of chicken cells against influenza a virus. | the type i interferon (ifn) system plays an important role in antiviral defence against influenza a viruses (fluav) which are natural chicken pathogens. studies in mice identified the mx1 protein as key effector molecule of the ifn-induced antiviral state against fluav. chicken mx genes are highly polymorphic, and recent studies suggested that an asn/ser polymorphism at amino acid position 631 might determine the antiviral activity of the chicken mx protein. by employing chicken embryo fibroblas ... | 2011 | 21632756 |
| validation of an influenza virus a 5'taq nuclease assay for the detection of equine influenza virus a rna in nasal swab samples. | describe the in-house validation of a previously reported influenza virus type a 5'taq nuclease assay for detecting equine influenza virus a rna in nasal swab material. | 2011 | 21711285 |
| [influenza in poland in 2009]. | a total number of 1,081,974 cases of influenza and influenza-like illness were registered in poland in 2009 (incidence 2,835.9 per 100,000 population). it was nearly 5 times more than in 2008. the impact on increase of the number of reported cases have had two factors: the pandemic of influenza caused by virus a(h1n1)v, and increasing of the surveillance sensitivity. 3,177 (0.29%) cases was laboratory confirmed. in the area of particular regions incidence ranged from 805.2 in świetokrzyskie voiv ... | 2011 | 21913459 |
| reversion of pb2-627e to -627k during replication of an h5n1 clade 2.2 virus in mammalian hosts depends on the origin of the nucleoprotein. | h5n1 highly pathogenic avian influenza viruses (hpaiv) of clade 2.2 spread from southeast asia to europe. intriguingly, in contrast to all common avian strains specifying glutamic acid at position 627 of the pb2 protein (pb2-627e), they carry a lysine at this position (pb2-627k), which is normally found only in human strains. to analyze the impact of this mutation on the host range of hpaiv h5n1, we altered pb2-627k to pb2-627e in the european isolate a/swan/germany/r65/2006 (r65). in contrast t ... | 2011 | 21849466 |
| avian influenza: public health and food safety concerns. | avian influenza (ai) is a disease or asymptomatic infection caused by influenzavirus a. ai viruses are species specific and rarely cross the species barrier. however, subtypes h5, h7, and h9 have caused sporadic infections in humans, mostly as a result of direct contact with infected birds. h5n1 high pathogenicity avian influenza (hpai) virus causes a rapid onset of severe viral pneumonia and is highly fatal (60% mortality). outbreaks of ai could have a severe economic and social impact on the p ... | 2011 | 22129374 |
| comparison of two commercial enzyme-linked immunosorbent assays for detection of influenza a virus antibodies. | serologic tools for influenza a virus (fluav) antibody testing of wild birds are currently limited. in the present study, 2 commercial enzyme-linked immunosorbent assays (elisas) for detection of fluav antibodies, the idexx ai multis-screen ab test and the id vet id screen influenza a antibody competition, were compared. sera obtained from mallards (anas platyrhynchos), experimentally infected with 8 fluav subtypes (n = 48), and field serum samples, collected from 11 wild bird species (n = 247), ... | 2011 | 21908267 |
| Host- and strain-specific regulation of influenza virus polymerase activity by interacting cellular proteins. | Highly pathogenic avian influenza A (HPAI) viruses of the H5N1 subtype have recently emerged from avian zoonotic reservoirs to cause fatal human disease. Adaptation of HPAI virus RNA-dependent RNA polymerase (PB1, PB2, and PA proteins) and nucleoprotein (NP) to interactions with mammalian host proteins is thought to contribute to the efficiency of viral RNA synthesis and to disease severity. While proteomics experiments have identified a number of human proteins that associate with H1N1 polymera ... | 2011 | 21846828 |
| influence of pb2 host range determinants on the intranuclear mobility of the influenza a virus polymerase. | avian influenza a viruses often do not propagate efficiently in mammalian cells. the viral polymerase protein pb2 is important for this host restriction, with amino-acid polymorphisms at residue 627 and other positions acting as 'signatures' of avian or human adapted viruses. restriction is hypothesised to result from differential interactions (either positive or inhibitory) with unidentified cellular factors. we applied fluorescence recovery after photobleaching (frap) to investigate the mobili ... | 2011 | 21471313 |
| detection of influenza a virus in porcine oral fluid samples. | porcine oral fluids have been used for the detection of porcine reproductive and respiratory syndrome virus and porcine circovirus-2. the objective of the present study was to determine whether influenza a virus (fluav) is present in porcine oral fluids at detectable levels and to validate a standard fluav molecular diagnostic test for porcine oral fluids. pen-based oral fluid samples were collected on 3, 4, 5, and 6 days postinfection (dpi) from 4 groups of 6 pigs each that were inoculated intr ... | 2011 | 21398442 |
| genetic bases of the temperature-sensitive phenotype of a master donor virus used in live attenuated influenza vaccines: a/leningrad/134/17/57 (h2n2). | trivalent live attenuated influenza vaccines whose type a components are based on cold-adapted a/leningrad/134/17/57 (h2n2) (calen17) master donor virus (mdv) have been successfully used in russia for decades to control influenza. the vaccine virus comprises hemagglutinin and neuraminidase genes from the circulating viruses and the remaining six genes from the mdv. the latter confer temperature-sensitive (ts) and attenuated (att) phenotypes. the ts phenotype of the vaccine virus is a critical bi ... | 2011 | 21315402 |
| possible reason for cross-species and cross-subtype reassortment in polymerase basic protein 2 from influenza a virus. | the reassortment in proteins from influenza a viruses among human, swine, and eurasian avian strains formed a new influenza a virus leading to the first pandemic in this century, which suggests that the barrier between species and between subtypes would not be strong enough to prevent the cross-species infection and cross-subtype reassortment from occurring. in this study, we intensively used the anova including its model i and model ii to analyze 2430 polymerase basic proteins 2 (pb2) of influe ... | 2011 | 21171947 |
| pancreas rejection after pandemic influenzavirus a(h1n1) vaccination or infection: a report of two cases. | | 2010 | 21121966 |
| [screening of proteins interacting with avian influenza virus nucleoprotein by yeast two-hybrid system in human brain cdna library]. | avian influenza virus nucleoprotein (np) is important in viral transcription, replication and determining host specificity of influenza virus. yeast two-hybrid technique was applied to screen for proteins interacting with virus nucleoprotein, so as to further elucidate the interaction between virus nucleoprotein and cellular proteins, as well as the interaction between virus and host. to explore new proteins interacted with np protein, a human brain cdna library was screened using yeast two-hybr ... | 2010 | 21090106 |
| modifications in the polymerase genes of a swine-like triple-reassortant influenza virus to generate live attenuated vaccines against 2009 pandemic h1n1 viruses. | on 11 june 2009, the world health organization (who) declared that the outbreaks caused by novel swine-origin influenza a (h1n1) virus had reached pandemic proportions. the pandemic h1n1 (h1n1pdm) virus is the predominant influenza virus strain in the human population. it has also crossed the species barriers and infected turkeys and swine in several countries. thus, the development of a vaccine that is effective in multiple animal species is urgently needed. we have previously demonstrated that ... | 2010 | 20962084 |
| [influenza in poland in 2008]. | a total number of 227,346 cases of influenza and influenza-like illness were registered in poland in 2008 (incidence 596.5 per 100,000 population). compared to 2007 on 39.2% incidence decrease was observed. regionally the incidence varied from 142.3 in swietokrzyskie voivodeship to 1,830.6 in opolskie. children and adolescents under 15 years of age accounted for 36% of all cases (age group incidence 1,415.6). in this age group the incidence varied regionally from 342.9 in swietokrzyskie voivodes ... | 2010 | 20731217 |
| generation and comprehensive analysis of an influenza virus polymerase cellular interaction network. | the influenza virus transcribes and replicates its genome inside the nucleus of infected cells. both activities are performed by the viral rna-dependent rna polymerase that is composed of the three subunits pa, pb1, and pb2, and recent studies have shown that it requires host cell factors to transcribe and replicate the viral genome. to identify these cellular partners, we generated a comprehensive physical interaction map between each polymerase subunit and the host cellular proteome. a total o ... | 2011 | 21994455 |
| comparative analysis of avian influenza virus diversity in poultry and humans during a highly pathogenic avian influenza a (h7n7) virus outbreak. | although increasing data have become available that link human adaptation with specific molecular changes in nonhuman influenza viruses, the molecular changes of these viruses during a large highly pathogenic avian influenza virus (hpai) outbreak in poultry along with avian-to-human transmission have never been documented. by comprehensive virologic analysis of combined veterinary and human samples obtained during a large hpai a (h7n7) outbreak in the netherlands in 2003, we mapped the acquisiti ... | 2011 | 21849451 |
| A novel function of the N-terminal domain of PA in assembly of influenza A virus RNA polymerase. | Transcription and replication of the negative-sense single-stranded influenza A virus genomic viral RNA are catalyzed by the viral RNA polymerase, which is a trimeric complex encoded by the three largest segments of the influenza virus genome: PB1, PB2, and PA. Numerous studies of the trimeric polymerase complex assembly have substantially contributed to current understanding of influenza virus replication. However, the dynamics of spatial and temporal macromolecular interactions involving virus ... | 2011 | 22001919 |
| amino acid residues 253 and 591 of the pb2 protein of avian influenza virus a h9n2 contribute to mammalian pathogenesis. | we investigated the tropism, host responses, and virulence of two variants of a/quail/hong kong/g1/1997 (h9n2) (h9n2/g1) with d253n and q591k in the pb2 protein in primary human macrophages and bronchial epithelium in vitro and in mice in vivo. virus with pb2 d253n and q591k had greater polymerase activity in minireplicon assays, induced more tumor necrosis factor alpha (tnf-+¦) in human macrophages, replicated better in differentiated normal human bronchial epithelial (nhbe) cells, and was more ... | 2011 | 21734052 |
| kinetics of uv(254) inactivation of selected viral pathogens in a static system. | aims: the objective of this study was to estimate uv(254) inactivation constants for four viral pathogens: influenza virus type a, porcine respiratory and reproductive syndrome virus (prrsv), bovine viral diarrhoea virus (bvdv) and reovirus. methods and results: viruses in culture medium were exposed to one of nine doses of uv(254) and then titrated for infectious virus. analysis showed that viral inactivation by uv(254) was more accurately described by a two-stage inactivation model vs a stan ... | 2011 | 21624016 |
| anti-inflammatory, antiviral and quantitative study of quercetin-3-o-β-d-glucuronide in polygonum perfoliatum l. | quercetin-3-o-β-d-glucuronide, isolated from polygonum perfoliatum l., was evaluated by antiviral efficacy against influenza a virus and anti-inflammatory activity in vivo in mouse, and it was used for quality evaluation of p. perfoliatum l.. in vivo study, oral administration of quercetin-3-o-β-d-glucuronide significantly suppressed ear edema induced by dimethyl benzene and peritoneal permeability induced by acetic acid in mice, and quercetin-3-o-β-d-glucuronide also showed to possess inhibitor ... | 2011 | 21570451 |
| dna microarray-based solid-phase rt-pcr for rapid detection and identification of influenza virus type a and subtypes h5 and h7. | endemic of avian influenza virus (aiv) in asia and epizootics in some european regions have caused considerable public concern on a possible pandemic of aiv. a rapid method for virus detection and effective surveillance in wild avian, poultry production as well as in humans is required. in this article, a dna microarray-based solid-phase polymerase chain reaction (pcr) approach has been developed for rapid detection of influenza virus type a and for simultaneous identification of pathogenic viru ... | 2011 | 21396541 |
| gene design, cloning and protein-expression methods for high-value targets at the seattle structural genomics center for infectious disease. | any structural genomics endeavor, particularly ambitious ones such as the niaid-funded seattle structural genomics center for infectious disease (ssgcid) and center for structural genomics of infectious disease (csgid), face technical challenges at all points of the production pipeline. one salvage strategy employed by ssgcid is combined gene engineering and structure-guided construct design to overcome challenges at the levels of protein expression and protein crystallization. multiple construc ... | 2011 | 21904039 |
| anti-influenza virus effect of aqueous extracts from dandelion. | abstract: | 2011 | 22168277 |
| biochemical impact of the host adaptation associated pb2 e627k mutation on the temperature-dependent rna synthesis kinetics of influenza a virus polymerase complex. | most avian influenza a viruses, which preferentially replicate at the high temperatures found in the digestive tract of birds, have a glutamic acid at residue 627 of the viral rna polymerase pb2 subunit (627e), whereas the human viruses, which optimally replicate at the low temperatures observed in the human respiratory tract, have a lysine (627k). the mechanism of action for this mutation is still not understood, although, interaction with host factors has been proposed to play a major role. in ... | 2011 | 21816827 |
| low immunogenicity of seasonal trivalent influenza vaccine among patients receiving docetaxel for a solid tumour: results of a prospective pilot study. | background:patients receiving cytotoxic therapy for solid tumours are at risk of severe influenza. however, few data are available regarding the immunogenical efficacy of influenza vaccine in these patients.methods:in this prospective study, 25 patients with breast (n=13) or prostate (n=12) cancer received a trivalent inactivated influenza vaccine along with docetaxel (taxotere) administration. the influenza virus type a and b antibody titres were measured using haemagglutinin inhibition (garten ... | 2011 | 21540859 |