| pathogenic and molecular characterization of the h5n1 avian influenza virus isolated from the first human case in zhejiang province, china. | since the reemergence of highly pathogenic avian influenza virus h5n1, it caused disease in 20 people with 13 deaths in mainland of china. on february 21, 2006, the first suspected human case in zhejiang province was reported. pathogenic analyses, including reverse transcriptase polymerase chain reaction (rt-pcr), real-time rt-pcr, and virus isolation, were carried out to confirm the pathogen from tracheal aspirate specimen. in addition, antibody in serum sample was detected using hemagglutinati ... | 2007 | 17509792 |
| development of a multiplex real-time pcr assay using sybr green 1 chemistry for simultaneous detection and subtyping of h9n2 influenza virus type a. | avian influenza viruses are pathogens of economical and public health concerns. however, infections caused by low pathogenic avian influenza particularly h9n2 subtype are not associated with clear clinical features. hence, rapid detection and subtyping of the virus will enable immediate measures to be implemented for preventing widespread transmission. this study highlights the development of a multiplex real-time reverse-transcriptase polymerase chain reaction (rrt-pcr) assay using sybr green 1 ... | 2007 | 17512062 |
| three-dimensional model for the isolated recombinant influenza virus polymerase heterotrimer. | the genome of influenza a virus is organized into eight ribonucleoprotein complexes (rnps), each containing one rna polymerase complex. this rna polymerase has also been found non-associated to rnps and is possibly involved in distinct functions in the infection cycle. we have expressed the virus rna polymerase complex by co-tranfection of the pb1, pb2 and pa genes in mammalian cells and the heterotrimer was purified by the tap tag procedure. its 3d structure was determined by electron microscop ... | 2007 | 17517766 |
| influenza virus type a serosurvey in cats. | | 2007 | 17561573 |
| influenzavirus infection is a primary cause of febrile respiratory illness in hiv-infected adults, despite vaccination. | there are, to our knowledge, no prospective studies of respiratory tract infections in human immunodeficiency virus (hiv)-infected adults in the highly active antiretroviral therapy (haart) era. we performed a surveillance study of outpatients who presented with fever and respiratory symptoms to examine the role of viral pathogens in these patients. | 2007 | 17578785 |
| phenotypic properties resulting from directed gene segment reassortment between wild-type a/sydney/5/97 influenza virus and the live attenuated vaccine strain. | widespread use of a live-attenuated influenza vaccine (laiv) in the united states (licensed as flumist) raises the possibility that vaccine viruses will contribute gene segments to the type a influenza virus gene pool. progeny viruses possessing new genotypes might arise from genetic reassortment between circulating wild-type (wt) and vaccine strains, but it will be difficult to predict whether they will be viable or exhibit novel properties. to begin addressing these uncertainties, reverse-gene ... | 2007 | 17599381 |
| [two types of np-np associations in influenza virus-infected cells]. | two types of np-np associations are shown to form in the influenza virus-infected cells. early np synthesis gives rise to np associations stabilized by relatively weak bonds. these structures are designed as np multimers. the high protease- and heat-sensitivities allow np-multimers to be regarded as incompletely folded proteins. post-translationally, np-multimers transform to compact np associations (np oligomers) that are relatively highly heat-and protease-resistant. the np-multimers untransfo ... | 2007 | 17601043 |
| [do you have a grip on influenza? (interview by dr. thomas meissner)]. | | 2007 | 17615653 |
| impact of respiratory infections by influenza viruses a and b in pediatrics patients from federal university of paraná, brazil. | the objective of the present study was to determine the impact of influenza virus on pediatric hospitalized patients. we retrospectively reviewed records of children with laboratory diagnoses, by cell culture and/or indirect immunofluorescence assay, of influenza virus seen in a period of 6 years. a total of 1,033 samples were analyzed, 45 (4.3%) of them being reactive to influenza virus. thirty-one samples were positive to influenza a virus and 14 to influenza b. the frequency of hospitalizatio ... | 2007 | 17625765 |
| [live influenza vaccine: laboratory markers of attenuation]. | screening for candidate reassortants is an important step in the development of live influenza vaccine (liv). the temperature-sensitive (ts) and cold-adapted (ca) phenotypes of vaccine strains are generally determined, by employing chicken embryos, and used as ts and ca attenuation markers. however, it is difficult to use the egg-determined ts phenotypes of vaccine candidate reassortants as an attenuation marker due to a wide circulation of natural ts epidemic influenza viruses. this study used ... | 2007 | 17722606 |
| influenza virus mrna translation revisited: is the eif4e cap-binding factor required for viral mrna translation? | influenza virus mrnas bear a short capped oligonucleotide sequence at their 5' ends derived from the host cell pre-mrnas by a "cap-snatching" mechanism, followed immediately by a common viral sequence. at their 3' ends, they contain a poly(a) tail. although cellular and viral mrnas are structurally similar, influenza virus promotes the selective translation of its mrnas despite the inhibition of host cell protein synthesis. the viral polymerase performs the cap snatching and binds selectively to ... | 2007 | 17855553 |
| creating a model program for influenza surveillance in california: results from the 2005-2006 influenza season. | influenza surveillance is valuable for monitoring trends in influenza-related morbidity and mortality. using the 2005-2006 influenza season as an example, this paper describes a comprehensive influenza surveillance program used by the california department of public health (cdph). | 2007 | 17888862 |
| growth of h5n1 influenza a viruses in the upper respiratory tracts of mice. | highly pathogenic avian h5n1 influenza a viruses have spread throughout asia, europe, and africa, raising serious worldwide concern about their pandemic potential. although more than 250 people have been infected with these viruses, with a consequent high rate of mortality, the molecular mechanisms responsible for the efficient transmission of h5n1 viruses among humans remain elusive. we used a mouse model to examine the role of the amino acid at position 627 of the pb2 viral protein in efficien ... | 2007 | 17922570 |
| [influenza in poland in 2005]. | a total number of 773,234 cases of influenza and influenza-like illness registered in poland in 2004 (incidence 1921.4 per 100,000 population). regionally the incidence ranged from 3391.8 per 100,000 population in mazowieckie to 364.0 in swietokrzyskie. children and adolescents under 15 years of age accounted for 34.5% of all cases (age specific incidence 4045.3 per 100,000). in this age group the incidence varied regionally from 6381.1 in mazowieckie to 797.6 in swietokrzyskie. 1469 patients (0 ... | 2007 | 17956033 |
| evaluation of the presence of selected viral and bacterial nucleic acids in pericardial samples from dogs with or without idiopathic pericardial effusion. | many viruses have been identified in pericardial fluid and in tissue samples from humans with pericarditis by means of molecular diagnostics. in canine idiopathic pericardial effusion there is as yet no conclusive evidence to support the involvement of an infectious agent. this study was designed to investigate a possible relationship between idiopathic pericardial effusion in dogs and viruses most commonly encountered in humans affected with viral pericarditis. coxsackievirus b3 rna, influenza ... | 2009 | 17959400 |
| mutational analyses of packaging signals in influenza virus pa, pb1, and pb2 genomic rna segments. | the influenza a virus genome consists of eight negative-sense rna segments that must each be packaged to produce an infectious virion. we have previously mapped the minimal cis-acting regions necessary for efficient packaging of the pa, pb1, and pb2 segments, which encode the three protein subunits of the viral rna polymerase. the packaging signals in each of these rnas lie within two separate regions at the 3' and 5' termini, each encompassing the untranslated region and extending up to 80 base ... | 2008 | 17959657 |
| the antiviral potential of interferon-induced cotton rat mx proteins against orthomyxovirus (influenza), rhabdovirus, and bunyavirus. | influenza a virus (fluav) is an important human pathogen able to cause devastating pandemics. recently, cotton rats have been proposed as an animal model to study the innate immune response against fluav and other human pathogens. the interferon (ifn)-induced mx gtpases are part of the cell-autonomous innate immune response against viruses. we, therefore, tested the antiviral activity of the two cotton rat mx proteins that were recently identified. the nuclear cotton rat mx1 protein was found to ... | 2007 | 17970694 |
| a common pathway mediated through toll-like receptors leads to t- and natural killer-cell immunosuppression. | t- and natural killer (nk)-cell immunosuppression associated with zeta-chain down-regulation has been described in cancer, autoimmune, and infectious diseases. however, the precise stimuli leading to this bystander phenomenon in such different pathogen-dependent and sterile pathologies remained unresolved. here, we demonstrate that toll-like receptors (tlrs) play a major role in the induction of innate and adaptive immune system suppression; repetitive administration of single tlr 2, 3, 4, or 9 ... | 2008 | 17991807 |
| practical challenges in a hospital pandemic influenza preparedness plan. | | 2007 | 18078245 |
| recent changes in the trends of seasonal influenza outbreaks in the nagano prefectural area of japan: an oseltamivir effect? | we carried out a study to assess the pharmacological role of oseltamivir in the regulation of influenza epidemics in japan, examining data for the years 1998 to 2006 from nagano prefecture. oseltamivir is effective for the treatment of influenza, and its use in japan has increased in the 3 years from 2003 to 2006. we found that, in the nagano prefectural area, the peak in the number of influenza infections showed a deviation to later periods after the 2003 season. and after 2003, it also took a ... | 2007 | 18095096 |
| [case of adult influenza type a virus-associated encephalopathy successfully treated with primary multidisciplinary treatments]. | the patient in this study was a 43-year-old woman who had become unconscious after contracting influenza virus type a infection. brain ct showed severe brain swelling. brain mri also showed brain edema with no specific abnormality on t2-weighted images. we diagnosed her as having influenza type a virus-associated encephalopahty and treated her with oseltamivir, methylprednisolone pulse therapy, and a high dose of intravenous immunoglobulins. in addition, we treated her with hypothermia and a hig ... | 2007 | 18095496 |
| protective and cross-protective mucosal immunization of mice by influenza virus type a with bacterial adjuvant. | mucosal immunization by inactivated viruses often fails to evoke a sufficient immune response. intensive efforts have been made to enhance the response by suitable adjuvants. we used the g+ nonpathogenic delipidated bacterium bacillus firmus with pronounced immunostimulatory properties as an adjuvant for immunizing mice with inactivated influenza virus type a. balb/c mice were immunized intratracheally with inactivated influenza a h1n1 and h3n2 viruses. the production of antibodies in sera and s ... | 2008 | 18160106 |
| [synthesis and antiviral activity of lupane triterpenoids with modified cycle e]. | a reductive transformation of the peroxide products of ozonolysis of derivatives of 3beta-o-acetyl-22(17-->28)-abeo-lupa-17(28),20(29)-diene and the subsequent intramolecular ketalization led to a compound with a trioxane fragment. this is a new approach to a skeletal modification of triterpenoid cycle e. an activity of the synthesized compounds was found toward the viruses of type a influenza and herpes simplex. | 2007 | 18173126 |
| oligomerization of the influenza virus polymerase complex in vivo. | the influenza virus polymerase is a heterotrimer formed by the pb1, pb2 and pa subunits and is responsible for virus transcription and replication. we have expressed the virus polymerase complex by co-transfection of the subunit cdnas, one of which was tandem affinity purification (tap)-tagged, into human cells. the intracellular polymerase complexes were purified by the tap approach, involving two affinity chromatography steps, igg-sepharose and calmodulin-agarose. gel-filtration analysis indic ... | 2008 | 18198383 |
| interaction of polymerase subunit pb2 and np with importin alpha1 is a determinant of host range of influenza a virus. | we have previously reported that mutations in the polymerase proteins pb1, pb2, pa, and the nucleocapsid protein np resulting in enhanced transcription and replication activities in mammalian cells are responsible for the conversion of the avian influenza virus sc35 (h7n7) into the mouse-adapted variant sc35m. we show now that adaptive mutations d701n in pb2 and n319k in np enhance binding of these proteins to importin alpha1 in mammalian cells. enhanced binding was paralleled by transient nucle ... | 2008 | 18248089 |
| effectiveness of oseltamivir treatment among children with influenza a or b virus infections during four successive winters in niigata city, japan. | oseltamivir has been used for treatment of influenza a and b infections, but recent reports documented that it was less active against the latter. we compared the effectiveness of oseltamivir in children between laboratory confirmed influenza a and b over 4 influenza seasons from 2001 to 2005 in a pediatric clinic in japan. among 1,848 patients screened, 299 influenza a and 209 influenza b patients were administered oseltamivir (treated groups), and 28 influenza a and 66 influenza b patients wer ... | 2008 | 18285668 |
| development of a multiplex real-time polymerase chain reaction for the detection of influenza virus type a including h5 and h9 subtypes. | avian influenza viruses (aivs) are endemic in wild birds and, if transmitted to poultry, can cause serious economic losses. the aim of this study was to develop a multiplex real-time reverse transcriptase polymerase chain reaction (rt-pcr) for rapid detection of influenza virus type a, including h5 and h9 subtypes. the selected primers and various labeled taqman reporter probes corresponding to matrix, h5, and h9 genes were used in a multiplex real-time rt-pcr to simultaneously detect triple flu ... | 2008 | 18296004 |
| np, pb1, and pb2 viral genes contribute to altered replication of h5n1 avian influenza viruses in chickens. | the virulence determinants for highly pathogenic avian influenza viruses (aivs) are considered multigenic, although the best characterized virulence factor is the hemagglutinin (ha) cleavage site. the capability of influenza viruses to reassort gene segments is one potential way for new viruses to emerge with different virulence characteristics. to evaluate the role of other gene segments in virulence, we used reverse genetics to generate two h5n1 recombinant viruses with differing pathogenicity ... | 2008 | 18305037 |
| orthomyxo-, paramyxo- and flavivirus infections in wild waterfowl in finland. | screening wild birds for viral pathogens has become increasingly important. we tested a screening approach based on blood and cloacal and tracheal swabs collected by hunters to study the prevalence of influenza a, paramyxo-, flavi-, and alphaviruses in finnish wild waterfowl, which has been previously unknown. we studied 310 blood samples and 115 mixed tracheal and cloacal swabs collected from hunted waterfowl in 2006. samples were screened by rt-pcr and serologically by hemagglutination inhibit ... | 2008 | 18307758 |
| associations between pathogens in healthy pigs and pigs with pneumonia. | the aim of this study was to evaluate the associations between different pathogens in the development of pneumonia and bronchopneumonia in pigs. samples of bronchoalveolar lavage fluid from 100 pigs showing no clinical signs and 239 pigs with clinical signs of respiratory disease were examined for mycoplasma hyopneumoniae, mycoplasma hyorhinis, us-type porcine respiratory and reproductive syndrome virus (prrsv), eu-type prrsv, porcine circovirus type 2 (pcv-2), influenza virus type a, alpha-haem ... | 2008 | 18310558 |
| identification of human-to-human transmissibility factors in pb2 proteins of influenza a by large-scale mutual information analysis. | the identification of mutations that confer unique properties to a pathogen, such as host range, is of fundamental importance in the fight against disease. this paper describes a novel method for identifying amino acid sites that distinguish specific sets of protein sequences, by comparative analysis of matched alignments. the use of mutual information to identify distinctive residues responsible for functional variants makes this approach highly suitable for analyzing large sets of sequences. t ... | 2008 | 18315849 |
| comparison of the seeplex reverse transcription pcr assay with the r-mix viral culture and immunofluorescence techniques for detection of eight respiratory viruses. | this study evaluated the clinical usefulness of a newly introduced multiplex reverse transcription pcr assay (seeplex rv; seegene, inc., seoul, korea) in patients with respiratory symptoms. fifty clinical respiratory specimens (45 from children, 5 from adults) were tested for 8 viruses (influenza virus type a and b, parainfluenza virus type 1, 2, 3, respiratory syncytial virus type a and b, and adenovirus) by seeplex rv (s-rv) and r-mix viral culture with immunofluorescence (vc-if). forty (80%) ... | 2008 | 18316781 |
| inhibition of influenza a h3n8 virus infections in mice by morpholino oligomers. | new methods to combat influenza a virus (fluav) in humans and animals are needed. the h3n8 subtype virus was the cause of the pandemic of 1890 and has recently undergone cross-species transmission from horses to dogs in the usa. in 2007 h3n8 spread to australia, a continent previously devoid of equine influenza. here, we show that antisense-peptide-conjugated phosphorodiamidate morpholino oligomers (ppmos), delivered by intranasal administration, are able to inhibit the replication of fluav a/eq ... | 2008 | 18369525 |
| the epidemiology and antigenic characterization of influenza viruses isolated in curitiba, south brazil. | several studies conducted all over the world have reported that the influenza virus is associated with great morbidity and mortality rates. in this study, we analyzed the incidence of the influenza virus between 2000 and 2003 in curitiba. we studied 1621 samples obtained from outpatients and hospitalized patients of both sexes and all ages. the study was conducted at the local primary care health units (outpatients) and at the tertiary care unit (hospitalized) of the general hospital of the fede ... | 2008 | 18425270 |
| novel linear dna vaccines induce protective immune responses against lethal infection with influenza virus type a/h5n1. | vaccine development for possible influenza pandemics has been challenging. conventional vaccines such as inactivated and live attenuated virus preparations are limited in terms of production speed and capacity. dna vaccination has emerged as a potential alternative to conventional vaccines against influenza pandemics. in this study, we use a novel, cell-free dna manufacturing process (syndna) to produce prototype linear dna vaccines against the influenza virus type a/h5n1. this syndna process do ... | 2008 | 18443425 |
| limited compatibility between the rna polymerase components of influenza virus type a and b. | reassortants between type a and b influenza viruses have not been detected in nature, although both viruses co-circulate in human populations. one explanation for this may be functional incompatibility of rna transcription and replication between type a and b viruses. to test this possibility, we constructed type a/b mosaic polymerase machinery, containing pb2, pb1, pa and nucleoprotein from each of the two virus types, and assessed their polymerase activities with a type a promoter in a reporte ... | 2008 | 18455827 |
| simplified recombinational approach for influenza a virus reverse genetics. | influenza a virus (fluav) reverse genetics requires the cloning of all eight viral genome segments into genomic expression plasmids using restriction enzyme cleavage and ligation. herein is described the construction of a pair of plasmid vectors and their use in reca escherichia coli for direct recombination with influenza cdna for reverse genetics. this approach is simpler; avoiding restriction digestion and ligation while maintaining the required orientation of genome segments. for this recomb ... | 2008 | 18456344 |
| virion disruption by ozone-mediated reactive oxygen species. | it is well documented in the scientific literature that ozone-oxygen mixtures inactivate microorganisms including bacteria, fungi and viruses (hoff, j.c., 1986. inactivation of microbial agents by chemical disinfectants. epa 600 s2-86 067. office of water, u.s. environmental protection agency, washington, dc; khadre, m.a., yousef, a.e., kim, j.-g., 2001. microbiological aspects of ozone applications in food: a review. j. food sci. 66, 1242-1252). in the current study, delivery and absorption of ... | 2008 | 18598719 |
| simultaneous detection of different respiratory virus by a multiplex reverse transcription polymerase chain reaction combined with flow-through reverse dot blotting assay. | cell culture and immunofluorescence (if) assays have been traditionally used for the laboratory diagnosis of respiratory viral infections, but these assays have a low sensitivity and are time consuming. we developed a multiplex reverse transcription polymerase chain reaction combined with flow-through reverse dot blotting (mrt-pcr-ft-rdb) assay for the simultaneous detection of influenza virus type a including h5 subtype and h9 subtype, influenza virus type b, parainfluenza virus types 1 and 3, ... | 2008 | 18639996 |
| detection of influenza virus types a and b and type a subtypes (h1, h3, and h5) by multiplex polymerase chain reaction. | infections with influenza virus type a and b present serious public health problems on a global scale. however, only influenza a virus has been reported to cause fatal pandemic in many species. to provide suitable clinical management and prevent further virus transmission, efficient and effective clinical diagnosis is essential. therefore, we developed multiplex pcr assays for detecting influenza types a and b and the subtypes of influenza a virus (h1, h3 and h5). upon performing multiplex pcr a ... | 2008 | 18648185 |
| avian influenza in wild waterfowl and shorebirds in the donana national park: serological survey using the enzyme-linked immunosorbent assay. | the indirect elisa was used to detect antibodies to influenzavirus a in the sera of wildfowl from the donana national park. of the 712 birds examined, 44 (6.2%) were seropositive. positive birds belonged to 10 of the 13 species studied. infection rates varied widely: spoonbill (platalea leucorodia, 32.2%), mallard (anas platyrhynchos, 9.9%), gadwall (anas strepera, 8.6%), red-crested pochard (netta rufina, 8.1%), pochard (aythya ferina, 6.4%), shoveler (anas clypeata, 5%), great crested grebe (p ... | 1994 | 18671098 |
| single-chain intracellular antibodies inhibit influenza virus replication by disrupting interaction of proteins involved in viral replication and transcription. | influenza a virus is responsible for influenza epidemics in avian and human populations and poses a great threat to human health. many researches have been focused on the prevention and treatment of influenza a virus infection. the nucleoprotein (np) of the virus is an important protein due to its ability to interact with a variety of viral and cellular factors and its role in the viral rna synthesis. in this study, we have used the influenza a virus nucleoprotein as target for anti-viral therap ... | 2009 | 18687409 |
| an inhibitory activity in human cells restricts the function of an avian-like influenza virus polymerase. | transmission of avian influenza virus into human populations has the potential to cause pandemic outbreaks. a major determinant of species tropism is the identity of amino acid 627 in the pb2 subunit of the heterotrimeric influenza polymerase; glutamic acid predominates in avian pb2, whereas lysine occupies this position in human isolates. we show that a dominant inhibitory activity in human cells potently and selectively restricts the function of polymerases containing an avian-like pb2 with gl ... | 2008 | 18692771 |
| [influenza in poland in 2006]. | a total number of 251,815 cases of influenza and influenza-like illness registered in poland in 2006 (incidence 660.4 per 100,000 population). regionally the incidence varied from 75.6 per 100,000 in swietokrzyskie voivodeship to 1,690.4 in mazowieckie. the highest reported incidence was observed in age group 0-4 years (1,543.1 per 100,000). children and adolescents under 15 years of age accounted for 34.3% of all cases (age specific incidence 1,434.8 per 100,000). in this age group the incidenc ... | 2008 | 18807463 |
| antiviral effects of ascorbic and dehydroascorbic acids in vitro. | in the present study, ascorbic acid weakly inhibited the multiplication of viruses of three different families: herpes simplex virus type 1 (hsv-1), influenza virus type a and poliovirus type 1. dehydroascorbic acid, an oxidized form of ascorbic acid and hence without reducing ability, showed much stronger antiviral activity than ascorbic acid, indicating that the antiviral activity of ascorbic acid is due to factors other than an antioxidant mechanism. moreover, addition of 1 mm fe3+, which oxi ... | 2008 | 18813862 |
| [common viral etiologies of community acquired lower respiratory tract infections in young children and their relationship with long term complications]. | viral lower respiratory tract infections (lrtis) and their late complications are important causes of morbidity and mortality in childhood. the aims of this study were the detection of viral agents that cause community-acquired lrtis in young children and investigation of the relationship between viral etiology and bronchiolitis obliterans (bo) which is one of the late complications of lrtis. a total of 151 children (86 male, 65 female; mean age: 2.9 +/- 1.9 years) who were diagnosed to have lrt ... | 2008 | 18822886 |
| experimental evolution of human influenza virus h3 hemagglutinin in the mouse lung identifies adaptive regions in ha1 and ha2. | the genetic basis for virulence and host switching in influenza a viruses (fluav) is largely unknown. because the hemagglutinin (ha) protein is a determinant of these properties, ha evolution was mapped in an experimental model of mouse lung adaptation. variants of prototype a/hong kong/1/68 (h3n2) (wild-type [wt] hk) human virus were selected in both longitudinal and parallel studies of lung adaptation. mapping of ha mutations found in 11 independently derived mouse-adapted populations of wt hk ... | 2008 | 18829764 |
| rapid typing, subtyping and rna quantification of influenza virus type a strains in respiratory secretions. | during the winter-spring season 2006-2007, 38 influenza virus strains were identified in patients admitted to hospital with an acute respiratory tract infection. infections were diagnosed in parallel by direct fluorescent antibody (dfa) staining using type-specific monoclonal antibodies and real-time reverse transcription (rt)-pcr targeting the gene m (nt 25-124). in addition, virus strains were isolated in mdck cells. overall, 37 influenza virus strains were type a, and one type b. of these, 35 ... | 2008 | 18843885 |
| co-operative thermal inactivation of herpes simplex virus and influenza virus by arginine and nacl. | elevated temperatures have been used to inactivate viruses for plasma-derived biopharmaceuticals. this paper describes the effects of arginine and nacl in conjunction with elevated temperature for inactivation of two enveloped viruses, i.e., herpes simplex virus type 1 (hsv-1) and influenza virus type a at neutral ph. in phosphate-buffered saline, a significant inactivation of hsv-1 occurred above 40 degrees c, resulting in less than 10% surviving virus (over 90% virus inactivation) at 50 degree ... | 2009 | 18845231 |
| in vitro anti-influenza screening of several euphorbiaceae species: structure of a bioactive cyanoglucoside from codiaeum variegatum. | a bio-guided screening against influenza a virus (fluav) was carried out with seven euphorbiaceae species. the results showed that chromatographic fractions from phyllantus niruri, euphorbia pulcherrima and codiaeum variegatum had relevant anti-fluav activity, although only chromatographical subfractions from c. variegatum kept the activity. from this plant, the active compound against fluav was isolated. its structure was assigned as 2-(3,4,5)-trihydroxy-6-hydroxymethyltetrahydropyran-2-yloxyme ... | 2008 | 18851862 |
| anti-influenza virus activity of myrica rubra leaf ethanol extract evaluated using madino-darby canine kidney (mdck) cells. | myrica rubra leaf ethanol extract was added to culture medium of madino-darby canine kidney (mdck) cells inoculated with influenza virus, and the inhibition of influenza virus replication was measured. myrica rubra leaf ethanol extract showed anti-influenza virus activity irrespective of the hemagglutinin antigen type in the influenza virus type a (h1n1), its subtype (h3n2), and type b. | 2008 | 18997411 |
| the human h5n1 influenza a virus polymerase complex is active in vitro over a broad range of temperatures, in contrast to the wsn complex, and this property can be attributed to the pb2 subunit. | influenza a virus (iav) replicates in the upper respiratory tract of humans at 33 degrees c and in the intestinal tract of birds at close to 41 degrees c. the viral rna polymerase complex comprises three subunits (pa, pb1 and pb2) and plays an important role in host adaptation. we therefore developed an in vitro system to examine the temperature sensitivity of iav rna polymerase complexes from different origins. complexes were prepared from human lung epithelial cells (a549) using a novel adenov ... | 2008 | 19008377 |
| activation of the antiviral prodrug oseltamivir is impaired by two newly identified carboxylesterase 1 variants. | oseltamivir phosphate is an ethyl ester prodrug widely used in the treatment and prevention of both influenzavirus a and b infections. the conversion of oseltamivir to its active metabolite oseltamivir carboxylate is dependent on ester hydrolysis mediated by carboxylesterase 1 (ces1). we recently identified two functional ces1 variants p.gly143glu and p.asp260fs in a research subject who displayed significant impairment in his ability to metabolize the selective ces1 substrate, methylphenidate. ... | 2009 | 19022936 |
| influenza a virus polymerase is an integral component of the cpsf30-ns1a protein complex in infected cells. | the ns1a protein of influenza a virus binds the cellular cpsf30 protein, thereby inhibiting the 3'-end processing of all cellular pre-mrnas, including beta interferon pre-mrna. x-ray crystallography identified the cpsf30-binding pocket on the influenza virus a/udorn/72 (ud) ns1a protein and the critical role of two hydrophobic ns1a amino acids outside the pocket, f103 and m106, in stabilizing the cpsf30-ns1a complex. although the ns1a protein of the 1997 h5n1 influenza a/hong kong/483/97 (hk97) ... | 2009 | 19052083 |
| pb2 protein of a highly pathogenic avian influenza virus strain a/chicken/yamaguchi/7/2004 (h5n1) determines its replication potential in pigs. | it has been shown that not all but most of the avian influenza viruses replicate in the upper respiratory tract of pigs (h. kida et al., j. gen. virol. 75:2183-2188, 1994). it was shown that a/chicken/yamaguchi/7/2004 (h5n1) [ck/yamaguchi/04 (h5n1)] did not replicate in pigs (n. isoda et al., arch. virol. 151:1267-1279, 2006). in the present study, the genetic basis for this host range restriction was determined using reassortant viruses generated between ck/yamaguchi/04 (h5n1) and a/swine/hokka ... | 2009 | 19052090 |
| genetic analysis of h3 subtype influenza viruses isolated from domestic ducks in northern china during 2004-2005. | the broad distribution and prevalence of h3 subtype influenza viruses in avian and mammalian hosts constitutes a global threat to both human and veterinary health. in this present study, six h3n8 influenza viruses isolated from domestic ducks during 2004-2005 in northern china were genetically and phylogenetically characterized. sequence analysis showed that ha, na, and m genes of all the six h3n8 isolates had a close relationship with those of equine/jilin/1/89 (h3n8) virus, which once caused o ... | 2009 | 19067150 |
| live attenuated influenza viruses containing ns1 truncations as vaccine candidates against h5n1 highly pathogenic avian influenza. | due to the high mortality associated with recent, widely circulating strains of h5n1 influenza virus in poultry, the recurring introduction of h5n1 viruses from birds to humans, and the difficulties in h5n1 eradication by elimination of affected flocks, an effective vaccine against hpai (highly pathogenic avian influenza) is highly desirable. using reverse genetics, a set of experimental live attenuated vaccine strains based on recombinant h5n1 influenza virus a/viet nam/1203/04 was generated. e ... | 2009 | 19073731 |
| transmission of influenza virus in a mammalian host is increased by pb2 amino acids 627k or 627e/701n. | since 2003, more than 380 cases of h5n1 influenza virus infection of humans have been reported. although the resultant disease in these cases was often severe or fatal, transmission of avian influenza viruses between humans is rare. the precise nature of the barrier blocking human-to-human spread is unknown. it is clear, however, that efficient human-to-human transmission of an antigenically novel influenza virus would result in a pandemic. influenza viruses with changes at amino acids 627 or 70 ... | 2009 | 19119420 |
| factors responsible for plaque formation of a/duck/siberia/272/1998 (h13n6) influenza virus on mdck cells. | many influenza a viruses form plaques on madin-darby canine kidney (mdck) cells in the presence of trypsin. a/duck/siberia/272/1998 (h13n6) (sib272), however, does not form plaque on mdck cells. after three blind passages of the strain on mdck cells, plaque-forming variant was obtained and designated as a/duck/siberia/272pf/1998 (h13n6) (sib272pf). genetic and functional analyses of sib272 and sib272pf revealed that amino acid substitutions, f3l of the ha2 subunit and t379k of the pb1, were resp ... | 2009 | 19146891 |
| real-time rt-pcr for detection of equine influenza and evaluation using samples from horses infected with a/equine/sydney/2007 (h3n8). | equine influenza (ei) virus (h3n8) was identified in the australian horse population for the first time in august 2007. the principal molecular diagnostic tool used for detection was a taqman real-time reverse transcription-polymerase chain reactions (rt-pcr) assay specific for the matrix (ma) gene of influenza virus type a (iva). as this assay is not specific for ei, we developed a new ei h3-specific taqman assay targeting the haemagglutinin (ha) gene of all recent ei h3 strains. the iva and th ... | 2009 | 19153018 |
| comparison of automated microarray detection with real-time pcr assays for detection of respiratory viruses in specimens obtained from children. | respiratory virus infections are a major health concern and represent the primary cause of testing consultation and hospitalization for young children. we developed and compared two assays that allow the detection of up to 23 different respiratory viruses that frequently infect children. the first method consisted of single taqman quantitative real-time pcr assays in a 96-well-plate format. the second consisted of a multiplex pcr followed by primer extension and microarray hybridization in an in ... | 2009 | 19158263 |
| human ha and polymerase subunit pb2 proteins confer transmission of an avian influenza virus through the air. | the influenza virus genes that confer efficient transmission of epidemic and pandemic strains in humans have not been identified. the rapid spread and severe disease caused by the 1918 influenza pandemic virus makes it an ideal virus to study the transmissibility of potentially pandemic influenza strains. here, we used a series of human 1918-avian h1n1 influenza reassortant viruses to identify the genetic determinants that govern airborne transmission of avian influenza viruses. we have demonstr ... | 2009 | 19211790 |
| physicochemical and immunological characterization of n,n,n-trimethyl chitosan-coated whole inactivated influenza virus vaccine for intranasal administration. | the purpose of this study was the development and physicochemical and immunological characterization of intranasal (i.n.) vaccine formulations of whole inactivated influenza virus (wiv) coated with n,n,n-trimethyl chitosan (tmc). | 2009 | 19224344 |
| selection of h5n1 influenza virus pb2 during replication in humans. | highly pathogenic h5n1 influenza viruses continue to cause concern, even though currently circulating strains are not efficiently transmitted among humans. for efficient transmission, amino acid changes in viral proteins may be required. here, we examined the amino acids at positions 627 and 701 of the pb2 protein. a direct analysis of the viral rnas of h5n1 viruses in patients revealed that these amino acids contribute to efficient virus propagation in the human upper respiratory tract. viruses ... | 2009 | 19264775 |
| early control of h5n1 influenza virus replication by the type i interferon response in mice. | widespread distribution of highly pathogenic avian h5n1 influenza viruses in domesticated and wild birds continues to pose a threat to public health, as interspecies transmission of virus has resulted in increasing numbers of human disease cases. although the pathogenic mechanism(s) of h5n1 influenza viruses has not been fully elucidated, it has been suggested that the ability to evade host innate responses, such as the type i interferon response, may contribute to the virulence of these viruses ... | 2009 | 19297490 |
| oligonucleotides derived from the packaging signal at the 5' end of the viral pb2 segment specifically inhibit influenza virus in vitro. | the development of new antiviral molecules to fight the possible emergence of influenza viruses with pandemic potential is needed. in this study, phosphorothioate oligonucleotides (s-ons) derived from the packaging signals in the 3' and 5' ends of the viral pb2 rna were associated with liposomes and tested against influenza virus in vitro. a 15-mer s-on derived from the 5' end of the viral pb2 rna, complementary to the 3' end of its coding region (nucleotides 2279-2293) and designated 5-15b, pro ... | 2009 | 19370391 |
| single mutation at the amino acid position 627 of pb2 that leads to increased virulence of an h5n1 avian influenza virus during adaptation in mice can be compensated by multiple mutations at other sites of pb2. | to understand the adaptation of h5n1 influenza viruses to mammals, a non-pathogenic influenza h5n1 virus (hn021) in mice was passaged for 15 times in mammalian host. animal experimental results indicated that the mouse-adapted (ma) variants became highly pathogenic in mice after the passages. sequence analysis showed that there was one amino acid substitution in pb2 protein of ma mutants after first passage (ma1), three amino acid substitutions in pb2 protein of ma5 and one amino acid in m1 prot ... | 2009 | 19393699 |
| cold oxygen plasma technology efficiency against different airborne respiratory viruses. | respiratory infections caused by viruses are major causes of upper and lower respiratory tract infections. they account for an important mortality and morbidity worldwide. amongst these viruses, influenza viruses and paramyxoviruses are major pathogens. their transmission is mainly airborne, by direct transmission through droplets from infected cases. | 2009 | 19406687 |
| different neuraminidase inhibitor susceptibilities of human h1n1, h1n2, and h3n2 influenza a viruses isolated in germany from 2001 to 2005/2006. | in the flu season 2005/2006 amantadine-resistant human influenza a viruses (fluav) of subtype h3n2 circulated in germany. this raises questions on the neuraminidase inhibitor (nai) susceptibility of fluav. to get an answer, chemiluminescence-based neuraminidase inhibition assays were performed with 51 h1n1, h1n2, and h3n2 fluav isolated in germany from 2001 to 2005/2006. according to the mean ic(50) values (0.38-0.91 nm for oseltamivir and 0.76-1.13 nm for zanamivir) most h1n1 and h3n2 fluav wer ... | 2009 | 19428593 |
| full factorial analysis of mammalian and avian influenza polymerase subunits suggests a role of an efficient polymerase for virus adaptation. | amongst all the internal gene segments (pb2. pb1, pa, np, m and ns), the avian pb1 segment is the only one which was reassorted into the human h2n2 and h3n2 pandemic strains. this suggests that the reassortment of polymerase subunit genes between mammalian and avian influenza viruses might play roles for interspecies transmission. to test this hypothesis, we tested the compatibility between pb2, pb1, pa and np derived from a h5n1 virus and a mammalian h1n1 virus. all 16 possible combinations of ... | 2009 | 19462010 |
| protective role for protease-activated receptor-2 against influenza virus pathogenesis via an ifn-gamma-dependent pathway. | protease-activated receptor-2 (par(2)), a receptor highly expressed in the respiratory tract, can influence inflammation at mucosal surfaces. although the effects of par(2) in the innate immune response to bacterial infection have been documented, knowledge of its role in the context of viral infection is lacking. we thus investigated the role of par(2) in influenza pathogenesis in vitro and in vivo. in vitro, stimulation of par(2) on epithelial cells inhibited influenza virus type a (iav) repli ... | 2009 | 19494303 |
| pathogenesis of infectious disease of mice caused by h5n1 avian influenza virus. | the pathogenesis of a disease caused by qinghai-like h5n1 influenza virus in balb/c mice was studied. clinical, morphological, and immunological characteristics of the experimental infection caused by highly pathogenic a/duck/tuva/01/06/ (h5n1) virus are described. | 2008 | 19513379 |
| characterization of the h5n1 highly pathogenic avian influenza virus derived from wild pikas in china. | the highly pathogenic h5n1 avian influenza virus emerged from china in 1996 and has spread across eurasia and africa, with a continuous stream of new cases of human infection appearing since the first large-scale outbreak among migratory birds at qinghai lake. the role of wild birds, which are the natural reservoirs for the virus, in the epidemiology of the h5n1 virus has raised great public health concern, but their role in the spread of the virus within the natural ecosystem of free-ranging te ... | 2009 | 19553321 |
| poly-silicon nanowire field-effect transistor for ultrasensitive and label-free detection of pathogenic avian influenza dna. | enhanced surveillance of influenza requires rapid, robust, and inexpensive analytical techniques capable of providing a detailed analysis of influenza virus strains. functionalized poly-crystalline silicon nanowire field-effect transistor (poly-sinw fet) was demonstrated to achieve specific and ultrasensitive (at fm level) detection of high pathogenic strain virus (h5 and h7) dna of avian influenza (ai) which is an important infectious disease and has an immediate need for surveillance. the poly ... | 2009 | 19362813 |
| immunosuppressive hla-g molecule is upregulated in alveolar epithelial cells after influenza a virus infection. | influenza virus type a (iav) infections constitute an important economic burden and raise health-care problems. host defense mechanisms usually clear iav infections after a few days by exploiting a variety of cellular immune responses. however, increasing the production of immunosubversive molecules is a mechanism by which viruses escape host surveillance. in this regard, the nonclassical hla class i molecule hla-g displays strong tolerogenic properties. we show here that several strains of iav ... | 2009 | 19664669 |
| [construction of recombinant adenovirus co-expressing m1 and ha genes of influenza virus type a]. | based on the human h5n1 influenza virus strain a/anhui/1/2005, recombinant adenovirus co-expressing m1 and ha genes of h5n1 influenza virus was constructed using an internal ribosome entry site (ires) sequence to link the two genes. the m1 and ha genes of h5n1 influenza virus were amplified by pcr and subcloned into pstar vector separately. then the m1-ires-ha fragment was amplified and subcloned into pshuttle-cmv vector, the shuttle plasmid was then linearized and transformed into bj5183 bacter ... | 2009 | 19678564 |
| influenza a virus lacking m2 protein as a live attenuated vaccine. | mutant influenza virus that lacks the transmembrane and cytoplasmic tail domains of m2 (m2 knockout [m2ko]) is attenuated in both cell culture and mice. here, we examined the potency of m2ko influenza virus as a live attenuated influenza vaccine. m2ko virus grew as efficiently as the wild-type virus in cells stably expressing the wild-type m2, indicating the feasibility of efficient vaccine production. mice intranasally vaccinated with m2ko virus developed protective immune responses and survive ... | 2009 | 19321619 |
| crystallization and x-ray diffraction analysis of the rna primer/promoter-binding domain of influenza a virus rna-dependent rna polymerase pb2. | the c-terminal domain protein (amino-acid residues 535-759) of the pb2 subunit of the rna-dependent rna polymerase from the highly pathogenic influenza a virus was expressed as a soluble protein in escherichia coli and crystallized using sodium formate as a precipitant. data sets were collected from crystals of native and selenomethionine-substituted protein on the kek nw12 beamline at the photon factory and the crystals diffracted to a maximum resolution of 2.44 a for the semet-derivative cryst ... | 2009 | 19194006 |
| 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 |
| detection and characterization of influenza a virus pa-pb2 interaction through a bimolecular fluorescence complementation assay. | the influenza virus polymerase complex, consisting of the pa, pb1, and pb2 subunits, is required for the transcription and replication of the influenza a viral genome. previous studies have shown that pb1 serves as a core subunit to incorporate pa and pb2 into the polymerase complex by directly interacting with pa and pb2. despite numerous attempts, largely involving biochemical approaches, a specific interaction between pa and pb2 subunits has yet to be detected. in the current study, we develo ... | 2009 | 19193801 |
| [in vitro experimental study on the effect of resveratrol against several kinds of respiroviruses]. | to observe the cytopathogenic inhibitory effect of resveratrol on vary respiroviruses and explore the mechanism of resveratrol against viruses. | 2008 | 19180966 |
| start of the influenza season 2008-9 in europe - increasing influenza activity moving from west to east dominated by a(h3n2). | the influenza season 2008-9 started in week 49 of 2008 and is so far characterised by influenza virus type a subtype h3n2. isolates of this subtype that were tested proved susceptible to neuraminidase inhibitors, but resistant to m2 inhibitors. the circulating a(h3n2) viruses are antigenically similar to the component in the current northern hemisphere influenza vaccine. | 2009 | 19161722 |
| 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 |
| structural basis of the influenza a virus rna polymerase pb2 rna-binding domain containing the pathogenicity-determinant lysine 627 residue. | because the influenza a virus has an rna genome, its rna-dependent rna polymerase, comprising the pa, pb1, and pb2 subunits, is essential for viral transcription and replication. the binding of rna primers/promoters to the polymerases is an initiation step in viral transcription. in our current study, we reveal the 2.7 a tertiary structure of the c-terminal rna-binding domain of pb2 by x-ray crystallography. this domain incorporates lysine 627 of pb2, and this residue is associated with the high ... | 2009 | 19144639 |
| influenza sequence and epitope database. | influenza epidemics arise through the acquisition of viral genetic changes to overcome immunity from previous infections. an increasing number of complete genomes of influenza viruses have been sequenced in asia in recent years. knowledge about the genomes of the seasonal influenza viruses from different countries in asia is valuable for monitoring and understanding of the emergence, migration and evolution of strains. in order to make full use of the wealth of information from such data, we hav ... | 2009 | 19015128 |
| 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 |
| interaction of the influenza a virus nucleocapsid protein with the viral rna polymerase potentiates unprimed viral rna replication. | the influenza a virus polymerase transcribes and replicates the eight virion rna (vrna) segments. transcription is initiated with capped rna primers excised from cellular pre-mrnas by the intrinsic endonuclease of the viral polymerase. viral rna replication occurs in two steps: first a full-length copy of vrna is made, termed crna, and then this crna is copied to produce vrna. the synthesis of crnas and vrnas is initiated without a primer, in contrast to the initiation of viral mrna synthesis, a ... | 2009 | 18945782 |
| 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 |
| antibody responses after inactivated influenza vaccine in young children. | the frequency and duration of antibody responses after trivalent inactivated influenza vaccine (tiv) in young children are not well defined and assume greater importance with the expanded recommendations for vaccine use in children aged 6 months-5 years. | 2008 | 18833023 |
| [effects of qiulirunfei extracta on immunological function and influenza virus in mice]. | to investigate the effect of qiulirunfei extracta on immunological function and influenza virus type a (fm1 strain) in icr mice. | 2008 | 18661831 |