Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| serologic survey of potential vertebrate hosts for west nile virus in poland. | a survey for antibodies to west nile virus (wnv; genus ,flavivirus) was carried out by plaque-re-duction neutralization microtesting in 78 horses, 20 domestic chickens, and 97 wild birds belonging to 10 species from different areas in poland. specific antibodies were detected in five juvenile (hatching-year) birds collected in 2006: three white storks (ciconia ciconia) in a wildlife rehabilitation center (5.4% of all examined storks; the antibody titers in each bird were 1:320, 1:160, and 1:20), ... | 2008 | 18433332 |
| construction and evaluation of a chimeric pseudoinfectious virus vaccine to prevent japanese encephalitis. | multiple vaccines exist to control japanese encephalitis (je), but all suffer from problems. we have developed a new type of flavivirus vaccine, a pseudoinfectious virus (replivax wn) that prevents west nile virus (wnv)-induced disease. here, we describe production of a chimeric replivax (replivax je) that expresses the je virus (jev) prm and e proteins. our prototype replivax je replicated poorly in cells, but blind passage produced a better-growing derivative, and analyses of this derivative a ... | 2008 | 18433947 |
| modulation of signaling pathways by rna virus capsid proteins. | capsid proteins are structural components of virus particles. they are nucleic acid-binding proteins whose main recognized function is to package viral genomes into protective structures called nucleocapsids. research over the last 10 years indicates that in addition to their role as genome guardians, viral capsid proteins modulate host cell signaling networks. disruption or alteration of intracellular signaling pathways by viral capsids may benefit replication of the virus by affecting innate i ... | 2008 | 18258415 |
| pathogenic flaviviruses. | haemorrhagic disease, encephalitis, biphasic fever, flaccid paralysis, and jaundice are typical manifestations of diseases in human beings after infections by mosquito-borne or tick-borne flaviviruses such as yellow fever, dengue, west nile, st louis encephalitis, japanese encephalitis, tick-borne encephalitis, kyasanur forest disease, and omsk haemorrhagic fever. although the characteristics of these viruses are well defined, they are still unpredictable with increases in disease severity, unus ... | 2008 | 18262042 |
| a survey on cases of tick-borne encephalitis in european countries. | the european network for diagnostics of "imported" viral diseases (enivd) is finalising a project to improve the diagnostic and monitoring of encephalitis viruses in europe. part of this study was to analyse the present surveillance situation for tick-borne encephalitis (tbe), which is the most important flavivirus infection of the central nervous system in the european union (eu) and russia. a questionnaire was mailed to contact points in all member states of the eu and three non-eu countries ( ... | 2008 | 18445446 |
| evaluation of recombinant kunjin replicon siv vaccines for protective efficacy in macaques. | persistent gag-specific t cell immunity would be a useful component of an effective hiv vaccine. the flavivirus kunjin replicon was previously engineered to persistently express hiv gag and was shown to induce protective responses in mice. we evaluated kunjin replicon virus-like-particles expressing sivgag-pol in pigtail macaques. kunjin-specific antibodies were induced, but no siv-specific t cell immunity were detected. following sivmac251 challenge, there was no difference in siv viremia or re ... | 2008 | 18272194 |
| mutations in the ns2b and ns3 genes affect mouse neuroinvasiveness of a western european field strain of tick-borne encephalitis virus. | an attenuated strain (263) of the tick-borne encephalitis virus, isolated from field ticks, was either serially subcultured, 5 times in mice, or at 40 degrees c in ps cells, producing 2 independent strains, 263-m5 and 263-tr with identical genomes; both strains exhibited increased plaque size, neuroinvasiveness and temperature-resistance. sequencing revealed two unique amino acid substitutions, one mapping close to the catalytic site of the viral protease. these observations imply that virus ada ... | 2008 | 18339416 |
| structure-based mutagenesis identifies important novel determinants of the ns2b cofactor of the west nile virus two-component ns2b-ns3 proteinase. | west nile virus (wnv) is an emerging mosquito-borne flavivirus that causes neuronal damage in the absence of treatment. in many flaviviruses, including wnv, the ns2b cofactor promotes the productive folding and the functional activity of the two-component ns3 (pro)teinase. based on an analysis of the ns2b-ns3pro structure, we hypothesized that the g(22) residue and the negatively charged patch d(32)dd(34) of ns2b were part of an important configuration required for ns2b-ns3pro activity. our expe ... | 2008 | 18272753 |
| considerations for accurate identification of adult culex restuans (diptera: culicidae) in field studies. | understanding the ecology and behavior of different mosquito species (diptera: culicidae) is essential for identifying their role in disease transmission cycles and public health risk. two species of culex mosquitoes in the northeastern united states, culex pipiens l. and culex restuans theobald, have been implicated in enzootic transmission of west nile virus (family flaviviridae, genus flavivirus, wnv). despite the difficulty of differentiating these two species as adults, many public health w ... | 2008 | 18283935 |
| characterization of asn130-to-ala mutant of dengue type 1 virus ns1 protein. | the nonstructural protein 1 (ns1) of flavivirus has two n-glycosylation sites that are thought to be important for viral replication. effects of ns1 glycosylation site mutations on viral replication have been reported in several flaviviruses, but the results have differed. in this report, we examined the role of glycosylation site of ns1 on the replication of dengue type 1 virus (denv-1). denv-1 production was not detectable when full-length denv-1 rna, which has an n-glycosylation site asn130-t ... | 2008 | 18288598 |
| serologic survey of birds for west nile flavivirus in southern moravia (czech republic). | a serosurvey for west nile virus (wnv) was carried out in 54 domestic birds (geese and ducks bred on fishponds) and 391 wild birds representing 28 migratory and resident species, using a plaque-reduction neutralization microtest with vero cells and egyptian topotype eg-101 strain as test virus. the birds were sampled in the south-moravian fishpond ecosystem between 2004 and 2006. antibodies to wnv were not detected in domestic waterfowl, but 23 (5.9%) free-living birds of 10 species showed a pos ... | 2008 | 18454599 |
| functional analysis of dengue virus cyclization sequences located at the 5' and 3'utrs. | flavivirus rna replication involves cyclization of the viral genome. a model for this process includes a promoter element at the 5' end of the genome and long-range rna-rna interactions. two pairs of complementary sequences present at the ends of the viral rna, known as 5'-3'cs and 5'-3'uar, have been proposed to be involved in dengue virus genome cyclization. the requirement of 5'-3'cs complementarity for viral replication has been experimentally demonstrated for dengue and other mosquito borne ... | 2008 | 18289628 |
| long-term balancing selection at the west nile virus resistance gene, oas1b, maintains transspecific polymorphisms in the house mouse. | oligoadenylate synthetases (oass) are interferon-inducible enzymes that participate in the first line of defense against a wide range of viral infection. recent studies have determined that oas1b, a member of the oas gene family in the house mouse (mus musculus), provides specific protection against flavivirus infection (e.g., west nile virus, dengue fever virus, and yellow fever virus). we characterized the nucleotide sequence variation in coding and noncoding regions of the oas1b gene for a la ... | 2008 | 18460447 |
| kunjin replicon-based simian immunodeficiency virus gag vaccines. | an rna-based, non-cytopathic replicon vector system, based on the flavivirus kunjin, has shown considerable promise as a new vaccine delivery system. here we describe the testing in mice of four different sivmac239 gag vaccines delivered by kunjin replicon virus-like-particles. the four vaccines encoded the wild type gag gene, an rna-optimised gag gene, a codon-optimised gag gene and a modified gag-pol gene construct. the vaccines behaved quite differently for induction of effector memory and ce ... | 2008 | 18462846 |
| west nile virus methyltransferase catalyzes two methylations of the viral rna cap through a substrate-repositioning mechanism. | flaviviruses encode a single methyltransferase domain that sequentially catalyzes two methylations of the viral rna cap, gpppa-rna-->m(7)gpppa-rna-->m(7)gpppam-rna, by using s-adenosyl-l-methionine (sam) as a methyl donor. crystal structures of flavivirus methyltransferases exhibit distinct binding sites for sam, gtp, and rna molecules. biochemical analysis of west nile virus methyltransferase shows that the single sam-binding site donates methyl groups to both n7 and 2'-o positions of the viral ... | 2008 | 18305027 |
| persistence of antibodies to west nile virus nonstructural protein 5. | because igm antibody against west nile virus (wnv) pre-membrane/envelope (prem/e) recombinant protein may persist for more than 1 year, an assay distinguishing recent from past wnv infection would be useful. published findings for a single patient suggest that the presence of antibody against wnv nonstructural protein 5 (ns5) indicates recent infection. | 2008 | 18467165 |
| phase 2 clinical trial of three formulations of tetravalent live-attenuated dengue vaccine in flavivirus-naïve adults. | sixteen dose formulations of our live-attenuated tetravalent dengue virus vaccines (tdv) were previously evaluated for safety and immunogenicity. two of the sixteen candidate tdv formulations (formulations 13 and 14) were selected for further evaluation. a new tdv formulation, formulation 17, using a higher primary dog kidney (pdk) cell passage dengue-1 virus (denv-1) and a lower pdk cell passage denv-4, was developed to optimize the neutralizing antibody response. all three formulations consist ... | 2009 | 18670195 |
| development of a human-murine chimeric immunoglobulin m antibody for use in the serological detection of human flavivirus antibodies. | current diagnosis of human flaviviral infections relies heavily on serological techniques such as the immunoglobulin m (igm) antibody capture enzyme-linked immunosorbent assay (mac-elisa). broad application of this assay is hindered by a lack of standardized human positive-control sera that react with the wide variety of flaviviruses that can cause human disease, e.g., dengue virus (denv), west nile virus (wnv), yellow fever virus (yfv), japanese encephalitis virus (jev), and st. louis encephali ... | 2009 | 19297614 |
| evaluation of an epitope-blocking enzyme-linked immunosorbent assay for the diagnosis of west nile virus infections in humans. | an epitope-blocking enzyme-linked immunosorbent assay (b-elisa) was evaluated for the diagnosis of west nile virus (wnv) infections in humans. sera from patients diagnosed with wnv infections from an outbreak in 2003 in colorado and from patients diagnosed with dengue virus infections from mexico and thailand were tested with the b-elisa. the b-elisas were performed using the wnv-specific monoclonal antibody (mab) 3.1112g and the flavivirus-specific mab 6b6c-1. although the wnv-specific b-elisa ... | 2009 | 19321694 |
| a replicon trans-packaging system reveals the requirement of nonstructural proteins for the assembly of bovine viral diarrhea virus (bvdv) virion. | a selective trans-packaging system was developed to produce and isolate bovine viral diarrhea virus (bvdv) pseudo-particles with complementing reporter replicons and their packaging proteins expressed in trans with recombinant vaccinia virus. the encapsidation of replicon rns3-5b was dependent not only on the in trans expression of structural proteins c, e(rns), e1 and e2, but also the nonstructural proteins, p7 and contiguous precursor ns2-3-4a. nonstructural p7, ns4b, ns5a or ns5b could be exp ... | 2009 | 19327808 |
| a kunjin replicon vector encoding granulocyte macrophage colony-stimulating factor for intra-tumoral gene therapy. | we have recently developed a non-cytopathic rna replicon-based viral vector system based on the flavivirus kunjin. here, we illustrate the utility of the kunjin replicon system for gene therapy. intra-tumoral injections of kunjin replicon virus-like particles encoding granulocyte colony-stimulating factor were able to cure >50% of established subcutaneous ct26 colon carcinoma and b16-ova melanomas. regression of ct26 tumours correlated with the induction of anti-cancer cd8 t cells, and treatment ... | 2009 | 19092857 |
| characterization of dengue complex-reactive epitopes on dengue 3 virus envelope protein domain iii. | the disease dengue (den) is caused by four genetically and serologically related viruses termed denv-1, -2, -3, and -4. the denv envelope (e) protein ectodomain can be divided into three structural domains designated ed1, ed2, and ed3. the ed3 contains the denv type-specific and denv complex-reactive (epitopes shared by denv 1-4) antigenic sites. in this study the epitopes recognized by four denv complex-reactive monoclonal antibodies (mabs) with neutralizing activity were mapped on the denv-3 e ... | 2009 | 19101005 |
| [flavivirus encephalitis]. | the member of the genus flavivirus family flaviviridae are arthropod-transmitted viruses. this genus includes vector-borne neurotropic viruses such as the tick-borne encephalitis virus serocomplex and the japanese encephalitis virus serocomplex. flavivirus encephalitis is the generic term for encephalitis caused by viruses belonging to this genus. the japanese encephalitis virus is still active in japan, and the tick-borne encephalitis virus is prevalent in hokkaido, the northern region of japan ... | 2009 | 19235464 |
| role of antibodies in controlling dengue virus infection. | the incidence and disease burden of arthropod-borne flavivirus infections have dramatically increased during the last decades due to major societal and economic changes, including massive urbanization, lack of vector control, travel, and international trade. specifically, in the case of dengue virus (denv), the geographical spread of all four serotypes throughout the subtropical regions of the world has led to larger and more severe outbreaks. many studies have established that recovery from inf ... | 2009 | 19261353 |
| tyrosine 78 of premembrane protein is essential for assembly of west nile virus. | flavivirus premembrane (prm) protein plays an important role in conformational folding of the envelope (e) protein and protects it against premature fusion in acidic vesicles of the golgi network. currently, molecular determinants on the prm protein ectodomain which mediate critical steps during the flavivirus assembly process are poorly characterized. in this study, bioinformatics analysis and alanine scanning mutagenesis showed that the amino acid triplet valine 76, tyrosine 78 and glycine 79 ... | 2009 | 19264649 |
| on a mouse monoclonal antibody that neutralizes all four dengue virus serotypes. | the flavivirus envelope glycoprotein (e) is responsible for viral attachment and entry by membrane fusion. its ectodomain is the primary target of the humoral immune response. in particular, the c-terminal ig-like domain iii of e, which is exposed at the surface of the viral particle, forms an attractive antigen for raising protective monoclonal antibodies (mab). 9f12, a mouse mab raised against a dengue virus (denv) serotype 2 recombinant domain iii, cross-reacts with corresponding domains from ... | 2009 | 19264660 |
| virus-specific cytolytic antibodies to nonstructural protein 1 of japanese encephalitis virus effect reduction of virus output from infected cells. | we demonstrate the presence of nonstructural protein 1 (ns1)-specific antibodies in a significant proportion of convalescent-phase human serum samples obtained from a cohort in an area where japanese encephalitis virus (jev) is endemic. sera containing antibodies to ns1 but not those with antibodies to other jev proteins, such as envelope, brought about complement-mediated lysis of jev-infected bhk-21 cells. target cells infected with a recombinant poxvirus expressing jev ns1 on the cell surface ... | 2009 | 19264772 |
| new drug targets for hepatitis c and other flaviviridae viruses. | the flaviviridae family comprises the genus flavivirus, hepacivirus and pestivirus. these viruses are responsible for considerable human and animal disease and mortality worldwide. flaviviruses cause a range of acute febrile illnesses along with encephalitic or haemorrhagic diseases. chronic hepatitis c virus (hcv) infection is the most important hepacivirus human disease and remains a global health threat with nearly 200 million carriers worldwide. current treatment consists in the use of pegin ... | 2009 | 19275702 |
| scientific consultation on cell mediated immunity (cmi) in dengue and dengue vaccine development. | dengue is a re-emerging arboviral disease of great public health importance. limited understanding of protective immune responses against dengue has hampered advancement of dengue vaccine candidates. demonstrating an immunological correlate of protection has been limited to associating quantitative neutralizing antibody titers with clinical outcomes following infection. there have been a number of studies investigating the role of cell mediated immunity (cmi) in natural infections and these have ... | 2009 | 19022321 |
| a single-amino acid substitution in west nile virus 2k peptide between ns4a and ns4b confers resistance to lycorine, a flavivirus inhibitor. | lycorine potently inhibits flaviviruses in cell culture. at 1.2-microm concentration, lycorine reduced viral titers of west nile (wnv), dengue, and yellow fever viruses by 10(2)- to 10(4)-fold. however, the compound did not inhibit an alphavirus (western equine encephalitis virus) or a rhabdovirus (vesicular stomatitis virus), indicating a selective antiviral spectrum. the compound exerts its antiviral activity mainly through suppression of viral rna replication. a val-->met substitution at the ... | 2009 | 19062063 |
| a small-molecule dengue virus entry inhibitor. | the incidence of dengue fever epidemics has increased dramatically over the last few decades. however, no vaccine or antiviral therapies are available. therefore, the need for safe and effective antiviral drugs has become imperative. the entry of dengue virus into a host cell is mediated by its major envelope (e) protein. the crystal structure of the e protein reveals a hydrophobic pocket that is presumably important for low-ph-mediated membrane fusion. high-throughput docking with this hydropho ... | 2009 | 19223625 |
| novel imino sugar derivatives demonstrate potent antiviral activity against flaviviruses. | imino sugars, such as n-butyl-deoxynojirimycin and n-nonyl-deoxynojirimycin (nndnj), are glucose analogues that selectively inhibit cellular alpha-glucosidase i and ii in the endoplasmic reticulum and exhibit antiviral activities against many types of enveloped viruses. although these molecules have broad-spectrum antiviral activity, their development has been limited by a lack of efficacy and/or selectivity. we have previously reported that a dnj derivative with a hydroxylated cyclohexyl side c ... | 2009 | 19223639 |
| the hidden passenger of lucky bamboo: do imported aedes albopictus mosquitoes cause dengue virus transmission in the netherlands? | since 2005, aedes albopictus mosquitoes have been detected in companies in the netherlands that import ornamental plants from china. to assess the risks of dengue transmission, a study was carried out in 48 persons who are professionally exposed to these mosquitoes. no evidence for non-travel-related flavivirus infections was found. | 2009 | 18959501 |
| gbv-c viremia is associated with reduced cd4 expansion in hiv-infected people receiving haart and interleukin-2 therapy. | interleukin-2 (il-2) is a cytokine with multiple effects on lymphocytes including induction of cd4 t-cell proliferation. il-2 administration has been shown to increase cd4 cell counts in hiv-infected people receiving antiretroviral therapy. gb virus c (gbv-c) is an apparently nonpathogenic flavivirus that replicates in cd4 t cells and inhibits hiv replication in vitro by mechanisms including downregulation of hiv entry coreceptors (ccr5 and cxcr4) and induction of chemokines (rantes, mip-1alpha, ... | 2009 | 19194270 |
| ticks associated with macquarie island penguins carry arboviruses from four genera. | macquarie island, a small subantarctic island, is home to rockhopper, royal and king penguins, which are often infested with the globally distributed seabird tick, ixodes uriae. a flavivirus, an orbivirus, a phlebovirus, and a nairovirus were isolated from these ticks and partial sequences obtained. the flavivirus was nearly identical to gadgets gully virus, isolated some 30 year previously, illustrating the remarkable genetic stability of this virus. the nearest relative to the orbivirus (for w ... | 2009 | 19194498 |
| a conserved predicted pseudoknot in the ns2a-encoding sequence of west nile and japanese encephalitis flaviviruses suggests ns1' may derive from ribosomal frameshifting. | japanese encephalitis, west nile, usutu and murray valley encephalitis viruses form a tight subgroup within the larger flavivirus genus. these viruses utilize a single-polyprotein expression strategy, resulting in ~10 mature proteins. plotting the conservation at synonymous sites along the polyprotein coding sequence reveals strong conservation peaks at the very 5' end of the coding sequence, and also at the 5' end of the sequence encoding the ns2a protein. such peaks are generally indicative of ... | 2009 | 19196463 |
| identification of the nonstructural protein 4b of hepatitis c virus as a factor that inhibits the antiviral activity of interferon-alpha. | interferon-alpha (ifn-alpha) is the most commonly used therapeutics for the treatment of chronic viral infection. however, many viruses are resistant to ifn-alpha treatment to some degrees through encoding inhibitors of the ifn-alpha producing or signaling pathway. multiple hcv viral proteins have been reported to be involved in ifn-alpha resistance. to develop a method to screen for factors that inhibit the antiviral activity of ifn-alpha, a mini-library of hcv genome was transduced into the hu ... | 2009 | 19185598 |
| evaluation of interferences between dengue vaccine serotypes in a monkey model. | interferences between different antigens in the same vaccine formulation have been reported for some vaccines (e.g., polio vaccines, live attenuated dengue vaccine candidates). we examined interferences between the four serotypes of chimerivax dengue vaccines (cyds) in a monkey model when present within a tetravalent formulation in equal concentrations (tv-5555). immunoassays of vaccinated non-human primates showed that serotype 4 (den-4), and to a lesser extent, den-1 were dominant in terms of ... | 2009 | 19190230 |
| a heterocyclic molecule with significant activity against dengue virus. | there are no specific approved drugs or vaccines for the treatment or prevention of infectious dengue virus and there are very few compounds known that inhibit the replication of this virus. this letter describes the concise synthesis of two uracil-based multifunctional compounds. one of these compounds (1) has strong activity against dengue virus. it also exhibits low activity against a few other rna viruses, but is highly active against yellow fever virus, a related flavivirus. it is likely th ... | 2009 | 19185487 |
| molecular targets for flavivirus drug discovery. | flaviviruses are a major cause of infectious disease in humans. dengue virus causes an estimated 50 million cases of febrile illness each year, including an increasing number of cases of hemorrhagic fever. west nile virus, which recently spread from the mediterranean basin to the western hemisphere, now causes thousands of sporadic cases of encephalitis annually. despite the existence of licensed vaccines, yellow fever, japanese encephalitis and tick-borne encephalitis also claim many thousands ... | 2009 | 18796313 |
| analysis of the nucleoside triphosphatase, rna triphosphatase, and unwinding activities of the helicase domain of dengue virus ns3 protein. | the helicase domain of dengue virus ns3 protein (denv ns3h) contains rna-stimulated nucleoside triphosphatase (ntpase), atpase/helicase, and rna 5'-triphosphatase (rtpase) activities that are essential for viral rna replication and capping. here, we show that denv ns3h unwinds 3'-tailed duplex with an rna but not a dna loading strand, and the helicase activity is poorly processive. the substrate of the divalent cation-dependent rtpase activity is not restricted to viral rna 5'-terminus, a protru ... | 2009 | 19166847 |
| spatial spreading of west nile virus described by traveling waves. | in this work, we propose a spatial model to analyze the west nile virus propagation across the usa, from east to west. west nile virus is an arthropod-borne flavivirus that appeared for the first time in new york city in the summer of 1999 and then spread prolifically among birds. mammals, such as humans and horses, do not develop sufficiently high bloodstream titers to play a significant role in the transmission, which is the reason to consider the mosquito-bird cycle. the model aims to study t ... | 2009 | 19167405 |
| glyceraldehyde-3-phosphate dehydrogenase (gapdh) interaction with 3' ends of japanese encephalitis virus rna and colocalization with the viral ns5 protein. | replication of the japanese encephalitis virus (jev) genome depends on host factors for successfully completing their life cycles; to do this, host factors have been recruited and/or relocated to the site of viral replication. glyceraldehyde-3-phosphate dehydrogenase (gapdh), a cellular metabolic protein, was found to colocalize with viral rna-dependent rna polymerase (ns5) in jev-infected cells. subcellular fractionation further indicated that gapdh remained relatively constant in the cytosol, ... | 2009 | 19368702 |
| pathogenesis of flavivirus infections: using and abusing the host cell. | flaviviruses, such as the dengue virus and the west nile virus, are emerging arthropod-borne viruses that represent an immense global health problem. considerable progress has been made in understanding flavivirus structure and replication strategies, but only now are the complex molecular interactions between the virus and host cell starting to be unraveled. in this review, we discuss the ongoing efforts toward elucidating the molecular mechanisms that allow flaviviruses to manipulate host cell ... | 2009 | 19380111 |
| rna interference inhibits yellow fever virus replication in vitro and in vivo. | rna interference (rnai) is a process that is induced by double stranded rna and involves the degradation of specific sequences of mrna in the cytoplasm of the eukaryotic cells. it has been used as an antiviral tool against many viruses, including flaviviruses. the genus flavivirus contains the most important arboviruses in the world, i.e., dengue (denv) and yellow fever (yfv). in our study, we investigated the in vitro and in vivo effect of rnai against yfv. using stable cell lines that expresse ... | 2009 | 19169857 |
| in vitro activity and preclinical profile of tmc435350, a potent hepatitis c virus protease inhibitor. | the hepatitis c virus (hcv) ns3/4a serine protease has been explored as a target for the inhibition of viral replication in preclinical models and in hcv-infected patients. tmc435350 is a highly specific and potent inhibitor of ns3/4a protease selected from a series of novel macrocyclic inhibitors. in biochemical assays using ns3/4a proteases of genotypes 1a and 1b, inhibition constants of 0.5 and 0.4 nm, respectively, were determined. tmc435350 inhibited hcv replication in a cellular assay (sub ... | 2009 | 19171797 |
| analysis of flavivirus ns5 methyltransferase cap binding. | the flavivirus 2'-o-nucleoside n-terminal rna methyltransferase (mtase) enzyme is responsible for methylating the viral rna cap structure. to increase our understanding of the mechanism of viral rna cap binding we performed a detailed structural and biochemical characterization of the guanosine cap-binding pocket of the dengue (den) and yellow fever (yf) virus mtase enzymes. we solved an improved 2.1 a resolution crystal structure of den2 mtase, new 1.5 a resolution crystal structures of the yf ... | 2009 | 19101564 |
| japanese encephalitis vaccine (inactivated, adsorbed) [ixiaro]. | the japanese encephalitis vaccine ic-51 (ixiaro) is an inactivated virus (strain sa(14)-14-2) that is manufactured in cultured vero cells and is currently being developed for preventive vaccination against the japanese encephalitis virus. black triangle administration of ixiaro as a two-dose treatment in healthy adults provided high levels of seroprotection against japanese encephalitis virus. immune responses at 56 days post-vaccination, including seroconversion rates and geometric mean titres, ... | 2009 | 19192940 |
| effect of sequential exposure on infection and dissemination rates for west nile and st. louis encephalitis viruses in culex quinquefasciatus. | west nile virus has spread rapidly throughout the united states since its introduction in 1999, into some areas that are also endemic for st. louis encephalitis virus (slev). these viruses are in the same antigenic complex within the genus flavivirus, family flaviviridae. further, both viruses are transmitted primarily by culex spp. mosquitoes and use birds as amplifying hosts. these viruses could contemporaneously coinfect individual vectors wherein changes in mosquito immune responses might oc ... | 2009 | 19492941 |
| characterization of culex flavivirus (flaviviridae) strains isolated from mosquitoes in the united states and trinidad. | recent reports indicate that flaviviruses similar to the cell fusing agent virus (cfav) naturally infect a wide variety of mosquito species. these newly recognized insect-specific viruses comprise a distinct cfav complex within the genus flavivirus. here, we describe the isolation and characterization of nine strains of culex flavivirus (cx fv), a member of the cfav complex, from mosquitoes collected in the united states (east texas) and trinidad. phylogenetic analyses of the envelope protein ge ... | 2009 | 19193389 |
| longitudinal studies of japanese encephalitis virus infection in vector mosquitoes in kurnool district, andhra pradesh, south india. | a 4-yr (2002-2006) entomological study was carried out in kurnool district, andhra pradesh state, south india, to identify the mosquito vectors of japanese encephalitis virus (family flaviviridae, genus flavivirus, jev). in total, 37,139 female mosquitoes belonging five genera and 18 species resting on vegetation were collected in villages and periurban areas at dusk. mosquito species composition and pattern of jev infection in mosquitoes varied in periurban and rural areas. in periurban area, c ... | 2009 | 19496437 |
| surveillance of mosquito-borne viruses in alberta using reverse transcription polymerase chain reaction with generic primers. | mosquitoes collected during 2003, 2004, and 2005 in alberta, canada, were screened for the presence of a wide range of arboviruses by reverse transcription-polymerase chain reaction (rt-pcr). nucleic acid extracts from mosquito slurries were amplified using universal primers designed to detect viruses belonging to the flavivirus genus of the flaviviridae family and california and bunyamwera serogroups of the bunyavirus genus within the bunyaviridae family. species-specific detection of western e ... | 2009 | 19496438 |
| crm1-mediated nuclear export of dengue virus rna polymerase ns5 modulates interleukin-8 induction and virus production. | although all established functions of dengue virus ns5 (nonstructural protein 5) occur in the cytoplasm, its nuclear localization, mediated by dual nuclear localization sequences, is essential for virus replication. here, we have determined the mechanism by which ns5 can localize in the cytoplasm to perform its role in replication, establishing for the first time that it is able to be exported from the nucleus by the exportin crm1 and hence can shuttle between the nucleus and cytoplasm. we defin ... | 2009 | 19297323 |
| flaviviral methyltransferase/rna interaction: structural basis for enzyme inhibition. | flaviviruses are the causative agents of severe diseases such as dengue or yellow fever. the replicative machinery used by the virus is based on few enzymes including a methyltransferase, located in the n-terminal domain of the ns5 protein. flaviviral methyltransferases are involved in the last two steps of the mrna capping process, transferring a methyl group from s-adenosyl-l-methionine onto the n7 position of the cap guanine (guanine-n7 methyltransferase) and the ribose 2'o position of the fi ... | 2009 | 19501254 |
| sequence signatures in envelope protein may determine whether flaviviruses produce hemorrhagic or encephalitic syndromes. | we analyzed the envelope proteins in pathogenic flaviviruses to determine whether there are sequence signatures associated with the tendency of viruses to produce hemorrhagic disease (h-viruses) or encephalitis (e-viruses). we found that, at the position corresponding to the glycosylated asn-67 in dengue virus, asparagine (asn) occurs in all seven viral species that cause hemorrhagic disease in humans. furthermore, asn was extremely rare at position 67 in six flaviviruses that cause encephalitis ... | 2009 | 19283462 |
| modeling gene sequence changes over time in type 3 dengue viruses from ecuador. | dengue virus (denv) is a member of the genus flavivirus of the family flaviviridae. denv-3 re-emerged in central america in 1994, and continues to expand into the south american region. little is known about the evolutionary rates, viral spread and population dynamics of this genotype in the latin american region. in order to gain insight into these matters, we used a bayesian markov chain monte carlo (mcmc) approach, to analyze envelope (e) gene sequences of the denv-3 genotype iii of strains i ... | 2009 | 19185597 |
| flavivirus ns5 associates with host-cell proteins zonula occludens-1 (zo-1) and regulating synaptic membrane exocytosis-2 (rims2) via an internal pdz binding mechanism. | dengue virus (denv) and tick-borne encephalitis virus (tbev) are flaviviruses, which can cause lethal hemorrhagic fever and encephalitis, respectively. here, we demonstrate that the tbev-ns5 and denv-ns5 proteins use an internal binding mechanism to target human pdz proteins. tbev-ns5 has high affinity to regulating synaptic membrane exocytosis-2 (rims2) and scribble, whereas denv-ns5 binds primarily to the tight junction protein zonula occludens-1 (zo-1). targeting of tbev-ns5 to the plasma mem ... | 2009 | 19199833 |
| identification of cellular proteome modifications in response to west nile virus infection. | flaviviruses are positive-stranded rna viruses that are a public health problem because of their widespread distribution and their ability to cause a variety of diseases in humans. west nile virus is a mosquito-borne member of this genus and is the etiologic agent of west nile encephalitis. clinical manifestations of west nile virus infection are diverse, and their pathogenic mechanisms depend on complex virus-cell interactions. in the present work, we used proteomics technology to analyze early ... | 2009 | 19395707 |
| conservation and variability of west nile virus proteins. | west nile virus (wnv) has emerged globally as an increasingly important pathogen for humans and domestic animals. studies of the evolutionary diversity of the virus over its known history will help to elucidate conserved sites, and characterize their correspondence to other pathogens and their relevance to the immune system. we describe a large-scale analysis of the entire wnv proteome, aimed at identifying and characterizing evolutionarily conserved amino acid sequences. this study, which used ... | 2009 | 19401763 |
| toll-like receptor 7 mitigates lethal west nile encephalitis via interleukin 23-dependent immune cell infiltration and homing. | west nile virus (wnv), a mosquito-transmitted single-stranded rna (ssrna) flavivirus, causes human disease of variable severity. we investigated toll-like receptor 7-deficient (tlr7(-/-)) and myeloid differentiation factor 88-deficient (myd88(-/-)) mice, which both have defective recognition of ssrna, and found increased viremia and susceptibility to lethal wnv infection. despite increased tissue concentrations of most innate cytokines, cd45(+) leukocytes and cd11b(+) macrophages failed to home ... | 2009 | 19200759 |
| nucleotide sequences and modifications that determine rig-i/rna binding and signaling activities. | cytoplasmic viral rnas with 5' triphosphates (5'ppp) are detected by the rna helicase rig-i, initiating downstream signaling and alpha/beta interferon (ifn-alpha/beta) expression that establish an antiviral state. we demonstrate here that the hepatitis c virus (hcv) 3' untranslated region (utr) rna has greater activity as an immune stimulator than several flavivirus utr rnas. we confirmed that the hcv 3'-utr poly(u/uc) region is the determinant for robust activation of rig-i-mediated innate immu ... | 2009 | 19224987 |
| induction of specific and flavivirus--cross-reactive ctls by immunization with a single dengue virus-derived ctl epitope peptide. | specificities of cytotoxic t lymphocyte (ctl) effector cells induced in balb/c mouse by immunization with the single modified ctl epitope peptide derived from ns3 of dengue virus types 1 and 3, or that of dengue virus types 2 and 4 were examined. the effector cells included ctls specific for the epitope peptide used for immunization and those cross-reactive to epitope peptides of other flaviviruses. a ctl clone, 2f7, was established from the effector cells. the clone 2f7 was specific for the epi ... | 2009 | 19427342 |
| a pyrazolotriazolopyrimidinamine inhibitor of bovine viral diarrhea virus replication that targets the viral rna-dependent rna polymerase. | [7-[3-(1,3-benzodioxol-5-yl)propyl]-2-(2-furyl)-7h-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine] (lz37) was identified as a selective inhibitor of in vitro bovine viral diarrhea virus (bvdv) replication. the ec(50) values for inhibition of bvdv-induced cytopathic effect (cpe) formation, viral rna synthesis and production of infectious virus were 4.3+/-0.7microm, 12.9+/-1microm and 5.8+/-0.6microm, respectively. lz37 proved inactive against the hepatitis c virus and the flavivirus yello ... | 2009 | 19428605 |
| fatal case of deer tick virus encephalitis. | deer tick virus is related to powassan virus, a tickborne encephalitis virus. a 62-year-old man presented with a meningoencephalitis syndrome and eventually died. analyses of tissue samples obtained during surgery and at autopsy revealed a widespread necrotizing meningoencephalitis. nucleic acid was extracted from formalin-fixed tissue, and the presence of deer tick virus was verified on a flavivirus-specific polymerase-chain-reaction (pcr) assay, followed by sequence confirmation. immunohistoch ... | 2009 | 19439744 |
| a new flavivirus and a new vector: characterization of a novel flavivirus isolated from uranotaenia mosquitoes from a tropical rain forest. | a novel flavivirus was isolated from uranotaenia mashonaensis, a mosquito genus not previously known to harbor flaviviruses. mosquitoes were caught in the primary rain forest of the taï national park, côte d'ivoire. the novel virus, termed nounané virus (nouv), seemed to grow only on c6/36 insect cells and not on vertebrate cells. typical enveloped flavivirus-like particles of 60 to 65 nm in diameter were detected by electron microscopy in the cell culture supernatant of infected cells. the full ... | 2009 | 19224998 |
| cyclosporine inhibits flavivirus replication through blocking the interaction between host cyclophilins and viral ns5 protein. | although flaviviruses cause significant human diseases, no effective therapy is currently available. host factors essential for viral replication are potential targets for antiviral development. here we report that cyclophilins (cyps), a family of cellular peptidyl-prolyl isomerases (ppiases), play a role in flavivirus replication. huh-7.5 cells with knockdown of different isoforms of cyp were less efficient than parental cells in supporting flavivirus replication, including west nile virus (wnv ... | 2009 | 19451286 |
| [population interactions of west nile virus (flaviviridae, flavivirus) with arthropode vectors, vertebrates, humans in the middle and low belts of volga delta in 2001-2006]. | the population interactions of west nile virus in the middle and lower regions of the volga delta in 2001-2006 were studied. the authors established major species of the mosquitoes anopheles messeae, an. hyrcanus, culex piplens, cx modestus, coquilletidia richiardii in anthropogenic biocenoses and an. hyrcanus, coq. richiardii in the natural ones; vertebrates - crows (corvidae) and domestic animals in the anthropogenic biocenoses and cormorants in the natural ones. the ticks hyalomma marginatum ... | 2009 | 19459411 |
| molecular evolution of dengue viruses: contributions of phylogenetics to understanding the history and epidemiology of the preeminent arboviral disease. | dengue viruses (denv) are the most important arboviral pathogens in tropical and subtropical regions throughout the world, putting at risk of infection nearly a third of the global human population. evidence from the historical record suggests a long association between these viruses and humans. the transmission of denv includes a sylvatic, enzootic cycle between nonhuman primates and arboreal mosquitoes of the genus aedes, and an urban, endemic/epidemic cycle between aedes aegypti, a mosquito w ... | 2009 | 19460319 |
| japanese encephalitis virus ns2b-ns3 protease induces caspase 3 activation and mitochondria-mediated apoptosis in human medulloblastoma cells. | japanese encephalitis virus (jev) causes severe neurological diseases with a high fatality rate. clinical, neurophysiological and radiological features of japanese encephalitis je patients showed that jev infection resulted in widespread involvement of the nervous system, including thalamus, basal ganglia, brainstem, cerebellum, cerebral cortex and spinal cord. in this study, we characterized the apoptotic effect of jev infection and its viral proteins on the te671 human medulloblastoma cells. j ... | 2009 | 19463724 |
| atomic structure reveals the unique capsid organization of a dsrna virus. | for most dsrna viruses, the genome-enclosing capsid comprises 120 copies of a single capsid protein (cp) organized into 60 icosahedrally equivalent dimers, generally identified as 2 nonsymmetricallyinteracting cp molecules with extensive lateral contacts. the crystal structure of a partitivirus, penicillium stoloniferum virus f (psv-f), reveals a different organization, in which the cp dimer is related by almost-perfect local 2-fold symmetry, forms prominent surface arches, and includes extensiv ... | 2009 | 19246376 |
| clinical evaluation of highly pathogenic tick-borne flavivirus infection in the mouse model. | the objective of this study was to evaluate the feasibility of using clinical parameters to demonstrate disease progression and differentiate between omsk hemorrhagic fever virus (ohfv) and russian spring-summer encephalitis virus (rssev) infection in the mouse model. adult c57bl/6 and balb/c mice were infected with either ohfv or rssev by footpad inoculation and their temperature, body weight, clinical signs complete blood count, and blood chemistries were evaluated for up to 15 days post-infec ... | 2009 | 19475605 |
| metal ion-binding studies highlight important differences between flaviviral rna polymerases. | west nile virus (wnv) is a member of the flaviviridae family which includes a number of important human pathogens. the wnv ns5 protein harbors an rna-dependent rna polymerase activity which is required both for replication and transcription of the viral genome. to extend our studies on the role of metal ions in the activity of flaviviral polymerases, we have used fluorescence spectroscopy, circular dichroism, and a combination of chemical and thermal denaturation assays to monitor the consequenc ... | 2009 | 18930844 |
| tick-borne flaviviruses: dissecting host immune responses and virus countermeasures. | the tick-borne encephalitis (tbe) serocomplex of viruses, genus flavivirus, includes a number of important human pathogens that cause serious neurological illnesses and hemorrhagic fevers. these viruses pose a significant public health problem due to high rates of morbidity and mortality, their emergence to new geographic areas, and the recent rise in the incidence of human infections. the most notable member of the tbe serocomplex is tick-borne encephalitis virus (tbev), a neurotropic flaviviru ... | 2009 | 18841330 |
| synthesis of the first example of a nucleoside analogue bearing a 5'-deoxy-beta-d-allo-septanose as a seven-membered ring sugar moiety. | the first example of a nucleoside analogue bearing a 5'-deoxy-beta-d-allo-septanose as a seven-membered ring sugar moiety, namely 9-(5-deoxy-beta-d-allo-septanosyl)-adenine, is reported. this compound was synthesized in 14 steps from the commercially available d-glycero-d-gulo-1,4-lactone. when evaluated in cell culture experiments against a broad range of viruses, it did not exhibit any significant antiviral effect or cytotoxicity. | 2009 | 19147123 |
| development of real time pcr for detection and quantitation of dengue viruses. | dengue virus (denv), a mosquito borne flavivirus is an important pathogen causing more than 50 million infections every year around the world. dengue diagnosis depends on serology, which is not useful in the early phase of the disease and virus isolation, which is laborious and time consuming. there is need for a rapid, sensitive and high throughput method for detection of denv in the early stages of the disease. several real-time pcr assays have been described for dengue viruses, but there is s ... | 2009 | 19166574 |
| detection of rna from a novel west nile-like virus and high prevalence of an insect-specific flavivirus in mosquitoes in the yucatan peninsula of mexico. | as part of our ongoing surveillance efforts for west nile virus (wnv) in the yucatan peninsula of mexico, 96,687 mosquitoes collected from january through december 2007 were assayed by virus isolation in mammalian cells. three mosquito pools caused cytopathic effect. two isolates were orthobunyaviruses (cache valley virus and kairi virus) and the identity of the third infectious agent was not determined. a subset of mosquitoes was also tested by reverse transcription-polymerase chain reaction (r ... | 2009 | 19141845 |
| recognition of rna cap in the wesselsbron virus ns5 methyltransferase domain: implications for rna-capping mechanisms in flavivirus. | the mrna-capping process starts with the conversion of a 5'-triphosphate end into a 5'-diphosphate by an rna triphosphatase, followed by the addition of a guanosine monophosphate unit in a 5'-5' phosphodiester bond by a guanylyltransferase. methyltransferases are involved in the third step of the process, transferring a methyl group from s-adenosyl-l-methionine to n7-guanine (cap 0) and to the ribose 2'oh group (cap 1) of the first rna nucleotide; capping is essential for mrna stability and prop ... | 2009 | 18976670 |
| structural and functional studies of the promoter element for dengue virus rna replication. | the 5' untranslated region (5'utr) of the dengue virus (denv) genome contains two defined elements essential for viral replication. at the 5' end, a large stem-loop (sla) structure functions as the promoter for viral polymerase activity. next to the sla, there is a short stem-loop that contains a cyclization sequence known as the 5' upstream aug region (5'uar). here, we analyzed the secondary structure of the sla in solution and the structural requirements of this element for viral replication. ... | 2009 | 19004935 |
| ecology and geographical expansion of japanese encephalitis virus. | japanese encephalitis virus (jev) (flavivirus: flaviviridae) is a leading cause of encephalitis in eastern and southern asia. the virus is maintained in a zoonotic cycle between ardeid wading birds and/or pigs and culex mosquitoes. the primary mosquito vector of jev is culex tritaeniorhynchus, although species such as cx. gelidus, cx. fuscocephala, and cx. annulirostris are important secondary or regional vectors. control of jev is achieved through human and/or swine vaccination, changes in anim ... | 2009 | 19067628 |
| the hepatitis c virus ns4b protein can trans-complement viral rna replication and modulates production of infectious virus. | studies of the hepatitis c virus (hcv) life cycle have been aided by development of in vitro systems that enable replication of viral rna and production of infectious virus. however, the functions of the individual proteins, especially those engaged in rna replication, remain poorly understood. it is considered that ns4b, one of the replicase components, creates sites for genome synthesis, which appear as punctate foci at the endoplasmic reticulum (er) membrane. in this study, a panel of mutatio ... | 2009 | 19073716 |
| construction and characterization of a single-cycle chimeric flavivirus vaccine candidate that protects mice against lethal challenge with dengue virus type 2. | we have previously described a novel flavivirus vaccine technology based on a single-cycle, capsid (c) gene-deleted flavivirus called replivax. replivax can be propagated in cells that express high levels of c but undergoes only a single cycle of infection in vaccinated hosts. here we report that we have adapted our replivax technology to produce a dengue vaccine by replacing the prm/e genes of replivax wn (a west nile virus [wnv] replivax) with the same genes of dengue virus type 2 (denv2). our ... | 2009 | 19073745 |
| structure of west nile virus ns3 protease: ligand stabilization of the catalytic conformation. | over the last decade, west nile virus has spread rapidly via mosquito transmission from infected migratory birds to humans. one potential therapeutic approach to treating infection is to inhibit the virally encoded serine protease that is essential for viral replication. here we report the crystal structure of the viral ns3 protease tethered to its essential ns2b cofactor and bound to a potent substrate-based tripeptide inhibitor, 2-naphthoyl-lys-lys-arg-h (k(i)=41 nm), capped at the n-terminus ... | 2009 | 19059417 |
| serological survey of domestic animals for tick-borne encephalitis and bhanja viruses in northeastern hungary. | blood sera collected from 400 domestic animals (260 cattle, 100 merino sheep, and 40 hutzul horses) in northeastern hungary in 2005 were examined for antibodies against two tick-borne viruses, tick-borne encephalitis flavivirus (tbev) and bhanja bunyavirus (bhav). using elisa as screening test and plaque-reduction neutralization as confirmatory test, seropositivity to tbev was found to be 26.5% in cattle, 7.0% in sheep, and 0.0% in horses. among cattle, the animals up to 3 years old had signific ... | 2009 | 19036537 |
| divergent picornavirus ires elements. | internal ribosome entry site (ires) elements were first identified about 20 years ago within the 5' untranslated region of picornavirus rnas. they direct a cap-independent mechanism of translation initiation on the viral rna. within the picornavirus family it is now known that there are four classes of ires element which vary in size (450-270 nt), they also have different, complex, secondary structures and distinct requirements for cellular proteins to allow them to function. this review describ ... | 2009 | 18675861 |
| detection and monitoring of mosquito flaviviruses in spain between 2001 and 2005. | between the years 2001 and 2005, a total of 72,895 female mosquitoes were trapped during their season of abundance, and analyzed. they were sorted into 4,723 pools belonging to 20 culicidae species from the anopheles, aedes, ochlerotatus, culex, culiseta, coquillettidia, and uranotaenia genera. the aim was to detect arboviral rna directly from mosquito homogenates for the genera alphavirus, flavivirus, and phlebovirus. the study formed part of general arbovirus transmission research in four of t ... | 2009 | 18959502 |
| mechanism of ns2b-mediated activation of ns3pro in dengue virus: molecular dynamics simulations and bioassays. | the ns2b cofactor is critical for proteolytic activation of the flavivirus ns3 protease. to elucidate the mechanism involved in ns2b-mediated activation of ns3 protease, molecular dynamic simulation, principal component analysis, molecular docking, mutagenesis, and bioassay studies were carried out on both the dengue virus ns3pro and ns2b-ns3pro systems. the results revealed that the ns2b-ns3pro complex is more rigid than ns3pro alone due to its robust hydrogen bond and hydrophobic interaction n ... | 2009 | 18971276 |
| genome cyclization as strategy for flavivirus rna replication. | long-range and local rna-rna contacts in viral rna genomes result in tertiary structures that modulate the function of enhancers, promoters, and silencers during translation, rna replication, and encapsidation. in the case of flaviviruses, the presence of inverted complementary sequences at the 5' and 3' ends of the genome mediate long-range rna interactions and rna cyclization. the circular conformation of flavivirus genomes was demonstrated to be essential for rna amplification. new ideas abou ... | 2009 | 18703097 |
| simulation of climate-change scenarios to explain usutu-virus dynamics in austria. | the emergence and spread of infectious diseases in mid-latitudes, so far mainly observed in the tropics, considerably increase under the current situation of climate change. a recent example is the usutu virus (usuv) outbreak in austria. usuv is closely related to the west nile virus in the u.s. and caused mass mortalities mainly of blackbirds (turdus merula). the usuv flavivirus persists in a natural transmission cycle between vectors (mosquitoes) and host reservoirs (birds) and leads - once en ... | 2009 | 18715663 |
| protein kinase g phosphorylates mosquito-borne flavivirus ns5. | serine/threonine phosphorylation of the nonstructural protein 5 (ns5) is a conserved feature of flaviviruses, but the kinase(s) responsible and function(s) remain unknown. mass spectrometry was used to compare the phosphorylation sites of the ns5 proteins of yellow fever virus (yfv) and dengue virus (denv), two flaviviruses transmitted by mosquitoes. seven denv phosphopeptides were identified, but only one conserved phosphoacceptor site (threonine 449 in denv) was identified in both viruses. thi ... | 2009 | 19587048 |
| selective involvement of temporal regions in a case of flavivirus encephalitis. | clinical manifestations of flavivirus infection may be various, from unapparent to severe meningoencephalitis. our patient, 2 weeks after returning home from a holiday at elba island, developed biphasic fever, later associated with nausea and vomiting and followed by incoming seizures responsive to thiopental sodium only. brain mri showed bilateral hyperintensity (t2) in amygdale, hippocampus, left insular and temporal inferior cortex. standard and microbiological csf examination was normal, but ... | 2009 | 19590822 |
| the risk of dengue transmission by blood during a 2004 outbreak in cairns, australia. | dengue virus (denv) is a flavivirus transmitted by the aedes mosquito. the related arbovirus, west nile virus, has been shown to be transfusion transmitted, which, added to the four recorded dengue transfusion-associated cases, indicates that denv is also transfusion transmitted. the purpose of this study was to assess the risk of transfusion-transmitted denv during a 2004 outbreak in the australian city of cairns. | 2009 | 19389025 |
| changing patterns of west nile virus transmission: altered vector competence and host susceptibility. | west nile virus (wnv) is a flavivirus (flaviviridae) transmitted between culex spp. mosquitoes and avian hosts. the virus has dramatically expanded its geographic range in the past ten years. increases in global commerce, climate change, ecological factors and the emergence of novel viral genotypes likely play significant roles in the emergence of this virus; however, the exact mechanism and relative importance of each is uncertain. previously wnv was primarily associated with febrile illness of ... | 2009 | 19406093 |
| virus-host coevolution: common patterns of nucleotide motif usage in flaviviridae and their hosts. | virus-host biological interaction is a continuous coevolutionary process involving both host immune system and viral escape mechanisms. flaviviridae family is composed of fast evolving rna viruses that infects vertebrate (mammals and birds) and/or invertebrate (ticks and mosquitoes) organisms. these host groups are very distinct life forms separated by a long evolutionary time, so lineage-specific anti-viral mechanisms are likely to have evolved. flaviviridae viruses which infect a single host l ... | 2009 | 19617912 |
| [dengue fever: from disease to vaccination]. | dengue is a tropical disease affecting 110 countries throughout the world and placing over 3 billion people at risk of infection. according the world health organization 70 to 500 million persons are infected every year including 2 million who develop hemorrhagic form and 20,000 who die. children are at highest risk for death. due to the absence of specialized laboratories in most endemic regions and to the lack of specifici clinical presentation, the incidence of dengue and its economic costs a ... | 2009 | 19725380 |
| [dengue and other arboviral diseases in south-east asia]. | the most medically significant arboviruses causing human illness in south-east asia belong to the genera flavivirus (dengue, japanese encephalitis, kunjin, zika, etc.) and alphavirus (chikungunya, sindbis, getah, etc.). all of these arboviral diseases are transmitted by mosquitoes. dengue virus is the most prevalent arbovirus in south-east asia and constitutes a major public health problem. japanese encephalitis virus is also widespread in the region and symptomatic infection is associated with ... | 2009 | 19725383 |
| coimmunization with an optimized il15 plasmid adjuvant enhances humoral immunity via stimulating b cells induced by genetically engineered dna vaccines expressing consensus jev and wnv e diii. | the japanese encephalitis virus (jev) and west nile virus (wnv) are responsible for a large proportion of viral encephalitis in humans. currently, there is no fda approved specific treatment for either, though there are attempts to develop vaccines against both viruses. in this study, we proposed novel genetically engineered dna vaccines against these two neurotrophic flaviviruses. the structural domain iii (diii) of e protein from these viruses is reported to carry dominant epitopes that induce ... | 2009 | 19497647 |
| hepatitis c virus ns4b induces unfolded protein response and endoplasmic reticulum overload response-dependent nf-kappab activation. | hepatitis c virus nonstructural protein 4b (ns4b) is an endoplasmic reticulum (er) membrane associated protein and a potent causative factor of er stress. here we reported that unfolded protein response (upr) can be activated by hcv ns4b through inducing both xbp1 mrna splicing and atf6 cleavage in human hepatic cells. flow cytometric analysis revealed that hcv ns4b stimulates the production of reactive oxygen species (ros) by perturbing intracellular ca(2+) homeostasis. luciferase assay showed ... | 2009 | 19628242 |
| longitudinal myelitis associated with yellow fever vaccination. | severe adverse reaction to yellow fever (yf) vaccine includes the yellow fever vaccine-associated neurotropic disease. this terminology includes postvaccinal encephalitis, acute disseminated encephalomyelitis, and guillain-barré syndrome. the objective of this communication is to report a patient who received a yf vaccine in argentina and subsequently developed longitudinal myelitis with a symptom that had previously gone unreported in the literature. a 56-year-old man began with progressive par ... | 2009 | 19579072 |
| antibodies to flaviviruses in wild ducks captured in hokkaido, japan: risk assessment of invasive flaviviruses. | recently, the distribution of japanese encephalitis virus (jev) and west nile virus (wnv) has expanded into new territories. the invasion of wnv into japan is of great concern. the migration of birds is suggested to be involved in the expanded distribution of these flaviviruses. in this study, 92 wild ducks--20 anas poecilorhyncha (migratory breeders), 50 anas platyrhynchos (undetermined), 16 anas acuta (winter visitors), and 6 anas penelope (winter visitors)--were captured in autumn of 2005 and ... | 2009 | 19514809 |
| isolation and characterization of a new insect flavivirus from aedes albopictus and aedes flavopictus mosquitoes in japan. | we isolated a new flavivirus from aedes albopictus mosquito and a related species in japan. the virus, designated aedes flavivirus (aefv), only replicated in a mosquito cell line and produced a mild cytopathic effect. the aefv genome was positive-sense, single-stranded rna, 11,064 nucleotides in length and contained a single open reading frame encoding a polyprotein of 3341 amino acids with 5' and 3' untranslated regions (utrs) of 96 and 945 nucleotides, respectively. genetic and phylogenetic an ... | 2009 | 19580982 |