Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| [development of amplification technology-based methods for tick-borne encephalitis virus detection and genotyping]. | the development of methods for tick-borne encephalitis (tbe) virus genotyping, such as determination of nucleotide sequences, analysis of restriction fragment length polymorphism, polymerase chain reaction using genotype-specific probes with hybridization-fluorescence detection, is under consideration. the capacities and application area of varions typing techniques, such as tbe detection and genotyping in the field, autoptic, and cultural materials; study of circulating genotypes in different n ... | 2007 | 18050712 |
| proliferative index in astrocytic tumours. | the accurate grading of astrocytic tumours is of prime importance because it is critical to the patient management and survival/outcome. although internationally accepted who grading system of cns tumours is based on histological features of h&e stained sections, yet there are cases where differentiation between grade ii and grade iii is difficult particularly when the biopsy is small. proliferative index derived from mib-1 immunostaining has been found to be useful in the distinction between va ... | 2007 | 18306542 |
| [west nile fever/encephalitis]. | west nile virus (wnv), a member of the family flaviviridae (genus flavivirus), is a mosquito-borne virus first isolated in 1937 in the west nile district of uganda. the disease in humans is characterized by a dengue-like illness with fever, and a more severe form is characterized by central nervous system involvement, including encephalitis, meningitis, and myelitis. wn encephalitis was first reported in the western hemisphere in the summer of 1999, there was an outbreak in new york city. epidem ... | 2007 | 18357758 |
| analysis of the domain interactions between the protease and helicase of ns3 in dengue and hepatitis c virus. | flaviviridae non-structural 3 protein (ns3) is a multifunctional enzyme, composed by a protease domain (ns3pro) and an rna helicase domain (ns3hel). the activities present in ns3 have proved to be critical for viral replication. the replicative cycle of flaviviridae requires coordinated regulation of all the activities present in the full-length ns3 protein, however, the exact nature of these interactions remains unclear. the present work aimed to determine common structural features between ns3 ... | 2007 | 16762573 |
| yellow fever: a disease that has yet to be conquered. | yellow fever virus (yfv) is the prototype member of the genus flavivirus, a group of viruses that are transmitted between vertebrates by arthropod vectors. the virus is found in tropical regions of africa and south america and is transmitted to primates by mosquitoes: aedes spp. in africa and haemagogus and sabethes spp. in south america. despite the availability of an effective vaccine, yellow fever (yf) is considered a reemerging disease owing to its increased incidence in the past 25 years. m ... | 2007 | 16913829 |
| cell-specific adaptation of two flaviviruses following serial passage in mosquito cell culture. | west nile virus (wnv) is a mosquito-borne flavivirus that was introduced into the u.s. in the new york city area in 1999. despite its successful establishment and rapid spread in a naive environment, wnv has undergone limited evolution since its introduction. this evolutionary stability has been attributed to compromises made to permit alternating cycles of viral replication in vertebrate hosts and arthropod vectors. outbreaks of a close relative of wnv, st. louis encephalitis virus (slev), occu ... | 2007 | 16963095 |
| preparation and immunogenic properties of a recombinant west nile subunit vaccine. | while several west nile vaccines are being developed, none are yet available for humans. in this study aimed at developing a vaccine for humans, west nile virus (wnv) envelope protein (e) and non-structural protein 1 (ns1) were produced in the drosophila s2 cell expression system. the c-terminal 20% of the e protein, which contains the membrane anchor portion, was deleted, thus allowing for efficient secretion of the truncated protein (80e) into the cell culture medium. the proteins were purifie ... | 2007 | 16996661 |
| structural analysis of viral nucleocapsids by subtraction of partial projections. | the nucleocapsid of flavivirus particles does not have a recognizable capsid structure when using icosahedral averaging for cryo-electron microscopy structure determinations. the apparent absence of a definitive capsid structure could be due to a lack of synchronization of the symmetry elements of the external glycoprotein layer with those of the core or because the nucleocapsid does not have the same structure within each particle. a technique has been developed to determine the structure of th ... | 2007 | 17064936 |
| cleavage preference distinguishes the two-component ns2b-ns3 serine proteinases of dengue and west nile viruses. | regulated proteolysis of the polyprotein precursor by the ns2b-ns3 protease is required for the propagation of infectious virions. unless the structural and functional parameters of ns2b-ns3 are precisely determined, an understanding of its functional role and the design of flaviviral inhibitors will be exceedingly difficult. our objectives were to define the substrate recognition pattern of the ns2b-ns3 protease of west nile and dengue virises (wnv and dv respectively). to accomplish our goals, ... | 2007 | 17067286 |
| direct repeats in the flavivirus 3' untranslated region; a strategy for survival in the environment? | previously, direct repeats (drs) of 20-70 nucleotides were identified in the 3' untranslated regions (3'utr) of flavivirus sequences. to address their functional significance, we have manually generated a pan-flavivirus 3'utr alignment and correlated it with the corresponding predicted rna secondary structures. this approach revealed that intra-group-conserved drs evolved from six long repeated sequences (lrss) which, as approximately 200-nucleotide domains were preserved only in the genomes of ... | 2007 | 17067651 |
| genetic characterization of a new insect flavivirus isolated from culex pipiens mosquito in japan. | we found a new flavivirus that is widespread in culex pipiens and other culex mosquitoes in japan. the virus isolate, named culex flavivirus (cxfv), multiplied only in mosquito cell lines producing a moderate cytopathic effect, but did not grow in mammalian cells. the cxfv genome is single-stranded rna, 10,834 nt in length and containing a single open reading frame encoding a polyprotein of 3362 aa with 5' and 3' untranslated regions (utrs) of 91 and 657 nt, respectively. phylogenetic analyses r ... | 2007 | 17070886 |
| gb virus b disrupts rig-i signaling by ns3/4a-mediated cleavage of the adaptor protein mavs. | understanding the mechanisms of hepatitis c virus (hcv) pathogenesis and persistence has been hampered by the lack of small, convenient animal models. gb virus b (gbv-b) is phylogenetically the closest related virus to hcv. it causes generally acute and occasionally chronic hepatitis in small primates and is used as a surrogate model for hcv. it is not known, however, whether gbv-b has evolved strategies to circumvent host innate defenses similar to those of hcv, a property that may contribute t ... | 2007 | 17093192 |
| a gis tool to estimate west nile virus risk based on a degree-day model. | west nile virus (flaviviridae: flavivirus) is a serious infectious disease that recently spread across the north america continent. a spatial analysis tool was developed on the arcmap 9.x platform to estimate potential west nile virus activity using a spatially explicit degree-day model. the model identifies when the virus extrinsic incubation period (eip) is completed within the vector longevity during mid-summer months. the eip is treated as a threshold indicator of the potential for virus eme ... | 2007 | 17106782 |
| development of multiplex real-time reverse transcriptase pcr assays for detecting eight medically important flaviviruses in mosquitoes. | a multiplex real-time reverse transcriptase pcr has been developed for the rapid detection and identification of eight medically important flaviviruses from laboratory-reared, virus-infected mosquito pools. the method used involves the gene-specific amplification of yellow fever virus (yfv), japanese encephalitis virus (jev), west nile virus (wnv), st. louis encephalitis virus (slev), and dengue virus (denv) serotypes 1 to 4 (denv-1 to denv-4, respectively) by use of the flavivirus consensus amp ... | 2007 | 17108075 |
| defective interfering rnas of japanese encephalitis virus found in mosquito cells and correlation with persistent infection. | defective interfering (di) rnas are deletion mutants of viral genomes that are known in many cases to contribute to persistent infection and modification of viral pathogenesis. cell type also plays a critical role in the establishment of viral persistence. in this study we have identified for the first time the generation of di rnas of japanese encephalitis virus in c6/36 mosquito cells. a persistent infection was established by replacing growth medium on surviving cells and continued cell passa ... | 2007 | 17134784 |
| enzymatic characterization of a trypsin-like serine protease encoded by the genome of cell fusing agent virus. | cell fusing agent virus (cfav) is a positive strand rna insect virus first isolated from a mosquito cell line. based on viral morphology, phenotypic and phylogenetic studies, cfav had been tentatively assigned to the genus flavivirus (family flaviviridae). the determination of the cfav polyprotein complete sequence showed a putative serine protease domain analogue to the flaviviral ns2b/ns3 complex. this complex had been extensively studied, because it represented one of the main targets for ant ... | 2007 | 17143721 |
| immunopathology of flavivirus infections. | with the recent emergence of the flavivirus, west nile virus (wnv), in particular, the new york strain of lineage i wnv in north america in 1999, there has been a significant increase in activity in neurotropic flavivirus research. these viruses cause encephalitis that can result in permanent neurological sequelae or death. attempts to develop vaccines have made progress, but have been variably successful, despite considerable commercial underwriting. thus, the discovery of ways and means to com ... | 2007 | 17146465 |
| antiviral peptides targeting the west nile virus envelope protein. | west nile virus (wnv) can cause fatal murine and human encephalitis. the viral envelope protein interacts with host cells. a murine brain cdna phage display library was therefore probed with wnv envelope protein, resulting in the identification of several adherent peptides. of these, peptide 1 prevented wnv infection in vitro with a 50% inhibition concentration of 67 mum and also inhibited infection of a related flavivirus, dengue virus. peptide 9, a derivative of peptide 1, was a particularly p ... | 2007 | 17151121 |
| mutation analysis of the fusion domain region of st. louis encephalitis virus envelope protein. | the immune response to flavivirus infections produces both species-specific and flavivirus cross-reactive antibodies. the presence of cross-reactive antibodies complicates serodiagnosis of flavivirus infections, especially secondary infections caused by a heterologous virus. a successful public health response to the growing global threat posed by flaviviruses necessitates the development of virus-specific diagnostic antigens. the flavivirus envelope (e) glycoprotein is the principle antigen sti ... | 2007 | 17157348 |
| detection of west nile virus in formalin-fixed, paraffin-embedded human tissues by rt-pcr: a useful adjunct to conventional tissue-based diagnostic methods. | west nile virus (wnv), a member of genus flavivirus, causes febrile illness, encephalitis, meningitis, myelitis, and occasional deaths in humans. although several reverse transcription-polymerase chain reaction (rt-pcr) assays have been developed for detection of wnv in serum, cerebrospinal fluid, and fresh tissues, the usefulness of wnv rt-pcr assays for rna extracted from formalin-fixed human tissues has not previously been demonstrated. | 2007 | 17161650 |
| murray valley encephalitis in an adult traveller complicated by long-term flaccid paralysis: case report and review of the literature. | murray valley encephalitis (mve) virus, a mosquito-borne flavivirus, is the most common cause of viral encephalitis in the tropical 'top end' of northern australia. clinical encephalitis due to mve virus has a mortality rate of approximately 30%, with a similar proportion of patients being left with significant neurological deficits. we report the case of a 25-year-old man from the uk who acquired mve while travelling through northern australia. he required prolonged admission to the intensive c ... | 2007 | 17161855 |
| construction and biological properties of yellow fever 17d/dengue type 1 recombinant virus. | dengue virus, a mosquito-borne flavivirus, is one of the most formidable public health threats in tropical and subtropical regions. as yet, there is no licensed vaccine to protect against the disease. a chimeric yellow fever (yf) 17d/dengue (den) type 1 virus was constructed by replacing the pre-membrane and envelope genes of yf 17d virus with those from den 1 vemir95 virus, a venezuelan isolate. the chimeric yf 17d/den 1 vemir95 virus was regenerated from full-length infectious clones stably pr ... | 2007 | 17169387 |
| genetic characterization of tick-borne flaviviruses: new insights into evolution, pathogenetic determinants and taxonomy. | here, we analyze the complete coding sequences of all recognized tick-borne flavivirus species, including gadgets gully, royal farm and karshi virus, seabird-associated flaviviruses, kadam virus and previously uncharacterized isolates of kyasanur forest disease virus and omsk hemorrhagic fever virus. significant taxonomic improvements are proposed, e.g. the identification of three major groups (mammalian, seabird and kadam tick-borne flavivirus groups), the creation of a new species (karshi viru ... | 2007 | 17169393 |
| characterization of the west nile virus protease substrate specificity and inhibitors. | west nile virus (wnv), a mosquito-borne member of flaviviridae, is a human pathogen causing widespread disease for which there is no vaccine or chemotherapy. the two-component viral serine protease consists of a heterodimeric complex between the hydrophilic domain of the cofactor, ns2b (ns2bh) and the protease domain (ns3-pro). the protease is essential for polyprotein processing followed by assembly of viral replicase and genome replication. therefore, the protease is an excellent target for de ... | 2007 | 17188926 |
| expression and purification of a two-component flaviviral proteinase resistant to autocleavage at the ns2b-ns3 junction region. | regulated proteolysis of the polyprotein precursor of west nile virus (wnv) by the essential ns2b-ns3(pro)tease, a promising drug target for wnv inhibitors, is required for the propagation of infectious virions. structural and drug design studies, however, require pilot-scale quantities of a pure and catalytically active wnv protease that is resistant to self-proteolysis. autolytic cleavage at the ns2b-ns3 boundary leads to individual, non-covalently associated, ns2b and ns3 domains, together wi ... | 2007 | 17189703 |
| caspase 3-dependent cell death of neurons contributes to the pathogenesis of west nile virus encephalitis. | west nile virus (wnv) is a neurotropic, arthropod-borne flavivirus that has become a significant global cause of viral encephalitis. to examine the mechanisms of wnv-induced neuronal death and the importance of apoptosis in pathogenesis, we evaluated the role of a key apoptotic regulator, caspase 3. wnv infection induced caspase 3 activation and apoptosis in the brains of wild-type mice. notably, congenic caspase 3(-/-) mice were more resistant to lethal wnv infection, although there were no sig ... | 2007 | 17192305 |
| full-length sequencing and genomic characterization of bagaza, kedougou, and zika viruses. | many members of the genus flavivirus are the agents of important diseases of humans, livestock, and wildlife. currently, no complete genome sequence is available for the three african viruses, bagaza, zika, and kedougou viruses, each representing a distinct virus subgroup according to the latest virus classification. in this study, we obtained a complete genome sequence of each of those three viruses and characterized the open reading frames (orfs) with respect to gene sizes, cleavage sites, pot ... | 2007 | 17195954 |
| the envelope glycoprotein domain iii of dengue virus serotypes 1 and 2 inhibit virus entry. | dengue virus (dv) is a flavivirus and its urban transmission is maintained largely by its mosquito vectors and vertebrate host, often human. in this study, investigation was carried out on the involvement of domain iii of the envelope (e) glycosylated protein of dengue virus serotypes 1 and 2 (dv-1 and dv-2 diii) in binding to host cell surfaces, thus mediating virus entry. domain iii protein of flavivirus can also serve as an attractive target in inhibiting virus entry. the respective dv diii p ... | 2007 | 17196419 |
| viral infections of the central nervous system in brazil. | epidemiological studies have shown that most central nervous system (cns) infections are viral. the objective of this study is to contribute to the knowledge base concerning viral cns infections in ribeirão preto, brazil. | 2007 | 17198733 |
| role of the mutant spectrum in adaptation and replication of west nile virus. | west nile virus (wnv) has successfully spread throughout the usa, canada, mexico, the caribbean and parts of central and south america since its 1999 introduction into north america. despite infecting a broad range of both mosquito and avian species, the virus remains highly genetically conserved. this lack of evolutionary change over space and time is common with many arboviruses and is frequently attributed to the adaptive constraints resulting from the virus cycling between vertebrate hosts a ... | 2007 | 17325359 |
| purification and crystallization of kokobera virus helicase. | kokobera virus is a mosquito-borne flavivirus belonging, like west nile virus, to the japanese encephalitis virus serocomplex. the flavivirus genus is characterized by a positive-sense single-stranded rna genome. the unique open reading frame of the viral rna is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the ns3 gene that encodes a c-terminal helicase domain consisting of 431 ... | 2007 | 17329812 |
| interference in dengue virus adsorption and uncoating by carrageenans. | this study demonstrated that the lambda- and iota-carrageenans, sulfated polysaccharides containing linear chains of galactopyranosyl residues, are potent inhibitors of dengue virus type 2 (denv-2) and 3 (denv-3) multiplication in vero and hepg2 cells, with values of effective concentration 50% from 0.14 to 4.1 microg/ml. this activity was assayed by plaque reduction, virus yield inhibition and antigen expression tests, and was independent of the input multiplicity of infection in the range 0.00 ... | 2007 | 17337028 |
| functional characterization of cis and trans activity of the flavivirus ns2b-ns3 protease. | flaviviruses are serious human pathogens for which treatments are generally lacking. the proteolytic maturation of the 375-kda viral polyprotein is one target for antiviral development. the flavivirus serine protease consists of the n-terminal domain of the multifunctional nonstructural protein 3 (ns3) and an essential 40-residue cofactor (ns2b(40)) within viral protein ns2b. the ns2b-ns3 protease is responsible for all cytoplasmic cleavage events in viral polyprotein maturation. this study desc ... | 2007 | 17337448 |
| monitoring of usutu virus activity and spread by using dead bird surveillance in austria, 2003-2005. | usutu virus has been causing avian mortality in austria since its emergence in 2001. between 2003 and 2005 a total of 504 dead birds were examined by reverse-transcriptase polymerase chain reaction and immunohistochemistry for the presence of usutu virus nucleic acid and antigen, respectively. in 2003, 92 birds (out of 177 birds) belonging to five different species were positive, while in 2004, only 11 (of 224) birds, and in 2005, 4 (of 103) birds proved positive, all of which were blackbirds (t ... | 2007 | 17346908 |
| assessing flavivirus, lentivirus, and herpesvirus exposure in free-ranging ring-tailed lemurs in southwestern madagascar. | the ring-tailed lemur (lemur catta) is an endangered species found in southwestern madagascar, and understanding infectious disease susceptibility is an essential step towards the preservation of wild and captive lemur populations. lemurs are primates that are widely dispersed throughout the island of madagascar and may serve as hosts or reservoirs for zoonotic infections. the aim of this study was to determine the prevalence of antibodies to west nile virus (wnv), simian immunodeficiency virus ... | 2007 | 17347392 |
| c-src protein kinase inhibitors block assembly and maturation of dengue virus. | dengue virus is a mosquito-borne flavivirus that represents an important emerging infectious disease and is an international health concern. currently, there is no vaccine or effective antiviral therapy to prevent or to treat dengue virus infection. the slow progress in developing antiviral agents might be alleviated by the availability of efficient high-throughput anti-dengue virus screening assays. in this study, we report an immunofluorescence image-based assay suitable for identification of ... | 2007 | 17360676 |
| alkhurma hemorrhagic fever virus in ornithodoros savignyi ticks. | evidence for the tickborne nature of alkhurma hemorrhagic fever virus (ahfv) is indirect because ahfv has not been detected in arthropods. one ornithodoros savignyi tick from saudi arabia contained ahfv rna. this is the first direct evidence that ahfv is a tickborne flavivirus and confirms the association between human ahfv cases and tickbite history. | 2007 | 17370534 |
| west nile virus strain kunjin ns5 polymerase is a phosphoprotein localized at the cytoplasmic site of viral rna synthesis. | using west nile virus strain kunjin virus (wnv(kun)) as a model system for flavivirus replication, we showed that the virus replication complex (rc) is associated with the dsrna template located in induced membranes only in the cytoplasm. in this report we established for the first time that the rna-dependent rna polymerase ns5 is located in flavivirus-induced membranes, including the site of viral rna replication. we found no evidence for nuclear localization of the essential rc components ns5 ... | 2007 | 17374759 |
| a detailed mutagenesis study of flavivirus cross-reactive epitopes using west nile virus-like particles. | human flavivirus infections elicit virus species-specific and cross-reactive immune responses. the flavivirus envelope (e) glycoprotein is the primary antigen inducing protective immunity; however, the presence of cross-reactive antibodies in human sera creates problems for serodiagnosis. using a west nile virus-like particle system, we performed mutagenesis across all three e protein functional domains to identify epitope determinants for a panel of monoclonal antibodies (mabs) raised against d ... | 2007 | 17374760 |
| in situ reactions of monoclonal antibodies with a viable mutant of murray valley encephalitis virus reveal an absence of dimeric ns1 protein. | studies on the ns1 protein of flaviviruses have concluded that formation of a stable homodimer is required for virus replication. however, previous work has reported that substitution of a conserved proline by leucine at residue 250 in ns1 of kunjin virus (kunv) eliminated dimerization, but allowed virus replication to continue. to assess whether this substitution has similar effects on other flaviviruses, it was introduced into an infectious clone of murray valley encephalitis virus (mvev). con ... | 2007 | 17374761 |
| identification of dengue virus in respiratory specimens from a patient who had recently traveled from a region where dengue virus infection is endemic. | dengue is the most important arthropod-borne viral disease, and it is a major public health problem in subtropical and tropical regions. the virus is transmitted to humans by the bite of infected female mosquitoes of the genus aedes. the global resurgence of dengue is thought to be due to failure to control the aedes populations, uncontrolled urbanization, population growth, climate change, and increased airplane travel. in this paper we describe the methods used to detect dengue virus infection ... | 2007 | 17376878 |
| [immunochemical properties of west nile virus protein prm and protein m c-end]. | complementary dna fragments (nucleotides 466-966 and 878-1088) encoding prm protein and polypeptide m31-75-e1-30 of west nile virus (wnv), strain leiv-vlg99-27889-human, were obtained and cloned. recombinant polypeptides prm and m3175-e1-30 having amino acid sequences corresponding to the cloned cdna fragments were purified by affinity chromatography. according to elisa and western blotting prm protein interacted with polyclonal antibodies against wnv. this is indicative the immunochemical simil ... | 2007 | 17380886 |
| membrane-containing viruses with icosahedrally symmetric capsids. | viruses with an icosahedrally symmetric protein capsid and a membrane infect hosts from all three domains of life. similar architectural principles are shared by different viral families, as exemplified by double-stranded dna viruses such as prd1 and stiv. during virus assembly, the membrane lipids are selectively acquired from the host cell. the x-ray structure of bacteriophage prd1 revealed that the lipids are asymmetrically distributed between the two leaflets and facet length is controlled b ... | 2007 | 17387010 |
| genetic and phenotypic differences between isolates of murray valley encephalitis virus in western australia, 1972-2003. | murray valley encephalitis virus (mvev) is a medically important mosquito-borne flavivirus found in australia and papua new guinea (png). partial envelope gene nucleotide sequences of 28 isolates of mvev from western australia (wa) between 1972 and 2003 were aligned and compared phylogenetically with the prototype mve-1-51 from victoria in 1951 and isolates from northern queensland and png. monoclonal antibody-binding patterns were also investigated. results showed that the majority of isolates ... | 2007 | 17393295 |
| structural evidence for regulation and specificity of flaviviral proteases and evolution of the flaviviridae fold. | pathogenic members of the flavivirus family, including west nile virus (wnv) and dengue virus (dv), are growing global threats for which there are no specific treatments. the two-component flaviviral enzyme ns2b-ns3 cleaves the viral polyprotein precursor within the host cell, a process that is required for viral replication. here, we report the crystal structure of wnv ns2b-ns3pro both in a substrate-free form and in complex with the trypsin inhibitor aprotinin/bpti. we show that aprotinin bind ... | 2007 | 17400917 |
| development and evaluation of sybr green i-based one-step real-time rt-pcr assay for detection and quantitation of japanese encephalitis virus. | one-step sybr green i-based real-time rt-pcr assay for rapid detection as well as quantitation of japanese encephalitis virus (jev) in acute-phase patient csf samples by targeting the ns3 gene was developed. the assay developed in this study was found to be more sensitive as compared to conventional rt-pcr. the specificity of the reported assay system was established through melting curve analysis as well as by cross-reactivity studies with related members of flavivirus. the applicability of rea ... | 2007 | 17403544 |
| bird species potentially involved in introduction, amplification, and spread of west nile virus in a mediterranean wetland, the camargue (southern france). | west nile virus (wnv) is a mosquito-transmitted flavivirus with a transmission cycle involving birds as amplifying hosts. wild birds are also believed to carry wnv over large distances and are able to introduce it into new areas during migration and dispersal. in this paper, our objective is to provide lists of birds potentially involved in the introduction, the amplification and the spread of wnv in the camargue, a mediterranean wetland in the south of france where several wnv outbreaks have oc ... | 2007 | 17417954 |
| early evening questing and oviposition activity by the culex (diptera: culicidae) vectors of west nile virus in northeastern north america. | to determine whether the culex (diptera: culicidae) mosquitoes that transmit west nile virus (family flaviviridae, genus flavivirus, wnv) in the northeastern united states seek hosts and oviposit contemporaneously, we recorded when these mosquitoes attacked caged birds and when they deposited eggs. they traversed oviposition sites most frequently approximately 2 h after astronomical sunset, and eggs generally were deposited at that time. although they most frequently approached avian hosts appro ... | 2007 | 17427688 |
| is nonviremic transmission of west nile virus by culex mosquitoes (diptera: culicidae) nonviremic? | inter- and intraspecific transfer of west nile virus (family flaviviridae, genus flavivirus, wnv) occurred infrequently when donor culex tarsalis coquillett fed concurrently on house finches with recipient culex quinquefasciatus say and cx. tarsalis. five of six of these house finches had wnv in blood samples collected by jugular venipuncture 30-45 min postfeeding, with titers ranging from 2.3 to 4.2 log10 plaque-forming units (pfu)/ml. after 2-wk incubation at 26 degrees c, three cx. quinquefas ... | 2007 | 17427700 |
| does feeding on infected mosquitoes (diptera: culicidae) enhance the role of song sparrows in the transmission of arboviruses in california? | song sparrows, melopiza melodia, inoculated subcutaneously with either western equine encephalomyelitis virus (family togaviridae, genus alphavirus, weev) or west nile virus (family flaviviridae, genus flavivirus, wnv) developed elevated viremias, and they were considered to be competent experimental hosts for both viruses. however, birds that ingested from three to 20 mosquitoes containing comparable amounts of either weev or wnv failed to become infected, indicating limited oral susceptibility ... | 2007 | 17427703 |
| ability of transstadially infected ixodes pacificus (acari: ixodidae) to transmit west nile virus to song sparrows or western fence lizards. | the hypothesis that ixodes pacificus cooley & kohls (acari: ixodidae) may serve as a reservoir and vector of west nile virus (family flaviviridae, genus flavivirus, wnv) in california was tested by determining the ability of this tick species to become infected with the ny99 strain of wnv while feeding on viremic song sparrows, to maintain the infection transstadially, and then to transmit wnv to recipient naive song sparrows and western fence lizards during the nymphal stage. the percentage of ... | 2007 | 17427704 |
| effect of cantharidin, cephalotaxine and homoharringtonine on "in vitro" models of hepatitis b virus (hbv) and bovine viral diarrhoea virus (bvdv) replication. | the effect as antiviral agents versus viral hepatitis b and c of three compounds purified from natural products commonly used as remedies in traditional chinese medicine, cantharidin, cephalotaxine and homoharingtonine, was investigated. to assess the activity of these compounds against flavivirus, we used bovine viral diarrhoea virus (bvdv) as a surrogate for hepatitis c virus (hcv). anti-bvdv activity was determined by reduction in bvdv-rna production and protection of infected embryonic bovin ... | 2007 | 17458779 |
| the opioid receptor antagonist, naloxone, protects spinal motor neurons in a murine model of alphavirus encephalomyelitis. | spread of neuroadapted sindbis virus (nsv) to motor neurons (mn) of the spinal cord (sc) causes severe hind limb weakness in c57bl/6 mice and models the paralysis that can accompany alphavirus and flavivirus encephalomyelitis in humans. the fate of spinal mn dictates the severity of nsv-induced paralysis, and recent data suggest that mn damage can occur indirectly via the actions of activated microglial cells. because the opioid receptor antagonist, naloxone (nal), blocks microglial-mediated neu ... | 2007 | 17459376 |
| essential role of dengue virus envelope protein n glycosylation at asparagine-67 during viral propagation. | dengue virus envelope protein (e) contains two n-linked glycosylation sites, at asn-67 and asn-153. the glycosylation site at position 153 is conserved in most flaviviruses, while the site at position 67 is thought to be unique for dengue viruses. n-linked oligosaccharide side chains on flavivirus e proteins have been associated with viral morphogenesis, infectivity, and tropism. here, we examined the relevance of each n-linked glycan on dengue virus e protein by removing each site in the contex ... | 2007 | 17459925 |
| identification of residues critical for the interferon antagonist function of langat virus ns5 reveals a role for the rna-dependent rna polymerase domain. | all pathogenic flaviviruses examined thus far inhibit host interferon (ifn) responses by suppressing the janus kinase-signal transducer and activator of transcription (jak-stat) pathway. both langat virus (lgtv; a member of the tick-borne encephalitis virus serogroup) and japanese encephalitis virus use the nonstructural protein ns5 to suppress jak-stat signaling. however, ns5 is also critical to virus replication, contributing methyltransferase and rna-dependent rna polymerase (rdrp) activities ... | 2007 | 17459929 |
| functional determinants of ns2b for activation of japanese encephalitis virus ns3 protease. | japanese encephalitis virus (jev) is a mosquito-borne flavivirus, causing severe central nerve system diseases without specific treatments. the ns2b-ns3 protease of flaviviruses mediates several cleavages on the flavivirus polyprotein, being believed to be a target for antiviral therapy. ns2b is the cofactor of the viral serine protease, correlating with stabilization and substrate recognition of the ns3 protease. in this study, we investigate the functional determinants in the jev ns2b for the ... | 2007 | 17467838 |
| structural bases for substrate recognition and activity in meaban virus nucleoside-2'-o-methyltransferase. | viral methyltransferases are involved in the mrna capping process, resulting in the transfer of a methyl group from s-adenosyl-l-methionine to capped rna. two groups of methyltransferases (mtases) are known: (guanine-n7)-methyltransferases (n7mtases), adding a methyl group onto the n7 atom of guanine, and (nucleoside-2'-o-)-methyltransferases (2'omtases), adding a methyl group to a ribose hydroxyl. we have expressed and purified two constructs of meaban virus (mv; genus flavivirus) ns5 protein m ... | 2007 | 17473012 |
| [synthetic fragments of the ns1 protein of the tick-borne encephalitis virus exhibiting a protective effect]. | potentially immunoactive regions of the ns1 nonstructural protein of the tick-borne encephalitis virus that can stimulate the antibody formation in vivo and protect animals from this disease were chosen on the basis of theoretical calculations. eleven 16- to 27-aa peptides containing the chosen regions were synthesized. the ability of the free peptides (without any high-molecular-mass carrier) to stimulate the production of antipeptide antibodies in mice of three lines and ensure the formation o ... | 2007 | 17476983 |
| conservation of the pentanucleotide motif at the top of the yellow fever virus 17d 3' stem-loop structure is not required for replication. | the pentanucleotide (pn) sequence 5'-cacag-3' at the top of the 3' stem-loop structure of the flavivirus genome is well conserved in the arthropod-borne viruses but is more variable in flaviviruses with no known vector. in this study, the sequence requirements of the pn motif for yellow fever virus 17d (yfv) replication were determined. in general, individual mutations at either the second, third or fourth positions were tolerated and resulted in replication-competent virus. mutations at the fif ... | 2007 | 17485534 |
| tick-borne flavivirus infection in ixodes scapularis larvae: development of a novel method for synchronous viral infection of ticks. | following a bite from an infected tick, tick-borne flaviviruses cause encephalitis, meningitis and hemorrhagic fever in humans. although these viruses spend most of their time in the tick, little is known regarding the virus-vector interactions. we developed a simple method for synchronously infecting ixodes scapularis larvae with langat virus (lgtv) by immersion in media containing the virus. this technique resulted in approximately 96% of ticks becoming infected. lgtv infection and replication ... | 2007 | 17490700 |
| prevalence of west nile virus neutralizing antibodies in colonial aquatic birds in southern spain. | the rapid expansion of west nile virus (wnv) throughout the new world has raised interest in understanding the population dynamics and patterns of dispersal of emerging infectious diseases by wildlife. wnv affects humans, although its main reservoirs are various species of birds. here we analyse the prevalence of wnv-neutralizing antibodies in nearly full-grown chicks belonging to seven different species of colonial waterbirds at three localities in southern spain. chicks with neutralizing antib ... | 2007 | 17497333 |
| interaction of tia-1/tiar with west nile and dengue virus products in infected cells interferes with stress granule formation and processing body assembly. | the west nile virus minus-strand 3' terminal stem loop (sl) rna was previously shown to bind specifically to cellular stress granule (sg) components, t cell intracellular antigen-1 (tia-1) and the related protein tiar. in vitro tiar binding was 10 times more efficient than tia-1. the 3'(-)sl functions as the promoter for genomic rna synthesis. colocalization of tiar and tia-1 with the viral replication complex components dsrna and ns3 was observed in the perinuclear regions of west nile virus- a ... | 2007 | 17502609 |
| characterization of the dengue virus envelope glycoprotein expressed in pichia pastoris. | the full-length and truncated forms of recombinant envelope (e) glycoprotein from dengue virus type 1, singapore strain s275/90 were expressed in the yeast, pichia pastoris, using a secretory vector. a truncated form of the e protein in which the transmembrane domain was deleted was secreted successfully into the culture medium. the e protein was also co-expressed with c and prm proteins using a non-secretory yeast vector. the co-expression of c, prm and e proteins resulted in the spontaneous fo ... | 2007 | 17502678 |
| combinatorial computational approaches to identify tetracycline derivatives as flavivirus inhibitors. | limited structural information of drug targets, cellular toxicity possessed by lead compounds, and large amounts of potential leads are the major issues facing the design-oriented approach of discovering new leads. in an attempt to tackle these issues, we have developed a process of virtual screening based on the observation that conformational rearrangements of the dengue virus envelope protein are essential for the mediation of viral entry into host cells via membrane fusion. screening was bas ... | 2007 | 17502914 |
| west nile virus encephalitis: sequential histopathological and immunological events in a murine model of infection. | west nile virus (wnv) has emerged as an important cause of encephalitis in humans and horses in north america. although there is significant knowledge about the pathogenesis of disease caused by this flavivirus and about the immunity against it, no reports exist describing the sequence of pathological changes and their correlation to the immune response in the brain following infection with wnv. in this report the authors describe the major histopathological changes, as well as changes in cytoki ... | 2007 | 17505981 |
| structural and functional comparison of the non-structural protein 4b in flaviviridae. | flaviviridae are evolutionarily related viruses, comprising the hepatitis c virus (hcv), with the non-structural protein 4b (ns4b) as one of the least characterized proteins. ns4b is located in the endoplasmic reticulum membrane and is assumed to be a multifunctional protein. however, detailed structure information is missing. the hydrophobic nature of ns4b is a major difficulty for many experimental techniques. we applied bioinformatics methods to analyse structural and functional properties of ... | 2007 | 17507273 |
| computational analysis and identification of amino acid sites in dengue e proteins relevant to development of diagnostics and vaccines. | we have identified 72 completely conserved amino acid residues in the e protein of major groups of the flavivirus genus by computational analyses. in the dengue species we have identified 12 highly conserved sequence regions, 186 negatively selected sites, and many dengue serotype-specific negatively selected sites. the flavivirus-conserved sites included residues involved in forming six disulfide bonds crucial for the structural integrity of the protein, the fusion motif involved in viral infec ... | 2007 | 17508277 |
| progress for dengue virus diseases. towards the ns2b-ns3pro inhibition for a therapeutic-based approach. | transmitted by the aedes aegypti mosquito, the dengue virus is the etiological agent of dengue fever, dengue hemorrhagic fever and dengue shock syndrome, and, as such, is a significant factor in the high death rate found in most tropical and subtropical areas of the world. dengue diseases are not only a health burden to developing countries, but pose an emerging problem worldwide. the immunopathological mechanisms appear to include a complex series of immune responses. a rapid increase in the le ... | 2007 | 17509079 |
| monoclonal antibody-mediated enhancement of dengue virus infection in vitro and in vivo and strategies for prevention. | infection with dengue virus (denv) or any other flavivirus induces cross-reactive, but weakly neutralizing or nonneutralizing, antibodies that recognize epitopes involving the fusion peptide in the envelope glycoprotein. humanized mab igg 1a5, derived from a chimpanzee, shares properties of cross-reactive antibodies. mab igg 1a5 up-regulated denv infection by a mechanism of antibody-dependent enhancement (ade) in a variety of fc receptor-bearing cells in vitro. a 10- to 1,000-fold increase of vi ... | 2007 | 17517625 |
| functional requirements of the yellow fever virus capsid protein. | although it is known that the flavivirus capsid protein is essential for genome packaging and formation of infectious particles, the minimal requirements of the dimeric capsid protein for virus assembly/disassembly have not been characterized. by use of a trans-packaging system that involved packaging a yellow fever virus (yfv) replicon into pseudo-infectious particles by supplying the yfv structural proteins using a sindbis virus helper construct, the functional elements within the yfv capsid p ... | 2007 | 17526891 |
| nuclear localization of dengue virus nonstructural protein 5 through its importin alpha/beta-recognized nuclear localization sequences is integral to viral infection. | dengue virus nonstructural protein 5 (ns5) is a large multifunctional protein with a central role in viral replication. we previously identified two nuclear localization sequences (nlss) within the central region of dengue virus type-2 (denv-2) ns5 ('anls' and 'bnls') that are recognized by the importin alpha/beta and importin beta1 nuclear transporters, respectively. here, we demonstrate the importance of the kinetics of ns5 nuclear localization to virus production for the first time and show t ... | 2007 | 17537211 |
| survival and replication of dengue-2 virus in diapausing eggs of aedes albopictus (diptera: culicidae). | survival and replication of dengue-2 virus (family flaviviridae, genus flavivirus, denv-2) was determined in diapausing eggs of aedes albopictus (skuse) (diptera: culicidae) to evaluate the importance of this mechanism for viral maintenance during adverse climatic conditions. infected and uninfected eggs of ae. albopictus were induced to diapause under low temperature and short photoperiod. virus was detected by reverse transcription-polymerase chain reaction and isolated in c6/36 cells from bot ... | 2007 | 17547236 |
| processing of capsid protein by cathepsin l plays a crucial role in replication of japanese encephalitis virus in neural and macrophage cells. | the flavivirus capsid protein not only is a component of nucleocapsids but also plays a role in viral replication. in this study, we found a small capsid protein in cells infected with japanese encephalitis virus (jev) but not in the viral particles. the small capsid protein was shown to be generated by processing with host cysteine protease cathepsin l. an in vitro cleavage assay revealed that cathepsin l cleaves the capsid protein between amino acid residues lys(18) and arg(19), which are well ... | 2007 | 17553875 |
| efficacy of a live attenuated tetravalent candidate dengue vaccine in naïve and previously infected cynomolgus macaques. | the development of a safe and effective vaccine against dengue is a public health priority. attempts to evaluate candidate vaccine formulations in human volunteers were largely unsuccessful, at least in part due to too high reactogenicity of some of the candidate vaccines tested. we evaluated a live attenuated tetravalent dengue vaccine candidate in flavivirus naïve and dengue virus type 3 immune non-human primates. immune responses were measured both at the humoral and the cellular level and th ... | 2007 | 17560694 |
| controlled peptide solvation in portion-mixing libraries of fret peptides: improved specificity determination for dengue 2 virus ns2b-ns3 protease and human cathepsin s. | the solubility of peptides in aqueous buffers used for the enzyme assays is a common limitation for all peptide libraries. in principle, the more water-soluble peptides are, the more susceptible they will be to peptidase hydrolysis. we have demonstrated that this bias can be circumvented in a portion-mixing fluorescence resonance energy transfer (fret) peptide library by introducing k (lysine in the d-form) in both termini of the peptides. this more solvated library and another one without the k ... | 2007 | 17563123 |
| early production of type i interferon during west nile virus infection: role for lymphoid tissues in irf3-independent interferon production. | infection of cells with flaviviruses in vitro is reduced by pretreatment with small amounts of type i interferon (ifn-alpha/beta). similarly, pretreatment of animals with ifn and experiments using mice defective in ifn signaling have indicated a role for ifn in controlling flavivirus disease in vivo. these data, along with findings that flavivirus-infected cells block ifn signaling, suggest that flavivirus infection can trigger an ifn response. to investigate ifn gene induction by the very first ... | 2007 | 17567689 |
| a comparison of concentration methods applied to non-infectious flavivirus recombinant antigens for use in diagnostic serological assays. | since the introduction of west nile virus into the united states in 1999, there has been a greater awareness of arboviruses, consequently, diagnostic testing for west nile virus and other arboviruses has increased both in u.s. and international public health laboratories. the centers for disease control and prevention/division of vector-borne infectious diseases/arbovirus diagnostic and reference laboratory produces and provides the serodiagnostic reagents which are not available commercially. r ... | 2007 | 17570536 |
| identification and characterization of rna-dependent rna polymerase activity in recombinant japanese encephalitis virus ns5 protein. | the complete nonstructural ns5 gene of japanese encephalitis virus (jev) was amplified and cloned into an expression vector. the ns5 protein was expressed in escherichia coli and purified by his-tag based affinity chromatography. this recombinant ns5 protein exhibited rna-dependent rna polymerase (rdrp) activity in vitro in the absence of other viral or cellular factors. the rna polymerase activity was dependent on divalent cations, and mn(2+) was found to be 20 times more effective than mg(2+) ... | 2007 | 17577613 |
| dnazyme-mediated inhibition of japanese encephalitis virus replication in mouse brain. | japanese encephalitis virus (jev) is an arthropod-borne flavivirus with a single-stranded rna genome containing non-coding regions (ncrs) at its 5' and 3'-ends. the ncrs have flavivirus-conserved sequences that are important for virus replication. here we describe dnazymes (dzs) that cleave the rna sequence of the 3'-ncr of jev genome in vitro. the nuclease-resistant dzs, containing phosphorothioate linkages, were efficiently taken up by mouse neuronal and glial cells, and addition of a continuo ... | 2007 | 17579579 |
| antibody recognition of cell surface-associated ns1 triggers fc-gamma receptor-mediated phagocytosis and clearance of west nile virus-infected cells. | previous studies have suggested that monoclonal antibodies (mabs) to flavivirus nonstructural protein-1 (ns-1) protect against infection in mice through an fc-gamma receptor-dependent pathway. to identify a specific mechanism, we evaluated the protective activity of anti-ns1 mabs to wnv using mice and cells with deficiencies of specific fc-gamma receptors. our results suggest that only mabs that recognize cell surface-associated ns1 trigger fc-gamma receptor i- and/or iv-mediated phagocytosis an ... | 2007 | 17582005 |
| ilheus virus isolate from a human, ecuador. | 2007 | 17582910 | |
| a multiplexed taqman assay for the detection of arthropod-borne flaviviruses. | arboviruses in the genus flavivirus are major causes of human disease worldwide, and yet they are widely under reported. this is partially due to the classical methods of detection, using virologic or immunologic techniques, which typically lack sensitivity and specificity or require biological containment facilities in order to manipulate infectious cultures. molecular detection assays based on broadly reactive (degenerate) primers also tend to have differential and lower sensitivity for many f ... | 2007 | 17583360 |
| [strokes caused by infection in the tropics]. | almost three out of every four people in the world who suffer a fatal stroke live in developing countries. a number of different tropical diseases may appear in europe in the coming years as a consequence of the demographic change that is being brought about by migratory flows. we review the main infectious causes of strokes in the tropics. | 2007 | 17583870 |
| thirteen to twenty-seven-year follow-up of patients with hepatitis c while transfusing or donating plasma. | hepatitis c virus is a hepatotrophic flavivirus infecting 170 million people worldwide and 3.2% people in china. we aim to investigate the clinical outcomes and hepatic histology of patients with hepatitis c in the north of china. | 2007 | 17591072 |
| epitope-blocking enzyme-linked immunosorbent assay to differentiate west nile virus from japanese encephalitis virus infections in equine sera. | west nile virus (wnv) is now widely distributed worldwide, except in most areas of asia where japanese encephalitis virus (jev) is distributed. considering the movement and migration of reservoir birds, there is concern that wnv may be introduced in asian countries. although manuals and guidelines for serological tests have been created in japan in preparedness for the introduction of wnv, differential diagnosis between wnv and jev may be complicated by antigenic cross-reactivities between these ... | 2007 | 17596430 |
| detection of west nile virus lineages 1 and 2 by real-time pcr. | west nile virus (wnv) is a flavivirus attracting worldwide attention because it has spread rapidly across the americas since its first appearance in new york city in 1999. several pcr-based diagnostic methods have been developed for the detection of wnv. the focus of these assays has been wnv lineage 1 which can be found worldwide, while lineage 2 viruses were thought to be endemic only in some regions of africa. however, both lineages may be imported from africa to europe by migrating birds. in ... | 2007 | 17604132 |
| cryo-electron microscopy and three-dimensional reconstructions of hepatitis c virus particles. | the structural details of hepatitis c virus (hcv) have been elusive because of the lack of a robust tissue culture system for producing an adequate amount of virions from infectious sources for in-depth three-dimensional (3d) structural analysis. using both negative-stain and cryo-electron microscopy (cryoem), we show that hcv virions isolated from cell culture have a rather uniform size of 500 a in diameter and that recombinantly expressed hcv-like particles (hcv-lps) have similar morphologic, ... | 2007 | 17618667 |
| flavivirus serology by western blot analysis. | the spread of west nile virus (wnv) across the united states into areas with endemic flavivirus activity has complicated serologic surveillance of seasonal virus activity and diagnosis of infected individuals. here we describe preliminary results from a comparison of serologic assays for flaviviruses: the reference plaque reduction neutralization test (prnt), enzyme immunoassay (eia), and a western blot (wb) in which crude viral lysates were electrophoresed and blotted onto nitrocellulose. human ... | 2007 | 17620648 |
| yellow fever virus ns3 protease: peptide-inhibition studies. | a recombinant form of yellow fever virus (yfv) ns3 protease, linked via a nonapeptide to the minimal ns2b co-factor sequence (cf40-gly-ns3pro190), was expressed in escherichia coli and shown to be catalytically active. it efficiently cleaved the fluorogenic tetrapeptide substrate bz-norleucine-lysine-arginine-arginine-amc, which was previously optimized for dengue virus ns2b/3 protease. a series of small peptidic inhibitors based on this substrate sequence readily inhibited its enzymic activity. ... | 2007 | 17622626 |
| crystal structure of the murray valley encephalitis virus ns5 methyltransferase domain in complex with cap analogues. | we have determined the high resolution crystal structure of the methyltransferase domain of the ns5 polypeptide from the murray valley encephalitis virus. this domain is unusual in having both the n7 and 2'-o methyltransferase activity required for cap 1 synthesis. we have also determined structures for complexes of this domain with nucleotides and cap analogues providing information on cap binding, based on which we suggest a model of how the sequential methylation of the n7 and 2'-o groups of ... | 2007 | 17622627 |
| complete genome characterization of rocio virus (flavivirus: flaviviridae), a brazilian flavivirus isolated from a fatal case of encephalitis during an epidemic in sao paulo state. | the flaviviruses of major medical importance in south american countries are yellow fever, dengue, saint louis encephalitis, west nile and rocio viruses. rocio virus (rocv) has been responsible for epidemics of severe encephalitis in brazil with a case-fatality rate of 10 % and development of sequelae in 20 % of the survivors. we have sequenced and characterized the entire genome of rocv for the first time, by determining the general traits of the open reading frame and the characteristics of vi ... | 2007 | 17622628 |
| biochemical characterization of a recombinant japanese encephalitis virus rna-dependent rna polymerase. | japanese encephalitis virus (jev) ns5 is a viral nonstructural protein that carries both methyltransferase and rna-dependent rna polymerase (rdrp) domains. it is a key component of the viral rna replicase complex that presumably includes other viral nonstructural and cellular proteins. the biochemical properties of jev ns5 have not been characterized due to the lack of a robust in vitro rdrp assay system, and the molecular mechanisms for the initiation of rna synthesis by jev ns5 remain to be el ... | 2007 | 17623110 |
| interaction between the cellular protein eef1a and the 3'-terminal stem-loop of west nile virus genomic rna facilitates viral minus-strand rna synthesis. | rnase footprinting and nitrocellulose filter binding assays were previously used to map one major and two minor binding sites for the cell protein eef1a on the 3'(+) stem-loop (sl) rna of west nile virus (wnv) (3). base substitutions in the major eef1a binding site or adjacent areas of the 3'(+) sl were engineered into a wnv infectious clone. mutations that decreased, as well as ones that increased, eef1a binding in in vitro assays had a negative effect on viral growth. none of these mutations a ... | 2007 | 17626087 |
| complex adenovirus-mediated expression of west nile virus c, prem, e, and ns1 proteins induces both humoral and cellular immune responses. | west nile virus (wnv), a member of the family flaviviridae, was first identified in africa in 1937. in recent years, it has spread into europe and north america. the clinical manifestations of wnv infection range from mild febrile symptoms to fatal encephalitis. two genetic lineages (lineages i and ii) are recognized; lineage ii is associated with mild disease, while lineage i has been associated with severe disease, including encephalitis. wnv has now spread across north america, significantly ... | 2007 | 17634508 |
| infection and vertical transmission of kamiti river virus in laboratory bred aedes aegypti mosquitoes. | kamiti river virus (krv) is an insect-only flavivirus that was isolated from field-collected ae. macintoshi mosquitoes in 1999, and is closely related to cell fusing agent virus. both of these viruses belong to the family flaviviridae, which also contains other viruses of medical importance, such as yellow fever virus, west nile virus and dengue. because ae. macintoshi is the only known natural host to krv, the main objective of this study was to establish the possibility that other mosquito hos ... | 2007 | 20337552 |
| surveillance of viral haemorrhagic fevers in ghana: entomological assessment of the risk of transmission in the northern regions. | summary | 2006 | 17496987 |
| [west nile virus: a reality in mexico]. | west nile virus (wnv) is a rna virus of the flaviridae, genus flavivirus family. it is a neuropathogenic virus causing disease in birds, horses and humans. wnvis transmitted by the vector mosquito culex sp. the virus life 's cycle includes mosquitoes as vectors and birds as natural hosts. humans are accidental hosts. since the introduction of the epidemiological surveillance program at the ministry ofhealth. we have documented 90 positive test results among birds out of 1,223 cases studied in me ... | 2006 | 17201112 |
| [inhibition of ifn-gamma receptor signaling by hepatitis c virus non-structural protein ns4b]. | the function of ns4b is incompletely understood. the aim of the study is to understand the influence of ns4b on anti-viral response. after cell line stably expressing ns4b established, the influence of ifn-alpha of different concentration on vsv was studied using plaque assay; cell expression profiling caused by ns4b was studied using dna microarray, and the ifngr1 fluorescence intensity was analyzed. our data showed that hcv-ns4b could suppress immuno-associated gene expression, in particular, ... | 2006 | 17172032 |
| characterization of sepik and entebbe bat viruses closely related to yellow fever virus. | yellow fever virus has a special place in medical history as the first animal virus isolated and as the prototype virus in the genus flavivirus, which contains many serious human pathogens. only recently, its closely related viruses within the group were identified phylogenetically. in this study, we obtained complete or near complete genome sequences of two viruses most closely related to yellow fever virus: sepik virus of papua new guinea and entebbe bat virus of africa. based on full-genomic ... | 2006 | 17172387 |
| oviposition activity patterns and west nile virus infection rates for members of the culex pipiens complex at different habitat types within the hybrid zone, shelby county, tn, 2002 (diptera: culicidae). | oviposition activity and west nile virus (family flaviviridae, genus flavivirus, wnv) infection rates were assessed for members of the culex pipiens complex from july through december 2002 by using gravid traps placed at four ecologically different sites in the southern portion of the hybrid zone in shelby county, tn. molecular assays identified three members of the cx. pipiens complex: cx. pipiens pipiens l., cx. p. quinquefasciatus say, and cx. p. pipiens-cx. p. quinquefasciatus hybrids (hybri ... | 2006 | 17162958 |