| morphological features of murray valley encephalitis virus infection in the central nervous system of swiss mice. | we have examined the histological and ultrastructural features of cns infection with murray valley encephalitis (mve) virus in mice inoculated with a virulent parental strain (bh3479). light microscopic examination revealed neuronal necrosis in the olfactory bulb and hippocampus of mve-infected brains by 5 days post-infection (pi). electron microscopy of these regions showed endoplasmic reticulum membrane proliferation, and tubular and spherical structures in the cisternae of the endoplasmic ret ... | 2000 | 10718862 |
| stimulation of dengue virus replication in cultured aedes albopictus (c6/36) mosquito cells by the antifungal imidazoles ketoconazole and miconazole. | replication of dengue type 3 virus in aedes albopictus c6/36 cells was enhanced more than 50-fold by addition of the antifungal imidazole derivative ketoconazole within the first 4 h of infection. the stimulatory effect was reflected in the yield of infectious virus and in levels of viral rna and protein synthesis. enhanced yields were observed also for other flaviviruses, including dengue type 2 virus and murray valley encephalitis virus. increased yields of dengue type 3 virus were not observe ... | 2000 | 10725192 |
| charged residues in the transmembrane domains of hepatitis c virus glycoproteins play a major role in the processing, subcellular localization, and assembly of these envelope proteins. | for most membrane proteins, the transmembrane domain (tmd) is more than just an anchor to the membrane. the tmds of hepatitis c virus (hcv) envelope proteins e1 and e2 are extreme examples of the multifunctionality of such membrane-spanning sequences. indeed, they possess a signal sequence function in their c-terminal half, play a major role in endoplasmic reticulum localization of e1 and e2, and are potentially involved in the assembly of these envelope proteins. these multiple functions are su ... | 2000 | 10729138 |
| early diagnosis of murray valley encephalitis by reverse transcriptase-polymerase chain reaction. | a 4-year-old aboriginal boy developed encephalitis due to murray valley encephalitis virus (mve) following an earlier infection with kunjin virus (kun). the illness was severe, resulting in cerebral atrophy and profound physical and intellectual disability. the earlier kun infection complicated his serological profile and delayed antibody responses to mve. by contrast, the reverse transcriptase-polymerase chain reaction (rt-pcr) assay detected mve in serum 3 days after the onset of illness and 4 ... | 2000 | 10740807 |
| a single intramuscular injection of recombinant plasmid dna induces protective immunity and prevents japanese encephalitis in mice. | plasmid vectors containing japanese encephalitis virus (jev) premembrane (prm) and envelope (e) genes were constructed that expressed prm and e proteins under the control of a cytomegalovirus immediate-early gene promoter. cos-1 cells transformed with this plasmid vector (je-4b clone) secreted jev-specific extracellular particles (eps) into the culture media. groups of outbred icr mice were given one or two doses of recombinant plasmid dna or two doses of the commercial vaccine jevax. all mice t ... | 2000 | 10756038 |
| detection of anti-arboviral immunoglobulin g by using a monoclonal antibody-based capture enzyme-linked immunosorbent assay. | monoclonal antibody (mab)-based capture enzyme-linked immunosorbent assays (elisas) for the detection of anti-arboviral immunoglobulin g (igg elisas) were developed for a comprehensive array of medically important arboviruses from the alphavirus, flavivirus, and bunyavirus genera. tests were optimized and standardized so that maximum homology could be maintained among working parameters for the different viral agents, enabling a wide range of viruses to be easily tested for at one time. mabs wer ... | 2000 | 10790108 |
| immunisation with gamma globulin to murray valley encephalitis virus and with an inactivated japanese encephalitis virus vaccine as prophylaxis against australian encephalitis: evaluation in a mouse model. | in northwestern australia, the flavivirus murray valley encephalitis (mve) poses a significant health risk to infants in some aboriginal communities, particularly during each wet season. while there are too few cases to warrant the development of a vaccine against mve, a safe, effective prophylaxis for these children is still urgently required. the use of passive transfer of human gamma globulin to mve or immunisation with a vaccine to the closely related japanese encephalitis (je) virus were in ... | 2000 | 10797383 |
| substitutions at the putative receptor-binding site of an encephalitic flavivirus alter virulence and host cell tropism and reveal a role for glycosaminoglycans in entry. | the flavivirus receptor-binding domain has been putatively assigned to a hydrophilic region (fg loop) in the envelope (e) protein. in some flaviviruses this domain harbors the integrin-binding motif arg-gly-asp (rgd). one of us has shown earlier that host cell adaptation of murray valley encephalitis virus (mve) can result in the selection of attenuated variants altered at e protein residue asp(390), which is part of an rgd motif. here, a full-length, infectious cdna clone of mve was constructed ... | 2000 | 10982329 |
| attenuation of tick-borne encephalitis virus by structure-based site-specific mutagenesis of a putative flavivirus receptor binding site. | the impact of a specific region of the envelope protein e of tick-borne encephalitis (tbe) virus on the biology of this virus was investigated by a site-directed mutagenesis approach. the four amino acid residues that were analyzed in detail (e308 to e311) are located on the upper-lateral surface of domain iii according to the x-ray structure of the tbe virus protein e and are part of an area that is considered to be a potential receptor binding determinant of flaviviruses. mutants containing si ... | 2000 | 11000232 |
| rapid detection of west nile virus from human clinical specimens, field-collected mosquitoes, and avian samples by a taqman reverse transcriptase-pcr assay. | the authors report on the development and application of a rapid taqman assay for the detection of west nile (wn) virus in a variety of human clinical specimens and field-collected specimens. oligonucleotide primers and fam- and tamra-labeled wn virus-specific probes were designed by using the nucleotide sequence of the new york 1999 wn virus isolate. the taqman assay was compared to a traditional reverse transcriptase (rt)-pcr assay and to virus isolation in vero cells with a large number ( app ... | 2000 | 11060069 |
| nitric oxide and virus infection. | nitric oxide (no) has complex and diverse functions in physiological and pathophysiological phenomena. the mechanisms of many events induced by no are now well defined, so that a fundamental understanding of no biology is almost established. accumulated evidence suggests that no and oxygen radicals such as superoxide are key molecules in the pathogenesis of various infectious diseases. no biosynthesis, particularly through expression of an inducible no synthase (inos), occurs in a variety of mic ... | 2000 | 11106932 |
| mosquito (diptera: culicidae) dispersal: implications for the epidemiology of japanese and murray valley encephalitis viruses in australia. | one hypothesis to explain the southern extension of japanese encephalitis (je) virus from papua new guinea into the torres strait islands in 1995 and to mainland australia in 1998 is the dispersal of infected mosquitoes, particularly culex annulirostris skuse from which je virus has been isolated repeatedly. to investigate whether this species disperses in this manner, mosquitoes were identified from 368 aerial kite trap collections operated at 50-310 m (altitude) at inland new south wales betwe ... | 2000 | 11126532 |
| molecular basis for attenuation of neurovirulence of a yellow fever virus/japanese encephalitis virus chimera vaccine (chimerivax-je). | a yellow fever virus (yfv)/japanese encephalitis virus (jev) chimera in which the structural proteins prm and e of yfv 17d are replaced with those of the jev sa14-14-2 vaccine strain is under evaluation as a candidate vaccine against japanese encephalitis. the chimera (yfv/jev sa14-14-2, or chimerivax-je) is less neurovirulent than is yfv 17d vaccine in mouse and nonhuman primate models (f. guirakhoo et al., virology 257:363-372, 1999; t. p. monath et al., vaccine 17:1869-1882, 1999). attenuatio ... | 2001 | 11134306 |
| innate resistance to flavivirus infection in mice controlled by flv is nitric oxide-independent. | innate resistance to flaviviruses in mice is active in the brain where it restricts virus replication. this resistance is controlled by a single genetic locus, flv, located on mouse chromosome 5 near the locus encoding the neuronal form of nitric oxide synthase (nos1). since nitric oxide (no) has been implicated in antiviral activity, its involvement in natural resistance to flaviviruses has been hypothesized. here we present data on no production before and during flavivirus infection in both b ... | 2001 | 11172102 |
| the emergence of west nile virus: the australian connection. | | 2000 | 11192291 |
| murray valley encephalitis in western australia in 2000, with evidence of southerly spread. | we describe the epidemiological and clinical features of human murray valley encephalitis (mve) and kunjin (kun) virus infections in western australia (wa) during march to july 2000. a case series was performed. for laboratory-confirmed cases, travel histories and clinical details were collected from patients, family members, friends or treating physicians. surveillance data from the sentinel chicken program and climatic conditions were reviewed. nine encephalitic cases of mve were recorded. eig ... | 2000 | 11225378 |
| antiviral cytotoxic t cells cross-reactively recognize disparate peptide determinants from related viruses but ignore more similar self- and foreign determinants. | we have investigated the reactivities of cytotoxic t (tc) cells against the two immunodominant, h-2k(k)-restricted determinants from the flavivirus: murray valley encephalitis virus (mve), mve(1785) (rehsgnei) and mve(1971) (degegrvi). the respective tc cell populations cross-reactively lysed target cells pulsed with determinants from the mve(1785)- and mve(1971)-corresponding positions of six other flaviviruses, despite low sequence homology in some cases. notably, anti-mve(1785) tc cells recog ... | 2001 | 11238625 |
| biophysical characterization and vector-specific antagonist activity of domain iii of the tick-borne flavivirus envelope protein. | the molecular determinants responsible for flavivirus host cell binding and tissue tropism are largely unknown, although domain iii of the envelope protein has been implicated in these functions. we examined the solution properties and antagonist activity of langat virus domain iii. our results suggest that domain iii adopts a stably folded structure that can mediate binding of tick-borne flaviviruses but not mosquito-borne flaviviruses to their target cells. three clusters of phylogenetically c ... | 2001 | 11264392 |
| high-throughput detection of west nile virus rna. | the recent outbreaks of west nile virus (wnv) in the northeastern united states and other regions of the world have made it essential to develop an efficient protocol for surveillance of wnv. in the present report, we describe a high-throughput procedure that combines automated rna extraction, amplification, and detection of wnv rna. the procedure analyzed 96 samples in approximately 4.5 h. a robotic system, the abi prism 6700 automated nucleic acid workstation, extracted rna and set up reaction ... | 2001 | 11283039 |
| west nile virus recombinant dna vaccine protects mouse and horse from virus challenge and expresses in vitro a noninfectious recombinant antigen that can be used in enzyme-linked immunosorbent assays. | introduction of west nile (wn) virus into the united states in 1999 created major human and animal health concerns. currently, no human or veterinary vaccine is available to prevent wn viral infection, and mosquito control is the only practical strategy to combat the spread of disease. starting with a previously designed eukaryotic expression vector, we constructed a recombinant plasmid (pcbwn) that expressed the wn virus prm and e proteins. a single intramuscular injection of pcbwn dna induced ... | 2001 | 11287553 |
| mutational evidence for an internal fusion peptide in flavivirus envelope protein e. | the envelope protein e of the flavivirus tick-borne encephalitis (tbe) virus promotes cell entry by inducing fusion of the viral membrane with an intracellular membrane after uptake by endocytosis. this protein differs from other well-studied viral and cellular fusion proteins because of its distinct molecular architecture and apparent lack of involvement of coiled coils in the low-ph-induced structural transitions that lead to fusion. a highly conserved loop (the cd loop), which resides at the ... | 2001 | 11287576 |
| adaptation of tick-borne encephalitis virus to bhk-21 cells results in the formation of multiple heparan sulfate binding sites in the envelope protein and attenuation in vivo. | propagation of the flavivirus tick-borne encephalitis virus in bhk-21 cells selected for mutations within the large surface glycoprotein e that increased the net positive charge of the protein. in the course of 16 independent experiments, 12 different protein e mutation patterns were identified. these were located in all three of the structural domains and distributed over almost the entire upper and lateral surface of protein e. the mutations resulted in the formation of local patches of predom ... | 2001 | 11356970 |
| modulation of transporter associated with antigen processing (tap)-mediated peptide import into the endoplasmic reticulum by flavivirus infection. | in contrast to many other viruses that escape the cellular immune response by downregulating major histocompatibility complex (mhc) class i molecules, flavivirus infection can upregulate their cell surface expression. previously we have presented evidence that during flavivirus infection, peptide supply to the endoplasmic reticulum is increased (a. müllbacher and m. lobigs, immunity 3:207-214, 1995). here we show that during the early phase of infection with different flaviviruses, the transport ... | 2001 | 11356974 |
| immunogenicity of two peptide determinants in the cytolytic t-cell response to flavivirus infection: inverse correlation between peptide affinity for mhc class i and t-cell precursor frequency. | we used the cd8+ cytotoxic t (tc) cell immune response against the flavivirus, murray valley encephalitis virus (mve), restricted by the h-2kk major histocompatibility complex (mhc) class i molecule, to investigate immunodominance. split-clone limiting dilution analysis revealed almost exclusive recognition of two peptides, mve1785 and mve1971, derived from the viral ns3 protein. the precursor frequency of mve-reactive tc cells was determined by limiting dilution analysis for cytotoxic function ... | 2001 | 11398809 |
| essential role of cyclization sequences in flavivirus rna replication. | a possible role in rna replication for interactions between conserved complementary (cyclization) sequences in the 5'- and 3'-terminal regions of flavivirus rna was previously suggested but never tested in vivo. using the m-fold program for rna secondary-structure predictions, we examined for the first time the base-pairing interactions between the covalently linked 5' genomic region (first ~160 nucleotides) and the 3' untranslated region (last ~115 nucleotides) for a range of mosquito-borne fla ... | 2001 | 11413342 |
| murray valley encephalitis virus surveillance and control initiatives in australia. national arbovirus advisory committee of the communicable diseases network australia. | mechanisms for monitoring murray valley encephalitis (mve) virus activity include surveillance of human cases, surveillance for activity in sentinel animals, monitoring of mosquito vectors and monitoring of weather conditions. the monitoring of human cases is only one possible trigger for public health action and the additional surveillance systems are used in concert to signal the risk of human disease, often before the appearance of human cases. mosquito vector surveillance includes mosquito t ... | 2001 | 11432524 |
| murray valley encephalitis in mt isa, north queensland. tropical public health unit network, queensland health. | | 2001 | 11432525 |
| central australian mve update, 2001. | | 2001 | 11432526 |
| australian encephalitis: sentinel chicken surveillance programme. | | 2001 | 11432527 |
| attenuation of murray valley encephalitis virus by site-directed mutagenesis of the hinge and putative receptor-binding regions of the envelope protein. | molecular determinants of virulence in flaviviruses cluster in two regions on the three-dimensional structure of the envelope (e) protein; the base of domain ii, believed to serve as a hinge during ph-dependent conformational change in the endosome, and the lateral face of domain iii, which contains an integrin-binding motif arg-gly-asp (rgd) in mosquito-borne flaviviruses and is believed to form the receptor-binding site of the protein. in an effort to better understand the nature of attenuatio ... | 2001 | 11462041 |
| determination of the intramolecular disulfide bond arrangement and biochemical identification of the glycosylation sites of the nonstructural protein ns1 of murray valley encephalitis virus. | the 12 cysteine residues in the flavivirus ns1 protein are strictly conserved, suggesting that they form disulfide bonds that are critical for folding the protein into a functional structure. in this study, we examined the intramolecular disulfide bond arrangement of ns1 of murray valley encephalitis virus and elucidated three of the six cysteine-pairing arrangements. disulfide linkages were identified by separating tryptic-digested ns1 by reverse-phase high pressure liquid chromatography and an ... | 2001 | 11514736 |
| dengue and other emerging flaviviruses. | flaviviruses are among the most important emerging viruses known to man. most are arboviruses (arthropod-borne) being transmitted by mosquitoes or ticks. they derived from a common ancestor 10-20000 years ago and are evolving rapidly to fill new ecological niches. many are spreading to new geographical areas and causing increased numbers of infections. traditionally, three clinical syndromes are recognized: fever-arthralgia-rash, viral haemorrhagic fever, and neurological disease, though for som ... | 2001 | 11531316 |
| effector cytolotic function but not ifn-gamma production in cytotoxic t cells triggered by virus-infected target cells in vitro. | cytolysis and interferon(ifn)-gamma production are two independent effector functions of activated cytotoxic t (tc) cells. we have used the tc-cell response against the flavivirus, murray valley encephalitis virus (mve), to investigate the requirements for inducing these two functions with regard to antigen-concentration and cd8 coreceptor involvement. cognate peptide-pulsed target cells triggered cytolysis by primary ex vivo mve-immune as well as in vitro peptide-restimulated splenocytes at low ... | 2001 | 11555403 |
| ross river virus transmission, infection, and disease: a cross-disciplinary review. | ross river virus (rrv) is a fascinating, important arbovirus that is endemic and enzootic in australia and papua new guinea and was epidemic in the south pacific in 1979 and 1980. infection with rrv may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. rrv disease notifications in australia average 5,000 per year. the first well-described outbreak occurred in 1928. during world war ii there were more outbreaks, and the name ep ... | 2001 | 11585790 |
| murray valley encephalitis. | | 2001 | 11596721 |
| australian encephalitis: sentinel chicken surveillance programme. | | 2001 | 11596723 |
| assembly and maturation of the flavivirus kunjin virus appear to occur in the rough endoplasmic reticulum and along the secretory pathway, respectively. | the intracellular assembly site for flaviviruses in currently not known but is presumed to be located within the lumen of the rough endoplasmic reticulum (rer). building on previous studies involving immunofluorescence (if) and cryoimmunoelectron microscopy of kunjin virus (kun)-infected cells, we sought to identify the steps involved in the assembly and maturation of kun. thus, using antibodies directed against envelope protein e in if analysis, we found the accumulation of e within regions coi ... | 2001 | 11602720 |
| neuroadapted yellow fever virus 17d: genetic and biological characterization of a highly mouse-neurovirulent virus and its infectious molecular clone. | a neuroadapted strain of yellow fever virus (yfv) 17d derived from a multiply mouse brain-passaged virus (porterfield yf17d) was additionally passaged in scid and normal mice. the virulence properties of this virus (spyf) could be distinguished from nonneuroadapted virus (yf5.2iv, 17d infectious clone) by decreased average survival time in scid mice after peripheral inoculation, decreased average survival time in normal adult mice after intracerebral inoculation, and occurrence of neuroinvasiven ... | 2001 | 11602731 |
| experimental infections of pigs with japanese encephalitis virus and closely related australian flaviviruses. | the flavivirus japanese encephalitis (je) virus has recently emerged in the australasian region. to investigate the involvement of infections with related enzootic flaviviruses, namely murray valley encephalitis (mve) virus and kunjin (kun) virus, on immunity of pigs to je virus and to provide a basis for interpretation of serologic data, experimental infections were conducted with combinations of these viruses. antibody responses to primary and secondary infections were evaluated using panels o ... | 2001 | 11693888 |
| single mutation in the flavivirus envelope protein hinge region increases neurovirulence for mice and monkeys but decreases viscerotropism for monkeys: relevance to development and safety testing of live, attenuated vaccines. | a chimeric yellow fever (yf) virus/japanese encephalitis (je) virus vaccine (chimerivax-je) was constructed by insertion of the prm-e genes from the attenuated je virus sa14-14-2 vaccine strain into a full-length cdna clone of yf 17d virus. passage in fetal rhesus lung (frhl) cells led to the emergence of a small-plaque virus containing a single met-->lys amino acid mutation at e279, reverting this residue from the sa14-14-2 to the wild-type amino acid. a similar virus was also constructed by si ... | 2002 | 11799188 |
| single rapid taqman fluorogenic probe based pcr assay that detects all four dengue serotypes. | public health laboratories require rapid diagnosis of dengue outbreaks for application of measures such as vector control. we have developed a rapid single fluorogenic probe-based polymerase chain reaction assay for the detection of all four dengue serotypes (fudrt-pcr). the method employs primers and probe that are complementary to the evolutionarily conserved 3' untranslated region of the dengue genome. the assay detected viral rna of strains of all four dengue serotypes but not of the flavivi ... | 2002 | 11857532 |
| lack of both fas ligand and perforin protects from flavivirus-mediated encephalitis in mice. | the mechanism by which encephalitic flaviviruses enter the brain to inflict a life-threatening encephalomyelitis in a small percentage of infected individuals is obscure. we investigated this issue in a mouse model for flavivirus encephalitis in which the virus was administered to 6-week-old animals by the intravenous route, analogous to the portal of entry in natural infections, using a virus dose in the range experienced following the bite of an infectious mosquito. in this model, infection wi ... | 2002 | 11884544 |
| immunization with heterologous flaviviruses protective against fatal west nile encephalitis. | prior immunization of hamsters with three heterologous flaviviruses (japanese encephalitis virus [jev] sa14-2-8 vaccine, wild-type st. louis encephalitis virus [slev], and yellow fever virus [yfv] 17d vaccine) reduces the severity of subsequent west nile virus (wnv) infection. groups of adult hamsters were immunized with each of the heterologous flaviviruses; approximately 30 days later, the animals were injected intraperitoneally with a virulent new york strain of wnv. subsequent levels of vire ... | 2002 | 11927020 |
| development and evaluation of a species diagnostic polymerase chain reaction-restriction fragment-length polymorphism procedure for cryptic members of the culex sitiens (diptera: culicidae) subgroup in australia and the southwest pacific. | members of the culex sitiens subgroup are important vectors of arboviruses, including japanese encephalitis virus, murray valley encephalitis virus and ross river virus. of the eight described species, cx. annulirostris skuse, cx. sitiens wiedemann, and cx. palpalis taylor appear to be the most abundant and widespread throughout northern australia and papua new guinea (png). recent investigations using allozymes have shown this subgroup to contain cryptic species that possess overlapping adult m ... | 2002 | 11931037 |
| reappearance of human cases due to murray valley encephalitis virus and kunjin virus in central australia after an absence of 26 years. | murray valley encephalitis (mve) and kunjin virus disease are endemic in the tropical parts of the northern territory and western australia, but have been absent from central australia since 1974. in 2000, 5 laboratory-confirmed cases of encephalitis occurred over a short period in the normally dry inland region of central australia. the sudden occurrence of cases in march and april 2000 followed unusually high rainfall in the preceding months and evidence of flavivirus activity in the endemic a ... | 2002 | 11950201 |
| mechanism of virulence attenuation of glycosaminoglycan-binding variants of japanese encephalitis virus and murray valley encephalitis virus. | the in vivo mechanism for virulence attenuation of laboratory-derived variants of two flaviviruses in the japanese encephalitis virus (jev) serocomplex is described. host cell adaptation of jev and murray valley encephalitis virus (mve) by serial passage in adenocarcinoma cells selected for variants characterized by (i) a small plaque phenotype, (ii) increased affinity to heparin-sepharose, (iii) enhanced susceptibility to inhibition of infectivity by heparin, and (iv) loss of neuroinvasiveness ... | 2002 | 11967307 |
| introduction of west nile virus in the middle east by migrating white storks. | west nile virus (wnv) was isolated in a flock of 1,200 migrating white storks that landed in eilat, a town in southern israel, on august 26, 1998. strong, hot westerly winds had forced the storks to fly under considerable physical stress before reaching the agricultural land surrounding the town. most of the flock were fledglings, <1 year old, which had hatched in europe. thirteen dead or dying storks were collected 2 days after arrival and submitted to the laboratory for examination. four wnv i ... | 2002 | 11971773 |
| phylogenetic analysis of a human isolate from the 2000 israel west nile virus epidemic. | specimens from a patient of the 2000 israel west nile virus epidemic were analyzed by reverse transcription-polymerase chain reaction. products corresponding to e, ns3, and ns5 sequences were amplified from cerebellar but not from cortical samples. phylogenetic analyses indicated a closer relationship of this isolate to 1996 romanian and 1999 russian than to 1998-99 israeli or 1999 new york isolates. | 2002 | 11996693 |
| infectious cdna clone of the epidemic west nile virus from new york city. | we report the first full-length infectious clone of the current epidemic, lineage i, strain of west nile virus (wnv). the full-length cdna was constructed from reverse transcription-pcr products of viral rna from an isolate collected during the year 2000 outbreak in new york city. it was cloned into plasmid pbr322 under the control of a t7 promoter and stably amplified in escherichia coli hb101. rna transcribed from the full-length cdna clone was highly infectious upon transfection into bhk-21 c ... | 2002 | 12021317 |
| detection of west nile virus antigen in mosquitoes and avian tissues by a monoclonal antibody-based capture enzyme immunoassay. | an antigen capture immunoassay to detect west nile (wn) virus antigen in infected mosquitoes and avian tissues has been developed. with this assay purified wn virus was detected at a concentration of 32 pg/0.1 ml, and antigen in infected suckling mouse brain and laboratory-infected mosquito pools could be detected when the wn virus titer was 10(2.1) to 10(3.7) pfu/0.1 ml. in a blindly coded set of field-collected mosquito pools (n = 100), this assay detected wn virus antigen in 12 of 18 (66.7%) ... | 2002 | 12037058 |
| positional cloning of the murine flavivirus resistance gene. | inbred mouse strains exhibit significant differences in their susceptibility to viruses in the genus flavivirus, which includes human pathogens such as yellow fever, dengue, and west nile virus. a single gene, designated flv, confers this differential susceptibility and was mapped previously to a region of mouse chromosome 5. a positional cloning strategy was used to identify 22 genes from the flv gene interval including 10 members of the 2'-5'-oligoadenylate synthetase gene family. one 2'-5'-ol ... | 2002 | 12080145 |
| the japanese encephalitis serological group of flaviviruses: a brief introduction to the group. | | 2002 | 12082984 |
| emerging viral infections in australia. | hendra virus infection should be suspected in someone with close association with horses or bats who presents acutely with pneumonia or encephalitis (potentially after a prolonged incubation period). australian bat lyssavirus infection should be suspected in a patient with a progressive neurological illness and a history of exposure to a bat. rabies vaccine and immunoglobulin should be strongly considered after a bite, scratch or mucous membrane exposure to a bat. japanese encephalitis vaccine s ... | 2002 | 12088481 |
| emergence of usutu virus, an african mosquito-borne flavivirus of the japanese encephalitis virus group, central europe. | during late summer 2001 in austria, a series of deaths in several species of birds occurred, similar to the beginning of the west nile virus (wnv) epidemic in the united states. we necropsied the dead birds and examined them by various methods; pathologic and immunohistologic investigations suggested a wnv infection. subsequently, the virus was isolated, identified, partially sequenced, and subjected to phylogenetic analysis. the isolates exhibited 97% identity to usutu virus (usuv), a mosquito- ... | 2002 | 12095429 |
| murray valley encephalitis virus recombinant subviral particles protect mice from lethal challenge with virulent wild-type virus. | we report on the development and characterisation of a recombinant murray valley encephalitis virus (mve) envelope glycoprotein expression system that results in the secretion of subviral particles (svps) upon transfection of the murine fibroblast (cos-7) cell line. initially, aspects of the physical and antigenic structure of cell-associated and secreted forms of the mve envelope glycoproteins (prm and e) are presented. we then show that balb/c mice inoculated with svps purified from pcdna(3)-p ... | 2002 | 12111426 |
| isolation of arboviruses from mosquitoes (diptera: culicidae) collected from the gulf plains region of northwest queensland, australia. | as part of investigations into japanese encephalitis (je) virus and related flaviviruses in northern australia, 153,529 mosquitoes were collected and processed for virus isolation from the gulf plains region of northwest queensland. collections from within 30 km of each of the townships of croydon, normanton and karumba yielded 3,087 (2.0%), 66,009 (43.0%), and 84,433 (55.0%) mosquitoes, respectively, from which 16 viruses were isolated. four isolates of murray valley encephalitis (mve), two of ... | 2002 | 12349863 |
| epizootic activity of murray valley encephalitis virus in an aboriginal community in the southeast kimberley region of western australia: results of cross-sectional and longitudinal serologic studies. | murray valley encephalitis (mve) virus is a mosquito-borne flavivirus causing severe encephalitis with a resultant high morbidity and mortality. in the period 1989-1993, we undertook a cross-sectional and longitudinal study by annually screening members of a small remote aboriginal community in northwestern australia for mve virus antibodies. of the estimated 250-300 people in the community, 249 were tested, and 52.6% had positive serology to mve. the proportion testing positive increased with i ... | 2002 | 12408675 |
| sentinel chicken surveillance programme in australia, 1 july 2001 to 30 june 2002. | detection of flavivirus seroconversions in sentinel chicken flocks located throughout australia is used to provide an early warning of increased levels of murray valley encephalitis (mve) and kunjin virus activity in the region. during the 2001/2002 season low levels of flavivirus activity were detected in northern australia compared to previous years. mve and kunjin virus activity was detected in the kimberley and pilbara regions of western australia and the northern territory but not in north ... | 2002 | 12416705 |
| researchers as guinea pigs. | | 2003 | 12526720 |
| interferons, interferon inducers, and interferon-ribavirin in treatment of flavivirus-induced encephalitis in mice. | we evaluated the prophylactic and therapeutic efficacy of interferon alpha-2b, pegylated interferon alpha-2b, poly(i. c), and ampligen against modoc virus encephalitis in an animal model for flavivirus infections. all compounds significantly delayed virus-induced morbidity (paralysis) and mortality (due to progressive encephalitis). viral load (as measured on day 7 postinfection) was significantly reduced by 80 to 100% in the serum, brain, and spleen in mice that had been treated with either int ... | 2003 | 12543691 |
| b cells and antibody play critical roles in the immediate defense of disseminated infection by west nile encephalitis virus. | west nile virus (wnv) causes severe central nervous system (cns) infection primarily in humans who are immunocompromised or elderly. in this study, we addressed the mechanism by which the immune system limits dissemination of wnv infection by infecting wild-type and immunodeficient inbred c57bl/6j mice with a low-passage wnv isolate from the recent epidemic in new york state. wild-type mice replicated virus extraneuronally in the draining lymph nodes and spleen during the first 4 days of infecti ... | 2003 | 12551996 |
| murray valley encephalitis: case report and review of neuroradiological features. | we report on a child with diffuse symmetrical thalamic enlargement and signal increase on mri, representing changes caused by murray valley encephalitis (mve). very little has previously been reported on the neuroradiological findings of mve, also known as australian encephalitis. it is endemic to tropical north australia, particularly western australia and the northern territory, but can occur in other parts of australia. the last epidemic was in south-eastern australia in 1974. australian ence ... | 2003 | 12581057 |
| origin and evolution of japanese encephalitis virus in southeast asia. | since it emerged in japan in the 1870s, japanese encephalitis has spread across asia and has become the most important cause of epidemic encephalitis worldwide. four genotypes of japanese encephalitis virus (jev) are presently recognized (representatives of genotypes i to iii have been fully sequenced), but its origin is not known. we have determined the complete nucleotide and amino acid sequence of a genotype iv indonesian isolate (jkt6468) which represents the oldest lineage, compared it with ... | 2003 | 12584335 |
| role of type i and type ii interferon responses in recovery from infection with an encephalitic flavivirus. | we have investigated the contribution of the interferon (ifn)-alpha/beta system, ifn-gamma and nitric oxide to recovery from infection with murray valley encephalitis virus, using a mouse model for flaviviral encephalitis where a small dose of virus was administered to 6-week-old wild-type and gene knockout animals by the intravenous route. we show that a defect in the ifn-alpha/beta responses results in uncontrolled extraneural virus growth, rapid virus entry into the brain and 100 % mortality. ... | 2003 | 12604807 |
| a japanese encephalitis virus peptide present on johnson grass mosaic virus-like particles induces virus-neutralizing antibodies and protects mice against lethal challenge. | protection against japanese encephalitis virus (jev) is antibody dependent, and neutralizing antibodies alone are sufficient to impart protection. thus, we are aiming to develop a peptide-based vaccine against jev by identifying jev peptide sequences that could induce virus-neutralizing antibodies. previously, we have synthesized large amounts of johnson grass mosaic virus (jgmv) coat protein (cp) in escherichia coli and have shown that it autoassembled to form virus-like particles (vlps). the e ... | 2003 | 12610124 |
| epitope-blocking enzyme-linked immunosorbent assays for the detection of serum antibodies to west nile virus in multiple avian species. | we report the development of epitope-blocking enzyme-linked immunosorbent assays (elisas) for the rapid detection of serum antibodies to west nile virus (wnv) in taxonomically diverse north american avian species. a panel of flavivirus-specific monoclonal antibodies (mabs) was tested in blocking assays with serum samples from wnv-infected chickens and crows. selected mabs were further tested against serum samples from birds that represented 16 species and 10 families. serum samples were collecte ... | 2003 | 12624027 |
| cross-protective and infection-enhancing immunity in mice vaccinated against flaviviruses belonging to the japanese encephalitis virus serocomplex. | the japanese encephalitis virus serocomplex is a group of mosquito-borne flaviviruses that cause severe encephalitic disease in humans. the recent emergence of several members of this serocomplex in geographic regions where other closely related flaviviruses are endemic has raised urgent human health issues. thus, the impact of vaccination against one of these neurotropic virus on the outcome of infection with a second, serologically related virus is unknown. we show here that immunity against m ... | 2003 | 12639478 |
| persistence of virus-reactive serum immunoglobulin m antibody in confirmed west nile virus encephalitis cases. | twenty-nine laboratory-confirmed west nile virus (wnv encephalitis patients were bled serially so that wnv-reactive immunoglobulin (ig) m activity could be determined. of those patients bled, 7 (60%) of 12 had anti-wnv igm at approximately 500 days after onset. clinicians should be cautious when interpreting serologic results from early season wnv igm-positive patients. | 2003 | 12643836 |
| investigation of the southern limits of murray valley encephalitis activity in western australia during the 2000 wet season. | western australia experienced its worst-ever outbreak of the mosquito-borne murray valley encephalitis (mve) virus during the 2000 wet season. highest-on-record rainfall throughout much of the state during the 2000 wet season gave rise to extensive mosquito breeding and increased mve virus transmission, resulting in nine cases of encephalitis. activity of mve virus in western australia is monitored by detecting mve virus-specific antibodies in serum from sentinel chickens, located at towns and c ... | 2002 | 12653302 |
| west nile encephalitis. | | 2003 | 12702624 |
| australia's notifiable diseases status, 2001: annual report of the national notifiable diseases surveillance system. | in 2001 there were 104,187 notifications of communicable diseases in australia reported to the national notifiable diseases surveillance system (nndss). the number of notifications in 2001 was an increase of 16 per cent of those reported in 2000 (89,740) and the largest annual total since the nndss commenced in 1991. in 2001, nine new diseases were added to the list of diseases reported to nndss and four diseases were removed. the new diseases were cryptosporidiosis, laboratory-confirmed influen ... | 2003 | 12725505 |
| rainfall and vector mosquito numbers as risk indicators for mosquito-borne disease in central australia. | there have been 5 confirmed cases of murray valley encephalitis virus (mve) infection in the alice springs region during the high rainfall years of 1999/00 and 2000/01, compared with one case in the preceding 9 years. there also appeared to be an increased prevalence of ross river virus (rr) infection in the alice springs and tennant creek regions associated with high rainfall. this paper presents an analysis of summer rainfall from 1990/91 to 2000/01, numbers of seroconversion of sentinel chick ... | 2003 | 12725512 |
| flavivirus capsid is a dimeric alpha-helical protein. | the capsid proteins of two flaviviruses, yellow fever virus and dengue virus, were expressed in escherichia coli and purified to near homogeneity suitable for biochemical characterization and structure determination by nuclear magnetic resonance. the oligomeric properties of the capsid protein in solution were investigated. in the absence of nucleic acid, both proteins were predominantly dimeric in solution. further analysis of both proteins with far-uv circular dichroism spectroscopy indicated ... | 2003 | 12768036 |
| epitope-blocking enzyme-linked immunosorbent assays for detection of west nile virus antibodies in domestic mammals. | we evaluated the ability of epitope-blocking enzyme-linked immunosorbent assays (elisas) to detect west nile virus (wnv) antibodies in domestic mammals. sera were collected from experimentally infected horses, cats, and pigs at regular intervals and screened in elisas and plaque reduction neutralization tests. the diagnostic efficacies of these techniques were similar. | 2003 | 12791902 |
| antibody-dependent enhancement of murray valley encephalitis virus virulence in mice. | enhancement of flavivirus infection in vitro in the presence of subneutralizing concentrations of homologous or heterologous antiserum has been well described. however, the importance of this phenomenon in the enhancement of flavivirus infection in vivo has not been established. in order to study antibody-mediated enhancement of flavivirus infection in vivo, we investigated the effect of passive immunization of mice with japanese encephalitis virus (je) antiserum on the outcome of infection with ... | 2003 | 12810865 |
| molecular and functional analyses of kunjin virus infectious cdna clones demonstrate the essential roles for ns2a in virus assembly and for a nonconservative residue in ns3 in rna replication. | a number of full-length cdna clones of kunjin virus (kun) were previously prepared; it was shown that two of them, pakun and flsdx, differed in specific infectivities of corresponding in vitro transcribed rnas by approximately 100,000-fold (a. a. khromykh et al., j. virol. 72:7270-7279, 1998). in this study, we analyzed a possible genetic determinant(s) of the observed differences in infectivity initially by sequencing the entire cdnas of both clones and comparing them with the published sequenc ... | 2003 | 12829820 |
| west nile virus encephalomyelitis in horses in ontario: 28 cases. | west nile virus encephalomyelitis was diagnosed in 28 horses presented to the ontario veterinary college veterinary teaching hospital between august 20 and october 15, 2002. the age range of affected horses was 5 months to 20 years (mean 6.9 years, median 6 years). clinical signs were highly variable. duration of hospitalization ranged from < 1 to 12 days (mean 5 days, median 5.4 days). overall, 16 of the 28 (57%) horses were discharged and, of the 14 from which follow-up information was availab ... | 2003 | 12839240 |
| clinical and laboratory findings on the first imported case of murray valley encephalitis in europe. | murray valley encephalitis (mve) is an important mosquitoborne flavivirus infection endemic to australia and papua new guinea. we report the first imported case of mve in europe. a 23-year-old tourist developed severe encephalitis after having returned to germany from a long-term trip across the australian continent. the diagnosis was suspected on the basis of clinical findings and the patient's travel history and was confirmed by serological findings. the patient made a prolonged but complete r ... | 2003 | 12856229 |
| serologic evidence of west nile virus infection in horses, coahuila state, mexico. | serum samples were obtained from 24 horses in the state of coahuila, mexico, in december 2002. antibodies to west nile virus were detected by epitope-blocking enzyme-linked immunosorbent assay and confirmed by plaque reduction neutralization test in 15 (62.5%) horses. we report the first west nile virus activity in northern mexico. | 2003 | 12890327 |
| mr findings in murray valley encephalitis. | murray valley encephalitis (mve) is caused by a flavivirus related to west nile and st. louis encephalitis viruses. we report a case of mve resulting in quadriplegia and respiratory failure. mr imaging demonstrated thalamic hyperintensity on t2-weighted images, with similar involvement of the red nucleus, substantia nigra, and cervical cord. these findings preceded serologic diagnosis and are similar to those of japanese encephalitis. in the appropriate setting, thalamic t2 hyperintensity is sug ... | 2003 | 12917132 |
| dna vaccine coding for the full-length infectious kunjin virus rna protects mice against the new york strain of west nile virus. | a plasmid dna directing transcription of the infectious full-length rna genome of kunjin (kun) virus in vivo from a mammalian expression promoter was used to vaccinate mice intramuscularly. the kun viral cdna encoded in the plasmid contained the mutation in the ns1 protein (pro-250 to leu) previously shown to attenuate kun virus in weanling mice. kun virus was isolated from the blood of immunized mice 3-4 days after dna inoculation, demonstrating that infectious rna was being transcribed in vivo ... | 2003 | 12917491 |
| functional analysis of mosquito-borne flavivirus conserved sequence elements within 3' untranslated region of west nile virus by use of a reporting replicon that differentiates between viral translation and rna replication. | we have developed a reporting replicon of west nile virus (wnv) that could be used to quantitatively distinguish viral translation and rna replication. a renilla luciferase (rluc) gene was fused in-frame with the open reading frame of a subgenomic replicon in the position where the viral structural region was deleted, resulting in rlucrep. transfection of bhk cells with rlucrep rna yielded two distinctive rluc signal peaks, one between 2 and 10 h and the other after 26 h posttransfection. by con ... | 2003 | 12941911 |
| t cells cause acute immunopathology and are required for long-term survival in mouse adenovirus type 1-induced encephalomyelitis. | infection of adult c57bl/6 (b6) mice with mouse adenovirus type 1 (mav-1) results in dose-dependent encephalomyelitis. utilizing immunodeficient mice, we analyzed the roles of t cells, t-cell subsets, and t-cell-related functions in mav-1-induced encephalomyelitis. t cells, major histocompatibility complex (mhc) class i, and perforin contributed to acute disease signs at 8 days postinfection (p.i.). acute mav-1-induced encephalomyelitis was absent in mice lacking t cells and in mice lacking perf ... | 2003 | 12941916 |
| identification of the receptor binding domain of the mouse mammary tumor virus envelope protein. | mouse mammary tumor virus (mmtv) is a betaretrovirus that infects rodent cells and uses mouse transferrin receptor 1 for cell entry. to characterize the interaction of mmtv with its receptor, we aligned the mmtv envelope surface (su) protein with that of friend murine leukemia virus (f-mlv) and identified a putative receptor-binding domain (rbd) that included a receptor binding sequence (rbs) of five amino acids and a heparin-binding domain (hbd). mutation of the hbd reduced virus infectivity, a ... | 2003 | 12970432 |
| transmission of murray valley encephalitis virus by mosquitoes. | | 1953 | 13115309 |
| the behaviour of murray valley encephalitis virus in young chickens. | | 1953 | 13115310 |
| the absence of murray valley encephalitis virus from the murray valley, 1952-1953. | | 1954 | 13132162 |
| murray valley encephalitis virus: its serological relationship to the japanese-west nile-st. louis encephalitis group of viruses. | | 1955 | 13242806 |
| serological group reactions of murray valley encephalitis virus. | | 1956 | 13328731 |
| murray valley encephalitis in new guinea. i. isolation of murray valley encephalitis virus from the brain of a fatal case of encephalitis occurring in a papuan native. | | 1957 | 13470202 |
| yield of infective ribonucleic acid from impure murray valley encephalitis virus after different treatments. | | 1959 | 13644196 |
| maze performance of mature rats recovered from early postnatal infection with murray valley encephalitis virus. | | 1959 | 13654571 |
| purification of murray valley encephalitis virus. | | 1961 | 13681287 |
| a lipid component of murray valley encephalitis virus. | | 1960 | 13683280 |
| the action of phospholipase a and lipid solvents on murray valley encephalitis virus. | | 1961 | 13683281 |
| murray valley encephalitis virus: preparation of an infective "ribonucleic acid" fraction. | | 1959 | 13793450 |
| particle counts and some chemical properties of murray valley encephalitis virus. | | 1962 | 13859227 |
| a plaque assay method for murray valley encephalitis virus. | | 1963 | 13965581 |
| the behavior of murray valley encephalitis virus in culex tritaeniorhynchus giles and culex pipiens quinquefasciatus say. | | 1963 | 14044755 |
| ethics committees and guardianship legislation. | | 2003 | 14503909 |