Publications

biological consequences of deletions within the 3'-untranslated region of flaviviruses may be due to rearrangements of rna secondary structure.	it was previously reported that deletions introduced into the 3'-untranslated region (3'-utr) of dengue type 4 (den 4) virus (men, r., bray, m., clark, d., chanock, r.m., lai, c.j., 1996. den 4 virus mutants containing deletions in the 3'-noncoding region of the rna genome: analysis of growth restriction in cell culture and altered viremia pattern and immunogenicity in rhesus monkeys. j. virol. 70, 3930-3937), tick-borne encephalitis (tbe) virus (mandl, c.w., holzmann, h., meixner, t., rauscher, ...	1999	10518708
identification of a kunjin/west nile-like flavivirus in brains of patients with new york encephalitis.	molecular analysis of brains from patients of the recent new york city encephalitis outbreak reveals the presence of a flavivirus not previously described in the americas.	1999	10520637
electron microscopic diagnosis of human flavivirus encephalitis: use of confocal microscopy as an aid.	the distinction between intracranial viral infections and inflammatory conditions requiring immunosuppression is important. although specific laboratory reagents are readily available for some viruses, diagnosis of arbovirus infection is more difficult. transmission electron microscopy (tem) theoretically allows identification of viral particles independent of reagent availability, but it has limited sensitivity. we report two cases of human flavivirus encephalitis diagnosed by tem. laser scanni ...	1999	10524522
loss of dimerisation of the nonstructural protein ns1 of kunjin virus delays viral replication and reduces virulence in mice, but still allows secretion of ns1.	the flavivirus nonstructural protein ns1 has been implicated in viral rna replication, although its precise role has not been identified. in its native state ns1 exists as a heat labile homodimer that is thought to be required for ns1 function and secretion. however, we have recently identified a cdna clone of kun virus (flsd) that replicates efficiently in cell culture but produces and secretes ns1 in monomeric form. sequence analysis of the ns1 gene in flsd revealed a single amino acid substit ...	1999	10544130
mutational analysis of bovine viral diarrhea virus rna-dependent rna polymerase.	recombinant bovine viral diarrhea virus (bvdv) nonstructural protein 5b (ns5b) produced in insect cells has been shown to possess an rna-dependent rna polymerase (rdrp) activity. our initial attempt to produce the full-length bvdv ns5b with a c-terminal hexahistidine tag in escherichia coli failed due to the expression of insoluble products. prompted by a recent report that removal of the c-terminal hydrophobic domain significantly improved the solubility of hepatitis c virus (hcv) ns5b, we cons ...	1999	10559328
screening of protective antigens of japanese encephalitis virus by dna immunization: a comparative study with conventional viral vaccines.	in this study, we evaluated the relative role of the structural and nonstructural proteins of the japanese encephalitis virus (jev) in inducing protective immunities and compared the results with those induced by the inactivated jev vaccine. several inbred and outbred mouse strains immunized with a plasmid (pe) encoding the jev envelope protein elicited a high level of protection against a lethal jev challenge similar to that achieved by the inactivated vaccine, whereas all the other genes teste ...	1999	10559329
efficient trans-complementation of the flavivirus kunjin ns5 protein but not of the ns1 protein requires its coexpression with other components of the viral replicase.	successful trans-complementation of the defective kunjin virus (kun) rna fldgdd with a deletion of the rna polymerase motif gdd in the ns5 gene by using a bhk cell line, repbhk, that continuously produced a functionally active kun replication complex (rc) from replicon rna was recently reported (a. a. khromykh, m. t. kenney, and e. g. westaway, j. virol. 72:7270-7279, 1998). in order to identify whether this complementation of fldgdd rna was provided by the wild-type ns5 protein alone or with th ...	1999	10559344
prevalence of gbv-c/hgv-rna, virus genotypes, and anti-e2 antibodies in autoimmune hepatitis.	we investigated the prevalence of hepatitis g-rna (gbv-c/hgv-rna), a recently cloned new flavivirus, and of antibodies to the envelope 2 antigen (anti-e2), a marker of past infection, in patients with autoimmune hepatitis, and compared it with the prevalence in patients with chronic viral hepatitis and healthy control individuals.	1999	10566740
characterization of infectious murray valley encephalitis virus derived from a stably cloned genome-length cdna.	an infectious cdna clone of murray valley encephalitis virus prototype strain 1-51 (mve-1-51) was constructed by stably inserting genome-length cdna into the low-copy-number plasmid vector pmc18. designated pmve-1-51, the clone consisted of genome-length cdna of mve-1-51 under the control of a t7 rna polymerase promoter. the clone was constructed by using existing components of a cdna library, in addition to cdna of the 3' terminus derived by rt-pcr of poly(a)-tailed viral rna. upon comparison w ...	1999	10567642
phylogenetic and virulence analysis of tick-borne encephalitis viruses from japan and far-eastern russia.	we have previously reported that tick-borne encephalitis (tbe) is endemic in a specific area of hokkaido, japan. in oshima, the southern part of hokkaido, tbe virus was isolated from sentinel dogs, ticks and rodents in 1995 and 1996. to identify when these tbe viruses emerged in hokkaido, the times of divergence of tbe virus strains isolated in oshima and far-eastern russia were estimated. tbe virus was isolated in khabarovsk in 1998 and the nucleotide sequences of viral envelope protein genes o ...	1999	10567643
the rna-dependent rna polymerases of different members of the family flaviviridae exhibit similar properties in vitro.	the virus-encoded rna-dependent rna polymerase (rdrp), which is required for replication of the positive-strand rna genome, is a key enzyme of members of the virus family flaviviridae. by using heterologously expressed proteins, we demonstrate that the 77 kda ns5b protein of two pestiviruses, bovine viral diarrhoea virus and classical swine fever virus, and the 100 kda ns5 protein of the west nile flavivirus possess rdrp activity in vitro. as originally shown for the rdrp of hepatitis c virus, r ...	1999	10573150
the design and synthesis of potent inhibitors of hepatitis c virus ns3-4a proteinase.	hepatitis c virus (hcv) is the cause of the majority of transfusion-associated hepatitis and a significant proportion of community-acquired hepatitis worldwide. infection by hcv frequently leads to persistent infections that result in a range of clinical conditions including an asymptomatic carrier state, severe chronic active hepatitis, cirrhosis and, in some cases, hepatocellular carcinoma. the hcv genome consists of a single-stranded, positive sense rna containing an open reading frame of app ...	1999	10574181
a dna immunization model study with constructs expressing the tick-borne encephalitis virus envelope protein e in different physical forms.	we have conducted a dna immunization study to evaluate how the immune response is influenced by the physical structure and secretion of the expressed ag. for this purpose, we used a series of plasmid constructs encoding different forms of the envelope glycoprotein e of the flavivirus tick-borne encephalitis virus. these included a secreted recombinant subviral particle, a secreted carboxyl-terminally truncated soluble homodimer, a nonsecreted full-length form, and an inefficiently secreted trunc ...	1999	10586074
prevalence of gbv c/hgv rna and gbv c/hgv antibodies in french volunteer blood donors: results of a collaborative study.	posttransfusion hepatitis still occurs at an incidence of about 1 in 118,000 for hbv and 1 in 220,000 for hcv. this collaborative study aimed to determine the prevalence of a novel flavivirus, gbv-c/hgv, even though its role in transfusion-associated hepatitis is uncertain.	1999	10341332
rapid serologic diagnosis of dengue virus infection using a commercial capture elisa that distinguishes primary and secondary infections.	a commercial capture elisa for specific igm and igg antibodies produced during dengue infection (panbio dengue duo) showed excellent sensitivity (99%, n = 78) using sera collected at hospital discharge compared with established elisa and hemagglutination inhibition (hai) assays. furthermore, the elisa was able to diagnose 79% of the dengue cases using sera collected at hospital admission. the elisa also showed high specificity (92%) in paired sera from patients without flavivirus infection (n = ...	1999	10348250
homology model of the dengue 2 virus ns3 protease: putative interactions with both substrate and ns2b cofactor.	the crystal structure coordinates of the hepatitis c virus ns3 protease (hcvpro) were used to develop an homology model of the dengue 2 virus ns3 protease (den2pro). the amino acid sequence of den2pro accommodates the same alpha-helices, beta-sheets and protein-binding domains as its hcvpro counterpart, but the model predicts a number of significant differences for den2pro and its interactions with substrates and cofactor. whereas hcvpro contains a zn2+-binding site, there is no equivalent metal ...	1999	10355763
recombinant semliki forest virus particles encoding the prme or ns1 proteins of louping ill virus protect mice from lethal challenge.	recombinant semliki forest virus (rsfv) vaccines encoding louping ill virus (liv) genes prme and ns1 were examined. cells transfected with rsfv-prme rna showed correct processing of the precursor prme and the release into the medium of m and e proteins in particulate form, whilst rsfv-ns1-transfected cells secreted glycosylated, heat-labile ns1 dimers. mice immunized with rsfv particles produced antibodies against prme and ns1 that were mainly of the igg2a subtype, indicating that a t-helper 1 i ...	1999	10355766
mutation patterns for two flaviviruses: hepatitis c virus and gb virus c/hepatitis g virus.	we studied the mutation patterns of hepatitis c virus (hcv) and gb virus c/hepatitis g virus (hgv). although the mutation patterns of the two viruses were similar to each other, they were quite different from that of hiv. in particular, the similarity of the patterns between hcv or hgv and human nuclear pseudogenes was statistically significant whereas there was no similarity between hiv and human nuclear pseudogenes. this finding suggests that the mutation patterns of hcv and hgv are similar to ...	1999	10359092
the anamnestic neutralizing antibody response is critical for protection of mice from challenge following vaccination with a plasmid encoding the japanese encephalitis virus premembrane and envelope genes.	for japanese encephalitis (je), we previously reported that recombinant vaccine-induced protection from disease does not prevent challenge virus replication in mice. moreover, dna vaccines for je can provide protection from high challenge doses in the absence of detectable prechallenge neutralizing antibodies. in the present study, we evaluated the role of postchallenge immune responses in determining the outcome of je virus infection, using mice immunized with a plasmid, pcdna3jeme, encoding th ...	1999	10364301
mapping of functional elements in the stem-anchor region of tick-borne encephalitis virus envelope protein e.	envelope protein e of the flavivirus tick-borne encephalitis virus mediates membrane fusion, and the structure of the n-terminal 80% of this 496-amino-acid-long protein has been shown to differ significantly from that of other viral fusion proteins. the structure of the carboxy-terminal 20%, the stem-anchor region, is not known. it contains sequences that are important for membrane anchoring, interactions with prm (the precursor of membrane protein m) during virion assembly, and low-ph-induced s ...	1999	10364309
molecular evidence of mother-to-infant transmission of hepatitis g virus among women without known risk factors for parenteral infections.	hepatitis g virus (hgv) rna was detected in 18 of 133 pregnant women from tanzania without known risk factors for hgv infection and in 7 of 18 children born to hgv rna-positive mothers. molecular evidence of mother-to-infant transmission was obtained only for three of seven children. hgv rna was also detected in 4 of 42 children born to non-hgv-infected women. thus, mechanisms other than materno-filial may play an important role in hgv transmission during early childhood.	1999	10364608
degradation of japanese encephalitis virus by neutrophils.	the ability of neutrophils to degrade the phagocytosed japanese encephalitis (je) virion, via triggering of the respiratory burst and generation of toxic radicals has been investigated. jev or jev-induced macrophage derived factor (mdf) induces increase in intracellular oxidative signals with generation of superoxide anion (o2-), via activation of cytosolic nadph and subsequent formation of hydrogen peroxide, with maximum activity on day 7 post infection. the response was sensitive to anti-mdf a ...	1999	10365083
partial nucleotide sequencing of the ns3/helicase region of hepatitis g virus to prove vertical transmission.	to study non-parental transmission of hepatitis g virus and/or gb virus c (hgv/gbv-c), we sequenced and compared the ns3/helicase region of the virus for five hgv/gbv-c rna-positive mothers and their 11 children who had experienced neither blood transfusion nor overt hepatitis and were negative for hbv, hcv and hiv, except in one mother coinfected with hcv. the nucleotide sequences of the familial hgv/gbv-c isolates showed high similarity of 99-100% (mean 99.8%, 100% at the deduced amino acid le ...	1999	10386379
crystallization, characterization and measurement of mad data on crystals of dengue virus ns3 serine protease complexed with mung-bean bowman-birk inhibitor.	crystallization and preliminary characterization of the essential dengue virus ns3 serine protease complexed with a bowman-birk-type inhibitor from mung beans are reported. as the structure proved resistant to solution by molecular replacement and multiple isomorphous replacement methods, multi-wavelength anomalous diffraction data at the liii edge of a holmium derivative have been measured. promising bijvoet and dispersive signals which are largely consistent with expected values have been extr ...	1999	10393310
membrane permeabilization by small hydrophobic nonstructural proteins of japanese encephalitis virus.	infection with japanese encephalitis virus (jev), a mosquito-borne flavivirus, may cause acute encephalitis in humans and induce severe cytopathic effects in various types of cultured cells. we observed that jev replication rendered infected baby hamster kidney (bhk-21) cells sensitive to the translational inhibitor hygromycin b or alpha-sarcine, to which mock-infected cells were insensitive. however, little is known about whether any jev nonstructural (ns) proteins contribute to virus-induced c ...	1999	10400716
functional analysis of cell surface-expressed hepatitis c virus e2 glycoprotein.	hepatitis c virus (hcv) glycoproteins e1 and e2, when expressed in eukaryotic cells, are retained in the endoplasmic reticulum (er). c-terminal truncation of e2 at residue 661 or 715 (position on the polyprotein) leads to secretion, consistent with deletion of a proposed hydrophobic transmembrane anchor sequence. we demonstrate cell surface expression of a chimeric glycoprotein consisting of e2 residues 384 to 661 fused to the transmembrane and cytoplasmic domains of influenza a virus hemaggluti ...	1999	10400776
a monoclonal antibody that recognizes the predicted tick-borne encephalitis virus e protein fusion sequence blocks fusion.	the fusion motif of tick-borne encephalitis virus e protein has been predicted to be located within its conserved region (98-120). results are presented to demonstrate that non-neutralizing monoclonal antibody which recognizes a synthetic peptide corresponding to residues 98-113 of the e protein sequence can block the fusion of the virus particles with artificial membranes.	1999	10416385
communicable diseases surveillance. you left an error in the record.		1999	10432763
mosquito-borne viruses in western europe: a review.	several mosquito-borne arboviruses belonging to the genera alphavirus, flavivirus, and bunyavirus have been reported to occur in mosquitoes and to infect humans and other vertebrates in western europe. these zoonotic viruses circulate in nature either in an aedes-mammal, anopheles-mammal, or culex-bird transmission cycle. infected humans normally do not contribute to the virus circulation. west nile virus (flavivirus) caused an outbreak of fever, malaise, pain in eyes and muscles, and headache a ...	1999	10436876
genetic analysis of west nile new york 1999 encephalitis virus.	analysis of the genome of the flavivirus responsible for the 1999 new york city encephalitis epidemic cloned from human brain by reverse-transcription polymerase chain reaction indicates its identity as a lineage i west nile virus (wnv; wnv-ny1999) closely related to wnvs previously isolated in the middle east.	1999	10622305
viral heterogeneity of the hepatitis c virus.	this review summarises the classification of hepatitis c virus as a flavivirus, the identification and detection of hcv genotypes, and reviews the current information concerning the geographical and risk group associations of the common genotypes in europe.	1999	10622561
mutant influenza viruses with a defective ns1 protein cannot block the activation of pkr in infected cells.	a short model genome rna and also the genome rna of influenza a virus bearing both 5'- and 3'-terminal common sequences activated the interferon-induced double-stranded-rna-dependent protein kinase, pkr, by stimulating autophosphorylation in vitro. the activated pkr catalyzed phosphorylation of the alpha subunit of eucaryotic translation initiation factor 2 (eif2alpha). the ns1 protein efficiently eliminated the pkr-activating activity of these rnas by binding to them. two mutant ns1 proteins, e ...	1999	9971827
gb virus c/hepatitis g virus infection in hemodialysis patients: determination of seroprevalence by a four-antigen recombinant immunoblot assay.	gb virus c/hepatitis g virus (gbv-c/hgv) was identified recently and only two assays, consisting of a single recombinant protein, have been described for determination of the seroprevalence of this virus. an immunoblot assay was devised, which contains four recombinant gbv-c/hgv proteins. in this study, serum samples from 154 patients on maintenance hemodialysis were examined to assess the rate of seroreactivity against gbv-c/hgv. all sera were tested for the presence of antibodies by an in-hous ...	1999	10022792
dengue virus ns3 serine protease. crystal structure and insights into interaction of the active site with substrates by molecular modeling and structural analysis of mutational effects.	the mosquito-borne dengue viruses are widespread human pathogens causing dengue fever, dengue hemorrhagic fever, and dengue shock syndrome, placing 40% of the world's population at risk with no effective treatment. the viral genome is a positive strand rna that encodes a single polyprotein precursor. processing of the polyprotein precursor into mature proteins is carried out by the host signal peptidase and by ns3 serine protease, which requires ns2b as a cofactor. we report here the crystal str ...	1999	10026173
isolation of homologous arbovirus cultures from heterologous mixtures using limit dilution and virus-specific enzyme immunoassays.	viral cultures were identified recently that contained both kunjin virus and the closely related flavivirus west nile. the observation that the kun virus population grew more efficiently in a mosquito cell line (c6/36) while the wn population replicated more effectively in mammalian cells (vero) allowed enrichment for either virus by culturing the mixture in the appropriate cell line. limit dilution of the enriched virus preparations was then performed by infecting microtitre cultures with seria ...	1999	10598096
origin of the west nile virus responsible for an outbreak of encephalitis in the northeastern united states.	in late summer 1999, an outbreak of human encephalitis occurred in the northeastern united states that was concurrent with extensive mortality in crows (corvus species) as well as the deaths of several exotic birds at a zoological park in the same area. complete genome sequencing of a flavivirus isolated from the brain of a dead chilean flamingo (phoenicopterus chilensis), together with partial sequence analysis of envelope glycoprotein (e-glycoprotein) genes amplified from several other species ...	1999	10600742
the ns3/4a proteinase of the hepatitis c virus: unravelling structure and function of an unusual enzyme and a prime target for antiviral therapy.	the hepatitis c virus (hcv) is a major causative agent of transfusion-acquired and sporadic non-a, non-b hepatitis worldwide. infections most often persist and lead, in approximately 50% of all patients, to chronic liver disease. as is characteristic for a member of the family flaviviridae, hcv has a plus-strand rna genome encoding a polyprotein, which is cleaved co- and post-translationally into at least 10 different products. these cleavages are mediated, among others, by a virally encoded chy ...	1999	10607229
flaviviridae polymerase and rna replication.	sequence motifs within the non-structural protein ns5 or ns5b of the members of the family flaviviridae suggest that this protein is the rna-dependent rna polymerase. this protein has now been expressed in various in vitro systems and used in polymerase assays. to understand the role of the rna polymerase in rna replication, this review will examine not only the polymerase protein but also the other proteins in the rna replication complex. to date, several groups have investigated the interactio ...	1999	10607240
hepatitis g: viroprevalence and seroconversion in a high-risk group of children.	hepatitis g virus (hgv), a recently discovered flavivirus, is parenterally transmitted and significantly associated with hepatitis c viraemia. data on the viroprevalence of this agent in children is scant and its seroprevalence is unknown. the aim of this study was to determine the viroprevalence and seroprevalence of hgv in paediatric patients at risk of parenterally transmitted virus infection. sera from 35 patients, previously tested for hepatitis c virus (hcv) infection, were analysed for th ...	1999	10607249
evaluation of an igg enzyme-linked immunosorbent assay for dengue diagnosis.	the hemagglutination inhibition (hi) test has been one of the standards, with the igm antibody capture elisa (mac-elisa), for the diagnosis of dengue virus infections. the spread of dengue throughout the world and the increasing number of cases to be tested makes an elisa-format test for igg antibodies to replace the hi test highly desirable.	1999	10614855
variations in lps responsiveness among different mouse substrains of c3h lineage and their congenic derivative sublines.		1999	10630301
tick-borne encephalitis virus ns3 gene expression does not protect mice from homologous viral challenge.	tick-borne encephalitis virus (tbev) ns3 gene has been subcloned into the expression vector pcdnai and expressed in eukaryotic cells. immunization of mice with the recombinant plasmid pcdnai-ns3 induced antibodies against ns3 protein but did not protect from viral challenge.	1999	10630787
[japanese encephalitis virus and other flavivirus].		1999	10635838
discovery of non-a, non-b hepatitis and identification of its etiology.	the discovery of hepatitis c was the direct result of the landmark discoveries of hepatitis b virus (hbv) and hepatitis a virus (hav) and their serologies. screening tests for hav and hbv made it possible in the mid-1970s to examine cases of transfusion-associated hepatitis (tah) and to demonstrate that only approximately 25% resulted from hbv and that none were related to hav. consequently, approximately 75% of tah became classified as non-a, non-b hepatitis (nanbh). subsequently, chimpanzee st ...	1999	10653450
infections with flaviviridae.	the family of the flaviviridae contains 3 genera: (i) the hepaciviruses, to which belongs hepatitis c virus (hcv), (ii) the flaviviruses and (iii) the pestiviruses. over 140 million people, more than four times the number of hiv-positive individuals, are chronically infected with the hcv. hepatitis g virus (hgv) has not yet been assigned to a genus. the impact of this recently discovered virus is yet to be established. infections with flaviviruses such as yellow fever virus (yfv), dengue fever v ...	1999	10655776
identification of a flavivirus isolated from mosquitos in chiang mai thailand.	a virus isolate, thcar105/92, from a pool of mosquitos, culex tritaeniorhynchus, collected in chiang mai, thailand in 1992, appeared to be a member of the genus flavivirus of the family flaviviridae, based on the reverse transcription polymerase chain reaction (rt-pcr) using flavivirus cross-reacting primer pairs, electron microscopic examination, and serological tests. however, rt-pcr using japanese encephalitis (je) virus-specific primers showed that the isolate was different from je virus. su ...	1999	10695806
[a study on the pathogenicity of acute hepatitis g infection].	to study the infection due to hepatitis g virus (hgv) in liver tissues of patients with acute hepatitis and to investigate its pathogenicity.	1999	11798655
[transmission and conservation of the amaril virus in nature].	the yellow fever virus is a monkey flavivirus transmitted by mosquitoes. the transmission cycles and vectors vary from western to eastern africa and in south america. there are two types of endemic areas where the virus is maintained: humid forests and emerging zones and areas where intermediary and urban epidemics occur. on both continents, the virus circulates in forest areas by moving epizooties from one region to another among non immune monkeys. the virus can also be maintained in an enzoot ...	1999	11000958
[expression of non-structural region 3 gene of the chinese hgy and analysis of the antigenicity of the recombinant proteins].	this study is to analyze the antigenicity of the ns3 proteins of chinese hgv and their potential use in the serological diagnosis.	1999	12569774
[a study of hgv infection in liver tissue of hepatocellular carcinoma].	to investigate the prevalence of hepatitis g virus (hgv) in hepatocellular carcinoma (hcc).	1999	12569791
use of the vaccinia virus/t7 expression system for studying hcv protein processing.	hcv and related viruses are now classified as a separate genus in the family flaviviridae (1), which includes two other genera, flavivirus (2), and pestivirus (3). the positive-strand hcv genome rna is approx 9.4 kb in length and contains a highly conserved 5' noncoding region followed by a long open reading frame encoding a polyprotein of 3010-3033 amino acids (4,5) recently, it was determined that the 3' end contains another highly conserved noncoding region approx 100 bp in length (6-8). beca ...	1999	21374371
hepatitis g virus (hgv) and liver diseases.	recently, a new flavi-like virus, provisionally named hepatitis gbv-c or hepatitis g virus (hgv), has been described and was initially thought to be the major etiological agent of non-a-e hepatitis. hgv does not induce an immune response that is consistently detectable by using recombinant proteins from prokaryotic expression and hence prevalence studies have been conducted by using polymerase chain reaction (pcr)-based system. hgv-rna has been detected in many human populations. this article re ...	1999	19864743
diagnosis of turkey meningoencephalitis virus infection in field cases by rt-pcr compared to virus isolation in embryonated eggs and suckling mice.	turkey meningoencephalitis (tme) is a paralytic epornitic disease of turkeys caused by turkey meningoencephalitis virus (tmev), an arthopod-borne flavivirus belonging to the ntaya serogroup vi. a tmev specific rt-pcr was compared with classical techniques for tmev diagnosis, which include virus isolation in 8-day-old chicken embryonated eggs and suckling mice, on 17 tme flocks with neurological signs that occurred during the fall of 1997. in 11/17 flocks both the rt-pcr and the virus isolation m ...	2000	19184786
prospective follow-up of patients with gbv-c/hgv infection: specific mutational patterns, clinical outcome, and genetic diversity.	an association between a specific mutational pattern within the nonstructural (ns)3 region of gb virus-c/hepatitis g virus (gbv-c/hgv) genome and fulminant hepatic failure has been suggested recently. the mutational pattern consists of 3-6 nucleotide mutations of which one is leading to an amino acid exchange. in the present study, patients with gbv-c/hgv mono-infection (n = 24) or gbv-c/hgv and hcv co-infection (n = 20) were investigated prospectively. in 6/44 patients (14%) the mutational patt ...	2000	11002248
single amino acid differences are sufficient for cd4(+) t-cell recognition of a heterologous virus by cattle persistently infected with bovine viral diarrhea virus.	cattle that are persistently infected (pi) with one strain of bovine viral diarrhea virus (bvdv) can resolve infection with a second, antigenically heterologous strain but not the homologous strain. since cd4(+) t cells are thought to be critical for the resolution of acute bvdv infection (howard et al., 1992, vet. immunol. immunopathol. 32, 303-314), we have examined the recognition of a heterologous virus (nadl) by cd4(+) t cells from pe515-pi animals. the immune response of non-pi control cat ...	2000	11021996
[circulation of virus and interspecies contamination in wild animals].	paradoxically, just when we have succeeded in eradicating and/or bringing under control the major viral infections (smallpox, poliomyelitis, measles) numerous viral infections are emerging in man and in animals. changes in our social environment, technological and ecological equilibrium have facilitated this phenomenon. furthermore, certain of these viruses have demonstrated an almost unlimited capacity to adapt genetically to environmental change. hiv has already infected 40 million individuals ...	2000	11030047
west nile viral encephalitis.	west nile virus (wnv) has emerged in recent years in temperate regions of europe and north america, presenting a threat to both public and animal health. the most serious manifestation of infection is fatal encephalitis in humans and horses, as well as mortality in certain domestic and wild birds. a recent development in the epizootiology of this mosquito-borne flavivirus was the occurrence of a severe outbreak in new york city and surrounding areas. during this outbreak, mortality was observed ...	2000	11189714
west nile virus investigations in south moravia, czechland.	seven virus isolates were obtained from 11,334 mosquitoes after the 1997 morava river flooding in south moravia (czech republic): 6 strains of tahyna bunyavirus, california antigenic group (5 from aedes vexans, 1 from ae. cinereus), and 1 strain of west nile flavivirus (wnv) from culex pipiens. in 1999, one isolate of tahyna virus from ae. vexans and one isolate of wnv from cx. pipiens were recovered from a total of 14,354 mosquitoes examined in the same area, whereas no virus was detected there ...	2000	11192289
west nile encephalitis.	wnv encephalitis in horses, previously reported in africa, asia, and europe, occurred for the first time in the western hemisphere in 1999. the causative agent, wnv, is a flavivirus maintained in nature by a bird-mosquito cycle. the disease in horses is manifested primarily by ataxia of variable severity. outbreaks of encephalitis may have a case fatality rate in excess of 40%, although this virus infection is inapparent in some horses. early evidence indicates that wnv has overwintered in the n ...	2000	11219341
japanese encephalitis.	japanese encephalitis (je) virus is a mosquito-borne flavivirus that can cause encephalitis and death in horses and humans. it is an emerging disease of international concern because it has been spreading into previously nonendemic areas. major epidemics may occur where the virus moves into new areas, but many infections are subclinical. this article presents information on the virus, its epidemiology, and what little information has been published on the disease in horses. the methods available ...	2000	11219350
genetic variation of japanese encephalitis virus in taiwan.	a 280-nucleotide sequence from the capsid-premembrane (c/prem) gene region of 44 japanese encephalitis (je) virus strains isolated in taiwan from mosquitoes from 1983 to 1994, and 3 strains, (ling [1965], chang [1965], and hv1 [1958]) isolated from human brain were analyzed by direct sequencing of reverse transcription-polymerase chain reaction (rt-pcr) amplified products and compared with the corresponding sequences of reference strains. the overall sequence homology of the 47 isolates was > or ...	2000	11220759
replicon-based vectors of positive strand rna viruses.	vectors based on self-replicating rnas (replicons) of positive strand rna viruses are becoming powerful tools for gene expression in mammalian cells and for the development of novel antiviral and anticancer vaccines. a relatively small genome size and simple procedure allow rapid generation of recombinants. cytoplasmic rna amplification eliminates nuclear involvement and leads to extremely high levels of gene expression, and continuous synthesis of double stranded rna results in induction of enh ...	2000	11249758
production of active mammalian and viral proteases in bacterial expression systems.		2000	11255667
isolation of japanese encephalitis virus from mosquitoes (diptera: culicidae) collected in the western province of papua new guinea, 1997-1998.	after japanese encephalitis (je) virus emerged in the torres strait in australia in 1995, investigations were initiated into the origin of the incursion. new guinea was considered the most likely source, given its proximity to islands of the torres strait. almost 400,000 adult mosquitoes were processed for virus isolation from 26 locations in the western province of papua new guinea (png) between february 1996 and february 1998, yielding three isolates of je virus. two isolates of murray valley ...	2000	11289676
dengue virus specific t cell responses to live attenuated monovalent dengue-2 and tetravalent dengue vaccines.	the proliferative t cell responses to dengue vaccines were studied using the parental strains of dengue vaccines as antigens in 26 dengue immune individuals who resided in bangkok which is the endemic area of dengue infection. the magnitude of the t cell responses in subjects with flavivirus cross-reactive neutralizing antibody was much higher and the cross-reactivity was broader than in those with dengue serotype-specific neutralizing antibodies, japanese encephalitis (je) specific antibodies o ...	2000	11316044
distribution of dengue and japanese encephalitis among children in rural and suburban thai villages.	in the rainy season of 1989, igg and igm antibodies against dengue and japanese encephalitis viruses (measured by enzyme-linked immunoassay [elisa]) in serum from all primary-school children in two areas of central thailand were sampled in order to choose a study site for more detailed epidemiological and entomological analysis. students in three schools in the largely non-agricultural, suburban community of bang bua thong, nontaburi province were sampled in late june and july. of 1,477 children ...	2000	11357991
enzootic transmission of deer tick virus in new england and wisconsin sites.	to determine whether rodents that are intensely exposed to the deer tick-transmitted agents of lyme disease, human granulocytic ehrlichiosis, and human babesiosis are also exposed to deer tick virus (dtv), we assayed serum samples from white-footed mice (peromyscus leucopus) and meadow voles (microtus pennsylvanicus) in sites densely infested by deer ticks. to conduct serosurveys, we developed an enzyme-linked immunosorbent assay (elisa) and western blot assay by cloning, expressing, and purifyi ...	2000	11357992
encephalitis and retarded growth of chicks caused by sitiawan virus, a new isolate belonging to the genus flavivirus.	a new virus named sitiawan virus (sv) was isolated from sick broiler chicks in chicken embryos. the virus replicated well with cytopathogenic effect (cpe) in the chicken b-lymphocyte cell line lscc-bk3. the virus was an enveloped rna virus of approximately 41 nm in size with hemagglutinating activity (ha) to goose erythrocytes. it was cross-reactive with japanese encephalitis virus (jev), a member of flaviviruses by ha inhibition tests but not by cross-virus neutralization tests. the cdna fragme ...	2000	11358004
[hepatitis c virus infection mimicking hemorrhagic fever: a case report]	acute c hepatitis, compared with hepatitis a or b, may sometimes be associated with extrahepatic manifestations of a haematologic nature. the first case of hepatitis associated with aplastic anemia was reported by lorenz in 1955. we observed a patient who developed acute hepatitis, associated with febrile purpura: pancytopenia was present, but not aplasia. this association is frequent in flavivirus-related infections, like dengue and yellow fever, and principally affects children and young peopl ...	2000	12714845
gb virus c/hepatitis g virus infections in traumatologic outpatients, chronic non-a-e hepatitis and extrahepatic malignancies.	gb virus c/hepatitis g virus (gbv-c/hgv) is a recently discovered flavivirus of still unknown pathogenic relevance. we examined traumatologic outpatients to determine gbv-c/hgv viremia for further epidemiological studies, as blood donors hitherto used as controls represent healthy individuals without risk factors. anti-gbv-c/hgv antibodies were detectable in 13.2% (95% confidence interval [ci] 9.3-18.2) and gbv-c/hgv rna was detectable in 4.5% (95% ci 2.4-8.2) of the outpatients. in chronic non- ...	2000	10697788
chimeric dengue type 2 (vaccine strain pdk-53)/dengue type 1 virus as a potential candidate dengue type 1 virus vaccine.	we constructed chimeric dengue type 2/type 1 (den-2/den-1) viruses containing the nonstructural genes of den-2 16681 virus or its vaccine derivative, strain pdk-53, and the structural genes (encoding capsid protein, premembrane protein, and envelope glycoprotein) of den-1 16007 virus or its vaccine derivative, strain pdk-13. we previously reported that attenuation markers of den-2 pdk-53 virus were encoded by genetic loci located outside the structural gene region of the pdk-53 virus genome. chi ...	2000	10708416
cis- and trans-acting elements in flavivirus rna replication.	most of the seven flavivirus nonstructural proteins (ns1 to ns5) encoded in the distal two-thirds of the rna positive-sense genome are believed to be essential components of rna replication complexes. to explore the functional relationships of these components in rna replication, we used trans-complementation analysis of full-length infectious rnas of kunjin (kun) virus with a range of lethal in-frame deletions in the nonstructural coding region, using as helper a repbhk cell line stably produci ...	2000	10708442
comparison of panbio dengue duo igm and igg capture elisa and venture technologies dengue igm and igg dot blot.	a number of commercial elisa for dengue diagnosis have recently become available, though direct comparison between these assays have not been published.	2000	10720818
the west nile virus outbreak of 1999 in new york: the flushing hospital experience.	west nile virus (wnv) is a mosquito-borne flavivirus, which has been known to cause human infection in africa, the middle east, and southwestern asia. it has also been isolated in australia and sporadically in europe but never in the americas. clinical features include acute fever, severe myalgias, headache, conjunctivitis, lymphadenopathy, and a roseolar rash. rarely is encephalitis or meningitis seen. during the month of august 1999, a cluster of 5 patients with fever, confusion, and weakness ...	2000	10722421
gb virus c/hepatitis g virus infection is frequent in american children and young adults.	the novel flavivirus gb virus c/hepatitis g virus (gbv-c/hgv) has been detected in approximately 2% of blood donors in the united states, and neutralizing antibody to the envelope protein (e2), a marker of previous infection with gbv-c/hgv, is present in approximately 9% of donors. the rate of gbv-c/hgv infection among american children is unknown. to determine whether viral infection might occur during childhood, 160 serum specimens (obtained from blood bank samples) from children and young adu ...	2000	10722444
infectious cdna clones of langat tick-borne flavivirus that differ from their parent in peripheral neurovirulence.	tick-borne flavivirus strain langat tp21 (lgt tp21) recovered from ticks, is naturally attenuated for humans but retains demonstrable neurovirulence and peripheral virulence ("neuroinvasiveness") for mice. previously a mutant, strain e5, less virulent for mice was derived from lgt tp21. multiple attempts to prepare a full-length infectious tp21 cdna from cdna fragments cloned in e. coli were uniformly unsuccessful. a more informative sequence than that obtained from these cloned cdna fragments a ...	2000	10725214
bovine viral diarrhoea virus and bovine herpesvirus-1 prime uninfected macrophages for lipopolysaccharide-triggered apoptosis by interferon-dependent and -independent pathways.	the flavivirus bovine viral diarrhoea (bvd) virus exists in two biotypes, cytopathic (cp) and non-cytopathic (ncp), defined by their effect on cultured cells. cp bvd virus-infected cells undergo apoptosis and may promote apoptosis in uninfected cells by an indirect mechanism. macrophages (mφ) infected with cp, but not ncp, bvd virus release a factor(s) in the supernatant capable of priming uninfected mφ for activation-induced apoptosis in response to lipopolysaccharide. a possible role o ...	2000	10725412
gb virus c/hepatitis g virus infection in saudi arabian blood donors and patients with cryptogenic hepatitis.	viral hepatitis is a common infection in the developing countries. aside from hepatitis a-e viruses, a novel hepatitis virus termed gbv-c, or hgv, was recently described. we have studied the prevalence of this virus among saudi arabian healthy blood donors (n = 200) and patients with cryptogenic (non-a-e) hepatitis (n=71). after serum extraction and rna reverse transcription, amplification was carried out by the polymerase chain reaction (pcr), using primers for the 5' noncoding region (ncr), ns ...	2000	10664407
transient expression of cellular polypyrimidine-tract binding protein stimulates cap-independent translation directed by both picornaviral and flaviviral internal ribosome entry sites in vivo.	the regulation of cap-independent translation directed by the internal ribosome entry sites (iress) present in some viral and cellular rnas is poorly understood. polypyrimidine-tract binding protein (ptb) binds specifically to several viral iress. ires-directed translation may be reduced in cell-free systems that are depleted of ptb and restored by reconstitution of lysates with recombinant ptb. however, there are no data concerning the effects of ptb on ires-directed translation in vivo. we tra ...	2000	10669736
phylogeny of the genus flavivirus using complete coding sequences of arthropod-borne viruses and viruses with no known vector.	attempts to define the evolutionary relationships and origins of viruses in the genus flavivirus are hampered by the lack of genetic information particularly amongst the non-vectored flaviviruses. using a novel protocol for sequence determination, the first complete coding sequence of st louis encephalitis virus and those of two representative non-vectored flaviviruses, rio bravo (isolated from bat) and apoi (isolated from rodent), are reported. the encoded polyproteins of rio bravo and apoi vir ...	2000	10675416
japanese encephalitis dna vaccine candidates expressing premembrane and envelope genes induce virus-specific memory b cells and long-lasting antibodies in swine.	swine are an important amplifier of japanese encephalitis (je) virus in the paradomestic environment. in this study, two je dna vaccine candidates were evaluated for immunogenicity in swine. both vaccine plasmids encode a cassette consisting of the signal of premembrane (prm), prm, and envelope (e) coding regions of je virus. one plasmid, designated pcjeme, is based on a commercial vector (pcdna3), whereas the other plasmid, designated pnjeme, is based on a vector (pngvl4a) designed to address s ...	2000	10683326
a case of dengue from pune, india.	dengue is an acute infectious disease, caused by a single stranded ribonucleic acid (rna) virus of the family of flaviviridae, genus flavivirus, transmitted by aedes mosquitos, the most important vectors being aedes aegypti and aedes albopictus. there are four serotypes, den-1, den-2, den-3, den-4 that are nearly human specific. the geographical distribution of dengue is pantropical, except for madagascar and some african regions. it is endemo-epidemic in tropical and subtropical countries inclu ...	2000	10689245
rna viruses: emerging vectors for vaccination and gene therapy.	the application of modern molecular techniques has profoundly influenced our understanding of virus function. as a consequence, virus biology is being directly applied to medical research. it is a reflection of the current pace of virology that we are now beginning to think of our ancient foes as useful and beneficial tools.	2000	10637572
chimeric yellow fever virus 17d-japanese encephalitis virus vaccine: dose-response effectiveness and extended safety testing in rhesus monkeys.	chimerivax-je is a live, attenuated recombinant virus prepared by replacing the genes encoding two structural proteins (prm and e) of yellow fever 17d virus with the corresponding genes of an attenuated strain of japanese encephalitis virus (je), sa14-14-2 (t. j. chambers et al., j. virol. 73:3095-3101, 1999). since the prm and e proteins contain antigens conferring protective humoral and cellular immunity, the immune response to vaccination is directed principally at je. the prm-e genome sequen ...	2000	10644345
identification and characterization of the rna helicase activity of japanese encephalitis virus ns3 protein.	the ns3 protein of japanese encephalitis virus (jev) contains motifs typical of rna helicase/ntpase but no rna helicase activity has been reported for this protein. to identify and characterize the rna helicase activity of jev ns3, a truncated form of the protein with a his-tag was expressed in escherichia coli and purified. the purified jev ns3 protein showed an rna helicase activity, which was dependent on divalent cations and atp. an asp-285-to-ala substitution in motif ii of the jev ns3 prot ...	2000	10620709
mutational analysis of the gb virus b internal ribosome entry site.	gb virus b (gbv-b) is a recently discovered hepatotropic flavivirus that is distantly related to hepatitis c virus (hcv). we show here that translation of its polyprotein is initiated by internal entry of ribosomes on gbv-b rna. we analyzed the translational activity of dicistronic rna transcripts containing wild-type or mutated 5' nontranslated gbv-b rna (5'ntr) segments, placed between the coding sequences of two reporter proteins, in vitro in rabbit reticulocyte lysate and in vivo in transfec ...	2000	10623739
mutagenesis of the signal sequence of yellow fever virus prm protein: enhancement of signalase cleavage in vitro is lethal for virus production.	proteolytic processing at the c-prm junction in the flavivirus polyprotein involves coordinated cleavages at the cytoplasmic and luminal sides of an internal signal sequence. we have introduced at the cooh terminus of the yellow fever virus (yfv) prm signal sequence amino acid substitutions (vpqaqa mutation) which uncoupled efficient signal peptidase cleavage of the prm protein from its dependence on prior cleavage in the cytoplasm of the c protein mediated by the viral ns2b-3 protease. infectiv ...	2000	10590087
gb virus-c/hepatitis g virus infection in a hepatitis c virus endemic village: prevalence in residents with low educational attainment and frequent recovery in females.	gb virus-c/hepatitis g virus (hgv) is a newly identified flavivirus, which may share the same mode of transmission as hepatitis c virus (hcv). the aim of this study was to investigate associated factors of hgv infection and clearance in a hcv endemic village in southern taiwan.	2000	10902972
migratory birds and spread of west nile virus in the western hemisphere.	west nile virus, an old world flavivirus related to st. louis encephalitis virus, was first recorded in the new world during august 1999 in the borough of queens, new york city. through october 1999, 62 patients, 7 of whom died, had confirmed infections with the virus. ornithophilic mosquitoes are the principal vectors of west nile virus in the old world, and birds of several species, chiefly migrants, appear to be the major introductory or amplifying hosts. if transovarial transmission or survi ...	2000	10905964
isolation of two strains of west nile virus during an outbreak in southern russia, 1999.	from july to september 1999, a widespread outbreak of meningoencephalitis associated with west nile virus (flavivirus, flaviviridae) occurred in southern russia, with hundreds of cases and dozens of deaths. two strains of west nile virus isolated from patient serum and brain-tissue samples reacted in hemagglutination-inhibition and neutralization tests with patients' convalescent-phase sera and immune ascites fluid from other strains of west nile virus.	2000	10905970
solid phase synthesis of aminoboronic acids: potent inhibitors of the hepatitis c virus ns3 proteinase.	use of a resin bound diol as a boronic acid protecting group has been developed to allow the parallel synthesis of potent inhibitors of the hepatitis c virus ns3 serine proteinase.	2000	10915055
role of the dexh motif of the japanese encephalitis virus and hepatitis c virus ns3 proteins in the atpase and rna helicase activities.	the role of the conserved dexh motif of the japanese encephalitis virus (jev) ns3 protein in the atpase and rna helicase activities was compared with that of the hepatitis c virus (hcv) ns3 protein. in the dexh motif of jev ns3, asp-285 and glu-286 were essential for both atpase and rna helicase activities. cys-287 was critical for the rna helicase activity of jev ns3 but not for atpase activity. a his-288-to-ala substitution in the dexh motif of hcv ns3 resulted in an increase in atpase activit ...	2000	10915602
ns3 serine protease of bovine viral diarrhea virus: characterization of active site residues, ns4a cofactor domain, and protease-cofactor interactions.	the gene expression of bovine viral diarrhea virus (bvdv), a pestivirus, occurs via translation of a hypothetical polyprotein that is processed cotranslationally and posttranslationally by viral and cellular enzymes. a protease located in the n-terminal region of nonstructural (ns) protein ns3 catalyzes the cleavages, leading to the release of ns4a, ns4b, ns5a, and ns5b. our study provides experimental evidence that histidine at position 1658 and aspartic acid at position 1686 constitute togethe ...	2000	10915606
[ocular manifestation in dengue fever].	dengue-fever is a mosquito transmitted viral disease. it is endemic mainly in south-east asia and africa. the clinical manifestation is divided into different stages. ocular manifestations in travellers have been rarely reported.	2000	10916388
[identification of the encephalitis equine virus, parana, brazil].	in the period of 1996-1999 some virus associated with encephalitis have been reported in horses from different regions of paraná state, brazil. to identify the etiologic agent associated with this illness, mosquitoes and serum samples were collected in the endemic area.	2000	10920444
[serological survey on arbovirus infection in residents of an ecological reserve].	serological inquires conducted in the ribeira valley, s. paulo state, brazil, showed an intense circulation of pathogenic arboviruses in the region. the goal was to verify the prevalence of arboviral infections in people living at the local ecological, and its potential association with these population' individual and familiar characteristics.	2000	10920445
the molecular epidemiology of kokobera virus.	we describe herein the molecular epidemiology and phylogeny of kokobera (kok) virus, a flavivirus found in australia and papua new guinea. we sequenced a region encompassing the 200 nucleotides of the 3' terminus of the ns5 gene, and the first 300 nucleotides of the 3' untranslated region (utr). the study included 25 isolates of the virus, including an isolate from png, and several recent isolates from the south-west of western australia (wa), where the virus had not previously been detected. we ...	2000	10930658
chimeric yellow fever/dengue virus as a candidate dengue vaccine: quantitation of the dengue virus-specific cd8 t-cell response.	we have constructed a chimeric yellow fever/dengue (yf/den) virus, which expresses the premembrane (prm) and envelope (e) genes from den type 2 (den-2) virus in a yf virus (yfv-17d) genetic background. immunization of balb/c mice with this chimeric virus induced a cd8 t-cell response specific for the den-2 virus prm and e proteins. this response protected yf/den virus-immunized mice against lethal dengue encephalitis. control mice immunized with the parental yfv-17d were not protected against de ...	2000	10933719
gbv-c/hgv genotypes: proposed nomenclature for genotypes 1-5.	the gb virus-c and hepatitis g virus (gbv-c/hgv) are variants of the same flavivirus. this proposal attempts to clarify the conflicting nomenclature for gbv-c/hgv genotypes. the first three genotypes described were genotype 1 (west africa); genotype 2 (us/europe) and genotype 3 (asia). subsequently, two groups published data from south africa and southeast asia both stating the presence of a novel "4th genotype." these isolates are distinct phylogenetically. it is proposed that the nomenclature ...	2000	10935992
chimeric langat/dengue viruses protect mice from heterologous challenge with the highly virulent strains of tick-borne encephalitis virus.	langat virus (lgt), a tick-borne flavivirus, is naturally attenuated for humans but it is very virulent in scid mice. in contrast, viable recombinant chimeras of lgt (prem and e genes) and dengue type 4 virus (all other sequences) recovered in mosquito cell culture were completely attenuated in scid mice but still capable of providing protection against lgt. to develop the chimeras into vaccine candidates, we adapted them to replicate efficiently in simian vero cells, a satisfactory substrate fo ...	2000	10936085