Publications

a focus of deer tick virus transmission in the northcentral united states.	we screened salivary glands from adult deer ticks collected near spooner and hayward, wisconsin, to determine whether deer tick virus, a recently described flavivirus, occurs with other tickborne agents in the upper midwest. intraacinar inclusions suggestive of replicating virus were detected in 4 (4.6%) of 87 ticks. the virus was isolated by suckling-mouse inoculation.	1999	10460180
fatal dengue hemorrhagic fever in cuba, 1997.	after more than 15 years without dengue activity, a dengue ii epidemic was reported in cuba in 1997. three thousand and twelve serologically confirmed cases were reported, with 205 dengue hemorrhagic fever/dengue shock syndrome (dhf/dss) cases and 12 fatalities. this report presents the clinical, serologic, and virologic findings in the 12 fatal dhf/dss cases.	1999	10460923
identification of genetic variation among st. louis encephalitis virus isolates, using single-strand conformation polymorphism analysis.	a single-strand conformation polymorphism (sscp) technique was developed for identification of genetic variation among 26 isolates of st. louis encephalitis (sle) virus. a 750-bp portion of the envelope gene was amplified by reverse transcription-polymerase chain reaction (rt-pcr) and the products analyzed by sscp. sscp reliably identified genetic variation among the isolates from the us, central and south america. closely related isolates from a smaller geographic area (panama) were also distin ...	1999	10471026
synthesis of new photocross-linking 5-c-base-substituted utp analogs and their application in highly selective affinity labelling of the tick-borne encephalitis virus rna replicase proteins.	a new photocross-linking 5-c-base-substituted utp analogs, carrying 4-azidoperfluorobenzoyl and 4-azidoaniline residues were synthesized. two flavivirus proteins ns5 and ns3 are shown to be labelled after rna synthesis in the presence of the analogs, irradiation (lambda > 300 nm) and subsequent [alpha-32p]ntp incorporation.	1999	10474230
unlicensed vaccines and bioweapon defense in world war ii.		1999	10478686
mutagenesis of the ns2b-ns3-mediated cleavage site in the flavivirus capsid protein demonstrates a requirement for coordinated processing.	analysis of flavivirus polyprotein processing has revealed the presence of a substrate for the virus-encoded ns2b-ns3 protease at the carboxy-terminal end of the c (capsid or core) protein. cleavage at this site has been implicated in the efficient generation of the amino terminus of prm via signal peptidase cleavage. yellow fever virus has four basic residues (arg-lys-arg-arg) in the p1 through p4 positions of this cleavage site. multiple alanine substitutions were made for these residues in or ...	1999	10482557
[tick-encephalitis after a vacation in southern germany].	a 38-year-old man was admitted with signs of meningoencephalitis. tick-borne encephalitis was considered because the patient reported a tick bite during a vacation in south germany and because of the biphasic course of the symptoms. serology for tick-borne encephalitis was positive: this constituted the first reported positive serology outcome in the national institute for public health and environment in the netherlands. tick-borne encephalitis is an infection with a flavivirus transmitted by a ...	1999	10494331
nucleoside triphosphatase and rna helicase activities associated with gb virus b nonstructural protein 3.	gb virus b (gbv-b) is a positive-stranded rna virus that belongs to the flaviviridae family. this virus is closely related to hepatitis c virus (hcv) and causes acute hepatitis in tamarins (saguinus species). nonstructural protein 3 (ns3) of gbv-b contains sequence motifs predictive of three enzymatic activities: serine protease, nucleoside triphosphatase (ntpase), and rna helicase. the n-terminal serine protease has been characterized and shown to share similar substrate specificity with the hc ...	1999	10497107
molecular and biological changes associated with hela cell attenuation of wild-type yellow fever virus.	six passages of the mosquito-borne flavivirus yellow fever (yf) wild-type strain asibi in hela cells attenuated the virus for monkeys and newborn mice and resulted in loss of mosquito competence. attenuation after the passage in hela cells was not unique to yf virus strain asibi as demonstrated by the hela passage attenuation of wild-type yf virus strain french viscerotropic virus and yf vaccine virus 17d-204 for newborn mice. in contrast, wild-type strain dakar 1279 and the french neurotropic v ...	1999	10497116
trans-complementation analysis of the flavivirus kunjin ns5 gene reveals an essential role for translation of its n-terminal half in rna replication.	recently we described rescue of defective kunjin virus (kun) rnas with small deletions in the methyltransferase and rna polymerase motifs of the ns5 gene, using bhk cells stably expressing kun replicon rna (repbhk cells) as helper (a. a. khromykh et al., j. virol. 72:7270-7279, 1998). we have now extended our previous observations and report successful trans-complementation of defective kun rnas with most of the ns5 gene deleted or substituted with a heterologous (dengue virus) ns5 sequence. rep ...	1999	10516033
markers for trans-golgi membranes and the intermediate compartment localize to induced membranes with distinct replication functions in flavivirus-infected cells.	replication of the flavivirus kunjin virus is associated with virus-induced membrane structures within the cytoplasm of infected cells; these membranes appear as packets of vesicles associated with the sites of viral rna synthesis and as convoluted membranes (cm) and paracrystalline arrays (pc) containing the components of the virus-specified protease (e. g. westaway, j. m. mackenzie, m. t. kenney, m. k. jones, and a. a. khromykh, j. virol. 71:6650-6661, 1997). to determine the cellular origins ...	1999	10516064
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
report on ticks collected in the southeast and mid-west regions of brazil: analyzing the potential transmission of tick-borne pathogens to man.	specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the southeast and mid-west regions of brazil. nine species of amblyommidae were identified: anocentor nitens, amblyomma cajennense, amblyomma ovale, amblyomma fulvum, amblyomma striatum, amblyomma rotundatum, boophilus microplus, boophilus annulatus, and rhipicephalus sanguineus. the potential of these tick species as transmitters of pathogens to man was analyzed. a flaviviridade flavivirus ...	1999	10881097
[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
analysis of murine cd8(+) t-cell clones specific for the dengue virus ns3 protein: flavivirus cross-reactivity and influence of infecting serotype.	serotype-cross-reactive dengue virus-specific cytotoxic t lymphocytes (ctl) induced during a primary dengue virus infection are thought to play a role in the immunopathogenesis of dengue hemorrhagic fever (dhf) during a secondary dengue virus infection. although there is no animal model of dhf, we previously reported that murine dengue virus-specific ctl responses are qualitatively similar to human dengue virus-specific ctl responses. we used balb/c mice to study the specificity of the ctl respo ...	1999	9847344
a phylogenetically conserved stem-loop structure at the 5' border of the internal ribosome entry site of hepatitis c virus is required for cap-independent viral translation.	hepatitis c virus (hcv) initiates translation of its polyprotein under the control of an internal ribosome entry site (ires) that comprises most of the 341-nucleotide (nt) 5' nontranslated rna (5'ntr). a comparative analysis of related flaviviral sequences suggested that an rna segment for which secondary structure was previously ill defined (domain ii, nt 44 to 118) forms a conserved stem-loop that is located at the 5' border of the hcv ires and thus may function in viral translation. this pred ...	1999	9882318
sequence analysis and genetic classification of tick-borne encephalitis viruses from europe and asia.	the epidemiology of tick-borne encephalitis virus was investigated by comparative sequence analysis of virus strains isolated in endemic areas of europe and asia. phylogenetic relationships were determined from the nucleotide and amino acid sequences of the major envelope (e) protein of 16 newly sequenced strains and nine previously published sequences. three genetic lineages could be clearly distinguished, corresponding to a european, a far eastern and a siberian subtype. amino acids characteri ...	1999	9934700
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
use of a fluorescence plate reader for measuring kinetic parameters with inner filter effect correction.	a general method is presented here for the determination of the km, kcat, and kcat/km of fluorescence resonance energy transfer (fret) substrates using a fluorescence plate reader. a simple empirical method for correcting for the inner filter effect is shown to enable accurate and undistorted measurements of these very important kinetic parameters. inner filter effect corrected rates of hydrolysis of a fret peptide substrate by hepatitis c virus (hcv) ns3 protease at various substrate concentrat ...	1999	10036138
sequence heterogeneity within three different regions of the hepatitis g virus genome.	two sets of primers derived from the 5'-terminal region and the ns5 region of the hepatitis g virus (hgv) genome were used to amplify pcr fragments from serum specimens obtained from different parts of the world. all pcr fragments from the 5'-terminal region (5'-pcr, n = 56) and from the ns5 region (ns5-pcr, n = 85) were sequenced and compared to corresponding published hgv sequences. the range of nucleotide sequence similarity varied from 74 and 78% to 100% for 5'-pcr and ns5-pcr fragments, res ...	1999	10069950
noncytopathic flavivirus replicon rna-based system for expression and delivery of heterologous genes.	noncytopathic replicons of the flavivirus kunjin (kun) were employed for expression and delivery of heterologous genes. replicon vector c20dx2arep, containing a unique cloning site followed by the sequence of 2a autoprotease of foot-and-mouth disease virus, was constructed and used for expression of a number of heterologous genes including chloramphenicol acetyltransferase (cat), green fluorescent protein (gfp), beta-galactosidase, glycoprotein g of vesicular stomatitis virus, and the core and n ...	1999	10069962
yellow fever/japanese encephalitis chimeric viruses: construction and biological properties.	a system has been developed for generating chimeric yellow fever/japanese encephalitis (yf/je) viruses from cdna templates encoding the structural proteins prm and e of je virus within the backbone of a molecular clone of the yf17d strain. chimeric viruses incorporating the proteins of two je strains, sa14-14-2 (human vaccine strain) and je nakayama (je-n [virulent mouse brain-passaged strain]), were studied in cell culture and laboratory mice. the je envelope protein (e) retained antigenic and ...	1999	10074160
the serine protease and rna-stimulated nucleoside triphosphatase and rna helicase functional domains of dengue virus type 2 ns3 converge within a region of 20 amino acids.	ns3 protein of dengue virus type 2 has a serine protease domain within the n-terminal 180 residues. ns2b is required for ns3 to form an active protease involved in processing of the viral polyprotein precursor. the region carboxy terminal to the protease domain has conserved motifs present in several viral rna-stimulated nucleoside triphosphatase (ntpase)/rna helicases. to define the functional domains of protease and ntpase/rna helicase activities of ns3, full-length and amino-terminal deletion ...	1999	10074162
[seroprevalence of central european tick-borne encephalitis in the lorraine region].	central european encephalitis, caused by the tick-borne encephalitis virus (tbev), is exceptional in france. most cases have been described in alsace. as 2 cases of tick-borne encephalitis were diagnosed in the nancy region, a seroepidemiological survey was conducted in the lorraine region (meurthe & moselle, moselle, vosges, meuse) in 1996.	1999	10076595
mosquito feeding modulates th1 and th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice.	culex pipiens and aedes aegypti mosquitoes were fed on c3h/hej mice and systemic cytokine production was quantified from stimulated lymphocytes harvested four to ten days after feeding. mosquito feeding on c3h/hej mice significantly down regulated ifn gamma production seven to ten days post feeding by cx. pipiens and seven days after ae aegypti feeding. th2 cytokines, il-4 and il-10, were significantly up regulated 4-7 days after cx. pipiens and ae. aegypti feeding. the immunosuppressive effect ...	1999	10081770
[yellow fever].		1999	10088360
detection of gb virus c/hepatitis g virus rna by reverse-transcription polymerase chain reaction.	recently, a novel rna virus, designated gb virus c or hepatitis g virus (gbv-c/hgv) has been identified which may possibly be associated with human hepatitis. in this study, the nucleotide sequences of the partial nonstructural 5 (ns5) gene of gbv-c/hgv derived from sera of eight chinese patients were determined. the overall degree of nucleotide conservation and the existence of regional highly conserved sequences make this part of the genome suitable for the development of diagnostic reagents. ...	1999	10094376
preliminary studies on the use of solid-phase immunosorbent techniques for the rapid detection of wesselsbron virus (wslv) igm by haemagglutination-inhibition.	serum samples from 446 randomly selected persons belonging to different age groups and locations in nigeria were tested for the presence of wslv igm using the flavivirus haemagglutination-inhibition (hi) test adopted to the solid-phase immunosorbent technique (spit). 61 (14%) persons had igm to wslv only, while 9 (2%) persons had heterologous igm to wslv and two other flaviviruses, namely yellow fever and uganda s viruses. there was a high prevalence of igm in people of younger age groups than t ...	1999	10099030
[preparation of single-chained antibodies to surface glycoprotein e from tick-borne encephalitis virus].	a single-stranded antibody gene scfv was designed on the base of cdna fragments of genes coding for variable domains of heavy and light chains of mab e6b to tick-borne encephalitis glycoprotein e. high production of stable soluble scfv was reproduced in escherichia coli cells. recombinant antibodies bound to antiidiotypical antibodies to initial mab e6b and to recombinant virus protein e. competitive analysis showed that single-stranded antibodies inhibited reaction between mab e6b and protein e ...	1999	10190234
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
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
antigenic relatedness of selected flaviviruses: study with homologous and heterologous immune mouse ascitic fluids.	the antigenic relationship of 9 flaviviruses, yellow fever (yf), wesselsbron (wsl), uganda s (ugs), potiskum (pot), west nile (wn), banzi (ban), zika (zk), dengue type 1 (den-1) and dengue type 2 (den-2), was assessed by cross-haemagglutination-inhibition (cross-hi) and cross-complement fixation (cross-cf) reactions between each of the viruses and their homologous immune mouse ascitic fluids. titre ratios were calculated using the heterologous and homologous titres. cross-cf reactions revealed w ...	1998	10436653
prevalence of hepatitis g virus rna in human immunodeficiency virus type 1-positive intravenous drug users.	the aim of this study was to evaluate the prevalence of the new human flavivirus hepatitis g virus (hgv) in italian intravenous drug users (idus) and its interaction with human immunodeficiency virus type 1 (hiv-1) and hepatitis c virus (hcv).	1998	10195238
[molecular biology of dengue virus].	in venezuela the problem of dengue infection has become worst during the last decade, turning the country into an hyperendemic region where three of the four serotypes co-circulate. the dengue has become a problem of public health, so the knowledge of the virus, its life cycle and characteristics, as well as the different aspects related with its biology are extremely important to fight the virus and for the develop of a vaccine. in a general way, the present work describes different aspects rel ...	1998	10030047
[laboratory diagnosis to dengue virus infections].	currently, laboratory diagnosis of dengue virus infection has a special importance because of its emerging character, showing a great geographic propagation of viral activity through out the american continent. in general, the laboratory diagnosis of dengue infections is similar to other human infecting viruses, the difference and difficulty of the process lies in the cross reaction activity with other flavivirus that can co-exist in the same region. the effectiveness of the diagnosis depends on ...	1998	10030051
[prevalence of flavivirus antibodies in young voluntary recruits to military service in the province of formosa, argentina].	the aim of the present study was to investigate the seroprevalence to flavivirus, in young people living in risk areas. we analyzed 189 human sera from 3 towns in the province of formosa. this area corresponds to the border that limits brasil and paraguay and the aim was to search for a possible introduction of dengue and yellow fever from these countries. serological tests such as haemagglutination inhibition (hi), complement fixation (cf) and neutralization (nt) were performed using st. louis ...	1998	9950038
evaluation of a rapid immunochromatographic test for diagnosis of dengue virus infection.	a rapid (<7-min) immunochromatographic test for immunoglobulin m (igm) and igg antibodies to dengue viruses was evaluated by using hospital admission and discharge sera from 124 patients. the reference laboratory diagnosis was based on the results of virus isolation, hemagglutination-inhibition assay (hai), and enzyme immunoassay (eia). by the standard assays, patients experienced primary dengue virus infection (n = 30), secondary dengue virus infection (n = 48), japanese encephalitis (je) virus ...	1998	9431954
prevalence and patterns of hgv/gbv-c infection in patients with suspected hcv-related hepatitis.	hepatitis g virus (hgv) is a recently described hepatotropic parenterally transmitted flavivirus. the presence of hgv was tested in 61 patients with a request for confirmation of hcv active infection. thirty-two patients were in haemodialysis and 29 were referred from wards other than nephrology. active hcv and hgv infections were determined by detection of their viral rna in serum. evaluation of previous hgv infection was carried out by detection of antibodies to e2 antigen. hcv prevalence was ...	1998	9923019
hepatitis g virus infection in lymphoma and in blood donors.	to determine whether the recently described flavivirus, hepatitis g virus (hgv), might contribute to the pathogenesis of lymphoma by testing for the presence of hgv rna in sera from patients attending lymphoma clinics; to compare the incidence of hgv rna in lymphoma patients with that in normal blood donors; and to look for potential risk factors for hgv infection and for evidence of hepatic disease in the hgv positive patients.	1998	9930072
localizations of ns3 and e proteins in mouse brain infected with mutant strain of japanese encephalitis virus.	infection with a mutant japanese encephalitis virus (jev) strain rp-2ms showed reduced neurovirulence than wild type or rp-9 strains after inoculation in balb/c mice. however, higher intracellular viral titer was detected in rp-2ms infected cultured cells. localizations of non-structural 3 (ns3) and envelope (e) proteins were demonstrated by immunocytochemistry. ns3 protein was primarily found in the pyramidal neurons in cerebrum, in the molecular and granular layers of cerebellum. neither e nor ...	1998	9930192
[dengue: a re-emerging disease. a clinical and epidemiological study in 57 spanish travelers].	dengue infection is nowadays considered a re-emergent disease. it has a worldwide tropical and subtropical distribution. the dengue virus in a member of the flavivirus family composed by 4 different serotypes. the virus is transmitted by mosquitos of the aedes genus. with the increment of travels to the endemic areas, dengue is now observed frequently in our country. we analyzed 57 patients, 30 with imported dengue (id) and 27 with dengue fever suffered during the trip (ddt). this series is comp ...	1998	9859093
affinity labelling of the tick-borne encephalitis virus rna replicase proteins by 4-n-exo-base-substituted photoreactive ctp analogs.	4-n-exo-base-substituted photoreactive analogs of ctp were designed and synthesized. two flavivirus proteins ns5 and ns3 are shown to be labelled after rna synthesis in the presence of the analogs, irradiation by uv-light (313 nm) and subsequent [alpha-32p]ntp incorporation.	1998	9871542
japanese encephalitis.		1998	9876271
[antibodies against the west nile virus and other arthropod-transmitted viruses in the ebro delta region].	the west nile virus (wnv) is a flavivirus which is transmitted to man by means of different species of mosquitoes and causes outbreaks and sporadic cases of illness in different regions of the old world, including the mediterranean basin. europe's wetlands which comprise a stopping-off point for birds migrating from africa are high-risk areas as regards this infection, as well as other arthropod-borne virus infections.	1998	9810831
[protein e 98-113 sequence is a fusion site of tick-borne encephalitis virus with cellular membrane].	the synthetic peptide with the conservative 98-113 sequence of protein e of tick-borne encephalitis virus was studied in order to elucidate its role in the functioning of flaviviruses. the peptide was shown to inhibit the in vitro infection of macrophages with the virus. an antibody that specifically binds this peptide was found among the set of monoclonal antibodies produced against protein e. this antibody was found to prevent penetration of the virus into liposomes. a correlation was found be ...	1998	9813732
detection of specific antibodies in saliva during dengue infection.	saliva was collected prospectively from patients presenting with suspected dengue infection 4 to 8 days after the onset of symptoms and assayed by a commercial dengue immunoglobulin m (igm) and igg capture enzyme-linked immunosorbent assay (elisa) (panbio dengue duo elisa). laboratory diagnosis was based on virus isolation and on hemagglutination inhibition (hai) assay and an in-house igm and igg capture elisa. with a positive result defined as either salivary igm or igg levels above the cutoff ...	1998	9817913
growth restriction of dengue virus type 2 by site-specific mutagenesis of virus-encoded glycoproteins.	the three flavivirus glycoproteins prm, e and ns1 are formed by post-translational cleavage and are glycosylated by the addition of n-linked glycans. ns1 may form homodimers, whereas e may form homodimers, homotrimers or heterodimers (prm-e). modification of these processes by mutagenesis of the proteins has the potential to generate viruses that are restricted in growth and are possible vaccine candidates. using an sv40-based expression system, we previously analysed dimerization and secretion ...	1998	9820138
prevalence of hepatitis g-virus infection in alcohol abusing patients with and without liver cirrhosis.	hepatitis g (gbv-c/hgv) is an rna-virus belonging to the flavivirus family and is capable of inducing hepatitis in rare cases. its importance as a co-factor in the pathogenesis of liver disease needs to be clarified.	1998	9823622
[the morphological characteristics of cell death in different forms of acute tick-borne encephalitis].	the study was aimed to identify different types of cell death in monkey brain in flavivirus experimental encephalitis. 10 brain areas most vulnerable ("indicator") of the disease in its different forms (symptomless, intermediate and severe) were examined in animals infected intracerebrally with viruses of tick-borne encephalitis. cells of ectodermal and mesenchymal origin displayed apoptosis that was most pronounced in intermediate form of the severity of the disease. apoptosis was not character ...	1998	9826821
evaluation of an igm immunoblot kit for dengue diagnosis.	a commercial igm immunoblot kit was evaluated for dengue diagnosis with a panel of serum specimens collected from patients in a dengue endemic area. the kit is not recommended for use in its present form because of its undesirable rate of false-positive results. however, by substituting internal controls with the reference positive and negative controls that are more representative of those seen in endemic areas and by modifying the positive and negative scoring criteria, sensitivity and specifi ...	1998	9840593
in vitro-synthesized infectious rna as an attenuated live vaccine in a flavivirus model.	live virus vaccines have in many cases proven to be an extremely effective tool for the prevention of viral diseases. however, the production of conventional live vaccines in eukaryotic cell cultures has many disadvantages, including the potential for contamination with adventitious agents and genetic alterations during propagation, making it necessary to do extensive testing before distribution. based on results obtained with a flavivirus (tick-borne encephalitis virus) in an experimental anima ...	1998	9846585
nucleic acid vaccines against hepatitis viruses.	direct dna intramuscular or intradermal injection of plasmids containing viral genes under the control of viral promoters is an efficient means of stimulating both class i and class ii-mediated antiviral responses. viral hepatitis b and c are suitable candidates for this approach, particularly as therapeutic immunogens for chronically infected individuals. several groups have shown that the s gene of hbv is expressed in murine muscle and stimulates a high titre and long-lasting anti-hbs response ...	1998	9554270
predominance of hla-restricted cytotoxic t-lymphocyte responses to serotype-cross-reactive epitopes on nonstructural proteins following natural secondary dengue virus infection.	we examined the memory cytotoxic t-lymphocytic (ctl) responses of peripheral blood mononuclear cells (pbmc) obtained from patients in thailand 12 months after natural symptomatic secondary dengue virus infection. in all four patients analyzed, ctls were detected in bulk culture pbmc against nonstructural dengue virus proteins. numerous cd4+ and cd8+ ctl lines were generated from the bulk cultures of two patients, kpp94-037 and kpp94-024, which were specific for ns1.2a (ns1 and ns2a collectively) ...	1998	9557687
a 68-nucleotide sequence within the 3' noncoding region of simian hemorrhagic fever virus negative-strand rna binds to four ma104 cell proteins.	the 3' noncoding region (ncr) of the negative-strand rna [3'(-)ncr rna] of the arterivirus simian hemorrhagic fever virus (shfv) is 209 nucleotides (nt) in length. since this 3' region, designated 3'(-)209, is the site of initiation of full-length positive-strand rna and is the template for the synthesis of the 5' leader sequence, which is found on both full-length and subgenomic mrnas, it is likely to contain cis-acting signals for rna synthesis and to interact with cellular and viral proteins ...	1998	9557724
identification of hepatitis g virus particles in human serum by e2-specific monoclonal antibodies generated by dna immunization.	in order to elucidate the structure and morphology of hepatitis g virus (hgv), a recently isolated flavivirus, we generated a panel of eight monoclonal antibodies (mabs) against the putative second envelope protein (e2) following dna immunization. the mabs were shown to be specific for four different epitopes on recombinant e2. mab mc6 was the only antibody able to detect the linear epitope ltggfyepl. in addition, mc6 was able to immunoprecipitate viral particles in human blood samples as detect ...	1998	9557757
[isolation of a complex of tick-borne encephalitis viral proteins by affinity chromatography using monoclonal antibodies to proteins ns5 and ns3].	affinity chromatography of lysates of continuous porcine embryo cells infected with tick-borne encephalitis (tbe) virus on sepharose with immobilized monoclonal antibodies to tbe virus proteins ns5 and ns3 results in isolation of a stable protein complex. this complex contains viral proteins ns5, ns3, p49, and, probably, two more cell proteins. this complex is not detected at the early stage of infection, and 24 h after infection its structure does not depend on the specificity of immobilized mo ...	1998	9559535
[some mechanisms of the action of oligonucleotides: stimulation of the immune system and decreased infection of the brain in tickborne encephalitis].	morphological changes in the thymus, spleen, and brain are analyzed in white mice injected 16-component oligonucleotide (on) pe16 complementary to the ns3 protein gene sequences of tickborne encephalitis (tbe) virus in doses of 1 to 0.001 nm. on stimulated thymic and splenic cells. besides the stimulating effect, injection of on to mice infected with tbe enhanced the destruction of lymphocytes and boosted the macrophagal activity, which was paralleled by a decrease in the intensity of virus-spec ...	1998	9559536
transmission of hepatitis g virus in patients with angioedema treated with steam-heated plasma concentrates of c1 inhibitor.	hepatitis g virus (hgv) is a blood-borne flavivirus that may cause acute and chronic transfusion-transmitted infections. patients with complement component 1 (c1) inhibitor (c1-inh) deficiency may acquire blood-borne infections through infusion of plasma concentrates.	1998	9563413
immunological basis for protection in a murine model of tick-borne encephalitis by a recombinant adenovirus carrying the gene encoding the ns1 non-structural protein.	the humoral immune response to flaviviruses is mainly directed to the major envelope protein, e, and a glycosylated non-structural protein, ns1. cell-mediated immune responses, however, appear to be directed mainly against non-structural proteins. experiments described here show that a defective recombinant adenovirus (rad51) containing the gene encoding the ns1 protein of tick-borne encephalitis virus can induce a strong protective immune response against several pathogenic tick-borne flaviviru ...	1998	9568962
definition of the region on ns3 which contains multiple epitopes recognized by dengue virus serotype-cross-reactive and flavivirus-cross-reactive, hla-dpw2-restricted cd4+ t cell clones.	the epitopes recognized by six cd4+ cd8- cytotoxic t lymphocyte (ctl) clones established from a dengue-3 virus-immune donor were defined. (i) three ctl clones, jk10, jk34 and jk39, were cross-reactive for dengue virus types 1-4. (ii) one clone, jk28, was cross-reactive for dengue virus types 1-4 and west nile virus. (iii) two clones, jk26 and jk49, were cross-reactive for dengue virus types 1-4, west nile virus and yellow fever virus. the clones, except for jk49, recognized the same epitope on n ...	1998	9568963
wesselsbron disease virus associated with abortions in goats in botswana.		1998	9576352
mutation in a 17d-204 vaccine substrain-specific envelope protein epitope alters the pathogenesis of yellow fever virus in mice.	the heterogeneous nature of the yellow fever (yf) 17d-204 vaccine virus population was exploited in this study to isolate virus variants able to escape neutralization by the 17d-204 vaccine-specific mab 864. the conformational change on the virus surface that resulted in the loss of the mab 864-defined epitope was effected in each variant by a single amino acid mutation in the envelope (e) protein at either position e-305 or e-325. interestingly, both positions were mutated during attenuation of ...	1998	9581778
engineered resistance in aedes aegypti to a west african and a south american strain of yellow fever virus.	double subgenomic sindbis (dssin) viruses were engineered to transduce mosquito cells with antisense rna derived either from the premembrane (prm) or polymerase (ns5) coding regions of the 17d vaccine strain of yellow fever virus (yfv). aedes albopictus c6/36 cells were infected at high multiplicities of infection (moi) with each dssin virus. forty-eight hours later, the transduced cells were challenged with an moi of 0.1 of the asibi strain of yfv. at 72-hr postchallenge, the cells were assayed ...	1998	9598458
virus-encoded proteinases of the flaviviridae.		1998	9603310
[kama, a new virus (flaviviridae, flavivirus, tiulenii antigenic group), isolated from ixodes lividus ticks].	three identical strains of a new virus kama (flaviviridae, flavivirus, tyuleny antigenic group) were isolated from ixodes lividus roch, obligate parasites of riparia riparia l. the ticks were collected in june, 1990 in tatarstan on the islands in the basin of the kama river. the strains were examined under electron microscope and by serological tests (neutralization, complement fixation, hemagglutination inhibition, and indirect immunofluorescence). the virus is antigenically related but not ide ...	1998	9606874
[tick-borne encephalitis--etiopathogenesis and implications for public health in poland].	tick-borne encephalitis (tbe) belongs to infectious units being under study in poland since over 40 years: clinical, virological, immunological, epidemiological (see eg. fig. 1 of the review) observations succeeded in developing tbe map of poland, and organization of satisfactory diagnostic virological control of the disease. this article covers most important data since the early (1952-1953) expeditions to the endemic districts of poland, studies of human beings, animal reservoir, both wild and ...	1998	9608228
development of rt-pcr for turkey meningoencephalitis virus and partial sequence analysis of the ns5 gene.	turkey meningoencephalitis virus (tmev) causes paralysis and mortality in turkeys. because the classical diagnostic methods are complicated, we developed the rt-pcr as a new molecular diagnostic method. since the nucleic acid sequence of tmev is unknown, the first step in developing the rt-pcr relied on conserved sequences of viruses belonging to the flaviviridae family, in which tmev has been classified serologically. using primers from the ns5 gene, three amplification products of tmev rna wer ...	1998	9608667
[japanese encephalitis: an exceptional imported arbovirus].		1998	9779048
hepatitis g virus and related flaviviruses: pathogens or passengers?		1998	9779360
west nile virus envelope proteins: nucleotide sequence analysis of strains differing in mouse neuroinvasiveness.	several neuroinvasive and non-neuroinvasive west nile (wn) viruses were characterized by nucleotide sequencing of their envelope (e) protein regions. prolonged passage in mosquito cells caused loss of neuroinvasiveness and acquisition of an n-linked glycosylation site, which is utilized. limited passage in cell culture also caused glycosylation but not attenuation, suggesting that glycosylation may not be directly responsible for attenuation and that a second mutation (l68 --> p) may also be inv ...	1998	9780042
phylogeny of the genus flavivirus.	we undertook a comprehensive phylogenetic study to establish the genetic relationship among the viruses of the genus flavivirus and to compare the classification based on molecular phylogeny with the existing serologic method. by using a combination of quantitative definitions (bootstrap support level and the pairwise nucleotide sequence identity), the viruses could be classified into clusters, clades, and species. our phylogenetic study revealed for the first time that from the putative ancesto ...	1998	9420202