Publications

absence of double-stranded replicative forms of hcv rna in liver tissue from chronically infected patients.	the mechanism of hepatitis c virus (hcv) replication is unknown, although the classification of hcv in the flaviviridae has led to the postulation that hcv may adopt a replication strategy similar to that of the flaviviruses. to determine if hcv double-stranded replicative forms, consistent with this strategy, were present in total liver rna extracted from hcv-infected individuals, hcv-specific rna was detected by reverse transcription followed by polymerase chain reaction (rt-pcr). initially, a ...	1996	8736238
testing of a dengue 2 live-attenuated vaccine (strain 16681 pdk 53) in ten american volunteers.	a live-attenuated dengue 2 vaccine (strain 16681 pdk 53) developed at mahidol university, thailand was evaluated for safety and immunogenicity by administering 10(4) p.f.u. subcutaneously to ten flavivirus non-immune american volunteers. the vaccine was safe; there were no serious adverse reactions. eight recipients experienced no or mild side effects. one recipient reported headaches on 7 separate days. one volunteer, who had a fracture of the humerus 1 day after vaccination requiring surgical ...	1996	8744561
epidemic dengue 2 in the city of djibouti 1991-1992.	from october 1991 to february 1992, an outbreak of acute fever (in which thick blood films were negative for malaria) spread rapidly in the city of djibouti, djibouti republic, affecting all age groups and both nationals and foreigners. the estimated number of cases was 12,000. the clinical features were consistent with a non-haemorrhagic dengue-like illness. serum samples from 91 patients were analysed serologically for flavivirus infection (dengue 1-4, west nile, yellow fever, zika, banzi, and ...	1996	8758061
the new lymphotropic herpesviruses (hhv-6, hhv-7, hhv-8) and hepatitis c virus (hcv) in human lymphoproliferative diseases: an overview.	considerable evidence has been accumulating in favor of a possible involvement of viral agents in the pathogenesis of human lymphomas. the most recent proposal for a lymphoma classification, the revised european-american classification, emphasized for the first time the pathogenetic importance of two viruses, namely epstein-barr virus (ebv) and human t lymphotropic virus i (htlv-i) in the development of certain lymphoid neoplasias. however, in the last ten years new viral agents possibly related ...	1996	8767534
use of the yellow fever virus vaccine strain 17d for the study of strategies for the treatment of yellow fever virus infections.	we have employed the attenuated vaccine strain 17d of yellow fever virus (yfv) to evaluate the inhibitory effect of a selected series of compounds on yfv in vero cells. use of the vaccine strain does not require high-level microbiological containment facilities and should allow extensive screening. in addition, yfv may serve as a model for other flaviviruses including hepatitis c virus (hcv), and thus strategies for the treatment of yfv infections may apply to flavivirus infections in general. i ...	1996	8783804
activity of purified hepatitis c virus protease ns3 on peptide substrates.	the protease domain of the hepatitis c virus (hcv) protein ns3 was expressed in escherichia coli, purified to homogeneity, and shown to be active on peptides derived from the sequence of the ns4a-ns4b junction. experiments were carried out to optimize protease activity. buffer requirements included the presence of detergent, glycerol, and dithiothreitol, ph between 7.5 and 8.5, and low ionic strength. c- and n-terminal deletion experiments defined a peptide spanning from the p6 to the p4' residu ...	1996	8794305
hepatitis g virus in immunosuppressed paediatric allograft recipients.		1996	8806304
hepatitis g viral rna in italian haemophiliacs with and without hepatitis c infection.		1996	8806323
mutagenesis of the n-linked glycosylation sites of the yellow fever virus ns1 protein: effects on virus replication and mouse neurovirulence.	the flavivirus nonstructural glycoprotein ns1 is highly conserved and contains two n-linked glycosylation sites which are both utilized for addition of oligosaccharides during replication in cell culture. ns1 has been shown to contain epitopes for protective antibodies; however, its roles in virus replication and pathogenesis remain unknown. to study the function of ns1 during yellow fever virus replication, six mutant viruses which lack either one or both glycosylation sites and another one con ...	1996	8806496
generation and characterization of organ-tropism mutants of japanese encephalitis virus in vivo and in vitro.	using gamma-ray irradiation, a pair of virulent (rp-9) and attenuated (rp-2ms) variants of japanese encephalitis virus (jev) were generated from a taiwanese isolate, nt109. the two variants differed in plaque morphology, virus adsorption, and growth properties in bhk-21 cells: (i) rp-2ms produced smaller plaques than rp-9; (ii) rp-2ms adsorbed less efficiently to host cells but yielded a higher virus titer (burst size); and (iii) rp-2ms virions were mostly accumulated intracellularly, whereas rp ...	1996	8806542
characterization of the ntpase activity of japanese encephalitis virus ns3 protein.	japanese encephalitis (je) virus ns3 protein and two n-terminally truncated (delta 1-148 and delta 1-323) forms of ns3 were engineered and expressed in e. coli as fusion proteins with a histidine tag at the n terminus. the purified recombinant proteins his-ns3 and his-ns3(delta 1-148) were found to possess ntpase activity which was stimulated by single-stranded rna, whereas ns3(delta 1-323) did not. the requirements for mgcl2 and mncl2 and the salt and ph ranges necessary for optimal activity of ...	1996	8811006
correlation between elisa, hemagglutination inhibition, and neutralization tests after vaccination against tick-borne encephalitis.	the significance of igg antibody levels determined by a binding assay (elisa) was investigated as a surrogate marker for the presence of neutralizing and hemagglutination inhibiting antibodies in sera from individuals vaccinated against tick-borne encephalitis (tbe). to assess the extent of interference by flavivirus cross-reactive antibodies, sera from persons with a proven or suspected history of other flavivirus infections and/or vaccinations were also examined. an excellent and highly signif ...	1996	8825718
dominant recognition by human cd8+ cytotoxic t lymphocytes of dengue virus nonstructural proteins ns3 and ns1.2a.	a severe complication of dengue virus infection, dengue hemorrhagic fever (dhf), is hypothesized to be immunologically mediated and virus-specific cytotoxic t lymphocytes (ctls) may trigger dhf. it is also likely that dengue virus-specific ctls are important for recovery from dengue virus infections. there is little available information on the human cd8+ t cell responses to dengue viruses. memory cd8+ctl responses were analyzed to determine the diversity of the t cell response to dengue virus a ...	1996	8833919
characterization of langat virus antigenic determinants defined by monoclonal antibodies to e, ns1 and prem and identification of a protective, non-neutralizing prem-specific monoclonal antibody.	hybridomas secreting monoclonal antibodies (mab) to the tick-borne encephalitis (tbe) group virus, langat virus (lgtv), were prepared. of more than 200 mab screened, 19 antibodies, which cross-reacted with the etiologic agent of central european encephalitis, were selected for further characterization. of these mab, 15 were specific for lgtv e glycoprotein, two for the ns1 protein, and three for prem protein. the two ns1-specific mab and two of the e-specific mab reacted with all six of the othe ...	1996	8864202
hepatitis g virus: identification and prevalence.	a new flavivirus, provisionally designated as hepatitis g virus, has recently been identified. its genomic organization is similar to that of the hepatitis c virus (hcv) with which it has only 25% nucleotide homology. the virus is transmissible by blood transfusion, by exposure to blood products or by intravenous drug use. concurrent infection with hepatitis b virus and hcv is common and persistent viraemia has been documented, in many cases in the absence of transaminase elevations.	1996	8879706
identification of peptides mimicking the antigenicity and immunogenicity of conformational epitopes on japanese encephalitis virus protein using synthetic peptide libraries.	monoclonal antibodies (mabs) n.03 and n.08 that recognize conformational epitopes on the prm protein of japanese encephalitis virus (jev) were analyzed to identify their peptide ligands by using a novel approach that combined two different synthetic peptide libraries. immunoscreening of a library containing 20(5) sequences of pentapeptides revealed that the ligands for n.03 and n.08 had motif sequences, (y/w/f)gg(i/l/m) and (n/q)wy(d/e), respectively. to select higher-affinity ligands, we synthe ...	1996	8882934
expression and purification of the seven nonstructural proteins of the flavivirus kunjin in the e. coli and the baculovirus expression systems.	all seven nonstructural (ns) proteins of the flavivirus kunjin (kun) ranging from ns1 to ns5 were expressed either alone or as fusion proteins with glutathione-s-transferase (gst). high level expression of recombinant proteins was achieved in spodoptera frugiperda (sf9) cells using the baculovirus expression system in contrast to the low level of expression in e. coli. the order of the level of expression of the recombinant fusion proteins per 4 x 10(7) sf9 cells was: gst-ns5 (yields approximate ...	1996	8882936
structural requirements for low-ph-induced rearrangements in the envelope glycoprotein of tick-borne encephalitis virus.	the exposure of the flavivirus tick-borne encephalitis (tbe) virus to an acidic ph is necessary for virus-induced membrane fusion and leads to a quantitative and irreversible conversion of the envelope protein e dimers to trimers. to study the structural requirements for this oligomeric rearrangement, the effect of low-ph treatment on the oligomeric state of different isolated forms of protein e was investigated. full-length e dimers obtained by solubilization of virus with the detergent triton ...	1996	8892942
infection with hepatitis g virus among recipients of plasma products.	hepatitis g virus (hgv or gbv-c) is a newly discovered human flavivirus distantly related to hepatitis c virus (hcv). little information is available on its natural history or routes of transmission, although it can be transmitted parenterally. we investigated the prevalence of persistent infection of hgv and hcv in patients exposed to non-virus-inactivated pooled blood products associated with transmission of hcv.	1996	8918279
enhancement of hepatitis c virus ns3 proteinase activity by association with ns4a-specific synthetic peptides: identification of sequence and critical residues of ns4a for the cofactor activity.	the ns3 proteinase of hepatitis c virus utilizes ns4a as a cofactor for cleavages at four sites (3/4a, 4a/4b, 4b/5a, and 5a/5b) in the nonstructural region of the viral polyprotein. to characterize ns4a for its role in modulating the ns3 proteinase activity at various cleavage sites, synthetic peptides spanning various parts of ns4a were synthesized and tested in a cell-free trans-cleavage reaction using purified ns3 proteinase domain and polyprotein substrates. the ns3 proteinase domain was exp ...	1996	8918919
characterization of rna synthesis during a one-step growth curve and of the replication mechanism of bovine viral diarrhoea virus.	the noncytopathic australian bovine viral diarrhoea virus (bvdv) trangie isolate was used to establish a one-step growth curve and to investigate previously uncharacterized aspects of pestivirus replication. the eclipse phase was found to be approximately 8 to 10 h and the first appearance of viral antigen assayed by immunofluorescence occurred around 6 h post-infection (p.i.). both positive- and negative-sense virus rnas were first detected at 4 h p.i. by northern blot hybridization using stran ...	1996	8922466
diagnosis of tick-borne encephalitis: evaluation of sera with borderline titers with the tbe-elisa.	tick-borne encephalitis (tbe) is a member of the flaviviridae family. strong cross-reactions can occur between members of this family, so that it may be difficult to diagnose specific flavivirus infections, especially when tests with frequent cross-reactions e.g. elisa tests are used. we tested 238 sera with borderline titers for tbe using the indirect immunofluorescence or neutralization test for other flaviviruses (yellow fever, dengue, west nile) to detect cross-reactions due to other flavivi ...	1996	8923059
[the risk of urban yellow fever outbreaks in brazil by dengue vectors. aedes aegypti and aedes albopictus].	urban yellow fever (yf) epidemics have disappeared from brazil since about 50 years, but a selvatic cycle still exist. in many states, cases are more or less numerous each year. ae. aegypti was eradicated in 1954, re-appeared temporarily in 1967, and then definitively in 1976-1977. ae. aegypti is a vector of yellow few (yf), but also of dengue, whose first cases were reported in 1982. today, dengue is endemic in many regions. a second flavivirus vector, aedes albopictus is present since about te ...	1996	8924767
[effectiveness of the interferon inducers ridostin and camedon in prevention and treatment of experimental alpha- and flavivirus infections].	antiviral activity of rybamidil (virasol) and interferon inducers ridostine and camedone developed in russia and introduced in practical medicine has been studied in mice with experimentally induced arboviral infections, flavivirus (tick-borne encephalitis-tbe, and yellow fever-yf) and alphavirus ones (western and eastern equine encephalomyelitis-wee and eee). rybamidil injected subcutaneously proved to be ineffective both for prevention and treatment of these infections. early interferon induce ...	1996	8928508
flavivirus-induced up-regulation of mhc class i antigens; implications for the induction of cd8+ t-cell-mediated autoimmunity.	infection of a wide variety of cells of human, mouse and other species' origin by flaviviruses such as wnv, yf, den, mve, kun and je, increases the cell-surface expression of mhc class i. this mhc class i up-regulation is not due to increased mhc class i synthesis per se, but the result of increased peptide availability in the er for mhc class i assembly. this is most likely due to the interaction of the viral polyprotein with the er membrane during viral replication. flavivirus infection can ov ...	1996	8930665
the immunology of eta-1/osteopontin.	the cytokine eta-1/osteopontin is secreted by activated macrophages and may constitute the most abundant molecule secreted by activated t-lymphocytes. it causes macrophages to migrate and suppress production of reactive oxygen species. it enhances generation of immunoglobulins or proliferation of b-lymphocytes. its biochemical characteristics suggest that eta-1/osteopontin may be the t-lymphocyte suppressor factor. the apparently conflicting effects on individual immune functions may reflect hom ...	1996	8971479
evaluation of monoclonal antibodies for generic detection of flaviviruses by elisa.	three monoclonal antibodies (mabs) specific for the envelope (e) protein of flaviviruses were evaluated for use in an antigen capture elisa. three combinations of mabs and a combination of polyclonal antibodies (pabs) were evaluated in antigen capture elisas for their ability to detect 18 flaviviruses. the mab elisas detected 50% of flavivirus antigens with a sensitivity between 1 and 9 x 10(4)/ng viral protein/ml, however, none of the elisas evaluated proved to be useful for generic detection o ...	1996	9002072
gbv-c/hgv is not the major cause of autoimmune hepatitis.	recently, gbv-c and hgv-two isolates of the same new flavivirus-were identified in serum samples of patients with indeterminate hepatitis and posttransfusion hepatitis, respectively. the pathogenic relevance of these viruses is still uncertain. as viral infections are presumed to trigger autoimmune processes, we investigated gbv-c in autoimmune hepatitis as well as in cryptogenic hepatitis, and compared the prevalences to patients with chronic viral hepatitis and those of blood donors. we found ...	1996	9007730
[recent data on the epidemiology of japanese encephalitis].	japanese encephalitis is an arbovirosis the incidence and geographic distribution of which are increasing in rural areas of tropical and temperate asia. a total of about 45,000 to 50,000 clinical cases occur annually. the flavivirus responsible for the disease shows birds as usual hosts, and culex mosquitoes as vectors. after a first amplification cycle in birds, the virus can be transmitted to domestic pigs, then to man. this scheme, however, shows large variations in the different regions, acc ...	1996	8991613
hepatitis g virus/gb virus c in brazil. preliminary report.	hepatitis g virus/gb virus c is a novel flavivirus recently detected in hepatitis non a-e cases. in this study, the presence of this virus in chronic non-b, non-c hepatitis patients was evaluated using gbv-c specific pcr and this virus was detected in one out of thirteen patients. this patient has presented a severe liver failure, has lived for a long time in the western amazon basin and no other cause for this clinical picture was reported. the impact of the discovery of this new agent is still ...	1996	9163994
medical microbiology	at least 27 alphaviruses and 68 flaviviruses have been recognized, approximately one-third of which are medically important human pathogens. they vary widely in their basic ecology; each virus occupies a distinct ecologic niche, often with restricted geographic and biologic distribution. as shown in tables 54-1 and 54-2, alphaviruses and flaviviruses can cause various syndromes, ranging from benign febrile illnesses to severe system ...	1996	21413253
genotype determination of three dengue type 2 virus strains from myanmar by sequencing e/nsi gene junction.	genotype of three dengue-2 virus strains from myanmar was determined as genotype ii by sequencing 240 nucleotide long fragment across the e/ns1 gene junction by the primer extension dideoxy chain termination method, applying direct sequencing of the pcr product. these strains were isolated from a dengue shock syndrome (dss) patient and two patients with dengue hemorrhagic fever (dhf) grade 1, in yangon (rangoon), myanmar (burma), in 1987. sequence homology of all three strains were highest (96%) ...	1995	9139372
generation and characterization of japanese encephalitis virus specific monoclonal antibodies.	monoclonal antibodies (moabs) specifically against japanese encephalitis virus (jev) were generated by fusion of immunized mouse spleen cells with ns-1 myeloma cells. nakayama-nih (na) and three taiwan local strains of jev, i.e., tl isolated from a patient's brain in 1965, nt109 (je7) isolated from cx. tritaeniorhynchus in 1985, and rp9, a plaque purified clone of nt109, were used in the immunization. the specificities of moabs were determined by immunoprecipitation and western blotting, using j ...	1995	9774991
molecular epidemiology and evolution of mosquito-borne flaviviruses and alphaviruses enzootic in australia.	three distinct patterns in the molecular epidemiology and evolution are evident among the alphaviruses and flaviviruses enzootic in australia. one pattern, exemplified by mve and kun viruses, is of a single genetic type evolving slowly and uniformly in geographically widely separated regions of australia with no evidence of independent divergence. the second pattern, exemplified by rr virus, is of separate genotypes evolving in different geographic regions with significant nucleotide divergence ...	1995	8828149
antigenic similarity of central european encephalitis and louping-ill viruses.	twenty isolates of central european encephalitis (cee) virus were compared with 20 isolates of louping-ill (li) virus in indirect immunofluorescence test (iift), using a panel of 17 monoclonal antibodies (moabs) prepared against the prototype li virus. three asian members of the tick-borne encephalitis (tbe) complex were also included in the comparison: turkish sheep encephalitis (tse), russian spring-summer encephalitis (rsse) and langat (lgt) viruses. antigenic relationships of the viruses wer ...	1995	8722293
hepatitis c virus as a lymphotropic agent: evidence and pathogenetic implications.	hepatitis c virus has been proven to be the major cause of nanb hepatitis, cirrhosis and hepatocellular carcinoma worldwide. based on the genome similarities between hcv and flavivirus or pestivirus, this agent has been included within the family flaviviridae as a separate genus. among the analogies between hcv and the other members of the same family there is the possibility of infecting blood cells. in particular, significant evidence obtained through studies performed in vivo and in vitro sup ...	1995	8730474
the diagnosis of wesselsbron disease in a new-born lamb by immunohistochemical staining of viral antigen.	wesselsbron disease (wsl) was diagnosed in a 2-d-old lamb on a farm in the north-eastern free state province where a few abortions and neonatal deaths occurred in sheep in april 1994. the liver of the lamb was slightly swollen and orange-brown and, microscopically, it revealed single or small groups of necrotic hepatocytes that were randomly scattered throughout the lobules. other histopathologic hepatic lesions included the presence of acidophilic bodies, intranuclear inclusion bodies in a few ...	1995	8600439
nucleotide sequence of the protein e gene of the tick-borne encephalitis virus strain 595 isolated in slovakia.	tick-borne encephalitis (tbe) virus, strain 595 was isolated from ixodes ricinus ticks in southern slovakia. a part of the protein e gene was sequenced and compared with the prototype strain neudorfl. seventeen silent mutations and two amino acid changes (ile-->val, residue 167; asn-->thr, residue 366) were found. the nucleotide homology in the sequenced part of protein e gene of the strain 595 and the prototype strain neudorfl is 98.6%. these findings indicate that the strain 595 is closely rel ...	1995	8578999
viral envelope glycoproteins swing into action.	analysis of tick-borne encephalitis virus e protein reveals considerable structural diversity in the glycoproteins that clothe enveloped viruses and hints at the conformational gyrations in this molecule that lead to viral fusion.	1995	8591041
persistence and transmission of tick-borne viruses: ixodes ricinus and louping-ill virus in red grouse populations.	the population dynamics of tick-borne disease agents and in particular the mechanisms which influence their persistence are examined with reference to the flavivirus that causes louping-ill in red grouse and sheep. pockets of infection cause heavy mortality and the infection probably persists as a consequence of immigration of susceptible hosts. seroprevalence is positively associated with temporal variations in vectors per host, although variation between areas is associated with the abundance ...	1995	8632924
expression of the japanese encephalitis virus ns3 and ns2b proteins as glutathione s-transferase fusions.	flaviviruses generate their structural and nonstructural proteins by proteolytic processing of a single large polyprotein precursor. these proteolytic events are brought about both by host cell signalase and a virally encoded protease. the virally encoded proteolytic activity has been shown to reside within the nonstructural protein 3 (ns3) and requires the product of the nonstructural 2b (ns2b) gene. in order to obtain sufficient quantities of pure ns2b and ns3 proteins for kinetic analysis, we ...	1995	8714204
[thymus hormones in the treatment and prevention of flavivirus infection under experimental conditions].	the evaluation and selection of the preparations of thymic hormones for the treatment and prophylaxis of acute tick-borne encephalitis (tbe) caused by far eastern tbe virus strains have been carried out on mice under different experimental conditions. these virus strains, highly and faintly virulent with respect to noninbred mice, produce a different modulating effect of the immune responsiveness of the host, respectively suppressing or simulating immune response to sheep red blood cells. a high ...	1995	8525716
purification and renaturation of japanese encephalitis virus nonstructural glycoprotein ns1 overproduced by insect cells.	the nonstructural protein ns1 of japanese encephalitis virus is a major immunogen produced during flavivirus infection. however, the function of this protein has not been identified. to analyze its biochemical properties and evaluate its potential activity in the virus life cycle, the protein was produced in spodoptera frugiperda insect cells (sf9), using a recombinant baculovirus, and purified. as described previously by m. flamand, v. deubel, and m. girard (1992, virology 191, 826-836), a smal ...	1995	8527939
australian-indonesian collaboration in veterinary arbovirology--a review.	australian-indonesian collaboration in veterinary development programs has led to significant advances in the study of arboviruses. this paper reviews the resulting knowledge of arboviral infections of livestock in indonesia. the first recognized arboviral disease of animals in indonesia was bovine ephemeral fever. serology indicates that the virus is widespread, as are related rhabdoviruses. local sheep appear resistant to bluetongue disease, but imported sheep have suffered mortalities. blueto ...	1995	8545953
australian x disease, murray valley encephalitis and the french connection.	epidemics of a severe encephalitis occurred in eastern australia between 1917 and 1925, in which over 280 cases were reported with a fatality rate of 68%. the disease had not been described previously and was called australian x disease. the next epidemic occurred in south-east australia in the summer of 1950-51. the disease was given its name of murray valley encephalitis as this was the area from which most cases were reported. a virus was isolated by eric french in victoria, and about the sam ...	1995	8545982
infectious transcripts of tick-borne encephalitis virus, generated in days by rt-pcr.	construction of infectious clones of flaviviruses can be problematic owing to instability, toxicity, and recombination events occurring while cloning cdna in the bacterial vectors. to overcome these difficulties we have devised a rapid and simple method for producing an infectious genetically engineered tick-borne encephalitis virus in less than 10 days using viral rna from an unpurified virus suspension. the experimental protocol utilized the high fidelity reverse transcription-polymerase chain ...	1995	8553563
[tick-transmitted arbovirus in maghreb].	the problem of arbovirus infections in maghreb has been relatively neglected in the pst in spite of a rich diversity of biotopes, the presence of potential reservoirs and vectors, and their position on the flight path of the palearctic-african bird migration systems, western branch. moreover, west nile virus has been isolated from southern algeria since 1968. from 1979 to 1989, ticks were collected from wild birds, pigeons, bats, rodents, poultry, camels, wild boars, domestic mammals and man, an ...	1995	8555772
evidence that flavivirus ns1-ns2a cleavage is mediated by a membrane-bound host protease in the endoplasmic reticulum.	previous deletion mutagenesis studies have shown that the flavivirus ns1-ns2a clevage requires the eight c-terminal residues of ns1, constituting the cleavage recognition sequence, and sequences in ns2a far downstream of the cleavage site. we now demonstrate that replacement of all of ns1 upstream of the cleavage recognition sequence with prm sequences still allows cleavage in vivo. thus, other than the eight c-terminal residues, ns1 is dispensable for ns1-ns2a cleavage. however, deletion of the ...	1995	7474145
detection of the gbv-c hepatitis virus genome in serum from patients with fulminant hepatitis of unknown aetiology.	hepatitis viruses a, b, c, d, and e have not accounted for all cases of hepatitis, hence "non a-e" agent(s) might be implicated. a set of new viruses (gbv-a, -b, and -c) whose genomes have been sequenced, are being investigated as possible causes of non a-e hepatitis. we investigated six cases of fulminant hepatitis of unknown aetiology for the presence of gbv-c genome in their serum, and three showed positive signals by semi-nested pcr using primers derived from the ns3/helicase region. nucleot ...	1995	7475605
the flavivirus 3'-noncoding region: extensive size heterogeneity independent of evolutionary relationships among strains of tick-borne encephalitis virus.	the sequences of the 3'-noncoding regions (ncr) of 12 strains of tick-borne encephalitis (tbe) virus were analyzed and found to vary in length from 350 to approximately 750 nucleotides. the size heterogeneity is restricted to a variable region following the stop codon, whereas the most 3'-terminal 350 nucleotides form a highly conserved core element containing several potentially important sequence motifs and secondary structure elements. a homoadenosine tract previously thought to form the 3'-t ...	1995	7483260
complex formation between the ns3 serine-type proteinase of the hepatitis c virus and ns4a and its importance for polyprotein maturation.	processing of the hepatitis c virus polyprotein is mediated by host cell signalases and at least two virally encoded proteinases. of these, the serine-type proteinase encompassing the amino-terminal one-third of ns3 is responsible for cleavage at the four sites carboxy terminal of ns3. the activity of this proteinase is modulated by ns4a, a 54-amino-acid polyprotein cleavage product essential for processing at the ns3/4a, ns4a/4b, and ns4b/5a sites and enhancing cleavage efficiency between ns5a ...	1995	7494258
posttranslational signal peptidase cleavage at the flavivirus c-prm junction in vitro.	we have investigated the cleavages at the flavivirus capsid-prm protein junction in vitro. when expressed in the absence of the flavivirus proteinase, capsid and prm, which are separated by an internal signal sequence, exist as a membrane-spanning precursor protein. here we show the induction of posttranslational signal peptidase cleavage of prm by trypsin cleavage of a cytoplasmic region of this precursor protein.	1995	7494334
preparation of recombinant baculovirus by transfection of a ligated cdna fragment without prior plasmid amplification in e. coli.		1995	7495544
oligomeric rearrangement of tick-borne encephalitis virus envelope proteins induced by an acidic ph.	the flavivirus envelope protein e undergoes irreversible conformational changes at a mildly acidic ph which are believed to be necessary for membrane fusion in endosomes. in this study we used a combination of chemical cross-linking and sedimentation analysis to show that the envelope proteins of the flavivirus tick-borne encephalitis virus also change their oligomeric structure when exposed to a mildly acidic environment. under neutral or slightly alkaline conditions, protein e on the surface o ...	1995	7529335
dengue virus-specific, hla-b35-restricted, human cd8+ cytotoxic t lymphocyte (ctl) clones. recognition of ns3 amino acids 500 to 508 by ctl clones of two different serotype specificities.	dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas of the world. we analyzed dengue virus-specific cd8+ cd4- ctl at the clonal level to further understand the role of cd8+ ctl in dengue virus infections. dengue virus-specific cd8+ ctl clones were established from lymphocytes of a dengue 4-immune adult. three patterns of dengue serotype specificities were identified: 1) specific for dengue 4, 2) cross-reactive for dengue 2 and dengue 4 (subcompl ...	1995	7529799
tick-borne encephalitis virus envelope protein e-specific monoclonal antibodies for the study of low ph-induced conformational changes and immature virions.	a set of ten monoconal antibodies (mabs) specific for the tick-borne encephalitis (tbe) virus envelope protein e were prepared and characterized with respect to their functional activities, the location of their binding sites on protein e and the involvement of their epitopes in acid ph-induced conformational changes and interactions with the precursor to the membrane protein (prm) in immature virions. the majority of these mabs mapped to the previously defined antigenic domain a. all of the mab ...	1995	7535997
lack of augmenting effect of interferon-gamma on dengue virus multiplication in human peripheral blood monocytes.	the effect of interferon-gamma (ifn-gamma) on dengue virus multiplication in human peripheral blood monocytes was investigated. enriched monocytes were treated with ifn-gamma and then infected with dengue virus type 2 either directly or in the presence of optimal infection-enhancing levels of antibodies. pretreatment of monocytes from dengue-immune donors with 100 iu/ml of ifn-gamma caused 12- to 97-fold and 13- to 137-fold reduction of virus yields at 24 hr after infection in the absence and pr ...	1995	7536230
up-regulation of mhc class i by flavivirus-induced peptide translocation into the endoplasmic reticulum.	flavivirus infection of mammalian cells increases the cell surface expression of major histocompatibility complex (mhc) class i molecules, the recognition elements for cytotoxic t cells. here, we show that the mechanism for flavivirus-induced up-regulation of class i mhc involves an increase in peptide supply to the endoplasmic reticulum. flavivirus-mediated peptide supply for mhc class i assembly is independent of the peptide transporters for class i antigen presentation, since infection of cla ...	1995	7544229
a single nine-amino acid peptide induces virus-specific, cd8+ human cytotoxic t lymphocyte clones of heterogeneous serotype specificities.	it is generally accepted that virus-specific cd8+ cytotoxic t lymphocytes (ctls) recognize nine-amino acid peptides in conjunction with hla class i molecules. we recently reported that dengue virus-specific cd8+ ctls of two different serotype specificities, which were established by stimulation with dengue virus, recognize a single nine-amino acid peptide of the nonstructural protein ns3 of dengue virus type 4 (d4v) in an hla-b35-restricted fashion. to further analyze the relationships between t ...	1995	7544398
flavivirus-cross-reactive, hla-dr15-restricted epitope on ns3 recognized by human cd4+ cd8- cytotoxic t lymphocyte clones.	the role of flavivirus-cross-reactive t lymphocytes in recovery from and pathogenesis of flavivirus infections is not known. in the present paper, we have defined a flavivirus-cross-reactive epitope recognized by two cd4+ cd8- cytotoxic t lymphocyte (ctl) clones, jk4 and jk43. the t cell clones were established from the peripheral blood t lymphocytes of a dengue-4-immune donor, using a limiting-dilution method with dengue-4 antigen. these two t cell clones were cross-reactive for dengue virus ty ...	1995	7561761
nucleotide sequence of the ns5 gene of banzi virus: comparison with other flaviviruses.	banzi is a mosquito borne flavivirus which belongs to the uganda s serocomplex. no nucleotide sequence data have previously been reported from any virus of this serocomplex. we have determined the nucleotide sequence of the ns5 gene from banzi virus and the predicted amino acid sequence was elucidated. previously identified conserved rna polymerase, methyltransferase and flavivirus ns5 amino acid motifs were present in the banzi virus ns5 protein. these data add to the evidence for the functiona ...	1995	7561771
low resolution mapping around the flavivirus resistance locus (flv) on mouse chromosome 5.	although the phenomenon of innate resistance to flaviviruses in mice was recognized many years ago, it was only recently that the genetic locus (flv) controlling this resistance was mapped to mouse chromosome (chr) 5. here we report the fine mapping of the flv locus, using 12 microsatellite markers which have recently been developed for mouse chr 5. the new markers were genotyped in 325 backcross mice of both (c3h/hej x c3h/rv)f1 x c3h/hej and (balb/c x c3h/rv)f1 x balb/c backgrounds, relative t ...	1995	7579886
wesselsbron virus antibody in domestic animals in nigeria: retrospective and prospective studies.	retrospective and prospective serological surveys to determine the prevalence of wesslsbron (wsl) virus infections in animal populations were carried out in different vegetational zones in nigeria. sera from 1,492 animals comprising 292 camels, 81 horses, 4 donkeys, 320 cattle, 235 sheep, 260 goats, 114 pigs, 101 dogs and 85 domestic fowls were assayed by haemagglutination-inhibition (hi) test for presence of antibodies to wsl virus and other flavivirus antigens: yellow fever (yf), potiskum (pot ...	1995	7603342
molecular and serologic analysis in the transmission of the gb hepatitis agents.	two flavivirus-like genomes have recently been cloned from infectious tamarin (saguinus labiatus) serum, derived from the human viral hepatitis gb strain, which is known to induce hepatitis in tamarins. in order to study the natural history of gb infections, further transmission studies were carried out in tamarins. reverse-transcription-polymerase chain reaction and enzyme-linked immunosorbant assays were developed for the detection of rna and antibodies associated with the two agents, gb virus ...	1995	7623012
bhk cell proteins that bind to the 3' stem-loop structure of the west nile virus genome rna.	the first 83 3' nucleotides of the genome rna of the flavivirus west nile encephalitis virus (wnv) form a stable stem-loop (sl) structure which is followed in the genome by a smaller sl. these 3' structures are highly conserved among divergent flaviviruses, suggesting that they may function as cis-acting signals for rna replication and as such might specifically bind to cellular or viral proteins. cellular proteins from uninfected and wnv-infected bhk-21 s100 cytoplasmic extracts formed three di ...	1995	7637011
synthesis and secretion of recombinant tick-borne encephalitis virus protein e in soluble and particulate form.	a quantitative study was performed to investigate the requirements for secretion of recombinant soluble and particulate forms of the envelope glycoprotein e of tick-borne encephalitis (tbe) virus. full-length e and a carboxy terminally truncated anchor-free form were expressed in cos cells in the presence and absence of prm, the precursor of the viral membrane protein m. formation of a heteromeric complex with prm was found to be necessary for efficient secretion of both forms of e, whereas only ...	1995	7637027
association between ns3 and ns5 proteins of dengue virus type 2 in the putative rna replicase is linked to differential phosphorylation of ns5.	dengue virus type 2, a member of the family flaviviridae, encodes a single polyprotein precursor consisting of 3391 amino acids residues that is processed to at least 10 mature proteins by host and viral proteases. the ns3 protein contains a domain commonly found in cellular serine proteinases that in cooperation with ns2b is involved in polyprotein processing. in addition, ns3 and ns5 proteins contain conserved motifs found in several rna helicases and rna-dependent rna polymerases, respectivel ...	1995	7642575
a novel complex formed between the flavivirus e and ns1 proteins: analysis of its structure and function.	we examined the structural features and functional significance of a novel complex which forms between the envelope (e) protein and nonstructural protein ns1 of murray valley encephalitis (mve) virus. western blot analysis of virus-infected c6/36 cell lysates revealed that the undenatured form of this e-ns1 complex was a heat-sensitive e-(ns1 dimer) complex. furthermore, the e-ns1 complex was observed in cells infected with kunjin, japanese encephalitis, west-nile and kokobera viruses which indi ...	1995	7646339
epitope mapping of dengue 1 virus e glycoprotein using monoclonal antibodies.	ten monoclonal antibodies (mabs) were raised against dengue 1 (den 1, hawaii) virus e glycoprotein. specificity of the mabs was tested by elisa and immunofluorescence. eight were den 1 type-specific, one was den group-reactive (dgr) and one was flavivirus cross-reactive (fcr). two of these type specific mabs exhibited haemagglutination-inhibition (hi) and neutralized (n) den 1 virus in vivo (hs). these two mabs showed 100% protection against a challenge of 100 ld50 of den 1 virus in adult swiss ...	1995	7646356
viral infection of macrophages profoundly alters requirements for induction of nitric oxide synthesis.	activated mouse macrophages can produce high levels of nitric oxide, an antimicrobial effector molecule recently also implicated in antiviral defense. as viral infection may alter macrophage functions, nitric oxide production was investigated in murine macrophages infected with a flavivirus, tick-borne encephalitis virus. infected macrophages produced high levels of nitric oxide upon stimulation with lipopolysaccharide without priming, while in control macrophages induction of nitric oxide produ ...	1995	7676626
identification of two flavivirus-like genomes in the gb hepatitis agent.	a subtractive pcr methodology known as representational difference analysis was used to clone specific nucleotide sequences present in the infectious plasma from a tamarin infected with the gb hepatitis agent. eleven unique clones were identified, seven of which were examined extensively. all seven clones appeared to be derived from sequences exogenous to the genomes of humans, tamarins, saccharomyces cerevisiae, and escherichia coli. in addition, sequences from these clones were not detected in ...	1995	7724574
japanese encephalitis virus nonstructural protein ns3 has rna binding and atpase activities.	sequence data suggest that japanese encephalitis virus (jev) protein ns3 is a multifunctional protein with sequence motifs characteristic of a protease and a helicase. to examine the functions of jev-ns3, a fusion protein of ns3 in escherichia coli was generated. analysis by western blot using monospecific rabbit antisera generated against the fusion protein (anti-mbjen3) showed that ns3 was localized in the membrane fraction of jev-infected cells and the particulate fraction of bacteria extract ...	1995	7732656
rapid, single-step rt-pcr typing of dengue viruses using five ns3 gene primers.	in order to detect and type dengue viruses in serum specimens, four type-specific downstream primers were designed for use with a consensus upstream primer in a reverse transcription and polymerase chain reaction (rt-pcr) assay. rt-pcr using these five primers amplified ns3 gene fragments of diagnostic sizes of 169, 362, 265 and 426 base pairs for dengue virus types 1, 2, 3 and 4, respectively, but not for japanese encephalitis, kunjin and yellow fever viruses. the conventional two-step rt-pcr p ...	1995	7738139
immunodominant epitopes on the ns1 protein of mve and kun viruses serve as targets for a blocking elisa to detect virus-specific antibodies in sentinel animal serum.	two mosquito-borne flaviviruses, murray valley encephalitis (mve) and kunjin (kun), are the aetiological agents of australian encephalitis. mve causes a severe and potentially fatal form of the disease while kun is responsible for only a few relatively mild cases. therefore it is important that serological tests used in flavivirus surveillance differentiate between infections with these two viruses. however, this has been hampered in the past by the close antigenic relationships between flavivir ...	1995	7738140
isolation of wesselsbron virus from ostriches.		1995	7740726
a community-based study of subclinical flavivirus infections in children in an area of tamil nadu, india, where japanese encephalitis is endemic.	a characteristic feature of the epidemiology of japanese encephalitis (je) is the occurrence of a large number of subclinical infections. the reporting of only overt cases underestimates the total level of virus transmission, a knowledge of which is essential for the evolution of control strategies. we carried out a 3-year prospective serological study between 1989 and 1991 in a primary health centre in tamil nadu where je is endemic. each year paired specimens, taken before and after the transm ...	1995	7743596
the filovirus enigma.		1995	7746050
the virus causing encephalomyelitis in sheep in spain: a new member of the tick-borne encephalitis group.	the nucleotide and deduced primary amino acid sequence of the envelope gene of two virus isolates from the brains of spanish sheep with encephalomyelitis, were determined and compared with those of other flaviviruses. the amino acid alignments showed that the spanish viruses shared 95 to 96 per cent homology with the envelope protein of louping ill virus and western european tick-borne encephalitis virus. in comparison, the maximum variation in amino acid identities among strains of louping ill ...	1995	7709053
[meningoencephalo-myeloradiculitis due to flavivirus: bi-brachial paralysis and respiratory insufficiency].	3 patients developed rapid onset of fever and nuchal stiffness. paresis of brachial muscles occurred within 4 days and all patients had respiratory failure that needed mechanical ventilation. at the peak of the disease there were bilateral asymmetrical severe atrophy of brachial, shoulder and neck muscles, cranial nerve pareses and absent or weak deep reflexes in the upper extremities. csf analyses showed sterile lymphocytic pleocytosis. in 2 cases the patients suffered a tick bite in switzerlan ...	1995	7709179
early induction of interferon-independent virus-specific icam-1 (cd54) expression by flavivirus in quiescent but not proliferating fibroblasts--implications for virus-host interactions.	west nile virus (wnv) infection of human embryonic fibroblasts can induce expression of icam-1 by two distinct mechanisms. an early and direct mechanism occurs within 2 hr of virus infection which is cytokine independent, and an indirect mechanism occurs within 24 hr of virus infection and is regulated by the release of ifn-type 1. virus-inactivated, conditioned supernatants removed from wnv-infected fibroblast cultures at 4 hr did not alter icam-1 expression on fresh, untreated fibroblasts, whe ...	1995	7747416
adherence status regulates the primary cellular activation responses to the flavivirus west nile.	increases in cell-surface intercellular adhesion molecule-1 (icam-1; cd54) and major histocompatibility complex antigen class i (mhc-i) and class ii (mhc-ii) expression during flavivirus infection of murine macrophages was strongly dependent on adherence status. cd54 and mhc expression was significantly increased during infection with the flavivirus west nile (wnv) on adherent, but not on non-adherent, macrophages. in contrast, increased cd54 and mhc-i expression was induced by interferon-gamma ...	1995	7751002
the envelope glycoprotein from tick-borne encephalitis virus at 2 a resolution.	the crystallographically determined structure of a soluble fragment from the major envelope protein of a flavivirus reveals an unusual architecture. the flat, elongated dimer extends in a direction that would be parallel to the viral membrane. residues that influence binding of monoclonal antibodies lie on the outward-facing surface of the protein. the clustering of mutations that affect virulence in various flaviviruses indicates a possible receptor binding site and, together with other mutatio ...	1995	7753193
complete nucleotide sequence of yellow fever virus vaccine strains 17dd and 17d-213.	the complete nucleotide sequence of the genome from two yellow fever (yf) virus vaccine strains, 17dd and 17d-213, has been determined. comparison of these sequences with those of other yf viruses including the parental virulent asibi strain allowed the identification of 48 nucleotide sequence differences which are common to all 17d substrains. this is a significant reduction from the 67 nucleotide changes originally reported as being 17d-specific and potentially related to viral attenuation. th ...	1995	7754673
immunisation against japanese encephalitis.		1995	7760642
alphavirus and flavivirus glycoproteins: structures and functions.		1995	7774004
analysis of flavivirus envelope proteins reveals variable domains that reflect their antigenicity and may determine their pathogenesis.	studies on the molecular basis of flavivirus neutralisation, attenuation and tropism indicate that amino acid substitutions, in different parts of the envelope gene, may be responsible for the altered phenotypes. however, the association of particular substitutions with individual characteristics has proven difficult. comparative analysis of all known tick-borne flavivirus envelope proteins through sequence alignment and a sliding window, reveals clusters of amino acid variation distributed thro ...	1995	7785318
an arbovirus cline across the northern hemisphere.	the mode and tempo of arbovirus evolution and dispersal can help to explain the dynamics of pandemics, viral outbreaks, and emerging viruses. by comparing nucleotide and deduced amino acid sequences of their envelope proteins, we describe the continuous distribution of the tick-borne encephalitis (tbe) complex viruses, the most important flaviviruses in europe, across major geographical areas and the conditions under which mutations occur. the analyses reveal a correlation between the geographic ...	1995	7793067
intracellular interference of tick-borne flavivirus infection by using a single-chain antibody fragment delivered by recombinant sindbis virus.	a single-chain antibody fragment that identifies a neutralizing epitope on the envelope protein of louping ill and some other tick-borne flaviviruses was previously expressed in soluble form from bacteria and shown to be functionally active in vitro. to see whether or not the single-chain antibody could bind and inactivate infectious virus in vivo, we have used recombinant sindbis virus as a delivery vehicle for intracellular expression of the antibody fragment. the variable genes and interchain ...	1995	7815482
hepatitis c virus-encoded nonstructural protein ns4a has versatile functions in viral protein processing.	a transient protein expression system in cos-1 cells was used to study the role of hepatitis c virus (hcv)-encoded ns4a protein on hcv nonstructural polyprotein processing. by analyzing the protein expression and processing of a deletion mutant polypeptide, ns delta 4a, which encodes the entire putative hcv nonstructural polyprotein except the region encoding ns4a, the versatile functions of ns4a were revealed. most of the ns3 processed from ns delta 4a was localized in the cytosol fraction and ...	1995	7853491
mutagenesis of the yellow fever virus ns2b/3 cleavage site: determinants of cleavage site specificity and effects on polyprotein processing and viral replication.	the determinants of cleavage site specificity of the yellow fever virus (yf) ns3 proteinase for its 2b/3 cleavage site have been studied by using site-directed mutagenesis. mutations at residues within the garr decreases s sequence were tested for effects on cis cleavage of an ns2b-3(181) polyprotein during cell-free translation. at the p1 position, only the conservative substitution r-->k exhibited significant levels of cleavage. conservative and nonconservative substitutions were tolerated at ...	1995	7853494
an amino-terminal domain of the hepatitis c virus ns3 protease is essential for interaction with ns4a.	hepatitis c virus (hcv) genomic rna is translated into a large polyprotein that is processed into structural and nonstructural proteins. processing at the n termini of several nonstructural proteins requires sequences contained in both ns3 and ns4a. ns3 contains a serine protease, whereas the function of ns4a in proteolysis is yet to be determined. by using the vaccinia virus-t7 hybrid expression system to transiently express hcv polypeptides in hela cells, we studied the effect of several n-ter ...	1995	7853516
phylogeny of tyu, sre, and cfa virus: different evolutionary rates in the genus flavivirus.	the nucleotide and deduced amino acid sequence of the envelope (e) gene of tyuleniy (tyu) and saumarez reef (sre) virus have been determined and the data used to classify these viruses in relation to the other tick- and mosquito-borne viruses in the genus flavivirus. the phylogenetic trees obtained by maximum parsimony and distance methods for 22 flavivirus e genes showed that tyu and sre virus are a sister group of the tbe virus complex. the trees were consistent with the flavivirus serological ...	1995	7856087
formation of the flavivirus envelope: role of the viral ns2b-ns3 protease.	one of the late processing events in the flavivirus replication cycle involves cleavage of the intracellular form of the flavivirus capsid protein (cint) to the mature virion form (cvir) lacking the carboxy-terminal stretch of hydrophobic amino acids which serves as a signal peptide for the downstream prm protein. this cleavage event was hypothesized to be effected by a viral protease and to be associated with virion formation. we have proposed a model of flavivirus virion formation in which pro ...	1995	7884844
[genome sequence and antigen structure of the powassan virus: analysis of genetic elements of tick-transmitted flaviviruses].		1995	7886964
processing of japanese encephalitis virus non-structural proteins: ns2b-ns3 complex and heterologous proteases.	processing of japanese encephalitis (je) virus non-structural (ns) proteins expressed by recombinant vaccinia viruses was analysed to characterize the responsible viral protease. analysis of the processing of polyprotein ns2a-2b-3' containing the n-terminal 322 amino acids of ns3 revealed products consistent with cleavages at the predicted intergenic junctions as well as at one or possibly two sites within ns2a. cleavage at the alternate site(s) containing the cleavage sequence motif within ns2a ...	1995	7897348
substrate determinants for cleavage in cis and in trans by the hepatitis c virus ns3 proteinase.	processing of the hepatitis c virus polyprotein is accomplished by a series of cotranslational and posttranslational cleavages mediated by host cell signalases and two virally encoded proteinases. of these the ns3 proteinase is essential for processing at the ns3/4a, ns4a/4b, ns4b/5a, and ns5a/5b junctions. processing between ns3 and ns4a occurs in cis, implying an intramolecular reaction mechanism, whereas cleavage at the other sites can also be mediated in trans. sequence analysis of the amino ...	1995	7983710
identification of tick-borne encephalitis virus ribonucleic acid in tick suspensions and in clinical specimens by a reverse transcription-nested polymerase chain reaction assay.	tick-borne encephalitis virus (tbev) is a major human pathogenic flavivirus. sensitive assays for the detection of viral rna may be valuable both for the identification of virus in ticks as well as for diagnostic purposes.	1995	15566853
[viral encephalitis after tick bite].	tbe is caused by a flavivirus and is endemic in certain areas of central and eastern europe, such as austria, the south of germany, hungary, czechoslovakia, poland, the former yugoslavia and sng and certain areas of sweden and finland. recent developments in the eastern european countries have made them popular with danish travellers, who are thus exposed to infection. until now tbe has been a very rare disease in denmark. the clinical course is biphasic being preceded by an incubation period of ...	1994	7985272
use of a flavivirus rna-dependent rna polymerase assay to investigate the antiviral activity of selected compounds.	we have developed an assay using flavivirus rna-dependent rna polymerase to test the inhibitory activity of potential antiviral agents. the effects of antiviral agents on rna synthesis were examined in this assay using extracts of vero cells infected with dengue virus type 2 or kunjin virus. several different classes of known polymerase inhibitors were tested. the synthesis of double-stranded replicative form rna was inhibited in a dose-dependent fashion in the presence of the polyoxometalate hp ...	1994	7993077
medically important arboviruses of the united states and canada.	of more than 500 arboviruses recognized worldwide, 5 were first isolated in canada and 58 were first isolated in the united states. six of these viruses are human pathogens: western equine encephalitis (wee) and eastern equine encephalitis (eee) viruses (family togaviridae, genus alphavirus), st. louis encephalitis (sle) and powassan (pow) viruses (flaviviridae, flavivirus), lacrosse (lac) virus (bunyaviridae, bunyavirus), and colorado tick fever (ctf) virus (reoviridae, coltivirus). their scien ...	1994	8118792