Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| identification of australian arboviruses in inoculated cell cultures using monoclonal antibodies in elisa. | an elisa using a panel of specific monoclonal antibodies was developed to identify all alpha and flaviviruses isolated from mosquitoes caught throughout australia. this technique is sensitive and rapid and is more specific than the traditional methods used to identify flaviviruses. the ability to identify unknown virus isolates from field-caught mosquitoes quickly and accurately improves the efficiency of arbovirus surveillance programs and allows health authorities to give an early warning of a ... | 1998 | 9770194 |
| dna-based and alphavirus-vectored immunisation with prm and e proteins elicits long-lived and protective immunity against the flavivirus, murray valley encephalitis virus. | the immunogenicity and protective efficacy of dna-based vaccination with plasmids encoding the membrane proteins prm and e of the flavivirus murray valley encephalitis virus (mve) were investigated. gene gun-mediated intradermal delivery of dna encoding the prm and e proteins elicited long-lived, virus-neutralising antibody responses in three inbred strains of mice and provided protection from challenge with a high titer inoculum of mve. intramuscular dna vaccination by needle injection also ind ... | 1998 | 9770429 |
| 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 |
| prevalence of infection with hepatitis g virus among various groups in thailand. | two research groups recently and independently, isolated a hepatotropic flavivirus from human sera. the two viruses, named gb virus c and hepatitis g virus (hgv), were subsequently discovered to represent the same virus, which was associated with acute and chronic hepatitis of the non-a-e type. the prevalences of infection with hgv have now been investigated in various groups of the thai population, some of which [e.g. thalassaemic children, patients with chronic liver disease, carriers of antib ... | 1998 | 9614458 |
| encapsidation of the flavivirus kunjin replicon rna by using a complementation system providing kunjin virus structural proteins in trans. | kunjin virus (kun) replicon rna was encapsidated by a procedure involving two consecutive electroporations of bhk-21 cells, first with kun replicon rna c20dxrep (with prme and most of c deleted) and about 24 h later with a recombinant semliki forest virus (sfv) replicon rna(s) expressing kun structural proteins. the presence of kun replicon rna in encapsidated particles was demonstrated by its amplification and expression in newly infected bhk-21 cells, detected by northern blotting with a kun-s ... | 1998 | 9621059 |
| the ns5a/ns5 proteins of viruses from three genera of the family flaviviridae are phosphorylated by associated serine/threonine kinases. | phosphorylation of the expressed ns5a protein of hepatitis c virus (hcv), a member of the hepacivirus genus of the family flaviviridae, has been demonstrated in mammalian cells and in a cell-free assay by an associated kinase activity. in this report, phosphorylation is also shown for the ns5a and ns5 proteins, respectively, of bovine viral diarrhea virus (bvdv) and yellow fever virus (yf), members of the other two established genera in this family. phosphorylation of bvdv ns5a and yf ns5 was ob ... | 1998 | 9621090 |
| [studying the possibility of respiratory immunization against tick-borne encephalitis]. | there are known 3 likely mechanisms of virus conveyance into the central nervous system (cns). these include hematogenic penetration, spread along the peripheral nerves, and the olfactory pathway which begins from the infected olfactory neuroepithelial cells. the possibility of viral spread into cns via the olfactory pathway was shown for the representatives of togaviruses, herpesviruses, coronaviruses, rhabdoviruses, and for some others. this study suggests that the olfactory pathway of viral c ... | 1998 | 9633235 |
| subcellular localization and some biochemical properties of the flavivirus kunjin nonstructural proteins ns2a and ns4a. | in a previous study on the replication of kunjin virus using immunoelectron microscopy (e. g. westaway, j. m. mackenzie, m. t. kenney, m. k. jones, and a. a. khromykh, 1997, j. virol. 71, 6650-6661), ns1 and ns3 were found associated with double-stranded rna (dsrna) within vesicle packets (vp) in infected vero cells, suggesting that these induced membrane structures may be the cytoplasmic sites of rna replication. ns2b and ns3 (comprising the virus-encoded protease) were colocalized within disti ... | 1998 | 9636360 |
| genetically determined resistance to flavivirus infection in wild mus musculus domesticus and other taxonomic groups in the genus mus. | inherited resistance to flaviviruses in laboratory mice is a rare trait conferred by an autosomal dominant gene (flvr). to provide information on genetic resistance to flaviviruses in wild mice, we analysed (i) wild m. m. domesticus trapped in australia, and (ii) mice representing other species and subspecies in the genus mus. mice were screened for resistance relative to c3h/hej mice by intracerebral challenge with murray valley encephalitis virus or yellow fever virus, and breeding studies wer ... | 1998 | 9638142 |
| genetic control of host resistance to flavivirus infection in animals. | flaviviruses are small, enveloped rna viruses which are generally transmitted by arthropods to animals and man. although flaviviruses cause important diseases in domestic animals and man, flaviviral infection of animals which constitute the normal vertebrate reservoir may be mild or sub-clinical, which suggests that some adaptation between virus and host may have occurred. while this possibility is difficult to study in wild animals, extensive studies using laboratory mice have demonstrated the ... | 1998 | 9638813 |
| gb virus c: a novel pathogen or a curiosity for virologists? | the recently identified gb virus c is a flavivirus related to the hepatitis c virus. it appears quite prevalent in the general population and especially in individuals at risk of parenteral transmission. many questions remain, most importantly the pathogenic role of the virus. it is unlikely that this virus has a major role in hepatic disease. | 1998 | 9639948 |
| a presumptive case of fatal murray valley encephalitis acquired in alice springs. | a presumptive case of murray valley encephalitis (mve) acquired in alice springs in march 1997 is reported. the patient subsequently died in mackay. the diagnosis of murray valley encephalitis was supported by the detection of flavivirus igm in cerebrospinal fluid. low titres of igm specific to murray valley encephalitis and alfuy were detected in a single serum sample. the patient's travel movements indicate that his infection was acquired in the alice springs vicinity. this conclusion was furt ... | 1998 | 9648367 |
| dengue or kokobera? a case report from the top end of the northern territory. | in early april 1998, the centre for disease control in darwin was notified of a possible case of dengue which appeared to have been acquired in the northern territory. because dengue is not endemic to the northern territory, locally acquired infection has significant public health implications, particularly for vector identification and control to limit the spread of infection. dengue igm serology was positive on two occasions, but the illness was eventually presumptively identified as kokobera ... | 1998 | 9648368 |
| critical point mutations for hepatitis c virus ns3 proteinase. | the hepatitis c virus ns3 proteinase plays an essential role in processing of hcv nonstructural precursor polyprotein. to detect its processing activity, we developed a simple trans-cleavage assay. two recombinant plasmids expressing the ns3 proteinase region and a chimeric substrate polyprotein containing the ns5a/5b cleavage site between maltose binding protein and protein a were co-introduced into escherichia coli cells. the proteinase processed the substrate at the single site during their p ... | 1998 | 9656998 |
| monoclonal antibody mapping of the envelope glycoprotein of the dengue 2 virus, jamaica. | although dengue (den) virus is the etiologic agent of dengue fever, the most prevalent vector-borne viral disease in the world, precise information on the antigenic structure of the dengue virion is limited. we have prepared a set of murine monoclonal antibodies (mabs) specific for the envelope (e) glycoprotein of den 2 virus and used these antibodies in a comprehensive biological and biochemical analysis to identify 16 epitopes. following domain nomenclature developed for the related flavivirus ... | 1998 | 9657950 |
| recombinant dengue virus type 1 ns3 protein exhibits specific viral rna binding and ntpase activity regulated by the ns5 protein. | the full-length dengue virus ns3 protein has been successfully expressed as a 94-kda gst fusion protein in escherichia coli. treatment of the purified fusion protein with thrombin released a 68-kda protein which is the expected molecular mass for the den1 ns3 protein. the identity of this protein was confirmed by western blotting using dengue virus antisera. two related activities of the recombinant ns3 protein were characterized, which were the binding of the protein to the 3'-noncoding region ... | 1998 | 9657959 |
| hepatitis g infection: role in cryptogenic chronic liver disease and primary liver cell cancer in the uk. trent hepatitis c virus study group. | hepatitis g virus (hgv) is a flavivirus that can cause acute hepatitis and persistent infection but its role in chronic liver disease or primary liver cancer is unproven. in this study we have examined the prevalence of hgv rna in the serum of patients with hepatitis c virus (hcv) infection and in patients with cryptogenic chronic liver disease, including non-alcoholic steatohepatitis (nash), and in patients with hcv-related hepatocellular carcinoma (hcc) and hcc arising in patients with cryptog ... | 1998 | 9658369 |
| the metal binding site of the hepatitis c virus ns3 protease. a spectroscopic investigation. | the ns3 region of the hepatitis c virus encodes for a serine protease activity, which is necessary for the processing of the nonstructural region of the viral polyprotein. the minimal domain with proteolytic activity resides in the n terminus, where a structural tetradentate zinc binding site is located. the ligands being been identified by x-ray crystallography as being three cysteines (cys97, cys99, and cys145) and one histidine residue (his149), which is postulated to coordinate the metal thr ... | 1998 | 9668049 |
| tumor necrosis factor alpha levels in plasma and whole-blood culture in dengue-infected patients: relationship between virus detection and pre-existing specific antibodies. | the pathogenesis of dengue hemorrhagic fever (dhf) is not well known, but the role of host factors has been suggested. the level of immunoreactive circulating and cell-generated tumor necrosis factor alpha (tnf alpha) was studied in 35 patients with dhf; its relationship with virus isolation and/or genome detection by reverse transcription polymerase chain reaction (rt-pcr) and specific antibodies were detected by hemagglutination inhibition (hi). large variation of tnf alpha plasma levels was o ... | 1998 | 9515771 |
| neutralizing antibodies protect against lethal flavivirus challenge but allow for the development of active humoral immunity to a nonstructural virus protein. | antibody-mediated neutralization of viruses has been extensively studied in vitro, but the precise mechanisms that account for antibody-mediated protection against viral infection in vivo still remain largely uncharacterized. the two points under discussion are antibodies conferring sterilizing immunity by neutralizing the virus inoculum or protection against the development of disease without complete inhibition of virus replication. for tick-borne encephalitis virus (tbev), a flavivirus, trans ... | 1998 | 9525632 |
| emerging viruses. | an emerging virus is a term applied to a newly discovered virus, one that is increasing in incidence or with the potential to increase in incidence. many viruses fit into this definition. hiv is the clearest example of a previously unknown virus that has now produced one of the largest pandemics in history. recent advances have occurred in the identification and understanding of new hantaviruses in the americas, causing an acute respiratory disease. the possible causal role of human herpesvirus ... | 1998 | 9529635 |
| antibodies to alphavirus, flavivirus, and bunyavirus arboviruses in house sparrows (passer domesticus) and tree sparrows (p. montanus) in poland. | sparrows from central poland were examined by a hemagglutination-inhibition test (titer > or = 20) for the presence of antibodies to arboviruses, between 1995 and 1996. in house sparrows (passer domesticus) (n = 179), antibodies to sindbis, west nile, tick-borne encephalitis, tahyna, and calovo viruses were detected at seroprevalences of 1.1%, 2.8%, 1.1%, 2.8%, and 1.1%, respectively. in tree sparrows (p. montanus) (n = 33), antibodies to the sindbis, west nile, and tahyna viruses were detected ... | 1998 | 9533098 |
| hcv and hgv in b-cell non-hodgkin's lymphoma. | a causative role of hepatitis c virus infection (hcv) has been discussed in the pathogenesis of mixed cryoglobulinaemia and in b-cell non-hodgkin's lymphoma. no data are available concerning the newly discovered hepatitis g virus (hgv) and extrahepatic manifestations such as haematological malignancies. but, hcv and hgv most probably belong to the same family of flavivirus. consequently, we looked for the prevalence of hcv, hgv and cryoglobulins in patients with b-cell non-hodgkin's lymphoma. | 1998 | 9537861 |
| conversion of dengue virus replicative form rna (rf) to replicative intermediate (ri) by nonstructural proteins ns-5 and ns-3. | dengue viruses infect more than 100 million people each year and cause serious clinical manifestations. it is important to understand the replication of these viruses so that therapeutic and/or prophylactic agents may be designed. dengue virus type 2 nonstructural proteins ns-5 and ns-3 were produced by in vitro transcription and translation of cloned genes. both proteins possessed rna-dependent rna polymerase activity as measured by their ability to convert purified replicative form (rf) rna to ... | 1998 | 9452298 |
| dengue fever epidemic potential as projected by general circulation models of global climate change. | climate factors influence the transmission of dengue fever, the world's most widespread vector-borne virus. we examined the potential added risk posed by global climate change on dengue transmission using computer-based simulation analysis to link temperature output from three climate general circulation models (gcms) to a dengue vectorial capacity equation. our outcome measure, epidemic potential, is the reciprocal of the critical mosquito density threshold of the vectorial capacity equation. a ... | 1998 | 9452414 |
| definition of an epitope on ns3 recognized by human cd4+ cytotoxic t lymphocyte clones cross-reactive for dengue virus types 2, 3, and 4. | the role of dengue virus-specific serotype-cross-reactive t lymphocytes in recovery from and pathogenesis of dengue virus infections is not known. in the present paper, we have defined a dengue serotype-cross-reactive epitope recognized by two cd4+ cd8- cytotoxic t lymphocyte (ctl) clones, jk36 and jk46. these t cell clones were established from the peripheral blood t lymphocytes of a dengue-3-immune donor, using a limiting dilution method. jk36 and jk46 were cross-reactive for dengue virus type ... | 1998 | 9454689 |
| attenuation of the langat tick-borne flavivirus by chimerization with mosquito-borne flavivirus dengue type 4. | langat virus (lgt) strain tp21 is the most attenuated of the tick-borne flaviviruses for humans. even though lgt has low-level neurovirulence for humans, it, and its more attenuated egg-passage derivative, strain e5, exhibit significant neurovirulence and neuroinvasiveness in normal mice, albeit less than that associated with tick-borne encephalitis virus (tbev), the most virulent of the tick-borne flaviviruses. we sought to reduce or ablate these viral phenotypes of tp21 and e5 by using a strat ... | 1998 | 9465088 |
| fulminant hepatitis and the new g/gbv-c flavivirus. | a new virus within the family flaviviridae. 'hepatitis' g/gbv-c, has been incriminated by several authors as a causative factor of idiopathic or cryptogenic fulminant hepatitis, a syndrome of presumed viral aetiology. review of worldwide data from 22 studies on 364 cases indicates that g/gbv-c infection is present in approximately 20% of idiopathic cases but a similar or even higher prevalence is detected in fulminant hepatitis of viral b, d or c aetiology, reflecting a high rate of parenteral v ... | 1998 | 9493512 |
| patterns of hepatitis g viraemia and liver disease in haemophiliacs previously exposed to non-virus inactivated coagulation factor concentrates. | hepatitis g virus (hgv), a novel flavivirus, has been implicated as a cause of posttransfusion hepatitis. we have performed a longitudinal study in a cohort of haemophiliacs (n = 68) who previously received non-virus inactivated coagulation factor concentrates to assess both patterns of hgv viraemia and any associated liver disease. hepatitis c virus (hcv) rna was present in 58/68 and co-infection with human immunodeficiency virus (hiv) was present in 15/68. hgv rna was detected in 17/68 (25%) s ... | 1998 | 9493578 |
| inhibitory effect of furanonaphthoquinone derivatives on the replication of japanese encephalitis virus. | japanese encephalitis still occurs in endemic and epidemic forms over a wide area of asia. although the vaccine against japanese encephalitis virus (jev) is widely used, no antiviral drug has been reported. we used several different kinds of furanonaphthoquinone derivatives and found antiviral activity against jev. especially, 2-methylnaphtho[2,3-b]furan-4,9-dione (fnq3) indicated the highest antiviral activity, followed by 2-(1-hydroxyethyl)-, 5(or 8)-hydroxy-, and 2-methyl-5(or 8)-hydroxy-anal ... | 1998 | 9497071 |
| spontaneous and engineered deletions in the 3' noncoding region of tick-borne encephalitis virus: construction of highly attenuated mutants of a flavivirus. | the flavivirus genome is a positive-strand rna molecule containing a single long open reading frame flanked by noncoding regions (ncr) that mediate crucial processes of the viral life cycle. the 3' ncr of tick-borne encephalitis (tbe) virus can be divided into a variable region that is highly heterogeneous in length among strains of tbe virus and in certain cases includes an internal poly(a) tract and a 3'-terminal conserved core element that is believed to fold as a whole into a well-defined se ... | 1998 | 9499069 |
| signal peptidase cleavage at the flavivirus c-prm junction: dependence on the viral ns2b-3 protease for efficient processing requires determinants in c, the signal peptide, and prm. | signal peptidase cleavage at the c-prm junction in the flavivirus structural polyprotein is inefficient in the absence of the cytoplasmic viral protease, which catalyzes cleavage at the cooh terminus of the c protein. the signal peptidase cleavage occurs efficiently in circumstances where the c protein is deleted or if the viral protease complex is present. in this study, we used cdna of murray valley encephalitis virus (mve) to examine features of the structural polyprotein which allow this reg ... | 1998 | 9499070 |
| characterization of defective viral rna produced during persistent infection of vero cells with murray valley encephalitis virus. | defective interfering viral particles are readily produced in cell culture after a high multiplicity of infection with many animal rna viruses. due to defects that they carry in their genomes, their life cycle needs to be complemented by the helper functions provided by a parental virus which makes them both dependent on and competitive with the parental virus. in many instances, this may cause the abrogation of a lytic cycle of the parental virus, leading to a persistent infection. in this pape ... | 1998 | 9499109 |
| evaluation of recombinant dengue viral envelope b domain protein antigens for the detection of dengue complex-specific antibodies. | to increase the specificity of dengue (den) diagnosis based on antibody detection, we have evaluated recombinant proteins as antigens that incorporate most of the b domain of the den virus envelope protein fused to the trpe protein of escherichia coli (trpe-den). a pooled antigen consisting of trpe-den proteins representing all four serotypes of den virus was used in an indirect elisa for the detection of igg or igm antibody. this assay was compared with a standard igg indirect elisa and an igm- ... | 1998 | 9502595 |
| hepatic histology in hepatitis c virus carriers coinfected with hepatitis g virus. | a novel flavivirus has been described recently and designated hepatitis g virus (hgv). the virus is transmitted by the parenteral route but it is uncertain whether it is associated with chronic liver disease because liver biopsy is difficult to justify in this group. | 1998 | 9505894 |
| african origin of gb virus c/hepatitis g virus. | ninety-four gb virus c/hepatitis g virus (gbv-c/ hgv) rna-positive serum samples were obtained from all over the world. we found that all 15 gbv-c/hgv isolates from the pygmies and the bantu in the central african region had a 12-amino acid indel (i.e. insertion or deletion) in the non-structural protein (ns) 5a region. phylogenetic analyses of the ns5a region, using gbv-a as an outgroup, showed that these 15 isolates had diverged from the common ancestor much earlier than the remaining isolates ... | 1998 | 9512347 |
| 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 |
| 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 |
| dna immunization with japanese encephalitis virus nonstructural protein ns1 elicits protective immunity in mice. | japanese encephalitis virus (jev), a mosquito-borne flavivirus, is a zoonotic pathogen that is prevalent in some southeast asian countries and causes acute encephalitis in humans. to evaluate the potential application of gene immunization to jev infection, we characterized the immune responses from mice intramuscularly injected with plasmid dna encoding jev glycoproteins, including the precursor membrane (prm) plus envelope (e) proteins and the nonstructural protein ns1. when injected with the p ... | 1998 | 9420215 |
| mutagenesis of the ns3 protease of dengue virus type 2. | the flavivirus protease is composed of two viral proteins, ns2b and ns3. the amino-terminal portion of ns3 contains sequence and structural motifs characteristic of bacterial and cellular trypsin-like proteases. we have undertaken a mutational analysis of the region of ns3 which contains the catalytic serine, five putative substrate binding residues, and several residues that are highly conserved among flavivirus proteases and among all serine proteases. in all, 46 single-amino-acid substitution ... | 1998 | 9420267 |
| in vitro infection of human peripheral blood mononuclear cells by gb virus c/hepatitis g virus. | gb virus c (gbv-c), also known as hepatitis g virus, is a recently discovered flavivirus-like rna agent with unclear pathogenic implications. to investigate whether human peripheral blood mononuclear cells (pbmc) are susceptible to in vitro gbv-c infection, we have incubated pbmc from four healthy blood donors with a human gbv-c rna-positive serum. by means of (i) strand-specific reverse transcription-pcr, cloning, and sequencing; (ii) sucrose ultracentrifugation and rnase sensitivity assays; (i ... | 1999 | 10196301 |
| the clinical significance of simultaneous infection with hepatitis g virus in patients with chronic hepatitis c. | hepatitis g virus (hgv) is a recently discovered member of the flavivirus family that has been associated with acute and chronic hepatitis. hgv infection has been reported to coexist in 10-20% of patients with chronic hepatitis c. the significance of simultaneous infection with hgv and hepatitis c virus (hcv) remains to be clarified, as do the effects on hgv of therapeutic interventions such as interferon treatment or liver transplantation. the aims of our study were: 1) to examine the frequency ... | 1999 | 10201473 |
| the 37-amino-acid interdomain of dengue virus ns5 protein contains a functional nls and inhibitory ck2 site. | the dengue virus ns5 rna-dependent rna polymerase has been detected in the nucleus of virus-infected mammalian cells. we demonstrate here for the first time using in vitro and in vivo assay systems that the 37-amino-acid linker interdomain of ns5 (residues 369 to 405) contains a nuclear localization sequence (nls) which is capable of targeting b-galactosidase to the nucleus. further, we show that the linker is recognized by subunits of the nls-binding importin complex with an affinity similar to ... | 1999 | 10208852 |
| development and characterization of new flavivirus-resistant mouse strains bearing flv(r)-like and flv(mr) alleles from wild or wild-derived mice. | a single genetic locus, flavivirus resistance (flv), controls virus titres and severity of flavivirus infection in mouse brain. it has been mapped to mouse chromosome 5 and shown to include different allelic forms. while the majority of laboratory mouse strains are susceptible to flaviviruses and carry the flv(s) allele, wild mice and laboratory mouse strains recently derived from them are resistant and carry flavivirus-resistance alleles including flv(r)-like and flv(mr) alleles. although there ... | 1999 | 10211958 |
| recombinant, chimaeric live, attenuated vaccine (chimerivax) incorporating the envelope genes of japanese encephalitis (sa14-14-2) virus and the capsid and nonstructural genes of yellow fever (17d) virus is safe, immunogenic and protective in non-human primates. | yellow fever 17d virus, a safe and effective live, attenuated vaccine, was used as a vector for genes encoding the protective antigenic determinants of a heterologous member of the genus flavivirus, japanese encephalitis (je) virus, the leading cause of acute viral central nervous system infection and death throughout asia. the viral envelope (prm and e) genes of a full-length cdna clone of yf 17d virus were replaced with the corresponding genes of je sa14-14-2, a strain licensed as a live, atte ... | 1999 | 10217584 |
| identification and analysis of truncated and elongated species of the flavivirus ns1 protein. | the flavivirus non-structural glycoprotein ns1 is often detected in western blots as a heterogeneous cluster of bands due to glycosylation variations, precursor-product relationships and/or alternative cleavage sites in the viral polyprotein. in this study, we determined the basis of structural heterogeneity of the ns1 protein of murray valley encephalitis virus (mve) by glycosylation analysis, pulse-chase experiments and terminal amino acid sequencing. inhibition of n-linked glycosylation by tu ... | 1999 | 10225275 |
| genetic interaction of flavivirus nonstructural proteins ns1 and ns4a as a determinant of replicase function. | nonstructural protein 1 (ns1) of yellow fever virus (yf) is a glycoprotein localized to extracytoplasmic compartments within infected cells. we have previously shown that ns1 can be supplied in trans and is required for viral rna replication, a process thought to occur in membrane-bound cytoplasmic complexes. here we report that the ns1 gene from a related virus, dengue virus (den), is unable to function in the process of yf rna replication. this virus-specific incompatibility leads to a lack of ... | 1999 | 10233920 |
| nascent flavivirus rna colocalized in situ with double-stranded rna in stable replication complexes. | incorporation of bromouridine (bru) into viral rna in kunjin virus-infected vero cells treated with actinomycin d was monitored in situ by immunofluorescence using antibodies reactive with br-rna. the results showed unequivocally that nascent viral rna was located focally in the same subcellular site as dsrna, the putative template for flavivirus rna synthesis. when cells were labeled with bru for 15 min, the estimated cycle period for rna synthesis, the nascent br-rna was not digested in permea ... | 1999 | 10329573 |
| 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 |
| 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 |
| 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 |
| 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 |
| the ns5 gene location of two turkey meningoencephalitis virus genomic sequences. | two new turkey meningoencephalitis virus (tmev) nucleotide sequences were aligned to complete sequences of genomes of the flaviviruses that were available at present in the genebank. it was found that the both tmev sequences represent different ns5 locations; the sequence with acc. no. af098456 is located downstream of that with acc. no. af013377 on the tmev ns5 gene. this finding provides further insight into the tmev ns5 gene structure and shows that the two sequences are located on the ns5 ge ... | 1999 | 10825933 |
| [hepatitis c virus and resulting diseases]. | in 1989, the main agent causing non a non b hepatitis was identified as a rna virus of the flavivirus family, with several serotypes, and was denominated virus c. at the present moment, the knowledge about the infection features and diseases that it causes has expanded thanks to the availability of reliable laboratory techniques to detect the antibody and the virus. the prevalence of infection and the frequency of serotypes varies in different regions of the world. chile is a country with a low ... | 1999 | 10835742 |
| rapid diagnosis of primary dengue fever by the immunochromatographic test and by electron microscopy--a case report. | a 21-year-old woman presented with an acute febrile illness after a two-week holiday in jamaica. her symptoms started two days after return, with sudden onset of continuous high fever (> 39 degrees c), dizziness and nausea. three days later she developed a generalized macular rash, which led to the tentative diagnosis "acute dengue fever." laboratory confirmation was achieved by demonstrating anti-dengue igm and igg antibodies in paired sera; in addition, flavivirus particles were directly visua ... | 1999 | 10624599 |
| ultrastructural aspects of the dengue virus (flavivirus) particle morphogenesis. | the pathway of dengue virus infection in both mosquito and vero cells in culture has been described. however, a number of stages associated with dengue virus morphogenesis remain unclear. for this reason further study involving electron microscopic in situ hybridisation of viral rna and immunolocalisation of envelope proteins was carried out. the data obtained support the hypothesis that both viral rna and viral proteins assemble when anchored to the viral-induced smooth membrane structures whic ... | 1999 | 10626007 |
| 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 |
| [west nile virus: a migrating arbovirus of current interest]. | west nile (wn) virus is a common arbovirosis in sub-saharian africa. it has occasionally caused epidemics or epizootics in horses in mediterranean regions and southern europe. the virus is transmitted to humans by mosquitoes (primarily the culex species) that are infected by biting viremic birds. infections in humans are usually asymptomatic. recently, however, a growing number of cases involving central nervous system manifestations and deaths have been reported in elderly people in algeria and ... | 1999 | 10901852 |
| molecular characterization of the 5' non-coding region of south african gbv-c/hgv isolates: major deletion and evidence for a fourth genotype. | gb virus c/hepatitis g virus (gbv-c/hgv) has been characterised as a novel flavivirus, and to date three known genotypes have been cloned. greater genetic variation of gbv-c/hgv has been demonstrated in west african isolates, but no major deletions have been shown in the 5' non-coding region (ncr). the 5'ncr regulates protein translation via an internal ribosomal entry site (ires). we cloned, sequenced, and analysed a 344-bp polymerase chain reaction (pcr) product, representing >60% of the 5'ncr ... | 1999 | 10440808 |
| prediction of three-dimensional structure and mapping of conformational epitopes of envelope glycoprotein of japanese encephalitis virus. | japanese encephalitis virus (jev), a mosquito-borne flavivirus, is an important human pathogen. the envelope glycoprotein (egp), a major structural antigen, is responsible for viral haemagglutination and eliciting neutralising antibodies. the three-dimensional structure of the egp of jev was predicted using the knowledge-based homology modeling approach and x-ray structure data of the egp of tick-borne encephalitis virus as a template (rey et al., 1995). in the initial stages of optimisation, a ... | 1999 | 10441554 |
| partial agonist effect influences the ctl response to a heterologous dengue virus serotype. | activation of dengue serotype-cross-reactive memory ctl during secondary dengue virus (dv) infection is thought to be important in the pathogenesis of dengue hemorrhagic fever. to model this effect, we studied the ctl responses to dv types 2 (d2v) and 3 (d3v) in pbmc from an individual previously infected with d3v. dv-specific cd8+ ctl from this donor recognized two hla-b62-restricted epitopes on the ns3 protein, aa 71-79 (svkkdlisy) and 235-243 (amkglpiry). both d3v-specific and d2v/d3v-cross-r ... | 1999 | 10453018 |
| 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 |