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characterisation of an hcv ns3/ns4a proteinase fusion protein expressed in e.coli using synthetic peptide substrates. 19979450052
[arbovirus infections. from virus, mosquitoes, animals and humans].arboviruses occur throughout the world in plants and animals: reptiles, birds and mammals including man. these relatively recent rna-containing viruses have great evolutionary potential and are a major cause of epidemics. arboviruses exhibit a dual life cycle involving continual transmission to and from the vertebrate host and arthropod vector which ingests or inoculates the agent during blood meals. agents belong to many different viral families and represent an important source of emerging dis ...19979513176
phosphorylation of tick-borne encephalitis virus ns5 protein.the largest tick-borne encephalitis virus (tbev) non-structural protein ns5 (100 kda) is believed to be involved in rna replication. the protein is phosphorylated in infected cell extracts in the presence of [gamma-32p]atp, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page) and western blot analysis using monoclonal antibodies raised against tbev ns5 protein. radioactive labeling of ns5 in cellular extracts at an early stage post-infection is higher than at 24 h po ...19979178492
towards defining a minimal functional domain for ntpase and rna helicase activities of the hepatitis c virus ns3 protein.hepatitis c virus (hcv) possesses two separate enzymatic functions in the ns3 protein: a protease and an ntpase/rna helicase. in order to determine the minimal domain for ntpase and rna helicase activities of the hcv ns3 protein, serial deletion mutants were constructed. the ns3h protein a fusion protein of 25 amino acids (aa) from an expression vector and the c-terminal 466 aa of the hcv ns3 protein, contains an ntpase/rna helicase activity. we made deletion mutants of 10, 30, 50, 97, and 135 a ...19979178493
complete sequence of two tick-borne flaviviruses isolated from siberia and the uk: analysis and significance of the 5' and 3'-utrs.the complete nucleotide sequence of two tick-transmitted flaviviruses, vasilchenko (vs) from siberia and louping ill (li) from the uk, have been determined. the genomes were respectively, 10928 and 10871 nucleotides (nt) in length. the coding strategy and functional protein sequence motifs of tick-borne flaviviruses are presented in both vs and li viruses. the phylogenies based on maximum likelihood, maximum parsimony and distance analysis of the polyproteins, identified vs virus as a member of ...19979178494
[a comparative analysis of proteins from persistent and antigen-defective strains of tick-borne encephalitis virus].structural (e) and three nonstructural (ns1, ns3, and ns5) proteins of persistent and antigen-defective strains of tick-borne encephalitis virus are compared by immunoblotting with monoclonal antibodies to the corresponding proteins of strain sofyin. appreciable phenotypical differences were revealed between antigen-defective strains, but no immunological modifications as concerns the studied antigenic structures. the size of the reference ns3 protein differed from that of the persistent virus s ...19979182398
application of an immunoperoxidase monolayer assay for the detection of arboviral antibodies.an immunoperoxidase monolayer assay (ipma) was adapted for the detection of antibodies to six arboviruses: three viruses within the flavivirus group (dengue 2, west nile (wn) and yellow fever) and three in the phlebovirus group (rift valley fever (rvf), sandfly fever naples and sandfly fever sicilian). antibody titers of homologous hyper-immune mouse ascitic fluid (hmaf) measured by ipma were two to eight-fold less than those determined by elisa. in tests with heterologous hmaf, cross-reactions ...19979186937
communicable diseases surveillance. 19979188219
inhibition of japanese encephalitis virus infection by nitric oxide: antiviral effect of nitric oxide on rna virus replication.the antiviral effects of nitric oxide (no) on japanese encephalitis virus (jev), a member of the family flaviviridae, were investigated in this study. in vitro, inhibition of replication of jev in gamma interferon-activated raw 264.7 murine macrophages was correlated to cellular no production. when cocultured with infected murine neuroblastoma n18 cells, gamma interferon-activated raw 264.7 cells also efficiently hindered jev replication in contiguous bystanders, and this anti-jev effect could b ...19979188590
changes in the dengue virus major envelope protein on passaging and their localization on the three-dimensional structure of the protein.to help define the molecular events involved in dengue virus adaptation during serial passage in vivo and in cultured cells, we have sequenced the structural protein genes of three dengue type 3 isolates after intracerebral passage in mice and after passage in cultured monkey kidney (vero) and aedes albopictus (mosquito) cells. passaging in each host selected for amino acid changes in the envelope protein e and occasionally in prm but not in the capsid protein. most changes were first apparent w ...19979191841
yellow fever virus envelope protein has two discrete type-specific neutralizing epitopes.two monoclonal antibody neutralization resistant (mabr) variants of the yellow fever (yf) 17d-204 vaccine virus strain were selected using yf type-specific mab b39. these b39r variants were compared with the variant virus selected by lobigs et al. (virology 161, 474-478, 1987) using a second yf-type specific mab (2e10) which mapped to amino acid position 71/72 in the envelope (e) protein. neutralization assays with a panel of mabs suggested that these two yf-type-specific epitopes are located in ...19979191929
isolation of a flavivirus related to the tick-borne encephalitis complex from human cases in saudi arabia.a flavivirus related to the tick-borne encephalitis complex was isolated from the blood of 6 male butchers, aged 24-39 years, in jeddah, saudi arabia in november and december 1995. two of the patients died and the other 4 recovered completely. four more patients, 3 males and 1 female, were diagnosed serologically by immunoglobulin m capture enzyme-linked immunosorbent assay and seroconversion in acute and convalescent blood samples examined by indirect immunofluorescent test using vero cells inf ...19979196762
a conserved internal hydrophobic domain mediates the stable membrane integration of the dengue virus capsid protein.the mature flavivirus capsid protein (virion c) is commonly thought to be free in the cytoplasm of infected cells and to form a nucleocapsid-like complex with genomic rna in mature virus particles. there is little sequence conservation among flavivirus virion c proteins, but they are similar in size (e.g., 99 amino acids [aa] for the dengue-4 [den4] c) and in bearing a net positive charge. in addition, we noted that c contained a conserved internal hydrophobic segment (spanning aa 45-65 in the d ...19979201220
high prevalence of gb virus c/hepatitis g virus in healthy persons in ho chi minh city, vietnam.gb virus c or hepatitis g virus (gbv-c/hgv), a novel flavivirus, is detected in 1.5% of us blood donors. the prevalence is higher in multiply transfused patients and in persons with liver disease. because of the increased incidence of hepatitis in asia, sera from healthy vietnamese were tested for the presence of gbv-c/hgv rna by the reverse transcription polymerase chain reaction. viral rna was detected in 5.7% of those tested; 6 of 81 volunteer blood donors had positive samples as did 5 of 97 ...19979203671
secondary structure of the 3'-noncoding region of flavivirus genomes: comparative analysis of base pairing probabilities.the prediction of the complete matrix of base pairing probabilities was applied to the 3' noncoding region (ncr) of flavivirus genomes. this approach identifies not only well-defined secondary structure elements, but also regions of high structural flexibility. flaviviruses, many of which are important human pathogens, have a common genomic organization, but exhibit a significant degree of rna sequence diversity in the functionally important 3'-ncr. we demonstrate the presence of secondary struc ...19979214660
automated type specific elisa probe detection of amplified ns3 gene products of dengue viruses.to apply an automated system of nucleic acid hybridisation coupled with the enzyme linked immunosorbent assay (elisa) for the type specific detection of amplification products of dengue viruses.19979215155
affinity selection of a camelized v(h) domain antibody inhibitor of hepatitis c virus ns3 protease.the hcv genome encodes, within the ns3 gene, a serine protease whose activity specifically cleaves the viral polyprotein precursor. proteolytic processing of hcv polyprotein precursor by the viral ns3 proteinase is essential for virion maturation and designing specific inhibitors of this protease as possible anti-viral agents is a desirable and practical objective. with a view to studying both the function of hcv ns3 protease and to designing inhibitors of this enzyme, we directed our interest t ...19979215580
evaluation of four pcr systems amplifying different genomic regions for molecular diagnosis of gb virus c infections.diagnosis of gb virus c (gbv-c) infection is based on rt-pcr methodology that detects genomic viral rna. four sets of primers located in different genomic regions were compared. these primers were used to amplify a reference panel of sera used by the french blood banks, including five positive sera, five negative sera and 10-fold serial dilutions of one positive serum. three sets of primers located in the 5'utr, ns3 and ns5a genomic regions gave comparable results with undiluted sera. when dilut ...19979079759
g(ee): a new hepatitis virus.hepatitis g virus (hgv) is a newly discovered virus of the flavivirus family. it has recently been identified by two independent laboratories. we review the discovery of this virus and summarize the molecular biology techniques that were employed to isolate and sequence hgv although hgv can cause both acute and chronic hepatitis and is found in approximately 1% of u.s. blood donors, it is unclear whether hgv is a major cause of hepatic pathology. at present, it is difficult to screen blood donor ...19979077717
the clinical significance of the detection of hepatitis gbv-c rna in the serum of patients with fulminant, presumed viral, hepatitis.in a significant number of cases of fulminant (presumed viral) hepatitis worldwide, no aetiological agent has been identified. recently, it has been suggested that a newly described flavivirus, gbv-c, is responsible for some of these cases. this study aimed to assess the clinical significance of gbv-c rna, demonstrated by reverse transcriptase-polymerase chain reaction (rt-pcr), in the serum of patients with fulminant non-a to e hepatitis. twenty-three consecutive cases of non-a to e fulminant h ...19979031064
detection of antibodies to a putative hepatitis g virus envelope protein.a flavivirus designated hepatitis g virus (hgv) has been isolated from the serum of patients with non-a-e hepatitis. hitherto, the presence of hgv rna in serum has been detected with the reverse transcription-polymerase chain reaction (rt-pcr) amplification method. we have now developed an immunoassay for antibodies against an hgv protein.19979024375
biology of tick-borne encephalitis virus.tick-borne encephalitis (tbe) virus is an important human pathogen belonging to the genus flavivirus within the family flaviviridae. the genome of the tbe virus is a single-stranded rna (ssrna) molecule of positive polarity encoding all the viral proteins within a single open reading frame (orf). tbe virus shares common physical and genetic characteristic of the flavivirus genus. two subtypes of the tbe virus have been described: (1) european, endemic in many parts of europe and transmitted by i ...19979219644
effect of enforced expression of human bcl-2 on japanese encephalitis virus-induced apoptosis in cultured cells.infection by japanese encephalitis virus (jev), a mosquito-borne flavivirus, causes acute encephalitis in humans and induces severe cytopathic effects in different types of cultured cells. this study attempted to determine whether apoptosis contributes to virus-induced cell death in a culture system by characterizing jev lytic infection in baby hamster kidney bhk-21 cells, murine neuroblastoma n18 cells, and human neuronal progenitor nt2 cells. according to our results, the replication of jev, a ...19979223486
venezuelan equine encephalitis and oropouche virus infections among peruvian army troops in the amazon region of peru.an outbreak of a febrile illness characterized by headache, ocular pain, myalgia, and arthralgia occurred during june 1994 among peruvian army troops in northern peru. on june 14-16, 1994, clinical data and blood samples were obtained from eight soldiers with a febrile illness, and from 26 others who had a history of febrile illness during the past three months. a follow-up blood sample was obtained 107 days later from four of the febrile and seven of the afebrile soldiers. serum samples were te ...19979230800
proteins c and ns4b of the flavivirus kunjin translocate independently into the nucleus.the subcellular locations in infected vero cells of kunjin (kun) virus core protein c and ns4b were analyzed by immunofluorescence (if) and by immunoelectron microscopy using monospecific antibodies. selection of appropriate fixation methods for if showed that both proteins were associated at all times with perinuclear membranes spreading outward in a reticular pattern and they entered the nucleus late during the latent period. subsequently ns4b was also dispersed through the nucleoplasm, while ...19979234944
the yellow fever 17d vaccine virus: molecular basis of viral attenuation and its use as an expression vector.the yellow fever (yf) virus is the prototype flavivirus. the use of molecular techniques has unraveled the basic mechanisms of viral genome structure and expression. recent trends in flavivirus research include the use of infectious clone technology with which it is possible to recover virus from cloned cdna. using this technique, mutations can be introduced at any point of the viral genome and their resulting effect on virus phenotype can be assessed. this approach has opened new possibilities ...19979239300
gb virus c rna in serum, liver, and peripheral blood mononuclear cells from patients with chronic hepatitis b, c, and d.no conclusive data about gb virus c (gbv-c) tropism are available. we have studied the presence of genomic and antigenomic gbv-c rna in serum, liver, and peripheral blood cells of 56 patients with chronic hepatitis b, c, or d virus infection.19979247478
virus isolation from wild-caught mosquitoes during a japanese encephalitis outbreak in kerala in 1996.out of 5357 wild-caught mosquitoes in 163 pools tested for virus using antigen capture elisa and an insect-bioassay (inoculation into toxorhynchites splendens larvae and identification by ifa using je virus-specific monoclonal antibody), 16 flavivirus isolations were made of which 12 (75%) were identified as je virus. of the 12 je virus isolations, 7 were from culex tritaeniorhynchus, 3 from mansonia uniformis and 1 each from ma. indiana and anopheles subpictus. four isolations from mansonia spe ...19979248207
transmission of gbv-c/hgv from drug-addicted mothers to their babies.in 1995, a new flavivirus, gbv-c/hgv was identified. little information is available on the clinical manifestations and epidemiology of gbv-c/hgv infection. we investigated the risk of mother-to-infant transmission in a group of gbv-c/hgv rna positive women and followed up the gbv-c/hgv infected babies.19979252078
dengue virus infectivity depends on envelope protein binding to target cell heparan sulfate.dengue virus is a human pathogen that has reemerged as an increasingly important public health threat. we found that the cellular receptor utilized by dengue envelope protein to bind to target cells is a highly sulfated type of heparan sulfate. heparin, highly sulfated heparan sulfate, and the polysulfonate pharmaceutical suramin effectively prevented dengue virus infection of target cells, indicating that the envelope protein-target cell receptor interaction is a critical determinant of infecti ...19979256277
a 45,000-m(r) glycoprotein in the sendai virus envelope triggers virus-cell fusion.sendai virus envelopes devoid of hemagglutinin-neuraminidase but containing the fusion protein (f-virosomes) were prepared. f-virosomes exhibited discernible serine protease activity at neutral ph. electrophoretic analysis of the protein profile of the f-virosomes under nonreducing conditions, by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing, led to the identification of a previously unknown glycoprotein with a relative molecular weight of 45,000 (45k pr ...19979261357
translation elongation factor-1 alpha interacts with the 3' stem-loop region of west nile virus genomic rna.the conserved 3'-terminal stem-loop (3' sl) of the west nile virus (wnv) genomic rna was previously used to probe for cellular proteins that may be involved in flavivirus replication and three cellular proteins were detected that specifically interact with the wnv 3' sl rna (j. l. blackwell and m. a. brinton, j. virol. 69:5650-5658, 1995). in this study, one of these cellular proteins was purified to apparent homogeneity by ammonium sulfate precipitation and liquid chromatography. amino acid seq ...19979261361
ultrastructure of kunjin virus-infected cells: colocalization of ns1 and ns3 with double-stranded rna, and of ns2b with ns3, in virus-induced membrane structures.the subcellular location of the nonstructural proteins ns1, ns2b, and ns3 in vero cells infected with the flavivirus kunjin was investigated using indirect immunofluorescence and cryoimmunoelectron microscopy with monospecific antibodies. comparisons were also made by dual immunolabelling using antibodies to double-stranded rna (dsrna), the putative template in the flavivirus replication complex. at 8 h postinfection, the immunofluorescent patterns showed ns1, ns2b, ns3, and dsrna located in a p ...19979261387
superinfection exclusion of alphaviruses in three mosquito cell lines persistently infected with sindbis virus.three aedes albopictus (mosquito) cell lines persistently infected with sindbis virus excluded the replication of both homologous (various strains of sindbis) and heterologous (aura, semliki forest, and ross river) alphaviruses. in contrast, an unrelated flavivirus, yellow fever virus, replicated equally well in uninfected and persistently infected cells of each line. sindbis virus and semliki forest virus are among the most distantly related alphaviruses, and our results thus indicate that mosq ...19979261447
schizophrenia, rheumatoid arthritis and natural resistance genes.the strong negative correlation between schizophrenia and rheumatoid arthritis might provide clues as to the aetiology of these two diseases. an immunological explanation has been sought in the hla sector of the major histocompatibility complex, which has been shown to have a role in the development of rheumatoid arthritis. the search for an association between schizophrenia and hla haplotypes, however, has yielded only controversial results. nevertheless, an autoimmune aetiology is still suspec ...19979264173
expression of the dengue virus structural proteins in pichia pastoris leads to the generation of virus-like particles.we have expressed cdna encoding the dengue virus structural proteins in pichia pastoris by chromosomal integration of an expression cassette containing the dengue virus structural genes (cprme). the yeast recombinant e protein migrated during sds-page as a 65 kda protein when analysed by western blotting and radioimmunoprecipitation, which is the expected molecular mass for correctly processed and glycosylated e protein. treatment with endoglycosidases showed that the recombinant e protein was m ...19979266980
expression of immunoglobulin superfamily cell adhesion molecules on murine embryonic stem cells.the expression of cell adhesion molecules of the ig superfamily (ig-cam) were examined on embryonic stem (es) cells during culture in vitro. es cells maintained an undifferentiated phenotype when cultured in the presence of leukemia inhibitory factor (lif) or with fibroblast feeder cells; > 90% of cells reacted positively to an antibody (ecma-7) that marks undifferentiated es cells. using flow cytometry, high concentrations of icam-1, vcam-1, and ncam antigens were detected on undifferentiated e ...19979282991
first record in america of aedes albopictus naturally infected with dengue virus during the 1995 outbreak at reynosa, mexico.mosquito collections were conducted during a dengue outbreak in reynosa, tamaulipas, mexico, july-december 1995. a total of 6694 adult mosquitoes (four genera and nine species) were captured, of which 2986 (78.3% females and 21.7% males) were aedes albopictus and 2339 (39.7% females and 60.3% males) were ae.aegypti. these two species comprised 84.2% of the total collection. specimens were grouped into pools, nearly 50% of them processed for detection of virus by cythopathic effect in c6-36 and v ...19979430106
vertical transmission of dengue.dengue, an important mosquito-borne flavivirus infection, is endemic in southeast asia. we describe two mothers who had acute dengue 4 and 8 days before the births of their infants. one mother had worsening of her proteinuric pregnancy-induced hypertension, liver dysfunction, and coagulopathy and required multiple transfusions of whole blood, platelets, and fresh frozen plasma. her male infant was ill at birth, developed respiratory distress and a large uncontrollable left intracerebral hemorrha ...19979431381
specific rna aptamers to ns3 protease domain of hepatitis c virus.in order to isolate rna aptamers that bind specifically to ns3 protease domain (delta ns3) of hepatitis c virus, we carried out in vitro selection procedure using rna pool that had 30 n random core region. after repeating nine cycles of selections and amplifications, a pool of rnas that bind specifically to the delta ns3 were selected. a comparative analysis of 45 clones that were isolated from 9th cycle revealed three main classes that contain the conserved loop sequences ganugggac. moreover, t ...19979586087
comparison of elisa and hi for detection of antibodies against wesselsbron disease virus.a two-graph receiver operating characteristic analysis was done to determine the optimal cut-off value of an indirect enzyme-linked immunosorbent assay (elisa) for detection of antibodies to wesselsbron disease (wsl) virus. when elisa and haemagglutination-inhibition (hi) results of wsl-positive and wsl-negative control sheep sera were compared, the sensitivity of elisa was 97.9% and that of hi, 87.5%, while the specificity of elisa and hi were 95.7% and 100%, respectively. the elisa's superior ...19979551475
the epidemiology of louping-ill, a tick borne infection of red grouse (lagopus lagopus scoticus).the epidemiology of louping-ill in red grouse was studied in northern britain concentrating on the possible role of other species and mechanisms of disease persistence. this tick borne viral disease caused heavy mortality in red grouse, particularly chicks. louping-ill induced mortality reduced the strength of the density dependence that generates the tendency of grouse populations to cycle and in some populations may cause population sinks. four routes of transmission were examined and non-vira ...19979802086
ilheus virus (flaviviridae, flavivirus) is closely related to japanese encephalitis virus complex.the ilheus (ilh) virus has long been known to belong to group b of the arboviruses. previous attempts to relate it to existing serogroups within the flavivirus genus using conventional serological techniques such as hemagglutination inhibition, neutralization and complement fixation tests have been inconclusive. we have first used denaturing gel electrophoresis to estimate the molecular weight of immunoprecipitated radiolabeled viral proteins and the cross-reactivity among ilh proteins and hyper ...19979612722
human disease caused by an arbovirus closely related to ilheus virus: report of five cases.we report five cases of human disease caused by arbovirus in 5 patients from the state of são paulo, brazil, residing in the municipalities of osasco, atibaia, guarujá, and the capital são paulo, respectively. one of the patients resides in são luis, capital of the state of maranhão. the sites of infection probably were the states of paraná and goiás, both in cave regions, the state of amazonas, and rondônia in two cases. laboratory tests for malaria were negative and 1 patient showed a positive ...19979612726
gb virus c/hepatitis g virus (gbv-c/hgv) infection in chiang mai, thailand, and identification of variants on the basis of 5'-untranslated region sequences.by using reverse transcription and pcr for ns3 and 5'-untranslated regions (5'utr) of the viral genome, prevalence of gb virus c/hepatitis g virus (gbv-c/hgv) infection in chiang mai, thailand, was studied. high prevalence of gbv-c/hgv infection was observed among intravenous drug users (32%) and hemodialyzed patients (25%). the prevalence was also considerably high among patients with chronic liver disease, such as chronic hepatitis (9%), liver cirrhosis (12%) and hepatocellular carcinoma (10%) ...19979672605
studies on the serological cross-reaction between dengue and japanese encephalitis.antibody responses of sero-confirmed flavivirus-infected patients were investigated by hemagglutination-inhibition (hi) tests against acute phase sera (s1) and convalescent phase sera (s2) using je virus (jev) jagar# 01 strain antigen (j-ag) and dengue virus (dv) type 1 hawaiian strain antigen (d-ag). analysis of the test results showed that depending on the combinations of hi responses to both antigens, the sero-confirmed patients could be divided into five classes: primary je, secondary je, pr ...199710592825
[detection of flaviviruses by reverse-transcription polymerase chain reaction with universal primer set].for the purpose of early and rapid diagnosis of flavivirus infection, the universal primer set was selected on the ns1 gene. another five different internal primers were selected on the ns1 genes of den1, 2, 3, 4 and jev. with the universal primer set designed, the ns1 fragment about the size of 413 bp and with the five internal primers, the ns1 fragments about the sizes of 262 bp (den1), 189 bp (den2), 392 bp (den3), 97 bp (den4) and 323 bp (jev) were amplified respectively. the reverse transcr ...199715617345
[the cloning and sequence analysis of cdna of the partial e genomic region of dengue type 4 virus from a chinese patient].the partial envelope (e) protein gene of dengue virus type 4 (dv4), derived from the serum of a patient with dengue fever in an epidemic during october 1993 in guangdong province of china, was cloned and sequenced. dv rna was converted to cdna by reverse transcription with random primers before the polymerase chain reaction using dv4 specific primers was performed. the amplified product of 421bp was subsequently filled in 3' recessed ends, isolated, purified and inserted into puc18 and puc19 pla ...199715619909
[new hepatitis viruses]serum obtained from a surgeon (with the initials gb) with acute icteric hepatitis, permited the passages of two virus to tamarins; furthermore was possible to detect anti-bodies against the putative epitope of this viruses, designed gbv-a and gbv-b in several human populations; many years after that two different researchers teams identified a new virus gbv-c or hvg, based on very similar aminoacid sequence of both.the role of gb-viruses and hepatitis g virus in human pathology is not completely ...199712221439
[cloning and sequencing of cdna in ns3 region of chinese hepatitis g virus isolated from henan province].to study the genetic characteristics of non-structural region 3 of hgv in china, a hgv-rna positive sample was collected from henan. hgv rna was extracted and amplified by rt-nested-pcr. we got four overlap fragments and they were cloned into plasmid vector pcdna ii. the cdna was sequenced by the sanger's method. nucleotide homology between henan strain and other reported hgv isolates (pnf2161, r10291, gbv-c) was 85.7% to 93.8% over the 2137 nucleotides examined. comparison of amino acid sequenc ...199812515161
[detection of hepatitis g virus infection among clinical patients with hepatitis/liver diseases in china by reverse transcription-nested polymerase chain reaction].according to two highly conserved genome sequences within the helicase(ns3) region and 5'-uncoding(5' utr) region, we designed two sets of primer pairs to detect hgv rna by rt-nested pcr in order to study hgv infection in chinese population. three hundred and fifty-four serum specimens of various liver diseases were collected from beijing, qin huangdao and henan areas. seventy-nine out of 354(22.3%) specimens were hgv rna positive. among 254 known clinical hepatitis/liver disease samples, 50(19. ...199812515201
[identification of hepatitis c or/and g virus rna in one tube by reverse transcription nested polymerase chain reaction].hepatitis c and g viruses belong to the flaviviridae family. they have similar modes of transmission. the dual infection of hgv and hcv were reported. a simultaneous detection for hcv or/and hgv was established by reverse transcription nested polymerase chain reaction(rt-nested pcr). the primers were derived from the 5' non-coding region of hcv and ns3 region of hgv, and the length of the pcr product was between 170 bp and 300 bp. rt-nested pcr can be finished in one test tube and hgv and/or hcv ...199812515202
[sequencing and analysis of the ns5 region of hgv/gbv-c gene].to study the genomic organization of non structural region 5 of hgv in china, 186 nucleotides of ns5 region of hgv were amplified, cloned and sequenced. the data were analyzed with computer programs. the results indicated that the gene sequence homology between 2 hgv isolates in this study was 95.2%. the comparison of these 2 isolates and 3 foreign isolates reported previously showed that the sequence homology was in the range of 84.4% to 92.4%, and was obvious by divergent from the foreign isol ...199812526350
[japanese encephalitis: an exceptional imported arbovirus]. 19989779048
tick-borne encephalitis and its prevention in hungary.tick-borne encephalitis (tbe) has been registered in hungary since 1977. in the last four years a moderate decrease of cases was observed. most cases belong to the age group of 30-39 years, and the number of males is twice as high as that of the females among the tbe cases. the efficacy of tbe vaccination was proven also in field trials. the use of the specific hyperimmune gamma-globulins for postexposure prophylaxis is effective. the need to create an international standard for tbe vaccine is d ...19989769651
yellow fever 17d vaccine virus isolated from healthy vaccinees accumulates very few mutations.the live attenuated yellow fever (yf) vaccine strain 17d is one of the safest vaccines in use today with only 22 cases of reversion to virulence documented from over 300 million doses administered. we have isolated virus in cell culture from sera of six volunteers who received 17d vaccine and found that very few nucleotide mutations were detected in the consensus sequence of the entire genome of each of the serum viruses. moreover, most of these mutations accumulated in the non-structural protei ...19989712515
trans-complementation of flavivirus rna polymerase gene ns5 by using kunjin virus replicon-expressing bhk cells.a bhk cell line persistently expressing a kunjin (kun) virus replicon rna (repbhk, similar to our recently described me/76neo bhk cell line [a. a. khromykh and e. g. westaway, j. virol. 71:1497-1505, 1997]) was used for rescue and propagation of kun viruses defective in the rna polymerase gene (ns5). a new infectious full-length kun virus cdna clone, flsdx, prepared from our previously described cdna clone pakun (a. a. khromykh and e. g. westaway, j. virol. 68:4580-4588, 1994) and possessing app ...19989696822
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 ...19989638813
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 ...19989533098
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 ...19989525632
prevalence of hepatitis g virus rna in human immunodeficiency virus type 1-positive intravenous drug users.the aim of this study was to evaluate the prevalence of the new human flavivirus hepatitis g virus (hgv) in italian intravenous drug users (idus) and its interaction with human immunodeficiency virus type 1 (hiv-1) and hepatitis c virus (hcv).199810195238
antigenic relatedness of selected flaviviruses: study with homologous and heterologous immune mouse ascitic fluids.the antigenic relationship of 9 flaviviruses, yellow fever (yf), wesselsbron (wsl), uganda s (ugs), potiskum (pot), west nile (wn), banzi (ban), zika (zk), dengue type 1 (den-1) and dengue type 2 (den-2), was assessed by cross-haemagglutination-inhibition (cross-hi) and cross-complement fixation (cross-cf) reactions between each of the viruses and their homologous immune mouse ascitic fluids. titre ratios were calculated using the heterologous and homologous titres. cross-cf reactions revealed w ...199810436653
[molecular biology of dengue virus].in venezuela the problem of dengue infection has become worst during the last decade, turning the country into an hyperendemic region where three of the four serotypes co-circulate. the dengue has become a problem of public health, so the knowledge of the virus, its life cycle and characteristics, as well as the different aspects related with its biology are extremely important to fight the virus and for the develop of a vaccine. in a general way, the present work describes different aspects rel ...199810030047
[laboratory diagnosis to dengue virus infections].currently, laboratory diagnosis of dengue virus infection has a special importance because of its emerging character, showing a great geographic propagation of viral activity through out the american continent. in general, the laboratory diagnosis of dengue infections is similar to other human infecting viruses, the difference and difficulty of the process lies in the cross reaction activity with other flavivirus that can co-exist in the same region. the effectiveness of the diagnosis depends on ...199810030051
[study of the antigenic structure of tick-borne encephalitis virus using synthetic peptides].a number of peptides, fragments of the envelope protein e of the tick-borne encephalitis virus (sofjin strain), were synthesized. their binding to the polyclonal antiserum to protein e was studied. rats were immunized with both the free peptides and their klh-conjugates, and the resulting antisera were tested for their reactivity toward protein e and for their neutralizing activity toward the virus in cell culture. the only peptide corresponding to the 98-113 sequence of protein e was shown to b ...199810335405
response to je vaccine among hiv-infected children, bangkok, thailand.since 1990, japanese encephalitis (je) vaccine has been part of epi in northern thailand, where there is a high prevalence of je and hiv infection. to evaluate the immunogenicity and safety of je vaccine among hiv-infected children, we conducted a retrospective study of hiv-infected and uninfected children who received 2 doses of je vaccine at 12 months of age. pre- and post-immunization plasma specimens were tested by plaque reduction neutralization for antibody levels to je and dengue(1-4) vir ...199810437937
targets for inhibition of hepatitis c virus replication.considerable progress has been made in characterizing the proteins involved in hepatitis c virus (hcv) replication, despite the lack of a cell culture system. a number of systems have been developed to examine the processes involved in viral replication, including the initiation and processing of the viral proteins required for rna replication, the unwinding activities of the rna helicase and the synthesis of rna by the viral polymerase. these processes have been examined using individually clon ...199810726058
the hepatitis c virus ns3 proteinase: structure and function of a zinc-containing serine proteinase.the hepatitis c virus (hcv) ns3 protein contains a serine proteinase domain implicated in the maturation of the viral polyprotein. ns3 forms a stable heterodimer with ns4a, a viral membrane protein that acts as an activator of the ns3 proteinase. the three-dimensional structure of the ns3 proteinase complexed with an ns4a-derived peptide has been determined. the ns3 proteinase adopts a chymotrypsin-like fold. a beta-strand contributed by ns4a is clamped between two beta-strands within the n term ...199810726060
[detection of hgv ns5 antigen in liver tissue of patients with chronic liver disease].to investigate the existence of hepatitis g virus (hgv) in liver tissue.199811038810
vaccination against tick-borne encephalitis virus, a flavivirus, prevents disease but not infection, although viremia is undetectable.by adoptive transfer of sera or immunoglobulin preparations, vaccine-induced protection against tbev has been demonstrated to be mediated by antibodies to the surface protein of tbev, glycoprotein e. nevertheless, the mechanism of vaccine-induced protection against tbev remains unclear. protection by e antibodies without in vitro neutralization was shown by one group, whereas others found a correlation between protection in vivo and neutralization in vitro. here, the authors confirm in a mouse m ...19989682362
low prevalence of hepatitis g virus antibodies in glomerular diseases.a possible agent for human non-a-e hepatitis has been identified and named hepatitis g virus (hgv). hgv is also a flavivirus, and the clinical characteristics and risk factors of hgv infection may be similar to those of hepatitis c virus infection. hepatitis c virus infection may manifest as a primary glomerulonephritis. the aim of this study is to evaluate the prevalence of serum hgv rna in 98 adult patients with biopsy-proven glomerular diseases. we found that only 3 patients (3%) out of 98 wi ...19989689165
identification of specific nucleotide sequences within the conserved 3'-sl in the dengue type 2 virus genome required for replication.the flavivirus genome is a positive-stranded approximately 11-kb rna including 5' and 3' noncoding regions (ncr) of approximately 100 and 400 to 600 nucleotides (nt), respectively. the 3' ncr contains adjacent, thermodynamically stable, conserved short and long stem-and-loop structures (the 3'-sl), formed by the 3'-terminal approximately 100 nt. the nucleotide sequences within the 3'-sl are not well conserved among species. we examined the requirement for the 3'-sl in the context of dengue virus ...19989696848
[preparation and properties of monoclonal antibodies to tick-borne encephalitis viral nonstructural proteins].hybridomas secreting monoclonal antibodies (mab) to tick-borne encephalitis (tbe) virus are obtained. immunodiffusion showed that 3 mabs to tbe protein ns3 belong to class igm and the rest to igg1. mabs to tbe protein ns1 were tested in hemagglutination inhibition, complement fixation, neutralization, and protection tests. only 1 hybridoma produced mab specific for protein ns1 of tbe strain sofyin, the rest reacted with the common antigenic determinants of nonstructural tbe complex.19989702814
epidemiology of the hepatitis c virus.according to who estimations, about 3% of the world population may be infected with the hepatitis c virus. the relative prevalences of subtypes of this virus vary in different geographic areas. the main known routes of transmission are parenteral; intravenous drug abuse, contaminated injection devices and receipt of unscreened blood. sexual, vertical, household and nosocomial transmissions may occur, but seem to be rare. the risk of screened blood or blood products is now almost eliminated, but ...19989704437
a rapid fluorescent focus inhibition test for detection of neutralizing antibodies to tick-borne encephalitis virus.tick borne encephalitis (tbe), is endemic in several countries in central and northern europe, in the baltic states and in russia. vaccination has been shown to lower efficiently the number of cases of this potentially very serious disease. however, the possibility to assess the neutralizing antibody response after clinical disease or vaccination has been hampered by the lack of easy and specific tests. we developed a rapid fluorescent focus inhibition test (rffit) and compared it with a standar ...19989705177
design of selective eglin inhibitors of hcv ns3 proteinase.hepatitis c virus (hcv) infection is a major health problem that leads to cirrhosis and hepatocellular carcinoma in a substantial number of infected individuals, estimated to be 100-200 million worldwide. unfortunately, immunotherapy or other effective treatments for hcv infection are not yet available, and interferon administration has limited efficacy. different approaches to hcv therapy are being explored, and these include inhibition of the viral proteinase, helicase, and rna-dependent rna p ...19989708981
detection in chimpanzees of a novel flavivirus related to gb virus-c/hepatitis g virus.infection with hepatitis g virus (hgv) or gb virus-c (gbv-c) is widely distributed in human populations. viruses related to gbv-c/hgv have been recovered from several new world primate species, including tamarins, owl monkeys and marmosets. to understand more about the relationship between gb viruses and their hosts, we used primers from the 5' non-coding (5'nc), non-structural 3 (ns3) and ns5 regions in nested polymerase chain reactions to screen for related viruses infecting non-captive chimpa ...19989714234
mutation in ns5 protein attenuates mouse neurovirulence of yellow fever 17d vaccine virus.the 17d-204 vaccine manufactured in south africa (17d-204-sa) and a large plaque variant (17d-lp) derived from it were highly virulent in adult mice. the ld50 of 17d-lp virus was 0-2 p.f.u. for mice following intracerebral inoculation. in comparison, a medium plaque variant derived from 17d-lp, termed 17d-mp virus, was found to be attenuated in adult mice following the same route of inoculation (> 10(4) p.f.u./ld50). replication of 17d-mp virus was decreased in infected mouse brains compared to ...19989714237
establishment and characterization of japanese encephalitis virus-specific, human cd4(+) t-cell clones: flavivirus cross-reactivity, protein recognition, and cytotoxic activity.we analyzed the cd4(+) t-lymphocyte responses of two donors who had received japanese encephalitis virus (jev) vaccine 6 or 12 months earlier. bulk culture proliferation assays showed that peripheral blood mononuclear cells (pbmc) responded to jev antigens (ag) but also responded at lower levels to west nile virus (wnv) and dengue virus type 1, 2, and 4 (d1v, d2v, and d4v, respectively) ag. five jev-specific cd4(+) human t-cell clones and one subclone were established from pbmc of these two dono ...19989733842
an advisory committee statement (acs). committee to advise on tropical medicine and travel (catmat). statement on japanese encephalitis vaccine. 19989735509
west nile encephalitis epidemic in southeastern romania.west nile fever (wnf) is a mosquito-borne flavivirus infection endemic in africa and asia. in 1996, the first major wnf epidemic in europe occurred in romania, with a high rate of neurological infections. we investigated the epidemic to characterise transmission patterns in this novel setting and to determine its origin.19989737281
determination of dengue virus serotypes in individual aedes aegypti mosquitoes in colombia.adult aedes aegypti mosquitoes were collected in puerto triunfo, central colombia, where dengue is endemic, during a six month period. viral infection within the head of each individual mosquito was identified by an immunofluorescent assay (ifa) using a flavivirus-specific monoclonal antibody. the dengue virus serotype, present in each flavivirus-positive specimen, was then determined in portions of the remaining thorax using ifas with serotype-specific monoclonal antibodies. among 2065 female a ...19989737600
immune mediated and inherited defences against flaviviruses.flavivirus infection elicits an abundant immune response in the host which is directed against a number of the viral proteins. resistance to flavivirus-induced disease can also be controlled via a non-immune mechanism involving the product of a naturally occurring murine gene, flv.19989741638
the conformation of hepatitis c virus ns3 proteinase with and without ns4a: a structural basis for the activation of the enzyme by its cofactor.hepatitis c virus (hcv) ns3 proteinase activity is required for the release of hcv nonstructural proteins and is thus a potential antiviral target. the enzyme requires a protein cofactor ns4a, located downstream of ns3 on the polyprotein, for activation and efficient processing.19989741640
defective adenoviruses as novel vaccines for the flaviviridae.vaccines against many flaviviruses, such as japanese encephalitis virus (jev), yellow fever virus (yfv) and tick-borne encephalitis virus (tbev), have been successfully used for many years. other diseases such as dengue fever (df) and hepatitis c are still major public health problems as no licensed vaccines are in use.19989741645
high prevalence of gb virus c/hepatitis g virus infection among homosexual men infected with human immunodeficiency virus type 1: evidence for sexual transmission.gb virus c/hepatitis g virus (gbv-c/hgv), a recently discovered orphan flavivirus, is distantly related to hepatitis c virus (hcv). although both gbv-c/hgv and hcv can be transmitted by the parenteral route, their principal modes of transmission and associated risk behaviors may differ. using reverse transcription-polymerase chain reaction, the 5'-noncoding regions of gbv-c/hgv and hcv were amplified from plasma or sera of 209 individuals infected with human immunodeficiency virus type 1 (hiv-1) ...19989746067
development of viremia and humoral and cellular parameters of immune activation after vaccination with yellow fever virus strain 17d: a model of human flavivirus infection.to monitor early and late events of immune system activation after primary and secondary flavivirus infection, 17 healthy persons were vaccinated with the standard 17d vaccine virus strain of yellow fever (yf). twelve of these persons had not received yf vaccine previously and 5 had been vaccinated once at least 10 years before. viremia and various parameters of humoral and cellular immune activation were followed daily for 7 days and weekly thereafter. viremia was detected by reverse transcript ...19989746073
immunoglobulin m-capture biotin-streptavidin enzyme-linked immunosorbent assay for detection of antibodies to dengue viruses.a biotin-streptavidin system was adapted to an igm-capture elisa for detection of dengue antibodies in human sera. to develop this assay, high titers of antibodies to flavivirus were purified by ion-exchange chromatography (deae-cellulose) and labeled with biotin. heavy chain-specific goat anti-human igm was first bound to the wells of a polystyrene microtiter plate, followed by binding of igm in test specimens, and the use of tetravalent dengue antigens (dengue 1-4), biotin-labeled anti-flavivi ...19989749624
identification of brazilian flaviviruses by a simplified reverse transcription-polymerase chain reaction method using flavivirus universal primers.we report a simplified reverse transcription-polymerase chain reaction (rt-pcr) method for identification of brazilian flaviviruses based on the patterns of electrophoretic separation of the amplicons. the rt-pcr was done on the culture fluids of aedes albopictus c6/36 cells infected with brazilian flaviviruses, without previous extraction of viral rna, using flavivirus universal primers that anneal to highly conserved sequences within the nonstructural protein 5 and 3'- non translated region of ...19989749625
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 ...19989770194
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 ...19989770429
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 ...19989614458
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 ...19989621059
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 ...19989621090
[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 ...19989633235
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 ...19989636360
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 ...19989638142
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.19989639948
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 ...19989648367
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 ...19989648368
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