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ultrastructural observations of viral particles within hepatitis c virus-infected human b lymphoblastoid cell line.hepatitis c virus (hcv)-infected tofe cells, a human bone marrow-derived b-cell line, were studied by transmission electron microscopy (tem). we reported the presence of virus-like particles, (vlps) having a diameter of 45 nm on average, within the cytoplasm of hcv-infected cells and their absence in uninfected cells. the vlps were mostly seen in dilated cisternae of endoplasmic reticulum (er) and consisted of an electron-dense core and a membrane envelope with surface projections. in the hcv-in ...19979108618
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
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
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
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
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
rna-protein interactions: involvement of ns3, ns5, and 3' noncoding regions of japanese encephalitis virus genomic rna.the mechanism of replication of the flavivirus japanese encephalitis virus (jev) is not well known. the structures at the 3' end of the viral genome are highly conserved among divergent flaviviruses, suggesting that they may function as cis-acting signals for rna replication and, as such, might specifically bind to cellular or viral proteins. uv cross-linking experiments were performed to identify the proteins that bind with the jev plus-strand 3' noncoding region (ncr). two proteins, p71 and p1 ...19979094618
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
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
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
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
construction of infectious cdna clones for dengue 2 virus: strain 16681 and its attenuated vaccine derivative, strain pdk-53.we identified nine nucleotide differences between the genomes of dengue-2 (den-2) 16681 virus and its vaccine derivative, strain pdk-53. these included a c-to-t (16681-to-pdk-53) mutation at nucleotide position 57 of the 5'-untranslated region, three silent mutations, and substitutions prm-29 asp to val, ns1-53 gly to asp, ns2a-181 leu to phe, ns3-250 glu to val, and ns4a-75 gly to ala. unpassaged pdk-53 vaccine contained two genetic variants as a result of partial mutation at ns3-250. we constr ...19979143286
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
availability of a second upstream aug can completely overcome inhibition of protein synthesis initiation engendered by mrna secondary structure encompassing the start codon.secondary structure analysis of the mrna from a nonproductive construct carrying the nonstructural gene 3 (ns3) of japanese encephalitis virus revealed the presence of a potential 28 nucleotide long stem and loop beginning with the guanine of the initiation codon aug that had a calculated stabilization energy of -13 kcal/mol (delta gfzero). provision of an additional aug along with three codons upstream resulted in complete relief of inhibition. n-terminal amino acid sequence of the recombinant ...19979322762
the sensitive detection and quantitation of antibody to hcv by using a microsphere-based immunoassay and flow cytometry.antibody to hcv core and ns3 was quantified by using a microsphere immunoassay and flow cytometry. antibody to core and ns3 was elevated in the 85 seropositive blood donors tested. the amount of either antibody varied over two logs although greater variation was seen with the antibody to ns3 than was seen with antibody to core. in three documented acute hcv cases, the microsphere assay detected antibody prior to antibody detection using the reference methods. twenty donor samples were indetermin ...19979332816
proteolytic activation of tick-borne encephalitis virus by furin.flaviviruses are assembled intracellularly in an immature form containing heterodimers of two envelope proteins, e and prm. shortly before the virion exits the cell, prm is cleaved by a cellular enzyme, and this processing step can be blocked by treatment with agents that raise the ph of exocytic compartments. we carried out in vivo and in vitro studies with tick-borne encephalitis (tbe) virus to investigate the possible role of furin in this process as well as the functional consequences of prm ...19979343204
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
characterisation of an hcv ns3/ns4a proteinase fusion protein expressed in e.coli using synthetic peptide substrates. 19979450052
frequencies of gb virus c/hepatitis g virus genomes and of specific antibodies in german risk and non-risk populations.the prevalence of the new flavivirus gb virus c/hepatitis virus g (gbv-c/hgv) in different german populations was investigated by detection of viral genomes and anti-e2 antibodies. while blood donors had an overall prevalence of 10.4% there were increased rates for hemophiliacs (54.7%), hemodialysis patients (30.2%), male homosexuals (30.2%) and intravenous drug users (74.4). most gbv-c/hgv positive samples were either viral genome positive or antibody positive, exclusively. samples with the rar ...19979365885
the molecular basis of virulence of the encephalitogenic flaviviruses. 19979367356
analysis of a recombinant dengue-2 virus-dengue-3 virus hybrid envelope protein expressed in a secretory baculovirus system.in a step towards a tetravalent dengue virus subunit vaccine which is economical to produce, highly immunogenic and stable, a hybrid dengue virus envelope (e) protein molecule has been constructed. it consists of 36 amino acids from the membrane protein, the n-terminal 288 amino acids of the dengue-2 virus e protein plus amino acids 289-424 of the dengue-3 virus e protein. it has been engineered for secretory expression by fusion to a mellitin secretory signal sequence and truncation of the hydr ...19979367357
early e-selectin, vcam-1, icam-1, and late major histocompatibility complex antigen induction on human endothelial cells by flavivirus and comodulation of adhesion molecule expression by immune cytokines.expression of e-selectin (elam-1, cd62e) on human umbilical vein endothelial cells significantly increased 30 min postinfection with the flavivirus west nile virus (wnv), was maximal by 2 h postinfection, and declined to baseline levels within 24 h. expression of icam-1 (cd54) and vcam-1 (cd106) was significantly increased by 2 h and maximal at 4 h after infection. p-selectin (cd62p) expression was unaffected by wnv. upregulation occurred earlier than that caused by tumor necrosis factor alpha ( ...19979371591
naked dna vaccines expressing the prm and e genes of russian spring summer encephalitis virus and central european encephalitis virus protect mice from homologous and heterologous challenge.naked dna vaccines expressing the prm and e genes of two tick-borne flaviviruses, russian spring summer encephalitis (rsse) virus and central european encephalitis (cee) virus were evaluated in mice. the vaccines were administered by particle bombardment of dna-coated gold beads by accell gene gun inoculation. two immunizations of 0.5 to 1 microg of rsse or cee constructs/dose, delivered at 4-week intervals, elicited cross-reactive antibodies detectable by enzyme-linked immunosorbent assay and h ...19979371620
trans-complementation of yellow fever virus ns1 reveals a role in early rna replication.mutational analysis of the nonstructural protein 1 (ns1) of yellow fever virus (yf) has implicated it in viral rna replication. to further explore this observation, we sought a method for uncoupling ns1 function from ns1 expression and processing as part of the large yf polyprotein. here we describe a strategy for providing ns1 in trans, utilizing a noncytopathic sindbis virus vector. replication of a defective yf genome containing a large in-frame deletion of ns1 was dependent on functional exp ...19979371625
capillary electrophoresis for purity estimation and in-process testing of recombinant gb virus-c proteins.protein purity estimation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) coupled with scanning densitometry is a critical component in the manufacture of recombinant proteins for commercial diagnostic assays. however, the procedure is time consuming and often difficult to reproduce because commercial dyes that are used for visualizing proteins do not bind in a stoichiometric fashion for all proteins. the present report describes the use of a rapid and dye-independent sds ...19979384714
cotranslational membrane insertion of the serine proteinase precursor ns2b-ns3(pro) of dengue virus type 2 is required for efficient in vitro processing and is mediated through the hydrophobic regions of ns2b.polyprotein processing of dengue virus type 2, a positive strand rna virus, is carried out by the host signal peptidase and a novel two-component viral proteinase of the serine proteinase family, ns2b/ns3(pro), in the endoplasmic reticulum. using an in vitro processing system, we examined the cis and trans cleavages of the 2b/3 and 4b/5 sites by ns2b/ns3(pro), respectively. lysates of bhk-21 cells coexpressing ns2b and ns3(pro) mediated trans cleavage of the 4b/5 site in vitro, and the protease ...19979388208
antibodies protect mice against challenge with tick-borne encephalitis virus (tbev)-infected macrophages.tbev is a flavivirus highly pathogenic for humans. by transfer of antibodies directed to the tbev surface glycoprotein e into mice, immune protection against subsequent inoculation with free tbev particles could be achieved. after natural tbev infection via the skin, however, cells of the monocyte/macrophage lineage were recently demonstrated to represent an important source of local virus replication before viraemia occurs. whether antibodies can protect against virus challenge when contracted ...19979409636
[hepatitis gbv isolated in acute liver failure. successful outcome after liver transplantation].fulminant hepatic failure is a life-threatening condition associated with a mortality of approximately 80 per cent. liver transplantation may be the only life-saving recourse in such cases. the condition can be caused by any of a number of different agencies such as viral infection, or toxic, circulatory or metabolic factors, though in a large proportion of cases the aetiology is unknown. recently, knowledge has accumulated of a new hepatitis virus, hepatitis gb virus (hgbv), a flavivirus remote ...19979411092
amgen hangs hopes on hepatitis c. 19979415879
analysis of the structure and folding of the 3' genomic rna of flaviviruses.the structure of the 3' genomic rna of flaviviruses has been analyzed by thermal melting, and by chemical and enzymatic probing of model rnas. the 3' rna had more transitions than could be assigned to individual stem-loops and a transition in the 40-45 degrees c range was assigned to tertiary structure unfolding. in support of this assignment, mutants designed to destabilize the proposed pseudoknot tertiary structure lose the 40-45 degrees c transition. enzyme cleavage of the rna and chemical pr ...19979478204
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
[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
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
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
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
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
genetic analysis of the yellow fever virus ns1 protein: identification of a temperature-sensitive mutation which blocks rna accumulation.the flavivirus ns1 protein is a highly conserved nonstructural glycoprotein that is capable of eliciting protective immunity. ns1 homodimers are secreted from virus-infected mammalian cells, but the protein is also present at the plasma membrane and in the lumen of intracellular vesicles. based on these properties, it has been speculated that ns1 may function in virus maturation or release. to gain further insight into ns1 function, we used clustered charged-amino-acid-to-alanine mutagenesis to ...19978985349
[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
[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
[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
[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
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
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
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
[protein e 98-113 sequence is a fusion site of tick-borne encephalitis virus with cellular membrane].the synthetic peptide with the conservative 98-113 sequence of protein e of tick-borne encephalitis virus was studied in order to elucidate its role in the functioning of flaviviruses. the peptide was shown to inhibit the in vitro infection of macrophages with the virus. an antibody that specifically binds this peptide was found among the set of monoclonal antibodies produced against protein e. this antibody was found to prevent penetration of the virus into liposomes. a correlation was found be ...19989813732
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
[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
prevalence of hepatitis g-virus infection in alcohol abusing patients with and without liver cirrhosis.hepatitis g (gbv-c/hgv) is an rna-virus belonging to the flavivirus family and is capable of inducing hepatitis in rare cases. its importance as a co-factor in the pathogenesis of liver disease needs to be clarified.19989823622
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
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
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
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
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
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
[japanese encephalitis: an exceptional imported arbovirus]. 19989779048
growth restriction of dengue virus type 2 by site-specific mutagenesis of virus-encoded glycoproteins.the three flavivirus glycoproteins prm, e and ns1 are formed by post-translational cleavage and are glycosylated by the addition of n-linked glycans. ns1 may form homodimers, whereas e may form homodimers, homotrimers or heterodimers (prm-e). modification of these processes by mutagenesis of the proteins has the potential to generate viruses that are restricted in growth and are possible vaccine candidates. using an sv40-based expression system, we previously analysed dimerization and secretion ...19989820138
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
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
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
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
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
[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 ...19989606874
[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 ...19989608228
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 ...19989608667
virus-encoded proteinases of the flaviviridae. 19989603310
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 ...19989557757
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
[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
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
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 ...19989656998
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 ...19989657950
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 ...19989657959
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 ...19989658369
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 ...19989668049
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 ...19989554270
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