| [reappearance of dengue in new caledonia from 1985 to 1988]. | from 1971 to 1980, dengue outbreaks occurred in new-caledonia due to dengue viruses type 2, 1 and 4 successively. after an eclipse of four years, dengue reappeared in 1985 through 1988. out of 109 cases confirmed by virus isolation, dengue serotypes 1, 2, 3 and 4 caused 15, 23, 17 and 54 cases respectively; in 28 other cases, the flavivirus type could not be identified and in 26 cases an alphavirus (ross river) was pointed out. the den 3 virus, unknown in new-caledonia before 1985, was discretel ... | 1990 | 1982249 |
| the effect of chloroquine prophylaxis on yellow fever vaccine antibody response: comparison of plaque reduction neutralization test and enzyme-linked immunosorbent assay. | weekly oral chloroquine prophylaxis for malaria has been associated with impaired antibody response to intradermal rabies vaccination. experimental data indicate that chloroquine may inhibit yellow fever virus in vitro, yet there has been no clinical evidence to suggest that antibody response to yellow fever vaccine is impaired by concomitant oral administration of chloroquine. a prospective trial was undertaken to evaluate the antibody response to yellow fever 17d vaccine (connaught laboratorie ... | 1991 | 1996743 |
| ph-dependent fusion of tick-borne encephalitis virus with artificial membranes. | ph-dependent fusion of tbe virus with artificial membranes was effective at slightly acidic ph with maximum at 6.4. the influence of various changes in e protein conformation on fusion process was studied. | 1991 | 2048972 |
| california serogroup and powassan virus infection of cats. | one hundred and seventy five sera from cats in ontario, canada, were tested for hemagglutination inhibition (hi) antibodies to three arboviruses; namely, powassan (pow) of the flavivirus serogroup, and snowshoe hare (ssh) and jamestown canyon (jc) viruses of the california (cal) serogroup. all sera were negative for antibodies to pow virus. twelve cats possessed cal serogroup antibodies including 3 with antibodies to ssh alone, 6 with antibodies to jc alone, and 3 with antibodies to both ssh and ... | 1987 | 2825952 |
| protection of mice against yellow fever virus encephalitis by immunization with a vaccinia virus recombinant encoding the yellow fever virus non-structural proteins, ns1, ns2a and ns2b. | recent evidence of a protective immune response to the flavivirus non-structural protein, ns1, has suggested its incorporation into possible recombinant vaccines. the region of the 17d yellow fever virus (yfv) genome encoding the c terminus of envelope glycoprotein and extending to the n terminus of non-structural protein ns3 (ns1-ns2a-ns2b; nucleotides 2030 to 4940) was expressed in vaccinia virus and physical and immunogenic properties of the ns1 moiety were studied. recombinant ns1 protein, a ... | 1990 | 2144016 |
| the 5'-terminal non-coding region of murray valley encephalitis virus rna is highly conserved. | the 5' non-coding region of the genomes of 11 isolates of murray valley encephalitis virus from australia and papua new guinea were examined by primer extension sequencing. although the 5' non-coding region of all isolates was found to be highly conserved, three isolates were significantly different in that they contained extra uridine residues. two of these isolates from papua new guinea contained an extra uridine residue, nominally positioned after nucleotide 54, which was absent from all but ... | 1990 | 2154536 |
| nucleotide sequence of dengue 2 rna and comparison of the encoded proteins with those of other flaviviruses. | we have determined the complete sequence of the rna of dengue 2 virus (s1 candidate vaccine strain derived from the pr-159 isolate) with the exception of about 15 nucleotides at the 5' end. the genome organization is the same as that deduced earlier for other flaviviruses and the amino acid sequences of the encoded dengue 2 proteins show striking homology to those of other flaviviruses. the overall amino acid sequence similarity between dengue 2 and yellow fever virus is 44.7%, whereas that betw ... | 1988 | 2827375 |
| evidence that the mature form of the flavivirus nonstructural protein ns1 is a dimer. | evidence is presented which indicates that the dengue-2 virus nonstructural protein ns1 (soluble complement fixing antigen) exists in infected bhk and mosquito cell cultures as part of a stable oligomer. identification of the dissociation products of the isolated oligomer and comparison of the number of n-linked glycans in native and denatured ns1 is consistent with the idea that the high-molecular-weight form of ns1 is a homodimer. by analyzing lysates of bhk cells infected with st. louis encep ... | 1988 | 2827377 |
| persistence of encephalitogenic arboviruses in brain cell culture. brief report. | virus recovery from brain cultures of mice infected with either semliki forest and/or langat depended on the time interval between inoculation of either virus. mixed infections may alter the course of a disease. | 1987 | 2827614 |
| flaviviruses and bone marrow failure. | | 1990 | 2160551 |
| conserved elements in the 3' untranslated region of flavivirus rnas and potential cyclization sequences. | we have isolated a cdna clone after reverse transcription of the genomic rna of asibi yellow fever virus whose structure suggests it was formed by self-priming from a 3'-terminal hairpin of 87 nucleotides in the genomic rna. we have also isolated a clone from cdna made to murray valley encephalitis virus rna that also appears to have arisen by self-priming from a 3'-terminal structure very similar or identical to that of yellow fever. in addition, 3'-terminal sequencing of the s1 strain of dengu ... | 1987 | 2828633 |
| [flavivirus: serological survey in horses from the tandil area]. | sera from 282 equines from tandil country and surroundings were investigated searching for hemagglutination inhibition (hi), complement fixation (cf), and neutralizing (nt) antibodies against three flavivirus:ilheus, st. louis encephalitis, and yellow fever from the togaviridae family. sera were collected between 3-20-79 and 11-25-80 from 10 different places in tandil and ayacucho countries. animals ranged from 45 days to 27 years old. forty nine of them reacted with one or more flavivirus by hi ... | 1985 | 2829272 |
| sequence and secondary structure analysis of the 5'-terminal region of flavivirus genome rna. | the 5'-terminal noncoding region sequences were determined for the genome rnas of seven strains of st. louis encephalitis virus (slev) and one strain of west nile virus (wnv) using a single synthetic cdna primer complementary to the 5'-terminus of the coding region of a strain of wnv rna. the 5'-terminal sequences obtained for the slev and wnv rnas were compared with published sequences for yellow fever virus (yfv), murray valley encephalitis virus (mvev), and dengue virus. while only short regi ... | 1988 | 2829420 |
| a rapid dot immunoassay for the detection of serum antibodies to eastern equine encephalomyelitis and st. louis encephalitis viruses in sentinel chickens. | a dot enzyme-linked immunosorbent assay utilizing a novel membrane, polyvinylidene difluoride, is described. this assay was developed for the rapid detection of serum antibodies to eastern equine encephalomyelitis virus and st. louis encephalitis virus in sentinel chickens. antigens were spot-filtered through the membrane. membranes were dipped into small vials of sera. antigen-antibody complexes were detected with enzyme-conjugated antiglobulin which, when exposed to substrate, produced a color ... | 1988 | 2829636 |
| heterologous flavivirus infection-enhancing antibodies in sera of nigerians. | human sera collected from nigerians were examined for plaque reduction neutralizing and infection-enhancing antibodies against dengue 2, yellow fever, and west nile viruses. neutralization tests showed that 17 of 19 sera contained flavivirus neutralizing antibody; 11 were positive to all 3 viruses, 5 to dengue and yellow fever, and 1 to dengue virus only. two sera had no detectable neutralizing antibody to any of the flaviviruses. enhancement assays showed that 17 flavivirus neutralizing antibod ... | 1988 | 2829637 |
| the status of dengue fever virus in south africa--serological studies and diagnosis of a case of dengue fever. | to assess the possibility of a dengue epidemic occurring in south africa 3 groups of survey sera and 2 groups of patients' sera, from a dengue high risk area of south africa, were tested for antibodies to several flaviviruses. 3.8% (75/1951) of the survey sera and 9.2% (26/282) of the patients' sera had haemagglutination inhibition antibodies to one or more of the flaviviruses tested. one of 1951 survey sera had a spectrum of complement fixation antibody consistent with a primary dengue infectio ... | 1987 | 2832982 |
| antigenic analysis of west nile virus strains using monoclonal antibodies. | seventeen monoclonal antibodies (mabs) were prepared against the flavivirus west nile strain h442. while the majority of these were specific for the major envelope protein, mabs directed against the ns1 and ns4a nonstructural proteins were also identified. the mabs were tested by indirect immunofluorescence against 16 southern african west nile (wn) isolates, representative strains from the two main wn antigenic groups and several viruses from other flavivirus complexes. the mab reactivities ran ... | 1988 | 2833205 |
| [the possibility of preparing a live vaccine against tick-borne encephalitis from malay langat virus tp-21]. | | 1989 | 2560847 |
| translation mapping with the flavivirus kunjin: gene order and anomalies in translation of ns5. | kunjin (kun) virus-infected cells were synchronized in translation by reversal of hypertonic inhibition; cells were then pulse-labelled with [35s]methionine. electrophoretic analyses defined the sequence of incorporation of label into all the known kun gene products shown previously to be unique and unrelated. gp44 or ns1 was inadequately labelled for analysis and was assumed to be translated sequentially after e in the polyprotein sequence. the relationship of the kun gene order obtained by tra ... | 1988 | 2837017 |
| [morphological study of omsk hemorrhagic fever (ohf) virus with the electron microscope]. | morphological characterization of ohf virus was studied by means of thin section electron microscopy in the brains of mice infected with omsk hemorrhagic fever virus. the crystals, microvesicles, vacuoles and as beehive structures were observed in the virus-infected cells. the possible relationship between the characteristic structures and virus morphogenesis is discussed. it is indicated that these characteristic structures may be important to morphological characterization of ohf virus. | 1989 | 2561476 |
| murray valley encephalitis virus field strains from australia and papua new guinea: studies on the sequence of the major envelope protein gene and virulence for mice. | we have compared the nucleotide sequence of the gene encoding the major envelope (e) protein of a number of murray valley encephalitis virus (mve) isolates from australia and papua new guinea (png). the isolates, from widely separated geographic regions, were from four fatal human cases, a heron, and six mosquito pools and covered a period of 25 years. the sequences of the australian strains were notable for their similarity, showing not more than 1.7% nucleotide sequence divergence in pairwise ... | 1988 | 2838962 |
| further observations on the mechanism of vertical transmission of flaviviruses by aedes mosquitoes. | as previously observed for dengue viruses, vertical (i.e., transgenerational) transmission of japanese and st. louis encephalitis viruses by aedes albopictus takes place when the fully formed egg, enclosed in the chorion, is oviposited. the demonstration of such a mechanism for three flaviviruses suggests that vertical transmission of all mosquito-borne flaviviruses may occur in the same manner. | 1988 | 2840833 |
| [serologic study of arbovirus in 2 localities of the juventud island]. | a serologic study is made in two population groups in the isle of youth. a total 268 blood samples in blotting paper are subjected to the hemagglutination inhibition technique, using the eastern equine encephalomyelitis, western equine encephalomyelitis, saint louis encephalitis, and dengue 2 viruses; 16% positivity to flavivirus was found. a second serum sample was taken in people positive by the hemagglutination inhibition technique in order to carry out the techniques of complement fixation a ... | 1989 | 2561798 |
| results of arbovirological examination of birds of the family hirundinidae in czechoslovakia. | migratory birds (swallow, hirundo rustica; sand martin, riparia riparia; house martin, delichon urbica) caught in southern moravia (czechoslovakia) in 1984-87 were examined for arbovirus infections. isolation experiments were carried out using blood samples of 183 birds (52 swallows, 107 sand martins, and 24 house martins). the results were negative. serological examinations of 136 birds (36 swallows, 86 sand martins, and 14 house martins) were made by haemagglutination-inhibition test (hit) usi ... | 1989 | 2562171 |
| establishment and characterization of st louis encephalitis virus persistent infections in aedes and culex mosquito cell lines. | persistent infections with st louis encephalitis (sle) virus were established in three mosquito cell lines (aedes albopictus, a. dorsalis and culex tarsalis) and were maintained for over 2 years. all three persistently infected cell cultures shared two features: (i) no overt cytopathic effect and (ii) a relatively high proportion of cells infected (41 to 85%). the aedes persistently infected cultures were resistant to superinfection with the homologous virus but not heterologous viruses. two sig ... | 1988 | 2842432 |
| phenotypes of st louis encephalitis virus mutants produced in persistently infected mosquito cell cultures. | viral mutants that appeared during long-term persistent infections of mosquito cell cultures (aedes albopictus, a. dorsalis and culex tarsalis) with st louis encephalitis virus were characterized. evidence was obtained for the presence of temperature-sensitive mutants in the a. dorsalis and c. tarsalis persistently infected cultures, and small plaque mutants were predominant in all cultures except one of two cell cultures of c. tarsalis. virus from persistently infected a. albopictus cell cultur ... | 1988 | 2842433 |
| protection against japanese encephalitis by inactivated vaccines. | encephalitis caused by japanese encephalitis virus occurs in annual epidemics throughout asia, making it the principal cause of epidemic viral encephalitis in the world. no currently available vaccine has demonstrated efficacy in preventing this disease in a controlled trial. we performed a placebo-controlled, blinded, randomized trial in a northern thai province, with two doses of monovalent (nakayama strain) or bivalent (nakayama plus beijing strains) inactivated, purified japanese encephaliti ... | 1988 | 2842677 |
| interferon-independent increases in class i major histocompatibility complex antigen expression follow flavivirus infection. | infection of tertiary-passaged mouse embryo fibroblasts by four flaviviruses, west nile (wnv), kunjin, murray valley encephalitis and japanese b encephalitis, resulted in a six- to 10-fold increase in the expression of individual h-2k and h-2d class i major histocompatibility complex (mhc) antigens 16 to 48 h after infection. the mechanism(s) by which flaviviruses increased antigen expression has not been fully elucidated, but appears to be mediated partly independently of interferon-beta (ifn-b ... | 1988 | 2844965 |
| comparisons of the pestivirus bovine viral diarrhoea virus with members of the flaviviridae. | the molecular features of bovine viral diarrhoea virus (bvdv), a member of the pestivirus genus currently classified in the togaviridae, were examined for characteristics resembling those of the flaviviridae family. like flaviviruses, bvdv possesses a single-stranded rna genome (approx. 4.3 x 10(6) mr) deficient in a 3' poly(a) tract. this rna has a single open reading frame spanning the length of the genome in the viral rna sense (positive polarity), implying an expression strategy involving th ... | 1988 | 2844971 |
| [chemoprophylaxis and chemotherapy of arbo- and arenavirus infections]. | | 1988 | 2845668 |
| [monoclonal antibodies to flavivirus antigens induced by a vaccinal strain of yellow fever]. | monoclonal antibodies (mabs) yel-2 induced by the vaccine fns dakar yellow fever (yf) virus were characterized for their capacity to enter into serological reactions and to react with heterologous flaviviruses. yel-2 mabs belong to the igg2a class of immunoglobulins, possess the antihemagglutination properties, are active in indirect if test but do not activate complement and have no neutralizing properties. the inability to enter into cft in the presence of antihemagglutinating properties sugge ... | 1988 | 2848367 |
| [modification during experimental flavivirus infection of the formation of a b-cell immunologic memory to heterologous antigen]. | | 1988 | 2848369 |
| occurrence of tick-borne encephalitis (tbe) virus in berlin (west). | the main vector of central european tick-borne encephalitis (tbe), the hard tick ixodes ricinus, is very common in forests of berlin (west) all of which are frequently visited nearby recreation areas. while the presence of the causative agent, a flavivirus, has been demonstrated in all districts of the german democratic republic (gdr) there has been no corresponding investigation concerning berlin (west). in the present study, 4593 unengorged i. ricinus nymphs and adults were collected by the fl ... | 1988 | 2850694 |
| 1987 yellow fever epidemics in oyo state, nigeria: a survey for yellow fever virus haemagglutination inhibiting antibody in residents of two communities before and after the epidemics. | a survey for yellow fever haemagglutination inhibiting antibody was carried out before and after the 1987 yellow fever epidemics in nigeria in two localities in oyo state, namely: ibadan and ogbomosho. a total of 129 sera were collected from the two localities before the epidemic. the overall prevalence of yellow fever hi antibody was 37%. a breakdown of positive sera showed that 30/100 and 18/29 sera tested in ibadan and ogbomosho respectively were positive. there was a higher prevalence of hi ... | 1988 | 2851207 |
| antibody prevalence of st. louis encephalitis virus in avian hosts in los angeles, california, 1986. | a study was conducted to determine the pattern of st. louis encephalitis (sle) virus activity in the avian populations of the los angeles metropolitan area in 1986. in total, 679 birds of 42 species were captured at 7 study sites. the overall prevalence of sle neutralizing (n) antibody of 3% indicated enzootic transmission. antibody prevalences were higher in birds sampled in the central part of the metropolitan area, which was consistent with other epidemiologic data. the use of specific avian ... | 1988 | 2852209 |
| localization of arboviral antigen in brain tissues from patients with encephalitis. | brain tissues from 38 patients with a clinical suspicion of encephalitis or encephalopathy were examined by two immunoenzymatic techniques for the detection of arboviral antigen. group b arboviral antigen was identified in 23 of these tissues. this simple method could be used for the diagnosis of the causal agent of encephalitis. | 1988 | 2852405 |
| production of yellow fever virus proteins in infected cells: identification of discrete polyprotein species and analysis of cleavage kinetics using region-specific polyclonal antisera. | flavivirus proteins are produced by translation of a single long open reading frame and a complex series of cotranslational and post-translational proteolytic cleavages. to study these processing events in yellow fever virus (yf)-infected cells, polyclonal antisera recognizing c, prm, e, ns1, ns2b, ns3, ns4b, and ns5 were generated using peptide and fusion protein immunogens. evidence suggests that production of the structural protein precursors involves rapid cotranslational processing consiste ... | 1990 | 2353452 |
| the importance of autumn rainfall and sentinel flock location to understanding the epidemiology of st. louis encephalitis virus in indian river county, florida. | culex nigripalpus adults were collected from sentinel chickens at 4 sites in indian river co. (irc), florida. chickens located in well drained, open habitats attracted fewer cx. nigripalpus than did those located in a moist, forested area, but the number of mosquitoes collected in the open habitats increased significantly with heavy autumn rainfall. all st. louis encephalitis virus (sle) seroconversions (11/674) during a 7-year period were from chickens located in open, well drained habitats. a ... | 1985 | 2852706 |
| flavivirus vaccines. | diseases caused by flavivirus infection have been a scourge of mankind for over three centuries; with yellow fever, dengue fever and russian spring-summer encephalitis causing epidemics resulting in thousands of fatalities. due to the development of a safe and efficacious live-attenuated vaccine against yellow fever, this disease is no longer such a threat in countries where adequate vaccination is practised. a similarly safe and efficacious inactivated vaccine against central-european tick-born ... | 1988 | 2854336 |
| a study of viral and rickettsial exposure and causes of fever in juba, southern sudan. | patients presenting at the juba teaching hospital, either with fever of undetermined origin or with a clinical cause of fever, gave evidence of exposure to a wide range of viral and rickettsial agents. serological tests showed high antibody levels to flaviviruses (56.9%) and alphaviruses (29.2%), with lesser levels of bunyamweraviruses (3.8%), rift valley fever (2.3%), and sandfly fever (0.75%). flavivirus exposure was significantly associated with clinical evidence of liver disease; repeated ex ... | 1988 | 2855284 |
| clinical and pathological responses of west african dwarf goats (fouta djallon) infected with nigerian strain of wesselsbron virus. | | 1988 | 2855376 |
| molecular biology of the flaviviruses. | an overview of the molecular biology of the flaviviruses is presented. the members of this virus family are enveloped positive-strand rna viruses capable of causing a number of important human diseases. | 1987 | 2856425 |
| characterization of the mesenteronal infection with western equine encephalomyelitis virus in an incompetent strain of culex tarsalis. | interactions of western equine encephalomyelitis (wee) virus are compared with mesenterons of 2 genetically selected susceptible (ws) and refractory (wr) lines of culex tarsalis. both ws and wr females had similar susceptibility when parenterally inoculated with virus, thus it was initially thought that resistance in wr cx. tarsalis was associated with a mesenteronal infection barrier. present data on viral growth in mesenterons dissected from females fed on virus-soaked pledgets suggest that vi ... | 1989 | 2774065 |
| virus-induced decrease in the activity of serum blocking factor(s): a mechanism of activation of the autoreactive t effectors in graft versus host reaction and of controlling t suppressors. | it has been shown that serum blocking factor(s) (sbf) previously detected in normal mice bind(s) to receptors on the surface membranes of virus-induced autoreactive t lymphocytes (artl) and to that of artl activity inhibiting t suppressors (tsar). the interaction of sbf with the receptors is reversible, h-2 restricted and associated with the inhibition of functional activity of the tested t lymphocyte populations. in mice during acute tick-borne encephalitis (tbe), in the course of inapparent in ... | 1985 | 2859760 |
| comparative susceptibility of five species of toxorhynchites mosquitoes to parenteral infection with dengue and other flaviviruses. | five species of colonized toxorhynchites mosquitoes were compared for relative susceptibility to parenteral infection with the four dengue serotypes and st. louis and japanese encephalitis viruses. tx. amboinensis, tx. brevipalpis, tx. rutilus, and tx. splendens were equally susceptible to infection with the dengue viruses, while tx. theobaldi was relatively resistant to infection with those viruses. all five mosquito species were equally susceptible to infection with the encephalitis viruses. t ... | 1985 | 2862802 |
| differential phosphorylation of the nucleoprotein of influenza a viruses. | an analysis of the nucleoprotein (np) of 29 different influenza a viruses by phosphopeptide fingerprinting revealed three prototype patterns. the first, which was a complex pattern consisting of six to seven phosphopeptides, another which was relatively simple consisted of two or three phosphopeptides, and a third one which was complex but was missing the main phosphopeptide shared by the two other patterns. phosphoserine was the only labelled phosphamino acid detected. a tentative deduction of ... | 1989 | 2778438 |
| experimental study of the reproduction of karshi virus (togaviridae, flavivirus) in some species of mosquitoes and ticks. | the strain kaz-816 of karshi virus was isolated in 1976 from h. asiaticum ticks collected in the north of central asia (alma-ata region of the kazakh soviet socialist republic). both ticks and mosquitoes can be vectors of karshi virus as proved experimentally by reproduction of the virus in hyalomma asiaticum and dermacentor daghestanicus ticks and culex pipiens molestus, anopheles atroparvus an aedes aegypti mosquitoes as well as by transmission to newborn mice by the bite of infected mosquitoe ... | 1985 | 2864824 |
| antigen capture elisa for the identification of dengue viruses. | we developed a simple antigen capture enzyme immunosorbent assay (agc-elisa) for identifying dengue (den) virus. the method employed serotype-specific monoclonal antibodies as capture antibodies and an enzyme conjugate of a flavivirus-reactive monoclonal antibody as a detecting antibody. most den virus strains, representing all 4 serotypes isolated from various parts of the tropics, were identical either visually of spectrophotometrically when infected cell culture fluids were used as sources of ... | 1985 | 2867103 |
| blood value changes in flavivirus-inoculated macaca fascicularis monkeys. | blood values were analysed in eighteen cynomolgus monkeys on pre-and post-neurovirulence testing of dengue-2 and yellow fever vaccine viruses, dengue-2 parental and japanese encephalitis viruses. certain changes between blood chemistry, hematology and serology were observed and briefly discussed. | 1986 | 2874612 |
| changes of natural killer cell activity in different mouse lines by acute and asymptomatic flavivirus infections. | effect of certain flaviviruses on the activity of mouse natural killer (nk) cells was investigated using the classical mouse splenocyte system and yac-1 cells for demonstration of nk cell cytotoxicity. infection of mice with langat and west nile (wn) viruses was accompanied by temporary activation of nk cells. in mice infected with tick-borne encephalitis (tbe) virus the stimulation phase of nk cell cytotoxicity on days 2-4 post-infection (p.i.) was followed by suppression of their activity. as ... | 1986 | 2876611 |
| [arbovirus-vector-vertebrate cycles in madagascan forests]. | | 1986 | 2879516 |
| application of enzyme immunoassay on infected cells (eia-ic) for arboviruses. | comparative titrations of alpha-, flavi- and bunyamwera viruses were made by eia-ic and according to cytopathic effect (cpe). specific enzymatic reactions appeared earlier and in higher titres than cpe. the titres of dengue type 1, mayaro, powassan and langat viruses measured by eia-ic were comparable to those measured by intracerebral inoculation of mice. the cross-reactivity testing of eia-ic among alphaviruses (chikungunya, sindbis and mayaro), flaviviruses (japanese encephalitis, murray vall ... | 1986 | 2881468 |
| detection of dengue virus rna using nucleic acid hybridization. | conditions for using slot-blot nucleic acid hybridization to quantitatively detect dengue-2 virus using a radiolabelled cdna probe, pvv17, were determined. as little as 11 plaque-forming units of virus were detected using a hybridization mixture without formamide and performing the test at 70 degrees c. while predominantly serotype-specific using stringent (65 degrees c) washing conditions, the probe detected all four dengue virus serotypes using astringent (28 degrees c) washing conditions. no ... | 1987 | 2881940 |
| identification of flaviviruses by the single-radial-haemolysis test. | | 1986 | 2883117 |
| genetic differentiation of murray valley encephalitis virus in australia and papua new guinea. | the genetic relatedness of ten murray valley encephalitis virus (mve) isolates from australia has been examined by comparing haeiii and taqi restriction digest profiles of cdna to virion rna. the isolates were from the murray valley region of south-eastern australia and from the ord river region of western australia and spanned a period of 23 years (1951-1974). the isolates generated closely similar restriction digest profiles. the extent of similarity suggested that the level of nucleotide sequ ... | 1986 | 2884985 |
| virus isolations from mosquitoes collected during the 1982 japanese encephalitis epidemic in northern thailand. | from 16 june to 15 august, 1982 cdc light traps were used to collect mosquitoes in the province of kamphaengphet, n. thailand. 353,042 mosquitoes comprising 59 species were collected and identified, and 345,173 were placed in pools for attempted virus isolation by inoculation of c6/36 aedes albopictus mosquito cell cultures. viruses were isolated from 63 mosquito pools. these comprised 56 flaviviruses, identified as 35 isolates of japanese encephalitis (je) virus strains, 18 strains of tembusu ( ... | 1986 | 2885948 |
| overwintering mechanisms of mosquito-borne arboviruses in temperate climates. | it can be concluded from the data cited that transovarial transmission is a plausible explanation for the overwintering of mosquito-borne bunyaviruses of the california serogroup. vertical transmission of mosquito-borne flaviviruses could explain the overwintering of this group of viruses, but this is far from having been established. at present, the mechanism by which mosquito-borne alphaviruses pass the winter is obscure. | 1987 | 2891312 |
| temperature-sensitive mutants of japanese encephalitis virus. | ten stable temperature-sensitive mutants of japanese encephalitis virus were isolated after mutagenesis by growth of cloned wild-type virus in the presence of the nucleic acid precursor analogs 5-fluorouracil and 5-azacytidine. mutants were selected which grew at least 100-fold better at 33 degrees c than at 41 degrees c. the 5-fluorouracil was found to be more effective at inducing temperature-sensitive mutations than was 5-azacytidine. analysis of the virus-specific rna and proteins synthesize ... | 1985 | 2410633 |
| in vitro synthesis of japanese encephalitis virus (jev) rna: membrane and nuclear fractions of jev-infected cells possess high levels of virus-specific rna polymerase activity. | japanese encephalitis virus (jev)-specific rnas (including 42s rna) were synthesized in subcellular fractions prepared from infected c6/36 cells. this in vitro rna synthesis essentially required mg2+ and four ribonucleotides, and it was enhanced by k+. the amounts of rna synthesized in vitro (in extracts from jev-infected cells) increased as a function of time after infection. the rna-synthetic activity in nuclear fractions was the highest among three kinds of subcellular fractions. our data sho ... | 1989 | 2816040 |
| terminal sequences of the replicative form of rna of the japanese encephalitis virus. | the 5' and 3' terminal sequences of the replicative form (rf) of rna of a flavivirus, the japanese encephalitis (je) virus, strain ja0ars982, have been determined by in vitro labelling and mobility shift analysis. the plus strand sequence was 5'agaaguuuaucugugugaa...ucuoh3', while the minus strand sequence was 5'agauccuguguucuuccuca...ucuoh3'. these sequences were similar to those of west nile (wn) virus being identical in 12 nucleotides at the 5'terminal of the minus strand, and in the 5'termin ... | 1988 | 2897776 |
| haemagglutination-inhibiting antibodies against arboviruses of the families togaviridae and bunyaviridae in birds caught in southern moravia, czechoslovakia. | a total of 295 birds belonging to 19 species of 7 families of wild passeriformes were examined by haemagglutination-inhibition test. the birds were caught for an international research program "balt" at the time of autumn migration (august-september 1984). their blood sera were examined for antibodies against 6 arbovirus antigens of the genera alphavirus (sindbis-sin) and flavivirus (tick-borne encephalitis-tbe, west nile-wn) and family bunyaviridae (tahyna-tah, calovo-cvo and bhanja-bha). antib ... | 1987 | 2822552 |
| recent advances in the molecular biology of flaviviruses. | | 1986 | 2824939 |
| yellow fever virus proteins ns2a, ns2b, and ns4b: identification and partial n-terminal amino acid sequence analysis. | a series of fusion proteins corresponding to the hydrophobic ns2 and ns4 regions of yellow fever virus (yf) were generated in escherichia coli using trpe fusion vectors. antisera to ns2 and ns4 region fusion proteins recognize virus-specific proteins of 15 and 27 kda, respectively. n-terminal amino acid sequence analysis of the 27-kda protein indicates that the n-terminus of yf ns4b immediately follows a signalase-like cleavage site. additional sequence data generated by microsequence analysis o ... | 1989 | 2922923 |
| characterization of protease cleavage sites involved in the formation of the envelope glycoprotein and three non-structural proteins of dengue virus type 2, new guinea c strain. | amino terminal sequences of the envelope protein e and the three largest nonstructural proteins ns1, ns3, and ns5 of the new guinea c strain of dengue virus type 2 (den-2) were obtained by nucleotide and protein sequencing. clones were prepared containing cdna of den-2 virus in the plasmid puc8. the nucleotide sequences of viral cdna inserts were determined and the cdna of each clone positioned on the flavivirus genomic map by comparison of the deduced amino acid sequence with that of yellow fev ... | 1987 | 2952760 |
| characterization of west nile virus persistent infections in genetically resistant and susceptible mouse cells. ii. generation of temperature-sensitive mutants. | long-term persistent infections were established with the flavivirus, west nile virus (wnv), strain e101, in embryofibroblast cultures derived from susceptible c3h/he and congenic-resistant c3h/rv mice. cultures were initially maintained by weekly subculture at 37 degrees, but at passage 6 sister cultures were shifted to 32 degrees. virus progeny titers were observed to increase after the shift to 32 degrees indicating the possible presence of temperature-sensitive mutants. temperature-sensitive ... | 1985 | 2981450 |
| the isolation of meaban virus, a new flavivirus from the seabird tick ornithodoros (alectorobius) maritimus in france. | seven strains of a new flavivirus, for which the name of meaban virus is proposed, were isolated from the seabird tick ornithodoros (a.) maritimus collected during 1981 and 1982 in nests of herring gulls (larus argentatus) on islands of south brittany, france. the new virus was compared serologically with 65 other flaviviruses including tyuleniy virus and was found to be most closely related to, but different from saumarez reef virus, an agent previously isolated in australia and tasmania. some ... | 1985 | 2982352 |
| peptide mapping of envelope-related glycoproteins specified by the flaviviruses kunjin and west nile. | glycoproteins detected in vero cells infected by the flaviviruses west nile and kunjin were examined by gel electrophoresis and peptide mapping. two major glycoproteins, gp66 and gp54, were observed in west nile virus-infected cells labelled for short time periods with [3h]mannose. a third glycoprotein, gp58, was present in smaller amounts. pulse-labelling experiments suggested that gp66 was a precursor of gp54. peptide mapping of [3h]leucine-labelled gp66, gp54 and the envelope glycoprotein e o ... | 1985 | 2983002 |
| william c. reeves and arbovirus research in australia. | william c. reeves was invited to australia in 1952 to take part in field studies of murray valley encephalitis. the results of his work led to various hypotheses which directed arbovirus research in australia for a generation. that and the people he influenced in australia made him a major figure in the development of australian arbovirus research. | 1987 | 2825554 |
| synthetic peptides derived from the deduced amino acid sequence of the e-glycoprotein of murray valley encephalitis virus elicit antiviral antibody. | we used computer analysis to study hydrophilicity, homology, surface accessibility, molecular flexibility, and secondary structure of the deduced amino acid sequence of the flavivirus envelope (e)-glycoprotein. using the results, we modified the e-glycoprotein antigenic structure proposed by nowak and wengler (1987, virology, 156, 127-137). our model predicts considerable overlaps in the previously defined domains. we have prepared 11 synthetic peptides from the deduced amino acid sequence of th ... | 1989 | 2472704 |
| epitope analysis of strains of japanese encephalitis virus by monoclonal antibodies. | twenty one strains of japanese encephalitis (je) virus, including 16 from india, were compared antigenically on the basis of their reactivity in immunofluorescence (if), haemagglutination inhibition (hi), elisa with captured antigen (eca), and neutralization (n) tests with je monoclonal antibodies (mabs). these mabs represented three domains of distinct epitopes on the envelope protein, designated as hs-1 to 4 (je specific in hi), hx-1 to 5 (flavivirus cross reactive in hi) and nhs-1 to 2 (non-h ... | 1989 | 2482831 |
| arthropod-borne virus zoonosis surveillance in the cape province: 1. prospective serological investigations for virus activity in the beaufort west and middelburg districts during 1981. | in addition to the routine sero-epidemiological surveillance for arthropod-borne viral zoonoses in the cape province carried out by the department of medical microbiology and state health department of virology laboratory, we conducted a prospective serological investigation for virus activity during 1981 in two districts of the province, namely the beaufort west and middelburg districts, which experienced heavy rainfall during the first two months of that year. the approach used was to obtain p ... | 1985 | 2987499 |
| modoc-like virus isolated from wild deer mice (peromyscus maniculatus) in alberta. | small mammals were trapped in northeastern alberta, canada during 1976. blood samples from these animals were tested for virus by inoculation of suckling mice. blood clots from two deer mice yielded isolates of the same virus. the virus was related antigenically to a number of flaviviruses which have been isolated from mammals in central america and north america and was related most closely to modoc virus. physical, chemical, and biological properties of the virus were similar also to those of ... | 1985 | 2987550 |
| experimental infection with murray valley encephalitis virus. pigs, cattle, sheep, dogs, rabbits, macropods and chickens. | a total of 142 young animals including 10 domestic and 14 feral pigs, 12 hereford calves, 12 crossbred and 24 merino lambs, 11 dogs, 8 domestic and 16 feral rabbits, 14 grey kangaroos, 9 agile wallabies and 12 chickens was exposed to infection with 4 strains of murray valley encephalitis virus (mve), mainly using orally infected culex annulirostris mosquitoes. in terms of their viraemic response, the animals were grouped into high (grey kangaroos, rabbits), moderate (pigs, dogs, chickens) and lo ... | 1985 | 2990398 |
| antibody-dependent enhancement of tick-borne encephalitis virus infectivity. | fourteen mouse monoclonal antibodies raised against tick-borne encephalitis virus (tbev) and polyclonal antisera raised against six other flaviviruses, edge hill (ehv), japanese encephalitis (jev), langat (lgtv), louping ill (liv), west nile (wnv) and yellow fever (yfv), were tested for their ability to enhance the replication of tbev in cells of the mouse macrophage-like line p388 d1, and for their reactivity in elisa and haemagglutination inhibition (hi) tests. irrespective of their specificit ... | 1985 | 2991448 |
| sequence analysis of the viral core protein and the membrane-associated proteins v1 and nv2 of the flavivirus west nile virus and of the genome sequence for these proteins. | cell-associated flaviviruses contain the two membrane proteins v3 and nv2 besides the viral core protein v2 whereas extracellular viruses do contain v2 protein and the two membrane proteins v3 and v1. since the v1 protein could not be detected in infected cells it has been suggested that v1 is generated from nv2 by proteolytic cleavage during the release of virus from cells (d. shapiro, w. e. brandt, and p. k. russell (1972), virology 50, 906-911). we have isolated the viral structural proteins ... | 1985 | 2992152 |
| polyadenylic acid sequences in the genomic rna of the togavirus of simian hemorrhagic fever. | since serologic studies have failed to relate the togavirus simian hemorrhagic fever (shf) virus to any currently accepted genus within the togaviridae family, the presence of polyadenylic acid [poly(a)] in the genomic rna was analyzed in view of the different content reported for the two major genera of that family: alphaviruses where poly(a) is 40 to 120 nucleotides long and flavivirus where poly(a) is considered to be absent. oligo(dt)-cellulose chromatography of whole genomic rna from purifi ... | 1985 | 2992158 |
| transcription of infectious yellow fever rna from full-length cdna templates produced by in vitro ligation. | yellow fever (yf) virus is the prototype member of the flavivirus family, a diverse group of human and animal pathogens. a live-attenuated strain of yf virus, called 17d, has been used successfully for human vaccination for more than 50 years. in this report we describe the construction of full-length yf 17d cdna templates that can be transcribed in vitro to yield infectious yf virus rna. because of the instability of full-length yf cdna clones and their toxic effects on escherichia coli, we dev ... | 1989 | 2487295 |
| viral infections of little blue penguins (eudyptula minor) along the southern coast of australia. | serum antibodies to strains of avian paramyxovirus and flavivirus were detected in little blue penguins sampled at port campbell and phillip island, victoria, australia. no antibody to newcastle disease virus (ndv) was detected in 267 sera collected, although one penguin captured for experimental studies had a hemagglutination-inhibition antibody titer of 2(4) to this virus. experimental studies showed that the avian paramyxovirus designated apmv-im and strain v4 of ndv were non-pathogenic for p ... | 1985 | 2993680 |
| conditions for haemolysis by flaviviruses and characterization of the haemolysin. | the 17d vaccine strain of yellow fever virus (yf 17d) was used to establish the optimal conditions for lysis of chick erythrocytes. tissue culture-grown, polyethylene glycol-concentrated virus showed peak activity at ph 5.4 in citrate buffer when incubated at 37 degrees c. a further two- to fourfold increase in titre was obtained by pretreatment of the chick erythrocytes with 250 micrograms/ml trypsin. these conditions were also shown to be optimal for japanese encephalitis (je), west nile (wn) ... | 1985 | 2995565 |
| human antibody response to immunization with 17d yellow fever and inactivated tbe vaccine. | the antibody response against flaviviruses tick-borne encephalitis (tbe), kyasanur forest disease (kfd), murray valley encephalitis (mve), west nile fever (wnf), japanese b encephalitis (je), dengue 2 (den-2), and yellow fever (yf) was studied in humans after administration of an inactivated tbe virus vaccine. individuals were either prevaccinated with 17d yellow fever (experimental group) or without any previous exposure to flaviviruses (control group). the appearance of serum titres of homolog ... | 1985 | 2995571 |
| premortem isolation of saint louis encephalitis virus: case report and implications for hospital and laboratory personnel. | | 1985 | 2995935 |
| powassan viral encephalitis: a review and experimental studies in the horse and rabbit. | powassan virus strain m794, a member of the flavivirus genus known to infect man and animals in canada, was inoculated intracerebrally into rabbits and horses. no clinical signs were observed in rabbits, but widespread encephalitis resulted, characterized by lymphoid perivascular cuffing, lymphocytic meningitis, and lymphocytic choroiditis. in horses, eight days after inoculation, prominent neurological signs occurred and lesions were those of non-suppurative encephalomyelitis, neuronal necrosis ... | 1985 | 2996203 |
| amino-terminal amino acid sequences of structural proteins of three flaviviruses. | n-terminal amino acid sequences of structural proteins of three flaviviruses, yellow fever, st. louis encephalitis, and dengue-2 viruses, have been obtained. the glycoproteins of these three viruses are 52-60% conserved in the region sequenced, depending upon which pair of viruses are compared, and 40% of the amino acids are invariant in all three viruses. thus, flaviviruses are closely related and have in all probability descended from a common ancestor. furthermore, residues important in the s ... | 1985 | 2998002 |
| togaviridae. | the family togaviridae comprises four genera: alphavirus (with 26 species), rubivirus (one species), pestivirus (three species), and arterivirus (one species). the main characteristics of the member viruses are: (i) the virus particles are spherical, 50-70 nm in diameter, including an envelope with surface projections that incorporate two or three polypeptides, usually glycosylated; (ii) the nucleocapsid comprises a core protein and a single strand of positive-sense rna, molecular weight about 4 ... | 1985 | 2999027 |
| neutralization of yellow fever virus studied using monoclonal and polyclonal antibodies. | monoclonal and polyclonal antibodies with known specificity for either the 54k envelope glycoprotein or the 48k non-structural glycoprotein of yellow fever (yf) virus-infected cells were studied in plaque reduction neutralization tests. viruses employed in the tests comprised wild-type and vaccine strains of yf and a selection of other flaviviruses. of 17 monoclonal antibodies examined, six of the 54k-specific antibodies neutralized at least one yf preparation. both vaccine and wild-type yf viru ... | 1985 | 2999305 |
| two-dimensional gel electrophoresis of rnase t1 resistant oligonucleotides of flavivirus rna using ultrathin gels. | a convenient method employing a commercially available apparatus for two-dimensional gel electrophoresis of rnase t1 resistant oligonucleotides using ultrathin gels has been developed. the methodology overcomes problems commonly associated with the establishment of good, bubble-free, fusion of the first and second dimension gels. the use of ultrathin gels results in autoradiograms with well resolved oligonucleotide spots. | 1989 | 2536383 |
| carboxy-terminal analysis of nine proteins specified by the flavivirus kunjin: evidence that only the intracellular core protein is truncated. | nine proteins specified by kunjin virus were labelled with [3h]lysine and digested with carboxypeptidase b which specifically cleaves carboxy-terminal lys or arg. the theoretical amount of [3h]lysine was released from the non-structural (ns) proteins ns2a, ns2b, ns3 and ns4b, which have a common carboxy terminus lys-arg deduced from cleavage sites established in the viral polyprotein by previous n-terminal amino acid analyses. this is a flavivirus consensus site, always followed by gly, ala or s ... | 1989 | 2549188 |
| site of suppression of banzi viral replication by an antiviral factor released from aedes albopictus cells persistently infected with banzi virus. | the ability of the antiviral factor present in culture medium of aedes albopictus cells persistently infected with the flavivirus, banzi virus, to inhibit the replication of banzi virus was examined. the anti-banzi viral factor did not inhibit the uncoating of the virion. levels of viral rna were markedly reduced in mosquito cells treated with the antiviral factor. syntheses of negative-strand and of positive-strand viral rna species were inhibited to approximately the same extent. this inhibiti ... | 1985 | 3002069 |
| antibody enhanced viral growth in macrophages. | antiviral antibody can promote viral entry into macrophages by pathways involving cellular receptors for the fc portion of immunoglobulin or for complement components. whether virus taken up through these routes is restricted or results in productive infection depends upon a balance between a number of variables. these include the virus strain and dose, the macrophage source and state of activation, the concentration, class and viral specificity of the antibody, and environmental factors such as ... | 1985 | 3002973 |
| genetic aspects of macrophage involvement in natural resistance to virus infections. | macrophages are thought to constitute an important element in the body's natural defense against invasion and dissemination of viruses. possible antiviral mechanisms of macrophages are defined and referred to as intrinsic, i.e. the ability of macrophages to serve as a nonpermissive barrier between the virus and susceptible cells and extrinsic, i.e. the ability of macrophages to affect the virus or virus replication in surrounding cells. most studies on the role of macrophages in natural resistan ... | 1985 | 3002974 |
| stimulation of helper/delayed-type hypersensitivity t cells by flavivirus infection: determination by macrophage procoagulant assay. | west nile virus (wnv)-immune spleen cells produced an inducer of macrophage procoagulant activity (mpca) on restimulation with wnv in vitro. this response was specific for wnv and depended on the presence of thy 1+, l3t4+ and also ia+ cells but not lyt 2+ cells. it could be induced by culture with large amounts of non-infectious, u.v.-irradiated virus or with high doses of infectious virus. inoculation of mice with low titres of infectious, but not with u.v.-irradiated, virus primed for this in ... | 1986 | 3003235 |
| classification of barmah forest virus as an alphavirus using cytotoxic t cell assays. | barmah forest virus, an arbovirus, does not cross-react convincingly with alpha-, flavi- or bunyavirus immune sera. secondary cytotoxic t cells generated in vitro immune to a number of alphaviruses cross-lyse barmah forest virus-infected target cells. flavivirus (west nile and kunjin)- and bunyamwera virus-immune tc cells lyse homologous virus-infected target cells, but not alphavirus-infected targets. using cytotoxic t cell assays barmah forest virus can be classified as an alphavirus. | 1986 | 3003237 |
| experimental infection with murray valley encephalitis virus: galahs, sulphur-crested cockatoos, corellas, black ducks and wild mice. | orally infected culex annulirostris or intravenous injections were used to infect 10 galahs, 15 sulphur-crested cockatoos, 12 corellas, 4 black ducks and 10 wild mice with murray valley encephalitis (mve) virus. the birds produced moderate viraemias of titres of log 10(2.0)-10(6.0) suckling mouse intracerebral (smic) ld50/ml for durations of 1-9 d. however, the wild mice developed low grade viraemia for 1-4 d. recipient cx annulirostris feeding on viraemic birds sustained infection rates of 0-10 ... | 1985 | 3004402 |
| arbovirus infections of humans in new south wales. seroepidemiology of the flavivirus group of togaviruses. | a seroepidemiological study of 16 842 human sera, collected in 1981 and 1982 from all health regions of new south wales, was carried out using the haemagglutination-inhibition (hi) test and eight australasian flaviviruses: murray valley encephalitis (mve); kunjin (kun); alfuy (alf); stratford (str); kokobera (kok); edge hill (eh); sepik (sep); and saumarez reef (sre). a limited survey was also carried out with two recently discovered flaviviruses, gadgets gully and csiro 946. antibody prevalence ... | 1985 | 3007952 |
| partial n-terminal amino acid sequences of three nonstructural proteins of two flaviviruses. | partial n-terminal amino acid sequences for the three largest nonstructural proteins of two flaviviruses, yellow fever virus and st. louis encephalitis virus, have been obtained. the determined sequences of these proteins exhibit significant amino acid sequence homology, and allow the positioning of these three nonstructural proteins in the polyprotein sequence deduced from the nucleotide sequence of yellow fever virus (c. m. rice, e. m. lenches, s. r. eddy, s. j. shin, r. l. sheets, and j. h. s ... | 1986 | 3008425 |
| kunjin virus isolates of australia are genetically homogeneous. | the genomes of 22 isolates of kunjin virus (kun) from australia were characterized and compared using rnase t1 oligonucleotide fingerprinting. the results show that all isolates belonged to one topotype, the distribution of which covered the entire australian continent. this finding is similar to that of murray valley encephalitis virus, but in contrast to the results reported for some other flaviviruses such as saint louis encephalitis virus. | 1989 | 2552010 |
| [recent occurrence of human infection by rocio arbovirus in the valley of ribeira region]. | the presence of igm antibodies to rocio in sera of two children from rural area of ribeira valley, brazil, was detected by mac-elisa. this new arbovirus of the flaviviridae family was responsible for an extensive encephalitis epidemic that occurred in the region in 1975-1977. since 1980 no human disease caused by this virus has been diagnosed. an improvement on surveillance of rocio infections and on the researches for virus identification in suspected vectors and reservoirs is necessary. | 1989 | 2554477 |
| arbovirus infection in a murray valley community. | serum antibodies to ross river virus and murray valley encephalitis virus were measured during 1974-1975 in residents of echuca, an urban murray valley community. a representative group of volunteers was obtained by random selection of households. the prevalence of antibodies to both viruses increased progressively with age. prevalence was equal in both sexes for both viruses in all age groups, indicating that the risk of infection was mainly determined by geography rather than by personal activ ... | 1986 | 3010928 |
| analysis of structural properties which possibly are characteristic for the 3'-terminal sequence of the genome rna of flaviviruses. | recently we have shown that an open reading frame comprising 10290 nucleotides is present on the infectious, single-stranded genome rna of the west nile flavivirus. we have now isolated cloned cdna representing the 3'-terminal untranslated region of this molecule. the sequence of this region which comprises 571 nucleotides is given in this report. recently, the nucleotide sequence of the genome rna of the yellow fever flavivirus has been described. a comparative analysis of the 3'-terminal untra ... | 1986 | 3011975 |
| susceptibility of laboratory and domestic animals to experimental infection with potiskum virus. | the biological characteristics of potiskum virus, a hitherto undescribed virus isolated in nigeria from the liver of a giant rat (cricetomys gambianus), were studied by experimental infections of laboratory and domestic animals. the laboratory animal hosts used included mice, rats, rabbits and chicks. suckling and weaning mice succumbed to fatal infection when infected with potiskum virus by intracerebral or intraperitoneal routes. infected mice had high titres of virus and mild histopathologica ... | 1989 | 2558278 |