Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| expression, purification, and characterization of the rna 5'-triphosphatase activity of dengue virus type 2 nonstructural protein 3. | dengue virus type 2 (den2), a member of the flaviviridae family of positive-strand rna viruses, contains a single rna genome having a type i cap structure at the 5' end. the viral rna is translated to produce a single polyprotein precursor that is processed to yield three virion proteins and at least seven nonstructural proteins (ns) in the infected host. ns3 is a multifunctional protein having a serine protease catalytic triad within the n-terminal 180 amino acid residues which requires ns2b as ... | 2002 | 12167347 |
| isolation of dengue 2 virus from a patient with central nervous system involvement (transverse myelitis). | a dengue fever case is described in a 58-year-old male patient with febrile illness and thrombocytopenia complicated by neurological involvement characterized by transverse myelitis followed by weakness of both legs and flaccid paralysis. muscle strength was much diminished and bilateral areflexia was observed. dengue 2 (den-2) virus was isolated and the patient sero-converted by hemagglutination-inhibition and igm-elisa tests. the rt-pcr test was positive to den-2 in acute phase serum and cultu ... | 2002 | 12170337 |
| production of the baculovirus-expressed dengue virus glycoprotein ns1 can be improved dramatically with optimised regimes for fed-batch cultures and the addition of the insect moulting hormone, 20-hydroxyecdysone. | a perennial problem in recombinant protein expression is low yield of the product of interest. a strategy which has been shown to increase the production of baculovirus-expressed proteins is to utilise fed-batch cultures. one disadvantage of this approach is the time-consuming task of optimising the feeding strategy. previously, a statistical optimisation routine was applied to develop a feeding strategy that increased the yield of beta-galactosidase (beta-gal) by 2.4-fold (biotechnol. bioeng. 5 ... | 2002 | 12176145 |
| vertical transmission of dengue-2 virus through aedes albopictus mosquitoes. | 2001 | 12206042 | |
| novel dl-galactan hybrids from the red seaweed gymnogongrus torulosus are potent inhibitors of herpes simplex virus and dengue virus. | a novel series of dl-galactan hybrids extracted from the red seaweed gymnogongrus torulosus, was evaluated for its in vitro antiviral properties against herpes simplex virus type 2 (hsv-2) and dengue virus 2 (den-2). these compounds were very active against both viruses with inhibitory concentration 50% (ic50) values in the range 0.6-16 microg/ml for hsv-2 and 0.19-1.7 microg/ml for den-2, respectively, as determined in a virus plaque reduction assay in vero cells. the dl-galactans lacked of cyt ... | 2002 | 12238532 |
| recombinant dengue virus type 2 envelope/hepatitis b surface antigen hybrid protein expressed in pichia pastoris can function as a bivalent immunogen. | a truncated version of the dengue virus type 2 envelope protein (den2e) encoding the first 395 amino acid (aa) residues, and den2e fused in-frame with the full-length 226-aa hepatitis b surface antigen (den2e-hbsag) protein were expressed in the methylotrophic yeast, pichia pastoris. both the recombinant proteins showed evidence of the capacity to form high molecular weight aggregates. electron microscopic analysis of the purified proteins showed that while den2e displayed an amorphous morpholog ... | 2002 | 12270598 |
| in vitro determination of dengue virus type 2 ns2b-ns3 protease activity with fluorescent peptide substrates. | the ns2b-ns3(pro) polyprotein segment from the dengue virus serotype 2 strain 16681 was purified from overexpressing e. coli by metal chelate affinity chromatography and gel filtration. enzymatic activity of the refolded ns2b-ns3(pro) protease complex was determined in vitro with dansyl-labeled peptide substrates, based upon native dengue virus type 2 cleavage sites. the 12mer substrate peptides and the cleavage products could be separated by reversed-phase hplc, and were identified by uv and fl ... | 2002 | 12297031 |
| heparin inhibits dengue-2 virus infection of five human liver cell lines. | liver is suggested to be the major target of dengue virus infection and plays an important role in the immunopathogenesis of dengue hemorrhagic fever. previously, we reported that five human liver cell lines (huh-7, ha22t, hep3b, plc, and chang liver) with various degrees of differentiation and tumorigenicity showed different susceptibility for dengue virus infection. here, we demonstrate that heparin, an analogue of heparan sulfate (hs), can compete with hs on cell membrane for virus binding an ... | 2002 | 12323403 |
| high circulating levels of the dengue virus nonstructural protein ns1 early in dengue illness correlate with the development of dengue hemorrhagic fever. | infection with any 1 of 4 dengue viruses produces a spectrum of clinical illness ranging from a mild undifferentiated febrile illness to dengue fever (df) to dengue hemorrhagic fever (dhf), a potentially life-threatening disease. the morbidity and mortality of dhf can be reduced by early hospitalization and careful supportive care. to determine its usefulness as a predictor of dhf, plasma levels of the secreted dengue virus nonstructural protein ns1 (sns1) were measured daily in 32 children with ... | 2002 | 12355369 |
| genetic structure of aedes aegypti populations in chiang mai (thailand) and relation with dengue transmission. | we analysed the population genetic structure and differentiation regarding vector competence for a dengue virus of 15 aedes aegypti samples collected from chiang mai in northern thailand. based on polymorphism of 10 isoenzyme loci, genetic differentiation was confirmed among samples collected in different subdistricts (high fst values and p < 0.05). based on infection rate for a dengue 2 virus, susceptibilities were similar in mosquitoes collected in san nuea subdistrict and in choeng doi subdis ... | 2002 | 12358622 |
| variation in vector competence for dengue 2 virus among 24 collections of aedes aegypti from mexico and the united states. | aedes aegypti from 24 collections in mexico and the united states were challenged orally with dengue 2 virus jam1409 (den-2 jam1409). the vector competence (vc) of the populations ranged from 24% to 83%. mosquito populations from the yucatan exhibited greater vc than those from other areas of mexico. the presence or absence of a midgut infection barrier (mib) and a midgut escape barrier (meb) was determined for mosquitoes in each population. the percentage of mosquitoes exhibiting an mib ranged ... | 2002 | 12363070 |
| antibodies from dengue patient sera cross-react with endothelial cells and induce damage. | dengue virus infection causes a wide range of diseases from the mild febrile illness dengue fever to the life-threatening dengue hemorrhagic fever (dhf) and dengue shock syndrome (dss). vascular leakage and hemorrhagic syndrome are the clinical features associated with dengue infection, yet the mechanisms remain unclear. in this study, the cross-reactivity of dengue patient sera with endothelial cells was demonstrated. there were higher percentages of endothelial cells reactive with dengue hemor ... | 2003 | 12436482 |
| rna silencing of dengue virus type 2 replication in transformed c6/36 mosquito cells transcribing an inverted-repeat rna derived from the virus genome. | double-stranded rna (dsrna) initiates cellular posttranscriptional responses that are collectively called rna silencing in a number of different organisms, including plants, nematodes, and fruit flies. in plants, rna silencing has been associated with protection from virus infection. in this study, we demonstrate that dsrna-mediated interference also can act as a viral defense mechanism in mosquito cells. c6/36 (aedes albopictus) cells were stably transformed with a plasmid designed to transcrib ... | 2002 | 12438618 |
| detection of dengue virus replication in peripheral blood mononuclear cells from dengue virus type 2-infected patients by a reverse transcription-real-time pcr assay. | while dengue virus is thought to replicate in mononuclear phagocytic cells in vivo, attempts to detect it in peripheral blood mononuclear cells (pbmc) by virus isolation or antigen detection have had variable and generally low rates. in this study, we developed a reverse transcription (rt)-real-time pcr assay to quantify positive- and negative-sense rna of dengue virus type 2 within the cells. the assay includes an rt step using either sense or antisense primer followed by a real-time pcr step u ... | 2002 | 12454138 |
| complete nucleotide sequence analysis of a brazilian dengue virus type 2 strain. | in the last decade, dengue fever (df) in brazil has been recognized as an important public health problem, and an increasing number of dengue haemorrhagic fever (dhf) cases have been reported since the introduction of dengue virus type 2 (den-2) into the country in 1990. in order to analyze the complete genome sequence of a den-2 brazilian strain (br64022/98), we designed primers to amplify contiguous segments of approximately 500 base pairs across the entire sequence of the viral genome. twenty ... | 2002 | 12471426 |
| geographic genetic variation in populations of the dengue virus vector aedes aegypti. | isoenzyme variation was assessed in 79 mosquito samples of aedes aegypti, and susceptibility to a dengue 2 virus strain was evaluated in 83 samples. analysis of fst values, differentiation indexes, and geographic distances separating populations revealed that genetic differences between populations depended on the species' history of migration and colonization. three major clusters were identified: (1). the sylvan form, ae. ae. formosus, from west africa and some islands in the indian ocean; (2) ... | 2002 | 12486524 |
| [studies of the resistance of the recombinant alphavirus rnas containing dengue-2 prm gene to virus infection]. | the amplified prm gene of dengue-2 virus was cloned into the downstream sp6 promoter-psfv vector and the recombinant plasmid (psf.rm2) dna which contained sense- or antisense-prm gene, was selected. psf.rm2 dna and helper dna linearized by the enzyme spei digestion were both transcribed in vitro into recombinant rnas which contained the capping analog on the 5'-end and contaansfected into bhk cells by electroportation. the the transfected host cells were challenged with dengue-2 virus and the re ... | 2001 | 12549088 |
| [changes in element content in aedes albopictus infected by dengue virus type ii]. | to study the changes in the content of elements in aedes albopictus after dengue virus type ii (dv2) infection. | 2002 | 12567999 |
| [effect of dengue virus infection on the production of et-1 and pgi2 by human vascular endothelial cells]. | to study the effect of dengue virus infection on the production of endothelin 1(et-1) and prostacyclin 2(pgi2) by human umbilical cord vein endothelial cells (huvecs). | 1999 | 12569754 |
| anti-tnf antibody treatment reduces mortality in experimental dengue virus infection. | here we describe a lethal mouse model infected with dengue virus type 2 with several similarities to human den-2 infection. clinically animals demonstrated anemia, thrombocytopenia, pre-terminal paralysis and shock. the most impressive changes were seen with tumor necrosis factor (tnf)-alpha, which abruptly and steeply increased 24 h before the exitus (mean at day 6). serum levels of il-1beta, il-6, il-10, il-1 receptor antagonist and soluble tnf receptor i continuously increased during the time ... | 2003 | 12589955 |
| supernatants from dengue virus type-2 infected macrophages induce permeability changes in endothelial cell monolayers. | the ability of dengue virus-infected human monocyte-derived macrophages to induce permeability changes in primary human umbilical vein endothelial cells was investigated. supernatants from dengue virus type 2-infected monocyte-derived macrophages increased permeability in human umbilical vein endothelial cell monolayers without inducing endothelial cell infection. production of permeabilising activity from monocyte-derived macrophages occurred after the peak of progeny virus release. tnf-alpha, ... | 2003 | 12601760 |
| yellow fever virus/dengue-2 virus and yellow fever virus/dengue-4 virus chimeras: biological characterization, immunogenicity, and protection against dengue encephalitis in the mouse model. | two yellow fever virus (yfv)/dengue virus chimeras which encode the prm and e proteins of either dengue virus serotype 2 (dengue-2 virus) or dengue-4 virus within the genome of the yfv 17d strain (yf5.2iv infectious clone) were constructed and characterized for their properties in cell culture and as experimental vaccines in mice. the prm and e proteins appeared to be properly processed and glycosylated, and in plaque reduction neutralization tests and other assays of antigenic specificity, the ... | 2003 | 12610141 |
| enhancing biosynthesis and secretion of premembrane and envelope proteins by the chimeric plasmid of dengue virus type 2 and japanese encephalitis virus. | we have constructed a series of plasmids encoding premembrane (prm) and envelope (e) protein genes of dengue virus type 2 (den-2). these plasmids included an authentic den-2 prm-e construct (pcbd2-14-6), and two chimeric constructs, 90% den-2 e-10% japanese encephalitis (je) virus e (pcb9d2-1j-4-3) and 80% den-2 e-20% je e (pcb8d2-2j-2-9-1). monoclonal antibody (mab) reactivity indicated that all three plasmids expressed authentic den-2 virus e protein epitopes representative of flavivirus domai ... | 2003 | 12620809 |
| steady-state cleavage kinetics for dengue virus type 2 ns2b-ns3(pro) serine protease with synthetic peptides. | the n-terminal part of the ns3 protein from dengue virus contains a trypsin-like serine protease responsible for processing the nonstructural region of the viral polyprotein. enzymatic activity of the ns2b-ns3(pro) precursor incorporating a full-length ns2b cofactor of dengue virus type 2 was examined by using synthetic dodecamer peptide substrates encompassing native cleavage sequences of the ns2a/ns2b, ns2b/ns3, ns3/ns4a and ns4b/ns5 polyprotein junctions. cleavage of the dansylated substrates ... | 2003 | 12625822 |
| american genotype structures decrease dengue virus output from human monocytes and dendritic cells. | the dengue virus type 2 structures probably involved in human virulence were previously defined by sequencing the complete genome of both american and southeast (se) asian genotype templates in patient serum (k. c. leitmeyer et al., j. virol. 73:4738-4747, 1999). we have now evaluated the effects of introducing a mutation in the envelope glycoprotein (e) gene and/or replacement of 5'- and 3'-nontranslated regions on dengue virus replication in human primary cell cultures. a series of chimeric in ... | 2003 | 12634353 |
| diverse dengue type 2 virus populations contain recombinant and both parental viruses in a single mosquito host. | envelope (e) protein genes sampled from populations of dengue 2 (den-2) virus in individual aedes aegypti mosquitoes and in serum from dengue patients were copied to cdna, cloned, and sequenced. the nucleotide sequences of the e genes in more than 70% of the clones differed from the consensus sequence for the corresponding virus population at up to 11 sites, and 24 of the 94 clones contained at least one stop codon. virus populations recovered up to 2 years apart yielded clones with similar poly ... | 2003 | 12634407 |
| amplification of the sylvatic cycle of dengue virus type 2, senegal, 1999-2000: entomologic findings and epidemiologic considerations. | after 8 years of silence, dengue virus serotype 2 (denv-2) reemerged in southeastern senegal in 1999. sixty-four denv-2 strains were isolated in 1999 and 9 strains in 2000 from mosquitoes captured in the forest gallery and surrounding villages. isolates were obtained from previously described vectors, aedes furcifer, ae. taylori, ae. luteocephalus, and--for the first time in senegal--from ae. aegypti and ae. vittatus. a retrospective analysis of sylvatic denv-2 outbreaks in senegal during the la ... | 2003 | 12643833 |
| secreted expression of dengue virus type 2 full-length envelope glycoprotein in pichia pastoris. | the full-length envelope glycoprotein gene of dengue virus type 2 was cloned using an rt-pcr method from the infected c6/36 cells and inserted into ppiczab vector. the recombinant plasmid was integrated into pichia pastoris by electroporation and the expressed product was identified by sds-page and western blotting. high-level secreted expression was performed by determining the mut(+) phenotype and screening multi-copy integrants in the recombinant yeast cells. a recombinant protein with a mole ... | 2003 | 12668263 |
| production of anti-dengue ns1 monoclonal antibodies by dna immunization. | monoclonal antibodies against dengue ns1 protein were generated following immunization of mice with plasmid dna encoding the transmembrane form of ns1 from dengue serotype 2 virus. a mammalian expression vector, pdisplay, was engineered to direct cell surface expression of dengue ns1 and tested for transient expression in cos cells. two mice were immunized intramuscularly with six doses of 100 microg of plasmid at 2-week intervals; one mouse received a booster of live virus prior to the last pla ... | 2003 | 12668268 |
| [aedes aegypti, vector of the dengue virus: spatio-temporal structure of its genetic variation]. | aedes aegypti is the main vector of dengue viruses. methods for limiting the spread of dengue outbreaks are currently based on vector control. estimates of population genetic organization and gene flow with respect to vector capacity have provided great insights into dengue epidemiology. in vietnam, dengue hemorrhagic fever was detected in the 1950's and becomes today the major problem of public health. among factors influencing dengue epidemiology, ecological disturbances have a direct impact o ... | 2002 | 12669664 |
| dengue fever outbreaks in two villages of dharmapuri district in tamil nadu. | dengue fever is an important public health problem in india. in recent years this disease has extended to rural areas also due to rapid urbanization. in tamil nadu, fever outbreaks were reported in two villages of dharmapuri district during may and september 2001 with clinical symptoms suggestive of dengue fever. epidemiological, virological and entomological investigations were carried out in these two villages to ascertain the etiology of the outbreaks. | 2002 | 12674826 |
| differential susceptibility of aedes aegypti to infection by the american and southeast asian genotypes of dengue type 2 virus. | outbreaks of dengue hemorrhagic fever have coincided with the introduction of the southeast (se) asian genotype of dengue type 2 virus in the western hemisphere. this introduced genotype appears to be rapidly displacing the indigenous, american genotype of dengue 2 virus throughout the region. these field observations raise the possibility that the se asian genotype of dengue 2 is better adapted for vector transmission than its american counterpart. to evaluate this hypothesis, we compared the a ... | 2001 | 12680353 |
| chimeric dengue type 2/type 1 viruses induce immune responses in cynomolgus monkeys. | chimeric dengue type 2/type 1 (den2/1) viruses, which contain the structural genes of the dengue-1 (16007) parental virus and the nonstructural genes of the den2-pdk53 virus, have been constructed. these den2/1 viruses induce high levels of den1 virus-specific neutralizing antibodies in mice. in this study, the den2/1 viruses induced den1 virus-specific neutralizing antibodies without the development of viremia in cynomolgus monkeys. dengue virus-specific igm antibodies were detected in the sera ... | 2002 | 12693596 |
| molecular typing of dengue virus type 2 in brazil. | strain typing is a critical tool for molecular epidemiological analysis and can provide important information about the spread of dengue viruses. here, we performed a molecular characterization of den-2 viruses isolated in brazil during 1990-2000 from geographically and temporally distinct areas in order to investigate the genetic distribution of this serotype circulating in the country. restriction site-specific polymerase chain reaction (rss)-pcr presented the same pattern for all 52 brazilian ... | 2003 | 12751317 |
| a ligand-binding pocket in the dengue virus envelope glycoprotein. | dengue virus is an emerging global health threat. its major envelope glycoprotein, e, mediates viral attachment and entry by membrane fusion. a crystal structure of the soluble ectodomain of e from dengue virus type 2 reveals a hydrophobic pocket lined by residues that influence the ph threshold for fusion. the pocket, which accepts a hydrophobic ligand, opens and closes through a conformational shift in a beta-hairpin at the interface between two domains. these features point to a structural pa ... | 2003 | 12759475 |
| tick-borne encephalitis with hemorrhagic syndrome, novosibirsk region, russia, 1999. | eight fatal cases of tick-borne encephalitis with an unusual hemorrhagic syndrome were identified in 1999 in the novosibirsk region, russia. to study these strains, we sequenced cdna fragments of protein e gene from six archival formalin-fixed brain samples. phylogenetic analysis showed tick-borne encephalitis variants clustered with a far eastern subtype (homology 94.7%) but not with the siberian subtype (82%). | 2003 | 12781020 |
| dengue virus envelope glycoprotein structure: new insight into its interactions during viral entry. | 2003 | 12782795 | |
| serological & virological investigation of an outbreak of dengue fever in gwalior, india. | an outbreak of febrile illness occurred between september to november 2001 in gwalior, madhya pradesh affecting individuals mostly in the age group < 30 yr. a total of 312 febrile indoor patients suspected to have dengue infection were investigated. | 2002 | 12807151 |
| [isolation, identification and sequence analyses of dengue virus type 2 strain gd19/2001]. | to identify the virus isolated from jiangmen, guangdong province and to discuss the possible origin. | 2003 | 12820947 |
| dengue virus type 2 ns3 protease and ns2b-ns3 protease precursor induce apoptosis. | apoptosis was detected in vero cell cultures expressing transfected dengue virus type 2 (denv-2) genes. approximately 17.5 and 51.5 % of cells expressing ns3 serine protease and ns2b-ns3(185) serine protease precursor protein [ns2b-ns3(185)(pro)] genes, respectively, were apoptotic. the percentage of apoptotic cells was significantly higher in cell cultures expressing ns2b-ns3(185)(pro). ns2b-ns3(185)(pro) was detected as ns2b-ns3(185)(pro)-egfp fusion protein in cytoplasmic vesicular structures ... | 2003 | 12867651 |
| vaccination of rhesus macaques against dengue-2 virus with a plasmid dna vaccine encoding the viral pre-membrane and envelope genes. | a nucleic acid vaccine for dengue-2 virus was developed, consisting of a plasmid dna vector with the pre-membrane (prm) and envelope (e) genes expressed from a cytomegalovirus promoter. the dna was adsorbed onto gold microspheres for administration by a gene gun. expression was demonstrated by transfection of mouse cells in culture where the prm and e antigens were detected intracellularly, and the e antigen was detected in the culture supernatant fluid, similar to a natural infection. the vacci ... | 2003 | 12875299 |
| comparative immunological recognition of proteins from new guinea "c" dengue virus type 2 prototype and from a dengue virus type 2 strain isolated in the state of rio de janeiro, brazil. | the protein profiles of the new guinea "c" dengue virus type 2 (denv-2)prototype and those of a brazilian denv-2 isolated in the state of rio de janeiro in 1995 were compared. sds-page analysis showed that the virus from rio de janeiro expresses ns5 (93.0 kda), ns3 (66.8 kda) e (62.4 kda) and ns1 (41.2 kda) proteins differently from the new guinea "c" virus. the immunoblot revealed specificity and antigenicity for the ns3 protein from denv-2 rio de janeiro mainly in primary infections, convalesc ... | 2003 | 12886411 |
| a fragment of the envelope protein from dengue-1 virus, fused in two different sites of the meningococcal p64k protein carrier, induces a functional immune response in mice. | previously we have reported the capacity of the fusion protein pd3, composed of the p64k protein and the envelope (e) fragment from amino acids (aa) 286-426 of dengue-2 virus (den-2), to induce a functional immune response in mice against the homologous virus. in that case, the e fragment was inserted within the lipoyl-binding domain of the meningococcal p64k protein. in the present study, to test the functionality of the same e region from dengue-1 (den-1), a similar construct was made. further ... | 2004 | 12887334 |
| evaluation of protective efficacy and immune mechanisms of using a non-structural protein ns1 in dna vaccine against dengue 2 virus in mice. | to evaluate the potential of dna vaccine against dengue (den) infection, we characterize the protective efficacy and immune responses of mice intramuscularly injected with plasmid encoding den-2 non-structural protein 1 (ns1). intravenously challenged by lethal den-2, mice vaccinated with ns1-dna exhibited a delay onset of paralysis, a marked decrease of morbidity, and a significant enhancement of survival. in addition to a moderate increase of ns1-specific antibody titer from immunized mice mea ... | 2003 | 12922127 |
| blocking the dengue virus 2 infections on bhk-21 cells with purified recombinant dengue virus 2 e protein expressed in escherichia coli. | dengue viruses (dvs) are mosquito-borne infectious pathogens. they have become an expanding public health problem in the tropics and subtropics. the dengue envelope (e) protein is one of the viral structure proteins responsible mainly for the virus attachment and entry onto host cells. it is also the major immunogen for virus neutralization. in this study, we have constructed a recombinant plasmid expressing a truncated e protein of dv-2 virus pl046 strain. the c-terminal hydrophobic domain of t ... | 2003 | 12963043 |
| aedes aegypti in south vietnam: ecology, genetic structure, vectorial competence and resistance to insecticides. | in vietnam, dengue hemorrhagic fever has been detected since the 1950s. in southeast asia, urban centers expanded rapidly in an uncontrolled and unplanned way. the aedes aegypti populations and dengue viruses thrived in these new ecological and demographic settings. the result of these changes was a greatly extended geographic distribution, increased densities of ae. aegypti and the maintenance of the four dengue serotypes leading to a dramatic increase in dengue transmission. to assess the role ... | 2003 | 12971518 |
| identification of a dengue virus type 2 (den-2) serotype-specific b-cell epitope and detection of den-2-immunized animal serum samples using an epitope-based peptide antigen. | in this study, a serotype-specific monoclonal antibody (mab), d(2) 16-1 (ab4), against dengue virus type 2 (den-2) was generated. the specificity of ab4, which recognized den-2 non-structural protein 1, was determined by elisa, immunofluorescence and immunoblotting analyses. the serotype-specific b-cell epitope of ab4 was identified further from a random phage-displayed peptide library; selected phage clones reacted specifically with ab4 and did not react with other mabs. immunopositive phage cl ... | 2003 | 13679612 |
| substitution of the structural genes of dengue virus type 4 with those of type 2 results in chimeric vaccine candidates which are attenuated for mosquitoes, mice, and rhesus monkeys. | antigenic chimeric viruses in which the structural genes of dengue virus type 4 (den4) have been replaced with those derived from dengue virus type 2 (den2) have been created and evaluated as a first step in generating a live attenuated tetravalent dengue virus vaccine. specifically, the capsid, membrane precursor, and envelope (cme) or the membrane precursor and envelope (me) gene regions of den2 were substituted for the corresponding genes of wild-type rden4 or vaccine candidate rden4delta30 w ... | 2003 | 14505913 |
| mutations which enhance the replication of dengue virus type 4 and an antigenic chimeric dengue virus type 2/4 vaccine candidate in vero cells. | mutations which increase the replication of dengue viruses in cell culture would greatly facilitate the manufacture of both a live attenuated or inactivated dengue virus vaccine. we have identified eight missense mutations in dengue virus type 4 (den4) that increase the plaque size and kinetics of replication of recombinant den4 virus in vero cells. den4 viruses bearing these vero cell adaptation mutations were also evaluated for the level of replication in the brains of mice. two of these eight ... | 2003 | 14505914 |
| e/ns1 modifications of dengue 2 virus after serial passages in mammalian and/or mosquito cells. | dengue viruses are routinely maintained in nature by transmission cycles involving the passage of virus between humans and aedes mosquitoes. the number of dengue virus lineages has been increasing over time. the aim of this study was to identify the genetic diversity of dengue 2 virus serially transferred in mammalian and/or mosquito cells. | 2003 | 14555849 |
| dengue virus type 2 infects human endothelial cells through binding of the viral envelope glycoprotein to cell surface polypeptides. | the endothelial cell line ecv304, derived from human umbilical cord and identified to be susceptible to dengue virus type 2 (den-2) infection, was used to study the molecular mechanism of den-2 binding to endothelial cells. den-2 was found by virus overlay protein-binding assays (vopbas) to bind to three ecv304 cell membrane proteins with molecular masses of 29, 34 and 43 kda. only a single protein of 29 kda was observed when vopbas were carried out using preparations of trypsin-treated ecv304 c ... | 2003 | 14573814 |
| virucidal activity of essential oils from aromatic plants of san luis, argentina. | essential oils obtained from eight aromatic plants of san luis province, argentina, were screened for virucidal activity against herpes simplex virus type 1 (hsv-1), junin virus (junv) and dengue virus type 2 (den-2). the most potent inhibition was observed with the essential oil of lippia junelliana and lippia turbinata against junv with virucidal concentration 50% (vc(50)) values in the range 14-20 ppm, whereas aloysia gratissima, heterotheca latifolia and tessaria absinthioides inhibited junv ... | 2003 | 14595590 |
| replication-defective adenoviral vaccine vector for the induction of immune responses to dengue virus type 2. | a recombinant replication-defective adenovirus vector that can overexpress the ectodomain of the envelope protein of dengue virus type 2 (ngc strain) has been constructed. this virus was immunogenic in mice and elicited dengue virus type 2 specific b- and t-cell responses. sera from immunized mice contained neutralizing antibodies that could specifically recognize dengue virus type 2 and neutralize its infectivity in vitro, indicating that this approach has the potential to confer protective imm ... | 2003 | 14610213 |
| a dengue-2 envelope fragment inserted within the structure of the p64k meningococcal protein carrier enables a functional immune response against the virus in mice. | a gene fragment encoding for the amino acids (aa) 286-426 from the dengue envelope (e) protein was expressed in escherichia coli as two forms of fusion proteins. in one case, the e fragment was fused to the first 45 aa of the p64k protein from neisseria meningitidis (pd2) while, in the other, it was inserted within the lipoil-binding domain of the aforementioned bacterial protein (pd3). pd2 was obtained as insoluble form within the cytoplasm of the bacteria while pd3 was distributed equally as s ... | 2004 | 14656459 |
| an external loop region of domain iii of dengue virus type 2 envelope protein is involved in serotype-specific binding to mosquito but not mammalian cells. | dengue virus (dv) is a flavivirus and infects mammalian cells through mosquito vectors. this study investigates the roles of domain iii of dv type 2 envelope protein (eiii) in dv binding to the host cell. recombinant eiii interferes with dv infection to bhk21 and c6/36 cells by blocking dengue virion adsorption to these cells. inhibition of eiii on bhk21 cells was broad with no serotype specificity; however, inhibition of eiii on c6/36 cells was relatively serotype specific. soluble heparin comp ... | 2004 | 14671119 |
| tetracycline-inducible packaging cell line for production of flavivirus replicon particles. | we have previously developed replicon vectors derived from the australian flavivirus kunjin that have a unique noncytopathic nature and have been shown to direct prolonged high-level expression of encoded heterologous genes in vitro and in vivo and to induce strong and long-lasting immune responses to encoded immunogens in mice. to facilitate further applications of these vectors in the form of virus-like particles (vlps), we have now generated a stable bhk packaging cell line, tetkuncprme, carr ... | 2004 | 14671135 |
| high-level expression and one-step purification of recombinant dengue virus type 2 envelope domain iii protein in escherichia coli. | dengue virus infection poses a serious global public health threat for which there is currently no therapy or a licensed vaccine. the domain iii of the dengue virus encoded envelope protein, which carries multiple conformation-dependent neutralizing epitopes, is critical for virus infectivity. we have expressed and purified recombinant domain iii of dengue virus type-2 envelope, without the aid of a carrier protein in escherichia coli. a 6x his tag was inserted at the n terminus to facilitate it ... | 2004 | 14680965 |
| translation efficiency determines differences in cellular infection among dengue virus type 2 strains. | we have investigated the molecular basis for differences in the ability of natural variants of dengue virus type 2 (den2) to replicate in primary human cells. the rates of virus binding, virus entry, input strand translation, and rna stability of low-passage thai and nicaraguan and prototype den2 strains were compared. all strains exhibited equivalent binding, entry, and uncoating, and displayed comparable stability of positive strand viral rna over time in primary cells. however, the low-passag ... | 2003 | 14698666 |
| real-time reverse transcription loop-mediated isothermal amplification for rapid detection of west nile virus. | a one-step, single tube, real-time accelerated reverse transcription loop-mediated isothermal amplification (rt-lamp) assay was developed for detecting the envelope gene of west nile (wn) virus. the rt-lamp assay is a novel method of gene amplification that amplifies nucleic acid with high specificity, efficiency, and rapidity under isothermal conditions with a set of six specially designed primers that recognize eight distinct sequences of the target. the whole procedure is very simple and rapi ... | 2004 | 14715762 |
| structure of the dengue virus envelope protein after membrane fusion. | dengue virus enters a host cell when the viral envelope glycoprotein, e, binds to a receptor and responds by conformational rearrangement to the reduced ph of an endosome. the conformational change induces fusion of viral and host-cell membranes. a three-dimensional structure of the soluble e ectodomain (se) in its trimeric, postfusion state reveals striking differences from the dimeric, prefusion form. the elongated trimer bears three 'fusion loops' at one end, to insert into the host-cell memb ... | 2004 | 14737159 |
| genetic vaccination of mice with plasmids encoding the ns1 non-structural protein from tick-borne encephalitis virus and dengue 2 virus. | although there is a safe, inexpensive and efficacious vaccine against yellow fever, vaccination against other flavivirus diseases is less successful. there is no licensed vaccine against dengue fever and current vaccines against tick-borne encephalitis (tbe) and japanese encephalitis are expensive and require several injections. furthermore novel vaccines containing only virus envelope proteins may raise fears over antibody mediated enhancement (ade) of disease. here we report the successful use ... | 2004 | 14739654 |
| risk factors for infection during a severe dengue outbreak in el salvador in 2000. | in 2000, el salvador experienced a large dengue-2 virus epidemic with many severe cases. a seroepidemiologic survey was conducted in 106 randomly selected households (501 residents) in an affected community (las pampitas). the frequency of recent infection, documented by the presence of igm antibodies or high-titer igg antibodies to dengue virus, was estimated to be 9.8% (95% confidence interval [ci] = 5.8-13.7), of which at least 44% were secondary infections. the number of containers positive ... | 2003 | 14740880 |
| enhanced vector competence of aedes aegypti (diptera: culicidae) from the torres strait compared with mainland australia for dengue 2 and 4 viruses. | australian aedes aegypti (l.) mosquitoes colonized from the torres strait and three mainland localities (charters towers, townsville, and cairns) were fed on blood suspensions containing dengue virus type 2 (den-2) or dengue virus type 4 (den-4). variation was found in oral susceptibility to den-2 (59 -99% infection) and den-4 (28-79% infection) among ae. aegypti assayed for virus at 8, 12, 16, or 20 d after ingestion of infected blood. torres strait ae. aegypti were the most susceptible to den- ... | 2003 | 14765675 |
| alterations of pr-m cleavage and virus export in pr-m junction chimeric dengue viruses. | during the export of flavivirus particles through the secretory pathway, a viral envelope glycoprotein, prm, is cleaved by the proprotein convertase furin; this cleavage is required for the subsequent rearrangement of receptor-binding e glycoprotein and for virus infectivity. similar to many furin substrates, prm in vector-borne flaviviruses contains basic residues at positions p1, p2, and p4 proximal to the cleavage site; in addition, a number of charged residues are found at position p3 and be ... | 2004 | 14963133 |
| contribution of disulfide bridging to epitope expression of the dengue type 2 virus envelope glycoprotein. | the individual contributions of each of the six conserved disulfide (ss) bonds in the dengue 2 virus envelope (e) glycoprotein (strain 16681) to epitope expression was determined by measuring the reactivities of a panel of well-defined monoclonal antibodies (mabs) with llc-mk(2) cells that had been transiently transformed with plasmid vectors expressing e proteins that were mutant in their ss bonds. three domain i (di) epitopes (c1, c3, and c4) were affected by elimination of any ss bond and wer ... | 2004 | 14963174 |
| determination of the disulfide bond arrangement of dengue virus ns1 protein. | the 12 half-cystines of ns1 proteins are absolutely conserved among flaviviruses, suggesting their importance to the structure and function of these proteins. in the present study, peptides from recombinant dengue-2 virus ns1 were produced by tryptic digestion in 100% h(2)(16)o, peptic digestion in 50% h(2)(18)o, thermolytic digestion in 50% h(2)(18)o, or combinations of these digestion conditions. peptides were separated by size exclusion and/or reverse phase high performance liquid chromatogra ... | 2004 | 14981082 |
| differential display rt-pcr analysis of ecv304 endothelial-like cells infected with dengue virus type 2 reveals messenger rna expression profiles of multiple human genes involved in known and novel roles. | differential display (dd)-rt-pcr was employed to analyze mrnas from ecv304 human endothelial-like cells undergoing apoptosis following infection with the virulent new guinea c strain of dengue virus type 2 in order to elucidate the cellular gene responses to dengue viral infection at the transcriptional level. we isolated, sequenced, and identified 203 differentially expressed and overlapping cdna fragments, all of which were of human origin except 1 that was of viral origin. out of these, 78 we ... | 2004 | 14981762 |
| relationship of preexisting dengue virus (dv) neutralizing antibody levels to viremia and severity of disease in a prospective cohort study of dv infection in thailand. | infection with any 1 of the 4 dengue viruses (dvs) can produce several illnesses, ranging from a mild febrile illness to classic dengue fever (df) to dengue hemorrhagic fever (dhf), a potentially life-threatening disease. most dhf cases occur after sequential heterotypic dv infections. the role of preexisting humoral immunity in modifying severity of dengue disease is not well understood. | 2004 | 14999601 |
| cysteine mediated multimerization of a recombinant dengue e fragment fused to the p64k protein following immobilized metal ion affinity chromatography. | a fragment of the envelope protein of dengue 2 virus encoding the amino acid (aa) 286-426 was fused to the p64k protein from neisseria meningitidis. the hybrid gene (pd5) was expressed in escherichia coli. the influence of using immobilized metal ion affinity chromatography (imac) in the purification process of pd5 was examined. after the elution, pd5 protein formed aggregates of high molecular weight depending on disulfide-bonds. the study of different conditions affecting the redox potential i ... | 2004 | 15003248 |
| rna interference, arthropod-borne viruses, and mosquitoes. | rna interference (rnai) probably functions as an antiviral mechanism in most eukaryotic organisms. variations in the activity of this antiviral pathway in mosquitoes could explain, in part, why some mosquitoes are competent vectors of medically important, arthropod-borne viruses (arboviruses) and others are not. there are three lines of evidence that show the rnai pathway exists in aedes species that transmit arboviruses. the first is that recombinant sindbis viruses expressing a rna fragment fr ... | 2004 | 15068882 |
| the non-structural 3 (ns3) protein of dengue virus type 2 interacts with human nuclear receptor binding protein and is associated with alterations in membrane structure. | flaviviral infections produce a distinct array of virus-induced intracellular membrane alterations that are associated with the flaviviral replication machinery. currently, it is still unknown which flaviviral protein(s) is/are responsible for this induction. using yeast two-hybrid and co-immunoprecipitation analyses, we demonstrated that the ns3 protein of dengue virus type 2 interacted specifically with nuclear receptor binding protein (nrbp), a host cellular protein that influences traffickin ... | 2004 | 15084397 |
| cytokine production in brain of mice experimentally infected with dengue virus. | dengue virus encephalopathy was experimentally induced in newborn mice by i.p. inoculation of dengue 2 virus. at 6 and 9 days post-infection, motor incoordination and posterior limb paralysis were observed with focal necrosis, apoptotic cells, perivascular inflammatory cuffing and astrocytosis, mainly in the cortex and hippocampus. expression of dengue virus genome and mrna encoding for tnf-alpha, il-1alpha, il-2, il-6, il-1beta, il-12 p40, ifnalpha, and ifnbeta; in addition host survival and in ... | 2004 | 15106828 |
| variation over space and time of aedes aegypti in phnom penh (cambodia): genetic structure and oral susceptibility to a dengue virus. | we studied spatial and temporal variation in 20-23 aedes aegypti samples collected in phnom penh and its suburbs to estimate the population genetic structure using allozymes and the susceptibility to a dengue-2 virus. based on seven allozyme systems, we detected low levels of genetic exchanges (i.e. high, significant f(st) values) between populations collected in the city centre, and different patterns of genetic structure for samples collected in the suburbs, depending on the type of environmen ... | 2003 | 15134196 |
| wild terrestrial rainforest mammals as potential reservoirs for flaviviruses (yellow fever, dengue 2 and st louis encephalitis viruses) in french guiana. | a serological survey for yellow fever virus (yfv), dengue 2 virus (denv-2), and st louis encephalitis virus (slev) was undertaken using a seroneutralization technique in 27 wild forest mammal species (574 individuals) in french guiana. evidence of yellow fever infection was observed in 10 species, with high prevalence recorded in howler monkey (18%) and agouti (20%). antibodies against denv-2 and slev were found sporadically in various species. this potential host diversity and the range of pote ... | 2004 | 15138077 |
| identification of a 48kda tubulin or tubulin-like c6/36 mosquito cells protein that binds dengue virus 2 using mass spectrometry. | binding of dengue virus 2 (denv-2) to c6/36 mosquito cells protein was investigated. a 48 kda denv-2-binding c6/36 cells protein (d2bp) was detected in a virus overlay protein-binding assay. the binding occurred only to the c6/36 cells cytosolic protein fraction and it was inhibited by free d2bp. d2bp was shown to bind to denv-2 e in the far-western-binding studies and using mass spectrometry (ms) and ms/ms, peptide masses of the d2bp that matched to beta-tubulin and alpha-tubulin chains were id ... | 2004 | 15207695 |
| enhanced esterase activity in salivary gland and midgut of aedes aegypti mosquito infected with dengue-2 virus. | mosquitoes were infected by intrathoracic inoculation. about 95% head squashes were positive for dengue virus antigen on the 15th post infection day (pid). esterase activity was determined in the homogenates prepared from the salivary glands and midguts on different pids of dengue virus inoculated and control mosquitoes showed that it was consistently higher in the virus-infected batches. | 2003 | 15267144 |
| identification of the homotypic interaction domain of the core protein of dengue virus type 2. | dengue virus causes dengue haemorrhagic fever or dengue shock syndrome with a high mortality rate. the genome of dengue virus is a positive-sense, single-stranded rna encoding three structural and seven non-structural proteins. the core protein is one of the three structural proteins and is the building block of the nucleocapsid of dengue virus. the core protein of dengue virus type 2 (den2) is composed of 100 aa with four alpha-helix domains. an internal hydrophobic domain located at aa 44-60 w ... | 2004 | 15269372 |
| development of cell lines stably expressing staphylococcal nuclease fused to dengue 2 virus capsid protein for ctvi. | to explore the potential application of capsid-targeted viral inactivation (ctvi) strategy in prophylactic model against dengue virus (dv) infection, here we fused a ca(2+)-dependent nuclease, staphylococcal nuclease (sn), to the capsid protein of dengue 2 virus (d2c) at the carboxyl terminal, and constructed the desired expression plasmid pc/d2c-sn and control plasmids pc/d2c-sn* and pc/d2c. a mammalian cell line bhk-21 was transfected by electroporation with those plasmids and thereafter selec ... | 2004 | 15295652 |
| fusion pcr generated japanese encephalitis virus/dengue 4 virus chimera exhibits lack of neuroinvasiveness, attenuated neurovirulence, and a dual-flavi immune response in mice. | the first flavivirus chimera encoding dengue 4 virus (d4) prm and e structural proteins in a japanese encephalitis virus (jev) backbone was successfully generated using the long-pcr based cdna-fragment stitching (lpcrcfs) technique, demonstrating the technique's applicability for rapid preparation of flavivirus chimeras. the jev/d4 chimera multiplied at levels equal to jev and d4 in the mosquito cell line c6/36, while in a mouse neuronal cell line (n2a) jev replicated efficiently, but jev/d4 and ... | 2004 | 15302944 |
| analysis of recombinant dengue virus polypeptides for dengue diagnosis and evaluation of the humoral immune response. | dengue is a serious cause of morbidity and mortality in tropical areas worldwide. we cloned and expressed recombinant polypeptides spanning the entire genome of a brazilian dengue virus type 2 (denv-2) strain in contiguous segments to generate antigens for dengue diagnosis and evaluation of the human humoral immune response. when analyzed by western blot and an enzyme-linked immunosorbent assay (elisa) using human sera, the most reactive polypeptide (pd2-3(e)) was located in the n-terminal porti ... | 2004 | 15306702 |
| conformational changes of the flavivirus e glycoprotein. | dengue virus, a member of the flaviviridae family, has a surface composed of 180 copies each of the envelope (e) glycoprotein and the membrane (m) protein. the crystal structure of an n-terminal fragment of e has been determined and compared with a previously described structure. the primary difference between these structures is a 10 degrees rotation about a hinge relating the fusion domain dii to domains di and diii. these two rigid body components were used for independent fitting of e into t ... | 2004 | 15341726 |
| a 7-deaza-adenosine analog is a potent and selective inhibitor of hepatitis c virus replication with excellent pharmacokinetic properties. | improved treatments for chronic hepatitis c virus (hcv) infection are needed due to the suboptimal response rates and deleterious side effects associated with current treatment options. the triphosphates of 2'-c-methyl-adenosine and 2'-c-methyl-guanosine were previously shown to be potent inhibitors of the hcv rna-dependent rna polymerase (rdrp) that is responsible for the replication of viral rna in cells. here we demonstrate that the inclusion of a 7-deaza modification in a series of purine nu ... | 2004 | 15388457 |
| vaccine candidates derived from a novel infectious cdna clone of an american genotype dengue virus type 2. | a dengue virus type 2 (den-2 tonga/74) isolated from a 1974 epidemic was characterized by mild illness and belongs to the american genotype of den-2 viruses. to prepare a vaccine candidate, a previously described 30 nucleotide deletion (delta30) in the 3' untranslated region of den-4 has been engineered into the den-2 isolate. | 2004 | 15461822 |
| the role of hemagglutinins in the midgut extracts of two lines of aedes aegypti in their susceptibility to dengue-2 virus. | hemagglutinin activity (ha) was studied in the midgut extracts from highly (h) and lowly susceptible strains of aedes aegypti mosquitoes to dengue-2 virus (den-2). ha in the midgut extracts from these two isofemale strains of mosquitoes was high in as compared to (h) mosquitoes. ha was found to be higher with chicken red blood cells (rbcs) than with rabbit and human rbcs of o group. larval midgut extracts showed higher activity than those from adult female mosquitoes. exposure of midgut extracts ... | 2004 | 15462286 |
| introduction of the american/asian genotype of dengue 2 virus into the yucatan state of mexico. | a dengue (den) outbreak occurred in the yucatan state of mexico in 2002. three isolates were obtained from patients presenting with den-like symptoms, and examined by partial nucleotide sequencing and phylogenetic analysis. the isolates were identified as den-2 viruses of the american-asian genotype; this is the first report of this genotype in the yucatan state. the den-2 viruses of the american-asian genotype have been associated with more severe disease outcomes. thus, its introduction into t ... | 2004 | 15516647 |
| epitope determinants of a chimpanzee fab antibody that efficiently cross-neutralizes dengue type 1 and type 2 viruses map to inside and in close proximity to fusion loop of the dengue type 2 virus envelope glycoprotein. | the epitope determinants of chimpanzee fab antibody 1a5, which have been shown to be broadly reactive to flaviviruses and efficient for cross-neutralization of dengue virus type 1 and type 2 (denv-1 and denv-2), were studied by analysis of denv-2 antigenic variants. sequence analysis showed that one antigenic variant contained a gly-to-val substitution at position 106 within the flavivirus-conserved fusion peptide loop of the envelope protein (e), and another variant contained a his-to-gln subst ... | 2004 | 15542644 |
| histopathological aspects of dengue-2 virus infected mice tissues and complementary virus isolation. | the difficulty in studying dengue virus (denv) infection in humans and in developing a virus vaccine is the absence of a suitable animal model which develops the full spectra of the dengue haemorrhagic fever (dhf) and dengue shock syndrome (dss). despite the fact that viruses have been found in various animal tissues, we isolated denv from tissues of adult balb/c mice, inoculated with denv serotype 2 (denv-2) obtained from human serum. viruses were ultrastructurally identified and immunolocalize ... | 2004 | 15554498 |
| histidine 39 in the dengue virus type 2 m protein has an important role in virus assembly. | the mature flavivirus particle comprises a nucleocapsid core surrounded by a lipid bilayer containing the membrane (m) (derived from the precursor prm) and envelope (e) proteins. the formation of intracellular prm/e heterodimers occurs rapidly after translation and is believed to be important for the assembly and secretion of immature virus particles. in this study, the role of the his residue at position 39 in the m protein (m39) of dengue virus type 2 (denv-2) in the virus life cycle was inves ... | 2004 | 15557235 |
| identification of residues in the dengue virus type 2 ns2b cofactor that are critical for ns3 protease activation. | proteolytic processing of the dengue virus polyprotein is mediated by host cell proteases and the virus-encoded ns2b-ns3 two-component protease. the ns3 protease represents an attractive target for the development of antiviral inhibitors. the three-dimensional structure of the ns3 protease domain has been determined, but the structural determinants necessary for activation of the enzyme by the ns2b cofactor have been characterized only to a limited extent. to test a possible functional role of t ... | 2004 | 15564480 |
| dengue virus type 2 in cuba, 1997: conservation of e gene sequence in isolates obtained at different times during the epidemic. | it was recently reported that disease severity increased during the 1997 cuban dengue 2 virus epidemic and it was suggested that this might be explained by the appearance of neutralization resistant escape mutants. we investigated these observations and ideas by sequencing 20 dengue 2 virus isolates obtained during the early (low case fatality rate) and the late (high case fatality rate) phases of the outbreak. our results showed total conservation of the e gene sequence for these isolates sugge ... | 2004 | 15578237 |
| therapeutic effects of dengue 2 virus capsid protein and staphylococcal nuclease fusion protein on dengue-infected cell cultures. | dengue infection poses a serious public health problem in most tropical and subtropical areas. no effective antiviral drugs or vaccines are currently available against dengue infection. to explore the feasibility of using capsid-targeted viral inactivation (ctvi) as an antiviral strategy against dengue infection, we constructed a plasmid expressing a fusion protein consisting of staphylococcal nuclease (sn) fused to dengue 2 virus capsid protein (d2c), and investigated its effects on the product ... | 2004 | 15592886 |
| deglycosylation of the ns1 protein of dengue 2 virus, strain 16681: construction and characterization of mutant viruses. | the dengue 2 virus (denv-2) ns1 glycoprotein contains two potential sites for n-linked glycosylation at asn-130 and asn-207. ns1 produced in infected cells is glycosylated at both of these sites. we used site-directed mutagenesis of a denv-2, strain 16681, full length infectious clone to create mutant viruses lacking the asn-130, asn-207 or both of these ns1 glycosylation sites in order to investigate the effects of deglycosylation. ablation of both ns1 glycosylation sites resulted in unstable v ... | 2004 | 15592895 |
| quantitative trait loci affecting dengue midgut infection barriers in an advanced intercross line of aedes aegypti. | quantitative trait loci (qtl) affecting the ability of the aedes aegypti midgut to become infected with dengue 2 virus (den2) were mapped in the f5 generation of an advanced intercross line (ail). a strain of ae. aegypti previously selected for den2 susceptibility was crossed to a new strain selected for refractoriness to midgut infection. in p1 and f1 parents and 147 f5 offspring, genotypes at forty-four cdna loci were analysed. a new sex linked qtl and a second qtl on chromosome ii with genoty ... | 2004 | 15606812 |
| [cloning of the ns1 gene of dengue-2 virus and determination of its partial nucleotide sequence]. | in this study, rt-pcr product of the ns1 gene of dengue-2 virus isolated in china was inserted into the dna of t-vector plasmid. dnas of the positive clones, which were identified by using the blue/white spot and pcr, were digested with enzymes, indicating that the inserted fragments were the same sizes as those of the amplified ns1 genes. the result of the nucleotide sequence determined by dideoxy chain-termination method indicated that 5'-terminal nucleotide sequence of the amplified ns1 fragm ... | 1997 | 15619908 |
| genetic characterization of yokose virus, a flavivirus isolated from the bat in japan. | yokose virus (strain oita-36) was isolated from the bat in japan in 1971. in the present study, we determined complete nucleotide sequences of yokose virus using rt-pcr and race techniques. yokose virus genome consists of 10,857 nucleotides in length (accession no. ab114858), containing a single open reading frame (3425 amino acids) encoding 11 viral proteins. we deduced the boundaries of each protein in the polyprotein sequence according to the protein cleavage sites of other flaviviruses. the ... | 2005 | 15661139 |
| antibody responses to asian and american genotypes of dengue 2 virus in immunized mice. | the possibility of a correlation between dengue virus genotype groups and disease severity is currently under discussion. the objective of this investigation was to identify any immunogenic difference between the american and asian dengue 2 virus genotypes through the study of antibody development (virus-binding immunoglobulin g and neutralizing antibodies) in mice. differences in the neutralization pattern between the strains studied were observed, suggesting the presence of slight antigenic va ... | 2005 | 15699435 |
| epidemiology of dengue and dengue hemorrhagic fever in a cohort of adults living in bandung, west java, indonesia. | a prospective study of dengue fever (df) and dengue hemorrhagic fever (dhf) was conducted in a cohort of adult volunteers from two textile factories located in west java, indonesia. volunteers in the cohort were bled every three months and were actively followed for the occurrence of dengue (den) disease. the first two years of the study showed an incidence of symptomatic den disease of 18 cases per 1,000 person-years and an estimated asymptomatic/ mild infection rate of 56 cases per 1,000 perso ... | 2005 | 15728868 |
| dengue virus detection by using reverse transcription-polymerase chain reaction in saliva and progeny of experimentally infected aedes albopictus from brazil. | oral susceptibility and vertical transmission of dengue virus type 2 (denv-2) in an aedes albopictus sample from rio de janeiro was estimated. the infection (36.7%) and transmission (83.3%) rates for ae. albopictus were higher than those of an ae. aegypti colony used as control, 32.8 and 60%, respectively. fourth instar larvae and females descendants of 48.5 and 39.1% of experimentally infected ae. albopictus showed to harbor the virus. the oral susceptibility and the high capacity to assure ver ... | 2004 | 15761595 |
| circulating human antibodies against dengue ns1 protein: potential of recombinant d2v-ns1 proteins in diagnostic tests. | the dengue virus (dv) causes one of the most important arthropod-borne human viral diseases throughout the tropical and subtropical countries. however, the morbidity and mortality of dv infections could be reduced with an early hospitalization care and a rapid risk identification of developing the dengue haemorrhagic fever (dhf). the nonstructural glycoprotein 1 (ns1) has been pointed as a reagent for immune-assay diagnostic test optimization. to evaluate this potential, recombinant dv2-ns1 prot ... | 2005 | 15780810 |
| quantitative trait loci that control dengue-2 virus dissemination in the mosquito aedes aegypti. | the mosquito aedes aegypti is the most important vector of yellow fever and dengue fever flaviviruses. ae. aegypti eradication campaigns have not been sustainable and there are no effective vaccines for dengue viruses. alternative control strategies may depend upon identification of mosquito genes that condition flavivirus susceptibility and may ultimately provide clues for interrupting transmission. quantitative trait loci affecting the ability of ae. aegypti to develop a dengue-2 infection in ... | 2005 | 15781707 |