| a simple technique for demonstrating transmission of dengue virus by mosquitoes without the use of vertebrate hosts. | aedes albopictus mosquitoes infected with dengue type 2 virus transmitted virus to measured small amounts of fluid which could be titrated readily for virus content. it was found that the percentage of mosquitoes transmitting was related to the extent of salivary gland infection. it was not uncommon for mosquitoes to transmit as much as 10(4) mosquito infectious doses50 of virus and transmission of significant amounts of virus was observed even though an insect only probed the test suspension wi ... | 1976 | 3980 |
| incidence of arbovirus antibodies in bovine, ovine and human sera collected in eastern sicily. | the incidence of antibodies against 9 arboviruses in ovine, bovine and human sera collected in eastern sicily was studied. a high incidence of antibodies was found especially against bhanja virus in all sera and against sandfly fever sicilian in ovine sera only. the incidence was higher than that reported in 1971 for the western part of sicily. these findings suggest an increase in the circulation of arboviruses in this area; the causes are briefly discussed. | 1976 | 7946 |
| hemorrhagic dengue fever. | | 1976 | 12637 |
| effects of tilorone hydrochloride on experimental flavivirus infections in mice. | the effect of tilorone hydrochloride on experimental infections of mice with west nile, langat and dengue type 2 viruses were studied. the drug significantly reduced the mortality after intraperitoneal inoculation of west nile virus, but failed to affect intracerebral infection with langat or dengue viruses. tilorone partially reversed cyclophosphan-enhanced mortality after extraneural inoculation of west nile and langat viruses. the possible modes of action of tilorone, interferon-inducing abil ... | 1977 | 17279 |
| an entomological survey on the mosquitoes of wuvulu island, papua-new guinea. | an entomological survey in wuvulu island, papua new guinea, in august 1975 and 1976 shows the presence of six mosquito species: aedes (s.) hebrideus, ae. (f.) notoscriptus, ae. (v.) lineatus, ? ae. (l.) dasyorrhus, culex pipiens fatigans and armigeres breinli. the medical significance of these mosquitoes is discussed, with special reference to the problem of dengue virus transmission. | 1977 | 18800 |
| dengue viral antigens in host cell membranes. | membranes from type 2 dengue virus (den-2) infected bhk cells, when used as immunogen, elicit antibodies detectable by complement fixation, hemagglutination inhibition and plaque reduction neutralization tests with suckling-mouse-brain-derived den-antigens. membrane fractions from infected cells separated by sucrose density gradient centrifugation were employed as antigen in serological tests with anti-den-2 infected suckling mouse brain hyperimmune mouse serum and hyperimmune mouse ascitic flui ... | 1978 | 25005 |
| cross reactions among flaviviruses in macrophage migration inhibition assay. | adult swiss albino mice were immunized intravenously with flaviviviruses. cellular immune response was studied by macrophage migration inhibition assay. migration of cells from sensitized mice was significantly inhibited in the presence of homologous virus or antigen. migration inhibition was also significant with serologically related viruses, thus establishing cross reaction in cellular immune response. | 1978 | 29477 |
| differential depletion of t lymphocytes in the spleen of dengue virus-infected mice. | following the i.c. inoculation of dengue type 2 virus (dv) the spleen weight of infected mice was reduced, as was the proportion of cells killed by ats and complement (t lymphocytes) in spleen-cell suspensions. in dv-infected mice the mean haemolysin titre, 16 days after i.p. inoculation of 4 x 10(8) srbc, was 47 compared with 406 in normal mice and spleen cells from dv-infected mice produced significantly reduced direct gvh reactivity in parker strain (ps) infant mice. adoptive transfer of sple ... | 1979 | 38205 |
| development of dengue virus plaques under serum-free overlay medium. | an improved plaque assay for dengue virus was developed utilizing baby hamster kidney (bhk-21) cells initially grown in shaker culture. different media preparations were tested for uniform and fast formation of bhk-21 cell sheets. several overlay formulas were tested to develop a rapid plaque assay in 6- and 24-well plastic plates. the best results were obtained utilizing eagle minimal essential medium (ph 7.2 to 7.4) supplemented with 1 mg of nahco3 per ml and 5% newborn calf serum for the form ... | 1979 | 39085 |
| [radial hemolysis reaction with arboviruses]. | a modification of the radial hemolysis test with arboviruses of the antigenic groups a and b was developed with sindbis, chikungunya, venezuelan equine encephalomyelitis, west nile, dengue 1 and 2 viruses. goose erythrocytes were sensitized with hemagglutinating sucrose-acetone antigens of these viruses from mouse brains at ph optimal for each virus. | 1979 | 41367 |
| a method for the isolation and identification of dengue viruses, using mosquito cell cultures. | an improved method for the isolation and identification of dengue viruses is described. viruses were isolated in mosquito cell cultures (c6/36 or ap-61), identified by indirect fluorescent antibody technique, and typed by complement-fixation test, using the cell culture fluid as antigen. the sensitivity of this method was compared with mosquito inoculation in comparative titrations of 16 low passage dengue virus strains. although lower virus titers were obtained by the mosquito cell culture tech ... | 1979 | 41456 |
| effects of cell culture and laboratory conditions on type 2 dengue virus infectivity. | the stability of type 2 dengue virus to exposure to a variety of laboratory conditions was determined. suckling mouse brain passage virus was adapted for growth in bhk-21 cells, and plaque assays were performed using a tragacanth gum overlay. a three- to fourfold increase in plaque size could be obtained if monolayers were subconfluent at time of inoculation. incubation of virus for 24 h at 37 degrees c, ph 6.5, or in buffer containing 1 mm ethylenediaminetetraacetate considerably reduced virus ... | 1979 | 41848 |
| [enzyme immunoassay for the detection and identification of dengue viruses from infected mosquitoes (author's transl)]. | the authors deal with a "double sandwich" enzyme immunoassay for the detection and identification of dengue viruses 1, 2 and 4. they use ground glass-beads (7 mm diameter) coated with human heterospecific anti-dengue antibodies, to bind viruses obtained from infected mosquitoes (toxorhynchites amboinensis). the mouse antibodies bound to the viruses coated on the beads are revealed by anti-mouse 7s immunoglobulins labelled with peroxydase. the method is practical, sensitive and confident. the sta ... | 1979 | 43691 |
| virological surveillance for dengue haemorrhagic fever in indonesia using the mosquito inoculation technique. | a dengue haemorrhagic fever surveillance system in indonesia, based on virological and clinical observations, is described. the system uses the mosquito inoculation technique for virus isolation and is simple, economical, and well suited for endemic areas where support and facilities are limited. the data suggest that with good cooperation between the hospital and the virology laboratory, new serotypes and possibly even new strains of virus can be identified before the onset of epidemic activity ... | 1979 | 43776 |
| [determination of arbovirus group affiliation in the indirect hemagglutination reaction]. | a dry polyvalent erythrocyte immunoglobulin diagnostic preparation for arboviruses of group b may be prepared to be used in the indirect hemagglutination test. the preparation detects antigens of arboviruses of this group in the tissue culture fluid and in suckling mouse brain tissue treated with sucrose-acetone. the test with group b arbovirus antigens is inhibited specifically by the homologous polyvalent immune gamma globulin. inhibition of hemagglutination by species-specific immune globulin ... | 1975 | 54999 |
| measurement of dengue virus-specific double-stranded ribonucleic acid in infected primate cell extracts by microquantitative complement-fixation methods. | microquantitative complement-fixation methods have been applied to the detection and quantitation of double-stranded rna (dsrna) in cytoplasmic extracts of uninfected and dengue virus-infected primate cell lines. llc-mk2 and pglc-33h cells exhibited increased levels of dsrna following dengue virus infection. cytoplasmic extracts of infected and uninfected llc-mk2 cells subjected to density gradient analysis showed that increased levels of dsrna were associated with structures believed to be viru ... | 1976 | 55393 |
| chemically-induced temperature sensitive mutants of dengue virus type 2. i. isolation and partial characterization. | temperature sensitive (ts) mutants of dengue virus type 2 (den-2, th-36 isolate) were induced by replication in primary hamster kidney cells treated with 5-azacytidine. seven ts mutants were obtained from 138 clones isolated by an immunofluorescent cloning technique. of these 7 ts mutants, 5 were sufficiently stable to permit partial characterization. complementation was detected at very low but statistically significant levels between some ts mutants at 40 degrees c. viral double-stranded rna p ... | 1976 | 56929 |
| chemically induced temperature-sensitive mutants of dengue virus type 2: comparison of temperature sensitivity in vitro with infectivity suckling mice, hamsters, and rhesus monkeys. | a series of temperature-sensitive (ts) mutants of dengue virus type 2 (den-2, th-36 isolate) were induced by treatment with 5-azacytidine. these mutants and parental viruses were compared for the ts trait and/or attenuation in four systems: primary hamster kidney cells, suckling mice, golden syrian hamsters, and rhesus monkeys. seven clones judged to possess the ts trait in virto demonstrated a variety of patterns in vivo. on initial isolation, five of seven ts mutants exhibited reduced mouse le ... | 1976 | 57925 |
| editorial: dengue. | | 1976 | 59247 |
| immunofluorescent staining of the surfaces of lymphocytes in suspension from patients with dengue hemorrhagic fever. | immunofluorescent staining of lymphocytes suspensions from 55 of 62 patients with dengue hemorrhagic fever was positive for dengue antigen and human beta1c/a-globulin on the surface, from the second ay before shock or subsidence of fever. the percentages of positive staining of both components gradually increased to a maximum on the day of shock or subsidence of fever. b lymphocytes increased during the course of the disease. neither dengue antigen nor human beta1c/a-globulin was detected on the ... | 1976 | 61729 |
| antigenic characterization of flavivirus structural proteins separated by isoelectric focusing. | isoelectrofocusing of nonionic-detergent-disrupted flaviviruses separated the envelope glycoprotein of 53,000 to 58,000 daltons and the nucleocapsid protein of 14,000 daltons. the envelope protein and nucleocapsid protein were isolated at isoelectric points of pi 7.8 and 10.3, respectively. the antigenic determinants of st. louis encephalitis, japanese encephalitis, and dengue virus envelope and nucleocapsid proteins were examined by solid-phase competition radioimmunoassay. by the appropriate s ... | 1977 | 69040 |
| studies on dengue hemorrhagic fever. iv. fluorescence staining of the immune complexes on platelets. | | 1977 | 71334 |
| isolation of dengue viruses in mosquito cell cultures under field conditions. | | 1978 | 74531 |
| encephalopathy associated with dengue infection. | | 1978 | 75481 |
| [the control of aedes (stegomyia) and related species involved in transmission of human arbovirus infections in tropical africa (author's transl)]. | in africa, many aedes mosquitos are involved in yellow fever and dengue transmission. their control can be carried out either in a "prophylactic" way, when no disease occurs, or in a "curative" one, when virus is detected in the human community. in the first event, control is confounded with sanitation measures; in the second event, insecticidal control is needed against both larvae and adults. larvae populations are destroyed by means of insecticidal deposits in the breeding-sites. control of a ... | 1978 | 85236 |
| effects of ca++ ion on the liberation of dengue virus from bhk-21 cells in culture. | | 1978 | 109743 |
| methylation status of intracellular dengue type 2 40 s rna. | | 1979 | 111410 |
| in vivo enhancement of dengue virus infection in rhesus monkeys by passively transferred antibody. | five pairs of juvenile, dengue virus-susceptible rhesus monkeys were given normal or dengue-immune human cord-blood serum injected intravenously to a final dilution of 1:300. the pool of immune human cord-blood serum had a titer of antibody to dengue type 2 virus (d2v) of 1:140 in the plaque-reduction neutralization test and a titer of human monocyte infection enhancement of greater than 1:2,000,000. fifteen minutes after inoculation of serum, animals were infected with d2v (strain no. 16681). d ... | 1979 | 117061 |
| effect of passage history on dengue-2 virus replication in subpopulations of human leukocytes. | three passage levels of dengue-2 virus strain pr-159, obtained during the course of deriving the attenuated s-1 vaccine, were tested for their ability to replicate in subpopulations of human peripheral blood leukocytes: (i) 6th primary african green monkey kidney (pgmk) cell passage (parent virus); (ii) 19th pgmk cell passage of a small-plaque-forming clone derived from the parent virus (s-1 pgmk virus); and (iii) virus derived by four additional passages of the s-1 pgmk virus in diploid fetal r ... | 1979 | 121109 |
| epidemiological features of dengue and chikungunya infections in burma. | a serological survey for antibody to dengue and chikungunya was carried out in all 14 divisions and states and 2 border towns in burma during 1973-74. dengue hi antibody prevalence rate of less than 10% was observed in arakan and shan states, 10 to 30% in the irrawaddy, pegu, mandalay divisions and kachin, mon and karen states, 31 to 60% in sagaing division, and over 60% in rangoon, magwe and tenasserim divisions. similarly, chikungunya hi antibody prevalence rate of less than 10% was observed i ... | 1975 | 126493 |
| the raji cell radioimmune assay for detecting immune complexes in human sera. | a sensitivie and simple procedure for the detection and quantitation of soluble complement (c)- fixing immune complexes in sera of patients with various disease states has been developed by utilizing c receptors on raji cells. these cells lack membrane-bound immunoglobulin but have receptors for igg fc, c3b, c3d, and possibly with other c proteins. uptake experiments showed that both aggregated human gamma globulin (ahg) and 7s igg bound to receptors for igg fc; however, ahg reacted with c bound ... | 1976 | 128562 |
| insecticide susceptibility of some vector fleas and mosquitoes in burma. | rat fleas and mosquitoes are insect vectors of public health importance in burma. plague is endemic in central burma and ddt has been the principal insecticide used for its control to date. dengue haemorrhagic fever, recently introduced and transmitted by aedes aegypti, has been spreading to major towns since 1971. the rodents, rattus rattus, r. exulans, bandicota bengalensis, mus musculus, as well as shrews were commonly caught during routine trapping in the country. rattus norvegicus, prevalen ... | 1975 | 131975 |
| isolation of dengue type 3 from mosquitoes in rangoon. | a virus was isolated in suckling mice from aedes aegypti collected from rangoon area, during the month of july 1969. the virus was identified as a member of group b arbovirus dengue type 3, by means of its ability to agglutinate goose erythrocyte at ph 6.6, haemagglutination inhibition and complement fixation tests, and its growth characteristics in aedes albopictus cell cultures. the isolated dengue type 3 virus differs slightly from the indian dengue type 3 virus in its ability to produce haem ... | 1976 | 140463 |
| [serologic surveys for the determination of antibodies against the eastern, western, california and st. louis encephalitis and dengue 3 arboviruses in central america, 1961-1975]. | | 1979 | 159062 |
| dengue virus-induced thymus-derived suppressor cells in the spleen of mice. | adoptive transfer of spleen cells obtained from mice given three weekly i.p. doses of dengue type 2 virus (dv) suppressed dv antigen-specific antibody secretion as detected by the jerne plaque technique. this suppression was produced by non-glass-adherent cells but not by glass-adherent cells. immune spleen cells depleted of macrophages by carbonyl iron treatment had higher suppressor activity. immune spleen cell homogenate could transfer the activity equally well. the immune spleen cells were s ... | 1979 | 160396 |
| studies on interferon induction and antiviral activity by certain arboviruses. | | 1975 | 170452 |
| prevalence of antibodies to arboviruses in egypt. results of a serologic survey among 1,113 university students. | | 1975 | 173201 |
| serologic examination of birds from the area of southern moravia for the presence of antibodies against arboviruses of the groups alfa, flavo, bunyamwera supergroup, and the virus yaba 1-lednice 110. i. domestic fowls. | 196 geese, 141 ducks, and 100 hens from 9 localities of the south moravian region (district of breclav) were examined by means of the haemagglutination-inhibition test (hit) for the presence of antibodies against 12 arbovirus antigens of the groups alfavirus (western equine encephalitis (wee), eastern equine encephalitis (eee), semliki, sindbis, chikungunya, o'nyong-nyong), flavovirus (tick-borne encephalitis (tbe), dengue and west nile virus (wn), bunyamwera supergroup (tahna and beta calovo), ... | 1975 | 175616 |
| the effect of dengue virus infection on the clinical sequelae of japanese encephalitis: a one year follow-up study in thailand. | in order to determine if prior dengue virus infection reduces the severity of japanese encephalitis (je), we examined 127 patients hospitalized during the 1970 je epidemic in the chiangmai and lampang valleys of northern thailand. patients were studied during the first 30 days after onset of je; 120 of these patients were examined one year later for residual neurologic sequelae. about 21% of patients had serological evidence of a prior dengue virus infection. morbidity and mortality in patients ... | 1975 | 176736 |
| timely topics in microbiology: viruses, 1973 i. | | 1976 | 181987 |
| dengue viruses and mononuclear phagocytes. ii. identity of blood and tissue leukocytes supporting in vitro infection. | studies were made on the identity of human and monkey mononuclear leukocytes permissive to antibody-enhanced dengue 2 virus (d2v) infection. in cultures of peripheral blood leukocytes (pbl) inoculated immediately after separation, it was concluded that only mononuclear phagocytes support dengue infection. this is based upon observations that d2v-permissive cells were resistant to 1,200 rads, were both plastic adherent and nonadherent, were removed when passed through nylon wool columns in 10 per ... | 1977 | 195000 |
| [in vitro demonstration of the cytotoxic activity of splenocytes sensitized to the tick-borne encephalitis virus]. | | 1977 | 201100 |
| phytohemagglutinin enhancement of dengue-2 virus replication in nonimmune rhesus monkey peripheral blood leukocytes. | phytohemagglutinin treatment of peripheral blood leukocytes from dengue nonimmune monkeys enhanced dengue-2 virus replication. enhancement was due primarily to an increase in the number of infected cells. destruction of mononuclear phagocytes with silica did not significantly inhibit virus replication in phytohemagglutinin-treated cultures. pokeweed mitogen, concanavalin a, and streptolysin o stimulated increased deoxyribonucleic acid synthesis in monkey leukocytes but did not enhance virus repl ... | 1978 | 203535 |
| serological evidence of infection of tacaribe virus and arboviruses in trinidadian bats. | sera from 39 species of bats collected in trinidad between 1972 and 1974 were tested against some or all of 18 arboviruses in hemagglutination inhibition (hi) and/or suckling mouse neutralization (n) tests. a few sera were hi-positive with mucambo, eastern equine encephalitis (eee), oriboca, restan, manzanilla, guama, bimiti, and catu. no sera were hi-positive with mayaro, caraparu or maguari. many ser inhibited one or more of the group b hemagglutinins: ilheus, st. louis encephalitis (sle), den ... | 1978 | 204207 |
| host defence mechanisms against dengue virus infection of mice. | serum obtained from mice 3 to 5 weeks after the third i.p. dose of dengue type 2 virus (dv) protected recipient mice against intracerebral challenge with dv, whereas the serum obtained after 1 and 2 weeks provided minimum protection. adoptive intravenous transfer of immune spleen cells obtained from mice 1 to 5 weeks after immunization did not protect recipient mice against even a small dose (10 ld50) of dv. depletion of t-cells by treatment of mice with anti-thymocyte serum did not potentiate d ... | 1978 | 206655 |
| biomedical survey in irian jaya (west irian), indonesia. | a biomedical survey was conducted in several areas of irian jaya, indonesia in july 1972 in association with an investigation of reports of a cholera outbreak. stool specimens, blood smears and sera were collected and examined for evidence of parasitic as well as other infectious diseases. a total of 114 stools were examined and the most commonly found intestinal parasites were trichuris trichiura (94%), ascaris lumbricoides (74%), hookworm (58%), entamoeba coli (15%), endolimax nana (8%), entam ... | 1977 | 208184 |
| replication of dengue and junin viruses in cultured rabbit and human endothelial cells. | the flavivirus dengue and the arenavirus junin are both associated with a hemorrhagic shock syndrome in man. we have demonstrated the replication of these viruses in vitro in both rabbit and human endothelial cells by viral titers and immunofluorescent antibody studies. rabbit endothelium established in continuous culture was derived from vena cava, while human cells in primary culture were derived from umbilical veins. in rabbit endothelium, dengue-2 virus passaged through monkey kidney monolay ... | 1978 | 208980 |
| [2 aspects of immunity in experimental flavivirus infections]. | experimentally, two aspects protective and damaging, of the immune response were demonstrated in the course of development of infection in mice inoculated with tickborne encephalitis (tbe) virus, langat, yellow fever, dengue type 2 or west nile viruses. the experiments were carried out in animals in which the functions of t- and b-lymphocytes, were temporarily inhibited with cyclophosphane (cp). it was demonstrated that the protective or damaging role of the immune response depended on the metho ... | 1978 | 211731 |
| recombinational repair of alkylation lesions in phage t4. ii. ethyl methanesulfonate. | treatment of bacteriophage t4 by ethyl methanesulfonate (ems) caused more than a doubling in recombination between two rii markers. the functions of genes 47, 46, 32, 30, uvsx and y are known to be required for genetic recombination, and mutants defective in these genes were found to be more sensitive to inactivation by ems than wild-type phage. this suggests that a recombinational pathway involving the products of these genes may be employed in repairing ems induced lethal lesions. genes 45 and ... | 1978 | 215891 |
| effects of mouse serum interferon and interferon inducers on dengue and japanese encephalitis virus infections in weanling mice. | | 1978 | 216848 |
| dimethyl sulfoxide enhancement of phlebotomus fever virus plaque formation. | dimethyl sulfoxide (dmso)incorporated into an agar overlay containing deae-dextran enhanced plaque formation in vero cells by naples sandfly fever virus passaged in mouse brain or vero cell cultures. no plaques were visible when dmso was used without the deae-dextran, some plaques were rarely visible (less than 0.5mm) when deae-dextran was used without the dmso, and up to 10-fold more plaques were clearly visible (0.5-1.5 mm) when both chemicals were used. the combined enhancing effect of dmso a ... | 1979 | 223461 |
| lymphocyte function and virus infections. | | 1979 | 230207 |
| subpopulation of peripheral blood lymphocytes in human encephalitis caused by group b arboviruses (dengue, west nile and japanese b encephalitis. | sera from twenty patients with clinically diagnosed viral encephalitis were studied during the acute and convalescent phases of illness for evidence of group b arboviral infection by demonstrating a rise in the titre of haemagglutination inhibiting (hi) antibodies. the immune status of these individuals was studied by quantitating peripheral t, t and 'null' lymphocytes. the percentage of total t cells in arboviral encephalitic (ae) group decreased significantly while that of b cells and 'active' ... | 1979 | 230259 |
| a serological survey of st lucia. | a serological survey of a random sample of 541 of the population of st lucia was undertaken. the prevalence of antibodies to dengue, herpes virus, vz, rotavirus, rubella and syphilis is described and compared with other communities. | 1979 | 232090 |
| pilot sero-epidemiological survey on japanese encephalitis in north-western burma. | a pilot sero-epidemiological survey of japanese encephalitis was carried out in three areas of north-western burma applying the hemagglutination-inhibition test. the existence of japanese encephalitis infection in these areas was confirmed and its incidences in these areas were estimated and compared graphically. | 1979 | 233227 |
| reactions of purified hemagglutinating antigens of flaviviruses with 19s and 7s antibodies. | the rapidly sedimenting hemagglutinin (rha) representing the purified virion and the slower-sedimenting hemagglutinin (sha) of several flaviviruses were separated and used in hemagglutination inhibition tests with the 19s (immunoglobulin m) and 7s (immunoglobulin g) immunoglobulin fractions of rabbit antisera, prepared against purified viral antigens or against crude virus pools. the antibody specificity in tests with rha was identical to the specificity in those employing sha. 7s antibody cross ... | 1975 | 235489 |
| thermal inactivation of type 1 dengue virus strains. | | 1975 | 239566 |
| type 3 and type 4 dengue in medan, north sumatra. | | 1975 | 240947 |
| an epidemic of dengue fever in wewak. | 143 clinical cases of dengue fever were reported in wewak between april and august 1976. 15 patients demonstrated a diagnostic rise in antibody titre for group b arbovirus. tests for complement-fixing antibody to dengue viruses did not indicate what type of dengue virus was responsible for the epidemic. vector species aedes aegypti and aedes scutellaris were found before control measures were adopted but were not found four months later. the epidemiology of dengue fever is discussed and measure ... | 1978 | 279165 |
| viral haemorrhagic fevers of man. | this article reviews the current state of knowledge on the viral haemorrhagic fevers that infect man, namely smallpox, chikungunya fever, dengue fever, rift valley fever, yellow fever, crimean haemorrhagic fever, kyasanur forest disease, omsk haemorrhagic fever, argentinian haemorrhagic fever (junin virus), bolivian haemorrhagic fever (machupo virus), lassa fever, haemorrhagic fever with renal syndrome, and marburg and ebola virus diseases. | 1978 | 310725 |
| an epidemic of rift valley fever in egypt. 1. diagnosis of rift valley fever in man. | rift valley fever (rvf) virus was isolated from 53 of 56 sera collected from patients with a clinical picture of dengue-like illness during the peak of the epidemic of rvf in egypt in the autumn of 1977. rvf virus was also isolated from the throat washings of two patients and the faeces of four, all of whom were positive for virus isolation from the serum. all the isolates were identified by the complement fixation (cf) test. serological diagnosis of rvf, using paired sera from 16 patients, was ... | 1979 | 314354 |
| suppression of intrinsic b-cell function in dengue-infected mice. | mice infected with dengue virus show a depressed immune response to lipopolysaccharide (lps), a helper t-cell-independent antigen, when lps was administered on day 0, 6 and 12 post infection. mice injected with inactivated virus failed to show immunosuppression. | 1979 | 315884 |
| a simple technique for the detection of dengue antigen in mosquitoes by immunofluorescence. | dengue antigen could be demonstrated by a direct fluorescent antibody technique in simple head squashes of either male or female aedes albopictus mosquitoes infected with any of the four dengue serotypes. dengue viruses can be isolated rapidly and simply by combining this technique with that of parenteral inoculation of mosquitoes with test material. | 1977 | 326071 |
| infections with two dengue viruses in greece in the 20th century. did dengue hemorrhagic fever occur in the 1928 epidemic? | from contemporary clinical accounts we hypothesized that the 1928 dengue epidemic in greece may have been an earlier occurrence of dengue hemorrhagic fiver/dengue shock syndrome (dhf/dss). to study the possibility that two different dengue viruses may have been involved, serums from 62 athenians alive during the epidemic were examined for dengue antibodies; 73 per cent showed evidence of prior dengue infection. monotypic neutralizing antibodies were found to two different dengue viruses, types 1 ... | 1977 | 327086 |
| an application of pap (peroxidase-anti-peroxidase) staining technique for the rapid titration of dengue virus type 4 infectivity. | | 1977 | 328006 |
| dengue viruses. | | 1977 | 337651 |
| participation of hageman factor dependent pathways in human disease states. | abnormalities of hageman factor dependent pathways have been described in a wide variety of human disease states. congenital deficiencies of factor xii (hageman trait) prekallikrein (fletcher trait) and high molecular weight kininogen (williams, fitzgerald and flaujeac traits) although resulting in profound in vitro changes, do not cause in vivo difficulties. in contrast, deficiency of c1 esterase inhibitor (hereditary angioedema) results in significant morbidity and mortality. acquired diseases ... | 1977 | 341410 |
| evidence for the in vitro production of migration inhibition factor by sensitized mouse spleen cells stimulated with dengue virus. | | 1978 | 352920 |
| the defined antigen substrate sphere system with direct immunohistoperoxidase for detection of soluble dengue antigen in sera of patients with dengue hemorrhagic fever. | the defined antigen substrate sphere system is a simple method for detecting antigen or antibody in the circulation. the technic is based on the coupling of antigen or antibody with sepharose 4b beads that have been activated by cyanogen bromide. in this study the activated beads were exposed to dengue antigen in the serum from a patient with dengue hemorrhagic fever and then stained with antidengue antibody conjugated with horseradish peroxidase. the positive reaction showed brown beads by ligh ... | 1978 | 360820 |
| immunoglobulin g- and m-specific enzyme-linked immunosorbent assay for detection of dengue antibodies. | an enzyme-linked immunosorbent assay for the detection of antibodies to dengue virus is described. this method correlates well with a hemagglutination inhibition technique. the enzyme-linked immunosorbent assay can also be specific for human immunoglobulin m antibodies when a mu-chain-specific antiglobulin-enzyme conjugate and fractionated serum are employed. by using this technique, dengue immunoglobulin m antibodies were demonstrated in an infant suspected of having a recent dengue infection. | 1979 | 379040 |
| neutralization tests for dengue and japanese encephalitis viruses by the focus reduction method using peroxidase-anti-peroxidase staining. | neutralization tests were made on 4 types of dengue (den) virus and japanese encephalitis (je) virus by incubation of serially diluted antisera and constant amounts of the viruses and then focus assay of surviving virus infectivity with peroxidase-anti-peroxidase (pap) staining. neutralization reactions were virtually completed in 2 hr on incubation of serum-virus mixtures at 28 c. a straight regression line was obtained on a probit chart by plotting the focus reduction rates at various dilution ... | 1978 | 383069 |
| demonstration of dengue antibody complexes on the surface of platelets from patients with dengue hemorrhagic fever. | by the direct immunofluorescent technic, dengue antigen, human immunoglobulins, and beta 1c globulin were detectable on the surfaces of platelet suspensions from 48% of patients with dengue hemorrhagic fever. the percentages of positive-staining platelets were not related to the severity of thrombocytopenia, which was marked on the day after the patient developed shock or subsidence of fever. it is suggested that an immunologic mechanism is one of the factors associated with the thrombocytopenia ... | 1979 | 384817 |
| study of arboviruses in romania (1958--1978). results obtained in the "stefan s. nicolau" institute of virology. | the results obtained in the institute of virology by the study of arboviruses in romania are reviewed. isolation of tick-borne encephalitis virus and detection of specific serum antibodies in humans, animals and migratory birds demonstrate its presence on the territory of romania. serum antibodies could also be detected to other three flaviviruses (west nile, ntaya, dengue types 1, 2, 3), though none of them could be isolated in our country. however, isolation of kemerovo and tahyna viruses and ... | 1979 | 392912 |
| fluorescent antibody studies on the development of dengue-2 virus in aedes albopictus (diptera: culicidae). | | 1979 | 396372 |
| nonspecific immunofluorescent staining of mosquito salivary gland. | | 1979 | 397344 |
| a modified pap (peroxidase-anti-peroxidase) staining technique using sera from patients with dengue hemorrhagic fever (dhf): 4 step pap staining technique. | bhk-21 cells infected with dengue virus type 1 were stained by a newly developed 4 step pap (peroxidase-anti-peroxidase) technique using sera from patients with dengue hemorrhagic fever as anti-virus antibody. the intensity of staining of the sera was proportional to the hemagglutination inhibition and neutralization titers. with this new technique using sera from patients it should be possible to use the pap technique of virus infections. | 1979 | 399586 |
| immunological sensitization following inapparent infection with dengue virus type 3 in rhesus monkeys. | rhesus monkeys previously given dengue virus type 3, without apparent viremia or antibody response, exhibited a secondary-type response upon reinoculation. these data suggest that monkeys can be immunologically sensitized to dengue virus without detectable antibody production. | 1977 | 404181 |
| antibody-enhanced dengue virus infection in primate leukocytes. | | 1977 | 404559 |
| dengue virus infections in nigeria: a survey for antibodies in monkeys and humans. | a retrospective serological survey for dengue immunity was conducted in nigeria to determine the prevalence of infection in man and non-human primates. preliminary haemagglutination-inhibition (hi) tests revealed that 63% of persons tested had hi antibodies against one or more of the following flaviviruses: dengue type 1, yellow fever, west nile and wesselsbron. parallel hi and neutralization (n) tests on 179 human sera showed that six of 20 sera (30%) negative for flavivirus hi antibody contain ... | 1977 | 404737 |
| dengue viruses and mononuclear phagocytes. i. infection enhancement by non-neutralizing antibody. | cultured mononuclear peripheral blood leukocytes (pbl) from nonimmune human beings and monkeys are nonpermissive to dengue 2 virus (d2v) infection at multiplicities of infection of 0.001-0.1, but become permissive when non-neutralizing dengue antibody is added to medium. d2v infection occurred in pbl prepared from anti-coagulated but not from defibrinated plasma. infection enhancement was produced by multiple lots of heterotypic anti-dengue raised in several mammalian species. homotypic anti-den ... | 1977 | 406347 |
| virulence and immunogenicity of a temperature-sensitive dengue-2 virus in lower primates. | clones of dengue-2 virus were tested for virulence by inoculation of rhesus monkeys and chimpanzees. although primates showed no overt signs of illness, inoculation with the parent virus or a subline of a large-plaque clone resulted in a viremia lasting 1 to 7 days. by these criteria, sublines of a small-plaque clone were significantly less virulent and produced little or no viremia in primate hosts. although they had a substantially reduced viremia, primates inoculated with the small-plaque sub ... | 1977 | 409682 |
| cultivation of dengue virus type 2 in candidate substrates for vaccine production. | | 1978 | 415061 |
| rapid detection of dengue viral antigens by counterimmunoelectrophoresis. | counterimmunoelectrophoresis (cie) was applied to detect dengue viral antigen in an experimental system and in clinical situations. in the experimental system, all four types of dengue viruses (dengue 1 to 4) were detected when tested against rabbit hyperimmune sera. with homologous antibody, antigen could be detected when hemagglutinating titer was as low as 1:20. in clinical situations, 67% of the sera of patients with dengue hemorrhagic fever collected on day 4 after onset of fever were posit ... | 1979 | 420162 |
| [dengue, an imported disease in the netherlands]. | | 1979 | 440463 |
| the ultrastructures of dengue type 1 virus in the aedes pseudoscutellaris mosquito cell line. | | 1979 | 442167 |
| dengue in the caribbean: virus isolation in a mosquito (aedes pseudoscutellaris) cell line. | during outbreaks of dengue fever in the caribbean in 1977 and 1978 a continuous cell line derived from aedes pseudoscutellaris was successfully used for the isolation of dengue virus strains from acute human sera. 238 strains were isolated and culture fluid was successfully used as antigen for the identification of several strains. the isolates all produced a marked syncytial cytopathic effect often visible as early as four days after inoculation. the method was successfully employed in the fiel ... | 1979 | 442177 |
| geographic distribution of arbovirus antibodies in indigenous human populations in the indo-australian archipelago. | sera from lifetime residents in 16 localities of the indo-australian archipelago and adjacent areas were tested for hemagglutination-inhibition antibody against four alpha-viruses (sindbis, getah, chikungunya, and ross river) and for neutralizing antibody against six flaviviruses (dengue 2 and 3, japanese encephalitis, murray valley encephalitis, kunjin, and edge hill). mosquito collections were carried out in some of the localities to study vector relationships to distribution of the arbovirus ... | 1979 | 453438 |
| absence of leukocytes permissive to dengue 2 virus in the acute phase of dengue hemorrhagic fever. | patients with primary dengue infection developed dengue 2 virus (d2v) permissive peripheral blood leukocytes (pbl) 2--3 weeks after infection. pbl from healthy individuals with dengue antibody were permissive to d2v in vitro, suggesting that immunologically mediated in vitro d2v permissiveness persists for a relatively long time after recovery from dengue infection. however, pbl obtained from second infection dengue hemorrhagic fever patients did not support d2v growth during the acute phase of ... | 1979 | 453450 |
| isolation of dengue virus from trichur district (kerala state). | | 1979 | 457191 |
| epidemic dengue hemorrhagic fever in rural indonesia. i. virological and epidemiological studies. | virological studies were carried out during an epidemic of dengue hemorrhagic fever in central java, indonesia in 1976. dengue virus was isolated from the acute sera of 45 of 69 patients (65%). the isolation rate was higher in primary than secondary cases. dengue 3 was the predominant serotype being transmitted (27 isolates), but both dengue 1 (8 isolates) and dengue 4 (10 isolates) were also being transmitted. a composite picture of magnitude and duration of viremia showed that many patients we ... | 1979 | 464191 |
| epidemic dengue hemorrhagic fever in rural indonesia. ii. clinical studies. | clinical observations were made on 95 serologically or virologically confirmed dengue fever cases during an epidemic in a rural area of indonesia in december 1976. the age distribution was similar to that observed in patients with dengue hemorrhagic fever in jakarta, a highly endemic urban area. the observed disease ranged in severity from undifferentiated fever to shock and death. the majority of patients had acute onset of fever with nausea, vomiting, headache, and abdominal pain. hepatomegaly ... | 1979 | 464192 |
| epidemic dengue hemorrhagic fever in rural indonesia. iii. entomological studies. | entomological studies were carried out during a dengue hemorrhagic fever epidemic in central java in december 1976. both aedes aegypti and aedes albopictus were widely distributed in bantul, but the latter species was more abundant. comparative studies on the vector competence of the two species showed that ae. albopictus had a higher susceptibility than ae. aegypti to oral infection with all four dengue serotypes. the two species were equally compentent in transmitting the bantul strain of deng ... | 1979 | 464193 |
| characteristics of aedes albopictus cells persistently infected with dengue viruses. | | 1979 | 471048 |
| proteins specified by togaviruses in infected aedes albopictus (singh) mosquito cells. | yields of greater than 10(7) p.f.u./ml at 28 or 37 degrees c of the alphavirus sindbis and the flavivirus kunjin were obtained in the aedes albopictus (singh) cell line, the latent periods being 4 to 6 and 10 to 12 h, respectively. despite a high background of host protein synthesis, virtually all the virus-specified proteins of the flaviviruses kunjin, dengue-2 and japanese encephalitis were labelled and resolved by slab gel electrophoresis of infected and uninfected cell proteins. in contrast, ... | 1979 | 479844 |
| dengue hemorrhagic shock in the western hemisphere. | a 39-year-old man after visiting an endemic dengue area during a local outbreak developed a febrile illness complicated by skin petechiae, bleeding, shock, hemoconcentration, and death. the presumptive diagnosis of dengue was made based on hemagglutination inhibition and complement fixation titers in a single sample. the serologic evidence and ancillary laboratory findings are compatible with a secondary antibody response. | 1979 | 483366 |
| cultivation of dengue virus type 2 in baby hamster kidney cells in serum-free medium. | propagation of dengue virus type 2 (new guinea c strain) was performed using a shaker culture of baby hamster kidney cells (bhk-21) cultivated in serum-free modified waymouth medium. maximum virus titer varied from 10(8.3) to 10(8.8) plaque forming units/ml after incubation of bhk-21 cells in suspension culture at 37 dgrees c for 40-48 hours post-infection. | 1979 | 484777 |
| zika virus infections in nigeria: virological and seroepidemiological investigations in oyo state. | a study of zika virus infections was carried out in four communities in oyo state, nigeria. virus isolation studies between 1971 and 1975 yielded two virus isolations from human cases of mild febrile illness. haemagglutination-inhibition tests revealed a high prevalence of antibodies to zika and three other flaviviruses used. the percentages of positive sera were as follows: zika (31%), yellow fever (50%), west nile (46%), and wesselsbron (59%). neutralization tests showed that 40% of nigerians ... | 1979 | 489960 |
| dengue virus isolation in indonesia, 1975-1978. | virus isolations from dengue hemorrhagic fever patients in indonesia are reported from 1975 to 1978. all 4 dengue serotypes were endemic in jakarta, but dengue 3 was the predominant virus isolated. this type was also the most frequently isolated virus from patients outside jakarta and had the widest distribution in indonesia. the sensitivity of the mosquito inoculation technique for isolation of dengue viruses is discussed. | 1979 | 496711 |
| antibody-mediated enhancement of flavivirus replication in macrophage-like cell lines. | interactions between animal viruses and antiviral antisera may exceptionally result in an apparent increase in viral infectivity. halstead and coworkers demonstrated enhanced replication of dengue virus (a flavivirus, family togaviridae) in human or simian peripheral blood leucocytes carrying fc receptors at subneutralising concentrations of antidengue antibody. we have used three continuous cell lines which express macrophage markers to explore the mechanism of this phenomenon. dengue virus fai ... | 1979 | 503230 |
| serological evidence of dengue virus activity in children on the northern leeward islands (netherlands antilles). | an arbovirus serologic survey of school children on the northern leeward islands (saba, st. eustatius and st. maarten) using haemagglutination inhibition (hi) detected a high proportion of reactors to dengue types 1,2, and 3. analysis in relation to age showed an increasing proportion to be positive with increasing age. the results of an all-age survey on st. eustatius 1970 led to the hypothesis of possible dengue serotype 1 activity on st. eustatius around 1900, whilst it is thought that dengue ... | 1979 | 505553 |