| equine viral encephalitis. | the most important neurotropic viral infections of the horse are the arthropod-borne encephalitides. these include venezuelan encephalitis (ve), eastern encephalitis (ee) and western encephalitis (we), which are found in the americas, and japanese b encephalitis which occurs in the far east. all the viruses cause encephalitis in man. between 1969 and 1972 an epidemic of ve occurred in central america. in 1971 the disease was reported in texas, where it was brought under control by the vaccinatio ... | 1976 | 4301 |
| antiviral effect of tebrofen. | tebrofen inhibited the replication of western equine encephalomyelitis (wee) virus in multicycle experiments in chick embryo cell cell cultures. the compound did not inhibit the replication of vaccinia and newcastle disease viruses. | 1977 | 18926 |
| isolation of the structural proteins of western equine encephalitis virus by isoelectric focusing. | western equine encephalitis virus was disrupted with triton x-100 and subjected to isoelectric focusing in a sucrose or urea gradient. the two envelope proteins, e1 and e2 were not well separated in a sucrose gradient, while the e1 and e2 proteins were distinguished as two major peaks which focused in a urea gradient at about ph 7.5 and 10, respectively. isolated e1 protein refocused at ph 6.5 in a sucrose gradient isoelectric focusing column. when western equine encephalitis virus was treated w ... | 1979 | 41505 |
| spontaneous and induced mutagenesis in western equine encephalomyelitis virus in chick embryo cells with different repair activity. | evidence was obtained indicating differences in the survival rate of western equine encephalomyelitis virus after exposure to ultraviolet radiation and methyl methanesulfonate in commercial and leukosisfree chick embryo cells that differed in repair activity. the levels of spontaneous mutagenesis (on the basis of the yield of small palque variants of the encephalomyelitis virus) did not essentially change when the virus was passage in leukosis-free chick embryo cells, whereas an increase in the ... | 1975 | 164025 |
| a serologic survey of pronghorns in alberta and saskatchewan, 1970-1972. | to determine the exposure of free-ranging pronghorns (antilocapra americana ord) to selected pathogens, serum samples were obtained from 33 live-trapped animals from southwestern saskatchewan in 1970, and from 26 and 51 animals from southeastern alberta, in 1971 and 1972, respectively. antibodies were found to the agents of parainfluenza 3, bovine virus diarrhea, eastern and western encephalomyelitis, infectious bovine rhinotracheitis and the chlamydial group. no serologic reactors were found to ... | 1975 | 167203 |
| the effect of tilorone hydrochloride on the growth of several animal viruses in tissue cultures. | tilorone hydrochloride, at a concentration of 10 mug/ml inhibits the growth of herpes simplex virus type 1 in bs-c-1 cells. the growth of vaccinia virus in bs-c-1 cells is partially inhibited; however, six viruses containing rna, including four members of the togavirus group grown in chick fibroblasts, are not affected by the drug. the inhibition of the growth of herpes virus by tilorone hydrochloride is greater when the multiplicity of infection is lower than 1 p.f.u/cell and when the drug is a ... | 1976 | 177724 |
| viral infection and interferon in cell cultures aged in vitro. | cells from leucosis-free chick embryos (skin and muscles), grown in vitro 1 and 7 days with no medium change, are used as a model for young dividing and stationary in vitro aged cells, respectively. aged cultures are advantageous for if induction by cytopathic and noncytopathic viruses. decreased virus production in them is ascribed to a back effect of the early formed if onto the inducing virus. a factor which stimulates viral if interferon induction also in young cultures, is released from age ... | 1975 | 164104 |
| fetal mortality and malformations associated with experimental infections of western equine encephalomyelitis vaccine virus in rhesus monkeys (macaca mulatta). | pregnant rhesus monkeys were infected via installation of western equine encephalomyelitis (wee) vaccine virus into the amniotic sacs at 50 and 80 days gestation to determine if the resulting infections would produce fetal mortality or fetal malformations, particularly within the central nervous system. of those receiving virus at 50 days gestation, 13 of 18 fetuses were aborted or dead in utero at time of caesarean section; 2 of 18 were malformed (hydrocephalus and polyarthrosis); and 3 of 18 w ... | 1979 | 117565 |
| inhibition of dna synthesis in bhk cells infected with western equine encephalitis virus. 2. properties of the inhibitory factor of dna polymerase induced in infected cells. | | 1979 | 228480 |
| effects of influenza, mumps, and western equine encephalitis viruses on fetal rhesus monkeys (macaca mulatta). | pregnant rhesus monkeys were infected via instillation of influenza, mumps and western equine encephalomyelitis viruses respectively into the amniotic sacs at approximately 90 days gestation to determine if fetal infections would occur. virus was recovered from fetal tissues after seven days in 100% of the exposed animals. thus, the viruses are capable of causing fetal infection. rhesus monkey fetuses were inoculated with influenza, mumps and wee viruses by the direct intracerebral route at appr ... | 1979 | 117564 |
| [intensification of antibacterial and antiviral nonsusceptibility and of the immune response with an officinal rna preparation]. | sodium nucleinate increased essentially the insusceptibility of mice to pathogenic escherichia, strain o26, pr. vulgaris, ps. aeruginosa, ser. marcescens, and produced a total stimulating effect on the nonspecific bacterial resistance; analogous stimulating activity was found in the homologous low polymeric rna from the liver. sodium nucleinate intensified the insusceptibility of the animals to the tick-born encephalitis and encephalomyelitis viruses, and increased the antibody-forming cells cou ... | 1979 | 106911 |
| interaction of mouse peritoneal macrophages with different arboviruses in vitro [proceedings]. | | 1976 | 66026 |
| correlation between virus-cell receptor properties of alphaviruses in vitro and virulence in vivo. | virulent and avirulent clones of venezuelan, western, and eastern equine encephalitis viruses were examined for their in vitro attachment characteristics to the surface of cultured cell monolayers. these attachment characteristics were correlated with in vivo plasma clearance rates and virulence. for the clones investigated, avirulence correlated in vitro with attachment ph optima close to physiologic ph and in vivo with a rapid clearance from plasma. conversely, virulent clones had lower in vit ... | 1979 | 295182 |
| antiviral effects of double-stranded rna from rice dwarf virus on infection of mice with western equine encephalitis virus. | a single administration (1 to 10 mg/kg) of rice dwarf virus rna (rdv-rna) prior to virus challenge reduced the mortality of mice infected with western equine encephalitis (wee) virus. the protective effect of rdv-rna was significantly higher than that of polyinosinic-polycytidylic acid. however, when these rnas were given after virus infection, the protective effect was negligible. the titer of circulating interferon in mice reached a peak about 5 hr after injection of these rnas and remained at ... | 1977 | 333233 |
| variations in the susceptiblility of field and laboratory populations of culex tarsalis to experimental infection with western equine encephalomyelitis virus. | four field populations and four laboratory colonies of culex tarsalis from california were evaluated for their susceptibility to infection with western equine encephalomyelitis (wee) virus by intrathoracic inoculation and by feeding on pledgets soaked with a virus-blood-sucrose mixture. all mosquito strains were uniformly susceptible to infection by intrathoracic inoculation, but 50% infective doses for field and colonized strains varied as much as 1000- to 1500-fold, respectively, by pledget fe ... | 1976 | 58557 |
| a microprecipitation test for rapid detection and identification of venezuelan, eastern and western equine encephalomyelitis viruses. | the development of a new diagnostic procedure for the identification of venezvelan, eastern and western equine encephalomyelitis (vee, eee, wee) viruses is described. the procedure utilizes virus precipitation with reference fluorescein-conjugated gamma globulin, followed by cellulose acetate electrophoresis. clinical specimens containing varying concentrations of virus yielded, in primary duck embryo cell culture, sufficient virus for detection within 22 to 44 hours. identification of vee, eee ... | 1975 | 46134 |
| antiviral activity of benzothiazole and benzothiazolinethione derivatives in cell cultures. | the virus inhibitory activity of benzothiazole, benzothiazolinethione and naphthothiazole derivatives was tested with vaccinia virus, newcastle disease virus (ndv) and western equine encephalomyelitis (wee) virus in the agar-diffusion plaque-inhibition test. among 58 compounds examined, 5 showed medium activity and selectivity with vaccinia virus. the highest selective effect was found with 3-(2-ethylthio-6-benzothiazolylaminomethyl)-2-benzothiazolinethione. a much lower inhibitory effect was ob ... | 1979 | 41432 |
| vector competence of colonized culiseta melanura (diptera: culicidae) for western equine encephalomyelitis virus. | | 1979 | 35613 |
| variations in biological properties of geographic strains of western equine encephalomyelitis virus before and after passage in culex tarsalis and culiseta melanura. | western equine encephalomyelitis (wee) virus strains from the eastern and western united states were compared using two biological markers: antigenic properties measured by cross complement fixation (cf) tests and the size of plaques produced in vero cell cultures. slight antigenic differences were discernible on a geographic basis, and all of the virus strains from the west produced significantly larger plaques than the eastern isolates. one virus strain from each region was serially passaged i ... | 1978 | 30265 |
| mosquito-virus relationships of american encephalitides. | | 1978 | 24407 |
| occurrence and distribution of western equine encephalomyelitis in florida. | research and surveillance programs relating to the occurrence and distribution of western equine encephalomyelitis virus in florida, conducted between 1955 and 1976, suggest that the virus is (1) an endemic arbordae, (2) transmitted in a continuous cycle throughout the year by culiseta melanura mosquitoes, and (3) restricted to fresh water swamps and waterways in central, north, and northwest florida. | 1978 | 23372 |
| chromatographic separations of alphavirus strains by hydroxylapatite. | hydroxylapatite column chromatography methods were developed to characterize selected alphavirus populations. different conditions of ph and phosphate molarity were required to obtain satisfactory elution profiles and separations for western equine encephalomyelitis virus strains, compared with eastern equine encephalomyelitis virus and semliki forest virus strains. raising the ph of the buffers effected earlier elutions of all viruses. selection of phosphate gradients with more gentle slopes an ... | 1977 | 20452 |
| ecology of keystone virus, a transovarially maintained arbovirus. | our studies in the pocomoke cypress swamp of maryland have shown that key strain of ce is endemic and is carried by the floodwater mosquito a. atlanticus. the virus is transmitted transstadially in nature, as evidenced by our recovery of virus from larvae and males of this species. serologic evidence, both here and elsewhere, indicates that vertebrates are infected with key, but their role in the transmission cycle remains unknown. we have found several animals, for example, the gray squirrel, t ... | 1975 | 20017 |
| ecology of western equine encephalomyelitis in the eastern united states. | | 1977 | 16462 |
| buoyant density of some togaviruses in sucrose density gradient and capacity of their haemagglutinin fractions to interact with antibody. | the buoyant densities of western equine encephalomyelitis virus (an alphavirus) and tick-borne encephalitis (tbe) virus (a flavivirus) antigens prepared by different methods were studied. sucrose density centrifugation revealed a heterogeneity in the density of the virions. the sedimentation pattern and height of peaks of the haemagglutinating activities and infectivity, other conditions being equal, depended both on the virus species and properties of its strains and on the mode of preparation ... | 1976 | 11662 |
| study of homologous and heterologous antibody response in california horses vaccinated with attenuated venezuelan equine encephalomyelitis vaccine (strain tc-83). | of 359 horses vaccinated with attenuated venezuelan equine encephalomyelitis (vee) vaccine (strain tc-83), 87% developed hemagglutination-inhibition (hi) antibodies to vee virus within 1 month. blood from a subsample of 101 of the 359 horses was obtained over a 1-year period. within 1 month after vaccination, 84% of the 101 horses had developed vee hi antibodies, 87% had developed vee-neutralizing (nt) antibodies, and 78% had developed vee complement-fixing (cf) antibodies. one year after vaccin ... | 1978 | 637386 |
| mosquito surveys in manitoba during 1975. | | 1976 | 9196 |
| laboratory diagnosis of western encephalomyelitis. | | 1976 | 9195 |
| arbovirus surveillance in six states during 1972. | a virus surveillance project was established and maintained during 1972 along 10 major river drainages in six states. mosquitoes, biting flies, and blood specimens from sentinel equines were collected during 83 field trip visits to 141 arthropod collecting sites and 22 sentinel locations from april into december 1972. there were 173,074 mosquitoes tested and 303 arboviruses isolated from 11 of 41 species. from 13,388 biting flies tested, 8 arbovirus isolations were obtained in 1 of 5 species. th ... | 1976 | 7148 |
| mosquito-borne arboviruses in arctic america. | mosquito-borne arboviruses are prevalent throughout subarctic regions of canada and alaska, principally in the boreal forest extending between latitudes 53 and 66 degrees n, but they have been identified in tundra regions as far north as 70 degrees n. all mosquito-borne agents have been bunyaviruses, comprising principally the snowshoe hare subtype of california encephalitis (ce) virus, but also northway virus. mosquito vectors comprise several aedes species and culiseta inornata, all of which h ... | 1975 | 1602 |
| necrotizing myocarditis in mice infected with western equine encephalitis virus: clinical, electrocardiographic, and histopathologic correlations. | western equine encephalitis (wee) virus was found in myocardial tissue of adult mice during the first five days after inoculation of the virus, with a peak titer (5.0 log plaque-forming units/g) at 24 hr. light microscopy revealed a multifocal necrotizing myocarditis with a prominent inflammatory response and hyaline and granular degeneration of myofibers. electron microscopy showed cytoplasmic viral nucleoids and budding and free mature wee viral particles. serial electrocardiograms showed the ... | 1978 | 681791 |
| photochemical inactivation of dna and rna viruses by psoralen derivatives. | western equine encephalitis virus, and rna virus, and herpes simplex virus type i, a dna virus, were efficiently inactivated in less than i min by exposure to long-wave ultraviolet light (320 to 380 nm) in the presence of several psoralen derivatives. the psoralen photochemical reaction was chosen for study due to its known specificity for nucleic acids. neither the light nor any of the drugs alone caused appreciable inactivation. the inactivation kinetics and dependence on light intensity and o ... | 1978 | 211184 |
| variables affecting viral plaque formation in microculture plaque assays using homologous antibody in a liquid overlay. | a liquid antibody microculture plaque assay and the variables that govern its effectiveness are described. the assay is based on the principle that low concentrations of homologous antibody can inhibit secondary plaque formation without inhibiting formation of primary plaques. thus, clear plaques that followed a linear dose response were produced. the assay was found to be more rapid, less cumbersome, and less expensive than assays using agar overlays and larger tissue culture plates. it was rep ... | 1977 | 194918 |
| [antiviral effect of acridine derivative c 283]. | | 1976 | 176540 |
| prevalence of antibodies to arboviruses in egypt. results of a serologic survey among 1,113 university students. | | 1975 | 173201 |
| sensitivities of neurotropic arboviruses to human interferon. | the sensitivities of selected neurotropic arboviruses (st. louis encephalitis, western equine encephaltis, and la crosse viruses) to human interferon and polyriboinosinic-polyribocytidylic acid (poly i-poly c) were determined in primary human fetal glial cell cultures. the sensitivities were measured by an end point (inhibition of virus yield). all of the viruses were sensitive to human interferon and poly i-poly c; st. louis encephalitis and western equine encephalitis viruses were inhibited at ... | 1975 | 171314 |
| prolonged western equine encephalitis viremia in the texas tortoise (gopherus berlandieri). | subcutaneous inoculation of 34 texas tortoises (gopherus berlandieri) with either of two strains of western equine encephalitis (wee) virus resulted in prolonged viremia of up to 105 days' duration. peak viremia titers exceeded 10(6) suckling mouse intracranial lethal doses per milliliter. the length of the previremic period, the maximum viremia level attained, and the duration of viremia were markedly affected by environmental temperature. higher temperatures (30 degrees c) shortened the previr ... | 1977 | 842780 |
| antiviral activity of virus-like particles from lentinus edodes (shiitake). brief report. | interferon (if) induction and antiviral activity by purified spherical (s) or filamentous (f) virus-like particles and s-derived rna was studied. a single administration of s particles prior to virus challenge reduced significantly the mortality of mice infected with western equine encephalitis (wee) virus. | 1979 | 222241 |
| arbovirus vector ecology studies in mexico during the 1972 venezuelan equine encephalitis outbreak. | virus vector studies were conducted in the states of durango, chihuahua, and tamaulipas, mexico, in june and july 1972. apparently only a low level of venzuelan equine encephalitis (vee) virus transmission to equines occured at the time of the study, and the infection was restricted to areas which had not experienced overt activity during the preceding year. the low level of infection was associated with a scarcity of mosquitoes. the ib (epidemic) strain of vee virus was isolated from two pools ... | 1975 | 235213 |
| ecological studies of culiseta melanura (diptera: culicidae) in relation to eastern and western equine encephalomyelitis viruses on the eastern shore of maryland. | | 1975 | 235650 |
| a supportive treatment for equine viral encephalitis. | | 1977 | 244159 |
| other possible pathogens in the fetus and newborn. | | 1978 | 340800 |
| complementation between temperature-sensitive mutants isolated from aedes albopictus cells persistently infected with western equine encephalitis virus. | | 1979 | 425324 |
| inhibition of dna synthesis in bhk cells infected with western equine encephalitis virus. 1. induction of an inhibitory factor of cellular dna polymerase activity. | | 1979 | 452420 |
| studies on immunity to alphaviruses in foals. | | 1979 | 453684 |
| detection of arbovirus antibodies in avian sera by the complement fixation-inhibition test. | the complement fixation-inhibition (cfi) test was described for the detection of antibodies to arboviruses in bird sera. the cfi antibody present in bird sera inhibited the standard complement-fixation reaction of a reference complement-fixing antigen-antibody pair. using reference antigens (st. louis encephalitis, eastern equine encephalomyelitis, western equine encephalomyelitis, and yellow fever) prepared from infected mouse brains and reference antisera prepared in rabbits or horses, reprodu ... | 1979 | 464371 |
| interaction of alphaviruses with human peripheral leukocytes: in vitro replication of venezuelan equine encephalomyelitis virus in monocyte cultures. | human peripheral blood leukocytes (pbl) were examined for their ability to support growth of several group a arboviruses in vitro. cells were refractory to infection with eastern (eee) and western (wee) equine encephalitis viruses, whereas venezuelan equine encephalomyelitis (vee) virus was shown to infect and replicate to a substantially high titer. when pbl were fractionated into purified subpopulations, only the monocytes were susceptible to predictive vee virus infection. lymphocytes treated ... | 1979 | 468371 |
| prevalence of selected zoonotic diseases in vertebrates from haiti, 1972. | vertebrate animals collected in haiti in 1972 were tested for selected zoonotic diseases. no rabies virus or neutralizing (n) antibody was detected in bats (artibeus jamaicensis). however, n antibody against st. louis encephalitis, western equine encephalitis (wee), and eastern equine encephalitis were detected in resident species of birds and wee antibody in bats. no n antibody against venezuelan equine encephalitis was found. the possible introduction by migratory birds and local transmission ... | 1979 | 480524 |
| evaluation in humans of a new, inactivated vaccine for venezuelan equine encephalitis virus (c-84). | a new, formalin-inactivated vaccine for venezuelan equine encephalitis (vee) virus (c-84), prepared from an attenuated vaccine strain of virus (tc-83), was tested in humans. only occasional, mild, local and systemic reactions were noted in 28 volunteers; no meaningful changes in clinical laboratory values occurred. the vaccine augmented preexisting titers of serum neutralizing antibody to vee virus in seropositive recipients of tc-83 vaccine, and it induced high titers of neutralizing antibody i ... | 1979 | 528788 |
| seroepidemiologic studies in oaxaca, mexico. ii. survey for arbovirus antibody. | a serologic survey was conducted in south-western mexico to obtain information on human experience with arbovirus infections. sera were collected from two semitropical areas along the pacific coast of oaxaca state, two mountain areas above 1,700 meters and the interior valley at 1,500 meters. of the 610 sera tested for group a antibody, 4.9 per cent were positive in the hemagglutination-inhibition (hi) test to venezuelan (ve), 11 per cent to eastern, and none to western encephalitis viruses. in ... | 1979 | 539866 |
| western equine encephalitis with rapid onset of parkinsonism. | a patient with confirmed western equine encephalitis had the rapid onset of postencephalitic parkinsonian sequelae. this observation corroborates similar previous but rare reports. response to therapy with levodopa, dopa decarboxylase inhibitor, and trihexyphenidyl was dramatic. however, remission maintained for 12 months without medication suggests that the parkinsonism would have remitted spontaneously. in either case, this has not previously been reported with the western equine togavirus. | 1977 | 563006 |
| western encephalomyelitis in manitoba, 1975: the decision-making process. | | 1976 | 963657 |
| emergency measures and mosquito control operations during the 1975 western encephalomyelitis outbreak in manitoba. | | 1976 | 963658 |
| public information on western encephalomyelitis and emergency mosquito control in manitoba, 1975. | | 1976 | 963659 |
| environmental monitoring of insecticide applications during the emergency mosquito control operation in manitoba, 1975. | | 1976 | 963660 |
| assessment of the emergency mosquito control operation in manitoba, 1975. | | 1976 | 963661 |
| analysis of western encephalomyelitis surveillance and control programs in manitoba, 1975. | | 1976 | 963662 |
| [western encephalomyelitis in manitoba during 1975: summary and recommendations]. | | 1976 | 963663 |
| the arbovirus problem in canada. | | 1976 | 963664 |
| isolation and preliminary characterization of temperature-sensitive mutants of western equine encephalitis virus. | | 1978 | 622811 |
| selection of a strain of culex tarsalis highly resistant to infection following ingestion of western equine encephalomyelitis virus. | after prolonged selection, two hybrid strains of culex tarsalis were evolved that were highly resistant to infection following ingestion of western equine encephalomyelitis virus. these strains were greater than 25,000-fold more resistant than the most susceptible parental strain when fed on viremic chicks. resistance was associated with a mesenteronal barrier since both refractory and parental strains were equally susceptible to infection by intrathoracic inoculation. susceptibility was dominan ... | 1978 | 646024 |
| efficacy of trivalent inactivated encephalomyelitis virus vaccine in horses. | twenty-nine horses were vaccinated with a trivalent (venezuelan, eastern, and western) inactivated equine encephalomyelitis virus vaccine. the vaccine purchased for this study was the only one licensed and commercially available in may, 1975. plaque-neutralizing and hemagglutinin-inhibiting antibodies in response to each of the 3 equine encephalomyelitis viruses were determined after vaccination. horses had rising levels of plaque-neutralizing and hemagglutinin-inhibiting antibodies shortly afte ... | 1978 | 646197 |
| [insulin activity of blood serum of rabbits immunized with tick-borne encephalitis- and western-equine-encephalomyelitis viruses]. | administration of brain suspension of intact albino mice during the 1st, 3rd and 7th days after a single, double and prolonged (5-cycle) immunization of rabbits produced no significant changes in the functional condition of the insular apparatus. a single use in the capacity of an antigen of the brain tissue containing the tick-borne encephalitis or western horse encephalomyelitis viruses also led to no marked shifts in the blood serum insulin activity. in reimmunization with the virus-containin ... | 1978 | 665023 |
| rapid diagnosis of venezuelan equine encephalomyelitis by fluorescence microscopy. | goat venezuelan equine encephalomyelitis (vee) antiserum and normal serum were conjugated and evaluated for staining sensitivity and specificity. cross-staining with either eastern or western equine encephalomyelitis virus-infected cells did not occur. the baby hamster kidney (bhk-21) cell line when combined with highly specific vee conjugate detected 100 medium suckling mouse intracerebral lethal doses (suckling mouse ld-50/ic) of the 1b subtype of vee virus per milliliter of equine tissue susp ... | 1975 | 803352 |
| [interferonogenic and antiviral activity of the tobacco mosaic virus, tilorone and sodium nucleinate]. | production of endogenic interferon in animals in responce to administration of tobaco mozaic virus, tilorone and sodium nucleinate was shown. dependence of interferon production on the type of the inductor and the route of its administration was studied. absolute innocuiuty of the tobaco mozaic virus for monkeys (macaco-resus) and mice, as well as the absence of any side effects in humans treated with it perorally was shown. the tobaco mozaic virus, tilorone and sodium nucleinate used perorally ... | 1976 | 818948 |
| solid-phase radioimmunossay for rapid detection and identification of western equine encephalomyelitis virus. | a solid-phase radioimmunoassay technique was adapted for the rapid detection and identification of western equine encephalomyelitis virus in clinical specimens. | 1976 | 824305 |
| antibody studies in ponies vaccinated with venezuelan equine encephalomyelitis (strain tc-83) and other alphavirus vaccines. | serologic studies in 24 ponies indicated that prevaccination antibodies to venezuelan equine encephalomyelitis (vee) virus (strain tc-83) had no influence on hemagglutination-inhibition (hi) antibody stimulation by western equine encephalomyelitis (wee) or eastern equine encephalomyelits (eee)-wee vaccines. however, studies of the effects of vee neutralizing antibodies on neutralizing antibody stimulation by the heterologous alphavirus vaccines were inconclusive. the vee, wee, and eee antibody r ... | 1977 | 851275 |
| maturation defect of a temperature-sensitive mutant of western equine encephalitis virus. | the defective step of a temperature-sensitive mutant of western equine encephalitis virus, which synthesize viral rna but not mature virus at the restrictive temperature, was studied. cells infected with the mutant virus at the restrictive temperature synthesized the same intracellular viral rna as that in wild type infection. cells infected with the mutant at the restrictive temperature formed three proteins (e1, e2 and c) which migrated to positions identical with those of purified virions and ... | 1977 | 857772 |
| western equine encephalomyelitis in horses in the northern red river valley, 1975. | in mid-july, 1975, western equine encephalomyelitis (wee) virus was isolated from mosquitoes collected in flooded areas of eastern north dakota and western minnesota. inasmuch as clinical manifestations of wee are usually observed in horses before human cases of encephalitis are recognized, surveillance of equine disease was initiated. sixty-one practicing veterinarians from the are under surveillance reported 281 cases of wee in horses from june through september, with peak incidence in late ju ... | 1977 | 873843 |
| nucleolar fragmentation in cells infected with alphaviruses (39886). | | 1977 | 909877 |
| subcutaneous exposure of the richardson's ground squirrel (spermophilus richardsonii sabine) to western equine encephalomyelitis virus. | both adult and suckling richardson's ground squirrels (spermophilus richardsonii) were susceptible to subcutaneous exposure with western equine encephalomyelitis (wee) virus, but the virus was more virulent for sucklings than adults. in sucklings, the incubation period was from 4 to 5 days, followed by apparent signs of central nervous system (cns) involvement. death occurred 10 to 13 days postexposure. in adults, infections were inapparent or acute with typical signs of cns involvement similar ... | 1976 | 933316 |
| preparation and testing of vaccines prepared from the envelopes of venezuelan, eastern, and western equine encephalomyelitis viruses. | envelope components were separated from venezuelan, eastern, and western equine encephalomyelitis viruses after treatment of the virions with detergent. vaccines prepared from the envelope component were capable of stimulating mice to produce humoral antibodies. protective efficacy studies were performed using mono-, di-, and trivalent vaccine combinations. these elicited varying degrees of homologous protection, and eastern and venezuelan equine encephalomyelitis envelope products appeared to c ... | 1976 | 942635 |
| arbovirus encephalitis-diagnostic considerations. | | 1976 | 956673 |
| virulence heterogeneity of a predominantly avirulent western equine encephalitis virus population. | selective removal of small plaque (sp) western equine encephalitis (wee) virus from a population heterogeneous with respect to virulence and plaque morphology permitted direct detection of a small sub-population of virulent large plaque (lp) wee virus. selective removal of sp-wee virus was achieved by intracardiac (i.c.a.) inoculation of hamsters; plasma obtained 60 min after inoculation was proportionately enriched for lp-wee virus since only the sp-wee virus was cleared. by this method, the pr ... | 1976 | 956785 |
| sentinel flock monitoring procedures for western encephalomyelitis in manitoba-1975. | | 1976 | 963653 |
| equine epizootic of western encephalomyelitis in manitoba-1975. | | 1976 | 963654 |
| an epidemic of western encephalomyelitis in humans-manitoba, 1975. | | 1976 | 963655 |
| weather conditions affecting mosquito populations in southern manitoba during 1975. | | 1976 | 963656 |
| diffusible viral interference during arbovirus plaque formation. | a radially diffusing zone of nonspecific interference was observed surrounding plaques of western equine encephalitis virus. the increase in diameters of the zones of interference were linear and more rapid than increases in plaque diameters. these observations raise the possibility that viral-induced interference could account for the diminished growth of western equine encephalitis virus plaques with time or even the initial formation of plaques. in addition, this system could be used as a mod ... | 1976 | 971948 |
| inhibition of cellular dna synthesis in hamster kidney cells infected with western equine encephalitis virus. | infection of bhk cells with western equine encephalitis (wee) virus resulted in rapid inhibition of cellular dna synthesis. the rate of inhibition of dna synthesis depended on the multiplicity of infection, and was closely related to virus replication. cellular dna synthesis was not inhibited in infected bhk cells that had been irradiated with ultraviolet radiation. these results indicated that a functional viral genome was required for the inhibition of dna synthesis by wee virus. the sharp dec ... | 1976 | 973797 |
| infectivity of a multiploid-forming mutant of western equine encephalitis virus. | | 1976 | 978836 |
| a statistical model of the dynamics of a mosquito vector (culex tarsalis) population. | a model of the dynamics of a mosquito culex tarsalis is derived that includes the life states through which the mosquito proceeds. transition probabilities from one state (egg, larva, pupa and adult) to another are derived and they depend on the duration of stay and mortality in each state. a formula is derived for the expected number of mosquitoes alive at any time during the spring or summer. this formula depends on the number of eggs oviposited and the transition probabilities. data are used ... | 1976 | 953134 |
| intranasal exposure of the richardson's ground squirrel to western equine encephalomyelitis virus. | adult richardson's ground squirrels were infected with western equine encephalomyelitis virus by intranasal instillation. mortality followed the instillation of a minimum threshold of 4.7 logs of virus while infection was produced by a dosage of 2.3 logs. the incubation period was from four to seven days, being preceded by a viremic phase. signs were depression, ataxia and paralysis of the limbs. highest titres of virus were recovered from the brain and histopathological changes involving the ce ... | 1978 | 667706 |
| venezuelan equine encephalomyelitis vaccine (strain tc-83): a field study. | in 1971, more than 370 horses in south texas were studied with respect to their clinical, virologic, and neutralizing antibody responses to vaccination with venezuelan equine encephalomyelitis (vee) strain tc-83. this study confirms reported findings that the vaccine used in the 1971 epizootic in the lower rio grande valley of texas was safe and efficacious. vaccinal virus viremia titers were generally below the postulated infection threshold of epizootic vectors. in general, reactions to the va ... | 1978 | 717877 |
| delayed multiplication of semliki forest virus in organ cultures of muscle from vaccinated mice. | local immunity against the homologous virus was detected from the first until the third day of incubation in organ cultures of muscle from mice previously vaccinated with semliki forest virus. | 1976 | 1015007 |
| amount of western equine encephalitis virus inoculated by transmitting culex tarsalis mosquitoes. | the amount of western equine encephalitis virus inoculated by infected culex tarsalis mosquitoes is highly variable between individual mosquitoes. the majority (68 per cent) inoculate less than 100 intracerebral three-week-old mouse ld50 at time of feeding and the quanity appears unrelated to temperature or length of incubation following initial infection. | 1976 | 1025639 |
| [immune mechanisms of resistance in mice to the western equine encephalomyelitis virus]. | using the immunogenetic method and method of immunomodification of outbred animals, it was established that immune response of humoral or cell-mediated type to wee virus antigens did not play any important role in the survival of intact mice infected with wee virus. under such conditions, it is inexpedient to select immune response modulators. the immune response of predominantly cell-mediated type is a determining factor of resistance to wee virus in mice after immunization started 7 days befor ... | 1990 | 1964514 |
| evaluation of the epidemic potential of western equine encephalitis virus in the northeastern united states. | | 1976 | 1035448 |
| effect of cordycepin on the replication of western equine encephalitis virus. | cordycepin (3'-deoxyadenosine) inhibited viral rna synthesis in the replication of western equine encephalitis virus, thereby causing a reduction of virus production. the rate of inhibition of viral rna synthesis was dependent on drug concentration and the period of treatment with the drug. these results suggest that the virus rna synthesizing system is sensitive to the drug. | 1976 | 1087872 |
| an assessment of the biological capacity of a sacramento valley population of aedes melanimon to vector arboviruses. | daily survivorship, duration of the gonotrophic cycle, absolute abundance and season-long relative abundance were estimated for aedes melanimon in the sacramento valley of california in 1987 and 1988 using mark-release-recapture (mrr) techniques and by monitoring changes in the abundance and parity rate of the native population. one objective of these studies was to determine the extent to which a. melanimon was biologically capable of serving as a horizontal arbovirus vector. daily survivorship ... | 1991 | 2042703 |
| epidemic venezuelan equine encephalitis in north america in 1971: vertebrate field studies. | epidemic venezuelan equine encephalitis in north america in 1971: vertebrate field studies. am j epidemiol 101:36-50, 1975.-in june 1971, epidemic venezuelan equine encephalitis (vee) invaded the lower rio grande valley in south texas. the boca chica area of cameron county was selected as a study site to investigate vertebrate involvement in the natural cycle of epidemic vee on the basis of considerable evidence of vee virus activity there in equines, humans, and mosquito vectors. only one vee v ... | 1975 | 1119481 |
| natural infections of richardson's ground squirrels with western equine encephalomyelitis virus, saskatchewan, canada, 1964-1973. | a survey (1964-1973) was conducted on naturally occurring western equine encephalomyelitis (wee) virus infections of richardson's ground squirrels (rgs) in agricultural areas of saskatchewan. the survey included both serology and virus isolation attempts on live-trapped wild squirrels. throughout the study, seropostive squirrels were found in the known enzootic regions of the province each summer. the infections rate was high (11.6% of 250) in the epidemic year of 1965 and low (less than 2% o ... | 1975 | 1148947 |
| arbovirus surveillance in florida: wild vertebrate studies 1965-1974. | wildlife species from 38 of florida's 67 counties were surveyed over a 10 year period for the presence of antibody to the five major arboviruses circulating in the state. the routine screening of 7891 sera from wild birds and mammals via the hemagglutination-inhibition (h1) test with selected reactors subjected to serum neutralization testing has 1) provided information regarding geographic distribution and seasonality of circulation of these viruses 2) identified enzootic foci of infection and ... | 1975 | 1152173 |
| environmental modification of western equine encephalomyelitis infection in the snowshoe hare (lepus americanus). | the snowshoe hare (lepus americanus) could be infected with western equine encephalomyelitis (wee) virus and produce a viremia. furthermore, viremia in hares exposed to variable climatic conditions differed significantly from viremias seen in the control animals held at constant temperatures. the viremia duration and titer were increased in animals subjected to fluctuating temperature and humidity. the time of onset of viremia was accelerated. antibody response also increased in animals exposed ... | 1975 | 1168174 |
| morphological and physical properties of a multiploid-forming mutant of western equine encephalitis virus. | morphological and physical properties of a multiploid-forming mutant of western equine encephalitis virus were studied. electron micrographs of the infected cells showed that most of mutant virions bud from the plasma or vacuolar membrane as a multiploid particle containing a various number of nucleocapsids enclosed with a defined common envelope. the mutant virions contained three polypeptides which migrated to the position identical with those of wild type on discontinuous acrylamide gels. cel ... | 1975 | 1170339 |
| neutralization kinetics of western equine encephalitis virus by antibody fragments. | | 1975 | 1184110 |
| effect of the anesthetizing agent triethylamine on western equine encephalomyelitis and st. louis encephalitis viral titers in mosquitoes (diptera: culicidae). | triethylamine (tea) is a chemical compound that provides an effective means to anesthetize mosquitoes. the mosquitoes remain alive but are incapacitated for several hours; they do not recover following treatment. there was no effect on the titers of infectious virus recovered from western equine encephalomyelitis or st. louis encephalitis virus-infected culex tarsalis coquillett and aedes dorsalis (meigen) that were anesthetized with tea prior to storage at -70 degrees c. furthermore, tea had no ... | 1990 | 2280383 |
| a field study of persistence of antibodies in california horses vaccinated against western, eastern, and venezuelan equine encephalomyelitis. | as a result of the continuing threat of venezuelan equine encephalomyelitis (vee), a study was made to determine if revaccination against vee (tc-83 vaccine) was feasible and if revaccination could be incorporated into other routine vaccination practices. of the horses given annual vaccination with bivalent western equine encephalomyelitis (wee) and eastern equine encephalomyelitis (eee) vaccine, 57% retained detectable serum-neutralizing (sn) antiboyd titers for vee 18 months after the initial ... | 1975 | 1190598 |
| pathogenicity of an attenuated, temperature-sensitive mutant of western equine encephalitis virus induced by a chemical mutagen. | to know the pathogenicity of the chemically induced, temperature-sensitive (ts) mutant of western equine encephalitis virus, designated tsng39, the lethality for mice injected with tsng39, virus yield, interferon production, and histological changes in the brains of these mice were examined in parallel with those of mice inoculated with the parent strain (ps). all of the mice injected intracranially with ps died within 3.5 days after injection irrespective of the inoculum size of virus, whereas ... | 1975 | 1193717 |
| trivittatus virus infections in wild mammals and sentinel rabbits in central iowa. | a serological survey was conducted in iowa to determine the prevalence rate of california group virus antibodies in sera of several vertebrate species. serum specimens were assayed for infectivity-neutralizing antibody in a microneutralization system with baby hamster kidney cell culture. of 77 sera assayed, 21 (27%) neutralized trivittatus (tvt) virus infectivity. the antibody prevalence rate was highest for eastern cottontail rabbits inasmuch as 46% (10/22) of the serum specimens form this spe ... | 1975 | 1200251 |