Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| [junin virus activity in humans and rodents of non-endemic areas of the province of buenos aires]. | 1985 | 3020341 | |
| [effect of cyclophosphamide on the development of infection in calomys musculinus with junin virus]. | 1985 | 3022105 | |
| [effect of cyclophosphamide on the development of infection in calomys musculinus with junin virus]. | 1985 | 3022105 | |
| [mononuclear phagocytes in the resistance of mice to extraneural infection with junin virus]. | 1985 | 3023788 | |
| [modification of the course of junin virus infection in guinea pigs by administration of immune sera]. | 1985 | 3023791 | |
| [modification of the course of junin virus infection in guinea pigs by administration of immune sera]. | 1985 | 3023791 | |
| effect of immunosuppression on experimental argentine hemorrhagic fever in guinea pigs. | immunosuppression with cyclosporin a or cyclophosphamide had no apparent effect on the disease course of guinea pigs infected with a virulent strain of junin virus. immunosuppression of guinea pigs infected with an attenuated strain of junin virus led to fulminating argentine hemorrhagic fever. all immunosuppressed infected animals died. virus distribution patterns in target organs, as determined by plaque assay and fluorescent antibody procedures, were similar to those from non-immunosuppressed ... | 1985 | 2981364 |
| effect of immunosuppression on experimental argentine hemorrhagic fever in guinea pigs. | immunosuppression with cyclosporin a or cyclophosphamide had no apparent effect on the disease course of guinea pigs infected with a virulent strain of junin virus. immunosuppression of guinea pigs infected with an attenuated strain of junin virus led to fulminating argentine hemorrhagic fever. all immunosuppressed infected animals died. virus distribution patterns in target organs, as determined by plaque assay and fluorescent antibody procedures, were similar to those from non-immunosuppressed ... | 1985 | 2981364 |
| attenuated junin virus infection in callithrix jacchus. | twenty marmosets, male callithrix jacchus, were used during this study. fifteen of the marmosets were inoculated with 5,000 tcid50 of the attenuated xjc13 strain of junin virus by intramuscular route and five were left as uninoculated controls. animals were observed for a 420-day period. in order to carry out virologic, hematologic, serologic, and histologic studies the animals were bled and/or killed at different days post infection(pi). results obtained showed that the attenuated strain produc ... | 1985 | 2981980 |
| attenuated junin virus infection in callithrix jacchus. | twenty marmosets, male callithrix jacchus, were used during this study. fifteen of the marmosets were inoculated with 5,000 tcid50 of the attenuated xjc13 strain of junin virus by intramuscular route and five were left as uninoculated controls. animals were observed for a 420-day period. in order to carry out virologic, hematologic, serologic, and histologic studies the animals were bled and/or killed at different days post infection(pi). results obtained showed that the attenuated strain produc ... | 1985 | 2981980 |
| effect of staggered cyclophosphamide-immunosuppression on resistance to experimental junin virus infection. | otherwise resistant adult mice were rendered susceptible to intracerebral junin virus (jv) infection only when a staggered cyclophosphamide (cy) schedule was used. forty-five-day old balb/c mice, intracerebrally jv-infected and immunosuppressed with four 50 mg/kg body weight cy doses at days -1, +1, +4, +6 (day 0: viral infection) developed a lethal disease (86.6 per cent mortality) with high cns viral titers and brain lesions. neutralizing antibodies were absent throughout, while immunofluoresc ... | 1985 | 2982356 |
| interactions of junin and tacaribe viruses during mixed infections. | the interaction between junin virus (jv) and tacaribe virus (tacv) during mixed infections of rk13 cells was examined. the effects of a prior infection with jv upon tacv replication depended on the time between the two inoculations. simultaneous infection of rk13 cells with tacv and jv did not alter the plaquing efficiency of tacv; but if there was a 1- to 24-hour delay between jv preinfection and tacv superinfection, a variable increase of tacv replication was observed. the enhancement of tacv ... | 1985 | 2982755 |
| infection of pregnant guinea pigs with attenuated junin virus strains. | the effect of the attenuated xjc13 and xj0 strains of junin virus (jv) was studied in guinea pigs infected before and during pregnancy. the 58% mortality rate in animals infected during gestation and the 16.7% mortality rate in chronically infected animals were attributed to a viral effect. an abortion rate of 33% occurred in animals infected before the 7th week of gestation. regardless of the time of infection, jv was isolated from central nervous system tissue, placentas, and fetuses of animal ... | 1985 | 2982762 |
| infection of pregnant guinea pigs with attenuated junin virus strains. | the effect of the attenuated xjc13 and xj0 strains of junin virus (jv) was studied in guinea pigs infected before and during pregnancy. the 58% mortality rate in animals infected during gestation and the 16.7% mortality rate in chronically infected animals were attributed to a viral effect. an abortion rate of 33% occurred in animals infected before the 7th week of gestation. regardless of the time of infection, jv was isolated from central nervous system tissue, placentas, and fetuses of animal ... | 1985 | 2982762 |
| neurotropism of a high-passage xj strain of junín virus. | guinea pig infection with a highly passaged xj prototype strain of junín virus by the intramuscular route (im) was carried out in order to study viral tropism modification in this host. the neurotropism of this strain was demonstrated by viral isolation, meningitis, and by the presence of junín antigens as shown by immunofluorescence. these events, not previously observed with the same lower-passaged strain, revealed the appearance of neurotropism after multiple passages in guinea pigs. | 1985 | 2983010 |
| neurotropism of a high-passage xj strain of junín virus. | guinea pig infection with a highly passaged xj prototype strain of junín virus by the intramuscular route (im) was carried out in order to study viral tropism modification in this host. the neurotropism of this strain was demonstrated by viral isolation, meningitis, and by the presence of junín antigens as shown by immunofluorescence. these events, not previously observed with the same lower-passaged strain, revealed the appearance of neurotropism after multiple passages in guinea pigs. | 1985 | 2983010 |
| pathogenesis of attenuated junin virus in the guinea pig model. | the purpose of this work was to elucidate the pathogenesis of attenuated junin virus (jv) strains in the guinea pig model. three groups of guinea pigs were infected by the im route with 10(3) pfu of the xjc13 and xjo-attenuated strains or with the xj pathogenic strain of jv, respectively. viremia was studied at 3, 5, 7, 9, 12, and 14 days postinfection (pi) (a) in serum samples of all animals and in washed cells from xjc13-infected guinea pigs by conventional techniques and (b) in whole blood sa ... | 1985 | 2983013 |
| pathogenesis of attenuated junin virus in the guinea pig model. | the purpose of this work was to elucidate the pathogenesis of attenuated junin virus (jv) strains in the guinea pig model. three groups of guinea pigs were infected by the im route with 10(3) pfu of the xjc13 and xjo-attenuated strains or with the xj pathogenic strain of jv, respectively. viremia was studied at 3, 5, 7, 9, 12, and 14 days postinfection (pi) (a) in serum samples of all animals and in washed cells from xjc13-infected guinea pigs by conventional techniques and (b) in whole blood sa ... | 1985 | 2983013 |
| mrc-5 cells, a model for junín virus persistent infection. | persistent infection of mrc-5 cells was established following inoculation with attenuated junín virus (jv). in the acute phase of the infection both the pathogenic xj and the attenuated xj0 and xjc13 strains showed severe c.p.e. and free viral titres reached 10(5) p.f.u./ml. recovery and establishment of persistently infected mrc-5 sublines (mrc-5pi) proved a very common event and seemed to be independent of viral strain, m.o.i. employed or virus passage history. these mrc-5pi sublines released ... | 1985 | 2987401 |
| congenital guinea pig infection with attenuated junin virus strains. | guinea pigs born from mothers infected before or during pregnancy with 10(3) pfu of the attenuated xjc13 or xj0 strains of junin virus (jv) by the intramuscular route showed 31.5% mortality that was not attributable to the mothers' clinical condition or to lack of care. there was a slight drop in mortality rate when the mothers were infected at the beginning or end of their gestation period. jv isolation from the 9 offspring killed from 1 to 125 days of age proved that virus transmitted transpla ... | 1985 | 2989214 |
| congenital guinea pig infection with attenuated junin virus strains. | guinea pigs born from mothers infected before or during pregnancy with 10(3) pfu of the attenuated xjc13 or xj0 strains of junin virus (jv) by the intramuscular route showed 31.5% mortality that was not attributable to the mothers' clinical condition or to lack of care. there was a slight drop in mortality rate when the mothers were infected at the beginning or end of their gestation period. jv isolation from the 9 offspring killed from 1 to 125 days of age proved that virus transmitted transpla ... | 1985 | 2989214 |
| astrocyte differentiation induced by junín virus in rat brain cell cultures. | morphological and immunocytochemical differentiation was observed in astroglial cell cultures of the rat infected with junín virus. from days 3 to 6 postinoculation (p.i.), gfap immunostaining was observed in both the perikaryon and processes of maturated astrocytes, whereas it was limited to the perikaryon in less differentiated cells. the rather slow spontaneous differentiation usually occurring in astroglial cell cultures was seen to be accelerated by viral infection, mimicking the astrocytic ... | 1985 | 2990148 |
| influence of cellular functions on the evolution of persistent infections with junin virus. | vero cell cultures persistently infected with junin virus and subjected to different cultural conditions were established. the production of infectious plaque-forming virus, ts mutants and interfering viral particles was determined at different times during 110 days after infection. carrier cultures maintained in stationary conditions continuously released pfu while proliferating persistent cultures exhibited a cyclical pattern which tends to a rapid pfu disappearance. concomitantly, in stationa ... | 1985 | 2998303 |
| junin virus-induced chromosomal aberrations in the guinea pig. synergism between the attenuated strain xj-clone 3 and caffeine. | the frequency of chromosomal aberrations in bone marrow cells of guinea pigs inoculated with the pathogenic xj strain of junin virus increased significantly at 6, 9, and 11 days postinoculation (p.i.). animals inoculated with the attenuated xj-clone 3 strain only showed significant increments of achromatic lesions (gaps) at 9 days p.i. guinea pigs inoculated with the xj-clone 3 strain and then treated with two doses of caffeine 24 and 12 h before killing at 9 days p.i. exhibited a significant in ... | 1985 | 3000979 |
| junin virus-induced chromosomal aberrations in the guinea pig. synergism between the attenuated strain xj-clone 3 and caffeine. | the frequency of chromosomal aberrations in bone marrow cells of guinea pigs inoculated with the pathogenic xj strain of junin virus increased significantly at 6, 9, and 11 days postinoculation (p.i.). animals inoculated with the attenuated xj-clone 3 strain only showed significant increments of achromatic lesions (gaps) at 9 days p.i. guinea pigs inoculated with the xj-clone 3 strain and then treated with two doses of caffeine 24 and 12 h before killing at 9 days p.i. exhibited a significant in ... | 1985 | 3000979 |
| [role of macrophages in the dissemination of the junin virus in the rat]. | the 2-day-old rat is known to be susceptible to infection by ip route with the xj strain of junin virus but resists inoculation with xjc13 strain (85% vs 15% mortality). in order to determine whether peritoneal macrophages play a role in modulating the course of infection, viral replication in adherent peritoneal cells infected with either strain was studied. xj was found to replicate 30-fold as regards xjc13 at day 3 pi. besides, silica blockage of peritoneal macrophages was also evaluated. fol ... | 1985 | 2825238 |
| [association of the infection of the thymus and bone marrow with the establishment of persistent infection with junin virus in 2 genera of rodents]. | junin virus infection of immune system organs was correlated with persistence establishment in the mouse and rat. rockland mice under 24 or at 72 and 120 h of age received 10(4) pfu of junin virus xj strain by ic route. separately, two groups of mice under 24 h old were infected with the same dose of xj or xjcl3 strain by the same route respectively. results showed that higher thymus virus titer correlated with greater survival. in turn, the former also seemed to correlate with decreasing age at ... | 1985 | 2829274 |
| attenuation parameters for junin virus in the newborn rat. | to characterize a virus strain as attenuated, both biologic and biochemical criteria are necessary. in the case of junin virus, the 2-day-old rat has proved to be a biologic attenuation marker as regards mortality. here we studied the behaviour of the prototype xj vs the attenuated xjc13 strain inoculated by either ic or ip route to determine differential hematologic and splenic parameters. humoral immune response against srbc was also investigated. by either route xj caused significant leucocyt ... | 1985 | 2829275 |
| [isolation of junin virus from blood and peripheral lymphocytes of infected calomys musculinus]. | neonatal calomys musculinus experimental infection with junín virus (jv) xjcl3 strain causes either death or a persistent infection in the major part of surviving animals. jv can be isolated from peritoneal macrophages early during infection, and from brain and salivary glands during the chronic state of disease. it was of interest to investigate the appearance of virus in blood of infected animals. for this purpose, we decided to study the development of viremia in inoculated cricetids. a high ... | 1985 | 2829277 |
| [isolation of junin virus from blood and peripheral lymphocytes of infected calomys musculinus]. | neonatal calomys musculinus experimental infection with junín virus (jv) xjcl3 strain causes either death or a persistent infection in the major part of surviving animals. jv can be isolated from peritoneal macrophages early during infection, and from brain and salivary glands during the chronic state of disease. it was of interest to investigate the appearance of virus in blood of infected animals. for this purpose, we decided to study the development of viremia in inoculated cricetids. a high ... | 1985 | 2829277 |
| properties and characterization of monoclonal antibodies to tacaribe virus. | monoclonal antibodies prepared against tacaribe and junin viruses have been used to define further the serological relationships between arenaviruses of the tacaribe complex. a close relationship was found between these two viruses and the heterologous amapari and machupo viruses, with pichinde virus and parana virus being more distantly related. among the antibodies specific for tacaribe virus, five were found to react with viral antigens at the surface of infected cells and to neutralize virus ... | 1985 | 2410550 |
| early protection to junín virus of guinea pig with an attenuated junín virus strain. | inoculation of guinea pigs with attenuated xjo junín virus (jv) strain confers protection against challenge with pathogenic xj-jv strain starting as early as 3 days post infection (p.i.). the protection increased continuously up to 100% by 30 days p.i. neither stimulation of non-specific cell mediated mechanisms by previous bcg sensitization nor circulating interferon (ifn) seemed essential for such protection. the early detection of the virus in guinea pig organs considered the site of primary ... | 1985 | 2413752 |
| early protection to junín virus of guinea pig with an attenuated junín virus strain. | inoculation of guinea pigs with attenuated xjo junín virus (jv) strain confers protection against challenge with pathogenic xj-jv strain starting as early as 3 days post infection (p.i.). the protection increased continuously up to 100% by 30 days p.i. neither stimulation of non-specific cell mediated mechanisms by previous bcg sensitization nor circulating interferon (ifn) seemed essential for such protection. the early detection of the virus in guinea pig organs considered the site of primary ... | 1985 | 2413752 |
| splenic dendritic cells and junin virus. | 1986 | 2425232 | |
| [susceptibility of 11-day-old mice to infection with the junin virus grown in different hosts]. | twelve clones derived from a stock of junin virus grown in baby mouse brain were isolated in vero cells. some properties of those viral clones were determined and compared with parental virus in order to ascertain the degree of heterogenicity of the original population. no differences were observed among clones and parental virus when the degree of thermolability was measured by heating them at 50 degrees c for 30 min. (table 1). similarly no ts phenotype character was present among all viral is ... | 1986 | 2825239 |
| [protection conferred by a hyperimmune serum and its fractions on rats infected with the junin virus]. | suckling rats infected by ic route with 10(3)ld50 of the xjc13 strain of jv were passively immunized with homologous hyperimmune serum (his). animals treated at 2 days pi with his showed a significant increase in survival vs. non-treated infected controls (82% vs 5%). however, at 4 days pi, transfer failed to modify survival. by means of deae sephadex a25 column chromatography, the presence of neutralizing immunoglobulin closely correlated with protective antibodies, but were not restricted to t ... | 1986 | 2825240 |
| antiviral effect of ribavirin on junin virus replication in vitro. | the effect of ribavirin (1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide) on the replication in vitro of junin virus, the causative agent of argentine hemorrhagic fever (ahf), was examined. a concentration as low as 3.12 micrograms/ml of the drug inhibited the cytopathic effect observed five days post-infection (pi) on vero cells. on the other hand, a concentration of 25 micrograms/ml reduced the virus yield and specific antigen formation to undetectable levels. this same concentration of ri ... | 1986 | 2825242 |
| brain inflammatory exudate in junin virus-infected rats: its characterization by the immunoperoxidase (pap) technique. | morphologic changes in cyclophosphamide (cy)-suppressed vs. control non-suppressed new-born rats infected i.c. with xjc13 strain of junin virus were compared and the cells involved in cns lesions were identified by the pap technique. fifty per cent of the control rats exhibited widespread cerebral necrosis vs. only 15% of the immunosuppressed animals. the first cells to reach junin virus-infected cns in controls were t lymphocytes, which destroyed viral antigen-laden target neurons and astrocyte ... | 1986 | 3005359 |
| administration of antithymocyte serum modifies the response of calomys musculinus to junin virus infection. | approximately 80% of calomys musculinus inoculated with an attenuated strain of junin virus (jv) developed a lethal encephalitis. antithymocyte serum, a potent suppressor of t-cell-mediated immunity, was studied for its effect on jv pathogenicity. early administration of an anti-c. musculinus thymocyte serum (acts) to neonatal animals significantly diminished clinical disease and death and abrogated brain damage, which is usually associated with viral presence in the brain. late acts administrat ... | 1986 | 3009353 |
| administration of antithymocyte serum modifies the response of calomys musculinus to junin virus infection. | approximately 80% of calomys musculinus inoculated with an attenuated strain of junin virus (jv) developed a lethal encephalitis. antithymocyte serum, a potent suppressor of t-cell-mediated immunity, was studied for its effect on jv pathogenicity. early administration of an anti-c. musculinus thymocyte serum (acts) to neonatal animals significantly diminished clinical disease and death and abrogated brain damage, which is usually associated with viral presence in the brain. late acts administrat ... | 1986 | 3009353 |
| role of calomys musculinus peritoneal macrophages in age-related resistance to junin virus infection. | in nature, the cricetid calomys musculinus is the principal host of junin virus, the etiological agent of argentine hemorrhagic fever. in the experimental infection, adult c. musculinus survived whereas newborns died after intraperitoneal inoculation with the xj.cl3 strain of junin virus. the role of peritoneal macrophages in this age-related resistance was studied. junin virus multiplied in cultivated macrophages from either neonatal or adult animals and, therefore, it was not possible to corre ... | 1986 | 3009700 |
| role of calomys musculinus peritoneal macrophages in age-related resistance to junin virus infection. | in nature, the cricetid calomys musculinus is the principal host of junin virus, the etiological agent of argentine hemorrhagic fever. in the experimental infection, adult c. musculinus survived whereas newborns died after intraperitoneal inoculation with the xj.cl3 strain of junin virus. the role of peritoneal macrophages in this age-related resistance was studied. junin virus multiplied in cultivated macrophages from either neonatal or adult animals and, therefore, it was not possible to corre ... | 1986 | 3009700 |
| experimental infection of akodon molinae (rodentia, cricetidae) with junín virus. | experimental infection with the xj-clone 3 strain of junín virus in laboratory bred akodon molinae, a cricetid rodent inhabiting the borders of endemic argentine hemorrhagic fever areas, was studied. suckling animals inoculated intracerebrally proved sensitive and became chronically infected. sixty percent of the rodents showed neurologic involvement, with mortality reaching 60%. virus was recovered from the brain at 7, 15, 21, 37, and 57 days postinfection (pi). by immunofluorescence (if), vira ... | 1986 | 3009705 |
| experimental infection of akodon molinae (rodentia, cricetidae) with junín virus. | experimental infection with the xj-clone 3 strain of junín virus in laboratory bred akodon molinae, a cricetid rodent inhabiting the borders of endemic argentine hemorrhagic fever areas, was studied. suckling animals inoculated intracerebrally proved sensitive and became chronically infected. sixty percent of the rodents showed neurologic involvement, with mortality reaching 60%. virus was recovered from the brain at 7, 15, 21, 37, and 57 days postinfection (pi). by immunofluorescence (if), vira ... | 1986 | 3009705 |
| junin virus access to cns by extraneural rat inoculation. | this study was carried out to determine the pathways along which two strains of junin virus (jv), the pathogenic xjv and the attenuated xjc13v, reach the cns following ip inoculation of 2-day-old rats. a sequential study of infectivity and antigen distribution in peritoneal macrophages, spleen, and brain was performed. mortality was 85% with the former strain, but only 15% with the latter. at 4-7 days pi, xjv-infected animals had viral antigen in 10% of peritoneal macrophages. viremia and spleen ... | 1986 | 3009706 |
| effect of ribavirin and tributylribavirin on argentine hemorrhagic fever (junin virus) in guinea pigs. | subcutaneous injections of ribavirin into guinea pigs infected intraperitoneally or intracerebrally with junin virus significantly increased the mean time to death but did not enhance survival of the animals. we found similar results with tributylribavirin. virus replication was delayed, but not prevented, in ribavirin-treated infected guinea pigs. the animals usually died with high virus titers in their brains and frequently were paralyzed. | 1986 | 3013087 |
| effect of ribavirin and tributylribavirin on argentine hemorrhagic fever (junin virus) in guinea pigs. | subcutaneous injections of ribavirin into guinea pigs infected intraperitoneally or intracerebrally with junin virus significantly increased the mean time to death but did not enhance survival of the animals. we found similar results with tributylribavirin. virus replication was delayed, but not prevented, in ribavirin-treated infected guinea pigs. the animals usually died with high virus titers in their brains and frequently were paralyzed. | 1986 | 3013087 |
| junin virus isolation from lympho-mononuclear cells of patients with argentine hemorrhagic fever. | detection of viremia was attempted by three different methods in 30 cases of argentine hemorrhagic fever (ahf). cocultivation of peripheral blood mononuclear cells (pbmc) with vero cell monolayers was the most sensitive, detecting junin virus (jv) in 96% of the cases. inoculation of whole blood into suckling mice and on vero cells rendered 53 and 46% of positive isolations, respectively. the results presented suggest that pbmc are infected with jv during the acute period of ahf. jv was isolated ... | 1986 | 3013799 |
| relationship between junin virus infection of thymus and the establishment of persistence in rodents. | 1986 | 3014287 | |
| heterogeneity of junin virus strains. | 1986 | 3014289 | |
| damage of human polymorphonuclear leukocytes by junin virus. | 1986 | 3014291 | |
| effect of ribavirin and immune serum on junin virus-infected primates. | 1986 | 3014292 | |
| photodynamic inactivation of junin virus. | 1986 | 3014294 | |
| antigenic variants of junín virus isolated from infected calomys musculinus. brief report. | junín virus establishes a long-term persistent infection in its natural host, calomys musculinus. virus recovered from blood of infected animals from 14 to 61 days p.i. behaved antigenically distinct to parental virus, as shown by cross neutralization assays. the emergence of antigenic viral variants occurs during both the acute and persistent state of infection. | 1986 | 3015087 |
| antigenic variants of junín virus isolated from infected calomys musculinus. brief report. | junín virus establishes a long-term persistent infection in its natural host, calomys musculinus. virus recovered from blood of infected animals from 14 to 61 days p.i. behaved antigenically distinct to parental virus, as shown by cross neutralization assays. the emergence of antigenic viral variants occurs during both the acute and persistent state of infection. | 1986 | 3015087 |
| macrophage maturity and modulation of response to junín virus in infected rats. | replication of junín virus in peritoneal macrophages from newborn rats was greater for prototype strain xj than for strain xjc13, whereas in cells from adult animals viral multiplication proved minimal. transfer of peritoneal adherent cells from normal adult to strain xj-infected newborn rats lowered mortality significantly. silica blockade of macrophages protected two-day-old strain xj-infected animals and depressed brain titers of virus significantly, whereas treatment had no effect on strain ... | 1986 | 3016114 |
| partial characterization of two temperature-sensitive mutants of junin virus. | two temperature sensitive (ts) mutants of junin virus, a member of arenaviridae, have been partially characterized. both mutants, named ts-32 and ts-40, had a relative plating efficiency 40 degrees c/34 degrees c lower than 10(-3) an exhibited a leak yield below 10(-4). standard growth curves showed that at 34 degrees c the viral mutants multiplied slower than wt virus and at high multiplicity did not display autointerference. no differences in thermolability were observed between wt and ts muta ... | 1986 | 3018452 |
| chronic neurologic disease in junín virus-infected rats. | the purpose of this study was to determine whether junín virus persistence in cns of rats was capable of inducing late neurologic disease. following intracerebral inoculation of newborn animals with xj strain, three distinct stages could be discerned: an early phase of acute disease, up to 30 days pi, with 5% mortality; an intermediate one, extending to 280 days pi, without clinical signs but with evident viral persistence; and a final period of chronic illness, featuring clinical neurologic syn ... | 1986 | 3020168 |
| cytolysis of junin infected target cells by immune guinea pig spleen cells. | spleen cells from guinea pigs infected with an attenuated strain of junin virus (the causative agent of argentine hemorrhagic fever) specifically lysed virus-infected syngeneic target cells in vitro. this activity was detected as early as 6 days after infection, reached a maximum on days 10-13, and persisted at lower levels, at least through day 30. monoclonal antibody to guinea pig t cells had no effect on the activity. after b or t cell enrichment techniques, the cytolysis was found with the b ... | 1986 | 2854602 |
| cytolysis of junin infected target cells by immune guinea pig spleen cells. | spleen cells from guinea pigs infected with an attenuated strain of junin virus (the causative agent of argentine hemorrhagic fever) specifically lysed virus-infected syngeneic target cells in vitro. this activity was detected as early as 6 days after infection, reached a maximum on days 10-13, and persisted at lower levels, at least through day 30. monoclonal antibody to guinea pig t cells had no effect on the activity. after b or t cell enrichment techniques, the cytolysis was found with the b ... | 1986 | 2854602 |
| geographic patterns of allele frequencies in calomys musculinus reservoir-host of junin virus. | 1986 | 3543610 | |
| geographic patterns of allele frequencies in calomys musculinus reservoir-host of junin virus. | 1986 | 3543610 | |
| effect of actinomycin d on arenavirus growth and estimation of the generation time for a virus particle. | in an attempt to define the involvement of host transcription in arenavirus growth, a study was made of the effect of actinomycin d (amd) on the yields of infectious pichinde, tacaribe and junin viruses. the drug was added either immediately after virus adsorption or later after infection, at the stationary phase of virus growth. the time of exposure of the infected cells to the inhibitor was so chosen that the generation and release of virus into the medium took place in the presence of amd. a ... | 1986 | 3765824 |
| experimental argentine hemorrhagic fever: myocardial involvement in cebus monkey. | four cebus apella monkeys, to test a recently proposed model for testing neurovirulence of junín virus (jv) strains, were intracerebrally infected with 10(5) ld50 of the xj clone 3 strain of jv. there were no significant electrocardiographic abnormalities or gross lesions, but all infected monkeys exhibited a varying degree of histologic myocardial lesions including focal lymphoblastic infiltrates, vascular ruptures, and mild interstitial reactive change. one cebus showed lymphocytic infiltrates ... | 1986 | 3025446 |
| experimental argentine hemorrhagic fever: myocardial involvement in cebus monkey. | four cebus apella monkeys, to test a recently proposed model for testing neurovirulence of junín virus (jv) strains, were intracerebrally infected with 10(5) ld50 of the xj clone 3 strain of jv. there were no significant electrocardiographic abnormalities or gross lesions, but all infected monkeys exhibited a varying degree of histologic myocardial lesions including focal lymphoblastic infiltrates, vascular ruptures, and mild interstitial reactive change. one cebus showed lymphocytic infiltrates ... | 1986 | 3025446 |
| induction of junin virus persistence in adult athymic mice. | to determine the role of t lymphocytes in adult mice infected with junin virus, 60-day-old athymic (nu/nu) mice and their immunocompetent (nu/+) littermates were inoculated intracerebrally with 10(3) tcd50 of the xj strain. none of them exhibited neurologic illness during a 6-month observation period, and mortality was 3% for nu/nu and 7% for nu/+ animals. the main features in infected nu/nu mice were: high viral titers in brain, reaching a late peak (6.5 log/ml) 32 days postinoculation and pers ... | 1986 | 3026991 |
| modification of junin virus neurotropism in mice by selective brain or spinal cord passaging. | the percentage of suckling mice that developed paralysis after intracerebral junin virus (xj-jv pathogenic strain) inoculation (13.8%) consistently increased after 5 serial passages of virus-infected brain or spinal cord obtained from paralytic animals, reaching 37.9 and 45.7%, respectively. as expected, all paralytic mice exhibited an identical spinal cord histologic picture, with widespread jv antigen in spinal cord astrocytes and neurons, particularly the large motor neurons of the anterior h ... | 1986 | 3026992 |
| in vitro induction of human polymorphonuclear leukocyte damage by junin virus. | 1986 | 3027495 | |
| treatment of junin virus-infected guinea pigs with immune serum: development of late neurological disease. | guinea pigs infected with argentine hemorrhagic fever virus (junin) were treated with pooled, homologous convalescent sera. use of 15,000 or 5,000 therapeutic units of immune sera prevented all signs of illness when administered within 24 hr of infection. we could also prevent illness and death in infected guinea pigs as late as 6 days after infection if we used more antisera (30,000 therapeutic units/kg). in some treatment groups, surviving animals developed a late neurological syndrome with pr ... | 1986 | 3023540 |
| treatment of junin virus-infected guinea pigs with immune serum: development of late neurological disease. | guinea pigs infected with argentine hemorrhagic fever virus (junin) were treated with pooled, homologous convalescent sera. use of 15,000 or 5,000 therapeutic units of immune sera prevented all signs of illness when administered within 24 hr of infection. we could also prevent illness and death in infected guinea pigs as late as 6 days after infection if we used more antisera (30,000 therapeutic units/kg). in some treatment groups, surviving animals developed a late neurological syndrome with pr ... | 1986 | 3023540 |
| therapeutic effect of the antiviral agent ribavirin in junín virus infection of primates. | in order to assess the effect of the antiviral ribavirin on the course of junín virus infection in callithrix jacchus, seven inoculated monkeys were treated with 15 mg of the drug, twice a day, starting 6 days after infection when all animals were viremic. the three untreated controls showed typical signs of junín virus infection at 14 days pi and their mean time of death was 18 days. in contrast, no signs of illness were detected in ribavirin-treated animals until 24 days pi, when marmosets sho ... | 1986 | 3023541 |
| therapeutic effect of the antiviral agent ribavirin in junín virus infection of primates. | in order to assess the effect of the antiviral ribavirin on the course of junín virus infection in callithrix jacchus, seven inoculated monkeys were treated with 15 mg of the drug, twice a day, starting 6 days after infection when all animals were viremic. the three untreated controls showed typical signs of junín virus infection at 14 days pi and their mean time of death was 18 days. in contrast, no signs of illness were detected in ribavirin-treated animals until 24 days pi, when marmosets sho ... | 1986 | 3023541 |
| junín virus persistence in mice. | newborn mice surviving intracerebral infection with junín virus (jv) strain xj showed viral persistence in brain up to 140 days post-infection (p.i.). mild meningoencephalitis or encephalitis, but not the neutralizing antibody titres (ntab) correlated with virus presence. | 1987 | 2883864 |
| abrogation of junin virus encephalitis by critical cyclophosphamide timing and dosage. | junin virus-induced encephalitis in suckling mouse is a delayed-type hypersensitivity reaction, whose immunopathologic nature has been proven by suppressing the thymus-dependent response. cyclophosphamide (cy) given at day +6 post-infection (p.i.) has been shown to modulate infection, presumably by tdth lymphocyte inactivation. to determine critical timing and i.p. drug dose, brain histology and survival were studied in 3-day-old balb/c mice, inoculated i.c. with junin virus. optimal protection ... | 1987 | 2888291 |
| macrophages are involved in age-dependent resistance of rats to junin virus infection. | we attempted to correlate rat age with resistance to intraperitoneal infection with the xj strain of junin virus. accordingly, mortality, viral replication in macrophages and brain, as well as neutralizing antibody (na) levels were recorded in animals inoculated at 2, 5, 10 and 26 days of life. two-day-old animals demonstrated both the greatest mortality (86%) and viral replication in macrophages, allowing virus to reach the brain where high titers were detected. this age group also had the high ... | 1987 | 2822597 |
| [heterogeneity in the virulence of viral subpopulations derived from an attenuated strain of junin virus]. | 1987 | 2854292 | |
| intracerebral infection of cebus apella with the xj-clone 3 strain of junín virus. | to assess the usefulness of the south american primate cebus apella as a model for neurovirulence of junín virus, eight monkeys were inoculated with 10(5) ld50 of the attenuated xj-clone 3 junín virus strain by the intrathalamic route. after the second week, weight loss and polyadenopathies were observed in most animals, one-half of which had a transient leukothrombocytopenia. moderate clinical central nervous system (cns) involvement was present in four of eight monkeys, while the rest had only ... | 1987 | 3031201 |
| intracerebral infection of cebus apella with the xj-clone 3 strain of junín virus. | to assess the usefulness of the south american primate cebus apella as a model for neurovirulence of junín virus, eight monkeys were inoculated with 10(5) ld50 of the attenuated xj-clone 3 junín virus strain by the intrathalamic route. after the second week, weight loss and polyadenopathies were observed in most animals, one-half of which had a transient leukothrombocytopenia. moderate clinical central nervous system (cns) involvement was present in four of eight monkeys, while the rest had only ... | 1987 | 3031201 |
| experimental argentine hemorrhagic fever in rhesus macaques: virus-specific variations in pathology. | two isolates of junin virus (espindola and ledesma) inoculated into rhesus macaques produced distinct lesions which were strain-constant and similar to reported human cases of argentine hemorrhagic fever. the espindola isolate was associated with hemorrhagia, necrosis of bone marrow, and mild hepatocellular necrosis. ledesma isolate was associated with pronounced polioencephalomyelitis and autonomic ganglioneuritis, but very mild or absent hepatocellular necrosis, bone marrow necrosis, and hemor ... | 1987 | 3039051 |
| experimental argentine hemorrhagic fever in rhesus macaques: virus-specific variations in pathology. | two isolates of junin virus (espindola and ledesma) inoculated into rhesus macaques produced distinct lesions which were strain-constant and similar to reported human cases of argentine hemorrhagic fever. the espindola isolate was associated with hemorrhagia, necrosis of bone marrow, and mild hepatocellular necrosis. ledesma isolate was associated with pronounced polioencephalomyelitis and autonomic ganglioneuritis, but very mild or absent hepatocellular necrosis, bone marrow necrosis, and hemor ... | 1987 | 3039051 |
| effect of polymorphonuclear depletion on experimental argentine hemorrhagic fever in guinea pigs. | the role that polymorphonuclear leukocytes (pmn) may play in argentine hemorrhagic fever (ahf), an endemo-epidemic disease caused by junín virus (jv), was investigated in experimentally infected guinea pigs depleted of pmn by means of specific antiserum. in leucopenic animals the evolution of the infection with a highly pathogenic strain of jv was more severe, with earlier mortality and higher virus yields in blood and viscera. the pathological study showed similar lesions in both the control an ... | 1987 | 3040897 |
| effect of polymorphonuclear depletion on experimental argentine hemorrhagic fever in guinea pigs. | the role that polymorphonuclear leukocytes (pmn) may play in argentine hemorrhagic fever (ahf), an endemo-epidemic disease caused by junín virus (jv), was investigated in experimentally infected guinea pigs depleted of pmn by means of specific antiserum. in leucopenic animals the evolution of the infection with a highly pathogenic strain of jv was more severe, with earlier mortality and higher virus yields in blood and viscera. the pathological study showed similar lesions in both the control an ... | 1987 | 3040897 |
| protection of junín virus-infected marmosets by passive administration of immune serum: association with late neurologic signs. | argentine hemorrhagic fever (junín virus) is a human viral disease for which immune therapy proves effective, though a late neurologic syndrome is occasionally associated with the treatment. we attempted to determine in the infected marmoset callithrix jacchus whether immune therapy leads to protection and/or cns damage. fifteen c jacchus were inoculated with 10(3) tissue culture infectious dose 50% (tcid50) of the xj strain of junín virus. on day 6 post infection (pi), 12 primates were treated ... | 1987 | 3025358 |
| protection of junín virus-infected marmosets by passive administration of immune serum: association with late neurologic signs. | argentine hemorrhagic fever (junín virus) is a human viral disease for which immune therapy proves effective, though a late neurologic syndrome is occasionally associated with the treatment. we attempted to determine in the infected marmoset callithrix jacchus whether immune therapy leads to protection and/or cns damage. fifteen c jacchus were inoculated with 10(3) tissue culture infectious dose 50% (tcid50) of the xj strain of junín virus. on day 6 post infection (pi), 12 primates were treated ... | 1987 | 3025358 |
| [attenuation in the virulence of a mutant of junin virus in suckling mice]. | the virulence in neonatal mice of a temperature-sensitive mutant of junin virus, named c167, was studied. the thermosensitive properties of this mutant were tested by titration on vero cells at 37 and 40 degrees c. the ratio of infectivity 40/37 was approximately 100-fold lower for c167 with respect to xjc13 (table 1). the attenuation of c167 was determined by measurement of mean survival time and 50% lethal dose after intracerebral injection of 2 and 11 day old mice. for c167 the lethality inde ... | 1987 | 2825245 |
| effect of persistent infection with junin virus on growth and reproduction of its natural reservoir, calomys musculinus. | the effect of infection with junin virus on growth and reproduction of its natural reservoir, calomys musculinus, was studied. eighty-five c. musculinus were inoculated intranasally at birth with 100 tcid50 of cba an 9446 strain of junin virus and observed for 480 days. no clinical signs of neurologic illness were registered. infected animals showed an increased mortality rate of up to 70% between days 24-40 post-infection. this period of high mortality was preceded by low weight gain during lac ... | 1987 | 2825553 |
| effect of persistent infection with junin virus on growth and reproduction of its natural reservoir, calomys musculinus. | the effect of infection with junin virus on growth and reproduction of its natural reservoir, calomys musculinus, was studied. eighty-five c. musculinus were inoculated intranasally at birth with 100 tcid50 of cba an 9446 strain of junin virus and observed for 480 days. no clinical signs of neurologic illness were registered. infected animals showed an increased mortality rate of up to 70% between days 24-40 post-infection. this period of high mortality was preceded by low weight gain during lac ... | 1987 | 2825553 |
| tacaribe virus: a new alternative for argentine hemorrhagic fever vaccine. | tacaribe virus is know to protect guinea pigs and primates against lethal challenge with junín virus. a long-term study on the effect of tacaribe virus infection in the guinea pig was carried out to determine the extent of cross-protection and whether antigen and/or viral persistence and tissue damage could be detected in immune animals. viral titers, antigen expression in organs, and histologic lesions were sequentially searched for up to 540 days postinfection (pi). neutralizing antibodies (ab ... | 1987 | 2828522 |
| tacaribe virus: a new alternative for argentine hemorrhagic fever vaccine. | tacaribe virus is know to protect guinea pigs and primates against lethal challenge with junín virus. a long-term study on the effect of tacaribe virus infection in the guinea pig was carried out to determine the extent of cross-protection and whether antigen and/or viral persistence and tissue damage could be detected in immune animals. viral titers, antigen expression in organs, and histologic lesions were sequentially searched for up to 540 days postinfection (pi). neutralizing antibodies (ab ... | 1987 | 2828522 |
| interferon response in the guinea pig infected with junín virus. | the "in vivo" interferon (ifn) induction capacity of two junín virus strains--the attenuated xjcl3 and the intermediate virulent mc2--was studied in the guinea pig experimental model. three different doses of xjcl3 strain--2,000, 10,000, and 50,000 tcid50--and a single dose of 10,000 tcid50 of mc2 were assayed. animals were bled from day 0 to day 14 postinjection (pi) xjcl3 groups showed a constant serum ifn response. mc2 infection showed that 16% of the animals failed to develop interferonemia. ... | 1987 | 2445908 |
| interferon response in the guinea pig infected with junín virus. | the "in vivo" interferon (ifn) induction capacity of two junín virus strains--the attenuated xjcl3 and the intermediate virulent mc2--was studied in the guinea pig experimental model. three different doses of xjcl3 strain--2,000, 10,000, and 50,000 tcid50--and a single dose of 10,000 tcid50 of mc2 were assayed. animals were bled from day 0 to day 14 postinjection (pi) xjcl3 groups showed a constant serum ifn response. mc2 infection showed that 16% of the animals failed to develop interferonemia. ... | 1987 | 2445908 |
| circulating interferon in the guinea pig infected with the xj, prototype junin virus strain. | the interferon (ifn) induction capacity of the xj prototype strain of junín virus (jv) was investigated in the guinea pig model. circulating alpha ifn was detected in 50% of the animals from days 2 to 9 postinfection (pi) and in 100% at day 11 pi, when all animals were in the premortem stage. individual levels ranged from 20 to 1,280 guinea pig ifn units (gpifnu)/ml. a correlation between xj strain virulence and ifn titers was recorded. a possible role of ifn as a pathogenic factor in the outcom ... | 1988 | 2828536 |
| circulating interferon in the guinea pig infected with the xj, prototype junin virus strain. | the interferon (ifn) induction capacity of the xj prototype strain of junín virus (jv) was investigated in the guinea pig model. circulating alpha ifn was detected in 50% of the animals from days 2 to 9 postinfection (pi) and in 100% at day 11 pi, when all animals were in the premortem stage. individual levels ranged from 20 to 1,280 guinea pig ifn units (gpifnu)/ml. a correlation between xj strain virulence and ifn titers was recorded. a possible role of ifn as a pathogenic factor in the outcom ... | 1988 | 2828536 |
| long-term protection against argentine hemorrhagic fever in tacaribe virus infected marmosets: virologic and histopathologic findings. | tacaribe virus may represent a better alternative than attenuated strains of junin virus (jv) for immunization against argentine hemorrhagic fever (ahf) because of possible risk of persistent infection of disease associated with live, attenuated strains. callithrix jacchus marmosets, which suffer 100% mortality if inoculated with the pathogenic xj strain of jv, were used to evaluate possible tacaribe virus persistence, subclinical, or long-term disease and the duration of protection against chal ... | 1988 | 2832541 |
| long-term protection against argentine hemorrhagic fever in tacaribe virus infected marmosets: virologic and histopathologic findings. | tacaribe virus may represent a better alternative than attenuated strains of junin virus (jv) for immunization against argentine hemorrhagic fever (ahf) because of possible risk of persistent infection of disease associated with live, attenuated strains. callithrix jacchus marmosets, which suffer 100% mortality if inoculated with the pathogenic xj strain of jv, were used to evaluate possible tacaribe virus persistence, subclinical, or long-term disease and the duration of protection against chal ... | 1988 | 2832541 |
| evaluation of an enzyme-linked immunosorbent assay for quantitation of antibodies to junin virus in human sera. | an enzyme-linked immunosorbent assay (elisa) was evaluated for the quantitation of anti-junin virus (jv) antibodies, in 83 selected cases of argentine haemorrhagic fever (ahf). serum samples were studied in two groups to facilitate comparative analysis; the first group was elisa with indirect immunofluorescence (if) test, in the second elisa with plaque reduction neutralization test (print). from the results obtained by using elisa and if on the same serum samples, a clear tendency of elisa to d ... | 1988 | 2836465 |
| is vertical transmission sufficient to maintain junin virus in nature? | the quantitative contribution of vertical transmission to the prevalence rate of junin virus infection in subsequent generations of its natural reservoir, calomys musculinus, was analysed. data on mortality and reproduction of c. musculinus infected at birth with a wild strain of junin virus were used to estimate the infection-dependent relative survival rate (beta = 0.4849) and relative fertility of the infected host (alpha = 0.2088). prevalence rates of infection, obtained by mathematical simu ... | 1988 | 2838581 |
| is vertical transmission sufficient to maintain junin virus in nature? | the quantitative contribution of vertical transmission to the prevalence rate of junin virus infection in subsequent generations of its natural reservoir, calomys musculinus, was analysed. data on mortality and reproduction of c. musculinus infected at birth with a wild strain of junin virus were used to estimate the infection-dependent relative survival rate (beta = 0.4849) and relative fertility of the infected host (alpha = 0.2088). prevalence rates of infection, obtained by mathematical simu ... | 1988 | 2838581 |
| junin virus-induced delayed-type hypersensitivity suppression in adult mice. | junin virus (jv) infection of suckling mice leads to lethal meningoencephalitis consistent with a delayed-type hypersensitivity (dth)-like immune response. in contrast, there are no central nervous system (cns) alterations, and high antibody titers are induced in resistant adult mice. as a possible explanation, jv infection in adult mice may provoke dth depression. thus in this work we study the alterations induced by jv in the immune response of adult mice by using sheep red blood cells (srbc) ... | 1988 | 2839614 |
| junin virus-induced delayed-type hypersensitivity suppression in adult mice. | junin virus (jv) infection of suckling mice leads to lethal meningoencephalitis consistent with a delayed-type hypersensitivity (dth)-like immune response. in contrast, there are no central nervous system (cns) alterations, and high antibody titers are induced in resistant adult mice. as a possible explanation, jv infection in adult mice may provoke dth depression. thus in this work we study the alterations induced by jv in the immune response of adult mice by using sheep red blood cells (srbc) ... | 1988 | 2839614 |