cross-protection between tacaribe complex viruses. presence of neutralizing antibodies against junin virus (argentine hemorrhagic fever) in guinea pigs infected with tacaribe virus.cross-protection between junin virus and five other tacaribe complex viruses and the serological response of guinea pigs inoculated with tacaribe virus are reported here. previous infection with tamiami or pichinde viruses significantly delayed guinea pig deaths. a 58% survival rate was found among animals immunized with three doses of amapari virus, while guinea pigs inoculated with one dose of machupo or tacaribe virus were fully protected against junin virus. neutralization tests performed in ...1975178627
experimental biology and pathogenesis of junin virus infection in animals and man.a fatal disease resembling argentine haemorrhagic fever of man has been produced in guinea-pigs and mice by inoculation with junin virus. infected guinea-pigs show macroscopic and microscopic haemorrhagic lesions, marked bone marrow changes, decreased leukocytes and platelets in the peripheral blood, and impairment of immunological response. this response permits differentiation between pathogenic (xj) and attenuated (xj cl(3)) strains. guinea-pigs inoculated with the xj cl(3) strain develop an ...1975182401
junín virus infection of guinea pigs: electron microscopic studies of peripheral blood and bone marrow.thin sections of peripheral white blood cells and samples of bone marrow from guinea pigs infected with junín virus were examined by electron microscopy. in peripheral blood cells, 40% of the granulocytes showed cytoplasmic lysis seven days after viral infection. after day 11 up to 80% of these cells showed morphological alterations. however, no intra- or extracellular viral particles were detected in these samples. microscopy of bone marrow preparations revealed that 10% of the cells were alter ...1977191539
a rapid method for detecting junin virus viremia in the guinea pig.a method for detecting junin virus viremia in guinea pigs is described. the method consists of infecting bhk-21 cells with blood samples from infected guinea pigs; 48 h later, junin virus antigens are detected in the cells by indirect immunofluorescence. application of this technique to patients with argentine hemorrhagic fever may lead to the quickest method for the virologic diagnosis of this disease.1977197047
[experimental infection of the guinea pig with junin virus. clinical picture, dissemination, and elimination of the virus]. 1977197371
studies of blood coagulation and pathology in experimental infection of guinea pigs with junin virus. 1978207791
[infection of guinea pigs with an attenuated strain of junin virus xjcl3]. 1979232740
[experimental junin virus infection of guinea pigs. i. pathological anatomy]. 1976966989
clinical and epidemiological patterns of argentine haemorrhagic fever.the epidemiology of argentine haemorrhagic fever (ahf) is closely related to cricetine rodents acting as natural hosts of junin virus. the endemo-epidemic area, which has increased 5 times since the disease was first recognized 15-20 years ago, is located in a densely populated region of argentina. it has been shown that the virus of lcm is active in humans and rodents of the ahf endemic area; this demonstrates the simultaneous presence of two arenaviruses pathogenic for man in a given geographi ...19751085212
directions for future research on the pathogenesis of arenaviral infections.the pathogenesis of arenavirus infection is considered separately for the haemorrhagic fever (hf) syndrome and for lymphocytic choriomeningitis (lcm) virus infection of rodents. experimental models of hf have received only limited study, mainly because of the virulence of the causal agents. two useful models (junin virus in guinea-pigs and machupo virus in rhesus monkeys) are now available and an attempt is made to delineate crucial questions for future studies, including the physiology of shock ...19751085229
[editorial: ultrastructure of bone marrow and peripheral blood of guinea pigs infected with junin virus]. 19751196119
experimental neuroinvasiveness of wild and laboratory junin virus strains.the neuroinvasiveness of candid 1 and xjcl3 laboratory strains and cbalv4454 and cbafha5069 wild strains of junin virus was studied in albino mice, guinea pigs, and a south american wild rodent, calomys musculinus (cm), of different ages inoculated by a non-neural route. infectivity in brain, blood and organs, as well as lethality, were determined. the results with the 3 hosts indicate that junin virus neuroinvasiveness is virus-strain-dependent, host species- and age-dependent, with the candid ...19921329167
protection of guinea pigs against experimental argentine hemorrhagic fever by purified human igg: importance of elimination of infected cells.antibody-containing plasma from patients recovered from argentine hemorrhagic fever (ahf) is of proven value in treatment of the acute disease, but the possibility of transmitting blood-borne organisms such as hiv and hepatitis virus detracts from this approach. purified human immune plasma fractions igg1,2,4, igg1,2,3,4 and f(ab')2 neutralized junin virus in vitro. igg1,2,3,4 and igg1,2,4 lysed (in the presence of complement) cells infected with junin virus, and protected infected guinea pigs f ...19901965845
neurovirulence of wild and laboratory junin virus strains in animal hosts.the neurovirulence of candid #1 and xjcl3 laboratory strains and cbalv4454 and cbafha5069 wild strains of junin virus was studied in albino mice, guinea pigs, and a south american wild rodent, calomys musculinus, of different ages inoculated by the intracerebral route. infectivity in brain and organs, lethality, and neuropathological lesions were determined. the laboratory and wild strains showed similar neurovirulence only in 2-day-old mice. the neurovirulence of laboratory strains decreased wi ...19902177781
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 ...19852413752
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. ...19872445908
actions of complement on junin virus.fresh sera from normal rhesus monkeys, guinea pigs, and rabbits inactivated 90%-99% of the infectivity of vero cell-passaged, attenuated strains of junin virus (jv) within 60 minutes. selective depletion studies showed that inactivation occurred by the classical complement pathway. complement had little effect on virulent jv strains. adsorption of the fresh sera with jv-infected vero cells showed that inactivation was not mediated by low levels of antibodies in normal sera. the cells used for pr ...19892546249
protective effect of a low-dose of cyclophosphamide in experimental infection of guinea pigs with junin virus.administration of cyclophosphamide (cy) to guinea pigs infected with a lethal strain of junin virus (jv) delayed the time of death, with survival of a small number of animals. virological studies showed a temporary decrease of virus concentration in blood and viscera shortly after the cy injection. in the pathological study no differences were found in the organic lesions present in cy-treated and nontreated animals, with the exception of the pulmonary alterations. in cy-treated guinea pigs the ...19892557385
formalin inactivated junin virus: immunogenicity and protection assays.the aim of this study was to determine if junin virus inactivated with formalin (fa) was immunogenic and able to elicit a protective response in the guinea pig. the xj-clone 3 strain of junin virus grown in vero cells was exposed to fa at 0 degrees c. the following inactivated antigens were prepared: a1, 0.1% fa for 50 hr; a2, 0.1% fa for 50 hr followed by concentration with polyethylene glycol (peg); b1, 0.05% fa for 70 hr; b2, 0.05% fa for 70 hr plus peg concentration; c, 0.1% fa for 50 hr fol ...19892559158
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 ...19872828522
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 ...19882828536
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) ...19882839614
viral strain dependent differences in experimental argentine hemorrhagic fever (junin virus) infection of guinea pigs.guinea pigs infected with low-passage junin virus of human origin showed viral strain dependent differences in mortality, ld50, time to death, and in viral spread and distribution. different junin strains appeared to cause at least two broad patterns of argentine hemorrhagic fever in guinea pigs. a number of strains of junin virus caused a viscerotropic type of illness in which virus replicated predominantly in lymph nodes, spleen, and bone marrow. with the most severe visceral forms of argentin ...19882846464
susceptible adult murine model for junin virus.the adult mouse model had been considered resistant to junin virus (jv) infection. however, we found that c3h/hej murine strain proved highly susceptible up to 5 months of age to intracerebral inoculation with the prototype xj jv strain, showing neurological signs and 80-90% mortality within 13 days. neutralizing antibodies (nt ab) were absent, but low immunofluorescent ab levels (1:5) were detected as from day +7. the virus could only be rescued by coculture of brain samples with vero cells. hi ...19882850346
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 ...19862854602
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 ...19852981364
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 ...19852982762
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.19852983010
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 ...19852983013
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 ...19852989214
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 ...19853000979
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.19863013087
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 ...19863023540
[modification of the course of junin virus infection in guinea pigs by administration of immune sera]. 19853023791
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 ...19873040897
[electrolyte modifications of the plasma of guinea pigs infected by junin virus]. 19684238205
[changes in lipids in the blood of guinea pigs infected with junin virus]. 19694259111
phytohaemagglutinin unresponsiveness in leukopenia induced by junin virus in guinea pigs. 19724402253
tacaribe virus infection of guinea-pig. virus distribution, appearance of antibodies and immunity against junin virus infection. 19674970562
[leukocyte alterations produced in guinea pigs by 2 strains of junin virus]. 19715162332
[hematologic studies in guinea pigs infected with junin virus xj and xj, c13 strains]. 19695345414
[immunization against argentinian hemorrhagic fever using an attenuated strain of junin virus. i. modified strain of junin virus. immunization of guinea pigs]. 19695346952
alterations in the enzymatic activity of plasma of guinea pigs infected with junín virus. 19705460528
[immunological studies with junin virus. i. formation of antibodies in guinea pigs inoculated with live viruses]. 19675600651
[immunological studies with the junin virus. ii. acquired immunity in guinea pigs with a formol-inactivated virus]. 19675619831
[lipid changes in the serum of guinea pigs infected with junin virus (argentinian hemorrhagic fever)]. 19685738395
[experimental hemorrhagic fever in guinea pigs (junín virus). contagion and elimination of the virus]. 19655844726
[electrophoresis of the serum proteins of guinea pigs inoculated with junín virus (on paper and polyacrylamide gel)]. 19655861780
[experimental hemorrhagic fever. histaminemia in guinea pigs inoculated with junín virus]. 19655888139
[electrolyte changes in the blood of guinea pigs infected with junin virus]. 19665987610
the guinea pig model for argentine hemorrhagic fever.guinea pigs infected by the peripheral route with the xj pathogenic strain of junin virus showed viscerotropism mainly in reticulo-phagocytic rich organs. by immunofluorescence, heavy infection of reticular-phagocytic cells was demonstrated, supporting the leading role of these cell types. absence of neurotropism was demonstrated by the inability to recover infectious virus, as well as the absence of antigens, immunoglobulins, or 3rd component of complement deposits, in cells, vessels, or mening ...19846095695
[suckling guinea pigs as a differential indicator of the virulence of attenuated strains of junin virus]. 19846100499
[effect of the host cells in the crossed neutralization reactions between junín and tacaribe viruses ].it has been previously reported that guinea pigs inoculated with tacaribe virus grown in suckling mouse brain, develop specific anti-junín neutralizing antibodies (na) after 45 days of infection and a typical secondary response after junín virus challenge. since in these experiments both viruses were grown in suckling mouse brain doubt was raised about the specificity of na, considering the possibility that they were raised against host-cell antigens. in order to test this interpretation the fol ...19846101038
[development of the infection in guinea pigs infected with the attenuated variant xjo of junín virus].as previously shown, the xjo variant of junin virus (jv) is attenuated and elicits in guinea pigs a lasting humoral response and resistance to the challenge with xj pathogenic strain, during at least three months. in this paper the long term evolution of guinea pigs inoculated with xjo by im route was studied. ten animals were infected with 10(3) pfu of xjo at day 0 (group i) and an other 10, at days 0 and 77 (group ii). another 30 guinea pigs were inoculated with 10(2) pfu at day 0 (group iii) ...19836101069
[experimental infection of guinea pigs with tacaribe virus: effect on the functioning of the immunocompetent system].tacaribe virus is the member most closely related to junín virus within the tacaribe complex. it has been demonstrated that both viruses are indistinguishable by complement-fixation, due to the high cross-reactivity. however, adult guinea pigs are highly sensitive to infection with the xj pathogenic strain of junín virus whereas tacaribe virus is nonpathogenic for this species. furthermore this last virus protects them against junín virus. the xj strain reduces the immune response of guinea pigs ...19816101101
modification of junin virus neutropism in the guinea pig model.virulent and attenuated junin virus (jv) strains have been employed to study the influence of virus passage history on the neurotropism for guinea pigs. five i.p. successive passages (p1-p5) of the pathogenic jv-xj strain and of the attenuated xjo variant were performed in guinea pig spleen. viral titrations of organ suspensions were made through p1-p5 passages. the xj strain produced a widespread infection in p1 guinea pigs with viral dissemination to all organs except brain, in p5 animals the ...19846147995
protection of guinea pigs inoculated with tacaribe virus against lethal doses of junin virus.guinea pigs were protected against lethal doses of junin virus by a previous inoculation with tacaribe virus. fourteen guinea pigs were infected with 10(6) 50% lethal doses (ld50) of tacaribe virus and superinfected 45 days later with 10(3) ld50 of junin virus. appropriate control groups for both infections were also studied. the replication of junin virus was impaired, as no virus was isolated from blood and organs of animals killed on days 9 and 11 after infection. high levels of neutralizing ...19806245155
in vitro inactivation of complement by a serum factor present in junin-virus infected guinea-pigs.a serum factor(s) of guinea-pigs infected with junin virus, the etiological agent of argentine haemorrhagic fever, is endowed with a potent anticomplementary activity. it is resistant to heat (56 degrees, 30 min) and elutes from a sephadex g-200 column between albumin and haemoglobin. it is ineffective in the presence of edta or egta and does not sediment at 82,000 g. it has no direct effect on c4 unless functional cl is present. however, it induces cl activation that consumes c4 haemolytic acti ...19806247264
[various aspects of experimental infection of the guinea pig with an attenuated variant of junin virus]. 19806259493
junin virus infection of guinea pigs: immunohistochemical and ultrastructural studies of hemopoietic association between viral antigens, cytopathic effect (cpe) and viral titers in blood and lymphoid tissues suggests a direct cpe of junin virus on the lymphopoietic organs of guinea pigs infected with 10(3) 50% lethal doses of the xj prototype strain. after seven days of infection, all lymphoreticular organs had infectivity titers higher than those for blood. virus was recovered from bone marrow and lymph nodes at day 5 after infection; peak titers were obtained from bone marrow, spleen, and ...19816260868
description of a bhk/21 cell line persistently infected with junin virus: its use in diagnostic procedures.a bhk/21 cell line persistently infected by an arenavirus is described. during four consecutive passages, 30-45% of the cells showed granular cytoplasmic antigen by indirect immunofluorescence, employing both argentine hemorrhagic fever convalescent sera and sera from animals immunized with junin virus. virus isolated from the cells killed suckling mice but not adult mice and protected guinea pigs against further challenge with the virulent prototype strain of junin virus. neutralization tests s ...19806263820
[protection induced in guinea pigs by the variant xj0 of junin virus]. 19816267412
[immunologic markers of attenuation in guinea pigs infected with strains or variants of junin virus]. 19816267413
cell-mediated immunity and lymphocyte populations in experimental argentine hemorrhagic fever (junín virus).guinea pigs infected with the xj prototype strain of junín virus reproduce the main features of argentine hemorrhagic fever, showing hemorrhages, leukothrombocytopenia, and focal lymphoid tissue necrosis. viral lymphotropism is shown by the presence of viral antigens, severe cytopathic effect, and high virus titers in lymphoid organs. a pronounced depression of humoral immune response to sheep erythrocytes as well as to the virus is described. this study was carried out to determine whether cell ...19816273314
new attenuation marker for junin virus based on immunologic responses of guinea pigs.a new attenuation marker to distinguish a virulent strain (xjjv) from an attenuated strain (xjc13jv or xjojv) of junin virus by means of the humoral and cellular responses to unrelated antigens was studied in guinea pigs. strain xjjv suppressed the humoral immune response, as shown by the lower titers of precipitating antibody to ovalbumin. the concomitant decrease in serum complement level contributed to a milder arthus cutaneous reactivity. in contrast, the attenuated strains did not decrease ...19826278027
[effect of experimental infection of pregnant guinea pigs with junin virus]. 19816287523
cytogenetic effect of two strains of junin virus in the guinea pig.the cytogenetic effect of two strains of junin virus on bone marrow chromosomes of the guinea pig was studied. animals infected with the attenuated strain xj-cl3 showed no differences from control animals. guinea pigs inoculated with the pathogenic strain xj exhibited a significant increase of abnormal cells, chromatid breaks, and chromosome fragments. the clastogenic ability of the xj strain is similar to the reported effect of other viruses, while the xj-cl3 strain does not appear to be clasto ...19836298143
congenital and perinatal infection with junin virus in guinea pigs.junin virus infection in guinea pigs is known to be similar to human argentine hemorrhagic fever (ahf). the guinea pig was chosen as a model for transplacental transmission of junin virus, as both guinea pig and man have a similar placental structure. pregnant guinea pigs were infected with the pathogenic xj strain of junin virus intramuscularly route at different stages of pregnancy. the group infected during the last third of pregnancy produced 16 newborn, but mortality reached 100%: 18% were ...19836302220
[action of cyclophosphamide on intracerebral infection of guinea pigs with junin virus]. 19826302439
[the nursing guinea pig as an indicator of junin virus neurovirulence]. 19826306384
[infection of the lung with junin virus in experimental argentinian hemorrhagic fever of the guinea pig]. 19836308382
protection against a pathogenic strain of junin virus by mucosal infection with an attenuated order to determine the degree of mucosal infectivity of the attenuated xjcl3 strain of junin virus, guinea pigs were orally or nasally inoculated. infectivity was 85% for the oral and 100% for the nasal route, as detected by death or serum antibody development. the presence of serum antibodies was closely associated with resistance to challenge with the xj pathogenic strain, which killed 100% of controls when inoculated by the parenteral or nasal route. however, mortality rates after mucosal ...19836309026
in vivo replication of pathogenic and attenuated strains of junin virus in different cell populations of lymphatic tissue.lymphatic tissue is one of the main sites for replication of junin virus. to characterize which cells are involved in that replication, the presence of junin virus in purified populations of macrophages and dendritic cells from the spleens of guinea pigs infected with pathogenic and attenuated strains was investigated by immunofluorescence and intracerebral inoculation into newborn mice. the pathogenic strain was present both in macrophages and in dendritic cells, but the attenuated strain selec ...19836309667
pathogenicity of an attenuated strain (xjcl3) of junin virus. morphological and virological studies in experimentally infected guinea pigs.infection of guinea pigs with an attenuated strain of junin virus (jv) produced 16% mortality between days 17 and 27 postinfection (p.i.). the morphological study showed a marked pancreatitis between days 6 and 23 p.i. and meningoencephalitis between days 17 and 20 p.i. in a large proportion of the animals. these lesions were coincident with the presence of jv antigenic determinants in the pancreatic acinar cells, neurons and blood vessels of the brain. infectious virus could be isolated from ly ...19836317604
[neuropathology of the junin virus in the guinea pig: new contributions]. 19836325848
transplacental infection in guinea pigs inoculated with an attenuated strain of junin virus.transplacental infection by the attenuated xjc13 strain of junin virus (jv) in the guinea pig model was evaluated. 5 pregnant guinea pigs were infected intramuscularly at 45 +/- 3 days of pregnancy. 4 animals were killed at 14 days postinfection (p.i.), and 1 was sacrificed at 137 days p.i. at the end of its second pregnancy. evidence of jv was obtained by vero cell cocultivation in all 14 fetuses harvested (brain and/or spleen) and in 10 of 11 placentas. the results strongly suggest that the at ...19846327563
persistence of attenuated junin virus strains in guinea pigs infected by im or ic routes. 19846330233
[congenital infection by junin virus in guinea pigs]. 19817321861
the role of mononuclear blood cells in experimental junin virus spread to the central nervous system.the neuroinvasiveness of junin virus depends on the viral strain, animal species, and age. the role of infected blood cells in hematogenous junin virus spread to the central nervous system (cns) was studied by determining the growth in pheripheral mononuclear cells and brain tissue of candid 1 and xjcl3 laboratory strains, in calomys musculinus and guinea pigs. the present study demonstrated that junin virus replicates in circulating peripheral lymphocytes and macrophages of 11-day-old guinea pi ...19958825295
homologous and heterologous glycoproteins induce protection against junin virus challenge in guinea pigs.tacaribe virus (tacv) is an arenavirus that is genetically and antigenically closely related to junin virus (junv), the aetiological agent of argentine haemorrhagic fever (ahf). it is well established that tacv protects experimental animals fully against an otherwise lethal challenge with junv. to gain information on the nature of the antigens involved in cross-protection, recombinant vaccinia viruses were constructed that express the glycoprotein precursor (vv-gtac) or the nucleocapsid protein ...200010769070
[experimental hemorrhagic fever in the guinea pig (junin virus)]. 196113872119
[experimental hemorrhagic fever in the guinea pig induced by the junin virus]. 196314117805
[immunization of guinea pigs against the junin virus by inoculation with tacaribe virus]. 196414168726
protection against junin virus by immunization with live tacaribe virus. 196514328956
[effect of intracerebral inoculation of junin virus in guinea pigs]. 198215170953
[preclinical assay of candid #1 vaccine against argentine hemorrhagic fever made in argentina].candid #1 vaccine against argentine hemorrhagic fever produced in usa versus lots of the same vaccine made in argentina were compared in guinea pigs regarding safety, immunogenicity and protective efficacy against a challenge with pathogenic junin virus. lots no exp 3, 7a and 8a of argentine origin as well as lot tsi 5-1-92 from usa were inoculated in guinea pigs of 250-400 g in two consecutive assays. ten animals inoculated with saline performed as normal controls in each experiment. parameters ...200516193711
pathogenesis of xj and romero strains of junin virus in two strains of guinea pigs.argentine hemorrhagic fever (ahf), a systemic infectious disease caused by infection with junin virus, affects several organs, and patients can show hematologic, cardiovascular, renal, or neurologic symptoms. we compared the virulence of two junin virus strains in inbred and outbred guinea pigs with the aim of characterizing this animal model better for future vaccine/antiviral efficacy studies. our data indicate that this passage of the xj strain is attenuated in guinea pigs. in contrast, the r ...200818689636
tc83 replicon vectored vaccine provides protection against junin virus in guinea pigs.junin virus (junv) is the etiological agent of the potentially lethal, reemerging human disease, argentine hemorrhagic fever (ahf). the mechanism of the disease development is not well understood and no antiviral therapy is available. candid 1, a live-attenuated vaccine, has been developed by the us army and is being used in the endemic area to prevent ahf. this vaccine is only approved for use in argentina. in this study we have used the alphavirus-based approach to engineer a replicon system b ...201020452431
proteomic analysis of pichindé virus infection identifies differential expression of prothymosin-alpha.the arenaviruses include a number of important pathogens including lassa virus and junin virus. presently, the only treatment is supportive care and the antiviral ribavirin. in the event of an epidemic, patient triage may be required to more effectively manage resources; the development of prognostic biomarker signatures, correlating with disease severity, would allow rational triage. using a pair of arenaviruses, which cause mild or severe disease, we analyzed extracts from infected cells using ...201020706531
rescue from cloned cdnas and in vivo characterization of recombinant pathogenic romero and live-attenuated candid #1 strains of junin virus, the causative agent of argentine hemorrhagic fever disease.the new world arenavirus junin virus (junv) is the causative agent of argentine hemorrhagic fever (ahf), which is associated with high morbidity and significant mortality. several pathogenic strains of junv have been documented, and a highly attenuated vaccine strain (candid #1) was generated and used to vaccinate the human population at risk. the identification and functional characterization of viral genetic determinants associated with ahf and candid #1 attenuation would contribute to the elu ...201021123388
Effective oral favipiravir (T-705) therapy initiated after the onset of clinical disease in a model of arenavirus hemorrhagic Fever.Lassa and Junín viruses are the most prominent members of the Arenaviridae family of viruses that cause viral hemorrhagic fever syndromes Lassa fever and Argentine hemorrhagic fever, respectively. At present, ribavirin is the only antiviral drug indicated for use in treatment of these diseases, but because of its limited efficacy in advanced cases of disease and its toxicity, safer and more effective antivirals are needed.201122022624
[study of bone marrow in experimental argentine hemorrhagic fever. role of the megakaryocyte.]in previous morphological studies on bone marrow of guinea pigs infected with junin virus, the coexistence of viral particles, antigens and cytopathic effects were observed in megakaryocytes. in addition, bone marrow is one of the organs where highest virus titers were obtained. however, although other myeloid cells presented intense cytopathic effect, viral antigens were observed only in reticular cells and virus particles were seen sporadically associated with immature cells. this study was de ...198022167697
effect of ribavirin on junin virus infection in guinea pigs.junin virus (junv) is the aetiological agent of argentine haemorrhagic fever. the pathogenesis of the infection is not well understood, no licensed vaccines exist and no specific antiviral therapy is available. previous studies have demonstrated the ability of ribavirin to delay and reduce junv disease and virus burden in guinea pigs without preventing death. based on available data, we performed three different studies to determine the efficacy of ribavirin against junv in the guinea pig model ...201222212688
glycoprotein-specific antibodies produced by dna vaccination protect guinea pigs from lethal argentine and venezuelan hemorrhagic fever.several members of the arenaviridae can cause acute febrile diseases in humans, often resulting in lethality. the use of convalescent-phase human plasma is an effective treatment in humans infected with arenaviruses, particularly species found in south america. despite this, little work has focused on developing potent and defined immunotherapeutics against arenaviruses. in the present study, we produced arenavirus neutralizing antibodies by dna vaccination of rabbits with plasmids encoding the ...201626792737
absence of an n-linked glycosylation motif in the glycoprotein of the live-attenuated argentine hemorrhagic fever vaccine, candid #1, results in its improper processing, and reduced surface expression.junin virus (junv), a highly pathogenic new world arenavirus, is the causative agent of argentine hemorrhagic fever (ahf). the live-attenuated candid #1 (can) strain currently serves as a vaccine for at-risk populations. we have previously shown that the can glycoprotein (gpc) gene is the primary gene responsible for attenuation in a guinea pig model of ahf. however, the mechanisms through which the gpc contributes to the attenuation of the can strain remain unknown. a more complete understandin ...201728220142
monoclonal antibody therapy for junin virus infection.countermeasures against potential biothreat agents remain important to us homeland security, and many of these pharmaceuticals could have dual use in the improvement of global public health. junin virus, the causative agent of argentine hemorrhagic fever (ahf), is an arenavirus identified as a category a high-priority agent. there are no food and drug administration (fda) approved drugs available for preventing or treating ahf, and the current treatment option is limited to administration of imm ...201627044104
low-dose ribavirin potentiates the antiviral activity of favipiravir against hemorrhagic fever viruses.favipiravir is approved in japan to treat novel or re-emerging influenza viruses, and is active against a broad spectrum of rna viruses, including ebola. ribavirin is the only other licensed drug with activity against multiple rna viruses. recent studies show that ribavirin and favipiravir act synergistically to inhibit bunyavirus infections in cultured cells and laboratory mice, likely due to their different mechanisms of action. convalescent immune globulin is the only approved treatment for a ...201626711718
[sensitivity and specificity of the elisa kit for the detection of antidobies to junin virus].the goal of this work was to describe methodological approaches to determination of sensitivity and specificity of the enzyme-linked immunosorbent assay kit (elisa kit) for detection of the specific anti-junin virus (jv) antibody. comparison of elisa to plaque reduction neutralization test (prnt) showed direct relationship between antibody titers in the samples of serum of immunized animals, determined by either prnt or elisa methods. the obtained results provided an opportunity to form the pane ...201526021075
the glycoprotein precursor gene of junin virus determines the virulence of the romero strain and the attenuation of the candid #1 strain in a representative animal model of argentine hemorrhagic fever.the new world arenavirus junin virus (junv) is the causative agent of argentine hemorrhagic fever (ahf), a potentially deadly disease endemic to central regions of argentina. the live-attenuated candid #1 (can) strain of junv is currently used to vaccinate the human population at risk. however, the mechanism of attenuation of this strain is still largely unknown. therefore, the identification and functional characterization of viral genetic determinants dictating junv virulence or attenuation wo ...201525810546
[study of sensitivity of laboratory animals to a causative agent of argentine hemorrhagic fever].study sensitivity of laboratory animals to a causative agent ofargentine hemorrhagic fever.201425286529
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