| involvement of the cytoskeleton in junin virus multiplication. | the role of the cellular cytoskeleton in junin virus (jv) infection was explored in two ways. firstly, the action of inhibitors that affect individual cytoskeletal systems (microtubules or microfilaments) selectively was analysed. it was found that perturbations of microtubule or microfilament networks caused by colchicine, nocodazole, nifedipine, egta or dmso strongly affected virion production and viral protein expression at non-cytotoxic concentrations. secondly, the extent of association of ... | 1999 | 9934697 |
| proinflammatory cytokines and elastase-alpha-1-antitrypsin in argentine hemorrhagic fever. | argentine hemorrhagic fever (ahf) is a disease caused by junin virus. in the acute phase, patients present hematologic and neurologic involvement with high levels of interferon-alpha and tumor necrosis factor-alpha (tnf-alpha. nineteen patients with a confirmed diagnosis of ahf were studied: six severe, four moderate and nine mild cases. serum levels of interleukin-6 (il-6), il-6 soluble receptor (il-6sr), il-8, il-10, and elastase-alpha1-antitrypsin complex (e-alpha 1at) were assayed by elisas. ... | 1999 | 9988328 |
| evaluation of the antiviral activity of natural sulfated polyhydroxysteroids and their synthetic derivatives and analogs. | disodium 3beta,21-dihydroxypregn-5-en-20-one disulfate (2), sodium 3beta,21-dihydroxypregn-5-en-20-one 3-sulfate (3), sodium 3beta,21-dihydroxypregn-5-en-20-one 21-sulfate (4), and disodium 3beta,6alpha-dihydroxy-5alpha-pregnan-20-one disulfate (6) have been synthesized and completely characterized for the first time from readily available materials. sulfation was performed using triethylamine-sulfur trioxide complex in dimethylformamide as the sulfating agent. selective sulfation of 3beta,21-di ... | 1999 | 10406483 |
| cell differentiation increases astrocyte phagocytic activity. a quantitative analysis of both gfap labeling and pas-stained yeast cells. | since efficiency of phagocytic potential in activated astrocytes is still a subject of controversy, an attempt was made to quantify simultaneously phagocytic activity and astrocyte differentiation. resorting to junin virus, known to induce astrocyte activation, infected vs control samples of cultured rat astroglial cells were serially harvested up to day 12 post-inoculation (pi), and subjected to a triple staining procedure consisting in immunoperoxidase labeling of gfap, periodic acid-schiff (p ... | 1999 | 10413896 |
| clinical case definitions for argentine hemorrhagic fever. | argentine hemorrhagic fever (ahf) is a potentially lethal infection in argentina. the case-fatality ratio is >15%, but treatment reduces the mortality rate to <1%. diagnosis is based on clinical and laboratory criteria, but no case definition has been validated. a chart review was conducted for patients hospitalized with suspected ahf. individuals with a fourfold rise in antibody titer were classified as cases. the combination of a platelet count of <100,000/mm3 and a white blood cell (wbc) coun ... | 1999 | 10452640 |
| analysis of viral glycoproteins by glycosidic digestion inside a polyacrylamide gel. | we adapted the method described by cleveland et al. (1977); (peptide mapping by limited proteolysis in sodium dodecyl sulphate and analysis by gel electrophoresis. j. biol. chem. 252, 1102-1106) to study the glycosidic residues linked to the viral glycoproteins of two enveloped viruses: junin virus (jv) and rubella virus (rv). radioiodinated glycoproteins were obtained from purified virions, isolated from sds-polyacrylamide gels and then hydrolysed by specific glycosidases inside a second gel. n ... | 1999 | 10471032 |
| [inhibition of junin virus multiplication by caffeine]. | the inhibitory activity of caffeine, a pharmacologically active compound, on junin virus (jv) multiplication in vero cells was evaluated by a virus yield inhibition assay. the compound achieved a dose-dependent inhibition of virus production at concentrations not affecting cell viability. the 50% inhibitory concentration (ic50) and the 90% inhibitory concentration (ic90) were 9.0 mm and 10.8 mm, respectively. from time of addition experiments, it can be concluded that caffeine inhibited an early ... | 1999 | 10509392 |
| myristic acid analogs are inhibitors of junin virus replication. | the effects of two myristic acid analogs on junin virus (jv) replication were investigated. the compounds chosen for the study were dl-2-hydroxymyristic acid (2ohm), an inhibitor of n-myristoyltransferase (nmt), which binds the enzyme and blocks protein myristoylation, and 13-oxamyristic acid (13om), a competitive inhibitor of nmt which incorporates into the protein instead of myristic acid. both types of analogs achieved dose-dependent inhibition of viral multiplication at concentrations not af ... | 1999 | 10611737 |
| antiviral effect of brassinosteroids against herpes virus and arenaviruses. | a natural brassinosteroid and a series of synthetic derivatives were found to be good inhibitors of herpes simplex virus type 1 (hsv-1) and arenavirus replication in cell culture. the synthetic compounds tested were analogues of the 24(s) ethylbrassinone. compounds (22 r,23 r,24s)-2alpha, 3alpha,5alpha,22,23-pentahydroxy-stigmastan-6-one and (22r,23r,24s)-3beta-bromo-5alpha,22,23-trihydroxy stigmastan-6-one were cytotoxic at concentrations of 20-40 microm. (22s,23s,24s)-2alpha,3alpha,22,23-tetra ... | 2000 | 10693656 |
| 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 ... | 2000 | 10769070 |
| 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 ... | 2000 | 10769070 |
| relationship between hematopoietic growth factors levels and hematological parameters in argentine hemorrhagic fever. | argentine hemorrhagic fever (ahf) is a viral disease caused by junin virus and characterized by hematologic and neurological involvement. the main hematologic features are leukopenia, thrombocytopenia, and bone marrow hypoplasia. hematopoietic growth factors serum levels were measured by elisa technique in forty-eight patients with confirmed diagnosis of ahf. patients were classified according to the clinical picture in 15 severe (scf), 17 moderate (mocf), and 16 mild (micf) cases. erythropoieti ... | 2000 | 10815780 |
| genetic diversity of the junin virus in argentina: geographic and temporal patterns. | rna was purified from 39 strains of cell-cultured junin virus (jun) from central argentina, which included both human- and rodent-derived isolates (a total of 26 and 13, respectively), as well as from 2 laboratory jun strains, xj cl3 and xj #44. jun-specific primers were used to amplify a 511-nucleotide (nt) fragment of the nucleocapsid protein gene and a 495-nt fragment of the glycoprotein 1 (gp1) gene. genetic diversity among jun strains studied was up to 13% at the nt level and up to 9% at th ... | 2000 | 10873755 |
| genetic diversity of the junin virus in argentina: geographic and temporal patterns. | rna was purified from 39 strains of cell-cultured junin virus (jun) from central argentina, which included both human- and rodent-derived isolates (a total of 26 and 13, respectively), as well as from 2 laboratory jun strains, xj cl3 and xj #44. jun-specific primers were used to amplify a 511-nucleotide (nt) fragment of the nucleocapsid protein gene and a 495-nt fragment of the glycoprotein 1 (gp1) gene. genetic diversity among jun strains studied was up to 13% at the nt level and up to 9% at th ... | 2000 | 10873755 |
| antiviral and virucidal activities against arenaviruses of zinc-finger active compounds. | fifteen antiretroviral zn-finger active compounds with diverse chemical structures, including azoic compounds, hydrazide derivatives, disulphide-based reagents and others were screened in vitro against junin virus (junv), the aetiological agent of argentine haemorrhagic fever, by a virus yield inhibition assay in vero cells. cytotoxicity was evaluated simultaneously by the mtt method. of the compounds, three were totally inactive as antivirals, nine presented moderate anti junv-activity and thre ... | 2000 | 10901294 |
| a quantitative approach to correlate astrocyte differentiation and phagocytic activity. | a triple staining procedure (pap labeling for gfap, pas reaction for added yeast cells and hematoxylin for nuclear staining of the whole cell monolayer) had disclosed that junin virus infection enhanced phagocytic activity by inducing greater astrocyte differentiation. here, we resorted to a mathematical approach for simultaneous evaluation of astrocyte differentiation and potential phagocytosis. at light microscopy level, the total number of: a) pas-stained yeast cells, b) pas-stained yeast cel ... | 2000 | 10979613 |
| zinc-binding properties of junín virus nucleocapsid protein. | the arenavirus nucleocapsid protein (n) is a highly basic 63 kda protein with a dual function during the virus life-cycle. first, it is involved in essential steps of genome replication, promoting the synthesis of the full-length antigenomic copy of s rna, and second it associates with the genomic rna to form the nucleocapsid. we have expressed the n protein of junín virus in e. coli and shown that it binds zinc in vitro. this property is in agreement with the presence in the carboxy-terminal re ... | 2001 | 11125165 |
| arenavirus nucleocapsid protein displays a transcriptional antitermination activity in vivo. | rna polymerase pausing and transcriptional antitermination regulates gene activity in several systems. in arenavirus infected cells the switch from transcription to replication is subjected to a hairpin-dependent termination and requires protein synthesis to bypass this signal. the transcriptional antitermination control by junín virus nucleocapsid protein n, has been demonstrated in vivo by infecting bhk-21 cells expressing this viral protein in the presence of translation inhibitors. this is t ... | 2001 | 11163643 |
| involvement of vacuolar proton atpase in junin virus multiplication. | the role of vacuolar-proton atpase (v-h+ atpase) on junin virus (jv) replication was evaluated by analyzing the effect of specific inhibitors of the enzyme activity on different steps of virus multiplication cycle. the presence of the macrolide antibiotics bafilomycin a1 and concanamycin a during the first two hours of infection caused a significant reduction of extracellular infectious virus production and viral protein expression in vero and bhk-21 cells. the inhibitory action of the compounds ... | 2001 | 11315636 |
| effect of fatty acids on arenavirus replication: inhibition of virus production by lauric acid. | to study the functional involvement of cellular membrane properties on arenavirus infection, saturated fatty acids of variable chain length (c10-c18) were evaluated for their inhibitory activity against the multiplication of junin virus (junv). the most active inhibitor was lauric acid (c12), which reduced virus yields of several attenuated and pathogenic strains of junv in a dose dependent manner, without affecting cell viability. fatty acids with shorter or longer chain length had a reduced or ... | 2001 | 11402863 |
| [neutralization test for lymphocytic choriomeningitis virus for distinguishing between two arenavirus infections in argentina]. | the active coexistence of two pathogenic arenaviruses, junin (junv) and lymphocytic choriomeningitis (lcmv), in the same region of argentina, has been known since the early 70's, and records of clinical and subclinical human infections by one and/or the other agent have been continuously produced for the last 25 years. anti-lcmv antibody is currently searched only by indirect immunofluorescence, a test that shows cross reactions among a number of arenaviruses yielding, in the cases of lcmv and j ... | 2001 | 11833256 |
| evaluation of an enzyme-linked immunosorbent assay for detection of antibodies to junin virus in rodents. | junin virus is the etiological agent of argentine hemorrhagic fever, a serious rodent-borne disease. an enzyme-linked immunosorbent assay (elisa) to detect junin virus igg antibodies in rodents was evaluated using sera from 27 calomys musculinus and five calomys laucha, inoculated experimentally with a live attenuated strain of this arenavirus. the test performance was compared against an indirect immunofluorescence assay (ifa). the elisa had a sensitivity and specificity of 100% and a reproduci ... | 2002 | 11906733 |
| evaluation of an enzyme-linked immunosorbent assay for detection of antibodies to junin virus in rodents. | junin virus is the etiological agent of argentine hemorrhagic fever, a serious rodent-borne disease. an enzyme-linked immunosorbent assay (elisa) to detect junin virus igg antibodies in rodents was evaluated using sera from 27 calomys musculinus and five calomys laucha, inoculated experimentally with a live attenuated strain of this arenavirus. the test performance was compared against an indirect immunofluorescence assay (ifa). the elisa had a sensitivity and specificity of 100% and a reproduci ... | 2002 | 11906733 |
| evaluation of the antiviral activity against junin virus of macrocyclic trichothecenes produced by the hypocrealean epibiont of baccharis coridifolia. | four macrocyclic trichothecenes, roridin a, roridin e, verrucarin a and verrucarin j, produced by the hypocrealean epibiont of baccharis coridifolia, were evaluated for their inhibitory activity against the arenavirus junin (junv), the etiological agent of argentine hemorrhagic fever. the trichothecenes achieved a dose-dependent inhibition of junv multiplication at concentrations not affecting cell viability. the 50 % inhibitory concentration (ic50) values determined by a virus yield inhibition ... | 2002 | 11914955 |
| junin virus vaccines. | | 2002 | 11987817 |
| gene flow among calomys musculinus (rodentia, muridae) populations in argentina. | calomys musculinus is a sigmodontinae rodent inhabiting periodically disturbed habitats in the central eastern plains of argentina. it is the natural reservoir host of junin virus, the etiological agent of argentine hemorrhagic fever (ahf). in order to analyze the levels of gene flow among populations of this species, allozymic variability at 26 loci was studied in 291 individuals from the endemic zone of ahf and localities outside it. all populations showed high levels of polymorphism (he betwe ... | 2002 | 11990761 |
| gene flow among calomys musculinus (rodentia, muridae) populations in argentina. | calomys musculinus is a sigmodontinae rodent inhabiting periodically disturbed habitats in the central eastern plains of argentina. it is the natural reservoir host of junin virus, the etiological agent of argentine hemorrhagic fever (ahf). in order to analyze the levels of gene flow among populations of this species, allozymic variability at 26 loci was studied in 291 individuals from the endemic zone of ahf and localities outside it. all populations showed high levels of polymorphism (he betwe ... | 2002 | 11990761 |
| inheritance of random amplified polymorphic dna (rapd-pcr) markers and their use in population genetic studies of calomys musculinus (rodentia, muridae), the reservoir of argentine hemorrhagic fever. | in order to assess the reliability of rapd markers in the estimation of the genetic structure of natural populations of the murid rodent calomys musculinus (reservoir of junin virus, ethiological agent of argentine hemorrhagic fever), we have analyzed the heritability of rapd bands in 10 parents and their offspring (33 individuals). fourteen out of a total of 119 bands obtained were absent in the parental patterns, but consistently amplified in offspring from some families. these bands can be el ... | 2001 | 12035619 |
| inheritance of random amplified polymorphic dna (rapd-pcr) markers and their use in population genetic studies of calomys musculinus (rodentia, muridae), the reservoir of argentine hemorrhagic fever. | in order to assess the reliability of rapd markers in the estimation of the genetic structure of natural populations of the murid rodent calomys musculinus (reservoir of junin virus, ethiological agent of argentine hemorrhagic fever), we have analyzed the heritability of rapd bands in 10 parents and their offspring (33 individuals). fourteen out of a total of 119 bands obtained were absent in the parental patterns, but consistently amplified in offspring from some families. these bands can be el ... | 2001 | 12035619 |
| synthesis and expression of viral antigens in vero cells persistently infected with junin virus. | two vero cell lines persistently infected with xjcl3 and cl67 strains of junin virus and named v3 and v7, respectively, have been characterized with respect to the presence and expression of the nucleoprotein (n) and the glycoprotein precursor (gpc) viral genes. after the acute phase of infection, where a marked cpe and high titers of virus were obtained, jv persistently infected cells became morphologically undistinguishable from vero cells and virus production dropped to undetectable levels. v ... | 2002 | 12181674 |
| mode of inactivation of arenaviruses by disulfide-based compounds. | several disulfide-based compounds, including intermolecular aromatic disulfides of the type ph-s-s-ph and dithianes with the sulfur atoms tethered in a ring structure, have shown effective inhibitory activity against the arenaviruses junin (junv), agent of argentine hemorrhagic fever, and tacaribe (tcrv). these compounds showed a strong virucidal effect with inactivating concentration 50% (ic(50)) values in the range 0.6-5.0 microm, and also were effective to reduce virus yields from infected ce ... | 2002 | 12206881 |
| junin virus-induced astrocytosis is impaired by inos inhibition. | because junin virus (jv) experimental encephalitis of mice and rats is characterized by mild histopathological changes that do not seem to justify per se lethality after intracerebral infection, such a murine model seems adequate to investigate the potential role of inducible nitric oxide synthase (inos) as a pathogenic factor. concomitant with a predominant astrocyte reaction, increased immunoperoxidase expression of inos, mitochondrial superoxide dismutase (sodm) and glutathione peroxidase (gp ... | 2003 | 12436490 |
| polysulfonates derived from metal thiolate complexes as inhibitors of hiv-1 and various other enveloped viruses in vitro. | sodium 2-mercaptoethanesulfonate reacts with the metal ions pd(ii), pt(ii), ag(i), cd(ii) and zn(ii) to yield complexes containing multiple anionic sulfonate sites. on the basis of spectroscopic and other analytical data the complexes were assigned the tentative molecular formulas: pd6(sch2ch2so3na)12, ptn(sch2ch2so3na)2n+2, agn(sch2ch2so3na)n, na2zn4(sch2ch2so3na)10, and na2cd4(sch2ch2so3na)10. the complexes displayed a variety of differences in activity towards dna and rna viruses. the platinu ... | 2002 | 12448691 |
| igg subclasses in human immune response to wild and attenuated (vaccine) junin virus infection. | different proportions of igg subclasses have previously been reported to distinguish the immune response elicited by primary and recurrent viral infections, as well as viral vaccines. the goal of this study was to study the igg subclasses composition in the immune response of patients with argentine hemorrhagic fever, and vaccinees with candid #1 strain of junin virus. twenty-four individuals inoculated with candid #1 vaccine and 67 patients with argentine hemorrhagic fever were studied. blood s ... | 2003 | 12526057 |
| arenaviruses other than lassa virus. | the family arenaviridae includes 23 viral species, of which 5 can cause viral hemorrhagic fevers with a case fatality rate of about 20%. these five viruses are junin, machupo, guanarito, sabia and lassa virus, the manipulation of which requires biosafety level 4 facilities. they are included in the category a pathogen list established by the center for disease control and prevention that groups agents with the greatest potential for adverse public health impact and mass casualties whether a situ ... | 2003 | 12615305 |
| differential inhibitory action of two azoic compounds against arenaviruses. | the action of five azo-based compounds against the arenaviruses junin (junv) and tacaribe (tcrv) was evaluated in vitro by a virus yield inhibition assay in vero cells and a cell-free virion inactivation assay. the compound 2-azo-(1'-(2'-nitroso)naphthyl)-benzoate (annb) was the most effective inhibitor of arenavirus production in vero cells with ec(50) (effective concentration 50%) values in the range 6.5-26.2 microm and without inactivating properties. by contrast, the azodicarbonamide (ada) w ... | 2003 | 12672577 |
| inactivation of s-adenosyl-l-homocysteine hydrolase with novel 5'-thioadenosine derivatives. antiviral effects. | synthesis of 5'-s-vinyl-5'-thioadenosine 5, 5'-s-ethynyl-5'-thioadenosine 7 and 5'-s-cyano-5'-thioadenosine 9 is described. incubation of adohcy hydrolase with 5, 7 and 9 resulted in time- and concentration-dependent inactivation of the enzyme and partial depletion of its nad(+) content. from these results and characterisation of metabolites released during the inactivation process, hypothetical mechanisms are suggested. the antiviral activity of 5, 7 and 9 was examined. significant activities w ... | 2003 | 12729633 |
| inhibitory effect of thiosemicarbazone derivatives on junin virus replication in vitro. | the inhibitory effect of several thiosemicarbazones (tscs), synthesized from aromatic ketones and terpenones, and their heterocyclic thiadiazoline (tdz) derivatives, was investigated against junin virus (junv), an arenavirus agent of argentine haemorrhagic fever. from the 25 compounds tested, six compounds belonging to the tsc group were found to be selective inhibitors of junv, with ec50 values determined by a virus yield inhibition assay in the range 3.4-12.5 microm, and selectivity indices gr ... | 2003 | 12856921 |
| endothelial cell function alteration after junin virus infection. | hematologic involvement is the main feature of argentine hemorrhagic fever (ahf), an endemo-epidemic disease caused by junin virus (jv). since endothelial dysfunction could play a role in ahf-altered hemostasis, we studied human umbilical vein endothelial cell (huvec) infection with a virulent (jvv) and a non-virulent (jva) jv strain. cells were infected by the two jv variants with no detectable apoptosis or cytopathic effect. both viral variants up-regulated icam-1 and vcam-1 levels, while von ... | 2003 | 12888881 |
| long-lasting astrocyte reaction to persistent junin virus infection of rat cortical neurons. | immunoperoxidase labeling was performed in histological sections from rat brain harvested during acute (10-30 days), clinically inapparent (90-270 days) and late (450-540 days) stages of junin virus-induced neurological disease. in frontoparietal cortex, count of viral antigen (+) neurons peaked during the acute period (27.7+/-6.8), dropped within the intermediate (4.8+/-4.0 to 1.4+/-1.1) and increased (7.6+/-4.3) at the onset of the late neurological syndrome. in infected vs. control rats, the ... | 2003 | 12898341 |
| propagation of junin virus, the etiological agent of argentinian hemorrhagic fever, in hela cell cultures. | | 1961 | 13769887 |
| [experimental hemorrhagic fever in the guinea pig (junin virus)]. | | 1961 | 13872119 |
| [experimental hemorrhagic fever in the guinea pig (junin virus)]. | | 1961 | 13872119 |
| [experimental hemorrhagic fever in the guinea pig induced by the junin virus]. | | 1963 | 14117805 |
| [experimental hemorrhagic fever in the guinea pig induced by the junin virus]. | | 1963 | 14117805 |
| [laboratory evidence of the activity of junin virus in the southeast of cordoba: hypothesis on its epidemiology]. | | 1964 | 14144586 |
| [immunization of guinea pigs against the junin virus by inoculation with tacaribe virus]. | | 1964 | 14168726 |
| [immunization of guinea pigs against the junin virus by inoculation with tacaribe virus]. | | 1964 | 14168726 |
| protection against junin virus by immunization with live tacaribe virus. | | 1965 | 14328956 |
| protection against junin virus by immunization with live tacaribe virus. | | 1965 | 14328956 |
| [isolation of the junin virus (epidemic hemorrhagic fever) from the mites of the epidemic area (echinolaelaps echidninus, barlese)]. | | 1959 | 14430571 |
| [isolation of the junin virus from rodents of non-epidemic areas]. | | 1961 | 14484008 |
| studies with the etiologic agent of argentinian epidemic hemorrhagic fever (junin virus). | | 1962 | 14490371 |
| intermediate filament integrity is required for junin virus replication. | the role of the cytoskeletal framework in junin virus (junv) replication has already been demonstrated with compounds interfering with the microfilament (mf) and microtubule (mt) networks. in this work, we evaluated the role of intermediate filaments (if) during junv infection. we tested the effect of acrylamide, a compound that selectively disrupts if, in culture of three different cell types: vero cells, murine astrocytes and human foreskin fibroblasts. perturbation of intermediate filaments h ... | 2003 | 14550587 |
| virucidal activity of essential oils from aromatic plants of san luis, argentina. | essential oils obtained from eight aromatic plants of san luis province, argentina, were screened for virucidal activity against herpes simplex virus type 1 (hsv-1), junin virus (junv) and dengue virus type 2 (den-2). the most potent inhibition was observed with the essential oil of lippia junelliana and lippia turbinata against junv with virucidal concentration 50% (vc(50)) values in the range 14-20 ppm, whereas aloysia gratissima, heterotheca latifolia and tessaria absinthioides inhibited junv ... | 2003 | 14595590 |
| restricted gene flow in calomys musculinus (rodentia, muridae), the natural reservoir of junin virus. | random amplified polymorphic dna polymerase chain reaction (rapd-pcr) markers were used to evaluate the relative contribution of gene flow as a determinant of the population genetic structure of the wild rodent calomys musculinus (the reservoir of argentine hemorrhagic fever [ahf]) in central argentina. one hundred eighty-seven individuals from 13 populations (9 of them from the endemic zone of ahf and 5 from areas outside it) were analyzed using 78 polymorphic rapd loci. genetic variation withi ... | 2003 | 14691315 |
| restricted gene flow in calomys musculinus (rodentia, muridae), the natural reservoir of junin virus. | random amplified polymorphic dna polymerase chain reaction (rapd-pcr) markers were used to evaluate the relative contribution of gene flow as a determinant of the population genetic structure of the wild rodent calomys musculinus (the reservoir of argentine hemorrhagic fever [ahf]) in central argentina. one hundred eighty-seven individuals from 13 populations (9 of them from the endemic zone of ahf and 5 from areas outside it) were analyzed using 78 polymorphic rapd loci. genetic variation withi ... | 2003 | 14691315 |
| resistance to superinfection of vero cells persistently infected with junin virus. | two non-virogenic vero cell lines persistently infected with the arenavirus junin (junv), named v3 and v7, were characterized with respect to their resistance to superinfection with homologous and antigenically related viruses. both lines were refractory to junv multiplication and partially resistant to other arenaviruses. junv was able to adsorb and penetrate persistently infected cells and, although v3 and v7 were able to support synthesis of antigenomic sense viral rna, protein production of ... | 2004 | 14991440 |
| antiviral activity of antimicrobial cationic peptides against junin virus and herpes simplex virus. | the in vitro antiviral activity of antimicrobial cationic peptides: cecropin a, melittin, magainin i and ii and indolicidin against the arenavirus junin virus (jv), and herpes simplex virus type 1 (hsv-1) and 2 (hsv-2) was evaluated. cecropin a effectively inhibited jv multiplication and failed to affect hsv replication whereas melittin impeded the multiplication of jv and hsv, but was highly toxic for the host cell. magainins i and ii exhibited inhibitory action toward hsv-1 and hsv-2 but were ... | 2004 | 15081088 |
| [pathology of persistent infection of calomys musculinus with an attenuated strain junin virus]. | | 1982 | 15170951 |
| [pathology of persistent infection of calomys musculinus with an attenuated strain junin virus]. | | 1982 | 15170951 |
| [effect of intracerebral inoculation of junin virus in guinea pigs]. | | 1982 | 15170953 |
| [effect of intracerebral inoculation of junin virus in guinea pigs]. | | 1982 | 15170953 |
| [effect of treatment with immune sera in rats infected with junin virus]. | | 1982 | 15170960 |
| recent range expansion and low levels of contemporary gene flow in calomys musculinus: its relationship with the emergence and spread of argentine haemorrhagic fever. | the geographic distribution of haplotype diversity in the rodent calomys musculinus, sampled from 16 wild populations of argentina, was analysed on two geographical scales. the species is the natural reservoir of the junin virus, the etiological agent of the argentine haemorrhagic fever (ahf). in all, 24 composite haplotypes were recognised in the mtdna d-loop region. haplotypes 1 and 2, internal in the network, were the most frequent and were present in almost all populations. the absence of la ... | 2004 | 15316554 |
| recent range expansion and low levels of contemporary gene flow in calomys musculinus: its relationship with the emergence and spread of argentine haemorrhagic fever. | the geographic distribution of haplotype diversity in the rodent calomys musculinus, sampled from 16 wild populations of argentina, was analysed on two geographical scales. the species is the natural reservoir of the junin virus, the etiological agent of the argentine haemorrhagic fever (ahf). in all, 24 composite haplotypes were recognised in the mtdna d-loop region. haplotypes 1 and 2, internal in the network, were the most frequent and were present in almost all populations. the absence of la ... | 2004 | 15316554 |
| the signal peptide of the junín arenavirus envelope glycoprotein is myristoylated and forms an essential subunit of the mature g1-g2 complex. | arenaviruses comprise a diverse family of rodent-borne viruses that are responsible for recurring and emerging outbreaks of viral hemorrhagic fevers worldwide. the junín virus, a member of the new world arenaviruses, is endemic to the pampas grasslands of argentina and is the etiologic agent of argentine hemorrhagic fever. in this study, we have analyzed the assembly and function of the junín virus envelope glycoproteins. the mature envelope glycoprotein complex is proteolytically processed from ... | 2004 | 15367645 |
| inhibition of cell fusion in junin virus-infected cells by sera from argentine hemorrhagic fever patients. | junin virus (jv), a member of the arenaviridae family, is the etiological agent of argentine hemorrhagic fever (ahf). a low ph-pulse, induces fusion of vero cells infected with jv to form syncytia, whose production can be inhibited by neutralizing antibodies against the jv major glycoprotein. | 2005 | 15780806 |
| polarized entry and release of junin virus, a new world arenavirus. | junin virus (junv), the causative agent of argentine haemorrhagic fever, is a human pathogen that naturally enters the body through the epithelial cells of the respiratory and digestive tracts. the interaction of junv with two types of polarized epithelial cultures, vero c1008 and a549, was investigated. radioactive virus-binding assays showed that junv infects polarized lines preferentially through the apical surface. high-level expression of viral nucleoprotein was detected in polarized cell l ... | 2005 | 15831960 |
| evaluation of chemical and antiviral properties of essential oils from south american plants. | the essential oils of seven aromatic plants from córdoba, san luis and san juan provinces (argentina) were isolated by steam distillation and analysed by a gas chromatography/mass spectrometry technique. the oils were screened for cytotoxicity and in vitro inhibitory activity against herpes simplex virus type 1 (hsv-1), dengue virus type 2 (denv-2) and junin virus (junv) by a virucidal test. the oils showed a variable virucidal action according to the virus. the better relationship between cytot ... | 2005 | 16130522 |
| genetic analysis of heptad-repeat regions in the g2 fusion subunit of the junín arenavirus envelope glycoprotein. | the g2 fusion subunit of the junín virus envelope glycoprotein gp-c contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of class i viral fusion proteins. we have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. all the mutant glycoproteins were expressed and transported t ... | 2005 | 16169032 |
| antiviral mode of action of a synthetic brassinosteroid against junin virus replication. | the antiviral mode of action of the synthetic brassinosteroid (22s,23s)-3beta-bromo-5alpha,22,23-trihydroxystigmastan-6-one (6b) against junin virus replication in vero cells was investigated. time-related experiments showed that 6b mainly affects an early event of virus growth cycle. neither adsorption nor internalization of viral particles was the target of the inhibitory action. the analysis of the effect of 6b on viral rna synthesis demonstrated that the presence of the compound adversely af ... | 2005 | 16171877 |
| [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 ... | 2005 | 16193711 |
| [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 ... | 2005 | 16193711 |
| identification and characterization of potent small molecule inhibitor of hemorrhagic fever new world arenaviruses. | category a arenaviruses as defined by the national institute of allergy and infectious diseases (niaid) are human pathogens that could be weaponized by bioterrorists. many of these deadly viruses require biosafety level-4 (bsl-4) containment for all laboratory work, which limits traditional laboratory high-throughput screening (hts) for identification of small molecule inhibitors. for those reasons, a related bsl-2 new world arenavirus, tacaribe virus, 67-78% identical to junín virus at the amin ... | 2006 | 16343651 |
| genomic features of attenuated junín virus vaccine strain candidate. | junin virus strain candid #1 was developed as a live attenuated vaccine for argentine haemorrhagic fever. in this paper, we report the nucleotide sequences of l rna of candid #1 and examine the relationship to its more virulent ancestors junin virus xj#44 and xj 13 (prototype) and other closely and distantly related arenaviruses. comparisons of the nucleotide and amino acid sequences of l and z genes of candid #1 and its progenitor strains revealed twelve point mutations in the l polypeptide tha ... | 2006 | 16525733 |
| characterization of the cellular receptors for the south american hemorrhagic fever viruses junin, guanarito, and machupo. | the new world arenaviruses junin, machupo, and guanarito are the causative agents of hemorrhagic fevers (hf) with high mortality in humans. the cellular receptor for old world arenaviruses and one subgroup of the new world arenaviruses (clade c) have been identified as alpha-dystroglycan (alpha-dg). in contrast, the receptor(s) of the south american hf viruses, which belong to the clade b new world arenaviruses, are currently unknown. to begin to characterize the cellular receptors used by these ... | 2006 | 16574183 |
| role of the stable signal peptide and cytoplasmic domain of g2 in regulating intracellular transport of the junín virus envelope glycoprotein complex. | enveloped viruses utilize the membranous compartments of the host cell for the assembly and budding of new virion particles. in this report, we have investigated the biogenesis and trafficking of the envelope glycoprotein (gp-c) of the junín arenavirus. the mature gp-c complex is unusual in that it retains a stable signal peptide (ssp) as an essential component in association with the typical receptor-binding (g1) and transmembrane fusion (g2) subunits. we demonstrate that, in the absence of ssp ... | 2006 | 16698999 |
| receptor use by pathogenic arenaviruses. | the arenavirus family contains several important human pathogens including lassa fever virus (lasv), lymphocytic choriomeningitis virus (lcmv) and the new world clade b viruses junin (junv) and machupo (macv). previously, alpha-dystroglycan (alpha-dg) was identified as a receptor recognized by lasv and certain strains of lcmv. however, other studies have suggested that alpha-dg is probably not used by the clade b viruses, and the receptor(s) for these pathogens is currently unknown. using pseudo ... | 2006 | 16797051 |
| immune response to vaccination against argentine hemorrhagic fever in an area where different arenaviruses coexist. | neutralizing antibody (nt ab) titers to candid #1 (c#1) vaccine against argentine hemorrhagic fever were studied for 2 years post-vaccination in 330 volunteers, to assess whether the kinetics and/or magnitude of this immune response is modified by previous infection with the arena viruses junin (jun) and lymphocytic choriomeningitis (lcm). a total of 160 volunteers received c#1, distributed as follows: without detectable pre-infection with arenaviruses (n = 54); with pre-existing antibodies to j ... | 2006 | 16817762 |
| role of the stable signal peptide of junín arenavirus envelope glycoprotein in ph-dependent membrane fusion. | the envelope glycoprotein of the arenaviruses (gp-c) is unusual in that the mature complex retains the cleaved, 58-amino-acid signal peptide. association of this stable signal peptide (ssp) has been shown to be essential for intracellular trafficking and proteolytic maturation of the gp-c complex. we identify here a specific and previously unrecognized role of ssp in ph-dependent membrane fusion. amino acid substitutions that alter the positive charge at lysine k33 in ssp affect the ability of g ... | 2006 | 16840359 |
| distinct requirements for signal peptidase processing and function in the stable signal peptide subunit of the junín virus envelope glycoprotein. | the arenavirus envelope glycoprotein (gp-c) retains a cleaved and stable signal peptide (ssp) as an essential subunit of the mature complex. this 58-amino-acid residue peptide serves as a signal sequence and is additionally required to enable transit of the assembled gp-c complex to the golgi, and for ph-dependent membrane fusion activity. we have investigated the c-terminal region of the junín virus ssp to study the role of the cellular signal peptidase (spase) in generating ssp. site-directed ... | 2007 | 17045626 |
| bitopic membrane topology of the stable signal peptide in the tripartite junín virus gp-c envelope glycoprotein complex. | the stable signal peptide (ssp) of the gp-c envelope glycoprotein of the junín arenavirus plays a critical role in trafficking of the gp-c complex to the cell surface and in its membrane fusion activity. ssp therefore may function on both sides of the lipid membrane. in this study, we have investigated the membrane topology of ssp by confocal microscopy of cells treated with the detergent digitonin to selectively permeabilize the plasma membrane. by using an affinity tag to mark the termini of s ... | 2007 | 17267481 |
| transferrin receptor 1 is a cellular receptor for new world haemorrhagic fever arenaviruses. | at least five arenaviruses cause viral haemorrhagic fevers in humans. lassa virus, an old world arenavirus, uses the cellular receptor alpha-dystroglycan to infect cells. machupo, guanarito, junin and sabia viruses are new world haemorrhagic fever viruses that do not use alpha-dystroglycan. here we show a specific, high-affinity association between transferrin receptor 1 (tfr1) and the entry glycoprotein (gp) of machupo virus. expression of human tfr1, but not human transferrin receptor 2, in ha ... | 2007 | 17287727 |
| differences in tropism and ph dependence for glycoproteins from the clade b1 arenaviruses: implications for receptor usage and pathogenicity. | the clade b lineage of the new world arenaviruses contains four viruses capable of causing severe hemorrhagic fevers in humans. within this group, the b1 sub-lineage contains the pathogenic viruses junin (junv) and machupo (macv), as well as the non-pathogenic tacaribe virus (tcrv). in order to elucidate differences that may determine pathogenicity, we studied the entry pathways directed by the glycoproteins (gps) from these related b1 viruses, using pseudotyped retroviral vectors and gp1 immuno ... | 2007 | 17397892 |
| [ballistocardiographic changes in argentinian hemorrhagic viral disease]. | among eleven convalescent patients of argentine hemorragic fever an electro-ballistocardiographic study was effected which led to the following conclusions: a) in 2 over 11 studied cases, electro-ballistocardiographic modifications of probable myocardial injury could be detected. b) the greatest percentage of the modifications was interpreted as normal variants of the electrocardiogram. | 1965 | 17424677 |
| characterization of junin arenavirus cell entry. | junín virus (junv) entry is conducted by receptor-mediated endocytosis. to explore the cellular entry mechanism of junv, inhibitory effects of drugs affecting the main endocytic pathways on junv entry into vero cells were analysed. compounds that impair clathrin-mediated endocytosis were shown to reduce virus internalization without affecting virion binding. in contrast, drugs that alter lipid-raft microdomains, impairing caveola-mediated endocytosis, were not able to block virus entry. to show ... | 2007 | 17485539 |
| development of recombinant nucleoprotein-based diagnostic systems for lassa fever. | diagnostic systems for lassa fever (lf), a viral hemorrhagic fever caused by lassa virus (lasv), such as enzyme immunoassays for the detection of lasv antibodies and lasv antigens, were developed using the recombinant nucleoprotein (rnp) of lasv (lasv-rnp). the lasv-rnp was expressed in a recombinant baculovirus system. lasv-rnp was used as an antigen in the detection of lasv-antibodies and as an immunogen for the production of monoclonal antibodies. the lasv-rnp was also expressed in hela cells ... | 2007 | 17634509 |
| superinfection exclusion in bhk-21 cells persistently infected with junín virus. | we characterized a persistently junín virus (junv)-infected bhk-21 cell line obtained by experimental infection with the xjcl3 strain. this cell line, named k3, produced low levels of virus in supernatants which were not influenced by the presence of defective interfering (di) particles after the first year of infection. k3 cells were able to exclude superinfection of the homologous junv and the antigenically related tacaribe virus (tcrv), whereas the non-related arenaviruses lymphocytic choriom ... | 2007 | 17872526 |
| a novel zinc-binding domain is essential for formation of the functional junín virus envelope glycoprotein complex. | the envelope glycoprotein of the junín arenavirus (gp-c) mediates entry into target cells through a ph-dependent membrane fusion mechanism. unlike other class i viral fusion proteins, the mature gp-c complex retains a cleaved, 58-amino-acid signal peptide (ssp) as an essential subunit, required both for trafficking of gp-c to the cell surface and for the activation of membrane fusion. ssp has been shown to associate noncovalently in gp-c via the cytoplasmic domain (ctd) of the transmembrane fusi ... | 2007 | 17928348 |
| cellular entry of lymphocytic choriomeningitis virus. | in contrast to most enveloped viruses that enter the host cell via clathrin-dependent endocytosis, the old world arenavirus lymphocytic choriomeningitis virus (lcmv) enters cells via noncoated vesicles that deliver the virus to endosomes, where ph-dependent membrane fusion occurs. here, we investigated the initial steps of lcmv infection. we found that the attachment of lcmv to its cellular receptor alpha-dystroglycan occurs rapidly and is not dependent on membrane cholesterol. however, subseque ... | 2008 | 18045945 |
| treatment of argentine hemorrhagic fever. | argentine hemorrhagic fever (ahf) is a rodent-borne illness caused by the arenavirus junin that is endemic to the humid pampas of argentina. ahf has had significant morbidity since its emergence in the 1950s, with a case-fatality rate of the illness without treatment between 15% and 30%. the use of a live attenuated vaccine has markedly reduced the incidence of ahf. present specific therapy involves the transfusion of immune plasma in defined doses of neutralizing antibodies during the prodromal ... | 2008 | 18054395 |
| cell entry by human pathogenic arenaviruses. | the arenaviruses lassa virus (lasv) in africa and machupo (macv), guanarito (gtov) and junin viruses (junv) in south america cause severe haemorrhagic fevers in humans with fatality rates of 15-35%. the present review focuses on the first steps of infection with human pathogenic arenaviruses, the interaction with their cellular receptor molecules and subsequent entry into the host cell. while similarities exist in genomic organization, structure and clinical disease caused by pathogenic old worl ... | 2008 | 18182084 |
| receptor determinants of zoonotic transmission of new world hemorrhagic fever arenaviruses. | transferrin receptor 1 (tfr1) is a cellular receptor for the new world hemorrhagic fever arenaviruses machupo (macv), junín (junv), and guanarito (gtov). each of these viruses is specifically adapted to a distinct rodent host species, but all cause human disease. here we compare the ability of these viruses to use various mammalian transferrin receptor 1 (tfr1) orthologs, including those of the south american rodents that serve as reservoirs for macv, junv, and gtov (calomys callosus, calomys mu ... | 2008 | 18268337 |
| site 1 protease is required for proteolytic processing of the glycoproteins of the south american hemorrhagic fever viruses junin, machupo, and guanarito. | the cellular proprotein convertase site 1 protease (s1p) has been implicated in the proteolytic processing of the glycoproteins (gps) of old world arenaviruses. here we report that s1p is also involved in the processing of the gps of the genetically more-distant south american hemorrhagic fever viruses guanarito, machupo, and junin. efficient cleavage of guanarito virus gp, whose protease recognition sites deviate from the reported s1p consensus sequence, indicates a broader specificity of s1p t ... | 2008 | 18400865 |
| basolateral entry and release of new and old world arenaviruses from human airway epithelia. | transmission of arenaviruses from rodent hosts to humans is generally thought to occur through inhalation or ingestion of dust or droplets containing viral particles. here we demonstrate that two identified arenavirus receptors, alpha-dystroglycan (alpha-dg) and transferrin receptor 1 (tfr1), are expressed in polarized human airway epithelia. lymphocytic choriomeningitis virus strains with high or low alpha-dg affinity and junin virus, which binds tfr1, efficiently infected polarized epithelia o ... | 2008 | 18417570 |
| dehydroepiandrosterone, epiandrosterone and synthetic derivatives inhibit junin virus replication in vitro. | in the present paper the in vitro antiviral activity of dehydroepiandrosterone (dhea), epiandrosterone (ea) and 16 synthetic derivatives against junin virus (junv) replication in vero cells was studied. dhea and ea caused a selective inhibition of the replication of junv and other members of the arenaviridae family such as pichinde virus and tacaribe virus. the compounds were not virucidal to cell-free junv. the impairment of viral replication was not due to an inhibitory effect of the steroids ... | 2008 | 18462821 |
| different mechanisms of cell entry by human-pathogenic old world and new world arenaviruses. | the old world arenavirus lassa virus (lasv) is the causative agent of severe viral hemorrhagic fever (vhf) in humans and is the most prevalent human pathogen among arenaviruses. the present study investigated the largely unknown mechanisms of cell entry of lasv, a process know to be mediated solely by the virus envelope glycoprotein (gp). to circumvent biosafety restrictions associated with the use of live lasv, we used reverse genetics to generate a recombinant variant of the prototypic arenavi ... | 2008 | 18508885 |
| synthesis and evaluation of n-substituted acridones as antiviral agents against haemorrhagic fever viruses. | in the present study, a series of n-substituted acridone derivatives was synthesized and evaluated against two haemorrhagic fever viruses (hfv). | 2008 | 18610557 |
| 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 ... | 2008 | 18689636 |