Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| analyses of the genomes of prototype pichinde arenavirus and a virulent derivative of pichinde munchique: evidence for sequence conservation at the 3' termini of their viral rna species. | 1982 | 6278715 | |
| pathogenesis of a pichinde virus strain adapted to produce lethal infections in guinea pigs. | a model for studying the pathogenesis of virulent arenavirus infection was developed by adapting pichinde virus to produce lethal infections of inbred guinea pigs. this adapted pichinde virus retained low virulence for primates, thus potentially reducing the biohazard to investigators. whereas all inbred (strain 13) guinea pigs were infected and killed by 3 plaque-forming units or more of adapted pichinde virus injected subcutaneously, outbred (hartley strain) guinea pigs were relatively resista ... | 1981 | 6265367 |
| characterization of polypeptides immunoprecipitable from pichinde virus-infected bhk-21 cells. | using hamster anti-pichinde virus serum, we immunoprecipitated polypeptides from bhk-21 cells infected with pichinde virus. seven immunoprecipitable polypeptides exhibited a time- and multiplicity of infection-dependent appearance when the cultures were pulse-labeled with l-[35s]methionine for 1 h. the predominant polypeptide was a nucleoprotein (np) of 64,000 daltons. components of 48,000, 38,000, and 28,000 daltons, when analyzed by two-dimensional tryptic peptide mapping, were found to be der ... | 1981 | 6264158 |
| role of natural killer cells in pichinde virus infection of syrian hamsters. | pichinde virus produced a fatal infection in adult mha hamsters but not lsh hamsters after intraperitoneal inoculation. after footpad inoculation, an 8-day swelling response was observed in lsh but not mha hamsters; however, both strains survived infection by this route. examination of the kinetics of viral replication in the two hamster strains inoculated by the two routes revealed a correlation between infectious centers and natural killer activity in cells obtained from spleens and popliteal ... | 1981 | 6262252 |
| susceptibility to fatal pichinde virus infection in the syrian hamster. | the data presented in this paper suggest that the susceptible mha hamster strain possesses a spleen target cell for pichinde virus replication which is minimally expressed in the resistant strain. this target cell co-purifies with cells mediating nk activity, raising the possibility that the nk cell itself may be the additional target cell for pichinde virus replication in the susceptible hamster strain. we hypothesize that early virus replication in the spleens of ip-inoculated hamsters leads t ... | 1981 | 6261541 |
| immune recognition of tumor cells in mice infected with pichinde virus. | pichinde virus (pv), a member of the arenaviridae family, protects mice from a lethal inoculation with the sarcoma 180 (s180) tumor cell line. virus replication, which is required for protection, occurs primarily in the spleen and tumor. during the first 4 days, elevated natural killer (nk) cell activity parallels an increase in serum interferon in pv-infected mice. on day 7 after infection virus-specific cytotoxic t cells (ctls) are found in the mouse. this strong response peaks on day 13 and g ... | 1984 | 6203637 |
| pichinde virus-specific cell-associated suppression of primary footpad swelling in an inbred strain of syrian hamsters. | pichinde virus causes a lethal disease after i.p. inoculation of adult mha hamsters; other strains of syrian hamsters are resistant to this lethal infection. during studies of cell-mediated immune responses to pichinde virus, it was noted that mha hamsters survived infection when the virus was given in the footpad. however, unlike the resistant lsh and lvg strains of hamsters, the mha hamsters did not manifest a footpad swelling response. failure of the mha hamster to respond to a footpad inocul ... | 1983 | 6184408 |
| characterization studies of the pichinde virus-a member of the arenavirus group. | 1971 | 5544511 | |
| pichindé virus, a new virus of the tacaribe group from colombia. | 1971 | 4998616 | |
| serological evidence of infection by pichinde virus among laboratory workers. | a total of 44 laboratory workers were examined for serological evidence of infection by pichinde virus. complement-fixing antibodies were detected in the sera of 6 of 13 (46%) persons working with the virus but not among 31 persons not working with the virus. serological evidence of infection was greatest among those workers exposed to concentrated virus. no distinct illness could be associated with the infection. | 1974 | 4856825 |
| characterization of nucleic acid of pichinde virus. | the nucleic acid of pichinde virus was found to be single-stranded ribonucleic acid (rna) as determined by sensitivity to ribonuclease, by alkaline degradation, by buoyant density in cesium sulfate, and by analysis of the base composition. the rna of the virion could be separated into five components which had sedimentation coefficients corresponding to 31s, 28s, 22s, 18s and 4 to 6s. the 28s, 18s, and possibly the 4 to 6s rnas appear to be derived from host cell components incorporated into the ... | 1973 | 4734321 |
| structural proteins of pichinde virus. | pichinde virus, a member of the arenovirus group, was found to have four polypeptides by polyacrylamide gel electrophoresis. two components, v(i) and v(ii), had molecular weights of about 72,000, whereas v(iii) had a molecular weight of 34,000. a minor component, v(iv), had a molecular weight of about 12,000. glucosamine was incorporated into v(ii) and v(iii), suggesting that these components were glycopeptides whereas v(i) and v(iv) were polypeptides. treatment of the virus with nonidet p-40 re ... | 1972 | 4673488 |
| effects of actinomycin d and ultraviolet and ionizing radiation on pichinde virus. | actinomycin d (0.05 mug/ml) suppresses the synthesis of ribosomal rna of baby hamster kidney (bhk21) cells. the production of infectious pichinde virus was enhanced in the presence of actinomycin d, although the production of virus particles was not substantially different from cultures inoculated in the absence of the drug. by prelabeling bhk21 cells with (3)h-uridine and then allowing the virus to replicate in the presence of actinomycin d, it was possible to show that ribosomal rna synthesize ... | 1973 | 4199107 |
| polymerase activity of pichinde virus. | pichinde virus, a member of the arenavirus group, was examined for polymerase activity. purified virus was found to contain rna-dependent rna polymerase but not rna-dependent dna polymerase activity. since rnase but neither dnase nor actinomycin d inhibited the endogenous polymerase reaction, rna of the virus appeared to be used as the template. the divalent cations mg(2+) and mn(2+) were required for optimal reactivity. the rna product was partially resistant to rnase and the resistant portion ... | 1974 | 4132669 |
| complete sequence of the s rna of lymphocytic choriomeningitis virus (we strain) compared to that of pichinde arenavirus. | previous studies have reported that the 3' half of the small, s, rna species of the we strain of lymphocytic choriomeningitis (lcm) virus codes for the viral nucleoprotein in a subgenomic, viral-complementary, mrna species (romanowski, v. and bishop, d.h.l. (1985) virus res. 2, 35-51). the complete sequence of the lcm-we s rna has now been obtained, indicating that the 5' half of the rna codes for the viral glycoprotein precursor in a viral-sense sequence that does not overlap the n gene. it is ... | 1985 | 4060885 |
| thermal inactivation of pichinde virus. | detailed information regarding the kinetics of thermal inactivation of pichinde, an arenavirus, is presented. inactivation of virus infectivity proceeded as a first order reaction over the temperature range 22-53 degrees c. the determined inactivation rates analysed as a function of absolute temperature revealed that two different reactions were involved. below 37 degrees c, the energy of activation was determined to be compatible with rna degradation, whereas at higher temperatures a correspond ... | 1985 | 4030997 |
| conserved sequences and coding of two strains of lymphocytic choriomeningitis virus (we and arm) and pichinde arenavirus. | analyses of the 3' end sequences of the small, s, and large, l, rna species of lymphocytic choriomeningitis (lcm) virus isolates arm and we, and dna clones of lcm-we, have shown that there are extensive rna sequence homologies between the 3' ends of the two rna species of both lcm strains. limited sequence data of dna clones representing the lcm-we l rna species indicate that a gene product (presumably the minor 200 kdalton virion protein) is coded in a viral-complementary mrna species. sequence ... | 1985 | 3984491 |
| exquisite specificity of adoptive immunization in arenavirus-infected mice. | lymphocytic choriomeningitis virus (lcmv)-infected mice can be adoptively immunized with t cells from immune mice sharing mhc compatibility in h-2k or d, suggesting direct cytotoxic effects of t cells in vivo. however, t cells, upon recognition of an appropriate target, secrete lymphokines which may be capable of mediating antiviral effects nonspecifically. in this report we show that lcmv-immune cells reduced lcmv spleen titers in mice infected with lcmv alone or with lcmv and pichinde virus (p ... | 1985 | 3877492 |
| ribonucleoprotein complexes associated with virions of pichinde virus and pichinde virus-infected cells. | 1986 | 3724669 | |
| regulation of pichinde virus replication in vero and bhk-21 cells. | 1986 | 3724667 | |
| biobreeding/worcester (bb/wor) rats are deficient in the generation of functional cytotoxic t cells. | the biobreeding/worcester (bb/wor) rat provides a good model of spontaneous autoimmune diabetes. there are several sublines of the bb/wor rat. the diabetes prone (dp) sublines develop diabetes at a frequency of 50 to 80% from 60 to 120 days of age. the dp rats are lymphopenic, have a severe deficit in phenotypic ox 19+ ox 8+ cytotoxic t cells (tc), and lack rt 6.1 t cells. these rats have a relative increase in ox 19- ox 8+ natural killer (nk) cells and in nk activity as compared with the diabet ... | 1987 | 3497974 |
| studies concerning the relationship of pichinde virus-induced natural killer cells and cytotoxic t lymphocytes. | 1986 | 3487704 | |
| localization of an arenavirus protein in the nuclei of infected cells. | host cell nuclear involvement in an arenavirus infection was examined by immunofluorescence. both polyclonal antisera and monoclonal antibodies specific for the major nucleocapsid (n) polypeptide revealed virus-specific nuclear inclusions in pichinde virus-infected vero cells. immunoprecipitation of infected cell extracts with the anti-n monoclonal antibodies and subsequent analysis by sds-page, identified two n-related proteins with mol. wt. of 36,000 (p36) and 28,000 (p28) in addition to the n ... | 1987 | 3309183 |
| immune serum increases arenavirus replication in monocytes. | the u937 monocytic cell line was used to determine whether antibodies could facilitate infection and replication of the arenaviruses, pichinde virus (pv) and lassa fever virus (lfv). when high dilutions of pv-immune serum were added to cultures simultaneously with pv inoculum, virus replication was dramatically (1000-fold) increased. low dilutions of this antiserum neutralized the virus. lfv also replicated in u937 cells. the presence of lfv-specific immune serum in the growth medium increased t ... | 1988 | 3292697 |
| characterization of temperature-sensitive mutants of pichinde virus. | the synthesis of viral proteins and s rnas in cells infected with 12 temperature-sensitive (ts) mutants of pichinde virus was characterized. the mutants could be divided into five groups on the basis of the patterns of radiolabeled proteins immunoprecipitated from infected-cell lysates. markedly reduced nucleoprotein levels and undetectable amounts of glycoprotein precursor and l protein were synthesized at the nonpermissive temperature in cells infected with five of the mutants. reduced but det ... | 1988 | 3172336 |
| a newly developed immunofluorescent assay for determining the pichinde virus-inhibitory effects of selected nucleoside analogues. | an immunofluorescent assay (ifa) for pichinde virus (pcv), a member of the family arenaviridae, was developed for antiviral drug assays against the virus. the assay was performed by adding fluorescein-labeled anti-pcv monoclonal antibody to virus-infected cells at 24 h after the initial infection and counting the infected cells with an epifluorescence microscope. the average 50% effective dose (ed50) for a series of nucleoside analogues tested against pcv using this ifa was: 2-beta-d-ribofuranos ... | 1988 | 3069048 |
| [isolation and characteristics of monoclonal antibodies to the pichinde arenavirus]. | 1988 | 3051668 | |
| studies of the coagulation system in arenaviral hemorrhagic fever: experimental infection of strain 13 guinea pigs with pichinde virus. | significant coagulation abnormalities were associated with experimental infection of strain 13 guinea pigs with pichinde virus, an arenavirus related to the virulent human pathogens junin, machupo, and lassa viruses. infected animals developed decreased activity of multiple coagulation factors, decreased antithrombin iii levels, high levels of fibrin-fibrinogen degradation products, impaired platelet function, and thrombocytopenia. testing for the presence of a coagulation inhibitor revealed a p ... | 1987 | 3030150 |
| association of reduced interleukin-2 production with genetic susceptibility to pichinde virus in inbred strains of hamsters. | adult inbred mha hamsters are susceptible to lethal infections with pichinde virus while inbred lsh hamsters resist such infections. previous studies demonstrated higher levels of endogenous and induced natural killer (nk) activity in mha splenocytes than in lsh splenocytes. preferential replication of pichinde virus in cells with nk activity was suggested by showing that the greater numbers of infected spleen cells observed in mha hamsters could be accounted for by a cell population that cosedi ... | 1987 | 3028332 |
| accumulation and chemotaxis of natural killer/large granular lymphocytes at sites of virus replication. | a model for monitoring the accumulation of natural killer cell/large granular lymphocytes (nk/lgl) at a site of virus replication was studied by using mice infected i.p. with either lymphocytic choriomeningitis virus (lcmv), murine cytomegalovirus (mcmv), mouse hepatitis virus (mhv), pichinde virus, or vaccinia virus. an i.p. but not i.v. infection resulted in a localized increase in nk/lgl cell number (a fourfold to greater than 20-fold increase) and augmentation (a 10- to 20-fold increase) of ... | 1987 | 3027167 |
| evidence for the involvement of sulfidopeptide leukotrienes in the pathogenesis of pichinde virus infection in strain 13 guinea pigs. | strain 13 guinea pigs inoculated subcutaneously with pichinde virus developed fever, lost body weight, decreased water and food consumption, and died at 14 +/- 0.6 days. after fpl-55712, a leukotriene d4 antagonist, was administered beginning on pid (post-inoculation day) 3 for 18 days, the magnitude of body weight loss decreased and food intake increased, despite a persistent fever. the treated guinea pigs also survived significantly longer than infected animals receiving placebo injection (21 ... | 1986 | 3025893 |
| [production of infectious virus and the accumulation in vero cells of pichinde virus antigens detectable by an indirect fluorescent antibody method]. | the dynamics of accumulation of infectious pichinde virus in the culture medium and virus-specific antigens in cells was studied in relation to multiplicity of infection in a multicycle experiment. differences in the fluorescence pattern of pichinde virus antigens in ifat were found to depend on the use of acetone or formaldehyde for fixation of the infected cells. | 2010 | 3020808 |
| antibody to mouse alpha/beta interferon abrogates pichinde virus-induced liver lesions in suckling mice. | infection of newborn c3heb/fej mice with the arenavirus pichinde resulted in stunted growth, severe liver cell degeneration, and death. administration of sheep anti-mouse alpha/beta interferon globulin completely abrogated liver lesions in virus-infected mice, although it did not decrease the incidence of mortality. these results indicate that endogenous interferon may be responsible for some manifestations of viral disease. | 1986 | 3016334 |
| intraepithelial leukocytes contain a unique subpopulation of nk-like cytotoxic cells active in the defense of gut epithelium to enteric murine coronavirus. | initially the intraepithelial leukocytes (iel) of specific pathogen free (spf) mice were compared with those of mice held without isolation and were found to differ markedly in total number and distribution of cell surface antigens. the iel from spf mice expressed significantly less thy-1, lyt-1, and lyt-2 antigens than their conventional counterparts. the local cell-mediated immune response of mucosal lymphocytes to an enteric murine coronavirus (mhv-y) was studied in inbred strains of naive sp ... | 1986 | 3005395 |
| abrogation of anti-pichinde virus cytotoxic t cell memory by cyclophosphamide and restoration by coinfection or interleukin 2. | previously, we demonstrated that memory cell-mediated immune responses can be generated in pichinde virus (pv)-primed mice after secondary challenge in vivo with homologous virus. further, treatment of mice with cyclophosphamide (cy) before primary infection with pv abrogated the generation of h-2-restricted, virus-specific cytotoxic t lymphocytes (ctl), and rechallenge of these mice was followed by neither a primary nor a secondary ctl response. here, we demonstrate that this cy-induced block i ... | 1985 | 2989365 |
| changes in body weight and body surface area in strain 13 guinea pigs infected with pichinde virus. | in studying pathogenetic mechanisms of pichinde virus-induced disease in strain 13 guinea pigs, a large decrease of body weight (approximately 28%) observed within 14 days postinoculation raises a question concerning the validity of standardizing body or organ functions in terms of body weight. this study was to examine changes in body weight and body surface area of pichinde virus-infected strain 13 guinea pigs after various days postinoculation. control guinea pigs were also subjected to the s ... | 1989 | 2915597 |
| neurochemical changes in brains of mice infected with pichinde virus. | 1986 | 2873503 | |
| observation of the in situ contracting heart of guinea pigs infected with pichinde virus. | the in situ beating hearts from anesthetized control and pichinde virus-infected strain 13 guinea pigs, between days 7 and 19 postinoculation, were directly observed and video recorded. although some hearts from pichinde virus-infected animals were visually depressed and had altered contraction patterns, such a pronounced cardiac dysfunction was not associated with any marked histopathological changes in the cardiac tissue. the manifestations of cardiac dysfunction were limited mainly to the rig ... | 1987 | 2824949 |
| pathogenesis of viral hemorrhagic fevers: rift valley fever and lassa fever contrasted. | although many viral infections have on occasion been associated with hemorrhagic complications, infection with any of several rna viruses regularly results in vascular involvement and the syndrome called viral hemorrhagic fever (vhf). in spite of clinically useful similarities among various vhfs, there are significant differences in their pathogenesis and clinical evolution; these are often related to characteristics of their viral taxon. infection with rift valley fever (rvf) virus, a phlebovir ... | 1989 | 2665011 |
| replication of hemorrhagic fever viruses in monocytic cells. | monocytes play a central role in protection against many viruses. in some infections they are target cells for viral replication. there is increasing evidence that these cells may also be important in regulation of hemostasis. the part played by monocytic cells in the pathogenesis of hemorrhage in the viral hemorrhagic fevers is presently uncertain. monocytes and monocytic cell lines have been used to investigate the ability of viruses to infect these cells in vitro. several factors may affect t ... | 1989 | 2665010 |
| arenavirus infection in the guinea pig model: antiviral therapy with recombinant interferon-alpha, the immunomodulator cl246,738 and ribavirin. | human arenaviral infections have a high mortality, and are dangerous to work with in the laboratory. there is a need for good antiviral agents to treat these infections. pichinde virus infection of the inbred strain 13 guinea pig is a relatively safe, good animal model for human arenavirus infections. mortality is consistently 100% between days 12 and 25 (mean 14.8) days after infection. when infected animals were treated with recombinant human interferon alpha a, or with cl246,783, an immunomod ... | 1989 | 2561334 |
| virus-induced polyclonal cytotoxic t lymphocyte stimulation. | infections with a variety of viruses (lymphocytic choriomeningitis (lcmv), murine cytomegalovirus, pichinde virus, vaccinia virus) stimulated c57bl/6 mice to generate allospecific ctl coincidental with the generation of virus-specific ctl. in c57bl/6 (h-2b) mice, lcmv-induced ctl with reactivity against cells from mice bearing gene products of the d, f, k, p, q, and s but not the b mhc loci. studies with congenic mouse strains indicated that the mhc loci coded for the target of the allospecific ... | 1989 | 2537363 |
| properties and characterization of monoclonal antibodies to tacaribe virus. | monoclonal antibodies prepared against tacaribe and junin viruses have been used to define further the serological relationships between arenaviruses of the tacaribe complex. a close relationship was found between these two viruses and the heterologous amapari and machupo viruses, with pichinde virus and parana virus being more distantly related. among the antibodies specific for tacaribe virus, five were found to react with viral antigens at the surface of infected cells and to neutralize virus ... | 1985 | 2410550 |
| inhibition of diabetes in bb rats by virus infection. ii. effect of virus infection on the immune response to non-viral and viral antigens. | lymphocytic choriomeningitis virus (lcmv) infection prevents the usual insulin-dependent diabetes mellitus of aged bb rats (dyrberg, schwimmbeck & oldstone, 1988; schwimmbeck, dyrberg & oldstone, 1988). in this study earlier observations are extended by noting that lcmv infection substantially alters the immune responsesof bb diabetic-prone (dp) rats. the control, uninfected rats make vigorous primary and secondary antibody responses when challenged with keyhole limpet haemocyanin (klh), human i ... | 1990 | 2335372 |
| cytotoxic t lymphocytes do not control lymphocytic choriomeningitis virus infection of bb diabetes-prone rats. | biobreeding worcester diabetes-prone (bbdp) rats develop insulin-dependent autoimmune-driven diabetes mellitus spontaneously and intravenous administration of 1 x 10(7) p.f.u. of lymphocytic choriomeningitis virus (lcmv) to young adult mice prevents disease. the virus is lymphotropic, binding to and replicating in such cells. bbdp rats fail to generate virus-specific major histocompatibility complex-restricted cytotoxic t lymphocyte (ctl) responses when challenged with this dose or other doses o ... | 1990 | 2324708 |
| pichinde virus infection in strain 13 guniea pigs reduces intestinal protein reflection coefficient with compensation. | pichinde virus inoculation into strain 13 guinea pigs is a model with features reputed to be similar to hemorrhagic fever in humans. although the infection is lethal by day 13-19, guinea pigs of approximately 600 g do not show edema or effusions. this raises the questions of whether capillary damage is present in such infected animals and, if it is, why edema is absent. the effects of pichinide virus on protein transport across jejunal capillaries were examined in 38 normal and 7 infected strain ... | 1990 | 2230259 |
| characterization of pichinde virus infection of cells of the monocytic lineage. | to establish a model of viral infection of monocytes, we examined infection of human cells and cell lines of the monocytic series with the arenavirus pichinde virus. we demonstrate for the first time that human peripheral blood monocytes are susceptible to pichinde virus infection, as shown by immunoprecipatation of virus-specific polypeptides from infected cells, immunofluorescence analyses, and quantitation of virus production from infected cells. the human promyelocytic leukemia cell line hl6 ... | 1991 | 2041083 |
| the effect of an arenavirus infection on liver morphology and function. | patients with severe lassa fever have high serum levels of liver enzymes. studies of the histology of the liver have shown only minor alterations, seemingly insufficient to account for death. pichinde virus is an arenavirus which causes severe illness similar to lassa fever in strain 13 guinea pigs, but does not cause severe illness in man. this can serve as a relatively safe model for studying the pathology and pathophysiology of fatal arenaviral infection. we used this infection to evaluate th ... | 1990 | 1974392 |
| influence of volume expansion on capillary transport in the gut of pichindé virus infected strain 13 guinea pigs. | hydropenic strain 13 guinea pigs (gp13) injected with pichindé virus show marked jejunal capillary disruption determined by a reduction in protein reflection coefficient (sigma) [katz and starr, 1990]. these studies examined whether this is reversed by a 2% ringer's expansion, and whether anorexia may contribute to reduced sigma. gp13 were either infected or given a 60% expected ad lib diet, and were studied while under a 2% ringer's expansion. the results showed 1) infected gp13 separated into ... | 1991 | 1940885 |
| natural killer (nk) cell response to virus infections in mice with severe combined immunodeficiency. the stimulation of nk cells and the nk cell-dependent control of virus infections occur independently of t and b cell function. | the activation, proliferation, and antiviral properties of natural killer (nk) cells were examined in severe combined immunodeficiency (scid) mice to determine the influence of mature t or b cells on virus-induced nk cell functions and to more conclusively determine the antiviral properties of prototypical cd3- nk cells. nk cells were activated to high levels of cytotoxicity 3 d after infection of mice with lymphocytic choriomeningitis virus (lcmv) or murine cytomegalovirus (mcmv). analyses of s ... | 1991 | 1850779 |
| assessment of the specificity of cytotoxic t lymphocytes for the nucleoprotein of pichinde virus using recombinant vaccinia viruses. | pichinde virus (pv) infection of mice results in induction of a strong h-2 restricted, virus-specific cytotoxic t lymphocyte (ctl) response and rapid clearance of the virus. to define the specificities of ctl induced by pv infection, we constructed vaccinia virus recombinants containing cloned cdnas corresponding to full-length (vvnp) and a truncated form (vvnp 51-561) of the nucleoprotein (np) gene of pv. radioimmunoprecipitation analysis of infected cell lysates indicated that vvnp expressed a ... | 1990 | 1701987 |
| pulmonary responses of conscious strain 13 guinea pigs to pichinde viral infection. | a laboratory animal model for studying pulmonary responses to arenaviral infection was established with advanced technologies. tidal volume (tv), respiratory rate (rr), minute volume (mv), expiratory time (te), inspiratory time (ti), peak expiratory flow (pef), and specific pulmonary airway resistance (res) were measured with a double plethysmograph and a computer data-acquisition system in six conscious, strain 13 guinea pigs. using the same animal, experiments were conducted before and after s ... | 1991 | 1667202 |
| antiviral immunotoxins: antibody-mediated delivery of gelonin inhibits pichinde virus replication in vitro. | immunotoxins were produced and evaluated for antiviral activity against pichinde virus, a member of the family arenaviridae. immunoglobulins were conjugated to the ribosome-inactivating protein, gelonin, through a disulfide linkage to form the immunotoxins. immunotoxins were produced utilizing monoclonal antibodies, immunoglobulin-binding proteins and hyperimmune sera. an immunotoxin consisting of hyperimmune rabbit sera conjugated with gelonin displayed strong antiviral activity against pichind ... | 1991 | 1650165 |
| metabolism of platelet-activating factor in neutrophils isolated from pichinde virus-infected guinea pigs. | metabolism of platelet-activating factor (paf) was studied in cultured polymorphonuclear neutrophils (pmns) obtained from pichinde virus-infected strain 13 guinea pigs. neutrophils obtained from control and infected guinea pigs on postinoculation days 10 and 14 were incubated with [3h]lyso-paf, [3h]paf, or [3h]acetate. after incubation for 1 h at 37 degrees c, formation of [3h]acyl-paf from either [3h]lyso-paf or [3h]paf increased significantly in pmns from infected guinea pigs compared to contr ... | 1992 | 1541904 |
| generation of "natural killer cell-escape" variants of pichinde virus during acute and persistent infections. | pichinde virus (pv) strain an 3739 was determined to be sensitive to natural killer (nk) cells in vivo by enhanced replication in nk-cell-depleted mice. an nk-sensitive subclone (pv-nks1) was serially passed in mice whose nk cells had previously been activated by an interferon inducer, and two plaque isolates were shown to be resistant to nk cells but not to interferon. inoculation of severe-combined-immunodeficient mice with pv-nks1 led to a persistent infection resulting in an nk-resistant vir ... | 1992 | 1372371 |
| increased platelet-activating factor (paf) concentrations in hearts and lungs of pichinde virus-infected guinea pigs. | platelet-activating factor (paf) has been implicated as a cause of cardiopulmonary disturbances in certain diseases. in the present study, concentrations of paf in hearts, lungs, whole blood, and other organs of control and pichinde virus-infected guinea pigs on post-inoculation days (pid) 10 and 14 were measured by radioimmunoassay. results were further confirmed by bioassay after separation and purification with thin-layer chromatography. paf concentration in the hearts and lungs of virus-infe ... | 1992 | 1334721 |
| possible involvement of endogenous beta-endorphin in the pathophysiological mechanisms of pichinde virus-infected guinea pigs. | previously, we demonstrated that naloxone, an opiate antagonist, prolonged survival of strain 13 guinea pigs infected with pichinde virus. thus, endogenous opiates may be involved in the pathogenesis of this viral disease. to determine whether endogenous opiate levels were affected by pichinde viral infection, beta-endorphin concentrations in plasma and cerebrospinal fluid (csf) of normal and infected strain 13 guinea pigs were measured by radioimmunoassay. cerebrospinal fluid beta-endorphin con ... | 1992 | 1319583 |
| requirement of cell nucleus for the replication of an arenavirus. | baby hamster kidney (bhk21) cells enucleated with cytochalasin b were infected with pichinde virus or sindbis virus. viral replication was measured by plaque assay, and the synthesis of viral antigens was determined by immunofluorescence. pichinde virus replication was completely inhibited in cells enucleated prior to infection as measured by both techniques while the replication of sindbis virus was unaffected. enucleation of cells at different times after infection with pichinde virus indicate ... | 1975 | 1235853 |
| isolation of ribosome-like sturctures from pichinde virus. | three classes of mamalian ribosome-like structures were found to be associated with purified pichinde virus preparations. these structures, possessing sedimentation coefficients of 80s, 60s and 40s, were sensitive to edta dissociation and possessed a buoyant density in caesium chloride of 1-61 g/ml, a value analogous to that displayed by bhk21 cell ribosomes. analyses of rna components associated with ribosomal particles of pichinde virus established that 28s and 18s rnas could be extracted from ... | 1975 | 1168240 |
| arenaviruses: purification and physicochemical nature. | the arenaviruses are a group of enveloped viruses having as a unique morphological finding the presence in the virion of granules instead of a defined core. the viruses contain a single-stranded rna genome, but appreciable amounts of ribosomal-like rna and 4-6s rna of host cell origin have been detected. little information is available on the mode of replication of the viral nucleic acids. a virion-associated rna-dependent rna polymerase has been described and there is indirect evidence to sugge ... | 1975 | 1085204 |
| inhibition of pichinde virus replication by actinomycin d. | the yields of pichinde virus, a member of the arenavirus group, were markedly inhibited when infected bhk 21 cells were incubated in the presence of 0.4 to 4 mug/ml of actinomycin d. maximal inhibition was observed when actinomycin d was added after the adsorption of virus to cultures; however, addition of drug as late as 12 h after infection reduced the 24 h yield by 50%. virus antigen synthesis, as measured by complement fixation and immunodiffusion, was not dramatically reduced by actinomycin ... | 1976 | 1003168 |
| arenavirus inactivation on contact with n-substituted isatin beta-thiosemicarbazones and certain cations. | n-methyl and n-ethyl isatin beta-thiosemicarbazones inactivate cell-free parana and pichinde viruses as well as three strains of lymphocytic choriomeningitis virus. this antiviral activity is abolished in the presence of the chelating agent edta. the rate of virus inactivation by n-methyl isatin beta-thiosemicarbazone is greatly enhanced and controlled by the addition of cupric sulphate. divalent cations of other first transition series metals are less effective. a difference exists in the coppe ... | 1975 | 809544 |
| arenavirus defective interfering particles mask the cell-killing potential of standard virus. | lymphocytic choriomeningitis virus (lcm) and pichinde virus grew readily and produced cytopathology in mdck and pk-15 cells. it is known that in these cell lines, the synthesis or function of defective interfering (di) virus particles is restricted. survival curves of single mdck cells infected with low multiplicities of lcm showed one-particle-to-kill kinetics. at high multiplicities of infection, there was a maximum degree of cell-killing, or even a reduction in the amount of cell-killing, dep ... | 1978 | 627871 |
| differences between syrian hamster strains in natural killer cell activity induced by infection with pichinde virus. | 1979 | 501084 | |
| the reticuloendothelium as the target in a virus infection. pichinde virus pathogenesis in two strains of hamsters. | the course of pichinde virus infection in two strains of hamsters, lvg and mha, was studied by sequential frozen-section immunofluorescence and light and electron microscopy. the major destructive effects of the infection were in the spleen and liver. in the spleen, primary target cells were macrophages in the marginal zone of the white pulp with subsequent spread into elements of the red pulp. in the liver, there was kupffer cell and hepatocellular infection. the extent of involvement correlate ... | 1977 | 335164 |
| cytotoxic cells induced during lymphocytic choriomeningitis virus infection of mice. i. characterization of natural killer cell induction. | lymphocytic choriomeningitis virus (lcmv) infection of c3h/st, nude (balb/c background), and other mice induced high levels of natural killer (nk) cell activity in the spleen and peritoneum. l-929 cells were used as targetsand were not lysed by spleen or peritoneal cells from uninfected mice. the cytotoxic cells were characterized as nk cells because they were nonadherent, nonphagocytic lymphocytes lacking theta and immunoglobulin antigens on their plasma membranes. their activity was sensitive ... | 1978 | 307587 |
| distinctive rna transcriptase, polyadenylic acid polymerase, and polyuridylic acid polymerase activities associated with pichinde virus. | three rna polymerase activities were found and associated with purified pichinde virus, a member of the arenaviridae. a heat-labile polymerase activity which required all four ribonucleoside triphosphates for optimal activity co-sedimented on sucrose gradient centrifugation with the viral ribonucleoprotein complex from detergent-disrupted virus preparations. this enzyme synthesized heteropolymers which represented about 23% of the genome rna as determined by nucleic acid hybridization. two relat ... | 1979 | 225533 |
| pseudotypes of vesicular stomatitis virus and pichinde virus. | super-infection of pichinde virus-infected cells with vesicular stomatitis virus (vsv) resulted in the production of pseudotype virus which was not neutralized by antiserum to vsv but which was neutralized by antiserum to pichinde virus. analysis of pseudotype virus production in relation to the kinetics of replication of pichinde virus demonstrated that pseudotype virus production occurred when super-infection with vsv was initiated 8 h or more after infecting the cells with pichinde virus. the ... | 1979 | 215705 |
| structural components of the arenavirus pichinde. | purified pichinde virions grown in monolayers of bhk-21 cells were found to contain three major species of virion proteins as described previously (ramos et al., j. virol. 10:661-667, 1972). two of the proteins were glycosylated (g1, molecular weight = 64,000; g2, molecular weight = 38,000) and were present in similar proportions on the outer surface of the virions. a third protein (n, molecular weight = 66,000) was not glycosylated and, in association with the viral rna species, was the major p ... | 1977 | 197271 |
| virion-associated ribosomes are not required for the replication of pichinde virus. | 1977 | 196399 | |
| variation between strains of hamsters in the lethality of pichinde virus infections. | infection by pichinde virus, a member of the arenavirus group, was studied in golden syrian hamsters (mesocricetus auratus) with regard to possible mechanisms of resistance to virus infection in adult hamsters. two hamster strains were found to differ in their susceptibility to lethal pichinde virus infection. lvg/lak randomly bred hamsters were found to be 100% susceptible to low doses of pichinde virus during the first 6 days of life, but after 8 days of life, mortality was uncommon. peak viru ... | 1977 | 193786 |
| strandedness of pichinde virus rna. | the pichinde virus rna did not possess the following characteristics of eucaryotic mrna: polyadenylic acid sequence, capped methylated structure, and ability to direct protein synthesis in vitro. polysomal rna extracted from cells infected with pichinde virus reannealed with 32p-labeled virus rna, protecting about 60% of the latter against rnase degestion. the polyadenylic acid-containing polysomal rna also reannealed to the 32p-labeled virus rna to approximately the same extent. these indicate ... | 1977 | 192915 |
| antigens of pichinde virus i. relationship of soluble antigens derived from infected bhk-21 cells to the structural components of the virion. | antigens detected by the complement-fixation (cf) test were prepared from bhk-21 cells infected with pichinde virus. the preparations contained two antigens demonstrable by immunodiffusion. the antigen present in abundance was heat stable, pronase resistant, and had a molecular weight of 20,000 to 30,000 as estimated by gel filtration. polyacrylamide gel electrophoresis of purified antigen demonstrated two low-molecular-weight polypeptides. an identical antigenic determinant was found by disrupt ... | 1977 | 67220 |