Publications

TitleAbstractYear
Filter
PMID
Filter
immune response to vaccination with a live influenza virus (h3n2) vaccine ("ann" strain).a live attenuated influenza virus ("ann" strain) derived from a/england/878/69 was given intranasally to a group of volunteers, most of whom had already circulating antibodies against h(3)n(2) viruses at the time of inoculation. there was a fourfold or higher increase of circulating hemagglutination-inhibiting antibodies in those volunteers who had relatively low initial titers. the response was lower in those with initially higher serum titers. the pattern of the serum neutralizing antibody res ...19734729931
temperature-sensitive mutants of influenza virus. 3. further characterization of the ts-1(e) influenza a recombinant (h3n2) virus in man. 19734743544
in vitro effect of virazole against influenza viruses.the minimal inhibitory concentrations of virazole against 32 mean tissue culture infective doses of three type a influenza strains including type a/england/42/72 (h3n2) and a type b strain in tissue culture were 0.1 and 0.05 mug/ml, respectively. the growth inhibition pattern by various virazole concentrations of type a virus was similar to that of the type b virus. virazole appears to be slightly more potent against the a/england/42/72 strain than are other antiinfluenzal agents.19734793883
immunity to influenza in ferrets. x. intranasal immunization of ferrets with inactivated influenza a virus vaccines.the response of ferrets after intranasal inoculation of inactivated a/hong kong/68 (h3n2) influenza virus vaccines is reported. normal ferrets given either saline vaccine in drops or freeze-dried vaccine in an aerosol intranasally did not produce detectable serum or nasal hemagglutination inhibiting antibody and were found to be completely susceptible to challenge infection with a/hong kong/68 virus. intranasal saline vaccine did not produce an additive effect on the response of ferrets simultan ...19744830530
[heterogeneity of monospecific antibodies to the hemagglutinin of influenza virus h3n2 studied by radioimmunological analysis].heterogeneity of antibodies against influenza virus hemagglutinin has been confirmed. various subpopulations of antibodies to the a/khabarovsk/15/76 hemagglutinin were demonstrated some of which showed greater affinity to mrc-11 hemagglutinin than to the ha of the strain inducing this antibody synthesis. apparently subpopulations of antibodies with low affinity to their "own" epitopes in the hemagglutinin-immunogen may develop which, however, may show a sufficiently high affinity to these epitop ...19846084896
prevalence of antibodies against respiratory viruses in children of koulikoro (mali).the prevalence of antibodies to viruses associated with respiratory illnesses (influenza, corona, r.s., adeno, parainfluenza mycoplasma pneumoniae) has been investigated in 119 children under 3 years of age (koulikoro region mali) and 50 persons 15-19 years of age (bamako/mali). in the surveillance period (march 1982-september 1982) an outbreak of respiratory disease in association with rs virus took place. a rise of cf titer has been found in 90.8% of the children; 59.1% of them presented a fou ...19846087520
cytotoxic t cell recognition of the influenza nucleoprotein and hemagglutinin expressed in transfected mouse l cells.l cells expressing either the a/nt/60/68 nucleoprotein or the a/pr/8/34 (h1) hemagglutinin by dna mediated gene transfer were used to investigate recognition by influenza a specific cytotoxic t lymphocytes (ctl). a subpopulation of ctl that recognized the h1 hemagglutinin was detected in mice primed with either a/pr/8/34 (h1n1) or a/jap/305/57 (h2n2) influenza viruses. however, neither ctl from mice primed with a/nt/60/68 (h3n2) nor the recombinant virus x31 (h3n2) showed any activity on l cells ...19846091906
the effects of shifts and drifts on the epidemiology of influenza in man.accurate information on the epidemiology of influenza over the world is difficult to obtain as it is dependent on both national statistics of morbidity and mortality and on adequate virological confirmation of suspected cases. only a few countries have the facilities for these and in much of the world it is difficult to establish exactly the impact of influenza. for this reason, our knowledge on the natural history of the disease and the virus causing it is restricted to what happens in a few ar ...19806103560
influenza vaccines.inactivated influenza vaccines can now be made from purified haemagglutinin and neuraminidase. although they have not been fully tested in the field they probably produce as good an immunity as whole virus vaccines and fewer reactions. they could be used against a new serotype in the face of a pandemic. revaccination with killed vaccine may be effective, but one careful study in a school during the drifting of the h3n2 showed that it was not effective there overall. live influenza vaccines have ...19806103563
peculiarities of obtaining attenuated thermosensitive recombinants of influenza a virus at the end of the h3n2 epidemic cycle.the conditions of obtaining thermosensitive recombinants of the virulent a/leningrad/82/76 (h3n2) virus with two donors of attenuation, a/leningrad/134/17/57 (h2n2) and a/leningrad/9/37/46 (h0n1), were evaluated. the recombinants were obtained by various methodical approaches (hybridization of native viruses, cross-reaction and selection of recombinants at temperatures of 25, 32 and 40 degrees c) to study their effects on the degree of attenuation and the regularity of transmission of the ts mar ...19806106378
protease susceptibility of human a influenza virus polypeptides.the proteolytic susceptibility of polypeptides of four antigenically distinct subtypes of influenza a virus strains of human origin was studied. the extent of degradation of polypeptide molecules of strains a/pr/8/34 (h0n1) (pr), a/fm/1/47 (h1n1), a/singapore/1/57 (h2n2) and a/hong kong/8/68 (h3n2), assessed by densitometry of gels after sodium dodecylsulfate polyacrylamide gel electrophoresis was variable by treatment with trypsin. also, sequential treatment of pr strain initially with phosphol ...19816115561
serological evidence of natural recombinant influenza virus (hsw1n2) infection among pigs in japan.a new recombinant influenza a virus (hsw1n2) infection among hogs in miyagi prefecture, japan, was confirmed by serological examinations. nineteen out of twenty sera collected in one farm in january 1979 showed high haemagglutination inhibition antibody titres to hsw1 antigen (a/new jersey/8/76) and also significant neuraminidase inhibition antibody titres to n2 antigen of the hong kong 1973 variant (a/port chalmers/1/73) but not to n1 antigen. the results indicate the occurrence of genetic reas ...19816116417
ribavirin small-particle aerosol treatment of influenza.in an outbreak of influenza virus a/england/333/80(h1n1) infections in college students, 14 randomly selected patients were treated by inhalation of ribavirin small-particle aerosol through a face mask. they retained an average estimated 1.15 g of drug in 23 h of treatment given over 3 days. 17 patients served as controls. ribavirin aerosol treatment had a therapeutic effect judged by the highly significant reduction in height and duration of fever, reduction in systemic illness, and disappearan ...19816117726
comparative study on the inhibitory effect of rimantadine on the reproduction of epidemic strains of influenza a virus h3n2 and h1n1.the sensitivity to rimantadine of the reproduction of influenza virus a/texas/1/77 (h3n2) and a (h1n1) isolates nos 897, 778 and 782, isolated from patients during an epidemic influenza outbreak in moscow in the winter of 1977/1978 was compared. a (h3n2) virus proved to be more sensitive than the a (h1n1) viruses tested, as manifested by decreases of the infectious titre in ovo and of the haemagglutinin titre in mdck cells.19816118052
ultrastructural localization by immunoperoxidase techniques of influenza virus antigens in abortive infection of l cells.an abortive infection was induced in l cells by influenza virus a/hong kong/68 (h3n2). with the use of antibody and peroxidase-labelled protein a, the localization of virus protein synthesis but not the maturation of virus particles was demonstrated at the ultrastructural level. five days after inoculation (p.i.), the synthesis of viral haemagglutinin was localized in the region of the rough endoplasmic reticulum; at late intervals p.i., haemagglutinin accumulated in the plasma membranes, where ...19816120640
role of the heterogeneity of a/hong kong/1/68 (h3n2) influenza virus populations in establishment of persistent infection of l cells.three subpopulations of a/hong kong/1/68 (h3n2) influenza virus differing from one another in biological properties obtained by elution from deae-sephadex with phosphate buffer containing increasing concentrations (0.1, 0.5 and 1 mol/l) of nacl, were used to induce persistent infection of l929 mouse fibroblast cells. in the course of 25 passages, cell destruction occurred only at low passage levels, especially in the la-68/0.5 and la-68/all. sublines. the proliferating activities of la-68/0.1 an ...19826127011
effects of streptovirudin on influenza viruses type a and b: inhibition of the lipid-linked oligosaccharide synthesis of fowl plague virus.antibiotics of the streptovirudin complex (sv) inhibited the growth of influenza a and b viruses such as influenza a/fowl plague virus (fpv), strain weybridge (hav1 neq1), influenza a/england 42/72 (h3n2), influenza a/port chalmers 1/73 (h3n2), influenza b/leningrad 235/74, influenza b/tokyo 7/66, and influenza b/jamagata in chick embryo cell (cec) cultures, in permanent canine kidney cells (mdck), and in suspended fragments of chick embryo chorioallantoic membranes (cam). as revealed by spectro ...19826132539
e-rosette forming cells and humoral antibody titres in humans after vaccination with three different inactivated influenza virus vaccines a/ussr/92/77 (h1n1).the number of e-rosette forming cells and the serum haemagglutination inhibition (hi) antibody titres were examined in 37 volunteers immediately before and 14, 28, 35 and 63 days after immunization with three inactivated influenza virus vaccines a/ussr/92/77 (h1n1)--nib 6 and in 11 non-vaccinated controls. from the former, 10 volunteers were immunized with 1000 haemagglutinin (ha) iu per dose, 11 volunteers with the nib 6 adsorbate vaccine (340 ha iu/dose) and 16 volunteers with a bivalent vacci ...19826132540
genetic recombination between temperature-sensitive and wild-type influenza a virus strains.genetic cross was performed between a temperature-sensitive (ts) mutant of influenza virus a/wsn (h0n1) which carries a ts lesion in m gene, and a wild type a/aichi/2/68 (h3n2). twelve clones were isolated randomly from the mixed yield in the absence of any selective procedure and they were individually examined for their ts character. in addition, structural and non-structural polypeptides of an individual clone were analyzed by sds-polyacrylamide gel electrophoresis (page) to identify from whi ...19836133427
differentiation of influenza a virus nucleoproteins in enzyme-linked immunosorbent assay.the serum antibody titre to the nucleoprotein (np) of the influenza virus recombinant mrc-11 was determined in virus strains a/ussa/5/80 (h3n2), a/hong kong/8/64 (h3n2), a/duck/ukraine/63 (hav7neq2) and in a recombinant strain between a/tern/frunse/334/78(hav4nav1) and a/pr/8/34(h0n1) using the enzyme-linked immunosorbent assay (elisa). significant differences between the np of these strains were found proving the usefulness for elisa for such investigations.19836133433
the influence of ph and ionic strength on the single radial immunodiffusion test in qualitative assay of influenza virus haemagglutinin.a significant dependence between different ionic strength and ph value of virus suspension on one hand and the haemagglutinin (ha) content as determined by single-radial-immunodiffusion (srd) test on the other hand was observed after cleavage of influenza virus recombinant nib-6 (h1n1) with sodium lauroyl sarcosinate (sls). in contrast, no such relationship was found when the ha of nib-4 (h3n2) recombinant strain was determined.19836139944
high reproduction capacity of recombinants between h3n2 human influenza and fowl plague viruses is due to the gene coding for m proteins.recombinants between h3n2 human influenza viruses (a/victoria/3/75 and a/bangkok/1/79, low-yielding parents in chick embryos) and fowl plague virus (fpv, a high-yielding parent in chick embryos) have been obtained. the high reproductive capacity of recombinants in chick embryos has been shown to be due to the gene coding for m proteins.19836139948
role of genes 4 and 6 for the expression of some biological properties of influenza virus a/pr/8/34.genetic composition and biological properties of influenza virus recombinants a/pr/8/34 (h1n1) and a/greifswald/6/74 (h3n2) were analysed. the haemagglutinin (ha) gene of the strain a/pr/8/34 was shown an important part of the gene complex determining the virulence for mice, the yield of ha and the plaque forming capacity. the exchange of the ha gene with that of an another strain led to a drastic reduction of these properties. on the other hand, the introduction of the ha gene of a/pr/8/34 stra ...19836140830
k2-tartarate gradient centrifugation in the isolation of purified influenza virus haemagglutinin after bromelain cleavage.a method of haemagglutinin (ha) purification by means of k2-tartarate gradient centrifugation is described. different influenza virus strains possessing the antigenic formulas h1n1, h2n2 and h3n2 yielded pure and immunologically active ha samples.19836140831
blastogenic lymphocyte response as indicator of cell-mediated immunity in humans vaccinated with live and inactivated influenza vaccines.the level and dynamics of lymphocyte blastogenesis in response to phytohaemagglutinin (pha) and to specific influenza virus antigen were studied in 3 groups of humans, vaccinated with live or inactivated whole virion influenza vaccines (h3n2 type) and placebo (control group). both live and inactivated influenza vaccines did not change significantly the functional activity of t lymphocytes as determined by the mean values of stimulation index (si). the analysis of individual values of pha-depende ...19836140837
advantage of live attenuated cold-adapted influenza a virus over inactivated vaccine for a/washington/80 (h3n2) wild-type virus infection.the efficacy of live attenuated cold-adapted (ca) reassortant influenza virus vaccine against experimental challenge with homologous wild-type virus 5 to 8 weeks after vaccination was compared with that of licensed inactivated vaccine in 81 seronegative (haemagglutination-inhibition antibody titre less than or equal to 1:8) college students. at a dose of 10(7.5) 50% tissue culture infectious dose (tcid50) (70 hid50, human 50% infectious doses) the live virus vaccine, given intranasally, complete ...19846143042
antiviral activity of aryl-furfurane derivatives.of 27 aryl-furfurane derivatives (afd) studied, 13 compounds were found to have antiviral activity against echo 6, herpes simplex, vaccinia, and influenza a/hong kong/1/68 (h3n2) viruses, the highest inhibition being observed with echo 6 virus. the maximum tolerated concentrations (matc) of afd inhibited the macromolecular syntheses in echo 6 virus-infected cell cultures.19846143495
location of ts defects in the genome of cold-adapted recombinant influenza a virus vaccine strains.the ts phenotype and location of ts mutations were studied in the genome of parent viruses and those obtained by recombination of cold-adapted strains a/leningrad/134/17/57 or a/leningrad/134/47/57 with epidemic h1n1 and h3n2 influenza a virus strains. the epidemic h1n1 and h3n2 strains under study possessed a ts phenotype and contained ts mutations in one or two genes. the ts phenotype was lost following three clonings at 40 degrees c, suggesting that influenza virus strains isolated from human ...19846147996
the intestine of ferret--a possible site of influenza virus replication.anal virus shedding and stimulation of the immune response were observed in ferrets after oral and rectal administration of influenza a/hongkong/1/68 (h3n2) virus. despite of the low ph in the stomach, the virus had reached the intestines after oral administration and was found in high concentration in faeces and in mucosal cells lining the colon. using immunofluorescent staining, the virus antigen was detected in cytoplasm of columnar epithelial cells. virus replication also occurred in the res ...19846148853
genome analysis of epidemic influenza virus strains isolated in 1979-1983.comparative studies on the electrophoretic mobility of double-stranded rna segments constructed of the genome of isolates under study and of reference influenza virus strains of respective serotypes are suggestive for the evolution of majority of the genes of both a and b influenza viruses, including their genes coding for non-glycosylated proteins. among influenza a and b virus strains which were circulating during the same epidemic, there were variants differing from each other in a number of ...19846152126
amino acid sequence changes in the haemagglutinin of a/hong kong (h3n2) influenza virus during the period 1968--77.haemagglutinin molecules from nine strains of a/hong kong/68 (h3n2) influenza virus, isolated between 1968 and 1977, were examined for changes in amino acid sequences. at least 18 changes, 9 of which were located precisely, occurred in the soluble tryptic peptides of the large haemagglutinin polypeptide (ha1) during this period. these peptides contained 262 residues (82% of ha1). in ha2, only two changes in 129 residues (58% of ha2) were detected. sequential changes at a particular locus were no ...19806153236
mitogen responses and interferon production after exposure of human macrophages to infectious and inactivated influenza viruses.human macrophages were exposed to two influenza a viruses representing different subtypes. the donors were likely to have been exposed to one subtype (h3n2) but not to the other (h0n 1). similar effects upon the macrophages were observed for both subtypes: macrophage enhancement of mitogen-stimulated lymphocyte transformation responses was depressed, and the macrophages produced interferon. in contrast, macrophages exposed to inactivated virus exhibited normal enhancement of lymphocyte transform ...19806155437
radioimmunoassay of influenza a virus haemagglutinin. ii. antigenic cross-reactions of influenza a (h3 subtype) viruses as determined by radioimmunoassay and haemagglutination inhibition tests.individual rabbits differed greatly in their antibody response to the "strain-specific" and "cross-reactive" antigenic determinants on the haemagglutinin (ha) subunit of influenza virus recombinant mrc11 (h3n2) and influenza virus dunedin (h3n2), after immunization with whole virus or bromelain-released haemagglutinin (b-ha). consequently, diverse cross-reactions between htese viruses and a/hong kong/68 virus were found in the haemagglutination inhibition (hi) test as well as in homologous radio ...19806155774
determination of the number of nonoverlapping antigenic areas on hong kong (h3n2) influenza virus hemagglutinin with monoclonal antibodies and the selection of variants with potential epidemiological significance. 19806156537
antineuraminidase antibody response to vaccination of chickens with intact virus and different submit preparations of the influenza virus strains a/sing/1/57 (h2n2), a/hong kong/1/68 (h3n2) and a/port chalmers/1/73 (h3n2).the antineuraminidase (an) antibody response to vaccination of chickens with intact virus and different subunit preparations of the influenza virus strains a/sing/1/57 (h2n2), a/hong kong/1/68 (h3n2) and a/pt. chalmers/1/73 (h3n2) was tested comparatively. using a photometric method capable of analysing mixtures of an antibodies against antigenically different n2 neuraminidases, it was concluded that vaccination with subunits produced by treatment with bromelain and sarkosyl can yield an antibod ...19806157375
[antigenic determinants in the makeup of the hemagglutinins of influenza virus type a (h3n2) isolated in 1977--1978].antigenic composition of hemagglutinins (ha) of influenza a viruses isolated during the epidemic of 1977--1978 was studied. three antigenic determinants of h3.1, h3.5 and h3.7, identical to the determinants of ha of the viruses isolated in 1975, were detected in ha of the viruses isolated in 1977--1978 by means o the hai test with inhibitor-free and monoreceptor sera. a/south australia/1/77 virus was an exception in this group of viruses, and its ha contained only two determinants, h3.5 and h3.7 ...19806158176
effect on influenza virus infection on the production of interferon by alveolar and peritoneal cells in vitro.the investigation was carried on mice infected with influenza a/053/74/h3n2 virus. 129/ao/boy, inbred mice, were inoculated intranasally with influenza virus. the alveolar and peritoneal cells from infected and uninfected animals were induced in vitro with newcastle disease virus. it was shown that the alveolar cells from infected mice produce more interferon than the cells from control mice, but the peritoneal cells from both groups of animals produced the same amount of interferon.19806158300
influenza vaccination in hbsag positive chronic active hepatitis patients treated with interferon.sixteen patients with hepatitis b antigen (hbsag) positive chronic active hepatitis (cah) were vaccinated with the nonhuman influenza a virus heq1neq1; eight patients were also treated with leucocyte interferon. pre-vaccination sera were negative for specific antibody in hemagglutination inhibition tests. four weeks after vaccination all patients had responded with a homologous antibody titer. between the interferon-treated and the untreated groups the differences in antibody titers against the ...19806162083
comparison of the antineuraminidase antibody response to vaccination with intact virus and subunit preparations obtained by different techniques of the influenza virus strains a/sing/1/57 (h2n2), a/hong kong/1/68 (h3n2) and a/port chalmers/1/73 (h3n2). 19806162604
antigenic and genomic analyses of influenza a(h1n1) viruses from different regions of the world, february 1978 to march 1980.antigenic analysis of influenza a(h1n1) virus isolates by hemagglutination inhibition reactions with postinfection ferret sera and mouse monoclonal antibodies showed that, although the predominant virus in 1978 to 1979 had an a/brazil/11/78-like hemagglutinin, several new antigenic variants could be detected which differed from those identified in 1977 to 1978. most of the variants showed very minor changes and did not achieve epidemiological significance. genome analysis by ribonucleic acid-rib ...19816163725
interferon production by human mononuclear leukocytes: differences between respiratory syncytial virus and influenza viruses.the ability of respiratory syncytial virus (rsv) to induce interferon production by human mononuclear leukocytes was compared with that of influenza viruses. cell culture fluids were assayed for interferon activity 1, 3 and 7 days after exposure to rsv or to one of two subtypes of influenza a virus (h0n1 and h3n2). rsv induced interferon production inconsistently and in low titers. varying the multiplicity of infection did not improve the ability of rsv to induce interferon production. in contra ...19816163726
antibodies to the strain-specific and cross-reactive determinants of the haemagglutinin of influenza h3n2 viruses. antiviral activities of the antibodies in biological systems.antibodies to the strain-specific (ss) and cross-reactive (cr) antigenic determinants of the haemagglutinin (ha) of influenza h3n2 viruses were prepared, and their antiviral properties in experimentally infected mice and in eggs were investigated. the ss antibodies were considerably more efficient than the cr antibodies in direct virus neuralization tests. the difference in the activities of the two types of antibody preparations was less pronounced in virus growth inhibition studies in the alla ...19806164247
antibodies to the strain-specific and cross-reactive determinants of the haemagglutinin of influenza h3n2 virus. 3. selection of antigenic variations in vitro and in vivo.antigenic variants of influenza a/hong kong/1/68 (h3n2) were obtained in vitro by letting virus multiply in the allantosis-on-shell system in the presence of anti-haemagglutinin antibodies, prepared from immune goat serum to purified haemagglutinin antigen, and in vivo by giving mice antibody intraperitoneally one day before challenge with a sublethal dose of live virus. in both systems it was shown that the most narrowly reacting strain-specific antibodies selected antigenic variants at an appa ...19806164248
haemagglutination-inhibition antibodies in human sera to an antigenic mutant of influenza a/texas/1/77 (h3n2) virus obtained in vitro.an antigenic mutant of the wild influenza strain a/texas/1/77 (h3n2) was obtained in vitro by growing virus of the allantosis-on-shell system in the presence of a mouse monoclonal antibody preparation to the texas haemagglutinin (ha) antigen. a total of 204 human sera, from a population of randomly collected sera during the fall of 1979, were examined by the haemagglutination-inhibition (hi) tests against the texas wild strain and the antigenic mutant. it was shown that sera from young children ...19806164249
the mechanism of antigenic drift in influenza viruses: analysis of hong kong (h3n2) variants with monoclonal antibodies to the hemagglutinin molecule.monoclonal antibodies to the hemagglutinin molecule of the hong kong variant, mem/1/71 (h3n2), influenza virus were used to study antigenic drift in the h3n2 subtype of influenza viruses. antigenic variants of mem/1/71 (h3n2) were selected after a single passage of the virus in chick embryos in the presence of monoclonal antibody. the variants showed a marked reduction in the ability to react with the monoclonal antibody used in selection. the monoclonal antibodies could be divided into three gr ...19806164328
the relation of interferon and nonspecific inhibitors to virus levels in nasal washes of ferrets infected with influenza viruses of differing virulence.two clones (7a, virulent; 64d, attenuated) of a recombinant influenza virus (a/pr/8/34-a/england/939/69 (h3n2)) were inactivated at the same rate by viral inhibitors present in nasal washes taken from both clone 7a- and clone 64d-infected ferrets. both clones induced similar levels of interferon in the nasal washes of infected animals. the onset and rise of interferon production occurred at the same time for both clones, and was associated with a decline in virus titres. in addition, both clones ...19816164382
in vitro antibody response to influenza virus. ii. specificity of helper t cell recognizing hemagglutinin.intraperitoneal immunization of mice with liver influenza virus was shown to induce helper t (th) cells with specificity for the hemagglutinin (ha). the interaction of virus-primed th cells with purified ha was studied independently of b cell reactivity to the same antigen by using the generation of nonspecific help as an index of activation of ha-specific th cells. th cells from mice primed with any of the h3 viruses a/aichi/68 x a/bel/42 (h3n1), a/memphis/102/72 x a/bel/42 (h3n1) or a/port cha ...19816166681
mechanism of antigenic drift in influenza virus. amino acid sequence changes in an antigenically active region of hong kong (h3n2) influenza virus hemagglutinin. 19816167724
[new antigenic determinant in the makeup of influenza type a(h3n2) virus hemagglutinins].influenza a (h3n2) viruses isolated during 1979 influenza epidemic are characterized by the presence in their hemagglutinins of both antigens similar to those found in previous isolates of the same type and a qualitatively new antigenic determinant also found in the hemagglutinin of h/south australia/1/77 virus.19816168113
[ability of influenza virus strains to induce interferon and their sensitivity to the action of exogenous interferon].investigation of 112 influenza a (h1n1 and h3n2) virus strains isolated in different years demonstrated their different interferon-inducing activity. the detection of strain differences in the process of interferon production is very important for the study of influenza infection pathogenicity. of special importance are the studies of influenza virus strain sensitivity to the effect of exogenous interferon. overcoming of resistance to interferon is important for effective influenza control. the ...19816168114
genome analysis of influenza a virus strains isolated during an epidemic of 1979-1980.the genome and polypeptides of influenza a virus h3n2 strains isolated during the epidemic of 1979-1980 in the u.s.s.r. and g.d.r. have been analysed. five varieties of h3n2 strains differing in a number of genes have been found. the isolates of the first group was similar to the a/texas/1/77 strain in all the genes; the isolates of the second group were similar to the a/bangkok/1/79 strain in all the genes; the strain representative of the third variety, contained all the genes except gene 4 cl ...19816171610
antigenic and genetic analysis of a/hong kong (h3n2) influenza viruses isolated from swine and man.two h3n2 strains of influenza a virus isolated from pigs in japan and thailand were characterized antigenically and genetically. a/swine/wadayama/5/69 (isolated in japan in 1969) was antigenically similar to a human strain, a/aichi/2/68, while a/swine/bangkok/9/78 (a swine isolate in thailand) was closely related to a/bangkok/36/78, a contemporary human isolate. gel electrophoresis and oligonucleotide mapping of the virus rna revealed genetic similarity between a/swine/wadayama/5/69 and a/aichi/ ...19816171614
[characteristics of the antigenic composition of influenza a (h3n2) virus hemagglutinins isolated 1979-1080].the results of comparative immunological analysis of epidemic influenza virus strains of 1979-1980 indicate an emergence in the antigenic composition of virus hemagglutinins of two qualitatively new antigenic determinants differing from those of previously investigated influenza h0n1, h1n1, h2n2, h3n2 viruses. it is suggested that the viruses of recent years having completely lost the relationship with the ancestor of the h3n2 subtype and having very little similarity with viruses occuring in 19 ...19826176071
anti-influenza response achieved by immunization with a synthetic conjugate.the peptide corresponding to sequence 91--108 of the hemagglutinin of type a h3n2 influenza virus has been synthesized by the solid-phase peptide synthesis method and covalently attached to several macromolecular carriers. the conjugate with tetanus toxoid was used for immunization of rabbits and mice. the immunoglobulin fraction of the rabbit antiserum showed the presence and antipeptide antibodies by both agar gel diffusion and radioimmunoassay. in the latter assay, the antibodies showed marke ...19826176996
killer t cell responses to influenza a during a drift period: studies in mice.after intravenous immunization of mice with any influenza a h3n2 drift strain attempts to restimulation of cytotoxic t cell (ctl) activities with the same virus or other drift period variants were unsuccessful for up to 6 weeks. cross-stimulation 4-5 months after primary sensitization yielded, in most situations, positive but lower--as compared to primary--secondary cytotoxic t cell responses. homotypic challenge was also effective after priming with some influenza a subtypes (a/e/72, a/pc/73, a ...19826178951
mapping of antigenic changes in the haemagglutinin of hong kong influenza (h3n2) strains using a large panel of monoclonal antibodies.a panel of 125 monoclonal antibodies (igg) was raised against the haemagglutinin of an early representative of the hong kong (h3n2) subtype of influenza. they were classified into groups based on their cross-reactions with 16 other virus strains from the same subtype. this classification was performed using methods of numerical taxonomy. statistical tests supported the validity of the grouping. ten such groups were identified. nine antibodies remained unclassified. the locations on the haemagglu ...19826182265
the possible origin h1n1 (hsw1n1) virus in the swine population of japan and antigenic analysis of the isolates.virus isolation and serological studies on swine sera collected during 1973 to 1978 showed that h1n1 (hsw1n1) influenza viruses first appeared in the swine population of japan about may 1977. with the exception of one strain, both haemagglutinin and neuraminidase subunits of all the h1n1 viruses isolated from swine in japan and from pigs imported from north america were antigenically indistinguishable from those of a/nj/8/76 virus, suggesting the introduction of swine influenza virus into japan ...19826182266
influenza in the united kingdom 1977-1981.the laboratory surveillance of influenza in the uk has continued to demonstrate the regularity of influenza outbreaks each winter even in the absence of increase in the other indices which reflect the morbidity and mortality associated with influenza. the period of five years from 1976 to 1981 has seen the appearance of a second sub-type of influenza. a with the return of the historic h1n1 virus; and the continued circulation of h3n2 concurrently with h1n1 virus. variants of both these influenza ...19826177743
analysis of the genome structure of influenza a virus strains isolated during the epidemics of 1977-1980.the genome structure of different a(h1n1) and a(h3n2) influenza virus strains isolated from 1977 to 1980 was analysed by electrophoresis of single-stranded rna and of the double-stranded rna obtained by hybridization with complementary rna of the a/stavropol 188/79 (h3n2) strain. the differences in genome structure are insignificant within the a(h1n1) subtype, and considerable (involving almost all the 8 rna fragments) between the two a(h3n2) strains (a/texas 1/77 and a/stavropol 188/79). the gr ...19826183817
human influenza a viruses in pigs: isolation of a h3n2 strain antigenically related to a/england/42/72 and evidence for continuous circulation of human viruses in the pig population.an influenza virus strain isolated in northern italy in 1977 was identified as belonging to the h3n2 subtype (a/swine/italy/1850/77). a close antigenic relationship to the human strain a/england/42/72 was demonstrated. serologic surveys of 548 pig sera from 53 farms in two provinces in northern italy demonstrated the existence of antibodies to the swine/italy/1850/77 strain and to a/hong kong/1/68, a/victoria/3/75 and h 1 n 1 (hsw 1 n 1) strains in the pig population.19826184032
[antigenic characteristics of different variants of influenza virus a(h3/n2) and their circulation in the ussr and people's republic of bulgaria in 1968-1980].influenza a (h3n2) virus strains isolated in 1968-1980 in the ussr (1908 strains), prb (1413 strains) and in other countries were studied comparatively. among 15 drift variants described in the literature only 6 were found to have sequential epidemic spread. in all the instances the epidemics occurred after importation of the virus from abroad, the interval between the emergence of a new drift variant and its detection in the study areas ranged from 2 1/2 months to 1 1/2 years and was not synchr ...19826186088
effect of influenza a virus on leukocyte histamine release.viral respiratory infections provoke asthma in many patients. in the following study we examined the effect of an in vitro incubation of influenza a on leukocyte histamine release. after incubation with a live influenza a (h3n2) virus, calcium ionophore a23187 (0.5, 1.0, and 1.5 microgram/ml)-induced leukocyte histamine release (hr) was enhanced (p less than 0.05). this effect was also found with heat- or ether-inactivated virus. similarly, influenza a-exposed leukocytes had augmented leukocyte ...19836187791
[antiviral action of swine leukocyte interferon in mouse experiments].swine leukocytes had previously been found to produce interferon which has an antiviral effect not only in swine cells but also in human cells. preliminary experiments in tissue cultures showed the culture of primarily trypsinized mouse embryo fibroblasts to be as sensitive to swine interferon as human diploid cells. the experiment studying the antiviral effect of swine leukocyte interferon in the animals demonstrated it to protect mice against the pathogenic a/aishi/68 (h3n2) strain; with a red ...19816171098
defective in vitro production of influenza virus-specific cytotoxic t lymphocytes in ataxia-telangiectasia.peripheral blood mononuclear cells (pbmc) from patients with ataxia-telangiectasia (a-t) were studied for their capacity to proliferate and to generate influenza virus-specific cytotoxic t lymphocytes (ctl) after in vitro stimulation with influenza a/hong kong (a/hk (h3n2)) virus. pbmc from 11 patients proliferated poorly to a/hk and 10 of the 11 patients failed to exhibit significant ctl effector activity when tested on influenza a/hk virus-infected autologous target cells. in contrast, pbmc fr ...19836189897
surveillance of influenza in houston, texas, usa: gradual transition from a/victoria/75 (h3n2) to a/texas/77 (h3n2) predominance and antigenic characterization of "intermediate" strains.influenza epidemics in houston, texas, usa, during the winters of 1975-76, 1976-77, and 1977-78 were attributed to a/victoria/3/75 (h3n2), b/hong kong/5/72, and a/texas/1/77 (h3n2)-like viruses, respectively. both a/victoria and a/texas viruses were detected towards the end of the 1976-77 epidemic and throughout the 1977-78 epidemic. to determine if there had been a gradual transition in the predominant strain, 267 viral isolates from the 1975-76 epidemic were tested for a/texas virus. eight spe ...19836190585
the presence of two neuraminidases in an influenza virus.the wild type influenza strain a/aichi/2/68 (h3n2), when disrupted with sds and electrophoresed on cellulose acetate paper, yielded two separate neuraminidases, na(h+) and na(h-). these enzymes after extraction were biologically active and possessed different specific activities. enzyme na(h+) possessed neuraminidase as well as hemagglutinin activities whereas enzyme na(h-) demonstrated only neuraminidase activity. similar results were obtained when the aichi strain was treated with tween-ether ...19806157463
mechanism of interferon action iii--significance of pppa2'p5'a2'p5'a in the antiviral action of interferon.this paper is to evidence that the antiviral effect of pppa2'p5'a2'p5'a(2'-5'p3a3) could cover a wide spectrum of viruses, the rna viruses such as influenza h3n2/77, influenza h1n1/77, echo11, rhino, sendai, sindbis and vsv, and the dna viruses such as herpes (type i). in addition, the antiviral effect of 2'-5'p3a3 on echo11 virus, as compared with other viruses, is more efficient than that of ifn. it seems likely that 2'-5'p3a3 plays an important role in the antiviral action of ifn. after compa ...19836194560
influence of interferon induction with influenza a virus upon the modification of anti-srbc humoral response.the investigations carried out showed the dependence of immunosuppression induced by a/usrr/053/74(h3n2) virus upon the activity of its neuraminidase. high activity of this enzyme influenced interferon (ifn) induction which, in turn, reduced the primary humoral response to sheep red blood cells (srbc) or stimulated the production of igm and igg antibody producing cells.19836197038
analysis by monoclonal antibodies of h3n2 subtype influenza a viruses in japan and southeast asia prior to 1983. 19836197497
from the national institutes of health. summary of a meeting on the origin of pandemic influenza viruses.influenza type a virus periodically undergoes major antigenic shifts in which the hemagglutinin (hag) and sometimes the neuraminidase (na) antigens are replaced by hag and na antigens of another subtype. three such shifts have taken place since the virus was first isolated, and all appear to have occurred in china. the way in which these "new" influenza type a viruses suddenly appear (or reappear) in the human population is not known. at a meeting held in beijing, china, on november 10-12, 1982, ...19846198405
most influenza a virus-specific memory cytotoxic t lymphocytes react with antigenic epitopes associated with internal virus determinants.this paper shows that most murine (c57bl/6) influenza a virus-specific memory cytotoxic t lymphocyte (ctl) clones tested in limiting dilution did not react with the influenza a virus surface glycoproteins, hemagglutinin (ha) and neuraminidase (na). this lysis of syngeneic target cells infected with the influenza a virus strains, aichi (h3n2), pr8 (h1n1), or recombinant strain x31 (h3n2) indicates that most antigenic epitopes recognized are associated with internal virus determinants. x31 and pr8 ...19846198430
antigenic characteristics and genome composition of a naturally occurring recombinant influenza virus isolated from a pig in japan.we performed antigenic analysis of the haemagglutinin and neuraminidase subunits of a recombinant virus (a/swine/kanagawa/2/78) isolated from a pig in japan in 1978, using a series of monoclonal antibodies to h1 (hsw1) haemagglutinin and n2 neuraminidases of h2n2 and h3n2 viruses. results obtained in haemagglutination inhibition tests with five monoclonal antibodies to the haemagglutinin of a/nj/8/76 (h1n1) revealed that the haemagglutinin of three h1n1 and the recombinant viruses were indisting ...19836198440
suppression of influenza virus replication in infected mice by protease inhibitors.administration of the protease inhibitors, epsilon-aminocaproic acid or aprotinins, to mice infected with mouse-adapted influenza virus strain a/pr/8/34 (hon1) and a/aichi/2/68 (h3n2) reduced virus replication in the lungs. up to 100-fold reduction of virus titre and virus-induced neuraminidase activity were revealed in mouse lungs under protease inhibitor treatment. as a result, drug-treated mice rapidly cleared the virus from their lungs. the predominant synthesis was of non-infectious virions ...19846198446
recognition of influenza a virus nucleoprotein by an h-2-restricted cytotoxic t-cell clone.cytotoxic t-cell clones raised against x-31 (h3n2) influenza virus in c57bl/6 mice can be directed against an influenza a virus subtype specific determinant (1). a representative t-cell clone (a3.1) has been used in combination with a set of genetically typed recombinant viruses, to show that the a/pr/8/34 nucleoprotein can be responsible for cytotoxic t-lymphocyte recognition of infected target cells.19846200990
[combined use of interferon inducers and recombinant influenza viruses for protection from the disease].the data on the use of national interferon inducers ( polyguacyl and double-stranded rna) in combination with original h1n1 and h3n2 influenza viruses and recombinant strains with the same antigenic properties in laboratory animals are presented. recombinants were found to produce a more marked effect: 3--6-fold increased protection of mice depending on the interferon inducer, higher titres of interferon and antibody, than the original influenza viruses. a simultaneous use of interferon inducers ...19846203227
an antigenic map of the haemagglutinin of the influenza hong kong subtype (h3n2), constructed using mouse monoclonal antibodies.panels of monoclonal antibodies were raised to the haemagglutinin of strains of the hong kong subtype of influenza (h3n2), namely hong kong 1968, england 1972, port chalmers 1973, victoria 1975 and texas 1977. the probable binding sites of individual antibodies in each panel were determined by correlation of cross-reactivity with 16 heterologous strains from the same subtype, and amino acid differences between their haemagglutinin molecules. this led to an approximation of the "average repertoir ...19846205255
metaplasia of the lung respiratory epithelium and antibody dynamics in mice repeatedly infected with various subtypes of influenza virus a.mice were repeatedly infected with consecutive doses of mouse-adapted strains of influenza virus a hon1, h1n1, h2n2, and h3n2. homo- and heterologous antibody levels as well as the incidence of metaplasia were followed. statistically significant correlation was found between the metaplasia incidence and higher level of antibodies homologous to virus used for a given challenge dose.19846205549
the dynamics of serum antibodies and metaplasia of the lung respiratory epithelium in influenza-virus-preimmunized mice subjected to immunosuppression.mice preimmunized with influenza virus a scotland 840/74 h3n2 were given cyclophosphamide or hydrocortisone, then challenged with the same active virus. serum antibody levels and metaplasia of the respiratory epithelium were followed for the next two weeks. administration of the immunosuppressors was found to decrease antibody levels, and to delay the appearance of metaplasia by 7 days as compared with controls.19846205551
the influenza a virus nucleoprotein gene controls the induction of both subtype specific and cross-reactive cytotoxic t cells.using genetically typed recombinant influenza a viruses that differ only in their genes for nucleoprotein, we have demonstrated that repeated stimulation in vitro of c57bl/6 spleen cells primed in vivo with e61-13-h17 (h3n2) virus results in the selection of a population of cytotoxic t lymphocytes (ctl) whose recognition of infected target cells maps to the gene for nucleoprotein of the 1968 virus. influenza a viruses isolated between 1934 and 1979 fall into two groups defined by their ability t ...19846206181
[inhibition of the hemolytic activity of influenza viruses by antibody].haemolysis caused by influenza viruses is known to occur below ph 6; the ph-optimum for each virus strain is different. clear dose-effect correlations were found to prevail between the amount of haemolysis and virus concentration. antibody-mediated inhibition of haemolysis has been investigated with the strain a/pr/8/34 (h1n1) and the recombinant x-73 (h3n2). inhibition of haemolysis by antisera against different influenza. a virus subtypes suggests that haemolysis inhibiting antibodies are not ...19846207814
antigenic analyses of influenza virus haemagglutinins with different receptor-binding specificities.monoclonal antibodies were used to compare the antigenicities of the haemagglutinins of two receptor binding mutants of x-31 (h3n2) influenza virus. the mutants which differed from each other in recognizing sialic acid in either alpha 2-6 linkage or alpha 2-3 linkage to galactose also differed exclusively at residue 226 of the ha1 polypeptides of their haemagglutinins (g. n. rogers, j. c. paulson, r. s. daniels, j. j. skehel, i. a. wilson, and d. c. wiley, nature (london) 304, 76-78, 1983). the ...19846208680
comparative study and grouping of nonstructural (ns1) proteins of influenza a viruses by the method of oligopeptide mapping.oligopeptide mapping of 35s-methionine labeled non-structural (ns1) proteins of 23 influenza. a virus strains showed the presence of both common and variable oligopeptides. analysis of the oligopeptide maps revealed at least four groups of ns1 proteins. the first group includes ns1 proteins of several human h1n1 influenza viruses (that were designated as h0n1 according to the old classification). the second group is composed of ns1 proteins of h1n1 and h2n2 viruses. the third group includes ns1 ...19836229233
[circulation of influenza a virus (h3n2) and its role in the occurrence of epidemics 1976-1981].in 1976-1981 the etiology of influenza epidemics was mixed, influenza viruses a(h3n2), a(h1n1) and b taking part in them simultaneously. the active circulation of influenza virus strains with different antigenic structures was established: influenza virus a(h3n2) circulated in 1976, and since november 1977 simultaneous spread of influenza viruses a(h3n2) and a(h1n1) was observed, the epidemic activity of strain a(h3n2) being noticeably decreased during this period; in the autumn and winter month ...19846231786
[characteristics of the causative agents of the influenza a (h3n2) epidemic in leningrad in 1983].investigation of influenza a (h3n2) epidemic of 1983 in leningrad revealed simultaneous circulation of 3 antigenic variants similar to a/bangkok/1/79, a/bangkok/2/79, and a/philippines/2/82 with significant predominance of the first antigenic variant. the viruses related to a/philippines/2/82 comprising one-third of all isolations produced antibodies of a wide spectrum unlike the other two variants whose antisera neutralize actively the homologous virus only. the possibility of selecting epidemi ...19846235673
cloning dna sequences from influenza viral rna segments.dna sequences corresponding to gene segments that code for the nonstructural protein, the matrix protein, and the hemagglutinin of influenza a virus [strain a/udorn/72 (h3n2)] were cloned in escherichia coli pbr 322. initially, positive and negative cdna strands were prepared separately by reverse transcription. the positive strands of cdna were transcribed from genomic rna segments by using a specific dodecamer dna sequence as a primer; the negative strands of cdna were transcribed from cytopla ...19806244544
reassortant virus derived from avian and human influenza a viruses is attenuated and immunogenic in monkeys.an influenza a reassortant virus that contained the hemagglutinin and neuraminidase genes of a virulent human virus, a/udorn/72 (h3n2), and the six other influenza a virus genome segments from an avirulent avian virus, a/mallard/new york/6750/78 (h2n2), was evaluated for its level of replication is squirrel monkeys and hamsters. in monkeys, the reassortant virus was as attenuated and as restricted in its level of replication in the upper and lower respiratory tract as its avian influenza virus p ...19826183749
[correlations of the antigenic specificity of human blood with the levels of antihemagglutinins to influenza viruses].the results of the observations show that after active circulation of influenza a (h1n1), a (h3n2), and b viruses the degree of immune response (a rise in antihemagglutinin titres to the causative agent of an epidemic) differed significantly in subjects with different blood groups of the abo(h) system. after active circulation of influenza a(h1n1) and a(h3n2) viruses, rises in the antibody titres to the etiological factor of the epidemic was more marked in subjects with blood groups o and a than ...19836189297
antigenic drift in influenza virus h3 hemagglutinin from 1968 to 1980: multiple evolutionary pathways and sequential amino acid changes at key antigenic sites.surveys of the antigenic properties of a wide range of variants of the h3n2 (hong kong) influenza virus subtype have revealed complex patterns of variants cocirculating during each of the main epidemic eras of the subtype. we determined hemagglutinin (ha) gene sequences for 14 isolates chosen to give the wildest possible spread of variant types. the addition of these data to existing ha gene sequence information for other variants provides a comprehensive picture of ha gene evolution during anti ...19836193288
isolation of a recombinant influenza virus (hsw 1 n2) from swine in japan.outbreaks of swine influenza were first observed in japan in 1978. a number of influenza viruses were isolated from diseased swine. almost all viruses isolated were swine influenza virus (hsw 1 n1) but two viruses isolated from the nasal swabs of swine showing clinical signs of influenza in the kanagawa prefecture were characterized antigenically as hsw 1 n2. analysis of swine sera showed that influenza virus hsw 1 n2 was epidemic in the farm from which the virus had been isolated. the new virus ...19806255900
virus infection of endothelial cells.endothelial injury is important in the pathogenesis of thrombosis, atherosclerosis, disseminated intravascular coagulation, and vasculitis. the ability of several common human viruses to infect cultures of endothelial cells obtained from human umbilical veins or bovine thoracic aorta was demonstrated. indicators of infection included cytopathology, viral growth curves, and antigen detection by immunofluorescence. herpes simplex virus type 1, adenovirus type 7, measles virus, and parainfluenza vi ...19816260874
investigations concerning the cultivation of myxo- and paramyxoviruses on chorioallantoic membrane fragments. note i. data on the multiplication of several myxo- and paramyxoviruses.influenza viruses a(h1n1) and a(h3n2) and parainfluenza viruses (sendai mumps) were cultivated in chorioallantoic membrane (cam) fragments maintained in media with different formulae, with or without daily medium changes, in roller or stationary tubes. inoculation was performed either directly on cam fragments in petri dishes or by dilution of the virus-containing material in the medium. infectant titers obtained in cam fragments were similar to those recorded in embryonated eggs at 48 hours pos ...19816264662
functional expression in primate cells of cloned dna coding for the hemagglutinin surface glycoprotein of influenza virus.we have used simian virus 40 (sv40) dna as a vector for expression of functional activity of a cloned influenza viral dna segment in primate cells. cloned full-length dna sequences coding for the hemagglutinin of influenza a virus (udorn/72/[h3n2]) were inserted into the late region of a viable deletion mutant of sv40, and the hybrid dna was propagated in the presence of an early sv40 mutant (tsa28) helper. infection of primate cells with the hybrid virus produced a polypeptide similar in molecu ...19816272305
evidence of prior infection with influenza a/texas/77 (h3n2( virus in dogs with clinical parainfluenza.eighty dogs exhibiting clinical signs of respiratory disease were sampled for influenza virus isolation and serologically tested for hemagglutination inhibiting antibody to influenza a/hong kong/68, a/victoria/75, a/texas/77 and a/ussr/77. forty-one animals without clinical signs of respiratory disease were also examined serologically. hemagglutinating agents were isolated from nasal and/or pharyngeal swabs taken from 21 of the 80 dogs with clinical respiratory disease. twenty of these 21 isolat ...19806256039
lack of interference of guanosine with ribavirin aerosol treatment of influenza a infection in mice.guanosine or guanosine 5'-monophosphate did not reduce the protective effect of ribavirin aerosol in influenza virus a/aichi/68 h3n2 infection of mice. both compounds partially interfered with the action of a wide range of ribavirin concentrations against influenza virus a/wsn replication in cell culture.19816282193
serological studies on swine influenza in egypt.480 pig serum samples collected from november 1979-october 1980 and 200 human sera collected in the same period, nearly have been used in serological investigations. 52.5% sera were positive against swine influenza (hsw1n1) 10% only of human sera were positive against (hsw1n1) virus. by using (h3n2) human virus, 10.4% of pig sera were positive, while 41% of human sera were positive against this virus.19816282772
the follow-up study of swine and hong kong influenza virus infection among japanese hogs.pigs in miyagi prefecture, japan were examined for swine (hssw1n1) and hong kong (h3n2) influenza virus infection by serological tests. the results obtained revealed that a swine influenza was prevalent with relatively high positive ratios throughout that time, and that the hong kong influenza virus closely related to a recent human epidemic strain, a/yamanashi/2/77, also persisted, corresponding to a human endemic. these epidemiological findings strongly suggested the possibility of direct tran ...19826285546
[effect of influenza epidemics on acute respiratory morbidity of noninfluenzal etiology].the use of correlation analysis has made it possible to reveal a high degree of influence exerted by influenza epidemics on morbidity rate in adenoviral, respiratory-syncytial, parainfluenza and mycoplasmic infections among the population. during the months of influenza epidemic considerable concomitant incidence of respiratory-syncytial, adenoviral and especially mixed infections was observed in all age groups in comparison with periods free from influenza epidemic. the study of concomitant mor ...19836308927
zoonotic studies on influenza in pigs and birds, india, 1980-81.five hundred and twenty pig sera collected from pune, maharashtra state, india during 1980 were examined in haemagglutination inhibition (hi) tests to determine the antibody prevalence to nine human influenza virus strains covering the subtypes a(hon1), a(h1n1), a(h2n2), a(h3n2), type b and one swine influenza virus strain a(hsw1n1). this study indicated considerable prevalence of antibodies to the four h3n2 strains isolated from 1973 onwards, particularly to the two recent h3n2 strains, limited ...19836315619
lung alterations in guinea-pigs infected with influenza virus.guinea-pigs were infected intranasally with influenza a hong kong 68 (h3n2) virus. infective particles were re-isolated from lung homogenates up to 3 days after inoculation and indicated local replication. the subsequent lung inflammatory stages were studied by light microscopy, scanning and transmission electron microscopy (tem). lung alterations appeared after 24 h and intensified up to 7 days after virus inoculation, progressively decreasing until 3 weeks thereafter. the damage was reversible ...19846330181
distribution of viral antigen with the lower respiratory tract of ferrets infected with a virulent influenza virus: production and release of virus from corresponding organ cultures.using fluorescent antibody techniques, a semi-quantitative survey has been made of the distribution of influenza virus antigen in the trachea, main bronchi, and three zones (hilar, intermediate and alveolar) of all four lung lobes of ferrets following intranasal inoculation of a virulent clone (7a) of the recombinant influenza virus a/pr/8/34-a/england/939/69 (h3n2). the results confirm the indications from our previous quantitative surveys of infectious virus and histological damage in these ar ...19836338151
Displaying items 701 - 800 of 4452