| temperature-sensitive mutants of influenza a virus: transfer of the two temperature-sensitive lesions in the udorn/72-ts-1a2 virus to the a2hong kong/123/77 (h1n1) wild-type virus. | the influenza a/udorn/72-ts-1a2 virus possesses temperature-sensitive mutations in the genes coding for the p1 and p3 polymerase proteins. it is being evaluated as a donor of its attenuating temperature-sensitive genes to produce recombinant live vaccine strains of epidemic variants of influenza a virus. transfer of the p1 and p3 genes to two viruses within the h3n2 subtype of influenza a virus (i.e., the a/victoria/3/75 and a/alaska/6/77 viruses) conferred on each variant the following properti ... | 1980 | 7399695 |
| naturally occurring temperature-sensitive influenza a viruses of the h1n1 and h3n2 subtypes. | seventeen of twenty-six influenza a virus isolates of the h1n1 antigenic subtype and two of eleven h3n2 virus isolates from the 1977-78 season exhibited a ts phenotype, were restricted in plaquing in mdck cells at 38.5 degrees c compared to 34 degrees c and appeared to be naturally occurring ts mutants. the cut-off temperature for two such ts h1n1 virus isolates was established as 38 degrees c. the ts viruses were as thermostable as non-ts isolates and no complementation was detected between the ... | 1980 | 7400776 |
| [features of strains of a(h3n2) influenza virus isolated during the 3 epidemics of kiev in 1972-7976]. | | 1980 | 7402112 |
| antibody response to influenza a/new jersey and a/victoria virus vaccines in 1976 and subsequent antibody levels after influenza a epidemics, 1977-1979. | antibody levels before and after vaccination were studied among schoolchildren and young adults given commercial a/new jersey/76 (hswn1), a/victoria/75 (h3n2), and b/hong kong/72 vaccines in the fall of 1976. children responded better to a single dose of the a/new jersey subvirion vaccine than had previously been observed, particularly to a new subvirion vaccine. hemagglutination-inhibiting antibody titers decreased during the first six months after vaccination but appeared stable thereafter. pe ... | 1980 | 7410896 |
| electrophoretic migration rate differences of polypeptides of human influenza a viruses: partial analysis of the genome of influenza vaccine recombinant viruses. | electrophoretic migration rate differences were detected in high resolution sds polyacrylamide gels for nucleoprotein (np), matrix protein (m), non structural protein (ns1), haemagglutinin (ha) annd, less regularly, for the polymerase polypeptides p1, p2 and p3 induced by different influenza a viruses. the technique allowed parental assignation of the corresponding genes in certain recombinant viruses including a/pr/8/34 (h0n1)--a/hk/117/77 (h1n1), a/okuda/57 (h2n2)--a/hk/119/77 (h1n1) and a/len ... | 1980 | 7416971 |
| [study results of the comprehensive influenza prevention with vaccines and remantadine during the influenza a(h1n1) outbreak in 1979]. | during an outbreak of influenza in april, 1979, caused by a (h1n1) virus the protective effect of remantadine in combination with vaccinations using a national-made live a (h3n2) and inactivated a (h1n1) and b vaccines was studied. the best protective effect was achieved in the subjects vaccinated with influenza vaccines and given remantadine for urgent prophylaxis. vaccination prophylaxis reduced the incidence of influenza and ard 1.4-fold, prophylaxis with remantadine alone 2.3-fold. | 1980 | 7423970 |
| temperature-sensitive mutants of influenza a virus: evaluation of the alaska/77-ts-1a2 temperature-sensitive recombinant virus in seronegative adult volunteers. | an influenza a virus recombinant bearing the surface antigens of the a/alaska/6/77 (h3n2) wild type virus ands the two ts genes of the a/udorn/72-ts-1a2 (h3n2) virus was evaluated for attenuation, antigenicity, and transmissibility in 28 adult volunteers all of whom possessed a preinoculation serum hemagglutination-inhibiting (hai) antibody titer of less than or equal to 1:8 and 18 of whom also possessed a serum neuraminidase-inhibiting (ni) antibody titer of less than or equal to 1:4. the alask ... | 1980 | 7425857 |
| temperature-sensitive mutants of influenza a virus. transfer of the two ts-1a2 ts lesions present in the udorn/72-ts-1a2 donor virus to the influenza a/alaska/6/77 (h3n2) wild type virus. | the udorn/72-ts-1a2 temperature-sensitive influenza a virus has a 37 degrees c shutoff temperature and a ts mutation on the genes coding for the p1 and p3 proteins. this ts donor virus was produced with the expectation that the transfer of its two ts genes would regularly and predictably attenuate each new variant of influenza a virus. it had previously been mated with the a/victoria/75 (h3n2) virus and five vic/75-ts-1a2 rcombinants were isolated that had both ts-1a2 ts genes and in vitro and i ... | 1980 | 7425858 |
| a study of live influenza virus vaccine in patients with chronic bronchitis. report to medical research council's committee on influenza and other respiratory virus vaccines. advisory group on pulmonary function tests in relation to live influenza virus vaccines. | a multicentre study of the effects of influenza virus rit 4050 (h3n2) in patients with chronic bronchitis was conducted by members of an mrc committee. the results showed that rit 4050 vaccine virus did not cause a deterioration in clinical or physiological status in these patients within the limitation of the relatively reproducible ventilatory tests which were employed. this conclusion applied equally to those who were inoculated and became infected and to those who failed to develop serologic ... | 1980 | 7426351 |
| further studies of the neuraminidase content of inactivated influenza vaccines and the neuraminidase antibody responses after vaccination of immunologically primed and unprimed populations. | purified concentrates of influenza a/ussr/90/77(h1n1)-like, a/texas/1/77 (h3n2)-like, and b/hong kong/5/72-like viruses used for preparation of investigational and licensed vaccines in 1978 to 1979 were tested for their content of neuraminidase enzyme activity. concentrates of h1n1 virus used to prepare vaccines for clinical investigations performed in the spring of 1978 had neuraminidase activity at that time which decreased during storage to almost undetectable levels (three lots) or by 50% (o ... | 1980 | 7429641 |
| influenza vaccination of elderly persons. reduction in pneumonia and influenza hospitalizations and deaths. | effectiveness of influenza vaccination in reducing pneumonia and influenza hospitalizations and deaths among elderly members of a prepaid health plan was analyzed retrospectively. two epidemics caused by the h3n2 subtype of type a influenza were studied. vaccine derived from the h2n2 subtype of influenza a virus failed to protect against the hong kong (h3n2) virus during the 1968-1969 epidemic. vaccine derived from the a/hong kong/68 (h3n2) virus yielded an estimated 72% (31% to 100%) reduction ... | 1980 | 7431593 |
| [comparative study of the proteins of influenza virus type a nucleoproteins]. | a comparative study of protein of nucleoproteins (np-protein) of influenza a viruses by peptide mapping shows its variability to be small within one drifting series and quite marked in strains belonging to different sero-types. in oligopeptide maps of np-proteins of viruses of the hong kong (h3n2) series there is a typical group of spots differing them from oligopeptide maps of np-proteins of viruses of other serotypes, particularly of the preceeding serotype h2n2 and the viruses related by hema ... | 1980 | 7434735 |
| production of an attenuated influenza a (h3n2) strain "ko-1" by recombination with a/okuda/57 (h2n2) followed by selection of inhibitor-resistant virus. | a live attenuated influenza a (h3n2) strain "ko-1" was developed by recombination of wild influenza a/kumamoto/22/76 (h3n2) with attenuated a/okuda/57 (h2n2) followed by passage in developing chick eggs in the presence of horse serum inhibitor. the virus strain "ko-1" obtained is inhibitor-resistant, and has hemagglutinating (ha) and neuraminidase (na) antigenicity derived from the wild parent virus. rna analysis revealed that one rna segment (corresponding to m protein) was derived from the a/o ... | 1980 | 7437002 |
| relationship between surface antigens of two variants of influenza a (h3n2) virus, as revealed by hemagglutination inhibition, kinetic neutralization, and neuraminidase inhibition. | rabbit antisera were raised against plaque-purified influenza virus strains of a/victoria/75 and a/texas/77 isolated from seattle influenza patients. the antigenic specificity of hemagglutinins was compared by hemagglutination inhibition (hi) and kinetic neutralization tests. anti-a/victoria/75 had equally high hi titers and neutralization rate constants (kappa values) for a/victoria/75 and a/texas/77. in contrast, anti-a/texas/77 had a high hi titer and kappa value to a/texas/77 and a low hi ti ... | 1980 | 7439992 |
| duck influenza lacking evidence of disease signs and immune response. | influenza viruses a/duck/hokkaido/5/77 (hav7n2), a/budgerigar/hokkaido/1/77 (hav4nav1), a/kumamoto/22/76 (h3n2), a/aichi/2/68 (h3n2), and a/new jersey/8/76 (hsw1n1) were experimentally inoculated into pekin ducks. of these, the influenza viruses of duck and budgerigar origin replicated in the intestinal tract of the ducks. the infected ducks shed the virus in the feces to high titers, but did not show clinical signs of disease and scarcely produced detectable serum antibodies. using immunofluore ... | 1980 | 7439994 |
| correlation between antibody titers to influenza a virus subtypes h1n1 and h3n2 as measured by hemagglutination-inhibition and hemolysis-in-gel tests. | | 1980 | 7441011 |
| enhancement of activity against influenza viruses by combinations of antiviral agents. | in an investigation of alternative therapeutic approaches for the treatment of influenza virus infections, the antiviral activities of rimantadine hydrochloride, amantadine hydrochloride, ribavirin, and combinations of these drugs were assessed in vitro. madin-darby canine kidney cell monolayers were inoculated with recent isolates of influenza viruses at low multiplicities of infection, and virus titers were determined after 24 h. the combination of rimantadine and ribavirin resulted in an enha ... | 1980 | 7447417 |
| differing virulence of h1n1 and h3n2 influenza strains. | sequential influenza a/texas/77 (h3n2) and a/ussr/77 (h1n1) epidemics occurred during the winter of 1977-1978 in two populations under viral surveillance for influenza. in college students who reported to the vanderbilt student health service, roughly equivalent amounts of typical influenzal disease were documented by virus isolation and total health service visits with both strains. however, considering that the college population was fully susceptible to the first introduction of h1n1 virus in ... | 1980 | 7457472 |
| a study of excess mortality during influenza epidemics in the united states, 1968-1976. | the effect of epidemics of influenza a on mortality in the united states was assessed by studying the monthly numbers of deaths during the years 1968-1976. deaths from all causes at all ages and among persons aged 65 and over, and also deaths from acute respiratory diseases, and from cardiovascular causes were studied. deaths from acute respiratory diseases were closely correlated with those from influenza and were taken to be an indication of the severity of influenza outbreaks. this indicator ... | 1981 | 7457477 |
| strain specificity of serum antibody to the haemagglutinin of influenza a (h3n2) viruses in children following immunization or natural infection. | the specificity of serum anti-ha antibody from children immunized or infected with a/victoria/75 (h3n2 or a/texas/77 (h3n2) virus was examined using the single radial haemolysis test together with adsorption of antibody with three antigenic variants a/hong kong/68 (h3n2), a/port chalmers/73 (h3n2) and a/victoria/75 (h3n2). the majority of young children reacted to vaccination or infection by producing strain-specific (ss) antibody to the homologous virus. a small proportion of children's sera co ... | 1981 | 7462596 |
| protection of infants from infection with influenza a virus by transplacentally acquired antibody. | transplacentally acquired antibody to influenza a virus was measured by a microneutralization test and a radioimmunoprecipitation assay in cord blood obtained from infants at a large urban county hospital in 1975-1978. random samples tested before epidemic periods were a measure of susceptibility of the population. twenty-six infants from whom cord sera were available had culture-documented infections with influenza a/victoria (h3n2) virus when younger than four months. the direct correlation be ... | 1980 | 7462695 |
| studies with a cold-recombinant a/victoria/3/75 (h3n2) virus. i. biologic, genetic, and biochemical characterization. | a cold-recombinant virus cr 22, was derived from an attenuated cold-adapted parent strain. a/ann arbor/6/60 (h2n2), and a wild-type parent strain, a/victoria/3/75 (h3n2). antigenic analysis showed that cr 22 possesses the hemagglutinin and neruaminidase surface antigens derived from the a/victoria/3/75 (h3n2) parent. from studies of virus-induced polypeptides using polyacrylamide gel electrophoresis, it was deduced that a polymerase protein, p1, is coded and by an rna segment derived from the wi ... | 1980 | 7462696 |
| studies with a cold-recombinant a/victoria/3/75 (h3n2) virus. ii. evaluation in adult volunteers. | a cold-recombinant influenza a virus, cr 22, derived from a/ann arbor/6/60 (h2n2) cold-adapted virus and a/victoria/3/75 (h3n2) wild-type virus, was tested in adult volunteers. cr 22 induced only low-grade clinical reactions in volunteers who had low titers of serum antibodies. virus could be reisolated from about one-third of the volunteers, but only at low titers. no revertant viruses were found, and there was no evidence for transmission of virus to unvaccinated volunteers housed in the close ... | 1980 | 7462697 |
| defective interfering influenza viruses and host cells: establishment and maintenance of persistent influenza virus infection in mdbk and hela cells. | wsn (h0n1) influenza virus upon undiluted passages in different species of cells, namely, bovine kidney (mdbk), chicken embryo (cef), and hela cells, produced a varying amount of defective interfering (di) virus which correlated well with the ability of the species of cell to produce infectious virus. however, the nature of the influenza di viral rna produced from a single clonal stock was essentially identical in all three cells types, suggesting that these cells do not exert a great selective ... | 1980 | 7463559 |
| [influenza. sero-epidemiological supervision of the alitalia airline personnel (1978-1979)]. | from the autumn 1978 to the spring 1979 an epidemiological inquiry was set up concerning samplings of sera of 1648 adult of different ages and of both sexes. it was noticed a contemporaneous presence of a/texas/1/77(h3n2) and a/ussr/90/77(h1n1) viruses; it was found a larger frequency of the last subtype in the individuals born after 1957. during the winter 1978/1979 it was also noticed an overlap of b influenza virus. | 1980 | 7465100 |
| immunogenicity of influenza a virus n2 neuraminidase produced in insect larvae by baculovirus recombinants. | influenza a virus neuraminidase (na) from a/udorn/72 (h3n2) was expressed by recombinant baculovirus-infected insects. the recombinant na was enzymatically active. enzyme activity was neutralized by polyclonal antisera raised against virion-extracted na. na produced in whole insects by a baculovirus expression system is antigenically indistinguishable from virion na by polyclonal antisera in functional assays (ni) and in elisa, and is highly immunogenic without adjuvant. it is equivalent in immu ... | 1995 | 7483807 |
| increased immunogenicity of inactivated influenza virus vaccine containing purified surface antigen compared with whole virus in elderly women. | thirty-eight elderly female subjects (aged 80 +/- 7 years, mean +/- standard deviation) were randomized to immunization with trivalent inactivated influenza virus vaccine containing either purified surface antigen (n = 18) or whole virus (n = 20) components from a/texas/36/91 (h1n1), a/beijing/353/89 (h3n2), and b/panama/45/90 strains. humoral and cellular immune responses were assessed by measuring serum hemagglutination inhibition antibodies and cytotoxic t lymphocyte (ctl) activity at 0 and 3 ... | 1994 | 7496915 |
| sialoglycoproteins that bind influenza a virus and resist viral neuraminidase in different animal sera. | sialoglycoproteins that are resistant to degradation by viral neuraminidase can effectively neutralize influenza a viruses, because they bind irreversibly to the viruses. to detect such proteins in animal sera, we developed an immunochemical assay based on western blotting techniques. we assessed the binding activity of sialoglycoproteins in sera from nine different animals toward the a/aichi/2/68 (h3n2) and a/pr/8/34 (h1n1) strains of influenza virus, with or without viral and bacterial neurami ... | 1994 | 7517433 |
| alteration in the antigenic structure of m1 protein of influenza a virus mutant resistant to a new antiviral compound mopyridone. | using 14 monoclonal antibodies (moabs) in solid-phase elisa it was found that influenza virus a/hong kong/1/68 (h3n2) mutants resistant to the antiviral compound mopyridone as compared to the mopyridone-sensitive mutant manifested significant changes in the antigenic structure (sites 1a, 2 and 3) of m1 protein. no differences in m1 were found between rimantadine-resistant and rimantadine-sensitive mutants of influenza virus a(h3n2). | 1994 | 7520664 |
| [development of synthetic peptide vaccine against influenza--t cell epitope the hemagglutinin of a/aichi/2/68(h3n2) influenza virus induced immune response in mice]. | residues 46 and 54 of a synthetic peptide composed of residues 43-58 (aegfsytdanknkgit) of pigeon cytochrome c (p43-58) function as the agretope (the site of contact between the major histocompatibility complex and the antigen) and residues 50 and 52 function as the epitope (the site of contact between the t cell receptor and the peptide antigen). 46f54a peptide which was prepared by reserving phenylalanine (f) at an agretopic position 46 but substituting asparagine (n) to alanine (a) at the oth ... | 1994 | 7525436 |
| analysis of epitopic residues introduced into the hybrid peptide vaccines prepared according to the cassette theory. | in our previous study, we prepared a synthetic peptide vaccine (46f/ha127-133/54a) against influenza strain a/aichi/2/68 (h3n2) virus by introducing haemagglutinin (ha) 127-133 to an i-ab,b binding component that consisted of residues 43-46 and 54-58 of an i-ab,d binding peptide, 46f50v54a. this hybrid peptide vaccine induced considerable immunological responses against a/aichi/2/68 as well as against the peptide vaccine in i-ab mice. in the present study, we have attempted to increase the immun ... | 1994 | 7526571 |
| [influenza: current status and epidemiologic situation]. | in the period of 1993 to 1994, influenza activity caused by circulation of viruses antigenically structurally related to the strain a/beijing/32/92 (h3n2) began in the countries of north america and west europe in october-november 1993, by spreading to the countries of east europe, the urals, and west siberia. epidemic events in china and in the far east were evoked mainly by the influenza b virus. the influenza a (h1n1) viruses did not widely spread. single isolates (about 1% of all the influen ... | 1994 | 7532491 |
| [polymorphism of current human influenza a and b virus population]. | during the past years, the etiological situation has been significantly complicated. it is characterized by simultaneous circulation of a(h1n1), a(h3n2) and influenza b viruses and by the isolation of reassortant strains and viruses, which are atypical in relation to the process of their natural variability. the antigenic properties of epidemic strains and unusual isolates were investigated. the marked heterogeneity of the a(h3n2) influenza viruses was demonstrated. it was determined by the circ ... | 1994 | 7532493 |
| isolation of influenza a and b viruses in hela cells. | the hela cell line which is one of the most popular cell lines was shown to be suitable for isolation of types a (h3n2) and b influenza viruses from throat washings of patients. sixty-nine and 67 out of 147 throat washings taken from patients during the period from january to april 1994, were positive for influenza a virus in hela cells and mdck cells respectively. seven out of 10 throat washings taken between january and march, 1993, were positive for influenza b virus in mdck. of these 7, 4 we ... | 1995 | 7565177 |
| a fairly conserved epitope on the hemagglutinin of influenza a (h3n2) virus with variable accessibility to neutralizing antibody. | a monoclonal antibody lmbh5 was derived from mice which had been immunized with a/victoria/3/75 (h3n2)-type recombinant, secreted hemagglutinin (ha), and were subsequently challenged with a potentially lethal dose of x31 [a/aichi/2/68 (h3n2) x a/pr/8/34 (h1n1)] virus. lmbh5 reacted strongly with the native and low-ph-induced conformations of the ha of a/aichi (x31 strain) and a/victoria (x47 strain), but very weakly with the native structure of the ha of a/philippines/2/82 (x79 strain) and not a ... | 1995 | 7571422 |
| [the origin of resistance to chemicals of naturally occurring isolates of influenza a virus]. | the mechanisms responsible for the formation of resistance of influenza a virus isolates during the natural circulation of the influenza viruses in the environment were studied. the influenza viruses h1n1 and h3n2 resistant to remantadine, adapromine, and deitiforine have been isolated in the ussr and mongolia since 1982. the majority of natural resistant isolates appeared to be atypical both in antigenic properties and genomic structure as compared to the isolates prevalent in the common epidem ... | 1995 | 7580412 |
| [features of interepidemic influenza a and b viruses]. | the comparison of interepidemic influenza viruses with the pathogens of resultant influenza epidemics has revealed that they belong to the same type (subtype) of influenza virus. a definite correlation has been found between the antigenic specificity of haemagglutinin of epidemic and interepidemic strains. the antigenic structure of the interepidemic viruses and the pathogens of further epidemics of influenza b viruses have been found to be completely identical. the interepidemic a(h1n1) isolate ... | 1995 | 7580419 |
| prolonged shedding of amantadine-resistant influenzae a viruses by immunodeficient patients: detection by polymerase chain reaction-restriction analysis. | consecutive a (h3n2) influenza virus isolates from 2 influenza virus-infected immunodeficient patients treated with amantadine were examined using a novel polymerase chain reaction (pcr)-restriction analysis for resistance to this antiviral compound. the data indicate that immunodeficient patients may shed resistant viruses for prolonged periods and with different drug resistance mutations present at different times. this pcr-restriction technique allows rapid detection of amantadine- or rimanta ... | 1995 | 7594676 |
| selection of a single amino acid substitution in the hemagglutinin molecule by chicken eggs can render influenza a virus (h3) candidate vaccine ineffective. | this study investigated whether a single amino acid change in the hemagglutinin (ha) molecule influenced the efficacy of formalin-inactivated influenza a (h3n1) vaccine candidates derived from high-growth reassortants between the standard donor of high-yield genes (a/pr/8/34 [h1n1]) and host cell variants generated from the same clinical isolate (a/memphis/7/90 [h3n2]) by passage in embryonated chicken eggs. two clones of the isolate generated by growth in eggs differed from the parent virus (re ... | 1995 | 7609057 |
| immunodominance with progenitor b cell diversity in the neutralizing antibody repertoire to influenza infection. | we report striking immunodominance in the neutralizing antibody responses of major histocompatibility complex congenic mice to natural infection with influenza virus (h3n2 subtype), as deduced by sequencing the hemagglutinin (ha) genes of monoclonal antibody (mab)-selected mutant viruses. a majority of mab, established from individual balb/c (h-2d) mice, select mutant viruses containing the same single amino acid substitution in the membrane distal ecto-domain, ha1 198 a-->e, whereas changes at ... | 1995 | 7621857 |
| prevention of influenza by the intranasal administration of cold-recombinant, live-attenuated influenza virus vaccine: importance of interferon-gamma production and local iga response. | to clarify which immunological factors were more effective in preventing influenza virus infection, we measured immunological parameters induced by vaccination and infection in vivo and in vitro. healthy adult subjects (n = 128) were divided into vaccinated (n = 85) and untreated (n = 43) groups. eighty-five were vaccinated intranasally with a trivalent cold-adapted recombinant influenza virus vaccine containing type a (h1n1 and h3n2) and b viruses. subjects were mostly seropositive before vacci ... | 1995 | 7625114 |
| pulmonary immune response of young and aged mice after influenza challenge. | after influenza challenge, aged mice have prolonged viral shedding that correlates with lower splenic cytotoxic t lymphocyte (ctl) activity. to evaluate the age-related pulmonary cell-mediated immune response to influenza, pulmonary lymphocytes were obtained from young and aged mice at various days after respiratory tract infection with nonlethal influenza a/pc/1/73 (h3n2) virus. in young mice, pulmonary ctl activity peaked at 48% +/- 2% on day 7 after infection. pulmonary ctl activity peaked 1 ... | 1995 | 7636390 |
| update: influenza activity--worldwide, 1995. | from october 1994 through august 1995, influenza activity occurred at low to moderate levels in most parts of the world. influenza activity usually was associated with the cocirculation of influenza types a and b viruses. overall, influenza a(h3n2) was the predominant influenza a subtype, but isolation of influenza a(h1n1) viruses increased during this period and was the most frequently isolated influenza virus in australia from march through august. this report summarizes influenza activity wor ... | 1995 | 7643851 |
| egg fluids and cells of the chorioallantoic membrane of embryonated chicken eggs can select different variants of influenza a (h3n2) viruses. | growth of influenza viruses in embryonated eggs frequently results in the selection of virus variants with amino acid changes near the receptor-binding pocket of the hemagglutinin molecule, yet the mechanism by which this third form of influenza variation occurs (the other two being antigenic drift and shift) has not been clearly defined. because egg-mediated variation might affect influenza vaccine and surveillance programs, we have initiated studies to determine the site(s) of variant virus se ... | 1995 | 7645225 |
| the immunogenicity of reassortants of the cold-adapted influenza a master strain a/ann arbor/6/60 is determined by both the genes for cold-adaptation and the haemagglutinin gene. | two surface antigen segregants were prepared by co-infection of chicken embryo kidney cell cultures with reassortants of the cold-adapted influenza a master strain a/ann arbor/6/60-ca (h2n2) possessing the surface antigens of a/queensland/6/72 (h3n2) and a/hong kong/123/77 (h1n1) and other genes that were common to the master strain. the segregants were shown by serological tests to possess h3n1 and h1n2 surface antigens but it was not possible to determine the presence of h1 or n1 genes by sing ... | 1995 | 7646346 |
| influenza vaccination in older patients. immunogenicity, epidemiology and available agents. | excess hospitalisation and deaths attributable to influenza virus infections often occur during epidemics and even in interepidemic periods. influenza vaccines in current use are inactivated preparations that contain 15 micrograms each of the most recently circulating influenza a (h3n2 and h1n1) and b viruses. at present, 3 types of inactivated influenza virus vaccines are available: (a) whole virus vaccines; (b) split virus vaccines; and (c) subunit vaccines. all 3 types are similarly immunogen ... | 1995 | 7647426 |
| epidemiology of influenza a virus infection in patients with acute or chronic leukemia. | influenza infection is a significant cause of morbidity and mortality in immunocompromised hosts, but its importance in adult cancer patients is largely undescribed. we therefore conducted a prospective study of the incidence and clinical features of influenza infection in patients with acute or chronic leukemia. the cohort, which consisted of all adult leukemia patients undergoing remission-induction chemotherapy during the 1991-1992 influenza epidemic, was followed prospectively for developmen ... | 1995 | 7655781 |
| communitywide laboratory-based influenza surveillance focused on older persons, 1989-1992. | we collected surveillance data as part of the medicare influenza vaccine demonstration to describe communitywide epidemiology of influenza, focusing on the elderly. laboratory-based surveillance was established in medical practices, hospitals, and nursing homes in a two-county demonstration in upstate new york. time course and intensity of epidemic influenza were compared between counties, between influenza a and b epidemics, and among several levels of surveillance involving elderly persons as ... | 1995 | 7662393 |
| characterization of the virions of mopyridone-sensitive wild strain and mopyridone-resistant mutant of influenza virus a(h3n2) | some differences were established between mopyridone-sensitive (mcu-s) wild strain and mopyridone-resistant (mcu-r) mutant progenies of influenza virus a/hong kong/1/68 (h3n2). the virions of mcu-r mutant had a lower buoyant density in linear sucrose gradient as compared to those of mcu-s strain, and an increased ability of aggregation as well. ha content (hau/micrograms protein) in the purified virions of mcu-r mutant was twice lower as compared to mcu-s strain. the surface glycoproteins of mcu ... | 1995 | 7676940 |
| alpha 2-macroglobulin is the major neutralizing inhibitor of influenza a virus in pig serum. | horse, pig, and rabbit sera contain distinct glycoprotein inhibitors of influenza a viruses that inhibit hemagglutinating activity and neutralize viral infectivity. although alpha 2-macroglobulin has been identified as the inhibitor in horse serum, the inhibitors in pig and rabbit sera have not been identified. as an initial step in elucidating the structural differences among inhibitor molecules, we sought to isolate the inhibitor in pig serum. the purified inhibitor decreased the hemagglutinat ... | 1993 | 7681613 |
| prominent usage of v beta 8.3 t cells in the h-2db-restricted response to an influenza a virus nucleoprotein epitope. | the spectrum of tcr usage has been analyzed for virus-specific cd8+ t cells isolated from the regional mediastinal lymph modes and from the lung by bronchoalveolar lavage (bal) of c57bl/6 (b6) mice with influenza pneumonia. lymphocytes were recovered during the acute phase of the primary response in mice infected with an h3n2 (a/hkx31) virus, or in immune animals that were secondarily challenged with an h1n1 virus (a/pr8). cells taken directly from the bal of infected mice exhibited an increase ... | 1993 | 7689611 |
| a comparative assessment of tlc overlay technique and microwell adsorption assay in the examination of influenza a and sendai virus specificities towards oligosaccharides and sialic acid linkages of gangliosides. | influenza a and sendai viruses bind to neolacto-series gangliosides isolated from human granulocytes. differences in receptor specificity of influenza viruses a/pr/8/34 (h1n1), a/x-31 (h3n2), and parainfluenza sendai virus (hnf1, z-strain) were determined by two direct solid phase binding assays: the overlay technique, which combines high-resolution in the separation of gangliosides on thin-layer chromatograms with direct binding; and the microwell adsorption assay as a convenient binding assay ... | 1994 | 7696851 |
| type- and subtype-specific detection of influenza viruses in clinical specimens by rapid culture assay. | a rapid culture assay which allows for the simultaneous typing and subtyping of currently circulating influenza a(h1n1), a(h3n2), and b viruses in clinical specimens was developed. pools of monoclonal antibodies (mabs) against influenza a and b viruses and mabs ha1-71 and ha2-76, obtained by immunizing mice with the denatured hemagglutinin subfragments ha1 and ha2 of influenza virus a/victoria/3/75, were used for immunoperoxidase staining of antigens in infected mdck cells. mab ha1-71 reacted ex ... | 1995 | 7714186 |
| time to peak serum antibody response to influenza vaccine. | the time to the appearance of a peak serum antibody response to influenza virus vaccine is not clearly defined. we compared the most commonly used time intervals described in the literature--4 and 6 weeks after vaccination. we studied 118 elderly patients from three different geographic sites. the 1992 to 1993 trivalent inactivated influenza virus vaccine containing influenza virus a/beijing/353/89 (h3n2), influenza virus a/texas/36/91 (h1n1), and influenza virus b/panama/45/90 was used. no stat ... | 1995 | 7719904 |
| humoral response to influenza hemagglutinin: oligoclonal spectrotype and failure of thymopentin as immunoadjuvant. | influenza remains a serious cause of illness and death among certain populations. influenza vaccines in use at present are of limited effectiveness due to the high variability of the virus, and trials all over the world are in progress to enhance their immunogenicity. conflicting results, in fact, have been reported about the immune response to influenza vaccination in diverse populations. in this paper we analyzed the antibody response to the hemagglutinin (ha) of the h3n2 a/shangai 16/89 strai ... | 1995 | 7737532 |
| antiviral activity of plant flavonoid, 5,7,4'-trihydroxy-8-methoxyflavone, from the roots of scutellaria baicalensis against influenza a (h3n2) and b viruses. | we investigated effects of isoscutellarein-8-methylether (5,7,4'-trihydroxy-8-methoxyflavone, f36) from the roots of scutellaria baicalensis on the single-cycle replication of mouse-adapted influenza viruses a/guizhou/54/89 (h3n2 subtype) and b/ibaraki/2/85 in madin-darby canine kidney (mdck) cells. the agent suppressed replication of these viruses from 6 to 12 h after incubation in a dose-dependent manner by 50% at 20 microm and 90% at 40 microm, respectively. f36 (50 microm) reduced the releas ... | 1995 | 7742801 |
| the substantia nigra is a major target for neurovirulent influenza a virus. | clinical and immunohistochemical studies were done for 3-39 d on mice after intracerebral inoculation with the neurovirulent a/wsn/33 (h1n1; wsn) strain of influenza a virus, the nonneurovirulent a/aichi/2/68 (h3n2; aichi) strain, and two reassortant viruses between them. the virus strains with the wsn gene segment coding for neuraminidase induced meningoencephalitis in mice. the mice inoculated with the r96 strain, which has only the neuraminidase gene from the wsn strain, had mild symptoms and ... | 1995 | 7760004 |
| influenza a virus vaccines containing purified recombinant h3 hemagglutinin are well tolerated and induce protective immune responses in healthy adults. | this study evaluated the safety, immunogenicity, and protective efficacy of vaccines containing purified recombinant uncleaved hemagglutinin (rha0) from influenza a/beijing/32/92 (h3n2) virus. in a randomized, double-blinded trial, 127 adult volunteers were immunized with 15 micrograms of rha0, 15 micrograms of rha0 plus alum, 90 micrograms of rha0, licensed subvirion vaccine, or saline placebo. the rha0 vaccines caused fewer local adverse reactions than did the commercial subvirion preparation. ... | 1995 | 7769297 |
| [epidemiological observations on the evolution of influenza in the city of iaşi in the epidemic season of 1993-1994]. | the epidemiological, clinical and laboratory data of influenza and other respiratory diseases recorded during the epidemic season 1993-1994, as they resulted from the comparative analysis of the cases reported weekly and those recorded through the "sentinel" collectivities method, are presented. the findings at admissions to the infectious diseases hospital, military hospital, diagnosis and treatment centre for pupils and students and the solicitation for medical care at the emergency ambulance ... | 1994 | 7772893 |
| serological studies of influenza viruses in pigs in great britain 1991-2. | samples from a sow serum bank representative of the pig population of great britain collected during 1991-2, were examined for antibodies to influenza a, b and c viruses, using viruses which had been isolated from a variety of hosts. for influenza a viruses there was evidence of the continued circulation of classical swine h1n1 virus (26%) seroprevalence), and human h3n2 viruses (39%) which are antigenically most closely-related to a/port chalmers/1/73 virus. in addition antibodies were detected ... | 1995 | 7781739 |
| an outbreak of influenza a/h3n2 in a zambian school dormitory. | there was an outbreak of "a mysterious disease" at a zambian school dormitory in september, 1993. investigation with questionnaire and collection of throat swab specimens for virus isolation were carried out on 46 patients to identify the causative agent. in this outbreak, most of the patients showed similar symptoms such as fever, headache, sore throat, cough, etc. the disease had spread to all dormitories within a couple of days after the onset of the first cases. from these patients, 13 influ ... | 1995 | 7796773 |
| replication of influenza a viruses in a green monkey kidney continuous cell line (vero). | a vero cell line was investigated as a suitable host system for primary isolation and cultivation of influenza a viruses. the efficiency of primary isolation for currently circulating (h3n2) strains was similar in vero and mdck cells. of 72 egg-adapted strains investigated, 90.3% were detectable hy hemagglutinin (ha) titration in vero cells after the first passage and 51.4% after the second. the amino acid sequences of the ha1 region of influenza a viruses isolated and passaged in vero cells wer ... | 1995 | 7797924 |
| comparison of trivalent cold-adapted recombinant (cr) influenza virus vaccine with monovalent cr vaccines in healthy unselected adults. | a trivalent cold-adapted recombinant (cr) influenza virus vaccine containing types a and b viruses was compared with monovalent vaccines of each virus in a double-blind, placebo-controlled trial. adults with a wide range of preexisting antibody titers received one 0.5-ml dose intranasally of trivalent vaccine; monovalent a/h1n1, a/h3n2, or b vaccine; or placebo. all vaccines were well tolerated. serum antibody response frequencies and postvaccination geometric mean antibody titers were similar f ... | 1995 | 7797925 |
| [influenza and other acute respiratory infections. republic of cuba, 1989]. | information is provided on the epidemiological situation of influenza and other acute respiratory tract diseases in cuba during 1989. general mortality rate was 25.4 per 105 inhabitants. global morbidity rate was 373.9 per 1,000 inhabitants. the highest morbidity rate reported corresponded to children 5-14 years old and under 1 year of age. serologically, the viral agent proportionally most identified was influenza virus type a (h3n2). | 1993 | 7800896 |
| 1993-1994 influenza season: canadian laboratory diagnoses, strain characterization and post-season serosurvey (ontario). | in canada as a whole, influenza a/beijing/32/92-like virus was the dominant infecting strain in the 1993-1994 season with reported laboratory diagnoses peaking in january 1994. vaccination is again urged for all persons in high-risk groups. antibody induced by vaccination does not persist well from season to season and the emerging a/shangdong/9/93 (h3n2)-like variant is related to a/beijing/32/92(h3n2) but is inhibited less by antibodies to that strain. conditions are also consistent with possi ... | 1994 | 7812234 |
| high doses of purified influenza a virus hemagglutinin significantly augment serum and nasal secretion antibody responses in healthy young adults. | the reactogenicity and immunogenicity of purified influenza virus hemagglutinin (ha) vaccines administered intramuscularly were evaluated in two placebo-controlled clinical trials. a total of 139 healthy young adults were randomized to receive increasing doses of monovalent influenza a/taiwan/1/86 (h1n1) virus ha (range, 0 to 405 micrograms per dose [study 1]). an additional 139 subjects were given increasing doses of a trivalent ha vaccine containing equal amounts of a/h1n1 virus, a/shanghai/16 ... | 1994 | 7814484 |
| characteristics of cytotoxic t lymphocytes directed to influenza virus haemagglutinin elicited by immunization with muramyldipeptide-influenza liposome vaccine. | we examined the characterization of the antiviral t lymphocytes elicited by immunization with a novel liposome vaccine (mdp-virosome) constructed with synthetic muramyldipeptide; [6-0-(2-tetradecylhexadecanoyl)-n-acetylmuramyl-l-alanyl-d-isoglutamine] , cholesterol, influenza virus haemagglutinin and neuraminidase. the haemagglutinin glycoprotein first appeared to induce a significant subtype-specific cytotoxic activity through its arrangement on the inner and outer surfaces of the mdp-virosome. ... | 1995 | 7824883 |
| antigenic and genetic characterization of current influenza strains. | annually the influenza centre receives more than 1000 virus isolates from around the world to monitor the changing pattern of viruses causing influenza throughout the year. these are characterized antigenically using both polyclonal and monoclonal antibodies and selected viruses are subjected to closer scrutiny by nucleotide sequence analyses of their ha genes. this information is used in making the annual recommendation of vaccine composition. as in the last 15 years, influenza a viruses of bot ... | 1994 | 7843357 |
| interactions of surfactant protein a with influenza a viruses: binding and neutralization. | the interaction of pulmonary surfactant protein a (sp-a) with influenza a h1n1 and h3n2 viruses was investigated. sp-a is a sialated c type lectin with affinity for mannose residues. flow cytometry showed that binding of fluorescein isothiocyanate (fitc)-labeled sp-a to h3n2 virus-infected cells was specific and time- and concentration-dependent. oligosaccharides did not affect the binding of fitc-sp-a to the infected cells. preincubation of h1n1 and h3n2 with sp-a resulted in a dose-dependent r ... | 1995 | 7844369 |
| anti-influenza virus activity of the neuraminidase inhibitor 4-guanidino-neu5ac2en in cell culture and in human respiratory epithelium. | the anti-influenza activity of the neuraminidase inhibitor 4-guanidino-neu5ac2en (4-g-nac) was determined in madin-darby canine kidney (mdck) cells by yield reduction and elisa and in explants of human respiratory epithelium by yield reduction. in mdck cells, 50% inhibitory concentrations (ec50) averaged 0.5 microgram/ml for influenza a/virginia/88(h3n2) and 0.04 microgram/ml for a/texas/36/91(h1n1) by elisa, and < 0.01 microgram/ml for influenza a/virginia by yield reduction. in human adenoid e ... | 1994 | 7847874 |
| probing the structure of influenza b hemagglutinin using site-directed mutagenesis. | the crystal structure of the hemagglutinin (ha) of influenza virus a/aichi/68 (h3n2) from the x-31 reassortant virus was reported in 1981, but as yet there are no x-ray diffraction structures for hemagglutinins of other types or even subtypes of influenza virus. we have used site-directed mutagenesis to probe the structure of the hemagglutinin of influenza b/hong kong/8/73. we investigated a region in the globular head domain that is helical in the influenza a ha structure, targeting sidechains ... | 1995 | 7856092 |
| mixed populations in influenza virus vaccine strains. | human influenza viruses used for vaccine production have previously been adapted to grow in eggs. during egg adaptation, variants are selected and we have observed that more than one variant may derive in a single egg resulting in a mixed population. we have now investigated the extent of heterogeneity, due to host cell selection, of virus strains used for the manufacture of influenza vaccine for the 1991/1992 and 1992/1993 seasons. the a(h1n1) vaccine virus was homogeneous with respect to subst ... | 1994 | 7856297 |
| influenza a subtype cross-protection after immunization of outbred mice with a purified chimeric ns1/ha2 influenza virus protein. | influenza a/pr/8/34-derived chimeric (d) protein (sk&f 106160) composed of the first 81 amino acids (aa) of ns1 fused to the conserved 157 c-terminal aa of ha2 (ns1 1-81-ha2 65-222) was previously shown to induce h-2d-restricted protective cytotoxic t-lymphocyte (ctl) immunity in inbred mice. however, d protein, like other small peptides, exhibited haplotype dependence and was not immunogenic in h-2b and h-2k mice. a potential use of this antigen in humans and the role of t cells in any protecti ... | 1994 | 7856302 |
| amantadine-resistant influenza a in nursing homes. identification of a resistant virus prior to drug use. | amantadine hydrochloride and rimantadine hydrochloride have been used for treatment and prevention of influenza a infection in nursing home residents. outbreaks of influenza a (h3n2) virus infection occurred in three nursing homes in yakima county, washington, during january 1992. amantadine was used for case treatment and prophylaxis in all three nursing homes. | 1995 | 7864709 |
| antigenic characterization of an h3n2 swine influenza virus isolated from pigs with proliferative and necrotizing pneumonia in quebec. | a new strain of swine influenza a virus, designated a/swine/saint-hyacinthe/150/90 has been isolated from pigs with severe proliferative and necrotizing pneumonia in quebec. the antigenic characterization of the hemagglutinin was performed by hemagglutination inhibition test, immunoblot and indirect immunoprecipitation using polyclonal antisera. only the last test was able to detect an antigenic relationship between the hemagglutinin of this isolate and an h3 subtype influenza virus. the immunop ... | 1994 | 7889461 |
| genetic analysis of porcine h3n2 viruses originating in southern china. | from immunological and phylogenetic analyses of h3 influenza viruses isolated from pigs and ducks in the people's republic of china (china), hong kong, taiwan and japan, between 1968 and 1982, we arrived at the following conclusions. the h3 haemagglutinin and n2 neuraminidase genes from swine isolates can be segregated into four mammalian lineages, including: (i) the earliest human strains; (ii) early swine strains including hong kong isolates from 1976-1977; (iii) an intermediate strain between ... | 1995 | 7897351 |
| recent h3n2 swine influenza virus with haemagglutinin and nucleoprotein genes similar to 1975 human strains. | of the four pandemic strains of human influenza a virus observed this century, the 1977 virus strain was very similar in all genes to a 1950 isolate. since mammalian influenza a viruses change annually by genetic drift, this reappearance could only be attributed at that time to conservation of the virus in a frozen state. we report here the isolation of swine influenza a viruses with haemagglutinin and nucleoprotein genes which are virtually identical to those of the human virus that circulated ... | 1995 | 7897358 |
| prevalence of infections with enzootic respiratory and enteric viruses in feeder pigs entering fattening herds. | the prevalence of infections with h1n1- and h3n2-influenza viruses, porcine respiratory coronavirus (prcv), transmissible gastroenteritis virus (tgev) and porcine epidemic diarrhoea virus (pedv) in feeder pigs shortly after their entry into fattening units was examined. ten groups of pigs with acute respiratory disease during the months september to october 1991 and seven groups of pigs with acute diarrhoea during the months february to march 1992 were investigated. on arrival in the fattening h ... | 1994 | 7900243 |
| medical practice-based influenza surveillance: viral prevalence and assessment of morbidity. | regular surveillance of influenza virus activity and associated illness is necessary to monitor changes in circulating strains. as part of a demonstration project, medical practices in a seven-county area in southern lower michigan were recruited as sentinel surveillance sites. the practices were asked to collect specimens for virus isolation and/or data on age-specific frequency of respiratory illnesses that met a case definition. data were used to establish periods of influenza virus activity ... | 1995 | 7900716 |
| induction of cd8+ cytotoxic t cells by immunization with killed influenza virus and effect of cholera toxin b subunit. | the mhc class i cytotoxic t-lymphocyte (ctl) response in mice given formalin-inactivated influenza whole-virus vaccine (wvv) with or without cholera toxin b subunit (ctb) was studied. intraperitoneal injection of balb/c (h-2d) mice with high doses of a/taiwan/1/86 (h1n1) wvv stimulated influenza a virus-specific ctl response in a dose-dependent manner. a dose of 4.4 or 44 micrograms induced ctl response equal to or greater than live influenza virus infection. coadministration of vaccine with 5 o ... | 1993 | 7903015 |
| combined antiinfluenza activity of a plant preparation shs-174 and amantadine derivatives. | the results of the study on the combined antiviral activity of the shs-174 preparation (a lyophylized infusion from three higher plants) and three amantadine derivatives (rimantadine, amantadine glucuronide and its derivative) are presented. the antiviral effect of the drugs on the reproduction of influenza virus strains a/h1n1 and a/h3n2 in vitro was studied. the combined antiviral effect was evaluated on the basis of viral yields and in many cases a synergism was found. the most synergistic ef ... | 1993 | 7905240 |
| immunogenicity of new virosome influenza vaccine in elderly people. | the safety and immunogenicity of a new virosome influenza vaccine was compared to commercial whole-virus vaccine and subunit vaccine in elderly people. the virosome vaccine was made by extracting the haemagglutinin from influenza virus and incorporating it into the membrane of liposomes composed of phosphatidylcholine (pc) and phosphatidylethanolamine (pe). 126 residents of a nursing home, aged 63-102, were randomised to receive one of the vaccines. all three were well tolerated and caused a sig ... | 1994 | 7912766 |
| role of surface glycoproteins in influenza virus pyrogenicity. | eleven h3n2, seven h1n1 and three h3n1 influenza virus reassortants of the pyrogenic a/puerto rico/8/34-a/england/939/69 clone 7a (h3n2) (a/7a) and poorly pyrogenic a/fiji/15899/83 (h1n1) (a/fiji) parents were analysed genetically for the parental origin of their genes and for their pyrogenicity in ferrets. all h3n2 reassortants were pyrogenic and produced significantly more fever than a/fiji but differences in pyrogenicity between them could not be correlated with either single or constellation ... | 1994 | 7931175 |
| polyacrylamides bearing pendant alpha-sialoside groups strongly inhibit agglutination of erythrocytes by influenza a virus: multivalency and steric stabilization of particulate biological systems. | an alpha-sialoside linked to acrylamide by a short connector (5-acetamido-2-o-(n-acryloyl-8-amino-5-oxaoctyl)-2,6-anhydro-3,5-d ideoxy-d-galacto-alpha-nonulopyranosonoic acid, 1) was prepared. compound 1 formed high molecular weight copolymers with acrylamide, derivatives of acrylamide, and/or vinylpyrrolidone upon photochemically-initiated free radical polymerization. those copolymers for which the substituents on the acrylamido nitrogen were small inhibited the agglutination of chicken erythro ... | 1994 | 7932570 |
| efficacy of inactivated vaccine in preventing antigenically drifted influenza type a and well-matched type b. | to evaluate the efficacy of currently used inactivated influenza vaccine during a severe epidemic caused by antigenically drifted influenza type a(h3n2) and well-matched type b viruses during the 1992-1993 season. | 1994 | 7933325 |
| a potential peptide vaccine against two different strains of influenza virus isolated at intervals of about 10 years. | we have developed a strategy for making synthetic peptide vaccines, in which a peptide, ha127-133, derived from the hemagglutinin (ha) of a/aichi/2/68(h3n2) influenza virus (aichi/68) is introduced into the ab binding component consisting of 43-46 and 54-58 residues of a pigeon cytochrome c analogue peptide, 46f50v54a. indeed, this hybrid peptide, 46f/ha127-133/54a, induced impressive t-cell responses and antibody production neutralizing infectivity of aichi/68 in vitro. in a subsequent study we ... | 1994 | 7937811 |
| [factors associated with the occurrence of influenza a virus infections in fattening swine]. | in august of 1989 sera from 2115 finishing pigs out of 214 herds in the north of schleswig- holstein (germany) were tested for antibodies against three strains of influenza a viruses by using the haemagglutination inhibition test. seroprevalences of a/swine/nederland/25/80 (h1n1), a/philippines/2/82 (h3n2), and a/port chalmers/1/73 (h3n2) on herd level were 23.4%, 20.6% and 5.1% respectively. the mean within herd prevalences were 9.6%, 14.7% and 0.6%, respectively. antibodies against h1n1 and h3 ... | 1994 | 7945181 |
| immunodominance correlates with t-cell receptor (alpha beta) gene usage in the class ii-restricted response to influenza haemagglutinin. | class ii-restricted t-cell clones elicited by natural infection with influenza a virus (h3n2 subtype) exhibit extensive diversity in their recognition specificity for the envelope glycoprotein, haemagglutinin, and focus on hypervariable regions of the ha1 subunit that feature in antigenic drift. however, t-cell clones established from the same individual focus on a single antigenic site with differing fine specificity for mutant viruses. we wished to determine whether such diversity of the haplo ... | 1994 | 7959866 |
| an outbreak of influenza a (h3n2) in delhi, 1993. | an outbreak of influenza a, subtype h3n2 occurred in delhi during july-august, 1993. both urban and rural areas were affected. attack rates in children and adults were found to be similar; the mean age of patients from whom the virus was isolated was found to be 21 years. the disease was of acute onset, mild in nature and about one week in duration. main symptoms included fever, chills, cough, sore throat, bodyaches, backache and headache. complications were absent. about 82 per cent of the affe ... | 1994 | 7963377 |
| class i major histocompatibility complex-restricted cytotoxic t lymphocytes are not necessary for heterotypic immunity to influenza. | mice transgenic for beta 2-microglobulin deletion (beta 2m-/-) were immunized intranasally with either a recombinant vaccinia virus that expressed both nucleoprotein and interleukin-2 or by infection with h3n2 influenza virus; 3-4 weeks later they were challenged with h1n1 influenza virus. the immunized beta 2m-/- mice had increased survival and enhanced clearance of virus relative to nonimmune controls. this protection correlated with the development of class ii major histocompatibility complex ... | 1994 | 7963713 |
| evaluation of the genetic stability of the temperature-sensitive pb2 gene mutation of the influenza a/ann arbor/6/60 cold-adapted vaccine virus. | a single-gene reassortant bearing the pb2 gene of the a/ann arbor/6/60 cold-adapted virus in the background of the a/korea/82 (h3n2) wild-type virus is a temperature-sensitive (ts) virus with an in vitro shutoff temperature of 38 degrees c. a single mutation at amino acid (aa) at 265 (asp-ser) of the pb2 protein is responsible for the ts phenotype. this ts single-gene pb2 reassortant virus was serially passaged at elevated temperatures in madin-darby canine kidney cells to generate ts+ phenotypi ... | 1994 | 7966557 |
| a new influenza virus a/h3n2 variant of taiwan origin. | a clinical isolate of influenza virus a/h3n2 from a one-year-old boy with pharyngitis was examined by using rna-polymerase chain reaction (pcr) for amplification of viral cdna and subsequent dna sequencing with asymmetric pcr. since antigenic drift has been found in recent a/h3n2 isolates, this strain was compared with a/shanghai/24/90 and other a/h3n2 strains, collected at the centers for disease control and prevention (cdc) in atlanta, ga, usa. it was found that the steady changes of amino aci ... | 1993 | 7988282 |
| [secondary structure of the m2 protein of influenza type a virus and its role in forming resistance to rimantadine and deitiforin]. | studies of the molecular aspects of resistance of influenza virus a to drugs (rimantadine, deytiforine, amantadine) allow a purposeful design of new compounds with a broad spectrum of antiviral activity and evoking no resistance. in this work the nucleotide sequence of rimantadine- and deytiforine-resistant influenza a strain leningrad/156/83 (h3n2) was compared with that of a/victoria/35/72. the influence of aminoacid substitutions in the m2 protein on its secondary structure in the membrane an ... | 1994 | 7990823 |
| nonimmunoselected intrastrain genetic variation detected in pairs of high-yielding influenza a (h3n2) vaccine and parental viruses. | seven influenza a (h3n2) high-yielding vaccine candidate strains were examined. antigenic analysis revealed that 5 of the strains could be distinguished antigenically from their corresponding wild type parent viruses. comparative sequence data for the ha1 domains of the ha (hemagglutinin) genes for these 5 high-yielding viruses and the corresponding wild type parents demonstrated one to three amino acid substitutions within each virus pair, with at least one amino acid change being located in a ... | 1994 | 7995982 |
| [the use of monoclonal antibodies for detecting the influenza virus]. | the possibilities of using influenza a (leningrad) 385/80 (h3n2) virus matrix protein-specific fitc-labeled d8 monoclonal antibodies in immunofluorescence assays were investigated. the virus antigen accumulation was detected in chorioallantoic cells of chick embryos. exhibiting the type-specific properties, the fluorescent antibodies stain the perinuclear space, cytoplasmic membrane, and granular structures in the cytoplasm of infected cells. the haemagglutination test tires in the corresponding ... | 1994 | 7998401 |
| hemagglutinating and sialidase activities of subpopulations of influenza a viruses. | the present study was conducted to investigate the characteristics of two samples of influenza a/england/42/72 (h3n2) virus, one of them selected by an adsorption-elution technique, to determine the possible existence of virus variants or subpopulations. based on specificity of virulence-related cell receptor-binding and sialidase activities, this selection technique using human o group erythrocytes revealed the presence of variants within a standard virus sample with diversity for their hemaggl ... | 1994 | 8000335 |
| diagnosis of equine influenza by the polymerase chain reaction. | influenza a is a common respiratory infection of horses, and rapid diagnosis is important for its detection and control. sensitive detection of influenza currently requires viral culture and is not always feasible. the polymerase chain reaction (pcr) was used to detect dna produced by reverse transcription of equine influenza in stored nasal secretions, vaccines, and allantoic fluids. primers directed at a target of 212 bp on conserved segment 7 (matrix gene) of human influenza a/bangkok/1/79(h3 ... | 1994 | 8011780 |
| neutralization enzyme immunoassay for influenza virus. | a neutralization enzyme immunoassay (n-eia) was developed for the detection of antibody titer rises in sera of patients infected with influenza a (h3n2) virus. in this n-eia, a selected strain of influenza a (h3n2) virus was added to monolayers of llc-mk2 cells in microtiter plates. after 24 h, the replicated virus could be demonstrated with a virus-specific enzyme-labeled monoclonal antibody. preincubation of the influenza virus with convalescent-phase sera of patients infected with influenza a ... | 1994 | 8027355 |
| evidence for interspecies transmission and reassortment of influenza a viruses in pigs in southern china. | the asian/57, hong kong/68, and russian/77 pandemics of this century appeared or reappeared in china. interspecies transmission and genetic reassortment of influenza viruses have been implicated in the origin of these human pandemic influenza viruses. pigs have been suspected to be the "mixing vessel" where reassortment occurs. to investigate this possibility, 104 porcine influenza viruses collected at random from southern china from 1976 to 1982, including 32 h3n2 isolates and 72 h1n1 isolates, ... | 1994 | 8030245 |
| influenza virus host resistance models in mice and rats: utilization for immune function assessment and immunotoxicology. | each year influenza viruses are responsible for epidemic respiratory diseases with excess morbidity and mortality. the severity of influenza diseases ranges from mild upper respiratory tract infections to severe lower respiratory tract infections involving pneumonia, bronchiolitis and coincidental bacterial super-infections. the immune response to influenza viruses can be schematically divided into a cascade of non-specific and specific functions. these functions are involved at different well d ... | 1994 | 8059441 |