Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| [the anomalous isoelectric properties of influenza virus matrix protein m1]. | the isoelectric point (pi) values of matrix protein m1 of influenza a, b, and c viruses, calculated theoretically on the basis of its primary structure, were found to be about 10.0. however, experimental pi determination by electrofocusing in ampholyte-containing polyacrylamide gel showed it to be 5.0 for m1 protein isolated from a/wsn/33 (h1n1) and a/aichi/2/68 (h3n2) viruses by mild deproteinization with nonionic detergents. this marked discrepancy between experimental and theoretical pi value ... | 1991 | 1891873 |
| characterization of the attenuating m and np gene segments of the avian influenza a/mallard/78 virus during in vitro production of avian-human reassortant vaccine viruses and after replication in humans and primates. | a unique requirement for live attenuated reassortant influenza vaccines is the need to generate new reassortant vaccine viruses with the appearance of each new antigenic variant. thus, the attenuation phenotype conferred by the attenuated donor influenza virus must remain genetically stable during the generation of each new reassortant vaccine virus. in this study we used nucleotide sequence analysis to evaluate the genetic stability of the attenuating m and np genes of the avian influenza a/mal ... | 1991 | 1897305 |
| superiority of live attenuated compared with inactivated influenza a virus vaccines in older, chronically ill adults. | forty-eight older adults with chronic diseases were vaccinated intranasally with live attenuated influenza a/korea/1/82 (h3n2), cr59 virus. forty-two (88 percent) cr59 virus recipients became infected with vaccine virus without adverse effects or change in mean pulmonary function even among the 29 infected recipients with moderate to severe chronic obstructive pulmonary disease. among control groups who received either monovalent or trivalent inactivated influenza virus vaccines intramuscularly, ... | 1991 | 1914615 |
| clearance of influenza virus respiratory infection in mice lacking class i major histocompatibility complex-restricted cd8+ t cells. | transgenic mice homozygous for a beta 2-microglobulin (beta 2-m) gene disruption and normal mice that had been treated with a cd8-specific mab were infected intranasally with an h3n2 influenza a virus. both groups of cd8t cell-deficient mice eliminated the virus from the infected respiratory tract. potent ctl activity was detected in lung lavage populations taken from mice with intact cd8+ t cell function, with minimal levels of cytotoxicity being found for inflammatory cells obtained from the a ... | 1991 | 1919440 |
| influenza a(h1n1): a widening spectrum? | to study the incidence of h1n1 influenza from 1977 to 1988 in unvaccinated volunteers and the effects of continuing minor antigenic change (antigenic drift) in the virus. | 1991 | 1921782 |
| involvement of the influenza a virus pb2 protein in the regulation of viral gene expression. | to determine the function(s) of the pb2 protein of influenza a virus, six temperature-sensitive (ts) mutants of a/udorn/72 (h3n2) virus, each carrying a ts mutation in the pb2 gene, were analysed for virus rna and protein synthesis. one of the mutants, icrc27, exhibited unique phenotypes and was characterized in detail. at the non-permissive temperature, 40 degrees c, the accumulation of mrna for each genome segment was reduced severely, leading to delayed and reduced synthesis of viral proteins ... | 1991 | 1940863 |
| the herald waves of influenza virus infections detected in sendai and yamagata cities in 1985-1990. | the community surveillance of respiratory virus infections performed during 1985-1987 in sendai and 1988-1990 in yamagata has identified a total of five herald waves of influenza virus infections: a/h3n2 virus infections in 1985 and 1989, a/h1n1 virus infections in 1986 and 1988, and type b virus infections in 1989. to investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza a/h1n1 viruses isolated during the 1986 and 1988 herald waves were comp ... | 1991 | 1943849 |
| immunogenicity of trivalent subunit and split influenza vaccines (1989-90 winter season) in volunteers of different groups of age. | trivalent split or subunit influenza vaccines [a/shangai/11/87 (h3n2), a/singapore/6/86 (h1n1) and b/yamagata/16/88] recommended for the 1989-90 winter season and licensed in italy, were administered to 149 volunteers of three different age groups (elderly, middle-aged and young). antibody production was determined in pre- and postvaccination sera by haemagglutinin inhibition test and the results were evaluated as protection and response rates. the split vaccine was more immunogenic than the sub ... | 1991 | 1950094 |
| [the evaluation of the reactogenicity and immunological activity of an inactivated 3-component influenza vaccine with an elevated hemagglutinin concentration in the inoculation dosage]. | in this work the reactogenic properties and antigenic potency of inactivated trivalent influenza vaccine, obtained by elution and centrifugation and containing up to 9-11 micrograms of hemagglutinin for influenza viruses a(h1n1) and a(h3n2) and up to 14 micrograms for influenza virus b, were studied. the reactogenicity of the preparation was found to correspond to the regulations. the immunogenic potency characteristics of individual batches of this trivaccine were higher than the immunogenicity ... | 1991 | 1950267 |
| emergence and possible transmission of amantadine-resistant viruses during nursing home outbreaks of influenza a (h3n2). | outbreaks of influenza a (h3n2, a/shanghai/11/87-like) occurred in two partially (60% and 79%) vaccinated nursing home populations in january 1988. a retrospective cohort study using chart review was designed to assess the effectiveness of influenza vaccination and amantadine prophylaxis (100 mg per day) in controlling the outbreaks and to determine the amantadine susceptibility of influenza viruses isolated from case-patients. the point estimate of vaccine efficacy in preventing influenza-like ... | 1991 | 1951297 |
| recovery of drug-resistant influenza a virus during therapeutic use of rimantadine. | the therapeutic activity of rimantadine and its relationship to the shedding of drug-resistant influenza a virus were assessed in two randomized, double-blind, placebo-controlled trials involving patients with laboratory-documented influenza a virus (h3n2 subtype) illness of 2 days' duration or less. in a family-based study, rimantadine treatment for 10 days (24 children and adults) was associated with significant decreases in the number of days to a 50% reduction in symptoms (mean difference, 2 ... | 1991 | 1952841 |
| an unusual community outbreak of influenza a. | the hong kong h3n2 subtype of influenza a virus appeared in 1968 and since then has caused epidemics of varying degrees of severity. we describe a community outbreak of influenza a h3n2 which occurred in members of a bowls club in an english rural village in late april 1989. the explosive onset, high attack rate (34/41 = 83 per cent) in those exposed, and the clinical presentation initially suggested a toxic or allergic aetiology. twenty-three persons consulted their general practitioners; befor ... | 1991 | 1958413 |
| control of influenza a outbreaks in nursing homes: amantadine as an adjunct to vaccine--washington, 1989-90. | outbreaks of influenza a virus infection can cause substantial morbidity and mortality among residents of nursing homes. surveillance for the 1991-92 influenza season indicates that the dominant circulating viruses are influenza a (1), for which amantadine hydrochloride is effective for prevention and treatment (2). this report describes the use of amantadine as an adjunct to influenza vaccine for controlling an influenza a(h3n2) outbreak that occurred in a washington nursing home during the 198 ... | 1991 | 1961174 |
| the genes associated with trans-dominance of the influenza a cold-adapted live virus vaccine. | segment 7 (m) of the cold-adapted live influenza a virus vaccine plays a primary role in the ability of this virus to interfere with the replication of wild-type influenza a viruses. this conclusion is based on several lines of evidence. single gene reassortant viruses derived by crossing influenza a/ann arbor/6/60 (h2n2) cold-adapted donor virus with an epidemic wild-type strain, a/korea/1/82 (h3n2), were tested for their ability to interfere with wild-type parental virus in the madin-darby lin ... | 1991 | 1984670 |
| a dominant idiotype in the antibody response against the influenza virus hemagglutinin. serum and in situ analyses. | py206 is an id associated with a balb/c murine mab described as being specific for the influenza a virus hemagglutinin. however, production of this id by balb/c mice immunized with influenza is low. this report shows that the py206 id is a dominant component of the anti-influenza antibody response in c57bl/6j strain mice infected intranasally with the influenza a/hong kong/168/(h3n2)[r] x-31 virus. high py206 id expression was linked to the ighb ig allotype locus. py206 id+ antibody-forming cell ... | 1991 | 1993846 |
| age distribution of patients with medically-attended illnesses caused by sequential variants of influenza a/h1n1: comparison to age-specific infection rates, 1978-1989. | since influenza a/h1n1 viruses reappeared during the 1977-1978 season, this subtype has contributed 27% of 6,609 documented influenza infections of persons with acute respiratory disease presenting to clinics serving as surveillance sites of the influenza research center in houston for the 12-year period ending june 1989. wide differences in the distribution of h1n1 viruses occurred by age group: more than 50% of h1n1 infections were detected among persons aged 10-34 years, compared with 28% for ... | 1991 | 2000847 |
| passive transfer of local immunity to influenza virus infection by iga antibody. | secretory iga is presumed to be the mediator of mucosal immunity based on many studies that show a correlation between protection and secretory iga titers; however, a causal relationship has not yet been established. classically, passive transfer of antibody has been used to demonstrate causality, but the passive transfer of local immunity with physiologically transported iga has not been previously reported. in this study mice were injected intravenously with polymeric iga (piga), monomeric iga ... | 1991 | 2005388 |
| evolutionary pathways of n2 neuraminidases of swine and human influenza a viruses: origin of the neuraminidase genes of two reassortants (h1n2) isolated from pigs. | the complete nucleotide sequences of the neuraminidase (na) genes of two reassortant (h1n2) and two h3n2 influenza a viruses isolated from pigs were determined and phylogenetic relationships between these and previously reported n2 na genes were investigated. on the basis of pairwise nucleotide sequence identity, the na genes of two reassortants, a/sw/kanagawa/2/78 and a/sw/ehime/1/80, were most closely related to those of human influenza a virus strains isolated in 1972 and the earliest availab ... | 1991 | 2005434 |
| homotypic and heterotypic protection against influenza virus infection in mice by recombinant vaccinia virus expressing the haemagglutinin or nucleoprotein of influenza virus. | recombinant vaccinia virus expressing the influenza virus haemagglutinin (ha) or nucleoprotein (np) genes from a/sw/hong kong/1/74 (h1n1) under the control of a hybrid promoter containing the p7.5 early promoter element and promoter of the gene encoding the major protein of cowpox virus a type inclusion body was constructed to investigate protective immunity against homologous and heterologous viruses in mice. these recombinant vaccinia viruses produced authentic influenza virus ha and np in inf ... | 1991 | 2005435 |
| genetic relationship between the ha genes of type a influenza viruses isolated in off-seasons and later epidemic seasons. | from january 1985 to march 1989, off-season viruses of h1n1 and h3n2 subtypes of influenza a viruses were isolated on five occasions in japan. the ha gene sequences of the influenza a(h1n1) and a(h3n2) viruses isolated in japan from 1985-9 were analysed and the phylogenetic tree for each subtype virus was constructed to determine any genetic relationship between viruses isolated in off-seasons and the epidemic viruses of the following influenza seasons. in one instance with h1n1 viruses in 1986 ... | 1991 | 2019304 |
| the a/mallard/6750/78 avian-human, but not the a/ann arbor/6/60 cold-adapted, influenza a/kawasaki/86 (h1n1) reassortant virus vaccine retains partial virulence for infants and children. | characteristics of avian-human (ah) and cold-adapted (ca) influenza a/kawasaki/9/86 (h1n1) reassortant vaccine viruses were compared in 37 seronegative adults and 122 seronegative infants and children. the 50% human infectious dose (hid50) in infants and children was 10(2.9) and 10(2.6) tcid50 for the ah and ca vaccine, respectively. the ah influenza a/kawasaki/9/86 reassortant was reactogenic: 24% of infants and children infected with greater than or equal to 100 hid50 had fever greater than or ... | 1991 | 2019751 |
| complement is activated in the upper respiratory tract during influenza virus infection. | the purpose of this pilot study was to determine whether complement is activated in the upper respiratory tract during experimental influenza virus infection in human volunteers. seven subjects were challenged with influenza a/bethesda/1/85 (h3n2), and four subjects received placebo. c3a and c5a concentrations were measured by radioimmunoassay in nasal lavage fluids before challenge and for 8 days after challenge. a significant increase (p less than 0.05) in c3a and c5a concentrations was demons ... | 1991 | 2024815 |
| influenza in senescent mice: impaired cytotoxic t-lymphocyte activity is correlated with prolonged infection. | influenza and pneumonia are leading causes of death in the elderly. cytotoxic t-lymphocyte activity is responsible for viral clearance after infection and declines with age. we hypothesized that following intranasal infection with influenza virus, aged mice would have decreased anti-influenza cytotoxic t-lymphocyte activity that would correlate with prolonged pulmonary viral shedding. to test this, young (1.5-4.0 month) and aged (22-25 month) balb/c mice were infected intranasally with influenza ... | 1991 | 2037313 |
| in elderly persons live attenuated influenza a virus vaccines do not offer an advantage over inactivated virus vaccine in inducing serum or secretory antibodies or local immunologic memory. | in a double-blind, randomized trial, 102 healthy elderly subjects were inoculated with one of four preparations: (i) intranasal bivalent live attenuated influenza vaccine containing cold-adapted a/kawasaki/86 (h1n1) and cold-adapted a/bethesda/85 (h3n2) viruses; (ii) parenteral trivalent inactivated subvirion vaccine containing a/taiwan/86 (h1n1), a/leningrad/86 (h3n2), and b/ann arbor/86 antigens; (iii) both vaccines; or (iv) placebo. to determine whether local or systemic immunization augmente ... | 1991 | 2037667 |
| measurement of igm responses to a subunit influenza a vaccine by sucrose-gradient centrifugation and membrane-filtration enzyme immunoassays. | igm responses to a deoxycholate-split influenza vaccine containing the surface antigens of the h3n2 virus a/philippines/2/82 were studied in five volunteers, three of whom were seronegative by haemagglutination inhibition (hi) tests. responses were measured by a sucrose-gradient centrifugation technique, in which igm-specific hi activity was computed as a proportion of total igm and igg-specific hi activity, and by a membrane filtration-enzyme immunoassay (mf-eia). responses could be detected in ... | 1991 | 2049172 |
| agglutination of human o erythrocytes by influenza a(h1n1) viruses freshly isolated from patients. | the hemagglutinin titers of 10 influenza a (h1n1) viruses were examined using the erythrocytes of several species. human o erythrocytes showed the highest agglutination titer to the viruses, whereas chicken erythrocytes showed a low titer. these findings were noted for at least 10 passages by serial dilutions of the viruses in madin-darby canine kidney (mdck) cells. all influenza a(h1n1) viruses, plaque-cloned directly from throat-washing specimens of patients, also agglutinated human o but not ... | 1991 | 2066386 |
| cross-protection against influenza a virus infection by passively transferred respiratory tract iga antibodies to different hemagglutinin molecules. | mice that were intranasally immunized with different influenza a virus hemagglutinins (ha), derived from pr8 (h1n1), a/yamagata (h1n1) or a/fukuoka (h3n2) virus, together with cholera toxin b subunit as an adjuvant, were examined for protection against pr8 infection; pr8 ha and a/yamagata ha immunization conferred complete protection, while a/fukuoka ha immunization failed to confer protection. in parallel with protection, pr8 ha-, a/yamagata ha-, and a/fukuoka ha-immunized mice produced a high, ... | 1991 | 1646112 |
| influenza virus rna in the lung and lymphoid tissue of immunologically intact and cd4-depleted mice. | the distribution and clearance of viral rna (vrna) and mrna has been analysed for the acute and recovery stages of the pneumonia induced by intranasal infection of c57bl/6j mice with h3n2 influenza a viruses. amplification of viral genomic material by the polymerase chain reaction showed that the influenza haemagglutinin (ha) gene was eliminated from the lungs of immunologically intact mice by day 14 post-infection, whereas in vitro depletion of the cd4+ t cells delayed clearance by at most 4 da ... | 1991 | 1677414 |
| distinct glycoprotein inhibitors of influenza a virus in different animal sera. | normal horse and guinea pig sera contain the glycoprotein inhibitor alpha 2-macroglobulin, which inhibits the infectivity and hemagglutinating activity of influenza a viruses of the h2 and h3 subtypes. in the current study, the presence of inhibitors of influenza a virus in pig and rabbit sera was investigated. variants of influenza virus type a/los angeles/2/87(h3n2) that were resistant to horse, pig, or rabbit serum were isolated. analysis of the variant viruses with anti-hemagglutinin (ha) mo ... | 1991 | 1702161 |
| conservation of epitopes recognized by monoclonal antibodies against the separated subunits of influenza hemagglutinin among type a viruses of the same and different subtypes. | monoclonal antibodies raised against the separated hemagglutinin subunits (ha1 and ha2) of influenza a/vic/3/75 (h3n2) virus were tested against a large panel of human and avian strains. the epitopes recognized by most antibodies were conserved among subtype h3 viruses, but reactivity of some antibodies with members of other subtypes was also observed. particularly, the h4 virus reacted with most antibodies directed against the ha2 subunit. these results are discussed in terms of sequence simila ... | 1991 | 1705790 |
| inhibition of influenza a virus hemagglutinin and induction of interferon by synthetic sialylated glycoconjugates. | multivalent forms of neoglycoproteins and polyacrylamides containing sialic acid were prepared and shown to be potent inhibitors of influenza a virus (h3n2) hemagglutinin with chick red blood cells. the synthetic sialylated glycoconjugates, although they were neuraminidase substrates, did not suppress viral neuraminidase and did not reduce infectivities in chick embryos. the copolyacrylamide conjugate containing a spacer group of approximately 11 a (1 a = 0.1 nm) between the polymer backbone and ... | 1991 | 1711409 |
| [the heterogeneity of an influenza virus a population due to differences at individual hemagglutinin h3 sites]. | using monoclonal antibodies to hemagglutinin and nucleoprotein of various influenza virus strains, the populations of long-passaged strain a/hong kong/1/68 and of recently isolated strain a/sparrow/ukraine/83 belonging to the h3n2 serovariant were shown to have subpopulations of virions differing in the structure of antigenic sites of hemagglutinin and in nucleoprotein domain which correlated with the degree of electrostatic interaction of virions with an ion-exchanger. the results of the study ... | 1991 | 1715627 |
| use of monoclonal anti-haemagglutinin antibodies for the "in vitro" selection of a sequential influenza virus antigenic variant. | a sequential antigenic variant of the a/texas/77 (h3n2) influenza virus was obtained in vitro using a monoclonal antibody against the haemagglutinin (ha) of the antigenic variant v18 previously selected in vitro from the parental texas virus. the sequential antigenic variant, designated dv1, the v18 antigenic variant and the parental a/texas/77 viruses were used to evaluate the frequency of anti-haemagglutinin antibodies in human sera in single radial haemolysis assays. twenty six of 100 childre ... | 1991 | 1717311 |
| [the strain-specific diagnosis of influenza by using lanthanide immunofluorescence analysis based on monoclonal antibodies to the hemagglutinin of the influenza a virus]. | nine monoclonal antibodies (mca) to hemagglutinin of influenza a/taiwan/1/86 (h1n1) virus and 5 mca to influenza a/mississippi/1/85 (h3n2) virus were generated and characterized. the mca were used for the development of diagnostic test systems on the basis of time-resolved fluoroimmunoassay. the same mca were used as primary and detecting antibodies in the test system specific for ha of the h1 serosubtype, whereas in the test system specific for influenza a serosubtype h3 virus mca of different ... | 1991 | 1724583 |
| [new sites in the hemagglutinin composition of epidemic variants of the influenza virus a (h3n2) from 1989-1990]. | immunological analysis of the antigenic structure of hemagglutinin of newly isolated variants of influenza (h3n2) virus carried out using monoclonal and monospecific antibodies to individual antigenic sites of hemagglutinin showed the 1989-1990 isolates to be markedly different in their antigenic properties from the variants isolated in previous years. sites with new antigenic properties were determined in hemagglutinin of the isolates. wide variability was found in the region of three immunodom ... | 1991 | 1725076 |
| studies on the adaptation of influenza virus replicated at low temperature. iii. biochemical studies. | five strains of influenza viruses a(h3n2) replicated at low temperature passaged in cotton rats were reisolated. the properties of these strains replicated at low temperature were compared before and after passage in susceptible animals to check the stability of some its markers. at the same time original viruses replicated at 37 degrees c--which are different in epidemiological potency--were compared. the following parameters being tested: na activity, ha titers, heat inactivation na and ha, mi ... | 1990 | 1715640 |
| [differences in the structure of the hemagglutinin gene in variants of the influenza a (h3n2) virus, differing in immunogenic activity]. | 1990 | 1706067 | |
| [comparative study of parenteral and oral immunization against influenza in a large clinical trial. 2. results of immunologic studies]. | in a multicentric trial 350 persons (19-24 years) were immunized with influenza vaccines containing the following virus antigens: a/singapore/6/86, (h1n1); a/mississippi/1/85, (h3n2); b/ann arbor/1/86. 174 received an i.m. injection of 0.5 ml "influmun" vaccine from ssw dresden/gdr. 176 persons were immunized twice within 60 days with enteric-wated capsules each containing approximately 60 micrograms hemagglutinin of all three virus strains. the volunteers were clinically observed in an interval ... | 1990 | 1706903 |
| cellular events in the lymph node and lung of mice with influenza. consequences of depleting cd4+ t cells. | the cellularity of the mediastinal lymph nodes of mice infected intranasally with a high dose of an h3n2 influenza a virus increases massively within 5 days. all classes of lymphocytes are involved. a similar, but much smaller, expansion in cell numbers occurs after exposure to a comparable dilution of normal chick allantoic fluid. in the control group, this increase in lymph node size is totally prevented by the in vivo depletion of cd4+ t cells whereas there is only a 50% reduction in the viru ... | 1990 | 1692070 |
| single amino acid residues in a synthetic peptide of influenza haemagglutinin, ha 1 177-199, distinguish i-ad- and i-ed-restricted t-cell epitopes. | a majority of iad-restricted, cd4+ t-cell clones, derived from balb/c mice infected with x31 (h3n2) influenza virus and specific for the ha 1 subunit of the viral haemagglutinin (ha), has previously been shown to recognize the synthetic peptide ha 1 177-199, corresponding to the primary amino acid sequence of a major antibody binding site. here it is demonstrated that both i-ad- and i-ed-restricted t-cell clones recognize ha 1 177-199, and that inter- and intra-allelic differences in iad-restric ... | 1990 | 1693908 |
| [the ts phenotype of reisolates from children inoculated with live cold-adapted influenza vaccine type a]. | using mutants of fowl plague virus (frv) which have single temperature-sensitive (ts) mutations in some genes, an analysis was carried out on reisolates from children of 3-6 years, vaccinated with a monovaccine from recombinant strains of influenza type a virus. the recombinants were obtained by crossing of current epidemic strains of subtypes a (hini) and a (h3n2) with the cold-adapted (xa) ts-donor of attenuation a/leningrad/134/47/57 (h2n2) from which they, as a rule, inherited 5 ts-mutations ... | 1990 | 1697128 |
| [various approaches to designing the functionally active determinants as illustrated by the influenza virus a(h3n2) hemagglutinin]. | hexapeptide lys-gly-pro-asp-ser-gly analogous to the immunodominant fragment 141-146 of the epitope a of the influenza virus a(h3n2) hemagglutinin is synthesized. conjugated with thyroglobulin and hemocyanine, the hexapeptide induced formation of highly specific antibodies with heterolytic properties in cba mice. antihexapeptide antibodies interact not only with the homologous antigen but also with hemagglutinin and influenza virus. choice of the hexapeptide sequence is discussed. | 1990 | 1700716 |
| anti-influenza virus activity of the compound ly253963. | the compound ly253963 (1,3,4-thiadiazol-2-ylcyanamide) inhibited the in vitro replication of representative influenza a and b viruses in madin-darby canine kidney (mdck) cells at concentrations of 1-3.2 micrograms/ml. the yield of an influenza a (h3n2) virus in primary rhesus monkey kidney (rmk) cells was inhibited at 0.1-0.3 micrograms/ml. however, similar concentrations were inhibitory for the growth of uninfected mcdk or rmk cells. combination drug studies generally found indifferent interact ... | 1990 | 2080866 |
| [isolation and comparative study of highly reproductive recombinant influenza a viruses with a high antibody sensitivity]. | the possibility of generating avid and highly reproductive recombinants of influenza a virus (h3n2, h3n1) using strain a/pr/8/34 (h1n1) as a donor of high reproductive activity was demonstrated. in the process of recombination, the transmission of the gene responsible for synthesis of avid hemagglutinin h3 from one virus variant to another provides for high avidity of recombinants. however, a possible influence of other influenza a virus genes on the manifestation of avidity cannot be ruled out. | 1990 | 2082547 |
| [studies of adaptation of influenza viruses to their replication in low temperature. i. biological properties]. | influenza a/h3n2/ virus strains derived from various isolations and replicated in lowered temperatures (37 degrees, 35 degrees, 33 degrees, 30 degrees) in chicken embryos were used for the study. an alteration of temperature optimum of neuraminidase activity was established after 12-15 passages of influenza virus in lowered replication temperature and it differed depending on tested strain. during adaptation process of viruses to lowered replication temperatures no correlation between neuraminid ... | 1990 | 2084448 |
| haemagglutination-inhibiting (hi) antibodies against strains of influenza a virus in horse and pig sera in nigeria. | sera from horses and pigs obtained from lagos and ibadan respectively were examined for haemagglutination-inhibiting (hi) antibodies to two strains each of h3n2 and h1n1 subtypes of influenza a virus. more horse sera had hi antibodies to the h3n2 than the h1n1 strains while pig sera reacted almost equally with strains of both subtypes. all the horse sera had hi antibodies to the two strains of h3n2 subtype (a/mississippi/1/85 and a/leningrad/360/86), while 87% and 14% of the horses examined were ... | 1990 | 2100750 |
| enhancement of anti-influenza a virus cytotoxicity following influenza a virus vaccination in older, chronically ill adults. | we studied anti-influenza cytotoxicity by bulk peripheral blood mononuclear leukocyte (pbl) cultures derived from older, chronically ill volunteers undergoing vaccination. vaccinees received either cold-recombinant, live-attenuated influenza a/korea/1/82 (h3n2) virus intranasally or inactivated monovalent influenza a/taiwan/1/86 (h1n1) subvirion vaccine intramuscularly. pbl were collected pre- and postvaccination and in vitro stimulated by autologous pbl infected with influenza a virus homologou ... | 1990 | 2123886 |
| a 36 nucleotide deletion mutation in the coding region of the ns1 gene of an influenza a virus rna segment 8 specifies a temperature-dependent host range phenotype. | previously a spontaneous 36 nucleotide deletion in the coding region of ns1 was detected in the ns gene of a reassortant virus (cr43-3) recovered from a dual infection by the influenza a/ann arbor/6/60 cold-adapted (ca) mutant and wild-type (wt) influenza a/alaska/6/77 (h3n2). the hemagglutinin, neuraminidase and ns genes were derived from the wild type virus parent while the other 5 genes were derived from the ca parent. the cr43-3 reassortant virus exhibited: (i) a host range (hr) phenotype, i ... | 1990 | 2138396 |
| analysis of influenza a virus temperature-sensitive mutants with mutations in rna segment 8. | temperature-sensitive (ts) mutants of influenza virus strain a/udorn/72 (h3n2 subtype) with lesions in rna segment 8 exhibited intrasegmental complementation, and were divided in two complementation groups (h1 and h2) on mdck cells. the nucleotide sequence of segment 8 was determined for three of these mutants. the h1 strains, icr1629 and spc45, have a single amino acid substitution in the coding region of the non-structural protein ns1, whereas the h2 strain, icr516, has a substitution in the n ... | 1990 | 2141068 |
| [surveillance of acute respiratory diseases in the 1988/1989 season in czechoslovakia]. | the authors submit an analysis of results of surveillance of acute respiratory diseases during the 1988/1989 season in the cssr. the influenza epidemic took place between the 4th and 11th calendar week with a peak in the 7th week. during the epidemic 19.7% of the population in the csr contracted the disease. the influenza epidemic was preceded by a high incidence of infections caused by a respiratory syncytia virus. as to the aetiology, influenza viruses subtypes a/h1n1/, a/h3n2/ and type b part ... | 1990 | 2144473 |
| [vaccinations in pigs]. | efficacious and safe gi-negative vaccines are available for vaccination against aujeszky's disease. an intensive vaccination programme carried out consistently will result in the reduction of virus circulating among pig populations. combined vaccination and culling of gi-seropositive pigs may lead to eradication of aujeszky's disease virus in a stock. vaccination of susceptible gilts, sows and boars against parvovirus infections is advisable. the actual period for which a sow is protected agains ... | 1990 | 2161569 |
| sero-epidemiological screening of pig sera collected at the slaughterhouse to detect herds infected with aujeszky's disease virus, porcine influenza virus and actinobacillus (haemophilus) pleuropneumoniae in the framework of an integrated quality control (iqc) system. | over a period of six months, approximately 4700 blood samples were collected from 97 pig-finishing farms in the provinces of noord-brabant and gelderland and screened for antibodies with respect to aujeszky's disease virus (adv), porcine influenza virus (pi) and actinobacillus (haemophilus) pleuropneumoniae (app). there were significant differences in the percentages of seropositive pigs between the two provinces, which may be related to the difference in the density of the pig population in the ... | 1990 | 2176752 |
| differential interaction of virulent and attenuated influenza virus strains with ferret alveolar macrophages: possible role in pathogenicity. | the ferret provides a unique model for the study of human influenza. the interaction between alveolar macrophages and virus strains with different levels of virulence was examined in vitro. the greater virulence of wild-type a strains over type b and c viruses was reflected in the higher production of infectious virus progeny and subsequent cytopathology, even though the expression of viral antigens was equivalent for all strains tested. these included a/ann arbor/6/60 (h2n2) and a/rochester/1/8 ... | 1990 | 2181032 |
| use of live cold-adapted influenza a h1n1 and h3n2 virus vaccines in seropositive adults. | to investigate the immunogenicity and protective efficacy of cold-adapted influenza vaccine in individuals with underlying immunity to influenza a virus, we administered cold-adapted h1n1 and h3n2 vaccines to adults with prevaccination serum hemagglutination inhibition antibody titers of 1:16 or more and challenged them 1 month afterwards with homologous wild-type influenza a virus. both cold-adapted vaccines were immunogenic in seropositive adults. in addition, individuals receiving cold-adapte ... | 1990 | 2182673 |
| effect of live attenuated, cold recombinant (cr) influenza virus vaccines on pulmonary function in healthy and asthmatic adults. | the effects of intranasal inoculation with live attenuated, cr influenza virus vaccines on pulmonary function in healthy and asthmatic adults were evaluated in placebo-controlled, double-blind studies. in 46 healthy adult volunteers, there were no statistically significant alterations in pulmonary function as measured by spirometry and histamine bronchoprovocation tests in the first week following monovalent cr influenza virus vaccine [type a (h3n2, h1n1) and type b]. among healthy adults with p ... | 1990 | 2194380 |
| comparison of live attenuated cold-adapted and avian-human influenza a/bethesda/85 (h3n2) reassortant virus vaccines in infants and children. | randomized, placebo-controlled studies with 10(3)-10(7) 50% tissue-culture infectious dose (tcid50) of avian-human (ah) and cold-adapted (ca) influenza a/bethesda/85 (h3n2) reassortant viruses were completed in 106 seronegative young children 6-48 months of age. although the reassortants differed in six of eight rna segments, they exhibited similar properties in level of attenuation, infectivity, immunogenicity, and efficacy. the 50% human infectious dose was 10(4.6) tcid50 for ah and 10(4.4) fo ... | 1990 | 2197335 |
| sensitive enzyme immunoassay for the rapid diagnosis of influenza a virus infections in clinical specimens. | samples of nasopharyngeal secretion (nps) from 100 infants and small children admitted for acute respiratory disease during the period from january to march 1989 were examined for the presence of influenza a virus. all samples were tested by enzyme immunoassay (eia), fluorescent antibody (fa) technique and by isolation in cell culture 3-6 h after they were obtained from the patients. of 24 influenza strains found by isolation, 21 were detected by eia and 19 were fa+. in comparison with virus iso ... | 1990 | 2203125 |
| functional role of respiratory tract haemagglutinin-specific iga antibodies in protection against influenza. | intranasal inoculation of haemagglutinin (ha) purified from influenza virus a/pr/8/34 (pr8, h1n1) together with cholera toxin b subunit, into balb/c mice resulted in complete protection against pr8 infection in parallel with the induction of high levels of ha-specific iga and igg antibodies on the respiratory tract. the respiratory tract iga and igg were purified from nasal and lung washings of the immunized mice using affinity columns, and their ha-specific activities were measured by enzyme-li ... | 1990 | 2251874 |
| crystallization and preliminary x-ray diffraction studies of a monoclonal antibody fab fragment specific for an influenza virus haemagglutinin and of an escape mutant of that haemagglutinin. | preliminary crystallographic data are given for two molecules involved in the interaction between the humoral immune response and the influenza virus. these molecules are the fab fragment of an antibody specific for the haemagglutinin of influenza virus strain x31 (hong kong 1/68 (h3n2)) and a mutant of x31 haemagglutinin that escapes recognition by that antibody. crystals of the haemagglutinin are isomorphous to those of x31, whose structure is known; they diffract to 3.4 a resolution. crystals ... | 1990 | 2258927 |
| [the primary structure of the hemagglutinin gene of strain a/riga/9977/86--a drift variant of influenza virus a(h3n2)]. | the hemagglutinin gene primary structure of influenza virus a/riga/9977/86 (h3n2) belonging to the "coen/84" antigenic subgroup was determined by primer sequencing. a comparative analysis confirmed that the reversions of amino acids in the late stages of the h3 influenza virus subtype antigenic drift became more frequent and the antigenic variants remained in epidemic circulation longer. the possible role of some mutations is discussed. | 1990 | 2267777 |
| [the characteristics of the hemagglutinin from persistent variants of the influenza virus a/victoria/35/72 (h3n2)]. | electrophoresis in polyacrylamide gel of the reference influenza a/victoria/35/72 (h3n2) virus and its persisting variants (pv) showed that the pv isolated on the 158th day from the moment of persistence modelling (pv158) had mutation in the gene of hemagglutinin (ha). this mutation is manifested by incomplete ha synthesis at 40 degrees c and increase of mobility of the light ha subunit (ha2). analysis of nucleotide sequence of the greater part of ha gene of pv158 virus revealed 5 nucleotide sub ... | 1990 | 2267778 |
| kinetic immunochemical studies of igg production during local and systemic anti-influenza immune response in rats. | the kinetics of anti-influenza igg antibodies in serum and nasal wash during the local and systemic immune response in rats was studied. the influenza virus a/hk/1/68 (h3n2) was injected by two different routes--intranasally and subcutaneously in the hind footpads. the proliferation of the ig-forming cells in the popliteal and paratracheal lymph nodes either local or distant according to the mode of virus administration was also studied. the results obtained during the primary and secondary immu ... | 1990 | 2273250 |
| characterization of antibody and cytotoxic t lymphocyte responses to human influenza virus h3 haemagglutinin expressed from the haemagglutinin locus of vaccinia virus. | antibody and cytotoxic t lymphocyte (ctl) responses to the haemagglutinin (ha) of human h3n2 influenza virus were analysed, using recombinant vaccinia viruses containing the influenza ha gene inserted into the ha gene locus of vaccinia virus. the recombinant vaccinia viruses elicited a high haemagglutination inhibiting (hi) antibody response to the homologous influenza virus in mice. in addition, hi antibody generated by the recombinant vaccinia virus reacted with antigenic variants of human h3n ... | 1990 | 2273387 |
| serum igg subclass antibody responses in children vaccinated with influenza virus antigens by live attenuated or inactivated vaccines. | to ascertain whether live attenuated or inactivated vaccines can be considered equivalent, we examined the primary antibody response of children following vaccination with influenza virus antigens in three different formulations. nine children received cold recombinant vaccine (crv) containing a/korea/82 (h3n2) and a/dunedin/83 (h1n1) variants. eight of these children responded to ha of the h3n2 subtype and the major portion of the elicited antibody was in the igg1 subclass. antibody of low tite ... | 1990 | 2275526 |
| safety and prophylactic efficacy of low-dose rimantadine in adults during an influenza a epidemic. | a placebo-controlled, double-blind study to evaluate the safety and prophylactic efficacy of a low dose (100 mg) of rimantadine hydrochloride against naturally occurring influenza in adults was conducted at two sites. after the onset of the influenza season, volunteers (ages, 18 to 55 years) were assigned randomly to receive rimantadine or placebo daily. subjects were monitored for adverse effects and evidence of influenza virus infection weekly for six weeks. only 10 (8.7%) of 114 rimantadine r ... | 1990 | 2285274 |
| independent and disparate evolution in nature of influenza a virus hemagglutinin and neuraminidase glycoproteins. | the hemagglutinin (ha) and neuraminidase (na) external glycoprotein antigens of h1n1 and h3n2 subtypes of epidemiologically important influenza a viruses prevalent during recent decades were subjected to intensive antigenic analysis by four different methods. prior to serological analysis with polyclonal rabbit antisera, ha and na antigens of four viruses of each subtype were segregated by genetic reassortment to forestall nonspecific steric hindrance during antigen-antibody combination. this an ... | 1990 | 2300562 |
| specificity and in vitro transfer of the immunosuppressive effect of detergent-disrupted influenza virus vaccine. | primed murine splenocytes give an in vitro antibody response to influenza whole virus vaccine (wvv), as measured by enzyme immunoassay (eia). when subunit vaccine (sv) of either influenza a or influenza b virus was added to in vitro splenocyte cultures stimulated with wvv, the eia antibody response to homologous wvv was reduced. this reduction in antibody response was observed when sv was prepared using zwitterionic detergent (empigen bb), non-ionic detergent (triton-x-100) or cationic detergent ... | 1990 | 2302839 |
| vaccination with inactivated influenza a virus during pregnancy protects neonatal mice against lethal challenge by influenza a viruses representing three subtypes. | a single intraperitoneal injection of pregnant mice with a monovalent formalin-inactivated influenza a virus vaccine protected their offspring against a lethal challenge dose of the same influenza a virus h3n2, h2n2, and h1n1 subtypes, as well as against challenge with the other two subtypes. degree of protection was vaccine dose related. cross-fostering of neonates indicated that protection was conferred by breast milk antibodies. serum virus-specific neutralizing antibodies in the mothers and ... | 1990 | 2304146 |
| cocirculation of two distinct evolutionary lineages of influenza type b virus since 1983. | during 1988-1989 two highly distinct antigenic variants of influenza type b were recognized in hemagglutination-inhibition tests with postinfection ferret serum. these viruses were antigenically related to either b/victoria/2/87, the most recent reference strain, or b/yamagata/16/88, a variant that was isolated in japan in may 1988. all influenza b viruses isolated in the united states during an epidemic in the winter of 1988-1989 were antigenically related to b/victoria/2/87. however, in severa ... | 1990 | 2309452 |
| direct sequencing of the ha gene of influenza (h3n2) virus in original clinical samples reveals sequence identity with mammalian cell-grown virus. | when influenza (h3n2) viruses from infected individuals are grown in embryonated chicken eggs, viruses are isolated which differ antigenically and structurally from viruses grown in mammalian madin-darby canine kidney (mdck) cell culture [g.c. schild, j.s. oxford, j.c. de jong, and r.g. webster, nature (london) 303:706-709, 1983]. to determine which of these viruses is most representative of virus replicating in the infected individual, a region of the ha gene of virus present in original clinic ... | 1990 | 2319652 |
| [influenza 1989/'90: a-h3n2 virus related to the vaccine virus]. | 1990 | 2320171 | |
| intracellular stability of the gene encoding influenza virus haemagglutinin. | the intracellular stability of the genome of noninfectious uv-irradiated influenza virus (a/wsn:h1n1) in dividing mdck cells was investigated using marker rescue techniques. the haemagglutinin gene could still be rescued by infection with a/x49 (h3n2) at 5 weeks postinoculation; its half-life was 13 days. | 1990 | 2327072 |
| synthesis and antiviral activity of metabolites of rimantadine. | the hydroxy metabolites of rimantadine (3-5) were synthesized and compared to amantadine (1) and rimantadine (2) for their ability to inhibit the replication of influenza viruses in vitro. all three metabolites were inhibitory to wild-type influenza a viruses (h3n2 and h1n1). in particular, 2-hydroxyrimantadine (3) showed similar activity to amantadine, but the 3- and 4-hydroxy metabolites (4 and 5, respectively), both of which are found in rimantadine-treated patients, showed only modest inhibi ... | 1990 | 2362279 |
| genome and antigenic analysis of influenza a (h3n2) viruses isolated from an epidemic in a closed community of carmelite nuns. | eighteen influenza a (h3n2) viruses were isolated during a single outbreak in a closed community of carmelite nuns. serological analysis of the virus haemagglutinin (has), using a panel of monoclonal antibodies, demonstrated antigenic microheterogeneity. in contrast, no significant biochemical differences were detected in viral genes by rna:rna hybridisation or in structural or nonstructural polypeptides analysed by high-resolution polyacrylamide gel electrophoresis (page) or by limited proteoly ... | 1990 | 2388044 |
| [the trypsin cleavage of hemagglutinin enhances the infectivity of the influenza virus in mice]. | mouse-pathogenic influenza a/aichi 2/68 (h3n2) grown in cell culture and having uncleaved hemagglutinin ha after treatment with trypsin underwent proteolytic shearing of ha (m.w. 75 kd) into two fragments: nal (60 kd) and ha2 (15 kd); its lethal effect on mice inoculated intranasally increased more than 200-fold. the virus treated with chemotrypsin underwent similar shearing of ha into hal and ha2; however, its lethal effect on mice was weak, analogous to that of intact virus with uncleaved ha. | 1990 | 2389564 |
| [the use of immunoenzyme analysis in studying the etiologic structure of influenza morbidity in 1985-1988]. | in the periods of epidemic increases in the incidence of influenza in 1985-1988, approximately 600 patients with clinical diagnoses of arvi and influenza were examined for the presence of viral antigen in nasopharyngeal washings by solid-phase enzyme-immunoassay and for antibody rises in paired blood sera. the use of modified speia and original test sera for influenza type a and b viruses in rapid diagnosis of influenza made it possible to decode the etiology of the epidemic situations in 1985-1 ... | 1990 | 2389565 |
| comparative long-term effects in a mouse model system of influenza whole virus and purified neuraminidase vaccines followed by sequential infections. | a comparison of inactivated whole influenza virus vaccine and purified influenza neuraminidase (na) in balb/c mice repeatedly challenged by homologous or heterologous h3n2 variant infections demonstrated an initial superiority of whole virus vaccine but the ultimate superiority of na vaccine in immunization after one or two boosting infections. parenteral administration of either vaccine followed by infection was much more effective than infection alone in the induction of either homologous or h ... | 1990 | 2401790 |
| [studies of the adaptation of influenza viruses to lowered temperatures of replication. ii. studies in vivo]. | swiss white mice were given intranasally suspension of influenza a virus (h3n2) isolated at different period of time and replicated in lowered temperatures in 11 days old chicken embryos. the presence of antigen in lung of animals was detected by if. they were given the virus replicated at 30 degrees c at different rate depending on strain tested. no distinct differences were observed in haemagglutination inhibition antibody level. on the other hand the level of neuraminidase activity inhibiting ... | 1990 | 1964991 |
| influenza a (h3n2) component of recommended vaccine induces antibody to current virus. | 1990 | 1967480 | |
| primary structure of the gene coding for the haemagglutinin of influenza virus a/leningrad/385/80(h3n2): detection of a point mutation responsible for the antigenic drift. | primary structure of the gene coding for haemagglutinin (ha-gene) of influenza virus a/leningrad/385/80(h2n2) isolated during the epidemics of influenza in leningrad in 1980 was determined. the close relationship of ha gene of this virus to the corresponding gene of the virus a/bangkok/1/79(h3n2) was confirmed. it was shown that a single mutation in an antigenic site (the change from isoleucine to leucine at position 51 of ha1 gene) caused an antigenic drift. one silent mutation was detected (nu ... | 1990 | 1980394 |
| influenza virus detection in clinical specimens. | the authors compared the results of influenza a (h1n1) and influenza a (h3n2) virus detection in nasopharyngeal swabs from flu patients by molecular hybridization (mh), elisa, virus isolation and seroconversion. using the immunofluorescence (if) technique influenza virus was detected in cell suspensions from the first chick embryo passage. altogether 63 swabs from various epidemic seasons were separated into 3 groups according to specimen sampling and storage. it was shown that influenza virus r ... | 1990 | 1981455 |
| 4-o-acetyl-n-acetylneuraminic acid in the n-linked carbohydrate structures of equine and guinea pig alpha 2-macroglobulins, potent inhibitors of influenza virus infection. | to investigate the molecular basis of the differential ability of human, equine, and guinea pig alpha 2-macroglobulins to inhibit hemagglutination and infectivity of a human influenza virus, a/memphis/102/72 (h3n2), the structures of oligosaccharides released from the three glycoproteins by hydrazinolysis were analyzed comparatively. approximately seven to eight sugar chains were released from each subunit of two potent inhibitors (equine and guinea pig alpha 2-macroglobulins) and a weak inhibit ... | 1989 | 2470764 |
| induction of immune response to influenza virus with anti-idiotypic antibodies. | anti-idiotypic (anti-id) antibodies were raised in rabbits against five monoclonal antibodies (mabs) specific for different antigenic sites on the hemagglutinin (ha) of influenza virus mem71h-beln (h3n1) [a/memphis/1/71 (h3n2) x a/bel/42 (h1n1)]. each of the anti-id sera was directed predominantly towards a unique (private) idiotype of the immunizing mab, none of the five idiotypes being detectable in pooled balb/c antisera against mem71h-beln virus or on most other anti-ha mabs tested. partial ... | 1989 | 2470919 |
| [antigenic drift of epidemic strains of influenza a virus (h3n2) in 1985]. | the study included 230 strains of influenza a (h3n2) virus isolated in the epidemic of 1985. a high degree of heterogeneity of the virus population was established with polyclonal sera, monoclonal antibodies and the method of krna-brna hybridization for the determination of the genome composition. among the strains of one epidemic (1985) three antigenically heterogenous groups of strains were detected similar with reference a/philippines/2/82, a/ken/1/84, and a/mississippi/1/85 strains. it was s ... | 1989 | 2471358 |
| [the use of the potentials of the molecular hybridization of nucleic acids as a method for the laboratory diagnosis of influenza in research on vaccinal infection]. | the data obtained as the result of the complex examination of volunteers immunized with live influenza vaccine, type a (h3n2), showed that the determination of the rna-containing structures by the method of the molecular hybridization of nucleic acids (mhna) was highly sensitive and reliable. this method proved to be more sensitive than common laboratory diagnostic tests (the isolation of the virus in chick embryos, the analysis of seroconversion, the antibody fluorescence test) and was not infe ... | 1989 | 2588878 |
| epidemiological aspects of the evolution of influenza infections in a large urban centre (b.) in romania in 1988. | the study describes the peculiarities of the influenza infection evolution, in 1988, in a large urban centre, b., in romania, as they result from the active surveillance of the epidemiological process of influenza and other viral respiratory tract infections, by means of a complex methodology based on clinical-epidemiological and laboratory techniques. the low endemic morbidity, the evolution of these seasonally ascendant specific incidence, the endemic aspect of influenza infection being mainta ... | 1989 | 2596018 |
| [regularities of formation in a general population of serum antibodies to previously circulated influenza a viruses]. | the spectrum of antibody production against hemagglutinin of all known influenza a virus serotypes after influenza a (h3n2) infection in persons of all age groups (from 1 month to 72 years) was analysed to investigated the regularities of accumulation of antibodies against influenza a viruses gone out of circulation. for the same purpose, a long-term (many years) longitudinal analysis of serum anti-ha antibody levels against "old" influenza a (hsw1n1), a (h0n1), a (h1n1), a (h2n2), and a (h3n2) ... | 1989 | 2609640 |
| [antigenic characteristics of influenza b virus strains isolated in an orphanage during an influenza outbreak in moscow in the winter of 1988]. | examinations of ard patients in an orphanage for defective children in moscow during an influenza outbreak in the winter of 1988 yielded 12 influenza virus strains, including 6 influenza b strains and 6 influenza a (h3n2) strains. the antigenic analysis of hemagglutinin of influenza b virus isolates showed that with respect to the b/leningrad/179/86 strain (an antigenic analogue of b/ann arbor/1/86 strain recommended for inclusion into the influenza vaccine for 1987-1988) they could be divided i ... | 1989 | 2609641 |
| characterization of the m protein and nucleoprotein genes of an avian influenza a virus which are involved in host range restriction in monkeys. | a reassortant virus possessing rna segment 7, which codes for the m1 and m2 proteins, of the avian influenza a/mallard/new york/6750/78 (h2n2) virus and the other seven rna segments of the human influenza a/udorn/307/72 (h3n2) virus had been shown previously to be markedly restricted in replication in the respiratory tract of squirrel monkeys. in contrast, a reassortant possessing segment 7 of another avian influenza virus, a/pintail/alberta/119/79 (h4n6), and the seven other rna segments from t ... | 1989 | 2609730 |
| prevalence of antibody to current influenza virus strains in adolescents. | during the spring of 1986, 118 pupils aged 15-18 years were surveyed for the presence of humoral antibodies to five influenza strains. prevalence of humoral immunity (hi) antibodies and immunity was found to be related to the year of the strain's emergence and to length of circulation time in the community. a high percentage of the adolescents were not immune to one or more of the tested strains. more than 40% of the studied group were not immune to the old a strains a/philipines 2/82 (h3n2) and ... | 1989 | 2621457 |
| [heterogeneity of current epidemic influenza a viruses with respect to reproduction activity in a tissue culture]. | the reproduction activity in human embryo kidney cell culture (hek) of epidemic influenza a viruses (h3n2 serosubtype) isolated in different years and with a certain level of virulence for man was studied. the cells were inoculated with the viruses at a multiplicity of infection of 0.001 eid50/cell, and the reproductive activity was judged by the levels of infectious and hemagglutinating activity during 96 hours of observation. there was a clear-cut correlation between the virus virulence level ... | 1989 | 2633460 |
| diagnosis of influenza a virus infections by detection of specific immunoglobulins m, a, and g in serum. | the value of immunoglobulin m (igm) detection in the early diagnosis of influenza a was examined in a prospective study during an outbreak of influenza a/philippines/2/82 (h3n2) virus infection in february and march 1986. the igm response was investigated in sera from 64 adults with influenzalike symptoms; we found a fourfold rise in titer or high titers (greater than or equal to 80) of influenza a virus antibodies by the complement fixation test. the igm response, analyzed by the hemadsorption ... | 1989 | 2654180 |
| recognition of the pb1, neuraminidase, and matrix proteins of influenza virus a/nt/60/68 by cytotoxic t lymphocytes. | we have investigated the recognition of the pb1, neuraminidase, and matrix (m1) proteins of influenza virus a/nt/60/68 (h3n2 subtype) by secondary in vitro stimulated polyclonal cytotoxic t lymphocyte (ctl) populations. while these three proteins have different functions and cellular locations, they can all be recognized as target antigens. however, the immunogenicity of these proteins for ctls is under strict genetic control. thus, pb1 protein is recognized as a cross-reactive target antigen by ... | 1989 | 2658303 |
| emergence and apparent transmission of rimantadine-resistant influenza a virus in families. | to determine whether rimantadine can protect family members from acquiring influenza a viral illness and to assess the possible selection of drug-resistant strains of virus, we conducted a randomized, double-blind, placebo-controlled study in three communities during two influenza seasons. when influenza a occurred in a family, the members (including the index patient) were given either rimantadine (adult oral dose, 200 mg per day) or placebo for 10 days. the presence of illness was monitored by ... | 1989 | 2687687 |
| natural or vaccine-induced antibody as a predictor of immunity in the face of natural challenge with influenza viruses. | a study of influenza in residential schools provided the opportunity to assess the significance of antibody as a predictor of immunity. five hundred and fifty-six pupils from 8 schools were included in the investigations, and the outcome for these children in 27 naturally occurring outbreaks of influenza was analysed. the outbreaks comprised 5 caused by strains of influenza a h3n2, 10 caused by strains of influenza a h1n1, and 12 caused by strains of influenza b. on 8 occasions a second outbreak ... | 1989 | 2703026 |
| effectiveness of influenza vaccine when given during an outbreak of influenza a/h3n2 in a nursing home. | an explosive outbreak of influenza a/h3n2 began in a nursing home in the denver area early in november, 1987. residents had not been vaccinated at that time. vaccine was administered on november 11th. two weeks after the vaccine was given, the attack rate differed between the vaccinated and unvaccinated individuals. there were 40 cases of influenza among the 98 elderly residents, 12 cases of pneumonia, and seven deaths. vaccine efficacy two weeks after it was given was estimated to be 65.4% in p ... | 1989 | 2703638 |
| effect of nitrogen dioxide exposure on susceptibility to influenza a virus infection in healthy adults. | the effect of no2 exposure and human susceptibility to respiratory virus infection was investigated in a placebo-controlled, randomized, double-blind trial conducted in an environmentally controlled research chamber over 3 yr. healthy, nonsmoking, young adult volunteers who were seronegative to influenza a/korea/82 (h3n2) virus were randomly assigned to breathe either filtered clean air (control group) or no2 for 2 h/day for 3 consecutive days. the no2 concentrations were 2 ppm (year 1), 3 ppm ( ... | 1989 | 2712434 |
| studies on the genetic basis of human influenza a virus adaptation to mice: degrees of virulence of reassortants with defined genetic content. | a highly virulent mouse-adapted variant of influenza virus a/aichi/2/68 (h3n2) was crossed either with the original a/ussr/90/77 (h1n1) influenza virus strain or with its mouse-adapted, moderately mouse virulent variant. the reassortants were characterized with respect to their genetic content and pneumovirulence for mice. the reassortants fell into three categories: avirulent, highly virulent (resembling in this respect the parent a/aichi/2/68 virus) and moderately virulent (resembling the mous ... | 1989 | 2719553 |
| pathways of evolution of influenza a (h1n1) viruses from 1977 to 1986 as determined by oligonucleotide mapping and sequencing studies. | the evolutionary relationships of epidemic influenza a (h1n1) viruses isolated between 1982 and 1986 have been examined by oligonucleotide mapping and partial dna sequencing. the t1 mapping studies confirmed our previous report that the evolution of the influenza virus genome generally results in an average of four to six oligonucleotide changes per year. between 1982 and 1986, however, two apparent exceptions to this finding occurred. h1n1 antigenic variants (including the a/chile/83 and a/vict ... | 1989 | 2732691 |
| mechanism of immunity to influenza: maternal and passive neonatal protection following immunization of adult ferrets with a live vaccinia-influenza virus haemagglutinin recombinant but not with recombinants containing other influenza virus proteins. | neonatal ferrets are protected against infection with influenza virus by milk-derived anti-influenza virus igg after suckling on an immune mother. live vaccines protect better than killed vaccines despite their stimulation of lower maternal haemagglutination-inhibiting antibody levels. this suggests that antibody to virus proteins other than the haemagglutinin may also be involved. to investigate this, adult ferrets were immunized intradermally with live vaccinia-influenza virus recombinants eac ... | 1989 | 2732721 |