| recommended composition of influenza virus vaccines for use in the 1991-1992 season. | | 1991 | 2018726 |
| insights into neutralization of animal viruses gained from study of influenza virus. | | 1991 | 2019292 |
| 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 |
| evolutionary relatedness of the predicted gene product of rna segment 2 of the tick-borne dhori virus and the pb1 polymerase gene of influenza viruses. | the complete nucleotide sequence of the second largest rna segment of dhori/india/1313/61 virus was determined and the deduced amino acid sequence was compared with the polymerase (p) proteins of influenza a, b, and c viruses. rna segment 2 (2224 nucleotides) of dhori virus contains a single long open reading frame that can encode a 716-amino acid polypeptide (81.3 kda). the predicted polypeptide shares between 27 and 31% sequence identities with the pb1 polypeptides of influenza a, b, and c vir ... | 1991 | 2024457 |
| antibodies to ha and na augment uptake of influenza a viruses into cells via fc receptor entry. | the hemagglutinin (ha) and neuraminidase (na) of influenza a viruses induce antibodies which augment the uptake of influenza a virus by antigen presenting cells via fc receptor entry. antibody-dependent enhancement of uptake of virus by cells was mediated by fc receptors because f(ab')2 preparations of lgg mixed with virus did not enhance virus uptake. the enhanced infection was measured using a fluorescent focus assay and was confirmed by dot-blot hybridization analysis. a 25-fold increase in t ... | 1991 | 2024464 |
| comparison of complete amino acid sequences and receptor-binding properties among 13 serotypes of hemagglutinins of influenza a viruses. | we determined the sequences of 7 serotypes (h4, h6, h8, h9, h11, h12, and h13) of hemagglutinin (ha) genes, which have not been reported so far. the coding regions consisted of 1692 nucleotides in h4, 1698 in h6, 1695 in h8, 1680 in h9, 1695 in h11, 1692 in h12, and 1698 in h13, and specified 564, 566, 565, 560, 565, 564, and 566 amino acids, respectively. by comparison of amino acid sequences, 13 ha serotypes could be divided into two families, i.e., an h1 group (h1, h2, h5, h6, h8, h9, h11, h1 ... | 1991 | 2024485 |
| 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 |
| the role of interleukin 4 in specific antibody responses by human b cells. | this study was designed to investigate the requirement for interleukin 4 (il-4) in specific antibody responses by human lymphocytes. addition of il-4 to antigen (influenza virus)-stimulated cultures of tonsillar mononuclear cells was found to suppress specific antibody production significantly at doses as low as 10 units/ml. specific immunoglobulin (igg), iga, and igm antibodies were all equally inhibited by il-4. inhibition of the antibody response with il-4 was completely abrogated by an il-4 ... | 1991 | 2025616 |
| the 45 pocket of hla-a2.1 plays a role in presentation of influenza virus matrix peptide and alloantigens. | amino acid substitutions were introduced into the 45 pocket of hla-a2.1 to determine the potential role of this structurally defined feature of class i molecules in viral peptide and alloantigen presentation. the 45 pocket lies below the alpha 1-domain alpha-helix and is composed of five amino acids, three of which differ between hla-a2.1 and hla-b37. these two class i molecules have previously been shown to have largely non-overlapping peptide-binding specificities. site-directed mutagenesis wa ... | 1991 | 2026879 |
| enhanced lymphoproliferation to influenza a virus following vaccination of older, chronically ill adults with live-attenuated viruses. | to question whether cellular immunity was stimulated by live-attenuated viruses in older, chronically ill adults, we intranasally inoculated 2 groups of volunteers (n = 37) with 2 different cold-recombinant, live-attenuated influenza a virus vaccines, and measured peripheral blood mononuclear cell responsiveness to influenza antigens and mitogen before and after vaccination. lymphocyte proliferation to vaccine virus and to heterosubtypic influenza a virus increased postvaccination even in the su ... | 1991 | 2028230 |
| guillain-barré syndrome and influenza vaccination in the us army, 1980-1988. | an increased incidence of guillain-barré syndrome (polyradiculoneuritis) occurred in individuals who received the a/new jersey (swine) influenza vaccine in 1976-1977. a retrospective study encompassing the years 1980-1988 was conducted to determine if the us army's mass influenza vaccination program has been associated with an increased incidence of guillain-barré syndrome in active duty soldiers during the study years. no temporally related increase in guillain-barré syndrome was found during t ... | 1991 | 2028981 |
| type a influenza viruses in waterfowl in ohio and implications for domestic turkeys. | because ducks are considered an important reservoir for type a influenza virus, and type a influenza viruses had not been recovered from ducks in ohio, a 3-year virus surveillance study was conducted in ohio waterfowl and waterfowl passing through ohio to determine if domestic turkeys were at risk of exposure to avian influenza (ai) viruses from the waterfowl reservoir. the prevalence of ai infections in ducks during the fall migration averaged about 5.9%. the 55 waterfowl-origin type a influenz ... | 1991 | 2029250 |
| influenza a and the virus associated haemophagocytic syndrome: cluster of three cases in children with acute leukaemia. | at the height of the united kingdom influenza a epidemic in december 1989, three children receiving treatment for non-t cell acute leukaemia developed pancytopenia with concomitant influenza a infection. bone marrow histology showed prominent marrow erythrophagocytosis by morphologically mature histiocytes, consistent with the picture of virus associated haemophagocytic syndrome (vahs). in two cases there was an initial spontaneous recovery, though recurrence of vahs developed in one case in ass ... | 1991 | 2030147 |
| [analysis of the reassorted influenza virus clone genome: data for use of ordered selection of rna segments]. | chicken embryonated eggs were coinfected with influenza a/fpv/rostock and a/fpv/weybridge strains. 25 plaque isolates were obtained from the mixed yield and their genetic content was analysed by polyacrylamide gel electrophoresis of h3-uridine-labelled vrna in a modified gel system. at least 18 clones out of 25 plaque isolates proved to be reassortants; however, only one among them contained the homologous rna-segments belonging to both parents. the results are in agreement with the concept of a ... | 1991 | 2030701 |
| the polyadenylation signal of influenza virus rna involves a stretch of uridines followed by the rna duplex of the panhandle structure. | appropriate rnas are transcribed and amplified and proteins are expressed after transfection into cells of in vitro-reconstituted rna-protein complexes and infection with influenza virus as the helper. this system permits us to study the signals involved in transcription of influenza virus rnas. for the analysis we used a plasmid-derived rna containing the reporter gene for chloramphenicol acetyltransferase (cat) flanked by the noncoding sequences of the ns rna segment of influenza a/wsn/33 viru ... | 1991 | 2033659 |
| single amino acid substitutions in the hemagglutinin can alter the host range and receptor binding properties of h1 strains of influenza a virus. | we have previously characterized an influenza a (h1n1) virus which has host-dependent growth and receptor binding properties and have shown that a mutation which removes an oligosaccharide from the tip of the hemagglutinin (ha) by changing asn-129 to asp permits this virus to grow to high titer in mdbk cells, (c. m. deom, a. j. caton, and i. t. schulze, proc. natl. acad. sci. usa 83:3771-3775, 1986). we have now isolated monoclonal antibodies specific for the mutant ha and have used escape mutan ... | 1991 | 2033664 |
| prevention and control of influenza recommendations of the immunization practices advisory committee (acip). | | 1991 | 2034207 |
| influenza type a and b infections in hospitalized pediatric patients. who should be immunized? | medical records of 99 hospitalized pediatric patients whose respiratory viral cultures yielded influenza type a or b during the winter of 1988/1989 were reviewed. we compared the records of patients considered to be at high risk (n = 43) with those of patients considered to be at low risk (n = 56) to determine differences in morbidity and mortality and if vaccination was warranted. sixty-six percent of high-risk patients had chronic pulmonary disease. forty-four percent of the high-risk and 11% ... | 1991 | 2035490 |
| possible involvement of lignin structure in anti-influenza virus activity. | commercial lignins suppressed the growth of influenza a virus infecting mdck cells, and the rna-dependent rna synthesis, as efficiently as the high-molecular weight fractions extracted from pine cone of pinus parviflora sieb. et zucc. the anti-influenza a virus activity of both pine cone extract and commercial alkali-lignin was considerably reduced by treatment with sodium chlorite, but was not affected by sulfuric acid or trifluoroacetic acid. the degraded components of lignin, various synthesi ... | 1991 | 2035999 |
| 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 |
| comparison of enzyme-linked immunosorbent assay, indirect immunofluorescence assay, and virus isolation for detection of respiratory viruses in nasopharyngeal secretions. | nasopharyngeal secretions obtained from 94 children with acute respiratory illness were examined for the presence of respiratory syncytial virus (rsv), adenovirus, and influenza virus type a by virus culturing (virus isolation technique [vit]), immunofluorescence assay (ifa), and enzyme-linked immunosorbent assay (elisa). similar results were obtained in at least two tests for rsv, influenza virus type a, and adenovirus in 92 (97.9%), 88 (93.6%), and 88 (93.6%) cases, respectively. both rapid vi ... | 1991 | 2037663 |
| comparison of directigen flu-a with viral isolation and direct immunofluorescence for the rapid detection and identification of influenza a virus. | directigen flu-a, an enzyme immunoassay membrane test, was compared prospectively to isolation in cell culture and direct immunofluorescence (if) for the detection of influenza a virus. one hundred ninety specimens were evaluated by directigen flu-a and cell culture; 184 of these specimens were also tested by direct if. the sensitivity of directigen flu-a compared to isolation in cell culture and direct if was 100%. the specificities of directigen flu-a compared to isolation and direct if were i ... | 1991 | 2037665 |
| 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 |
| human influenza virus hemagglutinin with high sensitivity to proteolytic activation. | to examine the prerequisites for cleavage activation of the hemagglutinin of human influenza viruses, a cdna clone obtained from strain a/port chalmers/1/73 (serotype h3) was subjected to site-directed mutagenesis and expressed in cv-1 cells by using a simian virus 40 vector. the number of basic residues at the cleavage site, which consists of a single arginine with wild-type hemagglutinin, was increased by inserting two, three, or four additional arginines. like wild-type hemagglutinin, mutants ... | 1991 | 2041080 |
| evolution of influenza a virus nucleoprotein genes: implications for the origins of h1n1 human and classical swine viruses. | a phylogenetic analysis of 52 published and 37 new nucleoprotein (np) gene sequences addressed the evolution and origin of human and swine influenza a viruses. h1n1 human and classical swine viruses (i.e., those related to swine/iowa/15/30) share a single common ancestor, which was estimated to have occurred in 1912 to 1913. from this common ancestor, human and classical swine virus np genes have evolved at similar rates that are higher than in avian virus np genes (3.31 to 3.41 versus 1.90 nucl ... | 1991 | 2041090 |
| equine h7n7 influenza a viruses are highly pathogenic in mice without adaptation: potential use as an animal model. | equine h7n7 influenza a viruses, representing a broad range of isolates, were lethal in mice without adaptation. after repeated passages, a/equine/london/1416/73 acquired neurotropism upon intranasal infection. thus, mice infected with equine influenza a viruses provide a model system for the study of highly virulent mammalian influenza viruses. | 1991 | 2041098 |
| the m2 protein of influenza a virus is acylated. | the m2 protein of influenza a virus, a 97 amino acid integral membrane protein expressed on the surface of infected cells, is covalently modified with long chain fatty acids. the fatty acid bond is sensitive to treatment with neutral hydroxylamine and mercaptoethanol, which indicates a labile thioester type linkage. thin-layer chromatographic fatty acid analysis of [3h]myristic and [3h]palmitic acid-labelled m2 protein shows that palmitic acid is the predominant fatty acid linked to this polypep ... | 1991 | 2045796 |
| new influenza virus in horses. | | 1991 | 2046764 |
| 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 |
| amantadine prophylaxis for health care workers: unanswered questions. | | 1991 | 2050586 |
| serological responses in volunteers to inactivated trivalent subunit influenza vaccine: antibody reactivity with epidemic influenza a and b strains and evidence of a rapid immune response. | a study of the immunogenicity of the inactivated trivalent subunit influenza vaccine for the 1989/90 season was performed in what proved to be an influenza epidemic year. one hundred student volunteers at the london hospital medical college participated in the study and the findings indicated that there was an excellent serological match between the epidemic strain of influenza a (h3n2) and the vaccine strain. before vaccination, the geometric mean titre (gmt) to a/england/308/89, a representati ... | 1991 | 2051142 |
| an influenza a virus containing influenza b virus 5' and 3' noncoding regions on the neuraminidase gene is attenuated in mice. | influenza a and b viruses have not been shown to form reassortants. it had been assumed that the lack of genotypic mixing between influenza virus types reflected differences in polymerase and packaging specificity. in this study, we show that an influenza a virus polymerase transcribes and replicates a chloramphenicol acetyltransferase (cat) gene flanked by the nontranslated sequences of an influenza b virus gene. although the transcription level of this cat gene was several times lower than tha ... | 1991 | 2052599 |
| influenza virus m2 integral membrane protein is a homotetramer stabilized by formation of disulfide bonds. | the oligomeric structure of the influenza a virus m2 integral membrane protein was determined. on sds-polyacrylamide gels under nonreducing conditions, the influenza a/udorn/72 virus m2 forms disulfide-linked dimers (30 kda) and tetramers (60 kda). sucrose gradient analysis and chemical cross-linking analysis indicated that the oligomeric form of m2 is a tetramer consisting of either a pair of disulfide-linked dimers or disulfide-linked tetramers. in addition, a small amount of a cross-linked sp ... | 1991 | 2053285 |
| protection of chickens from lethal influenza virus infection by influenza a/chicken/pennsylvania/1/83 virus: characterization of the protective effect. | the influenza a/chicken/pennsylvania/1/83 (h5n2) virus is the first known example of an influenza virus isolated from a natural infection which contained primarily defective interfering particles (t. m. chambers and r. g. webster, j. virol. 61, 1517-1523, 1987). in chickens, coinoculation of this virus together with the closely related but highly virulent influenza a/chicken/pennsylvania/1370/83 virus results in reduced mortality compared to virulent virus infection alone (bean et al., j. virol. ... | 1991 | 2053293 |
| evolution of pig influenza viruses. | there is evidence that the nucleoprotein (np) gene of the classical swine virus (a/swine/1976/31) clusters with the early human strains at the nucleotide sequence level, while at the level of the amino acid sequence, as defined by consensus amino acids and in functional tests, its np is clearly "avian like." therefore it was suggested that the sw/31 np had been recently under strong selection pressure, possibly caused by reassortment with other avian influenza genes, whose gene products have to ... | 1991 | 2053297 |
| imaging in influenza a encephalitis. | two cases of influenza a encephalitis seen during an outbreak of influenza types a/england/427/88 (h3n2) and a/taiwan/1/86 (h1n1) in december 1989 are described. in both children the encephalitis developed within three days of the respiratory symptoms and both became comatose within 48 hours. virological studies showed that the patients had had a recent influenza a infection. symmetrical localised hypodense lesions within the thalami and pons were demonstrated in both cases on computed tomograph ... | 1991 | 2053792 |
| single cell fusion events induced by influenza hemagglutinin: studies with rapid-flow, quantitative fluorescence microscopy. | fusion of individual human erythrocytes to fibroblasts expressing the influenza virus hemagglutinin cells were attached to coverslips fitted in a specially designed flow chamber mounted on a microscope stage, and fusion was triggered by rapid acidification to ph less than 5.2. fusion between single cell pairs was monitored by a fluorescence increase due to redistribution of fluorescent dyes between either membrane or cytoplasmic compartments of fusing cells. the single cell fusion events were br ... | 1991 | 2055263 |
| antibody recognition of an immunogenic influenza hemagglutinin-human leukocyte antigen class ii complex. | the a/japan/57 influenza hemagglutin (ha) peptide ha 128-145, when bound by human histocompatibility leukocyte antigen-drw11 cells, is recognized by the human cd4+ t cell clone v1. a rabbit antiserum has been raised against ha 128-145 which recognizes not only the free peptide, but also the ha 128-145/drw11 complex on a solid matrix, in solution, or on the surface of viable cells. the detection of these complexes on viable cells was shown to be class ii specific, drw11 restricted, and commensura ... | 1991 | 2056278 |
| the role of viruses and atypical organisms in the pathogenesis of adult pneumonia in papua new guinea. | the role of viruses and atypical organisms in pneumonia is well known in western populations, yet very little documentation is available about their role in pneumonia in developing countries. in a study of 175 adults with community-acquired pneumonia in papua new guinea, serological methods were used to assess this issue. five patients had high influenza a titres suggestive of recent infection. adenovirus titres rose significantly in one patient with haemophilus influenzae pneumonia, whilst no e ... | 1991 | 2058297 |
| peptide binding to class i mhc on living cells and quantitation of complexes required for ctl lysis. | antigenic peptides are presented to cd8+t lymphocytes by class i major histocompatibility complex (mhc) molecules. peptides specifically bind to purified class i molecules in vitro, and to class i molecules on cells at nonphysiological temperatures. we report here the kinetic and equilibrium parameters for the binding of radiolabelled influenza nucleoprotein peptides (np-y365-380 and shorter homologues) to the murine h-2db molecule on intact, viable cells at 37 degrees c. in contrast to earlier ... | 1991 | 2062379 |
| a new method for the purification of the influenza a virus neuraminidase. | a rapid new method for the purification of neuraminidase (na) heads from influenza a virus is described. virus was pelleted directly from allantoic fluid and was digested with pronase. the cores were removed by centrifugation, redigested and the released na heads were pooled and concentrated. the na was separated from all contaminating proteins in a single step on a superose 12 column. the purified material was suitable for both crystallography and for the production of monospecific antisera. | 1991 | 2066385 |
| 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 |
| influenza a infection with rhabdomyolysis and acute renal failure--a potentially fatal complication. | this paper describes a case of influenza a infection complicated by rhabdomyolysis and acute renal failure. this very rare complication is particularly important as symptoms may be non-specific and therefore ascribed to the underlying influenzal illness. | 1991 | 2068037 |
| invariant chain targets hla class ii molecules to acidic endosomes containing internalized influenza virus. | the role of the hla class ii-associated invariant chain in the intracellular trafficking of hla-dr molecules was examined in a transient expression system using hela cells. in the absence of alpha and beta polypeptides, invariant chain was retained in the endoplasmic reticulum (er). in the absence of invariant chain, intracellular alpha beta heterodimers could be detected only in the er and the golgi apparatus. however, when alpha and beta subunits were coexpressed with invariant chain, hla-dr m ... | 1991 | 2068076 |
| antiviral activities of 5-ethynyl-1-beta-d-ribofuranosylimidazole-4- carboxamide and related compounds. | a series of novel compounds, 5-alkynyl-1-beta-d-ribofuranosylimidazole-4- carboxamides, have been identified as broad-spectrum antiviral agents. 5-ethynyl-1-beta-d-ribofuranosylimidazole-4- carboxamide (eicar), the most potent congener of the group, showed antiviral potency about 10- to 100-fold greater than that of ribavirin. similar in spectrum to ribavirin, eicar was particularly active (50% inhibitory concentration, 0.2 to 4 micrograms/ml) against poxviruses (vaccinia virus), togaviruses (si ... | 1991 | 2069373 |
| electron microscopic evidence for the association of m2 protein with the influenza virion. | immunogold electron microscopy revealed that site-specific antibodies elicited by a synthetic peptide representing the n-terminal sequence (residues 2-10) of influenza virus m2 protein were capable of binding to the surface of virions. antibody binding was observed with two human influenza virus strains but not with an avian virus strain which has amino acid substitutions in the appropriate sequence of m2. these results provide direct evidence for the presence of m2 in the influenza virion. | 1991 | 2069504 |
| the genetic aspects of influenza virus filamentous particle formation. | we analysed the genetic content of reassortants between parent viruses differing in their ability to form filaments. the results suggest that primarily ha, m, and np genes are involved in the control of the filament forming ability. a lower buoyant density of the filamentous forms as compared to spherical particles allowed us to obtain a sufficiently pure population of filaments. a difference in the uv-inactivation kinetics between filaments and spherical virions suggests that the infectious fil ... | 1991 | 2069508 |
| presence of influenza virus-reactive glycophorins other than glycophorin a in human erythrocyte membranes. | the reactivities against seven hemagglutinins including influenza a and b viruses of six sialoglycoprotein (glycophorin) fractions, m-frs.1-3 and n-frs.1-3, separated from human oms and ons erythrocyte membranes by a combination of the lis-phenol method and gel filtration were studied. the serological results show that m-fr.1 and n-fr.1 were glycophorins am and an, respectively, the reactivities against influenza a and b viruses of both m-fr.2 and n-fr.2 which contained glycophorins b and c were ... | 1991 | 2069581 |
| influences of dietary restriction on immunity to influenza in aged mice. | our previous studies of the immune response of aged mice inoculated with influenza a virus revealed age-related decreases in antigen-specific cytotoxic t-lymphocyte function (ctl), t-cell proliferation, il-2 production, antigen presentation, and antibody production. because dietary restriction (dr) of rodents has been shown to extend maximum life span, delay the onset of tumors, and improve many immunologic parameters in aged animals, we tested the effect of such a regimen on the immune response ... | 1991 | 2071828 |
| nosocomial pneumonia in a canadian tertiary care center: a prospective surveillance study. | to determine the contribution of etiologic agents, including legionella pneumophila and respiratory viruses to nosocomial pneumonia at a tertiary care center. | 1991 | 2071878 |
| the ability of polymorphonuclear leukocyte priming agents to overcome influenza a virus-induced cell dysfunction. | the major mortality and morbidity resulting from influenza virus infections are due to secondary bacterial infections which occur in association with virus-induced inhibition of polymorphonuclear leukocyte (pmnl) function. the present study was undertaken to determine if compounds which prime pmnl function to subsequent stimulation with n-formylmethionyl-leucylphenylalanine (fmlp) or phorbol 12-myristate 13-acetate (pma) can overcome influenza a virus (iav)-induced inhibition of the pmnl chemilu ... | 1991 | 2072033 |
| evaluation of the anti-influenza virus activities of 1,3,4-thiadiazol-2-ylcyanamide (ly217896) and its sodium salt. | 1,3,4-thiadiazol-2-ylcyanamide (ly217896) and its sodium salt were shown to be effective against influenza a and b viruses in vitro and in the mouse model. in nondividing confluent mdck cells, the 50% inhibitory concentration of ly217896 ranged from 0.37 to 1.19 micrograms/ml against various strains of influenza a virus and from 0.75 to 1.54 micrograms/ml against various strains of influenza b virus, with no apparent cytotoxicity. however, at a concentration of 0.31 microgram/ml, ly217896 inhibi ... | 1990 | 2073106 |
| [inhibiting effect of various analogs of nucleoside-5'-triphosphates on rna synthesis, catalyzed by rna-polymerase of the influenza a virus]. | | 1990 | 2074892 |
| [the use of influenza vaccines and remantadine for protection against influenza in industrial enterprises]. | the effectiveness of inactivated and live influenza vaccines and remantidin was studied in persons with different annual morbidity rate in influenza and acute respiratory diseases (ard). after three and more years of immunization with the inactivated vaccine the number of seroconversions to viruses a (h1n1) and a (h3n2) in vaccinees decreased, respectively, from 75.0 to 26.0% and from 79.3 to 38.8%, and after an interval of two years or the alternation of inactivated and live vaccines the number ... | 1990 | 2075770 |
| the critical cut-off temperature of avian influenza viruses. | we have measured the pathogenicity for 6-week-old chicks of infection by h7 avian influenza viruses. one virus, strain s3 from a/fpv/rostock/34(h7n1) showed a temperature sensitive phenotype at 41.5 degrees c and reduced pathogenicity. by analysis of reassortants made between virus s3 and a/fpv/dobson/27(h7n7), a fully pathogenic virus, two conclusions arise. (1) the critical cut-off temperature for avian influenza virus in 6-week-old chicks is 41.5 degrees. (2) rna segment 1 of virus s3 is resp ... | 1990 | 2077784 |
| [surveillance of influenza in tananarive. 1989]. | the authors report results of epidemiological survey of influenza in tananarive. this survey is based on respiratory morbidity observed in an interprofessional health center, and virus isolation. two viruses have circulated in 1989: b virus (b/victoria/2/87) during first half-year, and a: a/victoria/36/88 (h1n1) virus during dry season with a pick in november. influenzae has been responsible of grouped sporadic cases without epidemic diffusion. | 1990 | 2078081 |
| [antiviral activity of berberine salts]. | | 1990 | 2080224 |
| 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 |
| dextran sulfate inhibits the fusion of influenza virus with model membranes, and suppresses influenza virus replication in vivo. | the effect of dextran sulfate and related compounds on the fusion of influenza a virus with model membranes, composed of dioleylphosphatidyl-choline and cholesterol (1:0.5), was investigated by a fusion assay based on de-quenching of fluorescence of octadecyl-rhodamine-hc1 (r18). dextran sulfate samples of molecular weight of 500,000, 8,000 and 5,000 were found to be potent inhibitors of the virus-liposome fusion process. polygalacturonic acid also showed anti-fusion activity, but to a lesser ex ... | 1990 | 2080868 |
| [persistence of the influenza virus in children with congenital cns pathology]. | sick infants born to mothers who experienced influenza during pregnancy were examined. the cerebrospinal fluid, serum and blood cells were collected from such children with signs of congenital immune deficiency and progressive pathology of the central nervous system. none of the specimens yielded infectious influenza virus, but by means of molecular hybridization virus-specific genetic sequences were found in small amounts in the cerebrospinal fluid and serum and in high concentrations in blood ... | 1990 | 2082545 |
| [effect of maternal virus-specific t-lymphocytes on pregnancy and fetal pathogenesis in experimental congenital influenza infection]. | inoculation of virus-specific cytotoxic lymphocytes (ctl) to pregnant mice infected with influenza virus was shown to result in a decrease of infectious virus concentration in the lungs and blood of mice as well as in the placentas and fetuses. with an increase in the dose of inoculated ctl, however, premature deliveries with stillbirths were observed as well as deaths of the mice, the highest frequency of fetal deaths being observed after infection of pregnant mice in the first half of pregnanc ... | 1990 | 2082546 |
| [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 |
| [primary structure of the hemagglutinin gene in strains of the influenza virus a/leningrad/624/86 and a/leningrad/621/86 serologic subtype h1n1]. | a molecular analysis was made of genomes of influenza a (h1n1) virus strains, the causative agents of an epidemic in leningrad, 1986. the primary structure of hemagglutinin gene of two of these strains, a/leningrad/624/86 and a/leningrad/621/86, was established, as well as partial primary structure of pb1 gene of certain current strains of the a (h1n1) subtype. a hypothesis of a "shift" of pb1 gene in 1950-1957 is suggested. | 1990 | 2082548 |
| [demonstration of the influenza virus a rna by nucleic acid molecular hybridization using biotin-treated probes]. | a probe containing full-size dna copy of influenza a/ussr/90/70 virus protein gene m labeled with biotin on 32p was used for influenza a virus rna detection by dot hybridization method. for labeling with biotin, a new method of its administration by chemical modification of nucleic acid was employed. in homologous dna:dna hybridization the sensitivity of determinations was less than 1 pg in the biotin-treatment of the probe and 1.25 pg in its radioactive labeling. hybridization of dna probe with ... | 1990 | 2082549 |
| [the role of myxovirus neuraminidase in the interferon induction system]. | interaction of myxovirus neuraminidases, in particular, that of influenza virus, with interferon (ifn) was established. when ifn is treated with viral neuraminidases, its antiviral activity tested in tissue culture does not change but it is eliminated from the body by the kidneys much more intensively and is more absorbed by the liver than native ifn. the degree of ifn elimination from the body is directly related to the level of enzymatic activity of viral neuraminidases affecting interferon. t ... | 1990 | 2082552 |
| abortive replication of influenza a viruses in hela 229 cells. | several experimental data support the idea that certain mammalian cells are unable to replicate influenza viruses type a, although these viruses can efficiently penetrate the cells. this cannot be attributed to a lack of specific receptors on the cell surface, but depends upon the failure of specific step(s) to occur during viral growth. here we report a study of abortiveness of human and avian type a influenza viruses in hela 229 cells. viral polypeptide synthesis was monitored by [35s]methioni ... | 1990 | 2082619 |
| persistence of influenza a by continuous close-contact transmission: the effect of non-random mixing. | the interaction of two populations has variable effects on the nature and duration of epidemic activity, depending on the transmissibility of the virus, the susceptibility of the population, migration, birth and death rates, and the initial number of cases. under circumstances where transmission stops in a single population (the infectious contact number is less than or equal to one), transmission may continue indefinitely when two populations interact under many different parameter combinations ... | 1990 | 2083993 |
| [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 |
| [the role of respiratory tract viruses in the etiology of obstructive bronchitis in infants]. | out of 524 children with acute respiratory infections in 141 obstructive bronchitis was diagnosed (ozo). seventy cases could be linked to viral infection. viral infections tested (influenza virus a, b, parainfluenza typ 1-3, rsv, adenoviruses) were more frequently associated with ozo than other acute respiratory infections of unknown etiology. majority infections induced by influenza virus a and parainfluenza virus typ 2 were accompanied by ozo symptoms. of the highest risk of acquiring ozo desp ... | 1990 | 2084449 |
| enhancement of chicken lymphocyte activation and lymphokine release by avian influenza virus. | we had previously found that inactivated avian influenza virus (aiv) could enhance the response of chicken lymphocytes to mitogen or antigen activation. an investigation into the possible mechanisms of this enhancement was undertaken. peripheral blood lymphocytes (pbl) were incubated with aiv expressing different hemagglutinin (ha) types (h1-h13) along with doses of concanavalin a (con a) which induce maximum (0.5 microgram) or submaximum (0.125 microgram) pbl activation. the lymphocyte activati ... | 1990 | 2086273 |
| [the isolation of the influenza virus and primary care]. | | 1990 | 2087115 |
| temperature-dependent kinetics of the activities of influenza virus. | the temperature dependence of membrane interactions between pr8 influenza virus and virus receptor (gd1a)-containing liposomes was studied. for quantitation, the octadecylrhodamine b chloride (r18) membrane marker was incorporated into liposomes at quenched concentrations. upon interaction with target membranes, the marker gets diluted, and dequenching can be measured in a fluorescence spectrophotometer. rate constants were calculated from the dequenching curves under low ph conditions, which al ... | 1990 | 2088451 |
| the kinetics of peptide binding to hla-a2 and the conformation of the peptide-a2 complex can be determined by amino acid side chains on the floor of the peptide binding groove. | the ability of amino acid side chains in the floor of the peptide binding groove of hla-a2 to affect the presentation of a viral peptide to peptide-specific cytotoxic t lymphocytes (ctl) has been examined. hla-a2 molecules with naturally occurring single amino acid substitutions of phe to tyr at position 9 (hla-a2.4a, tyr9) and tyr to cys at position 99 (hla-a2.4b, cys99) and a site directed mutant with a val to leu substitution at position 95 (leu95) were examined for their ability to present t ... | 1990 | 2088485 |
| [high performance liquid chromatography and characterization of structural proteins of the influenza virus]. | constituent proteins of human influenza virus a have been separated by reverse-phase hplc on polysil ods-500. their homogeneity is confirmed by the data of amino acid composition, edman analysis and gel electrophoresis. | 1990 | 2090114 |
| sialyloligosaccharides of the respiratory epithelium in the selection of human influenza virus receptor specificity. | human h3 strains of influenza a virus preferentially bind cell-surface oligosaccharides containing the sequence neuac alpha 2,6gal, while avian influenza strains preferentially recognize the sequence neuac alpha 2,3gal. the distribution of these two types of sialic acid linkages on host respiratory epithelium, the target of influenza infection, may be a factor in the selection of the different receptor specificities observed in human and avian influenza strains. to examine the distribution of th ... | 1990 | 2091044 |
| does exposure to cs gas potentiate the severity of influenza? | | 1990 | 2095429 |
| [the possibility of the circulation of vaccinal influenza a viral strains in the biosphere]. | | 1990 | 2097126 |
| [acute respiratory infections of viral origin in the children of algiers, algeria based on a seroepidemiological study]. | 401 double serum samples from 0 to 14 year old children with acute respiratory diseases (ard) were analysed in view to establish the viral etiology. 198 (49.4%) out of the 401 were positive. the syncytial respiratory virus (srv) was the most frequent (29.8%) among the positives, followed by the parainfluenzae virus type 3 (24.7), the influenza a virus (23.7%), the parainfluenzae type 1 (8.5%), the influenza b (7%) and the parainfluenza type 2 (2%). seven samples out of 109 were positive for aden ... | 1990 | 2099830 |
| [the virological study of a certified focus of acute respiratory diseases in a half-closed community]. | an acute respiratory disease outbreak appeared during february and march 1988 in a half-closed community. virologic investigations were conducted and an influenza virus type b strain was isolated, antigenically like b/victoria 2/87. administration of the anti-influenza vaccine in the fifth day of the outbreak evolution led to considerable reduction of the new cases and to outbreak extinction after 48 hours. | 1990 | 2099831 |
| 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 |
| [profile of influenza viruses in poland 1986-1990]. | during the years 1986 through 1990 we isolated 69 strains of influenza viruses of which 43 were a(h3n2), 22--a(h1n1) and 4 b strains. influenza a(h3n2) viruses isolated in 1986, 1988, 1989 and 1990 were similar to a/mississippi 1/85, a/inverness 3491/85, a/sichuan 2/87 and a/oms 5389/88. influenza a(h1n1) viruses isolated in 1987 and 1989 were similar to a/taiwan 1/86 and a/singapore 6/86 strains. influenza b viruses isolated in 1988 were similar to b/victoria 2/87 and b/beijing 1/87 strains. | 1990 | 2100811 |
| sialidase activity in rimantadine-resistant and -sensitive influenza a viruses. | rimantadine-resistant and -sensitive influenza a variants were assayed for their sialidase (neuraminidase, ec 3.2.1.18) activity. the kinetic parameters determined (ph optimum, stability against different ph values, thermal stability, activity on methylumbelliferyl-alpha-d-n-acetylneuraminic acid, n-acetylneuraminyl-lactose, fetuin and bovine submandibular gland mucin as substrates, km with the former substrate, inhibition by two competitive inhibitors, and behavior towards amantadine) revealed ... | 1990 | 2101800 |
| [community viral pneumonia in the adult population: a prospective multicenter study of 62 cases. the pneumonia study group of the community of valencia]. | the present work prospectively analyzes, in a multicentric study, viral pneumonias acquired in the community during one year. were studied 510 patients diagnosed of pneumonia in hospital, or whom 62 (12.1%) had a viral origin. influenza virus a and b were the most common causative agents (47.6% and 20.6% respectively). smoking habit was present in 44% of patients, previous ocfa in 45% and other previous pathology in 64.4%. the greatest number of registered cases was during december. the most fre ... | 1990 | 2102533 |
| polymer-metal complexes of protein antigens--new highly effective immunogens. | the mechanism of interaction of the copolymers n-vinylpyrrolidone-acrylic acid and n-vinylpyrrolidone-maleic anhydride with bovine serum albumin, influenza virus total surface antigen (haemagglutinin and neuraminidase), and the bcg protein fraction in the presence of divalent copper ions was investigated. novel water-soluble triple polymer-metal complexes of the above protein antigens were formed. these complexes showed high immunogenicity and conferred high levels of immunological protection. s ... | 1990 | 2103830 |
| immunological effects of tumor vaccines: ii. t cell responses directed against cellular antigens in the viral oncolysates. | peripheral blood mononuclear cells (pbmc) from patients with epithelial adenocarcinoma of the ovary treated in vivo with tumor vaccines administered as viral oncolysates (vo) exhibited significant proliferative responses in vitro to vo as well as to cellular oncolysates (co). these responses were dependent on the concentration of vo or co. vo consisted of lysates from the same ovarian tumor cell lines 2774 and caov3 infected in vitro with the avirulent strain of influenza virus a/pr8/34. co were ... | 1990 | 2103838 |
| update: influenza activity--united states, 1989-90. | | 1990 | 2104957 |
| failure of influenza vaccine to prevent two successive outbreaks of influenza a h1n1 in a school community. | forty nine of the 149 boys (33%) at a preparatory school fell ill at the beginning of the autumn term 1986 with symptoms of influenza. one hundred and eighty two of the 470 pupils (39%) in the senior part of the same school had similar symptoms of influenza at the beginning of the spring term 1987. a new variant of influenza a h1n1 virus was isolated from both outbreaks and shown to be antigenically similar to a/taiwan/1/86. the attack rate among pupils who had previously received trivalent infl ... | 1990 | 2107831 |
| v region gene usage and somatic mutation in the primary and secondary responses to influenza virus hemagglutinin. | most (80 to 90%) primary antibodies specific for the sb site of influenza virus (a/pr/8/34) hemagglutinin share an id (designated c4). secondary antihemagglutinin(sb) antibodies also exhibit the c4 id although less frequently (10 to 15%). we have analyzed the v region nucleotide sequences of primary and secondary antibodies with the c4 id. primary c4 antibodies are encoded by the same vk gene, belonging to the vk8 group, usually rearranged to jk5. the h chains are diverse, encoded by vh genes be ... | 1990 | 2108213 |
| in vitro virucidal effectiveness of a 0.12%-chlorhexidine gluconate mouthrinse. | the purpose of this work was to assess the in vitro antiviral effectiveness of a mouthrinse (peridex) containing 0.12% chlorhexidine gluconate (ch) on several viruses that are associated with the oral cavity. these included herpes simplex virus (hsv), cytomegalovirus (cmv), influenza a, parainfluenza, polio, and hepatitis b (hbv). virucidal assays in tissue cultures were performed on all viruses except hbv. the virucidal effect on hbv was assessed by inactivation of the dna polymerase contained ... | 1990 | 2109001 |
| [serological and epidemiological characteristics of acute pneumonias caused by mycoplasma pneumoniae in belgorod]. | the etiology of the outbreaks of acute pneumonia in belgorod was established and their epidemiological features were studied. the mycoplasmal etiology of all cases of acute pneumonia in children and adults, appearing alongside acute respiratory infections resulting from the preceding outbreaks caused by influenza viruses a/prague/, b/leningrad/369/75, and all types of parainfluenza viruses, was shown. the droplet mechanism of the transfer of infection was established, which was confirmed by the ... | 1990 | 2111621 |
| [diagnosis of influenza virus type a and b infections]. | | 1990 | 2113124 |
| human neutrophil stimulation by influenza virus: relationship of cytoplasmic ph changes to cell activation. | we have previously demonstrated that influenza a virus (iav) stimulates the human neutrophil through phospholipase c activation. with the use of the fluorescent indicator 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (bcecf), cytoplasmic acidification and subsequent alkalinization are shown to accompany this activation. these responses are not inhibited by pertussis toxin (pt). the alkalinization is mediated largely *but not entirely) by the na(+)-h+ antiporter and is not initiated, or modulate ... | 1990 | 2113768 |
| increased virulence of a mouse-adapted variant of influenza a/fm/1/47 virus is controlled by mutations in genome segments 4, 5, 7, and 8. | to cause disease, influenza virus must possess several genetically determined abilities that mediate stages in pathogenesis. the virulent mouse-adapted variant a/fm/1/47-ma (fm-ma), derived from the avirulent a/fm/1/47 (fm) strain, had acquired mutations in genes that control virulence. the purpose of this study was to identify those genes that had mutated to result in increased virulence and to obtain viruses that differed in virulence because of differences in individual genome segments. the g ... | 1990 | 2117072 |
| a set of closely related antibodies dominates the primary antibody response to the antigenic site cb of the a/pr/8/34 influenza virus hemagglutinin. | approximately 50% of the primary antibody response of balb/c mice to the a/pr/8/34 influenza virus hemagglutinin is directed to the cb site, one of the four major antigenic regions of the molecule. to determine the structural basis of the anti-cb site response, we have examined the paratypic and genetic diversity exhibited by a panel of 24 primary and 4 secondary response mab specific for this antigenic region. reactivity pattern analysis demonstrated 20 distinct fine specificities among these a ... | 1990 | 2118933 |
| defects in antigen presentation of mutant influenza haemagglutinins are reversed by mutations in the mhc class ii molecule. | a functional analysis was undertaken of the effects of mutating single amino acid residues in the alpha chain of the i-ak molecule (to alanine; residues 50-79) on the ability of i-ak transfectants to process and present influenza haemagglutinin to cd4+ t cell clones specific for two major antigenic sites of the ha1 subunit. in each instance, t cells were insensitive to a majority of substitutions in ak with the exception of a few critical residues that differed for individual t cell clones. but ... | 1990 | 2123452 |
| influenza surveillance--wales, 1988-89. | important functions of influenza surveillance include early detection of epidemics-enabling immunization of persons not previously covered by routine immunization programs, notification of health providers to prepare for the possible impact on clinical workloads and hospital admissions, and characterization of prevalent strains to permit the timely production of appropriate vaccines. in 1986, a general-practice-based surveillance system was established in wales to facilitate reporting of infecti ... | 1990 | 2123515 |
| 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 |
| structural homologies between two hla b27-restricted peptides suggest residues important for interaction with hla b27. | recently we described an hla b27-restricted peptide derived from hiv gag p24 protein. in this study we have isolated an hla b27-restricted peptide from the nucleoprotein (np) of influenza a virus. the shortest fragment recognized by cytotoxic t lymphocyte (ctl) is eight amino acids long, residues 384-391. comparison of the sequence of these two hla b27 restricted peptides reveals homologies which can be aligned from one peptide to the other. of the eight residues, two are identical: tryptophan a ... | 1990 | 2126195 |
| translational control in influenza virus-infected cells. | influenza virus type a has been shown to establish a translational control system such that during infection there is a dramatic inhibition of host cell protein synthesis and viral mrnas are selectively and efficiently translated. the following review summarizes the complex strategies employed by influenza to accomplish these goals. these include: (i) preventing newly made cellular mrnas from entering the cytoplasm of infected cells; (ii) inhibiting the initiation and elongation steps of transla ... | 1990 | 2133654 |