| from the centers for disease control. influenza activity--united states, 1991-1992. | | 1992 | 1727510 |
| a new method for reconstituting influenza polymerase and rna in vitro: a study of the promoter elements for crna and vrna synthesis in vitro and viral rescue in vivo. | the influenza rna polymerase is known to catalyse three distinct copying activities: (i) transcription of minus-sense virion rna (vrna) into mrna, (ii) transcription of vrna into full-length complementary rna (crna), and (iii) transcription of crna to vrna. ever since the discovery of the conserved 13 and 12 long sequences at each end of all the influenza rna segments, these have been good candidates for promoters of transcription. by devising a new, simple method for preparing influenza polymer ... | 1992 | 1727600 |
| composition of the helical internal components of influenza virus as revealed by immunogold labeling/electron microscopy. | the composition of the large helical internal components of influenza virus was investigated by immunogold labeling/electron microscopy with antibodies to the nucleoprotein (np), matrix protein (m), and polymerase complex (pb1, pb2, and pa) of the virus. the morphologically intact helices, obtained by air-drying of the virions on the electron microscope grid, showed little or no labeling with any of the above antibodies. however, partial to full degradation of the helix by proteinase k (2 ng/ml) ... | 1992 | 1727605 |
| isolation of matrix protein m1 from influenza viruses by acid-dependent extraction with nonionic detergent. | influenza viruses were disrupted layer by layer with the nonionic detergent np-40 at fixed ph. treatment of the virions with np-40 at neutral or mildly alkaline ph (6.8-8.0) yielded viral core structures containing m1 protein. the matrix m1 protein was selectively extracted from cores at acidic ph 3.0-4.5 with citrate, acetate, and phosphate buffers or with morpholinoethanesulfonic acid. the resulting m1 protein sedimented in a glycerol gradient with a coefficient of 2.8 s and most likely existe ... | 1992 | 1727609 |
| oligomeric organization and strain-specific proteolytic modification of the virion m2 protein of influenza a h1n1 viruses. | the m2 protein of influenza a h1n1 strains pr8, ws, and wsn is present in homooligomeric forms in virions grown in the allantoic cavity of embryonated eggs. the bulk of the virion m2 is detected as tetramers and dimers. the oligomeric forms of pr8 virions differ from those of ws and wsn not only in apparent molecular weight (mw) but also in that they seem to be composed of two types of monomers differing in mw by approximately 1.5 kda. evidence from monoclonal antibody binding (or lack of it) an ... | 1992 | 1727610 |
| endogenous loading of hla-a2 molecules with an analog of the influenza virus matrix protein-derived peptide and its inhibition by an exogenous peptide antagonist. | episomal plasmids (p8901) with minigenes coding for the influenza virus matrix peptide amino acids 57-68 (kgilgfvftltv; referred to as m57-68) or coding for a modified peptide were introduced into hla-a2-positive target cells. the association of these peptides, synthesized in the cytoplasm, with hla-a2 and the expression of this complex at the cell surface was evaluated with hla-a2-restricted ctl specific for the influenza virus matrix peptide m57-68. cells expressing m57-68 were lysed effective ... | 1992 | 1727876 |
| from the centers for disease control. control of influenza a outbreaks in nursing homes: amantadine as adjunct to vaccine--1989-1990. | | 1992 | 1727945 |
| from the centers for disease control. update: influenza activity and vaccine availability--united states, 1991 and 1992. | | 1992 | 1727946 |
| in situ detection of autoanti-idiotype antibody-forming cells induced by influenza virus infection. | in situ immunocytochemical-staining methods combined with computer-aided image analysis were employed to examine autoanti-idiotype antibody-forming cell expansion in vivo. autoanti-idiotype antibody-forming cells were demonstrated in the spleens of c57bl/6j (b6) strain mice intranasally infected with the influenza virus a/hong kong/168/(h3n2)[r] x-31. autoanti-idiotype b cells were detected and elevated in spleen tissues after secondary influenza infections compared to normal b6 mice, and were s ... | 1992 | 1728964 |
| the effect of influenza vaccination on il2 production in healthy elderly: implications for current vaccination practices. | age-related senescence of t-cell mediated responses is well recognized. this study was designed to determine how aging affects the t-cell mediated interleukin 2 (il2) response to influenza vaccination. a group of healthy elderly individuals were compared to a control group of healthy young adults for their response to the 1990 influenza vaccine. cultures of peripheral blood mononuclear cells (pbmc) were prepared from venous blood samples taken prevaccination (pre) and 8 and 12 weeks post-vaccina ... | 1992 | 1730850 |
| in vivo t cell activation, in vitro defective il-2 secretion, and response to influenza vaccination in elderly women. | il-2 secretion in response to mitogenic stimulation, assayed in vitro, is significantly reduced in circulating t lymphocytes isolated from healthy old people, but the significance of this abnormality and how it relates to in vivo il-2 secretion remain unclear. we found that il-2 secretion in response to pha plus pma by peripheral blood t cells isolated from 10 out of 32 (31%) healthy old individuals (mean age 86 yr, range 74-97) was significantly decreased compared with results obtained in 23 yo ... | 1992 | 1730868 |
| impact of influenza virus infection as a cause of pediatric hospitalization. | from winter 1989 to spring 1990, a severe epidemic caused by influenza a (h3n2) and b viruses developed in japan. during the epidemic (december 1989 to february 1990), 244 children were admitted to the pediatric ward of nippon kokan hospital: 53 (21.7%) were hospitalized with influenza virus infection, 22 (9.0%) with rotavirus gastroenteritis, and 17 (7.0%) with respiratory syncytial virus infection. among those with influenza, 24 had type a and 29 had type b. most were young healthy children wi ... | 1992 | 1730904 |
| fusion activity and inactivation of influenza virus: kinetics of low ph-induced fusion with cultured cells. | the kinetics of fusion of influenza virus (a/pr/8/34) with human promyelocytic leukaemia (hl-60), human t lymphocytic leukaemia (cem) and murine lymphoma (s49) cells were investigated. fusion was demonstrated by electron microscopy, and monitored by fluorescence dequenching of octadecylrhodamine incorporated in the virus membrane. rapid fusion was induced upon mild acidification of the medium. at ph 5, all virus particles were capable of fusing with the cells. the initial rate and the extent of ... | 1992 | 1730942 |
| hemagglutinin mutations related to antigenic variation in h1 swine influenza viruses. | the hemagglutinin (ha) of a recent swine influenza virus, a/sw/in/1726/88 (h1n1), was shown previously to have four antigenic sites, as determined from analysis of monoclonal antibody (mab)-selected escape mutants. to define the ha mutations related to these antigenic sites, we cloned and sequenced the ha genes amplified by polymerase chain reaction of parent virus and mab-selected escape mutants. the genetic data indicated the presence of four amino acid changes. after alignment with the three- ... | 1992 | 1731091 |
| a novel particulate influenza vaccine induces long-term and broad-based immunity in mice after oral immunization. | the immunogenicity of a novel particulate oral influenza vaccine was examined in terms of antibody response and protection in mice. oral immunization with chicken erythrocytes (crbc) adsorbed with gamma-irradiated influenza a virus induced high levels of immunoglobulin g antibodies and protection in the lung compared with gamma-irradiated virus administered alone or crbc. immunoglobulin a antibodies were the predominant antibodies in nasal washings, and their presence did not correlate with prot ... | 1992 | 1731094 |
| defective interfering influenza virus inhibits immunopathological effects of infectious virus in the mouse. | mice inoculated intranasally with a lethal dose of standard influenza virus die with an immune-mediated pneumonia but are protected by coinoculation with defective interfering (di) virus. here we show that recruitment of immune cells into the infected lung is halved by treatment with di virus although the cd4+/cd8+ cell ratio is not affected. responsiveness of lung t and b cells to lectins is inhibited by standard virus, but coinoculation of mice with di virus causes a 13-fold increase in t-cell ... | 1992 | 1731097 |
| update: influenza activity--united states, 1991-92 season. | from october 23, 1991, through january 18, 1992, 46 state health departments reported regional or widespread influenza activity for 1 or more weeks. for the week ending january 4, 34 states reported regional or widespread activity, the most during any single week this season. from late october through mid-december, influenza outbreaks reported from 11 states involved primarily school children. reports of outbreaks among adults began in mid-november and continued through january and involved pers ... | 1992 | 1731184 |
| a recombinant sporozoite surface antigen of theileria parva induces protection in cattle. | at present immunization against theileria parva is by infection with live sporozoites and simultaneous treatment with a long-acting oxytetracycline. this method has major limitations in that live organisms are used and the immunity engendered is parasite stock specific. in an attempt to develop an alternative immunization procedure, the gene encoding p67, a major surface antigen of sporozoites, has been expressed by using the plasmid expression vector pmg1. the gene, which has been characterized ... | 1992 | 1731322 |
| flanking sequences influence the presentation of an endogenously synthesized peptide to cytotoxic t lymphocytes. | cytotoxic t lymphocytes (ctl) recognize class i major histocompatibility complex molecules complexed to peptides of eight to nine residues generated from cytosolic proteins. we find that ctl recognize, in vitro and in vivo, cells synthesizing a 10-residue peptide consisting of an initiating methionine followed by nine residues corresponding to a naturally processed determinant from influenza virus nucleoprotein (np) (residues 147-155). addition of two cooh-terminal residues corresponding to np r ... | 1992 | 1732413 |
| sequence changes in the live attenuated, cold-adapted variants of influenza a/leningrad/134/57 (h2n2) virus. | nucleotide sequences were determined for the rna segments coding for proteins other than the hemagglutinin and neuraminidase of the a/leningrad/134/57 (h2n2) wild-type (a/len/wt) virus and its two cold-adapted (ca) and attenuated variants, a/leningrad/134/17/57 (a/len/17/ca) and a/leningrad/134/47/57 (a/len/47/ca) that are used in the u.s.s.r. in the preparation of reassortant live attenuated vaccines. ten nucleotide differences were detected between the sequences of the a/len/wt and a/len/17/ca ... | 1992 | 1733114 |
| a single amino acid deletion at the amino terminus of influenza virus hemagglutinin causes malfolding and blocks exocytosis of the molecule in mammalian cells. | i am investigating the role of protein folding in the transport of influenza virus hemagglutinin (ha), a membrane-bound protein, along the exocytotic pathway. from a previous work (gething, m.-j., mccammon, k., and sambrook, j. (1986) cell 46, 939-950), it has been shown that a subset of alterations of the cooh-terminal sequences of the ha molecule inhibit folding and impede its transport to the cell surface. current studies establish that the integrity of the nh2-terminal sequences of the ha is ... | 1992 | 1733923 |
| further studies with short duration ribavirin aerosol for the treatment of influenza virus infection in mice and respiratory syncytial virus infection in cotton rats. | ribavirin aerosol administration has been shown to be effective in the treatment of respiratory syncytial virus (rsv) infections in infants and in influenza a and b virus infections in young adults. long treatment schedules and potential for environmental contamination have stimulated the search for alternative dosing schedules. thus, we attempted to determine the length of time of ribavirin aerosol necessary for effective treatment of influenza and rsv. in rsv-infected cotton rats, aerosolizati ... | 1992 | 1736809 |
| structure and assembly of hemagglutinin mutants of fowl plague virus with impaired surface transport. | five temperature-sensitive mutants of influenza virus a/fpv/rostock/34 (h7n1), ts206, ts293, ts478, ts482, and ts651, displaying correct hemagglutinin (ha) insertion into the apical plasma membrane of mdck cells at the permissive temperature but defective transport to the cell surface at the restrictive temperature, have been investigated. nucleotide sequence analysis of the ha gene of the mutants and their revertants demonstrated that with each mutant a single amino acid change is responsible f ... | 1992 | 1738202 |
| outbreak of influenza a in a nursing home--new york, december 1991-january 1992. | during december 1991 and january 1992, an outbreak of influenza a occurred among residents of a nursing home in new york. from mid-october through mid-november 1991, influenza vaccine was administered to 295 (88%) of the 337 residents of the nursing home. the residents shared common dining and recreational areas; the mean age of residents was 83 years (range: 51-103 years); 256 (76%) were female. the prevalence of underlying illness in vaccinated and unvaccinated patients was not determined. | 1992 | 1738358 |
| amantadine-resistant influenza a in a nursing facility. | rapid index case treatment and amantadine prophylaxis were implemented in two nursing homes exposed to influenza a. facility a had no isolation of cases, and 18 of 22 cases occurred after amantadine hydrochloride therapy was initiated. three patients exhibited amantadine-resistant virus. facility b had day 1 isolation of the index case. a facility-wide outbreak did not occur. the experience of these facilities suggests that concurrent amantadine treatment and prophylaxis without adequate case is ... | 1992 | 1739371 |
| the 2.2 a resolution crystal structure of influenza b neuraminidase and its complex with sialic acid. | influenza virus neuraminidase catalyses the cleavage of terminal sialic acid, the viral receptor, from carbohydrate chains on glycoproteins and glycolipids. we present the crystal structure of the enzymatically active head of influenza b virus neuraminidase from the strain b/beijing/1/87. the native structure has been refined to a crystallographic r-factor of 14.8% at 2.2 a resolution and its complex with sialic acid refined at 2.8 a resolution. the overall fold of the molecule is very similar t ... | 1992 | 1740114 |
| reduced infectivity of cold-adapted influenza a h1n1 viruses in the elderly: correlation with serum and local antibodies. | to compare young and elderly adults in terms of their immune responses and rates of infection following intranasal vaccination with a live attenuated influenza virus. | 1992 | 1740601 |
| fine specificity of cytotoxic t lymphocytes primed in vivo either with virus or synthetic lipopeptide vaccine or primed in vitro with peptide. | standard synthetic peptide preparations contain numerous peptidic byproducts in small amounts, which may be efficiently recognized by cytotoxic t lymphocytes (ctl). recognition patterns of such peptide mixtures by ctl may serve as a kind of fingerprint for ctl fine specificity. three types of h-2db-restricted ctl were compared in this way. ctl primed in vivo either with a/pr/8/34 influenza virus or with a synthetic lipopeptide vaccine prepared from influenza nucleoprotein (np) peptide 365-380 sh ... | 1991 | 1744592 |
| [atypical pathogen spectrum in community-acquired infections of the lower respiratory tract in childhood]. | over a period of 14 months, we obtained nasal and throat swabs for virological examinations from patients, admitted to hospital with suspected pneumonia. fifty-five cases of perihilar bronchitis and 103 cases of pneumonia were diagnosed based on radiological criteria. in 36% (n = 57) of the children, a pathogen could be determined by antigen elisa. we found the following spectrum: respiratory syncytial virus: 42%; influenza a: 8%; influenza b: 10%; parainfluenza 1: 3%; parainfluenza 2: 10%; para ... | 1991 | 1745250 |
| [the biological effects in animals in relation to the accident at the chernobyl atomic electric power station. 10. cooperative immune reactions in different generations of mice]. | the immune status of mice has been assessed by the whole complex of data. the permanent action of low-level radiation has been shown to suppress considerably the rate of reactions of the delayed-type hypersensitivity and "graft versus host" disease, as well as nk and specific cytolytic t-lymphocyte activity. the dynamics of accumulation and the levels of antiviral antibodies in the serum, lung and trachea extracts are virtually invariable. the resistance of experimental animals to influenza is l ... | 1991 | 1745757 |
| [immunomorphological changes in the mouse brain after intracerebral administration of a neurotropic strain of influenza virus]. | the work dealt with intracerebral inoculation of 150 mice with neurotropic strain of influenza virus a/wsn/33. virological and immunohistochemical study of virus localization in the mice brain was carried out. it was shown that virus reproduction in ependymal lining cells and plexus choroideus epithelium is followed by destruction of cells and uptake of disintegration products by macrophages. since the influenza infection is followed by a large number of macrophages involved in gene expression o ... | 1991 | 1747476 |
| influenza virus activity in papua new guinea. | influenza viruses remain a major cause of respiratory disease in both developed and developing countries. a great deal of information concerning the structure, pathology and modes of transmission of these viruses has been accumulated, but no means of successfully combating them have, as yet, been devised. the most appropriate strategy for limiting the effects of influenza is to monitor the emergence and spread of new strains carefully and warn the public and at-risk groups of impending epidemics ... | 1991 | 1750264 |
| [suppression of translation in vitro of the mrna of the m1 protein of influenza virus using antisense oligonucleotides]. | effect of antisense oligonucleotides on the in vitro translation of the influenza virus m1 protein mrna was investigated. the most efficient arrest of mrna translation was achieved by simultaneous action of two or three oligonucleotides (14-16-mers) complementary to the juxtaposed sequences in the 5'-terminus of the molecule around and upstream of the initiation codon. | 1991 | 1753959 |
| high dose-short duration ribavirin aerosol treatment--a review. | a high-dose, short-duration treatment with ribavirin aerosol consisting of a three-fold increase in concentration of drug (60 mg versus 20 mg of ribavirin per ml in the liquid reservoir of the generator administered for about one-third the time of the standard treatment) was as effective as the standard dosage in the treatment of experimental influenza a and b infections in mice and in the treatment of experimental respiratory syncytial virus infection in cotton rats. despite some minor pulmonar ... | 1991 | 1756300 |
| studies on the regulation of influenza virus rna replication: a differential inhibition of the synthesis of vrna segments in shift-up experiments with ts mutants. | the regulation of influenza virus vrna synthesis in the course of the reproduction cycle was studied with the use of a series of ts mutants in shift-up experiments. the synthesis of vrna segments was registered by means of polyacrylamide gel electrophoresis of nucleocapsid-associated rna isolated from the infected cells labelled with [3h]uridine after the shift-up to a semi-permissive temperature. each mutant exhibited a specific differential pattern of vrna synthesis inhibition after the shift- ... | 1991 | 1759912 |
| positioning of a peptide in the cleft of hla-a2 by complementing amino acid changes. | several mutant hla-a2 molecules have been constructed and expressed in the mutant human b-cell line c1r, which lacks hla-a and hla-b antigens, and examined for presentation of a previously defined peptide epitope derived from the influenza matrix protein to appropriate human cytotoxic t-lymphocyte lines. when leucine residue 66 in this matrix peptide containing residues 57-68 (matrix peptide 57-68) was replaced by arginine, the resulting matrix peptide 57-68 r66 was not presented to hla-a2, but ... | 1991 | 1763045 |
| amantadine selection of a mutant influenza virus containing an acid-stable hemagglutinin glycoprotein: evidence for virus-specific regulation of the ph of glycoprotein transport vesicles. | mutants of influenza rostock virus (h7n1 subtype) were selected for resistance to amantadine hydrochloride at concentrations of the antiviral drug known to affect the function of the virus m2 transmembrane protein. sequence analysis revealed that three mutants had no changes in m2 but contained a lysine to isoleucine substitution in the hemagglutinin (ha) membrane glycoprotein at position 58 of ha2. the mutant viruses were found to fuse membranes at a ph value 0.7 lower than wild type and to exh ... | 1991 | 1763066 |
| a baculovirus dual expression vector derived from the autographa californica nuclear polyhedrosis virus polyhedrin and p10 promoters: co-expression of two influenza virus genes in insect cells. | a baculovirus transfer vector, pacuw3, was developed to facilitate the insertion of two influenza virus genes, those encoding the haemagglutinin (ha) and neuraminidase (na) membrane glycoproteins, into the autographa californica nuclear polyhedrosis virus genome in a single cotransfection experiment. the na gene was inserted in place of the polyhedrin coding sequences under the control of the polyhedrin promoter, whereas the ha gene was placed under the control of a copy of the p10 promoter at a ... | 1991 | 1765769 |
| characterisation of an ionisable group involved in binding and catalysis by sialidase from influenza virus. | the effect of ph on the kinetics of sialidase purified from influenza virus (a/tokyo/3/67, h2n2) was investigated. a pk of 9.0 for inhibition of the enzyme by three competitive inhibitors, due to an ionisable group in the active site, was observed. a similar pk was observed for v/km for the fluorogenic substrate 2-(4-methylumbelliferyl)-n-acetyl-alpha-d-neuraminic acid. however, the shape of the v/km profile indicates that this substrate is sticky. solvent perturbation experiments indicated that ... | 1991 | 1768256 |
| purification and properties of cloned salmonella typhimurium lt2 sialidase with virus-typical kinetic preference for sialyl alpha 2----3 linkages. | subclones containing the salmonella typhimurium lt2 sialidase gene, nanh, were expressed in escherichia coli from multicopy derivatives of pbr329. the cloned sialidase structural gene directed overproduction of sialidase polypeptide which was detected as the major soluble protein species in cell-free extracts. overproduced enzyme was purified to near electrophoretic homogeneity after 65-fold enrichment using conventional preparative techniques. unlike all previously investigated sialidases, s. t ... | 1991 | 1769974 |
| gm allotypes influence the production of igg3 but the effect is age-dependent. | serum concentrations of igg3 were found to be higher in gm-f-positive (= b-positive) than in f-negative individuals except in young children. young children aged 3-4 months had a mean concentration of 0.24 g/l of igg3 regardless of allotype. the concentration gradually rose with age in f-positive individuals to a geometric mean of 0.56 g/l in adults but it remained essentially unchanged in f-negative people. a corresponding allotype effect was seen in influenza-specific antibody responses. while ... | 1991 | 1774195 |
| detergent enhances binding of a secreted hla-a2 molecule to solid phase peptides. | we have constructed a secreted analogue (sa2) of the human class i molecule hla-a2. sa2 was affinity purified both in the presence and absence of detergent and the effects of detergent on the magnitude and specificity of a2 binding to solid phase peptides tested. sa2 purified in the presence of detergent and detergent-solubilized a2 are shown to function comparably in the binding of the synthetic peptide m.y + 57-68, a known t-cell epitope derived from the influenza a matrix protein. the molecul ... | 1991 | 1774199 |
| rapid detection of type a influenza viruses with monoclonal antibodies to the m protein (m1) by enzyme-linked immunosorbent assay and time-resolved fluoroimmunoassay. | monoclonal antibodies (mabs) to the m protein (m1) were used in the development of direct detection systems for type a influenza viruses in clinical specimens. optimal detection by an enzyme-linked immunosorbent assay was achieved when mabs were used as capture antibodies and rabbit polyclonal antibodies were used as sandwich antibodies. detection by the enzyme-linked immunosorbent assay required amplification of the virus. direct detection in clinical specimens (nasopharyngeal aspirates) was ac ... | 1991 | 1774253 |
| defective insertion of haemagglutinin as a cause of abortivity of influenza a viruses in hela 229 cells. | a number of experimental data demonstrate that certain mammalian cells are unable to replicate influenza viruses type a. in these cellular hosts the viruses can efficiently perform their biological as well as biochemical activities but the production of mature viral particles is greatly restricted. here we report a study of abortiveness of human and avian type a influenza viruses in hela 229 cells in which the final stages of maturation of viral particles seem to be affected. we show that the in ... | 1991 | 1775092 |
| [oxidative phosphorylation in liver mitochondria in toxic form of experimental form of influenza]. | the effect of free radical processes on the oxidation-phosphorylation activity in the liver of cba-mice has been studied, using a model of toxic form viral infection. the epr-spectroscopic and electrochemical methods applied in the study of animals infected with pathogenic form of the influenza virus made it possible to reveal a decrease in the activity of the respiratory chain in mitochondria. this seems likely to be due to accumulation of endogenic nitric oxide in the liver tissue. | 1991 | 1777629 |
| the effect of restraint stress on the kinetics, magnitude, and isotype of the humoral immune response to influenza virus infection. | the stress of physical restraint has been shown to modulate the cellular immune response during a viral infection. we have studied the effects of stress on the humoral immune response during infection by influenza virus. restraint stress altered the kinetics of the antibody response; seroconversion in the igg and iga isotypes was delayed in virus-infected c57bl/6 mice subjected to repeated cycles of physical restraint. however, the magnitude and isotype of the mature antibody response were unaff ... | 1991 | 1777731 |
| [the use of the soviet detergents dezintegron-o and dezintegron-b for the solubilization of influenza virus glycoproteins]. | native detergents, desintegron-o-and desintegron-b, solubilize hemagglutinins of the influenza virus as intensively, as foreign drugs (mulgophen, zwittergent and sodium sarcozyl) do. this permits recommending desintegrons for quantitative determination of hemagglutinin of the influenza virus in virus-containing materials by means of the reaction of single radial immunodiffusion. desintegron-o and desintegron-b permit extracting enzymatically active neuraminidase from influenza a viruses with 44. ... | 1991 | 1779909 |
| a quantitative measurement of the effect of avian influenza virus on the ability of turkeys to eliminate pasteurella multocida from the respiratory tract. | the effect of avian influenza virus (aiv) infection on the ability of turkeys to eliminate pasteurella multocida from the respiratory tract was evaluated. four-week-old turkeys were experimentally infected with an apathogenic aiv subtype (h5n2) by the oculonasal route and subsequently superinfected with p multocida (urbach strain) by the intranasal route three days after infection with aiv. quantitative clearance of p multocida from the trachea and lung was determined using a pour plate techniqu ... | 1991 | 1780577 |
| influenza in the world. 1 october 1990-30 september 1991. | | 1991 | 1782122 |
| a new influenza surveillance system in france: the ile-de-france "grog". 2. validity of indicators (1984-1989). | the evaluation of the validity of the grog's indicators is based on the first five years of activity, four of which being epidemic ones. a virological criterion for identifying epidemics is used as the gold standard. for each non-specific indicator, the ratio of epidemic weeks to non-epidemic weeks is outlined. therefore we can define four epidemic situations in relation with the strains circulating and the non-specific indicators. influenza a epidemics, which are known as a mortality problem ca ... | 1991 | 1783052 |
| comparison of rapid immunofluorescence assay to cell culture isolation for the detection of influenza a and b viruses in nasopharyngeal secretions from infants and children. | in the hospital setting it is often critical to isolate patients appropriately in order to prevent nosocomial infection. this is especially true with respiratory infection in infants and young children. at the present time a rapid immunofluorescence assay (ifa) for respiratory syncytial and parainfluenza viruses is routinely carried out in our laboratory. during january and february of 1990 we used monoclonal antibodies specific for influenza a and b viruses (baxter-bartels, bellevue, wa) in thi ... | 1991 | 1783676 |
| [the interrelations of the human and avian influenza viruses a(h2) determined by the mathematical processing of data on the antigenic structure of their hemagglutinin]. | mathematical methods were used to analyse the data on the antigenic specificity of h2 subtype hemagglutinin of human and avian influenza a viruses. this approach allowed the evaluation of possible evolutional relationships in this little-studied group of viruses. influenza a (h2) viruses isolated from birds in the usa were found to represent a sufficiently isolated group, whereas european avian strains (a/duck/germany/1215/73, a/pintail duck/primor'e/695/76, a/duck/marseilles/46/76) were close t ... | 1991 | 1785179 |
| [the use of the lectin test for detecting antineuraminidase antibodies in the sera of vaccinated subjects]. | the lectin test (a microvariant) was used to study the immunogenicity of live attenuated and inactivated virion divaccines of influenza a (h1n1 + h3n2) and influenza b vaccines in children 3 to 15 years of age. a good correlation was found between the general level of seroconversion of antineuraminidase and antihemagglutinin antibodies in the sera examined. this method is simple and may be useful for titration of large numbers of sera in studies on the immunogenicity of influenza vaccines or pec ... | 1991 | 1785180 |
| [the inoculation properties of live recombinant influenza vaccine types a and b used separately and jointly in children 3 to 14]. | the reactogenicity and immunizing activity of vaccine influenza virus a (h1n1) and b strains used as mono- and bi-preparations in children of 3 to 14 years was studied. no increased reactogenicity after the use of bivaccine was observed in the children. febrile reactions as well as 9 other clinical symptoms which could indicate the reactogenicity of the vaccines were identical for mono- and bivaccine and corresponded to the requirements of the technical documents for the vaccine. the optimal con ... | 1991 | 1785181 |
| [the formation of an immune response in volunteers inoculated with a live recombinant influenza vaccine]. | the capacity of a live influenza vaccine (liv) to stimulate cytotoxic cells (adcmc and nk) was studied in 49 volunteers and 56 patients with influenza. experimental batches of liv from influenza a and b viruses prepared by genetic recombination on the basis of cold-adapted attenuation donors were used. type a and b liv were shown to stimulate the cytotoxic cell-mediated and humoral immunity; the intensity of immune response, however, depended on the molecular genetic characteristics of the vacci ... | 1991 | 1785182 |
| [the effective use of superoxide dismutase from human erythrocytes in the late stages of experimental influenza infection]. | the role of reactive oxygen species (ros) in the pathogenesis of influenza infection was studied. bronchoalveolar lavage and serum of influenza-infected mice were shown to produce ros following the addition of phorbole ether-pma. the generation of ros was the maximum in 5-6 days after virus inoculation which coincided with the beginning of animal deaths. the main form of ros was hypochloride generated by neutrophil meyloperoxidase. treatment of mice with superoxide dismutase (sod) in the late pe ... | 1991 | 1785183 |
| automated monitoring system for determining embryo movement and death times following virus infection. | design and performance information is presented on an automated embryo-monitoring system for intact eggs. the computer-based system has been used successfully for several months to characterize viral pathogenicity in embryonated eggs. features include electronic sensing of embryo movement, automatic quantification of the amount of movement, and automatic recording of the results on electronic media. the system does not require that eggs be removed from the incubator or that the incubator be open ... | 1991 | 1786014 |
| influenza immunization recommendations for delaware. | | 1991 | 1786842 |
| [molecular mechanisms of selecting influenza virus strains by signs of drug resistance]. | | 1991 | 1794277 |
| [influenza--1989]. | | 1991 | 1796162 |
| [the pathomorphological changes in the organs and tissues of mice with congenital pathology induced by the inactivated influenza virus]. | the structural and functional changes in organs and tissues of 30 young mice born from mothers treated intravenously with irradiation-inactivated influenza virus were studied. a detailed morphological analysis showed that a single inoculation of pregnant females with inactivated influenza virus resulted in the progeny in morphological lesions in organs and tissues typical of slow influenza infection. | 1991 | 1796582 |
| [an experimental study of adp-ribosylation inhibitors as anti-influenza agents]. | tri-substituted benzamide derivatives are described as a new class of antiviral drugs. three compounds (3, n-acetylaminobenzamide, 3, n-butyrylaminobenzamide, and 3-methoxybenzamide) protected mice inoculated with influenza type a virus. 3, n-acetylaminobenzamide was found to be most active. it is suggested that the antiviral effect may be due to the specific inhibitory action of these compounds on nad(+)-dependent adp-ribosylation. | 1991 | 1796583 |
| comparison between three rapid methods for direct diagnosis of influenza and the conventional isolation procedure. | besides the rapid diagnostic tests based on influenza a and b antigens nucleoproteins detection, which are routinely used, the isolation of influenza strains is still required to obtain recent variant isolates for full antigenic characterization, in order to up-date the influenza vaccine composition. to increase the rapidity and the efficacy of the virus growth, we implemented a culture test in 24-well plates by centrifugation of samples on to llcmk2 cells in the presence of trypsin. this test w ... | 1991 | 1797040 |
| influenza: relation of mortality to morbidity parameters--netherlands, 1970-1989. | the purpose of this study is to investigate the relationship between the number of influenza-like illness (ili), weekly registered by the general practitioners (sentinel stations), and the monthly overall influenza mortality in people over 60 years of age, provided by the dutch statistical bureau during the period july 1970 to june 1989. the quantitative impact of influenza-morbidity is expressed by three summary parameters, calculated from the 52 (53) weekly ili-figures per season-year, (i) the ... | 1991 | 1800412 |
| [massive hemorrhages into the cerebellum in influenza occurring as a space-occupying process]. | | 1991 | 1803731 |
| [a comparative study of the inoculation properties of live recombinant and inactivated influenza vaccines made from strain a/philippines/2/82 (h3n2) in 8- to 15-year-old children]. | this study was carried out to compare reactogenicity, immunogenicity, and efficacy of live attenuated and inactivated influenza vaccines prepared from influenza a/philippines/2/82-like virus strains. schoolchildren of a boarding school of moscow were randomly divided into three groups: (1) vaccinated with a live attenuated vaccine, (2) vaccinated with inactivated influenza vaccine, and (3) given placebo. both vaccines were well tolerated by the children, with practically no severe general or loc ... | 1991 | 1803766 |
| [a comparative study of the protective properties of live recombinant and inactivated influenza vaccines made from strain a/philippines/2/82 (h3n2) in 8- to 15-year-old children]. | a limited controlled comparative study for the evaluation of the epidemiological efficacy of live recombinant and inactivated virion vaccines from a/philippines/2/82-like strains of influenza a (h3n2) virus was carried out in schoolchildren of 8 to 15 years of age. during the influenza epidemic of 1987-1988 caused by influenza a/sichuan/2/87 (h3n2)-like strains and by influenza b virus in 8.2-17% of cases, a statistically significant efficacy index for live influenza vaccine was 1.8 for the labo ... | 1991 | 1803767 |
| [the antigenic and biological properties of influenza a (h1n1) viruses isolated in the ussr and the czechoslovak federal republic in 1988-1989]. | a comparative study of influenza a (h1n1) virus strains isolated in one epidemic season (1988-1989) in neighbouring countries was carried out. using polyclonal and monoclonal antibodies, some of the isolates were shown to have different antigenic and biological properties which probably determined the different intensity of the epidemic situation in the ussr and czsfr in 1988-1989. | 1991 | 1803768 |
| [the effect of detergents on the physicochemical and immunochemical properties of the isolated m1 protein of the influenza virus]. | the degree of solubility of influenza virus protein m1 preparations isolated from virions by acid chloroform-methanol extraction was studied under the effect of a wide spectrum of detergents of different origin. the same detergents were used for solution of a lipid comprising a part of artificially formed liposomes. only some of the detergents used (sodium dodecyl sulfate, sds, triton x-100, and disintegron-b) were shown to be optimal for solution of both influenza virus protein m1 and lipid. th ... | 1991 | 1803769 |
| [the effect of different factors on the reproduction of influenza viruses and reassortants in cell cultures]. | the influence of the maintenance medium, polyethylene glycol (peg), deae-dextran, and low temperature on reproduction of influenza a, b, and c viruses and their reassortants in diploid and continuous cell cultures was determined. lowering of ph in the maintenance medium to 6.5 was found to decrease reproduction of influenza a (h1n1) and a (h3n2) viruses and increase that of influenza b viruses. treatment of cells with peg solution increased the yield of influenza b and c but not a viruses. howev ... | 1991 | 1803770 |
| [interepidemic influenza in bulgaria based on laboratory research data]. | during the interepidemic periods of 34 years (1955-1988) the national influenza centre of bulgaria with the aid of 11 supporting stations investigated a total of 27240 nasopharyngeal washings and 42530 paired sera of patients with acute respiratory diseases. eighty strains of subtype a (h1n1) influenza virus, 60 strains of subtype a (h2n2), 148 strains of subtype a (h3n2), 3 strains of subtype a (heg2, neg2), 2 strains of subtype a (hsw1n1), 14 strains of type b, and 6 strains of type c were iso ... | 1991 | 1803771 |
| haemagglutination-inhibiting antibodies against influenza a and b in human sera collected from five ecological zones in nigeria. | the prevalence of antibodies to the haemagglutinins of two influenza a subtype, h1n1 and h3n2 and influenza b in sera collected from 1986 to 1988 from persons of different ages and from 10 locations in 5 ecological zones of nigeria was determined. the levels of influenza antibodies in the sera varies with age and ecological zones of the country. a total of 1,022 sera were tested, of which 732 (71.6%) were positive for influenza antibodies. the prevalence of antibodies at titre 1:10 varied betwee ... | 1991 | 1804870 |
| immunoprophylaxis of otitis media. | prospects for an effective otitis media vaccine are bolstered by a number of encouraging observations. results of pneumococcal polysaccharide vaccine trials beginning in 1975, the enormously enhanced immunogenicity of protein-hib polysaccharide coupled vaccines in infants, and the apparent effectiveness of a protein-pcp coupled vaccine in experimental otitis media suggest that a pneumococcal vaccine targeted to prevent invasive and middle ear infections is not too distant. the identification of ... | 1991 | 1805562 |
| interferons in the treatment of malignancies. | interferons alpha, beta and gamma (ifn) were initially identified as soluble factors able to inhibit infection of chick chorioallantoic membranes by influenza a virus. although the mechanism(s) of action of ifns are unclear, these molecules express their biologic properties after binding to specific high-affinity cell membrane receptors. to dates several clinical studies have challenged the therapeutic benefits of using ifns in the treatment of solid tumours and haematologic malignancies. the re ... | 1991 | 1810444 |
| [the mechanism of the receptor binding of influenza viruses by somatic tissue cells]. | | 1991 | 1810492 |
| [the anti-idiotypic response to the experimental administration of the inactivated or live influenza virus]. | the injection of inactivated and live influenza virus into rabbits induces the formation of anti-idiotypic antibodies, appearing after anti-influenza hemagglutinins, in the blood. the presence of immune complexes antibody--anti-idiotypic antibody in the blood of the animals has been established. the booster immunization of the animals with influenza virus antigens produces a rise in the levels of both idiotypic and anti-idiotypic antibodies. the injection of autologous anti-idiotypic globulin in ... | 1991 | 1811391 |
| [the evolutionary characteristics of an influenza epidemic in a large urban center (b.) of romania between 1988 and 1990]. | the report presents the peculiar characteristics of influenza epidemics in a big urban centre (b.) of romania, between 1988 and 1990, surveyed by clinical, epidemiological and laboratory methods. among the peculiarities of the epidemics: the low rate of endemic morbidity, the seasonal and preseasonal peaks, the very high implication of infantile population in influenza a(h3n2), a(h1n1) and b virus circulation, as well as the high level of mass specific humoral protection against these viruses. e ... | 1991 | 1814431 |
| isolation and characterization of egg yolk antibodies igy from hens immunized with different influenza virus strains. | a comparison of two precipitation methods of igy from normal hen eggs was made. for method i the precipitation agent is represented by peg 6000, and for method ii by organic solvents. the comparative study of some parameters (protein concentration, ovalbumin content, presence of non-specific inhibitors, paa-gel electrophoresis) shows that method i is more efficient and more convenient than method ii. using this method, we isolated and characterized igy preparations from hens immunized with circu ... | 1991 | 1821163 |
| [usefulness of elisa and radial immunodiffusion tests for evaluation of the degree of purification of influenza diagnostic and vaccine preparations]. | it is necessary to use new diagnostic tests for careful and rapid evaluation of a degree of purification and immunogenicity of vaccine anti-influenza preparations. in this study in order to obtain this purpose a radial immunodiffusion++ test and immunoenzymatic test (elisa) were used recommended by who radial immunodiffusion++ test enable to determine a level of haemagglutinin of particular types and subtypes of influenza virus in polyvalent preparations. however, this test is time consuming the ... | 1991 | 1823376 |
| nosocomial influenza in a general hospital for indigent patients. | surveillance of influenza virus infections was maintained on the medical and pediatric wards of a general hospital serving indigent patients of harris county, texas during the winter of 1987-88. influenza a/sichuan/2/87(h3n2) was the predominant virus during the community epidemic. influenza a(h3n2) virus was isolated from six of 17 adult patients (35%) suspected to have nosocomial infections; two of these patients died of fulminating pneumonia. another patient, admitted with alcoholism and hema ... | 1991 | 1824284 |
| inhibition of multicycle influenza virus replication by hybrid antibody-directed cytotoxic t lymphocyte lysis. | bifunctional antibodies with specificity for the tcr/cd3 complex as well as to a target cell-surface ag can redirect ctl to lyse the target cell. we have produced a hybrid hybridoma, hha6, which secretes bifunctional antibodies capable of redirecting ctl to lyse influenza virus-infected target cells. when added along with ctl to virus-infected cells, these antibodies very efficiently inhibit multicycle virus replication. because hybrid hybridomas reassort h and l chains randomly we attempted to ... | 1991 | 1824592 |
| influenza a virus in vitro transcription: roles of ns1 and np proteins in regulating rna synthesis. | to study the mechanisms by which the influenza a virus rna-dependent rna polymerase switches from transcription to replication we have devised a riboprobe protection technique with which we analyzed the 3' end sequence of (+)-strand rna products of an in vitro transcription reaction containing purified virion-rnp complexes in the presence and the absence of the putative regulatory proteins np and ns1. we found that the addition of these proteins did not result in the synthesis of full-length (+) ... | 1991 | 1824905 |
| regulation of the extent of splicing of influenza virus ns1 mrna: role of the rates of splicing and of the nucleocytoplasmic transport of ns1 mrna. | influenza virus ns1 mrna is spliced by host nuclear enzymes to form ns2 mrna, and this splicing is regulated in infected cells such that the steady-state amount of spliced ns2 mrna is only about 10% of that of unspliced ns1 mrna. this regulation would be expected to result from a suppression in the rate of splicing coupled with the efficient transport of unspliced ns1 mrna from the nucleus. to determine whether the rate of splicing of ns1 mrna was controlled by trans factors in influenza virus-i ... | 1991 | 1824958 |
| ns2 protein of influenza virus is found in purified virus and phosphorylated in infected cells. | purified viral preparations of influenza a virus were examined for the presence of ns2 protein hitherto considered as a viral nonstructural protein that is present only in infected cells. analysis of purified virus by radioimmunoprecipitation with monospecific antisera to ns2 revealed its presence in the virus particle suggesting that it is a viral structural protein. ns2 protein was also shown to be phosphorylated in infected cells in this study. this brings the number of influenza virus phosph ... | 1991 | 1825776 |
| cell surface transport, oligomerization, and endocytosis of chimeric type ii glycoproteins: role of cytoplasmic and anchor domains. | we investigated the role of cytoplasmic and anchor domains of type ii glycoproteins in intracellular transport, oligomerization, and endocytosis by expressing the wild-type and chimeric genes in mammalian cells. chimeric genes were constructed by exchanging the dna segments that encode the cytoplasmic and anchor domains between the human influenza virus (a/wsn/33) neuraminidase (na) and transferrin receptor (tr). the chimeric proteins in which domains were exchanged precisely were productively t ... | 1991 | 1826760 |
| assessing pathogenicity potential of waterfowl-origin type a influenza viruses in chickens. | intravenous pathogenicity index (ivpi) tests on 29 wild duck-origin type a influenza viruses, two turkey-origin type a influenza viruses, and one chicken-origin type a influenza virus resulted in indices ranging from 0.0 to 0.49. most of the wild duck-origin viruses and the two turkey-origin viruses had indices of 0.0, indicating they are not pathogenic. six of the duck-origin viruses had indices ranging from 0.25 to 0.49, and the ivpi for a/chicken/alabama/75 (h4n8) was 0.49, indicating they ha ... | 1991 | 1827578 |
| amantadine resistance among hemagglutinin subtype 5 strains of avian influenza virus. | several avian influenza virus strains of hemagglutinin subtype 5 were assayed for sensitivity to the antiviral drug amantadine. most strains exhibited little sensitivity to the drug as measured by plaque reduction. the a/chicken/scotland/59 (cs59), however, was highly sensitive, making it easily distinguishable from the other h5 strains. drug sensitivity of the viruses was also assayed in chicken embryos. the in ovo patterns of amantadine sensitivity differed from those detected in cell culture. ... | 1991 | 1827579 |
| intragenic suppression of a deletion mutation of the nonstructural gene of an influenza a virus. | the influenza a/alaska/77 (h3n2) virus mutant 143-1 is temperature sensitive (ts) due to a spontaneous in-frame 36-nucleotide deletion in the nonstructural (ns) gene segment, which leads to a 12-amino-acid deletion in the ns1 protein. in addition, it has a small-plaque phenotype on mdck cell monolayers. however, phenotypically revertant (i.e., ts+) viruses were isolated readily following replication of the 143-1 virus both in vitro and in vivo. in order to determine the genetic mechanism by whic ... | 1991 | 1830112 |
| phylogenetic relationship of the nonstructural (ns) genes of influenza a viruses. | phylogenetic trees were constructed using 38 sequences of the a group and 10 sequences of the b group of the ns gene of influenza a viruses. within the a group we found avian as well as mammalian influenza a viruses, while within the b group exclusively avian strains were found. the avian and human ns genes of the a group were derived from a common ancestor existing at about 1912. at 13 positions of the amino acid sequences of the ns1 protein two subtypes of the a group can be differentiated, a ... | 1991 | 1830182 |
| difference in receptor specificity among influenza a viruses from different species of animals. | | 1991 | 1830813 |
| microbial induction of co-stimulatory activity for cd4 t-cell growth. | the activation of naive cd4 t cells by antigen is a critical step in the initiation of an immune response; it requires both ligation of the t-cell receptor (tcr) and the delivery of co-stimulatory factors by accessory cells. we have examined the role of syngeneic accessory cells in the response of purified normal cd4 t cells to anti-cd3 antibody as ligand. we show that the ability to deliver co-stimulatory signals is inducible in b cells by microbial products such as bacterial lipopolysaccharide ... | 1991 | 1831651 |
| differential sensitivity of cd8+ suppressor and cytotoxic t lymphocyte activity to bacterial monophosphoryl lipid a. | treatment with a preparation of monophosphoryl lipid a, known to be capable of abolishing the expression of cd8+ suppressor t cell activity generated during the antibody response to type iii pneumococcal polysaccharide (sss-iii), was found to have no adverse effect upon either induction or expression of cd8+ cytotoxic t lymphocyte activity specific for influenza a virus antigens. this suggests that suppressor t cells and cytotoxic t lymphocytes represent functionally distinct subsets of cd8+ t c ... | 1991 | 1831794 |
| activation status of the cd4-8- gamma delta-t cells recovered from mice with influenza pneumonia. | the role that gamma delta-t lymphocytes play in virus infections is yet to be defined. the tcr-gamma delta + cell population found late in the course of influenza pneumonia has been analyzed for ligand-dependent lytic function. these gamma delta-t cells are not constitutively cytotoxic when recovered directly from the site of virus-induced damage in the respiratory tract, although the tcr-alpha beta + population that is present concurrently contains such lytic effectors. both sets of lymphocytes ... | 1991 | 1833449 |
| extensive conservation of alpha and beta chains of the human t-cell antigen receptor recognizing hla-a2 and influenza a matrix peptide. | the major histocompatibility complex class i molecule hla-a2.1 presents the influenza a virus matrix peptide 57-68 to cytotoxic t lymphocytes in all individuals with this common hla type and is among the most thoroughly studied immune responses in humans. we have studied the t-cell receptor (tcr) heterogeneity of t cells specific for hla-a2 and influenza a matrix peptide using the polymerase chain reaction. the usage of v alpha and v beta sequences seen on these t cells is remarkably conserved a ... | 1991 | 1833769 |
| an influenza virus containing nine different rna segments. | the packaging mechanism of segmented rna viruses has not been well studied. specifically, it has not been clear whether influenza a viruses package only eight rna segments or whether virus particles contain more than eight segments. using a newly developed ribonucleoprotein (rnp) transfection method, we engineered an influenza virus which must contain nine different rna segments rather than the usual eight in order to survive under the experimental growth conditions. this result is compatible wi ... | 1991 | 1833874 |
| evaluation of different methods of inactivation of newcastle disease virus and avian influenza virus in egg fluids and serum. | viruses conveyed in shipments of eggs, viral diagnostic reagents, or avian serum samples are a potential hazard for susceptible poultry. different methods of treatment of those materials to eliminate the hazard of virulent and avirulent strains of newcastle disease virus (ndv) or avian influenza virus (aiv) were evaluated. the ndv strains tested were more thermostable than the aiv strains. the results suggest that standard pasteurization methods would not reliably inactivate the concentrations o ... | 1991 | 1835374 |
| synthesis of the ns 2 nonstructural protein messenger rna of influenza a viruses occurs in the absence of viral protein synthesis. | the ns 2 messenger rna (mrna) of several influenza a viruses was shown to be synthesized in primary transcription. analysis of in vitro translation products of mrnas from infected mdck cells treated with cycloheximide indicated that the ns 2 mrna in addition to the ns 1 mrna was synthesized with pr/8, udorn, and aichi viruses. the findings indicated that the ns 1 mrna of these viruses was able to be spliced into the ns 2 mrna as a primary transcript without viral protein synthesis, although the ... | 1991 | 1835573 |
| heat-shock proteins and the gamma delta t cell response in virus infections: implications for autoimmunity. | | 1991 | 1837959 |
| [the antigenic characteristics of influenza a viral strains circulating synchronously in 2 separated areas (the czsfr--saint petersburg)]. | a comparative study of the antigenic characteristics of influenza a (h1n1) and a (h3n2) virus strains isolated during the same epidemic season, 1989-1990, in st. petersburg and czsfr was carried out by routine serological methods and by cross-challenge of immunized mice. antigenic differences were found only among serosubtype a (h1n1) strains isolated in different areas. the study was carried out in connection with potential occurrence of influenza epidemic outbreaks from local sources. | 1991 | 1838452 |
| emergence of highly pathogenic virus during selective chicken passage of the prototype mildly pathogenic chicken/pennsylvania/83 (h5n2) influenza virus. | the prototype mildly pathogenic a/chicken/pennsylvania/21525/83 (h5n2) avian influenza virus, which was isolated more than 5 months before the emergence of highly pathogenic virus in the major 1983 pennsylvania outbreak, was examined for the presence of minority subpopulations of highly pathogenic virus. selective serial passage of the parental mildly pathogenic virus in leghorn hens did not lead to recovery of highly pathogenic virus. however, several highly pathogenic reisolates were recovered ... | 1991 | 1838476 |