| activity of cd4+ t-cell clones of type 1 and type 2 in generation of influenza virus-specific cytotoxic responses in vitro. | the activity of distinct cd4+ t-helper cell (th) clones in promoting secondary a/pr/8/34/mt.s.(h1n1) (a/pr8) influenza virus-specific, class i-restricted cytotoxic t-lymphocyte (ctl) responses in vitro was examined. cd8+ t cells which had been purified by fluorescence-activated cell sorter from spleen cells of a/pr8-primed mice were used as responders. on their own, purified cd8+ t cells were unable to generate cytotoxic activity upon in vitro culture with a/pr8-infected stimulator cells. signif ... | 1991 | 1920626 |
| some (not all) influenza watchers suggest 'bad season' lies ahead. | | 1991 | 1920733 |
| [perimyocarditis in influenza a virus infection]. | a 48-year old man was admitted with suspected acute myocardial infarction because of severe precordial pain and monophasic st-elevations in the ecg. the patient's history of an ongoing infection, the localization, extent, and course of the ecg changes as well as the development of a pericardial effusion suggested viral perimyocarditis. the diagnosis was supported by a significant rise of antibodies (seroconversion) against influenza a virus. | 1991 | 1921243 |
| influenza a(h1n1): a widening spectrum? | to study the incidence of h1n1 influenza from 1977 to 1988 in unvaccinated volunteers and the effects of continuing minor antigenic change (antigenic drift) in the virus. | 1991 | 1921782 |
| influenza virus ts61s hemagglutinin is significantly defective in polypeptide folding and intracellular transport at the permissive temperature. | the influenza virus hemagglutinin (ha) temperature-sensitive (ts) mutant, ts61s, contains a nucleotide change in rna segment 4 which leads to an amino acid change at ha1 residue 110 of serine to proline. when ts61s ha is synthesized and maintained at the nonpermissive temperature (39.5 degrees), the ha is defective in transport in the exocytic pathway and is retained in the endoplasmic reticulum (s. nakajima, d. j. brown, m., ueda, k., nakajima, a. suguira, a. k. pattnaik, and d. p. nayak, 1986, ... | 1991 | 1926789 |
| aerosol and intraperitoneal administration of ribavirin and ribavirin triacetate: pharmacokinetics and protection of mice against intracerebral infection with influenza a/wsn virus. | ribavirin is active in vitro but not in vivo against a number of viruses capable of causing encephalitis. ribavirin triacetate (rta), a lipophilic derivative, has been reported to be more effective than ribavirin in protecting animals from encephalitis. by using an influenza a/wsn virus encephalitis model, we demonstrated that rta administered by small-particle aerosol was able to decrease the death rate and increase the time of survival. to determine if this beneficial effect was due to increas ... | 1991 | 1929307 |
| temporal control for translation of influenza virus mrnas. | cdnas for genome rnas of influenza virus a/pr/8/34 were cloned and portions containing the atg initiation codon for translation were inserted into the 5' leader sequence of the chloramphenicol acetyltransferase (cat) gene in a psv2cat vector. in cells that were transfected with a plasmid containing a cdna segment for the early gene and then super-infected with influenza virus, the maximal cat activity was obtained at the early stage of infection. in contrast, a plasmid containing a cdna segment ... | 1991 | 1929878 |
| modification of the cleavage activation of the influenza virus hemagglutinin by site-specific mutagenesis. | factors determining cleavability of influenza virus hemagglutinin which is activated by ubiquitous cellular endoproteases were analysed by carrying out site-directed mutagenesis on the cloned hemaglutinin genes of strains a/fpv/rostock/34 (subtype h7) and a/port chalmers/1/73 (subtype h3). substitutions at the cleavage site of the h7 hemagglutinin indicate that the tetrapeptide arg-x-lys/arg-arg is the minimal consensus sequence recognized by the ubiquitous proteases. the h3 hemagglutinin also b ... | 1991 | 1930091 |
| on the penetration mechanism of influenza viruses. | the envelopes of influenza viruses contain in addition to lipids also two glycoproteins, the hemagglutinin and the neuraminidase, that are responsible for the adsorption, receptor splitting, penetration and budding processes of these viruses. in this article, hypotheses presented in the past with regard to the virus penetration are reconsidered. based on results obtained with the fowl plague virus (influenza a/fpv/rostock/34, h7n1) and mdck-cells, we conclude that a fusion between the viral enve ... | 1991 | 1930099 |
| processing of influenza virus hemagglutinin in insect cells. | | 1991 | 1930101 |
| paramyxovirus tropism dependent on host proteases activating the viral fusion glycoprotein. | an essential step in paramyxovirus fusion (f) glycoprotein biosynthesis is the posttranslational endoproteolytic cleavage of the inactive precursor glycoprotein fo by host cell proteases. when the fo possesses a pair or a cluster of basic residues at the cleavage site, cleavage is catalyzed by a ubiquitous protease(s) and the infection is consequently pantropic. when the site is monobasic with a single arginine, cleavage is allowed to occur only by the enzyme(s) expressed in limited tissue types ... | 1991 | 1930102 |
| synthesis and function of influenza a virus glycoproteins. | the surface glycoproteins of influenza a viruses are the viral components first recognized by the immune system of the infected host, and they are the viral proteins first to contact the infecting cell. cleavage of the hemagglutinin (ha) is the presupposition for the uptake and fusion between viral and endosomal membranes at a relatively low ph. if this cleavage does not occur during synthesis and migration within the cell, an external trypsin-like protease has to activate the virus with a non-c ... | 1991 | 1930103 |
| impact of influenza on morbidity in children with cystic fibrosis. | recommendations concerning annual influenza vaccination in children suffering from cystic fibrosis (cf) are not uniform. previous studies have shown that influenza causes a small proportion of episodes of acute respiratory deterioration in cf patients. during the 1989 australian winter, we studied the association between serologically proven influenza infection and acute respiratory morbidity in 20 children with cf. six children were shown to have influenza infection, four with type a and two wi ... | 1991 | 1931225 |
| interaction of influenza virus hemagglutinin with a lipid monolayer. a comparison of the surface activities of intact virions, isolated hemagglutinins, and a synthetic fusion peptide. | in the infectious entry pathway of influenza virus, the low ph of the endosomal compartment induces an irreversible conformational change in influenza virus hemagglutinin, leading to fusion of viral and endosomal membranes. in the current report, we characterized the low-ph-induced activation of hemagglutinin of influenza strain x31 by studying its interaction with a lipid monolayer. the surface activities of virions, of isolated hemagglutinins and its proteolytic fragments, and of a synthetic p ... | 1991 | 1932037 |
| immunological effects of tumor vaccines: iii. influenza virus oncolysates inhibit the tpa induced activation of peripheral blood mononuclear cells. | this paper investigates the effects of tumor vaccines on t cell proliferation induced by 12-0 tetradecanoylphorbol-13-acetate (tpa). viral oncolysate (vo) tumor vaccines containing inactivated influenza virus a significantly inhibited tpa-induced t cell proliferation. in contrast, a control tumor vaccine (co) that contained the same cellular components as vo but lacked influenza virus did not affect the tpa-induced proliferation. these effects were also observed with peripheral blood mononuclear ... | 1991 | 1932617 |
| association between secretor status and respiratory viral illness. | to determine whether non-secretion of blood group antigens is associated with respiratory virus diseases. | 1991 | 1932971 |
| the effects of influenza virus infection on fev1 in asthmatic children. the time-course study. | to study the time-course of influenza-induced asthma, we retrospectively examined fev1 from five days before to ten days after the onset of illness in 20 asthmatic children aged 8 to 12 years with tolerable respiratory symptoms. influenza infection was confirmed by a rise at least fourfold in serum complement fixation titers. fifteen of 20 patients had decrease in fev1 more than 20 percent from baseline during the acute stage. fev1 began to decrease with the onset of illness in the 15 patients w ... | 1991 | 1935277 |
| efficiency of peptides and lipopeptides for in vivo priming of virus-specific cytotoxic t cells. | synthetic peptides and a novel type of lipopeptide vaccine, both containing t cell epitopes recognized by kd-restricted, influenza virus-specific cytotoxic t cells (ctl) were compared in their efficiency to induce virus-specific ctl in vivo. all attempts to induce virus-specific ctl with synthetic peptide (in the absence of adjuvants) failed. however, a latent immunization was observed, resulting in an increased response to the injected peptide seen only after boosting the recipients with immuno ... | 1991 | 1936113 |
| a b cell population that dominates the primary response to influenza virus hemagglutinin does not participate in the memory response. | the early primary b cell response of balb/c mice to the influenza virus a/pr/8/34 (pr8) hemagglutinin (ha) is dominated by b cells that utilize a single v kappa gene in association with one of two closely related vh genes. we have used an anti-idiotypic reagent that recognizes a light chain-associated idiotope (23-1 id) on these antibodies to follow their presence during the anti-ha response. quantitation of 23-1id+ antibodies at different time points during the anti-ha response indicates that t ... | 1991 | 1936117 |
| antiviral activity of some natural and synthetic sugar analogues. | a number of natural and synthetic sugar analogues have been tested for their antiviral activity, using an influenza virus strain as a model. hemagglutinating titres (ha) and cytopathic effect (cpe) were surveyed to estimate the virus production. it was found that introduction of the benzyl group into these sugars generally causes them to become antivirally active. substitution with methyl, acetyl, uridyl and thiocyanyl groups or derivatization with azido, isopropylidene and benzylidene groups we ... | 1991 | 1936265 |
| fluvirucins a1, a2, b1, b2, b3, b4 and b5, new antibiotics active against influenza a virus. iv. taxonomy on the producing organisms. | the morphology, chemotaxonomy, and cultural and physiological characteristics were examined on the five strains of actinomycetes which produce antiviral antibiotics, fluvirucin congeners. all strains have meso-2,6-diaminopimelic acid in the cell wall. four strains, q464-31, l407-5, r359-5 and r516-16, belong to the maduromycetes since they have madurose in the whole cell. the remaining one strain, r869-90, has rhamnose but no madurose, and is a nocardioform actinomycete. these five strains were ... | 1991 | 1938616 |
| detection and identification of human influenza viruses by the polymerase chain reaction. | a series of oligonucleotide primers are described which hybridize to conserved regions of influenza virus cdna and prime dna synthesis in taq polymerase catalyzed amplification reactions (pcr). primers were designed to hybridize as nested pairs and, following a two-step amplification, produce uniquely sized dna fragments diagnostic for viral type and subtype. influenza a and b matrix-protein genes and the influenza c haemagglutinin gene were targets for the type-specific primers. subtype-specifi ... | 1991 | 1939505 |
| influenza a virus infection of macrophages. enhanced tumor necrosis factor-alpha (tnf-alpha) gene expression and lipopolysaccharide-triggered tnf-alpha release. | we have previously shown that infection of macrophages by influenza a virus is capable of priming for a high tnf-alpha production in response to lps. the present study was designed to examine in more detail tnf-alpha gene expression and tnf-alpha protein release of virus-infected, murine pu5-1.8 macrophages in the presence or absence of low and by itself rather inefficient concentrations of lps (10 ng/ml). although influenza a virus infection alone induced a massive tnf-alpha mrna accumulation, ... | 1991 | 1940351 |
| virulence of rimantadine-resistant human influenza a (h3n2) viruses in ferrets. | the influence of rimantadine-resistance mutations on the virulence of human h3n2 viruses in ferrets was examined. the similarities in virulence of the drug-resistant mutants with single amino acid substitutions at three different locations, 27, 30, and 31, within the m2 sequence and their corresponding sensitive wild-type isolates contrasted with differences in virulence between the three pairs of viruses. these data provide further evidence that rimantadine-resistant viruses that emerge during ... | 1991 | 1940477 |
| involvement of the influenza a virus pb2 protein in the regulation of viral gene expression. | to determine the function(s) of the pb2 protein of influenza a virus, six temperature-sensitive (ts) mutants of a/udorn/72 (h3n2) virus, each carrying a ts mutation in the pb2 gene, were analysed for virus rna and protein synthesis. one of the mutants, icrc27, exhibited unique phenotypes and was characterized in detail. at the non-permissive temperature, 40 degrees c, the accumulation of mrna for each genome segment was reduced severely, leading to delayed and reduced synthesis of viral proteins ... | 1991 | 1940863 |
| sequence analysis of the haemagglutinin (ha) of influenza a (h1n1) viruses present in clinical material and comparison with the ha of laboratory-derived virus. | we used the polymerase chain reaction to amplify the ha1 coding region of influenza a (h1n1) viruses present in clinical material from recent cases of influenza in the u.k. previously, we have demonstrated that isolation of human influenza viruses in embryonated hens' eggs selects variants which have amino acid substitutions in their haemagglutinin (ha) clustering around the receptor-binding site. such egg-selected variants are often antigenically distinct from each other and from corresponding ... | 1991 | 1940864 |
| an indian hospital study of viral causes of acute respiratory infection in children. | from sept. 1986 to jan. 1989, a hospital-based study was conducted on 736 children, under 5 years of age, with acute respiratory infection. nasopharyngeal secretions were examined for viruses by culture and by immunofluorescence. viruses were detected in 22% of specimens: respiratory syncytial (5%), parainfluenza (5%), influenza a (4%), influenza b (2%), adenovirus (3%), measles (3%). the highest rates of detection were with patients diagnosed clinically as pneumonia or upper respiratory tract i ... | 1991 | 1941992 |
| rapid antigenic-type replacement and dna sequence evolution of canine parvovirus. | analysis of canine parvovirus (cpv) isolates with a panel of monoclonal antibodies showed that after 1986, most viruses isolated from dogs in many parts of the united states differed antigenically from the viruses isolated prior to that date. the new antigenic type (designated cpv type 2b) has largely replaced the previous antigenic type (cpv type 2a) among virus isolates from the united states. this represents the second occurrence of a new antigenic type of this dna virus since its emergence i ... | 1991 | 1942246 |
| from the centers for disease control. influenza activity--worldwide, 1990-91. | | 1991 | 1942390 |
| the herald waves of influenza virus infections detected in sendai and yamagata cities in 1985-1990. | the community surveillance of respiratory virus infections performed during 1985-1987 in sendai and 1988-1990 in yamagata has identified a total of five herald waves of influenza virus infections: a/h3n2 virus infections in 1985 and 1989, a/h1n1 virus infections in 1986 and 1988, and type b virus infections in 1989. to investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza a/h1n1 viruses isolated during the 1986 and 1988 herald waves were comp ... | 1991 | 1943849 |
| update: influenza activity--worldwide, 1990-91, and influenza vaccination--united states. | during the 1990-91 influenza season, influenza occurred at relatively low levels throughout much of the world. all reporting countries (except brazil and papua new guinea, which reported epidemic levels) indicated either sporadic cases, small local outbreaks, or regional outbreaks. this report summarizes worldwide influenza activity reported from april through september 1991. | 1991 | 1944118 |
| update: influenza activity--united states, 1991-92. | from late october through november 20, 1991, state health departments reported outbreaks of culture-confirmed influenza a(h3n2) in public schools in texas and a university in tennessee. in addition, alabama, georgia, minnesota, north carolina, ohio, and tennessee reported outbreaks of culture-confirmed influenza a (not subtyped) in schools. in these outbreaks, school absentee rates ranged from 11% to 40%; school closures were reported in ohio and tennessee. | 1991 | 1944132 |
| immunogenicity of trivalent subunit and split influenza vaccines (1989-90 winter season) in volunteers of different groups of age. | trivalent split or subunit influenza vaccines [a/shangai/11/87 (h3n2), a/singapore/6/86 (h1n1) and b/yamagata/16/88] recommended for the 1989-90 winter season and licensed in italy, were administered to 149 volunteers of three different age groups (elderly, middle-aged and young). antibody production was determined in pre- and postvaccination sera by haemagglutinin inhibition test and the results were evaluated as protection and response rates. the split vaccine was more immunogenic than the sub ... | 1991 | 1950094 |
| [the evaluation of the reactogenicity and immunological activity of an inactivated 3-component influenza vaccine with an elevated hemagglutinin concentration in the inoculation dosage]. | in this work the reactogenic properties and antigenic potency of inactivated trivalent influenza vaccine, obtained by elution and centrifugation and containing up to 9-11 micrograms of hemagglutinin for influenza viruses a(h1n1) and a(h3n2) and up to 14 micrograms for influenza virus b, were studied. the reactogenicity of the preparation was found to correspond to the regulations. the immunogenic potency characteristics of individual batches of this trivaccine were higher than the immunogenicity ... | 1991 | 1950267 |
| prevention of influenza in high-risk patients: 1991-92 vaccination guidelines. | | 1991 | 1951040 |
| emergence and possible transmission of amantadine-resistant viruses during nursing home outbreaks of influenza a (h3n2). | outbreaks of influenza a (h3n2, a/shanghai/11/87-like) occurred in two partially (60% and 79%) vaccinated nursing home populations in january 1988. a retrospective cohort study using chart review was designed to assess the effectiveness of influenza vaccination and amantadine prophylaxis (100 mg per day) in controlling the outbreaks and to determine the amantadine susceptibility of influenza viruses isolated from case-patients. the point estimate of vaccine efficacy in preventing influenza-like ... | 1991 | 1951297 |
| recovery of drug-resistant influenza a virus during therapeutic use of rimantadine. | the therapeutic activity of rimantadine and its relationship to the shedding of drug-resistant influenza a virus were assessed in two randomized, double-blind, placebo-controlled trials involving patients with laboratory-documented influenza a virus (h3n2 subtype) illness of 2 days' duration or less. in a family-based study, rimantadine treatment for 10 days (24 children and adults) was associated with significant decreases in the number of days to a 50% reduction in symptoms (mean difference, 2 ... | 1991 | 1952841 |
| the neutral theory of molecular evolution: a review of recent evidence. | in sharp contrast to the darwinian theory of evolution by natural selection, the neutral theory claims that the overwhelming majority of evolutionary changes at the molecular level are caused by random fixation (due to random sampling drift in finite populations) of selectively neutral (i.e., selectively equivalent) mutants under continued inputs of mutations. the theory also asserts that most of the genetic variability within species at the molecular level (such as protein and dna polymorphism) ... | 1991 | 1954033 |
| translocation of peptides through microsomal membranes is a rapid process and promotes assembly of hla-b27 heavy chain and beta 2-microglobulin translated in vitro. | we have translated major histocompatibility complex (mhc) class i heavy chains and human beta 2-microglobulin in vitro in the presence of microsomal membranes and a peptide from the nucleoprotein of influenza a. this peptide stimulates assembly of hla-b27 heavy chain and beta 2-microglobulin about fivefold. by modifying this peptide to contain biotin at its amino terminus, we could precipitate hla-b27 heavy chains with immobilized streptavidin, thereby directly demonstrating class i heavy chain- ... | 1991 | 1955465 |
| dominant-negative mutants as antiviral agents: simultaneous infection with the cold-adapted live-virus vaccine for influenza a protects ferrets from disease produced by wild-type influenza a. | the attenuated cold-adapted strain of influenza a virus that is a candidate live-virus vaccine suppressed clinical disease in ferrets when given simultaneously with a virulent epidemic strain of influenza a virus. the cold-adapted virus effectively prevented disease, even when the epidemic strain was of a different subtype than the attenuated virus. in this case, ferrets given a mixed inoculum produced antibody to both subtypes in the absence of clinical disease, indicating that both viruses are ... | 1991 | 1955719 |
| intraepidemic variants of influenza virus h3 hemagglutinin differing in the number of carbohydrate side chains. | during the epidemic outbreak in the region of greifswald in the winter 1974/75, we found influenza virus variants which showed differences in the electrophoretic mobility of ha. among the 25 isolates 13 were of slower and 12 of higher mobility. ha1 of 6 isolates was studied by determining the number of the carbohydrate side chains and by direct sequencing of vrna. evidence is presented that variants showing a slower electrophoretic mobility of ha1 had consistently acquired a seventh carbohydrate ... | 1991 | 1958130 |
| an unusual community outbreak of influenza a. | the hong kong h3n2 subtype of influenza a virus appeared in 1968 and since then has caused epidemics of varying degrees of severity. we describe a community outbreak of influenza a h3n2 which occurred in members of a bowls club in an english rural village in late april 1989. the explosive onset, high attack rate (34/41 = 83 per cent) in those exposed, and the clinical presentation initially suggested a toxic or allergic aetiology. twenty-three persons consulted their general practitioners; befor ... | 1991 | 1958413 |
| influenza serosurvey for 1991-1992 season. prevalence of antibody to current influenza virus strains in a 1991 canadian serosurvey. | | 1991 | 1959137 |
| control of influenza a outbreaks in nursing homes: amantadine as an adjunct to vaccine--washington, 1989-90. | outbreaks of influenza a virus infection can cause substantial morbidity and mortality among residents of nursing homes. surveillance for the 1991-92 influenza season indicates that the dominant circulating viruses are influenza a (1), for which amantadine hydrochloride is effective for prevention and treatment (2). this report describes the use of amantadine as an adjunct to influenza vaccine for controlling an influenza a(h3n2) outbreak that occurred in a washington nursing home during the 198 ... | 1991 | 1961174 |
| update: influenza activity and vaccine availability--united states, 1991-92. | during the 1991-92 influenza season, widespread influenza-like illness (ili) activity* was first reported in louisiana for the week ending november 9, 1991, and in mississippi the week ending november 16. through november 30, six additional states (alaska, missouri, new york, north carolina, tennessee, and texas) reported widespread activity; 13 (alabama, arkansas, california, florida, georgia, indiana, kansas, kentucky, minnesota, nebraska, new jersey, ohio, and pennsylvania) reported regional ... | 1991 | 1961177 |
| the effect of virus particle size on chemiluminescence induction by influenza and sendai viruses in mouse spleen cells. | suspensions of orthomyxo- and paramyxoviruses are composed of pleomorphic particles ranging from large filaments to small spheres. influenza and sendai viruses were separated according to size by gel filtration and the induction of luminol-dependent chemiluminescence (cl) by particles of similar size was studied in suspensions of mouse spleen cells known to contain phagocytes. cl reflects the generation by the cells of reactive oxygen species. cl induction decreased with particle size for both v ... | 1990 | 1963614 |
| viruses associated with acute lower respiratory tract infections in children from the eastern highlands of papua new guinea (1983-1985). | this study, conducted at goroka hospital from january 1983 to june 1985, examined the viruses identified in nasopharyngeal aspirates (npa) and urines collected from 716 hospitalised children with moderate or severe pneumonia, in npa from 170 children with mild pneumonia treated as outpatients and in npa from a control group of 428 children attending the outpatient department of goroka hospital suffering from minor ailments other than upper or lower respiratory tract infections. one or more virus ... | 1990 | 1963705 |
| inhibitory effect of a new antibiotic, guanine 7-n-oxide, on the replication of several rna viruses. | guanine 7-n-oxide (g-7-ox) was examined for its antiviral activity against 9 viruses based on plaque reduction, neuraminidase activity reduction, a fluorescent antibody technique or elisa. the following viruses were included in the tests: influenza, sendai, simian virus 5 (sv5), respiratory syncytial, western equine encephalitis, japanese encephalitis, vesicular stomatitis, rabies and polio. g-7-ox showed broad anti-rna viral activity against all viruses tested, except for poliovirus. inhibition ... | 1990 | 1964374 |
| [studies of the adaptation of influenza viruses to lowered temperatures of replication. ii. studies in vivo]. | swiss white mice were given intranasally suspension of influenza a virus (h3n2) isolated at different period of time and replicated in lowered temperatures in 11 days old chicken embryos. the presence of antigen in lung of animals was detected by if. they were given the virus replicated at 30 degrees c at different rate depending on strain tested. no distinct differences were observed in haemagglutination inhibition antibody level. on the other hand the level of neuraminidase activity inhibiting ... | 1990 | 1964991 |
| evaluation of the toxicity and antiviral activity of carbocyclic 3-deazaadenosine against respiratory syncytial and parainfluenza type 3 viruses in tissue culture and in cotton rats. | the toxicity and antiviral efficacy of carbocyclic 3-deazaadenosine (cc3ado) against respiratory syncytial (rsv) and parainfluenza type 3 (piv3) virus infections were tested in tissue culture and in cotton rats. the mean median efficacious dose (ed50) of cc3ado in hep2 cells against rsv and piv3 was 9 and 14 micrograms/ml, respectively. these values were 85- and 55-fold less than the median inhibitory (toxic) dose (id50) of cc3ado in this cell line (750 micrograms/ml), and similar to values obta ... | 1990 | 1965109 |
| [the incidence of exacerbations in chronic diseases in patients hospitalized with influenza and para-influenza]. | a retrospective analysis was made of the case reports of 829 patients admitted to the infectious department with a diagnosis of influenza (592) and parainfluenza (237). in all the patients, the diagnosis was supported serologically with the aid of the hemagglutination inhibition test, with the antibody titer in the serum rising 4-fold and more. in part of the patients the indicated test was used in combination with the immunofluorescence test in studying nasopharyngeal smears, whereas in part of ... | 1990 | 1965617 |
| [respiratory viral infections in young children 1988-1990]. | from october 1988 to june 1989 the studies on viral infections of respiratory tract were done in specimens taken from 461 children, aged 0-2 years. similarly to the observations in previous epidemic seasons infections due to rs and parainfluenza type 3 viruses were dominated. these studies included also influenza type c and parainfluenza type 4 viruses with unknown epidemiology in poland. the insignificant role of these infections in small children was estimated according to the low ratio of det ... | 1990 | 1966118 |
| influenza a (h3n2) component of recommended vaccine induces antibody to current virus. | | 1990 | 1967480 |
| class ii mhc molecules can use the endogenous pathway of antigen presentation. | models for antigen presentation have divided the world of antigens into two categories, endogenous and exogenous, presented to t cells by class i and class ii major histocompatibility complex (mhc) encoded molecules, respectively. exogenous antigens are though to be taken up into peripheral endosomal compartments where they are processed for binding to class ii mhc molecules. endogenous antigens are either synthesized or efficiently delivered to the cytoplasm before being partially degraded in a ... | 1990 | 1967486 |
| differential sensitivity of human t helper cell pathways by in vitro exposure to cyclosporin a. | cyclosporin a (csa) is a widely used agent for the prevention of tissue allograft rejection in human transplantation. as a result of the recent demonstration that the allospecific th cell response of human pbl can be generated by three distinct pathways of th cell and apc interactions, we investigated the sensitivity of these three th-apc pathways, as well as the th response to recall ag, to different concentrations of csa. pbl from healthy volunteer donors were set up as primary in vitro cultur ... | 1990 | 1969447 |
| increased serum neopterin in patients with hiv-1 infection is correlated with reduced in vitro interleukin-2 production. | recently we have observed that the cd4+ t cell response of peripheral blood mononuclear cells (pbmc) to soluble antigens is the first to be lost in the course of hiv-1 infection followed by the loss of response to hla alloantigens. in this study we compared serum neopterin concentrations of individuals with early stages of hiv-1 infection (stages wr1 and wr2, walter reed staging system) with in vitro interleukin-2 (il-2) production of pbmc in response to stimulation with soluble antigens (influe ... | 1990 | 1969780 |
| modern vaccines. pneumococcus and influenza. | | 1990 | 1969994 |
| circumvention of defective cd4 t helper cell function in hiv-infected individuals by stimulation with hla alloantigens. | pbl from approximately 50% of asymptomatic individuals infected with hiv have been previously demonstrated to exhibit defective in vitro th function that is selective for influenza a virus (flu), but not for hla alloantigens (allo). in this report, we have further studied hiv+ individuals with this selective th defect, and demonstrate that defective in vitro ctl responses to flu can be restored by costimulation with flu + allo. in contrast, hiv+ patients who have lost th responses to allo were u ... | 1990 | 1970348 |
| analysis of the role of leukocyte function-associated antigen-1 in activation of human influenza virus-specific t cell clones. | the role of leukocyte function-associated ag-1 (lfa-1) in intercellular adhesion is well documented. previously, we demonstrated that the lfa-1 molecule (cd11a/cd18) can also regulate the induction of proliferation of peripheral blood t cells. in these studies, we observed opposite effects of antibodies against cd11a (lfa-1-alpha-chain) or cd18 (lfa-1-beta-chain). here, we determined the effects of anti-cd11a and anti-cd18 mab on proliferation of cloned influenza virus-specific t cells. anti-cd1 ... | 1990 | 1970349 |
| the influence of endogenous hypocorticism on the replication of influenza virus in the mouse lungs and the production of specific antibodies. | the replication of pathogenic influenza virus a/pr/8/34 in the lungs and the synthesis of virus-neutralizing (vn) and haemagglutination-inhibition (hi) antibodies has been studied in mice with endogenous hypocorticism induced by a bilateral adrenalectomy. the adrenalectomized mice appeared to be more susceptible to influenza infection as compared to the mock-operated ones. this was evident from earlier deaths and higher death rate in mice inoculated with 50 eid50, 1000 eid50, and 6000 eid50 of t ... | 1990 | 1975723 |
| [the role of disorders in the central mechanisms of neurohumoral regulation in the outcome of a viral infection (experimental influenza)]. | | 1990 | 1980243 |
| primary structure of the gene coding for the haemagglutinin of influenza virus a/leningrad/385/80(h3n2): detection of a point mutation responsible for the antigenic drift. | primary structure of the gene coding for haemagglutinin (ha-gene) of influenza virus a/leningrad/385/80(h2n2) isolated during the epidemics of influenza in leningrad in 1980 was determined. the close relationship of ha gene of this virus to the corresponding gene of the virus a/bangkok/1/79(h3n2) was confirmed. it was shown that a single mutation in an antigenic site (the change from isoleucine to leucine at position 51 of ha1 gene) caused an antigenic drift. one silent mutation was detected (nu ... | 1990 | 1980394 |
| antiviral activities of pyrimidine nucleoside analogues: some structure--activity relationships. | seventeen nucleoside derivatives (derived from arabinosylcytosine, resp. cytidine, 5-fluorouracil and uracil) were tested by agar-diffusion plaque-inhibition test for their antiviral activity with herpes simplex, vaccinia, fowl plague, newcastle disease and western equine encephalomyelitis viruses. the highest antiviral activity against dna viruses exhibited arabinosylcytosine, n4-acylarabinosylcytosines, arabinosylthiouracil, cyclocytidine and its 5'-chloroderivative. rna viruses were inhibited ... | 1990 | 1981442 |
| influenza virus detection in clinical specimens. | the authors compared the results of influenza a (h1n1) and influenza a (h3n2) virus detection in nasopharyngeal swabs from flu patients by molecular hybridization (mh), elisa, virus isolation and seroconversion. using the immunofluorescence (if) technique influenza virus was detected in cell suspensions from the first chick embryo passage. altogether 63 swabs from various epidemic seasons were separated into 3 groups according to specimen sampling and storage. it was shown that influenza virus r ... | 1990 | 1981455 |
| radioimmunoassay and oligonucleotide mapping of a/hswln1 influenza viruses isolated from humans and animals. | | 1990 | 1981460 |
| interleukin-1-inhibitor activity induced by respiratory syncytial virus: abrogation of virus-specific and alternate human lymphocyte proliferative responses. | respiratory syncytial virus (rsv) infection has been shown to induce human mononuclear leukocyte (mnl) production of net interleukin-1 (il-1)-inhibitor activity. in the current studies of il-1-inhibitor effects, rsv-exposed cells were compared with autologous mnl that were sham-exposed or exposed to inactivated rsv or influenza virus (which induces net il-1 activity and commonly elicits effective homotypic immunity). exposure of mnl to influenza virus or inactivated rsv resulted in increased exp ... | 1991 | 1984478 |
| the n2 neuraminidase of human influenza virus has acquired a substrate specificity complementary to the hemagglutinin receptor specificity. | a survey of 10 human influenza a viruses of the n2 serotype, isolated between 1957 and 1987, has revealed a drift in neuraminidase linkage specificity. while the earliest n2 strains examined exhibit strict specificity for cleavage of the neuac alpha 2,3gal sequence, n2 isolates from 1967 to 1968 also show limited activity towards the neuac alpha 2,6gal linkage. in strains isolated in 1972 and later, the n2 neuraminidase has approximately equal activity towards both types of linkages. the neuac a ... | 1991 | 1984642 |
| retarded processing of influenza virus hemagglutinin in insect cells. | when expressed in spodoptera frugiperda cells by a baculovirus vector, the hemagglutinin of fowl plague virus has been found to contain palmitic acid in covalent hydroxylamine-sensitive linkage, indicating that these cells have the capacity to acylate foreign proteins at cysteine residues. centrifugation on sucrose density gradients and immune precipitation with conformation-specific antibodies were used to compare trimerization of the hemagglutinin in insect cells and in fowl plague virus-infec ... | 1991 | 1984645 |
| interferon-induced proteins: identification of mx proteins in various mammalian species. | mx protein controls influenza virus pathogenicity in mice in vivo. it is an abundant protein synthesized in response to interferon-alpha/beta. searches for homolog proteins in various animal species have been conducted using several methods: (1) radioactive labeling of proteins induced by interferon and analysis by 2-d gel electrophoresis, (2) immunoprecipitation, (3) protoblot-elisa analysis of cell-protein extracts, and (4) immunostaining of fixed cells. all mammalian species tested so far (in ... | 1991 | 1984648 |
| the genes associated with trans-dominance of the influenza a cold-adapted live virus vaccine. | segment 7 (m) of the cold-adapted live influenza a virus vaccine plays a primary role in the ability of this virus to interfere with the replication of wild-type influenza a viruses. this conclusion is based on several lines of evidence. single gene reassortant viruses derived by crossing influenza a/ann arbor/6/60 (h2n2) cold-adapted donor virus with an epidemic wild-type strain, a/korea/1/82 (h3n2), were tested for their ability to interfere with wild-type parental virus in the madin-darby lin ... | 1991 | 1984670 |
| transport of incoming influenza virus nucleocapsids into the nucleus. | upon penetration of the influenza virus nucleocapsid into the host cell cytoplasm, the viral rna and associated proteins are transported to the nucleus, where viral transcription and replication occur. by using quantitative confocal microscopy, we have found that over half of cell-associated nucleoprotein (np) entered the nucleus with a half time of 10 min after penetration into cho cells. microinjection and immunoelectron microscopy experiments indicated that the np entered the nucleus through ... | 1991 | 1985199 |
| two signals mediate nuclear localization of influenza virus (a/wsn/33) polymerase basic protein 2. | polymerase basic protein 2 (pb2), a component of the influenza virus polymerase complex, when expressed alone from cloned cdna in the absence of other influenza virus proteins, is transported into the nucleus. in this study, we have examined the nuclear translocation signal of pb2 by making deletions and mutations in the pb2 sequence. our studies showed that two distant regions in the polypeptide sequence were involved in the nuclear translocation of pb2. in one region, four basic residues (k-73 ... | 1991 | 1985200 |
| reassociation with beta 2-microglobulin is necessary for db class i major histocompatibility complex binding of an exogenous influenza peptide. | a synthetic peptide corresponding to residues 365-380 of the influenza nucleoprotein (np365-380) has been previously shown to associate with class i major histocompatibility complex-encoded molecules and to stimulate cytotoxic t lymphocytes [townsend, a. r. m., rothbard, j., gotch, f. m., bahadur, g., wraith, d. & mcmichael, a. j. (1986) cell 44, 959-968]. we find that intact db class i heterodimers on the cell surface are unreceptive to binding this antigen. however, np365-380 readily associate ... | 1991 | 1986378 |
| antiviral drug therapy. | major advances in molecular virology have led to the development of new antiviral compounds. these drugs include ribavirin, used in the treatment of severe respiratory syncytial virus infection in children; amantadine, used in the prophylaxis and treatment of influenza a infection; acyclovir, used in a variety of herpesvirus infections, including primary gingivostomatitis, genital herpes and herpes zoster; ganciclovir, used in the treatment of retinitis due to cytomegalovirus, and zidovudine, us ... | 1991 | 1986488 |
| attachment of influenza a virus to ferret tracheal epithelium at different maturational stages. | influenza virus attaches primarily to ciliated cells in mature airways epithelium. this process is mediated by a viral envelope glycoprotein (hemagglutinin) that binds to sialic acid-containing receptors in the apical membrane of host cells. the purpose of this study was to determine the cellular distribution of these receptors as a function of tracheal epithelial maturation in the ferret, which is susceptible to influenza virus infection at all ages and undergoes postnatal ciliation. to assay f ... | 1991 | 1986780 |
| toxic shock syndrome following influenza a in a child. | | 1991 | 1986879 |
| comparison of heterotypic protection against influenza a/taiwan/86 (h1n1) by attenuated and inactivated vaccines to a/chile/83-like viruses. | children (n = 192) aged 3-19 years from 98 families completed this double-blind, placebo-controlled study comparing the efficacy of a bivalent attenuated (cr) vaccine with trivalent inactivated (ti) vaccine. both vaccines contained a/chile/83 (h1n1)-like antigens. after vaccination the geometric mean titer to a/taiwan/86 (h1n1) was 1:36 in the cr group, 1:92 in the ti group, and 1:5 in the placebo group. during the influenza a/taiwan/86 (h1n1) epidemic, 21.4% of cr recipients, 16.7% of ti recipi ... | 1991 | 1988512 |
| gastrointestinal bleeding with influenza virus. | seven children who presented during the influenza a(h1n1) epidemic of 1988 are described. after a typical influenzal illness, they developed haematemesis of varying severity. endoscopy revealed haemorrhagic gastritis. laboratory evidence of influenza a(h1n1) virus infection was present. two children died as a result of their illness. the association of virus and gastrointestinal haemorrhage is explored. | 1991 | 1988788 |
| structural characteristics of the m2 protein of influenza a viruses: evidence that it forms a tetrameric channel. | the evidence presented shows that the m2 protein of influenza a viruses exists in infected cells as a homotetramer composed of two disulfide-linked dimers held together by noncovalent interactions. the amphiphilic nature of the transmembrane alpha-helical domain is consistent with the protein forming a transmembrane channel with which amantadine, the specific anti-influenza a drug, interacts. together these features provide a structural basis for the hypothesis that m2 has a proton translocation ... | 1991 | 1989386 |
| avian cells expressing the murine mx1 protein are resistant to influenza virus infection. | the cdna encoding the murine mx1 protein, a mediator of resistance to influenza virus, was inserted into a replication-competent avian retroviral vector in either the sense (referred to as mx+) or the antisense (referred to as mx-) orientation relative to the viral structural genes. both vectors produced virus retaining the mx insert (mx recombinant viruses referred to as mx+ and mx-) following transfection into chicken embryo fibroblasts (cef). mx protein of the appropriate size and nuclear loc ... | 1991 | 1989389 |
| influenza virus enhancement of membrane leakiness induced by staphylococcal alpha toxin, diphtheria toxin and streptolysin s. | release of alpha-amino[14c]isobutyric acid from ferret mpf cells was promoted by staphylococcal alpha toxin, diphtheria toxin and streptolysin s. this release was enhanced to a significant extent if the cells had been previously infected with influenza virus strain a/puerto rico/8/34 (pr8, h1n1), although infection with virus alone did not increase the release of radiolabel as compared with that from untreated cells; inactivated virus had a similar enhancing action. the mechanism of enhancement ... | 1991 | 1990059 |
| direct isolation in eggs of influenza a (h1n1) and b viruses with haemagglutinins of different antigenic and amino acid composition. | influenza a (h1n1) and influenza b viruses from clinical samples were isolated in the amniotic cavity of embryonated hens' eggs by classical techniques and propagated in the allantoic cavity. virus progeny from different eggs which had been inoculated with virus material from the same clinical sample possessed antigenically distinguishable haemagglutinins (has). virus progeny of some eggs possessed has which were serologically identical to those of virus isolated in parallel in mammalian (mdck) ... | 1991 | 1990062 |
| the specific inhibition of influenza a virus maturation by amantadine: an electron microscopic examination. | amantadine specifically inhibits the release of virus particles from cells infected with the rostock (h7n1) strain of influenza a virus, apparently as a consequence of a membrane protein m2-mediated conversion of haemagglutinin (ha) to its low ph conformation. electron microscopic observations, together with immunogold labelling, showed that amantadine action does not alter the distribution of ha on the cell surface nor does it prevent the formation of budding virus particles. it was not possibl ... | 1991 | 1990063 |
| bronchial hyperresponsiveness in normal subjects during attenuated influenza virus infection. | fourteen healthy male subjects with hemagglutination-inhibition antibody titers of 1:8 or less to homologous influenza a virus were studied. six subjects received live, attenuated influenza virus by nasal drops and by aerosol. although infection occurred in these six subjects, with the development of 4-fold or greater increases in hemagglutination-inhibition antibody titers, they remained asymptomatic. eight subjects received placebo via the same route, and did not develop symptoms and showed no ... | 1991 | 1990953 |
| a dominant idiotype in the antibody response against the influenza virus hemagglutinin. serum and in situ analyses. | py206 is an id associated with a balb/c murine mab described as being specific for the influenza a virus hemagglutinin. however, production of this id by balb/c mice immunized with influenza is low. this report shows that the py206 id is a dominant component of the anti-influenza antibody response in c57bl/6j strain mice infected intranasally with the influenza a/hong kong/168/(h3n2)[r] x-31 virus. high py206 id expression was linked to the ighb ig allotype locus. py206 id+ antibody-forming cell ... | 1991 | 1993846 |
| age distribution of patients with medically-attended illnesses caused by sequential variants of influenza a/h1n1: comparison to age-specific infection rates, 1978-1989. | since influenza a/h1n1 viruses reappeared during the 1977-1978 season, this subtype has contributed 27% of 6,609 documented influenza infections of persons with acute respiratory disease presenting to clinics serving as surveillance sites of the influenza research center in houston for the 12-year period ending june 1989. wide differences in the distribution of h1n1 viruses occurred by age group: more than 50% of h1n1 infections were detected among persons aged 10-34 years, compared with 28% for ... | 1991 | 2000847 |
| three antibody molecules can bind simultaneously to each monomer of the tetramer of influenza virus neuraminidase and the trimer of influenza virus hemagglutinin. | trimeric hemagglutinin and tetrameric neuraminidase molecules isolated from influenza virus bind an average of 9 and 13 molecules respectively of monovalent antibody fragments prepared from igg isolated from polyclonal sera. in each case this represents an average of approximately three molecules of antibody binding to each protomer. although there is compelling evidence for the presence of multiple adjacent and overlapping epitopes covering the surface of these two viral antigens, steric hindra ... | 1991 | 2001177 |
| fusion activity of influenza virus pr8/34 correlates with a temperature-induced conformational change within the hemagglutinin ectodomain detected by photochemical labeling. | fusion of influenza viruses with membranes is catalyzed by the viral spike protein hemagglutinin (ha). under mildly acidic conditions (approximately ph 5) this protein undergoes a conformational change that triggers the exposure of the "fusion peptide", the hydrophobic n-terminal segment of the ha2 polypeptide chain. insertion of this segment into the target membrane (or viral membrane?) is likely to represent a key step along the fusion pathway, but the details are far from being clear. the pho ... | 1991 | 2001371 |
| amantadine for influenza a. | | 1991 | 2004163 |
| evolutionary pathways of n2 neuraminidases of swine and human influenza a viruses: origin of the neuraminidase genes of two reassortants (h1n2) isolated from pigs. | the complete nucleotide sequences of the neuraminidase (na) genes of two reassortant (h1n2) and two h3n2 influenza a viruses isolated from pigs were determined and phylogenetic relationships between these and previously reported n2 na genes were investigated. on the basis of pairwise nucleotide sequence identity, the na genes of two reassortants, a/sw/kanagawa/2/78 and a/sw/ehime/1/80, were most closely related to those of human influenza a virus strains isolated in 1972 and the earliest availab ... | 1991 | 2005434 |
| homotypic and heterotypic protection against influenza virus infection in mice by recombinant vaccinia virus expressing the haemagglutinin or nucleoprotein of influenza virus. | recombinant vaccinia virus expressing the influenza virus haemagglutinin (ha) or nucleoprotein (np) genes from a/sw/hong kong/1/74 (h1n1) under the control of a hybrid promoter containing the p7.5 early promoter element and promoter of the gene encoding the major protein of cowpox virus a type inclusion body was constructed to investigate protective immunity against homologous and heterologous viruses in mice. these recombinant vaccinia viruses produced authentic influenza virus ha and np in inf ... | 1991 | 2005435 |
| [influenza and death. high mortality not only due to the great epidemics]. | excess mortality in a population is one of the hallmarks of an influenza epidemic. apart from the pandemic years, 1918-1919, 1957 and 1968-1969, annual excess mortality has occurred 16 times in sweden during the period 1911-1988. an unusually high mortality was caused by influenza a sichuan 2/87 (h3n2), the unexpected appearance of which at the beginning of november 1988 started an intensive epidemic in sweden, while other european countries had a relatively mild influenza season. swedish deaths ... | 1991 | 2008131 |
| influenza vaccines. | | 1991 | 2008259 |
| influenza virus sialidase: effect of calcium on steady-state kinetic parameters. | ca2+ increases the initial rate of activity of sialidase from influenza virus (a/tokyo/3/67). increasing ionic strength also activates influenza virus sialidase. when ionic strength is controlled, smaller but still significant ca2+ effects are observed, with vmax/km increased from 0.8.10(5) to 1.4.10(5) m-1 s-1 and vmax increased from 6.3 to 9.5 s-1 by saturating ca2+. the ki of the competitive inhibitor 2,3-dehydro-2-deoxy-n-acetylneuraminic acid was decreased from 2.7.10(-6) to 1.15.10(-6) m a ... | 1991 | 2009295 |
| conjunctivitis associated with a mycoplasma-like organism in swine. | a midwestern producer reported high incidence of conjunctivitis and keratoconjunctivitis in a herd of crossbred finishing swine. complete necropsy was performed on 3 pigs with bilateral mucopurulent conjunctivitis and chemosis; other gross lesions were not seen. mycoplasma sp was isolated from conjunctival swab specimens obtained from 1 pig; small numbers of streptococci and coagulase-negative staphylococci were isolated from conjunctival swab specimens from all 3 pigs. neither swine influenza v ... | 1991 | 2010341 |
| mutants and revertants of an avian influenza a virus with temperature-sensitive defects in the nucleoprotein and pb2. | ts19 is a temperature-sensitive (ts) mutant of the influenza a fowl plague virus with a defect in the nucleoprotein (np). in ts19-infected chicken embryo cells all viral components are synthesized in normal yields at the nonpermissive temperature, but infectious virus is not formed. under these conditions the migration of the np and m of ts19 from the cell nucleus to the cytoplasm is affected. this ts defect is due to a single amino acid replacement (r162k) in a completely conserved region of th ... | 1991 | 2014635 |
| antigenic and genetic variation in influenza a (h1n1) virus isolates recovered from a persistently infected immunodeficient child. | antigenic and genetic variations have been analyzed in eight consecutive isolates recovered from a child with severe combined immunodeficiency syndrome persistently infected with naturally acquired type a (h1n1) influenza virus over a 10-month period. hemagglutination inhibition reactions and t1 oligonucleotide fingerprinting demonstrated that these viruses were related to strains causing outbreaks in the united states at that time (1983 to 1984) but that antigenic and genetic differences betwee ... | 1991 | 2016763 |
| high-efficiency formation of influenza virus transfectants. | cdna-derived rnas were introduced into the genomes of influenza viruses by using an improved ribonucleoprotein (rnp) transfection protocol. up to 10(5) viral transfectants with a novel neuraminidase gene could be obtained by using a 35-mm dish (10(6) cells) for rnp transfection. in addition to genes coding for surface proteins (hemagglutinin and neuraminidase), we also exchanged a gene coding for nonsurface proteins. the cdna-derived influenza a/pr/8/34 virus ns gene was introduced into a temper ... | 1991 | 2016777 |
| from the centers for disease control. influenza activity--united states and worldwide, and composition of 1991-92 influenza vaccine. | | 1991 | 2016824 |
| synthetic peptides as the basis for vaccine design. | | 1991 | 2017193 |