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the avian influenza virus nucleoprotein gene and a specific constellation of avian and human virus polymerase genes each specify attenuation of avian-human influenza a/pintail/79 reassortant viruses for monkeys.reassortant viruses which possessed the hemagglutinin and neuraminidase genes of wild-type human influenza a viruses and the remaining six rna segments (internal genes) of the avian a/pintail/alberta/119/79 (h4n6) virus were previously found to be attenuated in humans. to study the genetic basis of this attenuation, we isolated influenza a/pintail/79 x a/washington/897/80 reassortant viruses which contained human influenza virus h3n2 surface glycoprotein genes and various combinations of avian o ...19872441080
fine specificity of murine class ii-restricted t cell clones for synthetic peptides of influenza virus hemagglutinin. heterogeneity of antigen interaction with the t cell and the ia molecule.we have previously demonstrated diversity in the specificity of murine, h-2k class ii-restricted, t cell clones for the hemagglutinin (ha) molecule of h3n2 influenza viruses and have mapped two t cell determinants, defined by synthetic peptides, to residues 48-68 and 118-138 of ha1. in this study we examine the nature of the determinant recognized by six distinct p48-68-specific t cell clones by using a panel of truncated synthetic peptides and substituted peptide analogs. from the peptides test ...19882453566
[experimental study of the prophylactic anti-influenza and interferon-inducing activity of epsilon-aminocaproic acid].epsilon-aminocaproic acid, an original antifibrinolytic had a rapid and prolonged protective effect, thus lowering the death rate of experimental mice contaminated with virulent strains of the influenza virus. the protective effect of the acid was observed after its intraperitoneal administration in a dose of 20 mg/mouse 24 hours before contamination by the strain with the h3n2 antigenic formula and after intranasal application of 15 mg of epsilon-aminocaproic acid divided into 2 doses 2 days be ...19882454085
a region of the influenza a/nt/60/68 pb2 protein containing an antigenic determinant recognized by murine h-2dd restricted cytotoxic t lymphocytes.we have used a recombinant vaccinia virus to investigate the recognition of the pb2 protein of influenza a/nt/60/68 (h3n2) by murine polyclonal ctl populations. pb2 is recognized as a major cross-reactive target antigen. recognition of pb2 is under strict genetic control, since balb/c (h-2d) but not cba (h-2k) mice are responders. we also demonstrate, by use of cell lines transfected with individual genes encoding class i molecules of the h-2d haplotype, that recognition of pb2 occurs in conjunc ...19882460995
the structural requirements for class ii (i-ad)-restricted t cell recognition of influenza hemagglutinin: b cell epitopes define t cell epitopes.a majority of i-ad-restricted cd4+ clones elicited by influenza x31 (h3n2) virus infection, recognize a synthetic peptide of hemagglutinin (ha) corresponding to an antibody binding region of the ha1 subunit (site b: ha1 177-199). the structural requirements for class ii-restricted t cell recognition were investigated by determining the proliferative responses of representative cd4+ clones to truncated ha1 peptides and synthetic peptide analogues. two distinct t cell epitopes were identified and ...19892468504
4-o-acetyl-n-acetylneuraminic acid in the n-linked carbohydrate structures of equine and guinea pig alpha 2-macroglobulins, potent inhibitors of influenza virus infection.to investigate the molecular basis of the differential ability of human, equine, and guinea pig alpha 2-macroglobulins to inhibit hemagglutination and infectivity of a human influenza virus, a/memphis/102/72 (h3n2), the structures of oligosaccharides released from the three glycoproteins by hydrazinolysis were analyzed comparatively. approximately seven to eight sugar chains were released from each subunit of two potent inhibitors (equine and guinea pig alpha 2-macroglobulins) and a weak inhibit ...19892470764
induction of immune response to influenza virus with anti-idiotypic antibodies.anti-idiotypic (anti-id) antibodies were raised in rabbits against five monoclonal antibodies (mabs) specific for different antigenic sites on the hemagglutinin (ha) of influenza virus mem71h-beln (h3n1) [a/memphis/1/71 (h3n2) x a/bel/42 (h1n1)]. each of the anti-id sera was directed predominantly towards a unique (private) idiotype of the immunizing mab, none of the five idiotypes being detectable in pooled balb/c antisera against mem71h-beln virus or on most other anti-ha mabs tested. partial ...19892470919
[antigenic drift of epidemic strains of influenza a virus (h3n2) in 1985].the study included 230 strains of influenza a (h3n2) virus isolated in the epidemic of 1985. a high degree of heterogeneity of the virus population was established with polyclonal sera, monoclonal antibodies and the method of krna-brna hybridization for the determination of the genome composition. among the strains of one epidemic (1985) three antigenically heterogenous groups of strains were detected similar with reference a/philippines/2/82, a/ken/1/84, and a/mississippi/1/85 strains. it was s ...19892471358
ultrastructure and some biological properties of influenza a virus. ii. effect of physico-chemical factors on influenza a virus and its interferonogenic properties.influenza virus a/ussr/053/74/h3n2 was subjected to the effect of some physico-chemical factors: freezing-thawing, ultrasounds, long-term storage at 4 degrees c, hydrogen ions, formaldehyde. all the preparations were tested for virus infectivity, hemagglutinin titer, neuraminidase activity and ability of altered viruses for interferon induction in vivo. the preparations whose viral particles preserved the activity of surface antigens and neuraminidase activity in particular, were able to induce ...19882471480
diversity of the class ii (i-ak/i-ek)-restricted t cell repertoire for influenza hemagglutinin and antigenic drift. six nonoverlapping epitopes on the ha1 subunit are defined by synthetic peptides.h-2k-restricted t cell clones derived from cba mice infected with x31 (h3n2) influenza virus, were shown to recognize distinct, nonoverlapping sequences within the ha1 subunit of the viral hemagglutinin (ha) using synthetic peptides. three i-ak-restricted t cell sequences were identified within ha1 68-83, 120-139, and 269-288, and two recognition sites presented in the context of the i-ek molecule were mapped to ha1 sequences 226-245 and 246-265. t cell clones specific for these regions of ha1 d ...19892474053
identification of pr8 m1 protein in influenza virus high-yield reassortants by m1-specific monoclonal antibodies.a panel of monoclonal antibodies to the m1 protein of a/pr8/34 (h1n1) (pr8) influenza a virus was found to distinguish in elisa high-yielding reassortant viruses derived from reassortment of pr8 and x-31 (h3n2) viruses with recently prevalent field strains of h1n1 or h3n2 subtype. these findings are concordant with results of genotyping that demonstrated the presence of pr8 rna 7 or m1 protein in high-yield reassortants by rna or protein page. all high-yield vaccine candidate reassortants applic ...19892474896
influenza virus infection and bacterial clearance in young adult and aged mice.the effects of influenza a/hong kong/68 (h3n2) virus infection on clearance of bacteria (staphylococcus aureus or serratia marcescens) from lungs of young adult (8-week-old) and aged (2-year-old) cba/2n mice were studied. no consistent differences in pulmonary bacterial clearance were observed in uninfected animals of either age group. however, both young and aged virus-infected mice consistently exhibited significantly reduced ability to clear challenge bacteria from their lungs compared to age ...19892475539
[correlation of antigenic properties of influenza viruses of the h3n2 subtype with changes in the amino acid sequence of hemagglutinins].the effect of amino acid substitutions within the antigenic sites, the residues close to these sites, and the other parts of the hemagglutinin molecule on cross-reactions between influenza subtype h3n2 virus strains in hemagglutination-inhibition tests are considered. previously we reported a method for calculation of the values of immunochemical cross-reactions between the homologous proteins based on the structural data. on this basis, a method for calculation of the titers of cross-reactions ...19892477951
ultrastructure and some biological properties of influenza a virus. iii. the role of influenza a virus lipids in interferon induction.experiments were carried out with a/ussr/053/74/h3n2 influenza virus. to remove lipids from virus particles, the enzyme phospholipase c, butanol-ether and the detergent cytylpyridinum chloride were used. mild treatment of the influenza virus with phospholipase c resulted in a slight decrease in the activity of both surface antigens of the virions as well as in a suppression of their infectivity. such virus is capable of ifn induction in mouse. long-term (25 h) treatment of the virus with phospho ...19882478101
ultrastructure and some biological properties of influenza a virus. iv. effect of proteolytic enzymes on viral particle.influenza virus strain a/ussr/053/74/h3n2 was subjected to the effect of soluble and nonsoluble trypsin. both enzymes appeared to affect the activity of neuraminidase. the viruses altered in this way did not induce interferon (ifn) in mice. treatment of viral particles with soluble bromeline brought about almost complete inactivation of hemagglutinin and slight suppression of neuraminidase activity. this virus was capable of ifn induction. on the other hand, when nonsoluble bromeline was used as ...19882478102
[protective action of cytotoxic lymphocytes depending on the antigenic determinant composition of influenza virus hemagglutinin].the protective role of cytotoxic lymphocytes (ctl) in dependence on composition of antigenic determinants of hemagglutinin of influenza viruses h3n2 was studied. it was established that ctl do not exert protective effect under conditions of adoptive transfer, when there is one common antigenic determinant in hemagglutinins of the virus forming immunity. when all antigenic determinants in hemagglutinins of influenza viruses are identical, ctl-like antibodies represent one of the main factors of a ...19892480826
[antigenic and biological properties of influenza a virus (h3n2), isolated and passaged in various systems--chick embryos and mdck cell culture]. 19892483782
human monoclonal antibodies to influenza virus: igg subclass and light chain distribution.three adults and three children were immunized with inactivated or live attenuated influenza vaccines and 98 igg monoclonal antibodies derived from ebv immortalization of their blood lymphocytes were studied. all antibodies reacted specifically with influenza a h3n2 or h1n1 whole virus and 73 of 74 tested reacted with the purified ha glycoproteins. the majority (76%) of 77 monoclonal antibodies adequately tested by elisa or solid phase ria contained lambda light chains. elisa analysis of the igg ...19892545224
[pathologic consequences of a severe influenza outbreak (swine virus a/h1n1) under natural conditions in the non-immune sow at the beginning of pregnancy].pathological consequences of a severe outbreak of swine influenza (h1n1 virus) in the non immune sow at the beginning of pregnancy, under natural conditions. a sudden acute outbreak of fever, depression, anorexia and coughing in a group of nulliparous sows from a herd that was currently under epidemiological investigation lead to build a particular disposal of observation. the clinical signs were daily recorded including rectal temperature. blood was taken from the sows at the beginning of the t ...19892550169
[the prevalence of antibodies to influenza virus and respiratory coronavirus in fattening pigs in spain].the presence of antibodies to two influenza viruses of the type a (h1n1 and h3n2) and to a porcine respiratory coronavirus was investigated in a study lasting a year. 735 blood serum samples were collected from 79 closed pig fattening farms in the province segovia (spain). hemagglutination inhibition was used with influenza viruses. the percentage of positive results was 78.5% and 62.5% respectively for the serotypes h1n1 and h3n2. a clear reduction in the spread of antibodies was observed in th ...19892554624
seroprevalence of porcine and human influenza a virus antibodies in pigs between 1986 and 1988 in hassia.1,268 sera collected from slaughtered pigs in hassia (frg) from 1986 to 1988 were tested for antibodies against porcine and human influenza a virus strains using the single radial haemolysis test (srht). antibodies against the porcine strains (subtype h1n1) a/swine/arnsberg/1/81, a/swine/iowa/15/30 and a/new jersey/7/76 were detected in 411 (32.4%), 318 (25.1%) and 304 (24.0%) of sera, respectively. up to 1988 a slight increase (10%) in the seroprevalence to a/swine/arnsberg/1/81 was noticed, wh ...19892559562
occurrence and aetiology of acute respiratory diseases: results of a longterm surveillance programme.totals of 58,661,000 acute respiratory disease (ard) cases, 1,376,651 bronchitis and pneumonia complications, and 93,042 deaths from influenza, bronchitis, pneumonia or chronic pulmonary affection were notified during 11 years of ard surveillance from 1975 to 1986. all ard seasons started with the first phase in september-december; this increase in morbidity was caused chiefly by adenoviruses, parainfluenza viruses, rhinoviruses and m. pneumoniae. second wave of ard morbidity occurring in januar ...19892565674
studies on the stability of t mutant of influenza virus.the t 30 degrees c mutant of a port chalmers 1/73 (h3n2) influenza virus passaged in cotton rats was reisolated. the original mutant and the reisolated virus were compared, the following parameters being tested: na activity, ha titer, sensitivity of na and ha to proteolytic enzymes, detergents and temperature, and michaelis constant of na. no differences were found in the parameters tested, thus suggesting that features of the mutant remained stable after passage in the susceptible animal organi ...19852579526
morphology and antigenicity studies on reassortant influenza (h3n2) viruses for use in inactivated vaccines.three influenza a (h3n2) reassortant whole virus vaccine strains with differing antibody-inducing capacities in hamsters were investigated morphologically and antigenically. although initial measurements of virion circumference, from electron micrographs of vaccine preparations, suggested a relationship of small virion size with low immunogenicity, subsequent immunization with, and morphological investigation of, vaccine virions separated on sucrose gradients, failed to obtain populations whose ...19852580887
[the use of the potentials of the molecular hybridization of nucleic acids as a method for the laboratory diagnosis of influenza in research on vaccinal infection].the data obtained as the result of the complex examination of volunteers immunized with live influenza vaccine, type a (h3n2), showed that the determination of the rna-containing structures by the method of the molecular hybridization of nucleic acids (mhna) was highly sensitive and reliable. this method proved to be more sensitive than common laboratory diagnostic tests (the isolation of the virus in chick embryos, the analysis of seroconversion, the antibody fluorescence test) and was not infe ...19892588878
epidemiological aspects of the evolution of influenza infections in a large urban centre (b.) in romania in 1988.the study describes the peculiarities of the influenza infection evolution, in 1988, in a large urban centre, b., in romania, as they result from the active surveillance of the epidemiological process of influenza and other viral respiratory tract infections, by means of a complex methodology based on clinical-epidemiological and laboratory techniques. the low endemic morbidity, the evolution of these seasonally ascendant specific incidence, the endemic aspect of influenza infection being mainta ...19892596018
[regularities of formation in a general population of serum antibodies to previously circulated influenza a viruses].the spectrum of antibody production against hemagglutinin of all known influenza a virus serotypes after influenza a (h3n2) infection in persons of all age groups (from 1 month to 72 years) was analysed to investigated the regularities of accumulation of antibodies against influenza a viruses gone out of circulation. for the same purpose, a long-term (many years) longitudinal analysis of serum anti-ha antibody levels against "old" influenza a (hsw1n1), a (h0n1), a (h1n1), a (h2n2), and a (h3n2) ...19892609640
[antigenic characteristics of influenza b virus strains isolated in an orphanage during an influenza outbreak in moscow in the winter of 1988].examinations of ard patients in an orphanage for defective children in moscow during an influenza outbreak in the winter of 1988 yielded 12 influenza virus strains, including 6 influenza b strains and 6 influenza a (h3n2) strains. the antigenic analysis of hemagglutinin of influenza b virus isolates showed that with respect to the b/leningrad/179/86 strain (an antigenic analogue of b/ann arbor/1/86 strain recommended for inclusion into the influenza vaccine for 1987-1988) they could be divided i ...19892609641
characterization of the m protein and nucleoprotein genes of an avian influenza a virus which are involved in host range restriction in monkeys.a reassortant virus possessing rna segment 7, which codes for the m1 and m2 proteins, of the avian influenza a/mallard/new york/6750/78 (h2n2) virus and the other seven rna segments of the human influenza a/udorn/307/72 (h3n2) virus had been shown previously to be markedly restricted in replication in the respiratory tract of squirrel monkeys. in contrast, a reassortant possessing segment 7 of another avian influenza virus, a/pintail/alberta/119/79 (h4n6), and the seven other rna segments from t ...19892609730
prevalence of antibody to current influenza virus strains in adolescents.during the spring of 1986, 118 pupils aged 15-18 years were surveyed for the presence of humoral antibodies to five influenza strains. prevalence of humoral immunity (hi) antibodies and immunity was found to be related to the year of the strain's emergence and to length of circulation time in the community. a high percentage of the adolescents were not immune to one or more of the tested strains. more than 40% of the studied group were not immune to the old a strains a/philipines 2/82 (h3n2) and ...19892621457
[heterogeneity of current epidemic influenza a viruses with respect to reproduction activity in a tissue culture].the reproduction activity in human embryo kidney cell culture (hek) of epidemic influenza a viruses (h3n2 serosubtype) isolated in different years and with a certain level of virulence for man was studied. the cells were inoculated with the viruses at a multiplicity of infection of 0.001 eid50/cell, and the reproductive activity was judged by the levels of infectious and hemagglutinating activity during 96 hours of observation. there was a clear-cut correlation between the virus virulence level ...19892633460
diagnosis of influenza a virus infections by detection of specific immunoglobulins m, a, and g in serum.the value of immunoglobulin m (igm) detection in the early diagnosis of influenza a was examined in a prospective study during an outbreak of influenza a/philippines/2/82 (h3n2) virus infection in february and march 1986. the igm response was investigated in sera from 64 adults with influenzalike symptoms; we found a fourfold rise in titer or high titers (greater than or equal to 80) of influenza a virus antibodies by the complement fixation test. the igm response, analyzed by the hemadsorption ...19892654180
recognition of the pb1, neuraminidase, and matrix proteins of influenza virus a/nt/60/68 by cytotoxic t lymphocytes.we have investigated the recognition of the pb1, neuraminidase, and matrix (m1) proteins of influenza virus a/nt/60/68 (h3n2 subtype) by secondary in vitro stimulated polyclonal cytotoxic t lymphocyte (ctl) populations. while these three proteins have different functions and cellular locations, they can all be recognized as target antigens. however, the immunogenicity of these proteins for ctls is under strict genetic control. thus, pb1 protein is recognized as a cross-reactive target antigen by ...19892658303
emergence and apparent transmission of rimantadine-resistant influenza a virus in families.to determine whether rimantadine can protect family members from acquiring influenza a viral illness and to assess the possible selection of drug-resistant strains of virus, we conducted a randomized, double-blind, placebo-controlled study in three communities during two influenza seasons. when influenza a occurred in a family, the members (including the index patient) were given either rimantadine (adult oral dose, 200 mg per day) or placebo for 10 days. the presence of illness was monitored by ...19892687687
natural or vaccine-induced antibody as a predictor of immunity in the face of natural challenge with influenza viruses.a study of influenza in residential schools provided the opportunity to assess the significance of antibody as a predictor of immunity. five hundred and fifty-six pupils from 8 schools were included in the investigations, and the outcome for these children in 27 naturally occurring outbreaks of influenza was analysed. the outbreaks comprised 5 caused by strains of influenza a h3n2, 10 caused by strains of influenza a h1n1, and 12 caused by strains of influenza b. on 8 occasions a second outbreak ...19892703026
effectiveness of influenza vaccine when given during an outbreak of influenza a/h3n2 in a nursing home.an explosive outbreak of influenza a/h3n2 began in a nursing home in the denver area early in november, 1987. residents had not been vaccinated at that time. vaccine was administered on november 11th. two weeks after the vaccine was given, the attack rate differed between the vaccinated and unvaccinated individuals. there were 40 cases of influenza among the 98 elderly residents, 12 cases of pneumonia, and seven deaths. vaccine efficacy two weeks after it was given was estimated to be 65.4% in p ...19892703638
effect of nitrogen dioxide exposure on susceptibility to influenza a virus infection in healthy adults.the effect of no2 exposure and human susceptibility to respiratory virus infection was investigated in a placebo-controlled, randomized, double-blind trial conducted in an environmentally controlled research chamber over 3 yr. healthy, nonsmoking, young adult volunteers who were seronegative to influenza a/korea/82 (h3n2) virus were randomly assigned to breathe either filtered clean air (control group) or no2 for 2 h/day for 3 consecutive days. the no2 concentrations were 2 ppm (year 1), 3 ppm ( ...19892712434
studies on the genetic basis of human influenza a virus adaptation to mice: degrees of virulence of reassortants with defined genetic content.a highly virulent mouse-adapted variant of influenza virus a/aichi/2/68 (h3n2) was crossed either with the original a/ussr/90/77 (h1n1) influenza virus strain or with its mouse-adapted, moderately mouse virulent variant. the reassortants were characterized with respect to their genetic content and pneumovirulence for mice. the reassortants fell into three categories: avirulent, highly virulent (resembling in this respect the parent a/aichi/2/68 virus) and moderately virulent (resembling the mous ...19892719553
pathways of evolution of influenza a (h1n1) viruses from 1977 to 1986 as determined by oligonucleotide mapping and sequencing studies.the evolutionary relationships of epidemic influenza a (h1n1) viruses isolated between 1982 and 1986 have been examined by oligonucleotide mapping and partial dna sequencing. the t1 mapping studies confirmed our previous report that the evolution of the influenza virus genome generally results in an average of four to six oligonucleotide changes per year. between 1982 and 1986, however, two apparent exceptions to this finding occurred. h1n1 antigenic variants (including the a/chile/83 and a/vict ...19892732691
mechanism of immunity to influenza: maternal and passive neonatal protection following immunization of adult ferrets with a live vaccinia-influenza virus haemagglutinin recombinant but not with recombinants containing other influenza virus proteins.neonatal ferrets are protected against infection with influenza virus by milk-derived anti-influenza virus igg after suckling on an immune mother. live vaccines protect better than killed vaccines despite their stimulation of lower maternal haemagglutination-inhibiting antibody levels. this suggests that antibody to virus proteins other than the haemagglutinin may also be involved. to investigate this, adult ferrets were immunized intradermally with live vaccinia-influenza virus recombinants eac ...19892732721
efficacy of rimantadine hydrochloride in the treatment of influenza infection of mice.rimantadine hcl was assessed for its effect on influenza a virus titer in lungs of infected balb/c mice. rimantadine administered orally via drinking water, with and without an intraperitoneal prophylactic loading dose, was compared to intraperitoneal administration. mice were infected with a non-lethal dose of influenza a/port chalmers/h3n2 virus and the pulmonary virus titers were determined at intervals over a 21 day period. prophylactic treatment with rimantadine followed by oral administrat ...19892735758
extensive heterogeneity in the hemagglutinin of egg-grown influenza viruses from different patients.we establish that the cultivation of influenza (h3n2) virus from any infected individual in chicken embryos (eggs) can result in the isolation of viruses with antigenic and/or structural heterogeneity in the hemagglutinin (ha) molecule. this variability contrasted sharply with the apparent lack of antigenic alterations in the ha of influenza viruses isolated from patients in madin darby canine kidney (mdck) cells. the most common subpopulation of egg-grown influenza viruses had the same phenotyp ...19892741346
[the structure of complex carbohydrate chains of hemagglutinin from influenza viruses a/kiev/59/79 (h1n1), a/chile/1/83/25(h1n1) and x/79(h3n2)].an earlier developed method of identification of oligosaccharides by hplc was used for studying the carbohydrate chains of three hemagglutinins from various influenza virus strains. the structures of main oligosaccharides of the complex type were elucidated on the basis of their chromatographic characteristics and monosaccharide composition. oligosaccharide patterns varied in the above hemagglutinin samples but in all cases the major complex chains were fucosylated and nonfucosylated biatennary ...19892742611
evaluation of cold-recombinant influenza a/korea (cr-59) virus vaccine in infants.twenty-four infants 5 to 13 months of age were intranasally vaccinated with a live cold-recombinant influenza a/korea (cr-59, h3n2) virus vaccine. nineteen infants served as controls. the inocula ranged from 10(3.2) to 10(6.2) 50% tissue culture infective doses (tcid50) per infant. zero of six, one of four, seven of ten, and four of four infants receiving 10(3.2), 10(4.2), 10(5.2), and 10(6.2) tcid50, respectively, were infected by the intranasal vaccine. the amount of virus required to infect 5 ...19892745699
control of influenza virus gene expression: quantitative analysis of each viral rna species in infected cells.we established a quantitative hybridization system by which three types of influenza virus rnas (vrna, mrna, and crna) for the 8 genome segments were measured individually. as the hybridization probes, 32p-labeled rnas of both plus and minus polarity were produced employing an sp-6 transcription system and used in a large molar excess, sufficient to overcome complementary rnas present in the viral rna samples. employing the system, we studied the control of the synthesis of each viral rna specie ...19892760014
efficacy of inactivated influenza a virus (h3n2) vaccines grown in mammalian cells or embryonated eggs.influenza virus (h3n2) host cell variants isolated from a single infected individual were compared for their protective efficacies when used as formalin-inactivated purified whole virus vaccines in ferrets. a/mem/12/85 virus grown in embryonated chicken eggs (egg-grown), which differs from a/mem/12/85 grown in mammalian madin-darby canine kidney cells (mdck-grown) by a single amino acid substitution in the hemagglutinin molecule, was shown to be distinguishable by immune ferret serum. ferrets we ...19892760480
biological and genetic evolution of the nucleoprotein gene of human influenza a viruses.there is a significant difference in the ability of human influenza a virus h1n1 strains isolated up to 1977 and those isolated later to rescue temperature-sensitive mutants of fowl plague virus with a defect in the nucleoprotein (np) gene. therefore the np genes of five human h1n1 and h3n2 influenza a virus strains, isolated between 1950 and 1978, have been sequenced. by comparison with previous and more recent isolates, an evolutionary pathway has been established. three amino acid replacement ...19892769232
serological evidence for influenza virus activity in nigeria (1985-1987).a study to determine the activity of influenza virus among the children population was undertaken between 1985 and 1987 in nigeria. paired sera were obtained from children presenting with respiratory diseases at the children emergency and outpatient clinics of the university college hospital, ibadan. forty-two paired sera were examined by haemagglutination-inhibition test to determine hi antibody level of the patients to different serotypes of influenza virus. ninety percent of the children show ...19892773309
molecular cloning and sequencing of influenza virus a/victoria/3/75 polymerase genes: sequence evolution and prediction of possible functional domains.the influenza virus a/victoria/3/75 (h3n2) polymerase genes encoding pb1, pb2 and pa have been cloned by cdna synthesis and insertion into bacterial vectors. the complete sequence for each polymerase gene has been obtained from random m13 subclones and compared to other influenza virus polymerase genes. a total of 45, 74 and 78 nucleotide changes were fixed in the period 1968-1975, corresponding to 10, 12 and 9 amino acid changes, for pb1, pb2 and pa genes, respectively. the amino acid sequence ...19892773594
sequence of the nucleoprotein (np) gene of the influenza a virus reassortant 81/ho, carrying the np originally derived from a/hong kong/1/68 (h3n2). 19892780295
enhancement of protective antibody responses by cholera toxin b subunit inoculated intranasally with influenza vaccine.effects of the b subunit of cholera toxin (ctb) on the primary antibody responses to influenza virus a/pr/8/34 (pr-8) (h1n1) ha vaccine and on protection against viral challenge were investigated in balb/c mice which were immunized intranasally with both the vaccine and ctb. the dose of ctb (greater than or equal to 1 microgram) inoculated with the vaccine (greater than or equal to 0.15 microgram) induced high responses of both antiviral iga antibodies in the nasal wash and haemagglutinin-inhibi ...19892781859
the influence of hiv infection on antibody responses to a two-dose regimen of influenza vaccine.we studied whether a two-dose regimen of inactivated influenza virus vaccine was more effective than a single dose in inducing protective hemagglutination-inhibition antibody responses in patients infected with human immunodeficiency virus (hiv). participants included subjects with acquired immunodeficiency syndrome, subjects with acquired immunodeficiency syndrome-related complex, and hiv-seropositive individuals with either lymphadenopathy only or no symptoms. control subjects were hiv-seroneg ...19892787416
avian-to-human transmission of the pb1 gene of influenza a viruses in the 1957 and 1968 pandemics.we determined the origin and evolutionary pathways of the pb1 genes of influenza a viruses responsible for the 1957 and 1968 human pandemics and obtained information on the variable or conserved region of the pb1 protein. the evolutionary tree constructed from nucleotide sequences suggested the following: (i) the pb1 gene of the 1957 human pandemic strain, a/singapore/1/57 (h2n2), was probably introduced from avian species and was maintained in humans until 1968; (ii) in the 1968 pandemic strain ...19892795713
evolutionary pathways of the pa genes of influenza a viruses.nucleotide sequences of the pa genes of influenza a viruses, isolated from a variety of host species, were analyzed to determine the evolutionary pathways of these genes and the host specificity of the genes. results of maximum parsimony analysis of the nucleotide sequences indicate at least five lineages for the pa genes. those from human strains represent a single lineage, whereas the avian genes appear to have evolved as two lineages--one comprising genes from many kinds of birds (e.g., chick ...19892800339
[the change in functional activity and primary structure of the m2 protein in variants of the influenza virus resistant to remantadine and deitiforin: common and individual differences from the original strain].the two variants of influenza a/victoria/35/72 (h3n2) virus resistant simultaneously to remantadine, deitiforin, adapromine and amantadine were obtained while passaging the virus in presence of remantadine or deitiforin. both variants differed from the parental strain in optimal ph for hemolysis, transcriptase activity and in amino acid sequence of m2 protein. maximal hemolytic activity of the parental strain is registered at ph 5.2, for the variants cultured in the presence of remantadine or de ...19892811900
protection against influenza virus infection by a two-dose regimen of nasal vaccination using vaccines combined with cholera toxin b subunit.the effectiveness of the two-dose regimen, composed of a primary intranasal inoculation of influenza a-type virus ha vaccine together with b subunit of cholera toxin (ctb) and the subsequent intranasal inoculation of vaccine alone 4 weeks later, was examined. in mice given a relatively high dose of virus a/pr/8/34 (pr-8, h1n1) ha vaccine (1.5 micrograms) both as a primary antigen with ctb (1 microgram) and as the second antigen, the secondary responses of both antiviral iga antibodies in nasal w ...19892815967
outbreaks of classical swine influenza in pigs in england in 1986.serum samples from pig herds in great britain have been examined for antibodies to influenza virus since 1968. antibodies to h3n2 virus strains have been found since 1968 and the serological data presented here suggests that h3n2 virus strains continue to persist in the pig population. an outbreak of acute respiratory disease occurred in a 400-sow unit. the outbreak was characterised by coughing, anorexia, fever, inappetence and loss of condition. the gilts and weaners were affected and the morb ...19872820111
isolation of human (h3n2) influenza virus and prevalence of the virus-antibody in swine. 19872828738
passive serum antibody causes temporary recovery from influenza virus infection of the nose, trachea and lung of nude mice.balb/c normal and nude mice were infected with a non-lethal mouse-passaged a/pc/1/73 (h3n2) influenza virus in order to assess the role of t cells on the course of disease of the nose, trachea and lung. the tracheal epithelium of both mouse strains was desquamated by 3 days after infection. although normal regeneration began, nude mice never completed that regeneration whereas normal mice had fully regenerated tracheas by day 14. this failure to complete the recovery was also evident from the co ...19882832312
porcine influenza outbreak in east anglia due to influenza a virus (h3n2) 19872832998
characterization of an influenza a (h3n2) virus isolated from pigs in england in 1987. 19882838122
identification of h3n2 influenza virus isolated from pigs with respiratory problems in spain. 19882839928
high-level transient expression of influenza virus proteins from a series of sv40 late and early replacement vectors.we have constructed a collection of simian virus 40 (sv40) plasmid vectors useful for transient or constitutive expression of cdna or genomic dna in animal cells. most vectors contain several unique restriction sites downstream from the sv40 late or early promoter, and are available with or without the virus-specific splicing signals. the use of these vectors for transient expression in monkey cells of x47 (h3n2) influenza hemagglutinin (ha) and matrix protein (m1) was demonstrated. membrane-bou ...19882844629
gamma-irradiated influenza a virus can prime for a cross-reactive and cross-protective immune response against influenza a viruses.a-strain influenza virus a/jap (h2n2) was tested for its ability to induce cytotoxic t cells (tc) after being rendered non-infectious by either uv or gamma irradiation. gamma-irradiated virus proved to be more efficient than uv-inactivated virus in priming for a memory tc cell response or in boosting memory spleen cells in vitro. most importantly, gamma-inactivated, but not uv-inactivated, a/jap immunized animals survived lethal challenge with heterologous (a/pc(h3n2), a/wsn(h1n1)) virus as effe ...19882846435
prophylactic and therapeutic effects of murabutide in of1 mice infected with influenza a/h3n2 (a/texas/1/77) virus.the antiviral activity of a novel biological response modifier (murabutide mdp derivative) has been investigated in 3-week-old of1 mice infected with influenza (a/texas/1/77) virus. in each experimental and control group, 10 mice were infected intranasally with a viral dose producing 50% mortality in 5 days and received murabutide via the subcutaneous or intranasal route at various doses either in a simple or in daily repeated administration. all experiments were done in triplicate. significant ...19882851033
influenza in swine in belgium (1969-1986): epizootiologic aspects.from 1984 until 1986, influenza isolates were obtained from 59 outbreaks of respiratory tract disease in belgium. in 21 of the outbreaks, h3n2-influenza virus isolates, related to the human a/port chalmers/1/73 strain were obtained. all other isolates were h1n1-influenza virus strains. the prevalence of variants of the human h3n2-influenza virus in the belgium swine population was determined by examining sow sera which had been collected between 1969 and 1984. the results of this serological stu ...19882851410
detection of type a and b influenza viruses in clinical materials by immunoelectronmicroscopy.direct immunoelectronmicroscopy (iem) was used for detecting influenza subtype a(h1n1), a(h3n2) and type b viruses in nasopharyngeal washings or swabs collected during three consecutive periods of enhanced influenza incidence. virus identification was performed with immune rat sera and in the case of the a(h3n2) subtype also with convalescent human sera. in all the materials examined influenza virus was demonstrated by isolation in chick embryos or by immunofluorescence in infected tissue cultur ...19852859758
antibodies to new variants of subtype a(h3 n2) influenza virus in pigs.following an explosive epidemic of a(h3n2) influenza among the human population of czechoslovakia in 1983, haemagglutination-inhibiting antibodies (titre range 10-640) against strains a/texas/77, a/bangkok/79 and a/philipines 2/83 were detected in 93% of sera collected from 135 pigs on three farms. only 6.6% of sera were negative. anti-neuraminidase antibodies were detected at rates of 81% and 23% in two and one of the herds, respectively. antibodies against a/rnp were demonstrated by the immuno ...19852860799
subunit influenza virus vaccine grippovac se-azh (vaccination of adults).grippovac se-azh a polytype, subunit influenza virus vaccine containing h1n1 and h3n2 influenza a virus strains and one influenza b virus strain has been tested in 80 volunteers. the trials demonstrated the harmlessness, the absence of adverse reactions, and except of the b type, the high antigenicity of vaccine preparation when administered in two injections. the optimal dose of each viral strain haemagglutinin (ha) was 15 micrograms in 0.5 ml.19852864825
monoclonal antibodies for the rapid diagnosis of influenza a and b virus infections by immunofluorescence.mouse monoclonal antibodies, directed against antigenic sites on influenza a and b viruses and found to be type-specific in an immunoassay, were assessed for use as diagnostic reagents in an indirect immunofluorescence assay on nasopharyngeal secretions. the influenza a antibodies were directed against nucleoprotein or matrix protein antigens and the influenza b antibodies against nucleoprotein and haemagglutinin antigens. the influenza a anti-matrix monoclonal antibody was found to give a stron ...19852865418
the variability of genes of influenza a (h3n2) virus strains isolated in the g.d.r. during the 1970-1978 epidemic seasons.gene variability of all influenza a virus strains (h3n2) isolated in the g.d.r. during the epidemic seasons of 1970-1978 was investigated by crna:vrna hybridization. from 1970 through 1975 a gradual smooth variability of the majority of genes and moderate heterogeneity in gene homology of the isolates were observed. from 1975 through 1977 the genome variability was more profound and the isolates differed from one another in gene homology. in 1978 the variability became less pronounced again. qua ...19852869657
allantoic fluid protease activity during influenza virus infection.neutral protease activity of allantoic fluid from embryonated chicken eggs was quantified during the course of influenza virus infection. antigenic subtypes of influenza a viruses selected for study were h1n1 strains pr/8/34, brazil/8/78, fm/1/47, the h3n2 strain bangkok/1/80 and the h5n9 turkey/ /ontario/66 as well as the sendai strain of parainfluenza type 1 virus. three different types of profiles of allantoic fluid proteases could be readily distinguished after infection of eggs with various ...19862873727
characterization of the reproduction of influenza a epidemic viruses in cell cultures.two influenza a epidemic viruses with different indices of virulence for humans have been compared with respect to their reproduction in human embryo kidney (hek), human embryo lung (hel), and chick embryo kidney (cek) cell cultures. it has been shown that the highly virulent for humans a/victoria/35/72 (h3n2) strain reproduced intensively in hek and hel cells irrespective of the inoculated dose (multiplicity of infection = 1 eid50 per cell and of 0.001 eid50 per cell, respectively). efficient i ...19862873731
variation of influenza a (h3n2) viruses isolated in the g.d.r. during 1969-1980 epidemics.a collection of 39 influenza a virus strains of the subtype h3n2 isolated in g.d.r. and of six reference strains were analysed with regard to the antigenic structure of their surface proteins haemagglutinin (ha) and neuraminidase (na) as well as regarding their polypeptide variations. for the field strains during the drift period from spring 1969 to spring 1980 seven main variations resulted from eight polyclonal sera with the haemagglutination inhibition test, and five main variations from six ...19862874720
characterization of influenza a-1983 epidemic strains by polyclonal and monoclonal antibodies and detection of two co-circulating antigenic variants.influenza virus strains isolated during 1985 epidemic in czechoslovakia proved to be antigenically closely related to a/bangkok/79, a/philippines/2/83 and a/texas/77 (all h3n2) viruses, if examined in haemagglutination inhibition (hi) tests with standard polyclonal antisera. if examined in hi tests with monoclonal antibody (mab) iib4, the virus isolates could be separated into two groups: those reacting to high titres (about two thirds of the isolates) and those negative with iib4 (titre of less ...19862874726
a simple and rapid characterization of influenza virus isolates by monoclonal antibodies in radioimmunoassay.radioimmunoassay (ria) with infectious allantoic fluid directly bound to solid phase, suitable for detection and further characterization of influenza virus isolates, is described. this simple and rapid method was applied for description of isolates obtained from different regions of czechoslovakia during influenza epidemic in 1983. the results confirmed that all 13 examined isolates represent influenza a viruses possessing h3 subtype haemagglutinin very similar to haemagglutinin of influenza vi ...19862874733
studies on influenza-virus virulence in recombinants between epidemic and vaccine strains.influenza virus recombinants between epidemic strains a/brazil/11/78 (h1n1), a/ussr/382/78 (h3n2) and vaccine strains a/leningrad/9/46 (h1n1), a/victoria/35/72/50 (h3n2) have been tested for virulence for humans and albino mice; their genome structure has also been determined. it has been shown that after the replacement of surface antigens of a/leningrad/9/46 (h1n1) strain by surface antigens of a/brazil/11/78 (h1n1) or a/ussr/382/78 (h3n2), strains, the virus becomes totally nonpathogenic for ...19872891277
clinical and morphologic studies on the guinea pig eye infected with human influenza virus strains of different virulence.human influenza virus serotypes h3n2 and h2n2 caused iridocyclitis and uveitis when inoculated at does of 10(6) 6.5 eid50 into the guinea pig eye anterior chamber. virulent influenza virus strains and their attenuated variants prepared by passaging in chick embryos (ce) have been compared in this model. these studies showed that virulent viruses cause more severe damage in the eyes than the attenuated strains.19872892383
simultaneous determination of the level of antibodies to influenza virus surface and internal proteins by enzyme-linked immunosorbent assay.enzyme-linked immunosorbent assay (elisa) has been adopted for simultaneous determination of the levels of antibodies to different influenza virus proteins in human sera with known haemagglutination-inhibition (hi) titre. whole virus of serotypes h1n1 and h3n2, haemagglutinin (ha), matrix (m) and nucleoprotein (np) proteins have been used as antigens. for detection of antibodies bound to the antigen, peroxidase labelled staphylococcus protein a conjugate has been used. correlation of the elisa a ...19882899957
resistance of mice to reinfection after e-aminocaproic acid treatment of primary influenza virus infection.the effect of proteolysis inhibitors on the formation of resistance to virus challenge has been studied in experimental influenza of mice. e-aminocaproic acid (e-aca) when used in the treatment of influenza decreased the virus reproduction in lungs and also enhanced the humoral immune response. the antibody titre on days 14 to 21 post infection (p.i.) was significantly higher in the treated animals. on day 30 after challenge with the homologous strain (h3n2) the virus reproduced to low levels in ...19882899958
clinico-immunologic and allergologic studies with the inactivated influenza virus vaccine purified and concentrated by gradient centrifugation.vaccination activity and safety of inactivated influenza centrifugal divaccine have been studied in groups of subjects aged 18 to 22, 15 to 16, and 9 to 14 years. the vaccine tested contained either a standard dose (6-8 micrograms) or double a dose (12-16 micrograms) of the haemagglutinin (ha) of influenza viruses a(h1n1) and a(h3n2). the double antigenic load of the vaccine did not enhance its reactogenicity for adults or adolescents aged 15 to 16 years. it enhanced, however, the production of ...19882906221
action of epsilon-aminocaproic acid on the proteolysis system during experimental influenza in mice.proteolysis system was examined in influenza-virus-infected mice after a 5-day course of therapeutic or preventive treatments with the proteolysis inhibitor epsilon-aminocaproic acid (e-aca). the mice were infected with nonadapted influenza virus a/hong kong/1/68 (h3n2). e-aca was shown to exert a pathogenetic action expressed by a marked tendency to normalization of elevated alkaline protease activity in damaged lung tissue and in the blood of infected animals. e-aca induced a long-lasting high ...19882906223
comparison of the virologic and immunologic responses of volunteers to live avian-human influenza a h3n2 reassortant virus vaccines derived from two different avian influenza virus donors.we compared the abilities of the six internal rna segments of two avian influenza viruses, a/mallard/alberta/88/76 (h3n8) and a/mallard/ny/6750/78 (h2n2), to confer attenuation on wild-type human influenza a/bethesda/1/85 (h3n2) virus in seronegative adult volunteers. live avian-human influenza a reassortant virus vaccines derived from either avian virus parent were comparable in the following properties: safety, infectivity, immunogenicity, and genetic stability. since the avian influenza a/mal ...19892913033
resistance of influenza a virus to amantadine and rimantadine: results of one decade of surveillance.all clinical isolates of influenza a viruses from patients in huntington, west virginia, during the decade 1978-1988 were tested, and 65 of 65 h1n1 and 176 of 181 h3n2 viruses were susceptible to the antiviral action of amantadine and rimantadine. the five resistant viruses were obtained from three members of a family undergoing therapy or prophylaxis with rimantadine. resistant influenza emerged during treatment with rimantadine and spread to two family contacts, causing typical influenza with ...19892915166
purified influenza virus hemagglutinin and neuraminidase are equivalent in stimulation of antibody response but induce contrasting types of immunity to infection.balb/c mice immunized with graded doses of chromatographically purified hemagglutinin (ha) and neuraminidase (na) antigens derived from a/hong kong/1/68 (h3n2) influenza virus demonstrated equivalent responses when ha-specific and na-specific serum antibodies were measured by enzyme-linked immunosorbent assays (elisas). antibody responses measured by hemagglutination inhibition or neuraminidase inhibition titrations showed similar kinetic patterns, except for more rapid decline in hemagglutinati ...19892915381
[specific and nonspecific indicators of activation of influenza viruses before an epidemic caused by influenza viruses subtype a/h3n2 and type b in czechoslovakia in 1986].the authors submit an aetiological and epidemiological analysis of the influenza epidemic which occurred in the csr between the 4th and 14th week of 1986 and was caused by the influenza virus subtype a/h3n2/ and type b. the epidemic affected a total of 27.1% of the population, in the age group of 0-5 years 63.7%, in the age group 6-14 years 52.7% and in the age group above 15 years 17.1%. in the course of the epidemic 77,458 cases of pneumonia and bronchitis were reported and 1,412 deaths with t ...19892920398
occupational exposure to influenza--introduction of an index case to a hospital.the epidemiology of influenza in the hospital is frequently confounded by failure to separate community-acquired from nosocomial transmission. an 83-year-old woman was hospitalized one day after returning from asia with complications resulting from acute influenza a (h3n2) infection; she was the first culture-confirmed case in the region during the 1987-1988 influenza season, and her illness antedated other influenza cases in the area by at least four weeks. the patient shed virus at least four ...19892926107
location of influenza virus m, np and ns1 proteins in microinjected cells.when microinjected as cloned dna, the nucleoprotein (np) of influenza virus a/nt/60/68 (h3n2) accumulated in the nuclei of xenopus laevis oocytes, and cultured cells of rodent and primate origin. this accumulation appeared to be specific and a property of the np itself (or conceivably np in association with unknown cellular constituents) since no other influenza virus components were present in dna-injected cells. in the oocyte nucleus, clonally derived np achieved an eightfold concentration ove ...19852932535
[virological and pathomorphological study of an influenzal infection in children 1982-1983].in the interepidemic period of 1982-1983, acute respiratory viral infections and pneumonias in infants in alma-ata were in 40.2% of cases etiologically associated with influenza infection. in the studied period in alma-ata and during an epidemic outbreak of influenza in kzyl-orda (march, 1983), two influenza a virus subtypes, h1n1 and h3n2, were in circulation. in a number of cases these subtypes were isolated from the same infants.19852932855
suicide selection of murine t helper clones specific for variable regions of the influenza hemagglutinin molecule.a negative selection procedure has been developed to obtain murine t helper clones specific for variable regions of the influenza a hemagglutinin. t cell lines, established from mice primed by intranasal infection with x31 (h3n2) virus, were cross-stimulated with natural variant viruses of known primary sequence (either a/texas/1/77 or a/eng878/69) and proliferating cells eliminated by treatment with the cell cycle-specific drug 5-bromodeoxyuridine. after two suicide cycles, t cell lines were su ...19862941307
[influenza morbidity in the kazakh ssr 1977-1984].in 1977-1984, 6 epidemic outbreaks of influenza were recorded in the republic of which 2 were due to influenza a (h1n1), 2 to a (h3n2) and 2 to influenza b virus. the epidemics of influenza h1n1 (1977-1978, 1981) and h3n3 (1979-1980, 1983) were characterized by gradual decrease of their intensity as manifested by lowering of the morbidity rate and frequency of virus isolation. on the contrary, epidemics of influenza b showed a certain trend to increase. an important feature of the epidemics etio ...19862945325
immunologic response to influenza virus neuraminidase is influenced by prior experience with the associated viral hemagglutinin. iii. reduced generation of neuraminidase-specific helper t cells in hemagglutinin-primed mice.in balb/c mice primed by influenza virus infection to h3 hemagglutinin and n2 neuraminidase, presentation of n2 in association with a heterosubtypic (h7) hemagglutinin results in production of a greater amount of n2 antibody than is found with homologous (h3n2) reimmunization. titration of primed helper t cell (th) activity by adoptive transfer of purified t cells to athymic mice given h6n2 vaccine demonstrates a lesser number of n2-specific th cells in mice subjected to homologous reimmunizatio ...19872957444
antigen-presenting b cells and helper t cells cooperatively mediate intravirionic antigenic competition between influenza a virus surface glycoproteins.parenteral vaccination of balb/c mice primed by infection with h3n2 variants of influenza a virus results in a reduced production of n2 antibody in response to homologous (h3n2) vaccine compared with the response to an h7n2 vaccine equal in n2 immunologenicity. we now have studied the interaction in vitro of purified splenic b and t lymphocytes from variably immunized mice to ascertain the cellular basis of the hemagglutinin (ha)-influenced antibody response to neuraminidase (na). assay of the p ...19872958849
specific antibody responses by high- and low-density human peripheral blood b cells: t-helper cells and t-cell replacing factor (trf) act on different b-cell subpopulations.antibody production to influenza a strain virus x31 (h3n2) was measured in cultures of peripheral blood mononuclear cells (pbmc) stimulated with either antigen (x31) or pokeweed mitogen (pwm). with some donors, x31 antibody was produced in response to antigenic stimulation, but not as part of the polyclonal response to pwm, suggesting that antigen and pwm may be acting on different b-cell subpopulations. to test this hypothesis, t-cell depleted pbmc (e-) cells were fractionated on discontinuous ...19872959615
[biological characteristics of epidemic and interepidemic strains of the influenza a (h3n2) virus].comparative studies of biological properties of influenza a (h3n2) viruses isolated in the epidemics of 1980 and 1983 and in the interepidemic period of 1982 showed a sharp reduction of the biological activity of the interepidemic viruses as compared with that of the epidemic ones. this was manifested by low isolation rate of virus in the interepidemic period, reduced hemagglutinating, interfering, and immunogenic activity of these viruses, poor reproduction in the lung tissue of white mice and ...19872963436
the influence of human immunodeficiency virus (hiv) infection on antibody responses to influenza vaccines.to ascertain whether subjects infected with human immunodeficiency virus (hiv) generally develop protective hemagglutination inhibition antibody responses to inactivated influenza vaccines.19882970238
identification of sequence changes in the cold-adapted, live attenuated influenza vaccine strain, a/ann arbor/6/60 (h2n2).nucleotide sequences have been obtained for rna segments encoding the pb2, pb1, pa, np, m1, m2, ns1, and ns2 proteins of the influenza a/ann arbor/6/60 (h2n2) wild-type (wt) virus and its cold-adapted (ca) derivative that has been used for preparing investigational live attenuated vaccines. twenty-four nucleotide differences between the ca and wt viruses were detected, of which 11 were deduced to code for amino acid substitutions in the ca virus proteins. one amino acid substitution each was pre ...19882974219
detection of viral and chlamydial antigens in open-lung biopsy specimens.the recovery of viruses and chlamydia trachomatis from cell cultures and the detection of their antigens in impression smears prepared from open-lung biopsy (olb) specimens from immunocompromised adults were compared. touch impression smears were prepared on three slides, each containing eight wells. olb tissue was homogenized (stomacher) and inoculated into mrc-5, primary monkey kidney, and mccoy cell cultures. the direct and indirect immunofluorescence (if) tests were used to detect antigens t ...19852983526
clinical-histopathological correlations in experimental otitis media: implications for silent otitis media in humans.clinical-histopathological correlations were sought in an experimental animal model of otitis media. among 20 chinchillas inoculated intranasally with wildtype influenza a/alaska virus (h3n2) and type 7f streptococcus pneumoniae, 15 animals (18 ears) developed otoscopic and tympanometric signs of otitis media with middle ear effusion. middle ear inflammation was most intense 10 days after virus inoculation. twenty-two days after virus inoculation, eight ears showed diffuse middle ear histopathol ...19852987783
epidemiological features of influenza in a large town of romania during 1983.data supplied by the active influenza surveillance - including clinical, epidemiological and laboratory investigations - allowed the characterization of the particularities of an influenza outbreak caused by a(h3n2) virus in a large town of romania in march 1983. the epidemiological impact of influenza in 1983 is discussed in the light of the complex relationships between the antigenic structure of circulating influenza strains and the profile of antiinfluenza immunity of the population.19852988190
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