| electrophoretic separation and characterization of subunits released from influenza virus by detergents. | subunits released from influenza a/singapore/1/57 (h2n2) virus by either triton-x-100 (t-x-100); or sodium lauryl sarcosinate (sls) or ether were separated by electrophoresis in agarose suspension into a rapidly migrating fraction (i) and a slowly migrating fraction (ii). fraction i obtained after t-x-100 treatment contained the viral ribonucleoprotein (rnp) in a form indistinguishable from the obtained after ether treatment. sls treatment of the virus resulted in a rapidly migrating fraction co ... | 1976 | 7935 |
| influenza virus antigens in human leukocytes after oral administration of live tissue culture influenza a monovaccine. | influenza a virus antigens were detected in leukocytes by immunofluorescence. after intravenous inoculation of the a/moscow/16/65 (h2n2) vaccine strain to chickens, cytoplasmic antigens of the virus were observed in mononuclear leukocytes from 24 to 72 hours post inoculation (p.i.). the course of antigen detectability was similar after two repeated inoculations of the virus. after oral vaccination of human volunteers with a live tissue culture influenza a monovaccine from the x-47 (h3n2) recombi ... | 1977 | 22233 |
| marked difference in electrophoretic migration rates between two influenza a viruses. | comparative moving boundary electrophoresis revealed that influenza virus a/pr/8/34 (h0n1) has a 2.5 times higher electrophoretic migration rate at ph 7 than influenza virus a/singpore/1/57 (h2n2). this difference was the same whether the compared viruses were purified first by either ammonium sulphate precipitation or adsorption onto and elution from red blood cells and then by density gradient centrifugation. the same electrophoretic methods was used for testing the homogeneity of influenza vi ... | 1978 | 27965 |
| [age profile of the antihemagglutinins and antineuraminidase antibodies in type a influenza (author's transl)]. | antineuraminidase and antihemagglutinating antibody studies were carried out in parallel in sera from subjects born in bulgaria in 1968-1972, 1956-1960, 1946-1950, 1925-1935 and 1917-1920. it was found that the amount of both antineuraminidase and antihemagglutinating antibody in sera from normal subjects could vary depending upon the year of birth and the strain used for the test. the antibody spectrum was most narrow in children under 4 and wider in subjects born before 1925. serograms of the ... | 1975 | 54996 |
| influenza a virus interaction with murine lymphocytes. i. the influence of influenza virus a/japan 305 (h2n2) on the pattern of migration of recirculating lymphocytes. | the effect of influenza virus a/japan 305 (h2n2) on the path of migration of recirculating lymphocytes has been studied. 51cr-labeled rat thoracic duct lymphocytes (tdl) were incubated with virus at 37 degrees c for 1 hr and then infused i.v. into syngeneic recipients which were killed 1 hr later. virus-treated tdl accumulated in the liver and their recovery in lymph nodes and spleen was severely reduced. changes in lymphocytes induced by virus developed rapidly and were evident after incubation ... | 1976 | 60451 |
| [antigenic characteristics of chicken influenza viruses]. | data on isolation of chicken influenza virus strains in this country during epizootics in 1970--1975 are presented, and the antigenic characteristics of the isolates are described. all the strains had a mixed hemagglutinin type (gp6-h3n2) and neuraminidase h2. neuraminidase of the strains had more marked antigenic relationship with h2 human influenza a/singapore/57 (h2n2) virus than h2 of other human influenza virus strains. the size of km of neuraminidase is similar in all chicken influenza vir ... | 1976 | 62456 |
| antigenic variants of influenza a virus obtained in vitro. | the aim of this study was to investigate antigenic "drift" in the haemagglutinin and neuraminidase antigens of influenza a virus in vitro under immunological pressure. variants of the "asian" influenza strains a/england/12/64 (h2n2) and a/tokyo/3/67 (h2n2) were isolated in the allantois-on-shell system in the presence of homologous postinfection ferret sera. for each of these two viruses three generations of variants were isolated and characterized. it was found that the successive antigenic var ... | 1976 | 62624 |
| [electrophoretic mobility of polypeptides in different strains on human influenza a and b viruses]. | the method of electrophoresis in a single polyacrylamide gel plate was used for comparative study on virion polypeptides mobility in human influenza a and b virus strains. molecular masses of individual polypeptides and their portion in the virion were determined. no variations in the migration speed of nucleoprotein (np) and membrane protein (mp) were found in strains belonging to the same genus, but there were differences in the migration speed of these proteins in the genus a and genus b. sig ... | 1978 | 80885 |
| a duck influenza virus with haemagglutinin related to that of a/singapore/57 (h2n2) virus. | | 1975 | 239585 |
| the relative potencies of anti-influenza compounds. | the relative potencies of some standard anti-influenza compounds have been examined in vitro by plaque reduction in calf kidney cells, and in vivo by reduction in virus titers of the lungs of infected mice. strains belonging to the four subtypes h0n1, h1n1, h2n2, and h3n2 were employed to compare the activity of amantadine hydrochloride and ribavirin. in vitro for all strains except a/nws/oo(h0n1) amantadine hydrochloride was 3-4 times more active than ribavirin. in vivo with sensitive strains a ... | 1977 | 280137 |
| effect of an interferon inducer, 9-methylstreptimidone, on influenza virus infection in mice. | the antiviral effect of 9-ms was examined in mice infected with mouse-adapted influenza a2 (h2n2) virus. either a single or a continuous prophylactic administration of 9-ms protected mice from virus infection, and comparison of the minimal effective dose with the lethal dose gave a therapeutic index of approximately 60. when the treatment was started after infection, however, no antiviral effect was demonstrated. a potent virus-inhibitory factor was detected in the lung and serum after a single ... | 1977 | 280155 |
| influenza a viruses of the h2n2 subtype are lymphocyte mitogens. | | 1978 | 305001 |
| influenza virus: appearance of high mouse-neurovirulent recombinants. | recombinants from two influenza a strains that lacked mouse neurovirulence were tested, along with their parent strains, for mouse neurovirulence and for the ability to propagate in dissociated mouse embryo brain cells. the parents used were (i) strain a/rostock/34 (fpv) (hav1n1), with a high chicken neurovirulence, and (ii) the mouse-lung-adapted human strain engl/1/61 (h2n2), lacking neurovirulence. in some of the recombinants high mouse neurovirulence could be detected after intracerebral ino ... | 1979 | 429139 |
| nucleotide sequence coding for the "signal peptide" and n terminus of the hemagglutinin from an asian (h2n2) strain of influenza virus. | | 1979 | 473601 |
| investigation of recombinants of human influenza and fowl plague viruses. | recombinants of human influenza type a viruses, a/krasnodar/101/1959 (h2n2) or a/habarovsk/15/1976 (h3n2), and fowl plague virus (fpv), strain weybridge (hav1neq1) were obtained. the genome of the recombinant obtained by recombination of influenza a/habarovsk/15/1976 virus and fpv contained the genes 4 (ha) and 6 (na) derived from the influenza a/habarovsk virus and all the other genes [1, 2, 3, 5 (np), 7 (m), 8 (ns)] from fpv. the genome of the recombinant of a/krasnodar/101/1959 virus and fpv ... | 1979 | 479841 |
| comparisons of virulence of influenza virus recombinants in ferrets in relation to their behaviour in man and their genetic constitution. | two parent viruses, a/finland/4/74(h3n2) and a/okuda/57(h2n2), virulent and attenuated respectively for man, showed similar differences of virulence in ferrets as judged by estimations of 50% minimal infectious doses (mid50), the level and persistence of nasal infection, the height and duration of pyrexia and the level of lung infection. in ferrets, two recombinant clones, wrl 94(h3n2) and wrl 105(h3n2), were almost as virulent as a/finland and indistinguishable from one another, a result which ... | 1979 | 501338 |
| description of a technique for the analysis of antineuraminidase antibodies oriented to h2n2 and h3n2 influenza virus strains. | a method for the analysis of mixtures of antineuraminidase (an) antibodies oriented to antigenically different neuraminidases of h2n2 and h3n2 influenza virus strains is described. the method is based on the finding that the different classes of an antibodies give different titer ratios when reacting with the recombinants a/bel/42 (h0)-a/sing/1/57 (n2) and a/equine/prague/1/56 (heg1)-a/hong kong/1/68 (n2) and a mixture of both recombinants. these titer ratios are determined under the experimenta ... | 1978 | 564681 |
| antiviral and interferon-inducing activities of a new peptidomannan, ks-2, extracted from culture mycelia of lentinus edodes. | oral (po) administration of ks-2 to adult ddi mice resulted in a peak serum interferon (if) titer of 800 units (u)/ml 20 hours after administration with detectable levels persisting until 30 hours. after intraperitoneal (ip) injection, a peak serum if titer of 1,600 u/ml was detected and it followed the same time course as that of oral administration. the if induced by ks-2 shared certain physico-chemical properties with the standard preparation of immune if and was not neutralized by an antiser ... | 1979 | 575532 |
| crystallization and peptide maps of neuraminidase "heads" from h2n2 and h3n2 influenza virus strains. | | 1978 | 664233 |
| on the origin of the human influenza virus subtypes h2n2 and h3n2. | | 1978 | 664248 |
| effect of temperature on the order of electrophoretic migration of influenza virus neuraminidase and nucleoprotein genes in acrylamide gels lacking denaturing agents. | when subjected to electrophoresis at 33 degrees c in 3% polyacrylamide gels with no urea added, the nucleoprotein and neuraminidase genes of an h2n2 and h3n2 virus migrate as rna bands 5 and 6 respectively. if the temperature of electrophoresis is increased to 46 degrees c, however, this order of migration is reversed. | 1978 | 690606 |
| influenza a virus interaction with murine lymphocytes. ii. changes in lymphocyte surface properties induced by influenza virus a/japan 305 (h2n2). | this report describes changes in surface properties of rat thoracic duct lymphocytes (tdl) induced by influenza virus a/japan 305 (h2n2). after incubation with virus at 37 degrees c, sialic acids were released from the membranes of tdl with concomitant reduction in their mean electrophoretic mobility. autoradiographs of tdl which had been incubated with 125i virus at 4 degrees c showed that the particles attached to nearly all the lymphocytes although there was variation in the amount of virus b ... | 1976 | 956657 |
| preparation-conditioned changes of the antigenicity of influenza virus neuraminidases. | the influenza virus strains a/sing/1/57 (h2n2), a/bel/42 (h0n1) and a/bel/42 (ho)-a/sing/1/57 (n2) were treated with bromelain under reducing conditions and with reducing agent alone, and the antigenicity of the neuraminidase (na) of intact virus and of the split products was tested comparatively. it was found that the antigenicity of na was influenced quantitatively and qualitatively by the preparation procedure. antineuraminidase (an) antibodies obtained after vaccination of guinea pigs with i ... | 1977 | 68766 |
| influenza virus: association of mouse-lung virulence with plaque formation in mouse kidney cells. | in genetic recombination experiments with the mouse-lung-adapted human influenza a/engl/1/61 (h2n2) and an avian influenza strain a/rostock/34 (fpv) (hav1n1) which is avirulent for the mouse lung, recombinants in which hemagglutinin and neuraminidase were either segregated (hav1n2; h2n1) or not segregated (hav1n1) were selected. the recombinants were studied for mouse-lung virulence and their ability to propagate in mouse kidney cells, mouse embryo fibroblasts, chick embryo kidney cells and chic ... | 1976 | 1010711 |
| ability of temperature-sensitive mutants of the recombinant influenza s/n (h2n1) virus to induce immunity to parental (h0n1 and h2n2) viruses. | the behavior in mice of two thermosensitive (ts) mutants (denoted ts217 and ts700) of the recombinant influenza virus s/n (h2n1) was studied. the parental thermoresistant (tr) virus and both of the mutants were capable of inducing protection against pneumotropic a/singapore (h2n2) and a/ws (h0n1) challenge viruses. immunity against the singapore virus, with which the s/n virus shared the hemagglutinin, developed earlier than against the ws virus, with which the s/n virus shared the neuraminidase ... | 1976 | 965084 |
| internal proteins of influenza virus: 35s-methionine peptide maps as genetic markers. | methods are described for the preparation in vivo of 35s-methionine-labelled influenza viruses, the purifiction of the nucleoprotein (np) and matrix (m) proteins and the separation of peptides obtained by protease digestion by two-dimensional thin-layer chromatography. the maps of the m proteins of a/okuda/57(h2n2) and a/finland/4/74(h3n2) were very similar overall but differed in three peptides. hence they could be clearly distinguished. maps of the np proteins of the same strains showed a grea ... | 1977 | 915480 |
| temperature-sensitive mutants of influenza virus. vi. transfer of ts lesions from the asian subtype of influenza a virus (h2n2) to the hong kong subtype (h3n2). | | 1975 | 1171555 |
| cell-mediated immune response to influenza virus infections in mice. | the local and systemic cell-mediated immune (cmi) responses to influenza virus infection in mice were examined by leukocyte migration inhibition and lymphocyte-mediated cytotoxicity tests. mice were inoculated intranasally with 5 50% lethal doses of the a/wsn (h0n1) strain of influenza virus. cells from the lymph nodes draining the upper and lower respiratory tract were used to measure the local response, and the spleen was the source of cells used for systemic determinations. the local response ... | 1976 | 1248876 |
| influenza virus antibodies in parkinsonism. comparison of postencephalic and idiopathic parkinson patients and matched controls. | hemagglutination inhibiting antibodies to four influenza virus strains: a/swine/1976/30 (hswn1), a/pr/8/34 (hon1), a/england/1/51 (h1n), and a/singapore/1/57 (h2n2), were studied in blood serum specimens from 20 patients with postencephalitic and 55 patients with idiopathic parkinson disease and their age- and sex-matched controls. no significant differences were observed in the distribution or the mean titers of antibodies to any of the four strains tested, when the postencephalitic patients an ... | 1977 | 836194 |
| analysis of internal proteins of influenza a (h2n2) viruses isolated from birds in east germany in 1983. | proteins and rnas of influenza a (h2n2) viruses isolated from birds in 1983 in east germany were compared antigenically with those of h2n2 human strains. the electrophoretic mobility of the viral proteins and of the s1-treated double-stranded rnas from two human and six avian strains, as well as the results of eia-tests using monoclonal antibodies to their matrix protein and nucleoproteins indicate an antigenic relationship between the avian isolates and human strains of h2n2 subtype. one of the ... | 1992 | 1279962 |
| [the determination of the genotype of natural reassortant influenza a viruses according to the core protein genes by the methods of competitive dot hybridization and sequencing]. | simultaneous circulation of different subtypes of influenza a viruses provides conditions for reassortant strains formation. a comparative investigation of genome of 47 influenza a virus strains (h1n1, h2n2, and h3n2) was carried out by competitive dot hybridization technique and sequence analysis of some of cdna-copies of the virus genes. all the genes of 43 strains encoding nonglycolysed proteins corresponded to the serum subtype of surface glycoproteins. the reassortant pattern of genome for ... | 1992 | 1290222 |
| antigenic variant of swine influenza virus causing proliferative and necrotizing pneumonia in pigs. | a new antigenic variant of swine influenza virus was isolated from the lungs of pigs experiencing respiratory problems in 7 different swine herds in quebec. pigs of different ages were affected, and the main clinical signs were fever, dyspnea, and abdominal respiration. coughing was not a constant finding of the syndrome. at necropsy, macroscopic lesions included the overall appearance of pale animals, general lymphadenopathy, hepatic congestion, and consolidation of the lungs. histopathologic f ... | 1992 | 1333815 |
| replication of influenza virus in organ cultures of human and simian urogenital tissues and human foetal tissues. | a survey of human adult tissues in organ cultures showed that influenza viruses (a/moscow/1019/65 (h2n2) or a recombinant virus virulent for man (pr/8-a/england/939/69 clone 7a(h3n2)) could infect uterus, bladder and conjunctiva but not oesophagus under the conditions employed; simian bladder and uterus were also susceptible. these results were similar to those already described for corresponding ferret tissues. organ cultures of human foetal nasal mucosa, trachea, oesophagus, small and large in ... | 1975 | 809051 |
| influenza a virus transfectants with chimeric hemagglutinins containing epitopes from different subtypes. | influenza virus transfectants with chimeric hemagglutinins were constructed by using a ribonucleoprotein transfection method. transfectants w(h1)-h2 and w(h1)-h3 contained a/wsn/33(h1n1) (wsn) hemagglutinins in which the six-amino-acid loop (contained in antigenic site b) was replaced by the corresponding structures of influenza viruses a/japan/57(h2n2) and a/hong kong/8/68(h3n2) (hk), respectively. serological analysis indicated that the w(h1)-h3 transfectant virus reacted with antibodies again ... | 1992 | 1370088 |
| influenza viruses differ in recognition of 4-o-acetyl substitution of sialic acid receptor determinant. | equine alpha 2-macroglobulin (em), known to contain both neu5ac and neu4,5ac2 sialic acid residues, was treated with vibrio cholerae sialidase for the selective removal of neu5ac and was compared with the untreated em for its binding by a panel of influenza viruses. type a h3n2 virus strains having leu in position 226 of their hemagglutinin (ha) changed the affinity for sialidase-treated em only slightly, if at all, indicative of their ability to bind the 4-o-ac-substituted neu5ac receptor deter ... | 1992 | 1374985 |
| [the evaluation of the degree of attenuation of cold-adapted influenza a virus strains in cba-strain mouse and syrian hamster models]. | the pattern of the infectious process induced by the epidemic a/leningrad/134/57 (h2n2) virus and its cold-adapted (ca) variants in cba mice and syrian hamsters was studied. the strains under study inoculated into the animals under a mild ether anesthesia differed by virulence, reproductive capacity in the nasopharynx, trachea and lungs, as well as by the isolation rate from extrarespiratory organs of both mice and hamsters. upon intranasal inoculation of mice without anesthesia, the ca strains ... | 1992 | 1413711 |
| cross-protection in mice after immunization with h2n2, h3n2, and heq2neq2 influenza virus strains. | mice were vaccinated with the influenza viruses a/japan/57 (h2n2), a/hong kong/68 (h3n2), and a/equi/miami/63 (heq2neq2) and the hemagglutinin and neuraminidase recombinants derived from these viruses. after infection with the parent viruses, protection was compared with serological findings. it was found that influenza vaccine protects not only against infection with a strain identical or closely related to the vaccine strain, but against heterologous strains as well. vaccination with hong kong ... | 1978 | 711325 |
| type-specific identification of influenza viruses a, b and c by the polymerase chain reaction. | the aim of this study was to develop a polymerase chain reaction for specific detection of influenza a, b, and c rna genomes. three primer sets were selected from conserved regions of the genome coding for the non-structural proteins and were tested on 61 influenza a (22 h1n1, 9 h2n2, and 30 h3n2), 11 influenza b, and three influenza c isolates. specific amplified products were obtained with all these strains after electrophoresis on a 2% agarose gel. the specificity of the reaction was increase ... | 1992 | 1430057 |
| use of single-gene reassortant viruses to study the role of avian influenza a virus genes in attenuation of wild-type human influenza a virus for squirrel monkeys and adult human volunteers. | the transfer of six internal rna segments from the avian influenza a/mallard/new york/6750/78 (h2n2) virus reproducibly attenuates human influenza a viruses for squirrel monkeys and adult humans. to identify the avian influenza a virus genes that specify the attenuation and host range restriction of avian-human (ah) influenza a reassortant viruses (referred to as ah reassortants), we isolated six single-gene reassortant viruses (sgrs), each having a single internal rna segment of the influenza a ... | 1992 | 1551982 |
| [changes in the antigenicity of influenza virus neuraminidases due to various methods of preparation]. | the influenza virus strains a/sing/1/57 (h2n2), a/bel/42 (hon1) and a/bel/42 (ho)-a/sing/1/57 (n2) were treated with bromelain under reducing conditions and with reducing agent alone, and the antigenicity of the neuraminidase (na) of intact virus and of the split products was tested comparatively. it was found that the antigenicity of na was influenced quantitatively and qualitatively by the preparation procedure. antineuraminidase (an) antibodies obtained after vaccination of guinea pigs with i ... | 1978 | 627393 |
| [the ts phenotype of reisolates from children inoculated with live cold-adapted influenza vaccine type a]. | using mutants of fowl plague virus (frv) which have single temperature-sensitive (ts) mutations in some genes, an analysis was carried out on reisolates from children of 3-6 years, vaccinated with a monovaccine from recombinant strains of influenza type a virus. the recombinants were obtained by crossing of current epidemic strains of subtypes a (hini) and a (h3n2) with the cold-adapted (xa) ts-donor of attenuation a/leningrad/134/47/57 (h2n2) from which they, as a rule, inherited 5 ts-mutations ... | 1990 | 1697128 |
| effect of priming infection on serologic response to whole and subunit influenza virus vaccines in animals. | results from studies in humans demonstrated that the serologic responses to a/new jersey (nj)/76 virus vaccines varied according to the age of the vaccine and appeared to be related to previous exposure of vaccinees to the different strains and influenza a virus. experiments in animals were therefore performed to investigate the role of previous infection on responses to a/nj/76 virus vaccines. mice were infected with influenza a viruses representative of the major strains (hsw1n1, h0n1, h2n2, h ... | 1977 | 606796 |
| serological responses to whole and split a/new jersey vaccines in humans and mice following priming infection with influenza a viruses. | experiments were performed in mice to investigate the role of previous infection on responses to a/nj/76 vaccines. results from human studies have demonstrated that the serological responses to a/nj/76 vaccines varied according to the age of the vaccinee and appeared to be related to their previous exposure to the different strains of influenza a virus. mice were infected with influenza a viruses representative of the major strains (hsw1n1, hon1, h2n2, h3n2) and later inoculated with varying dos ... | 1977 | 604108 |
| sequence changes in the live attenuated, cold-adapted variants of influenza a/leningrad/134/57 (h2n2) virus. | nucleotide sequences were determined for the rna segments coding for proteins other than the hemagglutinin and neuraminidase of the a/leningrad/134/57 (h2n2) wild-type (a/len/wt) virus and its two cold-adapted (ca) and attenuated variants, a/leningrad/134/17/57 (a/len/17/ca) and a/leningrad/134/47/57 (a/len/47/ca) that are used in the u.s.s.r. in the preparation of reassortant live attenuated vaccines. ten nucleotide differences were detected between the sequences of the a/len/wt and a/len/17/ca ... | 1992 | 1733114 |
| antibody response to monovalent a/new jersey/8/76 influenza vaccine in pregnant women. | the decision to implement a mass immunization program with a/new jersey/8/76 (hsw1n1) influenza vaccine provided a unique opportunity to evaluate immunological responses during pregnancy. fifty-nine pregnant and 27 nonpregnant women participated in this study. influenza virus hemagglutination-inhhibition antibody titers were determined to a/new jersey/8/76 (hsw1n1), a/japan/305/57 (h2n2), and a/hong kong/8/68 (h3n2) before and after a single dose of monovalent (200 chick cell agglutination units ... | 1979 | 583151 |
| effects of individual inhalation of aerosolized amantadine hydrochloride in mice infected with influenza virus a/bethesda 10/63 (h2n2) and a/hong kong 1/68 (h3n2). | | 1979 | 582762 |
| homologous and heterologous antibody responses to subunit influenza virus vaccine. | in a group of 32 adult volunteers given subunit influenza virus vaccine containing 250 international units (i.u.) of a/victoria/3/75, 250 i.u. of a/scotland/840/74 and 300 i.u. of b/hong kong/8/73, there were substantial increases in the geometric mean homologous haemagglutination-inhibiting (hi) antibody titres. there was also substantial boosting of the antibodies to the earlier variants of the hong kong (h3n2) series and to a later variant of the asian (h2n2) series. there was no boosting of ... | 1978 | 581591 |
| [mutations in the genes coding for hemagglutinin and neuraminidase in cold-adapted variants of the influenza virus a/leningrad/134/57 (h2n2)]. | an analysis of ts-mutations in the genomes of native and cold-adapted variants of influenza a/leningrad/134/57 (h2n2) virus based on the use of fowl plague virus ts mutants was carried out. the recombination test was done by the conventional method in chick embryo fibroblast culture (genes pb2, pb1, pa, np, na, m and ns) or cell systems permissive for reproduction of human influenza virus (gene ha). the cold-adapted strain a/len/17 used for preparation of live influenza vaccine (liv) for adults ... | 1991 | 1882532 |
| replication of animal viruses in differentiating muscle cells: influenza virus a. | cells were cultured from the breast muscle of 11- to 12-day-old chick embryos and were grown under conditions optimal for the development of the cells into terminally differentiated, fused myotubes. myotubes were infected with influenza virus a/ann arbor/6/60(h2n2) at high multiplicity, and synthesis of virus-specific proteins and rnas was detected by haemadsorption, fluorescence microscopy and/or isotope labelling and electrophoresis techniques. provided that myotubes were maintained at tempera ... | 1977 | 562389 |
| 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 |
| [serologic survey of human type a influenza virus infection following 10-year periods of prevalence of h3n2 strains]. | distribution of h.i.a. against a/new jersey/8/76 (hsw1n1), a/pr/8/34 (h0n1), a/fm/1/47 (h1n1), a/japan/305/57 (h2n2) influenza virus strains was determined in 553 serum samples, previously tested for a/hong kong/1/68 virus, collected in the late summer of 1977 in milan and bari. for all variants, distinctive antibody patterns were obtained which reflect periods of prevalence of these viruses in man. so, the peak of positivity and the higher h.i.a. levels were found for a/new jersey/8/76 strain i ... | 1979 | 552822 |
| the localization of influenza virus in the respiratory tract of ferrets: susceptible nasal mucosa cells produce and release more virus than susceptible lung cells. | infectious virus production by ferret nasal mucosa and lung organ cultures has been monitored in both tissue pieces and medium over 24 h following inoculation with an asian (h2n2) strain of influenza virus. freshly prepared cultures of nasal mucosa produced approx. 10-fold more virus per cell than fresh lung cultures. also the nasal mucosa cells liberated into the medium a greater proportion (mean 31%) of the total virus produced than did fresh lung (mean 6%). maintenance of lung explants for 24 ... | 1979 | 521800 |
| differential interaction of virulent and attenuated influenza virus strains with ferret alveolar macrophages: possible role in pathogenicity. | the ferret provides a unique model for the study of human influenza. the interaction between alveolar macrophages and virus strains with different levels of virulence was examined in vitro. the greater virulence of wild-type a strains over type b and c viruses was reflected in the higher production of infectious virus progeny and subsequent cytopathology, even though the expression of viral antigens was equivalent for all strains tested. these included a/ann arbor/6/60 (h2n2) and a/rochester/1/8 ... | 1990 | 2181032 |
| [the use of monoclonal antibodies for the rapid detection of the hemagglutinin of the influenza a virus (h2n2) and its antibodies]. | | 1990 | 2256322 |
| vaccination with inactivated influenza a virus during pregnancy protects neonatal mice against lethal challenge by influenza a viruses representing three subtypes. | a single intraperitoneal injection of pregnant mice with a monovalent formalin-inactivated influenza a virus vaccine protected their offspring against a lethal challenge dose of the same influenza a virus h3n2, h2n2, and h1n1 subtypes, as well as against challenge with the other two subtypes. degree of protection was vaccine dose related. cross-fostering of neonates indicated that protection was conferred by breast milk antibodies. serum virus-specific neutralizing antibodies in the mothers and ... | 1990 | 2304146 |
| deproteinization of influenza virus in the presence of rimantadine. | virion deproteinization and viral rna transport to the isolated cell nuclei have been studied in the presence of rimantadine with rimantadine-sensitive influenza viruses fowl plague (h7n7), a/krasnodar/101/59 (h2n2) and rimantadine-resistant influenza strains (wsn/h1n1 and a/krasnodar/101/59-r). rimantadine failed to affect deproteinization during incubation with the isolated cellular plasma membranes as well as the transport to isolated cell nuclei of the viral rna of either sensitive or resist ... | 1985 | 2408452 |
| [production of recombinants antigenically identical to influenza virus strains circulating in nature]. | recombination of a human influenza virus with an avian influenza virus produced a h2nav2 recombinant with the antigenic properties analogous to those of avian influenza virus (h2nav2) isolated from wild ducks in the far east, ussr. recombination of two avian influenza viruses yielded a recombinant h2n2, an antigenic analogues of influenza a/singapore/1/57 (h2n2) virus which had started an epidemic of influenza in 1957. | 1979 | 506201 |
| cold-adapted variants of influenza a virus: evaluation in adult seronegative volunteers of a/scotland/840/74 and a/victoria/3/75 cold-adapted recombinants derived from the cold-adapted a/ann arbor/6/60 strain. | influenza a/scotland/74 (h3n2) and a/victoria/75 (h3n2) cold-adapted (ca) recombinant viruses, prepared by mating the a/ann arbor/6/60 (h2n2) ca donor virus and influenza a wild-type virus, were evaluated in adult seronegative volunteers (serum hemagglutination-inhibiting antibody titer, </=1:8) for level of attenuation, antigenicity, and genetic stability of the temperature-sensitive and ca phenotypes. at 10(7.0) to 10(7.5) 50% tissue culture infective doses the a/scotland/74 and a/victoria/75 ... | 1979 | 422240 |
| [cytotoxic activity of normal killers and the lymphocytic proliferative response to specific viral antigens in influenza in mice]. | inoculation of cba mice with pathogenic influenza a/pr8/34 (h1n1) virus and non-pathogenic a/krasnodar/101/59 (h2n2) virus demonstrated that the pathogenic strain enhanced the synthesis of serum interferon and activated the function of normal killers, but had a relatively low capacity of causing in vitro proliferative response of spleen lymphocytes of intact and in vivo primed animals. in contrast, the nonpathogenic virus had less marked interferon-inducing capacity and that of activating normal ... | 1987 | 2451352 |
| the analysis of the monoclonal immune response to influenza virus. iii. the relationship between stimulation of virus-primed precursor b cells by heterologous viruses and reactivity of secreted antibodies. | individual splenic precursor b cells from balb/c mice primed with influenza virus pr8[a/pr/8/34 (h0n1)] were stimulated in vitro in the splenic fragment culture system by homologous or various heterologous influenza viruses. the specificity of the stimulated precursor cells was determined by analysis of the antibodies secreted by the ensuing plasma cell clone in a radioimmunoassay (ria). viruses of the h2n2 and h3n2 subtypes were unable to stimulate hemagglutinin (ha)- or neuraminidase (na)-comm ... | 1978 | 305935 |
| nucleotide sequence of the avian influenza a/mallard/ny/6750/78 virus polymerase genes. | the avian influenza a/mallard/ny/6750/78 virus is currently being evaluated as a donor of attenuating genes in the construction of live avian-human influenza a reassortant virus vaccines for use in humans. we determined the nucleotide sequences of the three polymerase gene segments of this virus. this completes the nucleotide sequence of the six transferrable genes of the avian donor virus. comparison of the nucleotide and deduced amino acid sequences of the non-glycoprotein genes of the avian a ... | 1989 | 2483012 |
| heterogeneity of a/singapore/1/57 (h2n2) influenza virus. | the population of a/singapore/1/57 (h2n2) influenza virus was found to contain two types of infectious particle. "normal" virions with a diameter from 100-130 nm, a buoyant density in sucrose of 1.21 g/cm3 and a sedimentation coefficient 770 s represented about 90 percent of the population. in addition, a considerable amount of larger particles (up to 1000 nm) with a buoyant density in sucrose of 1.18 g/cm3 and a sedimentation coefficient of over 1000 s were present. | 1975 | 241224 |
| the measurement of haemagglutinin and matrix protein present on the surface of influenza virus infected p815 mastocytoma cells. | a thermodynamic approach has been used to measure the amount of haemagglutinin and matrix protein expressed at the surface of p815 cells infected for periods between 4.5 and 11 h with either wsn (h0n1) or jap (h2n2) strains of type a influenza virus. this involved measuring the interaction of different concentrations of labelled (fab)2 preparations of specific antibody with normal and infected cells. assuming that one molecule of (fab)2 bound to one molecule of antigen, values for the number of ... | 1979 | 107273 |
| virucidal effect of sodium p-chloromercuribenzoate on influenza viruses attributable to inhibition of virus particle-associated rna-dependent rna polymerase. | sodium p-chloromercuribenzoate (pcmb) caused a noticeable reduction of infectivity of prototype strains of type a and lee strain of type b influenza viruses at concentrations of 100 and 200 mug/ml, respectively, after an incubation at 37 c for 60 min. the virucidal effect on a/aa/2/60 (h2n2) strain was dependent on the concentration of the drug and temperature as well as on the time of incubation. the reagent exerted this effect at a concentration which induced little change in the hemagglutinat ... | 1975 | 1160201 |
| effect of the interferon inducer, dextran phosphate, on influenza virus infection in mice. | intraperitoneal administration of dextran phosphate (mw 40,000) or dp 40, an interferon inducer, was shown to increase the survival rate of mice infected with 10 ld50 dose of influenza a2 virus (h2n2). in the treated mice, a 1-day delay was evident in the virus growth in lung, and production of hai antibody, when compared to the nontreated or dextran-treated controls. more significant was the 2-day delay in the development of lung consolidation, which leads to 40% survival of the treated mice. m ... | 1975 | 1166077 |
| preparation and characterization of live recombinant influenza vaccine. | strain wrl 105 was prepared by recombination between the a/finland/4/74 (h3n2) and attenuated a/okuda/57 (h2n2) strains by a method previously described. a single intranasal dose of wrl 105 strain live attenuated influenza vaccine was administered to volunteers at three dose levels and homologous serum antibody titres and virus excretion were monitored. doses greater than 10(6.3)eid50 gave 4-fold or greater increases in antibody titre in 80% of seronegative volunteers. | 1976 | 955267 |
| characterization of the m protein and nucleoprotein genes of an avian influenza a virus which are involved in host range restriction in monkeys. | a reassortant virus possessing rna segment 7, which codes for the m1 and m2 proteins, of the avian influenza a/mallard/new york/6750/78 (h2n2) virus and the other seven rna segments of the human influenza a/udorn/307/72 (h3n2) virus had been shown previously to be markedly restricted in replication in the respiratory tract of squirrel monkeys. in contrast, a reassortant possessing segment 7 of another avian influenza virus, a/pintail/alberta/119/79 (h4n6), and the seven other rna segments from t ... | 1989 | 2609730 |
| comparative studies of wild-type and 'cold-mutant' (temperature sensitive) influenza viruses: geneology of the matrix (m) and non-structural (ns) proteins in recombinant cold-adapted h3n2 viruses. | the matrix (m) protein of the h2n2 virus a/ann arbor/6/60 may be distinguished from m protein of several h3n2 viruses and a/new jersey/76 (hswini) by sds acrylamide gel electrophoresis using a discontinuous buffer system. the smallest rna (rna 8) of the a/ann arbor/6/60 virus may be distinguished from rna 8 of several h3n2 viruses by acrylamide gel electrophoresis in 3% or 3-6% gels in the absence of urea, if electrophoresis is done at 30 to 36 degrees c or 20 degrees c respectively. ten clones ... | 1977 | 915481 |
| 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 ... | 1989 | 2795713 |
| [successive isolation of hemagglutinin and neuraminidase from influenza virus a/kransnodar/101/59 (h2n2) using bromelain]. | | 1989 | 2806058 |
| kinetics of reactions of antihemagglutinin and antineuraminidase antibodies with h2n2 and h3n2 influenza virus strains and description of a modification of the photometric acu method for titration of antineuraminidase antibodies. | the isotherms describing the reactions of selected h2n2 and h3n2 virus strains with antihemagglutinin (ah) and antineuraminidase (an) antibodies were established by use of a photometric hemagglutination inhibition test [antibody concentration unit (acu) method]. it was found that the an antibody isotherms had significantly higher values of the constant 1/n than did the ah antibody isotherms. this finding confirms for further virus strains the conclusion that the photometric acu method can discri ... | 1976 | 1259594 |
| induction of protective class i mhc-restricted ctl in mice by a recombinant influenza vaccine in aluminium hydroxide adjuvant. | induction of class i mhc-restricted cytotoxic t lymphocyte (ctl) responses by soluble proteins or peptides requires complex adjuvants or carrier systems which are not licensed for use with human vaccines. the data presented in this report show that vaccination with a highly purified recombinant influenza protein antigen in aluminium hydroxide adjuvant, the only adjuvant currently licensed for clinical use, elicited class i restricted ctl and protection from lethal challenge with h1n1 and h2n2 vi ... | 1992 | 1349448 |
| 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. | 1987 | 2892383 |
| the attenuation phenotype conferred by the m gene of the influenza a/ann arbor/6/60 cold-adapted virus (h2n2) on the a/korea/82 (h3n2) reassortant virus results from a gene constellation effect. | a single gene reassortant (sgr) virus that derived its m gene from the attenuated influenza a/ann arbor/6/60 cold-adapted (ca) donor virus and the remaining genes from the a/korea/82 (h3n2) wild type (wt) virus (designated a/korea/82 ca m-sgr) was previously shown to be attenuated in mice, hamsters, ferrets, and humans. the attenuation (att) phenotype of this sgr virus could result directly from an altered function of the mutant m gene product of the a/ann arbor/6/60 ca virus, which differs from ... | 1992 | 1413993 |
| 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 ... | 1989 | 2913033 |
| the use of live attenuated influenza vaccine ts-1(e) in man. | live temperature-sensitive influenza virus vaccines were tested in two volunteer experiments. the vaccine virus was originally derived from a temperature-sensitive mutant of influenza a/great lakes/1965 (h2n2) produced by chemical mutagenesis with 5-fluorouracil. the ts lesions of this strain were subsequently transferred (hi) antibody. only 9 men (13%) were infected, presumably as a result of over-attenuation of the virus and/or insufficient titer of the inoculum. in the second experiment (1974 ... | 1976 | 782966 |
| [identification of the hemagglutinating antigens of the influenza virus by immunoenzyme analysis]. | highly active test sera detecting the presence of virus antigen both in concentrated and purified preparations and in allantoic virus cultures directly adsorbed on the solid phase have been proposed for successful identification and detection of influenza a and b virus variants. after direct sorption of purified and concentrated virus preparations, the test sera to influenza a (h1n1, h2n2, h3n2) virus detect the virus antigen in a concentration of 8 ng/ml, test sera to influenza b virus in a con ... | 1988 | 3064428 |
| [isolation and characteristics of monoclonal antibodies to influenza virus types a and b]. | monoclonal antibodies (mca) to influenza type a (10f) and b (5h and 6h) viruses have been prepared. by immunoblotting method, mca 10f were found to be specific for np-protein of influenza a virus, and mca 5h and 6h to be specific for hemagglutinin of influenza b virus. it was established that the 10f clone interacted with all the investigated influenza a virus strains with different antigenic formulae (h1n1, h2n2, h3n2) and could be used for typing of this virus type. clones 5h and 6h react spec ... | 1988 | 3064429 |
| further studies on cold adapted variants of human influenza virus a/krasnodar/101/59 (h2n2) with special reference to genetic stability of attenuation markers. | a previously described cold adapted (ca) attenuated virus, k/25, derived from parent strain a/krasnodar/101/59 (h2n2), was further modified by 35 additional passages in chick embryos at suboptimal temperature. the virus obtained had retained a distinct ts and ca phenotype and some other markers of attenuation but differed from formerly isolated ca variants by its higher genetic stability connected with an increased growth capacity in chick embryos. | 1991 | 1686959 |
| the recognition of a viral antigenic moiety by class i mhc-restricted cytolytic t lymphocytes is limited by the availability of the endogenously processed antigen. | the transmembrane hydrophobic domain of the type a influenza a/japan/305/57 (h2n2) hemagglutinin (ha) contains an immunodominant site encompassing amino acids 523-545 (j523-545) recognized by class i mhc-restricted cytolytic t lymphocytes (ctl). class i ctl of two fine specificity subsets map to this transmembrane (tm) site. one of these ctl subpopulations is subtype specific. these t lymphocytes recognize the site generated during infection of target cells with a/japan/305/57 virus (h2n2) but n ... | 1990 | 1700000 |
| the adjuvanticity of gamma inulin. | gamma-inulin (g-in) is a polymorph identified as the active component of inulin preparations that specifically activates the alternative pathway of complement (apc). the apc is central to many leucocyte functions, including b cell activation. we show here that g-in, when formulated as a pure, endotoxin-free, fine suspension insoluble at 37 degrees c and given at 50-100 micrograms per mouse, is a potent adjuvant for both humoral and cell-mediated responses to a variety of antigens. g-in increased ... | 1988 | 3265692 |
| [features of mutated changes of genomic rna of cold-adapted and hr-variants of influenza group a virus, detected by rna:rna hybridization]. | the presence of mutations in the majority of the genes of cold-adapted strains a/leningrad/134/17/57 (h2n2), a/leningrad/134/47/57 (h2n2) and a/pr/8/59/1 (h1n1) of influenza a virus has been demonstrated by the rna-rna hybridization with the subsequent electrophoresis of double-stranded rna in 7.5% polyacrylamide gel. the strains were cultivated 17, 47 and 59 passages in the chicken embryos at 25 degrees c. in the genomes of variants passaged in chicken embryos at optimal temperature of incubati ... | 1990 | 1706066 |
| age-related heterologous antibody responses to influenza virus vaccination. | heterologous hemagglutination-inhibiting (hai) antibody responses to influenza a/new jersey/76 (hsw1n1) virus vaccine were examined in individuals receiving doses of 200, 400, or 800 chick cell-agglutinating units of whole-virus or split-virus products during the 1976 national influenza vaccine test program. vaccination with influenza a/new jersey/76 virus produced a high rate of heterologous antibody response to influenza a/pr/8/34 (h0n1) and a/fm/1/47 (h1n1) viruses in persons whose original a ... | 1977 | 606792 |
| characterisation of an ionisable group involved in binding and catalysis by sialidase from influenza virus. | the effect of ph on the kinetics of sialidase purified from influenza virus (a/tokyo/3/67, h2n2) was investigated. a pk of 9.0 for inhibition of the enzyme by three competitive inhibitors, due to an ionisable group in the active site, was observed. a similar pk was observed for v/km for the fluorogenic substrate 2-(4-methylumbelliferyl)-n-acetyl-alpha-d-neuraminic acid. however, the shape of the v/km profile indicates that this substrate is sticky. solvent perturbation experiments indicated that ... | 1991 | 1768256 |
| [interepidemic influenza in bulgaria based on laboratory research data]. | during the interepidemic periods of 34 years (1955-1988) the national influenza centre of bulgaria with the aid of 11 supporting stations investigated a total of 27240 nasopharyngeal washings and 42530 paired sera of patients with acute respiratory diseases. eighty strains of subtype a (h1n1) influenza virus, 60 strains of subtype a (h2n2), 148 strains of subtype a (h3n2), 3 strains of subtype a (heg2, neg2), 2 strains of subtype a (hsw1n1), 14 strains of type b, and 6 strains of type c were iso ... | 1991 | 1803771 |
| detection of influenza viruses in throat swab by using polymerase chain reaction. | an assay protocol based on exploiting the polymerase chain reaction (pcr) for the direct detection of influenza virus in throat swab is described. by use of the mixture of h1 and h3 primers, it was possible to determine the subtype of the influenza a viruses simultaneously. no visible band was detected after pcr of influenza b or a (h2n2) viruses with a pair of h1 or h3 primers. the dilution experiment showed that the influenza viruses, as few as 1.3-6 plaque-forming units, were sufficient for d ... | 1991 | 1870441 |
| recognition of cloned influenza virus hemagglutinin gene products by cytotoxic t lymphocytes. | the influenza a virus hemagglutinin (ha) is an integral membrane glycoprotein expressed in large quantities on infected cell surfaces and is known to serve as a target antigen for influenza virus-specific cytotoxic t lymphocytes (ctl). despite the fact that has derived from different influenza a virus subtypes are serologically non-cross-reactive, the ha has been implicated by previous experiments to be a target antigen for the subset of t cells capable of lysing cells infected with any human in ... | 1986 | 3485199 |
| infectivity and reactogenicity of reassortant cold-adapted influenza a/korea/1/82 vaccines obtained from the usa and ussr. | the safety and immunogenicity of two live influenza a virus vaccine strains, the cr 59 and 17/25/1 cold-adapted (ca) reassortants, were evaluated in 170 healthy young adult volunteers. the vaccines were produced by recombining a/korea/1/82 (h3n2) wild-type virus with either a/ann arbor/6/60 (h2n2) or a/leningrad/134/17/57 (h2n2) ca donors of attenuation. both vaccines were well tolerated in volunteers. the 17/25/1 strain, prepared from a/leningrad, infected at least 70% of seronegative volunteer ... | 1987 | 3499246 |
| effect of neuraminidase on potency of inactivated influenza virus vaccines in mice. | the protective effect of neuraminidase was studied in a mouse protection test using isolated neuraminidase of a2/aichi/68(h3n2) virus and the complete recombinant virus a/eq(heq-1)-hk(n2) as antigens. immunized mice were protected against a2/aichi(h3n2) challenge virus; however, the protection rate was low in comparison to animals immunized with comparable amounts of the complete a2/68(h3n2) virus9 furthermore there was no cross-protection against a2/asia/57(h2n2) challenge virus. the protective ... | 1975 | 1126575 |
| cell-mediated immune responses to influenza virus antigens expressed by vaccinia virus recombinants. | recombinant vaccinia viruses enable studies of immune recognition of antigens expressed from single viral genes. we have constructed recombinants expressing the haemagglutinin (ha) and nucleoprotein (np) genes of the influenza virus a/pr/8/34 (h1n1). these recombinant viruses together with a recombinant expressing the ha from influenza virus a/jap/305/57 (h2n2) have been used to examine the cytotoxic t lymphocyte (ctl) response to these influenza virus antigens. both antigens are recognised by m ... | 1986 | 3509883 |
| [the effect of amplifying reproduction of influenza virus in mouse lungs during simultaneous infection with two cold-adapted strains]. | reproduction of cold-adapted (ca) strains of influenza virus in the lungs of white mice after separate and combined inoculation and the properties of isolates derived from the infected animals were studied. it was shown that after combined inoculation with ca and ts strains a/leningrad/134/17/57 (h2n2) and a/pr/8/59/1 (h1n1) ca recombinants could develop loosing some ts mutations and possessing (unlike the master strains) pneumo-virulence for mice. all the pneumo-virulent reassortants inherited ... | 1989 | 2609639 |
| [regularities of formation in a general population of serum antibodies to previously circulated influenza a viruses]. | the spectrum of antibody production against hemagglutinin of all known influenza a virus serotypes after influenza a (h3n2) infection in persons of all age groups (from 1 month to 72 years) was analysed to investigated the regularities of accumulation of antibodies against influenza a viruses gone out of circulation. for the same purpose, a long-term (many years) longitudinal analysis of serum anti-ha antibody levels against "old" influenza a (hsw1n1), a (h0n1), a (h1n1), a (h2n2), and a (h3n2) ... | 1989 | 2609640 |
| molecular hybridization with dna-probes as a laboratory diagnostic test for influenza viruses. | the possibilities of using dna-copies of different influenza a virus genes cloned with recombinant bacterial plasmids for the detection of virus-specific rna by molecular dot-hybridization were analyzed. high specificity of rna identification has been demonstrated and it has been shown expedient to use dna-probes with high-conservative virus genes (polymerase, nucleoprotein, or matrix) for the detection of influenza a virus subtypes (h1n1, h2n2, h3n2) and probes with corresponding hemagglutinin ... | 1987 | 3617494 |
| isolation of influenza a viruses from migratory waterfowl in san-in district, western japan in the winter of 1983-1984. | certain species of winter migratory waterfowl in san-in district, western japan, were surveyed for influenza virus from november 1983 to march 1984. faeces of the waterfowl were collected regularly at five stations. eleven influenza a viruses including h5n3 and h10n4 subtypes were isolated from 450 faecal samples from whistling swans, 28 viruses including h2n2 and h10n4 subtypes were isolated from 362 faecal samples from pintails; and subtype h13n6 was isolated from 240 faecal samples of black-t ... | 1987 | 3685630 |
| [the structure of oligosaccharide fragments of glycoproteins from influenza virus a/krasnodar/101/59/(h2n2)--heavy and light chains of hemagglutinin and neuraminidase]. | the structure and heterogeneity of carbohydrate chains of hemagglutinin (ha) and neuraminidase (na), the surface glycoproteins of influenza virus a/krasnodar/101/59 (h2n2), were investigated. hemagglutinin was reduced with beta-mercaptoethanol and its heavy (ha1) and light (ha2) chains were separated by gel chromatography. amino acid and sugar composition of ha1, ha2 and na was elucidated. the carbohydrate chains of the glycoproteins were cleaved off by the alkaline libh4 treatment and oligosacc ... | 1989 | 2634965 |
| 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 ... | 1988 | 2846435 |
| isolation of influenza a viruses from migratory waterfowls in san-in district, western japan, in the winter of 1982-1983. | from november 1982 to march 1983, winter migratory waterfowls of some species staying in san-in district, western japan, were surveyed for influenza virus at five stations. a total of eight influenza a viruses were isolated from 354 faeces samples of whistling swans; in contrast, no virus was isolated from any sample of 261 black-tailed gulls, of 113 pintails and of 10 mallards. five of eight isolates belonged to human pandemic subtype h2n2, two isolates belonged to fowl plague subtype h7n7, and ... | 1987 | 2891283 |
| [suppressive action of the influenza virus on the bone marrow stem cells of mice]. | the effect of pathogenic and noninfectious influenza viruses with different surface antigens on colony-forming stem cells of (cba x c57bl/6)f1 mice was studied. bone marrow cells were infected with a/pr8/34 (h1n1)/a/krasnodar/101/59 (h2n2) viruses, a recombinant a/pk-6-3 (h2n1) strain thereof, a/khabarovsk/933/77 (h1n1) strain; then they were inoculated intravenously to irradiated (820 rad) syngeneic recipients, and colony-forming units (cfu) were determined in the spleens 9 days after injection ... | 1988 | 2904194 |
| 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 ... | 1988 | 2974219 |
| analysis of virus and host factors in a study of a/peking/2/79 (h3n2) cold-adapted vaccine recombinant in which vaccine-associated illness occurred in normal volunteers. | live attenuated cold-adapted influenza vaccine is undergoing evaluation in man. several strains have proven to be safe, immunogenic, nontransmissible, and protective against experimental challenge. in this study of a/peking/2/79(h3n2), with six internal genes from the cold-adapted (ca) parent a/ann arbor/6/60(h2n2), we encountered at the highest input multiplicity, 28% illness rate among individuals infected with vaccine. reversion to wild type and excessive viral replication did not occur. phys ... | 1988 | 3183640 |