Showing papers on "Influenza A virus published in 1970"
TL;DR: The fowl plague-like (FP-like) virus isolated from man may have been introduced by the patient from an enzootic area and might possess antigens of human influenza virus.
Abstract: and may have been introduced by the patient from an enzootic area [1]; (2) FPV had not previously been demonstrated to survive or multiply in man; and (3) FPV is a member of the avian myxoviruses and has the potential of genetic interaction with animal and human Group A myxoviruses Since myxoviruses possessing the hemagglutinin antigen of FPV and the neuraminidase antigen of human influenza A2ZSingapore757 have been produced in the laboratory [2-4], the possibility existed that the fowl plague-like (FP-like) virus isolated from man might possess antigens of human influenza virus
70 citations
TL;DR: The prophylactic activity of amantadine hydrochloride was tested in turkeys exposed to the malignant influenza A virus strain Turkey/Ontario 7732/66 and it seems that the avian test system seems to be ideally suited for efficacy studies of anti-influenza drugs.
Abstract: The prophylactic activity of amantadine hydrochloride was tested in turkeys exposed to the malignant influenza A virus strain Turkey/Ontario 7732/66. This virus infection, which caused severe disease in all normal turkeys, was markedly reduced in turkeys properly treated with the drug. Optimum effectiveness was obtained only when the drug administration was adequate, uninterrupted and sustained. Infection was prevented, or remained subclinical in about 80% of turkeys given orally a single daily dose of 10 mg amantadine per kg body weight; protection was also good when 0.025 to 0.05% amantadine was incorporated into feed pellets. The avian test system, by its reliability of response, seems to be ideally suited for efficacy studies of anti-influenza drugs.
17 citations
Journal Article•
TL;DR: The localized hemolysis-in-gel method has been adapted to the detection of single cells releasing antibodies to influenza A virus and in mice infected with influenza A the number of cells releasing IgM antibodies specific for the inner component of the virus begins to rise between 24 and 36 hours after virus inoculation and decreases rapidly to the background level by day 20.
Abstract: The localized hemolysis-in-gel method has been adapted to the detection of single cells releasing antibodies to influenza A virus. In mice infected with influenza A the number of cells releasing IgM antibodies specific for the inner component of the virus (RNP antigen) begins to rise between 24 and 36 hours after virus inoculation, reaches a maximum on the 4th day, and then decreases rapidly to the background level by day 20.
10 citations
TL;DR: The complete replication cycle of influenza A virus was studied by means of the electron microscope in Ehrlich ascites tumor cells kept in vitro.
Abstract: The complete replication cycle of influenza A virus was studied by means of the electron microscope in Ehrlich ascites tumor cells kept in vitro. Adsorption of virus in the cold fol
10 citations
TL;DR: In this article, a total of 1601 adult industrial workers were vaccinated with either monovalent inactivated vaccine of the Hong Kong strain of influenza A virus, or with polyvalent vaccine containing only pre-1968 Asian viruses.
Abstract: A total of 1601 adult industrial workers were vaccinated with either monovalent inactivated vaccine of the Hong Kong strain of influenza A virus, or with polyvalent vaccine containing only pre-1968 Asian viruses. Serological investigations on a random sample of volunteers showed that 53/56 (95%) given Hong Kong vaccine developed a significant rise in specific haemagglutination-inhibiting antibody; final titres were 1/48 or greater in 39 (70%) and the GMT (geometric mean titre) was 96·5. After polyvalent Asian vaccine, 40/67 (60%) also produced antibody against Hong Kong virus, but only 21 (31%) had final titres of 1/48 or above, and the GMT rose only to 14·1. An intranasal spray of the Hong Kong vaccine in addition to injected Asian vaccine gave no additional increase in antibody.
Each type of vaccine stimulated a recall of pre-existing antibody against Asian viruses. The possible significance of heterologous responses to the two vaccines is discussed.
The incidence of clinical influenza in the trial population was sporadic, and the infection rates were too low to allow any accurate estimate of the protective efficiency of the two vaccines.
8 citations
TL;DR: Suspensions of Ehrlich ascites tumor cells maintained in vitro were infected with the tumor-adapted strain WSA of influenza A₀ virus and studied by the fluorescent antibody te.
Abstract: Suspensions of Ehrlich ascites tumor cells maintained in vitro were infected with the tumor-adapted strain WSA of influenza A₀ virus and studied by the fluorescent antibody te
5 citations
4 citations
TL;DR: There was little difference between the groups in number or severity of acute respiratory illnesses during the trial or in the number of proven infections with influenza A2/Hong Kong/1968 virus.
Abstract: In a five-week double-blind trial, 132 young adult volunteers received U.K. 2371, a synthetic isoquinoline derivative which had previously been shown to protect volunteers against challenge with certain influenza viruses. A comparable group of 130 volunteers received placebo. There was little difference between the groups in number or severity of acute respiratory illnesses during the trial or in the number of proven infections with influenza A2/Hong Kong/1968 virus. Tablet counts were carried out and single doses of isoniazid were used as a marker to confirm that the lack of prophylaxis was not the result of the failure of volunteers to ingest the tablets. It is possible that the disparity between our results and those obtained in previous volunteer challenge studies may be due to differences in susceptibility of strains of influenza A virus to the isoquinoline drugs.
3 citations
2 citations
TL;DR: No synergistic effect between a strain of influenza A virus and Mycoplasma meleagridis was revealed by clinical signs, incubation periods, levels of antibodies, or necropsy findings when turkey poults were inoculated with either or both agents in two trials.
Abstract: SUMMARY No synergistic effect between a strain of influenza A virus and Mycoplasma meleagridis was revealed by clinical signs, incubation periods, levels of antibodies, or necropsy findings when turkey poults were inoculated with either or both agents in two trials. Synergism under a different set of circumstances is not thereby precluded.
2 citations
TL;DR: It is concluded that inhibition of influenza virus multiplication by UK2054 might result from interaction of the inhibitor with both virus and cells and any direct combination between inhibitor and virus is completely reversible.
Abstract: The isoquinoline compound UK2054 prevents the uptake of influenza virus by susceptible cells. Pre-incubation of virus particles with 500 μg./ml. UK2054 at 37° C. for 2 hr. does not reduce virus infectivity. Host cells vary in their responsiveness to the inhibitory effect of UK2054; virus multiplication is inhibited in chick allantoic cells by lower concentrations than those required to inhibit virus growth in chick embryo fibroblasts. The effectiveness of UK2054 is reduced by the presence of serum.
It is concluded that inhibition of influenza virus multiplication by UK2054 might result from interaction of the inhibitor with both virus and cells. Any direct combination between inhibitor and virus is completely reversible.
Journal Article•
TL;DR: The immune reaction of turkeys and chickens to inactivated preparations of a virulent strain of avian influenza A virus has been examined andimmune birds responded to the live virus challenge with a marked rise in serologic titers which suggest that they were still susceptible to subclinical infection.
Abstract: The immune reaction of turkeys and chickens to inactivated preparations of a virulent strain of avian influenza A virus has been examined. In both species any level of antibody detectable by the hemagglutination inhibition or serum neutralization tests was protective against the challenge exposure. However, some vaccinated birds were protected in the absence of detectable antibody. Chickens responded with higher and longer lasting antibody titers than turkeys to identical antigen preparations. Whereas the vaccine induced protection in chickens for at least 84 days, the immune protection in turkeys barely lasted 42 days. Immune birds responded to the live virus challenge with a marked rise in serologic titers which suggest that they were still susceptible to subclinical infection. These findings are discussed in their relationship to available data on classical fowl plague and influenza in mammals.
TL;DR: Both the neurotropism and the laboratory markers of nws breed true on limiting dilution passage in chick embryos, or after plaque purification in tissue cultures of chick embryo fibroblasts.
Abstract: The ws strain of influenza A virus was the first to be isolated from man (Smith, Andrewes & Laidlaw, 1933) and was propagated successively in ferrets and mice by intranasal infection, and on the chorioallantoic membrane of chick embryos. ws is unique among human influenza viruses in that it gives rise to variants which are neurovirulent for mice inoculated intracerebrally (Stuart-Harris, 1939; Francis & Moore, 1940). Many subsequent attempts to isolate neurotropic variants from other A0, A1 or A2 human influenza viruses have failed.
It can only be a matter of speculation how such variants as nws (Stuart-Harris, 1939) might have arisen from ws. The antigenic constitution of the two strains appears to be identical, but nws differs from ws in a number of laboratory properties other than neurotropism (Burnet & Lind, 1951; Hobson et al. 1968). Both the neurotropism and the laboratory markers of nws breed true on limiting dilution passage in chick embryos, or after plaque purification in tissue cultures of chick embryo fibroblasts.
01 Jan 1970
TL;DR: Serological investigations on a random sample of volunteers showed that 53/56 given Hong Kong vaccine developed a significant rise in specific haemagglutination-inhibiting antibody, which stimulated a recall of pre-existing antibody against Asian viruses.
Abstract: SUMMARY A total of 1601 adult industrial workers were vaccinated with either monovalent inactivated vaccine of the Hong Kong strain of influenza A virus, or with polyvalent vaccine containing only pre-1968 Asian viruses. Serological investigatiom on a random sample of volunteers showed that 53/56 (95 °/O) given Hong Kong vaccine developed a significant rise in specific haemagglutination-inhibiting antibody; final titres were 1148 or greater in 39 (70°/O) and the GMT (geometric mean titre) was 9665. After polyvalent Asian vaccine, 40167 (60%) also produced antibody against E[ong Kong virus, but only 21 (31 °/O) had final titres of 1/48 or above, and the GMT rose only to 14*1. An intranasal spray of the Hong Kong vaccine in addition to injected Asian vaccine gave no additional increase in antibody. Each type of vaccine stimulated a recall of pre-existing antibody against Asian viruses. The possible significance of heterologous responses to the two vaccines is discussed. The incidence of clinical influenza in the trial population was sporadic, and the infection rates were too low to allovv any accurate estimate of the protective efficiency of the two vaccines.
TL;DR: Inhibitory activity of ABOB on new type of influenza A virus (Aichi/2/68 strain), was tested in this study.
Abstract: Many papers report the inhibitory effect of N1, N1- anhydrobis-(β-hydroxyethyl) biguanide hydrochloride (ABOB) on influenza virus multiplication and its prophylactic and therapeutic evaluation in clinical trials.Inhibitory activity of ABOB on new type of influenza A virus (Aichi/2/68 strain), was tested in this study. This type of virus came into epidemic in Hong Kong in summer 1968. The antigenic properties of this virus were a little different from type A2 virus which is a previous epidemic strain.