Showing papers on "Influenza A virus published in 1971"

Neurological Complications of So-called “Influenza”: A Winter Study in South-east Wales

Abstract: Acute neurological disorder followed an upper respiratory infection in 19 patients in south-east Wales during the winter of 1969-70. Spinal and radicular syndromes predominated and included seven cases of transverse myelopathy. Serological tests suggested that the preceding infection was due to influenza A virus in eight cases, to other viruses in six, and were negative in five.

Genetic recombination between influenza viruses A0/NWS and A 2/Hong Kong

Abstract: Genetic cross was performed in human conjunctival cell cultures between two strains of influenza A virus, Ao/NWS and A2/Hong Kong, both of which plaque with high efficiency on the above cells and which differ from each other in some genetic markers. Clones of progeny virus from mixed infection were isolated in the absence of selective procedures and individually tested for the following marker characteristics; the serotype of the hemagglutinin and the neuraminidase, plaque size, plaque forming capability on FL cells, and requirement of DEAE-dextran for plaque formation. Characterization of 42 clones showed the recombination frequency in two factor cross between the above markers ranged from 18 to 43%. There was no indication of linkage between the markers employed. From the absence of recombination within the serotype of the hemagglutinin or that of the neuraminidase, it was suggested that recombination occurs mainly by exchange of cistrons. Three clones were suspected to be initiated by partially heterozygous virus particles.

Influenza Virus Encephalitis in Squirrel Monkeys Receiving Immunosuppressive Therapy

Abstract: Influenza virus has been implicated as the cause of acute human encephalitis (1), and may possibly be involved in the pathogenesis of certain chronic neurologic disorders (2) However, experiments concerning the effects of the virus on the nervous system have been limited largely to rodents, and influenza virus encephalitis in primates has not yet been described We now report the production of encephalitis following intracerebral challenge of immunosuppressed monkeys with influenza virus Materials and Methods Young squirrel monkeys ( Saimiri sciureus ) weighing approximately 500 g were inoculated with neurotropic strains (NWS and WSN) of influenza A virus The NWS strain was kindly supplied by Dr E Kilbourne and was passaged once in mouse brain The WSN strain, which previously had been passaged five times in Madin-Darby bovine kidney (MDBK) cells (3), was the gift of Dr P Choppin Stock NWS and WSN strains contained 50 × 10 5 and 19 × 10 80 PFU (plaque-forming units)/ml, respectively

Cytoplasmic Synthesis of an Arginine-Rich Nuclear Component During Infection with an Influenza Virus

Abstract: A component relatively rich in arginine which was induced by infection with an influenza virus was synthesized in the cytoplasm of the infected cell and migrated to the nucleus. This conclusion was drawn from the grain distribution in autoradiograms and the displacement of 3H-arginine in isolated cytoplasmic and nuclear fractions after a short pulse and subsequent chase.

A new influenza A virus infection in turkeys. VII. Comparative immunology.

Abstract: Four influenza A strains isolated from turkeys in Ontario as well as strain Chicken/Scotland/59 were found to immunize turkeys against the lethal disease caused by virus Turkey/Ontario 7732/66 (V7732). These viruses form the avian influenza A serotype 5 (AA5). Immunoprotection against V7732 was not obtained with influenza viruses of other serotypes. Immunoprotective relationships among AA5 viruses were not always demonstrable in hemagglutination-inhibition (HI) and serum-neutralization (SN) tests, especially with turkey and mammalian antisera; better correlation between immunoprotection and these in vitro tests was seen with chicken antisera. The implications of these findings relative to virus classification, serodiagnosis and vaccination are discussed.