Sunday, August 18, 2019

Influenza Viruses Essay -- Diseases, Birds

Influenza viruses existing in birds continue to be a source for a diverse combination of antigenic subtypes including 16 hemagglutinin (HA) and 9 neuraminidase (NA) and represent a large reservoir of novel antigens to which the human population is naà ¯ve [1,2](1)) (Seasonal influenza epidemics are a major public health concern, accounting for five million severe cases worldwide [1](4))(Annually, influenza types A cause human outbreaks responsible for substantial mortality and morbidity, particularly in high risk groups, such as infants, elderly, and immunocompromised individuals.(5)).(3)) (The influenza virus is one of the most devastating viral diseases due to being highly contagious which easily spreads as an aerosol and causes acute viral respiratory disease and mortality to susceptible groups. In order to prevent the spread of seasonal or pandemic outbreaks of influenza, vaccination is a powerful and cost-effective means [1](15)) (Protection against influenza virus is primarily mediated by antibodies to the viral hemagglutinin (HA) [2,3]) ,HA is the major surface glycoprotein of the virion and responsible for the attachment and penetration of viral particles into cells during the initial stages of infection.((5)((8)) (Successful prophylactic influenza vaccines elicit efficient HA-specific systemic antibody, which can bind the virus and inhibit early events in the influenza virus infection.(6)) Different types of influenza vaccines such as subunit [7-10], attenuated [11,12], and inactivated influenza vaccines[14] are available although the inactivated ones are the most widely used in the commercial scale [6]. ((12) (the major substrate for the preparation of inactivated influenza vaccines is embryonated chicken’s egg .((1) (In c... ... the P1 baculovirus stock In Sf-900 III Medium was Prepared, as appropriate. To do this, sequentially 0.25 ml of the baculovirus stock was diluted in 2.25 ml of Sf-900 medium. The dilutions 10–4 to10–8 were used in our assay. The medium from each well removed, immediately replace with 1 ml of the appropriate virus dilution and incubated for 1 hour at room temperature. Plaquing medium containing 12.5 ml 4% Low Melting Agarose and 37.5 ml Sf-900III was prepared and incubated at 40ËšC water bath until use. Following the 1 hour incubation, the medium containing virus from the wells removed and replaced with 2 ml of plaquing medium. Allowed agarose overlay at room temperature until to harden. The plates incubated at a 27ËšC humidied incubator for 7–10 days. To improve the visualization of plaques, the plates were stained by 0.5 ml Neutral Red solution (1 mg/ml). (21) Influenza Viruses Essay -- Diseases, Birds Influenza viruses existing in birds continue to be a source for a diverse combination of antigenic subtypes including 16 hemagglutinin (HA) and 9 neuraminidase (NA) and represent a large reservoir of novel antigens to which the human population is naà ¯ve [1,2](1)) (Seasonal influenza epidemics are a major public health concern, accounting for five million severe cases worldwide [1](4))(Annually, influenza types A cause human outbreaks responsible for substantial mortality and morbidity, particularly in high risk groups, such as infants, elderly, and immunocompromised individuals.(5)).(3)) (The influenza virus is one of the most devastating viral diseases due to being highly contagious which easily spreads as an aerosol and causes acute viral respiratory disease and mortality to susceptible groups. In order to prevent the spread of seasonal or pandemic outbreaks of influenza, vaccination is a powerful and cost-effective means [1](15)) (Protection against influenza virus is primarily mediated by antibodies to the viral hemagglutinin (HA) [2,3]) ,HA is the major surface glycoprotein of the virion and responsible for the attachment and penetration of viral particles into cells during the initial stages of infection.((5)((8)) (Successful prophylactic influenza vaccines elicit efficient HA-specific systemic antibody, which can bind the virus and inhibit early events in the influenza virus infection.(6)) Different types of influenza vaccines such as subunit [7-10], attenuated [11,12], and inactivated influenza vaccines[14] are available although the inactivated ones are the most widely used in the commercial scale [6]. ((12) (the major substrate for the preparation of inactivated influenza vaccines is embryonated chicken’s egg .((1) (In c... ... the P1 baculovirus stock In Sf-900 III Medium was Prepared, as appropriate. To do this, sequentially 0.25 ml of the baculovirus stock was diluted in 2.25 ml of Sf-900 medium. The dilutions 10–4 to10–8 were used in our assay. The medium from each well removed, immediately replace with 1 ml of the appropriate virus dilution and incubated for 1 hour at room temperature. Plaquing medium containing 12.5 ml 4% Low Melting Agarose and 37.5 ml Sf-900III was prepared and incubated at 40ËšC water bath until use. Following the 1 hour incubation, the medium containing virus from the wells removed and replaced with 2 ml of plaquing medium. Allowed agarose overlay at room temperature until to harden. The plates incubated at a 27ËšC humidied incubator for 7–10 days. To improve the visualization of plaques, the plates were stained by 0.5 ml Neutral Red solution (1 mg/ml). (21)

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