The "Spanish" influenza pandemic of 1918 was characterized by exceptionally high mortality, especially among young adults. The surface proteins of influenza viruses, hemagglutinin and neuraminidase, play important roles in virulence, host specificity, and the human immune response. The complete coding sequence of hemagglutinin was reported last year. This laboratory has now determined the compl...

Antiserum specific for influenza A2 neuraminidase was produced by immunization of rabbits with the purified enzyme which had been isolated by electrophoresis from the proteins of a detergent-disrupted AoA2 influenza virus recombinant [X-7 (Fl)]. This recombinant contained hemagglutinin of the Ao subtype and A2 neuraminidase. Antiserum to the isolated A2 neuraminidase did not react in any of fou...

Background and Aims: For many centuries herbs spices have traditionally been used to treat or manage a variety of diseases. The formulation food supplements containing single multiple is now popular. These formulations provide biochemical, pharmacological medicinal benefits due their diverse phytochemical constituents. Methods: In the present study, Diapin® – supplement Olea europaea L. leaves...

Influenza virus neuraminidase (NA) cleaves terminal sialic acid residues on oligosaccharide chains that are receptors for virus binding, thus playing an important role in the release of virions from infected cells to promote the spread of cell-to-cell infection. In addition, NA plays a role at the initial stage of viral infection in the respiratory tract by degrading hemagglutination inhibitors...

Background: Sialic acid is a component of serum that is elevated in diseases such as diabetes and certain malignancies. The normal range of SSA concentration and serum neuraminidase activity in different populations are varied, probably due to racial differences. Objective: The purpose of the present study was to obtain the average SSA concentration and serum neuraminidase activity, in an Irani...

The Thomsen-Friedenreich antigen (T-antigen) is a cryptic disaccharide structure on human erythrocytes and is supposed to be expressed in an unhidden form on carcinoma cells. We tested the ability of four anti-T reagents (i.e., peanut agglutinin, human and rabbit anti-T antisera, and monoclonal anti-T antibodies) to agglutinate neuraminidase treated human erythrocytes and compared their capacit...

D222G/N substitutions in A(H1N1)pdm09 hemagglutinin may be associated with increased binding of viruses causing low respiratory tract infections and human pathogenesis. We assessed the impact of such substitutions on the balance between hemagglutinin binding and neuraminidase cleavage, viral growth and in vivo virulence.Seven viruses with differing polymorphisms at codon 222 (2 with D, 3 G, 1 N...

CONTEXT Very little is known about the frequency of generation and transmissibility of influenza B viruses with reduced sensitivity to neuraminidase inhibitors. Furthermore, transmission of resistant virus, whether influenza A or B, has not been recognized to date. OBJECTIVE To assess the prevalence and transmissibility of influenza B viruses with reduced sensitivity to neuraminidase inhibito...

Treatment of mouse-spleen cells with galactose oxidase (EC 1.1.3.9) after incubation with neuraminidase (EC 3.2.1.18) induced extensive blastogenesis. Treatment of the cells with galactose oxidase before incubation with neuraminidase had very little stimulatory effect. Either of these enzymes alone had practically no effect on the cells. The lymphocyte transformation induced by galactose oxidas...