Pandemic influenza A/H1N1 2009 antibodies in the metropolitan area of Buenos Aires in Argentina.

Objective: To estimate the infection prevalence in Buenos Aires during the outbreak of pandemic influenza A/H1N1 2009 virus (A(H1N1)pdm09).

Methods: A(H1N1)pdm09-specific antibodies were measured by hemagglutination inhibition assay in human serum samples collected 6 months after the outbreak and before the introduction of the A(H1N1)pdm09 vaccine in Argentina. Baseline levels of cross-reactive antibodies to A(H1N1)pdm09 were determined by testing 162 serum samples collected before 2009.

Decreased mitochondrial nitric oxide synthase activity and hydrogen peroxide relate persistent tumoral proliferation to embryonic behavior.

Differential expression and activity of constitutive mitochondrial nitric oxide synthase (mtNOS) in the mitochondrial compartment is followed by significant variations in matrix nitric oxide (NO) steady-state concentration. The mitochondrial utilization of NO involves the production of superoxide anion and H(2)O(2), a species freely diffusible outside the mitochondria that participates in the modulation of cell proliferation and apoptosis and in cell transformation and cancer. On these bases, we analyzed the modulation of mtNOS in the frame of cellular redox state in M3, MM3, and P07 murine tumors and their respective cell lines, as compared with normal proliferating and quiescent tissues.