  We consider spin and electronic properties of itinerant electron systems,
described by the spin-fermion model, near the antiferromagnetic critical point.
We expand in the inverse number of hot spots in the Brillouin zone, N and
present the results beyond previously studied $N = \infty $ limit. We found two
new effects: (i) Fermi surface becomes nested at hot spots, and (ii) vertex
corrections give rise to anomalous spin dynamics and change the dynamical
critical exponent from z=2 to z>2.
  To first order in 1/N we found $z = 2N/(N-2)$ which for a physical N=8 yields
$z\approx 2.67$.
