  Gluonic contributions to the self-energy of a nucleon have been investigated
in an effective theory. The couplings of the topological charge density to
nucleons give rise to OZI violating nucleon interactions. The one-loop
self-energy of a nucleon arising due to these interactions have been calculated
using a heavy baryon chiral perturbation theory. The divergences have been
regularized using form factors. The nontrivial structure of the QCD vacuum has
also been taken into account.
