  The meson-exchange current in nuclei, a long-standing problem in nuclear
physics, is described in modern theory of strong interactions, namely, QCD
expressed in terms of effective chiral Lagrangian field theory. Some old
results are given a modern interpretation and some new results are predicted.
Among the topics treated are an accurate calculation of the radiative np
capture process at thermal energy, the enhanced axial charge transition in
heavy nuclei, Brown-Rho (BR) scaling in dense medium induced by vacuum changes,
dropping meson masses and "mended symmetry" in relativistic heavy-ion processes
and the link between the physics of dilute and dense hadronic systems through a
mapping of effective chiral Lagrangians to Landau Fermi-liquid theory.
