  We have built an effective Walecka-type hadronic Lagrangian in which the
hadron masses and the density dependence of the coupling constants are deduced
from the quark dynamics using a Nambu-Jona-Lasinio model. The parameters of
this Nambu-Jona-Lasinio model have been determined using the meson properties
in the vacuum but also in the medium through the omega meson mass in nuclei
measured by the TAPS collaboration. Realistic properties of nuclear matter have
been obtained.
