  In this work we extend our formalism to study meson-baryon interactions by
including $s$- and $u$-channel diagrams for pseudoscalar-baryon systems. We
study the coupled systems with strangeness $-1$ and focus on studying the
isospin-1 resonance(s), especially in the energy region around 1400 MeV. By
constraining the model parameters to fit the cross section data available on
several processes involving relevant channels, we find resonances in the
isoscalar as well as the isovector sector in the energy region around 1400 MeV.
