The present invention provides compounds of Formula (I): ##STR00001## or
a stereoisomer or pharmaceutically acceptable salt form thereof, wherein
the variables A, R.sup.1, R.sup.2, R.sup.3, R.sup.4, Z, U, X, Y, Z.sup.a,
and n are defined are as defined herein, which are useful as inhibitors
of matrix metalloproteinases (MMP) and/or TNF-.alpha. converting enzyme
(TACE), or a combination thereof.