Selected heterocyclecarbonyl amino acid hydroxyethylamino sulfonamide compounds are effective as retroviral protease inhibitors, and in particular as inhibitors of HIV protease. The data processing apparatus comprises a processing unit operable to issue a series of access requests, each access request having associated therewith an address of a data value to be accessed. The process comprises the step of passing the first stream through an adsorbent bed having a crystalline microporous material that preferentially adsorbs methanol, ethanol andor dimethyl ether over the C3+ hydrocarbons. A bundle unwrapping machine according to the invention includes a conveyor by which bundles are presented to the unwrapping machine for opening. The actuator assembly is secured to a proximal end portion of the inner catheter as it protrudes proximally from the hub, where it is accessible to the practitioner.