Abstract: A surgical instrument includes a rotatable electrical coupling assembly having a first part and a second part that electrically couple and rotate relative to each other. The second part is carried by and rotates with a tube collar coupled to a transducer. A portion of the transducer is inserted through an aperture of the second part, but does not contact the second part. The first part of the assembly may electrically couple to the second part via pogo pins, brush contacts, or ball bearings. Alternatively, the first part may comprise conductive channels formed in the casing. The second part may comprise a rotatable drum with a conductive trace. In some versions, one or more components may comprise MID components. In another version, the rotatable electrical coupling assembly comprises a rotatable PC board and brush contact. Further still, a circuit board may be provided with the transducer inside a transducer casing.

Abstract: A process for recovering highly pure, recombinant IL-2 from transformed microorganisms in which the cells are disrupted; impure recombinant IL-2 is isolated in the form of refractile bodies from the disruptate; the impure IL-2 is dissolved and denatured with at least 6M guanidine hydrochloride containing a reducing agent; the reduced IL-2 is precipitated and resolubilized; the reduced solubilized IL-2 therein is oxidized by a controlled oxidation; the oxidized IL-2 is refolded by reducing the concentration of guanidine hydrochloride in the solution; and the oxidized, refolded IL-2 is further purified by ion exchange chromatography or hydrophobic interaction chromatography and ion exchange chromatography.