Elicited cell cultures of the cactus Cephalocereus senilis produce a group of flavonoids with unsubstituted B-rings, including an aurone which represents a new class of phytoalexin. Preliminary enzymological studies indicated that the chalcone synthase (CHS) and chalcone isomerase (CHI) from cultures of C. senilis were active with cinnamoyl-CoA and 2',4',6'-trihydroxychalcone, respectively, probable intermediates for synthesis of flavonoids with unsubstituted B-rings. We now demonstrate that the cultures contain two isoforms of CHI, both of which are induced by elicitor treatment and are active with both 2',4,4',6'-tetrahydroxy- and 2',4',6'-trihydroxychalcone. (Hydroxy)-cinnamate:CoA ligase in the cactus cultures was active with cinnamic, 4-coumaric, caffeic, ferulic, and 4-methoxycinnamic acids, but not sinapic acid. A single form of CoA ligase, as resolved by chromatofocusing analysis, was active against both cinnamate and 4-coumarate. Cinnamic acid 4-hydroxylase (CA4H) activity was induced by elicitor treatment. Thus, elicited cultures contain the necessary enzymatic activities for synthesis of B-ring-hydroxy and -deoxy flavonoids. Synthesis of only the deoxy class in response to elicitation may result from some form of metabolic compartmentation through which the CA4H reaction is bypassed, leading to formation of cinnamoyl CoA which may then be incorporated into B-ring deoxy flavonoids via nondiscriminating CHS and CHI activities.
The contribution of each intercarpal joint individually and as a member of a regional group to total wrist motion was analyzed in 10 fresh, frozen cadaver specimens. Each intercarpal joint had an effect on the total wrist motion, but the contribution of each to the different planes of motion was not equal. The scaphoid-capitate joint had a governing effect on the motion of a region comprised of scaphoid-trapezium, scaphoid-trapezoid, and scaphoid-capitate. The lunate-capitate joint had a governing effect on the motion of a region comprised of the lunate-triquetrum, lunate-capitate, triquetrum-hamate, and hamate-capitate complex. Elimination of motion in either of the key governing joints affected total wrist motion the same as elimination of motion in all the joints in that region. Intercarpal fusion for treatment of ligament injury of the proximal intercarpal row may be limited to the scaphoid-capitate or lunate-capitate joint. There is no need to attempt fusion in all joints of either of the two regions.
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