Image diagnosis: Spontaneous hematoma from scurvy.

A 58-year-old alcoholic man presents with pain, swelling, and bruising of his right leg, without history of trauma or injury. He had had frequent spontaneous hematomas in his legs. This patient drank a 1.

Experimental evolution of penicillin G acylases from Escherichia coli and Proteus rettgeri.

Proteus rettgeri and Escherichia coli W were shown to express structurally different penicillin G acylases. The enzymes had similar substrate specificity but differed in molecular weight, isoelectric point, and electrophoretic mobility in polyacrylamide gels and did not antigenically cross-react. When the organisms were subjected to environmental conditions which made expression of this enzyme essential for growth, spontaneous mutants were isolated that used different amides as the only source of nitrogen.

Repression of penicillin G acylase of Proteus rettgeri by tricarboxylic acid cycle intermediates.

The regulation of the penicillin acylase in proteus rettgeri ATCC 31052 was compared with that of the enzyme in Escherichia coli ATCC 9637. Unlike the E. coli acylase, the P.