Metastatic Breast Carcinoma Presenting as Perforated Appendicitis.

SUMMARY: BACKGROUND: Patients presenting with symptoms from unknown metastatic breast carcinoma are becoming increasingly uncommon. Perforated appendicitis from metastatic breast carcinoma is a rare entity with only a few published reports in the literature. CASE REPORT: The case of a 76-year-old female patient who developed perforated appendicitis from previously unknown metastatic breast cancer is presented.

Lipoyl synthase requires two equivalents of S-adenosyl-L-methionine to synthesize one equivalent of lipoic acid.

Lipoyl synthase (LipA) catalyzes the formation of the lipoyl cofactor, which is employed by several multienzyme complexes for the oxidative decarboxylation of various alpha-keto acids, as well as the cleavage of glycine into CO(2) and NH(3), with concomitant transfer of its alpha-carbon to tetrahydrofolate, generating N(5),N(10)-methylenetetrahydrofolate. In each case, the lipoyl cofactor is tethered covalently in an amide linkage to a conserved lysine residue located on a designated lipoyl-bearing subunit of the complex. Genetic and biochemical studies suggest that lipoyl synthase is a member of a newly established class of metalloenzymes that use S-adenosyl-l-methionine (AdoMet) as a source of a 5'-deoxyadenosyl radical (5'-dA(*)), which is an obligate intermediate in each reaction.