the in vitro activity and beta-lactamase stability of 7- [ d ( - ) -alpha- ( 4-ethyl-2,3-dioxopiperazino-carbonylamino ) -p-hydroxyphenylacetamido ] -3- [ ( 1-methyl ) -5-tetrazolylthiomethyl ] -delta ( 3 ) -cephem-4-carboxylic acid ( cefoperazone ) , a cephalosporin analog of piperacillin , were compared with the activities and stabilities of other cephalosporins and cephamycins .
C3536856
cephalosporins
C0007736
cephamycins