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Biomedical subjects

J Roberts

Publications and source records attributed to J Roberts.

At least 703 records · Page 39Linked to original sources
PubMed1968

New procedures for purification of L-asparaginase with high yield from Escherichia coli.

l-Asparaginase is now known to be a potent antineoplastic agent in animals and has given complete remission in some human leukemias. Extensive clinical trials of this enzyme, however, were not possible in the past because of inadequate production of this substance. We have developed practical procedures for producing l-asparaginase in yields of sufficient quantity and purity for more extensive clinical evaluation. The nutritional requirements for optimal production of biologically active l-asparaginase by a strain of Escherichia coli have been ascertained. The highest yields of enzyme were obtained when cells were grown aerobically in a corn steep medium. Good enzyme production was associated with media containing l-glutamic acid, l-methionine, and lactic acid. The addition of glucose to the medium, however, resulted in depressed production of l-asparaginase. Sodium ion appeared to suppress l-asparaginase production. With the procedure described for isolation of biologically active l-asparaginase from E. coli, stable l-asparaginase preparations with a specific activity of 620 IU per mg of protein (1,240-fold purification with 40% total recovery) were obtained.

Antineoplastic Agents↗
PubMed1968

Mechanization of library procedures in the medium-sized medical library. IV. Physical characteristics of the acquisitions-cataloging record.

Acquisitions-Cataloging records stored on magnetic tape by the Washington University School of Medicine Library were examined to determine frequency and average length of record components and their alphabetization requirements in a book catalog. Data from this study of 4,708 records will be used in adaptation of the Library's computer-based cataloging system to greater machine capabilities. The first of these two papers compares measurements found for WUSML records with those reported in studies of conventional catalog cards. The number of sorting positions used to alphabetize entries and causes of sort failure are examined in the second paper (Number V) which will be found on page 71 of this issue of the BULLETIN.

Cataloging↗