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Biomedical subjects

L J Hanka

Publications and source records attributed to L J Hanka.

30 records · Page 2Linked to original sources
PubMed1969

Biological studies with alpha-dehydrobiotin.

A growing culture of Streptomyces lydicus converted biotin-(14)C to alpha-dehydrobiotin-(14)C. The conversion was demonstrated by isolating crystalline alpha-dehydrobiotin-(14)C from fermentation liquors supplemented with biotin-(14)C. The addition of pimelic acid-(14)C to the growing culture did not produce any radioactive alpha-dehydrobiotin. alpha-Dehydrobiotin did not substitute for biotin in Lactobacillus plantarum or in Saccharomyces cerevisiae. Antimicrobial activity of alpha-dehydrobiotin was abolished by avidin. alpha-Dehydrobiotin appears to be different from several biotin vitamers described in the literature. It is concluded that alpha-dehydrobiotin is a product of biotin catabolism in S. lydicus.

Biotin↗
PubMedDate not supplied

Enhancement by tetrahydrouridine (NSC-112907) of the oral activity of 5-azacytidine (NSC-102816) in L1210 leukemic mice.

5-Azacytidine is more active when administered parenterally than orally in the treatment of L1210 leukemic mice. Oral coadministration of tetrahydrouridine, a pyrimidine nucleoside deaminase inhibitor with no intrinsic antitumor activity, greatly increases the oral activity of 5-azacytidine. 5-azacytidine (or cytotoxic equivalent) blood levels in BDF mice are much higher after oral administration of the 5-azacytidine-tetrahydrouridine combination than when 5-azacytidine is administered alone by the same route. The therapeutic results (L1210 leukemia) achieved with the oral combination are similar to those observed with parenteral 5-azacytidine alone.

Administration, Oral↗