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Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 451 records · Page 25Linked to original sources
PubMed1978

Nutritional improvement of food proteins by means of the plastein reaction and its novel modification.

The paper reviews recent studies in the application of the plastein reaction for the improvement of amino acid compositions of food proteins; it describes in a large measure the specific incorporation of amino acid esters into protein hydrolysate during the plastein reaction with papain. The information obtained from this specificity study has been found useful in the improvement of several unconventional as well as conventional proteins by incorporating controlled amounts of essential amino acids through the plastein reaction. Prior to carrying out this reaction, however, it is necessary to prepare a protein hydrolysate as its substrate. The entire process thus requires two independent steps: enzymatic protein hydrolysis and resynthesis. In very recent work we have found it possible to incorporate amino acid esters directly into protein by one step when a proper reaction condition has been adopted. This novel "one--step process" is also discussed in comparison with the conventional plastein reaction.

Amino Acids↗
PubMed1978

Spontaneous regression of syngeneic transplanted tumors in rats pretreated with the antileukemia drug busulfan.

Lethal growth of a syngeneic transplanted tumor (KMT-17) was inhibited in WKA rats pretreated with the antileukemia drug busulfan. The effect of busulfan was short-lasting, and administration of the drug after tumor challenge had little effect on the lethal growth of the tumor. After spontaneous regression of the tumor in rats pretreated with busulfan, specific transplantation resistance to identical tumor was acquired. Busulfan did not exhibit its effect in rats irradiated before tumor challenge. As shown by the Winn test, spleen cells from rats immunized with inactivated tumor cells after busulfan treatment inhibited growth of admixed tumor cells more strongly than did spleen cells from rats immunized without busulfan treatment. Enhancement of immune response to tumor cells rather than tumoricidal activity by busulfan was suggested.

Animals↗