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Biomedical subjects

C Hayashi

Publications and source records attributed to C Hayashi.

At least 109 records · Page 6Linked to original sources
PubMed1981

Continuous-flow enzymic determination of creatine in urine.

A new enzymic method is described for the determination of creatine in urine by continuous-flow analysis. The measurement is accomplished by transforming creatine to formaldehyde in reactions catalyzed by creatinase (creatine amidinohydrolase) and sarcosine dehydrogenase. The formaldehyde is reacted with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to form a purple product, which is measured colorimetrically. The method gives a linear standard curve for creatine concentrations up to 100 mg/L. Precision and analytical recovery are excellent, and results correlate well with those by the more-difficult Folin method, which currently is most often used for this analysis.

Autoanalysis↗
PubMed1980

A novel immunization procedure involving pretreatment with cross-reacting steroid conjugated to a copolymer of D-glutamic acid and D-lysine for production of low cross-reactive antisera.

Anti-testosterone and anti-5 alpha-dihydrotestosterone antisera have been produced by pretreatment of mice with a cross-reacting steroid coupled to a copolymer of D-glutamic acid and D-lysine to inhibit production of cross-reacting antibodies before immunization with the specific steroid conjugated to a protein. 15 beta-Carboxyethylmercapto derivatives were used as haptens. The cross-reactivities of the anti-testosterone and anti-5 alpha-dihydrotestosterone antisera with 5 alpha-dihydrotestosterone and with testosterone were 0.49 and 13.5%, respectively.

Animals↗
PubMed1980

Enzyme immunoassay of hepatitis B surface antigen with use of the "Hepanostika" test kit and a new photometer, "Photo-Elisa 1".

We describe an enzyme immunoassay for hepatitis B surface antigen, with use of a Hepanostika test kit and "Photo-Elisa 1," a photometer capable of measuring small quantities of test material. Because the length of the optical path in the "Photo-Elisa 1" is only 1.2 mm, volumes as small as 15 micro L can be can be measured. Accuracy is enhanced through cancellation of background absorbance by measurement at two wavelengths. Results obtained with the kit compare well with those by radioimmunoassay. By substituting photometric reading for visual reading, Hepanostika provides a more nearly accurate screening test.

Enzyme-Linked Immunosorbent Assay↗