@article{52fa3c583d19415db73cc42a0ff63578,
title = "ANTENATAL DIAGNOSIS OF MAPLE-SYRUP-URINE DISEASE",
author = "RodyP Cox and Joel Hutzler and Joseph Dancis",
note = "Funding Information: epithelial they multiply slowly, delaying analysis. Harvesting cells with a rubber policeman, as we have usually done, is as- sociated with a variable, and frequently serious, loss of enzyme activity. The use of E.D.T.A.-trypsin to remove cells from glass surfaces seems to preserve enzyme activity in epithelial cells. We now assay cell suspensions prepared by E.D.T.A.-trypsin treatment of confluent cell monolayers. Intact cells are used because disruption of cells greatly reduces enzyme activity.{\textquoteright} The cells are incubated for 120 min with L-valine-1-14C (speci- fic activity 0-5 µCi/µmol). The evolution of 14C02 provides a measure of the decarboxylase activity and is expressed per mg protein. The simultaneous incorporation of the radioactive aminoacid into protein provides an indication of the number of cells that are assayed and their metabolic activity. The ratio of the 14CO2 to 14C-incorporation into protein is the most satis- factory approach to diagnosis, provided 14C-incorporation per mg protein indicates active cell metabolism. This study was supported by grants from the U.S. Public Health Service (AM 14528 and HD 04526) and by the Samuel A. Berger Fund.",
year = "1978",
month = jul,
day = "22",
doi = "10.1016/S0140-6736(78)91956-6",
language = "English (US)",
volume = "312",
pages = "212",
journal = "The Lancet",
issn = "0140-6736",
publisher = "Elsevier Limited",
number = "8082",
}