specific radioimmunoassays for the fragment p1 of human laminin and the 7-s collagen domain of human type iv collagen were used to quantify these basement membrane proteins in second trimester amniotic fluid samples from 21 normal and 41 pathological pregnancies , the latter group being defined by elevated amniotic fluid alpha-foetoprotein ( afp ) or abnormal foetal karyotype , or both .
C0009333
collagen
C0004799
basement