[1] UNIV HELSINKI, DEPT CLIN CHEM, SF-00290 HELSINKI 29, FINLAND
[2] UNIV HELSINKI, DEPT IMMUNOL, SF-00290 HELSINKI 29, FINLAND
[3] UNIV HELSINKI, DEPT BACTERIOL, SF-00290 HELSINKI 29, FINLAND
[4] NICHHD, ENDOCRINOL & REPROD RES BRANCH, BETHESDA, MD 20205 USA