Shinya Nishi

cDNA cloning of the mammalian sterol C5-desaturase and the expression in yeast mutant.

Sterol C5-desaturase (SC5D) cDNA is an enzyme that catalyzes the dehydrogenation to introduce C5-6 double bond into lathosterol in cholesterol biosynthesis. We have isolated and sequenced the cDNA clones encoding human and mouse SC5D. The functional complementation of a defective yeast mutant proves that the human and mouse cDNA clones encode SC5D. Mammalian SC5D was presumed as an integral membrane protein containing histidine residues conserved also in yeasts and plant.

Complete hydatidiform mole with coexisting dichorionic diamniotic twins following testicular sperm extraction and intracytoplasmic sperm injection

We present the first report of complete hydatidiform mole (HM) with coexisting dichorionic diamniotic twins. This pregnancy was achieved after testicular sperm extraction and intracytoplasmic sperm injection (ICSI) for azoospermia in the womans husband. Standard in vitro fertilization may cause multisperm fertilization and increase triploid partial HM and complete HM, which arise from dispermic fertilization. In contrast, ICSI can avoid multisperm fertilization. In our case, paternal isodisomy in the molar tissue was confirmed by microsatellite analysis suggesting that it resulted from duplication of a haploid paternal genome following monospermic fertilization of an inactivated oocyte or from monospermic fertilization of an inactivated oocyte with a diploid sperm. Although the patient was eager to continue the pregnancy, the size of the HM component increased rapidly and termination of the pregnancy was required for pre‐eclampsia‐like symptoms at 15 weeks of gestation. After the operation, chemotherapy was initiated for persistent trophoblastic disease.