A nurse at a Tokyo hospital pleaded not guilty Monday to charges of professional negligence resulting in the death of a newborn in a controversial case involving sudden infant death syndrome and medical professionals.

Miyuki Kawashima, 33, entered the plea at the opening of her criminal trial before the Tokyo District Court.

According to the indictment, Kawashima laid 3-day-old Yusuke Inoue on his stomach at around 6 a.m. on Jan. 8, 1995, at Toho University's Ohashi Hospital in Tokyo's Meguro Ward, after he had thrown up some formula.

About 25 minutes later, she discovered he was not breathing. Hospital staff members were able to resuscitate him, but he suffered serious brain damage and died in August that year, the indictment said.

Prosecutors said inappropriate care by the nurse caused Yusuke to suffocate.