(Portland, OR)  --  A Portland man is charged with child abuse that left an eight-month-old baby with life threatening injuries.  Paramedics responded to a home in southwest Portland where a child was having seizures last Saturday.  Doctors determined the baby had a severe brain injury.  Police say 19-year-old Isaiah Hill told investigators he shook, squeezed and then dropped the baby on a bed.  He allegedly waited nearly half an hour to tell the child's mother the baby was seizing.  Hill faces charges of assault and criminal mistreatment.