Erin Cline Davis, Special to The Times

Trial using patient's own cells shows promise, but experts say it's too early to judge. Dallas HEXTELL looked like any other healthy toddler when he appeared on the "Today" show on March 11 -- walking, clapping, laughing, waving to his mom. But just nine months earlier, cerebral palsy had kept Dallas, now 2, from crawling, sitting up or reaching other milestones of child development...