BAGHDAD Shortly before 1 a.m. Thursday, there was a desperate wail at the back gate of B Companys compound in Sadr City. A woman had been badly burned and her relatives were begging for help. With little in the way of emergency services and travel hampered by blocked streets, nightly curfews and sporadic firefights, a steady trickle of Iraqis has been turning to the American soldiers here for medical care. Medics who have trained for combat have attended to a seizure victim, an infant brought in by an anxious father and a boy wounded by gunfire. On Thursday, they... ...