Submitted on: October 18, 1993 AIDS researcher gives upbeat report SAN FRANCISCO A leading AIDS researcher delivered an upbeat message Wednesday at the Sixth National AIDS Update Conference in San Francisco. Dr. Paul Volberding, director of the AIDS Program at San Francisco General Hospital, said the dark mood that followed last summer's international AIDS conference in Berlin has lifted. He said there had been widespread discouragement and pessimism following numerous reports of discouraging study results for what had been considered promising therapies. Now, however, the mood has recovered, and scientists are forging ahead with their research on how to stop the deadly disease with renewed enthusiasm. Of particular interest are studies of long-term survivors who have remained symptom-free five to 10 years after infection. They may provide a critical clue as to why some people remain healthy while others become deathly sick after infection.