Baltimore is no better or worse than any big city. Some neighborhoods should be avoided...just like every other city. 800 block west 33rd street...I would not hesitate to go here. Right near Hopkins.
I was thinking about the great hospitals, and wondering if they will ever think of picking up and going outside the city limits. Hopkins the hospital, or the college? (I think you mean hospital, as the college is just above 39th.) Hopkins’ area is still not fantastic. Neither is UM’s. I wouldn’t blame them all for picking up and moving to the county, before they get dragged down by the ghettoes.
Baltimore is worse that San Francisco and Seattle in this regard.
However, John Hopkins Hospital is surrounded by a 10’ fence topped in barbwire.
Baltimore had a murder rate of about 43/100,000 population in 2006. For comparison, the murder rate for Philadelphia and Wash. DC were in the mid 20's/100,000, and San Diego was around 5.4/100,000.
Source: www.city-data.com (great link for info on US cities)