Major averages turned positive in early afternoon trading as leading medical stocks continued to dominate. The Dow Jones industrial average led with an 0.3% gain, while the Nasdaq picked up 0.2% and the S&P 500 0.1%. Volume was tracking higher across the board than at the same time Thursday. Economic data were light. The PMI Manufacturing Index climbed to 54.3, above January’s 53.7 and forecasts for 53.8.