Aided by the box-office success of The Da Vinci Code and rising sales in its electronics division, Sony reported Wednesday that its profits before taxes rose to $470 million during its first quarter, versus $117 million a year ago. Sony Pictures Entertainment reported a 42-percent boost in sales; however, the division wound up with a $10-million loss, attributed mostly to marketing costs for its summer releases. The company said that consumer demand for its flat-panel Bravia sets, which use LCD technology, helped move the division from an operating loss to an operating profit of $412 million.