The Food and Drug Administration (FDA) is ramping up its efforts to curtail youth use of e-cigarettes — and demanding answers from some of the companies that make them. The FDA on Thursday announced that official requests for information were sent to five e-cigarette manufacturers: J Well, for Bo Starter Kit; YGT Investment LLC and 7 Daze LLC, for Zoor Kit; Liquid Filling Solutions LLC, for Myle Products; and SVR Inc., for SMPO Kit.