Several segments of the medical sector contain stocks making healthy showings. Jazz Pharmaceuticals (JAZZ) made the sector's leaders list this week. With interest from mutual funds, other strong names include HCA Holdings (HCA), Universal Health Services (UHS), Celgene (CELG), Biogen Idec (BIIB), Parexel (PRXL) and MWI Veterinary Supply (MWIV). The $2 billion Fidelity Small Cap Growth started a stake in Jazz in its latest disclosure. The $3.3