You probably already know that most publishers do not accept PowerPoint slides as figures. When you save a PowerPoint slide as an image file, the resolution is 96 DPI by default; however publishers require 300 DPI or higher for figures. It is often a very time consuming task to recreate figures by using other graphic software, e.g., Adobe PhotoShop. The folks at Motifolio provide step-by-step instructions about how to save PowerPoint slides as 300 DPI high resolution images (.jpg, .tiff, et al) directly from PowerPoint.
You may also be interested in some free PowerPoint slides from Motifolio. The available biological and medical drawing diagrams are already inserted into PowerPoint slides. Copy/paste is all that is required for use. The graphics are transparent, color changeable, separable, and can be re-sized to any size without loss of resolution. Enjoy creating your PowerPoints!