Though I can't recall any specific examples, I've heard that the experiments carried out in Nazi Germany added significantly to the scientific literature about what happens to the human body under extreme conditions.

... and since scientific results obtained in any way are good enough, US and russians were very happy to get their hands on Nazi "research" done in concentration camps. It was basically slow torture to death usually caused by infections from really twisted experiments, ie sewing in "patient" hay and observing him die slowly over weeks, without helping.

some would say once experiments were done and over, there isn't much that can be done to countless victims. albeit true, using these further gives some sort of approval on all of it (ie becessary evil BS).