Vampiric - how does it work?

I've picked up a vampiric sword hilt that has life stealing (1) and health regeneration (-1). Can someone clarify exactly what this means? I take it whenever the sword with the vampiric upgrade is equipped, I just regen health slower, not actually *lose* health? And for life-stealing, does that imply I get a single point every time I hit something, or a point of health per point of damage I do?

m19

u dont regen health at all
u lose hp when u carry that sword and are out of town.
and every time u make a successful hit on a monster u gain 1 hp.

And I saw a Ranger quickly destroy a Dune Burrower with a Vampiric Bow almost single handed.