A nursing degree should not hurt your chances. If you talk of it as a positive during your interviews it can actually help you! Beware, though, doctor training is totally different from nursing training. As a physician, I would count your nursing background as a positive!
As for research, it depends where you apply. If you are applying to a primary care school, your publication will help but won't be crucial. If you apply to a research powerhouse, more emphasis will be placed on your research.