1) Your Master's credit hours might be counted toward the 90 hour requirement if they are in one of the 4 (Biology, Physics, General Chem and/or Organic Chem) subjects. Example: if you got your MS in Biology, they may substitute a Molecular Biology course for one of your General Bio courses. Similarly, if you did a thesis, they may even waive the lab requirement for Biology.
2) Since your undergrad is from a foreign institution, you have to do all of your pre-reqs, including lab barring those that you might have done in your Master's.
3) For >90% of the schools, you require a permanent resident card at the time of application.
4) Always call the schools that you are applying to individually, each school has different policies and different levels of tolerances.
5) There are a few schools that do not accept students that did not go to high school or did not get their undergrad from a US institution. Save yourself some $, do your homework, and do not apply to those. Example: Mayo. But they are an exception, not the norm
6) Any other questions, feel free to PM me before next week, M2 continues from next Monday, and it is very unlikely that I will respond in a timely fashion.