Nassau County Legislator Dave Mejias (D-North Massapequa) will be hosting a blood drive to replenish the dwindling blood supply as well as a bone marrow screening program to help find donors for the tens of thousands of people desperately in need of a transplant of marrow, the tissue inside bones that produces blood cells.  Most people in need of a transplant suffer from leukemia or other blood diseases such as Aplastic Anemia, which is life-threatening. The bone marrow drive will also be screening for a donor for Aixa Brea, 32, who is Dominican, and in desperate need of a transplant from a donor with a similar genetic makeup.  Ms. Brea, who is engaged to be married to her fiancé John Moynihan, a longtime member of the NYPD, hopes to find a donor but also wants to build up the bank for other people.  People of Hispanic or Latino descent are encouraged to get screened since Hispanics number only 400,000 of the 5.5 million registered donors in the National Marrow Donor Program.  Please come down!  For more information on the National Marrow Donor Program, please call 1-800-747-2820 or visit www.marrow.org <http://www.marrow.org/> .