Inclusion:

1. A signed and dated IRB-approved informed consent form before any study specific screening procedures are performed.
2. Ability to read English or Spanish.
3. Men or women greater than or equal to 65 years of age on study day 1. Women must be either surgically sterile (hysterectomy and/or oophorectomy) or postmenopausal for greater than or equal to 1 year (with estradiol less than or equal to 25 pg/mL[92 pmol/L] and FSH greather than or equal to 38 mIU/mL) and must have a negative serum pregnancy test result within 48 hours before administration of test article. Women who are surgically sterile must provide documentation of the procedure by an operative report or by ultrasound.
4. Subjects should have a hemoglobin level greater than or equal to 12 g/dL at the screening visit.

Exclusion

1. Any significant unstable or uncontrolled cardiovascular, hepatic, renal, respiratory, gastrointestinal, endocrine, immunologic, dermatologic, hematologic, neurologic, or psychiatric disease.
2. History of vascular disorders (peripheral, coronary, venous), chronic inflammatory disorders (eg, rheumatoid arthritis), hematologic disorders, or bleeding disorders (eg, hemophilia, idiopathic thrombocytopenic purpura, VonWillebrand disease).
3. Presence or history of symptomatic vertigo, significant cardiac valvular disease, congestive heart failure, angina pectoris significant cardiac arrhythmia, or seizures.