Study of Purified Umbilical Cord Blood CD34+ Stem Cell on Chronic Ischemic Stroke

Inclusion Criteria: 1. Subjects can be of either gender and must be between 35 through 75 years of age. 2. Subjects must have had ischemic stroke more than 6 and less than 60 months ago. 3. Subjects must have stable hemiplegia or hemiparesis condition at least for 3 months. 4. Subjects must have stroke-induced clinical deficits affecting motor, perceptual, or language functions, with a National Institutes of Health Stroke Scale (NIHSS) of 5-15. 5. Subjects must have stroke in the middle cerebral artery territory. 6. Subjects must have an available umbilical cord blood unit that has an HLA-match of at least 5:6 (HLA-A, -B, and -DR). 7. Subjects must be able to read and understand the informed consent form that has been approved by the appropriate Institutional Review Board (IRB). The subject must sign and date the informed consent form before any study-specific procedures. (Note: If a subject consents to participation but is not in a position to sign and date the informed consent form personally because of his or her physical conditions, the consent form must be confirmed orally at the time of consent, marked or finger printed by the subject voluntarily). The informed consent procedure must be observed by an independent witness who is present throughout the whole informed consent process and sign the consent form. Exclusion Criteria: 1. Subject has evidence of a non-ischemic mechanism, subarachnoid hemorrhage, primary intracerebral or intraventricular hemorrhage or MRI has shown that the occlusion is not in the middle cerebral artery territory. 2. Pregnant or lactating women. 3. History of alcohol or drug abuse in the previous 3 months. 4. Subjects must not have the following conditions in documents: * significant renal, cardiovascular, hepatic, or psychiatric disease * abnormal blood coagulation parameters, * immunodeficiency (e.g. AIDS) * tumors, leukemia, and other cancer that may interfere with the clinical trial protocol * infectious diseases, including hepatitis, or other conditions that may be a contraindication to the planned therapies and evaluation. 5. Subject must not be currently participating in another investigational study or taking any investigational drug within the last four weeks before the screening of this study. 6. Any other condition that, in the opinion of the investigator, suggests that the subject would not be compliant with the study protocol and would not be suitable to perform a surgery or to participate in the study.