{'fraction_non_alphanumeric': 0.014245014245014245, 'fraction_numerical': 0.002849002849002849, 'mean_word_length': 5.570093457943925, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Cell transplantation for Parkinson's disease

Abstract Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of the dopamine producing neurons projecting from the substantia nigra into the corpus striatum. Current medical therapy is limited and cannot stop or reverse the degeneration. Over the past 30 years, attempts were made to change the course of the disease by replacing the lost neurons with grafts from various sources. Recent controlled clinical trials of fetal cell transplantation for PD have had disappointing results. These events present an opportunity to examine the past developments and future direction of cell transplantation for PD.