{'fraction_non_alphanumeric': 0.0446521287642783, 'fraction_numerical': 0.018691588785046728, 'mean_word_length': 5.557823129251701, '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}}
Effect of structure on tumor specificity of alicyclic alpha-amino acids.

The selective affinity of [carboxyl-11C]-1-aminocyclopentanecarboxylic acid (ACPC) for tumor tissue has led us to study the tumor-localizing characteristics of a series of alicyclic alpha-amino acid analogs of ACPC. The tissue distributions of [14C]-1-aminocyclopropanecarboxylic acid, 1-aminocyclobutanecarboxylic acid (ACBC), 1-aminocyclohexanecarboxylic acid, 1-amino-2-methylcyclopentanecarboxylic acid were compared with that of ACPC in Buffalo rats bearing Morris 5123C hepatomas. ACPC and ACBC were found to have significantly higher tumor-to-nontumor concentration ratios than the other four amino acids. ACBC generally had higher tumor-to-nontumor ratios than did ACPC, significantly so for muscle, kidney, and testis and marginally so for blood. These results suggest that [carboxyl-11C]ACBC may be a better agent than [carboxyl-11C]ACPC for tumor imaging by positron tomography.