{'fraction_non_alphanumeric': 0.019441069258809233, 'fraction_numerical': 0.009720534629404616, 'mean_word_length': 4.802816901408451, '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}}
Bridging the gap: human diploid cell strains and the origin of AIDS.

Recent descriptions of the first human and chimpanzee cases of human immunodeficiency virus type 1 (HIV-1)-related retroviral infections dating from 1959 have stirred interest in the origin of AIDS. Although the theory of a chimpanzee origin of HIV-1 with cross-species transfer to man has now gained popularity, a more likely scenario is that chimps and humans were infected by an HIV-1 precursor virus derived from a contaminated poliovaccine. The reason for the rapidity and ease of cross-species transfer of this precursor virus has not been elucidated. We hypothesize that the poliovaccine was passaged in a human diploid cell strain. This simple manipulation allowed the retrovirus to adapt to human tissues and may have spawned the AIDS pandemic.