Mapping the diffusion pattern of 1O2 along DNA duplex by guanine photooxidation with an appended biphenyl photosensitizer.

To realize nucleic acid-targeting photodynamic therapy, a photosensitizer should be attached at the optimal position on a complementary oligonucleotide, where a guanine photooxidation is maximized. Here we show the photooxidation of 22 DNA duplexes with varied lengths between a 1O2-generating biphenyl photosensitizer attached at a midchain thymine in a strand and the single guanine reactant in the other strand. The best photooxidation efficiencies are achieved at 9, 10, and 21 base intervals, which coincides with the pitch of 10.5 base pairs per turn in a DNA duplex. The low efficiencies for near and far guanines are due to quenching of the biphenyl by guanine and dilution of 1O2 by diffusion, respectively. The 1O2-diffusion mapping along DNA duplex provides clues to the development of efficient and selective photosensitizer agents for nucleic acid-targeting photodynamic therapy, as well as an experimental demonstration of diffusion of a particle along cylindrical surface in molecular level.

Analysis of drug-induced liver-related adverse event trend reporting between 1997 and 2019.

AIM: This study aimed to analyze the current trends of drug-induced liver-related adverse events in the Food and Drug Administration Adverse Event Reporting System (FAERS) and Japanese Adverse Drug Event Report (JADER) databases. METHODS: The characteristics of implicated drugs were investigated by analyzing big data on drug-induced liver-related adverse events over the past 20 years in FAERS, comparing drug rankings between the JADER and FAERS databases, and calculating rankings of drugs inducing liver-related adverse events using the Medical Dictionary for Regulatory Activities Terminology. RESULTS: In the 452 272 cases registered in FAERS from 1997 to 2019, warfarin, paracetamol, and adalimumab were the drugs most related to drug-induced liver injury (DILI). In the 38 919 cases registered in JADER from 2004 to 2019, sorafenib, nivolumab, and herbal extracts were the drugs most related to DILI. No associations were found between the top 30 drugs in either of the two databases. Notably, the number of drug-induced liver-related adverse event reports and total adverse events has sharply increased in recent years. CONCLUSIONS: Although liver-related adverse events are largely caused by host immunity and other constitutional factors, differences in primary diseases, countries, and historical backgrounds lead to differences in the number of reports. Securing an appropriate database and a mechanism to collect real-time information on the frequency of adverse drug reactions is warranted.