Causal effects of denture wearing on epigenetic age acceleration and the mediating pathways: a mendelian randomization study.

BACKGROUND: The epigenetic-age acceleration (EAA) represents the difference between chronological age and epigenetic age, reflecting accelerated biological aging. Observational studies suggested that oral disorders may impact DNA methylation patterns and aging, but their causal relationship remains largely unexplored. This study aimed to investigate potential causal associations between dental traits and EAA, as well as to identify possible mediators. METHODS: Using summary statistics of genome-wide association studies of predominantly European ancestry, we conducted univariable and multivariable Mendelian randomization (MR) to estimate the overall and independent effects of ten dental traits (dentures, bleeding gums, painful gums, loose teeth, toothache, ulcers, periodontitis, number of teeth, and two measures of caries) on four EAA subtypes (GrimAge acceleration [GrimAA], PhenoAge acceleration [PhenoAA], HannumAge acceleration [HannumAA] and intrinsic EAA [IEAA]), and used two-step Mendelian randomization to evaluate twelve potential mediators of the associations. Comprehensive sensitivity analyses were used to verity the robustness, heterogeneity, and pleiotropy. RESULTS: Univariable inverse variance weighted MR analyses revealed a causal effect of dentures on greater GrimAA (ß: 2.47, 95% CI: 0.93-4.01, p = 0.002), PhenoAA (ß: 3.00, 95% CI: 1.15-4.85, p = 0.001), and HannumAA (ß: 1.96, 95% CI: 0.58-3.33, p = 0.005). In multivariable MR, the associations remained significant after adjusting for periodontitis, caries, number of teeth and bleeding gums. Three out of 12 aging risk factors were identified as mediators of the association between dentures and EAA, including body mass index, body fat percentage, and waist circumference. No evidence for reverse causality and pleiotropy were detected (p > 0.05). CONCLUSIONS: Our findings supported the causal effects of genetic liability for denture wearing on epigenetic aging, with partial mediation by obesity. More attention should be paid to the obesity-monitoring and management for slowing EAA among denture wearers.

Photoinduced Ion-Pair Inner-Sphere Electron Transfer-Reversible Addition-Fragmentation Chain Transfer Polymerization.

Photoredox-mediated reversible deactivation radical polymerization (RDRP) is a promising method of precise synthesis of polymers with diverse structures and properties. However, its mechanism mainly based on the outer-sphere electron transfer (OSET) leads to stringent requirements for an efficient photocatalyst. In this paper, the zwitterionic organoboranes [L2B]+X- are prepared and applied in reversible addition-fragmentation chain transfer (RAFT) polymerization with the photoinduced ion-pair inner-sphere electron transfer (IP-ISET) mechanism. The ion-pair electron transfer mechanism and the formation of the radical [L2B]• are supported by electron paramagnetic resonance (EPR) radical capture experiments, 1H/11B NMR spectroscopy, spectroelectrochemical spectroscopy, transient absorption spectroscopy, theoretical calculation, and photoluminescence quenching experiments. Photoluminescence quenching experiments show that when [CTA]/[[L2B]+] ≥ 0.6, it is static quenching because of the in situ formation of [L2B]+[ZCS2]-, the real catalytic species. [L2B]+[C3H7SCS2]- is synthesized, and its photoluminescence lifetime is the same as the lifetime in the static quenching experiment, indicating the formation of [L2B]+[ZCS2]- in polymerization and the IP-ISET mechanism. The matrix-assisted laser desorption ionization time-of-flight mass (MALDI-TOF MS) spectra show that the structure of [C3H7SCS2] was incorporated into the polymer, indicating that ion-pair electron transfer occurs in catalytic species. The polymerization shows high catalytic activity at ppb catalyst loading, a wide range of monomers, excellent tolerance in the presence of 5 mol % phenolic inhibitors, and the synthesis of ultrahigh-molecular-weight polymers. This protocol with the IP-ISET mechanism exhibits a value in the development of new organic transformations and polymerization methods.

[Long-term effect observation after 10 years of tonsillotomy （Histological analysis of one case of secondary operation）].

Objective:To investigate the long-term effect of partial tonsillectomy in children with tonsil hypertrophy. Methods:A total of 146 children with obstructive sleep apnea（OSA） who received surgical treatment for tonsil hyperplasia from January 2010 to January 2013 were selected and divided into the observation group（n=69） and the control group（n=77）. The observation group was received tonsillotomy（TT）, and the control group was received total tonsillectomy（TE）. Parental satisfaction and OSA quality of life questionnaire for children（OSA-18） were surveyed. Residual tonsil size was measured, and polysomnography（PSG） was monitored after 10 years. HE and immunohistochemical analysis were performed on tonsil tissues of one patient who performed a second operation after TT in 2017 year. Results:The results of questionnaire survey showed that the symptoms of respiratory obstruction were significantly improved in both groups, and the satisfaction of TT group was higher than that in the TE group. No increase in the number of respiratory tract infections was observed in all patients. In the TT group, nine cases（13.04%） had tonsil hyperplasia toⅡ°, and the remaining patients had tonsil hyperplasia to Ⅰ°. In addition, one case hadtonsil suppurative infection at the 14th month after surgery, and no recurrence or reoperation was found after treatment. There were seven cases in the TT group and eight cases in the TE group with occasional snoring and mouth breathing after surgery, but the PSG examination of the patients did not meet the diagnosis of OSA. The main causes were obesity and allergic rhinitis. Compared with the first operation, the cicatricial obstruction and infection of tonsil tissue in the second operation were not significantly changed, and the immunohistochemical results also demonstrated that the expression of CD20 was not changed, and the expression of CD3 was decreased. Conclusion:Both TT and TE can effectively improve the symptoms of OSA obstruction in children. TT has less trauma, less postoperative pain, faster recovery and lower rate of hyperplasia, which can be used as one of the main methods for the treatment of tonsil hypertrophy in children.