Epidemiological Correlations Between Head and Neck Cancer and Hepatitis B Core Antibody Positivity.

BACKGROUND/AIM: Hepatitis B core (HBc) antibody positivity indicates a history of hepatitis B virus (HBV) infection and latent infection. PATIENTS AND METHODS: We conducted a retrospective case-control study of 512 and 495 head and neck cancer (HNC) and non-HNC patients treated at the Okayama University Hospital, Head and Neck Cancer Center from 2008-2017. Demographic data and risk factors that might affect HNC diagnosis were analyzed to assess their effects. RESULTS: Cancer diagnosis was found to correlate with HBc antibody positivity [odds ratio (OR)=1.50, 95% confidence interval (CI)=1.09-2.08], smoking (OR=3.03, 95%CI=2.16-4.25), and a previous history of cancer (OR=4.12, 95%CI=2.79-6.09). The HBs antigen positivity rate in both groups was very close to that observed in the general Japanese population. The HBc antibody positivity rate was very high only in the HNC group. CONCLUSION: HBc antibody positivity and HNC are epidemiologically correlated.

Establishment of the experimental procedure for prediction of conjugation capacity in mutant UGT1A1.

UDP-glucuronosyltransferase 1A1 (UGT1A1) is an enzyme that is found in the endoplasmic reticulum membrane and can reportedly have a large number of amino acid substitutions that result in the reduction of glucuronidation capacity. For example, adverse drug reactions when patients receive CPT-11 (irinotecan) such as in cancer chemotherapy are caused by amino acid substitutions in UGT1A1. We previously found that the extent of the docking when the hydroxyl residue of bilirubin was oriented toward UDP-glucuronic acid correlated with in vitro conjugation capacity. In this study, we analyzed the conformation of mutant UGT1A1s by means of structural optimization with water and lipid bilayers instead of the optimization in vacuo that we used in our previous study. We then derived a mathematical model that can predict the conjugation capacities of mutant UGT1A1s by using results of substrate docking in silico and results of in vitro analysis of glucuronidation of acetaminophen and 17ß-estradiol by UGT1A1s. This experimental procedure showed that the in silico conjugation capacities of other mutant UGT1A1s with bilirubin or SN-38 were similar to reported in vitro conjugation capacities. Our results suggest that this experimental procedure described herein can correctly predict the conjugation capacities of mutant UGT1A1s and any substrate.

Resonantlike phenomenon in short-pulse free-electron-laser oscillators with modulated desynchronism.

Recently a new method of controlling the pulse length of a short-pulse free-electron laser (FEL) has been developed. By modulating the synchronism between the optical and electron pulses in the FEL cavity, it was found that the output power and the micropulse length of the FEL beam oscillates at the modulation frequency. In this paper, we study theoretically the behavior of the micropulse length, both in the high loss (steady state) regime and the low loss (limit cycle) regime, when a modulated desynchronism is applied. In order to do this, we analyze the dynamics of a short-pulse FEL oscillator. The modulation frequency value plays an important role in the dynamics. We find that there is a resonantlike phenomenon between the externally applied desynchronism modulation and the limit cycle oscillation without modulation of a free-electron laser.