Pillar[6]arene acts as a biosensor for quantitative detection of a vitamin metabolite in crude biological samples

ビタミン代謝物を迅速定量できる超分子バイオセンサーを開発. 京都大学プレスリリース. 2020-12-09.Metabolic syndrome is associated with obesity, hypertension, and dyslipidemia, and increased cardiovascular risk. Therefore, quick and accurate measurements of specific metabolites are critical for diagnosis; however, detection methods are limited. Here we describe the synthesis of pillar[n]arenes to target 1-methylnicotinamide (1-MNA), which is one metabolite of vitamin B3 (nicotinamide) produced by the cancer-associated nicotinamide N-methyltransferase (NNMT). We found that water-soluble pillar[5]arene (P5A) forms host–guest complexes with both 1-MNA and nicotinamide, and water-soluble pillar[6]arene (P6A) selectively binds to 1-MNA at the micromolar level. P6A can be used as a “turn-off sensor” by photoinduced electron transfer (detection limit is 4.38 × 10−6 M). In our cell-free reaction, P6A is used to quantitatively monitor the activity of NNMT. Moreover, studies using NNMT-deficient mice reveal that P6A exclusively binds to 1-MNA in crude urinary samples. Our findings demonstrate that P6A can be used as a biosensor to quantify 1-MNA in crude biological samples

Risk Factors for the Development of Osteoarthritis after Anterior Cruciate Ligament Reconstruction

Background: Risk factors have been reported for osteoarthritis (OA) after anterior cruciate ligament (ACL) reconstruction, but previous studies did not include a control group, and may have included OA that would have naturally developed even in the absence of ACL injury. This study investigated risk factors compared with the patient’s own contralateral knee. M ethods:Three hundred forty-nine patients who had undergone ACL reconstruction at least 15 years previously were invited to visit the hospital. After exclusion criteria were applied, 40 patients were included in the study, including 16 with progressive OA and 24 without OA. Progressive OA was defined as OA that was more advanced on the affected side than on the contralateral side. The variables evaluated included age at the time of surgery,time from injury to surgery, sex, graft material, cartilage damage, and meniscectomy. Results:No significant differences between groups were seen in terms of age,time from injury to surgery,sex,graft material, or cartilage damage. Meniscectomy was ultimately performed significantly more frequently in the OA group (88％) than in the non-OA group (38％;p＜0.01). Conclusions:Meniscectomy was found to constitute a risk factor for the progression of OA after ACL reconstruction