RÉSUMÉ
Although research has established social participation as important for preventing frailty in older people, the association between the type and frequency of social participation and comprehensive frailty remains unclear. This study aimed to reveal the associations between types and frequency of social participation and comprehensive frailty among community-dwelling older people. This was a cross-sectional study conducted in four cities and towns (Inabe City, Nabari City, Odai Town, and Kiho Town) of Mie Prefecture, Japan, among adults who were: (i) aged ≥65 years and (ii) not certified as needing long-term care. We measured comprehensive frailty using the participants' total scores on the Kihon Checklist, developed by Ministry of Health, Labour and Welfare of Japan, which divides frailty status into three categories: robust (0-3 points), prefrail (4-7), and frail (8-25). Types and frequency of social participation were explanatory variables, and ordered logistic regression analysis adjusted for potential confounding factors identified the associations. The frailty status of the 296 participants (age 65-74 years: 44.3 %; female: 74.0 %) was as follows: frail, 21.3 %; prefrail, 40.2 %; and robust, 38.5 %. Lower level of frailty was associated with interaction using smartphones 2-3 times per month, participating in sports ≥4 times per week, participating in local improvement activities several times per year, and engaging in activities for children 2-4 times per month. Social participation among older adults at appropriate frequencies were associated with the lower level of comprehensive frailty. However, future longitudinal studies are needed using populations from more diverse countries or regions and from different cultures.
RÉSUMÉ
BACKGROUND: We previously demonstrated that heme oxygenase-1 (HO-1) induction may contribute to a protective response against photodynamic therapy (PDT) using talaporfin sodium (TS) in rat malignant meningioma KMY-J cells. In the present study, we examined the mechanism of HO-1 induction by PDT with TS (TS-PDT) in KMY-J cells. METHODS: KMY-J cells were incubated with 25 µM TS for 2 h and then exposed to 664 nm diode laser irradiation at 1 J/cm2. The gene and protein expression levels of HO-1 and hypoxia-inducible factor-1α (HIF-1α) were determined by real-time RT-PCR and western blot analysis, respectively. Cell viability was measured using the cell counting kit-8 assay. RESULTS: mRNA and protein levels of HO-1 in KMY-J cells were increased significantly at 3, 6, and 9 h after laser irradiation and the increased mRNA level of HO-1 was decreased by antioxidant N-acetyl cysteine treatment. The protein level of HIF-1α, which mediates transcriptional activation of the HO-1 gene, was increased significantly at 1 h after laser irradiation. Additionally, induction of mRNA expression of HO-1 by TS-PDT was diminished by HIF-1α inhibitor echinomycin. We also demonstrated that echinomycin significantly augmented the cytotoxic effect of TS-PDT. CONCLUSIONS: Our findings indicate that TS-PDT may induce HO-1 expression via reactive oxygen species production and then HIF-1 pathway activation in KMY-J cells, and the HO-1 induction may cause attenuation of the therapeutic effect of TS-PDT.
