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Background/purpose: While there are numerous reports on surgical techniques and materials for bone grafting, limited methods are available to enhance the body's inherent capacity to heal bones. Here we investigated microRNA-199a (miR-199a), a molecular that promotes osteoblast differentiation and bone healing. Materials and methods: To construct a miR-199a delivery complex, miR-199a-5p mimics were coated with mesoporous silica nanoparticles (MSNs) following modified with polyethyleneimine (PEI) and peptide WEAKLAKALAKALAKHLAKALAKALKACEA (KALA) to obtain 199a-5p-loaded MSN-PEI-KALA. Nanoparticle complexes are assessed for particle size and zeta potential using transmission electron microscopy and dynamic light scattering. Then MC3T3-E1 cells are exposed to MSN_miR-199a-5p @PEI-KALA. The impact of MSN_miR-199a-5p@PEI-KALA at varying concentrations on cell viability is assessed using Cell Counting Kit-8. Cell uptake and distribution were analyzed by double fluorescent staining with fluorescein amidite-labeled MSN_miR-199a@PEI-KALA and lysosome labeling. On day 7 after osteogenic induction, alkaline phosphatase (ALP) staining was conducted. Results: The findings indicated that the nanoparticle complexes encapsulating PEI and peptide exhibited an augmentation in both particle size and zeta potential. At a dosage of 10 μg/mL, MSN_miR-199a@PEI-KALA displayed the lowest cytotoxicity compared to the control group. MC3T3-E1 cells treated with MSN_miR-199a-5p@PEI-KALA exhibited intensified ALP staining and elevated mRNA expression levels of ALP, runt-related transcription factor 2, and osteopontin, suggesting the involvement of miR-199a-5p-loaded MSN-PEI-KALA in osteogenic differentiation. Conclusion: The successful construction of the delivering complex MSN_miR-199a@PEI-KALA in present research highlights the promise of this biomaterial carrier for the application of miRNAs in treating bone defects.

Background/purpose: Porcine collagen is widely used in regenerative therapies to generate membranes for bone augmentation. However, porcine or bovine gelatin or collagen is often not appropriate for patients with creed and religious beliefs or for allergic reasons. In this study, we evaluated the potential of fish gelatin to generate membranes. Materials and methods: Fish gelatin and hydroxyapatite (HAp) were used at three different ratios (2:0, 2:1, 2:1.5, and 2:2) to prepare gelatin-hydroxyapatite (G-HAp) membranes via freeze-drying and heat-crosslinking. The surface morphology and cell attachment of G-HAp membranes were observed using scanning electron microscopy and confocal laser microscopy. G-HAp membrane was placed at the bottom of a well plate, and MC3T3-E1 cells were seeded on it. Cell viability and cytotoxicity were tested after 1 and 3 days of culture. Alkaline phosphatase (ALP) and alizarin red staining was performed at 10 and 21 days, respectively. Results: Viability of cells on G-HAp membrane with the gelatin:HAp ratio of 2:1.5 was significantly higher than that on membranes with other gelatin:HAp ratios. ALP and alizarin red staining showed that ALP-positive areas and calcium deposition were the highest on G-HAp membrane with the gelatin:HAp ratio of 2:1. These membranes showed negligible cytotoxicity. Conclusion: Fish-derived G-HAp membranes have the potential to promote osteogenic differentiation of MC3T3-E1 cells with negligible cytotoxicity.

The optimal method for decontamination of implant surfaces for peri-implantitis treatment remains controversial. In recent years, erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and implantoplasty (IP) (i.e. mechanical modification of the implant) have been reported to be effective in decontaminating implant surfaces during the surgical treatment. Also, a lack of adequate keratinized mucosa (KM) around the implant is known to be associated with more plaque accumulation, tissue inflammation, attachment loss, and mucosal recession, increasing the risk of peri-implantitis. Therefore, free gingival graft (FGG) has been recommended for gaining adequate KM around the implant. However, the necessity of acquiring KM for the treatment of peri-implantitis using FGG remains unclear. In this report, we applied the apically positioned flap (APF) as resective surgery for peri-implantitis treatment in conjunction with IP and Er:YAG laser irradiation to polish/clean the implant surface. Furthermore, FGG was conducted simultaneously to create additional KM, which increased the tissue stability and contributed to the positive results. The two patients were 64 and 63 years old with a history of periodontitis. The removal of granulation tissue and debridement of contaminated implant surfaces were performed with Er:YAG laser irradiation post flap elevation and then modified smooth surfaces mechanically using IP. Er:YAG laser irradiation was also utilized to remove the titanium particles. In addition, we performed FGG to increase the width of KM as a vestibuloplasty. Peri-implant tissue inflammation and progressive bone resorption were not observed, and both patients maintained good oral hygiene conditions until the 1-year follow-up appointment. Bacterial analysis via high-throughput sequencing revealed proportional decreases in bacteria associated with periodontitis ( Porphyromonas , Treponema , and Fusobacterium ). To the best of our knowledge, this study is the first to describe peri-implantitis management and bacterial change before and after procedures by resective surgery combined with IP and Er:YAG laser irradiation for peri-implantitis treatment, accompanied by FGG for increasing KM around the implants.

Neuronal cell death is a key mechanism involved in the development and exacerbation of Parkinson’s disease (PD). The excessive production of reactive oxygen species (ROS) is a major cause leading to neuronal death; therefore, compounds that prevent oxidative stress-dependent neuronal death may be promising as a preventive method for PD. Ergothioneine is a natural amino acid with antioxidant properties, and its protective functions in the body are attracting attention. However, there has been no investigation into the protective functions of ergothioneine using in vivo and in vitro PD models. Thus, in this study, we analyzed the efficacy of ergothioneine against 6-hydroxydopamine (6-OHDA)-dependent neuronal cell death using immortalized hypothalamic neurons (GT1-7 cells). First, we found that ergothioneine prevents 6-OHDA-dependent neuronal cell death by suppressing ROS overproduction in GT1-7 cells. The cytoprotective effect of ergothioneine was partially abolished by verapamil, an inhibitor of OCTN1, which is involved in ergothioneine uptake. Furthermore, ergothioneine-rich Rice-koji (Ergo-koji) showed cytoprotective and antioxidant effects similar to those of ergothioneine. Taken together, these results suggest that ergothioneine or foods containing ergothioneine may be an effective method for preventing the development and progression of PD.

This study examines two aspects of trade, dependence and competition, between China and Asian countries. The study first outlines China’s evolution from a small trading nation that is highly dependent on the Soviet Union to the world’s largest trading nation with a diversified trade structure. After being dependent on the Soviet Union during the 1950s, China was dependent on Japan in terms of trade from the 1970s to the 1990s. However, during the first two decades of the 21st century, the relationship between the two countries completely changed. This study further examines bilateral trade relationships of South Korea, Taiwan, Vietnam, Malaysia, Singapore, the Philippines, Indonesia, vis-à-vis China. The study shows that Asian countries have become increasingly dependent on China in terms of trade, at the expense of trade with their conventional partners, namely Japan and the United States. Intra-ASEAN trade is also eclipsed by the growth of trade with China. Additionally, the study reveals, competition in export markets between China and Asian countries has intensified. The high-income countries in Asia have been caught up by China, while the low-income countries are also facing increasing competitive pressure from China.

Abstract Background To reveal trends in bone microarchitectural parameters with increasing spatial resolution on ultra-high-resolution computed tomography (UHRCT) in vivo and to compare its performance with that of conventional-resolution CT (CRCT) and micro-CT ex vivo. Methods We retrospectively assessed 5 tiger vertebrae ex vivo and 16 human tibiae in vivo. Seven-pattern and four-pattern resolution imaging were performed on tiger vertebra using CRCT, UHRCT, and micro-CT, and on human tibiae using UHRCT. We measured six microarchitectural parameters: volumetric bone mineral density (vBMD), trabecular bone volume fraction (bone volume/total volume, BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), and connectivity density (ConnD). Comparisons between different imaging resolutions were performed using Tukey or Dunnett T3 test. Results The vBMD, BV/TV, Tb.N, and ConnD parameters showed an increasing trend, while Tb.Sp showed a decreasing trend both ex vivo and in vivo. Ex vivo, UHRCT at the two highest resolutions (1024- and 2048-matrix imaging with 0.25-mm slice thickness) and CRCT showed significant differences (p ≤ 0.047) in vBMD (51.4 mg/cm3 and 63.5 mg/cm3 versus 20.8 mg/cm3), BV/TV (26.5% and 29.5% versus 13.8 %), Tb.N (1.3 l/mm and 1.48 l/mm versus 0.47 l/mm), and ConnD (0.52 l/mm3 and 0.74 l/mm3 versus 0.02 l/mm3, respectively). In vivo, the 512- and 1024-matrix imaging with 0.25-mm slice thickness showed significant differences in Tb.N (0.38 l/mm versus 0.67 l/mm, respectively) and ConnD (0.06 l/mm3 versus 0.22 l/mm3, respectively). Conclusions We observed characteristic trends in microarchitectural parameters and demonstrated the potential utility of applying UHRCT for microarchitectural analysis.

While there are numerous reports on surgical techniques and materials for bone grafting, limited methods are available to enhance the body's inherent capacity to heal bones. Here we investigated microRNA-199a (miR-199a), a molecular that promotes osteoblast differentiation and bone healing. To construct a miR-199a delivery complex, miR-199a-5p mimics were coated with mesoporous silica nanoparticles (MSNs) following modified with polyethyleneimine (PEI) and peptide WEAKLAKALAKALAKHLAKALAKALKACEA (KALA) to obtain 199a-5p-loaded MSN-PEI-KALA. Nanoparticle complexes are assessed for particle size and zeta potential using transmission electron microscopy and dynamic light scattering. Then MC3T3-E1 cells are exposed to MSN_miR-199a-5p @PEI-KALA. The impact of MSN_miR-199a-5p@PEI-KALA at varying concentrations on cell viability is assessed using Cell Counting Kit-8. Cell uptake and distribution were analyzed by double fluorescent staining with fluorescein amidite-labeled MSN_miR-199a@PEI-KALA and lysosome labeling. On day 7 after osteogenic induction, alkaline phosphatase (ALP) staining was conducted. The findings indicated that the nanoparticle complexes encapsulating PEI and peptide exhibited an augmentation in both particle size and zeta potential. At a dosage of 10 μg/mL, MSN_miR-199a@PEI-KALA displayed the lowest cytotoxicity compared to the control group. MC3T3-E1 cells treated with MSN_miR-199a-5p@PEI-KALA exhibited intensified ALP staining and elevated mRNA expression levels of ALP, runt-related transcription factor 2, and osteopontin, suggesting the involvement of miR-199a-5p-loaded MSN-PEI-KALA in osteogenic differentiation. The successful construction of the delivering complex MSN_miR-199a@PEI-KALA in present research highlights the promise of this biomaterial carrier for the application of miRNAs in treating bone defects. [ABSTRACT FROM AUTHOR]

The article discusses the rise and fall of the export-led industrialization model in the changing global economy, focusing on the success of Asian Newly Industrializing Economies (NIEs) like South Korea, Taiwan, Hong Kong, and Singapore. It highlights the shift in US imports of manufactured goods from Japan to other countries like China, ASEAN4, and Mexico over the years. The text also explores the impact of punitive tariffs on China and the potential for countries like South Korea, Vietnam, and India to assume China's role as major exporters to the US. The articles in the special issue offer diverse perspectives on export-led industrialization, with recommendations for strategic targeting of export industries, insights into India's growth strategy, and discussions on South Korea's economic growth model. [Extracted from the article]

Vietnam became an important exporter of cellphones after the introduction of foreign direct investments by multinational companies. Cellphones account for around 20% of Vietnam's total exports and contribute to its ability to overcome its trade deficit. However, the share of domestic value added in Vietnam's electronics industry has been declining. This study suggests that this is related to the increase in cellphones as the main export item for Vietnam. Along with the upgrading of products produced in the country, the country's electronics industry is increasingly relying on the import of parts. By decomposing Vietnam's major export items—smartphones and printers–this study reveals that parts of the latter are more technologically accessible for domestic manufacturers to supply, while most of the former's parts are beyond the technical capabilities of local manufacturers. This study suggests that when developing countries such as Vietnam consider targeting an industry to realize its latent comparative advantage, they should consider not only the possibility of gaining an advantage in the assembly of the product but also the possibility of creating backward linkages and developing ancillary industries. [ABSTRACT FROM AUTHOR]

The diagnosis of leptomeningeal metastases is sometimes difficult when the cytology of cerebrospinal fluid is negative. We report a rare case of leptomeningeal metastases that required differentiation from paraneoplastic limbic encephalitis. A 67-year-old man with extensive-stage small cell lung cancer was admitted for a sudden decrease in the level of consciousness. He suffered memory disturbances that began the day before admission. Diffusion-weighted and fluid-attenuated inversion recovery images of brain magnetic resonance imaging (MRI) showed bilateral symmetric areas of hyperintensity in the hippocampus, amygdala, insular cortex, and medial temporal lobe; contrast enhancement was positive. Cytology of the cerebrospinal fluid (CSF) was negative. Anti-N-methyl-d-aspartate receptor antibody and herpes simplex virus DNA were not detected in the CSF. Paraneoplastic Limbic encephalitis was suspected due to his symptoms and brain MRI scan. The patient developed generalized seizures after admission. High-dose methylprednisolone and intravenous immune globulin were administered, but his condition did not improve. Uncontrollable seizures persisted and he died in the hospital at day 13. Autopsy revealed leptomeningeal metastasis and invasion of cancer cells into the limbic system. Contrast-enhanced MRI should be performed even if limbic encephalitis is suspected, and leptomeningeal metastases should be suspected if the lesions are enhanced.

Euglena gracilis is a green photosynthetic microalga that swims using its flagellum. This species has been used as a model organism for over half a century to study its metabolism and the mechanisms of its behavior. The development of mass-cultivation technology has led to E. gracilis application as a feedstock in various products such as foods. Therefore, breeding of E. gracilis has been attempted to improve the productivity of this feedstock for potential industrial applications. For this purpose, a characteristic that preserves the microalgal energy e.g., reduces motility, should be added to the cultivars. The objective of this study was to verify our hypothesis that E. gracilis locomotion-defective mutants are suitable for industrial applications because they save the energy required for locomotion. To test this hypothesis, we screened for E. gracilis mutants from Fe-ion-irradiated cell suspensions and established a mutant strain, ${\mathrm{M}}_{3}^{-}$ M 3 − ZFeL, which shows defects in flagellum formation and locomotion. The mutant strain exhibits a growth rate comparable to that of the wild type when cultured under autotrophic conditions, but had a slightly slower growth under heterotrophic conditions. It also stores 1.6 times the amount of paramylon, a crystal of β-1,3-glucan, under autotrophic culture conditions, and shows a faster sedimentation compared with that of the wild type, because of the deficiency in mobility and probably the high amount of paramylon accumulation. Such characteristics make E. gracilis mutant cells suitable for cost-effective mass cultivation and harvesting.

Abstract Background Malignancies occur in approximately 1:1000 pregnancies; the most common being breast (46%) and hematological (18%) malignancies. Oral cancers account for only 2% of all cancers in pregnant women, and there are no standard guidelines for the treatment of oral cancer during pregnancy. Methods Between 2007 and 2014, our department managed 1109 patients with oral cancers; four (0.4%) had tongue carcinomas during pregnancy. These cases were retrospectively reviewed. Results The four women were aged 29–39 (median 32.5) years. Two underwent partial glossectomy at 39 and 40 weeks’ gestation, respectively, one received radiotherapy at 17 weeks’ gestation, and one underwent supraomohyoid neck dissection and hemi-glossectomy with a forearm flap reconstruction. Conclusion In addition to tumor factors, the wishes of the patient and her family, gestational age, and fetal and maternal conditions are important factors in deciding on a treatment protocol. Moreover, treatment decisions require multidisciplinary approach.

Abstract Diagnosis in cases with pulmonary lymphangitic carcinomatosis as a primary manifestation is difficult due to unawareness of the cancer. An 81‐year‐old man was admitted due to a one‐week history of dyspnoea and haemoptysis. Chest computed tomography showed diffuse bilateral ground‐grass opacity and partial consolidation. We suspected diffuse alveolar haemorrhage. High‐dose methylprednisolone and cyclophosphamide did not improve his condition and he died from respiratory failure. Autopsy revealed pulmonary lymphangitic carcinomatosis of whole lungs and primary gallbladder cancer. We should consider pulmonary lymphangitic carcinomatosis in the differential diagnosis of patients with haemoptysis and diffuse lung opacity of unknown origin.

An inflammatory fibroid polyp (IFP) is a mesenchymal tumor of the gastrointestinal tract. IFPs in the small intestine are the most frequently detected with symptoms, such as abdominal pain and tarry stool due to intussusception. Accordingly, few studies have reported jejunal IFP as a cause of occult gastrointestinal bleeding (OGIB) diagnosed via both of capsule endoscopy (CE) and double-balloon enteroscopy (DBE). A 68-year-old woman presented with a progression of anemia and a positive fecal occult blood test result. Esophagogastroduodenoscopy and total colonoscopy findings were unremarkable. CE revealed a tumor with bleeding in the jejunum. DBE also revealed a jejunal polypoid tumor. Bleeding from the tumor seemed to have caused anemia. The patient underwent partial laparoscopic resection of the jejunum, including resection of the tumor. The tumor was histopathologically diagnosed as IFP. To our knowledge, this is the first reported case of laparoscopic resection of jejunal IFP with OGIB diagnosed via CE and DBE preoperatively.

Porcine collagen is widely used in regenerative therapies to generate membranes for bone augmentation. However, porcine or bovine gelatin or collagen is often not appropriate for patients with creed and religious beliefs or for allergic reasons. In this study, we evaluated the potential of fish gelatin to generate membranes. Fish gelatin and hydroxyapatite (HAp) were used at three different ratios (2:0, 2:1, 2:1.5, and 2:2) to prepare gelatin-hydroxyapatite (G-HAp) membranes via freeze-drying and heat-crosslinking. The surface morphology and cell attachment of G-HAp membranes were observed using scanning electron microscopy and confocal laser microscopy. G-HAp membrane was placed at the bottom of a well plate, and MC3T3-E1 cells were seeded on it. Cell viability and cytotoxicity were tested after 1 and 3 days of culture. Alkaline phosphatase (ALP) and alizarin red staining was performed at 10 and 21 days, respectively. Viability of cells on G-HAp membrane with the gelatin:HAp ratio of 2:1.5 was significantly higher than that on membranes with other gelatin:HAp ratios. ALP and alizarin red staining showed that ALP-positive areas and calcium deposition were the highest on G-HAp membrane with the gelatin:HAp ratio of 2:1. These membranes showed negligible cytotoxicity. Fish-derived G-HAp membranes have the potential to promote osteogenic differentiation of MC3T3-E1 cells with negligible cytotoxicity. [ABSTRACT FROM AUTHOR]

Numb chin syndrome is a condition caused by paralysis of the mental nerve. This syndrome is characterized by numbness and loss of or decreased sensation in the lip-to-chin region. It typically occurs in malignant tumors or inflammatory diseases, and in most cases, the causative diseases are predominantly metastatic and hematopoietic tumors. Herein, we report the case of a patient with spontaneously remitted mandibular plasmablastic plasma cell myeloma (PPCM) who presented with numb chin syndrome. The patient, a man in his 76, had experienced gradual numbness extending from his left lower lip to the mental region for 4 months preceding the medical examination. We observed diffused swelling and decreased sensitivity between the left mandibular molar gingiva and adjacent buccal mucosa. This region is innervated by the left mental nerve. Clear osteolytic changes in the left mandibular branch were observed on imaging. An additional examination was performed in the Hematology Department to ensure a full-body examination. An iliac bone marrow biopsy revealed IgG-κ PPCM. Through immunohistochemical staining, we diagnosed PPCM of the mandibular lesions with a background of multiple myeloma. Despite no active treatment, spontaneous remission of the tumor was noted. PPCM occurring in the mandible is considered extremely rare. [ABSTRACT FROM AUTHOR]

Neuronal cell death is a key mechanism involved in the development and exacerbation of Parkinson's disease (PD). The excessive production of reactive oxygen species (ROS) is a major cause leading to neuronal death; therefore, compounds that prevent oxidative stress-dependent neuronal death may be promising as a preventive method for PD. Ergothioneine is a natural amino acid with antioxidant properties, and its protective functions in the body are attracting attention. However, there has been no investigation into the protective functions of ergothioneine using in vivo and in vitro PD models. Thus, in this study, we analyzed the efficacy of ergothioneine against 6-hydroxydopamine (6-OHDA)-dependent neuronal cell death using immortalized hypothalamic neurons (GT1-7 cells). First, we found that ergothioneine prevents 6-OHDA-dependent neuronal cell death by suppressing ROS overproduction in GT1-7 cells. The cytoprotective effect of ergothioneine was partially abolished by verapamil, an inhibitor of OCTN1, which is involved in ergothioneine uptake. Furthermore, ergothioneine-rich Rice-koji (Ergo-koji) showed cytoprotective and antioxidant effects similar to those of ergothioneine. Taken together, these results suggest that ergothioneine or foods containing ergothioneine may be an effective method for preventing the development and progression of PD. [ABSTRACT FROM AUTHOR]

Yoshinosuke Fukuchi,1 Koichiro Tatsumi,2 Hiromasa Inoue,3 Yukinori Sakata,4 Kai Shibata,4 Hideaki Miyagishi,4 Yasuhiro Marukawa,4 Masakazu Ichinose5 1Department of Respiratory Medicine, Graduate School of Medicine, Juntendo University, Tokyo, 2Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, 3Department of Pulmonary Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 4Eisai Co., Ltd., Tokyo, 5Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan Background/aim: Lysozyme (mucopeptide N-acetyl-muramyl hydrolase) is widely used as a mucolytic and anti-inflammatory agent in Japan. We evaluated the effects of long-term lysozyme administration on COPD exacerbation. Methods: In a 1-year, randomized, double-blind, placebo-controlled, parallel trial, patients with moderate-to-severe COPD and one or more episodes of COPD exacerbation in the previous year before enrollment were selected. Lysozyme (270 mg) or placebo was administered orally for 52 weeks as an add-on to the standard therapies such as bronchodilators. COPD exacerbation, pulmonary function, and COPD assessment test scores were analyzed. An exacerbation was defined as worsening of more than one symptom of COPD (cough, sputum volume, purulent sputum, or breathlessness) leading to a change in medication. The primary endpoint was exacerbation rate. Results: A total of 408 patients were randomly assigned to the lysozyme and placebo groups. The baseline characteristics were similar between the two groups. The exacerbation rate was not significantly different between the two groups (1.4 vs 1.2; P=0.292, Poisson regression). However, a subgroup analysis showed that lysozyme might reduce exacerbation rate in patients with airway-dominant phenotype (1.2 vs 1.6). Moreover, the median time to first exacerbation was longer in patients with airway-dominant phenotype in the lysozyme group than that in the placebo group. The levels of improvement in forced expiratory volume in 1 second and COPD assessment test scores were not statistically different between the groups, but were always greater in the lysozyme group than in the placebo group over the 52 weeks of the study. Conclusion: The effects of using lysozyme as an add-on to standard COPD therapy were not significantly different compared with placebo and were insufficient to prevent COPD exacerbation. Keywords: lysozyme, COPD exacerbation, forced expiratory volume in 1 second, COPD assessment test

Background Little is known about whether cardiopulmonary resuscitation (CPR) training can increase bystander CPR in the community or the appropriate target number of CPR trainings. Herein, we aimed to demonstrate community‐wide aggressive dissemination of CPR training and evaluate temporal trends in bystander CPR. Methods and Results We provided CPR training (45‐minute chest compression–only CPR plus automated external defibrillator use training or the conventional CPR training), targeting 16% of residents. All emergency medical service–treated out‐of‐hospital cardiac arrests of medical origin were included. Data on patients experiencing out‐of‐hospital cardiac arrest and bystander CPR quality were prospectively collected from September 2010 to December 2015. The primary outcome was the proportion of high‐quality bystander CPR. During the study period, 57 173 residents (14.7%) completed the chest compression–only CPR training and 32 423 (8.3%) completed conventional CPR training. The proportion of bystander CPR performed did not change (from 43.3% in 2010 to 42.0% in 2015; P for trend=0.915), but the proportion of high‐quality bystander CPR delivery increased from 11.7% in 2010 to 20.7% in 2015 (P for trend=0.015). The 1‐year increment was associated with high‐quality bystander CPR (adjusted odds ratio, 1.461; 95% CI, 1.055–2.024). Bystanders who previously experienced CPR training were 3.432 times (95% CI, 1.170–10.071) more likely to perform high‐quality CPR than those who did not. Conclusions We trained 23.0% of the residents in the medium‐sized city of Osaka, Japan, and demonstrated that the proportion of high‐quality CPR performed on the scene increased gradually, whereas that of bystander CPR delivered overall remained stable.