Biological & pharmaceutical bulletin最新文献

{"title":"Optimization of Infectious Disease Treatment via Clinical Practice-Based Personalized Therapy and Big Data Analysis.","authors":"Yuichi Muraki","doi":"10.1248/bpb.b26-00152","DOIUrl":"https://doi.org/10.1248/bpb.b26-00152","url":null,"abstract":"<p><p>The optimization of infectious disease treatment requires a multilevel perspective linking individualized pharmacotherapy with population-level evaluation. Clinical questions arising from bedside practices provide a starting point to improve treatment via therapeutic drug monitoring, pharmacogenomics, and pathophysiology-based dose optimization. For example, patient-specific factors, such as hepatic dysfunction and CYP3A5 genotype, substantially influence drug exposure and infection risk in transplant recipients. However, patient-level optimization alone is insufficient to determine whether antimicrobial therapy is practiced appropriately across institutions, regions, or healthcare systems. Therefore, antimicrobial surveillance systems are critical for quantifying antimicrobial use using standardized metrics and providing a measurable foundation for stewardship. In Japan, nationwide surveillance studies have enabled quantitative assessment of antimicrobial consumption and resistance patterns at both hospital and national levels. Furthermore, the increasing availability of large healthcare databases, including administrative claims data and pharmacy dispensing information, has expanded the scope of evaluation to prescribing behavior, guideline adherence, stewardship interventions, and impacts of healthcare policies. These developments allow antimicrobial stewardship to be assessed at both individual institution and national healthcare system levels. In this evolving landscape, clinical pharmacists are uniquely positioned to contribute to both individualized therapy and broader evidence generation. This review builds on our accumulated research findings and discusses how bedside clinical questions can be extended to surveillance infrastructure and big data analysis, thereby linking patient care to health policies and public health strategies against antimicrobial resistance.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 7","pages":"1043-1048"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148366848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Clinical Application of a Simultaneous Liquid Chromatography-Tandem Mass Spectrometry Method for Patients with Graft-versus-Host Disease to Quantify the Plasma Concentrations of Ruxolitinib and Posaconazole.","authors":"Masaki Kumondai, Nagomi Hayashi, Yu Sato, Daisuke Kobayashi, Ayaka Otsuki, Yugo Ueki, Yasushi Onishi, Taku Tsukamoto, Kohei Yoshikawa, Yoshihiro Hayakawa, Yuji Sato, Toshihiro Sato, Mayumi Sato, Masafumi Kikuchi, Masamitsu Maekawa, Nariyasu Mano","doi":"10.1248/bpb.b25-00646","DOIUrl":"10.1248/bpb.b25-00646","url":null,"abstract":"<p><p>Graft-versus-host disease (GVHD) is a clinically significant problem with high mortality that is gradually increasing. Ruxolitinib (RUX) is the only drug used for steroid-refractory GVHD treatment and is thereby crucial. Therapeutic drug monitoring of RUX may be effective because of the relationship between the plasma RUX concentration and treatment outcomes. Posaconazole (PCZ) has also been the recent focus of combined treatment with RUX owing to its pharmacokinetics. We established a simultaneous LC-tandem MS (LC-MS/MS) method and performed plasma drug concentration measurements and monitoring using clinical laboratory values for both RUX and PCZ. We also compared our technique to a simple LC-MS/MS method for clinical application. Moreover, the utility of the automated pretreatment LC-MS/MS (auto-LC-MS/MS) method was tested for further applications. The simultaneous quantification LC-MS/MS method satisfied analytical validation criteria under clinical conditions. Our method demonstrated linearity over the range of 0.3-500 ng/mL for RUX and 3-5000 ng/mL for PCZ, with intra- and inter-day precision and accuracy within ±15%. A possible correlation between plasma RUX concentration and kidney injury was observed in 1 of the 6 patients. Notably, plasma PCZ concentrations were decreased by changing the administration route. Moreover, the plasma concentration levels obtained using the auto-LC-MS/MS method were highly concordant with those obtained using the LC-MS/MS method. The validated LC-MS/MS method was found to be useful in clinical applications; thus, further research into its applications in clinical practice is desirable.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 2","pages":"301-309"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146200053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alteration of Fatty Acid Composition of Phospholipids in EA.hy926 Endothelial Cells Is Reflected in Microvesicles during TNF-α Stimulation.","authors":"Kenichi Ishibashi, Yuka Tanaka, Rina Kushida, Ryo Ohkita, Masaki Saito, Gen-Ichi Atsumi","doi":"10.1248/bpb.b25-00656","DOIUrl":"10.1248/bpb.b25-00656","url":null,"abstract":"<p><p>The fatty acid composition of phospholipids in the plasma membrane affects cell function; however, these findings have primarily been observed in vitro because there are no suitable tools for monitoring phospholipid fatty acid composition of the plasma membrane in vivo. In this study, we used elaidate as a trigger for altering fatty acid composition in phospholipids and determined whether such changes are reflected in microvesicles (MVs) released from the plasma membrane. Persistent exposure of the human endothelial cell line EA.hy926 to elaidate altered the intracellular fatty acid composition of phospholipids; however, the changes occurring in whole cells were not reflected in the MV fraction during the basal state. Following stimulation with tumor necrosis factor-α, elaidate-mediated alterations in fatty acid composition of the intracellular phospholipids were observed in the MV fraction. Because the alteration of fatty acid composition of intracellular phospholipids is reflected in the plasma membrane, MVs may serve as a useful tool for monitoring the phospholipid fatty acid composition of the plasma membrane under limited conditions.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 2","pages":"341-345"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146218474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Daily Medication Frequency at Which Participants Begin to Perceive Dosing as Excessive: A Questionnaire-Based Study Using the Personal Health Record Infrastructure via Electronic Medication Notebooks.","authors":"Shungo Imai, Masaki Asano, Yuri Shimizu, Hayato Kizaki, Masami Tsuchiya, Yukiko Ito, Makoto Tsuchiya, Ryoko Kuriyama, Nao Yoshida, Masanori Shimada, Takanori Sando, Tomo Ishijima, Satoko Hori","doi":"10.1248/bpb.b25-00554","DOIUrl":"10.1248/bpb.b25-00554","url":null,"abstract":"<p><p>Maintaining medication adherence remains a major clinical challenge, as higher daily dosing frequencies are often associated with decreased adherence. Although once-daily regimens are generally preferred, specific patient preferences regarding dosing frequency are unclear, despite implications for improving patient satisfaction and optimizing pharmacotherapy. Here, we evaluated the frequency at which patients begin to perceive dosing as excessive. A web-based questionnaire survey using the personal health record infrastructure of electronic medication notebooks was administered between July 20 and 26, 2023. Eligible participants were aged ≥20 years and had received oral tablets or capsules within 90 d of the survey. The questionnaire consisted of 6 items, including whether participants felt that the daily medication frequency was excessive. A multivariate logistic regression analysis was performed to identify the frequency beyond which patients perceive dosing as excessive, adjusting for confounders, such as medication formulation, number of medications, and patient characteristics. Of 1478 respondents, 1236 were included in the analysis. In total, 28.9% of participants reported that their medication frequency felt excessive. In the multivariate logistic regression analysis, twice-daily or more frequent dosing was significantly associated with the perception of excessiveness, using once-daily dosing as the reference. Twice-daily dosing is the frequency beyond which patients are significantly more likely to perceive medication as excessive. Our findings emphasize the importance of simplifying dosing regimens.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 2","pages":"267-272"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146140934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the Norepinephrine Transporter Expression and [²¹¹At]MABG Uptake with Vorinostat Preloading in the Pheochromocytoma Model.","authors":"Yasuhiro Ohshima, Ichiro Sasaki, Shigeki Watanabe, Hirofumi Hanaoka, Naoyuki Ukon, Tetsuya Sakashita, Noriko S Ishioka","doi":"10.1248/bpb.b26-00168","DOIUrl":"https://doi.org/10.1248/bpb.b26-00168","url":null,"abstract":"<p><p>Targeted α-radionuclide therapy (TAT) is a promising cancer therapy using α-emitters. However, therapeutic efficacy varies due to differences in the pharmacokinetics of TAT agents among patients. Vorinostat, a histone deacetylase inhibitor, is known to upregulate drug transporter expression, enhance the cellular uptake of β-emitting radiopharmaceuticals, and increase their antitumor efficacy. However, effective strategies or agents to enhance the tumor accumulation of TAT agents remain poorly understood. In this study, we focused on meta-[²¹¹At]At-astatobenzylguanidine ([²¹¹At]MABG) and investigated the potential utility of combining [²¹¹At]MABG with vorinostat. We evaluated protein expression of the norepinephrine transporter (NET), which is critical for the uptake of [²¹¹At]MABG, by immunoblotting in rat pheochromocytoma PC-12 cells and mouse embryonic fibroblast NIH/3T3 cells following vorinostat treatment. The synthesis of [²¹¹At]MABG was performed as previously described, and its cellular uptake was compared between vorinostat-treated and untreated cells. The cytotoxic effect was evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) staining. NET expression in PC-12 cells increased from 24 h after vorinostat treatment, reaching approximately 2.8-fold at 48 h compared to control. No change in NET expression was observed in NIH/3T3 cells after vorinostat treatment. The cellular uptake of [²¹¹At]MABG in PC-12 cells increased by approximately 1.4-fold at 24 h post-vorinostat treatment. Moreover, colony growth of PC-12 cells after 24 h exposure to [²¹¹At]MABG was significantly reduced when combined with vorinostat. In conclusion, vorinostat increased NET expression and enhanced accumulation of [²¹¹At]MABG in pheochromocytoma. In addition, the combination of vorinostat and [²¹¹At]MABG significantly enhanced cytotoxicity. These results suggest that vorinostat is potentially beneficial in optimizing [²¹¹At]MABG therapy.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 6","pages":"989-995"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148315481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Schisandrin A Suppresses Guinea Pig Ileal Longitudinal Smooth Muscle Contraction through Functional Inhibition of L-Type Ca²⁺ Channels.","authors":"Qianghaodi Hong, Tomoya Ohta, Kouharu Otsuki, Wakaba Kinami, Teppei Sato, Takashi Kikuchi, Wei Li, Kento Yoshioka, Keisuke Obara, Yoshio Tanaka","doi":"10.1248/bpb.b26-00055","DOIUrl":"10.1248/bpb.b26-00055","url":null,"abstract":"<p><p>Schisandrin A (SA), a major lignan isolated from the fruits of Schisandra chinensis, has been reported to modulate smooth muscle (SM) function in several tissues; however, its direct effects on intestinal SM have not been fully characterized. In the present study, we investigated the effects of SA on contractile responses in guinea pig (GP) ileal longitudinal smooth muscle (ILSM) and examined the involvement of L-type voltage-dependent Ca²⁺ channels (VDCCs). SA (1-100 µM) concentration-dependently inhibited contractions induced by acetylcholine (1 µM), histamine (1 µM), and prostaglandin F_2α (10 µM). These agonist-induced contractions were completely suppressed by the L-type VDCC inhibitor diltiazem (10 µM). SA also attenuated depolarization-induced contractions evoked by high-KCl (80 mM), which were similarly sensitive to diltiazem. In A7r5 vascular SM cells, high-KCl (100 mM) elicited marked increases in intracellular Ca²⁺ concentration ([Ca²⁺]_i), and these responses were substantially inhibited by SA (30 µM) as well as by diltiazem (30 µM). Furthermore, molecular docking simulations using the Ca_V1.2 channel structure (PDB ID: 8HMA) suggested that SA may interact with the tetrandrine-binding pocket, potentially forming a hydrogen bond with Tyr1508. Taken together, these findings indicate that SA suppresses intestinal SM contraction primarily by inhibiting Ca²⁺ influx through L-type VDCCs, likely via direct interaction with Ca_V1.2. This mechanism may partly underlie the traditional use of S. chinensis fruits in the treatment of gastrointestinal disorders such as diarrhea.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 4","pages":"661-665"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147637817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Trough-Only and Peak-Trough Concentration Data for the Calculation of Vancomycin Area under the Concentration-Time Curve on Day 2 Using Previous and Updated Population Pharmacokinetic Models.","authors":"Takashi Niwa, Yuto Yamada, Kazuyuki Sumi, Shino Ando, Koshi Sakaida, Rina Takenaka, Akari Nishimura, Mizuki Yamaguchi, Ayasa Goto-Fujibayashi, Koki Hara, Manami Otsubo, Ryohei Miyashita, Akio Suzuki","doi":"10.1248/bpb.b26-00196","DOIUrl":"10.1248/bpb.b26-00196","url":null,"abstract":"<p><p>Area under the concentration-time curve (AUC)-guided dosing for vancomycin requires the measurement of both peak and trough concentrations. Recently, a novel population pharmacokinetic model (Bayesian-based, free-web application PAT version 4.0) was developed. The aim of the present study was to verify whether this optimized pharmacokinetic model improved the predictive accuracy of AUC calculated using trough-only data compared to data obtained using trough and peak sampling on Day 2. We conducted a single-center, cohort study to evaluate the agreement of AUC calculated using trough-only data compared to peak-trough sampling on Day 2, and to compare results obtained with the Yasuhara (previous) and Oda (updated) pharmacokinetic models. The proportion of trough/peak-trough AUC_24-48 ratios within a 5% difference was significantly higher with the Oda model than with the Yasuhara model (75 vs. 58.3%, p = 0.034). Furthermore, multivariate logistic regression analysis showed that implementation of the Oda model was a significant factor associated with deviation of trough/peak-trough AUC_24-48 within 5% (odds ratio 2.36, 95% confidence interval, 1.05-5.05, p = 0.027). The updated model offers enhanced predictive performance for AUC_24-48 estimation using trough-only data. Further development of strategies to improve the predictive accuracy of AUC_24-48 using trough-only data is warranted.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 7","pages":"1119-1124"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148454349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Deprescribing Medications on Muscle Strength and Muscle Mass in Older Patients with Sarcopenia after Stroke.","authors":"Eiji Kose, Ayaka Matsumoto, Yoshihiro Yoshimura","doi":"10.1248/bpb.b25-00748","DOIUrl":"10.1248/bpb.b25-00748","url":null,"abstract":"<p><p>Polypharmacy is prevalent among older adults with sarcopenia and may negatively impact clinical outcomes. Although sarcopenia is associated with polypharmacy, the effect of deprescribing on muscle health in hospitalized patients with sarcopenia remains poorly understood. This study aimed to investigate the association between deprescribing during hospitalization and muscle strength and mass at discharge in sarcopenic patients after stroke. This study retrospectively analyzed data from a cohort of sarcopenic patients aged ≥65 years admitted to a convalescent rehabilitation ward after stroke. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia 2019 criteria. Deprescribing was defined as a reduction in the number of medications during hospitalization. The primary outcome was handgrip strength at discharge, and the secondary outcome was skeletal muscle mass index (SMI) at discharge. Multiple linear regression analyses were performed to examine the association between deprescribing and outcomes, adjusting for potential confounders. Of the 970 patients enrolled, 217 older patients, with a mean age of 81.8 years (males, 45.6%), were diagnosed with sarcopenia and included in the analysis. The median number of medications at admission was 5 (interquartile range 3-8), and 23.0% of patients experienced deprescribing during hospitalization. Deprescribing during hospitalization was independently associated with higher handgrip strength (β = 0.122, p = 0.009) and SMI (β = 0.138, p = 0.009) at discharge. Deprescribing was positively associated with improved muscle strength and mass at discharge in sarcopenic patients after stroke. These findings suggest that medication review and deprescribing may be beneficial strategies in the rehabilitation of sarcopenic stroke patients.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 5","pages":"770-777"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147926117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protective Effects of the Phytocannabinoid Cannabidiol on Disuse-Induced Muscle Atrophy through Modulation of Proteolysis and Mitochondrial Regulation.","authors":"Hiromasa Kato, Iori Uratsuji, Yui Nakadai, Wataru Ochiai","doi":"10.1248/bpb.b26-00020","DOIUrl":"10.1248/bpb.b26-00020","url":null,"abstract":"<p><p>Muscle atrophy induced by prolonged inactivity (disuse), including denervation-induced atrophy, is accompanied by oxidative stress, inflammation, and dysregulated protein turnover, yet no effective pharmacological therapy is currently available. Cannabidiol (CBD), a non-psychoactive phytocannabinoid derived from Cannabis sativa, has been reported to exhibit anti-inflammatory and antioxidant properties; however, its potential involvement in disuse-related muscle atrophy has not been fully characterized. In this study, to evaluate the potential effects of CBD on disuse-related muscle atrophy, we employed both in vivo and in vitro models. A mouse model of sciatic nerve resection-induced muscle atrophy was used for the in vivo experiments, while C2C12 myotubes were utilized for the in vitro analyses. In the denervated mouse model, CBD attenuated the decrease in muscle mass in the tibialis anterior and gastrocnemius muscles, as well as the decline in treadmill running performance. CBD also reduced oxidative stress and suppressed the denervation-induced upregulation of Atrogin-1 and muscle RING-finger 1 (MuRF1) proteins, as well as tumor necrosis factor-α (TNF-α) mRNA. Furthermore, CBD partially restored the decreased mitochondrial markers observed following denervation. In vitro, CBD similarly suppressed MuRF1 and Atrogin-1 protein levels and TNF-α mRNA expression in C2C12 myotubes. These findings suggest that CBD is associated with protective effects against disuse-related muscle atrophy, accompanied by reductions in oxidative stress markers, alterations in proteolytic pathways, and changes in mitochondrial-related markers. This study highlights a previously underexplored biological effect of a natural phytocannabinoid and supports further investigation of CBD as a potential supportive strategy for disuse-related muscle wasting.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 5","pages":"822-831"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147979801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors Influencing Induced Abortion in Women Aged 18-45 Years: A Nationwide Web-Based Questionnaire Survey in Japan.","authors":"Haruka Isozaki, Haruka Hattori, Yumiko Kusunoki, Nao Tagawa, Yuki Oshima, Kanae Moriya, Hiroko Takita, Hokuto Morohoshi, Kakei Ryu, Noriko Hida, Takehiko Sambe, Nahoko Shirato, Kenji Momo","doi":"10.1248/bpb.b25-00727","DOIUrl":"10.1248/bpb.b25-00727","url":null,"abstract":"<p><p>Abortion remains a significant public health concern and often results from unintended pregnancies. Although abortion rates have declined, approximately 40% are still due to unplanned pregnancies. We conducted a subanalysis of the FIKA study, a survey on sexuality among Japanese women aged 18-45 years, to examine factors correlated with abortion. We analyzed responses obtained from 3228 sexually experienced women, who were categorized based on abortion history. Sources of knowledge about intercourse and contraceptives were assessed using a standardized questionnaire. A decision tree analysis was performed to identify associated risk factors. Among the participants, 410 women (12.7%) had undergone an abortion. Women who had undergone an abortion were significantly more likely to rely on friends as a source of contraceptive information than women who had not had an abortion (p = 0.0024). Participants with abortion experience showed greater variation in knowledge about contraceptive scores, with most of them being in the lowest knowledge group. Decision tree analysis revealed two key factors: sexual debut before the age of 17 years and only compulsory education. The abortion rate was 39.5% among women with both factors, compared to 7.9% among those with none. Early sexual initiation and limited education were strongly associated with abortion experience. Reliance on informal sources may also contribute to a poor understanding of reproductive health. These findings underscore the need for early, comprehensive, and formal sex education to improve sexual literacy and reduce unintended pregnancies.</p>","PeriodicalId":8955,"journal":{"name":"Biological & pharmaceutical bulletin","volume":"49 4","pages":"753-758"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147760482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}