Background: Cancer cell line-derived feeder cells enhance natural killer (NK) cell expansion; however, concerns regarding viable residual feeder cells in the final product limit their use. Evidence supporting the safety of NK-sensitive K562-based feeders, even when irradiated, is scarce. We optimized an NK cell expansion protocol using genetically engineered K562-mbIL-18/-21 (GE-K562) feeder cells and clinical-grade media and confirmed the absence of residual feeder cells. Methods: NK cell expansion efficiency was compared between feeder-free and feederbased systems using CTS NK-Xpander Medium. To achieve optimal NK expansion, various peripheral blood mononuclear cell (PBMC)-to-feeder ratios and re-stimulation frequencies were tested over 21 days. Flow cytometry and BCR::ABL1 quantitative reverse transcription PCR (RT-qPCR) were used to confirm the absence of feeder cells in the final NK cell product. Results: Feeder-based systems showed superior NK cell fold expansion compared with that of feeder-free systems. Among feeder-based conditions, NK cells expanded 5,224-fold at a 2:1 PBMC-to-feeder ratio after 3 weeks, relative to 1,450-fold at a 6:1 ratio (P < 0.05).Re-stimulation on days 7 and 14 further increased expansion up to 261,457-fold. Irradiated feeder cells showed no proliferation and were eliminated within 3–6 days. On day 21, flow cytometry and BCR::ABL1 RT-qPCR results confirmed the absence of residual feeder cells. Conclusions Our optimized NK cell expansion protocol using irradiated GE-K562 feeder cells and clinical-grade media offers a safe and scalable approach to generating large numbers of NK cells, supporting its potential use in clinical immunotherapy applications.

Purpose: Immune checkpoint inhibitor plus chemotherapy is the standard first-line treatment for advanced gastric cancer; however, predictive biomarkers for optimal patient selection remain unsatisfactory. This study was aimed at evaluating the predictive value of tumor mutational burden (TMB) and insertion/deletion (Indel) rate in patients with gastric cancer treated with nivolumab plus chemotherapy. Materials and Methods: This retrospective study included 132 patients with gastric cancer treated with first-line nivolumab plus chemotherapy and 185 patients treated with chemotherapy alone, all of whom had next-generation sequencing data available. The TMB and Indel cut-offs were set at 15.63 mutations per megabase and 18.19%, respectively, as determined based on their ability to best distinguish progression-free survival (PFS) among the patients who received nivolumab plus chemotherapy. Results: PFS was favorable for nivolumab and chemotherapy than for chemotherapy alone in both the high and low TMB groups; nevertheless, survival benefits were observed only in the high Indel group. Among the subgroups defined based on both TMB and Indel rates, the high TMB and high Indel rate subgroup showed the greatest benefit from nivolumab plus chemotherapy compared with that from chemotherapy alone. The benefit of this subgroup remained significant in patients with proficient mismatch repair (MMR) tumors, whose survival outcomes were comparable to those of patients with deficient MMR tumors.Among patients treated with nivolumab plus chemotherapy, high TMB and Indel rate were independently associated with favorable survival outcomes. Conclusions Thus, Indel rate, particularly in combination with TMB, may be a promising predictive biomarker for gastric cancer. However, further validation of their predictive value is warranted.

The gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the gastrointestinal tract. Between the 1990s and early 2000s, GIST was identified as a tumor characterized by KIT or PDGFRA mutations, resulting in imatinib being established as an effective targeted therapy. However, with advances in molecular diagnostics, approximately 10%–15% of GISTs have been reported to harbor alternative mutations, such as those in the succinate dehydrogenase subunit genes and BRAF, leading to the development of additional targeted therapies. GISTs exhibit a wide spectrum of clinical behaviors, ranging from indolent to highly aggressive, prompting the development of diverse risk classification systems. However, multiple systems remain in use, leading to inconsistent pathologic reports. Moreover, the mitotic counting method—a key factor in risk stratification—has become a major source of confusion among pathologists owing to the adoption of digital pathology and discrepancies between updated international guidelines and outdated reimbursement requirements. These inconsistencies have hindered pathologic reporting and communication between pathologists and clinicians. This review comprehensively overviews the historical background, molecular subtypes, and risk classification systems of GIST, focusing on evolving issues in mitotic rate evaluation and the application of risk classification systems in clinical practice.

Although venous invasion (VI) is associated with distant metastasis and observed in >50% of pT2–4 colorectal cancers (CRCs), the role of VI in pT1 CRCs is not well-defined. Methods: Thirty-four surgically resected pT1 CRCs were reevaluated for 2-dimensional (2D) VI using hematoxylin and eosin (H&E)–stained slides with additional elastic and desmin immunohistochemical staining (cohort A). Additionally, 27 pT1 CRCs without knowing VI status were selected for 3-dimensional (3D) VI evaluation only (cohort B). All 61 cases (cohorts A and B) were studied in 3D using tissue clearing. Results: VI was detected more commonly in 3D (17/34, 50.0%) than in 2D H&E slide evaluation (9/34, 26.5%, p = .047). When VI was identified in 3D (27/61, 44.3%), the most common phase was that of intraluminal growth (22/27, 81.5%), followed by intravasation (7/27, 25.9%) and extravasation (5/27, 18.5%). E-cadherin expression was characterized in 3D in foci of VI and varied in each phase of invasion. Conclusions: All three phases were observed in VI of pT1 CRCs. The extravasation of neoplastic cells from foci of VI in pT1 CRC suggests that VI could be a route of intratumoral spreading in a subset of pT1 CRCs.

Myopia has reached epidemic proportions globally, with a prevalence exceeding 80–90% among young adults in East Asia. This public health crisis has catalyzed the development of artificial intelligence (AI) applications to transform myopia management from reactive correction to predictive precision prevention. This review synthesizes the advances in AI applications across the myopia management continuum, encompassing risk prediction, automated monitoring, and clinical decision support systems (CDSS). Emphasis is placed on contributions from high-prevalence regions. We conducted a comprehensive PubMed literature search for studies published between 2018 and 2025 using the terms “myopia,” “artificial intelligence,” “machine learning,” “deep learning,” and “clinical decision support.” These studies demonstrated that deep learning systems achieve areas under the receiver operating characteristic curve exceeding 0.95 for pathologic myopia detection and up to 0.97–0.98 for 5-year high myopia risk prediction in early longitudinal cohorts. Self-supervised foundation models (RETFound) enable few-shot learning for rare complications with limited labeled data. Vision transformers outperform conventional convolutional neural networks in detecting subtle lesions such as lacquer cracks. Time-series transformers (Informer, TimesNet) demonstrate 8–12% improvements in long-term refractive prediction relative to long-short term memory architectures. Federated learning frameworks enable privacy-preserving multi-institutional collaboration. AI-guided interventions reduce the incidence of high myopia by 17.8% in simulated trials. AI has achieved expert-level performance in myopia detection, risk prediction, and progression forecasting. The convergence of foundation models, federated learning, and closed-loop management ecosystems signal a pivotal era for precision myopia care; however, real-world clinical trials and cross-ethnic validation are essential before widespread deployment.

Objective: We examined sociobehavioural factors associated with SARS-CoV-2 infection and estimated COVID-19 vaccine effectiveness against symptomatic SARS-CoV-2 infection in the Philippines. Such studies are limited in low- and middle-income countries, especially in Asia and the Pacific. Methods: A case-control study was conducted in two hospitals in Manila, Philippines, from March 2022 to June 2023. Sociobehavioural factors and vaccination history were collected. PCR-positive individuals were cases, while PCR-negative individuals were controls. Adjusted odds ratios (aORs) were calculated to examine associations between sociobehavioural factors/vaccination and medically attended SARS-CoV-2 infection. Results: The analysis included 2489 individuals (574 positive cases, 23.1%; 1915 controls, 76.9%; median age [interquartile range]: 35 [27–51] years). Although education and household income were not associated with infection, being a health-care worker was (aOR: 1.45; 95% confidence interval [CI]: 1.03–2.06). The odds of infection were higher among individuals who attended gatherings of five or more people compared to those who attended smaller gatherings (aOR: 2.58; 95% CI: 1.14–5.83). Absolute vaccine effectiveness for vaccination status was not estimated due to a high risk of bias, for example, unascertained prior infection. Moderate relative vaccine effectiveness for the first booster (32%; 95% CI: -120–79) and the second booster (48%; 95% CI: -23–78) were observed (both with wide CI), albeit with a waning trend after half a year. Discussion: The higher odds of infection among health-care workers emphasize the importance of infection prevention and control measures. Moderate relative vaccine effectiveness with a waning trend reiterates the need for more efficacious vaccines against symptomatic infection caused by circulating variants and with longer duration of protection.

Objectives: Developing large language models (LLMs) in biomedicine requires access to high-quality training and alignment tuning datasets. However, publicly available Korean medical preference datasets are scarce, hindering the advancement of Korean medical LLMs. This study constructs and evaluates the efficacy of the Korean Medical Preference Dataset (KoMeP), an alignment tuning dataset constructed with an automated pipeline, minimizing the high costs of human annotation. Methods: KoMeP was generated using the DAHL score, an automated hallucination evaluation metric. Five LLMs (Dolly-v2-3B, MPT-7B, GPT-4o, Qwen-2-7B, Llama-3-8B) produced responses to 8,573 biomedical examination questions, from which 5,551 preference pairs were extracted. Each pair consisted of a “chosen” response and a “rejected” response, as determined by their DAHL scores. The dataset was evaluated when trained through two different alignment tuning methods, direct preference optimization (DPO) and odds ratio preference optimization (ORPO) respectively across five different models. The KorMedMCQA benchmark was employed to assess the effectiveness of alignment tuning. Results: Models trained with DPO consistently improved KorMedMCQA performance; notably, Llama-3.1-8B showed a 43.96% increase. In contrast, ORPO training produced inconsistent results. Additionally, English-to-Korean transfer learning proved effective, particularly for English-centric models like Gemma-2, whereas Korean-to-English transfer learning achieved limited success. Instruction tuning with KoMeP yielded mixed outcomes, which suggests challenges in dataset formatting. Conclusions KoMeP is the first publicly available Korean medical preference dataset and significantly improves alignment tuning performance in LLMs. The DPO method outperforms ORPO in alignment tuning. Future work should focus on expanding KoMeP, developing a Korean-native dataset, and refining alignment tuning methods to produce safer and more reliable Korean medical LLMs.

Thelazia callipaeda (Spirurida, Thelaziidae), a parasitic eye worm causing thelaziasis has been reported in humans and dogs in Korea. However, its occurrence in other potential reservoir hosts, including wild animals, remains unclear. In the present study, we described the 2 cases of thelaziasis from both of feral and captive wild animal in Korea. In August and November 2017, 2 cases of the parasitic infections were found in the third eyelid of rescued leopard cat Prionailurus bengalensis and reared raccoon dog Nyctereutes procyonoides at the Chungnam Wild Animal Rescue Center. A total of 20 and 24 worms were detected from the left and right eyes of leopard cat, respectively. In the left eye of the raccoon dog, 5 worms were recognized. Male worms were 969–11,860 μm long (10,600 μm on average) and 300–320 μm width (315 μm on average). Female worms were 13,430–15,330 (14,480) μm long and 320–370 (344) μm wide in size. They commonly had a characteristic scalariform buccal cavity and short esophagus. The vulva openings were located at the anterior of esophago-intestinal junction in females. The thelaziasis is reported in 2 species of wildlife, P. bengalensis and N. procyonoides, for the first time in Korea.

Thelazia callipaeda (Spirurida, Thelaziidae), a parasitic eye worm causing thelaziasis has been reported in humans and dogs in Korea. However, its occurrence in other potential reservoir hosts, including wild animals, remains unclear. In the present study, we described the 2 cases of thelaziasis from both of feral and captive wild animal in Korea. In August and November 2017, 2 cases of the parasitic infections were found in the third eyelid of rescued leopard cat Prionailurus bengalensis and reared raccoon dog Nyctereutes procyonoides at the Chungnam Wild Animal Rescue Center. A total of 20 and 24 worms were detected from the left and right eyes of leopard cat, respectively. In the left eye of the raccoon dog, 5 worms were recognized. Male worms were 969–11,860 μm long (10,600 μm on average) and 300–320 μm width (315 μm on average). Female worms were 13,430–15,330 (14,480) μm long and 320–370 (344) μm wide in size. They commonly had a characteristic scalariform buccal cavity and short esophagus. The vulva openings were located at the anterior of esophago-intestinal junction in females. The thelaziasis is reported in 2 species of wildlife, P. bengalensis and N. procyonoides, for the first time in Korea.