Monoclonal protein (M-protein) is a crucial biomarker for diagnosing and monitoring monoclonal gammopathies, including multiple myeloma (MM). Traditionally, electrophoresis (EP)-based methods, such as protein EP and immunofixation EP, have been widely used for M-protein detection. However, these methods can show low sensitivity and inadequate quantification of small amounts of M-protein. To overcome these challenges, EP-based methods are often combined with the quantification of serum free light chains in automated immunoassays. Advances in mass spectrometry (MS) have introduced three main approaches for sample preparation: top-down, middle-down, and bottom-up. Middle-down approaches are commonly used with matrix-assisted laser desorption/ionization time-offlight MS and liquid chromatography–electrospray ionization (LC–ESI) quadrupole time-offlight MS, whereas the bottom-up approach is typically applied with LC–ESI Orbitrap MS. A review of studies, conducted from 2014 to 2024, on plasma cell disorders that utilized MS-based methods demonstrate improvements in the sensitivity and accuracy of M-protein identification and quantification. MM remains the most frequently studied disease, with significant therapeutic advancements leading to improved outcomes. Minimal residual disease has gained attention because of its correlation with better prognoses. Monoclonal gammopathy of undetermined significance and amyloid light-chain amyloidosis are occasionally addressed, while studies on other rare diseases remain limited. This review highlights the clinical applications and advancements in MS-based methods, particularly in assessing M-protein levels for treatment responses, risk factors, and prognostic monitoring. Given their advantages—high sensitivity and specificity, automation, cost-effectiveness, and time efficiency—MS-based methods may eventually replace EP-based methods in clinical laboratories.

Background: Rapid pathogen identification and antibiotic-susceptibility tests (ASTs) are important for treating bloodstream infections. We compared the performance of the QMAC-dRAST and BD Phoenix M50 direct AST (dPhoenix) systems using bacterial pellets prepared from positive blood culture broth and evaluated their impact on treatment modification. Methods: Direct AST results for 106 Enterobacterales isolates were retrospectively reviewed. Conventional broth microdilution was used to calculate categorical agreement (CA), very major error (VME), major error (ME), and minor error (mE). For isolates showing high VMEs in both methods, supplementary tests were performed. Clinical impact was evaluated by calculating the time required to obtain AST results (time-to-result) and observing changes in antibiotics prescribed after performing ASTs. Results: Both systems showed acceptable overall CA, VME, ME, and mE values (QMACdRAST: 93.6%, 1.6%, 0.9%, and 5.3%, respectively; dPhoenix: 93.1%, 0.9%, 0.6%, and 6.2%, respectively). Piperacillin–tazobactam showed high VMEs with QMAC-dRAST (4/20, 20.0%) and dPhoenix (3/20, 15.0%). Colony AST on 13 isolates revealed that QMACdRAST testing yielded lower minimal inhibitory concentrations (MICs) for piperacillin–tazobactam with three isolates, whereas dPhoenix testing yielded higher MICs with two isolates and lower MICs with two isolates. The average time-to-result was 20.8 hr and 30.1 hr for QMAC-dRAST and dPhoenix, respectively (P < 0.001). After AST, the number of optimal treatments increased from 43 (46.7%) to 72 (78.3%) (P < 0.001). Conclusions The QMAC-dRAST and dPhoenix systems provided reliable AST results with a short time-to-result. However, we recommend performing complementary tests, such as the disk diffusion test, for piperacillin–tazobactam.

Legal risks and liability issues in medical practice serve as a primary catalyst for the current collapse of essential healthcare services in Korea. Currently, medical disputes in Korea are disproportionately focused on criminal prosecutions and high-damages civil litigation. This punitive approach fosters a culture of concealment, encourages defensive medicine, and accelerates the exodus of medical professionals from essential fields. Ultimately, this cycle deprives the system of opportunities for improvement and poses a significant threat to patient safety. In contrast, many advanced nations have adopted principles of “Just Culture” and “Safe Space,” prioritizing non-punitive reporting and systemic root-cause analysis over individual retribution. To address these issues, this paper proposes four key strategies: First, the establishment of an independent “Patient Safety Investigation Agency” to objectively investigate incidents and identify systemic flaws. Second, a transition from criminal punishment to licensing board-led management, focusing on re-education and counseling to maintain quality of care. Third, the enactment of “Apology Laws” to ensure that expressions of regret or apologies cannot be used as legal evidence of liability, thereby fostering trust and psychological recovery. Finally, the creation of a “Patient Safety Fund” to provide prompt and sufficient public compensation to victims regardless of proven negligence. In conclusion, it is imperative to shift the paradigm by defining medical accidents as “system failures” rather than individual faults. Strengthening the social safety net will encourage medical professionals to return to essential care and build a sustainable healthcare environment centered on patient safety.

Korea’s healthcare system is at a critical juncture as rapid population aging, rising chronic disease burdens, and fragmented care expose the limits of a hospital-centered, fee-for-service model. Although policy discussions have long emphasized strengthening primary care and introducing a “family doctor” system, past reforms have focused mainly on expanding services or redefining professional roles, without establishing clear accountability, care continuity, or aligned payment mechanisms. Consequently, primary care remains weak and responsibility for comprehensive patient management is diffuse. This article argues that meaningful reform requires redefining the primary physician as an accountable manager of longitudinal, coordinated care within an integrated delivery and payment framework. Drawing on experiences from the United States, the United Kingdom, and several European countries, it identifies common features of successful primary care–oriented systems, including patient registration, team-based care, risk-adjusted payment, and explicit outcome accountability. Based on these insights, the authors propose a Korean primary physician model tailored to solo and small-group practices while fostering regional collaboration. Core elements include voluntary patient registration, multidisciplinary primary care teams, risk-stratified care management, regional care networks, and a mixed payment model combining per-member-per-month payments, shared savings, and performance-based incentives. The article emphasizes phased pilot testing focused on operational feasibility. Ultimately, transitioning to a primary care–centered system is presented as a strategic necessity for sustainability and improved care continuity.

Anomalous union of the pancreaticobiliary duct (AUPBD) is a congenital malformation in which the pancreatic and biliary ducts join outside the duodenal wall, forming an elongated common channel. Because sphincter action does not directly affect this junction, reciprocal reflux of pancreatic juice and bile occurs, increasing the risk of biliary tract cancer. AUPBD is frequently associated with choledochal cysts and is a known risk factor for biliary malignancies. We report a case of a 70-year-old woman diagnosed with gallbladder cancer with liver metastases, accompanied by AUPBD without choledochal cysts. She presented with upper abdominal pain, obstructive jaundice, and a large hepatic mass on imaging. Endoscopic retrograde cholangiopancreatography confirmed pancreatobiliary-type AUPBD. Despite biliary drainage, her condition rapidly deteriorated and she died soon after. This case underscores the role of AUPBD in carcinogenesis and the need for early recognition and management.

Alzheimer’s disease (AD) is characterized by progressive cognitive deterioration and significant depression. However, the mechanisms linking depression to AD pathology remain unclear. Here, we investigated whether Notch2 signaling mediates depressionlike behaviors in presenilin-2 (PS2) N141I mutant mice, an early-onset AD model. PS2 wild-type (WT) and mutant (MT) mice aged 12-15 months were subjected to unpredictable chronic mild stress (UCMS) for 4 weeks, followed by sucrose preference, tail-hanging, and forced swimming tests. Behavioral assessments showed that UCMS exacerbated anhedonia and immobility only in PS2 MT mice. Molecular analysis revealed concomitant increases in plasma corticosterone, hippocampal γ-secretase activity, and Notch2 expression, and elevated total and phosphorylated glucocorticoid receptor levels in PS2 MT-UCMS mice. Gene expression profiling of human hippocampal datasets confirmed upregulation of NOTCH2 in Alzheimer’s disease and depression.Pharmacological inhibition of γ-secretase and Notch signaling with DAPT normalizes depressive behavior, reduces corticosterone release, attenuates GR phosphorylation, and inhibits Notch2 signaling in PS2 MT mice. These findings identify Notch2 as a pivotal mediator linking chronic stress to molecular changes associated with depression and AD, and suggest that targeting Notch2 signaling may provide therapeutic benefits for comorbid mood and neurodegenerative disorders.

Background: Parenchymal brain metastasis (BM) and its extended growth into cerebrospinal fluid(CSF) pathways or surgical spillage could result in leptomeningeal metastasis (LM). We defined BM with epipial spread or dural attachment on MRI as BM with CSF space invasion (BM-CSFi), regardless of CSF cytology results, and evaluated its clinical course after BM resection. Methods: We retrospectively reviewed 297 patients who underwent craniotomy for BM exclud-ing patients followed for <6 months or without follow-up MRI. Primary outcomes were proportion of patients progressing to overt LM and time to progression. We also evaluated clinical and radiologic variables to identify risk factors for LM progression. Results: A total of 91 patients (30.6%) developed overt LM, with median time to progressionof 7.9 months during 18.3 months follow-up after the craniotomy. On multivariable analysis, preoperative MRI evidence of dural attachment with enhancement (hazard ratio [HR], 5.59; p=0.002), primary small cell lung cancer (HR, 4.92; p=0.026), infratentorial BM location (HR, 2.14; p=0.019), and postoperative cumulative CSF cytology positive rate ≥50% (HR, 7.13; p=0.012) were independent risk factors for LM progression. The mode of resection and postoperative radiotherapy or systemic chemotherapy were not significantly associated with LM progression. Conclusion BM-CSFi, defined by preoperative MRI findings, may represent a clinically importantprecursor of LM. Our findings highlight the need for close monitoring of patients with BM-CSFi and the development of management protocols to minimize the risk of LM progression.

Chronic rhinosinusitis (CRS) is increasingly recognized as a heterogeneous disease with distinct inflammatory endotypes, among which eosinophilic CRS (ECRS)—a category that substantially overlaps with, but is not equivalent to, Type 2 CRS—is associated with severe symptoms, frequent recurrence, and comorbid asthma. Accurate identification of Type 2 CRS has become clinically essential with the emergence of biologic therapies that target Type 2 inflammatory pathways. However, most diagnostic criteria, including those proposed by European Position Paper on Rhinosinusitis and Nasal Polyps 2020 (EPOS 2020), were developed from Western populations, in which ECRS with nasal polyps predominates. This review critically examines the applicability of these criteria in Asian populations, in which non-eosinophilic and mixed inflammatory endotypes remain prevalent. Evidence from Korean and Japanese cohorts indicates that the EPOS 2020 Type 2 criteria have poor specificity in Asian patients with CRS with nasal polyps, classifying nearly all such patients as Type 2 because of differences in baseline biomarker distributions. We discuss histological thresholds for defining ECRS and highlight that Asian studies support higher tissue eosinophil cut-offs, approximately 70 eosinophils per high-power field (HPF) or around 10% of total inflammatory cells, compared with the 10 eosinophils per HPF recommended by Western guidelines. This review also evaluates outpatient- friendly scoring systems, such as Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) and newly proposed Korean diagnostic criteria, as well as emerging machine-learning approaches for noninvasive prediction of ECRS. We conclude that clinicians in Asia should adopt regionally validated criteria that integrate histological, serological, and clinical parameters to accurately identify Type 2 CRS, optimize selection of biologic candidates, and improve prognostic counseling in this population.

Shared decision-making (SDM) is a core element of patient-centered care; however, traditional approaches to informed consent and physicians’ duty to explain have often remained procedural and predominantly physician-driven. This review aims to examine how SDM substantively strengthens the physician’s duty to explain and how it may contribute to reducing medical litigation risk while simultaneously improving patient–physician relationships.Current concepts: SDM is a collaborative process in which patients and physicians jointly consider available treatment options, relevant medical evidence, and patients’ individual values and preferences. Evidence from systematic reviews indicates that SDM improves patients’ knowledge, promotes more realistic expectations, reduces decisional conflict, and enhances satisfaction and trust. From a legal perspective, inadequate communication and information asymmetry constitute major contributors to medical disputes. By emphasizing meaningful dialogue, documenting deliberative processes, and incorporating patient decision aids, SDM reframes informed consent from a largely formal requirement into an interactive process that supports patients’ substantive understanding and autonomous decision-making.Discussion and conclusion: Although direct evidence demonstrating that SDM reduces medical errors remains limited, existing findings suggest that SDM may mitigate structural causes of medical disputes by addressing communication failures and unmet patient expectations. By reinforcing the physician’s duty to explain in a substantive and patient-centered manner and by fostering a trust-based therapeutic alliance, SDM has the potential to reduce medical litigation risk. Integrating SDM into routine clinical practice through education, institutional support, and supportive legal frameworks may represent an emerging standard for fulfilling physicians’ duty to explain and for promoting sustainable patient–physician relationships.