When the physician–government conflict was triggered by the Korean government’s plan to increase medical school enrollment by 2,000 students, the government proposed the establishment of a "Jokbo Sharing Center." In Korean medical education, jokbo refers to collections of previous examination questions, summarized notes, and anticipated topics compiled by senior students and transmitted across cohorts. Their scope extends beyond preclinical education and written examinations to include practical tips and informal norms passed down during clinical clerkships and internship rotations. More than a mere compilation of study resources, jokbo functions as a form of hidden curriculum within medical education. As a learning culture that has emerged organically among students, it operates implicitly beneath the formal curriculum. The creation and sharing of jokbo can foster solidarity and a sense of belonging, and may serve as a process through which students begin to internalize the professional culture essential to their future roles as physicians. Nevertheless, reliance on jokbo- based learning may undermine the depth and quality of learning over time, impeding critical thinking, problem-solving skills, and the acquisition of integrated medical knowledge. Unregulated distribution of such materials also raises concerns about examination fairness, and their reproduction without faculty consent raises legitimate ethical concerns. At the same time, given their demonstrable educational benefits, some argue for institutionalizing jokbo through transparent procedures for constructive use in medical education. Despite its widespread presence, research on jokbo remains virtually nonexistent. This study aims to establish a scholarly and policy foundation for discussion of jokbo in Korean medical education by reviewing international cases of examination material sharing and providing a comprehensive analysis of jokbo in Korea.

Probiotics have gained increasing clinical attention as adjunctive treatment for lower gastrointestinal disorders. However, evidence supporting their therapeutic efficacy remains limited, particularly with regard to sex-related differences. This expert review provides evidence-based insights and practical recommendations for the use of probiotics in patients with irritable bowel syndrome (IBS), functional constipation (FC), and Clostridioides difficile infection (CDI), considering possible sex-related differences. Evidence from randomized controlled trials and meta-analyses indicates that probiotics can modestly improve global symptoms, abdominal pain, and bloating in IBS and enhance bowel movement frequency and stool consistency in FC. However, these effects are strain-specific and heterogeneous. Although clinical studies on probiotics in IBS have not confirmed significant sex-related differences, experimental animal studies using stress-induced IBS models have demonstrated sex-dependent responses to specific probiotic strains, supporting the biological plausibility of such differences. For CDI, the efficacy of probiotics in preventing primary or recurrent infections remains inconsistent across large trials, and current guidelines usually do not recommend their routine use. However, sex- and age-related immunologic differences support the clinical differences of CDI. Probiotics are generally considered safe for healthy individuals, although caution is advised in patients who are immunocompromised or critically ill. Clinicians should select probiotic products based on strain-specific clinical evidence, adequate viable doses, patient characteristics and sex. In conclusion, probiotics might play a role as adjunctive therapy for IBS and FC, with variability in responses influenced by microbial, host, and potential sex-related factors. Further research is needed to establish optimized personalized probiotic strategies.

Methylenetetrahydrofolate reductase (MTHFR) gene mutations, particularly homozygous mutations, have been associated with a higher incidence of venous thrombosis, coronary heart disease, and obstetric complications. We report the case of a 41-year-old man who presented with multiple vascular thrombotic events over a period of 4–5 years, including deep vein thrombosis with pulmonary thromboembolism, cerebral venous thrombosis and posterior circulation stroke. The patient was found to have elevated serum homocysteine levels and subsequently underwent genetic testing for MTHFR mutations after other potential prothrombotic conditions were excluded. This case is notable because compound heterozygous mutations of the MTHFR gene (C677T and A1298C) were identified in association with recurrent vascular thrombotic events. Management focused on long-term anticoagulation and supplementation with vitamin B6, vitamin B12, and folic acid.

We present a rare case of a 68-year-old woman who experienced dizziness, nausea, vomiting, and imbalance for 2 months. Imaging studies, including magnetic resonance imaging, magnetic resonance angiography, and digital subtraction angiography, revealed an intrasellar course of the persistent trigeminal artery (PTA) with atherosclerotic changes. Additionally, hypoplasia of the basilar artery and left vertebral artery was observed. The anatomically rare intrasellar PTA, combined with atherosclerosis and vertebrobasilar hypoplasia, likely contributed to compromised posterior circulation and the patient’s symptoms. This case highlights the importance of considering vascular anomalies and the associated pathological changes in patients with otherwise unexplained posterior circulation symptoms.

Elastofibroma dorsi is a rare, benign soft tissue tumor that typically arises in the infrascapular region. Although it is often asymptomatic, some patients experience pain or a snapping sensation during shoulder movement, which warrants surgical excision. We report a symptomatic case in a middle-aged male patient, highlighting the diagnostic imaging features and surgical management of this condition.

Itching is a representative manifestation of urticaria. However, under certain conditions, urticaria may be characterized by nociceptive sensations, such as stinging or tingling, either instead of or in addition to itching. Three patients with chronic urticaria (CU) who experienced nociceptive pain accompanied by itching were identified and treated with immunoglobulin/histamine complex (IHC) therapy. Nociceptive pain resolved along with improvement in CU symptoms after 8 injections of IHC in the first patient and after 4 injections in the second and third patients. Nociceptive pain may present as a symptom of CU. The clinical characteristics of the transition from itching to nociceptive pain, together with the observed outcomes of IHC therapy, appear to support the intensity theory explaining this shift, which may be mediated by histamine. Further clinical and basic immunological studies are warranted to clarify the underlying mechanisms.