Defining the molecular dynamics associated with T cell differentiation enhances our understanding of T cell biology and opens up new possibilities for clinical implications. In this study, we investigated the dynamics of CD5 expression in CD8+ T cell differentiation and explored its potential clinical uses. Using PBMCs from 29 healthy donors, we observed a stepwise decrease in CD5 expression as CD8+ T cells progressed through the differentiation stages. Interestingly, we found that CD5 expression was initially upregulated in response to T cell receptor stimulation, but diminished as the cells underwent proliferation, potentially explaining the differentiation-associated CD5 downregulation. Based on the proliferationdependent downregulation of CD5, we hypothesized that relative CD5 expression could serve as a marker to distinguish the heterogeneous CD8+ T cell population based on their proliferation history. In support of this, we demonstrated that effector memory CD8+ T cells with higher CD5 expression exhibited phenotypic and functional characteristics resembling less differentiated cells compared to those with lower CD5 expression. Furthermore, in the retrospective analysis of PBMCs from 30 non-small cell lung cancer patients, we found that patients with higher CD5 expression in effector memory T cells displayed CD8+ T cells with a phenotype closer to the less differentiated cells, leading to favorable clinical outcomes in response to immune checkpoint inhibitor (ICI) therapy. These findings highlight the dynamics of CD5 expression as an indicator of CD8+ T cell differentiation status, and have implications for the development of predictive biomarker for ICI therapy.

Laparoscopic pancreatoduodenectomy (LPD) in pancreatic cancer is primarily criticized for its technical and oncological safety. Although solid evidence has not yet been established, many institutions are performing LPD for pancreatic cancer patients, with continuous efforts to ensure oncologic safety. In this video, we demonstrated a case of standard LPD combined with vascular resection in pancreatic cancer.

Laparoscopic pancreatoduodenectomy (LPD) in pancreatic cancer is primarily criticized for its technical and oncological safety. Although solid evidence has not yet been established, many institutions are performing LPD for pancreatic cancer patients, with continuous efforts to ensure oncologic safety. In this video, we demonstrated a case of standard LPD combined with vascular resection in pancreatic cancer.

Purpose: To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). Materials and Methods: Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution. Results: Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group. Conclusion Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

BACKGROUND: Third-generation tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKIs) have proved efficacious in treating non-small cell lung cancer (NSCLC) patients with acquired resistance resulting from the T790M mutation. However, since almost 50% patients with the acquired resistance do not harbor the T790M mutation, retreatment with first- or second-generation EGFR-TKIs may be a more viable therapeutic option. Here, we identified positive response predictors to retreatment, in patients who switched to a different EGFR-TKI, following initial treatment failure. METHODS: This study retrospectively reviewed the medical records of 42 NSCLC patients with EGFR mutations, whose cancers had progressed following initial treatment with gefitinib or erlotinib, and who had switched to a different first-generation EGFR-TKI during subsequent retreatment. To identify high response rate predictors in the changed EGFR-TKI retreatment, we analyzed the relationship between clinical and demographic parameters, and positive clinical outcomes, following retreatment with EGFR-TKI. RESULTS: Overall, 30 (71.4%) patients received gefitinib and 12 (28.6%) patients received erlotinib as their first EGFR-TKI treatment. Following retreatment with a different EGFR-TKI, the overall response and disease control rates were 21.4% and 64.3%, respectively. There was no significant association between their overall responses. The median progression-free survival (PFS) after retreatment was 2.0 months. However, PFS was significantly longer in patients whose time to progression was ≥10 months following initial EGFR-TKI treatment, who had a mutation of exon 19, or whose treatment interval was <90 days. CONCLUSION: In patients with acquired resistance to initial EGFR-TKI therapy, switched EGFR-TKI retreatment may be a salvage therapy for individuals possessing positive retreatment response predictors.
Carcinoma, Non-Small-Cell Lung* ; Disease-Free Survival ; Erlotinib Hydrochloride ; Exons ; Humans ; Medical Records ; Protein-Tyrosine Kinases ; Receptor, Epidermal Growth Factor ; Retreatment* ; Retrospective Studies ; Salvage Therapy ; Treatment Failure

BACKGROUND AND OBJECTIVES: The number of permanent pacemakers (PPMs) implanted in patients in Japan and Korea differs significantly. We aimed to investigate the differences in decision making processes of implanting a PPM. MATERIALS AND METHODS: Our survey included 15 clinical case scenarios based on the 2008 AHA/ACC/HRS guidelines for device-based therapy of cardiac rhythm abnormalities (class unspecified). Members of the Korean and Japanese Societies of Cardiology were asked to rate each scenario according to a 5-point scale and to indicate their decisions for or against implantation. RESULTS: Eighty-nine Korean physicians and 192 Japanese physicians replied to the questionnaire. For the case scenarios in which there was a class I indication for PPM implantation, the decision to implant a PPM did not differ significantly between the two physician groups. However, the Japanese physicians were significantly more likely than the Korean physicians to choose implantation in class IIa scenarios (48% vs. 37%, p<0.001), class IIb scenarios (40% vs. 19%, p<0.001), and class III scenarios (36% vs. 18%, p<0.001). These results did not change when the cases were categorized based on disease entity, such as sinus node dysfunction and conduction abnormality. CONCLUSION: Korean physicians are less likely than Japanese physicians to favor a PPM implantation when considering a variety of clinical case scenarios, which probably contributes to the relatively small number of PPMs implanted in patients in Korea as compared with those in Japan.
Asian Continental Ancestry Group ; Atrioventricular Block ; Cardiology ; Decision Making* ; Humans ; Japan* ; Korea* ; Pacemaker, Artificial ; Sick Sinus Syndrome

BACKGROUND AND OBJECTIVES: Identifying the critical isthmus of slow conduction is crucial for successful treatment of scar-related ventricular tachycardia. Current 3D mapping is not designed for tracking the critical isthmus and may lead to a risk of extensive ablation. We edited the algorithm to track the delayed potential in order to visualize the isthmus and compared the edited map with a conventional map. SUBJECTS AND METHODS: We marked every point that showed delayed potential with blue color. After substrate mapping, we edited to reset the annotation from true ventricular potential to delayed potential and then changed the window of interest from the conventional zone (early, 50-60%; late, 40-50% from peak of QRS) to the edited zone (early, 80-90%; late, 10-20%) for every blue point. Finally, we compared the propagation maps before and after editing. RESULTS: We analyzed five scar-related ventricular tachycardia cases. In the propagation maps, the resetting map showed the critical isthmus and entrance and exit sites of tachycardia that showed figure 8 reentry. However, conventional maps only showed the earliest ventricular activation sites and searched for focal tachycardia. All of the tachycardia cases were terminated by ablating the area around the isthmus. CONCLUSION: Identifying the channel and direction of the critical isthmus by a new editing method to track delayed potential is essential in scar-related tachycardia.
Tachycardia ; Tachycardia, Ventricular*

Intracranial hemangiopericytoma (HPC) is a rare brain tumor with aggressive biologic behavior associated with high recurrence rate and often with extracranial metastasis. The most common sites of extracranial metastasis of the intracranial HPC are the long bones, lung, liver and abdominal cavity in the order of frequencies. Extracranial metastases usually occur long after the initial diagnosis of the primary tumor. Metastatic intracranial HPC to the vertebra has been rarely reported. We present a case of intracranial HPC metastasized to the L2 vertebral body 13 years after multiple surgical resections and radiotherapy of the primary intracranial HPC.
Abdominal Cavity ; Brain Neoplasms ; Diagnosis ; Hemangiopericytoma* ; Liver ; Lumbar Vertebrae ; Lung ; Neoplasm Metastasis ; Radiotherapy ; Recurrence ; Spine*

PURPOSE: Meckel's diverticulum (MD) has various clinical manifestations, and diagnosis or selectection of proper diagnostic tools is not easy. This study was conducted in order to assess the clinical differences of MD diagnosed by scintigraphic and non-scintigraphic methods and to find the proper diagnostic tools. METHODS: We conducted a retrospective review ofthe clinical, surgical, radiologic, and pathologic findings of 34 children with symptomatic MD, who were admitted to Gachon University Gil Medical Center, Inha University Hospital, and The Catholic University of Korea, Incheon St. Mary's Hospital between January 2000 and December 2012. The patients were evaluated according to scintigraphic (12 cases; group 1) and non-scintigraphic (22 cases; group 2) diagnosis. RESULTS: The male to female ratio was 7.5 : 1. The most frequent chief complaint was lower gastrointestinal (GI) bleeding in group 1 and nonspecific abdominal pain in group 2, respectively. The most frequent pre-operative diagnosis was MD in both groups. Red blood cell (RBC) index was significantly lower in group 1. MD was located at 7 cm to 85 cm from the ileocecal valve. Four patients in group 1 had ectopic gastric tissues causing lower GI bleeding. The most frequent treatment modality was diverticulectomy in group 1 and ileal resection in group 2, respectively. CONCLUSION: To diagnose MD might be delayed unless proper diagnostic tools are considered. It is important to understand indications of scintigraphic and non-scintigraphic methods according to clinical and hematologic features of MD. Scintigraphy would be weighed in patients with anemia as well as GI symptoms.
Abdominal Pain ; Anemia ; Child ; Erythrocytes ; Female ; Hemorrhage ; Humans ; Ileocecal Valve ; Korea ; Male ; Meckel Diverticulum ; Retrospective Studies

BACKGROUND: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. METHODS: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. RESULTS: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. CONCLUSION: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.
1-Methyl-3-isobutylxanthine ; Adenocarcinoma ; Blotting, Western ; Cell Line ; Cell Transformation, Neoplastic ; Chromogranin A ; Cisplatin ; Drug Resistance, Neoplasm ; Epidermal Growth Factor ; Etoposide ; Humans ; Lung ; Lung Neoplasms ; Parents ; Piperidines ; Poly(ADP-ribose) Polymerases ; Protein-Tyrosine Kinases ; Quinazolines ; Receptor, Epidermal Growth Factor ; Small Cell Lung Carcinoma ; Synaptophysin ; Erlotinib Hydrochloride