Publications by authors named "Changhyeok An"

Neoadjuvant chemotherapy combined with bevacizumab is used to treat colorectal cancer (CRC) patients by targeting tumor and vascular cells. However, it is known that other cells in the tumor microenvironment (TME) also change in response to this treatment. To investigate the changes in TME subpopulations in response to neoadjuvant FOLFOX6 plus bevacizumab, we studied pre- and post-treatment CRC tissues in four patients using single-cell RNA sequencing (scRNA-seq).

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Methylation patterns in cell-free DNA (cfDNA) have emerged as a promising genomic feature for detecting the presence of cancer and determining its origin. The purpose of this study was to evaluate the diagnostic performance of methylation-sensitive restriction enzyme digestion followed by sequencing (MRE-Seq) using cfDNA, and to investigate the cancer signal origin (CSO) of the cancer using a deep neural network (DNN) analyses for liquid biopsy of colorectal and lung cancer. We developed a selective MRE-Seq method with DNN learning-based prediction model using demethylated-sequence-depth patterns from 63,266 CpG sites using SacII enzyme digestion.

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Purpose: Single incision laparoscopic cholecystectomy (SILC) has some technical problems. Our group has performed needlescopic grasper assisted SILC (nSILC) to overcome these problems. In this study, we introduce our technique and evaluate the safety and feasibility of this technique compared with the conventional laparoscopic cholecystectomy (CLC).

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Aim: To investigate the safety and feasibility of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration (nSIL-CBDE) by comparing the surgical outcomes of this technique with those of conventional laparoscopic CBDE (CL-CBDE).

Methods: We retrospectively analyzed the clinical data of patients who underwent CL-CBDE or nSIL-CBDE for the treatment of common bile duct (CBD) stones between January 2000 and December 2014. For performing nSIL-CBDE, a needlescopic grasper was also inserted through a direct puncture below the right subcostal line after introducing a single-port through the umbilicus.

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Introduction: Single-incision laparoscopic cholecystectomy (SILC) has been increasing in use steadily, and many researchers have reported the safety and feasibility of SILC. However, most studies were confined to selected patients and excluded patients with acute inflammation. In this study, we evaluated the safety and feasibility of SILC with our technique in patients with acute cholecystitis.

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Background/aims: TO EVALUATE THE PROGNOSTIC IMPACT OF THE LYMPH NODE RATIO (LNR: the ratio of positive lymph nodes to the total number of lymph nodes examined) on disease recurrence and survival among rectal cancer patients who received curative surgery and postoperative chemoradiotherapy (CRT).

Methods: Between 1995 and 2008, 124 patients with pathologic T3-4 or node-positive rectal cancer underwent curative surgery and postoperative CRT. Postoperative radiotherapy was delivered at a median dose of 50.

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Fas-mediated apoptosis is a crucial cellular event. Fas, the Fas-associated death domain, and caspase 8 form the death-inducing signaling complex (DISC). Activated caspase 8 mediates the extrinsic pathways and cleaves cytosolic BID.

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A 48-year-old woman who was without any abnormal past medical history underwent colonoscopy as a screening procedure for colorectal disease. The procedure was uneventful and there was no sign of inflammation around the appendicular orifice or the luminal surface of the cecum. The patient did not complain of pain or significant discomfort throughout the procedure.

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Purpose: The influence of molecular characteristics in prognosis of gastric cancer remains unclear. The aim of this study was to evaluate the prognostic value of the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) in gastric cancer.

Experimental Design: We studied the methylation profiles of tumor suppressor gene p16, DNA mismatch repair gene hMLH1, and four CpG islands (MINT1, MINT2, MINT25, and MINT31) using bisulfite/methylation-specific PCR, and MSI using five microsatellite markers in 83 resected gastric carcinomas.

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Synopsis of recent research by authors named "Changhyeok An"

  • - Changhyeok An's recent research primarily focuses on colorectal cancer (CRC), exploring innovative diagnostic techniques and treatment responses, particularly in the context of neoadjuvant therapies like FOLFOX6 combined with bevacizumab, using advanced methodologies such as single-cell RNA sequencing.
  • - An's study on methylation patterns in cell-free DNA (cfDNA) illustrates the potential of liquid biopsy for early cancer detection in CRC and lung cancer, specifically enhancing diagnostic capabilities through methylation-sensitive techniques and deep neural network analyses.
  • - Additionally, An has contributed to the field of laparoscopic surgery by investigating the safety and feasibility of needlescopic grasper-assisted techniques for gallbladder and bile duct surgeries, aiming to improve surgical outcomes and reduce complications compared to conventional methods.