Su Bee Park

Background and Objectives: Liver regeneration following partial hepatectomy (PHx) is essential for restoring hepatic function. Polydeoxyribonucleotide (PDRN), an adenosine A_2A receptor (A_2AR) agonist, has demonstrated regenerative and proangiogenic properties in various tissues. However, its therapeutic potential for promoting liver regeneration after PHx has not been fully elucidated. The primary objective was to evaluate the effect of PDRN on liver regeneration after PHx, and the secondary objective was to examine associated changes in proliferation-related proteins and A_2AR/cAMP, HGF/c-Met, and VEGF/VEGFR2 signaling. Materials and Methods: A rat model of 70% PHx was established, and PDRN (8 mg/kg) was administered intraperitoneally once daily for 5 consecutive days with or without the A_2AR antagonist 3,7-dimethyl-1-propargylxanthine (DMPX; 8 mg/kg). Liver regeneration was evaluated using biochemical, histological, and molecular analyses. Results: PDRN enhanced liver regeneration following PHx, as demonstrated by reduced serum liver enzyme levels, enhanced recovery of liver mass, and improved histological architecture. PDRN also increased the expression of the proliferation-associated proteins proliferating cell nuclear antigen (PCNA) and cyclin D1. These effects were accompanied by increased A_2AR expression and cyclic adenosine monophosphate (cAMP) levels, elevated hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) levels, and enhanced phosphorylation of c-Met and VEGFR2. Co-administration of DMPX attenuated the regenerative and molecular effects of PDRN, suggesting a potential involvement of A_2AR-related signaling. Conclusions: Collectively, these findings suggest that PDRN may facilitate liver regeneration following PHx in association with increased expression of proliferation-associated proteins and changes in HGF/c-Met and VEGF/VEGFR2 signaling, supporting its potential as a therapeutic strategy following hepatic resection.

Background/Objectives: Polydeoxyribonucleotide (PDRN) has anti-inflammatory and tissue-protective properties associated with activation of the adenosine A_2A receptor (A_2AR). Although hepatoprotective actions of PDRN have previously been described, its potential association with high-mobility group box 1 (HMGB1)-related inflammatory responses and hepatic macrophage accumulation during acute liver injury (ALI) is not fully understood. This study examined whether PDRN affects HMGB1- and monocyte chemoattractant protein-1 (MCP-1)-associated responses together with hepatic macrophage accumulation in ALI. Methods: ALI was induced in ICR mice by carbon tetrachloride (CCl₄) administration. PDRN was administered either alone or together with the selective A_2AR antagonist 3,7-dimethyl-1-propargylxanthine (DMPX). Serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase were quantified. Histological alterations were evaluated using hematoxylin and eosin staining. Hepatic macrophage accumulation was assessed by F4/80 immunofluorescence staining. Enzyme-linked immunosorbent assays were used to quantify HMGB1, MCP-1, interleukin-10 (IL-10), cyclic adenosine monophosphate (cAMP), and A_2AR. Results: PDRN significantly reduced serum markers of liver injury and attenuated histopathological damage following CCl₄ administration. PDRN treatment also decreased F4/80-positive macrophage accumulation in the hepatic tissue. In addition, PDRN reduced HMGB1 and MCP-1 levels in both the serum and liver tissues while significantly increasing IL-10, cAMP, and A_2AR levels. Conclusions: PDRN attenuated CCl₄-induced ALI and was associated with reduced HMGB1 and MCP-1 levels, decreased hepatic macrophage accumulation, and increased A_2AR/cAMP signaling. These findings suggest that modulation of macrophage-associated inflammatory responses may contribute to the hepatoprotective effects of PDRN.

Rationale: Retroperitoneal fibrosis (RPF) is a rare fibroinflammatory condition that can lead to ureteral obstruction and renal dysfunction. While most cases are idiopathic, secondary causes including malignancies should be considered. RPF secondary to gastric cancer is extremely rare, with only a few cases reported. Patient concerns: A 56-year-old woman presented with generalized edema, decreased urine output, and nausea that had begun 7 days prior. Laboratory tests revealed acute kidney injury, and imaging showed bilateral hydronephrosis. Diagnoses: Further evaluation through abdominal-pelvic computed tomography and esophagogastroduodenoscopy revealed a depressed ulcerative gastric lesion. Histopathological examination confirmed poorly differentiated gastric adenocarcinoma. Intraoperative biopsy of retroperitoneal fibrotic tissue showed malignant cell infiltration, confirming RPF secondary to gastric cancer. Interventions: The patient underwent subtotal gastrectomy and bilateral percutaneous nephrostomy for urinary diversion. Antibiotics were administered postoperatively for urinary tract infection. She was discharged with a plan for adjuvant chemotherapy. Outcomes: Urine output and renal function normalized following percutaneous nephrostomy insertion. The patient’s infection resolved with antibiotic therapy, and she remained clinically stable at discharge. Lessons: This case illustrates a rare presentation of gastric cancer manifesting as malignancy-associated RPF. Clinicians should maintain a high index of suspicion for occult malignancy in patients with bilateral ureteral obstruction of unclear cause. Early imaging and histological evaluation are critical for diagnosis and appropriate management.

The leading causes of refractory peptic ulcers are Helicobacter pylori infection and nonsteroidal anti-inflammatory drugs. Additionally, insufficient treatment for the suppression of gastric acid, smoking, alcohol consumption, and concomitant diseases can hinder recovery. Treatment includes the eradication of H. pylori, discontinuation of the causative agent, and appropriate suppression of gastric acid. Even after improvement of symptoms, sufficient proton pump inhibitor maintenance is necessary for 8 to 12 weeks. To increase the success rate of H. pylori eradication, it is essential to accurately determine the initial infection and for patients where treatment has failed due to antibiotic resistance, the success rate of treatment can be increased through sensitivity testing. Sometimes, evaluation for rare causes, such as Zollinger–Ellison syndrome, may be necessary, and follow-up gastroscopy must be performed to exclude the possibility of malignancy.

Ulcerative colitis (UC) is characterized by continuous mucosal ulceration of the colon, starting in the rectum. 5-Aminosalicylic acid (5-ASA) is the main therapy for ulcerative colitis; however, it has side effects. Physical exercise effectively increases the number of anti-inflammatory and anti-immune cells in the body. In the current study, the effects of simultaneous treatment of treadmill exercise and 5-ASA were compared with monotherapy with physical exercise or 5-ASA in UC mice. To induce the UC animal model, the mice consumed 2% dextran sulfate sodium dissolved in drinking water for 7 days. The mice in the exercise groups exercised on a treadmill for 1 h once a day for 14 days after UC induction. The 5-ASA-treated groups received 5-ASA by enema injection using a 200 μL polyethylene catheter once a day for 14 days. Simultaneous treatment improved histological damage and increased body weight, colon weight, and colon length, whereas the disease activity index score and collagen deposition were decreased. Simultaneous treatment with treadmill exercise and 5-ASA suppressed pro-inflammatory cytokines and apoptosis following UC. The benefits of this simultaneous treatment may be due to inhibition on nuclear factor-κB/mitogen-activated protein kinase signaling activation. Based on this study, simultaneous treatment of treadmill exercise and 5-ASA can be considered as a new therapy of UC.

Background/Aims: The impact of coronavirus disease 2019 (COVID-19) on the management of colorectal cancer (CRC) may worse in elderly population, as almost all COVID-19 deaths occurred in the elderly patients. This study aimed to evaluate the impact of COVID-19 on CRC management in the elderly population.Methods: The numbers of patients who underwent colonoscopy, who visited hospitals or operated for CRC in 2020 and 2021 (COVID-19 era) were compared with those in 2019, according to 3 age groups (≥70 years, 50–69 years, and ≤49 years), based on the nationwide, population-based database (2019–2021) in South Korea.Results: The annual volumes of colonoscopy and hospital visits for CRC in 2020 were more significantly declined in the old age group than in the young age group (both P<0.001). In addition, the annual volume of patients operated for CRC numerically more declined in old age group than in young age group. During the first surge of COVID-19 (March and April 2020), old age patients showed statistically significant declines for the monthly number of colonoscopies (–46.5% vs. –39.3%, P<0.001), hospital visits (–15.4% vs. –7.9%, P<0.001), CRC operations (–33.8% vs. –0.7%, P<0.05), and colonoscopic polypectomies (–41.8% vs. –38.0%, P<0.001) than young age patients, compared with those of same months in 2019.Conclusions: Elderly population are more vulnerable for the management of CRC during the COVID-19 pandemic. Therefore, the elderly population are more carefully cared for in the management of CRC during the next pandemic.

Background: Early-onset colorectal cancer (EOCRC) may differ by race and ethnicity, and recently South Korea has witnessed a surge in cases. We aimed to evaluate the clinical and pathological features of patients with EOCRC, and to determine the predictors of overall survival. Methods: In this retrospective study, EOCRC was defined as CRC diagnosed in patients aged < 50 years, and late-onset CRC was defined as CRC diagnosed in those over 75 years of age. The clinical and pathological characteristics of patients with EOCRC were compared with late-onset CRC. We also used multivariable Cox proportional hazard models to find predictors of overall survival in patients with EOCRC. Results: The proportion of early-onset CRC was 9.1% of 518 patients with CRC, and the clinical and pathological characteristics were similar between early-onset (n = 47) and late-onset CRC (n = 134). However, EOCRC had a preponderance for distal tumor location (70.2% vs. 50.7%, P = 0.02) and T1-2 stage disease (23.4% vs. 11.2%, P = 0.04), compared with those of late-onset CRC. Using multivariable Cox proportional hazard models, only vascular invasion (hazard ratio = 8.75, 95% confidence interval 1.139‒67.197) was found to be a risk factor for overall survival (P = 0.04) for patients with CRC. Conclusion: EOCRC had preponderance for distal tumor location and early T-stage disease, compared with late-onset CRC. Considering the increasing incidence of EOCRC, more studies on clinical and pathological characteristics of EOCRC may be warranted.

Climate change is a global emergency. Consequently, current global targets to combat the climate crisis include reaching net-zero carbon emissions by 2050 and keeping global temperature increases below 1.5 ˚C. In 2014, the healthcare carbon footprint was 5.5% of the total national footprint. Gastrointestinal endoscopy (GIE) has a large carbon footprint compared to other procedures performed in healthcare facilities. GIE was identified as the third largest generator of medical waste in healthcare facilities for the following reasons: (1) GIE is associated with high case volumes, (2) GIE patients and relatives travel frequently, (3) GIE involves the use of many nonrenewable wastes, (4) single-use devices are used during GIE, and (5) GIE is frequently reprocessed. Immediate actions to reduce the environmental impact of GIE include: (1) adhering to guidelines, (2) implementing audit strategies to determine the appropriateness of GIE, (3) avoiding unnecessary procedures, (4) using medication rationally, (4) digitalization, (5) telemedicine, (6) critical pathways, (7) outpatient procedures, (8) adequate waste management, and (9) minimizing single-use devices. In addition, sustainable infrastructure for endoscopy units, using renewable energy, and 3R (reduce, reuse, and recycle) programs are necessary to reduce the impact of GIE on the climate crisis. Consequently, healthcare providers need to work together to achieve a more sustainable future. Therefore, strategies must be implemented to achieve net-zero carbon emissions in the healthcare field, especially from GIE, by 2050.

Background and Objectives: The risk of bleeding after endoscopic procedures in patients with liver cirrhosis remains unclear because of secondary blood coagulation disorders. In this study, we used various indices to evaluate the risk of bleeding in patients with cirrhosis. Materials and Methods: Patients with liver cirrhosis aged ≥18 years who underwent endoscopic interventions at Kyung Hee University Hospital at Gangdong between February 2007 and September 2021 were included. Clinical information, including demographic data, laboratory results, the presence of cirrhosis complications, and the degree of fibrosis, was checked and evaluated based on medical records. Results: A total of 101 patients with cirrhosis were analyzed. A total of 16 of the 101 patients (15.8%) experienced bleeding after the endoscopic procedure. One patient (0.99%) presented with spurting, while the others presented with mild oozing. All patients underwent hemostatic procedures using hemoclips. The presence of a varix significantly increased post-endoscopic bleeding (p = 0.03). Patients with FIB > 3.25 showed a statistically significant bleeding tendency (p = 0.00). Conclusions: There was no significant difference in bleeding risk according to the platelet count, prothrombin time, Child–Pugh score, and model for end-stage liver disease (MELD). Considering the degree of liver fibrosis and the invasiveness of the planned procedure, most endoscopic procedures can be performed safely but should be further evaluated in a cohort with a larger sample size.

Suh MA, et al. Yonsei Med J. 2023 Sep;64(9):549-557. https://doi.org/10.3349/ymj.2023.0074