This study described methods to predict human health risk associated with exposure to environmental carciongens using animal bioassay data. Also, biological assumption for various dose-response models were reviewed. To illustrate the process of risk estimate using relevant dose-response models such as Log-normal, Mantel-Bryan, Weibull and Multistage model, we used four animal carcinogenesis bioassy data of chloroform and chloroform concentrations of tap water measured in large cities of korea from 1987 to 1995. As a result, in the case of using average concentration in exposure data and 95 % upper boud unit risk of Multistage model, excess cancer risk(RISK I) was about 1.9 x 10-6, in the case of using probability distribution of cumulative exposure data and unit risks, those risks(RISK II) which were simulated by Monte-Carlo analysis were about 2.4 x 10(-6) and 7.9 x 10(-5) at 50 and 95 percentile, respectively. Therefore risk estimated by Monte-Carlo analysis using probability distribution of input variables may be more conservative.
Animals ; Biological Assay ; Carcinogenesis ; Carcinogens, Environmental* ; Chloroform ; Humans ; Korea ; Water

Living liver donors (LLDs) are screened for transmissible diseases including cancer. We investigated the actual cancer incidence of LLDs compared with a matched healthy control group from the general Korean population using data from the Korean National Health Insurance Services (NHIS). A total of 12,372 LLDs who donated a liver graft between 2002 and 2018 were registered in the Korean Network for Organ Sharing. They were compared to a matched healthy control group selected from the Korean NHIS. Cancer diagnosis was identified in 175 LLDs (1.4%) and 1,014 controls (0.8%). Compared to the healthy control group, the incidence rate ratio of liver and thyroid cancer in the LLD group were significantly higher at 18.30 and 1.39, respectively. The incidences of 11 other specified cancers were not different between the two groups. The present study suggests that LLD after donor hepatectomy may require medical surveillance, especially for liver cancer.

Background: Liver transplant (LT) recipients were considered a vulnerable population during the coronavirus disease 2019 (COVID-19) pandemic. The clinical efficacy of the COVID-19 vaccine is unknown in immunocompromised patients. The purpose of this study was to provide evidence of antibody responses after COVID-19 vaccination in LT recipients. Methods: This study enrolled 46 patients who underwent LT at Samsung Medical Center (Seoul, Korea) before implementation of the one-dose vaccine in Korea. Those who completed the two-dose COVID-19 vaccine between August 2021 and September 2021 were included and followed through December 2021. Semiquantitative anti-spike serologic testing was performed using the Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay (Roche Diagnostics, Rotkereuz, Switzerland) with a positive cutoff of at least 0.8 U/mL. Results: Among all 46 participants, 40 (87%) demonstrated an antibody response after the second dose of a COVID-19 vaccine, while six (13%) had no antibody response after the second dose. Upon univariate analysis, patients with higher antibody titer had longer years since LT (2.3 ± 2.8 vs. 9.4 ± 5.0, P < 0.001). A lower median tacrolimus (TAC) level before vaccination and after the second dose of COVID-19 vaccine indicated a significantly higher antibody response (2.3 [1.6–3.2] vs. 7.0 [3.7–7.8], P = 0.006, 2.5 [1.6–3.3] vs. 5.7 [4.2–7.2], P = 0.003). Period between 2nd vaccination and serologic testing was significantly higher in the antibody-response group compared to the no-antibody-response group (30.2 ± 24.0 vs. 65.9 ± 35.0, P = 0.012). A multivariate analysis of antibody responses revealed TAC level before vaccination as a statistically significant factor. Conclusion A higher TAC level before vaccination resulted in less effective vaccination in LT patients. Booster vaccinations are required, especially for patients in the early stage after LT who have compromised immune function.

Background: /Aim: Hepatocellular carcinoma (HCC) tumor thrombi located in the first branch of the portal vein (Vp3) or in the main portal trunk (Vp4) are associated with poor prognosis. This study aimed to investigate the clinicopathological characteristics and risk factors for HCC recurrence and mortality following liver resection (LR) in patients with Vp3 or Vp4 HCC. Methods: The study included 64 patients who underwent LR for HCC with Vp3 or Vp4 portal vein tumor thrombosis (PVTT). Results: Fifty-eight patients (90.6%) had Vp3 PVTT, whereas the remaining six patients exhibited Vp4 PVTT. The median tumor size measured 8 cm, with approximately 36% of patients presented with multiple tumors. Fifty-four patients (84.4%) underwent open LR, whereas 10 patients underwent laparoscopic LR. In the Vp4 cases, combined LR and tumor thrombectomy were performed. The 3-year cumulative disease-free survival rate was 42.8% for the Vp3 group and 22.2% for the Vp4 group. The overall survival (OS) rate at 3 years was 47.9% for the Vp3 group and 60.0% for the Vp4 group. Intrahepatic metastasis has been identified as an important contributor to HCC recurrence. High hemoglobin levels are associated with high mortality. Conclusion LR is a safe and effective treatment modality for selected patients with Vp3 or Vp4 HCC PVTT. This suggests that LR is a viable option for these patients, with favorable outcomes in terms of OS.

PURPOSE: The avian origin canine influenza virus H3N2 has been recently isolated and found to be currently in dog population in South Korea and China. The purpose of this study was to clarify the relationship between immunosuppressive glucocorticoids used in veterinary clinical practice and viral shedding pattern of influenza in dogs. MATERIALS AND METHODS: Eight conventional beagle dogs were divided into control infection group and immunocompromised group. Dogs of both groups were infected with H3N2 canine influenza virus (2x106.0 EID50/0.1 mL). Dogs in immunocompromised group were given orally 3.0 mg/kg prednisolone for 7 days. Virus shedding was monitored using real-time polymerase chain reaction. After necropsy, histopathologic lesions were compared. RESULTS: We found that immunocompromised dogs exhibited more prolonged (8 days vs. 13 days) and higher magnitude viral shedding than control group (peak titer of viral shedding 4.6 vs. 5.5 EID50). CONCLUSION: Restricted use of immunosuppressive drugs in the clinical setting might help control the rapid spread of H3N2 through local dog populations.
Animals ; China ; Dogs ; Glucocorticoids ; Immunosuppression ; Influenza A Virus, H3N2 Subtype ; Influenza, Human ; Orthomyxoviridae ; Prednisolone ; Real-Time Polymerase Chain Reaction ; Republic of Korea ; Viral Load ; Virus Shedding

Purpose: Deceased donor liver transplantation (DDLT) recipients in Korea are generally sicker due to an increasing organ shortage. In the present study, the risk factors for early 30-day liver graft failure after DDLT were identified. Methods: From August 2017 to February 2021, 265 adult DDLTs were performed. The characteristics of patients with and without 30-day graft failure were compared. Results: Liver graft failure occurred in 11 patients (17.7%) after DDLT. Baseline and perioperative characteristics of donors and recipients were not statistically significantly different between the 2 groups. The cumulative graft and overall survival rates at 6 months were 83.9% and 88.7%, respectively. Multivariate analysis showed ventilator support in the pretransplant period was a predisposing factor for 30-day graft failure after DDLT. Conclusion Present study indicates that cautious decision is required when allocating DDLT in critically ill patients on mechanical ventilatory support.

PURPOSE: This study aimed to report intraoperative abortion of adult living donor liver transplantation (LDLT). METHODS: From June 1997 to December 2016, 1,179 adult LDLT cases were performed. 15 cases (1.3%) of intraoperative abortions in LDLT were described. RESULTS: Among 15 cases, 5 intraoperative abortions were donor-related, and remaining 10 cases were recipient-related. All donor-related abortions were due to unexpected steatohepatitis. Among remaining 10 recipient-related intraoperative abortions, unexpected extension of hepatocellular carcinoma was related in 5 cases. Two cases of intraoperative abortions were related to bowel inflammation, and 2 cases were associated with severe adhesion related to previous treatment. One recipient with severe pulmonary hypertension was also aborted. CONCLUSION: Complete prevention of aborted LDLT is still not feasible. In this regard, further efforts to minimize intraoperative abortion are required.
Adult* ; Carcinoma, Hepatocellular ; Fatty Liver ; Humans ; Hypertension, Pulmonary ; Inflammation ; Liver Transplantation* ; Liver* ; Living Donors* ; Postoperative Care

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients.The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold.Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cellmediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.