Publications by authors named "Kyoung-Sun Kim"

21 Publications

  • Page 1 of 1

Association of skeletal muscle index with postoperative acute kidney injury in living donor hepatectomy: A retrospective single-centre cohort study.

Liver Int 2021 Nov 24. Epub 2021 Nov 24.

Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Background: Although living donor liver transplantation (LDLT) is the standard treatment option for patients with end-stage liver disease, it always entails ethical concerns about the risk of living donors. Recent studies have reported a correlation between sarcopenia and surgical prognosis in recipients. However, there are few studies of donor sarcopenia and the surgical prognosis of donors. This study investigated the association between sarcopenia and postoperative acute kidney injury in liver donors.

Methods: This retrospective study analysed 2892 donors who underwent donor hepatectomy for LDLT between January 2008 and January 2018. Sarcopenia was classified into pre-sarcopenia and severe sarcopenia, which were determined to be -1 standard deviation (SD), and -2 SD from the mean baseline of the skeletal muscle index, respectively. Multivariate regression analysis was performed to evaluate the association between donor sarcopenia and postoperative AKI. Additionally, we assessed the association between donor sarcopenia and delayed recovery of liver function (DRHF).

Results: In the multivariate analysis, donor sarcopenia was significantly associated a higher incidence of postoperative AKI (adjusted odds ratio [OR]: 2.65, 95% confidence interval [CI]: 1.15-6.11, P = .022 in pre-sarcopenia, OR: 5.59, 95% CI: 1.11-28.15, P = .037 in severe sarcopenia, respectively). Additionally, hypertension and synthetic colloid use were significantly associated with postoperative AKI. In the multivariate analysis, risk factors of DRHF were male gender, indocyanine green retention rate at 15 minutes, and graft type, however, donor sarcopenia was not a risk factor.

Conclusions: Donor sarcopenia is associated with postoperative AKI following donor hepatectomy.
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http://dx.doi.org/10.1111/liv.15109DOI Listing
November 2021

Low Preoperative Antithrombin III Level Is Associated with Postoperative Acute Kidney Injury after Liver Transplantation.

J Pers Med 2021 Jul 26;11(8). Epub 2021 Jul 26.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.

We aimed to determine the association between the preoperative antithrombin III (ATIII) level and postoperative acute kidney injury (AKI) after LT (post-LT AKI). We retrospectively evaluated 2395 LT recipients between 2010 and 2018 whose data of perioperative ATIII levels were available. Patients were divided into two groups based on the preoperative level of ATIII (ATIII < 50% vs. ATIII ≥ 50%). Multivariable regression analysis was performed to assess the risk factors for post-LT AKI. The mean preoperative ATIII levels were 30.2 ± 11.8% in the ATIII < 50% group and 67.2 ± 13.2% in the ATIII ≥ 50% group. The incidence of post-LT AKI was significantly lower in the ATIII ≥ 50% group compared to that in the ATIII < 50% group (54.7% vs. 75.5%, < 0.001); odds ratio (OR, per 10% increase in ATIII level) 0.86, 95% confidence interval (CI) 0.81-0.92; < 0.001. After a backward stepwise regression model, female sex, high body mass index, low albumin, deceased donor LT, longer duration of surgery, and high red blood cell transfusion remained significantly associated with post-LT AKI. A low preoperative ATIII level is associated with post-LT AKI, suggesting that preoperative ATIII might be a prognostic factor for predicting post-LT AKI.
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http://dx.doi.org/10.3390/jpm11080716DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401622PMC
July 2021

Association between Neutrophil-Lymphocyte Ratio and Herpes Zoster Infection in 1688 Living Donor Liver Transplantation Recipients at a Large Single Center.

Biomedicines 2021 Aug 5;9(8). Epub 2021 Aug 5.

Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.

Liver transplantation (LT) is closely associated with decreased immune function, a contributor to herpes zoster (HZ). However, risk factors for HZ in living donor LT (LDLT) remain unknown. Neutrophil-lymphocyte ratio (NLR) and immune system function are reportedly correlated. This study investigated the association between NLR and HZ in 1688 patients who underwent LDLT between January 2010 and July 2020 and evaluated risk factors for HZ and postherpetic neuralgia (PHN). The predictive power of NLR was assessed through the concordance index and an integrated discrimination improvement (IDI) analysis. Of the total cohort, 138 (8.2%) had HZ. The incidence of HZ after LT was 11.2 per 1000 person-years and 0.1%, 1.3%, 2.9%, and 13.5% at 1, 3, 5, and 10 years, respectively. In the Cox regression analysis, preoperative NLR was significantly associated with HZ (adjusted hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.02-1.09; = 0.005) and PHN (HR, 1.08; 95% CI, 1.03-1.13; = 0.001). Age, sex, mycophenolate mofetil use, and hepatitis B virus infection were risk factors for HZ versus age and sex for PHN. In the IDI analysis, NLR was discriminative for HZ and PHN ( = 0.020 and = 0.047, respectively). Preoperative NLR might predict HZ and PHN in LDLT recipients.
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http://dx.doi.org/10.3390/biomedicines9080963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8391531PMC
August 2021

Tachycardia-polyuria syndrome after swan-ganz catheterization in liver transplant patient - A case report.

Anesth Pain Med (Seoul) 2021 Jul 6;16(3):284-289. Epub 2021 Jul 6.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background: Tachycardia-polyuria syndrome is characterized by polyuria occurring because of tachycardia with a heart rate of ≥ 120 beats/min lasting ≥ 30 min. We report such a case occurring after swan-ganz catheterization.

Case: A 41-year-old male was scheduled for living-donor liver transplantation. After general anesthesia, atrial fibrillation occurred during swan-ganz catheterization, and polyuria developed 1 h later. During the anhepatic phase, the patient's heart rate increased further, and cardioversion was performed. After a normal sinus rhythm was achieved, the patient's urine output returned to normal.

Conclusions: The patient's polyuria seemed related to the iatrogenic atrial fibrillation occurring during swan-ganz catheterization. Although we did not measure atrial natriuretic peptide, an increase in its concentration may have been the main mechanism of polyuria, as natriuresis was observed.
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http://dx.doi.org/10.17085/apm.21008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8342823PMC
July 2021

Critical Role of Ti in Stabilizing High-Voltage Redox Reactions in Li-Rich Layered Material.

Small 2021 Aug 1;17(32):e2100840. Epub 2021 Jul 1.

Neutron Science Division, Korea Atomic Energy Research Institute (KAERI), 111 Daedeok-daero 989 Beon-Gil, Yuseong-gu, Daejeon, 34 057, Republic of Korea.

Li-rich layered oxide materials are considered promising candidates for high-capacity cathodes for battery applications and improving the reversibility of the anionic redox reaction is the key to exploiting the full capacity of these materials. However, permanent structural change of the electrode occurring upon electrochemical cycling results in capacity and voltage decay. In view of these factors, Ti -substituted Li IrO (Li Ir Ti O ) is synthesized, which undergoes an oxygen redox reaction with suppressed voltage decay, yielding improved electrochemical performance and good capacity retention. It is shown that the increased bond covalency upon Ti substitution results in structural stability, tuning the phase stability from O3 to O1' upon de-lithiation during charging compared with O3 to T3 and O1 for pristine Li IrO , thereby facilitating the oxidation of oxygen. This work unravels the role of Ti in stabilizing the cathode framework, providing insight for a fundamental design approach for advanced Li-rich layered oxide battery materials.
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http://dx.doi.org/10.1002/smll.202100840DOI Listing
August 2021

Rupture Risk of Intracranial Aneurysm and Prediction of Hemorrhagic Stroke after Liver Transplant.

Brain Sci 2021 Mar 31;11(4). Epub 2021 Mar 31.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.

Postoperative hemorrhagic stroke (HS) is a rare yet devastating complication after liver transplantation (LT). Unruptured intracranial aneurysm (UIA) may contribute to HS; however, related data are limited. We investigated UIA prevalence and aneurysmal subarachnoid hemorrhage (SAH) and HS incidence post-LT. We identified risk factors for 1-year HS and constructed a prediction model. This study included 3544 patients who underwent LT from January 2008 to February 2019. Primary outcomes were incidence of SAH, HS, and mortality within 1-year post-LT. Propensity score matching (PSM) analysis and Cox proportional hazard analysis were performed. The prevalence of UIAs was 4.63% ( = 164; 95% confidence interval (CI), 3.95-5.39%). The 1-year SAH incidence was 0.68% (95% CI, 0.02-3.79%) in patients with UIA. SAH and HS incidence and mortality were not different between those with and without UIA before and after PSM. Cirrhosis severity, thrombocytopenia, inflammation, and history of SAH were identified as risk factors for 1-year HS. UIA presence was not a risk factor for SAH, HS, or mortality in cirrhotic patients post-LT. Given the fatal impact of HS, a simple scoring system was constructed to predict 1-year HS risk. These results enable clinical risk stratification of LT recipients with UIA and help assess perioperative HS risk before LT.
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http://dx.doi.org/10.3390/brainsci11040445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8066281PMC
March 2021

Systolic anterior motion of mitral chordae tendineae: prevalence and clinical implications in liver transplantation.

Anesth Pain Med (Seoul) 2020 Apr 11;15(2):187-192. Epub 2020 Mar 11.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background: Although systolic anterior motion (SAM) of the mitral valve anterior leaflet is well-known to cause hemodynamic perturbation in many anesthetic situations, the prevalence and clinical implication of SAM of mitral chordae tendineae (chordal SAM) in liver transplantation (LT) has not been evaluated. We aimed to assess the impact of chordal SAM on intraoperative postreperfusion syndrome and short and long-term all-cause mortality.

Methods: We retrospectively evaluated 1751 LT recipients from January 2011 to June 2017 who had preoperative echocardiography. Echocardiography-derived parameters and the prevalence of post-reperfusion syndrome between those with chordal SAM and without chordal SAM were compared. The cumulative mortality rate according to the presence of chordal SAM was evaluated by the Kaplan-Meier survival curve.

Results: Of the enrolled recipients, 21 (1.2%) had chordal SAM in preoperative echocardiography. Compared to those without chordal SAM, patients with chordal SAM had a smaller end-systolic volume index (median 18 ml/m vs. 22 ml/m, P = 0.015) and end-diastolic volume index (median 52 ml/m vs. 63 ml/m, P = 0.011). However, there was no difference in systolic and diastolic function in echocardiography. The prevalence of intraoperative post-reperfusion syndrome did not show any difference (42.9% vs. 45.3%, P = 1.000). Over the mean 4.8-year follow-up, cumulative 90-day and overall mortality also did not show a difference (Log rank P > 0.05, both).

Conclusions: Preoperative screening of echocardiography in LT recipients detects 1.2% of chordal SAM. It is found with small left ventricular volume, but is not related with intraoperative post-reperfusion syndrome and short- and long-term postoperative all-cause mortality in LT.
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http://dx.doi.org/10.17085/apm.2020.15.2.187DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7713819PMC
April 2020

Changes in diaphragmatic excursion and lung compliance during gynaecologic surgery: open laparotomy versus laparoscopy-a prospective observational study.

Sci Rep 2020 12 8;10(1):21458. Epub 2020 Dec 8.

Laboratory for Cardiovascular Dynamics, Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.

This study compared the effects of open versus laparoscopic radical hysterectomy on intraoperative diaphragmatic excursion and lung compliance. We enrolled 20 women per group; Group O's members underwent open radical hysterectomy, while Group L's members underwent laparoscopic radical hysterectomy. Diaphragmatic excursion was measured by assessing tidal ventilation using M-mode ultrasonography before intubation (T0), after intubation with mechanical ventilation (T1), 90 min after incision (T2), and at the end of the operation with recovery of muscle relaxation (T3). Peak inspiratory pressure and static lung compliance were measured using an anaesthesia machine combined with a ventilator. Diaphragmatic excursion was significantly lower in Group L than in Group O at T2 (5.3 ± 1.7 mm vs. 7.7 ± 2.0 mm, P < 0.001) and T3 (8.4 ± 1.9 vs. 10.4 ± 2.4, P = 0.011). Impaired diaphragmatic excursion at T3 (< 10 mm under mechanical ventilation) occurred in 15 patients (83.3%) in Group L and seven (38.9%) in Group O (P = 0.006). Changes over time in peak inspiratory pressure and static lung compliance differed significantly between the two groups (P < 0.001 each). Laparoscopic radical hysterectomy decreased diaphragmatic excursion and static lung compliance significantly more than open radical hysterectomy.Korean clinical trial number: Korean Clinical Trials Registry (KCT0004477) (Date of registration: November 18 2019) ( https://cris.nih.go.kr/cris/search/search_result_st01_en.jsp?seq=14963<ype=&rtype= ).
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http://dx.doi.org/10.1038/s41598-020-78375-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7722851PMC
December 2020

Prognostic Value of B-Type Natriuretic Peptide in Liver Transplant Patients: Implication in Posttransplant Mortality.

Hepatology 2021 Jul 15;74(1):336-350. Epub 2021 Jun 15.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea.

Background And Aims: Despite frequent cirrhotic cardiomyopathy or subclinical heart failure (HF), the prognostic value of peri-liver transplant (LT) B-type natriuretic peptide (BNP) has been poorly studied in advanced liver disease. We examined the association between BNP and mortality in a large cohort of LT patients and identified risk factors for peri-LT BNP increase.

Approach And Results: Using prospectively collected data from the Asan LT Registry between 2008 and 2019, 3,811 patients who measured serial pretransplant BNP (preBNP) and peak BNP levels within the first 3 posttransplant days (postBNP ) were analyzed. Thirty-day all-cause mortality predicted by adding preBNP and/or postBNP to the traditional Revised Cardiac Risk Index (RCRI) was evaluated. PreBNP > 400 pg/mL (known cutoff of acute HF) was found in 298 (7.8%); however, postBNP  > 400 pg/mL was identified in 961 (25.2%) patients, specifically in 40.4% (531/1,315) of those with a Model for End-Liver Disease score (MELDs) > 20. Strong predictors of postBNP  > 400 pg/mL were preBNP, hyponatremia, and MELDs, whereas those of preBNP > 400 pg/mL were MELDs, kidney failure, and respiratory failure. Among 100 (2.6%) post-LT patients who died within 30 days, patients with postBNP  ≤ 150 pg/mL (43.1%, reference group), 150-400 pg/mL (31.7%), 400-1,000 pg/mL (18.5%), 1,000-2,000 pg/mL (4.7%), and >2,000 pg/mL (2.0%) had 30-day mortalities of 0.9%, 2.2%, 4.0%, 7.7%, and 22.4%, respectively. Adding preBNP, postBNP , and both BNP to RCRI improved net reclassification index to 22.5%, 29.5%, and 33.1% of 30-day mortality, respectively.

Conclusions: PostBNP  > 400 pg/mL after LT was markedly prevalent in advanced liver disease and mainly linked to elevated preBNP. Routine monitoring of peri-LT BNP provides incremental prognostic information; therefore, it could help risk stratification for mortality as a practical and useful biomarker in LT.
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http://dx.doi.org/10.1002/hep.31661DOI Listing
July 2021

von Willebrand factor to protein C ratio-related thrombogenicity with systemic inflammation is predictive of graft dysfunction after liver transplantation: Retrospective cohort study.

Int J Surg 2020 Dec 1;84:109-116. Epub 2020 Nov 1.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address:

Introduction: Early allograft dysfunction (EAD) is known to be a prototype of graft failure and ultimately influences long-term graft failure or death. We hypothesized that pretransplant thrombogenicity evaluated by procoagulant and anticoagulant, von Willebrand factor (vWF), factor Ⅷ (FⅧ), protein C (PC) and their imbalance ratio of vWF-to-PC (vWFPCR) and FVIII-to-PC (FⅧPCR), is associated with EAD and 90-day graft failure after living-related liver transplantation (LDLT) and contributes to further exacerbation of graft dysfunction when coexists with systemic inflammation.

Material And Methods: Of 1199 prospectively registered LDLT patients, 698 with measurements of each thrombogenicity parameters were analyzed. Risk factors for EAD development were searched and subsequent best cut-offs was calculated according to the receiver operator characteristic curve analysis. When comparing the outcome, multivariable regression analysis and inverse probability of treatment weighting (IPTW) of the propensity score were performed.

Results: The prevalence of EAD was 10.7% (n = 75/698) after LDLT. Of parameters, vWFPCR had highest predictivity potential of EAD with the best cut-off of 8.06. The relationship between vWFPCR≥8.06 showed significant association with EAD development (OR [95%CI], 2.55[1.28-5.09], P = 0.008) and 90-day graft failure (HR [95%CI], 2.24 [1-4.98], P = 0.043) after IPTW-adjustment. Furthermore, risk of EAD increased proportionally with increasing C-reactive protein as a continuous metric of systemic inflammation, and more steeply in those with higher thrombogenicity (i.e., higher vWFPCR). Adding vWFPCR to MELD score improved EAD risk prediction by 21.9%.

Conclusions: Pretransplant thrombogenicity assessed by imbalance of pro- and anticoagulant, was significantly associated with EAD and 90-day graft failure after LDLT and this association was worsened by systemic inflammation.
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http://dx.doi.org/10.1016/j.ijsu.2020.10.030DOI Listing
December 2020

Preoperative high-sensitivity troponin I and B-type natriuretic peptide, alone and in combination, for risk stratification of mortality after liver transplantation.

Korean J Anesthesiol 2021 06 26;74(3):242-253. Epub 2020 Aug 26.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background: Given the severe shortage of donor liver grafts, coupled with growing proportion of cardiovascular death after liver transplantation (LT), precise cardiovascular risk assessment is pivotal for selecting recipients who gain the greatest survival benefit from LT surgery. We aimed to determine the prognostic value of pre-LT combined measurement of B-type natriuretic peptide (BNP) and high-sensitivity troponin I (hsTnI) in predicting early post-LT mortality.

Methods: We retrospectively evaluated 2,490 consecutive adult LT patients between 2010 and 2018. Cut-off values of BNP and hsTnI for predicting post-LT 90-day mortality were calculated. According to the derived cut-off values of two cardiac biomarkers, alone and in combination, adjusted hazard ratios (aHR) of post-LT 90-day mortality were determined using multivariate Cox regression analysis.

Results: Mortality rate after 90 days was 2.9% (72/2,490). Rounded cut-off values for post-LT 90-day mortality were 400 pg/ml for BNP (aHR 2.02 [1.15, 3.52], P = 0.014) and 60 ng/L for hsTnI (aHR 2.65 [1.48, 4.74], P = 0.001), respectively. Among 273 patients with BNP ≥ 400 pg/ml, 50.9% of patients were further stratified into having hsTnI ≥ 60 ng/L. Combined use of pre-LT cardiac biomarkers predicted post-LT 90-day mortality rate; both non-elevated: 1.0% (21/2,084), either one is elevated: 9.0% (24/267), and both elevated: 19.4% (27/139, log-rank P < 0.001; aHR vs non-elevated 4.23 [1.98, 9.03], P < 0.001).

Conclusions: Concomitant elevation of both cardiac biomarkers posed significantly higher risk of 90-day mortality after LT. Pre-LT assessment cardiac strain and myocardial injury, represented by BNP and hsTnI values, would contribute to prioritization of LT candidates and help administer target therapies that could modify early mortality.
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http://dx.doi.org/10.4097/kja.20296DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8175877PMC
June 2021

Markedly prolonged QTc interval in end-stage liver disease and risk of 30-day cardiovascular event after liver transplant.

J Gastroenterol Hepatol 2021 Mar 30;36(3):758-766. Epub 2020 Jul 30.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background And Aim: The proportional increase of corrected QT interval (QTc) along end-stage liver disease (ESLD) severity may lead to inconsistent outcome reporting if based on conventional threshold of prolonged QTc. We investigated the comprehensive QTc distribution among ESLD patients and assessed the association between QTc > 500 ms, a criterion for diagnosing severe long-QT syndrome, and the 30-day major adverse cardiovascular event (MACE) after liver transplantation (LT) and identified the risk factors for developing QTc > 500 ms.

Methods: Data were collected prospectively from the Asan LT Registry between 2011 and 2018, and outcomes were retrospectively reviewed. Multivariable analysis and propensity score-weighted adjusted odds ratios (ORs) were calculated. Thirty-day MACEs were defined as the composite of cardiovascular mortality, arrhythmias, myocardial infarction, pulmonary thromboembolism, and/or stroke.

Results: Of 2579 patients, 194 (7.5%) had QTc > 500 ms (QTc500_Group), and 1105 (42.8%) had prolonged QTc (QTcP_Group), defined as QTc > 470 ms for women and >450 ms for men. The 30-day MACE occurred in 336 (13%) patients. QTc500_Group showed higher 30-day MACE than did those without (20.1% vs 12.5%, P = 0.003), with corresponding adjusted OR of 1.24 (95% CI: 1.06-1.46, P = 0.007). However, QTcP_Group showed comparable 30-day MACE (13.3% vs 12.8% without prolonged QTc, P = 0.764). Significant risk factors for QTc > 500 ms development were advanced liver disease, female sex, hypokalemia, hypocalcemia, high left ventricular end-diastolic volume, and tachycardia.

Conclusion: Our results revealed that, among ESLD patients, a novel threshold of QTc > 500 ms was associated with post-LT 30-day MACE but not with conventional threshold, indicating that a longer QTc threshold should be considered for this unique patient population.
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http://dx.doi.org/10.1111/jgh.15179DOI Listing
March 2021

Preoperative echocardiographic evaluation of cardiac systolic and diastolic function in liver transplant recipients with diabetes mellitus: a propensity-score matched analysis.

Anesth Pain Med (Seoul) 2019 Oct;14(4):465-473

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background: Diabetes mellitus (DM) increases risk of heart failure. It has been shown that diabetes leads to DM-cardiomyopathy, characterized by systolic and diastolic dysfunction. Pre-transplant diastolic dysfunction, has been associated with poor graft outcome and mortality. We assessed the hypothesis that end-stage liver disease (ESLD) patients with diabetes (DM-ESLD), have more advanced cardiac systolic and diastolic dysfunction, compared to ESLD patients without diabetes (Non DM-ESLD).

Methods: We retrospectively evaluated preoperative echocardiography of 1,319 consecutive liver transplant recipients (1,007 Non DM-ESLD vs. 312 DM-ESLD [23.7%]) January 2012-May 2016. Systolic and diastolic indices, such as left ventricular ejection fraction, transmital E/A ratio, tissue doppler s', e' velocity, and E/e' ratio (index of left ventricular end-diastolic pressure), were compared using 1:2 propensity-score matching.

Results: DM-ESLD patients showed no differences in systolic indices of left ventricular ejection fraction and s' velocity, whereas diastolic indices of E/A ratio ≤ 1 (49.0% vs. 40.2% P = 0.014), e' velocity (median = 7.0 vs. 7.4 cm/s, P < 0.001) and E/e' ratio (10.9 ± 3.2 vs. 10.1 ± 3.0, P < 0.001), showed worse diastolic function compare with Non DM-ESLD patients, respectively.

Conclusions: DM-ESLD patients suffer higher degree of diastolic dysfunction compared with Non DM-ESLD patients. Based on this, careful preoperative screening for diastolic dysfunction in DM-ESLD patients is encouraged, because poor transplant outcomes have been noted in patients with preoperative diastolic dysfunction.
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http://dx.doi.org/10.17085/apm.2019.14.4.465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7713801PMC
October 2019

Appraisal of Cardiac Ejection Fraction With Liver Disease Severity: Implication in Post-Liver Transplantation Mortality.

Hepatology 2020 04 6;71(4):1364-1380. Epub 2020 Mar 6.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Background And Aims: Enhanced sympathetic nervous activation and peripheral vasodilation in end-stage liver disease (ESLD) may limit the importance of left ventricular ejection fraction (LVEF) as an influential prognosticator. We sought to understand the LVEF and cardiac dimensions in ESLD patients in order to define the LVEF threshold to predict all-cause mortality after liver transplantation (LT).

Approach And Results: Data were collected prospectively from the Asan LT Registry between 2008 and 2016, and outcomes were retrospectively reviewed. LVEF, end-diastolic volume index (EDVI), and end-diastolic elastance (Eed) were measured by preoperative echocardiography. Of 2,799 patients, 452 (16.2%) had LVEF ≤ 60%, with 29 (1.0%) having LVEF < 55% and 269 (9.6%) had LVEF ≥ 70%. Over a median of 5.4-year follow-up, 329 (11.8%) patients died: 104 (3.7%) died within 90 days. LVEF (range, 30%-81%) was directly proportionate to Model for End-stage Liver Disease (MELD) scores, an index of liver disease severity, in survivors but showed a fixed flat-line pattern in nonsurvivors (interaction P = 0.004 between groups), with lower EDVI (P = 0.013) and higher Eed (P = 0.001) in the MELD ≥ 20 group. Patients with LVEF ≤ 60% had higher 90-day (13% vs. 7.4%; log rank, P = 0.03) and median 5.4-year (26.7% vs. 16.2%; log rank, P = 0.003) mortality rates in the MELD ≥ 20 group, respectively, compared to those with LVEF > 60%. Specifically, in the MELD > 35 group, median 5.4-year mortality rate was 53.3% in patients with LVEF ≤ 60% versus 24% in those with LVEF > 60% (log rank P < 0.001). By contrast, mortality rates of LVEF ≤ 60% and > 60% were similar in the MELD < 20 group (log rank P = 0.817).

Conclusions: LVEF ≤ 60% is strongly associated with higher post-LT mortality rates in the MELD ≥ 20 group, indicating the need to appraise both LVEF and liver disease severity simultaneously. Enhanced diastolic elastance with low EDVI provides insights into pathogenesis of low LVEF in nonsurvivors with MELD ≥ 20.
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http://dx.doi.org/10.1002/hep.30913DOI Listing
April 2020

Preoperative Myocardial Ischemia Detected With Electrocardiography Is Associated With Reduced 1-Year Survival Rate in Patients Undergoing Liver Transplant.

Transplant Proc 2019 Oct 22;51(8):2755-2760. Epub 2019 Jul 22.

Department of Anesthesiology and Pain Medicine, Laboratory for Cardiovascular Dynamics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background: Although electrocardiography (ECG) is routinely used as a preoperative cardiac assessment tool, impact of ECG-detected myocardial ischemia on postoperative outcomes remains unclear. We aimed to assess use of ECG as a predictor of postoperative mortality in patients undergoing liver transplant (LT).

Methods: Electronic medical records of patients who underwent LT were retrospectively analyzed. The primary end point was postoperative 1-year all-cause mortality. Electrocardiographic myocardial ischemia was diagnosed based on automated ECG interpretation suggesting ischemia or infarction. Cox proportional hazard analysis was performed to identify independent risk factors including Model for End-Stage Liver Disease score, revised cardiac risk index, echocardiographic wall motion abnormalities, and myocardial perfusion scan (MPS) abnormalities.

Results: Of the 1430 patients, 78 (5.5%) showed ischemic change on ECG. The 1-year mortality of patients with ischemic change on ECG was significantly higher than that of those without (11.5% vs 4.0%; P = .004). In the Cox proportional hazard model, ischemic change on ECG (hazard ratio [HR], 2.91; 95% CI, 1.43-5.92; P = .003), Model for End-Stage Liver Disease score (HR 1.06; 95% CI 1.04-1.09; P < .001), and revised cardiac risk index (HR, 2.84; 95% CI, 1.86-4.35; P < .001) were independent variables predicting 1-year mortality; however, MPS abnormalities and echocardiographic wall motion abnormalities were not.

Conclusion: In patients undergoing LT, preoperative ischemic ECG findings should not be overlooked, as they are associated with increased mortality, while abnormalities on MPS and resting ECG are not. Thorough evaluations to detect underlying modifiable coronary artery disease are needed in patients with these findings.
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http://dx.doi.org/10.1016/j.transproceed.2019.02.063DOI Listing
October 2019

Physiological responses to short-term thermal stress in mayfly () larvae in relation to upper thermal limits.

J Exp Biol 2017 07;220(Pt 14):2598-2605

Graduate Toxicology Program, Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA

Understanding species' thermal limits and their physiological determinants is critical in light of climate change and other human activities that warm freshwater ecosystems. Here, we ask whether oxygen limitation determines the chronic upper thermal limits in larvae of the mayfly , an emerging model for ecological and physiological studies. Our experiments are based on a robust understanding of the upper acute (∼40°C) and chronic thermal limits of this species (>28°C, ≤30°C) derived from full life cycle rearing experiments across temperatures. We tested two related predictions derived from the hypothesis that oxygen limitation sets the chronic upper thermal limits: (1) aerobic scope declines in mayfly larvae as they approach and exceed temperatures that are chronically lethal to larvae; and (2) genes indicative of hypoxia challenge are also responsive in larvae exposed to ecologically relevant thermal limits. Neither prediction held true. We estimated aerobic scope by subtracting measurements of standard oxygen consumption rates from measurements of maximum oxygen consumption rates, the latter of which was obtained by treating with the metabolic uncoupling agent carbonyl cyanide-4-(trifluoromethoxy) pheylhydrazone (FCCP). Aerobic scope was similar in larvae held below and above chronic thermal limits. Genes indicative of oxygen limitation (LDH, EGL-9) were only upregulated under hypoxia or during exposure to temperatures beyond the chronic (and more ecologically relevant) thermal limits of this species (LDH). Our results suggest that the chronic thermal limits of this species are likely not driven by oxygen limitation, but rather are determined by other factors, e.g. bioenergetics costs. We caution against the use of short-term thermal ramping approaches to estimate critical thermal limits (CT) in aquatic insects because those temperatures are typically higher than those that occur in nature.
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http://dx.doi.org/10.1242/jeb.156919DOI Listing
July 2017

Crystal structure and spontaneous magnetism of BiFeO3 powder synthesized by hydrothermal method.

J Nanosci Nanotechnol 2010 Oct;10(10):6650-4

Department of Materials Science and Engineering, KAIST, Daejeon 305-701, Korea.

Single-phase BiFeO3 powder was successively synthesized by a low-temperature hydrothermal method. Scanning electron microscopy and transmission electron microscopy results showed that BiFeO3 powder had several hundred nanometers to micrometer-sized particles with a broad size distribution. BiFeO3 powder showed weak-ferromagnetic behavior with a small magnetization value (Ms approximately 20 memu/g) at room temperature. Rietveld refinement results for the crystal structure show the displacive disorder of the Fe-site(6a); the Fe-site(6a) splits into two pairs, Fe(1) and Fe(2) displaced by 0.9 angstroms from each other and these sites are partially occupied. Hence the O-site(18b) also splits into the two partially occupied sites forming a distorted FeO6 octahedras. The weak ferromagnetism observed in the hydrothermal BFO powder is ascribed to the displacive disorder of FeO6 octahedras resulting in an incomplete counterbalance between the antiferromagnetic sublattices of the Fe-ions.
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http://dx.doi.org/10.1166/jnn.2010.3055DOI Listing
October 2010

Characterization of two vitellogenin cDNAs from a Pandalus shrimp (Pandalopsis japonica): expression in hepatopancreas is down-regulated by endosulfan exposure.

Comp Biochem Physiol B Biochem Mol Biol 2010 Sep 21;157(1):102-12. Epub 2010 May 21.

Department of Marine Biology, Pukyong National University, Busan 608-737, South Korea.

Endosulfan is a neurotoxic organochlorine insecticide of the cyclodiene family of pesticides that inhibits molting and reproduction in aquatic crustaceans. In order to determine the molecular mechanism of endosulfan as an endocrine disrupting chemical (EDC), differential display RT-PCR (DDRT-PCR) was used to isolate genes in the shrimp, Pandalopsis japonica, affected by endosulfan exposure. PCR screening of cDNA from the hepatopancreas from control and endosulfan-exposed animals, using 120 sets of random primers, yielded partial cDNAs encoding two vitellogenin-like proteins (Pj-Vg1 and -Vg2). Complete sequences were obtained using a combination of RT-PCR and RACE-PCR. Pj-Vg1 (7883bp) encoded a protein composed of 2533 amino acid residues (283.27 kDa estimated mass), whereas Pj-Vg2 (7792 bp) encoded a protein composed of 2537 amino acids residues (284.87 kDa estimated mass). Alignment of the Pj-Vgs with those of other vitellogenins identified a conserved subtilisin cleavage site (RQKR) and the lipoprotein N-terminal (vitellin), DUF1081, and von Willebrand factor type D domains, indicating both genes encoded functional proteins. Phylogenetic analysis showed that Pj-Vg1 and -Vg2 were most similar to Pandalus hypsinotus Vg. Both Pj-Vg1 and -Vg2 were expressed primarily in the hepatopancreas, although the Pj-Vg2 transcript was also detected in the ovary. The effects of the 3-day endosulfan exposure (2.5 microg/L and 25 microg/L) on Vg expression in the hepatopancreas were determined by quantitative RT-PCR. Expression of both transcripts was significantly inhibited at 25 microg/L suggesting that Pj-Vgs can be used as indicator for endosulfan exposure.
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http://dx.doi.org/10.1016/j.cbpb.2010.05.006DOI Listing
September 2010

Molecular cloning, tissue distribution and quantitative analysis of two proopiomelanocortin mRNAs in Japanese flounder (Paralichthys olivaceus).

BMB Rep 2009 Apr;42(4):206-11

Department of Marine Biology, Pukyong National University, Busan 608-737, Korea.

Proopiomelanocortin (POMC) plays an essential role in the stress response of the hypothalamic-pituitary-adrenal axis, and is the precursor of biologically active peptides such as adrenocorticotropin (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), beta-melanocyte-stimulation hormone (beta-MSH) and beta-endorphin. We have synthesized two different forms of POMC cDNA clones, POMC-I and POMC-II, from a pituitary cDNA library for Paralichthys olivaceus, or Japanese flounder. jfPOMC-I cDNA consists of 954bp and encodes a polypeptide of 216 amino acid residues, whereas jfPOMC-II consists of 971bp which encode a polypeptide of 194 amino acid residues. The high levels of jfPOMC-I and -II mRNAs detected in the pituitary tissue and moderate levels detected in the brain tissue plus our quantitative RT-PCR analysis, which showed there to be no significant difference between the levels of jfPOMC-I and -II mRNAs, indicate that there may be no functional separation between these two mRNAs in the flounder.
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http://dx.doi.org/10.5483/bmbrep.2009.42.4.206DOI Listing
April 2009

Twelve actin-encoding cDNAs from the American lobster, Homarus americanus: cloning and tissue expression of eight skeletal muscle, one heart, and three cytoplasmic isoforms.

Comp Biochem Physiol B Biochem Mol Biol 2009 Jun 1;153(2):178-84. Epub 2009 Mar 1.

Department of Marine Biology, Pukyong National University, Busan, 608-737 South Korea.

Lobster muscles express a diverse array of myofibrillar protein isoforms. Three fiber types (fast, slow-twitch or S1, and slow-tonic or S2) differ qualitatively and quantitatively in myosin heavy and light chains, troponin-T, -I, and -C, paramyosin, and tropomyosin variants. However, little is known about the diversity of actin isoforms present in crustacean tissues. In this report we characterized cDNAs that encode twelve actin isoforms in the American lobster, Homarus americanus: eight from skeletal muscle (Ha-ActinSK1-8), one from heart (Ha-ActinHT1), and three cytoplasmic type actins from hepatopancreas (Ha-ActinCT1-3). All twelve cDNAs were products of distinct genes, as indicated by differences in the 3'-untranslated regions (UTRs). The open reading frames specified polypeptides 376 or 377 amino acids in length. Although key amino residues are conserved in the lobster actins, variations in nearby sequences may affect actin polymerization and/or interactions with other myofibrillar proteins. Quantitative reverse transcription-polymerase chain reaction showed muscle fiber type- and tissue-specific expression patterns. Ha-Actin-HT1 was expressed exclusively in heart (87% of the total; 12% of the total was Ha-ActinCT1). Ha-ActinCT1 was expressed in all tissues, while CT2 and CT3 were expressed only in hepatopancreas, with Ha-ActinCT2 as the major isoform (93% of the total). Ha-ActinSK1 and SK2 were the major isoforms (88% and 12% of the total, respectively) in the S1 fibers of crusher claw closer muscle. Fast fibers in the cutter claw closer and deep abdominal muscles differed in SK isoforms. Ha-ActinSK3, SK4, and SK5 were the major isoforms in cutter claw closer muscle (12%, 48%, and 37% of the total, respectively). Ha-ActinSK5 and SK8 were the major isoforms in deep abdominal flexor (31% and 65% of the total, respectively) and extensor (46% and 53% of the total, respectively) muscles, with SK6 and SK7 expressed at low levels. These data indicate that fast fibers in cutter claw and abdominal muscles show a phenotypic plasticity with respect to the expression of actin isoforms and may constitute discrete subtypes that differ in contractile properties.
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http://dx.doi.org/10.1016/j.cbpb.2009.02.013DOI Listing
June 2009

Pancreatic lipase-related protein (PY-PLRP) highly expressed in the vitellogenic ovary of the scallop, Patinopecten yessoensis.

Comp Biochem Physiol B Biochem Mol Biol 2008 Sep 25;151(1):52-8. Epub 2008 May 25.

Department of Marine Biology, Pukyong National University, Busan 608-737, South Korea.

A cDNA (1206 bp) encoding a pancreatic lipase-related protein (PY-PLRP) was obtained from the ovary of the scallop, Patinopecten yessoensis, using a differentially expressed gene system. The open reading frame specified a protein containing 353 amino acids (~38 kDa). The N-terminal catalytic domain, which contained the catalytic triad of serine, aspartate, and histidine residues, 10 cysteine residues involved in disulfide bridges, and the conserved lid domain, indicated that the protein would be catalytically active. However, PY-PLRP lacked the C-terminal colipase-binding domain present in mammalian PLRPs. Sequence analysis of the catalytic domains of PY-PLRP with members of the pancreatic triglyceride lipase (PTL) family suggested that PY-PLRP was related to mammalian PLRP1, PLRP2, and PTL. End-point reverse transcriptase-polymerase chain reaction (RT-PCR) after 25 cycles showed that PY-PLRP was expressed at a high level in the ovary and at low levels in testis and mantle; expression was not detected in gill, digestive gland, and adductor muscle. Quantitative PCR of RNA from ovaries at different stages of development showed that PY-PLRP was expressed at a significantly higher level in the late growth stage than in the ripe and spent stages. These data suggest that PY-PLRP plays a role in lipid metabolism associated with oocyte maturation and vitellogenesis that occurs during ovarian growth.
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http://dx.doi.org/10.1016/j.cbpb.2008.05.009DOI Listing
September 2008
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