J.-W. Joh

The effects of desflurane and sevoflurane on hepatic and renal functions after right hepatectomy in living donors

We compared postoperative hepatic and renal functions between the two inhalational anesthetics, desflurane and sevoflurane in living donors undergoing right hepatectomy. Seventy‐four adult donors were randomly allocated into Des group (n = 37) and sevo group (n = 37). Before the induction of anesthesia, morphine sulfate 400 μg was injected intrathecally. Anesthesia was maintained with one minimum alveolar concentration (MAC) of deflurane or sevoflurane plus continuous intravenous remifentanil. Liver and renal function tests were performed and analysed at preoperative period, immediately after operation, and on 1st, 2nd, 3rd, 5th, 7th, and 30th postoperative days (PODs). Aspartate aminotransferase (AST) showed significant elevations from the day of surgery to POD 3 and alanine aminotransferase (ALT) was significantly elevated on POD 1 and POD 3 in the sevo group. Albumin level was significantly lower on POD 2 in the sevo group. Creatinine was significantly higher on POD 3 and POD 30 and estimated glomerular filtration ratio was significantly lower on POD 3 and POD 30 in the sevo group. No patient developed hepatic or renal failures. The results of our study showed better postoperative hepatic and renal function test with desflurane than sevoflurane at equivalent dose of 1 MAC in living donors undergoing right hepatectomy, but further study is required to evaluate clinical importance.

Development of Functional Human Immune System With the Transplantations of Human Fetal Liver/Thymus Tissues and Expanded Hematopoietic Stem Cells in RAG2―/―γc―/― MICE

BACKGROUND There is an increasing need for suitable animal models for the study of the human immune system and disease. The purpose of this study was to develop a practical in vivo model of human immune cell repopulation using ex vivo expanded human fetal liver-derived CD34(+) hematopoietic stem cells and subrenally coimplanted fetal liver/thymus tissues. METHODS Freshly isolated fetal liver-derived CD34(+) hematopoietic stem cells were frozen until injected and ex vivo expanded with various cytokines for 7 days. After fetal liver/thymus tissues were subrenally coimplanted into preirradiated Rag2(-/-)gamma(c)(-/-) mice, frozen and ex vivo expanded CD34(+) cells were injected intravenously. The peripheral blood of the mice was monitored for the detection of human cell engraftment using flow cytometry. Then we confirmed human T-cell function by in vitro function assays. RESULTS After fetal liver/thymus tissues were coimplanted into the irradiated Rag2(-/-)gamma(c)(-/-) mice, with frozen and ex vivo expanded CD34(+) hematopoietic stem cells, human cell engraftments were determined using hCD45 and multilineage markers. The cultured cells with the cytokine combination of stem cell factor, thrombopoietin, Flk2/Flk3 ligand (FL), and interleukin-3 showed stable and long-term engraftment compared to other combinations. The ex vivo expanded human fetal liver-derived CD34(+) hematopoietic stem cells, under our culture conditions, accomplished a large volume of expanded cells that were sustained, demonstrating self-renewal of the evaluated markers, which may have indicated long- term repopulation activity. CONCLUSION The results of this study demonstrated a practical mouse model of expanded human immune cells especially T cells in Rag2(-/-)gamma(c)(-/-) mice.

Single-Center Experience of Consecutive 522 Cases of Hepatic Artery Anastomosis in Living-Donor Liver Transplantation

OBJECTIVE The aim of this study was to clarify risk factors and outcome of hepatic arterial complication after living-donor liver transplantations (LDLT). METHODS From 2004 to 2010, 522 consecutive LDLTs were performed. We used univariate and multivariate analysis to identify the risk factor on a retrospective basis, and then analysis was performed for adult cases. Hepatic arterial complication included thrombosis, stenosis, and pseudoaneurysm. RESULTS The arterial complication rate was 4.79% (25 cases). Each complication was 9 thromboses, 14 stenoses, and 2 pseudoaneurysms. Preoperative hemoglobin was significantly associated with thrombosis (P = .021), and arterial size with stenosis (P = .037). We could not find any association between arterial complications and biliary stricture. However, the outcome of biliary stricture treatment was associated with arterial stenosis. Of 9 cases with thrombosis, 7 patients underwent rearterialization and 2 were treated with low-molecular-weight heparin (LMWH). Of 14 stenosis cases, 2 patients were treated with the use of balloon dilatation, 10 patients were observed under LMWH, and 2 patients underwent retransplantation. In cases of pseudoaneurysm, 1 patient underwent revision of the aneurysm and the other was observed. CONCLUSIONS In our cohort, preoperative low hemoglobin level was a risk factor for thrombosis and artery size a risk factor for stenosis.

Reconstitution of Human Lymphocytes Following Ex Vivo Expansion of Human Umbilical Cord Blood CD34+ Cells and Transplantation in Rag2-/-γc-/-Mice Model

BACKGROUND Due to ethical issues, in vivo studies of the human immune system have been difficult. Thus, small-animal xenotransplantation models have been employed, although they scarcely sustain a human immune response. In this study, we compared human cell repopulation tendencies and functionality in Rag2-/- gamma c-/- mice following various ex vivo expanded human hematopoietic stem cells (HSCs). METHODS Human umbilical cord blood (UCB) CD34+ cells were cultured for 7 days with a cytokine combination of stem cell factor, Flk2/Flt3 ligand, and thrombopoietin, with absence or presence of rhIL-3, then transplanted into Rag2-/- gamma c-/- mice. Reconstituted human lymphocytes were analyzed based on the expression of CD45 as well as CD3, CD19, and CD56 in peripheral blood (PB) until 16 weeks after transplantation. BrdU assay and functional analysis of reconstituted human lymphocytes used PHA- or rhIL-2-stimulated splenocytes and bone marrow cells from recipient mice. RESULTS The percentage of human CD45dim cells, not CD45bright cells, in PB of mice transplanted with cultured HSCs with rhIL-3 was much higher than in the group without rhIL-3 (approximately 2.5-fold at week 10 posttransplantation). The humanized mice showed systemic repopulation with a comprehensive array of human lymphohematopoietic cells, including T, B, natural killer (NK) cells, and even dendritic cells. However, the expression level was also dim. The number of CD3+ T cells and CD56+ NK cells was especially increased in the presence of rhIL-3. In addition, after in vitro restimulation proliferation assays and NK activity of interferon-gamma secretion showed greater effects in the presence of rhIL-3. CONCLUSION These data suggested that the development of a diverse repopulation of human lymphocytes was possible in Rag2-/- gamma c-/- mice after transplantation of cultured UCB CD34+ HSCs with interleukin-3.

The Effect of Human Fetal Liver-Derived Mesenchymal Stem Cells on CD34+ Hematopoietic Stem Cell Repopulation in NOD/Shi-scid/IL-2Rãnull Mice

Mesenchymal stem cells (MSCs) are progenitors that are capable of differentiating into mesenchymal tissues. They are known to support allogeneic hematopoietic stem cell transplantation by facilitating engraftment without increasing the risk of graft-versus-host disease. We optimized culture conditions for human fetal liver-derived MSCs (hFL-MSCs) to investigate the role of hFL-MSCs on repopulation of hematopoietic stem cells in NOD/Shi-scid/IL-2Rγ(null) (NOG) mice using CD34(+) hematopoietic stem cells (HSCs) derived from umbilical cord blood (UCB). FL-MSCs and CD34(+) HSCs were prepared from fetal liver and UCB, respectively. Twenty-four hours after irradiation, CD34(+) HSCs and hFL-MSCs were injected intravenously and intratibially into NOG mice. During 24 weeks posttransplantation, engraftment levels of human cells were analyzed in bone marrow, peripheral blood, and spleen of transplanted mice by flow cytometry. hFL-MSCs showed a fibroblast-like morphology and immunophenotypic characteristics appropriate for MSCs. hFL-MSCs prolonged the survival of NOG mice that had been cotransplanted with UCB CD34(+) cells. Fluorescence-activated cell-sorting analysis showed that engraftment of human cells was increased by cotransplantation of hFL-MSCs. However, significant enhancement of human cell engraftment was not detected in NOG mice regardless of the number of cotransplanted MSCs. Although survival of repopulating NOG mice and engraftment of human cells were prolonged by cotransplantation of hFL-MSCs, 8.0 × 10(6) MSCs were not sufficient to increase HSC engraftment in irradiated NOG mice in vivo.

AFT024 cell line in co-culture system using high pore density insert (HPDI) maintains hematopoietic stem/progenitor cells (HSCs/HPCs) as more primitive state through histone modification.

BACKGROUND It has been shown that the AFT024 stromal cell line sustains the engraftment capacity of human hematopoietic progenitor cells (HPCs) in vitro. However, the process by which AFT024 cell line maintains human HPCs is a more primitive state ex vivo remains unclear. METHODS Human umbilical cord blood (UCB)-derived fluorescent activated cell sorter (FACS)-purified CD34(+) CD38(-)hsc/HPCs were cultured with cytokines on hpdi (0.4 micron pore size) coated with irradiated AFT024 cells. The HSC/HPC and AFT024 cells contacted each other through 0.4 micron pores on HPDI membranes; the irradiated AFT024 cells could not migrate through the HPDI to contaminate the HSC/HPC. The frequency of CD34(+)Lin(-) cells was determined as HSCs/HPCs using flow cytometry. To evaluate their engraftment potential in vivo, the co-cultured cells were assayed as Long Term Culture-Initiating Cells (LTC-IC). To understand the process whereby AFT024 cells govern enhanced engraftment, we employed Western blot analysis for histone modifications. RESULTS There was a 30-fold increase in frequency of CD34(+)Lin(-) cells in co-cultures on HPDI coated on the outer bottom surface with irradiated AFT024 cells and cytokines in contrast to 6-fold among controls. Total colonies from LTC-IC increased approximately 1.5-fold among cells cultured with AFT024, compared with controls. More importantly, cells co-cultured with AFT024 showed a more primitive state with over-methylated h3k4 (Me-H3K4), under-methylated h3k9 (Di-Me-H3K4), and over-acetylated h4 (Ac-H4) compared with controls. CONCLUSION Our results suggested that co-culture of the AFT024 cell line with HPDI maintained hematopoietic progenitors as a more primitive state through histone modification.

Laparoscopic right posterior sectionectomy versus laparoscopic right hemihepatectomy for hepatocellular carcinoma in posterior segments: Propensity Score Matching Analysis

Background and Aims: This study was designed to analyze the feasibility of laparoscopic right posterior sectionectomy compared to laparoscopic right hemihepatectomy in patients with hepatocellular carcinoma located in the posterior segments. Material and Methods: The study included patients who underwent either laparoscopic right posterior sectionectomy or laparoscopic right hemihepatectomy for hepatocellular carcinoma located in segment 6 or 7 from January 2009 to December 2016 at Samsung Medical Center. After 1:1 propensity score matching, patient baseline characteristics and operative and postoperative outcomes were compared between the two groups. Disease-free survival and overall survival were compared using Kaplan–Meier log-rank test. Results: Among 61 patients with laparoscopic right posterior sectionectomy and 37 patients with laparoscopic right hemihepatectomy, 30 patients from each group were analyzed after propensity score matching. After matching, baseline characteristics of the two groups were similar including tumor size (3.4 ± 1.2 cm in laparoscopic right posterior sectionectomy vs 3.7 ± 2.1 cm in laparoscopic right hemihepatectomy, P = 0.483); differences were significant before matching (3.1 ± 1.3 cm in laparoscopic right posterior sectionectomy vs 4.3 ± 2.7 cm in laparoscopic right hemihepatectomy, P = 0.035). No significant differences were observed in operative and postoperative data except for free margin size (1.04 ± 0.71 cm in laparoscopic right posterior sectionectomy vs 2.95 ± 1.75 cm in laparoscopic right hemihepatectomy, P < 0.001). Disease-free survival (5-year survival: 38.0% in laparoscopic right posterior sectionectomy vs 47.0% in laparoscopic right hemihepatectomy, P = 0.510) and overall survival (5-year survival: 92.7% in laparoscopic right posterior sectionectomy vs 89.6% in laparoscopic right hemihepatectomy, P = 0.593) did not differ between the groups based on Kaplan–Meier log-rank test. Conclusion: For hepatocellular carcinoma in the posterior segments, laparoscopic right posterior sectionectomy was feasible compared to laparoscopic right hemihepatectomy when performed by experienced laparoscopic surgeons.

Jejunal artery can be a useful option for arterial reconstruction in living donor liver transplantation when the suitable arterial inflow is absent.

Successful arterial reconstruction is essential for liver transplantation. In the case of inadequate arterial inflow, an arterial conduit from the aorta using artery graft or re-establishment of arterial flow through other arteries such as the splenic artery, gastroepiploic, or sigmoid artery is considered. Herein we report our experience of 27 cases of hepatic artery reconstruction using alternative methods. The most common cause of hepatic artery reconstruction requiring alternative methods was intimal dissection for which we usually used the gastroepiploic artery. Many patients had a previous operation or transarterial chemoembolization history. Among these cases, hepatic artery reconstruction using the jejunal artery was performed for 2 cases of living donor liver transplantation due to the absence of suitable alternatives. These patients have been followed up with patent hepatic arterial flow until now. Thus, the jejunal artery can be a useful option for arterial reconstruction in living donor liver transplantation when suitable arterial inflow is absent.