Kyo Won Lee

Xenotransplantation of layer-by-layer encapsulated non-human primate islets with a specified immunosuppressive drug protocol

ABSTRACT Islet transplantation is as effective as but also less immunogenic than pancreas transplantation for the treatment of type 1 diabetes mellitus. However, as the complete elimination of immunogenicity still remains a major obstacle in islet transplantation, layer‐by‐layer encapsulation (LbL) of pancreatic islets using biocompatible polymers offers a rational approach to reducing host immune response towards transplanted islets. We investigated the effect of LbL of non‐human primate (NHP) islets on reducing immunogenicity as a preclinical model since NHPs have close phylogenetic and immunological relationship with humans. LbL with three‐layers of polyethylene glycol (PEG) molecules (SH‐6‐arm‐PEG‐NHS, 6‐arm‐PEG‐catechol and linear PEG‐SH) showed a uniform nano‐shielding on islets without the loss of viability or function of islets. An immunosuppressive drug protocol was also combined to improve the survival rate of the transplanted islets in vivo. A xenorecipient (C57BL/6 mice) of LbL islet transplanted along with our immunosuppressive drug protocol showed 100% survival rate for 150 days after transplantation. On the other hand, naked islet recipients showed poor survival time of 5.5 ± 1.4 days without drugs and 77.5 ± 42 days with the drug protocol. Immunohistochemistry of the transplanted grafts and serum cytokine concentration demonstrated less immunogenicity in the LbL islet transplanted recipients compared with the naked islet ones.

Surgical Techniques for Totally Laparoscopic Caudate Lobectomy.

OBJECTIVESnThe purpose of this study is to identify the safety and feasibility of laparoscopic caudate lobectomy.nnnBACKGROUNDnCaudate lobectomy has been considered as technically difficult because of the deep location of the caudate lobe and its proximity to great vessels. Due to the technical difficulty, laparoscopic caudate lobectomy was not feasible in patients with malignancy in the caudate lobe.nnnMETHODSnSix consecutive patients with caudate hepatic malignancy received laparoscopic caudate lobectomy at Samsung Medical Center from September 2007 to May 2014. Demographic data, intraoperative parameters, and postoperative outcomes were assessed.nnnRESULTSnAll procedures for these 6 patients with caudate malignancy were completed with totally laparoscopic technique. Only 1 patient who had hepatocellular carcinoma in the Spiegel lobe underwent partial caudate lobectomy, and others underwent complete caudate lobectomy. The mean tumor size was 2.65u2009cm (range 0.9-5.1u2009cm). The mean operative time was 382 minutes (range 168-615 minutes) and none required transfusion. The mean duration of hospital stay was 8 days (range 6-13 days). There was no perioperative complication and patient mortality in this series. The resected margins of the specimens were tumor free (R0 resections, range 0.1-1.2u2009cm). The mean follow-up period was 56 months (range 12.9-93.7 months). No patient died during the follow-up period.nnnCONCLUSIONSnOur experience demonstrated that laparoscopic caudate lobectomy is safe and feasible in selected patients with malignancy in the caudate lobe.

Superior mesenteric vein thrombosis accompanied with severe appendicitis.

Superior mesenteric vein (SMV) thrombosis caused by acute appendicitis is a very rare entity nowadays. We report a successfully treated case of a 21-year-old man with SMV thrombosis associated with severe acute appendicitis. Intravenous heparin was administered, and it was later substituted with warfarin. Systemic antibiotic therapy was continued for 1 week, and it was substituted with oral antibiotics, which were administered for 3 weeks. On the 45th postoperative day, follow-up computed tomography scan demonstrated dissolution of SMV thrombosis. Anticoagulation therapy was maintained for 3 months. He was discharged without any complications. SMV thrombosis can be treated successfully with emergency appendectomy, broad-spectrum antibiotics, and anticoagulation therapy.

Comparative characterization of mesenchymal stromal cells from multiple abdominal adipose tissues and enrichment of angiogenic ability via CD146 molecule

BACKGROUNDnThere are various types of adipose tissue in the human body, and their morphology is known to be closely related to cell function and metabolism. However, the functional differences among the mesenchymal stromal cells (MSCs) of different abdominal adipose tissues have not been clearly elucidated.nnnMETHODSnMSCs were isolated from different abdominal adipose tissues according to their regional distribution and included superficial subcutaneous, deep subcutaneous, omentum, mesentery and retroperitoneal MSCs. The immunophenotype, proliferative ability and angiogenic function of these MSCs were compared based on flow cytometry analysis, CCK-8 proliferation, in vitro differentiation, tubule formation and in vivo plug assay.nnnRESULTSnThe plastic adherence, cell morphology and general immunophenotype are similar among the MSCs. However, subcutaneous adipose tissue-derived MSCs have a faster growth rate and a higher level of CD146 expression than the other MSCs. Moreover, according to the fluorescence-activated cell sorting (FACS) enrichment procedure, the expression level of CD146 is positively related to the growth rate and angiogenic capability of MSCs.nnnDISCUSSIONnMSCs in adipose tissue showed slightly different characteristics depending on their location of origin, and they possessed different angiogenic abilities that were mediated by the expression of CD146. This study provides evidence that subcutaneous adipose tissue is the most appropriate source of MSCs for therapeutic cell transplantation in vascular disease.

Measurement of carotid artery stenosis: correlation analysis between B-mode ultrasonography and contrast arteriography.

Purpose To evaluate the efficacy of B-mode ultrasonography (US) in measurement of carotid stenosis% (CS%). Methods One hundred and thirth-three carotid arteries in 96 patients who underwent both carotid US and carotid arteriography (CA) were included in this retrospective study. To measure CS% on US, a cross sectional view of the most stenotic segment of the internal carotid artery was captured and residual diameter and original diameter of that segment were measured with electronic caliper on the same plane and in the same direction. To measure CS% on an angiogram, we used European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. Pearsons correlation analysis and linear regression analysis were used to determine the correlation between CS% on an US and angiogram. Results Pearsons correlation coefficient (R) between CS% measured in US and CA were 0.853 (ECST method, P < 0.001) and 0.828 (NASCET method, P < 0.001). Accuracies of B-mode US were 93.2%, 88.0%, and 81.2% for estimating CS% by ECST method and 86.5%, 82.7%, and 82% for estimating CS% by NASCET method. Conclusion CS% measured in B-mode US was simpler and showed a strong positive correlation with that measured on an arteriogram either ECST or NASCET method.

Outcome of living donor liver transplantation using right liver allografts with multiple arterial supply

A right liver graft with multiple hepatic artery (HA) stumps can be found in approximately 5% of living donor liver transplantation (LDLT) using a right lobe graft. From January 2000 to June 2014, 1149 patients underwent LDLT procedures. Thirty patients with LDLT using a right lobe graft with multiple HA stumps and 149 patients with LDLT using a right lobe graft with a single HA stump were enrolled. These patients were divided into 3 groups: single HA (group 1, nu2009=u2009149), multiple HAs with total reconstruction (group 2, nu2009=u200919), and multiple HAs with selective partial reconstruction (group 3, nu2009=u200911). Selective partial reconstruction was performed only when pulsatile back‐bleeding was confirmed after larger HA reconstruction and sufficient intrahepatic arterial flow was confirmed by Doppler ultrasound (DUS). In group 2, the donor HAs were smaller (Pu2009<u2009.001), and HA reconstruction took longer (Pu2009<u2009.001). However, there was no significant difference among the groups regarding the arterial complication rate, biliary complication rate, and patient and graft survival. In conclusion, selective partial reconstruction of HA stumps for LDLT using a right lobe graft was feasible when intrahepatic arterial communication was confirmed by pulsatile back‐bleeding from the smaller artery and DUS. Liver Transplantation 22 1649–1655 2016 AASLD.

Enhanced effect of human mesenchymal stem cells expressing human TNF-αR-Fc and HO-1 gene on porcine islet xenotransplantation in humanized mice

Porcine islet xenotransplantation is considered an attractive alternative treatment for type 1 diabetes mellitus. However, it is largely limited because of initial rejection due to Instant Blood‐Mediated Inflammatory Reaction (IBMIR), oxidative stress, and inflammatory responses. Recently, soluble tumor necrosis factor‐ɑ receptor type I (sTNF‐αR) and heme oxygenase (HO)‐1 genes (HO‐1/sTNF‐αR) have been shown to improve the viability and functionality of porcine islets after transplantation.

Clinical benefit and residual kidney function of en bloc nephrectomy for perirenal retroperitoneal sarcoma

The purpose of this study was to evaluate the efficacy of en bloc nephrectomy for perirenal retroperitoneal sarcoma (RPS) with respect to postoperative kidney function and oncological benefits.

Hand-Assisted Laparoscopic Nephrectomy and Auto-Transplantation for a Hilar Renal Artery Aneurysm: A Case Report

A 52-year-old man was admitted with an incidentally detected right renal artery aneurysm (RAA). Computed tomographic angiography with three-dimensional reconstruction revealed that the aneurysm was 2.2 cm in diameter and located at the renal hilum. We performed hand-assisted laparoscopic nephrectomy with ex vivo repair of the RAA and auto-transplantation with minimal elongation of Gibson incision. The operation and postoperative course were uneventful. At last follow-up, the patient was alive with a well-functioning auto-transplant. Hand-assisted laparoscopic nephrectomy and auto-transplantation is a useful treatment option for hilar RAA.

En bloc transplantation of horseshoe kidney in Korea

Transplantation of the horseshoe kidney can be performed en bloc or split into 2 grafts according to the vascular anomaly and the existence of the urinary collecting system in isthmus. From 2011 to 2014, there were 3 horseshoe kidney transplantations in Korea and transplantations were performed at 2 different centers. The transplantations were carried out successfully for all recipients without complications. All recipients have shown good graft kidney function after transplantation. No severe complication was revealed during follow-up period. We described the surgical technique used in the en bloc method to overcome various vascular anomalies and difficulties in choosing cannulation site and postoperative complications. En bloc transplantation of a horseshoe kidney is a useful strategy for patients with end-stage renal disease, and can provide favorable outcomes compared to the transplantation of a normal kidney.