Yong Chan Shin - Academia.edu (original) (raw)

Papers by Yong Chan Shin

Research paper thumbnail of Effect of Polyglycolic Acid Mesh for Prevention of Pancreatic Fistula Following Distal Pancreatectomy

JAMA Surgery, Feb 1, 2017

The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% t... more The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% to 64%. To prevent POPF, polyglycolic acid (PGA) mesh was introduced, but its effect has been evaluated only in small numbers of patients and retrospective studies. OBJECTIVE To evaluate the efficacy of PGA mesh in preventing POPF after distal pancreatectomy. DESIGN, SETTING, AND PARTICIPANTS Prospective randomized clinical, single-blind (participant), parallel-group trial at 5 centers between November 2011 and April 2014. The pancreatic parenchyma was divided using a stapling device; no patient was given prophylactic octreotide. Perioperative and clinical outcomes were compared including POPF, which was graded according to the criteria of the International Study Group For Pancreatic Fistulas. A total of 97 patients aged 20 to 85 years with curable benign, premalignant, or malignant disease of the pancreatic body or tail were enrolled (44 in the PGA group and 53 in the control group). INTERVENTIONS Patients in the PGA group underwent transection of the pancreas and application of fibrin glue followed by wrapping the PGA mesh around the remnant pancreatic stump. MAIN OUTCOMES AND MEASURES The primary end point of this study was the development of a clinically relevant POPF (grade B or C by the International Study Group grading system). The secondary end point was the evaluation of risk factors for POPF. RESULTS The study therefore evaluated a total of 97 patients, 44 in the PGA group and 53 in the control group. Thirty-nine patients were women and 58 patients were men. There were no differences in mean (SD) age (59.9 [12.0] years vs 54.5 [14.1] years, P = .05), male to female ratio (1.0:1.3 vs 1.0:1.7, P = .59), malignancy (40.9% vs 32.1%, P = .37), mean (SD) pancreatic duct diameter (1.92 [0.75] mm vs 1.94 [0.95] mm, P = .47), soft pancreatic texture (90.9% vs 83.0%, P = .17), and mean (SD) thickness of the transection margin (16.9 [5.4] mm vs 16.4 [4.9] mm, P = .63) between the PGA and control groups. The rate of clinically relevant POPF (grade B or C) was significantly lower in the PGA group than in the control group (11.4% vs 28.3%, P = .04). CONCLUSIONS AND RELEVANCE Wrapping of the cut surface of the pancreas with PGA mesh is associated with a significantly reduced rate of clinically relevant POPF. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01550406.

Research paper thumbnail of Effect of Polyglycolic Acid Mesh for Prevention of Pancreatic Fistula Following Distal Pancreatectomy: A Randomized Clinical Trial

JAMA surgery, Feb 26, 2016

The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% t... more The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% to 64%. To prevent POPF, polyglycolic acid (PGA) mesh was introduced, but its effect has been evaluated only in small numbers of patients and retrospective studies. To evaluate the efficacy of PGA mesh in preventing POPF after distal pancreatectomy. Prospective randomized clinical, single-blind (participant), parallel-group trial at 5 centers between November 2011 and April 2014. The pancreatic parenchyma was divided using a stapling device; no patient was given prophylactic octreotide. Perioperative and clinical outcomes were compared including POPF, which was graded according to the criteria of the International Study Group For Pancreatic Fistulas. A total of 97 patients aged 20 to 85 years with curable benign, premalignant, or malignant disease of the pancreatic body or tail were enrolled (44 in the PGA group and 53 in the control group). Patients in the PGA group underwent transection...

Research paper thumbnail of Clinicopathologic characters and outcomes of pancreatic neuroendocrine tumors: comparison of functioning versus non-functioning tumors

Korean Journal of Clinical Oncology, 2014

Research paper thumbnail of Comparison of laparoscopic versus open left-sided hepatectomy for intrahepatic duct stones

Surgical endoscopy, Jan 11, 2015

Laparoscopic hepatectomy for intrahepatic duct (IHD) stones is limited by technical difficulties ... more Laparoscopic hepatectomy for intrahepatic duct (IHD) stones is limited by technical difficulties caused by adhesion to adjacent tissue or distorted anatomy resulting from recurrent inflammation. This study compared perioperative and clinical outcomes in patients undergoing laparoscopic and open hepatectomy for left IHD stones. From January 2002 to December 2013, 40 patients underwent laparoscopic left-sided hepatectomy [left hemihepatectomy (n = 7) or left lateral sectionectomy (n = 33)] and 155 underwent open left-sided hepatectomy, including 54 patients without combined operations and previous operation histories [left hemihepatectomy (n = 24) or left lateral sectionectomy (n = 30)]. Their perioperative and clinical outcomes were compared, including stone clearance rates, stone recurrence rates, and median follow-up duration. There was no difference in age (56.8 ± 8.2 vs. 55.6 ± 9.6 years, p = 0.531), sex (1.0:4.0 vs. 1.0:1.8 male:female, p = 0.108), or BMI (22.8 ± 2.8 vs. 22.9 ± ...

Research paper thumbnail of Detection of bladder cancer related DNA biomarkers using silicon microring resonators

2012 Photonics Global Conference, Dec 1, 2012

ABSTRACT DNA biomarkers have been demonstrated as an important diagnostic factor for detection of... more ABSTRACT DNA biomarkers have been demonstrated as an important diagnostic factor for detection of early stage in human cancers. To date, many genetic alterations of biomarkers have been identified in urothelial cell carcinoma of the bladder. Among the several alterations, the mutations of FGFR 3 (fibroblast growth factor receptor 3) and HRAS (Harvey RAS) are associated with early stage of bladder cancer. The genetic events of the genes are mutually exclusive in urothelial cells. We have recently reported highly sensitive silicon based microring resonators, which was applied to bio-molecules (protein, nucleic acid and so on) sensing by monitoring a shift in the resonant wavelength. Silicon microring resonators are essentially refractive index-based optical sensors that provide highly sensitive, label-free, real-time, and multiplexed detection of bio-molecules near the sensor surface. Furthermore, the devices are fabricated by the standard CMOS technology, which ensures low-cost and scale-up capability of the sensor fabrication. In this study, we present a nucleic acid sensor based on silicon microring resonators to detect DNA biomarkers (FGFR3 and HRAS), which used as targets of bladder cancer detection. DNA probes complementary to the part of the target oligonucleotides of FGFR3 (116bp) and HRAS (160bp) are immobilized on silicon surface with amine modification method. We show the wild type probes of FGFR3, and HRAS genes can completely capture the wild type targets compared to non-specific target probe. Furthermore, the mutant types of FGFR3 (R249C) and HRAS (G13R) genes can be strongly detected by using silicon microring resonators. Therefore, our sensor can be used to detect the DNA biomarker for early detection of bladder cancers.

Research paper thumbnail of Improvement of clinical outcomes in the patients with gallbladder cancer: lessons from periodic comparison in a tertiary referral center

Journal of hepato-biliary-pancreatic sciences, Jan 3, 2016

Current guidelines for gallbladder cancer (GBC) contain controversies and some reported no surviv... more Current guidelines for gallbladder cancer (GBC) contain controversies and some reported no survival improvement in GBC during 20 years. This study was designed to explore the chronologic change of survival outcomes in GBC and prognostic factors. Clinicopathologic features, survival outcomes were analyzed in 692 consecutive GBC patients who underwent surgery between 1987 and 2014, including 255 treated in Period (P) 1 (1987-2000) and 437 in P2 (2001-2014). The mean age was 63.3 years. Curative resection rate was 59.2% and 5-year survival rate (5-YSR) after curative resection was 67.1%. Comparisons between P1 and P2 showed that mean age, asymptomatic presentation, extended cholecystectomy, curative resection, adjuvant chemotherapy, and tumor ≤ T2 were significantly higher during P2. The overall 5-YSR after curative surgery was significantly lower in P1. In patients who underwent curative resection, poor prognostic factors included symptomatic presentation, CA 19-9 > 37 IU/ml, poor ...

Research paper thumbnail of Metabolic effect of pancreatoduodenectomy: resolution of diabetes mellitus after surgery

Pancreatology, 2016

It is considered natural that glucose tolerance worsens after pancreatectomy. However, diabetes m... more It is considered natural that glucose tolerance worsens after pancreatectomy. However, diabetes mellitus (DM) resolves after metabolic bypass surgery and anatomic changes after PD resemble those after metabolic surgery. This study assessed the incidence of DM resolution after pancreatectomy and differences in metabolic parameters following pancreatoduodenectomy (PD) and distal pancreatectomy (DP). Between 2007 and 2013, 218 consecutive patients with pancreatic diseases underwent PD (n = 112) or DP (n = 106) at Seoul National University Hospital. Factors associated with changes in glucose homeostasis were evaluated by assaying serum glucose concentrations in prospectively collected samples. Of the 218 patients, 88 (40.4%) had preoperative DM, with 27 (30.7%) of the latter showing postoperative resolution of DM, a rate significantly higher in patients who had undergone PD than DP (40.4% vs. 12.9%, p = 0.008). Fasting blood glucose (p = 0.001), PP2 (p < 0.001), and HOMA-IR (p = 0.005) significantly decreased after PD but not after DP. Multivariate analysis revealed that PD was independently associated with DM resolution (odds ratio 7.790, p = 0.003). PD was associated with a significantly higher DM resolution rate than DP among the 37 pancreatic cancer patients with preoperative DM (34.6% vs. 0%, p = 0.036). DM resolution rates were similar in pancreatic cancer and other pancreatic diseases (p = 0.419). More than 40% of patients with preoperative DM show resolution after PD. Decreased insulin resistance and suspected enhanced glucose stimulated insulin secretion decreasing PP2 seem to contribute improved glucose homeostasis after PD. BMI was unrelated to DM resolution, indicating that PD-associated physio-anatomical changes may help resolve DM independent of weight.

Research paper thumbnail of Care Status of the ALS Patients With Long-Term Use of Tracheostomy Tube

Annals of rehabilitation medicine, 2015

To evaluate the care status of the amyotrophic lateral sclerosis (ALS) patients with long-term us... more To evaluate the care status of the amyotrophic lateral sclerosis (ALS) patients with long-term use of tracheostomy tube by caregivers of ALS patients. A survey was conducted in the form of questionnaires to ALS patients and their caregivers. All measurements were performed by two visiting nurses. For statistical analysis, SPSS ver. 22.0 and Mann-Whitney U test on non-normal distribution were used. In total, 19 patients (15 males and 4 females) and their caregivers participated in the survey. In the case of patients, the average duration of care was 5.9±3.7 years, and the mean periods of illness and tracheostomy were 5.3±3.2 years and 3.0±2.6 years, respectively. Replacement intervals were 14 days in 11 patients, 7 days in 4 patients, 28 days in 2 patients, and 21 days in 1 patient. One patient was unable to provide an accurate replacement interval. Eighteen (99%) caregivers had experience of adding volume to a cuff without pressure measure in the following instances: due to patients...

Research paper thumbnail of The clinical usefulness of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in follow-up of curatively resected pancreatic cancer patients

HPB : the official journal of the International Hepato Pancreato Biliary Association, 2016

Computed tomography and serum tumor markers have limited value in detecting recurrence after cura... more Computed tomography and serum tumor markers have limited value in detecting recurrence after curative surgery of pancreatic cancer. This study evaluated the clinical utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in diagnosing recurrence. One hundred ten patients underwent curative resection of pancreatic cancer were enrolled. The diagnostic value of abdominal computed tomography (CT), PET-CT and serum carbohydrate antigen (CA) 19-9 concentration were compared. The prognostic value of SUVmax on PET-CT was evaluated. PET-CT showed relatively higher sensitivity (84.5% vs. 75.0%) and accuracy (84.5% vs. 74.5%) than CT, whereas PET-CT plus CT showed greater sensitivity (97.6%) and accuracy (90.0%) than either alone. In detecting distant recurrences, PET-CT showed higher sensitivity (83.1% vs. 67.7%) than CT. Nineteen patients showed recurrences only on PET-CT, with eleven having invisible or suspected benign lesions on CT, and eight had recur...

Research paper thumbnail of Multiphoton imaging of myogenic differentiation in gelatin-based hydrogels as tissue engineering scaffolds

Biomaterials research, 2016

Hydrogels can serve as three-dimensional (3D) scaffolds for cell culture and be readily injected ... more Hydrogels can serve as three-dimensional (3D) scaffolds for cell culture and be readily injected into the body. Recent advances in the image technology for 3D scaffolds like hydrogels have attracted considerable attention to overcome the drawbacks of ordinary imaging technologies such as optical and fluorescence microscopy. Multiphoton microscopy (MPM) is an effective method based on the excitation of two-photons. In the present study, C2C12 myoblasts differentiated in 3D gelatin hydroxyphenylpropionic acid (GHPA) hydrogels were imaged by using a custom-built multiphoton excitation fluorescence microscopy to compare the difference in the imaging capacity between conventional microscopy and MPM. The physicochemical properties of GHPA hydrogels were characterized by using scanning electron microscopy and Fourier-transform infrared spectroscopy. In addition, the cell viability and proliferation of C2C12 myoblasts cultured in the GHPA hydrogels were analyzed by using Live/Dead Cell and ...

Research paper thumbnail of Enhanced Osteogenesis by Reduced Graphene Oxide/Hydroxyapatite Nanocomposites

Scientific reports, 2015

Recently, graphene-based nanomaterials, in the form of two dimensional substrates or three dimens... more Recently, graphene-based nanomaterials, in the form of two dimensional substrates or three dimensional foams, have attracted considerable attention as bioactive scaffolds to promote the differentiation of various stem cells towards specific lineages. On the other hand, the potential advantages of using graphene-based hybrid composites directly as factors inducing cellular differentiation as well as tissue regeneration are unclear. This study examined whether nanocomposites of reduced graphene oxide (rGO) and hydroxyapatite (HAp) (rGO/HAp NCs) could enhance the osteogenesis of MC3T3-E1 preosteoblasts and promote new bone formation. When combined with HAp, rGO synergistically promoted the spontaneous osteodifferentiation of MC3T3-E1 cells without hindering their proliferation. This enhanced osteogenesis was corroborated from determination of alkaline phosphatase activity as early stage markers of osteodifferentiation and mineralization of calcium and phosphate as late stage markers. I...

Research paper thumbnail of Use of TachoSil(®) patches to prevent pancreatic leaks after distal pancreatectomy: a prospective, multicenter, randomized controlled study

Journal of hepato-biliary-pancreatic sciences, Jan 17, 2015

We performed a prospective, multicenter, randomized controlled study to investigate the clinical ... more We performed a prospective, multicenter, randomized controlled study to investigate the clinical outcomes, including POPF, after using the TachoSil(®) patch in distal pancreatectomy (NCT01550406). Between June 2012 and September 2014, 101 patients at 5 centers were randomized into Control (n = 53) and TachoSil (n = 48) groups. In all patients, the pancreas was resected using a stapler with Endo-GIA™ staples. The TachoSil patch was wrapped around the pancreatic stump only in the TachoSil group, not in Control group. The patient characteristics, including age and diagnosis, were comparable in both groups. The mean operation time (159.4 vs 172.3 min, P = 0.081) and postoperative hospital stay (10.0 vs 9.7 days, P = 0.279) were similar in the Control and TachoSil groups, respectively. The overall incidence of POPF was 62.4% (n = 63). The distribution of grades A, B, and C POPF was similar in the Control (14/14/1) and TachoSil (23/11/0) groups, as were the overall incidence (54.7% vs 70....

Research paper thumbnail of Chemical characteristics and enhanced hepatoprotective activities of Maillard-reaction products derived from milk protein-sugar system

Journal of dairy science, Jan 25, 2015

The objective of this study was to investigate the characteristics, antioxidative properties, and... more The objective of this study was to investigate the characteristics, antioxidative properties, and hepatoprotective effects of Maillard reaction products (MRP) from milk protein reacted with sugars. The MRP were obtained from milk protein, whey protein concentrates and sodium caseinate, using 2 types of sugars, lactose and glucose, by heating the mixture at 55°C for 7 d in a sodium phosphate buffer (pH 7.4). Changes in the chemical modification of the milk protein were monitored by measuring the protein-bound carbonyls and PAGE protein profiles. The results showed that the amount of protein-bound carbonyls increased after Maillard reaction (MR). In addition, sodium dodecyl sulfate-PAGE analysis indicated a formation of high-molecular weight complexes through MR. The modification sites induced by MR of milk protein were monitored by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of tryptic-digested gel spots of MRP. As a result, modification and ...

Research paper thumbnail of Stimulating effect of graphene oxide on myogenesis of C2C12 myoblasts on RGD peptide-decorated PLGA nanofiber matrices

Journal of biological engineering, 2015

In the field of biomedical engineering, many studies have focused on the possible applications of... more In the field of biomedical engineering, many studies have focused on the possible applications of graphene and related nanomaterials due to their potential for use as scaffolds, coating materials and delivery carriers. On the other hand, electrospun nanofiber matrices composed of diverse biocompatible polymers have attracted tremendous attention for tissue engineering and regenerative medicine. However, their combination is intriguing and still challenging. In the present study, we fabricated nanofiber matrices composed of M13 bacteriophage with RGD peptide displayed on its surface (RGD-M13 phage) and poly(lactic-co-glycolic acid, PLGA) and characterized their physicochemical properties. In addition, the effect of graphene oxide (GO) on the cellular behaviors of C2C12 myoblasts, which were cultured on PLGA decorated with RGD-M13 phage (RGD/PLGA) nanofiber matrices, was investigated. Our results revealed that the RGD/PLGA nanofiber matrices have suitable physicochemical properties as...

Research paper thumbnail of Anti-inflammatory effect of desoxo-narchinol-A isolated from Nardostachys jatamansi against lipopolysaccharide

International immunopharmacology, Jan 11, 2015

We previously reported that Nardostachys jatamansi (NJ) exhibits anti-inflammatory activity again... more We previously reported that Nardostachys jatamansi (NJ) exhibits anti-inflammatory activity against lipopolysaccharide (LPS). However, the active compound in NJ is unknown. Therefore, here, we examined the effects of desoxo-narchinol-A (DN) isolated from NJ against LPS-induced inflammation. To demonstrate the anti-inflammatory effect of DN against LPS, we used two models; murine endotoxin shock model for in vivo model, and peritoneal macrophage responses for in vitro. In endotoxin shock model, DN was administrated intraperitoneally 1h before LPS challenge, then we evaluated mice survival rates and organ damages. Pretreatment with DN (0.05mg/kg, 0.1mg/kg, or 0.5mg/kg) dramatically reduced mortality in a murine LPS-induced endotoxin shock model. Furthermore, DN inhibited tissue injury and production of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α), in the liver and lung. In in vitro macrophage model, we examined the inflammatory...

Research paper thumbnail of Effects of Surgical Methods and Tumor Location on Survival and Recurrence Patterns after Curative Resection in Patients with T2 Gallbladder Cancer

Gut and liver, Jan 9, 2015

Extended cholecystectomy is generally recommended for patients with T2 gallbladder cancer. Howeve... more Extended cholecystectomy is generally recommended for patients with T2 gallbladder cancer. However, few studies have assessed the extent of resection relative to T2 gallbladder tumor location. This study analyzed the effects of surgical methods and tumor location on survival outcomes and tumor recurrence in patients with T2 gallbladder cancer. Clinicopathological characteristics, extent of resection, survival rates, and recurrence patterns were retrospectively analyzed in 88 patients with pathologically confirmed T2 gallbladder cancer. The 5-year disease-free survival rate was 65.0%. Multivariate analysis showed that lymph node metastasis was the only independent risk factor for poor 5-year disease-free survival rate. Survival outcomes were not associated with tumor location. Survival tended to be better in patients who underwent extended cholecystectomy than in those who underwent simple cholecystectomy. Recurrence rate was not affected by surgical method or tumor location. Systemi...

Research paper thumbnail of Cell-adhesive RGD peptide-displaying M13 bacteriophage/PLGA nanofiber matrices for growth of fibroblasts

Biomaterials research, 2014

M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with ... more M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with a nanofiber-like shape. In the present study, we prepared hybrid nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and M13 bacteriophages which were genetically modified to display the RGD peptide on their surface (RGD-M13 phage). The surface morphology and chemical composition of hybrid nanofiber matrices were characterized by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. Immunofluorescence staining was conducted to investigate the existence of M13 bacteriophages in RGD-M13 phage/PLGA hybrid nanofibers. In addition, the attachment and proliferation of three different types of fibroblasts on RGD-M13 phage/PLGA nanofiber matrices were evaluated to explore how fibroblasts interact with these matrices. SEM images showed that RGD-M13 phage/PLGA hybrid matrices had the non-woven porous structure, quite similar to that of natural extracellular matric...

Research paper thumbnail of Efficacy of Systemic Postoperative Pulmonary Rehabilitation After Lung Resection Surgery

Annals of rehabilitation medicine, 2015

To investigate the efficacy of systemic pulmonary rehabilitation (PR) after lung resection in pat... more To investigate the efficacy of systemic pulmonary rehabilitation (PR) after lung resection in patients with lung cancer. Forty-one patients undergoing lung resection were enrolled and classified into the experimental (n=31) and control groups (n=10). The experimental group underwent post-operative systemic PR which was conducted 30 min/day on every hospitalization day by an expert physical therapist. The control group received the same education about the PR exercises and were encouraged to self-exercise without supervision of the physical therapist. The PR group was taught a self-PR program and feedback was provided regularly until 6 months after surgery. We conducted pulmonary function testing (PFT) and used a visual analog scale (VAS) to evaluate pain, and the modified Borg Dyspnea Scale (mBS) to measure perceived respiratory exertion shortly before and 2 weeks, 1, 3, and 6 months after surgery. A significant improvement on the VAS was observed in patients who received systemic P...

Research paper thumbnail of In vivo RNAi screen identifies NLK as a negative regulator of mesenchymal activity in Glioblastoma

Oncotarget, Jan 19, 2015

Glioblastoma (GBM) is the most lethal brain cancer with profound genomic alterations. While the b... more Glioblastoma (GBM) is the most lethal brain cancer with profound genomic alterations. While the bona fide tumor suppressor genes such as PTEN, NF1, and TP53 have high frequency of inactivating mutations, there may be the genes with GBM-suppressive roles for which genomic mutation is not a primary cause for inactivation. To identify such genes, we employed in vivo RNAi screening approach using the patient-derived GBM xenograft models. We found that Nemo-Like Kinase (NLK) negatively regulates mesenchymal activities, a characteristic of aggressive GBM, in part via inhibition of WNT/β-catenin signaling. Consistent with this, we found that NLK expression is especially low in a subset of GBMs that harbors high WNT/mesenchymal activities. Restoration of NLK inhibited WNT and mesenchymal activities, decreased clonogenic growth and survival, and impeded tumor growth in vivo. These data unravel a tumor suppressive role of NLK and support the feasibility of combining oncogenomics with in vivo ...

Research paper thumbnail of Pi30 DNA Probe May Be Useful for the Identification of Prevotella intermedia at the Species or Strain Level

Microbiology and Immunology, 2004

Research paper thumbnail of Effect of Polyglycolic Acid Mesh for Prevention of Pancreatic Fistula Following Distal Pancreatectomy

JAMA Surgery, Feb 1, 2017

The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% t... more The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% to 64%. To prevent POPF, polyglycolic acid (PGA) mesh was introduced, but its effect has been evaluated only in small numbers of patients and retrospective studies. OBJECTIVE To evaluate the efficacy of PGA mesh in preventing POPF after distal pancreatectomy. DESIGN, SETTING, AND PARTICIPANTS Prospective randomized clinical, single-blind (participant), parallel-group trial at 5 centers between November 2011 and April 2014. The pancreatic parenchyma was divided using a stapling device; no patient was given prophylactic octreotide. Perioperative and clinical outcomes were compared including POPF, which was graded according to the criteria of the International Study Group For Pancreatic Fistulas. A total of 97 patients aged 20 to 85 years with curable benign, premalignant, or malignant disease of the pancreatic body or tail were enrolled (44 in the PGA group and 53 in the control group). INTERVENTIONS Patients in the PGA group underwent transection of the pancreas and application of fibrin glue followed by wrapping the PGA mesh around the remnant pancreatic stump. MAIN OUTCOMES AND MEASURES The primary end point of this study was the development of a clinically relevant POPF (grade B or C by the International Study Group grading system). The secondary end point was the evaluation of risk factors for POPF. RESULTS The study therefore evaluated a total of 97 patients, 44 in the PGA group and 53 in the control group. Thirty-nine patients were women and 58 patients were men. There were no differences in mean (SD) age (59.9 [12.0] years vs 54.5 [14.1] years, P = .05), male to female ratio (1.0:1.3 vs 1.0:1.7, P = .59), malignancy (40.9% vs 32.1%, P = .37), mean (SD) pancreatic duct diameter (1.92 [0.75] mm vs 1.94 [0.95] mm, P = .47), soft pancreatic texture (90.9% vs 83.0%, P = .17), and mean (SD) thickness of the transection margin (16.9 [5.4] mm vs 16.4 [4.9] mm, P = .63) between the PGA and control groups. The rate of clinically relevant POPF (grade B or C) was significantly lower in the PGA group than in the control group (11.4% vs 28.3%, P = .04). CONCLUSIONS AND RELEVANCE Wrapping of the cut surface of the pancreas with PGA mesh is associated with a significantly reduced rate of clinically relevant POPF. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01550406.

Research paper thumbnail of Effect of Polyglycolic Acid Mesh for Prevention of Pancreatic Fistula Following Distal Pancreatectomy: A Randomized Clinical Trial

JAMA surgery, Feb 26, 2016

The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% t... more The rate of postoperative pancreatic fistula (POPF) after distal pancreatectomy ranges from 13% to 64%. To prevent POPF, polyglycolic acid (PGA) mesh was introduced, but its effect has been evaluated only in small numbers of patients and retrospective studies. To evaluate the efficacy of PGA mesh in preventing POPF after distal pancreatectomy. Prospective randomized clinical, single-blind (participant), parallel-group trial at 5 centers between November 2011 and April 2014. The pancreatic parenchyma was divided using a stapling device; no patient was given prophylactic octreotide. Perioperative and clinical outcomes were compared including POPF, which was graded according to the criteria of the International Study Group For Pancreatic Fistulas. A total of 97 patients aged 20 to 85 years with curable benign, premalignant, or malignant disease of the pancreatic body or tail were enrolled (44 in the PGA group and 53 in the control group). Patients in the PGA group underwent transection...

Research paper thumbnail of Clinicopathologic characters and outcomes of pancreatic neuroendocrine tumors: comparison of functioning versus non-functioning tumors

Korean Journal of Clinical Oncology, 2014

Research paper thumbnail of Comparison of laparoscopic versus open left-sided hepatectomy for intrahepatic duct stones

Surgical endoscopy, Jan 11, 2015

Laparoscopic hepatectomy for intrahepatic duct (IHD) stones is limited by technical difficulties ... more Laparoscopic hepatectomy for intrahepatic duct (IHD) stones is limited by technical difficulties caused by adhesion to adjacent tissue or distorted anatomy resulting from recurrent inflammation. This study compared perioperative and clinical outcomes in patients undergoing laparoscopic and open hepatectomy for left IHD stones. From January 2002 to December 2013, 40 patients underwent laparoscopic left-sided hepatectomy [left hemihepatectomy (n = 7) or left lateral sectionectomy (n = 33)] and 155 underwent open left-sided hepatectomy, including 54 patients without combined operations and previous operation histories [left hemihepatectomy (n = 24) or left lateral sectionectomy (n = 30)]. Their perioperative and clinical outcomes were compared, including stone clearance rates, stone recurrence rates, and median follow-up duration. There was no difference in age (56.8 ± 8.2 vs. 55.6 ± 9.6 years, p = 0.531), sex (1.0:4.0 vs. 1.0:1.8 male:female, p = 0.108), or BMI (22.8 ± 2.8 vs. 22.9 ± ...

Research paper thumbnail of Detection of bladder cancer related DNA biomarkers using silicon microring resonators

2012 Photonics Global Conference, Dec 1, 2012

ABSTRACT DNA biomarkers have been demonstrated as an important diagnostic factor for detection of... more ABSTRACT DNA biomarkers have been demonstrated as an important diagnostic factor for detection of early stage in human cancers. To date, many genetic alterations of biomarkers have been identified in urothelial cell carcinoma of the bladder. Among the several alterations, the mutations of FGFR 3 (fibroblast growth factor receptor 3) and HRAS (Harvey RAS) are associated with early stage of bladder cancer. The genetic events of the genes are mutually exclusive in urothelial cells. We have recently reported highly sensitive silicon based microring resonators, which was applied to bio-molecules (protein, nucleic acid and so on) sensing by monitoring a shift in the resonant wavelength. Silicon microring resonators are essentially refractive index-based optical sensors that provide highly sensitive, label-free, real-time, and multiplexed detection of bio-molecules near the sensor surface. Furthermore, the devices are fabricated by the standard CMOS technology, which ensures low-cost and scale-up capability of the sensor fabrication. In this study, we present a nucleic acid sensor based on silicon microring resonators to detect DNA biomarkers (FGFR3 and HRAS), which used as targets of bladder cancer detection. DNA probes complementary to the part of the target oligonucleotides of FGFR3 (116bp) and HRAS (160bp) are immobilized on silicon surface with amine modification method. We show the wild type probes of FGFR3, and HRAS genes can completely capture the wild type targets compared to non-specific target probe. Furthermore, the mutant types of FGFR3 (R249C) and HRAS (G13R) genes can be strongly detected by using silicon microring resonators. Therefore, our sensor can be used to detect the DNA biomarker for early detection of bladder cancers.

Research paper thumbnail of Improvement of clinical outcomes in the patients with gallbladder cancer: lessons from periodic comparison in a tertiary referral center

Journal of hepato-biliary-pancreatic sciences, Jan 3, 2016

Current guidelines for gallbladder cancer (GBC) contain controversies and some reported no surviv... more Current guidelines for gallbladder cancer (GBC) contain controversies and some reported no survival improvement in GBC during 20 years. This study was designed to explore the chronologic change of survival outcomes in GBC and prognostic factors. Clinicopathologic features, survival outcomes were analyzed in 692 consecutive GBC patients who underwent surgery between 1987 and 2014, including 255 treated in Period (P) 1 (1987-2000) and 437 in P2 (2001-2014). The mean age was 63.3 years. Curative resection rate was 59.2% and 5-year survival rate (5-YSR) after curative resection was 67.1%. Comparisons between P1 and P2 showed that mean age, asymptomatic presentation, extended cholecystectomy, curative resection, adjuvant chemotherapy, and tumor ≤ T2 were significantly higher during P2. The overall 5-YSR after curative surgery was significantly lower in P1. In patients who underwent curative resection, poor prognostic factors included symptomatic presentation, CA 19-9 > 37 IU/ml, poor ...

Research paper thumbnail of Metabolic effect of pancreatoduodenectomy: resolution of diabetes mellitus after surgery

Pancreatology, 2016

It is considered natural that glucose tolerance worsens after pancreatectomy. However, diabetes m... more It is considered natural that glucose tolerance worsens after pancreatectomy. However, diabetes mellitus (DM) resolves after metabolic bypass surgery and anatomic changes after PD resemble those after metabolic surgery. This study assessed the incidence of DM resolution after pancreatectomy and differences in metabolic parameters following pancreatoduodenectomy (PD) and distal pancreatectomy (DP). Between 2007 and 2013, 218 consecutive patients with pancreatic diseases underwent PD (n = 112) or DP (n = 106) at Seoul National University Hospital. Factors associated with changes in glucose homeostasis were evaluated by assaying serum glucose concentrations in prospectively collected samples. Of the 218 patients, 88 (40.4%) had preoperative DM, with 27 (30.7%) of the latter showing postoperative resolution of DM, a rate significantly higher in patients who had undergone PD than DP (40.4% vs. 12.9%, p = 0.008). Fasting blood glucose (p = 0.001), PP2 (p < 0.001), and HOMA-IR (p = 0.005) significantly decreased after PD but not after DP. Multivariate analysis revealed that PD was independently associated with DM resolution (odds ratio 7.790, p = 0.003). PD was associated with a significantly higher DM resolution rate than DP among the 37 pancreatic cancer patients with preoperative DM (34.6% vs. 0%, p = 0.036). DM resolution rates were similar in pancreatic cancer and other pancreatic diseases (p = 0.419). More than 40% of patients with preoperative DM show resolution after PD. Decreased insulin resistance and suspected enhanced glucose stimulated insulin secretion decreasing PP2 seem to contribute improved glucose homeostasis after PD. BMI was unrelated to DM resolution, indicating that PD-associated physio-anatomical changes may help resolve DM independent of weight.

Research paper thumbnail of Care Status of the ALS Patients With Long-Term Use of Tracheostomy Tube

Annals of rehabilitation medicine, 2015

To evaluate the care status of the amyotrophic lateral sclerosis (ALS) patients with long-term us... more To evaluate the care status of the amyotrophic lateral sclerosis (ALS) patients with long-term use of tracheostomy tube by caregivers of ALS patients. A survey was conducted in the form of questionnaires to ALS patients and their caregivers. All measurements were performed by two visiting nurses. For statistical analysis, SPSS ver. 22.0 and Mann-Whitney U test on non-normal distribution were used. In total, 19 patients (15 males and 4 females) and their caregivers participated in the survey. In the case of patients, the average duration of care was 5.9±3.7 years, and the mean periods of illness and tracheostomy were 5.3±3.2 years and 3.0±2.6 years, respectively. Replacement intervals were 14 days in 11 patients, 7 days in 4 patients, 28 days in 2 patients, and 21 days in 1 patient. One patient was unable to provide an accurate replacement interval. Eighteen (99%) caregivers had experience of adding volume to a cuff without pressure measure in the following instances: due to patients...

Research paper thumbnail of The clinical usefulness of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in follow-up of curatively resected pancreatic cancer patients

HPB : the official journal of the International Hepato Pancreato Biliary Association, 2016

Computed tomography and serum tumor markers have limited value in detecting recurrence after cura... more Computed tomography and serum tumor markers have limited value in detecting recurrence after curative surgery of pancreatic cancer. This study evaluated the clinical utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in diagnosing recurrence. One hundred ten patients underwent curative resection of pancreatic cancer were enrolled. The diagnostic value of abdominal computed tomography (CT), PET-CT and serum carbohydrate antigen (CA) 19-9 concentration were compared. The prognostic value of SUVmax on PET-CT was evaluated. PET-CT showed relatively higher sensitivity (84.5% vs. 75.0%) and accuracy (84.5% vs. 74.5%) than CT, whereas PET-CT plus CT showed greater sensitivity (97.6%) and accuracy (90.0%) than either alone. In detecting distant recurrences, PET-CT showed higher sensitivity (83.1% vs. 67.7%) than CT. Nineteen patients showed recurrences only on PET-CT, with eleven having invisible or suspected benign lesions on CT, and eight had recur...

Research paper thumbnail of Multiphoton imaging of myogenic differentiation in gelatin-based hydrogels as tissue engineering scaffolds

Biomaterials research, 2016

Hydrogels can serve as three-dimensional (3D) scaffolds for cell culture and be readily injected ... more Hydrogels can serve as three-dimensional (3D) scaffolds for cell culture and be readily injected into the body. Recent advances in the image technology for 3D scaffolds like hydrogels have attracted considerable attention to overcome the drawbacks of ordinary imaging technologies such as optical and fluorescence microscopy. Multiphoton microscopy (MPM) is an effective method based on the excitation of two-photons. In the present study, C2C12 myoblasts differentiated in 3D gelatin hydroxyphenylpropionic acid (GHPA) hydrogels were imaged by using a custom-built multiphoton excitation fluorescence microscopy to compare the difference in the imaging capacity between conventional microscopy and MPM. The physicochemical properties of GHPA hydrogels were characterized by using scanning electron microscopy and Fourier-transform infrared spectroscopy. In addition, the cell viability and proliferation of C2C12 myoblasts cultured in the GHPA hydrogels were analyzed by using Live/Dead Cell and ...

Research paper thumbnail of Enhanced Osteogenesis by Reduced Graphene Oxide/Hydroxyapatite Nanocomposites

Scientific reports, 2015

Recently, graphene-based nanomaterials, in the form of two dimensional substrates or three dimens... more Recently, graphene-based nanomaterials, in the form of two dimensional substrates or three dimensional foams, have attracted considerable attention as bioactive scaffolds to promote the differentiation of various stem cells towards specific lineages. On the other hand, the potential advantages of using graphene-based hybrid composites directly as factors inducing cellular differentiation as well as tissue regeneration are unclear. This study examined whether nanocomposites of reduced graphene oxide (rGO) and hydroxyapatite (HAp) (rGO/HAp NCs) could enhance the osteogenesis of MC3T3-E1 preosteoblasts and promote new bone formation. When combined with HAp, rGO synergistically promoted the spontaneous osteodifferentiation of MC3T3-E1 cells without hindering their proliferation. This enhanced osteogenesis was corroborated from determination of alkaline phosphatase activity as early stage markers of osteodifferentiation and mineralization of calcium and phosphate as late stage markers. I...

Research paper thumbnail of Use of TachoSil(®) patches to prevent pancreatic leaks after distal pancreatectomy: a prospective, multicenter, randomized controlled study

Journal of hepato-biliary-pancreatic sciences, Jan 17, 2015

We performed a prospective, multicenter, randomized controlled study to investigate the clinical ... more We performed a prospective, multicenter, randomized controlled study to investigate the clinical outcomes, including POPF, after using the TachoSil(®) patch in distal pancreatectomy (NCT01550406). Between June 2012 and September 2014, 101 patients at 5 centers were randomized into Control (n = 53) and TachoSil (n = 48) groups. In all patients, the pancreas was resected using a stapler with Endo-GIA™ staples. The TachoSil patch was wrapped around the pancreatic stump only in the TachoSil group, not in Control group. The patient characteristics, including age and diagnosis, were comparable in both groups. The mean operation time (159.4 vs 172.3 min, P = 0.081) and postoperative hospital stay (10.0 vs 9.7 days, P = 0.279) were similar in the Control and TachoSil groups, respectively. The overall incidence of POPF was 62.4% (n = 63). The distribution of grades A, B, and C POPF was similar in the Control (14/14/1) and TachoSil (23/11/0) groups, as were the overall incidence (54.7% vs 70....

Research paper thumbnail of Chemical characteristics and enhanced hepatoprotective activities of Maillard-reaction products derived from milk protein-sugar system

Journal of dairy science, Jan 25, 2015

The objective of this study was to investigate the characteristics, antioxidative properties, and... more The objective of this study was to investigate the characteristics, antioxidative properties, and hepatoprotective effects of Maillard reaction products (MRP) from milk protein reacted with sugars. The MRP were obtained from milk protein, whey protein concentrates and sodium caseinate, using 2 types of sugars, lactose and glucose, by heating the mixture at 55°C for 7 d in a sodium phosphate buffer (pH 7.4). Changes in the chemical modification of the milk protein were monitored by measuring the protein-bound carbonyls and PAGE protein profiles. The results showed that the amount of protein-bound carbonyls increased after Maillard reaction (MR). In addition, sodium dodecyl sulfate-PAGE analysis indicated a formation of high-molecular weight complexes through MR. The modification sites induced by MR of milk protein were monitored by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of tryptic-digested gel spots of MRP. As a result, modification and ...

Research paper thumbnail of Stimulating effect of graphene oxide on myogenesis of C2C12 myoblasts on RGD peptide-decorated PLGA nanofiber matrices

Journal of biological engineering, 2015

In the field of biomedical engineering, many studies have focused on the possible applications of... more In the field of biomedical engineering, many studies have focused on the possible applications of graphene and related nanomaterials due to their potential for use as scaffolds, coating materials and delivery carriers. On the other hand, electrospun nanofiber matrices composed of diverse biocompatible polymers have attracted tremendous attention for tissue engineering and regenerative medicine. However, their combination is intriguing and still challenging. In the present study, we fabricated nanofiber matrices composed of M13 bacteriophage with RGD peptide displayed on its surface (RGD-M13 phage) and poly(lactic-co-glycolic acid, PLGA) and characterized their physicochemical properties. In addition, the effect of graphene oxide (GO) on the cellular behaviors of C2C12 myoblasts, which were cultured on PLGA decorated with RGD-M13 phage (RGD/PLGA) nanofiber matrices, was investigated. Our results revealed that the RGD/PLGA nanofiber matrices have suitable physicochemical properties as...

Research paper thumbnail of Anti-inflammatory effect of desoxo-narchinol-A isolated from Nardostachys jatamansi against lipopolysaccharide

International immunopharmacology, Jan 11, 2015

We previously reported that Nardostachys jatamansi (NJ) exhibits anti-inflammatory activity again... more We previously reported that Nardostachys jatamansi (NJ) exhibits anti-inflammatory activity against lipopolysaccharide (LPS). However, the active compound in NJ is unknown. Therefore, here, we examined the effects of desoxo-narchinol-A (DN) isolated from NJ against LPS-induced inflammation. To demonstrate the anti-inflammatory effect of DN against LPS, we used two models; murine endotoxin shock model for in vivo model, and peritoneal macrophage responses for in vitro. In endotoxin shock model, DN was administrated intraperitoneally 1h before LPS challenge, then we evaluated mice survival rates and organ damages. Pretreatment with DN (0.05mg/kg, 0.1mg/kg, or 0.5mg/kg) dramatically reduced mortality in a murine LPS-induced endotoxin shock model. Furthermore, DN inhibited tissue injury and production of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α), in the liver and lung. In in vitro macrophage model, we examined the inflammatory...

Research paper thumbnail of Effects of Surgical Methods and Tumor Location on Survival and Recurrence Patterns after Curative Resection in Patients with T2 Gallbladder Cancer

Gut and liver, Jan 9, 2015

Extended cholecystectomy is generally recommended for patients with T2 gallbladder cancer. Howeve... more Extended cholecystectomy is generally recommended for patients with T2 gallbladder cancer. However, few studies have assessed the extent of resection relative to T2 gallbladder tumor location. This study analyzed the effects of surgical methods and tumor location on survival outcomes and tumor recurrence in patients with T2 gallbladder cancer. Clinicopathological characteristics, extent of resection, survival rates, and recurrence patterns were retrospectively analyzed in 88 patients with pathologically confirmed T2 gallbladder cancer. The 5-year disease-free survival rate was 65.0%. Multivariate analysis showed that lymph node metastasis was the only independent risk factor for poor 5-year disease-free survival rate. Survival outcomes were not associated with tumor location. Survival tended to be better in patients who underwent extended cholecystectomy than in those who underwent simple cholecystectomy. Recurrence rate was not affected by surgical method or tumor location. Systemi...

Research paper thumbnail of Cell-adhesive RGD peptide-displaying M13 bacteriophage/PLGA nanofiber matrices for growth of fibroblasts

Biomaterials research, 2014

M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with ... more M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with a nanofiber-like shape. In the present study, we prepared hybrid nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and M13 bacteriophages which were genetically modified to display the RGD peptide on their surface (RGD-M13 phage). The surface morphology and chemical composition of hybrid nanofiber matrices were characterized by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. Immunofluorescence staining was conducted to investigate the existence of M13 bacteriophages in RGD-M13 phage/PLGA hybrid nanofibers. In addition, the attachment and proliferation of three different types of fibroblasts on RGD-M13 phage/PLGA nanofiber matrices were evaluated to explore how fibroblasts interact with these matrices. SEM images showed that RGD-M13 phage/PLGA hybrid matrices had the non-woven porous structure, quite similar to that of natural extracellular matric...

Research paper thumbnail of Efficacy of Systemic Postoperative Pulmonary Rehabilitation After Lung Resection Surgery

Annals of rehabilitation medicine, 2015

To investigate the efficacy of systemic pulmonary rehabilitation (PR) after lung resection in pat... more To investigate the efficacy of systemic pulmonary rehabilitation (PR) after lung resection in patients with lung cancer. Forty-one patients undergoing lung resection were enrolled and classified into the experimental (n=31) and control groups (n=10). The experimental group underwent post-operative systemic PR which was conducted 30 min/day on every hospitalization day by an expert physical therapist. The control group received the same education about the PR exercises and were encouraged to self-exercise without supervision of the physical therapist. The PR group was taught a self-PR program and feedback was provided regularly until 6 months after surgery. We conducted pulmonary function testing (PFT) and used a visual analog scale (VAS) to evaluate pain, and the modified Borg Dyspnea Scale (mBS) to measure perceived respiratory exertion shortly before and 2 weeks, 1, 3, and 6 months after surgery. A significant improvement on the VAS was observed in patients who received systemic P...

Research paper thumbnail of In vivo RNAi screen identifies NLK as a negative regulator of mesenchymal activity in Glioblastoma

Oncotarget, Jan 19, 2015

Glioblastoma (GBM) is the most lethal brain cancer with profound genomic alterations. While the b... more Glioblastoma (GBM) is the most lethal brain cancer with profound genomic alterations. While the bona fide tumor suppressor genes such as PTEN, NF1, and TP53 have high frequency of inactivating mutations, there may be the genes with GBM-suppressive roles for which genomic mutation is not a primary cause for inactivation. To identify such genes, we employed in vivo RNAi screening approach using the patient-derived GBM xenograft models. We found that Nemo-Like Kinase (NLK) negatively regulates mesenchymal activities, a characteristic of aggressive GBM, in part via inhibition of WNT/β-catenin signaling. Consistent with this, we found that NLK expression is especially low in a subset of GBMs that harbors high WNT/mesenchymal activities. Restoration of NLK inhibited WNT and mesenchymal activities, decreased clonogenic growth and survival, and impeded tumor growth in vivo. These data unravel a tumor suppressive role of NLK and support the feasibility of combining oncogenomics with in vivo ...

Research paper thumbnail of Pi30 DNA Probe May Be Useful for the Identification of Prevotella intermedia at the Species or Strain Level

Microbiology and Immunology, 2004