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1.  Use of Surgical Sponge with Running Sutures for Securing Full-Thickness Skin Grafts 
ISRN Dermatology  2011;2011:470921.
One of the most common methods of skin defect repairing is the use of a skin graft. It is simple and reliable technique, although sometimes it is not totally successful due to hematoma and seroma formation between the skin graft and the recipient bed. Here in, we present a method to secure the skin grafts using a surgical sponge with two running sutures. This technique ensures high survival rate of the skin grafts, and in addition it is easy to be performed by the surgeon only.
doi:10.5402/2011/470921
PMCID: PMC3262541  PMID: 22363852
2.  The clinical usefulness of central hemodynamics to evaluate diastolic dysfunction in subjects without hypertension 
Objective
Diastolic dysfunction is associated with increased arterial stiffness in patients with hypertension. However, the role of arterial stiffness in diastolic dysfunction in subjects without hypertension has not been fully established.
Materials and methods
A total of 287 subjects (male:female ratio 121:166, mean age 53.0±14.4 years) without hypertension or any heart disease who simultaneously received transthoracic echocardiography and noninvasively semiautomated radial artery applanation tonometry (with an Omron HEM-9000AI) in the Department of Internal Medicine, St Vincent’s Hospital, from July 2011 to September 2012, were enrolled in this study.
Results
A total of 147 subjects (male:female ratio 59:88, mean age 61.7±9.9 years), representing 51.2% of the 287 subjects, had diastolic dysfunction (defined as abnormal relaxation pattern of mitral inflow). There were significant differences in systolic blood pressure (BP), pulse pressure, late systolic peak pressure (SBP2), and radial augmentation index (RaAIx) between normal diastolic function and diastolic dysfunction. ΔBP was defined as systolic BP minus SBP2, because of the difference in systolic BP between the two groups. ΔBP (odds ratio [OR] 1.059, 95% confidence interval [CI] 1.005–1.115; P=0.032) and RaAIx (odds ratio 1.027, 95% CI 1.009–1.044, P=0.003) were associated with diastolic dysfunction. A receiver operating-characteristic curve showed that ΔBP (area under the curve 0.875, 95% CI 0.832–0.911) and RaAIx (area under the curve 0.878, 95% CI 0.835–0.914) were associated with diastolic dysfunction.
Conclusion
We found that ΔBP and increased RaAIx were associated with diastolic dysfunction in subjects without hypertension after adjustment for age and sex. Therefore, it is suggested that noninvasive estimation of central BP may be useful to reflect diastolic dysfunction in subjects with normal peripheral BP.
doi:10.2147/CIA.S58810
PMCID: PMC3974697
central blood pressure; augmentation index; diastolic dysfunction
3.  How good is cola for dissolution of gastric phytobezoars? 
AIM: To evaluate the efficacy of cola treatment for gastric phytobezoars, including diospyrobezoars.
METHODS: A total of 17 patients (range: 48 to 78 years) with symptomatic gastric phytobezoars treated with cola and adjuvant endoscopic therapy were reviewed. Three liters of cola lavage (10 cases) or drink (7 cases) were initially used, and then endoscopic fragmentation was done for the remnant bezoars by using a lithotripsy basket or a polypectomy snare. The overall success of dissolving a gastric phytobezoars with using three liters of cola and the clinical and endoscopic findings were compared retrospectively between four cases of complete dissolution by using only cola and 13 cases of partial dissolution with cola.
RESULTS: After 3 L of cola lavage or drinking, a complete dissolution of bezoars was achieved in four patients (23.5%), while 13 cases (76.5%) were only partially dissolved. Phytobezoars (4 of 6 cases) were observed more frequently than diospyrobezoars (0 of 11) in the group that underwent complete dissolution (P = 0.006). Gender, symptom duration, size of bezoar and method of cola administration were not significantly different between the two groups. Twelve of 13 patients with residual bezoars were completely treated with a combination of cola and endoscopic fragmentation.
CONCLUSION: The rate of complete dissolution with three liters of cola was 23.5%, but no case of diospyrobezoar was completely dissolved using this method. However, pretreatment with cola may be helpful and facilitate endoscopic fragmentation of gastric phytobezoars.
doi:10.3748/wjg.15.2265
PMCID: PMC2682243  PMID: 19437568
Gastric phytobezoars; Diospyrobezoars; Cola; Dissolution; Clinical efficacy
4.  Clinical Utility of Plasma Glypican-3 and Osteopontin as Biomarkers of Hepatocellular Carcinoma 
Gut and Liver  2013;8(2):177-185.
Background/Aims
α-Fetoprotein (AFP) is the biomarker most widely used to detect hepatocellular carcinoma (HCC), despite its suboptimal diagnostic accuracy. Glypican-3 (GPC3) and osteopontin (OPN) are secreted glycoproteins that are reportedly associated with tumorigenesis and metastasis. This study was conducted to evaluate the clinical utility of using plasma GPC3 and OPN as diagnostic biomarkers for HCC.
Methods
We measured the plasma levels of GPC3 and OPN in 120 HCC and 40 chronic liver disease (CLD) patients via an enzyme-linked immunosorbent assay. The diagnostic accuracy of each tumor marker was evaluated using receiver operating characteristic (ROC) curve analysis.
Results
The GPC3 levels in the HCC patients (75.8 ng/mL) were significantly higher (p=0.020) than the levels in patients with CLD (66.4 ng/mL). The area under the ROC curve (AUROC) values for GPC3 and OPN were 0.62 and 0.51, respectively. In subgroup analyses, including subgroups of HCC patients with low serum AFP and PIVKA II levels, the AUROC of GPC3 remained relatively high (0.66), and GPC3 showed a high sensitivity (62.1%) for detecting small HCC tumors.
Conclusions
The plasma levels of GPC3 and OPN demonstrated low diagnostic accuracy for HCC. However, GPC3 may have a complementary role in diagnosing HCC in patients with nondiagnostic levels of conventional tumor markers and with small-sized tumors.
doi:10.5009/gnl.2014.8.2.177
PMCID: PMC3964269  PMID: 24672660
Hepatocellular carcinoma; Glypican-3; Osteopontin
5.  Is propofol safe when administered to cirrhotic patients during sedative endoscopy? 
Background/Aims
In patients with liver cirrhosis, drugs acting on the central nervous system can lead to hepatic encephalopathy and the effects may be prolonged. Recently, misuse of propofol has been reported and the associated risk of death have become an issue. Propofol is commonly used during sedative endoscopy; therefore, its safety in high-risk groups must be further investigated. We performed a pilot study of the safety and efficacy of propofol during endoscopy in Korean patients with cirrhosis.
Methods
Upper gastrointestinal endoscopy was performed under sedation with propofol along with careful monitoring in 20 patients with liver cirrhosis and 20 control subjects. The presence or development of hepatic encephalopathy was assessed using the number connection test and neurologic examination.
Results
Neither respiratory depression nor clinically significant hypotension were observed. Immediate postanesthetic recovery at 5 and 10 minutes after the procedure was delayed in the cirrhotic patients compared with the control group; however, at 30 minutes, the postanesthetic recovery was similar in both groups. Baseline psychomotor performance was more impaired in cirrhotic patients, but propofol was not associated with deteriorated psychomotor function even in cirrhotic patients with a minimal hepatic encephalopathy.
Conclusions
Sedation with propofol was well tolerated in cirrhotic patients. No newly developed hepatic encephalopathy was observed.
doi:10.3904/kjim.2014.29.1.57
PMCID: PMC3932396  PMID: 24574834
Propofol; Sedative endoscopy; Hepatic encephalopathy; Liver cirrhosis
6.  Stereospecific anticancer effects of ginsenoside Rg3 epimers isolated from heat-processed American ginseng on human gastric cancer cell 
Journal of Ginseng Research  2013;38(1):22-27.
Background
Research has been conducted with regard to the development of methods for improving the pharmaceutical effect of ginseng by conversion of ginsenosides, which are the major active components of ginseng, via high temperature or high-pressure processing.
Methods
The present study sought to investigate the anticancer effect of heat-processed American ginseng (HAG) in human gastric cancer AGS cells with a focus on assessing the role of apoptosis as an important mechanistic element in its anticancer actions.
Results and Conclusion
HAG significantly reduced the cancer cell proliferation, and the contents of ginsenosides Rb1 and Re were markedly decreased, whereas the peaks of less-polar ginsenosides [20(S,R)-Rg3, Rk1, and Rg5] were newly detected. Based on the activity-guided fractionation of HAG, ginsenoside 20(S)-Rg3 played a key role in inducing apoptosis in human gastric cancer AGS cells, and it was generated mainly from ginsenoside Rb1. Ginsenoside 20(S)-Rg3 induced apoptosis through activation of caspase-3, caspase-8, and caspase-9, as well as regulation of Bcl-2 and Bax expression. Taken together, these findings suggest that heat-processing serves as an increase in the antitumor activity of American ginseng in AGS cells, and ginsenoside 20(S)-Rg3, the active component produced by heat-processing, induces the activation of caspase-3, caspase-8, and caspase-9, which contributes to the apoptotic cell death.
doi:10.1016/j.jgr.2013.11.007
PMCID: PMC3915326  PMID: 24558306
American ginseng; ginsenoside20(S)-Rg3; heat processing; Panax quinquefolius
8.  Tumor Lysis Syndrome in a Solid Tumor: A Case Report of a Patient with Invasive Thymoma 
Tumor lysis syndrome (TLS) has rarely been observed in solid tumors. We report on a case of a patient with advanced invasive thymoma who developed tumor lysis syndrome after chemotherapy. The potential complications of TLS should be considered in treatment of extensive thymoma.
doi:10.4143/crt.2013.45.4.343
PMCID: PMC3893332  PMID: 24454007
Thymoma; Drug therapy; Tumor lysis syndrome; Hyperuricemia; Acute kidney injury
9.  Effect of Gum Chewing on the Recovery From Laparoscopic Colorectal Cancer Surgery 
Annals of Coloproctology  2013;29(6):248-251.
Purpose
We aimed to examine the effect of gum chewing after laparoscopic colorectal cancer surgery.
Methods
We reviewed the medical records of patients who underwent laparoscopic colorectal cancer surgery in Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine. We divided the patients into 2 groups: group A consisted of 67 patients who did not chew gum; group B consisted of 65 patients who chewed gum. We analyzed the short-term clinical outcomes between the two groups to evaluate the effect of gum chewing.
Results
The first passage of gas was slightly earlier in group B, but the difference was not significant. However, the length of hospital stay was 6.7 days in group B, which was significantly shorter than that in group A (7.3 days, P = 0.018).
Conclusion
This study showed that length of postoperative hospital stay was shorter in the gum-chewing group. In future studies, we expect to elucidate the effect of gum chewing on the postoperative recovery more clearly.
doi:10.3393/ac.2013.29.6.248
PMCID: PMC3895549  PMID: 24466540
Chewing gum; Colorectal neoplasms; Laparoscopy; Sham feeding
10.  Hepatitis A virus infection during pregnancy in Korea: Hepatitis A infection on pregnant women 
Obstetrics & Gynecology Science  2013;56(6):368-374.
Objective
Although there is a large body of data on acute hepatitis A virus (HAV) worldwide, data regarding the occurrence of HAV during pregnancy is limited. It is commonly acknowledged that HAV is not associated with severe outcomes or complications during pregnancy. In contrast, there are several reported cases of vertical HAV transmission. Moreover, it has been recently reported that HAV infection during pregnancy is associated with gestational complications. In Korea, the incidence of HAV infection has increased from 317 cases in 2002 to 13,117 cases in 2009. However, HAV infection during pregnancy is rarely reported in Korea.
Methods
This study was conducted as a retrospective cohort series of pregnant women presenting to Korea University Medical Center between January 2000 and October 2009 in whom a diagnosis of HAV infection was made.
Results
During study period, there were 12 cases of HAV in pregnant women, including two cases with preterm contraction, two cases with cholestatic hepatitis, and one case with fetal ascites and intra-abdominal calcification.
Conclusion
HAV infection during pregnancy is associated with high prevalence of maternal and fetal complications. Because the incidence of HAV infection in women of reproductive age is increasing, a further focus on preventing HAV infection during pregnancy is warranted.
doi:10.5468/ogs.2013.56.6.368
PMCID: PMC3859013  PMID: 24396815
Hepatitis A; Pregnancy; Pregnancy complications
12.  Heart rate variability as a predictor of hypotension after spinal anesthesia in hypertensive patients 
Korean Journal of Anesthesiology  2013;65(4):317-321.
Background
Hypotension is a common phenomenon after spinal anesthesia in hypertensive patients. We investigated whether heart rate variability could predict the occurrence of hypotension after spinal anesthesia in hypertensive patients.
Methods
Forty-one patients undergoing spinal anesthesia were included. Heart rate variability was measured at five different time points such as before fluid loading (baseline), after fluid loading as well as 5 min, 15 min and 30 min after spinal anesthesia. Fluid loading was performed using 5 ml/kg of a crystalloid solution. Baseline total power and low to high frequency ratio (LF/HF) in predicting hypotension after spinal anesthesia were analyzed by calculating the area under the receiver operating characteristic curves (AUC).
Results
Moderate hypotension, defined as a decrease of mean arterial pressure to below 20-30% of the baseline, occurred in 13 patients and severe hypotension, defined as a decrease of mean arterial pressure greater than 30% below the baseline, occurred in 7 patients. LF/HF ratiosand total powers did not significantly change after spinal anesthesia. AUCs of LF/HF ratio for predicting moderate hypotension was 0.685 (P = 0.074), severe hypotension was 0.579 (P = 0.560) and moderate or severe hypotension was 0.652 (P = 0.101), respectively. AUCs of total power for predicting moderate hypotension was 0.571 (P = 0.490), severe hypotension was 0.672 (P = 0.351) and moderate or severe hypotension was 0.509 (P = 0.924), respectively.
Conclusions
Heart rate variability is not a reliable predictor of hypotension after spinal block in hypertensive patients whose sympathetic activity is already depressed.
doi:10.4097/kjae.2013.65.4.317
PMCID: PMC3822023  PMID: 24228144
Hypertension; Hypotension; Parasympathetic nervous system; Spinal anesthesia; Sympathetic nervous system
13.  Early Gastric Cancer with Neurofibroma Mimicking a Metastatic Node: A Case Report 
Journal of Gastric Cancer  2013;13(3):185-187.
Neurofibromas are benign tumors that originate from the peripheral nerves, including neurites and fibroblasts. Generally, a solitary neurofibroma is located in the skin and rarely in other places. A 72-year-old female suffered from epigastric discomfort for 2 months. Endoscopic findings showed an early gastric cancer type IIc at the antrum. Abdominal computed tomography revealed early gastric cancer with a 1.6 cm-sized metastatic node posterior to the duodenum. Laparoscopic assisted distal gastrectomy and retro-pancreatic dissection were performed uneventfully. Histological examination revealed gastric adenocarcinoma, invading the mucosa without nodal metastasis, and a neurofibroma. Herein, we present a case of a gastric cancer patient with a solitary retroperitoneal neurofibroma which mimicked a distant metastatic node.
doi:10.5230/jgc.2013.13.3.185
PMCID: PMC3804678  PMID: 24156039
Neurofibroma; Stomach neoplasms; Lymphatic metastasis
14.  Cerebral Blood Volume Calculated by Dynamic Susceptibility Contrast-Enhanced Perfusion MR Imaging: Preliminary Correlation Study with Glioblastoma Genetic Profiles 
PLoS ONE  2013;8(8):e71704.
Purpose
To evaluate the usefulness of dynamic susceptibility contrast (DSC) enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas.
Materials and Methods
Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years) with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV) of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway) that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR), phosphatase and tensin homologue (PTEN), Ki-67, O6-methylguanine-DNA methyltransferase (MGMT) and p53) were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic) curve analysis and Pearson correlation analysis.
Results
The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5) were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8) (p = .046). In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1) were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3) (p = .046). Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01).
Conclusion
We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.
doi:10.1371/journal.pone.0071704
PMCID: PMC3747204  PMID: 23977117
15.  Cerebral Blood Volume Analysis in Glioblastomas Using Dynamic Susceptibility Contrast-Enhanced Perfusion MRI: A Comparison of Manual and Semiautomatic Segmentation Methods 
PLoS ONE  2013;8(8):e69323.
Purpose
To compare the reproducibilities of manual and semiautomatic segmentation method for the measurement of normalized cerebral blood volume (nCBV) using dynamic susceptibility contrast-enhanced (DSC) perfusion MR imaging in glioblastomas.
Materials and Methods
Twenty-two patients (11 male, 11 female; 27 tumors) with histologically confirmed glioblastoma (WHO grade IV) were examined with conventional MR imaging and DSC imaging at 3T before surgery or biopsy. Then nCBV (means and standard deviations) in each mass was measured using two DSC MR perfusion analysis methods including manual and semiautomatic segmentation method, in which contrast-enhanced (CE)-T1WI and T2WI were used as structural imaging. Intraobserver and interobserver reproducibility were assessed according to each perfusion analysis method or each structural imaging. Interclass correlation coefficient (ICC), Bland-Altman plot, and coefficient of variation (CV) were used to evaluate reproducibility.
Results
Intraobserver reproducibilities on CE-T1WI and T2WI were ICC of 0.74–0.89 and CV of 20.39–36.83% in manual segmentation method, and ICC of 0.95–0.99 and CV of 8.53–16.19% in semiautomatic segmentation method, repectively. Interobserver reproducibilites on CE-T1WI and T2WI were ICC of 0.86–0.94 and CV of 19.67–35.15% in manual segmentation method, and ICC of 0.74–1.0 and CV of 5.48–49.38% in semiautomatic segmentation method, respectively. Bland-Altman plots showed a good correlation with ICC or CV in each method. The semiautomatic segmentation method showed higher intraobserver and interobserver reproducibilities at CE-T1WI-based study than other methods.
Conclusion
The best reproducibility was found using the semiautomatic segmentation method based on CE-T1WI for structural imaging in the measurement of the nCBV of glioblastomas.
doi:10.1371/journal.pone.0069323
PMCID: PMC3738566  PMID: 23950891
16.  Diabetic Retinopathy and Endothelial Dysfunction in Patients with Type 2 Diabetes Mellitus 
Diabetes & Metabolism Journal  2013;37(4):262-269.
Background
We investigated the relationship between endothelial dysfunction and diabetic retinopathy (DR) in patients with type 2 diabetes.
Methods
We used a cross-sectional design to examine 167 patients with type 2 diabetes mellitus. All patients underwent biochemical and ophthalmological examination. We assessed endothelial dysfunction by a flow-mediated vasodilation method of the brachial artery. Changes in vasodilation (flow-mediated vasodilatation, %FMD) were expressed as percent change over baseline values.
Results
The mean±standard deviation of patient age was 54.1±8.6 years. The %FMD was significantly lower in patients with DR than without DR. The prevalence of retinopathy decreased across increasing tertiles of %FMD. After adjusting for patients' age, sex, diabetes duration, use of insulin, use of antihypertensive, antiplatelet, and lipid lowering medications, systolic blood pressure, fasting plasma glucose, 2-hour plasma glucose, glycated hemoglobin, and urinary albumin excretion, participants with a reduced %FMD were more likely to have DR (odds ratio, 11.819; 95% confidence interval, 2.201 to 63.461; P=0.004, comparing the lowest and highest tertiles of %FMD).
Conclusion
Endothelial dysfunction was associated with DR, which was most apparent when the endothelial dysfunction was severe. Our study provides insights into the possible mechanism of the influence of endothelial dysfunction on the development of DR.
doi:10.4093/dmj.2013.37.4.262
PMCID: PMC3753491  PMID: 23991404
Diabetes mellitus, type 2; Diabetic retinopathy; Endothelial dysfunction; Flow-mediated vasodilation
17.  Effects of the Temporary Placement of a Self-Expandable Metallic Stent in Benign Pyloric Stenosis 
Gut and Liver  2013;7(4):417-422.
Background/Aims
The use of self-expandable metallic stents (SEMS) is an established palliative treatment for malignant stenosis in the gastrointestinal tract; therefore, its application to benign stenosis is expected to be beneficial because of the more gradual and sustained dilatation in the stenotic portion. We aimed in this prospective observational study to evaluate the efficacy and safety of temporary SEMS placement in benign pyloric stenosis.
Methods
Twenty-two patients with benign stenosis of the prepylorus, pylorus, and duodenal bulb were enrolled and underwent SEMS placement. We assessed symptom improvement, defined as an increase of at least 1 degree in the gastric-outlet-obstruction scoring system after stent insertion.
Results
No major complications were observed during the procedures. After stent placement, early symptom improvement was achieved in 18 of 22 patients (81.8%). During the follow-up period (mean 10.2 months), the stents remained in place successfully for 6 to 8 weeks in seven patients (31.8%). Among the 15 patients (62.5%) with stent migration, seven (46.6%) showed continued symptomatic improvement without recurrence of obstructive symptoms.
Conclusions
Despite the symptomatic improvement, temporary SEMS placement is premature as an effective therapeutic tool for benign pyloric stenosis unless a novel stent is developed to prevent migration.
doi:10.5009/gnl.2013.7.4.417
PMCID: PMC3724029  PMID: 23898381
Benign pyloric stenosis; Self-expandable metallic stent
18.  Hyperfunction Thyroid Nodules: Their Risk for Becoming or Being Associated with Thyroid Cancers 
Korean Journal of Radiology  2013;14(4):643-652.
Objective
To retrospectively evaluate the risk of thyroid cancer in patients with hyperfunctioning thyroid nodules through ultrasonographic-pathologic analysis.
Materials and Methods
Institutional review board approval was obtained and informed consent was waived. From 2003 to 2007, 107 patients consecutively presented with hot spots on thyroid scans and low serum thyroid-stimulating hormone levels. Among them, 32 patients who had undergone thyroid ultrasonography were analyzed in this study. Thyroid nodules depicted on ultrasonography were classified based on size and categorized as benign, indeterminate, or suspicious malignant nodules according to ultrasonographic findings. The thyroid nodules were determined as either hyperfunctioning or coexisting nodules and were then correlated with pathologic results.
Results
In 32 patients, 42 hyperfunctioning nodules (mean number per patient, 1.31; range, 1-6) were observed on thyroid scans and 68 coexisting nodules (mean, 2.13; range, 0-7) were observed on ultrasonography. Twenty-five patients (78.1%) had at least one hyperfunctioning (n = 17, 53.1%) or coexisting (n = 16, 50.0%) nodule that showed a suspicious malignant feature larger than 5 mm (n = 8, 25.0%), or an indeterminate feature 1 cm or greater (n = 20, 62.5%) in diameter, which could have been indicated by using fine needle aspiration (FNA). Seven patients were proven to have 11 thyroid cancers in 3 hyperfunctioning and 8 coexisting nodules. All of these had at least one thyroid cancer, which could have been indicated by using FNA. The estimated minimal risk of thyroid cancer was 6.5% (7/107).
Conclusion
Patients with hyperfunctioning nodules may not be safe from thyroid cancer because hyperfunctioning nodules can coexist with thyroid cancer nodules. To screen out these cancers, ultrasonography should be performed.
doi:10.3348/kjr.2013.14.4.643
PMCID: PMC3725360  PMID: 23901323
Hyperfunctioning nodule; Radionuclide imaging; Thyroid cancer; Ultrasonography; Guideline
19.  True Progression versus Pseudoprogression in the Treatment of Glioblastomas: A Comparison Study of Normalized Cerebral Blood Volume and Apparent Diffusion Coefficient by Histogram Analysis 
Korean Journal of Radiology  2013;14(4):662-672.
Objective
The purpose of this study was to differentiate true progression from pseudoprogression of glioblastomas treated with concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ) by using histogram analysis of apparent diffusion coefficient (ADC) and normalized cerebral blood volume (nCBV) maps.
Materials and Methods
Twenty patients with histopathologically proven glioblastoma who had received CCRT with TMZ underwent perfusion-weighted imaging and diffusion-weighted imaging (b = 0, 1000 sec/mm2). The corresponding nCBV and ADC maps for the newly visible, entirely enhancing lesions were calculated after the completion of CCRT with TMZ. Two observers independently measured the histogram parameters of the nCBV and ADC maps. The histogram parameters between the true progression group (n = 10) and the pseudoprogression group (n = 10) were compared by use of an unpaired Student's t test and subsequent multivariable stepwise logistic regression analysis to determine the best predictors for the differential diagnosis between the two groups. Receiver operating characteristic analysis was employed to determine the best cutoff values for the histogram parameters that proved to be significant predictors for differentiating true progression from pseudoprogression. Intraclass correlation coefficient was used to determine the level of inter-observer reliability for the histogram parameters.
Results
The 5th percentile value (C5) of the cumulative ADC histograms was a significant predictor for the differential diagnosis between true progression and pseudoprogression (p = 0.044 for observer 1; p = 0.011 for observer 2). Optimal cutoff values of 892 × 10-6 mm2/sec for observer 1 and 907 × 10-6 mm2/sec for observer 2 could help differentiate between the two groups with a sensitivity of 90% and 80%, respectively, a specificity of 90% and 80%, respectively, and an area under the curve of 0.880 and 0.840, respectively. There was no other significant differentiating parameter on the nCBV histograms. Inter-observer reliability was excellent or good for all histogram parameters (intraclass correlation coefficient range: 0.70-0.99).
Conclusion
The C5 of the cumulative ADC histogram can be a promising parameter for the differentiation of true progression from pseudoprogression of newly visible, entirely enhancing lesions after CCRT with TMZ for glioblastomas.
doi:10.3348/kjr.2013.14.4.662
PMCID: PMC3725362  PMID: 23901325
Apparent diffusion coefficient; Cerebral blood volume; Glioblastoma multiforme; Histogram analysis; Pseudoprogression
20.  Effect of TiO2 nanoparticle-accumulated bilayer photoelectrode and condenser lens-assisted solar concentrator on light harvesting in dye-sensitized solar cells 
Nanoscale Research Letters  2013;8(1):283.
TiO2 nanoparticles (NPs) with a size of 240 nm (T240), used as a light-scattering layer, were applied on 25-nm-sized TiO2 NPs (T25) that were used as a dye-absorbing layer in the photoelectrodes of dye-sensitized solar cells (DSSCs). In addition, the incident light was concentrated via a condenser lens, and the effect of light concentration on the capacity of the light-scattering layer was systematically investigated. At the optimized focal length of the condenser lens, T25/T240 double layer (DL)-based DSSCs with the photoactive area of 0.36 cm2 were found to have the short circuit current (Isc) of 11.92 mA, the open circuit voltage (Voc) of 0.74 V, and power conversion efficiency (PCE) of approximately 4.11%, which is significantly improved when they were compared to the T25 single layer (SL)-based DSSCs without using a solar concentrator (the corresponding values were the Isc of 2.53 mA, the Voc of 0.69, and the PCE of 3.57%). Thus, the use of the optimized light harvesting structure in the photoelectrodes of DSSCs in conjunction with light concentration was found to significantly enhance the power output of DSSCs.
doi:10.1186/1556-276X-8-283
PMCID: PMC3683335  PMID: 23758633
Dye-sensitized solar cell; Solar concentrator; Plano-convex lens; Focal length; Light-scattering layer
21.  Thyroid Nodule with Benign Cytology: Is Clinical Follow-Up Enough? 
PLoS ONE  2013;8(5):e63834.
Objective
In this multicenter study, we investigated the management algorithm for thyroid nodules with benign cytology using US features from data collected from 7 institutions.
Materials and Methods
The institutional review board approved this retrospective study. Data on 700 focal thyroid nodules in 673 consecutive patients were collected from 7 university-affiliated hospitals. This study included nodules that were diagnosed as benign at initial cytologic evaluation and that underwent pathologic or follow-up study. The risk of malignancy was compared according to the US assessments of each institution as well as looking at all the nodules together as a whole.
Results
Of the 700 nodules, 688 (98.3%) were benign and 12 (1.7%) were malignant. If initial cytologic results were benign, the likelihood of the nodule actually being malignant was from 1 to 3%, varying by institution. The likelihood of a cytologically benign nodule with positive US being malignant (4.7%, 8/169) was higher than that of one without positive US (0.8%, 4/531) (P = .002).
Conclusion
Based on our multicenter study, repeat FNA should be performed in thyroid nodules with initial benign cytology showing suspicious US features in order to decrease the number of false negative cases.
doi:10.1371/journal.pone.0063834
PMCID: PMC3663808  PMID: 23717495
22.  Gliomas: Application of Cumulative Histogram Analysis of Normalized Cerebral Blood Volume on 3 T MRI to Tumor Grading 
PLoS ONE  2013;8(5):e63462.
Background
Glioma grading assumes significant importance in that low- and high-grade gliomas display different prognoses and are treated with dissimilar therapeutic strategies. The objective of our study was to retrospectively assess the usefulness of a cumulative normalized cerebral blood volume (nCBV) histogram for glioma grading based on 3 T MRI.
Methods
From February 2010 to April 2012, 63 patients with astrocytic tumors underwent 3 T MRI with dynamic susceptibility contrast perfusion-weighted imaging. Regions of interest containing the entire tumor volume were drawn on every section of the co-registered relative CBV (rCBV) maps and T2-weighted images. The percentile values from the cumulative nCBV histograms and the other histogram parameters were correlated with tumor grades. Cochran’s Q test and the McNemar test were used to compare the diagnostic accuracies of the histogram parameters after the receiver operating characteristic curve analysis. Using the parameter offering the highest diagnostic accuracy, a validation process was performed with an independent test set of nine patients.
Results
The 99th percentile of the cumulative nCBV histogram (nCBV C99), mean and peak height differed significantly between low- and high-grade gliomas (P = <0.001, 0.014 and <0.001, respectively) and between grade III and IV gliomas (P = <0.001, 0.001 and <0.001, respectively). The diagnostic accuracy of nCBV C99 was significantly higher than that of the mean nCBV (P = 0.016) in distinguishing high- from low-grade gliomas and was comparable to that of the peak height (P = 1.000). Validation using the two cutoff values of nCBV C99 achieved a diagnostic accuracy of 66.7% (6/9) for the separation of all three glioma grades.
Conclusion
Cumulative histogram analysis of nCBV using 3 T MRI can be a useful method for preoperative glioma grading. The nCBV C99 value is helpful in distinguishing high- from low-grade gliomas and grade IV from III gliomas.
doi:10.1371/journal.pone.0063462
PMCID: PMC3660395  PMID: 23704910
23.  Cholesterol Depletion in Cell Membranes of Human Airway Epithelial Cells Suppresses MUC5AC Gene Expression 
Yonsei Medical Journal  2013;54(3):679-685.
Purpose
If cholesterol in the cell membrane is depleted by treating cells with methyl-β-cyclodextrin (MβCD), the activities of transmembrane receptors are altered in a cell-specific and/or receptor-specific manner. The proinflammatory cytokines, IL-1β is potent inducers of MUC5AC mRNA and protein synthesis in human airway epithelial cells. Cells activated by IL-1β showed increased phosphorylation of extracellular signal regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). Thus, we investigated the effects of cholesterol depletion on the expression of MUC5AC in human airway epithelial cells and whether these alterations to MUC5AC expression were related to MAPK activity.
Materials and Methods
After NCI-H292 cells were pretreated with 1% MβCD before adding IL-1β for 24 hours, MUC5AC mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and real time-PCR. Cholesterol depletion by MβCD was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK and p38 MAPK, was analyzed by western blot.
Results
Cholesterol in the cell membrane was significantly depleted by treatment with MβCD on cells. IL-1β-induced MUC5AC mRNA expression was decreased by MβCD and this decrease occurred IL-1-receptor-specifically. Moreover, we have shown that MβCD suppressed the activation of ERK1/2 and p38 MAPK in cells activated with IL-1β. This result suggests that MβCD-mediated suppression of IL-1β-induced MUC5AC mRNA operated via the ERK- and p38 MAPK-dependent pathway.
Conclusion
Cholesterol depletion in NCI-H292 cell membrane may be considered an anti-hypersecretory method since it effectively inhibits mucus secretion of respiratory epithelial cells.
doi:10.3349/ymj.2013.54.3.679
PMCID: PMC3635649  PMID: 23549814
Cholesterol; cell membrane; cultured cells; mucins; MAP kinases
24.  Actin-propelled Invasive Membrane Protrusions Promote Fusogenic Protein Engagement During Cell-Cell Fusion 
Science (New York, N.Y.)  2013;340(6130):359-363.
Cell-cell fusion is critical for the conception, development and physiology of multicellular organisms. Although cellular fusogenic proteins and the actin cytoskeleton are implicated in cell-cell fusion, whether and how they coordinate to promote plasma membrane fusion remain unclear. Here, we reconstituted a high-efficiency, inducible cell-fusion culture system in the normally non-fusing Drosophila S2R+ cells. Both fusogenic proteins and actin cytoskeletal rearrangements were necessary for cell fusion, and, in combination, were sufficient to impart fusion competence. Localized actin polymerization triggered by specific cell-cell or cell-matrix adhesion molecules propelled invasive cell membrane protrusions, which, in turn, promoted fusogenic protein engagement and plasma membrane fusion. This de novo cell-fusion culture system reveals a general role for actin-propelled invasive membrane protrusions in driving fusogenic protein engagement during cell-cell fusion.
doi:10.1126/science.1234781
PMCID: PMC3631436  PMID: 23470732

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