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2.  Biochemical characterization of a SET and transposase fusion protein, Metnase (SETMAR) for its DNA binding and DNA cleavage activity 
Biochemistry  2007;46(40):11369-11376.
Metnase (SETMAR) is a SET and transposase fusion protein that promotes in vivo end joining activity and mediates genomic integration of foreign DNA. Recent studies showed that Metnase retained most of the transposase activities, including 5’-terminal inverted repeat (TIR)-specific binding and assembly of paired end complex, and cleavage of the 5’-end of the TIR element. Here we show that R432 within the helix-turn-helix motif is critical for sequence-specific recognition, as the mutation R432A abolishes its TIR-specific DNA binding activity.Metnase possesses a unique DNA nicking and/or endonuclease activity that mediates cleavage of duplex DNA in the absence of the TIR sequence. While the HTH motif is essential for the Metnase-TIR interaction, it is not required for its DNA cleavage activity. The DDE-like motif is crucial for its DNA cleavage action as a point mutation at this motif (D483A) abolished its DNA cleavage activity. Together, our results suggest that Metnase’s DNA cleavage activity, unlike other eukaryotic transposase, is not coupled to its sequence-specific DNA binding.
PMCID: PMC3374406  PMID: 17877369
Metnase; SETMAR; transposase; DNA binding; DNA cleavage; helix- turn-helix (HTH) motif; terminal-inverted repeats (TIR); DDE motif
3.  Role of Atypical Pathogens and the Antibiotic Prescription Pattern in Acute Bronchitis: A Multicenter Study in Korea 
Journal of Korean Medical Science  2015;30(10):1446-1452.
The role of atypical bacteria and the effect of antibiotic treatments in acute bronchitis are still not clear. This study was conducted at 22 hospitals (17 primary care clinics and 5 university hospitals) in Korea. Outpatients (aged ≥ 18 yr) who had an acute illness with a new cough and sputum (≤ 30 days) were enrolled in 2013. Multiplex real-time polymerase chain reaction (RT-PCR) was used to detect five atypical bacteria. A total of 435 patients were diagnosed as having acute bronchitis (vs. probable pneumonia, n = 75), and 1.8% (n = 8) were positive for atypical pathogens (Bordetella pertussis, n = 3; B. parapertussis, n = 0; Mycoplasma pneumoniae, n = 1; Chlamydophila pneumoniae, n = 3; Legionella pneumophila, n = 1). Among clinical symptoms and signs, only post-tussive vomiting was more frequent in patients with atypical pathogens than those without (P = 0.024). In all, 72.2% of the enrolled patients received antibiotic treatment at their first visits, and β-lactams (29.4%) and quinolones (20.5%) were the most commonly prescribed agents. In conclusion, our study demonstrates that the incidence of atypical pathogens is low in patients with acute bronchitis, and the rate of antibiotic prescriptions is high.
Graphical Abstract
PMCID: PMC4575933  PMID: 26425041
Acute Bronchitis; Antibiotics; Atypical Pathogens; Korea
4.  The Effects of an Extract of Atractylodes Japonica Rhizome, SKI3246 on Gastrointestinal Motility in Guinea Pigs 
There are limited therapeutic options available for irritable bowel syndrome with diarrhea (IBS-D). We tested the effects of Atractylodes japonica rhizome, a perennial plant native to North Asia, on both upper and lower gastrointestinal (GI) motility in guinea pigs.
The extract of A. japonica rhizome was administered orally at different doses to test its effects on upper GI motility as determined from charcoal transit in native guinea pigs and in guinea pigs pretreated with thyrotropin-releasing hormone or mustard oil. Regarding its effect on lower GI motility, the removed guinea pig colon was suspended in a chamber containing Krebs-Henseleit solution and the transit time of artificial feces was measured with various dilutions of the extract. As for in vivo assay, weight and number of fecal pellets expelled were determined under the same drug preparation used in upper GI motility experiment.
The extract of A. japonica rhizome had no significant effect on upper GI motility in either normal or altered physiological states. However, the extract increased colonic transit time in the in vitro model. In the fecal expulsion study, the cumulative weight and number of pellets did not differ significantly between the control group and groups treated with the extracts. In the animals pretreated in vivo with thyrotropin-releasing hormone, however, the weight and number of fecal pellets were significantly decreased in animals treated with 300 mg/kg and 600 mg/kg doses of extract.
Our findings suggest that the extract of A. japonica rhizome can be a potential agent for IBS-D.
PMCID: PMC4496911  PMID: 26130631
Atractylodes japonica; Diarrhea; Gastrointestinal motility; Guinea pigs; Irritable bowel syndrome
5.  Clinical and Pathological Characteristics of Hard Nodules Resistant to Morcellation During Holmium Laser Enucleation of the Prostate 
To identify the clinical and pathological characteristics of hard nodules resistant to morcellation (HNRM) during holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia (BPH).
Between July 2008 and October 2011, 246 patients underwent HoLEP for symptomatic BPH. The first 30 patients were excluded from the analysis due to the learning curve of the procedure. The remaining patients were divided into HNRM (n=29) and non-HNRM groups (n=187), and comparative analysis of the clinical parameters of the two groups was performed. International prostate symptom score analysis and urodynamic studies were performed preoperatively. Histological analysis was performed after hematoxylin and eosin staining and Masson trichrome staining of the HNRM specimens.
Twenty-nine patients (13.4%) had HNRM. The patients in the HNRM group had significantly higher proportions of advanced age (≥65 years, P=0.029), total prostate volume ≥65 mL (P<0.001), transition zone volume ≥35 mL (P<0.001), serum prostate-specific antigen levels ≥10 ng/mL (P=0.007), and functional urethral length ≥70 mm (P=0.009); larger enucleation weight (P<0.001); longer operation (P=0.001), enucleation (P=0.042), and morcellation times (P<0.001); and higher enucleation ratio (P=0.028) and enucleation efficacy (P=0.001). After adjusting for confounding factors, multivariate logistic regression analysis revealed that age ≥65 years and total prostate volume ≥65 mL were independent risk factors for HNRM. Pathological examination did not reveal any malignant cells, with mainly dense fibrous tissue found in the HNRM.
HNRM can make morcellation cumbersome and time-consuming, and older patients with larger prostates have a higher incidence of HNRM. However, the histopathology of HNRM revealed mainly fibrotic tissue.
PMCID: PMC4490320  PMID: 26126438
Laser Therapy; Prostate; Prostatic Hyperplasia; Transurethral Resection of Prostate
6.  Comparative analysis of benign prostatic hyperplasia management by urologists and nonurologists: A Korean nationwide health insurance database study 
Korean Journal of Urology  2015;56(3):233-239.
To compare the current management of benign prostatic hyperplasia (BPH) by urologists and nonurologists by use of Korean nationwide health insurance data.
Materials and Methods
We obtained patient data from the national health insurance system. New patients diagnosed with BPH in 2009 were divided into two groups depending on whether they were diagnosed by a urologist (U group) or by a nonurologist (NU group).
A total of 390,767 individuals were newly diagnosed with BPH in 2009. Of these, 240,907 patients (61.7%) were in the U group and 149,860 patients (38.3%) were in the NU group. The rate of all initial evaluation tests, except serum creatinine, was significantly lower in the NU group. The initial prescription rate was higher in the U group, whereas the prescription period was longer in the NU group. Regarding the initial drugs prescribed, the use of alpha-blockers was common in both groups. However, the U group was prescribed combination therapy of an alpha-blocker and 5-alpha-reductase inhibitor as the second choice, whereas the NU group received monotherapy with a 5-alpha-reductase inhibitor. During the 1-year follow-up, the incidence of surgery was significantly different between the U group and the NU group.
There are distinct differences in the diagnosis and treatment of BPH by urologists and nonurologists in Korea. These differences may have adverse consequences for BPH patients. Urological societies should take a leadership role in the management of BPH and play an educational role for nonurologists as well as urologists.
PMCID: PMC4355435  PMID: 25763128
Epidemiology; Insurance claim review; Prostatic hyperplasia
7.  Beneficial effects of ethanol extracts of Red Liriope platyphylla on vascular dysfunction in the aorta of spontaneously hypertensive rats 
Laboratory Animal Research  2015;31(1):13-23.
Some biological effects of Red Liriope platyphylla (RLP) on various chronic diseases including Alzheimer's disease, diabetes and obesity were suggested after a report of the production from Liriope platyphylla (L. platyphylla, LP) roots using a steaming process. To examine the beneficial effects of ethanol extracts RLP (EEtRLP) on the vascular dysfunction of hypertension, alterations in key factors related to vascular regulation and antioxidant conditions were investigated in spontaneously hypertensive rats (SHR) after EEtRLP treatment for 2 weeks. High levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were detected in 500 or 1,000 mg/mL EEtRLP. Although no significant improvement of systolic blood pressure or aortic wall thickness were observed in the EEtRLP treated group, the expression level of angiotensin converting enzyme (ACE) and ACE2 increased significantly after EEtRLP treatment. Moreover, the concentration of aldosterone and K ion in serum rapidly recovered in the EEtRLP treated group relative to the vehicle treated group. Furthermore, the endothelial nitric oxide synthase (eNOS) expression and superoxide dismutase (SOD) activity were significantly increased in the EEtRLP treated group relative to the vehicle treated group, while the level of malondialdehyde (MDA) and NOx in the serum of the same group were recovered to the level of Wistar Kyoto (WKY) rats. Overall, the results presented herein provide novel evidence that EEtRLP treatment may improve vascular dysfunction in the aorta of the SHR through up regulation of the antioxidant state and down regulation of aldosterone and K ion concentration. These results also suggest that EEtRLP may be a potential candidate for treatment of various chronic diseases showing vascular dysfunction.
PMCID: PMC4371473  PMID: 25806079
Red Liriope platyphylla; DPPH; ACE; aldosterone; eNOS; SOD
8.  The Association between Serum Uric Acid Level and Incidence of Metabolic Syndrome according to Menopausal Status in Korean Women 
Journal of Menopausal Medicine  2014;20(3):126-132.
The aim of this study is to investigate the association between serum uric acid level and metabolic syndrome according to menopausal status in Korean women.
A total of 2,241 women who visited to the health promotion center at Pusan National University Hospital from 2010 to 2014 were included in this cross-sectional study. Self-report questionnaires and interviews with healthcare providers were used to assess disease history, medication history, menstrual history and body size measuring. Anthropometric measurements and laboratory results were compared as presence of metabolic syndrome and menopausal status by student-t test. Logistic regression analysis was performed between presence of metabolic syndrome and presumable predictive factors, such as age, menopause and serum uric acid.
The prevalence rate of metabolic syndrome were 7.45% (63/846) in pre-menopausal group and 23.87% (333/1395) in menopausal group. Serum uric acid level was higher in menopausal women than premenopausal women (4.6 ± 1.1 vs. 4.3 ± 0.9. P = 0.000). And, its concentration was also higher in metabolic syndrome than normal women regarding of menopausal statue (premenopause 4.7 ± 1.1 vs. 4.2 ± 0.8, P = 0.001, menopause 4.9 ± 1.3 vs. 4.5 ± 1.0, P = 0.000). Multiple logistic regression analysis showed serum uric acid and age have relationship with metabolic syndrome (OR: 1.453, 95% confidence interval [CI]: 1.074-1.111, P = 0.000; OR: 1.092, 95% CI: 1.305-1.619, P = 0.000).
We could find out some potential of uric acid as predictive factor for metabolic syndrome in premenopausal and menopausal group. Further investigation is required to clarify the relationship between serum uric acid, menopause and metabolic syndrome.
PMCID: PMC4286657  PMID: 25580424
Menopause; Metabolic syndrome X; Uric acid
9.  Preoperative CT Voiding Cystourethrography Using 16-Multidetector CT in Female Urethral Diverticulum 
PLoS ONE  2014;9(9):e107448.
To evaluate the clinical usefulness of preoperative CT voiding cystourethrography (CT-VCUG) using 16-multidetector computed tomography for female urethral diverticula.
Materials and Methods
Preoperative CT-VCUG was performed in 15 consecutive patients who underwent urethral diverticulectomy from May 2004 to December 2012. The result of preoperative cystourethroscopy and surgical findings were recorded by a single surgeon and CT-VCUG findings including the location of osita were retrospectively reviewed by another urologist who was blinded to the surgical finding. The location of the ostium detected on CT-VCUG was compared descriptively with the intraoperative surgical and preoperative cystourethroscopic findings.
A total of 14 consecutive patients who underwent preoperative CT-VCUG and urethral diverticulectomy were included in the analysis. Ostia were detected on CT-VCUG in all cases, whereas ostia were identified in 10 patients (71.4%) by cystourethroscopy. Ostia were located between the 4 and 8 o’clock direction. Mean distance from the bladder neck to the ostium was 24.2 mm. Circumferential and horseshoe shaped diverticula were observed in 6 and 4 patients, respectively. The surgical findings correlated well with the CT findings.
Preoperative CT-VCUG can be useful in identifying the ostia of urethral diverticula in patients scheduled for urethral diverticulectomy and can provide structural information, useful to establish surgical strategy.
PMCID: PMC4162593  PMID: 25216189
10.  Poor Glycemic Control of Diabetes Mellitus Is Associated with Higher Risk of Prostate Cancer Detection in a Biopsy Population 
PLoS ONE  2014;9(9):e104789.
To evaluate the impact of glycemic control of diabetes mellitus (DM) on prostate cancer detection in a biopsy population.
Patients and Methods
We retrospectively reviewed the records of 1,368 men who underwent prostate biopsy at our institution. We divided our biopsy population into three groups according to their history of DM, and their Hemoglobin A1c (HbA1c) level: a no-DM (DM−) group; a good glycemic control (DM+GC) group (HbA1c <6.5%); and a poor glycemic control (DM+PC) group (HbA1c ≥6.5%). For sub-analyses, the DM+PC group was divided into a moderately poor glycemic control (DM+mPC) group (6.5≤ HbA1c <7.5%) and a severely poor glycemic control (DM+sPC) group (HbA1c ≥7.5%).
Among 1,368 men, 338 (24.7%) had a history of DM, and 393 (28.7%) had a positive biopsy. There was a significant difference in prostatic specific antigen density (PSAD) (P = 0.037) and the frequency of abnormal DRE findings (P = 0.031) among three groups. The occurrence rate of overall prostate cancer (P<0.001) and high-grade prostate cancer (P = 0.016) also presented with a significantly difference. In the multivariate analysis, the DM+PC group was significantly associated with a higher rate of overall prostate cancer detection in biopsy subjects compared to the DM− group (OR = 2.313, P = 0.001) but the DM+PC group was not associated with a higher rate of high-grade (Gleason score ≥7) diseases detected during the biopsy (OR = 1.297, P = 0.376). However, in subgroup analysis, DM+sPC group was significantly related to a higher risk of high-grade diseases compared to the DM− group (OR = 2.446, P = 0.048).
Poor glycemic control of DM was associated with a higher risk of prostate cancer detection, including high-grade disease, in the biopsy population.
PMCID: PMC4157745  PMID: 25198675
11.  Impact of Squamous and Glandular Differentiation on Oncologic Outcomes in Upper and Lower Tract Urothelial Carcinoma 
PLoS ONE  2014;9(9):e107027.
To investigate the prognostic significance of squamous and/or glandular differentiation in urothelial carcinoma (UC).
Materials and Methods
Among 800 consecutive patients who underwent radical cystectomy or nephroureterectomy at our institution from January 1990 to December 2010, 696 patients were included for the analysis. Clinicopathologic variables were compared according to the presence of squamous and/or glandular differentiation and the tumor location.
A total of 51 (7.3%) patients had squamous and/or glandular differentiation. Patients with squamous and/or glandular differentiation had higher pathological T stage (p<0.001) and grade (p<0.001) than those with pure form of UC. After the median follow-up of 55.2 months, 84 (24.6%) and 82 (23.1%) died of upper urinary tract UC and UC of bladder, respectively. Patients with squamous and/or glandular differentiation in upper urinary tract UC showed poorer cancer-specific survival (CSS) (p<0.001) and overall survival (OS) (p<0.001) than those with pure form in upper urinary tract UC (p<0.001), but not in UC of bladder (p = 0.178 for CSS and p = 0.172 for OS). On multivariate Cox regression analysis, squamous and/or glandular differentiation was an independent predictor of CSS (hazard ratio [HR] 1.76; 95% confidence interval [CI] 1.08–2.85, p = 0.023), but it was not associated with OS (HR 1.52; 95% CI 1.00–2.32, p = 0.051).
The presence of variant histology could be associated with poorer survival outcome in patients with UC. Squamous and/or glandular differentiation is associated with features of biologically aggressive disease and an independent predictor of CSS.
PMCID: PMC4156382  PMID: 25191845
12.  Vitrification solution without sucrose for cryopreservation in mouse blastocysts 
This study was designed to investigate the survival rate of vitrified mouse blastocysts depending on the presence or absence of sucrose in vitrification solution.
Mouse two-cell embryos were collected and cultured to blastocysts. Two vitrification solutions were prepared. The control solution was composed of 25% glycerol, 25% ethylene glycol, and 0.5 M sucrose (G25E250.5S) containing 2.5 mL glycerol, 2.5 mL ethylene glycol, 2 mL SSS, and 0.855 g sucrose in 5 mL PB1. The experimental solution was composed of 25% glycerol and 25% ethylene glycol (G25E25) and contained 2.5 mL glycerol and 2.5 mL ethylene glycol in 5 mL PB1. Artificial shrinkage was conducted by aspirating the blastocoelic fluid using an ICSI pipette. To examine the effect of sucrose in the vitrification solution on the survival rate of mouse blastocysts, the shrunken-equilibrated blastocysts were rehydrated or vitrified after being exposed to one of the two vitrification solutions. After exposure and the vitrification-thawing process, the re-expansion rate and hatching rate were evaluated after 6 hours of in vitro culture.
The re-expansion rate of mouse blastocysts exposed to vitrification solution with and without sucrose were not different in the experimental solution (without sucrose) (98%) and the control solution (with sucrose) (92%) (p>0.05). The hatching rate was higher in the experimental solution (95%) than in the control solution (88%), but did not differ across two treatments (p>0.05). The re-expansion rate of mouse blastocysts vitrified in the control solution was 92% and 94%, respectively (p>0.05), and the hatching rate was higher in the experimental solution (90%) than in the control solution (74%) (p<0.05).
Sucrose need not be added in vitrification solution for freezing of artificially shrunken mouse blastocysts.
PMCID: PMC4192451  PMID: 25309855
Artificial shrinkage; Blastocyst; Sucrose; Vitrification
13.  Toxicity of fermented soybean product (cheonggukjang) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on liver and kidney of ICR mice 
Laboratory Animal Research  2014;30(2):54-63.
To investigate the toxic effects of cheonggukjang (CKJ) manufactured using mixed cultures of Bacillus subtilis MC31 and Lactobacillus sakei 383 on the liver and kidney of ICR mice, an alteration on the related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed after oral administration at dosage of 25, 50 and 100 mg/kg body weight/day of CKJ for 14 days. Any significant toxicity was not observed on the body and organ weight, clinical phenotypes, urine parameters and mortality in the CKJ-treated group compared with the vehicle-treated group. Also, liver toxicity analysis revealed no significant increase in alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) or lactate dehydrogenase (LDH) in response to CKJ. Additionally, the specific pathological features induced by most toxic compounds were not observed upon liver histological analysis. Furthermore, kidney toxicological analysis revealed that blood urea nitrogen (BUN) and the serum creatinine (Cr) levels and pathological features on histological sections did not differ significantly between the vehicle- and CKJ-treated groups. Overall, these results suggest that CKJ does not induce any specific toxicity in liver and kidney organs of ICR at dose of 100 mg/kg body weight/day as no observed adverse effect level (NOAEL).
PMCID: PMC4079832  PMID: 24999359
Bacillus subtilis MC31; cheonggukjang; kidney; Lactobacillus sakei 383; liver; toxic effect
14.  The Nephrometry Score: Is It Effective for Predicting Perioperative Outcome During Robot-Assisted Partial Nephrectomy? 
Korean Journal of Urology  2014;55(4):254-259.
Robot-assisted partial nephrectomy (RPN) has emerged as an alternative treatment for the management of small renal masses. This study was designed to investigate parameters that predict perioperative outcomes during RPN.
Materials and Methods
We retrospectively reviewed the medical records of 113 patients who underwent RPN between September 2008 and May 2012 at the Seoul National University Bundang Hospital. Clinical parameters, including warm ischemia time (WIT), estimated blood loss (EBL), and R.E.N.A.L and PADUA scores, were evaluated to predict perioperative outcomes.
Of the 113 patients, 81 were men and 32 were women. The patients' mean age was 53.5 years, and their mean body mass index was 22.3 kg/m2. Age, gender, and mass laterality had no effect on perioperative complications, WIT, or EBL. Univariate analysis revealed that a distance between the tumor and the collecting system of ≤4 mm or a renal mass size of >4 cm were associated with adverse profiles of complications, WIT, and EBL. However, multivariate analysis showed no association between the predictive parameters and tumor complexity as assessed by nephrometry scores. Tumor size of >4 cm increased the risk of blood loss >300 mL (odds ratio [OR], 3.5; 95% confidence interval [CI],; p=0.016). A distance between the tumor and the collecting system of ≤4 mm was associated with increased risk of WIT exceeding 20 minutes (OR, 2.8; 95% CI,; p=0.012).
Tumor size and proximity of the mass to the collecting system showed significant associations with EBL and WIT, respectively, during RPN. The R.E.N.A.L and PADUA nephrometry scoring systems did not predict perioperative outcomes.
PMCID: PMC3988436  PMID: 24741414
Nephrectomy; Renal cell carcinoma; Robotics; Surgical blood loss; Warm ischemia
15.  Chk1 phosphorylation of Metnase/SETMAR at Ser495 enhances DNA repair but decreases replication fork restart 
Oncogene  2012;31(38):4245-4254.
Chk1 both arrests replication forks and enhances repair of DNA damage by phosphorylation of downstream effectors. While there has been a distinguished effort in identifying effectors of Chk1 activity, there are still mechanisms of its activities that are yet to be identified. Metnase/SETMAR is a SET and transposase domain protein that promotes both DNA double strand break (DSB) repair and re-start of stalled replication forks. In this study, we show that Metnase is phosphorylated only on Ser495 (S495) in vivo in response to DNA damage by ionizing radiation. Chk1 is the major mediator of this phosphorylation event. We had previously shown that wild type (wt) Metnase associates with chromatin near an artificially induced DSB in an engineered cell system. However, an S495A Metnase mutant, which could not be phosphorylated by Chk1, had a defect in its DSB chromatin association. The S495A mutant also failed to support repair of an induced DSB when compared with wild type (wt) Metnase. Interestingly, the S495A mutant demonstrated increased restart of stalled replication forks compared to wt Metnase. Thus, S495 phosphorylation of Metnase differentiates between its two main functions, enhancing DSB repair and repressing replication fork restart. In summary, these data lend insight into the mechanism by which Chk1 enhances repair of DNA damage while at the same time repressing stalled replication fork restart.
PMCID: PMC3963179  PMID: 22231448
Chk1; Metnase; SETMAR; phosphorylation; DNA repair; replication fork; transposase; ionizing radiation
16.  Metabolomics approach to serum biomarker for loperamide-induced constipation in SD rats 
Laboratory Animal Research  2014;30(1):35-43.
Loperamide has long been known as an opioid-receptor agonist useful as a drug for treatment of diarrhea resulting from gastroenteritis or inflammatory bowel disease as well as to induce constipation. To determine and characterize putative biomarkers that can predict constipation induced by loperamide treatment, alteration of endogenous metabolites was measured in the serum of Sprague Dawley (SD) rats treated with loperamide for 3 days using 1H nuclear magnetic resonance (1H NMR) spectral data. The amounts and weights of stool and urine excretion were significantly lower in the loperamide-treated group than the No-treated group, while the thickness of the villus, crypt layer, and muscle layer was decreased in the transverse colon of the same group. The concentrations of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatinine (Cr) were also slightly changed in the loperamide-treated group, although most of the serum components were maintained at a constant level. Furthermore, pattern recognition of endogenous metabolites showed completely separate clustering of the serum analysis parameters between the No-treated group and loperamide-treated group. Among 35 endogenous metabolites, four amino acids (alanine, glutamate, glutamine and glycine) and six endogenous metabolites (acetate, glucose, glycerol, lactate, succinate and taurine) were dramatically decreased in loperamide-treated SD rats. These results provide the first data pertaining to metabolic changes in SD rats with loperamide-induced constipation. Additionally, these findings correlate the changes in 10 metabolites with constipation.
PMCID: PMC3973809  PMID: 24707303
loperamide; constipation; metabolomics; serum; transverse colon
17.  Impact of critical pathway implementation on hospital stay and costs in patients undergoing pancreaticoduodenectomy 
Recent studies have shown that pancreaticoduodenectomy (PD) can be performed quite safely. Critical pathway (CP) has been one of the key tools used to achieve excellent outcomes in high-quality, high-volume centers. This study was designed to evaluate the impact of CP implementation for PD patients.
The important components of CP for PD patients include the early start of an oral diet and removal of the abdomen drain following follow-up computed tomography, with the intention of shortening the postoperative hospital stay. The study group (CP group) comprised of 88 patients who underwent pylorus-preserving or classical PD from January 2009 to December 2010. The control group (pre-CP group) was 185 patients who underwent PD between January 2005 and December 2008.
The two groups did not show significant differences in demographic profiles and the primary diagnosis. The incidences of overall postoperative complications such as delayed gastric emptying, fistula, and hemorrhage were similar or decreased in the CP group (54% vs. 40.9%). The incidence of clinically significant complications also showed a similar rate (5.4% vs. 4.5%) between the two groups. The nutritional status at discharge and re-admission rates were not different. The CP group showed a significantly shorter postoperative hospital stay (20.2±9.2 days vs. 14.9±5.1 days, p<0.001) and the total medical costs were also significantly reduced, by 15% (p<0.001).
The results of this study indicated that the implementation of CP for PD patients can decrease the length of hospital stay and reduce medial costs, with maintenance or improvement of patient outcomes. Further investigation is necessary to validate the actual impact of CP for PD through multi-center high-volume studies.
PMCID: PMC4492334  PMID: 26155241
Critical pathway; Pancreaticoduodenectomy; Hospital stay; Complication; Medical cost
18.  Inhibition of Hepatitis C Virus (HCV) Replication by Specific RNA Aptamers against HCV NS5B RNA Replicase 
Journal of Virology  2013;87(12):7064-7074.
This study identified specific and avid RNA aptamers consisting of 2′-hydroxyl- or 2′-fluoropyrimidines against hepatitis C virus (HCV) NS5B replicase, an enzyme that is essential for HCV replication. These aptamers acted as potent decoys to competitively impede replicase-catalyzed RNA synthesis activity. Cytoplasmic expression of the 2′-hydroxyl aptamer efficiently inhibited HCV replicon replication in human liver cells through specific interaction with, and sequestration of, the target protein without either off-target effects or escape mutant generation. A selected 2′-fluoro aptamer could be truncated to a chemically manufacturable length of 29 nucleotides (nt), with increase in the affinity to HCV NS5B. Noticeably, transfection of the truncated aptamer efficiently suppressed HCV replication in cells without escape mutant appearance. The aptamer was further modified through conjugation of a cholesterol or galactose-polyethylene glycol ligand for in vivo availability and liver-specific delivery. The conjugated aptamer efficiently entered cells and inhibited genotype 1b subgenomic and genotype 2a full-length HCV JFH-1 RNA replication without toxicity and innate immunity induction. Importantly, a therapeutically feasible amount of the conjugated aptamer was delivered in vivo to liver tissue in mice. Therefore, cytoplasmic expression of 2′-hydroxyl aptamer or direct administration of chemically synthesized and ligand-conjugated 2′-fluoro aptamer against HCV NS5B could be a potent anti-HCV approach.
PMCID: PMC3676086  PMID: 23596299
19.  Precautionary effects of Red Liriope platyphylla on NGF secretion and Aβ42 deposition under the preclinical stage of Alzheimer's disease in Tg2576 mice 
Laboratory Animal Research  2013;29(4):212-220.
Red Liriope platyphylla (RLP) has been manufactured from Liriope platyphylla (L. platyphylla, LP) roots using steaming process and investigated as a curative agent for treatment of diabetes, obesity and neurodegenerative disorders. To examine the precautionary effects of aqueous extract RLP (AEtRLP) on the preclinical stages of Alzheimer's Disease (AD), alterations of the key factors influencing AD were investigated in Tg2576 mice after AEtRLP7 treatment for 4 months. Aβ-42 peptides level was significantly decreased in the brain of AEtRLP7-treated Tg2576 mice compared to vehicle-treated Tg2576 mice, although significant differences on improving behavioral defects were not observed in the same group. The concentration of nerve growth factor (NGF) in serum was also higher in AEtRLP7-treated Tg2576 mice than vehicle-treated Tg2576 mice. However, the phosphorylation of TrkA and Erk among the downstream effectors of the high affinity NGF receptor was significantly lower in AEtRLP7-treated Tg2576 mice. A similar pattern was observed in the expression level of downstream effectors within low affinity NGF receptor. Overall, these results suggest that AEtRLP7 can contribute to preventing the production and deposition of Aβ-42 peptides during the early progression stage of AD in the brain of Tg2576 mice through increased NGF secretion.
PMCID: PMC3879340  PMID: 24396386
Red Liriope platyphylla; NGF; NGF signaling pathway; Aβ-42
20.  Aqueous extracts of Liriope platyphylla induced significant laxative effects on loperamide-induced constipation of SD rats 
Liriope platyphylla has long been reported as a therapeutic drug for treatment of various human chronic diseases including inflammation, diabetes, neurodegenerative disorders, obesity, and atopic dermatitis. To investigate the laxative effects of L. platyphylla, alterations in excretion parameters, histological structure, mucin secretion, and related protein levels were investigated in rats with loperamide (Lop)-induced constipation after treatment with aqueous extract of L. platyphylla (AEtLP).
Alterations on constipation phenotypes were measured in rats with Lop-induced constipation after treatment with AEtLP using excretion parameter analysis, histological analysis, RT-PCR, western blot and transmission electron microscope (TEM) analysis.
The amounts of stool and urine excretion were significantly higher in the Lop + AEtLP-treated group than in the Lop + vehicle-treated group, whereas food intake and water consumption were maintained at constant levels. AEtLP treatment also induced an increase in villus length, crypt layer, and muscle thickness in the constipation model. Total mucin secretion was higher in the Lop + AEtLP-treated group than in the Lop + vehicle-treated group, although mucin secretion per crypt was very similar among all groups. Furthermore, RT-PCR and western blot revealed a dramatic reduction of key factors level on the muscarinic acetylcholine receptors (mAChRs) signaling pathway in the Lop + AEtLP-treated group relative to the Lop + vehicle-treated group. Especially, the accumulation of lipid droplets in enterocytes of crypts following Lop treatment was improved to the level of the No-treated group in response to AEtLP treatment.
These results suggest that AEtLP improves constipation induced by Lop treatment through an increase in crypt layer and stimulation of lipid droplet secretions. These data are the first to show that the laxative effects of AEtLP are closely related to the down-regulation of mAchRs and their downstream signals.
PMCID: PMC4222752  PMID: 24274470
21.  Biocompatibility of a Novel Cyanoacrylate Based Tissue Adhesive: Cytotoxicity and Biochemical Property Evaluation 
PLoS ONE  2013;8(11):e79761.
Cyanoacrylate (CA) is most widely used as a medical and commercial tissue adhesive because of easier wound closure, good cosmetic results and little discomfort. But, CA-based tissue adhesives have some limitations including the release of cytotoxic chemicals during biodegradation. In previous study, we made prepolymerized allyl 2-CA (PACA) based tissue adhesive, resulting in longer chain structure. In this study, we investigated a biocompatibility of PACA as alternative tissue adhesive for medical application, comparing with that of Dermabond® as commercial tissue adhesive. The biocompatibility of PACA was evaluated for short-term (24 hr) and long-term (3 and 7 days) using conventional cytotoxicity (WST, neutral red, LIVE/DEAD and TUNEL) assays, hematoxylin-eosin (H&E) and Masson trichrome (MT) staining. Besides we examined the biochemical changes in cells and DNA induced by PACA and Dermabond® utilizing Raman spectroscopy which could observe the denaturation and conformational changes in protein, as well as disintegration of the DNA/RNA by cell death. In particular, we analyzed Raman spectrum using the multivariate statistical methods including principal component analysis (PCA) and support vector machine (SVM). As a result, PACA and Dermabond® tissue adhesive treated cells and tissues showed no difference of the cell viability values, histological analysis and Raman spectral intensity. Also, the classification analysis by means of PCA-SVM classifier could not discriminate the difference between the PACA and Dermabond® treated cells and DNA. Therefore we suggest that novel PACA might be useful as potential tissue adhesive with effective biocompatibility.
PMCID: PMC3838346  PMID: 24278173
22.  Amino acid substitutions in gyrA and parC associated with quinolone resistance in nalidixic acid-resistant Salmonella isolates 
Irish Veterinary Journal  2013;66(1):23.
This study was undertaken to identify and characterize amino acid substitutions in gyrA and parC related with quinolone resistance of 27 nalidixic acid-resistant (NaR) Salmonella isolates collected in poultry slaughterhouses in Korea. A total of 51 Salmonella isolates were detected from 44.8% (47/105) of the total samples from 15 poultry slaughterhouses examined, among which 27 (52.9%) NaR isolates were detected while ciprofloxacin (Cip) resistance was not present in the isolates. These 27 NaR isolates of DNA sequencing revealed that it contained three types of gyrA mutations in only D87 codon. Mutations in the D87 codon resulted in substitutions to G in most of the isolates, but D87Y and D87N exchanges were also detected. Although Cip resistance was absent, reduced susceptibility characterized by mutations in gyrA was apparent among Salmonella isolates from poultry slaughterhouses in Korea.
PMCID: PMC4225662  PMID: 24237626
gyrA; Nalidixic acid resistance; Salmonella
23.  A simple and rapid detection of tissue adhesive-induced biochemical changes in cells and DNA using Raman spectroscopy 
Biomedical Optics Express  2013;4(11):2673-2682.
We demonstrate a cytotoxicity evaluation of tissue adhesive using Raman spectroscopy. This method allows for quantitative, label-free, non-invasive and rapid monitoring of the biochemical changes of cells following tissue adhesive treatment. Here, we show the biochemical property changes in mouse fibroblast L929 cells and cellular DNA following tissue adhesive (Dermabond) treatment using Raman spectroscopy. The Raman band intensities were significantly decreased when the cells were treated with Dermabond as compared to control cells. These results suggest denaturation and conformational changes in proteins and degradation of DNA related to cell death. To support these conclusions, conventional cytotoxicity assays such as WST, LIVE/DEAD, and TUNEL were carried out, and the results were in agreement with the Raman results. Thus, Raman spectroscopy analysis not only distinguishes between viable and damaged cells, but can also be used for identification and quantification of a cytotoxicity of tissue adhesive, which based on the cellular biochemical and structural changes at a molecular level. Therefore, we suggest that this method could be used for cytotoxic evaluation of tissue adhesives by rapid and sensitive detection of cellular changes.
PMCID: PMC3829560  PMID: 24298425
(300.6450) Spectroscopy, Raman; (170.0170) Medical optics and biotechnology; (170.5660) Raman spectroscopy; (170.1530) Cell analysis
24.  pH-Sensitive Polymeric Micelle-based pH Probe for Detecting and Imaging Acidic Biological Environments 
Biomacromolecules  2012;13(9):2945-2951.
To overcome the limitations of monomeric pH probes for acidic tumor environments, this study designed a mixed micelle pH probe composed of polyethylene glycol (PEG)-b- poly(L-histidine) (PHis) and PEG-b-poly(L-lactic acid) (PLLA), which is well-known as an effective antitumor drug carrier. Unlike monomeric histidine and PHis derivatives, the mixed micelles can be structurally destabilized by changes in pH, leading to a better pH sensing system in nuclear magnetic resonance (NMR) techniques. The acidic pH-induced transformation of the mixed micelles allowed pH detection and pH mapping of 0.2–0.3 pH unit differences by pH-induced “on/off”-like sensing of NMR and magnetic resonance spectroscopy (MRS). The micellar pH probes sensed pH differences in non-biological phosphate buffer and biological buffers such as cell culture medium and rat whole blood. In addition, the pH-sensing ability of the mixed micelles was not compromised by loaded doxorubicin. In conclusion, PHis-based micelles could have potential as a tool to simultaneously treat and map the pH of solid tumors in vivo.
PMCID: PMC3438342  PMID: 22861824
pH imaging; poly(L-histidine); micelle pH probe; NMR; MRS
25.  Current Management of Urethral Stricture 
Korean Journal of Urology  2013;54(9):561-569.
The surgical treatment of urethral stricture diseases is continually evolving. Although various surgical techniques are available for the treatment of anterior urethral stricture, no one technique has been identified as the method of choice. This article provides a brief updated review of the surgical options for the management of different sites and different types of anterior urethral stricture. This review also covers present controversies in urethral reconstruction. Among the various procedures available for treating urethral stricture, one-stage buccal mucosal graft urethroplasty is currently widely used. The choice of technique for urethroplasty for an individual case largely depends on the expertise of the surgeon. Therefore, urologists working in this field should keep themselves updated on the numerous surgical techniques to deal with any condition of the urethra that might surface at the time of surgery.
PMCID: PMC3773584  PMID: 24044088
Urethra; Urethral stricture; Urethroplasty

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