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1.  A new histone deacetylase inhibitor improves liver fibrosis in BDL rats through suppression of hepatic stellate cells 
British Journal of Pharmacology  2014;171(21):4820-4830.
Background and Purpose
Activation of hepatic stellate cells (HSCs) is a crucial step in the pathogenesis of hepatic fibrosis. Histone deacetylase (HDAC) is an attractive target in liver fibrosis because it plays a key role in gene expression and cell differentiation. We have developed a HDAC inhibitor, N-hydroxy-7-(2-naphthylthio)heptanomide (HNHA), and investigated the anti-fibrotic activity of HNHA in vitro and in vivo.
Experimental Approach
We investigated the anti-fibrotic effect of HNHA on mouse and human HSC activation in vitro and in the liver of bile duct-ligated (BDL) rats in vivo using cell proliferation assays, cell cycle analysis, biochemical assay, immunohistochemistry and Western blots. Liver pathology was assessed with histochemical techniques.
Key Results
HNHA inhibited proliferation and arrested the cell cycle via p21 induction in HSCs. In addition, HNHA induced apoptosis of HSCs, which was correlated with reduced COX-2 expression, NF-κB activation and cell death signals. HNHA restored liver function and decreased the accumulation of extracellular matrix in the liver via suppression of HSC activation in BDL rats in vivo. HNHA administration also increased survival in BDL rats.
Conclusions and Implications
HNHA improved liver function, suppressed liver fibrosis and increased survival of BDL rats, accompanied by reduction of cell growth, activation and survival of HSCs. These findings show that HNHA may be a potent anti-fibrosis agent against hepatic fibrosis because of its multi-targeted inhibition of HSC activity in vivo and in vitro.
PMCID: PMC4232907  PMID: 24467283
2.  Regulation of Ethanol-Related Behavior and Ethanol Metabolism by the Corazonin Neurons and Corazonin Receptor in Drosophila melanogaster 
PLoS ONE  2014;9(1):e87062.
Impaired ethanol metabolism can lead to various alcohol-related health problems. Key enzymes in ethanol metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH); however, neuroendocrine pathways that regulate the activities of these enzymes are largely unexplored. Here we identified a neuroendocrine system involving Corazonin (Crz) neuropeptide and its receptor (CrzR) as important physiological regulators of ethanol metabolism in Drosophila. Crz-cell deficient (Crz-CD) flies displayed significantly delayed recovery from ethanol-induced sedation that we refer to as hangover-like phenotype. Newly generated mutant lacking Crz Receptor (CrzR01) and CrzR-knockdown flies showed even more severe hangover-like phenotype, which is causally associated with fast accumulation of acetaldehyde in the CrzR01 mutant following ethanol exposure. Higher levels of acetaldehyde are likely due to 30% reduced ALDH activity in the mutants. Moreover, increased ADH activity was found in the CrzR01 mutant, but not in the Crz-CD flies. Quantitative RT-PCR revealed transcriptional upregulation of Adh gene in the CrzR01. Transgenic inhibition of cyclic AMP-dependent protein kinase (PKA) also results in significantly increased ADH activity and Adh mRNA levels, indicating PKA-dependent transcriptional regulation of Adh by CrzR. Furthermore, inhibition of PKA or cAMP response element binding protein (CREB) in CrzR cells leads to comparable hangover-like phenotype to the CrzR01 mutant. These findings suggest that CrzR-associated signaling pathway is critical for ethanol detoxification via Crz-dependent regulation of ALDH activity and Crz-independent transcriptional regulation of ADH. Our study provides new insights into the neuroendocrine-associated ethanol-related behavior and metabolism.
PMCID: PMC3904974  PMID: 24489834
3.  Feasibility of a Laparoscopic Approach for Generalized Peritonitis from Perforated Appendicitis in Children 
Yonsei Medical Journal  2013;54(6):1478-1483.
This study evaluated the feasibility of a laparoscopic approach in children with generalized peritonitis secondary to perforated appendicitis.
Materials and Methods
We retrospectively analyzed the medical records of patients who underwent laparoscopic appendectomy with drainage for generalized peritonitis secondary to perforated appendicitis at our hospital between September 2001 and April 2012. Laparoscopic outcomes were compared with outcomes of an open method for perforated appendicitis.
Ninety-nine patients underwent laparoscopic appendectomy (LA) for generalized peritonitis from perforated appendicitis, and 87 patients underwent open appendectomy (OA) for perforated appendicitis. Wound infection was more common in the OA group (12.6%) than in the LA group (4.0%; p=0.032). The incidence of intestinal obstruction during long-term follow-up was significantly higher in the OA group (4.6% vs. 0.0% in the LA group; p=0.046). LA was possible in most patients for whom LA was attempted, with a conversion rate of 10.8%. Conversion to OA was affected by the preoperative duration of symptoms and the occurrence of intraoperative complications.
LA is feasible for use in children with generalized peritonitis from perforated appendicitis, with reasonable open conversion and perioperative complication rates comparable to those of the OA group.
PMCID: PMC3809857  PMID: 24142654
Appendicitis; peritonitis; laparoscopy; children
4.  Single Oral Dose Toxicity Study of Prebrewed Armeniacae Semen in Rats 
Toxicological Research  2013;29(2):91-98.
Armeniacae semen (AS) has been considered a toxic herb in the Korean medicine as it contains hydrogen cyanide and amygdalin, especially in its endocarp. Therefore, prebrewed AS that is devoid of endocarp has been traditionally used. In the present study, amygdalin content of the prebrewed AS was significantly lower (2.73 ± 0.32 μg/ml; p < 0.01) than the content in the extract that contained the endocarps (28.50 ± 6.71 μg/ml); amygdalin content corresponded to 10% of the extract in the present study. Because of single oral dose toxicity of prebrewed AS according to the recommendation of Korea Food and Drug Administration Guidelines (2009-116, 2009), which was based on single oral dose toxicity study of prebrewed AS, mortality due to toxic principles was significantly reduced. In this study, 2,000 mg/kg of prebrewed AS led to death of 1 female rat and 1 male rat at the end of 2 hr of administration. Based on these results, the 50% lethal dose in both male and female rats was determined to be 9279.5 mg/kg. Seizure, loss of locomotion, and increases in respiration and heart rate were observed as prebrewed AS treatment-related toxicological signs; these signs were restrictedly manifested in the prebrewed AS (2,000 mg/kg)-treated rats. In addition, no changes were observed in body weight, organ weight, gross features, and histopathological parameters with 2,000 mg/kg of AS in both male and female rats. These findings serve as direct evidence that amygdalin in AS is the toxic principle, which can be reduced by the traditional prebrewing method involving the exclusion of endocarp.
PMCID: PMC3834446  PMID: 24278634
Prebrewed Armeniacae Semen; Single oral dose toxicity; Rat; Amygdalin; Histopathology
5.  Porous Polyimide Membranes Prepared by Wet Phase Inversion for Use in Low Dielectric Applications 
A wet phase inversion process of polyamic acid (PAA) allowed fabrication of a porous membrane of polyimide (PI) with the combination of a low dielectric constant (1.7) and reasonable mechanical properties (Tensile strain: 8.04%, toughness: 3.4 MJ/m3, tensile stress: 39.17 MPa, and young modulus: 1.13 GPa), with further thermal imidization process of PAA. PAA was simply synthesized from purified pyromellitic dianhydride (PMDA) and 4,4-oxydianiline (ODA) in two different reaction solvents such as γ-butyrolactone (GBL) and N-methyl-2-pyrrolidinone (NMP), which produce Mw/PDI of 630,000/1.45 and 280,000/2.0, respectively. The porous PAA membrane was fabricated by the wet phase inversion process based on a solvent/non-solvent system via tailored composition between GBL and NMP. The porosity of PI, indicative of a low electric constant, decreased with increasing concentration of GBL, which was caused by sponge-like formation. However, due to interplay between the low electric constant (structural formation) and the mechanical properties, GBL was employed for further exploration, using toluene and acetone vs. DI-water as a coagulation media. Non-solvents influenced determination of the PAA membrane size and porosity. With this approach, insight into the interplay between dielectric properties and mechanical properties will inform a wide range of potential low-k material applications.
PMCID: PMC3676751  PMID: 23615465
low K material; porous polyimide; poly amic acid; wet phase inversion
6.  A Hexane Fraction of Guava Leaves (Psidium guajava L.) Induces Anticancer Activity by Suppressing AKT/Mammalian Target of Rapamycin/Ribosomal p70 S6 Kinase in Human Prostate Cancer Cells 
Journal of Medicinal Food  2012;15(3):231-241.
This study was carried out to evaluate the anticancer effects of guava leaf extracts and its fractions. The chemical compositions of the active extracts were also determined. In the present study, we set out to determine whether the anticancer effects of guava leaves are linked with their ability to suppress constitutive AKT/mammalian target of rapamycin (mTOR)/ribosomal p70 S6 kinase (S6K1) and mitogen-activated protein kinase (MAPK) activation pathways in human prostate cancer cells. We found that guava leaf hexane fraction (GHF) was the most potent inducer of cytotoxic and apoptotic effects in PC-3 cells. The molecular mechanism or mechanisms of GHF apoptotic potential were correlated with the suppression of AKT/mTOR/S6K1 and MAPK signaling pathways. This effect of GHF correlated with down-regulation of various proteins that mediate cell proliferation, cell survival, metastasis, and angiogenesis. Analysis of GHF by gas chromatography and gas chromatography–mass spectrometry tentatively identified 60 compounds, including β-eudesmol (11.98%), α-copaene (7.97%), phytol (7.95%), α-patchoulene (3.76%), β-caryophyllene oxide (CPO) (3.63%), caryophylla-3(15),7(14)-dien-6-ol (2.68%), (E)-methyl isoeugenol (1.90%), α-terpineol (1.76%), and octadecane (1.23%). Besides GHF, CPO, but not phytol, also inhibited the AKT/mTOR/S6K1 signaling pathway and induced apoptosis in prostate cancer cells. Overall, these findings suggest that guava leaves can interfere with multiple signaling cascades linked with tumorigenesis and provide a source of potential therapeutic compounds for both the prevention and treatment of cancer.
PMCID: PMC3282482  PMID: 22280146
AKT/mammalian target of rapamycin/ribosomal p70 S6 kinase; apoptosis; guava leaves; prostate cancer
7.  Draft Genome Sequence of Commensalibacter intestini A911T, a Symbiotic Bacterium Isolated from Drosophila melanogaster Intestine 
Journal of Bacteriology  2012;194(5):1246.
Commensalibacter intestini A911T, a predominant symbiotic bacterium capable of stably colonizing gut epithelia, was isolated from the fruit fly, Drosophila melanogaster. Here we report the draft genome sequence of Commensalibacter intestini A911T.
PMCID: PMC3294769  PMID: 22328749
8.  Draft Genome Sequence of Gluconobacter morbifer G707T, a Pathogenic Gut Bacterium Isolated from Drosophila melanogaster Intestine 
Journal of Bacteriology  2012;194(5):1245.
Gluconobacter morbifer G707T, a minor member of gut microbiota, was isolated from fruit fly (Drosophila melanogaster). Here, the draft genome sequence of Gluconobacter morbifer G707T is reported.
PMCID: PMC3294801  PMID: 22328748
9.  Clinical characteristics and treatment of esophageal atresia: a single institutional experience 
Treatment for esophageal atresia has advanced over several decades due to improvements in surgical techniques and neonatal intensive care. Subsequent to increased survival, postoperative morbidity has become an important issue in this disease. The aim of our study was to analyze our experience regarding the treatment of esophageal atresia.
We reviewed and analyzed the clinical data of patients who underwent surgery for esophageal atresia at Severance Children's Hospital from 1995 to 2010 regarding demographics, surgical procedures, and postoperative outcomes.
Seventy-two patients had surgery for esophageal atresia. The most common gross type was C (81.9%), followed by type A (15.3%). Primary repair was performed in 52 patients. Staged operation was performed in 17 patients. Postoperative esophageal strictures developed in 43.1% of patients. Anastomotic leakages occurred in 23.6% of patients, and recurrence of tracheoesophageal fistula was reported in 8.3% of patients. Esophageal stricture was significantly associated with long-gap (≥3 cm or three vertebral bodies) atresia (P = 0.042). The overall mortality rate was 15.3%. The mortality in patients weighing less than 2.5 kg was higher than in patients weighing at least 2.5 kg (P = 0.001). During the later period of this study, anastomotic leakage and mortality both significantly decreased compared to the earlier study period (P = 0.009 and 0.023, respectively).
The survival of patients with esophageal atresia has improved over the years and the rate of anastomotic leakage has been significantly reduced. However, overall morbidities related to surgical treatment of esophageal atresia still exists with high incidence.
PMCID: PMC3392315  PMID: 22792533
Esophageal atresia; Tracheoesophageal fistula; Prognosis; Survival
10.  Suppression of STAT3 and HIF-1 Alpha Mediates Anti-Angiogenic Activity of Betulinic Acid in Hypoxic PC-3 Prostate Cancer Cells 
PLoS ONE  2011;6(6):e21492.
Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that betulinic acid (BA), a triterpene from the bark of white birch, had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells.
Methodology/Principal Findings
BA inhibited the protein expression and the transcriptional activities of hypoxia-inducible factor-1α (HIF-1α) under hypoxic condition. Consistently, BA blocked hypoxia-induced phosphorylation, DNA binding activity and nuclear accumulation of STAT3. In addition, BA significantly reduced cellular and secreted levels of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Furthermore, BA prevented in vitro capillary tube formation in human umbilical vein endothelial cells (HUVECs) maintained in conditioned medium of hypoxic PC-3 cells, implying anti-angiogenic activity of BA under hypoxic condition. Of note, chromatin immunoprecipitation (ChiP) assay revealed that BA inhibited binding of HIF-1α and STAT3 to VEGF promoter. Furthermore, silencing STAT3 using siRNA transfection effectively enhanced the reduced VEGF production induced by BA treatment under hypoxia.
Taken together, our results suggest that BA has anti-angiogenic activity by disturbing the binding of HIF-1α and STAT3 to the VEGF promoter in hypoxic PC-3 cells.
PMCID: PMC3123343  PMID: 21731766
11.  A Milestone in Codifying the Wisdom of Traditional Oriental Medicine: TCM, Kampo, TKM, TVM—WHO International Standard Terminologies on Traditional Medicine in the Western Pacific Region 
The WHO published a dictionary-type book entitled ‘WHO International Standard Terminologies on Traditional Medicine in the Western Pacific Region’ which has a total of 3259 technical terms which have been commonly used in traditional Chinese (TCM), Japanese (Kampo), Korean (TKM) and Vietnamese (TVM) medicines. In this comprehensive guide, each term has the English expression, the original Chinese character and a concise English definition. The book covers 3106 terms from basic theories, diagnostics, diseases, various therapeutics including acupuncture and moxibustion and even the English wording of 153 titles which are considered the most important traditional medical classics published in these four countries. A prominent feature of the compilation is the codification format that assigns numbers in hundred decimal units for each category of the section. This type of coding system provides the flexibility for adding more terminologies in the future and is useful for constructing a database for the retrieval of various published scientific articles. Overall, the usage of these standard terminologies is highly desirable to deliver accurate meanings, and ultimately to avoid a variety of expressions for a single term in different scientific manuscripts on Oriental medicine.
PMCID: PMC2887335  PMID: 19124553
Oriental medicine; standard terminology; traditional medicine; WHO
12.  Artificial neural network models for prediction of intestinal permeability of oligopeptides 
BMC Bioinformatics  2007;8:245.
Oral delivery is a highly desirable property for candidate drugs under development. Computational modeling could provide a quick and inexpensive way to assess the intestinal permeability of a molecule. Although there have been several studies aimed at predicting the intestinal absorption of chemical compounds, there have been no attempts to predict intestinal permeability on the basis of peptide sequence information. To develop models for predicting the intestinal permeability of peptides, we adopted an artificial neural network as a machine-learning algorithm. The positive control data consisted of intestinal barrier-permeable peptides obtained by the peroral phage display technique, and the negative control data were prepared from random sequences.
The capacity of our models to make appropriate predictions was validated by statistical indicators including sensitivity, specificity, enrichment curve, and the area under the receiver operating characteristic (ROC) curve (the ROC score). The training and test set statistics indicated that our models were of strikingly good quality and could discriminate between permeable and random sequences with a high level of confidence.
We developed artificial neural network models to predict the intestinal permeabilities of oligopeptides on the basis of peptide sequence information. Both binary and VHSE (principal components score Vectors of Hydrophobic, Steric and Electronic properties) descriptors produced statistically significant training models; the models with simple neural network architectures showed slightly greater predictive power than those with complex ones. We anticipate that our models will be applicable to the selection of intestinal barrier-permeable peptides for generating peptide drugs or peptidomimetics.
PMCID: PMC1955455  PMID: 17623108
13.  Codon 201Gly Polymorphic Type of the DCC Gene is Related to Disseminated Neuroblastoma1 
Neoplasia (New York, N.Y.)  2001;3(4):267-272.
The deleted in colorectal carcinoma (DCC) gene is a potential tumor-suppressor gene on chromosome 18q21.3. The relatively high frequency of loss of heterozygosity (LOH) and loss of expression of this gene in neuroblastoma, especially in the advanced stages, imply the possibility of involvement of the DCC gene in progression of neuroblastoma. However, only few typical mutations have been identified in this gene, indicating that other possible mechanisms for the inactivation of this gene may exist. A polymorphic change (Arg to Gly) at DCC codon 201 is related to advanced colorectal carcinoma and increases in the tumors with absent DCC protein expression. In order to understand whether this change is associated with the development or progression of neuroblastoma, we investigated codon 201 polymorphism of the DCC gene in 102 primary neuroblastomas by polymerase chain reaction single-strand conformation polymorphism. We found no missense or nonsense mutations, but a polymorphic change from CGA (Arg) to GGA (Gly) at codon 201 resulting in three types of polymorphism: codon 201Gly type, codon 201Arg/Gly type, and codon 201Arg type. The codon 201Gly type occurred more frequently in disseminated (stages IV and IVs) neuroblastomas (72%) than in localized (stages I, II, and III) tumors (48%) (P=.035), and normal controls (38%) (P=.024). In addition, the codon 201Gly type was significantly more common in tumors found clinically (65%) than in those found by mass screening (35%) (P=.002). The results suggested that the codon 201Gly type of the DCC gene might be associated with a higher risk of disseminating neuroblastoma.
PMCID: PMC1505858  PMID: 11571626
tumor-suppressor gene; the DCC gene; PCR-SSCP; codon 201 polymorphism; neuroblastoma

Results 1-13 (13)