Publications by authors named "Hyojeong Lee"

15 Publications

  • Page 1 of 1

Transcriptomic alterations induced by aflatoxin B1 and ochratoxin A in LMH cell line.

Poult Sci 2020 Nov 7;99(11):5265-5274. Epub 2020 Aug 7.

Department of Animal Life Science, Kangwon National University, Chuncheon-si, Gangwon-do 24341, Korea. Electronic address:

Aflatoxin B1 (AFB1) and ochratoxin A (OTA), which are toxic metabolites of ubiquitously occurring molds, show diverse toxicological effects such as hepatotoxicity, genotoxicity, and immunotoxicity in human and animals. Despite poultry show sensitivity to AFB1 and OTA, the mechanism of these mycotoxins in chickens has not been fully investigated. Here, we aimed to elucidate the molecular mechanism induced by AFB1 and/or OTA in chicken hepatic cells using transcriptomic analysis. Aflatoxin B1 and OTA induced cytotoxic effects in a dose-dependent manner at 48 h after exposure. Furthermore, correlation effect indicated an antagonism between the 2 toxins. The mRNA sequencing of AFB1-treated or OTA-treated chicken hepatocarcinoma and functional analysis revealed the pathways that were commonly regulated by both mycotoxins, especially PPAR signaling, focal adhesion, and MAPK signaling. Based on these findings, a possible hypothesis is that AFB1 and OTA have similar toxic mechanisms and compete for some steps in the chicken liver, and it is expected that the mycotoxins would have antagonistic effects. In addition, genes identified through transcriptome analysis provide candidates for further study of AFB1 and OTA toxicity and targets for efforts to improve the health of chickens exposed to mycotoxins.
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http://dx.doi.org/10.1016/j.psj.2020.05.058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7647754PMC
November 2020

Immunopathogenesis of ANCA-Associated Vasculitis.

Int J Mol Sci 2020 Oct 3;21(19). Epub 2020 Oct 3.

Department of Pediatrics, Yonsei University College of Medicine, Seoul 03722, Korea.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is an autoimmune disorder which affects small- and, to a lesser degree, medium-sized vessels. ANCA-associated vasculitis encompasses three disease phenotypes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). This classification is largely based on clinical presentations and has several limitations. Recent research provided evidence that genetic background, risk of relapse, prognosis, and co-morbidities are more closely related to the ANCA serotype, proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, compared to the disease phenotypes GPA or MPA. This finding has been extended to the investigation of biomarkers predicting disease activity, which again more closely relate to the ANCA serotype. Discoveries related to the immunopathogenesis translated into clinical practice as targeted therapies are on the rise. This review will summarize the current understanding of the immunopathogenesis of ANCA-associated vasculitis and the interplay between ANCA serotype and proposed disease biomarkers and illustrate how the extending knowledge of the immunopathogenesis will likely translate into development of a personalized medicine approach in the management of ANCA-associated vasculitis.
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http://dx.doi.org/10.3390/ijms21197319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7584042PMC
October 2020

Structural Characterization of Glycerophosphorylated and Succinylated Cyclic β-(1→2)-d-Glucan Produced by 1021.

Polymers (Basel) 2020 Sep 12;12(9). Epub 2020 Sep 12.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.

produces different types of surface polysaccharides. Among them, cyclic β-(1→2)-d-glucan is located in the periplasmic space of rhizobia and plays an important role in the adaptation of bacteria to osmotic adaptation. Cyclic β-(1→2)-d-glucan (CG), synthesized from 1021, has a neutral and anionic form. In the present study, we characterized the exact chemical structures of anionic CG after purification using size exclusion s (Bio-Gel P-6 and P-2) chromatography, and DEAE-Sephadex anion exchange chromatography. The exact structure of each isolated anionic CG was characterized using various analytical methods such as nuclear magnetic resonance (NMR), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and matrix associated laser desorption ionization-time of Flight (MALDI-TOF) mass spectrometry. The precise chemical structures of novel anionic CG molecules were elucidated by various NMR spectroscopic analyses, including H, C, P, and 2D HSQC NMR spectroscopy. As a result, we discovered that anionic CG molecules have either glycerophosphoryl or succinyl residues at C6 positions of a neutral CG. In addition, the results of MALDI-TOF mass spectrometric analysis confirmed that there are two types of patterns for anionic CG peaks, where one type of peak was the succinylated CG (SCG) and the other was glycerophospholated CG (GCG). In addition, it was revealed that each anionic CG has one to four substituents of the succinyl group of SCG and glycerophosphoryl group of GCG, respectively. Anionic CG could have potential as a cyclic polysaccharide for drug delivery systems and a chiral separator based on the complexation with basic target molecules.
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http://dx.doi.org/10.3390/polym12092073DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7569799PMC
September 2020

Succinoglycan dialdehyde-reinforced gelatin hydrogels with toughness and thermal stability.

Int J Biol Macromol 2020 Apr 23;149:281-289. Epub 2020 Jan 23.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea; Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, South Korea. Electronic address:

Pure gelatin hydrogel (PG) has limited practical applications due to their thermal instability and unfavorable mechanical properties. To overcome these limitations, dually crosslinked hydrogels were developed by imparting chemical crosslinking to existing physically crosslinked gelatin hydrogel networks using succinoglycan dialdehyde (SGDA) as a macromolecular crosslinker. SGDA-reinforced gelatin hydrogels (SGDA/Gels) displayed an 11 times higher compressive stress under identical deformation strain and a 1040% improvement in storage modulus (G') than PG. In addition, chemical crosslinking induced by SGDA increased the thermal stability of SGDA/Gels, such that they did not decompose at 60 °C, as confirmed by oscillatory temperature ramp experiments. The newly synthesized SGDA/Gels with reinforced networks and thermal stability exhibit potential for long-term use as controlled drug delivery carriers and 3D cell culture scaffolds for tissue engineering.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.01.228DOI Listing
April 2020

Evaluation of Thermal Properties of 3D Spacer Technical Materials in Cold Environments using 3D Printing Technology.

Polymers (Basel) 2019 Sep 2;11(9). Epub 2019 Sep 2.

Dept. of Clothing & Textiles, Chungnam National University, Yuseong, Daejeon 34134, Korea.

Novel materials have been recently developed for coping with various environmental factors. Generally, to improve the thermal comfort to humans in cold environments, securing an air layer is important. Therefore, this study analyzed the thermal properties of 3D spacer technical materials, 3D printed using thermoplastic polyurethane, according to the structural changes. Four 3D spacer technical material structures were designed with varying pore size and thickness. These samples were moved into a cold climate chamber (temperature 5 ± 1 °C, relative humidity (60 ± 5)%, wind velocity 0.2 m/s) and placed on a heating plate set to 30 °C. The surface and internal temperatures were measured after 0, 10, 20, and 30 min and then 10 min after turning off the heating plate. When heat was continuously supplied, the 3D spacer technical material with large pores and a thick air layer showed superior insulation among the materials. However, when no heat was supplied, the air gap thickness dominantly affected thermal insulation, regardless of the pore size. Hence, increasing the air gap is more beneficial than increasing the pore size. Notably, we found that the air gap can increase insulation efficiency, which is of importance to the new concept of 3D printing an interlining.
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http://dx.doi.org/10.3390/polym11091438DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6780595PMC
September 2019

Anticancer activity of gomisin J from Schisandra chinensis fruit.

Oncol Rep 2019 Jan 2;41(1):711-717. Epub 2018 Nov 2.

Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Republic of Korea.

In attempting to identify effective anticancer drugs from natural products that are harmless to humans, we found that the gomisin J from Schisandra chinensis fruit has anticancer activity. Schisandra chinensis fruits are used in traditional herbal medicine and gomisin J is one of their chemical constituents. In the present study, we examined the anticancer activity of gomisin J in MCF7 and MDA-MB-231 breast cancer cell lines and in MCF10A normal cell line, in a time- and concentration-dependent manner. Our data revealed that gomisin J exerted a much stronger cytotoxic effect on MCF7 and MDA-MB-231 cancer cells than on MCF10A normal cells. Gomisin J suppressed the proliferation and decreased the viability of MCF7 and MDA-MB-231 cells at relatively low (<10 µg/ml) and high (>30 µg/ml) concentrations, respectively. Our data also revealed that gomisin J induced necroptosis, a programmed form of necrosis, as well as apoptosis. Notably, gomisin J predominantly induced necroptosis in MCF7 cells that are known to have high resistance to many pro-apoptotic anticancer drugs, while MDA-MB-231 exhibited a much lower level of necroptosis but instead a higher level of apoptosis. This data indicated the possibility that it may be used as a more effective anticancer drug, especially in apoptosis-resistant malignant cancer cells. In an extended study, gomisin J exhibited a strong cytotoxic effect on all tested various types of 13 cancer cell lines, indicating its potential to be used against a wide range of different types of cancer cells.
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http://dx.doi.org/10.3892/or.2018.6850DOI Listing
January 2019

Inhibitory role of AMP‑activated protein kinase in necroptosis of HCT116 colon cancer cells with p53 null mutation under nutrient starvation.

Int J Oncol 2019 Feb 14;54(2):702-712. Epub 2018 Nov 14.

Department of Biological Science, Sookmyung Women's University, Seoul 04310, Republic of Korea.

Simultaneous induction of other types of programmed cell death, alongside apoptosis, in cancer cells may be considered an attractive strategy for the development of more effective anticancer therapies. The present study aimed to investigate the role of AMP‑activated protein kinase (AMPK) in nutrient/serum starvation‑induced necroptosis, which is a programmed form of necrosis, in the presence or absence of p53. The present study detected higher cell proliferation and lower cell death rates in the HCT116 human colon cancer cell line containing a p53 null mutation (HCT116 p53‑/‑) compared with in HCT116 cells harboring wild‑type p53 (HCT116 p53+/+), as determined using a cell viability assay. Notably, western blot analysis revealed a relatively lower level of necroptosis in HCT116 p53‑/‑ cells compared with in HCT116 p53+/+ cells. Investigating the mechanism, it was revealed that necroptosis may be induced in HCT116 p53+/+ cells by significantly increasing reactive oxygen species (ROS) and decreasing mitochondrial membrane potential (MMP), whereas little alterations were detected in HCT116 p53‑/‑ cells. Unexpectedly, a much lower level of ATP was detected in HCT116 p53‑/‑ cells compared with in HCT116 p53+/+ cells. Accordingly, AMPK phosphorylation on the Thr172 residue was markedly increased in HCT116 p53‑/‑ cells. Furthermore, western blot analysis and ROS measurements indicated that AMPK inhibition, using dorsomorphin dihydrochloride, accelerated necroptosis by increasing ROS generation in HCT116 p53‑/‑ cells. However, AMPK activation by AICAR did not suppress necroptosis in HCT116 p53+/+ cells. In conclusion, these data strongly suggested that AMPK activation may be enhanced in HCT116 p53‑/‑ cells under serum‑depleted conditions via a drop in cellular ATP levels. In addition, activated AMPK may be at least partially responsible for the inhibition of necroptosis in HCT116 p53‑/‑ cells, but not in HCT116 p53+/+cells.
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http://dx.doi.org/10.3892/ijo.2018.4634DOI Listing
February 2019

Anti-cancerous effect of cis-khellactone from through the induction of three programmed cell deaths.

Oncotarget 2018 Mar 30;9(24):16744-16757. Epub 2018 Mar 30.

Department of Biological Science, Sookmyung Women's University, Seoul, 14310, South Korea.

has traditionally been used to treat various medical problems. In this report, we introduce cis-khellactone as a new anti-cancer agent, which was isolated from the chloroform soluble fraction of the rhizomes of . Its anti-cancerous effect was at first tested in MCF7 and MDA-MB-231 breast cell lines, in which MCF7 is well known to be resistant to many anti-cancer drugs; MCF10A normal breast cell line was used as a control. experiments showed that cis-khellactone suppressed cell growth and proliferation at a relatively low concentrations (<5 μg/ml) and decreased cell viability at high concentrations (>10 μg/ml) in both cancer cell lines in a time- and concentration-dependent manner. This anti-cancerous effect was also checked in additional 16 different types of normal and cancer cell lines. Cis-khellactone treatment significantly suppressed cell proliferation and enhanced cell death in all tested cancer cell lines. Furthermore, Western blot analysis showed that cis-khellactone induced three types of programmed cell death (PCD): apoptosis, autophagy-mediated cell death, and necrosis/necroptosis. Cis-khellactone concentration-dependently decreased cell viability by increasing the level of reactive oxygen species (ROS) and decreasing mitochondrial membrane potential (MMP), which are related to all three types of PCD. Mitochondrial fractionation data revealed that cis-khellactone induced the translocation of BAX and BAK into mitochondria as well as the overexpression of VDAC1, which probably accelerates MMP disruption and finally cell death. Importantly, our extended studies with xenograft model further confirmed these findings of anti-cancerous effects and showed no harmful effects in normal tissues, suggesting that there would be no side effects in humans.
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http://dx.doi.org/10.18632/oncotarget.24686DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5908283PMC
March 2018

The impact of intensive grandchild care on depressive symptoms among older Koreans.

Int J Geriatr Psychiatry 2017 12 1;32(12):1381-1391. Epub 2016 Dec 1.

Institute of Health Services Research, Yonsei University, Seoul, Korea.

Objective: The aim of this study was to investigate the impact of intensive grandchild care on depressive symptoms among grandparents.

Methods: We used data from 2008 to 2012 of the Korea Longitudinal Study of Aging. Using the data from 2008 at baseline, data included 5129 individuals aged 50 years and more without depression with at least one grandchild. A generalized estimating equation was used to investigate the impact of intensive grandchild care on depressive symptoms. Investigated factors included the intensity of grandchild care, measured by hours spent caring for a grandchild per week: (i) none (0 h); (ii) non-intensive grandchild care (1-39 h); and intensive grandchild care (≥40 h). Depressive symptoms were measured using the 10-item Center for Epidemiological Studies Depression scale.

Results: Among 5128 participants from 2008 to 2012, 3.0% were providing non-intensive grandchildren care, and 1.9% were providing intensive grandchild care. Compared with grandparents providing no grandchild care, those who provided intensive grandchild care experienced reduced depressive symptoms (β = -0.51 [p = 0.007] vs. no childcare). Men (β = -1.22 [p = 0.012] vs. no childcare) providing intensive grandchild care experienced a greater reduction in depressive symptoms compared with women (β = -0.44 [p = 0.029] vs. no childcare) providing grandchild care. Grandparents who were receiving financial support from adult children were more likely to experience reduced depressive symptoms than those not receiving such support.

Conclusion: The results of this study reveal that intensive grandchild care is associated with lower depressive symptoms among older adults, particularly men. The findings emphasize the importance of encouraging older adults to participate in grandchild care, regardless of gender. Copyright © 2016 John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/gps.4625DOI Listing
December 2017

Prediction of Ventricular Tachycardia One Hour before Occurrence Using Artificial Neural Networks.

Sci Rep 2016 08 26;6:32390. Epub 2016 Aug 26.

Department of Biomedical Engineering, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Ventricular tachycardia (VT) is a potentially fatal tachyarrhythmia, which causes a rapid heartbeat as a result of improper electrical activity of the heart. This is a potentially life-threatening arrhythmia because it can cause low blood pressure and may lead to ventricular fibrillation, asystole, and sudden cardiac death. To prevent VT, we developed an early prediction model that can predict this event one hour before its onset using an artificial neural network (ANN) generated using 14 parameters obtained from heart rate variability (HRV) and respiratory rate variability (RRV) analysis. De-identified raw data from the monitors of patients admitted to the cardiovascular intensive care unit at Asan Medical Center between September 2013 and April 2015 were collected. The dataset consisted of 52 recordings obtained one hour prior to VT events and 52 control recordings. Two-thirds of the extracted parameters were used to train the ANN, and the remaining third was used to evaluate performance of the learned ANN. The developed VT prediction model proved its performance by achieving a sensitivity of 0.88, specificity of 0.82, and AUC of 0.93.
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http://dx.doi.org/10.1038/srep32390DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4999952PMC
August 2016

Natural course of an untreated metastatic perirectal lymph node after the endoscopic resection of a rectal neuroendocrine tumor.

Intest Res 2015 Apr 27;13(2):175-9. Epub 2015 Apr 27.

Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Lymph node metastasis is rare in small (i.e., <10 mm) rectal neuroendocrine tumors (NETs). In addition to tumor size, pathological features such as the mitotic or Ki-67 proliferation index are associated with lymph node metastasis in rectal NETs. We recently treated a patient who underwent endoscopic treatment of a small, grade 1 rectal NET that recurred in the form of perirectal lymph node metastasis 7 years later. A 7-mm-sized perirectal lymph node was noted at the time of the initial endoscopic treatment. The same lymph node was found to be slightly enlarged on follow-up and finally confirmed as a metastatic NET. Therefore, the perirectal lymph node metastasis might have been present at the time of the initial diagnosis. However, the growth rate of the lymph node was extremely low, and it took 7 years to increase in size from 7 to 10 mm. NETs with low Ki-67 proliferation index and without mitotic activity may grow extremely slowly even if they are metastatic.
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http://dx.doi.org/10.5217/ir.2015.13.2.175DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4414761PMC
April 2015

Patient descriptions of rectal effluents may help to predict the quality of bowel preparation with photographic examples.

Intest Res 2015 Apr 27;13(2):153-9. Epub 2015 Apr 27.

Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background/aims: Previous studies have suggested a weak correlation between self-reported rectal effluent status and bowel preparation quality. We aim to evaluate whether photographic examples of rectal effluents could improve the correlation between patient descriptions of rectal effluents and bowel preparation quality.

Methods: Before colonoscopy, patients were asked to describe the nature of their last three rectal effluents. Photographic examples of rectal effluents were provided as a reference for scoring. Bowel preparation was subsequently assessed by a single endoscopist using a global preparation assessment scale. Preparation outcomes were grouped into two levels (excellent to good vs. fair to inadequate). Both univariate and multivariate logistic regression models were used to find any association between bowel preparation quality and patient characteristics.

Results: A total of 138 patients completed the questionnaires. The mean age was 56.5±10.4 years. The mean sum of the last three rectal effluent scores was 5.9±2.0. Higher rectal effluent scores (odds ratio [OR], 0.82; P=0.043) and the presence of diverticula (OR, 0.16; P<0.001) were risk factors for suboptimal preparation.

Conclusions: Photographic example-guided patient descriptions of rectal effluents showed a statistically significant association with bowel preparation quality. However, clinical significance seemed to be low. The presence of diverticula was an independent predictive factor for suboptimal bowel preparation quality.
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http://dx.doi.org/10.5217/ir.2015.13.2.153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4414757PMC
April 2015

Drug rash with eosinophilia and systemic symptoms syndrome following cholestatic hepatitis A: a case report.

Korean J Hepatol 2012 Mar 22;18(1):84-8. Epub 2012 Mar 22.

Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Hepatitis A virus (HAV) infections occur predominantly in children, and are usually self-limiting. However, 75-95% of the infections in adults are symptomatic (mostly with jaundice), with the illness symptoms usually persisting for a few weeks. Atypical manifestations include relapsing hepatitis, prolonged cholestasis, and complications involving renal injury. Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is a severe, drug-induced hypersensitivity reaction characterized by skin rash, fever, lymph-node enlargement, and internal organ involvement. We describe a 22-year-old male who presented with acute kidney injury and was diagnosed with prolonged cholestatic hepatitis A. The patient also developed DRESS syndrome due to antibiotic and/or antiviral treatment. To our knowledge, this is the first report of histopathologically confirmed DRESS syndrome due to antibiotic and/or antiviral treatment following HAV infection with cholestatic features and renal injury.
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http://dx.doi.org/10.3350/kjhep.2012.18.1.84DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3326989PMC
March 2012

Oriental herbs as a source of novel anti-androgen and prostate cancer chemopreventive agents.

Acta Pharmacol Sin 2007 Sep;28(9):1365-72

Hormel Institute, University of Minnesota, Austin, MN 55912, USA.

Androgen and androgen receptor (AR) signaling are crucial for the genesis of prostate cancer (PCa), which can often develop into androgen-ligand-independent diseases that are lethal to the patients. Recent studies show that even these hormone-refractory PCa require ligand-independent AR signaling for survival. As current chemotherapy is largely ineffective for PCa and has serious toxic sideeffects, we have initiated a collaborative effort to identify and develop novel, safe and naturally occurring agents that target AR signaling from Oriental medicinal herbs for the chemoprevention and treatment of PCa. We highlight our discovery of decursin from an Oriental formula containing Korean Angelica gigas Nakai (Dang Gui) root as a novel anti-androgen/AR agent. We have identified the following mechanisms to account for the specific anti-AR actions: rapid block of AR nuclear translocation, inhibition of binding of 5alpha-dihydrotestesterone to AR and increased proteasomal degradation of AR protein. Furthermore, decursin lacks the agonist activity of the "pure" anti-androgen bicalutamide and is more potent than bicalutamide in inducing PCa apoptosis. Structure-activity analyses reveal a critical requirement of the side-chain on decursin or its structural isomer decursinol angelate for anti-AR, cell cycle arrest and proapoptotic activities. This work demonstrates the feasibility of using activity-guided fractionation in cell culture assays combined with mechanistic studies to identify novel anti-androgen/ AR agents from complex herbal mixtures.
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http://dx.doi.org/10.1111/j.1745-7254.2007.00683.xDOI Listing
September 2007