Chang Lim Hyun

Jeju National University, Tse-tsiu, Jeju, South Korea

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Publications (16)18.82 Total impact

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    ABSTRACT: Abstract Purpose: Previously we demonstrated that phloroglucinol (1,3,5-trihydroxybenzene) protected human HaCaT keratinocytes against ultraviolet B (UVB, 280-315 nm)-induced oxidative stress in vitro by scavenging intracellular reactive oxygen species (ROS). The current study investigated whether phloroglucinol could similarly protect the mouse skin against UVB-induced oxidative tissue damage in vivo. Materials and methods: Male 7-week-old Balb/c mice were divided into the following untreated normal control, phloroglucinol only-treated, vehicle plus UVB (30 or 60 mJ/cm(2))-treated, and phloroglucinol (10 or 50 mg/ml) plus UVB (30 or 60 mJ/cm(2))-treated groups. Following UVB treatment, phloroglucinol or phosphate buffered saline vehicle was applied to the dorsal skin of each mouse daily for 3 days. Studies were conducted at 24 h after the last of the UVB exposures. Histopathological analyses of dorsal skin lesions were performed on all mice. In addition, the levels of UVB-provoked injury to cellular components, including DNA, proteins, and lipids were detected by levels of 8-hydroxyguanine (8-oxoG), protein carbonyls, and 8-isoprostane. Apoptosis were assessed by using western blot for B-cell lymphoma-2-associated X protein (Bax) and activated caspase-3 expression, by using immunohistochemistry. Results: UVB radiation increased the thickness of the epidermis and the dermis, and also stimulated the accumulation of mast cells in the irradiated skin. However, treatment with phloroglucinol significantly decreased all of these parameters. Furthermore, phloroglucinol decreased UVB-provoked injury to cellular components, including DNA, proteins, and lipids; down-regulated the expression of phospho-histone H2A.X in the injured skin; and reduced the UVB-generated levels of 8-oxoG, protein carbonyls, and 8-isoprostane, which are all markers of oxidative stress. In addition, phloroglucinol attenuated the UVB-induced expression of the pro-apoptotic proteins, Bax protein, and activated caspase-3. Conclusion: These results suggest that phloroglucinol safeguards the mouse skin against UVB-induced oxidative stress and apoptosis.
    International Journal of Radiation Biology 04/2014; · 1.90 Impact Factor
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    ABSTRACT: The cytoprotective effects of 6'-O-galloylpaeoniflorin against injury and death of human HaCaT keratinocytes resulting from ultraviolet B radiation were investigated. 6'-O-galloylpaeoniflorin exhibited the capacity to scavenge intracellular reactive oxygen species (ROS) generated by ultraviolet B radiation. 6'-O-galloylpaeoniflorin also attenuated ultraviolet B-induced oxidative macromolecular damage to DNA, lipids, and proteins, decreasing the number of DNA strand breaks, the level of 8-isoprostane (a biomarker of lipid peroxidation), and the level of protein carbonylation. Moreover, 6'-O-galloylpaeoniflorin rescued HaCaT cells from ultraviolet induced cell death, by downregulating the mitochondrial apoptotic pathway. Taken together, these results indicate that 6'-O-galloylpaeoniflorin has the potential to be developed as a medical agent against ROS-mediated skin diseases.
    In Vitro Cellular & Developmental Biology - Animal 04/2014; · 1.29 Impact Factor
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    ABSTRACT: The cytoprotective mechanism of 7, 8-dihydroxyflavone (DHF) against oxidative stress-induced cell damage with respect to its stimulatory effect on the expression of heme oxygenase-1 (HO-1), a potent antioxidant enzyme, was investigated in the present study. Up-regulation of HO-1 expression by DHF was both dose and time dependent in lung fibroblast V79-4 cells. DHF also increased the protein expression level of the transcription factor nuclear factor erythroid-2-related factor 2 (Nrf2), and induced the translocation of Nrf2 from the cytosol into the nucleus, leading to elevated HO-1 expression. The siNrf2 RNA-transfection attenuated HO-1 expression induced by DHF treatment. In addition, DHF induced the activation of extracellular signal-regulated kinase (ERK), while U0126 (a specific pharmacological inhibitor of ERK kinase) abrogated DHF-activated Nrf2 and HO-1 expression. This suggests that DHF increased the levels of Nrf2 and HO-1 via ERK-dependent pathways. Furthermore, DHF significantly prevented the reduction of cell viability in response to oxidative stress; however, U0126 attenuated the protective effect of DHF. Taken together, these results demonstrate that DHF protected cells from oxidative stress via the activation of an ERK/Nrf2/HO-1 signaling pathway.
    In Vitro Cellular & Developmental Biology - Animal 03/2014; · 1.29 Impact Factor
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    ABSTRACT: To evaluate the clinical and CT findings in patients with small-bowel Anisakiasis. Nineteen patients with small-bowel Anisakiasis and who underwent abdominal CT between 2005 and 2012 were enrolled in our study. All of these patients were diagnosed using either a serologic test for Anisakiasis (n = 18) or by pathology (n = 1). Their medical records were reviewed in order to determine the clinical findings. CT images were retrospectively reviewed by two radiologists to evaluate the characteristics of the involved bowel wall and the ancillary findings. All patients had presented with the acute onset of severe abdominal pain as well as a history of having recently eaten raw fish. The mean time interval from eating the fish to the onset of abdominal pain was 1.7 days. Eighteen patients were treated conservatively and experienced resolution of their symptoms within seven days of hospitalization. One patient underwent surgical exploration for presumed small-bowel ischemia. The sites of involvement included the ileum (16/19, 84%) and jejunum (3/19, 16%). All patients had circumferential bowel-wall thickening (mean, 0.8 cm) with an intermediate length of involved bowel (mean, 7.9 cm). Small-bowel obstruction occurred in 16 patients (84%). The target sign was present in 17 patients (89%), ascites, particularly in the perilesional area, in 16 patients (84%), and mesenteric edema in 15 patients (79%). Small-bowel Anisakiasis should be considered in the differential diagnosis of acute abdomen in order to avoid unnecessary surgery when patients present with abdominal pain after having recently eaten raw fish, concentric bowel-wall thickening with the target sign in the ileum, perilesional ascites, as well as bowel obstruction seen on CT.
    Abdominal Imaging 02/2014; · 1.91 Impact Factor
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    ABSTRACT: This study investigated the cytoprotective effect of Ecklonia cava-derived eckol against H2 O2 -induced mitochondrial dysfunction in Chang liver cells. While H2 O2 augmented levels of mitochondrial reactive oxygen species (ROS), eckol decreased it. Eckol also attenuated high intracellular Ca(2+) levels stimulated by H2 O2 and recovered H2 O2 -diminished ATP levels and succinate dehydrogenase activity. Eckol time-dependently increased the expression of manganese superoxide dismutase (Mn SOD), a mitochondrial antioxidant enzyme with cytoprotective effect against oxidative stress. Eckol recovered Mn SOD expression and activity that were decreased by H2 O2 . Finally, eckol induced Mn SOD through phosphorylated AMP-activated protein kinase (AMPK) and forkhead box O3a (FoxO3a). Specific silencing RNAs (siRNAs) against FoxO3a and AMPK reduced eckol-stimulated Mn SOD expression, and diethyldithiocarbamate (Mn SOD inhibitor) and siRNA against Mn SOD reduced the cytoprotective effect of eckol against H2 O2 -provoked cell death. These results demonstrate that eckol protects cells from mitochondrial oxidative stress by activating AMPK/FoxO3a-mediated induction of Mn SOD. J. Cell. Biochem. 9999: XX-XX, 2014. © 2013 Wiley Periodicals, Inc.
    Journal of Cellular Biochemistry 02/2014; · 3.06 Impact Factor
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    ABSTRACT: The aim of the present study was to elucidate the protective properties of 3,4-dihydroxybenzoic acid (DBA) isolated from Cladophora wrightiana Harvey (a green alga) against ultraviolet B (UVB)-induced damage to human HaCaT keratinocytes. DBA exhibited scavenging actions against the 1,1-diphenyl-2-picrylhydrazyl radical, the superoxide anion, and the hydroxyl radical. Furthermore, DBA decreased the levels of intracellular reactive oxygen species generated by hydrogen peroxide or UVB treatment of the cells. DBA also decreased the UVB-augmented levels of phospho-histone H2A.X and the extent of comet tail formation, which are both indications of DNA damage. In addition, the compound safeguarded keratinocytes from UVB-induced injury by reversing the production of apoptotic bodies, overturning the disruption of mitochondrial membrane potential, increasing the expression of the anti-apoptotic protein, B-cell lymphoma 2, and decreasing the expression of the pro-apoptotic proteins, Bcl-2-associated X and cleaved caspase-3. Taken together, these results demonstrate that DBA isolated from a green alga protects human keratinocytes against UVB-induced oxidative stress and apoptosis.
    Applied biochemistry and biotechnology 01/2014; · 1.94 Impact Factor
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    ABSTRACT: Clinical stage of gastric cancer is currently assessed by computed tomography. Accurate clinical staging is important for the tailoring of therapy. This study evaluated the accuracy of clinical N staging using stomach protocol computed tomography. Between March 2004 and November 2012, 171 patients with gastric cancer underwent preoperative stomach protocol computed tomography (Jeju National University Hospital; Jeju, Korea). Their demographic and clinical characteristics were reviewed retrospectively. Two radiologists evaluated cN staging using axial and coronal computed tomography images, and cN stage was matched with pathologic results. The diagnostic accuracy of stomach protocol computed tomography for clinical N staging and clinical characteristics associated with diagnostic accuracy were evaluated. The overall accuracy of stomach protocol computed tomography for cN staging was 63.2%. Computed tomography images of slice thickness 3.0 mm had a sensitivity of 60.0%; a specificity of 89.6%; an accuracy of 78.4%; and a positive predictive value of 78.0% in detecting lymph node metastases. Underestimation of cN stage was associated with larger tumor size (P<0.001), undifferentiated type (P=0.003), diffuse type (P=0.020), more advanced pathologic stage (P<0.001), and larger numbers of harvested and metastatic lymph nodes (P<0.001 each). Tumor differentiation was an independent factor affecting underestimation by computed tomography (P=0.045). Computed tomography with a size criterion of 8 mm is highly specific but relatively insensitive in detecting nodal metastases. Physicians should keep in mind that computed tomography may not be an appropriate tool to detect nodal metastases for choosing appropriate treatment.
    Journal of gastric cancer. 09/2013; 13(3):149-56.
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    ABSTRACT: A 32-year-old male presented with painful swelling of the sinus tarsi that occurred during daily activities. Diagnostic imaging suggested the presence of a large synovial osteochondromatosis that blocked subtalar motion with deformity of the adjacent bone. The large bony mass was excised, and normal subtalar motion was achieved.
    The Journal of foot and ankle surgery: official publication of the American College of Foot and Ankle Surgeons 01/2013;
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    ABSTRACT: Clinical staging of gastric cancer appears to be important more and more for tailored therapy. This study aimed to verify the accuracy of clinical T staging in a low-volume institute. We retrospectively reviewed prospectively collected data of gastric cancer patients who underwent resection. A total of 268 patients of gastric cancer were enrolled from March 2004 to June 2012. These demographics, tumor characteristics, and clinical stages were analyzed for identification of diagnostic value of clinical T staging. The predictive values for pT1 of endoscopy and computed tomography were 90.0% and 89.4%, respectively. In detail, the predictive values of endoscopy for pT1a, pT1b, and pT2 or more were 87%, 58.5%, and 90.6%, respectively. The predictive values of computed tomography for pT1a, pT1b, and pT2 or more were 68.8%, 73.9%, and 84.4%, respectively. The factors leading to underestimation of pT2 or more lesions by gastroscopy were the middle third location, the size greater than 2 cm, and younger age. Those for overestimation of pT1 lesion by computed tomography were male, age more than 70 years, elevated type, and size greater than 3 cm. Diagnostic accuracy of early gastric cancer was 90%, which is comparable to those of high volume center. In patients with early gastric cancer, limited gastrectomy or minimal invasive surgery can be safely introduced at a low volume center also. However, the surgeon of low-volume institute should consider the accuracy of clinical staging before extending the indication of limited treatment.
    Journal of gastric cancer. 12/2012; 12(4):223-31.
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    ABSTRACT: Paratesticular rhabdomyosarcoma is a rare malignancy arising from the mesenchymal tissues of the spermatic cord, epididymis, testis, and testicular tunica, and accounts for approximately 7% of all rhabdomyosarcomas. It often occurs in children but is known to have a better prognosis than disease at other urogenital sites. Patients typically present with painless unilateral scrotal swelling like a solid testicular tumor. However, we report an unusual case of delayed diagnosis of paratesticular rhabdomyosarcoma accompanied by epididymitis manifesting an painful scrotal swelling.
    The world journal of men's health. 08/2012; 30(2):146-9.
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    ABSTRACT: We found a case of hypoplasia of vertebral artery with fibromuscular dysplasia in an 82-yr-old Korean female cadaver during a routine dissection course. In the present case, intracranial hypoplasia in left vertebral artery and bilateral origin of posterior inferior cerebellar artery at the vertebrobasilar junction were recognized. Histopathologically, left vertebral artery showed intimal type of fibromuscular dysplasia both in its extracranial and intracranial courses. These results indicate that the association of fibromuscular dysplasia and hypoplasia does exist in the vertebral artery, although the etiologies are not verified yet.
    Journal of Korean medical science 07/2012; 27(7):811-3. · 0.84 Impact Factor
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    ABSTRACT: Heme oxygenase-1 (HO-1) catabolizes heme into carbon monoxide, biliverdin, and free iron which mediate its protective effect against oxidative stress. The aim of the present study was to determine the expression level and activity of HO-1 in Korean colon cancer tissues and cell lines. HO-1 protein expression was higher (>1.5-fold) in tumor tissues than in adjacent normal tissues in 14 of 20 colon cancer patients, and HO-1 protein expression was closely correlated with HO-1 enzyme activity in cancer tissues. Immunohistochemical data confirmed that HO-1 protein was expressed at a higher level in colon cancer tissues than in normal mucosa. Furthermore, HO-1 mRNA and protein expression and enzyme activity were higher in the colon cancer cell lines Caco-2, SNU-407, SNU-1033, HT-29, and SW-403 than in the normal fetal human colon cell line FHC. Treatment with the HO-1 inhibitor zinc protoporphyrin decreased the viability of colon cancer cell lines. These data indicate that HO-1 may serve as a clinically useful biomarker of colon cancer and as a target for anticolon cancer drugs.
    Tumor Biology 02/2012; 33(4):1031-8. · 2.52 Impact Factor
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    ABSTRACT: We observed that (1S,2S,3E,7E,11E)-3,7,11,15-Cembratetraen-17,2-olide (LS-1), marine cembrenolide diterpene, inhibited growth and induced apoptosis in colon cancer cells via a reactive oxygen species (ROS) dependent mechanism. Treatment of HT-29 cells with LS-1 resulted in ROS generation, which was accompanied by disruption of mitochondrial membrane potential, cytosolic release of cytochrome c, sub-G1 peak accumulation, activation of Bid, caspase-3, -8, and -9, and cleavage of poly(ADP-ribose) polymerase (PARP) along with the suppressive expression of B cell lymphoma-2 (Bcl-2). All these effects were significantly blocked on pretreatment with the ROS inhibitor N-acetylcysteine (NAC), indicating the involvement of increased ROS in the proapoptotic activity of LS-1. Moreover, we showed that LS-1 induced the phosphorylation of c-Jun N-terminal kinase (JNK) and dephosphorylation of p38, extracellular signal-regulated kinase (ERK), Akt, Src and signal transducer and activator of transcription (STAT)3, which were effectively attenuated by NAC. In addition, the expressions of antioxidant catalase and glutathione peroxidase were abrogated by treatment using LS-1 with or without NAC. These findings reveal the novel anticancer efficacy of LS-1 mediated by the induction of apoptosis via ROS generation in human colon cancer cells.
    Biological & Pharmaceutical Bulletin 01/2012; 35(7):1054-63. · 1.85 Impact Factor
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    ABSTRACT: Metastasis to the thyroid gland from distant cancer is rare, and, in some cases, is a diagnostic challenge. Here, we report a case of metastatic renal cell carcinoma of the thyroid gland. A 77-year-old man presented with a neck mass detected about 1 month previously. He had undergone a right nephrectomy owing to renal cell carcinoma 14 years previously. Fine needle aspiration cytology showed a few atypical follicular cells with nuclear atypia. Under a tentative diagnosis of papillary thyroid carcinoma, a total thyroidectomy was performed. The histologic and immunohistochemical studies of the surgical specimens indicated that the thyroid masses were metastatic renal cell carcinoma to the thyroid.
    Chonnam medical journal. 08/2011; 47(2):130-3.
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    The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 06/2011; 57(6):384-7.
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    ABSTRACT: To evaluate seven molecular markers including cyclooxygenase -2, epidermal growth factor receptor, Ki-67, p21, survivin, thymidylate synthase, and vascular endothelial growth factor for prediction of response to preoperative chemoradiotherapy in locally advanced rectal cancer. Fifty-four patients with clinical T3-4 and/or node-positive rectal cancer who underwent preoperative chemoradiotherapy followed by surgical resection were enrolled into this study. Preoperative chemoradiotherapy consisted of 50.4 Gy of pelvic irradiation with concomitant 5-fluorouracil or oral capecitabine. Expression of molecular markers in pretreatment paraffin-embedded tumor biopsy specimens was assessed by immunohistochemical staining on the tissue microarray. Tumor downstaging was used as an endpoint for evaluation of tumor response. Tumor downstaging was observed in 22 patients (41%), and pathologic complete remission in 7 patients (13%). Among seven molecular markers, only survivin expression was significantly related with tumor downstaging: 26% with high survivin expression (>75% in extent) vs. 72% with low survivin expression (p = 0.0011). However, other six molecular markers were found not to have any correlation with tumor downstaging. High survivin expression in pretreatment tumor biopsy was associated with less tumor downstaging after preoperative chemoradiotherapy for locally advanced rectal cancer.
    International Journal of Colorectal Disease 03/2011; 26(8):1019-23. · 2.24 Impact Factor