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Coffin CS, Lee SS. Editorial: Anti-viral therapy for prevention of perinatal HBV transmission--extending therapy beyond birth and the risk of post-partum flare. Aliment Pharmacol Ther 2014; 40:115-6. [PMID: 24903430 DOI: 10.1111/apt.12793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 04/21/2014] [Indexed: 12/08/2022]
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Shim S, Jang WS, Lee SJ, Jin S, Kim J, Lee SS, Bang HY, Jeon BS, Park S. Development of a new minipig model to study radiation-induced gastrointestinal syndrome and its application in clinical research. Radiat Res 2014; 181:387-95. [PMID: 24786169 DOI: 10.1667/rr13207.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Because of insufficient clinical data regarding acute radiation damage after single high-dose radiation exposure, acute radiation-induced gastrointestinal (GI) syndrome remains difficult to treat. The goal of this study was to establish an appropriate and efficient minipig model to study high-dose radiation-induced GI syndrome after radiation exposure. For endoscopic access to the ileum, ileocutaneous anastomosis was performed 3 weeks before irradiation in six male Göttingen minipigs. Minipigs were locally irradiated at the abdominal area using a gamma source as follows: 1,000 cGy (n = 3) and 1,500 cGy (n = 3). Endoscopic evaluation for the terminal ileum was periodically performed via the ileocutaneous anastomosis tract. Pieces of tissue were serially taken for histological examination. The irradiated intestine presented characteristic morphological changes over time. The most obvious changes in the ileum were mucosal atrophy and telangiectasia from day 1 to day 17 after abdominal irradiation. Microscopic findings were characterized as architectural disorganization, loss of villi and chronic active inflammation. Increase in cyclooxygenase-2 (COX-2) expression was closely correlated with severity of tissue damage and inflammation. Particularly, the plasma citrulline level (PCL), a potential marker for radiation-induced intestinal damage, was significantly decreased the day after irradiation and recovered when irradiated mucosa was normalized. Our results also showed that PCL changes were positively correlated with microscopic changes and the endoscopic score in radiation-induced mucosal damage. In conclusion, the ileocutaneous anastomosis model using the minipig mimics human GI syndrome and allows the study of sequential changes in the ileum, the main target tissue of abdominal irradiation. In addition, PCL could be a simple biomarker for radiation-induced intestinal damage.
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Kim JS, Rhim KJ, Jang WS, Lee SJ, Son Y, Lee SS, Park S, Lim SM. β-irradiation (¹⁶⁶Ho patch)-induced skin injury in mini-pigs: effects on NF-κB and COX-2 expression in the skin. J Vet Sci 2014; 16:1-9. [PMID: 24962420 PMCID: PMC4367138 DOI: 10.4142/jvs.2015.16.1.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/19/2014] [Indexed: 11/20/2022] Open
Abstract
In the present study, the detrimental effect of β-emission on pig skin was evaluated. Skin injury was modeled in mini-pigs by exposing the animals to 50 and 100 Gy of β-emission delivered by 166Ho patches. Clinicopathological and immunohistochemical changes in exposed skin were monitored for 18 weeks after β-irradiation. Radiation induced desquamation at 2~4 weeks and gradual repair of this damage was evident 6 weeks after irradiation. Changes in basal cell density and skin depth corresponded to clinically relevant changes. Skin thickness began to decrease 1 week after irradiation, and the skin was thinnest 4 weeks after irradiation. Skin thickness increased transiently during recovery from irradiation-induced skin injury, which was evident 6~8 weeks after irradiation. Epidermal expression of nuclear factor-kappa B (NF-κB) differed significantly between the untreated and irradiated areas. One week after irradiation, cyclooxygenase-2 (COX-2) expression was mostly limited to the basal cell layer and scattered among these cells. High levels of COX-2 expression were detected throughout the full depth of the skin 4 weeks after irradiation. These findings suggest that NF-κB and COX-2 play roles in epidermal cell regeneration following β-irradiation of mini-pig skin.
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Naftalin CM, Chan KCW, Wong KH, Cheung SW, Chan RCY, Lee SS. CYP2B6-G516T genotype influences plasma efavirenz concentration in a Hong Kong population, allowing potential individualization of therapy. HIV Med 2014; 15:63-4. [PMID: 24299220 DOI: 10.1111/hiv.12076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Sadler MD, Lee SS. Letter: Treatment of HBeAg+ chronic hepatitis B--is tenofovir truly superior to entecavir? Aliment Pharmacol Ther 2014; 39:1339. [PMID: 24803253 DOI: 10.1111/apt.12732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 12/08/2022]
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106
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Shim S, Jang WS, Lee SJ, Jin S, Kim J, Lee SS, Bang HY, Jeon BS, Park S. Development of a New Minipig Model to Study Radiation-Induced Gastrointestinal Syndrome and its Application in Clinical Research. Radiat Res 2014:140404062615008. [PMID: 24701962 DOI: 10.1667/rt13207.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Because of insufficient clinical data regarding acute radiation damage after single high-dose radiation exposure, acute radiation-induced gastrointestinal (GI) syndrome remains difficult to treat. The goal of this study was to establish an appropriate and efficient minipig model to study high-dose radiation-induced GI syndrome after radiation exposure. For endoscopic access to the ileum, ileocutaneous anastomosis was performed 3 weeks before irradiation in six male Göttingen minipigs. Minipigs were locally irradiated at the abdominal area using a gamma source as follows: 1,000 cGy (n = 3) and 1,500 cGy (n = 3). Endoscopic evaluation for the terminal ileum was periodically performed via the ileocutaneous anastomosis tract. Pieces of tissue were serially taken for histological examination. The irradiated intestine presented characteristic morphological changes over time. The most obvious changes in the ileum were mucosal atrophy and telangiectasia from day 1 to day 17 after abdominal irradiation. Microscopic findings were characterized as architectural disorganization, loss of villi and chronic active inflammation. Increase in cyclooxygenase-2 (COX-2) expression was closely correlated with severity of tissue damage and inflammation. Particularly, the plasma citrulline level (PCL), a potential marker for radiation-induced intestinal damage, was significantly decreased the day after irradiation and recovered when irradiated mucosa was normalized. Our results also showed that PCL changes were positively correlated with microscopic changes and the endoscopic score in radiation-induced mucosal damage. In conclusion, the ileocutaneous anastomosis model using the minipig mimics human GI syndrome and allows the study of sequential changes in the ileum, the main target tissue of abdominal irradiation. In addition, PCL could be a simple biomarker for radiation-induced intestinal damage.
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Choi HS, Kim MJ, Moon CH, Yoon JH, Ku HR, Kang GW, Na II, Lee SS, Lee BC, Park YJ, Kim HI, Ku YH. Medullary thyroid carcinoma with ectopic adrenocorticotropic hormone syndrome. Endocrinol Metab (Seoul) 2014; 29:96-100. [PMID: 24741461 PMCID: PMC3970275 DOI: 10.3803/enm.2014.29.1.96] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 05/07/2013] [Indexed: 11/11/2022] Open
Abstract
Ectopic adrenocorticotropic hormone (ACTH) syndrome is caused most frequently by a bronchial carcinoid tumor or by small cell lung cancer. Medullary thyroid carcinoma (MTC) is a rare etiology of ectopic ACTH syndrome. We describe a case of Cushing syndrome due to ectopic ACTH production from MTC in a 48-year-old male. He was diagnosed with MTC 14 years ago and underwent total thyroidectomy, cervical lymph node dissection and a series of metastasectomies. MTC was confirmed by the pathological examination of the thyroid and metastatic mediastinal lymph node tissues. Two years after his last surgery, he developed Cushingoid features, such as moon face and central obesity, accompanied by uncontrolled hypertension and new-onset diabetes. The laboratory results were compatible with ectopic ACTH syndrome. A bilateral adrenalectomy improved the clinical and laboratory findings that were associated with Cushing syndrome. This is the first confirmed case of ectopic ACTH syndrome caused by MTC in Korea.
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Congly SE, Lee SS. Commentary: the ss469415590 SNP--an IL28B marker looking for a home. Aliment Pharmacol Ther 2014; 39:339. [PMID: 24397320 DOI: 10.1111/apt.12597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 12/08/2022]
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Lee SS. Benefits of early detection and treatment of human immunodeficiency virus infections. Hong Kong Med J 2013; 19:472-3. [DOI: 10.12809/hkmj134162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Ha WH, Park S, Yoo J, Yoon S, Lee SS, Kim JK. Evaluation of sodium activation distribution in the PMMA water phantom after fast neutron irradiation. Appl Radiat Isot 2013; 81:298-301. [DOI: 10.1016/j.apradiso.2013.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 03/09/2013] [Indexed: 11/24/2022]
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Heo I, Park S, Jung CW, Koh JS, Lee SS, Seol H, Choi HS, Cho SY. Fine needle aspiration cytology of parathyroid lesions. KOREAN JOURNAL OF PATHOLOGY 2013; 47:466-71. [PMID: 24255635 PMCID: PMC3830994 DOI: 10.4132/koreanjpathol.2013.47.5.466] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/09/2013] [Accepted: 09/27/2013] [Indexed: 01/10/2023]
Abstract
Background There has been an increase in the use of fine needle aspiration cytology (FNAC) for the diagnosis of parathyroid lesions (PLs). Differentiation between a thyroid lesion and a PL is not easy because of their similar features. We reviewed parathyroid aspirates in our institution and aimed to uncover trends in diagnostic criteria. Methods We selected 25 parathyroid aspirates (from 6 men and 19 women) confirmed surgically or immunohistochemically from 2006 to 2011. Results Major architectural findings of PLs include scattered naked nuclei, loose clusters, a papillary pattern with a fibrovascular core, tight clusters, and a follicular pattern. These architectures were commonly admixed with one another. Cytological features included anisokaryosis, stippled chromatin, a well-defined cell border, and oxyphilic cytoplasm. Eighteen of the 25 patients were diagnosed with PL using FNAC. Seven patients had been misdiagnosed with atypical cells (n=2), benign follicular cells (n=2), adenomatous goiter (n=2) and metastatic carcinoma (n=1) in FNAC. Using clinicoradiologic data, the sensitivity of the cytological diagnosis was 86.7%. The cytological sensitivity decreased to 50% without this information. Conclusions FNAC of PL is easily confused with thyroid lesions. A combination of cytological parameters and clinical data will be required to improve the diagnostic sensitivity of PLs.
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Haam SJ, Lee SS, Lee DY, Paik HC. The effects of the climatic elements on occurrence of the spontaneous pneumothorax. J Cardiothorac Surg 2013. [PMCID: PMC3845070 DOI: 10.1186/1749-8090-8-s1-p153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
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Kim SJ, Kang HJ, Kim JS, Eom HS, Huh J, Ko YH, Lee J, Yim DS, Lee SY, Park WS, Yang WI, Lee SS, Suh C, Kim WS. A phase I study of everolimus and CHOP in newly diagnosed peripheral T-cell lymphomas. Invest New Drugs 2013; 31:1514-21. [PMID: 23975510 DOI: 10.1007/s10637-013-0015-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 08/16/2013] [Indexed: 01/14/2023]
Abstract
BACKGROUND We performed a phase I study to determine the dose and safety of everolimus as a combination chemotherapy in peripheral T-cell lymphoma (PTCL). METHODS Four dose levels (2.5 to 10 mg) of everolimus from days 1 to 14 with CHOP (750 mg/m(2) cyclophosphamide, 50 mg/m(2) doxorubicin, and 1.4 mg/m(2) (maximum 2 mg) vincristine on day 1, and 100 mg/day prednisone on days 1 to 5) every 21 days were planned. RESULTS Fifteen patients newly diagnosed with stage III/IV PTCL were enrolled. One of 6 patients at dose level 2 (5 mg everolimus) had grade 3 hepatotoxicity and 3 of 6 patients at level 3 (7.5 mg everolimus) had grade 4 hematologic toxicities (two grade 4 thrombocytopenia and one grade 4 neutropenia with fever lasting more than 3 days). The recommended dose of everolimus for combination was 5 mg. There were no differences in steady state trough concentrations of everolimus between cycles 1 and 2 for all three dose levels. All evaluable patients achieved response (8 complete and 6 partial). CONCLUSIONS Everolimus (5 mg) can be safely combined with CHOP leading to a feasible and effective regimen for PTCL. The subsequent phase II is now in progress.
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Lee TH, Moon JH, Kim JH, Park DH, Lee SS, Choi HJ, Cho YD, Park SH, Kim SJ. Primary and revision efficacy of cross-wired metallic stents for endoscopic bilateral stent-in-stent placement in malignant hilar biliary strictures. Endoscopy 2013; 45:106-13. [PMID: 23212727 DOI: 10.1055/s-0032-1325928] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND STUDY AIMS Endoscopic bilateral drainage for inoperable malignant hilar biliary strictures (HBS) using metal stents is considered to be technically difficult. Furthermore, endoscopic revision of bilateral stenting after occlusion can be challenging. This study was performed to evaluate the long-term efficacy of endoscopic bilateral stent-in-stent placement of cross-wired metallic stents in high-grade malignant HBS and planned endoscopic bilateral revision. PATIENTS AND METHODS A total of 84 patients with inoperable high-grade malignant HBS were enrolled from three academic tertiary referral centers. Two cross-wired metal stents were inserted using a bilateral stent-in-stent placement method. Bilateral endoscopic revision was also performed during follow-up using either identical metal stents or plastic stents. The main outcome measurements were technical and functional success, complications, stent patency, and endoscopic revision efficacy. RESULTS The technical and clinical success rates of endoscopic bilateral stent-in-stent placement of cross-wired metallic stents were 95.2% (80/84) and 92.9% (78/84), respectively. Median patency (range) and survival were 238 days (10-429) and 256 days (10-1130), respectively. Obstruction of primary bilateral stents occurred in 30.8% (24/78) of patients with functionally successful stent placement. The technical and clinical success rates of planned bilateral endoscopic revision for occluded stents were 83.3% (20/24) and 79.2% (19/24), respectively. For revision, bilateral metallic stents were placed in 11 patients (55.0%); the remaining patients received plastic stents. CONCLUSIONS Palliative endoscopic bilateral stent-in-stent placement of cross-wired metallic stents was effective in patients with inoperable HBS. Revision endoscopic bilateral stenting may be feasible and successful in cases where the primary deployed metal stents are occluded.
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Liu Y, Wang HH, Bian G, Zhang Z, Lee SS, Fenter PA, Tischler JZ, Hong H, Chiang TC. Interfacial bonding and structure of Bi2Te3 topological insulator films on Si(111) determined by surface x-ray scattering. PHYSICAL REVIEW LETTERS 2013; 110:226103. [PMID: 23767736 DOI: 10.1103/physrevlett.110.226103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/25/2013] [Indexed: 06/02/2023]
Abstract
Interfacial topological states are a key element of interest for topological insulator thin films, and their properties can depend sensitively on the atomic bonding configuration. We employ in situ nonresonant and resonant surface x-ray scattering to study the interfacial and internal structure of a prototypical topological film system: Bi2Te3 grown on Si(111). The results reveal a Te-dominated buffer layer, a large interfacial spacing, and a slightly relaxed and partially strained bottom quintuple layer of an otherwise properly stacked bulklike Bi2Te3 film. The presence of the buffer layer indicates a nontrivial process of interface formation and a mechanism for electronic decoupling between the topological film and the Si(111) substrate.
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Kim A, Lee SS, Kim C, Kim EM, Shin DY, Lee SJ, Park S. Abstract 939: Double mutation of KRAS and PIK3CA affects the efficacy of NVP-BEZ235, a dual PI3K/mTOR inhibitor, in regulating the PI3K/mTOR pathway in colorectal cancer. Cancer Res 2013. [DOI: 10.1158/1538-7445.am2013-939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Colorectal cancer (CRC) with mutational activation of KRAS is observed frequently. In addition, PIK3CA mutations commonly coexist with KRAS mutations and lead to additive activation of the PI3K/mTOR signaling pathway. Here, we investigated how CRC cells that harbor KRAS and PIK3CA mutations affect sensitivity to inhibition of PI3K/mTOR with NVP-BEZ235 (BEZ235). We selected CRC patient samples and assessed their mutational status.
CRC patients with KRAS or PIK3CA mutations show activation of Akt and mTOR, particularly when KRAS and PIK3CA mutations coexist. Suppression of PI3K/mTOR by BEZ235 results in a growth inhibitory effect and enhanced apoptosis via Bim activation in KRAS mutant cells. Mutational activation of KRAS when accompanied by a PIK3CA mutation converges at PI3K/mTOR pathway activation, resulting in resistance to BEZ235. Bim knockdown blocked the apoptotic response to BEZ235 in KRAS mutant cells, suggesting that PI3K inhibition leads to Bim accumulation. Moreover, BEZ235 treatment resulted in induction of FOXO3a activity and its induced transcription of Bim activation, which sensitized cells to cytotoxic agents leading to apoptosis in double mutant cells in vitro and in vivo. Taken together, our data suggest that targeting PI3K/mTOR sensitizes cells to apoptosis, implying that activation of PI3K/mTOR signaling via KRAS or PIK3CA mutation is an important pathway in CRC cell growth. Based on these results, coexistent KRAS and PIK3CA mutations confer resistance to BEZ235 via suppression of Bim-induced apoptosis, suggesting that combined treatment with conventional chemoagents is a potential strategy in the clinic.
Citation Format: Areumnuri Kim, Seung-Sook Lee, Cherin Kim, Eun Mi Kim, Dong-Yeop Shin, Sun-Joo Lee, Sunhoo Park. Double mutation of KRAS and PIK3CA affects the efficacy of NVP-BEZ235, a dual PI3K/mTOR inhibitor, in regulating the PI3K/mTOR pathway in colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 939. doi:10.1158/1538-7445.AM2013-939
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Kim A, Lee JE, Lee SS, Kim C, Lee SJ, Jang WS, Park S. Coexistent mutations of KRAS and PIK3CA affect the efficacy of NVP-BEZ235, a dual PI3K/MTOR inhibitor, in regulating the PI3K/MTOR pathway in colorectal cancer. Int J Cancer 2013; 133:984-96. [PMID: 23475782 DOI: 10.1002/ijc.28073] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 01/08/2013] [Indexed: 12/29/2022]
Abstract
Colorectal cancer (CRC) with mutational activation of KRAS is observed frequently. In addition, PIK3CA mutations commonly coexist with KRAS mutations and lead to additive activation of the PI3K/MTOR signaling pathway. Here, we investigated how CRC cells that harbor KRAS and PIK3CA mutations affect sensitivity to inhibition of PI3K/MTOR with NVP-BEZ235 (BEZ235). We selected CRC patient samples and assessed their mutational status. CRC patients with KRAS or PIK3CA mutations show activation of AKT and MTOR, particularly when KRAS and PIK3CA mutations coexist. Suppression of PI3K/MTOR by BEZ235 results in a growth inhibitory effect and enhanced apoptosis via BIM activation in KRAS mutant cells. Mutational activation of KRAS when accompanied by a PIK3CA mutation converges at PI3K/MTOR pathway activation, resulting in resistance to BEZ235. BIM knockdown blocked the apoptotic response to BEZ235 in KRAS mutant cells, suggesting that PI3K inhibition leads to BIM accumulation. Moreover, BEZ235 treatment resulted in induction of FOXO3A activity and its induced transcription of BIM activation, which sensitized cells to cytotoxic agents leading to apoptosis in double mutant cells in vitro and in vivo. Taken together, our data suggest that targeting PI3K/MTOR sensitizes cells to apoptosis, implying that activation of PI3K/MTOR signaling via KRAS or PIK3CA mutation is an important pathway in CRC cell growth. Based on these results, coexistent KRAS and PIK3CA mutations confer resistance to BEZ235 via suppression of BIM-induced apoptosis, suggesting that combined treatment with conventional chemoagents is a potential strategy in the clinic.
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Chen Y, Lee B, Yi HT, Lee SS, Payne MM, Pola S, Kuo CH, Loo YL, Anthony JE, Tao YT, Podzorov V. Dynamic character of charge transport parameters in disordered organic semiconductor field-effect transistors. Phys Chem Chem Phys 2013; 14:14142-51. [PMID: 22868385 DOI: 10.1039/c2cp41823a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this perspective article, we discuss the dynamic instability of charge carrier transport in a range of popular organic semiconductors. We observe that in many cases field-effect mobility, an important parameter used to characterize the performance of organic field-effect transistors (OFETs), strongly depends on the rate of the gate voltage sweep during the measurement. Some molecular systems are so dynamic that their nominal mobility can vary by more than one order of magnitude, depending on how fast the measurements are performed, making an assignment of a single mobility value to devices meaningless. It appears that dispersive transport in OFETs based on disordered semiconductors, those with a high density of localized trap states distributed over a wide energy range, is responsible for the gate voltage sweep rate dependence of nominal mobility. We compare such rate dependence in different materials and across different device architectures, including pristine and trap-dominated single-crystal OFETs, as well as solution-processed polycrystalline thin-film OFETs. The paramount significance given to a single mobility value in the organic electronics community and the practical importance of OFETs for applications thus suggest that such an issue, previously either overlooked or ignored, is in fact a very important point to consider when engaging in fundamental studies of charge carrier mobility in organic semiconductors or designing applied circuits with organic semiconductors.
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Shim S, Lee SB, Lee JG, Jang WS, Lee SJ, Park S, Lee SS. Mitigating effects of hUCB-MSCs on the hematopoietic syndrome resulting from total body irradiation. Exp Hematol 2013; 41:346-53.e2. [PMID: 23333483 DOI: 10.1016/j.exphem.2013.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 12/26/2012] [Accepted: 01/04/2013] [Indexed: 12/20/2022]
Abstract
This study evaluated the clinical and pathologic effects of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in the recovery from total body irradiation by comparing it with the effects of granulocyte-colony stimulating factor (G-CSF), an efficacious drug in the treatment of acute bone marrow radiation syndrome. BALB/c mice were treated with G-CSF or hUCB-MSCs after they were irradiated with 7 Gy cobalt-60 γ-rays. Circulating blood counts, histopathologic changes in the bone marrow, and plasma level of Flt-3L and transforming growth factor (TGF-β1) were monitored in the postirradiation period. Hematologic analysis revealed that the peripheral leukocyte counts were markedly increased in the hUCB-MSCs-treated group, whereas G-CSF-treated mice did not recover significantly. Moreover, differential counts showed that hUCB-MSC treatment has regenerative effects on white blood cells, lymphocytes, and monocytes compared with the irradiated group. Treatment with hUCB-MSCs or G-CSF significantly increased immunoreactivity of Ki-67 until 3 weeks after total body irradiation. However, at 3 weeks, the number of Ki-67 immunoreactive cells significantly increased in the hUCB-MSCs-treated group compared with the G-CSF-treated group. Furthermore, hUCB-MSC treatment significantly modulated plasma levels of the hematopoietic cytokines Flt-3L and TGF-β1, whereas G-CSF treatment failed to decrease the plasma Flt-3L levels at 2 weeks after irradiation. Based on the differences in circulating blood cell reconstitution and cell density of bone marrow, the authors suggest that MSC treatment is superior to G-CSF treatment for hematopoietic reconstitution following sublethal dose radiation exposure.
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Choi HS, Seol H, Heo IY, Jung CW, Cho SY, Park S, Koh JS, Lee SS. Fine-needle aspiration cytology of pleomorphic carcinomas of the lung. KOREAN JOURNAL OF PATHOLOGY 2013; 46:576-82. [PMID: 23323109 PMCID: PMC3540336 DOI: 10.4132/koreanjpathol.2012.46.6.576] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 10/18/2012] [Accepted: 10/19/2012] [Indexed: 01/29/2023]
Abstract
Background Pleomorphic carcinoma (PC) is a rare pulmonary malignancy. Because of its rarity and histological heterogeneity, cytopathologists might suspect PC only rarely on the basis of its cytological specimen. In addition, cytological findings from fine needle aspiration (FNA) specimens have rarely been described. Hence, we investigated the cytological features of FNA in the cases of PC. Methods We reviewed 7 FNA specimens of PC. The patients had undergone surgical resection at the Korea Cancer Center Hospital between 2007 and 2011. The cytological features of PC were assessed and compared with the histopathological features of the corresponding surgical specimen. Immunocytochemical analysis with cytokeratin and vimentin was performed on the cell blocks. Results The tumor cells were either dispersed or arranged in loose aggregates, and generally lacked any glandular or squamous differentiation. Pleomorphic or spindle shape tumor cells were observed, and mono-, bi-, or multi-nucleated giant cells were frequently observed. The background showed necrosis and contained numerous lymphocytes and neutrophils. Immunocytochemically, the tumor cells were positive for cytokeratin and vimentin. Conclusions PC displays characteristic cytological features. It might therefore be possible to make an accurate diagnosis of PC by assessing the degree of nuclear atypia.
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Yoon S, Ha WH, Kim MR, Lee SS. Gross Alpha Analysis of Nasal Smear Samples and Internal Dose Assessment Procedure in Radiation Emergency. ACTA ACUST UNITED AC 2012. [DOI: 10.14407/jrp.2012.37.4.226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Mun SK, Lee SS, Kang SH, Lee MJ, Kim SY, Choi HG, Kang HJ. An adult case of severe chronic active Epstein-Barr virus infection with T-cell lymphoproliferative disorder. Korean J Intern Med 2012; 27:474-7. [PMID: 23269893 PMCID: PMC3529251 DOI: 10.3904/kjim.2012.27.4.474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 05/23/2012] [Accepted: 07/09/2012] [Indexed: 12/01/2022] Open
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Lee JK, Han EA, Lee SS, Ha WH, Barquinero JF, Lee HR, Cho MS. Cytogenetic biodosimetry for Fukushima travelers after the nuclear power plant accident: no evidence of enhanced yield of dicentrics. JOURNAL OF RADIATION RESEARCH 2012; 53:876-81. [PMID: 22859566 PMCID: PMC3483860 DOI: 10.1093/jrr/rrs065] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/05/2012] [Accepted: 07/06/2012] [Indexed: 05/22/2023]
Abstract
Individuals who traveled to contaminated areas after the Fukushima nuclear accident have concerns about the health effects. However, medical follow-up for any adverse health effects will be difficult without personal dose measurements. Cytogenetic biodosimetry is a reasonable method of assessing absorbed doses retrospectively. We analyzed dicentric chromosomes for 265 Fukushima travelers, mostly journalists and rescue workers, who had been dispatched to northeastern Japan during the nuclear emergency. As a control group, 37 healthy volunteers who had not visited Japan since the accident were enrolled. Yields of dicentrics and absorbed doses calculated from a dose-response calibration curve for travelers and the control group were compared. The cut-off level for dicentric chromosomes in the controls was 3.5 per 1000 cells. Of the 265 travelers, 31 had elevated numbers of dicentrics (High-Dics group) while 234 were below the cut-off (Normal-Dics group). All but one of the individuals in the High-Dics group also reported a significantly higher number of medical exposures to radiation within the past three years compared with the Normal-Dics or control groups. The 225 travelers with no history of medical exposure showed no difference of dicentrics yield compared to the control group. Our data indicate that Fukushima travel alone did not enhance the yield of dicentrics.
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Kim SY, Shin DY, Lee SS, Suh C, Kwak JY, Kim HG, Lee JH, Lee SI, Lee YR, Kang SH, Mun SK, Lee MJ, Lee HR, Yang SH, Kang HJ. Clinical characteristics and outcomes of primary bone lymphoma in Korea. THE KOREAN JOURNAL OF HEMATOLOGY 2012; 47:213-8. [PMID: 23071477 PMCID: PMC3464339 DOI: 10.5045/kjh.2012.47.3.213] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/08/2012] [Accepted: 09/10/2012] [Indexed: 11/17/2022]
Abstract
Background This study evaluates the effectiveness of immunochemotherapy and radiation therapy in the treatment of patients with primary bone lymphoma (PBL). Methods We retrospectively reviewed the medical records of 33 patients with PBL who were treated at 6 medical centers in Korea from 1992 to 2010. Clinicopathological features and treatment outcomes were analyzed. Results The median age of the patients participating in our study was 40 years. The most common sites of involvement were the pelvis (12.36%) and femur (11.33%). CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) or CHOP-like regimens were administered to 20 patients (61%), and R-CHOP (rituximab plus CHOP) was administered to the remaining 13 patients (39%). The overall response rate was 89% (complete response, 76%; partial response, 12%). The overall survival (OS) of patients with solitary bone lesions was longer than that of patients with multiple bone lesions (median OS: not reached vs. 166 months, respectively; P=0.089). Addition of rituximab to CHOP did not significantly affect either OS or progression-free survival (P=0.53 and P=0.23, respectively). Combining radiation therapy with chemotherapy also did not improve the OS or progression-free survival of patients with solitary bone lesions. Conclusion Conventional cytotoxic chemotherapy remains an effective treatment option for patients with PBL. Additional benefits of supplementing chemotherapy with either rituximab or radiation therapy were not observed in this study. Further investigation is needed to characterize the role of immunochemotherapy in treating patients with PBL.
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Kim JH, Kim SJ, Lee WY, Cheon YH, Lee SS, Ju A, K M, Kim DJ. The Effects of Alcohol Abstinence on BDNF, Ghrelin, and Leptin Secretions in Alcohol-Dependent Patients with Glucose Intolerance. Alcohol Clin Exp Res 2012; 37 Suppl 1:E52-8. [DOI: 10.1111/j.1530-0277.2012.01921.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/02/2012] [Indexed: 01/15/2023]
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