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Kang TW, Kang JG, Jung JW. A Bidirectional Interpolation Method for Post-Processing in Sampling-Based Robot Path Planning. Sensors (Basel) 2021; 21:s21217425. [PMID: 34770732 PMCID: PMC8587826 DOI: 10.3390/s21217425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/30/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022]
Abstract
This paper proposes a post-processing method called bidirectional interpolation method for sampling-based path planning algorithms, such as rapidly-exploring random tree (RRT). The proposed algorithm applies interpolation to the path generated by the sampling-based path planning algorithm. In this study, the proposed algorithm is applied to the path created by RRT-connect and six environmental maps were used for the verification. It was visually and quantitatively confirmed that, in all maps, not only path lengths but also the piecewise linear shape were decreased compared to the path generated by RRT-connect. To check the proposed algorithm's performance, visibility graph, RRT-connect algorithm, Triangular-RRT-connect algorithm and post triangular processing of midpoint interpolation (PTPMI) were compared in various environmental maps through simulation. Based on these experimental results, the proposed algorithm shows similar planning time but shorter path length than previous RRT-like algorithms as well as RRT-like algorithms with PTPMI having a similar number of samples.
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Affiliation(s)
- Tae-Won Kang
- Department of Artificial Intelligence, Dongguk University, Seoul 04620, Korea;
| | - Jin-Gu Kang
- Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea;
| | - Jin-Woo Jung
- Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea;
- Correspondence: ; Tel.: +82-2-2260-3812
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2
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Park SK, Ryoo JH, Kang JG, Jung JY. Association of left ventricular hypertrophy with the level of thyroid hormone in euthyroid state. J Endocrinol Invest 2021; 44:111-117. [PMID: 32383145 DOI: 10.1007/s40618-020-01277-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE It has been demonstrated that variation in thyroid hormone levels even within normal range was associated with increased cardiovascular risk. However, available data are still insufficient on association between left ventricular hypertrophy (LVH) and thyroid hormone levels within euthyroid state. METHODS In 69,298 Koreans with euthyroid function, we evaluated association between echocardiographically detected LVH and thyroid hormone levels within the normal range. Study participants were categorized into elderly (age ≥ 40) and younger (age < 40) groups, where subjects were divided into four groups according to quartile levels of thyroxine (FT4), triiodothyronine (FT3), and thyroid-stimulating hormone (TSH). Multivariable adjusted logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence interval (CI) for LVH (adjusted ORs [95% CI]) across quartile levels of thyroid hormones. RESULTS In elderly group, adjusted ORs for LVH generally higher in the first quartile group than other quartile groups, despite no statistical significance in some cases (first quartile: reference, second quartile: 0.86 [0.67-1.11] in TSH, 0.75 [0.58-0.95] in FT4 and 0.63 [0.49-0.81] in FT3, third quartile: 0.70 [0.54-0.92] in TSH, 0.79 [0.61-1.02] in FT4 and 0.72 [0.55-0.93] in FT3, fourth quartile: 0.81 [0.65-1.04] in TSH, 0.85 [0.65-1.10] in FT4 and 0.58 [0.44-0.77] in FT3). This finding was similarly found in the younger group, despite discrepancy in some cases. CONCLUSION In euthyroid state, low normal levels in FT4, FT3 and TSH were more strongly associated with LVH.
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Affiliation(s)
- S K Park
- Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jae-Hong Ryoo
- Department of Occupational and Environmental Medicine, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - J G Kang
- Total Healthcare Center, KangBuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - J Y Jung
- Total Healthcare Center, KangBuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea.
- School of Medicine, Sungkyunkwan University, Seoul, Korea.
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Kang JG, Lim DW, Jung JW. Energy-Efficient Forest Fire Prediction Model Based on Two-Stage Adaptive Duty-Cycled Hybrid X-MAC Protocol. Sensors (Basel) 2018; 18:s18092960. [PMID: 30189668 PMCID: PMC6165158 DOI: 10.3390/s18092960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/02/2018] [Accepted: 09/03/2018] [Indexed: 11/25/2022]
Abstract
This paper proposes an adaptive duty-cycled hybrid X-MAC (ADX-MAC) protocol for energy-efficient forest fire prediction. The Asynchronous sensor network protocol, X-MAC protocol, acquires additional environmental status details from each forest fire monitoring sensor for a given period, and then changes the duty-cycle sleep interval to efficiently calculate forest fire occurrence risk according to the environment. Performance was verified experimentally, and the proposed ADX-MAC protocol improved throughput by 19% and was 24% more energy efficient compared to the X-MAC protocol. The duty-cycle was shortened as forest fire probability increased, ensuring forest fires were detected at faster cycle rate.
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Affiliation(s)
- Jin-Gu Kang
- Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea.
| | - Dong-Woo Lim
- Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea.
| | - Jin-Woo Jung
- Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea.
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Kim SH, Kang JG, Kim CS, Ihm SH, Choi MG, Yoo HJ, Lee SJ. Gemigliptin, a novel dipeptidyl peptidase-IV inhibitor, exerts a synergistic cytotoxicity with the histone deacetylase inhibitor PXD101 in thyroid carcinoma cells. J Endocrinol Invest 2018; 41:677-689. [PMID: 29147952 DOI: 10.1007/s40618-017-0792-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/02/2017] [Indexed: 02/08/2023]
Abstract
PURPOSE The influence of the dipeptidyl peptidase-IV inhibitor gemigliptin alone or in combination with the histone deacetylase inhibitor PXD101 on survival of thyroid carcinoma cells was investigated. METHODS SW1736, TPC-1, 8505C and BCPAP human thyroid carcinoma cells were used. To assess cell survival, cell viability, the percentage of viable cells and dead cells, cytotoxic activity, ATP levels and FACS analysis were measured. To validate the impact of gemigliptin combined with PXD101, the interactions were estimated by obtaining combination index in cells treated with two agents. RESULTS In cells treated with gemigliptin or PXD101, cell viability, the percentage of viable cells and ATP levels were reduced, and the percentage of dead cells and cytotoxic activity were elevated. In cells treated with both gemigliptin and PXD101, compared with PXD101 alone, cell death was augmented, and all of the combination index values were lower than 1.0, suggesting the synergism between gemigliptin and PXD101. The percentage of apoptotic cells, and the protein levels of Bcl2 and cleaved poly (ADP-ribose) polymerase were elevated, and the protein levels of xIAP and survivin were reduced. The protein levels of phospho-Akt and phospho-AMPK were elevated, and cell migration was reduced. CONCLUSIONS Our results demonstrate that gemigliptin induces cytotoxicity in thyroid carcinoma cells. Moreover, gemigliptin has a synergistic activity with PXD101 in the induction of cell death through involvement of Bcl2 family proteins, xIAP and survivin as well as mediation of Akt and AMPK in thyroid carcinoma cells.
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Affiliation(s)
- S H Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - J G Kang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - C S Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - S-H Ihm
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - M G Choi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - H J Yoo
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - S J Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea.
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Jo JW, Kim J, Kim KT, Kang JG, Kim MG, Kim KH, Ko H, Kim J, Kim YH, Park SK. Highly stable and imperceptible electronics utilizing photoactivated heterogeneous sol-gel metal-oxide dielectrics and semiconductors. Adv Mater 2015; 27:1182-1188. [PMID: 25580710 DOI: 10.1002/adma.201404296] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/05/2014] [Indexed: 06/04/2023]
Abstract
Incorporation of Zr into an AlOx matrix generates an intrinsically activated ZAO surface enabling the formation of a stable semiconducting IGZO film and good interfacial properties. Photochemically annealed metal-oxide devices and circuits with the optimized sol-gel ZAO dielectric and IGZO semiconductor layers demonstrate the high performance and electrically/mechanically stable operation of flexible electronics fabricated via a low-temperature solution process.
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Affiliation(s)
- Jeong-Wan Jo
- School of Electrical and Electronic Engineering, Chung-Ang University, Seoul, South Korea
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Lee GH, Kwon SJ, Park KS, Kang JG, Park JG, Lee S, Kim JC, Shim HW, Kim DW. Germanium microflower-on-nanostem as a high-performance lithium ion battery electrode. Sci Rep 2014; 4:6883. [PMID: 25363317 PMCID: PMC4217107 DOI: 10.1038/srep06883] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 10/09/2014] [Indexed: 12/15/2022] Open
Abstract
We demonstrate a new design of Ge-based electrodes comprising three-dimensional (3-D) spherical microflowers containing crystalline nanorod networks on sturdy 1-D nanostems directly grown on a metallic current collector by facile thermal evaporation. The Ge nanorod networks were observed to self-replicate their tetrahedron structures and form a diamond cubic lattice-like inner network. After etching and subsequent carbon coating, the treated Ge nanostructures provide good electrical conductivity and are resistant to gradual deterioration, resulting in superior electrochemical performance as anode materials for LIBs, with a charge capacity retention of 96% after 100 cycles and a high specific capacity of 1360 mA h g(-1) at 1 C and a high-rate capability with reversible capacities of 1080 and 850 mA h g(-1) at the rates of 5 and 10 C, respectively. The improved electrochemical performance can be attributed to the fast electron transport and good strain accommodation of the carbon-filled Ge microflower-on-nanostem hybrid electrode.
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Affiliation(s)
- Gwang-Hee Lee
- 1] Institute for Multi-Convergence of Matter (IMCM), Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea [2] School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 136-713, Korea
| | - S Joon Kwon
- Institute for Multi-Convergence of Matter (IMCM), Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - Kyung-Soo Park
- Institute for Multi-Convergence of Matter (IMCM), Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - Jin-Gu Kang
- Institute for Multi-Convergence of Matter (IMCM), Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - Jae-Gwan Park
- Institute for Multi-Convergence of Matter (IMCM), Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - Sungjun Lee
- Division of Physical Metrology, Korea Research Institute of Standards and Science, Daejeon 305-340, Korea
| | - Jae-Chan Kim
- School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 136-713, Korea
| | - Hyun-Woo Shim
- School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 136-713, Korea
| | - Dong-Wan Kim
- School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 136-713, Korea
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Hwang YC, Kang JG, Ahn KJ, Cha BS, Ihm SH, Lee S, Kim M, Lee BW. The glycemic efficacies of insulin analogue regimens according to baseline glycemic status in Korean patients with type 2 diabetes: sub-analysis from the A(1)chieve(®) study. Int J Clin Pract 2014; 68:1338-44. [PMID: 25284679 PMCID: PMC4491346 DOI: 10.1111/ijcp.12482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIMS In this study, we compared the glucose-lowering effectiveness of insulin analogues and their combination according to baseline glycemic status in patients with type 2 diabetes (T2D) from the A1 chieve(®) study conducted in Korea. METHODS This sub-analysis from the A1 chieve(®) study was a 24-week prospective, multicenter, non-interventional, open-labelled study. Of the 4058 patients, 3074 patients who had their HbA1c level measured at baseline were included in this sub-analysis. We classified patients into three groups according to baseline HbA1c levels: group I (HbA1c < 7.5%), group II (7.5% ≤ HbA1c < 9.0%) and group III (HbA1c ≥ 9.0%). RESULTS Patients in group I showed no significant HbA1c reduction with any insulin regimens (detemir, aspart, detemir and aspart or biphasic aspart 30 (Novo Nordisk A/S, DK-2880 Bagsvaerd, Denmark) after 24 weeks of treatment. In group II, although HbA1c was decreased for all insulin regimens, there was no difference in mean HbA1c reduction among the four insulin regimens. In patients with a high baseline HbA1c level (group III), mean HbA1c reduction was the greatest in patients on a basal-bolus regimen (detemir and aspart, -3.50%) and lowest in patients on a bolus regimen (aspart, -1.81%; p < 0.001). CONCLUSION For optimal glycaemic control, a basal-bolus regimen may be adequate for Korean patients with poorly controlled T2D (HbA1c ≥ 9.0%).
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Affiliation(s)
- Y-C Hwang
- Division of Endocrinology and Metabolism, Department of Medicine, Kyung Hee University School of Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Korea
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Park HY, Kang JG, Choi HH, Hwang SO, Kim WW, Jung JH, Lee YH, Yang JD, Lee SJ. Abstract P2-19-05: Oncoplastic breast conserving surgery with perforator flap in breast cancer patients. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p2-19-05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Purpose : Oncoplastic breast surgery has been used widely as a treatment protocol for breast cancer. Thoracodorsal artery perforator (TDAP) flap and intercostal artery perforator (ICAP) flap can provide adequate cover without sacrificing any muscle and allow closing of the donor sites in inconspicuous sites. Therefore, among the oncoplastic volume replacement techniques indicated using local flap that can adequately cover the volume of breast, TDAP and ICAP are especially suggested. This study describes the use of TDAP and ICAP flap techniques after breast conserving surgery. Methods : From March 2010 to August 2012, 38 patients with breast cancer received breast reconstruction. All patients who were selected had small- to moderate-sized defects on breasts, middle aged, and were not sensitive to scars. The TDAP flap is the first choice for performing the surgery, but if the perforator of the TDAP flap is not found, a dissection toward the anterior area to find an adequate perforator is made and the serratus anterior artery perforator is normally used. Otherwise after the dissection is performed more anterior, ICAP can be used. If the perforator penetrates the LD muscle, the TDAP flap can be used. The perforator that penetrates from the serratus anterior muscle is also used in the anterior area. Otherwise, ICAP can be used in partial breast reconstruction. The TDAP flap can be applied to any defect site regardless of the size of the defect area. Results : The mean age was 44.9 years and the average follow-up interval was 6 months. The average specimen weight was 98g. Complications developed in 4 cases including 3 cases of venous congestion, though self-limited, and 1 case of wound disruption on the inframammary fold suture area. Majority of the patients were satisfied with the cosmetic result.
Conclusion : Thoracodorsal artery perforator flap (TDAP) and intercostal artery perforator flap (ICAP) techniques can be reliable and useful in correcting breast deformity after breast conservation surgery, especially in patients with small- to moderate-sized defects on breasts.
Key Words : intercostal artery perforator flap, thoracodorsal artery perforator flap Oncoplastic surgery, ICAP, TDAP.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-19-05.
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Affiliation(s)
- HY Park
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - JG Kang
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - HH Choi
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - SO Hwang
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - WW Kim
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - JH Jung
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - YH Lee
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - JD Yang
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
| | - SJ Lee
- Kyungpook National University Medical Center, Daegu, Gyeongsangbuk-Do, Republic of Korea; Hyosung Hospital, Daegu, Gyeongsangbuk-Do, Republic of Korea
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Park H, Kang JG, Choi HH, Kim WW, Hwang SO, Jung JH, Lee YH, Kim S. Abstract P5-17-02: Efficiency of methylene blue nanoparticles (nanoMB) as local injectable agent for photodynamic therapy in breast cancer. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p5-17-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Photodynamic therapy (PDT), a non-invasive and alternative method for the treatment of cancer, is a light-activated treatment modality for breast cancer. Destruction of cancerous cells by PDT is achieved by a combination of photosensitizer and light of an appropriate wavelength for the photosensitizer.
Methylene blue (MB) is a blue dye clinically being used and is known to show efficient photosensitizing activity with a very high yield of singlet oxygen generation (65%), where singlet oxygen is the actual therapeutic agent for PDT. However MB shows low cell uptake efficiency by itself and thus a low PDT efficacy. In this regard, we developed a nanoformulation of MB (nanoMB) to improve cancer cell uptake efficiency while keeping the high efficiency of singlet oxygen generation. NanoMB is composed of ternary components that are physically assembled in an aqueous milieu.
In this study, we investigated the cellular uptake of nanoMB and cancer cell apoptosis induced by nanoMB PDT in MDA-MB-231 human breast cancer cells in vitro and in vivo.
In vitro, nanoMB was indeed avidly taken up by MDA-MB231 cells, unlike free MB showing negligible cellular uptake. NanoMB formulation preserved the photosensitization activity of MB under laser irradiation at 655 nm. Taken together, it was revealed from the in vitro microscopic observation that nanoMB can efficiently destroy live MDA-MB231 cells even under red lamp illumination. In the control group, cells were treated with free MB and did not show phototoxic influence under the same light.
In vivo phototoxicity evaluation, the locally injected nanoMB was internalized into cancer cells. Upon annexin V treatment after laser irradiation at 655 nm, apoptosis of cancer cells was clearly observed from the spot where nanoMB and laser were applied together. The PDT-induced cell apoptosis was visualized in a simple mouse model by using fluorescently labeled annexinV that has high affinity toward apoptotic cells.
Briefly, cancer cells were inoculated in muscle on opposite sides and nanoMB was applied to both the inoculation sites. After some time, only one side was laser-treated and fluorescent annexinV was injected to both. Only the dual-treated side (nanoMB + laser) showed retention of annexinV after 1 hour, indicating the occurrence of apoptosis by the PDT treatment.
Free MB and nanoMB were applied by subcutaneous injection around an early tumor tissue (not intratumoral injection). After 1 hour, free MB signals disappeared whereas nanoMB was retained at the tumor, implying that nanoMB penetrated into the tumor through the basement membrane.
Laser irradiation was done one hour after sample injection for both free MB and nanoMB. This treatment (sample + laser) was repeated seven times. According to the results, only nanoMB showed the tumor growth suppression effect, demonstrating the potential of nanoMB as a local injectable PDT agent.
In this study, nanoMB (MBOF) presented avid internalization into live cancer cells while keeping the high photosensitizing efficiency of MB. Consequently, highly efficient PDT of cancer cells was demonstrated in vitro and in vivo.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-17-02.
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Affiliation(s)
- H Park
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - JG Kang
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - HH Choi
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - WW Kim
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - SO Hwang
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - JH Jung
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - YH Lee
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
| | - S Kim
- School of Medicine, Kyungpook National University, Daegu, Korea; Hyosung Medical Center, Daegu, Korea; Center for Theragnosis, Korea Institute of Science and Technology, Seoul, Korea
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Kim SH, Kang JG, Kim CS, Ihm SH, Choi MG, Yoo HJ, Lee SJ. Akt inhibition enhances the cytotoxic effect of apigenin in combination with PLX4032 in anaplastic thyroid carcinoma cells harboring BRAFV600E. J Endocrinol Invest 2013; 36:1099-104. [PMID: 24084189 DOI: 10.3275/9099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aim of the present study was to evaluate the effect of apigenin in combination with BRAFV600E inhibitor PLX4032 on cell survival, and to investigate the influence of Akt inhibition on the combined effect of apigenin and PLX4032 in ATC cells harboring BRAFV600E. In 8505C and FRO cells harboring BRAFV600E, after treatment of apigenin and PLX4032, the cell viability decreased, and the percentage of dead cells increased in a time- and concentration-dependent manner, respectively. In apigenin- and PLX4032- treated cells, compared with apigenin alone-treated cells, the cell viability was lessened, and the percentage of dead cells was multiplied. In the addition of PLX4032 to apigenin, compared with the treatment of apigenin alone, the protein levels of cleaved PARP-1 and cleaved caspase-3 were elevated, and phospho-ERK protein levels were reduced, and the protein levels of total ERK, c-Myc, BRAF, phospho-Akt, phospho-p70S6K and phospho-4EBP1 were not varied. Compared with the treatment of PLX4032 alone, phosphop70S6K protein levels were reduced, and the other protein levels were not altered. Phospho-ERK protein levels were reduced only in 8505C cells. Under the co-treatment of apigenin and PLX4032, administration of the PI3K inhibitor wortmannin further decreased the cell viability, and increased the percentage of dead cells. In conclusion, our results suggest that PLX4032 augments apigenin-induced cytotoxicity in ATC cells harboring BRAFV600E. Moreover, Akt suppression potentiates the combined effect of apigenin and PLX4032 in ATC cells harboring BRAFV600E.
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Affiliation(s)
- S H Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon 200-704, Republic of Korea
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Kim SH, Kang JG, Kim CS, Ihm SH, Choi MG, Yoo HJ, Lee SJ. Inhibition of p21 and Akt potentiates SU6656-induced caspase-independent cell death in FRO anaplastic thyroid carcinoma cells. Horm Metab Res 2013; 45:408-14. [PMID: 23386415 DOI: 10.1055/s-0033-1333716] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
SU6656 is a small-molecule indolinone that selectively inhibits Src family kinase and induces death of cancer cells. The aim of the present study was to investigate the influence of SU6656 on cell survival and to assess the role of p21 and PI3K/Akt signaling in cell survival resulting from SU6656 treatment in anaplastic thyroid carcinoma (ATC) cells. When 8505C, CAL62, and FRO ATC cells were treated with SU6656, the viability of 8505C and CAL62 ATC cells decreased only after treatment with SU6656 at a dosage of 100 μM for 72 h, while the viability of FRO ATC cells decreased after treatment with SU6656 in a concentration- and time-dependent manner. Cell viability was not changed by pretreatment with the broad-spectrum caspase inhibitor z-VAD-fmk. Phospho-Src protein levels were reduced, and p21 protein levels were elevated. Phospho-ERK1/2 protein levels were multiplied without alteration of total ERK1/2, total Akt, and phospho-Akt protein levels. Regarding FRO ATC cells, the decrement of cell viability, the increment of cleaved PARP-1 protein levels, and the decrement of phospho-Src protein levels were shown in p21 siRNA- or LY294002-pretreated cells compared to SU6656-treated control cells. ERK1/2 siRNA transfection did not affect cell viability and protein levels of cleaved PARP-1, p21, and Akt. In conclusion, these results suggest that SU6656 induces caspase-independent death of FRO ATC cells by overcoming the resistance mechanism involving p21 and Akt. Suppression of p21 and Akt enhances the cytotoxic effect of SU6656 in FRO ATC cells.
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Affiliation(s)
- S H Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
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12
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Kim SH, Kang JG, Kim CS, Ihm SH, Choi MG, Yoo HJ, Lee SJ. CCAAT/Enhancer-binding protein-homologous protein sensitizes to SU5416 by modulating p21 and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma cells. Horm Metab Res 2013; 45:9-14. [PMID: 22918703 DOI: 10.1055/s-0032-1323680] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SU5416, vascular endothelial cell growth factor receptor inhibitor, suppresses hypoxia-induced angiogenesis, growth, proliferation, and metastasis in cancer cells. CCAAT/enhancer-binding protein-homologous protein (CHOP) has pivotal roles in regulation of growth and survival. In the present study, we evaluated the effects of SU5416 on cell survival, p21, and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma (ATC) cells. Moreover, we investigated the roles of CHOP in cell survival under condition of SU5416 treatment in FRO ATC cells. After SU5416 treatment, cell viability, PARP-1, and caspase-3 protein levels were not changed. p53 and p27 protein levels decreased while p21 protein levels increased. Phospho-Akt protein levels were not altered. In SU5416-treated situation, cell viability was not different before and after administration of either p21 siRNA or LY294002 whereas it was lessened after co-administration of p21 siRNA and LY294002. Compared to SU5416 treatment alone, cell viability was reduced with CHOP plasmid but it was unchanged with CHOP siRNA. PARP-1 and caspase-3 protein levels with CHOP plasmid were elevated whereas the protein levels with CHOP siRNA were similar. While CHOP plasmid transfection diminished p21 and phospho-Akt protein levels, CHOP siRNA transfection did not alter the protein levels. In conclusion, these results suggest that CHOP may sensitize FRO ATC cells to SU5416 thereby inhibiting cell survival by modulating p21 and PI3K/Akt signal pathway. Furthermore, these findings imply that CHOP may be a possible candidate as the chemosensitizing factor for induction of cytotoxicity in ATC cells exposed to SU5416.
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Affiliation(s)
- S H Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
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13
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Kang JG, Lee GH, Park KS, Kim SO, Lee S, Kim DW, Park JG. Three-dimensional hierarchical self-supported multi-walled carbon nanotubes/tin(iv) disulfide nanosheets heterostructure electrodes for high power Li ion batteries. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm16248b] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Ko YD, Kang JG, Lee GH, Park JG, Park KS, Jin YH, Kim DW. Sn-induced low-temperature growth of Ge nanowire electrodes with a large lithium storage capacity. Nanoscale 2011; 3:3371-3375. [PMID: 21750788 DOI: 10.1039/c1nr10471c] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We herein present the synthesis of germanium (Ge) nanowires on Au-catalyzed low-temperature substrates using a simple thermal Ge/Sn co-evaporation method. Incorporation of a low-melting point metal (Sn) enables the efficient delivery of Ge vapor to the substrate, even at a source temperature below 600 °C. The as-synthesized nanowires were found to be a core/shell heterostructure, exhibiting a uniform single crystalline Ge sheathed within a thin amorphous germanium suboxide (GeO(x)) layer. Furthermore, these high-density Ge nanowires grown directly on metal current collectors can offer good electrical connection and easy strain relaxation due to huge volume expansion during Li ion insertion/extraction. Therefore, the self-supported Ge nanowire electrodes provided excellent large capacity with little fading upon cycling (a capacity of ∼900 mA h g(-1) at 1C rate).
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Affiliation(s)
- Young-Dae Ko
- Nano-Photonics Research Center, Korea Institute of Science and Technology, Seoul, 136-791, Korea
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15
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Park KS, Choi YJ, Kang JG, Sung YM, Park JG. The effect of the concentration and oxidation state of Sn on the structural and electrical properties of indium tin oxide nanowires. Nanotechnology 2011; 22:285712. [PMID: 21659686 DOI: 10.1088/0957-4484/22/28/285712] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
High quality single-crystalline indium tin oxide (ITO) nanowires with controlled Sn contents of up to 32.5 at.% were successfully synthesized via a thermal metal co-evaporation method, based on a vapor-liquid-solid growth mode, at a substrate temperature of as low as 540 °C. The high solubility of Sn in the nanowires was explained with the existence of Sn(2+) ions along with Sn(4+) ions: the coexistence of Sn(2+) and Sn(4+) ions facilitated their high substitutional incorporation into the In(2)O(3) lattice by relaxing structural and electrical disturbances due to the differences in ionic radii and electrical charges between Sn and In(3+) ions. It was revealed that, while the lattice parameter of the ITO nanowires had a minimum value at a Sn content of 6.3 at.%, the electrical resistivity had a minimum value of about 10(-3) Ω cm at a Sn content of 14 at.%. These structural and electrical behaviors were explained by variation in the relative and total amounts of the two species, Sn(2+) and Sn(4+).
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Affiliation(s)
- Kyung-Soo Park
- Nano-Photonics Research Center, Korea Institute of Science and Technology, PO Box 131, Cheongryang, Seoul, 130-650, Korea
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Lee SJ, Kim SH, Kang JG, Kim CS, Ihm SH, Choi MG, Yoo HJ. Alpha-lipoic acid inhibits endoplasmic reticulum stress-induced cell death through PI3K/Akt signaling pathway in FRTL5 thyroid cells. Horm Metab Res 2011; 43:445-51. [PMID: 21590646 DOI: 10.1055/s-0031-1277182] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Alpha-lipoic acid (ALA) has been shown to modulate cell death via PI3K/Akt signal pathway in various cells. In the present study, the effects of ALA on cell death and PI3K/Akt signal pathway linked to cell death-related proteins during endoplasmic reticulum (ER) stress in FRTL5 thyroid cells were evaluated. In FRTL5 thyroid cells, cell viability increased by ALA pretreatment in tunicamycin (TN)-treated cells. When TN was treated, CCAAT/enhancer-binding protein-homologous protein (CHOP) and Bax protein levels were elevated while Bcl-2 protein levels were reduced. ALA diminished CHOP and Bax protein levels, and augmented Bcl-2 protein levels in TN-treated cells. After exposure to TN, phospho-Akt protein levels were repressed whereas total Akt protein levels were not changed. ALA increased phospho-Akt protein levels but not total Akt protein levels in both non-TN-treated and TN-treated cells. After LY294002 administration in non-TN-treated cells, cell viability was reduced, and CHOP and Bax protein levels were elevated, and Bcl-2 protein levels were reduced. The CHOP, Bcl-2 and Bax protein levels were not different after LY294002 administration in TN-treated cells. LY294002 and wortmannin decreased cell viability, and increased CHOP and Bax protein levels, and decreased Bcl-2 protein levels in ALA-pretreated and TN-treated cells. In conclusion, these results suggest that ER stress may induce cell death by modulating PI3K/Akt signal pathway linked to cell death-related proteins in FRTL5 thyroid cells. Moreover, these findings imply that ALA may ameliorate ER stress-induced cell death by activating PI3K/Akt signal pathway and attenuating changes of cell death-related proteins in FRTL5 thyroid cells.
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Affiliation(s)
- S J Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea.
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17
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Lee SJ, Kim SH, Kang JG, Kim CS, Ihm SH, Choi MG, Yoo HJ. Effects of all-trans retinoic acid on sodium/iodide symporter and CCAAT/enhancer-binding protein-homologous protein under condition of endoplasmic reticulum stress in FRTL5 thyroid cells. Horm Metab Res 2011; 43:331-6. [PMID: 21225541 DOI: 10.1055/s-0030-1269907] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In thyroid cells, the effects of all- TRANS retinoic acid (ATRA) on sodium/iodide symporter (NIS) and CCAAT/enhancer-binding protein-homologous protein (CHOP) under condition of endoplasmic reticulum (ER) stress have not been evaluated. In the present study, the relationships between NIS, CHOP, and p38 MAPK, and the effects of ATRA on NIS and CHOP expression as well as on p38 MAPK activation under condition of ER stress in thyroid cells were investigated. In FRTL5 thyroid cells, NIS mRNA and protein levels decreased following tunicamycin (TN) treatment, while CHOP mRNA and protein levels increased. In addition, while CHOP mRNA levels decreased after administration of tauro-UDCA and siCHOP, NIS mRNA levels were not altered. After pretreatment with SB203580, NIS mRNA levels decreased in non-TN-treated cells but increased in TN-treated cells. In contrast, CHOP mRNA levels decreased in both non-TN-treated and TN-treated cells. Exposure to ATRA decreased NIS mRNA levels in non-TN-treated cells but increased NIS mRNA levels in TN-treated cells. ATRA decreased CHOP mRNA levels in both non-TN-treated and TN-treated cells although the response was significant only in TN-treated cells. Phospho-p38 MAPK protein levels but not total p38 MAPK protein levels increased in TN-treated cells. ATRA attenuated this increase in phopho-p38 MAPK protein levels. In conclusion, our results demonstrate that ER stress may induce reciprocal changes in NIS and CHOP expression via p38 MAPK in FRTL5 thyroid cells, and that ATRA may attenuate ER stress-induced alterations in NIS and CHOP expression by modulating the phosphorylation of p38 MAPK in FRTL5 thyroid cells.
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Affiliation(s)
- S J Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea.
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18
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Lim SJ, Park KO, Kang JG, Lee JS, Eom JS. Acute Appendicitis Presenting with Escherichia coliBacteremia without Perforation in a Healthy Male. Infect Chemother 2011. [DOI: 10.3947/ic.2011.43.2.210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Seung Jin Lim
- Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea
| | - Kwon-Oh Park
- Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea
| | - Jin-Gu Kang
- Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea
| | - Jin-Seo Lee
- Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea
| | - Joong-Sik Eom
- Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea
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Kang JG, Park CY, Kang JH, Park YW, Park SW. Randomized controlled trial to investigate the effects of a newly developed formulation of phentermine diffuse-controlled release for obesity. Diabetes Obes Metab 2010; 12:876-82. [PMID: 20920040 DOI: 10.1111/j.1463-1326.2010.01242.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AIM To evaluate the efficacy and safety of a newly developed formulation of phentermine diffuse-controlled release (DCR) in patients with obesity. METHODS This was a randomized, double-blind, placebo-controlled trial of 12 weeks of treatment with phentermine DCR 30 mg (n = 37) or placebo (n = 37), administered once daily in patients with obesity with controlled diabetes, hypertension or dyslipidaemia. The efficacy was evaluated by changes in body weight and waist circumference from baseline at 12 weeks and also changes in metabolic parameters, including lipid profiles and blood pressure. RESULTS The participants in the phentermine DCR group showed significant reductions in body weight (-8.1 ± 3.9 vs. -1.7 ± 2.9 kg, p < 0.001) and waist circumference (7.2 ± 0.5 vs. 2.1 ± 0.6 cm, p < 0.001) compared with those in the placebo group. Weight reductions of 5% or greater from the baseline (95.8 vs. 20.8%, p < 0.001) and 10% or more (62.5 vs. 4.7%, p < 0.001) were achieved in the DCR phentermine group and placebo group, respectively. Total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels were significantly improved in the phentermine DCR group. However, there were no significant differences in systolic and diastolic blood pressure between the groups. Dry mouth and insomnia were the most common adverse events, but these were mild to moderate and transient. CONCLUSIONS Short-term phentermine DCR treatment resulted in significant reduction in weight and improvement of metabolic parameters, including waist circumference and some lipid profiles, without clinically severe adverse events. Further study is needed to show long-term efficacy and safety of phentermine DCR in Korean patients with obesity.
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Affiliation(s)
- J G Kang
- Department of Endocrinology and Metabolism, Hallym University School of Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
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20
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Choi SJ, Ahn HJ, Yang MK, Kim CS, Sim WS, Kim JA, Kang JG, Kim JK, Kang JY. Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters. Acta Anaesthesiol Scand 2010; 54:212-7. [PMID: 19719816 DOI: 10.1111/j.1399-6576.2009.02101.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time. METHODS Thirty-three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre-oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time. RESULTS The desaturation response time of SpO(2) to 95% after apnea was 82.0 s (interquartile range: 67.0-98.5 s) vs. 94.0 s (interquartile range: 84.0-106.5 s) (P<0.001) and SpO(2) to 90% was 94.0 s (interquartile range: 75.5-109.5 s) vs. 100.0 s (interquartile range: 84.5-114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO(2) was 23.2+/-5.6 vs. 28.9+/-7.6 s (P<0.001) in the reflectance and transmission oximeters, respectively. CONCLUSION In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter.
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Affiliation(s)
- S J Choi
- Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-Ku, Seoul, Korea
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21
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Abstract
We propose a promising synthetic technique, which we term 'self-supported nanostructuring', for the direct growth of one-dimensional, SnO2 nanowires on the current collector. The technique is based on a vapor-liquid-solid (VLS) mechanism via thermal evaporation at low synthetic temperature (600 degrees C). The as-synthesized SnO2 nanowire electrode did not have any buffer layer prior to the nanowire evolution, and exhibited a single crystalline phase with highly uniform morphology and a thin diameter ranging from 40 to 50 nm with a length of more than 1 microm. The SnO2 nanowire electrode demonstrated stable cycling behaviors and delivered a high specific discharge capacity of 510 mA h g(-1), even at the 50th cycle, which exceeded that of SnO2 nanopowder and Sn nanopowder electrodes. Furthermore, the SnO2 nanowire electrode displayed superior rate capabilities with a rechargeable discharge capacity of 600 mA h g(-1) at 3 C (where 1 C = 782 mA g(-1)), 530 mA h g(-1) at 5 C, and 440 mA h g(-1) at 10 C. Our results support the potential opportunity for developing high-performance Li-ion batteries based on Li-alloying anode materials in terms of high-power density and high-energy density.
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Affiliation(s)
- Young-Dae Ko
- Nano-Materials Research Center, Nano-Science Research Division, Korea Institute of Science and Technology, Seoul 136-791, Korea
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22
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Ko YD, Kang JG, Choi KJ, Park JG, Ahn JP, Chung KY, Nam KW, Yoon WS, Kim DW. High rate capabilities induced by multi-phasic nanodomains in iron-substituted calcium cobaltite electrodes. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b817120c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Hong YF, Kang JG, Lee HY, Uhm HS, Moon E, Park YH. Sterilization effect of atmospheric plasma on Escherichia coli and Bacillus subtilis endospores. Lett Appl Microbiol 2008; 48:33-7. [PMID: 19018968 DOI: 10.1111/j.1472-765x.2008.02480.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS Escherichia coli and Bacillus subtilis spores were treated with an atmospheric plasma mixture created by the ionization of helium and oxygen to investigate the inactivation efficiency of a low-temperature plasma below 70 degrees C. METHODS AND RESULTS An electrical discharge plasma was produced at a radio frequency (RF) of 13.56 MHz, connected to a perforated circular electrode with a discharge spacing of 1-15 mm. The discharge gas was helium with 0-2% oxygen. For the plasma treatment, a dried E. coli cell or B. subtilis endospore suspension on a cover-glass was exposed to oxygen downstream of the plasma from holes in an RF-powered electrode. The sterilization effect of the RF plasma was highest with 0.2% oxygen, corresponding to the maximum production of oxygen radicals. CONCLUSIONS Oxygen radicals generated by RF plasma are effective for the destruction of bacterial cells and endospores. SIGNIFICANCE AND IMPACT OF THE STUDY Low-temperature atmospheric plasma can be used for the disinfection of diverse objects, especially for the inactivation of bacterial endospores.
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Affiliation(s)
- Y F Hong
- Department of Molecular Science and Technology, Ajou University, Youngtong-Gu, Suwon, Korea
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Kang JG, Ko YD, Park JG, Kim DW. Origin of Capacity Fading in Nano-Sized Co 3O 4Electrodes: Electrochemical Impedance Spectroscopy Study. Nanoscale Res Lett 2008; 3:390. [PMCID: PMC3244898 DOI: 10.1007/s11671-008-9176-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Accepted: 09/11/2008] [Indexed: 05/25/2023]
Abstract
Transition metal oxides have been suggested as innovative, high-energy electrode materials for lithium-ion batteries because their electrochemical conversion reactions can transfer two to six electrons. However, nano-sized transition metal oxides, especially Co3O4, exhibit drastic capacity decay during discharge/charge cycling, which hinders their practical use in lithium-ion batteries. Herein, we prepared nano-sized Co3O4with high crystallinity using a simple citrate-gel method and used electrochemical impedance spectroscopy method to examine the origin for the drastic capacity fading observed in the nano-sized Co3O4anode system. During cycling, AC impedance responses were collected at the first discharged state and at every subsequent tenth discharged state until the 100th cycle. By examining the separable relaxation time of each electrochemical reaction and the goodness-of-fit results, a direct relation between the charge transfer process and cycling performance was clearly observed.
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Affiliation(s)
- Jin-Gu Kang
- Nano-materials Research Center, Nano-science Research Division, Korea Institute of Science and Technology, Seoul, 136-791, South Korea
| | - Young-Dae Ko
- Nano-materials Research Center, Nano-science Research Division, Korea Institute of Science and Technology, Seoul, 136-791, South Korea
| | - Jae-Gwan Park
- Nano-materials Research Center, Nano-science Research Division, Korea Institute of Science and Technology, Seoul, 136-791, South Korea
| | - Dong-Wan Kim
- Nano-materials Research Center, Nano-science Research Division, Korea Institute of Science and Technology, Seoul, 136-791, South Korea
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25
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Hong SM, Lee DW, Kang JG, Kim HS, Cho SH. Human Activated Lymphocyte Treated with Anti-CD3, CD16, CD56 Monoclonal Antibody and IL-2. Immune Netw 2005. [DOI: 10.4110/in.2005.5.1.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
| | | | - Jin-Gu Kang
- Department of Medicine, Yonsei University College of Medicine, Korea
| | - Han-Soo Kim
- Department of Medicine, Yonsei University College of Medicine, Korea
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26
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Hamiche A, Kang JG, Dennis C, Xiao H, Wu C. Histone tails modulate nucleosome mobility and regulate ATP-dependent nucleosome sliding by NURF. Proc Natl Acad Sci U S A 2001; 98:14316-21. [PMID: 11724935 PMCID: PMC64679 DOI: 10.1073/pnas.251421398] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nucleosome Remodeling Factor (NURF) is an ATP-dependent nucleosome remodeling complex that alters chromatin structure by catalyzing nucleosome sliding, thereby exposing DNA sequences previously associated with nucleosomes. We systematically studied how the unstructured N-terminal residues of core histones (the N-terminal histone tails) influence nucleosome sliding. We used bacterially expressed Drosophila histones to reconstitute hybrid nucleosomes lacking one or more histone N-terminal tails. Unexpectedly, we found that removal of the N-terminal tail of histone H2B promoted uncatalyzed nucleosome sliding during native gel electrophoresis. Uncatalyzed nucleosome mobility was enhanced by additional removal of other histone tails but was not affected by hyperacetylation of core histones by p300. In addition, we found that the N-terminal tail of the histone H4 is specifically required for ATP-dependent catalysis of nucleosome sliding by NURF. Alanine scanning mutagenesis demonstrated that H4 residues 16-KRHR-19 are critical for the induction of nucleosome mobility, revealing a histone tail motif that regulates NURF activity. An exchange of histone tails between H4 and H3 impaired NURF-induced sliding of the mutant nucleosome, indicating that the location of the KRHR motif in relation to global nucleosome structure is functionally important. Our results provide functions for the N-terminal histone tails in regulating the mobility of nucleosomes.
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Affiliation(s)
- A Hamiche
- Laboratory of Molecular Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
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27
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van Iersel MW, Oetting RD, Hall DB, Kang JG. Application technique and irrigation method affect imidacloprid control of silverleaf whiteflies (Homoptera: Aleyrodidae) on poinsettias. J Econ Entomol 2001; 94:666-672. [PMID: 11425021 DOI: 10.1603/0022-0493-94.3.666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Subirrigation systems are increasingly used to water and fertilize greenhouse crops. They also appear to be well suited for the application of systemic pesticides. We conducted two studies to look at interactive effects ofimidacloprid application technique and irrigation method on plant uptake of imidacloprid and whitefly control. Drench applications of imidacloprid resulted in much higher concentrations in the leaves than applications to the bottom of pots after 14 d. However, imidacloprid efficacy in subirrigated plants was better if the imidacloprid was applied to the bottom of the pot than when an equal amount was applied as a drench. In drip-irrigated plants, imidacloprid efficacy was greater after a drench than after an application to the bottom of the pots. A second study showed that drench applications to drip-irrigated plants result in high imidacloprid concentrations in the bottom of the canopy, whereas bottom applications to subirrigated plants result in a more even distribution of imidacloprid throughout the plant. Surprisingly, the high leaf imidacloprid concentrations in the bottom layer of drip-irrigated plants did not result in improved whitefly control. Imidacloprid efficacy was better in subirrigated, bottom-treated plants than in drip-irrigated, drenched plants. Overall, results from these studies indicate that imidacloprid is very effective when applied to the bottom of subirrigated pots.
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Affiliation(s)
- M W van Iersel
- Department of Horticulture, the University of Georgia, Griffin 30223, USA
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Kang JG, Yun J, Kim DH, Chung KS, Fujioka S, Kim JI, Dae HW, Yoshida S, Takatsuto S, Song PS, Park CM. Light and brassinosteroid signals are integrated via a dark-induced small G protein in etiolated seedling growth. Cell 2001; 105:625-36. [PMID: 11389832 DOI: 10.1016/s0092-8674(01)00370-1] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Plant growth and development are regulated through coordinated interactions between light and phytohormones. Here, we demonstrate that a dark-induced small G protein, pea Pra2, regulates a variant cytochrome P450 that catalyzes C-2 hydroxylation in brassinosteroid biosynthesis. The cytochrome P450 is dark-induced and predominantly expressed in the rapidly elongating zone of etiolated pea epicotyls, where Pra2 is also most abundant. Transgenic plants with reduced Pra2 exhibit a dark-specific dwarfism, which is completely rescued by exogenous brassinolide. Overexpression of the cytochrome P450 results in enhanced hypocotyl growth even in the light, which phenocopies the etiolated hypocotyls. We therefore propose that Pra2 and its orthologs are molecular mediators for the cross-talk between light and brassinosteroids in the etiolation process in plants.
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Affiliation(s)
- J G Kang
- Kumho Life and Environmental Science Laboratory, 1 Oryong-dong, Buk-gu, Kwangju 500-712, South Korea
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Park JM, Gim BS, Kim JM, Yoon JH, Kim HS, Kang JG, Kim YJ. Drosophila Mediator complex is broadly utilized by diverse gene-specific transcription factors at different types of core promoters. Mol Cell Biol 2001; 21:2312-23. [PMID: 11259581 PMCID: PMC86865 DOI: 10.1128/mcb.21.7.2312-2323.2001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To decipher the mechanistic roles of Mediator proteins in regulating developmental specific gene expression and compare them to those of TATA-binding protein (TBP)-associated factors (TAFs), we isolated and analyzed a multiprotein complex containing Drosophila Mediator (dMediator) homologs. dMediator interacts with several sequence-specific transcription factors and basal transcription machinery and is critical for activated transcription in response to diverse transcriptional activators. The requirement for dMediator did not depend on a specific core promoter organization. By contrast, TAFs are preferentially utilized by promoters having a specific core element organization. Therefore, Mediator proteins are suggested to act as a pivotal coactivator that integrates promoter-specific activation signals to the basal transcription machinery.
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Affiliation(s)
- J M Park
- National Creative Research Initiative Center for Genome Regulation, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea
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Kang JG, Cusso F, Belliveau TF, Simkin DJ. Emission spectra and decay kinetics of the A-band emission from Pb2+centres in KCl and KI single crystals. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/18/24/019] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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31
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Im YJ, Park CM, Kim JI, Yang SS, Kang JG, Rho SH, Kim JI, Song WK, Song PS, Eom SH. Crystallization and preliminary X-ray crystallographic studies of response regulator for cyanobacterial phytochrome, Rcp1. Acta Crystallogr D Biol Crystallogr 2000; 56:1446-8. [PMID: 11053847 DOI: 10.1107/s0907444900009951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2000] [Accepted: 07/17/2000] [Indexed: 11/10/2022]
Abstract
The key response-regulator gene of light regulation, rcp1, from Synechocystis sp. has been overexpressed, purified and subsequently crystallized using ammonium sulfate as a precipitant in forms suitable for X-ray crystallographic studies. A native data set was collected to a resolution of 2.5 A at cryogenic temperature. The crystals belong to the hexagonal space group P6(3), with unit-cell parameters a = b = 89.04 (5), c = 60.29 (3) A. The Matthews parameter suggests that Rcp1 crystallizes with two molecules per asymmetric unit.
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Affiliation(s)
- Y J Im
- Department of Life Science, Kwangju Institute of Science and Technology, Kwangju 500-712, South Korea
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32
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Park CM, Kim JI, Yang SS, Kang JG, Kang JH, Shim JY, Chung YH, Park YM, Song PS. A second photochromic bacteriophytochrome from Synechocystis sp. PCC 6803: spectral analysis and down-regulation by light. Biochemistry 2000; 39:10840-7. [PMID: 10978170 DOI: 10.1021/bi992831r] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It now appears that photosynthetic prokaryotes and lower eukaryotes possess higher plant phytochrome-like proteins. In this work, a second phytochrome-like gene was isolated, in addition to the recently identified Cph1 phytochrome, from the Synechocystis sp. PCC 6803, and its gene product was characterized photochemically. The open reading frame sll0821 (designated cph2 in this work) has structural characteristics similar to those of the plant phytochromes and the Synechocystis Cph1 with high amino acid sequence homology in the N-terminal chromophore binding domain. The predicted Cph2 protein consists of 1276 amino acids with a calculated molecular mass of 145 kDa. Interestingly, the Cph2 protein has two putative chromophore binding domains, one around Cys-129 and the other around Cys-1022. The Cph2 was overexpressed in E. coli as an Intein/CBD (chitin binding domain) fusion and in vitro reconstituted with phycocyanobilin (PCB) or phytochromobilin (PPhiB). Both the Cph2-PCB and Cph2-PPhiB adducts showed the typical photochromic reversibility with the difference spectral maxima at 643/690 and 655/701 nm, respectively. The Cys-129 was confirmed to be the chromophore binding residue by in vitro mutagenesis and Zn(2+) fluorescence. The microenvironment of the chromophore in Cph2 seems to be similar to that in plant phytochromes. The cph2 gene expression was dark-induced and down-regulated to a basal level by light, like the cph1 gene. These observations suggest that Synechocystis species have multiple photosensory proteins, probably with distinct roles, as in higher plants.
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Affiliation(s)
- C M Park
- Kumho Life & Environmental Science Laboratory, 1 Oryong-Dong, Buk-Ku, Kwangju 500-712, Korea
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Park CM, Shim JY, Yang SS, Kang JG, Kim JI, Luka Z, Song PS. Chromophore-apoprotein interactions in Synechocystis sp. PCC6803 phytochrome Cph1. Biochemistry 2000; 39:6349-56. [PMID: 10828948 DOI: 10.1021/bi992916s] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The secondary, tertiary, and quaternary structures of the Synechocystis Cph1 phytochrome were investigated by absorption and circular dichroism spectroscopy, size exclusion chromatography, and limited proteolysis. The Cph1 protein was coexpressed with a bacterial thioredoxin in Escherichia coli, reconstituted in vitro with tetrapyrrole chromophores, and purified by chitin affinity chromatography. The resultant Cph1 holoproteins were essentially pure and had the specific absorbance ratio (SAR) of 0.8-0.9. Circular dichroism spectroscopy and limited proteolysis showed that the chromophore binding induced marked conformational changes in the Cph1 protein. The alpha-helical content increased to 42-44% in the holoproteins from 37% in the apoprotein. However, no significant difference in the secondary structure was detected between the Pr and Pfr forms. The tertiary structure of the Cph1 apoprotein appeared to be relatively flexible but became more compact and resistant to tryptic digestion upon chromophore binding. Interestingly, a small chromopeptide of about 30 kDa was still predominant even after longer tryptic digestion. The N-terminal location of this chromopeptide was confirmed by expression in E. coli and in vitro reconstitution with chromophores of the 32.5 kDa N-terminal fragment of the Cph1 protein. This chromopeptide was fully photoreversible with the spectral characteristic similar to that of the full-size Cph1 protein. The Cph1 protein forms dimers through the C-terminal region. These results suggest that the prokaryotic Cph1 phytochrome shares the structural and conformational characteristics of plant phytochromes, such as the two-domain structure consisting of the relatively compact N-terminal and the relatively flexible C-terminal regions, in addition to the chromophore-induced conformational changes.
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Affiliation(s)
- C M Park
- Kumho Life & Environmental Science Laboratory, Kwangju 500-712, Korea
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Abstract
An antifungal bacterial strain, isolated from a greenhouse soil sample, inhibits growth of microflora nearby. It was selected for further studies of bacterial antifungal properties. This isolate was identified as a Pseudomonas sp. based on carbohydrate utilization, and other biochemical and physiological tests. Petri plate assay revealed that the Pseudomonas sp. exhibited antifungal activity against the plant pathogens, Pythium ultimum, Rhizoctonia solani, Phytophthora capsici, Botrytis cinerea and Fusarium oxysporum. Using direct inhibition bioassay on TLC plates after ethyl acetate extraction of the culture filtrate, we correlated antifungal activity with production of antifungal compounds. An antifungal antibiotic was isolated from the culture filtrate and was identified as N-butylbenzenesulphonamide. ED50, values of the N-butylbenzenesulphonamide against P. ultimum, P. capsici, R. solani, and B. cinerea were 73, 41, 33 and 102 ppm, respectively.
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Affiliation(s)
- K K Kim
- Department of Agricultural Chemistry, Institute for Agricultural Resource Utilization, Gyeongsang National University, Chinju, Korea
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Abstract
SigR (sigma(R)) is a sigma factor responsible for inducing the thioredoxin system in response to oxidative stress in the antibiotic-producing, Gram-positive bacterium Streptomyces coelicolor A3(2). Here we identify a redox-sensitive, sigma(R)-specific anti-sigma factor, RsrA, which binds sigma(R) and inhibits sigma(R)-directed transcription in vitro only under reducing conditions. Exposure to H(2)O(2) or to the thiol-specific oxidant diamide caused the dissociation of the sigma(R)-RsrA complex, thereby allowing sigma(R)-dependent transcription. This correlated with intramolecular disulfide bond formation in RsrA. Thioredoxin was able to reduce oxidized RsrA, suggesting that sigma(R), RsrA and the thioredoxin system comprise a novel feedback homeostasis loop that senses and responds to changes in the intracellular thiol-disulfide redox balance.
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Affiliation(s)
- J G Kang
- Department of Microbiology, College of Natural Sciences, and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, Korea
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Paget MS, Kang JG, Roe JH, Buttner MJ. sigmaR, an RNA polymerase sigma factor that modulates expression of the thioredoxin system in response to oxidative stress in Streptomyces coelicolor A3(2). EMBO J 1998; 17:5776-82. [PMID: 9755177 PMCID: PMC1170905 DOI: 10.1093/emboj/17.19.5776] [Citation(s) in RCA: 169] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have identified an RNA polymerase sigma factor, sigmaR, that is part of a system that senses and responds to thiol oxidation in the Gram-positive, antibiotic-producing bacterium Streptomyces coelicolor A3(2). Deletion of the gene (sigR) encoding sigmaR caused sensitivity to the thiol-specific oxidant diamide and to the redox cycling compounds menadione and plumbagin. This correlated with reduced levels of disulfide reductase activity and an inability to induce this activity on exposure to diamide. The trxBA operon, encoding thioredoxin reductase and thioredoxin, was found to be under the direct control of sigmaR. trxBA is transcribed from two promoters, trxBp1 and trxBp2, separated by 5-6 bp. trxBp1 is transiently induced at least 50-fold in response to diamide treatment in a sigR-dependent manner. Purified sigmaR directed transcription from trxBp1 in vitro, indicating that trxBp1 is a target for sigmaR. Transcription of sigR itself initiates at two promoters, sigRp1 and sigRp2, which are separated by 173 bp. The sigRp2 transcript was undetectable in a sigR-null mutant, and purified sigmaR could direct transcription from sigRp2 in vitro, indicating that sigR is positively autoregulated. Transcription from sigRp2 was also transiently induced (70-fold) following treatment with diamide. We propose a model in which sigmaR induces expression of the thioredoxin system in response to cytoplasmic disulfide bond formation. Upon reestablishment of normal thiol levels, sigmaR activity is switched off, resulting in down-regulation of trxBA and sigR. We present evidence that the sigmaR system also functions in the actinomycete pathogen Mycobacterium tuberculosis.
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Affiliation(s)
- M S Paget
- John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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Kang JG, Hahn MY, Ishihama A, Roe JH. Identification of sigma factors for growth phase-related promoter selectivity of RNA polymerases from Streptomyces coelicolor A3(2). Nucleic Acids Res 1997; 25:2566-73. [PMID: 9185565 PMCID: PMC146787 DOI: 10.1093/nar/25.13.2566] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We examined the promoter selectivity of RNA polymerase (RNAP) from Streptomyces coelicolor at two growth phases by in vitro transcription. Distinct sets of promoters were preferentially recognized by either exponential or stationary phase RNAP. No change in molecular weight or net charge of the core subunits was observed, suggesting that the associated specificity factors determined phase-specific promoter selectivity of the holoenzyme. Five different specificity factors and their cognate promoters were identified by in vitro holoenzyme reconstitution and transcription assays. sigma66 (sigma hrdB) and sigma46 (sigma hrdD) recognized promoters (rrnD p2 and dagA p4 for sigma66, actII-orf4 p and whiB p2 for sigma46) preferentially transcribed by the exponential phase RNAP. sigma52 recognized promoters (dagA p3 and actIII px1) preferentially transcribed by the stationary phase RNAP. Sigma28 (sigma sigE) recognized promoters (hrdD p1, whiB p1 and dagA p2) transcribed equally by both RNAPs. A novel 31 kDa specificity factor recognized actIII px2, glnR p2 and hrdD p2 promoters preferentially transcribed by the stationary phase RNAP. This factor was isolated from the stationary phase RNAP and reconstituted holoenzyme in vitro as a sigma factor. The N-terminal sequence suggests that it is a novel factor. By examining phase-specific promoter recognition pattern we can predict that holoenzyme Esigma52 and Esigma31 activities are higher in the stationary phase, whereas Esigma66 and Esigma46activities are higher in the exponential phase. Possible promoter sequences recognized by some of these sigma factors were suggested.
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Affiliation(s)
- J G Kang
- Department of Microbiology, College of Natural Sciences, and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, Korea
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38
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Abstract
The rpoA gene, encoding the alpha subunit of RNA polymerase, was cloned from Streptomyces coelicolor A3(2). It is preceded by rpsK and followed by rplQ, encoding ribosomal proteins S11 and L17, respectively, similar to the gene order in Bacillus subtilis. The rpoA gene specifies a protein of 339 amino acids with deduced molecular mass of 36,510 Da, exhibiting 64.3 and 70.7% similarity over its entire length to Escherichia coli and B. subtilis alpha subunits, respectively. Using T7 expression system, we overexpressed the S. coelicolor alpha protein in E. coli. A small fraction of this protein was found to be assembled into E. coli RNA polymerase. Antibody against S. coelicolor alpha protein crossreacted with that of B. subtilis more than with the E. coli alpha subunit. The ability of recombinant alpha protein to assemble beta and beta' subunits into core enzyme in vitro was examined by measuring the core enzyme activity. Maximal reconstitution was obtained at alpha2:beta+beta' ratio of 1:2.3, indicating that the recombinant alpha protein is fully functional for subunit assembly. Similar results were also obtained for natural alpha protein. Limited proteolysis with endoproteinase Glu-C revealed that S. coelicolor alpha contains a tightly folded N-terminal domain and the C-terminal region is more protease-sensitive than that of E. coli alpha.
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Affiliation(s)
- E J Cho
- Department of Microbiology, College of Natural Sciences, Seoul National University, Korea
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Geis WP, Kim HC, McAfee PC, Kang JG, Brennan EJ. Synergistic benefits of combined technologies in complex, minimally invasive surgical procedures. Clinical experience and educational processes. Surg Endosc 1996; 10:1025-8. [PMID: 8864101 DOI: 10.1007/s004649900230] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The new burden surgical technology must assume demands not only improved efficiency and reduced risk, but also diminished cost and resource utilization. To this end, we have instituted the use of multiple, sequential technologies in complex, minimally invasive procedures: laparoscopic gastric surgery (44 cases), spine procedures (38 cases), and colectomies (96 cases). The technologies include head-mounted display, 3-D optics, robotic arm, harmonic scalpel, and optical access trocars. The combined use of these technologies shortened operative times, diminished use of personnel, and as associated with no technical mishap. Surgeon concentration and control of the operative environment were increased. In an effort to promote combined use of technologies, a structured teaching process was designed and implemented. It required five (average) experiences for efficient, hands-on implementation of combined technologies. We conclude that combined use of sophisticated technologies is safe and efficient; is accomplished by structured, moderately intense educational experience; and diminishes cost and use of human resources.
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Affiliation(s)
- W P Geis
- Minimally Invasive Surgical Training Institute (MISTI), St. Joseph Medical Center, 7620 York Road, Baltimore, MD 21204, USA
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Abstract
It has been suggested that glucose metabolites and insulin are the most important factors inducing ATP-citrate lyase (ACL) by a high carbohydrate diet. We have used a primary culture of rat hepatocytes to confirm the role of glucose and insulin in terms of ACL gene expression. The results showed that glucose displayed a direct effect on ACL gene expression and the insulin helps the glucose effect. The nucleotide sequences from -512 to -485 of the ACL promoter are highly homologous (70%) to the sequences surrounding the carbohydrate response element (ChoRE) of the S14 gene. The gel retardation analysis using ChoRE of the S14 gene showed that the ACL promoter which contains the ChoRE-like sequence specifically inhibited the formation of the complex by the nuclear proteins isolated from rat liver. To localize the regions which are involved in the regulation of ACL gene expression, transient expression assay using ACL promoter-CAT (chloramphenicol acetyltransferase) constructs containing various lengths of a 5' flanking region of the ACL gene were carried out. The proximal promoter region -419 to -1 containing several potential Sp1 binding sites showed the strong enhancing effect, which increases the transcription of CAT genes in the various cell lines, such as the CHO (Chinese hamster ovary) cell, the HepG2 cell, and primary cultured rat hepatocytes. In response to glucose, among the ACL promoter-CAT constructs, only pNP33-CAT (-1342 to -1) showed a 2.64 fold increase in CAT activity by a high concentration of glucose. The activation of ACL gene expression by glucose seems to be regulated in a complicated manner involving interactions between the contexts of the several sequence elements and various transacting factors, which is not a simple mechanism directed only by a short sequence element.
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Affiliation(s)
- K S Kim
- Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, Seoul, Korea
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Kin HS, Kang JG, Oh KW. Inhibition by ginseng total saponin of the development of morphine reverse tolerance and dopamine receptor supersensitivity in mice. Gen Pharmacol 1995; 26:1071-6. [PMID: 7557253 DOI: 10.1016/0306-3623(94)00267-q] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
1. Ginseng total saponin (GTS), 200 mg/kg i.p. 3 hr prior to morphine, inhibited the development of reverse tolerance to the ambulatory-accelerating effect of morphine. 2. GTS, 200 mg/kg, also prevented the development of dopamine receptor supersensitivity induced by the chronic administration of morphine, 10 mg/kg a day for 7 days. 3. These results suggest that GTS may be useful for the prevention and therapy of the adverse action of morphine.
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Affiliation(s)
- H S Kin
- Department of Pharmacology, College of Pharmacy, Chungbuk National University, Cheongju, Korea
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Kim HS, Kang JG, Rheu HM, Cho DH, Oh KW. Blockade by ginseng total saponin of the development of methamphetamine reverse tolerance and dopamine receptor supersensitivity in mice. Planta Med 1995; 61:22-25. [PMID: 7700985 DOI: 10.1055/s-2006-957991] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Repeated administration of methamphetamine (2 mg/kg) developed reverse tolerance to the ambulation-accelerating effect. Intraperitoneal administration of ginseng total saponin (GTS, 200 mg/kg of body weight) prior to and during chronic administration of methamphetamine inhibited the development of reverse tolerance. Dopamine receptor supersensitivity was also developed in reverse tolerant mice which had received the same methamphetamine. The development of dopamine receptor supersensitivity was evidenced by the enhanced hypothermic response to apomorphine (1 mg/kg) and the enhanced ambulatory activity of apomorphine (4 mg/kg). GTS also prevented the development of dopamine receptor supersensitivity induced by the chronic administration of methamphetamine. These results show that GTS may be useful for the prevention of and therapy for the adverse action of methamphetamine. It is concluded that the development of reverse tolerance to methamphetamine may be associated with the enhanced dopamine receptor supersensitivity since both phenomena were blocked by GTS.
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Affiliation(s)
- H S Kim
- Department of Pharmacology, College of Pharmacy, Chungbuk National University, Cheongju, Korea
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Kim HS, Kang JG, Seong YH, Nam KY, Oh KW. Blockade by ginseng total saponin of the development of cocaine induced reverse tolerance and dopamine receptor supersensitivity in mice. Pharmacol Biochem Behav 1995; 50:23-7. [PMID: 7700950 DOI: 10.1016/0091-3057(94)00224-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Daily repeated administration of cocaine (15 mg/kg, over a 7-day period) developed reverse tolerance to the ambulation-accelerating effect of cocaine. Intraperitoneal administration of ginseng total saponin (GTS, 100 and 200 mg/kg of body weight) prior to and during chronic administration of cocaine inhibited the development of reverse tolerance. Dopamine receptor supersensitivity was also developed in reverse tolerant mice that had received the same cocaine. The development of dopamine receptor supersensitivity was evidenced by the enhanced hypothermic response to apomorphine (1 mg/kg) and the enhanced ambulatory activity of apomorphine (4 mg/kg). GTS also prevented the development of dopamine receptor supersensitivity induced by the chronic administration of cocaine. These results provide that GTS may be useful for the prevention and therapy of the adverse action of cocaine. It is concluded that the development of reverse tolerance to the ambulation-accelerating effect of cocaine may be associated with the enhanced dopamine receptor sensitivity because both phenomena were blocked by GTS.
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Affiliation(s)
- H S Kim
- Department of Pharmacology, College of Pharmacy, Chungbuk National University, Cheongju, Korea
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Chinitz LA, Kronzon I, Trehan N, Kang JG. Total occlusion of the abdominal aorta in a patient with Takayasu's arteritis: the importance of lower rib notching in the differential diagnosis. Cathet Cardiovasc Diagn 1986; 12:405-8. [PMID: 2880669 DOI: 10.1002/ccd.1810120610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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