60 results on '"Kang GY"'
Search Results
2. Survey on awareness and perceptions of bisphosphonate-related osteonecrosis of the jaw in dental hygienists in Seoul
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Kim Sj, Mah Yj, and Kang Gy
- Subjects
Adult ,Dental Service, Hospital ,Education, Continuing ,Inservice Training ,Time Factors ,Attitude of Health Personnel ,Interprofessional Relations ,medicine.medical_treatment ,Dentistry ,Hospitals, General ,Hospitals, Special ,stomatognathic system ,Republic of Korea ,medicine ,Humans ,Dentistry (miscellaneous) ,In patient ,Hospitals, Teaching ,Medical History Taking ,Workplace ,Informed Consent ,business.industry ,Dental Clinics ,Professional Practice ,Bisphosphonate ,University hospital ,medicine.disease ,Work experience ,stomatognathic diseases ,Dental clinic ,Bisphosphonate-Associated Osteonecrosis of the Jaw ,Dental Hygienists ,business ,Osteonecrosis of the jaw - Abstract
We investigated awareness in dental hygienists of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in patients with osteoporosis and cancer and assessed the situation in systemic history investigations to broaden the scope of the dental hygienists' BRONJ awareness as a basis for contributing to preventing this disease. The study was carried out through a survey; 217 dental hygienists responded to the survey. They worked at 12 university and general hospitals, 10 dental hospitals and 35 dental clinics, for a total of 57 institutions in Seoul. The survey consisted of 37 questions: general characteristics (J Oral Maxillofac Surg 65: 2007; 369), systemic history investigations (Ruggiero et al. J Oral Maxillofac Surg 62: 2004; 527) and awareness of BRONJ (Park et al. J Korean Dent Assoc 49: 2011; 389). Among them, 79.7% were aware of BRONJ. Recognition was highest among those from 25 to 35 years old (P < 0.05). In terms of work experience, those with 5-10 years experience showed the highest awareness (P < 0.05). In terms of institutions type, dental clinics showed lower awareness than general and dental hospitals (P < 0.05). It was found that 55.3% of the dental hygienists had been educated about BRONJ. Those aged 25-35 years were the most educated. In terms of institutions, dental clinic staff were the least educated. The degree of understanding about BRONJ was analysed with the average score of 6.14 points. According to these results, dental hygienists working in university hospitals and general hospitals had more opportunity to receive training than those working in dental clinics. Thus, it is considered that the development of professional training programs about BRONJ for all dental hygienists is necessary.
- Published
- 2015
3. Clinical usefulness of iQ200/iChem Velocity workstation for screening of urine culture
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Jong-Mi Lee, Doo-Jin Baek, Kang Gyun Park, Eunhee Han, and Yeon-Joon Park
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Urinary tract infection ,Urine culture ,Combination ,WBC and all small particles ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Clinical microbiology laboratories are asked to process large numbers of urine specimens for culture, but only 20–40% of them are positive. Therefore, a rapid, reliable screening method is necessary to speed up the reporting of a negative result. In this study, we evaluated the iQ200/iChem workstation, which is a combination of digital imaging software and a strip reader to predict negative urine culture. Method A total of 1942 urine specimens were processed through both culture and iQ200/ iChem workstation. We analyzed the performance using two definition of positive urine culture; one or two potential uropathogens at a concentration of ≥105 CFU/ml and ≥ 104 CFU/ml. We assessed combinations of parameters (ASP; all small particles, WBC; leukocyte, BACT; bcteria, LE; leukocyte esterase) applying various cut-offs which can achieve the negative predictive value (NPV) ≥97% and culture reduction rate ≥ 50%. Results The culture positive rate was 12.8 and 18.4% applying the criteria of ≥105 CFU/ml and ≥ 104 CFU/ml, respectively. The area under the curve (AUC) of each parameter for ≥105 CFU/ml / ≥104 CFU/ml bacteriuria was 795 /0.719 for WBC, 0.722 / 0.701 for ASP and 0.740 /0.704 for bacteria. Therefore, we investigated the combination of the parameters. With the fixed parameter of BACT≥1/HPF and positive LE, the combinations of WBC ≥ 4/HPF and ASP ≥8500/μl or WBC ≥ 6/HPF and ASP≥5500/μl showed good performance for detecting ≥105 CFU/ml uropathogen. The ranges of sensitivity, specificity, negative predictive value and culture reduction rate were 91.5–92.3%, 49.8–52.6%, 97.7–97.9% and 50.4–53.0%, respectively. However, none of the combined setting yielded acceptable range of NPV for detecting ≥104 CFU/ml uropathogen (NPV 92.9–94.9%). Enterococcus spp. was the most common uropathogen causing the false negative results (55.7%), and also the main pathogen among the positive culture of 104-5 CFU/ml bacteriuria (45%). Conclusions iQ200/iChem workstation was excellent in detection of ≥105 CFU/ml uropathogen, but unsatisfactory in detection of 104–5 CFU/ml uropathogen and Enterococcus spp. It can be useful for screening of urine specimens to reduce bacterial culture. However, notice from clinician will be necessary for specimens from the patients with high risk for UTI, such as pregnant woman, infant, elderly or immune compromised patients.
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- 2019
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4. Clinical Utility of Fecal Immunochemical Transferrin Test in Gastrointestinal Bleeding Detection
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Jong-Mi Lee, Mi Jung Park, Woong Heo, Kang Gyun Park, Yong Gyu Park, Seung Beom Han, Young-Seok Cho, and Yeon-Joon Park
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fecal occult blood test ,hemoglobin ,prematurity ,transferrin ,Microbiology ,QR1-502 - Abstract
Background: Gastrointestinal (GI) bleeding can result from various conditions, including ulcers, neoplasms and infectious enterocolitis. The aim of this study was to evaluate the utility of the fecal immunochemical transferrin test compared with the fecal Hb test in various clinical settings.Methods: A total of 1,116 clinical stool specimens submitted for fecal occult blood testing were prospectively examined using both FIT Hb and FIT Tf kits (AlfresaPharma, Japan). To verify the specificity of the two tests, stool specimens from 265 health check-up examinees were also included.Results: A review of medical records revealed that 396 patients had clinical conditions associated with GI bleeding. FIT Hb and FIT Tf results were positive in 156 (39.4%) and 137 (34.6%) cases, respectively, and an additional 194 (49.0%) cases tested positive with either FIT Hb or FIT Tf. The two tests showed a moderate strength of agreement (kappa value; 0.56). Colitis (n=71) was associated with the most GI bleedings, followed by acute gastroenteritis (n=29), GI ulcers (n=27) and GI cancers (n=15). While the first two groups had higher positive rates on FIT Tf, patients in the latter two groups had higher positive rates on FIT Hb. Notably, four of nine specimens from premature babies tested positive only on FIT Tf. The specificity of FIT Hb and FIT Tf was 100% and 99.6%, respectively.Conclusion: Concurrent use of FIT Hb and FIT Tf improved the detection rate of occult GI bleeding, especially in patients with infectious GI disease (such as colitis or gastroenteritis) and in premature babies. (Ann Clin Microbiol 2018;21:51-57)
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- 2018
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5. Fermented fish oil suppresses T helper 1/2 cell response in a mouse model of atopic dermatitis via generation of CD4+CD25+Foxp3+ T cells
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Han Sang-Chul, Kang Gyeoung-Jin, Ko Yeong-Jong, Kang Hee-Kyoung, Moon Sang-Wook, Ann Yong-Seok, and Yoo Eun-Sook
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Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Background Allergic skin inflammation such as atopic dermatitis (AD), which is characterized by pruritus and inflammation, is regulated partly through the activity of regulatory T cells (Tregs). Tregs play key roles in the immune response by preventing or suppressing the differentiation, proliferation and function of various immune cells, including CD4+ T cells. Recent studies report that fermentation has a tremendous capacity to transform chemical structures or create new substances, and the omega-3 polyunsaturated fatty acids (n-3 PUFAs) in fish oil can reduce inflammation in allergic patients. The beneficial effects of natural fish oil (NFO) have been described in many diseases, but the mechanism by which fermented fish oil (FFO) modulates the immune system and the allergic response is poorly understood. In this study, we produced FFO and tested its ability to suppress the allergic inflammatory response and to activate CD4+CD25+Foxp3+ Tregs. Results The ability of FFO and NFO to modulate the immune system was investigated using a mouse model of AD. Administration of FFO or NFO in the drinking water alleviated the allergic inflammation in the skin, and FFO was more effective than NFO. FFO treatment did increase the expression of the immune-suppressive cytokines TGF-β and IL-10. In addition, ingestion of FFO increased Foxp3 expression and the number of CD4+CD25+Foxp3+ Tregs compared with NFO. Conclusions These results suggest that the anti-allergic effect of FFO is associated with enrichment of CD4+CD25+ Foxp3+ T cells at the inflamed sites and that FFO may be effective in treating the allergic symptoms of AD.
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- 2012
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6. The CpG island methylator phenotype may confer a survival benefit in patients with stage II or III colorectal carcinomas receiving fluoropyrimidine-based adjuvant chemotherapy
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Park Cheol, Kim Hee, Chang Dong, Kim Young-Ho, Yu Hong, Lee Eui, Bae Jeong, Min Byung-Hoon, Lee Suk-Hee, Kim Kyoung-Mee, and Kang Gyeong
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Colorectal carcinoma (CRC) with CpG island methylator phenotype (CIMP) is recognized as a distinct subgroup of CRC, and CIMP status affects prognosis and response to chemotherapy. Identification of CIMP status in CRC is important for proper patient management. In Eastern countries, however, the clinicopathologic and molecular characteristics and prognosis of CRCs with CIMP are still unclear. Methods A total of 245 patients who underwent their first surgical resection for sporadic CRC were enrolled and CIMP status of the CRCs was determined using the quantitative MethyLight assay. The clinicopathologic and molecular characteristics were reviewed and compared according to CIMP status. In addition, the three-year recurrence-free survival (RFS) of 124 patients with stage II or stage III CRC was analyzed in order to assess the effectiveness of fluoropyrimidine-based adjuvant chemotherapy with respect to CIMP status. Results CIMP-high CRCs were identified in 34 cases (13.9%), and were significantly associated with proximal tumor location, poorly differentiated carcinoma, mucinous histology, and high frequencies of BRAF mutation, MGMT methylation, and MSI-high compared to CIMP-low/negative carcinomas. For patients with stage II or III CIMP-low/negative CRCs, no significant difference was found in RFS between those undergoing surgery alone and those receiving surgery with fluoropyrimidine-based adjuvant chemotherapy. However, for patients with CIMP-high CRCs, patients undergoing surgery with fluoropyrimidine-based adjuvant chemotherapy (n = 17; three-year RFS: 100%) showed significantly better RFS than patients treated with surgery alone (n = 7; three-year RFS: 71.4%) (P = 0.022). Conclusions Our results suggest that selected patients with CIMP-high CRC may benefit from fluoropyrimidine-based adjuvant chemotherapy with longer RFS. Further large scale-studies are required to confirm our results.
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- 2011
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7. Bio-Inspired Sensory Receptors for Artificial-Intelligence Perception.
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Bag A, Ghosh G, Sultan MJ, Chouhdry HH, Hong SJ, Trung TQ, Kang GY, and Lee NE
- Abstract
In the era of artificial intelligence (AI), there is a growing interest in replicating human sensory perception. Selective and sensitive bio-inspired sensory receptors with synaptic plasticity have recently gained significant attention in developing energy-efficient AI perception. Various bio-inspired sensory receptors and their applications in AI perception are reviewed here. The critical challenges for the future development of bio-inspired sensory receptors are outlined, emphasizing the need for innovative solutions to overcome hurdles in sensor design, integration, and scalability. AI perception can revolutionize various fields, including human-machine interaction, autonomous systems, medical diagnostics, environmental monitoring, industrial optimization, and assistive technologies. As advancements in bio-inspired sensing continue to accelerate, the promise of creating more intelligent and adaptive AI systems becomes increasingly attainable, marking a significant step forward in the evolution of human-like sensory perception., (© 2024 Wiley‐VCH GmbH.)
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- 2024
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8. Pyrolytic Remediation and Ecotoxicity Assessment of Fuel-Oil-Contaminated Soil.
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Choi B, Yu JS, Kang GY, Jeong TY, Jho EH, and Lee SJ
- Abstract
Oil-contaminated soil is a major societal problem for humans and the environment. In this study, the pyrolysis method was applied to oil-contaminated soil used as a landfill and gas station site in Korea. The removal efficiency of the main components of oil-contaminated soils, such as total petroleum hydrocarbons (TPH), polyaromatic hydrocarbons (PAHs), unresolved complex mixture (UCM), and alkylated PAHs (Alk-PAHs) were measured, and the effect of temperature, treatment time, and moisture content on pyrolysis efficiency was studied. In order to evaluate the risk of soil from which pollutants were removed through pyrolysis, integrated ecotoxicity was evaluated using Daphnia magna and Allivibrio fischeri . The chemical and biological measurements in this study include contaminants of emerging concerns (CECs). Results showed that the pyrolysis was more efficient with higher treatment temperatures, moisture content, and treatment times. In addition, toxicity was reduced by 99% after pyrolysis, and the degree of toxicity was evaluated more sensitively in Allivibrio fischeri than in Daphnia magna . This study shows that weathered oil-contaminated soil can be effectively treated in a relatively short time through pyrolysis, as well as provides information on efficient conditions and the assessment of ecotoxicity.
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- 2022
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9. Multicyclic topology-enhanced anticancer drug delivery.
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Ma W, Kang GY, Sun L, Meng C, Liu Y, Zheng Z, Jiang MC, Wang D, Pun SH, Yu CY, and Wei H
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- Animals, Drug Delivery Systems, Mice, Polyethylene Glycols chemistry, Polymerization, Polymers chemistry, Antineoplastic Agents, Micelles
- Abstract
Inspired by the biological use of a combination of precision and self-assembly to achieve exquisite control and diversity from 20 natural amino acids, there is considerable scope for the development of synthetic precision materials with complex architecture that can access advanced function for biomedical applications. Single cyclic polymers (SCPs) have been shown to offer different and often better performance compared to their linear analogues. Because multicyclic topology in nature offers enhanced effects relative to single cyclization, we hypothesize that multicyclic polymers (MCPs) would access unique features compared to SCPs. However, there are currently quite limited ways to efficiently synthesize MCPs and to precisely modulate the valency of cyclic units. In this work, we report for the first time a straightforward and robust strategy to synthesize MCPs with controllable valency via facile one-pot statistical reversible addition-fragmentation chain transfer (RAFT) copolymerization. We use this strategy to synthesize biocompatible MCPs based on the most classic and important biocompatible polymers of oligo (ethylene glycol) (OEG) and cyclic poly(ε-caprolactone) (cPCL), which can further self-assemble into well-defined nanostructures. We then apply these MCP-based formulations as drug delivery vehicles and demonstrate greater colloidal stability with a low critical micelle concentration (CMC) of 80.3 nM, larger drug loading capacity, higher cellular uptake efficiency, more tumor accumulation, and increased anti-tumor efficacy in murine tumor models compared to SCP-based analogues. We believe this cumulative work demonstrating facile synthesis of MCPs and demonstration of multicyclic topology-enhanced anti-cancer efficiency in vivo provides key technologies and concepts to the burgeoning field of cyclic topology-derived biomaterials., (Copyright © 2022. Published by Elsevier B.V.)
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- 2022
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10. Expanding Cyclic Topology-Based Biomedical Polymer Panel: Universal Synthesis of Hetero-"8"-Shaped Copolymers and Topological Modulation of Polymer Degradation.
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Kang GY, Ma W, Liu MZ, Luo HX, Yu CY, and Wei H
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- Drug Carriers, Drug Liberation, Macromolecular Substances, Methacrylates, Polyethylene Glycols, Micelles, Polymers
- Abstract
8-Shaped copolymers with two macrocycles connected together represent an interesting cyclic topology-derived polymer species due to the simultaneous incorporation of two cyclic moieties and the reported unique physical and chemical properties. To provide a proof-of-concept for a broad readership on biomedical polymers, a well-defined hetero-8-shaped amphiphilic copolymer, cyclic-poly(oligo(ethylene glycol)monomethyl ether methacrylate)-b-cyclic PCL (cPOEGMA-b-cPCL) is synthesized by an elegant integration of intrachain click cyclization and interchain click coupling. The potential of the self-assembled micelles of cPOEGMA-b-cPCL for controlled drug release is evaluated by in vitro drug loading and drug release, cellular uptake, cytotoxicity, and degradation studies. Most importantly, the micelles based on cPOEGMA-b-cPCL show much slower degradation profiles than the previously reported linear counterpart, POEGMA-b-PCL and tadpole-shaped analog, PEG-b-cPCL because of the presence of cyclic hydrophilic POEGMA segment. Therefore, this study not only develops a robust strategy for a universal precise synthesis of well-defined hetero-8-shaped copolymers based on diverse vinyl and ring-structured monomers, but also reveals the first modulation of polymer degradation property by topological control of the nondegradable moiety in the polymer construct through advanced macromolecular engineering., (© 2021 Wiley-VCH GmbH.)
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- 2021
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11. Addiction Problems, Aggression, and Quality of Life in People with Different Occupations in South Korea.
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Wee H and Kang GY
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Addiction is related to aggression and quality of life. This study examined the relationship between these three factors according to occupation group in a mixed urban/rural area to better understand adult addiction problems. This study was a secondary data analysis of cross-sectional data collected by a 2017 regional survey of adults living in Gunsan City, South Korea. The survey included 500 people split into the unemployed (Group1), full-time homemakers (Group2), and primary (Group3), secondary (Group4), and tertiary (Group5) industry workers. Addiction problems and aggression were positively correlated ( p < 0.01). Aggression and alcohol use disorder were correlated in Group3 (r = 0.31), Group4 (r = 0.34), and Group5 (r = 0.32), and aggression and smartphone addiction were correlated in Group2 (r = 0.39) and Group4 (r = 0.31). Problem gambling was correlated with aggression in Group5 (r = 0.39). A negative relationship between quality of life and alcohol use disorder occurred in Group1 (r = -0.36). According to the occupation group, the relationships between addiction problems, aggression, and quality of life were different. These findings suggest that addiction management for adults should be implemented in consideration of occupation groups.
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- 2021
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12. Comment on "Clinical characteristics of spontaneous coronary artery dissection in young female patients with acute myocardial infarction in Korea".
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Kang GY
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- Dissection, Female, Humans, Republic of Korea epidemiology, Coronary Vessel Anomalies complications, Coronary Vessel Anomalies diagnostic imaging, Myocardial Infarction etiology
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- 2021
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13. Endogenous DEL-1 restrains melanoma lung metastasis by limiting myeloid cell-associated lung inflammation.
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Hyun YM, Seo SU, Choi WS, Kwon HJ, Kim DY, Jeong S, Kang GY, Yi E, Kim M, Ryu HJ, Looney MR, Choi EY, and Kim HS
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- Animals, Inflammation, Mice, Mice, Inbred C57BL, Neutrophils, Lung Neoplasms pathology, Melanoma, Experimental pathology, Pneumonia etiology
- Abstract
Distant metastasis represents the primary cause of cancer-associated death. Pulmonary metastasis is most frequently seen in many cancers, largely driven by lung inflammation. Components from primary tumor or recruited leukocytes are known to facilitate metastasis formation. However, contribution of target site-specific host factor to metastasis is poorly understood. Here, we show that developmental endothelial locus-1 (DEL-1), an anti-inflammatory factor abundant in the lung and down-regulated by inflammatory insults, protects from melanoma lung metastasis independently of primary tumor development and systemic immunosurveillance. DEL-1 deficiency is associated with gene profiles that favor metastatic progression with inflammation and defective immunosurveillance. Mechanistically, DEL-1 deficiency primarily influences Ly6G
+ neutrophil accumulation in lung metastatic niche, leading to IL-17A up-regulation from γδ T cells and reduced antimetastatic NK cells. In support, neutrophil depletion or recombinant DEL-1 treatment profoundly reverses these effects. Thus, our results identify DEL-1 as a previously unrecognized link between tumor-induced inflammation and pulmonary metastasis., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)- Published
- 2020
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14. Effect of Korean nursing students' experience of incivility in clinical settings on critical thinking.
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Kim SA, Hong E, Kang GY, Brandt C, and Kim Y
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Clinical experience is essential to helping nursing students to achieve and practice professional knowledge and skills. Published reports indicate nursing students often experience incivility during clinical practice. The purpose of this study was to investigate nursing student incivility experience during their clinical rotations and the relationship of these experiences with their critical thinking dispositions. A cross-sectional descriptive correlational study design was utilized. Data were collected from junior (n = 195) and senior (n = 180) students in a Bachelor of Science in Nursing (BSN) program in Seoul, Korea between October 15, 2017 and November 20, 2017 using a self-administered survey. Three instruments were used in the survey: six sociodemographic questions, the 13-item Korean version of Uncivil Behavior in Clinical Nursing Education (K-UBCNE) and the 27-item Yoon Critical Thinking Disposition (YCTD) tool. Data analysis revealed junior students reported significantly more incivility from nurses than the senior students (p = .038) during clinical learning experiences. Among YCTD subscales, the Prudence (p = .007) and Self-Confidence critical thinking (p = .007) scores from the senior nursing students were significantly higher than the junior students' scores. No significant relationship was found between experience of incivility and critical thinking disposition scores. Based on the study results, nursing educators, staff nurses, and administrators/managers in nursing should identify incivility toward nursing students during clinical practicums and especially toward junior nursing students. Additional investigation of the relationship between critical thinking and experiences of incivility is warranted, including longitudinal investigations and qualitative studies among junior nursing students to understand their personal experience of incivility in the clinical setting. Findings could inform the development of targeted programs to reduce clinical incivility., (© 2020 The Author(s).)
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- 2020
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15. 3D Imaging of the Transparent Mycobacterium tuberculosis -Infected Lung Verifies the Localization of Innate Immune Cells With Granuloma.
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Kang GY, Rhyu HJ, Choi HH, Shin SJ, and Hyun YM
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- Animals, Granuloma, Imaging, Three-Dimensional, Immunity, Innate, Lung diagnostic imaging, Mice, Mycobacterium tuberculosis
- Abstract
Using a novel tissue-clearing method, we aimed to visualize the three-dimensional (3D) distribution of immune cells within Mycobacterium tuberculosis (Mtb)-infected mice lungs. Ethyl cinnamate-based tissue clearing of Mtb-infected mice lungs was performed to obtain transparent lung samples, which were then imaged using a light sheet fluorescence microscope. Using the 3D images, we performed quantitative analysis of the immune cell population within multiple granulomas. In addition, to compare the data from the tissue clearing method, we performed histopathological and immunofluorescence analyses, and flow cytometry. We then created 3D images of the Mtb-infected lung that successfully demonstrated the distribution of blood vessels, immune cells, and granulomas. Since the immune cells within a granuloma could be separately selected and counted, the immune cell population within a specific lesion could be quantified. In addition, macroscopic analysis, e.g., the size or shape of a granuloma, as well as microscopic analysis could be performed as intact lung samples were used. The use of the tissue clearing method in infected lungs could be a novel modality for understanding the role of the immune system in the pathogenesis of tuberculosis., (Copyright © 2020 Kang, Rhyu, Choi, Shin and Hyun.)
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- 2020
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16. Risk Factors for Pulmonary Embolism.
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Kang GY and Zhang HQ
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- Humans, Retrospective Studies, Risk Factors, Vascular Surgical Procedures, Pulmonary Embolism
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- 2020
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17. 'Pulmonary embolism: an often forgotten differential diagnosis for abdominal pain'.
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Kang GY and Zhang HQ
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- Diagnosis, Differential, Humans, Abdominal Pain, Pulmonary Embolism
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- 2020
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18. Quantification of the Dynamic Phosphorylation Process of ERK Using Stable Isotope Dilution Selective Reaction Monitoring Mass Spectrometry.
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Lee N, Lee JW, Kang GY, Park SH, and Kim KP
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- Animals, Extracellular Signal-Regulated MAP Kinases chemistry, Extracellular Signal-Regulated MAP Kinases genetics, Glutamic Acid chemistry, Glutamic Acid genetics, HeLa Cells, Humans, Mitogen-Activated Protein Kinase Kinases chemistry, Mitogen-Activated Protein Kinase Kinases genetics, Mutation, PC12 Cells, Phosphorylation, Rats, Signal Transduction, Threonine chemistry, Threonine genetics, Tyrosine chemistry, Tyrosine genetics, Extracellular Signal-Regulated MAP Kinases metabolism, Glutamic Acid metabolism, Mitogen-Activated Protein Kinase Kinases metabolism, Threonine metabolism, Tyrosine metabolism
- Abstract
Mitogen-activated protein (MAP) kinase signaling is critical for various cellular responses, including cell proliferation, differentiation, and cell death. The MAP kinase cascade is conserved in the eukaryotic kingdom as a three-tiered kinase module-MAP kinase kinase kinase, MAP kinase kinase, and MAP kinase-that transduces signals via sequential phosphorylation upon stimulation. Dual phosphorylation of MAP kinase on the conserved threonine-glutamic acid-tyrosine (TEY) motif is essential for its catalytic activity and signal activation; however, the molecular mechanism by which the two residues are phosphorylated remains elusive. In the present study, the pattern of dual phosphorylation of extracellular signal-regulated kinase (ERK) is profiled on the TEY motif using stable isotope dilution (SID)-selective reaction monitoring (SRM) mass spectrometry (MS) to elucidate the order and magnitude of endogenous ERK phosphorylation in cellular model systems. The SID-SRM-MS analysis of phosphopeptides demonstrates that tyrosine phosphorylation in the TEY motif is dynamic, while threonine phosphorylation is static. Analyses of the mono-phosphorylatable mutants ERK
T202A and ERKY204F indicate that phosphorylation of tyrosine is not affected by the phosphorylation state of threonine, while threonine phosphorylation depends on tyrosine phosphorylation. The data suggest that dual phosphorylation of ERK is a highly ordered and restricted mechanism determined by tyrosine phosphorylation., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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19. Cleaved Cochlin Sequesters Pseudomonas aeruginosa and Activates Innate Immunity in the Inner Ear.
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Jung J, Yoo JE, Choe YH, Park SC, Lee HJ, Lee HJ, Noh B, Kim SH, Kang GY, Lee KM, Yoon SS, Jang DS, Yoon JH, Hyun YM, and Choi JY
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- Animals, Bacterial Adhesion, Disease Models, Animal, Labyrinthitis pathology, Mice, Mice, Knockout, Pseudomonas Infections pathology, Ear, Inner immunology, Ear, Inner microbiology, Extracellular Matrix Proteins metabolism, Immunity, Innate, Labyrinthitis immunology, Pseudomonas Infections immunology, Pseudomonas aeruginosa immunology
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In the inner ear, endolymph fluid surrounds the organ of Corti, which is important for auditory function; notably, even slight environmental changes mediated by trauma or infection can have significant consequences. However, it is unclear how the immune response is modulated in these tissues. Here, we report the local immune surveillance role of cleaved cochlin LCCL (Limulus factor C, Cochlin, and Lgl1) during Pseudomonas aeruginosa infection in the cochlea. Upon infection, the LCCL domain is cleaved from cochlin and secreted into the perilymph. This cleaved fragment sequesters infiltrating bacteria in the scala tympani and subsequently recruits resident immune cells to eliminate the bacteria. Importantly, hearing loss in a cochlin knockout mouse model is remedied by treatment with a cochlin LCCL peptide. These findings suggest cleaved cochlin LCCL constitutes a critical factor in innate immunity and auditory function and may be a potential therapeutic target to treat chronic otitis media-induced hearing loss., (Copyright © 2019 Elsevier Inc. All rights reserved.)
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- 2019
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20. Identification of molecular signatures involved in radiation-induced lung fibrosis.
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Jin H, Kang GY, Jeon S, Kim JM, Park YN, Cho J, and Lee YS
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- A549 Cells, Animals, Cell Line, Epithelial-Mesenchymal Transition radiation effects, Humans, Lung metabolism, Lung pathology, Lung radiation effects, Male, Mice, Inbred C57BL, Pulmonary Fibrosis etiology, Pulmonary Fibrosis pathology, Radiation Pneumonitis etiology, Radiation Pneumonitis pathology, Radiotherapy adverse effects, Transcriptome radiation effects, Up-Regulation radiation effects, Fibrinogen genetics, Microtubule-Associated Proteins genetics, Pulmonary Fibrosis genetics, Radiation Pneumonitis genetics
- Abstract
In radiotherapy, radiation (IR)-induced lung fibrosis has severe and dose-limiting side effects. To elucidate the molecular effects of IR fibrosis, we examined the fibrosis process in irradiated mouse lung tissues. High focal IR (90 Gy) was exposed to a 3-mm volume of the left lung in C57BL6 mice. In the diffused irradiation, 20 Gy dose delivered with a 7-mm collimator almost covered the entire left lung. Histological examination for lung tissues of both irradiated and neighboring regions was done for 4 weeks after irradiation. Long-term effects (12 months) of 20Gy IR were compared on a diffuse region of the left lung and non-irradiated right lung. Fibrosis was initiated as early as 2 weeks after IR in the irradiated lung region and neighboring region. Upregulation of gtse1 in both 90Gy-irradiated and neighboring regions was observed. Upregulation of fgl1 in both 20Gy diffused irradiated and non-irradiated lungs was identified. When gtse1 or flg1 was knock-downed, TGFβ or IR-induced epithelial-mesenchymal transition was inhibited, accompanied with the inhibition of cellular migration, suggesting fibrosis responsible genes. Immunofluorescence analysis using mouse fibrotic lung tissues suggested that fibrotic regions showed increased expressions of Gtse1 and Fgl1, indicating novel molecular signatures of gtse1and fgl1 for IR-induced lung fibrosis. Even though their molecular mechanisms and IR doses or irradiated volumes for lung fibrosis may be different, these genes may be novel targets for understanding IR-induced lung fibrosis and in treatment strategies. KEY MESSAGES: Upregulation of gtse1 by 90Gy focal irradiation and upregulation of fgl1 by 20Gy diffused irradiation are identified in mouse lung fibrosis model. Gtse1 and Fgl1 are involved in radiation or TGFβ-induced epithelial-mesenchymal transition. Radiation-induced fibrotic regions of mouse lungs showed increased expressions of Gtse1 and Fgl1. Gtse1 and Fgl1 are suggested to be novel targets for radiation-induced lung fibrosis.
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- 2019
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21. Identification of radiation response genes and proteins from mouse pulmonary tissues after high-dose per fraction irradiation of limited lung volumes.
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Jin H, Jeon S, Kang GY, Lee HJ, Cho J, and Lee YS
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- Animals, Dose-Response Relationship, Radiation, Male, Mice, Mice, Inbred C57BL, Radiation Dose Hypofractionation, Radiation Pneumonitis etiology, Gene Expression Regulation radiation effects, Lung metabolism, Lung radiation effects, Proteome metabolism, Radiation Pneumonitis metabolism, Radiosurgery adverse effects
- Abstract
Purpose: The molecular effects of focal exposure of limited lung volumes to high-dose per fraction irradiation (HDFR) such as stereotactic body radiotherapy (SBRT) have not been fully characterized. In this study, we used such an irradiation system and identified the genes and proteins after HDFR to mouse lung, similar to those associated with human therapy., Methods and Materials: High focal radiation (90 Gy) was applied to a 3-mm volume of the left lung of C57BL6 mice using a small-animal stereotactic irradiator. As well as histological examination for lungs, a cDNA micro array using irradiated lung tissues and a protein array of sera were performed until 4 weeks after irradiation, and radiation-responsive genes and proteins were identified. For comparison, the long-term effects (12 months) of 20 Gy radiation wide-field dose to the left lung were also investigated., Results: The genes ermap, epb4.2, cd200r3 (up regulation) and krt15, hoxc4, gdf2, cst9, cidec, and bnc1 (down-regulation) and the proteins of AIF, laminin, bNOS, HSP27, β-amyloid (upregulation), and calponin (downregulation) were identified as being responsive to 90 Gy HDFR. The gdf2, cst9, and cidec genes also responded to 20 Gy, suggesting that they are universal responsive genes in irradiated lungs. No universal proteins were identified in both 90 Gy and 20 Gy. Calponin, which was downregulated in protein antibody array analysis, showed a similar pattern in microarray data, suggesting a possible HDFR responsive serum biomarker that reflects gene alteration of irradiated lung tissue. These genes and proteins also responded to the lower doses of 20 Gy and 50 Gy HDFR., Conclusions: These results suggest that identified candidate genes and proteins are HDFR-specifically expressed in lung damage induced by HDFR relevant to SBRT in humans.
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- 2017
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22. NEDDylation promotes stress granule assembly.
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Jayabalan AK, Sanchez A, Park RY, Yoon SP, Kang GY, Baek JH, Anderson P, Kee Y, and Ohn T
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- Cell Line, Tumor, Cytoplasmic Granules genetics, Cytoplasmic Granules metabolism, HEK293 Cells, HeLa Cells, Humans, Lysine metabolism, NEDD8 Protein metabolism, Osteoblasts cytology, Osteoblasts drug effects, Osteoblasts metabolism, Oxidative Stress, Polyribosomes drug effects, Ribonucleoproteins genetics, Ribonucleoproteins metabolism, Serine-Arginine Splicing Factors metabolism, Ubiquitin-Conjugating Enzymes genetics, Ubiquitin-Conjugating Enzymes metabolism, Arsenites toxicity, Cytoplasmic Granules drug effects, NEDD8 Protein genetics, Protein Biosynthesis drug effects, Serine-Arginine Splicing Factors genetics
- Abstract
Stress granules (SGs) harbour translationally stalled messenger ribonucleoproteins and play important roles in regulating gene expression and cell fate. Here we show that neddylation promotes SG assembly in response to arsenite-induced oxidative stress. Inhibition or depletion of key components of the neddylation machinery concomitantly inhibits stress-induced polysome disassembly and SG assembly. Affinity purification and subsequent mass-spectrometric analysis of Nedd8-conjugated proteins from translationally stalled ribosomal fractions identified ribosomal proteins, translation factors and RNA-binding proteins (RBPs), including SRSF3, a previously known SG regulator. We show that SRSF3 is selectively neddylated at Lys85 in response to arsenite. A non-neddylatable SRSF3 (K85R) mutant do not prevent arsenite-induced polysome disassembly, but fails to support the SG assembly, suggesting that the neddylation pathway plays an important role in SG assembly.
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- 2016
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23. Focal exposure of limited lung volumes to high-dose irradiation down-regulated organ development-related functions and up-regulated the immune response in mouse pulmonary tissues.
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Kim BY, Jin H, Lee YJ, Kang GY, Cho J, and Lee YS
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- Animals, Dose-Response Relationship, Radiation, Down-Regulation, Gene Expression Profiling, Gene Ontology, Immunity genetics, Immunity radiation effects, Lung growth & development, Lung immunology, Male, Mice, Pulmonary Fibrosis, Radiosurgery, Up-Regulation, Gene Expression Regulation radiation effects, Lung radiation effects
- Abstract
Background: Despite the emergence of stereotactic body radiotherapy (SBRT) for treatment of medically inoperable early-stage non-small-cell lung cancer patients, the molecular effects of focal exposure of limited lung volumes to high-dose radiation have not been fully characterized. This study was designed to identify molecular changes induced by focal high-dose irradiation using a mouse model of SBRT., Results: Central areas of the mouse left lung were focally-irradiated (3 mm in diameter) with a single high-dose of radiation (90 Gy). Temporal changes in gene expression in the irradiated and non-irradiated neighboring lung regions were analyzed by microarray. For comparison, the long-term effect (12 months) of 20 Gy radiation on a diffuse region of lung was also measured. The majority of genes were down-regulated in the focally-irradiated lung areas at 2 to 3 weeks after irradiation. This pattern of gene expression was clearly different than gene expression in the diffuse region of lungs exposed to low-dose radiation. Ontological and pathway analyses indicated these down-regulated genes were mainly associated with organ development. Although the number was small, genes that were up-regulated after focal irradiation were associated with immune-related functions. The temporal patterns of gene expression and the associated biological functions were also similar in non-irradiated neighboring lung regions, although statistical significance was greatly reduced when compared with those from focally-irradiated areas of the lung. From network analysis of temporally regulated genes, we identified inter-related modules associated with diverse functions, including organ development and the immune response, in both the focally-irradiated regions and non-irradiated neighboring lung regions., Conclusions: Focal exposure of lung tissue to high-dose radiation induced expression of genes associated with organ development and the immune response. This pattern of gene expression was also observed in non-irradiated neighboring areas of lung tissue, indicating a global lung response to focal high-dose irradiation.
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- 2016
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24. Heat shock factor 1, an inhibitor of non-homologous end joining repair.
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Kang GY, Kim EH, Lee HJ, Gil NY, Cha HJ, and Lee YS
- Subjects
- Animals, Antigens, Nuclear genetics, Cell Line, Tumor, Cells, Cultured, DNA Damage, DNA-Binding Proteins genetics, Embryo, Mammalian cytology, Female, Fibroblasts cytology, Fibroblasts radiation effects, HEK293 Cells, Heat Shock Transcription Factors, Humans, Immunoblotting, Immunohistochemistry, Ku Autoantigen, Mammary Neoplasms, Animal genetics, Mammary Neoplasms, Animal metabolism, Mice, Knockout, Radiation, Ionizing, Rats, Sprague-Dawley, Transcription Factors genetics, Antigens, Nuclear metabolism, DNA End-Joining Repair, DNA-Binding Proteins metabolism, Fibroblasts metabolism, Transcription Factors metabolism
- Abstract
A novel role for HSF1 as an inhibitor of non-homologous end joining (NHEJ) repair activity was identified. HSF1 interacted directly with both of the N-terminal sequences of the Ku70 and Ku86 proteins, which inhibited the endogenous heterodimeric interaction between Ku70 and Ku86. The blocking of the Ku70 and Ku86 interaction by HSF1 induced defective NHEJ repair activity and ultimately activated genomic instability after ionizing radiation (IR), which was similar to effects seen in Ku70 or Ku80 knockout cells. The binding activity between HSF1 and Ku70 or Ku86 was dependent on DNA damage response such as IR exposure, but not on the heat shock mediated transcriptional activation of HSF1. Moreover, the posttranslational modification such as phosphorylation, acetylation and sumoylation of HSF1 did not alter the binding activities of HSF1-Ku70 or HSF1-Ku86. Furthermore, the defect in DNA repair activity by HSF1 was observed regardless of p53 status. Rat mammary tumors derived using dimethylbenz(a)anthracence revealed that high levels of HSF1 expression which correlate with aggressive malignancy, interfered with the binding of Ku70-Ku80. This data suggests that HSF1 interacts with both Ku70 and Ku86 to induce defective NHEJ repair activity and genomic instability, which in turn suggests a novel mechanism of HSF1-mediated cellular carcinogenesis.
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- 2015
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25. Survey on awareness and perceptions of bisphosphonate-related osteonecrosis of the jaw in dental hygienists in Seoul.
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Mah YJ, Kang GY, and Kim SJ
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- Adult, Dental Clinics, Dental Hygienists psychology, Dental Service, Hospital, Education, Continuing, Hospitals, General, Hospitals, Special, Hospitals, Teaching, Humans, Informed Consent, Inservice Training, Interprofessional Relations, Medical History Taking, Professional Practice, Republic of Korea, Time Factors, Workplace, Attitude of Health Personnel, Bisphosphonate-Associated Osteonecrosis of the Jaw physiopathology, Dental Hygienists education
- Abstract
We investigated awareness in dental hygienists of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in patients with osteoporosis and cancer and assessed the situation in systemic history investigations to broaden the scope of the dental hygienists' BRONJ awareness as a basis for contributing to preventing this disease. The study was carried out through a survey; 217 dental hygienists responded to the survey. They worked at 12 university and general hospitals, 10 dental hospitals and 35 dental clinics, for a total of 57 institutions in Seoul. The survey consisted of 37 questions: general characteristics (J Oral Maxillofac Surg 65: 2007; 369), systemic history investigations (Ruggiero et al. J Oral Maxillofac Surg 62: 2004; 527) and awareness of BRONJ (Park et al. J Korean Dent Assoc 49: 2011; 389). Among them, 79.7% were aware of BRONJ. Recognition was highest among those from 25 to 35 years old (P < 0.05). In terms of work experience, those with 5-10 years experience showed the highest awareness (P < 0.05). In terms of institutions type, dental clinics showed lower awareness than general and dental hospitals (P < 0.05). It was found that 55.3% of the dental hygienists had been educated about BRONJ. Those aged 25-35 years were the most educated. In terms of institutions, dental clinic staff were the least educated. The degree of understanding about BRONJ was analysed with the average score of 6.14 points. According to these results, dental hygienists working in university hospitals and general hospitals had more opportunity to receive training than those working in dental clinics. Thus, it is considered that the development of professional training programs about BRONJ for all dental hygienists is necessary., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2015
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26. SIRT2 regulates tumour hypoxia response by promoting HIF-1α hydroxylation.
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Seo KS, Park JH, Heo JY, Jing K, Han J, Min KN, Kim C, Koh GY, Lim K, Kang GY, Uee Lee J, Yim YH, Shong M, Kwak TH, and Kweon GR
- Subjects
- Animals, Cell Line, Tumor, Energy Metabolism genetics, Female, HeLa Cells, Humans, Hydroxylation, Mice, Mice, Inbred BALB C, Mice, Nude, NAD metabolism, Prolyl Hydroxylases metabolism, Protein Binding, Protein Stability, RNA Interference, RNA, Small Interfering, Sirtuin 2 genetics, Ubiquitination, Cell Hypoxia genetics, Hypoxia-Inducible Factor 1, alpha Subunit metabolism, Sirtuin 2 metabolism
- Abstract
Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that has a central role in the regulation of tumour metabolism under hypoxic conditions. HIF-1α stimulates glycolytic energy production and promotes tumour growth. Sirtuins are NAD(+)-dependent protein deacetylases that regulate cellular metabolism in response to stress; however, their involvement in the hypoxic response remains unclear. In this study, it is shown that SIRT2-mediated deacetylation of HIF-1α regulates its stability in tumour cells. SIRT2 overexpression destabilized HIF-1α under hypoxic conditions, whereas HIF-1α protein levels were high in SIRT2-deficient cells. SIRT2 directly interacted with HIF-1α and deacetylated Lys709 of HIF-1α. Deacetylation of HIF-1α by SIRT2 resulted in increased binding affinity for prolyl hydroxylase 2, a key regulator of HIF-1α stability, and increased HIF-1α hydroxylation and ubiquitination. Moreover, a pharmacological agent that increased the intracellular NAD(+)/NADH ratio led to the degradation of HIF-1α by increasing SIRT2-mediated deacetylation and subsequent hydroxylation. These findings suggest that SIRT2-mediated HIF-1α deacetylation is critical for the destablization of HIF-1α and the hypoxic response of tumour cells.
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- 2015
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27. A novel biosensor-based microarray assay for the visualized detection of CYP2C19 *2, *3, *4 and *5 polymorphisms.
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Xiao JM, Xiong J, Kang GY, Li Q, Jiang ZY, Chen JH, Wang LL, Yao FD, and Song JW
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- Humans, Sensitivity and Specificity, Biosensing Techniques, Cytochrome P-450 CYP2C19 genetics, Oligonucleotide Array Sequence Analysis, Polymorphism, Genetic genetics
- Abstract
Background: A number of studies have indicated that the conversion of clopidogrel to its active metabolite is reduced in patients who carry the CYP2C19 *2, *3, *4 or *5 loss-of-function allele, resulting in decreased response of platelet to clopidogrel treatment and worse cardiovascular outcome. The aim of this study was to develop a novel biosensor-based microarray to visually detect CYP2C19 polymorphisms., Methods: The target DNA was amplified from regions flanking the respective alleles using 5'-biotinylated reverse primer, and plasmids were prepared for the respective alleles. High stringency reversed hybridization, horseradish peroxidase-labeled streptavidin reaction, and color development, with multiple washes in different steps, were carried out and the results were recorded with an optical camera. The gene chips were tested for specificity, detection limit, intra- and inter-batch variations using the constructed plasmids. Finally, 88 clinical samples were assayed with this microarray as well as direct sequencing., Results: The results could be seen with the naked eye. Concordance tests indicated that for alleles *2, *3, *4, and *5, the κ values between this assay and plasmids all reached 1.000. The detection limit was 5×10² cells/mL. Concordance test between direct sequencing and the microarray assay using 88 clinical samples gave rise to the κ value of 0.983, and p<0.01, indicating very high concordance., Conclusions: This novel biosensor-based microarray assay can amplify the signal in situ so that it can be detected by simple instruments or even the naked eyes. It is promising for clinical application in hospital laboratories.
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- 2015
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28. 1950 MHz Electromagnetic Fields Ameliorate Aβ Pathology in Alzheimer's Disease Mice.
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Jeong YJ, Kang GY, Kwon JH, Choi HD, Pack JK, Kim N, Lee YS, and Lee HJ
- Subjects
- Alzheimer Disease pathology, Alzheimer Disease physiopathology, Amyloid Precursor Protein Secretases metabolism, Amyloid beta-Peptides metabolism, Amyloid beta-Protein Precursor genetics, Amyloid beta-Protein Precursor metabolism, Animals, Aspartic Acid Endopeptidases metabolism, Astrocytes pathology, Astrocytes physiology, Avoidance Learning physiology, Disease Models, Animal, Female, Gene Expression, Humans, Maze Learning physiology, Memory Disorders pathology, Memory Disorders physiopathology, Memory Disorders therapy, Mice, Transgenic, Microglia pathology, Microglia physiology, Motor Activity physiology, Presenilin-1 genetics, Presenilin-1 metabolism, Alzheimer Disease therapy, Magnetic Field Therapy methods
- Abstract
The involvement of radiofrequency electromagnetic fields (RF-EMF) in the neurodegenerative disease, especially Alzheimer's disease (AD), has received wide consideration, however, outcomes from several researches have not shown consistency. In this study, we determined whether RF-EMF influenced AD pathology in vivo using Tg-5xFAD mice as a model of AD-like amyloid β (Aβ) pathology. The transgenic (Tg)-5xFAD and wild type (WT) mice were chronically exposed to RF-EMF for 8 months (1950 MHz, SAR 5W/kg, 2 hrs/day, 5 days/week). Notably, chronic RFEMF exposure significantly reduced not only Aβ plaques, APP, and APP carboxyl-terminal fragments (CTFs) in whole brain including hippocampus and entorhinal cortex but also the ratio of Aβ42 and Aβ40 peptide in the hippocampus of Tg-5xFAD mice. We also found that parenchymal expression of β-amyloid precursor protein cleaving enzyme 1(BACE1) and neuroinflammation were inhibited by RF-EMF exposure in Tg-5xFAD. In addition, RF-EMF was shown to rescue memory impairment in Tg-5xFAD. Moreover, gene profiling from microarray data using hippocampus of WT and Tg- 5xFAD following RF-EMF exposure revealed that 5 genes (Tshz2, Gm12695, St3gal1, Isx and Tll1), which are involved in Aβ, are significantly altered inTg-5xFAD mice, exhibiting different responses to RF-EMF in WT or Tg-5xFAD mice; RF-EMF exposure in WT mice showed similar patterns to control Tg-5xFAD mice, however, RF-EMF exposure in Tg- 5xFAD mice showed opposite expression patterns. These findings indicate that chronic RF-EMF exposure directly affects Aβ pathology in AD but not in normal brain. Therefore, RF-EMF has preventive effects against AD-like pathology in advanced AD mice with a high expression of Aβ, which suggests that RF-EMF can have a beneficial influence on AD.
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- 2015
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29. 2,4-Bis(4-hydroxybenzyl)phenol inhibits heat shock transcription factor 1 and sensitizes lung cancer cells to conventional anticancer modalities.
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Yoon T, Kang GY, Han AR, Seo EK, and Lee YS
- Subjects
- Apoptosis drug effects, Benzhydryl Compounds chemistry, Caspase 3 metabolism, HSP27 Heat-Shock Proteins analysis, HSP27 Heat-Shock Proteins genetics, HSP27 Heat-Shock Proteins metabolism, HSP70 Heat-Shock Proteins analysis, HSP70 Heat-Shock Proteins genetics, HSP70 Heat-Shock Proteins metabolism, Heat Shock Transcription Factors, Humans, Lung Neoplasms, Molecular Structure, Phenols chemistry, Polymerase Chain Reaction, Benzhydryl Compounds pharmacology, DNA-Binding Proteins antagonists & inhibitors, Phenols pharmacology, Transcription Factors antagonists & inhibitors
- Abstract
Heat shock factor 1 (HSF1) is a transcription factor that regulates expression of heat shock protein (HSP) genes in response to stress. HSPs are expressed at high levels in a wide range of tumors. It has been reported that HSF1 and HSPs are associated closely in tumorigenesis. In the present study, a screen was performed using a luciferase reporter under the control of a heat shock element to find inhibitors of HSF1 activity, and 2,4-bis(4-hydroxybenzyl)phenol (1), isolated from the rhizomes of Gastrodia elata, was identified as an active compound. This substance effectively inhibited HSF1 activity and decreased levels of HSP27 and HSP70. Compound 1 induced the degradation of HSF1 protein through dephosphorylation of HSF1 on S326, which decreases HSF1 protein stability. In addition, 1 also induced growth arrest and apoptosis of NCI-H460 human lung cancer cells. Markers of apoptosis, such as cleaved PARP and cleaved caspase-3, were detected after treatment with 1. Furthermore, cotreatment with 1 and conventional anticancer modalities such as paclitaxel, cisplatin, or ionizing radiation potentiated their effects on lung cancer cells. These results suggest that inhibition of HSF1 by 1 may help overcome resistance to conventional anticancer modalities in HSF1-overexpressed cancer cells.
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- 2014
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30. Increased 26S proteasome non-ATPase regulatory subunit 1 in the aqueous humor of patients with age-related macular degeneration.
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Lee H, Choi AJ, Kang GY, Park HS, Kim HC, Lim HJ, and Chung H
- Subjects
- Aged, Aged, 80 and over, Biomarkers metabolism, Blotting, Western, Case-Control Studies, Female, Hexosyltransferases, Humans, Male, Middle Aged, Proteomics, Spectrometry, Mass, Electrospray Ionization, Aqueous Humor enzymology, Macular Degeneration enzymology, Proteasome Endopeptidase Complex metabolism
- Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the world. Evidence indicates that the suppression of the ubiquitin-proteasome system (UPS) contributes to the accumulation of toxic proteins and inflammation in retinal pigment epithelium (RPE), the functional abnormalities and/or the degeneration of which are believed to be the initiators and major pathologies of AMD. To identify new protein associations with the altered UPS in AMD, we used LC-ESI-MS/MS to perform a proteomic analysis of the aqueous humor (AH) of AMD patients and matched control subjects. Six UPS-related proteins were present in the AH of the patients and control subjects. Four of the proteins, including 26S proteasome non-ATPase regulatory subunit 1 (Rpn2), were increased in patients, according to semi-quantitative proteomic profiling. An LC-MRM assay revealed a significant increase of Rpn2 in 15 AMD patients compared to the control subjects, suggesting that this protein could be a biomarker for AMD.
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- 2014
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31. Exosomal proteins in the aqueous humor as novel biomarkers in patients with neovascular age-related macular degeneration.
- Author
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Kang GY, Bang JY, Choi AJ, Yoon J, Lee WC, Choi S, Yoon S, Kim HC, Baek JH, Park HS, Lim HJ, and Chung H
- Subjects
- Animals, Cell Line, Chromatography, Liquid, Humans, Mice, Mice, Inbred C57BL, Spectrometry, Mass, Electrospray Ionization, Aqueous Humor metabolism, Biomarkers metabolism, Exosomes metabolism, Eye Proteins metabolism, Wet Macular Degeneration metabolism
- Abstract
Age-related macular degeneration (AMD) describes the progressive degeneration of the retinal pigment epithelium (RPE), retina, and choriocapillaris and is the leading cause of blindness in people over 50. The molecular mechanisms underlying this multifactorial disease remain largely unknown. To uncover novel secretory biomarkers related to the pathogenesis of AMD, we adopted an integrated approach to compare the proteins identified in the conditioned medium (CM) of cultured RPE cells and the exosomes derived from CM and from the aqueous humor (AH) of AMD patients by LC-ESI-MS/MS. Finally, LC-MRM was performed on the AH from patients and controls, which revealed that cathepsin D, cytokeratin 8, and four other proteins increased in the AH of AMD patients. The present study has identified potential biomarkers and therapeutic targets for AMD treatment, such as proteins related to the autophagy-lysosomal pathway and epithelial-mesenchymal transition, and demonstrated a novel and effective approach to identifying AMD-associated proteins that might be secreted by RPE in vivo in the form of exosomes. The proteomics-based characterization of this multifactorial disease could help to match a particular marker to particular target-based therapy in AMD patients with various phenotypes.
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- 2014
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32. MMP9 processing of HSPB1 regulates tumor progression.
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Choi SH, Lee HJ, Jin YB, Jang J, Kang GY, Lee M, Kim CH, Kim J, Yoon SS, Lee YS, and Lee YJ
- Subjects
- Adenocarcinoma genetics, Adenocarcinoma metabolism, Adenocarcinoma pathology, Animals, Carcinogenesis genetics, Carcinogenesis metabolism, Cell Movement, Cell Proliferation, Disease Progression, Endothelial Cells metabolism, HSP27 Heat-Shock Proteins genetics, Heat-Shock Proteins, Humans, Lung Neoplasms genetics, Lung Neoplasms metabolism, Lung Neoplasms pathology, Matrix Metalloproteinase 9 genetics, Mice, Molecular Chaperones, Phosphorylation, Receptors, Vascular Endothelial Growth Factor genetics, Sarcoma genetics, Sarcoma metabolism, Sarcoma pathology, Soft Tissue Neoplasms genetics, Soft Tissue Neoplasms metabolism, Soft Tissue Neoplasms pathology, Carcinogenesis pathology, HSP27 Heat-Shock Proteins metabolism, Matrix Metalloproteinase 9 metabolism, Receptors, Vascular Endothelial Growth Factor metabolism
- Abstract
Matrix metalloproteinases regulate pathophysiological events by processing matrix proteins and secreted proteins. Previously, we demonstrated that soluble heat shock protein B1 (HSPB1) is released primarily from endothelial cells (ECs) and regulates angiogenesis via direct interaction with vascular endothelial growth factor (VEGF). Here we report that MMP9 can cleave HSPB1 and release anti-angiogenic fragments, which play a key role in tumorprogression. We mapped the cleavage sites and explored their physiological relevance during these processing events. HSPB1 cleavage by MMP9 inhibited VEGF-induced ECs activation and the C-terminal HSPB1 fragment exhibited more interaction with VEGF than did full-length HSPB1. HSPB1 cleavage occurs during B16F10 lung progression in wild-type mice. Also, intact HSPB1 was more detected on tumor endothelium of MMP9 null mice than wild type mice. Finally, we confirmed that secretion of C-terminal HSPB1 fragment was significantly inhibited lung and liver tumor progression of B16F10 melanoma cells and lung tumor progression of CT26 colon carcinoma cells, compared to full-length HSPB1. These data suggest that in vivo MMP9-mediated processing of HSPB1 acts to regulate VEGF-induced ECs activation for tumor progression, releasing anti-angiogenic HSPB1 fragments. Moreover, these findings potentially explain an anti-target effect for the failure of MMP inhibitors in clinical trials, suggesting that MMP inhibitors may have pro-tumorigenic effects by reducing HSPB1 fragmentation.
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- 2014
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33. Protective roles of methionine-R-sulfoxide reductase against stresses in Schizosaccharomyces pombe.
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Jo H, Cho YW, Ji SY, Kang GY, and Lim CJ
- Subjects
- Amino Acid Sequence, Base Sequence, Glutathione metabolism, Methionine Sulfoxide Reductases genetics, Molecular Sequence Data, Reactive Oxygen Species metabolism, Schizosaccharomyces genetics, Schizosaccharomyces growth & development, Stress, Physiological, Methionine Sulfoxide Reductases metabolism, Schizosaccharomyces physiology
- Abstract
The Schizosaccharomyces pombe msrB(+) gene encoding methionine-R-sulfoxide reductase (MsrB) was cloned into the shuttle vector pRS316 to generate the recombinant plasmid pFMetSO. The msrB(+) mRNA level was significantly increased in the S. pombe cells harboring pFMetSO, indicating that the cloned msrB(+) gene is functioning. In the presence of 0.1 mM L-methionine-(R,S)-sulfoxide, the S. pombe cells harboring pFMetSO could grow normally but the growth of the vector control cells was almost arrested. The S. pombe cells harboring pFMetSO exhibited the enhanced growth on the minimal medium plates with stress-inducing agents, such as hydrogen peroxide, superoxide radical-generating menadione (MD), nitric oxide (NO)-generating sodium nitroprusside (SNP), and cadmium (Cd), when compared with the vector control cells. They also gave rise to the enhanced growth at the high incubation temperature of 37 °C than the vector control cells. The S. pombe cells harboring pFMetSO contained lower reactive oxygen species (ROS) and higher total glutathione (GSH) levels than the vector control cells. In brief, the S. pombe MsrB plays a protective role against oxidative, nitrosative, and thermal stresses, and is involved in diminishing intracellular ROS level., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
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34. Inhibition of Snail1-DNA-PKcs protein-protein interface sensitizes cancer cells and inhibits tumor metastasis.
- Author
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Kang GY, Pyun BJ, Seo HR, Jin YB, Lee HJ, Lee YJ, and Lee YS
- Subjects
- Animals, Cell Line, Tumor, DNA-Activated Protein Kinase genetics, DNA-Binding Proteins genetics, Gene Expression Regulation, Neoplastic drug effects, Gene Expression Regulation, Neoplastic genetics, Humans, Mice, Neoplasm Metastasis, Neoplasm Proteins genetics, Neoplasms genetics, Neoplasms metabolism, Neoplasms pathology, Nuclear Proteins genetics, Protein Stability drug effects, Snail Family Transcription Factors, Transcription Factors genetics, Tumor Suppressor Protein p53 biosynthesis, Tumor Suppressor Protein p53 genetics, DNA-Activated Protein Kinase biosynthesis, DNA-Binding Proteins biosynthesis, Neoplasm Proteins biosynthesis, Neoplasms drug therapy, Nuclear Proteins biosynthesis, Peptides pharmacology, Transcription Factors biosynthesis
- Abstract
Our previous study suggested that the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) interacts with Snail1, which affects genomic instability, sensitivity to DNA-damaging agents, and migration of tumor cells by reciprocal regulation between DNA-PKcs and Snail1. Here, we further investigate that a peptide containing 7-amino acid sequences (amino acids 15-21) of Snail1 (KPNYSEL, SP) inhibits the endogenous interaction between DNA-PKcs and Snail1 through primary interaction with DNA-PKcs. SP restored the inhibited DNA-PKcs repair activity and downstream pathways. On the other hand, DNA-PKcs-mediated phosphorylation of Snail1 was inhibited by SP, which resulted in decreased Snail1 stability and Snail1 functions. However, these phenomena were only shown in p53 wild-type cells, not in p53-defective cells. From these results, it is suggested that interfering with the protein interaction between DNA-PKcs and Snail1 might be an effective strategy for sensitizing cancer cells and inhibiting tumor migration, especially in both Snail1-overexpressing and DNA-PKcs-overexpressing cancer cells with functional p53.
- Published
- 2013
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35. Thyroxine and triiodothyronine content in commercially available thyroid health supplements.
- Author
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Kang GY, Parks JR, Fileta B, Chang A, Abdel-Rahim MM, Burch HB, and Bernet VJ
- Subjects
- Animals, Chromatography, High Pressure Liquid, Dietary Supplements adverse effects, Dietary Supplements economics, Dietary Supplements standards, Electrochemical Techniques, Food Labeling, Humans, Internet economics, Maryland epidemiology, Patient Education as Topic, Risk, Thyroid (USP) chemistry, Thyroid Diseases diet therapy, Thyroid Gland chemistry, Thyrotoxicosis chemically induced, Thyrotoxicosis epidemiology, Thyrotoxicosis etiology, Thyroxine adverse effects, Thyroxine poisoning, Triiodothyronine adverse effects, Triiodothyronine poisoning, United States epidemiology, Consumer Product Safety, Dietary Supplements analysis, Food Contamination, Thyroid Diseases prevention & control, Thyroxine analysis, Triiodothyronine analysis
- Abstract
Background: As defined by the Dietary Supplement Health and Education Act 1997, such substances as herbs and dietary supplements fall under general Food and Drug Administration supervision but have not been closely regulated to date. We examined the thyroid hormone content in readily available dietary health supplements marketed for "thyroid support.", Methods: Ten commercially available thyroid dietary supplements were purchased. Thyroid supplements were dissolved in 10 mL of acetonitrile and water with 0.1% trifloroacetic acid and analyzed using high-performance liquid chromatography for the presence of both thyroxine (T4) and triiodothyronine (T3) using levothyroxine and liothyronine as a positive controls and standards., Results: The amount of T4 and T3 was measured separately for each supplement sample. Nine out of 10 supplements revealed a detectable amount of T3 (1.3-25.4 μg/tablet) and 5 of 10 contained T4 (5.77-22.9 μg/tablet). Taken at the recommended dose, 5 supplements delivered T3 quantities of greater than 10 μg/day, and 4 delivered T4 quantities ranging from 8.57 to 91.6 μg/day., Conclusions: The majority of dietary thyroid supplements studied contained clinically relevant amounts of T4 and T3, some of which exceeded common treatment doses for hypothyroidism. These amounts of thyroid hormone, found in easily accessible dietary supplements, potentially expose patients to the risk of alterations in thyroid levels even to the point of developing iatrogenic thyrotoxicosis. The current study results emphasize the importance of patient and provider education regarding the use of dietary supplements and highlight the need for greater regulation of these products, which hold potential danger to public health.
- Published
- 2013
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36. AMP-activated protein kinase phosphorylates CtBP1 and down-regulates its activity.
- Author
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Kim JH, Choi SY, Kang BH, Lee SM, Park HS, Kang GY, Bang JY, Cho EJ, and Youn HD
- Subjects
- AMP-Activated Protein Kinases biosynthesis, Alcohol Oxidoreductases genetics, DNA-Binding Proteins genetics, Enzyme Activation, HEK293 Cells, Humans, Phosphorylation, Serine genetics, Serine metabolism, Transcription, Genetic, Ubiquitination, AMP-Activated Protein Kinases metabolism, Alcohol Oxidoreductases metabolism, DNA-Binding Proteins metabolism, Gene Expression Regulation, bcl-2-Associated X Protein genetics
- Abstract
CtBP is a transcriptional repressor which plays a significant role in the regulation of cell proliferation and tumor progression. It was reported that glucose withdrawal causes induction of Bax due to the dissociation of CtBP from the Bax promoter. However, the precise mechanism involved in the regulation of CtBP still remains unclear. In this study, we found that an activated AMP-activated protein kinase (AMPK) phosphorylates CtBP1 on Ser-158 upon metabolic stresses. Moreover, AMPK-mediated phosphorylation of CtBP1 (S158) attenuates the repressive function of CtBP1. We also confirmed that triggering activation of AMPK by various factors resulted in an increase of Bax gene expression. These findings provide connections of AMPK with CtBP1-mediated regulation of Bax expression for cell death under metabolic stresses., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2013
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37. Analysis of the biochemical role of Lys-11 in polyubiquitin chain formation using quantitative mass spectrometry.
- Author
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Jung JW, Bae SJ, Kang GY, Kim KH, Yeo WS, Park SH, Seol JH, Yi EC, and Kim KP
- Subjects
- Cell Cycle Proteins chemistry, Cell Cycle Proteins metabolism, Chromatography, High Pressure Liquid methods, Neoplasm Proteins chemistry, Neoplasm Proteins metabolism, Recombinant Proteins chemistry, Recombinant Proteins metabolism, Lysine chemistry, Lysine metabolism, Polyubiquitin chemistry, Polyubiquitin metabolism, Tandem Mass Spectrometry methods, Ubiquitination physiology
- Abstract
Rationale: Protein ubiquitination plays a critical role in regulating many cellular events, such as protein localization and stability, cellular signal transduction and DNA repair. Recent studies have shown that polyubiquitin (polyUb) chains elongate through heterogeneous isopeptide linkages to K11, K29, K48 and K63. In this study we have investigated the usage of isopeptide linkages of polyUb chains in different molecular weight regions by using quantitative mass spectrometry., Methods: Recombinant Chfr protein was autoubiquitinated by E1 enzyme, E2 enzyme UbcH5 and ubiquitin (WT Ub, K11R Ub, K48R Ub and K63R Ub) in vitro, and different molecular weight regions of ubiquitinated Chfr were then subjected to liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) following sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) and in-gel digestion., Results: Absolute QUantitative Analysis (AQUA) of polyUb chain formation with wild-type (WT) and point mutants of ubiquitin was performed, and the results suggested that the K11 polyUb chain was most frequently used in the high ubiquitin conjugates of WT Ub. Furthermore, the extent of polyUb chain formation with K11R Ub was decreased about 10-fold compared to polyUb chain formation with WT Ub through the entire molecular weight region. The present study suggests that the linkage through K11 plays crucial roles in polyUb chain formation., Conclusions: Topologies of polyUb chains in the low and high Ub conjugates were studied using mass spectrometry. K48 and K63 were the primary ubiquitination sites of the low molecular weight Ub conjugates, whereas K11 was the critical site of polyUb chain formation in high molecular weight Ub conjugates., (Copyright © 2012 John Wiley & Sons, Ltd.)
- Published
- 2013
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38. Dementia due to Meningovascular Syphilis in Medial Temporal Lobe and Cognitive Rehabilitation.
- Author
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Ahn S, Jung KI, Yoo WK, Kang GY, and Ohn SH
- Abstract
The temporal lobe is essential in saving declarative memory and plays an important role along with the cerebral neocortex in creating and maintaining long-term memory. Damage to the temporal lobe is expected to result in cognitive impairment or dementia, which has characteristic symptoms such as cognitive and behavioral dysfunction and decreasing self-reliance in activities of daily living. We report on a patient, who suffered from dementia due to meningovascular syphilis affecting the medial temporal lobe, and on the outcome of cognitive rehabilitation.
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- 2012
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39. Effects on micronuclei formation of 60-Hz electromagnetic field exposure with ionizing radiation, hydrogen peroxide, or c-Myc overexpression.
- Author
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Jin YB, Kang GY, Lee JS, Choi JI, Lee JW, Hong SC, Myung SH, and Lee YS
- Subjects
- Animals, Dose-Response Relationship, Drug, Dose-Response Relationship, Radiation, Fibroblasts drug effects, Fibroblasts metabolism, Fibroblasts radiation effects, Humans, Mice, Micronucleus Tests, NIH 3T3 Cells, Electromagnetic Fields adverse effects, Hydrogen Peroxide pharmacology, Proto-Oncogene Proteins c-myc genetics, Transcriptional Activation
- Abstract
Purpose: Epidemiological studies have demonstrated a possible correlation between exposure to extremely low-frequency magnetic fields (ELF-MF) and cancer. However, this correlation has yet to be definitively confirmed by epidemiological studies. The principal objective of this study was to assess the effects of 60 Hz magnetic fields in a normal cell line system, and particularly in combination with various external factors, via micronucleus (MN) assays., Materials and Methods: Mouse embryonic fibroblast NIH3T3 cells and human lung fibroblast WI-38 cells were exposed for 4 h to a 60 Hz, 1 mT uniform magnetic field with or without ionizing radiation (IR, 2 Gy), H(2)O(2) (100 μM) and cellular myelocytomatosis oncogene (c-Myc) activation., Results: The results obtained showed no significant differences between the cells exposed to ELF-MF alone and the unexposed cells. Moreover, no synergistic effects were observed when ELF-MF was combined with IR, H(2)O(2), and c-Myc activation., Conclusions: Our results demonstrate that ELF-MF did not enhance MN frequency by IR, H(2)O(2) and c-Myc activation.
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- 2012
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40. Direct and indirect contribution of human embryonic stem cell-derived hepatocyte-like cells to liver repair in mice.
- Author
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Woo DH, Kim SK, Lim HJ, Heo J, Park HS, Kang GY, Kim SE, You HJ, Hoeppner DJ, Kim Y, Kwon H, Choi TH, Lee JH, Hong SH, Song KW, Ahn EK, Chenoweth JG, Tesar PJ, McKay RD, and Kim JH
- Subjects
- Animals, Biomarkers metabolism, Carbon Tetrachloride, Cell Separation methods, Cells, Cultured, Chemical and Drug Induced Liver Injury metabolism, Chemical and Drug Induced Liver Injury pathology, Coculture Techniques, Disease Models, Animal, Embryonic Stem Cells drug effects, Embryonic Stem Cells metabolism, Hepatocytes drug effects, Hepatocytes metabolism, Hepatocytes pathology, Humans, Immunohistochemistry, Induced Pluripotent Stem Cells drug effects, Induced Pluripotent Stem Cells metabolism, Laser Capture Microdissection, Lithium Chloride pharmacology, Liver blood supply, Liver metabolism, Mass Spectrometry, Mice, Mice, Inbred BALB C, Mice, Nude, Microscopy, Electron, Neovascularization, Physiologic, Polymerase Chain Reaction, Proteomics methods, Time Factors, Wound Healing, Cell Differentiation drug effects, Cell Proliferation, Chemical and Drug Induced Liver Injury surgery, Embryonic Stem Cells transplantation, Hepatocytes transplantation, Induced Pluripotent Stem Cells transplantation, Liver pathology, Liver Regeneration
- Abstract
Background & Aims: Many studies of embryonic stem cells have investigated direct cell replacement of damaged tissues, but little is known about how donor cell-derived signals affect host tissue regeneration. We investigated the direct and indirect roles of human embryonic stem cell-derived cells in liver repair in mice., Methods: To promote the initial differentiation of human embryonic stem cells into mesendoderm, we activated the β-catenin signaling pathway with lithium; cells were then further differentiated into hepatocyte-like cells. The differentiated cells were purified by indocyanine green staining and laser microdissection and characterized by immunostaining, polymerase chain reaction, biochemical function, electron microscopy, and transplantation analyses. To investigate indirect effects of these cells, secreted proteins (secretomes) were analyzed by a label-free quantitative mass spectrometry. Carbon tetrachloride was used to induce acute liver injury in mice; cells or secreted proteins were administered by intrasplenic or intraperitoneal injection, respectively., Results: The differentiated hepatocyte-like cells had multiple features of normal hepatocytes, engrafted efficiently into mice, and continued to have hepatic features; they promoted proliferation of host hepatocytes and revascularization of injured host liver tissues. Proteomic analysis identified proteins secreted from these cells that might promote host tissue repair. Injection of the secreted proteins into injured livers of mice promoted significant amounts of tissue regeneration without cell grafts., Conclusions: Hepatocyte-like cells derived from human embryonic stem cells contribute to recovery of injured liver tissues in mice, not only by cell replacement but also by delivering trophic factors that support endogenous liver regeneration., (Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.)
- Published
- 2012
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41. Asymmetric Rh(I)-catalyzed intramolecular [3 + 2] cycloaddition of 1-yne-vinylcyclopropanes for bicyclo[3.3.0] compounds with a chiral quaternary carbon stereocenter and density functional theory study of the origins of enantioselectivity.
- Author
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Lin M, Kang GY, Guo YA, and Yu ZX
- Subjects
- Catalysis, Models, Molecular, Molecular Conformation, Stereoisomerism, Substrate Specificity, Bridged Bicyclo Compounds chemistry, Carbon chemistry, Cyclopropanes chemistry, Quantum Theory, Rhodium chemistry
- Abstract
A highly enantioselective Rh(I)-catalyzed intramolecular [3 + 2] cycloaddition of 1-yne-VCPs to bicyclo[3.3.0] compounds with an all-carbon chiral quaternary stereocenter at the bridgehead carbon was developed. DFT calculations of the energy surface of the catalytic cycle (complexation, cyclopropane cleavage, alkyne insertion, and reductive elimination) of the asymmetric [3 + 2] cycloaddition reaction indicated that the rate- and stereo-determining step is the alkyne-insertion step. Analysis of the alkyne-insertion transition states revealed that the serious steric repulsion between the substituents in the alkyne moiety of the substrates and the rigid H(8)-BINAP backbone is responsible for not generating the disfavored [3 + 2] cycloadducts., (© 2011 American Chemical Society)
- Published
- 2012
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42. Diarylheptanoids from the seeds of Alpinia katsumadai as heat shock factor 1 inducers.
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Nam JW, Kang GY, Han AR, Lee D, Lee YS, and Seo EK
- Subjects
- DNA-Binding Proteins drug effects, Diarylheptanoids chemistry, Heat Shock Transcription Factors, Molecular Structure, Republic of Korea, Seeds chemistry, Transcription Factors drug effects, Alpinia chemistry, Diarylheptanoids isolation & purification, Diarylheptanoids pharmacology, HSP70 Heat-Shock Proteins drug effects
- Abstract
Seven new diarylheptanoids, (-)-(R)-4″-hydroxyyashabushiketol (1), (3S,5S)-alpinikatin (2), katsumain C (3), 7-epi-katsumain C (4), ent-alpinnanin B (5), ent-alpinnanin A (6), and ent-calyxin H (8), were isolated from the EtOAc extract of the seeds of Alpinia katsumadai together with three known compounds, alpinnanin B (7), epicalyxin H (9), and calyxin H (10). Each isomer mixture of 3 and 4, 5-7, and 8-10 was separated successfully by preparative HPLC using a chiral column. The three isomer mixtures (3 and 4, 5-7, 8-10) at 1 μM increased expression of heat shock factor 1 (HSF1) with fold increases of 1.438, 1.190, and 1.316, respectively, which was accompanied with increased expression of heat shock protein (HSP) 27 (1.403-, 1.250-, and 1.270-fold, respectively) and HSP70 (1.373-, 1.313-, and 1.229-fold, respectively) without cellular cytotoxicity, suggesting a possible application of these compounds as HSP inducers. Celastrol was used as a positive control of HSP induction, producing fold increases of 1.066 (HSF1), 1.216 (HSP27), and 1.371 (HSP70) at 1 μM. Compounds 1 and 2 did not affect the induction of HSF1 protein.
- Published
- 2011
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43. Precursor miR-886, a novel noncoding RNA repressed in cancer, associates with PKR and modulates its activity.
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Lee K, Kunkeaw N, Jeon SH, Lee I, Johnson BH, Kang GY, Bang JY, Park HS, Leelayuwat C, and Lee YS
- Subjects
- Humans, NF-kappa B genetics, NF-kappa B metabolism, Neoplasms metabolism, Phosphorylation, RNA, Double-Stranded genetics, RNA, Double-Stranded metabolism, Transfection, eIF-2 Kinase genetics, MicroRNAs metabolism, Neoplasms genetics, RNA Precursors metabolism, eIF-2 Kinase metabolism
- Abstract
Noncoding RNAs have drawn significant attention in biology recently. Whereas the current research is highly inclined to microRNAs, research on other noncoding RNAs has lagged behind. Here, we investigated a novel noncoding RNA that has been known as precursor microRNA miR-886 (pre-miR-886). Pre-miR-886 has been proposed also as a vault RNA, a component of the vault complex implicated in cancer drug resistance. We identified pre-miR-886 as a 102-nucleotide-long, abundant cytoplasmic RNA that is neither a genuine pre-microRNA nor a vault RNA. Pre-miR-886 is physically associated with PKR (Protein Kinase RNA-activated), an interferon-inducible and double-stranded RNA dependent kinase. The suppression of pre-miR-886 activates PKR and its downstream pathways, eIF2α phosphorylation and the NF-κB pathway, leading to impaired cell proliferation. We also found that pre-miR-886 is suppressed in a wide-range of cancer cell lines and in clinical specimens. This study is the first intense characterization of pre-miR-886 as well as the initial report on its function as a PKR regulator, which suggests a critical role in tumorigenesis.
- Published
- 2011
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44. Biomarker discovery and proteomic evaluation of cadmium toxicity on a collembolan species, Paronychiurus kimi (Lee).
- Author
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Son J, Lee SE, Park BS, Jung J, Park HS, Bang JY, Kang GY, and Cho K
- Subjects
- Analysis of Variance, Animals, Arthropods physiology, Biomarkers analysis, Biomarkers chemistry, Chromatography, Liquid, Electrophoresis, Gel, Two-Dimensional, Electrophoresis, Polyacrylamide Gel, Insect Proteins analysis, Insect Proteins classification, Insect Proteins metabolism, Proteome chemistry, Receptors, Cell Surface, Tandem Mass Spectrometry, Arthropods drug effects, Cadmium toxicity, Insect Proteins chemistry, Proteome drug effects, Proteomics methods
- Abstract
The goal of this study was to identify promising new biomarkers of cadmium by identifying differentially expressed proteins in Paronychiurus kimi after exposure to cadmium. Through proteomic analysis of P. kimi using 1-D PAGE and nano-LC-MS/MS, 36 downregulated proteins and 40 upregulated proteins were found. Some of the downregulated and upregulated proteins were verified by LC-MS/MS analysis after 2-D PAGE. Downregulated proteins in response to cadmium exposure were involved in glycolysis and energy metabolism, chaperones, transcription, reproduction, and neuron growth. In contrast, proteins involved in glycolysis and energy production, neurogenesis, defense systems response to bacteria, and protein biosynthesis were upregulated in cadmium-treated collembolans. Cubulin may be a potential biomarker for the detection of cadmium in P. kimi since this biomarker was able to low levels (3.5 mg/kg) of cadmium. The 14-3-3 ζ was also found to be a potential biomarker for the detection of medium levels (14 mg/kg) of cadmium. Collembolans may be an alternative tool to humans because many collembolans proteins show a high homology to human proteins., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2011
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45. Cross-sectional prevalence of metabolic syndrome in Korean patients with schizophrenia.
- Author
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Kang SH, Kim KH, Kang GY, Lee KH, Kim KK, Soh M, Ahn KJ, Kim SH, and Lee JI
- Subjects
- Adult, Aged, Antipsychotic Agents, Cross-Sectional Studies, Female, Humans, Male, Metabolic Diseases diagnosis, Middle Aged, Prevalence, Republic of Korea epidemiology, Retrospective Studies, Schizophrenia drug therapy, Young Adult, Metabolic Diseases epidemiology, Schizophrenia epidemiology
- Published
- 2011
- Full Text
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46. Bcl-XL and STAT3 mediate malignant actions of gamma-irradiation in lung cancer cells.
- Author
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Ho JN, Kang GY, Lee SS, Kim J, Bae IH, Hwang SG, and Um HD
- Subjects
- Cell Line, Tumor, Epithelial Cells pathology, Humans, Mesoderm pathology, Neoplasm Invasiveness, Gamma Rays adverse effects, Lung Neoplasms pathology, STAT3 Transcription Factor physiology, bcl-X Protein physiology
- Abstract
Previous reports suggest that, in addition to its therapeutic effects, ionizing radiation (IR) increases the invasiveness of surviving cancer cells. Here, we demonstrate that this activity of IR in lung cancer cells is mediated by a signaling pathway involving p38 kinase, phosphoinositide 3-kinase, Akt, and matrix metalloproteinase (MMP-2). The invasion-promoting doses of IR also increased and reduced the levels of vimentin and E-cadherin, respectively, both of which are markers for the epithelial-mesenchymal transition (EMT). Interestingly, all of these malignant actions of IR were mimicked by the overexpression of Bcl-X(L), a pro-survival member of the Bcl-2 family, in lung cancer cells. Moreover, both RNA and protein levels of Bcl-X(L) were elevated upon irradiation of the cells, and the prevention of this event using small-interfering RNAs of Bcl-X(L) reduced the ability of IR to promote invasion signals and EMT-associated events. This suggests that Bcl-X(L) functions as a signaling mediator of the malignant effects of IR. It was also demonstrated that IR enhances signal transducer and activator of transcription 3 (STAT3) phosphorylation, and the reduction of STAT3 levels via RNA interference prevented IR-induced Bcl-X(L) accumulation, and thus all the tested Bcl-X(L)-dependent events. Overall, the data suggest that IR induces Bcl-X(L) accumulation via STAT3, which then promotes cancer cell invasion and EMT-associated markers. Our findings demonstrate a novel function of Bcl-X(L) in cancer, and also advance our understanding of the malignant actions of IR significantly.
- Published
- 2010
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47. Phospholipase A2 activity of peroxiredoxin 6 promotes invasion and metastasis of lung cancer cells.
- Author
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Ho JN, Lee SB, Lee SS, Yoon SH, Kang GY, Hwang SG, and Um HD
- Subjects
- Animals, Arachidonic Acid metabolism, Body Weight, Cell Line, Tumor, Cell Proliferation, Humans, Mice, Mice, Inbred BALB C, Neoplasm Invasiveness, Neoplasm Metastasis, Organ Size, Transfection, Lung Neoplasms enzymology, Lung Neoplasms pathology, Peroxiredoxin VI metabolism, Phospholipases A2 metabolism
- Abstract
Peroxiredoxins (PRDX) are a family of thiol-dependent peroxidases. Among the six mammalian members of this family, PRDX6 is the only protein that additionally exhibits phospholipase A(2) (PLA(2)) activity. The physiologic role of this interesting PRDX6 feature is largely unknown at present. In this study, we show that PRDX6 increases the metastatic potential of lung cancer cells. Functional analyses of the enzymatic activities of PRDX6, using specific pharmacologic inhibitors and mutagenesis studies, reveal that both peroxidase and PLA(2) activities are required for metastasis. Specifically, peroxidase activity facilitates the growth of cancer cells, and PLA(2) activity promotes invasiveness. Further investigation of the latter event discloses that PLA(2) activity promotes accumulation of arachidonic acid, which, in turn, induces the invasive pathway involving p38 kinase, phosphoinositide 3-kinase, Akt, and urokinase-type plasminogen activator. This study is the first to define the functions of the enzymatic activities of PRDX6 in metastasis and to show the involvement of arachidonic acid in PRDX6 action in intact cells. These novel findings provide a significant step toward elucidating the role of PRDX6 in cancer and the mechanism of its action. Mol Cancer Ther; 9(4); 825-32. (c)2010 AACR.
- Published
- 2010
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48. Peroxiredoxin 6 promotes lung cancer cell invasion by inducing urokinase-type plasminogen activator via p38 kinase, phosphoinositide 3-kinase, and Akt.
- Author
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Lee SB, Ho JN, Yoon SH, Kang GY, Hwang SG, and Um HD
- Subjects
- Cell Growth Processes physiology, Cell Line, Tumor, Gene Expression Regulation, Neoplastic physiology, Humans, Lung Neoplasms genetics, Neoplasm Invasiveness genetics, Neoplasm Invasiveness pathology, Oxidative Stress genetics, Peroxiredoxin VI genetics, Proto-Oncogene Proteins c-akt metabolism, RNA, Small Interfering genetics, Signal Transduction genetics, Transgenes genetics, Urokinase-Type Plasminogen Activator genetics, p38 Mitogen-Activated Protein Kinases metabolism, Lung Neoplasms metabolism, Lung Neoplasms pathology, Peroxiredoxin VI metabolism, Phosphatidylinositol 3-Kinases metabolism, Urokinase-Type Plasminogen Activator biosynthesis
- Abstract
The peroxiredoxin family of peroxidase has six mammalian members (Prx 1-6). Considering their frequent up-regulation in cancer cells, Prxs may contribute to cancer cells' survival in face of oxidative stress. Here, we show that Prx 6 promotes the invasiveness of lung cancer cells, accompanied by an increase in the activity of phosphoinositide 3-kinase (PI3K), the phosphorylation of p38 kinase and Akt, and the protein levels of uPA. Functional studies reveal that these components support Prx 6-induced invasion in the sequence p38 kinase/PI3K, Akt, and uPA. The findings provide a new understanding of the action of Prx 6 in cancer.
- Published
- 2009
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49. Dramatic clearance of a recalcitrant acral viral wart using methyl aminolevulinate-red light photodynamic therapy.
- Author
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Chong WS and Kang GY
- Subjects
- Adult, Humans, Male, Aminolevulinic Acid administration & dosage, Light, Photochemotherapy, Photosensitizing Agents administration & dosage, Warts drug therapy
- Abstract
A 20-year-old man presented with a 3-month history of a viral wart located on his right thumb. Cryotherapy was administered weekly to the wart over 5 months without any significant improvement. A decision was made to treat the wart with red light photodynamic therapy (PDT) using topical methyl aminolevulinate (MAL) administered as three treatments 1-week apart. The patient was reviewed 4 weeks after the third treatment and the wart was found to have cleared completely. Three months after the last treatment, there remained no clinical evidence of recurrence of the wart. Pain was the main problem with the treatment but it was tolerable. Although the successful treatment of recalcitrant acral viral warts with PDT using 5-aminolevulinic acid (ALA) is well documented, this is the first report of the successful PDT treatment of a recalcitrant acral viral wart using the methylester derivative of ALA. We believe that MAL is a valuable alternative photosensitizer to ALA as it is more lipophilic, has better penetration and causes less pain.
- Published
- 2009
- Full Text
- View/download PDF
50. A binary matrix for improved detection of phosphopeptides in matrix-assisted laser desorption/ionization mass spectrometry.
- Author
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Zhou LH, Kang GY, and Kim KP
- Subjects
- Amino Acid Sequence, Animals, Caseins isolation & purification, Caseins metabolism, Cattle, Crystallization, Gentisates chemistry, Milk chemistry, Molecular Sequence Data, Phosphopeptides isolation & purification, Phosphopeptides metabolism, Sensitivity and Specificity, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization economics, Trypsin metabolism, Caseins analysis, Coumaric Acids chemistry, Phosphopeptides analysis, Picolinic Acids chemistry, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
Application of matrix-assisted laser-desorption/ionization mass spectrometry (MALDI MS) to analysis and characterization of phosphopeptides in peptide mixtures may have a limitation, because of the lower ionizing efficiency of phosphopeptides than nonphosphorylated peptides in MALDI MS. In this work, a binary matrix that consists of two conventional matrices of 3-hydroxypicolinic acid (3-HPA) and alpha-cyano-4-hydroxycinnamic acid (CCA) was tested for phosphopeptide analysis. 3-HPA and CCA were found to be hot matrices, and 3-HPA not as good as CCA and 2,5-dihydroxybenzoic acid (DHB) for peptide analysis. However, the presence of 3-HPA in the CCA solution with a volume ratio of 1:1 could significantly enhance ion signals for phosphopeptides in both positive-ion and negative-ion detection modes compared with the use of pure CCA or DHB, the most common phosphopeptide matrices. Higher signal intensities of phosphopeptides could be obtained with lower laser power using the binary matrix. Neutral loss of the phosphate group (-80 Da) and phosphoric acid (-98 Da) from the phosphorylated-residue-containing peptide ions with the binary matrix was decreased compared with CCA alone. In addition, since the crystal shape prepared with the binary matrix was more homogeneous than that prepared with DHB, searching for 'sweet' spots can be avoided. The sensitivity to detect singly or doubly phosphorylated peptides in peptide mixtures was higher than that obtained with pure CCA and as good as that obtained using DHB. We also used the binary matrix to detect the in-solution tryptic digest of the crude casein extracted from commercially available low fat milk sample, and found six phosphopeptides to match the digestion products of casein, based on mass-to-charge values and LIFT TOF-TOF spectra., (Copyright (c) 2009 John Wiley & Sons, Ltd.)
- Published
- 2009
- Full Text
- View/download PDF
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