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Ogunmuyiwa J, Niño I, Kang T, Shechtman KR, Balogun OD, Ashamalla H. Increasing Accrual of Racial and Ethnic Minorities in Breast Cancer Clinical Trials by Partnering with Community Hospitals. Int J Radiat Oncol Biol Phys 2023; 117:e45. [PMID: 37785448 DOI: 10.1016/j.ijrobp.2023.06.746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Clinical trials provide the highest level of evidence in evaluating the safety and efficacy of new radiation approaches for breast cancer. However, there is a significant lack of racial and ethnic diversity among participants who are enrolled. This discrepancy in research inclusion leads to limitations in applying clinical data, therapeutic indices, technique safety, and toxicity to a diverse patient population. A community-based approach, such as the inclusion of community hospitals in trial enrollment, has been shown to boost participation within these underserved populations. The aim of this study was to evaluate the rate of enrollment of racial and ethnic minorities in breast cancer clinical trials with the inclusion of community hospitals within an NYC hospital system. MATERIALS/METHODS Trial enrollment of breast cancer patients at 3 hospitals was retrospectively assessed. Patient demographics, including age, race, and ethnicity, were compared by enrollment setting. Eligible trials included prospective, randomized clinical trials assessing breast cancer irradiation. Participating hospitals included an academic hospital in Manhattan (MH), and 2 community hospitals in Brooklyn (BH) and Queens (QH). Collectively, these hospitals have a catchment area of 6.2 million, of which 35.2% are White, 19.7% are Asian, 18.3% are Black/African American (B/AA), and 21.2% are Hispanic/Latino (H/L). There is a wide demographic variety within this catchment area. BH serves neighborhoods with a B/AA population as high as 85% and QH serves neighborhoods with an Asian population as high as 54%. RESULTS From January to December 2022, 146 patients were enrolled in 4 breast cancer trials opened at MH (59.6%, n = 87), BH (28.8%, n = 42), and QH (11.6%, n = 17). The average age was 63.3 (SD = 12.1). Of all patients enrolled, 52.7% identified as White, 23.2% as B/AA, 13% as Asian, and 8.9% as H/L. Of the patients enrolled at MH, 64.4% identified as White, 12.6% as B/AA, 8% as Asian, and 8% as H/L. At BH, 50% identified as B/AA, 38% as White, 4.7% as Asian, and 11.9% as H/L. At QH, 58.8% identified as Asian, 29.4% as White, and 11.8% as B/AA. B/AA (OR = 4.41, 95% CI, 1.94-10.03; p<.01) and Asian (OR = 2.92, 95% CI, 1.07-7.93; p<.05) patients were more likely to be enrolled at a community hospital when compared to an academic hospital. There was no difference in enrollment rates between campuses for H/L patients (OR = 1.29, 95% CI, 0.41-4.06; p = .66). CONCLUSION Enrollment of participants from underrepresented racial and ethnic populations in clinical trials is critical to ensuring health equity. These findings suggest partnerships with community hospitals located in underserved populations can be a strategy to improve diversity among clinical trial participants. As it is well-documented that community hospitals can deliver high quality research with similar trial metrics to larger, academic hospitals, partnerships with community hospitals are a feasible way to reduce disparities in breast cancer research.
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Affiliation(s)
- J Ogunmuyiwa
- New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY
| | - I Niño
- New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY
| | - T Kang
- New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY
| | - K R Shechtman
- New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY
| | - O D Balogun
- New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY; Department of Radiation Oncology, Weill Cornell Medicine, New York, NY
| | - H Ashamalla
- New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY
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Kim HJ, Lee HS, Kazmi SZ, Hann HJ, Kang T, Cha J, Choi S, Swan H, Kim H, Lee YS, Ahn HS. Familial risk for endometriosis and its interaction with smoking, age at menarche and body mass index: a population-based cohort study among siblings. BJOG 2021; 128:1938-1948. [PMID: 34028167 DOI: 10.1111/1471-0528.16769] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To quantify familial risk of endometriosis among full siblings and examine interactions between family history and smoking, age at menarche or body mass index (BMI). DESIGN, SETTING AND POPULATION Population-based nationwide cohort study. METHODS Using data from the Korean National Health Insurance and Screening Programme databases on kinship, healthcare utilisation, lifestyle and anthropometrics, we identified 2 109 288 women with full siblings and their environmental risk factors from 2002 to 2018. Familial risks were estimated using Cox proportional-hazards models, represented as incidence risk ratios (IRR) with 95% CI. Interaction between family history and smoking, age at menarche or BMI were assessed on an additive scale. MAIN OUTCOME MEASURES IRR of endometriosis among women with and without affected siblings. RESULTS From 19 195 women with affected siblings, 1126 developed endometriosis with an incidence of 35.45/10 000 person-years. Familial risk of endometriosis with versus without affected siblings was increased to IRR 2.75 (95% CI 2.25-3.36), and the highest risk was with affected twins (IRR 6.98; 95% CI 4.19-11.62). Women with both a family history and either smoking, early menarche or low BMI had a significantly higher risk of endometriosis compared with the general population and can be regarded as a high-risk group, the IRRs were 4.28 (95% CI 2.43-7.55), 3.47 (95% CI 2.82-4.26) and 3.09 (95% CI 2.68-3.56), respectively. Substantial effect modification of the associations was noted by smoking and early menarche, as their combined risk with family history exceeded the sum of their individual risks, which was also statistically significant. CONCLUSION Genetic factors are the primary contributor to the familial aggregation of endometriosis. Significant gene-environment interaction exists between family history and smoking or early menarche.
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Affiliation(s)
- H J Kim
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea
| | - H-S Lee
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea
| | - S Z Kazmi
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea
| | - H J Hann
- Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Korea
| | - T Kang
- Health and Wellness College, Sungshin Women's University, Seoul, Korea
| | - J Cha
- Department of Public Health, Korea University, Seoul, Korea
| | - S Choi
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea
| | - H Swan
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea
| | - H Kim
- Department of Obstetrics and Gynaecology, Seoul National University Hospital, Seoul, Korea
| | - Y S Lee
- Department of Health Informatics and Management, College of Medicine, Chungbuk National University, Cheongju, Korea
| | - H S Ahn
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea
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Jung KH, Kim HJ, Park W, Lim MJ, Kang T, Kang MJ, Kim KB, Ahn HS. Incidence, survival, and risk of cardiovascular events in adult inflammatory myopathies in South Korea: a nationwide population-based study. Scand J Rheumatol 2020; 49:323-331. [PMID: 32286141 DOI: 10.1080/03009742.2019.1707281] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Epidemiological studies on inflammatory myopathies (IMs) show widely variable results, and studies on Asians are lacking. Despite emerging interest in the cardiovascular disease (CVD) risk associated with IMs, the prevalence of CVD in IM patients and its impact on mortality remain unclear. We conducted a nationwide, population-based study on the incidence, mortality, and associated major CVD events of IMs in the Republic of Korea over 11 years. METHOD Using the nationwide, population-based National Health Insurance claims database and the Rare Intractable Disease registration programme, we estimated incidence, mortality, and CVD occurrence. Survival was examined using the Kaplan-Meier method. Mortality rate in IMs with CVD was analysed by Cox proportional hazards regression. RESULTS There were 3014 incident cases, 640 of whom died during the study period. The mean annual incidence was 7.16/106. Dermatomyositis (DM) and polymyositis (PM) had 5 year survival rates of 76.8% and 79.3%, respectively. Cardiovascular events occurred in 155 patients and 40.6% of IM patients with CVD died. Acute myocardial infarction in men had the highest risk of any CVD event in both DM [standardized incidence ratio (SIR) 4.2, 95% confidence interval (95% CI) 2.4-7.2] and PM (SIR 3.5, 95% CI 1.8-7.0). Haemorrhagic stroke had the highest hazard ratio (HR) in both DM (HR 2.31, 95% CI 1.13-4.70) and PM patients (HR 2.10, 95% CI 1.03-4.27) compared with the general population with CVD. CONCLUSION We found persistently low incidence, poor survival, and high major CVD incidence in IMs, and increased mortality in IMs with CVD.
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Affiliation(s)
- K H Jung
- Division of Rheumatology, Department of Internal Medicine, College of Medicine, Inha University , Incheon, Republic of Korea
| | - H J Kim
- Department of Preventive Medicine, College of Medicine, Korea University , Seoul, Republic of Korea
| | - W Park
- Division of Rheumatology, Department of Internal Medicine, College of Medicine, Inha University , Incheon, Republic of Korea
| | - M J Lim
- Division of Rheumatology, Department of Internal Medicine, College of Medicine, Inha University , Incheon, Republic of Korea
| | - T Kang
- Health Insurance Policy Research Institute, National Health Institute Service , Wonju, Republic of Korea
| | - M J Kang
- Department of Public Health, Graduate School, Korea University , Seoul, Republic of Korea
| | - K-B Kim
- Department of Public Health, Graduate School, Korea University , Seoul, Republic of Korea
| | - H S Ahn
- Department of Preventive Medicine, College of Medicine, Korea University , Seoul, Republic of Korea
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Lee D, Bae H, Ahn J, Kang T, Seo DG, Hwang DS. Catechol-thiol-based dental adhesive inspired by underwater mussel adhesion. Acta Biomater 2020; 103:92-101. [PMID: 31811956 DOI: 10.1016/j.actbio.2019.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/22/2019] [Accepted: 12/02/2019] [Indexed: 12/21/2022]
Abstract
The critical problem associated with the underwater mussel adhesive catechol-based 3,4-dihydroxy-L-phenylalanine (DOPA) is its sensitivity to oxidation. To overcome this problem, mussels underwent etching in the presence of acidic pH conditions (<3.0), and thiol chemistry was used to control the propensity of DOPA for oxidation. Similar strategies deployed by mussels are also actively utilized in dental adhesives which undergo etching in the presence of phosphoric acid derivatives to maximize the bonding strength and adapt thiol chemistries to minimize shrinkage stress. In view of the similarities between dental and underwater mussel adhesives, we employ in this study the strategy of mussel adhesion-the combination of DOPA and thiol chemistry with acid etching-to one of the most critical issues in dental adhesives, namely, the dentin bonding with zirconia. As a result, the adhesion bonding between zirconia and dentin, one of the most elusive problems in dentistry, has improved compared to the commercially available adhesive resin formulation. In addition, in view of the similar human oral and mussel adhesive environments, our findings will considerably contribute to the translation of the adhesive system inspired by mussels. STATEMENT OF SIGNIFICANCE: Mussels are effectively operated by creating an acidic environment when adhering with 3,4-dihydroxy-l-phenylalanine (DOPA)-thiol redox chemistry for underwater bonding. Similarly, in dental adhesives, phosphoric acid-based etching is used for dentin-bonding materials. In view of the similarity between dental adhesives and underwater mussel adhesives, the combination of DOPA and thiol chemistry with acid etching can be used to overcome one of the most critical issues in dentin medical adhesives. The proposed adhesion method produces high adhesion strengths compared to those currently used in dentin and zirconia adhesives. Here, we extend and evaluate dentin and zirconia dental adhesives by mixing with mussel (DOPA)-thiol redox chemistry and acid etching.
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Kang T, Qian S, Smith GS, Do C, Heller WT. Small-angle neutron scattering study of a dense microemulsion system formed with an ionic liquid. Soft Matter 2017; 13:7154-7160. [PMID: 28895963 DOI: 10.1039/c7sm01516j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mixtures of water, octane and 1-octanol with 1-tetradecyl-3-methylimidazolium chloride (C14MIM·Cl), often referred to as a surface active ionic liquid (SAIL), form water-in-oil microemulsions that have potential application as extraction media for various metal ions. Here, we present a structural study by small-angle neutron scattering (SANS) of dense microemulsions formed by surfactant-rich mixtures of these four compounds to understand how the SAIL can be used to tune the structures and properties of the microemulsions. The SANS experiments revealed that the microemulsions formed are composed of two phases, a water-in-oil microemulsion and a bicontinuous microemulsion, which becomes the dominant phase at high surfactant concentration. In this concentration regime, the surfactant film becomes more rigid, having a higher bending modulus that results from the parallel stacking of the imidazolium ring of the SAIL. At lower surfactant concentrations, the molecular packing of the SAIL does not change with the water content of the microemulsion. The results presented here correlate well with previously observed changes in the interaction between the IL cation and metal ions (Y. Tong, L. Han and Y. Yang, Ind. Eng. Chem. Res., 2012, 51, 16438-16443), while the capacity of the microemulsion system for water remains high enough for using the system as an extraction medium.
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Affiliation(s)
- T Kang
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Omer T, Mailhot T, Berona K, Swadron S, Kang T. 337 Accuracy of Landmark-Guided Glenohumeral Intra-Articular Injections in Patients With Anterior Shoulder Dislocations. Ann Emerg Med 2017. [DOI: 10.1016/j.annemergmed.2017.07.408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kang T, Berona K, Park E, Fredericks A, Chilstrom M, Mailhot T, Inaba K, Burner E. 355 Reliability of the Abdominal Exam in Blunt Trauma Patients With Altered Mental Status. Ann Emerg Med 2016. [DOI: 10.1016/j.annemergmed.2016.08.372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Lee W, Song J, Son JH, Gutierrez MP, Kang T, Kim D, Lee LP. Solar optics-based active panel for solar energy storage and disinfection of greywater. Biomicrofluidics 2016; 10:054120. [PMID: 27822328 PMCID: PMC5085975 DOI: 10.1063/1.4965855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/10/2016] [Indexed: 06/02/2023]
Abstract
Smart city and innovative building strategies are becoming increasingly more necessary because advancing a sustainable building system is regarded as a promising solution to overcome the depleting water and energy. However, current sustainable building systems mainly focus on energy saving and miss a holistic integration of water regeneration and energy generation. Here, we present a theoretical study of a solar optics-based active panel (SOAP) that enables both solar energy storage and photothermal disinfection of greywater simultaneously. Solar collector efficiency of energy storage and disinfection rate of greywater have been investigated. Due to the light focusing by microlens, the solar collector efficiency is enhanced from 25% to 65%, compared to that without the microlens. The simulation of greywater sterilization shows that 100% disinfection can be accomplished by our SOAP for different types of bacteria including Escherichia coli. Numerical simulation reveals that our SOAP as a lab-on-a-wall system can resolve the water and energy problem in future sustainable building systems.
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Affiliation(s)
- W Lee
- Department of Mechanical Engineering, Sogang University , 04107 Seoul, South Korea
| | | | - J H Son
- Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Program, University of California , Berkeley, California 94270, USA
| | - M P Gutierrez
- Department of Architecture, University of California , Berkeley, California 94270, USA
| | - T Kang
- Department of Chemical and Biomolecular Engineering, Sogang University , 04107 Seoul, South Korea
| | - D Kim
- Department of Mechanical Engineering, Sogang University , 04107 Seoul, South Korea
| | - L P Lee
- Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Program, University of California , Berkeley, California 94270, USA
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Park JE, Lee HS, Cho HD, Kang T. AB0978 The Association of Power Doppler Signal Grades with The Serum Inflammatory Marker Level. Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.2638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Kang T, Banquy X, Heo J, Lim C, Lynd NA, Lundberg P, Oh DX, Lee HK, Hong YK, Hwang DS, Waite JH, Israelachvili JN, Hawker CJ. Mussel-Inspired Anchoring of Polymer Loops That Provide Superior Surface Lubrication and Antifouling Properties. ACS Nano 2016; 10:930-7. [PMID: 26695175 PMCID: PMC4932843 DOI: 10.1021/acsnano.5b06066] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We describe robustly anchored triblock copolymers that adopt loop conformations on surfaces and endow them with unprecedented lubricating and antifouling properties. The triblocks have two end blocks with catechol-anchoring groups and a looping poly(ethylene oxide) (PEO) midblock. The loops mediate strong steric repulsion between two mica surfaces. When sheared at constant speeds of ∼2.5 μm/s, the surfaces exhibit an extremely low friction coefficient of ∼0.002-0.004 without any signs of damage up to pressures of ∼2-3 MPa that are close to most biological bearing systems. Moreover, the polymer loops enhance inhibition of cell adhesion and proliferation compared to polymers in the random coil or brush conformations. These results demonstrate that strongly anchored polymer loops are effective for high lubrication and low cell adhesion and represent a promising candidate for the development of specialized high-performance biomedical coatings.
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Affiliation(s)
- Taegon Kang
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Materials Department, University of California, Santa Barbara, California 93106, United States
- Chemical Research Institute, Samsung SDI Inc., Gocheon-Dong, Uiwang-Si, Gyeonggi-Do 437-711, Republic of Korea
| | - Xavier Banquy
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Corresponding Authors: . . .
| | - Jinhwa Heo
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Materials Department, University of California, Santa Barbara, California 93106, United States
| | - Chanoong Lim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Nathaniel A. Lynd
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
| | - Pontus Lundberg
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
| | - Dongyeop X. Oh
- Ocean Science and Technology Institute, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Han-Koo Lee
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Yong-Ki Hong
- Department of Biotechnology, Pukyong National University, Busan 608-737, Republic of Korea
| | - Dong Soo Hwang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
- Ocean Science and Technology Institute, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
- Division of Integrative Biosciences and Biotechnology, School of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
- Corresponding Authors: . . .
| | - John Herbert Waite
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Materials Department, University of California, Santa Barbara, California 93106, United States
- Corresponding Authors: . . .
| | - Jacob N. Israelachvili
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Corresponding Authors: . . .
| | - Craig J. Hawker
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
- Materials Department, University of California, Santa Barbara, California 93106, United States
- Corresponding Authors: . . .
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Kang T, Oh DX, Heo J, Lee HK, Choy S, Hawker CJ, Hwang DS. Formation, Removal, and Reformation of Surface Coatings on Various Metal Oxide Surfaces Inspired by Mussel Adhesives. ACS Appl Mater Interfaces 2015; 7:24656-24662. [PMID: 26492561 DOI: 10.1021/acsami.5b06910] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mussels survive by strongly attaching to a variety of different surfaces, primarily subsurface rocks composed of metal oxides, through the formation of coordinative interactions driven by protein-based catechol repeating units contained within their adhesive secretions. From a chemistry perspective, catechols are known to form strong and reversible complexes with metal ions or metal oxides, with the binding affinity being dependent on the nature of the metal ion. As a result, catechol binding with metal oxides is reversible and can be broken in the presence of a free metal ion with a higher stability constant. It is proposed to exploit this competitive exchange in the design of a new strategy for the formation, removal, and reformation of surface coatings and self-assembled monolayers (SAM) based on catechols as the adhesive unit. In this study, catechol-functionalized tri(ethylene oxide) (TEO) was synthesized as a removable and recoverable self-assembled monolayer (SAM) for use on oxides surfaces. Attachment and detachment of these catechol derivatives on a variety of surfaces was shown to be reversible and controllable by exploiting the high stability constant of catechol to soluble metal ions, such as Fe(III). This tunable assembly based on catechol binding to metal oxides represents a new concept for reformable coatings with applications in fields ranging from friction/wettability control to biomolecular sensing and antifouling.
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Affiliation(s)
- Taegon Kang
- Chemical Research Institute, Samsung Cheil Industries, Inc. , Uiwang-si, Gyeonggi-do, 437-711, Republic of Korea
| | | | | | - Han-Koo Lee
- Pohang Accelerator Laboratory , Pohang, Gyeongbuk 790-784, Republic of Korea
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Lee H, Park J, Park C, Kang T. FRI0242 Value of Ultrasound in Carpal Tunnel Syndrome: Useful Method for Treatment and Therapeutic Response after Steroid Injection. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2014-eular.3936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Huang SY, Huang JJ, Kang T, Diao DF, Duan YZ. Coating NiTi archwires with diamond-like carbon films: reducing fluoride-induced corrosion and improving frictional properties. J Mater Sci Mater Med 2013; 24:2287-92. [PMID: 23793493 DOI: 10.1007/s10856-013-4988-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 06/14/2013] [Indexed: 05/27/2023]
Abstract
This study aims to coat diamond-like carbon (DLC) films onto nickel-titanium (NiTi) orthodontic archwires. The film protects against fluoride-induced corrosion and will improve orthodontic friction. 'Mirror-confinement-type electron cyclotron resonance plasma sputtering' was utilized to deposit DLC films onto NiTi archwires. The influence of a fluoride-containing environment on the surface topography and the friction force between the brackets and archwires were investigated. The results confirmed the superior nature of the DLC coating, with less surface roughness variation for DLC-coated archwires after immersion in a high fluoride ion environment. Friction tests also showed that applying a DLC coating significantly decreased the fretting wear and the coefficient of friction, both in ambient air and artificial saliva. Thus, DLC coatings are recommended to reduce fluoride-induced corrosion and improve orthodontic friction.
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Affiliation(s)
- S Y Huang
- Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, 145 West Changle Rd., Xi'an, 710032, China
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Albertazzi L, Mickler FM, Pavan GM, Salomone F, Bardi G, Panniello M, Amir E, Kang T, Killops KL, Bräuchle C, Amir RJ, Hawker CJ. Enhanced bioactivity of internally functionalized cationic dendrimers with PEG cores. Biomacromolecules 2012; 13:4089-97. [PMID: 23140570 PMCID: PMC3524974 DOI: 10.1021/bm301384y] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hybrid dendritic-linear block copolymers based on a 4-arm poly(ethylene glycol) (PEG) core were synthesized using an accelerated AB2/CD2 dendritic growth approach through orthogonal amine/epoxy and thiol-yne chemistries. The biological activity of these 4-arm and the corresponding 2-arm hybrid dendrimers revealed an enhanced, dendritic effect with an exponential increase in cell internalization concomitant with increasing amine end groups and low cytotoxicity. Furthermore, the ability of these hybrid dendrimers to induce endosomal escape combined with their facile and efficient synthesis makes them attractive platforms for gene transfection. The 4-arm-based dendrimer showed significantly improved DNA binding and gene transfection capabilities in comparison with the 2-arm derivative. These results combined with the MD simulation indicate a significant effect of both the topology of the PEG core and the multivalency of these hybrid macromolecules on their DNA binding and delivery capablities.
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Affiliation(s)
- Lorenzo Albertazzi
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106-5121, USA
- NEST, Scuola Normale Superiore and CNR-INFM, and IIT@NEST, Center for Nanotechnology Innovation, Piazza San Silvestro 12, 56126 Pisa, Italy
| | - Frauke M. Mickler
- Department of Chemistry, Ludwig-Maximilians-Universität München, Center for NanoScience (CeNS) and Center for Integrated Protein Science Munich (CIPSM), Butenandtstr. 5-13, D-81377, München, Germany
| | - Giovanni M. Pavan
- Laboratory of Applied Mathematics and Physics (LaMFI),University of Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, 6928, Switzerland
| | - Fabrizio Salomone
- NEST, Scuola Normale Superiore and CNR-INFM, and IIT@NEST, Center for Nanotechnology Innovation, Piazza San Silvestro 12, 56126 Pisa, Italy
| | - Giuseppe Bardi
- NEST, Scuola Normale Superiore and CNR-INFM, and IIT@NEST, Center for Nanotechnology Innovation, Piazza San Silvestro 12, 56126 Pisa, Italy
| | - Mariangela Panniello
- NEST, Scuola Normale Superiore and CNR-INFM, and IIT@NEST, Center for Nanotechnology Innovation, Piazza San Silvestro 12, 56126 Pisa, Italy
| | - Elizabeth Amir
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106-5121, USA
| | - Taegon Kang
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106-5121, USA
| | - Kato L. Killops
- US Army RDECOM Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD 21010
| | - Christoph Bräuchle
- Department of Chemistry, Ludwig-Maximilians-Universität München, Center for NanoScience (CeNS) and Center for Integrated Protein Science Munich (CIPSM), Butenandtstr. 5-13, D-81377, München, Germany
| | - Roey J. Amir
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106-5121, USA
- Department of Organic Chemistry, School of Chemistry, Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Craig J. Hawker
- Materials Research Laboratory, University of California, Santa Barbara, CA 93106-5121, USA
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Heo J, Kang T, Jang SG, Hwang DS, Spruell JM, Killops KL, Waite JH, Hawker CJ. Improved performance of protected catecholic polysiloxanes for bioinspired wet adhesion to surface oxides. J Am Chem Soc 2012. [PMID: 23181614 DOI: 10.1021/ja309044z] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A facile synthetic strategy for introducing catecholic moieties into polymeric materials based on a readily available precursor (eugenol) and efficient chemistries [tris(pentafluorophenyl)borane-catalyzed silation and thiol-ene coupling] is reported. Silyl protection is shown to be critical for the oxidative stability of catecholic moieties during synthesis and processing, which allows functionalized polysiloxane derivatives to be fabricated into 3D microstructures as well as 2D patterned surfaces. Deprotection gives stable catechol surfaces whose adhesion to a variety of oxide surfaces can be precisely tuned by the level of catechol incorporation. The advantage of silyl protection for catechol-functionalized polysiloxanes is demonstrated and represents a promising and versatile new platform for underwater surface treatments.
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Affiliation(s)
- Jinhwa Heo
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
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16
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Bae S, Kim YG, Choi J, Hong J, Lee S, Kang T, Jeon H, Hong K, Kim E, Kwak A, Lee CK, Yoo B, Park YB, Song EY, Kim S. Elevated interleukin-32 expression in granulomatosis with polyangiitis. Rheumatology (Oxford) 2012; 51:1979-88. [DOI: 10.1093/rheumatology/kes163] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Dong C, Wu Y, Wang Y, Wang C, Kang T, Rychahou PG, Chi YI, Evers BM, Zhou BP. Interaction with Suv39H1 is critical for Snail-mediated E-cadherin repression in breast cancer. Oncogene 2012; 32:1351-62. [PMID: 22562246 PMCID: PMC3703513 DOI: 10.1038/onc.2012.169] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Expression of E-cadherin, a hallmark of epithelial-mesenchymal transition (EMT), is often lost due to promoter DNA methylation in basal-like breast cancer (BLBC), which contributes to the metastatic advantage of this disease; however, the underlying mechanism remains unclear. Here, we identified that Snail interacted with Suv39H1 (suppressor of variegation 3-9 homolog 1), a major methyltransferase responsible for H3K9me3 that intimately links to DNA methylation. We demonstrated that the SNAG domain of Snail and the SET domain of Suv39H1 were required for their mutual interactions. We found that H3K9me3 and DNA methylation on the E-cadherin promoter were higher in BLBC cell lines. We showed that Snail interacted with Suv39H1 and recruited it to the E-cadherin promoter for transcriptional repression. Knockdown of Suv39H1 restored E-cadherin expression by blocking H3K9me3 and DNA methylation and resulted in the inhibition of cell migration, invasion and metastasis of BLBC. Our study not only reveals a critical mechanism underlying the epigenetic regulation of EMT, but also paves a way for the development of new treatment strategies against this disease.
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Affiliation(s)
- C Dong
- Department of Molecular and Cellular Biochemistry, The University of Kentucky College of Medicine, Lexington, KY, USA
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18
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Alvarez R, Chen C, Hung C, Kang T, Lee S, Wu T. Enhancement of the antigen-specific T cell immune responses and therapeutic antitumor effects generated by therapeutic HPV DNA vaccine by histone deacetylase inhibitor. Gynecol Oncol 2012. [DOI: 10.1016/j.ygyno.2011.12.335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Kang S, Kim S, Kang T, Yoon C, Ko S, Hur M, Lee H, Seol C. 528 Short-term Outcomes of Immediate Breast Reconstruction After Mastectomy Using Implant or Tissue Expander in Patients with Breast Cancer. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)70593-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Kloepfer K, Vrtis R, Pappas T, Kang T, Lee W, Evans M, Gangnon R, Lemanske R, Gern J. Bacterial Detection In The Fall Is Associated With Increased Viral Respiratory Infections. J Allergy Clin Immunol 2012. [DOI: 10.1016/j.jaci.2011.12.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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21
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Nguyen D, Alavi MV, Kim KY, Kang T, Scott RT, Noh YH, Lindsey JD, Wissinger B, Ellisman MH, Weinreb RN, Perkins GA, Ju WK. A new vicious cycle involving glutamate excitotoxicity, oxidative stress and mitochondrial dynamics. Cell Death Dis 2011; 2:e240. [PMID: 22158479 PMCID: PMC3252734 DOI: 10.1038/cddis.2011.117] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Glutamate excitotoxicity leads to fragmented mitochondria in neurodegenerative diseases, mediated by nitric oxide and S-nitrosylation of dynamin-related protein 1, a mitochondrial outer membrane fission protein. Optic atrophy gene 1 (OPA1) is an inner membrane protein important for mitochondrial fusion. Autosomal dominant optic atrophy (ADOA), caused by mutations in OPA1, is a neurodegenerative disease affecting mainly retinal ganglion cells (RGCs). Here, we showed that OPA1 deficiency in an ADOA model influences N-methyl-D-aspartate (NMDA) receptor expression, which is involved in glutamate excitotoxicity and oxidative stress. Opa1(enu/+) mice show a slow progressive loss of RGCs, activation of astroglia and microglia, and pronounced mitochondrial fission in optic nerve heads as found by electron tomography. Expression of NMDA receptors (NR1, 2A, and 2B) in the retina of Opa1(enu/+) mice was significantly increased as determined by western blot and immunohistochemistry. Superoxide dismutase 2 (SOD2) expression was significantly decreased, the apoptotic pathway was activated as Bax was increased, and phosphorylated Bad and BcL-xL were decreased. Our results conclusively demonstrate that not only glutamate excitotoxicity and/or oxidative stress alters mitochondrial fission/fusion, but that an imbalance in mitochondrial fission/fusion in turn leads to NMDA receptor upregulation and oxidative stress. Therefore, we propose a new vicious cycle involved in neurodegeneration that includes glutamate excitotoxicity, oxidative stress, and mitochondrial dynamics.
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Affiliation(s)
- D Nguyen
- The Sophie and Arthur Brody Laboratory for Optic Nerve Biology, Hamilton Glaucoma Center, Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
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22
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Hwang E, Jung S, Kang T, Kwon D, Park K, Ryu S. UP-03.145 T2 Ureteral Tumor and Severe Hydronephrosis: Poor Prognostic Factors in Upper Urinary Tract Transitional Cell Carcinoma. Urology 2011. [DOI: 10.1016/j.urology.2011.07.1234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Choi SQ, Jang SG, Pascall AJ, Dimitriou MD, Kang T, Hawker CJ, Squires TM. Synthesis of multifunctional micrometer-sized particles with magnetic, amphiphilic, and anisotropic properties. Adv Mater 2011; 23:2348-2352. [PMID: 21360773 DOI: 10.1002/adma.201003604] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Revised: 01/07/2011] [Indexed: 05/30/2023]
Affiliation(s)
- Siyoung Q Choi
- Department of Chemical Engineering, University of California-Santa Barbara, CA 93106, USA
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Amir RJ, Albertazzi L, Willis J, Khan A, Kang T, Hawker CJ. Multifunctional trackable dendritic scaffolds and delivery agents. Angew Chem Int Ed Engl 2011; 50:3425-9. [PMID: 21391296 PMCID: PMC3491073 DOI: 10.1002/anie.201007427] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/19/2011] [Indexed: 01/05/2023]
Affiliation(s)
- Roey J. Amir
- Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, CA 93106-5121, USA, Fax: (+1-805) 893-8797
| | - Lorenzo Albertazzi
- Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, CA 93106-5121, USA, Fax: (+1-805) 893-8797. NEST, Scuola Normale Superiore and CNR-INFM, and IIT@NEST, Center for Nanotechnology Innovation, Piazza San Silvestro 12, 56126 Pisa, Italy
| | - Jenny Willis
- Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, CA 93106-5121, USA, Fax: (+1-805) 893-8797
| | - Anzar Khan
- Department of Materials, Institute of Polymers, ETH-Zurich, Wolfgang-Pauli-Strasse 10, HCl H-520, 8093 Zurich Switzerland
| | - Taegon Kang
- Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, CA 93106-5121, USA, Fax: (+1-805) 893-8797
| | - Craig J. Hawker
- Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, CA 93106-5121, USA, Fax: (+1-805) 893-8797
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Amir RJ, Albertazzi L, Willis J, Khan A, Kang T, Hawker CJ. Multifunctional Trackable Dendritic Scaffolds and Delivery Agents. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201007427] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Song HC, Cho S, Kang T, Hodgkiss WS, Preston JR. Long-range acoustic communication in deep water using a towed array. J Acoust Soc Am 2011; 129:EL71-EL75. [PMID: 21428470 DOI: 10.1121/1.3554707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In September 2010 a long-range acoustic communication (LRAC10) experiment was carried out in deep water off the Southern California Coast. The experiment involved two mobile components: (1) a source towed slowly at a speed of 2-3 knots at ∼75-m depth and (2) a horizontal line array towed at 3.5 knots at a depth of ∼200 m. Phase-coherent communication sequences were transmitted in the frequency band of 200-300 Hz at various ranges (100-700 km). Initial analysis of the LRAC10 data demonstrates that an information rate of 50 bits/s can be achieved over ∼550-km range using quadrature-phase shift-keying (QPSK) modulation and error-correction coding combined with beamforming.
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Affiliation(s)
- H C Song
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0238, USA.
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27
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Holstein GR, Friedrich VL, Kang T, Kukielka E, Martinelli GP. Direct projections from the caudal vestibular nuclei to the ventrolateral medulla in the rat. Neuroscience 2011; 175:104-17. [PMID: 21163335 PMCID: PMC3029471 DOI: 10.1016/j.neuroscience.2010.12.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 11/23/2010] [Accepted: 12/08/2010] [Indexed: 02/07/2023]
Abstract
While the basic pathways mediating vestibulo-ocular, -spinal, and -collic reflexes have been described in detail, little is known about vestibular projections to central autonomic sites. Previous studies have primarily focused on projections from the caudal vestibular region to solitary, vagal and parabrachial nuclei, but have noted a sparse innervation of the ventrolateral medulla. Since a direct pathway from the vestibular nuclei to the rostral ventrolateral medulla would provide a morphological substrate for rapid modifications in blood pressure, heart rate and respiration with changes in posture and locomotion, the present study examined anatomical evidence for this pathway using anterograde and retrograde tract tracing and immunofluorescence detection in brainstem sections of the rat medulla. The results provide anatomical evidence for direct pathways from the caudal vestibular nuclear complex to the rostral and caudal ventrolateral medullary regions. The projections are conveyed by fine and highly varicose axons that ramify bilaterally, with greater terminal densities present ipsilateral to the injection site and more rostrally in the ventrolateral medulla. In the rostral ventrolateral medulla, these processes are highly branched and extremely varicose, primarily directed toward the somata and proximal dendrites of non-catecholaminergic neurons, with minor projections to the distal dendrites of catecholaminergic cells. In the caudal ventrolateral medulla, the axons of vestibular nucleus neurons are more modestly branched with fewer varicosities, and their endings are contiguous with both the perikarya and dendrites of catecholamine-containing neurons. These data suggest that vestibular neurons preferentially target the rostral ventrolateral medulla, and can thereby provide a morphological basis for a short latency vestibulo-sympathetic pathway.
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Affiliation(s)
- G R Holstein
- Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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28
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Xu S, Feng Z, Zhang M, Wu Y, Sang Y, Xu H, Lv X, Hu K, Cao J, Zhang R, Chen L, Liu M, Yun JP, Zeng YX, Kang T. hSSB1 binds and protects p21 from ubiquitin-mediated degradation and positively correlates with p21 in human hepatocellular carcinomas. Oncogene 2011; 30:2219-29. [PMID: 21242961 DOI: 10.1038/onc.2010.596] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Downregulation of hSSB1, a single-stranded DNA-binding protein, causes increased radiosensitivity, defective checkpoint activation and genomic instability. However, the mechanisms of hSSB1 function in these responses remain to be uncovered. Here, we present evidence that hSSB1 directly binds p21 and this interaction may prevent p21 from ubiquitin-mediated degradation. Furthermore, both promotion of the G1/S transition and abrogation of the G2/M checkpoints induced by hSSB1 knockdown are partially dependent on p21. Most importantly, hSSB1 and p21 levels are positively correlated in human hepatocellular carcinomas (HCC), as determined by immunostaining. Therefore, hSSB1 may positively modulate p21 to regulate cell cycle progression and DNA damage response, implicating hSSB1 as a novel, promising therapeutic target for cancers such as HCC.
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Affiliation(s)
- S Xu
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, China
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Ryu S, Kim S, Hwang E, Im C, Oh K, Jung S, Kang T, Kwon D, Park K. UP-1.26: The role of alpha 1(A) Adrenoceptor antagonist tamsulosin for the treatment of patients with lower urinary tract symptoms in women: the effect of nocturia and sleep quality. Urology 2010. [DOI: 10.1016/j.urology.2010.07.159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Smith SD, Bolwell BJ, Rybicki LA, Kang T, Dean R, Advani A, Thakkar S, Sobecks R, Kalaycio M, Pohlman B, Sweetenham JW. Comparison of outcomes after auto-SCT for patients with relapsed diffuse large B-cell lymphoma according to previous therapy with rituximab. Bone Marrow Transplant 2010; 46:262-6. [DOI: 10.1038/bmt.2010.95] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Huisden CM, Adesogan AT, Gaskin JM, Courtney CH, Raji AM, Kang T. Effect of feeding Mucuna pruriens on helminth parasite infestation in lambs. J Ethnopharmacol 2010; 127:669-673. [PMID: 19969060 DOI: 10.1016/j.jep.2009.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 11/24/2009] [Accepted: 12/01/2009] [Indexed: 05/28/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Mucuna pruriens is a tropical legume anecdotally reputed to have anthelmintic properties. This study was conducted to examine the validity of such claims. AIM OF THE STUDY The aim of this study was to determine if ingestion of Mucuna seeds reduces helminth parasite infestation in lambs. MATERIALS AND METHODS Thirty-six Dorper x Katahdin ram lambs were assigned to three treatments, a cottonseed meal based control diet, a diet in which Mucuna replaced cottonseed meal and the control diet with levamisole (7.5mg/kg body weight) administration. All diets were isonitrogenous and isocaloric. The 12 lambs in each treatment were assigned randomly to 4 pens, each containing 3 lambs. Lambs were trickle infected three times per week by gavage with infectious Haemonchus contortus larvae (2000 larvae/lamb) for 3 weeks. RESULTS Levamisole treatment decreased fecal egg counts by 87% and abomasal worm counts by 83%. Mucuna intake did not statistically affect fecal egg counts or abomasal worm counts, though numerical (P>0.10) reductions of 7.4% and 18.1%, respectively were evident. Anemia indicators, feed intake, and lamb growth were unaffected by treatment. CONCLUSIONS Levamisole reduced the Haemonchus parasite burden in lambs significantly but feeding Mucuna reduced the burden by levels unlikely to eliminate the clinical effects of parasitism.
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Affiliation(s)
- C M Huisden
- Department of Animal Sciences, Institute of Food and Agricultural Science, University of Florida, Gainesville, FL 32611, USA
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Kang T, Amir RJ, Khan A, Ohshimizu K, Hunt JN, Sivanandan K, Montañez MI, Malkoch M, Ueda M, Hawker CJ. Facile access to internally functionalized dendrimers through efficient and orthogonal click reactions. Chem Commun (Camb) 2010; 46:1556-8. [DOI: 10.1039/b921598k] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kang T, Ahn M, Johnstone P, Kao C, Ko S, Gardner T. MP-15.06: Enhancement of FCYttk-Armed Prostate-Restricted Replicative Adenovirus Effect with Prodrugs Gancyclovir and 5-FC In Prostate Cancer. Urology 2009. [DOI: 10.1016/j.urology.2009.07.840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Beck JB, Killops KL, Kang T, Sivanandan K, Bayles A, Mackay ME, Wooley KL, Hawker CJ. FACILE PREPARATION OF NANOPARTICLES BY INTRAMOLECULAR CROSSLINKING OF ISOCYANATE FUNCTIONALIZED COPOLYMERS. Macromolecules 2009; 42:5629-5635. [PMID: 20717499 DOI: 10.1021/ma900899v] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A new synthetic approach to the preparation of intramolecularly collapsed nanoparticles under mild, room temperature conditions has been developed from commercially available vinyl monomers. Reaction of isocyanate functionalized linear copolymers with a diamine in dilute solution leads to the efficient formation of nanoparticles where the diameter of the nanoparticle can be varied by controlling both the molecular weight and mole percentage of isocyanate repeat units. Physical properties for the intramolecularly collapsed nanoparticles were fully consistent with a three-dimensional structure and analysis of the collapse reaction revealed that approximately 75% of the isocyanate groups along the backbone underwent crosslinking with 25% being available for further reaction with mono-functional amines. This stepwise consumption of the isocyanates allows the chemical and physical properties of the nanoparticles to be further tuned and significantly opens up the range of nanoparticles that can be prepared using this mild and highly efficient chemistry.
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Affiliation(s)
- J Benjamin Beck
- Materials Research Laboratory University of California Santa Barbara, CA 93106-5121
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Lee S, Bae Y, Lee J, Kang T. Immediate breast reconstruction with contralateral pectoralis major myomammary flap for breast conserving surgery. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-5157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Abstract #5157
Purpose: The breast reconstruction techniques are mandatory in case of the indication permits for there has been lots of data showing no less survival as far as surgery keeps the principle of cancer surgery. It could be selected by many factors but mainly by breast size, site of tumor. The latissimus dorsi musculocutaneous flap (LDMCF) is one of the most commonly used techniques in early breast cancer patient who has small breast. But, it has difficulties to supply enough tissues to the widely excised tumor site. And especially in case of ptosis patient, reduction mammoplasty only is not enough to get the symmetry of the breast. We suggest a pectoralis major myomammary flap(PMMF) as a useful technique for the patients with ptosis.
 Methods: Seventeen patients with ptosis were treated with breast conserving using PMMF surgery. A quadrantectomy rather than lumpectomy was performed through a planned skin incision, and axillary lymph node dissection was performed according to the sentinel lymph node result. PMMF is harvested carefully without perforating branch injury of internal thoracic artery. And reconstruction was done by the PMMF through the medial tunnel between both breasts.
 Results: Among those of seventeen patients, seroma occurred in two patients and no necrosis was occurred. The cosmetic result showed good in fifteen and excellent in two patients based on four-point scoring system of breast cosmetics.
 Conclusions: After enough quadrantectomy to keep the cancer surgery principles, PMMF was quite useful to supply proper tissues for breast reconstructions, especially for the ptosis patient.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5157.
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Affiliation(s)
- S Lee
- 1 General Surgery, Pusan National University Hospital, Pusan, Korea
- 2 General Surgery, Pusan National University Hospital, Pusan, Korea
- 4 General Surgery, Maryknoll General Hospital, Pusan, Korea
| | - Y Bae
- 1 General Surgery, Pusan National University Hospital, Pusan, Korea
- 2 General Surgery, Pusan National University Hospital, Pusan, Korea
- 4 General Surgery, Maryknoll General Hospital, Pusan, Korea
| | - J Lee
- 3 General Surgery, Pusan National University Hospital, Pusan, Korea
- 1 General Surgery, Pusan National University Hospital, Pusan, Korea
- 2 General Surgery, Pusan National University Hospital, Pusan, Korea
- 4 General Surgery, Maryknoll General Hospital, Pusan, Korea
| | - T Kang
- 1 General Surgery, Pusan National University Hospital, Pusan, Korea
- 2 General Surgery, Pusan National University Hospital, Pusan, Korea
- 4 General Surgery, Maryknoll General Hospital, Pusan, Korea
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Affiliation(s)
- K. Oh
- Chung–Ang University, Seoul, Korea
| | - M. Park
- Chung–Ang University, Seoul, Korea
| | - T. Kang
- Seoul National University, Seoul, Korea
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Abstract
2077 Background: High-grade gliomas are generally resistant to modern chemotherapy. In the case of glioblastoma multiforme, median overall survival has been less than 12 months and progression free survival of less than 4 months. For patients with recurrent GBMs, the 6 month progression free survival is 15–20%. The combination of irinotecan and bevacizumab is an active regimen in the treatment of this disease. Herein we report the experiences with this regimen at our institution with the objective of identifying a therapy with a better outcome than historical results. Methods: Single institutional, retrospective review of 27 patients with recurrent or progressive high grade gliomas treated at the Cleveland Clinic Brain Tumor Institute from 7/2005 through 10/2006. Patients had progressed on at least one prior chemotherapy. Patients with prior irinotecan or bevacizumab were excluded. Patients were analyzed on an intention-to-treat basis, and outcomes estimated by the Kaplan-Meier method. Results: The median age of the group was 46 years (range 5–69). The median number of prior therapies was 2 (range 1–10). Twenty of 27 patients have progressed (74%), and 11 of 27 patients have died (41%). Kaplan-Meier estimates for outcomes are summarized in the table . Progression-free survival at 6 months is 46 %, with median of 5.1 months. Overall survival at 6 months is 84%, with median of 12.6 months. In 7 patients, treatment was terminated early prior to progression. Significant toxicities include: one patient who developed hematuria, one patient with deep venous thrombosis and one patient who experienced intracranial hemorrhage. Conclusions: Our experience suggests that the combination of irinotecan and bevacizumab improves the 6-month progression-free survival when compared to historical figures. The rate of severe toxicities is consistent with prior reports and mandates careful selection of patients. Further randomized, phase 3 studies should be done to validate these results. [Table: see text] No significant financial relationships to disclose.
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Affiliation(s)
- T. Kang
- Cleveland Clinic Taussig Cancer Center, Cleveland, OH
| | - T. Jin
- Cleveland Clinic Taussig Cancer Center, Cleveland, OH
| | - D. Peereboom
- Cleveland Clinic Taussig Cancer Center, Cleveland, OH
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Kang T, Nichols P, Skinner E, Groshen S, Valin G, Ye W, Raghavan D. Functional heterogeneity of prostatic intra-epithelial neoplasia: Length of hormonal therapy influences response. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.4648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
4648 Background: Prostatic intraepithelial neoplasia (PIN) is a premalignant lesion of the prostate etiologically linked to prostate cancer. While androgen deprivation therapy (ADT) has been used to reduce prostate cancer, there are controversial data regarding the effect of ADT on PIN. We hypothesized that PIN is a heterogeneous entity with respect to hormone responsiveness, that this may explain aspects of the heterogeneity in the natural history of this disease, and have used the clinical model of ADT followed by radical prostatectomy as a test of this hypothesis. Methods: We performed a retrospective study on a cohort of patients who underwent prostatectomy with biopsy proven prostate cancer. Study patients were those who must have received at least 3 months of ADT at the discretion of their surgeons. Patients from the same cohort who did not undergo ADT were used as controls. Patients were randomly selected from the database and their pathology slides were reviewed by a blinded pathologist looking for presence of PIN with an independent observer. Fisher’s exact test was used to compare the proportions of subjects who had residual PIN in the study group and the control group. Exact logistic regression was used to evaluate the duration of ADT in PIN regression. Results: Eighteen patients initially diagnosed with PIN who did not receive hormonal therapy were identified; 28 patients with PIN who underwent hormonal therapy were also studied. All patients who did not receive hormonal therapy had residual PIN whereas 7 of 28 patients undergoing ADT had no residual PIN (p = 0.043). Evaluation of hormonal therapy between responders and non-responders showed statistically significant association between PIN regression and hormone therapy duration (p < 0.001). However PIN response to ADT was not uniform as 16% of patients with ADT longer than 6 months had residual PIN, suggesting variable sensitivity of PIN to ADT. Conclusions: Our results demonstrate that ADT does cause PIN regression, and that there is heterogeneity in this effect with respect to hormonal duration. We propose for future prospective, multi-centered, randomized trials in which ADT impact on PIN is characterized further. No significant financial relationships to disclose.
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Affiliation(s)
- T. Kang
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
| | - P. Nichols
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
| | - E. Skinner
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
| | - S. Groshen
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
| | - G. Valin
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
| | - W. Ye
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
| | - D. Raghavan
- Cleveland Clinic Foundation, Cleveland, OH; University of Southern California, Los Angeles, CA
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Affiliation(s)
- L. B. Anthony
- LSUHSC New Orleans, New Orleans, LA; Vanderbilt Univ, Nashville, TN
| | - T. Kang
- LSUHSC New Orleans, New Orleans, LA; Vanderbilt Univ, Nashville, TN
| | - Y. Shyr
- LSUHSC New Orleans, New Orleans, LA; Vanderbilt Univ, Nashville, TN
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Abstract
[reaction: see text]. The solution and solid-state photochemistry of a series of aryl 1-phenylcyclopentyl ketones (1) was investigated. While typical Norrish type I products were formed in solution, irradiation of crystals of 1 afforded the novel oxetanes 3 and 4 regiospecifically. The formation of the oxetanes is believed to occur through Norrish type I cleavage and hydrogen abstraction, producing an alkene and an aldehyde, followed by a Paternò-Büchi reaction within the crystal lattice cage.
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Affiliation(s)
- T Kang
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vanouver, British Columbia, Canada V6T 1Z1
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Kang T, Yi J, Guo A, Wang X, Overall CM, Jiang W, Elde R, Borregaard N, Pei D. Subcellular distribution and cytokine- and chemokine-regulated secretion of leukolysin/MT6-MMP/MMP-25 in neutrophils. J Biol Chem 2001; 276:21960-8. [PMID: 11282999 DOI: 10.1074/jbc.m007997200] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Leukolysin, originally isolated from human leukocytes, is the sixth member of the membrane-type matrix metalloproteinase (MT-MMP) subfamily with a potential glycosylphosphatidylinositol (GPI) anchor. To understand its biological functions, we screened subpopulations of leukocytes and localized the expression of leukolysin at the mRNA level to neutrophils. Polyclonal and mono-specific antisera raised against a synthetic peptide from its hinge region recognized a major protein species at 56 kDa and several minor forms between 38 and 45 kDa in neutrophil lysates. In resting neutrophils, leukolysin is distributed among specific granules ( approximately 10%), gelatinase granules ( approximately 40%), secretory vesicles ( approximately 30%), and the plasma membrane ( approximately 20%), a pattern distinct from that of neutrophil MMP-8 and MMP-9. Consistent with its membrane localization and its reported GPI anchor, leukolysin partitions into the detergent phase of Triton X-114 and can be released from intact resting neutrophils by glycosylphosphatidylinositol-specific phospholipase C. Phorbol myristate acetate stimulates neutrophils to discharge 100% of leukolysin from specific and gelatinase granules and approximately 50% from the secretory vesicles and plasma membrane, suggesting that leukolysin can be mobilized by physiological signals to the extracellular milieu as a soluble enzyme. Indeed, interleukin 8, a neutrophil chemoattractant, triggered a release of approximately 85% of cellular leukolysins by a process resistant to a mixture of proteinase inhibitors, including aprotinin, BB-94, pepstatin, and E64. Finally, purified recombinant leukolysin can degrade components of the extracellular matrix. These results not only establish leukolysin as the first neutrophil-specific MT-MMP but also implicate it as a cytokine/chemokine-regulated effector during innate immune responses or tissue injury.
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Affiliation(s)
- T Kang
- Departments of Pharmacology and Neurosciences, University of Minnesota School of Medicine, Minneapolis, Minnesota 55455, USA
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Iida J, Pei D, Kang T, Simpson MA, Herlyn M, Furcht LT, McCarthy JB. Melanoma chondroitin sulfate proteoglycan regulates matrix metalloproteinase-dependent human melanoma invasion into type I collagen. J Biol Chem 2001; 276:18786-94. [PMID: 11278606 DOI: 10.1074/jbc.m010053200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor cell adhesion and proteolysis of the extracellular matrix proteins surrounding the cells are tightly linked processes in tumor invasion. In this study, we sought to identify components of the cell surface of a vertical growth phase melanoma cell line, WM1341D, that mediate invasive cellular behavior. We determined by antisense inhibition that melanoma chondroitin sulfate proteoglycan (MCSP) and membrane-type 3 matrix metalloproteinase (MT3-MMP) expressed on WM1341D are required for invasion of type I collagen and degradation of type I gelatin. MT3-MMP co-immunoprecipitated with MCSP in WM1341D melanoma cells cultured on type I collagen or laminin. The association between MT3-MMP and MCSP was largely disrupted by removing chondroitin sulfate glycosaminoglycan (CS) from the cell surface, suggesting CS could mediate the association between the two cell surface core proteins. Recombinant MT3-MMP and MT3-MMP from whole cell lysates of WM1341D cells were specifically eluted from CS- conjugated affinity columns. The results indicate that MT3-MMP possesses the potential to promote melanoma invasion and proteolysis and that the formation of a complex between MT3-MMP and MCSP may be a crucial step in activating these processes.
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Affiliation(s)
- J Iida
- Department of Laboratory Medicine and Pathology, University of Minnesota Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA
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La J, Kim T, Sung T, Kang T, Lee J, Yang I. Involvement of nitric oxide and vasoactive intestinal peptide in the nonadrenergic-noncholinergic relaxation of the porcine retractor penis muscle. Jpn J Pharmacol 2001; 86:236-43. [PMID: 11459127 DOI: 10.1254/jjp.86.236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Neurotransmitters mediating nonadrenergic-noncholinergic (NANC) relaxation were investigated in strips of porcine retractor penis muscle (RPM). Muscle tone was raised by phenylephrine (1 microM) in the presence of atropine (1 microM) and guanethidine (50 microM). Upon electrical field stimulation (1 ms, 80 V, 1-32 Hz for 10 s), the initial fast relaxation was followed by the slow relaxation. Although the fast and the slow relaxation were completely abolished by tetrodotoxin (1 microM), they showed different pharmacological sensitivities to the nitric oxide (NO) synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME, 0.1 mM). The fast relaxation was markedly inhibited by L-NAME in an L-arginine reversible manner and by oxyhemoglobin (50 microM), while the slow relaxation was hardly blocked by L-NAME. L-NAME and alpha-chymotrypsin (alpha-CT, 3 U/ml) selectively inhibited the fast and the slow relaxation, respectively. Alpha-CT abolished L-NAME-resistant slow relaxation, and L-NAME completely abolished the alpha-CT-resistant fast relaxation. Alpha-CT-resistant relaxation was not significantly different from the digitally calculated L-NAME-sensitive component, and L-NAME-resistant relaxation was similar to the digitally calculated alpha-CT-sensitive component. Vasoactive intestinal peptide (VIP, 0.003-0.1 microM) relaxed porcine RPM in a concentration-dependent manner. The effect of a VIP was partially inhibited by a VIP receptor antagonist, VIP(10-28) (1 and 3 microM). L-NAME-resistant relaxation was also reduced by VIP(10-28) (3 microM) and by another putative antagonist, VIP(6-28) (1 microM), although the effects of the two antagonists were somewhat inconsistent. From the histochemical staining, it was verified that nerve bundles that showed VIP-like immunoreactivities were also positive for the NADPH diaphorase reaction. These results suggest that NO and peptide neurotransmitter(s) including VIP mediate the NANC relaxation in porcine RPM.
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Affiliation(s)
- J La
- Department of Veterinary Physiology, College of Veterinary Medicine, Seoul National University, Suwon, Republic of Korea
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Baek WC, Kang T, Sohn HJ, Kho YT. In situ surface enhanced Raman spectroscopic study on the effect of dissolved oxygen on the corrosion film on low carbon steel in 0.01 M NaCl solution. Electrochim Acta 2001. [DOI: 10.1016/s0013-4686(01)00442-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Won MH, Kang T, Park S, Jeon G, Kim Y, Seo JH, Choi E, Chung M, Cho SS. The alterations of N-Methyl-D-aspartate receptor expressions and oxidative DNA damage in the CA1 area at the early time after ischemia-reperfusion insult. Neurosci Lett 2001; 301:139-42. [PMID: 11248442 DOI: 10.1016/s0304-3940(01)01625-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Delayed neuronal death in the CA1 of the hippocampus following global ischemia has been evoked by both the activation of N-methyl-D-aspartate receptor (NR) and the generate reactive oxygen species in the neurons. In the present study, we investigated whether oxidative DNA damages may be correlated with NR subunits (NR1 and NR2A/B) expression following ischemia insults in vivo. Thirty minutes after ischemia-reperfusion, the intensities of both NR and 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunoreactivities were markedly increased in neurons of CA1. However, NR2A/B and 8-OHdG immunoreactivities were enhanced in CA1 over 24 h after ischemia although NR1 immunoreactivity was decreased. These results suggest that oxidative stress and excitotoxicity in the CA1 may simultaneously trigger neuronal damages at early time after ischemia, and free radical damage including oxidative DNA damage may eventually promote the delayed neuronal death in this region.
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Affiliation(s)
- M H Won
- Department of Anatomy, College of Medicine, Seoul National University, Yongon-Dong, Chongno-Gu, 110-799, Seoul, South Korea
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Kang T, Yi J, Yang W, Wang X, Jiang A, Pei D. Functional characterization of MT3-MMP in transfected MDCK cells: progelatinase A activation and tubulogenesis in 3-D collagen lattice. FASEB J 2000; 14:2559-68. [PMID: 11099475 DOI: 10.1096/fj.00-0269com] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
MT3-MMP, a membrane-anchored matrix metalloproteinase, has been proposed to participate in the remodeling of extracellular matrix either by direct proteolysis or via activating other enzymes such as progelatinase A. To test this hypothesis, we analyzed the effect of exogenously transfected MT3-MMP in a tissue remodeling system: growth and tubulogenesis of Madin-Darby canine kidney (MDCK) cells in collagen gels. Although the parental cells require MMP activities for both growth and tubulogenesis, over-expression of wild-type MT3-MMP, but not its catalytically inactive mutant, leads to further enhancement of both processes, independent of its downstream substrate, progelatinase A. Mechanistically, MT3-MMP accomplishes such an effect by displaying on cell surfaces as active species, ready to activate progelatinase A or degrade ECM molecules. These data strongly suggest that MT3-MMP possesses the potential to directly enhance the growth and invasiveness of cells in vivo, two critical processes for development and carcinogenesis.
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Affiliation(s)
- T Kang
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Kwon HY, Choi SY, Won MH, Kang T, Kang JH. Oxidative modification and inactivation of Cu,Zn-superoxide dismutase by 2,2'-azobis(2-amidinopropane) dihydrochloride. Biochim Biophys Acta 2000; 1543:69-76. [PMID: 11087942 DOI: 10.1016/s0167-4838(00)00197-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have investigated oxidative modification of human Cu, Zn-superoxide dismutase (SOD) by alkylperoxyl radicals and alkylperoxides. To generate free radicals, we used the hydrophilic azocompound, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). When Cu,Zn-SOD was incubated with AAPH, the enzyme activity was decreased gradually in a time-dependent manner. The oxidative damage to Cu,Zn-SOD by AAPH-derived radicals led to protein fragmentation which is associated with the inactivation of enzyme. Incubation with AAPH resulted in the release of copper ions from Cu,Zn-SOD and the generation of protein carbonyl derivatives. Catalase did not protect the fragmentation of Cu,Zn-SOD whereas azide, glutathione and a metal chelator, diethylenetriamine pentaacetic acid inhibited the protein fragmentation. When Cu,Zn-SOD that has been exposed to AAPH was subsequently analyzed by amino acid analysis, lysine, histidine, proline, and valine residues were particularly sensitive. It is suggested that oxidative damage of Cu,Zn-SOD by AAPH-derived radicals may induce the perturbation of cellular antioxidant defense systems and subsequently lead to the deleterious condition in cells.
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Affiliation(s)
- H Y Kwon
- Departmernt of Physiology, College of Medicine, Hallym University, Chunchon 200-702, South Korea
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Pei D, Kang T, Qi H. Cysteine array matrix metalloproteinase (CA-MMP)/MMP-23 is a type II transmembrane matrix metalloproteinase regulated by a single cleavage for both secretion and activation. J Biol Chem 2000; 275:33988-97. [PMID: 10945999 DOI: 10.1074/jbc.m006493200] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Matrix metalloproteinases characterized so far are either secreted or membrane anchored via a type I transmembrane domain or a glycosylphosphatidylinositol linkage. Lacking either membrane-anchoring mechanism, the newly discovered CA-MMP/MMP-23 was reported to be expressed as a cell-associated protein. In this report, we present evidence that CA-MMP is expressed as an integral membrane zymogen with an N-terminal signal anchor, and secreted as a fully processed mature enzyme. We further demonstrate that L(20)GAALSGLCLLSALALL(36) is required for this unique membrane localization as a signal anchor and its secretion is regulated by a proprotein convertase motif RRRR(79) sandwiched between its pro- and catalytic domains. Thus, CA-MMP is a type II transmembrane MMP that can be regulated by a single proteolytic cleavage for both activation and secretion, establishing a novel paradigm for protein trafficking and processing within the secretory pathway.
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Affiliation(s)
- D Pei
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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