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Lim YH, Saberi SA, Kamal K, Jalian HR, Avram M. Retrospective Analysis of US Litigations Involving Dermatologists From 2011 to 2022. Dermatol Surg 2024:00042728-990000000-00698. [PMID: 38416806 DOI: 10.1097/dss.0000000000004142] [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: 03/01/2024]
Abstract
BACKGROUND Physician malpractice lawsuits are climbing, and the reasons underlying litigation against dermatologists are unclear. OBJECTIVE To determine the reasons patients pursue litigation against dermatologists or dermatology practices. MATERIALS AND METHODS A retrospective analysis of all state and federal cases between 2011 and 2022 was performed after a query using "Dermatology" and "dermatologist" as search terms on 2 national legal data repositories. RESULTS The authors identified a total of 48 (37 state and 11 federal) lawsuits in which a practicing dermatologist or dermatology group practice was the defendant. The most common reason for litigation was unexpected harm (26 cases, 54.2%), followed by diagnostic error (e.g. incorrect or delayed diagnoses) (16 cases, 33.3%). Six cases resulted from the dermatologist failing to communicate important information, such as medication side effects or obtaining informed consent. Male dermatologists were sued at a rate 3.1 times higher than female dermatologists. CONCLUSION Although lawsuits from patients against dermatologists largely involve injury from elective procedures, clinicians should practice caution regarding missed diagnoses and ensure critical information is shared with patients to safeguard against easily avoidable litigation.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts
| | | | | | | | - Mathew Avram
- Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts
- Dermatology Laser and Cosmetic Center, Massachusetts General Hospital, Boston, Massachusetts
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2
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Teoh SE, Tan EWX, Teo YN, Basker G, Teo YH, Chai P, Wong RCC, Yip JWL, Kuntjoro I, Lim YH, Poh KK, Yeo TC, Kong WKF, Sia CH. Effects of medical therapy, transcatheter intervention, and surgery on outcomes of patients with functional mitral regurgitation: a systematic review and network meta-analysis. Eur Heart J 2023. [DOI: 10.1093/eurheartj/ehac779.072] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Ching-Hui Sia was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme.
Background
Functional mitral regurgitation (FMR) is the most common valvular heart disease worldwide. Despite recent major trials, the relative efficacy between medical therapy, transcatheter intervention, and surgery for the treatment of FMR remains poorly understood.
Purpose
We performed a systematic review and network meta-analysis of all published randomised controlled trials (RCTs) and observational studies to compare the efficacy between medical therapy, transcatheter intervention, and surgery on the clinical outcomes of patients with FMR.
Methods
Four electronic databases (PubMed, EMBASE, SCOPUS, and the Cochrane Library) were searched from inception to March 13, 2022, for studies reporting clinical outcomes in patients with FMR and comparing the efficacy between either medical therapy, transcatheter intervention, or surgery. Frequentist network meta-analysis models were utilised to summarise the studies. This study was registered in the International Prospective Register of Systematic Reviews.
Results
10 articles were included in the analysis, comprising a combined cohort of 1,981 patients. Network meta-analysis demonstrated that compared to medical therapy, transcatheter intervention achieved a lower relative risk in the composites of all-cause mortality (risk ratio [RR]: 0.43; 95% confidence interval [CI] 0.22-0.82) and mitral regurgitation (MR) severity grade ≥3+ (RR: 0.06; 95% CI 0.01-0.42). Compared to surgery, transcatheter intervention achieved a lower relative risk in the composites of cardiovascular death (RR: 0.36; 95% CI 0.17-0.75) and MR severity grade ≥3+ (RR: 0.25; 95% CI 0.09-0.70) and higher relative risk in the composite of heart failure hospitalisation (RR: 2.94; 95% CI 1.26-6.82). Compared to medical therapy, surgery achieved a higher relative risk in the composite of cardiovascular death (RR: 2.54; 95% CI 1.18-5.47) and lower relative risks in the composites of all-cause mortality (RR: 0.56; 95% CI 0.34-0.91) and heart failure hospitalisation (RR: 0.28; 95% CI 0.13-0.61).
Conclusion
Medical therapy, transcatheter intervention, and surgery in patients with FMR displayed differing effects on the various clinical outcomes. Further head-to-head trials are required to better understand the optimal treatment modality in this population.
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Affiliation(s)
- S E Teoh
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - E W X Tan
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y N Teo
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - G Basker
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y H Teo
- National University of Singapore, Department of Medicine , Singapore , Singapore
| | - P Chai
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - R C C Wong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - J W L Yip
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - I Kuntjoro
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - Y H Lim
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - K K Poh
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - T C Yeo
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - W K F Kong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - C H Sia
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
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3
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Lim YH. Prioritizing Mental Health in Residency. Cutis 2022; 109:E36-E38. [DOI: 10.12788/cutis.0551] [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: 11/20/2022]
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4
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Lim YH. Nuances in Training During the Age of Teledermatology. Cutis 2022; 109:E43-E45. [PMID: 35180072 DOI: 10.12788/cutis.0461] [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]
Abstract
COVID-19 was declared a global pandemic by the World Health Organization on March 11, 2020, and within the following 2 months, most states had issued mandatory stay-at-home orders, leaving many patients without access to outpatient care. Similar to many other outpatient-based specialties, dermatology quickly adopted telemedicine into clinical practice, and this expansion of virtual communication provided (1) increased access for patients living in remote areas, (2) ease of multidisciplinary collaboration, and (3) new opportunities for training and education. This article highlights the caveats of teledermatology, such as the need for excellent visual diagnostic skills and the vulnerability of patient privacy and protected information. Additionally, as teledermatology is poised to further expand in the future, it is critical to reflect on patient safety as well as its clinical efficacy in comparison to in-person evaluation.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, Harvard Combined Dermatology Residency, Boston, Massachusetts
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5
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Bergmann ML, Andersen ZJ, Amini H, Khan J, Lim YH, Loft S, Mehta A, Westendorp RG, Cole-Hunter T. Ultrafine particle exposure for bicycle commutes in rush and non-rush hour traffic: A repeated measures study in Copenhagen, Denmark. Environ Pollut 2022; 294:118631. [PMID: 34871646 DOI: 10.1016/j.envpol.2021.118631] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 06/13/2023]
Abstract
Ultrafine particles (UFP), harmful to human health, are emitted at high levels from motorized traffic. Bicycle commuting is increasingly encouraged to reduce traffic emissions and increase physical activity, but higher breathing rates increase inhaled UFP concentrations while in traffic. We assessed exposure to UFP while cycling along a fixed 8.5 km inner-city route in Copenhagen, on weekdays over six weeks (from September to October 2020), during morning and afternoon rush-hour, as well as morning non-rush-hour, traffic time periods starting from 07:45, 15:45, and 09:45 h, respectively. Continuous measurements were made (each second) of particle number concentration (PNC) and location. PNC levels were summarized and compared across time periods. We used generalized additive models to adjust for meteorological factors, weekdays and trends. A total of 61 laps were completed, during 28 days (∼20 per time period). Overall mean PNC was 18,149 pt/cm3 (range 256-999,560 pt/cm3) with no significant difference between morning rush-hour (18003 pt/cm3), afternoon rush-hour (17560 pt/cm3) and late morning commute (17560 pt/cm3) [p = 0.85]. There was substantial spatial variation of UFP exposure along the route with highest PNC levels measured at traffic intersections (∼38,000-42000 pt/cm3), multiple lane roads (∼38,000-40000 pt/cm3) and construction sites (∼44,000-51000 pt/cm3), while lowest levels were measured at smaller streets, areas with open built environment (∼12,000 pt/cm3), as well as at a bus-only zone (∼15,000 pt/cm3). UFP exposure in inner-city Copenhagen did not differ substantially when bicycling in either rush-hour or non-rush-hour, or morning or afternoon, traffic time periods. UFP exposure varied substantially spatially, with highest concentrations around intersections, multiple lane roads, and construction sites. This suggests that exposure to UFP is not necessarily reduced by avoiding rush-hours, but by avoiding sources of pollution along the bicycling route.
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Affiliation(s)
- M L Bergmann
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
| | - Z J Andersen
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - H Amini
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - J Khan
- Atmospheric Modelling Research Group, Department of Environmental Science, Aarhus University, Roskilde, Denmark; Danish Big Data Centre for Environment and Health (BERTHA), Aarhus University, Roskilde, Denmark
| | - Y H Lim
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - S Loft
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - A Mehta
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; Statistics Denmark, Copenhagen, Denmark
| | - R G Westendorp
- Department of Public Health and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - T Cole-Hunter
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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6
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Bergmann ML, Andersen ZJ, Amini H, Ellermann T, Hertel O, Lim YH, Loft S, Mehta A, Westendorp RG, Cole-Hunter T. Exposure to ultrafine particles while walking or bicycling during COVID-19 closures: A repeated measures study in Copenhagen, Denmark. Sci Total Environ 2021; 791:148301. [PMID: 34412377 PMCID: PMC8178061 DOI: 10.1016/j.scitotenv.2021.148301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 05/15/2023]
Abstract
Ultrafine particles (UFP; particulate matter <0.1 μm diameter) emitted from motorized traffic may be highly detrimental to health. Active mobility (walking, bicycling) is increasingly encouraged as a way to reduce traffic congestion and increase physical activity levels. However, it has raised concerns of increased exposure to UFP, due to increased breathing rates in traffic microenvironments, immediately close to their source. The recent Coronavirus Disease 2019 (COVID-19) societal closures reduced commuting needs, allowing a natural experiment to estimate contributions from motorized traffic to UFP exposure while walking or bicycling. From late-March to mid-July 2020, UFP was repeatedly measured while walking or bicycling, capturing local COVID-19 closure ('Phase 0') and subsequent phased re-opening ('Phase 1', '2', '2.1' & '3'). A DiSCmini continuously measured particle number concentration (PNC) in the walker/bicyclist's breathing zone. PNC while walking or bicycling was compared across phased re-openings, and the effect of ambient temperature, wind speed and direction was determined using regression models. Approximately 40 repeated 20-minute walking and bicycling laps were made over 4 months during societal re-opening phases related to the COVID-19 pandemic (late-March to mid-July 2020) in Copenhagen. Highest median PNC exposure of both walking (13,170 pt/cm3, standard deviation (SD): 3560 pt/cm3) and bicycling (21,477 pt/cm3, SD: 8964) was seen during societal closures (Phase 0) and decreased to 5367 pt/cm3 (SD: 2949) and 8714 pt/cm3 (SD: 4309) in Phase 3 of re-opening. These reductions in PNC were mainly explained by meteorological conditions, with most of the deviation explained by wind speed (14-22%) and temperature (10-13%). Highest PNC was observed along major roads and intersections. In conclusion, we observed decreases in UFP exposure while walking and bicycling during societal re-opening phases related to the COVID-19 pandemic, due largely to meteorological factors (e.g., wind speed and temperature) and seasonal variations in UFP levels.
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Affiliation(s)
- M L Bergmann
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
| | - Z J Andersen
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - H Amini
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - T Ellermann
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - O Hertel
- Department of Bioscience, Aarhus University, Roskilde, Denmark
| | - Y H Lim
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - S Loft
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - A Mehta
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; Statistics Denmark, Copenhagen, Denmark
| | - R G Westendorp
- Department of Public Health and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - T Cole-Hunter
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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7
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Atzmony L, Khan HM, Lim YH, Paller AS, Levinsohn JL, Holland KE, Mirza FN, Yin E, Ko CJ, Leventhal JS, Choate KA. Second-Hit, Postzygotic PMVK and MVD Mutations in Linear Porokeratosis. JAMA Dermatol 2020; 155:548-555. [PMID: 30942823 DOI: 10.1001/jamadermatol.2019.0016] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Importance Linear porokeratosis features linear and whorled configurations of keratotic papules and plaques, with coronoid lamellae present on histologic examination. Because linear porokeratosis manifests in the lines of Blaschko representing the dorsoventral migration patterns of keratinocyte precursors, it has been suggested that postzygotic somatic mutation underlies the disease. However, no genetic evidence has supported this hypothesis to date. Objective To identify genetic mutations associated with linear porokeratosis. Design, Setting, and Participants Paired whole-exome sequencing of affected skin and blood/saliva samples from 3 participants from 3 academic medical centers with clinical and histologic diagnoses of linear porokeratosis. Interventions or Exposures Whole-exome sequencing of paired blood/saliva and affected tissue samples isolated from linear porokeratosis lesions. Main Outcomes and Measures Germline and somatic genomic characteristics of participants with linear porokeratosis. Results Of the 3 participants, 2 were male. Participant ages ranged from 5 to 20 years old. We found a combination of a novel germline mutation and a novel somatic mutation within affected tissue in all cases. One participant had a germline heterozygous PMVK c.329G>A mutation and a somatic copy-neutral loss of heterozygosity confined to the lesional skin, while a second had a germline heterozygous PMVK c.79G>T mutation and an additional PMVK c.379C>T mutation in the lesional skin. In a third participant, there was a germline splice-site mutation in MVD (c.70 + 5G>A) and a somatic deletion in MVD causing frameshift and premature codon termination within the lesional skin (c.811_815del, p.F271Afs*33 frameshift). Conclusions and Relevance Our findings suggest that linear porokeratosis is associated with the presence of second-hit postzygotic mutations in the genes that encode enzymes within the mevalonate biosynthesis pathway, and provide further evidence that the mevalonate pathway may be a potential target for therapeutic intervention in porokeratosis.
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Affiliation(s)
- Lihi Atzmony
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Habib M Khan
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Amy S Paller
- Departments of Dermatology and Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Jonathan L Levinsohn
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | | | - Fatima Nadeem Mirza
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Emily Yin
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Christine J Ko
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Jonathan S Leventhal
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
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8
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Atzmony L, Lim YH, Hamilton C, Leventhal JS, Wagner A, Paller AS, Choate KA. Topical cholesterol/lovastatin for the treatment of porokeratosis: A pathogenesis-directed therapy. J Am Acad Dermatol 2020; 82:123-131. [PMID: 31449901 PMCID: PMC7039698 DOI: 10.1016/j.jaad.2019.08.043] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [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] [Received: 06/10/2019] [Revised: 08/13/2019] [Accepted: 08/20/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Porokeratosis is associated with mevalonate pathway gene mutations. Therapeutic options are few and often limited in efficacy. We hypothesized that topical therapy that aims to replenish cholesterol, an essential mevalonate pathway end-product, and block the accumulation of mevalonate pathway toxic metabolites could alleviate porokeratosis. OBJECTIVE To study the efficacy of topical cholesterol/lovastatin in different variants of porokeratosis. METHODS We enrolled a series of 5 porokeratosis patients,1 with disseminated superficial actinic porokeratosis, 2 with porokeratosis palmaris et plantaris disseminata, and 2 with linear porokeratosis. Patients were genotyped before initiation of therapy. Patients then applied topical cholesterol/lovastatin twice daily to a unilaterally defined treatment area for up to 3 months. The response was evaluated and patients photographed at every visit. RESULTS Three patients had MVD mutations, and 2 patients had PMVK mutations. Treatment with topical cholesterol/lovastatin (but not cholesterol alone) resulted in near complete clearance of disseminated superficial actinic porokeratosis lesions after 4 weeks of therapy and moderate improvement of porokeratosis palmaris et plantaris disseminata lesions and linear porokeratosis lesions. There were no adverse events. LIMITATIONS Case series design with a small number of patients. CONCLUSION Topical cholesterol/lovastatin is an effective and well-tolerated therapy for porokeratosis that underscores the utility of a pathogenesis-based therapy that replaces deficient end products and prevents accumulation of potentially toxic precursors.
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Affiliation(s)
- Lihi Atzmony
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Claire Hamilton
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Jonathan S Leventhal
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Annette Wagner
- Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Amy S Paller
- Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.
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Abstract
Tufted angioma (TA) is a rare vascular tumor characterized by histologic tufts of proliferating capillaries that occurs in infancy or early childhood, with a poorly understood pathogenesis. Though benign, TA can be associated with the Kasabach-Merritt phenomenon (KMP), a life-threatening consumptive coagulopathy and thrombocytopenia. Here, we explored the genetic mechanism underlying a case of TA associated with KMP via targeted sequencing of laser capture micro-dissected lesion and blood DNA, and identified a somatic, activating GNA14 mutation specific to the tumor. Our findings support aberrant GNA14 activation underlies the pathogenesis of TA associated with KMP.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA.,Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Carmen Fraile
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA.,Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Richard J Antaya
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA.,Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA.,Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
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10
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Affiliation(s)
- Ramrada Lekwuttikarn
- Division of Pediatric Dermatology, Department of Dermatology, Stanford University School of Medicine, Stanford, California.,Section of Dermatology, Division of Ambulatory and Adolescent Medicine, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Young H Lim
- Department of Dermatology, Yale School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale School of Medicine, New Haven, Connecticut
| | - Shehla Admani
- Division of Pediatric Dermatology, Department of Dermatology, Stanford University School of Medicine, Stanford, California
| | - Keith A Choate
- Department of Dermatology, Yale School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale School of Medicine, New Haven, Connecticut
| | - Joyce M C Teng
- Division of Pediatric Dermatology, Department of Dermatology, Stanford University School of Medicine, Stanford, California
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11
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Lee Y, Park HC, Shin JH, Lim YH, Park JK, Shin J, Kim KS, Kim BK. P5298Influence of the changes in body fat on all-cause and cardiovascular mortality in a general population: a report from Ansan-Ansung cohort in the Korean genome environment study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0269] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Paradoxical beneficial effects of obesity on all-cause and cardiovascular mortality have been reported in multiple cohort studies based on patients with cardiovascular disease as well as general populations. However, the association between the presence of obesity at baseline and the better survival rates could not be directly interpreted into the beneficial effect of gain in obesity or fatness on the mortality, which makes it difficult to provide any recommendation for the management of obesity. Therefore, we investigated the influence of the changes in body fat on all-cause and cardiovascular mortality in a general population.
Methods
A population-based cohort study has been conducted for 12 years (from 2001 to 2012). A total of 5,259 subjects in whom body compositions using a bio-impedance method were measured at least 2 times during the observational period were included. The causes of death was identified from the nation-wide database in KOSTAT. I20-I82 and R99 in the International Classification of Disease-10 codes were defined as a cardiovascular death. The subjects were evenly divided into 3 groups by the percentages of the changes in body fat (Δ%BF; decreased [Δ%BF <0.0%] vs. increased [Δ%BF 0.0–13.7%] vs. highly increased [Δ%BF ≥13.7%]). Inverse probability of treatment weighting was applied to balance the covariate differences among the groups.
Results
The age was 51.2±8.5 years and 51.6% was male. Median observation duration was 163 (the interquartile range: 157–168) months. The all-cause death and cardiovascular death occurred most frequently in the decreased Δ%BF group and least frequent in the highly increased Δ%BF group in both unweighted and weighted cohort. Multivariate Cox proportional hazard models showed that the risk of all-cause death was lower in the increased and highly increased Δ%BF groups (hazard ratio [HR] 0.61 [0.47–0.80] and 0.24 [0.17–0.34], respectively) and the risk of cardiovascular death was lower in the highly increased Δ%BF group (HR 0.20 [0.08–0.48]), compared to those in the decreased Δ%BF group after adjustment for all covariates including physical activities and the changes in muscle mass. The risk of all-cause death and cardiovascular death linearly decreased with increasing Δ%BF (HR 0.72 [0.67–0.77] and 0.70 [0.60–0.82], respectively).
Conclusion
The increase in body fat is associated with a lower risk of all-cause death and cardiovascular death in a middle-age general population, independently with physical activities and the changes in muscle mass.
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Affiliation(s)
- Y Lee
- Hanyang University Kuri Hospital, Department of cardiology, Guri, Korea (Republic of)
| | - H C Park
- Hanyang University Kuri Hospital, Department of cardiology, Guri, Korea (Republic of)
| | - J H Shin
- Hanyang University Kuri Hospital, Department of cardiology, Guri, Korea (Republic of)
| | - Y H Lim
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - J K Park
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - J Shin
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - K S Kim
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - B K Kim
- Sung Ae Hospital, Department of Cardiology, Seoul, Korea (Republic of)
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12
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Abstract
Abstract
Purpose
Patients with diabetes mellitus have an elevated risk of atrial fibrillation (AF). However, whether insulin resistance may elevate risk of AF incidence in non-diabetic is inconsistent. The aim of our study was to verify the association between insulin resistance and incidence of AF in non-diabetics.
Methods
We evaluated population-based cohorts embedded in the Korean Genome Epidemiology Study. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin resistance (HOMA-IR). Baseline data including HOMA-IR and electrocardiography (ECG) were obtained at 2001. Subsequent biennial ECG was performed for identification of AF until 2016.
Results
Among the 8220 participants (46.8% male; median age 49 years), 25 participants had AF (0.3%) at baseline and 101 participants developed AF (1.2%) during follow up of 12 years. In multivariate Cox regression analysis, high HOMA-IR (≥1.4) was significantly associated with incident AF compared with low HOMA-IR (<1.40) (adjusted hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.3–3.0). In subgroup analysis, these association was consistent regardless of obesity (BMI<25; adjust HR 1.8, 95% CI 1.1–3.0, BMI≥25; adjust HR 2.3, 95% CI 1.3–4.0)
Subgroup analysis
Conclusion
Based on prospective cohort study, insulin resistance (HOMA-IR) was associated with AF independently of obesity in non-diabetics.
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Affiliation(s)
- J K Park
- Hanyang University, Seoul, Korea (Republic of)
| | - J H Park
- Hanyang University, Seoul, Korea (Republic of)
| | - Y G Lee
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea (Republic of)
| | - J H Shin
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea (Republic of)
| | - Y H Lim
- Hanyang University, Seoul, Korea (Republic of)
| | - R Heo
- Hanyang University, Seoul, Korea (Republic of)
| | - J Shin
- Hanyang University, Seoul, Korea (Republic of)
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13
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Duchatelet S, Boyden LM, Ishida-Yamamoto A, Zhou J, Guibbal L, Hu R, Lim YH, Bole-Feysot C, Nitschké P, Santos-Simarro F, de Lucas R, Milstone LM, Gildenstern V, Helfrich YR, Attardi LD, Lifton RP, Choate KA, Hovnanian A. Mutations in PERP Cause Dominant and Recessive Keratoderma. J Invest Dermatol 2018; 139:380-390. [PMID: 30321533 DOI: 10.1016/j.jid.2018.08.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 01/06/2023]
Abstract
Investigation of genetic determinants of Mendelian skin disorders has substantially advanced understanding of epidermal biology. Here we show that mutations in PERP, encoding a crucial component of desmosomes, cause both dominant and recessive human keratoderma. Heterozygosity for a C-terminal truncation, which produces a protein that appears to be unstably incorporated into desmosomes, causes Olmsted syndrome with severe periorificial and palmoplantar keratoderma in multiple unrelated kindreds. Homozygosity for an N-terminal truncation ablates expression and causes widespread erythrokeratoderma, with expansion of epidermal differentiation markers. Both exhibit epidermal hyperproliferation, immature desmosomes lacking a dense midline observed via electron microscopy, and impaired intercellular adhesion upon mechanical stress. Localization of other desmosomal components appears normal, which is in contrast to other conditions caused by mutations in genes encoding desmosomal proteins. These discoveries highlight the essential role of PERP in human desmosomes and epidermal homeostasis and further expand the heterogeneous spectrum of inherited keratinization disorders.
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Affiliation(s)
- Sabine Duchatelet
- Laboratory of Genetic Skin Diseases, INSERM Imagine Institute, Paris, France; University Paris Descartes, Paris, France
| | - Lynn M Boyden
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Jing Zhou
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Laure Guibbal
- Laboratory of Genetic Skin Diseases, INSERM Imagine Institute, Paris, France; University Paris Descartes, Paris, France
| | - Ronghua Hu
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Young H Lim
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Christine Bole-Feysot
- University Paris Descartes, Paris, France; Genomic Platform, INSERM Imagine Institute, Paris, France
| | - Patrick Nitschké
- University Paris Descartes, Paris, France; Bioinformatics Platform, INSERM Imagine Institute, Paris, France
| | | | - Raul de Lucas
- Department of Dermatology, Hospital Universitario La Paz, Madrid, Spain
| | - Leonard M Milstone
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Yolanda R Helfrich
- Department of Dermatology, University of Michigan, Ann Arbor, Michigan, USA
| | - Laura D Attardi
- Departments of Radiation Oncology and Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Keith A Choate
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA.
| | - Alain Hovnanian
- Laboratory of Genetic Skin Diseases, INSERM Imagine Institute, Paris, France; University Paris Descartes, Paris, France; Department of Genetics, Necker-Enfants Malades Hospital, Paris, France.
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14
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Lim YH, Burke AB, Roberts MS, Collins MT, Choate KA. Multilineage ACTB mutation in a patient with fibro-osseous maxillary lesion and pilocytic astrocytoma. Am J Med Genet A 2018; 176:2037-2040. [PMID: 30152002 DOI: 10.1002/ajmg.a.40475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 01/17/2023]
Affiliation(s)
- Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Andrea B Burke
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland.,Division of Oral and Maxillofacial Surgery, School of Dentistry, University of Washington, Seattle, Washington
| | - Mary S Roberts
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Michael T Collins
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
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15
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Park JK, Choi YW, Kim BS, Chang KS, Lee YG, Shin JH, Lim YH, Park HC, Shin J. P1880Independent effect of physical activity and resting heart rate on incidence of atrial fibrillation in general population. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J K Park
- Hanyang University, Seoul, Korea Republic of
| | - Y W Choi
- Hanyang University, Seoul, Korea Republic of
| | - B S Kim
- Hanyang University, Seoul, Korea Republic of
| | - K S Chang
- Hanyang University, Seoul, Korea Republic of
| | - Y G Lee
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea Republic of
| | - J H Shin
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea Republic of
| | - Y H Lim
- Hanyang University, Seoul, Korea Republic of
| | - H C Park
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea Republic of
| | - J Shin
- Hanyang University, Seoul, Korea Republic of
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16
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Lee Y, Park JK, Lim YH, Shin JH, Park HC, Shin J, Kim KS. 5047C-reactive protein and the risk of atrial fibrillation: KOGES 12 years' follow-up study. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.5047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Y Lee
- Hanyang University, Seoul, Korea Republic of
| | - J K Park
- Hanyang University, Seoul, Korea Republic of
| | - Y H Lim
- Hanyang University, Seoul, Korea Republic of
| | - J H Shin
- Hanyang University, Seoul, Korea Republic of
| | - H C Park
- Hanyang University, Seoul, Korea Republic of
| | - J Shin
- Hanyang University, Seoul, Korea Republic of
| | - K S Kim
- Hanyang University, Seoul, Korea Republic of
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17
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Abstract
Genetic mosaicism arises when a zygote harbors two or more distinct genotypes, typically due to de novo, somatic mutation during embryogenesis. The clinical manifestations largely depend on the differentiation status of the mutated cell; earlier mutations target pluripotent cells and generate more widespread disease affecting multiple organ systems. If gonadal tissue is spared-as in somatic genomic mosaicism-the mutation and its effects are limited to the proband, whereas mosaicism also affecting the gametes, such as germline or gonosomal mosaicism, is transmissible. Mosaicism is easily appreciated in cutaneous disorders, as phenotypically distinct mutant cells often give rise to lesions in patterns determined by the affected cell type. Genetic investigation of cutaneous mosaic disorders has identified pathways central to disease pathogenesis, revealing novel therapeutic targets. In this review, we discuss examples of cutaneous mosaicism, approaches to gene discovery in these disorders, and insights into molecular pathobiology that have potential for clinical translation.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut 06520, USA; .,Departments of Pathology and Genetics, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Zoe Moscato
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut 06520, USA;
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut 06520, USA; .,Departments of Pathology and Genetics, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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18
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Yeo WL, Chew X, Smith DJ, Chan KP, Sun H, Zhao H, Lim YH, Ang EL. Probing the molecular determinants of fluorinase specificity. Chem Commun (Camb) 2018; 53:2559-2562. [PMID: 28184383 DOI: 10.1039/c6cc09213f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular determinants of FlA1 fluorinase specificity were probed using 5'-chloro-5'-deoxyadenosine (5'-ClDA) analogs as substrates and FlA1 active site mutants. Modifications at F213 or A279 residues are beneficial towards these modified substrates, including 5'-chloro-5'-deoxy-2-ethynyladenosine, ClDEA (>10-fold activity improvement), and conferred novel activity towards substrates not readily accepted by wild-type FlA1.
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Affiliation(s)
- W L Yeo
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669.
| | - X Chew
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore 138665.
| | - D J Smith
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore 138671 and Biotransformation Innovation Platform, A*STAR, 61 Biopolis Drive, Proteos #04-14, Singapore 138673
| | - K P Chan
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore 138665.
| | - H Sun
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669.
| | - H Zhao
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669. and 215 Roger Adams Laboratory, Box C3, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue Urbana, IL 61801, USA
| | - Y H Lim
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore 138665.
| | - E L Ang
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669.
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19
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Abstract
Background Injury is the commonest cause of morbidity and mortality amongst the younger age groups. Management of injuries has been identified as one of the major health issues facing our community. The study objective was to define the epidemiology of injury related deaths in Singapore. Methods A nationwide review of all deaths arising as a result of injury in 1995 was conducted. Results There were 913 cases with an injury mortality rate of 27 per 100,000 population. Ninety-seven percent (97%) were due to blunt injury. Falls from heights from deliberate self-harm was the commonest mechanism, followed by motor vehicle collisions (MVC). Fifty-two percent (52%) of MVC deaths were motorcyclists or pillion riders. Sixty-six percent (66%) of all deaths occurred in the prehospital phase. Central nervous system injury was the main cause of hospital deaths. Conclusion Results from this study will help our community focus on the appropriate preventive strategies to reduce mortality and the cost of injuries to our society.
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Affiliation(s)
- MKF Leong
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - S Mujumdar
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - L Raman
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - YH Lim
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - TC Chao
- Institute of Forensic Medicine
| | - V Anantharaman
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
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20
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Lim YH, Hendricks J. A Case of Nonfatal Non-Collapsed Patient with Extreme Hyperkalaemia. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790701400407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This is a report of a non-collapsed patient with nonfatal, extreme hyperkalaemia of 10.7 mmol/L. The patient's hyperkalaemia was initially treated in the Emergency Department and then transferred to the Department of Renal Medicine of another hospital for further stabilisation. There have only been a few reported cases of successful management of extreme hyperkalaemia in excess of 10.0 mmol/L.
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21
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Lim YH, Yeo A, Koh MP, Wong CY. Severely Injured Patients Presenting to the Singapore General Hospital: a one Year Study. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790301000104] [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] Open
Abstract
Study objectives To determine the quantity and resource utilisation in management of the severely injured patients presenting at the Singapore General Hospital (SGH). Method All patients who were initially triaged to the hospital Emergency Department's (ED) resuscitation room and all trauma related mortality in the year 1998 were studied. All records were traced and the cases were followed up. Important outcomes studied were mortality and length of hospital stay. Results Three hundred and forty-seven (0.2%) severely injured patients who were initially treated at the ED's resuscitation room were studied. The median age of the patients was 32 years old. Male patients formed 82.1% of the total. The three main causes of trauma in such patients were fall from height, motor vehicle related accidents and penetrating injuries caused by sharp instruments and firearms. Of all the patients, 62.8% were admitted to the ED between 1601 hours to 0759 hours and 30.5% of all severely injured patients were treated at the ED on weekends. One hundred and twenty three (35.4%) patients had emergency surgery within 24 hours of admission to the ED and 42.4% of the patients had an ISS score of 16 or more; 22.8% of patients had ISS score of 25 or more. The mortality of patients with ISS score of 25 or more was 39.2%. Conclusion One percent of all new ED patients with trauma were classified as ‘severely’ injured and these occurred mostly outside “normal working hours”. There was significant mortality in patients with ISS score of 25 or more.
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Affiliation(s)
| | - A Yeo
- Singapore General Hospital, Department of General Surgery and Trauma Service
| | - MP Koh
- Singapore General Hospital, Department of General Surgery
| | - CY Wong
- Singapore General Hospital, Department of General Surgery
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22
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Lim YH, Anantharaman V. Patients who Self-Discharge from the Emergency Department: a Three-Month Telephone Survey. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790401100105] [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] Open
Abstract
Study objectives To determine the main causes and outcomes of patients who self-discharged from the Emergency Department (ED). Methods Records of all patients who self-discharged from the ED of a tertiary level hospital were traced and telephone interviews were conducted. The duration of the study was from 15 July 2002 to 14 October 2002. Results There were 28,898 new attendances during the period of study and of these, 450 (1.6%) patients signed the self-discharge form. Of the 357 patients recruited into the study, the majority signed the self-discharge form because of refusal of admission to inpatient units (52.1%) or the ED observation ward (43.4%) for further treatment. One hundred and thirteen (31.7%) patients acknowledged that they were unwell during the interview and 85 (23.8%) patients sought some form of medical attention after leaving the ED. Conclusion Most of the patients who self-discharged from the ED were for personal reasons and very few were due to financial reasons.
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Affiliation(s)
- YH Lim
- Singapore General Hospital, Department of Emergency Medicine, Singapore 169608
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23
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Abstract
This is a rare case of sagittal sinus thrombosis occurring in the first trimester of pregnancy. A literature review was performed.
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24
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Abstract
Ichthyosis with confetti is a rare, autosomal dominant disorder caused by frameshift mutations in KRT10 or KRT1 and characterized by the development of white, genetically revertant macules in red, diseased skin. All cases result from mutations affecting the tail domains of keratin-10 or keratin-1, and Suzuki et al. expand the mutation spectrum for ichthyosis with confetti caused by mutations in KRT1, showing that a polyarginine frameshift in the keratin-1 tail can also cause this disorder.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA.
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25
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Lonnecker AT, Lim YH, Wooley KL. Functional Polycarbonate of a d-Glucal-Derived Bicyclic Carbonate via Organocatalytic Ring-Opening Polymerization. ACS Macro Lett 2017; 6:748-753. [PMID: 35650856 DOI: 10.1021/acsmacrolett.7b00362] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Herein, we demonstrate the synthesis of a bicyclic carbonate monomer of a d-glucal derivative, which originated from the natural product d-glucose, in an efficient three-step procedure and its ring-opening polymerization (ROP), initiated by 4-methylbenzyl alcohol, via organocatalysis. The ROP behavior was studied as a function of time, catalyst type, and catalyst concentration by using size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) spectroscopy. Using a cocatalyst system of 1,8-diazabicyclo[5.4.0]undec-7-ene and 1-(3,5-bis(trifluoromethyl)phenyl)-3-cyclohexyl-2-thiourea (5 mol %) afforded poly(d-glucal-carbonate) (PGCC) with almost complete monomer conversion (ca. 99%) within 1 min, as analyzed by 1H NMR spectroscopy, and a monomodal SEC trace with dispersity of 1.13. The resulting PGCCs exhibited amorphous characteristics with a relatively high glass transition temperature at ca. 69 °C and onset decomposition temperature at ca. 190 °C, as analyzed by differential scanning calorimetry and thermogravimetric analysis, respectively. This new type of potentially degradable polymer system represents a reactive functional polymer architecture.
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Affiliation(s)
- Alexander T. Lonnecker
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic−Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
| | - Young H. Lim
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic−Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
| | - Karen L. Wooley
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic−Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
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26
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Lim YH, Ovejero D, Derrick KM, Collins MT, Choate KA. Cutaneous skeletal hypophosphatemia syndrome (CSHS) is a multilineage somatic mosaic RASopathy. J Am Acad Dermatol 2017; 75:420-7. [PMID: 27444071 DOI: 10.1016/j.jaad.2015.11.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [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] [Received: 07/10/2015] [Revised: 10/24/2015] [Accepted: 11/09/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND We recently demonstrated multilineage somatic mosaicism in cutaneous skeletal hypophosphatemia syndrome (CSHS), which features epidermal or melanocytic nevi, elevated fibroblast growth factor (FGF)-23, and hypophosphatemia, finding identical RAS mutations in affected skin and bone. OBJECTIVE We sought to: (1) provide an updated overview of CSHS; (2) review its pathobiology; (3) present a new patient with CSHS; and (4) discuss treatment modalities. METHODS We searched PubMed for "nevus AND rickets," and "nevus AND hypophosphatemia," identifying cases of nevi with hypophosphatemic rickets or elevated serum FGF-23. For our additional patient with CSHS, we performed histopathologic and radiographic surveys of skin and skeletal lesions, respectively. Sequencing was performed for HRAS, KRAS, and NRAS to determine causative mutations. RESULTS Our new case harbored somatic activating HRAS p.G13 R mutation in affected tissue, consistent with previous findings. Although the mechanism of FGF-23 dysregulation is unknown in CSHS, interaction between FGF and MAPK pathways may provide insight into pathobiology. Anti-FGF-23 antibody KRN-23 may be useful in managing CSHS. LIMITATIONS Multilineage RAS mutation in CSHS was recently identified; further studies on mechanism are unavailable. CONCLUSION Patients with nevi in association with skeletal disease should be evaluated for serum phosphate and FGF-23. Further studies investigating the role of RAS in FGF-23 regulation are needed.
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Affiliation(s)
- Young H Lim
- Departments of Dermatology, Pathology, and Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Diana Ovejero
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland; Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Kristina M Derrick
- Division of Pediatric Endocrinology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York
| | - Michael T Collins
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Keith A Choate
- Departments of Dermatology, Pathology, and Genetics, Yale University School of Medicine, New Haven, Connecticut.
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27
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Ovejero D, Lim YH, Boyce AM, Gafni RI, McCarthy E, Nguyen TA, Eichenfield LF, DeKlotz CMC, Guthrie LC, Tosi LL, Thornton PS, Choate KA, Collins MT. Cutaneous skeletal hypophosphatemia syndrome: clinical spectrum, natural history, and treatment. Osteoporos Int 2016; 27:3615-3626. [PMID: 27497815 PMCID: PMC6908308 DOI: 10.1007/s00198-016-3702-8] [Citation(s) in RCA: 34] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 07/06/2016] [Indexed: 12/01/2022]
Abstract
UNLABELLED Cutaneous skeletal hypophosphatemia syndrome (CSHS), caused by somatic RAS mutations, features excess fibroblast growth factor-23 (FGF23) and skeletal dysplasia. Records from 56 individuals were reviewed and demonstrated fractures, scoliosis, and non-congenital hypophosphatemia that in some cases were resolved. Phosphate and calcitriol, but not skin lesion removal, were effective at controlling hypophosphatemia. No skeletal malignancies were found. PURPOSE CSHS is a disorder defined by the association of epidermal and/or melanocytic nevi, a mosaic skeletal dysplasia, and an FGF23-mediated hypophosphatemia. To date, somatic RAS mutations have been identified in all patients whose affected tissue has undergone DNA sequencing. However, the clinical spectrum and treatment are poorly defined in CSHS. The purpose of this study is to determine the spectrum of the phenotype, natural history of the disease, and response to treatment of hypophosphatemia. METHODS Five CSHS subjects underwent prospective data collection at clinical research centers. A review of the literature identified 45 reports that included a total of 51 additional patients, in whom the findings were compatible with CSHS. Data on nevi subtypes, bone histology, mineral and skeletal disorders, abnormalities in other tissues, and response to treatment of hypophosphatemia were analyzed. RESULTS Fractures, limb deformities, and scoliosis affected most CSHS subjects. Hypophosphatemia was not present at birth. Histology revealed severe osteomalacia but no other abnormalities. Skeletal dysplasia was reported in all anatomical compartments, though less frequently in the spine; there was no clear correlation between the location of nevi and the skeletal lesions. Phosphate and calcitriol supplementation was the most effective therapy for rickets. Convincing data that nevi removal improved blood phosphate levels was lacking. An age-dependent improvement in mineral abnormalities was observed. A spectrum of extra-osseous/extra-cutaneous manifestations that included both benign and malignant neoplasms was present in many subjects, though osteosarcoma remains unreported. CONCLUSION An understanding of the spectrum, natural history, and efficacy of treatment of hypophosphatemia in CSHS may improve the care of these patients.
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Affiliation(s)
- D Ovejero
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
- Departament de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Y H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA
| | - A M Boyce
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
| | - R I Gafni
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
| | - E McCarthy
- Department of Pathology, The Johns Hopkins University, Baltimore, MD, USA
| | - T A Nguyen
- Albert Einstein College of Medicine, Bronx, NY, USA
- Departments of Dermatology and Pediatrics, San Diego and Rady Children's Hospital, University of California, San Diego, CA, USA
| | - L F Eichenfield
- Departments of Dermatology and Pediatrics, San Diego and Rady Children's Hospital, University of California, San Diego, CA, USA
| | - C M C DeKlotz
- Division Dermatology, Department of Medicine and Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - L C Guthrie
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
| | - L L Tosi
- Bone Health Program, Division of Orthopaedics and Sports Medicine, Children's National Health System, Washington, DC, USA
| | - P S Thornton
- Department of Endocrinology and Diabetes, Cook Children Medical Center, Fort Worth, TX, USA
| | - K A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA
| | - M T Collins
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA.
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Lim YH, Tiemann KM, Hunstad DA, Elsabahy M, Wooley KL. Polymeric nanoparticles in development for treatment of pulmonary infectious diseases. Wiley Interdiscip Rev Nanomed Nanobiotechnol 2016; 8:842-871. [PMID: 27016134 PMCID: PMC5035710 DOI: 10.1002/wnan.1401] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 02/08/2016] [Accepted: 02/15/2016] [Indexed: 12/17/2022]
Abstract
Serious lung infections, such as pneumonia, tuberculosis, and chronic obstructive cystic fibrosis-related bacterial diseases, are increasingly difficult to treat and can be life-threatening. Over the last decades, an array of therapeutics and/or diagnostics have been exploited for management of pulmonary infections, but the advent of drug-resistant bacteria and the adverse conditions experienced upon reaching the lung environment urge the development of more effective delivery vehicles. Nanotechnology is revolutionizing the approach to circumventing these barriers, enabling better management of pulmonary infectious diseases. In particular, polymeric nanoparticle-based therapeutics have emerged as promising candidates, allowing for programmed design of multi-functional nanodevices and, subsequently, improved pharmacokinetics and therapeutic efficiency, as compared to conventional routes of delivery. Direct delivery to the lungs of such nanoparticles, loaded with appropriate antimicrobials and equipped with 'smart' features to overcome various mucosal and cellular barriers, is a promising approach to localize and concentrate therapeutics at the site of infection while minimizing systemic exposure to the therapeutic agents. The present review focuses on recent progress (2005-2015) important for the rational design of nanostructures, particularly polymeric nanoparticles, for the treatment of pulmonary infections with highlights on the influences of size, shape, composition, and surface characteristics of antimicrobial-bearing polymeric nanoparticles on their biodistribution, therapeutic efficacy, and toxicity. WIREs Nanomed Nanobiotechnol 2016, 8:842-871. doi: 10.1002/wnan.1401 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Young H Lim
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science & Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, TX, USA
| | - Kristin M Tiemann
- Department of Pediatrics, Washington University of School of Medicine, St. Louis, MO, USA
| | - David A Hunstad
- Department of Pediatrics, Washington University of School of Medicine, St. Louis, MO, USA
- Department of Molecular Microbiology, Washington University of School of Medicine, St. Louis, MO, USA
| | - Mahmoud Elsabahy
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science & Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, TX, USA.
- Department of Pharmaceutics, Faculty of Pharmacy, Assiut International Center of Nanomedicine, Al-Rajhy Liver Hospital, Assiut University, Assiut, Egypt.
- Misr University for Science and Technology, 6th of October City, Egypt.
| | - Karen L Wooley
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science & Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, TX, USA.
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Affiliation(s)
- Alexander T. Lonnecker
- Departments of Chemistry, Chemical Engineering, and Materials Science & Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
| | - Young H. Lim
- Departments of Chemistry, Chemical Engineering, and Materials Science & Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
| | - Simcha E. Felder
- Departments of Chemistry, Chemical Engineering, and Materials Science & Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
| | - Céline J. Besset
- Departments of Chemistry, Chemical Engineering, and Materials Science & Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
| | - Karen L. Wooley
- Departments of Chemistry, Chemical Engineering, and Materials Science & Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842, United States
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Lim YH, Bacchiocchi A, Qiu J, Straub R, Bruckner A, Bercovitch L, Narayan D, McNiff J, Ko C, Robinson-Bostom L, Antaya R, Halaban R, Choate KA. GNA14 Somatic Mutation Causes Congenital and Sporadic Vascular Tumors by MAPK Activation. Am J Hum Genet 2016; 99:443-50. [PMID: 27476652 PMCID: PMC4974082 DOI: 10.1016/j.ajhg.2016.06.010] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [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: 05/23/2016] [Accepted: 06/13/2016] [Indexed: 12/20/2022] Open
Abstract
Vascular tumors are among the most common neoplasms in infants and children; 5%-10% of newborns present with or develop lesions within the first 3 months of life. Most are benign infantile hemangiomas that typically regress by 5 years of age; other vascular tumors include congenital tufted angiomas (TAs), kaposiform hemangioendotheliomas (KHEs), and childhood lobular capillary hemangiomas (LCHs). Some of these lesions can become locally invasive and unresponsive to pharmacologic intervention, leading to significant complications. Recent investigation has revealed that activating mutations in HRAS, KRAS, NRAS, GNAQ, and GNA11 can cause certain types of rare childhood vascular tumors, and we have now identified causal recurrent somatic activating mutations in GNA14 by whole-exome and targeted sequencing. We found somatic activating GNA14 c.614A>T (p.Gln205Leu) mutations in one KHE, one TA, and one LCH and a GNA11 c.547C>T (p.Arg183Cys) mutation in two LCH lesions. We examined mutation pathobiology via expression of mutant GNA14 or GNA11 in primary human endothelial cells and melanocytes. GNA14 and GNA11 mutations induced changes in cellular morphology and rendered cells growth-factor independent by upregulating the MAPK pathway. Our findings identify GNA14 mutations as a cause of childhood vascular tumors, offer insight into mechanisms of oncogenic transformation by mutations affecting Gaq family members, and identify potential targets for therapeutic intervention.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Pathology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Genetics, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Antonella Bacchiocchi
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Jingyao Qiu
- Department of Genetics, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Robert Straub
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Anna Bruckner
- Departments of Dermatology and Pediatrics, School of Medicine, University of Colorado, Aurora, CO 80045, USA
| | - Lionel Bercovitch
- Department of Dermatology, Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Deepak Narayan
- Section of Plastic Surgery, Department of Surgery, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Jennifer McNiff
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Pathology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Christine Ko
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Pathology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Leslie Robinson-Bostom
- Department of Dermatology, Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Richard Antaya
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Pediatrics, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Ruth Halaban
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Keith A Choate
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Pathology, School of Medicine, Yale University, New Haven, CT 06510, USA; Department of Genetics, School of Medicine, Yale University, New Haven, CT 06510, USA.
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Lim YH, Fisher JM, Bosenberg MW, Choate KA, Ko CJ. Keratoacanthoma Shares Driver Mutations with Cutaneous Squamous Cell Carcinoma. J Invest Dermatol 2016; 136:1737-1741. [DOI: 10.1016/j.jid.2016.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 03/28/2016] [Accepted: 04/06/2016] [Indexed: 12/28/2022]
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Abstract
IMPORTANCE Inhibition of angiogenesis is an effective anticancer strategy because neoplasms require a rich blood supply. Ramucirumab, approved by the US Food and Drug Administration in 2014 to treat gastric adenocarcinomas and non-small cell lung carcinomas, targets vascular endothelial growth factor 2 (VEGFR2). We identified a patient prescribed a regimen of irinotecan hydrochloride, cetuximab, and ramucirumab for metastatic rectal cancer (diagnosed in November 2013 and treated through early January 2015) who developed a new-onset, expanding vascular lesion on his right leg. Via exome sequencing, we found that the lesion contained a single somatic mutation in KDR (encodes VEGFR2), possibly in response to ramucirumab. Vascular tumors are not a known complication of antiangiogenic therapeutics. OBSERVATIONS Exome sequencing of the well-demarcated, blanching vascular lesion on the lateral right shin revealed a somatic p.T771R mutation in KDR, without evidence of other somatic mutations or loss of heterozygosity. Histological features included lobules of small vessels within the dermis, resembling a tufted angioma. CONCLUSIONS AND RELEVANCE A potential adverse effect of ramucirumab in combination therapy is the development of sporadic angiomas. The p.T771R mutation was previously implicated in autophosphorylation of VEGFR2 and reported in angiosarcomas alongside other driver mutations. Our observations suggest that this mutation confers a proliferative advantage in the setting of ramucirumab therapy. Patients receiving ramucirumab should be monitored for the development of new vascular lesions.
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Affiliation(s)
- Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut2Department of Pathology, Yale University School of Medicine, New Haven, Connecticut3Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Ian D Odell
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Christine J Ko
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut2Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut2Department of Pathology, Yale University School of Medicine, New Haven, Connecticut3Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
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Lim YH, Tiemann KM, Heo GS, Wagers PO, Rezenom YH, Zhang S, Zhang F, Youngs WJ, Hunstad DA, Wooley KL. Preparation and in vitro antimicrobial activity of silver-bearing degradable polymeric nanoparticles of polyphosphoester-block-poly(L-lactide). ACS Nano 2015; 9:1995-2008. [PMID: 25621868 PMCID: PMC4455953 DOI: 10.1021/nn507046h] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [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: 05/18/2023]
Abstract
The development of well-defined polymeric nanoparticles (NPs) as delivery carriers for antimicrobials targeting human infectious diseases requires rational design of the polymer template, an efficient synthetic approach, and fundamental understanding of the developed NPs, e.g., drug loading/release, particle stability, and other characteristics. Herein, we developed and evaluated the in vitro antimicrobial activity of silver-bearing, fully biodegradable and functional polymeric NPs. A series of degradable polymeric nanoparticles (dNPs), composed of phosphoester and L-lactide and designed specifically for silver loading into the hydrophilic shell and/or the hydrophobic core, were prepared as potential delivery carriers for three different types of silver-based antimicrobials-silver acetate or one of two silver carbene complexes (SCCs). Silver-loading capacities of the dNPs were not influenced by the hydrophilic block chain length, loading site (i.e., core or shell), or type of silver compound, but optimization of the silver feed ratio was crucial to maximize the silver loading capacity of dNPs, up to ca. 12% (w/w). The release kinetics of silver-bearing dNPs revealed 50% release at ca. 2.5-5.5 h depending on the type of silver compound. In addition, we undertook a comprehensive evaluation of the rates of hydrolytic or enzymatic degradability and performed structural characterization of the degradation products. Interestingly, packaging of the SCCs in the dNP-based delivery system improved minimum inhibitory concentrations up to 70%, compared with the SCCs alone, as measured in vitro against 10 contemporary epidemic strains of Staphylococcus aureus and eight uropathogenic strains of Escherichia coli. We conclude that these dNP-based delivery systems may be beneficial for direct epithelial treatment and/or prevention of ubiquitous bacterial infections, including those of the skin and urinary tract.
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Affiliation(s)
- Young H. Lim
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842, United States
| | - Kristin M. Tiemann
- Department of Pediatrics, Washington University of School of Medicine, St. Louis, MO 63110, United States
| | - Gyu Seong Heo
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842, United States
| | - Patrick O. Wagers
- Department of Chemistry and Center for Silver Therapeutics Research, University of Akron, Akron, OH 44325, United States
| | - Yohannes H. Rezenom
- Laboratory for Biological Mass Spectrometry, Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Shiyi Zhang
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842, United States
| | - Fuwu Zhang
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842, United States
| | - Wiley J. Youngs
- Department of Chemistry and Center for Silver Therapeutics Research, University of Akron, Akron, OH 44325, United States
| | - David A. Hunstad
- Department of Pediatrics, Washington University of School of Medicine, St. Louis, MO 63110, United States
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Karen L. Wooley
- Departments of Chemistry, Chemical Engineering, and Materials Science and Engineering, and Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842, United States
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Lim YH, Douglas SR, Ko CJ, Antaya RJ, McNiff JM, Zhou J, Choate KA, Narayan D. Somatic Activating RAS Mutations Cause Vascular Tumors Including Pyogenic Granuloma. J Invest Dermatol 2015; 135:1698-1700. [PMID: 25695684 PMCID: PMC4430357 DOI: 10.1038/jid.2015.55] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Young H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Stephanie R Douglas
- Section of Plastic Surgery, Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Christine J Ko
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Richard J Antaya
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jennifer M McNiff
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jing Zhou
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Keith A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA.
| | - Deepak Narayan
- Section of Plastic Surgery, Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, USA
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Gustafson TP, Lim YH, Flores JA, Heo GS, Zhang F, Zhang S, Samarajeewa S, Raymond JE, Wooley KL. Holistic assessment of covalently labeled core-shell polymeric nanoparticles with fluorescent contrast agents for theranostic applications. Langmuir 2014; 30:631-41. [PMID: 24392760 PMCID: PMC3933954 DOI: 10.1021/la403943w] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The successful development of degradable polymeric nanostructures as optical probes for use in nanotheranostic applications requires the intelligent design of materials such that their surface response, degradation, drug delivery, and imaging properties are all optimized. In the case of imaging, optimization must result in materials that allow differentiation between unbound optical contrast agents and labeled polymeric materials as they undergo degradation. In this study, we have shown that use of traditional electrophoretic gel-plate assays for the determination of the purity of dye-conjugated degradable nanoparticles is limited by polymer degradation characteristics. To overcome these limitations, we have outlined a holistic approach to evaluating dye and peptide-polymer nanoparticle conjugation by utilizing steady-state fluorescence, anisotropy, and emission and anisotropy lifetime decay profiles, through which nanoparticle-dye binding can be assessed independently of perturbations, such as those presented during the execution of electrolyte gel-based assays. This approach has been demonstrated to provide an overall understanding of the spectral signature-structure-function relationship, ascertaining key information on interactions between the fluorophore, polymer, and solvent components that have a direct and measurable impact on the emissive properties of the optical probe. The use of these powerful techniques provides feedback that can be utilized to improve nanotheranostics by evaluating dye emissivity in degradable nanotheranostic systems, which has become increasingly important as modern platforms transition to architectures intentionally reliant on degradation and built-in environmental responses.
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Affiliation(s)
| | | | | | | | | | | | | | - Jeffery E. Raymond
- Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Karen L. Wooley
- Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
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Elsabahy M, Zhang S, Zhang F, Deng ZJ, Lim YH, Wang H, Parsamian P, Hammond PT, Wooley KL. Surface charges and shell crosslinks each play significant roles in mediating degradation, biofouling, cytotoxicity and immunotoxicity for polyphosphoester-based nanoparticles. Sci Rep 2013; 3:3313. [PMID: 24264796 PMCID: PMC3837308 DOI: 10.1038/srep03313] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 11/06/2013] [Indexed: 01/12/2023] Open
Abstract
The construction of nanostructures from biodegradable precursors and shell/core crosslinking have been pursued as strategies to solve the problems of toxicity and limited stability, respectively. Polyphosphoester (PPE)-based micelles and crosslinked nanoparticles with non-ionic, anionic, cationic, and zwitterionic surface characteristics for potential packaging and delivery of therapeutic and diagnostic agents, were constructed using a quick and efficient synthetic strategy, and importantly, demonstrated remarkable differences in terms of cytotoxicity, immunotoxicity, and biofouling properties, as a function of their surface characteristics and also with dependence on crosslinking throughout the shell layers. For instance, crosslinking of zwitterionic micelles significantly reduced the immunotoxicity, as evidenced from the absence of secretions of any of the 23 measured cytokines from RAW 264.7 mouse macrophages treated with the nanoparticles. The micelles and their crosslinked analogs demonstrated lower cytotoxicity than several commercially-available vehicles, and their degradation products were not cytotoxic to cells at the range of the tested concentrations. PPE-nanoparticles are expected to have broad implications in clinical nanomedicine as alternative vehicles to those involved in several of the currently available medications.
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Affiliation(s)
- Mahmoud Elsabahy
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
- Department of Pharmaceutics, Faculty of Pharmacy, Assiut Clinical Center of Nanomedicine, Al-Rajhy Liver Hospital, Assiut University, Assiut, Egypt
- These authors contributed equally to this work
| | - Shiyi Zhang
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
- David H. Koch Institute for Integrative, Cancer Research, Cambridge, MA 02139
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- These authors contributed equally to this work
| | - Fuwu Zhang
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
| | - Zhou J. Deng
- David H. Koch Institute for Integrative, Cancer Research, Cambridge, MA 02139
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Young H. Lim
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
| | - Hai Wang
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
| | - Perouza Parsamian
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
| | - Paula T. Hammond
- David H. Koch Institute for Integrative, Cancer Research, Cambridge, MA 02139
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Karen L. Wooley
- Department of Chemistry, Department of Chemical Engineering, Laboratory for Synthetic-Biologic Interactions, Texas A&M University, P.O. Box 30012, 3255 TAMU, College Station, Texas 77842-3012, United States
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Lim YH, Ovejero D, Sugarman JS, Deklotz CMC, Maruri A, Eichenfield LF, Kelley PK, Jüppner H, Gottschalk M, Tifft CJ, Gafni RI, Boyce AM, Cowen EW, Bhattacharyya N, Guthrie LC, Gahl WA, Golas G, Loring EC, Overton JD, Mane SM, Lifton RP, Levy ML, Collins MT, Choate KA. Multilineage somatic activating mutations in HRAS and NRAS cause mosaic cutaneous and skeletal lesions, elevated FGF23 and hypophosphatemia. Hum Mol Genet 2013; 23:397-407. [PMID: 24006476 DOI: 10.1093/hmg/ddt429] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pathologically elevated serum levels of fibroblast growth factor-23 (FGF23), a bone-derived hormone that regulates phosphorus homeostasis, result in renal phosphate wasting and lead to rickets or osteomalacia. Rarely, elevated serum FGF23 levels are found in association with mosaic cutaneous disorders that affect large proportions of the skin and appear in patterns corresponding to the migration of ectodermal progenitors. The cause and source of elevated serum FGF23 is unknown. In those conditions, such as epidermal and large congenital melanocytic nevi, skin lesions are variably associated with other abnormalities in the eye, brain and vasculature. The wide distribution of involved tissues and the appearance of multiple segmental skin and bone lesions suggest that these conditions result from early embryonic somatic mutations. We report five such cases with elevated serum FGF23 and bone lesions, four with large epidermal nevi and one with a giant congenital melanocytic nevus. Exome sequencing of blood and affected skin tissue identified somatic activating mutations of HRAS or NRAS in each case without recurrent secondary mutation, and we further found that the same mutation is present in dysplastic bone. Our finding of somatic activating RAS mutation in bone, the endogenous source of FGF23, provides the first evidence that elevated serum FGF23 levels, hypophosphatemia and osteomalacia are associated with pathologic Ras activation and may provide insight in the heretofore limited understanding of the regulation of FGF23.
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Lim YH, Heo GS, Cho S, Wooley KL. Construction of a Reactive Diblock Copolymer, Polyphosphoester- block-Poly(L-lactide), as a Versatile Framework for Functional Materials that are Capable of Full Degradation and Nanoscopic Assembly Formation. ACS Macro Lett 2013; 2:10.1021/mz400229m. [PMID: 24167757 PMCID: PMC3808001 DOI: 10.1021/mz400229m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The development of a diblock copolymer, polyphosphoester-block-poly(L-lactide), which has potential for being fully-degradable and biocompatible, was achieved by one-pot sequential ring-opening polymerizations (ROPs) of two cyclic monomers: alkyne-functionalized phospholane and L-lactide (LLA). A kinetic study of the polymerization in each step was investigated in a detailed manner by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC), revealing living/controlled characteristics with narrow molecular weight distributions and a linear increase of molecular weights vs. monomer conversion and time. Subsequently, photo-induced thiol-yne "click" reactions with small molecule thiols bearing either carboxylic acid or amino groups afforded amphiphilic diblock copolymers with carboxylate or amino side-chain functionalities along the polyphosphoester segment of the diblock copolymer backbone. Finally, direct dissolution of the two different types of amphiphilic diblock copolymers in aqueous solutions yielded well-defined spherical micelles with corresponding negative or positive surface charges, respectively, as confirmed by transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential analyses.
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Affiliation(s)
- Young H. Lim
- Departments of Chemistry and Chemical Engineering, Texas A&M University, College Station, Texas 77842, United States
| | - Gyu Seong Heo
- Departments of Chemistry and Chemical Engineering, Texas A&M University, College Station, Texas 77842, United States
| | - Sangho Cho
- Departments of Chemistry and Chemical Engineering, Texas A&M University, College Station, Texas 77842, United States
| | - Karen L. Wooley
- Departments of Chemistry and Chemical Engineering, Texas A&M University, College Station, Texas 77842, United States
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Gilbert EA, Lim YH, Vickaryous MK, Armstrong CL. Heterochronic protein expression patterns in the developing embryonic chick cerebellum. Anat Rec (Hoboken) 2012; 295:1669-82. [PMID: 22865685 DOI: 10.1002/ar.22544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/12/2012] [Accepted: 07/11/2012] [Indexed: 12/18/2022]
Abstract
The advantages of the embryonic chick as a model for studying neural development range from the relatively low cost of fertilized eggs to the rapid rate of development. We investigated in ovo cerebellar development in the chick, which has a nearly identical embryonic period as the mouse (19-22 days). We focused on three antigens: Calbindin (CB), Zebrin II (ZII), and Calretinin (CR), and our results demonstrate asynchronous expression patterns during cerebellar development. Presumptive CB+ Purkinje cells are first observed at embryonic day (E)10 in clusters in posterior cerebellum. At E12, corresponding with global expression of CB across the cerebellum, Purkinje cells began to express ZII. By E14-E16, Purkinje cells disperse into a monolayer and develop a pattern of alternating immunopositive and immunonegative ZII stripes. CR is initially expressed by clusters of presumptive Purkinje cells in the nodular zone at E8. However, this expression is transient and at later stages, CR is largely confined to the granule and molecular layers. Before hatch (E18-E20), Purkinje cells adopt a morphologically mature phenotype with complex dendritic arborizations. Comparing this data to that seen in mice, we found that the sequence of Purkinje cell formation, protein expression, and development is similar in both species, but these events consistently begin ∼5-7 days earlier in the precocial chick cerebellum, suggesting an important role for heterochrony in neurodevelopment.
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Affiliation(s)
- E A Gilbert
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario, Canada
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Lim BC, Ki CS, Cho A, Hwang H, Kim KJ, Hwang YS, Kim YE, Yun JY, Jeon BS, Lim YH, Paek SH, Chae JH. Pantothenate kinase-associated neurodegeneration in Korea: recurrent R440P mutation in PANK2 and outcome of deep brain stimulation. Eur J Neurol 2011; 19:556-61. [PMID: 22103354 DOI: 10.1111/j.1468-1331.2011.03589.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of this study was to evaluate the mutation status of PANK2 among Korean patients with pantothenate kinase-associated neurodegeneration (PKAN) and to document the outcome of pallidal deep brain stimulation (DBS). METHODS Direct sequencing and deletion/duplication analysis of PANK2 were conducted in 12 patients (11 unrelated) with PKAN, diagnosed on the basis of extrapyramidal dysfunction and the 'eye-of-the-tiger sign' on brain magnetic resonance imaging (MRI). Pallidal DBS was conducted in four patients, and the outcomes were measured using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). RESULTS A PANK2 mutation was identified in both alleles in all patients. The most prevalent mutation was c.1319G>C (p.R440P) in 8/22 mutated alleles (36%). An intragenic deletion ranging from exons 2 to 4 was found in one allele (1/22, 4.5%) using deletion/duplication analysis. The outcome of pallidal DBS was favorable in two patients with atypical PKAN and moderate severity of dystonia. However, two patients with typical PKAN and relatively severe symptoms showed variable responses. CONCLUSIONS The c.1319G>C (p.R440P) mutation appears to be a founder genotype among Korean patients with PKAN. Furthermore, this study provides additional data for the recent international effort to evaluate the efficacy of pallidal DBS in the treatment of patients with PKAN.
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Affiliation(s)
- B C Lim
- Department of Pediatrics, Seoul National University College of Medicine, Seoul National University Children's Hospital, Seoul, Korea.
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Lim YH, Relus Kek YL, Lim PY, Yap HM, Vivien Goh TL, Ng LC. Environmental surveillance and molecular characterization of Legionella in tropical Singapore. Trop Biomed 2011; 28:149-159. [PMID: 21602781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Legionnaires' disease is often acquired by inhalation of legionellae from a contaminated environmental source. In recent years, Singapore has seen an increase in the use of aerosol-generating fixtures such as mist fans and spa pools. Poorly maintained and designed water fixtures could pose a public health threat to the community. In this study, we provided an update on the prevalence of Legionella in mist fans (N=28), household water heaters with storage tanks (N=19) and instantaneous heaters (N=30); and extended the survey to spa pools (N=29) and aerosol-generating fixtures in nursing homes (N=116). The prevalence of Legionella were 21.1% in water heaters with storage tanks, 24.1% in spa pools, 14.2% in mist fans and 3.3% in instantaneous heaters. Legionella was not detected in nursing homes. A total of 37 isolates were subjected to molecular characterization using Sequence-Based Typing (SBT) protocol from the European Working Group on Legionella Infections (EWGLI). This is the first study on the use of SBT protocol on environmental strains isolated from tropical South East Asia. The Legionella flora was very heterogenous. The overall diversity of the allelic profile was found to be 0.970 (95% CI 0.946 - 0.994). All known STs of our isolates have been associated with clinical cases in EWGLI database. The phylogenetic analysis showed that our novel environmental isolates were clustered with clinical STs that were previously reported in Europe, Japan, United Kingdom and United States etc. (in EWGLI database), suggesting that Legionella found in the environment of Singapore may potentially cause human disease.
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Affiliation(s)
- Y H Lim
- Environmental Health Institute, National Environment Agency, Singapore, 11 Biopolis Way #06-05/08 Helios Block Singapore 138667
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Abstract
Background The small subunit (SSU) processome is a large ribonucleoprotein complex involved in small ribosomal subunit assembly. It consists of the U3 snoRNA and ∼72 proteins. While most of its components have been identified, the protein-protein interactions (PPIs) among them remain largely unknown, and thus the assembly, architecture and function of the SSU processome remains unclear. Methodology We queried PPI databases for SSU processome proteins to quantify the degree to which the three genome-wide high-throughput yeast two-hybrid (HT-Y2H) studies, the genome-wide protein fragment complementation assay (PCA) and the literature-curated (LC) datasets cover the SSU processome interactome. Conclusions We find that coverage of the SSU processome PPI network is remarkably sparse. Two of the three HT-Y2H studies each account for four and six PPIs between only six of the 72 proteins, while the third study accounts for as little as one PPI and two proteins. The PCA dataset has the highest coverage among the genome-wide studies with 27 PPIs between 25 proteins. The LC dataset was the most extensive, accounting for 34 proteins and 38 PPIs, many of which were validated by independent methods, thereby further increasing their reliability. When the collected data were merged, we found that at least 70% of the predicted PPIs have yet to be determined and 26 proteins (36%) have no known partners. Since the SSU processome is conserved in all Eukaryotes, we also queried HT-Y2H datasets from six additional model organisms, but only four orthologues and three previously known interologous interactions were found. This provides a starting point for further work on SSU processome assembly, and spotlights the need for a more complete genome-wide Y2H analysis.
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Affiliation(s)
- Young H. Lim
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - J. Michael Charette
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Susan J. Baserga
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
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Abstract
BACKGROUND Anesthetic titration using spectral entropy monitoring reduces anesthetic requirements and shortens recovery in adult surgical patients. This study was performed to evaluate the effect of entropy monitoring on end-tidal sevoflurane concentration and recovery characteristics in pediatric patients undergoing sevoflurane anesthesia. METHODS Seventy-eight children (aged 3-12 years) scheduled for a tonsillectomy and/or an adenoidectomy were randomly divided into one of two groups: standard practice (Standard) or entropy-guided (Entropy). In the Standard group, sevoflurane was adjusted to maintain the heart rate and systolic blood pressure (BP) within 20% of the baseline values. In the Entropy group, sevoflurane was adjusted to achieve a state entropy of 40-50. We compared the entropy values, end-tidal sevoflurane concentration and recovery times between groups. RESULTS During maintenance of anesthesia, the entropy and BP values were higher in the Entropy group (P<0.05). The end-tidal sevoflurane concentration during maintenance was lower in the Entropy group (2.2 (0.3) vol%) compared with the Standard group (2.6 (0.4) vol%) (P<0.05). Recovery times were faster in the Entropy group (P<0.05). CONCLUSIONS Compared with standard practice, we found that entropy-guided anesthetic administration was associated with a reduced sevoflurane concentration and a slightly faster emergence and recovery in 3-12-year-old children.
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Affiliation(s)
- S R Choi
- Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, South Korea
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Saw JT, Bahari MB, Ang HH, Lim YH. Herbal use amongst multiethnic medical patients in Penang Hospital: pattern and perceptions. Med J Malaysia 2006; 61:422-32. [PMID: 17243519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A cross sectional survey on pattern and perception of herbal use among medical patients in Penang Hospital was conducted. Among 250 patients surveyed, 67.9% were using herbal medicine and conventional medicine concomitantly. A majority of the patients used herbs for health maintenance (51.3%) purpose. More than 90% of herbal users did not disclose herbal use to their physician and "Doctor never asked" was the major reason given (54.2%). The Chinese reported the highest rate of herbal use but was least likely to disclose. These findings are important for health professionals to ensure medication safety and recognise potential drug herb interaction.
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Affiliation(s)
- J T Saw
- School of Pharmacy, University College Sedaya International, No 1, Jalan Menara Goding, UCSI Heights, 56000 Kuala Lumpur, Malaysia
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Abstract
At least 11 HLA-DRB1*12 alleles have been identified to date. We report a new HLA-DRB1*12 allele, DRB1*1210, that was identified in the Korean population. This new allele differs from HLA-DRB1*120101 by a single nucleotide at position 40 (G-->A) in exon 1 that falls within codon--16 (GTT-->ATT). This change results in a single valine to isoleucine amino acid alteration.
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Affiliation(s)
- E Kim
- National Genome Research Institute, National Institute of Health, Eunpyung-gu, Seoul, South Korea
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Abstract
We examined the combined effects of gamma-radiation (24 degrees C) on spores of Clostridium botulinum-type Eklund strain suspended in different gas-saturated Na-phosphate buffer in absence or presence of protectors or sensitizers. Response surface methodology (RSM) was also used to ascertain the effects of radiation on the recovery of spores using a medium containing various levels of NaCl or Na-thioglycollate. The former (< 0.5%) decreased viable spore counts, but the latter (0.15%) did not. Irradiation inactivation of Eklund spores was most effective in air-saturated buffers compared to N2O and N2 gas. The Na2-EDTA (0.01 M) was the most efficient radioprotector of spores due to its reactivity toward hydroxy radicals, followed by t-butanol (0.1 M) in NO2 or N(2)-saturated buffers, respectively. Catalase (10.0 mg ml(-1)) and DL-cysteine (0.1 mM) sensitized the spores during irradiated N2O or N(2)-saturated buffers, and NaCl (0.01 M) only sensitized spores in N2 environment. Spores frozen at -75 degrees C for 30 days and thawed prior to use were more sensitive to radiation damage compared to freshly prepared spores. Glycerol (15%), in Na-phosphate buffer (pH 7.0, 0.06 M), protected Eklund spores and increased the number of spores from 10(6) to 10(11) colony forming unit (CFU) ml(-1), and enhanced their radiosensitivities. Seven strains of C. botulinum type E were screened for plasmids and strain BL764 had two plasmids (15.8 and 46.8 mDa), BL4028 also had two (4.4 and 13.2 mDa), BL4850 contained only one (4.9 mDa), whereas EQA, BL211, Eklund, and Beluga had none. Gamma-Radiation (10 kGy, absorbed dose) cured the 15.8-mDa plasmid in strain BL764, but its absence yielded no changes in toxigenicity.
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Affiliation(s)
- Y H Lim
- Department of Food Science and Technology, University of Georgia, Athens, GA 30602, USA
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Abstract
[reaction: see text] Photocycloaddition of 2-pyridones yields a rigid polycyclic product containing a 1,5-cyclooctadiene. The cis isomer, with the alkenes in close proximity, undergoes a transannular reaction when treated with chlorine to give a polyquinane product. The chlorination reaction involves migration of an amide nitrogen and forms a single isomer, generating eight stereogenic centers in two steps.
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Affiliation(s)
- T A Ader
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400
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Yoon HG, Kim HY, Lim YH, Kim HK, Shin DH, Hong BS, Cho HY. Identification of essential amino acid residues for catalytic activity and thermostability of novel chitosanase by site-directed mutagenesis. Appl Microbiol Biotechnol 2001; 56:173-80. [PMID: 11499927 DOI: 10.1007/s002530000571] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The functional importance of a conserved region in a novel chitosanase from Bacillus sp. CK4 was investigated. Each of the three carboxylic amino acid residues (Glu-50, Glu-62, and Asp-66) was changed to Asp and Gln or Asn and Glu by site-directed mutagenesis, respectively. The Asp-66-->Asn and Asp-66-->Glu mutation remarkably decreased kinetic parameters such as Vmax and kcat to approximately 1/1,000 those of the wild-type enzyme, indicating that the Asp-66 residue was essential for catalysis. The thermostable chitosanase contains three Cys residues at positions 49, 72, and 211. The Cys-49-->Ser/Tyr and Cys-72-->Ser/Tyr mutant enzymes were as stable to thermal inactivation and denaturating agents as the wild-type enzyme. However, the half-life of the Cys-211-->Ser/Tyr mutant enzyme was less than 10 min at 80 degrees C, while that of the wild-type enzyme was about 90 min. Moreover, the residual activity of Cys-211-->Ser/Tyr enzyme was substantially decreased by 8 M urea; and it lost all catalytic activity in 40% ethanol. These results show that the substitution of Cys with any amino acid residues at position 211 seems to affect the conformational stability of the chitosanase.
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Affiliation(s)
- H G Yoon
- Department of Food and Biotechnology, Graduate School of Biotechnology, Korea University, Seoul
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Hoag KA, Clise-Dwyer K, Lim YH, Nashold FE, Gestwicki J, Cancro MP, Hayes CE. A quantitative-trait locus controlling peripheral B-cell deficiency maps to mouse Chromosome 15. Immunogenetics 2000; 51:924-9. [PMID: 11003386 DOI: 10.1007/s002510000223] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [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: 11/27/2022]
Abstract
Peripheral B-lymphocyte homeostasis is determined through incompletely defined positive and negative regulatory processes. The A/WySnJ mouse, but not the related A/J strain, has disturbed homeostasis leading to peripheral B-lymphocyte deficiency. B lymphopoeisis is normal in A/WySnJ mice, but the B cells apoptose rapidly in the periphery. This B cell-intrinsic defect segregated as a single locus, Bcmd, in (A/WySnJxA/J)F2 mice. Here we mapped a quantitative-trait locus (QTL) that contributes to the A/WySnJ B-cell deficiency by examining the F2 progeny of a cross between strains A/WySnJ and CAST/Ei. In this cross, minimally 1.9 QTLs controlling peripheral B lymphocyte deficiency segregated. The (A/WySnJxCAST/Ei)F2 mice were phenotyped for splenic B-cell percentage and the DNA from progeny with extreme phenotypes was used to map the QTL by the simple-sequence length polymorphism method. A genome scan showed linkage between peripheral B-cell deficiency and Chromosome (Chr) 15 markers. When closely spaced Chr 15 markers were analyzed, the 99% confidence interval for the QTL map position extended along the entire chromosome length. The peak lod scores >17 occurred between 30 and 45 cM. We conclude that a significant QTL segregating in (A/WySnJxCAST/Ei)F2 mice resides in this middle region of Chr 15.
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Affiliation(s)
- K A Hoag
- Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison, 53706, USA
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Yoon HG, Kim HY, Lim YH, Kim HK, Shin DH, Hong BS, Cho HY. Thermostable chitosanase from Bacillus sp. Strain CK4: cloning and expression of the gene and characterization of the enzyme. Appl Environ Microbiol 2000; 66:3727-34. [PMID: 10966383 PMCID: PMC92213 DOI: 10.1128/aem.66.9.3727-3734.2000] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A thermostable chitosanase gene from the environmental isolate Bacillus sp. strain CK4, which was identified on the basis of phylogenetic analysis of the 16S rRNA gene sequence and phenotypic analysis, was cloned, and its complete DNA sequence was determined. The thermostable chitosanase gene was composed of an 822-bp open reading frame which encodes a protein of 242 amino acids and a signal peptide corresponding to a 30-kDa enzyme. The deduced amino acid sequence of the chitosanase from Bacillus sp. strain CK4 exhibits 76.6, 15.3, and 14.2% similarities to those from Bacillus subtilis, Bacillus ehemensis, and Bacillus circulans, respectively. C-terminal homology analysis shows that Bacillus sp. strain CK4 belongs to cluster III with B. subtilis. The gene was similar in size to that of the mesophile B. subtilis but showed a higher preference for codons ending in G or C. The enzyme contains 2 additional cysteine residues at positions 49 and 211. The recombinant chitosanase has been purified to homogeneity by using only two steps with column chromatography. The half-life of the enzyme was 90 min at 80 degrees C, which indicates its usefulness for industrial applications. The enzyme had a useful reactivity and a high specific activity for producing functional oligosaccharides as well, with trimers through hexamers as the major products.
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Affiliation(s)
- H G Yoon
- Graduate School of Biotechnology, Korea University, Seoul 136-701, Korea
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