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Yoon DS, Lee KM, Kim SH, Kim SH, Jung Y, Kim SH, Park KH, Choi Y, Ryu HA, Choi WJ, Lee JW. Synergistic Action of IL-8 and Bone Marrow Concentrate on Cartilage Regeneration Through Upregulation of Chondrogenic Transcription Factors. Tissue Eng Part A 2016; 22:363-74. [DOI: 10.1089/ten.tea.2015.0425] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Yoon DS, Choi Y, Jang Y, Lee M, Choi WJ, Kim SH, Lee JW. SIRT1 directly regulates SOX2 to maintain self-renewal and multipotency in bone marrow-derived mesenchymal stem cells. Stem Cells 2015; 32:3219-31. [PMID: 25132403 DOI: 10.1002/stem.1811] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/16/2014] [Indexed: 12/27/2022]
Abstract
SOX2 is crucial for the maintenance of the self-renewal capacity and multipotency of mesenchymal stem cells (MSCs); however, the mechanism by which SOX2 is regulated remains unclear. Here, we report that RNA interference of sirtuin 1 (SIRT1) in human bone marrow (BM)-derived MSCs leads to a decrease of SOX2 protein, resulting in the deterioration of the self-renewal and differentiation capacities of BM-MSCs. Using immunoprecipitation, we demonstrated direct binding between SIRT1 and SOX2 in HeLa cells overexpressing SOX2. We further discovered that the RNA interference of SIRT1 induces the acetylation, nuclear export, and ubiquitination of SOX2, leading to proteasomal degradation in BM-MSCs. SOX2 suppression by trichostatin A (TSA), a known histone deacetylase inhibitor, was reverted by treatment with resveratrol (0.1 and 1 µM), a known activator of SIRT1 in BM-MSCs. Furthermore, 0.1 and 1 µM resveratrol reduced TSA-mediated acetylation and ubiquitination of SOX2 in BM-MSCs. SIRT1 activation by resveratrol enhanced the colony-forming ability and differentiation potential to osteogenic and adipogenic lineages in a dose-dependent manner. However, the enhancement of self-renewal and multipotency by resveratrol was significantly decreased to basal levels by RNA interference of SOX2. These results strongly suggest that the SIRT1-SOX2 axis plays an important role in maintaining the self-renewal capability and multipotency of BM-MSCs. In conclusion, our findings provide evidence for positive SOX2 regulation by post-translational modification in BM-MSCs through the inhibition of nuclear export and subsequent ubiquitination, and demonstrate that SIRT1-mediated deacetylation contributes to maintaining SOX2 protein in the nucleus.
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Lee M, Kwon JW, Choi WJ, Lee JW. Comparison of Outcomes for Osteochondral Lesions of the Talus With and Without Chronic Lateral Ankle Instability. Foot Ankle Int 2015; 36:1050-7. [PMID: 25869235 DOI: 10.1177/1071100715581477] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Previous reports suggest that prolonged instability of the ankle may contribute to development of osteochondral lesions and eventually lead to osteoarthritis. However, no studies have directly compared osteochondral lesions in ankles with chronic lateral ankle instability (CLAI) to those without instability. This study was performed to determine characteristics and resulting clinical outcomes associated with osteochondral lesions of the talus (OLT) in patients with and without instability. METHODS Of 420 patients who underwent primary arthroscopic marrow stimulation for OLT, 74 patients were identified as having concomitant CLAI. After considering age, sex, body mass index, and initial trauma history for the propensity score (1:2 ratio), a total of 148 patients without CLAI were matched from the remainder of the cohort. Demographics and lesion characteristics were compared using preoperative magnetic resonance imaging (MRI) and arthroscopy. Clinical outcomes were compared using a visual analog scale (VAS), the American Orthopaedic Foot & Ankle Society (AOFAS) ankle score, and the Foot and Ankle Outcome Score (FAOS). RESULTS The OLT group with CLAI presented a significantly increased proportion of lateral-side OLT, large OLT (150 mm(2) or larger), and chondral lesions at the tip of the medial malleolus (P = .018, P = .024, and P < .001, respectively). VAS and AOFAS scores were comparable at the last follow-up. However, the OLT with CLAI group also exhibited a significantly increased proportion of failure (AOFAS score less than 80) and inferior outcomes in the FAOS for the sport and recreation subscale (P = .034 and P = .005, respectively). CONCLUSIONS Compared with osteochondral lesions in ankles without CLAI, osteochondral lesions in an unstable ankle had an increased proportion of larger lesions (150 mm(2) or larger) and additional chondral lesions at the tip of the medial malleolus and the tibia plafond. This group also displayed increased clinical failure (AOFAS score less than 80). Inferior performance in sport and recreational activities may be more likely in patients with both OLT and CLAI. LEVEL OF EVIDENCE Level III, retrospective cohort study.
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Konkit M, Choi WJ, Kim W. Alcohol dehydrogenase activity in Lactococcus chungangensis: Application in cream cheese to moderate alcohol uptake. J Dairy Sci 2015; 98:5974-82. [DOI: 10.3168/jds.2015-9697] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 05/25/2015] [Indexed: 02/04/2023]
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Salehiyan R, Song HY, Choi WJ, Hyun K. Characterization of Effects of Silica Nanoparticles on (80/20) PP/PS Blends via Nonlinear Rheological Properties from Fourier Transform Rheology. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00679] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Chan AW, Cordeiro E, Choi WJ, Hamilton TD, Merchant SJ, Angarita FA, Turner BT, Poushay HM, Alabbas HH, Eskicioglu C, Broadhurst D, Mercier P, Schiller D, Eurich DT, Robbins S, Sawyer MB, Gervais MK, Shah P, Hong NL, Wright FC, Cleghorn MC, Jiang H, Jackson TD, Okrainec A, Quereshy FA, Tsang ME, Kim A, Selby D, Wright FC, Ituarte PH, Choi A, Sun V, Chao J, Kim J, Hassan S, Cannell AJ, Dickson BC, Gladdy RA, Swallow CJ, Hogg D, Gupta A, Blackstein ME, McCart JA, Bowes J, Fasola C, Ball C, Dixon E, Sutherland FR, Bathe OF, Hallet J, Look-Hong N, Wright FC, Rodriguez-Rivera AM, Krotneva S, Chang SL, Patakfalvi L, Landry T, Meguerditchian A, Amin N, Cadeddu M, Forbes S, Kelly S, Yang I, Tsai S, Francescutti V, Coates A, Grubac V, Sonnandara R, Simunovic M. Canadian Society of Surgical Oncology Annual General MeetingUrinary metabolomics of gastric cancerSentinel lymph node biopsy in thin melanoma: a systematic review and meta-analysisPreoperative neutrophil:lymphocyte ratio is a better prognostic serum biomarker than platelet:lymphocyte ratio in patients undergoing resection for nonmetastatic colorectal cancerPatient decision-making in palliative surgeryHospital readmission after surgery for gastric cancer: frequency, timing, etiologies and survivalClinical features and outcomes of 20 patients with desmoplastic small round cell tumourBiliary drainage procedures for palliation of extrahepatic cholangiocarcinomaLong-term outcomes following level-3 axillary lymph node dissection for breast cancerAdverse events related to lymph node dissection for cutaneous melanoma: a systematic review and meta-analysisCollaborative case conferences in rectal cancer: case series in a tertiary care centre. Can J Surg 2015; 58:S71-7. [DOI: 10.1503/cjs.005615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Han SH, Park EH, Jo J, Koh YG, Lee JW, Choi WJ, Kim YS. First metatarsal proximal opening wedge osteotomy for correction of hallux valgus deformity: comparison of straight versus oblique osteotomy. Yonsei Med J 2015; 56:744-52. [PMID: 25837181 PMCID: PMC4397445 DOI: 10.3349/ymj.2015.56.3.744] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE The aim of this study was to compare clinical and radiographic outcomes of proximal opening wedge osteotomy using a straight versus oblique osteotomy. MATERIALS AND METHODS We retrospectively reviewed 104 consecutive first metatarsal proximal opening wedge osteotomies performed in 95 patients with hallux valgus deformity. Twenty-six feet were treated using straight metatarsal osteotomy (group A), whereas 78 feet were treated using oblique metatarsal osteotomy (group B). The hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle, and distance from the first to the second metatarsal (distance) were measured for radiographic evaluation, whereas the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score was used for clinical evaluation. RESULTS Significant corrections in the HVA, IMA, and distance from the first to the second metatarsal were obtained in both groups at the last follow-up (p<0.001). There was no difference in the mean IMA correction between the 2 groups (6.1±2.7° in group A and 6.0±2.1° in group B). However, a greater correction in the HVA and distance from the first to the second metatarsal were found in group B (HVA, 13.2±8.2°; distance, 25.1±0.2 mm) compared to group A (HVA, 20.9±7.7°; distance, 28.1±0.3 mm; p<0.001). AOFAS scores were improved in both groups. However, group B demonstrated a greater improvement relative to group A (p=0.005). CONCLUSION Compared with a straight first metatarsal osteotomy, an oblique first metatarsal osteotomy yielded better clinical and radiological outcomes.
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Choi WJ, Cleghorn MC, Jiang H, Jackson TD, Okrainec A, Quereshy FA. Preoperative Neutrophil-to-Lymphocyte Ratio is a Better Prognostic Serum Biomarker than Platelet-to-Lymphocyte Ratio in Patients Undergoing Resection for Nonmetastatic Colorectal Cancer. Ann Surg Oncol 2015; 22 Suppl 3:S603-13. [PMID: 25900206 DOI: 10.1245/s10434-015-4571-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Current risk stratification tools for patients with colorectal cancer (CRC) rely on final surgical pathology but may be improved with the addition of novel serum biomarkers. The objective of this study was to evaluate the utility of preoperative NLR and PLR in predicting long-term oncologic outcomes in patients with operable CRC. METHODS All patients who underwent curative resection for adenocarcinoma at a large tertiary academic hospital were identified. High NLR/PLR was evaluated preoperatively and defined by maximizing log-rank statistics. Recurrence-free survival (RFS) and overall survival (OS) were calculated using the Kaplan-Meier method and compared by the log-rank test. Univariate and multivariable Cox proportional hazard regression was used to identify associations with outcome measures. RESULTS A total of 549 patients were included in the study. High NLR (≥2.6) was associated with worse RFS (hazard ratio [HR] 2.03, 95 % confidence interval [CI] 1.48-2.79, p < 0.001) and OS (HR 2.25, 95 % CI 1.54-3.29, p < 0.001). High PLR (≥295) also was associated with worse RFS (HR 1.68, 95 % CI 1.06-2.65, p = 0.028) and OS (HR 1.81, 95 % CI 1.06-3.06, p = 0.028). In the multivariable model, high NLR retained significance for reduced RFS (HR 1.59, 95 % CI 1.1-2.28, p = 0.013) and OS (HR 1.91, 95 % CI 1.26-2.9, p = 0.002). Significantly more patients in the high NLR group were older at diagnosis, had mucinous adenocarcinoma, higher T stage, and advanced cancer stage. CONCLUSIONS High preoperative NLR in this series was shown to be a negative independent prognostic factor in patients undergoing surgical resection for nonmetastatic CRC. The prognostic utility of this serum biomarker may help to guide use of adjuvant therapies and patient counselling.
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Jeong S, Lee S, Choi WJ, Sohn UD, Kim W. The Effect of Polyphenols Isolated from Cynanchi wilfordii Radix with Anti-inflammatory, Antioxidant, and Anti-bacterial Activity. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 19:151-8. [PMID: 25729277 PMCID: PMC4342735 DOI: 10.4196/kjpp.2015.19.2.151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 12/17/2014] [Accepted: 01/05/2015] [Indexed: 12/21/2022]
Abstract
Recently, Cynanchi wilfordii Radix has gained wide use in Asian countries as a functional food effective for relieving fatigue, osteoporosis, and constipation, particularly in menopausal disorders. However, its anti-inflammatory and anti-microbial activities have not been explored in detail to date. The anti-inflammatory, antioxidant, and anti-bacterial properties of the Cynanchi wilfordii Radix extracts obtained with water, methanol, ethanol, and acetone were compared. All 4 polyphenol-containing extracts exhibited anti-inflammatory and antioxidant effects. The ethanol extract was found to elicit the most potent reduction of nitric oxide (NO), prostaglandin E2 (PGE2), and cytokine (IL-1β, IL-6, IL-10, and TNF-α) levels, as well as inhibit the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a concentration-dependent manner. The evaluation of antioxidant activity also revealed the ethanol extract to have the highest free radical scavenging activity, measured as 85.3±0.4%, which is equivalent to 99.9% of the activity of α -tocopherol. In the assessment of anti-bacterial activity, only ethanol extract was found to inhibit the growth of the Bacillus species Bacillus cereus and Bacillus anthracis. These results show that polyphenols of Cynanchi wilfordii Radix have anti-inflammatory, antioxidant, and anti-bacterial properties that can be exploited and further improved for use as a supplementary functional food, in cosmetics, and for pharmaceutical purposes.
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Choi WJ, Cripton PA, Robinovitch SN. Effects of hip abductor muscle forces and knee boundary conditions on femoral neck stresses during simulated falls. Osteoporos Int 2015; 26:291-301. [PMID: 25027112 DOI: 10.1007/s00198-014-2812-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED Through experiments that simulated sideways falls with a mechanical hip impact simulator, we demonstrated the protective effect of hip abductor muscle forces in reducing peak stresses at the femoral neck and the corresponding risk for hip fracture. INTRODUCTION Over 90% of hip fractures are due to falls, and an improved understanding the factors that separate injurious and non-injurious falls (via their influence on the peak stress generated at the femoral neck) may lead to improved risk assessment and prevention strategies. The purpose of this study was to measure the effect of muscle forces spanning the hip, and knee boundary conditions, on peak forces and estimated stresses at the femoral neck during simulated falls with a mechanical system. METHODS We simulated hip abductor muscle forces and knee boundary conditions with a mechanical hip impact simulator and measured forces and stresses at the femoral neck during sideways falls. RESULTS Peak compressive and tensile stresses, shear force, bending moment, and axial force are each associated with hip abductor muscle forces and knee boundary conditions (p < 0.0005). When muscle force increased from 400 to 1,200 N, peak compressive and tensile stresses decreased 24 and 56%, respectively. These effects were similar to the magnitude of decline in fracture strength associated with osteoporosis and arose from the tension-band effect of the muscle in reducing the bending moment by 37%. Furthermore, peak compressive and tensile stresses averaged 40 and 51% lower, respectively, in the free knee than fixed knee condition. CONCLUSIONS Contraction of the hip abductor muscles at the moment of impact during a fall, and landing with the knee free of constraints, substantially reduced peak compressive and tensile stresses at the femoral neck and risk for femoral fracture in a sideways fall.
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Kim WS, Choi WJ, Lee S, Kim WJ, Lee DC, Sohn UD, Shin HS, Kim W. Anti-inflammatory, Antioxidant and Antimicrobial Effects of Artemisinin Extracts from Artemisia annua L. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 19:21-7. [PMID: 25605993 PMCID: PMC4297758 DOI: 10.4196/kjpp.2015.19.1.21] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/05/2014] [Accepted: 10/15/2014] [Indexed: 12/12/2022]
Abstract
The anti-inflammatory, antioxidant, and antimicrobial properties of artemisinin derived from water, methanol, ethanol, or acetone extracts of Artemisia annua L. were evaluated. All 4 artemisinin-containing extracts had anti-inflammatory effects. Of these, the acetone extract had the greatest inhibitory effect on lipopolysaccharide-induced nitric oxide (NO), prostaglandin E2 (PGE2), and proinflammatory cytokine (IL-1β , IL-6, and IL-10) production. Antioxidant activity evaluations revealed that the ethanol extract had the highest free radical scavenging activity, (91.0±3.2%), similar to α-tocopherol (99.9%). The extracts had antimicrobial activity against the periodontopathic microorganisms Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum subsp. animalis, Fusobacterium nucleatum subsp. polymorphum, and Prevotella intermedia. This study shows that Artemisia annua L. extracts contain anti-inflammatory, antioxidant, and antimicrobial substances and should be considered for use in pharmaceutical products for the treatment of dental diseases.
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Choi WJ, Russell CM, Tsai CM, Arzanpour S, Robinovitch SN. Age-related changes in dynamic compressive properties of trochanteric soft tissues over the hip. J Biomech 2014; 48:695-700. [PMID: 25596629 DOI: 10.1016/j.jbiomech.2014.12.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 10/02/2014] [Accepted: 12/05/2014] [Indexed: 10/24/2022]
Abstract
Hip fracture risk increases dramatically with age, and 90% of fractures are due to falls. During a fall on the hip, the soft tissues overlying the hip region (skin, fat, and muscle) act as shock absorbers to absorb energy and reduce the peak force applied to the underlying bone. We conducted dynamic indentation experiments with young women (aged 19-30; n=17) and older women (aged 65-81; n=17) to test the hypothesis that changes occur with age in the stiffness and damping properties of these tissues. Tissue stiffness and damping were derived from experiments where subjects lay sideways on a bed with the greater trochanter contacting a 3.8cm diameter indenter, which applied sinusoidal compression between 5 to 30Hz with a peak-to-peak amplitude of 1mm. Soft tissue thickness was measured using ultrasound. On average, stiffness was 2.9-fold smaller in older than young women (5.7 versus 16.8kN/m, p=0.0005) and damping was 3.5-fold smaller in older than young women (81 versus 282Ns/m, p=0.001). Neither parameter associated with soft tissue thickness. Our results indicate substantial age-related reductions in the stiffness and damping of soft tissues over the hip region, which likely reduce their capacity to absorb and dissipate energy (before "bottoming out") during a fall. Strategies such as wearable hip protectors or compliant flooringmay compensate for age-related reductions in the shock-absorbing properties of soft tissues and decrease the injury potential of falls.
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Yang J, Lee S, Choi WJ, Seo H, Kim P, Kim GJ, Kim YW, Shin J. Thermoset Elastomers Derived from Carvomenthide. Biomacromolecules 2014; 16:246-56. [DOI: 10.1021/bm501450c] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Choi WJ, Park MS, Park KH, Courneya JP, Cho JS, Schon LC, Lee JW. Comparative analysis of gene expression in normal and degenerative human tendon cells: effects of cyclic strain. Foot Ankle Int 2014; 35:1045-56. [PMID: 24958764 DOI: 10.1177/1071100714540885] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Tendinopathy is a clinical problem for which treatment shows mixed results and treatment options are limited. Gene expression signatures early in the mechanotransduction pathway can accurately predict risk and correlate with different clinical outcomes. Studies aimed at elucidating the molecular mechanisms of tendinopathy have focused on small cohorts of genes that show an incomplete picture of the degeneration process. This study compared the effect of cyclic strain on gene expression in tendon cells from normal tendon and chronically painful areas of tendinopathy in 3 patients. METHODS We measured a panel of mechanotransduction genes and cytoskeletal tensional balance with and without cyclic strain, which disrupts connective tissue synthetic-degradative equilibrium. Normal and degenerative tendons were obtained from patients undergoing surgery to treat chronic painful tendinopathy. A cyclic strain model was established to measure cytoskeletal tensional homeostasis. RESULTS Prior to cyclic strain, the normal tendon cells exhibited varying patterns of elevated expression of 7 genes compared with degenerative tendon cells. In response to cyclic strain, gene expression of COL1A1, ITGA6, CTNNA1, and CLEC3B was up-regulated in normal tendon cells. Cyclic strain had no effect on degenerative tendon cells. Cyclic strain exacerbated the inhibition of protein synthesis in both cell types, especially in the degenerative tendon cells. CONCLUSION Alterations in the pattern of gene expression are suggestive of a dynamic equilibrium between synthesis and degradation, whereby cell adhesion molecules are predominantly up-regulated to facilitate cellular reorientation in response to their altered functional environment. CLINICAL RELEVANCE These data might have future applications, including the identification of markers for early diagnosis, targets for drug design, and indicators for treatment responsiveness and prognosis.
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Kim H, Kim HH, Park JS, Shin HJ, Cha JH, Chae EY, Choi WJ. Prediction of pathological complete response of breast cancer patients undergoing neoadjuvant chemotherapy: usefulness of breast MRI computer-aided detection. Br J Radiol 2014; 87:20140142. [PMID: 25162970 DOI: 10.1259/bjr.20140142] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the usefulness of MR computer-aided detection (CAD) in patients undergoing neoadjuvant chemotherapy for prediction of the pathological complete response of tumours. METHODS 148 patients with breast cancer (mean age, 47.3 years; range, 29-72 years) who underwent neoadjuvant chemotherapy were included in our study. They underwent MRI before and after neoadjuvant chemotherapy, and we reviewed the pathological result as the gold standard. The computer-generated kinetic features for each lesion were recorded, and the features analysed included "threshold enhancement" at 50% and 100% minimum thresholds; degree of initial peak enhancement; and enhancement profiles comprising lesion percentages of washout, plateau and persistent enhancement. The final pathological size and character of tumours were correlated with post-chemotherapy mammography, ultrasonography and MR CAD findings. Kruskal-Wallis test and intraclass correlation coefficient were used to analyse the findings. RESULTS We divided the 148 patients into complete pathological response and non-complete pathological response groups. A complete pathological response was defined as no histopathological evidence of any residual invasive cancer cells in the breast or axillary lymph nodes. 39 patients showed complete pathological response, and 109 patients showed non-complete pathological response. Between enhancement profiles of MR CAD, plateau proportion of tumours was significantly correlated with the pathological response of tumours (mean proportion of plateau on complete pathological response group was 27%, p = 0.007). CONCLUSION When plateau proportion of tumours is high, we can predict non-complete pathological response of neoadjuvant chemotherapy. ADVANCES IN KNOWLEDGE MR CAD can be a useful tool for the assessment of response to neoadjuvant chemotherapy and prediction of pathological results.
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Yoon HS, Park YJ, Lee M, Choi WJ, Lee JW. Osteochondral Autologous Transplantation Is Superior to Repeat Arthroscopy for the Treatment of Osteochondral Lesions of the Talus After Failed Primary Arthroscopic Treatment. Am J Sports Med 2014; 42:1896-903. [PMID: 24907287 DOI: 10.1177/0363546514535186] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Several studies have reported on the outcome of arthroscopic treatment or osteochondral autologous transplantation (OAT) for osteochondral lesions of the talus (OLT), with mixed results. None of these studies has compared the results of repeat arthroscopy and OAT after failed primary arthroscopic treatment. PURPOSE To compare the outcomes of OAT and repeat arthroscopy for the treatment of OLT after primary arthroscopy STUDY DESIGN Cohort study; Level of evidence, 3. METHODS This study included 22 patients who underwent OAT (group A) and 22 patients who underwent repeat arthroscopy (group B) after failed treatment of OLT among 399 patients who received primary arthroscopic marrow stimulation at single institution between 2001 and 2009. All patients were evaluated clinically using the visual analog scale (VAS) for pain and American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scale. The cumulative success rates were compared by use of Kaplan-Meier life table analysis. RESULTS The patients' demographic and clinical characteristics and indications for surgery were comparable between the groups. Both groups showed significantly improved (P < .001) VAS and AOFAS scores 6 months after surgery. However, group B showed significant deterioration over a mean follow-up period of 50 months. Overall, 18 of 22 (81.8%) patients in group A and 7 of 22 (31.8%) patients in group B achieved an excellent or good (≥80) AOFAS score (P < .001). No patient in group A and 14 of 22 (63.6%) in group B required further revisions. CONCLUSION Osteochondral autologous transplantation was significantly superior to repeat arthroscopic treatment of OLT after a mean follow-up period of 48 months. Therefore, repeat arthroscopy should be used judiciously for the treatment of OLT after failed arthroscopic treatment.
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Salehiyan R, Yoo Y, Choi WJ, Hyun K. Characterization of Morphologies of Compatibilized Polypropylene/Polystyrene Blends with Nanoparticles via Nonlinear Rheological Properties from FT-Rheology. Macromolecules 2014. [DOI: 10.1021/ma500700e] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ahmad D, Min BH, Ko MJ, Seo YL, Choi WJ, Lee JH, Kim GC, Kim YC, Kwon YS. Superconducting properties of hole doped Ba(0.6)Li(0.4)Fe2As2 single crystal. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:175701. [PMID: 24721709 DOI: 10.1088/0953-8984/26/17/175701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report the emergence of superconductivity in Li doped Ba-122 single crystals grown by the Bridgman method. The superconducting transition temperature Tc,onset is around 19 K. The specific heat capacity C/T shows a weak anomaly near Tc. The value of ΔC/γnTc is smaller than the value predicted in BCS theory indicating a multigap nature of the sample. The magnetic measurements show that the lower critical field Hc1(T) exhibits a linear temperature dependence, with a pronounced change of the Hc1(T) curvature around 0.4Tc and Hc1(0) ≈ 430 Oe in the Ba0.6Li0.4Fe2As2 single crystal. Furthermore, temperature dependence of the penetration depth λ(T) follows a power law (~T(n)) below 0.4Tc which predicts possible S±-wave pairing in a Ba0.6Li0.4Fe2As2 superconductor. Over a wide range of temperatures, the Jc(H) exhibits a relation J(c)[proportionality] H(-α) with α = 0.5 ~ 0.6 for H || c and H || ab which indicates random defects in the sample. We found that the temperature dependence of the critical current density Jc(T) can be fitted well with the δl-type pinning model, whose origin is attributed to spatial variations of charge carrier mean free path l. We suggest that the large mismatch in the ionic radius of Ba and Li can affect the irreversible magnetic properties of the Ba0.6Li0.4Fe2As2 single crystal without any structural transition.
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Oh HJ, Park SJ, Lim JY, Cho NK, Song JD, Lee W, Lee YJ, Myoung JM, Choi WJ. Fabrication of GaAs/Al0.3Ga0.7As multiple quantum well nanostructures on (100) si substrate using a 1-nm InAs relief layer. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2014; 14:2984-2989. [PMID: 24734721 DOI: 10.1166/jnn.2014.8593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanometer scale thin InAs layer has been incorporated between Si (100) substrate and GaAs/Al0.3Ga0.7As multiple quantum well (MQW) nanostructure in order to reduce the defects generation during the growth of GaAs buffer layer on Si substrate. Observations based on atomic force microscopy (AFM) and transmission electron microscopy (TEM) suggest that initiation and propagation of defect at the Si/GaAs interface could be suppressed by incorporating thin (1 nm in thickness) InAs layer. Consequently, the microstructure and resulting optical properties improved as compared to the MQW structure formed directly on Si substrate without the InAs layer. It was also observed that there exists some limit to the desirable thickness of the InAs layer since the MQW structure having thicker InAs layer (4 nm-thick) showed deteriorated properties.
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95
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Park MH, Kim HS, Park SJ, Song JD, Kim SH, Lee YJ, Choi WJ, Park JH. Effect of growth temperature and quantum structure on InAs/GaAs quantum dot solar cell. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2014; 14:2955-2959. [PMID: 24734716 DOI: 10.1166/jnn.2014.8639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
InGaAs-capped InAs quantum dots (QDs) and InAs QDs were adopted for the study of the effects through growth temperature and the band structure of InAs QDs on the performance of GaAs-based QD solar cell. It has been shown that the defects due to low temperature growth resulted in the decrease of Voc, Jsc and external quantum efficiency for GaAs bulk solar cell and QD embedded solar cells. It has been also found that InAs QDs act as defects by trapping photo-generated carries which affect the carrier transport in QD solar cell. The QD solar cell with InGaAs-capped InAs QDs showed higher performance than the QD solar cell with only InAs QDs. Such result has been explained by photo-generated carrier trapping and tunneling through InGaAs QW state in InGaAs-capped InAs QDs.
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96
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Kim DY, Bae MH, Shin JC, Kim YJ, Lee YJ, Choi KJ, Seong TY, Choi WJ. Vertical growth of core-shell III-V nanowires for solar cells application. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2014; 14:2913-2918. [PMID: 24734710 DOI: 10.1166/jnn.2014.8606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
High density (In)GaAs/GaAs/AIGaAs nanowires (NWs) consisting of n-type core and p-type shell have been vertically grown on (111) GaAs substrate using metal organic chemical vapor deposition (MOCVD) and fabricated into solar cells. Au colloidal nanoparticles (NPs) are employed as a catalyst. High density nanowires were obtained by uniform distribution of Au NPs. Fe-SEM, TEM and HRTEM images show that the morphology of shell is sensitive to p-doping concentration. Increase in the density of p-doping precursor results in "kinking" of NPs and rough shell surface. The origin of kinking has been explained by the GaAs twin phases due to Zn segregation on the surface of shell. It has been observed that the morphology of NPs can be controlled through optimizing various source purge technique of DEZn and deposition temperature. Electrical properties of core-shell doped NWs are carried out using I-V characterization. The core-shell NWs show characteristics of p-n junction as revealed by I-V studies.
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97
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Annaluru N, Muller H, Mitchell LA, Ramalingam S, Stracquadanio G, Richardson SM, Dymond JS, Kuang Z, Scheifele LZ, Cooper EM, Cai Y, Zeller K, Agmon N, Han JS, Hadjithomas M, Tullman J, Caravelli K, Cirelli K, Guo Z, London V, Yeluru A, Murugan S, Kandavelou K, Agier N, Fischer G, Yang K, Martin JA, Bilgel M, Bohutski P, Boulier KM, Capaldo BJ, Chang J, Charoen K, Choi WJ, Deng P, DiCarlo JE, Doong J, Dunn J, Feinberg JI, Fernandez C, Floria CE, Gladowski D, Hadidi P, Ishizuka I, Jabbari J, Lau CYL, Lee PA, Li S, Lin D, Linder ME, Ling J, Liu J, Liu J, London M, Ma H, Mao J, McDade JE, McMillan A, Moore AM, Oh WC, Ouyang Y, Patel R, Paul M, Paulsen LC, Qiu J, Rhee A, Rubashkin MG, Soh IY, Sotuyo NE, Srinivas V, Suarez A, Wong A, Wong R, Xie WR, Xu Y, Yu AT, Koszul R, Bader JS, Boeke JD, Chandrasegaran S. Total synthesis of a functional designer eukaryotic chromosome. Science 2014; 344:55-8. [PMID: 24674868 DOI: 10.1126/science.1249252] [Citation(s) in RCA: 371] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Rapid advances in DNA synthesis techniques have made it possible to engineer viruses, biochemical pathways and assemble bacterial genomes. Here, we report the synthesis of a functional 272,871-base pair designer eukaryotic chromosome, synIII, which is based on the 316,617-base pair native Saccharomyces cerevisiae chromosome III. Changes to synIII include TAG/TAA stop-codon replacements, deletion of subtelomeric regions, introns, transfer RNAs, transposons, and silent mating loci as well as insertion of loxPsym sites to enable genome scrambling. SynIII is functional in S. cerevisiae. Scrambling of the chromosome in a heterozygous diploid reveals a large increase in a-mater derivatives resulting from loss of the MATα allele on synIII. The complete design and synthesis of synIII establishes S. cerevisiae as the basis for designer eukaryotic genome biology.
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Choi WJ, Kim SK, Park HK, Sohn UD, Kim W. Anti-Inflammatory and Anti-Superbacterial Properties of Sulforaphane from Shepherd's Purse. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:33-9. [PMID: 24634594 PMCID: PMC3951821 DOI: 10.4196/kjpp.2014.18.1.33] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/09/2013] [Accepted: 12/31/2013] [Indexed: 01/08/2023]
Abstract
Shepherd's purse, Capsella bursa-pastoris (L.) Medik., has been considered a health food for centuries in Asia and is known to contain the isothiocyanate compound sulforaphane. In this study, we evaluated the anti-inflammatory and antibacterial properties of a sulforaphane-containing solution (SCS) isolated from shepherd's purse. SCS had significant anti-inflammatory activity indicated by the decreased levels of nitric oxide (NO), cytokines (interleukin 1β [IL-1β], IL-6, and IL-10), and prostaglandin E2 (PGE2) in lipopolysaccharide-stimulated RAW 264.7 murine macrophages. In addition, SCS decreased the inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2) levels, which confirmed the anti-inflammatory activity of SCS. Further, SCS inhibited vancomycin-resistant enterococci (VRE) and Bacillus anthracis. The minimal inhibitory concentration was 250 µg/ml for VRE and 1,000 µg/ml for B. anthracis. Taken together, these data indicate that SCS has potential anti-inflammatory and anti-superbacterial properties, and thus it can be used as a functional food or pharmaceutical.
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Abstract
BACKGROUND Periprosthetic osteolysis in total ankle arthroplasty (TAA) is a substantial problem. We report the incidence and characteristics of periprosthetic osteolysis and its association with clinical outcomes after TAA using the HINTEGRA ankle system. METHODS Between May 2004 and April 2010, 126 primary TAA were performed on 115 patients. We excluded 27 ankles with a follow-up of less than 24 months; thus, 99 ankles in 90 patients with a mean follow-up of 40.8 (range, 24-89) months were included in the study. Pain and clinical outcomes were assessed using the visual analog scale and the American Orthopaedic Foot and Ankle Society score. Fluoroscopy was used for optimum visualization of the bone-implant interfaces on radiographs. Computed tomography (CT) was conducted on 25 ankles that exhibited progression of osteolysis. RESULTS Radiographs revealed that 37 of the 99 ankles showed radiologic evidence of osteolysis; of these, 10 demonstrated continuous progression over the study period. Helical CT scans were more accurate than radiographs for identifying and measuring periprosthetic osteolysis in TAA. None of the demographic parameters were substantially different between the 2 groups of subjects (with or without osteolysis). No major association was found between the presence of osteolysis and clinical and radiologic outcomes. CONCLUSION Osteolysis associated with TAA may indeed be common in the postoperative period. Although most of the osteolytic lesions observed here were relatively quiescent, these lesions raise concerns in contemporary TAA because of their incidence rate and the potential for later mechanical failure as compared to arthrodesis. Early diagnosis and careful evaluation of osteolysis may provide a clinical opportunity for limited revision surgery in ankles of impending prosthesis failure. LEVEL OF EVIDENCE Level IV, case series.
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100
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Park JK, Kang TG, Kang MY, Park JE, Cho IA, Shin JK, Choi WJ, Lee SA, Choi WS, Kwon HM, Lee JH, Paik WY. Increased NFAT5 expression stimulates transcription of Hsp70 in preeclamptic placentas. Placenta 2013; 35:109-16. [PMID: 24398013 DOI: 10.1016/j.placenta.2013.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 12/10/2013] [Accepted: 12/13/2013] [Indexed: 01/25/2023]
Abstract
OBJECTIVE We investigated the expression of heat shock protein 70 (Hsp70), nuclear factor of activated T cells 5 (NFAT5), and hypoxia-induced factor-1α (HIF-1α) in the placentas of normal and preeclamptic pregnancies and in human placental hypoxia models in vitro to examine the regulatory mechanisms of placental Hsp70 expression. METHODS The expression levels of HIF-1α, NFAT5, and Hsp70 were examined in placental samples from 10 females with preeclampsia and 10 normotensive control patients and in human choriocarcinoma trophoblast cells treated with 1 mM CoCl2 by western blotting. Using models of placental hypoxia, pharmacological inhibition of HIF-1α with chetomin and shRNA knockdown and overexpression of NFAT5 were performed to investigate the roles of HIF-1α and NFAT5 in induction of Hsp70 by placental hypoxia. RESULTS The levels of HIF-1α, NFAT5, and Hsp70 expression were significantly higher in the preeclamptic compared to normal placentas. In the placental hypoxia models, the expression of HIF-1α, NFAT5, and Hsp70 were significantly higher after 3, 6, and 12 h of 1 mM CoCl2 treatment, respectively. Pharmacological inhibition of HIF-1α suppressed the induction of NFAT5 and Hsp70 at the protein level. shRNA knockdown of NFAT5 suppressed the induction of Hsp70 protein and overexpression of NFAT5 stimulated the induction of Hsp70 mRNA and protein in models of human placental hypoxia in vitro. CONCLUSION HIF-1α positively regulates the induction of NFAT5 and Hsp70 by placental hypoxia and NFAT5 stimulates transcription of Hsp70 in response to placental hypoxia in models of human placental hypoxia in vitro.
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