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Cheng Y, Ren X, Gowda ASP, Shan Y, Zhang L, Yuan YS, Patel R, Wu H, Huber-Keener K, Yang JW, Liu D, Spratt TE, Yang JM. Interaction of Sirt3 with OGG1 contributes to repair of mitochondrial DNA and protects from apoptotic cell death under oxidative stress. Cell Death Dis 2013; 4:e731. [PMID: 23868064 PMCID: PMC3730425 DOI: 10.1038/cddis.2013.254] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 05/20/2013] [Accepted: 06/04/2013] [Indexed: 12/16/2022]
Abstract
Sirtuin 3 (Sirt3), a major mitochondrial NAD(+)-dependent deacetylase, targets various mitochondrial proteins for lysine deacetylation and regulates important cellular functions such as energy metabolism, aging, and stress response. In this study, we identified the human 8-oxoguanine-DNA glycosylase 1 (OGG1), a DNA repair enzyme that excises 7,8-dihydro-8-oxoguanine (8-oxoG) from damaged genome, as a new target protein for Sirt3. We found that Sirt3 physically associated with OGG1 and deacetylated this DNA glycosylase and that deacetylation by Sirt3 prevented the degradation of the OGG1 protein and controlled its incision activity. We further showed that regulation of the acetylation and turnover of OGG1 by Sirt3 played a critical role in repairing mitochondrial DNA (mtDNA) damage, protecting mitochondrial integrity, and preventing apoptotic cell death under oxidative stress. We observed that following ionizing radiation, human tumor cells with silencing of Sirt3 expression exhibited deteriorated oxidative damage of mtDNA, as measured by the accumulation of 8-oxoG and 4977 common deletion, and showed more severe mitochondrial dysfunction and underwent greater apoptosis in comparison with the cells without silencing of Sirt3 expression. The results reported here not only reveal a new function and mechanism for Sirt3 in defending the mitochondrial genome against oxidative damage and protecting from the genotoxic stress-induced apoptotic cell death but also provide evidence supporting a new mtDNA repair pathway.
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Harrold L, Cifaldi M, Saunders K, Reed G, Ganguli A, Shan Y, Greenberg J. SAT0469 Factors associated with work status and missed work days in rheumatoid arthritis. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.3415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Pappas D, Hooper M, Reed G, Shan Y, Wenkert D, Zhang J, Greenberg J, Curtis J. FRI0108 Risk for herpes zoster after treatment with biologic and synthetic disease modifying agents for rheumatoid arthritis. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.2565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Harrold L, Reed G, Saunders K, Shan Y, Spruill T, Greenberg J. FRI0434 Patient and provider factors associated with compliance with rheumatoid arthritis treatment recommendations. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.2891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Shan Y, Tang J, Lai H, Tan H, Liu X, Yang F, Fang Q. Ethoxy‐substituted Oligo‐phenylenevinylene‐Bridged Organic Dyes for Efficient Dye‐Sensitized Solar Cells. CHINESE J CHEM 2012. [DOI: 10.1002/cjoc.201200091] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Song C, Zhang Q, Liu X, Shan Y. IL-12 and IL-10 production are differentially regulated by phosphatidylinositol 3-kinase in mast cells. Scand J Immunol 2012; 75:266-72. [PMID: 22023709 DOI: 10.1111/j.1365-3083.2011.02660.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cellular mechanisms that directly regulate the production of pro- and anti-inflammatory cytokines after lipopolysaccharide (LPS) stimulation in mast cells are currently unresolved. The aim of this study was to clarify the role of phosphatidylinositol 3-kinase (PI3K) in the production of IL-12 and IL-10 in mouse bone marrow-derived mast cells (BMMCs), stimulated with Escherichia coli-derived LPS. LPS activates the PI3K signalling pathway; analysis of cytokine production following LPS stimulation of BMMCs revealed that inhibition of the PI3K pathway differentially regulated IL-10 and IL-12 syntheses. IL-12 production was enhanced, whereas IL-10 levels were suppressed. Inhibition of LPS-mediated activation of the PI3K pathway resulted in a pronounced reduction of NF-κB activity that was dependent on IκBα phosphorylation. These findings demonstrate a regulatory function for PI3K in modulating IL-10 and IL-12 production in mast cells and provide insight into how engagement of the PI3K pathway affects the induction of key immunoregulatory cytokines that control both qualitative and quantitative aspects of early inflammation.
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Zhang J, Shan Y, Pan X, He L. Recent advances in antiangiogenic agents with VEGFR as target. Mini Rev Med Chem 2012; 11:920-46. [PMID: 21762098 DOI: 10.2174/138955711797068355] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Revised: 03/25/2011] [Accepted: 05/27/2011] [Indexed: 11/22/2022]
Abstract
Angiogenesis is required for invasive tumor growth and metastasis and constitutes an important point in the control of cancer progression. Its inhibition may be a valuable approach to cancer therapy. Antiangiogenic agents are designed to attack the tumor vasculature and cut off the tumor's supply of nutrients. Systemic blockade of angiogenesis has been recently approved for the treatment of several types of human cancers. Antiangiogenic therapy presents various advantages as compared to conventional treatment. Vascular endothelial growth factor (VEGF) is considered to be one of the most important regulators of angiogenesis and a key target in anticancer treatment. VEGF binding to its receptor (VEGFR) leads to cell proliferation and new vascular formation by tyrosine kinase (TK) pathway. VEGF/VEGFR pathway is becoming attractive target for anticancer drug design. It is believed to be important in the control of angiogenesis. Antiangiogenic therapy based on inhibition of VEGFR was reported to be powerful clinical strategies. In this review, the authors describe the existing literature regarding VEGFR inhibitors in the last few years. We attempt to cover all essential publications on the medicinal chemistry in terms of chemical structure, pharmacological profile and structure-activity relationships.
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Shan Y, Lin N, Yang X, Tan J, Zhao R, Dong S, Wang S. Sulphoraphane inhibited the expressions of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 through MyD88-dependent toll-like receptor-4 pathway in cultured endothelial cells. Nutr Metab Cardiovasc Dis 2012; 22:215-222. [PMID: 20880684 DOI: 10.1016/j.numecd.2010.06.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2010] [Revised: 06/17/2010] [Accepted: 06/21/2010] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND AIMS Chronic inflammation plays pivotal roles in both cancer and cardiovascular diseases. A large body of evidence suggests that high intake of cruciferous vegetables is closely related with low risk of these disorders. However, the underlying mechanisms of protection are not fully understood. The aim of this study is to test the protective effects of an isothiocyanate sulphoraphane on inflammatory injury and related regulation pathways in cultured endothelial cells. METHODS AND RESULTS The expressions of adhesion molecules were determined by TaqMan real-time polymerase chain reaction (PCR) and Western blot analysis. Nuclear factor-kappa B (NF-кB) translocation was detected by immunofluorescent hybridisation. Other proteins were measured by Western blot analysis. The results demonstrated that sulphoraphane significantly suppresses the expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 stimulated by lipopolysaccharide (LPS) both at the transcriptional and translational levels. In addition, sulphoraphane inhibited the translocation of NF-кB into the nucleus. Sulphoraphane decreased the phosphorylation of extra-cellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), while further blockade and activation using individually specific agents confirm that p38 MAPK and JNK are mainly involved. Interestingly, sulphoraphane down-regulated Toll-like receptor (TLR)-4, a receptor of LPS located on the membrane. In addition, MyD88, an effector downstream TLR-4 signal pathway was subsequently attenuated. CONCLUSION Taken all together, adhesion molecules are confirmed to be the novel targets of sulphoraphane in preventing inflammatory insult to endothelial cells. Sulphoraphane suppressed TLR-4 followed by MyD88 and downstream factors such as p38 MAPK and JNK, ultimately blocking NF-кB translocation and the subsequent expression of adhesion molecules. These data suggested a novel inflammatory pathway mediated by sulphoraphane.
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Santhiranayagam P, Thirumalai S, Memom F, Shan Y, Lee SJ, Mobed-Miremadi M, Keralapura M. Acoustic interrogation and optical visualization of ultrasound contrast agents within microcapsules. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2012:495-498. [PMID: 23365937 DOI: 10.1109/embc.2012.6345976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The effectiveness of localized drug delivery as a treatment for breast cancer requires sufficiently high therapeutic dose, as well as an ability to image the drug for proper spatial targeting. To balance treatment potential and imaging capabilities, we have begun to design a novel drug reservoir using microcapsules that are large in size (> 30 µm) but functionalized with microbubbles or ultrasound contrast agents (UCAs). We term these carriers as 'Acoustically Sensitive Microcapsules' (ASMs). In previous work, we have demonstrated preparation of ASM carriers and their structural changes under therapeutic ultrasound by imaging static changes. In this paper, we describe a combined optical-acoustic setup coupled with a microfluidic device to trap these carriers for imaging and sonication. Using the setup, continuous wave ultrasound (180 kPa, 2.25 MHz, 3 s) produced an average displacement of 3.5 µm in UCAs near the ASM boundary, and exhibited displacement as high as 90 µm near the center of the microcapsule. Longer exposure time and higher acoustic pressure increased UCA displacement within an ASM. These two parameters can be carefully optimized in the future to cause these UCAs to travel to the membrane boundary to help in the drug elution process.
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Shan Y, Zhang J, Liu Z, Wang M, Dong Y. Developments of combretastatin A-4 derivatives as anticancer agents. Curr Med Chem 2011; 18:523-38. [PMID: 21143124 DOI: 10.2174/092986711794480221] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 12/20/2010] [Indexed: 11/22/2022]
Abstract
Tubulin protein is one of several members of a small family of globular proteins. It offers a potential target for anticancer drug design and development. Combretastatin A-4 (CA-4) is a potent anticancer and antiangiogenesis natural substance isolated from Combretum caffrum. Modifications on the CA-4 structure have led to a great number of novel CA-4 derivatives as potent tubulin inhibitors and high cytotoxic anticancer agents is becoming an interesting field, leading to a breakthrough in the treatment of cancer. In this review, the recent developments of novel CA-4 derivatives via the modifications on the A- and B-ring and the double bond as anticancer agents are discussed.
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Ko AH, Tempero MA, Shan Y, Su W, Lin Y, Dito E, Ong A, Wang Y, Yeh G, Chen L. A multinational phase II study of PEP02 (liposome irinotecan) for patients with gemcitabine-refractory metastatic pancreatic cancer. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.4069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ko AH, Tempero MA, Shan Y, Su W, Lin Y, Dito E, Ong A, Yeh G, Chen L. A multinational phase II study of liposome irinotecan (PEP02) for patients with gemcitabine-refractory metastatic pancreatic cancer. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.4_suppl.237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
237 Background: PEP02 is a novel nanoparticle liposome formulation of irinotecan (CPT-11) that has improved pharmacokinetics and tumor biodistribution of both CPT-11 and its active metabolite-SN38 compared to the free form drug. PEP02 has showed encouraging safety and efficacy in various tumor types, including significant antitumor activity in a human pancreatic cancer L3.6pl orthotopic nude mouse xenograft model. In previous phase I studies, PEP02 either alone or in combination with 5-FU/LV demonstrated prolonged disease control in 5 of 7 (71%) patients (pts) with gemcitabine (GEM)-refractory advanced pancreatic cancer (PC). This phase II study aims to evaluate PEP02 monotherapy as 2nd-line treatment in pts with metastatic, GEM-refractory PC. Methods: Pts were eligible if they had metastatic pancreatic adenocarcinoma, KPS ≥ 70, and progressed following one line of GEM-based therapy. Treatment consisted of PEP02 120 mg/m2 administered as a 90-minute infusion every 3 weeks. A Simon's 2-stage design was used with 16 pts in the first stage and 39 pts in total; primary objective was 3-month survival rate (OS3-month). Results: Between March 2009 and August 2010, 37 pts were enrolled at 3 centers in the U.S. and Taiwan. Characteristics for the first 31 evaluable pts: 13 M/18 F; age 39-82 yrs; 19 Asian/12 Caucasian, KPS 100/90/80/70: 5/14/4/8. Mean number of treatment cycles is 5 (range, 1-22). Disease control rate (minor response + stable disease >2 cycles) is 52%. 8 of 24 pts (33%) with elevated baseline CA19-9 have had >50% biomarker decline. To date, 23/31 pts (74%) have survived > 3 months, with 4 pts still alive after 1 year. Reasons for study discontinuation: 74% progressive disease, 9% drug-related toxicity, 17% other. Preliminary safety data is available for the first stage. Most common G3/4 adverse events included: fatigue (31%), neutropenia (25%), nausea/vomiting (19%), and diarrhea (13%). Conclusions: This study has already met its primary endpoint (predicted OS3-month >65%). PEP02 appears to have both activity and tolerable side effects for pts with metastatic, GEM-refractory PC, and represents a promising option for this pt population with few standard options. [Table: see text]
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Zhenyan F, Xiang X, Yitong M, Yining Y, Shan Y, Lei W. e0080 The CYP2J2 G50T polymorphism and the risk of coronary artery disease in Han Chinese population. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.208967.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Xue B, Shan Y, Yang D, Cui Y, Gao J, Sun C, Wang W. UP-1.032: Perioperative Management of Patients with Adrenal Tumor Having Undergone Retroperitoneal Laparoscopy: Report of 88 Cases. Urology 2009. [DOI: 10.1016/j.urology.2009.07.479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Zang Y, Shan Y, Xue B, Yang D, Sun C, Gao J. UP-3.082: The Learning Curve of 120-W Photoselective Vaporization of the Prostate for Benign Prostatic Hyperplasia. Urology 2009. [DOI: 10.1016/j.urology.2009.07.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Shan Y, Xue B, Zang Y, Yang D, Sun C. UP-3.078: Greenlight HPS 120-W Laser for Benign Prostatic Hyperplasia (Report of 34 Cases). Urology 2009. [DOI: 10.1016/j.urology.2009.07.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Xue B, Shan Y, Yang D, Cui Y, Gao J, Sun C, Wang W. UP-1.033: Application of Double-Channel Trocar in Retroperitoneal Laparoscopy of the Pelvis and Ureter Diseases. Urology 2009. [DOI: 10.1016/j.urology.2009.07.480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Yang D, Shan Y, Sun C, Tao W, Zhu J, Xue B, Cui Y, Gao J. POD-10.04: Incidence of Urethral Stricture after TVP or PVP for the Treatment of BPH. Urology 2009. [DOI: 10.1016/j.urology.2009.07.1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Moster ML, Roemer RA, Shagass C, Polansky M, Shan Y. Presaccadic spike potential in normal subjects. Neuroophthalmology 2009. [DOI: 10.3109/01658109709014420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ch’ang H, Hwang T, Wang H, Chang M, Tien Y, Chen J, Hsieh R, Lin P, Shan Y, Cheng A, Chen L. A phase II study of gemcitabine-based chemoradiotherapy (CCRT) after triplet induction chemotherapy (ICT) for locally advanced pancreatic cancer (LAPC): A Taiwan Cooperative Oncology Group (TCOG) study. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e15562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e15562 The optimal management of LAPC remains controversial. The efficacy of CCRT is hampered by early systemic dissemination. To treat undetectable metastases and to select patients who are likely to benefit from CCRT, ICT followed by CCRT has recently been extensively evaluated in LAPC. Recently, we showed that triplet chemotherapy consisting of gemcitabine 800 mg/m2 (10 mg/m2/min) followed by oxaliplatin 85 mg/m2 and 48-hour infusion of 5-FU/LV 3,000 and 150 mg/m2 Q 2 weeks, the GOFL regimen, is feasible and active for pts with APC. Chemo-naïve pts with histo- /cytologically proven unresectable LAPC, and bi-dimensionally measurable diseases were eligible. Patients who did not experience disease progression (PD) after 6 cycles of GOFL would had CCRT consisting of weekly gemcitabine 400mg/m2 plus 50.4Gy/28 fractions of radiation 4–6 weeks later. After CCRT, pts were re-evaluated for surgical intervention and those with unresectable disease would continue GOFL until PD, unacceptable toxicity, patient's refusal or death. Among the 50 enrolled pts (24F/26M, median age 58.5 years), 48 had definitively unresectable diseases. After induction GOFL, 16 (32%) pts were off-studied because of PD in 12 (24%) and ICT-related toxicity in 4 (8%, PD/UE group). Among the 34 (68%) with objective response or stable disease after 6 cycles of ICT, 27 (54%) who completed the assigned multimodality treatment are categorized as CCRT group; whiles 7 (14%) who either declined CCRT (in 5) or still on ICT (in 2) are categorized as non-CCRT group. The median PFS and OS for the ITT population were 9.1 and 14.5 months, respectively. The median PFS for PD/UE, non-CCRT and CCRT groups were 2.1, 8.2 and 12.8 months, respectively; whiles the OS were 8.5, 15.0 and 18.3 months, respectively. The most common grade 3–4 toxicities were neutropenia (40%), anemia (14%), infection (16%), nausea (26%), vomiting (20%). Grade 2–3 peripheral neuropathy was observed in 7 of 29 who received post-CCRT GOFL. Conclusion: Three months of triplet ICT followed by gemcitabine-based CCRT is feasible and likely to prolong the survival of selected LAPC pts. Prospective, randomization study is warranted to validate the findings. No significant financial relationships to disclose.
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Fu JH, Xie SR, Kong SJ, Wang Y, Wei W, Shan Y, Luo YM. The Combination of a High-fat Diet and Chronic Stress Aggravates Insulin Resistance in Wistar Male Rats. Exp Clin Endocrinol Diabetes 2009; 117:354-60. [DOI: 10.1055/s-0028-1119406] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Wazir NN, Shan Y, Mukundala VV, Gunalan R. Dislocation after total knee arthroplasty. Singapore Med J 2007; 48:e138-40. [PMID: 17453086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Two cases of dislocation of total knee arthroplasty presented to us within the same week. The first patient is a 71-year-old woman who underwent bilateral primary total knee arthroplasty. The left knee dislocated three weeks after the surgery. Due to failure of conservative measures, she underwent revision total knee arthroplasty. The other patient is a 72-year-old woman presenting ten years after primary total knee arthroplasty, with a traumatic dislocation of the knee joint. She was treated as an outpatient with closed manipulative reduction.
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Jing YJ, Hao YJ, Qu H, Shan Y, Li DS, Du RQ. Studies on the antibacterial activities and mechanisms of chitosan obtained from cuticles of housefly larvae. ACTA BIOLOGICA HUNGARICA 2007; 58:75-86. [PMID: 17385545 DOI: 10.1556/abiol.57.2007.1.7] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chitosan was obtained from cuticles of the housefly (Musca domestica) larvae. Antibacterial activities of different Mw chitosans were examined against six bacteria. Antibacterial mechanisms of chitosan were investigated by measuring permeability of bacterial cell membranes and observing integrity of bacterial cells. Results show that the antibacterial activity of chitosan decreased with increase in Mw. Chitosan showed higher antibacterial activity at low pH. Ca2+ and Mg2+ could markedly reduce the antibacterial activity of chitosan. The minimum inhibitory concentrations of chitosans ranged from 0.03% - 0.25% and varied with the type of bacteria and Mw of chitosan. Chitosan could cause leakage of cell contents of the bacteria and disrupt the cell wall.
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Cao Y, Zhou YM, Shan Y, Ju HX, Xue XJ. Preparation and characterization of grafted collagen-multiwalled carbon nanotubes composites. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2007; 7:447-51. [PMID: 17450777 DOI: 10.1166/jnn.2007.137] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
This paper describes a new class of composite materials designed by combining multiwalled carbon nanotubes (MWCNTs) and grafted collagen matrix. These materials show high mechanical capabilities by taking advantage of the favorable mechanical characteristics of MWCNTs. Furthermore, doping carbon nanotubes into grafted collagen matrix results in a substantial improvement of thermal stability and infrared emissivity. Thus these materials possess potential applications in some fields such as biomedicine and infrared camouflage.
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Dai C, Mi W, Yang F, Chen B, Ding H, Shan Y. A novel inorganic–organic hybrid material: hydrothermal synthesis and properties of [V6O12(CH3O)4(phen)4·4H2O] (phen = 1,10-phenanthroline). J COORD CHEM 2007. [DOI: 10.1080/00958970500270836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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