232 research outputs found
BIOMECHANICAL ANALYSIS OF BACK-SOMERSAULT KICKS IN TAEKWONDO
This study was purposed to investigate biomechanical differences between best and worst trials in performing back-somersault kicks in Taekwondo. Six elite members of college Taekwondo demonstration team participated in this study and executed each ten trials of single back-somersault kick and double back-somersault kick, respectively. High speed motion capturing system collected positions of 21 markers on major anatomical locations to obtain motion data of full body segments. After post-processing procedure, results showed that the best trial of back-somersault kicks indicated longer preparation time (countermovement), larger range of motions of hip joint, and higher peak angular velocities of knee and hip joints prior to take-off than those of the worst trial. We concluded that athletes should avoid a quick countermovement before take-off, which induces insufficient strain energy of lower extremities and ground reaction impulse. Therefore, a sufficient time for muscle contractions are required to develop high power
Organic light emitting board for dynamic interactive display
Interactive displays involve the interfacing of a stimuli-responsive sensor with a visual human-readable response. Here, we describe a polymeric electroluminescence-based stimuli-responsive display method that simultaneously detects external stimuli and visualizes the stimulant object. This organic light-emitting board is capable of both sensing and direct visualization of a variety of conductive information. Simultaneous sensing and visualization of the conductive substance is achieved when the conductive object is coupled with the light emissive material layer on application of alternating current. A variety of conductive materials can be detected regardless of their work functions, and thus information written by a conductive pen is clearly visualized, as is a human fingerprint with natural conductivity. Furthermore, we demonstrate that integration of the organic light-emitting board with a fluidic channel readily allows for dynamic monitoring of metallic liquid flow through the channel, which may be suitable for biological detection and imaging applications.
Cystamine induces AIF-mediated apoptosis through glutathione depletion
AbstractCystamine and its reduced form cysteamine showed protective effects in various models of neurodegenerative disease, including Huntington's disease and Parkinson's disease. Other lines of evidence demonstrated the cytotoxic effect of cysteamine on duodenal mucosa leading to ulcer development. However, the mechanism for cystamine cytotoxicity remains poorly understood. Here, we report a new pathway in which cystamine induces apoptosis by targeting apoptosis-inducing factor (AIF). By screening of various cell lines, we observed that cystamine and cysteamine induce cell death in a cell type-specific manner. Comparison between cystamine-sensitive and cystamine-resistant cell lines revealed that cystamine cytotoxicity is not associated with unfolded protein response, reactive oxygen species generation and transglutaminase or caspase activity; rather, it is associated with the ability of cystamine to trigger AIF nuclear translocation. In cystamine-sensitive cells, cystamine suppresses the levels of intracellular glutathione by inhibiting Ξ³-glutamylcysteine synthetase expression that triggers AIF translocation. Conversely, glutathione supplementation completely prevents cystamine-induced AIF translocation and apoptosis. In rats, cysteamine administration induces glutathione depletion and AIF translocation leading to apoptosis of duodenal epithelium. These results indicate that AIF translocation through glutathione depletion is the molecular mechanism of cystamine toxicity, and provide important implications for cystamine in the neurodegenerative disease therapeutics as well as in the regulation of AIF-mediated cell death
Activation of AMP-activated protein kinase stimulates the nuclear localization of glyceraldehyde 3-phosphate dehydrogenase in human diploid fibroblasts
In addition to its well-known glycolytic activity, GAPDH displays multiple functions, such as nuclear RNA export, DNA replication and repair, and apoptotic cell death. This functional diversity depends on its intracellular localization. In this study, we explored the signal transduction pathways involved in the nuclear translocation of GAPDH using confocal laser scanning microscopy of immunostained human diploid fibroblasts (HDFs). GAPDH was present mainly in the cytoplasm when cultured with 10% FBS. Serum depletion by culturing cells in a serum-free medium (SFM) led to a gradual accumulation of GAPDH in the nucleus, and this nuclear accumulation was reversed by the re-addition of serum or growth factors, such as PDGF and lysophosphatidic acid. The nuclear export induced by the re-addition of serum or growth factors was prevented by LY 294002 and SH-5, inhibitors of phosphoinositide 3-kinase (PI3K) and Akt/protein kinase B, respectively, suggesting an involvement of the PI3K signaling pathway in the nuclear export of GAPDH. In addition, 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), an activator of AMP-activated protein kinase (AMPK), stimulated the nuclear translocation of GAPDH and prevented serum- and growth factor-induced GAPDH export. AMPK inhibition by compound C or AMPK depletion by siRNA treatment partially prevented SFM- and AICAR-induced nuclear translocation of GAPDH. Our data suggest that the nuclear translocation of GAPDH might be regulated by the PI3K signaling pathway acting mainly as a nuclear export signal and the AMPK signaling pathway acting as a nuclear import signal.Peairs A, 2009, CLIN EXP IMMUNOL, V156, P542, DOI 10.1111/j.1365-2249.2009.03924.xChen Z, 2009, CIRC RES, V104, P496, DOI 10.1161/CIRCRESAHA.108.187567Cao C, 2008, J BIOL CHEM, V283, P28897, DOI 10.1074/jbc.M804144200Li XX, 2008, ARTERIOSCL THROM VAS, V28, P1789, DOI 10.1161/ATVBAHA.108.172452Lombardi M, 2008, J CELL BIOL, V182, P327Sen N, 2008, NAT CELL BIOL, V10, P866, DOI 10.1038/ncb1747Kim HS, 2008, J BIOL CHEM, V283, P3731, DOI 10.1074/jbc.M704432200Du ZX, 2007, ENDOCRINOLOGY, V148, P4352, DOI 10.1210/en.2006-1511Harada N, 2007, J BIOL CHEM, V282, P22651, DOI 10.1074/jbc.M610724200Goirand F, 2007, J PHYSIOL-LONDON, V581, P1163, DOI 10.1113/jphysiol.2007.132589Barbini L, 2007, MOL CELL BIOCHEM, V300, P19, DOI 10.1007/s11010-006-9341-1Hurley RL, 2006, J BIOL CHEM, V281, P36662, DOI 10.1074/jbc.M606676200Hara MR, 2006, CELL MOL NEUROBIOL, V26, P527, DOI 10.1007/s10571-006-9011-6Tisdale EJ, 2006, J BIOL CHEM, V281, P8436, DOI 10.1074/jbc.M513031200Rattan R, 2005, J BIOL CHEM, V280, P39582, DOI 10.1074/jbc.M507443200Hara MR, 2005, NAT CELL BIOL, V7, P665, DOI 10.1038/ncb1268Sirover MA, 2005, J CELL BIOCHEM, V95, P45, DOI 10.1002/jcb.20399Jones RG, 2005, MOL CELL, V18, P283, DOI 10.1016/j.molcel.2005.03.027Tisdale EJ, 2004, J BIOL CHEM, V279, P54046, DOI 10.1074/jbc.M409472200Hardie DG, 2004, J CELL SCI, V117, P5479, DOI 10.1242/jcs.01540Li J, 2004, AM J PHYSIOL-ENDOC M, V287, pE834, DOI 10.1152/ajpendo.00234.2004Cooray S, 2004, J GEN VIROL, V85, P1065, DOI 10.1099/vir.0.1977-0Brown VM, 2004, J BIOL CHEM, V279, P5984, DOI 10.1074/jbc.M307071200Tisdale EJ, 2003, J BIOL CHEM, V278, P52524, DOI 10.1074/jbc.M309343200HAWLEY SA, 2003, J BIOL, V2, P28Schmitz HD, 2003, CELL BIOL INT, V27, P511, DOI 10.1011/S1065-6995(03)00096-9Tisdale EJ, 2002, J BIOL CHEM, V277, P3334, DOI 10.1074/jbc.M109744200Schmitz HD, 2001, EUR J CELL BIOL, V80, P419Dastoor Z, 2001, J CELL SCI, V114, P1643Yeo EJ, 2000, MOL CELLS, V10, P415Stein SC, 2000, BIOCHEM J, V345, P437Sirover MA, 1999, BBA-PROTEIN STRUCT M, V1432, P159Shashidharan P, 1999, NEUROREPORT, V10, P1149Rameh LE, 1999, J BIOL CHEM, V274, P8347Sawa A, 1997, P NATL ACAD SCI USA, V94, P11669Vincent MF, 1996, BIOCHEM PHARMACOL, V52, P999Reiss N, 1996, BIOCHEM MOL BIOL INT, V38, P711CORTON JM, 1995, EUR J BIOCHEM, V229, P558KAWAMOTO RM, 1986, BIOCHEMISTRY-US, V25, P657BOYCE ST, 1983, J INVEST DERMATOL S, V81, P33
Plasma Cell Granuloma Associated with Pulmonary Actinomycosis: A Case Report
Plasma cell granuloma (PCG) of the lung is a rare disease that usually presents as a pulmonary nodule or mass on incidental radiographic examination without symptoms. Although the etiology of PCG is still controversial, many findings have lent support to the lesion being a reactive inflammatory process rather than a neoplastic one. We describe a 53-yr-old male who presented with a hemoptysis and have a lung mass at the left upper lobe on chest radiograph. The lung mass was primarily diagnosed as PCG by percutaneous needle aspiration and biopsy, and the patient was treated with oral steroid because he and relatives refused the operation. However, the size of the lung mass did not change and open thoracotomy and lobectomy were done therefore. He was confirmed as having pulmonary actinomycosis with PCG after surgery. To our knowledge, this is the first report of PCG associated with actinomycosis in Korea
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TRAIL Enhances Apoptosis of Human Hepatocellular Carcinoma Cells Sensitized by Hepatitis C Virus Infection: Therapeutic Implications
Hepatitis C virus (HCV) infection causes chronic liver diseases leading to hepatocellular carcinoma (HCC) and liver failure. We have previously shown that HCV sensitizes hepatocytes to mitochondrial apoptosis via the TRAIL death receptors DR4 and DR5. Although TRAIL and its receptors are selective targets for cancer therapy, their potential against HCC with chronic HCV infection has not been explored yet. Here we show that HCV induces DR4/DR5-dependent activation of caspase-8 leading to elevation of apoptotic signaling in infected cells and also present TRAIL effect in HCV-induced apoptotic signaling. HCV induced proteolytic cleavage of caspase-9 by stimulating DR4 and DR5, resulting in subsequent cleavage of caspase-3. Further, HCV-induced proteolytic cleavage in caspase-8, caspase-9, and caspase-3 was enhanced in the presence of recombinant TRAIL. HCV-induced cleavage in caspase-9 and increase in caspase-3/7 activity was completely suppressed by silencing of either DR4 or DR5. Perturbing DR4/DR5-caspase-8 signaling complex by silencing DR4 and DR5 or by chemical inhibitor specific to caspase-8 led to decrease of HCV-induced cleavage of poly(ADP-ribose) polymerase (PARP), a substrate for caspase-3 during apoptosis, indicating the functional role of caspase-8 in HCV-induced apoptotic signaling network. Furthermore, TRAIL enhanced PARP cleavage in apoptotic response induced by HCV infection, indicating the effect of TRAIL for the induction of selective apoptosis of HCC cells infected with HCV. Given the importance of apoptosis in HCC development, our data suggest that HCV-induced DR4 and DR5 may be considered as an attractive target for TRAIL therapy against HCC with chronic HCV infection
Effect of emergency medical service use on time interval from symptom onset to hospital admission for definitive care among patients with intracerebral hemorrhage: a multicenter observational study
Objective This study evaluated whether emergency medical service (EMS) use was associated with early arrival and admission for definitive care among intracerebral hemorrhage (ICH) patients. Methods Patients with ICH were enrolled from 29 hospitals between November 2007 and December 2012, excluding those patients with subarachnoid hemorrhage, traumatic ICH, and missing information. The patients were divided into four groups based on visit type to the definitive hospital emergency department (ED): direct visit by EMS (EMS-direct), direct visit without EMS (non-EMS-direct), transferred from a primary hospital by EMS (EMS-transfer), and transferred from a primary hospital without EMS (non-EMS-transfer). The outcomes were the proportions of participants within early (<1 hr) definitive hospital ED arrival from symptom onset (pS2ED) and those within early (<4 hr) admission from symptom onset (pS2AD). Adjusted odds ratios were calculated to determine the association between EMS use and outcomes with and without inter-hospital transfer. Results A total of 6,564 patients were enrolled. The adjusted odds ratios (95% confidence intervals) for pS2ED were 22.95 (17.73β29.72), 1.11 (0.67β1.84), and 7.95 (6.04β10.46) and those for pS2AD were 5.56 (4.70β6.56), 0.96 (0.71β1.30), and 2.35 (1.94β2.84) for the EMS-direct, EMS-transfer, and non-EMS-direct groups compared with the non-EMS-transfer group, respectively. Through the interaction model, EMS use was significantly associated with early arrival and admission among direct visiting patients but not with transferred patients. Conclusion EMS use was significantly associated with shorter time intervals from symptom onset to arrival and admission at a definitive care hospital. However, the effect disappeared when patients were transferred from a primary hospital
Regulation of Tumor Progression by Programmed Necrosis
Rapidly growing malignant tumors frequently encounter hypoxia and nutrient (e.g., glucose) deprivation, which occurs because of insufficient blood supply. This results in necrotic cell death in the core region of solid tumors. Necrotic cells release their cellular cytoplasmic contents into the extracellular space, such as high mobility group box 1 (HMGB1), which is a nonhistone nuclear protein, but acts as a proinflammatory and tumor-promoting cytokine when released by necrotic cells. These released molecules recruit immune and inflammatory cells, which exert tumor-promoting activity by inducing angiogenesis, proliferation, and invasion. Development of a necrotic core in cancer patients is also associated with poor prognosis. Conventionally, necrosis has been thought of as an unregulated process, unlike programmed cell death processes like apoptosis and autophagy. Recently, necrosis has been recognized as a programmed cell death, encompassing processes such as oncosis, necroptosis, and others. Metabolic stress-induced necrosis and its regulatory mechanisms have been poorly investigated until recently. Snail and Dlx-2, EMT-inducing transcription factors, are responsible for metabolic stress-induced necrosis in tumors. Snail and Dlx-2 contribute to tumor progression by promoting necrosis and inducing EMT and oncogenic metabolism. Oncogenic metabolism has been shown to play a role(s) in initiating necrosis. Here, we discuss the molecular mechanisms underlying metabolic stress-induced programmed necrosis that promote tumor progression and aggressiveness
Homozygote CRIM1 variant is associated with thiopurine-induced neutropenia in leukemic patients with both wildtype NUDT15 and TPMT
Abstract
Background
NUDT15 and TPMT variants are strong genetic determinants of thiopurine-induced hematological toxicity that results in therapeutic failure in pediatric acute lymphoblastic leukemia (ALL). However, many patients with both wild-type (WT) NUDT15 and TPMT still suffer from thiopurine toxicity and therapeutic failure.
Methods
Whole-exome sequencing was done for discovery (Nβ=β244) and replication (Nβ=β76) cohorts. Age- and sex-adjusted multiple regression analyses of both WT patients were performed to identify (pβ<β0.01, Nβ=β188 for discovery) and validate (pβ<β0.05, Nβ=β52 for replication) candidate variants for the tolerated last-cycle 6-mercaptopurine (6-MP) dose intensity percentage (DIP). Both independent and additive effects of the candidate variants on well-known NUDT15 and TPMT were evaluated by multigene prediction models.
Results
Among the 12 candidate variants from the discovery phase, the rs3821169 variant of the gene encoding Cysteine-Rich Transmembrane BMP Regulator 1 (CRIM1) was successfully replicated (pβ<β0.05). It showed high interethnic variability with an impressively high allele frequency in East Asians (Tβ=β0.255) compared to Africans (0.001), Americans (0.02), Europeans (0.009), and South Asians (0.05). Homozygote carriers of the CRIM1 rs3821169 variant (Nβ=β12, 5%) showed significantly lower last-cycle 6-MP DIPs in the discovery, replication, and combined cohorts (pβ=β0.025, 0.013, and 0.001, respectively). The traditional two-gene model (NUDT15 and TPMT) for predicting 6-MP DIP <β25% was outperformed by the three-gene model that included CRIM1, in terms of the area under the receiver operating characteristic curve (0.734 vs. 0.665), prediction accuracy (0.759 vs. 0.756), sensitivity (0.636 vs. 0.523), positive predictive value (0.315 vs. 0.288), and negative predictive value (0.931 vs. 0.913).
Conclusions
The CRIM1 rs3821169 variant is suggested to be an independent and/or additive genetic determinant of thiopurine toxicity beyond NUDT15 and TPMT in pediatric ALL
Serum Levels of Advanced Glycation End Products Are Associated with In-Stent Restenosis in Diabetic Patients
The formation of advanced glycation end products (AGEs), in various tissues has been known to enhance immunoinflammatory reactions and local oxidant stresses in long standing diabetes. Recently, AGEs have been reported to play a role in neointimal formation in animal models of arterial injury. We attempted to determine whether the serum levels of AGEs are associated with coronary restenosis in diabetic patients. Blood samples were collected from diabetic patients with coronary artery disease undergoing stent implantation and the serum levels of AGEs were analyzed by the fluorescent intensity method. The development of in-stent restenosis (ISR) was evaluated by a 6-month follow-up coronary angiography. A total of 263 target lesions were evaluated, in 203 patients. The ISR rate in the high-AGE (>170 U/ml) group (40.1%) was significantly higher than in the low-AGE group (β€170 U/ml) (19.6%) (p<0.001). Furthermore, multivariate analysis revealed that a high level of serum AGEs is an independent risk factor for the development of ISR (odds ratio, 2.659; 95% CI, 1.431-4.940; p=0.002). The serum levels of AGEs constitute an excellent predictive factor for ISR, and should be one of the guidelines for medical therapy and interventional strategy to prevent ISR in diabetic patients
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