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Padmanabhan S.,Nanyang Technological University | Shinoj V.K.,Nanyang Technological University | Murukeshan V.M.,Nanyang Technological University | Padmanabhan P.,Laboratory of Molecular Imaging
Journal of Biomedical Optics | Year: 2010

A simple optical method using hollow-core photonic crystal fiber for protein detection has been described. In this study, estrogen receptor (ER) from a MCF-7 breast carcinoma cell lysates immobilized inside a hollow-core photonic crystal fiber was detected using anti-ER primary antibody with either Alexa ™ Fluor 488 (green fluorescent dye) or 555 (red Fluorescent dye) labeled Goat anti-rabbit IgG as the secondary antibody. The fluorescence fingerprints of the ERα protein were observed under fluorescence microscope, and its optical characteristics were analyzed. The ERα protein detection by this proposed method is based on immuno binding from sample volume as low as 50 nL. This method is expected to offer great potential as a biosensor for medical diagnostics and therapeutics applications. © 2010 Society of Photo-Optical Instrumentation Engineers.

Hendrikse J.,University Utrecht | Petersen E.T.,National Neuroscience Institute | Petersen E.T.,Arhus University Hospital | Chng S.M.,National Neuroscience Institute | And 3 more authors.
Radiology | Year: 2010

Purpose: To investigate the effect of variations in anatomic features of the circle of Willis on the perfusion territory to deep structures, including the nucleus caudatus, the nucleus lentiformis, and the thalamus. Materials and Methods: The ethics committee of the study institution approved the study protocol. A total of 159 patients with first-time clinical symptoms of cerebral ischemia were recruited. Contributions to the perfusion territory were visualized with territorial arterial spin-labeling magnetic resonance (MR) imaging. The anatomic features of the circle of Willis were evaluated with time-of-flight MR angiography. Perfusion territory contributions were compared among circle of Willis variants by using the Cochran-Mantel-Haenszel test. Results: The perfusion territory contributions to the deep-brain structures could be evaluated in 119 of 159 patients (75%). With a fetal-type circle of Willis (41 of 238 hemispheres; 17%), there was a contribution from the ipsilateral internal carotid artery to the thalamus in all 41 hemispheres (100%), compared with 96 of the 197 hemispheres (49%) without a fetal-type circle of Willis. In the 19 patients with a hypoplastic A1 segment, there was more often a contribution of the contralateral internal carotid artery to the perfusion of the nucleus caudatus (10 of 19; 53%) and the nucleus lentiformis (5 of 19; 26%). Conclusion: The perfusion territory contributions to deep-brain structures vary widely. These differences can be partly explained by variations in the anatomic features of the circle of Willis. © RSNA, 2010.

Gandesiri M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Chakilam S.,Friedrich - Alexander - University, Erlangen - Nuremberg | Ivanovska J.,Friedrich - Alexander - University, Erlangen - Nuremberg | Benderska N.,Friedrich - Alexander - University, Erlangen - Nuremberg | And 10 more authors.
Apoptosis | Year: 2012

The histone deacetylase inhibitor (HDACi) LBH589 has been verified as an effective anticancer agent. The identification and characterization of new targets for LBH589 action would further enhance our understanding of the molecular mechanisms involved in HDACi therapy. The role of the tumor suppressor death-associated protein kinase (DAPK) in LBH589-induced cytotoxicity has not been investigated to date. Stable DAPK knockdown (shRNA) and DAPK overexpressing (DAPK+++) cell lines were generated from HCT116 wildtype colon cancer cells. LBH589 inhibited cell proliferation, reduced the long-term survival, and up-regulated and activated DAPK in colorectal cancer cells.Moreover, LBH589 significantly suppressed the growth of colon tumor xenografts and in accordance with the in vitro studies, increased DAPK levels were detected immunohistochemically. LBH589 induced a DAPK-dependent autophagy as assessed by punctuate accumulation of LC3-II, the formation of acidic vesicular organelles, and degradation of p62 protein. LBH589-induced autophagy seems to be predominantly caused by DAPK protein interactions than by its kinase activity. Caspase inhibitor zVAD increased autophagosome formation, decreased the cleavage of caspase 3 and PARP but didn't rescue the cells from LBH589-induced cell death in crystal violet staining suggesting both caspase-dependent as well as caspase-independent apoptosis pathways. Pre-treatment with the autophagy inhibitor Bafilomycin A1 caused caspase 3-mediated apoptosis in a DAPK-dependent manner. Altogether our data suggest that DAPK induces autophagy in response to HDACi-treatment. In autophagy deficient cells, DAPK plays an essential role in committing cells to HDACi induced apoptosis. © Springer Science+Business Media, LLC 2012.

Yuan F.,Jiangxi University of Finance and Economics | Yuan F.,Quantitative Group | Chuang K.-H.,Laboratory of Molecular Imaging | Liu J.,Quantitative Group
IEEE Transactions on Biomedical Engineering | Year: 2013

It is challenging to construct an accurate and smooth mesh for noisy and small n-furcated tube-like structures, such as arteries, veins, and pathological vessels, due to tiny vessel size, noise, n-furcations, and irregular shapes of pathological vessels. We propose a framework by dividing the modeling process into mesh construction and mesh refinement. In the first step, we focus on mesh topological correctness, and just create an initial rough mesh for the n-furcated tube-like structures. In the second step, we propose a variational surface deformation method to push the initial mesh to structure boundaries for positional accuracy improvement. By iteratively solving Euler-Lagrange equations derived from the minimization of the shell and distance energies, the initial mesh can be gradually pushed to the boundaries. A mesh dilation method is proposed to prevent the extremely deviated initial mesh moving toward wrong boundaries. We combine deformation and subdivision to propose a coarse-to-fine modeling framework for the improvement of efficiency and accuracy. Experiments show our method can construct an accurate and smooth mesh for noisy and small n-furcated tube-like structures, and it is useful in hemodynamics, quantitative measurement, and analysis of vessels. © 1964-2012 IEEE.

D'Silva L.,Laboratory of Molecular Imaging | Pola A.,Laboratory of Molecular Imaging | Pola A.,National University of Singapore | Dutta P.,H. Lee Moffitt Cancer Center and Research Institute | And 6 more authors.
Magnetic Resonance in Chemistry | Year: 2012

Longitudinal multispin order (LOMO) corresponds to a nonequilibrium population distribution in spin systems that exhibit scalar (J), dipolar, or quadrupolar coupling. We investigated the relaxation of longitudinal two-spin order (2-LOMO) in systems that had either weakly or strongly J-coupled spins. Our results indicated longer relaxation times for the 2-LOMO state compared with the corresponding longitudinal single-spin state (1-LOMO). Accessing nuclear spin states that have relaxation times longer than T 1, without the use of external contrast agents, is potentially useful for in vivo imaging and also for studying systems using dynamically hyperpolarized nuclear spins where longer life times are sought to increase the time available to study (bio)chemical events. Copyright © 2012 John Wiley & Sons, Ltd.

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