2,556 research outputs found
A new automatic detection approach for hepatocellular carcinoma using ¹¹C-acetate positron emission tomography
Author name used in this publication: Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information EngineeringRefereed conference paper2003-2004 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Fast system identification algorithm for non-uniformly sampled noisy biomedical signal
Author name used in this publication: Dagan FengVersion of RecordPublishe
Regulation of blood-testis barrier dynamics: An in vivo study
An in vivo model was used to investigate the regulation of tight junction (TJ) dynamics in the testis when adult rats were treated with CdCl2. It was shown that the CdCl2-induced disruption of the blood-testis barrier (BTB) associated with a transient induction in testicular TGF-β2 and TGF-β3 (but not TGF-β1 and the phosphorylated p38 mitogen activated protein (MAP) kinase, concomitant with a loss of occludin and zonula occludens-1 (ZO-1) from the BTB site in the seminiferous epithelium. These results suggest that BTB dynamics in vivo are regulated by TGF-β2/-β3 via the p38 MAP kinase pathway. Indeed, SB202190, a specific p38 MAP kinase inhibitor, blocked the CdCl2-induced occludin and ZO-1 loss from the BTB. This result clearly illustrates that CdCl2 mediates its BTB disruptive effects via the TGF-β3/p38 MAP kinase signaling pathway. Besides, this CdCl2-induced occludin and ZO-1 loss from the BTB also associated with a significant loss of the cadherin/catenin and the nectin/afadin protein complexes at the site of cell-cell actin-based adherens junctions (AJs). An induction of α2-macroglobulin (a non-specific protease inhibitor) was also observed during BTB damage and when the seminiferous epithelium was being depleted of germ cells. These data illustrate that a primary disruption of the BTB can lead to a secondary loss of cell adhesion function at the site of AJs, concomitant with an induction in protease inhibitor, which apparently is used to protect the epithelium from unwanted proteolysis. α2-Macroglobulin was also shown to associate physically with TGF-β3, afadin and nectin 3, but not occludin, E-cadherin or N-cadherin, indicating its possible role in junction restructuring in vivo. Additionally, the use of SB202190 to block the TGF-β3/p-38 MAP kinase pathway also prevented the CdCl2-induced loss of cadherin/catenin and nectin/afadin protein complexes from the AJ sites, yet it had no apparent effect on α2-macroglobulin. These results demonstrate for the first time that the TGF-β3/p38 MAP kinase signaling pathway is being used to regulate both TJ and AJ dynamics in the testis, mediated by the effects of TGF-β3 on TJ- and AJ-integral membrane proteins and adaptors, but not protease inhibitors.published_or_final_versio
Estimation of input function and kinetic parameters using simulated annealing : application in a flow model
Author name used in this publication: Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
A technique for extracting physiological parameters and the required input function simultaneously from PET image measurements : theory and simulation study
Author name used in this publication: Dagan FengVersion of RecordPublishe
Online palmprint identification
Author name used in this publication: Wai-Kin Kong2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Simultaneous estimation of physiological parameters and the input function : in vivo PET data
Author name used in this publication: (David) Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Segmentation of dynamic PET images using cluster analysis
Author name used in this publication: Dagan FengVersion of RecordPublishe
Non-invasive extraction of physiological parameters in quantitative PET studies using simultaneous estimation and cluster analysis
Author name used in this publication: Dagan FengRefereed conference paper2000-2001 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Personalized prediction of EGFR mutation-induced drug resistance in lung cancer
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