Publications by authors named "Alwin Tan"

Intercellular adhesion molecule 1 (ICAM-1) is a central cell adhesion molecule for retinal transendothelial migration of the leukocytes in non-infectious posterior uveitis. Inhibiting gene transcription reduces induction of ICAM-1 in inflamed retinal endothelium. Based on published literature implicating transcription factor ETS-1 as an activator of gene transcription, we investigated the effect of ETS-1 blockade on ICAM-1 levels in cytokine-stimulated human retinal endothelial cells.

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Article Synopsis
  • - The study evaluated the effectiveness and safety of low-dose-rate (LDR) brachytherapy using iodine-125 for young men under 60 with localized low- to intermediate-risk prostate cancer, amid existing concerns among urologists about long-term control and side effects.
  • - A total of 161 patients were analyzed over a median follow-up period of 6.8 years, revealing an impressive biochemical progression-free survival rate of 94% at 8 years and an overall survival rate of 96.9%.
  • - The treatment resulted in minimal severe toxicities, with only 1.9% of patients developing secondary cancers, indicating that LDR brachytherapy could be a highly effective and safe option for younger men diagnosed
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Intercellular adhesion molecule 1 (ICAM-1) is a transmembrane protein in the immunoglobulin superfamily expressed on the surface of multiple cell populations and upregulated by inflammatory stimuli. It mediates cellular adhesive interactions by binding to the β2 integrins macrophage antigen 1 and leukocyte function-associated antigen 1, as well as other ligands. It has important roles in the immune system, including in leukocyte adhesion to the endothelium and transendothelial migration, and at the immunological synapse formed between lymphocytes and antigen-presenting cells.

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The interaction between leukocytes and cytokine-activated retinal endothelium is an initiating step in non-infectious uveitis involving the posterior eye, mediated by cell adhesion molecules. However, because cell adhesion molecules are required for immune surveillance, therapeutic interventions would ideally be employed indirectly. Using 28 primary human retinal endothelial cell isolates, this study sought to identify transcription factor targets for reducing levels of the key retinal endothelial cell adhesion molecule, intercellular adhesion molecule (ICAM)-1, and limiting leukocyte binding to the retinal endothelium.

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Objectives: To report on the usability, safety, symmetry, and effectiveness of hyaluronic acid (HA) injected between the prostate and the rectum for patients undergoing treatment for prostate cancer with external beam radiotherapy (EBRT), and present a novel definition of rectal spacer symmetry that is reproducible and independent of patient anatomy.

Patients And Methods: 102 consecutive patients with clinical stage of T1c-3b prostate cancer underwent general anaesthesia for fiducial marker insertion and injection of HA into the perirectal space before EBRT. HA safety, symmetry, separation, and usability based on user experience were assessed.

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Purpose: To report on rectal dosimetry and toxicity outcomes in men with prostate cancer (PCa) treated with iodine-125 low-dose-rate brachytherapy (LDR-BT) with or without polyethylene glycol hydrogel (HS) or hyaluronic acid (HA) rectal spacer (RS) insertion.

Material And Methods: Seventy consecutive men treated with LDR-BT between December 2017 and July 2019 were included in this study, including twenty-eight (40%) men who had RS insertion according to the preference of referring urologist, compared to a group of forty-two men (60%) without RS. Descriptive statistics were used to compare RS safety, dosimetric effects on organs at risk (rectum and urethra), and gastrointestinal (GI) and genitourinary toxicities (GU) (assessed using the CTCAE v.

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Purpose: The aim of this retrospective study was to investigate the use of a radiopaque tissue fiducial marker (TFM) in the treatment of prostate cancer patients who undergo post-prostatectomy radiotherapy (PPRT). TFM safety, its role and benefit in quantifying the set-up uncertainties in patients undergoing PPRT image-guided radiotherapy were assessed.

Materials And Methods: A total of 45 consecutive PPRT patients underwent transperineal implantation of TFM at the level of vesicourethral anastomosis in the retrovesical tissue prior to intensity-modulated radiotherapy.

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Purpose: To report on rectal dosimetric and toxicity outcomes of intermediate and high-risk prostate cancer patients undergoing combined high-dose-rate (HDR) brachytherapy and external beam radiotherapy (EBRT) with or without hydrogel spacer (HS) insertion.

Material And Methods: A total of 97 patients were analyzed in this study, with 32 patients (33%) who had HS insertion compared with a preceding group of 65 patients (67%) without HS. HS safety, the dosimetric effects on organs at risk (rectal, urethral, penile bulb, and bladder) as well as gastrointestinal (GI) and genitourinary toxicity were evaluated and compared between the two groups.

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Introduction: To examine the long-term outcomes of high dose rate brachytherapy boost (HDR-BT) combined with external beam radiotherapy (EBRT) for intermediate and high-risk prostate cancer patients.

Methods: Data from 95 patients who underwent combined EBRT (50.4 Gy) and HDR-BT to the prostate between 2010 and 2017 were retrospectively analysed.

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Purpose: The purpose of this study was to determine whether the degree of prostate to rectal separation using a hydrogel spacer (HS) and its effect on decreasing rectal dose can be reproduced in the community setting.

Methods: Thirty one patients with cT1-3aN0M0 prostate adenocarcinoma receiving radical radiotherapy to 78 Gy were recruited to the study. The primary endpoint was the proportion of patients achieving at least 25% reduction in volume of rectum receiving 70 Gy (rV70).

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Purpose: To report the 5-year biochemical relapse-free survival (BRFS), overall survival (OS), and long-term toxicity outcomes of patients treated with low-dose-rate (LDR) brachytherapy as monotherapy for low- to intermediate-risk prostate cancer.

Material And Methods: Between 2004 and 2011, 371 patients were treated with LDR brachytherapy as monotherapy. Of these, 102 patients (27%) underwent transurethral resection of the prostate (TURP) prior to implantation.

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Objective: To report on the dosimetric benefits and late toxicity outcomes after injection of hydrogel spacer (HS) between the prostate and rectum for patients treated with prostate radiotherapy (RT).

Patients And Methods: In all, 76 patients with a clinical stage of T1-T3a prostate cancer underwent general anaesthesia for fiducial marker insertion plus injection of the HS into the perirectal space before intensity-modulated RT (IMRT) or volumetric-modulated arc RT (VMAT). HS safety, dosimetric benefits, and the immediate- to long-term effects of gastrointestinal (GI) toxicity were assessed.

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