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Cheng L, Chan WK, Peng Y, Qin H. Towards data-driven tele-medicine intelligence: community-based mental healthcare paradigm shift for smart aging amid COVID-19 pandemic. Health Inf Sci Syst 2023; 11:14. [PMID: 36923686 PMCID: PMC10011761 DOI: 10.1007/s13755-022-00198-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 10/06/2022] [Indexed: 03/18/2023] Open
Abstract
Purpose Telemedicine are experiencing an unprecedented boom globally since the beginning of the COVID-19 pandemic. As the most vulnerable groups amid COVID-19, the digital delivery of healthcare poses great challenges to the elderly population, caregiver, health service providers, and health policy makers. To bridge the service delivery gaps between the telemedicine demand side and supply side, explore evidence-based approach for integrated care, address challenges for aging policy, and build foundation for the development of data-driven and community-based telemedicine, our R&D team applied translational research to design and develop telemedicine "SMART" for enhancing elderly mental health wellbeing amid COVID-19. Our aim is to investigate the preparedness mechanisms of mental health disease including response, intervention, and connection these three healthcare delivery pipelines with the collection, consolidation, and synergy of heath parameters and social determinants, using data analytics approach to achieve Evidence-Based Medicine (EBM). Methods A mix of quantitative and qualitative research design for scientifically rigorous consultation and analysis was conducted from Jan 2020 to June 2021 in Hong Kong. An exploratory and descriptive qualitative design was used in this study. The data were collected through focus group discussions conducted from elderly and their caregivers living in 10 main districts of Hong Kong. Our research pilot tested "SMART" targeting for elderly with mental health improvement needs. Baseline questionnaire with 110 tele-medicine product users includes questions on demographic information, self-rated mental health digital adoption. The follow-up five focus group discussions with 57 users (elderly and their caregivers) further explore the social determinants of telemedicine transformation and help propose the integrated telemedicine paradigm shift framework establishment, development, and enhancement. Results Grounded on the baseline needs assessment and feedbacks collected, it is evident that multi-dimensional health information from the four various streams (community, clinic, home, remote) and customized digital health solutions are playing a key role in addressing elderly mental health digital service needs and bridging digital divide. The designed tele-medicine product lines up health service provider (supplier side) and elderly specific needs (demand side) with our three-level design, enables elderly and their families to follow and control their own health management and connect with the service provider, community of practice (CoP), and health policy makers. Conclusion It's beneficial to involve elderly and gerontechnology stakeholders as part of Community-Based Participatory Research (CBPR) before and throughout the developing and delivery phases an integrated and age-friendly digital intervention. The challenges in applying and disseminating telemedicine reflected by the elderly and caregivers can be used as important input for further development and indicators for the sustainable and integrated elderly primary care framework. Supplementary Information The online version contains supplementary material available at 10.1007/s13755-022-00198-4.
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Affiliation(s)
- Lan Cheng
- Big Data Bio-Intelligence Lab, Big Data Institute, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - WK Chan
- Department of Computer Science and Engineering, Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - Yi Peng
- School of Government, Nanjing University, Nanjing, China
| | - Harry Qin
- Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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Xiong R, Shao D, Do S, Chan WK. Activation of Chaperone-Mediated Autophagy Inhibits the Aryl Hydrocarbon Receptor Function by Degrading This Receptor in Human Lung Epithelial Carcinoma A549 Cells. Int J Mol Sci 2023; 24:15116. [PMID: 37894798 PMCID: PMC10606571 DOI: 10.3390/ijms242015116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/07/2023] [Accepted: 10/08/2023] [Indexed: 10/29/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor and a substrate protein of a Cullin 4B E3 ligase complex responsible for diverse cellular processes. In the lung, this receptor is responsible for the bioactivation of benzo[a]pyrene during tumorigenesis. Realizing that the AHR function is affected by its expression level, we are interested in the degradation mechanism of AHR in the lung. Here, we have investigated the mechanism responsible for AHR degradation using human lung epithelial A549 cells. We have observed that the AHR protein levels increase in the presence of chloroquine (CQ), an autophagy inhibitor, in a dose-dependent manner. Treatment with 6-aminonicotinamide (6-AN), a chaperone-mediated autophagy (CMA) activator, decreases AHR protein levels in a concentration-dependent and time-dependent manner. This decrease suppresses the ligand-dependent activation of the AHR target gene transcription, and can be reversed by CQ but not MG132. Knockdown of lysosome-associated membrane protein 2 (LAMP2), but not autophagy-related 5 (ATG5), suppresses the chloroquine-mediated increase in the AHR protein. AHR is resistant to CMA when its CMA motif is mutated. Suppression of the epithelial-to-mesenchymal transition in A549 cells is observed when the AHR gene is knocked out or the AHR protein level is reduced by 6-AN. Collectively, we have provided evidence supporting that AHR is continuously undergoing CMA and activation of CMA suppresses the AHR function in A549 cells.
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Affiliation(s)
| | | | | | - William K. Chan
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA 95211, USA; (R.X.); (D.S.); (S.D.)
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Fung CK, Chow C, Chan WK, Choi EWK, To KF, Chan JKC, Cheuk W. Spindle cell/sclerosing rhabdomyosarcoma with DCTN1::ALK fusion: broadening the molecular spectrum with potential therapeutic implications. Virchows Arch 2022; 480:927-932. [PMID: 35229187 DOI: 10.1007/s00428-022-03305-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/17/2022] [Accepted: 02/20/2022] [Indexed: 12/20/2022]
Abstract
Spindle cell/sclerosing rbabdomyosarcoma (RMS) is a recently characterized variant of RMS with several distinct molecular subtypes. We describe an example occurring in the tongue of a 10-year-old boy with a novel DCTN1::ALK fusion. The tumor exhibited infiltrative growth and was comprised of fascicles and focally whorls of spindle cells with eosinophilic cytoplasm, in a collagenous or myxoid stroma. Moderate cytologic atypia, mitotic activity (2/10 HPFs), and perineural invasion were identified. The tumor cells expressed actin, desmin, MyoD1, myogenin, and ALK. An in-frame fusion between DCTN1 exon 26 and ALK exon 20 was detected by RNA sequencing, which was confirmed by split reads and supported by FISH studies. The tumor showed an indolent behavior with local recurrence 3 years after excision. This study broadens the molecular spectrum of spindle cell/sclerosing RMS and this molecular aberration may represent a potential therapeutic target for unresectable or disseminated disease.
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Affiliation(s)
- C K Fung
- Department of Pathology, United Christian Hospital, Kwun Tong, Hong Kong
| | - Chit Chow
- Department of Cellular and Anatomical Pathology, Chinese University of Hong Kong, Shatin, Hong Kong
| | - W K Chan
- Department of Pathology, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong
| | - Eric W K Choi
- Department of Pathology, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong
| | - K F To
- Department of Cellular and Anatomical Pathology, Chinese University of Hong Kong, Shatin, Hong Kong
| | - John K C Chan
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong, SAR, China
| | - Wah Cheuk
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong, SAR, China.
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Yang Y, Chan WK. Glycogen Synthase Kinase 3 Beta Regulates the Human Aryl Hydrocarbon Receptor Cellular Content and Activity. Int J Mol Sci 2021; 22:ijms22116097. [PMID: 34198826 PMCID: PMC8201391 DOI: 10.3390/ijms22116097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/21/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a cytosolic receptor which is involved in diverse cellular events in humans. The most well-characterized function of AHR is its ability to upregulate gene transcription after exposure to its ligands, such as environmental toxicants, dietary antioxidants, drugs, and endogenous ligands. The cellular content of AHR is partly controlled by its degradation via the ubiquitin–proteasome system and the lysosome-dependent autophagy. We used human cervical cancer (HeLa) cells to investigate how AHR undergoes protein degradation and how its activity is modulated. Since the glycogen synthase kinase 3 beta (GSK3β)-mediated phosphorylation can trigger protein degradation and substrates of GSK3β contain stretches of serine/threonine residues which can be found in AHR, we examined whether degradation and activity of AHR can be controlled by GSK3β. We observed that AHR undergoes the GSK3β-dependent, LC3-mediated lysosomal degradation without ligand treatment. The AHR can be phosphorylated in a GSK3β-dependent manner at three putative sites (S436/S440/S444, S689/S693/T697, and S723/S727/T731), which leads to lysosomal degradation of the AHR protein. Inhibition of the GSK3β activity suppresses the ligand-activated transcription of an AHR target gene in HeLa, human liver cancer (Hep3B), and human breast cancer (MCF-7) cells. Collectively, our findings support that phosphorylation of AHR by GSK3β is essential for the optimal activation of its target gene transcription and this phosphorylation may partake as an “off” switch by subjecting the receptor to lysosomal degradation.
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Khan HR, Chan WK, Kanawati J, Yee R. A case report of inappropriate inhibition of ventricular pacing due to a unique pacemaker electrogram storage feature. Eur Heart J Case Rep 2021; 5:ytab096. [PMID: 33768197 PMCID: PMC7980079 DOI: 10.1093/ehjcr/ytab096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/27/2020] [Accepted: 02/25/2021] [Indexed: 12/02/2022]
Abstract
Background Modern permanent pacemakers (PPMs) have individual features designed to identify cardiac rhythm abnormalities and improve their performance. Inappropriate pacing inhibition may be an undesired outcome from these features and cause symptoms in patients who require frequent pacing, leading to dizziness, and syncope. Inappropriate inhibition can be difficult to identify in circumstances that are intermittent and difficult to reproduce. Case summary A 57-year-old female underwent a mitral valve replacement (MVR) for severe mitral stenosis. One month following MVR, she presented with symptomatic third-degree atrioventricular block, and a dual-chamber PPM (Advisa™, Medtronic, Minneapolis, USA) was implanted and programmed DDD 50–130 b.p.m. At the 3-month follow-up, she reported frequent episodes of lightheadedness. She was found to have intermittent ventricular pacing inhibition on a 48-h Holter monitor due to an internal function of the Advisa™ series of PPMs that attempts to store an electrogram (EGM) every 1 h and 30 s. During the EGM storage, an amplified signal from the storage capacitor can result in oversensing by the ventricular channel and inappropriate pacing inhibition. Discussion To rectify the issue, the ventricular lead sensitivity value was increased from 0.9 mV to 1.2 mV. No instances of inappropriate ventricular pacing inhibition were noted on follow-up. To our knowledge, this is a rare case of inappropriate ventricular pacing inhibition caused by a combination of PPM self-adjusting sensitivity algorithm and oversensing every 1 h and 30 s from an amplified storage capacitor. Physicians should be aware of this possible complication and differentiate it from device or lead malfunction.
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Affiliation(s)
- Habib R Khan
- London Health Sciences Centre, University of Western Ontario, 339 Windermere Road, London, ON N6A 5A5, Canada
| | - William K Chan
- London Health Sciences Centre, University of Western Ontario, 339 Windermere Road, London, ON N6A 5A5, Canada
| | - Juliana Kanawati
- London Health Sciences Centre, University of Western Ontario, 339 Windermere Road, London, ON N6A 5A5, Canada
| | - Raymond Yee
- London Health Sciences Centre, University of Western Ontario, 339 Windermere Road, London, ON N6A 5A5, Canada
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Karuthan SR, Koh PS, Chinna K, Chan WK. Barcelona Clinic Liver Cancer and Hong Kong Liver Cancer staging systems for prediction of survival among Hepatocellular Carcinoma patients. Med J Malaysia 2021; 76:199-204. [PMID: 33742628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
INTRODUCTION We aimed to compare the Barcelona Clinic Liver Cancer (BCLC) and Hong Kong Liver Cancer (HKLC) staging systems. MATERIALS AND METHODS This is a retrospective study on patients with newly diagnosed hepatocellular carcinoma (HCC) at the University Malaya Medical Centre between 2011 and 2014. Survival times were analysed using the Kaplan- Meier procedure and comparison between groups was done using the log rank test. RESULTS The data of 190 patients was analysed. Chronic hepatitis B was the most common aetiology for HCC (43.7%), but a large proportion was cryptogenic or non-alcoholic steatohepatitis-related (41.6%). Only 11.1% were diagnosed early (BCLC Stage 0-A) while majority were diagnosed at an intermediate stage (BCLC Stage B, 53.7%). The median survival rate was significantly different between the different groups when either of the staging systems was used (p<0.05 for all comparisons). However, the two staging systems lacked agreement (weighted kappa 0.519, 95%CI: 0.449, 0.589) with significant difference in median survival rates between BCLC Stage A and HKLC Stage 2, and between BCLC Stage C and HKLC Stage 4. CONCLUSION Both staging systems were able to stratify patients according to survival, but they only had moderate agreement with significant differences observed in two groups of the staging systems.
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Affiliation(s)
- S R Karuthan
- University Malaya, Faculty of Medicine, Department of Medicine, Kuala Lumpur, Malaysia
| | - P S Koh
- University Malaya, Faculty of Surgery, Department of Medicine, Kuala Lumpur, Malaysia
| | - K Chinna
- Taylor's University, Faculty of Health and Medical Sciences, School of Medicine, Kuala Lumpur, Malaysia
| | - W K Chan
- University Malaya, Faculty of Medicine, Department of Medicine, Department of Medicine, Kuala Lumpur, Malaysia.
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Chan WK, Skanes A, Klein GJ. V‐A‐A‐V response to ventricular entrainment: What is the mechanism of this SVT? J Cardiovasc Electrophysiol 2020; 31:3028-3030. [DOI: 10.1111/jce.14759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 09/16/2020] [Accepted: 09/20/2020] [Indexed: 11/28/2022]
Affiliation(s)
- William K. Chan
- Arrhythmia Service University Hospital, University of Western Ontario, London Health Sciences Centre London Ontario Canada
| | - Allan Skanes
- Arrhythmia Service University Hospital, University of Western Ontario, London Health Sciences Centre London Ontario Canada
| | - George J. Klein
- Arrhythmia Service University Hospital, University of Western Ontario, London Health Sciences Centre London Ontario Canada
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Kanawati J, Roberts JD, Rowe MK, Khan H, Chan WK, Leong-Sit P, Manlucu J, Yee R, Tang AS, Gula LJ, Skanes AC, Klein GJ. A simple maneuver to determine if septal accessory pathway ablation requires a left atrial approach. J Cardiovasc Electrophysiol 2020; 31:3207-3214. [PMID: 32936492 DOI: 10.1111/jce.14745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/04/2020] [Accepted: 09/11/2020] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Septal accessory pathway (AP) ablation can be challenging due to the complex anatomy of the septal region. The decision to access the left atrium (LA) is often made after failure of ablation from the right. We sought to establish whether the difference between ventriculo-atrial (VA) time during right ventricular (RV) apical pacing versus the VA during tachycardia would help establish the successful site for ablation of septal APs. METHODS Intracardiac electrograms of patients with orthodromic reciprocating tachycardia (ORT) using a septal AP with successful catheter ablation were reviewed. The ∆VA was the difference between the VA interval during RV apical pacing and the VA interval during ORT. The difference in the VA interval during right ventricular entrainment and ORT (StimA-VA) was also measured. RESULTS The median ∆VA time was significantly less in patients with a septal AP ablated on the right side compared with patients with a septal AP ablated on the left side (12 ± 19 vs. 56 ± 10 ms, p < .001). The StimA-VA was significantly different between the two groups (22 ± 14 vs. 53 ± 9 ms, p < .001). The ∆VA and StimA-VA were always ≤ 40 ms in patients with non-decremental septal APs ablated from the right side and always greater than 40 ms in those with septal APs ablated from the left. CONCLUSION ΔVA and StimA-VA values identified with RV apical pacing in the setting of ORT involving a septal AP predict when left atrial access will be necessary for successful ablation.
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Affiliation(s)
- Juliana Kanawati
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Cardiology, Concord Repatriation General Hospital, Sydney, New South Wale, Australia
| | - Jason D Roberts
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Matthew K Rowe
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Habib Khan
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - William K Chan
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Peter Leong-Sit
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jaimie Manlucu
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Raymond Yee
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Anthony S Tang
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Lorne J Gula
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Allan C Skanes
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - George J Klein
- Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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Yang Y, Chan WK. p23 Co‐chaperone Protects Aryl Hydrocarbon Receptor (AHR) from the Autophagy‐Mediated Degradation. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.03688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lo C, Chan WK, Lo G. Atypical Langerhans Cell Histiocytosis: A Case Report. Hong Kong Journal of Radiology 2020. [DOI: 10.12809/hkjr2016914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- C Lo
- Department of Radiology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - WK Chan
- Department of Pathology, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong
| | - G Lo
- Department of Radiology, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong
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Kuan PX, Chan WK, Chua PF, Yeo J, Sapri FE, Bujang MA, Said A. Lifestyle factors associated with cardiovascular risk among healthcare workers from the tertiary hospitals in Sarawak. Malays Fam Physician 2020; 15:15-22. [PMID: 32284800 PMCID: PMC7136671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
INTRODUCTION A cross-sectional study is used to evaluate the lifestyle factors associated with cardiovascular disease (CVD) risk among healthcare workers in tertiary hospitals in Sarawak, Malaysia. METHODS A questionnaire-based survey using the Simple Lifestyle Indicator Questionnaire (SLIQ) was administered to, and anthropometric measurements were collected from, 494 healthcare workers. RESULTS The mean age of the subjects was 32.4±8.4, with a range of 19 to 59 years. The subjects were from the allied health (45.5%), management and professional (25.1%) and executive (29.4%) fields. Overall, 47.4% of the subjects were of normal weight, 30.2% were overweight, 17.2% were obese and 5.2% were underweight. The mean number of working hours per week for the subjects was 47.6±14.0 with the highest working hours found among the management and professional group, followed by the executive and allied health groups. Overall, 39.7% of the healthcare workers worked office hours, 36.6% worked within the shift system, 20.9% worked office hours and were on-call and the remaining 2.8% worked a mixture of office hours and shifts. Based on the SLIQ score, 58.1% were classified as at intermediate risk for CVD, 38.5% were in the healthy category and 3.4% were in the unhealthy category. Factors associated with a healthier lifestyle were being female (Odds Ratio [OR]= 12.1; CI=3.2-46.4), professional (mean score= 6.70), in the allied health group (mean score=7.33) and in the normal BMI group (OR= 9.3, CI= 1.8-47.0). CONCLUSION In our study, healthcare workers had an intermediate risk of developing CVD in the future. Thus, there is a need to intervene in the lifestyle factors contributing to CVD.
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Affiliation(s)
- P X Kuan
- Clinical Research Centre (CRC) Sungai Buloh Hospital, Jalan Hospital 47000 Selangor, Malaysia
| | - W K Chan
- Department of Anaesthesiology and Intensive Care, Sarawak General Hospital, Jalan Hospital, 93586 Kuching, Sarawak, Malaysia
| | - P F Chua
- Department of Paraclinical Science Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, Malaysia
| | - Jjp Yeo
- Department of Cardiology, Sarawak General Hospital Heart Centre, Jalan Lingkaran Luar Kuching, 94300 Kota Samarahan, Sarawak, Malaysia
| | - F E Sapri
- Clinical Research Centre, Sarawak General Hospital, Jalan Hospital 93586 Kuching, Sarawak, Malaysia
| | - M A Bujang
- Clinical Research Centre, Sarawak General Hospital, Jalan Hospital, 93586 Kuching, Sarawak, Malaysia
| | - A Said
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, 94300 Kota Samarahan Sarawak, Malaysia
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Chen J, Yakkundi P, Chan WK. Down-Regulation of p23 in Normal Lung Epithelial Cells Reduces Toxicities From Exposure to Benzo[a]pyrene and Cigarette Smoke Condensate via an Aryl Hydrocarbon Receptor-Dependent Mechanism. Toxicol Sci 2019; 167:239-248. [PMID: 30204910 DOI: 10.1093/toxsci/kfy234] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated signaling molecule which controls tumor growth and metastasis, T cell differentiation, and liver development. Expression levels of this receptor protein is sensitive to the cellular p23 protein levels in immortalized cancer cell lines. As little as 30% reduction of the p23 cellular content can suppress the AHR function. Here we reported that down-regulation of the p23 protein content in normal, untransformed human bronchial/tracheal epithelial cells to 48% of its content also suppresses the AHR protein levels to 54% of its content. This p23-mediated suppression of AHR is responsible for the suppression of (1) the ligand-dependent induction of the cyp1a1 gene transcription; (2) the benzo[a]pyrene- or cigarette smoke condensate-induced CYP1A1 enzyme activity, and (3) the benzo[a]pyrene and cigarette smoke condensate-mediated production of reactive oxygen species. Reduction of the p23 content does not alter expression of oxidative stress genes and production of PGE2. Down regulation of p23 suppresses the AHR protein levels in two other untransformed cell types, namely human breast MCF-10A and mouse immune regulatory Tr1 cells. Collectively, down-regulation of p23 suppresses the AHR protein levels in normal and untransformed cells and can in principle protect our lung epithelial cells from AHR-dependent oxidative damage caused by exposure to agents from environment and cigarette smoking.
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Affiliation(s)
- Jinyun Chen
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, California 95211
| | - Poonam Yakkundi
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, California 95211
| | - William K Chan
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, California 95211
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Yakkundi P, Gonsalves E, Galou-Lameyer M, Selby MJ, Chan WK. Aryl hydrocarbon receptor acts as a tumor suppressor in a syngeneic MC38 colon carcinoma tumor model. Hypoxia (Auckl) 2019; 7:1-16. [PMID: 31119183 PMCID: PMC6498092 DOI: 10.2147/hp.s196301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 02/18/2019] [Indexed: 12/15/2022]
Abstract
Background: Aryl hydrocarbon receptor (AHR), commonly known as an environmental sensor involved in the metabolism and elimination of xenobiotic substances, is also an important modulator in the development and functioning of the immune system. AHR expression is varied in the T cell subsets with the highest expression in T-helper 17 and T regulatory cells. It has been reported that AHR can act as a tumor promoter or a tumor suppressor, depending on the tumor type. Methods: In an effort to understand the role played by AHR in tumor growth, the MC38 syngeneic colon carcinoma tumor model was used on C57BL/6 or ahr knockout (KO, -/-) mice with or without AHR antagonist (CH223191) treatment. Tumor sizes were measured, and biomarkers were quantified in tumor microenvironment and draining lymph nodes using flow cytometry. Enzyme-linked immunosorbent assay was used to determine the amount of cytokines in tumors. Results: In ahr deficient mice, MC38 tumors progress more rapidly than in wild-type mice, accompanied by an increase in tumor-associated macrophages and M2 macrophages and a decrease in CD8a positive cytotoxic lymphocytes. Analysis of cytokines in the tumor microenvironment reveals a pro-inflammatory phenotype. Similar changes were observed by pharmacologic blockade of the receptor using CH223191. Conclusion: AHR acts as a tumor suppressor in mice implanted with MC38 colon carcinoma cells as evidenced by either a blockade or deficiency of AHR.
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Affiliation(s)
- Poonam Yakkundi
- Animal Biology Group, Bristol-Myers Squibb Company, Redwood City, CA, 94063, USA
| | - Eleanor Gonsalves
- Animal Biology Group, Bristol-Myers Squibb Company, Redwood City, CA, 94063, USA
| | - Maria Galou-Lameyer
- Animal Biology Group, Bristol-Myers Squibb Company, Redwood City, CA, 94063, USA
| | - Mark J Selby
- Immuno-Oncology Group, Bristol-Myers Squibb Company, Redwood City, CA, 94063, USA
| | - William K Chan
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, 95211, USA
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Li Y, Park MS, Chan WK, Livesey J, Zhou Z. Effect of Rutaecarpine on the Benzo(a)pyrene‐Induced DNA Damage
In Vitro. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.672.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- You Li
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - Miki S. Park
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - William K. Chan
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - John Livesey
- Department of Physiology and PharmacologyUniversity of the PacificStocktonCA
| | - Zhu Zhou
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
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Chan CK, Wong KH, Lee MP, Chan KC, Leung CC, Leung EC, Chan WK, Mak IK. Risk factors associated with 1-year mortality among patients with HIV-associated tuberculosis in areas with intermediate tuberculosis burden and low HIV prevalence. Hong Kong Med J 2019; 24:473-483. [PMID: 30262675 DOI: 10.12809/hkmj187303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Data are limited regarding risk factors for mortality among patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB) in areas with low HIV prevalence and intermediate TB burden, such as the Western Pacific region. This study aimed to assess such risk factors in Hong Kong, which has an intermediate TB burden and low HIV prevalence. METHODS We conducted a retrospective cohort analysis of adult patients reported to the Hong Kong TB-HIV Registry between 2006 and 2015. Baseline characteristics were compared with Kaplan-Meier estimates. Cox proportional hazards regression modelling was used to identify factors associated with mortality. RESULTS Of 299 patients studied, 21 (7.0%) died within 12 months of anti-TB treatment (median [interquartile range], 7.5 [3.8-10] months). The median age of death was 54 (interquartile range, 40.5-75.0) years. The cause of death was TB in five and unrelated to TB in the remaining 16. Cox proportional hazards regression showed that older age (adjusted hazard ratio=4.5; 95% confidence interval [CI]=1.4-14.9), history of drug addiction (4.6; 95% CI=1.6-13.0), and low baseline CD4 cell count of <50/μL (2.9; 95% CI=1.1-7.7) were independent risk factors for death within 12 months. CONCLUSION This study complements previous studies by providing information regarding risk factors associated with mortality among patients with HIV-associated TB in areas with intermediate TB burden and low HIV prevalence. The results from our study may guide targeted measures to improve survival in other areas with intermediate TB burden and low HIV prevalence, such as the Western Pacific region.
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Affiliation(s)
- C K Chan
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - K H Wong
- Head Office, Centre for Health Protection, Department of Health, Hong Kong
| | - M P Lee
- Department of Medicine, Queen Elizabeth Hospital, Hospital Authority, Hong Kong
| | - K Cw Chan
- Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong
| | - C C Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - E Cc Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - W K Chan
- Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong
| | - I Ky Mak
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
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Singh SM, Chan WK, Danon A. What Is the Value of Continuous Monitoring Post-Transcatheter Aortic Valve Replacement? JACC Cardiovasc Interv 2018; 11:2235. [PMID: 30409284 DOI: 10.1016/j.jcin.2018.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/21/2018] [Indexed: 11/20/2022]
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17
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Luo G, Gu YZ, Jain S, Chan WK, Carr KM, Hogenesch JB, Bradfield CA. Molecular characterization of the murine Hif-1 alpha locus. Gene Expr 2018; 6:287-99. [PMID: 9368100 PMCID: PMC6148284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypoxia inducible factor 1 alpha (HIF-1 alpha) is a basic helix-loop-helix-PAS (bHLH-PAS) transcription factor that mediates certain cellular responses to low oxygen tension, iron chelators, Co2+, Ni2+, Mg2+, and low intracellular glucose concentration. Upon exposure to the above conditions, HIF-1 alpha is upregulated and heterodimerizes with the Ah receptor nuclear translocator (ARNT, also known as HIF-1 beta), the heterodimeric complex binds TACGTG-containing genomic enhancer elements, and activates transcription of target genes. As a first step in developing genetic models to study the biology related to cellular hypoxia, we have cloned the murine HIF-1 alpha cDNA, determined the tissue-specific expression of its mRNA, functionally analyzed its protein product, and characterized its promoter and its genomic structure. A comparison between the murine and human HIF-1 alpha protein sequence reveals 95%, 99%, and 83% identity in the bHLH, PAS, and variable domains, respectively. RNAse protection assays demonstrate that in adult mice, the mHIF-1 alpha mRNA is expressed at high levels in kidney, heart, brain, thymus, and placenta, with moderate expression in liver, spleen, testis, and lung and much lower expression in skeletal muscle testis. Northern blot analysis indicates that the mRNA of the murine HIF-1 alpha is transcribed in two forms, a major 4-kb species and a minor 5-kb species; both are present in all tissues examined. The Hif-1 alpha promoter is GC rich, does not have a TATA element near its transcriptional start site, and does not respond to hypoxia or Co2+. The mHIF-1 alpha structural gene is composed of 15 exons. The splice junction sites within the bHLH and the PAS domains of HIF-1 alpha gene are highly conserved with respect to a number of previously characterized members of the bHLH-PAS superfamily. However, unlike other bHLH-PAS genes, where the variable domain is encoded by 2 exons, the variable region of the mHIF-1 alpha gene is encoded by 7 exons. Furthermore, most of these splice junction sites in the variable region are conserved with that of HIF-2 alpha, a recently cloned hypoxia-responsive bHLH-PAS protein (also known as MOP2, EPAS1, and HLF). These data suggest that HIF-1 alpha, along with HIF-2 alpha, represents a new subclass of the bHLH-PAS superfamily.
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Affiliation(s)
- Gang Luo
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School
| | - Yi-Zhong Gu
- McArdle Laboratory for Cancer Research, University of Wisconsin Medical School
| | - Sanjay Jain
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School
| | - William K. Chan
- Department of Pharmaceutics and Medicinal Chemistry, School of Pharmacy, University of the Pacific
| | - Kristen M. Carr
- McArdle Laboratory for Cancer Research, University of Wisconsin Medical School
| | - John B. Hogenesch
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School
| | - Christopher A. Bradfield
- McArdle Laboratory for Cancer Research, University of Wisconsin Medical School
- Address correspondence to Christopher A. Bradfield, Ph.D., McArdle Laboratory for Cancer Research, 1400 University Avenue, Madison, WI 53706. Tel: (608) 262-2024; Fax: (608) 262-2824; E-mail:
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Chan WK, Danon A, Wijeysundera HC, Singh SM. Single Versus Dual Lead Atrioventricular Sequential Pacing for Acquired Atrioventricular Block During Transcatheter Aortic Valve Implantation Procedures. Am J Cardiol 2018; 122:633-637. [PMID: 30205889 DOI: 10.1016/j.amjcard.2018.04.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 11/25/2022]
Abstract
Atrioventricular block (AVB) after transcatheter aortic valve implantation (TAVI) is common. Pacing platforms that preserve atrioventricular (AV) synchrony may be beneficial in these patients. Single lead AV sequential pacemakers (VDD) allow AV synchrony and, by virtue of implanting a single lead, can be advantageous when compared with traditional dual lead (DDD) pacemakers. The objective of this retrospective case-controlled study was to compare the strategy of AV sequential pacing with a VDD versus DDD pacemaker in consecutive TAVI patients (n = 120) with acquired AVB. Patients were classified as receiving a VDD (n = 73) or DDD (n = 47) pacemaker. Procedure characteristics, complications, and the need for long-term ventricular pacing reported. Pacemaker implantation time (51 vs 66 minutes and p <0.001), fluoroscopy time (3.7 vs 7.8 minutes and p = 0.004), and radiation exposure (dose area product: 6.5 vs 15.3 mGy/cm2 and p = 0.006) were lower in patients receiving VDD pacemakers. Procedural complications were similar in the 2 groups. Overall, 59% of the cohort required ≥50% ventricular pacing at 1-year follow-up. In conclusion, VDD pacemaker implantation was associated with shorter procedure times, lower radiation exposure, and similar safety outcomes when compared with DDD pacemaker implantation in TAVI patients with acquired AVB.
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Chan WK, Yeoh KY, Lim CY, Lai SM, Lee JL, Leow AHR, Goh KL. Hepatitis B virus infection among children of hepatitis B surface antigen positive mothers in a Malaysian hospital. Med J Malaysia 2018; 73:137-140. [PMID: 29962496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
INTRODUCTION There have been no published data on the transmission of hepatitis B virus (HBV) infection among children of hepatitis B surface antigen (HBsAg) positive mothers in Malaysia. METHODS This is a cross-sectional study of all the children of HBsAg-positive mothers who delivered at the University of Malaya Medical Centre between 1993 and 2000. RESULTS A total of 60 HBsAg-positive mothers and their 154 children participated in the study. HBsAg was detected in four children (2.6%) while IgG antibody to the hepatitis B core antigen (anti-HBc IgG) was detected in seventeen children (11.0%). The mother's age at childbirth was significantly lower in the children with detectable HBsAg (22.5±6.1 years vs. 29.7±4.5 years, p=0.043) and anti-HBc IgG (26.6±6.1 years vs. 30.0±4.3 years, p=0.004). Children born in the 1980s were significantly more likely to have detectable HBsAg (18.8% vs. 0.7%, p=0.004) and anti-HBc IgG (37.5% vs. 8.0%, p=0.000) compared with those born later. All children with detectable HBsAg were born via spontaneous vaginal delivery, and hepatitis B immunoglobulin was either not given or the administration status was unknown. The majority of mothers with chronic HBV infection (70.4%) were not under any regular follow-up for their chronic HBV infection and the main reason was the lack of awareness of the need to do so (47.4%). CONCLUSION Transmission of HBV infection among children of HBsAg-positive mothers in Malaysia is low. However, attention needs to be given to the high rate of HBsAgpositive mothers who are not on any regular follow-up.
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Affiliation(s)
- W K Chan
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia.
| | - K Y Yeoh
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
| | - C Y Lim
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
| | - S M Lai
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
| | - J L Lee
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
| | - A H R Leow
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
| | - K L Goh
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
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Yang Y, Chan WK. Glycogen Synthase Kinase‐3β Modulation of Basal Aryl Hydrocarbon Receptor Protein Levels in HeLa Cells. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.826.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yujie Yang
- Department of Pharmaceutics and Medicinal ChemistryThomas J. Long School of Pharmacy and Health SciencesUniversity of the PacificStocktonCA
| | - William K. Chan
- Department of Pharmaceutics and Medicinal ChemistryThomas J. Long School of Pharmacy and Health SciencesUniversity of the PacificStocktonCA
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Chen J, Yakkundi P, Chan WK. p23 Modulates Aryl Hydrocarbon Receptor Protein Levels in Normal Cell Lines. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.692.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jinyun Chen
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - Poonam Yakkundi
- Bristol Myers SquibbRedwood CityCA
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - William K. Chan
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
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Abstract
A healthy 28-year-old man presented with multiple brief episodes of convulsion. He was found to have ventricular fibrillation which required defibrillation in the emergency department. After exclusion of organic heart diseases, Brugada syndrome was diagnosed and required implantable cardioverter defibrillator (ICD) implantation. The case emphasized the recognition of malignant cardiac dysrrhythmias as a cause for seizures. The management in the emergency department was discussed.
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23
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Koh KC, Islam M, Chan WK, Lee WY, Ho YW, Alsagoff SAH, Yusof RA. Missed opportunities for earlier HIV-testing in patients with HIV infection referred to a tertiary hospital, a cross-sectional study. Med J Malaysia 2017; 72:209-214. [PMID: 28889131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
INTRODUCTION In Malaysia, the prevalence of missed opportunities for HIV-testing is unknown. Missed opportunities have been linked to late diagnosis of HIV and poorer outcome for patients. We describe missed opportunities for earlier HIV-testing in newly-HIV-diagnosed patients. METHODS Cross sectional study. Adult patients diagnosed with HIV infection and had at least one medical encounter in a primary healthcare setting during three years prior to diagnosis were included. We collected data on sociodemographic characteristics, patient characteristics at diagnosis, HIV-related conditions and whether they were subjected to risk assessment and offered HIV testing during the three years prior to HIV diagnosis. RESULTS 65 newly HIV-diagnosed patients (male: 92.3%; Malays: 52.4%; single: 66.7%; heterosexual: 41%; homosexual 24.6%; CD4 <350 at diagnosis: 63%). 93.8% were unaware of their HIV status at diagnosis. Up to 56.9% had presented with HIV-related conditions at a primary healthcare facility during the three years prior to diagnosis. Slightly more than half were had risk assessment done and only 33.8% were offered HIV-testing. CONCLUSIONS Missed opportunities for HIV-testing was unacceptably high with insufficient risk assessment and offering of HIV-testing. Risk assessment must be promoted and primary care physicians must be trained to recognize HIV-related conditions that will prompt them to offer HIVtesting.
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Affiliation(s)
- K C Koh
- International Medical University, Department of Medicine, Seremban, Negeri Sembilan, Malaysia.
| | - M Islam
- International Medical University, Department of Medicine, Seremban, Negeri Sembilan, Malaysia
| | - W K Chan
- International Medical University, Department of Medicine, Seremban, Negeri Sembilan, Malaysia
| | - W Y Lee
- International Medical University, Department of Medicine, Seremban, Negeri Sembilan, Malaysia
| | - Y W Ho
- International Medical University, Department of Medicine, Seremban, Negeri Sembilan, Malaysia
| | - S A H Alsagoff
- International Medical University, Department of Medicine, Seremban, Negeri Sembilan, Malaysia
| | - R A Yusof
- Hospital Tuanku Ja'afar, Department of Medicine, Seremban, Negeri Sembilan, Malaysia
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Abstract
This paper presents a comparison of manufacturing techniques used in the development of an axial blood pump impeller. In this development process the impeller was designed and its performance was evaluated with the aid of computational fluid dynamics (CFD). Prototypes of those designs where the CFD results show promise were needed in sufficient quantities at a low cost for experimental validation of the CFD results. As the impeller is less than 16 mm in diameter with a maximum blade thickness of about 1.5 mm, innovative manufacturing techniques are explored in this paper to determine the best process for quick fabrication of prototypes that are dimensionally accurate, structurally robust and low in cost. Four rapid prototyping techniques were explored. The completed parts were compared on the basis of manufacturing time, quality and strength of parts obtained, manufacturing cost and also in vitro performances. Based on these studies, it was concluded that selective laser sintering (SLS) is the most appropriate method for the quick production of prototype parts for evaluation of pump performance.
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Affiliation(s)
- W K Chan
- School of Mechanical and Production Engineering, Thermal and Fluids Engineering Division, Nanyang Technological University, Singapore, Singapore
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Liong CC, Ravindran S, Gnana Kumar G, Chin EF, Koh PS, Chan WK. Enteropathy-associated T-cell lymphoma: An extremely rare cause of chronic diarrhoea. Med J Malaysia 2016; 71:88-90. [PMID: 27326953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Chronic diarrhoea in tropical countries may be due to a myriad of causes from infective to non-infective. This case report illustrates the challenges faced in the investigation of a middle-age Chinese gentleman who presented with chronic diarrhoea and weight loss. The diagnosis of type II enteropathy-associated T-cell lymphoma (EATL) was finally made. The diagnosis of EATL was least suspected as the condition is almost unheard of in this part of the world. The epidemiology, presentation, diagnosis, management and prognosis of this rare condition are discussed.
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Affiliation(s)
- C C Liong
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia.
| | - S Ravindran
- University of Malaya, Faculty of Medicine, Department of Pathology, Kuala Lumpur, Malaysia
| | - G Gnana Kumar
- University of Malaya, Faculty of Medicine, Department of Biomedical Imaging, Kuala Lumpur, Malaysia
| | - E F Chin
- University of Malaya, Faculty of Medicine, Department of Medicine, Hematology Unit, Kuala Lumpur, Malaysia
| | - P S Koh
- University of Malaya, Faculty of Medicine, Department of Surgery, Kuala Lumpur, Malaysia
| | - W K Chan
- University of Malaya, Faculty of Medicine, Department of Medicine, Gastroenterology and Hepatology Unit, Kuala Lumpur, Malaysia
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Ren L, Thompson JD, Cheung M, Ngo K, Sung S, Leong S, Chan WK. Selective suppression of the human aryl hydrocarbon receptor function can be mediated through binding interference at the C-terminal half of the receptor. Biochem Pharmacol 2016; 107:91-100. [PMID: 26970402 DOI: 10.1016/j.bcp.2016.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 03/07/2016] [Indexed: 11/26/2022]
Abstract
The human aryl hydrocarbon receptor is a cytosolic signaling molecule which affects immune response and aberrant cell growth. Canonical signaling of the receptor requires the recruitment of coactivators to the promoter region to remodel local chromatin structure. We predicted that interference of this recruitment would block the aryl hydrocarbon receptor function. To prove that, we employed phage display to identify nine peptides of twelve-amino-acid in length which target the C-terminal half of the human aryl hydrocarbon receptor, including the region where coactivators bind. Eight 12mer peptides, in the form of GFP fusion, suppressed the ligand-dependent transcription of six AHR target genes (cyp1a1, cyp1a2, cyp1b1, ugt1a1, nqo1, and ahrr) in different patterns in Hep3B cells, whereas the AHR antagonist CH-223191 suppressed all these target genes similarly. Three of the 12mer peptides (namely 11-3, 1-7, and 7-3) suppressed the 3MC-induced, CYP1A1-dependent EROD activity and the ROS production caused by benzo[a]pyrene. These 12mer peptides suppressed the AHR function synergistically with CH-223191. In conclusion, we provide evidence that targeting the C-terminal half of the human aryl hydrocarbon receptor is a viable, new approach to selectively block the receptor function.
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Affiliation(s)
- Lina Ren
- Harbin Center for Disease Control and Prevention, Harbin, China
| | - John D Thompson
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Michael Cheung
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Katherine Ngo
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Sarah Sung
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - Scott Leong
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States
| | - William K Chan
- Department of Pharmaceutics & Medicinal Chemistry, Thomas J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA 95211, United States.
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Chan WK, Goodman SG, Brieger D, Fox KAA, Gale CP, Chew DP, Udell JA, Lopez-Sendon J, Huynh T, Yan RT, Singh SM, Yan AT. Clinical Characteristics, Management, and Outcomes of Acute Coronary Syndrome in Patients With Right Bundle Branch Block on Presentation. Am J Cardiol 2016; 117:754-9. [PMID: 26762726 DOI: 10.1016/j.amjcard.2015.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/01/2015] [Accepted: 12/01/2015] [Indexed: 12/22/2022]
Abstract
We examined the relations between right bundle branch block (RBBB) and clinical characteristics, management, and outcomes among a broad spectrum of patients with acute coronary syndrome (ACS). Admission electrocardiograms of patients enrolled in the Global Registry of Acute Coronary Events (GRACE) electrocardiogram substudy and the Canadian ACS Registry I were analyzed independently at a blinded core laboratory. We performed multivariable logistic regression analysis to assess the independent prognostic significance of admission RBBB on in-hospital and 6-month mortality. Of 11,830 eligible patients with ACS (mean age 65; 66% non-ST-elevation ACS), 5% had RBBB. RBBB on admission was associated with older age, male sex, more cardiovascular risk factors, worse Killip class, and higher GRACE risk score (all p <0.01). Patients with RBBB less frequently received in-hospital cardiac catheterization, coronary revascularization, or reperfusion therapy (all p <0.05). The RBBB group had higher unadjusted in-hospital (8.8% vs 3.8%, p <0.001) and 6-month mortality rates (15.1% vs 7.6%, p <0.001). After adjusting for established prognostic factors in the GRACE risk score, RBBB was a significant independent predictor of in-hospital death (odds ratio 1.45, 95% CI 1.02 to 2.07, p = 0.039), but not cumulative 6-month mortality (odds ratio 1.29, 95% CI 0.95 to 1.74, p = 0.098). There was no significant interaction between RBBB and the type of ACS for either in-hospital or 6-month mortality (both p >0.50). In conclusion, across a spectrum of ACS, RBBB was associated with preexisting cardiovascular disease, high-risk clinical features, fewer cardiac interventions, and worse unadjusted outcomes. After adjusting for components of the GRACE risk score, RBBB was a significant independent predictor of early mortality.
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Affiliation(s)
- William K Chan
- Terrence Donnelly Heart Centre, Department of Medicine, St Michael's Hospital, Toronto, Canada; University of Toronto, Toronto, Canada
| | - Shaun G Goodman
- Terrence Donnelly Heart Centre, Department of Medicine, St Michael's Hospital, Toronto, Canada; University of Toronto, Toronto, Canada; Canadian Heart Research Centre, Toronto, Canada
| | - David Brieger
- Coronary Care Unit, Concord Hospital, Sydney, Australia
| | - Keith A A Fox
- Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Chris P Gale
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
| | - Derek P Chew
- Department of Cardiovascular Medicine, Department of Cardiovascular Medicine Flinders University, Adelaide, South Australia, Australia
| | - Jacob A Udell
- University of Toronto, Toronto, Canada; Women's College Hospital, Toronto, Canada
| | | | - Thao Huynh
- McGill University Health Centre, McGill University, Montreal, Canada
| | | | - Sheldon M Singh
- University of Toronto, Toronto, Canada; Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Andrew T Yan
- Terrence Donnelly Heart Centre, Department of Medicine, St Michael's Hospital, Toronto, Canada; University of Toronto, Toronto, Canada.
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Triplett BM, Shook DR, Eldridge P, Li Y, Kang G, Dallas M, Hartford C, Srinivasan A, Chan WK, Suwannasaen D, Inaba H, Merchant TE, Pui CH, Leung W. Erratum: Rapid memory T-cell reconstitution recapitulating CD45RA-depleted haploidentical transplant graft content in patients with hematologic malignancies. Bone Marrow Transplant 2015; 50:1012. [DOI: 10.1038/bmt.2015.139] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Malla R, Wang Y, Chan WK, Tiwari AK, Faridi JS. Genetic ablation of PRAS40 improves glucose homeostasis via linking the AKT and mTOR pathways. Biochem Pharmacol 2015; 96:65-75. [PMID: 25931147 DOI: 10.1016/j.bcp.2015.04.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 04/23/2015] [Indexed: 12/22/2022]
Abstract
Alterations in PI3K-AKT-mTOR signaling have been implicated in diabetes. This study assessed whether disruption of PRAS40, a substrate of AKT and component of mTORC1, would alter glucose homeostasis and prevent hyperglycemia in the streptozotocin (STZ)-induced diabetes mouse model. PRAS40 ablation resulted in a mild lowering of blood glucose levels and glycated hemoglobin (HbA1C), a lowered insulin requirement, and improved glucose tolerance in untreated PRAS40 gene knockout (PRAS40(-/-)) as compared to wild-type (PRAS40(+/+)) mice. Diabetes was then induced in these mice using STZ at 50mg/kg/day over five days. Following STZ-treatment, PRAS40(-/-) mice exhibited significantly lower blood glucose and HbA1C levels than PRAS40(+/+) mice. Liver tissue of PRAS40(-/-) mice and shPRAS40 Hep3B cells showed increased activation of AKT (p-AKT T308) and mTORC1 (p-p70S6K) signaling as well as decreased p-AKT (S473) and increased p-IRS1 (S612) protein levels. Altered tissue gene expression of several glucose transporters (GLUT) and increased hepatic GLUT4 protein levels were observed in PRAS40(-/-) as compared to PRAS40(+/+) mice. In summary, PRAS40 deletion significantly attenuates hyperglycemia in STZ-induced PRAS40(-/-) mice through increased hepatic AKT and mTORC1 signaling, a lowered serum insulin requirement, and altered hepatic GLUT4 levels.
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Affiliation(s)
- Ritu Malla
- Department of Physiology and Pharmacology, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States
| | - Yu Wang
- Department of Pharmaceutics and Medicinal Chemistry, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States
| | - William K Chan
- Department of Pharmaceutics and Medicinal Chemistry, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States
| | - Amit K Tiwari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, OH, United States
| | - Jesika S Faridi
- Department of Physiology and Pharmacology, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States.
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Abstract
OBJECTIVE To understand legislation combating counterfeit drugs in Hong Kong. DESIGN This study consisted of two parts. In part I, counterfeit drugs–related ordinances and court cases were reviewed. In part II, indepth interviews of the stakeholders were described. SETTING Hong Kong. PARTICIPANTS All Hong Kong ordinances were screened manually to identify those combating counterfeit drugs. Court cases were searched for each of the identified cases. Then, the relevant judgement justifications were analysed to identify sentencing issues. Indepth interviews with the stakeholders were conducted to understand their perceptions about such legislation. RESULTS Trade Marks Ordinance, Patents Ordinance, Trade Descriptions Ordinance, and Pharmacy and Poisons Ordinance were current legislative items combating counterfeit drugs. Sentencing criteria depended on: intention to deceive, quantity of seized drugs, presence of expected therapeutic effect or toxic ingredients, previous criminal records, cooperativeness with Customs officers, honest confessions, pleas of guilty, types of drugs, and precautionary measures to prevent sale of counterfeit drugs. Stakeholders’ perceptions were explored with respect to legislation regarding the scale and significance of the counterfeit drug problem, penalties and deterrents, drug-specific legislation and authority, and inspections and enforcement. CONCLUSIONS To plug the loopholes, a specific law with heavy penalties should be adopted. This could be supplemented by non-legal measures like education of judges, lawyers, and the public; publishing the names of offending pharmacies; and emphasising the role of pharmacists to the public.
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Affiliation(s)
- C W Lai
- The Jockey Club School of Public Health and Primary Care, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
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Gao X, Bhattacharya S, Chan WK, Jasti BR, Upadrashta B, Li X. Expression of P-glycoprotein and CYP3A4 along the porcine oral-gastrointestinal tract: implications on oral mucosal drug delivery. Drug Dev Ind Pharm 2014; 40:599-603. [DOI: 10.3109/03639045.2014.884118] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Xie J, Huang X, Park MS, Pham HM, Chan WK. Differential suppression of the aryl hydrocarbon receptor nuclear translocator-dependent function by an aryl hydrocarbon receptor PAS-A-derived inhibitory molecule. Biochem Pharmacol 2014; 88:253-65. [PMID: 24486526 DOI: 10.1016/j.bcp.2014.01.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/16/2014] [Accepted: 01/16/2014] [Indexed: 10/25/2022]
Abstract
The aryl hydrocarbon receptor (AhR) heterodimerizes with the aryl hydrocarbon receptor nuclear translocator (Arnt) for transcriptional regulation. We generated three N-terminal deletion constructs of the human AhR of 12-24 kDa in size--namely D1, D2, and D3--to suppress the Arnt function. We observed that all three deletions interact with the human Arnt with similar affinities. D2, which contains part of the AhR PAS-A domain and interacts with the PAS-A domain of Arnt, inhibits the formation of the AhR gel shift complex. D2 suppresses the 3-methylcholanthrene-induced, dioxin response element (DRE)-driven luciferase activity in Hep3B cells and exogenous Arnt reverses this D2 suppression. D2 suppresses the induction of CYP1A1 at both the message and protein levels in Hep3B cells; however, the CYP1B1 induction is not affected. D2 suppresses the recruitment of Arnt to the cyp1a1 promoter but not to the cyp1b1 promoter, partly because the AhR/Arnt heterodimer binds better to the cyp1b1 DRE than to the cyp1a1 DRE. Interestingly, D2 has no effect on the cobalt chloride-induced, hypoxia inducible factor-1 (HIF-1)-dependent expression of vegf, aldolase c, and ldh-a messages. Our data reveal that the flanking sequences of the DRE contribute to the binding affinity of the AhR/Arnt heterodimer to its endogenous enhancers and the function of AhR and HIF-1 can be differentially suppressed by the D2 inhibitory molecule.
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Affiliation(s)
- Jinghang Xie
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Xin Huang
- Department of Pharmacy, Qianfoshan Hospital of Shandong University, Jinan, Shandong, 250014, China
| | - Miki S Park
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Hang M Pham
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - William K Chan
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA.
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Abstract
The title complexes were doped into polycarbonate matrices together with triphenylamine, a hole-transport compound, in order to study their photosensitizing properties. Complexes based on 1 exhibited strong absorption in the visible spectrum due to the presence of a metal-ligand charge-transfer transition and were able to enhance the sensitivity in this region; the best enhancement was found when Ar is a p-flurophenyl group.
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Affiliation(s)
- L S Lam
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong
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Lin AWC, Chan KCW, Chan WK, Wong KH. Authors' reply. Hong Kong Med J 2013; 19:561. [PMID: 24310668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Affiliation(s)
- Ada W C Lin
- Special Preventive Programme, Centre for Health Protection, Department of Health, Kowloon Bay Health Centre, 9 Kai Yan Road, Kowloon Bay, Kowloon, Hong Kong
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Luk JKH, Chan WK, Ng WC, Chiu PKC, Ho C, Chan TC, Chan FHW. Mortality and health services utilisation among older people with advanced cognitive impairment living in residential care homes. Hong Kong Med J 2013; 19:518-24. [PMID: 24096360 DOI: 10.12809/hkmj133951] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To study the demography, clinical characteristics, service utilisation, mortality, and predictors of mortality in older residential care home residents with advanced cognitive impairment. DESIGN Cohort longitudinal study. SETTING Residential care homes for the elderly in Hong Kong West. PARTICIPANTS Residents of such homes aged 65 years or more with advanced cognitive impairment. RESULTS In all, 312 such residential care home residents (71 men and 241 women) were studied. Their mean age was 88 (standard deviation, 8) years and their mean Barthel Index 20 score was 1.5 (standard deviation, 2.0). In all, 164 (53%) were receiving enteral feeding. Nearly all of them had urinary and bowel incontinence. Apart from Community Geriatric Assessment Team clinics, 119 (38%) of the residents attended other clinics outside their residential care homes. In all, 107 (34%) died within 1 year; those who died within 1 year used significantly more emergency and hospital services (P<0.001), and utilised more services from community care nurses for wound care (P=0.001), enteral feeding tube care (P=0.018), and urinary catheter care (P<0.001). Independent risk factors for 1-year mortality were active pressure sores (P=0.0037), enteral feeding (P=0.008), having a urinary catheter (P=0.0036), and suffering from chronic obstructive pulmonary disease (P=0.011). A history of pneumococcal vaccination was protective with respect to 1-year mortality (P=0.004). CONCLUSION Residents of residential care homes for the elderly with advanced cognitive impairment were frail, exhibited multiple co-morbidities and high mortality. They were frequent users of out-patient, emergency, and in-patient services. The development of end-of-life care services in residential care homes for the elderly is an important need for this group of elderly.
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Affiliation(s)
- James K H Luk
- Department of Medicine and Geriatrics, Fung Yiu King Hospital, 9 Sandy Bay Road, Pokfulam, Hong Kong
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Chan CK, Wong KH, Leung CC, Tam CM, Chan KCW, Pang KW, Chan WK, Mak IKY. Treatment outcomes after early initiation of antiretroviral therapy for human immunodeficiency virus-associated tuberculosis. Hong Kong Med J 2013; 19:474-83. [PMID: 23926173 DOI: 10.12809/hkmj133937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the optimal timing for initiating antiretroviral therapy in patients with human immunodeficiency virus (HIV)-associated tuberculosis in Hong Kong. DESIGN Historical cohort. SETTING. Tuberculosis and Chest Service and Special Preventive Programme, Public Health Service Branch, Centre for Health Protection, Department of Health, Hong Kong. PATIENTS Consecutive patients with HIV-associated tuberculosis in a territory-wide TB-HIV registry encountered from 1996 to 2009. RESULTS Of the 260 antiretroviral therapy-naïve patients with HIV-associated tuberculosis, 32 (12%) had antiretroviral therapy initiated within 2 months after starting anti-tuberculosis treatment (early antiretroviral therapy). Early antiretroviral therapy was associated with a more favourable outcome (cure or treatment completion without relapse) at 24 months (91% vs 67%; P=0.007) than those with antiretroviral therapy started later or not initiated, and remained an independent predictor of a favourable outcome after adjustment for potential confounders. Adverse effects from anti-tuberculosis drugs tended to occur more frequently in patients with early antiretroviral therapy (13/32 or 41%) compared with the remainder (59/228 or 26%; P=0.08). A significantly higher proportion of patients in the former group experienced immune reconstitution inflammatory syndrome than in the latter group (7/32 or 22% vs 9/228 or 4%; P<0.001). There was no death attributable to immune reconstitution inflammatory syndrome. CONCLUSIONS Early initiation of antiretroviral therapy is associated with more favourable tuberculosis treatment outcomes in patients with HIV-associated tuberculosis with a low CD4 count (<200/µL). Drug co-toxicity and immune reconstitution inflammatory syndrome that may be increased by earlier initiation of antiretroviral therapy does not undermine tuberculosis treatment outcomes to a significant extent.
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Affiliation(s)
- C K Chan
- Tuberculosis and Chest Service, Public Health Service Branch, Centre for Health Protection, Department of Health, Hong Kong
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Lin AWC, Chan KCW, Chan WK, Wong KH. Tuberculin sensitivity testing and treatment of latent tuberculosis remains effective for tuberculosis control in human immunodeficiency virus-infected patients in Hong Kong. Hong Kong Med J 2013; 19:386-92. [PMID: 23926172 DOI: 10.12809/hkmj133892] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate whether a policy to treat latent tuberculosis identified by annual tuberculin sensitivity testing is effective for tuberculosis control in human immunodeficiency virus-infected patients in Hong Kong. DESIGN Historical cohort study. SETTING Integrated Treatment Centre, Department of Health, Hong Kong. PATIENTS Patients infected with human immunodeficiency virus without a history of tuberculosis were offered annual tuberculin sensitivity testing, coupled with treatment of latent tuberculosis if they tested positive. All such patients were followed for new tuberculosis. RESULTS In all, 1154 patients on antiretroviral therapy, contributing to 5587 patient-years of observation, were analysed; 1032 patients (89%) received annual tuberculin sensitivity testing. Their baseline characteristics, including CD4 counts and other risk factors for tuberculosis, did not differ significantly from those who declined testing. The overall incidence rate of tuberculosis was 0.59 case per 100 patient-years. It was lower in those who received annual tuberculin sensitivity testing than those who did not (0.41 vs 3.85 per 100 patient-years; P<0.0001). Only a low baseline CD4 count and a history of tuberculin sensitivity testing were shown to be significant indicators of incident tuberculosis using multivariate analysis. The hazard ratio was 0.36 (95% confidence interval, 0.16-0.85; P=0.02) for those with a baseline CD4 count of 100/mm3 or above, and 0.26 (95% confidence interval, 0.08-0.77; P=0.016) for those who received annual tuberculin sensitivity testing. The incidence of tuberculosis was highest within 90 days of antiretroviral therapy initiation. CONCLUSION The established policy continues to be effective. The high risk of tuberculosis during the early period of antiretroviral therapy supports early use of tuberculin sensitivity testing. Alternatively, the strategy of universal isoniazid preventive therapy at antiretroviral therapy initiation could be studied for those with very low baseline CD4 counts.
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Affiliation(s)
- A W C Lin
- Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong
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Lin AWC, Wong KH, Chan K, Chan WK. Accelerating prevention of mother-to-child transmission of HIV: ten-year experience of universal antenatal HIV testing programme in a low HIV prevalence setting in Hong Kong. AIDS Care 2013; 26:169-75. [PMID: 23869699 DOI: 10.1080/09540121.2013.819402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Hong Kong has a low prevalence of HIV infection at less than 0.01%. Universal Antenatal HIV Testing Programme (UATP) was launched in all public antenatal units in September 2001. In 2008, voluntary rapid HIV testing was introduced in all public labour units to fill up the gap for pregnant women without HIV testing during the antenatal period. This study evaluated the performance of UATP and rapid HIV testing with indicators. From September 2001 to December 2011, process and outcome indicators for monitoring and evaluation were collected from the service providers in the form of monthly return of workload statistics and case-based statistics of each identified HIV-positive pregnancy via reporting forms. A total of 479,160 antenatal HIV tests and 2,675 rapid tests were performed in the study period. The acceptance rate for UATP and rapid HIV testing was 98% and 80.4% respectively. With the implementation of rapid HIV testing in January 2008, the proportion of pregnant women with HIV status discerned before delivery increased from 84.9% in 2006 to over 99.5% since 2008. The HIV prevalence in UATP and rapid HIV testing was 0.02% and 0.1% respectively. Fifty-three (68%) out of 78 HIV-infected pregnant women identified from the programme have delivered locally. Forty-three (81%) of them delivered by caesarean section and 50 (94%) of them were given antiretrovirals for intervention. Only three children born before the implementation of rapid HIV testing were HIV-infected. In conclusion, UATP and its rapid HIV testing component have been highly accepted and effective in the prevention of perinatal HIV transmission in Hong Kong.
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Affiliation(s)
- Ada W C Lin
- a Special Preventive Programme, Department of Health , Centre for Health Protection , Hong Kong , China
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Wang Y, Thompson JD, Chan WK. A cell-penetrating peptide suppresses the hypoxia inducible factor-1 function by binding to the helix-loop-helix domain of the aryl hydrocarbon receptor nuclear translocator. Chem Biol Interact 2013; 203:401-11. [PMID: 23454269 DOI: 10.1016/j.cbi.2013.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 01/21/2013] [Accepted: 02/19/2013] [Indexed: 12/27/2022]
Abstract
The heterodimeric hypoxia inducible factor-1 (HIF-1) complex is composed of the hypoxia inducible factor-1 alpha (HIF-1α) and the aryl hydrocarbon receptor nuclear translocator (ARNT). Activation of the HIF-1 function is essential for tumor growth and metastasis. We previously showed that transfection of a plasmid containing an ARNT-interacting peptide (Ainp1) cDNA suppresses the HIF-1 signaling in Hep3B cells. Here we generated TAT fusion of the Ainp1 peptide (6His-TAT-Ainp1) to determine whether and how the Ainp1 peptide suppresses the HIF-1 function. The bacterially expressed 6His-TAT-Ainp1 was purified under denatured condition and then refolded by limited dialysis. The refolded 6His-TAT-Ainp1 interacts with the helix-loop-helix (HLH) domain of ARNT in a similar fashion as the native 6His-Ainp1. 6His-TAT-Ainp1 colocalizes with ARNT in the nucleus of HeLa and Hep3B cells after protein transduction. The transduced protein reaches the maximum intracellular levels within 2 h while remains detectable up to 96 h in HeLa cells. At 2 μM concentration, 6His-TAT-Ainp1 is not cytotoxic in HeLa cells but suppresses the cobalt chloride-activated, hypoxia responsive enhancer-driven luciferase expression in a dose-dependent manner. In addition, it decreases the cobalt chloride-dependent induction of the HIF-1 target genes at both the message (vascular endothelial growth factor and aldolase C) and protein (carbonic anhydrase IX and glucose transporter 1) levels. The protein levels of HIF-1α and ARNT are not altered in the presence of 6His-TAT-Ainp1. In summary, we provided evidence to support that the Ainp1 peptide directly suppresses the HIF-1 function by interacting with the ARNT HLH domain, and in turn interfering with the heterodimerization of HIF-1α and ARNT.
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Affiliation(s)
- Yu Wang
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA
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Chan WK, Redelmeier DA. Authors' reply. Am J Cardiol 2013; 111:303-4. [PMID: 23290603 DOI: 10.1016/j.amjcard.2012.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 09/05/2012] [Indexed: 11/17/2022]
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Leung YH, Chan CMN, Ng AMC, Chan HT, Chiang MWL, Djurišić AB, Ng YH, Jim WY, Guo MY, Leung FCC, Chan WK, Au DTW. Antibacterial activity of ZnO nanoparticles with a modified surface under ambient illumination. Nanotechnology 2012; 23:475703. [PMID: 23103840 DOI: 10.1088/0957-4484/23/47/475703] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In various practical applications, nanomaterials typically have functionalized surfaces. Yet, the studies of toxicity and antibacterial activity of functionalized nanoparticles are scarce. We investigated the effect of surface modifications on antibacterial activity of ZnO under ambient illumination, and we found that nanoparticles coated with different surface modifying reagents could exhibit higher or lower toxicity compared to bare ZnO, depending on the surface modifying reagent used. Different surface modifying reagent molecules resulted in differences in the release of Zn(2+) ions and the production of reactive oxygen species (ROS). However, the antibacterial activity did not correlate with the ROS levels or the Zn(2+) ion release. One of the surface-modified ZnO samples exhibited significantly lower Zn(2+) ion release while at the same time exhibiting improved antibacterial activity. In all cases, damage of the cell wall membranes and/or changes in the membrane permeability have been observed, together with the changes in ATR-FTIR spectra indicating differences in protein conformation. Mechanisms of antibacterial activity are discussed.
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Affiliation(s)
- Y H Leung
- Department of Physics, The University of Hong Kong, Hong Kong
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Nguyen LS, Jolly L, Shoubridge C, Chan WK, Huang L, Laumonnier F, Raynaud M, Hackett A, Field M, Rodriguez J, Srivastava AK, Lee Y, Long R, Addington AM, Rapoport JL, Suren S, Hahn CN, Gamble J, Wilkinson MF, Corbett MA, Gecz J. Transcriptome profiling of UPF3B/NMD-deficient lymphoblastoid cells from patients with various forms of intellectual disability. Mol Psychiatry 2012; 17:1103-15. [PMID: 22182939 PMCID: PMC4281019 DOI: 10.1038/mp.2011.163] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/27/2011] [Accepted: 10/24/2011] [Indexed: 11/09/2022]
Abstract
The nonsense-mediated mRNA decay (NMD) pathway was originally discovered by virtue of its ability to rapidly degrade aberrant mRNAs with premature termination codons. More recently, it was shown that NMD also directly regulates subsets of normal transcripts, suggesting that NMD has roles in normal biological processes. Indeed, several NMD factors have been shown to regulate neurological events (for example, neurogenesis and synaptic plasticity) in numerous vertebrate species. In man, mutations in the NMD factor gene UPF3B, which disrupts a branch of the NMD pathway, cause various forms of intellectual disability (ID). Using Epstein Barr virus-immortalized B cells, also known as lymphoblastoid cell lines (LCLs), from ID patients that have loss-of-function mutations in UPF3B, we investigated the genome-wide consequences of compromised NMD and the role of NMD in neuronal development and function. We found that ~5% of the human transcriptome is impacted in UPF3B patients. The UPF3B paralog, UPF3A, is stabilized in all UPF3B patients, and partially compensates for the loss of UPF3B function. Interestingly, UPF3A protein, but not mRNA, was stabilised in a quantitative manner that inversely correlated with the severity of patients' phenotype. This suggested that the ability to stabilize the UPF3A protein is a crucial modifier of the neurological symptoms due to loss of UPF3B. We also identified ARHGAP24, which encodes a GTPase-activating protein, as a canonical target of NMD, and we provide evidence that deregulation of this gene inhibits axon and dendrite outgrowth and branching. Our results demonstrate that the UPF3B-dependent NMD pathway is a major regulator of the transcriptome and that its targets have important roles in neuronal cells.
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Affiliation(s)
- LS Nguyen
- Department of Paediatrics, University of Adelaide, Adelaide, SA, Australia
- Department of Genetic Medicine, SA Pathology, Adelaide, SA, Australia
| | - L Jolly
- Department of Genetic Medicine, SA Pathology, Adelaide, SA, Australia
| | - C Shoubridge
- Department of Paediatrics, University of Adelaide, Adelaide, SA, Australia
- Department of Genetic Medicine, SA Pathology, Adelaide, SA, Australia
| | - WK Chan
- Department of Bioinformatics and Computational Biology, University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - L Huang
- Department of Reproductive Medicine, University of California, San Diego, CA, USA
| | - F Laumonnier
- INSERM, U930, Tours, France
- CNRS, ERL3106, Tours, France
- University Francois-Rabelais, UMR ‘Imaging and Brain’, Tours, France
| | - M Raynaud
- INSERM, U930, Tours, France
- University Francois-Rabelais, UMR ‘Imaging and Brain’, Tours, France
- CHRU de Tours, Service de Genetique, Tours, France
| | - A Hackett
- GOLD Service, Hunter Genetics, Newcastle, Australia
| | - M Field
- GOLD Service, Hunter Genetics, Newcastle, Australia
| | - J Rodriguez
- J.C. Self Research Institute, Greenwood Genetic Centre, Greenwood, SC, USA
| | - AK Srivastava
- J.C. Self Research Institute, Greenwood Genetic Centre, Greenwood, SC, USA
| | - Y Lee
- Child Psychiatry Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - R Long
- Child Psychiatry Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - AM Addington
- Child Psychiatry Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - JL Rapoport
- Child Psychiatry Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - S Suren
- Human Developmental Biology Resource, Neural Development Unit, UCL Institute of Child Health, London, UK
| | - CN Hahn
- Department of Molecular Pathology, Centre for Cancer Biology, SA Pathology, Adelaide, SA, Australia
| | - J Gamble
- Centenary Institute of Cancer Medicine & Cell Biology, University of Sydney, NSW, Australia
| | - MF Wilkinson
- Department of Reproductive Medicine, University of California, San Diego, CA, USA
| | - MA Corbett
- Department of Genetic Medicine, SA Pathology, Adelaide, SA, Australia
| | - J Gecz
- Department of Paediatrics, University of Adelaide, Adelaide, SA, Australia
- Department of Genetic Medicine, SA Pathology, Adelaide, SA, Australia
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Redelmeier DA, Chan WK, Mullainathan S, Shafir E. Social benefit payments and acute injury among low-income mothers. Open Med 2012; 6:e101-8. [PMID: 23687523 PMCID: PMC3654504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/30/2012] [Accepted: 04/09/2012] [Indexed: 11/20/2022]
Abstract
BACKGROUND Human error due to risky behaviour is a common and important contributor to acute injury related to poverty. We studied whether social benefit payments mitigate or exacerbate risky behaviours that lead to emergency visits for acute injury among low-income mothers with dependent children. METHODS We analyzed total emergency department visits throughout Ontario to identify women between 15 and 55 years of age who were mothers of children younger than 18 years, who were living in the lowest socio-economic quintile and who presented with acute injury. We used universal health care databases to evaluate emergency department visits during specific days on which social benefit payments were made (child benefit distribution) relative to visits on control days over a 7-year interval (1 April 2003 to 31 March 2010). RESULTS A total of 153 377 emergency department visits met the inclusion criteria. We observed fewer emergencies per day on child benefit payment days than on control days (56.4 v. 60.1, p = 0.008). The difference was primarily explained by lower values among mothers age 35 years or younger (relative reduction 7.29%, 95% confidence interval [CI] 1.69% to 12.88%), those living in urban areas (relative reduction 7.07%, 95% CI 3.05% to 11.10%) and those treated at community hospitals (relative reduction 6.83%, 95% CI 2.46% to 11.19%). No significant differences were observed for the 7 days immediately before or the 7 days immediately after the child benefit payment. INTERPRETATION Contrary to political commentary, we found that small reductions in relative poverty mitigated, rather than exacerbated, risky behaviours that contribute to acute injury among low-income mothers with dependent children.
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Chan WK, Redelmeier DA. Simpson's paradox and the association between vitamin D deficiency and increased heart disease. Am J Cardiol 2012; 110:143-4. [PMID: 22464214 DOI: 10.1016/j.amjcard.2012.02.062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 02/21/2012] [Accepted: 02/21/2012] [Indexed: 02/08/2023]
Abstract
Several recent investigations have highlighted a potential link between vitamin D deficiency and increased heart disease. Observational studies suggest cardioprotective benefits related to supplementation, but randomized trials remain to be conducted. This report adds a caution based on a statistical paradox that is rarely mentioned in formal medical training or in common medical journals. Insight into this phenomenon, termed Simpson's paradox, may prevent clinicians from drawing faulty conclusions about vitamin D deficiency and heart disease.
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Nguyen PM, Wang D, Wang Y, Li Y, Uchizono JA, Chan WK. p23 co-chaperone protects the aryl hydrocarbon receptor from degradation in mouse and human cell lines. Biochem Pharmacol 2012; 84:838-50. [PMID: 22759865 DOI: 10.1016/j.bcp.2012.06.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 06/15/2012] [Accepted: 06/18/2012] [Indexed: 11/18/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-sensitive transcription factor which is responsible for most 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicities. Without ligand, the AhR complex is cytoplasmic and contains p23. Our objective was to investigate whether the wild type p23 levels are important for the AhR function. We generated eight p23-specific knockdown stable cell lines via either electroporation or lentiviral infection. Five of these stable cell lines were generated from a mouse hepatoma cell line (Hepa1c1c7) and three were from human hepatoma and cervical cell lines (Hep3B and HeLa). All of them expressed lower AhR protein levels, leading to reduced ligand-induced, DRE-driven downstream activity. The AhR protein levels in p23-specific knockdown stable cells were reversed back to wild type levels after exogenous p23 was introduced. Reduction of the AhR protein levels in these stable cells was caused by a decrease in the AhR message levels and an increase of the AhR protein degradation in the absence of ligand. This ligand-independent degradation of AhR was not reversed by MG132, suggesting that the 26S proteasome was not responsible for the degradation. In addition, MG132 could not protect AhR from the ligand-induced degradation in both mouse and human p23-knockdown stable cells.
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Affiliation(s)
- Phuong Minh Nguyen
- Department of Labour Physiology, Vietnam Military Medical University, Hadong, Hanoi, Viet Nam
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Wang Y, Yang D, Chang A, Chan WK, Zhao B, Denison MS, Xue L. Synthesis of a ligand–quencher conjugate for the ligand binding study of the aryl hydrocarbon receptor using a FRET assay. Med Chem Res 2012. [DOI: 10.1007/s00044-011-9575-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wang Y, Li Y, Wang D, Li Y, Chang A, Chan WK. Suppression of the hypoxia inducible factor-1 function by redistributing the aryl hydrocarbon receptor nuclear translocator from nucleus to cytoplasm. Cancer Lett 2012; 320:111-21. [PMID: 22306343 DOI: 10.1016/j.canlet.2012.01.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 01/12/2012] [Accepted: 01/26/2012] [Indexed: 11/19/2022]
Abstract
The aryl hydrocarbon receptor nuclear translocator (ARNT) heterodimerizes with hypoxia inducible factor-1α (HIF-1α), followed by upregulation of genes that are essential for carcinogenesis. We utilized a novel peptide (Ainp1) to address whether the HIF-1α signaling could be suppressed by an ARNT-mediated mechanism. Ainp1 suppresses the HIF-1α-dependent luciferase expression in Hep3B cells and this suppression can be reversed by ARNT. Ainp1 reduces the interaction between ARNT and HIF-1α, suppresses the formation of the HIF-1 gel shift complex, and suppresses the ARNT recruitment to the vegf promoter. These effects are partly mediated by redistribution of the nuclear ARNT contents to the cytoplasm.
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Affiliation(s)
- Yu Wang
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA
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Lieu CF, Chan WK, Ooi KT. Experimental investigation of the reciprocating ball pump (RBP). Med Eng Phys 2011; 34:1101-8. [PMID: 22205041 DOI: 10.1016/j.medengphy.2011.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 11/05/2011] [Accepted: 11/17/2011] [Indexed: 10/14/2022]
Abstract
This paper presents experimental investigations of a novel miniature reciprocating ball pump (RBP) as a potential infusion pump or drug delivery system. The objectives of this study are to validate the RBP's operational principle and to evaluate its performance. In the tests, the basic functionality of the pump has been established at different pumping frequencies ranging from 1.667 Hz (100 rpm) to 4.167 Hz (250 rpm) against different pressure heads ranging from 0 mmH(2)O and 100 mmH(2)O. In addition, experimental results show that the RBP can deliver a higher flow rate with a volumetric efficiency of 120% as compared to a conventional single acting reciprocating pump running under the same operating conditions.
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Affiliation(s)
- C F Lieu
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
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Nguyen PM, Wang D, Li Y, Chan WK. p23 co‐chaperone is essential for the optimal function of the aryl hydrocarbon receptor in Hepa1c1c7 cells by modulating the AhR content. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1007.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Phuong Minh Nguyen
- Department of Labour PhysiologyVietnam Military Medical UniversityHanoiVietnam
| | - Depeng Wang
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - Yanjie Li
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - William K Chan
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
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Wang Y, Li Y, Peng D, Chan WK. The aryl hydrocarbon receptor nuclear translocator‐interacting peptide 1 suppresses hypoxia inducible factor‐1 alpha signaling via an Arnt‐dependent mechanism. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1007.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yu Wang
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - Yanjie Li
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - Depeng Peng
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
| | - William K Chan
- Department of Pharmaceutics and Medicinal ChemistryUniversity of the PacificStocktonCA
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