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Chan WK, Sun JH, Liou MJ, Hsu CJ, Lu YL, Chou WY, Li YR, Liu FH. Novel and Advanced Ultrasound Techniques for Thyroid Thermal Ablation. Endocrinol Metab (Seoul) 2024; 39:40-46. [PMID: 38347707 PMCID: PMC10901668 DOI: 10.3803/enm.2024.1917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 01/15/2024] [Indexed: 03/01/2024] Open
Abstract
Thyroid radiofrequency ablation and microwave ablation are widely adopted minimally invasive treatments for diverse thyroid conditions worldwide. Fundamental skills such as the trans-isthmic approach and the moving shot technique are crucial for performing thyroid ablation, and advanced techniques, including hydrodissection and vascular ablation, improve safety and efficacy and reduce complications. Given the learning curve associated with ultrasound-guided therapeutic procedures, operators need training and experience. While training models exist, limited attention has been given to ultrasound maneuvers in ablation needle manipulation. This article introduces two essential maneuvers, the zigzag moving technique and the alienate maneuver, while also reviewing the latest ultrasound techniques in thyroid ablation, contributing valuable insights into this evolving field.
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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] [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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Van Trimpont M, Schalk AM, De Visser Y, Nguyen HA, Reunes L, Vandemeulebroecke K, Peeters E, Su Y, Lee H, Lorenzi PL, Chan WK, Mondelaers V, De Moerloose B, Lammens T, Goossens S, Van Vlierberghe P, Lavie A. In vivo stabilization of a less toxic asparaginase variant leads to a durable antitumor response in acute leukemia. Haematologica 2022; 108:409-419. [PMID: 35979719 PMCID: PMC9890011 DOI: 10.3324/haematol.2022.281390] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2002] [Indexed: 02/03/2023] Open
Abstract
Asparagine is a non-essential amino acid since it can either be taken up via the diet or synthesized by asparagine synthetase. Acute lymphoblastic leukemia (ALL) cells do not express asparagine synthetase or express it only minimally, which makes them completely dependent on extracellular asparagine for their growth and survival. This dependency makes ALL cells vulnerable to treatment with L-asparaginase, an enzyme that hydrolyzes asparagine. To date, all clinically approved L-asparaginases have significant L-glutaminase co-activity, associated with non-immune related toxic side effects observed during therapy. Therefore, reduction of L-glutaminase co-activity with concomitant maintenance of its anticancer L-asparaginase effect may effectively improve the tolerability of this unique drug. Previously, we designed a new alternative variant of Erwinia chrysanthemi (ErA; Erwinaze) with decreased L-glutaminase co-activity, while maintaining its L-asparaginase activity, by the introduction of three key mutations around the active site (ErA-TM). However, Erwinaze and our ErA-TM variant have very short half-lives in vivo. Here, we show that the fusion of ErA-TM with an albumin binding domain (ABD)-tag significantly increases its in vivo persistence. In addition, we evaluated the in vivo therapeutic efficacy of ABD-ErA-TM in a B-ALL xenograft model of SUP-B15. Our results show a comparable long-lasting durable antileukemic effect between the standard-of-care pegylated-asparaginase and ABD-ErA-TM L-asparaginase, but with fewer co-glutaminase-related acute side effects. Since the toxic side effects of current L-asparaginases often result in treatment discontinuation in ALL patients, this novel ErA-TM variant with ultra-low L-glutaminase co-activity and long in vivo persistence may have great clinical potential.
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Grima-Reyes M, Vandenberghe A, Nemazanyy I, Meola P, Paul R, Reverso-Meinietti J, Martinez-Turtos A, Nottet N, Chan WK, Lorenzi PL, Marchetti S, Ricci JE, Chiche J. Tumoral microenvironment prevents de novo asparagine biosynthesis in B cell lymphoma, regardless of ASNS expression. SCIENCE ADVANCES 2022; 8:eabn6491. [PMID: 35857457 PMCID: PMC9258813 DOI: 10.1126/sciadv.abn6491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Depletion of circulating asparagine with l-asparaginase (ASNase) is a mainstay of leukemia treatment and is under investigation in many cancers. Expression levels of asparagine synthetase (ASNS), which catalyzes asparagine synthesis, were considered predictive of cancer cell sensitivity to ASNase treatment, a notion recently challenged. Using [U-13C5]-l-glutamine in vitro and in vivo in a mouse model of B cell lymphomas (BCLs), we demonstrated that supraphysiological or physiological concentrations of asparagine prevent de novo asparagine biosynthesis, regardless of ASNS expression levels. Overexpressing ASNS in ASNase-sensitive BCL was insufficient to confer resistance to ASNase treatment in vivo. Moreover, we showed that ASNase's glutaminase activity enables its maximal anticancer effect. Together, our results indicate that baseline ASNS expression (low or high) cannot dictate BCL dependence on de novo asparagine biosynthesis and predict BCL sensitivity to dual ASNase activity. Thus, except for ASNS-deficient cancer cells, ASNase's glutaminase activity should be considered in the clinic.
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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] [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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Li YR, Chou WY, Chan WK, Cheng KL, Sun JH, Liu FH, Chen ST, Liou MJ. Successful Applications of Food-Assisted and -Simulated Training Model of Thyroid Radiofrequency Ablation. Front Endocrinol (Lausanne) 2022; 13:809835. [PMID: 35432189 PMCID: PMC9009177 DOI: 10.3389/fendo.2022.809835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/07/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Radiofrequency ablation (RFA) for benign thyroid nodules is one kind of scarless treatment for symptomatic or cosmetic benign thyroid nodules. However, how to train RFA-naive physicians to become qualified operators for thyroid RFA is an important issue. Our study aimed to introduce a successful training model of thyroid RFA. MATERIALS AND METHODS We used a food-assisted and -simulated training model of thyroid RFA. Chicken hearts were simulated into thyroid nodules, three-layer pork meats were simulated into peri-thyroid structure, and gel bottles were simulated into trachea, respectively. Successful training ablations were defined as chicken hearts that were fully cooked. After repeating training ablations of chicken hearts at least 100 times with the nearly 100% success rates for three young trainees, they served as the first assistant for the real procedures of thyroid RFA and then were qualified to perform thyroid RFA on real patients under the supervision of one experienced interventional radiologist. RESULTS 23 real patients who received RFA and follow-up at least 6 months after treatment were included in Linkou Chang Gung Memorial Hospital from January 1, 2020 to October 1, 2021. Three young endocrinologists performed thyroid RFA independently. The outcomes were volume reduction rate (VRR), major complications and minor complications. The median VRR at 12 months was 82.00%, two major complications were transient hoarseness, and three minor complications were wound pain. All complications were completely recovered within three days. CONCLUSIONS For young and RFA-native physicians without any basic skills of echo-guided intervention, this food-assisted and -simulated training model of thyroid RFA was useful for medical training and education.
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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. THE MEDICAL JOURNAL OF MALAYSIA 2021; 76:199-204. [PMID: 33742628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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Yuan Y, Lo KC, Szeto L, Chan WK. Synthesis of Pyrazinopyrazine-Fused Azaacenes through Direct Condensation Reactions between Quinoxalinediamine and Diketones. J Org Chem 2020; 85:6372-6379. [PMID: 32312048 DOI: 10.1021/acs.joc.9b03504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the synthesis of a new type of pyrazinopyrazine-fused azaacene molecules by a simple and versatile procedure. 6,9-Dihexyldithieno[3,2-f:2',3'-h]quinoxaline-2,3-diamine was synthesized through the condensation between 2,7-dihexylbenzo[1,2-b:6,5-b']dithiophene-4,5-diamine and bis(2,2,2-trifluoroethyl) oximidate. A series of derivatized molecules with extended two-dimensional aromatic fused-ring structures could be obtained by simple condensation reactions between the quinoxalinediamine intermediate and various diketones. The reaction was proved to be effective for the construction of tetrazaacene derivatives with extended heterocyclic aromatic ring systems. The molecules obtained exhibit low-lying LUMO levels that can be fine-tuned by modifying the molecular structure. Crystallographic results showed that in a solid state, the molecules form "brick wall" structures with a close π-π stacking mode. The stacking between the π-ring systems in the molecules could be further enhanced by expanding the large 2D planar-conjugated structure.
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Lubkowski J, Vanegas J, Chan WK, Lorenzi PL, Weinstein JN, Sukharev S, Fushman D, Rempe S, Anishkin A, Wlodawer A. Mechanism of Catalysis by l-Asparaginase. Biochemistry 2020; 59:1927-1945. [PMID: 32364696 DOI: 10.1021/acs.biochem.0c00116] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two bacterial type II l-asparaginases, from Escherichia coli and Dickeya chrysanthemi, have played a critical role for more than 40 years as therapeutic agents against juvenile leukemias and lymphomas. Despite a long history of successful pharmacological applications and the apparent simplicity of the catalytic reaction, controversies still exist regarding major steps of the mechanism. In this report, we provide a detailed description of the reaction catalyzed by E. coli type II l-asparaginase (EcAII). Our model was developed on the basis of new structural and biochemical experiments combined with previously published data. The proposed mechanism is supported by quantum chemistry calculations based on density functional theory. We provide strong evidence that EcAII catalyzes the reaction according to the double-displacement (ping-pong) mechanism, with formation of a covalent intermediate. Several steps of catalysis by EcAII are unique when compared to reactions catalyzed by other known hydrolytic enzymes. Here, the reaction is initiated by a weak nucleophile, threonine, without direct assistance of a general base, although a distant general base is identified. Furthermore, tetrahedral intermediates formed during the catalytic process are stabilized by a never previously described motif. Although the scheme of the catalytic mechanism was developed only on the basis of data obtained from EcAII and its variants, this novel mechanism of enzymatic hydrolysis could potentially apply to most (and possibly all) l-asparaginases.
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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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. MALAYSIAN FAMILY PHYSICIAN : THE OFFICIAL JOURNAL OF THE ACADEMY OF FAMILY PHYSICIANS OF MALAYSIA 2020; 15:15-22. [PMID: 32284800 PMCID: PMC7136671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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Chan WK, Horvath TD, Tan L, Link T, Harutyunyan KG, Pontikos MA, Anishkin A, Du D, Martin LA, Yin E, Rempe SB, Sukharev S, Konopleva M, Weinstein JN, Lorenzi PL. Glutaminase Activity of L-Asparaginase Contributes to Durable Preclinical Activity against Acute Lymphoblastic Leukemia. Mol Cancer Ther 2019; 18:1587-1592. [PMID: 31209181 DOI: 10.1158/1535-7163.mct-18-1329] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 03/25/2019] [Accepted: 06/11/2019] [Indexed: 11/16/2022]
Abstract
We and others have reported that the anticancer activity of L-asparaginase (ASNase) against asparagine synthetase (ASNS)-positive cell types requires ASNase glutaminase activity, whereas anticancer activity against ASNS-negative cell types does not. Here, we attempted to disentangle the relationship between asparagine metabolism, glutamine metabolism, and downstream pathways that modulate cell viability by testing the hypothesis that ASNase anticancer activity is based on asparagine depletion rather than glutamine depletion per se. We tested ASNase wild-type (ASNaseWT) and its glutaminase-deficient Q59L mutant (ASNaseQ59L) and found that ASNase glutaminase activity contributed to durable anticancer activity against xenografts of the ASNS-negative Sup-B15 leukemia cell line in NOD/SCID gamma mice, whereas asparaginase activity alone yielded a mere growth delay. Our findings suggest that ASNase glutaminase activity is necessary for durable, single-agent anticancer activity in vivo, even against ASNS-negative cancer types.
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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] [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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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. THE MEDICAL JOURNAL OF MALAYSIA 2018; 73:137-140. [PMID: 29962496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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Kam CS, Leung TL, Liu F, Djurišić AB, Xie MH, Chan WK, Zhou Y, Shih K. Lead removal from water – dependence on the form of carbon and surface functionalization. RSC Adv 2018; 8:18355-18362. [PMID: 35541110 PMCID: PMC9080567 DOI: 10.1039/c8ra02264j] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/13/2018] [Indexed: 12/11/2022] Open
Abstract
Functionalization with same functional group results in varied lead adsorption performance for different nanostructured carbon materials.
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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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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. THE MEDICAL JOURNAL OF MALAYSIA 2017; 72:209-214. [PMID: 28889131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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Chan WK, Wong YW, Chua CK, Lee CW, Feng C. Rapid manufacturing techniques in the development of an axial blood pump impeller. Proc Inst Mech Eng H 2016; 217:469-75. [PMID: 14702984 DOI: 10.1243/09544110360729108] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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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Shum EY, Jones SH, Shao A, Chousal JN, Krause MD, Chan WK, Lou CH, Espinoza JL, Song HW, Phan MH, Ramaiah M, Huang L, McCarrey JR, Peterson KJ, De Rooij DG, Cook-Andersen H, Wilkinson MF. The Antagonistic Gene Paralogs Upf3a and Upf3b Govern Nonsense-Mediated RNA Decay. Cell 2016; 165:382-95. [PMID: 27040500 PMCID: PMC4826573 DOI: 10.1016/j.cell.2016.02.046] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/02/2016] [Accepted: 02/20/2016] [Indexed: 01/11/2023]
Abstract
Gene duplication is a major evolutionary force driving adaptation and speciation, as it allows for the acquisition of new functions and can augment or diversify existing functions. Here, we report a gene duplication event that yielded another outcome--the generation of antagonistic functions. One product of this duplication event--UPF3B--is critical for the nonsense-mediated RNA decay (NMD) pathway, while its autosomal counterpart--UPF3A--encodes an enigmatic protein previously shown to have trace NMD activity. Using loss-of-function approaches in vitro and in vivo, we discovered that UPF3A acts primarily as a potent NMD inhibitor that stabilizes hundreds of transcripts. Evidence suggests that UPF3A acquired repressor activity through simple impairment of a critical domain, a rapid mechanism that may have been widely used in evolution. Mice conditionally lacking UPF3A exhibit "hyper" NMD and display defects in embryogenesis and gametogenesis. Our results support a model in which UPF3A serves as a molecular rheostat that directs developmental events.
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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. THE MEDICAL JOURNAL OF MALAYSIA 2016; 71:88-90. [PMID: 27326953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chan WK, Suwannasaen D, Throm RE, Li Y, Eldridge PW, Houston J, Gray JT, Pui CH, Leung W. Chimeric antigen receptor-redirected CD45RA-negative T cells have potent antileukemia and pathogen memory response without graft-versus-host activity. Leukemia 2015; 29:387-95. [PMID: 24888271 PMCID: PMC4275423 DOI: 10.1038/leu.2014.174] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 05/23/2014] [Indexed: 12/27/2022]
Abstract
Chimeric antigen receptor (CAR)-redirected cellular therapy is an attractive modality for cancer treatment. We hypothesized that allogeneic CAR-engineered CD45RA-negative T cells can control cancer and infection without the risk of graft-versus-host disease (GVHD). We used CD19(+) MLL-rearranged leukemia as prototype because it is an aggressive and generally drug-resistant malignancy. CD45RA(-) cells that were transduced with anti-CD19 CAR containing 4-1BB and CD3ζ signaling domains effectively lysed MLL-rearranged leukemia cell lines and primary blasts in vitro. In a disseminated leukemia mouse model, CAR(+)CD45RA(-) cells significantly reduced leukemia burdens and prolonged overall survival without GVHD. CAR(+) cells were sustainable in blood, and all the treated mice remained leukemia-free even after they were re-challenged with leukemia cells. Despite the transduction process, CD45RA(-) cells retained recall activity both in vitro and in vivo against human pathogens commonly found in cancer patients. In comparison with CD45RA(+) cells, CD45RA(-) cells showed less allogeneic activity in mixed leukocyte reactions and in mouse models. Thus, the use of CAR(+)CD45RA(-) cells can separate GVHD from graft-versus-malignancy effect and infection control. These cells should also be useful in nontransplant settings and may be administered as off-the-shelf third-party cells.
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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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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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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] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
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