Displaying publications 41 - 60 of 72 in total

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  1. Khaw YC, Wong JK, Sahran Y, Nor-Azman MZ, Faisham WI
    Malays Orthop J, 2020 Nov;14(3):198-201.
    PMID: 33403087 DOI: 10.5704/MOJ.2011.034
    Telangiectatic osteosarcoma is a rare variant of osteosarcoma and can be easily misdiagnosed as aneurysmal bone cyst. We report an atypical case of iliac telangiectatic osteosarcoma in a young healthy female, who presents with painful slow growing expansile lytic septate lesion in the left hemipelvis, which is initially treated as aneurysmal bone cyst. The diagnosis of aneurysmal bone cyst is made after histopathological examination of core needle biopsy. Her condition became unstable and massive bleeding is noted at the lesion site after sclerosant injection. She undergoes emergency hemipelvectomy and eventually the biopsy turns up to be telangiectatic osteosarcoma. Our case highlights that core needle biopsy is not useful in making diagnosis for iliac telangiectatic carcinoma. Hence, an open biopsy should be carried out in our case. This case also emphasises on careful evaluation for malignancy which is mandatory because bleeding from pelvis after an unsuitable treatment can be grave, to the extent that major amputation hemipelvectomy is an option. Even though telangiectatic osteosarcoma has the same prognosis and treatment with conventional osteosarcoma, the outcome of delayed treatment for telangiectatic osteosarcoma is not good due to the dilemma in establishing an early correct diagnosis.
  2. Chan CMH, Wong JE, Wee LH, Jamil NA, Yeap LLL, Swarna Nantha Y, et al.
    Occup Med (Lond), 2020 Sep 09;70(6):400-406.
    PMID: 32537649 DOI: 10.1093/occmed/kqaa107
    BACKGROUND: Past research on work engagement has focused almost exclusively on either psychological or work-related factors in almost wholly separate literature. There is therefore a need to examine how these factors collectively influence work engagement.

    AIMS: To determine levels of work engagement and to identify psychological and work-related characteristics predicting work engagement in employees in Malaysia.

    METHODS: We recruited 5235 employees from 47 public and private organizations in Malaysia who responded to an online health survey. We assessed work engagement with the 9-item Utrecht Work Engagement Scale (UWES-9) and psychological distress using the 6-item Kessler scale. We performed multiple linear regression to determine predictors of work engagement.

    RESULTS: Employee mean age was 33.8 years (standard deviation [SD] ± 8.8). The mean work engagement score on the UWES-9 was 3.53 (SD ± 0.94). Eleven of 18 variables on multiple regression predicted work engagement, F(18, 4925) = 69.02, P < 0.001, R2 = 0.201. Factors that predicted higher work engagement were age, marital status, education level, job type, job permanency, longer sleep duration, lower psychological distress and no history of workplace bullying.

    CONCLUSIONS: Key factors associated with poorer work engagement in Malaysian employees include inadequate sleep, psychological distress and a history of workplace bullying. These are modifiable factors that individuals and employers can target to improve work engagement, ideally tailored according to occupational type.

  3. Wroe AJ, McAuley G, Teran AV, Wong J, Petasecca M, Lerch M, et al.
    J Appl Clin Med Phys, 2017 Sep;18(5):315-324.
    PMID: 28719019 DOI: 10.1002/acm2.12120
    As technology continues to develop, external beam radiation therapy is being employed, with increased conformity, to treat smaller targets. As this occurs, the dosimetry methods and tools employed to quantify these fields for treatment also have to evolve to provide increased spatial resolution. The team at the University of Wollongong has developed a pixelated silicon detector prototype known as the dose magnifying glass (DMG) for real-time small-field metrology. This device has been tested in photon fields and IMRT. The purpose of this work was to conduct the initial performance tests with proton radiation, using beam energies and modulations typically associated with proton radiosurgery. Depth dose and lateral beam profiles were measured and compared with those collected using a PTW parallel-plate ionization chamber, a PTW proton-specific dosimetry diode, EBT3 Gafchromic film, and Monte Carlo simulations. Measurements of the depth dose profile yielded good agreement when compared with Monte Carlo, diode and ionization chamber. Bragg peak location was measured accurately by the DMG by scanning along the depth dose profile, and the relative response of the DMG at the center of modulation was within 2.5% of that for the PTW dosimetry diode for all energy and modulation combinations tested. Real-time beam profile measurements of a 5 mm 127 MeV proton beam also yielded FWHM and FW90 within ±1 channel (0.1 mm) of the Monte Carlo and EBT3 film data across all depths tested. The DMG tested here proved to be a useful device at measuring depth dose profiles in proton therapy with a stable response across the entire proton spread-out Bragg peak. In addition, the linear array of small sensitive volumes allowed for accurate point and high spatial resolution one-dimensional profile measurements of small radiation fields in real time to be completed with minimal impact from partial volume averaging.
  4. Cummins E, Waseem R, Piyasena D, Wang CY, Suen C, Ryan C, et al.
    Sleep Breath, 2021 Jun 29.
    PMID: 34185230 DOI: 10.1007/s11325-021-02383-3
    PURPOSE: Since hypoxia increases erythropoietin production and inflammation, the complete blood count (CBC) has been proposed as an inexpensive alternative for obstructive sleep apnea (OSA) screening. The objective of this study was to determine whether or not intermittent hypoxia and OSA severity, as measured by the mean oxygen saturation (SpO2) and apnea-hypopnea index (AHI), affect parameters measured by the CBC.

    METHODS: This retrospective study included a total of 941 surgical patients who had a pre-operative home sleep study. The pre-operative CBC was extracted from the electronic patient records. Patients were stratified according to their AHI scores, into mild (AHI ≥ 5 - 

  5. Wong JL, Siti Azrin AH, Narizan MI, Norliah Y, Noraida M, Amanina A, et al.
    Trop Biomed, 2014 Sep;31(3):534-9.
    PMID: 25382481 MyJurnal
    Hands of Health Care Personnel (HCP) are one of the most common vehicles for the transmission of infection. Microorganisms can survive well on the hands of HCP for a certain duration. Therefore, the purpose of this study is to bring awareness to HCP that their hands can actually be contaminated with many microorganisms. These microbes on the hands of HCP can potentially infect their patients if they do not comply with the proper hand hygiene practice. This cross-sectional study was conducted at a randomly selected Intensive Care Unit (ICU) and general ward in a hospital. Twenty five HCP from each ward were randomly selected and their hands were imprinted on blood culture plates. Microorganism growth were quantified and identified. Data were analyzed and presented as descriptive analysis. One hundred blood agar plates were processed and analyzed. Majority (71%) of the samples had more than 50 colony-forming units (CFU) and only 17% of the samples had less than 25 CFU. Microorganisms identified include Staphylococcus spp., Acinetobacter spp., Enterobacteriaceae, Pseudomonas spp., Moraxella, Delftiaacidovorans and fungi. All isolated microorganisms were antibiotic sensitive strain. This study showed that the hands of HCP were contaminated with many microorganisms. Therefore, it is imperative that HCP must practice proper hand hygiene when taking care of their patients in the wards.
  6. Salim H, Lee PY, Sharif-Ghazali S, Cheong AT, Wong J, Young I, et al.
    J Med Internet Res, 2021 09 09;23(9):e26434.
    PMID: 34499039 DOI: 10.2196/26434
    BACKGROUND: Technology, including mobile apps, has the potential to support self-management of long-term conditions and can be tailored to enhance adoption. We developed an app to support asthma self-management among people with limited health literacy in a web-based workshop (to ensure physical distancing during the COVID-19 pandemic).

    OBJECTIVE: The aim of this study is to develop and test a prototype asthma self-management mobile app tailored to the needs of people with limited health literacy through a web-based workshop.

    METHODS: We recruited participants from a primary care center in Malaysia. We adapted a design sprint methodology to a web-based workshop in five stages over 1 week. Patients with asthma and limited health literacy provided insights into real-life self-management issues in stage 1, which informed mobile app development in stages 2-4. We recruited additional patients to test the prototype in stage 5 using a qualitative research design. Participants gave feedback through a concurrent thinking-aloud process moderated by a researcher. Each interview lasted approximately 1 hour. Screen recordings of app browsing activities were performed. Interviews were audio-recorded and analyzed using a thematic approach to identify utility and usability issues.

    RESULTS: The stakeholder discussion identified four themes: individual, family, friends, and society and system levels. Five patients tested the prototype. Participants described 4 ways in which the app influenced or supported self-management (utility): offering information, providing access to an asthma action plan, motivating control of asthma through support for medication adherence, and supporting behavior change through a reward system. Specific usability issues addressed navigation, comprehension, and layout.

    CONCLUSIONS: This study proved that it was possible to adapt the design sprint workshop to a web-based format with the added advantage that it allowed the development and the testing process to be done efficiently through various programs. The resultant app incorporated advice from stakeholders, including sources for information about asthma, medication and appointment reminders, accessible asthma action plans, and sources for social support. The app is now ready to move to feasibility testing.

  7. Tang ASO, Yong KY, Wong J, Chua HH, Chew LP
    Med J Malaysia, 2017 04;72(2):122-123.
    PMID: 28473676
    This is a case report of subcutaneous mycosis presenting as a non-healing left calf ulcer in an immunocompromised patient. Traumatic inoculation of the causative agent is the most likely route of infection. The diagnosis requires a detailed history and high clinical suspicion, confirmed by histopathological examination. The management requires a multidisciplinary team approach involving surgeon, pathologist, physician sub-specialised in infectious disease, wound care nursing team as well as social support services. The literature review recommended that the treatment of choice for such infection is surgical debridement in addition to optimal antifungal therapy.
  8. Rejab M, Wong JHD, Jamalludin Z, Jong WL, Malik RA, Wan Ishak WZ, et al.
    Australas Phys Eng Sci Med, 2018 Jun;41(2):475-485.
    PMID: 29756166 DOI: 10.1007/s13246-018-0647-6
    This study investigates the characteristics and application of the optically-stimulated luminescence dosimeter (OSLD) in cobalt-60 high dose rate (HDR) brachytherapy, and compares the results with the dosage produced by the treatment planning system (TPS). The OSLD characteristics comprised linearity, reproducibility, angular dependence, depth dependence, signal depletion, bleaching rate and cumulative dose measurement. A phantom verification exercise was also conducted using the Farmer ionisation chamber and in vivo diodes. The OSLD signal indicated a supralinear response (R2 = 0.9998). It exhibited a depth-independent trend after a steep dose gradient region. The signal depletion per readout was negligible (0.02%), with expected deviation for angular dependence due to off-axis sensitive volume, ranging from 1 to 16%. The residual signal of the OSLDs after 1 day bleached was within 1.5%. The accumulated and bleached OSLD signals had a standard deviation of ± 0.78 and ± 0.18 Gy, respectively. The TPS was found to underestimate the measured doses with deviations of 5% in OSLD, 17% in the Farmer ionisation chamber, and 7 and 8% for bladder and rectal diode probes. Discrepancies can be due to the positional uncertainty in the high-dose gradient. This demonstrates a slight displacement of the organ at risk near the steep dose gradient region will result in a large dose uncertainty. This justifies the importance of in vivo measurements in cobalt-60 HDR brachytherapy.
  9. Chaw S, Lo Y, Shariffuddin II, Wong J, Lee J, Leong DW, et al.
    Paediatr Anaesth, 2019 01;29(1):68-76.
    PMID: 30381868 DOI: 10.1111/pan.13528
    BACKGROUND: Effective pain management involves a cycle of continual pain assessment, good pain control strategies, and assessment of a standard quality improvement measures. A validated questionnaire that focuses on the quality of postoperative pain management in pediatric surgical patients and parental satisfaction on pain treatment is lacking. We, therefore, modified the revised American Pain Society Patient Outcome Questionnaire to evaluate the quality of postoperative pain management in a pediatric surgical setting. The primary aim of this study was to validate the modified version of revised American Pain Society Patient Outcome Questionnaire.

    METHODS: Parents whose children aged below 12 years and were scheduled for elective surgery in a teaching hospital, were approached to participate in this survey. The reliability of the modified version of revised American Pain Society Patient Outcome Questionnaire was evaluated using Cronbach's alpha test, while the construct validity was assessed with a principal component analysis using a varimax rotation. The parental satisfaction with pain treatment received was measured.

    RESULTS: A total of 108 parents completed the questionnaire. The internal consistency of the questionnaire shows a Cronbach's alpha of 0.798. Principal component analysis revealed a four-factor structure of the 12 items which explained 69.7% of the total variance. The factors are "Interference of sleep and activity," "Pain severity and drowsiness," "Perception of care," and "Adverse effects," respectively. Our study showed that this questionnaire is a valid and reliable measure for "Interference of sleep and activity" and "Pain severity and drowsiness" factors, but not for "Perception of care" and "Adverse effects." The results for "Perception of care" and "Adverse effects," therefore, should be reported as individual items instead of total score. The parental satisfaction with pain treatment given was good (median 8.0; IQR 3.0).

    CONCLUSION: The modified version of revised American Pain Society Patient Outcome Questionnaire is a feasible and easy instrument to administer. The questionnaire can be used to obtain feedback from parents about the outcomes and experiences of pain management and is helpful in continuous quality evaluation and improvement in the postoperative care in a pediatric setting.

  10. Wong JHD, Bakhsh M, Cheah YY, Jong WL, Khor JS, Ng KH
    Radiat Prot Dosimetry, 2019 Dec 31;187(4):451-460.
    PMID: 31650160 DOI: 10.1093/rpd/ncz186
    This study characterises and evaluates an Al2O3:C-based optically stimulated luminescent dosemeter (OSLD) system, commercially known as the nanoDot™ dosemeter and the InLight® microStar reader, for personal and in vivo dose measurements in diagnostic radiology. The system characteristics, such as dose linearity, reader accuracy, reproducibility, batch homogeneity, energy dependence and signal stability, were explored. The suitability of the nanoDot™ dosemeters was evaluated by measuring the depth dose curve, in vivo dose measurement and image perturbation. The nanoDot™ dosemeters were observed to produce a linear dose with ±2.8% coefficient variation. Significant batch inhomogeneity (8.3%) was observed. A slight energy dependence (±6.1%) was observed between 60 and 140 kVp. The InLight® microStar reader demonstrated good accuracy and a reproducibility of ±2%. The depth dose curve measured using nanoDot™ dosemeters showed slightly lower responses than Monte Carlo simulation results. The total uncertainty for a single dose measurement using this system was 11%, but it could be reduced to 9.2% when energy dependence correction was applied.
  11. Wong JW, Yuen KH, Nagappan S, Shahul WS, Ho SS, Gan EK, et al.
    J Pharm Pharmacol, 2003 Feb;55(2):193-8.
    PMID: 12631411
    We have evaluated the therapeutic equivalence of a beta-cyclodextrin-artemisinin complex at an artemisinin dose of 150 mg, with a commercial reference preparation, Artemisinin 250 at a recommended dose of 250 mg. One hundred uncomplicated falciparum malarial patients were randomly assigned to orally receive either beta-cyclodextrin-artemisinin complex (containing 150 mg artemisinin) twice daily for five days or the active comparator (containing 250 mg artemisinin) twice daily for five days. The patients were hospitalized for seven days and were required to attend follow up assessments on days 14, 21, 28 and 35. All patients in both treatment groups were cured of the infection and achieved therapeutic success. At day seven of treatment, all patient blood was clear of the parasites and the sublingual temperature of all patients was less than 37.5 degrees C. Moreover, the parasite clearance time in both treatment groups was similar, being approximately three days after initiation of treatment. Comparable plasma artemisinin concentrations were observed between patients in both treatment groups at 1.5 and 3.0 h, although slightly higher levels were obtained with patients in the beta-cyclodextrin-artemisinin complex-treated group. The beta-cyclodextrin-artemisinin complex at a dose of 150 mg artemisinin was therapeutically equivalent to 250 mg Artemisinin 250. Additionally, patients receiving beta-cyclodextrin-artemisinin complex showed less variability in their plasma artemisinin concentrations at 1.5 h post-dosing, which suggested a more consistent rate of drug absorption.
  12. Chaw L, Koh WC, Jamaludin SA, Naing L, Alikhan MF, Wong J
    Emerg Infect Dis, 2020 Nov;26(11):2598-2606.
    PMID: 33035448 DOI: 10.3201/eid2611.202263
    We report the transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across different settings in Brunei. An initial cluster of SARS-CoV-2 cases arose from 19 persons who had attended the Tablighi Jama'at gathering in Malaysia, resulting in 52 locally transmitted cases. The highest nonprimary attack rates (14.8%) were observed from a subsequent religious gathering in Brunei and in households of attendees (10.6%). Household attack rates from symptomatic case-patients were higher (14.4%) than from asymptomatic (4.4%) or presymptomatic (6.1%) case-patients. Workplace and social settings had attack rates of <1%. Our analyses highlight that transmission of SARS-CoV-2 varies depending on environmental, behavioral, and host factors. We identify red flags for potential superspreading events, specifically densely populated gatherings with prolonged exposure in enclosed settings, persons with recent travel history to areas with active SARS-CoV-2 infections, and group behaviors. We propose differentiated testing strategies to account for differing transmission risk.
  13. Jong WL, Ung NM, Vannyat A, Rosenfeld AB, Wong JHD
    Phys Med, 2017 Oct;42:39-46.
    PMID: 29173919 DOI: 10.1016/j.ejmp.2017.08.011
    Challenges in treating lung tumours are related to the respiratory-induced tumour motion and the accuracy of dose calculation in charged particle disequilibrium condition. The dosimetric characteristics near the interface of lung and Perspex media in a moving phantom during respiratory-gated and non-gated radiotherapy were investigated using Gafchromic EBT2 and the MOSkin detector. The MOSkin detectors showed good agreement with the EBT2 films during static and gated radiotherapy. In static radiotherapy, the penumbral widths were found to be 3.66mm and 7.22mm in Perspex and lung media, respectively. In non-gated (moving) radiotherapy with 40mm respiratory amplitude, dose smearing effect was observed and the penumbral widths were increased to 28.81mm and 26.40mm, respectively. This has been reduced to 6.85mm and 9.81mm, respectively, in gated radiotherapy with 25% gating window. There were still some dose discrepancies as compared to static radiotherapy due to the residual motion. This should be taken into account in the margin generation for the target tumour.
  14. Htwe TT, Hamdi MM, Swethadri GK, Wong JO, Soe MM, Abdullah MS
    Singapore Med J, 2009 Jul;50(7):724-8.
    PMID: 19644631
    Thyroid cancer is the most common among all endocrine malignancies. The worldwide prevalence of goitre in the general population is estimated at 4-7 percent and the incidence of malignancy in goitrous thyroid is about ten percent. It is postulated that goitrous thyroid is a precursor lesion to the development of malignant thyroid diseases. As Sarawak is a state well known for endemic goitre, this study focused on establishing the incidence of thyroid malignancy among goitrous thyroid swellings.
  15. Than TH, Swethadri GK, Wong J, Ahmad T, Jamil D, Maganlal RK, et al.
    Singapore Med J, 2008 Apr;49(4):333-8.
    PMID: 18418527
    It has been suggested that Galectin-3 (Gal-3) and Galectin-7 (Gal-7) are potential tumour markers for differentiating thyroid carcinoma from its benign counter part. Galectins are beta-galactoside-binding proteins with Gal-3 being a redundant pre-mRNA splicing factor. They are supposed to be p53-related regulators in cell growth and apoptosis, being either anti-apoptotic or pro-apoptotic. Although the value of Gal-3 has been studied extensively, there is little knowledge regarding the expression of Gal-7 in thyroid malignancy.
  16. Wong JY, Chen YS, Chakravarthi S, Judson JP, L SR, Er HM
    Exp Ther Med, 2013 Nov;6(5):1247-1250.
    PMID: 24223653
    Euphorbia hirta is widely used in traditional remedies and has been used cross-culturally for generations against maladies such as asthma, skin ailments and hypertension. Previous studies have demonstrated that Euphorbia hirta has antibacterial activity, and have also indicated certain antimolluscidal, antimalarial and anti-inflammatory properties, the latter of which have been suggested to be more pronounced than those of the rheumatological drug, etanercept. To date, no studies have identified the anatomical effects of this herb on the organs of test animals. This study aimed to identify the effects of Euphorbia hirta on the ultrastructure of the murine liver, kidney and aorta. A total of 32 adult male Sprague-Dawley rats were divided into four groups; three groups were fed with aqueous extracts of Euphorbia hirta at doses of 1, 10 and 50 mg/kg, respectively, every alternate day for 50 days, while one group served as a control. The animals were later sacrificed and the liver, kidney and aorta harvested for examination by electron microscopy. The aorta showed no ultrastructural changes across the groups. Renal and hepatic tissue from the treated groups demonstrated dose-dependent injuries, which showed architectural damage beginning in the nuclei and spreading outwards. Taking into consideration the properties of Euphorbia hirta that have been described in previous studies, in addition to the results from the present study, it appears that the herb may exhibit similar effects to those of the quinolone group of antibiotics. Further in-depth investigations are required into the potential effects of Euphorbia hirta, deleterious and otherwise.
  17. Safari MJ, Wong JH, Kadir KA, Thorpe NK, Cutajar DL, Petasecca M, et al.
    Eur Radiol, 2016 Jan;26(1):79-86.
    PMID: 26002131 DOI: 10.1007/s00330-015-3818-9
    OBJECTIVES: To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures.

    METHODS: Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures.

    RESULTS: The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R(2)) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AKL: 0.93, AKF: 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions.

    CONCLUSIONS: The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose.

    KEY POINTS: Real-time patient dose monitoring helps interventionalists to monitor doses. Strong correlation was observed between kerma-area-product and measured eye doses. Radiation dose at left outer canthus was higher than at left eyelid.

  18. Goh CR, Lee KS, Tan TC, Wang TL, Tan CH, Wong J, et al.
    Ann Acad Med Singap, 1996 May;25(3):323-34.
    PMID: 8876896
    Quality-of-life assessment has become an accepted method of evaluation in clinical medicine. The technique is based on a patient's self-assessment of physical, psychological, and social function, as well as the effects of distressing physical symptoms. The most important aspect of quality-of-life assessment is that it brings into focus a patient-centred view of health outcome, which is broader than the physiologic measures which predominate in Western medicine. Strategies for the development and use of assessment questionnaires have evolved over the past 15 years, and numerous questionnaires have been created. Most originate in Western societies, with English as the most common language of development. Adapting such questionnaires for use in other language and cultural settings is an imprecise practice. Language translation and equivalent cultural meaning must both be addressed. This paper reports on the language translation process and results for the Functional Living Index for Cancer (FLIC) as translated into Chinese and Malay in Singapore. We employed a step-wise process beginning with translation/back translation, followed by structured pilot field trials and population sampling. Taped versions of the questionnaire were devised to meet illiteracy problems in the sample population. Paired comparisons of the Chinese and Malay versions of individual questions with their English counterparts show good correlations and similar means most of the time. Factor analysis on a population sample of 246 (112 Chinese, 35 Malay and 98 English speaking) with cancers of minimal, extensive or palliative extent is convergent with that obtained on a North American population. However, a separate analysis of the Chinese questionnaires showed some differences in factor pattern. Specific language and cultural translation difficulties are discussed. Of note is the predicted significant decrease in total FLIC scores with extent of disease within each of the language preference populations, which provides some evidence for the validity for each language version in the Singapore culture(s). Thus, the FLIC translations into Malay and Chinese in Singapore can be considered for use in local trials, subject to ongoing evaluation.
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