Displaying publications 1 - 20 of 24 in total

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  1. Leong, Yong Qi, Koh, R. Y., Chan, H. H., Leong, C. O.
    MyJurnal
    Introduction: Amyloid plaques, mainly comprising of amyloid-beta peptides derived from its precursor protein, are found deposited in hippocampal and entorhinal cortical regions of patients with Alzheimer’s disease (AD). However, none led to a complete understanding of the molecular mechanisms of the AD in order to generate a new therapy that would eradicate the disease effectively. Activation of pro-apoptotic pathway was found to be associated with the accumulation of amyloid precursor protein (APP). The objective of this study is to examine theeffects of APP overexpression on the Bcl-2 family proteins involving in pro-apoptotic pathway in neuronal cells. Methods: The experiment was first performed with the transfection of HEK 293T cells for generation of lentiviral vector system consisting APP plasmid followed by transduction of SH-SY5Y neuronal cells using lentivirus generated. Subsequently, western blot analysis was conducted to validate the APP overexpression in SH-SY5Y cells. Then, expression levels of Bcl-2 family proteins in the APP overexpressed cells were determined by western blot analysis. The statistical analysis was performed by Microsoft Excel with Student’s t-test. Results: APP overexpression in SH-SY5Y cells slightly upregulated the pro-apoptotic proteins including Bad, Bid, Bok and Puma but slightly downregulated Bcl-2, Bim and Bax. Conclusion: Our data suggest that APP overexpression regulated the Bcl-2-mediated pathway by a significant downregulation of Bim protein in neuronal cells.
  2. Pan, M. L., Koh, R. Y., Chan, H. H., Leong, C. O.
    MyJurnal
    Introduction: The aging process is the most significant risk factor for developing Alzheimer’s disease (AD). AD is the most common neurodegenerative disease that causes cognitive and memory impairment in the elderly. Excessive build-up of amyloid protein leads to cell death, brain atrophy, and cognitive and functional decline in AD. The nuclear factor kappa beta (NF-κB) is a family of inducible transcription factors composed of NF-κB1, NF-κB2, RelA, RelB and c-Rel. It is activated by genotoxic agents, as well as oxidative and inflammatory stresses. It regulates expression of genes that control apoptosis, cell cycle progression, cell senescence, and inflammation. NF-κB regulates amyloid precursor protein (APP) processing by activating transcription of β and γ secretases, which promotes amyloid dysregulation in AD. In addition, NF-κB activation is linked with many of the known lifespan regulators including insulin/IGF- 1, FOXO, SIRT, and mTOR. Therefore, NF-κB pathway contributes to the pathophysiology of AD. This study aims to evaluate the effects of APP overexpression on NF-κB pathway in neuronal cells. Methods: SH-SY5Y neuronal cells were transduced with APP plasmid. Overexpression of APP in the cells was validated by western blotting. Western blot analysis using antibodies targeting NF-κB signalling pathway was performed using the APP-overexpressed cells. Results: Overexpression of APP in cells caused a significant down-regulation of phosphorylated NF-κB. Overexpression of APP also slightly up-regulated IkappaB-alpha, IKK alpha, and IKK beta. Conclusion: APP overexpression affected NF-κB pathway by down-regulating NF-κB protein.
  3. Chan, H. Z., Wang, C. S., Azuhairy, A., Hau, A., Zulkiflee, O.
    Malays Orthop J, 2014;8(1):79-81.
    MyJurnal
    Primary sacral tumours are rare, therefore experience of managing their associated complications are very limited. Effective surgical treatment of pelvic chondrosarcoma remains a major challenge for orthopaedic surgeons, due to the complex anatomic structure of the pelvis, the lack of defined compartment borders, the close vicinity to vital structures, and the risk of jeopardizing pelvic structural stability. We report a rare case of a giant sacral chondrosarcoma (100cm x 80cm) in an elderly male who successfully underwent tumour resection with good functional outcome and recovery. Long term follow up is essential in view of the possibility of local tumour recurrence.
  4. Choong, C. Y. L., Chan, H. Z., Azuhairy, A., Anwar Hau, M., Zulkiflee, O.
    Malays Orthop J, 2014;8(2):55-58.
    MyJurnal
    Conventional chondrosarcomas rarely metastasize and it is extremely unusual to see multicentric- behaviour in malignant cartilage tumour. We report a 40 year old lady with presentation of two non-contiguous metachronous foci of low to intermediate grade of chondrosarcoma over left pelvic bone and right scalp respectively in the absence of pulmonary or visceral metastasis.
  5. Chan HH, Mustafa FF, Zairi J
    Trop Biomed, 2011 Aug;28(2):464-70.
    PMID: 22041770
    Routine surveillance on resistant status of field mosquito populations is important to implement suitable strategies in order to prevent pest outbreaks. WHO test kit bioassay is the most frequent bioassay used to investigate the susceptibility status of field-collected mosquitoes, as it is relatively convenient to be carried out in the field. In contrast, the topical application of active ingredient is less popular in investigating the susceptibility status of mosquitoes. In this study, we accessed the susceptibility status of Aedes albopictus Skuse collected from two dengue hotspots on Penang Island: Sungai Dua and Persiaran Mayang Pasir. Two active ingredients: permethrin and deltamethrin, were used. WHO test kit bioassay showed that both wild strains collected were susceptible to the two active ingredients; while topical application assay showed that they were resistant. This indicated that WHO test kit bioassay less sensitive to low level of resistance compared to topical application assay. Hence, topical application is expected to be more indicative when used in a resistance surveillance programme.
  6. Yuen P, Chan HL, Lee YS
    Singapore Med J, 2001 May;42(5):224-7.
    PMID: 11513062
    Sézary syndrome is a rare form of primary cutaneous T cell lymphoma. It is a distinct systemic variant of mycosis fungoides, marked by erythroderma, lymphadenopathy and circulating cerebriform lymphocytes in the peripheral blood. We report a case of Sézary syndrome in a 61-year-old Malay man with a five-year history of indurated plaques, ulcers and tumours on the head and trunk, with characteristic findings on physical examination, skin biopsy, electron microscopy, immunophenotyping and peripheral blood film. A literature review on Sézary syndrome is presented.
  7. Chan H, Wang C, Azuhairy A, Hau A, Zulkiflee O
    Malays Orthop J, 2014 Mar;8(1):79-81.
    PMID: 25347391 DOI: 10.5704/MOJ.1403.007
    Primary sacral tumours are rare, therefore experience of managing their associated complications are very limited. Effective surgical treatment of pelvic chondrosarcoma remains a major challenge for orthopaedic surgeons, due to the complex anatomic structure of the pelvis, the lack of defined compartment borders, the close vicinity to vital structures, and the risk of jeopardizing pelvic structural stability. We report a rare case of a giant sacral chondrosarcoma (100cm x 80cm) in an elderly male who successfully underwent tumour resection with good functional outcome and recovery. Long term follow up is essential in view of the possibility of local tumour recurrence.

    KEY WORDS: Giant Chondrosarcoma, Sacrum, Surgery, Elderly Male.

  8. Chang C, Chan H, Lim S, Khoo E, Zulkiflee O
    Malays Orthop J, 2014 Jul;8(2):49-51.
    PMID: 25279094 MyJurnal DOI: 10.5704/MOJ.1407.004
    Postoperative wound infection in an instrumented spine patient is often disastrous. Management includes implant removal leading to spine instability. Negative pressure wound therapy (NPWT) applied to the spine surgical wound is one of the wound care technique with successful results. We report a case of a man who sustained Chance fracture of Lumbar 1 (L1) vertebra treated with long segment posterior instrumentation, who unfortunately developed Extended-spectrum beta-lactamase (ESBL) positive E. coli infection one month after the operation. After careful debridement of the wound, the implant became exposed. Three cycles of NPWT were applied and the wound healed with granulation tissue completely covering the implant, and thus negating the need to remove the implant. In conclusion, the NPWT is a good alternative in postoperative wound management especially in an instrumented spine patient.
  9. Choong C, Chan H, Azuhairy A, Hau MA, Zulkiflee O
    Malays Orthop J, 2014 Jul;8(2):55-8.
    PMID: 25279096 DOI: 10.5704/MOJ.1407.006
    Conventional chondrosarcomas rarely metastasize and it is extremely unusual to see multicentric- behaviour in malignant cartilage tumour. We report a 40 year old lady with presentation of two non-contiguous metachronous foci of low to intermediate grade of chondrosarcoma over left pelvic bone and right scalp respectively in the absence of pulmonary or visceral metastasis.
  10. Chan H, Ooi C, Lim M, Ong E, Zulkiflee O
    Malays Orthop J, 2014 Jul;8(2):59-62.
    PMID: 25279097 MyJurnal DOI: 10.5704/MOJ.1407.007
    Shoulder impingement syndrome and acromioclavicular joint osteoarthritis often occur simultaneously and easily missed. Kay et al. reported excellent results with combined arthroscopic subacromial decompression and resection of the distal end of the clavicle in patients with both disorders(1). Arthroscopic treatment of these disorders produces more favourable results than open procedures. We report two patients who were not responding to conservative management and were treated with direct arthroscopic distal clavicle excision and subacromial decompression in single setting. Both patients gained good postoperative outcome in terms of pain score, function and strength improvement assessed objectively with visual analogue score (VAS) and University of California Los Angeles Score (UCLA).
  11. Chan HC, Adnan WA, Jaalam K, Abdullah MR, Abdullah J
    PMID: 16295557
    Mild head injury (MHI) is a common presentation to many hospitals in both rural and urban settings in Southeast Asia, but it is not well studied. We studied 330 patients that presented to Hospital Universiti Sains Malaysia Emergency Department with possible MHI, with the intentions to identify prognostic factors that may improve the diagnosis of MHI in the emergency setting as well as to determine which patients would need follow-up. Patients' one-year outcomes were classified as discharged well (DW) for patients without post-traumatic signs and symptoms and discharged with long term follow-up (DFU) for patients with such signs and symptoms. Four patients died and 82 were DFU. An abnormal skull X ray was associated with mode of accident and type of transportation, older age, presence of vomiting, confusion, bleeding from ear, nose or throat, abnormal pupil size on the right side associated with orbital trauma, unequal pupillary reflexes, absence of loss of consciousness (LOC), a lower Glasgow Coma Scale (GCS) score, multiple clinical presentations, and DFU. An abnormal CT scan was associated with older age, multiple clinical presentation, skull X-ray findings, and DFU. A similar analysis on outcomes revealed that mode of accident, older age, vomiting, confusion, headache, bleeding from ear, nose and throat, neurological deficits, absence of LOC, pupil size, multiple presentation, abnormal skull X ray, CT scan of the brain, and a GCS of 13 was associated with DFU. In conclusion, all patients involved in motor vehicle accidents (MVAs), especially motorcycles, aged over 30 years of age, with multiple clinical presentations, including a lower GCS, and with abnormal radiological findings should have a longer follow-up due to persistent post-traumatic symptomatology.
  12. Chan HK, Hassali MA, Lim CJ, Saleem F, Tan WL
    J Clin Pharm Ther, 2015 Jun;40(3):266-72.
    PMID: 25865563 DOI: 10.1111/jcpt.12272
    WHAT IS KNOWN AND OBJECTIVE: It has been reported that more than 80% of out-of-hospital medication errors among the young children involve liquid formulations. The usefulness of pictorial aids to improve communication of medication instructions has not been extensively investigated for child health. The objective of this study was to determine the effectiveness of pictorial aids used to assist caregivers in the administration of liquid medications.
    METHODS: MEDLINE, CINAHL, PsycINFO, ScienceDirect, Scopus and the Cochrane Library were searched for articles published up to February 2015. Studies that used pictorial aids with liquid medications and measured at least one of the following outcomes were included: dosing accuracy, comprehension of medication instructions, recall of information and adherence of caregivers. Two authors independently selected studies, extracted data and assessed methodological quality of studies using the Cochrane Collaboration's tool.
    RESULTS AND DISCUSSION: Five experimental studies (four hospital based and one community based) with a total of 962 participants were included. A wide range of liquid formulations were studied, including both prescription and over-the-counter medications. The existing findings suggest that pictographic interventions reduced dosing errors, enhanced comprehension and recall of medication instructions and improved adherence of caregivers. Incorporating pictorial aids into verbal medication counselling or text-based instructions was more beneficial than using the single approach alone. Mixed results were identified for the relationship between health literacy of caregivers and effectiveness of pictorial aids.
    WHAT IS NEW AND CONCLUSION: The evidence remains limited due to the small number of studies found and variations in methodological quality. This review suggests that pictorial aids might be potential interventions, but more high-quality studies are needed to support the routine use of any pictogram-based materials with liquid medications in the clinical settings.
    KEYWORDS: caregivers; graphics; health literacy; medication adherence; medication errors; paediatrics
  13. McMinn P, Lindsay K, Perera D, Chan HM, Chan KP, Cardosa MJ
    J Virol, 2001 Aug;75(16):7732-8.
    PMID: 11462047
    Enterovirus 71 (EV71) is a frequent cause of hand, foot, and mouth disease (HFMD) epidemics associated with severe neurological sequelae in a small proportion of cases. There has been a significant increase in EV71 epidemic activity throughout the Asia-Pacific region since 1997. Recent HFMD epidemics in this region have been associated with a severe form of brainstem encephalitis associated with pulmonary edema and high case fatality rates. In this study, we show that four genetic lineages of EV71 have been prevalent in the Asia-Pacific region since 1997, including two previously undescribed genogroups (B3 and B4). Furthermore, we show that viruses belonging to genogroups B3 and B4 have circulated endemically in Southeast Asia during this period and have been the primary cause of several large HFMD or encephalitis epidemics in Malaysia, Singapore, and Western Australia.
  14. Choong C, Chan HZ, Faruk NA, Bea KC, Zulkiflee O
    Malays Orthop J, 2015 Nov;9(3):49-51.
    PMID: 28611910 MyJurnal DOI: 10.5704/MOJ.1511.007
    Following a week after a jellyfish sting, a young man presented with regional cyanosis and threat of distal gangrene secondary to vascular spasm in the forearm. The patient also suffered from transient paresis and numbness of the affected upper limb. Contrasted imaging revealed unopacified vessels in the distal forearm and worsening swelling warranted emergency surgical fasciotomy for impending compartment syndrome. This case highlights the occurrence of jellyfish envenomation and the need for early treatment.
  15. Hoe CH, Suan MAM, Hoe CH, Tang TH, Kiew KK, Hassan MRA, et al.
    Med J Malaysia, 2018 08;73(4):260.
    PMID: 30121693
    No abstract provided.
  16. Tan KC, Chang CT, Cheah WK, Vinayak CR, Chan HK
    Med J Malaysia, 2019 Jun;74(3):215-218.
    PMID: 31256176
    INTRODUCTION: This study was designed to determine the influence of bariatric surgery on changes in the body mass index (BMI), and the control of diabetes, hypertension and dyslipidaemia among obese patients in Malaysia.

    MATERIALS AND METHODS: This was a retrospective cohort study undertaken at a public tertiary care centre in the state of Perak, Malaysia. Information of obese patients who underwent bariatric surgery was obtained from their medical records. The changes in the BMI, HbA1C, systolic and diastolic blood pressure (SBP and DBP), and lipid levels between three months before and after the surgery were assessed.

    RESULTS: The patients (n=106) were mostly Malay (66.0%), had at least one comorbidity (61.3%), and had a mean age of 40.38±11.75 years. Following surgery, the BMI of the patients was found to reduce by 9.78±5.82kg/m2. For the patients who had diabetes (n=24) and hypertension (n=47), their mean HbA1C, SBP and DBP were also shown to reduce significantly by 2.02±2.13%, 17.19±16.97mmHg, and 11.45±12.63mmHg, respectively. Meanwhile, the mean total cholesterol, triglyceride and low-density lipoprotein levels of those who had dyslipidaemia (n=21) were, respectively, lowered by 0.91±1.18mmol/L, 0.69±1.11mmol/L and 0.47±0.52mmol/L.

    CONCLUSION: The findings suggest that in addition to weight reduction, bariatric surgery is helpful in improving the diabetes, hypertension and dyslipidaemia control among obese patients. However, a large-scale trial with a control group is required to verify our findings.

  17. Mohd Suan MA, Chan HK, Sem XH, Shilton S, Abu Hassan MR
    Med J Malaysia, 2021 Nov;76(6):828-832.
    PMID: 34806668
    INTRODUCTION: A major challenge in providing hepatitis C virus (HCV) treatment at primary healthcare clinics is the lack of radiological facilities to guide the decision making of liver cirrhosis (LC). This study aimed to compare the performance of three commonly used cut-offs of the aspartate aminotransferase-to-platelet ratio index (APRI) in diagnosing LC among hepatitis C patients in Malaysia.

    METHODS: This cross-sectional study was based on the data collected from the Hepatitis C Elimination through Access to Diagnostics (HEAD-Start) study in 25 primary healthcare clinics across three regions of Malaysia. The findings of biochemical tests were used to calculate the APRI for each study participant. Transient elastography was used as a standard reference for the diagnosis of cirrhosis. The area under the receiver operating curve (AUROC) was used to determine the discriminative ability of APRI in both HCV mono-infected and HCV/HIV co-infected patients. The diagnostic performance of APRI at three different cutoffs (>1.0, ≥1.5 and >2.0) were also evaluated.

    RESULTS: This study included 867 HCV-RNA-positive patients, 158 (16.1%) were co-infected with HIV. For the HCV mono-infected patients, the sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) for the cut-off of >1.0 were 61.8%, 88.7%, 73.8% and 81.9%, and for the cut-off of ≥1.5, 45.6%, 97.0%, 88.7% and 77.6%, respectively. A much lower sensitivity (29.9%) was observed for the cut-off of >2.0. The diagnostic accuracy of APRI at the cut-off of ≥1.5 in the HCV/HIV co-infected patients was relatively suboptimal.

    CONCLUSION: APRI, with a cut-off of ≥1.5, can more accurately predict LC among hepatitis C patients in Malaysia. However, additional physical examination and laboratory assessment are likely to be required to support the diagnosis, especially in those with HCV/HIV co-infection.

  18. Chan HC, Aasim WA, Abdullah NM, Naing NN, Abdullah JM, Saffari MH, et al.
    Singapore Med J, 2005 May;46(5):219-23.
    PMID: 15858690
    Paediatric minor head injuries (MHI) are just as common in both bigger and smaller towns in Malaysia. Urban-based MHI are due more to motor vehicular injuries compared to rural-based MHI which are mainly due to non-motor vehicular injuries. The main objectives of this study were to compare incidence of admitted patients to accident and emergency departments of hospitals in two different settings in Malaysia, namely: Ipoh (urban-based) and Kota Bharu (rural-based); and to correlate to demographical characteristics, types of accident, clinical signs and symptoms, radiological and computed tomography (CT) findings, management; and finally, to determine clinical predictors of intracranial injury in MHI.
  19. Suan NAM, Soelar SA, Rani RA, Anuar NA, Aziz KAA, Chan HK, et al.
    Med J Malaysia, 2024 Mar;79(2):222-233.
    PMID: 38553930
    INTRODUCTION: Equitable healthcare delivery is essential and requires resources to be distributed, which include assets and healthcare workers. To date, there is no gold standard for measuring the correct number of physicians to meet healthcare needs. This rapid review aims to explore measurement tools employed to optimise the distribution of hospital physicians, with a focus on ensuring fair resource allocation for equitable healthcare delivery.

    MATERIALS AND METHODS: A literature search was performed across PubMed, EMBASE, Emerald Insight and grey literature sources. The key terms used in the search include 'distribution', 'method', and 'physician', focusing on research articles published in English from 2002 to 2022 that described methods or tools to measure hospital-based physicians' distribution. Relevant articles were selected through a two-level screening process and critically appraised. The primary outcome is the measurement tools used to assess the distribution of hospital-based physicians. Study characteristics, tool advantages and limitations were also extracted. The extracted data were synthesised narratively.

    RESULTS: Out of 7,199 identified articles, 13 met the inclusion criteria. Among the selected articles, 12 were from Asia and one from Africa. The review identified eight measurement tools: Gini coefficients and Lorenz curve, Robin Hood index, Theil index, concentration index, Workload Indicator of Staffing Need method, spatial autocorrelation analysis, mixed integer linear programming model and cohortcomponent model. These tools rely on fundamental data concerning population and physician numbers to generate outputs. Additionally, five studies employed a combination of these tools to gain a comprehensive understanding of physician distribution dynamics.

    CONCLUSION: Measurement tools can be used to assess physician distribution according to population needs. Nevertheless, each tool has its own merits and limitations, underscoring the importance of employing a combination of tools. The choice of measuring tool should be tailored to the specific context and research objectives.

  20. Sarin SK, Kumar M, Lau GK, Abbas Z, Chan HL, Chen CJ, et al.
    Hepatol Int, 2016 Jan;10(1):1-98.
    PMID: 26563120 DOI: 10.1007/s12072-015-9675-4
    Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.
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