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  1. Ruzanna ZZ, Ong LY, Cheah YC, Fairuz A, Midin M
    Med J Malaysia, 2012 Feb;67(1):39-44.
    PMID: 22582547 MyJurnal
    This cross sectional study aimed to explore the association between dyslipidaemia and types of antipsychotics in 100 patients with chronic schizophrenia. Lipid profile, weight, height and waist circumference together with other relevant factors were measured. We found there was a high rate of dyslipidaemia among patients with chronic schizophrenia treated with antipsychotics (66%), however there was no significant difference found between typical or atypical antipsychotics (OR=1). All sociodemographic and clinical factors were not significantly associated with dyslipidaemia. Only non-Malays were found to have significant dyslipidaemia (p<0.1). Effective management is needed to deal with the dyslipidaemia in this group.
  2. Ng GYH, Nah SA, Teoh OH, Ong LY
    Pediatr Surg Int, 2020 Mar;36(3):383-389.
    PMID: 31993738 DOI: 10.1007/s00383-020-04619-x
    BACKGROUND: The risk factors for recurrence in primary spontaneous pneumothorax (PSP) in children are not well known. We aimed to identify possible risk factors, and to evaluate the utility of computerised tomography (CT) scans in predicting future episodes.

    METHODS: We reviewed children aged 

  3. Low CC, Ong LY, Koo VC, Leow MC
    Heliyon, 2020 Sep;6(9):e05107.
    PMID: 33024875 DOI: 10.1016/j.heliyon.2020.e05107
    Digital signage is widely utilized in digital-out-of-home (DOOH) advertising for marketing and business. Recently, the combination of the digital camera and digital signage enables the advertiser to gather the audience demographic for audience measurement. Audience measurement is useful for the advertiser to understand the audience's behavior and improve their business strategies. When an audience is facing the digital display, the vision-based DOOH system will process the audience's face and broadcast a personalized advertisement. Most of the digital signage is available in an uncontrolled environment of public areas. Thus, it poses two main challenges for the vision-based DOOH system to track the audience's movement, which are multiple adjacent faces and occlusion by passer-by. In this paper, a new framework is proposed to combine the digital signage with a depth camera for tracking multi-face in the three-dimensional (3D) environment. The proposed framework extracts the audience's face centroid position (x, y) and depth information (z) and plots into the aerial map to simulate the audience's movement that is corresponding to the real-world environment. The advertiser can further measure the advertising effectiveness through the audience's behavior.
  4. Ong LY, Pang T, Lim SH, Tan EL, Puthucheary SD
    J Med Microbiol, 1989 Jul;29(3):195-8.
    PMID: 2473209
    A simple adherence test to detect IgM antibodies in patients with typhoid is described. The test utilises the IgM-"capture" approach, in which the test serum is applied to microtitration plate wells previously coated with anti-human IgM, followed by application of a stained Salmonella typhi antigen suspension which shows adherence in positive cases. By this test, 58 (95%) of 61 sera from confirmed cases of typhoid possessed IgM antibodies to the H or O or both antigens of S. typhi. In patients for whom a diagnosis of typhoid was based only on a significant Widal-test titre, 31 (41%) of 76 sera had IgM antibodies to the H or O or both antigens of S. typhi. Some cross-reactivity of the IgM antibodies was detected, especially with the O antigens of S. paratyphi A and B. A total of 82 sera from non-typhoidal fevers (leptospirosis, typhus, dengue fever) showed no reactivity in this test. In normal sera there was no detectable IgM to the O antigen of S. typhi and only a small number (3.9%) had low levels of IgM to the H antigen. The significance and potential importance of this simple, sensitive, specific and economical test is discussed.
  5. Chook JB, Ong LY, Takebe Y, Chan KG, Choo M, Kamarulzaman A, et al.
    Am J Trop Med Hyg, 2015 Mar;92(3):507-512.
    PMID: 25535315 DOI: 10.4269/ajtmh.14-0681
    A molecular genotyping assay for human immunodeficiency virus type 1 (HIV-1) circulating in Southeast Asia is difficult to design because of the high level of genetic diversity. We developed a multiplex real-time polymerase chain reaction (PCR) assay to detect subtype B, CRF01_AE, CRF33_01B, and three newly described circulating recombinant forms, (CRFs) (CRF53_01B, CRF54_01B, and CRF58_01B). A total of 785 reference genomes were used for subtype-specific primers and TaqMan probes design targeting the gag, pol, and env genes. The performance of this assay was compared and evaluated with direct sequencing and phylogenetic analysis. A total of 180 HIV-infected subjects from Kuala Lumpur, Malaysia were screened and 171 samples were successfully genotyped, in agreement with the phylogenetic data. The HIV-1 genotype distribution was as follows: subtype B (16.7%); CRF01_AE (52.8%); CRF33_01B (24.4%); CRF53_01B (1.1%); CRF54_01B (0.6%); and CRF01_AE/B unique recombinant forms (4.4%). The overall accuracy of the genotyping assay was over 95.0%, in which the sensitivities for subtype B, CRF01_AE, and CRF33_01B detection were 100%, 100%, and 97.7%, respectively. The specificity of genotyping was 100%, inter-subtype specificities were > 95% and the limit of detection of 10(3) copies/mL for plasma. The newly developed real-time PCR assay offers a rapid and cost-effective alternative for large-scale molecular epidemiological surveillance for HIV-1.
  6. Ng KT, Ong LY, Lim SH, Takebe Y, Kamarulzaman A, Tee KK
    PLoS One, 2013;8(6):e67286.
    PMID: 23840653 DOI: 10.1371/journal.pone.0067286
    HIV-1 epidemics among men who have sex with men (MSM) continue to expand in developed and developing countries. Although HIV infection in MSM is amongst the highest of the key affected populations in many countries in Southeast Asia, comprehensive molecular epidemiological study of HIV-1 among MSM remains inadequate in the region including in Malaysia. Here, we reported the phylodynamic profiles of HIV-1 genotypes circulating among MSM population in Kuala Lumpur, Malaysia. A total of n = 459 newly-diagnosed treatment-naïve consenting subjects were recruited between March 2006 and August 2012, of whom 87 (18.9%) were self-reported MSM. Transmitted drug resistance mutations were absent in these isolates. Cumulatively, phylogenetic reconstructions of the pro-rt gene (HXB2∶2253-3275) showed that HIV-1 subtype B and CRF01_AE were predominant and contributed to approximately 80% of the total HIV-1 infection among MSM. In addition to numerous unique transmission lineages within these genotypes, twelve monophyletic transmission clusters of different sizes (2-7 MSM sequences, supported by posterior probability value of 1) were identified in Malaysia. Bayesian coalescent analysis estimated that the divergence times for these clusters were mainly dated between 1995 and 2005 with four major transmission clusters radiating at least 12 years ago suggesting that active spread of multiple sub-epidemic clusters occurred during this period. The changes in effective population size of subtype B showed an exponential growth within 5 years between 1988 and 1993, while CRF01_AE lineage exhibited similar expansion between 1993 and 2003. Our study provides the first insight of the phylodynamic profile of HIV-1 subtype B and CRF01_AE circulating among MSM population in Kuala Lumpur, Malaysia, unravelling the importance of understanding transmission behaviours as well as evolutionary history of HIV-1 in assessing the risk of outbreak or epidemic expansion.
  7. Ng KT, Ong LY, Takebe Y, Kamarulzaman A, Tee KK
    J Virol, 2012 Oct;86(20):11405-6.
    PMID: 22997423
    We report here the first novel HIV-1 circulating recombinant form (CRF) 54_01B (CRF54_01B) isolated from three epidemiologically unlinked subjects of different risk groups in Malaysia. These recently sampled recombinants showed a complex genome organization composed of parental subtype B' and CRF01_AE, with identical recombination breakpoints observed in the gag, pol, and vif genes. Such a discovery highlights the ongoing active generation and spread of intersubtype recombinants involving the subtype B' and CRF01_AE lineages and indicates the potential of the new CRF in bridging HIV-1 transmission among different risk groups in Southeast Asia.
  8. Chow WZ, Lim SH, Ong LY, Yong YK, Takebe Y, Kamarulzaman A, et al.
    PLoS One, 2015;10(9):e0137281.
    PMID: 26335136 DOI: 10.1371/journal.pone.0137281
    Human immunodeficiency virus type 1 (HIV-1) subtypes have been shown to differ in the rate of clinical progression. We studied the association between HIV-1 subtypes and the rate of CD4+ T-cell recovery in a longitudinal cohort of patients on combination antiretroviral therapy (cART). We studied 103 patients infected with CRF01_AE (69%) and subtype B (31%) who initiated cART between 2006 and 2013. Demographic data, CD4+ T-cell counts and HIV-1 viral load were abstracted from patient medical charts. Kaplan-Meier was used to estimate the time to CD4+ T-cell count increase to ≥350 between subtypes and effects of covariates were analysed using Cox proportional hazards. An 87% of the study population were male adults (mean age of 38.7 years old). Baseline CD4+ T-cell counts and viral loads, age at cART initiation, sex, ethnicity and co-infection did not differ significantly between subtypes. A shorter median time for CD4+ T-cell count increase to ≥350 cells/μL was observed for CRF01_AE (546 days; 95% confidence interval [CI], 186-906 days; P = .502) compared to subtype B (987 days; 95% CI, 894-1079 days). In multivariate analysis, female sex was significantly associated with a 2.7 times higher chance of achieving CD4+ T-cell recovery (adjusted hazard ratio [HR], 2.75; 95% CI, 1.21-6.22; P = .025) and both baseline CD4+ T-cell count (P = .001) and viral load (P = .001) were important predictors for CD4+ T-cell recovery. Immunological recovery correlated significantly with female sex, baseline CD4+ T-cell counts and viral load but not subtype.
  9. Lee CE, Sri Ponnampalavanar S, Syed Omar SF, Mahadeva S, Ong LY, Kamarulzaman A
    Ann Acad Med Singap, 2011 Oct;40(10):448-53.
    PMID: 22206053 DOI: 10.47102/annals-acadmedsg.V40N10p448
    INTRODUCTION: Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter.

    MATERIALS AND METHODS: A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard.

    RESULTS: For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs.

    CONCLUSION: DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.
  10. Kyaw L, Choo CSC, Ong LY, Yap TL, Teo HJ, Nah SA
    Singapore Med J, 2023 Apr;64(4):249-254.
    PMID: 35196848 DOI: 10.11622/smedj.2022032
    INTRODUCTION: Doppler scrotal ultrasonography (US) is the modality of choice in diagnosing testicular torsion. We aimed to evaluate the performance of scrotal US in diagnosing testicular torsion over the past 18 years in our institution and determine the factors contributing to the length of wait times for it.

    METHODS: A retrospective review was conducted of boys who presented with acute scrotal pain from 2014 to 2015. US reports, operative findings, final diagnosis and key time points of the patients' journey (time to emergency department consultation, time to admission, time to US and time to operating theatre [OT]) were collected. US performance results were compared with those observed in a historical cohort from 1998 to 2004. Wait times were compared between operated and non-operated patients.

    RESULTS: Data from 519 boys with a mean age of 9.15 years was collected. Of these, 438 (84.4%) boys had undergone initial scrotal US; of these scrotal US cases, 28 were surgically explored, with 23 confirmed to have torsion. Another five cases were explored without prior US, and all were confirmed to have torsion. Performance analysis of US showed a sensitivity of 100% and a specificity of 98.8%. There was no significant difference between wait times of operated and non-operated patients. Time to US (P < 0.0001, r = 0.96) and time to OT (P < 0.0001, r = 0.64) correlated significantly with the total time from presentation to surgery.

    CONCLUSION: There has been an improvement in the diagnostic performance of scrotal US for testicular torsion over the past 18 years. Quality improvement programmes targeted at reducing wait times for patients presenting with acute scrotum should target time to US and time to OT.

  11. Cheong HT, Ng KT, Ong LY, Chook JB, Chan KG, Takebe Y, et al.
    PLoS One, 2014;9(10):e111236.
    PMID: 25340817 DOI: 10.1371/journal.pone.0111236
    A novel HIV-1 recombinant clade (CRF51_01B) was recently identified among men who have sex with men (MSM) in Singapore. As cases of sexually transmitted HIV-1 infection increase concurrently in two socioeconomically intimate countries such as Malaysia and Singapore, cross transmission of HIV-1 between said countries is highly probable. In order to investigate the timeline for the emergence of HIV-1 CRF51_01B in Singapore and its possible introduction into Malaysia, 595 HIV-positive subjects recruited in Kuala Lumpur from 2008 to 2012 were screened. Phylogenetic relationship of 485 amplified polymerase gene sequences was determined through neighbour-joining method. Next, near-full length sequences were amplified for genomic sequences inferred to be CRF51_01B and subjected to further analysis implemented through Bayesian Markov chain Monte Carlo (MCMC) sampling and maximum likelihood methods. Based on the near full length genomes, two isolates formed a phylogenetic cluster with CRF51_01B sequences of Singapore origin, sharing identical recombination structure. Spatial and temporal information from Bayesian MCMC coalescent and maximum likelihood analysis of the protease, gp120 and gp41 genes suggest that Singapore is probably the country of origin of CRF51_01B (as early as in the mid-1990s) and featured a Malaysian who acquired the infection through heterosexual contact as host for its ancestral lineages. CRF51_01B then spread rapidly among the MSM in Singapore and Malaysia. Although the importation of CRF51_01B from Singapore to Malaysia is supported by coalescence analysis, the narrow timeframe of the transmission event indicates a closely linked epidemic. Discrepancies in the estimated divergence times suggest that CRF51_01B may have arisen through multiple recombination events from more than one parental lineage. We report the cross transmission of a novel CRF51_01B lineage between countries that involved different sexual risk groups. Understanding the cross-border transmission of HIV-1 involving sexual networks is crucial for effective intervention strategies in the region.
  12. Chow WZ, Nizam S, Ong LY, Ng KT, Chan KG, Takebe Y, et al.
    Genome Announc, 2014;2(2).
    PMID: 24675847 DOI: 10.1128/genomeA.00139-14
    A complex HIV-1 unique recombinant form involving subtypes CRF01_AE, B, and B' was recently identified from an injecting drug user in Malaysia. A total of 13 recombination breakpoints were mapped across the near-full-length genome of isolate 10MYPR226, indicating the increasingly diverse molecular epidemiology and frequent linkage among various high-risk groups.
  13. Ong LY, Razak SN, Lee YM, Sri La Sri Ponnampalavanar S, Syed Omar SF, Azwa RI, et al.
    J Med Virol, 2014 Jan;86(1):38-44.
    PMID: 24127302 DOI: 10.1002/jmv.23772
    Expansion of antiretroviral treatment programs have led to the growing concern for the development of antiretroviral drug resistance. The aims were to assess the prevalence of drug resistant HIV-1 variants and to identify circulating subtypes among HAART-naïve patients. Plasma specimens from N = 100 HIV+ HAART-naïve adult were collected between March 2008 and August 2010 and viral RNA were extracted for nested PCR and sequenced. PR-RT sequences were protein aligned and checked for transmitted drug resistance mutations. Phylogenetic reconstruction and recombination analysis were performed to determine the genotypes. Based on the WHO consensus guidelines, none of the recruited patients had any transmitted drug resistance mutations. When analyzed against the Stanford guidelines, 35% of patients had at least one reported mutation that may reduce drug susceptibility to PI (24%), NRTI (5%), and NNRTI (14%). The commonly detected mutation that may affect current first line therapy was V179D (3%), which may lead to reduced susceptibility to NNRTI. The predominant circulating HIV-1 genotypes were CRF01_AE (51%) and CRF33_01B (17%). The prevalence of unique recombinant forms (URF) was 7%; five distinct recombinant structures involving CRF01_AE and subtype B' were observed, among them a cluster of three isolates that could form a novel circulating recombinant form (CRF) candidate. Transmitted drug resistance prevalence among HAART-naïve patients was low in this cohort of patients in Kuala Lumpur despite introduction of HAART 5 years ago. Owing to the high genetic diversity, continued molecular surveillance can identify the persistent emergence of HIV-1 URF and novel CRF with significant epidemiological impact.
  14. Cheong HT, Ng KT, Ong LY, Takebe Y, Chan KG, Koh C, et al.
    Genome Announc, 2015;3(6).
    PMID: 26543107 DOI: 10.1128/genomeA.01220-15
    Three strains of HIV-1 unique recombinant forms (URFs) descended from subtypes B, B', and CRF01_AE were identified among people who inject drugs in Kuala Lumpur, Malaysia. These three URFs shared a common recombination breakpoint in the reverse transcriptase region, indicating frequent linkage within the drug-injecting networks in Malaysia.
  15. Wang B, Lau KA, Ong LY, Shah M, Steain MC, Foley B, et al.
    Virology, 2007 Oct 25;367(2):288-97.
    PMID: 17604072
    The HIV protease-reverse transcriptase (PR-RT) (1047 bp), gp120-env (891 bp) and gp41-env (547 bp) regions from the plasma of 115 HIV-1-infected patients in Kuala Lumpur (KL), Malaysia were sequenced. Detailed phylogenetic and bootscanning analyses were performed to determine the mosaic structure of the HIV-1 strains and their recombination breakpoint(s). Among the 50 patient samples in which all three regions could be amplified, the HIV-1 CRF01_AE subtype (46%) was predominant followed by subtypes B (10%) and B' (6%). A total of 9/50 (18%) patients were infected with a CRF01_AE/B inter-subtype recombinant, displaying a recombinant form (RF)(PR-RT), CRF01_AE(gp120-env) and CRF01_AE(gp41-env). This RF was derived from the Thai variants of CRF01_AE and B' subtype, with two distinct B' subtype segments in the backbone of CRF01_AE, similar to the newly identified CRF33_01B. In addition, one sample demonstrated a close structural relationship with the new CRF33_01B in the PR-RT region but displayed B' segment in part of the env region (RF(PR-RT), CRF01_AE/B'(gp120-env) and B'(gp41-env)) indicating continuing evolution of CRF33_01B. The remaining 18% of samples were identified as unique recombinant forms (URFs).
  16. Chow WZ, Ong LY, Razak SH, Lee YM, Ng KT, Yong YK, et al.
    PLoS One, 2013;8(5):e62560.
    PMID: 23667490 DOI: 10.1371/journal.pone.0062560
    Since the discovery of HIV-1 circulating recombinant form (CRF) 33_01B in Malaysia in the early 2000 s, continuous genetic diversification and active recombination involving CRF33_01B and other circulating genotypes in the region including CRF01_AE and subtype B' of Thai origin, have led to the emergence of novel CRFs and unique recombinant forms. The history and magnitude of CRF33_01B transmission among various risk groups including people who inject drugs (PWID) however have not been investigated despite the high epidemiological impact of CRF33_01B in the region. We update the most recent molecular epidemiology of HIV-1 among PWIDs recruited in Malaysia between 2010 and 2011 by population sequencing and phylogenetic analysis of 128 gag-pol sequences. HIV-1 CRF33_01B was circulating among 71% of PWIDs whilst a lower prevalence of other previously dominant HIV-1 genotypes [subtype B' (11%) and CRF01_AE (5%)] and CRF01_AE/B' unique recombinants (13%) were detected, indicating a significant shift in genotype replacement in this population. Three clusters of CRF01_AE/B' recombinants displaying divergent yet phylogenetically-related mosaic genomes to CRF33_01B were identified and characterized, suggestive of an abrupt emergence of multiple novel CRF clades. Using rigorous maximum likelihood approach and the Bayesian Markov chain Monte Carlo (MCMC) sampling of CRF33_01Bpol sequences to elucidate the past population dynamics, we found that the founder lineages of CRF33_01B were likely to have first emerged among PWIDs in the early 1990 s before spreading exponentially to various high and low-risk populations (including children who acquired infections from their mothers) and later on became endemic around the early 2000 s. Taken together, our findings provide notable genetic evidence indicating the widespread expansion of CRF33_01B among PWIDs and into the general population. The emergence of numerous previously unknown recombinant clades highlights the escalating genetic complexity of HIV-1 in the Southeast Asian region.
  17. Ducey J, Lansdale N, Gorst S, Bray L, Teunissen N, Cullis P, et al.
    BMJ Paediatr Open, 2024 Feb 05;8(1).
    PMID: 38316469 DOI: 10.1136/bmjpo-2023-002262
    INTRODUCTION: Heterogeneity in reported outcomes of infants with oesophageal atresia (OA) with or without tracheo-oesophageal fistula (TOF) prevents effective data pooling. Core outcome sets (COS) have been developed for many conditions to standardise outcome reporting, facilitate meta-analysis and improve the relevance of research for patients and families. Our aim is to develop an internationally-agreed, comprehensive COS for OA-TOF, relevant from birth through to transition and adulthood.

    METHODS AND ANALYSIS: A long list of outcomes will be generated using (1) a systematic review of existing studies on OA-TOF and (2) qualitative research with children (patients), adults (patients) and families involving focus groups, semistructured interviews and self-reported outcome activity packs. A two-phase Delphi survey will then be completed by four key stakeholder groups: (1) patients (paediatric and adult); (2) families; (3) healthcare professionals; and (4) researchers. Phase I will include stakeholders individually rating the importance and relevance of each long-listed outcome using a 9-point Likert scale, with the option to suggest additional outcomes not already included. During phase II, stakeholders will review summarised results from phase I relative to their own initial score and then will be asked to rescore the outcome based on this information. Responses from phase II will be summarised using descriptive statistics and a predefined definition of consensus for inclusion or exclusion of outcomes. Following the Delphi process, stakeholder experts will be invited to review data at a consensus meeting and agree on a COS for OA-TOF.

    ETHICS AND DISSEMINATION: Ethical approval was sought through the Health Research Authority via the Integrated Research Application System, registration no. 297026. However, approval was deemed not to be required, so study sponsorship and oversight were provided by Alder Hey Children's NHS Foundation Trust. The study has been prospectively registered with the COMET Initiative. The study will be published in an open access forum.

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