Displaying publications 1 - 20 of 86 in total

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  1. Tan SY, Tan CY, Yahya MA, Low SC, Shahrizaila N, Goh KJ
    Neurol Sci, 2024 Jan 25.
    PMID: 38270729 DOI: 10.1007/s10072-024-07340-y
    INTRODUCTION: There is an increasing need for a reproducible and sensitive outcome measure in patients with hereditary transthyretin amyloidosis (ATTRv) with polyneuropathy (PN) due to the emergence of disease modifying therapies. In the current study, we aimed to investigate the role of quantitative muscle ultrasound (QMUS) as a disease biomarker in ATTRv-PN.

    METHODS: Twenty genetically confirmed ATTRv amyloidosis patients (nine symptomatic, 11 pre-symptomatic) were enrolled prospectively between January to March 2023. Muscle ultrasound was performed on six muscles at standardized locations. QMUS parameters included muscle thickness (MT) and muscle echo intensity (EI). Twenty-five age- and sex-matched healthy controls were recruited for comparison. Significant QMUS parameters were correlated with clinical outcome measures.

    RESULTS: Muscle volume of first dorsal interosseus (FDI) muscle [measured as cross-sectional area (CSA)] was significantly lower in symptomatic patients compared to healthy controls and pre-symptomatic carriers (98.3 ± 58.0 vs. 184.4 ± 42.5 vs. 198.3 ± 56.8, p 

  2. Hue SS, Jin Y, Cheng H, Bin Masroni MS, Tang LWT, Ho YH, et al.
    Cancers (Basel), 2023 Jan 10;15(2).
    PMID: 36672402 DOI: 10.3390/cancers15020453
    Accurate diagnosis of the most common histological subtypes of small B-cell lymphomas is challenging due to overlapping morphological features and limitations of ancillary testing, which involves a large number of immunostains and molecular investigations. In addition, a common diagnostic challenge is to distinguish reactive lymphoid hyperplasia that do not require additional stains from such lymphomas that need ancillary investigations. We investigated if tissue-specific microRNA (miRNA) expression may provide potential biomarkers to improve the pathology diagnostic workflow. This study seeks to distinguish reactive lymphoid proliferation (RL) from small B-cell lymphomas, and to further distinguish the four main subtypes of small B-cell lymphomas. Two datasets were included: a discovery cohort (n = 100) to screen for differentially expressed miRNAs and a validation cohort (n = 282) to develop classification models. The models were evaluated for accuracy in subtype prediction. MiRNA gene set enrichment was also performed to identify differentially regulated pathways. 306 miRNAs were detected and quantified, resulting in 90-miRNA classification models from which smaller panels of miRNAs biomarkers with good accuracy were derived. Bioinformatic analysis revealed the upregulation of known and other potentially relevant signaling pathways in such lymphomas. In conclusion, this study suggests that miRNA expression profiling may serve as a promising tool to aid the diagnosis of common lymphoid lesions.
  3. Ahmad T, Sethupathi S, Bashir MJK, Tan SY
    Environ Technol, 2022 Dec 12.
    PMID: 36428222 DOI: 10.1080/09593330.2022.2152735
    Oil palm fibre is a type of solid waste generated from palm oil processing plant. At present, there is no proper utilization of this abundant waste. Ammoniacal nitrogen (NH3-N) has received a lot of attention as a water pollutant due to its toxicity, which has an impact on both the environment and human health. In aquaculture wastewater (AQW), NH3-N is present in low concentrations (<10 ppm), and removing low concentrations of NH3-N is tedious. Thus, this study focuses on the potential of oil palm fibre biochar (OPFB) for sustainable low concentration NH3-N recovery from AQW and the recovered spent adsorbent to be used as a bio-fertilizer. The Physico-chemical properties of OPFB show a positive correlation with NH3-N recovery. A significant reduction of value-added metals in OPFB has confirmed the recovery of NH3-N through the ion exchange process. The adsorption isotherms and kinetics of NH3-N recovery had good correlation coefficients under the Freundlich and pseudo-second-order kinetic model confirming a multilayer heterogeneous and chemical adsorption respectively. Thermodynamic parameters indicated that the recovery process via adsorption was exothermic and had a Physio-chemical mechanism. At optimum conditions, OPFB could recover up to 66% of NH3-N actual AQW. The properties of spent OPFB showed potential reutilization as a soil amendment agent or biofertilizer which could be easily degraded.
  4. Wong LP, Alias H, Danaee M, Ahmed J, Lachyan A, Cai CZ, et al.
    Infect Dis Poverty, 2021 Oct 07;10(1):122.
    PMID: 34620243 DOI: 10.1186/s40249-021-00900-w
    BACKGROUND: The availability of various types of COVID-19 vaccines and diverse characteristics of the vaccines present a dilemma in vaccination choices, which may result in individuals refusing a particular COVID-19 vaccine offered, hence presenting a threat to immunisation coverage and reaching herd immunity. The study aimed to assess global COVID-19 vaccination intention, vaccine characteristics influencing vaccination acceptance and desirable vaccine characteristics influencing the choice of vaccines.

    METHODS: An anonymous cross-sectional survey was conducted between 4 January and 5 March 2021 in 17 countries worldwide. Proportions and the corresponding 95% confidence intervals (CI) of COVID-19 vaccine acceptance and vaccine characteristics influencing vaccination acceptance were generated and compared across countries and regions. Multivariable logistic regression analysis was used to determine the factors associated with COVID-19 vaccine hesitancy.

    RESULTS: Of the 19,714 responses received, 90.4% (95% CI 81.8-95.3) reported likely or extremely likely to receive COVID-19 vaccine. A high proportion of likely or extremely likely to receive the COVID-19 vaccine was reported in Australia (96.4%), China (95.3%) and Norway (95.3%), while a high proportion reported being unlikely or extremely unlikely to receive the vaccine in Japan (34.6%), the U.S. (29.4%) and Iran (27.9%). Males, those with a lower educational level and those of older age expressed a higher level of COVID-19 vaccine hesitancy. Less than two-thirds (59.7%; 95% CI 58.4-61.0) reported only being willing to accept a vaccine with an effectiveness of more than 90%, and 74.5% (95% CI 73.4-75.5) said they would accept a COVID-19 vaccine with minor adverse reactions. A total of 21.0% (95% CI 20.0-22.0) reported not accepting an mRNA vaccine and 51.8% (95% CI 50.3-53.1) reported that they would only accept a COVID-19 vaccine from a specific country-of-origin. Countries from the Southeast Asia region reported the highest proportion of not accepting mRNA technology. The highest proportion from Europe and the Americas would only accept a vaccine produced by certain countries. The foremost important vaccine characteristic influencing vaccine choice is adverse reactions (40.6%; 95% CI 39.3-41.9) of a vaccine and effectiveness threshold (35.1%; 95% CI 33.9-36.4).

    CONCLUSIONS: The inter-regional and individual country disparities in COVID-19 vaccine hesitancy highlight the importance of designing an efficient plan for the delivery of interventions dynamically tailored to the local population.

  5. Tan SY, Bastion MC, Mohd Khialdin S
    Cureus, 2021 Jul;13(7):e16275.
    PMID: 34373823 DOI: 10.7759/cureus.16275
    Orbital metastasis from renal cell carcinoma (RCC) is uncommon. Orbital tumor, as the first presentation of RCC, is rare as the majority of orbital metastases occur after a confirmed diagnosis of primary cancer. We report a case of the metastatic orbital tumor as the first manifestation of RCC, which presented with painless left eye proptosis for two months' duration, associated with blurring of vision and diplopia. Otherwise, the systemic review was unremarkable. Examination showed left eye non-axial proptosis with a pulsatile, multilobulated mass over the left supraorbital area extending to the left frontal region, limited ocular motility, and impaired optic nerve functions. CT of the orbit showed a mass arising from the left frontal and greater wing of the left sphenoid bone, with infiltration to the left lateral rectus, left superior oblique, and lacrimal gland. Further systemic investigation with CT thorax, abdomen, and pelvis revealed left RCC with para-aortic nodes, lungs, and bone metastases. The patient was planned for palliative care.
  6. Gan CC, Jalalonmuhali M, Nordin NZ, Abdul Wahab MZ, Yahya R, Ng KP, et al.
    Transplant Proc, 2021 Apr;53(3):856-864.
    PMID: 33487455 DOI: 10.1016/j.transproceed.2020.10.038
    Malaysia has a low deceased-donor donation rate and has not embarked on a paired kidney exchange program; therefore, ABO-incompatible and HLA-incompatible transplantation remain the main contributor to the sustainability of the national kidney transplantation (KT) program. There were 26 cases of ABO-incompatible KTs performed from 2011 to 2018 in 3 major transplant centers, namely, Hospital Kuala Lumpur, University Malaya Medical Centre, and Prince Court Medical Centre. We collected perioperative and follow-up data through June 2019. The desensitization protocol varies and is center specific: the localized Japanese protocol and Swedish protocol with a target anti-A/B isoagglutinin titer of 16 or 32 on the day of transplant. The induction and tacrolimus-based maintenance protocol was nearly identical. The median follow-up time was 62.3 months (interquartile range, 37.0-79.7). Fifteen subjects had the highest predesensitization anti-A/B titer of ≥32 (57.7%). The acute cellular rejection and antibody-mediated rejection incidence were 12.5% (3 cases) and 8.3% (2 cases), respectively. Patient, graft, and death-censored graft survival rates were 96.2%, 92.3%, and 96.0%, respectively, 1 year post-living-donor KT (LDKT) and 96.2%, 87.2%, and 90.7%, respectively, 5 years post-LDKT. Our experience shows that ABO-incompatible LDKT using a suitable desensitization technique could be a safe and feasible choice for LDKT even with varied desensitization regimens for recipients with relatively high baseline isoagglutinin titers.
  7. Tan SY, Md Din N, Mohd Khialdin S, Wan Abdul Halim WH, Tang SF
    Cureus, 2021 Feb 12;13(2):e13320.
    PMID: 33738163 DOI: 10.7759/cureus.13320
    The hazy corneal donor-recipient interface after corneal transplant may cause difficulties when implanting the XEN gel stent via ab-interno approach. We aim to describe XEN gel stent implantation via ab-externo approach in refractory steroid-induced glaucoma after corneal lamellar keratoplasty. Under local anaesthesia, the XEN injector needle was inserted 7 mm behind the limbus with the bevel facing up, directly beneath the conjunctiva and advanced to the marked 2.5 mm scleral entry wound. The needle then pierced the sclera until the needle tip was just visible in the anterior chamber (AC). The slider was pushed until the tip of the XEN stent was seen in the AC. The needle was slowly withdrawn while still pushing the slider to complete stent deployment. Subconjunctival Mitomycin C 0.01% (30 µg/0.3 mL) was then injected posterior to the bleb. Three eyes of three patients with steroid-induced glaucoma after lamellar keratoplasty underwent XEN gel stent implantation via ab-externo approach placed at the superotemporal quadrant. Pre-operatively, all patients had uncontrolled IOP between 30-45 mmHg despite maximum medications and selective laser trabeculoplasty. After XEN gel stent implantation, IOP ranged between 10-17 mmHg with one or two topical antiglaucoma at 12 months. Complications include hypotony maculopathy, stent migration and hyphaema, all of which were successfully managed. Corneal graft remained clear at 12 months. XEN gel stent implantation via ab-externo approach is able to achieve good intraocular pressure (IOP) control without compromising cornea graft in patients with steroid-induced glaucoma after lamellar keratoplasty at 12 months.
  8. Tan SY, Tay NNW
    F1000Res, 2021;10:987.
    PMID: 37767360 DOI: 10.12688/f1000research.72948.2
    Background: Educators often face difficulties in explaining abstract concepts such as vectors. During the ongoing coronavirus disease 2019 (COVID-19) pandemic, fully online classes have also caused additional challenges to using conventional teaching methods. To explain a vector concept of more than 2 dimensions, visualization becomes a problem. Although Microsoft PowerPoint can integrate animation, the illustration is still in 2-dimensions. Augmented reality (AR) technology is recommended to aid educators and students in teaching-learning vectors, namely via a vector personal computer augmented reality system (VPCAR), to fulfil the demand for tools to support the learning and teaching of vectors. Methods: A PC learning module for vectors was developed in a 3-dimensional coordinate system by using AR technology. Purposive sampling was applied to get feedback from educators and students in Malaysia through an online survey. The supportiveness of using VPCAR based on six items (attractiveness, easiness, visualization, conceptual understanding, inspiration and helpfulness) was recorded on 5-points Likert-type scales. Findings are presented descriptively and graphically. Results: Surprisingly, both students and educators adapted to the new technology easily and provided significant positive feedback that showed a left-skewed and J-shaped distribution for each measurement item, respectively. The distributions were proven significantly different among the students and educators, where supportive level result of educators was higher than students. This study introduced a PC learning module other than mobile apps as students mostly use laptops to attend online class and educators also engage other IT tools in their teaching. Conclusions: Based on these findings, VPCAR provides a good prospect in supporting educators and students during their online teaching-learning process. However, the findings may not be generalizable to all students and educators in Malaysia as purposive sampling was applied. Further studies may focus on government-funded schools using the newly developed VPCAR system, which is the novelty of this study.
  9. Ting CY, Gan GG, Bee-Lan Ong D, Tan SY, Bee PC
    Int J Clin Pract, 2020 Oct;74(10):e13594.
    PMID: 32583545 DOI: 10.1111/ijcp.13594
    BACKGROUND: About 20%-30% of diffuse large B-cell lymphoma (DLBCL) patients experience early disease progression despite R-CHOP chemotherapy treatment. Revised international prognostic index (R-IPI) score could risk stratify DLBCL patients but does not identify exactly which patient will be resistant to R-CHOP therapy or experience early relapse.

    AIMS OF THE STUDY: To analyse pre-treatment clinical features of DLBCL patients that are predictive of R-CHOP therapy resistance and early disease relapse after R-CHOP therapy treatment.

    METHODS USED TO CONDUCT THE STUDY: A total of 698 lymphoma patients were screened and 134 R-CHOP-treated DLBCL patients were included. The Lugano 2014 criteria was applied for assessment of treatment response. DLBCL patients were divided into R-CHOP resistance/early relapse group and R-CHOP sensitive/late relapse group.

    RESULTS OF THE STUDY: 81 of 134 (60%) were R-CHOP sensitive/late relapse, while 53 (40%) were R-CHOP resistance/early relapse. The median follow-up period was 59 months ± standard error 3.6. Five-year overall survival rate of R-CHOP resistance/early relapse group was 2.1%, while it was 89% for RCHOP sensitive/late relapse group. Having more than one extranodal site of DLBCL disease is an independent risk factor for R-CHOP resistance/early relapse [odds ratio = 5.268 (1.888-14.702), P = .002]. The commonest extranodal sites were head and neck, gastrointestinal tract, respiratory system, vertebra and bones. Advanced age (>60 years), advanced disease stage (lll-lV), raised pre-treatment lactate dehydrogenase level, bone marrow involvement of DLBCL disease high Eastern Cooperative Oncology Group status (2-4) and high R-IPI score (3-5) showed no significant association with R-CHOP therapy resistance/early disease relapse (multivariate analysis: P > .05).

    CONCLUSION AND CLINICAL IMPLICATIONS: DLBCL patients with more than one extranodal site are 5.268 times more likely to be R-CHOP therapy resistance or experience early disease relapse after R-CHOP therapy. Therefore, correlative studies are warranted in DLBCL patients with more than one extranodal site of disease to explore possible underlying mechanisms of chemoresistance.

  10. Lim LS, Tan SY, Tuzan AD, Kawamura G, Mustafa S, Rahmah S, et al.
    Fish Physiol Biochem, 2020 Aug;46(4):1621-1629.
    PMID: 32430644 DOI: 10.1007/s10695-020-00817-5
    Oxyeleotris marmorata is an ambush predator. It is known for slow growth rate and high market demand. Farming of O. marmorata still remains a challenge. In order to establish a proper feeding practice to stimulate growth, knowledge of its metabolic processes and cost should be examined. Therefore, this study was designed to investigate the diel osmorespiration rhythms of O. marmorata in response to feeding challenge by using an osmorespirometry assay. The results have shown that oxygen consumption rate of the fed fish was approximately 3 times higher than that of the unfed fish in early evening to support specific dynamic action. Digestion and ingestion processes were likely to be completed within 18-20 h in parallel with the ammonia excretion noticeable in early morning. Under resting metabolism, metabolic oxygen consumption was influenced by diel phase, but no effect was noted in ammonia excretion. As a nocturnal species, O. marmorata exhibited standard aerobic metabolic mode under dark phase followed by light phase, with high oxygen consumption rate found in either fed or unfed fish. It can be confirmed that both the diel phase and feeding have a significant interactive impact on oxygen consumption rate, whereas ammonia metabolism is impacted by feeding state. High metabolic rate of O. marmorata supports the nocturnal foraging activity in this fish. This finding suggested that feeding of O. marmorata should be performed during nighttime and water renewal should be conducted during daytime.
  11. Okazaki T, Orii T, Tan SY, Watanabe T, Taguchi A, Rahman FA, et al.
    Anal Chem, 2020 07 21;92(14):9714-9721.
    PMID: 32551577 DOI: 10.1021/acs.analchem.0c01062
    We present an electrochemical long period fiber grating (LPFG) sensor for electroactive species with an optically transparent electrode. The sensor was fabricated by coating indium tin oxide onto the surface of LPFG using a polygonal barrel-sputtering method. LPFG was produced by an electric arc-induced technique. The sensing is based on change in the detection of electron density on the electrode surface during potential application and its reduction by electrochemical redox of analytes. Four typical electroactive species of methylene blue, hexaammineruthenium(III), ferrocyanide, and ferrocenedimethanol were used to investigate the sensor performance. The concentrations of analytes were determined by the modulation of the potential as the change in transmittance around the resonance band of LPFG. The sensitivity of the sensor, particularly to methylene blue, was high, and the sensor responded to a wide concentration range of 0.001 mM to 1 mM.
  12. Tan SY, Leong WH, Ong LH, Mohd-Amin MZ
    Malays Orthop J, 2020 Jul;14(2):138-140.
    PMID: 32983390 DOI: 10.5704/MOJ.2007.023
    Lateral femoral wall perforation is a rare intra-operative complication in anterior cruciate ligament (ACL) reconstruction surgery. However, it can be challenging to manage if it occurs. We share our experience on lateral femoral wall perforation managed by a large fragment washer. A 25-year-old man with right ACL injury presented with knee instability despite physiotherapy. Anterior drawer test (ADT) and Lachman test were grade 3, glide on pivot shift was positive. During ACL reconstruction, the lateral femoral wall was perforated. Due to unavailability of the rescue endobutton and budget constraint, we passed the endobutton through a washer and allowed it to sit on the washer over the lateral femoral wall. ADT and Lachman test on post-operative 6, 12 and 24 weeks were grade 1, with a negative pivot shift test. Lysholm knee score improved from 69 pre-operatively to 98 post-operatively. Conventionally, lateral femoral wall perforation can be managed by rescue endobutton, or screw and washer post technique. As this complication is rare, the rescue endobutton may not be available at all times, and the cost of the implant is also another important factor to consider. A washer can be used as an alternative technique to manage lateral femoral wall perforation in ACL reconstruction as it is not only cost-effective but also provides stable fixation with good functional outcome.
  13. van Zonneveld M, Rakha M, Tan SY, Chou YY, Chang CH, Yen JY, et al.
    Sci Rep, 2020 02 07;10(1):2111.
    PMID: 32034221 DOI: 10.1038/s41598-020-58646-8
    This study provides insights in patterns of distribution of abiotic and biotic stress resilience across Vigna gene pools to enhance the use and conservation of these genetic resources for legume breeding. Vigna is a pantropical genus with more than 88 taxa including important crops such as V. radiata (mung bean) and V. unguiculata (cowpea). Our results show that sources of pest and disease resistance occur in at least 75 percent of the Vigna taxa, which were part of screening assessments, while sources of abiotic stress resilience occur in less than 30 percent of screened taxa. This difference in levels of resilience suggests that Vigna taxa co-evolve with pests and diseases while taxa are more conservative to adapt to climatic changes and salinization. Twenty-two Vigna taxa are poorly conserved in genebanks or not at all. This germplasm is not available for legume breeding and requires urgent germplasm collecting before these taxa extirpate on farm and in the wild. Vigna taxa, which tolerate heat and drought stress are rare compared with taxa, which escape these stresses because of short growing seasons or with taxa, which tolerate salinity. We recommend prioritizing these rare Vigna taxa for conservation and screening for combined abiotic and biotic stress resilience resulting from stacked or multifunctional traits. The high presence of salinity tolerance compared with drought stress tolerance, suggests that Vigna taxa are good at developing salt-tolerant traits. Vigna taxa are therefore of high value for legume production in areas that will suffer from salinization under global climate change.
  14. Lin GW, Xu C, Chen K, Huang HQ, Chen J, Song B, et al.
    Lancet Oncol, 2020 02;21(2):306-316.
    PMID: 31879220 DOI: 10.1016/S1470-2045(19)30799-5
    BACKGROUND: Extranodal natural killer T-cell lymphoma (NKTCL; nasal type) is an aggressive malignancy with a particularly high prevalence in Asian and Latin American populations. Epstein-Barr virus infection has a role in the pathogenesis of NKTCL, and HLA-DPB1 variants are risk factors for the disease. We aimed to identify additional novel genetic variants affecting risk of NKTCL.

    METHODS: We did a genome-wide association study of NKTCL in multiple populations from east Asia. We recruited a discovery cohort of 700 cases with NKTCL and 7752 controls without NKTCL of Han Chinese ancestry from 19 centres in southern, central, and northern regions of China, and four independent replication samples including 717 cases and 12 650 controls. Three of these independent samples (451 cases and 5301 controls) were from eight centres in the same regions of southern, central, and northern China, and the fourth (266 cases and 7349 controls) was from 11 centres in Hong Kong, Taiwan, Singapore, and South Korea. All cases had primary NKTCL that was confirmed histopathologically, and matching with controls was based on geographical region and self-reported ancestry. Logistic regression analysis was done independently by geographical regions, followed by fixed-effect meta-analyses, to identify susceptibility loci. Bioinformatic approaches, including expression quantitative trait loci, binding motif and transcriptome analyses, and biological experiments were done to fine-map and explore the functional relevance of genome-wide association loci to the development of NKTCL.

    FINDINGS: Genetic data were gathered between Jan 1, 2008, and Jan 23, 2019. Meta-analysis of all samples (a total of 1417 cases and 20 402 controls) identified two novel loci significantly associated with NKTCL: IL18RAP on 2q12.1 (rs13015714; p=2·83 × 10-16; odds ratio 1·39 [95% CI 1·28-1·50]) and HLA-DRB1 on 6p21.3 (rs9271588; 9·35 × 10-26 1·53 [1·41-1·65]). Fine-mapping and experimental analyses showed that rs1420106 at the promoter of IL18RAP was highly correlated with rs13015714, and the rs1420106-A risk variant had an upregulatory effect on IL18RAP expression. Cell growth assays in two NKTCL cell lines (YT and SNK-6 cells) showed that knockdown of IL18RAP inhibited cell proliferation by cell cycle arrest in NKTCL cells. Haplotype association analysis showed that haplotype 47F-67I was associated with reduced risk of NKTCL, whereas 47Y-67L was associated with increased risk of NKTCL. These two positions are component parts of the peptide-binding pocket 7 (P7) of the HLA-DR heterodimer, suggesting that these alterations might account for the association at HLA-DRB1, independent of the previously reported HLA-DPB1 variants.

    INTERPRETATION: Our findings provide new insights into the development of NKTCL by showing the importance of inflammation and immune regulation through the IL18-IL18RAP axis and antigen presentation involving HLA-DRB1, which might help to identify potential therapeutic targets. Taken in combination with additional genetic and other risk factors, our results could potentially be used to stratify people at high risk of NKTCL for targeted prevention.

    FUNDING: Guangdong Innovative and Entrepreneurial Research Team Program, National Natural Science Foundation of China, National Program for Support of Top-Notch Young Professionals, Chang Jiang Scholars Program, Singapore Ministry of Health's National Medical Research Council, Tanoto Foundation, National Research Foundation Singapore, Chang Gung Memorial Hospital, Recruitment Program for Young Professionals of China, First Affiliated Hospital and Army Medical University, US National Institutes of Health, and US National Cancer Institute.

  15. Salam DSDA, Thit EE, Teoh SH, Tan SY, Peh SC, Cheah SC
    J Cancer, 2020;11(1):190-198.
    PMID: 31892985 DOI: 10.7150/jca.36954
    C-MYC, BCL2 and BCL6 genes are the most commonly oncogenes involved in B-Cell lymphomas. Translocations of these oncogenes are associated with an aggressive clinical course. This study aims to elucidate the patterns of BCL6, BCL2 and C-MYC gene aberrations among Malaysian B-cell Non-Hodgkin Lymphoma (NHL) using fluorescence in situ hybridization (FISH). Eighty-one B-cell NHL tissue blocks were retrieved between the year 2011 to 2015 and investigated using immunohistochemistry and interphase FISH dual colour break-apart probes of BCL2, BCL6, C-MYC and IgH. A significant difference was detected between the nodal and extranodal sites in all the BCL2 (p=0.01), C-MYC (p=0.03) and IgH (p=0.006) cases except for BCL6 (p=0.2). Our study showed that BCL6 had the highest gene translocation while BCL2/BCL6 had the most mixed aberrations of gain copies and translocation, however no mixed aberrations of gain copies and translocation was found in C-MYC. None of the mixed gain copies and translocation was found in any of the germinal centre B-cell (GCB) subtype of Diffuse Large B-cell Lymphoma, however, five were found in BCL6 and IgH gene in the non-GCB subtype; while mixed gain copies and translocation cases of BCL2 gene was found in the Follicular Lymphoma cases only. The study found interesting findings of BCL2, C-MYC and IgH gene aberrations between nodal and extranodal sites. This information might benefit future study in predicting prognosis and determine effective therapeutic strategies in the multi-ethnic populations of Malaysia as well as the Asian population.
  16. Ting CY, Liew SM, Price A, Gan GG, Bee-Lan Ong D, Tan SY, et al.
    Crit Rev Oncol Hematol, 2019 Dec;144:102818.
    PMID: 31733445 DOI: 10.1016/j.critrevonc.2019.102818
    The clinical significance of aberrantly expressed microRNAs in predicting treatment response to chemotherapy in diffuse large B-cell lymphoma patients (DLBCL) remains uncertain. Feasibility of microRNA testing to predict treatment outcome was evaluated. Twenty-two types of aberrantly expressed microRNAs were associated with poor treatment response; pooled hazard ratio (HR) was 2.14 [95%CI:1.78-2.57, P 
  17. Neik TX, Chai JY, Tan SY, Sudo MPS, Cui Y, Jayaraj J, et al.
    G3 (Bethesda), 2019 09 04;9(9):2941-2950.
    PMID: 31292156 DOI: 10.1534/g3.119.400021
    Weedy crop relatives are among the world's most problematic agricultural weeds, and their ability to rapidly evolve can be enhanced by gene flow from both domesticated crop varieties and wild crop progenitor species. In this study, we examined the role of modern commercial crop cultivars, traditional landraces, and wild relatives in the recent emergence and proliferation of weedy rice in East Malaysia on the island of Borneo. This region of Malaysia is separated from the Asian continent by the South China Sea, and weedy rice has become a major problem there more recently than on the Malaysian peninsular mainland. Using 24 polymorphic SSR loci and genotype data from the awn-length domestication gene An-1, we assessed the genetic diversity, population structure and potential origins of East Malaysian weeds; 564 weedy, cultivated and wild rice accessions were analyzed from samples collected in East Malaysia, Peninsular Malaysia and neighboring countries. While there is considerable evidence for contributions of Peninsular Malaysian weed ecotypes to East Malaysian populations, we find that local crop cultivars and/or landraces from neighboring countries are also likely contributors to the weedy rice infestations. These findings highlight the implications of genetic admixture from different cultivar source populations in the spread of weedy crop relatives and the urgent need for preventive measurements to maintain sustainable crop yields.
  18. Tan SY, Arshad H, Abdullah A
    PLoS One, 2019;14(1):e0207191.
    PMID: 30605474 DOI: 10.1371/journal.pone.0207191
    Mobile Augmented Reality (MAR) requires a descriptor that is robust to changes in viewing conditions in real time application. Many different descriptors had been proposed in the literature for example floating-point descriptors (SIFT and SURF) and binary descriptors (BRIEF, ORB, BRISK and FREAK). According to literature, floating-point descriptors are not suitable for real-time application because its operating speed does not satisfy real-time constraints. Binary descriptors have been developed with compact sizes and lower computation requirements. However, it is unclear which binary descriptors are more appropriate for MAR. Hence, a distinctive and efficient accuracy measurement of four state-of-the-art binary descriptors, namely, BRIEF, ORB, BRISK and FREAK were performed using the Mikolajczyk dataset and ALOI dataset to identify the most appropriate descriptor for MAR in terms of computation time and robustness to brightness, scale and rotation changes. The obtained results showed that FREAK is the most appropriate descriptor for MAR application as it able to produce an application that are efficient (shortest computation time) and robust towards scale, rotation and brightness changes.
  19. Tan SY, Visvanathan S, Abu Hassan R, Khan M
    Front Oncol, 2019;9:1335.
    PMID: 31850220 DOI: 10.3389/fonc.2019.01335
    Hepatitis B virus (HBV) is causally linked to hepatocellular injury and cell death, which are followed by hepatocellular carcinoma (HCC) after a long latent period. The HBV derived X protein (HBX) is the most potent carcinogenic factor for HCC, however, the molecular mechanism of HBX-induced transformation of hepatic cells in HCC is poorly understood. We have shown that nuclear receptor co-repressor (NCoR) is essential for the spatial repression of global transcription by the promyelocytic leukemia oncogenic domains (PODs), a frequent target of viral oncoproteins like HBX and that disintegration of PODs due to misfolded conformation dependent loss (MCDL) of NCoR is linked to promyelocytic and monocytic acute myeloid leukemia (AML). Given the key role of NCoR in cellular homeostasis across various tissue subtypes, we hypothesized that HBX-induced MCDL of NCoR might be linked to HCC through similar mechanism. Based on this hypothesis, the conformation of NCoR in HCC derived tumor cells and primary human tissue sections were analyzed and a selective MCDL of NCoR in HBX positive HCC cells was identified. HBX triggered the misfolding of NCoR through ubiquitination, followed by its degradation by autophagy, thus suggesting a cross talk between ubiquitin proteasome system (UPS) and autophagy lysosomal pathway (ALP) in MCDL of NCoR in HBX positive HCC cells. SiRNA-induced NCoR ablation selectively impaired the growth and survival of HBX positive HCC cells, suggesting a role of MCDL in the growth and survival of HBX positive HCC cells. These finding identify a possible crosstalk between UPS and ALP in the misfolding and loss of NCoR in HBX positive HCC cells and suggest a role of autophagic recycling of misfolded NCoR in the activation of oncogenic metabolic signaling in HCC. The misfolded NCoR reported in this study represents a novel conformation based molecular target which could be valuable in the design and development of tumor cell specific diagnostic and therapeutic approach for HBX positive HCC.
  20. Tan SY, Praveena SM, Abidin EZ, Cheema MS
    Environ Sci Pollut Res Int, 2018 Dec;25(34):34623-34635.
    PMID: 30315534 DOI: 10.1007/s11356-018-3396-x
    This study aimed to determine bioavailable heavy metal concentrations (As, Cd, Co, Cu, Cr, Ni, Pb, Zn) and their potential sources in classroom dust collected from children's hand palms in Rawang (Malaysia). This study also aimed to determine the association between bioavailable heavy metal concentration in classroom dust and children's respiratory symptoms. Health risk assessment (HRA) was applied to evaluate health risks (non-carcinogenic and carcinogenic) due to heavy metals in classroom dust. The mean of bioavailable heavy metal concentrations in classroom dust found on children's hand palms was shown in the following order: Zn (1.25E + 01 μg/g) > Cu (9.59E-01 μg/g) > Ni (5.34E-01 μg/g) > Cr (4.72E-02 μg/g) > Co (2.34E-02 μg/g) > As (1.77E-02 μg/g) > Cd (9.60E-03 μg/g) > Pb (5.00E-03 μg/g). Hierarchical cluster analysis has clustered 17 sampling locations into three clusters, whereby cluster 1 (S3, S4, S6, S15) located in residential areas and near to roads exposed to vehicle emissions, cluster 2 (S10, S12, S9, S7) located near Rawang town and cluster 3 (S13, S16, S1, S2, S8, S14, S11, S17, S5) located near industrial, residential and plantation areas. Emissions from vehicles, plantations and industrial activities were found as the main sources of heavy metals in classroom dust in Rawang. There is no association found between bioavailable heavy metal concentrations and respiratory symptoms, except for Cu (OR = 0.03). Health risks (non-carcinogenic and carcinogenic risks) indicated that there are no potential non-carcinogenic and carcinogenic risks of heavy metals in classroom dust toward children health.
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