Displaying publications 1 - 20 of 60 in total

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  1. Ng, WL, Umi Kalthum MN, Jemaima CH, Norshamsiah MD
    MyJurnal
    Frontal mucocele is not commonly masked as upper lid abscess.A 72-year-old Chinese man with underlying hyperthyroidism complained of left upper eyelid swelling of 6 months duration. The swelling had persisted and worsen when intravenous antibiotic was changed oral type. Visual acuity on presentation was hand motion and reverse relative afferent pupillary defect was present. Because the swelling was large and resulted in mechanical ptosis and ophthalmoplegia, a CT imaging was performed, which showed huge left frontal mucocele eroding the supereromedial orbital rim. The left globe was displaced inferolaterally but there was no extension into brain parenchyma. Fundus examination showed pale optic disc with dull macula. Old laser marks were seen at peripheral fundus. Referral to ortholaryngologist was made and endoscopic sinus surgery and evacuation of mucopyocoele was done. Culture and sensitivity of the fluid showed no organism. He recovered well postoperatively with additional two weeks of antibiotics. We highlight the necessity of surgical drainage of mucocele, following a course of antibiotic.
  2. Ng WL, Abdullah N
    Singapore Med J, 2020 Feb;61(2):81-85.
    PMID: 32152640 DOI: 10.11622/smedj.2020016
    INTRODUCTION: Medical emergencies occur at a rate of one in 604‒753 flights. Doctors travelling on commercial flights may encounter an in-flight medical emergency requiring their assistance. There is a paucity of studies on how confident primary care doctors are in managing in-flight medical emergencies. This study aimed to determine the knowledge, confidence and attitude of primary care doctors in managing in-flight medical emergencies.

    METHODS: A cross-sectional study was conducted on all primary care doctors working in government health clinics in Kuala Lumpur, Malaysia, from October 2016 to November 2016. A self-reported questionnaire was used, which included questions on demographic information, knowledge of in-flight medicine, and the attitude and confidence of primary care doctors in managing in-flight medical emergencies.

    RESULTS: 182 doctors completed the questionnaire (92.9% response rate). The mean knowledge score was 8.9 out of a maximum score of 20. Only 11.5% of doctors felt confident managing in-flight medical emergencies. The majority (69.2%) would assist in an in-flight medical emergency, but the readiness to assist was reduced if someone else was already helping or if they were not familiar with the emergency. Total knowledge score was positively associated with confidence in managing in-flight medical emergencies (p = 0.03).

    CONCLUSION: Only one in ten primary care doctors in this study felt confident managing in-flight medical emergencies. A higher total knowledge score of in-flight medical emergencies was positively associated with greater confidence in managing them. Educational programmes to address this gap in knowledge may be useful to improve doctors' confidence in managing in-flight medical emergencies.

  3. Ng WL, Mohd Mohidin TB, Shukla K
    RNA Biol, 2018;15(8):995-1005.
    PMID: 29954251 DOI: 10.1080/15476286.2018.1486659
    Circular RNAs (circRNAs) are a large class of endogenously expressed non-coding RNAs formed by covalently closed loops through back-splicing. High throughput sequencing technologies have identified thousands of circRNAs with high sequence conservation and cell type specific expression in eukaryotes. CircRNAs play multiple important roles in cellular physiology functioning as miRNA sponges, transcriptional regulators, RBP binding molecules, templates for protein translation, and immune regulators. In a clinical context, circRNAs expression is correlated with patient's clinicopathological features in cancers including breast, liver, gastric, colorectal, and lung cancer. Additionally, distinct properties of circRNAs, such as high stability, exonuclease resistance, and existence in body fluids, show promising role for circRNAs as molecular biomarkers for tumor diagnosis, non-invasive monitoring, prognosis, and therapeutic intervention. Therefore, it is critical to further understand the molecular mechanism underlying circRNAs interaction in tumors and the recent progress of this RNA species in cancer development. In this review, we provide a detailed description of biological functions, molecular role of circRNAs in different cancers, and its potential role as biomarkers in a clinical context.
  4. Ng LS, Khor SY, Ng WL
    Cureus, 2022 Oct;14(10):e30237.
    PMID: 36381844 DOI: 10.7759/cureus.30237
    Hypertriglyceridemic pancreatitis (HTGP) is well-known but it is extremely rare, especially in younger patients. The main treatment modalities for HTGP are apheresis and intravenous insulin. However, apheresis in severe HTGP is not well established and the efficacy of the treatment is lacking. Herein, we discuss a case of a 17-year-old female patient with no significant past medical history who initially presented to the emergency department with severe diabetic ketoacidosis (DKA) and was intubated due to severe metabolic acidosis and impending respiratory failure on arrival. Further investigation showed evidence of HTGP. Initially, her condition did not improve with intravenous insulin. However, a course of apheresis along with supportive care improved her condition drastically. Hence, this is a case report which showed the efficacy of concomitant use of insulin infusion and plasmapheresis in regard to treating HTGP. Outcomes of HTGP based on different treatment modalities are discussed in this literature as well. However, to date, there are no randomized studies to draw a solid treatment algorithm, thus further research on the most efficient treatment regimes is required for the management of HTGP.
  5. Pern YC, Lee SY, Ng WL, Mohamed R
    3 Biotech, 2020 Mar;10(3):103.
    PMID: 32099744 DOI: 10.1007/s13205-020-2072-2
    Tree species in the Aquilarieae tribe of the Thymelaeaceae family produce agarwood, a natural product highly valued for its fragrance, but the species are under threat due to indiscriminate harvesting. For conservation of these species, molecular techniques such as DNA profiling have been used. In this study, we assessed cross-amplification of microsatellite markers, initially developed for three Aquilaria species (A.crassna, A.malaccensis, and A.sinensis), on ten other agarwood-producing species, including members of Aquilaria (A.beccariana, A.hirta, A.microcarpa, A.rostrata, A.rugosa, A.subintegra, and A.yunnanensis) and Gyrinops (G.caudata, G.versteegii, and G.walla), both from the Aquilarieae tribe. Primers for 18 out of the 30 microsatellite markers successfully amplified bands of expected sizes in 1 sample each of at least 10 species. These were further used to genotype 74 individuals representing all the 13 studied species, yielding 13 cross-amplifiable markers, of which only 1 being polymorphic across all species. At each locus, the number of alleles ranged from 7 to 23, indicating a rather high variability. Four markers had relatively high species discrimination power. Our results demonstrated that genetic fingerprinting can be an effective tool in helping to manage agarwood genetic resources by potentially supporting the chain-of-custody of agarwood and its products in the market.
  6. Lee SY, Ng WL, Hishamuddin MS, Mohamed R
    Mitochondrial DNA B Resour, 2019;4(1):19-20.
    PMID: 33365402 DOI: 10.1080/23802359.2018.1535848
    Known for its durable timber quality, Neobalanocarpus heimii (King) Ashton is a highly sought after tree species endemic to the Malay Peninsula. Due to its scarcity and high value, the tree is classified under the IUCN Red List categories of Vulnerable. In this study, we assembled the complete chloroplast (cp) genome of N. heimii using data from high-throughput Illumina sequencing. The Chengal cp genome is 151,191 bp in size and includes two inverted repeat regions of 23,721 bp each, which is separated by a large single copy region of 83,801 bp and a small single copy region of 19,948 bp. A total of 130 genes were predicted, including 37 tRNA, 8 rRNA, and 85 protein-coding genes. Phylogenetic analysis placed N. heimii within the order Malvales.
  7. Lee SY, Ng WL, Mohamed R, Terhem R
    Mitochondrial DNA B Resour, 2018 Oct 29;3(2):1120-1121.
    PMID: 33474439 DOI: 10.1080/23802359.2018.1519382
    Known for its valuable agarwood, Aquilaria malaccensis Lam. is an evergreen tropical forest tree species endemic to the Indo-malesian region. Indiscriminate damaging and harvesting of the trees in the wild have resulted in it being listed in the CITES Appendix II for controlled trade and in the IUCN Red List as 'Vulnerable (VU)'. In this study, the complete chloroplast genome of A. malaccensis was assembled using data from high-throughput Illumina sequencing. The chloroplast genome was 174,832 bp in size, which included two inverted repeat regions of 42,091 bp each, separated by a large single copy region of 87,302 bp and a small single copy region of 3,348 bp. A total of 139 genes were predicted, including 39 tRNA, 8 rRNA, and 92 protein-coding genes. Phylogenetic analysis placed A. malaccensis within the family Thymelaeaceae. The chloroplast genome sequence of A. malaccensis offers a useful resource for future studies on the taxonomy and conservation of the threatened Aquilaria trees.
  8. Pang T, Wong JHD, Ng WL, Chan CS
    Comput Methods Programs Biomed, 2021 May;203:106018.
    PMID: 33714900 DOI: 10.1016/j.cmpb.2021.106018
    BACKGROUND AND OBJECTIVE: The capability of deep learning radiomics (DLR) to extract high-level medical imaging features has promoted the use of computer-aided diagnosis of breast mass detected on ultrasound. Recently, generative adversarial network (GAN) has aided in tackling a general issue in DLR, i.e., obtaining a sufficient number of medical images. However, GAN methods require a pair of input and labeled images, which require an exhaustive human annotation process that is very time-consuming. The aim of this paper is to develop a radiomics model based on a semi-supervised GAN method to perform data augmentation in breast ultrasound images.

    METHODS: A total of 1447 ultrasound images, including 767 benign masses and 680 malignant masses were acquired from a tertiary hospital. A semi-supervised GAN model was developed to augment the breast ultrasound images. The synthesized images were subsequently used to classify breast masses using a convolutional neural network (CNN). The model was validated using a 5-fold cross-validation method.

    RESULTS: The proposed GAN architecture generated high-quality breast ultrasound images, verified by two experienced radiologists. The improved performance of semi-supervised learning increased the quality of the synthetic data produced in comparison to the baseline method. We achieved more accurate breast mass classification results (accuracy 90.41%, sensitivity 87.94%, specificity 85.86%) with our synthetic data augmentation compared to other state-of-the-art methods.

    CONCLUSION: The proposed radiomics model has demonstrated a promising potential to synthesize and classify breast masses on ultrasound in a semi-supervised manner.

  9. Ng WL, Wu W, Zou P, Zhou R
    AoB Plants, 2019 Apr;11(2):plz019.
    PMID: 31037213 DOI: 10.1093/aobpla/plz019
    Variation in gene expression has been shown to promote adaptive divergence, and can lead to speciation. The plant genus Melastoma, thought to have diversified through adaptive radiation, provides an excellent model for the study of gene expressional changes during adaptive differentiation and following interspecific hybridization. In this study, we performed RNA-seq on M. candidum, M. sanguineum and their F1 hybrid, to investigate the role of gene expression in species diversification within the genus. Reference transcriptomes were assembled using combined data from both parental species, resulting in 50 519 and 48 120 transcripts for the leaf and flower petal, after removing redundancy. Differential expression analysis uncovered 3793 and 2116 differentially expressed (DE) transcripts, most of which are between M. candidum and M. sanguineum. Differential expression was observed for genes related to light responses, as well as genes that regulate the development of leaf trichomes, a trait that among others is thought to protect plants against sunlight, suggesting the differential adaptation of the species to sunlight intensity. The analysis of positively selected genes between the two species also revealed possible differential adaptation to other abiotic stresses such as drought and temperature. In the hybrid, almost all possible modes of expression were observed at the DE transcripts, although at most transcripts, the expression levels were similar to that of either parent instead of being intermediate. A small number of transgressively expressed transcripts that matched genes known to promote plant growth and adaptation to stresses in new environments were also found, possibly explaining the vigour observed in the hybrid. The findings in this study provided insights into the role of gene expression in the diversification of Melastoma, which we believe is an important example for more cross-taxa comparisons in the future.
  10. Tan KE, Ng WL, Ea CK, Lim YY
    Bio Protoc, 2023 Sep 05;13(17):e4798.
    PMID: 37849784 DOI: 10.21769/BioProtoc.4798
    Circular RNA (circRNA) is an intriguing class of non-coding RNA that exists as a continuous closed loop. With the improvements in high throughput sequencing, biochemical analysis, and bioinformatic algorithms, studies on circRNA expression became abundant in recent years. However, functional studies of circRNA are still limited. Subcellular localization of circRNA may provide some clues in elucidating its biological functions by performing subcellular fractionation assay. Notably, circRNAs that are predominantly found in the cytoplasm are more likely to be involved in post-transcriptional gene regulation, e.g., acting as micoRNA sponge, whereas nuclear-retained circRNAs are predicted to play a role in transcriptional regulation. Subcellular fractionation could help researchers to narrow down and prioritize downstream experiments. The majority of the currently available protocols describe the steps for subcellular fractionation followed by western blot analysis for protein molecules. Here, we present a protocol for the subcellular fractionation of cells to detect circRNA via RT-qPCR with divergent primers. Moreover, detailed steps for the generation of specific circRNAs-enriched cDNA included in this protocol will enhance the amplification and detection of low-abundance circRNAs. This will be useful for researchers studying low-abundance circRNAs. Key features This protocol builds upon the method developed by Gagnon et al. (2014) and extends its application to circRNA study. Protocol for amplification of low levels of circRNA expression. Analysis takes into consideration the ratio of cytoplasmic RNA concentration to nuclear RNA concentration.
  11. Ho HX, Chong TF, Ng WL, Lee SY
    Data Brief, 2024 Aug;55:110581.
    PMID: 38966661 DOI: 10.1016/j.dib.2024.110581
    Pholas orientalis (angelwing clam) is a mollusc species found in the coastal areas of Southeast Asia. Despite its economic significance, genetic information on the species is lacking. In this study, a P. orientalis specimen was collected from Kedah, Malaysia, and its complete mitochondrial genome was assembled using whole-genome sequencing data generated on an DNBSEQ-G400 platform. The circular mitochondrial genome of P. orientalis is 18,995 bp in size and contains 12 protein-coding genes (PCGs), 22 tRNAs, two rRNAs, and three control regions (D-loops). All genes are located on the heavy strand. The mitogenome has a base composition of 25.4 % A, 41.5 % T, 22.1% G, and 11 % C, exhibiting a bias towards AT content (66.9 %). The mitochondrial genomes of P. orientalis and 11 other Pholadoidea species were included in a phylogenetic analysis, which indicated that P. orientalis is closely related to Xyloredo nooi. The data reported in this study represents the first time that a Pholas mitochondrial genome has been reported. Such data will contribute to the better understanding of genetic relationships between P. orientalis and its relatives, leading to informed conservation and sustainable utilization of the species.
  12. Loh SW, Ng WL, Yeo KS, Lim YY, Ea CK
    PLoS One, 2014;9(7):e103915.
    PMID: 25079219 DOI: 10.1371/journal.pone.0103915
    H3K9 methylation is one of the essential histone post-translational modifications for heterochromatin formation and transcriptional repression. Recently, several studies have demonstrated that H3K9 methylation negatively regulates the type I interferon response.
  13. Chung WH, Ng WL, Chiu CK, Chan C, Kwan MK
    Malays Orthop J, 2020 Nov;14(3):22-31.
    PMID: 33403059 DOI: 10.5704/MOJ.2011.005
    Introduction: This was a retrospective study aimed to investigate the perioperative outcomes of long construct minimally invasive spinal stabilisation (MISt) using percutaneous pedicle screws (PPS) versus conventional open spinal surgery in the treatment of spinal fracture in ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH).

    Material and Methods: Twenty-one patients with AS and DISH who were surgically treated between 2009 and 2017 were recruited. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union rate.

    Results: Mean age was 69.2 ± 9.9 years. Seven patients had AS and 14 patients had DISH. 17 patients sustained AO type B3 fracture and 4 patients had type B1 fracture. Spinal trauma among these patients mostly involved thoracic spine (61.9%), followed by lumbar (28.6%) and cervical spine (9.5%). MISt using PPS was performed in 14 patients (66.7%) whereas open surgery in 7 patients (33.3%). Mean number of instrumentation level was 7.9 ± 1.6. Mean operative time in MISt and open group was 179.3 ± 42.3 minutes and 253.6 ± 98.7 minutes, respectively (p=0.028). Mean intra-operative blood loss in MISt and open group was 185.7 ± 86.4ml and 885.7 ± 338.8ml, respectively (p<0.001). Complications and union rate were comparable between both groups.

    Conclusion: MISt using PPS lowers the operative time and reduces intra-operative blood loss in vertebral fractures in ankylosed disorders. However, it does not reduce the perioperative complication rate due to the premorbid status of the patients. There was no significant difference in the union rate between MISt and open surgery.

  14. Rahmat K, Ab Mumin N, Ramli Hamid MT, Fadzli F, Ng WL, Muhammad Gowdh NF
    Medicine (Baltimore), 2020 Sep 25;99(39):e22405.
    PMID: 32991467 DOI: 10.1097/MD.0000000000022405
    This study aims to compare Quantra, as an automated volumetric breast density (Vbd) tool, with visual assessment according to ACR BI-RADS density categories and to determine its potential usage in clinical practice.Five hundred randomly selected screening and diagnostic mammograms were included in this retrospective study. Three radiologists independently assigned qualitative ACR BI-RADS density categories to the mammograms. Quantra automatically calculates the volumetric density data into the system. The readers were blinded to the Quantra and other readers assessment. Inter-reader agreement and agreement between Quantra and each reader were tested. Region under the curve (ROC) analysis was performed to obtain the cut-off value to separate dense from a non-dense breast. Results with P value
  15. Sze Yong T, Vijayanathan AA, Chung E, Ng WL, Yaakup NA, Sulaiman N
    J Vasc Access, 2021 Jan 13.
    PMID: 33438482 DOI: 10.1177/1129729820987373
    OBJECTIVE: To compare catheter related blood stream infection (CRBSI) rate between cuffed tunnelled and non-cuffed tunnelled PICC.

    METHODS: We prospectively followed 100 patients (50:50 cuffed and non-cuffed PICC) and compared CRBSI rate between these groups. Daily review and similar catheter care were performed until a PICC-related complication, completion of therapy, death or defined end-of-study date necessitate removal. CRBSI was confirmed in each case by demonstrating concordance between isolates colonizing the PICC at the time of infection and from peripheral blood cultures.

    RESULTS: A total of 50 cuffed PICC were placed for 1864 catheter-days. Of these, 12 patients (24%) developed infection, for which 5 patients (10%) had a CRBSI for a rate of 2.7 per 1000 catheter-days. Another 50 tunnelled non-cuffed PICCs were placed for 2057 catheter-days. Of these, 7 patients (14%) developed infection, for which 3 patients (6%) had a CRBSI. for a rate of 1.5 per 1000 catheter-days. The mean time to development of infection is 24 days in cuffed and 19 days in non-cuffed groups. The mean duration of utilization was significantly longer in non-cuffed than in cuffed group (43 days in non-cuffed vs 37 days in cuffed group, p = 0.008).

    CONCLUSIONS: Cuffed PICC does not further reduce the rate of local or bloodstream infection. Tunnelled non-cuffed PICC is shown to be as effective if not better at reducing risk of CRBSI and providing longer catheter dwell time compared to cuffed PICC.

  16. Guo W, Banerjee AK, Wu H, Ng WL, Feng H, Qiao S, et al.
    Front Plant Sci, 2021;12:637009.
    PMID: 34249031 DOI: 10.3389/fpls.2021.637009
    Mangroves are ecologically important forest communities in tropical and subtropical coasts, the effective management of which requires understanding of their phylogeographic patterns. However, these patterns often vary among different species, even among ecologically similar taxa or congeneric species. Here, we investigated the levels and patterns of genetic variation within Lumnitzera consisting of two species (L. racemosa and L. littorea) with nearly sympatric ranges across the Indo-West Pacific (IWP) region by sequencing three chloroplast DNA regions (for both species) and genotyping 11 nuclear microsatellite loci (for L. littorea). Consistent with findings in studies on other mangrove species, we found that both L. racemosa and L. littorea showed relatively high genetic variation among populations but low genetic variation within populations. Haplotype network and genetic clustering analyses indicated two well-differentiated clades in both L. racemosa and L. littorea. The relationship between geographic and genetic distances and divergence time estimates of the haplotypes indicated that limited dispersal ability of the propagules, emergence of land barriers during ancient sea-level changes, and contemporary oceanic circulation pattern in the IWP influenced the current population structure of the two species. However, the position of genetic break was found to vary between the two species: in L. racemosa, strong divergence was observed between populations from the Indian Ocean and the Pacific Ocean possibly due to land barrier effect of the Malay Peninsula; in L. littorea, the phylogeographic pattern was created by a more eastward genetic break along the biogeographic barrier identified as the Huxley's line. Overall, our findings strongly supported previous hypothesis of mangrove species divergence and revealed that the two Lumnitzera species have different phylogeographic patterns despite their close genetic relationship and similar current geographic distribution. The findings also provided references for the management of Lumnitzera mangroves, especially for the threatened L. littorea.
  17. Ng WL, Marinov GK, Liau ES, Lam YL, Lim YY, Ea CK
    RNA Biol, 2016 09;13(9):861-71.
    PMID: 27362560 DOI: 10.1080/15476286.2016.1207036
    Circular RNAs (circRNAs) constitute a large class of RNA species formed by the back-splicing of co-linear exons, often within protein-coding transcripts. Despite much progress in the field, it remains elusive whether the majority of circRNAs are merely aberrant splicing by-products with unknown functions, or their production is spatially and temporally regulated to carry out specific biological functions. To date, the majority of circRNAs have been cataloged in resting cells. Here, we identify an LPS-inducible circRNA: mcircRasGEF1B, which is predominantly localized in cytoplasm, shows cell-type specific expression, and has a human homolog with similar properties, hcircRasGEF1B. We show that knockdown of the expression of mcircRasGEF1B reduces LPS-induced ICAM-1 expression. Additionally, we demonstrate that mcircRasGEF1B regulates the stability of mature ICAM-1 mRNAs. These findings expand the inventory of functionally characterized circRNAs with a novel RNA species that may play a critical role in fine-tuning immune responses and protecting cells against microbial infection.
  18. Chang W, Ee-Uli J, Ng WL, Rovie-Ryan JJ, Tan SG, Yong CSY
    Sci Rep, 2019 06 11;9(1):8504.
    PMID: 31186469 DOI: 10.1038/s41598-019-44870-4
    Macaca fascicularis, also known as the cynomolgus macaque, is an important non-human primate animal model used in biomedical research. It is an Old-World primate widely distributed in Southeast Asia and is one of the most abundant macaque species in Malaysia. However, the genetic structure of wild cynomolgus macaque populations in Malaysia has not been thoroughly elucidated. In this study, we developed genic-simple sequence repeat (genic-SSR) markers from an in-house transcriptome dataset generated from the Malaysian cynomolgus macaque via RNA sequencing, and applied these markers on 26 cynomolgus macaque individuals. A collection of 14,751 genic-SSRs were identified, where 13,709 were perfect SSRs. Dinucleotide repeats were the most common repeat motifs with a frequency of 65.05%, followed by trinucleotide repeats (20.55%). Subsequently, we designed 300 pairs of primers based on perfect di- and trinucleotide SSRs, in which 105 SSRs were associated with functional genes. A subset of 30 SSR markers were randomly selected and validated, yielding 19 polymorphic markers with an average polymorphism information content value of 0.431. The development of genic-SSR markers in this study is indeed timely to provide useful markers for functional and population genetic studies of the cynomolgus macaque and other related non-human primate species.
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