Displaying all 14 publications

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  1. Ng CK, Tan J
    J Fish Biol, 2021 Oct;99(4):1256-1273.
    PMID: 34159593 DOI: 10.1111/jfb.14829
    Morphology-based taxonomy of freshwater fish is effective when there are representative specimens covering large regions. However, in Sundaland, where the presence of cryptic species is high, the technique has its limitations. This is compounded by uncritical descriptions of holotypes in old literature. We demonstrate the problem using Barbodes binotatus first described from an ink drawing. Several species in the Barbodes genus of Sundaland exhibit morphological similarity to B. binotatus. We applied new DNA sequences of 16S, cytochrome c oxidase subunit I (COI), cytochrome b (Cytb) and recombination-activating gene 1 (RAG1), and pigmentation markers to clarify species complex boundaries in the Malay Peninsula, namely B. aff. binotatus "Malay Peninsula", Barbodes cf. banksi and Barbodes rhombeus. Results suggest B. binotatus-like specimens in the Malay Peninsula are B. rhombeus based on a threshold of 3% COI genetic divergence. B. aff. binotatus recorded in Sumatra, Borneo and the Philippines are likely valid but undescribed species. However, if the 2% COI threshold is applied, some populations in the northern Malay Peninsula would qualify as new and undescribed species. The implications of the 2% threshold and the likelihood of "grey zone" incipient populations are discussed. We further found a rapid visual method, not reported previously, to delineate B. aff. binotatus and B. cf. banksi, but it requires further validation. Additionally, we offer fresh perspectives by discussing the roles of biological species concept, morphological species concept, genetic species concept and mate recognition concept in the B. binotatus complex. Our findings reinforce the standpoint that species delineation is not entirely a binary process, but there is a spectrum to consider, especially in biogeography intersection regions.
  2. Ng CK, Azuhairy A, Tan LH, Nordin A
    Malays Orthop J, 2015 Jul;9(2):51-53.
    PMID: 28435611 MyJurnal DOI: 10.5704/MOJ.1507.001
    Chondrosarcoma is the third most common primary tumour of the bone, after myeloma and osteosarcoma. Most of the chondrosarcoma grow slowly and rarely metastasize, and they have an excellent prognosis after adequate surgery. However most of them are chemo or radio-resistant. We report a case of primary chondrosarcoma of proximal humerus in a 36-year-old female who presented with a six years history of left shoulder swelling and restricted range of motion. Trucut biopsy showed a well-differentiated chondrosarcoma. The patient underwent forequarter amputation of left upper limb and was started on chemotherapy following operation.
  3. Ng CK, Payne J, Oram F
    Ambio, 2021 Mar;50(3):601-614.
    PMID: 32915445 DOI: 10.1007/s13280-020-01384-y
    We present herein our perspective of a novel Small Habitats Matrix (SHM) concept showing how small habitats on private lands are untapped but can be valuable for mitigating ecological degradation. Grounded by the realities in Sabah, Malaysian Borneo, we model a discontinuous "stepping stones" linkage that includes both terrestrial and aquatic habitats to illustrate exactly how the SHM can be deployed. Taken together, the SHM is expected to optimize the meta-population vitality in monoculture landscapes for aerial, arboreal, terrestrial and aquatic wildlife communities. We also provide the tangible cost estimates and discuss how such a concept is both economically affordable and plausible to complement global conservation initiatives. By proposing a practical approach to conservation in the rapidly developing tropics, we present a perspective from "ground zero" that reaches out to fellow scientists, funders, activists and pro-environmental land owners who often ask, "What more can we do?"
  4. Eshkoor SA, Hamid TA, Mun CY, Ng CK
    Clin Interv Aging, 2015;10:687-93.
    PMID: 25914527 DOI: 10.2147/CIA.S73922
    Mild cognitive impairment (MCI) is a common condition in the elderly. It is characterized by deterioration of memory, attention, and cognitive function that is beyond what is expected based on age and educational level. MCI does not interfere significantly with individuals' daily activities. It can act as a transitional level of evolving dementia with a range of conversion of 10%-15% per year. Thus, it is crucial to protect older people against MCI and developing dementia. The preventive interventions and appropriate treatments should improve cognitive performance, and retard or prevent progressive deficits. The avoidance of toxins, reduction of stress, prevention of somatic diseases, implementation of mental and physical exercises, as well as the use of dietary compounds like antioxidants and supplements can be protective against MCI. The modification of risk factors such as stopping smoking, as well as the treatment of deficiency in vitamins and hormones by correcting behaviors and lifestyle, can prevent cognitive decline in the elderly. The progressive increase in the growth rate of the elderly population can enhance the rate of MCI all over the world. There is no exact cure for MCI and dementia; therefore, further studies are needed in the future to determine causes of MCI and risk factors of progression from MCI to dementia. This will help to find better ways for prevention and treatment of cognitive impairment worldwide.
  5. Ng CK, How KY, Tee KK, Chan KG
    Genes (Basel), 2019 04 08;10(4).
    PMID: 30965610 DOI: 10.3390/genes10040282
    Quorum sensing (QS) is a cell-to-cell communication system that uses autoinducers as signaling molecules to enable inter-species and intra-species interactions in response to external stimuli according to the population density. QS allows bacteria such as Acinetobacter baumannii to react rapidly in response to environmental changes and hence, increase the chances of survival. A. baumannii is one of the causative agents in hospital-acquired infections and the number of cases has increased remarkably in the past decade. In this study, A. baumannii strain 863, a multidrug-resistant pathogen, was found to exhibit QS activity by producing N-acyl homoserine lactone. We identified the autoinducer synthase gene, which we named abaI, by performing whole genome sequencing analysis of A. baumannii strain 863. Using high resolution tandem triple quadrupole mass spectrometry, we reported that abaI of A. baumannii strain 863 produced 3-hydroxy-dodecanoyl-homoserine lactone. A gene deletion mutant was constructed, which confirmed the functionality of abaI. A growth defect was observed in the QS-deficient mutant strain. Transcriptome profiling was performed to determine the possible genes regulated by QS. Four groups of genes that showed differential expression were discovered, namely those involved in carbon source metabolism, energy production, stress response and the translation process.
  6. Ng CK, Ooi PA, Wong WL, Khoo G
    J Environ Manage, 2020 Feb 01;255:109829.
    PMID: 31783208 DOI: 10.1016/j.jenvman.2019.109829
    Anthropogenic pressures are causing substantial degradation to the freshwater ecosystems globally and Malaysia has not escaped such a bleak scenario. Prompted by the predicament, this study's objective was to pioneer a river assessment system that can be readily adopted to monitor, manage and drive improvement in a wholesome manner. Three sets of a priori metrics were selected to form the Ichthyofaunal Quality Index (IQI: biological), Water Quality Index (WQI: chemical) and River Physical Quality Index (RPQI: physical). These indices were further integrated on equal weighting to construct a novel Malaysian River Integrity Index (MyRII). To test its robustness, the MyRII protocol was field tested in four eco-hydrological zones located in the Kampar River water basin for 18 months to reveal its strengths, weaknesses, and establish the "excellent", "good", "average", "poor" and "impaired" thresholds based on the "best performer" reference site in an empirical manner. The resultant MyRII showed a clear trend that corresponded with different levels of river impairment. Test site zone A which was a reference site with minimal disturbance achieved the highest MyRII (88.95 ± 4.29), followed by partially disturbed zone B (61.95 ± 5.90) and heavily disturbed zone C (50.00 ± 4.29). However, the MyRII in zone D (59.9 ± 6.39), which was a heavily disturbed wetland that was disjointed from the river, did not conform to such trend. Also unveiled and recognized, however, are some unexpected nuances, limitations and challenges that emerged from this study. These are critically discussed as precautions when interpreting and implementing the MyRII protocol. This study adds to the mounting body of evidence that water resource stakeholders and policymakers must look at the big picture and adopt the "balanced ecosystem" mind-set when assessing, restoring and managing the rivers as a freshwater resource.
  7. Ng CK, Kong RW, Foo GH, Khoo G
    Environ Monit Assess, 2022 Dec 24;195(1):228.
    PMID: 36565392 DOI: 10.1007/s10661-022-10789-z
    The agriculture sector responsible for global food and nutrition security has an urgent need to examine climatic trends so that adaptations can be exercised in advance. Freely available dataset from satellite sources can greatly ease rainfall analysis, especially for smallholder farmers who typically operate under limited resources. Tests to determine their accuracy, however, are so far not deployed in tropical Southeast Asia. We compared in situ observations with dataset from the Global Satellite Mapping of Precipitation (GSMaP) and the Prediction of Worldwide Energy Resources (POWER) in two sites located 180 km apart in the tropical Malay Peninsula for 30 days. We found that in situ precipitation values were markedly overestimated by GSMaP (34.9-67.5%) and POWER (180.5-289.2%), and the possible reasons are discussed. Nonetheless, we conclude that GSMaP remains the best hope for smallholder farmers and its dataset can still be used under the precaution of error margins determined by the practical method described herein.
  8. Lee M, Ho JPY, Chen JY, Ng CK, Yeo SJ, Merican AM
    J Knee Surg, 2022 Feb;35(3):280-287.
    PMID: 32629512 DOI: 10.1055/s-0040-1713733
    BACKGROUND:  Restoration of the anatomical joint line, while important for clinical outcomes, is difficult to achieve in revision total knee arthroplasty (rTKA) due to distal femoral bone loss. The objective of this study was to determine a reliable method of restoring the anatomical joint line and posterior condylar offset in the setting of rTKA based on three-dimensional (3D) reconstruction of computed tomography (CT) images of the distal femur.

    METHODS:  CT scans of 50 lower limbs were analyzed. Key anatomical landmarks such as the medial epicondyle (ME), lateral epicondyle, and transepicondylar width (TEW) were determined on 3D models constructed from the CT images. Best-fit planes placed on the most distal and posterior loci of points on the femoral condyles were used to define the distal and posterior joint lines, respectively. Statistical analysis was performed to determine the relationships between the anatomical landmarks and the distal and posterior joint lines.

    RESULTS:  There was a strong correlation between the distance from the ME to the distal joint line of the medial condyle (MEDC) and the distance from the ME to the posterior joint line of the medial condyle (MEPC) (p 

  9. Ng CK, Chen JY, Yeh JZY, Ho JPY, Merican AM, Yeo SJ
    J Arthroplasty, 2018 06;33(6):1936-1944.
    PMID: 29395720 DOI: 10.1016/j.arth.2017.12.025
    BACKGROUND: We hypothesized that there is a correlation between the distal femoral rotation and proximal tibial joint line obliquity in nonarthritic knees. This has significance for kinematic knee arthroplasty, in which the target knee alignment desired approximates the knee before disease.

    METHODS: Fifty computed tomography scans of nonarthritic knees were evaluated using three-dimensional image processing software. Four distal femoral rotational axes were determined in the axial plane: the transepicondylar axis (TEA), transcondylar axis (TCA), posterior condylar axis (PCA), and a line perpendicular to Whiteside's anterior-posterior axis. Then, angles were measured relative to the TEA. Tibial joint line obliquity was measured as the angle between the proximal tibial plane and a line perpendicular to the axis of the tibia.

    RESULTS: There was a strong positive correlation between PCA-TEA and tibial joint line obliquity (r = 0.68, P < .001) as well as TCA-TEA and tibial joint line obliquity (r = 0.69, P < .001). In addition, the tibial joint line obliquity and TCA-TEA angles were similar, 3.7° ± 2.2° (mean ± standard deviation) and 3.5° ± 1.7°, respectively (mean difference, 0.2° ± 0.2°; P = .369).

    CONCLUSION: Both PCA-TEA and TCA-TEA strongly correlated with proximal tibial joint line obliquity indicating a relationship between distal femoral rotational geometry and proximal tibial inclination. These findings could imply that the native knee in flexion attempts to balance the collateral ligaments toward a rectangular flexion space. A higher tibial varus inclination is matched with a more internally rotated distal femur relative to the TEA.

  10. Chong PP, Asyikin N, Rusinahayati M, Halimatun S, Rozita R, Ng CK, et al.
    Asian Pac J Cancer Prev, 2010;11(6):1645-51.
    PMID: 21338211
    Persistent high-risk human papillomavirus (HPV) infection is known to play an important role in the genesis of cervical cancer. Since new screening and prevention strategies, namely improved HPV testing and HPV vaccination have been aggressively promoted recently, it is crucial to investigate the HPV distribution in Malaysia in order to maximize their cost-effectiveness. This study was therefore conducted to assess the HPV type distribution in the most populous region, the state of Selangor. A total of 200 cervical swab samples were collected in two health-screening campaigns, and also from women attending obstetrics and gynecology clinics in several hospitals in Selangor. DNA extraction was performed and HPV DNA was detected via nested PCR using MY09/MY11 as outer primers and GP5+/GP6+ as inner primers which target the L1 gene of the viral genome. The purified PCR products were subjected to automated DNA sequencing to determine the HPV genotype. Out of 180 β-globin positive samples, 84 (46.7%) were positive for HPV DNA. The most common HPV type found was high-risk oncogenic type 16 (40%), followed by HPV type 18 (3.3%), HPV 33 (1.7%), HPV 31 (0.6%), and low-risk HPV 87 (0.6%). Our study confirmed that nested PCR method is highly sensitive in detecting HPV DNA even in low risk patients. Since a relatively high prevalence rate of HPV infection was found in this population, prompt healthcare policy changes to bring about implementation of early HPV vaccination program is desirable to prevent a high incidence of cervical cancer.

    Study site: Gynaecology and Obstetrics Clinics in Selangor (Hospital Kajang, Hospital Serdang, and the Britannia Women and Children Specialist Centre)
  11. Ng CK, Goh CH, Lin JC, Tan MS, Bong W, Yong CS, et al.
    Environ Monit Assess, 2018 Jun 15;190(7):402.
    PMID: 29904816 DOI: 10.1007/s10661-018-6784-2
    El Niño and Southern Oscillation (ENSO) is a natural forcing that affects global climate patterns, thereon influencing freshwater quality and security. In the advent of a strong El Niño warming event in 2016 which induced an extreme dry weather in Malaysia, water quality variation was investigated in Kampar River which supplies potable water to a population of 92,850. Sampling points were stratified into four ecohydrological units and 144 water samples were examined from October 2015 to March 2017. The Malaysian Water Quality Index (WQI) and some supplementary parameters were analysed in the context of reduced precipitation. Data shows that prolonged dry weather, episodic and sporadic pollution incidents have caused some anomalies in dissolved oxygen (DO), total suspended solids (TSS), turbidity and ammoniacal nitrogen (AN) values recorded and the possible factors are discussed. The month of March and August 2016 recorded the lowest precipitation, but the overall resultant WQI remained acceptable. Since the occurrence of a strong El Niño event is infrequent and far between in decadal time scale, this paper gives some rare insights that may be central to monitoring and managing freshwater resource that has a crucial impact to the mass population in the region of Southeast Asia.
  12. Tan AH, Lim SY, Mahadeva S, Loke MF, Tan JY, Ang BH, et al.
    Mov Disord, 2020 12;35(12):2250-2260.
    PMID: 32894625 DOI: 10.1002/mds.28248
    BACKGROUND: Helicobacter pylori (HP) infection has been associated with worse motor function in Parkinson's disease (PD).

    OBJECTIVE: We aimed to evaluate the effects of HP eradication on PD symptoms.

    METHODS: In this parallel-group, double-blind, randomized placebo-controlled, single-center trial, patients with PD with positive HP urea breath test and serology were block randomized (1:1) to receive standard eradication triple therapy or identically appearing placebo capsules for 1 week. Prespecified motor (International Parkinson and Movement Disorder Society Unified PD Rating Scale [MDS-UPDRS], timed tests, and home-based wearable sensor measurements), nonmotor (Leeds Dyspepsia Questionnaire and Montreal Cognitive Assessment), and quality-of-life (Parkinson's Disease Questionnaire-39) outcome measures were assessed at weeks 6, 12, 24, and 52. The primary outcome was the baseline-to-week 12 change in ON medication MDS-UPDRS motor scores. Lactulose-hydrogen breath testing for concomitant small intestinal bacterial overgrowth was performed at baseline and repeated at week 24, together with the urea breath test.

    RESULTS: A total of 310 patients were screened for eligibility and 80 were randomly assigned, of whom 67 were included in the full-analysis set (32 treatment group patients, 35 placebo patients). HP eradication did not improve MDS-UPDRS motor scores at week 12 (mean difference 2.6 points in favor of placebo, 95% confidence interval: -0.4 to 5.6, P = 0.089). There was no significant improvement in any motor, nonmotor, or quality-of-life outcome at weeks 12 and 52. Both the full-analysis and per-protocol analyses (based on eradication status) supported these conclusions. Small intestinal bacterial overgrowth status did not influence treatment results.

    CONCLUSIONS: HP eradication does not improve clinical outcomes in PD, suggesting that there is no justification for routine HP screening or eradication with the goal of improving PD symptoms. © 2020 International Parkinson and Movement Disorder Society.

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