Displaying publications 1 - 20 of 87 in total

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  1. Ng CH, Nur-Aishah T
    Malays Fam Physician, 2009;4(2-3):66-70.
    PMID: 25606166 MyJurnal
    Breast cancer is becoming more important in Asia since it affect the younger age group. Question arises whether it is safe for breast lesions to be left in-situ if all the elements in triple assessment are benign. The aim of this study is to audit all the excision biopsies of breast lumps done in the University Malaya Medical Centre (UMMC), to review the association of age with the type of pathological finding and to evaluate the rate of carcinoma in these biopsies.
  2. Tey HJ, Ng CH
    PeerJ, 2019;7:e7667.
    PMID: 31592138 DOI: 10.7717/peerj.7667
    Background: From genome wide association studies on Alzheimer's disease (AD), it has been shown that many single nucleotide polymorphisms (SNPs) of genes of different pathways affect the disease risk. One of the pathways is endocytosis, and variants in these genes may affect their functions in amyloid precursor protein (APP) trafficking, amyloid-beta (Aβ) production as well as its clearance in the brain. This study uses computational methods to predict the effect of novel SNPs, including untranslated region (UTR) variants, splice site variants, synonymous SNPs (sSNPs) and non-synonymous SNPs (nsSNPs) in three endocytosis genes associated with AD, namely PICALM, SYNJ1 and SH3KBP1.

    Materials and Methods: All the variants' information was retrieved from the Ensembl genome database, and then different variation prediction analyses were performed. UTRScan was used to predict UTR variants while MaxEntScan was used to predict splice site variants. Meta-analysis by PredictSNP2 was used to predict sSNPs. Parallel prediction analyses by five different software packages including SIFT, PolyPhen-2, Mutation Assessor, I-Mutant2.0 and SNPs&GO were used to predict the effects of nsSNPs. The level of evolutionary conservation of deleterious nsSNPs was further analyzed using ConSurf server. Mutant protein structures of deleterious nsSNPs were modelled and refined using SPARKS-X and ModRefiner for structural comparison.

    Results: A total of 56 deleterious variants were identified in this study, including 12 UTR variants, 18 splice site variants, eight sSNPs and 18 nsSNPs. Among these 56 deleterious variants, seven variants were also identified in the Alzheimer's Disease Sequencing Project (ADSP), Alzheimer's Disease Neuroimaging Initiative (ADNI) and Mount Sinai Brain Bank (MSBB) studies.

    Discussion: The 56 deleterious variants were predicted to affect the regulation of gene expression, or have functional impacts on these three endocytosis genes and their gene products. The deleterious variants in these genes are expected to affect their cellular function in endocytosis and may be implicated in the pathogenesis of AD as well. The biological consequences of these deleterious variants and their potential impacts on the disease risks could be further validated experimentally and may be useful for gene-disease association study.

  3. Shafie AA, Ng CH
    Clinicoecon Outcomes Res, 2020;12:333-343.
    PMID: 32606850 DOI: 10.2147/CEOR.S244884
    Objective: To compare the cost-effectiveness of long-acting insulin analogue (LAIA) (insulin Detemir and insulin Glargine) versus NPH insulin in the basal insulin regime for naïve insulin T2DM Malaysian patients.

    Methods: The UKPDS-Outcome Model version 2.0 (UKPDS-OM2) was used to evaluate the cost and consequence of diabetes-related complication. The effectiveness of the insulin was derived from the literature review, and the patients' epidemiology characteristics were retrieved from the Malaysian Diabetes Registry. A discount rate of 3% was applied to both costs and health effects. Another simple mathematical model was used to compare the benefit of reducing the hypoglycemia events between LAIA and NPH insulin. The outputs of the models were combined to obtain the final result. One-way sensitivity analyses were performed to assess the uncertainties.

    Results: The net cost difference (without accounting for hypoglycemia) was RM4868 for insulin Glargine and RM6026 for insulin Detemir. The saving from preventing severe hypoglycemia was RM4377 for insulin Glargine and RM12,753 for insulin Detemir. The total additional QALY gained from insulin Glargine was 0.1317 and from insulin Detemir was 0.8376. The sensitivity analysis shows the discount rate, and drug acquisition cost may affect the incremental cost-effectiveness ratio (ICER) value.

    Conclusion: Both insulin Detemir and Glargine are cost-effective compared to NPH insulin for T2DM patients, especially when the benefit of reducing the hypoglycemia event rate is taken into account.

  4. Chikira M, Ng CH, Palaniandavar M
    Int J Mol Sci, 2015;16(9):22754-80.
    PMID: 26402668 DOI: 10.3390/ijms160922754
    The interaction of simple and ternary Cu(II) complexes of 1,10-phenanthrolines with DNA has been studied extensively because of their various interesting and important functions such as DNA cleavage activity, cytotoxicity towards cancer cells, and DNA based asymmetric catalysis. Such functions are closely related to the DNA binding modes of the complexes such as intercalation, groove binding, and electrostatic surface binding. A variety of spectroscopic methods have been used to study the DNA binding mode of the Cu(II) complexes. Of all these methods, DNA-fiber electron paramagnetic resonance (EPR) spectroscopy affords unique information on the DNA binding structures of the complexes. In this review we summarize the results of our DNA-fiber EPR studies on the DNA binding structure of the complexes and discuss them together with the data accumulated by using other measurements.
  5. Tibon NS, Ng CH, Cheong SL
    Eur J Med Chem, 2020 Feb 15;188:111983.
    PMID: 31911292 DOI: 10.1016/j.ejmech.2019.111983
    Discovery and development of antimalarial drugs have long been dominated by single-target therapy. Continuous effort has been made to explore and identify different targets in malaria parasite crucial for the malaria treatment. The single-target drug therapy was initially successful, but it was later supplanted by combination therapy with multiple drugs to overcome drug resistance. Emergence of resistant strains even against the combination therapy has warranted a review of current antimalarial pharmacotherapy. This has led to the development of the new concept of covalent biotherapy, in which two or more pharmacophores are chemically bound to produce hybrid antimalarial drugs with multi-target functionalities. Herein, the review initially details the current pharmacotherapy for malaria as well as the conventional and novel targets of importance identified in the malaria parasite. Then, the rationale of multi-targeted therapy for malaria, approaches taken to develop the multi-target antimalarial hybrids, and the examples of hybrid molecules are comprehensively enumerated and discussed.
  6. Shafie AA, Tan YP, Ng CH
    Heart Fail Rev, 2018 01;23(1):131-145.
    PMID: 29124528 DOI: 10.1007/s10741-017-9661-0
    The aim of this study is to perform a systematic review of the costing methodological approaches adopted by published cost-of-illness (COI) studies. A systematic review was performed to identify cost-of-illness studies of heart failure published between January 2003 and September 2015 via computerized databases such as Pubmed, Wiley Online, Science Direct, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). Costs reported in the original studies were converted to 2014 international dollars (Int$). Thirty five out of 4972 studies met the inclusion criteria. Nineteen out of the 35 studies reported the costs as annual cost per patient, ranging from Int$ 908.00 to Int$ 84,434.00, while nine studies reported costs as per hospitalization, ranging from Int$ 3780.00 to Int$ 34,233.00. Cost of heart failure increased as condition of heart failure worsened from New York Heart Association (NYHA) class I to NYHA class IV. Hospitalization cost was found to be the main cost driver to the total health care cost. The annual cost of heart failure ranges from Int$ 908 to Int$ 40,971 per patient. The reported cost estimates were inconsistent across the COI studies, mainly due to the variation in term of methodological approaches such as disease definition, epidemiological approach of study, study perspective, cost disaggregation, estimation of resource utilization, valuation of unit cost components, and data sources used. Such variation will affect the reliability, consistency, validity, and relevance of the cost estimates across studies.
  7. Thew HZ, Ng CH, Loo CY
    BMJ Case Rep, 2024 Feb 17;17(2).
    PMID: 38367998 DOI: 10.1136/bcr-2023-258526
    This is the case of a gravida 3 para 1 woman in her late 20s with underlying haemoglobin constant spring who visited a healthcare clinic for an antenatal check-up. Towards the end of her second trimester, she experienced lethargy. During her antenatal booking, she was diagnosed with mild asymptomatic anaemia, high serum ferritin, T saturation of 88% and abnormal liver function tests. She was referred to a hospital where an MRI scan revealed over 2 g of iron deposits in her liver, leading to a revised diagnosis of iron overload. Treatment included deferoxamine and expectant management throughout her antenatal period, and her delivery was uncomplicated. While iron deficiency anaemia is common in pregnancy, it is crucial not to overlook iron deposition and the distinction from acute fatty liver during pregnancy to prevent treatment delays.
  8. Quek KF, Sallam AA, Ng CH, Chua CB
    J Sex Med, 2008 Jan;5(1):70-6.
    PMID: 17362280 DOI: 10.1111/j.1743-6109.2006.00423.x
    INTRODUCTION: Sexual problems are common in the general population. Studies have shown that most of these sexual problems are related to their social lives, medical illnesses, and psychological status. Among the sexual problems in men, premature ejaculation (PE) is one of the most frequent, yet it is the least well-understood of the sexual dysfunctions of men.
    AIM: To determine the prevalence of sexual problem particularly PE and erectile dysfunction (ED) among people living in urban areas and to investigate the characteristics associated with these sexual problems in a Malaysian population.
    MAIN OUTCOME MEASURE: The PE which is defined as an intravaginal ejaculation latency time less than 2 minutes was assessed in the ED and non-ED group.
    METHODS: The Hospital Anxiety and Depression scale is used as a measure of the psychological status [30]. The ED status was assessed using the International Index of Erectile Function questionnaire.
    RESULTS: The prevalence of self-reported sexual problems for ED and PE were 41.6% and 22.3%, respectively. In those subjects with ED, 33.5% reported to have PE. Of the total of 430 subjects, anxiety was present in 8.1%, while depression was 5.3%. The prevalence of PE accounted for 25% anxiety and 14.6% for depression respectively in the population. EDs were associated with diabetes and hypertension (OR [95% CI]: 5.33 [2.33, 10.16], 3.40 [1.76, 6.57], P < 0.05), respectively, while factors associated with PE were anxiety and depression (OR [95% CI]: 1.29 [0.68, 2.45], 1.39 [0.69, 2.78]), respectively.
    CONCLUSION: Prevalence of ED is associated with medical symptoms such as diabetes and hypertension and a rise in the prevalence of age while psychological distress such as anxiety and depression also contribute to a higher PE rate.
  9. Tiong V, Rozita AM, Taib NA, Yip CH, Ng CH
    World J Surg, 2014 Sep;38(9):2288-96.
    PMID: 24700093 DOI: 10.1007/s00268-014-2542-y
    Breast cancer is increasingly reported in young premenopausal women in Asia. Adjuvant chemotherapy improves survival; however, it has a unique consequence of ovarian failure in premenopausal patients.
  10. Watanabe H, Ng CH, Limviphuvadh V, Suzuki S, Yamada T
    PeerJ, 2020;8:e9579.
    PMID: 32821539 DOI: 10.7717/peerj.9579
    Coffee beans derived from feces of the civet cat are used to brew coffee known as kopi luwak (the Indonesian words for coffee and palm civet, respectively), which is one of the most expensive coffees in the world owing to its limited supply and strong market demand. Recent metabolomics studies have revealed that kopi luwak metabolites differ from metabolites found in other coffee beans. To produce kopi luwak, coffee beans are first eaten by civet cats. It has been proposed that fermentation inside the civet cat digestive tract may contribute to the distinctively smooth flavor of kopi luwak, but the biological basis has not been determined. Therefore, we characterized the microbiome of civet cat feces using 16S rRNA gene sequences to determine the bacterial taxa that may influence fermentation processes related to kopi luwak. Moreover, we compared this fecal microbiome with that of 14 other animals, revealing that Gluconobacter is a genus that is, uniquely found in feces of the civet cat. We also found that Gluconobacter species have a large number of cell motility genes, which may encode flagellar proteins allowing colonization of the civet gut. In addition, genes encoding enzymes involved in the metabolism of hydrogen sulfide and sulfur-containing amino acids were over-represented in Gluconobacter. These genes may contribute to the fermentation of coffee beans in the digestive tract of civet cats.
  11. Shafie AA, Ng CH, Tan YP, Chaiyakunapruk N
    Pharmacoeconomics, 2017 02;35(2):141-162.
    PMID: 27752998 DOI: 10.1007/s40273-016-0456-2
    BACKGROUND: Insulin analogues have a pharmacokinetic advantage over human insulin and are increasingly used to treat diabetes mellitus. A summary of their cost effectiveness versus other available treatments was required.

    OBJECTIVE: Our objective was to systematically review the published cost-effectiveness studies of insulin analogues for the treatment of patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM).

    METHODS: We searched major databases and health technology assessment agency reports for economic evaluation studies published up until 30 September 2015. Two reviewers performed data extraction and assessed the quality of the data using the CHEERS (Consolidated Health Economic Evaluation Reporting Standards) guidelines.

    RESULTS: Seven of the included studies assessed short-acting insulin analogues, 12 assessed biphasic insulin analogues, 30 assessed long-acting insulin analogues and one assessed a combination of short- and long-acting insulin analogues. Only 17 studies involved patients with T1DM, all were modelling studies and 12 were conducted in Canada. The incremental cost-effectiveness ratios (ICERs) for short-acting insulin analogues ranged from dominant to $US435,913 per quality-adjusted life-year (QALY) gained, the ICERs for biphasic insulin analogues ranged from dominant to $US57,636 per QALY gained and the ICERs for long-acting insulin analogues ranged from dominant to $US599,863 per QALY gained. A total of 15 studies met all the CHEERS guidelines reporting quality criteria. Only 26 % of the studies assessed heterogeneity in their analyses.

    CONCLUSION: Current evidence indicates that insulin analogues are cost effective for T1DM; however, evidence for their use in T2DM is not convincing. Additional evidence regarding compliance and efficacy is required to support the broader use of long-acting and biphasic insulin analogues in T2DM. The value of insulin analogues depends strongly on reductions in hypoglycaemia event rates and its efficacy in lowering glycated haemoglobin (HbA1c).

  12. Ng CH, Lee KT, Taib NA, Yip CH
    Singapore Med J, 2010 Apr;51(4):306-10.
    PMID: 20505908
    With an increasing number of women undergoing breast screening, an effective method of removing non-palpable lumps detected by mammography or sonography is by hookwire localisation excision biopsy (HWLB). The aim of this paper was to audit the practice of HWLB at the University Malaya Medical Centre.
  13. Ng CH, Akhter A, Yurko N, Burgener JM, Rosonina E, Manley JL
    Nat Commun, 2015 Mar 13;6:6610.
    PMID: 25766875 DOI: 10.1038/ncomms7610
    The small ubiquitin-like modifier (SUMO) is implicated in various cellular activities, including transcriptional regulation. We previously showed that the yeast activator Gcn4 becomes sumoylated during activation, facilitating its eventual promoter eviction and transcriptional shut off. Here we show that the corepressor Tup1 is sumoylated, at two specific lysines, under various stress conditions. Mutation of these sites has no effect on Tup1 recruitment or RNAP II promoter occupancy immediately following induction. However, Tup1 levels subsequently decrease, while RNAP II and transcription increase in Tup1 mutant cells. Consistent with this, a Tup1 mutant displaying increased sumoylation led to reduced transcription. We also show that coordinated sumoylation of Gcn4 and Tup1 enhances Gcn4 promoter eviction and that multiple Tup1-interacting proteins become sumoylated after stress. Together, our studies provide evidence that coordinated sumoylation of Gcn4, Tup1 and likely other factors dampens activated transcription by stabilizing Tup1 binding and stimulating Gcn4 and RNAP II removal.
  14. Ng CH, Kong SM, Tiong YL, Maah MJ, Sukram N, Ahmad M, et al.
    Metallomics, 2014 Apr;6(4):892-906.
    PMID: 24549332 DOI: 10.1039/c3mt00276d
    Copper compounds can be alternatives to platinum-based anticancer drugs. This study investigated the effects of a series of ternary copper(II) complexes, [Cu(phen)(aa)(H2O)]NO3·xH2O 1-4 (phen = 1,10-phenanthroline; aa = gly (1), DL-ala (2), sar (3), C-dmg (4)), on metastatic and cisplatin-resistant MDA-MB-231 breast cancer cells and MCF10A non-cancerous breast cells, and some aspects of the mechanisms. These complexes were distinctively more antiproliferative towards and induced greater apoptotic cell death in MDA-MB-231 than in MCF10A cells. 2 and 4 could induce cell cycle arrest only in cancer cells. Further evidence from DCFH-DA assay showed higher induction of reactive oxygen species (ROS) in treated cancer cells but minimal ROS increase in normal cells. DNA double-strand breaks, via a γ-H2AX assay, were only detected in cancer cells treated with 5 μM of the complexes. These complexes poorly inhibited chymotrypsin-like activity in the 20S rabbit proteasome while they did not inhibit the three proteolytic sites of MDA-MB-231 cells at 10 μM. However, the complexes could inhibit degradation of ubiquinated proteins of MDA-MB-231 cells. In addition, compound 4 was found to be effective against cervical (Hela), ovarian (SKOV3), lung (A549, PC9), NPC (Hone1, HK1, C666-1), breast (MCF7, T47D), lymphoma and leukemia (Nalmawa, HL60) and colorectal (SW480, SW48, HCT118) cancer cell lines with IC50 values (24 h) in the 1.7-19.0 μM range. Single dose NCI60 screening of 4 showed the complex to be highly cytotoxic to most cancer cell types and more effective than cisplatin.
  15. Tasman A, Alcaron RD, Chiu HF, Herrman H, Ng CH
    Asia Pac Psychiatry, 2013 Apr;5 Suppl 1:1.
    PMID: 23857828 DOI: 10.1111/appy.12071
  16. Ng CH, Pathy NB, Taib NA, Mun KS, Rhodes A, Yip CH
    Asian Pac J Cancer Prev, 2012;13(4):1111-3.
    PMID: 22799290
    The ER-/PR+ breast tumor may be the result of a false ER negative result. The aim of this study was to investigate whether there is a difference in patient and tumor characteristics of the ER-/PR+ phenotype in an Asian setting. A total of 2629 breast cancer patients were categorized on the basis of their age, ethnicity, tumor hormonal receptor phenotype, grade and histological type. There were 1230 (46.8%) ER+/PR+, 306 (11.6%) ER+/PR-, 122 (4.6%) ER-/PR+ and 972 (37%) ER-/PR-. ER-/PR+ tumors were 2.5 times more likely to be younger than 50 years at diagnosis (OR: 2.52; 95% CI: 1.72-3.67). Compared to ER+/PR+ tumors, the ER-/ PR+ phenotype was twice more likely to be associated with grade 3 tumors (OR:2.02; 95%CI: 1.00-4.10). In contrast, compared to ER-/PR- tumors, the ER-/PR+ phenotype was 90% less likely to be associated with a grade 3 tumor (OR: 0.12; 95%CI:0.05-0.26), and more likely to have invasive lobular than invasive ductal histology (OR: 3.66; 95%CI: 1.47-9.11). These results show that the ER-/PR+ phenotype occurs in a younger age group and is associated with intermediate histopathological characteristics compared to ER+/PR+ and ER-/PR- tumors. This may imply that it is a distinct entity and not a technical artifact.
  17. Tnah LH, Lee CT, Lee SL, Ng KK, Ng CH, Hwang SS
    Am J Bot, 2011 May;98(5):e130-2.
    PMID: 21613180 DOI: 10.3732/ajb.1000469
    Microsatellite markers of an important medicinal plant, Eurycoma longifolia (Simaroubaceae), were developed for DNA profiling and genetic diversity studies.
  18. Ng CH, Pathy NB, Taib NA, Teh YC, Mun KS, Amiruddin A, et al.
    Asian Pac J Cancer Prev, 2011;12(11):2943-6.
    PMID: 22393968
    INTRODUCTION: The age standardised incidence rate (ASR) of breast cancer in Malaysia which is a high middle- income country is similar to Indonesia, a low middle-income country. (Globocan 2008) It is however unknown whether the presentation of breast cancer differs between these two countries.

    OBJECTIVE: We compared the stage, age at presentation, and pathological characteristics of breast cancer between two tertiary hospitals in Indonesia and Malaysia; Dharmais Cancer Centre (DCC), which is the national cancer referral centre in Indonesia, and University Malaya Medical Centre (UMMC), which is an academic hospital with established breast oncology services in Kuala Lumpur. One thousand, one hundred and fourteen consecutive women (477 in UMMC: 637 in DCC) who were newly diagnosed with breast cancer between January and December, 2010 were included. Patient's age, TNM stage at presentation, and pathological characteristics were compared. Estrogen receptor (ER) and progesterone receptor (PR) were considered positive if 10% or greater of invasive cell nuclei were stained while HER2 was considered positive with an immunohistochemistry staining intensity of 3+ . Logistic regression analyses were performed to identify differences.
    RESULTS: Median age at diagnosis was 52 years in UMMC and 47 years in DCC, whereby patients in DCC were more likely to be very young at diagnosis (aged < 35 years) compared to their counterparts in UMMC (Odds ratio (OR): 2.09; 95%CI: 1.32-3.31). Approximately one third of patients in UMMC presented with TNM stage III or IV, compared to 63% in DCC. Patients in DCC were three times more likely to present with metastatic breast cancer compared to patients in UMMC (OR: 3.01; 95% CI: 2.02-4.48). The percentage of low grade tumours in DCC was higher than in UMMC (28% vs 11% respectively), and the difference persisted even after multivariate adjustment. Although the frequency of ER and PR positivity appeared to be higher in UMMC (65% and 55% respectively) compared to DCC (48% and 40% respectively), these differences were not statistically significant following adjustment for age, stage, HER2 status and grade. The frequency of HER2 positivity was 45% in DCC compared to 26% in UMMC, and remained significantly higher even after multivariate adjustment (multivariate OR:1.76; 95%CI:1.25-2.47, in DCC compared to UMMC). The proportion of triple negative breast cancer was however similar in the two centres (19% in UMMC vs 21% in DCC).
    CONCLUSION: Indonesian women with breast cancer seem to present at a younger age and at later stages compared to Malaysian women. Their tumors were more likely to be of low grade and HER2 positive, even after adjustment for other factors, while hormone receptor positivity proved similar in the two groups. The higher HER2 positivity rate in Indonesian patients warrants further study.
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