MyMedR

148 patients, 79 males and 60 females were seen in 1978 at Medical Unit Universiti Kebangsaan Kuala Lumpur. For majority of the patients the attacks of asthma begin at an early age. History of allergies were found in majority of the patients. Family history of asthma was noted in about 50%. Of the allergens that triggers of an attack of asthma, household dusts, rhinitis and pollen tops the list. Of the food the common allergens were shrimps, eggs and crabs. Most of the above allergens can be avoided or counteracted.
Study site: Medical Unit, Hospital Kuala Lumpur (UKM unit), Malaysia

Fulltext Cardiac arrhythmias and echocardiographic features in Wolff-Parkinson-White syndrome

Ng WH, Kew ST

Med J Malaysia, 1980 Sep;35(1):41-5.

PMID: 7253998

Electrocardiographic features of the Woljf-Parkinson-White syndrome may be seen in normal individuals and in those with congenital or acquired heart disease. Predisposition to tachyarrhythmias and its misinterpretation are common. In this report a case of Wolff-Parkinson-White syndrome in a 25 year old Malay male who presented with cardiac arrhythmias is described. Echocardiographic findings and the role of echocardiography are discussed.

Fulltext Infective endocarditis of the aorta valve--demonstration of valvular vegetations by M-Mode and Cross-Sectional echocardiography

Ng WH

Med J Malaysia, 1981 Dec;36(4):205-8.

PMID: 7334953

The ability to visualise valvular vegetations by echocardiography is a significant advantage in the management oj patients with infective endocarditis. In this report the M-Mode and Cross-Sectional echocardiographic appearances oj infective endocarditis affecting the aortic valve are described. The uses and limitations of echocardiography are discussed.

Fulltext Mortality in the early phase of acute myocardial infarction: a 3 year experience in the coronary care unit

Ng WH

Med J Malaysia, 1982 Mar;37(1):66-9.

PMID: 7121350

Mortality in the early phase of acute myocardial infarction occurs both during the pre-hospital period and after admission to the Coronary Care Unit. This report is an analysis of deaths that occurred in the Coronary Care Unit within a 3 year period. Forty percent of 304 patients (13 percent) unth. acute myocardial infarction died in the Coronary Care Unit, Fifty percent of the deaths were due to cardiac arrhythmias and 45 percent attributable to myocardial pump failure. Mean delay in hospital admission from onset of symptoms was 15 hours. Factors affecting early mortality and their prevention are discussed.

Fulltext A profile of acute myocardial infarction in urban Malays

Bakar R, Ng WH, Kew ST, Mohan A

Med J Malaysia, 1982 Mar;37(1):62-5.

PMID: 7121349

This is a retrospectioe study of epidemiological and riskfactors ofischaemic heart disease in Malay patients admitted into the Coronary Care Unit, General Hospital, Kuala Lumpur between October 1977 and December 1979 unth. proven myocardial infarction. Ofthe 116patients (M/F sex ratio 9.5 : 1), the incidence of various risk factors were smoking 82 percent, hypertension 42 percent, hypercholesterolemia 23 percent, diabetes mellitus 20 percent and family history 9 percent. Anterior infarctions were more common than inferior. Hyperuricemia was detected in 19 percent and 96 percent had at least one major riskfactor. In terms ofoccupation, a majorproportion ofthose afflicted were pensioners, security personnel and businessmen.

Analysis and functional annotation of expressed sequence tags (ESTs) from multiple tissues of oil palm (Elaeis guineensis Jacq.)

Ho CL, Kwan YY, Choi MC, Tee SS, Ng WH, Lim KA, et al.

BMC Genomics, 2007;8:381.

PMID: 17953740

Oil palm is the second largest source of edible oil which contributes to approximately 20% of the world's production of oils and fats. In order to understand the molecular biology involved in in vitro propagation, flowering, efficient utilization of nitrogen sources and root diseases, we have initiated an expressed sequence tag (EST) analysis on oil palm.

Human mesenchymal stem cells promote CD34+hematopoietic stem cell proliferation with preserved red blood cell differentiation capacity

Lau SX, Leong YY, Ng WH, Ng AWP, Ismail IS, Yusoff NM, et al.

Cell Biol Int, 2017 Jun;41(6):697-704.

PMID: 28403524 DOI: 10.1002/cbin.10774

Studies showed that co-transplantation of mesenchymal stem cells (MSCs) and cord blood-derived CD34+hematopoietic stem cells (HSCs) offered greater therapeutic effects but little is known regarding the effects of human Wharton's jelly derived MSCs on HSC expansion and red blood cell (RBC) generation in vitro. This study aimed to investigate the effects of MSCs on HSC expansion and differentiation. HSCs were co-cultured with MSCs or with 10% MSCs-derived conditioned medium, with HSCs cultured under standard medium served as a control. Cell expansion rates, number of mononuclear cell post-expansion and number of enucleated cells post-differentiation were evaluated. HSCs showed superior proliferation in the presence of MSC with mean expansion rate of 3.5 × 108 ± 1.8 × 107after day 7 compared to the conditioned medium and the control group (8.9 × 107 ± 1.1 × 108and 7.0 × 107 ± 3.3 × 106respectively, P

Fulltext Cardiac Stem Cells for Myocardial Regeneration: They Are Not Alone

Leong YY, Ng WH, Ellison-Hughes GM, Tan JJ

Front Cardiovasc Med, 2017;4:47.

PMID: 28770214 DOI: 10.3389/fcvm.2017.00047

Heart failure is the number one killer worldwide with ~50% of patients dying within 5 years of prognosis. The discovery of stem cells, which are capable of repairing the damaged portion of the heart, has created a field of cardiac regenerative medicine, which explores various types of stem cells, either autologous or endogenous, in the hope of finding the "holy grail" stem cell candidate to slow down and reverse the disease progression. However, there are many challenges that need to be overcome in the search of such a cell candidate. The ideal cells have to survive the harsh infarcted environment, retain their phenotype upon administration, and engraft and be activated to initiate repair and regeneration in vivo. Early bench and bedside experiments mostly focused on bone marrow-derived cells; however, heart regeneration requires multiple coordinations and interactions between various cell types and the extracellular matrix to form new cardiomyocytes and vasculature. There is an observed trend that when more than one cell is coadministered and cotransplanted into infarcted animal models the degree of regeneration is enhanced, when compared to single-cell administration. This review focuses on stem cell candidates, which have also been tested in human trials, and summarizes findings that explore the interactions between various stem cells in heart regenerative therapy.

Bioengineering the innate vasculature of complex organs: what have we learned so far

Wijesekara P, Ng WH, Feng M, Ren X

Curr Opin Organ Transplant, 2018 12;23(6):657-663.

PMID: 30234735 DOI: 10.1097/MOT.0000000000000577

PURPOSE OF REVIEW: Engineering vasculature that meets an organ's specific physiology and function is a fundamental step in organ bioengineering. In this article, we review approaches for engineering functional vasculature for organ bioengineering, with an emphasis on the engineering of organ-specific endothelium and vasculature.

RECENT FINDINGS: Recent advances in hydrogel-based engineering of vascularized organ bud enable vascular regeneration in self-assembled cellular niche containing parenchymal and stromal cells. The emerging technology of whole-organ decellularization provides scaffold materials that serve as extracellular niche guiding vascular regeneration to recapitulate native organ's vascular anatomy. Increasing morphological and molecular evidences suggest endothelial heterogeneity across different organs and across different vascular compartments within an organ. Deriving organ-specific endothelium from pluripotent stem cells has been shown to be possible by combining endothelial induction with parenchymal differentiation.

SUMMARY: Engineering organ-specific vasculature requires the combination of organ-specific endothelium with its unique cellular and extracellular niches. Future investigations are required to further delineate the mechanisms for induction and maintenance of organ-specific vascular phenotypes, and how to incorporate these mechanisms to engineering organ-specific vasculature.

Guided evaluation and standardisation of mesenchymal stem cell culture conditions to generate conditioned medium favourable to cardiac c-kit cell growth

Ng WH, Umar Fuaad MZ, Azmi SM, Leong YY, Yong YK, Ng AMH, et al.

Cell Tissue Res, 2019 Feb;375(2):383-396.

PMID: 30232595 DOI: 10.1007/s00441-018-2918-7

Mesenchymal stem cells (MSCs) are known to secrete cardioprotective paracrine factors that can potentially activate endogenous cardiac c-kit cells (CCs). This study aims to optimise MSC growth conditions and medium formulation for generating the conditioned medium (CdM) to facilitate CC growth and expansion in vitro. The quality of MSC-CdM after optimisation of seeding density during MSC stabilisation and medium formulation used during MSC stimulation including glucose, ascorbic acid, serum and oxygen levels and the effects of treatment concentration and repeated CdM harvesting were assessed based on CC viability in vitro under growth factor- and serum-deprived condition. Our data showed that functional CdM can be produced from MSCs with a density of 20,000 cells/cm2, which were stimulated using high glucose (25 mM), ascorbic acid supplemented, serum-free medium under normoxic condition. The generated CdM, when applied to growth factor- and serum-deprived medium at 1:1 ratio, improved CC viability, migration and proliferation in vitro. Such an effect could further be augmented by generating CdM concentrates without compromising CC gene and protein expressions, while retaining its capability to undergo differentiation to form endothelial, smooth muscle and cardiomyocytes. Nevertheless, CdM could not be repeatedly harvested from the same MSC culture, as the protein content and its effect on CC viability deteriorated after the first harvest. In conclusion, this study provides a proof-of-concept strategy to standardise the production of CdM from MSCs based on rapid, stepwise assessment of CC viability, thus enabling production of CdM favourable to CC growth for in vitro or clinical applications.

Occurrence of zoonotic Cryptosporidium and Giardia duodenalis species/genotypes in urban rodents

Tan TK, Low VL, Ng WH, Ibrahim J, Wang D, Tan CH, et al.

Parasitol Int, 2019 Apr;69:110-113.

PMID: 30590124 DOI: 10.1016/j.parint.2018.12.007

This report describes the detection of zoonotic Cryptosporidium muris, C. parvum subgenotype IIa and Giardia duodenalis genotype B in urban rodents in Malaysia. A rare occurrence of C. meleagridis was also reported suggesting a role of rodents in mechanical transmission of this pathogen. Utilization of DNA sequencing and subtyping analysis confirmed the presence of zoonotic C. parvum subtypes IIaA17G2R1 and IIaA16G3R1 for the first time in rodents.

Mesenchymal stem cells facilitate cardiac differentiation in Sox2-expressing cardiac C-kit cells in coculture

Leong YY, Ng WH, Umar Fuaad MZ, Ng CT, Ramasamy R, Lim V, et al.

J Cell Biochem, 2019 06;120(6):9104-9116.

PMID: 30548289 DOI: 10.1002/jcb.28186

Stem cell therapy offers hope to reconstitute injured myocardium and salvage heart from failing. A recent approach using combinations of derived Cardiac-derived c-kit expressing cells (CCs) and mesenchymal stem cells (MSCs) in transplantation improved infarcted hearts with a greater functional outcome, but the effects of MSCs on CCs remain to be elucidated. We used a novel two-step protocol to clonogenically amplify colony forming c-kit expressing cells from 4- to 6-week-old C57BL/6N mice. This method yielded highly proliferative and clonogenic CCs with an average population doubling time of 17.2 ± 0.2, of which 80% were at the G1 phase. We identified two distinctly different CC populations based on its Sox2 expression, which was found to inversely related to their nkx2.5 and gata4 expression. To study CCs after MSC coculture, we developed micron-sized particles of iron oxide-based magnetic reisolation method to separate CCs from MSCs for subsequent analysis. Through validation using the sex and species mismatch CC-MSC coculture method, we confirmed that the purity of the reisolated cells was greater than 85%. In coculture experiment, we found that MSCs prominently enhanced Ctni and Mef2c expressions in Sox2 pos CCs after the induction of cardiac differentiation, and the level was higher than that of conditioned medium Sox2 pos CCs. However, these effects were not found in Sox2 neg CCs. Immunofluorescence labeling confirmed the presence of cardiac-like cells within Sox2 pos CCs after differentiation, identified by its cardiac troponin I and α-sarcomeric actinin expressions. In conclusion, this study shows that MSCs enhance CC differentiation toward cardiac myocytes. This enhancement is dependent on CC stemness state, which is determined by Sox2 expression.

Fulltext Human Wharton's Jelly-Derived Mesenchymal Stem Cells Minimally Improve the Growth Kinetics and Cardiomyocyte Differentiation of Aged Murine Cardiac c-kit Cells in In Vitro without Rejuvenating Effect

Ng WH, Yong YK, Ramasamy R, Ngalim SH, Lim V, Shaharuddin B, et al.

Int J Mol Sci, 2019 Nov 06;20(22).

PMID: 31698679 DOI: 10.3390/ijms20225519

Cardiac c-kit cells show promise in regenerating an injured heart. While heart disease commonly affects elderly patients, it is unclear if autologous cardiac c-kit cells are functionally competent and applicable to these patients. This study characterised cardiac c-kit cells (CCs) from aged mice and studied the effects of human Wharton's Jelly-derived mesenchymal stem cells (MSCs) on the growth kinetics and cardiac differentiation of aged CCs in vitro. CCs were isolated from 4-week- and 18-month-old C57/BL6N mice and were directly co-cultured with MSCs or separated by transwell insert. Clonogenically expanded aged CCs showed comparable telomere length to young CCs. However, these cells showed lower Gata4, Nkx2.5, and Sox2 gene expressions, with changes of 2.4, 3767.0, and 4.9 folds, respectively. Direct co-culture of both cells increased aged CC migration, which repopulated 54.6 ± 4.4% of the gap area as compared to aged CCs with MSCs in transwell (42.9 ± 2.6%) and CCs without MSCs (44.7 ± 2.5%). Both direct and transwell co-culture improved proliferation in aged CCs by 15.0% and 16.4%, respectively, as traced using carboxyfluorescein succinimidyl ester (CFSE) for three days. These data suggest that MSCs can improve the growth kinetics of aged CCs. CCs retaining intact telomere are present in old hearts and could be obtained based on their self-renewing capability. Although these aged CCs with reduced growth kinetics are improved by MSCs via cell-cell contact, the effect is minimal.

Fulltext Extracellular matrix from decellularized mesenchymal stem cells improves cardiac gene expressions and oxidative resistance in cardiac C-kit cells

Ng WH, Ramasamy R, Yong YK, Ngalim SH, Lim V, Shaharuddin B, et al.

Regen Ther, 2019 Dec;11:8-16.

PMID: 31193142 DOI: 10.1016/j.reth.2019.03.006

OBJECTIVE: Myocardial infarction remains the number one killer disease worldwide. Cellular therapy using cardiac c-kit cells (CCs) are capable of regenerating injured heart. Previous studies showed mesenchymal stem cell-derived (MSC) extracellular matrices can provide structural support and are capable of regulating stem cell functions and differentiation. This study aimed to evaluate the effects of human MSC-derived matrices for CC growth and differentiation.

METHODS: Human Wharton's Jelly-derived MSCs were cultured in ascorbic acid supplemented medium for 14 days prior to decellularisation using two methods. 1% SDS/Triton X-100 (ST) or 20 mM ammonia/Triton X-100 (AT). CCs isolated from 4-week-old C57/BL6N mice were cultured on the decellularised MSC matrices, and induced to differentiate into cardiomyocytes in cardiogenic medium for 21 days. Cardiac differentiation was assessed by immunocytochemistry and qPCR. All data were analysed using ANOVA.

RESULTS: In vitro decellularisation using ST method caused matrix delamination from the wells. In contrast, decellularisation using AT improved the matrix retention up to 30% (p

Fulltext Conditioned Medium of Human Menstrual Blood-Derived Endometrial Stem Cells Protects Against MPP+-Induced Cytotoxicity in vitro

Li H, Yahaya BH, Ng WH, Yusoff NM, Lin J

Front Mol Neurosci, 2019;12:80.

PMID: 31024252 DOI: 10.3389/fnmol.2019.00080

Mesenchymal stem cells (MSCs) showed the potential to treat Parkinson's disease (PD). However, it is unknown whether the conditioned medium of human menstrual blood-derived endometrial stem cells (MenSCs-CM) has the function to alleviate syndromes of PD. In this study, human neuroblastoma SH-SY5Y cells were exposed to neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) for inducing a range of response characteristics of PD. After culturing this cell model with 24 h/48 h collected MenSCs-CM for different days, cell viability, pro-inflammation cytokines, mitochondrial membrane potential (ΔΨm), oxidative stress, and cell apoptosis were detected. Finally, protein assay was performed to detect 12 kinds of neurotrophic factors inside MenSCs-CM. Our results showed that MPP+ caused SH-SY5Y cell viability reduction as an increasing dose and time dependent manner. MPP+ treatment resulted in inflammation, mitochondrial dysfunction, reactive oxygen species (ROS) production accumulation, and apoptosis of SH-SY5Y at its IC50 concentration. Forty-eight hours-collected MenSCs-CM and culturing with the MPP+-treated SH-SY5Y for 2 days are the optimized condition to increase cell viability. Besides, MenSCs-CM was efficacious against MPP+ induced inflammation, ΔΨm loss, ROS generation, and it could significantly decrease cells numbers in late apoptosis stage. What's more, protein assay showed that MenSCs-CM contained various neuroprotective factors. Our study provided the first evidence that MenSCs-CM has a protective effect on MPP+-induced cytotoxicity in various aspects, and firstly showed that MenSCs can release at least 12 kinds of neurotrophic factors to medium, which may contribute to the protective function of MenSCs-CM to treat PD. This research enlightening that MenSCs-CM is beneficial in the therapy for PD and probably also for other neurodegenerative diseases.

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