Displaying publications 1 - 20 of 93 in total

  1. Ismail NA
    Malays J Med Sci, 2016 Mar;23(2):73-7.
    PMID: 27547118 MyJurnal
    This study explores the experience of both learners and a teacher during a team-based learning (TBL) session. TBL involves active learning that allows medical students to utilise their visual, auditory, writing and kinetic learning styles in order to strengthen their knowledge and retain it for longer, which is important with regard to applying basic sciences in clinical settings. This pilot study explored the effectiveness of TBL in learning medical genetics, and its potential to replace conventional lectures. First-year medical students (n = 194) studying at Universiti Kebangsaan, Malaysia, during 2014/2015 were selected to participate in this study. The topic of 'Mutation and Mutation Analysis' was selected, and the principles of TBL were adhered to during the study. It was found that the students' performance in a group readiness test was better than in individual readiness tests. The effectiveness of TBL was further shown in the examination, during which the marks obtained were tremendously improved. Collective commentaries from both the learners and the teacher recommended TBL as another useful tool in learning medical genetics. Implementation strategies should be advanced for the benefit of future learners and teachers.
  2. Ismail NA, Mohamed Ismail NA, Bador KM
    J Obstet Gynaecol, 2021 Aug;41(6):899-903.
    PMID: 33962550 DOI: 10.1080/01443615.2020.1820462
    We investigated if vitamin D is independently associated with hyperglycaemia in gestational diabetes mellitus (GDM). Serum 25 hydroxy vitamin D (25OHD), fasting blood glucose (FBG), HbA1c, fructosamine, insulin sensitivity (QUICKI equation), body mass index, clothing style and outdoor activity were measured in 58 pregnant women with GDM during the third trimester. 25OHD was also measured in 20 women with normal pregnancies. There was no significant difference in mean 25OHD concentrations between GDM (14.43 ± 5.27 ng/ml) and normal (15.45 ± 5.29 ng/ml) pregnancies, p = .354. However, a higher percentage of GDM subjects had 25OHD concentration <19.8 ng/ml (86 versus 65%, p = .003). 25OHD did not correlate with FBG, HbA1c, fructosamine, insulin sensitivity or insulin dosage (p > .05). On multivariate analysis, only ethnicity (p = .006) and outdoor activity (p = .004) were associated with 25OHD. We conclude that the lower 25OHD levels in our GDM patients were related to ethnicity and outdoor activity (Study FF-2017-111, National University of Malaysia, 16 March 2017).IMPACT STATEMENTWhat is already known on this subject? Vitamin D deficiency in pregnancy is widespread and particularly in certain ethnic groups. Low vitamin D levels may be an aetiological factor for gestational diabetes mellitus (GDM) but previous studies provide conflicting results perhaps due to confounding factors.What do the results of this study add? In this study of pregnant women with GDM from different ethnic backgrounds, we analysed serum 25-hydroxy vitamin D (25OHD) levels together with other confounding factors, that is, body mass index, ethnicity and sunlight exposure. Furthermore, instead of using consensus values, we determined cut-offs for different vitamin D status from normal pregnancies matched for gestational age and ethnicity. We found that a higher percentage of GDM subjects had lower vitamin D status but there was no correlation with hyperglycaemia or insulin sensitivity. The study showed that lower vitamin D levels in GDM was associated with ethnicity and less outdoor activity.What the implications are of these findings for clinical practice and/or further research? In GDM patients, low vitamin D levels may be modifiable by supplementation or lifestyle change. Longitudinal studies are needed to determine whether this would impact on the occurrence of GDM.
  3. Apenteng OO, Ismail NA
    PLoS One, 2014;9(6):e98288.
    PMID: 24911023 DOI: 10.1371/journal.pone.0098288
    Previous models of disease spread involving delay have used basic SIR (susceptible--infectious--recovery) formulae and approaches. This paper demonstrates how time-varying SEIRS (S--exposed--I - R - S) models can be extended with delay to produce wave propagations that simulate periodic wave fronts of disease spread in the context of population movements. The model also takes into account the natural mortality associated with the disease spread. Understanding the delay of an infectious disease is critical when attempting to predict where and how fast the disease will propagate. We use cellular automata to model the delay and its effect on the spread of infectious diseases where population movement occurs. We illustrate an approach using wavelet transform analysis to understand the impact of the delay on the spread of infectious diseases. The results indicate that including delay provides novel ways to understand the effects of migration and population movement on disease spread.
  4. Wong RS, Ismail NA
    PLoS One, 2016;11(3):e0151949.
    PMID: 27007413 DOI: 10.1371/journal.pone.0151949
    There are not many studies that attempt to model intensive care unit (ICU) risk of death in developing countries, especially in South East Asia. The aim of this study was to propose and describe application of a Bayesian approach in modeling in-ICU deaths in a Malaysian ICU.
  5. Ismail NA, Jusoh SA
    Interdiscip Sci, 2017 Dec;9(4):499-511.
    PMID: 26969331 DOI: 10.1007/s12539-016-0157-8
    Dengue infections are currently estimated to be 390 million cases annually. Yet, there is no vaccine or specific therapy available. Envelope glycoprotein E (E protein) of DENV mediates viral attachment and entry into the host cells. Several flavonoids have been shown to inhibit HIV-1 and hepatitis C virus entry during the virus-host membrane fusion. In this work, molecular docking method was employed to predict the binding of nine flavonoids (baicalin, baicalein, EGCG, fisetin, glabranine, hyperoside, ladanein, quercetin and flavone) to the soluble ectodomain of DENV type 2 (DENV2) E protein. Interestingly, eight flavonoids were found to dock into the same binding pocket located between the domain I and domain II of different subunits of E protein. Consistent docking results were observed not only for the E protein structures of the DENV2-Thai and DENV2-Malaysia (a homology model) but also for the E protein structures of tick-borne encephalitis virus and Japanese encephalitis virus. In addition, molecular dynamics simulations were performed to further evaluate the interaction profile of the docked E protein-flavonoid complexes. Ile4, Gly5, Asp98, Gly100 and Val151 residues of the DENV2-My E protein that aligned to the same residues in the DENV2-Thai E protein form consistent hydrogen bond interactions with baicalein, quercetin and EGCG during the simulations. This study demonstrates flavonoids potentially form interactions with the E protein of DENV2.
  6. Apenteng OO, Ismail NA
    PLoS One, 2015;10(7):e0131950.
    PMID: 26147199 DOI: 10.1371/journal.pone.0131950
    The spread of human immunodeficiency virus (HIV) infection and the resulting acquired immune deficiency syndrome (AIDS) is a major health concern in many parts of the world, and mathematical models are commonly applied to understand the spread of the HIV epidemic. To understand the spread of HIV and AIDS cases and their parameters in a given population, it is necessary to develop a theoretical framework that takes into account realistic factors. The current study used this framework to assess the interaction between individuals who developed AIDS after HIV infection and individuals who did not develop AIDS after HIV infection (pre-AIDS). We first investigated how probabilistic parameters affect the model in terms of the HIV and AIDS population over a period of time. We observed that there is a critical threshold parameter, R0, which determines the behavior of the model. If R0 ≤ 1, there is a unique disease-free equilibrium; if R0 < 1, the disease dies out; and if R0 > 1, the disease-free equilibrium is unstable. We also show how a Markov chain Monte Carlo (MCMC) approach could be used as a supplement to forecast the numbers of reported HIV and AIDS cases. An approach using a Monte Carlo analysis is illustrated to understand the impact of model-based predictions in light of uncertain parameters on the spread of HIV. Finally, to examine this framework and demonstrate how it works, a case study was performed of reported HIV and AIDS cases from an annual data set in Malaysia, and then we compared how these approaches complement each other. We conclude that HIV disease in Malaysia shows epidemic behavior, especially in the context of understanding and predicting emerging cases of HIV and AIDS.
  7. Ismail NA, Jenatabadi HS
    Transp Res Part A Policy Pract, 2014 Sep;67:212-224.
    PMID: 32288368 DOI: 10.1016/j.tra.2014.06.010
    The ways in which airline performance depends on the economic situation and internal operation are well established in the literature. One of the contextual factors that may change the nature of these relationships is firm age. As such, the aim of this study is to investigate the moderating influence of firm age on airline performance outcomes. Thirty airline companies from the Asia Pacific region were selected, and relevant data from 2006 to 2011 were collected. It can be deduced that company experience or firm age can help in taking control of the relationship between the constructs; thus, this measurement acts as a moderator in the research model.
  8. Ismail NA, Pettitt AN
    Stat Med, 2004 Apr 30;23(8):1247-58.
    PMID: 15083481
    A new method for estimating the time to colonization of Methicillin-resistant Staphylococcus Aureus (MRSA) patients is developed in this paper. The time to colonization of MRSA is modelled using a Bayesian smoothing approach for the hazard function. There are two prior models discussed in this paper: the first difference prior and the second difference prior. The second difference prior model gives smoother estimates of the hazard functions and, when applied to data from an intensive care unit (ICU), clearly shows increasing hazard up to day 13, then a decreasing hazard. The results clearly demonstrate that the hazard is not constant and provide a useful quantification of the effect of length of stay on the risk of MRSA colonization which provides useful insight.
  9. Zaki R, Bulgiba A, Ismail R, Ismail NA
    PLoS One, 2012;7(5):e37908.
    PMID: 22662248 DOI: 10.1371/journal.pone.0037908
    Accurate values are a must in medicine. An important parameter in determining the quality of a medical instrument is agreement with a gold standard. Various statistical methods have been used to test for agreement. Some of these methods have been shown to be inappropriate. This can result in misleading conclusions about the validity of an instrument. The Bland-Altman method is the most popular method judging by the many citations of the article proposing this method. However, the number of citations does not necessarily mean that this method has been applied in agreement research. No previous study has been conducted to look into this. This is the first systematic review to identify statistical methods used to test for agreement of medical instruments. The proportion of various statistical methods found in this review will also reflect the proportion of medical instruments that have been validated using those particular methods in current clinical practice.
  10. Zaki R, Bulgiba A, Ismail NA
    Prev Med, 2013;57 Suppl:S80-2.
    PMID: 23313586 DOI: 10.1016/j.ypmed.2013.01.003
    The Bland-Altman method is the most popular method used to assess the agreement of medical instruments. The main concern about this method is the presence of proportional bias. The slope of the regression line fitted to the Bland-Altman plot should be tested to exclude proportional bias. The aim of this study was to determine whether the overestimation of bias in the Bland-Altman analysis is still present even when the proportional bias has been excluded.
  11. Zamli AH, Ismail NA, Ong KG
    Spinal Cord Ser Cases, 2016;2:15038.
    PMID: 28053740 DOI: 10.1038/scsandc.2015.38
    High-amplitude penile vibratory stimulation (PVS) is recommended as the first line method for conservative sperm retrieval in anejaculatory Caucasian men with spinal cord injury (SCI). Evidence of its effectiveness in Asian population is lacking. We described the effectiveness of high amplitude PVS for conservative sperm retrieval in the anejaculatory local men with SCI. Records of all SCI patients referred for conservative sperm retrieval trial from August 2014 to August 2015 were screened. Those who failed in artificial stimulation methods for sperm retrieval including masturbation, prostatic massage and low amplitude PVS were subjected to high amplitude PVS using Viberect X3. Data pertaining to detailed neurological findings, time to ejaculate, seminal fluid volume and its gross appearance, somatic responses at ejaculation and any adverse events were retrieved. Successful outcome is defined as occurrence of antegrade ejaculation. Thirteen out of 16 patients fulfilled all study criteria. 46% of the patients had neurological level above T6 followed by 34% with neurological level between T7-T12. Preserved reflexogenic and spontaneous erection were reported by 84.6% and successful coitus was reported by 45.4% of the patients. The overall ejaculatory success using high amplitude, high-frequency vibratory stimulation in our study was 46.15%. Among the patients with lesion at T6 and above, the ejaculatory success rate was 66.7% while for the study subjects with lesions below T6 was 33.3%. In conclusion, PVS outcome for sperm retrieval in asian population is comparable to that of Caucasian population. Its use is highly applicable in local population.
  12. Ismail NA, Hashim HA, Ahmad Yusof H
    Games Health J, 2022 Feb;11(1):1-17.
    PMID: 34851732 DOI: 10.1089/g4h.2021.0104
    Recently, exergames have been widely applied as exercise platforms among older adults. However, studies on the influence of exergames on older adults' physical activity remain scarce. The review article highlights the potential benefit of exergames as a physical activity tool for older adults. The literature search followed the PRISMA guidelines on databases PubMed (Public/Publisher MEDLINE), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, and Scopus. The literature included studies that evaluated the influence of exergames on older adults' physical activity. Articles were excluded if the mixed intervention was used, emphasizing specific limbs, improving specific tasks, or not mentioning intervention. The review article identified 25 studies that reported on 855 older adults 55 years of age and older. In addition, the common exergaming technology platforms examined were Microsoft Kinect™, Nintendo® Wii™, cybercycling, and interactive video dance games. Meanwhile, 11 studies used a pretest/post-test design and randomized controlled trial design in 14 studies. The review found that exergames significantly impacted the older adults' physical activity level as participants experienced improved balance and cognitive function, and enjoyed playing exergame, thus prolonging their game engagement. Although research on exergames is still new, current evidence showed a significant potential benefit of exergames as a physical activity tool for older adults. To overcome the limitation on various parameters that showed different effects and outcomes of exergames, the study recommends implementing randomized controlled trials with long-term observation using a mixed-method approach. Moreover, a multidisciplinary method involving exercise and neuromotor control experts could determine potential mechanisms of action that benefited from the exercises.
  13. Doufesh H, Ibrahim F, Ismail NA, Wan Ahmad WA
    J Altern Complement Med, 2014 Jul;20(7):558-62.
    PMID: 24827587 DOI: 10.1089/acm.2013.0426
    OBJECTIVES: This study investigated the effect of Muslim prayer (salat) on the α relative power (RPα) of electroencephalography (EEG) and autonomic nervous activity and the relationship between them by using spectral analysis of EEG and heart rate variability (HRV).

    METHODS: Thirty healthy Muslim men participated in the study. Their electrocardiograms and EEGs were continuously recorded before, during, and after salat practice with a computer-based data acquisition system (MP150, BIOPAC Systems Inc., Camino Goleta, California). Power spectral analysis was conducted to extract the RPα and HRV components.

    RESULTS: During salat, a significant increase (p

  14. Ismail NA, Baines DL, Wilson SM
    Eur J Pharmacol, 2014 Jun 05;732:32-42.
    PMID: 24657276 DOI: 10.1016/j.ejphar.2014.03.005
    Neural precursor cell expressed, developmentally down-regulated protein 4-2 (Nedd4-2) mediates the internalisation / degradation of epithelial Na(+) channel subunits (α-, β- and γ-ENaC). Serum / glucocorticoid inducible kinase 1 (SGK1) and protein kinase A (PKA) both appear to inhibit this process by phosphorylating Nedd4-2-Ser(221), -Ser(327) and -Thr(246). This Nedd4-2 inactivation process is thought to be central to the hormonal control of Na(+) absorption. The present study of H441 human airway epithelial cells therefore explores the effects of SGK1 and / or PKA upon the phosphorylation / abundance of endogenous Nedd4-2; the surface expression of ENaC subunits, and electrogenic Na(+) transport. Effects on Nedd4-2 phosphorylation/abundance and the surface expression of ENaC were monitored by western analysis, whilst Na(+) absorption was quantified electrometrically. Acutely (20min) activating PKA in glucocorticoid-deprived (24h) cells increased the abundance of Ser(221)-phosphorylated, Ser(327)-phosphorylated and total Nedd4-2 without altering the abundance of Thr(246)-phosphorylated Nedd4-2. Activating PKA under these conditions did not cause a co-ordinated increase in the surface abundance of α-, β- and γ-ENaC and had only a very small effect upon electrogenic Na(+) absorption. Activating PKA (20min) in glucocorticoid-treated (0.2µM dexamethasone, 24h) cells, on the other hand, increased the abundance of Ser(221)-, Ser(327)- and Thr(246)-phosphorylated and total Nedd4-2; increased the surface abundance of α-, β- and γ-ENaC and evoked a clear stimulation of Na(+) transport. Chronic glucocorticoid stimulation therefore appears to allow cAMP-dependent control of Na(+) absorption by facilitating the effects of PKA upon the Nedd4-2 and ENaC subunits.
  15. Rahman RA, Ahmad S, Ismail NA, Mahdy ZA
    J Reprod Med, 2012 Sep-Oct;57(9-10):456-8.
    PMID: 23091998
    The incidence of a coexistent normal fetus is quoted in literature as 1 in 22,000 to 100,000 pregnancies and may be associated with multiple complications including persistent trophoblastic neoplasia.
  16. Sambasevam KP, Mohamad S, Sarih NM, Ismail NA
    Int J Mol Sci, 2013;14(2):3671-82.
    PMID: 23434664 DOI: 10.3390/ijms14023671
    A β-cyclodextrin (β-Cyd) inclusion complex containing azomethine as a guest was prepared by kneading method with aliquot addition of ethanol. The product was characterized by Fourier Transform Infrared (FTIR) spectrometer, 1H Nuclear Magnetic Resonance (1H NMR) and Thermogravimetric Analyzer (TGA), which proves the formation of the inclusion complex where the benzyl part of azomethine has been encapsulated by the hydrophobic cavity of β-Cyd. The interaction of β-Cyd and azomethine was also analyzed by means of spectrometry by UV-Vis spectrophotometer to determine the formation constant. The formation constant was calculated by using a modified Benesi-Hildebrand equation at 25 °C. The apparent formation constant obtained was 1.29 × 104 L/mol. Besides that, the stoichiometry ratio was also determined to be 1:1 for the inclusion complex of β-Cyd with azomethine.
  17. Wong RS, Ismail NA, Tan CC
    Ann Acad Med Singap, 2015 Apr;44(4):127-32.
    PMID: 26041636
    INTRODUCTION: Intensive care unit (ICU) prognostic models are predominantly used in more developed nations such as the United States, Europe and Australia. These are not that popular in Southeast Asian countries due to costs and technology considerations. The purpose of this study is to evaluate the suitability of the acute physiology and chronic health evaluation (APACHE) IV model in a single centre Malaysian ICU.

    MATERIALS AND METHODS: A prospective study was conducted at the single centre ICU in Hospital Sultanah Aminah (HSA) Malaysia. External validation of APACHE IV involved a cohort of 916 patients who were admitted in 2009. Model performance was assessed through its calibration and discrimination abilities. A first-level customisation using logistic regression approach was also applied to improve model calibration.

    RESULTS: APACHE IV exhibited good discrimination, with an area under receiver operating characteristic (ROC) curve of 0.78. However, the model's overall fit was observed to be poor, as indicated by the Hosmer-Lemeshow goodness-of-fit test (Ĉ = 113, P <0.001). Predicted in-ICU mortality rate (28.1%) was significantly higher than the actual in-ICU mortality rate (18.8%). Model calibration was improved after applying first-level customisation (Ĉ = 6.39, P = 0.78) although discrimination was not affected.

    CONCLUSION: APACHE IV is not suitable for application in HSA ICU, without further customisation. The model's lack of fit in the Malaysian study is attributed to differences in the baseline characteristics between HSA ICU and APACHE IV datasets. Other possible factors could be due to differences in clinical practice, quality and services of health care systems between Malaysia and the United States.

  18. Ibrahim F, Ismail NA, Taib MN, Wan Abas WA
    Physiol Meas, 2004 Jun;25(3):607-15.
    PMID: 15253113 DOI: 10.1088/0967-3334/25/3/002
    This paper describes a model for predicting hemoglobin (Hb) by using bioelectrical impedance analysis (BIA) in dengue patients in the Hospital Universiti Kebangsaan Malaysia (HUKM). Bioelectrical impedance measurements were conducted on 83 (47 males and 36 females) serologically confirmed dengue fever (DF) and dengue hemorrhagic fever (DHF) patients during their hospitalization. The predictive equation for Hb was derived using multivariate analysis. We investigated all the parameters in BIA, patients' symptom and demographic data. In this developed model, four predictors (reactance (XC), sex, weight and vomiting) were found to be the best predictive factors for modeling Hb in dengue patients. However, the model can only explain approximately 42% of the variation in Hb status, thus single frequency bio-impedance stand-alone technique is insufficient to monitor Hb for the DF and DHF patients. Further investigation using multi-frequency BIA is recommended in modeling Hb to achieve the most parsimonious model.
  19. Ismail NA, Abu Bakar SN, Abdullah N, Shafie MS, Mohd Nor F
    Malays J Pathol, 2019 Aug;41(2):83-89.
    PMID: 31427544
    INTRODUCTION: Stature estimation is population dependent, and population-specific regression equations should be generated for accurate anthropological assessments. Nevertheless, stature estimation data was inaccessible and limited in some of the South-East Asian countries. The systematic review was conducted to analyse the regression equations of stature estimations developed in South-East Asian region.

    MATERIALS AND METHODS: A systematic literature search was performed through SCOPUS database and Google Scholar from January till March 2018. All published articles which developed stature estimation from different types of bone, methods and type of statures (i.e. living stature, forensic stature and cadaveric stature) were included in this study. Risks of biases were also assessed. Population studies with no regression equations were excluded from the study.

    RESULTS: Seven studies that met the inclusion criteria were identified. In the South-East Asia region, regression equations for stature estimation were developed in Thailand and Malaysia. In these studies, bone measurements were done either by radiography, direct bone measurement, or palpation on body surface for anatomical bony prominence. All of these studies used various parts of bones for stature estimation.

    CONCLUSION: The most widely used regression equations for stature estimation in South-East Asian population were from the Thailand population. Further research is recommended to develop regression equations for other South-East Asian countries.

  20. Ismail NA, Amin KAM, Majid FAA, Razali MH
    Mater Sci Eng C Mater Biol Appl, 2019 Oct;103:109770.
    PMID: 31349525 DOI: 10.1016/j.msec.2019.109770
    In this work, the potential of titanium dioxide nanoparticles incorporated gellan gum (GG + TiO2-NPs) biofilm as wound dressing material was investigated. The GG + TiO2-NPs biofilm was prepared via evaporative casting technique and was characterized using FTIR, XRD, and SEM to study their physiochemical properties. The mechanical properties, swelling and water vapor transmission rate (WVTR) of biofilm was determined to comply with an ideal wound dressing material. In vitro and in vivo wound healing studies was carried out to evaluate the performance of GG + TiO2-NPs biofilm. In vitro wound healing was studied on 3 T3 mouse fibroblast cells for cell viability, cell proliferation, and scratch assay. The acridine orange/propidium iodide (AO/PI) staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were used to evaluate the viability of cell and cell proliferation. Cell migration assay was analyzed using Essen BioScience IncuCyteTM Zoom system. In vivo wound healing via open excision wounds model on Sprague Dawley rat was studied within 14 days. The FT-IR spectra of GG + TiO2-NPs biofilm show main bands assigned to OH stretching, OH deformation, and TiO stretching modes. XRD pattern of GG + TiO2-NPs biofilm suggesting that TiO2-NPs was successfully incorporated in biofilm and well distributed on the surface as proved by SEM analysis. The GG + TiO2-NPs biofilm shows higher mechanical strength and swelling (3.76 ± 0.11 MPa and 1061 ± 6%) as compared to pure GG film (3.32 ± 0.08 Mpa and 902 ± 6%), respectively. GG + TiO2-NPs biofilm shows good antibacterial properties as 9 ± 0.25 mm and 11 ± 0.06 mm exhibition zone was observed against Staphylococcus aureus and Escherichia coli bacteria, respectively. While no exhibition zone was obtained for pure GG biofilm. GG + TiO2-NPs biofilm also demonstrated better cell-to-cell interaction properties, as it's promoted cell proliferation and cell migration to accelerate open excision wound healing on Sprague Dawley rat. The wound treated with GG + TiO2-NPs biofilm was healed within 14 days, on the other hand, the wound is still can be seen when it was treated with GG. However, GG and GG + TiO2-NPs biofilm show no cytotoxicity effects on mouse fibroblast cells.
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