Displaying publications 1 - 20 of 55 in total

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  1. Mitra NK, Siong HH, Nadarajah VD
    Ann Agric Environ Med, 2008;15(2):211-6.
    PMID: 19061257
    Dermal absorption of chlorpyrifos, an organophosphate insecticide is important because of its use in agriculture and control of household pests. The objectives of this study are to investigate firstly, the biochemical changes in the blood and secondly, histomorphometric changes in the hippocampus of adult mice following dermal application of chlorpyrifos in sub-toxic doses. Male Swiss albino mice (60 days) were segregated into one control and two treated groups (n=10). Chlorpyrifos, diluted with xylene, was applied in doses of 1/2 of LD(50) (E1) and 1/5 of LD(50) (E2) over the tail of mice of the two treated groups, 6 hours daily for 3 weeks. AChE levels in the serum and brain were estimated using a spectrophotometric method (Amplex Red reagent). Coronal serial sections were stained with 0.2 % thionin in acetate buffer and pyramidal neurons of Cornu Ammonis of hippocampus were counted at 400x magnification using Image Pro Express software. At the end of 3 weeks, body weights were reduced significantly in E1 group. Serum AChE concentrations were reduced by 97 % in E1 and 74 % in E2 groups compared to controls. The neurons of CA 3 and CA 1 in the hippocampus showed evidences of morphological damage in both treated groups. Furthermore, the neuronal count was significantly reduced in CA 3 layer of hippocampus in E1 group.
  2. Win NN, Nadarajah VD, Win DK
    PMID: 25961676 DOI: 10.3352/jeehp.2015.12.17
    PURPOSE: Problem-based learning (PBL) is usually conducted in small-group learning sessions with approximately eight students per facilitator. In this study, we implemented a modified version of PBL involving collaborative groups in an undergraduate chiropractic program and assessed its pedagogical effectiveness.
    METHODS: This study was conducted at the International Medical University, Kuala Lumpur, Malaysia, and involved the 2012 chiropractic student cohort. Six PBL cases were provided to chiropractic students, consisting of three PBL cases for which learning resources were provided and another three PBL cases for which learning resources were not provided. Group discussions were not continuously supervised, since only one facilitator was present. The students' perceptions of PBL in collaborative groups were assessed with a questionnaire that was divided into three domains: motivation, cognitive skills, and perceived pressure to work.
    RESULTS: Thirty of the 31 students (97%) participated in the study. PBL in collaborative groups was significantly associated with positive responses regarding students' motivation, cognitive skills, and perceived pressure to work (P<0.05). The students felt that PBL with learning resources increased motivation and cognitive skills (P<0.001).
    CONCLUSION: The new PBL implementation described in this study does not require additional instructors or any additional funding. When implemented in a classroom setting, it has pedagogical benefits equivalent to those of small-group sessions. Our findings also suggest that students rely significantly on available learning resources.
    KEYWORDS: Chiropractic; Learning; Motivation; Perception; Problem-based learning
  3. Mitra NK, Lee MS, Nadarajah VD
    Trop Biomed, 2010 Apr;27(1):19-29.
    PMID: 20562809
    Dermal exposure to organophosphate pesticide is important because of its popular use. This study planned to compare the changes in serum acetylcholinesterase, paraoxonase and neuronal density of hippocampus and iso-cortex between two age groups of Swiss albino mice (18-day-old and 150-day-old) after dermal application of (1/2) LD50 of chlorpyrifos for 14 days. Statistically significant reduction was observed in serum acetylcholinesterase (Mann-Whitney test, p<0.05) and neuronal density (Independent samples t-test, p<0.05) in exposed groups compared to the control. The reduction in serum AChE and neuronal density was more pronounced in exposed adult mice than in exposed neonatal mice. The paraoxonase level was insignificant in control neonatal mice, whereas it was 890-fold more in exposed neonatal mice. Upregulated paraoxonase levels may be extrapolated to produce relatively lower reduction of cholinesterase and neuronal density in neonatal mice.
  4. Chia CF, Nadarajah VD, Lim V, Kutzsche S
    Med Teach, 2021 Jul;43(sup1):S46-S52.
    PMID: 32552199 DOI: 10.1080/0142159X.2020.1776239
    BACKGROUND: Faculty development programmes should incorporate the transfer of knowledge, skills, and confidence from the training to educational practice. However, there is a risk that transfer may fail due to inadequate integration of knowledge, skills, and confidence. The study evaluated transfer levels, guided by learned principles from a faculty development programme.

    METHOD: The submitted self-reports on a pedagogical intervention of 92 out of 190 health professions educators who participated in a mandatory teaching and learning training programme, were analysed by a mixed-method approach guided by a structured conceptual framework.

    RESULTS: Overall 93.4% reported the successful transfer of learning. Participants incorporated sustainable changed practice (level A, 57.6%), showed reflection on the impact of changed practice (level B, 21.7%), and performed effect analysis (level C, 14.1%). The rest planned application of learning (level D, 4.4%) and identified gaps in current practice or developed an idea for educational intervention but did not implement (level E, 2.2%).

    CONCLUSION: The majority of participants transferred their learning. Faculty development programmes must ensure successful transfer of knowledge, skills, and confidence from the training to educational practice to ensure sustainable development of teaching and learning practices.

  5. Er HM, Wong PS, Nadarajah VD
    BMC Med Educ, 2023 Jun 02;23(1):397.
    PMID: 37268906 DOI: 10.1186/s12909-023-04368-0
    BACKGROUND: Open book examinations have been used to assess students' higher order cognitive skills. These examinations can be conducted online remotely with the advancement of technology. However, there are concerns regarding its validity and reliability particularly if the examinations are not proctored. The objective of this study was to explore the perceptions of faculty and students in health professions programmes about remote online open book examinations (ROOBE).

    METHODS: Semi-structured interviews were conducted among 22 faculty staff who were involved in ROOBE in health professions programmes. All interviews were audio recorded, transcribed verbatim and analysed using a thematic analysis approach. The perceptions of 249 medical students were obtained using an online questionnaire after they completed ROOBE.

    RESULTS: The faculty agreed that open book examinations could promote students' higher order cognitive skills and reduce students' stress. However, they were concerned about students' academic integrity during non-invigilated ROOBE which could affect recognition by accreditation and professional bodies. The shift from traditional practice of closed-book examinations to ROOBE required change management with the support of guidelines and faculty training.  Majority of the students claimed that the examinations were challenging as they assessed their ability to apply knowledge in real world problems. Nevertheless, they preferred ROOBE due to less anxiety and memorisation, and more emphasis on problem solving skills. The shortcomings were insufficient time for information searching during examinations and uncertainty in preparedness for future practice as they focused less on memorisation of factual knowledge during examination preparation. Cheating among peers and internet instability during non-invigilated ROOBE were the concerns highlighted by some students.

    CONCLUSIONS: Faculty and students expressed favourable views about ROOBE in promoting higher order cognitive skills. Adequate technological support was essential during ROOBE. While there was a need to address issues related to academic integrity, ROOBE could be included as an authentic assessment within the systems of assessment.

  6. Mitra NK, Nadarajah VD, Siong HH
    Folia Neuropathol, 2009;47(1):60-8.
    PMID: 19353435
    Dermal absorption of chlorpyrifos (CPF), an organophosphate (OP) pesticide, is important because of its popular use. Stress has been reported to exacerbate neurotoxic effects of certain OP pesticides; however, quantitative studies to corroborate this are not reported. This study correlates the changes in acetylcholinesterase (AChE) levels and neuronal counts in areas of the hippocampus to consecutive exposure of stress, heat and CPF. Male mice (60 days) were segregated into six groups: one control, one stress control, and four treated groups (n=10). CPF was applied in doses of 1/2 and 1/5 of dermal LD50 (E1 and E2) over the tail of mice under occlusive bandages for 3 weeks. Stress control [(s) C] mice were subjected to swim stress at 38 degrees C (6 mins/day, 3 weeks). (s) E1 and (s) E2 were subjected to swim stress before CPF application. Blood and brain AChE levels were estimated using a spectrofluorometric method (Amplex Red). Pyramidal neurons of the cornu ammonis of the hippocampus under Nissl stain from histological sections were counted per unit area of section and analyzed statistically using one way ANOVA. Swim stress at 38 degrees C aggravated reduction of serum AChE by dermal exposure to CPF by 19.7%. Neurons of CA3 and CA1 regions of the hippocampus showed significant reduction in neuronal counts in (s) E1 and (s) E2 groups compared to E1 and E2 groups. Whereas application of CPF 1/2 dermal LD50 (E1) showed significant reduction of neuronal counts only in the CA3 area.
  7. Hussan F, Er HM, Nadarajah VD
    BMC Med Educ, 2024 Nov 22;24(1):1347.
    PMID: 39574101 DOI: 10.1186/s12909-024-06284-3
    BACKGROUND: Learning analytics (LA) is a tool for gathering, analysing, and interpreting data related to student's learning behaviour, engagement, and performance. As the student data collected by the institutions are used to construct LA, it is essential to understand the acceptance and readiness of the students regarding the implementation of LA.

    METHODS: A sequential mixed method research design was used in this study. A validated questionnaire was distributed to undergraduate students of Medicine, Dentistry and Pharmacy programmes to collect their general views on LA. Focus group interviews with a total of 18 students were conducted to explore their perceptions in depth, followed by thematic analysis of the transcribed data.

    RESULTS: Generally, the students were aware of their demographic data, utilisation of learning management system and academic performance data being collected by the university. They were agreeable for collection of those data which had direct association with their learning to be used for LA. However, they expressed concerns about the privacy, confidentiality, and security of the collected data. Three themes emerged from the interviews, i.e., self-regulated learning, evidence-based decision making and data management. The students perceived that LA could help them to monitor achievement of learning outcomes and provide support for individualised learning paths through recommendations of learning resources and learning motivation. They also opined that LA could help educators and institutions by providing feedback on teaching and learning methods, resource allocation and interventions to create conducive learning environment.

    CONCLUSIONS: LA is a useful tool to support self-regulated learning, however, precautions should be exercised during implementation to ensure data privacy and security.

  8. Kok YY, Er HM, Nadarajah VD
    Med Sci Educ, 2021 Dec;31(6):1919-1929.
    PMID: 34518785 DOI: 10.1007/s40670-021-01364-1
    The achievement of learning goals via laboratory practical depends on both extrinsic and intrinsic factors. They could be limited by laboratory time, incurred cost, safety, self-efficacy, inadequate prior preparation by learners, and different learning styles. Hence, virtual laboratory simulation (vLAB) may be an appropriate e-learning tool to overcome these restrictions. In this study, student's perception of the usefulness of vLAB was determined by using deoxyribonucleic acid (DNA) gel electrophoresis and polymerase chain reaction (PCR) as case examples. The perception of Year 2 and 3 health science undergraduate students' (N = 87) was studied using a questionnaire consisting of 12 items, rated on a 5-point Likert-scale. The attainment of learning outcomes was assessed using pre-and post-tests containing multiple-choice questions (MCQs). In addition, student's experience and learning from the vLAB were further explored using qualitative analysis. Although there was no significant difference between the mean scores of the pre-and post-tests, results showed that all participants perceived vLAB well, with a median score of 4 (Agree) for all items in the questionnaire. It provides a meaningful learning experience and an authentic environment where students feel safe to practice what they have learnt in lectures. Moreover, vLAB facilitates individualised learning and enhances self-efficacy among students. In conclusion, vLAB prepares students for physical laboratory sessions by activating the prehension dimension of Kolb's learning cycle, therefore complementing and strengthening the attainments of health sciences laboratory learning goals and outcomes.
  9. Finn GM, Tai J, Nadarajah VD
    Med Educ, 2024 Sep 10.
    PMID: 39255998 DOI: 10.1111/medu.15535
    CONTEXT: In this article, we draw upon diverse and contextually different experiences of working on inclusive assessment, with the aim of bridging and enhancing practices of inclusive assessments for health professions education (HPE) within universities. Instead of juxtaposing our views from three countries, we combine our perspectives to advocate for inclusive assessment.

    DISCUSSION: Creating an inclusive assessment culture is important for equitable education, even if priorities for inclusion might differ between contexts. We recognise challenges in the enactment of inclusive assessment, namely, the notion of lowering standards, harming reliability and robustness of assessment design and inclusion as a poorly defined and catchall term. Importantly, the lack of awareness that inclusion means recognising intersectionality is a barrier for well-designed inclusive assessments. This is why we offer considerations for HPE practitioners that can guide towards a unified direction of travel for inclusive assessments. This article highlights the importance of contextual prioritisation and initiatives to be considered at the global level to national, institutional, programme and the individual level. Utilising experience and literature from undergraduate, higher education contexts, we offer considerations with applicability across the assessment continuum.

    CONTEXT: In this state of science paper, we were set the challenge of providing cross-cultural viewpoints on inclusive assessment. In this discursive article, we focus on inclusive assessment within undergraduate health professions education whilst looking to the wider higher education literature, since institutional policies and procedures frequently drive assessment decisions and influence the environment in which they occur. We explore our experiences of working in inclusive assessment, with the aim of bridging and enhancing practices of inclusive assessments for HPE. Unlike other articles that juxtapose views, we all come from the perspective of supporting inclusive assessment. We begin with a discussion on what inclusive assessment is and then describe our contexts as a basis for understanding differences and broadening conversations. We work in the United Kingdom, Australia and Malaysia, having undertaken research, facilitated workshops and seminars on inclusive assessment nationally and internationally. We recognise our perspectives will differ as a consequence of our global context, institutional culture, individual characteristics and educational experiences. (Note that individual characteristics are also known as protected characteristics in some countries). Then, we outline challenges and opportunities associated with inclusive assessment, drawing on evidence within our contexts, acknowledging that our understanding of inclusive assessment research is limited to publications in English and currently tilted to publications from the Global North. In the final section, we then offer recommendations for championing inclusion, focussing firstly on assessment designs, and then broader considerations to organise collective action. Our article is unapologetically practical; the deliberate divergence from a theoretical piece is with the intent that anyone who reads this paper might enact even one small change progressing towards more inclusive assessment practices within their context.

  10. Krishnan K, Ker JE, Mohammed SM, Nadarajah VD
    J Biomed Sci, 2010;17:86.
    PMID: 21073742 DOI: 10.1186/1423-0127-17-86
    Bacillus thuringiensis (Bt), an ubiquitous gram-positive spore-forming bacterium forms parasporal proteins during the stationary phase of its growth. Recent findings of selective human cancer cell-killing activity in non-insecticidal Bt isolates resulted in a new category of Bt parasporal protein called parasporin. However, little is known about the receptor molecules that bind parasporins and the mechanism of anti-cancer activity. A Malaysian Bt isolate, designated Bt18 produces parasporal protein that exhibit preferential cytotoxic activity for human leukaemic T cells (CEM-SS) but is non-cytotoxic to normal T cells or other cancer cell lines such as human cervical cancer (HeLa), human breast cancer (MCF-7) and colon cancer (HT-29) suggesting properties similar to parasporin. In this study we aim to identify the binding protein for Bt18 in human leukaemic T cells.
  11. Wong RS, Mohamed SM, Nadarajah VD, Tengku IA
    PMID: 20591169 DOI: 10.1186/1756-9966-29-86
    Various strains of Bacillus thuringiensis (Bt) have been found to produce parasporal proteins that are cytotoxic to human cancer cells. This study aims to establish the binding affinity of purified Bt 18 toxin for CEM-SS (T lymphoblastic leukaemia cell line), to determine if competition exists between the toxin and commercial anticancer drugs for the binding site on CEM-SS and to localise the binding site of the toxin on CEM-SS.
  12. Judson JP, Nadarajah VD, Bong YC, Subramaniam K, Sivalingam N
    Med J Malaysia, 2006 Jun;61(2):173-80.
    PMID: 16898308
    Pre-eclampsia or pregnancy induced hypertension (PIH) affects 6-8% of all pregnancies. Although the underlying mechanism of PIH is still unknown, it is widely believed that the placenta plays an important role. It was thought that an ischemic placenta due to poor perfusion can precipitate the signs and symptoms of PIH. This study aims to investigate the possible role of Type 1(AT1) and Type 2 (AT2) angiotensin II receptor subtypes in the mechanism of PIH. AT1 receptor stimulation causes vasoconstriction and AT2 receptor stimulation causes vasodilatation. Investigating the interactions of these two receptors in the placenta provides an insight as to the balance that may exist between AT1 and AT2 receptors in normal pregnancy. Any disruption to the balance might cause a disruption of the blood flow in the placenta, leading to PIH. Placentas were collected from 11 PIH patients and 11 normal patients. Immunohistochemistry techniques were performed on the placental tissue to determine the distribution of AT1 and AT2 receptors in the placental tissue qualitatively and quantitatively. It was observed that in normal patients, the balance between AT1 and AT2 receptors is that the level of AT2 receptors is higher than the level of AT1 receptors. However in the PIH patient, it was observed that the normal balance was disrupted. In PIH patients the level of AT1 receptors was observed to be higher than the level of AT2 receptors. This study suggests that disruption of the balance between AT1 and AT2 receptors observed in PIH placentas might cause a decrease in blood flow to the placenta, causing it to be poorly perfused. This may cause placental ischemia which may lead to PIH.
  13. Thampy HK, Ramani S, McKimm J, Nadarajah VD
    Clin Teach, 2020 Aug;17(4):430-432.
    PMID: 33189096 DOI: 10.1111/tct.13216
  14. Er HM, Nadarajah VD, Ng SH, Wong AN
    Korean J Med Educ, 2020 Sep;32(3):185-195.
    PMID: 32723985 DOI: 10.3946/kjme.2020.166
    PURPOSE: Direct student involvement in quality processes in education has been suggested to encourage shared responsibilities among faculty and students. The objectives of this study were to explore undergraduate health professions students' understanding of quality assurance (QA) in education, and identify the challenges and enablers for student involvement in an Asian context.

    METHODS: Twenty semi-structured interviews were conducted among medical, dentistry, and pharmacy students in a Malaysian University. The interviews were audio-recorded, transcribed verbatim, and thematically analyzed to understand the students' perspectives of QA in education.

    RESULTS: The participants recognized the importance of QA towards ensuring the quality of their training, which will consequently impact their work readiness, employability, and quality of healthcare services. Academic governance, curriculum structure, content and delivery, faculty and student quality, teaching facilities, and learning resources were indicated as the QA areas. The challenges for students' involvement included students' attitude, maturity, and cultural barrier. To enhance their buy-in, clear objectives and impact, efficient QA mechanism, and recognition of students' contribution had been suggested.

    CONCLUSION: The findings of this study support student-faculty partnership in QA processes and decision making.

  15. Ramasamy B, Nadarajah VD, Soong ZK, Lee HL, Mohammad SM
    Trop Biomed, 2008 Apr;25(1):64-74.
    PMID: 18600206
    Vegetative proteins from Malaysian strains of Bacillus thuringiensis israelensis strains (Bt 11, Bt 12, Bt 15, Bt 16, Bt 17, Bt 21 and Bt 22) and Bacillus sphaericus H-25 strains (Bs 1 and Bs 2) were screened for haemolytic, cytotoxic and larvicidal activity. SDS-PAGE profiles of the Bacillus thuringiensis strains studied consistently showed major bands of 33-37 kDa and 47 kDa. Bt 16 also showed two bands of 66 kDa and 45 kDa similar to the previously reported binary vegetative protein, Vip1Ac (66 kDa) and Vip 2Ac (45 kDa). Both the Bacillus sphaericus strains showed a 35 kDa band that was similiar to a previously reported vegetative protein, the Mtx2 protein. Bs 2 also contains a 37 kDa band, similar to another vegetative protein, the Mtx 3 protein. With the exception of Bt 17 and Bt 21, vegetative proteins from all Bacillus thuringiensis and Bacillus sphaericus strains were highly haemolytic to human erythrocytes, causing more than 75% haemolysis at the highest concentration of 200 microg/ml. High haemolytic activity was associated with high cytotoxic activity with most of the haemolytic strains being indiscriminately cytotoxic to both CEM-SS (human T lymphoblastoid) and HeLa (human uterus cervical cancer) cell lines. Interestingly, the less haemolytic vegetative proteins from Bt 17 and Bt 21 demonstrated cytotoxic activity comparable to that of the highly haemolytic vegetative proteins. Bt 21 displayed toxicity towards both cell lines while Bt 17 was more toxic towards CEM-SS cells. Bioassay against Aedes aegypti and Culex quinquefasciatus larvae revealed that vegetative proteins from the Bacillus thuringiensis strains had activity against both species of larvae but vegetative proteins from Bacillus sphaericus were weakly larvicidal towards Cx. quinquefasciatus only.
  16. Chandratilake M, Nadarajah VD, Mohd Sani RMB
    Med Teach, 2021 Jul;43(sup1):S53-S58.
    PMID: 32248710 DOI: 10.1080/0142159X.2020.1741530
    Cultural beliefs and practices impact heavily on health outcomes of patients. Doctors' ability to deal with such issues in clinical practice, i.e. cultural competence, is widely studied in the west. It has yet to be given due importance in non-western contexts. This study aimed to develop a valid and reliable measure of cultural competence in the Malaysian cultural context and to assess cultural competence among Malaysian medical students. Thirty-five cultural issues faced by Malaysian doctors were identified with a series of interviews to develop a preliminary tool. The responses of students to these cultural issues were evaluated against the extent of inquiry and advocacy based on a theoretical framework of cultural competence. The responses were subjected to statistical analysis to determine the internal structure of the tool and to reduce the number of items in the tool. The final tool (IMU Measure of Cultural Competence - IMoCC) comprised of 22 issues, which deemed to be reliable in the second round of testing. In both tools, student cohorts demonstrated an acceptable level of cultural competence with room for improvement. However, they appeared to learn how to deal with cultural issues primarily through informal means and not in the formal curriculum.
  17. Nadarajah VD, Lim VKE, Baba AA
    Med Teach, 2021 Jul;43(sup1):S1-S4.
    PMID: 34190005 DOI: 10.1080/0142159X.2021.1942443
    There have been recent discourses of what scholarship means for health professions education (HPE) and how it may need a rethink during the pandemic. One key take home message from these discourses is the role of institutions in nurturing and investing in scholarship. Given the current challenges faced by both higher education and healthcare, there is a risk that activities and resources for scholarship in HPE may be neglected. How do institutions make a case for continuous investment in HPE scholarship? Despite being a relatively new and small private university with no public funding, IMU has made fairly significant progress in delivering a unique model of HPE programmes with HPE scholarly output. This commentary discusses the importance of investing in scholarship for HPE with the International Medical University (IMU) in Kuala Lumpur, Malaysia as a case study. Examples of institutional initiatives that support and enhance scholarship are presented based on the recent AMEE guide (142) on redefining scholarship.
  18. Assenheimer D, Knox K, Nadarajah VD, Zimitat C
    Educ Health (Abingdon), 2016 May-Aug;29(2):107-12.
    PMID: 27549647 DOI: 10.4103/1357-6283.188748
    BACKGROUND: Epistemological beliefs have a pervasive influence on learning and practice. Understanding these beliefs and how they develop, could play an important role in medical student training and shape later clinical practice.

    METHODS: The epistemological beliefs of first-year medical students from an Australian and Malaysian university were explored using a domain-specific instrument.

    RESULTS: There were significant differences between the disciplinary epistemological beliefs of Australian and Malaysian medical students across many items, and two specific factors (Certainty of Knowledge and Justification for Knowing).

    DISCUSSION: These findings have potential implications for teaching in biomedical disciplines and adaptation of Western curriculum innovations in Eastern educational contexts. Further work is needed to confirm and understand any epistemological differences and subsequent implications for learning and teaching in medicine.
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