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Fulltext Pre and post PBL meetings in ensuring the quality of facilitators in problem based learning

Amirthalingam SD, Ponnudurai G, Chen SY

International e-Journal of Science, Medicine & Education, 2010;4(2):47-53.
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Background: Problem based learning (PBL) is a student-centered curriculum delivery tool believed to promote active student participation. Though the PBL is student-centered, the facilitator plays an important role in maintaining the integrity of this system by providing balance in group interaction and discussion of learning issues. In International Medical University (IMU) one of the strategies to ensure the quality of the facilitators was the pre and post PBL meetings. This study aimed to gauge its usefulness in ensuring the quality of PBL facilitation.
Method: The questionnaire to study the perceptions of PBL facilitators on the pre and post PBL meetings included close ended questions on pre and post PBL meeting’s attendance and their scored opinion in improving PBL facilitation skills, open ended questions inviting suggestions to improve these meetings and PBL facilitation in IMU as a whole and self-evaluation as an effective PBL facilitator using a six point Likert scale to a list of statements.
Results: 84.2% of facilitators agreed the meetings were beneficial. Self-evaluation of their facilitator effectiveness showed on average ratings of seven out of ten indicating strong confidence in facilitating skills. Suggestions ensuring facilitator quality included content expert briefing in pre PBL meetings and student appraisals of facilitators given weightage in staff appraisal.
Conclusion: Pre and post PBL meetings enhanced facilitator comfort with the triggers, adding to their confidence and provided a venue to obtain feedback on the triggers.
Cross-reactivity of monovalent and polyvalent Trimeresurus antivenoms with venoms from various species of Trimeresurus (lance-headed pit viper) snake

Tan NH, Choy SK, Chin KM, Ponnudurai G

Toxicon, 1994 Jul;32(7):849-53.
PMID: 7940592

Trimeresurus bite is a serious medical problem in Asia. However, at present only a few monospecific Trimeresurus antivenoms are available. Investigation of the cross-neutralization capacity of three Trimeresurus antivenoms indicates that the antivenoms exhibit broad cross-reactivity. A polyvalent Trimeresurus antivenom was also found to be effective in neutralization of the haemorrhagic, necrotizing and thrombin-like activities of heterologous Trimeresurus venoms.
Electrophoretic profiles and biological activities: intraspecific variation in the venom of the Malayan pit viper (Calloselasma rhodostoma)

Daltry JC, Ponnudurai G, Shin CK, Tan NH, Thorpe RS, Wüster W

Toxicon, 1996 Jan;34(1):67-79.
PMID: 8835335

The Malayan pit viper (Calloselasma rhodostoma) is of major clinical significance both as a leading cause of snakebite and as the source of ancrod (Arvin). Although its venom has been extensively studied, the degree to which venom composition varies between individuals is poorly known. We individually analysed the venoms of over 100 C. rhodostoma using isoelectric focusing. In all populations, females produced an intense band that was absent from all males, and significant ontogenetic variation was detected. Principal components analysis of the banding profiles also revealed strong geographic variation, which was significantly congruent with variation in the biological activities of the venom (phosphodiesterase, alkalinephosphoesterase, L-amino acid oxidase, arginine ester hydrolase, 5'-nucleotidase, thrombin-like enzyme, haemorrhagic activity). Studies of captive-bred snakes indicate that the intraspecific variation in venom is genetically inherited rather than environmentally induced. The intraspecific variation in venom composition and biological activity could be of applied importance to snakebite therapy, both in correct diagnosis of the source of envenomation and in the development of a more effective antivenom. Greater attention should be given to the source of C. rhodostoma venom used in research to ensure reproducibility of results.
Melatonin inhibits high glucose-induced ox-LDL/LDL expression and apoptosis in human umbilical endothelial cells

Tiong YL, Ng KY, Koh RY, Ponnudurai G, Chye SM

Horm Mol Biol Clin Investig, 2020 Jun 29;41(4).
PMID: 32598308 DOI: 10.1515/hmbci-2020-0009

BACKGROUND: Cardiovascular disease (CVD) is one of the major cause of mortality in diabetic patients. Evidence suggests that hyperglycemia in diabetic patients contributes to increased risk of CVD. This study is to investigate the therapeutic effects of melatonin on glucose-treated human umbilical vein endothelial cells (HUVEC) and provide insights on the underlying mechanisms.
MATERIALS AND METHODS: Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Reactive oxygen species (ROS) and membrane potential was detected using 2',7'-dichlorofluorescein diacetate and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) dye staining, respectively. While, cell apoptosis was determined by Annexin-V staining and protein expression was measured using Western blot.
RESULTS: Our results suggested that melatonin inhibited glucose-induced ROS elevation, mitochondria dysfunction and apoptosis on HUVEC. Melatonin inhibited glucose-induced HUVEC apoptosis via PI3K/Akt signaling pathway. Activation of Akt further activated BcL-2 pathway through upregulation of Mcl-1 expression and downregulation Bax expression in order to inhibit glucose-induced HUVEC apoptosis. Besides that, melatonin promoted downregulation of oxLDL/LOX-1 in order to inhibit glucose-induced HUVEC apoptosis.
CONCLUSIONS: In conclusion, our results suggested that melatonin exerted vasculoprotective effects against glucose-induced apoptosis in HUVEC through PI3K/Akt, Bcl-2 and oxLDL/LOX-1 signaling pathways.
Fulltext A study of the nature and level of trust between patients and healthcare providers, its dimensions and determinants: a scoping review protocol

Rasiah S, Jaafar S, Yusof S, Ponnudurai G, Chung KPY, Amirthalingam SD

BMJ Open, 2020 Jan 23;10(1):e028061.
PMID: 31980505 DOI: 10.1136/bmjopen-2018-028061

INTRODUCTION: The aim of this scoping review is to systematically search the literature to identify the nature and or level of trust between the patient, the users of health services (eg, clients seeking health promotion and preventive healthcare services) and the individual healthcare providers (doctors, nurses and physiotherapists/ occupational therapists), across public and private healthcare sectors, at all levels of care from primary through secondary to tertiary care. It also aims to identify the factors that influence trust between patients, users of health services (clients) and providers of healthcare at all levels of care from primary care to tertiary care, and across all health sectors (public and private). The study will also identify the tools used to measure trust in the healthcare provider.
METHODS AND ANALYSIS: The scoping review will be conducted based on the methodology developed by Arksey and O'Malley's scoping review methodology, and Levac et al 's methodological enhancement. An experienced information specialist (HM) searched the following databases MEDLINE, EMBASE, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature. The search terms were both keywords in the title and/or abstract and subject headings (eg, MeSH, EMTREE) as appropriate. Search results were downloaded, imported and stored into a 'Refworks' folder specifically created for reference management. The preliminary search was conducted between 7 December 2017 and 14 December 2017. Quantitative methods using content analysis will be used to categorise study findings on factors associated with trust between patients, clients and healthcare providers. The collection of studies will be also examined for heterogeneity. Qualitative analysis on peer reviewed articles of qualitative interviews and focus group discussion will be conducted; it allows clear identification of themes arising from the data, facilitating prioritisation, higher order abstraction and theory development. A consultation exercise with stakeholders may be incorporated as a knowledge translation component of the scoping study methodology.
ETHICS AND DISSEMINATION: Ethical approval will be obtained for the research project from the Institutional Review Board. The International Medical University will use the findings of this scoping review research to improve the understanding of trust in healthcare, in its endeavour to improve health services delivery in its healthcare clinics and hospitals, and in its teaching and learning curriculum. The findings will also help faculty make evidence based decisions to focus resources and research as well as help to advance the science in this area. Dissemination of the results of the scoping review will be made through peer-reviewed publications, research reports and presentations at conferences and seminars.
Fulltext Melatonin promotes Schwann cell dedifferentiation and proliferation through the Ras/Raf/ERK and MAPK pathways, and glial cell-derived neurotrophic factor expression

Tiong YL, Ng KY, Koh RY, Ponnudurai G, Chye SM

Exp Ther Med, 2020 Nov;20(5):16.
PMID: 32934681 DOI: 10.3892/etm.2020.9143

Upon peripheral nerve injury (PNI), continuous proliferation of Schwann cells is critical for axon regeneration and tubular reconstruction for nerve regeneration. Melatonin is a hormone that is able to induce proliferation in various cell types. In the present study, the effects of melatonin on promoting Schwann cell proliferation and the molecular mechanism involved were investigated. The present results showed that melatonin enhanced the melatonin receptors (MT1 and MT2) expression in Schwann cells. Melatonin induced Schwann cell dedifferentiation into progenitor-like Schwann cells, as observed by immunofluorescence staining, which showed Sox2 marker expression. In addition, melatonin enhanced Schwann cell proliferation, mediated by the upregulation of glial cell-derived neurotropic factor (GNDF) and protein kinase C (PKC). Furthermore, the Ras/Raf/ERK and MAPK signaling pathways were also involved in Schwann cell dedifferentiation and proliferation. In conclusion, melatonin induced Schwann cell dedifferentiation and proliferation via the Ras/Raf/ERK, MAPK and GDNF/PKC pathways. The present results suggested that melatonin could be used to enhance the recovery of PNI.
Para-phenylenediamine-induces apoptosis via a pathway dependent on PTK-Ras-Raf-JNK activation but independent of the PI3K/Akt pathway in NRK-52E cells

Kasi RA, Moi CS, Kien YW, Yian KR, Chin NW, Yen NK, et al.

Mol Med Rep, 2015 Mar;11(3):2262-8.
PMID: 25411820 DOI: 10.3892/mmr.2014.2979

para‑Phenylenediamine (p‑PD) is a potential carcinogen, and widely used in marketed hair dye formulations. In the present study, the role of the protein tyrosine kinase (PTK)/Ras/Raf/c‑Jun N‑terminal kinase (JNK) and phosphoinositide 3‑kinase (PI3k)/protein kinase B (Akt) pathways on the growth of NRK‑52E cells was investigated. The results demonstrated that p‑PD reduced cell viability in a dose‑dependent manner. The cell death due to apoptosis was confirmed by cell cycle analysis and an Annexin‑V‑fluorescein isothiocyanate binding assay. Subsequent to staining with 2',7'‑dichlorofluorescin diacetate, the treated cells demonstrated a significant increase in reactive oxygen species (ROS) generation compared with the controls. The effects of p‑PD on the signalling pathways were analysed by western blotting. p‑PD‑treated cells exhibited an upregulated phospho‑stress‑activated protein kinase/JNK protein expression level and downregulated Ras and Raf protein expression levels; however, Akt, Bcl‑2, Bcl‑XL and Bad protein expression levels were not significantly altered compared with the control. In conclusion, p‑PD induced apoptosis by a PTK/Ras/Raf/JNK‑dependent pathway and was independent of the PI3K/Akt pathway in NRK‑52E cells.
Cross neutralization of Hypnale hypnale (hump-nosed pit viper) venom by polyvalent and monovalent Malayan pit viper antivenoms in vitro and in a rodent model

Tan CH, Leong PK, Fung SY, Sim SM, Ponnudurai G, Ariaratnam C, et al.

Acta Trop, 2011 Feb;117(2):119-24.
PMID: 21073851 DOI: 10.1016/j.actatropica.2010.11.001

Hypnale hypnale (hump-nosed pit viper) is a medically important venomous snake in Sri Lanka and Southwestern India. Bite of this snake may result in hemostatic dysfunction, acute kidney injury and death. Clinical studies indicated that the locally available polyvalent antivenoms produced in India are not effective against hump-nosed pit viper envenoming. Hence, there is an urgent need to search for effective antivenom. In this paper, we examined the ability of Calloselasma rhodostoma (Malayan pit viper) monovalent antivenom and the Hemato polyvalent antivenom (both produced by Thai Red Cross Society, TRCS) to neutralize the lethality and toxic effects of H. hypnale venom, as C. rhodostoma is considered a sister taxon of H. hypnale. In vitro neutralization studies showed that the Hemato polyvalent antivenom effectively neutralized the lethality of H. hypnale venom (1.52mgvenom/mL antivenom) as well as the hemorrhagic, procoagulant and necrotic activities of the venom. The monovalent C. rhodostoma antivenom could also neutralize the lethality and toxic activities of the venom, but the potency was lower. The Hemato polyvalent antivenom also effectively protected mice from the lethal and local effects of H. hypnale venom in an in vivo rodent model of envenoming. Furthermore, the polyvalent antivenom could also effectively neutralize the venom of Daboia russelii (2.50mgvenom/mL antivenom), another common cause of snake bites in Sri Lanka and South India. These findings suggested that the Hemato polyvalent antivenom may be beneficial in the antivenom treatment of H. hypnale envenoming.