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- PublicationThe effect of CRX-527 on pro-inflammatory cytokine production against mycobacterium bovis BCG clone expressing the c-terminus of merozoite surface protein-1 of plasmodium falciparum(2021-10)Malaria infection is a leading cause of mortality and morbidity in African and Southeast Asian countries. TLR-4 has been shown to be important in malaria immunity and can be possibly use as an adjuvant to enhance the long-lasting immune response against BCG-MSP1C. This research was conducted to determine the effects of toll-like receptor 4 (TLR-4) agonist, CRX527, on cellular and humoral immune response against Mycobacterium bovis bacille Calmette-Guérin (BCG) expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum (BCG-MSP1C). In this study six groups of mice (n=6 per group) were injected with 200 μl intraperitoneal phosphate buffered saline T80 (PBS-T80), 200 μl of PBS-T80 containing 2 x 106 cfu/ml of BCG or rBCG in the presence or absence of CRX527. Blood was collected from the tail veins of the mice before the start of the immunisation and 4 weeks after each immunisation. Enzyme linked immunosorbent assay (ELISA) was carried out to measure the production of TNF-α and IL-12 in the sera of the immunized mice. The findings showed that the sera of rBCG without CRX immunised group yielding the most increase in IL-12 followed by the mice injected with rBCG with CRX. In contrast, the entire mice immunised groups showed decrease production for TNF-α after the immunisation. Therefore, this combination of rBCG with TLR4 agonist can be used to create a vaccine that capable of inducing a strong and long-lasting immunity to allow the immune system to be prepared for the emergence of multidrug-resistant strains of malaria diseases.
- PublicationElucidation of the vasorelaxation mechanisms induced by syzygium polyanthum leaves aqueous extract(2021-08)Previous studies have demonstrated that aqueous extract of Syzygium polyanthum leaves (AESP) has vasorelaxation activity. However, there is still very little information on its mechanism of action on direct vasorelaxation activity. Therefore, the present study was designed to determine endothelium-dependant relaxation of the AESP and investigated the mechanism of vasorelaxation. The in vitro method was utilised, mounting the aortic ring into myograph, precontracted with phenylephrine (1 μM) and studied based on the agonist-antagonist inhibition protocols. The endothelium-dependant was studied on endothelium intact and denuded thoracic arterial ring isolated from Wistar-Kyoto (WKY) rats. The vasorelaxation mechanisms of AESP were evaluated on the endothelial-intact aortic rings. This study shown that the AESP relaxation was endothelium-dependant. The vasorelaxant effect of AESP was attenuated by L-NAME (endothelial nitric oxide synthase/eNOS inhibitor, 100 μM) and ODQ (soluble guanylate cyclase/sGC inhibitor, 10 μM). However, methylene blue (cyclic guanosine monophosphate/cGMP lowering agent, 10 μM) and indomethacin (non-selective COX inhibitor, 10 μM) did not produce significant inhibition on the AESP relaxation. Taken together, the findings indicated that vasorelaxation of AESP was endothelium-dependent, through NO/eNOS and sGC pathways.
- PublicationEvaluation of Hibiscus Sabdariffa L. calyx as cardioprotective agents(2021-10)Cardiovascular diseases (CVD), particularly Myocardial Infarction (MI), are the leading cause of mortality and morbidity worldwide. Hypercholesterolaemia increased the risk of developing CVD. Hibiscus sabdariffa L. (Roselle) has been used traditionally to reduce cholesterol levels. However, there is limited evidence of the plant's cardioprotective effects. The present study evaluated the effects of the aqueous extract of H. sabdariffa calyx (AEHS) on hypercholesterolaemia-myocardial infarction (HC-MI) rats. The proximate analysis was conducted to determine the nutritional composition of a self-made high-cholesterol diet (HCD). There are three phases in the animal study. The first phase (induction phase) was aim to develop an HC rat model using HCD for 6 weeks. The second phase (intervention phase) was to evaluate the effects of 30 days of AEHS treatment on body mass index (BMI), fasting blood sugar (FBS), fasting cholesterol (FC) and systolic blood pressure (SBP) in the rat. The third phase is where isoprenaline induced the myocardial infarction in rats (HC-MI) at day- 29 and 30. Although the cholesterol level was normal in HC-MI rats, there was a fatty change in the liver (steatosis). The HC-MI rat was also established based on raised cardiac troponin T level and the necrotic changes on the left ventricle tissue. However, AEHS did not significantly improve the parameters in the intervention phase. Moreover, AEHS did not reduce the cardiac troponin T significantly compared to the untreated-HC-MI, which is concurrent with the histology of the left ventricle. However, RFT and LFT were normal in AEHS-treated HC-MI. Collectively, further studies are needed to elucidate H. sabdariffa as a cardioprotective agent.
- PublicationDevelopment and optimization of rapid resolution liquid chromatography (RRLC) method following solid-phase extraction for determination of anthocyanin in rat plasma(2021-08)The growing interest of anthocyanins in roselle has brought upon the importance of the compound’s analysis to investigate its pharmacological properties. Sensitive and specific analytical methods are required to accurately analyse the anthocyanin present in the sample. In this study, rapid resolution liquid chromatography (RRLC) was used to analyse cyanidin-3-O-glucoside chloride, one of the anthocyanins found in roselle. Spectrophotometric analysis and optimization of chromatographic conditions were performed to develop a suitable and precise RRLC method for the determination of the selected anthocyanin. Both liquid-liquid extraction (LLE) and solid-phase extraction (SPE) method were performed to evaluate the best extraction method of anthocyanin in the rat plasma sample. The optimised chromatographic method demonstrated that the mobile phase composition of 0.1% trifluoroacetic acid aqueous solution and acetonitrile in the ratio of 81:19, respectively with a flow rate of 0.5 mL/min, at 30°C column temperature and detection wavelength of 525 nm were suitable for RRLC analysis of cyanidin-3-O-glucoside chloride. SPE was chosen as the final extraction method in the study as it produced better peaks in the chromatogram compared to LLE. In conclusion, the developed RRLC method in this study can be used to determine anthocyanins in the future pharmacokinetic study of roselle.
- PublicationEvaluation of the male reproductive toxicity of the anthocyanin-rich standardized extract of hibiscus sabdariffa L.loaded niosomes in sprague dawley rats(2021-08)Hibiscus sabdariffa has long been widely utilised for medicinal purposes. Aqueous extract of H. sabdariffa encapsulated in niosome (AEHS-Nio) was formulated to improve the effectiveness of this plant extract. It was administered to forty male Sprague Dawley rats at four different dosages 0 (control), 250, 500, and 1000 mg/kg/day by oral gavage for 63 days to evaluate the potential effects of AESHNio on the male reproductive system. A substantial number of parameters were evaluated throughout the treatment period that was comprised of three phases; premating, mating, and post-mating. Results obtained demonstrated that the effects of AEHS-Nio on the male rat reproductive system were slightly significant for certain doses. No mortality and any signs of physical toxicity were observed. The mating performance was also not affected. However, due to the established anti-obesity effects of H. sabdariffa extract, the bodyweight of rats were considerably changed. As a consequence, the reproductive organ weights were found to be statistically different. Furthermore, AEHS-Nio increased the testosterone levels and sperm counts of the 250 and 1000 mg/kg dose groups, while the 500 mg/kg dose group showed considerably low levels for both parameters. The 500 mg/kg dose group was detected to exhibit inconsistent data for certain parameters when compared to other groups, which might be caused by confounding factors instead of AEHS-Nio. Therefore, the current data suggest that AEHS-Nio did not toxic to the reproductive system of male rats. Nevertheless, AEHS-Nio should be consumed with caution as long as the dose administered does not exceed 250 mg/kg of bodyweight a day.The human risk on male reproductive parameters associated with its use should also be reasonably estimated.
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- PublicationZinc removal from the industrial wastewater using activated carbon synthesized from mangrove(2021-06-01)Most of wastewater effluent contains dangerous heavy metals that must be appropriately handled. Heavy metal pollution is a serious problem in developing countries, as most industrial operations have increased heavy metal contamination in lakes, rivers, and other water sources. Thus, a substantial amount of research has been performed on low-cost adsorbents to examine their potential in heavy metal removal. As a result, a summary and assessment of mangrove as a low-cost adsorbent have been completed in this report. This study assesses the potential of activated carbon derived from mangroves for the removal of a specific heavy metal, zinc. Aside from that, the examination of the key factors that impact heavy metal removal, which are the effect of temperature, initial concentration, and contact duration on heavy metal removal, is also being examined. The adsorption capacity increased with the increase of initial concentration of Zn2+ from 1 ppm to 7 ppm resulted in an increase in adsorption capacity from 0.1604 mg/g to 1.1627 mg/g. As the temperature raised from 30°C to 60°C, the adsorption capability of Zn2+ were decreased indicating the process was exothermic. The capacity for Zn2+ adsorption reduced from 1.241 mg/g to 1.1627 mg/g as the temperature increased. For adsorption isotherm model, Freundlich isotherm model at temperature of 60°C is more suitable to describe Zn2+ adsorption on mangrove activated carbon due to higher correlation coefficient, R2 value at 0.5984. The correlation coefficient, R2 from the pseudo second order model for Zn2+ adsorption was 0.9959 which is higher than pseudo-first order model, 0.9695. This indicate that pseudo-second order is more suitable more kinetic adsorption model for Zn2+ adsorption.
- ItemThe effects of pre-induction intra venous dexmedetomidine on intraoperative sevoflurane requirement.(Pusat Pengajian Sains Perubatan, 2008)Dexmedetomidine is a highly selective a.2-adrenoreceptor agonist with potent sedative, anaesthetic-sparing and analgesic effects. Due to these effects, it has currently become an important adjuvant to current anaesthetic practi9es. The aim of this study is to evaluate if there is a reduction in the amount of expired fraction of intraoperative sevoflurane used with dexmedetomidine given as a single intravenous (i.v) dose of lJ.Lg/kg, 10 minutes before anaesthetic induction. A prospective, randomized double-blinded clinical trial was conducted on 60 patients planned for minor orthopaedic procedures less than 3 hours of duration. This was done in a time frame of twelve (12) months, between August 2006 and August 2007 at the operation theater of Hospital Universiti Sains Malaysia (HUSM). Sixty patients were randomized to receive either dexmedetomidine (n=30) or normal saline (n=30). Sedation score was evaluated using Ramsey sedation scale during and after drug administration, till patients were induced with fentanyl, sodium thiopentone and rocuronium. Anaesthesia continuation was maintained with 30%: 70% oxygen: nitrous oxide. Amount of sevoflurane administered was adjusted to maintain the bispectral index scale between 40 and 60. The expired fraction of sevoflurane, haemodynamic parameters and analgesia requirement were recorded at 5 minute intervals throughout the intraoperative period. The extubation time, which is the duration taken from the cessation of sevoflurane administration to the time patient is extubated was noted. The postoperative pain score (VAS) was documented at the recovery. Results show that there was a 27.8% reduction in the expired fraction of sevoflurane and a 25% drop ~ the thiopentone requirement in the dexmedetomidine group. The mean heart rate was also significantly lower in the dexmedetomidine compared to normal saline group [mean (CI): 69.20 (64.03, 74.37) versus 82.00 (72.12, 91.87) per minute, p = 0.005]. Patients, who received dexmedetomidine, were observed to be more sedated just before induction when compared to patients who received normal saline. The postoperative pain score (VAS) was significantly lower in the dexmedetomidine compared to normal saline group [mean (SD) 1.507 (0.275) versus 2.209(0.403), p= 0.005].There were no significant differences observed in the demographic characteristics, the mean systolic and diastolic blood pressure measurements and the extubation time between the two groups. In conclusio~ preoperative administration of a single dose intravenous dexmedetomidine decreased the expired fraction of sevoflurane by 27.8% in minor orthopaedic surgeries and has proven to be a good anaesthetic adjuvant as it not only blunts the haemodynamic response to intubation but also reduces the postoperative opioid requirement. Patients were noted to be. more comfortable, alert and complained of less pain during the postoperative period
- ItemPersepsi kaum Tionghoa dan peribumi terhadap interaksi komunikasi antara budaya di Sumatera Utara : Satu kajian kes di bandar Medan.(Universiti Sains Malaysia, 2011-01)Permasalahan kajian ialah faktor-faktor yang mempengaruhi persepsi budaya kaum Tionghoa dan peribumi terhadap interaksi komunikasi antara budaya di Indonesia, khasnya di bandar Medan Negeri Sumatera Utara. The researcher hoped to examine factors that influence the perceptions of the Chinese and the natives towards intercultural communication in Indonesia, especially in Medan, a city in Northern Sumatera.
- PublicationLocal Government Administration And Rural Transformation In Nasarawa State, Nigeria(2023-08)There is an interface that exists between government at the rural or grass root level and rural transformation or development which is the main reason why Local Government Administrations were established all over the world. This research work seeks to examine the role of Local Government Administrations in Rural Development in Nasarawa State, Nigeria, with a particular focus on three key variables of rural development which are: Agriculture, Health and Education. The main objectives of this study are (i) to examine the extent to which Local Government Administrations in Nasarawa state have contributed to Rural Development in terms of Agriculture, Health and Education, (ii) to investigate the factors responsible for the underdevelopment of the rural areas in Nasarawa state in terms of Agriculture, Health and Education, (iii) to suggest the ways forward on how the rural areas of Nasarawa state can be better developed. The study employed the qualitative research method, where an in- depth interview was conducted. The data were coded and analyzed using the thematic analysis with the help of Nvivo 12 software. The findings in the study reveal that local government administrations in Nasarawa state have failed to deliver on their mandate of developing the rural areas as expected of them, most especially in the areas of Agriculture, Health and Education. The study therefore recommends that the Local Government Administrations in the state should do their best by ensuring good service delivery in the rural areas in terms of Agriculture, Health, and Education.
- ItemIntegrated Approach For Improving Product Design(2002-01)Assembly is one of the most important stages of product development. Design for assembly (DF A) is a recent approach towards improving product designs for easier and less costly assembly operations. The main objective of the research work is to develop an improved DFA system. The system is supposed to support new techniques for design for assembly and to provide users opportunity to assess and reduce the total production cost by means of reducing assembly time and cost at the early stage of the design process. The system is expected to enable designers to minimize the number of components of a product without compromising the product functions. To accomplish such a crucial task, two most current DF A methodologies are reviewed in the current research work towards developing a framework for design for assemblability analysis. The scope of the work includes systematizing the assemblability analysis for a product through generic sequence of design activities with rational basis. The inherent knowledge of the DF A rules and principles are· used in a systematic way throughout the assemblability analysis. The software 'PROPT' has been developed in this research work for the convenience of the designers. The software could facilitate quick result with best accuracy to be obtained and to preserve the design data for future reference. Two case studies have been performed using the software to illustrate the proposed method with a view to determine its effectiveness in actual application.