Displaying publications 21 - 40 of 61 in total

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  1. Azizi MMF, Lau HY, Abu-Bakar N
    J Biosci, 2021;46.
    PMID: 34544910
    Identification of plant variety and cultivar is pivotal in the agricultural sector due to the abundance of plant varieties and cultivars developed in many crop species. However, plant variety and cultivar identification via basic morphological features is problematic and challenging when differentiating closely related species not only due to their limited differences but also due to technical limitations of the process being time-consuming, labour-intensive and costly, and statistically imprecise information being available due to phenotypic plasticity. Therefore, it is imperative to have rapid and highly efficient techniques to mitigate these limitations. This review provides an overview and summarization of the development and application of molecular markers such as Random Amplified Polymorphic DNA (RAPD), Restriction Fragment Length Polymorphism (RFLP), Simple Sequence Repeats (SSR), Inter-simple sequence repeats (ISSR), Amplified Fragment Length Polymorphism (AFLP), Single nucleotide polymorphism (SNP) and DNA barcoding, High-resolution melting (HRM) and biosensor technology as potential tools in the identification of plant variety and cultivar.
  2. Siew WY, Abu Bakar NHH, Abu Bakar M, Zainal Abidin A
    J Hazard Mater, 2021 Aug 15;416:125846.
    PMID: 34492799 DOI: 10.1016/j.jhazmat.2021.125846
    The incorporation of different percentages of Fe2+ into copper benzene-1,3,5-tricarboxylate (CuBTC) was successfully carried out at room-temperature synthesis with water as the only solvent. The XRD and XPS analysis shows that the Fe2+ were substituted into the paddlewheel structure. The incorporation of 18% Fe2+ into CuBTC can increase the surface area and porosity of the framework. The BET surface area of Cu82Fe18BTC (1240 m2/g) was significantly higher than CuBTC (708 m2/g). Further increase in the Fe2+ percentage will reduce the surface area of the compound. The presence of Fe2+ in the framework successfully disturbs the pore formation and widens the pore size on the surface of these compounds. This as well as the pHpzc, which is related to the surface acidity of the resulting bimetallic organic framework (BMOF), play an important role in the adsorption process. Cu53Fe47BTC with an adsorption capacity of 94.42 mg/g shows approximately 6 times greater adsorption capacity against MB compared to CuBTC. This shows that by utilizing a different ratio of Cu and a second metal, it is possible to effectively design the surface morphology of BMOF for specific applications.
  3. Mohd Fahmi MSA, Swain P, Ramli AH, Wan Ibrahim WN, Saleh Hodin NA, Abu Bakar N, et al.
    Heliyon, 2023 Feb;9(2):e13685.
    PMID: 36852036 DOI: 10.1016/j.heliyon.2023.e13685
    Epilepsy is the third most common known brain disease worldwide. Several antiepileptic drugs (AEDs) are available to improve seizure control. However, the associated side effects limit their practical use and highlight the ongoing search for safer and effective AEDs. Eighteen newly designed fluorine-containing pyrrolylated chalcones were extensively studied in silico, synthesized, structurally analyzed by X-ray diffraction (XRD), and biologically and toxicologically tested as potential new AEDs in zebrafish epilepsy in vivo models. The results predicted that 3-(3,5-difluorophenyl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (compound 8) had a good drug-like profile with binding affinity to γ-aminobutyric acid receptor type-A (GABAA, -8.0 kcal/mol). This predicted active compound 8 was effective in reducing convulsive behaviour in pentylenetetrazol (PTZ)-induced larvae and hyperactive movements in zc4h2 knockout (KO) zebrafish, experimentally. Moreover, no cardiotoxic effect of compound 8 was observed in zebrafish. Overall, pyrrolylated chalcones could serve as alternative AEDs and warrant further in-depth pharmacological studies to uncover their mechanism of action.
  4. Zin NNINM, Mohamad MN, Roslan K, Abdul Wafi S, Abdul Moin NI, Alias A, et al.
    Malays J Med Sci, 2020 Jul;27(4):36-50.
    PMID: 32863744 MyJurnal DOI: 10.21315/mjms2020.27.4.4
    BACKGROUND: The spread of Plasmodium falciparum resistance in common antimalarial drugs, including artemisinin-based combination therapies, has necessitated the discovery of new drugs with novel mechanisms of action. In the present study, the in vitro antimalarial and toxicological activities of acetone, methanol, ethanol and aqueous extracts of Quercus infectoria (Q. infectoria) galls were investigated.

    METHODS: The extracts were assessed for the antimalarial potential using a malarial SYBR Green I fluorescence-based (MSF) assay, while the toxicity was screened by using brine shrimp lethality test (BSLT), haemolytic assay, and cytotoxicity assay against normal embryo fibroblast cell line (NIH/3T3) and normal kidney epithelial cell line (Vero).

    RESULTS: The acetone extract showed the highest antimalarial activity (50% inhibitory concentration, IC50 = 5.85 ± 1.64 μg/mL), followed by the methanol extract (IC50 = 10.31 ± 1.90 μg/mL). Meanwhile, the ethanol and aqueous extracts displayed low antimalarial activity with IC50 values of 20.00 ± 1.57 and 30.95 μg/mL ± 1.27 μg/mL, respectively. The significant antimalarial activity was demonstrated in all extracts and artemisinin (P < 0.05). All extracts were non-toxic to brine shrimps (50% lethality concentration, LC50 > 1000 ppm). Furthermore, no occurrence of haemolysis (< 5%) was observed in normal erythrocytes when treated with all extracts compared to Triton X-100 that caused 100% haemolysis (P < 0.05). The acetone and methanol extracts were non-toxic to the normal cell lines and statistically significant to artemisinin (P < 0.05).

    CONCLUSION: Taken together with satisfactory selectivity index (SI) values, the acetone and methanol extracts of Q. infectoria galls could serve as an alternative, promising and safe antimalarial agents.

  5. Abu Bakar N, Abdul Aziz YF, Singh Sandhu R, Fadzli F, Yaakub NA, Krishnasamy S, et al.
    Heart Lung Circ, 2013 Apr;22(4):305-8.
    PMID: 22921797 DOI: 10.1016/j.hlc.2012.07.016
    Pericardial cysts are uncommon mediastinal lesions that are usually congenital in origin. Patients are usually asymptomatic and the cysts are generally discovered on routine radiography for unrelated purposes. This case illustrates a symptomatic presentation of a haemorrhagic pericardial cyst in which radiographic, echocardiographic and multislice (MRI and CT) imaging were performed. The imaging findings were not typical of pericardial cysts leading to a diagnostic quandary despite the varied imaging techniques. In conclusion, it is important to appreciate that the imaging findings of pericardial cysts can be varied. Radiologists and clinicians alike should be aware of this variability.
  6. Abu Bakar N, Lee CL
    Med J Malaysia, 2013;68(1):73-5.
    PMID: 23466774
    Osteo-odontokeratoprosthesis (OOKP) surgery is a technique used to replace damaged cornea in blind patients for whom cadaveric transplantation is not feasible. OOKP surgery is a complex procedure requiring lifetime follow-up. The preservation of the osteo-odontolamina is the vital feature in maintaining the stability of the OOKP. Early detection of lamina resorption enables early prophylactic measures to be taken and prevent resorption-related complications. This case illustrates the radiological findings of the first OOKP surgery in Malaysia and the role of multidetector computed tomography (MDCT) in postoperative management of OOKP surgery.
  7. Junjia Y, Alias AH, Haron NA, Abu Bakar N
    Heliyon, 2024 Jan 15;10(1):e23587.
    PMID: 38192814 DOI: 10.1016/j.heliyon.2023.e23587
    Hoisting is an essential aspect of Industrial Building System (IBS) construction. Although research on hoisting safety in China has made strides to focus on "worker," "data," "task," "site," and "accident," there still needs to be more approaches based on multi-dimensional social system thinking. Therefore, the paper aims to fill this gap. We investigated 105 hoisting accidents in China and found that hoisting accidents occurred most frequently in China's southeast coastal region; truck-mounted cranes and tower cranes were the most common types of machinery involved in accidents; hoisting load off, capsizing of crane machinery, and workers falling from height are the three most common accident types; the average impact of a single hoisting accident is approximately RMB 2.43 million direct economic loss, 1.543 deaths and 0.829 injured. This study used three algorithms (Rindge regression, Lasson regression, and partial least squares regression) to explore the impact of deaths and injuries on direct economic losses. By combining Rasmussen's risk framework with the characteristics of hoisting construction, six risk domains and thirty-six safety risk factors were identified. Finally, we used AcciMap technology to construct a qualitative IBS hoisting management model, which exhaustively presents the systematic levels and propagation paths of the influencing factors by the PDCA method. The research helps academics explore strategies to improve the safety of hoisting construction in IBS. Moreover, the study outcomes can inform the policy-making process towards promoting healthy and sustainable construction development.
  8. Mohamed-Yassin MS, Baharudin N, Daher AM, Abu Bakar N, Ramli AS, Abdul-Razak S, et al.
    BMC Cardiovasc Disord, 2021 03 23;21(1):149.
    PMID: 33757445 DOI: 10.1186/s12872-021-01956-0
    BACKGROUND: Dyslipidaemia refers to lipid abnormalities consisting of either one or any combination of the following: elevated total cholesterol (TC), elevated low-density lipoprotein cholesterol (LDL-c), elevated triglycerides (TG), and low high-density lipoprotein cholesterol (HDL-c). The prevalence of hypercholesterolaemia is steadily increasing in Malaysia. However, data on the prevalence of dyslipidaemia subtypes among Malaysians are lacking. This is important as it may have implications for preventive and management strategies for this increasing public health challenge. This study is aimed at determining the prevalence of dyslipidaemia subtypes and their associated personal and clinical attributes in Malaysians.

    METHODS: REDISCOVER, a prospective study, enrolled 11,288 adults where sociodemographic data, anthropometric and blood pressure measurements, fasting lipid profile and glucose, and history of diabetes, hypertension, and smoking were obtained. The cross-sectional analytic sample presented in this article comprised 10,482 participants from baseline recruitment. The data was analysed by descriptive statistics and multivariable logistic regression.

    RESULTS: The overall prevalence of elevated TC, elevated LDL-c, elevated TG, low HDL-c, and elevated non-HDL-c were 64.0% (95% CI 63.0-65.0), 56.7% (CI 55.7-57.7), 37.4% (CI 36.5-38.4), 36.2% (CI 35.2-37.1), and 56.2% (CI 55.3-57.2), respectively. Overweight, obesity, and central obesity were highly prevalent and significantly associated with elevated TC and all dyslipidaemia subtypes. Older age was associated with elevated TC, elevated LDL-c and elevated non-HDL-c. Hypertension was associated with elevated TC, elevated TG, and elevated non-HDL-c, while diabetes was associated with elevated TG and low HDL-c.

    CONCLUSIONS: Elevated TC and all dyslipidaemia subtypes are highly prevalent in Malaysia where increased body mass seems the main driver. Differences in the prevalence and associated personal and clinical attributes may facilitate specific preventive and management strategies.

  9. Abu Bakar N, Lau BYC, González-Aravena M, Smykla J, Krzewicka B, Karsani SA, et al.
    Microb Ecol, 2023 Dec 07;87(1):11.
    PMID: 38060022 DOI: 10.1007/s00248-023-02311-w
    In understanding stress response mechanisms in fungi, cold stress has received less attention than heat stress. However, cold stress has shown its importance in various research fields. The following study examined the cold stress response of six Pseudogymnoascus spp. isolated from various biogeographical regions through a proteomic approach. In total, 2541 proteins were identified with high confidence. Gene Ontology enrichment analysis showed diversity in the cold stress response pathways for all six Pseudogymnoascus spp. isolates, with metabolic and translation-related processes being prominent in most isolates. 25.6% of the proteins with an increase in relative abundance were increased by more than 3.0-fold. There was no link between the geographical origin of the isolates and the cold stress response of Pseudogymnoascus spp. However, one Antarctic isolate, sp3, showed a distinctive cold stress response profile involving increased flavin/riboflavin biosynthesis and methane metabolism. This Antarctic isolate (sp3) was also the only one that showed decreased phospholipid metabolism in cold stress conditions. This work will improve our understanding of the mechanisms of cold stress response and adaptation in psychrotolerant soil microfungi, with specific attention to the fungal genus Pseudogymnoascus.
  10. Abu Bakar N', Hakim Abdullah MN, Lim V, Yong YK
    PMID: 35069762 DOI: 10.1155/2022/6098929
    Peptic ulcer disease is a multifactorial disorder and is the most significant public health concern nowadays. Previous study showed that essential oil extracted from Momordica charantia's seed exhibited gastroprotective effect. However, the evidence for the gastroprotective effect of its active compound, polypeptide K (PPK), remains unclear. This study aimed to examine the preventive effect of PPK against different experimental gastric lesions models in rats. The possible gastroprotective effect of PPK was assessed in hydrochloride ethanol- and indomethacin-induced gastric ulcer models in Sprague Dawley rats and was further evaluated macroscopically and microscopically. Pyloric ligation experiments were used to investigate gastric secretion. Oral administration of PPK at all concentrations (10, 25, and 50 mg/kg) showed significant (p < 0.05) reduction in total area of lesion in both hydrochloride ethanol- and indomethacin-induced gastric ulcer models. The highest inhibition rate was seen in PPK dose of 50 mg/kg with 64.9% and 72.2% on hydrochloride ethanol and indomethacin models, respectively. Microscopically, PPK preserved the normal architectures of the gastric tissues from being damaged by hydrochloride ethanol and indomethacin. Further, in the pyloric ligation studies, PPK significantly (p < 0.05) decreased the ulcer area where the highest protection was exhibited by 50 mg/kg with 70% inhibition rate. Moreover, all concentrations of PPK also significantly (p < 0.05) enhanced the gastric wall mucus secretion. Collectively, this study demonstrated the gastroprotective effect of PPK on hydrochloride ethanol- and indomethacin-induced gastric ulcer models. The possible mechanism might be associated with enhanced mucus secretion and thus lowering the total acidity.
  11. Abu Bakar N, Karsani SA, Alias SA
    PeerJ, 2020;8:e10423.
    PMID: 33362961 DOI: 10.7717/peerj.10423
    BACKGROUND: Increases in knowledge of climate change generally, and its impact on agricultural industries specifically, have led to a greater research effort aimed at improving understanding of the role of fungi in various fields. Fungi play a key role in soil ecosystems as the primary agent of decomposition, recycling of organic nutrients. Fungi also include important pathogens of plants, insects, bacteria, domestic animals and humans, thus highlighting their importance in many contexts. Temperature directly affects fungal growth and protein dynamics, which ultimately will cascade through to affect crop performance. To study changes in the global protein complement of fungi, proteomic approaches have been used to examine links between temperature stress and fungal proteomic profiles.

    SURVEY METHODOLOGY AND OBJECTIVES: A traditional rather than a systematic review approach was taken to focus on fungal responses to temperature stress elucidated using proteomic approaches. The effects of temperature stress on fungal metabolic pathways and, in particular, heat shock proteins (HSPs) are discussed. The objective of this review is to provide an overview of the effects of temperature stress on fungal proteomes.

    CONCLUDING REMARKS: Elucidating fungal proteomic response under temperature stress is useful in the context of increasing understanding of fungal sensitivity and resilience to the challenges posed by contemporary climate change processes. Although useful, a more thorough work is needed such as combining data from multiple -omics platforms in order to develop deeper understanding of the factor influencing and controlling cell physiology. This information can be beneficial to identify potential biomarkers for monitoring environmental changes in soil, including the agricultural ecosystems vital to human society and economy.

  12. Lim SG, Phyo WW, Shah SR, Win KM, Hamid S, Piratvisuth T, et al.
    J Viral Hepat, 2018 12;25(12):1533-1542.
    PMID: 30141214 DOI: 10.1111/jvh.12989
    There is a paucity of information on chronic hepatitis C (CHC) patients treated with direct antiviral agents (DAAs) in Asia. We invited Asia-Pacific physicians to collate databases of patients enrolled for CHC treatment, recording baseline clinical, virologic and biochemical characteristics, sustained virologic response at week 12 (SVR12) and virologic failure. SVR12 outcome was based on intention to treat (ITT). Multivariate analysis was used to assess independent risk factors for SVR12 using SPSS version 20. A total of 2171 patients from India (n = 977), Myanmar (n = 552), Pakistan (n = 406), Thailand (n = 139), Singapore (n = 72) and Malaysia (n = 25) were collected. At baseline, mean age was 49 years, 50.2% were males, and 41.8% had cirrhosis. Overall, SVR12 was 89.5% and by genotype (GT) based on ITT and treatment completion, respectively, was 91% and 92% for GT1, 100% and 100% for GT2, 91% and 97% for GT3, 64% and 95% for GT4, 87% and 87% for GT6 and 79% and 91% for GT untested. Patients with cirrhosis had SVR12 of 85% vs 93% for noncirrhosis (P < 0.001) (RR 2.1, 95% CI 1.4-3.1, P = 0.0002). Patients with GT1 and GT3 treated with sofosbuvir/ribavirin (SR) had 88% and 89% SVR12, respectively, but those GT6 treated with sofosbuvir/ledipasvir (SL) had only 77.6% SVR12. Multivariate analysis showed absence of cirrhosis was associated with higher SVR12 (OR 2.0, 95% CI 1.3-3.1, P = 0.002). In conclusion, patients with GT1 and GT3 with/without cirrhosis had surprisingly high efficacy using SR, suggesting that Asians may respond better to some DAAs. However, poor GT6 response to SL suggests this regimen is suboptimal for this genotype.
  13. Abu Bakar N, Mohd Sata NS, Ramlan NF, Wan Ibrahim WN, Zulkifli SZ, Che Abdullah CA, et al.
    Neurotoxicol Teratol, 2017 Jan-Feb;59:53-61.
    PMID: 27919701 DOI: 10.1016/j.ntt.2016.11.008
    Chronic exposure to mercury (Hg) can lead to cumulative impairments in motor and cognitive functions including alteration in anxiety responses. Although several risk factors have been identified in recent year, little is known about the environmental factors that either due exposure toward low level of inorganic mercury that may led to the developmental disorders. The present study investigated the effects of embryonic exposure of mercury chloride on motor function and anxiety-like behavior. The embryo exposed to 6 different concentrations of HgCl2 (7.5, 15, 30, 100, 125, 250nM) at 5hpf until hatching (72hpf) in a semi-static condition. The mortality rate increased in a dose dependent manner where the chronic embryonic exposure to 100nM decreased the number of tail coiling, heartbeat, and swimming activity. Aversive stimulus was used to examine the effects of 100nM interferes with the development of anxiety-related behavior. No elevation in both thigmotaxis and avoidance response of 6dpf larvae exposed with 100nM were found. Biochemical analysis showed HgCl2 exposure affects proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. These results showed that implication of HgCl2 on locomotor and biochemical defects affects motor performance and anxiety-like responses. Yet, the potential underlying mechanisms these responses need to be further investigated which is crucial to prevent potential hazards on the developing organism due to neurotoxicant exposure.
  14. Siva Dharma D, Abu Bakar N, Mustafa BE
    Eur J Dent, 2021 Oct;15(4):647-652.
    PMID: 34428845 DOI: 10.1055/s-0041-1727552
    OBJECTIVE: The aim of this study was to assess and compare the salivary leptin hormone levels between different classes of facial skeletal pattern (Class I, II, and III).

    MATERIALS AND METHODS: A sample of 62 patients were selected prior to the orthodontic treatment from a population that attended the International Islamic University Malaysia Specialist Orthodontic Clinic. Based on the lateral cephalometric analysis, the subjects were grouped into Class I, Class II, and Class III facial skeletal patterns, according to Eastman and Wits appraisal. Subsequently, unstimulated saliva samples were taken and purified to undergo leptin enzyme-linked immunosorbent assay analysis to determine the levels of leptin hormone. Statistical analysis using the Kruskal-Wallis test was used to analyze the data obtained.

    RESULTS: The results showed that there was a significant difference between the levels of leptin hormone between Class I and Class II skeletal patterns and between Class I and Class III facial skeletal patterns. No statistical difference was noted between the levels of leptin of Class II and Class III facial skeletal patterns.

    CONCLUSION: Salivary leptin hormone levels are higher in patients with Class II and Class III facial skeletal patterns compared with Class I.

  15. Abu Bakar N', Hakim Abdullah MN, Lim V, Yong YK
    PMID: 33976701 DOI: 10.1155/2021/5525584
    Momordica charantia (MC) is popular for its medicinal uses especially for treating diabetic-related complications. However, the antiulcer activity of essential oil derived from the seeds has not been systematically studied. This study aims to evaluate the gastroprotective activities of essential oil derived from the seed of MC induced by hydrochloride acid/ethanol (HCl/EtOH) and indomethacin and pylorus-ligation model. Gastric ulceration was induced by oral administration of HCl/EtOH solution or indomethacin on day 7 after animals have been pretreated with testing compounds. The first group received just distilled water and the second group received ranitidine (100 mg/kg). Groups 3, 4, and 5 received 10, 50, and 100 mg/kg of essential oil based on their body weight (10 mL/kg), respectively. Macroscopically, pretreatment of essential oil extracted from MC significantly decreased ulceration induced by HCl/EtOH and indomethacin in vivo. Microscopically, essential oil also significantly suppressed the formation of edema, epithelial disruption, and mucosa erosions. Moreover, essential oil significantly elevated the pH without decreasing the total acidity of the gastric juice and was able to increase the amount of adherent mucus compared to control. Current results provide scientific basis to the ethno-pharmacological usage of the MC in preventing ulcer formation induced by HCl/EtOH and indomethacin.
  16. Abu Bakar N, Wan Ibrahim WN, Zulkiflli AR, Saleh Hodin NA, Kim TY, Ling YS, et al.
    Ecotoxicol Environ Saf, 2023 May;256:114862.
    PMID: 37004432 DOI: 10.1016/j.ecoenv.2023.114862
    The widespread presence of mercury, a heavy metal found in the environment and used in numerous industries and domestic, raises concerns about its potential impact on human health. Nevertheless, the adverse effects of this environmental toxicant at low concentrations are often underestimated. There are emerging studies showing that accumulation of mercury in the eye may contribute to visual impairment and a comorbidity between autism spectrum disorders (ASD) trait and visual impairment. However, the underlying mechanism of visual impairment in humans and rodents is challenging. In response to this issue, zebrafish larvae with a cone-dominated retinal visual system were exposed to 100 nM mercury chloride (HgCl2), according to our previous study, followed by light-dark stimulation, a social assay, and color preference to examine the functionality of the visual system in relation to ASD-like behavior. Exposure of embryos to HgCl2 from gastrulation to hatching increased locomotor activity in the dark, reduced shoaling and exploratory behavior, and impaired color preference. Defects in microridges as the first barrier may serve as primary tools for HgCl2 toxicity affecting vision. Depletion of polyunsaturated fatty acids (PUFAs), linoleic acid, arachidonic acid (ARA), alpha-linoleic acid, docosahexaenoic acid (DHA), stearic acid, L-phenylalanine, isoleucine, L-lysine, and N-acetylputrescine, along with the increase of gamma-aminobutyric acid (GABA), sphingosine-1-phosphate, and citrulline assayed by liquid chromatography-mass spectrometry (LC-MS) suggest that these metabolites serve as biomarkers of retinal impairments that affect vision and behavior. Although suppression of adsl, shank3a, tsc1b, and nrxn1a gene expression was observed, among these tsc1b showed more positive correlation with ASD. Collectively, these results contribute new insights into the possible mechanism of mercury toxicity give rise to visual, cognitive, and social deficits in zebrafish.
  17. Boon, Y. T., Naim, M. N., Zakaria, R., Abu Bakar, N. F., Ahmad, N.
    MyJurnal
    A study on the feasibility of using gel electrophoresis technique in grading the agarwood oil
    quality was investigated. Prior to electrophoresis, the emulsified agarwood oil droplets were
    screened by a diffuse layer of ions that have equal absolute charge to that of the droplets surface
    charge in aqueous phase. The condition was obtained by varying the concentrations of nonionic
    surfactant; Tween 80 until the critical aggregation concentration (CAC) value of 0.0167%
    (v/v) was achieved. The prepared droplets suspended in the aqueous within nano-metre size and
    had ability to migrate through the agarose gel with its own specific electrophoretic mobility.
    However, due to the limitation of gel pore size, only large oil droplets (>200 nm) indicated
    visible bands. Overall, a novel work for grading the emulsified agarwood oil droplet with its
    own electrical properties was feasible.
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