Displaying publications 1 - 20 of 218 in total

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  1. Abdullah JM, Zhang J
    Mini Rev Med Chem, 2013 Apr 01;13(5):744-8.
    PMID: 23373649
    The γ-aminobutyric acid (GABA) A receptor is composed of a variety of subunits and combinations and shows a characteristic distribution in the CNS. To date, 20 subunits of the GABA A receptor have been cloned: α1-6, β1-4, γ1-3, δ, π, ε , Θ, and ρ1-3. Oocyte of Xenopus laevis is one of the most frequently used heterologous expression systems, which are used to design and analyze specific combinations of GABA A receptor subunits. In oocytes, a certain GABA A receptor function is studied only by comparing the amplitude of the response to GABA and other drugs by physiological and pharmacological methods. According to the studies on Xenopus laevis oocytes, the α1β2γ2S receptor combination is mostly used. The α1-containing receptors mediate sedative and anticonvulsant acts. The results of studies on oocytes show that PKA, NKCC1, P2X3 receptors, and GABA A receptor-associated protein, etc., are existing systems that show different reactivity to the GABA A receptors. The GABA A receptor subunits contain distinct binding sites for BZDs, neurosteroids, general anesthetics, etc., which are responsible for the numerous functions of the GABA A receptor. A variety of other drugs, such as topiramate, TG41, (+)- and (-)-borneol, apigenin, and 6-methylflavone could also have modulatory effects on the GABA A receptors. Some of the different models and hypotheses on GABA A receptor structure and function have been achieved by using the two-electrode voltage clamp method in oocytes.
  2. Othman A, Idris Z, Rosman AK, Abdullah JM, GhanI ARI, Zakaria AZ
    Malays J Med Sci, 2022 Oct;29(5):48-58.
    PMID: 36474530 DOI: 10.21315/mjms2022.29.5.6
    BACKGROUND: Cognitive impairment (CI) and neuropsychiatry manifestation (NM) are known complications among patients with traumatic brain injury (TBI). However, the clinical correlation between mild and moderate TBI with the above have not been extensively studied.

    METHODS: The patients (n = 54) were divided into mild and moderate TBI. Both groups were assessed at 3 months and 6 months post-trauma for the same measures. Diagnosis of CI was done using the Montreal cognitive assessment (MoCA) questionnaire while NM screening was performed using the 12-items General Health Questionnaire (GHQ-12) followed by MINI International Neuropsychiatry Interview (MINI).

    RESULTS: We found five patients (19.2%) with mild TBI had CI and five patients (19.2%) had NM at 3 months. Only one patient (3.8%) persistently has CI at 6 months while the rest recovered. As for moderate TBI, 11 patients (39.3%) had CI and seven patients (25%) had NM at 3 months but none had persistent CI or NM at 6 months. Age (P < 0.05) and blood pressure were significant risks (P < 0.05) for CI and NM at 3 months.

    CONCLUSION: This study highlighted the importance of screening following mild and moderate TBI at 3 months and 6 months. Early recognition facilitates effective rehabilitation programmes planning hence improve prognosis in the future.

  3. Muthuraju S, Islam MR, Pati S, Jaafar H, Abdullah JM, Yusoff KM
    Int J Neurosci, 2015;125(9):686-92.
    PMID: 25180987 DOI: 10.3109/00207454.2014.961065
    Dopamine (DA) is one of the key neurotransmitters in the striatum, which is functionally important for a variety of cognitive and motor behaviours. It is known that the striatum is vulnerable to damage from traumatic brain injury (TBI). However, a therapeutic approach has not yet been established to treat TBI. Hence, the present work aimed to evaluate the ability of Normobaric hyperoxia treatment (NBOT) to recover dopaminergic neurons following a fluid percussion injury (FPI) as a TBI experimental animal model. To examine this, mice were divided into four groups: (i) Control, (ii) Sham, (iii) FPI and (iv) FPI+NBOT. Mice were anesthetized and surgically prepared for FPI in the striatum and immediate exposure to NBOT at various time points (3, 6, 12 and 24 h). Dopamine levels were then estimated post injury by utilizing a commercially available ELISA method specific to DA. We found that DA levels were significantly reduced at 3 h, but there was no reduction at 6, 12 and 24 h in FPI groups when compared to the control and sham groups. Subjects receiving NBOT showed consistent increased DA levels at each time point when compared with Sham and FPI groups. These results suggest that FPI may alter DA levels at the early post-TBI stages but not in later stages. While DA levels increased in 6, 12 and 24 h in the FPI groups, NBOT could be used to accelerate the prevention of early dopaminergic neuronal damage following FPI injury and improve DA levels consistently.
  4. Haris K, Ismail S, Idris Z, Abdullah JM, Yusoff AA
    Asian Pac J Cancer Prev, 2014;15(11):4499-505.
    PMID: 24969876
    Glioblastoma, the most aggressive and malignant form of glioma, appears to be resistant to various chemotherapeutic agents. Hence, approaches have been intensively investigated to targeti specific molecular pathways involved in glioblastoma development and progression. Aloe emodin is believed to modulate the expression of several genes in cancer cells. We aimed to understand the molecular mechanisms underlying the therapeutic effect of Aloe emodin on gene expression profiles in the human U87 glioblastoma cell line utilizing microarray technology. The gene expression analysis revealed that a total of 8,226 gene alterations out of 28,869 genes were detected after treatment with 58.6 μg/ml for 24 hours. Out of this total, 34 genes demonstrated statistically significant change (p<0.05) ranging from 1.07 to 1.87 fold. The results revealed that 22 genes were up-regulated and 12 genes were down-regulated in response to Aloe emodin treatment. These genes were then grouped into several clusters based on their biological functions, revealing induction of expression of genes involved in apoptosis (programmed cell death) and tissue remodelling in U87 cells (p<0.01). Several genes with significant changes of the expression level e.g. SHARPIN, BCAP31, FIS1, RAC1 and TGM2 from the apoptotic cluster were confirmed by quantitative real-time PCR (qRT-PCR). These results could serve as guidance for further studies in order to discover molecular targets for the cancer therapy based on Aloe emodin treatment.
  5. Hanapi NA, Mohamad Arshad AS, Abdullah JM, Tengku Muhammad TS, Yusof SR
    J Pharm Sci, 2021 02;110(2):698-706.
    PMID: 32949562 DOI: 10.1016/j.xphs.2020.09.015
    Neurotherapeutic potentials of Centella asiatica and its reputation to boost memory, prevent cognitive deficits and improve brain functions are widely acknowledged. The plant's bioactive compounds, i.e. asiaticoside, madecassoside and asiatic acid were reported to have central nervous system (CNS) actions, particularly in protecting the brain against neurodegenerative disorders. Hence, it is important for these compounds to cross the blood-brain barrier (BBB) to be clinically effective therapeutics. This study aimed to explore the capability of asiaticoside, madecassoside and asiatic acid to cross the BBB using in vitro BBB model from primary porcine brain endothelial cells (PBECs). Our findings showed that asiaticoside, madecassoside and asiatic acid are highly BBB permeable with apparent permeability (Papp) of 70.61 ± 6.60, 53.31 ± 12.55 and 50.94 ± 10.91 × 10-6 cm/s respectively. No evidence of cytotoxicity and tight junction disruption of the PBECs were observed in the presence of these compounds. Asiatic acid showed cytoprotective effect towards the PBECs against oxidative stress. This study reported for the first time that Centella asiatica compounds demonstrated high capability to cross the BBB, comparable to central nervous system drugs, and therefore warrant further development as therapeutics for the treatment of neurodegenerative diseases.
  6. Sahrizan NSA, Manan HA, Abdul Hamid H, Abdullah JM, Yahya N
    Cancers (Basel), 2023 Apr 06;15(7).
    PMID: 37046828 DOI: 10.3390/cancers15072168
    Working memory, language and speech abilities, motor skills, and visual abilities are often impaired in children with brain tumours. This is because tumours can invade the brain's functional areas and cause alterations to the neuronal networks. However, it is unclear what the mechanism of tumour invasion is and how various treatments can cause cognitive impairment. Therefore, this study aims to systematically evaluate the effects of tumour invasion on the cognitive, language, motor, and visual abilities of paediatric patients, as well as discuss the alterations and modifications in neuronal networks and anatomy. The electronic database, PubMed, was used to find relevant studies. The studies were systematically reviewed based on the type and location of brain tumours, cognitive assessment, and pre- and post-operative deficits experienced by patients. Sixteen studies were selected based on the inclusion and exclusion criteria following the guidelines from PRISMA. Most studies agree that tumour invasion in the brain causes cognitive dysfunction and alteration in patients. The effects of a tumour on cognition, language, motor, and visual abilities depend on the type of tumour and its location in the brain. The alteration to the neuronal networks is also dependent on the type and location of the tumour. However, the default mode network (DMN) is the most affected network, regardless of the tumour type and location.Furthermore, our findings suggest that different treatment types can also contribute to patients' cognitive function to improve or deteriorate. Deficits that persisted or were acquired after surgery could result from surgical manipulation or the progression of the tumour's growth. Meanwhile, recovery from the deficits indicated that the brain has the ability to recover and reorganise itself.
  7. Lau BL, Idris Z, Abdullah JM, Bujang MA, Wong ASH
    Br J Neurosurg, 2023 Dec;37(6):1572-1579.
    PMID: 33191803 DOI: 10.1080/02688697.2020.1837728
    BACKGROUND: A new stereotactic frame was created in 2015, based on a linear algorithm. It is called Albert Wong (AW) frame. A simple AW stereo-calculator was also designed based on Excel® (Microscoft Corporation, Redmond, WA) programme for the frame.

    OBJECTIVE: The aim of this study is to test the accuracy of the AW frame by a direct head to head comparison with CRW® frame (Integra Life Sciences, Plainsboro, NJ) on a phantom.

    METHODS: This is a prospective pilot cross-sectional phantom study with a total of 42 (21 for AW and 21 for CRW®) laboratory testings performed in 2017 at our institute to compare the accuracies of both frames in a consecutive manner. A phantom (BL phantom) was newly created, where targets can be placed at different heights and positions on a platform attached under the frame for accuracy testing comparing between the AW and CRW® frames.

    RESULTS: A comparable accuracy testing results were observed between the AW and CRW® frames of 0.64 mm versus 1.07 mm respectively. Approval from the local ethics committee for a clinical trial was obtained. We report on three case illustrations who had the AW frame-based biopsies with definitive diagnoses and without any post-biopsy related complication.

    CONCLUSION: AW frame successfully demonstrated a good accuracy of 0.64 mm in phantom testing using the BL phantom by a linear algorithmic calculation. The clinical trial with three patients demonstrated definitive diagnoses and safety with its use.

  8. Goh CH, Abdullah JY, Idris Z, Ghani ARI, Abdullah JM, Wong ASH, et al.
    Malays J Med Sci, 2020 May;27(3):53-60.
    PMID: 32684806 DOI: 10.21315/mjms2020.27.3.6
    Background: Deep brain stimulation (DBS) was pioneered by Neuroscience team of Hospital Universiti Sains Malaysia (HUSM) nearly a decade ago to treat advanced medically refractory idiopathic Parkinson's disease (IPD) patients.

    Objectives: Brain volume reduction occurs with age, especially in Parkinson plus syndrome or psychiatric disorders. We searched to define the degree of volume discrepancy in advanced IPD patients and correlate the anatomical volumetric changes to motor symptoms and cognitive function.

    Methods: We determined the magnetic resonance imaging (MRI)-based volumetry of deep brain nuclei and brain structures of DBS-IPD group and matched controls.

    Results: DBS-IPD group had significant deep nuclei atrophy and volume discrepancy, yet none had cognitive or psychobehavioural disturbances. Globus pallidus volume showed positive correlation to higher mental function.

    Conclusion: The morphometric changes and clinical severity discrepancy in IPD may imply a more complex degenerative mechanism involving multiple neural pathways. Such alteration could be early changes before clinical manifestation.

  9. Galler JR, Bringas-Vega ML, Tang Q, Rabinowitz AG, Musa KI, Chai WJ, et al.
    Neuroimage, 2021 05 01;231:117828.
    PMID: 33549754 DOI: 10.1016/j.neuroimage.2021.117828
    Approximately one in five children worldwide suffers from childhood malnutrition and its complications, including increased susceptibility to inflammation and infectious diseases. Due to improved early interventions, most of these children now survive early malnutrition, even in low-resource settings (LRS). However, many continue to exhibit neurodevelopmental deficits, including low IQ, poor school performance, and behavioral problems over their lifetimes. Most studies have relied on neuropsychological tests, school performance, and mental health and behavioral measures. Few studies, in contrast, have assessed brain structure and function, and to date, these have mainly relied on low-cost techniques, including electroencephalography (EEG) and evoked potentials (ERP). The use of more advanced methods of neuroimaging, including magnetic resonance imaging (MRI) and functional near-infrared spectroscopy (fNIRS), has been limited by cost factors and lack of availability of these technologies in developing countries, where malnutrition is nearly ubiquitous. This report summarizes the current state of knowledge and evidence gaps regarding childhood malnutrition and the study of its impact on neurodevelopment. It may help to inform the development of new strategies to improve the identification, classification, and treatment of neurodevelopmental disabilities in underserved populations at the highest risk for childhood malnutrition.
  10. Malik AS, Khairuddin RN, Amin HU, Smith ML, Kamel N, Abdullah JM, et al.
    Biomed Eng Online, 2015;14:21.
    PMID: 25886584 DOI: 10.1186/s12938-015-0006-8
    Consumer preference is rapidly changing from 2D to 3D movies due to the sensational effects of 3D scenes, like those in Avatar and The Hobbit. Two 3D viewing technologies are available: active shutter glasses and passive polarized glasses. However, there are consistent reports of discomfort while viewing in 3D mode where the discomfort may refer to dizziness, headaches, nausea or simply not being able to see in 3D continuously.
  11. Zamzuri I, Abdullah JM, Samsudin AR
    Med J Malaysia, 2004 Oct;59(4):552-4.
    PMID: 15779595
    We report a case of a 6 month old baby boy who had congenital nasal encephalocele, repaired via the traditional staging procedure. The surgical techniques and procedures are described and discussed.
  12. Elaina NS, Malik AS, Shams WK, Badruddin N, Abdullah JM, Reza MF
    Clin Neuroradiol, 2018 Jun;28(2):267-281.
    PMID: 28116447 DOI: 10.1007/s00062-017-0557-0
    PURPOSE: To localize sensorimotor cortical activation in 10 patients with frontoparietal tumors using quantitative magnetoencephalography (MEG) with noise-normalized approaches.

    MATERIAL AND METHODS: Somatosensory evoked magnetic fields (SEFs) were elicited in 10 patients with somatosensory tumors and in 10 control participants using electrical stimulation of the median nerve via the right and left wrists. We localized the N20m component of the SEFs using dynamic statistical parametric mapping (dSPM) and standardized low-resolution brain electromagnetic tomography (sLORETA) combined with 3D magnetic resonance imaging (MRI). The obtained coordinates were compared between groups. Finally, we statistically evaluated the N20m parameters across hemispheres using non-parametric statistical tests.

    RESULTS: The N20m sources were accurately localized to Brodmann area 3b in all members of the control group and in seven of the patients; however, the sources were shifted in three patients relative to locations outside the primary somatosensory cortex (SI). Compared with the affected (tumor) hemispheres in the patient group, N20m amplitudes and the strengths of the current sources were significantly lower in the unaffected hemispheres and in both hemispheres of the control group. These results were consistent for both dSPM and sLORETA approaches.

    CONCLUSION: Tumors in the sensorimotor cortex lead to cortical functional reorganization and an increase in N20m amplitude and current-source strengths. Noise-normalized approaches for MEG analysis that are integrated with MRI show accurate and reliable localization of sensorimotor function.

  13. Zafar R, Kamel N, Naufal M, Malik AS, Dass SC, Ahmad RF, et al.
    Australas Phys Eng Sci Med, 2018 Sep;41(3):633-645.
    PMID: 29948968 DOI: 10.1007/s13246-018-0656-5
    Neuroscientists have investigated the functionality of the brain in detail and achieved remarkable results but this area still need further research. Functional magnetic resonance imaging (fMRI) is considered as the most reliable and accurate technique to decode the human brain activity, on the other hand electroencephalography (EEG) is a portable and low cost solution in brain research. The purpose of this study is to find whether EEG can be used to decode the brain activity patterns like fMRI. In fMRI, data from a very specific brain region is enough to decode the brain activity patterns due to the quality of data. On the other hand, EEG can measure the rapid changes in neuronal activity patterns due to its higher temporal resolution i.e., in msec. These rapid changes mostly occur in different brain regions. In this study, multivariate pattern analysis (MVPA) is used both for EEG and fMRI data analysis and the information is extracted from distributed activation patterns of the brain. The significant information among different classes is extracted using two sample t test in both data sets. Finally, the classification analysis is done using the support vector machine. A fair comparison of both data sets is done using the same analysis techniques, moreover simultaneously collected data of EEG and fMRI is used for this comparison. The final analysis is done with the data of eight participants; the average result of all conditions are found which is 65.7% for EEG data set and 64.1% for fMRI data set. It concludes that EEG is capable of doing brain decoding with the data from multiple brain regions. In other words, decoding accuracy with EEG MVPA is as good as fMRI MVPA and is above chance level.
  14. Zafar R, Kamel N, Naufal M, Malik AS, Dass SC, Ahmad RF, et al.
    J Integr Neurosci, 2017;16(3):275-289.
    PMID: 28891512 DOI: 10.3233/JIN-170016
    Decoding of human brain activity has always been a primary goal in neuroscience especially with functional magnetic resonance imaging (fMRI) data. In recent years, Convolutional neural network (CNN) has become a popular method for the extraction of features due to its higher accuracy, however it needs a lot of computation and training data. In this study, an algorithm is developed using Multivariate pattern analysis (MVPA) and modified CNN to decode the behavior of brain for different images with limited data set. Selection of significant features is an important part of fMRI data analysis, since it reduces the computational burden and improves the prediction performance; significant features are selected using t-test. MVPA uses machine learning algorithms to classify different brain states and helps in prediction during the task. General linear model (GLM) is used to find the unknown parameters of every individual voxel and the classification is done using multi-class support vector machine (SVM). MVPA-CNN based proposed algorithm is compared with region of interest (ROI) based method and MVPA based estimated values. The proposed method showed better overall accuracy (68.6%) compared to ROI (61.88%) and estimation values (64.17%).
  15. Sofian ZM, Abdullah JM, Rahim AA, Shafee SS, Mustafa Z, Razak SA
    Pak J Pharm Sci, 2012 Oct;25(4):831-7.
    PMID: 23010001
    The possible cytotoxic effects of vancomycin and its complex with beta-cyclodextrin (β-CD) on human glial cell line (CRL 8621) were studied accordingly by means of MTS assay. The cultured cells were incubated with various concentrations of vancomycin, β-CD as well as β-CD/vancomycin complex ranging from 4.69 to 300 ug/ml. A linear dose-dependency cytotoxicity followed by hermetic-like biphasic dose-dependence was observed after incubation period of 72 hours. In general, significant increase (p<0.001) of cell proliferation was observed at lower concentrations: <18.75 μg/ml for cells treated with β-CD and their complex while < 9.38 μg/ml for cells treated with vancomycin. In contrary, regardless of the treatments given, significant (p<0.001) reduce in cell survival was found at higher concentrations >150 μg/ml. In particular, 50 % inhibitory in vitro was achieved at the concentrations of 115.95 μg/ml (for β-CD), 116.48 μg/ml (for vancomycin) and 115.44 μg/ml (for β-CD/vancomycin complex).
  16. Tan EH, Yusoff AA, Abdullah JM, Razak SA
    J Pediatr Neurosci, 2012 May;7(2):123-5.
    PMID: 23248692 DOI: 10.4103/1817-1745.102575
    In this report, we describe a 15-year-old Malaysian male patient with a de novo SCN1A mutation who experienced prolonged febrile seizures after his first seizure at 6 months of age. This boy had generalized tonic clonic seizure (GTCS) which occurred with and without fever. Sequencing analysis of voltage-gated sodium channel a1-subunit gene, SCN1A, confirmed a homozygous A to G change at nucleotide 5197 (c.5197A > G) in exon 26 resulting in amino acid substitution of asparagines to aspartate at codon 1733 of sodium channel. The mutation identified in this patient is located in the pore-forming loop of SCN1A and this case report suggests missense mutation in pore-forming loop causes generalized epilepsy with febrile seizure plus (GEFS+) with clinically more severe neurologic phenotype including intellectual disabilities (mental retardation and autism features) and neuropsychiatric disease (anxiety disorder).
  17. Awang MS, Abdullah JM, Abdullah MR, Tahir A, Tharakan J, Prasad A, et al.
    Med Sci Monit, 2007 Jul;13(7):CR330-2.
    PMID: 17599028
    Nerve conduction study is essential in the diagnosis of focal neuropathies and diffuse polyneuropathies. There are many factors that can affect nerve conduction velocity, and age is one of them. Most of the many studies of this effect, and the values from them, were on Caucasian subjects. Therefore, this study was designed to investigate the effect of age on conduction velocity among healthy Asian Malay subjects by analyzing its influence on the median, ulnar, and sural nerves.
  18. Sofian ZM, Shafee SS, Abdullah JM, Osman H, Razak SA
    Malays J Med Sci, 2014 Dec;21(Spec Issue):6-11.
    PMID: 25941458
    A simple, reliable a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium, (MTS) assay was conducted to evaluate the potential cytotoxic effects of levodopa, a "gold standard therapy" for Parkinsonism, and its complex with Hydroxypropyl-β-Cyclodextrin (HP-β-CD) on an astrocyte cell line. The cells were incubated in a range of concentrations from 4.69 to 300 μg/mL levodopa, HP-β-CD or the complex for up to 72 hours. At every 24-hour interval, the optical density (OD), which reflects the number of viable cells, was recorded. In general, linear dose-dependent cytotoxicity profiles were observed for the cells subjected to levodopa or the complex, whereas a slightly triphasic response was observed for the cells exposed to HP-β-CD. A significant difference (P < 0.05) in cytotoxicity was detected between the HP-β-CD-treated group and the levodopa-treated group. In particular, we observed that the cells treated with the complex, even at the highest concentrations (> 200 μg/mL), exhibited improved tolerability in a time-dependent manner, which may indicate the potential ability of HP-β-CD to mask the toxic effects of levodopa via complexation.
  19. Abdullah JM, Hussin AM, Tharakan J, Abdullah MR, Saad R, Kamari Z, et al.
    PMID: 17121309
    The number of cases of neurological disease is expected to rise in the next 10 years, making this the second leading cause of morbidity and mortality after heart disease in Malaysia. The lack of human resources in the neurological field currently serving the Malaysian population may cause a deficiency in specialized care, especially in rural areas where neurological and neurosurgical care may be lacking. Thus, a resolve was made to increase the numbers of specialists by the Universiti Sains Malaysia (USM) with the help of the Ministry of Health of Malaysia. A study was made to evaluate the number of referral centers needed in strategic parts of Malaysia. Our calculation was based on service demands and operative procedures following the guidelines of the Association of British Neurologists (ABN) where 15 minutes of service time was equivalent to 1 unit. Based on 2 million population covered in the state of Kelantan by this University Hospital, 4.27 neurologists are needed to meet service demands with a consultant to population ratio (CPR) of 1:468,384, compared to 7.46 neurosurgeons, with a CPR of 1:268,097. According to the current service demands, one neurologist has to work more than 407 hours per year and one neurosurgeon 1,219 hours per year in our hospital. Hospitals with a larger catchment area would need to have more neurologists and neurosurgeons for optimal care in their area. Thus, more neurologists and neurosurgeons are needed to be produced, since the existing numbers are too small for quality care in Malaysia.
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