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Heavy metals concentration relationship with Perna viridis physical properties in Mengkabong Lagoon, Sabah, Malaysia

Abdullah N, Tair R, Abdullah MH

Pak J Biol Sci, 2014 Jan 01;17(1):62-7.
PMID: 24783779

Perna viridis (P. viridis) has been identified as a good biological indicator in identifying environmental pollution, especially when there are various types of Heavy Metals Accumulations (HMA) inside its tissue. Based on the potential of P. viridis to accumulate heavy metals and the data on its physical properties, this study proffers to determine the relationships between both properties. The similarities of the physical properties are used to mathematical model their relationships, which included the size (length, width, height) and weight (wet and dry) of P. viridis, whilst the heavy metals are focused on concentrations of Pb, Cu, Cr, Cd and Zn. The concentrations of metal elements are detected by using Flame Atomic Adsorption Spectrometry. Results show that the mean concentration of Pb, Cu, Cr, Cd, Zn, length, width, height, wet weight and dry weight are: 1.12 +/- 1.00, 2.36 +/- 1.65, 2.12 +/- 2.74, 0.44 +/- 0.41 and 16.52 +/- 10.64 mg kg(-1) (dry weight), 105.08 +/- 14.35, 41.64 +/- 4.64, 28.75 +/- 3.92 mm, 14.56 +/- 3.30 and 2.37 +/- 0.86 g, respectively. It is also found out that the relationships between the Heavy Metals Concentrations (HMA) and the physical properties can be represented using Multiple Linear Regressions (MLR) models, relating that the HMA of Zinc has affected significantly the physical growth properties of P. viridis.
Multivariate and Geoaccumulation Index evaluation in mangrove surface sediment of Mengkabong lagoon, Sabah

Praveena SM, Ahmed A, Radojevic M, Abdullah MH, Aris AZ

Bull Environ Contam Toxicol, 2008 Jul;81(1):52-6.
PMID: 18506379 DOI: 10.1007/s00128-008-9460-3

Spatial variations in estuarine intertidal sediment have been often related to such environmental variables as salinity, sediment types, heavy metals and base cations. However, there have been few attempts to investigate the difference condition between high and low tides relationships and to predict their likely responses in an estuarine environment. This paper investigates the linkages between environmental variables and tides of estuarine intertidal sediment in order to provide a basis for describing the effect of tides in the Mengkabong lagoon, Sabah. Multivariate statistical technique, principal components analysis (PCA) was employed to better interpret information about the sediment and its controlling factors in the intertidal zone. The calculation of Geoaccumulation Index (I(geo)) suggests the Mengkabong mangrove sediments are having background concentrations for Al, Cu, Fe, and Zn and unpolluted for Pb. Extra efforts should therefore pay attention to understand the mechanisms and quantification of different pathways of exchange within and between intertidal zones.
Assessment of heavy metals contamination in Mamut river sediments using sediment quality guidelines and geochemical indices

Mohammad Ali BN, Lin CY, Cleophas F, Abdullah MH, Musta B

Environ Monit Assess, 2015 Jan;187(1):4190.
PMID: 25471626 DOI: 10.1007/s10661-014-4190-y

This paper describes the concentration of selected heavy metals (Co, Cu, Ni, Pb, and Zn) in the Mamut river sediments and evaluate the degree of contamination of the river polluted by a disused copper mine. Based on the analytical results, copper showed the highest concentration in most of the river samples. A comparison with Interim Canadian Sediment Quality Guidelines (ICSQG) and Germany Sediment Quality Guidelines (GSQG) indicated that the sediment samples in all the sampling stations, except Mamut river control site (M1), exceeded the limit established for Cu, Ni, and Pb. On the contrary, Zn concentrations were reported well below the guidelines limit (ICSQG and GSQG). Mineralogical analysis indicated that the Mamut river sediments were primarily composed of quartz and accessory minerals such as chalcopyrite, pyrite, edenite, kaolinite, mica, and muscovite, reflected by the geological character of the study area. Enrichment factor (EF) and geoaccumulation index (Igeo) were calculated to evaluate the heavy metal pollution in river sediments. Igeo values indicated that all the sites were strongly polluted with the studied metals in most sampling stations, specifically those located along the Mamut main stream. The enrichment factor with value greater than 1.5 suggested that the source of heavy metals was mainly derived from anthropogenic activity such as mining. The degree of metal changes (δfold) revealed that Cu concentration in the river sediments has increased as much as 20 to 38 folds since the preliminary investigation conducted in year 2004.
Fulltext Peripheral blood gene expression profile of atherosclerotic coronary artery disease in patients of different ethnicity in Malaysia

Abdullah MH, Othman Z, Noor HM, Arshad SS, Yusof AK, Jamal R, et al.

J Cardiol, 2012 Sep;60(3):192-203.
PMID: 22738689 DOI: 10.1016/j.jjcc.2012.05.009

The molecular basis of coronary artery disease (CAD) has been widely studied in the western world but there is no published work on the Malaysian population. This study looked at the global gene expression profiling of the peripheral blood of patients with CAD from the 3 main ethnic groups in Malaysia. Male subjects selected were based on angiographically confirmed CAD (≥50% stenosis) and normal control subjects (0% stenosis) with age range of 55.6±5.3 and 51.0±5.5 years, respectively. The global gene expression of 12 angiographically documented CAD patients and 11 matched control subjects were performed. The combined group samples identified 6 up regulated differential expression (DE) genes (GHRL, LTA, CBS, HP, ITGA2B, and OLR1) and 12 down regulated DE genes (IL18R1, ITGA2B, IL18RAP, HP, OLR1, SOD2 ITGB3, IL1B, MMP9, PLA2G7, UTS2, and CBS) to be involved in CAD at the fold change of 1.3 with fault discovery rate (FDR) of 1%. Three genes, MMP9, IL1B, and SOD2 were down regulated in all the 3 ethnic groups making them potential biomarker candidates for CAD across all three ethnicities. Further verification in a cohort study is needed.
Exogenous hydrogen sulfide (H2S) reduces blood pressure and prevents the progression of diabetic nephropathy in spontaneously hypertensive rats

Ahmad FU, Sattar MA, Rathore HA, Abdullah MH, Tan S, Abdullah NA, et al.

Ren Fail, 2012;34(2):203-10.
PMID: 22229751 DOI: 10.3109/0886022X.2011.643365

The coexistence of hypertension and diabetes results in the rapid development of nephropathy. Hydrogen sulfide (H2S) is claimed to control the vascular and renal functions. This study tested the hypothesis that exogenous H2S lowers the blood pressure and decreases the progression of nephropathy in spontaneously hypertensive rats (SHR) that were diabetic. Eighteen SHR were divided into three groups: SHR, SHR diabetic, and SHR diabetic treated with a group of Wistar-Kyoto rats serving as normotensive nondiabetic control. Diabetes was induced with streptozotocin (STZ) in two groups and one diabetic group received sodium hydrosulfide (NaHS), a H2S donor for 5 weeks. Blood pressure was measured in conscious and anesthetized states and renal cortical blood perfusion in acute studies. Plasma and urinary H2S levels, creatinine concentrations, and electrolytes were measured on three different occasions throughout the 35-day period. Diabetic SHR had higher blood pressure, lower plasma and urinary H2S levels, and renal dysfunction as evidenced by increased plasma creatinine, creatinine clearance, and decreased urinary sodium-to-potassium ratio and renal cortical blood perfusion. NaHS reduced blood pressure, increased H2S levels in plasma and urinary excretion, and reversed the STZ-induced renal dysfunction. The findings of this study suggest that the administration of exogenous H2S lowers the blood pressure and confers protection against the progression of STZ-induced nephropathy in SHR.
Fulltext Waste Fiber-Based Poly(hydroxamic acid) Ligand for Toxic Metals Removal from Industrial Wastewater

Rahman ML, Wong ZJ, Sarjadi MS, Joseph CG, Arshad SE, Musta B, et al.

Polymers (Basel), 2021 May 06;13(9).
PMID: 34066308 DOI: 10.3390/polym13091486

Toxic metals in the industrial wastewaters have been liable for drastic pollution hence a powerful and economical treatment technology is needed for water purification. For this reason, some pure cellulosic materials were derived from waste fiber to obtain an economical adsorbent for wastewater treatment. Conversion of cellulose into grafting materials such as poly(methyl acrylate)-grafted cellulose was performed by free radical grafting process. Consequently, poly(hydroxamic acid) ligand was produced from the grafted cellulose. The intermediate products and poly(hydroxamic acid) ligand were analyzed by FT-IR, FE-SEM, TEM, EDX, and XPS spectroscopy. The adsorption capacity (qe) of some toxic metals ions by the polymer ligand was found to be excellent, e.g., copper capacity (qe) was 346.7 mg·g-1 at pH 6. On the other hand, several metal ions such as cobalt chromium and nickel also demonstrated noteworthy sorption capacity at pH 6. The adsorption mechanism obeyed the pseudo second-order rate kinetic model due to the satisfactory correlated experimental sorption values (qe). Langmuir model isotherm study showed the significant correlation coefficient with all metal ions (R2 > 0.99), indicating that the single or monolayer adsorption was the dominant mode on the surface of the adsorbent. This polymer ligand showed good properties on reusability. The result shows that the adsorbent may be recycled for 6 cycles without any dropping of starting sorption capabilities. This polymeric ligand showed outstanding toxic metals removal magnitude, up to 90-99% of toxic metal ions can be removed from industrial wastewater.
Fulltext Fear conditioning: Insights into learning, memory and extinction and its relevance to clinical disorders

Trent S, Abdullah MH, Parwana K, Valdivieso MA, Hassan Z, Müller CP

Prog Neuropsychopharmacol Biol Psychiatry, 2025 Mar 06;138:111310.
PMID: 40056965 DOI: 10.1016/j.pnpbp.2025.111310

Fear, whether innate or learned, is an essential emotion required for survival. The learning, and subsequent memory, of fearful events enhances our ability to recognise and respond to threats, aiding adaptation to new, ever-changing environments. Considerable research has leveraged associative learning protocols such as contextual or auditory forms of fear conditioning in rodents, to understand fear learning, memory consolidation and extinction phases of memory. Such assays have led to detailed characterisation of the underlying neurocircuitry and neurobiology supporting fear learning processes. Given fear processing is conserved across rodents and humans, fear conditioning experiments provide translational insights into fundamental memory processes and fear-related pathologies. This review examines associative learning protocols used to measure fear learning, memory and extinction, before providing an overview on the underlying complex neurocircuitry including the amygdala, hippocampus and medial prefrontal cortex. This is followed by an in-depth commentary on the neurobiology, particularly synaptic plasticity mechanisms, which regulate fear learning, memory and extinction. Next, we consider how fear conditioning assays in rodents can inform our understanding of disrupted fear memory in human disorders such as post-traumatic stress disorder (PTSD), anxiety and psychiatric disorders including schizophrenia. Lastly, we critically evaluate fear conditioning protocols, highlighting some of the experimental and theoretical limitations and the considerations required when conducting such assays, alongside recent methodological advancements in the field. Overall, rodent-based fear conditioning assays remain central to making progress in uncovering fundamental memory phenomena and understanding the aetiological mechanisms that underpin fear associated disorders, alongside the development of effective therapeutic strategies.
Architectural Regulation of T-Lymphocyte Function in Hepatocellular Carcinoma: Current Evidence and Translational Opportunities

Abdullah MH, Zulkifle N, Suhaimi SA, Aziz MY, Mohamed R

FASEB J, 2026 Oct 31;40(20).
PMID: 42910499 DOI: 10.1096/fj.202603114R

Hepatocellular carcinoma (HCC) develops within a chronically injured liver in which anti-tumor immunity is governed not only by immune-cell abundance and checkpoint signaling, but also by the spatial, mechanical, and multicellular organization of T lymphocytes. This review reframes T-cell architecture as a regulatory layer operating across molecular, cellular, and tissue scales. Cytoskeletal remodeling, immunological synapse geometry, mechanotransduction, vascular positioning, stromal exclusion, and tertiary lymphoid structure (TLS) organization collectively influence T-cell activation thresholds, effector competence, exhaustion trajectories, and therapeutic responsiveness. We synthesize HCC-specific evidence from spatial transcriptomics, multiplex imaging, digital pathology, and clinical cohorts, while clearly distinguishing direct HCC observations from mechanisms extrapolated from other solid tumors or foundational T-cell biology. Current evidence supports the prognostic relevance of intratumoral CD8+ localisation, perivascular immune rims, fibrotic exclusion niches, and mature intratumoral TLS, but causal links between architecture and T-cell fate remain incompletely defined. We propose an architecture-guided framework in which spatial immune states serve as both biomarkers and modifiable therapeutic targets. Spatially informed checkpoint blockade, engineered T-cell therapy, stromal and vascular remodeling, AI-assisted pathology, and organoid or liver-on-chip models may enable more precise immunotherapy strategies for HCC.
Antioxidant and cardio protective effect of palm oil leaves extract (standardized ethanolic fraction) in rats' model of saturated fats induced metabolic disorders

Ibraheem ZO, Satar M, Abdullah NA, Rathore H, Tan YC, Uldin F, et al.

Pak J Pharm Sci, 2014 Jan;27(1):1-9.
PMID: 24374430

Recently, it is suggested to use POLE (palm oil leaf extract) as a nutraceutical health product in food industry due to its newly discovered content of polyphenols and antioxidant vitamins. In the experiment, the antioxidant and anti-lipid-peroxidation activities of the extract were confirmed using; DPPH (1-diphenyl-2-picryl-hydrazil) radical scavenging activity, ferric ion induced lipid peroxidation inhibition, reducing power and hydrogen peroxide scavenging activity assays. The cardio-protective activity was studied in vivo using a model of metabolic syndrome induced by high fat diet. Lipid profile, obesity indices, renal tubular handling of water and electrolytes, blood pressure and arterial stiffness were measured at the end of the treatment period. Sprague Dawley rats weighing 150-200 g were divided into six groups, viz; group C; was treated as a negative control and fed with standard rodents chow, group H; was treated as a positive control and fed with an experimental diet enriched with saturated free fatty acids for 8 weeks, groups HP0.5, HP1 and HP2 which were fed with 0.5,1 and 2 g/kg (body weight) /day of POLE orally during the last 24 days of the high fat diet feeding period and group P; fed with highest dose of POLE. Results revealed that POLE possesses a cardio-protective effect which is ascribed to its content of polyphenols.
Effects of clitorienolactones from Clitoria ternatea root on calcium channel mediating hippocampal long-term potentiation in rats induced chronic cerebral hypoperfusion

Ahad MA, Chear NJ, Abdullah MH, Ching-Ga TAF, Liao P, Wei S, et al.

Ageing Res Rev, 2024 Apr;96:102252.
PMID: 38442748 DOI: 10.1016/j.arr.2024.102252

Chronic cerebral hypoperfusion (CCH) is a common mechanism of acute brain injury due to impairment of blood flow to the brain. Moreover, a prolonged lack of oxygen supply may result in cerebral infarction or global ischemia, which subsequently causes long-term memory impairment. Research on using Clitoria ternatea root extract for treating long-term memory has been studied extensively. However, the bioactive compound contributing to its neuroprotective effects remains uncertain. In the present study, we investigate the effects of clitorienolactone A (CLA) and B (CLB) from the roots of Clitoria ternatea extract on hippocampal neuroplasticity in rats induced by CCH. CLA and CLB were obtained using column chromatography. The rat model of CCH was induced using two-vessel occlusion surgery (2VO). The 2VO rats were given 10 mg/kg of CLA and CLB orally, followed by hippocampal neuroplasticity recording using in vivo electrophysiological. Rats received CLA and CLB (10 mg/kg) significantly reversed the impairment of long-term potentiation following 2VO surgery. Furthermore, we investigate the effect of CLA and CLB on the calcium channel using the calcium imaging technique. During hypoxia, CLA and CLB sustain the increase in intracellular calcium levels. We next predict the binding interactions of CLA and CLB against NMDA receptors containing GluN2A and GluN2B subunits using in silico molecular docking. Our result found that both CLA and CLB exhibited lower binding affinity against GluN2A and GluN2B subunits. Our findings demonstrated that bioactive compounds from Clitoria ternatea improved long-term memory deficits in the chronic cerebral hypoperfusion rat model via calcium uptake. Hence, CLA and CLB could be potential therapeutic tools for treating cognitive dysfunction.
Stakeholders' perspectives on disinvestment of low-value healthcare interventions and practices in Malaysia: an online survey

Kamaruzaman HF, Grieve E, Ku Abd Rahim KN, Izzuna M, Sit Wai L, Romli EZ, et al.

Int J Technol Assess Health Care, 2024 Nov 15;40(1):e57.
PMID: 39544076 DOI: 10.1017/S0266462324004665

OBJECTIVES: Healthcare disinvestment requires multi-level decision-making, and early stakeholder engagement is essential to facilitate implementation and acceptance. This study aimed to explore the perceptions of Malaysian healthcare stakeholders to disinvestment initiatives as well as identify disinvestment activities in the country.
METHODS: A cross-sectional online survey was conducted from February to March 2023 among Malaysian healthcare stakeholders involved in resource allocation and decision-making at various levels of governance. Response frequencies were analyzed descriptively and cross-tabulation was performed for specific questions to compare the responses of different groups of stakeholders. For free-text replies, content analysis was used with each verbatim response examined and assigned a theme.
RESULTS: A total of 153 complete responses were analyzed and approximately 37 percent of participants had prior involvement in disinvestment initiatives. Clinical effectiveness and cost-effectiveness ranked as the most important criteria in assessment for disinvestment. Surprisingly, equity was rated the lowest priority despite its crucial role in healthcare decision-making. Almost 90 percent of the respondents concurred that a formal disinvestment framework is necessary and the importance of training for the program's successful implementation. Key obstacles to the adoption of disinvestment include insufficient stakeholder support and political will as well as a lack of expertise in executing the process.
CONCLUSIONS: While disinvestment is perceived as a priority for efficient resource allocation in Malaysian healthcare, there is a lack of a systematic framework for its implementation. Future research should prioritize methodological analysis in healthcare disinvestment and strategies for integrating equity considerations in evaluating disinvestment candidates.
Poly(amidoxime) ligand derived from waste palm fiber for the removal of heavy metals from electroplating wastewater

Rahman ML, Fui CJ, Sarjadi MS, Arshad SE, Musta B, Abdullah MH, et al.

Environ Sci Pollut Res Int, 2020 Sep;27(27):34541-34556.
PMID: 32557073 DOI: 10.1007/s11356-020-09462-0

A waste material known as palm oil empty fruit bunch (EFB) is used as a source of cellulose for the development of polymeric materials for the removal of metal ions from industrial wastewater. A poly(acrylonitrile)-grafted palm cellulose copolymer was synthesized by a conventional free radical initiating process followed by synthesis of a poly(amidoxime) ligand by oximation reaction. The resulting products were characterized by FT-IR, FE-SEM, EDX, TGA, DSC, and XPS. The poly(amidoxime) ligand was used to coordinate with and extract a series of transition metal ions from water samples. The binding capacity (qe) of the ligand with the metal ions such as copper, iron, cobalt, nickel, and lead were 260, 210, 168, 172, and 272 mg g-1, respectively at pH 6. The adsorption process followed the pseudo-first-order kinetic model (R2 > 0.99) and as well as the Freundlich isotherm model (R2 > 0.99) indicating the occurrence of a multi-layer adsorption process in the amidoxime ligand adsorbent. Results from reusability studies show that the ligand can be recycled for at least 10 cycles without any significant losses to its initial adsorption capacity. The synthesized polymeric ligand was shown to absorb heavy metals from electroplating wastewater with up to 95% efficiency.
Fulltext Mapping the Locations of Medical Specialists in the Ministry of Health's Hospitals in Malaysia by Specialty, Subspecialty and Area of Interest

Ismail H, Abdullah MH, Osman S, Che Arshad F, Jalaluddin SN, Osman NF, et al.

Malays J Med Sci, 2024 Jun;31(3):1-17.
PMID: 38984245 DOI: 10.21315/mjms2024.31.3.1

Mapping the distribution of medical specialists in the Ministry of Health (MOH) Malaysia facilities is expected to be more complex as the demand for specialty and subspecialty services increases in the future. A more robust and definitive gap analysis is needed to facilitate planning and resource allocation. The Medical Development Division developed a master list of framework of specialties, subspecialties and areas of interest, and Specialist Database Module in the Medical Programme Information System (MPIS) as tools to facilitate mapping of services. Relational database of specialists' location, facilities, workload, population profile and other relevant parameters were developed to provide data visualisation in specific dashboard. Needs versus supply ratio is proposed as one of parameters to visualise specialised medical services distribution by geographical localities.
Interaction between renin-angiotensin and sympathetic nervous systems in a rat model of pressure overload cardiac hypertrophy

Rathore HA, Munavvar AS, Abdullah NA, Khan AH, Fathihah B, NurJannah MH, et al.

Auton Autacoid Pharmacol, 2009 Oct;29(4):171-80.
PMID: 19740088 DOI: 10.1111/j.1474-8665.2009.00445.x

1 A raised cardiac workload activates neurohormones which will increase muscle mass and shift contractility to the right along the Frank-Starling curve. 2 This study examined the interaction between the SNS and RAS in contributing to vascular responsiveness following the development of cardiac hypertrophy due to aortic banding. 3 Sprague Dawley rats (180-200 g) were assigned to one of six groups; Normal, Sham-operated, Aortic Banded (AB), Aortic Banded treated with losartan (ABLOS), Aortic Banded treated with 6-hydroxydopamine (ABSYMP) and Aortic banded treated with both losartan and 6-hydroxydopamine (ABSYMPLOS). A constricting band was placed around the supra renal aorta on day zero with drug treatment from day 37 to day 44. Vasopressor responses to noradrenaline, phenylephrine, methoxamine and angiotensin II were measured on day 45. 4 The magnitudes of the MAP responses to all vasoactive agents, expressed as percentage changes, were similar in Normal and Sham groups, but reduced in the AB group. ABLOS group showed attenuated response to ANGII whereas all responses were enhanced in the ABSYM group. 5 A positive interaction between the two systems was observed with alpha(1A)-adrenoceptors identified as a major component of SNS and AT(1) receptors of RAS to induce vasopressor effects.

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