Displaying publications 1 - 20 of 70 in total

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  1. Common variant in the glucokinase regulatory gene rs780094 and risk of nonalcoholic fatty liver disease: a meta-analysis
    Zain SM, Mohamed Z, Mohamed R
    J Gastroenterol Hepatol, 2015 Jan;30(1):21-7.
    PMID: 25167786 DOI: 10.1111/jgh.12714
    BACKGROUND AND AIM: Although studies have suggested that rs780094, a common variant in the glucokinase regulatory (GCKR) gene to be associated with type 2 diabetes, obesity, and their related traits, the genetic basis of the association between GCKR rs780094 and nonalcoholic fatty liver disease (NAFLD) is still being examined. This meta-analysis was performed to evaluate the effect strength caused by GCKR rs780094 on NAFLD.
    METHODS: We searched Medline, PubMed, Scopus, and Embase for relevant articles published up to April 2014. Data were extracted, and summary estimates of the association between GCKR rs780094 and NAFLD were examined. Heterogeneity and publication bias were also examined.
    RESULTS: This meta-analysis incorporated a total of 2091 NAFLD cases and 3003 controls from five studies. Overall, the pooled result indicated that the GCKR rs780094 was significantly associated with increased risk of NAFLD (additive: odds ratio (OR) 1.25, 95% confidence interval (CI) 1.14-1.36, P 
  2. Contamination, bioaccumulation and toxic effects of perfluorinated chemicals (PFCs) in the water environment: a review paper
    Suja F, Pramanik BK, Zain SM
    Water Sci Technol, 2009;60(6):1533-44.
    PMID: 19759456 DOI: 10.2166/wst.2009.504
    Perfluorinated compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctane acid (PFOA) have been recognized as emerging environmental pollutants because of their ubiquitous occurrence in the environment, biota and humans. The paper focuses on the distribution, bioaccumulation and toxic effects of PFOS and PFOA in the water. From the available literature, tap and surface water samples in several countries were found to be contaminated with PFOS and PFOA. These compounds were detected globally in the tissues of fish, bird and marine mammals. Their concentrations from relatively more industrialized areas were greater than those from the less populated and remote locations. Blood samples of occupationally exposed people and the general population in various countries were found to contain PFOS and PFOA which suggested a possibility of atmospheric transport of these compounds. There is still a death of information about the environmental pathways of PFOS and PFOA. The presence of these compounds in the tap water, surface water and animal and human tissues indicates their global contamination and bioaccumulative phenomena in the ecosystems.
  3. Land application technique for the treatment and disposal of sewage sludge
    Zain SM, Basri H, Suja F, Jaafar O
    Water Sci Technol, 2002;46(9):303-8.
    PMID: 12448482
    Some of the major concerns when applying sewage sludge to land include the potential effect on pH and cation exchange capacity; the mobility and the accumulation of heavy metals in sludge treated soil; the potential of applying too much nutrients and the problems associated with odors and insects. The main objective of this study is to identify the effects of sewage sludge application on the physical and chemical properties of sludge treated soil. Sewage sludge was applied to soil at various rates ranging from 0 L/m2 to 341 L/m2. In order to simulate the natural environment, the study was carried out at a pilot treatment site (5.2 m x 6.7 m) in an open area, covered with transparent roofing material to allow natural sunlight to pass through. Simulated rain was applied by means of a sprinkler system. Data obtained from sludge treated soil showed that the pH values decreased when the application rates were increased and the application period prolonged. The effect of sewage sludge on cation exchange capacity was not so clear; the values obtained for every application rate of sewage sludge did not indicate any consistent behaviour. The mobility of heavy metals in soils treated with sludge were described by observing the changes in the concentration of the heavy metals. The study showed that Cd has the highest mobility in sludge treated soil followed by Cu, Cr, Zn, Ni and Pb.
  4. Fulltext Association of vaspin rs2236242 with type 2 diabetes mellitus and obesity: a meta-analysis of case-control studies
    Zain SM, Pung YF, Mohamed R
    J Diabetes Metab Disord, 2023 Jun;22(1):237-243.
    PMID: 37255815 DOI: 10.1007/s40200-022-01119-8
    BACKGROUND: Elevated circulating vaspin levels is linked with type 2 diabetes mellitus (T2DM) and obesity. The genetic basis of the association between vaspin rs2236242 and T2DM and obesity is still being investigated. We executed a meta-analysis to evaluate the magnitude of effect caused by vaspin rs2236242 on T2DM and obesity.

    METHODS: We searched Pubmed, Embase, MEDLINE, Scopus, Web of Science, and Google Scholar for relevant articles published up to 19 February 2022. Data were extracted and summary estimates of the association between vaspin rs2236242 and T2DM and obesity were assessed. Odds ratios (ORs) and confidence intervals (CIs) were used to measure the effect.

    RESULTS: This meta-analysis included 2206 cases and 2715 controls in the T2DM cohort, meanwhile 271 cases and 444 controls in the obesity cohort. The pooled estimates revealed no link between vaspin rs2236242 and T2DM, but allele-A was significantly higher in the controls of the obesity cohort, showing that this single nucleotide polymorphism (SNP) has a reduced obesity risk effect. Sensitivity analysis revealed no studies that would modify the estimates or the heterogeneity. Begg and Mazumdar's and Egger's tests indicated no substantial publication bias.

    CONCLUSION: Our meta-analysis provides evidence of significant association between vaspin rs2236242 and reduced risk of obesity but not T2DM.

    SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40200-022-01119-8.

  5. WITHDRAWN: Kinetics and Mechanism of the Flexible Nanoparticle-Catalyzed Piperidinolysis of Anionic Phenyl Salicylate
    Khalid K, Zain SM, Khan MN
    Chemphyschem, 2015 Jan 29.
    PMID: 25641348
  6. Fulltext Design of new competitive dengue NS2B/NS3 protease inhibitors-a computational approach
    Frimayanti N, Chee CF, Zain SM, Rahman NA
    Int J Mol Sci, 2011;12(2):1089-100.
    PMID: 21541045 DOI: 10.3390/ijms12021089
    Dengue is a serious disease which has become a global health burden in the last decade. Currently, there are no approved vaccines or antiviral therapies to combat the disease. The increasing spread and severity of the dengue virus infection emphasizes the importance of drug discovery strategies that could efficiently and cost-effectively identify antiviral drug leads for development into potent drugs. To this effect, several computational approaches were applied in this work. Initially molecular docking studies of reference ligands to the DEN2 NS2B/NS3 serine protease were carried out. These reference ligands consist of reported competitive inhibitors extracted from Boesenbergia rotunda (i.e., 4-hydroxypanduratin A and panduratin A) and three other synthesized panduratin A derivative compounds (i.e., 246DA, 2446DA and 20H46DA). The design of new lead inhibitors was carried out in two stages. In the first stage, the enzyme complexed to the reference ligands was minimized and their complexation energies (i.e., sum of interaction energy and binding energy) were computed. New compounds as potential dengue inhibitors were then designed by putting various substituents successively on the benzyl ring A of the reference molecule. These substituted benzyl compounds were then computed for their enzyme-ligand complexation energies. New enzyme-ligand complexes, exhibiting the lowest complexation energies and closest to the computed energy for the reference compounds, were then chosen for the next stage manipulation and design, which involved substituting positions 4 and 5 of the benzyl ring A (positions 3 and 4 for 2446DA) with various substituents.
  7. Enantioselective organocatalytic Diels-Alder reactions: a density functional theory and kinetic isotope effects study
    Omar NY, Rahman NA, Zain SM
    J Comput Chem, 2011 Jul 15;32(9):1813-23.
    PMID: 21455954 DOI: 10.1002/jcc.21763
    The mechanism and enantioselectivity of the organocatalytic Diels-Alder reaction were computationally investigated by density functional theory at the B3LYP/6-31G(d) level of theory. The uncatalyzed Diels-Alder reaction was also studied to explore the effect of the organocatalyst on this reaction in terms of energetics, selectivity, and mechanism. The catalyzed reaction showed improved endo/exo selectivity, and the free energy of activation was significantly lowered in the presence of the catalyst. Both uncatalyzed and catalyzed reactions exhibited concerted asynchronous reaction mechanism with the degree of asynchronicity being more evident in the presence of the catalyst. The Corey's experimentally derived predictive selection rules for the outcome of the organocatalytic Diels-Alder reaction were also theoretically analyzed, and an excellent agreement was found between experiment and theory.
  8. Fulltext Pheophorbide b ethyl ester from a chlorella vulgaris dietary supplement
    Chee CF, Rahman NA, Zain SM, Ng SW
    Acta Crystallogr Sect E Struct Rep Online, 2008;64(Pt 10):o1986.
    PMID: 21201185 DOI: 10.1107/S160053680802970X
    In the title compound, C(37)H(38)N(4)O(6), four five-membered nitro-gen-bearing rings are nearly coplanar. Two N atoms in two these five-membered rings have attached H atoms, which contribute to the formation of intra-molecular N-H⋯N hydrogen bonds [N⋯N = 2.713 (5)-3.033 (6) Å].
  9. Phosphatidylethanolamine N-methyltransferase gene rs7946 polymorphism plays a role in risk of nonalcoholic fatty liver disease: evidence from meta-analysis
    Tan HL, Mohamed R, Mohamed Z, Zain SM
    Pharmacogenet Genomics, 2016 Feb;26(2):88-95.
    PMID: 26636496 DOI: 10.1097/FPC.0000000000000193
    Phosphatidylethanolamine N-methyltransferase (PEMT) governs the secretion of hepatic triglycerides in the form of very low-density lipoprotein and has been implicated in nonalcoholic fatty liver disease (NAFLD). Studies on the role of the PEMT rs7946 polymorphism as a genetic modifier of NAFLD have reported inconsistent results. This meta-analysis was carried out to evaluate and summarize the association of PEMT rs7946 with susceptibility to NAFLD.
  10. Fulltext Thinking About Behavior: Perspective on Meta-Behavior in Education
    Amran MS, Zain SM, Jamaludin KA, Surat S
    Front Psychol, 2021;12:727116.
    PMID: 34466138 DOI: 10.3389/fpsyg.2021.727116
    Studies on metacognitive skills have started in the past 30 years and cover various fields, including education. In general, metacognitive skills refer to awareness and monitoring cognitive processes and their ability to sharpen the mind enhancement process. However, much attention has been given to metacognition alone and less focusing on its manifestation in behaviors. Thus, this study aims to conceptualize how metacognitive concepts can be adapted in the context of behaviors. In achieving this, an in-depth analysis of relevant behavioral theories and metacognitive models was conducted. The proposed conceptual framework, named the meta-behavior framework, underscores the importance of the thinking process before an individual engages in action. Undoubtfully, this skill is vital in influencing an individual to plan, monitor and evaluate his/her actions in daily life. In short, the proposed framework is essential in expanding the current knowledge terrain on psychology, which specifically provides a new perspective in understanding how the thinking process determines behavior.
  11. Isotopic ratio analysis of cattle tail hair: A potential tool in building the database for cow milk geographical traceability
    Behkami S, Zain SM, Gholami M, Bakirdere S
    Food Chem, 2017 Feb 15;217:438-444.
    PMID: 27664656 DOI: 10.1016/j.foodchem.2016.08.130
    The potential for the isotopic ratio analysis of cattle tail hair in determining the geographical origin of raw cow milk in Peninsular Malaysia had been investigated in this research using exploratory visualization. A significant positive correlation (p<0.0001) (n=54) was noticed between δ(13)C and δ(15)N in milk with that of hair which indicated that these matrices could be used in tracing the geographical origin of animal produce and tissues, and there is a possibility that hair could be used as a substitute in building the database for the geographical traceability of milk. It was also observed that both hair and milk isotopic ratio correlations exhibited separation between the northern and southern regions. The accuracy of using isotopic ratio in determining geographical discrimination had been clearly demonstrated when several commercial milk samples from the same regions under the study were correctly assigned to the appropriate geographical clusters.
  12. Fulltext A simple design for microwave assisted digestion vessel with low reagent consumption suitable for food and environmental samples
    Gholami M, Behkami S, Zain SM, Bakirdere S
    Sci Rep, 2016 11 17;6:37186.
    PMID: 27853264 DOI: 10.1038/srep37186
    The objective of this work is to prepare a cost-effective, low reagent consumption and high performance polytetrafluoroethylene (PTFE) vessel that is capable to work in domestic microwave for digesting food and environmental samples. The designed vessel has a relatively thicker wall compared to that of commercial vessels. In this design, eight vessels are placed in an acrylonitrile butadiene styrene (ABS) holder to keep them safe and stable. This vessel needs only 2.0 mL of HNO3 and 1.0 mL H2O2 to digest 100 mg of biological sample. The performance of this design is then evaluated with an ICP-MS instrument in the analysis of the several NIST standard reference material of milk 1849a, rice flour 1568b, spinach leave 1570a and Peach Leaves 1547 in a domestic microwave oven with inverter technology. Outstanding agreement to (SRM) values are observed by using the suggested power to time microwave program, which simulates the reflux action occurring in this closed vessel. Taking into account the high cost of commercial microwave vessels and the volume of chemicals needed for various experiments (8-10 mL), this simple vessel is cost effective and suitable for digesting food and environmental samples.
  13. Correlation between polar surface area and bioferroelectricity in DNA and RNA nucleobases
    Yam SC, Zain SM, Sanghiran Lee V, Chew KH
    Eur Phys J E Soft Matter, 2018 Jul 18;41(7):86.
    PMID: 30014219 DOI: 10.1140/epje/i2018-11696-5
    We have performed computational molecular modelling to study the polarization switching and hysteresis loop behaviours of DNA and RNA nucleobases using the PM3 semi-empirical quantum mechanical approaches. All the nucleobases: adenine (A), thymine (T), guanine (G), cytosine (C), and uracil (U) were modelled. Our study indicates that all the nucleobases exhibit a zero-field polarization due to the presence of polar atoms or molecules such as amidogen and carbonyl. The shape of polarization P versus an applied electric field E hysteresis loop is square, implying typical ferroelectrics behaviour. The total energy U as a function of an applied electric field E exhibits a butterfly-like loop. The presence of zero-field polarization and ferroelectrics hysteresis loop behaviours in nucleobases may support the hypothesis of the existence of bioferroelectricity in DNA and RNA. We also found an interesting relationship between the minimum electric field required for switching [Formula: see text] and the ratio of the topological polar surface area (TPSA) to the total surface area (TSA) of a nucleobase. In particular, the [Formula: see text] of a nucleobase is inversely proportional to the TPSA/TSA ratio. This work may provide useful information for understanding the possible existence of ferroelectricity in biomaterials.
  14. Determination of Relative Counterion Binding Constant to Cationic Micelles
    Khalid K, Noh MAM, Zain SM, Khan MN
    Top Curr Chem (Cham), 2017 Apr;375(2):45.
    PMID: 28357712 DOI: 10.1007/s41061-017-0132-9
    The efficiency of counterion affinity towards ionic micelles is often described in terms of the degree of counterion binding (β X ) to ionic micelles or the conventional ion-exchange constant ([Formula: see text]) or relative binding constant ([Formula: see text]) of X - and Br- counterions. This review describes the use of ionized phenyl salicylate ions, PSa-, as a new probe to determine [Formula: see text] values using a semiempirical spectrophotometric method. The value of [Formula: see text] is found to be comparable to reported values obtained using different probes by the semiempirical kinetic method as well as different physical methods. Application of semiempirical methods for calculation of [Formula: see text] or [Formula: see text] values involves an inherent assumption that these values are independent of the physicochemical characteristics of the probe molecule.
  15. Classification of cow milk using artificial neural network developed from the spectral data of single- and three-detector spectrophotometers
    Behkami S, Zain SM, Gholami M, Khir MFA
    Food Chem, 2019 Oct 01;294:309-315.
    PMID: 31126468 DOI: 10.1016/j.foodchem.2019.05.060
    Spectra data from two instruments (UV-Vis/NIR and FT-NIR) consisting of three and one detectors, respectively, were employed in order to discriminate the geographical origin of milk as a way to detect adulteration. Initially, principal component analysis (PCA) was used to see if clusters of milk from different origins are formed. Separation between samples of different origins were not observed with PCA, hence, feed-forward multi-layer perceptron artificial neural network (MLP-ANN) models were designed. ANN models were developed by changing the number of input variables and the best models were chosen based on high values of generalized R-square and entropy R-square, as well as small values of root mean square error (RMSE), mean absolute deviation (Mean Abs. Dev), and -loglikelihood while considering 100% classification rate. Based on the results, whether the spectra data was collected from a single or three detector instrument the same clustering was observed based on geographical origin.
  16. Fulltext Base Catalytic Approach: A Promising Technique for the Activation of Biochar for Equilibrium Sorption Studies of Copper, Cu(II) Ions in Single Solute System
    Hamid SBA, Chowdhury ZZ, Zain SM
    Materials (Basel), 2014 Apr 09;7(4):2815-2832.
    PMID: 28788595 DOI: 10.3390/ma7042815
    This study examines the feasibility of catalytically pretreated biochar derived from the dried exocarp or fruit peel of mangostene with Group I alkali metal hydroxide (KOH). The pretreated char was activated in the presence of carbon dioxide gas flow at high temperature to upgrade its physiochemical properties for the removal of copper, Cu(II) cations in single solute system. The effect of three independent variables, including temperature, agitation time and concentration, on sorption performance were carried out. Reaction kinetics parameters were determined by using linear regression analysis of the pseudo first, pseudo second, Elovich and intra-particle diffusion models. The regression co-efficient, R² values were best for the pseudo second order kinetic model for all the concentration ranges under investigation. This implied that Cu(II) cations were adsorbed mainly by chemical interactions with the surface active sites of the activated biochar. Langmuir, Freundlich and Temkin isotherm models were used to interpret the equilibrium data at different temperature. Thermodynamic studies revealed that the sorption process was spontaneous and endothermic. The surface area of the activated sample was 367.10 m²/g, whereas before base activation, it was only 1.22 m²/g. The results elucidated that the base pretreatment was efficient enough to yield porous carbon with an enlarged surface area, which can successfully eliminate Cu(II) cations from waste water.
  17. A case-control study and meta-analysis confirm glucokinase regulatory gene rs780094 is a risk factor for gestational diabetes mellitus
    Jamalpour S, Zain SM, Mosavat M, Mohamed Z, Omar SZ
    Gene, 2018 Apr 15;650:34-40.
    PMID: 29410004 DOI: 10.1016/j.gene.2018.01.091
    BACKGROUND: Although the influence of a common variant in the glucokinase regulatory gene (GCKR rs780094) in type 2 diabetes mellitus has been well documented, less data however, is available of its role in gestational diabetes mellitus (GDM). We carried out a case control study to assess the association between GCKR rs780094 and GDM in the Asian, and also a meta-analysis to further assess the strength of the association.

    METHODS: Demographic, clinical and genotype data were determined for 1122 women (267 cases and 855 controls) recruited from the University of Malaya Medical Centre in the Klang Valley, Kuala Lumpur. Relevant articles were identified from Pubmed, Embase, MEDLINE, and Web of Science. Extraction of data was carried out and summary estimates of the association between rs780094 and GDM were examined.

    RESULTS: The frequency of risk allele C was significantly higher in the cases than controls (OR 1.34, 95% CI 1.09-1.66, P = 0.006). The C allele was also associated with increased level of random 2-hour fasting plasma glucose and pregravid body mass index. Meta-analysis further confirmed the association of the GCKR rs780094 with GDM (OR 1.32, 95% CI 1.14-1.52, P = 0.0001).

    CONCLUSION: This study strongly suggests that GCKR rs780094-C is associated with increased risk of GDM.

  18. Cation-stimulated drug delivery via lipid assembly comprising macrocyclized disaccharides - A DFT study
    Mazlee MTF, Heidelberg T, Ariffin A, Zain SM
    Carbohydr Res, 2023 Oct;532:108923.
    PMID: 37598565 DOI: 10.1016/j.carres.2023.108923
    In the attempt to create a delivery system for an alkali-cation stimulated drug release, a computational study was conducted, aiming for the evaluation of synthetic access towards glycolipid crown ethers analogs and their potential for coordination-induced changes of packing constraints for molecular assemblies. The results disfavor amide-linkages for the creation of macrocycles around the inter-glycosidic bond of a disaccharide. Conformational changes upon cation coordination of the macrocycle decrease the intersection area for easily accessible macrocycles based on lactose. This leads to shrinking intersection areas upon alkali complexation. Maltose-based analogs, on the other hand, exhibited the targeted increase of the glycolipid intersection area and, hence, may be considered as a promising resource.
  19. The potential of some functional group compounds substituted 8-Manzamine A as RSK1 inhibitors: molecular docking and molecular dynamics simulations
    Zayed AOH, Altarabeen M, AlShamaileh E, Zain SM
    J Biomol Struct Dyn, 2024 Feb 06.
    PMID: 38319051 DOI: 10.1080/07391102.2024.2310792
    Cancer, an incurable global disease, demands urgent anti-cancer drug development. Marine alkaloids like Manzamine and its derivatives show promise as RSK inhibitors against cancer cell invasion. Replacing the hydrogen at the 8-position of Manzamine A with a hydroxyl group has been shown to significantly enhance its biological activity. In this article, we designed various functional group compounds (A1-A21) substituted 8-Manzamine A by docking, MM-GBSA, molecular dynamics (MD) simulation, and well-tempered metadynamics (WT-MetaD) simulations to evaluate their potential as RSK1 inhibitors. Ligands A1-A21 were docked in the RSK1 N-terminal kinase domain (PDB ID: 2Z7Q) using the Glide module. The calculation of binding energy was performed using Prime MM-GB/SA, while MD simulations were conducted with the Desmond module of Schrodinger suite 2023. Compound A5 exhibits the highest G-score (-7.01) compared to 8-Hydroxymanzamine A (-6.08). Additionally, compounds A6, A10, A12, A17, A11, A4, and A13 demonstrate increased activity against RSK1 when compared to both 8-Hydroxymanzamine A and Manzamine A. Residues LEU68, VAL76, LEU141, PHE143, LEU144, PHE150, ASP148, GLU191, and LEU194 of RSK1 protein play a key role in binding with ligands. An MD simulation of Compound A5 was carried out to explore the dynamic interactions within the protein-ligand complex. Furthermore, WT-MetaD simulations validated the docking study results and identified the most energetically favored conformations for the A5/RSK1 complex. Ligands A5, A6, A10, A12, A17, A11, A4, and A13, featuring diverse functional groups and good Glide scores, may have the potential for significant RSK1 activity and merit further development.Communicated by Ramaswamy H. Sarma.
  20. Fulltext Renin-Angiotensin System Gene Variants and Type 2 Diabetes Mellitus: Influence of Angiotensinogen
    Joyce-Tan SM, Zain SM, Abdul Sattar MZ, Abdullah NA
    J Diabetes Res, 2016;2016:2161376.
    PMID: 26682227 DOI: 10.1155/2016/2161376
    Genome-wide association studies (GWAS) have been successfully used to call for variants associated with diseases including type 2 diabetes mellitus (T2DM). However, some variants are not included in the GWAS to avoid penalty in multiple hypothetic testing. Thus, candidate gene approach is still useful even at GWAS era. This study attempted to assess whether genetic variations in the renin-angiotensin system (RAS) and their gene interactions are associated with T2DM risk. We genotyped 290 T2DM patients and 267 controls using three genes of the RAS, namely, angiotensin converting enzyme (ACE), angiotensinogen (AGT), and angiotensin II type 1 receptor (AGTR1). There were significant differences in allele frequencies between cases and controls for AGT variants (P = 0.05) but not for ACE and AGTR1. Haplotype TCG of the AGT was associated with increased risk of T2DM (OR 1.92, 95% CI 1.15-3.20, permuted P = 0.012); however, no evidence of significant gene-gene interactions was seen. Nonetheless, our analysis revealed that the associations of the AGT variants with T2DM were independently associated. Thus, this study suggests that genetic variants of the RAS can modestly influence the T2DM risk.
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