Displaying publications 1 - 20 of 28 in total

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  1. Ismail Y, Muhamad A
    Med J Malaysia, 2003 Aug;58(3):345-9.
    PMID: 14750373
    We present 11 cases to illustrate the protean presentations of gastrointestinal tuberculosis. The patients presented with perianal fistula, appendicitis, ascites, rectal, intestinal or gastric 'growth', "ulcerative colitis", or recurrent anemia. In some of these cases there was no conclusive proof of infection with Mycobacterium tuberculosis but they responded well to empirical treatment with anti-tuberculous therapy. These cases illustrate that because signs and symptoms of intestinal tuberculosis are non-specific and even histology can be misleading, the diagnosis of gastrointestinal tuberculosis requires a high index of suspicion. A therapeutic trial of antituberculous drugs should be considered for patients with a high clinical suspicion of tuberculosis.
  2. Muhamad A, Syihab AH, Ibrahim AH
    Sci Eng Ethics, 2020 Apr;26(2):1053-1066.
    PMID: 32048138 DOI: 10.1007/s11948-020-00192-7
    Environmental sustainability is one of the contemporary discourses that has abundant values embedded in the Quran and Sunnah teachings. Islam gives great emphasis on environment as it is preserved and protected under the Maqasid al-Shariah (Objectives of the Islamic Law). The general outlook of Quranic paradigm on utilizing natural environment is based on prohibition of aggression and misuse. It is likewise founded on the construction and sustainable use. Thus, this article attempts to elaborate key concepts of the Quran and Sunnah teachings that reveal imperative values for environmental sustainability. Research method employs in this paper is an analytical study of Quranic verses with special highlights of tafsir bi al-ma'thur (explanation based upon traditions), tafsir bi al-ra'yi (explanation based on reasoning), and historical narrative. In short, this paper brings to light the relevance of classical and contemporary works of Quran and Sunnah studies that have meticulous values for shaping the better world of human-nature's interaction.
  3. Ramli AB, Rafii MY, Latif MA, Saleh GB, Omar OB, Puteh AB
    J Sci Food Agric, 2016 Mar;96(5):1593-600.
    PMID: 25982124 DOI: 10.1002/jsfa.7260
    Genetic analysis using generation mean analysis is a tool for designing the most appropriate breeding approaches to developing varieties of rice. It estimates the gene actions that control quantitative traits, as well as the additive, dominance and epistatic effects. This study was conducted using three rice populations that were derived from parental lines with different amylose content. The aim was to partition the gene actions using generation mean analysis for the selected populations.
  4. Rostam MA, Piva TJ, Rezaei HB, Kamato D, Little PJ, Zheng W, et al.
    Clin Exp Pharmacol Physiol, 2015 Feb;42(2):117-24.
    PMID: 25377120 DOI: 10.1111/1440-1681.12335
    Peptidyl-prolyl cis/trans isomerases (PPIases) are a conserved group of enzymes that catalyse the conversion between cis and trans conformations of proline imidic peptide bonds. These enzymes play critical roles in regulatory mechanisms of cellular function and pathophysiology of disease. There are three different classes of PPIases and increasing interest in the development of specific PPIase inhibitors. Cyclosporine A, FK506, rapamycin and juglone are known PPIase inhibitors. Herein, we review recent advances in elucidating the role and regulation of the PPIase family in vascular disease. We focus on peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1), an important member of the PPIase family that plays a role in cell cycle progression, gene expression, cell signalling and cell proliferation. In addition, Pin1 may be involved in atherosclerosis. The unique role of Pin1 as a molecular switch that impacts on multiple downstream pathways necessitates the evaluation of a highly specific Pin1 inhibitor to aid in potential therapeutic drug discovery.
  5. Rostam MA, Kamato D, Piva TJ, Zheng W, Little PJ, Osman N
    Cell Signal, 2016 08;28(8):956-66.
    PMID: 27153775 DOI: 10.1016/j.cellsig.2016.05.002
    Hyperelongation of glycosaminoglycan chains on proteoglycans facilitates increased lipoprotein binding in the blood vessel wall and the development of atherosclerosis. Increased mRNA expression of glycosaminoglycan chain synthesizing enzymes in vivo is associated with the development of atherosclerosis. In human vascular smooth muscle, transforming growth factor-β (TGF-β) regulates glycosaminoglycan chain hyperelongation via ERK and p38 as well as Smad2 linker region (Smad2L) phosphorylation. In this study, we identified the involvement of TGF-β receptor, intracellular serine/threonine kinases and specific residues on transcription factor Smad2L that regulate glycosaminoglycan synthesizing enzymes. Of six glycosaminoglycan synthesizing enzymes, xylosyltransferase-1, chondroitin sulfate synthase-1, and chondroitin sulfotransferase-1 were regulated by TGF-β. In addition ERK, p38, PI3K and CDK were found to differentially regulate mRNA expression of each enzyme. Four individual residues in the TGF-β receptor mediator Smad2L can be phosphorylated by these kinases and in turn regulate the synthesis and activity of glycosaminoglycan synthesizing enzymes. Smad2L Thr220 was phosphorylated by CDKs and Smad2L Ser250 by ERK. p38 selectively signalled via Smad2L Ser245. Phosphorylation of Smad2L serine residues induced glycosaminoglycan synthesizing enzymes associated with glycosaminoglycan chain elongation. Phosphorylation of Smad2L Thr220 was associated with XT-1 enzyme regulation, a critical enzyme in chain initiation. These findings provide a deeper understanding of the complex signalling pathways that contribute to glycosaminoglycan chain modification that could be targeted using pharmacological agents to inhibit the development of atherosclerosis.
  6. Bawadikji AA, Teh CH, Kader MABSA, Sulaiman SAS, Ibrahim B
    Curr Pharm Biotechnol, 2017;18(9):740-747.
    PMID: 29110602 DOI: 10.2174/1389201018666171103141828
    BACKGROUND: Warfarin, an anticoagulant medication, is prescribed regularly despite of its bleeding tendency for the prevention and/or treatment of various thromboembolic conditions, such as deep vein thrombosis, and complications associated with atrial fibrillation, and myocardial infarction, but because of its narrow therapeutic window, it has a lot of interactions with drugs and diet.

    METHODS: Warfarin relies on regular monitoring of International Normalized Ratio which is a standardized test to measure prothrombin time and appropriate dose adjustment. Pharmacometabonomics is a novel scientific field which deals with identification and quantification of the metabolites present in the metabolome using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR). Pharmacometabonomics helps to indicate perturbation in the levels of metabolites in the cells and tissues due to drug or ingestion of any substance. NMR is one of the most widely-used spectroscopic techniques in metabolomics because of its reproducibility and speed.

    RESULTS: There are many factors that influence the metabolism of warfarin, making changes in drug dosage common, and clinical factors like drug-drug interactions, dietary interactions and age explain for the most part the variability in warfarin dosing. Some studies have showed that pharmacogenetic testing for warfarin dosing does not improve health outcomes, and around 26% of the variation in warfarin dose requirements remains unexplained yet.

    CONCLUSION: Many recent pharmacometabonomics studies have been conducted to identify novel biomarkers of drug therapies such as paracetamol, aspirin and simvastatin. Thus, a technique such as NMR based pharmacometabonomics to find novel biomarkers in plasma and urine might be useful to predict warfarin outcome.

  7. Izma MKO, Zulkharnain I, Ramli B, Muhamad AR, Harwant S
    Med J Malaysia, 2003 Mar;58(1):105-10.
    PMID: 14556334
    SCIWORA or Spinal Cord Injury Without Radiological Abnormality; is a pre-MRI term that includes injuries to the spinal cord in the absence of radiological (plain radiographs, tomographs and CT scans) evidence of injury to the spinal column or cord. It occurs in skeletally immature spines because of the inherent plasticity of the bony structures in this age group. The prognosis is dependent on the extent of cord damage, and the role of active management is limited. A high index of suspicion is needed to establish a diagnosis. This diagnostic accuracy can be improved with the free availability of MRI scanning for the spines. We describe three cases of SCIWORA with a minimum follow-up of three years and a review of current literature.
  8. Chan KH, Muhamad A, Hayati F, Azizan N, Andee DZ
    ANZ J Surg, 2021 Jul;91(7-8):1620-1622.
    PMID: 33351236 DOI: 10.1111/ans.16508
  9. Mawang CI, Lim YY, Ong KS, Muhamad A, Lee SM
    J Appl Microbiol, 2017 Nov;123(5):1148-1159.
    PMID: 28869803 DOI: 10.1111/jam.13578
    AIMS: The potential of Dicranopteris linearis leaves' extract and its bioactive components were investigated for the first time for its disrupting ability against Staphylococcus aureus biofilms.

    METHODS AND RESULTS: The leaves of D. linearis were subjected to sonication-assisted extraction using hexane (HEX), dichloromethane, ethyl acetate and methanol (MeOH). It was found that only the MeOH fraction exhibited antimicrobial activity using broth microdilution assay; while all four fractions do not exhibit biofilm inhibition activity against S. aureusATCC 6538P, S. aureusATCC 43300, S. aureusATCC 33591 and S. aureusATCC 29213 using crystal violet assay. Among the four fractions tested, only the HEX fraction showed biofilm disrupting ability, with 60-90% disruption activity at 5 mg ml-1against all four S. aureus strains tested. Bioassay-guided purification of the active fraction has led to the isolation of α-tocopherol. α-Tocopherol does not affect the cells within the biofilms but instead affects the biofilm matrix in order to disrupt S. aureus biofilms.

    CONCLUSIONS: α-Tocopherol was identified to be the bioactive component of D. linearis with disruption activity against S. aureus biofilm matrix.

    SIGNIFICANCE AND IMPACT OF THE STUDY: The use of α-tocopherol as a biofilm disruptive agent might potentially be useful to treat biofilm-associated infections in the future.

  10. Rostam MA, Shajimoon A, Kamato D, Mitra P, Piva TJ, Getachew R, et al.
    J. Pharmacol. Exp. Ther., 2018 04;365(1):156-164.
    PMID: 29438988 DOI: 10.1124/jpet.117.244483
    Transforming growth factor-β (TGF-β) is a pleiotropic growth factor implicated in the development of atherosclerosis for its role in mediating glycosaminoglycan (GAG) chain hyperelongation on the proteoglycan biglycan, a phenomenon that increases the binding of atherogenic lipoproteins in the vessel wall. Phosphorylation of the transcription factor Smad has emerged as a critical step in the signaling pathways that control the synthesis of biglycan, both the core protein and the GAG chains. We have used flavopiridol, a well-known cyclin-dependent kinase inhibitor, to study the role of linker region phosphorylation in the TGF-β-stimulated synthesis of biglycan. We used radiosulfate incorporation and SDS-PAGE to assess proteoglycan synthesis, real-time polymerase chain reaction to assess gene expression, and chromatin immunoprecipitation to assess the binding of Smads to the promoter region of GAG Synthesizing genes. Flavopiridol blocked TGF-β-stimulated synthesis of mRNA for the GAG synthesizing enzymes, and chondroitin 4-sulfotransferase (C4ST-1), chondroitin sulfate synthase-1 (ChSy-1) and TGF-β-mediated proteoglycans synthesis as well as GAG hyperelongation. Flavopiridol blocked TGF-β-stimulated Smad2 phosphorylation at both the serine triplet and the isolated threonine residue in the linker region. The binding of Smad to the promoter region of the C4ST-1 and ChSy-1 genes was stimulated by TGF-β, and this response was blocked by flavopiridol, demonstrating that linker region phosphorylated Smad can pass to the nucleus and positively regulate transcription. These results demonstrate the validity of the kinases, which phosphorylate the Smad linker region as potential therapeutic target(s) for the development of an agent to prevent atherosclerosis.
  11. Ahrens I, Averkov O, Zúñiga EC, Fong AYY, Alhabib KF, Halvorsen S, et al.
    Clin Cardiol, 2019 Oct;42(10):1028-1040.
    PMID: 31317575 DOI: 10.1002/clc.23232
    Clinical guidelines for the treatment of patients with non-ST-segment elevation myocardial infarction (NSTEMI) recommend an invasive strategy with cardiac catheterization, revascularization when clinically appropriate, and initiation of dual antiplatelet therapy regardless of whether the patient receives revascularization. However, although patients with NSTEMI have a higher long-term mortality risk than patients with ST-segment elevation myocardial infarction (STEMI), they are often treated less aggressively; with those who have the highest ischemic risk often receiving the least aggressive treatment (the "treatment-risk paradox"). Here, using evidence gathered from across the world, we examine some reasons behind the suboptimal treatment of patients with NSTEMI, and recommend approaches to address this issue in order to improve the standard of healthcare for this group of patients. The challenges for the treatment of patients with NSTEMI can be categorized into four "P" factors that contribute to poor clinical outcomes: patient characteristics being heterogeneous; physicians underestimating the high ischemic risk compared with bleeding risk; procedure availability; and policy within the healthcare system. To address these challenges, potential approaches include: developing guidelines and protocols that incorporate rigorous definitions of NSTEMI; risk assessment and integrated quality assessment measures; providing education to physicians on the management of long-term cardiovascular risk in patients with NSTEMI; and making stents and antiplatelet therapies more accessible to patients.
  12. Muhamad A, Ho KL, Rahman MB, Uhrín D, Tan WS
    Chem Biol Drug Des, 2013 Jun;81(6):784-94.
    PMID: 23405984 DOI: 10.1111/cbdd.12120
    A specific ligand targeting the immunodominant region of hepatitis B virus is desired in neutralizing the infectivity of the virus. In a previous study, a disulfide constrained cyclic peptide cyclo S(1) ,S(9) Cys-Glu-Thr-Gly-Ala-Lys-Pro-His-Cys (S(1) , S(9) -cyclo-CETGAKPHC) was isolated from a phage displayed cyclic peptide library using an affinity selection method against hepatitis B surface antigen. The cyclic peptide binds tightly to hepatitis B surface antigen with a relative dissociation constant (KD (rel) ) of 2.9 nm. The binding site of the peptide was located at the immunodominant region on hepatitis B surface antigen. Consequently, this study was aimed to elucidate the structure of the cyclic peptide and its interaction with hepatitis B surface antigen in silico. The solution structure of this cyclic peptide was solved using (1) H, (13) C, and (15) N NMR spectroscopy and molecular dynamics simulations with NMR-derived distance and torsion angle restraints. The cyclic peptide adopted two distinct conformations due to the isomerization of the Pro residue with one structured region in the ETGA sequence. Docking studies of the peptide ensemble with a model structure of hepatitis B surface antigen revealed that the cyclic peptide can potentially be developed as a therapeutic drug that inhibits the virus-host interactions.
  13. Muhamad A, Ho KL, Rahman MB, Tejo BA, Uhrín D, Tan WS
    Org Biomol Chem, 2015 Jul 28;13(28):7780-9.
    PMID: 26100394 DOI: 10.1039/c5ob00449g
    Hepatitis B virus (HBV) infection remains a health problem globally despite the availability of effective vaccines. In the assembly of the infectious virion, both the preS and S regions of the HBV large surface antigen (L-HBsAg) interact synergistically with the viral core antigen (HBcAg). Peptides preS and S based on the L-HBsAg were demonstrated as potential inhibitors to block the viral assembly. Therefore, the objectives of this study were to determine the solution structures of these peptides and study their interactions with HBcAg. The solution structures of these peptides were solved using (1)H, (13)C, and (15)N NMR spectroscopy. Peptide preS has several structured regions of β-turns at Ser7-Pro8-Pro9, Arg11-Thr12-Thr13 and Ser22-Thr23-Thr24 sequences whereas peptide S has only one structured region observed at Ser3-Asn4-His5. Both peptides contain bend-like structures surrounding the turn structures. Docking studies revealed that both peptides interacted with the immunodominant region of HBcAg located at the tip of the viral capsid spikes. Saturation Transfer Difference (STD) NMR experiments identified several aromatic residues in peptides preS and S that interact with HBcAg. This study provides insights into the contact regions of L-HBsAg and HBcAg at atomic resolution which can be used to design antiviral agents that inhibit HBV morphogenesis.
  14. Muhamad A, Johan S, Khairuddin A, Hayati F, Payus AO, Zainal Abidin ZA
    Urol Case Rep, 2021 Jan;34:101448.
    PMID: 33088720 DOI: 10.1016/j.eucr.2020.101448
    Suprapubic catheterization (SPC) is a temporary measure to relieve acute urinary retention (AUR). Despite being effective, it can lead to complications such as colon perforation, haematuria, and bladder wall spasm. We present a 52-year-old lady with cystofix for underlying urethral stricture presented with AUR. A new SPC was inserted to drain the urine. However, the SPC had looped and entangled with her cystofix, and laparoscopic removal of cystofix and insertion of a new SPC was done. In conclusion, trapped cystofix to the SPC tube is a potential complication during SPC insertion that can be avoided with appropriate care.
  15. Begum SZ, Nizam NSM, Muhamad A, Saiman MI, Crouse KA, Abdul Rahman MB
    PLoS One, 2020;15(11):e0238147.
    PMID: 33147237 DOI: 10.1371/journal.pone.0238147
    Laccases, oxidative copper-enzymes found in fungi and bacteria were used as the basis in the design of nona- and tetrapeptides. Laccases are known to be excellent catalysts for the degradation of phenolic xenobiotic waste. However, since solvent extraction of laccases is environmentally-unfriendly and yields obtained are low, they are less preferred compared to synthetic catalysts. The histidine rich peptides were designed based on the active site of laccase extracted from Trametes versicolor through RCSB Protein Data Bank, LOMETS and PyMol software. The peptides were synthesized using Fmoc-solid phase peptide synthesis (SPPS) with 30-40% yield. These peptides were purified and characterized using LC-MS (purities >75%), FTIR and NMR spectroscopy. Synthesized copper(II)-peptides were crystallized and then analyzed spectroscopically. Their structures were elucidated using 1D and 2D NMR. Standards (o,m,p-cresol, 2,4-dichlorophenol) catalysed using laccase from Trametes versicolor (0.66 U/mg) were screened under different temperatures and stirring rate conditions. After optimizing the degradation of the standards with the best reaction conditions reported herein, medications with phenolic and aromatic structures such as ibuprofen, paracetamol (acetaminophen), salbutamol, erythromycin and insulin were screened using laccase (positive control), apo-peptides and copper-peptides. Their activities evaluated using GC-MS, were compared with those of peptide and copper-peptide catalysts. The tetrapeptide was found to have the higher degradation activity towards salbutamol (96.8%) compared with laccase at 42.8%. Ibuprofen (35.1%), salbutamol (52.9%) and erythromycin (49.7%) were reported to have the highest degradation activities using Cu-tetrapeptide as catalyst when compared with the other medications. Consequently, o-cresol (84%) was oxidized by Tp-Cu while the apo-peptides failed to oxidize the cresols. Copper(II)-peptides were observed to have higher catalytic activity compared to their parent peptides and the enzyme laccase for xenobiotic degradation.
  16. Wong CL, Yong CY, Muhamad A, Syahir A, Omar AR, Sieo CC, et al.
    Appl Microbiol Biotechnol, 2018 May;102(9):4131-4142.
    PMID: 29564523 DOI: 10.1007/s00253-018-8921-9
    Foot-and-mouth disease (FMD) is a major threat to the livestock industry worldwide. Despite constant surveillance and effective vaccination, the perpetual mutations of the foot-and-mouth disease virus (FMDV) pose a huge challenge to FMD diagnosis. The immunodominant region of the FMDV VP1 protein (residues 131-170) displayed on phage T7 has been used to detect anti-FMDV in bovine sera. In the present study, the functional epitope was further delineated using amino acid sequence alignment, homology modelling and phage display. Two highly conserved regions (VP1145-152 and VP1159-170) were identified among different FMDV serotypes. The coding regions of these two epitopes were fused separately to the T7 genome and displayed on the phage particles. Interestingly, chimeric phage displaying the VP1159-170 epitope demonstrated a higher antigenicity than that displaying the VP1131-170 epitope. By contrast, phage T7 displaying the VP1145-152 epitope did not react significantly with the anti-FMDV antibodies in vaccinated bovine sera. This study has successfully identified a smaller functional epitope, VP1159-170, located at the C-terminal end of the structural VP1 protein. The phage T7 displaying this shorter epitope is a promising diagnostic reagent to detect anti-FMDV antibodies in vaccinated animals.
  17. Lee FK, Krishnan P, Muhamad A, Low YY, Kam TS, Ting KN, et al.
    Nat Prod Res, 2021 Mar 22.
    PMID: 33749454 DOI: 10.1080/14786419.2021.1903005
    A concise synthesis of the 1,4-diarylbutanoid-phenethylamine alkaloids, schwarzinicines A (1) and B (2), recently isolated from Ficus schwarzii, is reported. Key steps include a Claisen condensation to assemble the 1,4-diaryl-2-butanone intermediate, followed by a reductive amination to furnish the core skeleton of the target compounds. The overall synthetic yields of 1 and 2 were 9.1% and 3.5%, respectively. Synthetic (-)-1, (+)-1 and (±)-1 exhibited comparable vasorelaxation as natural schwarzinicine A on rat isolated aortic rings, suggesting that the observed vasorelaxant effects were not influenced by the chirality at C-2.
  18. Muhamad A, Hayati F, Azizan N, Sahid Nik Lah NA, Andee DZ
    ANZ J Surg, 2021 04;91(4):763-764.
    PMID: 33847052 DOI: 10.1111/ans.16536
  19. Achour M, Muhamad A, Syihab AH, Mohd Nor MR, Mohd Yusoff MYZ
    J Relig Health, 2021 Feb;60(1):202-220.
    PMID: 31079348 DOI: 10.1007/s10943-019-00834-6
    This study examines how Salat (prayer) in Islam moderates the relationship between job stress and life satisfaction among Muslim nursing staff. The researchers sampled 335 nursing staff employed at the University of Malaya Medical Centre in Kuala Lumpur, Malaysia. Their ages ranged from 21 to 60 years. The findings indicate the job stress was associated negatively with life satisfaction; there is a strong positive and significant correlation, respectively, between Salat and life satisfaction and that Salat reduces stress and increases the life satisfaction of Muslim nurses. Thus, Salat has a moderating effect on job stress and life satisfaction of Muslim nurses.
  20. Behan AA, Akhtar MT, Loh TC, Fakurazi S, Kaka U, Muhamad A, et al.
    Foods, 2021 May 19;10(5).
    PMID: 34069633 DOI: 10.3390/foods10051133
    The supplementation of rumen bypass fat (RBF) has remained one of the preferred approaches used to decrease undesirable saturated fatty acids (FA) and increase beneficial unsaturated FA in the meat. This study was planned to evaluate the influences of rumen bypass fats on meat quality, fatty acid and metabolic profiles in male Dorper sheep (n = 36) with 24.66 ± 0.76 kg (mean ± standard error) initial body weight. Treatment comprised a basal diet (30:70 rice straw to concentrate) with no added RBF as a control (CON), basal diet with prilled fat (PF), basal diet with prilled fat plus lecithin (PFL) and basal diet with calcium soap of palm fatty acids (CaS). The findings revealed that cooking loss, drip loss and shear force in longissimus dorsi (LD) muscle were not affected by RBF supplementation, while meat pH was significantly higher in the CaS on aging day 1. However, the diet supplemented with prilled fat and lecithin modified the meat's fatty acid profile significantly by increasing unsaturated fatty acids and decreasing saturated fats. The relative quantification of the major differentiating metabolites found in LD muscle of sheep showed that total cholesterol, esterified cholesterol, choline, glycerophosphocholine and glycerophospholipids were significantly lower in CaS and PFL diets, while glycerol and sphingomyelin were significantly higher in CaS and PFL diets. Most of the metabolites in the liver did not show any significant difference. Based on our results, the supplementation of protected fats did not have a negative influence on meat quality and the meat from Dorper sheep fed prilled fat with lecithin contained more healthy fatty acids compared to other diets.
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