Displaying publications 21 - 40 of 198 in total

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  1. Loo SS, Blake DP, Mohd-Adnan A, Mohamed R, Wan KL
    Parasitology, 2010 Jul;137(8):1169-77.
    PMID: 20233491 DOI: 10.1017/S0031182010000119
    Limitations with current chemotherapeutic and vaccinal control of coccidiosis caused by Eimeria species continue to prompt development of novel controls, including the identification of new drug targets. Glucose-6-phosphate isomerase (G6-PI) has been proposed as a valid drug target for many protozoa, although polymorphism revealed by electrophoretic enzyme mobility has raised doubts for Eimeria. In this study we identified and sequenced the Eimeria tenella G6-PI orthologue (EtG6-PI) from the reference Houghton strain and confirmed its position within the prevailing taxonomic hierarchy, branching with the Apicomplexa and Plantae, distinct from the Animalia including the host, Gallus gallus. Comparison of the deduced 1647 bp EtG6-PI coding sequence with the 9016 bp genomic locus revealed 15 exons, all of which obey the intron-AG-/exon/-GT-intron splicing rule. Comparison with the Weybridge and Wisconsin strains revealed the presence of 33 single nucleotide polymorphisms (SNPs) and 14 insertion/deletion sites. Three SNPs were exonic and all yielded non-synonymous substitutions. Preliminary structural predictions suggest little association between the coding SNPs and key G6-PI catalytic residues or residues thought to be involved in the coordination of the G6-PI's substrate phosphate group. Thus, the significant polymorphism from its host orthologue and minimal intra-specific polymorphism suggest G6-PI remains a valid anti-coccidial drug target.
  2. Ling KH, Loo SS, Rosli R, Shamsudin MN, Mohamed R, Wan KL
    In Silico Biol. (Gedrukt), 2007;7(1):115-21.
    PMID: 17688436
    Phosphatidylinositol 4-phosphate 5-kinases (PIP5Ks) play diverse roles in the cellular biology of many organisms, including signal transduction, secretion and vesicular trafficking, and regulation of cytoskeleton assembly. Discovery of the PIP5K gene in Eimeria tenella may shed light on its role in the biology of this avian protozoan, and afford further understanding of the cell-host interaction, particularly during the invasion process. In this study, we report the identification of the PIP5K coding region in the genome sequence of Eimeria tenella using in silico gene prediction approaches. Prediction of the PIP5K coding sequence was confirmed by mapping the full-length cDNA sequence, generated via the Rapid Amplification of cDNA Ends (RACE) method, to the genomic sequence. The putative PIP5K gene of Eimeria tenella is located on the complementary strand of the E1080B12.b1 contig, and comprises 12 exons. Further analysis showed that the coding region spans from exon 1 to exon 7, with all exons obeying the adopted 'gt...ag' splicing rule of intronic sequences. Consensus of the hexameric 5' donor-splice site was deduced as GTRDBB... and the consensus for the 3' acceptor-splice sites as ...BHDYAG. The gene encodes a 252-amino acid residue protein. Domain search and protein fold recognition analyses provide compelling evidences that the deduced protein is a PIP5K.
  3. Lee XW, Mat-Isa MN, Mohd-Elias NA, Aizat-Juhari MA, Goh HH, Dear PH, et al.
    PLoS One, 2016;11(12):e0167958.
    PMID: 27977777 DOI: 10.1371/journal.pone.0167958
    Rafflesia is a biologically enigmatic species that is very rare in occurrence and possesses an extraordinary morphology. This parasitic plant produces a gigantic flower up to one metre in diameter with no leaves, stem or roots. However, little is known about the floral biology of this species especially at the molecular level. In an effort to address this issue, we have generated and characterised the transcriptome of the Rafflesia cantleyi flower, and performed a comparison with the transcriptome of its floral bud to predict genes that are expressed and regulated during flower development. Approximately 40 million sequencing reads were generated and assembled de novo into 18,053 transcripts with an average length of 641 bp. Of these, more than 79% of the transcripts had significant matches to annotated sequences in the public protein database. A total of 11,756 and 7,891 transcripts were assigned to Gene Ontology categories and clusters of orthologous groups respectively. In addition, 6,019 transcripts could be mapped to 129 pathways in Kyoto Encyclopaedia of Genes and Genomes Pathway database. Digital abundance analysis identified 52 transcripts with very high expression in the flower transcriptome of R. cantleyi. Subsequently, analysis of differential expression between developing flower and the floral bud revealed a set of 105 transcripts with potential role in flower development. Our work presents a deep transcriptome resource analysis for the developing flower of R. cantleyi. Genes potentially involved in the growth and development of the R. cantleyi flower were identified and provide insights into biological processes that occur during flower development.
  4. Ling KH, Rajandream MA, Rivailler P, Ivens A, Yap SJ, Madeira AM, et al.
    Genome Res, 2007 Mar;17(3):311-9.
    PMID: 17284678
    Eimeria tenella is an intracellular protozoan parasite that infects the intestinal tracts of domestic fowl and causes coccidiosis, a serious and sometimes lethal enteritis. Eimeria falls in the same phylum (Apicomplexa) as several human and animal parasites such as Cryptosporidium, Toxoplasma, and the malaria parasite, Plasmodium. Here we report the sequencing and analysis of the first chromosome of E. tenella, a chromosome believed to carry loci associated with drug resistance and known to differ between virulent and attenuated strains of the parasite. The chromosome--which appears to be representative of the genome--is gene-dense and rich in simple-sequence repeats, many of which appear to give rise to repetitive amino acid tracts in the predicted proteins. Most striking is the segmentation of the chromosome into repeat-rich regions peppered with transposon-like elements and telomere-like repeats, alternating with repeat-free regions. Predicted genes differ in character between the two types of segment, and the repeat-rich regions appear to be associated with strain-to-strain variation.
  5. Wait S, Kell E, Hamid S, Muljono DH, Sollano J, Mohamed R, et al.
    Lancet Gastroenterol Hepatol, 2016 11;1(3):248-255.
    PMID: 28404097 DOI: 10.1016/S2468-1253(16)30031-0
    In 2015, the Coalition to Eradicate Viral Hepatitis in Asia Pacific gathered leading hepatitis experts from Bangladesh, India, Indonesia, Malaysia, Pakistan, the Philippines, and Thailand to discuss common challenges to the burden posed by hepatitis B virus (HBV) and hepatitis C virus (HCV), to learn from each other's experience, and identify sustainable approaches. In this report, we summarise these discussions. Countries differ in their policy responses to HBV and HCV; however, substantial systemic, cultural, and financial barriers to achievement of elimination of these infections persist in all countries. Common challenges to elimination include limited availability of reliable epidemiological data; insufficient public awareness of risk factors and modes of transmission, leading to underdiagnosis; high rates of transmission through infected blood products, including in medical settings; limited access to care for people who inject drugs; prevailing stigma and discrimination against people infected with viral hepatitis; and financial barriers to treatment and care. Despite these challenges, promising examples of effective programmes, public-private initiatives, and other innovative approaches are evident in all countries we studied in Asia Pacific. The draft WHO Global Health Sector Strategy on Viral Hepatitis 2016-21 provides a solid framework upon which governments can build their local strategies towards viral hepatitis. However, greater recognition by national governments and the international community of the urgency to comprehensively tackle both HBV and HCV are still needed. In all countries, strategic plans and policy goals need to be translated into resources and concrete actions, with national governments at the helm, to enable a sustainable response to the rising burden of hepatitis B and C in all countries.
  6. Jamshed W, Eid MR, Nisar KS, Nasir NAAM, Edacherian A, Saleel CA, et al.
    Sci Rep, 2021 Aug 13;11(1):16500.
    PMID: 34389786 DOI: 10.1038/s41598-021-96040-0
    The current investigation aims to examine heat transfer as well as entropy generation analysis of Powell-Eyring nanofluid moving over a linearly expandable non-uniform medium. The nanofluid is investigated in terms of heat transport properties subjected to a convectively heated slippery surface. The effect of a magnetic field, porous medium, radiative flux, nanoparticle shapes, viscous dissipative flow, heat source, and Joule heating are also included in this analysis. The modeled equations regarding flow phenomenon are presented in the form of partial-differential equations (PDEs). Keller-box technique is utilized to detect the numerical solutions of modeled equations transformed into ordinary-differential equations (ODEs) via suitable similarity conversions. Two different nanofluids, Copper-methanol (Cu-MeOH) as well as Graphene oxide-methanol (GO-MeOH) have been taken for our study. Substantial results in terms of sundry variables against heat, frictional force, Nusselt number, and entropy production are elaborate graphically. This work's noteworthy conclusion is that the thermal conductivity in Powell-Eyring phenomena steadily increases in contrast to classical liquid. The system's entropy escalates in the case of volume fraction of nanoparticles, material parameters, and thermal radiation. The shape factor is more significant and it has a very clear effect on entropy rate in the case of GO-MeOH nanofluid than Cu-MeOH nanofluid.
  7. Lee SY, Ng WL, Mohamed R, Terhem R
    Mitochondrial DNA B Resour, 2018 Oct 29;3(2):1120-1121.
    PMID: 33474439 DOI: 10.1080/23802359.2018.1519382
    Known for its valuable agarwood, Aquilaria malaccensis Lam. is an evergreen tropical forest tree species endemic to the Indo-malesian region. Indiscriminate damaging and harvesting of the trees in the wild have resulted in it being listed in the CITES Appendix II for controlled trade and in the IUCN Red List as 'Vulnerable (VU)'. In this study, the complete chloroplast genome of A. malaccensis was assembled using data from high-throughput Illumina sequencing. The chloroplast genome was 174,832 bp in size, which included two inverted repeat regions of 42,091 bp each, separated by a large single copy region of 87,302 bp and a small single copy region of 3,348 bp. A total of 139 genes were predicted, including 39 tRNA, 8 rRNA, and 92 protein-coding genes. Phylogenetic analysis placed A. malaccensis within the family Thymelaeaceae. The chloroplast genome sequence of A. malaccensis offers a useful resource for future studies on the taxonomy and conservation of the threatened Aquilaria trees.
  8. Zeti AM, Shamsir MS, Tajul-Arifin K, Merican AF, Mohamed R, Nathan S, et al.
    PLoS Comput Biol, 2009 Aug;5(8):e1000457.
    PMID: 19714208 DOI: 10.1371/journal.pcbi.1000457
  9. Lee MH, Ahn SH, Chan HLY, Choudhry A, Alvani Gani R, Mohamed R, et al.
    J Viral Hepat, 2022 02;29(2):156-170.
    PMID: 34817896 DOI: 10.1111/jvh.13636
    There are limited data to provide better understanding of the knowledge/awareness of general population towards liver health in Asia. We sought to identify the knowledge gaps and attitudes towards liver health and liver diseases as well as evaluate associated individual-level and macro-level factors based on contextual analysis. An online survey assessing knowledge, awareness and attitudes towards liver health and disease was conducted among 7500 respondents across 11 countries/territories in Asia. A liver index was created to measure the respondents' knowledge level and the degree of awareness and attitudes. Multilevel logistic regression was performed to identify individual factors and contextual effects that were associated with liver index. The overall liver index (0-100-point scale) was 62.4 with 6 countries/territories' liver indices greater than this. In the multilevel model, the inclusion of geographical information could explain for 9.6% of the variation. Residing in a country/territory with higher HBV prevalence (80% IOR: 1.20-2.79) or higher HCV death rate (80% IOR: 1.35-3.13) increased the individual probability of obtaining a high overall liver index. Individual factors like age, gender, education, household income, disease history and health screening behaviour were also associated with liver index (all p-values<0.001). The overall liver index was positively associated with the two macro-level factors viz. HBV prevalence and HCV death rate. There is a need to formulate policies especially in regions of lower HBV prevalence and HCV death rate to further improve the knowledge, awareness and attitudes of the general public towards liver diseases.
  10. Mohamed R, Yip C, Singh S
    Eur J Gastroenterol Hepatol, 2023 Jul 01;35(7):742-752.
    PMID: 37161976 DOI: 10.1097/MEG.0000000000002548
    BACKGROUND: Viral hepatitis B and C (HBV, HCV) and non-alcoholic fatty liver disease (NAFLD) are the commonest etiologies of liver-related deaths in Malaysia. Herein, this study aims to explore and understand the knowledge and attitudes of the public toward liver-related health and diseases in Malaysia.

    METHODS: A cross-sectional, self-reported, web-based questionnaire was conducted among 500 adults between February and March 2020. Questionnaire items pertained to the knowledge and attitudes toward liver-related health and diseases.

    RESULTS: Half of the respondents were aged ≥35 years and 52.0% were males. Gaps in knowledge included the lack of awareness of different types of hepatitis, including the potential transmission risks and complications of HBV and HCV. About half acknowledged liver fibrosis and cirrhosis as key determinants of liver-related disease progression. A higher proportion rightly recognized the diagnostic test for HCV (40.8%) than HBV (30.0%) despite more being aware of HBV than HCV. Less than one-third were aware of the risk factors, screening tests, and complications of NAFLD. Despite the majority (92.8%) agreeing that regular screening was important for liver health, only 67.0% attended recent health screening and one-fifth were unlikely to seek medical consultation upon exposure to viral hepatitis risk factors. Reasons for this low urgency included the perception of being healthy, cost-related concerns, and societal discrimination.

    CONCLUSION: Robust education efforts are needed to raise awareness and empower the community with knowledge of liver-related diseases, particularly viral hepatitis and NAFLD in Malaysia.

  11. Barathan M, Gopal K, Mohamed R, Ellegård R, Saeidi A, Vadivelu J, et al.
    Apoptosis, 2015 Apr;20(4):466-80.
    PMID: 25577277 DOI: 10.1007/s10495-014-1084-y
    Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(®) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.
  12. Barathan M, Mohamed R, Vadivelu J, Chang LY, Vignesh R, Krishnan J, et al.
    Cell Immunol, 2017 03;313:1-9.
    PMID: 28104239 DOI: 10.1016/j.cellimm.2016.12.002
    Hepatitis C virus (HCV)-specific CD4+ and CD8+ T cells are key to successful viral clearance in HCV disease. Accumulation of exhausted HCV-specific T cells during chronic infection results in considerable loss of protective functional immune responses. The role of T-cell exhaustion in chronic HCV disease remains poorly understood. Here, we studied the frequency of HCV peptide-stimulated T cells expressing negative immune checkpoints (PD-1, CTLA-4, TRAIL, TIM-3 and BTLA) by flow cytometry, and measured the levels of Th1/Th2/Th17 cytokines secreted by T cells by a commercial Multi-Analyte ELISArray™ following in vitro stimulation of T cells using HCV peptides and phytohemagglutinin (PHA). HCV peptide-stimulated CD4+ and CD8+ T cells of chronic HCV (CHC) patients showed significant increase of CTLA-4. Furthermore, HCV peptide-stimulated CD4+ T cells of CHC patients also displayed relatively higher levels of PD-1 and TRAIL, whereas TIM-3 was up-regulated on HCV peptide-stimulated CD8+ T cells. Whereas the levels of IL-10 and TGF-β1 were significantly increased, the levels of pro-inflammatory cytokines IL-2, TNF-α, IL-17A and IL-6 were markedly decreased in the T cell cultures of CHC patients. Chronic HCV infection results in functional exhaustion of CD4+ and CD8+ T cells likely contributing to viral persistence.
  13. Barathan M, Mohamed R, Saeidi A, Vadivelu J, Chang LY, Gopal K, et al.
    Eur J Clin Invest, 2015 May;45(5):466-74.
    PMID: 25721991 DOI: 10.1111/eci.12429
    Hepatitis C virus (HCV) causes persistent disease in ~85% of infected individuals, where the viral replication appears to be tightly controlled by HCV-specific CD8+ T cells. Accumulation of senescent T cells during infection results in considerable loss of functional HCV-specific immune responses.
  14. Barathan M, Mohamed R, Vadivelu J, Chang LY, Saeidi A, Yong YK, et al.
    Eur J Clin Invest, 2016 Feb;46(2):170-80.
    PMID: 26681320 DOI: 10.1111/eci.12581
    Mucosal-associated invariant T (MAIT) cells play an important role in innate host defence. MAIT cells appear to undergo exhaustion and are functionally weakened in chronic viral infections. However, their role in chronic hepatitis C virus (HCV) infection remains unclear.
  15. Azmi SM, Salih M, Abdelrazeg S, Roslan FF, Mohamed R, Tan JJ, et al.
    Regen Med, 2020 03;15(3):1381-1397.
    PMID: 32253974 DOI: 10.2217/rme-2019-0103
    Aim: As a strategy to improve the outcome of ex vivo cultivated corneal epithelial transplantation, the role of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) is investigated in promoting corneal epithelial growth and functions. Materials & methods: Human telomerase-immortalized corneal epithelial cells were characterized and its functions evaluated by scratch migration assay, cellular senescence, HLA expression and spheres formation with hUC-MSC. Results: Expression of corneal epithelial markers was influenced by the duration and method of co-culture. Indirect co-culture improved cellular migration and delayed senescence when treated after 3 and 5 days. hUC-MSC downregulated expression of HLA Class I and II in IFN-γ-stimulated human telomerase-immortalized corneal epithelial cells. Conclusion: hUC-MSC promote corneal epithelial growth and functions after treatment with hUC-MSC.
  16. Azzeri A, Dahlui M, Mohamed R, McDonald SA, Jaafar H, Shabaruddin FH
    Front Public Health, 2023;11:1114560.
    PMID: 36935675 DOI: 10.3389/fpubh.2023.1114560
    INTRODUCTION: A scaled-up treatment cascade with direct-acting antiviral (DAA) therapy is necessary to achieve global WHO targets for hepatitis C virus (HCV) elimination in Malaysia. Recently, limited access to sofosbuvir/daclatasvir (SOF/DAC) is available through compulsory licensing, with access to sofosbuvir/velpatasvir (SOF/VEL) expected through voluntary licensing due to recent agreements. SOF/VEL has superior clinical outcomes but has higher drug acquisition costs compared to SOF/DAC. A stratified treatment cascade might be the most cost-efficient approach for Malaysia whereby all HCV patients are treated with SOF/DAC except for patients with cirrhosis who are treated with SOF/VEL.

    METHODS: This study aimed to conduct a 5-year budget impact analysis of the proposed stratified treatment cascade for HCV treatment in Malaysia. A disease progression model that was developed based on model-predicted HCV epidemiology data was used for the analysis, where all HCV patients in scenario A were treated with SOF/DAC for all disease stages while in scenario B, SOF/DAC was used only for non-cirrhotic patients and SOF/VEL was used for the cirrhotic patients. Healthcare costs associated with DAA therapy and disease stage monitoring were included to estimate the downstream cost implications.

    RESULTS: The stratified treatment cascade with 109 in Scenario B was found to be cost-saving compared to Scenario A. The cumulative savings for the stratified treatment cascade was USD 1.4 million over 5 years.

    DISCUSSION: A stratified treatment cascade with SOF/VEL was expected to be cost-saving and can result in a budget impact reduction in overall healthcare expenditure in Malaysia.

  17. Chen DS, Hamoudi W, Mustapha B, Layden J, Nersesov A, Reic T, et al.
    J Viral Hepat, 2017 10;24 Suppl 2:44-63.
    PMID: 29105286 DOI: 10.1111/jvh.12759
    The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 17 countries in Africa, Asia, Europe, Latin America and the Middle East, and interventions for achieving the Global Health Sector Strategy on viral hepatitis targets-"WHO Targets" (65% reduction in HCV-related deaths, 90% reduction in new infections and 90% of infections diagnosed by 2030) were considered. Scaling up treatment and diagnosis rates over time would be required to achieve these targets in all but one country, even with the introduction of high SVR therapies. The scenarios developed to achieve the WHO Targets in all countries studied assumed the implementation of national policies to prevent new infections and to diagnose current infections through screening.
  18. Ishola OA, Ting SY, Tabana YM, Ahmed MA, Yunus MA, Mohamed R, et al.
    Jundishapur J Microbiol, 2016 Sep;9(9):e38031.
    PMID: 27800147
    A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility.
  19. Rose S, Aravindakshan S, Mohamed Usman JA, Mohamed R, Menon S, Shafiullah RS, et al.
    J Pharm Bioallied Sci, 2021 Jun;13(Suppl 1):S851-S856.
    PMID: 34447214 DOI: 10.4103/jpbs.JPBS_819_20
    Introduction: Impression making is an integral part of prosthetic dentistry. Development of material science has allowed integrating qualities of hydrophilic polyether and hydrophobic polyvinyl siloxane into a newer hybrid material, vinyl polysiloxane (VPS) ether. This study was aimed to compare the VPS ether with the polyether and polyvinyl siloxane in terms of accuracy and dimensional stability.

    Materials and Methods: Stainless steel dies with the American Dental Association specification 19 were made. Die has three horizontal and two vertical lines which are used for taking the impression. Two cross-points at the junction of the vertical lines with line 2 were marked as x and x' and served as beginning and end points of measurements for dimensional accuracy. Accuracy was evaluated 30 min after making each impression. If at least two of the three horizontal lines were reproduced continuously between cross-points, this impression was considered satisfactory. The specimens are poured with Type IV gypsum product and allowed to set completely for 24 h. Then, dimensional stability was measured in the model by measuring the distance between the two lines and comparing the distance with the measurement of line on metal die, which was used to make the impression.

    Results: The mean value obtained for light- and medium-bodied VPS ether was 0.05370 and 0.05330 and for light and medium-bodied polyvinyl siloxane was 0.06370 and 0.07150, respectively. The mean value for polyether monophase was 0.06430. Two-way ANOVA and post hoc test showed statistical significance.

    Conclusion: The newer VPS ether material showed good surface detail reproduction and dimensional stability when compared with polyvinyl siloxane and polyether.

  20. Malek, M.F., Mamat, M.H., Ismail, A.S., Mohamed, R., Salifairus, M.J., Khusaimi, Z., et al.
    Science Letters, 2016;11(2):36-40.
    MyJurnal
    We had successfully synthesised Mg-doped zinc oxide (MZO) and Cudoped zinc oxide (CZO) nanorod arrays (NRAs) on Al-doped ZnO (ZAO)-coated glass substrates using immersion method and investigated their structural properties. With the incorporation of the Mg dopant, the length and crystallinity of MZO NRAs is higher compared to that of the CZO NRAs. The average optical transmittance of MZO NRAs was slightly lower than that of the CZO NRAs over the visible wavelength region. With the incorporation of the Cu dopant, the morphology of the CZO sample was slightly different from that of the MZO NRAs. The CZO NRAs present granular with small sphere shape. On the other hand, the MZO NRAs exhibit a hexagonal shape structure with a flat-top facet. Rods with a diameter of 58.9-96.7 nm were uniformly grown on the ZAO-coated glass substrate. This paper presents the growth behaviors of the MZO and CZO NRAs.
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