Displaying publications 1 - 20 of 164 in total

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  1. Halim I, Omar AR
    Int J Occup Saf Ergon, 2012;18(1):85-96.
    PMID: 22429532
    Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.
  2. Liew, Pit Sze, Nurulfiza Mat Isa, Omar Abdul Rahman, Aini Ideris, Mohd HAIRBEJO
    MyJurnal
    Infectious bursal disease (IBD), also known as the Gumboro disease, has been a great
    concern for poultry industry worldwide. The first outbreak of IBD due to very virulent (vv) IBD virus
    (IBDV) infection in Malaysia was reported in 1991. The major economic impact of the disease is high
    mortality and poor performance. The virus causes immunosuppression where if the infected chicken
    recovered from the acute disease, they become more susceptible to infections of other pathogens and
    fail to respond to vaccines. Therefore, prevention is important and vaccination has become the
    principal control measure of IBDV infection in chickens. The conventional attenuated live and killed
    vaccines are the most commonly used vaccines. With the advancement of knowledge and technology,
    new generation of genetically-engineered vaccines like viral vector and immune complex vaccines
    have been commercialised. Moreover, hatchery vaccination is becoming a common practise, in
    addition to farm vaccination. Currently, the disease is considerably under controlled with the
    introduction of vaccination. However, occasional field outbreaks are still commonly reported. The
    demand for vaccines that could suit the field situation continues to exist. The endemicity of disease,
    presence of challenge in the farm and maternally derived antibody in chicks are affecting the choice
    vaccine as well as the vaccine development and vaccination strategies. In this review, advances made
    in various vaccines that have been commercialised or under development, and challenges that they
    face, are outlined. Furthermore, how the emergence of vvIBDV affect the progress of vaccine
    development and influence its vaccination strategy are discussed.
  3. Majid NN, Omar AR, Mariatulqabtiah AR
    J Gen Virol, 2020 07;101(7):772-777.
    PMID: 32427095 DOI: 10.1099/jgv.0.001428
    In comparison to the extensive characterization of haemagglutinin antibodies of avian influenza virus (AIV), the role of neuraminidase (NA) as an immunogen is less well understood. This study describes the construction and cellular responses of recombinant fowlpox viruses (rFWPV) strain FP9, co-expressing NA N1 gene of AIV A/Chicken/Malaysia/5858/2004, and chicken IL-12 gene. Our data shows that the N1 and IL-12 proteins were successfully expressed from the recombinants with 48 kD and 70 kD molecular weights, respectively. Upon inoculation into specific-pathogen-free (SPF) chickens at 105 p.f.u. ml-1, levels of CD3+/CD4+ and CD3+/CD8+ populations were higher in the wild-type fowlpox virus FP9 strain, compared to those of rFWPV-N1 and rFWPV-N1-IL-12 at weeks 2 and 5 time points. Furthermore, rFWPV-N1-IL-12 showed a suppressive effect on chicken body weight within 4 weeks after inoculation. We suggest that co-expression of N1 with or without IL-12 offers undesirable quality as a potential AIV vaccine candidate.
  4. Bande F, Arshad SS, Omar AR
    Adv Virol, 2016;2016:9058403.
    PMID: 27597865 DOI: 10.1155/2016/9058403
    Avian leukosis virus (ALV) belongs to the family Retroviridae and causes considerable economic losses to the poultry industry. Following an outbreak associated with high mortality in a broiler flock in northern part of Malaysia, kidney tissues from affected chickens were submitted for virus isolation and identification in chicken embryonated egg and MDCK cells. Evidence of virus growth was indicated by haemorrhage and embryo mortality in egg culture. While viral growth in cell culture was evidenced by the development of cytopathic effects. The isolated virus was purified by sucrose gradient and identified using negative staining transmission electron microscopy. Further confirmation was achieved through next-generation sequencing and nucleotide sequence homology search. Analysis of the viral sequences using the NCBI BLAST tool revealed 99-100% sequence homology with exogenous ALV viral envelope protein. Phylogenetic analysis based on partial envelope sequences showed the Malaysian isolate clustered with Taiwanese and Japanese ALV strains, which were closer to ALV subgroup J, ALV subgroup E, and recombinant A/E isolates. Based on these findings, ALV was concluded to be associated with the present outbreak. It was recommended that further studies should be conducted on the molecular epidemiology and pathogenicity of the identified virus isolate.
  5. Mehrbod P, Harun MS, Shuid AN, Omar AR
    Methods Mol Biol, 2015;1282:241-50.
    PMID: 25720485 DOI: 10.1007/978-1-4939-2438-7_20
    Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV). There are no effective vaccines or treatment available, and the virus virulence determinants and pathogenesis are not fully understood. Here, we describe the sequencing of RNA extracted from Crandell Rees Feline Kidney (CRFK) cells infected with FIPV using the Illumina next-generation sequencing approach. Bioinformatics analysis, based on Felis catus 2X annotated shotgun reference genome, using CLC bio Genome Workbench is used to map both control and infected cells. Kal's Z test statistical analysis is used to analyze the differentially expressed genes from the infected CRFK cells. In addition, RT-qPCR analysis is used for further transcriptional profiling of selected genes in infected CRFK cells and Peripheral Blood Mononuclear Cells (PBMCs) from healthy and FIP-diagnosed cats.
  6. Mehrbod P, Omar AR, Hair-Bejo M, Haghani A, Ideris A
    Biomed Res Int, 2014;2014:872370.
    PMID: 25478576 DOI: 10.1155/2014/872370
    The influenza virus (IV) is known to be a resistant virus with frequent mutations, causing severe respiratory diseases in the upper respiratory system. Public health concerns about clinical efficacy of all conventional drugs are ambiguous; therefore, finding additional therapeutic agents is critical to prevent and control influenza outbreaks. Influenza is associated with the induction of proinflammatory cytokines. Scientists have reported that anti-inflammatory drugs, with pleiotropic effects, reduce the burden of severe influenza diseases. Therefore, statins, which are cardioprotective drugs with anti-inflammatory and immunomodulatory effects, may help patients suffering from influenza virus (IV). This review delineates the potential use of statins as an alternative therapy in treating influenza related illness.
  7. Mehrbod P, Ideris A, Omar AR, Hair-Bejo M
    PMID: 24708698 DOI: 10.1186/1472-6882-14-131
    Influenza virus is still a severe respiratory disease affecting human and other species. As conventional drugs are not recommended for long time because of side effects and drug resistance occurrence, traditional medication has been focused as alternative remedy. HESA-A is a natural compound from herbal-marine origin. Previous studies have reported the therapeutic properties of HESA-A on psoriasis vulgaris and different types of cancers and we also showed its anti-inflammatory effects against influenza A infection.
  8. Choong OK, Mehrbod P, Tejo BA, Omar AR
    Biomed Res Int, 2014;2014:654712.
    PMID: 24707494 DOI: 10.1155/2014/654712
    Feline Infectious Peritonitis (FIP) is a severe fatal immune-augmented disease in cat population. It is caused by FIP virus (FIPV), a virulent mutant strain of Feline Enteric Coronavirus (FECV). Current treatments and prophylactics are not effective. The in vitro antiviral properties of five circular Triple-Helix Forming Oligonucleotide (TFO) RNAs (TFO1 to TFO5), which target the different regions of virulent feline coronavirus (FCoV) strain FIPV WSU 79-1146 genome, were tested in FIPV-infected Crandell-Rees Feline Kidney (CRFK) cells. RT-qPCR results showed that the circular TFO RNAs, except TFO2, inhibit FIPV replication, where the viral genome copy numbers decreased significantly by 5-fold log10 from 10(14) in the virus-inoculated cells to 10(9) in the circular TFO RNAs-transfected cells. Furthermore, the binding of the circular TFO RNA with the targeted viral genome segment was also confirmed using electrophoretic mobility shift assay. The strength of binding kinetics between the TFO RNAs and their target regions was demonstrated by NanoITC assay. In conclusion, the circular TFOs have the potential to be further developed as antiviral agents against FIPV infection.
  9. Imam MU, Ismail M, Omar AR, Ithnin H
    J Diabetes Res, 2013;2013:134694.
    PMID: 23671850 DOI: 10.1155/2013/134694
    Germinated brown rice (GBR) is rich in bioactive compounds, which confer GBR with many functional properties. Evidence of its hypocholesterolemic effects is emerging, but the exact mechanisms of action and bioactive compounds involved have not been fully documented. Using type 2 diabetic rats, we studied the effects of white rice, GBR, and brown rice (BR) on lipid profile and on the regulation of selected genes involved in cholesterol metabolism. Our results showed that the upregulation of apolipoprotein A1 and low-density lipoprotein receptor genes was involved in the hypocholesterolemic effects of GBR. Additionally, in vitro studies using HEPG2 cells showed that acylated steryl glycoside, gamma amino butyric acid, and oryzanol and phenolic extracts of GBR contribute to the nutrigenomic regulation of these genes. Transcriptional and nontranscriptional mechanisms are likely involved in the overall hypocholesterolemic effects of GBR suggesting that it may have an impact on the prevention and/or management of hypercholesterolemia due to a wide variety of metabolic perturbations. However, there is need to conduct long-term clinical trials to determine the clinical relevance of the hypocholesterolemic effects of GBR determined through animal studies.
  10. Halim I, Omar AR, Saman AM, Othman I
    Saf Health Work, 2012 Mar;3(1):31-42.
    PMID: 22953228 DOI: 10.5491/SHAW.2012.3.1.31
    The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods.
  11. Moeini H, Omar AR, Rahim RA, Yusoff K
    Comp Immunol Microbiol Infect Dis, 2011 May;34(3):227-36.
    PMID: 21146874 DOI: 10.1016/j.cimid.2010.11.006
    In the present study, we describe the development of a DNA vaccine against chicken anemia virus. The VP1 and VP2 genes of CAV were amplified and cloned into pBudCE4.1 to construct two DNA vaccines, namely, pBudVP1 and pBudVP2-VP1. In vitro and in vivo studies showed that co-expression of VP1 with VP2 are required to induce significant levels of antibody against CAV. Subsequently, the vaccines were tested in 2-week-old SPF chickens. Chickens immunized with the DNA-plasmid pBudVP2-VP1 showed positive neutralizing antibody titer against CAV. Furthermore, VP1-specific proliferation induction of splenocytes and also high serum levels of Th1 cytokines, IL-2 and IFN-γ were detected in the pBudVP2-VP1-vaccinated chickens. These results suggest that the recombinant DNA plasmid co-expressing VP1 and VP2 can be used as a potential DNA vaccine against CAV.
  12. Moeini H, Omar AR, Rahim RA, Yusoff K
    Virol J, 2011;8:119.
    PMID: 21401953 DOI: 10.1186/1743-422X-8-119
    Studies have shown that the VP22 gene of Marek's Disease Virus type-1 (MDV-1) has the property of movement between cells from the original cell of expression into the neighboring cells. The ability to facilitate the spreading of the linked proteins was used to improve the potency of the constructed DNA vaccines against chicken anemia virus (CAV).
  13. Oveissi S, Omar AR, Yusoff K, Jahanshiri F, Hassan SS
    Comp Immunol Microbiol Infect Dis, 2010 Dec;33(6):491-503.
    PMID: 19781778 DOI: 10.1016/j.cimid.2009.08.004
    The H5 gene of avian influenza virus (AIV) strain A/chicken/Malaysia/5744/2004(H5N1) was cloned into pcDNA3.1 vector, and Esat-6 gene of Mycobacterium tuberculosis was fused into downstream of the H5 gene as a genetic adjuvant for DNA vaccine candidates. The antibody level against AIV was measured using enzyme-linked immunosorbent assay (ELISA) and haemagglutination inhibition (HI) test. Sera obtained from specific-pathogen-free chickens immunized with pcDNA3.1/H5 and pcDNA3.1/H5/Esat-6 demonstrated antibody responses as early as 2 weeks after the first immunization. Furthermore, the overall HI antibody titer in chickens immunized with pcDNA3.1/H5/Esat-6 was higher compared to the chickens immunized with pcDNA3.1/H5 (p<0.05). The results suggested that Esat-6 gene of M. tuberculosis is a potential genetic adjuvant for the development of effective H5 DNA vaccine in chickens.
  14. Hailemariam Z, Omar AR, Hair-Bejo M, Giap TC
    Virol J, 2008;5:128.
    PMID: 18954433 DOI: 10.1186/1743-422X-5-128
    Chicken anemia virus (CAV) is the causative agent of chicken infectious anemia (CIA). Study on the type of CAV isolates present and their genetic diversity, transmission to their progeny and level of protection afforded in the breeder farms is lacking in Malaysia. Hence, the present study was aimed to detect CAV from commercial broiler breeder farms and characterize CAV positive samples based on sequence and phylogenetic analysis of partial VP1 gene.
  15. Omar AR, Kim CL, Bejo MH, Ideris A
    J Vet Sci, 2006 Sep;7(3):241-7.
    PMID: 16871018
    The ability of a heat-inactivated whole virus from a highly virulent infectious bursal disease virus (hvIBDV) and VP2 protein from hvIBDV expressed in E. coli provided protection against a hvIBDV challenge in specificpathogen-free (SPF) chickens. Six out of seven chickens that were injected three times with crude VP2 protein developed significant antibody titer against IBDV. However, only four out of the seven chickens survived the hvIBDV challenge. Despite showing low antibody titer profiles, all chickens immunized with the heat-inactivated whole virus also survived the challenged with hvIBDV. However, all of these chickens had bursal atrophy and mild to moderate depletion of lymphocytes. Thus, antibodies raised against IBDV VP2 protein expressed in E. coli and denatured IBDV proteins induced some degree of protection against mortality but not against bursal damage following challenge with hvIBDV.
  16. Imam MU, Ismail M, Ithnin H, Tubesha Z, Omar AR
    Nutrients, 2013 Feb;5(2):468-77.
    PMID: 23389305 DOI: 10.3390/nu5020468
    Dysregulated metabolism is implicated in obesity and other disease conditions like type 2 diabetes mellitus and cardiovascular diseases, which are linked to abnormalities of peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ has been the focus of much research aimed at managing these diseases. Also, germinated brown rice (GBR) is known to possess antidiabetic, antiobesity and hypocholesterolemic effects. We hypothesized that GBR bioactive compounds may mediate some of the improvements in metabolic indices through PPARγ modulation. Cultured HEP-G2 cells were treated with 50 ppm and 100 ppm of extracts from GBR (GABA, ASG and oryzanol) after determination of cell viabilities using MTT assays. Results showed that all extracts upregulated the expression of the PPARγ. However, combination of all three extracts showed downregulation of the gene, suggesting that, in combination, the effects of these bioactives differ from their individual effects likely mediated through competitive inhibition of the gene. Upregulation of the gene may have therapeutic potential in diabetes mellitus and cardiovascular diseases, while its downregulation likely contributes to GBR's antiobesity effects. These potentials are worth studying further.
  17. Murulitharan K, Yusoff K, Omar AR, Molouki A
    Virus Genes, 2013 Jun;46(3):431-40.
    PMID: 23306943 DOI: 10.1007/s11262-012-0874-y
    Newcastle disease virus (NDV) strain AF2240 is a viscerotropic velogenic strain that is used as a vaccine challenge virus in Malaysia. The identification of the full length genome will be a crucial platform for further studies of this isolate. In this study, we fully sequenced the genome of a derivative of this strain named AF2240-I. The 15,192 nt long genome contains a 55-nt leader sequence at the 3' whereas the trailer region consists of 114 nt at the 5'. The intergenic sequences between the NP-P, P-M, M-F, F-HN, and HN-L genes comprise 1, 1, 1, 31, and 47 nt, respectively. The acknowledged cleavage site of fusion protein showed amino acid sequence of 112-R-R-Q-K-R-F-117, which corresponds to those of virulent NDV strains. Phylogenetic analysis of the whole virus genome shows that the strain AF2240-I belongs to genotype VIII and is more closely related to velogenic strains QH1, QH4, Fontana, Largo, and Italienas compared to other strains of NDV. Differences are noticed in the hemagglutinin-neuraminidase (HN) and matrix (M) gene between AF2240 and its derivative AF2240-I. This is the first report of a complete genome sequence of an NDV strain isolated in Malaysia.
  18. Jazayeri SD, Ideris A, Shameli K, Moeini H, Omar AR
    Int J Nanomedicine, 2013;8:781-90.
    PMID: 23459681 DOI: 10.2147/IJN.S39074
    In order to develop a systemically administered safe and effective nonviral gene delivery system against avian influenza virus (AIV) that induced cytokine expression, the hemagglutinin (H5) gene of AIV, A/Ck/Malaysia/5858/04 (H5N1) and green fluorescent protein were cloned into a coexpression vector pIRES (pIREGFP-H5) and formulated using green synthesis of silver nanoparticles (AgNPs) with poly(ethylene glycol) and transfected into primary duodenal cells taken from 18-day-old specific-pathogen-free chick embryos. The AgNPs were prepared using moderated temperature and characterized for particle size, surface charge, ultraviolet-visible spectra, DNA loading, and stability. AgNPs and AgNP-pIREGFP-H5 were prepared in the size range of 13.9 nm and 25 nm with a positive charge of +78 ± 0.6 mV and +40 ± 6.2 mV, respectively. AgNPs with a positive surface charge could encapsulate pIREGFP-H5 efficiently. The ultraviolet-visible spectra for AgNP-pIREGFP-H5 treated with DNase I showed that the AgNPs were able to encapsulate pIREGFP-H5 efficiently. Polymerase chain reaction showed that AgNP-pIREGFP-H5 entered into primary duodenal cells rapidly, as early as one hour after transfection. Green fluorescent protein expression was observed after 36 hours, peaked at 48 hours, and remained stable for up to 60 hours. In addition, green fluorescent protein expression generally increased with increasing DNA concentration and time. Cells were transfected using Lipocurax in vitro transfection reagent as a positive control. A multiplex quantitative mRNA gene expression assay in the transfected primary duodenal cells via the transfection reagent and AgNPs with pIREGFP-H5 revealed expression of interleukin (IL)-18, IL-15, and IL-12β.
  19. Ghrici M, El Zowalaty M, Omar AR, Ideris A
    Oncol Rep, 2013 Sep;30(3):1035-44.
    PMID: 23807159 DOI: 10.3892/or.2013.2573
    Newcastle disease virus (NDV) exerts its naturally occurring oncolysis possibly through the induction of apoptosis. We hypothesized that the binding of the virus to the cell via the hemagglutinin-neuraminidase (HN) glycoprotein may be sufficient to not only induce apoptosis but to induce a higher apoptosis level than the parental NDV AF2240 virus. NDV AF2240 induction of apoptosis in MCF-7 human breast cancer cells was analyzed and quantified. In addition, the complete HN gene of NDV strain AF2240 was amplified, sequenced and cloned into the pDisplay eukaryotic expression vector. HN gene expression was first detected at the cell surface membrane of the transfected MCF-7 cells. HN induction of apoptosis in transfected MCF-7 cells was analyzed and quantified. The expression of the HN gene alone was able to induce apoptosis in MCF-7 cells but it was a less potent apoptosis inducer compared to the parental NDV AF2240 strain. In conclusion, the NDV AF2240 strain is a more suitable antitumor candidate agent than its recombinant HN gene unless the latter is further improved by additional modifications.
  20. Ghrici M, El Zowalaty M, Omar AR, Ideris A
    Int J Mol Med, 2013 Mar;31(3):525-32.
    PMID: 23337979 DOI: 10.3892/ijmm.2013.1244
    Newcastle disease virus (NDV) AF2240 Malaysian strain is a very virulent avian virus. NDV strain AF2240 was previously demonstrated to induce apoptosis in human breast carcinoma MCF-7 cells. However, at which stage of the NDV life cycle apoptosis is induced and whether NDV replication and protein synthesis are involved in apoptosis induction have yet to be determined. In the present study, we investigated the time course of NDV strain AF2240 nucleoprotein (NP) gene expression and the early apoptotic signs in the form of activation of caspase-8 and mitochondrial transition pore opening. In addition, the induction of apoptosis by both ultraviolet-inactivated and cycloheximide-treated NDV-infected MCF-7 cells were examined. Our findings showed that NDV strain AF2240 induced apoptosis at 1 h post-infection (pi) through activation of mitochondrial transition pore opening and at 2 h through activation of caspase-8, while the NP gene was expressed at 6 h pi. The induced apoptosis was independent of both virus replication and protein synthesis. In conclusion, NDV strain AF2240 induces apoptosis at an early stage of its life cycle, possibly during virus binding or fusion with the cell membrane. The mitochondrial-related pathway may be the central activator in NDV strain AF2240-induced apoptosis.
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