Displaying publications 1 - 20 of 313 in total

  1. Hashimoto T, Ozaki A, Bhandari D, Sawano T, Murayama A, Shrestha S, et al.
    Travel Med Infect Dis, 2021 07 21;43:102145.
    PMID: 34298174 DOI: 10.1016/j.tmaid.2021.102145
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  2. Rahman MM, Wong KK, Alfizah H, Hussin S, Isahak I
    Pak J Med Sci, 2015 Jul-Aug;31(4):791-4.
    PMID: 26430404 DOI: 10.12669/pjms.314.7003
    To determine the efficacy of cell culture, immunoflourescence Assay (IFA) and real time polymerase chain reaction (rRT-PCR) in relation to diagnosis of influenza and Respiratory Syncytial Virus (RSV).
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  3. Ahmed SA, Sandai DA, Musa S, Hoe CH, Riadzi M, Lau KL, et al.
    Malays J Med Sci, 2012 Jul;19(3):9-16.
    PMID: 23610544 MyJurnal
    Traditionally, the most common diagnostic approach used for diagnosing leptospirosis was the demonstration of immune-seroconversion in acute and convalescent patient serum samples. Recently, a variety of molecular techniques, including conventional and real-time polymerase chain reaction (PCR), have been developed for the specific detection of pathogenic bacteria from the genus Leptospira. PCR is a sensitive, specific, and rapid technique that has been successfully used to detect several microorganisms; including those of clinical significance.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  4. Chan PL, Rose RJ, Abdul Murad AM, Zainal Z, Low ET, Ooi LC, et al.
    PLoS One, 2014;9(6):e99774.
    PMID: 24927412 DOI: 10.1371/journal.pone.0099774
    The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR). With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction/methods*
  5. Mohd Ali MR, Lih Huey L, Foo PC, Goay YX, Ismail AS, Mustaffa KMF, et al.
    Biomed Res Int, 2019;2019:9451791.
    PMID: 31355287 DOI: 10.1155/2019/9451791
    Melioidosis and leptospirosis, caused by two different bacteria, Burkholderia pseudomallei and Leptospira spp., are potentially fatal infections that share a very similar spectrum of clinical features and cause significant mortality and morbidity in humans and livestock. Early detection is important for better clinical consequences. To our knowledge, there is no diagnostic tool available to simultaneously detect and differentiate melioidosis and leptospirosis in humans and animals. In this study, we described a duplex TaqMan probe-based qPCR for the detection of B. pseudomallei and Leptospira spp. DNA. The performance of the assay was evaluated on 20 B. pseudomallei isolates, 23 Leptospira strains, and 39 other microorganisms, as well as two sets of serially diluted reference strains. The duplex qPCR assay was able to detect 0.02 pg (~ 4 copies) Leptospira spp. DNA and 0.2 pg (~ 25.6 copies) B. pseudomallei DNA. No undesired amplification was observed in other microorganisms. In conclusion, the duplex qPCR assay was sensitive and specific for the detection of B. pseudomallei & Leptospira spp. DNA and is suitable for further analytical and clinical evaluation.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction*
  6. Khang TF, Lau CY
    PeerJ, 2015;3:e1360.
    PMID: 26539333 DOI: 10.7717/peerj.1360
    Background. A common research goal in transcriptome projects is to find genes that are differentially expressed in different phenotype classes. Biologists might wish to validate such gene candidates experimentally, or use them for downstream systems biology analysis. Producing a coherent differential gene expression analysis from RNA-seq count data requires an understanding of how numerous sources of variation such as the replicate size, the hypothesized biological effect size, and the specific method for making differential expression calls interact. We believe an explicit demonstration of such interactions in real RNA-seq data sets is of practical interest to biologists. Results. Using two large public RNA-seq data sets-one representing strong, and another mild, biological effect size-we simulated different replicate size scenarios, and tested the performance of several commonly-used methods for calling differentially expressed genes in each of them. We found that, when biological effect size was mild, RNA-seq experiments should focus on experimental validation of differentially expressed gene candidates. Importantly, at least triplicates must be used, and the differentially expressed genes should be called using methods with high positive predictive value (PPV), such as NOISeq or GFOLD. In contrast, when biological effect size was strong, differentially expressed genes mined from unreplicated experiments using NOISeq, ASC and GFOLD had between 30 to 50% mean PPV, an increase of more than 30-fold compared to the cases of mild biological effect size. Among methods with good PPV performance, having triplicates or more substantially improved mean PPV to over 90% for GFOLD, 60% for DESeq2, 50% for NOISeq, and 30% for edgeR. At a replicate size of six, we found DESeq2 and edgeR to be reasonable methods for calling differentially expressed genes at systems level analysis, as their PPV and sensitivity trade-off were superior to the other methods'. Conclusion. When biological effect size is weak, systems level investigation is not possible using RNAseq data, and no meaningful result can be obtained in unreplicated experiments. Nonetheless, NOISeq or GFOLD may yield limited numbers of gene candidates with good validation potential, when triplicates or more are available. When biological effect size is strong, NOISeq and GFOLD are effective tools for detecting differentially expressed genes in unreplicated RNA-seq experiments for qPCR validation. When triplicates or more are available, GFOLD is a sharp tool for identifying high confidence differentially expressed genes for targeted qPCR validation; for downstream systems level analysis, combined results from DESeq2 and edgeR are useful.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  7. Mohamad NA, Mustafa S, El Sheikha AF, Khairil Mokhtar NF, Ismail A, Ali ME
    J Sci Food Agric, 2016 May;96(7):2344-51.
    PMID: 26441285 DOI: 10.1002/jsfa.7482
    Poor quality and quantity of DNA extracted from gelatin and gelatin capsules often causes failure in the determination of animal species using PCR. Gelatin, which is mainly derived from porcine and bovine, has been a matter of concern among customers in order to fulfill religious obligation and safety precaution against several transmissible infectious diseases associated with bovine species. Thus, optimised DNA extraction from gelatin is very important for successful real-time PCR detection of gelatin species. In this work, the DNA extraction method was optimised in terms of lysis incubation period and inclusion of pre-treatment pH modification of samples.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  8. Chin, Yuet Meng, Arison Mohamad, Zubaidah Zakaria
    For many years counting cells and identifying them under the microscope has been the conventional method to determine the number of abnormal and normal cells in cancers. During the last decade, studies have shown that the detection and quantification of residual tumor cells is important in predicting the clinical outcome of several types of hematological malignancies. Detection of
    minimal residual disease (MRD) is now becoming routinely implemented in treatment protocols and is increasingly used for guiding therapy and for evaluation of new treatment modalities (Raanani & Hashomer, 2004). A wide variety of techniques have been developed to detect residual malignant cells beyond the sensitivity of conventional approaches by cell morphology. One of these technology is by real time quantitative (RQ) polymerase chain reaction (PCR) using the Taqman and LightCycler systems.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  9. Mohd Ali MR, Mohd Safee AW, Ismail NH, Abu Sapian R, Mat Hussin H, Ismail N, et al.
    Mol Cell Probes, 2018 04;38:1-6.
    PMID: 29524642 DOI: 10.1016/j.mcp.2018.03.001
    BACKGROUND: Early diagnosis of leptospirosis is important for ensuring better clinical management and achieving better outcomes. Currently, serological assays suffer from inconsistent performance and are less useful for early diagnosis of leptospirosis. As an alternative, qPCR is more sensitive, specific and able to detect the presence of leptospiral DNA during the acute phase of the infection. Meanwhile, most molecular assays do not detect the non-pathogenic group of Leptospira, even though these groups may also infect humans, although less frequently and less severely.

    METHODS: A set of primers and probe targeting rrs genes of 22 Leptospira spp. were designed and evaluated on 31 Leptospira isolates, 41 other organisms and 65 clinical samples from suspected patients.

    RESULTS: The developed assay was able to detect as low as 20 fg Leptospira DNA per reaction (equivalent to approximately 4 copies) and showed high specificity against the tested leptospiral strains. No cross amplification was observed with the other organisms. During the evaluation of the confirmed clinical specimens, the developed assay was able to correctly identify all positive samples (n = 10/10). One amplification was observed in a negative sample (n = 1/55). The sequencing of the PCR product of the discordant sample revealed that the sequences were similar to those of L. interrogans and L. kirschneri.

    CONCLUSION: The findings suggest that the developed Taqman qPCR assay is sensitive, specific and has potential to be applied in a larger subsequent study.

    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  10. Awang H, Hamzah FH, Ahmad MH, Mahmood MF, Wahab A, Embong K, et al.
    Infect Dis (Lond), 2021 05;53(5):390-392.
    PMID: 33512265 DOI: 10.1080/23744235.2021.1876913
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  11. George R, Donald PM, Nagraj SK, Idiculla JJ, Hj Ismail R
    Malays J Med Sci, 2013 Jan;20(1):76-80.
    PMID: 23785258 MyJurnal
    Sex determination is the most important step in personal identification in forensic investigations. DNA-based sex determination analysis is comparatively more reliable than the other conventional methods of sex determination analysis. Advanced technology like real-time polymerase chain reaction (PCR) offers accurate and reproducible results and is at the level of legal acceptance. But still there are situations like chimerism where an individual possess both male and female specific factors together in their body. Sex determination analysis in such cases can give erroneous results. This paper discusses the phenomenon of chimerism and its impact on sex determination analysis in forensic investigations.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  12. Ng DC, Chin L, Choo PPL, Paramasivam U
    BMJ Case Rep, 2021 May 31;14(5).
    PMID: 34059550 DOI: 10.1136/bcr-2021-243783
    We report a case of COVID-19 in a 29-week preterm infant. This child is the youngest reported case of SARS-CoV-2 infection in Malaysia, and to the best of our knowledge, one of the youngest documented cases of established vertical transmission of SARS-CoV-2 reported in literature. Our report highlights the clinical course, timelines of viral shedding by real-time reverse transcription-PCR and antibody seroconversion in a premature infant infected with SARS-CoV-2. In addition, we discuss the challenges faced in managing a preterm infant infected with SARS-CoV-2 and the knowledge gaps that need to be explored.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  13. Hossain MAM, Ali ME, Sultana S, Asing, Bonny SQ, Kader MA, et al.
    J Agric Food Chem, 2017 May 17;65(19):3975-3985.
    PMID: 28481513 DOI: 10.1021/acs.jafc.7b00730
    Cattle, buffalo, and porcine materials are widely adulterated, and their quantification might safeguard health, religious, economic, and social sanctity. Recently, conventional polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) assays have been documented but they are just suitable for identification, cannot quantify adulterations. We described here a quantitative tetraplex real-time PCR assay with TaqMan Probes to quantify contributions from cattle, buffalo, and porcine materials simultaneously. Amplicon-sizes were very short (106-, 90-, and 146-bp for cattle, buffalo, and porcine) because longer targets could be broken down, bringing serious ambiguity in molecular diagnostics. False negative detection was eliminated through an endogenous control (141-bp site of eukaryotic 18S rRNA). Analysis of 27 frankfurters and 27 meatballs reflected 84-115% target recovery at 0.1-10% adulterations. Finally, a test of 36 commercial products revealed 71% beef frankfurters, 100% meatballs, and 85% burgers contained buffalo adulteration, but no porcine was found in beef products.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction/instrumentation; Real-Time Polymerase Chain Reaction/methods*
  14. Mohamad NA, Mustafa S, Khairil Mokhtar NF, El Sheikha AF
    J Sci Food Agric, 2018 Sep;98(12):4570-4577.
    PMID: 29505123 DOI: 10.1002/jsfa.8985
    BACKGROUND: The pharmaceutical industry has boosted gelatin consumption worldwide. This is supported by the availability of cost-effective gelatin production from porcine by-products. However, cross-contamination of gelatin materials, where porcine gelatin was unintentionally included in the other animal sources of gelatin, has caused significant concerns about halal authenticity. The real-time polymerase chain reaction (PCR) has enabled a highly specific and sensitive animal species detection method in various food products. Hence, such a technique was employed in the present study to detect and quantify porcine DNA in gelatin using a molecular beacon probe, with differences in performance between mitochondrial (cytochrome b gene) and chromosomal DNA-(MPRE42 repetitive element) based porcine-specific PCR assays being compared.

    RESULTS: A higher sensitivity was observed in chromosomal DNA (MPRE-PCR assay), where this assay allows the detection of gelatin DNA at amounts as as low as 1 pg, whereas mitochondrial DNA (CBH-PCR assay) can only detect at levels down to 10 pg of gelatin DNA. When an analysis with commercial gelatin and gelatin capsule samples was conducted, the same result was observed, with a significantly more sensitive detection being provided by the repetitive element of chromosomal DNA.

    CONCLUSION: The present study has established highly sensitive DNA-based porcine detection systems derived from chromosomal DNA that are feasible for highly processed products such as gelatin and gelatin capsules containing a minute amount of DNA. This sensitive detection method can also be implemented to assist the halal authentication process of various food products available on the market. © 2018 Society of Chemical Industry.

    Matched MeSH terms: Real-Time Polymerase Chain Reaction/instrumentation; Real-Time Polymerase Chain Reaction/methods*
  15. Makhtar ST, Tan SW, Nasruddin NA, Abdul Aziz NA, Omar AR, Mustaffa-Kamal F
    BMC Vet Res, 2021 Mar 23;17(1):128.
    PMID: 33757494 DOI: 10.1186/s12917-021-02837-6
    BACKGROUND: Morbilliviruses are categorized under the family of Paramyxoviridae and have been associated with severe diseases, such as Peste des petits ruminants, canine distemper and measles with evidence of high morbidity and/or could cause major economic loss in production of livestock animals, such as goats and sheep. Feline morbillivirus (FeMV) is one of the members of Morbilliviruses that has been speculated to cause chronic kidney disease in cats even though a definite relationship is still unclear. To date, FeMV has been detected in several continents, such as Asia (Japan, China, Thailand, Malaysia), Europe (Italy, German, Turkey), Africa (South Africa), and South and North America (Brazil, Unites States). This study aims to develop a TaqMan real-time RT-PCR (qRT-PCR) assay targeting the N gene of FeMV in clinical samples to detect early phase of FeMV infection.

    RESULTS: A specific assay was developed, since no amplification was observed in viral strains from the same family of Paramyxoviridae, such as canine distemper virus (CDV), Newcastle disease virus (NDV), and measles virus (MeV), and other feline viruses, such as feline coronavirus (FCoV) and feline leukemia virus (FeLV). The lower detection limit of the assay was 1.74 × 104 copies/μL with Cq value of 34.32 ± 0.5 based on the cRNA copy number. The coefficient of variations (CV) values calculated for both intra- and inter-assay were low, ranging from 0.34-0.53% and 1.38-2.03%, respectively. In addition, the clinical sample evaluation using this assay showed a higher detection rate, with 25 (35.2%) clinical samples being FeMV-positive compared to 11 (15.5%) using conventional RT-PCR, proving a more sensitive assay compared to the conventional RT-PCR.

    CONCLUSIONS: The TaqMan-based real-time RT-PCR assay targeting the N gene described in this study is more sensitive, specific, rapid, and reproducible compared to the conventional RT-PCR assay targeting the N gene, which could be used to detect early infection in cats.

    Matched MeSH terms: Real-Time Polymerase Chain Reaction/methods; Real-Time Polymerase Chain Reaction/veterinary*
  16. Teoh BT, Sam SS, Tan KK, Johari J, Abd-Jamil J, Hooi PS, et al.
    Sci Rep, 2016 06 09;6:27663.
    PMID: 27278716 DOI: 10.1038/srep27663
    Timely and accurate dengue diagnosis is important for differential diagnosis and immediate implementation of appropriate disease control measures. In this study, we compared the usefulness and applicability of NS1 RDT (NS1 Ag Strip) and qRT-PCR tests in complementing the IgM ELISA for dengue diagnosis on single serum specimen (n = 375). The NS1 Ag Strip and qRT-PCR showed a fair concordance (κ = 0.207, p = 0.001). While the NS1 Ag Strip showed higher positivity than qRT-PCR for acute (97.8% vs. 84.8%) and post-acute samples (94.8% vs. 71.8%) of primary infection, qRT-PCR showed higher positivity for acute (58.1% vs. 48.4%) and post-acute (50.0% vs.41.4%) samples in secondary infection. IgM ELISA showed higher positivity in samples from secondary dengue (74.2-94.8%) than in those from primary dengue (21.7-64.1%). More primary dengue samples showed positive with combined NS1 Ag Strip/IgM ELISA (99.0% vs. 92.8%) whereas more secondary samples showed positive with combined qRT-PCR/IgM ELISA (99.4% vs. 96.2%). Combined NS1 Ag Strip/IgM ELISA is a suitable combination tests for timely and accurate dengue diagnosis on single serum specimen. If complemented with qRT-PCR, combined NS1 Ag Strip/IgM ELISA would improve detection of secondary dengue samples.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction/methods*; Real-Time Polymerase Chain Reaction/standards
  17. Selvarajah GT, Bonestroo FAS, Timmermans Sprang EPM, Kirpensteijn J, Mol JA
    BMC Vet Res, 2017 Nov 25;13(1):354.
    PMID: 29178874 DOI: 10.1186/s12917-017-1281-3
    BACKGROUND: Quantitative PCR (qPCR) is a common method for quantifying mRNA expression. Given the heterogeneity present in tumor tissues, it is crucial to normalize target mRNA expression data using appropriate reference genes that are stably expressed under a variety of pathological and experimental conditions. No studies have validated specific reference genes in canine osteosarcoma (OS). Previous gene expression studies involving canine OS have used one or two reference genes to normalize gene expression. This study aimed to validate a panel of reference genes commonly used for normalization of canine OS gene expression data using the geNorm algorithm. qPCR analysis of nine canine reference genes was performed on 40 snap-frozen primary OS tumors and seven cell lines.

    RESULTS: Tumors with a variety of clinical and pathological characteristics were selected. Gene expression stability and the optimal number of reference genes for gene expression normalization were calculated. RPS5 and HNRNPH were highly stable among OS cell lines, while RPS5 and RPS19 were the best combination for primary tumors. Pairwise variation analysis recommended four and two reference genes for optimal normalization of the expression data of canine OS tumors and cell lines, respectively.

    CONCLUSIONS: Appropriate combinations of reference genes are recommended to normalize mRNA levels in canine OS tumors and cell lines to facilitate standardized and reliable quantification of target gene expression, which is essential for investigating key genes involved in canine OS metastasis and for comparative biomarker discovery.

    Matched MeSH terms: Real-Time Polymerase Chain Reaction/methods; Real-Time Polymerase Chain Reaction/veterinary
  18. Tan LL, Ahmed SA, Ng SK, Citartan M, Raabe CA, Rozhdestvensky TS, et al.
    Food Chem, 2020 Mar 30;309:125654.
    PMID: 31678669 DOI: 10.1016/j.foodchem.2019.125654
    A specialized DNA extraction method and a SYBR Green quantitative polymerase chain reaction (SyG-qPCR) assay were combined to generate a ready-to-use kit for rapid detection of porcine admixtures in processed meat products. Our qPCR assay utilized repetitive LINE-1 elements specific to the genome of Sus scrofa domesticus (pig) as a target and incorporated internal controls. We improved the genomic DNA extraction method, and reduced extraction times to the minimum. The method was validated for specificity, sensitivity (0.001% w/w) and robustness, and values were compared with those of a commercially available kit. We also tested our method using 121 processed food products and consistently detected amplification only in samples containing pork. Due to its efficiency and cost-effectiveness, our method represents a valuable new method for detecting food adulteration with pork that is superior to existing quality control approaches.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction/instrumentation; Real-Time Polymerase Chain Reaction/methods*
  19. MyJurnal
    Malaysia, Biosafety Bill 2006 was approved by Parliament in July 2007, and labeling legislation will be implemented soon. In this study, duplex polymerase chain reaction (PCR) was carried out to detect
    endogenous soybean lectin gene and exogenous cp4-epsps (5’-enolpyruvylshikimate-3-phospate synthase) gene simultaneously. Additionally, real-time PCR utilizing SYBR Green fluorescence dye were established for the quantitative analysis of Roundup Ready soybean (RRS), which is based on the two established calibration curve from cloned fragment of cp4-epsps gene and lectin gene respectively. Approximately, 39.5% (45/114) of the samples examined in this study contain RRS, animal feeds (31), processed food (13) and raw soybean (1). Additionally, 75.6% (34/45) of the positive samples were found contained RRS above 0.9%. The sensitive GMO quantitative approach described in this study enable the analysis of various samples and this will facilitate the labeling process.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction
  20. Anand S, Rajan M, Venkateshbabu N, Kandaswamy D, Shravya Y, Rajeswari K
    Open Dent J, 2016;10:160-5.
    PMID: 27386000 DOI: 10.2174/1874210601610010160
    AIM: To compare the antibacterial efficacy of Azadirachta indica (Neem), Commiphora myrrha (Myrrh), Glycyrrhiza glabra (Liquorice) with 2% Chlorhexidine (CHX) against E. faecalis by using Real Time PCR.

    MATERIALS AND METHODS: A total of fifty teeth specimens (n=50) were inoculated with E. faecalis for 21 days. Specimens were divided into five groups (Group 1: Myrrh, Group 2: Neem, Group 3: Liquorice, Group 4: 2% CHX and Group 5: Saline (negative control)). The intracanal medicaments were packed inside the tooth. After 5 days, the remaining microbial load was determined by using real time PCR.

    RESULTS: Threshold cycle (Ct) values of Myrrh extract, Neem extract, Liquorice Extract, 2% CHX and saline were found to be 30.94, 23.85, 21.38, 30.93 and 17.8 respectively.

    CONCLUSION: Myrrh extract showed inhibition of E.faecalis equal to that of 2% CHX followed by Neem, Liquorice and Saline.

    Matched MeSH terms: Real-Time Polymerase Chain Reaction
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