Displaying publications 41 - 60 of 330 in total

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  1. Abolnik C, Mubamba C, Wandrag DBR, Horner R, Gummow B, Dautu G, et al.
    Transbound Emerg Dis, 2018 Apr;65(2):e393-e403.
    PMID: 29178267 DOI: 10.1111/tbed.12771
    It is widely accepted that Newcastle disease is endemic in most African countries, but little attention has been afforded to establishing the sources and frequency of the introductions of exotic strains. Newcastle disease outbreaks have a high cost in Africa, particularly on rural livelihoods. Genotype VIIh emerged in South-East Asia and has since caused serious outbreaks in poultry in Malaysia, Indonesia, southern China, Vietnam and Cambodia. Genotype VIIh reached the African continent in 2011, with the first outbreaks reported in Mozambique. Here, we used a combination of phylogenetic evidence, molecular dating and epidemiological reports to trace the origins and spread of subgenotype VIIh Newcastle disease in southern Africa. We determined that the infection spread northwards through Mozambique, and then into the poultry of the north-eastern provinces of Zimbabwe. From Mozambique, it also reached neighbouring Malawi and Zambia. In Zimbabwe, the disease spread southward towards South Africa and Botswana, causing outbreaks in backyard chickens in early-to-mid 2013. In August 2013, the disease entered South Africa's large commercial industry, and the entire country was infected within a year, likely through fomites and the movements of cull chickens. Illegal poultry trading or infected waste from ships and not wild migratory birds was the likely source of the introduction to Mozambique in 2011.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/veterinary
  2. Kahraman H, Altay Koçak A, Albakkour K, Muftah H, Dalgıç B, Çağlar K, et al.
    Mikrobiyol Bul, 2021 Oct;55(4):553-567.
    PMID: 34666655 DOI: 10.5578/mb.20219707
    Rotaviruses are the most common cause of viral gastroenteritis with the highest mortality and morbidity rates in children aged 0-5 years. The aim of this study was to determine the frequency of rotavirus infection in patients whose stool samples were sent to microbiology laboratory to investigate the etiology of diarrhea, to investigate the rotavirus genotypes that are common in our region and G10, G12 genotypes that have recently become common in the world. Fecal samples of 476 patients aged between 0-92 years who applied between November 2016 and February 2018 were studied via immunochromatographic rapid test and enzyme-linked immunosorbent assay (ELISA) methods. ELISA positive samples were studied by nested reverse transcriptase chain reaction (RT-PCR) and genotyped by agarose gel electrophoresis. Rotavirus was found positive in 18.3% and 17% of stool samples by immunochromatographic test and ELISA, respectively. All ELISA positive samples were also detected as positive by RT-PCR. 18.5% of female patients and 15.7% of male patients were found to be positive and rotavirus positivity was not statistically significant between genders. The frequency of rotavirus in different age groups was 23.5% (6-12 years), 17.3% (13-24 months) and 16% (25-36 months). It was determined that rotavirus cases were most common in the spring. G1, G2, G3, G4, G9, G10, and G12 were detected in 37%, 7.4%, 16.1%, 6.2%, 9.9%, 2.5%, 26% of the samples, respectively. G12 was the most common genotype after G1. The most common G and P genotype combination was G1P[8] (17.2%). This was followed by G12P[8] (11.11%) and G3P[8] (11.11%). P[8] (53%) was found to be the dominant P genotype. In this study, it was observed that rotavirus, which is the cause of childhood diarrhea, can also be encountered in advanced ages and even new genotypes that infect humans worldwide may also be the causative agents. Therefore, we concluded that it is important to investigate new genotypes such as G10 and G12 in molecular epidemiological studies.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  3. Kannan M, Mohamad Saad M, Zainal Z, Kassim H, Ismail I, Talip N, et al.
    Iran J Biotechnol, 2020 Oct;18(4):e2566.
    PMID: 34056024 DOI: 10.30498/IJB.2020.2566
    Background: Rice tungro disease (RTD) is a viral disease mainly affecting rice in Asia. RTD caused by Rice tungro bacilliform virus and Rice tungro spherical virus. To date, there are only 5 RTSV isolates have been reported.

    Objectives: In this study, we aimed to report the complete nucleotide sequence of Malaysian isolate of Rice tungro spherical virus Seberang Perai (RTSV-SP) for the first time. RTSV-SP was characterized and its evolutionary relationship with previously reported Indian and Philippines isolates were elucidated.

    Materials and Methods: RTSV-SP isolate was isolated from a recent outbreak in a paddy field in Seberang Perai zone of Malaysia. Its complete genome was amplified by RT-PCR, cloned and sequenced.

    Results: Sequence analysis indicated that the genome of RTSV-SP consisted of 12,173 nucleotides (nt). Comparative analysis of 6 complete genome sequences using Clustal Omega showed that Seberang Perai isolate shared the highest nucleotide identity (96.04%) with Philippine-A isolate, except that the sORF-2 of RTSV-SP is shorter than RTSV Philippine-A by 27 amino acid residues. RTSV-SP found to cluster in Southeast Asia (SEA) group based on the whole genome sequence phylogenetic analysis using MEGA X software.

    Conclusions: Phylogenetic classification of RTSV isolates based on the complete nucleotide sequences showed more distinctive clustering pattern with the addition of RTSV-SP whole genome to the available isolates. Present study described the isolation and molecular characterization of RTSV-SP.

    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  4. L'Azou M, Moureau A, Sarti E, Nealon J, Zambrano B, Wartel TA, et al.
    N Engl J Med, 2016 Mar 24;374(12):1155-66.
    PMID: 27007959 DOI: 10.1056/NEJMoa1503877
    BACKGROUND: The control groups in two phase 3 trials of dengue vaccine efficacy included two large regional cohorts that were followed up for dengue infection. These cohorts provided a sample for epidemiologic analyses of symptomatic dengue in children across 10 countries in Southeast Asia and Latin America in which dengue is endemic.
    METHODS: We monitored acute febrile illness and virologically confirmed dengue (VCD) in 3424 healthy children, 2 to 16 years of age, in Asia (Indonesia, Malaysia, the Philippines, Thailand, and Vietnam) from June 2011 through December 2013 and in 6939 children, 9 to 18 years of age, in Latin America (Brazil, Colombia, Honduras, Mexico, and Puerto Rico) from June 2011 through April 2014. Acute febrile episodes were determined to be VCD by means of a nonstructural protein 1 antigen immunoassay and reverse-transcriptase-polymerase-chain-reaction assays. Dengue hemorrhagic fever was defined according to 1997 World Health Organization criteria.
    RESULTS: Approximately 10% of the febrile episodes in each cohort were confirmed to be VCD, with 319 VCD episodes (4.6 episodes per 100 person-years) occurring in the Asian cohort and 389 VCD episodes (2.9 episodes per 100 person-years) occurring in the Latin American cohort; no trend according to age group was observed. The incidence of dengue hemorrhagic fever was less than 0.3 episodes per 100 person-years in each cohort. The percentage of VCD episodes requiring hospitalization was 19.1% in the Asian cohort and 11.1% in the Latin American cohort. In comparable age groups (9 to 12 years and 13 to 16 years), the burden of dengue was higher in Asia than in Latin America.
    CONCLUSIONS: The burdens of dengue were substantial in the two regions and in all age groups. Burdens varied widely according to country, but the rates were generally higher and the disease more frequently severe in Asian countries than in Latin American countries. (Funded by Sanofi Pasteur; CYD14 and CYD15 ClinicalTrials.gov numbers, NCT01373281 and NCT01374516.).
    Note: Malaysia is a study site (CYD14 Primary Study Group authors: HIHJMI, Pediatric Institute, Kuala Lumpur Hospital, Kuala Lumpur; RN, Department of Paediatrics, Hospital Pulau Pinang, Pulau Pinang, Malaysia)
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  5. Perera D, Shimizu H, Yoshida H, Tu PV, Ishiko H, McMinn PC, et al.
    J Med Virol, 2010 Apr;82(4):649-57.
    PMID: 20166171 DOI: 10.1002/jmv.21652
    The VP4, VP2, and VP1 gene regions were evaluated for their usefulness in typing human enteroviruses. Three published RT-PCR primers sets targeting separately these three gene regions were used. Initially, from a total of 86 field isolates (36 HEV-A, 40 HEV-B, and 10 HEV-C) tested, 100% concordance in HEV-A was identified from all three gene regions (VP4, VP2, and VP1). However, for HEV-B and HEV-C viruses, only the VP2 and VP1 regions, and not VP4, showed 100% concordance in typing these viruses. To evaluate further the usefulness of VP4 in typing HEV-A enteroviruses, 55 Japanese and 203 published paired VP4 and VP1 nucleotide sequences were also examined. In each case, typing by VP4 was 100% in concordance with typing using VP1. Given these results, it is proposed that for HEV-A enteroviruses, all three gene regions (VP4, VP2, and VP1), would be useful for typing these viruses. These options would enhance the capability of laboratories in identifying these viruses and would greatly help in outbreaks of hand, foot, and mouth disease.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
  6. Perera D, Podin Y, Akin W, Tan CS, Cardosa MJ
    BMC Infect Dis, 2004 May 4;4:11.
    PMID: 15122971
    Human enterovirus 71 has emerged as an important pathogen in the Asia Pacific region and it is important to be able to make a rapid and specific diagnosis for outbreak control. Recent Asian strains of Coxsackievirus A16 have changes in the VP1 gene which causes mispriming of widely used primers for human enterovirus 71 specific identification.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
  7. Podin Y, Gias EL, Ong F, Leong YW, Yee SF, Yusof MA, et al.
    BMC Public Health, 2006 Jul 07;6:180.
    PMID: 16827926
    BACKGROUND: A major outbreak of human enterovirus 71-associated hand, foot and mouth disease in Sarawak in 1997 marked the beginning of a series of outbreaks in the Asia Pacific region. Some of these outbreaks had unusually high numbers of fatalities and this generated much fear and anxiety in the region.

    METHODS: We established a sentinel surveillance programme for hand, foot and mouth disease in Sarawak, Malaysia, in March 1998, and the observations of the first 7 years are described here. Virus isolation, serotyping and genotyping were performed on throat, rectal, vesicle and other swabs.

    RESULTS: During this period Sarawak had two outbreaks of human enterovirus 71, in 2000 and 2003. The predominant strains circulating in the outbreaks of 1997, 2000 and 2003 were all from genogroup B, but the strains isolated during each outbreak were genetically distinct from each other. Human enterovirus 71 outbreaks occurred in a cyclical pattern every three years and Coxsackievirus A16 co-circulated with human enterovirus 71. Although vesicles were most likely to yield an isolate, this sample was not generally available from most cases and obtaining throat swabs was thus found to be the most efficient way to obtain virological information.

    CONCLUSION: Knowledge of the epidemiology of human enterovirus 71 transmission will allow public health personnel to predict when outbreaks might occur and to plan interventions in an effective manner in order to reduce the burden of disease.

    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  8. Boyle DB, Taylor T, Cardoso M
    Aust. Vet. J., 2004 Jul;82(7):421-5.
    PMID: 15354851
    OBJECTIVE: To evaluate and implement rapid molecular diagnostic techniques for the detection of foot and mouth disease virus (FMDV) suitable for use in Australia.

    DESIGN: Two PCR TaqMan assays targeted to the FMDV internal ribosome entry site or the 3D polymerase coding region for the rapid detection of FMDV were evaluated using non-infectious materials to determine the test most appropriate for implementation as part of Australia's national preparedness for the rapid detection and diagnosis of FMD outbreaks.

    RESULTS: Two published tests (PCR TaqMan assays targeted to the FMDV IRES region or the FMDV 3D polymerase coding region) were evaluated for their ability to detect FMDV genetic material in non-infectious FMDV ELISA antigen stocks held at Australian Animal Health Laboratory. Both tests were able to detect FMDV genetic material from strains O1 Manisa, O-3039, A22, A24, A Malaysia, C, Asia 1 and SAT 1, 2 and 3. With the exception of Asia 1, the TaqMan assay targeted to the FMD 3D polymerase coding region had Ct values equal to or lower than for the TaqMan assay targeted to the IRES region suggesting that this test may provide broader serotype detection and sensitivity. However, the TaqMan assay directed to the FMDV IRES is the only one to date to have undergone substantial evaluation using clinical samples collected during an outbreak. The greatest differences observed were for O-3039, SAT 1, and 3.

    CONCLUSION: Given the ease of setting up both tests, AAHL currently runs both tests on highly suspect FMD investigations to provide independent confirmation of the absence of FMDV because the tests are focused on two independent regions of the FMDV genome. These tests add substantially to Australia's preparedness for FMD diagnosis complementing the already well-established virus isolation and antigen capture ELISA tests for index case diagnosis of FMD in Australia.

    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods; Reverse Transcriptase Polymerase Chain Reaction/veterinary*
  9. Salleh MN, Ismail P, Abdullah AS, Taufiq-Yap YH, Carmichael P
    IUBMB Life, 2004 Jul;56(7):409-16.
    PMID: 15545218
    Studies with clastogenic carcinogen diethylstilbestrol (DES) resulted in a broad of spectrum of toxic and carcinogenic effects in humans and rodents, but the cellular and molecular mechanism(s) by which it induces cancer is not clear. To identify putative genetic targets for p53 in vivo, we applied the cDNA macroarray gene expression profiles associated with apoptosis by comparing p53+/- knockout mice and wild-type mice on the kidney and uterus of female mice. p53+/- knockout mice and wild-type mice were treated with DES (500 micromole kg(-1)) or vehicle i.p once daily for 4 days. Total RNAs were obtained from kidney and uterus of both control and DES-treated. The signal intensities of individual gene spots on the membrane were quantified and normalized to the expression level of the GAPDH gene as an internal control. Our results demonstrated that 16 genes; bad, bax, bcl-2, bcl-w, bcl-x, caspase-3, caspase-7, caspase-8, c-myc, E124, GADD45, mdm2, NKkappab1, p53, p21, Rb and trail were up-regulated and six genes; caspase-1, caspase-2, DR5, E2F1, FasL and iNOS did not changed in response to DES treatment in wild-type mice compared to p53+/- knockout mice. Most genes are involved in cell cycle regulation, signal transduction, apoptosis, or transcription. The greatest changes were seen in bad, bcl-x, mdm2, p53 and p21 gene expression in wild-type mice compared to p53+/- knockout mice. In comparing p53 and p21 gene expression in wild-type mice and p53+/- knockout mice, there was an 4.4-fold vs. 1.8-fold; 8-fold vs. 5.2-fold for kidney and 16-fold vs. 5.5-fold; 2.1-fold vs. 8.3-fold for uterus samples increase in induction (respectively). RT-PCR and densitometric analysis was used to confirm the biggest changes of p21, p53 and bax genes. Using this approach, we have identified apoptosis associated genes regulated in response to DES and have revealed putative differences between the isogenic parent strain and p53+/- knockout mice, which will contribute to a better understanding of toxicity/carcinogenicity mechanisms in this model.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  10. Yee W, Abdul-Kadir R, Lee LM, Koh B, Lee YS, Chan HY
    3 Biotech, 2018 Aug;8(8):354.
    PMID: 30105179 DOI: 10.1007/s13205-018-1381-1
    In this work, a simple and inexpensive physical lysis method using a cordless drill fitted with a plastic pellet pestle and 150 mg of sterile sea sand was established for the extraction of DNA from six strains of freshwater microalgae. This lysis method was also tested for RNA extraction from two microalgal strains. Lysis duration between 15 and 120 s using the cetyltrimethyl ammonium bromide (CTAB) buffer significantly increased the yield of DNA from four microalgalstrains (Monoraphidium griffithii NS16, Scenedesmus sp. NS6, Scenedesmus sp. DPBC1 and Acutodesmus sp. DPBB10) compared to control. It was also found that grinding was not required to obtain DNA from two strains of microalgae (Choricystis sp. NPA14 and Chlamydomonas sp. BM3). The average DNA yield obtained using this lysis method was between 62.5 and 78.9 ng/mg for M. griffithii NS16, 42.2-247.0 ng/mg for Scenedesmus sp. NS6, 70.2-110.9 ng/mg for Scenedesmus sp. DPBC1 and 142.8-164.8 ng/mg for Acutodesmus sp. DPBB10. DNA obtained using this method was sufficiently pure for PCR amplification. Extraction of total RNA from M. griffithii NS16 and Mychonastes sp. NPD7 using this lysis method yielded high-quality RNA suitable for RT-PCR. This lysis method is simple, cheap and would enable rapid nucleic acid extraction from freshwater microalgae without requiring costly materials and equipment such as liquid nitrogen or beadbeaters, and would facilitate molecular studies on microalgae in general.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  11. Fu JYL, Chong YM, Sam IC, Chan YF
    J Virol Methods, 2022 Mar;301:114462.
    PMID: 35026305 DOI: 10.1016/j.jviromet.2022.114462
    Emerging SARS-CoV-2 variants of concern (VOC) have been associated with enhanced transmissibility and immune escape. Next-generation sequencing (NGS) of the whole genome is the gold standard for variant identification for surveillance but is time-consuming and costly. Rapid and cost-effective assays that detect SARS-CoV-2 variants are needed. We evaluated Allplex SARS-CoV-2 Master Assay and Variants I Assay to detect HV69/70 deletion, Y144 deletion, E484K, N501Y, and P681H spike mutations in 248 positive samples collected in Kuala Lumpur, Malaysia, between January and May 2021. Spike variants were detected in 78/248 (31.5 %), comprising 60 VOC B.1.351 (beta) and 18 B.1.1.7 (alpha). With NGS as reference for 115 samples, the sensitivity for detecting the spike mutations was 98.7 % with the Master Assay and 100 % with the Variants I Assay. The emergence of beta variants correlated with increasing COVID-19 infections in Malaysia. The prevalence of alpha VOC and lineage B.1.466.2 was low. These assays detect mutations present in alpha, beta and gamma VOCs. Of the VOCs which have subsequently emerged, the assays should detect omicron (B.1.1.529) but not B.1.617.2 (delta). In conclusion, spike variant PCR assays can be used to rapidly monitor selected SARS-CoV-2 VOCs in resource-limited settings, but require updates as new variants emerge.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  12. Abubakar S, Shafee N, Chee HY
    Malays J Pathol, 1998 Dec;20(2):71-81.
    PMID: 10879266
    Identification of the aetiologic agent(s) associated with an outbreak of fatal childhood viral infection in Sarawak, Malaysia, in mid 1997 remains elusive. It is reported here that African green monkey kidney (Vero) and human monocytic (U937) cells treated with inocula derived from clinical specimens of some of these fatal cases showed the presence of cellular genomic DNA degradation when the extracted DNA was separated by pulsed field gel electrophoresis (PFGE), oligonucleosomal DNA ladders characteristic of apoptotic cells when the infected cells' DNA was separated by agarose gel electrophoresis, and apoptotic cellular DNA fragmentation when cells were stained using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL). These results suggest that inocula derived from the patients' clinical specimens contain factors which stimulate apoptotic cellular responses in vitro.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  13. Suppiah J, Ching SM, Amin-Nordin S, Mat-Nor LA, Ahmad-Najimudin NA, Low GK, et al.
    PLoS Negl Trop Dis, 2018 09;12(9):e0006817.
    PMID: 30226880 DOI: 10.1371/journal.pntd.0006817
    BACKGROUND: Malaysia experienced an unprecedented dengue outbreak from the year 2014 to 2016 that resulted in an enormous increase in the number of cases and mortality as compared to previous years. The causes that attribute to a dengue outbreak can be multifactorial. Viral factors, such as dengue serotype and genotype, are the components of interest in this study. Although only a small number of studies investigated the association between the serotype of dengue virus and clinical manifestations, none of these studies included analyses on dengue genotypes. The present study aims to investigate dengue serotype and genotype-specific clinical characteristics among dengue fever and severe dengue cases from two Malaysian tertiary hospitals between 2014 and mid-2017.

    METHODOLOGY AND PRINCIPAL FINDINGS: A total of 120 retrospective dengue serum specimens were subjected to serotyping and genotyping by Taqman Real-Time RT-PCR, sequencing and phylogenetic analysis. Subsequently, the dengue serotype and genotype data were statistically analyzed for 101 of 120 corresponding patients' clinical manifestations to generate a descriptive relation between the genetic components and clinical outcomes of dengue infected patients. During the study period, predominant dengue serotype and genotype were found to be DENV 1 genotype I. Additionally, non-severe clinical manifestations were commonly observed in patients infected with DENV 1 and DENV 3. Meanwhile, patients with DENV 2 infection showed significant warning signs and developed severe dengue (p = 0.007). Cases infected with DENV 2 were also commonly presented with persistent vomiting (p = 0.010), epigastric pain (p = 0.018), plasma leakage (p = 0.004) and shock (p = 0.038). Moreover, myalgia and arthralgia were highly prevalent among DENV 3 infection (p = 0.015; p = 0.014). The comparison of genotype-specific clinical manifestations showed that DENV 2 Cosmopolitan was significantly common among severe dengue patients. An association was also found between genotype I of DENV 3 and myalgia. In a similar vein, genotype III of DENV 3 was significantly common among patients with arthralgia.

    CONCLUSION: The current data contended that different dengue serotype and genotype had caused distinct clinical characteristics in infected patients.

    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  14. Wu WH, Kuo TC, Lin YT, Huang SW, Liu HF, Wang J, et al.
    PLoS One, 2013;8(12):e83711.
    PMID: 24391812 DOI: 10.1371/journal.pone.0083711
    Enterovirus 71 (EV71), a causative agent of hand, foot, and mouth disease can be classified into three genotypes and many subtypes. The objectives of this study were to conduct a molecular epidemiological study of EV71 in the central region of Taiwan from 2002-2012 and to test the hypothesis that whether the alternative appearance of different EV71 subtypes in Taiwan is due to transmission from neighboring countries or from re-emergence of pre-existing local strains. We selected 174 EV71 isolates and used reverse transcription-polymerase chain reaction to amplify their VP1 region for DNA sequencing. Phylogenetic analyses were conducted using Neighbor-Joining, Maximum Likelihood and Bayesian methods. We found that the major subtypes of EV71 in Taiwan were B4 for 2002 epidemic, C4 for 2004-2005 epidemic, B5 for 2008-2009 epidemic, C4 for 2010 epidemic and B5 for 2011-2012 epidemic. Phylogenetic analysis demonstrated that the 2002 and 2008 epidemics were associated with EV71 from Malaysia and Singapore; while both 2010 and 2011-2012 epidemics originated from different regions of mainland China including Shanghai, Henan, Xiamen and Gong-Dong. Furthermore, minor strains have been identified in each epidemic and some of them were correlated with the subsequent outbreaks. Therefore, the EV71 infection in Taiwan may originate from pre-existing minor strains or from other regions in Asia including mainland China. In addition, 101 EV71 isolates were selected for the detection of new recombinant strains using the nucleotide sequences spanning the VP1-2A-2B region. No new recombinant strain was found. Analysis of clinical manifestations showed that patients infected with C4 had significantly higher rates of pharyngeal vesicles or ulcers than patients infected with B5. This is the first study demonstrating that different EV 71 genotypes may have different clinical manifestations and the association of EV71 infections between Taiwan and mainland China.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  15. Teoh PL, Cheng AY, Liau M, Lem FF, Kaling GP, Chua FN, et al.
    Pharm Biol, 2017 Dec;55(1):394-401.
    PMID: 27931178
    CONTEXT: Clinacanthus nutans Lindau (Acanthaceae) is a medicinal plant that has been reported to have anti-inflammatory, antiviral, antimicrobial and antivenom activities. In Malaysia, it has been widely claimed to be effective in various cancer treatments but scientific evidence is lacking.

    OBJECTIVE: This study investigates the chemical constituents, anti-proliferative, and apoptotic properties of C. nutans root extracts.

    MATERIALS AND METHODS: The roots were subjected to solvent extraction using methanol and ethyl acetate. The anti-proliferative effects of root extracts were tested at the concentrations of 10 to 50 μg/mL on MCF-7 and HeLa by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for 72 h. Morphological changes were observed under light microscope. Pro-apoptotic effects of root extracts were examined using flow cytometric analysis and RT-PCR. The chemical compositions of root extracts were detected using GC-MS.

    RESULTS: The proliferation of MCF-7 cells was inhibited with the IC50 values of 35 and 30 μg/mL, respectively, for methanol and ethyl acetate root extracts. The average inhibition of HeLa cells was ∼25%. Induction of apoptosis in MCF-7 was supported by chromatin condensation, down-regulation of BCL2 and unaltered expression of BAX. However, only ethyl acetate extract caused the loss of mitochondrial membrane potential. GC-MS analysis revealed the roots extracts were rich with terpenoids and phytosterols.

    DISCUSSION AND CONCLUSIONS: The results demonstrated that root extracts promote apoptosis by suppressing BCL2 via mitochondria-dependent or independent manner. The identified compounds might work solely or cooperatively in regulating apoptosis. However, further studies are required to address this.

    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  16. Teoh, P.H., Kuah, M.K., Lim, P.S., Muhammand, T.S.T., Najimudin, N., Chien, A.S.C.
    ASM Science Journal, 2010;4(2):123-132.
    MyJurnal
    The receptor-interacting protein 140 (RIP 140) is a well known nuclear repressor and has been shown to be crucial for female reproduction and metabolism. However, the function of this repressor in developmental processes is still unknown. We conducted a study to investigate the expression patterns of RIP 140 in developing zebrafish embryos. Semi-quantitative RT-PCR analysis revealed that RIP140 was highly expressed in the eye, swim bladder, reproductive and metabolic organs of adult zebrafish. During embryogenesis, RIP 140 mRNA was continuously expressed throughout all the developmental stages with the highest expression at 24 hours of post-fertilization (hpf). Furthermore, in situ hybridization whole-mounts revealed that the expression of this gene was mainly localized in the eyes, mid-brain, pectoral fin buds and somites. Therefore, this present study has provided a starting point for future investigations to examine the role of RIP 140 in the development of these organs.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  17. Lau YL, Fong MY, Idris MM, Ching XT
    PMID: 23082548
    Detection of Toxoplasma gondii infection is essential in pregnant women and immunosuppressed patients. Numerous studies have shown that the recombinant production of several Toxoplasma antigens, including dense granule antigens (GRAs) has high potential as diagnostic reagents. In the present study, we produced GRA2 using Pichia pastoris system. RNA of T. gondii RH strain tachyzoite was used as a template to produce cDNA clones of full-length GRA2 via reverse transcriptase PCR. Amplicons were inserted into pPICZalpha A and the recombinant plasmid transformed into P. pastoris, X-33 strain. The expressed recombinant protein was identified by SDS-PAGE and Western blotting. A recombinant protein of -28 kDa was produced, which could be detected by toxoplasmosis positive human sera indicating that the recombinant protein retained its antigenicity. The present study indicates that P. pastoris-expressed GRA2 should be useful for detection of Toxoplasma infection.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  18. Yong VC, Ong KW, Sidik SM, Rosli R, Chong PP
    J Microbiol Methods, 2009 Nov;79(2):242-5.
    PMID: 19737582 DOI: 10.1016/j.mimet.2009.08.019
    In situ Reverse Transcriptase PCR (in situ RT-PCR) can amplify mRNA and localize gene expression in cells. However, this method is not feasible in fungi as the thick fungal cell wall constitutes a barrier to this procedure. We developed a two step in situ RT-PCR procedure which enabled the detection and localization of Candida tropicalis mRNA expression in formalin-fixed, paraffin-embedded (FFPE) mouse kidney sections. This in situ hybridization study revealed the first direct evidence for deposition of Candida tropicalis secreted aspartic proteinase 2 (CtSAP2) in the tip of pseudohyphae and its involvement in acute systemic candidiasis. We conclude that in situ RT-PCR can be successfully applied to FFPE tissues and will offer new perspectives in studying gene expression in Candida species.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction/methods*
  19. Looi CY, D' Silva EC, Seow HF, Rosli R, Ng KP, Chong PP
    FEMS Microbiol Lett, 2005 Aug 15;249(2):283-9.
    PMID: 16006060
    The aims of our research were to investigate the gene expression of the multidrug efflux transporter, CDR1 and the major drug facilitator superfamily transporter, MDR1 gene in azole drug-resistant Candida albicans and Candida glabrata clinical isolates recovered from vaginitis patients; and to identify hotspot mutations that may be present in the C. albicans CaCDR1 gene that could be associated with drug-resistance. The relative expression of the CDR1 and MDR1 transcripts in ketoconazole and clotrimazole-resistant isolates and drug-susceptible ATCC strains were determined by semi-quantitative reverse transcription-polymerase chain reaction. Expression of CaCDR1 transcript was upregulated to varying extents in all three azole-resistant C. albicans isolates studied (1.6-, 3.7- and 3.9-fold) and all three C. glabrata isolates tested (at 1.9-, 2.3- and 2.7-fold). The overexpression level of CaCDR1 in the isolates correlated with the degree of resistance as reflected by the minimum inhibitory concentration (MIC) of the drugs. The messenger RNA for another efflux pump, MDR1, was also overexpressed in one of the azole-resistant C. albicans isolates that overexpressed CDR1. This finding suggests that drug-resistance may involve synergy between energy-dependent drug efflux pumps CDR1p and MDR1p in some but not all isolates. Interestingly, DNA sequence analysis of the promoter region of the CaCDR1 gene revealed several point mutations in the resistant clinical isolates compared to the susceptible isolates at 39, 49 and 151 nucleotides upstream from the ATG start codon. This finding provides new information on point mutations in the promoter region which may be responsible for the overexpression of CDR1 in drug-resistant isolates.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  20. Alizadeh F, Abdullah SN, Khodavandi A, Abdullah F, Yusuf UK, Chong PP
    J Plant Physiol, 2011 Jul 01;168(10):1106-13.
    PMID: 21333381 DOI: 10.1016/j.jplph.2010.12.007
    The expression profiles of Δ9 stearoyl-acyl carrier protein desaturase (SAD1 and SAD2) and type 3 metallothionein (MT3-A and MT3-B) were investigated in seedlings of oil palm (Elaeis guineensis) artificially inoculated with the pathogenic fungus Ganoderma boninense and the symbiotic fungus Trichoderma harzianum. Expression of SAD1 and MT3-A in roots and SAD2 in leaves were significantly up-regulated in G. boninense inoculated seedlings at 21 d after treatment when physical symptoms had not yet appeared and thereafter decreased to basal levels when symptoms became visible. Our finding demonstrated that the SAD1 expression in leaves was significantly down-regulated to negligible levels at 42 and 63 d after treatment. The transcripts of MT3 genes were synthesized in G. boninense inoculated leaves at 42 d after treatment, and the analyses did not show detectable expression of these genes before 42 d after treatment. In T. harzianum inoculated seedlings, the expression levels of SAD1 and SAD2 increased gradually and were stronger in roots than leaves, while for MT3-A and MT3-B, the expression levels were induced in leaves at 3d after treatment and subsequently maintained at same levels until 63d after treatment. The MT3-A expression was significantly up-regulated in roots at 3d after treatment and thereafter were maintained at this level. Both SAD and MT3 expression were maintained at maximum levels or at levels higher than basal. This study demonstrates that oil palm was able to distinguish between pathogenic and symbiotic fungal interactions, thus resulting in different transcriptional activation profiles of SAD and MT3 genes. Increases in expression levels of SAD and MT3 would lead to enhanced resistance against G. boninense and down-regulation of genes confer potential for invasive growth of the pathogen. Differences in expression profiles of SAD and MT3 relate to plant resistance mechanisms while supporting growth enhancing effects of symbiotic T. harzianum.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
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