Displaying publications 21 - 40 of 79 in total

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  1. Masilamani R, Darus A, Ting AS, Ali R, Awang Mahmud AB, Koh D
    Asia Pac J Public Health, 2012 Mar;24(2):278-87.
    PMID: 21385771 DOI: 10.1177/1010539510393725
    The aim of this study was to determine the prevalence of job stress among secondary school teachers using Karasek Job Content Questionnaire (JCQ), the association between salivary cortisol, salivary IgA, and sociodemographic characteristics, and the association between log cortisol, IgA levels, and job strain categories. A cross-sectional study was undertaken using JCQ and salivary cortisol and IgA samples. Cluster sampling was done yielding 302 respondents. The prevalence of stress among all teachers was 20.2%. Being a Malay, teaching experience of 5 to 10 years, and those without a supervisor's support had higher prevalence of high job strain. Teachers in the 31 to 40 years age bracket, educating handicapped children with the absence of supervisor support exhibited higher stress levels with lower log salivary IgA levels. Further studies must be conducted using salivary biomarkers to study the in-depth relationship of stress, extending into other occupational groups.
    Matched MeSH terms: Biomarkers/analysis
  2. Leong YH, Latiff AA, Ahmad NI, Rosma A
    Mycotoxin Res, 2012 May;28(2):79-87.
    PMID: 23606045 DOI: 10.1007/s12550-012-0129-8
    Aflatoxins are highly toxic secondary fungal metabolites mainly produced by Aspergillus flavus and A. parasiticus. Human exposure to aflatoxins may result directly from ingestion of contaminated foods, or indirectly from consumption of foods from animals previously exposed to aflatoxins in feeds. This paper focuses on exposure measurement of aflatoxins and aflatoxin metabolites in various human body fluids. Research on different metabolites present in blood, urine, breast milk, and other human fluids or tissues including their detection techniques is reviewed. The association between dietary intake of aflatoxins and biomarker measurement is also highlighted. Finally, aspects related to the differences between aflatoxin determination in food versus the biomarker approach are discussed.
    Matched MeSH terms: Biomarkers/analysis*
  3. Wan Hassan WN, Stephenson PA, Waddington RJ, Sloan AJ
    J Dent, 2012 May;40(5):406-15.
    PMID: 22342686 DOI: 10.1016/j.jdent.2012.02.002
    Root resorption is a ubiquitous although undesirable sequela to orthodontic treatment. Current methods to investigate the pathophysiology have certain limitations. In pursuit to understand and develop treatment modalities for orthodontically induced root resorption, the ability to manipulate cells within their natural extracellular matrix in a three dimensional organotypic model is invaluable. The study aimed to develop a laboratory-based organotypic model to investigate the effect of orthodontic forces on the periodontium.
    Matched MeSH terms: Biomarkers/analysis
  4. Karami A, Syed MA, Christianus A, Willett KL, Mazzeo JR, Courtenay SC
    J Hazard Mater, 2012 Jul 15;223-224:84-93.
    PMID: 22608400 DOI: 10.1016/j.jhazmat.2012.04.051
    In this study we sought to optimize recovery of fluorescent aromatic compounds (FACs) from the bile of African catfish (Clarias gariepinus) injected with 10mg/kg benzo[a]pyrene (BaP). Fractions of pooled bile were hydrolyzed, combined with ten volumes of methanol, ethanol, acetonitrile, or acetone, centrifuged and supernatants were analyzed by high-performance liquid chromatography with fluorescent detection (HPLC/FL). As well, to test whether FACs were being lost in solids from the centrifugation, pellets were resuspended, hydrolyzed and mixed with six volumes of the organic solvent that produced best FAC recovery from the supernatant, and subjected to HPLC/FL. Highest FAC concentrations were obtained with 2000μl and 1250μl acetone for supernatants and resuspended pellets respectively. FACs concentrations were negatively correlated with biliary protein content but were unaffected by addition of bovine serum albumin (BSA) followed by no incubation indicating that the presence of proteins in the biliary mixture does not simply interfere with detection of FACs. In another experiment, efficiency of acetone addition was compared to two different liquid-liquid extractions (L-LEs). Acetone additions provided significantly higher biliary FACs than the L-LE methods. The new two-stage bile preparation with acetone is an efficient, inexpensive and easily performed method.
    Matched MeSH terms: Biomarkers/analysis
  5. Naidu KR, Kumar KS, Arulselvan P, Reddy CB, Lasekan O
    Arch Pharm (Weinheim), 2012 Dec;345(12):957-63.
    PMID: 23015406 DOI: 10.1002/ardp.201200192
    A series of α-hydroxyphosphonates were synthesized from the reaction of aldehyde (1) with triethylphosphite (2) in the presence of oxone and evaluated for their antioxidant properties against lipid peroxidation, reduced glutathione, superoxide dismutase, and catalase. The majority of the compounds showed promising antioxidant activity. Diethyl anthracen-9-yl (hydroxy) methylphosphonate (3n) is the most potent and biologically active compound against free radicals.
    Matched MeSH terms: Biomarkers/analysis
  6. Liew SC, Das-Gupta E, Chakravarthi S, Wong SF, Lee N, Safdar N, et al.
    BMC Res Notes, 2012;5:201.
    PMID: 22537619 DOI: 10.1186/1756-0500-5-201
    Angiogenesis has been reported to be one of the contributory factors to the pathogenesis of psoriasis vulgaris. This study aims to compare the expression of different angiogenesis growth factors namely (1) the vascular endothelial growth factor (VEGF) subfamily: A, B, C, D and placenta growth factor (PlGF); (2) nerve growth factor (NGF) and (3) von Willebrand factor (vWFr) in the skins of patients with psoriasis vulgaris and non-psoriatic volunteers.

    Study site: Dermatology Department of Hospital Kuala Lumpur, Kuala Lumpur and Tuanku Ja’afar Hospital, Seremban, Malaysia
    Matched MeSH terms: Biomarkers/analysis
  7. Ellias MF, Zainal Ariffin SH, Karsani SA, Abdul Rahman M, Senafi S, Megat Abdul Wahab R
    ScientificWorldJournal, 2012;2012:647240.
    PMID: 22919344 DOI: 10.1100/2012/647240
    Orthodontic treatment has been shown to induce inflammation, followed by bone remodelling in the periodontium. These processes trigger the secretion of various proteins and enzymes into the saliva. This study aims to identify salivary proteins that change in expression during orthodontic tooth movement. These differentially expressed proteins can potentially serve as protein biomarkers for the monitoring of orthodontic treatment and tooth movement. Whole saliva from three healthy female subjects were collected before force application using fixed appliance and at 14 days after 0.014'' Niti wire was applied. Salivary proteins were resolved using two-dimensional gel electrophoresis (2DE) over a pH range of 3-10, and the resulting proteome profiles were compared. Differentially expressed protein spots were then identified by MALDI-TOF/TOF tandem mass spectrometry. Nine proteins were found to be differentially expressed; however, only eight were identified by MALDI-TOF/TOF. Four of these proteins-Protein S100-A9, immunoglobulin J chain, Ig alpha-1 chain C region, and CRISP-3-have known roles in inflammation and bone resorption.
    Matched MeSH terms: Biomarkers/analysis*
  8. Makpol S, Zainuddin A, Chua KH, Yusof YA, Ngah WZ
    Clinics (Sao Paulo), 2012;67(2):135-43.
    PMID: 22358238
    OBJECTIVE: Human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. The beneficial effects of vitamin E in aging have been established, but studies to determine the mechanisms of these effects are ongoing. This study determined the molecular mechanism of γ-tocotrienol, a vitamin E homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes.

    METHODS: Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer.

    RESULTS: The cell cycle was arrested in the G(0)/G(1) phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G(0)/G(1) phase and increased cell populations in the G(2)/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts.

    CONCLUSION: γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.

    Matched MeSH terms: Biomarkers/analysis
  9. Karami A, Keiter S, Hollert H, Courtenay SC
    Environ Sci Pollut Res Int, 2013 Mar;20(3):1586-95.
    PMID: 22752811 DOI: 10.1007/s11356-012-1027-5
    This study represents a first attempt at applying a fuzzy inference system (FIS) and an adaptive neuro-fuzzy inference system (ANFIS) to the field of aquatic biomonitoring for classification of the dosage and time of benzo[a]pyrene (BaP) injection through selected biomarkers in African catfish (Clarias gariepinus). Fish were injected either intramuscularly (i.m.) or intraperitoneally (i.p.) with BaP. Hepatic glutathione S-transferase (GST) activities, relative visceral fat weights (LSI), and four biliary fluorescent aromatic compounds (FACs) concentrations were used as the inputs in the modeling study. Contradictory rules in FIS and ANFIS models appeared after conversion of bioassay results into human language (rule-based system). A "data trimming" approach was proposed to eliminate the conflicts prior to fuzzification. However, the model produced was relevant only to relatively low exposures to BaP, especially through the i.m. route of exposure. Furthermore, sensitivity analysis was unable to raise the classification rate to an acceptable level. In conclusion, FIS and ANFIS models have limited applications in the field of fish biomarker studies.
    Matched MeSH terms: Biomarkers/analysis
  10. Khalilpour A, Santhanam A, Wei LC, Saadatnia G, Velusamy N, Osman S, et al.
    Asian Pac J Cancer Prev, 2013;14(3):1635-42.
    PMID: 23679248
    Helicobacter pylori antigen was prepared from an isolate from a patient with a duodenal ulcer. Serum samples were obtained from culture-positive H. pylori infected patients with duodenal ulcers, gastric ulcers and gastritis (n=30). As controls, three kinds of sera without detectable H. pylori IgG antibodies were used: 30 from healthy individuals without history of gastric disorders, 30 from patients who were seen in the endoscopy clinic but were H. pylori culture negative and 30 from people with other diseases. OFF-GEL electrophoresis, SDS-PAGE and Western blots of individual serum samples were used to identify protein bands with good sensitivity and specificity when probed with the above sera and HRP-conjugated anti-human IgG. Four H. pylori protein bands showed good (≥ 70%) sensitivity and high specificity (98-100%) towards anti-Helicobacter IgG antibody in culture- positive patients sera and control sera, respectively. The identities of the antigenic proteins were elucidated by mass spectrometry. The relative molecular weights and the identities of the proteins, based on MALDI TOF/ TOF, were as follows: CagI (25 kDa), urease G accessory protein (25 kDa), UreB (63 kDa) and proline/pyrroline- 5-carboxylate dehydrogenase (118 KDa). These identified proteins, singly and/or in combinations, may be useful for diagnosis of H. pylori infection in patients.
    Matched MeSH terms: Biomarkers/analysis*
  11. Loy SL, Jan Mohamed HJ
    Women Health, 2014;54(2):145-60.
    PMID: 24329183 DOI: 10.1080/03630242.2013.870632
    This study aimed to examine the associations among prenatal nicotine exposure, oxidative stress, and postpartum visceral fat among women exposed to secondhand smoke (SHS). The study was conducted in Kelantan, Malaysia, from April 2010 to December 2012. Blood samples were collected in the second and third trimesters from 135 healthy pregnant women who were followed-up at delivery, 2 months, 6 months and 12 months postpartum. Maternal hair nicotine and oxidative stress markers during pregnancy were measured. Visceral fat was assessed by bioelectrical impedance. Multiple linear regression analysis revealed that maternal hair nicotine concentration was associated with increased DNA damage (tail moment: β=0.580, p=0.001) and decreased glutathione peroxidase (β=-12.100; p=0.009) in the second trimester of pregnancy. Increased DNA damage, protein oxidation and total antioxidant capacity in the second trimester were associated with 2, 6, and 12 months postpartum visceral fat. No direct association was found between prenatal hair nicotine level and postpartum visceral fat; however, these results suggest that any relation of SHS to visceral adiposity may be indirect, mediated via enhanced oxidative stress.
    Matched MeSH terms: Biomarkers/analysis
  12. Siar CH, Ishak I, Ng KH
    J Oral Pathol Med, 2015 Jan;44(1):51-8.
    PMID: 25059841 DOI: 10.1111/jop.12203
    Ameloblastoma is a benign but locally infiltrative odontogenic epithelial neoplasm with a high risk for recurrence. Podoplanin, a lymphatic endothelium marker, putatively promotes collective cell migration and invasiveness in this neoplasm. However, its role in the recurrent ameloblastoma (RA) remains unclear. As morphological, signaling, and genetic differences may exist between primary and recurrent tumors, clarification of their distribution patterns is of relevance.
    Matched MeSH terms: Biomarkers/analysis
  13. Chieng S, Mohamed R, Nathan S
    Microb Pathog, 2015 Feb;79:47-56.
    PMID: 25616255 DOI: 10.1016/j.micpath.2015.01.006
    Burkholderia pseudomallei, the causative agent of melioidosis, is able to survive extreme environments and utilizes various virulence factors for survival and pathogenicity. To compete and survive within these different ecological niches, B. pseudomallei has evolved specialized pathways, including the Type VI secretion systems (T6SSs), that have a role in pathogenesis as well as interbacterial interactions. We examined the expression profile of B. pseudomallei T6SS six gene clusters during infection of U937 macrophage cells. T6SS-5 was robustly transcribed while the other five clusters were not significantly regulated proposing the utility of T6SS-5 as a potential biomarker of exposure to B. pseudomallei. Transcription of T6SS regulators VirAG and BprB was also not significant during infection when compared to bacteria grown in culture. Guided by these findings, three highly expressed T6SS genes, tssJ-4, hcp1 and tssE-5, were expressed as recombinant proteins and screened against melioidosis patient sera by western analysis and ELISA. Only Hcp1 was reactive by both types of analysis. The recombinant Hcp1 protein was further evaluated against a cohort of melioidosis patients (n = 32) and non-melioidosis individuals (n = 20) sera and the data clearly indicates a higher sensitivity (93.7%) and specificity (100%) for Hcp1 compared to bacterial lysate. The detection of anti-Hcp1 antibodies in patients' sera indicating the presence of B. pseudomallei highlights the potential of Hcp1 to be further developed as a serodiagnostic marker for melioidosis.
    Matched MeSH terms: Biomarkers/analysis*
  14. Alsalahi MA, Latif MT, Ali MM, Dominick D, Khan MF, Mustaffa NI, et al.
    Mar Pollut Bull, 2015 Apr 15;93(1-2):278-83.
    PMID: 25682566 DOI: 10.1016/j.marpolbul.2015.01.011
    This study aims to determine the concentration of sterols used as biomarkers in the surface microlayer (SML) in estuarine areas of the Selangor River, Malaysia. Samples were collected during different seasons through the use of a rotation drum. The analysis of sterols was performed using gas chromatography equipped with a flame ionisation detector (GC-FID). The results showed that the concentrations of total sterols in the SML ranged from 107.06 to 505.55 ng L(-1). The total sterol concentration was found to be higher in the wet season. Cholesterol was found to be the most abundant sterols component in the SML. The diagnostic ratios of sterols show the influence of natural sources and waste on the contribution of sterols in the SML. Further analysis, using principal component analysis (PCA), showed distinct inputs of sterols derived from human activity (40.58%), terrigenous and plant inputs (22.59%) as well as phytoplankton and marine inputs (17.35%).
    Matched MeSH terms: Biomarkers/analysis
  15. Sethi S, Chourasia D, Parhar IS
    J Biosci, 2015 Sep;40(3):607-27.
    PMID: 26333406
    An extensive guide on practicable and significant quantitative proteomic approaches in neuroscience research is important not only because of the existing overwhelming limitations but also for gaining valuable understanding into brain function and deciphering proteomics from the workbench to the bedside. Early methodologies to understand the functioning of biological systems are now improving with high-throughput technologies, which allow analysis of various samples concurrently, or of thousand of analytes in a particular sample. Quantitative proteomic approaches include both gel-based and non-gel-based methods that can be further divided into different labelling approaches. This review will emphasize the role of existing technologies, their advantages and disadvantages, as well as their applications in neuroscience. This review will also discuss advanced approaches for targeted proteomics using isotope-coded affinity tag (ICAT) coupled with laser capture microdissection (LCM) followed by liquid chromatography tandem mass spectrometric (LC-MS/MS) analysis. This technology can further be extended to single cell proteomics in other areas of biological sciences and can be combined with other 'omics' approaches to reveal the mechanism of a cellular alterations. This approach may lead to further investigation in basic biology, disease analysis and surveillance, as well as drug discovery. Although numerous challenges still exist, we are confident that this approach will increase the understanding of pathological mechanisms involved in neuroendocrinology, neuropsychiatric and neurodegenerative disorders by delivering protein biomarker signatures for brain dysfunction.
    Matched MeSH terms: Biomarkers/analysis*
  16. Barakat SM, Siar CH
    J Appl Oral Sci, 2015 Jan-Feb;23(1):79-86.
    PMID: 25760270 DOI: 10.1590/1678-775720140245
    The identification of stem cells (SC) remains challenging. In the human oral mucosal epithelium, these cells are believed to be in the basal layer (stem cell niche), but their exact location is unclear. The aim of this study was to examine the dysplastic oral epithelium for these SC-like proteins in order to assess their diagnostic value as biomarkers complementing the histological grading of dysplasia.
    Matched MeSH terms: Biomarkers/analysis
  17. Jamaludin S, Mustaffa N, Che Hamzah NA, Syed Abdul Aziz SH, Lee YY
    BMC Gastroenterol, 2015;15:101.
    PMID: 26264957 DOI: 10.1186/s12876-015-0332-0
    Unchanged substrate in a negative rapid urease test may be reused to detect Helicobacter pylori (H. pylori). This could potentially reduce costs and wastage in low prevalence and resource-poor settings. We thus aimed to investigate the diagnostic accuracy of reused Pronto Dry and CLOtest kits, comparing this to the use of new Pronto Dry test kits and histopathological evaluation of gastric mucosal biopsies.
    Matched MeSH terms: Biomarkers/analysis
  18. Sutris JM, How V, Sumeri SA, Muhammad M, Sardi D, Mohd Mokhtar MT, et al.
    Int J Occup Environ Med, 2016 01;7(1):42-51.
    PMID: 26772597 DOI: 10.15171/ijoem.2016.705
    BACKGROUND: Agriculture is an important sector for the Malaysian economy. The use of pesticides in agriculture is crucial due to its function in keeping the crops from harmful insects. Children living near agricultural fields are at risk of pesticide poisoning.

    OBJECTIVE: To evaluate the genotoxic risk among children who exposed to pesticides and measure DNA damage due to pesticides exposure.

    METHODS: In a cross-sectional study 180 Orang Asli Mah Meri children aged between 7 and 12 years were studied. They were all living in an agricultural island in Kuala Langat, Selangor, Malaysia. The data for this study were collected via modified validated questionnaire and food frequency questionnaire, which consisted of 131 food items. 6 urinary organophosphate metabolites were used as biomarkers for pesticides exposure. For genotoxic risk or genetic damage assessment, the level of DNA damage from exfoliated buccal mucosa cells was measured using the comet assay electrophoresis method.

    RESULTS: Out of 180 respondents, 84 (46.7%) showed positive traces of organophosphate metabolites in their urine. Children with detectable urinary pesticide had a longer tail length (median 43.5; IQR 30.9 to 68.1 μm) than those with undetectable urinary pesticides (median 24.7; IQR 9.5 to 48.1 μm). There was a significant association between the extent of DNA damage and the children's age, length of residence in the area, pesticides detection, and frequency of apple consumption.

    CONCLUSION: The organophosphate genotoxicity among children is associated with the amount of exposure (detectability of urinary pesticide) and length of residence in (exposure) the study area.

    Matched MeSH terms: Biomarkers/analysis
  19. Vasanthan P, Jayaraman P, Kunasekaran W, Lawrence A, Gnanasegaran N, Govindasamy V, et al.
    Naturwissenschaften, 2016 Aug;103(7-8):62.
    PMID: 27379400 DOI: 10.1007/s00114-016-1387-7
    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.
    Matched MeSH terms: Biomarkers/analysis
  20. Fathil MF, Md Arshad MK, Ruslinda AR, Nuzaihan M N M, Gopinath SC, Adzhri R, et al.
    Anal Chim Acta, 2016 Sep 07;935:30-43.
    PMID: 27543013 DOI: 10.1016/j.aca.2016.06.012
    A real-time ability to interpret the interaction between targeted biomolecules and the surface of semiconductors (metal transducers) into readable electrical signals, without biomolecular modification involving fluorescence dyes, redox enzymes, and radioactive labels, created by label-free biosensors has been extensively researched. Field-effect transistor (FET)- and capacitor-based biosensors are among the diverse electrical charge biosensing architectures that have drawn much attention for having charge transduction; thus, enabling the early and rapid diagnosis of the appropriate cardiac biomarkers at lower concentrations. These semiconducting material-based transducers are very suitable to be integrated with portable electronic devices for future online collection, transmission, reception, analysis, and reporting. This overview elucidates and clarifies two major electrical label-free systems (FET- and capacitor-based biosensors) with cardiac troponin (cTn) biomarker-mediated charge transduction for acute myocardial infarction (AMI) diagnosis. Advances in these systems are highlighted by their progression in bridging the laboratory and industry; the foremost technologies have made the transition from benchtop to bedside and beyond.
    Matched MeSH terms: Biomarkers/analysis
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