Browse publications by year: 2019

  1. Thiagamani SMK, Krishnasamy S, Muthukumar C, Tengsuthiwat J, Nagarajan R, Siengchin S, et al.
    Int J Biol Macromol, 2019 Nov 01;140:637-646.
    PMID: 31437507 DOI: 10.1016/j.ijbiomac.2019.08.166
    This work focuses on the fabrication of hybrid bio-composites using green epoxy as the matrix material, hemp (H) and sisal (S) fibre mats as the reinforcements. The hybrid composite with sisal/hemp fibres were fabricated by cost effective hand lay-up technique, followed by hot press with different stacking sequences. Static properties of the composites such as tensile, compressive, inter-laminar shear strengths (ILSS) and hardness were examined. The physical properties such as density, void content, water absorption and thickness swelling were also analyzed. The experimental results indicate that hybrid composites exhibited minor variation in tensile strength when the stacking sequence was altered. The hybrid composite with the intercalated arrangement (HSHS) exhibited the highest tensile modulus when compared with the other hybrid counterparts. Hybrid composites (SHHS and HSSH) offered 40% higher values of compressive strength than the other layering arrangements. HHHH sample exhibited the highest ILSS value of 4.08 MPa. Typical failure characteristics of the short beam test such as inter-laminar shear cracks in the transverse direction, micro-buckling and fibre rupture were also observed.
    MeSH terms: Cannabis/chemistry*; Epoxy Resins/chemistry*; Hardness; Materials Testing/methods; Pressure; Tensile Strength; Water/chemistry; Compressive Strength; Shear Strength
  2. Choi D, Oh JI, Lee J, Park YK, Lam SS, Kwon EE
    Environ Int, 2019 11;132:105037.
    PMID: 31437646 DOI: 10.1016/j.envint.2019.105037
    In an effort to seek a new technical platform for disposal of drinking water treatment sludge (DWTS: alum sludge), pyrolysis of DWTS was mainly investigated in this study. To establish a more sustainable thermolytic platform for DWTS, this study particularly employed CO2 as reactive gas medium. Thus, this study laid great emphasis on elucidating the mechanistic roles of CO2 during the thermolysis of DWTS. A series of the TGA tests of DWTS in CO2 in reference to N2 revealed no occurrence of the heterogeneous reaction between CO2 and the sample surface of DWTS. As such, at the temperature regime before initiating the Boudouard reaction (i.e., ≥700 °C), the mass decay patterns of DWTS in N2 and CO2 were nearly identical. However, the gaseous effluents from lab-scale pyrolysis of DWTS in CO2 in reference to N2 were different. In sum, the homogeneous reactions between CO2 and volatile matters (VMs) evolved from the thermolysis of DWTS led to the enhanced generation of CO. Also, CO2 suppressed dehydrogenation of VMs. Such the genuine mechanistic roles of CO2 in the thermolysis of DWTS subsequently led to the compositional modifications of the chemical species in pyrolytic oil. Furthermore, the biochar composite was obtained as byproduct of pyrolysis of DWTS. Considering that the high content of Al2O3 and Fe-species in the biochar composite imparts a strong affinity for As(V), the practical use of the biochar composite as a sorptive material for arsenic (V) was evaluated at the fundamental levels. This work reported that adsorption of As(V) onto the biochar composite followed the pseudo-second order model and the Freundlich isotherm model.
    MeSH terms: Adsorption; Alum Compounds/economics; Alum Compounds/chemistry*; Arsenic/chemistry; Carbon Dioxide/chemistry*; Charcoal/chemistry; Sewage/chemistry*; Temperature; Water Purification
  3. Tam SW, Feng R, Lau WK, Law AC, Yeung PK, Chung SK
    J Biol Chem, 2019 08 16;294(33):12495-12506.
    PMID: 31248984 DOI: 10.1074/jbc.RA118.005155
    Endothelin-1 (ET-1) is a neuroactive peptide produced by neurons, reactive astrocytes, and endothelial cells in the brain. Elevated levels of ET-1 have been detected in the post-mortem brains of individuals with Alzheimer's disease (AD). We have previously demonstrated that overexpression of astrocytic ET-1 exacerbates memory deficits in aged mice or in APPK670/M671 mutant mice. However, the effects of ET-1 on neuronal dysfunction remain elusive. ET-1 has been reported to mediate superoxide formation in the vascular system via NADPH oxidase (NOX) and to regulate the actin cytoskeleton of cancer cell lines via the cofilin pathway. Interestingly, oxidative stress and cofilin activation were both reported to mediate one of the AD histopathologies, cofilin rod formation in neurons. This raises the possibility that ET-1 mediates neurodegeneration via oxidative stress- or cofilin activation-driven cofilin rod formation. Here, we demonstrate that exposure to 100 nm ET-1 or to a selective ET type B receptor (ETB) agonist (IRL1620) induces cofilin rod formation in dendrites of primary hippocampal neurons, accompanied by a loss of distal dendrites and a reduction in dendritic length. The 100 nm IRL1620 exposure induced superoxide formation and cofilin activation, which were abolished by pretreatment with a NOX inhibitor (5 μm VAS2870). Moreover, IRL1620-induced cofilin rod formation was partially abolished by pretreatment with a calcineurin inhibitor (100 nm FK506), which suppressed cofilin activation. In conclusion, our findings suggest a role for ETB in neurodegeneration by promoting cofilin rod formation and dendritic loss via NOX-driven superoxide formation and cofilin activation.
    MeSH terms: Alzheimer Disease/genetics; Alzheimer Disease/metabolism; Alzheimer Disease/pathology; Animals; Dendrites/metabolism*; Dendrites/pathology; Peptide Fragments/pharmacology; Endothelins/pharmacology; Oxidative Stress*; Endothelin-1/genetics; Endothelin-1/metabolism; Receptor, Endothelin B/genetics; Receptor, Endothelin B/metabolism*; Actin Depolymerizing Factors/genetics; Actin Depolymerizing Factors/metabolism*; Mice; Endothelin B Receptor Antagonists/pharmacology
  4. Ong HK, Yong CY, Tan WS, Yeap SK, Omar AR, Razak MA, et al.
    Vaccines (Basel), 2019 08 19;7(3).
    PMID: 31430965 DOI: 10.3390/vaccines7030091
    Current seasonal influenza A virus (IAV) vaccines are strain-specific and require annual reconstitution to accommodate the viral mutations. Mismatches between the vaccines and circulating strains often lead to high morbidity. Hence, development of a universal influenza A vaccine targeting all IAV strains is urgently needed. In the present study, the protective efficacy and immune responses induced by the extracellular domain of Matrix 2 protein (M2e) displayed on the virus-like particles of Macrobrachium rosenbergii nodavirus (NvC-M2ex3) were investigated in BALB/c mice. NvC-M2ex3 was demonstrated to be highly immunogenic even in the absence of adjuvants. Higher anti-M2e antibody titers corresponded well with increased survival, reduced immunopathology, and morbidity of the infected BALB/c mice. The mice immunized with NvC-M2ex3 exhibited lower H1N1 and H3N2 virus replication in the respiratory tract and the vaccine activated the production of different antiviral cytokines when they were challenged with H1N1 and H3N2. Collectively, these results suggest that NvC-M2ex3 could be a potential universal influenza A vaccine.
    MeSH terms: Adjuvants, Immunologic; Animals; Antiviral Agents; Humans; Immunization; Influenza, Human; Influenza Vaccines; Mice, Inbred BALB C; Mutation; Influenza A virus; Respiratory System; Seasons; Vaccination; Virus Replication; Cytokines; Palaemonidae; Mice; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype
  5. Hamzah N, Mohamad NA, Thiruselvam I, Hariri F, Veeramuthu V, Mazlan M, et al.
    Appl Neuropsychol Adult, 2019 08 21;28(4):416-426.
    PMID: 31431094 DOI: 10.1080/23279095.2019.1648264
    This study assessed the validity (construct validity) and reliability (internal consistency) of the Neuropsychological Assessment Battery Screening Module (S-NAB) in detecting mild cognitive deficit/alteration in multicultural, multilingual, and multiethnic mild traumatic brain injury (mTBI) population of Malaysia. S-NAB and Montreal Cognitive Assessment (MoCA) data from 114 patients with mTBI (93 males; 21 females) aged 18 to 60 years old were obtained at University Malaya Medical Center, Malaysia. The mean age was 28.17 ± 8.57 years and mean education years was 12.40 ± 2.01. Convergent validity was assessed between S-NAB domain scores and MoCA total scores by using Pearson's correlation and internal consistency was assessed using Cronbach's alpha. Acceptable internal consistency (α ≥ .70) was found for Attention, Language, and Memory domains but weak internal consistencies (α 
    MeSH terms: Adolescent; Adult; Female; Humans; Male; Middle Aged; Neuropsychological Tests; Psychometrics; Reproducibility of Results; Young Adult
  6. Yahya F, Gaffney K, Sengupta R
    Rheumatol Adv Pract, 2019;3(1):rkz012.
    PMID: 31432000 DOI: 10.1093/rap/rkz012
    Objectives: The aim was to define sub-optimal response to TNF inhibitors (TNFi), compare long-term drug survival rates and identify predictors of sub-optimal response in axial spondyloarthritis (axSpA) patients in a UK cohort.

    Methods: All axSpA patients attending two centres who commenced TNFi between 2002 and 2016 were included. Routinely recorded patient data were reviewed retrospectively. Patients with paired BASDAI at baseline, 3 and/or 6 months were included for analysis. Sub-optimal response was defined as achieving a ≥ 2-point reduction in BASDAI but not BASDAI50, post-treatment BASDAI remaining at ≥4, and in the opinion of the treating physician these patients demonstrated a meaningful clinical response.

    Results: Four hundred and ninety-nine patients were included: 82 (16.4%) patients were classified as having a sub-optimal response; 64 (78%) males, 78 (95.1%) AS and 55/67 (82.1%) HLA-B27 positive. Results are reported as the mean (s.d.). Time to diagnosis was 10 (8.6) years, age at diagnosis was 37 (11.7) years, and age at initiating index TNFi was 48 (11.1) years. Individual index TNFi were Humira (adalimumab, n = 41, 50%), Enbrel (etanercept, n = 27, 32.9%), Remicade (infliximab, n = 5, 6.1%), Simponi (golimumab, n = 3, 3.7%) and Cimzia (certolizumab pegol, n = 6, 7.3%). The rate of attrition was greater among sub-optimal responders at 2 and 5 years (P 

    MeSH terms: Certolizumab Pegol; Etanercept; Adalimumab; Infliximab; Antibodies, Monoclonal; Attitude; Humans; Male; Retrospective Studies; Tumor Necrosis Factor-alpha; Cohort Studies; HLA-B27 Antigen; Survival Rate; Odds Ratio
  7. Rahmani M, Ghafoorifard H, Afrang S, Ahmadi MT, Rahmani K, Ismail R
    IET Nanobiotechnol, 2019 Aug;13(6):584-592.
    PMID: 31432790 DOI: 10.1049/iet-nbt.2018.5288
    The response of trilayer graphene nanoribbon (TGN)-based ion-sensitive field-effect transistor (ISFET) to different pH solutions and adsorption effect on the sensing parameters are analytically studied in this research. The authors propose a TGN-based sensor to electrochemically detect pH. To this end, absorption effect on the sensing area in the form of carrier concentration, carrier velocity, and conductance variations are investigated. Also, the caused electrical response on TGN as a detection element is analytically proposed, in which significant current decrease of the sensor is observed after exposure to high pH values. In order to verify the accuracy of the model, it is compared with recent reports on pH sensors. The TGN-based pH sensor exposes higher current compared to that of carbon nanotube (CNT) counterpart for analogous ambient conditions. While, the comparative results demonstrate that the conductance of proposed model is lower than that of monolayer graphene-counterpart for equivalent pH values. The results confirm that the conductance of the sensor is decreased and Vg-min is obviously right-shifted by increasing value of pH. The authors demonstrate that although there is not the experimental evidence reported in the part of literature for TGN sensor, but the model can assist in comprehending experiments involving nanoscale pH sensors.
    MeSH terms: Adsorption; Electricity; Electrochemistry/instrumentation; Electrochemistry/methods; Electrolytes/chemistry*; Graphite/chemistry*; Hydrogen-Ion Concentration; Models, Theoretical; Sensitivity and Specificity; Biosensing Techniques/instrumentation; Biosensing Techniques/methods*; Nanotubes, Carbon/chemistry*
  8. Kasim MF, Darman AKAB, Yaakob MK, Badar N, Kamarulzaman N
    Phys Chem Chem Phys, 2019 Sep 11;21(35):19126-19146.
    PMID: 31432825 DOI: 10.1039/c9cp01664c
    In this study, nano- and microsized zinc oxide (ZnO) materials were doped with different manganese (Mn) contents (1-5 mol%) via a simple sol-gel method. The structural, morphological, optical and chemical environments of the materials were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). XRD results revealed that all synthesised materials were pure and single phased with a hexagonal wurtzite structure of ZnO. However, at a low annealing temperature, a nanorod-like shape can be obtained for all Zn(1-x)MnxO materials. In addition, EDX spectra confirmed the presence of Mn in the ZnO lattice and the atomic percentage was nearly equal to the calculated stoichiometry. UV-vis spectroscopy further revealed that materials in nano size exhibited band gap widening with an increase of the Mn content in the ZnO lattice. In contrast, micron state materials exhibited band gap narrowing with increasing Mn content up to 3% and then begin to widen when Mn > 3%. This is because the band gaps of these materials are affected by the dimensions of the crystals and the Mn content in the materials. Furthermore, XPS results revealed the existence of multiple states of Mn in all synthesised materials. By combining the information obtained from UV-vis and the XPS valence band, shifting in the valence band maximum (VBM) and conduction band minimum (CBM) was observed. Based on XPS results, the calculation of density functional theory studies revealed that the presence of Mn2+, Mn3+, and Mn4+ ions in the materials influences the band gap changes. It was also revealed that the nanosized Zn0.99Mn0.01O exhibited a higher photocatalytic activity than the other samples for degrading methylene blue (MB) dyes, owing to its smallest crystallite size.
    MeSH terms: Coloring Agents; Ions; Manganese; Methylene Blue; Microscopy, Electron, Scanning; Spectrometry, X-Ray Emission; Spectrophotometry, Ultraviolet; Temperature; Thiazines; X-Ray Diffraction; Zinc; Zinc Oxide; Nanotubes; Photoelectron Spectroscopy
  9. Bihud NV, Rasol NE, Imran S, Awang K, Ahmad FB, Mai CW, et al.
    J Nat Prod, 2019 09 27;82(9):2430-2442.
    PMID: 31433181 DOI: 10.1021/acs.jnatprod.8b01067
    Eight new bis-styryllactones, goniolanceolatins A-H (1-8), possessing a rare α,β-unsaturated δ-lactone moiety with a (6S)-configuration, were isolated from the CH2Cl2 extract of the stembark and roots of Goniothalamus lanceolatus Miq., a plant endemic to Malaysia. Absolute structures were established through extensive 1D- and 2D-NMR data analysis, in combination with electronic dichroism (ECD) data. All of the isolates were evaluated for their cytotoxicity against human lung and colorectal cancer cell lines. Compounds 2 and 4 showed cytotoxicity, with IC50 values ranging from 2.3 to 4.2 μM, and were inactive toward human noncancerous lung and colorectal cells. Compounds 1, 3, 6, 7, and 8 showed moderate to weak cytotoxicity. Docking studies of compounds 2 and 4 showed that they bind with EGFR tyrosine kinase and cyclin-dependent kinase 2 through hydrogen bonding interactions with the important amino acids, including Lys721, Met769, Asn818, Arg157, Ile10, and Glu12.
    MeSH terms: Antineoplastic Agents, Phytogenic/isolation & purification; Antineoplastic Agents, Phytogenic/pharmacology*; Antineoplastic Agents, Phytogenic/chemistry; Lactones/isolation & purification; Lactones/pharmacology*; Lactones/chemistry; Plant Extracts/pharmacology; Plant Extracts/chemistry; Goniothalamus/chemistry*
  10. Schröeder SE, Pedrana A, Scott N, Wilson D, Kuschel C, Aufegger L, et al.
    Liver Int, 2019 Oct;39(10):1818-1836.
    PMID: 31433902 DOI: 10.1111/liv.14222
    Viral hepatitis is a leading cause of morbidity and mortality worldwide, but has long been neglected by national and international policymakers. Recent modelling studies suggest that investing in the global elimination of viral hepatitis is feasible and cost-effective. In 2016, all 194 member states of the World Health Organization endorsed the goal to eliminate viral hepatitis as a public health threat by 2030, but complex systemic and social realities hamper implementation efforts. This paper presents eight case studies from a diverse range of countries that have invested in responses to viral hepatitis and adopted innovative approaches to tackle their respective epidemics. Based on an investment framework developed to build a global investment case for the elimination of viral hepatitis by 2030, national activities and key enablers are highlighted that showcase the feasibility and impact of concerted hepatitis responses across a range of settings, with different levels of available resources and infrastructural development. These case studies demonstrate the utility of taking a multipronged, public health approach to: (a) evidence-gathering and planning; (b) implementation; and (c) integration of viral hepatitis services into the Agenda for Sustainable Development. They provide models for planning, investment and implementation strategies for other countries facing similar challenges and resource constraints.
    MeSH terms: Health Resources/statistics & numerical data*; Health Services Accessibility/legislation & jurisprudence; Health Services Accessibility/statistics & numerical data*; Hepatitis B/prevention & control*; Hepatitis B/therapy; Hepatitis C/prevention & control*; Hepatitis C/therapy; Humans; Public Health/legislation & jurisprudence; Public Health/statistics & numerical data*; World Health Organization; Models, Organizational; Organizational Case Studies; Global Burden of Disease
  11. Sato S, Tojo B, Hoshi T, Minsong LIF, Kugan OK, Giloi N, et al.
    PMID: 31426380 DOI: 10.3390/ijerph16162954
    Plasmodium knowlesi (Pk) is a malaria parasite that naturally infects macaque monkeys in Southeast Asia. Pk malaria, the zoonosis transmitted from the infected monkeys to the humans by Anopheles mosquito vectors, is now a serious health problem in Malaysian Borneo. To create a strategic plan to control Pk malaria, it is important to estimate the occurrence of the disease correctly. The rise of Pk malaria has been explained as being due to ecological changes, especially deforestation. In this research, we analysed the time-series satellite images of MODIS (MODerate-resolution Imaging Spectroradiometer) of the Kudat Peninsula in Sabah and created the "Pk risk map" on which the Land-Use and Land-Cover (LULC) information was visualised. The case number of Pk malaria of a village appeared to have a correlation with the quantity of two specific LULC classes, the mosaic landscape of oil palm groves and the nearby land-use patches of dense forest, surrounding the village. Applying a Poisson multivariate regression with a generalised linear mixture model (GLMM), the occurrence of Pk malaria cases was estimated from the population and the quantified LULC distribution on the map. The obtained estimations explained the real case numbers well, when the contribution of another risk factor, possibly the occupation of the villagers, is considered. This implies that the occurrence of the Pk malaria cases of a village can be predictable from the population of the village and the LULC distribution shown around it on the map. The Pk risk map will help to assess the Pk malaria risk distributions quantitatively and to discover the hidden key factors behind the spread of this zoonosis.
    MeSH terms: Animals; Anopheles; Humans; Malaria/epidemiology*; Malaysia/epidemiology; Risk Factors; Zoonoses/epidemiology; Incidence; Plasmodium knowlesi*; Remote Sensing Technology; Forests; Mosquito Vectors
  12. Hashim MS, Obaideen AA, Jahrami HA, Radwan H, Hamad HJ, Owais AA, et al.
    Nutrients, 2019 Aug 17;11(8).
    PMID: 31426498 DOI: 10.3390/nu11081939
    Premenstrual syndrome (PMS) is a cyclical late luteal phase disorder of the menstrual cycle whereby the daily functioning of women is affected by emotional and physical symptoms substantially interfering with their quality of life. Little is known about PMS in the United Arab Emirates (UAE). This study aimed to determine the prevalence and severity of PMS among university students in Sharjah, UAE, and clarify its associations with dietary habits, lifestyle behaviors, and anthropometric factors. A cross-sectional study was conducted on female college students at the University of Sharjah, UAE. Data were collected using self-administered questionnaires and anthropometric assessments. Descriptive statistics and multiple logistic regression analyses were performed. Participants were 300 adult university students aged 18-24 years (mean age 20.07 ± 1.53 years). In total, 95% of participants reported at least one PMS symptom during their menstrual period. The prevalence of PMS was 35.3%, with mild symptoms being the most commonly reported. Multiple regression analysis showed that smoking was associated with increased risk of reporting psychological (OR 2.5, 95% CI 1.1-5.8; p < 0.05) and behavioral symptoms (OR 2.2, 95% CI 1.0-4.9; p < 0.05), while high calorie/fat/sugar/salt foods intake was associated with increased risk of reporting physical symptoms (OR 3.2, 95% CI 1.4-7.3; p < 0.05). However, fruit consumption (OR 0.34, 95% CI 0.125-0.92; p < 0.05) was associated with a decreased risk of reporting behavioral symptoms. A high prevalence of PMS was reported among university students, with smoking and high calorie/fat/sugar/salt food consumption identified as strong risk factors for PMS.
    MeSH terms: Adult; Energy Intake; Cross-Sectional Studies; Diet*; Emotions; Feeding Behavior*; Female; Humans; Life Style*; Premenstrual Syndrome/etiology*; Premenstrual Syndrome/epidemiology; Premenstrual Syndrome/prevention & control; Premenstrual Syndrome/psychology; Quality of Life; Surveys and Questionnaires; Risk Factors; Severity of Illness Index; Smoking*; Students; United Arab Emirates/epidemiology; Universities*; Prevalence; Logistic Models; Young Adult
  13. Karunarathne VK, Paul SC, Šavija B
    Materials (Basel), 2019 Aug 17;12(16).
    PMID: 31426501 DOI: 10.3390/ma12162622
    In this study, the use of nano-silica (nano-SiO2) and bentonite as mortar additives for combating reinforcement corrosion is reported. More specifically, these materials were used as additives in ordinary Portland cement (OPC)/fly ash blended mortars in different amounts. The effects of nano-silica and bentonite addition on compressive strength of mortars at different ages was tested. Accelerated corrosion testing was used to assess the corrosion resistance of reinforced mortar specimens containing different amounts of nano-silica and bentonite. It was found that the specimens containing nano-SiO2 not only had higher compressive strength, but also showed lower steel mass loss due to corrosion compared to reference specimens. However, this was accompanied by a small reduction in workability (for a constant water to binder ratio). Mortar mixtures with 4% of nano-silica were found to have optimal performance in terms of compressive strength and corrosion resistance. Control specimens (OPC/fly ash mortars without any additives) showed low early age strength and low corrosion resistance compared to specimens containing nano-SiO2 and bentonite. In addition, samples from selected mixtures were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Finally, the influence of Ca/Si ratio of the calcium silicate hydrate (C-S-H) in different specimens on the compressive strength is discussed. In general, the study showed that the addition of nano-silica (and to a lesser extent bentonite) can result in higher strength and corrosion resistance compared to control specimens. Furthermore, the addition of nano-SiO2 can be used to offset the negative effect of fly ash on early age strength development.
    MeSH terms: Bentonite; Construction Materials; Corrosion; Microscopy, Electron, Scanning; Silicon Dioxide; Spectrometry, X-Ray Emission; Steel; Water; X-Rays; Calcium Compounds; Silicates; Compressive Strength; Coal Ash
  14. Bui DT, Moayedi H, Kalantar B, Osouli A, Pradhan B, Nguyen H, et al.
    Sensors (Basel), 2019 Aug 17;19(16).
    PMID: 31426552 DOI: 10.3390/s19163590
    In this research, the novel metaheuristic algorithm Harris hawks optimization (HHO) is applied to landslide susceptibility analysis in Western Iran. To this end, the HHO is synthesized with an artificial neural network (ANN) to optimize its performance. A spatial database comprising 208 historical landslides, as well as 14 landslide conditioning factors-elevation, slope aspect, plan curvature, profile curvature, soil type, lithology, distance to the river, distance to the road, distance to the fault, land cover, slope degree, stream power index (SPI), topographic wetness index (TWI), and rainfall-is prepared to develop the ANN and HHO-ANN predictive tools. Mean square error and mean absolute error criteria are defined to measure the performance error of the models, and area under the receiving operating characteristic curve (AUROC) is used to evaluate the accuracy of the generated susceptibility maps. The findings showed that the HHO algorithm effectively improved the performance of ANN in both recognizing (AUROCANN = 0.731 and AUROCHHO-ANN = 0.777) and predicting (AUROCANN = 0.720 and AUROCHHO-ANN = 0.773) the landslide pattern.
  15. Shahruzaman SH, Mustafa MF, Ramli S, Maniam S, Fakurazi S, Maniam S
    BMC Complement Altern Med, 2019 Aug 19;19(1):220.
    PMID: 31426778 DOI: 10.1186/s12906-019-2628-z
    BACKGROUND: Baeckea frutescens (B. frutescens) of the family Myrtaceae is a plant that has been used in traditional medicine. It is known to have antibacterial, antipyretic and cytoprotective properties. The objective of this study is to explore the mechanism of B. frutescens leaves extracts in eliminating breast cancer cells.

    METHOD: B. frutescens leaves extracts were prepared using Soxhlet apparatus with solvents of different polarity. The selective cytotoxicity of these extracts at various concentrations (20 to 160 μg/ml) were tested using cell viability assay after 24, 48 and 72 h of treatment. The IC50 value in human breast cancer (MCF-7 and MDA-MB-231) and mammary breast (MCF10A) cell lines were determined. Apoptotic study using AO/PI double staining was performed using fluorescent microscope. The glucose uptake was measured using 2-NBDG, a fluorescent glucose analogue. The phytochemical screening was performed for alkaloids, flavonoids, tannins, triterpenoids, and phenols.

    RESULTS: B. frutescens leaves extracts showed IC50 value ranging from 10 -127μg/ml in MCF-7 cells after 72 h of treatment. Hexane extract had the lowest IC50 value (10μg/ml), indicating its potent selective cytotoxic activity. Morphology of MCF-7 cells after treatment with B. frutescens extracts exhibited evidence of apoptosis that included membrane blebbing and chromatin condensation. In the glucose uptake assay, B. frutescens extracts suppressed glucose uptake in cancer cells as early as 24 h upon treatment. The inhibition was significantly lower compared to the positive control WZB117 at their respective IC50 value after 72 h incubation. It was also shown that the glucose inhibition is selective towards cancer cells compared to normal cells. The phytochemical analysis of the extract using hexane as the solvent in particular gave similar quantities of tannin, triterpenoids, flavonoid and phenols. Presumably, these metabolites have a synergistic effect in the in vitro testing, producing the potent IC50 value and subsequently cell death.

    CONCLUSION: This study reports the potent selective cytotoxic effect of B. frutescens leaves hexane extract against MCF-7 cancer cells. B. frutescens extracts selectively suppressed cancer cells glucose uptake and subsequently induced cancer cell death. These findings suggest a new role of B. frutescens in cancer cell metabolism.

    MeSH terms: Antineoplastic Agents, Phytogenic/pharmacology*; Antineoplastic Agents, Phytogenic/chemistry; Breast Neoplasms/metabolism*; Female; Glucose/analysis; Glucose/metabolism*; Humans; Plant Extracts/pharmacology*; Plant Extracts/chemistry; Apoptosis/drug effects; Plant Leaves/chemistry; Myrtaceae/chemistry*; Cell Line, Tumor; MCF-7 Cells
  16. Glazier PS, Mehdizadeh S
    J Biomech, 2019 Sep 20;94:1-4.
    PMID: 31427095 DOI: 10.1016/j.jbiomech.2019.07.044
    The development of methods that can identify athlete-specific optimum sports techniques-arguably the holy grail of sports biomechanics-is one of the greatest challenges for researchers in the field. This 'perspectives article' critically examines, from a dynamical systems theoretical standpoint, the claim that athlete-specific optimum sports techniques can be identified through biomechanical optimisation modelling. To identify athlete-specific optimum sports techniques, dynamical systems theory suggests that a representative set of organismic constraints, along with their non-linear characteristics, needs to be identified and incorporated into the mathematical model of the athlete. However, whether the athlete will be able to adopt, and reliably reproduce, his/her predicted optimum technique will largely be dependent on his/her intrinsic dynamics. If the attractor valley corresponding to the existing technique is deep, or if the attractor valleys corresponding to the existing technique and the predicted optimum technique are in different topographical regions of the dynamic landscape, technical modifications may be challenging or impossible to reliably implement even after extended practice. The attractor layout defining the intrinsic dynamics of the athlete, therefore, needs to be determined to establish the likelihood of the predicted optimum technique being reliably attainable by the athlete. Given the limited set of organismic constraints typically used in mathematical models of athletes, combined with the methodological challenges associated with mapping the attractor layout of an athlete, it seems unlikely that athlete-specific optimum sports techniques will be identifiable through biomechanical optimisation modelling for the majority of sports skills in the near future.
    MeSH terms: Biomechanical Phenomena*; Biophysics; Humans; Models, Biological*; Sports/physiology*; Athletes*; Patient-Specific Modeling*
  17. Ismail NA, Abu Bakar SN, Abdullah N, Shafie MS, Mohd Nor F
    Malays J Pathol, 2019 Aug;41(2):83-89.
    PMID: 31427544
    INTRODUCTION: Stature estimation is population dependent, and population-specific regression equations should be generated for accurate anthropological assessments. Nevertheless, stature estimation data was inaccessible and limited in some of the South-East Asian countries. The systematic review was conducted to analyse the regression equations of stature estimations developed in South-East Asian region.

    MATERIALS AND METHODS: A systematic literature search was performed through SCOPUS database and Google Scholar from January till March 2018. All published articles which developed stature estimation from different types of bone, methods and type of statures (i.e. living stature, forensic stature and cadaveric stature) were included in this study. Risks of biases were also assessed. Population studies with no regression equations were excluded from the study.

    RESULTS: Seven studies that met the inclusion criteria were identified. In the South-East Asia region, regression equations for stature estimation were developed in Thailand and Malaysia. In these studies, bone measurements were done either by radiography, direct bone measurement, or palpation on body surface for anatomical bony prominence. All of these studies used various parts of bones for stature estimation.

    CONCLUSION: The most widely used regression equations for stature estimation in South-East Asian population were from the Thailand population. Further research is recommended to develop regression equations for other South-East Asian countries.

    MeSH terms: Body Height; Humans; Malaysia; Palpation; Radiography; Research; Thailand
  18. Cheah PL, Li J, Looi LM, Koh CC, Lau TP, Chang SW, et al.
    Malays J Pathol, 2019 Aug;41(2):91-100.
    PMID: 31427545
    Since 2014, the National Comprehensive Cancer Network (NCCN) has recommended that colorectal carcinoma (CRC) be universally tested for high microsatellite instability (MSI-H) which is present in 15% of such cancers. Fidelity of resultant microsatellites during DNA replication is contingent upon an intact mismatch repair (MMR) system and lack of fidelity can result in tumourigenesis. Prior to commencing routine screening for MSI-H, we assessed two commonly used methods, immunohistochemical (IHC) determination of loss of MMR gene products viz MLH1, MSH2, MSH6 and PMS2 against PCR amplification and subsequent fragment analysis of microsatellite markers, BAT25, BAT26, D2S123, D5S346 and D17S250 (Bethesda markers) in 73 unselected primary CRC. 15.1% (11/73) were categorized as MSI-H while deficient MMR (dMMR) was detected in 16.4% (12/73). Of the dMMR, 66.7% (8/12) were classified MSI-H, while 33.3% (4/12) were microsatellite stable/low microsatellite instability (MSS/MSI-L). Of the proficient MMR (pMMR), 95.1% (58/61) were MSS/MSI-L and 4.9% (3/61) were MSI-H. The κ value of 0.639 (standard error =0.125; p = 0.000) indicated substantial agreement between detection of loss of DNA mismatch repair using immunohistochemistry and the detection of downstream microsatellite instability using PCR. After consideration of advantages and shortcomings of both methods, it is our opinion that the choice of preferred technique for MSI analysis would depend on the type of laboratory carrying out the testing.
    MeSH terms: Attitude; DNA Replication; Immunohistochemistry; Colorectal Neoplasms; Polymerase Chain Reaction; Microsatellite Repeats; Microsatellite Instability; DNA Mismatch Repair; Carcinogenesis; MutL Protein Homolog 1
  19. Phang KC, Hussin NH, Abdul Rahman F, Tizen NMS, Mansoor A, Masir N
    Malays J Pathol, 2019 Aug;41(2):101-124.
    PMID: 31427546
    INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive type of non-Hodgkin lymphoma with variable clinical outcomes. The immunogenotypic features of this heterogeneous disease in Malaysia were not well characterized.

    MATERIALS & METHODS: In total 141 local series of DLBCL cases from UKM Medical Centre were retrospectively studied.

    RESULTS: Of these cases, we classified our patients into two subtypes: 32.7% (37/113) GCB and non-GCB 67.3% (76/113) by Hans algorithm and the results showed strong agreement with the results by Choi algorithm (κ = 0.828, P<0.001). Survival analysis indicated significant difference in between GCB and non-GCB subtypes (P=0.01), elevated serum LDH (P=0.016), age more than 60-year-old (P=0.021) and the presence of B symptoms (P=0.04). We observed 12% DLBCL cases were CD5 positive and 81.8% of them died of the disease (P=0.076). Analysis on the dual expression of MYC/BCL2 revealed that there is no significant difference in DE and non-DE groups (P=0.916). FISH study reported there were 9.22% (13/141) rearranged cases observed in our population at which highest frequency of BCL6 gene rearrangement (76.9%), followed by MYC (15.4%) and BCL2 (7.7%); no BCL10 and MALT-1 gene rearrangement found regardless of using TMAs or whole tissue samples. More cases of MYC protein overexpression observed compared to MYC translocation.

    CONCLUSION: Relatively lower frequency of GCB tumours and low gene rearrangement rates were observed in Malaysian population. A national study is therefore warranted to know better the immunogenotypic characteristics of DLBCL in Malaysia and their implications on the survival.

    MeSH terms: Algorithms; Humans; Lymphoma, Non-Hodgkin; Malaysia; Retrospective Studies; Translocation, Genetic; Gene Rearrangement; Survival Analysis; Lymphoma, Large B-Cell, Diffuse
  20. Teoh PY, Tan GC, Mahsin H, Wong YP
    Malays J Pathol, 2019 Aug;41(2):125-132.
    PMID: 31427547
    INTRODUCTION: Androgen receptor (AR) is the most frequently expressed biomarker in all subtypes of breast carcinoma. Triple negative breast carcinoma (TNBC) is breast carcinoma that lacks oestrogen and progesterone receptors immunoexpression as well as absence of HER2/neu gene amplification. This makes targeted therapy not feasible in this cancer and hence has poorer prognosis. Detecting AR expression could be another milestone in the management of TNBC, as AR is a prognostic, predictive marker and potential index for targeted treatment. This study aimed to assess expression of AR in TNBC by immunohistochemistry and its association with clinicopathological parameters.

    METHODS: We analysed the expression of AR in 97 TNBC cases from Penang General Hospital for a period of 3 years (2014 to 2017). Androgen receptor immunoreactivity was considered positive if ≥ 1% of tumour cells nuclei were stained irrespective of staining intensity.

    RESULTS: The prevalence of AR expression in TNBC was 31% (30/97), with the proportion of AR-positive tumour cells ranged from 1% to 90%. These include 23 invasive carcinomas, no special type (NST) and 7 other invasive carcinoma subtypes (papillary, lobular, clear cell and medullary carcinomas). Sixty-seven cases (69%) that showed AR immunonegativity were invasive carcinomas, NST (n=60), clear cell carcinoma (n=1) and metaplastic carcinoma (n=6). Androgen receptor immunoexpression was inversely correlated with tumour grade (p=0.016), but not the tumour stage, tumour size and nodal status.

    CONCLUSION: AR is expressed in about one-third of TNBC and loss of AR immunoexpression does not predict adverse clinical outcomes. Larger cohorts for better characterisation of the role of AR immunoexpression in TNBC are warranted.

    MeSH terms: Carcinoma; Estrogens; Gene Amplification; Hospitals, General; Humans; Immunohistochemistry; Prognosis; Receptors, Androgen; Receptors, Progesterone; Staining and Labeling; Biomarkers; Prevalence; Carcinoma, Medullary; Triple Negative Breast Neoplasms
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