Browse publications by year: 2018

  1. Kumar K, Arshad SS, Selvarajah GT, Abu J, Toung OP, Abba Y, et al.
    Trop Anim Health Prod, 2018 Apr;50(4):741-752.
    PMID: 29243139 DOI: 10.1007/s11250-017-1490-6
    Japanese encephalitis (JE) is vector-borne zoonotic disease which causes encephalitis in humans and horses. Clinical signs for Japanese encephalitis virus (JEV) infection are not clearly evident in the majority of affected animals. In Malaysia, information on the prevalence of JEV infection has not been established. Thus, a cross-sectional study was conducted during two periods, December 2015 to January 2016 and March to August in 2016, to determine the prevalence and risk factors in JEV infections among animals and birds in Peninsular Malaysia. Serum samples were harvested from the 416 samples which were collected from the dogs, cats, water birds, village chicken, jungle fowls, long-tailed macaques, domestic pigs, and cattle in the states of Selangor, Perak, Perlis, Kelantan, and Pahang. The serum samples were screened for JEV antibodies by commercial IgG ELISA kits. A questionnaire was also distributed to obtain information on the animals, birds, and the environmental factors of sampling areas. The results showed that dogs had the highest seropositive rate of 80% (95% CI: ± 11.69) followed by pigs at 44.4% (95% CI: ± 1.715), cattle at 32.2% (95% CI: ± 1.058), birds at 28.9% (95% CI: ± 5.757), cats at 15.6% (95% CI: ± 7.38), and monkeys at 14.3% (95% CI: ± 1.882). The study also showed that JEV seropositivity was high in young animals and in areas where mosquito vectors and migrating birds were prevalent.
    MeSH terms: Animals; Haplorhini; Antibodies, Viral/blood*; Birds; Cats; Cattle; Cross-Sectional Studies; Dogs; Encephalitis Virus, Japanese/isolation & purification*; Encephalitis, Japanese/epidemiology; Encephalitis, Japanese/veterinary*; Enzyme-Linked Immunosorbent Assay/veterinary; Humans; Malaysia/epidemiology; Risk Factors; Swine; Prevalence; Sus scrofa; Pets/virology*; Livestock/virology*
  2. Ayadurai S, Sunderland VB, Tee LBG, Hattingh HL
    Curr Diabetes Rev, 2018;14(6):565-575.
    PMID: 29243582 DOI: 10.2174/1573399814666171215115239
    BACKGROUND: Studies on a structured method used by pharmacists to provide comprehensive, evidence-based diabetes care are lacking. The aim of this study was to prioritise, rank and construct validate indicators categorised as seven treatment factors utilised in the management of type 2 diabetes namely: Cholesterol, blood pressure and glycaemia control; medication and lifestyle management; cardiovascular risk management and patient education using the Delphi process.

    METHODS: A Delphi questionnaire consisted of 29 Part 1 and nine Part 2 indicators which were incorporated into a tool called Simpler™. The indicators were mainly sourced from American, Australian and Malaysian diabetes management guidelines. Diabetes experts were asked to rank indicators in the order of importance in Part 1. In Part 2, indicators had to be chosen for inclusion into Simpler™ using a fivepoint Likert scale. The consensus level was pre-set at 60%.

    RESULTS: A three round Delphi process was used to validate all 38 indicators by 12 experts from Australia and Malaysia: five pharmacists, four doctors, two endocrinologists and a diabetes nurse. Consensus was reached for 93.1% (27/29) of the Part 1 indicators and all nine Part 2 indicators (100%). Five out of nine indicators in Part 2 questionnaire obtained consensus disagreement for inclusion into the Simpler ™ tool.

    CONCLUSION: The Simpler™ tool is the first structured diabetes multifactorial tool to address all seven evidence-based factors. The tool was refined and validated by multi-disciplinary health professionals from Australia and Malaysia. Pharmacists can use the Simpler™ tool to facilitate evidence-based comprehensive individualised care among type 2 diabetes patients.

    MeSH terms: Australia; Delphi Technique; Diabetes Mellitus, Type 2/therapy*; Humans; Malaysia; Pharmacists; Surveys and Questionnaires*; Evidence-Based Medicine/standards*; Consensus*
  3. Ordóñez-Mena JM, Walter V, Schöttker B, Jenab M, O'Doherty MG, Kee F, et al.
    Ann Oncol, 2018 Feb 01;29(2):472-483.
    PMID: 29244072 DOI: 10.1093/annonc/mdx761
    BACKGROUND: Smoking has been associated with colorectal cancer (CRC) incidence and mortality in previous studies and might also be associated with prognosis after CRC diagnosis. However, current evidence on smoking in association with CRC prognosis is limited.

    PATIENTS AND METHODS: For this individual patient data meta-analysis, sociodemographic and smoking behavior information of 12 414 incident CRC patients (median age at diagnosis: 64.3 years), recruited within 14 prospective cohort studies among previously cancer-free adults, was collected at baseline and harmonized across studies. Vital status and causes of death were collected for a mean follow-up time of 5.1 years following cancer diagnosis. Associations of smoking behavior with overall and CRC-specific survival were evaluated using Cox regression and standard meta-analysis methodology.

    RESULTS: A total of 5229 participants died, 3194 from CRC. Cox regression revealed significant associations between former [hazard ratio (HR) = 1.12; 95 % confidence interval (CI) = 1.04-1.20] and current smoking (HR = 1.29; 95% CI = 1.04-1.60) and poorer overall survival compared with never smoking. Compared with current smoking, smoking cessation was associated with improved overall (HR<10 years = 0.78; 95% CI = 0.69-0.88; HR≥10 years = 0.78; 95% CI = 0.63-0.97) and CRC-specific survival (HR≥10 years = 0.76; 95% CI = 0.67-0.85).

    CONCLUSION: In this large meta-analysis including primary data of incident CRC patients from 14 prospective cohort studies on the association between smoking and CRC prognosis, former and current smoking were associated with poorer CRC prognosis compared with never smoking. Smoking cessation was associated with improved survival when compared with current smokers. Future studies should further quantify the benefits of nonsmoking, both for cancer prevention and for improving survival among CRC patients, in particular also in terms of treatment response.

    MeSH terms: Aged; Female; Humans; Male; Middle Aged; Prognosis; Smoking/adverse effects*; Colorectal Neoplasms/mortality*; Smoking Cessation
  4. Nam WL, Phang XY, Su MH, Liew RK, Ma NL, Rosli MHNB, et al.
    Sci Total Environ, 2018 May 15;624:9-16.
    PMID: 29245037 DOI: 10.1016/j.scitotenv.2017.12.108
    Microwave vacuum pyrolysis of palm kernel shell (PKS) was performed to produce biochar, which was then tested as bio-fertilizer in growing Oyster mushroom (Pleurotus ostreatus). The pyrolysis approach produced biochar containing a highly porous structure with a high BET surface area of up to 270m2/g and low moisture content (≤10wt%), exhibiting desirable adsorption properties to be used as bio-fertilizer since it can act as a housing that provides many sites on which living microorganisms (mycelium or plant-growth promoting bacteria) and organic nutrients can be attached or adsorbed onto. This could in turn stimulate plant growth by increasing the availability and supply of nutrients to the targeted host plant. The results from growing Oyster mushroom using the biochar recorded an impressive growth rate and a monthly production of up to about 550g of mushroom. A shorter time for mycelium growth on one whole baglog (21days) and the highest yield of Oyster mushroom (550g) were obtained from cultivation medium added with 20g of biochar. Our results demonstrate that the biochar-based bio-fertilizer produced from microwave vacuum pyrolysis of PKS shows exceptional promise as growth promoting material for mushroom cultivation.
    MeSH terms: Adsorption; Agaricus; Bacteria; Charcoal; Fertilizers; Housing; Microwaves; Vacuum; Pleurotus; Mycelium; Plant Development
  5. Ramasenderan N, Shahir H, Omar SZ
    Int J Surg Case Rep, 2018;42:116-120.
    PMID: 29245095 DOI: 10.1016/j.ijscr.2017.11.066
    INTRODUCTION: Cutaneous appendageal tumor can differentiate towards or arise from either pilosebaceous apparatus or the eccrine sweat glands. Appendageal tumors are relatively rare, their clinical appearance is non-specific, and the vast majority are not diagnosed until after excision. Eccrine porocarcinoma (EP), also known as malignant eccrine poroma is a rare adnexal tumor arising from the intraepithelial ductal parts of the sweat gland.

    CASE PRESENTATION: We presented a 65-year-old, Asian, female with medical co-morbids, who came with both a facial squamous cell carcinoma and a long-standing lesion over her left forearm. Histopathological finding of the left forearm demonstrated eccrine porocarcinoma.

    CONCLUSION: Mohs micrographic surgery is the mainstay treatment of cutaneous carcinoma. It is important to rule out associated syndromes in patient who present with multiple cutaneous appendageal tumors.

  6. Ng CKY, Lam JCW, Zhang XH, Gu HX, Li TH, Ye MB, et al.
    Environ Pollut, 2018 Mar;234:735-742.
    PMID: 29245147 DOI: 10.1016/j.envpol.2017.11.100
    Sea turtles are globally endangered and face daily anthropogenic threats, including pollution. However, there is a lack of ecotoxicological information on sea turtles, especially in the Asia-Pacific region. This study aims to determine pollutant levels of foraging green turtles (Chelonia mydas) in South China, including Hong Kong, Guangdong and Taiwan, as a basis for their conservation. Scute, liver and muscle tissues of stranded green turtles were analysed for levels of 17 trace elements and methylmercury (MeHg) (n = 86 for scute and n = 14 for liver) and polybrominated diphenyl ethers (PBDEs) (n = 11 for muscle and n = 13 for liver). Ten-fold higher levels of Pb, Ba, V and Tl and 40-fold greater Cd levels were measured in green turtle livers in South China relative to other studies conducted over 10 years ago. Measured PBDE levels were also 27-fold and 50-fold greater than those reported in Australia and Japan. These results warrant further investigation of potential toxicological risks to green turtles in South China and their source rookeries in Malaysia, Micronesia, Indonesia, Marshall Islands, Japan and Taiwan. Research should target monitoring pollutant levels in sea turtles within the West Pacific/Southeast Asia regional management unit spanning East Asia to Southeast Asia to fill in knowledge gaps, in particular in areas such as Thailand, Vietnam, Indonesia, Malaysia and the Philippines where less or no data is available and where foraging grounds of sea turtles have been identified.
    MeSH terms: Animals; Asia, Southeastern; Australia; Barium/analysis; Cadmium/analysis; China; Far East; Lead/analysis; Liver/chemistry*; Methylmercury Compounds/analysis*; Muscles/chemistry*; Thallium/analysis; Trace Elements/analysis*; Turtles/physiology*; Vanadium/analysis; Halogenated Diphenyl Ethers/analysis*
  7. Md Zin SR, Mohamed Z, Alshawsh MA, Wong WF, Kassim NM
    Exp Biol Med (Maywood), 2018 Feb;243(4):375-385.
    PMID: 29237294 DOI: 10.1177/1535370217748574
    Anastatica hierochuntica L. ( A. hierochuntica), a folk medicinal plant, was evaluated for mutagenic potential via in vitro and in vivo assays. The in vitro assay was conducted according to modified Ames test, while the in vivo study was performed according to Organisation for Economic Co-operation and Development guideline for mammalian erythrocyte micronucleus assay. Four groups ( n= 5 males and 5 females per group) Sprague Dawley rats were randomly chosen as the negative control, positive control (received a single intramuscular injection of cyclophosphamide 50 mg/kg), 1000 and, 2000 mg/kg A. hierochuntica aqueous extracts. All groups except the positive control were treated orally for three days. Findings of the in vitro assay showed mutagenic potential of AHAE at 0.04 and 0.2 mg/ml. However, no mutagenic effect was demonstrated in the in vivo study up to 2000 mg/kg. No significant reduction in the polychromatic and normochromatic erythrocytes ratio was noted in any of the groups. Meanwhile, high micronucleated polychromatic erythrocytes frequency was seen in cyclophosphamide-treated group only. These findings could perhaps be due to insufficient dosage of A. hierochuntica aqueous extracts to cause genetic damage on the bone marrow target cells. Further acute and chronic in vivo toxicity studies may be required to draw pertinent conclusion on the safety aspect of A. hierochuntica aqueous extracts consumption. Impact statement In this paper, we report on the mutagenicity evaluation of Anastatica hierochuntica aqueous extract. This is a significant research in view of the popularity of this herb consumption by the people across the globe despite of limited scientific evidence on its toxicity potential. This study is intended to encourage more extensive related research in order to provide sufficient evidence and guidance for determining its safe dosage.
    MeSH terms: Administration, Oral; Animals; Escherichia coli/drug effects; Female; Injections, Intramuscular; Male; Mutagens/administration & dosage; Mutagens/isolation & purification; Mutagens/pharmacology*; Mutation; Plant Extracts/administration & dosage; Plant Extracts/isolation & purification; Plant Extracts/pharmacology*; Salmonella typhi/drug effects; Rats, Sprague-Dawley; Brassicaceae/chemistry*; Mutation Rate
  8. Jamadon NK, Busairi N, Syahir A
    Protein Pept Lett, 2018;25(1):90-95.
    PMID: 29237368 DOI: 10.2174/0929866525666171214111503
    BACKGROUND: Mercury (II) ion, Hg2+ is among the most common pollutants with the ability to affect the environment. The implications of their elevation in the environment are mainly due to the industrialization and urbanization process. Current methods of Hg2+ detection primarily depend on sophisticated and expensive instruments. Hence, an alternative and practical way of detecting Hg2+ ions is needed to go beyond these limitations. Here, we report a detection method that was developed using an inhibitive enzymatic reaction that can be monitored through a smartphone. Horseradish peroxidase (HRP) converted 4-aminoantipyrene (4-AAP) into a red colored product which visible with naked eye. A colorless product, on the other hand, was produced indicating the presence of Hg2+ that inhibit the reaction.

    OBJECTIVES: The aim of this study is to develop a colorimetric sensor to detect Hg2+ in water sources using HRP inhibitive assay. The system can be incorporated with a mobile app to make it practical for a prompt in-situ analysis.

    METHODS: HRP enzyme was pre-incubated with different concentration of Hg2+ at 37°C for 1 hour prior to the addition of chromogen. The mix of PBS buffer, 4-AAP and phenol which act as a chromogen was then added to the HRP enzyme and was incubated for 20 minutes. Alcohol was added to stop the enzymatic reaction, and the change of colour were observed and analyse using UV-Vis spectrophotometer at 520 nm wavelength. The results were then analysed using GraphPad PRISM 4 for a non-linear regression analysis, and using Mathematica (Wolfram) 10.0 software for a hierarchical cluster analysis. The samples from spectroscopy measurement were directly used for dynamic light scattering (DLS) evaluation to evaluate the changes in HRP size due to Hg2+ malfunctionation. Finally, molecular dynamic simulations comparing normal and malfunctioned HRP were carried out to investigate structural changes of the HRP using YASARA software.

    RESULTS: Naked eye detection and data from UV-Vis spectroscopy showed good selectivity of Hg2+ over other metal ions as a distinctive color of Hg2+ is observed at 0.5 ppm with the IC50 of 0.290 ppm. The mechanism of Hg2+ inhibition towards HRP was further validated using a dynamic light scattering (DLS) and molecular dynamics (MD) simulation to ensure that there is a conformational change in HRP size due to the presence of Hg2+ ions. The naked eye detection can be quantitatively determined using a smartphone app namely ColorAssist, suggesting that the detection signal does not require expensive instruments to be quantified.

    CONCLUSION: A naked-eye colorimetric sensor for mercury ions detection was developed. The colour change due to the presence of Hg2+ can be easily distinguished using an app via a smartphone. Thus, without resorting to any expensive instruments that are mostly laboratory bound, Hg2+ can be easily detected at IC50 value of 0.29 ppm. This is a promising alternative and practical method to detect Hg2+ in the environment.

    MeSH terms: Dynamic Light Scattering; Smartphone*; Biological Assay/methods*; Calibration; Cations, Divalent/analysis; Colorimetry; Coloring Agents/chemistry; Horseradish Peroxidase/chemistry*; Light; Mercury/analysis*; Oxidation-Reduction; Particle Size; Spectrophotometry, Ultraviolet; Water Pollutants, Chemical/analysis*; Molecular Dynamics Simulation; Limit of Detection
  9. Syahir A, Kajikawa K, Mihara H
    Protein Pept Lett, 2018;25(1):34-41.
    PMID: 29237369 DOI: 10.2174/0929866525666171214111957
    BACKGROUND: Direct bio-monitoring essentially involves optical means since photon has insignificant effects over biomolecules. Over the years, laser induced surface Plasmon resonance method with various modifications as well as versatile localized Plasmon excited by incoherent light have facilitated in recording many nanobiological activities. Yet, monitoring interactions of small molecules including drugs requires signal amplification and improvement on signal-to-noise ratio.

    OBJECTIVES: This paper focused on how the refractive index based nanobio-sensoring gold platform can produce more efficient, adaptable and more practical detection techniques to observe molecular interactions at high degree of sensitivity. It discusses surface chemistry approach, optimisation of the refractive index of gold platform and manipulation of gold geometry augmenting signal quality.

    METHODS: In a normal-incidence reflectivity, r0 can be calculated using the Fresnel equation. Particularly at λ = 470 nm the ratio of r / r0 showed significant amplitude reduction mainly stemmed from the imaginary part of the Au refractive index. Hence, the fraction of reduction, Δr = 1 - r / r0. Experimentally, in a common reference frame reflectivity of a bare gold surface, R0 is compared with the reflectivity of gold surface in the presence of biolayer, R. The reduction rate (%) of reflectivity, ΔR = 1 - R / R0 is denoted as the AR signal. The method therefore enables quantitative measurement of the surface-bound protein by converting ΔR to the thickness, d, and subsequently the protein mass. We discussed four strategies to improve the AR signal by changing the effective refractive index of the biosensing platform. They are; a) Thickness optimisation of Au thin layer, b) Au / Ag bimetallic layer, c) composing alloy or Au composite, and d) Au thinlayer with nano or micro holes.

    RESULTS: As the result we successfully 'move' the refractive index, ε of the AR platform (gold only) to ε = -0.948 + 3.455i, a higher sensitivity platform. This was done by composing Au-Ag2O composite with ratio = 1:1. The results were compared to the potential sensitivity improvement of the AR substrate using other that could be done by further tailoring the ε advanced method.

    CONCLUSION: We suggested four strategies in order to realize this purpose. It is apparent that sensitivity has been improved through Au/Ag bimetallic layer or Au-Ag2O composite thin layer, This study is an important step towards fabrication of sensitive surface for detection of biomolecular interactions.

    MeSH terms: Gold/chemistry*; Light; Oxides/chemistry; Proteins/analysis*; Refractometry/methods*; Surface Properties; Biosensing Techniques; Silver Compounds/chemistry; Surface Plasmon Resonance/methods*; Nanostructures/chemistry*; Limit of Detection
  10. Loong SK, Che-Mat-Seri NA, Abdulrazak O, Douadi B, Ahmad-Nasrah SN, Johari J, et al.
    J Vet Med Sci, 2018 Jan 27;80(1):77-84.
    PMID: 29237995 DOI: 10.1292/jvms.17-0218
    Rodents have historically been associated with zoonotic pandemics that claimed the lives of large human populations. Appropriate pathogen surveillance initiatives could contribute to early detection of zoonotic infections to prevent future outbreaks. Bordetella species are bacteria known to cause mild to severe respiratory disease in mammals and, some have been described to infect, colonize and spread in rodents. There is a lack of information on the population diversity of bordetellae among Malaysian wild rodents. Here, bordetellae recovered from lung tissues of wild rats were genotypically characterized using 16S rDNA sequencing, MLST and nrdA typing. A novel B. bronchiseptica ST82, closely related to other human-derived isolates, was discovered in three wild rats (n=3) from Terengganu (5.3333° N, 103.1500° E). B. pseudohinzii, a recently identified laboratory mice inhabitant, was also recovered from one rat (n=1). Both bordetellae displayed identical antimicrobial resistance profiles, indicating the close phylogenetic association between them. Genotyping using the 765-bp nrdA locus was shown to be compatible with the MLST-based phylogeny, with the added advantage of being able to genotype non-classical bordetellae. The recovery of B. pseudohinzii from wild rat implied that this bordetellae has a wider host range than previously thought. The findings from this study suggest that bordetellae surveillance among wild rats in Malaysia has to be continued and expanded to other states to ensure early identification of species capable of causing public health disorder.
    MeSH terms: Animals; Bordetella/classification*; Bordetella/genetics; Bordetella/isolation & purification*; Bordetella Infections/microbiology; Bordetella Infections/epidemiology; Bordetella Infections/veterinary*; Genotype; Lung/microbiology; Malaysia/epidemiology; Phylogeny; Bordetella bronchiseptica/genetics; Bordetella bronchiseptica/isolation & purification; Sequence Analysis, DNA; Drug Resistance, Bacterial; Rats
  11. Fagge II, Khalid K, Noh MAM, Yusof NSM, Zain SM, Khan MN
    J Oleo Sci, 2018 Jan 01;67(1):55-66.
    PMID: 29238023 DOI: 10.5650/jos.ess17033
    Behaviors of cationic and nonionic mixed micelles in the form of hexadecyltrimethylammonium bromide (HDABr) and hexadecyltrimethylammonium bromide-Polyethylene glycol hexadecyl ether (C16E20), in the presence of inert salts (NaBr and 3,5-dichlorosodium benzoate), by the use of reaction probe between Pp and ionized PhSH (Pp = piperidine and PhSH = phenyl salicylate), has been reported in this work. The values of RXBr (RXBr denotes ion exchange constants obtained in the presence of micelles of different structural features) or KXBr (KXBr denotes ion exchange constants obtained in the presence of micelles of the same structural features) for 3,5-Cl2C6H3CO2- were almost the same at three different [HDABr]T (0.006, 0.010 and 0.015 M). The average value of RXBr or KXBr determined, in the presence of pure HDABr micelles, using semi empirical kinetic (SEK) method appeared to be almost 2½-fold larger (RXBr or KXBr = 198) than that in the presence of mixed HDABr-C16E20 micelles (RXBr or KXBr = 78). Rheological measurements indicated the existence of wormlike/twisted micelles and vesicle at 0.015 M pure HDABr, various [3,5-Cl2C6H3CO2Na], and 25 and 35℃ whereas there were evidence of only spherical micelles in the presence of mixed HDABr-C16E20 ([HDABr]T = 0.015 M and [C16E20]T = 0.006 M) at both temperatures.
    MeSH terms: Quaternary Ammonium Compounds/chemistry; Bromides/chemistry*; Catalysis; Cetomacrogol/chemistry; Chlorobenzoates/chemistry*; Kinetics; Micelles*; Piperidines/chemistry*; Rheology; Salicylates/chemistry*; Sodium Compounds/chemistry*
  12. Alshishani A, Salhimi SM, Saad B
    PMID: 29241085 DOI: 10.1016/j.jchromb.2017.12.013
    A new salting-out assisted liquid-liquid extraction (SALLE) sample preparation method for the determination of the polar anti-diabetic biguanide drugs (metformin, buformin and phenformin) in blood plasma, urine and lake water samples were developed. The SALLE was performed by mixing samples (plasma (0.2mL), urine or lake water (1.0mL)) with acetonitrile (0.4mL for plasma, 0.5mL for urine or lake water), sodium hydroxide powder was then added for the phase separation. The effects of type of salting-out reagent, type of extraction solvent, volumes of acetonitrile and sample, amount of sodium hydroxide, vortexing and centrifugation times on the extraction efficiency were investigated. The upper layer, containing the biguanides, was directly injected into a HPLC unit using ZIC-HILIC column (150mm×2.1mm×3.5μm) and was detected at 236nm. The method was validated and calibration curves were linear with r2>0.99 over the range of 20-2000μgL-1for plasma and 5-2000μgL-1for urine and lake water samples. The limits of detection were in the range (3.8-5.6)μgL-1, (0.8-1.5)μgL-1and (0.3-0.8)μgL-1for plasma, urine and lake water, respectively. The accuracies in the three matrices were within 87.3-103%, 87.4-109%, 82.2-109% of the nominal concentration for metformin, buformin and phenformin, respectively. The relative standard deviation for inter- and intra -day precision were in the range of 1.0-17% for all analytes in the three matrices.
    MeSH terms: Acetonitriles; Biguanides/analysis*; Biguanides/isolation & purification*; Biguanides/urine; Biguanides/chemistry; Chromatography, High Pressure Liquid/methods*; Humans; Sodium Chloride; Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/isolation & purification*; Water Pollutants, Chemical/urine; Water Pollutants, Chemical/chemistry; Reproducibility of Results; Linear Models; Limit of Detection; Hydrophobic and Hydrophilic Interactions; Liquid-Liquid Extraction/methods*; Lakes/chemistry
  13. MubarakAli D, LewisOscar F, Gopinath V, Alharbi NS, Alharbi SA, Thajuddin N
    Microb Pathog, 2018 Jan;114:323-327.
    PMID: 29229504 DOI: 10.1016/j.micpath.2017.11.043
    Chitosan is the second most abundant polymer obtained from the byproduct of seafood. Chitosan and its derivatives and chitosan loaded drugs are the recent area of interest against microbial pathogenesis. The cationic chitosan nanoparticles (ChNPs) interact with the anionic surfaces of the microbial cell membrane, which promotes antimicrobial activity. Although, ChNPs are potential against pathogenic microbes, selection of adaptable, suitable and cost effective synthesis method is much important. In the present study, ChNPs were synthesized adopting ionic gelation using sodium tripolyphosphate as a cross linking agent and characterized by FTIR, DLS, SEM and TEM analysis. ChNPs were investigated for antimicrobial activity against bacterial (Escherichia coli and Staphylococcus aureus) and fungal (Candida albicans) pathogens. ChNPs showed bactericidal activity at the lower minimum inhibitory concentration of about 40-80 μg mL-1. Interestingly, ChNPs exhibits biocompatible antioxidant property by inhibiting DPPH free radicals at 76% and also proven to be a potential candidate against the microbial pathogenesis with an inevitable applications in biomedicine.
    MeSH terms: Anti-Infective Agents/pharmacology*; Antioxidants/pharmacology*; Bacteria/drug effects*; Biocompatible Materials/pharmacology*; Cell Survival/drug effects; Fungi/drug effects*; HeLa Cells/drug effects; Humans; Microbial Sensitivity Tests; Particle Size; Nanotechnology; Chitosan/antagonists & inhibitors*; Chitosan/chemistry; Nanoparticles/chemistry*
  14. Lung RW, Hau PM, Yu KH, Yip KY, Tong JH, Chak WP, et al.
    J Pathol, 2018 Apr;244(4):394-407.
    PMID: 29230817 DOI: 10.1002/path.5018
    Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignancy that is prevalent in southern China and Southeast Asia. It is consistently associated with latent Epstein-Barr virus (EBV) infection. In NPC, miR-BARTs, the EBV-encoded miRNAs derived from BamH1-A rightward transcripts, are abundantly expressed and contribute to cancer development by targeting various cellular and viral genes. In this study, we establish a comprehensive transcriptional profile of EBV-encoded miRNAs in a panel of NPC patient-derived xenografts and an EBV-positive NPC cell line by small RNA sequencing. Among the 40 miR-BARTs, predominant expression of 22 miRNAs was consistently detected in these tumors. Among the abundantly expressed EBV-miRNAs, BART5-5p, BART7-3p, BART9-3p, and BART14-3p could negatively regulate the expression of a key DNA double-strand break (DSB) repair gene, ataxia telangiectasia mutated (ATM), by binding to multiple sites on its 3'-UTR. Notably, the expression of these four miR-BARTs represented more than 10% of all EBV-encoded miRNAs in tumor cells, while downregulation of ATM expression was commonly detected in all of our tested sequenced samples. In addition, downregulation of ATM was also observed in primary NPC tissues in both qRT-PCR (16 NP and 45 NPC cases) and immunohistochemical staining (35 NP and 46 NPC cases) analysis. Modulation of ATM expression by BART5-5p, BART7-3p, BART9-3p, and BART14-3p was demonstrated in the transient transfection assays. These findings suggest that EBV uses miRNA machinery as a key mechanism to control the ATM signaling pathway in NPC cells. By suppressing these endogenous miR-BARTs in EBV-positive NPC cells, we further demonstrated the novel function of miR-BARTs in inhibiting Zta-induced lytic reactivation. These findings imply that the four viral miRNAs work co-operatively to modulate ATM activity in response to DNA damage and to maintain viral latency, contributing to the tumorigenesis of NPC. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
    MeSH terms: Animals; Binding Sites; DNA Damage; Enzyme Repression; Herpesvirus 4, Human/genetics*; Female; Humans; Male; Mice, Nude; Middle Aged; Nasopharyngeal Neoplasms/enzymology; Nasopharyngeal Neoplasms/genetics*; Nasopharyngeal Neoplasms/pathology; Nasopharyngeal Neoplasms/virology; RNA, Viral/genetics*; Gene Expression Regulation, Neoplastic; Virus Latency; Epstein-Barr Virus Infections/diagnosis; Epstein-Barr Virus Infections/virology*; 3' Untranslated Regions; MicroRNAs/genetics*; Cell Line, Tumor; Host-Pathogen Interactions; Transcriptome; Ataxia Telangiectasia Mutated Proteins/biosynthesis; Ataxia Telangiectasia Mutated Proteins/genetics*; Heterografts
  15. Leong SW, Lim TS, Ismail A, Choong YS
    J. Mol. Recognit., 2018 05;31(5):e2695.
    PMID: 29230887 DOI: 10.1002/jmr.2695
    With the development of de novo binders for protein targets from non-related scaffolds, many possibilities for therapeutics and diagnostics have been created. In this study, we described the use of de novo design approach to create single-chain fragment variable (scFv) for Salmonella enterica subspecies enterica serovar Typhi TolC protein. Typhoid fever is a global health concern in developing and underdeveloped countries. Rapid typhoid diagnostics will improve disease management and therapy. In this work, molecular dynamics simulation was first performed on a homology model of TolC protein in POPE membrane bilayer to obtain the central structure that was subsequently used as the target for scFv design. Potential hotspot residues capable of anchoring the binders to the target were identified by docking "disembodied" amino acid residues against TolC surface. Next, scFv scaffolds were selected from Protein Data Bank to harbor the computed hotspot residues. The hotspot residues were then incorporated into the scFv scaffold complementarity determining regions. The designs recapitulated binding energy, shape complementarity, and interface surface area of natural protein-antibody interfaces. This approach has yielded 5 designs with high binding affinity against TolC that may be beneficial for the future development of antigen-based detection agents for typhoid diagnostics.
    MeSH terms: Bacterial Outer Membrane Proteins/immunology*; Bacterial Outer Membrane Proteins/chemistry; Humans; Salmonella typhi/immunology; Salmonella typhi/metabolism*; Typhoid Fever/diagnosis; Drug Design; Sequence Homology; Databases, Protein; Molecular Dynamics Simulation; Single-Chain Antibodies/chemistry*
  16. Omar NH, Mohd M, Mohamed Nor NMI, Zakaria L
    Microb Pathog, 2018 Jan;114:362-368.
    PMID: 29233777 DOI: 10.1016/j.micpath.2017.12.026
    Leaf spot diseases are mainly caused by fungi including Fusarium. In the present study several species of Fusarium were isolated from the leaf spot lesion of mango (Mangifera indica L.) Based on morphological characteristics, TEF-1α sequences and phylogenetic analysis, five species were identified as F. proliferatum, F. semitectum, F. mangiferae, F. solani and F. chlamydosporum. Pathogenicity test indicated that representative isolates of F. proliferatum, F. semitectum and F. chlamydosporum were pathogenic on mango leaves causing leaf spot with low to moderate virulence. Nevertheless, abundance of spots on the leaf can disrupt photosynthesis which in turn reduced growth, and lead to susceptibility to infection by opportunistic pathogens due to weakening of the plant. Fusarium solani and F. mangiferae were non-pathogenic and it is possible that both species are saprophyte which associated with nutrient availability on the surface of the leaf through decaying leave tissues. The occurrence of Fusarium spp. on the leaf spot lesion and the effect from the disease needs to be considered when developing disease management method of mango cultivation as numerous spot on the leaves could effect the photosynthesis process and finally giving low yield and less quality of mango.
    MeSH terms: DNA, Fungal; Fusarium/cytology*; Fusarium/genetics; Fusarium/isolation & purification*; Fusarium/pathogenicity*; Genes, Fungal; Malaysia; Phylogeny; Plant Diseases/microbiology*; Spores, Fungal/cytology; Virulence; Plant Leaves/microbiology; Mangifera/microbiology*
  17. Maniam R, Selvarajah GT, Mazlan M, Lung Than LT
    Med Mycol Case Rep, 2018 Mar;19:25-29.
    PMID: 29234587 DOI: 10.1016/j.mmcr.2017.11.005
    Papillary adenocarcinoma of the lungs is the most common primary lung adenocarcinoma, with the feature of papillary-like structure formation by cells. A dog was presented with the primary complaint of vomiting, hyporexia and increased respiratory effort. Thoracic radiography revealed increased soft tissue radiopacity of the right cranial lung lobe suggestive of possible consolidation or collapsed lung lobe, with generalised miliary nodular pattern throughout the other lung fields. The dog was euthanized humanely and necropsy was performed. Histopathology confirmed the diagnosis of primary pulmonary lung neoplasm (papillary adenocarcinoma) with Aspergillus versicolor infection identified through fungal culture and PCR. There have been several reports on humans and dogs with fungal infections that often mimic or coexist with pulmonary neoplasm. This is the first documented report of A. versicolor isolated from a lung neoplasm in a dog in Malaysia.
  18. Ombao H, Fiecas M, Ting CM, Low YF
    Neuroimage, 2018 Oct 15;180(Pt B):609-618.
    PMID: 29223740 DOI: 10.1016/j.neuroimage.2017.11.061
    Most neuroscience cognitive experiments involve repeated presentations of various stimuli across several minutes or a few hours. It has been observed that brain responses, even to the same stimulus, evolve over the course of the experiment. These changes in brain activation and connectivity are believed to be associated with learning and/or habituation. In this paper, we present two general approaches to modeling dynamic brain connectivity using electroencephalograms (EEGs) recorded across replicated trials in an experiment. The first approach is the Markovian regime-switching vector autoregressive model (MS-VAR) which treats EEGs as realizations of an underlying brain process that switches between different states both within a trial and across trials in the entire experiment. The second is the slowly evolutionary locally stationary process (SEv-LSP) which characterizes the observed EEGs as a mixture of oscillatory activities at various frequency bands. The SEv-LSP model captures the dynamic nature of the amplitudes of the band-oscillations and cross-correlations between them. The MS-VAR model is able to capture abrupt changes in the dynamics while the SEv-LSP directly gives interpretable results. Moreover, it is nonparametric and hence does not suffer from model misspecification. For both of these models, time-evolving connectivity metrics in the frequency domain are derived from the model parameters for both functional and effective connectivity. We illustrate these two models for estimating cross-trial connectivity in selective attention using EEG data from an oddball paradigm auditory experiment where the goal is to characterize the evolution of brain responses to target stimuli and to standard tones presented randomly throughout the entire experiment. The results suggest dynamic changes in connectivity patterns over trials with inter-subject variability.
    MeSH terms: Cognitive Neuroscience; Attention; Brain; Cognition; Electroencephalography; Goals; Learning
  19. Taha M, Imran S, Rahim F, Wadood A, Khan KM
    Bioorg Chem, 2018 02;76:273-280.
    PMID: 29223804 DOI: 10.1016/j.bioorg.2017.12.001
    Inhibition of α-glucosidase is an effective strategy for controlling post-prandial hyperglycemia in diabetic patients. Beside these α-glucosidase inhibitors has been also used as anti-obesity and anti-viral drugs. Keeping in view the greater importance of α-glucosidase inhibitors here in this study we are presenting oxindole based oxadiazoles hybrid analogs (1-20) synthesis, characterized by different spectroscopic techniques including 1H NMR and EI-MS and their α-glucosidase inhibitory activity. All compounds were found potent inhibitors for the enzyme with IC50 values ranging between 1.25 ± 0.05 and 268.36 ± 4.22 µM when compared with the standard drug acarbose having IC50 value 895.09 ± 2.04 µM. Our study identifies novel series of potent α-glucosidase inhibitors and further investigation on this may led to the lead compounds. A structure activity relationship has been established for all compounds. The interactions of the active compounds and enzyme active site were established with the help of molecular docking studies.
    MeSH terms: alpha-Glucosidases/metabolism; alpha-Glucosidases/chemistry; Hydrogen Bonding; Oxadiazoles/chemical synthesis; Oxadiazoles/metabolism; Oxadiazoles/chemistry*; Protein Binding; Structure-Activity Relationship; Molecular Structure; Catalytic Domain; Enzyme Assays; Molecular Docking Simulation; Glycoside Hydrolase Inhibitors/chemical synthesis; Glycoside Hydrolase Inhibitors/metabolism; Glycoside Hydrolase Inhibitors/chemistry*
  20. Homouz D, Joyce-Tan KH, Shahir Shamsir M, Moustafa IM, Idriss H
    J Mol Graph Model, 2018 01;79:192.
    PMID: 29223917 DOI: 10.1016/j.jmgm.2017.11.002
    DNA polymerase β is a 39kDa enzyme that is a major component of Base Excision Repair in human cells. The enzyme comprises two major domains, a 31kDa domain responsible for the polymerase activity and an 8kDa domain, which bind ssDNA and has a deoxyribose phosphate (dRP) lyase activity. DNA polymerase β was shown to be phosphorylated in vitro with protein kinase C (PKC) at serines 44 and 55 (S44 and S55), resulting in loss of its polymerase enzymic activity, but not its ability to bind ssDNA. In this study, we investigate the potential phosphorylation-induced structural changes for DNA polymerase β using molecular dynamics. The simulations show drastic conformational changes of the polymerase structure as a result of S44 phosphorylation. Phosphorylation-induced conformational changes transform the closed (active) enzyme structure into an open one. Further analysis of the results points to a key hydrogen bond and newly formed salt bridges as potential drivers of these structural fluctuations. The changes observed with S44/55 and S55 phosphorylation were less dramatic than S44 and the integrity of the H-bond was not compromised. Thus the phosphorylation of S44 is likely the major contributor to structural fluctuations that lead to loss of enzymatic activity.
    MeSH terms: Deoxyribose; DNA Repair; DNA Replication; DNA, Single-Stranded; Humans; Hydrogen; Hydrogen Bonding; Lyases; Phosphates; Phosphorylation; Protein Kinase C; Serine; DNA Polymerase beta; Molecular Dynamics Simulation
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