Displaying publications 81 - 100 of 314 in total

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  1. Kong SR, Yamamoto M, Shaari H, Hayashi R, Seki O, Mohd Tahir N, et al.
    PLoS One, 2021;16(9):e0256853.
    PMID: 34495997 DOI: 10.1371/journal.pone.0256853
    The reconstruction of fire history is essential to understand the palaeoclimate and human history. Polycyclic aromatic hydrocarbons (PAHs) have been extensively used as a fire marker. In this work, the distribution of PAHs in Borneo peat archives was investigated to understand how PAHs reflect the palaeo-fire activity. In total, 52 peat samples were analysed from a Borneo peat core for the PAH analysis. Pyrogenic PAHs consist of 2-7 aromatic rings, some of which have methyl and ethyl groups. The results reveal that the concentration of pyrogenic PAHs fluctuated with the core depth. Compared to low-molecular-weight (LMW) PAHs, the high-molecular-weight (HMW) PAHs had a more similar depth variation to the charcoal abundance. This finding also suggests that the HMW PAHs were mainly formed at a local fire near the study area, while the LMW PAHs could be transported from remote locations.
    Matched MeSH terms: Molecular Weight
  2. Sayyed RZ, Wani SJ, Alarfaj AA, Syed A, El-Enshasy HA
    PLoS One, 2020;15(1):e0220095.
    PMID: 31910206 DOI: 10.1371/journal.pone.0220095
    There are numerous reports on poly-β-hydroxybutyrate (PHB) depolymerases produced by various microorganisms isolated from various habitats, however, reports on PHB depolymerase production by an isolate from plastic rich sites scares. Although PHB has attracted commercial significance, the inefficient production and recovery methods, inefficient purification of PHB depolymerase and lack of ample knowledge on PHB degradation by PHB depolymerase have hampered its large scale commercialization. Therefore, to ensure the biodegradability of biopolymers, it becomes imperative to study the purification of the biodegrading enzyme system. We report the production, purification, and characterization of extracellular PHB depolymerase from Stenotrophomonas sp. RZS7 isolated from a dumping yard rich in plastic waste. The isolate produced extracellular PHB depolymerase in the mineral salt medium (MSM) at 30°C during 4 days of incubation under shaking. The enzyme was purified by three methods namely ammonium salt precipitation, column chromatography, and solvent purification. Among these purification methods, the enzyme was best purified by column chromatography on the Octyl-Sepharose CL-4B column giving optimum yield (0.7993 Umg-1mL-1). The molecular weight of purified PHB depolymerase was 40 kDa. Studies on the assessment of biodegradation of PHB in liquid culture medium and under natural soil conditions confirmed PHB biodegradation potential of Stenotrophomonas sp. RZS7. The results obtained in Fourier-Transform Infrared (FTIR) analysis, High-Performance Liquid Chromatography (HPLC) study and Gas Chromatography Mass-Spectrometry (GC-MS) analysis confirmed the biodegradation of PHB in liquid medium by Stenotrophomonas sp. RZS7. Changes in surface morphology of PHB film in soil burial as observed in Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the biodegradation of PHB under natural soil environment. The isolate was capable of degrading PHB and it resulted in 87.74% biodegradation. A higher rate of degradation under the natural soil condition is the result of the activity of soil microbes that complemented the biodegradation of PHB by Stenotrophomonas sp. RZS7.
    Matched MeSH terms: Molecular Weight
  3. Garba L, Mohamad Ali MS, Oslan SN, Rahman RN
    PLoS One, 2016;11(8):e0160681.
    PMID: 27494717 DOI: 10.1371/journal.pone.0160681
    Fatty acid desaturase enzymes play an essential role in the synthesis of unsaturated fatty acids. Pseudomonas sp. A3 was found to produce a large amount of palmitoleic and oleic acids after incubation at low temperatures. Using polymerase Chain Reaction (PCR), a novel Δ9- fatty acid desaturase gene was isolated, cloned, and successfully expressed in Escherichia coli. The gene was designated as PA3FAD9 and has an open reading frame of 1,185 bp which codes for 394 amino acids with a predicted molecular weight of 45 kDa. The activity of the gene product was confirmed via GCMS, which showed a functional putative Δ9-fatty acid desaturase capable of increasing the total amount of cellular unsaturated fatty acids of the E. coli cells expressing the gene. The results demonstrate that the cellular palmitoleic acids have increased two-fold upon expression at 15°C using only 0.1 mM IPTG. Therefore, PA3FAD9 from Pseudomonas sp.A3 codes for a Δ9-fatty acid desaturase-like protein which was actively expressed in E. coli.
    Matched MeSH terms: Molecular Weight
  4. Kasim S, Amir Rudin PNF, Malek S, Aziz F, Wan Ahmad WA, Ibrahim KS, et al.
    PLoS One, 2024;19(2):e0298036.
    PMID: 38358964 DOI: 10.1371/journal.pone.0298036
    BACKGROUND: Traditional risk assessment tools often lack accuracy when predicting the short- and long-term mortality following a non-ST-segment elevation myocardial infarction (NSTEMI) or Unstable Angina (UA) in specific population.

    OBJECTIVE: To employ machine learning (ML) and stacked ensemble learning (EL) methods in predicting short- and long-term mortality in Asian patients diagnosed with NSTEMI/UA and to identify the associated features, subsequently evaluating these findings against established risk scores.

    METHODS: We analyzed data from the National Cardiovascular Disease Database for Malaysia (2006-2019), representing a diverse NSTEMI/UA Asian cohort. Algorithm development utilized in-hospital records of 9,518 patients, 30-day data from 7,133 patients, and 1-year data from 7,031 patients. This study utilized 39 features, including demographic, cardiovascular risk, medication, and clinical features. In the development of the stacked EL model, four base learner algorithms were employed: eXtreme Gradient Boosting (XGB), Support Vector Machine (SVM), Naive Bayes (NB), and Random Forest (RF), with the Generalized Linear Model (GLM) serving as the meta learner. Significant features were chosen and ranked using ML feature importance with backward elimination. The predictive performance of the algorithms was assessed using the area under the curve (AUC) as a metric. Validation of the algorithms was conducted against the TIMI for NSTEMI/UA using a separate validation dataset, and the net reclassification index (NRI) was subsequently determined.

    RESULTS: Using both complete and reduced features, the algorithm performance achieved an AUC ranging from 0.73 to 0.89. The top-performing ML algorithm consistently surpassed the TIMI risk score for in-hospital, 30-day, and 1-year predictions (with AUC values of 0.88, 0.88, and 0.81, respectively, all p < 0.001), while the TIMI scores registered significantly lower at 0.55, 0.54, and 0.61. This suggests the TIMI score tends to underestimate patient mortality risk. The net reclassification index (NRI) of the best ML algorithm for NSTEMI/UA patients across these periods yielded an NRI between 40-60% (p < 0.001) relative to the TIMI NSTEMI/UA risk score. Key features identified for both short- and long-term mortality included age, Killip class, heart rate, and Low-Molecular-Weight Heparin (LMWH) administration.

    CONCLUSIONS: In a broad multi-ethnic population, ML approaches outperformed conventional TIMI scoring in classifying patients with NSTEMI and UA. ML allows for the precise identification of unique characteristics within individual Asian populations, improving the accuracy of mortality predictions. Continuous development, testing, and validation of these ML algorithms holds the promise of enhanced risk stratification, thereby revolutionizing future management strategies and patient outcomes.

    Matched MeSH terms: Heparin, Low-Molecular-Weight
  5. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.
    Phys Rev Lett, 2015 Feb 13;114(6):061801.
    PMID: 25723204
    A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at √[s]=8  TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7  fb(-1). Events are selected with an electron and muon with opposite charges that both have transverse impact parameter values between 0.02 and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt e-μ final states. Limits are set on the "displaced supersymmetry" model, with pair production of top squarks decaying into an e-μ final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to cτ=2  cm, excluding masses below 790 GeV at 95% confidence level.
    Matched MeSH terms: Molecular Weight
  6. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2019 Jan 11;122(1):011803.
    PMID: 31012697 DOI: 10.1103/PhysRevLett.122.011803
    A search is performed for dark matter particles produced in association with a top quark pair in proton-proton collisions at sqrt[s]=13  TeV. The data correspond to an integrated luminosity of 35.9  fb^{-1} recorded by the CMS detector at the LHC. No significant excess over the standard model expectation is observed. The results are interpreted using simplified models of dark matter production via spin-0 mediators that couple to dark matter particles and to standard model quarks, providing constraints on the coupling strength between the mediator and the quarks. These are the most stringent collider limits to date for scalar mediators, and the most stringent for pseudoscalar mediators at low masses.
    Matched MeSH terms: Molecular Weight
  7. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Brandstetter J, et al.
    Phys Rev Lett, 2019 Sep 27;123(13):131802.
    PMID: 31697516 DOI: 10.1103/PhysRevLett.123.131802
    A search for a light charged Higgs boson (H^{+}) decaying to a W boson and a CP-odd Higgs boson (A) in final states with eμμ or μμμ is performed using data from pp collisions at sqrt[s]=13  TeV, recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9  fb^{-1}. In this search, it is assumed that the H^{+} boson is produced in decays of top quarks, and the A boson decays to two oppositely charged muons. The presence of signals for H^{+} boson masses between 100 and 160 GeV and A boson masses between 15 and 75 GeV is investigated. No evidence for the production of the H^{+} boson is found. Upper limits at 95% confidence level are obtained on the combined branching fraction for the decay chain, t→bH^{+}→bW^{+}A→bW^{+}μ^{+}μ^{-}, of 1.9×10^{-6} to 8.6×10^{-6}, depending on the masses of the H^{+} and A bosons. These are the first limits for these decay modes of the H^{+} and A bosons.
    Matched MeSH terms: Molecular Weight
  8. Chachuli SH, Nawaz A, Shah K, Naharudin I, Wong TW
    Pharm Res, 2016 06;33(6):1497-508.
    PMID: 26951565 DOI: 10.1007/s11095-016-1893-5
    PURPOSE: Pulmonary infection namely tuberculosis is characterized by alveolar macrophages harboring a large microbe population. The chitosan nanoparticles exhibit fast extracellular drug release in aqueous biological milieu. This study investigated the matrix effects of chitosan nanoparticles on extracellular drug diffusion into macrophages.

    METHODS: Oligo, low, medium and high molecular weight chitosan nanoparticles were prepared by nanospray drying technique. These nanoparticles were incubated with alveolar macrophages in vitro and had model drug sodium fluorescein added into the same cell culture. The diffusion characteristics of sodium fluorescein and nanoparticle behavior were investigated using fluorescence microscopy, scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques.

    RESULTS: The oligochitosan nanoparticles enabled macrophage membrane fluidization with the extent of sodium fluorescein entry into macrophages being directly governed by the nanoparticle loading. Using nanoparticles made of higher molecular weight chitosan, sodium fluorescein permeation into macrophages was delayed due to viscous chitosan diffusion barrier at membrane boundary.

    CONCLUSION: Macrophage-chitosan nanoparticle interaction at membrane interface dictates drug migration into cellular domains.

    Matched MeSH terms: Molecular Weight
  9. Bakhshan, Y., Shahrir Abdullah
    MyJurnal
    An in-house quasi-dimensional code has been developed which simulate the overlap, intake, compression, combustion, as well as expansion and exhaust processes of a homogeneous charged internal combustion engine (ICE). A detailed chemical kinetic mechanism, constituting of 39 species and 148 elementary reactions, has been used in conjunction with above code to study the combustion of CNG under IC engine conditions. Two different criteria, based on pressure rise and mass of fuel burned, are used to detect the onset of ignition. Parametric studies are conducted to show the effect of compression ratio, initial pressure, intake temperature and equivalence ratio, on the time of ignition and fuel burning rate. The results obtained from the modelling show a good agreement with the experimental data.
    Matched MeSH terms: Molecular Weight
  10. Tay C. L., Law M. C.
    MyJurnal
    The modelling of a three-dimensional (3-D) molten carbonate fuel cell (MCFC) was developed to study the effects of gas flow direction (co-flow and counter-flow) in anode and cathode on the generated power density by solving the mass and momentum conservation equations, electrochemical reaction and heat transfer. The simulation result of the co-flow temperature distribution was compared with the experimental data obtained from open literature. The molar fraction distribution of gases in the anode and cathode gas channels and temperature distribution across the cell were compared between two different flow directions. Furthermore, the performance of MCFC, which operates in the temperature range of 823 - 1023 K, was analysed by comparing the generated power density. The results showed that MCFC with co-flow attained higher power density compared to that of counter-flow at 873 K. However, at higher temperature of 1023 K, the generated power density was the same for both gas flow directions.
    Matched MeSH terms: Molecular Weight
  11. Muskhazli Mustafa, Nor Azwady Abd. Aziz, Anida Kaimi, Nurul Shafiza Noor, Salifah Hasanah Ahmad Bedawi, Nalisha Ithnin
    MyJurnal
    The β-1,6-glucanases are ubiquitous enzymes which appear to be implicated in the morphogenesis and have the ability to become virulence factor in plant-fungal symbiotic interaction. To our knowledge, no report on ß-1,6-glucanases purification from Trichoderma longibrachiatum has been made, although it has been proven to have a significant effect as a biocontrol agent for several diseases. Therefore, the aim of this study was to purify β-1,6- glucanase from T. longibrachiatum T28, with an assessment on the physicochemical properties and substrate specificity. β-1,3-glucanase enzyme, from the culture filtrate of T. longibrachiatum T28, was successively purified through precipitation with 80% acetone, followed by anionexchange chromatography on Neobar AQ and chromatofocusing on a Mono P HR 5/20 column. (One β-1,6-glucanase) band at 42kDa in size was purified, as shown by the SDS-PAGE. The physicochemical evaluation showed an optimum pH of 5 and optimum temperature of 50°C for enzyme activity with an ability to maintain 100% enzyme stability. Enzyme activity was slightly reduced by 10-20% in the presence of 20 mM of Zn2+, Ca2+, Co2+, Mg2+, Cu2+, Mn2+ and Fe2+. The highest β-1,6-glucanase hydrolysis activity was obtained on pustulan due to the similarity of β-glucosidic bonds followed by laminarin, glucan and cellulose. Therefore, it can be concluded that the characterization of ß-1,6-glucanase secreted by T. longibrachiatum in term of molecular weight, responsed to selected physicochemical factors and the substrate specificity are approximately identical to other Trichoderma sp.
    Matched MeSH terms: Molecular Weight
  12. Shodiya, S., Azhar, A. A., Darus, A. N.
    MyJurnal
    HCFCs, in addition to destroying the ozone layer, have been recognized as a contributing factor that increases global warming. It is widely used as working fluid in window air-conditioning system, where capillary tube serves as an expansion device. Literature reports have shown that no single refrigerant can solve the problem of ozone layer depletion and global warming. Refrigerant HC290/HC600a/HFC407C mixture, an eco-friendly refrigerant, has been recognized as an alternative to HCFC22. The objective of this study is to, for cost effectiveness, develop an empirical correlation to predict the refrigerant HC290/ HC600a/HFC407C mixture mass flow rate using statistical experimental design approach. A review of relevant literature shows that refrigerant’s mass flow rate depends on condensing temperature, degree of subcooling, inner diameter and length of capillary tube. The relationship between the mass flow rate and the four independent variables was established as an empirical mathematical correlation using central composite design (CCD), a response surface methodology (RSM). This empirical correlation was examined using analysis of variance (ANOVA) of 5% level of significance. The results of these analysis showed that the correlation fitted well with the experimental data yielding an average and standard deviation of 1.05% and 2.62%, respectively. The validity of the present correlation was further assessed by comparing it with published empirical correlation in literature and the result showed that the present correlation is consistent.
    Matched MeSH terms: Molecular Weight
  13. Aidah Jumahat, Napisah Sapiai, Eliya Farah Hana Mohd Kamal
    MyJurnal
    This paper investigates the effect of acid and silane treatment of Carbon Nanotubes (CNT) on wear properties of epoxy polymer composite. The wear test done was based on ASTM D3389 standard using the Abrasive Wear Tester (TR 600). Characterisation analysis was also done using Transmission Electron Microscopy (TEM) in order to study the dispersion of the CNT inside the epoxy matrix. When untreated CNT was added to the epoxy with amounts of 0.5, 0.75 and 1.0 wt%, the wear rates did not improve except for 0.5 wt% CNT filled epoxy. This was due to the lack of dispersion which causes larger chunks of material being dug out, thus contributing to a higher mass loss and wear rate. When treated with acid and silane, 0.75 wt% and 1.0 wt% CNT filled epoxy composites showed improvement. The TEM images of 0.5 wt%, 0.75 wt% and 1.0 wt% PCNT filled epoxy supported the claim of the lack of dispersion of PCNT inside the epoxy.
    Matched MeSH terms: Molecular Weight
  14. Hao, Lim Zhen, Hikmat Said Al-Salim, Norida Ridzuan
    MyJurnal
    The continuous depletion of global oil reserves with the propensity for light distillates
    propels the oil and gas industry to explore heavier fractions of crude oils with significant
    amount of paraffin waxes. However, the precipitation and deposition of waxes during the
    transportation of these waxy crude oils in the pipelines contribute to several issues, such as
    the flowability reduction, excessive pumping cost, and wax gel formation, that adversely
    affect the supposedly steady offshore oil production. As a result, substantial resources are
    expended to resolve these flow assurance problems. The wax inhibitors and pour point
    depressants are developed and modified to meet the wax remediation criteria. Essentially,
    the wax crystals are formed through the nucleation, growth, and agglomeration processes,
    while the deposition of these waxes occurs via molecular diffusion and shear dispersion.
    The wax inhibitors are able to control the growth of wax crystals through nucleation, cocrystallization,
    adsorption, and dispersion interactions. This paper particularly assessed
    the following compounds: (1) polymeric wax inhibitors, (2) nano-hybrid pour point
    depressants, (3) organic solvents, and
    (4) surfactants. Given the significance of
    these compounds in the deposition and
    precipitation of waxes, it is imperative to
    comprehensively explore the types and
    nature of these compounds and their recent
    applications as well as to critically assess
    their strengths and drawbacks, which were
    addressed in this paper. Furthermore, the
    challenges of using these compounds and the factors that govern their efficiencies were also discussed. Accordingly, the carbon
    length and the molecular weight of both paraffin waxes and wax inhibitors are among the
    most influential factors.
    Matched MeSH terms: Molecular Weight
  15. Zheng W, Mutha NV, Heydari H, Dutta A, Siow CC, Jakubovics NS, et al.
    PeerJ, 2016;4:e1698.
    PMID: 27017950 DOI: 10.7717/peerj.1698
    Background. The gram-negative Neisseria is associated with two of the most potent human epidemic diseases: meningococcal meningitis and gonorrhoea. In both cases, disease is caused by bacteria colonizing human mucosal membrane surfaces. Overall, the genus shows great diversity and genetic variation mainly due to its ability to acquire and incorporate genetic material from a diverse range of sources through horizontal gene transfer. Although a number of databases exist for the Neisseria genomes, they are mostly focused on the pathogenic species. In this present study we present the freely available NeisseriaBase, a database dedicated to the genus Neisseria encompassing the complete and draft genomes of 15 pathogenic and commensal Neisseria species. Methods. The genomic data were retrieved from National Center for Biotechnology Information (NCBI) and annotated using the RAST server which were then stored into the MySQL database. The protein-coding genes were further analyzed to obtain information such as calculation of GC content (%), predicted hydrophobicity and molecular weight (Da) using in-house Perl scripts. The web application was developed following the secure four-tier web application architecture: (1) client workstation, (2) web server, (3) application server, and (4) database server. The web interface was constructed using PHP, JavaScript, jQuery, AJAX and CSS, utilizing the model-view-controller (MVC) framework. The in-house developed bioinformatics tools implemented in NeisseraBase were developed using Python, Perl, BioPerl and R languages. Results. Currently, NeisseriaBase houses 603,500 Coding Sequences (CDSs), 16,071 RNAs and 13,119 tRNA genes from 227 Neisseria genomes. The database is equipped with interactive web interfaces. Incorporation of the JBrowse genome browser in the database enables fast and smooth browsing of Neisseria genomes. NeisseriaBase includes the standard BLAST program to facilitate homology searching, and for Virulence Factor Database (VFDB) specific homology searches, the VFDB BLAST is also incorporated into the database. In addition, NeisseriaBase is equipped with in-house designed tools such as the Pairwise Genome Comparison tool (PGC) for comparative genomic analysis and the Pathogenomics Profiling Tool (PathoProT) for the comparative pathogenomics analysis of Neisseria strains. Discussion. This user-friendly database not only provides access to a host of genomic resources on Neisseria but also enables high-quality comparative genome analysis, which is crucial for the expanding scientific community interested in Neisseria research. This database is freely available at http://neisseria.um.edu.my.
    Matched MeSH terms: Molecular Weight
  16. Teo MYM, Ng JJC, Fong JY, Hwang JS, Song AA, Lim RLH, et al.
    PeerJ, 2021;9:e11063.
    PMID: 33959410 DOI: 10.7717/peerj.11063
    Background: KRAS oncogenes harboring codon G12 and G13 substitutions are considered gatekeeper mutations which drive oncogenesis in many cancers. To date, there are still no target-specific vaccines or drugs available against this genotype, thus reinforcing the need towards the development of targeted therapies such as immunotoxins.

    Methods: This study aims to develop a recombinant anti-mKRAS scFv-fused mutant Hydra actinoporin-like-toxin-1 (mHALT-1) immunotoxin that is capable of recognizing and eradicating codon-12 mutated k-ras antigen abnormal cells. One G13D peptide mimotope (164-D) and one G12V peptide mimotope (68-V) were designed to elicit antigen specific IgG titres against mutated K-ras antigens in immunised Balb/c mice. The RNA was extracted from splenocytes following ELISA confirmation on post-immunized mice sera and was reverse transcribed into cDNA. The scFv combinatorial library was constructed from cDNA repertoire of variable regions of heavy chain (VH) and light chain (VL) fusions connected by a flexible glycine-serine linker, using splicing by overlap extension PCR (SOE-PCR). Anti-mKRAS G12V and G13D scFvs were cloned in pCANTAB5E phagemid and superinfected with helper phage. After few rounds of bio-panning, a specific mKRAS G12V and G13D scFv antibody against G12V and G13D control mimotope was identified and confirmed using ELISA without any cross-reactivity with other mimotopes or controls. Subsequently, the anti-mKRAS scFv was fused to mHALT-1 using SOE-PCR and cloned in pET22b vector. Expressed recombinant immunotoxins were analyzed for their effects on cell proliferation by the MTT assay and targeted specificity by cell-based ELISA on KRAS-positive and KRAS-negative cancer cells.

    Results: The VH and VL genes from spleen RNA of mice immunized with 164-D and 68-V were amplified and randomly linked together, using SOE-PCR producing band sizes about 750 bp. Anti-mKRAS G12V and G13D scFvs were constructed in phagemid pCANTAB5E vectors with a library containing 3.4 × 106 and 2.9 × 106 individual clones, respectively. After three rounds of bio-panning, the anti-mKRAS G12V-34 scFv antibody against G12V control mimotope was identified and confirmed without any cross-reactivity with other controls using ELISA. Anti-mKRAS G12V-34 scFv fragment was fused to mHALT-1 toxin and cloned in pET22b vector with expression as inclusion bodies in E. coli BL21(DE3) (molecular weight of ~46.8 kDa). After successful solubilization and refolding, the mHALT-1-scFv immunotoxin exhibited cytotoxic effects on SW-480 colorectal cancer cells with IC50 of 25.39 μg/mL, with minimal cytotoxicity effect on NHDF cells.

    Discussion: These results suggested that the development of such immunotoxins is potentially useful as an immunotherapeutic application against KRAS-positive malignancies.

    Matched MeSH terms: Molecular Weight
  17. Kong BH, Teoh KH, Tan NH, Tan CS, Ng ST, Fung SY
    PeerJ, 2020;8:e9650.
    PMID: 32832273 DOI: 10.7717/peerj.9650
    Background: Lignosus tigris, a recently discovered species of the unique Lignosus family, has been traditionally used by the indigenous communities in Peninsular Malaysia to treat various ailments and as an alternative medicine for cancer treatment. The L. tigris cultivar sclerotia (Ligno TG-K) was found to contain numerous bioactive compounds with beneficial biomedicinal properties and the sclerotial extract exhibited potent antioxidant activity. However, the anticancer property of the Ligno TG-K including in vitro and in vivo antitumor effects as well as its anticancer active compounds and the mechanisms has yet to be investigated.

    Methods: The cytotoxicity of the Ligno TG-K against human breast (MCF7), prostate (PC3) and lung (A549) adenocarcinoma cell lines was evaluated using MTT cytotoxicity assay. The cytotoxic mechanisms of the active high molecular weight proteins (HMWp) fraction were investigated through detection of caspases activity and apoptotic-related proteins expression by Western blotting. The in vivo antitumor activity of the isolated HMWp was examined using MCF7 mouse xenograft model. Shotgun LC-MS/MS analysis was performed to identify the proteins in the HMWp.

    Results and Discussion: Cold water extract of the sclerotia inhibited proliferation of MCF7, A549 and PC3 cells with IC50 ranged from 28.9 to 95.0 µg/mL. Bioassay guided fractionation of the extract revealed that HMWp exhibited selective cytotoxicity against MCF7 cells via induction of cellular apoptosis by the activation of extrinsic and intrinsic signaling pathways. HMWp activated expression of caspase-8 and -9 enzymes, and pro-apoptotic Bax protein whilst inhibiting expression of tumor survivor protein, Bcl-2. HMWp induced tumor-cell apoptosis and suppressed growth of tumor in MCF-7 xenograft mice. Lectins, serine proteases, RNase Gf29 and a 230NA deoxyribonuclease are the major cytotoxic proteins that accounted for 55.93% of the HMWp.

    Conclusion: The findings from this study provided scientific evidences to support the traditional use of the L. tigris sclerotia for treatment of breast cancer. Several cytotoxic proteins with high abundance have been identified in the HMWp of the sclerotial extract and these proteins have potential to be developed into new anticancer agents or as adjunct cancer therapy.

    Matched MeSH terms: Molecular Weight
  18. Latip W, Raja Abd Rahman RNZ, Chor Leow AT, Mohd Shariff F, Mohamad Ali MS
    PeerJ, 2016;4:e2420.
    PMID: 27781152 DOI: 10.7717/peerj.2420
    A gene encoding a thermotolerant lipase with broad pH was isolated from an Antarctic Pseudomonas strain AMS3. The recombinant lipase AMS3 was purified by single-step purification using affinity chromatography, yielding a purification fold of approximately 1.52 and a recovery of 50%. The molecular weight was approximately ∼60 kDa including the strep and affinity tags. Interestingly, the purified Antarctic AMS3 lipase exhibited broad temperature profile from 10-70 °C and stable over a broad pH range from 5.0 to pH 10.0. Various mono and divalent metal ions increased the activity of the AMS3 lipase, but Ni(2+) decreased its activity. The purified lipase exhibited the highest activity in the presence of sunflower oil. In addition, the enzyme activity in 25% v/v solvents at 50 °C particularly to n-hexane, DMSO and methanol could be useful for catalysis reaction in organic solvent and at broad temperature.
    Matched MeSH terms: Molecular Weight
  19. Siti Hajar MH, Zulkefli S, Juwita S, Norhayati MN, Siti Suhaila MY, Rasool AHG, et al.
    PeerJ, 2018;6:e5758.
    PMID: 30356972 DOI: 10.7717/peerj.5758
    Background: Secondhand smoke (SHS) exposure has adverse effects on the cardiovascular system. This study aimed to determine the effects of SHS on the cardiovascular disease biomarkers, namely the metabolic, inflammatory, and oxidative stress markers in healthy adult women.

    Methods: This comparative cross-sectional study was conducted among healthy women. The cases included those women exposed to SHS, and the controls included those women not exposed to SHS. SHS exposure was defined as being exposed to SHS for at least 15 min for 2 days per week. Venous blood was taken to measure the metabolic markers (high molecular weight adiponectin, insulin level, insulin resistance, and nonesterified fatty acids), oxidative stress markers (oxidized low density lipoprotein cholesterol and 8-isoprostane), and inflammatory markers (high-sensitivity C-reactive protein and interleukin-6). A hair nicotine analysis was also performed. An analysis of covariance and a simple linear regression analysis were conducted.

    Results: There were 101 women in the SHS exposure group and 91 women in the non-SHS exposure group. The mean (with standard deviation) of the hair nicotine levels was significantly higher in the SHS exposure group when compared to the non-SHS exposure group [0.22 (0.62) vs. 0.04 (0.11) ng/mg; P = 0.009]. No significant differences were observed in the high molecular weight adiponectin, insulin and insulin resistance, nonesterified fatty acids, 8-isoprostane, oxidized low density lipoprotein cholesterol, interleukin-6, and high-sensitivity C-reactive protein between the two groups. The serum high molecular weight adiponectin was negatively associated with the insulin level and insulin resistance in the women exposed to SHS. However, no significant relationships were seen between the high molecular weight adiponectin and nonesterified fatty acids, 8-isoprostane, oxidized low density lipoprotein cholesterol, high-sensitivity C-reactive protein in the SHS group.

    Discussion: There were no significant differences in the metabolic, oxidative stress, and inflammatory markers between the SHS exposure and non-SHS exposure healthy women. A low serum level of high molecular weight adiponectin was associated with an increased insulin level and resistance in the women exposed to SHS.

    Matched MeSH terms: Molecular Weight
  20. Rajamanikam A, Govind SK
    Parasit Vectors, 2013;6(1):295.
    PMID: 24499467 DOI: 10.1186/1756-3305-6-295
    Blastocystis spp. are one of the most prevalent parasites isolated from patients suffering from diarrhea, flatulence, constipation and vomiting. It's pathogenicity and pathophysiology remains controversial to date. Protease activity and amoebic forms have been reported previously in symptomatic isolates but there has been no conclusive evidence provided to correlate the protease activity and any specific life cycle stage of the parasite thus far.
    Matched MeSH terms: Molecular Weight
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