Browse publications by year: 2016

  1. Jafari S, Meng GY, Rajion MA, Jahromi MF, Ebrahimi M
    J Agric Food Chem, 2016 Jun 08;64(22):4522-30.
    PMID: 27192629 DOI: 10.1021/acs.jafc.6b00846
    Different solvents (hexane, chloroform, ethyl acetate, butanol, and water) were used to identify the effect of papaya leaf (PL) fractions (PLFs) on ruminal biohydrogenation (BH) and ruminal methanogenesis in an in vitro study. PLFs at a concentration of 0 (control, CON) and 15 mg/250 mg dry matter (DM) were mixed with 30 mL of buffered rumen fluid and were incubated for 24 h. Methane (CH4) production (mL/250 mg DM) was the highest (P < 0.05) for CON (7.65) and lowest for the chloroform fraction (5.41) compared to those of other PLFs at 24 h of incubation. Acetate to propionate ratio was the lowest for PLFs compared to that of CON. Supplementation of the diet with PLFs significantly (P < 0.05) decreased the rate of BH of C18:1n-9 (oleic acid; OA), C18:2n-6 (linoleic acid; LA), and C18:3n-3 (α-linolenic acid; LNA) compared to that of CON after 24 h of incubation. Real time PCR indicated that total protozoa and total methanogen population in PLFs decreased (P < 0.05) compared to those of CON.
    MeSH terms: Gastrointestinal Microbiome/drug effects*; Animals; Animal Feed/analysis; Bacteria/genetics; Bacteria/isolation & purification; Bacteria/metabolism*; Fatty Acids, Unsaturated/metabolism*; Fatty Acids, Unsaturated/chemistry; Fermentation; Goats/metabolism; Goats/microbiology; Hydrogenation; Methane/metabolism*; Plant Extracts/administration & dosage*; Rumen/microbiology*; Plant Leaves/chemistry; Dietary Supplements/analysis; Carica/chemistry*; Polyphenols/administration & dosage*
  2. Phan CW, Sabaratnam V, Bovicelli P, Righi G, Saso L
    Biofactors, 2016 Nov 12;42(6):591-599.
    PMID: 27193378 DOI: 10.1002/biof.1296
    Negletein has been shown to have therapeutic potential for inflammation-associated diseases, but its effect on neurite outgrowth is still unknown. The present study showed that negletein alone did not trigger PC12 cells to differentiate and extend neurites. When compared with the cells in the untreated control, a significant (P 
    MeSH terms: Animals; Cell Survival/drug effects; Drug Evaluation, Preclinical; Phosphorylation; Protein Processing, Post-Translational; Neurites/drug effects; Neurites/physiology*; PC12 Cells; Cyclic AMP Response Element-Binding Protein/metabolism; Neuroprotective Agents/pharmacology*; GAP-43 Protein/metabolism; Nerve Growth Factor/pharmacology; Nerve Growth Factor/physiology*; MAP Kinase Signaling System; Flavones/pharmacology*; Extracellular Signal-Regulated MAP Kinases/metabolism; Proto-Oncogene Proteins c-akt/metabolism; Rats
  3. Ngadiman NH, Mohd Yusof N, Idris A, Kurniawan D
    Proc Inst Mech Eng H, 2016 Aug;230(8):739-49.
    PMID: 27194535 DOI: 10.1177/0954411916649632
    Electrospinning is a simple and efficient process in producing nanofibers. To fabricate nanofibers made of a blend of two constituent materials, co-axial electrospinning method is an option. In this method, the constituent materials contained in separate barrels are simultaneously injected using two syringe nozzles arranged co-axially and the materials mix during the spraying process forming core and shell of the nanofibers. In this study, co-axial electrospinning method is used to fabricate nanofibers made of polyvinyl alcohol and maghemite (γ-Fe2O3). The concentration of polyvinyl alcohol and amount of maghemite nanoparticle loading were varied, at 5 and 10 w/v% and at 1-10 v/v%, respectively. The mechanical properties (strength and Young's modulus), porosity, and biocompatibility properties (contact angle and cell viability) of the electrospun mats were evaluated, with the same mats fabricated by regular single-nozzle electrospinning method as the control. The co-axial electrospinning method is able to fabricate the expected polyvinyl alcohol/maghemite nanofiber mats. It was noticed that the polyvinyl alcohol/maghemite electrospun mats have lower mechanical properties (i.e. strength and stiffness) and porosity, more hydrophilicity (i.e. lower contact angle), and similar cell viability compared to the mats fabricated by single-nozzle electrospinning method.
    MeSH terms: Biocompatible Materials/chemical synthesis; Biocompatible Materials/chemistry*; Biomechanical Phenomena; Cell Line; Cell Survival; Ferric Compounds/chemistry*; Humans; Materials Testing; Polyvinyl Alcohol/chemistry*; Nanotechnology/instrumentation; Nanofibers/ultrastructure; Nanofibers/chemistry
  4. Wijedasa LS
    Glob Chang Biol, 2016 09;22(9):2959.
    PMID: 27195773 DOI: 10.1111/gcb.13364
    MeSH terms: Carbon Dioxide; Fires*; Soil*
  5. Fong MY, Rashdi SA, Yusof R, Lau YL
    PLoS One, 2016;11(5):e0155627.
    PMID: 27195821 DOI: 10.1371/journal.pone.0155627
    BACKGROUND: Plasmodium knowlesi is a simian malaria parasite that has been reported to cause malaria in humans in Southeast Asia. This parasite invades the erythrocytes of humans and of its natural host, the macaque Macaca fascicularis, via interaction between the Duffy binding protein region II (PkDBPαRII) and the Duffy antigen receptor on the host erythrocytes. In contrast, the P. knowlesi gamma protein region II (PkγRII) is not involved in the invasion of P. knowlesi into humans. PkγRII, however, mediates the invasion of P. knowlesi into the erythrocytes of M. mulata, a non-natural host of P. knowlesi via a hitherto unknown receptor. The haplotypes of PkDBPαRII in P. knowlesi isolates from Peninsular Malaysia and North Borneo have been shown to be genetically distinct and geographically clustered. Also, the PkDBPαRII was observed to be undergoing purifying (negative) selection. The present study aimed to determine whether similar phenomena occur in PkγRII.

    METHODS: Blood samples from 78 knowlesi malaria patients were used. Forty-eight of the samples were from Peninsular Malaysia, and 30 were from Malaysia Borneo. The genomic DNA of the samples was extracted and used as template for the PCR amplification of the PkγRII. The PCR product was cloned and sequenced. The sequences obtained were analysed for genetic diversity and natural selection using MEGA6 and DnaSP (version 5.10.00) programmes. Genetic differentiation between the PkγRII of Peninsular Malaysia and North Borneo isolates was estimated using the Wright's FST fixation index in DnaSP (version 5.10.00). Haplotype analysis was carried out using the Median-Joining approach in NETWORK (version 4.6.1.3).

    RESULTS: A total of 78 PkγRII sequences was obtained. Comparative analysis showed that the PkγRII have similar range of haplotype (Hd) and nucleotide diversity (π) with that of PkDBPαRII. Other similarities between PkγRII and PkDBPαRII include undergoing purifying (negative) selection, geographical clustering of haplotypes, and high inter-population genetic differentiation (FST index). The main differences between PkγRII and PkDBPαRII include length polymorphism and no departure from neutrality (as measured by Tajima's D statistics) in the PkγRII.

    CONCLUSION: Despite the biological difference between PkγRII and PkDBPαRII, both generally have similar genetic diversity level, natural selection, geographical haplotype clustering and inter-population genetic differentiation index.

    MeSH terms: Algorithms; Animals; Antigens, Protozoan/genetics*; Borneo; Erythrocytes/parasitology; Genetics, Population; Geography; Haplotypes; Humans; Macaca fascicularis; Malaysia; Polymorphism, Genetic; Receptors, Cell Surface/genetics*; Selection, Genetic*; Genetic Variation*; Protozoan Proteins/genetics*; Cluster Analysis; Plasmodium knowlesi/genetics*; Sequence Analysis, DNA
  6. Manaf SM, Panneerchelvam S, Norazmi MN, Zafarina Z, Edinur HA
    Transfus Med, 2016 May 16.
    PMID: 27197082 DOI: 10.1111/tme.12315
  7. Bates T, Kennedy M, Diajil A, Goodson M, Thomson P, Doran E, et al.
    Cancer Epidemiol Biomarkers Prev, 2016 Jun;25(6):927-35.
    PMID: 27197272 DOI: 10.1158/1055-9965.EPI-15-0949
    BACKGROUND: Oral squamous cell carcinoma (OSCC) is a global healthcare problem associated with poor clinical outcomes. Early detection is key to improving patient survival. OSCC may be preceded by clinically recognizable lesions, termed oral potentially malignant disorders (OPMD). As histologic assessment of OPMD does not accurately predict their clinical behavior, biomarkers are required to detect cases at risk of malignant transformation. Epidermal growth factor receptor gene copy number (EGFR GCN) is a validated biomarker in lung non-small cell carcinoma. We examined EGFR GCN in OPMD and OSCC to determine its potential as a biomarker in oral carcinogenesis.

    METHODS: EGFR GCN was examined by in situ hybridization (ISH) in biopsies from 78 patients with OPMD and 92 patients with early-stage (stages I and II) OSCC. EGFR ISH signals were scored by two pathologists and a category assigned by consensus. The data were correlated with patient demographics and clinical outcomes.

    RESULTS: OPMD with abnormal EGFR GCN were more likely to undergo malignant transformation than diploid cases. EGFR genomic gain was detected in a quarter of early-stage OSCC, but did not correlate with clinical outcomes.

    CONCLUSION: These data suggest that abnormal EGFR GCN has clinical utility as a biomarker for the detection of OPMD destined to undergo malignant transformation. Prospective studies are required to verify this finding. It remains to be determined if EGFR GCN could be used to select patients for EGFR-targeted therapies.

    IMPACT: Abnormal EGFR GCN is a potential biomarker for identifying OPMD that are at risk of malignant transformation. Cancer Epidemiol Biomarkers Prev; 25(6); 927-35. ©2016 AACR.

    MeSH terms: Adult; Aged; Aged, 80 and over; Carcinoma, Squamous Cell/genetics; Carcinoma, Squamous Cell/metabolism*; Carcinoma, Squamous Cell/pathology; Female; Humans; Male; Middle Aged; Mouth Neoplasms/genetics; Mouth Neoplasms/metabolism*; ROC Curve; Biomarkers; Gene Dosage*; Carcinogenesis/genetics*; ErbB Receptors/genetics*
  8. Anantharaman D, Muller DC, Lagiou P, Ahrens W, Holcátová I, Merletti F, et al.
    Int J Epidemiol, 2016 Jun;45(3):752-61.
    PMID: 27197530 DOI: 10.1093/ije/dyw069
    BACKGROUND: Although smoking and HPV infection are recognized as important risk factors for oropharyngeal cancer, how their joint exposure impacts on oropharyngeal cancer risk is unclear. Specifically, whether smoking confers any additional risk to HPV-positive oropharyngeal cancer is not understood.

    METHODS: Using HPV serology as a marker of HPV-related cancer, we examined the interaction between smoking and HPV16 in 459 oropharyngeal (and 1445 oral cavity and laryngeal) cancer patients and 3024 control participants from two large European multi-centre studies. Odds ratios and credible intervals [CrI], adjusted for potential confounders, were estimated using Bayesian logistic regression.

    RESULTS: Both smoking [odds ratio (OR [CrI]: 6.82 [4.52, 10.29]) and HPV seropositivity (OR [CrI]: 235.69 [99.95, 555.74]) were independently associated with oropharyngeal cancer. The joint association of smoking and HPV seropositivity was consistent with that expected on the additive scale (synergy index [CrI]: 1.32 [0.51, 3.45]), suggesting they act as independent risk factors for oropharyngeal cancer.

    CONCLUSIONS: Smoking was consistently associated with increase in oropharyngeal cancer risk in models stratified by HPV16 seropositivity. In addition, we report that the prevalence of oropharyngeal cancer increases with smoking for both HPV16-positive and HPV16-negative persons. The impact of smoking on HPV16-positive oropharyngeal cancer highlights the continued need for smoking cessation programmes for primary prevention of head and neck cancer.

    MeSH terms: Adult; Aged; Antibodies, Viral/blood; Bayes Theorem; Enzyme-Linked Immunosorbent Assay; Europe; Female; Humans; Male; Middle Aged; Oropharyngeal Neoplasms/pathology*; Oropharyngeal Neoplasms/virology; Risk Factors; Logistic Models; Odds Ratio; Case-Control Studies; Papillomavirus Infections/complications*; Human papillomavirus 16*
  9. Al-Darraji HA, Altice FL, Kamarulzaman A
    Trop Med Int Health, 2016 Aug;21(8):1049-1058.
    PMID: 27197601 DOI: 10.1111/tmi.12726
    OBJECTIVES: To investigate the prevalence of previously undiagnosed active tuberculosis (TB) cases among prisoners in Malaysia's largest prison using an intensified TB case-finding strategy.

    METHODS: From October 2012 to May 2013, prisoners housed in two distinct units (HIV-negative and HIV-positive) were approached to participate in the TB screening study. Consenting prisoners submitted two sputum samples that were examined using GeneXpert MTB/RIF, smear microscopy and liquid culture. Socio-demographic and clinical information was collected and correlates of active TB, defined as having either a positive GeneXpert MTB/RIF or culture results, were assessed using regression analyses.

    RESULTS: Among the total of 559 prisoners, 442 (79.1%) had complete data; 28.7% were HIV-infected, 80.8% were men and the average age was 36.4 (SD 9.8) years. Overall, 34 (7.7%) had previously undiagnosed active TB, of whom 64.7% were unable to complete their TB treatment in prison due to insufficient time (<6 months) remaining in prison. Previously undiagnosed active TB was independently associated with older age groups (AOR 11.44 and 6.06 for age ≥ 50 and age 40-49 years, respectively) and with higher levels of immunosuppression (CD4 < 200 cells/ml) in HIV-infected prisoners (AOR 3.07, 95% CI 1.03-9.17).

    CONCLUSIONS: The high prevalence of previously undiagnosed active TB in this prison highlights the inadequate performance of internationally recommended case-finding strategies and suggests that passive case-finding policies should be abandoned, especially in prison settings where HIV infection is prevalent. Moreover, partnerships between criminal justice and public health treatment systems are crucial to continue TB treatment after release.

    MeSH terms: Criminal Law; HIV Seropositivity; Humans; Malaysia; Male; Microscopy; Prisoners; Prisons; Public Health; Regression Analysis; Sputum; Tuberculosis; HIV Infections; Prevalence
  10. Suraiya S, Semail N, Ismail MF, Abdullah JM
    Genome Announc, 2016;4(3).
    PMID: 27198011 DOI: 10.1128/genomeA.00323-16
    Mycobacterium tuberculosis is known to cause pulmonary and extrapulmonary tuberculosis. This organism showed special phylogeographical specificity. Here, we report the complete genome sequence of M. tuberculosis clinical isolate spoligotype SIT745/EAI1-MYS, which was isolated from a Malaysian tuberculosis patient.
    MeSH terms: Humans; Mycobacterium tuberculosis; Sensitivity and Specificity; Tuberculosis; Phylogeography
  11. Ong WJ, Tan LL, Ng YH, Yong ST, Chai SP
    Chem Rev, 2016 06 22;116(12):7159-329.
    PMID: 27199146 DOI: 10.1021/acs.chemrev.6b00075
    As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and "earth-abundant" nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The construction and characteristics of each classification of the heterojunction system will be critically reviewed, namely metal-g-C3N4, semiconductor-g-C3N4, isotype g-C3N4/g-C3N4, graphitic carbon-g-C3N4, conducting polymer-g-C3N4, sensitizer-g-C3N4, and multicomponent heterojunctions. The band structures, electronic properties, optical absorption, and interfacial charge transfer of g-C3N4-based heterostructured nanohybrids will also be theoretically discussed based on the first-principles density functional theory (DFT) calculations to provide insightful outlooks on the charge carrier dynamics. Apart from that, the advancement of the versatile photoredox applications toward artificial photosynthesis (water splitting and photofixation of CO2), environmental decontamination, and bacteria disinfection will be presented in detail. Last but not least, this comprehensive review will conclude with a summary and some invigorating perspectives on the challenges and future directions at the forefront of this research platform. It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g-C3N4-based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.
    MeSH terms: Graphite/chemistry*; Microscopy, Electron/methods; Nitriles/chemistry*; Photosynthesis*; Molecular Structure; Environmental Restoration and Remediation*
  12. Velayutham TS, Nguan HS, Ng BK, Gan WC, Manickam Achari V, Zahid NI, et al.
    Phys Chem Chem Phys, 2016 06 01;18(22):15182-90.
    PMID: 27199168 DOI: 10.1039/c6cp00583g
    The molecular dynamics of a synthetic branched chain glycolipid, 2-decyl-tetradecyl-β-d-maltoside (C14-10G2), in the dry assemblage of smectic and columnar liquid crystal phases has been studied by dielectric spectroscopy as a function of frequency and temperature during the cooling process. Strong relaxation modes were observed corresponding to the tilted smectic and columnar phases, respectively. At low frequency (∼900 Hz to 1 kHz) in the smectic phase, Process I* was observed due to the tilted sugar bilayer structure. The process continued in the columnar phase (Process I) with an abrupt dynamic change due to phase transition in the frequency range of ∼1.3 kHz to 22 kHz. An additional process (Process II) was observed in the columnar phase with a broader relaxation in the frequency range of ∼10 Hz to 1 kHz. A bias field dependence study was performed in the columnar phase and we found that the relaxation strength rapidly decreased with increased applied dc bias field. This relaxation originates from a collective motion of polar groups within the columns. The results of dielectric spectroscopy were supported by a molecular dynamics simulation study to identify the origin of the relaxation processes, which could be related to the chirality and hydrogen bonds of the sugar lipid.
    MeSH terms: Glycolipids/chemistry*; Hydrogen Bonding; Maltose/analogs & derivatives*; Maltose/chemistry; Temperature; Phase Transition; Liquid Crystals/chemistry; Molecular Dynamics Simulation*; Dielectric Spectroscopy
  13. Boonlue T, Subongkot S, Dilokthornsakul P, Kongsakon R, Pattanaprateep O, Suanchang O, et al.
    Clinicoecon Outcomes Res, 2016;8:127-36.
    PMID: 27199568 DOI: 10.2147/CEOR.S97300
    Several clinical practice guidelines suggest using atypical over typical antipsychotics in patients diagnosed with schizophrenia. Nevertheless, cost-containment policy urged restricting usage of atypical antipsychotics and switching from atypical to typical antipsychotics.
  14. Hang CY, Kitahashi T, Parhar IS
    Front Neuroanat, 2016;10:48.
    PMID: 27199680 DOI: 10.3389/fnana.2016.00048
    Biological impacts of light beyond vision, i.e., non-visual functions of light, signify the need to better understand light detection (or photoreception) systems in vertebrates. Photopigments, which comprise light-absorbing chromophores bound to a variety of G-protein coupled receptor opsins, are responsible for visual and non-visual photoreception. Non-visual opsin photopigments in the retina of mammals and extra-retinal tissues of non-mammals play an important role in non-image-forming functions of light, e.g., biological rhythms and seasonal reproduction. This review highlights the role of opsin photoreceptors in the deep brain, which could involve conserved neurochemical systems that control different time- and light-dependent physiologies in in non-mammalian vertebrates including teleost fish.
  15. Khaw YS, Chan YF, Jafar FL, Othman N, Chee HY
    Front Microbiol, 2016;7:543.
    PMID: 27199901 DOI: 10.3389/fmicb.2016.00543
    Human rhinovirus-C (HRV-C) has been implicated in more severe illnesses than HRV-A and HRV-B, however, the limited number of HRV-C complete genomes (complete 5' and 3' non-coding region and open reading frame sequences) has hindered the in-depth genetic study of this virus. This study aimed to sequence seven complete HRV-C genomes from Malaysia and compare their genetic characteristics with the 18 published HRV-Cs. Seven Malaysian HRV-C complete genomes were obtained with newly redesigned primers. The seven genomes were classified as HRV-C6, C12, C22, C23, C26, C42, and pat16 based on the VP4/VP2 and VP1 pairwise distance threshold classification. Five of the seven Malaysian isolates, namely, 3430-MY-10/C22, 8713-MY-10/C23, 8097-MY-11/C26, 1570-MY-10/C42, and 7383-MY-10/pat16 are the first newly sequenced complete HRV-C genomes. All seven Malaysian isolates genomes displayed nucleotide similarity of 63-81% among themselves and 63-96% with other HRV-Cs. Malaysian HRV-Cs had similar putative immunogenic sites, putative receptor utilization and potential antiviral sites as other HRV-Cs. The genomic features of Malaysian isolates were similar to those of other HRV-Cs. Negative selections were frequently detected in HRV-Cs complete coding sequences indicating that these sequences were under functional constraint. The present study showed that HRV-Cs from Malaysia have diverse genetic sequences but share conserved genomic features with other HRV-Cs. This genetic information could provide further aid in the understanding of HRV-C infection.
    MeSH terms: Antiviral Agents; Enterovirus; Exons; Heart Rate; Humans; Malaysia; Nucleotides; Rhinovirus; Open Reading Frames; Genomics
  16. Ching XT, Fong MY, Lau YL
    Front Microbiol, 2016;7:609.
    PMID: 27199938 DOI: 10.3389/fmicb.2016.00609
    Toxoplasmosis is a foodborne disease caused by Toxoplasma gondii, an obligate intracellular parasite. Severe symptoms occur in the immunocompromised patients and pregnant women leading to fatality and abortions respectively. Vaccination development is essential to control the disease. The T. gondii dense granule antigen 2 and 5 (GRA2 and GRA5) have been targeted in this study because these proteins are essential to the development of parasitophorous vacuole (PV), a specialized compartment formed within the infected host cell. PV is resistance to host cell endosomes and lysosomes thereby protecting the invaded parasite. Recombinant dense granular proteins, GRA2 (rGRA2) and GRA5 (rGRA5) were cloned, expressed, and purified in Escherichia coli, BL21 (DE3) pLysS. The potential of these purified antigens as subunit vaccine candidates against toxoplasmosis were evaluated through subcutaneous injection of BALB/c mice followed by immunological characterization (humoral- and cellular-mediated) and lethal challenge against virulent T. gondii RH strain in BALB/c mice. Results obtained demonstrated that rGRA2 and rGRA5 elicited humoral and cellular-mediated immunity in the mice. High level of IgG antibody was produced with the isotype IgG2a/IgG1 ratio of ≈0.87 (p < 0.001). Significant increase (p < 0.05) in the level of four cytokines (IFN-γ, IL-2, IL-4, and IL-10) was obtained. The antibody and cytokine results suggest that a mix mode of Th1/Th2-immunity was elicited with predominant Th1-immune response inducing partial protection against T. gondii acute infection in BALB/c mice. Our findings indicated that both GRA2 and GRA5 are potential candidates for vaccine development against T. gondii acute infection.
    MeSH terms: Animals; Antigens, Viral, Tumor; Escherichia coli; Female; Humans; Immunoglobulin G; Interleukin-2; Lysosomes; Mice, Inbred BALB C; Parasites; Pregnancy; Toxoplasma; Toxoplasmosis; Vacuoles; Interleukin-4; Cytokines; Interleukin-10; Immunocompromised Host; Vaccines, Subunit; Mice
  17. Teh SJ, Yeoh SL, Lee KM, Lai CW, Abdul Hamid SB, Thong KL
    PMID: 27203568 DOI: 10.1016/j.jphotobiol.2016.05.013
    The immobilization of photocatalyst nanoparticles on a solid substrate is an important aspect for improved post-treatment separation and photocatalyst reactor design. In this study, we report the simple preparation of reduced graphene oxide (rGO)-hybridized zinc oxide (ZnO) thin films using a one-step electrochemical deposition, and investigated the effect of rGO-hybridization on the photoinactivation efficiency of ZnO thin films towards Staphylococcus aureus (S. aureus) and Salmonella enterica serovar Typhi (S. Typhi) as target bacterial pathogens. Field-emission scanning electron microscopy (FESEM) revealed the formation of geometric, hexagonal flakes of ZnO on the ITO glass substrate, as well as the incorporation of rGO with ZnO in the rGO/ZnO thin film. Raman spectroscopy indicated the successful incorporation of rGO with ZnO during the electrodeposition process. Photoluminescence (PL) spectroscopy indicates that rGO hybridization with ZnO increases the amount of oxygen vacancies, evidenced by the shift of visible PL peak at 650 to 500nm. The photoinactivation experiments showed that the thin films were able to reduce the bacterial cell density of Staph. aureus and S. Typhi from an initial concentration of approximately 10(8) to 10(3)CFU/mL within 15min. The rGO/ZnO thin film increased the photoinactivation rate for S. aureus (log[N/No]) from -5.1 (ZnO) to -5.9. In contrast, the application of rGO/ZnO thin film towards the photoinactivation of S. Typhi did not improve its photoinactivation rate, compared to the ZnO thin film. We may summarise that (1) rGO/ZnO was effective to accelerate the photoinactivation of S. aureus but showed no difference to improve the photoinactivation of S. Typhi, in comparison to the performance of ZnO thin films, and (2) the photoinactivation in the presence of ZnO and rGO/ZnO was by ROS damage to the extracellular wall.
    MeSH terms: Graphite/chemistry*; Light; Microscopy, Electron, Scanning; Oxides/chemistry; Salmonella typhi/drug effects*; Salmonella typhi/radiation effects; Spectrum Analysis, Raman; Staphylococcus aureus/drug effects*; Staphylococcus aureus/radiation effects; Zinc Oxide/chemistry*; Reactive Oxygen Species/metabolism; Nanostructures/toxicity*; Nanostructures/chemistry
  18. Woon YL, Hor CP, Hussin N, Zakaria A, Goh PP, Cheah WK
    PLoS Negl Trop Dis, 2016 05;10(5):e0004575.
    PMID: 27203726 DOI: 10.1371/journal.pntd.0004575
    BACKGROUND: Dengue infection is the fastest spreading mosquito-borne viral disease, which affects people living in the tropical and subtropical countries. Malaysia had large dengue outbreaks in recent years. We aimed to study the demographics and clinical characteristics associated with dengue deaths in Malaysia.

    METHODS: We conducted a retrospective review on all dengue deaths that occurred nationwide between 1st January 2013 and 31st December 2014. Relevant data were extracted from mortality review reports and investigational forms. These cases were categorized into children (<15 years), adults (15-59 years) and elderly (≥60 years) to compare their clinical characteristics.

    RESULTS: A total of 322 dengue deaths were reviewed. Their mean age was 40.7±19.30 years, half were females and 72.5% were adults. The median durations of first medical contact, and hospitalization were 1 and 3 days, respectively. Diabetes and hypertension were common co-morbidities among adults and elderly. The most common warning signs reported were lethargy and vomiting, with lethargy (p = 0.038) being more common in children, while abdominal pain was observed more often in the adults (p = 0.040). But 22.4% did not have any warning signs. Only 34% were suspected of dengue illness at their initial presentation. More adults developed severe plasma leakage (p = 0.018). More than half (54%) suffered from multi-organ involvement, and 20.2% were free from any organ involvement. Dengue deaths occurred at the median of 3 days post-admission. Dengue shock syndrome (DSS) contributed to more than 70% of dengue deaths, followed by severe organ involvement (69%) and severe bleeding (29.7%).

    CONCLUSION: In Malaysia, dengue deaths occurred primarily in adult patients. DSS was the leading cause of death, regardless of age groups. The atypical presentation and dynamic progression of severe dengue in this cohort prompts early recognition and aggressive intervention to prevent deaths.

    TRIAL REGISTRATION: National Medical Research Registry (NMRR, NMRR-14-1374-23352).
    MeSH terms: Adolescent; Adult; Aged; Child; Child, Preschool; Demography; Dengue/diagnosis; Dengue/mortality*; Dengue/epidemiology*; Dengue/virology; Disease Outbreaks; Female; Hospitalization/statistics & numerical data; Humans; Malaysia/epidemiology; Male; Middle Aged; Pneumonia/mortality; Pneumonia/epidemiology; Pneumonia/virology; Retrospective Studies; Time Factors; Comorbidity; Severe Dengue/diagnosis; Severe Dengue/mortality*; Severe Dengue/epidemiology*; Severe Dengue/virology; Young Adult
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