Browse publications by year: 2015

  1. Enzymatic electrochemical detection of epidemic-causing Vibrio cholerae with a disposable oligonucleotide-modified screen-printed bisensor coupled to a dry-reagent-based nucleic acid amplification assay
    Yu CY, Ang GY, Chan KG, Banga Singh KK, Chan YY
    Biosens Bioelectron, 2015 Aug 15;70:282-8.
    PMID: 25835520 DOI: 10.1016/j.bios.2015.03.048
    In this study, we developed a nucleic acid-sensing platform in which a simple, dry-reagent-based nucleic acid amplification assay is combined with a portable multiplex electrochemical genosensor. Preparation of an amplification reaction mix targeting multiple DNA regions of interest is greatly simplified because the lyophilized reagents need only be reconstituted with ultrapure water before the DNA sample is added. The presence of single or multiple target DNAs causes the corresponding single-stranded DNA (ssDNA) amplicons to be generated and tagged with a fluorescein label. The fluorescein-labeled ssDNA amplicons are then analyzed using capture probe-modified screen-printed gold electrode bisensors. Enzymatic amplification of the hybridization event is achieved through the catalytic production of electroactive α-naphthol by anti-fluorescein-conjugated alkaline phosphatase. The applicability of this platform as a diagnostic tool is demonstrated with the detection of toxigenic Vibrio cholerae serogroups O1 and O139, which are associated with cholera epidemics and pandemics. The platform showed excellent diagnostic sensitivity and specificity (100%) when challenged with 168 spiked stool samples. The limit of detection was low (10 colony-forming units/ml) for both toxigenic V. cholerae serogroups. A heat stability assay revealed that the dry-reagent amplification reaction mix was stable at temperatures of 4-56 °C, with an estimated shelf life of seven months. The findings of this study highlight the potential of combining a dry-reagent-based nucleic acid amplification assay with an electrochemical genosensor in a more convenient, sensitive, and sequence-specific detection strategy for multiple target nucleic acids.
    MeSH terms: Disposable Equipment*; DNA, Bacterial/analysis; DNA, Bacterial/genetics*; DNA, Bacterial/chemistry; Equipment Design; Indicators and Reagents; Sensitivity and Specificity; Vibrio cholerae/genetics; Vibrio cholerae/isolation & purification*; Reproducibility of Results; Biosensing Techniques/instrumentation*; Polymerase Chain Reaction/methods*; Equipment Failure Analysis; Taq Polymerase/chemistry*
  2. Fulltext Transmission Networks of HIV-1 Among Men Who Have Sex With Men in East and Southeast Asia
    Tee KK, Kantor R, Sungkanuparph S, Takebe Y, Li P, Ditangco R, et al.
    J Acquir Immune Defic Syndr, 2015 Sep 01;70(1):e28-30.
    PMID: 25835606 DOI: 10.1097/QAI.0000000000000614
    MeSH terms: Asia, Southeastern/epidemiology; Far East/epidemiology; Humans; Male; HIV-1/classification; HIV-1/genetics; HIV-1/isolation & purification*; HIV Infections/epidemiology; HIV Infections/transmission*; HIV Infections/virology*; Cluster Analysis; Homosexuality, Male*
  3. Hybrid system up-flow constructed wetland integrated with microbial fuel cell for simultaneous wastewater treatment and electricity generation
    Oon YL, Ong SA, Ho LN, Wong YS, Oon YS, Lehl HK, et al.
    Bioresour Technol, 2015 Jun;186:270-5.
    PMID: 25836035 DOI: 10.1016/j.biortech.2015.03.014
    An innovative design of upflow constructed wetland-microbial fuel cell (UFCW-MFC) planted with cattail was used for simultaneous wastewater treatment and electricity generation. The electrodes material employed in the study was carbon felt. The main aim of this study is to assess the performance of the UFCW coupling with MFC in term of ability to treat wastewater and the capability to generate bioelectricity. The oxidation reduction potential (ORP) and dissolved oxygen (DO) profile showed that the anaerobic and aerobic regions were well developed in the lower and upper bed, respectively, of UFCW-MFC. Biodegradation of organic matter, nitrification and denitrification was investigated and the removal efficiencies of COD, NO3(-), NH4(+) were 100%, 40%, and 91%, respectively. The maximum power density of 6.12 mW m(-2) and coulombic efficiency of 8.6% were achieved at electrode spacing of anode 1 (A1) and cathode (15 cm).
    MeSH terms: Biodegradation, Environmental; Bioelectric Energy Sources*; Electrodes; Water Purification/methods*; Typhaceae/chemistry*; Wetlands*; Denitrification; Waste Water/chemistry*
  4. Rheological and fractal hydrodynamics of aerobic granules
    Tijani HI, Abdullah N, Yuzir A, Ujang Z
    Bioresour Technol, 2015 Jun;186:276-85.
    PMID: 25836036 DOI: 10.1016/j.biortech.2015.02.107
    The structural and hydrodynamic features for granules were characterized using settling experiments, predefined mathematical simulations and ImageJ-particle analyses. This study describes the rheological characterization of these biologically immobilized aggregates under non-Newtonian flows. The second order dimensional analysis defined as D2=1.795 for native clusters and D2=1.099 for dewatered clusters and a characteristic three-dimensional fractal dimension of 2.46 depicts that these relatively porous and differentially permeable fractals had a structural configuration in close proximity with that described for a compact sphere formed via cluster-cluster aggregation. The three-dimensional fractal dimension calculated via settling-fractal correlation, U∝l(D) to characterize immobilized granules validates the quantitative measurements used for describing its structural integrity and aggregate complexity. These results suggest that scaling relationships based on fractal geometry are vital for quantifying the effects of different laminar conditions on the aggregates' morphology and characteristics such as density, porosity, and projected surface area.
    MeSH terms: Bacteria, Aerobic/metabolism*; Computer Simulation; Flocculation; Plant Oils; Rheology; Fractals; Biofilms*; Water Purification/methods*; Cells, Immobilized/metabolism*; Hydrodynamics; Waste Water/chemistry*
  5. Thermo-responsive adsorbent for size-selective protein adsorption
    Lee MF, Chan ES, Tam KC, Tey BT
    J Chromatogr A, 2015 May 15;1394:71-80.
    PMID: 25836051 DOI: 10.1016/j.chroma.2015.03.034
    A thermo-responsive random copolymer, POEGMA (poly(oligoethylene glycol) methacrylate) grafted on cationized agarose adsorbent was used for size selective protein adsorption. The effects of OEGMA300 ((oligoethylene glycol) methyl ether methacrylate, Mn=300g/mol) content and temperature on the adsorption of bovine serum albumin (BSA) were evaluated. Increasing the content of OEGMA300 resulted a reduction in BSA adsorption due to the enhanced shielding effect of OEGMA300 chains. Grafting of POEGMA chains onto cationized agarose adsorbent reduced the BSA adsorption by more than 95% at 26.5°C, which is below the LCST (lower critical solution temperature) of POEGMA. The BSA adsorption capacities for adsorbents grafted with 10 and 20mol% of OEGMA300 decreased by 48% and 46% respectively at 38°C, a temperature higher than their LCSTs. The temperature-dependent adsorption of BSA on the adsorbents was attributed to changes in the polymer conformation. The thermal transition of grafted POEGMA conformation exposed the ligand when the temperature was increased. Myoglobin (Myo), which was smaller than BSA, its adsorption behavior was less dependent on the polymer conformation. The adsorption of myoglobin onto the adsorbent with and without POEGMA showed similar percentage of reduction whereas the adsorption of BSA onto the adsorbent with POEGMA decreased by 7.6 times compared to the one without POEGMA. The packed bed of POEGMA grafted adsorbent was used for flow through separation of a protein mixture consisted of virus-like particle, Hepatitis B virus-like particle (HBVLP), BSA and insulin aspart. The recovery of HBVLP in 20mol% of OEGMA300 grafted adsorbent was increased by 19% compared to ungrafted adsorbent. The flow through of BSA can be reduced by increasing the operating temperature above LCST of 20mol% of OEGMA300 while the smaller protein, insulin aspart, remained adsorbed onto the cationized surface. Hence, this thermo-responsive adsorbent has a potential for size-selective separation of protein especially for the recovery of large biomolecule.
    MeSH terms: Adsorption; Hepatitis B virus/chemistry; Methacrylates/chemistry*; Myoglobin/chemistry; Polyethylene Glycols/chemistry*; Proteins/chemistry*; Serum Albumin, Bovine/chemistry; Solutions; Temperature; Virion/chemistry; Insulin Aspart/chemistry
  6. Fulltext Factors affecting dengue prevention practices: nationwide survey of the Malaysian public
    Wong LP, Shakir SM, Atefi N, AbuBakar S
    PLoS One, 2015;10(4):e0122890.
    PMID: 25836366 DOI: 10.1371/journal.pone.0122890
    Efforts to stamp dengue in many dengue endemic countries has met little success. There is a need to re-examine and understand how the public at large view the dengue prevention efforts. This study aimed to examine the demographic factors, theoretical constructs of the Health Belief Model and knowledge about dengue and how these influence the practice of dengue prevention.
    MeSH terms: Adult; Animals; Demography; Dengue/epidemiology*; Dengue/prevention & control*; Female; Humans; Health Knowledge, Attitudes, Practice*; Malaysia/epidemiology; Male; Middle Aged; Models, Psychological*; Culicidae/physiology; Population Density; Multivariate Analysis; Linear Models; Disease Transmission, Infectious/prevention & control*
  7. Ultrasonic extraction of anthocyanin from Clitoria ternatea flowers using response surface methodology
    Chong FC, Gwee XF
    Nat Prod Res, 2015;29(15):1485-7.
    PMID: 25836369 DOI: 10.1080/14786419.2015.1027892
    The ultrasonic extraction (UE) method of anthocyanin from Clitoria ternatea flowers using response surface methodology (RSM) was performed in this study. By using RSM, the objective is to optimise the extraction yield of anthocyanin from C. ternatea which is influenced by various factors, including the extraction temperature, time, ratio of solvent to solid and ultrasonic power. The empirical model was investigated by performing first-level optimisation in a two-level factorial design with Design Expert 7 software. In comparison with the conventional solvent extraction, UE showed a 246.48% better extraction yield and produced an anthocyanin extract with a radical scavenging activity of 68.48% at the optimised factors of 50°C, 150 min, 15 mL/g and 240 W.
    MeSH terms: Anthocyanins/isolation & purification*; Plant Extracts/chemistry*; Solvents; Temperature; Ultrasonics/methods*; Clitoria/chemistry*; Flowers/chemistry*
  8. Fulltext Relationship between trusting behaviors and psychometrics associated with social network and depression among young generation: a pilot study
    Watabe M, Kato TA, Teo AR, Horikawa H, Tateno M, Hayakawa K, et al.
    PLoS One, 2015;10(3):e0120183.
    PMID: 25836972 DOI: 10.1371/journal.pone.0120183
    Maladaptive social interaction and its related psychopathology have been highlighted in psychiatry especially among younger generations. In Japan, novel expressive forms of psychiatric phenomena such as "modern-type depression" and "hikikomori" (a syndrome of severe social withdrawal lasting for at least six months) have been reported especially among young people. Economic games such as the trust game have been utilized to evaluate real-world interpersonal relationships as a novel candidate for psychiatric evaluations. To investigate the relationship between trusting behaviors and various psychometric scales, we conducted a trust game experiment with eighty-one Japanese university students as a pilot study. Participants made a risky financial decision about whether to trust each of 40 photographed partners. Participants then answered a set of questionnaires with seven scales including the Lubben Social Network Scale (LSNS)-6 and the Patient Health Questionnaire (PHQ)-9. Consistent with previous research, male participants trusted partners more than female participants. Regression analysis revealed that LSNS-family (perceived support from family) for male participants, and item 8 of PHQ-9 (subjective agitation and/or retardation) for female participants were associated with participants' trusting behaviors. Consistent with claims by social scientists, our data suggest that, for males, support from family was negatively associated with cooperative behavior toward non-family members. Females with higher subjective agitation (and/or retardation) gave less money toward males and high attractive females, but not toward low attractive females in interpersonal relationships. We believe that our data indicate the possible impact of economic games in psychiatric research and clinical practice, and validation in clinical samples including modern-type depression and hikikomori should be investigated.
    MeSH terms: Adolescent; Adult; Age Factors; Analysis of Variance; Depression/etiology*; Depression/epidemiology*; Female; Games, Experimental; Humans; Interpersonal Relations*; Japan/epidemiology; Male; Pilot Projects; Psychometrics*; Surveys and Questionnaires; Trust*; Young Adult
  9. Cost-Effectiveness Analysis of Fondaparinux vs Enoxaparin in Non-ST Elevation Acute Coronary Syndrome in Thailand
    Permsuwan U, Chaiyakunapruk N, Nathisuwan S, Sukonthasarn A
    Heart Lung Circ, 2015 Sep;24(9):860-8.
    PMID: 25837019 DOI: 10.1016/j.hlc.2015.02.018
    Non-ST elevation acute coronary syndrome (NSTE-ACS) imposes a significant health and economic burden on a society. Anticoagulants are recommended as standard therapy by various clinical practice guidelines. Fondaparinux was introduced and evaluated in a number of large randomised, controlled trials. This study therefore aimed to determine the cost-effectiveness of fondaparinux versus enoxaparin in the treatment of NSTE-ACS in Thailand.
    MeSH terms: Aged; Costs and Cost Analysis; Female; Humans; Male; Middle Aged; Thailand; Models, Economic*; Acute Coronary Syndrome/drug therapy*; Acute Coronary Syndrome/economics*
  10. A facile enzymatic synthesis of geranyl propionate by physically adsorbed Candida rugosa lipase onto multi-walled carbon nanotubes
    Mohamad NR, Buang NA, Mahat NA, Lok YY, Huyop F, Aboul-Enein HY, et al.
    Enzyme Microb Technol, 2015 May;72:49-55.
    PMID: 25837507 DOI: 10.1016/j.enzmictec.2015.02.007
    In view of several disadvantages as well as adverse effects associated with the use of chemical processes for producing esters, alternative techniques such as the utilization of enzymes on multi-walled carbon nanotubes (MWCNTs), have been suggested. In this study, the oxidative MWCNTs prepared using a mixture of HNO3 and H2SO4 (1:3 v/v) were used as a supportive material for the immobilization of Candida rugosa lipase (CRL) through physical adsorption process. The resulting CRL-MWCNTs biocatalysts were utilized for synthesizing geranyl propionate, an important ester for flavoring agent as well as in fragrances. Enzymatic esterification of geraniol with propionic acid was carried out using heptane as a solvent and the efficiency of CRL-MWCNTs as a biocatalyst was compared with the free CRL, considering the incubation time, temperature, molar ratio of acid:alcohol, presence of desiccant as well as its reusability. It was found that the CRL-MWCNTs resulted in a 2-fold improvement in the percentage of conversion of geranyl propionate when compared with the free CRL, demonstrating the highest yield of geranyl propionate at 6h at 55°C, molar ratio acid: alcohol of 1:5 and with the presence of 1.0g desiccant. It was evident that the CRL-MWCNTs biocatalyst could be reused for up to 6 times before a 50% reduction in catalytic efficiency was observed. Hence, it appears that the facile physical adsorption of CRL onto F-MWCNTs has improved the activity and stability of CRL as well as served as an alternative method for the synthesis of geranyl propionate.
    MeSH terms: Adsorption; Biotechnology; Candida/enzymology*; Desiccation; Enzymes, Immobilized/metabolism; Esterification; Fungal Proteins/metabolism*; Lipase/metabolism*; Propionates/metabolism*; Temperature; Spectroscopy, Fourier Transform Infrared; Nanotubes, Carbon/ultrastructure; Microscopy, Electron, Transmission; Biocatalysis
  11. Fulltext Psychosis post corona radiata and lentiform nucleus infarction
    Abdullah KH, Saini SM, Sharip S, Rahman AH
    BMJ Case Rep, 2015 Apr 02;2015.
    PMID: 25837653 DOI: 10.1136/bcr-2014-208954
    Complications of stroke can include neuropsychiatric symptoms. However, post-stroke psychosis is rare. We report a case where an acute presentation of psychosis, depression and fluctuating cognitive impairment in a middle-aged man turned out to be related to a silent brain infarction. The patient had a background of poorly controlled type 2 diabetes mellitus with glycated haemoglobin level of 9.0-11.0%, hypertension and ischaemic heart disease. His CT brain results showed multifocal infarct with hypodensities at bilateral lentiform nucleus and bilateral corona radiata. His strong genetic predisposition of psychosis and a history of brief psychotic disorder with complete remission 3 years prior to the current presentation might possibly contribute to his post-stroke atypical neuropsychiatric presentation, and posed diagnostic challenges. He showed marked improvement with risperidone 6 mg nocte, chlorpromazine 50 mg nocte and fluvoxamine of 200 mg nocte. The need of comprehensive treatments to modify his stroke risk factors was addressed.
    MeSH terms: Cognition Disorders/etiology; Corpus Striatum/blood supply*; Corpus Striatum/pathology; Depression/etiology; Diagnosis, Differential; Humans; Infarction/psychology*; Male; Middle Aged; Psychotic Disorders/diagnosis; Psychotic Disorders/etiology*; Stroke/psychology*
  12. Fulltext In vitro evaluation of bioactivity of chemically deposited hydroxyapatite on polyether ether ketone
    Almasi D, Izman S, Sadeghi M, Iqbal N, Roozbahani F, Krishnamurithy G, et al.
    Int J Biomater, 2015;2015:475435.
    PMID: 25838826 DOI: 10.1155/2015/475435
    Polyether ether ketone (PEEK) is considered the best alternative material for titanium for spinal fusion cage implants due to its low elasticity modulus and radiolucent property. The main problem of PEEK is its bioinert properties. Coating with hydroxyapatite (HA) showed very good improvement in bioactivity of the PEEK implants. However the existing methods for deposition of HA have some disadvantages and damage the PEEK substrate. In our previous study a new method for deposition of HA on PEEK was presented. In this study cell proliferation of mesenchymal stem cell and apatite formation in simulated body fluid (SBF) tests were conducted to probe the effect of this new method in improvement of the bioactivity of PEEK. The mesenchymal stem cell proliferation result showed better cells proliferation on the treated layer in comparison with untreated PEEK. The apatite formation results showed the growth of the HA on the treated PEEK but there was not any sight of the growth of HA on the untreated PEEK even after 2 weeks. The results showed the new method of the HA deposition improved the bioactivity of the treated PEEK in comparison with the bare PEEK.
  13. Fulltext A prospective study of tuberculosis drug susceptibility in Sabah, Malaysia, and an algorithm for management of isoniazid resistance
    Rashid Ali MR, Parameswaran U, William T, Bird E, Wilkes CS, Lee WK, et al.
    J Trop Med, 2015;2015:261925.
    PMID: 25838829 DOI: 10.1155/2015/261925
    Introduction. The burden of tuberculosis is high in eastern Malaysia, and rates of Mycobacterium tuberculosis drug resistance are poorly defined. Our objectives were to determine M. tuberculosis susceptibility and document management after receipt of susceptibility results.
    Methods. Prospective study of adult outpatients with smear-positive pulmonary tuberculosis (PTB) in Sabah, Malaysia. Additionally, hospital clinicians accessed the reference laboratory for clinical purposes during the study.
    Results. 176 outpatients were enrolled; 173 provided sputum samples. Mycobacterial culture yielded M. tuberculosis in 159 (91.9%) and nontuberculous Mycobacterium (NTM) in three (1.7%). Among outpatients there were no instances of multidrug resistant M. tuberculosis (MDR-TB). Seven people (4.5%) had isoniazid resistance (INH-R); all were switched to an appropriate second-line regimen for varying durations (4.5-9 months). Median delay to commencement of the second-line regimen was 13 weeks. Among 15 inpatients with suspected TB, 2 had multidrug resistant TB (one extensively drug resistant), 2 had INH-R, and 4 had NTM.
    Conclusions. Current community rates of MDR-TB in Sabah are low. However, INH-resistance poses challenges, and NTM is an important differential diagnosis in this setting, where smear microscopy is the usual diagnostic modality. To address INH-R management issues in our setting, we propose an algorithm for the treatment of isoniazid-resistant PTB.
    Study site: Tuberculosis clinic, Klinik Kesihatan Luyang, Kota Kinabalu, Sabah, Malaysia
    MeSH terms: Ambulatory Care Facilities; Humans; Malaysia; Outpatient Clinics, Hospital; Tuberculosis*; Cohort Studies; Drug Resistance, Bacterial*
  14. Fulltext The physicochemical properties of microwave-assisted encapsulated anthocyanins from Ipomoea batatas as affected by different wall materials
    Mohd Nawi N, Muhamad II, Mohd Marsin A
    Food Sci Nutr, 2015 Mar;3(2):91-9.
    PMID: 25838887 DOI: 10.1002/fsn3.132
    This study focuses on the impact of different wall materials on the physicochemical properties of microwave-assisted encapsulated anthocyanins from Ipomoea batatas. Using the powder characterization technique, purple sweet potato anthocyanin (PSPAs) powders were analysed for moisture content, water activity, dissolution time, hygroscopicity, color and morphology. PSPAs were produced using different wall materials: maltodextrin (MD), gum arabic (GA) and a combination of gum arabic and maltodextrin (GA + MD) at a 1:1 ratio. Each of the wall materials was homogenized to the core material at a core/wall material ratio of 5 and were microencapsulated by microwave-assisted drying at 1100 W. Results indicated that encapsulated powder with the GA and MD combination presented better quality of powder with the lowest value of moisture content and water activity. With respect to morphology, the microcapsule encapsulated with GA + MD showed several dents in coating surrounding its core material, whereas other encapsulated powders showed small or slight dents entrapped onto the bioactive compound. Colorimetric analysis showed changes in values of L, a*, b*, hue and chroma in the reconstituted powder compared to the initial powder.
    MeSH terms: Anthocyanins; Capsules; Color; Colorimetry; Desiccation; Excipients; Gum Arabic; Microwaves; Polysaccharides; Powders; Solubility; Water; Wettability; Ipomoea batatas
  15. Fulltext Impact of source tissue and ex vivo expansion on the characterization of goat mesenchymal stem cells
    Mohamad-Fauzi N, Ross PJ, Maga EA, Murray JD
    J Anim Sci Biotechnol, 2015;6(1):1.
    PMID: 25838897 DOI: 10.1186/2049-1891-6-1
    There is considerable interest in using goats as models for genetically engineering dairy animals and also for using stem cells as therapeutics for bone and cartilage repair. Mesenchymal stem cells (MSCs) have been isolated and characterized from various species, but are poorly characterized in goats.
  16. Fulltext Validity and reliability of the hausa version of multidimensional scale of perceived social support index
    Mohammad AH, Al Sadat N, Loh SY, Chinna K
    Iran Red Crescent Med J, 2015 Feb;17(2):e18776.
    PMID: 25838933 DOI: 10.5812/ircmj.18776
    BACKGROUND: Social support has been identified as one of the key factors for enhancing the quality of life after stroke. However, a scientific tool that is valid for evaluating social support among stroke survivors in Nigeria has not been developed so far.

    OBJECTIVES: The objective of this study was to examine the psychometric properties of the Hausa translated versions of the Multidimensional Scale of Perceived Social Support (MSPSS) and to validate it for future use in clinical research in Nigeria.

    PATIENTS AND METHODS: This cross-sectional study was conducted on a sample of 140 adult stroke survivors attending rehabilitation services at stroke referral centers in Kano, Nigeria. The psychometric analysis of the Hausa-MSPSS involved face, content, criterion and construct validity tests, as well as internal and test-retest reliability. Confirmatory factor analysis was performed to assess validity of the three-factor (Family, Friends and Significant others) model for the Hausa-MSPSS.

    RESULTS: Based on expert panel, clinicians' review and patients' feedback, the 12 item Hausa-MSPSS had sufficient face, content and criterion validity. In reliability analysis, the Cronbach's alpha was 0.781. In test-retest reliability analysis, the minimum kappa value was 0.673. In Confirmatory factor analysis, the three-factor model was not acceptable. An alternative two-factor model with Family and Friends, as the two domain was found to be acceptable (Chi-square/df < 3, TLI, CFI > 0.9, RMSEA < 0.08). The average variances extracted for the two constructs were 0.5 and 0.7, respectively. The R-squared value between the two constructs was 0.397. Cross validity tested using 1000 bootstrap resamples gave satisfactory results (P = 0.079).

    CONCLUSIONS: The 11 item Hausa-MSPSS index is valid for the assessment of perceived social support among stroke survivors in Nigeria.

  17. Fulltext Solubility enhancement studies on lurasidone hydrochloride using mixed hydrotropy
    Madan JR, Pawar KT, Dua K
    Int J Pharm Investig, 2015 Apr-Jun;5(2):114-20.
    PMID: 25838997 DOI: 10.4103/2230-973X.153390
    Low aqueous solubility is a major problem faced during formulation development of new drug molecules. Lurasidone HCl (LRD) is an antipsychotic agent specially used in the treatments of schizophrenia and is a good example of the problems associated with low aqueous solubility. Lurasidone is practically insoluble in water, has poor bioavailability and slow onset of action and therefore cannot be given in emergency clinical situations like schizophrenia. Hence, purpose of this research was to provide a fast dissolving oral dosage form of Lurasidone. This dosage form can provide quick onset of action by using the concept of mixed hydrotropy. Initially, solubility of LRD was determined individually in nicotinamide, sodium citrate, urea and sodium benzoate at concentration of 10, 20, 30 and 40% w/v solutions using purified water as a solvent. Highest solubility was obtained in 40% sodium benzoate solution. In order to decrease the individual hydrotrope concentration mixed hydrotropic agents were used. Highest solubility was obtained in 15:20:5 ratio of Nicotinamide + sodium benzoate + sodium citrate. This optimized combination was utilized in the preparation of solid dispersions by using distilled water as a solvent. Solid dispersions were evaluated for X-ray diffraction, differential scanning calorimetry and Fourier-transform infrared to show no drug-hydrotropes interaction has occurred. This solid dispersion was compressed to form fast dissolving tablets. Dissolution studies of prepared tablets were done using USP Type II apparatus. The batch L3 tablets show 88% cumulative drug release within 14 min and in vitro dispersion time was 32 min. It was concluded that the concept of mixed hydrotropic solid dispersion is novel, safe and cost-effective technique for enhancing the bioavailability of poorly water-soluble drugs. The miraculous enhancement in solubility and bioavailability of Lurasidone is clear indication of the potential of mixed hydrotropy to be used in future for other poorly water-soluble drugs in which low bioavailability is a major concern.
    MeSH terms: Lurasidone Hydrochloride; Benzoates; Biological Availability; Calorimetry, Differential Scanning; Citrates; Niacin; Niacinamide; Schizophrenia; Solubility; Solvents; Tablets; Antipsychotic Agents; Urea; Water; X-Ray Diffraction; Citric Acid; Sodium Benzoate; Drug Liberation
  18. Small circular single stranded DNA viral genomes in unexplained cases of human encephalitis, diarrhea, and in untreated sewage
    Phan TG, Mori D, Deng X, Rajindrajith S, Ranawaka U, Fan Ng TF, et al.
    Virology, 2015 Aug;482:98-104.
    PMID: 25839169 DOI: 10.1016/j.virol.2015.03.011
    Viruses with small circular ssDNA genomes encoding a replication initiator protein can infect a wide range of eukaryotic organisms ranging from mammals to fungi. The genomes of two such viruses, a cyclovirus (CyCV-SL) and gemycircularvirus (GemyCV-SL) were detected by deep sequencing of the cerebrospinal fluids of Sri Lankan patients with unexplained encephalitis. One and three out of 201 CSF samples (1.5%) from unexplained encephalitis patients tested by PCR were CyCV-SL and GemyCV-SL DNA positive respectively. Nucleotide similarity searches of pre-existing metagenomics datasets revealed closely related genomes in feces from unexplained cases of diarrhea from Nicaragua and Brazil and in untreated sewage from Nepal. Whether the tropism of the cyclovirus and gemycircularvirus reported here include humans or other cellular sources in or on the human body remains to be determined.
    MeSH terms: Adolescent; Adult; Aged; Brazil; Cerebrospinal Fluid/virology; Child; Child, Preschool; Diarrhea/virology*; DNA, Circular/genetics*; DNA, Circular/isolation & purification; DNA, Single-Stranded/genetics*; DNA, Single-Stranded/isolation & purification; Encephalitis/virology*; Feces/virology; Female; Humans; Infant; Male; Middle Aged; Molecular Sequence Data; Nicaragua; Phylogeny; Sewage/virology*; Sri Lanka; Cluster Analysis; Polymerase Chain Reaction; Genome, Viral*; Sequence Homology; Sequence Analysis, DNA; Circoviridae/genetics; Circoviridae/isolation & purification*; Young Adult; High-Throughput Nucleotide Sequencing
  19. Effect of acid hydrolysis on regenerated kenaf core membrane produced using aqueous alkaline-urea systems
    Padzil FN, Zakaria S, Chia CH, Jaafar SN, Kaco H, Gan S, et al.
    Carbohydr Polym, 2015 Jun 25;124:164-71.
    PMID: 25839807 DOI: 10.1016/j.carbpol.2015.02.013
    Bleached kenaf core pulps (BKC) were hydrolyzed in H2SO4 (0.5M) at different time (0min to 90min) at room temperature. After the hydrolysis process, the viscosity average molecular weight (Mŋ) for BKC sample has reduced from 14.5×10(4) to 2.55×10(4). The hydrolyzed BKC was then dissolved in NaOH:urea:water and in LiOH:urea:water mixed solvent at the ratio of 7:12:81 and 4.6:15:80.4, respectively. The increased in hydrolysis time has decreased Mŋ of cellulose leading to easy dissolution process. Higher porosity and transparency with lower crystallinity index (CrI) of regenerated membrane produced can be achieved as the Mŋ reduced. The properties of membrane were observed through FESEM, UV-vis spectrophotometer and XRD. This study has proven that acid hydrolysis has reduced the Mŋ of cellulose, thus, enhanced the properties of regenerated membrane produced with assisted by alkaline/urea system.
    MeSH terms: Cellulose/chemistry*; Crystallization; Hydrolysis; Molecular Weight; Sodium Hydroxide/chemistry*; Solubility; Sulfuric Acids/chemistry*; Temperature; Time Factors; Urea/chemistry*; Viscosity; Water/chemistry; X-Ray Diffraction; Porosity; Lithium Compounds/chemistry; Hibiscus/chemistry*
  20. Electrical, structural, thermal and electrochemical properties of corn starch-based biopolymer electrolytes
    Liew CW, Ramesh S
    Carbohydr Polym, 2015 Jun 25;124:222-8.
    PMID: 25839815 DOI: 10.1016/j.carbpol.2015.02.024
    Biopolymer electrolytes containing corn starch, lithium hexafluorophosphate (LiPF6) and ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) are prepared by solution casting technique. Temperature dependence-ionic conductivity studies reveal Vogel-Tamman-Fulcher (VTF) relationship which is associated with free volume theory. Ionic liquid-based biopolymer electrolytes show lower glass transition temperature (Tg) than ionic liquid-free biopolymer electrolyte. X-ray diffraction (XRD) studies demonstrate higher amorphous region of ionic liquid-added biopolymer electrolytes. In addition, the potential stability window of the biopolymer electrolyte becomes wider and stable up to 2.9V. Conclusively, the fabricated electric double layer capacitor (EDLC) shows improved electrochemical performance upon addition of ionic liquid into the biopolymer electrolyte. The specific capacitance of EDLC based on ionic liquid-added polymer electrolyte is relatively higher than that of ionic liquid-free polymer electrolyte as depicted in cyclic voltammogram.
    MeSH terms: Biopolymers/chemistry*; Calorimetry, Differential Scanning; Zea mays/metabolism; Zea mays/chemistry*; Electric Conductivity; Electrolytes/chemistry*; Imidazoles/chemistry; Starch/chemistry*; Transition Temperature; Ionic Liquids/chemistry; Electrochemical Techniques
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