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In vitro invasion inhibition assay using antibodies against Plasmodium knowlesi Duffy binding protein alpha and apical membrane antigen protein 1 in human erythrocyte-adapted P. knowlesi A1-H.1 strain
No full textBackground: The rapid process of malaria erythrocyte invasion involves ligand-receptor interactions. Inducing antibodies against specific ligands or receptors that abrogate the invasion process is a key challenge for blood stage vaccine development. However, few candidates were reported and remain to be validated for the discovery of new vaccine candidates in Plasmodium knowlesi. Methods: In order to investigate the efficacy of pre-clinical vaccine candidates in P. knowlesi-infected human cases, this study describes an in vitro invasion inhibition assay, using a P. knowlesi strain adapted to in vitro growth in human erythrocytes, PkA1-H.1. Recombinant proteins of P. knowlesi Duffy binding protein alpha (PkDBPα) and apical membrane antigen 1 (PkAMA1) were produced in Escherichia coli system and rabbit antibodies were generated from immune animals. Results: PkDBPα and PkAMA1 recombinant proteins were expressed as insoluble and produced as a functional refolded form for this study. Antibodies against PkDBPα and PkAMA1 specifically recognized recombinant proteins and native parasite proteins in schizont-stage parasites on the merozoite organelles. Single and combination of anti-PkDBPα and anti-PkAMA1 antibodies elicited strong growth inhibitory effects on the parasite in concentration-dependent manner. Meanwhile, IgG prevalence of PkDBPα and PkAMA1 were observed in 13.0 and 46.7% in human clinical patients, respectively. Conclusion: These data provide support for the validation of in vitro growth inhibition assay using antibodies of DBPα and AMA1 in human-adapted P. knowlesi parasite PkA1-H.1 strain
Impact of educational outreach intervention on enhancing health care providers' knowledge about statin therapy prescribing in Malaysian patients with type 2 diabetes mellitus
No full textRationale: Previous research reported underutilization of statin therapy among patients with type 2 diabetes mellitus. Improving health care providers' awareness and understanding of the benefits and risks of statin treatment could be of assistance in optimizing the statin prescribing process. Aims and Objectives: This study aimed to assess health care providers' knowledge related to statin therapy and the impact of educational outreach intervention based on the perceived knowledge. Methods: This was a cross-sectional study based on educational outreach intervention targeting physicians and pharmacists in 1 major tertiary hospital in the state of Pahang, Malaysia. Participants responded to a 12-item, validated questionnaire both prior to and after the outreach educational program. Two sessions were conducted separately for 2 cohorts of pharmacists and physicians. The knowledge scores prior to and after the educational intervention were calculated and compared using a paired-samples t-test. Results: The response rate to both pre-and post-educational outreach questionnaires was 91% (40/44). Prior to the intervention, around 84% (n37) of the participants decided to initiate statin therapy for both pre-assessment clinical case scenarios; however, only 27% (n12) could state the clinical benefits of statin therapy. Forty-five percent (n20) could state the drug to drug interactions, and 52.3% (n23) could identify the statin therapy that can be given at any time day/evening. The educational outreach program increased participants' knowledge scores of 1.450 (95% CI, 0.918 to 1.982) point, P <.0005, which is statistically significant. Forty respondents (91%) were of the opinion that statin side effects are the most common cause of treatment discontinuation. Conclusion: This work demonstrated the impact of an educational outreach intervention on improving health care providers' knowledge and beliefs about statin therapy. This type of intervention is considered effective for short-term knowledge enhancement. Further research is needed to test the long-term efficacy of such intervention
Heat Transfer of a non-Newtonian MHD boundary layer fluid flow with active and passive controls of nanoparticles
No full textIn this paper, active and passive controls of nanoparticles in a Sisko fluid flow are considered. An external magnetic force is applied normal to the stretching surface beneath the non-Newtonian flow. The governing equations of the model in the form of partial differential equations, are later transformed to a set of nonlinear ordinary differential equations (ODEs) using suitable similarity variables. A numerical scheme is employed to solve the ODE system. The flow velocity, temperature and nanoparticles profiles are examined. The heat transfer of the flow is analysed. Comparison between the effects of active and passive controls of nanoparticles in the non-Newtonian flow is also discussed
Venom Proteome of Spine-Bellied Sea Snake (Hydrophis curtus) from Penang, Malaysia: Toxicity Correlation, Immunoprofiling and Cross-Neutralization by Sea Snake Antivenom
No full textThe venom proteome of Hydrophis curtus (synonym: Lapemis hardwickii) from Penang, Malaysia was investigated with nano-electrospray ionization-liquid chromatography tandem mass spectrometry (ESI-LCMS/MS) of the reverse-phase high-performance liquid chromatography (HPLC) venom fractions. Thirty distinct protein forms were identified as toxins from ten families. The three major protein families were phospholipase A2 (PLA2, 62.0% of total venom proteins), three-finger toxin (3FTX, 26.33%) and cysteine-rich secretory protein (CRiSP, 9.00%). PLA2 comprises diverse homologues (11 forms), predominantly the acidic subtypes (48.26%). 3FTX composed of one short alpha-neurotoxin (SNTX, 22.89%) and four long alpha-neurotoxins (LNTX, 3.44%). Both SNTX and LNTX were lethal in mice (intravenous LD50 = 0.10 and 0.24 µg/g, respectively) but the PLA2 were non-lethal (LD50 >1 µg/g). The more abundant and toxic SNTX appeared to be the main driver of venom lethality (holovenom LD50 = 0.20 µg/g). The heterologous Sea Snake Antivenom (SSAV, Australia) effectively cross-neutralized the venom (normalized potency = 9.35 mg venom neutralized per g antivenom) and the two neurotoxins in vivo, with the LNTX being neutralized more effectively (normalized potency = 3.5 mg toxin/g antivenom) than SNTX (normalized potency = 1.57 mg/g). SSAV immunorecognition was strong toward PLA2 but moderate-to-weak toward the alpha-neurotoxins, indicating that neutralization of the alpha-neurotoxins should be further improved
Analyses of magnetic and gravity data in search for meteorite impact crater at Bukit Bunuh, Lenggong, Perak, Malaysia
No full textAnalyses and interpretation of magnetic and gravity fields data acquired at Bukit Bunuh, Lenggong, Perak, Malaysia have been carried out in this study. The objective is to identify the meteorite impact crater and possible rebound locations. This study was instigated by an archaeological investigation carried out by the Centre for Global Archaeological Research, Universiti Sains Malaysia. The investigation suggested evidences of shock metamorphisms (suevite breccia) and crater morphology at Bukit Bunuh in Lenggong area of northern Perak, Malaysia. To justify the occurrence of the impact crater, ground magnetic and gravity surveys were conducted first as regional study in the entire area, followed by detailed study at the suspected crater region. Data from both surveys were compiled and corrected. The residual magnetic data ranged between -272 nT and +134.2 nT, whereas the Bouguer gravity data were between -25 mGal and 120 mGal. Both the magnetic and gravity data were gridded and plotted for qualitative interpretation. It was found that low magnetic and gravity region, believed to be an impact crater which is now filled with sediments and surrounded by a highly magnetised shallow bedrock, exists at the mid-part of the study area. Other high magnetic and gravity key features located within the central regions are interpreted as rebounds. In conclusion, the impact structure was successfully modelled as a complex impact crater
Collaboration of public agencies in innovation and startups in Malaysia
Get PDF•The implementation of creativity and innovation in public administration is crucial to driving Malaysia towards becoming a developed country.
•Indeed, many governments have embarked on the innovation aspects of the agenda of policymakers.
•The adoption of innovations in the public administration sector is seen as a complex process.
•Innovation implementation in public administration depends on the individual’s motivation to innovate as well as their readiness to adapt innovation implementation to the environment
Social media metrics analytics: Study on B2C (Business to Consumer) Brand's Page
Get PDFOne of the most prominent way of connecting with customers via Social Networking Sites (SNS) is to generate a brand page in Facebook (called fan page) containing products contents and publish regularly postings on these pages. Customers will respond differently to these postings. In determining the efficiency of social networking sites, marketers are analyzing metrics to calculate the engagement rate (e.g. number of comments, share and likings in fan pages). The study applied Pseudo-theories and analyzed a total 3543 brand posts from 19 of the most popular B2C (Business to Consumer) fan pages of Malaysia. Data from September 2016-August 2017 were collected for analyses, which were available online from the Brand's fan pages. The Fan-page content was analyzed using Netnography and Cross Section Regression of the EVIEWS 9 software for its impact on multiple contents upon user's engagement functions. The study explored the descriptive statistics of online user's engagement actions, or PTA (People Talking About) metrics, and the findings specify that the diversity of different posts influences the number of comments, likes, and the number of shares differently. Our research explored the fact that not all contents are suitable for enhancing the number of likes, they increase the number of shares and comments, and vice versa. The findings of the study will allow e-marketers to update informational analyses upon the effectiveness of the posted contents and descriptive idea on users' preferred actions
Metabolomic analysis of low and high biofilm-forming Helicobacter pylori strains
Get PDFThe biofilm-forming-capability of Helicobacter pylori has been suggested to be among factors influencing treatment outcome. However, H. pylori exhibit strain-to-strain differences in biofilm-forming-capability. Metabolomics enables the inference of spatial and temporal changes of metabolic activities during biofilm formation. Our study seeks to examine the differences in metabolome of low and high biofilm-formers using the metabolomic approach. Eight H. pylori clinical strains with different biofilm-forming-capability were chosen for metabolomic analysis. Bacterial metabolites were extracted using Bligh and Dyer method and analyzed by Liquid Chromatography/Quadrupole Time-of-Flight mass spectrometry. The data was processed and analyzed using the MassHunter Qualitative Analysis and the Mass Profiler Professional programs. Based on global metabolomic profiles, low and high biofilm-formers presented as two distinctly different groups. Interestingly, low-biofilm-formers produced more metabolites than high-biofilm-formers. Further analysis was performed to identify metabolites that differed significantly (p-value < 0.005) between low and high biofilm-formers. These metabolites include major categories of lipids and metabolites involve in prostaglandin and folate metabolism. Our findings suggest that biofilm formation in H. pylori is complex and probably driven by the bacterium' endogenous metabolism. Understanding the underlying metabolic differences between low and high biofilm-formers may enhance our current understanding of pathogenesis, extragastric survival and transmission of H. pylori infections
A hybrid unsupervised approach toward EEG epileptic spikes detection
No full textEpileptic spikes are complementary sources of information in EEG to diagnose and localize the origin of epilepsy. However, not only is visual inspection of EEG labor intensive, time consuming, and prone to human error, but it also needs long-term training to acquire the level of skill required for identifying epileptic discharges. Therefore, computer-aided approaches were employed for the purpose of saving time and increasing the detection and source localization accuracy. One of the most important artifacts that may be confused as an epileptic spike, due to morphological resemblance, is eye blink. Only a few studies consider removal of this artifact prior to detection, and most of them used either visual inspection or computer-aided approaches, which need expert supervision. Consequently, in this paper, an unsupervised and EEG-based system with embedded eye blink artifact remover is developed to detect epileptic spikes. The proposed system includes three stages: eye blink artifact removal, feature extraction, and classification. Wavelet transform was employed for both artifact removal and feature extraction steps, and adaptive neuro-fuzzy inference system for classification purpose. The proposed method is verified using a publicly available EEG dataset. The results show the efficiency of this algorithm in detecting epileptic spikes using low-resolution EEG with least computational complexity, highest sensitivity, and lesser human interaction compared to similar studies. Moreover, since epileptic spike detection is a vital component of epilepsy source localization, therefore this algorithm can be utilized for EEG-based pre-surgical evaluation of epilepsy
Cloning and characterization of short‐chain N ‐acyl homoserine lactone‐producing Enterobacter asburiae strain L1 from lettuce leaves
No full textIn gram-negative bacteria, bacterial communication or quorum sensing (QS) is achieved using common signaling molecules known as N-acyl homoserine lactones (AHL). We have previously reported the genome of AHL-producing bacterium, Enterobacter asburiae strain L1. In silico analysis of the strain L1 genome revealed the presence of a pair of luxI/R genes responsible for AHL-type QS, designated as easIR. In this work, the 639 bp luxI homolog, encoding 212 amino acids, have been cloned and overexpressed in Escherichia coli BL21 (DE3)pLysS. The purified protein (~25 kDa) shares high similarity to several members of the LuxI family among different E asburiae strains. Our findings showed that the heterologously expressed EasI protein has activated violacein production by AHL biosensor Chromobacterium violaceum CV026 as the wild-type E. asburiae. The mass spectrometry analysis showed the production of N-butanoyl homoserine lactone and N–hexanoyl homoserine lactone from induced E. coli harboring the recombinant EasI, suggesting that EasI is a functional AHL synthase. E. asburiae strain L1 was also shown to possess biofilm-forming characteristic activity using crystal violet binding assay. This is the first report on cloning and characterization of the luxI homolog from E. asburiae