Browse publications by year: 2019

  1. Leong HY, Chang YK, Ooi CW, Law CL, Julkifle AL, Show PL
    Front Chem, 2019;7:201.
    PMID: 31001522 DOI: 10.3389/fchem.2019.00201
    Nowadays, downstream bioprocessing industries inclines towards the development of a green and high efficient bioseparation technology. Betacyanins are presently gaining higher interest in the food science as driven by their high tinctorial strength and health promoting functional properties. In this study, a novel green integration process of liquid biphasic electric partitioning system (LBEPS) was proposed for betacyanins extraction from peel and flesh of red-purple pitaya. Initially, the betacyanins extraction using LBEPS with initial settings was compared with that of liquid biphasic partitioning system (LBPS), and the results revealed that both systems demonstrated a comparable betacyanins extraction. This was followed by further optimizing the LBEPS for better betacyanins extraction. Several operating parameters including operation time, voltage applied, and position of graphitic electrodes in the system were investigated. Moreover, comparison between optimized LBEPS and LBPS with optimized conditions of electric system (as post-treatment) as well as color characterization and antioxidant properties assessment were conducted. Overall, the betacyanins extraction employing the optimized LBEPS showed the significant highest values of betacyanins concentration in alcohol-rich top phase (C
    t
    ) and partition coefficient (K) of betacyanins from peel (99.256 ± 0.014% and 133.433 ± 2.566) and flesh (97.189 ± 0.172% and 34.665 ± 2.253) of red-purple pitaya. These results inferred that an optimal betacyanins extraction was successfully achieved by this approach. Also, the LBEPS with the peel and flesh showed phase volume ratio (V
    r
    ) values of 1.667 and 2.167, respectively, and this indicated that they have a clear biphasic separation. In addition, the peel and flesh extract obtained from the optimized LBEPS demonstrated different variations of red color as well as their antioxidant properties were well-retained. This article introduces a new, reliable, and effective bioseparation approach for the extraction of biomolecules, which is definitely worth to explore further as a bioseparation tool in the downstream bioprocessing.
  2. Tan CY, Razali SNO, Goh KJ, Shahrizaila N
    J Peripher Nerv Syst, 2019 06;24(2):168-173.
    PMID: 31001904 DOI: 10.1111/jns.12320
    Guillain-Barré syndrome (GBS) is an acute immune-mediated neuropathy that has variable disease course and outcome. The Erasmus GBS outcome score (EGOS), modified EGOS (mEGOS), and Erasmus GBS respiratory insufficiency score (EGRIS) are prognostic models designed to predict the functional outcome of GBS patients at 6 months (EGOS and mEGOS) and the need for mechanical ventilation within a week of admission (EGRIS). The models were primarily developed in the Dutch GBS population, and thus the usefulness of these models in other GBS cohorts is less clear. In the current study, we aimed to validate mEGOS, EGOS, and EGRIS in Malaysian GBS patients. A total of 107 patients with GBS and its variants were consecutively recruited. Patients with GBS and Miller Fisher syndrome (MFS) were analysed separately. In the GBS cohort, high mEGOS and EGOS scores were significantly correlated with poor outcome at 6 months (mEGOS on admission: r = .381, P = .005; mEGOS at day 7 of admission: r = .507, P 
    MeSH terms: Adolescent; Adult; Aged; Female; Humans; Malaysia; Male; Middle Aged; Models, Theoretical*; Prognosis; Respiration, Artificial; Miller Fisher Syndrome/diagnosis*; Miller Fisher Syndrome/physiopathology; Miller Fisher Syndrome/therapy; Guillain-Barre Syndrome/diagnosis*; Guillain-Barre Syndrome/physiopathology; Guillain-Barre Syndrome/therapy; Young Adult
  3. Cicero A, Meyer D, Shearer MP, AbuBakar S, Bernard K, Carus WS, et al.
    Emerg Infect Dis, 2019 May;25(5).
    PMID: 31002062 DOI: 10.3201/eid2505.181659
    A strategic multilateral dialogue related to biosecurity risks in Southeast Asia, established in 2014, now includes participants from Singapore, Malaysia, Indonesia, Thailand, Philippines, and the United States. This dialogue is conducted at the nonministerial level, enabling participants to engage without the constraints of operating in their official capacities. Participants reflect on mechanisms to detect, mitigate, and respond to biosecurity risks and highlight biosecurity issues for national leadership. Participants have also identified factors to improve regional and global biosecurity, including improved engagement and collaboration across relevant ministries and agencies, sustainable funding for biosecurity programs, enhanced information sharing for communicable diseases, and increased engagement in international biosecurity forums.
    MeSH terms: Asia, Southeastern; Communicable Diseases; Indonesia; Leadership; Malaysia; Organizations; Philippines; Risk; Singapore; Thailand; United States; Information Dissemination
  4. Tan KX, Danquah MK, Pan S, Yon LS
    J Pharm Sci, 2019 09;108(9):2934-2941.
    PMID: 31002808 DOI: 10.1016/j.xphs.2019.03.037
    Efficient delivery of adequate active ingredients to targeted malignant cells is critical, attributing to recurrent biophysical and biochemical challenges associated with conventional pharmaceutical delivery systems. These challenges include drug leakage, low targeting capability, high systemic cytotoxicity, and poor pharmacokinetics and pharmacodynamics. Targeted delivery system is a promising development to deliver sufficient amounts of drug molecules to target cells in a controlled release pattern mode. Aptameric ligands possess unique affinity targeting capabilities which can be exploited in the design of high pay-load drug formulations to navigate active molecules to the malignant sites. This study focuses on the development of a copolymeric and multifunctional drug-loaded aptamer-conjugated poly(lactide-co-glycolic acid)-polyethylenimine (PLGA-PEI) (DPAP) delivery system, via a layer-by-layer synthesis method, using a water-in-oil-in-water double emulsion approach. The binding characteristics, targeting capability, biophysical properties, encapsulation efficiency, and drug release profile of the DPAP system were investigated under varying conditions of ionic strength, polymer composition and molecular weight (MW), and degree of PEGylation of the synthetic core. Experimental results showed increased drug release rate with increasing buffer ionic strength. DPAP particulate system obtained the highest drug release of 50% at day 9 at 1 M NaCl ionic strength. DPAP formulation, using PLGA 65:35 and PEI MW of ∼800 Da, demonstrated an encapsulation efficiency of 78.93%, and a loading capacity of 0.1605 mg bovine serum albumin per mg PLGA. DPAP (PLGA 65:35, PEI MW∼25 kDa) formulation showed a high release rate with a biphasic release profile. Experimental data depicted a lower targeting power and reduced drug release rate for the PEGylated DPAP formulations. The outcomes from the present study lay the foundation to optimize the performance of DPAP system as an effective synthetic drug carrier for targeted delivery.
    MeSH terms: Drug Carriers/chemistry*; Drug Compounding/methods*; Particle Size; Polyethyleneimine/chemistry; Serum Albumin, Bovine/administration & dosage; Serum Albumin, Bovine/pharmacokinetics*; Aptamers, Nucleotide/administration & dosage; Aptamers, Nucleotide/pharmacokinetics*; Drug Liberation
  5. Wahib NB, Khandaker MU, Aqilah Binti Mohamad Ramli N, Sani SFA, Bradley DA
    Appl Radiat Isot, 2019 Jun;148:218-224.
    PMID: 31003071 DOI: 10.1016/j.apradiso.2019.04.001
    Study has been made of the thermoluminescence (TL) yield of various glass-based commercial kitchenware (Reko-China, Skoja-France, Godis-China, Glass Tum-Malaysia, Lodrat-France). Interest focuses on their potential for retrospective dosimetry. Use was made of a60Co gamma-ray irradiator, delivering doses in the range 2-10 Gy. Results for the various media show all the glassware brands to yield linearity of response against dose, with a lower limit of detection of ∼0.06 and ∼0.08 Gy for loose and compact powdered samples. Among all of the brands under study, the Lodrat glassware provides the greatest sensitivity, at 6.0 E+02 nC g-1 Gy-1 and 1.5E+03 nC g-1 Gy-1 for compact- and loose-powdered forms respectively. This is sufficiently sensitive to allow its use as a TL material for accident dosimetry (2 Gy being the threshold dose for the onset of a number of deterministic biological effects, including skin erythema and sterility). Energy Dispersive X-ray (EDX) analyses have been conducted, showing the presence of a number of impurities (including C, O, Na, Mg, Al, Si, Ca and Br). Fading of the irradiated glasses show the amount of better than 3% and 5% of the stored energy for both loose and compact powdered samples within 9 days post irradiation. As such, commercial kitchenware glass has the potential to act as relatively good TL material for gamma radiation dosimetry at accident levels. This is the first endeavour reporting the TL properties of low cost commercial kitchenware glasses for gamma-ray doses in the few Gy range, literature existing for doses from 8 Gy to 200 Gy.
    MeSH terms: Glass*; Radiometry/methods*; Retrospective Studies; Thermoluminescent Dosimetry/methods*; Reproducibility of Results; Limit of Detection
  6. Damodaran T, Müller CP, Hassan Z
    Pharmacol Rep, 2019 Jun;71(3):443-448.
    PMID: 31003155 DOI: 10.1016/j.pharep.2019.01.012
    BACKGROUND: Chronic cerebral hypoperfusion (CCH) can induce the accumulation of reactive oxygen species, which leads to oxidative damage, neuronal injury, and central cholinergic dysfunction in vulnerable regions of the brain, such as the hippocampus and cerebral cortex. These effects can lead to significant cognitive impairments in clinical populations of vascular dementia (VaD). The present studies aimed to investigate the role of the cholinergic system in memory functions and hippocampal long-term potentiation (LTP) impairments induced by CCH in rats.

    METHODS: Male Sprague Dawley rats were subjected to permanent bilateral occlusion of common carotid arteries (PBOCCA) or sham surgery. Then, PBOCCA rats received ip injections with, either vehicle (control group), the muscarinic receptor agonist oxotremorine (0.1 mg/kg), or the acetylcholinesterase inhibitor physostigmine (0.1 mg/kg). Cognitive functions were evaluated using a passive avoidance task and the Morris water maze test. In addition, hippocampal LTP was recorded in vivo under anaesthesia.

    RESULTS: The PBOCCA rats exhibited significant deficits in passive avoidance retention and spatial learning and memory tests. They also showed a suppression of LTP formation in the hippocampus. Oxotremorine and physostigmine significantly improved the learning and memory deficits as well as the suppression of LTP in PBOCCA rats.

    CONCLUSIONS: The present data suggest that the cholinergic system plays an important role in CCH-induced cognitive deficits and could be an effective therapeutic target for the treatment of VaD.

    MeSH terms: Acetylcholine/pharmacology; Animals; Brain Ischemia/complications*; Cognition Disorders/drug therapy*; Disease Models, Animal; Hippocampus/drug effects*; Male; Memory/drug effects*; Memory Disorders/drug therapy*; Memory Disorders/etiology; Neurons/drug effects; Rats, Sprague-Dawley; Long-Term Potentiation/drug effects*; Cholinergic Agents/pharmacology; Cholinergic Agents/therapeutic use*; Maze Learning/drug effects; Rats
  7. Viswabhargav CSS, Tripathy RK, Acharya UR
    Comput Biol Med, 2019 05;108:20-30.
    PMID: 31003176 DOI: 10.1016/j.compbiomed.2019.03.016
    Sleep is a prominent physiological activity in our daily life. Sleep apnea is the category of sleep disorder during which the breathing of the person diminishes causing the alternation in the upper airway resistance. The electrocardiogram derived respiration (EDR) and heart rate (RR-time-series) signals are normally used for the detection of sleep apnea as these two signals capture cardio-pulmonary activity information. Hence, the analysis of these two signals provides vital information about sleep apnea. In this paper, we propose the novel sparse residual entropy (SRE) features for the automated detection of sleep apnea using EDR and heart rate signals. The features required for the automated detection of sleep apnea are extracted in three steps: (i) atomic decomposition based residual estimation from both EDR and heart rate signals using orthogonal matching pursuit (OMP) with different dictionaries, (ii) estimation of probabilities from each sparse residual, and (iii) calculation of the entropy features. The proposed SRE features are fed to the combination of fuzzy K-means clustering and support vector machine (SVM) to pick the best performing classifier. The experimental results demonstrate that the proposed SRE features with radial basis function (RBF) kernel-based SVM classifier yielded higher performance with accuracy, sensitivity and specificity values of 78.07%, 78.01%, and 78.13%, respectively with Fourier dictionary and 10-fold cross-validation. For subject-specific or leave-one-out validation case, the SVM classifier has sensitivity and specificity of 85.43% and 92.60%, respectively using SRE features with Fourier dictionary (FD).
    MeSH terms: Electrocardiography*; Heart Rate*; Humans; Respiration*; Signal Processing, Computer-Assisted*; Sleep Apnea Syndromes/physiopathology*; Support Vector Machine*
  8. Edling CE, Fazmin IT, Chadda KR, Ahmad S, Valli H, Grace AA, et al.
    Biosci Rep, 2019 04 30;39(4).
    PMID: 30914453 DOI: 10.1042/BSR20190127
    Mice deficient in mitochondrial promoter peroxisome proliferator activated receptor-γ co-activator-1β (Pgc-1β-/- ) is a valuable model for metabolic diseases and has been found to present with several pathologies including ventricular arrhythmia. In the present study, our aim was to shed light on the molecular mechanisms behind the observed arrhythmic substrate by studying how the expression of selected genes critical for cardiac function differs in wild-type (WT) compared with Pgc-1β knockout mice and young compared with aged mice. We found that a clear majority of genes are down-regulated in the Pgc-1β-/- ventricular tissue compared with the WT. Although most individual genes are not significantly differentially expressed, a pattern is apparent when the genes are grouped according to their functional properties. Genes encoding proteins relating to ATPase activity, potassium ion channels relating to repolarisation and resting membrane potential, and genes encoding proteins in the cAMP pathway are found to be significantly down-regulated in the Pgc-1β deficient mice. On the contrary, the pacemaker channel genes Hcn3 and Hcn4 are up-regulated in subsets of the Pgc-1β deficient tissue. Furthermore, we found that with age, especially in the Pgc-1β-/- genotype, most genes are up-regulated including genes relating to the resting membrane potential, calcium homeostasis, the cAMP pathway, and most of the tested adrenoceptors. In conclusion, we here demonstrate how a complex pattern of many modest changes at gene level may explain major functional differences of the action potential related to ageing and mitochondrial dysfunction.
    MeSH terms: Aging*; Animals; Arrhythmias, Cardiac/metabolism; Arrhythmias, Cardiac/physiopathology; Gene Expression Regulation; Heart Ventricles/metabolism*; Heart Ventricles/physiopathology; Membrane Potentials; Mice, Inbred C57BL; Mitochondria/genetics; Mitochondria/metabolism*; Mitochondria/pathology; Ventricular Function; Gene Deletion; Mice, Knockout; Mice; Transcriptome*; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/genetics*; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism
  9. Reza MS, Ahmed A, Caesarendra W, Abu Bakar MS, Shams S, Saidur R, et al.
    Bioengineering (Basel), 2019 Apr 16;6(2).
    PMID: 30995765 DOI: 10.3390/bioengineering6020033
    To evaluate the possibilities for biofuel and bioenergy production Acacia Holosericea, which is an invasive plant available in Brunei Darussalam, was investigated. Proximate analysis of Acacia Holosericea shows that the moisture content, volatile matters, fixed carbon, and ash contents were 9.56%, 65.12%, 21.21%, and 3.91%, respectively. Ultimate analysis shows carbon, hydrogen, and nitrogen as 44.03%, 5.67%, and 0.25%, respectively. The thermogravimetric analysis (TGA) results have shown that maximum weight loss occurred for this biomass at 357 °C for pyrolysis and 287 °C for combustion conditions. Low moisture content (<10%), high hydrogen content, and higher heating value (about 18.13 MJ/kg) makes this species a potential biomass. The production of bio-char, bio-oil, and biogas from Acacia Holosericea was found 34.45%, 32.56%, 33.09% for 500 °C with a heating rate 5 °C/min and 25.81%, 37.61%, 36.58% with a heating rate 10 °C/min, respectively, in this research. From Fourier transform infrared (FTIR) spectroscopy it was shown that a strong C-H, C-O, and C=C bond exists in the bio-char of the sample.
    MeSH terms: Acacia; Brunei; Carbon; Fourier Analysis; Heating; Hydrogen; Nitrogen; Plant Oils; Thermogravimetry; Weight Loss; Spectroscopy, Fourier Transform Infrared; Biomass; Biofuels; Polyphenols
  10. Soraya A, Chay SY, Shukri R, Mohamad Ghazali F, Muhammad K, Noranizan MA, et al.
    J Food Sci Technol, 2019 Apr;56(4):1801-1810.
    PMID: 30996416 DOI: 10.1007/s13197-019-03624-w
    Pulsed-UV is an emerging innovation in non-thermal processing and is scarcely explored. This study introduces a combined treatment of microwave and pulsed-UV to reduce the microbial load in yellow alkaline noodle (YAN), a popular staple food among South East Asians that is easily perishable, without jeopardising its textural qualities. Results indicated that the combination of 5 s microwave (power = 900 W; frequency = 2450 MHz) and 3.5 J/cm2 pulsed-UV significantly reduced aerobic plate count and spore forming bacteria, from 637.5 to 50 CFU/g and 1500 to 100 CFU/g, respectively. In terms of textural properties, even though significant changes were detected in hardness and springiness for treated YAN kept at ambient storage as compared to control, the alterations were not prominent. Based on these observations, it is concluded that a combined treatment of microwave and pulsed-UV successfully improved the shelf life of YAN at ambient storage by 50%, from 1.0 day (control) to 1.5 days (treated sample) and by 140%, from 2.0 to 4.8 weeks at chilled storage. Current study proves the potential of microwave + pulsed-UV, a "green" hurdle treatment, to extend the shelf life of preservative-free YAN without causing major undesirable textural alterations on the noodle.
  11. Seow EK, Gan CY, Tan TC, Lee LK, Easa AM
    J Food Sci Technol, 2019 Apr;56(4):2105-2114.
    PMID: 30996444 DOI: 10.1007/s13197-019-03691-z
    Present study compared the rheological properties of glutinous rice flour (GRF) gel (33.3%, w/v) added with raw bee honey (RBH) or stingless bee honey (SBH) with/without heating treatment. RBH (diatase activity: 12.14 Schade) and SBH (1.53 Schade) significantly reduced the network of GRF gel by lowering the gel viscosity, with RBH having the highest rate of viscosity decrease (- 2.74 × 10-5 Pa). As the addition of heated-SBH or heated-RBH did not reduce gel viscosity, it was hypothesised that active diastase played a major role to weaken gel network. This was further supported by the significant and the lowest storage modulus (G') value of RBH-GRF gel (5.99 ± 0.02 Pa), as compared to SBH-GRF (6.27 ± 0.04 Pa) and control (6.33 ± 0.04 Pa). A detail of rheological behaviour of the gels was further explained using power law. Overall, this GRF gel model has successfully demonstrated the potential of honey diastase in weakening network of starch-based food.
    MeSH terms: Amylases; Animals; Bees; Flour; Gels; Hot Temperature; Heating; Honey; Rheology; Oryza; Starch; Viscosity
  12. Gee T, Lim SY, Sudhakaran N, Hassan MF
    J Surg Case Rep, 2019 Apr;2019(4):rjz095.
    PMID: 30997009 DOI: 10.1093/jscr/rjz095
    Short bowel syndrome in adults occurs as a result of massive small intestinal resection commonly due to severe Crohn's disease, volvulus or tumors. Diarrhea and weight loss are hallmarks of malabsorption which are aggravated if the colon is removed along with the small intestinal resection. Enteral nutrition autonomy is difficult to achieve in such cases of malabsorption where parenteral nutrition are required more often than not. We report a case of short bowel syndrome with severe malabsorption following extensive small bowel removal. The patient eventually underwent intestinal rehabilitation surgery and achieved independence from parenteral nutrition.
    MeSH terms: Adult; Colon; Crohn Disease; Diarrhea; Enteral Nutrition; Humans; Intestine, Small; Neoplasms; Parenteral Nutrition; Parenteral Nutrition, Total; Short Bowel Syndrome; Weight Loss; Intestinal Volvulus
  13. Roohi SA, Barritault D
    Clin Case Rep, 2019 Apr;7(4):619-625.
    PMID: 30997049 DOI: 10.1002/ccr3.2054
    CACIPLIQ20® significantly improved the outcomes of severe burn injuries of the hand. Healing was accelerated, with little or no scarring, allowing for greater mobility over the joints and maintained suppleness. Functional recovery was achieved in all cases.
  14. Woo YL
    Journal of virus eradication, 2019 Mar 04;5(Suppl 1):10-11.
    PMID: 30997147
    Malaysia's approach to reducing the burden of HPV-related disease has centred on adolescent vaccination and cervical screening with Pap smears. While the vaccination programme has been broadly successful, Pap smear screening has been less successful. In an effort to improve screening uptake, the ROSE 1.0 pilot aimed to create more efficient screening, with improved quality and lower total cost.
    MeSH terms: Adolescent; Female; Humans; Malaysia; Vaccination; Vaginal Smears; Immunization Programs; Papanicolaou Test; Pilots
  15. Krishnasamy S, Kew EP, Bishay E
    J Thorac Dis, 2019 Mar;11(Suppl 3):S478-S479.
    PMID: 30997252 DOI: 10.21037/jtd.2019.01.67
  16. Rigatelli G, Zuin M, Fong A, Tai TT, Nguyen T
    J Transl Int Med, 2019 Mar;7(1):22-28.
    PMID: 30997353 DOI: 10.2478/jtim-2019-0005
    Background and Objective: Ostial LM stenting potentially induces turbulence in the aortic wall near the LM ostium, which might be correlated with aorta dilation and dissection. We investigated through a computational fluid dynamic analysis (CFD), the presence and potential consequences of flow turbulences both in the ascending aorta and arch after a stenting left main (LM) mid shaft or distal disease.

    Methods: The model of the ascending aorta and left coronary artery was reconstructed reviewing both angiographic and echocardiographic measurements of 80 consecutive patients (43 males, mean age 75.1 ± 6.2 years) with significant LM mid shaft or distal disease treated in our institution. For stent simulation, a third-generation everolimus-eluting stent was reconstructed. Two stenting procedures (lesion 1:1 or ostial coverage) were investigated.

    Results: The net area averaged WSS of the model resulted higher when the stent covered the lesion 1:1 compared to the ostial coverage (3.68 vs. 2.06 Pa, P=0.01 and 3.97 vs. 1.98 Pa, P < 0.001, respectively). LM ostial coverage generates more turbulences in the LM itself, in the aortic wall at ostium level, and at the sino-tubular junction compared with the stenting of the lesion 1:1. Conversely, in the ascending aorta, the WSS appears lower when stenting the lesion 1:1.

    Conclusion: Extending the stent coverage up to the ostium, when the ostial region is not diseased, might induce unfavorable alterations of flow; not only both at the level of the LM lesion and ostium sites, but also in the ascending aorta and aortic arch, potentially predisposing the aortic wall to long-term damage.

  17. Lau KF, Tan KS, Goh KJ, Ramli N, Tai SM
    Ann Acad Med Singap, 2019 Mar;48(3):109-111.
    PMID: 30997481
    MeSH terms: Cerebral Angiography; Female; Humans; Magnetic Resonance Imaging; Medulla Oblongata/blood supply*; Middle Aged; Bulbar Palsy, Progressive/etiology; Quadriplegia/etiology; Vertebral Artery/abnormalities; Magnetic Resonance Angiography; Brain Stem Infarctions/complications; Brain Stem Infarctions/physiopathology*; Central Nervous System Vascular Malformations/complications
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