Displaying publications 41 - 60 of 118 in total

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  1. Koyande AK, Chew KW, Lim JW, Lee SY, Lam MK, Show PL
    Eng Life Sci, 2019 Dec;19(12):968-977.
    PMID: 32624986 DOI: 10.1002/elsc.201900068
    Microalgae biomass has been consumed as animal feed, fish feed and in human diet due to its high nutritional value. In this experiment, microalgae specie of Chlorella Vulgaris FSP-E was utilized for protein extraction via simple sugaring-out assisted liquid biphasic electric flotation system. The external electric force provided to the two-phase system assists in disruption of rigid microalgae cell wall and releases the contents of microalgae cell. This experiment manipulates various parameters to optimize the set-up. The liquid biphasic electric flotation set-up is compared with a control liquid biphasic flotation experiment without the electric field supply. The optimized separation efficiency of the liquid biphasic electric flotation system was 73.999 ± 0.739% and protein recovery of 69.665 ± 0.862% compared with liquid biphasic flotation, the separation efficiency was 61.584 ± 0.360% and protein recovery was 48.779 ± 0.480%. The separation efficiency and protein recovery for 5 × time scaled-up system was observed at 52.871 ± 1.236% and 73.294 ± 0.701%. The integration of simultaneous cell-disruption and protein extraction ensures high yield of protein from microalgae. This integrated method for protein extraction from microalgae demonstrated its potential and further research can lead this technology to commercialization.
  2. Muthu N, Lee SY, Phua KK, Bhore SJ
    Bioinformation, 2016;12(12):420-424.
    PMID: 28405126 DOI: 10.6026/97320630012420
    Plants are very complex organisms that produce medicinally important natural products. The Star-fruit producing plant (Averrhoa carambola L.) is a species of woody plant in the family Oxalidaceae native to the Philippines, Indonesia, Malaysia, Vietnam, India, Bangladesh and Sri Lanka; but, cultivated in many parts of the world. Star-fruits are popular tropical fruits and used commonly in Ayurvedic and Traditional Chinese Medicines (TCM) in India, China, and Brazil to relieve ailments such as chronic headache, fever, cough, gastro-enteritis, diarrhoea, ringworm infections, and skin inflammations. However, this fruit contains high amount of oxalate, which is hazardous for uremic patients, and caramboxin (CBX), which is neurotoxic. The aim of this review is to highlight the nutritional, medicinal and toxicological traits of the star-fruits.
  3. Deris ZZ, Leow VM, Wan Hassan WM, Nik Lah NA, Lee SY, Siti Hawa H, et al.
    Trop Biomed, 2009 Dec;26(3):320-5.
    PMID: 20237446
    Vibrio cholerae infection is mainly caused acute diarrhoea disease. Bacteraemia due to non-O1 V. cholerae is rare and mainly reported in liver cirrhotic patients. We report one case of non-O1 V. cholerae bacteraemia in splenectomised thalassaemic patient who presented with septic shock secondary to abdominal sepsis. She had undergone emergency laporatomy and was managed in the intensive care unit for nine days. She was treated with meropenem and doxycyline and discharged well after fourteen days of admission. The V. cholerae was identified by API 20NE, serotype and polymerase chain reaction showed as non-O1, non-O139 strain. Besides known cholera-like toxin and El Tor hemolysin, with increasing reported cases of V. cholerae bacteraemia, there is possibility of other virulence factors that allow this organism to invade the bloodstream.
  4. Lee SY, Kamarul T
    Int J Biol Macromol, 2014 Mar;64:115-22.
    PMID: 24325858 DOI: 10.1016/j.ijbiomac.2013.11.039
    In this study, a chitosan co-polymer scaffold was prepared by mixing poly(vinyl alcohol) (PVA), NO, carboxymethyl chitosan (NOCC) and polyethylene glycol (PEG) solutions to obtain desirable properties for chondrocyte cultivation. Electron beam (e-beam) radiation was used to physically cross-link these polymers at different doses (30 kGy and 50 kGy). The co-polymers were then lyophilized to form macroporous three-dimensional (3-D) matrix. Scaffold morphology, porosity, swelling properties, biocompatibility, expression of glycosaminoglycan (GAG) and type II collagen following the seeding of primary chondrocytes were studied up to 28 days. The results demonstrate that irradiation of e-beam at 50 kGy increased scaffold porosity and pore sizes subsequently enhanced cell attachment and proliferation. Scanning electron microscopy and transmission electron microscopy revealed extensive interconnected microstructure of PVA-PEG-NOCC, demonstrated cellular activities on the scaffolds and their ability to maintain chondrocyte phenotype. In addition, the produced PVA-PEG-NOCC scaffolds showed superior swelling properties, and increased GAG and type II collagen secreted by the seeded chondrocytes. In conclusion, the results suggest that by adding NOCC and irradiation cross-linking at 50 kGy, the physical and biological properties of PVA-PEG blend can be further enhanced thereby making PVA-PEG-NOCC a potential scaffold for chondrocytes.
  5. Lee SY, Wong WF, Dong J, Cheng KK
    Molecules, 2020 Aug 20;25(17).
    PMID: 32825228 DOI: 10.3390/molecules25173783
    Macrophage activation is a key event that triggers inflammatory response. The activation is accompanied by metabolic shift such as upregulated glucose metabolism. There are accumulating evidences showing the anti-inflammatory activity of Momordica charantia. However, the effects of M. charantia on inflammatory response and glucose metabolism in activated macrophages have not been fully established. The present study aimed to examine the effect of M. charantia in modulating lipopolysaccharide (LPS)-induced inflammation and perturbed glucose metabolism in RAW264.7 murine macrophages. The results showed that LPS-induced NF-κB (p65) nuclear translocation was inhibited by M. charantia treatment. In addition, M. charantia was found to reduce the expression of inflammatory genes including IL6, TNF-α, IL1β, COX2, iNOS, and IL10 in LPS-treated macrophages. Furthermore, the data showed that M. charantia reduced the expression of GLUT1 and HK2 genes and lactate production (-28%), resulting in suppression of glycolysis. Notably, its effect on GLUT1 gene expression was found to be independent of LPS-induced inflammation. A further experiment also indicated that the bioactivities of M. charantia may be attributed to its key bioactive compound, charantin. Taken together, the study provided supporting evidences showing the potential of M. charantia for the treatment of inflammatory disorders.
  6. Jamal J, Roebuck MM, Lee SY, Frostick SP, Abbas AA, Merican AM, et al.
    Int J Biochem Cell Biol, 2020 09;126:105800.
    PMID: 32673644 DOI: 10.1016/j.biocel.2020.105800
    OBJECTIVES: To compare mechanobiological response of synovial fibroblasts (SFb) from OA patient cohorts under mechanical load and inflammatory stressors for better understanding of SFb homeostatic functions.

    METHODS: Primary SFb isolated from knee synovium of OA obese (OA-ob:SFb), OA-pre-obese (OA-Pob:SFb), non-OA arthroscopic (scope:SFb), and non-OA arthroscopic with cartilage damage (scope-CD:SFb) were exposed to OA-conditioned media (OACM), derived from OA obese (OA-ob:CM), OA-pre-obese (OA-Pob:CM), and mechanical stretch at either 0 %, 6 % or 10 % for 24 h. Differences in the mRNA levels of genes involved in extracellular matrix production, inflammation and secretory activity were measured.

    RESULTS: Despite the significant BMI differences between the OA-ob and OA-Pob groups, OA-Pob has more patients with underlying dyslipidaemia, and low-grade synovitis with higher levels of secreted proteins, CXCL8, COL4A1, CCL4, SPARC and FGF2 in OA-Pob:CM. All primary SFb exhibited anti-proliferative activity with both OA-CM. Mechanical stretch stimulated lubricin production in scope:SFb, higher TGFβ1 and COL1A1 expressions in scope-CD:SFb. OA-Pob:CM stimulated greater detrimental effects than the OA-ob:CM, with higher pro-inflammatory cytokines, IL1β, IL6, COX2 and proteases such as aggrecanases, ADAMTS4 and ADAMTS5, and lower ECM matrix, COL1A1 expressions in all SFb. OA-ob:SFb were unresponsive but expressed higher pro-inflammatory cytokines under OA-Pob:CM treatment.

    CONCLUSION: Both mechanical and inflammatory stressors regulate SFb molecular functions with heterogeneity in responses that are dependent on their pathological tissue of origins. While mechanical stretch promotes a favorable effect with enhanced lubricin production in scope:SFb and TGFβ1 and COL1A1 in scope-CD:SFb, the presence of excessively high OA-associated inflammatory mediators in OA-Pob:CM, predominantly SPARC, CXCL8 and FGF2 drive all SFb regardless of pathology, towards greater pro-inflammatory activities.

  7. Che Zain MS, Lee SY, Nasir NM, Fakurazi S, Shaari K
    Molecules, 2020 Nov 30;25(23).
    PMID: 33265992 DOI: 10.3390/molecules25235636
    Oil palm (Elaeis guineensis Jacq.) leaflets (OPLs) are one of the major agricultural by-products generated from the massive cultivation of Malaysian palm oil. This biomass is also reported to be of potential value based on its health-improving effects. By employing proton nuclear magnetic resonance (1H-NMR) spectroscopy combined with multivariate data analysis (MVDA), the metabolite profile of OPLs was characterized and correlated with their antioxidant and wound healing properties. Principal component analysis (PCA) classified four varieties of extracts, prepared using solvents ranging from polar to medium polarity, into three distinct clusters. Cumulatively, six flavonoids, eight organic acids, four carbohydrates, and an amine were identified from the solvent extracts. The more polar extracts, such as, the ethyl acetate-methanol, absolute methanol, and methanol-water, were richer in phytochemicals. Based on partial least square (PLS) analysis, the constituents in these extracts, such as (+)-catechin, (-)-epicatechin, orientin, isoorientin, vitexin, and isovitexin, were strongly correlated with the measured antioxidant activities, comprising ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide (NO) free radical scavenging activities, as well as with cell proliferation and migration activities. This study has provided crucial evidence on the importance of these natural antioxidant compounds on the wound healing properties of OPL.
  8. Friess DA, Yando ES, Abuchahla GMO, Adams JB, Cannicci S, Canty SWJ, et al.
    Curr Biol, 2020 02 24;30(4):R153-R154.
    PMID: 32097637 DOI: 10.1016/j.cub.2019.12.054
    Friess et al. discuss the results of conservation efforts for mangrove forests in recent years.
  9. Lee SY, Tang SJ, Rockey DC, Weinstein D, Lara L, Sreenarasimhaiah J, et al.
    Gastrointest Endosc, 2008 Jun;67(7):1076-81.
    PMID: 18384789 DOI: 10.1016/j.gie.2007.11.037
    Anticoagulation and antiplatelet medications may potentiate GI bleeding, and their use may lead to an increased need for a GI endoscopy. We hypothesized that there might be different practice patterns among international endoscopists.
  10. Promja S, Puenpa J, Achakulvisut T, Poovorawan Y, Lee SY, Athamanolap P, et al.
    Anal Chem, 2023 Jan 12.
    PMID: 36633573 DOI: 10.1021/acs.analchem.2c05112
    Since the declaration of COVID-19 as a pandemic in early 2020, multiple variants of the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) have been detected. The emergence of multiple variants has raised concerns due to their impact on public health. Therefore, it is crucial to distinguish between different viral variants. Here, we developed a machine learning web-based application for SARS-CoV-2 variant identification via duplex real-time polymerase chain reaction (PCR) coupled with high-resolution melt (qPCR-HRM) analysis. As a proof-of-concept, we investigated the platform's ability to identify the Alpha, Delta, and wild-type strains using two sets of primers. The duplex qPCR-HRM could identify the two variants reliably in as low as 100 copies/μL. Finally, the platform was validated with 167 nasopharyngeal swab samples, which gave a sensitivity of 95.2%. This work demonstrates the potential for use as automated, cost-effective, and large-scale viral variant surveillance.
  11. Higuchi T, Ishigooka J, Iyo M, Yeh CB, Ebenezer EG, Liang KY, et al.
    Asia Pac Psychiatry, 2019 Jun;11(2):e12352.
    PMID: 30950208 DOI: 10.1111/appy.12352
    INTRODUCTION: To evaluate efficacy and safety of lurasidone for the treatment of Asian patients with schizophrenia.

    METHODS: Patients with schizophrenia from Japan, South Korea, Malaysia, and Taiwan were randomly assigned to 6 weeks of double-blind treatment with 40 or 80 mg/d of lurasidone or placebo. The primary efficacy measure was change from baseline to week 6 on the Positive and Negative Syndrome Scale (PANSS) total score. Efficacy was evaluated using a mixed-model repeated-measures (MMRM) analysis in the modified intention-to-treat (mITT) population.

    RESULTS: On the basis of the analysis for the mITT population, the estimated difference score for lurasidone 40 and 80 mg/d vs placebo was -4.8 (P = 0.050) and -4.2 (P = 0.080). For the full intention-to-treat (ITT) population, the difference score for lurasidone 40 and 80 mg/d vs placebo was -5.8 (P = 0.017) and -4.2 (P = 0.043). The most frequent adverse events in the lurasidone 40 and 80 mg/d and placebo groups, respectively, were akathisia (7.3%, 10.4%, 3.3%), somnolence (6.0%, 2.6%, 0.7%), and vomiting (6.0%, 5.8%, 2.0%). The proportion of patients experiencing clinically significant weight gain (≥7%) was 5.3% for lurasidone 40 mg/d, 1.3% for 80 mg/d, and 1.4% for placebo. End point changes in metabolic parameters and prolactin were comparable for both lurasidone groups and placebo.

    CONCLUSIONS: In the ITT (but not the mITT) population, treatment with lurasidone was associated with significant improvement in the PANSS total score in patients with schizophrenia. Lurasidone was generally well tolerated with minimal impact on weight and metabolic parameters.

  12. Chan CYW, Lee SY, Ch'ng PY, Chung WH, Chiu CK, Hasan MS, et al.
    Spine (Phila Pa 1976), 2021 Jun 15;46(12):E663-E670.
    PMID: 33306608 DOI: 10.1097/BRS.0000000000003866
    STUDY DESIGN: Retrospective study.

    OBJECTIVE: To assess the learning curve of a dual attending surgeon strategy in severe adolescent idiopathic scoliosis patients.

    SUMMARY OF BACKGROUND DATA: The advantages of a dual attending surgeon strategy in improving the perioperative outcome in scoliosis surgery had been reported. However, the learning curve of this strategy in severe scoliosis had not been widely studied.

    METHODS: A total of 105 patients with adolescent idiopathic scoliosis with Cobb angle of 90° or greater, who underwent posterior spinal fusion using a dual attending surgeon strategy were recruited. Primary outcomes were operative time, total blood loss, allogeneic blood transfusion requirement, length of hospital stay from time of operation and perioperative complications. Cases were sorted chronologically into group 1: cases 1 to 35, group 2: cases 36 to 70, and group 3: case 71 to 105. Mean operative time (≤193.3 min), total blood loss (≤1612.2 mL), combination of both and allogeneic blood transfusion were the selected criteria for receiver operating characteristic analysis of the learning curve.

    RESULTS: The mean Cobb angle was 104.5° ± 12.3°. The operative time, total blood loss, and allogeneic blood transfusion requirement reduced significantly for group 1 (220.6 ± 54.8 min; 2011.3 ± 881.8 mL; 12 cases) versus group 2 (183.6 ± 36.7 min; 1481.6 ± 1035.5 mL; 3 cases) and group 1 versus group 3 (175.6 ± 38.4 min; 1343.7 ± 477.8 mL; 3 cases) (P 

  13. Reungwetwattana T, Cho BC, Lee KH, Pang YK, Fong CH, Kang JH, et al.
    J Thorac Oncol, 2023 Oct;18(10):1351-1361.
    PMID: 37702629 DOI: 10.1016/j.jtho.2023.06.016
    INTRODUCTION: Lazertinib is a third-generation central nervous system-penetrant tyrosine kinase inhibitor targeting mutant EGFR in NSCLC. Lazertinib exhibited improved efficacy versus gefitinib in the LASER301 study; this subset analysis compared lazertinib with gefitinib among Asian patients.

    METHODS: The phase 3 LASER301 study evaluated lazertinib efficacy and safety in treatment-naive patients with EGFR-mutated (exon 19 deletion or L858R) locally advanced or metastatic NSCLC. Patients were randomized one-to-one and received either lazertinib or gefitinib. The primary end point was investigator-assessed progression-free survival using Response Evaluation Criteria in Solid Tumors version 1.1. Secondary end points included overall survival, objective response rate, duration of response, and safety.

    RESULTS: Between February 13, 2020, and July 29, 2022, among 258 patients of Asian descent, the median progression-free survival was significantly longer with lazertinib than gefitinib (20.6 versus 9.7 mo; hazard ratio: 0.46; 95% confidence interval [CI]: 0.34-0.63, p < 0.001), and the benefit was consistent across predefined subgroups (exon 19 deletion, L858R, baseline central nervous system metastases). Objective response rate and disease control rates were similar between treatment groups. The median duration of response was 19.4 months (95% CI: 16.6-24.9) versus 9.6 months (95% CI: 6.9-12.4) in the lazertinib versus gefitinib group. Adverse event rates in Asian patients were comparable with the overall LASER301 population. Adverse events leading to discontinuation in the lazertinib and gefitinib groups were 13% and 12%, respectively.

    CONCLUSIONS: In LASER301, efficacy and safety results in Asian patients were consistent with the overall population. Lazertinib exhibited better efficacy than gefitinib in Asian patients with a tolerable safety profile.

  14. Lee SY, Shaari K
    Phytochem Anal, 2021 Sep 07.
    PMID: 34490671 DOI: 10.1002/pca.3084
    INTRODUCTION: Stevia is known for its sweet taste, attributed to the presence of steviol glycosides. Although reports on the dynamic changes of steviol glycosides during development of stevia are available, the data are mainly focused on stevioside and rebaudioside A. Information concerning the comprehensive metabolite profile of stevia in relation to different developmental stages is still lacking.

    OBJECTIVE: This study investigated the metabolite changes along the developmental stages of a local stevia cultivar.

    METHODOLOGY: Stevia leaves were harvested at 4 different developmental stages (early vegetative, late vegetative, budding, and flowering). Samples were then subjected to LC-MS metabolomics analysis to determine the metabolite variations.

    RESULTS: A total of 55 metabolites, comprising phenolic acids, flavonoids, and terpenoids were identified by MS/MS analysis of the stevia leaf extracts, revealing a metabolite profile which was comparatively similar with those of cultivars grown in other countries. PLS-DA differentiated the early vegetative stage stevia leaf samples from those of the later stages by higher content of phenolic acids. The leaf metabolomes of the later 3 stages (late vegetative, budding, and flowering) were collectively richer in flavonoids. Meanwhile, the content of steviol glycosides is highest during the late vegetative and budding stages.

    CONCLUSION: The present study provided, for the first time, a general overview of the metabolite variations with regard to the different developmental stages of stevia. The information may facilitate decision making of suitable harvesting times for higher yields of steviol glycosides or a more balanced metabolite profile in terms of pharmacologically useful metabolites.

  15. Lee SY, Soh KL, Japar S, Ong SL, Soh KG, Tsujita Y
    Belitung Nurs J, 2021;7(5):361-369.
    PMID: 37496510 DOI: 10.33546/bnj.1682
    BACKGROUND: The transition process of migration to work abroad can be challenging and, depending on how it is handled, can impact the job satisfaction level of these foreign-educated nurses. A clear understanding of migrant nurses' job satisfaction is critical for effective translation of nursing practice across the health systems and cultures.

    OBJECTIVE: This study examined the job satisfaction of the foreign-educated nurses in Malaysia, which includes the job satisfaction dimensions and the significant difference between sociodemographic status and job satisfaction.

    METHODS: A cross-sectional survey of 102 foreign-educated nurses working in private hospitals, clinics, hemodialysis centers, nursing homes, and private homes in Malaysia was conducted from September 2017 to March 2018. Data were collected using a structured questionnaire. Descriptive statistics, Mann-Whitney U, and Kruskal Wallis tests were used to analyze the data.

    RESULTS: The study revealed that the participants had a median satisfaction score of 22 (IQR = 19 to 24). Serving the sick and needy and participants' self-respect were the highest satisfaction dimensions among the participants (Median = 3, IQR = 3 to 3). Moreover, the job satisfaction was significantly higher for registered foreign-educated nurses (mean rank = 62.5) than for unregistered foreign-educated nurses (mean rank = 48.65) when working in other countries (p = 0.02). Indian nurses (mean rank = 60.36) also expressed higher satisfaction in terms of working in other countries than Filipino nurses (mean rank = 46.88; p = 0.02). In addition, positive relationships with colleagues and superiors led to higher satisfaction among Indian nurses (mean rank = 61.02) than among Filipino nurses (mean rank = 47.24; p = 0.04). The job satisfaction of male foreign-educated nurses was significantly higher than their female counterparts in terms of self-respect, relationship with fellow nurses and superiors, working in other countries, career development, and ease of finding employment (p < 0.05).

    CONCLUSION: The overall job satisfaction among the foreign-educated nurses in Malaysia is high, mainly when serving the sick and needy, and their degree of self-respect. Understanding job satisfaction among foreign-educated nurses in Malaysia enables the management team to develop effective strategies for addressing nursing shortages and improving the quality of patient care.

  16. Teo SY, Yew MY, Lee SY, Rathbone MJ, Gan SN, Coombes AGA
    J Pharm Sci, 2017 01;106(1):377-384.
    PMID: 27522920 DOI: 10.1016/j.xphs.2016.06.028
    Phenytoin-loaded alkyd nanoemulsions were prepared spontaneously using the phase inversion method from a mixture of novel biosourced alkyds and Tween 80 surfactant. Exposure of human adult keratinocytes (HaCaT cells) for 48 h to alkyd nanoemulsions producing phenytoin concentrations of 3.125-200 μg/mL resulted in relative cell viability readings using tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide of 100% confirming nontoxicity and suggesting cell proliferation activity. Phenytoin-loaded alkyd nanoemulsions generally resulted in higher mean cell viability compared with equivalent concentration of phenytoin solutions, suggesting that the nanoemulsions provided a controlled-release property that maintained the optimum phenytoin level for keratinocyte growth. HaCaT cell proliferation, measured by 5-bromo-2-deoxyuridine uptake, was found to increase following exposure to increasing phenytoin concentration from 25 to 50 μg/mL in solution or encapsulated in nanoemulsions but declined at a drug concentration of 100 μg/mL. An in vitro cell monolayer wound scratch assay revealed that phenytoin solution or nanoemulsions producing 50 μg/mL phenytoin concentration resulted in 75%-82% "scratch closure" after 36 h, similar to medium containing 10% fetal bovine serum as a cell growth promoter. These findings indicate that phenytoin-loaded alkyd nanoemulsions show potential for promoting topical wound healing through enhanced proliferation of epidermal cells.
  17. Syazwan SA, Lee SY, Sajap AS, Lau WH, Omar D, Mohamed R
    Biology (Basel), 2021 Mar 25;10(4).
    PMID: 33806225 DOI: 10.3390/biology10040263
    Metarhizium anisopliae (Metchnikoff) Sorokin, a pathogenic fungus to insects, infects the subterranean termite, Coptotermes curvignathus Holmgren, a devastating pest of plantation trees in the tropics. Electron microscopy and proteomics were used to investigate the infection and developmental process of M. anisopliae in C. curvignathus. Fungal infection was initiated by germ tube penetration through the host's cuticle as observed at 6 h post-inoculation (PI), after which it elongated into the host's integumental tissue. The colonization process continued as seen from dissemination of blastospores in the hemocoel at 96 h PI. At this time point, the emergent mycelia had mummified the host and forty-eight hours later, new conidia were dispersed on the termites' body surface. Meanwhile, hyphal bodies were observed in abundance in the intercellular space in the host's body. The proteomes of the pathogen and host were isolated separately using inoculated termite samples withdrawn at each PI-time point and analyzed in two-dimensional electrophoresis (2-DE) gels. Proteins expressed in termites showed evidence of being related to cell regulation and the immune response, while those expressed in M. anisopliae, to transportation and fungal virulence. This study provides new information on the interaction between termites and its entomopathogen, with potential utilization for developing future biopesticide to control the termite population.
  18. Sankaran R, Show PL, Lee SY, Yap YJ, Ling TC
    Bioresour Technol, 2018 Feb;250:306-316.
    PMID: 29174909 DOI: 10.1016/j.biortech.2017.11.050
    Liquid Biphasic Flotation (LBF) is an advanced recovery method that has been effectively applied for biomolecules extraction. The objective of this investigation is to incorporate the fermentation and extraction process of lipase from Burkholderia cepacia using flotation system. Initial study was conducted to compare the performance of bacteria growth and lipase production using flotation and shaker system. From the results obtained, bacteria shows quicker growth and high lipase yield via flotation system. Integration process for lipase separation was investigated and the result showed high efficiency reaching 92.29% and yield of 95.73%. Upscaling of the flotation system exhibited consistent result with the lab-scale which are 89.53% efficiency and 93.82% yield. The combination of upstream and downstream processes in a single system enables the acceleration of product formation, improves the product yield and facilitates downstream processing. This integration system demonstrated its potential for biomolecules fermentation and separation that possibly open new opportunities for industrial production.
  19. Che Zain MS, Yeoh JX, Lee SY, Afzan A, Shaari K
    Antioxidants (Basel), 2021 Nov 12;10(11).
    PMID: 34829674 DOI: 10.3390/antiox10111802
    Huge quantities of oil palm (Elaeis guineensis Jacq.) leaves (OPL) are generated as agricultural biomass from oil palm plantations. OPL are known to contain significant amounts of flavonoids. For maximal exploitation of these valuable antioxidant compounds, an innovative and sustainable extraction method employing natural deep eutectic solvents (NaDES) combined with ultrasonic assisted extraction was developed. Various NaDES composed of choline chloride as the hydrogen bond donor (HBD) and 1,2 propanediol (PD), 1,4 butanediol (BD), glycerol (GLY), glucose (GLU), maltose (MAL), and lactic acid (LA) as the hydrogen bond acceptor (HBA) were synthesized. The influence of these compositions, the methods of their synthesis, molar ratios, and water contents on their capacity to extract flavonoids from OPL was evaluated. Based on the results, it was found that methods which incorporate a heating step produced NaDES with the best capacity to extract OPL flavonoids. These thermal methods combined with molar ratios of 1:3 or 1:4 and water contents of 17 to 50% were found to be the optimal conditions for preparing NaDES, specifically when applied to the PD, BD, and GLY NaDES. Subsequently, UHPLC-UV/PDA-MS/MS analysis revealed NaDES extracts recovered by macroporous adsorption resin XAD7HP were able to optimally extract at least twelve luteolin and apigenin derivatives in OPL NaDES extracts prepared from glycerol and 1,4-butanediol demonstrated better and comparable efficiency as aqueous methanol in extracting flavonoids from OPL. The in vitro studies of antioxidant and wound healing properties supported these findings by exhibiting good free radical scavenging, cell proliferation, and migration activities. Additionally, the NaDES extracts also showed non-cytotoxicity effects at 1000 µg/mL and below on 3T3 fibroblast cells. Results of the study showed that NaDES could be a promising eco-friendly green solvent to extract bioactive OPL flavonoids that have great potential for applications as wound healing agents.
  20. Wen WX, Allen J, Lai KN, Mariapun S, Hasan SN, Ng PS, et al.
    J Med Genet, 2018 02;55(2):97-103.
    PMID: 28993434 DOI: 10.1136/jmedgenet-2017-104947
    BACKGROUND: Genetic testing for BRCA1 and BRCA2 is offered typically to selected women based on age of onset and family history of cancer. However, current internationally accepted genetic testing referral guidelines are built mostly on data from cancer genetics clinics in women of European descent. To evaluate the appropriateness of such guidelines in Asians, we have determined the prevalence of germ line variants in an unselected cohort of Asian patients with breast cancer and healthy controls.

    METHODS: Germ line DNA from a hospital-based study of 2575 unselected patients with breast cancer and 2809 healthy controls were subjected to amplicon-based targeted sequencing of exonic and proximal splice site junction regions of BRCA1 and BRCA2 using the Fluidigm Access Array system, with sequencing conducted on a Illumina HiSeq2500 platform. Variant calling was performed with GATK UnifiedGenotyper and were validated by Sanger sequencing.

    RESULTS: Fifty-five (2.1%) BRCA1 and 66 (2.6%) BRCA2 deleterious mutations were identified among patients with breast cancer and five (0.18%) BRCA1 and six (0.21%) BRCA2 mutations among controls. One thousand one hundred and eighty-six (46%) patients and 97 (80%) carriers fulfilled the National Comprehensive Cancer Network guidelines for genetic testing.

    CONCLUSION: Five per cent of unselected Asian patients with breast cancer carry deleterious variants in BRCA1 or BRCA2. While current referral guidelines identified the majority of carriers, one in two patients would be referred for genetic services. Given that such services are largely unavailable in majority of low-resource settings in Asia, our study highlights the need for more efficient guidelines to identify at-risk individuals in Asia.

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