Displaying publications 1 - 20 of 45 in total

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  1. Ong SQ, Dawood MM, Rahman H, Alias MF, Moideen MA, Lee PC, et al.
    MethodsX, 2024 Jun;12:102563.
    PMID: 38328504 DOI: 10.1016/j.mex.2024.102563
    Mosquito-borne diseases pose a significant threat in many Southeast Asian countries, particularly through the sylvatic cycle, which has a wildlife reservoir in forests and rural areas. Studying the composition and diversity of vectors and pathogen transmission is especially challenging in forests and rural areas due to their remoteness, limited accessibility, lack of power, and underdeveloped infrastructure. This study is based on the WHO mosquito sampling protocol, modifies technical details to support mosquito collection in difficult-to-access and resource-limited areas. Specifically, we describe the procedure for using rechargeable lithium batteries and solar panels to power the mosquito traps, demonstrate a workflow for processing and storing the mosquitoes in a -20 °C freezer, data management tools including microclimate data, and quality assurance processes to ensure the validity and reliability of the results. A pre- and post-test was utilized to measure participant knowledge levels. Additional research is needed to validate this protocol for monitoring vector-borne diseases in hard-to-reach areas within other countries and settings.
  2. Rosenthal VD, Yin R, Myatra SN, Divatia JV, Biswas SK, Shrivastava AM, et al.
    J Vasc Access, 2024 Mar 27.
    PMID: 38539085 DOI: 10.1177/11297298241242163
    BACKGROUND: Central line-associated bloodstream infection (CLABSI) rates in intensive care units (ICUs) across Latin America exceed those in high-income countries significantly.

    METHODS: We implemented the INICC multidimensional approach, incorporating an 11-component bundle, in 122 ICUs spanning nine Asian countries. We computed the CLABSI rate using the CDC/NSHN definition and criteria. The CLABSI rate per 1000 CL-days was calculated at baseline and throughout different phases of the intervention, including the 2nd month, 3rd month, 4-16 month, and 17-29 month periods. A two-sample t-test was employed to compare baseline CLABSI rates with intervention rates. Additionally, we utilized a generalized linear mixed model with a Poisson distribution to analyze the association between exposure and outcome.

    RESULTS: A total of 124,946 patients were hospitalized over 717,270 patient-days, with 238,595 central line (CL)-days recorded. The rates of CLABSI per 1000 CL-days significantly decreased from 16.64 during the baseline period to 6.51 in the 2nd month (RR = 0.39; 95% CI = 0.36-0.42; p 

  3. Rosenthal VD, Yin R, Abbo LM, Lee BH, Rodrigues C, Myatra SN, et al.
    Am J Infect Control, 2024 Jan;52(1):54-60.
    PMID: 37499758 DOI: 10.1016/j.ajic.2023.07.007
    BACKGROUND: Identify urinary catheter (UC)-associated urinary tract infections (CAUTI) incidence and risk factors (RF) in 235 ICUs in 8 Asian countries: India, Malaysia, Mongolia, Nepal, Pakistan, the Philippines, Thailand, and Vietnam.

    METHODS: From January 1, 2014, to February 12, 2022, we conducted a prospective cohort study. To estimate CAUTI incidence, the number of UC days was the denominator, and CAUTI was the numerator. To estimate CAUTI RFs, we analyzed 11 variables using multiple logistic regression.

    RESULTS: 84,920 patients hospitalized for 499,272 patient days acquired 869 CAUTIs. The pooled CAUTI rate per 1,000 UC-days was 3.08; for those using suprapubic-catheters (4.11); indwelling-catheters (2.65); trauma-ICU (10.55), neurologic-ICU (7.17), neurosurgical-ICU (5.28); in lower-middle-income countries (3.05); in upper-middle-income countries (1.71); at public-hospitals (5.98), at private-hospitals (3.09), at teaching-hospitals (2.04). The following variables were identified as CAUTI RFs: Age (adjusted odds ratio [aOR] = 1.01; 95% CI = 1.01-1.02; P 

  4. Rosenthal VD, Jin Z, Rodrigues C, Myatra SN, Divatia JV, Biswas SK, et al.
    Infect Control Hosp Epidemiol, 2023 Aug;44(8):1261-1266.
    PMID: 36278508 DOI: 10.1017/ice.2022.245
    OBJECTIVE: To identify risk factors for mortality in intensive care units (ICUs) in Asia.

    DESIGN: Prospective cohort study.

    SETTING: The study included 317 ICUs of 96 hospitals in 44 cities in 9 countries of Asia: China, India, Malaysia, Mongolia, Nepal, Pakistan, Philippines, Sri Lanka, Thailand, and Vietnam.

    PARTICIPANTS: Patients aged >18 years admitted to ICUs.

    RESULTS: In total, 157,667 patients were followed during 957,517 patient days, and 8,157 HAIs occurred. In multiple logistic regression, the following variables were associated with an increased mortality risk: central-line-associated bloodstream infection (CLABSI; aOR, 2.36; P < .0001), ventilator-associated event (VAE; aOR, 1.51; P < .0001), catheter-associated urinary tract infection (CAUTI; aOR, 1.04; P < .0001), and female sex (aOR, 1.06; P < .0001). Older age increased mortality risk by 1% per year (aOR, 1.01; P < .0001). Length of stay (LOS) increased mortality risk by 1% per bed day (aOR, 1.01; P < .0001). Central-line days increased mortality risk by 2% per central-line day (aOR, 1.02; P < .0001). Urinary catheter days increased mortality risk by 4% per urinary catheter day (aOR, 1.04; P < .0001). The highest mortality risks were associated with mechanical ventilation utilization ratio (aOR, 12.48; P < .0001), upper middle-income country (aOR, 1.09; P = .033), surgical hospitalization (aOR, 2.17; P < .0001), pediatric oncology ICU (aOR, 9.90; P < .0001), and adult oncology ICU (aOR, 4.52; P < .0001). Patients at university hospitals had the lowest mortality risk (aOR, 0.61; P < .0001).

    CONCLUSIONS: Some variables associated with an increased mortality risk are unlikely to change, such as age, sex, national economy, hospitalization type, and ICU type. Some other variables can be modified, such as LOS, central-line use, urinary catheter use, and mechanical ventilation as well as and acquisition of CLABSI, VAE, or CAUTI. To reduce mortality risk, we shall focus on strategies to reduce LOS; strategies to reduce central-line, urinary catheter, and mechanical ventilation use; and HAI prevention recommendations.

  5. Ali U, Zainal M, Zainol Z, Tai CW, Tang SF, Lee PC, et al.
    Malays J Pathol, 2023 Aug;45(2):215-227.
    PMID: 37658531
    INTRODUCTION: Acute respiratory infection (ARI) contributes to significant mortality and morbidity worldwide and is usually caused by a wide range of respiratory pathogens. This study aims to describe the performance of QIAstat-Dx® Respiratory Panel V2 (RP) and RespiFinder® 2SMART assays for respiratory pathogens detection.

    MATERIALS AND METHODS: A total of 110 nasopharyngeal swabs (NPS) were collected from children aged one month to 12 years old who were admitted with ARI in UKMMC during a one-year period. The two qPCR assays were conducted in parallel.

    RESULTS: Ninety-seven samples (88.2%) were positive by QIAstat-Dx RP and 86 (78.2%) by RespiFinder assay. The overall agreement on both assays was substantial (kappa value: 0.769) with excellent concordance rate of 96.95%. Using both assays, hRV/EV, INF A/H1N1 and RSV were the most common pathogens detected. Influenza A/H1N1 infection was significantly seen higher in older children (age group > 60 months old) (53.3%, p-value < 0.05). Meanwhile, RSV and hRV/EV infection were seen among below one-year-old children. Co-infections by two to four pathogens were detected in 17 (17.5%) samples by QIAstat-Dx RP and 12 (14%) samples by RespiFinder, mainly involving hRV/EV. Bacterial detection was observed only in 5 (4.5%) and 6 (5.4%) samples by QIAstat-Dx RP and RespiFinder, respectively, with Mycoplasma pneumoniae the most common detected.

    CONCLUSION: The overall performance of the two qPCR assays was comparable and showed excellent agreement. Both detected various clinically important respiratory pathogens in a single test with simultaneous multiple infection detection. The use of qPCR as a routine diagnostic test can improve diagnosis and management.

  6. Rosenthal VD, Yin R, Rodrigues C, Myatra SN, Divatia JV, Biswas SK, et al.
    Am J Infect Control, 2023 Jul;51(7):751-757.
    PMID: 36400318 DOI: 10.1016/j.ajic.2022.11.005
    BACKGROUND: Ventilator associated pneumonia (VAP) rates in Asia are several times above those of US. The objective of this study is to identify VAP risk factors.

    METHODS: We conducted a prospective cohort study, between March 27, 2004 and November 2, 2022, in 279 ICUs of 95 hospitals in 44 cities in 9 Asian countries (China, India, Malaysia, Mongolia, Nepal, Pakistan, Philippines, Sri Lanka, Thailand, Vietnam).

    RESULTS: 153,717 patients, followed during 892,996 patient-days, acquired 3,369 VAPs. We analyzed 10 independent variables. Using multiple logistic regression we identified following independent VAP RFs= Age, rising VAP risk 1% per year (aOR=1.01; 95%CI=1.00-1.01, P

  7. Chong ETJ, Chiang C, Png KK, Abidueva E, Zaitseva S, Sun C, et al.
    Data Brief, 2023 Feb;46:108877.
    PMID: 36691562 DOI: 10.1016/j.dib.2022.108877
    The Streptomyces cavourensis strain 2BA6PGT was isolated from sediment from the bottom of the salt lake Verkhnee Beloe (Buryatia, Russia). This strain's 7,651,223 bp complete genome has a high G + C content of 72.1% and consists of 7,069 coding sequences and 315 subsystems. The 16S ribosomal RNA of isolate 2BA6PGT was most closely related to Streptomyces cavourensis strain NBRC 13026T (98.91% identity), followed by Streptomyces bacillaris strain ATCC 15855T (95.36%), Streptomyces rhizosphaericola strain 1AS2cT (94.68%), and Streptomyces pluricolorescens strain JCM 4602T (86.75%). These comparisons were supported by pairwise comparisons using average nucleotide identity (ANI) and DNA-DNA hybridization analysis. This is the first complete genome reported on Streptomyces cavourensis isolated from sediment from the bottom of the salt lake Verkhnee Beloe. The complete genome sequence has been deposited at the NCBI GenBank with an accession number CP101140.
  8. Ng JW, Chong ETJ, Lee PC
    Curr Pharm Biotechnol, 2022 Jan 14.
    PMID: 35034591 DOI: 10.2174/1389201023666220114162347
    Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and recently has become a serious global pandemic. Age, gender, and comorbidities are known to be common risk factors for severe COVID-19 but are not enough to fully explain the magnitude of their effect on the risk of severity of the disease. Single nucleotide polymorphisms (SNPs) in several genes have been reported as a genetic factor contributing to COVID-19 severity. This comprehensive review focuses on the association between SNPs in four important genes and COVID-19 severity in a global aspect. We discuss a total of 39 SNPs in this review: five SNPs in the ABO gene, nine SNPs in the angiotensin-converting enzyme 2 (ACE2) gene, 19 SNPs in the transmembrane protease serine 2 (TMPRSS2) gene, and six SNPs in the toll-like receptor 7 (TLR7) gene. These SNPs data could assist in monitoring an individual's risk of severe COVID-19 disease, and therefore personalized management and pharmaceutical treatment could be planned in COVID-19 patients.
  9. Khan R, Shah MD, Shah L, Lee PC, Khan I
    Front Nutr, 2022;9:1031935.
    PMID: 36407542 DOI: 10.3389/fnut.2022.1031935
    Bacterial polysaccharides are unique due to their higher purity, hydrophilic nature, and a finer three-dimensional fibrous structure. Primarily, these polymers provide protection, support, and energy to the microorganism, however, more recently several auxiliary properties of these biopolymers have been unmasked. Microbial polysaccharides have shown therapeutic abilities against various illnesses, augmented the healing abilities of the herbal and Western medicines, improved overall health of the host, and have exerted positive impact on the growth of gut dwelling beneficial bacteria. Specifically, the review is discussing the mechanism through which bacterial polysaccharides exert anti-inflammatory, antioxidant, anti-cancer, and anti-microbial properties. In addition, they are holding promising application in the 3D printing. The review is also discussing a perspective about the metagenome-based screening of polysaccharides, their integration with other cutting-edge tools, and synthetic microbiome base intervention of polysaccharides as a strategy for prebiotic intervention. This review has collected interesting information about the bacterial polysaccharides from Google Scholar, PubMed, Scopus, and Web of Science databases. Up to our knowledge, this is the first of its kind review article that is summarizing therapeutic, prebiotics, and commercial application of bacterial polysaccharides.
  10. Phneh KY, Chong ETJ, Shah SS, Chia YK, Daud DMBA, Jalil E, et al.
    J Mol Neurosci, 2021 Oct;71(10):2085-2094.
    PMID: 33479916 DOI: 10.1007/s12031-021-01795-w
    The rs9958947 single nucleotide polymorphism (SNP) resides in the promoter region of the lipase G (LIPG) gene. This newly discovered SNP increases the risk of stroke in some Asian populations, including Chinese and Korean populations. Stroke is one of the top 5 leading causes of death in Malaysia, so it is of interest to investigate whether this SNP is associated with stroke risk in the Malaysian population. Therefore, this study investigates this association through a case-control study on a Malaysian population along with a comprehensive meta-analysis. Genotyping of LIPG rs9958947 SNP was performed for 241 Malaysians using real-time polymerase chain reaction, and the odds ratios (OR) with 95% confidence intervals were calculated. The meta-analysis was conducted using the software Comprehensive Meta-Analysis ver. 2.2.064. A p value less than 0.05 was considered statistically significant. We observed that the mean age of Malaysian stroke patients was less than that of stroke patients from Korea and China. The meta-analysis showed that the LIPG rs9958947 SNP was significantly associated with an increased risk of ischemic stroke in Asian populations (dominant (CC vs. CT + TT): OR = 1.45, p  0.05) and blood lipid levels.
  11. Puah PY, Moh PY, Sipaut CS, Lee PC, How SE
    Polymers (Basel), 2021 Sep 26;13(19).
    PMID: 34641106 DOI: 10.3390/polym13193290
    Graphene oxide (GO) is extensively studied as a template material for mesenchymal stem cell application due to its two-dimensional nature and unique functionalization chemistries. Herein, a new type of peptide-conjugated multilayer graphene oxide (peptide/m-GO film) was fabricated and used as biomaterial for culturing human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs). The characterization of the peptide/m-GO films was performed, and the biocompatibility of the WJ-MSCs on the peptide/m-GO films was investigated. The results demonstrated that the peptide conjugate on the m-GO film did not hamper the normal growth of WJ-MSCs but supported the growth of WJ-MSCs after the 6-day culture period. In addition, the osteogenic differentiation of WJ-MSCs on the peptide/m-GO films was enhanced as compared with the parent m-GO film. Therefore, such peptide-conjugated m-GO films could provide a highly biocompatible and multifunctional 2D material to tailor the potential application of WJ-MSCs in bone tissue regeneration.
  12. Azazi A, Haron FN, Chua KH, Lim YAL, Lee PC, Chew CH
    Trop Biomed, 2021 Sep 01;38(3):265-275.
    PMID: 34362869 DOI: 10.47665/tb.38.3.067
    Malaria caused by Plasmodium knowlesi species has become a public health concern, especially in Malaysia. Plasmodium knowlesi parasite which originates from the macaque species, infects human through the bite of the Anopheles mosquitoes. Research on malaria vaccine has been a continuous effort to eradicate the malaria infection, yet there is no vaccine against P. knowlesi malaria to date. Apical membrane antigen 1 (AMA1) is a unique surface protein of all apicomplexan parasites that plays a crucial role in parasite-host cell invasion and thus has been a long-standing malaria vaccine candidate. The selection of protective epitopes in silico has led to significant advances in the design of the vaccine. The present study aimed to employ bioinformatics tools to predict the potential immunogenic B- and T-cell epitopes in designing malaria vaccine targeting P. knowlesi AMA1 (PkAMA1). B-cell epitopes were predicted using four bioinformatics tools, i.e., BepiPred, ABCpred, BcePred, and IEDB servers whereas T-cell epitopes were predicted using two bioinformatics servers, i.e., NetMHCpan4.1 and NetMHCIIpan-4.0 targeting human major histocompatibility complex (MHC) class I and class II molecules, respectively. The antigenicity of the selected epitopes computed by both B- and T-cell predictors were further analyzed using the VaxiJen server. The results demonstrated that PkAMA1 protein encompasses multi antigenic regions that have the potential for the development of multi-epitope vaccine. Two B- and T-cell epitopes consensus regions, i.e., NSGIRIDLGEDAEVGNSKYRIPAGKCP (codons 28-54) and KTHAASFVIAEDQNTSY RHPAVYDEKNKT (codons 122-150) at domain I (DI) of PkAMA1 were reported. Advancement of bioinformatics in characterization of the target protein may facilitate vaccine development especially in vaccine design which is costly and cumbersome process. Thus, comprehensive B-cell and T-cell epitope prediction of PkAMA1 offers a promising pipeline for the development and design of multi-epitope vaccine against P. knowlesi.
  13. Samransamruajkit R, Wong JJ, Smathakane C, Anantasit N, Sunkonkit K, Ong J, et al.
    Pediatr Crit Care Med, 2021 08 01;22(8):713-721.
    PMID: 33729727 DOI: 10.1097/PCC.0000000000002680
    OBJECTIVES: Pediatric sepsis remains a major health problem and is a leading cause of death and long-term disability worldwide. This study aims to characterize epidemiologic, therapeutic, and outcome features of pediatric severe sepsis and septic shock in three Asian countries.

    DESIGN: A multicenter retrospective study with longitudinal clinical data over 1, 6, 24, 48, and 72 hours of PICU admission. The primary outcome was PICU mortality. Multivariable logistic regression analysis was used to identify factors at PICU admission that were associated with mortality.

    SETTING: Nine multidisciplinary PICUs in three Asian countries.

    PATIENTS: Children with severe sepsis or septic shock admitted to the PICU from January to December 2017.

    INTERVENTION: None.

    MEASUREMENT AND MAIN RESULTS: A total of 271 children were included in this study. Median (interquartile range) age was 4.2 years (1.3-10.8 yr). Pneumonia (77/271 [28.4%]) was the most common source of infection. Majority of patients (243/271 [90%]) were resuscitated within the first hour, with fluid bolus (199/271 [73.4%]) or vasopressors (162/271 [59.8%]). Fluid resuscitation commonly took the form of normal saline (147/199 [74.2%]) (20 mL/kg [10-20 mL/kg] over 20 min [15-30 min]). The most common inotrope used was norepinephrine 81 of 162 (50.0%). Overall PICU mortality was 52 of 271 (19.2%). Improved hemodynamic variables (e.g., heart rate, blood pressure, and arterial lactate) were seen in survivors within 6 hours of admission as compared to nonsurvivors. In the multivariable model, admission severity score was associated with PICU mortality.

    CONCLUSIONS: Mortality from pediatric severe sepsis and septic shock remains high in Asia. Consistent with current guidelines, most of the children admitted to these PICUs received fluid therapy and inotropic support as recommended.

  14. Goh XT, Lim YAL, Lee PC, Nissapatorn V, Chua KH
    Mol Biochem Parasitol, 2021 07;244:111390.
    PMID: 34087264 DOI: 10.1016/j.molbiopara.2021.111390
    The present study aimed to examine the genetic diversity of human malaria parasites (i.e., P. falciparum, P. vivax and P. knowlesi) in Malaysia and southern Thailand targeting the 19-kDa C-terminal region of Merozoite Surface Protein-1 (MSP-119). This region is essential for the recognition and invasion of erythrocytes and it is considered one of the leading candidates for asexual blood stage vaccines. However, the genetic data of MSP-119 among human malaria parasites in Malaysia is limited and there is also a need to update the current sequence diversity of this gene region among the Thailand isolates. In this study, genomic DNA was extracted from 384 microscopy-positive blood samples collected from patients who attended the hospitals or clinics in Malaysia and malaria clinics in Thailand from the year 2008 to 2016. The MSP-119 was amplified using PCR followed by bidirectional sequencing. DNA sequences identified in the present study were subjected to Median-joining network analysis with sequences of MSP-119 obtained from GenBank. DNA sequence analysis revealed that PfMSP-119 of Malaysian and Thailand isolates was not genetically conserved as high number of haplotypes were detected and positive selection was prevalent in PfMSP-119, hence questioning its suitability to be used as a vaccine candidate. A novel haplotype (Q/TNG/L) was also detected in Thailand P. falciparum isolate. In contrast, PvMSP-119 was highly conserved, however for the first time, a non-synonymous substitution (A1657S) was reported among Malaysian isolates. As for PkMSP-119, the presence of purifying selection and low nucleotide diversity indicated that it might be a potential vaccine target for P. knowlesi.
  15. Wong JJM, Abbas Q, Chuah SL, Malisie RF, Pon KM, Katsuta T, et al.
    Am J Trop Med Hyg, 2021 Jun 15;105(2):413-420.
    PMID: 34129517 DOI: 10.4269/ajtmh.21-0299
    There is a scarcity of data regarding coronavirus disease 2019 (COVID-19) infection in children from southeast and south Asia. This study aims to identify risk factors for severe COVID-19 disease among children in the region. This is an observational study of children with COVID-19 infection in hospitals contributing data to the Pediatric Acute and Critical Care COVID-19 Registry of Asia. Laboratory-confirmed COVID-19 cases were included in this registry. The primary outcome was severity of COVID-19 infection as defined by the World Health Organization (WHO) (mild, moderate, severe, or critical). Epidemiology, clinical and laboratory features, and outcomes of children with COVID-19 are described. Univariate and multivariable logistic regression models were used to identify risk factors for severe/critical disease. A total of 260 COVID-19 cases from eight hospitals across seven countries (China, Japan, Singapore, Malaysia, Indonesia, India, and Pakistan) were included. The common clinical manifestations were similar across countries: fever (64%), cough (39%), and coryza (23%). Approximately 40% of children were asymptomatic, and overall mortality was 2.3%, with all deaths reported from India and Pakistan. Using the multivariable model, the infant age group, presence of comorbidities, and cough on presentation were associated with severe/critical COVID-19. This epidemiological study of pediatric COVID-19 infection demonstrated similar clinical presentations of COVID-19 in children across Asia. Risk factors for severe disease in children were age younger than 12 months, presence of comorbidities, and cough at presentation. Further studies are needed to determine whether differences in mortality are the result of genetic factors, cultural practices, or environmental exposures.
  16. Goh LPW, Mahmud F, Lee PC
    Data Brief, 2021 Jun;36:107128.
    PMID: 34095378 DOI: 10.1016/j.dib.2021.107128
    The genome data of Streptomyces sp. FH025 comprised of 8,381,474 bp with a high GC content of 72.51%. The genome contains 7035 coding sequences spanning 1261 contigs. Streptomyces sp. FH025 contains 57 secondary metabolite gene clusters including polyketide synthase, nonribosomal polyketide synthase and other biosynthetic pathways such as amglyccycl, butyrolactone, terpenes, siderophores, lanthipeptide-class-iv, and ladderane. 16S rRNA analysis of Streptomyces sp. FH025 is similar to the Streptomyces genus. This whole genome project has been deposited at NCBI under the accession JAFLNG000000000.
  17. Teoh CP, Lavin P, Najimudin N, Lee PC, Iancu L, Purcarea C, et al.
    Microbiol Resour Announc, 2021 Feb 25;10(8).
    PMID: 33632855 DOI: 10.1128/MRA.00063-21
    Here, we report the draft genome sequence of Flavobacterium sp. strain PL002, isolated from Antarctic Porphyra algae. The 4,299,965-bp genome sequence is assembled into 170 contigs, has 32.92% GC content, and 3,734 predicted genes.
  18. Balan WS, Janaun J, Chung CH, Semilin V, Zhu Z, Haywood SK, et al.
    J Hazard Mater, 2021 02 15;404(Pt B):124092.
    PMID: 33091694 DOI: 10.1016/j.jhazmat.2020.124092
    In this study, carbon-silica based acid catalysts derived from rice husks (RH) were successfully synthesised using microwave (MW) technology. The results showed that MW sulphonation produced Sulphur (S) content of 17.2-18.5 times higher than in raw RH. Fourier-transform Infrared Spectroscopy (FTIR) showed peak at 1035 cm-1 which corresponded to O˭S˭O stretching of sulphonic (-SO3H) group. XRD showed sulfonated RH catalysts (SRHCs) have amorphous structure, and through SEM, broadening of the RH voids and also formation of pores is observed. RH600 had the highest surface area of 14.52 m2/g. SRHCs showed high catalytic activity for esterification of oleic acid with methanol with RH600 had the highest initial formation rate (6.33 mmolL-1min-1) and yield (97%). The reusability of the catalyst showed gradually dropped yield of product for every recycle, which might be due to leaching of -SO3H. Finally, esterification of oil recovered from palm oil mill effluent (POME) with methanol achieved a conversion of 87.3% free fatty acids (FFA) into fatty acid methyl esters (FAME).
  19. Chong ETJ, Neoh JWF, Lau TY, Lim YA, Chai HC, Chua KH, et al.
    Malar J, 2020 Oct 22;19(1):377.
    PMID: 33092594 DOI: 10.1186/s12936-020-03451-x
    BACKGROUND: Understanding the genetic diversity of candidate genes for malaria vaccines such as circumsporozoite protein (csp) may enhance the development of vaccines for treating Plasmodium knowlesi. Hence, the aim of this study is to investigate the genetic diversity of non-repeat regions of csp in P. knowlesi from Malaysian Borneo and Peninsular Malaysia.

    METHODS: A total of 46 csp genes were subjected to polymerase chain reaction amplification. The genes were obtained from P. knowlesi isolates collected from different divisions of Sabah, Malaysian Borneo, and Peninsular Malaysia. The targeted gene fragments were cloned into a commercial vector and sequenced, and a phylogenetic tree was constructed while incorporating 168 csp sequences retrieved from the GenBank database. The genetic diversity and natural evolution of the csp sequences were analysed using MEGA6 and DnaSP ver. 5.10.01. A genealogical network of the csp haplotypes was generated using NETWORK ver. 4.6.1.3.

    RESULTS: The phylogenetic analysis revealed indistinguishable clusters of P. knowlesi isolates across different geographic regions, including Malaysian Borneo and Peninsular Malaysia. Nucleotide analysis showed that the csp non-repeat regions of zoonotic P. knowlesi isolates obtained in this study underwent purifying selection with population expansion, which was supported by extensive haplotype sharing observed between humans and macaques. Novel variations were observed in the C-terminal non-repeat region of csp.

    CONCLUSIONS: The csp non-repeat regions are relatively conserved and there is no distinct cluster of P. knowlesi isolates from Malaysian Borneo and Peninsular Malaysia. Distinctive variation data obtained in the C-terminal non-repeat region of csp could be beneficial for the design and development of vaccines to treat P. knowlesi.

  20. Goh LPW, Chong ETJ, Lee PC
    PMID: 33050119 DOI: 10.3390/ijerph17207354
    Alpha(α)-thalassemia is a blood disorder caused by many types of inheritable α-globin gene mutations which causes no-to-severe clinical symptoms, such as Hb Bart's hydrops fetalis that leads to early foetal death. Therefore, the aim of this meta-analysis was to provide an update from year 2010 to 2020 on the prevalence of α-thalassemia in Southeast Asia. A systematic literature search was performed using PubMed and SCOPUS databases for related studies published from 2010 to 2020, based on specified inclusion and exclusion criteria. Heterogeneity of included studies was examined with the I2 index and Q-test. Funnel plots and Egger's tests were performed in order to determine publication bias in this meta-analysis. Twenty-nine studies with 83,674 subjects were included and pooled prevalence rates in this meta-analysis were calculated using random effect models based on high observed heterogeneity (I2 > 99.5, p-value < 0.1). Overall, the prevalence of α-thalassemia is 22.6%. The highest α-thalassemia prevalence was observed in Vietnam (51.5%) followed by Cambodia (39.5%), Laos (26.8%), Thailand (20.1%), and Malaysia (17.3%). No publication bias was detected. Conclusions: This meta-analysis suggested that a high prevalence of α-thalassemia occurred in selected Southeast Asia countries. This meta-analysis data are useful for designing thalassemia screening programs and improve the disease management.
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