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  1. Fulltext Obesity among schoolchildren in Kuala Selangor: a cross-sectional study
    Sumarni Mohd G, Muhammad Amir K, Ibrahim Md S, Mohd Rodi I, Izzuna Mudla MG, Nurziyana I
    Trop Biomed, 2006 Dec;23(2):148-54.
    PMID: 17322816
    Childhood obesity is an established problem in many countries and emerging in others. Epidemiological data on obesity in children is essential in order to plan public health policy and services. A study was conducted to determine the prevalence of obesity in schoolchildren in the fifth grade of elementary school (10-12 years old) in the district of Kuala Selangor. Ten schools of which five are in urban and five in rural areas were selected consisting of 699 eleven year old schoolchildren from the three major ethnic groups. Using international cut-off points for obesity, we report an overall prevalence of obesity of 7.2%. Prevalence of obesity in urban children is 7.2% whereas in rural children it is 7.0 %. Analysed by gender, there were 8.9% obese boys and 5.3% obese girls. Among the 3 major ethnic groups, the Malays had the highest prevalence of obesity at 9.3% followed by the Chinese with 6.6% while among Indians 3.0%. The data obtained from this study suggests that obesity in Kuala Selangor children is a cause for concern in urban and rural areas.
  2. To lump, to split or to maintain? Molecular taxonomy of the spotted barb Barbodes binotatus (Cyprinidae) and closely related species in Peninsular Malaysia
    Ahmad Sobri NZ, Lavoué S, Aziz F, Mohd Nor SA, Mohammed Akib NA, Khaironizam MZ
    J Fish Biol, 2021 Aug;99(2):656-668.
    PMID: 33855740 DOI: 10.1111/jfb.14754
    The taxonomic status of the Southeast Asian spotted barb, Barbodes binotatus (Teleostei: Cyprinidae), has puzzled researchers because of large but inconsistent geographic variation of its body melanin marking pattern. In this study, the authors appraise the differentiation of B. binotatus and two closely related species, Barbodes rhombeus and saddle barb, Barbodes banksi, in Peninsular Malaysia using mitochondrial and nuclear markers. The results of this study reveal that the Peninsular Malaysia populations of each of the three species form largely reciprocal monophyletic lineages that differ from each other by a minimum of 2.3% p-genetic distance using COI gene. Nonetheless, specimens of B. binotatus in Peninsular Malaysia are only distantly related to specimens of B. binotatus in Java (type locality). The monophyly of B. banksi is not refuted although specimens of Peninsular Malaysia are genetically distinct from those of Sarawak (type locality). The authors discuss alternative hypotheses whether each of these three valid species is a single species or each of the main five genetic lineages revealed in this study represents a distinct species. Preliminary investigations reveal a mito-nuclear discordance at one locality in Peninsular Malaysia where B. binotatus and B. banksi co-occur. Further studies should inform on the extent of reproductive porousness between these two lineages and others.
  3. Fulltext Genetic Variability, Heritability, and Clustering Pattern Exploration of Bambara Groundnut (Vigna subterranea L. Verdc) Accessions for the Perfection of Yield and Yield-Related Traits
    Khan MMH, Rafii MY, Ramlee SI, Jusoh M, Mamun A
    Biomed Res Int, 2020;2020:2195797.
    PMID: 33415143 DOI: 10.1155/2020/2195797
    Bambara groundnut (Vigna subterranea L. Verdc.) is considered an emerging crop for the future and known as a crop for the new millennium. The core intention of this research work was to estimate the variation of landraces of Bambara groundnut considering their 14 qualitative and 27 numerical traits, to discover the best genotype fitted in Malaysia. The findings of the ANOVA observed a highly significant variation (p ≤ 0.01) for all the traits evaluated. There was a substantial variation (7.27 to 41.21%) coefficient value, and 14 out of the 27 numerical traits noted coefficient of variation (CV) ≥ 20%. Yield (kg/ha) disclosed positively strong to perfect high significant correlation (r = 0.75 to 1.00; p ≤ 0.001) with traits like fresh pod weight, dry pod weight, and dry seed weight. The topmost PCV and GCV values were estimated for biomass dry (41.09%) and fresh (40.53%) weight with high heritability (Hb) and genetic advance (GA) Hb = 95.19%, GA = 80.57% and Hb = 98.52%, GA = 82.86%, respectively. The topmost heritability was recorded for fresh pod weight (99.89%) followed by yield (99.75%) with genetic advance 67.95% and 62.03%, respectively. The traits with Hb ≥ 60% and GA ≥ 20% suggested the least influenced by the environment as well as governed by the additive genes and direct selection for improvement of such traits can be beneficial. To estimate the genetic variability among accessions, the valuation of variance components, coefficients of variation, heritability, and genetic advance were calculated. To authenticate the genetic inequality, an unweighted pair group produced with arithmetic mean (UPGMA) and principal component analysis was executed based on their measurable traits that could be a steadfast method for judging the degree of diversity. Based on the UPGMA cluster analysis, constructed five distinct clusters and 44 accessions from clusters II and IV consider an elite type of genotypes that produce more than one ton yield per hectare land with desirable traits. This study exposed an extensive disparity among the landraces and the evidence on genetic relatives will be imperative in using the existing germplasm for Bambara groundnut varietal improvement. Moreover, this finding will be beneficial for breeders to choose the desirable numerical traits of V. subterranea in their future breeding program.
  4. Difference in glaucoma progression between the first and second eye after consecutive bilateral glaucoma surgery in patients with bilateral uveitic glaucoma
    Din NM, Talat L, Isa H, Tomkins-Netzer O, Barton K, Lightman S
    Graefes Arch Clin Exp Ophthalmol, 2016 Dec;254(12):2439-2448.
    PMID: 27495303
    PURPOSE: To determine whether the second eyes (SE) of patients with bilateral uveitic glaucoma undergoing filtration surgery have more glaucomatous progression in terms of visual acuity, visual field (VF) and optic nerve changes compared to the first eyes (FE).

    METHODS: This retrospective study analysed data of 60 eyes from 30 patients with bilateral uveitic glaucoma who had undergone glaucoma surgery in both eyes on separate occasions. Humphrey VF progression was assessed using the Progressor software.

    RESULTS: The pre-operative IOP between the FE (43.1 ± 7.7 mmHg) and SE (40 ± 8.7 mmHg) was not statistically significant (p = 0.15). IOP reduction was greater in the FE (64 %) than SE (59.7 %) post-operatively, but the mean IOP at the final visit in the FE (12.3 ± 3.9 mmHg) and SE (14.5 ± 7 mmHg) was not statistically different (p = 0.2). There was no significant change in mean logMAR readings pre and post-operatively (0.45 ± 0.6 vs 0.37 ± 0.6, p = 0.4) or between the FE and SE. The number of SE with CDR > 0.7 increased by 23 % compared to the FE. From 23 available VFs, five SE (21.7 %) progressed at a median of five locations (range 1-11 points) with a mean local slope reduction of 1.74 ± 0.45 dB/year (range -2.39 to -1.26), whereas only one FE progressed. However, there was no significant difference between mean global rate of progression between the FE (-0.9 ± 1.6 dB/year) and SE (-0.76 ± 2.1 dB/year, p = 0.17) in the Humphrey VF.

    CONCLUSION: In eyes with bilateral uveitic glaucoma requiring glaucoma surgery, the SEs had more progressed points on VF and glaucomatous disc progression compared to FEs at the final visit.

  5. Effect of prolonged supine position on the intraocular pressure in patients with obstructive sleep apnea syndrome
    Fang SY, Wan Abdul Halim WH, Mat Baki M, Din NM
    Graefes Arch Clin Exp Ophthalmol, 2018 Apr;256(4):783-790.
    PMID: 29492688 DOI: 10.1007/s00417-018-3919-7
    PURPOSE: Obstructive sleep apnea syndrome (OSAS) patients are at risk of glaucoma but the risk increases if they have higher intraocular pressure (IOP) while sleeping. We aim to evaluate the postural effect of upright and prolong supine positions on IOP in these patients.

    METHODS: This is a cross-sectional study involving 27 patients with symptoms of OSAS seen at a tertiary institutional center and 25 normal controls performed between June 2015 and June 2016. All patients and controls underwent a polysomnography (PSG) test and were diagnosed with OSAS based on the apnea-hypopnea index (AHI). Patients are those with OSAS symptoms and had AHI > 5, whereas controls are staffs from the ophthalmology clinic without clinical criteria for OSAS and had PSG result of AHI

  6. Selective targeting of cancer signaling pathways with nanomedicines: challenges and progress
    Barkat HA, Das SS, Barkat MA, Beg S, Hadi HA
    Future Oncol, 2020 Dec;16(35):2959-2979.
    PMID: 32805124 DOI: 10.2217/fon-2020-0198
    Cancer is one of the leading causes of death worldwide. Regardless of advances in understanding the molecular mechanics of cancer, its treatment is still lacking and the death rates for many forms of the disease remain the same as six decades ago. Although a variety of therapeutic agents and strategies have been reported, these therapies often failed to provide efficient therapy to patients as a consequence of the inability to deliver right and adequate chemotherapeutic agents to the right place. However, the situation has started to revolutionize substantially with the advent of novel 'targeted' nanocarrier-based cancer therapies. Such therapies hold great potential in cancer management as they are biocompatible, tailored to specific needs, tolerated and deliver enough drugs at the targeted site. Their use also enhances the delivery of chemotherapeutics by improving biodistribution, lowering toxicity, inhibiting degradation and increasing cellular uptake. However, in some instances, nonselective targeting is not enough and the inclusion of a ligand moiety is required to achieve tumor targeting and enhanced drug accumulation at the tumor site. This contemporary review outlines the targeting potential of nanocarriers, highlighting the essentiality of nanoparticles, tumor-associated molecular signaling pathways, and various biological and pathophysiological barriers.
  7. Fulltext Implementation of Kinetic and Kinematic Variables in Ergonomic Risk Assessment Using Motion Capture Simulation: A Review
    Yunus MNH, Jaafar MH, Mohamed ASA, Azraai NZ, Hossain MS
    Int J Environ Res Public Health, 2021 08 06;18(16).
    PMID: 34444087 DOI: 10.3390/ijerph18168342
    Work-related musculoskeletal disorders (WMSDs) are among the most common disorders in any work sector and industry. Ergonomic risk assessment can reduce the risk of WMSDs. Motion capture that can provide accurate and real-time quantitative data has been widely used as a tool for ergonomic risk assessment. However, most ergonomic risk assessments that use motion capture still depend on the traditional ergonomic risk assessment method, focusing on qualitative data. Therefore, this article aims to provide a view on the ergonomic risk assessment and apply current motion capture technology to understand classical mechanics of physics that include velocity, acceleration, force, and momentum in ergonomic risk assessment. This review suggests that using motion capture technologies with kinetic and kinematic variables, such as velocity, acceleration, and force, can help avoid inconsistency and develop more reliable results in ergonomic risk assessment. Most studies related to the physical measurement conducted with motion capture prefer to use non-optical motion capture because it is a low-cost system and simple experimental setup. However, the present review reveals that optical motion capture can provide more accurate data.
  8. Fulltext An Artificial Intelligence-Enabled Pipeline for Medical Domain: Malaysian Breast Cancer Survivorship Cohort as a Case Study
    Ganggayah MD, Dhillon SK, Islam T, Kalhor F, Chiang TC, Kalafi EY, et al.
    Diagnostics (Basel), 2021 Aug 18;11(8).
    PMID: 34441426 DOI: 10.3390/diagnostics11081492
    Automated artificial intelligence (AI) systems enable the integration of different types of data from various sources for clinical decision-making. The aim of this study is to propose a pipeline to develop a fully automated clinician-friendly AI-enabled database platform for breast cancer survival prediction. A case study of breast cancer survival cohort from the University Malaya Medical Centre was used to develop and evaluate the pipeline. A relational database and a fully automated system were developed by integrating the database with analytical modules (machine learning, automated scoring for quality of life, and interactive visualization). The developed pipeline, iSurvive has helped in enhancing data management as well as to visualize important prognostic variables and survival rates. The embedded automated scoring module demonstrated quality of life of patients whereas the interactive visualizations could be used by clinicians to facilitate communication with patients. The pipeline proposed in this study is a one-stop center to manage data, to automate analytics using machine learning, to automate scoring and to produce explainable interactive visuals to enhance clinician-patient communication along the survivorship period to modify behaviours that relate to prognosis. The pipeline proposed can be modelled on any disease not limited to breast cancer.
  9. Fulltext A Recommendation for a Pre-Standardized Marine Microalgal Dry Weight Determination Protocol for Laboratory Scale Culture Using Ammonium Formate as a Washing Agent
    Khaw YS, Tan HT, Sopawong A, Shaharuddin NA, Omar AR, Yusoff FM
    Biology (Basel), 2021 Aug 19;10(8).
    PMID: 34440031 DOI: 10.3390/biology10080799
    Microalgal biomass is one of the crucial criteria in microalgal studies. Many reported methods, even the well-established protocol on microalgal dry weight (DW) determination, vary greatly, and reliable comparative assessment amongst published results could be problematic. This study aimed to determine the best condition of critical parameters in marine microalgal DW determination for laboratory-scale culture using four different marine microalgal species. These parameters included the washing process, grades of glass microfiber filter (GMF), GMF pretreatment conditions, washing agent (ammonium formate) concentrations, culture: washing agent ratios (v:v) and washing cycles. GMF grade GF/A with precombustion at 450 °C provided the most satisfactory DW and the highest ash-free dry weight (AFDW)/DW ratio. Furthermore, 0.05 M ammonium formate with 1:2 culture: washing agent ratio and a minimum of two washing cycles appeared to be the best settings of microalgal DW determination. The present treatment increased the AFDW/DW ratio of the four respective microalgae by a minimum of 19%. The findings of this study could serve as a pivotal reference in developing a standardized protocol of marine microalgal DW determination to obtain veracious and reliable marine microalgal DW.
  10. Fulltext Calculation of Cement Composition Using a New Model Compared to the Bogue Model
    Shim SH, Lee TH, Yang SJ, Noor NBM, Kim JH
    Materials (Basel), 2021 Aug 19;14(16).
    PMID: 34443190 DOI: 10.3390/ma14164663
    The major cement composition ratios of alite, belite, aluminate, and ferrite have been calculated with the Bogue models until now. However, a recent comprehensive analysis based on various experimental data has revealed that the chemical composition of alite, belite, aluminate, and ferrite implemented by the Bogue models are slightly different than the experimental data, where small amounts of Al2O3 and Fe2O3 existing in alite and belite can change the prediction of cement composition. Since the amounts of cement compound are very important factors in determining the properties of concrete, improvement in the calculation would give more precise prediction for application usages such as climate change adaptable cement and high durable concrete manufacturing. For this purpose, 20 new models are proposed by modifying chemical compositions of the cement compounds and verified with the 50 experimental data sets. From the verification, the most accurate models are identified. The calculation using new models exhibit an accuracy improvement of approximately 5% compared to the Bogue models. Their applicable range is also presented. The study results are discussed in detail in the paper.
  11. Multi-step molecular docking and dynamics simulation-based screening of large antiviral specific chemical libraries for identification of Nipah virus glycoprotein inhibitors
    Kalbhor MS, Bhowmick S, Alanazi AM, Patil PC, Islam MA
    Biophys Chem, 2021 03;270:106537.
    PMID: 33450550 DOI: 10.1016/j.bpc.2020.106537
    Nipah virus (NiV) infections are highly contagious and can cause severe febrile encephalitis. An outbreak of NiV infection has reported high mortality rates in Southeast Asian countries including Bangladesh, East Timor, Malaysia, Papua New Guinea, Vietnam, Cambodia, Indonesia, Madagascar, Philippines, Thailand and India. Considering the high risk for an epidemic outbreak, the World Health Organization (WHO) declared NiV as an emerging priority pathogen. However, there are no effective therapeutics or any FDA approved drugs available for the treatment of this infection. Among the known nine proteins of NiV, glycoprotein plays an important role in initiating the entry of viruses and attaching to the host cell receptors. Herein, three antiviral databases consisting of 79,892 chemical entities have been computationally screened against NiV glycoprotein (NiV-G). Particularly, multi-step molecular docking followed by extensive molecular binding interactions analyses, binding free energy estimation, in silico pharmacokinetics, synthetic accessibility and toxicity profile evaluations have been carried out for initial identification of potential NiV-G inhibitors. Further, molecular dynamics (MD) simulation has been performed to understand the dynamic properties of NiV-G protein-bound with proposed five inhibitors (G1-G5) and their interactions behavior, and any conformational changes in NiV-G protein during simulations. Moreover, Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) based binding free energies (∆G) has been calculated from all MD simulation trajectories to understand the energy contribution of each proposed compound in maintaining and stabilizing the complex binding interactions with NiV-G protein. Proposed compounds showed high negative ∆G values ranging from -166.246 to -226.652 kJ/mol indicating a strong affinity towards the NiV-G protein.
  12. Fulltext Diagnostic Accuracy of Rapid Antigen Test Kits for Detecting SARS-CoV-2: A Systematic Review and Meta-Analysis of 17,171 Suspected COVID-19 Patients
    Khandker SS, Nik Hashim NHH, Deris ZZ, Shueb RH, Islam MA
    J Clin Med, 2021 Aug 08;10(16).
    PMID: 34441789 DOI: 10.3390/jcm10163493
    Early diagnosis is still as crucial as the initial stage of the COVID-19 pandemic. As RT-PCR sometimes is not feasible in developing nations or rural areas, health professionals may use a rapid antigen test (RAT) to lessen the load of diagnosis. However, the efficacy of RAT is yet to be investigated thoroughly. Hence, we tried to evaluate the overall performance of RAT in SARS-CoV-2 diagnosis. Based on our PROSPERO registered protocol (CRD42021231432), we searched online databases (i.e., PubMed, Google Scholar, Scopus, and Web of Science) and analysed overall pooled specificity and sensitivity of RAT along with study quality, publication bias, heterogeneity and more. The overall pooled specificity and sensitivity of RAT were detected as 99.4% (95% CI: 99.1-99.8; I2 = 90%) and 68.4% (95% CI: 60.8-75.9; I2 = 98%), respectively. In subgroup analyses, nasopharyngeal specimens and symptomatic patient's samples were more sensitive in RAT, while cycle threshold (Ct) values were found to have an inverse relationship with sensitivity. In the European and American populations, RAT showed better performance. Although the sensitivity of RAT is yet to be improved, it could still be an alternative in places with poor laboratory set up. Nevertheless, the negative samples of RAT can be re-tested using RT-PCR to reduce false negative results.
  13. Fulltext Hydrothermal Modification of Wood: A Review
    Ali MR, Abdullah UH, Ashaari Z, Hamid NH, Hua LS
    Polymers (Basel), 2021 Aug 06;13(16).
    PMID: 34451152 DOI: 10.3390/polym13162612
    Wood is a versatile material that is used for various purposes due to its good properties, such as its aesthetic properties, acoustic properties, mechanical properties, thermal properties, etc. Its poor dimensional stability and low natural durability are the main obstacles that limit its use in mechanical applications. Therefore, modification is needed to improve these properties. The hydrothermal modification of wood exposes wood samples to elevated temperatures and pressure levels by using steam, water, or a buffer solution as the treating medium, or by using superheated steam. Abundant studies regarding hydrothermally treated wood were carried out, but the negative effect on the wood's strength is one of the limitations. This is a method that boosts the dimensional stability and improves the decay resistance of wood with minimal decrements of the strength properties. As an ecofriendly and cost-effective method, the hydrothermal modification of wood is also a promising alternative to conventional chemical techniques for treating wood. Researchers are attracted to the hydrothermal modification process because of its unique qualities in treating wood. There are many scientific articles on the hydrothermal modification of wood, and many aspects of hydrothermal modification are summarized in review papers in this field. This paper reviews the hydrothermally modified mechanical properties of wood and their potential applications. Furthermore, this article reviews the effects of hydrothermal modification on the various properties of wood, such as the dimensional stability, chemical properties, and durability against termites and fungi. The merits and demerits of hydrothermal wood modification, the effectiveness of using different media in hydrothermal modification, and its comparison with other treating techniques are discussed.
  14. Fulltext Efficacy and Safety of Intranasal Ketamine for Acute Pain Management in the Emergency Setting: A Systematic Review and Meta-Analysis
    Seak YS, Nor J, Tuan Kamauzaman TH, Arithra A, Islam MA
    J Clin Med, 2021 Sep 02;10(17).
    PMID: 34501425 DOI: 10.3390/jcm10173978
    Due to overcrowding, personnel shortages, or problematic intravenous (IV) cannulation, acute pain management is often sub-optimal in emergency departments (EDs). The objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of intranasal (IN) ketamine for adult acute pain in the emergency setting. We searched and identified studies up to 21 May 2021 via PubMed, Scopus, Web of Science, Cochrane Database, and Google Scholar. The random-effects model with 95% confidence intervals (CIs) was used to estimate mean differences (MDs) and odds ratios (ORs). The I2 statistic and Cochran's Q test were used to determine heterogeneity. The protocol was registered in PROSPERO (CRD42020213391). Seven randomised controlled trials were included with a total of 1760 patients. There was no significant difference in pain scores comparing IN ketamine with IV analgesics or placebo at 5 (MD 0.94, p = 0.26), 15 (MD 0.15, p = 0.74), 25 (MD 0.24, p = 0.62), 30 (MD -0.05, p = 0.87), and 60 (MD -0.42, p = 0.53) minutes. There was also no significant difference in the need for rescue analgesics between IN ketamine and IV analgesics (OR 1.66, 95% CI: 0.57-4.86, p = 0.35, I2 = 70%). Only mild adverse effects were observed in patients who received IN ketamine. Our results suggest that IN ketamine is non-inferior to IV analgesics and may have a role in acute pain management among adults in the ED.
  15. Dietary polyphenols suppress chronic inflammation by modulation of multiple inflammation-associated cell signaling pathways
    Jantan I, Haque MA, Arshad L, Harikrishnan H, Septama AW, Mohamed-Hussein ZA
    J Nutr Biochem, 2021 07;93:108634.
    PMID: 33794330 DOI: 10.1016/j.jnutbio.2021.108634
    The high failure rate of the reductionist approach to discover effective and safe drugs to treat chronic inflammatory diseases has led scientists to seek alternative ways. Recently, targeting cell signaling pathways has been utilized as an innovative approach to discover drug leads from natural products. Cell signaling mechanisms have been identified playing key role in diverse diseases by inducing proliferation, cell survival and apoptosis. Phytochemicals are known to be able to modulate the cellular and molecular networks which are associated to chronic diseases including cancer-associated inflammation. In this review, the roles of dietary polyphenols (apigenin, kaempferol, quercetin, curcumin, genistein, isoliquiritigenin, resveratrol and gallic acid) in modulating multiple inflammation-associated cell signaling networks are deliberated. Scientific databases on suppressive effects of the polyphenols on chronic inflammation via modulation of the pathways especially in the recent five years are gathered and critically analyzed. The polyphenols are able to modulate several inflammation-associated cell signaling pathways, namely nuclear factor-kappa β, mitogen activated protein kinases, Wnt/β-catenin and phosphatidylinositol 3-kinase and protein kinase B via selective actions on various components of the networks. The suppressive effects of the polyphenols on the multiple cell signaling pathways reveal their potential use in prevention and treatment of chronic inflammatory disorders. Understanding the mechanistic effects involved in modulation of the signaling pathways by the polyphenols is necessary for lead identification and development of future functional foods for prevention and treatment of chronic inflammatory diseases.
  16. Factors influencing COVID-19 vaccine hesitancy and acceptance among the Pakistani population
    Chaudhary FA, Ahmad B, Khalid MD, Fazal A, Javaid MM, Butt DQ
    Hum Vaccin Immunother, 2021 Oct 03;17(10):3365-3370.
    PMID: 34236952 DOI: 10.1080/21645515.2021.1944743
    This study examined the factors associated with acceptance of the COVID-19 vaccine compared to hesitance in the Pakistani population and specifically focusing on the perceived beliefs, knowledge, concerns, risk, and safety perception relating to the COVID-19 vaccine. A total of 423 subjects were recruited from the Pakistan Institute of Medical Sciences, Islamabad, Pakistan. A 27-item valid and reliable questionnaire was used to assess socio-demographic characteristics, acceptance, and hesitance toward COVID-19 vaccine, perceived beliefs, knowledge, perceived concerns, risk, and safety of COVID-19 vaccines and its source of information. Chi-square tests and logistic regression were used for analysis. About 53% of the participants were planning to get vaccinated and a significantly greater proportion of better educated, higher income, and healthier participants in the vaccine acceptance group (p
  17. Flow-through chloroquine sensor and its applications in pharmaceutical analysis
    Saad B, Zin ZM, Jab MS, Rahman IA, Saleh MI, Mahsufi S
    Anal Sci, 2005 May;21(5):521-4.
    PMID: 15913140
    Poly (vinyl chloride) membrane electrodes that responded selectively towards the antimalarial drug chloroquine are described. The electrodes were based on the use of the lipophilic potassium tetrakis(4-chlorophenyl)borate as ion-exchanger and bis(2-ethylhexyl)adipate (BEHA), or trioctylphosphate (TOP) or dioctylphenylphosphonate (DOPP) as plasticizing solvent mediator. All electrodes produced good quality characteristics such as Nernstian- and rapid responses, and are minimally interfered with by the alkali and alkaline earth metal ions tested. The membranes were next applied to a flow-through device, enabling it to function as flow-injection analysis (FIA) detector. The performance of the sensor after undergoing the FIA optimization was further evaluated for its selectivity characteristics and lifetime. Results for the determination of chloroquine in synthetic samples that contained common tablet excipients such as glucose, starch, and cellulose, and other foreign species such as cations, citric acid or lactic acid were generally satisfactory. The sensor was also successfully used for the determination of the active ingredients in mock tablets, synthetic fluids and biological fluids. The sensor was applied for the determination of active ingredients and the dissolution profile of commercial tablets was also established.
  18. Structural and functional characterisation of a cold-active yet heat-tolerant dehydroquinase from Glaciozyma antarctica PI12
    Jaafar NR, Mahadi NM, Mackeen MM, Illias RM, Murad AMA, Abu Bakar FD
    J Biotechnol, 2021 Mar 10;329:118-127.
    PMID: 33539893 DOI: 10.1016/j.jbiotec.2021.01.019
    Dehydroquinase or 3-dehydroquinate dehydratase (DHQD) reversibly cleaves 3-dehydroquinate to form 3-dehydroshikimate. Here, we describe the functional and structural features of a cold active type II 3-dehydroquinate dehydratase from the psychrophilic yeast, Glaciozyma antarctica PI12 (GaDHQD). Functional studies showed that the enzyme was active at low temperatures (10-30 °C), but displayed maximal activity at 40 °C. Yet the enzyme was stable over a wide range of temperatures (10-70 °C) and between pH 6.0-10.0 with an optimum pH of 8.0. Interestingly, the enzyme was highly thermo-tolerant, denaturing only at approximately 84 °C. Three-dimensional structure analyses showed that the G. antarctica dehydroquinase (GaDHQD) possesses psychrophilic features in comparison with its mesophilic and thermophilic counterparts such as higher numbers of non-polar residues on the surface, lower numbers of arginine and higher numbers of glycine-residues with lower numbers of hydrophobic interactions. On the other hand, GaDHQD shares some traits (i.e. total number of hydrogen bonds, number of proline residues and overall folding) with its mesophilic and thermophilic counterparts. Combined, these features contribute synergistically towards the enzyme's ability to function at both low and high temperatures.
  19. Fulltext Molecular Dynamics Simulations in Designing DARPins as Phosphorylation-Specific Protein Binders of ERK2
    Gautam V, Nimmanpipug P, Zain SM, Rahman NA, Lee VS
    Molecules, 2021 Jul 27;26(15).
    PMID: 34361694 DOI: 10.3390/molecules26154540
    Extracellular signal-regulated kinases 1 and 2 (ERK1/2) play key roles in promoting cell survival and proliferation through the phosphorylation of various substrates. Remarkable antitumour activity is found in many inhibitors that act upstream of the ERK pathway. However, drug-resistant tumour cells invariably emerge after their use due to the reactivation of ERK1/2 signalling. ERK1/2 inhibitors have shown clinical efficacy as a therapeutic strategy for the treatment of tumours with mitogen-activated protein kinase (MAPK) upstream target mutations. These inhibitors may be used as a possible strategy to overcome acquired resistance to MAPK inhibitors. Here, we report a class of repeat proteins-designed ankyrin repeat protein (DARPin) macromolecules targeting ERK2 as inhibitors. The structural basis of ERK2-DARPin interactions based on molecular dynamics (MD) simulations was studied. The information was then used to predict stabilizing mutations employing a web-based algorithm, MAESTRO. To evaluate whether these design strategies were successfully deployed, we performed all-atom, explicit-solvent molecular dynamics (MD) simulations. Two mutations, Ala → Asp and Ser → Leu, were found to perform better than the original sequence (DARPin E40) based on the associated energy and key residues involved in protein-protein interaction. MD simulations and analysis of the data obtained on these mutations supported our predictions.
  20. Fulltext Microsatellite Characterization of Malaysian Mahseer (Tor spp.) for Improvement of Broodstock Management and Utilization
    Chew PC, Christianus A, Zudaidy JM, Ina-Salwany MY, Chong CM, Tan SG
    Animals (Basel), 2021 Sep 08;11(9).
    PMID: 34573599 DOI: 10.3390/ani11092633
    In this study, a mixture of Tor tambra and T. tambroides with unknown genetic background were collected from 11 localities in Malaysia for broodstock development and sperm cryo-banking. This study aims to assess the microsatellite (simple sequence repeat, SSR) variation, genetic diversity, genetic differentiation, level of gene flow, population structure, genetic relatedness and their demographic aspects among these Tor populations, in addition to establishing their SSR profile by employing 22 SSR markers via fragment analysis. Total genomic DNA was extracted from 181 samples (91 cryopreserved milt samples and 90 scale samples of live broodfish). Results showed the Tor spp. collection retained their genetic variation but exhibited excessive homozygosity among individuals within population. Moderate genetic differentiation was shown among the populations, with highly significant (p < 0.001) fixation indices (FST, FIS and FIT). A low gene flow over all loci (Nm 1.548) indicates little genetic variation transfer between populations. The genetic structures of all the populations were successfully resolved into four main clusters by an unweighted pair group method with arithmetic mean (UPGMA) dendrogram generated based on Nei's genetic distances. The population structures based on principal coordinates analysis (PCoA) and the Bayesian model also suggested four distinct clusters following geographical regions and eight closely related populations. This study provided a useful baseline reference for better genetic management and utilization of the Tor spp. stocks in their breeding and conservation programmes.
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