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Fulltext Optical DNA Biosensor Based on Square-Planar Ethyl Piperidine Substituted Nickel(II) Salphen Complex for Dengue Virus Detection

Ariffin EY, Tan LL, Abd Karim NH, Yook Heng L

Sensors (Basel), 2018 Apr 12;18(4).
PMID: 29649118 DOI: 10.3390/s18041173

A sensitive and selective optical DNA biosensor was developed for dengue virus detection based on novel square-planar piperidine side chain-functionalized N,N'-bis-4-(hydroxysalicylidene)-phenylenediamine-nickel(II), which was able to intercalate via nucleobase stacking within DNA and be functionalized as an optical DNA hybridization marker. 3-Aminopropyltriethoxysilane (APTS)-modified porous silica nanospheres (PSiNs), was synthesized with a facile mini-emulsion method to act as a high capacity DNA carrier matrix. The Schiff base salphen complexes-labelled probe to target nucleic acid on the PSiNs renders a colour change of the DNA biosensor to a yellow background colour, which could be quantified via a reflectance transduction method. The reflectometric DNA biosensor demonstrated a wide linear response range to target DNA over the concentration range of 1.0 × 10-16-1.0 × 10-10 M (R² = 0.9879) with an ultralow limit of detection (LOD) at 0.2 aM. The optical DNA biosensor response was stable and maintainable at 92.8% of its initial response for up to seven days of storage duration with a response time of 90 min. The reflectance DNA biosensor obtained promising recovery values of close to 100% for the detection of spiked synthetic dengue virus serotypes 2 (DENV-2) DNA concentration in non-invasive human samples, indicating the high accuracy of the proposed DNA analytical method for early diagnosis of all potential infectious diseases or pathological genotypes.
Fulltext Nutrients and Oxidative Stress: Friend or Foe?

Tan BL, Norhaizan ME, Liew WP

Oxid Med Cell Longev, 2018;2018:9719584.
PMID: 29643982 DOI: 10.1155/2018/9719584

There are different types of nutritionally mediated oxidative stress sources that trigger inflammation. Much information indicates that high intakes of macronutrients can promote oxidative stress and subsequently contribute to inflammation via nuclear factor-kappa B- (NF-κB-) mediated cell signaling pathways. Dietary carbohydrates, animal-based proteins, and fats are important to highlight here because they may contribute to the long-term consequences of nutritionally mediated inflammation. Oxidative stress is a central player of metabolic ailments associated with high-carbohydrate and animal-based protein diets and excessive fat consumption. Obesity has become an epidemic and represents the major risk factor for several chronic diseases, including diabetes, cardiovascular disease (CVD), and cancer. However, the molecular mechanisms of nutritionally mediated oxidative stress are complex and poorly understood. Therefore, this review aimed to explore how dietary choices exacerbate or dampen the oxidative stress and inflammation. We also discussed the implications of oxidative stress in the adipocyte and glucose metabolism and obesity-associated noncommunicable diseases (NCDs). Taken together, a better understanding of the role of oxidative stress in obesity and the development of obesity-related NCDs would provide a useful approach. This is because oxidative stress can be mediated by both extrinsic and intrinsic factors, hence providing a plausible means for the prevention of metabolic disorders.
A Dual Bioconjugated Virus-Like Nanoparticle as a Drug Delivery System and Comparison with a pH-Responsive Delivery System

Biabanikhankahdani R, Ho KL, Alitheen NB, Tan WS

Nanomaterials (Basel), 2018 Apr 13;8(4).
PMID: 29652827 DOI: 10.3390/nano8040236

Modifications of virus-like nanoparticles (VLNPs) using chemical conjugation techniques have brought the field of virology closer to nanotechnology. The huge surface area to volume ratio of VLNPs permits multiple copies of a targeting ligand and drugs to be attached per nanoparticle. By exploring the chemistry of truncated hepatitis B core antigen (tHBcAg) VLNPs, doxorubicin (DOX) was coupled covalently to the external surface of these nanoparticles via carboxylate groups. About 1600 DOX molecules were conjugated on each tHBcAg VLNP. Then, folic acid (FA) was conjugated to lysine residues of tHBcAg VLNPs to target the nanoparticles to cancer cells over-expressing folic acid receptor (FR). The result demonstrated that the dual bioconjugated tHBcAg VLNPs increased the accumulation and uptake of DOX in the human cervical and colorectal cancer cell lines compared with free DOX, resulting in enhanced cytotoxicity of DOX towards these cells. The fabrication of these dual bioconjugated nanoparticles is simple, and drugs can be easily conjugated with a high coupling efficacy to the VLNPs without any limitation with respect to the cargo's size or charge, as compared with the pH-responsive system based on tHBcAg VLNPs. These dual bioconjugated nanoparticles also have the potential to be modified for other combinatorial drug deliveries.
Fulltext Oxidative stress-induced chromosome breaks within the ABL gene: a model for chromosome rearrangement in nasopharyngeal carcinoma

Tan SN, Sim SP, Khoo AS

Hum Genomics, 2018 06 18;12(1):29.
PMID: 29914565 DOI: 10.1186/s40246-018-0160-8

BACKGROUND: The mechanism underlying chromosome rearrangement in nasopharyngeal carcinoma (NPC) remains elusive. It is known that most of the aetiological factors of NPC trigger oxidative stress. Oxidative stress is a potent apoptotic inducer. During apoptosis, chromatin cleavage and DNA fragmentation occur. However, cells may undergo DNA repair and survive apoptosis. Non-homologous end joining (NHEJ) pathway has been known as the primary DNA repair system in human cells. The NHEJ process may repair DNA ends without any homology, although region of microhomology (a few nucleotides) is usually utilised by this DNA repair system. Cells that evade apoptosis via erroneous DNA repair may carry chromosomal aberration. Apoptotic nuclease was found to be associated with nuclear matrix during apoptosis. Matrix association region/scaffold attachment region (MAR/SAR) is the binding site of the chromosomal DNA loop structure to the nuclear matrix. When apoptotic nuclease is associated with nuclear matrix during apoptosis, it potentially cleaves at MAR/SAR. Cells that survive apoptosis via compromised DNA repair may carry chromosome rearrangement contributing to NPC tumourigenesis. The Abelson murine leukaemia (ABL) gene at 9q34 was targeted in this study as 9q34 is a common region of loss in NPC. This study aimed to identify the chromosome breakages and/or rearrangements in the ABL gene in cells undergoing oxidative stress-induced apoptosis.
RESULTS: In the present study, in silico prediction of MAR/SAR was performed in the ABL gene. More than 80% of the predicted MAR/SAR sites are closely associated with previously reported patient breakpoint cluster regions (BCR). By using inverse polymerase chain reaction (IPCR), we demonstrated that hydrogen peroxide (H2O2)-induced apoptosis in normal nasopharyngeal epithelial and NPC cells led to chromosomal breakages within the ABL BCR that contains a MAR/SAR. Intriguingly, we detected two translocations in H2O2-treated cells. Region of microhomology was found at the translocation junctions. This observation is consistent with the operation of microhomology-mediated NHEJ.
CONCLUSIONS: Our findings suggested that oxidative stress-induced apoptosis may participate in chromosome rearrangements of NPC. A revised model for oxidative stress-induced apoptosis mediating chromosome rearrangement in NPC is proposed.
Automated diagnosis of arrhythmia using combination of CNN and LSTM techniques with variable length heart beats

Oh SL, Ng EYK, Tan RS, Acharya UR

Comput Biol Med, 2018 11 01;102:278-287.
PMID: 29903630 DOI: 10.1016/j.compbiomed.2018.06.002

Arrhythmia is a cardiac conduction disorder characterized by irregular heartbeats. Abnormalities in the conduction system can manifest in the electrocardiographic (ECG) signal. However, it can be challenging and time-consuming to visually assess the ECG signals due to the very low amplitudes. Implementing an automated system in the clinical setting can potentially help expedite diagnosis of arrhythmia, and improve the accuracies. In this paper, we propose an automated system using a combination of convolutional neural network (CNN) and long short-term memory (LSTM) for diagnosis of normal sinus rhythm, left bundle branch block (LBBB), right bundle branch block (RBBB), atrial premature beats (APB) and premature ventricular contraction (PVC) on ECG signals. The novelty of this work is that we used ECG segments of variable length from the MIT-BIT arrhythmia physio bank database. The proposed system demonstrated high classification performance in the handling of variable-length data, achieving an accuracy of 98.10%, sensitivity of 97.50% and specificity of 98.70% using ten-fold cross validation strategy. Our proposed model can aid clinicians to detect common arrhythmias accurately on routine screening ECG.
Fulltext Integrative taxonomy of a new and highly-diverse genus of onchidiid slugs from the Coral Triangle (Gastropoda, Pulmonata, Onchidiidae)

Goulding TC, Khalil M, Tan SH, Dayrat B

Zookeys, 2018.
PMID: 29896045 DOI: 10.3897/zookeys.763.21252

A new genus of onchidiid slugs, Wallaconchis Goulding & Dayrat, gen. n., is described, including ten species. Five species were previously described but known only from the type material: Wallaconchis ater (Lesson, 1830), W. graniferum (Semper, 1880), W. nangkauriense (Plate, 1893), W. buetschlii (Stantschinsky, 1907), and W. gracile (Stantschinsky, 1907), all of which were originally classified in Onchidium Buchannan, 1800. Many new records are provided for these five species, which greatly expand their known geographic distributions. Five species are new: Wallaconchis achleitneri Goulding, sp. n., W. comendadori Goulding & Dayrat, sp. n., W. melanesiensis Goulding & Dayrat, sp. n., W. sinanui Goulding & Dayrat, sp. n., and W. uncinus Goulding & Dayrat, sp. n. Nine of the ten Wallaconchis species are found in the Coral Triangle (eastern Indonesia and the Philippines). Sympatry is high, with up to six species found on the island of Bohol (Philippines) and eight species overlapping in northern Sulawesi (Indonesia). Wallaconchis is distinguished from other onchidiids by its bright dorsal colors (red, yellow, orange) but those are extremely variable and not useful for specific identification. Internally, the reproductive system can be used to identify all Wallaconchis species. The copulatory organs of Wallaconchis species are especially diverse compared to other onchidiid genera, and the possible role of reproductive incompatibility in species diversification is discussed. All specimens examined were freshly collected for the purpose of a worldwide revision of the Onchidiidae Rafinesque, 1815. The species are well delineated using DNA sequences and comparative anatomy. Mitochondrial DNA analysis yields thirteen molecular units separated by a large barcode gap, while nuclear DNA yields nine units. By integrating nuclear DNA and mitochondrial DNA with morphology, ten species are recognized. The natural history of each species (e.g., the microhabitat where they are found) is also documented. Nomenclature is addressed thoroughly (the types of all onchidiid species were examined, lectotypes were designated when needed, nomina dubia are discussed). Morphological characters, transitions to new microhabitats, and diversification processes are discussed in the context of a robust molecular phylogeny.
Cytochrome P450 genotype-guided drug therapies: An update on current states

Dong AN, Tan BH, Pan Y, Ong CE

Clin Exp Pharmacol Physiol, 2018 10;45(10):991-1001.
PMID: 29858511 DOI: 10.1111/1440-1681.12978

Over the past 2 decades, knowledge of the role and clinical value of pharmacogenetic markers has expanded so that individualized pre-emptive therapy based on genetic background of patients could be within reach for clinical implementation. This is evidenced from the frequent updating of drug labels that incorporates pharmacogenetic information (where compelling data become available) by the regulatory agencies (such as the US FDA), and the periodical publication of guidelines of specific therapeutic recommendations based on the results of pharmacogenetic tests by the pharmacogenetics working groups or consortiums of professional bodies. Clinical relevance of the cytochrome P450 (CYP) polymorphism related to dose, effectiveness and/or toxicity of key drugs are presented in this review, including that of warfarin, clopidogrel, tricyclic antidepressants, and proton pump inhibitors. Prospect for routine clinical application of CYP genotyping before prescribing drugs is still currently unclear due to challenges and barriers associated with availability of well-defined and validated pharmacogenetic studies, the interpretation, result reporting and potential error of genotype testing, involvement of non-genetic factors, and other patient's demographic and disease conditions. Further studies to provide additional supporting clinical data and acceleration of pharmacogenetic testing standards and techniques should help improve the evidence base needed for clinical utility and hence move the implementation of genotype-guided therapy in clinical practice a step closer to reality.
Features of post-radioiodine whole body scan in non-invasive Follicular Thyroid Neoplasm with papillary-like nuclear features (NIFTP)

Wong TH, Tan TH, Chin SC, Lee BN

Med J Malaysia, 2018 06;73(3):181-182.
PMID: 29962506

Recently, encapsulated follicular variant of papillary thyroid carcinoma has been reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) to emphasize the benign nature of this entity. In our institution, we have assessed 455 patients treated with radioiodine ablation for differentiated thyroid carcinoma and 20 of them were retrospectively found to fulfill the new NIFTP criteria. There was no evidence of metastasis on post radioiodine whole body scans for NIFTP cases and these patients were in remission subsequently. The benign features of these patients' whole body scans and good clinical outcome following treatment further support NIFTP as a low risk thyroid neoplasm.
The utilization of phototherapy in the department of dermatology, Hospital Kuala Lumpur: A 5-year audit

Vaani VV, Tang MM, Tan LL, Asmah J

Med J Malaysia, 2018 06;73(3):125-130.
PMID: 29962494 MyJurnal

INTRODUCTION: Ultraviolet phototherapies are important treatment modalities for a wide range of dermatological conditions. We aim to describe the utilization of phototherapy in the Department of Dermatology Hospital Kuala Lumpur.
METHODS: This is a 5-year retrospective audit on patients who underwent phototherapy between 2011 and 2015.
RESULTS: There were 892 patients, M:F=1.08:1, aged from 4- 88 years, with a median age of 38.8 years who underwent phototherapy. Majority (58.9%) had skin phototype IV, followed by type III (37.7%) and type II (0.7%). There were 697(78.1%) who underwent NBUVB, 136 (15.2%) had topical PUVA, 22(2.5%) had oral PUVA, 12(1.4%) had UVA1 and 23(2.6%) had NBUVB with topical or oral PUVA/UVA1 at different time periods. The indications were psoriasis (46.6%), vitiligo (26.7%), atopic eczema (9.8%), pityriasis lichenoides chronica (5.3%), mycosis fungoides (3.9%), lichen planus (2.5%), nodular prurigo (2.2%), scleroderma (1.2%), alopecia areata (0.7%) and others. The median number of session received were 27 (range 1-252) for NBUVB, 30 (range 1-330) for topical PUVA, 30 (range 3-190) for oral PUVA and 24.5 (range 2-161) for UVA1. The acute adverse effects experienced by patients were erythema (18%), pruritus (16.3%), warmth (3.3%), blister formation (3.1%), cutaneous pain (2.4%), and xerosis (0.8%), skin swelling (0.7%) and phototoxicity (0.2%).
CONCLUSION: Narrow-band UVB was the most frequently prescribed phototherapy modality in our center. The most common indication for phototherapy in our setting was psoriasis. Acute adverse events occurred in a third of patients, although these side effects were mild.
Fulltext Cultural adaptation and linguistic validation of the Beliefs about Medicines Questionnaire in Malaysia

Tan CS, Hassali MA, Neoh CF, Saleem F, Horne R

Value Health Reg Issues, 2018 May;15:161-168.
PMID: 29730249 DOI: 10.1016/j.vhri.2017.12.010

BACKGROUND: Low rate of adherence was found strongly associated with patients' beliefs across the studies about chronic diseases with hypertension. A crucial move is needed to bridge the gap between appropriate assessment tools and local hypertensive patients' medication adherence.

OBJECTIVE: To produce a translated version in Malay language of Beliefs about Medicines Questionnaire (BMQ) that was "conceptually equivalent" to the original English version for use in local clinical practice and research.

METHODS: The forward translation process was conducted by two independent professional translators and back translation was done by two other independent translators. A reliability analysis was conducted on 238 conveniently selected hypertensive patients. Intraclass correlation coefficient (ICC) was used to assess test-retest reliability for the randomly selected 40 patients in a period of 2 weeks. Discriminant validity was tested through Necessity-Concerns differential, BMQ subscales, and other parameters.

RESULTS: The overall Cronbach alpha for the internal consistency was good (0.860). The subscales of the BMQ demonstrated adequate internal consistency, with Cronbach alpha value of 0.759 for Specific-Necessity, 0.762 for Specific Concern, 0.624 for General-Overuse, and 0.756 for General-Harm. The ICC was excellent (0.922). Discriminant validity revealed that BMQ Specific-Necessity score was significantly inversely correlated with the systolic blood pressure level. Systolic and diastolic blood pressure levels (P = 0.038; P = 0.05) were reported to be significantly correlated with the Necessity-Concerns differential, with Necessity score equal or exceeding Concerns score.

CONCLUSIONS: The Malay-translated version of BMQ is a reliable and valid tool to assess patient belief about medication, especially medication adherence among the hypertensive patients in Malaysia.
Process intensification of core streptavidin production through high-cell-density cultivation of recombinant E. coli and a temperature-based refolding method

Chua LH, Tan SC, Liew MWO

J Biotechnol, 2018 Jun 20;276-277:34-41.
PMID: 29679607 DOI: 10.1016/j.jbiotec.2018.04.012

An intensified process was developed that enables high level production of recombinant core streptavidin (cSAV), a non-glycosylated tetrameric protein utilised in a wide range of applications. A pH-stat fed-batch feeding strategy was employed to achieve high-cell-density and improve volumetric yield of cSAV which was expressed as inclusion bodies (IBs). The effect of induction at different cell densities (OD 20, 60 and 100) on volumetric and specific yield were then studied. Highest volumetric yield of cSAV (1550 mg L-1) was obtained from induction at OD 100 without significant reductions in specific yield. To recover active cSAV from IBs, the possibility of refolding using a temperature-based refolding method was investigated. Refolded cSAV obtained from temperature-based refolding were then compared against cSAV refolded with conventional dialysis and dilution methods using quantitative and qualitative metrics. The temperature-based refolding method was found to improve the yield of cSAV by 6-18% in comparison to conventional methods without compromising quality. Intensification was achieved by reductions in process volumes and a more concentrated product stream. Using the newly developed process, the volumetric yield of cSAV IBs was improved by thirty-six fold in comparison to low-cell-density shake flask cultivation, and 33% of cSAV can be recovered from IBs at 90% purity.
Identification of Potential Anticancer Protein Targets in Cytotoxicity Mediated by Tropical Medicinal Fern Extracts

Tan ST, Ong HC, Chai TT, Wong FC

Pharmacogn Mag, 2018 04 10;14(54):227-230.
PMID: 29720836 DOI: 10.4103/pm.pm_282_17

Background: Medicinal fern species represent a potentially important source for both food and medicinal applications. Previously, two underutilized tropical fern species (Blechnum orientale and Phymatopteris triloba) were reported with cytotoxic activities against selected cancer cell lines. However, the exact mechanism remains elusive.
Objective: In this paper, we reported the identification of six differentially expressed proteins isolated from cancer cells, following exposure to the cytotoxic fern extracts.
Materials and Methods: The identities of these cancer proteins were determined by matrix-assisted laser desorption ionization time-of-flight protein sequencing.
Results: The cancer proteins were identified as follows: elongation factor 1-γ, glyceraldehydes-3-phosphate dehydrogenase, heat shock protein 90-β, heterogeneous nuclear ribonucleoprotein-A2/B1, truncated nucleolar phosphoprotein B23, and tubulin-β chain. To the best of our knowledge, this paper represents the first time these cancer proteins are being reported, following exposure to the aforementioned cytotoxic fern extracts.
Conclusion: It is hoped that further efforts in this direction could lead to the identification and development of target-specific chemotherapeutic agents.
SUMMARY: Cytotoxic fern extracts were tested in anti-cancer proteomic works.Six differentially-expressed cancer proteins were identified.Potential anti-cancer protein targets were reported. Abbreviations used: EF: Elongation factor; HRP: Horseradish peroxidase; HSP: Heat shock protein; MALDI: Matrix-assisted laser desorption/ionization.
Reduced bone mineral density in human immunodeficiency virus-infected individuals: a meta-analysis of its prevalence and risk factors: supplementary presentation

Goh SSL, Lai PSM, Tan ATB, Ponnampalavanar S

Osteoporos Int, 2018 07;29(7):1683.
PMID: 29737369 DOI: 10.1007/s00198-018-4379-y

A meta-analysis was conducted to evaluate the prevalence of osteopenia/osteoporosis in human immunodeficiency virus (HIV)-infected individuals. The prevalence of osteopenia/osteoporosis in HIV-infected and antiretroviral therapy (ART)-treated individuals was significantly higher than respective controls. Evidence regarding bone loss within first year of HIV infection or ART initiation was preliminary.
What's on YouTube? A Case Study on Food and Beverage Advertising in Videos Targeted at Children on Social Media

Tan L, Ng SH, Omar A, Karupaiah T

Child Obes, 2018 07;14(5):280-290.
PMID: 29985649 DOI: 10.1089/chi.2018.0037

BACKGROUND: Unhealthy food marketing to children is a key risk factor for childhood obesity. Online video platforms have surpassed television as the primary choice for screen viewing among children but the extent of food marketing through such media is relatively unknown. We aimed to examine food and beverage advertisements (ads) encountered in YouTube videos targeting children in Malaysia.
METHODS: The social media analytics site SocialBlade.com was used to identify the most popular YouTube videos (n = 250) targeting children. Ads encountered while viewing these videos were recorded and analyzed for type of product promoted and ad format (video vs. overlay). Food and beverage ads were further coded based on food category and persuasive marketing techniques used.
RESULTS: In total 187 ads were encountered in sampled videos. Food and beverage ads were the most common at 38% (n=71), among which 56.3% (n = 40) promoted noncore foods. Ads for noncore foods were more commonly delivered as video rather than overlay ads. Among ads promoting noncore foods, the most commonly employed persuasive marketing techniques found were taste appeal (42.3%), uniqueness/novelty (32.4%), the use of animation (22.5%), fun appeal (22.5%), use of promotional characters (15.5%), price (12.7%), and health and nutrition benefits (8.5%).
CONCLUSIONS: Similar to television, unhealthy food ads predominate in content aimed toward children on YouTube. Policies regulating food marketing to children need to be extended to cover online content in line with a rapidly-evolving digital media environment. Service providers of social media can play a part in limiting unhealthy food advertising to children.
Fulltext Neonatal malaria presenting as neonatal sepsis: a case report

Lim KY, Ang EL, Tan KK, Mustakim S

Malaysian Journal of Paediatrics and Child Health, 2016;22(1):48-57.
MyJurnal

Neonatal malaria may be overlooked likely due to its non-specific features and low prevalence in Malaysia. In this case report, we detail a case of neonatal malaria in an 18-day old baby girl of Myanmar origin who presented with 6 days of intermittent fever but was otherwise well. Initially, she was treated as neonatal sepsis. She then developed thrombocytopaenia and severe anaemia with persistent spikes of temperature. This prompted a series of investigations and multiple changes of antibiotics. The diagnosis of neonatal malaria surfaced when her peripheral blood film incidentally revealed the presence of Plasmodium vivax parasites. Peripheral blood smears are simple and inexpensive. Therefore practising especially in endemic areas for malaria, we need to consider this diagnosis when dealing with neonatal sepsis that does not respond to standard treatment.
Fulltext The effects of temperature on extracted teeth of different age groups: A pilot study

George R, Tan WJ, Shih Yi AL, Donald PM

J Forensic Dent Sci, 2018 4 17;9(3):165-174.
PMID: 29657495 DOI: 10.4103/jfo.jfds_25_16

Context: Type of dentition and age related changes may affect the behavior of dental hard tissues under thermal stress.
Aim: This study was conducted to analyze the effects of varying temperatures on extracted teeth of different age groups in a simulated laboratory set up.
Settings and Design: Experimental pilot study.
Methods and Material: Extracted teeth from three age groups (deciduous, young permanent and adult permanent) were collected and were exposed to three different temperatures (400°C, 700°C and 1000°C) in a laboratory set up. Post-test changes were analyzed visually and radiographically.
Results: (1) The colour changes of the teeth may serve as an indicator for the temperature to which they were exposed. (2) Deciduous teeth tolerated thermal stress with lesser morphological changes compared to young and adult permanent teeth. (3) Coronal dentin of elderly permanent teeth appeared to be more resistant to thermal stress compared to that of young permanent teeth. (4) The root portion of the teeth showed better tolerance to temperature while crown was fragmented easily under thermal stress.
Conclusion: The age factor and type of the dentition may influence the heat induced changes in teeth. These variables should be taken into consideration while applying comparative dental identification methods where dental hard tissues are exposed to extreme temperatures.
Fulltext Obesity and unhealthy lifestyle associated with poor executive function among Malaysian adolescents

Tee JYH, Gan WY, Tan KA, Chin YS

PLoS One, 2018;13(4):e0195934.
PMID: 29664932 DOI: 10.1371/journal.pone.0195934

The understanding on the roles of obesity and lifestyle behaviors in predicting executive function of adolescents has been limited. Low executive function proficiency may have adverse effects on adolescents' school academic performance. This cross-sectional study aimed to examine the relationship between BMI-for-age and multiple lifestyle behaviors (operationalized as meal consumption, physical activity, and sleep quality) with executive function (operationalized as inhibition, working memory, and cognitive flexibility) on a sample of Malaysian adolescents aged between 12 and 16 years (N = 513). Participants were recruited from two randomly selected schools in the state of Selangor in Malaysia. Using a self-administered questionnaire, parent participants provided information concerning their sociodemographic data, whereas adolescent participants provided information regarding their meal consumptions, physical activity, and sleep quality. The modified Harvard step test was used to assess adolescents' aerobic fitness, while Stroop color-word, digit span, and trail-making tests were used to assess adolescents' inhibition, working memory, and cognitive flexibility, respectively. Three separate hierarchical regression analyses were conducted for each outcome namely, inhibition, working memory, and cognitive flexibility. After adjusted for sociodemographic factors and BMI-for-age, differential predictors of inhibition and working memory were found. Habitual sleep efficiency significantly and positively predicted inhibition. Regular dinner intakes, physical activity levels, and sleep quality significantly and positively predicted working memory. Household income emerged as a consistent predictor for all executive function domains. In conclusion, an increased trend of obesity and unhealthy lifestyles among adolescents were found to be associated with poorer executive function. Regular dinner intakes, higher physical activity levels and better sleep quality predicted better executive function despite the inverse relationship between obesity and executive function. Future studies may explore how lifestyle modifications can optimize the development of executive function in adolescents as well as relieve the burden of obesity.
A 10-years retrospective study on Severe Cutaneous Adverse Reactions (SCARs) in a tertiary hospital in Penang, Malaysia

Loo CH, Tan WC, Khor YH, Chan LC

Med J Malaysia, 2018 04;73(2):73-77.
PMID: 29703869 MyJurnal

INTRODUCTION: Severe cutaneous adverse drug reactions (SCARs) are not uncommon and potentially lifethreatening. Our objective is to study the patient characteristics, the pattern of implicated drugs and treatment outcome among patients with SCARs.
METHODS: A 10-year retrospective analysis of SCARs cases in Penang General Hospital was carried out from January 2006 to December 2015. Data collection is based on the Malaysian Adverse Drug Reactions Advisory Committee registry and dermatology clinic records.
RESULTS: A total of 189 cases of SCARs were encountered (F:M ratio; 1.2:1.0; mean age of 45 year). The commonest manifestation was Stevens-Johnson Syndrome [SJS] (55.0%), followed by toxic epidermal necrolysis [TEN] (23.8%), drug rash with eosinophilia and systemic symptoms [DRESS] (12.7%), acute generalised exanthematous pustulosis [AGEP] (4.8%), SJS/TEN overlap syndrome (2.6%) and generalised bullous fixed drug eruptions [GBFDE] (1.1%). Mean time to onset for TEN/SJS/Overlap syndrome was 10.5±13 days; AGEP, three days; GBFDE, 2.5±0.7 days, and DRESS, 29.4±5.7 days. The most common drugs implicated were antibiotics (33.3%), followed by allopurinol (18.9%) and anticonvulsant (18.4%). Out of 154 cases of SJS/TEN/overlap syndrome, allopurinol was the commonest causative agents (20.1%). In DRESS, allopurinol accounts for 45.8% of the cases. The mortality rate in SJS, TEN and DRESS were 1.9%, 13.3% and 12.5% respectively. No mortality was observed in AGEP and GBFDE.
CONCLUSION: The commonest manifestations of SCARs in our setting were SJS, TEN and DRESS. Allopurinol was the most common culprit. Thus, judicious allopurinol use is advocated and pre-emptive genetic screening for HLAB *5801 should be considered.
Fulltext Enhanced physicochemical stability and efficacy of angiotensin I-converting enzyme (ACE) - inhibitory biopeptides by chitosan nanoparticles optimized using Box-Behnken design

Auwal SM, Zarei M, Tan CP, Basri M, Saari N

Sci Rep, 2018 Jul 10;8(1):10411.
PMID: 29991723 DOI: 10.1038/s41598-018-28659-5

Bromelain-generated biopeptides from stone fish protein exhibit strong inhibitory effect against ACE and can potentially serve as designer food (DF) with blood pressure lowering effect. Contextually, the DF refer to the biopeptides specifically produced to act as ACE-inhibitors other than their primary role in nutrition and can be used in the management of hypertension. However, the biopeptides are unstable under gastrointestinal tract (GIT) digestion and need to be stabilized for effective oral administration. In the present study, the stone fish biopeptides (SBs) were stabilized by their encapsulation in sodium tripolyphosphate (TPP) cross-linked chitosan nanoparticles produced by ionotropic gelation method. The nanoparticles formulation was then optimized via Box-Behnken experimental design to achieve smaller particle size (162.70 nm) and high encapsulation efficiency (75.36%) under the optimum condition of SBs:Chitosan mass ratio (0.35), homogenization speed (8000 rpm) and homogenization time (30 min). The SBs-loaded nanoparticles were characterized for morphology by transmission electron microscopy (TEM), physicochemical stability and efficacy. The nanoparticles were then lyophilized and analyzed using Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The results obtained indicated a sustained in vitro release and enhanced physicochemical stability of the SBs-loaded nanoparticles with smaller particle size and high encapsulation efficiency following long period of storage. Moreover, the efficacy study revealed improved inhibitory effect of the encapsulated SBs against ACE following simulated GIT digestion.
Cell Proliferation and DNA Repair Ability of Ganoderma neo-japonicum (Agaricomycetes): An Indigenous Medicinal Mushroom from Malaysia

Tan WC, Kuppusamy UR, Phan CW, Sabaratnam V

Int J Med Mushrooms, 2018;20(2):155-163.
PMID: 29773007 DOI: 10.1615/IntJMedMushrooms.2018025445

Ganoderma neo-japonicum is an annual polypore that grows on decaying bamboo in the forests of Malaysia. The indigenous Temuan tribe uses this species as a medicinal mushroom to cure fever and epilepsy and to improve body strength. The potential use of G. neo-japonicum in genoprotection and DNA repair was established using a single-cell gel electrophoresis (comet) assay. The effects of the ethanol and hot aqueous extracts from wild and cultivated basidiocarps, solid substrate-fermented (SSF) wheat grains, and mycelia via submerged culture on H2O2-damaged murine RAW264.7 macrophages were investigated. An ethanol extract from wild basidiocarps showed the most significant protective effect on murine RAW264.7 macrophages, followed by ethanol and hot water extracts of cultivated basidiocarps, and this effect was dose dependent. However, only the ethanol extracts from SSF and submerged culture showed significant protective effects compared with the control. As for DNA repair ability, only the ethanol extract from wild and cultivated basidiocarps showed significant results when compared with the negative control. The findings suggest the potential therapeutic use of G. neo-japonicum in genome protection and as a DNA repair stimulator.

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