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Fulltext Morphological Diversity of Gracilaria blodgettii Harvey 1853 (Gracilariaceae, Rhodophyta) from Sarawak, Malaysian Borneo

Hassan R, Othman MNA, Harith MN, Md Sah ASR

Scientifica (Cairo), 2019;2019:3430968.
PMID: 31355044 DOI: 10.1155/2019/3430968

Gracilaria red algae are notable for their economic importance as agrophytes, sold as salad vegetable, and used as the base for selected food and nonalcoholic beverages. A wild population of Gracilaria exists in coastal areas of Sarawak, Malaysian Borneo, but there is only limited knowledge on species diversity and its abundance leaving the untapped economic potential of this resource. This study was carried out to determine diversity of wild Gracilaria populations in Lawas, Santubong, and Asajaya, Sarawak, using the combination of morphological character examination and 5' region of the mitochondrial cytochrome c oxidase 1 (CO1-5P) gene analysis. Identification of the species using morphological characters revealed three species, namely, Gracilaria changii, G. blodgettii, and G. arcuata, had been collected from the sampling sites. However, based on 672 bp CO1-5P gene sequence analysis, all the three species were identified as G. blodgettii; besides, low genetic divergence values (0.17%-0.34%) were scored between samples in this study with the same species in GenBank. In the phylogenetic trees, all samples in this study group together with other G. blodgettii have high bootstrap values; thus, this species is monophyletic. This study implies that species identification of Gracilaria and other seagrass taxa which have a phenotypic plasticity problem should include the CO1-5P gene analysis as it is a reliable gene marker for species diversity assessment.
Environmental Factors Associated with the Presence of Vibrionaceae in Tropical Cage-Cultured Marine Fishes

Mohamad N, Mustafa M, Amal MNA, Saad MZ, Md Yasin IS, Al-Saari N

J Aquat Anim Health, 2019 06;31(2):154-167.
PMID: 30653742 DOI: 10.1002/aah.10062

This study investigated the environmental factors associated with the presence of Vibrionaceae in economically important cage-cultured tropical marine fishes: the Asian Seabass Lates calcarifer, snapper Lutjanus sp., and hybrid grouper Epinephelus sp. Fish sampling was conducted at monthly intervals between December 2016 and August 2017. The body weight and length of individual fish were measured, and the skin, eye, liver, and kidney were sampled for bacterial isolation and identification. Water physicochemical parameters during the sampling activities were determined, and the enumeration of total Vibrionaceae count was also conducted from water and sediment samples. Nine species of Vibrio were identified, including V. alginolyticus, V. diabolicus, V. harveyi, V. campbellii, V. parahaemolyticus, V. rotiferianus, V. furnissii, V. fluvialis, and V. vulnificus. Photobacterium damselae subsp. damselae was also identified. A total of 73% of the isolated Vibrio belonged to the Harveyi clade, followed by the Vulnificus clade (5.5%) and Cholera clade (0.6%). Highest occurrence of Vibrio spp. and P. damselae subsp. damselae was found in hybrid grouper (72%), followed by Asian Seabass (48%) and snapper (36%). The associations of Vibrio spp. and P. damselae subsp. damselae with the host fish were not species specific. However, fish mortality and fish size showed strong associations with the presence of some Vibrio spp. On average, 60% of the infected cultured fish exhibited at least one clinical sign. Nevertheless, inconsistent associations were observed between the pathogens and water quality. The yearlong occurrence and abundance of Vibrionaceae in the environmental components indicate that they might serve as reservoirs of these pathogens.
Topologically significant directed random walk with applied walker network in cancer environment

Seah CS, Kasim S, Saedudin RR, Md Fudzee MF, Mohamad MS, Hassan R, et al.

Pak J Pharm Sci, 2019 May;32(3 Special):1395-1408.
PMID: 31551221

Numerous cancer studies have combined different datasets for the prognosis of patients. This study incorporated four networks for significant directed random walk (sDRW) to predict cancerous genes and risk pathways. The study investigated the feasibility of cancer prediction via different networks. In this study, multiple micro array data were analysed and used in the experiment. Six gene expression datasets were applied in four networks to study the effectiveness of the networks in sDRW in terms of cancer prediction. The experimental results showed that one of the proposed networks is outstanding compared to other networks. The network is then proposed to be implemented in sDRW as a walker network. This study provides a foundation for further studies and research on other networks. We hope these finding will improve the prognostic methods of cancer patients.
Fulltext Combining In Silico and In Vitro Studies to Evaluate the Acetylcholinesterase Inhibitory Profile of Different Accessions and the Biomarker Triterpenes of Centella asiatica

Jusril NA, Muhamad Juhari ANN, Abu Bakar SI, Md Saad WM, Adenan MI

Molecules, 2020 Jul 24;25(15).
PMID: 32721993 DOI: 10.3390/molecules25153353

Alzheimer's disease (AD) is a neurodegenerative disease and the most cause of dementia in elderly adults. Acetylcholinesterase (AChE) is an important beneficial target for AD to control cholinergic signaling deficit. Centella asiatica (CA) has proven to be rich with active ingredients for memory enhancement. In the present study, the chemical profiling of three accession extracts of CA namely SECA-K017, SECA-K018, and, SECA-K019 were performed using high-performance liquid chromatography (HPLC). Four biomarker triterpene compounds were detected in all CA accessions. Quantitative analysis reveals that madecassoside was the highest triterpene in all the CA accessions. The biomarker compounds and the ethanolic extracts of three accessions were investigated for their acetylcholinesterase (AChE) inhibitory activity using Ellman's spectrophotometer method. The inhibitory activity of the triterpenes and accession extracts was compared with the standard AChE inhibitor eserine. The results from the in vitro study showed that the triterpene compounds exhibited an AChE inhibitory activity with the half-maximal inhibitory concentration (IC50) values between 15.05 ± 0.05 and 59.13 ± 0.18 µg/mL. Asiatic acid was found to possess strong AChE inhibitory activity followed by madecassic acid. Among the CA accession extracts, SECA-K017 and SECA-K018 demonstrated a moderate AChE inhibitory activity with an IC50 value of 481.5 ± 0.13 and 763.5 ± 0.16 µg/mL, respectively from the in silico docking studies, it is observed that asiatic acid and madecassic acid showed very good interactions with the active sites and fulfilled docking parameters against AChE. The present study suggested that asiatic acid and madecassic acid in the CA accessions could be responsible for the AChE inhibitory action and could be used as markers to guide further studies on CA as potential natural products for the treatment of AD.
Pyogenic Granuloma Formation Following Ahmed Valve Glaucoma Implant

Chendran P, Seng Fai T, Wan Abdul Halim WH, Md Din N

J Glaucoma, 2019 10;28(10):e162-e164.
PMID: 31368915 DOI: 10.1097/IJG.0000000000001334

Ocular pyogenic granuloma is a benign tumor seen after ocular insult secondary to ocular surgeries, trauma or infection. Although benign, intervention is sometimes necessary. Previous authors have reported pyogenic granuloma formation following oculoplastic surgeries. We report a pyogenic granuloma after an Ahmed glaucoma valve implantation. A 65-year-old gentleman presented with right eye redness associated with pain and swelling ~2 months after Ahmed glaucoma valve implantation. Examination found a sessile growth on the tube extruding puss with signs of endophthalmitis. The glaucoma drainage device was explanted and culture results grew Staphylococcus aureus. This article discusses the formation of pyogenic granuloma on a glaucoma drainage device and its management.
Raised Intraocular Pressure in Nonjuvenile Idiopathic Arthritis-Uveitis Children: Risk Factors and Effect on Retinal Nerve Fiber Layer

Md Din N, Tomkins-Netzer O, Talat L, Taylor SR, Isa H, Bar A, et al.

J Glaucoma, 2016 07;25(7):598-604.
PMID: 26900824 DOI: 10.1097/IJG.0000000000000379

PURPOSE: To determine risk factors for intraocular pressure (IOP) elevation and glaucoma in children with nonjuvenile idiopathic arthritis-related uveitis and any IOP-related changes in the retinal nerve fiber layer (RNFL) thickness.

PATIENTS AND METHODS: Clinical data were collected from children attending a tertiary referral uveitis clinic between May 2010 and October 2012. We assigned 206 eyes of 103 children into 32 normal eyes, 108 normotensive uveitics (NU), 41 hypertensive uveitics (HU: raised IOP without glaucomatous disc), and 25 glaucomatous uveitics (GU: raised IOP with glaucomatous disc). Risk factors for raised IOP, glaucoma and steroid response (SR) were evaluated and RNFL thickness across groups was compared with determine changes related to raised IOP.

RESULTS: IOP elevation occurred in 40 patients (38.8%) or 66/174 eyes with uveitis (37.9%); and SR occurred in 35.1% of all corticosteroid-treated eyes. Chronic uveitis was a significant risk factor for raised IOP [odds ratio (OR)=9.28, P=0.001], glaucoma, and SR (OR=8.4, P<0.001). Higher peak IOP was also a risk factor for glaucoma (OR=1.4, P=0.003). About 70% of SR eyes were high responders (IOP increase >15 mm Hg from baseline), associated with younger age and corticosteroid injections. Although no significant RNFL thinning was detected between HU and NU eyes, significant thinning was detected in the inferior quadrant of GU (121.3±28.9 μm) compared with NU eyes (142.1±32.0 μm, P=0.043).

CONCLUSIONS: Children with chronic uveitis are at higher risk of raised IOP and glaucoma. Thinning of the inferior RNFL quadrant may suggest glaucomatous changes in uveitic children with raised IOP.

Study site: Moorfields Eye Hospital, London
Fulltext Fast-track- recovery surgery with a whey-protein-infused carbohydrate-loading drink pre-operatively and early oral feeding post-operatively among surgical gynaecological cancer patients: study protocol of an open-labelled, randomised controlled trial

Ho CY, Ibrahim Z, Abu Zaid Z, Mat Daud Z', Md Yusop NB

Trials, 2020 Jun 16;21(1):533.
PMID: 32546217 DOI: 10.1186/s13063-020-04462-4

INTRODUCTION: There has been growing evidence on the favourable outcomes of fast-track-recovery (FTR) surgery; to expedite recovery, minimise complications, and reduce the length of hospital stay for surgical patients. However, there is lack of evidence on the effectiveness of FTR in surgical gynaecological cancer (GC) patients. Most of the previous studies did not focus on feeding composition in the FTR surgery protocol. This study aims to determine the effectiveness of FTR feeding with a whey-protein-infused carbohydrate-loading drink pre-operatively and early oral feeding post-operatively on post-operative outcomes among surgical GC patients.
METHODS/DESIGN: This open-labelled, randomised controlled trial (RCT) will randomly allocate patients into intervention and control groups. Ambulated Malaysian aged over 18 years and scheduled for elective surgery for (suspected) GC, will be included in this study. The intervention group will be given whey-protein-infused carbohydrate-loading drinks on the evening before their operation and 3 h before their operation as well as started on early oral feeding 4 h post-operatively. The control group will be fasted overnight pre-operation and only allowed plain water, and return to a normal diet is allowed when bowel sounds return post-operatively. The primary outcomes of study are length of post-operative hospital stay, length of clear-fluid tolerance, solid-food tolerance and bowel function. Additional outcome measures are changes in nutritional status, biochemical profile and functional status. Data will be analysed on an intention-to-treat basis.
TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03667755. Retrospectively registered on 12 September 2018; Protocol version: version 3 dated 27 September 2017.
Review of chitosan composite as a heavy metal adsorbent: Material preparation and properties

Begum S, Yuhana NY, Md Saleh N, Kamarudin NHN, Sulong AB

Carbohydr Polym, 2021 May 01;259:117613.
PMID: 33673980 DOI: 10.1016/j.carbpol.2021.117613

A large amount of wastewater is typically discharged into water bodies and has extremely harmful effects to aquatic environments. The removal of heavy metals from water bodies is necessary for the safe consumption of water and human activities. The demand for seafood has considerably increased, and millions of tons of crustacean waste are discarded every year. These waste products are rich in a natural biopolymer known as chitin. The deacetylated form of chitin, chitosan, has attracted attention as an adsorbent. It is a biocompatible and biodegradable polymer that can be modified and converted to various derivatives. This review paper focuses on relevant literature on strategies for chemically modifying the biopolymer and its use in the removal of heavy metals from water and wastewater. The different aspects of chitosan-based derivatives and their preparation and application are elucidated. A list of chitosan-based composites, along with their adsorptivity and experimental conditions, are compiled.
Rhamnolipid produced by Pseudomonas aeruginosa USM-AR2 facilitates crude oil distillation

Asshifa Md Noh N, Al-Ashraf Abdullah A, Nasir Mohamad Ibrahim M, Ramli Mohd Yahya A

J Gen Appl Microbiol, 2012;58(2):153-61.
PMID: 22688247

A biosurfactant-producing and hydrocarbon-utilizing bacterium, Pseudomonas aeruginosa USM-AR2, was used to assist conventional distillation. Batch cultivation in a bioreactor gave a biomass of 9.4 g L(-1) and rhamnolipid concentration of 2.4 g L(-1) achieved after 72 h. Biosurfactant activity (rhamnolipid) was detected by the orcinol assay, emulsification index and drop collapse test. Pretreatment of crude oil TK-1 and AG-2 with a culture of P. aeruginosa USM-AR2 that contains rhamnolipid was proven to facilitate the distillation process by reducing the duration without reducing the quality of petroleum distillate. It showed a potential in reducing the duration of the distillation process, with at least 2- to 3-fold decreases in distillation time. This is supported by GC-MS analysis of the distillate where there was no difference between compounds detected in distillate obtained from treated or untreated crude oil. Calorimetric tests showed the calorie value of the distillate remained the same with or without treatment. These two factors confirmed that the quality of the distillate was not compromised and the incubation process by the microbial culture did not over-degrade the oil. The rhamnolipid produced by this culture was the main factor that enhanced the distillation performance, which is related to the emulsification of hydrocarbon chains in the crude oil. This biotreatment may play an important role to improve the existing conventional refinery and distillation process. Reducing the distillation times by pretreating the crude oil with a natural biosynthetic product translates to energy and cost savings in producing petroleum products.
Oxidative damage and antioxidant status in patients with cervical intraepithelial neoplasia and carcinoma of the cervix

Looi ML, Mohd Dali AZ, Md Ali SA, Wan Ngah WZ, Mohd Yusof YA

Eur J Cancer Prev, 2008 Nov;17(6):555-60.
PMID: 18941377 DOI: 10.1097/CEJ.0b013e328305a10b

Free radicals that induced lipid peroxidation and DNA damage have been implicated in many diseases including cancer. Cellular antioxidant defense plays an important role in neoplastic disease to counteract oxidative damage. This study aims to investigate the status of oxidative damage by measuring plasma malondialdehyde (MDA) level and urinary 8-hydroxydeoxyguanosine (8-OHdG), and the level of antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase in patients with cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC) of the cervix. Urinary 8-OHdG was measured by an enzyme-linked immunosorbent assay kit. MDA and antioxidant enzyme activities were determined by high-performance liquid chromatography and spectrophotometry, respectively. Eighty patients with CIN and SCC of the cervix were recruited and compared with normal controls. Urinary 8-OHdG/creatinine ratio did not show any significant changes in any disease status studied as compared with controls (P=0.803). Plasma MDA was found to be increased in CIN and SCC patients when compared with controls (P=0.002). Glutathione peroxidase activity was increased (P=0.0001) whereas superoxide dismutase and catalase activity was decreased (P=0.019 and 0.0001, respectively) in both CIN and SCC patients when compared with controls. Urinary 8-OHdG may not be a good marker for enhanced oxidative stress in cervical cancer. Oxidative damage as demonstrated by the level of MDA is markedly increased in CIN and SCC patients with changes of enzymatic antioxidants observed.
Ab-Externo Implantation of XEN Gel Stent for Refractory Steroid-Induced Glaucoma After Lamellar Keratoplasty

Tan SY, Md Din N, Mohd Khialdin S, Wan Abdul Halim WH, Tang SF

Cureus, 2021 Feb 12;13(2):e13320.
PMID: 33738163 DOI: 10.7759/cureus.13320

The hazy corneal donor-recipient interface after corneal transplant may cause difficulties when implanting the XEN gel stent via ab-interno approach. We aim to describe XEN gel stent implantation via ab-externo approach in refractory steroid-induced glaucoma after corneal lamellar keratoplasty. Under local anaesthesia, the XEN injector needle was inserted 7 mm behind the limbus with the bevel facing up, directly beneath the conjunctiva and advanced to the marked 2.5 mm scleral entry wound. The needle then pierced the sclera until the needle tip was just visible in the anterior chamber (AC). The slider was pushed until the tip of the XEN stent was seen in the AC. The needle was slowly withdrawn while still pushing the slider to complete stent deployment. Subconjunctival Mitomycin C 0.01% (30 µg/0.3 mL) was then injected posterior to the bleb. Three eyes of three patients with steroid-induced glaucoma after lamellar keratoplasty underwent XEN gel stent implantation via ab-externo approach placed at the superotemporal quadrant. Pre-operatively, all patients had uncontrolled IOP between 30-45 mmHg despite maximum medications and selective laser trabeculoplasty. After XEN gel stent implantation, IOP ranged between 10-17 mmHg with one or two topical antiglaucoma at 12 months. Complications include hypotony maculopathy, stent migration and hyphaema, all of which were successfully managed. Corneal graft remained clear at 12 months. XEN gel stent implantation via ab-externo approach is able to achieve good intraocular pressure (IOP) control without compromising cornea graft in patients with steroid-induced glaucoma after lamellar keratoplasty at 12 months.
LAT is essential for the mast cell stabilising effect of tHGA in IgE-mediated mast cell activation

Tan JW, Israf DA, Md Hashim NF, Cheah YK, Harith HH, Shaari K, et al.

Biochem Pharmacol, 2017 Nov 15;144:132-148.
PMID: 28813645 DOI: 10.1016/j.bcp.2017.08.010

Mast cells play a central role in the pathogenesis of allergic reaction. Activation of mast cells by antigens is strictly dependent on the influx of extracellular calcium that involves a complex interaction between signalling molecules located within the cells. We have previously reported that tHGA, an active compound originally isolated from a local shrub known as Melicope ptelefolia, prevented IgE-mediated mast cell activation and passive systemic anaphylaxis by suppressing the release of interleukin-4 (IL-4) and tumour necrosis factor (TNF)-α from activated rat basophilic leukaemia (RBL)-2H3 cells. However, the mechanism of action (MOA) as well as the molecular target underlying the mast cell stabilising effect of tHGA has not been previously investigated. In this study, DNP-IgE-sensitised RBL-2H3 cells were pre-treated with tHGA before challenged with DNP-BSA. To dissect the MOA of tHGA in IgE-mediated mast cell activation, the effect of tHGA on the transcription of IL-4 and TNF-α mRNA was determined using Real Time-Polymerase Chain Reaction (qPCR) followed by Calcium Influx Assay to confirm the involvement of calcium in the activation of mast cells. The protein lysates were analysed by using Western Blot to determine the effect of tHGA on various important signalling molecules in the LAT-PLCγ-MAPK and PI3K-NFκB pathways. In order to identify the molecular target of tHGA in IgE-mediated mast cell activation, the LAT and LAT2 genes in RBL-2H3 cells were knocked-down by using RNA interference to establish a LAT/LAT2 competition model. The results showed that tHGA inhibited the transcription of IL-4 and TNF-α as a result of the suppression of calcium influx in activated RBL-2H3 cells. The results from Western Blot revealed that tHGA primarily inhibited the LAT-PLCγ-MAPK pathway with partial inhibition on the PI3K-p65 pathway without affecting Syk. The results from RNAi further demonstrated that tHGA failed to inhibit the release of mediators associated with mast cell degranulation under the LAT/LAT2 competition model in the absence of LAT. Collectively, this study concluded that the molecular target of tHGA could be LAT and may provide a basis for the development of a mast cell stabiliser which targets LAT.
Optimization strategy for laccase immobilization on polyethylene terephthalate grafted with maleic anhydride electrospun nanofiber mat

Mohd Syukri MS, A Rahman R, Mohamad Z, Md Illias R, Nik Mahmood NA, Jaafar NR

Int J Biol Macromol, 2021 Jan 01;166:876-883.
PMID: 33144251 DOI: 10.1016/j.ijbiomac.2020.10.244

Enzyme immobilization has been known to be one of the methods to improve the stability and reusability of enzyme. In this study, a strategy to optimize laccase immobilization on polyethylene terephthalate grafted with maleic anhydride electrospun nanofiber mat (PET-g-MAH ENM) was developed. The development involves the screening and optimization processes of the crucial factors that influence the immobilization yield such as enzyme concentration, pH values, covalent bonding (CV) time, CV temperature, crosslinking (CL) time, CL temperature and glutaraldehyde concentration using two-level factorial design and Box-Behnken design (BBD), respectively. It was found that laccase concentration, pH values and glutaraldehyde concentration play important role in enhancing the immobilization yield of laccase on PET-g-MAH ENM in the screening process. Subsequently, the optimization result showed at 0.28 mg/ml laccase concentration, pH 3 and 0.45% (v/v) glutaraldehyde concentrations gave the highest immobilization yield at 87.64% which was 81.2% increment from the immobilization yield before optimization. Under the optimum condition, the immobilized laccase was able to oxidize 2, 2-azino-bis 3-ethylbenzothiazoline-6- sulfonic acid (ABTS) in a broad range of pH (pH 3-6) and temperature (20- 70 °C). Meanwhile, the kinetic parameters for Km and Vmax were 1.331 mM and 0.041 mM/min, respectively. It was concluded that the optimization of immobilized laccase on PET-g-MAH ENM enhance the performance of this biocatalyst.
Development and Practical Application of a Multiple-Criteria Decision Analysis Framework on Respiratory Inhalers: Is It Always Useful in the MOH Malaysia Medicines Formulary Listing Context?

Yong YV, Mahamad Dom SH, Ahmad Sa'ad N, Lajis R, Md Yusof FA, Abdul Rahaman JA

MDM Policy Pract, 2021 03 30;6(1):2381468321994063.
PMID: 33855190 DOI: 10.1177/2381468321994063

Objectives. The current health technology assessment used to evaluate respiratory inhalers is associated with limitations that have necessitated the development of an explicit formulary decision-making framework to ensure balance between the accessibility, value, and affordability of medicines. This study aimed to develop a multiple-criteria decision analysis (MCDA) framework, apply the framework to potential and currently listed respiratory inhalers in the Ministry of Health Medicines Formulary (MOHMF), and analyze the impacts of applying the outputs, from the perspective of listing and delisting medicines in the formulary. Methods. The overall methodology of the framework development adhered to the recommendations of the ISPOR MCDA Emerging Good Practices Task Force. The MCDA framework was developed using Microsoft Excel 2010 and involved all relevant stakeholders. The framework was then applied to 27 medicines, based on data gathered from the highest levels of available published evidence, pharmaceutical companies, and professional opinions. The performance scores were analyzed using the additive model. The end values were then deliberated by an expert committee. Results. A total of eight main criteria and seven subcriteria were determined by the stakeholders. The economic criterion was weighted at 30%. Among the noneconomic criteria, "patient suitability" was weighted the highest. Based on the MCDA outputs, the expert committee recommended one potential medicine (out of three; 33%) be added to the MOHMF and one existing medicine (out of 24; 4%) be removed/delisted from the MOHMF. The other existing medicines remained unchanged. Conclusions. Although this framework was useful for deciding to add new medicines to the formulary, it appears to be less functional and impactful for the removal/delisting existing medicines from the MOHMF. The generalizability of this conclusion to other formulations remains to be confirmed.
Early Detection of High-frequency Presbycusis Among Normal Hearing Individuals

Aziz A, Md Daud MK, Nik Othman NA, Abd Rahman N

Otol Neurotol, 2020 09;41(8):e989-e992.
PMID: 32472918 DOI: 10.1097/MAO.0000000000002725

BACKGROUND: Presbycusis is an age-related sensorineural hearing loss and it may reduce quality of life. We conducted a study to establish the prevalence of high-frequency presbycusis in normal hearing individuals and to validate the role of extended high-frequency distortion product otoacoustic emission (DPOAE) in the screening.
METHOD: A cross-sectional study was conducted among 205 normal hearing adult participants with an age range between 25 and 54 years old. Hearing analysis with extended high-frequency pure-tone audiometry (PTA) and high-frequency DPOAE was carried out for all eligible participants. High-frequency presbycusis was considered to be present when the impairment of more than 25 dB occurs at higher than 8 kHz frequencies on both ears.
RESULTS: Prevalence of high-frequency presbycusis using extended PTA was 31.7 (95% CI: 25.3, 38.1) and using high-frequency DPOAE was 57.4 (95% CI: 50.7, 64.4). The sensitivity and specificity of high-frequency DPOAE in detecting high-frequency presbycusis were 72.3 and 49.3% respectively with positive predictive value of 39.8% and negative predictive value of 79.3%. The association between age and high-frequency presbycusis was significant based on high-frequency DPOAE (p = 0.029).
CONCLUSIONS: The prevalence of high-frequency hearing loss is higher with increasing in age. High-frequency DPOAE may be used as a screening tool followed by confirmation using extended PTA. The early detection of presbycusis is important so that measures can be taken to prevent more severe problems developing.
Fulltext Comparative Analysis on Dielectric Gold and Aluminium Triangular Junctions: Impact of Ionic Strength and Background Electrolyte by pH Variations

Letchumanan I, Md Arshad MK, Gopinath SCB, Rajapaksha RDAA, Balakrishnan SR

Sci Rep, 2020 Apr 22;10(1):6783.
PMID: 32321969 DOI: 10.1038/s41598-020-63831-w

Field of generating a surface thin film is emerging broadly in sensing applications to obtain the quick and fast results by forming the high-performance sensors. Incorporation of thin film technologies in sensor development for the better sensing could be a promising way to attain the current requirements. This work predominantly delineates the fabrication of the dielectric sensor using two different sensing materials (Gold and Aluminium). Conventional photolithography was carried out using silicon as a base material and the photo mask of the dielectric sensor was designed by AutoCAD software. The physical characterization of the fabricated sensor was done by Scanning Electron Microscope, Atomic Force Microscope, High Power Microscope and 3D-nano profiler. The electrical characterization was performed using Keithley 6487 picoammeter with a linear sweep voltage of 0 to 2 V at 0.01 V step voltage. By pH scouting, I-V measurements on the bare sensor were carried out, whereby the gold electrodes conducts a least current than aluminium dielectrodes. Comparative analysis with pH scouting reveals that gold electrode is suitable under varied ionic strengths and background electrolytes, whereas aluminium electrodes were affected by the extreme acid (pH 1) and alkali (pH 12) solutions.
Diversity and Coding Potential of the Microbiota in the Photic and Aphotic Zones of Tropical Man-Made Lake with Intensive Aquaculture Activities: a Case Study on Temengor Lake, Malaysia

Lau NS, Zarkasi KZ, Md Sah ASR, Shu-Chien AC

Microb Ecol, 2019 Jul;78(1):20-32.
PMID: 30397794 DOI: 10.1007/s00248-018-1283-0

Although freshwater biomes cover less than 1% of the Earth's surface, they have disproportionate ecological significances. Attempts to study the taxonomy and function of freshwater microbiota are currently limited to samples collected from temperate lakes. In this study, we investigated samples from the photic and aphotic of an aquaculture site (disturbed) of Temengor Lake, a tropical lake in comparison with the undisturbed site of the lake using 16S rRNA amplicon and shotgun metagenomic approaches. Vertical changes in bacterial community composition and function of the Temengor Lake metagenomes were observed. The photic water layer of Temengor Lake was dominated by typical freshwater assemblages consisting of Proteobacteria, Actinobacteria, Bacteroidetes, Verrucomicrobia, and Cyanobacteria lineages. On the other hand, the aphotic water featured in addition to Proteobacteria, Bacteroidetes, Verrucomicrobia, and two more abundant bacterial phyla that are typically ubiquitous in anoxic habitats (Chloroflexi and Firmicutes). The aphotic zone of Temengor Lake exhibited genetic potential for nitrogen and sulfur metabolisms for which terminal electron acceptors other than oxygen are used in the reactions. The aphotic water of the disturbed site also showed an overrepresentation of genes associated with the metabolism of carbohydrates, likely driven by the enrichment of nutrient resulting from aquaculture activities at the site. The results presented in this study can serve as a basis for understanding the structure and functional capacity of the microbial communities in the photic and aphotic zones/water layers of tropical man-made lakes.
Effects of degree of substitution and irradiation doses on the properties of hydrogel prepared from carboxymethyl-sago starch and polyethylene glycol

Zahib IR, Md Tahir P, Talib M, Mohamad R, Alias AH, Lee SH

Carbohydr Polym, 2021 Jan 15;252:117224.
PMID: 33183648 DOI: 10.1016/j.carbpol.2020.117224

Carboxymethyl starch (CMS) was produced from sago starch via carboxymethylation. The CMS with different degree of substitution (DS) ranges from 0.4 to 0.8 were mixed with polyethylene glycol (PEG) of different molecular weight and distilled water and the hydrogel was cured by electron beam irradiation with doses ranging from 25 to 35 kGy. The results revealed that CMS-PEG hydrogels with DS 0.4 give the optimum gel content when radiated at 30 kGy and with PEG 600. Thermogravimetric analysis (TGA) revealed that there are two phases exist in CMS with DS 0.4 in contrast to the three steps decomposition occurs in DS 0.6 and 0.8. It shows that the CMS with DS 0.4 is more thermally stable. Surface morphology revealed crosslinking among the blends when subjected into the radiation dose. The study shows both radiation and PEG addition improved most of the properties of CMS irrespective of the DS value.
Fulltext Optimization of an Ultrasound-Assisted Extraction Condition for Flavonoid Compounds from Cocoa Shells (Theobroma cacao) Using Response Surface Methodology

Md Yusof AH, Abd Gani SS, Zaidan UH, Halmi MIE, Zainudin BH

Molecules, 2019 Feb 16;24(4).
PMID: 30781448 DOI: 10.3390/molecules24040711

This study investigates the ultrasound-assisted extraction of flavonoids from Malaysian cocoa shell extracts, and optimization using response surface methodology. There are three variables involved in this study, namely: ethanol concentration (70⁻90 v/v %), temperature (45⁻65 °C), and ultrasound irradiation time (30⁻60 min). All of the data were collected and analyzed for variance (ANOVA). The coefficient of determination (R²) and the model was significant in interaction between all variables (98% and p < 0.0001, respectively). In addition, the lack of fit test for the model was not of significance, with p > 0.0684. The ethanol concentration, temperature, and ultrasound irradiation time that yielded the maximum value of the total flavonoid content (TFC; 7.47 mg RE/g dried weight (DW)) was 80%, 55 °C, and 45 min, respectively. The optimum value from the validation of the experimental TFC was 7.23 ± 0.15 mg of rutin, equivalent per gram of extract with ethanol concentration, temperature, and ultrasound irradiation time values of 74.20%, 49.99 °C, and 42.82 min, respectively. While the modelled equation fits the data, the T-test is not significant, suggesting that the experimental values agree with those predicted by the response surface methodology models.
Mutagenicity and genotoxicity effects of Verbena officinalis leaves extract in Sprague-Dawley Rats

Fateh AH, Mohamed Z, Chik Z, Alsalahi A, Md Zain SR, Alshawsh MA

J Ethnopharmacol, 2019 May 10;235:88-99.
PMID: 30738113 DOI: 10.1016/j.jep.2019.02.007

ETHNOPHARMACOLOGICAL RELEVANCE: Traditionally, Verbena officinalis L. has been used for reproductive and gynaecological purposes. However, the mutagenicity and genotoxicity of V. officinalis have not been extensively investigated.
AIM OF THE STUDY: To assess the in vitro mutagenicity and in vivo genotoxicity of aqueous extract of V. officinalis leaves using a modified Ames test and rat bone marrow micronucleus assay according to OECD guidelines.
MATERIALS AND METHODS: In vitro Ames test was carried out using different strains of Salmonella (TA97a, TA98, TA100, and TA1535) and Escherichia coli WP2 uvrA (pKM101) in the presence or absence of metabolic activation (S9 mixture). For micronucleus experiment, male and female Sprague-Dawley rats (n = 6/group) were received a single oral daily dose of 500, 1000, and 2000 mg/kg of V. officinalis extract for three days. Negative and positive control rats were received distilled water or a single intraperitoneal injection of 50 mg/kg of cyclophosphamide, respectively. Following dissection, femurs were collected and bone marrow cells were stained with May-Grünwald-Giemsa solution for micronucleus assessment.
RESULTS: Ames test results demonstrated that 5, 2.5, 1.25 and 0.625 mg/ml of V. officinalis extract induced a significant mutagenic effect against TA100 and TA98 strains (with and without metabolic activation). Findings of the animal study showed there were no significant increase in the micronucleated polychromatic erythrocytes (MNPE) and no significant alterations in the polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE) ratio of treated rats as compared with their negative control. Meanwhile, significantly increased in the MNPEs was seen in the cyclophosphamide-treated group only.
CONCLUSION: Aqueous extract of V. officinalis has mutagenic effect against TA98 and TA100 strains as demonstrated by Ames test, however, there is no in vivo clastogenic and myelotoxic effect on bone marrow micronucleus of rats indicating that the benefits of using V. officinalis in traditional practice should outweigh risks.

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